Cracking the social order and building from a decolonial praxis

Entrevista realizada por Héctor MonarcaEsta nueva sección de la revista pretende ser un espacio para la crítica al “capitalismo-colonialismo-patriarcado” en el marco de las relaciones entre educación y orden social. Aquí se enmarca la entrevista a Catherine Walsh cuyo objetivo es reflexionar sobre este orden social y la educación-pedagogía desde una perspectiva decolonial. Espera ser un aporte para el agrietamiento al orden dominante y para la construcción de una praxis social-comunitaria diferente, pensado desde y con Abya Yala. Catherine Walsh es una intelectual-militante pedagógicamente comprometida e involucrada durante muchos años en los procesos y luchas de justicia y transformación social y decolonial, en primer lugar en los Estados Unidos y, desde 1995, en el Ecuador y Abya Yala/América Latina. Es profesora y directora del Doctorado en Estudios Culturales Latinoamericanos de la Universidad Andina Simón Bolívar-EcuadorThis new section of the journal aims to be a space for the criticism of "capitalism-colonialism-patriarchy" in the framework of the relations between education and the social order. This is the framework of the interview with Catherine Walsh whose objective is to reflect on this social order and education-pedagogy from a decolonial perspective. It hopes to be a contribution toward the cracking of the dominant order and the construction of a different social-communitarian praxis, thought with and from Abya Yala. Catherine Walsh is an intellectual-militant, pedagogically committed and involved for many years in the processes and struggles for justice and social and decolonial transformation, first in the United States and, since 1995, in Ecuador and Abya Yala/Latin America. She is professor and Director of the Doctorate in Latin American Cultural Studies at the Universidad Andina Simón Bolívar-Ecuador

Genotoxicity of DrinkingWater Disinfectants in Plant Bioassays

The genotoxicity of two widely used drinking water disinfectants, sodium hypochlorite (NaClO) and chlorine dioxide (ClO2), and a new disinfectant, peracetic acid (PAA, CH3-CO-COOH), was evaluated in three short-term plant tests: (1) induction of anaphase chromosome aberrations in the root cells of Allium cepa, (2) micronucleus induction in the root cells of Vicia faba, and (3) micronucleus induction in Tradescantia pollen cells. The study was carried out in the laboratory by directly exposing the plants to several concentrations of the disinfectants in redistilled water at unadjusted (acid) and adjusted (neutral) pHs. Both 0.1 and 0.2 mg/l NaClO induced chromosome aberrations in the Allium cepa test at acid pH, but concentrations up to 0.5 mg/l of all the disinfectants were negative at neutral pH. Concentrations ranging from 0.1 to 0.5 mg/l NaClO, ClO2, and PAA induced micronuclei in Vicia faba at acid pH, while 1–2 mg/l NaClO and ClO2 and 0.5–2 mg/l PAA gave positive responses at neutral pH. Most of concentrations of ClO2 produced positive responses in the Tradescantia micronucleus test. In general, the highest levels of genotoxicity were observed under acid conditions; at acid pH, significant effects were induced by low concentrations of ClO2 and PAA. Since the test concentrations of disinfectants are typical of those encountered in the biocidal treatment of tap water and similar concentrations are consumed daily by a large number of people, the genotoxicity of these compounds may constitute a significant public health concern

Influence of Temperature on Mutagenicity in Plants Exposed to Surface Disinfected Drinking Water.

Disinfection of surface drinking water, particularly water chlorination, produces by-products with potential genotoxic and/or carcinogenic activity. A study carried out at a pilot plant for drinking water disinfection of lake water revealed mutagenic activity of three different disinfectants (sodium hypochlorite, chlorine dioxide and peracetic acid) in different seasons using in situ mutagenicity assays, both in animal (micronucleus test) and in plant organisms (anaphase chro- mosomal aberration and micronucleus tests). The effects of the disinfectants appeared to be modulated by the season of exposure. In this study, we tried to understand if (and to what extent) the temperature parameter could actually play an independent role in the registered seasonal variation of mutagenic effects, neglecting the variation of other parameters, e.g. physical conditions and chemical composition of the lake water. Therefore plants (Allium cepa for chromosomal aberration test and Vicia faba for micronucleus test) were exposed to the same disinfected lake-water samples at differ- ent temperatures (10°C, 20°C and 30°C), according the ones registered during the in situ experiment. Long-term expo- sure at the temperatures of 20°C (both Vicia faba and Allium cepa) and 30°C (Vicia faba only) to disinfected waters in- duced clear mutagenic effects. These results show that temperature is an important variable which should be taken into account when in situ exposure of plants is planned for mutagenicity testing. Also, different plant systems clearly show specific temperature ranges suitable for their growth, thereby indicating the need for an accurate selection of the test organism for a specific experimental plan

Emanation Study of Gas Radon on the Ancient Cuexcomate Geyser in Puebla City, Mexico

Radon measurements were collected over a period of nine months in the area of the ancient Cuexcomate geyser, in Puebla City. For measuring radon, the passive method of nuclear tracks in solids was used, using polycarbonate CR-39 as radiation sensitive material. Radon concentrations varied in strong anti-correlation with the rainfall intensity. And are lower compared to other locations, in concordance with the stratigraphic composition, as travertine and deposits of volcanic origin, corresponding to the geyser chemical composition and the active environment in the north part of the Trans-Mexican Volcanic Belt with an andesitic and basalt composition

Italian multicenter study on infection hazards during dental practice: control of environmental microbial contamination in public dental surgeries.

BACKGROUND: The present study assessed microbial contamination in Italian dental surgeries. METHODS: An evaluation of water, air and surface microbial contamination in 102 dental units was carried out in eight Italian cities. RESULTS: The findings showed water microbial contamination in all the dental surgeries; the proportion of water samples with microbial levels above those recommended decreased during working. With regard to Legionella spp., the proportion of positive samples was 33.3%. During work activity, the index of microbial air contamination (IMA) increased. The level of microbial accumulation on examined surfaces did not change over time. CONCLUSION: These findings confirm that some Italian dental surgeries show high biocontamination, as in other European Countries, which highlights the risk of occupational exposure and the need to apply effective measures to reduce microbial loads