784 resultados para Ancestral
Resumo:
Lucía Piossek Prebisch es una filósofa argentina con una importante trayectoria en la docencia y en la investigación. Egresó de Filosofía de la Facultad de Filosofía y Letras de la Universidad Nacional de Tucumán (UNT), y es profesora emérita por la misma casa de estudios. Allí se desempeñó en los cargos máximos de la docencia en la asignatura Filosofía Contemporánea, y dictó también Filosofía en la Argentina y Filosofía de la Historia. Asimismo, fue fundadora y directora del Instituto de Historia y Pensamiento Argentinos, entre otras actividades académicas desarrolladas en esa misma institución. A principios de los años setenta, la revista Sur publica "La mujer y la filosofía",un ensayo donde Lucía Piossek Prebisch presenta su tesis fenomenológica acerca de la experiencia de la maternidad. La autora sostiene que "la filosofía ha estado consustanciada de modo ancestral con lo masculino", dando un giro al tratamiento que el filósofo existencialista cristiano Gabriel Marcel realiza de la "experiencia de la paternidad". Indagó acerca de la "corporalidad", la "libertad" y la "situación" de las mujeres, más específicamente durante la gestación y la lactancia. En ese ensayo hallamos no solo una recepción del existencialismo, sobre todo en sus primeros contactos con el ámbito intelectual argentino, sino además los "ecos" de su perspectiva de análisis, ligada a la filósofa Simone de Beauvoir -de cuya posición sobre la maternidad se aleja- y su relación con las poetas Alfonsina Storni y Gabriela Mistral. Asimismo, en su obra se detecta la influencia de la escritora Virginia Woolf y de figuras poco transitadas en nuestro medios, como la filósofa religiosa Edith Stein (1891-1942) y la ensayista española María Zambrano (1904-1991), entre otras. En ese ensayo, Lucía Piossek Prebisch realiza un tratamiento original en su época acerca de la experiencia de la maternidad: el cuerpo propio de la mujer es, al mismo tiempo, el cuerpo de "otro", el ser en gestación sobre cuyo desarrollo dentro de sí no tiene decisión ni competencia: "... el cuerpo durante la gestación y la lactancia, se experimenta como donación de sí y no solo como medio para los fines de la especie" (Piossek Prebisch, 1973: 101). A sus casi ochenta y siete años, Lucía Piossek Prebisch nos recibió, en abril del 2012, en su casa del barrio Yerba Buena de San Miguel de Tucumán y -rodeada de cuadros que muestran un reverdecer tucumano-, nos cuenta sobre el contexto de producción de su ensayo "La mujer y la filosofía", que fue presentado en las Segundas Jornadas de Filosofía, organizadas por la Asociación Argentina de Filosofía, en noviembre de 1965, en la ciudad de La Plata, cuyas Actas publicó la editorial Sudamericana en la colección "Perspectiva" en el año 1966
Resumo:
Frente al éxito de algunos productos andinos como la quinua, la papa o la maca en el comercio agroalimentario internacional y ante la creciente degradación ambiental que afrontan los países en desarrollo producto de actividades de explotación intensiva; nuestra investigación busca evidenciar la tendencia que se asume desde la comunidad académica/científica y los funcionarios públicos del sector agroalimentario en el Perú, frente a la necesidad de mantener sostenible diversos modos ancestrales de producción agrícola (caso quinua), para ello analizamos información cuantitativa y cualitativa obtenida de las instituciones públicas y las universidades peruanas.
Resumo:
Lucía Piossek Prebisch es una filósofa argentina con una importante trayectoria en la docencia y en la investigación. Egresó de Filosofía de la Facultad de Filosofía y Letras de la Universidad Nacional de Tucumán (UNT), y es profesora emérita por la misma casa de estudios. Allí se desempeñó en los cargos máximos de la docencia en la asignatura Filosofía Contemporánea, y dictó también Filosofía en la Argentina y Filosofía de la Historia. Asimismo, fue fundadora y directora del Instituto de Historia y Pensamiento Argentinos, entre otras actividades académicas desarrolladas en esa misma institución. A principios de los años setenta, la revista Sur publica "La mujer y la filosofía",un ensayo donde Lucía Piossek Prebisch presenta su tesis fenomenológica acerca de la experiencia de la maternidad. La autora sostiene que "la filosofía ha estado consustanciada de modo ancestral con lo masculino", dando un giro al tratamiento que el filósofo existencialista cristiano Gabriel Marcel realiza de la "experiencia de la paternidad". Indagó acerca de la "corporalidad", la "libertad" y la "situación" de las mujeres, más específicamente durante la gestación y la lactancia. En ese ensayo hallamos no solo una recepción del existencialismo, sobre todo en sus primeros contactos con el ámbito intelectual argentino, sino además los "ecos" de su perspectiva de análisis, ligada a la filósofa Simone de Beauvoir -de cuya posición sobre la maternidad se aleja- y su relación con las poetas Alfonsina Storni y Gabriela Mistral. Asimismo, en su obra se detecta la influencia de la escritora Virginia Woolf y de figuras poco transitadas en nuestro medios, como la filósofa religiosa Edith Stein (1891-1942) y la ensayista española María Zambrano (1904-1991), entre otras. En ese ensayo, Lucía Piossek Prebisch realiza un tratamiento original en su época acerca de la experiencia de la maternidad: el cuerpo propio de la mujer es, al mismo tiempo, el cuerpo de "otro", el ser en gestación sobre cuyo desarrollo dentro de sí no tiene decisión ni competencia: "... el cuerpo durante la gestación y la lactancia, se experimenta como donación de sí y no solo como medio para los fines de la especie" (Piossek Prebisch, 1973: 101). A sus casi ochenta y siete años, Lucía Piossek Prebisch nos recibió, en abril del 2012, en su casa del barrio Yerba Buena de San Miguel de Tucumán y -rodeada de cuadros que muestran un reverdecer tucumano-, nos cuenta sobre el contexto de producción de su ensayo "La mujer y la filosofía", que fue presentado en las Segundas Jornadas de Filosofía, organizadas por la Asociación Argentina de Filosofía, en noviembre de 1965, en la ciudad de La Plata, cuyas Actas publicó la editorial Sudamericana en la colección "Perspectiva" en el año 1966
Resumo:
Frente al éxito de algunos productos andinos como la quinua, la papa o la maca en el comercio agroalimentario internacional y ante la creciente degradación ambiental que afrontan los países en desarrollo producto de actividades de explotación intensiva; nuestra investigación busca evidenciar la tendencia que se asume desde la comunidad académica/científica y los funcionarios públicos del sector agroalimentario en el Perú, frente a la necesidad de mantener sostenible diversos modos ancestrales de producción agrícola (caso quinua), para ello analizamos información cuantitativa y cualitativa obtenida de las instituciones públicas y las universidades peruanas.
Resumo:
Frente al éxito de algunos productos andinos como la quinua, la papa o la maca en el comercio agroalimentario internacional y ante la creciente degradación ambiental que afrontan los países en desarrollo producto de actividades de explotación intensiva; nuestra investigación busca evidenciar la tendencia que se asume desde la comunidad académica/científica y los funcionarios públicos del sector agroalimentario en el Perú, frente a la necesidad de mantener sostenible diversos modos ancestrales de producción agrícola (caso quinua), para ello analizamos información cuantitativa y cualitativa obtenida de las instituciones públicas y las universidades peruanas.
Resumo:
Routes of migration and exchange are important factors in the debate about how the Neolithic transition spread into Europe. Studying the genetic diversity of livestock can help in tracing back some of these past events. Notably, domestic goat (Capra hircus) did not have any wild progenitors (Capra aegagrus) in Europe before their arrival from the Near East. Studies of mitochondrial DNA have shown that the diversity in European domesticated goats is a subset of that in the wild, underlining the ancestral relationship between both populations. Additionally, an ancient DNA study on Neolithic goat remains has indicated that a high level of genetic diversity was already present early in the Neolithic in northwestern Mediterranean sites. We used coalescent simulations and approximate Bayesian computation, conditioned on patterns of modern and ancient mitochondrial DNA diversity in domesticated and wild goats, to test a series of simplified models of the goat domestication process. Specifically, we ask if domestic goats descend from populations that were distinct prior to domestication. Although the models we present require further analyses, preliminary results indicate that wild and domestic goats are more likely to descend from a single ancestral wild population that was managed 11,500 years before present, and that serial founding events characterise the spread of Capra hircus into Europe.
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Although ancestral polymorphisms and incomplete lineage sorting are commonly used at the population level, increasing reports of these models have been invoked and tested to explain deep radiations. Hypotheses are put forward for ancestral polymorphisms being the likely reason for paraphyletic taxa at the class level in the diatoms based on an ancient rapid radiation of the entire groups. Models for ancestral deep coalescence are invoked to explain paraphyly and molecular evolution at the class level in the diatoms. Other examples at more recent divergences are also documented. Discussion as to whether or not paraphyletic groups seen in the diatoms at all taxonomic levels should be recognized is provided. The continued use of the terms centric and pennate diatoms is substantiated with additional evidence produced to support their use in diatoms both as descriptive terms for both groups and as taxonomic groups for the latter because new morphological evidence from the auxospores justifies the formal classification of the basal and core araphids as new subclasses of pennate diatoms in the Class Bacillariophyceae. Keys for higher levels of the diatoms showing how the terms centrics and araphid diatoms can be defined are provided.
Resumo:
Although ancestral polymorphisms and incomplete lineage sorting are commonly used at the population level, increasing reports of these models have been invoked and tested to explain deep radiations. Hypotheses are put forward for ancestral polymorphisms being the likely reason for paraphyletic taxa at the class level in the diatoms based on an ancient rapid radiation of the entire groups. Models for ancestral deep coalescence are invoked to explain paraphyly and molecular evolution at the class level in the diatoms. Other examples at more recent divergences are also documented. Discussion as to whether or not paraphyletic groups seen in the diatoms at all taxonomic levels should be recognized is provided. The continued use of the terms centric and pennate diatoms is substantiated with additional evidence produced to support their use in diatoms both as descriptive terms for both groups and as taxonomic groups for the latter because new morphological evidence from the auxospores justifies the formal classification of the basal and core araphids as new subclasses of pennate diatoms in the Class Bacillariophyceae. Keys for higher levels of the diatoms showing how the terms centrics and araphid diatoms can be defined are provided.
Resumo:
Natural selection mediated by pollinators has influenced the evolution of floral diversity of the flowering plants (angiosperms). The scope of this thesis was to study: 1) phenotypic selection, 2) mating systems, and 3) floral shifts involved in plant speciation. Model plant species were Platanthera bifolia and P. chlorantha (Orchidaceae). These orchids are moth-pollinated, strictly co-sexual (bisexual flowers), and produce a spike that displays 10-20 white flowers. I explored the influence of characters on plant fitness by using multiple linear regressions. Pollen removal (male fitness) and fruit set (female fitness) increased with more flowers per plant in three P. bifolia populations. There was selection towards longer spurs in a dry year when average spur length was shorter than in normal-wet years. Female function was sensitive to drought, which enabled an application of the male function hypothesis of floral evolution (Bateman's principle). The results show that selection may vary between populations, years, and sex-functions. I examined inbreeding by estimating levels of geitonogamy (self-pollination between flowers of an individual) with an emasculation method in two P. bifolia populations. Geitonogamy did not vary with inflorescence size. Levels of geitonogamy was 20-40% in the smaller, but non-significant in the larger population. This may relate to lower number of possible mates and pollinator activity in the smaller population. Platanthera bifolia exhibits the ancestral character state of tongue-attachment of pollinia on the pollinator. Its close relative P. chlorantha attaches its pollinia onto the pollinator's eyes. To explore the mechanism of a floral shift, pollination efficiency and speed was compared between the two species. The results showed no differences in pollination efficiency, but P. chlorantha had faster pollen export and import. Efficiency of pollination in terms of speed may cause floral shifts, and thus speciation.
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We analyzed genome-wide association studies (GWASs), including data from 71,638 individuals from four ancestries, for estimated glomerular filtration rate (eGFR), a measure of kidney function used to define chronic kidney disease (CKD). We identified 20 loci attaining genome-wide-significant evidence of association (p < 5 × 10(-8)) with kidney function and highlighted that allelic effects on eGFR at lead SNPs are homogeneous across ancestries. We leveraged differences in the pattern of linkage disequilibrium between diverse populations to fine-map the 20 loci through construction of "credible sets" of variants driving eGFR association signals. Credible variants at the 20 eGFR loci were enriched for DNase I hypersensitivity sites (DHSs) in human kidney cells. DHS credible variants were expression quantitative trait loci for NFATC1 and RGS14 (at the SLC34A1 locus) in multiple tissues. Loss-of-function mutations in ancestral orthologs of both genes in Drosophila melanogaster were associated with altered sensitivity to salt stress. Renal mRNA expression of Nfatc1 and Rgs14 in a salt-sensitive mouse model was also reduced after exposure to a high-salt diet or induced CKD. Our study (1) demonstrates the utility of trans-ethnic fine mapping through integration of GWASs involving diverse populations with genomic annotation from relevant tissues to define molecular mechanisms by which association signals exert their effect and (2) suggests that salt sensitivity might be an important marker for biological processes that affect kidney function and CKD in humans.
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La berenjena (Solanum melongena L.) es una planta solanácea de múltiples variedades, cuyos ancestros salvajes se sitúan en Indochina y el este de África. Su cultivo fue muy temprano en zonas de China e India. Aun así, no se extendió al Occidente antiguo ni apenas se conoció, de ahí su ausencia en los textos clásicos de botánica y farmacología. Fueron los árabes quienes llevaron el cultivo de la planta por el Norte de África y Al-Andalus, de donde pasó ya a Europa. Los primeros testimonios occidentales de la berenjena aparecen en traducciones latinas de textos árabes, para incorporarse luego a la literatura farmacológica medieval y, más tarde ya, a la del Renacimiento, que empezó a tratar de ella por su posible parecido con una especie de mandrágora. Pese a que se le reconocían algunas virtudes medicinales, siempre se la tuvo bajo sospecha por ser de sabor poco agradable, indigesta y causante de algunas afecciones. Solo los botánicos de finales del Renacimiento describirían la planta y sus variedades con criterios más «científicos» y botánicos, ya sin apenas intereses farmacológicos.
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Thesis (Ph.D.)--University of Washington, 2016-07
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Known as one of North America’s natural treasures, the Loess Hills is also one of our country’s archaeological gems. This unique landscape harbors hundreds of well-preserved earth lodge dwellings and palisades villages built by ancestral Plains Indians. The descendants of these early Iowa farmers were first described in the journals and accounts of 18th- and 19th-century travelers and explorers. Celebrated artists, such as Karl Bodmer and George Catlin, forever fixed the vibrant life ways of these people in our mind’s eye. The historical legacy of the Loess Hills lies in a rich archaeological record.
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Eukaryotic genomes contain repetitive DNA sequences. This includes simple repeats and more complex transposable elements (TEs). Many TEs reach high copy numbers in the host genome, owing to their amplification abilities by specific mechanisms. There is growing evidence that TEs contribute to gene transcriptional regulation. However, excess of TE activity may lead to reduced genome stability. Therefore, TEs are suppressed by the transcriptional gene silencing machinery via specific chromatin modifications. In contrary, effectiveness of the epigenetic silencing mechanisms imposes risk for TE survival in the host genome. Therefore, TEs may have evolved specific strategies for bypassing epigenetic control and allowing the emergence of new TE copies. Recent studies suggested that the epigenetic silencing can be, at least transiently, attenuated by heat stress in A. thaliana. Heat stress induced strong transcriptional activation of COPIA78 family LTR-retrotransposons named ONSEN, and even their transposition in mutants deficient in siRNA-biogenesis. ONSEN transcriptional activation was facilitated by the presence of heat responsive elements (HREs) within the long terminal repeats, which serve as a binding platform for the HEAT SHOCK FACTORs (HSFs). This thesis focused on the evolution of ONSEN heat responsiveness in Brassicaceae. By using whole-transcriptome sequencing approach, multiple Arabidopsis lyrata ONSENs with conserved heat response were found and together with ONSENs from other Brassicaceae were used to reconstruct the evolution of ONSEN HREs. This indicated ancestral situation with two, in palindrome organized, HSF binding motifs. In the genera Arabidopsis and Ballantinia, a local duplication of this locus increased number of HSF binding motifs to four, forming a high-efficiency HRE. In addition, whole transcriptome analysis revealed novel heat-responsive TE families COPIA20, COPIA37 and HATE. Notably, HATE represents so far unknown COPIA family which occurs in several Brassicaceae species but is absent in A. thaliana. Putative HREs were identified within the LTRs of COPIA20, COPIA37 and HATE of A. lyrata, and could be preliminarily validated by transcriptional analysis upon heat induction in subsequent survey of Brassicaeae species. Subsequent phylogenetic analysis indicated a repeated evolution of heat responsiveness within Brassicaceae COPIA LTR-retrotransposons. This indicates that acquisition of heat responsiveness may represent a successful strategy for survival of TEs within the host genome.
Phylum-wide transcriptome analysis of oogenesis and early embryogenesis in selected nematode species
Resumo:
Oogenesis is a prerequisite for embryogenesis in Metazoa. During both biological processes important decisions must be made to form the embryo and hence ensure the next generation: (1) Maternal gene products (mRNAs, proteins and nutrients) must be supplied to the embryo. (2) Polarity must be established and axes must be specified. While incorporation of maternal gene products occurs during oogenesis, the time point of polarity establishment and axis specification varies among species, as it is accomplished either prior, during, or after fertilisation. But not only the time point when these events take place varies among species but also the underlying mechanisms by which they are triggered. For the nematode model Caenorhabditis elegans the underlying pathways and gene regulatory networks (GRNs) are well understood. It is known that there the sperm entry point initiates a primary polarity in the 1-celled egg and with it the establishment of the anteroposterior axis. However, studies of other nematodes demonstrated that polarity establishment can be independent of sperm entry (Goldstein et al., 1998; Lahl et al., 2006) and that cleavage patterns, symmetry formation and cell specification also differ from C. elegans. In contrast to the studied Chromadorea (more derived nematodes including C. elegans), embryos of some marine Enoplea (more basal representatives) even show no discernible early polarity and blastomeres can adopt variable cell fates (Voronov and Panchin 1998). The underlying pathways controlling the obviously variant embryonic processes in non-Caenorhabditis nematodes are essentially unknown. In this thesis I addressed this issue by performing a detailed unbiased comparative transcriptome analysis based on microarrays and RNA sequencing of selected developmental stages in a variety of nematodes from different phylogenetic branches with C. elegans as a reference system and a nematomorph as an outgroup representative. In addition, I made use of available genomic data to determine the presence or absence of genes for which no expression had been detected. In particular, I focussed on components of selected pathways or GRNs which are known to play essential roles during C. elegans development and/or other invertebrate or vertebrate model systems. Oogenesis must be regulated differently in non-Caenorhabditis nematodes, as crucial controlling components of Wnt and sex determination signaling are absent in these species. In this respect, I identified female-specific expression of potential polarity associated genes during gonad development and oogenesis in the Enoplean nematode Romanomermis culicivorax. I could show that known downstream components of the polarity complexes PAR-3/-6/PKC-3 and PAR-1/-2 are absent in non-Caenorhabditis species. Even PAR-2 as part of the polarity complex does not exist in these nematodes. Instead, transcriptomes of nematodes (including C. elegans), show expression of other polarity-associated complexes such as the Lgl (Lethal giant larvae) complex. This result could pose an alternative route for nematodes and nematomorphs to initiate polarity during early embryogenesis. I could show that crucial pathways of axis specification, such as Wnt and BMP are very different in C. elegans compared to other nematodes. In the former, Wnt signaling, for instance, is mediated by four paralogous beta-catenins, while other Chromadorea have fewer and Enoplea only one beta-catenin. The transcriptomes of R. culicivorax and the nematomorph show that regulators of BMP (e.g. Chordin), are specifically expressed during early embryogenesis only in Enoplea and the close outgroup of nematomorphs. In conclusion, my results demonstrate that the molecular machinery controlling oogenesis and embryogenesis in nematodes is unexpectedly variable and C. elegans cannot be taken as a general model for nematode development. Under this perspective, Enoplean nematodes show more similarities with outgroups than with C. elegans. It appears that certain pathway components were lost or gained during evolution and others adopted new functions. Based on my findings I can conjecture, which pathway components may be ancestral and which were newly acquired in the course of nematode evolution.