A theoretical and didactic approach to the mini-text is proposed: a conceptual category for analy... more A theoretical and didactic approach to the mini-text is proposed: a conceptual category for analysis and pedagogic treatment of non-literary-short-texts. The proposal is based on four theoretical paradigms: one related to the bakhtinian approach of enunciation and discourse genres; other circumscribed by text linguistics and discourse studies; a third approach related to flash fiction theory and criticism; and a fourth paradigm that suggests taking advantage of immersion and entertainment features that underlay videogames as mechanisms to promote meaningful learnings
El dengue es una enfermedad epidemica muy comun en regiones tropicales y sub tropicales. La elimi... more El dengue es una enfermedad epidemica muy comun en regiones tropicales y sub tropicales. La eliminacion de criaderos y el control vectorial se encuentran entre las medidas en la lucha contra la enfermedad. Se han desarrollado diversas estrategias para mantener bajo indice poblacional del mosquito. Diversas investigaciones se han enfocado a la busqueda de nuevos productos naturales, con actividad insecticida y larvicida, que puedan controlar la poblacion de mosquitos, sin presentar riesgos al humano y animales domesticos. Realizamos una serie de bioensayos con extractos acuosos de plantas paraguayas, Annona muricata (chirimoya); Bulnesia sarmentoi (palo santo); Melia azederach (paraiso); Zanthoxylum chiloperone var. Angustifolium (tembetary hu) y Bixa orellana (uruku), para comprobar en cada planta, su actividad y eficacia como larvicida, contra larvas del mosquito Aedes agypti. Dichas larvas, fueron colectadas de diversas zonas de Asuncion y el Gran Asuncion, durante la epidemia de ...
El presente trabajo propone el desarrollo de algunas competencias en los docentes enformacion par... more El presente trabajo propone el desarrollo de algunas competencias en los docentes enformacion para el uso de las tecnologias de la informacion y la comunicacion (en adelante,TIC). En los actuales escenarios educativos, el uso de ambientes basados en computador,es cada dia mas comun en los procesos de aprendizaje de los estudiantes y ello implica laparticipacion activa de los docentes en el diseno y desarrollo de escenarios computacionalesque sean flexibles a las preferencias de aprendizaje de los sujetos y que se adapten a susdiferencias individuales. En esta medida, dichos escenarios podrian ser utilizados por losestudiantes de forma eficaz y de esta manera, alcanzar las metas de aprendizaje deseadas.Esta propuesta se basa en los desarrollos que adelanta el grupo de investigacion Cognitekde la Universidad Pedagogica Nacional.
Dengue is an common epidemic disease in tropical and subtropical regions. The elimination of bree... more Dengue is an common epidemic disease in tropical and subtropical regions. The elimination of breeding sites and vector control are among the most widely used measures in the fight against the disease. Many strategies have been developed to keep low rates of mosquito populations. Several research studies have been focused on finding natural products with insecticide and larvicide activity that could effectively control these mosquito populations without risks for the human populations and domestic animals. In this work, we have performed a series of bioassays with aqueous extracts of Paraguayan plants: Annona muricata (cherimoya), Bulnesia sarmentoi (palo santo), Melia azederach (paradise), Zanthoxylum chiloperone var. Angustifolium (tembetary hú) and Bixa orellana (uruku) in order to check the effectiveness and activity as larvicide of each plant gainst Aedes aegypti larvae. The larvae were collected in various areas of Asuncion and Great Asuncion during the yellow fever outbreak of...
Two combretastatin heteroanalogues, called SAAS-41 and SAAS-59, were selected within a series of ... more Two combretastatin heteroanalogues, called SAAS-41 and SAAS-59, were selected within a series of 44 compounds previously evaluated in vitro against Leishmania spp, and have now been assayed in vivo on BALB/c mice, infected with amastigotes of L. amazonensis. They were administered by three different routes. The most efficient compound, SAAS-59, administered subcutaneously (50 mg/kg), led to fair reductions of lesion size (-86.4%) and parasitic load (-97.4%), in percentages fairly higher than those observed for the reference drug glucantime at the dose of 100 mg/kg (-49.1% size; -60.1% load). Intralesional and oral administration of the product at the same dose, also induced significant decreases (-91.4% and -77.3% respectively) of the lesion size, but it did not show significant reductions of the parasitic load.
El presente artículo recoge los principales hallazgos de una exploración de la condición de géner... more El presente artículo recoge los principales hallazgos de una exploración de la condición de género (masculino-femenino),frente a las posibles asociaciones que los estudiantes establecen entre contenidos y entornos de aprendizaje.Del estudio participaron 298 estudiantes de secundaria de colegios ubicados en distintas localidades de la ciudad deBogotá (Colombia), a quienes se les suministró un cuestionario de 31 ítems que indagaban por la frecuencia con que los participantes recurren a los distintos escenarios para aprender distintas clases de contenidos. Los resultados evidencian la preferencia masculina por la exploración de espacios virtuales para acceder a la información de diverso tipo, mientras que las mujeres recurren a este escenario principalmente como parte de su proceso de aprendizaje de socialización. Para el acceso a otros contenidos las mujeres prefieren el hogar y en general espacios interiores o personalizados, a diferencia de los hombres, quienes manifiestan menos pre...
During the last two decades, interpersonal regulation in natural and digital learning environment... more During the last two decades, interpersonal regulation in natural and digital learning environments has gained importance. Ever since the first conceptual and methodological precisions regarding collaborative learning were made, educational psychology has focused its interest on analyzing collective regulation of motivation, cognition, and behavior. Despite the fact that the body of research on co-regulation has grown, emerging epistemological frameworks evidence a lack of conceptual and theoretical clarity. In response to this situation, the authors propose a conceptual approach in order to address interpersonal regulation in four aspects: first, they describe three learning theories which have been used to study co-regulation. Second, the authors recommend a conceptual delimitation of terms regarding the learning theories on social regulation. Third, they highlight diffuse boundaries between theoretical approaches and terms used in the literature on co-regulation. Finally, the authors suggest some challenges the researchers in this field face.
The research’s objective is to evaluate the differential effect that a metacognitive scaffolding ... more The research’s objective is to evaluate the differential effect that a metacognitive scaffolding for information web searches has on learning achievement of high school students with different cognitive style in the field dependence and independence dimension and on learning style in the dimension proposed by Honey and Alonso known as CHAEA. One hundred and four students from a school in the city of Bogotá, Colombia participated in the study. The research was quasi-experimental and was conducted with three 10th-grade groups, which worked with three scaffolding versions: fixed, optional, and without scaffolding. A multivariate analysis of covariance established that the fixed scaffolding favored learning achievement. Regarding cognitive style in the field dependence and independence dimension, the findings allow to conclude that the field independent students exhibited better academic performances in the presence of a fixed scaffolding when compared with the field dependent students....
Sobre la base de los planteamientos básicos del aprendizaje situado, este artículo presenta los r... more Sobre la base de los planteamientos básicos del aprendizaje situado, este artículo presenta los resultados de un estudio que explora los escenarios donde los escolares de secundaria buscan información o adquieren ciertos conocimientos específicos. Metodológicamente, el estudio aplicó el enfoque de Teoría de Facetas para identificar las variables involucradas en las conexiones posibles entre escenarios y contenidos de aprendizaje. 298 estudiantes de secundaria (135 hombres y 163 mujeres) respondieron un cuestionario sobre la frecuencia de búsqueda de cierto tipo de contenidos en ciertos escenarios. Los resultados confirmaron la faceta construida para los escenarios y reconfiguraron la faceta de contenidos en una polaridad. A partir de estos resultados, se elaboraron conclusiones respecto al alcance de los planteamientos del aprendizaje situado y se formularon interrogantes para futuros estudios que exploren el papel que juegan los nuevos escenarios de aprendizaje en la formación de los estudiantes.
Tropical medicine and parasitology : official organ of Deutsche Tropenmedizinische Gesellschaft and of Deutsche Gesellschaft für Technische Zusammenarbeit (GTZ), 1995
Five Paraguayan Trypanosoma cruzi strains, isolated from acute chagasic patients, were studied by... more Five Paraguayan Trypanosoma cruzi strains, isolated from acute chagasic patients, were studied by their behavior in BALB/c mice, metacyelogenesis, bio-metry of metacyclic forms and lectin agglutination. Early and intermediate parasitemic peaks were observed and the strains did not show high virulence. Metacyclogenesis capacity was not higher than 50% in all cases and there were no considerable differences in the biometry. They all belong to WGA-type strains according to the lectin agglutination assays except for one strain that agglutinated with WGA and PNA lectins. Although previous schizodeme analysis of these strains showed rather homogeneous profiles, biological features were quite heterogeneous.
... The Milan expertise of 1399 was studied in Paul Frankl, "The Secret of the Medieval Maso... more ... The Milan expertise of 1399 was studied in Paul Frankl, "The Secret of the Medieval Masons," Art Bulletin, xxvii, 1, 1945, 46-61; and James Ackerman, "Ars Sine Scientia Nihil Est, Gothic Theory of Architecture at the Cathedral of Milan," Art Bulletin, xxxI, 2 ... Lajwe uvr,, e uz So6. ...
Twelve species of nematodes comprising 9 genera were recovered from the gastrointestinal tract of... more Twelve species of nematodes comprising 9 genera were recovered from the gastrointestinal tract of 2 Euphractus sexcinctus and 2 Dasypus novemcinctus captured in the Department of San Pedro, Paraguay. All armadillos were infected with 1 or more species of nematode. The following nematodes were recovered: Mazzia mazzia, Spirura guianensis, Trichohelix tuberculata, Ancylostoma sp., Moennigia complexus, Moennigia pintoi, Ascaris dasypodina, Cruzia tentaculata, Aspidodera fasciata, Aspidodera scoleciformis, Aspidodera esperanzae n. sp., and Heterakinae gen. sp. This report describes a new species of the Aspidodera nematode, Aspidodera esperanzae n. sp., the first species to be reported bearing cephalic cordons made up of 7 longitudinal loops in the subfamily of Aspidoderinae. This study also documents a new host record for S. guianensis and shows a new geographical distribution in Paraguay for M. mazzia, S. guianensis, T. tuberculata, M. complexus, and M. pintoi.
European Journal of Medicinal Chemistry, Sep 1, 2008
The synthesis and potent antiprotozoal activity of 14-hydroxylunularin, a natural hydroxybibenzyl... more The synthesis and potent antiprotozoal activity of 14-hydroxylunularin, a natural hydroxybibenzyl bryophyte constituent is reported. 14-Hydroxylunularin was highly active in vitro assays against culture and intracellular forms of Leishmania spp. and Trypanosoma. cruzi, in absence of cytotoxicity against mammalian cells. Preliminary structureeactivity relationship studies showed that the reported bioactivity depends on hybridization at the carbonecarbon bridge, position and number of free hydroxy group on the aromatic rings. The reported results were also in agreement with the in silico prediction using Non-Stochastic Quadratic Fingerprints-based algorithms. The same compound also showed antiprotozoal activity in Leishmania spp. infected mice by oral and subcutaneous administration routes, with an optimal treatment of a daily subcutaneous administration of 10 mg/kg of body weight for 15 days. This study suggested that 14-hydroxylunularin may be chosen as a new candidate in the development of leishmanicidal therapy.
Tropical medicine and parasitology : official organ of Deutsche Tropenmedizinische Gesellschaft and of Deutsche Gesellschaft für Technische Zusammenarbeit (GTZ), 1995
Five Paraguayan Trypanosoma cruzi strains, isolated from acute chagasic patients, were studied by... more Five Paraguayan Trypanosoma cruzi strains, isolated from acute chagasic patients, were studied by their behavior in BALB/c mice, metacyelogenesis, bio-metry of metacyclic forms and lectin agglutination. Early and intermediate parasitemic peaks were observed and the strains did not show high virulence. Metacyclogenesis capacity was not higher than 50% in all cases and there were no considerable differences in the biometry. They all belong to WGA-type strains according to the lectin agglutination assays except for one strain that agglutinated with WGA and PNA lectins. Although previous schizodeme analysis of these strains showed rather homogeneous profiles, biological features were quite heterogeneous.
A theoretical and didactic approach to the mini-text is proposed: a conceptual category for analy... more A theoretical and didactic approach to the mini-text is proposed: a conceptual category for analysis and pedagogic treatment of non-literary-short-texts. The proposal is based on four theoretical paradigms: one related to the bakhtinian approach of enunciation and discourse genres; other circumscribed by text linguistics and discourse studies; a third approach related to flash fiction theory and criticism; and a fourth paradigm that suggests taking advantage of immersion and entertainment features that underlay videogames as mechanisms to promote meaningful learnings
El dengue es una enfermedad epidemica muy comun en regiones tropicales y sub tropicales. La elimi... more El dengue es una enfermedad epidemica muy comun en regiones tropicales y sub tropicales. La eliminacion de criaderos y el control vectorial se encuentran entre las medidas en la lucha contra la enfermedad. Se han desarrollado diversas estrategias para mantener bajo indice poblacional del mosquito. Diversas investigaciones se han enfocado a la busqueda de nuevos productos naturales, con actividad insecticida y larvicida, que puedan controlar la poblacion de mosquitos, sin presentar riesgos al humano y animales domesticos. Realizamos una serie de bioensayos con extractos acuosos de plantas paraguayas, Annona muricata (chirimoya); Bulnesia sarmentoi (palo santo); Melia azederach (paraiso); Zanthoxylum chiloperone var. Angustifolium (tembetary hu) y Bixa orellana (uruku), para comprobar en cada planta, su actividad y eficacia como larvicida, contra larvas del mosquito Aedes agypti. Dichas larvas, fueron colectadas de diversas zonas de Asuncion y el Gran Asuncion, durante la epidemia de ...
El presente trabajo propone el desarrollo de algunas competencias en los docentes enformacion par... more El presente trabajo propone el desarrollo de algunas competencias en los docentes enformacion para el uso de las tecnologias de la informacion y la comunicacion (en adelante,TIC). En los actuales escenarios educativos, el uso de ambientes basados en computador,es cada dia mas comun en los procesos de aprendizaje de los estudiantes y ello implica laparticipacion activa de los docentes en el diseno y desarrollo de escenarios computacionalesque sean flexibles a las preferencias de aprendizaje de los sujetos y que se adapten a susdiferencias individuales. En esta medida, dichos escenarios podrian ser utilizados por losestudiantes de forma eficaz y de esta manera, alcanzar las metas de aprendizaje deseadas.Esta propuesta se basa en los desarrollos que adelanta el grupo de investigacion Cognitekde la Universidad Pedagogica Nacional.
Dengue is an common epidemic disease in tropical and subtropical regions. The elimination of bree... more Dengue is an common epidemic disease in tropical and subtropical regions. The elimination of breeding sites and vector control are among the most widely used measures in the fight against the disease. Many strategies have been developed to keep low rates of mosquito populations. Several research studies have been focused on finding natural products with insecticide and larvicide activity that could effectively control these mosquito populations without risks for the human populations and domestic animals. In this work, we have performed a series of bioassays with aqueous extracts of Paraguayan plants: Annona muricata (cherimoya), Bulnesia sarmentoi (palo santo), Melia azederach (paradise), Zanthoxylum chiloperone var. Angustifolium (tembetary hú) and Bixa orellana (uruku) in order to check the effectiveness and activity as larvicide of each plant gainst Aedes aegypti larvae. The larvae were collected in various areas of Asuncion and Great Asuncion during the yellow fever outbreak of...
Two combretastatin heteroanalogues, called SAAS-41 and SAAS-59, were selected within a series of ... more Two combretastatin heteroanalogues, called SAAS-41 and SAAS-59, were selected within a series of 44 compounds previously evaluated in vitro against Leishmania spp, and have now been assayed in vivo on BALB/c mice, infected with amastigotes of L. amazonensis. They were administered by three different routes. The most efficient compound, SAAS-59, administered subcutaneously (50 mg/kg), led to fair reductions of lesion size (-86.4%) and parasitic load (-97.4%), in percentages fairly higher than those observed for the reference drug glucantime at the dose of 100 mg/kg (-49.1% size; -60.1% load). Intralesional and oral administration of the product at the same dose, also induced significant decreases (-91.4% and -77.3% respectively) of the lesion size, but it did not show significant reductions of the parasitic load.
El presente artículo recoge los principales hallazgos de una exploración de la condición de géner... more El presente artículo recoge los principales hallazgos de una exploración de la condición de género (masculino-femenino),frente a las posibles asociaciones que los estudiantes establecen entre contenidos y entornos de aprendizaje.Del estudio participaron 298 estudiantes de secundaria de colegios ubicados en distintas localidades de la ciudad deBogotá (Colombia), a quienes se les suministró un cuestionario de 31 ítems que indagaban por la frecuencia con que los participantes recurren a los distintos escenarios para aprender distintas clases de contenidos. Los resultados evidencian la preferencia masculina por la exploración de espacios virtuales para acceder a la información de diverso tipo, mientras que las mujeres recurren a este escenario principalmente como parte de su proceso de aprendizaje de socialización. Para el acceso a otros contenidos las mujeres prefieren el hogar y en general espacios interiores o personalizados, a diferencia de los hombres, quienes manifiestan menos pre...
During the last two decades, interpersonal regulation in natural and digital learning environment... more During the last two decades, interpersonal regulation in natural and digital learning environments has gained importance. Ever since the first conceptual and methodological precisions regarding collaborative learning were made, educational psychology has focused its interest on analyzing collective regulation of motivation, cognition, and behavior. Despite the fact that the body of research on co-regulation has grown, emerging epistemological frameworks evidence a lack of conceptual and theoretical clarity. In response to this situation, the authors propose a conceptual approach in order to address interpersonal regulation in four aspects: first, they describe three learning theories which have been used to study co-regulation. Second, the authors recommend a conceptual delimitation of terms regarding the learning theories on social regulation. Third, they highlight diffuse boundaries between theoretical approaches and terms used in the literature on co-regulation. Finally, the authors suggest some challenges the researchers in this field face.
The research’s objective is to evaluate the differential effect that a metacognitive scaffolding ... more The research’s objective is to evaluate the differential effect that a metacognitive scaffolding for information web searches has on learning achievement of high school students with different cognitive style in the field dependence and independence dimension and on learning style in the dimension proposed by Honey and Alonso known as CHAEA. One hundred and four students from a school in the city of Bogotá, Colombia participated in the study. The research was quasi-experimental and was conducted with three 10th-grade groups, which worked with three scaffolding versions: fixed, optional, and without scaffolding. A multivariate analysis of covariance established that the fixed scaffolding favored learning achievement. Regarding cognitive style in the field dependence and independence dimension, the findings allow to conclude that the field independent students exhibited better academic performances in the presence of a fixed scaffolding when compared with the field dependent students....
Sobre la base de los planteamientos básicos del aprendizaje situado, este artículo presenta los r... more Sobre la base de los planteamientos básicos del aprendizaje situado, este artículo presenta los resultados de un estudio que explora los escenarios donde los escolares de secundaria buscan información o adquieren ciertos conocimientos específicos. Metodológicamente, el estudio aplicó el enfoque de Teoría de Facetas para identificar las variables involucradas en las conexiones posibles entre escenarios y contenidos de aprendizaje. 298 estudiantes de secundaria (135 hombres y 163 mujeres) respondieron un cuestionario sobre la frecuencia de búsqueda de cierto tipo de contenidos en ciertos escenarios. Los resultados confirmaron la faceta construida para los escenarios y reconfiguraron la faceta de contenidos en una polaridad. A partir de estos resultados, se elaboraron conclusiones respecto al alcance de los planteamientos del aprendizaje situado y se formularon interrogantes para futuros estudios que exploren el papel que juegan los nuevos escenarios de aprendizaje en la formación de los estudiantes.
Tropical medicine and parasitology : official organ of Deutsche Tropenmedizinische Gesellschaft and of Deutsche Gesellschaft für Technische Zusammenarbeit (GTZ), 1995
Five Paraguayan Trypanosoma cruzi strains, isolated from acute chagasic patients, were studied by... more Five Paraguayan Trypanosoma cruzi strains, isolated from acute chagasic patients, were studied by their behavior in BALB/c mice, metacyelogenesis, bio-metry of metacyclic forms and lectin agglutination. Early and intermediate parasitemic peaks were observed and the strains did not show high virulence. Metacyclogenesis capacity was not higher than 50% in all cases and there were no considerable differences in the biometry. They all belong to WGA-type strains according to the lectin agglutination assays except for one strain that agglutinated with WGA and PNA lectins. Although previous schizodeme analysis of these strains showed rather homogeneous profiles, biological features were quite heterogeneous.
... The Milan expertise of 1399 was studied in Paul Frankl, "The Secret of the Medieval Maso... more ... The Milan expertise of 1399 was studied in Paul Frankl, "The Secret of the Medieval Masons," Art Bulletin, xxvii, 1, 1945, 46-61; and James Ackerman, "Ars Sine Scientia Nihil Est, Gothic Theory of Architecture at the Cathedral of Milan," Art Bulletin, xxxI, 2 ... Lajwe uvr,, e uz So6. ...
Twelve species of nematodes comprising 9 genera were recovered from the gastrointestinal tract of... more Twelve species of nematodes comprising 9 genera were recovered from the gastrointestinal tract of 2 Euphractus sexcinctus and 2 Dasypus novemcinctus captured in the Department of San Pedro, Paraguay. All armadillos were infected with 1 or more species of nematode. The following nematodes were recovered: Mazzia mazzia, Spirura guianensis, Trichohelix tuberculata, Ancylostoma sp., Moennigia complexus, Moennigia pintoi, Ascaris dasypodina, Cruzia tentaculata, Aspidodera fasciata, Aspidodera scoleciformis, Aspidodera esperanzae n. sp., and Heterakinae gen. sp. This report describes a new species of the Aspidodera nematode, Aspidodera esperanzae n. sp., the first species to be reported bearing cephalic cordons made up of 7 longitudinal loops in the subfamily of Aspidoderinae. This study also documents a new host record for S. guianensis and shows a new geographical distribution in Paraguay for M. mazzia, S. guianensis, T. tuberculata, M. complexus, and M. pintoi.
European Journal of Medicinal Chemistry, Sep 1, 2008
The synthesis and potent antiprotozoal activity of 14-hydroxylunularin, a natural hydroxybibenzyl... more The synthesis and potent antiprotozoal activity of 14-hydroxylunularin, a natural hydroxybibenzyl bryophyte constituent is reported. 14-Hydroxylunularin was highly active in vitro assays against culture and intracellular forms of Leishmania spp. and Trypanosoma. cruzi, in absence of cytotoxicity against mammalian cells. Preliminary structureeactivity relationship studies showed that the reported bioactivity depends on hybridization at the carbonecarbon bridge, position and number of free hydroxy group on the aromatic rings. The reported results were also in agreement with the in silico prediction using Non-Stochastic Quadratic Fingerprints-based algorithms. The same compound also showed antiprotozoal activity in Leishmania spp. infected mice by oral and subcutaneous administration routes, with an optimal treatment of a daily subcutaneous administration of 10 mg/kg of body weight for 15 days. This study suggested that 14-hydroxylunularin may be chosen as a new candidate in the development of leishmanicidal therapy.
Tropical medicine and parasitology : official organ of Deutsche Tropenmedizinische Gesellschaft and of Deutsche Gesellschaft für Technische Zusammenarbeit (GTZ), 1995
Five Paraguayan Trypanosoma cruzi strains, isolated from acute chagasic patients, were studied by... more Five Paraguayan Trypanosoma cruzi strains, isolated from acute chagasic patients, were studied by their behavior in BALB/c mice, metacyelogenesis, bio-metry of metacyclic forms and lectin agglutination. Early and intermediate parasitemic peaks were observed and the strains did not show high virulence. Metacyclogenesis capacity was not higher than 50% in all cases and there were no considerable differences in the biometry. They all belong to WGA-type strains according to the lectin agglutination assays except for one strain that agglutinated with WGA and PNA lectins. Although previous schizodeme analysis of these strains showed rather homogeneous profiles, biological features were quite heterogeneous.
Uploads
Papers by Luis Sanabria