Sistema Regional de Información
en línea para Revistas Científicas de América Latina,
el Caribe, España y Portugal

Context: Water is essential for life and conservation of water quality is vital. The amount of fresh water on earth is limited and its quality is subject to constant pressure. This problem makes it necessary to present tools that allow quantifying the possible impacts generated by human activities in this resource. Therefore, this research determines the water footprint in the coastal area of San Blas, Mexico. Method: This work estimates the water footprint in the coastal area of he municipality of San Blas, Nayarit, Mexico, according to the method of water scarcity that occurs when demand exceeds the supply of fresh water in a given area. This method considers the water stress index in its calculation. Results: The result shows that the water footprint to quantify the total volume of water used by the inhabitants is less than the national average. In this way, the study area does not present water stress, since the extraction of water has not exceeded its availability. Conclusions: The water footprint by the scarcity method can be considered as an indicator of the proportion of annual withdrawals and water availability; It allows comparisons of the pressure to which the water resource is subjected between zones, regions and countries. In addition, it can contribute to the planning of the distribution and management of water in agricultural and urban use, in regions such as this study, where the area of agricultural use exceeds 35%. The estimation of the water footprint presented in this work considers the relationship between the extraction of fresh water for human use and its total water availability in a given region (WSI), the volume distributed and the percentage of drinking water coverage of the area in study.

The National Exam of Upper Secondary Education is a large-scale evaluation whose results are currently used as selection criteria for most part of Brazilian higher education institutions. Considering how specific these federal institutions of professional and technological education are, and also the fact they offer public and free high school education, the objective of this study is to analyze the performance of these federal institutions of professional and technological education on National Exam of Upper Secondary Education. This is a descriptive-exploratory and quantitative research. To do it so, the latest microdata were used, provided by the Ministry of Education in 2015. The examinations’ results were extracted, originally from the federal institutions, state, municipal and private schools. The analysis was carried out in the four knowledge areas (Languages and Codes, Natural Sciences, Humanities and Mathematics) and an essay. The results have shown that the average performance of the federal institutions stands out in front of the municipal, state and private ones, even considering only the 30 best students of each institution, except for the writing section, when compared to the private ones. We conclude that the federal network of professional and technological education, when compared to the other types of institutions, has been presenting a better performance on National Exam of Upper Secondary Education in all areas of knowledge.

La presente investigación tiene como objetivo determinar el impacto de la tasa de eficiencia de los proyectos de inversión pública ejecutados en el sector educación del nivel primaria por el Gobierno Regional La Libertad en la ciudad de Trujillo en los años 2005 – 2011 en la tasa del nivel de logro satisfactorio en comprensión lectora de los alumnos de educación primaria en la ciudad de Trujillo de conformidad con los lineamientos establecidos en los documentos de pre inversión y evaluación ex post aprobados por las instancias correspondientes e información proveniente de la Gerencia Regional de Infraestructura del Gobierno Regional La Libertad y la evaluación censal de estudiantes ECE elaborada por el Ministerio de Educación a través de la unidad de medición educativa UME. Los resultados muestran una relación directa positiva entre las dos variables, por lo cual se concluye que existe suficiente evidencia empírica para concluir que la variable independiente, ha incidido en el aumento de la tasa del nivel logro satisfactorio en comprensión lectora de los alumnos de educación primaria en la ciudad de Trujillo. De esta manera se recomienda priorizar la ejecución en proyectos en el sector educación debido al impacto significativo en los indicadores del sector educación.

La presente investigación se realizó con el objetivo de determinar el tipo de personalidad predominante en los estudiantes del 1° y 4° años de la facultad de Educación y ciencias de la comunicación de la Universidad Nacional de Trujillo, así como establecer correlaciones entre éste con la carrera y mención elegida por los estudiantes. Para la ejecución del presente estudio, hemos tomado una muestra de 292 estudiantes de ambos sexos, de los cuales 157 pertenecen al primer año y 135 al cuarto año. La investigación tiene como base la teoría establecida por J. Holland, quién en cuya tesis central sostiene que “la elección de la carrera representa una extensión de la personalidad”. Según esta teoría las personas eligen una determinada profesión según sea su tipo de personalidad predominante, para lo cual establece seis tipos de personalidad que son: realista, intelectual, artístico, social, emprendedor, convencional; ubicando al educador dentro del tipo social. El instrumento empleado para determinar el tipo de personalidad predominante de los estudiantes fue el test de Investigación Autodirigida de Jhon Holland, el cual consta de 180 preguntas.

La presente investigación tiene como propósito determinar la influencia del taller de autoestima “Aprendiendo a valorarme, valoro a los demás”, en las habilidades para la vida de las estudiantes de Educación Primaria de la UNT. Es una investigación de diseño cuasi-experimental, porque se trabaja con dos grupos: control y experimental. La población está conformada por 214 estudiantes de Educación primaria matriculadas en el año académico 2017, la muestra objeto de estudio está conformada por 60 estudiantes que integran el grupo control y 60 estudiantes que integran el grupo experimental. Para la recopilación de información se ha utilizado el cuestionario de Habilidades para la Vida, cuya validez y confiabilidad ha sido evaluada por el método Alfa Cronbach y el coeficiente de correlación del mismo y para medir la variable independiente se ha utilizado una guía de observación. De los resultados del pretest obtenidos se observa que la mayoría de las estudiantes del grupo control se encuentra en nivel bajo con un 90% y en el grupo experimental en el nivel bajo con un 88%. Al grupo experimental se aplicó el Taller de Autoestima “Aprendiendo a valorarme valoro a los demás” que contiene 10 sesiones.

La presente investigación tiene como objetivo general  determinar la influencia del programa de cultura ambiental en las actitudes ecológicas en los estudiantes del tercer grado de Educación Secundaria del distrito de Angasmarca- La Libertad, año 2017. La  investigación es de tipo experimental y el diseño es cuasi experimental porque trabaja con dos grupos: control y experimental, con pre-test y pos-test. La  población está compuesta por 420 estudiantes matriculados en el año lectivo 2017, la  muestra objeto de estudio está  constituida por 126 estudiantes, donde los 63 conformaron el grupo control y 63  conformaron el grupo experimental. En la recopilación de información se ha utilizado el cuestionario de Actitudes Ecológicas, cuya validez y confiabilidad ha sido evaluada por el método Alfa Cronbach y el coeficiente de correlación del mismo y para medir la variable independiente se ha utilizado una guía de observación. De los resultados del pretest obtenidos se observa que la mayoría de las estudiantes del grupo control se encuentra en nivel bajo 49,4% y en el grupo experimental en el nivel bajo con un 47,6%. 

A study and review of the magmatic units that make up the Permian-Triassic Intracratonic Magmatic Corridor of La Pampa (CMPT-LP), south-central Argentina, has been carried out. New U-Pb SHRIMP ages, Hf isotopic composition, and chemical composition of some units of the CMPT-LP have been obtained, i.e. 1) Chacharramendi Syenogranite, age 254.7 ± 1.3 Ma (Late Permian, Lopingian), Hf model age of 1640 Ma with εHf average of -5.68; 2) Lihue Calel Rhyolite, 239.3 ± 1.5 Ma (Middle Triassic), Hf model age of 1640 Ma with εHf average -5.56. This indicates that the two dated units were crystallized from a mantle-derived melt that incorporated crust of late Statherian up to Calymmian age, taking also into account a Nd model age of 1483 Ma for the more distal (southeasternmost) sector (López Lecube Granite) of the CMPT-LP obtained by other authors. New geochemical data reported here, analyzed together with previous geochemical data, denote the anorogenic signature –intraplate environment– of the CMPT-LP magmatic corridor, highlighting its consistency with A1-type granites due to the similarity of their sources with those from which the oceanic island basalts (OIB) derive, as evidenced, e.g., by Y/Nb ratios <1.2. The classification of the rocks of the CMPT-LP mainly within the high potassium type is also consistent with its occurrence in an intraplate tectonic environment. The magmatism in the CMPT-LP has been considered as part of the Choiyoi Group, which is also related to late Permian to Early Triassic extension. Nevertheless, there is a marked contrast between the anorogenic environment of the CMPT-LP and the orogenic context of the Choiyoi Magmatic Arc. For this reason, the convenience of excluding the CMPT-LP from the Choiyoi Group is analyzed. In addition, the tectonic frames of the orogenic belts adjoining the CMPT-LP –San Rafael (or Sanrafaelic, or Choiyoi Arc-retroarc) and Northpatagonian Gondwanide belts– are compared briefly.

Forest fires, considered as free and not programmed fire propagation, are perturbations that greatly alter ecosystems. During fires, variable quantities of charcoal particles are produced by the burning vegetation, which can be later deposited in lacustrine basins. The traditional charcoal size particle model associates the > 100 µm primary particles to local fire events, within the watershed, and the < 100 µm particles are linked to regional fire events, outside the watershed. Fires can be related with favorable climatic conditions, but in tectonically active areas like the basin of Mexico, volcanism can also be a factor producing fires and charcoal particles. We document the history, intensity and frequency of fires recorded in the lacustrine sediments of lake Chalco (core CHAVII-11), by performing a high-resolution charcoal particle analysis in sediments deposited before and after three main volcanic events.  The sources of these events had different distances to lake Chalco: Tláhuac tephra (TTH; 28690 years cal BP), probably produced by the Teuhtli volcano, was a local event; the Tutti Frutti Pumice (PTF; 17000 years cal BP) produced by the Popocatépetl volcano, was an extra-local event and the Upper Toluca Pumice (PTS; 12300 years cal BP) produced by the Nevado de Toluca volcano, was a regional event.  Charcoal accumulation rates (CHAR) and distribution of size particles indicate that paleoclimate was a direct factor defining the intensity and recurrence of fires before and after volcanic activity, as climate defines vegetation type and density, and therefore fuel availability.  Fires before and after the TTH were frequent, local and intense in comparison with fires reconstructed before or after the PTF and PTS events. CHAR values were lower during the more widespread PTF event, than for the local TTH event, although the highest CHAR values were recorded for the most distant, regional, and intense PTS event. These results show that charcoal accumulation rates during the volcanic events in central Mexico cannot be interpreted following traditional model of charcoal particle dispersion. This model have important restrictions in active volcanic regions such as central Mexico.

Taxco de Alarcón is an important mining site in Mexico. The town is a well-known tourist destination where the potable water quality is important for guaranteeing the health of the users. Due to the altitude of the city, the surface and rain water are the main sources of water. Thus, the aims of this study were to characterize i) the composition and chemical speciation of particulate matter suspended in water to determine the content of potentially toxic elements, and ii) the chemical and bacteriological composition of the potable water of Taxco de Alarcón, Guerrero, Mexico, according to the Mexican official norm NOM-127-SSA1-1994. The analyzed representative samples were taken from the municipal water distribution network, the water treatment plant, the Chacuhalco spring and a mixture of the waters of the Chontalcuatlán river, the Tenería spring, and the San Marcos and El Sombrerito dams. According to the results, 94 % of the analyzed samples did not comply with the standard NOM-127-SSA1-1994. Moreover, the distribution of the analyzed elements in the different chemical fractions of the particulate matter showed that the highest concentration of Cd (4.17 mg∙kg-1) is associated with the carbonate fraction. This means Cd is moderately bioavailable. On the other hand, the highest concentrations of Pb, Zn, Mn and Cu (62.2, 42.3, 243 and 1026 mg∙kg-1, respectively) were detected in the Fe-Mn oxyhydroxide fraction, also considered as moderately bioavailable, whereas the highest concentrations of As, Fe and V (24.0, 7583 and 31.3 mg∙kg-1, respectively) were associated with the residual fraction, considered as non-bioavailable. The results indicate that, to improve the quality of potable water, modifications must be incorporated along the water treatment processes, and in the distribution network and management.

In the last years several exploratory wells have been drilled in Mexico City down to 2000 m depth, with the aim to explore deep aquifers to cover the water deficiency in the metropolitan area. In particular, in the Agricola Oriental 2C well, located in the Iztacalco municipality, several cores were recovered; one of them is 9 m long, located between 1550 and 1559 m depth. This core is situated close to the contact between an Oligocene volcanic unit and a Cretaceous limestone at ~1560 m depth. The study core shows that the volcanic rocks are affected by an important number of fractures, which can be divided into two families according to their intersection relationships and fill material (F1 and F2). The younger fractures (F2) are related with a fault, informally named here as Agricola Oriental fault, which sets in tectonic contact the sedimentary and the volcanic rocks. The fractures were characterized through a detailed analysis of their number, geometry and spatial arrangement, using the scan line method and taking into account both families of fractures. These variables were expressed such as fracture intensity, box and correlation fractal dimensions, Lyapunov exponent, variation coefficient, and cumulative frequency exponent. Our results show that the spacing between fractures and the aperture follow a power law in a log-log graph of the cumulative frequency analysis that results in a fractal behavior. The pattern values showed in the fracture intensity, fractal dimension, Lyapunov exponent, and aperture cumulative frequency exponent progressively diminish as the distance to the fault increases. In turn, the coefficients of variation and spacing cumulative frequency exponent have a different pattern: their values increase with the distance to the fault. These behaviors are typical of a common shear zone; however, in our analysis, the anomalous variation of the study parameters in the fault damaged zone is related to the presence of a previous fracture system (F1). These fractures induced an important increase in the amount of fractures and change their distribution in the damage zone. In addition, based on the fracture characteristics, we proposed that the fault found in the well is related to the northern limit of Santa Catarina graben and has an ENE-WSW orientation.