70 research outputs found
A pedagogia de Paulo Freire no Centro Municipal de Educação de Jovens e Adultos - CEJA Erechim
O presente trabalho tem como objetivo analisar a influência teórica de Paulo Freire em
relação ao Centro Municipal de Educação de Jovens e Adultos (CEJA), da cidade de Erechim/
RS, no que se refere à perspectiva metodológica desenvolvida na instituição. Verificar em que
medida seu pensamento está influenciando e sendo reinventado no Centro e conhecer os
critérios utilizados na concessão da Medalha Paulo Freire, recebida pela instituição no ano de
2010. Para isso, realiza-se uma análise documental qualitativa do regimento escolar, do
Projeto Político Pedagógico e dos Decretos e Leis que instituíram o Centro comparando-se as
ideias de Paulo Freire e a metodologia utilizada na instituição. A fim de alcançar esses
objetivos utiliza-se de algumas bibliografias de Paulo Freire e outros estudiosos do campo da
educação popular. A partir do estudo realizado percebe-se que é necessário trabalhar com os
estudantes a partir da realidade em que estão inseridos, bem como a faixa etária. Entretanto, é
importante reinventar a metodologia utilizada, permitindo que os mesmos desenvolvam a
autonomia e criticidade. Também é possível afirmar que está previsto no CEJA Erechim o
trabalho a partir da mesma linha teórica que Freire, pois em várias passagens do Regimento e
do PPP há indícios e referências às suas ideias
Recommended from our members
Parthenogenetic activation of bovine oocytes using bovine and murine phospholipase C zeta
Background - During natural fertilization, sperm fusion with the oocyte induces long lasting intracellular calcium oscillations which in turn are responsible for oocyte activation. PLCZ1 has been identified as the factor that the sperm delivers into the egg to induce such a response. We tested the hypothesis that PLCZ1 cRNA injection can be used to activate bovine oocytes. Results - Mouse and bovine PLCZ1 cRNAs were injected into matured bovine oocytes at different concentrations. Within the concentrations tested, mouse PLCZ1 injection activated bovine oocytes at a maximum rate when the pipette concentration of cRNA ranged from 0.25 to 1 μg/μL, while bovine PLCZ1 was optimal at 0.1 μg/μL. At their most effective concentrations, PLCZ1 induced parthenogenetic development at rates similar to those observed using other activation stimuli such as Ionomycin/CHX and Ionomycin/DMAP. Injection of mouse and bovine PLCZ1 cRNA induced dose-dependent sperm-like calcium oscillations whose frequency increased over time. Injection of bovine and mouse PLCZ1 cRNA also induced IP3R-1 degradation, although bovine PLCZ1 cRNA evoked greater receptor degradation than its mouse counterpart. Conclusion - Injection of PLCZ1 cRNA efficiently activated bovine oocytes by inducing a sperm-like calcium oscillatory pattern. Importantly, the high rate of aneuploidy encountered in parthenogenetic embryos activated by certain chemical means was not observed in PLCZ1 activated embryos
Parthenogenetic activation of bovine oocytes using bovine and murine phospholipase C zeta
Disciplina radnje, evokacija s fusnotama uloga vlaka, u školovanju
Tion. b) Pipette advanced into the oocyte; cytoplasm is aspirated to break the plasma membrane. c) Aspirated cytoplasm and Texas Red dextran are injected into the oocyte. d) Schematic representation of the microscope reticulum used as guide to control the injected volume. The oocyte is represented in yellow and the pipette in blue. The red lines indicate the volume introduced into the oocyte which, calculated measuring the pipette internal diameters at both ends, is 5.9 pL. e) An oil drop of the same size as the injected volume is shown next to an oocyte. f) Oocytes injected using Texas Red dextran. g) From left to right, oocyte injected 2X and 1X the normal volume of Texas Red dextran. h) Fluorescent intensity profile of the line shown in f. i) Fluorescent intensity profile of the line shown in g. j) Developmental rates of injected and uninjected bovine oocytes after activation using ionomycin/DMAP.<p><b>Copyright information:</b></p><p>Taken from "Parthenogenetic activation of bovine oocytes using bovine and murine phospholipase C zeta"</p><p>http://www.biomedcentral.com/1471-213X/8/16</p><p>BMC Developmental Biology 2008;8():16-16.</p><p>Published online 19 Feb 2008</p><p>PMCID:PMC2266721.</p><p></p
Improved in vitro development of cloned bovine embryos using S-adenosylhomocysteine, a non-toxic epigenetic modifying reagent.
In this study, fibroblast cells were stably transfected with mouse POU5F1 promoter-driven enhanced green fluorescent protein (EGFP) to investigate the effect of S-adenosylhomocysteine (SAH), the reversible non-toxic inhibitor of DNA-methyltransferases (DNMTs), at different intervals post-fusion on in vitro development of cloned bovine embryos. Treatment with SAH for 12 hr resulted in 54.6 ± 7.7% blastocyst production, which was significantly greater than in vitro fertilized embryos (IVF: 37.2 ± 2.7%), cloned embryos treated with SAH for 72 hr (31.0 ± 7.6%), and control cloned embryos (34.6 ± 3.6%). The fluorescence intensities of the EGFP-POU5F1 reporter gene at all intervals of SAH treatment, except of 72 hr, were significantly higher than control somatic cell nuclear transfers (SCNT) embryos. The intensity of DNA-methylation in cloned embryos treated with SAH for 48 hr was similar to that of IVF embryos, and was significantly lower than the other SCNT groups. The levels of H3K9 acetylation in all SCNT groups were significantly lower than IVF embryos. Real-time PCR analysis of gene expression revealed significantly higher expression of POU5F1 in cloned versus IVF blastocysts. Neither embryo production method (SCNT vs. IVF) nor the SAH treatment interval affected expression of the BCL2 gene. Cloned embryos at all intervals of SAH treatment, except for 24 hr, had significantly increased VEGF transcript compared to IVF and control SCNT embryos. It was suggested that the time interval of DNMT inhibition may have important consequences on different in vitro features of bovine SCNT, and the improving effects of DNMT inhibition on developmental competency of cloned embryos are restricted to a specific period of time preceding de novo methylation. Mol. Reprod. Dev. 78:576–584, 2011
The Structural Diversity of Carbohydrate Antigens of Selected Gram-Negative Marine Bacteria
Marine microorganisms have evolved for millions of years to survive in the environments characterized by one or more extreme physical or chemical parameters, e.g., high pressure, low temperature or high salinity. Marine bacteria have the ability to produce a range of biologically active molecules, such as antibiotics, toxins and antitoxins, antitumor and antimicrobial agents, and as a result, they have been a topic of research interest for many years. Among these biologically active molecules, the carbohydrate antigens, lipopolysaccharides (LPSs, O-antigens) found in cell walls of Gram-negative marine bacteria, show great potential as candidates in the development of drugs to prevent septic shock due to their low virulence. The structural diversity of LPSs is thought to be a reflection of the ability for these bacteria to adapt to an array of habitats, protecting the cell from being compromised by exposure to harsh environmental stress factors. Over the last few years, the variety of structures of core oligosaccharides and O-specific polysaccharides from LPSs of marine microrganisms has been discovered. In this review, we discuss the most recently encountered structures that have been identified from bacteria belonging to the genera Aeromonas, Alteromonas, Idiomarina, Microbulbifer, Pseudoalteromonas, Plesiomonas and Shewanella of the Gammaproteobacteria phylum; Sulfitobacter and Loktanella of the Alphaproteobactera phylum and to the genera Arenibacter, Cellulophaga, Chryseobacterium, Flavobacterium, Flexibacter of the Cytophaga-Flavobacterium-Bacteroides phylum. Particular attention is paid to the particular chemical features of the LPSs, such as the monosaccharide type, non-sugar substituents and phosphate groups, together with some of the typifying traits of LPSs obtained from marine bacteria. A possible correlation is then made between such features and the environmental adaptations undertaken by marine bacteria
Epigenetic modification with trichostatin A does not correct specific errors of somatic cell nuclear transfer at the transcriptomic level; highlighting the non-random nature of oocyte-mediated reprogramming errors
Genes differentially expressed by cumulus cells and assays using same to identify pregnancy competent oocytes
A genetic means of identifying pregnancy competent oocytes is provided. The means comprises detecting the level of expression of one or more genes that are expressed at characteristic levels (upregulated or downregulated) in cumulus cells derived from pregnancy competent oocytes. This characteristic gene expression level, or pattern referred to herein as the pregnancy signature , also can be used to identify subjects with underlying conditions that impair or prevent the development of a viable pregnancy, e.g., pre-menopausal condition, other hormonal dysfunction, ovarian dysfunction, ovarian cyst, cancer or other cell proliferation disorder, autoimmune disease and the like. In preferred embodiments the pregnancy signature will comprise one or more of ABCA6, NCAM1, OLFML3, PTPRA, SDF4, GPR137B, DDIT4, DUSP1, GPR137B, IDUA, KCTD5, NDNL2, SLC26A3, and TERF2IP
Interspecies Nuclear Transfer: Implications for Embryonic Stem Cell Biology
Accessibility of human oocytes for research poses a serious ethical challenge to society. This fact categorically holds true when pursuing some of the most promising areas of research, such as somatic cell nuclear transfer and embryonic stem cell studies. One approach to overcoming this limitation is to use an oocyte from one species and a somatic cell from another. Recently, several attempts to capture the promises of this approach have met with varying success, ranging from establishing human embryonic stem cells to obtaining live offspring in animals. This review focuses on the challenges and opportunities presented by the formidable task of overcoming biological differences among species
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