3,104 research outputs found
Genetic Variation in Human Gene Regulatory Factors Uncovers Regulatory Roles in Local Adaptation and Disease
Differences in gene regulation have been suggested to play essential roles in the evolution of phenotypic changes. Although DNA changes in cis-regulatory elements affect only the regulation of its corresponding gene, variations in gene regulatory factors (trans) can have a broader effect, because the expression of many target genes might be affected. Aiming to better understand how natural selection may have shaped the diversity of gene regulatory factors in human, we assembled a catalog of all proteins involved in controlling gene expression. We found that at least five DNA-binding transcription factor classes are enriched among genes located in candidate regions for selection, suggesting that they might be relevant for understanding regulatory mechanisms involved in human local adaptation. The class of KRAB-ZNFs, zinc-finger (ZNF) genes with a Krüppel-associated box, stands out by first, having the most genes located on candidate regions for positive selection. Second, displaying most nonsynonymous single nucleotide polymorphisms (SNPs) with high genetic differentiation between populations within these regions. Third, having 27 KRAB-ZNF gene clusters with high extended haplotype homozygosity. Our further characterization of nonsynonymous SNPs in ZNF genes located within candidate regions for selection, suggests regulatory modifications that might influence the expression of target genes at population level. Our detailed investigation of three candidate regions revealed possible explanations for how SNPs may influence the prevalence of schizophrenia, eye development, and fertility in humans, among other phenotypes. The genetic variation we characterized here may be responsible for subtle to rough regulatory changes that could be important for understanding human adaptation
Bosques: Recursos y Manejo Sustentable
La primera parte del curso presenta conceptos técnicos sobre los bosques, su
distribución y ecología. La unidad de estudio incluye los bosques Andinos y de
las estribaciones occidentales y orientales. Se revisará los principios para
el manejo de los bosques, diferenciando el manejo para la conservación del
manejo productivo de los bosques. Además se revisará y discutirá la forma de
evaluar los bosques a nivel nacional como internacional. Para ello, se
diferenciará entre los conceptos de calidad y de la biodiversidad de los
bosques y como éstos se aplican al monitoreo de los bosques. La segunda parte
del curso analiza las formas de manejo de bosque característico para los
bosques de Latinoamérica, desde el manejo comunal hasta el manejo privado de
los mismos. Se revisará en este contexto las categorías nacionales peruanas de
Áreas Naturales Protegidas por el Estado y la categoría internacional de
Reserva de la Biosfera
Y Seguimos Volando
Senior Project submitted to The Division of Languages and Literature of Bard College
Impact of a strong Saharan dust outbreak in the Caribbean
Treballs Finals de Grau de Física, Facultat de Física, Universitat de Barcelona, Curs: 2016, Tutora: Yolanda Sola SalvatierraIn June 2020, a dust storm crossed the Atlantic, from Africa to the Caribbean, within a few days, becoming one of the greatest dust events in the last two decades. A second dust plume, albeit less intense, was observed on 26-28 June. High and low values of aerosol optical depth and Angstrom exponent, respectively, were recorded from 21 June to 23 June in the Caribbean. On 22 June aerosol optical depth peaked at 1.9 in Guadeloupe. An isentropic layer was observed in dusty days, bounding the dust over the isles. A strong dust uplift over Africa, the subsequent accumulation on the West African coast and high-altitude winds led to large amounts of dust transport
The damaging and protective features of eosinophils in healthy individuals and patients with chronic inflammatory respiratory diseases
The Variable Expression of Transitive Subject and Possesor in Wayuunaiki (Guajiro)
In Wayuunaiki, verbal affixes cross-reference clausal arguments in various ways. Most notably, there are two ways to express transitive subjects, and two ways to express possessors. Much like voice alternatives, the variable expression of subject and possessor impart different perspectives on a situation type, but unlike traditional voice categories, syntactic valence remains equal. This dissertation characterizes these constructions with a specific question in mind: what do these two cross-referencing alternations communicate and what influences their usage? To answer these questions, I consider the linguistic properties observed in the usage of these constructions in narratives (Jusayú 1986, 1994), and informal conversations.
Mosonyi (1975) describes the Subjective and Objective transitive clauses as focus alternatives. Álvarez (1993) discovered that the O in the Objective clause must be definite. Despite the association of definiteness and focus as a central factors, the usage of the alternatives in discourse has has not received enough attention. I here conclude that the Subjective variant is the pragmatically marked option, whose primary function is to defocus a 3rd person O that is typically inanimate, new and non-topical. This clause type has the effect of retaining its syntactic valency, but expresseing semantically low transitivity.
Álvarez (1990) documents possessor ascension as a construction that involves unrestricted noun incorporation. Matera (2001) adds that the possessor of an incorporated noun can only assume the role of transitive object or stative subject. In the present corpus exploration, I conclude that the External Possessor construction is the functionally marked clause, whose function is primarily to defocus a possessed nominal that is typically inalienable, inanimate, and non-topical information. Additionally, whole-part relationships frequently participate in incorporation, while kinship relations do so rarely.
These two ways to cross-reference arguments are here interpreted as differential focus assignment on clausal arguments (Dixon & Aikhenvald 1997). They both involve the prefixation of a- referring to the transitive subject and the external possessor. I conclude that in these constructions this prefix has the effect of backgrounding an entity and consequently assigning undivided focus to the subject or the possessor
Unraveling molecular signaling in neurodegenerative diseases:focus on a protective mechanism mediated by linalool
Neurodegenerative conditions such as Alzheimer`s disease (AD) and stroke are characterized by progressive nervous system dysfunction. The main aim of this work was to propose new therapeutic targets in neurodegeneration and to identify possible phospholipid biomarkers that reflect the progression of the disease. We demonstrated that administration of the terpene, linalool was able to reduce the main pathological markers of AD (extracellular β-amyloidosis, tauopathy) and of ischemic stroke. Linalool treatment in animals improved motor coordination and cognition, along with a reduction of astrogliosis and microgliosis in the hippocampus. Besides, we investigated whether and how linalool exert a neuroprotective effect against glutamate-induced oxidative stress and might affect mitochondrial function. Administration of linalool reduced cell death mediated by glutamate, mitochondrial ROS formation, mitochondrial calcium uptake, lipid peroxidation and mediated a recovery of mitochondrial membrane potential, together with an increase in mitochondrial respiration. In addition, we detected remarkable changes in phospholipids in ischemic stroke, AD and CADASIL in brain samples, CSF and serum. These data could help to unravel novel molecular mechanisms and propose different therapeutic targets to treat transversal pathogenesis. Finally, we showed in a review the role of microglia in neurodegenerative diseases and we present the results of a differentiation protocol of human microglia from iPSC demonstrating the maturity and functionality of these cells. In conclusion, we present various strategies to model and study neurodegeneration and provide answers in the field of inflammation, lipidomics and at the same time we propose a new molecule as a potential therapy against AD and cerebral ischemia
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