2,242 research outputs found
Patterns of positive selection on the transcriptome of western Iberian Squalius fish: a new approach accounting for alternative splicing
Tese de mestrado, Biologia Evolutiva e do Desenvolvimento, Universidade de Lisboa, Faculdade de Ciências, 2019One of the main goals of evolutionary biology is to understand the molecular mechanisms of adaptation. Advances on next generation sequencing (NGS) have allowed to improve our knowledge on the mechanisms of adaptation, including in non-model organisms. One example is the use of RNA-seq data to test at the transcriptome level for the presence of signatures of positive selection using the ratio of non-synonymous to synonymous mutations (dN/dS ratio). However, the identification of orthologous sequences between the transcriptomes of different species is challenging because of the possibility of mixing different splicing isoforms on the ortholog alignments. Even so, by providing tens of thousands of sequences for protein coding genes, RNA-seq can be a powerful tool for understanding the time and mode of the adaptative process. In Portugal, the western Iberian freshwater cyprinids of the Squalius genus are a good system to study adaptation. The reason is that there are four species (S. carolitertii, S. pyrenaicus, S. torgalensis and S. aradensis) distributed across a north-south temperature cline, encompassing two distinct climate types – Atlantic and Mediterranean. Recent studies found evidences of adaptation to temperature in one of the southern species (S. torgalensis). In this study, we compared the transcriptomes of these four species to look for genes with signatures of positive selection, infer branches of their phylogeny with evidence for positive selection, and identify biological functions that were enriched in genes under positive selection. We also characterized the relationship between these species at the transcriptome level. Since our RNA-seq data for the different species came from different organs our study was especially vulnerable to the effect of alternative splicing. We have thus developed a new approach to deal with alternative splicing in comparative studies using transcriptomic data. Our approach was based on identifying ortholog alignments with different splicing isoforms and remove the regions on the alignments with exons that were not common between isoforms. Our results suggest that our approach manages to reduce the quantity of false positives related to alternative splicing in comparison with a more conventional approach. Regarding the phylogenetic relationship between species, we found support for the paraphyly between S. pyrenaicus and S. carolitertii, which has been also suggested by recent studies. Regarding the patterns of positive selection on these species, we found positive selection in 1.4% to 2.0% of the identified ortholog gene groups, which is comparable to what has been estimated for bony fish species in other studies. Interestingly, we found a relatively higher number of genes under positive selection on the branches of the southern species under the Mediterranean climate type than on the northern species under the Atlantic climate type. This could suggest that the southern Squalius species might be under stronger selective pressures due to the characteristics of the Mediterranean climate type, like high summer temperatures. We also found that the genes with signatures of selection were enriched on several biological functions, including blood coagulation, immunity, proteolysis, development and metabolism. Rather than having particular functions associated with specific branches of the phylogeny, most of the biological functions were generic and distributed similarly across species. This suggests that these biological functions have been consistently selected on the phylogeny. In conclusion, in this study we present a new approach to deal with alternative splicing on comparative studies using transcriptomic data, which can be useful for comparative studies on other species. We also present new transcriptomic data for two species of western Iberian Squalius – S. aradensis and the Tagus population of S. pyrenaicus. These results can be used as a resource for further studies on adaptation using the western Iberian Squalius as a model
Inocuidad Alimentaria
El curso contiene información general sobre los alimentos El curso contiene información general sobre los alimentos y su importancia en la alimentación humana, la cadena alimentaria y el mercado nacional e internacional de los alimentos : observa los fundamentos legales y técnicos de los alimentos de origen animal, su producción , procesamiento y comercialización destinados a la alimentación humana. Observando los diferentes métodos empleados para la obtención, conservación y gestión de la calidad de los productos y subproductos pecuarios, abarcando a toda la cadena alimentaria, en la cadena productiva y la red de valor y su importancia en el sistema de producción y el mercado de los alimentos ; dentro de un marco de referencia del control sistemático, integral y racional, basado en las Buenas Prácticas de Producción (BPP), Buenas Prácticas de Manufactura (BPM) y Procedimientos de Operación Estándar Sanitarios (POES) el concepto de Análisis de Peligros e Identificación de Puntos CrÃticos de Control ( HACCP ),manuales de operación, Flujograma de proceso y otros instrumentos de gestión de la calidad; asà como de la legislación sanitaria mexicana que se debe cumplir. Todo lo anterior destinado a la gestión y mejora continua de la calidad e inocuidad del producto y disminuir los peligros a la salud humana
Industrialización de Productos y Subproductos de Origen Animal
La Unidad de Aprendizaje comprende los fundamentos y caracterÃsticas de los diferentes métodos empleados para la transformación y conservación de los productos y subproductos pecuarios; dentro de un marco de referencia del control sistemático, integral y racional, basado en el concepto de aseguramiento de la calidad: Análisis de Peligros e Identificación de Puntos CrÃticos de Control ( HACCP ), manuales de operación, diagramas de bloques y de análisis de operaciones, bitácoras y otros instrumentos; asà como en la legislación sanitaria y zoosanitaria mexicana que se debe cumplir. El discente conocerá los principios fisicoquÃmicos, biológicos e industriales de los procesos de transformación. Todo lo anterior con el propósito de preservar la salud humana y animal
Propriedades psicométricas de uma escala para medir a gestão da vergonha em adolescentes (Moss-Sast)
(Ahmed, 1999) to measure shame management in adolescents in situations of aggression toward peers. The study was
conducted with a sample of 700 students from public secondary schools (N= 700) located in a northwestern state municipality
of Mexico. Results enabled to obtain an empirically sustainable measuring model formed by two factors: Acknowledgment
and Displacement (X2 = 5.16, p= 0.27; CMIN= 1.29; GFI= .98; CFI= .99; NFI= .97; RMSEA= .05). Evidence was obtained
to show that the instrument has criterion validity since it is capable to differentiate between subgroups of students with and
without reports of bullying in both factors, Acknowledgment (t= 3.49, gl= 137, p< .001) and Displacement (t= 3.63, gl= 137,
p< .001). It was concluded that the results strengthen the original factorial structure of the scale and show the usefulness of
the same, both for inquiring about emotions related to moral development and for identifying students involved as aggressors
in bullying situations.Se establecieron las evidencias de validez y confiabilidad de la adaptación del cuestionario MOSS-SAST (Ahmed, 1999)
para medir el manejo de la vergüenza en adolescentes ante situaciones de agresión hacia los pares. El estudio se realizó en
una muestra de estudiantes de escuelas secundarias públicas (N= 700) ubicadas en un municipio de un estado del noroeste
de México. Los resultados permitieron obtener un modelo de medición empÃricamente sustentable formado por nueve Ãtems
agrupados en dos factores: Reconocimiento y Desplazamiento (c2 = 5.16, p= 0.27; CMIN= 1.29; GFI= .98; CFI= .99; NFI=
.97; RMSEA= .05). El instrumento cuenta con evidencias de validez de criterio, ya que establece la diferencia en los factores
de reconocimiento (t= 3.49, gl= 137, p< .001) y desplazamiento (t= 3.63, gl= 137, p< .001) en subgrupos de estudiantes con
y sin reportes de bullying. Se concluyó que los resultados fortalecen la estructura factorial original de la escala y muestran su
utilidad, tanto en la indagación de emociones relacionadas con el del desarrollo moral, como en la identificación de estudiantes
involucrados como agresores en situaciones de bullying.Foram estabelecidas as evidências de validade e confiabilidade da adaptação do Questionário MOSS-SAST (Ahmed, 1999)
para medir a gestão da vergonha em adolescentes ante situações de agressão contra os pares. O estudo foi realizado com
uma amostra de estudantes do ensino fundamental e médio (N=700) de um municÃpio do noroeste do México. Os resultados
permitiram obter um modelo de medição empiricamente sustentável, formado por nove itens agrupados em dois fatores:
reconhecimento e deslocamento (c2 = 5.16, p= 0.27; CMIN= 1.29; GFI= .98; CFI= .99; NFI= .97; RMSEA= .05). O instrumento
conta com evidências de validade de critério já que estabelece a diferença nos fatores de reconhecimento (t= 3.49, gl= 137,
p< .001) e deslocamento (t= 3.63, gl= 137, p< .001) em subgrupos de estudantes com e sem relatos de bullying. Conclui-se
que os resultados fortalecem a estrutura fatorial original da escala e mostram sua utilidade, tanto na indagação de emoções
relacionadas com o desenvolvimento moral quanto na identificação de estudantes envolvidos como agressores em situações
de bullying
Restauración de un banco didáctico para la enseñanza de los motores de combustión interna a gasolina
En el Laboratorio De Motores de la Universidad Tecnológica de Pereira, se encuentra un motor de Simca 1000 centÃmetros cúbicos seccionado por la Escuela de TecnologÃa Mecánica como parte de un trabajo de curso. La calidad de dicho trabajo lo posiciona como una herramienta muy importante para la difusión del conocimiento y entendimiento del funcionamiento del motor de combustión interna a gasolina.
Sin embargo, ese material didáctico que facilita el estudio del motor se encontró deteriorado, sus mecanismos atascados, y con una funcionalidad limitada por el uso en el transcurso de los años. En ese estado se dificulta la explicación del funcionamiento de los mecanismos y sistemas por parte de los profesores y se dificulta su entendimiento. Además, el motor posee una tecnologÃa que para el dÃa de hoy es obsoleta; debido a esto se busca devolver el funcionamiento e implementar, en lo posible, un sistema de inyección didáctico básico con el fin de facilitar un tipo de tecnologÃa que se usa en motores modernos y que ofrece ventajas en consumo de combustibles, en potencia entregada, y reducen la contaminación ambiental y la polución
Eficacia del uso de la terapia combinada nifedipino/progesterona frente a nifedipino en el tiempo de prolongación del embarazo en gestantes con amenaza e parto pretérmino. hospital regional docente 2010-2014.
Comparar si la terapia combinada nifedipino/progesterona es más eficaz que
nifedipino para prolongar el embarazo en gestantes con amenaza de parto pretérmino,
teniendo las siguientes combinaciones, nifedipino + progesterona y nifedipino solo.
MATERIAL Y MÉTODO: Se realizó un estudio retrospectivo, transversal, comparativo y
observacional que evaluó 62 pacientes con diagnóstico de amenaza de parto pretérmino.
RESULTADOS: En el grupo de gestantes que se le administró el nifedipino solo, el
embarazo tuvo un tiempo promedio de prolongación de 6.96 dÃas y una desviación estándar de 5.83 dÃas, mientras que en el grupo de gestantes sometidos a la terapia con
nifedipino mas progesterona, el tiempo de prolongación del embarazo fue de 12.16 dÃas y
una desviación estándar de 11.67 dÃas presentando una diferencia estadÃstica significativa
(p< 0,05), y que permite señalar que la administración de la terapia combinada prolonga
por más dÃas el embarazo, respecto a la terapia no combinada; sin embargo, se tiene un
9.7% de partos no prematuros en el grupo con terapia combinada respecto al 0.0% de
partos no prematuros en el grupo con terapia no combinada, y al aplicar la prueba X
encuentra concordancias (p> 0,05), es decir no existe una diferencia estadÃsticamente
significativa en el tiempo de prolongación de la edad gestacional que interfiera con el
resultado del parto pretérmino; finalmente, la prueba F del análisis de covarianza no
detecta una diferencia estadÃsticamente significativa (p> 0,05) del tiempo de resolución de
la dinámica uterina, aunque se aprecia un menor tiempo promedio en las pacientes
sometidas a nifedipino, con (2.10dÃas), respecto a las pacientes sometidas a
nifedipino/progesterona (2.68 dÃas).
CONCLUSIONES: Se distingue una diferencia sustantiva en cuanto al tiempo de
prolongación del embarazo que es corroborada con la aplicación de la prueba F del análisis
de covarianza con un p< 0,05 con un promedio de 6,96 dÃas con nifedipino y de 12,16 dÃas
con aplicación de terapia combinada.Check whether combination therapy nifedipine / progesterone is more
effective than nifedipine to prolong pregnancy in pregnant women with preterm labor, with
the following combinations, nifedipine + progesterone and nifedipine alone.
MATERIAL AND METHODS: A retrospective, cross-sectional, comparative and
observational study that evaluated 62 patients with a diagnosis of preterm labor was
performed.
RESULTS: In the group of pregnant women who were administered the nifedipine alone
had an average pregnancy prolongation time 6.96 days and a standard deviation of 5.83
days, while in the group of pregnant women undergoing therapy with nifedipine plus
progesterone, time prolongation of pregnancy was 12.16 days and a standard deviation of
11.67 days showing a statistically significant difference ( p < 0.05 ) , and to point out that
the administration of combination therapy lasts more days pregnancy, compared to no
combined therapy ; however, it has a 9.7 % preterm births not in the combined-therapy
group compared to 0.0 % of preterm births not in the group with no combination therapy,
and applying the X2
test matches is not found ( p> 0.05 ) , there is no statistically
significant difference in injury time of gestational age that interferes with the outcome of
preterm delivery; finally the F-test analysis of covariance did not detect a statistically
significant difference ( p> 0.05 ) time resolution of the uterine dynamics , although shown a
lower average time patients undergoing nifedipine , with ( 2.10dÃas ) with regard to patients
undergoing nifedipine / progesterone ( 2.68 days).
10
CONCLUSIONS: Representative substantive difference in the time of pregnancy
prolongation which is corroborated by the application of the F-test analysis of covariance
with p < 0.05 with an average of 6.96 days and 12.16 days nifedipine with application of
combination therapy.Tesi
Improved predictions of the geographic distribution of invasive plants using climatic niche models
"Climatic niche models for invasive plants are usually constructed with occurrence records taken from literature and collections. Because these data neither discriminate among life-cycle stages of plants (adult or juvenile) nor the origin of individuals (naturally established or man-planted), the resulting models may mispredict the distribution ranges of these species. We propose that more accurate predictions could be obtained by modelling climatic niches with data of naturally established individuals, particularly with occurrence records of juvenile plants because this would restrict the predictions of models to those sites where climatic conditions allow the recruitment of the species. To test this proposal, we focused on the Peruvian peppertree (Schinus molle), a South American species that has largely invaded Mexico. Three climatic niche models were constructed for this species using high-resolution dataset gathered in the field. The first model included all occurrence records, irrespective of the life-cycle stage or origin of peppertrees (generalized niche model). The second model only included occurrence records of naturally established mature individuals (adult niche model), while the third model was constructed with occurrence records of naturally established juvenile plants (regeneration niche model). When models were compared, the generalized climatic niche model predicted the presence of peppertrees in sites located farther beyond the climatic thresholds that naturally established individuals can tolerate, suggesting that human activities influence the distribution of this invasive species. The adult and regeneration climatic niche models concurred in their predictions about the distribution of peppertrees, suggesting that naturally established adult trees only occur in sites where climatic conditions allow the recruitment of juvenile stages. These results support the proposal that climatic niches of invasive plants should be modelled with data of naturally established individuals because this improves the accuracy of predictions about their distribution ranges.
Evaluación de la oferta del recurso hÃdrico en la cuenca del rÃo Calandaima
Trabajo de investigaciónEl trabajo investigación realizado evalúa la oferta del recurso hÃdrico en la cuenca del rÃo Calandaima a partir del análisis de la información hidrológica obtenida de las diferentes entidades oficiales que tienen presencia en la zona de estudio, con base en esto, se establece la tendencia de la disponibilidad del recurso hÃdrico en la región y se genera una propuesta de ordenamiento del suelo que ayuda a la sostenibilidad del recurso hÃdrico y combatir su escasez.EspecializaciónEspecialista en Recursos HÃdrico
- …