Experiencias estudiantiles de adolescentes rurales en México

En la presente ponencia presento algunos de los resultados de la investigación “Más allá de los muros. Adolescencias rurales y experiencias estudiantiles en telesecundarias”. Con ella me propuse comprender las maneras como los adolescentes que cursan la educación secundaria en contextos rurales construyen sus experiencias estudiantiles, a partir del análisis de los procesos de socialización y subjetivación en los que participan, de las lógicas de acción estratégica que desarrollan, y de las interrelaciones entre estos procesos, así como de las tensiones producto de la participación de los estudiantes en distintos ámbitos de actuación.Facultad de Humanidades y Ciencias de la Educació

“Experiencias estudiantiles de adolescentes rurales: Un acercamiento a la faceta subjetiva de la telesecundaria en México

La experiencia estudiantil en los contextos rurales se ve configurada por los procesos de transformación socioeconómica y cultural profundos que los caracterizan, los cuales desdibujan las fronteras entre lo rural y lo urbano, produciendo nuevas, complejas y heterogéneas realidades sociales, donde las oportunidades sociales también son diversas. En estos contextos, las telesecundarias se constituyen en espacios de vida adolescente donde tienen lugar procesos importantes de redefinición y resignificación individuales y sociales a través de la experiencia estudiantil, la cual pone en contacto la cultura juvenil y la escolar fusionando las maneras diversas de ser adolescente y estudiante. La experiencia estudiantil también es parte de la faceta subjetiva del sistema escolar, es por ello que a partir de su análisis se puede percibir la existencia de un sistema heterogéneo, pero también inequitativo, que otorga oportunidades educativas desiguales a los jóvenes mexicanos, ello a pesar de los esfuerzos que realizan algunos profesores comprometidos con su labor docente, del acercamiento que en algunas escuelas hay entre profesores y estudiantes, y de la alta valoración que las telesecundarias tienen en los contextos rurales entre algunos adolescentes, quienes encuentran en ellas un espacio privilegiado para la convivencia juvenil, para el desarrollo de competencias y de algunas alternativas para construirse un futuro distinto al de pobreza y marginación al que el medio parece condenarlos

Identificación de elementos en cis que regulan la expresión de genes de adhesinas en Candida glabrata

Tesis (Doctorado en Ciencias en Biología Molecular)"Candida glabrata es una levadura comensal de mamíferos que bajo ciertas condiciones que debilitan el sistema inmune del huésped se comporta como patógena. Entre sus factores de virulencia se encuentran proteínas de pared que median la adherencia a distintas superficies biológicas. Los genes EPA que codifican estas proteínas se encuentran localizados en regiones subteloméricas. Dichos genes, o genes reporteros insertados en éstas regiones se encuentran reprimidos, fenómeno llamado silenciamiento subtelomérico o TPE. La formación de la cromatina silenciosa depende de las proteínas Sir2, Sir3, Sir4, y en diferente medida de Rap1, Rif1, Ku70 y Ku80 en los diferentes telómeros. En C. glabrata así como en S. cerevisiae las regiones subteloméricas contienen además elementos en cis importantes en la formación y propagación de la cromatina represiva. Estos elementos funcionan como protosilenciadores porque incrementan la acción de silenciadores localizados en su cercanía, mientras que no pueden mediar el silenciamiento por sí solos. En este trabajo se identificó una región protosilenciadora (Sil2126), localizada entre EPA3 y el telómero E-R. Las propiedades de Sil2126 se estudiaron mediante un reportero URA3 en distintas ubicaciones cromosómicas. Se encontró que el efecto de Sil2126 es dependiente de las proteínas Sir2, Sir3, Sir4, Rap1, Rif1 y es independiente de las proteínas Ku70 y Ku80. Sil2126 presenta una composición modular con distintos elementos internos no funcionales de forma individual. El funcionamiento de Sil2126 es dependiente tanto de su distancia al telómero como del contexto subtelomérico particular, ya que este elemento puede mediar el silenciamiento de URA3 a 32 kb de su telómero nativo E-R, mas no a una distancia similar de 34 kb en el telómero E-L. Sil2126 pierde su funcionalidad si se coloca a una distancia de 50 kb de su propio telómero o cuando se integra en regiones internas de los cromosomas F, L y M a más de 200 kb del telómero. Las propiedades de Sil2126 son dependientes de su orientación relativa respecto al gen reportero y respecto al telómero. A la fecha, todos los telómeros estudiados de S. cerevisiae y C. glabrata dependen de Ku70 y Ku80 para el silenciamiento; sin embargo, el elemento Sil2126 así como el telómero E-R en el que se encuentra ubicado, aparentemente no dependen de Ku70 y Ku80 para su funcionamiento. En este trabajo se encontró que la participación de Ku70 y Ku80 en el silenciamiento subtelomérico E-R se encuentra enmascarada por el efecto redundante que presenta junto con Sil2126. Dicho efecto solo se manifiesta en mutantes dobles hdf1Δ/silΔ y hdf2Δ/silΔ. Se propone que interacciones funcionales entre el telómero y elementos internos al cromosoma como el protosilenciador Sil2126, están involucradas en las características y grado de propagación del silenciamiento en cada telómero. El establecimiento del silenciamiento puede ser anulado por la presencia de un promotor fuerte que establezca una barrera en la formación o propagación del silenciamiento, como es el caso del promotor del gen PGK1.""Candida glabrata is a commensal yeast in mammals that can become a pathogen when the host defenses are compromised. One of the most important virulence factors of C. glabrata are the adhesin proteins that mediate adherence to different surfaces. These proteins are encoded by the EPA genes which are localized in regions close to the telomeres. These subtelomeric regions are assembled as a transcriptionally repressed chromatin so that native or reporter genes inserted at these sites are not expressed, a process called subtelomeric silencing or TPE. Silenced chromatin depends on proteins Sir2, Sir3, Sir4, and to different degrees on Rap1, Rif1, Ku70 and Ku80 depending on the particular telomere. C. glabrata and S. cerevisiae subtelomeric regions contain important cis elements for the establishment and spreading of heterochromatin. These elements work as protosilencers because they increase the action of closely localized silencers but they do not establish silencing on their own. In this work, we identified a region with protosilencer properties (Sil2126) between EPA3 and the right telomere of chromosome E (E-R). Sil2126 properties are analyzed by using a URA3 reporter inserted at different genomic locations. It was found that Sil2126 activity is dependent on the main subtelomeric silencing proteins Sir2, Sir3, Sir4, Rap1, Rif1, and is independent of Ku70/Ku80. Sil2126 shows a modular composition with several internal elements that are not functional on their own. The Sil2126 activity is dependent on its relative proximity to the telomere and on the particular subtelomeric context, since Sil2126 mediates silencing 32 kb from its native telomere E-R but not at a similar distance (34 kb) from the opposite telomere on chromosome E (E-L). Sil2126 loses activity when placed at 50 kb of telomere E-R or when it is integrated at internal regions on chromosomes F, L and M that are over 200 kb from the telomere. Sil2126 properties are dependent on its relative orientation with respect to the reporter and the telomere. To date, all the telomeres studied in S. cerevisiae and C. glabrata depend on Ku70 and Ku80 for silencing, however Sil2126 and the E-R telomere apparently do not depend on Ku70/Ku80 for silencing. In this work, it was found that the role of Ku70 and Ku80 on subtelomeric silencing at E-R is masked by the redundant function of Sil2126 on silencing.

Tensiones normativas en la definición del puesto directivo en la educación secundaria. El caso de México.

In 2013 the third article of the Mexican Constitution was reformed. This article regulates the educational services offered by the State. Consequently, a set of standards, known in Mexico, as Parameters and Indicators (PPI) defined the competences of school principals. A year later, the Agreements 97 and 98, published in the eighties, that define the organization and functioning of secondary schools were ratified in their general and technical modalities in the country. This condition led to the fact that the PPIs coexist with those agreements, generating tensions in the regulations that guide the administrative functions. The objective of this paper is to analyze, from a comparative approach, the current documents for the organization of the three modalities of secondary education in Mexico: general, technical and telesecundary. The specific objectives are to analyze the structures of the documents, the reconfiguration of the administrative positions and the review the principal´s roles functions as a result of the reform. Likewise, it suggests that promoting educational policies aimed at strengthening schools autonomy, without modifying the regulatory framework produces different kinds of tensions affecting school organization, as well as the managerial career and roles. It concludes that the principals are in between roles defined by two different administrative models

Tensiones normativas en la definición del puesto directivo en la educación secundaria. El caso de México.

In 2013 the third article of the Mexican Constitution was reformed. This article regulates the educational services offered by the State. Consequently, a set of standards, known in Mexico, as Parameters and Indicators (PPI) defined the competences of school principals. A year later, the Agreements 97 and 98, published in the eighties, that define the organization and functioning of secondary schools were ratified in their general and technical modalities in the country. This condition led to the fact that the PPIs coexist with those agreements, generating tensions in the regulations that guide the administrative functions. The objective of this paper is to analyze, from a comparative approach, the current documents for the organization of the three modalities of secondary education in Mexico: general, technical and telesecundary. The specific objectives are to analyze the structures of the documents, the reconfiguration of the administrative positions and the review the principal´s roles functions as a result of the reform. Likewise, it suggests that promoting educational policies aimed at strengthening schools autonomy, without modifying the regulatory framework produces different kinds of tensions affecting school organization, as well as the managerial career and roles. It concludes that the principals are in between roles defined by two different administrative models

Pot-Pollen and Pot-Honey from Stingless Bees of the Alto Balsas, Michoacán, Mexico: Botanical and Physicochemical Characteristics

The demand for stingless bees’ products (pot-honey and pot-pollen) has increased. No formal quality standards have been defined, which is very complex, because of the variety of species and types of honey specific to each region. For this reason, it is important to deepen the understanding of stingless bees’ honey characteristics. From the above, the aim of this chapter is to present the advances in the characterization of botanical origin of stingless bees’ honey, and the analysis of their physicochemical properties in the Alto Balsas, Michoacán, Mexico, as a way to contribute to the strengthening of new local economic strategies, generating information on the quality of the honey produced in the region

Analysis of a new begomovirus unveils a composite element conserved in the CP gene promoters of several Geminiviridae genera: Clues to comprehend the complex regulation of late genes

"A novel bipartite begomovirus, Blechum interveinal chlorosis virus (BleICV), was characterized at the genome level. Comparative analyses revealed that BleICV coat protein (CP) gene promoter is highly divergent from the equivalent region of other begomoviruses (BGVs), with the single exception of Tomato chino La Paz virus (ToChLPV) with which it shares a 23-bp phylogenetic footprint exhibiting dyad symmetry. Systematic examination of the homologous CP promoter segment of 132 New World BGVs revealed the existence of a quasi-palindromic DNA segment displaying a strongly conserved ACTT-(N7)-AAGT core. The spacer sequence between the palindromic motifs is constant in length, but its sequence is highly variable among viral species, presenting a relaxed consensus (TT)GGKCCCY, which is similar to the Conserved Late Element or CLE (GTGGTCCC), a putative TrAP-responsive element. The homologous CP promoter region of Old World BGVs exhibited a distinct organization, with the putative TATA-box overlapping the left half of the ACTT-N7 composite element. Similar CP promoter sequences, dubbed “TATA-associated composite element” or TACE, were found in viruses belonging to different Geminiviridae genera, hence hinting unsuspected evolutionary relationships among those lineages. To get cues about the TACE function, the regulatory function of the CLE was explored in distinct experimental systems. Transgenic tobacco plants harboring a GUS reporter gene driven by a promoter composed by CLE multimers expressed high beta-glucuronidase activity in absence of viral factors, and that expression was increased by begomovirus infection. On the other hand, the TrAP-responsiveness of a truncated CP promoter of Tomato golden mosaic virus (TGMV) was abolished by site-directed mutation of the only CLE present in it, whereas the artificial addition of one CLE to the -125 truncated promoter strongly enhanced the transactivation level in tobacco protoplasts. These results indicate that the CLE is a TrAP-responsive element, hence providing valuable clues to interpret the recurrent association of the CLE with the TACE. On the basis of the aforesaid direct evidences and the insights afforded by the extensive comparative analysis of BleICV CP promoter, we propose that the TACE might be involved in the TrAP-mediated derepression of CP gene in vascular tissues.

Actividad antihelmíntica in vivo de hojas de Acacia cochliacantha sobre Haemonchus contortus en cabritos Boer

This study aimed to evaluate the effect of supplementing the maintenance diet of Boer goat kids with Acacia cochliacantha leaves. The endpoints evaluated were Haemonchus contortus fecal egg count (FEC) and water and dry matter intake. Two experimental treatments were evaluated on ten recently weaned goat kids (16.850 ± 1.630 kg of initial live weight and three months of age) experimentally infested with H. contortus larvae (L3) (350 larvae per live weight kilogram). Treatment 1 (T1) served as the control and consisted of infested animals without diet supplementation with A. cochliacantha leaves. Treatment 2 (T2) consisted of infested animals fed diets supplemented with 5% of A. cochliacantha leaves. Animals were grouped from highest to lowest based on their FEC. The two animals groups with the highest values were randomly assigned to T1 or T2; this was repeated until completing five repetitions per treatment. The evaluated variables were: FEC (per gram of feces), water intake, and dry matter intake (DMI). The results show that goat kids fed diets with 5% of A. cochliacantha leaves have lower (P 0.05). Se concluye que la adición de hojas de A. cochliacantha en dietas para cabritos tienen actividad antihelmíntica, por lo que esta leguminosa arbórea podría representar una opción en el manejo integral de la nematodiasis de cabritos Boer en crecimiento

Fertilidade de ovelhas Katahdin inseminadas laparoscopicamente com sêmen refrigerado ou criopreservado nos trópicos

El objetivo del estudio fue comparar la fertilidad seminal y taza de preñes en un hato de ovinos katahdin mediante inseminación laparoscópica con semen refrigerado y congelado en ambiente tropical, fueron utilizados el reproductor y veinte vientres de la raza katahdin. Se realizaron dos evaluaciones para valorar la calidad del semen de acuerdo con sus características macroscópicas y microscópicas y las hembras fueron sincronizadas con dispositivos intravaginales con 0.3 g de progesterona natural (CIDR®, Zoetis), más una dosis de 400 UI de gonadotropina coriónica humana (GCH). La fertilidad fue mayor (p< 0,05) (30% de preñez) en borregas inseminadas con semen congelado, comparada al 20% de preñez en las inseminadas con semen frío. Las variables de fertilidad seminal evaluadas demostraron que el semen en el semental katahdin en ambiente tropical fue de buena calidad para su manipulación en la práctica de la inseminación artificial. El grupo racial de los animales utilizados respondieron satisfactoriamente a la sincronización y el semen estuvo dentro de los parámetros establecidos para la especie además toleró la manipulación, en cuanto a la inseminación por laparoscopía, es una técnica de cruzamiento poco diseminada en la región, sin embargo, el estudio desarrollado sugiere mayor investigación para aportar conocimientos suficientes para fortalecer el procedimiento y con ello incrementar la concepción en ovejas servidasThe objective of the study was to compare the semen fertility and pregnancy rate in a katahdin sheep herd by laparoscopic insemination with refrigerated and frozen semen in a tropical environment. The breeder and twenty bellies of the katahdin breed were used. Two evaluations were performed to assess the quality of the semen according to its macroscopic and microscopic characteristics and the females were synchronized with intravaginal devices with 0.3 g of natural progesterone (CIDR®, Zoetis), plus a dose of 400 IU of human chorionic gonadotropin (HCG). Fertility was higher (p< 0.05) (30% pregnancy) in ewes inseminated with frozen semen, compared to 20% pregnancy in those inseminated with cold semen. The evaluated seminal fertility variables demonstrated that the semen in katahdin stallions in a tropical environment is of good quality for handling in the practice of artificial insemination. It is concluded that the breed group of the animals used responded satisfactorily to the synchronization and the semen was within the parameters established for the species, it also tolerated the manipulation, in terms of insemination by laparoscopy, it is a crossbreeding technique that is not widely disseminated in the region however, the study developed suggests further research to provide sufficient knowledge to strengthen the procedure and thereby increase conception in ewes bred.O objetivo do estudo foi comparar a fertilidade seminal e a taxa de prenhez em um rebanho de ovelhas katahdin por meio de inseminação laparoscópica com sêmen refrigerado e congelado em ambiente tropical, foram utilizados o reprodutor e vinte úteros da raça katahdin. Foram realizadas duas avaliações para avaliar a qualidade do sêmen de acordo com suas características macroscópicas e microscópicas, e as fêmeas foram sincronizadas com dispositivos intravaginais com 0,3 g de progesterona natural (CIDR®, Zoetis), mais uma dose de 400 UI de gonadotrofina coriônica humana (HCG) . A fertilidade foi maior (p< 0,05) (30% de prenhez) em ovelhas inseminadas com sêmen congelado, em comparação com 20% de prenhez naquelas inseminadas com sêmen frio. As variáveis ​​de fertilidade seminal avaliadas demonstraram que o sêmen do garanhão katahdin em ambiente tropical era de boa qualidade para sua manipulação na prática da inseminação artificial. O grupo racial dos animais utilizados respondeu satisfatoriamente à sincronização e o sêmen estava dentro dos parâmetros estabelecidos para a espécie, também tolerou a manipulação, no que diz respeito à inseminação por laparoscopia, é uma técnica de cruzamento pouco difundida na região, porém , o estudo desenvolvido sugere novas pesquisas para fornecer conhecimento suficiente para fortalecer o procedimento e, assim, aumentar a concepção em ovelhas criadas

Territorios sustentables en contexto de pandemia

La obra ofrece trabajos que brindan un conocimiento científico sobre el impacto de la pandemia en la salud, la economía, el ambiente y los territorios y se plantean desafíos para hacer más sostenible la vida en las ciudades y en el campo para insertarse y poder competir a nivel global