Complexation and electrode effects on the electrochemical behavior of the cerium(Iv)/cerium(Iii) redox couple

The electrochemistry of the Ce(IV)/Ce(III) redox couple was investigated as a function of working electrode composition and solution environment. Optimum redox couple resolution in aqueous sulfuric acid was achieved at an acid concentration of 0.1 M. A decline in redox couple resolution and reversibility was observed as acid concentration was increased to 2.0 M. The influence of pH was illustrated using sulfate solutions of increasing pH and constant ionic strength. Results indicated that a pH greater than 2 was detrimental to redox couple resolution. The glassy carbon electrode provided the widest potential window and was least affected by changes in pH. Studies were conducted in aqueous NTA, citrate, and EDTA, but redox couple resolution was successful only at the Pt electrode in EDTA. Complexation with EDTA resolved cerium electrochemistry from background currents by shifting the redox couple to less positive potentials, and allowed its observation across a wide pH range

Kefir induces cell-cycle arrest and apoptosis in HTLV-1-negative malignant T-lymphocytes

Katia Maalouf1, Elias Baydoun2, Sandra Rizk11Department of Natural Sciences, Lebanese American University, Beirut, Lebanon; 2Department of Biology, American University of Beirut, Beirut, LebanonBackground: Adult lymphoblastic leukemia (ALL) is a malignancy that occurs in white blood cells. The overall cure rate in children is 85%, whereas it is only 40% in adults. Kefir is an important probiotic that contains many bioactive ingredients, which give it unique health benefits. It has been shown to control several cellular types of cancer.Purpose: The present study investigates the effect of a cell-free fraction of kefir on CEM and Jurkat cells, which are human T-lymphotropic virus type I (HTLV-1)-negative malignant T-lymphocytes.Methods: Cells were incubated with different kefir concentrations. The cytotoxicity of the compound was evaluated by determining the percentage viability of cells. The effect of all the noncytotoxic concentrations of kefir on the proliferation of CEM and Jurkat cells was then assessed. The levels of transforming growth factor-alpha (TGF-α), transforming growth factor- beta1 (TGF-β1), matrix metalloproteinase-2 (MMP-2), and MMP-9 mRNA upon kefir treatment were then analyzed using reverse transcriptase polymerase chain reaction (RT-PCR). Finally, the growth inhibitory effects of kefir on cell-cycle progression/apoptosis were assessed by Cell Death Detection (ELISA) and flow cytometry.Results: The maximum cytotoxicity recorded after 48-hours treatment with 80 µg/µL kefir was only 42% and 39% in CEM and Jurkat cells, respectively. The percent reduction in proliferation was very significant, and was dose-, and time-dependent. In both cell lines, kefir exhibited its antiproliferative effect by downregulating TGF-α and upregulating TGF- β1 mRNA expression. Upon kefir treatment, a marked increase in cell-cycle distribution was noted in the preG1 phase of CEM and Jurkat cells, indicating the proapoptotic effect of kefir, which was further confirmed by Cell Death Detection ELISA. However, kefir did not affect the mRNA expression of metalloproteinases needed for the invasion of leukemic cell lines.Conclusion: In conclusion, kefir is effective in inhibiting proliferation and inducing apoptosis of HTLV-1-negative malignant T-lymphocytes. Therefore, further in vivo investigation is highly recommended.Keywords: apoptosis, cancer, CEM, Jurkat, kefir, leukemi

The Effectiveness of Learning Instruments of Speaking Containing Character Values toward Speaking Learning

This development research aimed at describing the effectiveness of learning instruments of speaking that were contained in character values. The objects of the study were a syllabus, lesson plan, textbook, and assessment. The subjects of the study were the lecturers of Speaking and the 2nd-semester students of IIA, IIB, and IIC in the academic year of 2015/2016. The data was collected through observation, questionnaire, and test. The data was analyzed by administering descriptive qualitative technique and descriptive statistics. The results of the study showed that the learning instruments was effective to be used in the teaching and learning process, to improve students understanding on the materials, to improve students speaking skill, and to shape characters such as religious, polite, communicative, open, democratic, respectful, responsible, curious, discipline, confident, cooperative, appreciate achievement, logic, critic, creative and innovative, and love reading. The results of the study indicated that the learning instruments of speaking contained of character values were effective so that it was feasible to be used by both lecturers and students of Indonesian Language and Literature Department, Language and Art Faculty of Ganesha University of Education

La diversidad en el ámbito rural

En el trabajo Fin de Grado que se presenta a continuación se ha realizado un estudio en torno a la educación inclusiva en el ámbito rural, prestando atención a la respuesta que se da desde los centros situados en dicho ámbito a los alumnos con necesidades educativas especiales. El trabajo parte de la idea preconcebida que se tiene sobre la educación rural, sobre la cual pensamos que debido a la falta de medios los niños pueden sufrir carencias en su educación escolar, llegando a modificar dicha idea preconcebida gracias al estudio teórico y práctico de la educación rural y de la atención a la diversidad.<br /

Efecto de los efluentes cloacales sobre el ensamble macrobentónico submareal en un estuario urbano de la Argentina

Se analizó el efecto de los efluentes cloacales sin tratamiento sobre el ensamble macrobentónico submareal del estuario de Bahía Blanca. Se examinaron las variaciones espaciales en los descriptores biológicos en relación con los parámetros ambientales y la distribución de metales en los sedimentos de un canal afectado por efluentes urbanos. A lo largo del canal se registraron valores de concentración de metales mayores a los de la zona interna del estuario (sitio de referencia). Los valores más altos de turbidez del agua se registraron en el sitio próximo a la zona de descarga del efluente y en la zona media del canal, donde, además, se depositaron sedimentos de un dragado de la zona portuaria e industrial realizado dos años antes que este estudio. La densidad del ensamble disminuyó hacia la zona cercana a la descarga del efluente, mientras que la riqueza y la diversidad alcanzaron valores mínimos tanto en la zona de descarga como la zona media. Sólo dos especies de poliquetos se asociaron con estas áreas: Laeonereis acuta y Aphelochaeta sp.; el primero se encontró en la zona de descarga de efluentes, donde Cd y Pb fueron los metales más abundantes, y el segundo fue la especie dominante en el sitio caracterizado por la presencia de material de dragado y altas concentraciones de Cr y Ni. Este estudio proporciona datos de base con los cuales contrastar futuras medidas de manejo.We examined spatial variations in the biological descriptors of macrobenthic assemblage in relation to environmental parameters and metal distribution in the sediments along a channel of Bahía Blanca estuary affected by non-treatment sewage effluents. Along the channel, metal concentration values were higher than those in the internal estuary area, a sector considered as a reference site. The highest values of water turbidity and metal content in sediments were observed in the effluent discharge zone and at the site where sediments from dredging activities were deposited two years ago. The density of macrobenthic assemblages decreased towards the effluent discharge zone, but the richness and diversity reached to minimum values in both disturbed areas. Only two species of polychaetes were associated with these areas: Laeonereis acuta and Aphelochaeta sp.; the former being found in the effluent discharge zone, where Cd and Pb were most abundant, and the latter being the dominant species in the site characterized by dredging material and high concentrations of Cr and Ni. This study is the first approach to explore the impact of anthropogenic activities over the macrobenthic assemblage of the Bahía Blanca estuary, providing background data to use future management decisions.Fil: Fiori, Sandra Marcela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto Argentino de Oceanografía. Universidad Nacional del Sur. Instituto Argentino de Oceanografía; Argentina. Universidad Nacional del Sur. Departamento de Biología, Bioquímica y Farmacia; ArgentinaFil: Bravo, María Emilia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto Argentino de Oceanografía. Universidad Nacional del Sur. Instituto Argentino de Oceanografía; ArgentinaFil: Elias, Rodolfo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; ArgentinaFil: Serra, Analia Veronica. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto Argentino de Oceanografía. Universidad Nacional del Sur. Instituto Argentino de Oceanografía; ArgentinaFil: Carcedo, Maria Cecilia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto Argentino de Oceanografía. Universidad Nacional del Sur. Instituto Argentino de Oceanografía; Argentina. Universidad Nacional del Sur. Departamento de Biología, Bioquímica y Farmacia; ArgentinaFil: Dos Santos, Eder Paulo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto Argentino de Oceanografía. Universidad Nacional del Sur. Instituto Argentino de Oceanografía; ArgentinaFil: Botté, Sandra Elizabeth. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto Argentino de Oceanografía. Universidad Nacional del Sur. Instituto Argentino de Oceanografía; Argentina. Universidad Nacional del Sur. Departamento de Biología, Bioquímica y Farmacia; Argentin

Dois casos de cerceamento à circulação de livros no Brasil no ano de 2021:: o expurgo da Fundação Palmares e a falsificação de postagens do Padre Lancelotti

This study discusses the issue of book censorship focusing specifically on two cases of hindering the circulation of books that occurred in Brazil in 2021, the third year of Jair Bolsonaro's far-right federal government. These cases used different strategies: in the first one, the Palmares foundation, there was censorship of books for preventing their circulation by pusing copies of a public library; and in the second, the case of the posting of Father Júlio Lancellotti, there was electronic manipulation of information in which the indication of a book was eliminated and replaced by another indication with an antagonistic sense to the initial proposition. In both cases – one of physical restraint and the other of digital adulteration – the authoritarian intention is explicit: the objective of the actions is and to eliminate the books and ideas defended in them from the public space, so that the ideas that the undemocratic authoritarians propagate are the only ones disseminated.Este estudo discute a questão da censura a livros enfocando especificamente dois casos de tentativa de cerceamento à circulação de livros ocorridos no Brasil no ano de 2021, terceiro ano do governo federal de extrema direita de Jair Bolsonaro. Estes casos utilizaram diferentes estratégias: no primeiro deles, o da fundação Palmares, houve a censura a livros pelo impedimento de circulação dos mesmos através da realização do expurgo dos exemplares de uma biblioteca pública; e no segundo, o caso da postagem do padre Júlio Lancellotti, houve manipulação eletrônica de uma informação em que a indicação de um livro foi eliminada e substituída por outra indicação portadora de um sentido antagônico à proposição inicial. Em ambos os casos – um de cerceamento físico e outro de adulteração digital - a intenção autoritária é explícita: o objetivo das ações é e eliminar os livros e as ideias neles defendidas do espaço público, para que as ideias que os autoritários antidemocráticos propagam sejam as únicas difundidas