The Distribution of Alpha Elements in Ultra-Faint Dwarf Galaxies

The Milky Way ultra-faint dwarf galaxies (UFDs) contain some of the oldest, most metal-poor stars in the Universe. We present [Mg/Fe], [Si/Fe], [Ca/Fe], [Ti/Fe], and mean [alpha/Fe], abundance ratios for 61 individual red giant branch stars across 8 UFDs. This is the largest sample of alpha abundances published to date in galaxies with absolute magnitudes M_V > -8, including the first measurements for Segue 1, Canes Venatici II, Ursa Major I, and Leo T. Abundances were determined via medium-resolution Keck/DEIMOS spectroscopy and spectral synthesis. The sample spans the metallicity range -3.4 < [Fe/H] < -1.1. With the possible exception of Segue 1 and Ursa Major II, the individual UFDs show on average lower [alpha/Fe] at higher metallicities, consistent with enrichment from Type Ia supernovae. Thus even the faintest galaxies have undergone at least a limited level of chemical self-enrichment. Together with recent photometric studies, this suggests that star formation in the UFDs was not a single burst, but instead lasted at least as much as the minimum time delay of the onset of Type Ia supernovae (~100 Myr) and less than ~2 Gyr. We further show that the combined population of UFDs has an [alpha/Fe] abundance pattern that is inconsistent with a flat, Galactic halo-like alpha abundance trend, and is also qualitatively different from that of the more luminous CVn I dSph, which does show a hint of a plateau at very low [Fe/H].Comment: 14 pages, 6 figures, re-submitted to ApJ with revisions based on referee repor

Globalización

El módulo elegido para la realización de este trabajo es economía y sociedad. A lo largo de este informe vamos a hablar de la globalización y de cómo esta afectó al Estado-Nación en Argentina y Chile, y por supuesto hablaremos de la integración. ¿Qué es la globalización? ¿Cómo afecta a los distintos campos, económico, político y cultural? ¿Cómo han sido afectados los Estados argentino y chileno por la globalización? ¿Podría intentarse una vía de superación de la globalización a través de la integración?. ¿Puede servir la integración como una vía alternativa a la globalización?. Nuestro objetivo es poder responder a las preguntas anteriores a lo largo de nuestro trabajo. Tratar de definir de un modo simple el concepto de globalización. Verificar como ha influido sobre nuestros países. Tratar de colocar a la integración como una vía posible para la resolución de nuestros problemas, pero no solo hablar de integración económica como el MERCOSUR, sino hablar de una integración cultural donde se resalten las identidades de cada pueblo, los valores y las costumbres

Aplicación de Amilasa para la reducción de Aceites y Grasas de los efluentes generados en el proceso de lavado de autos Comas - Lima, 2017

El objetivo principal de este trabajo ha sido orientado a plantear solución al vertimiento de aguas residuales sin tratamiento, dichas aguas residuales son provenientes de los servicios de lavado de vehículos, en el que se utilizan aproximadamente 225 m3 de agua al mes. Las características que presenta este efluente son concentraciones elevadas de hidrocarburos. En la presente investigación se busca el control del parámetro aceites y grasas mediante la aplicación de Amilasa, para el proceso inicial del tratamiento se realizó la selección de la muestra de manera intencional tomándose una muestra de 11 litros teniendo como una muestra de testigo durante todo el tiempo de tratamiento. Durante el tiempo de tratamiento se controlaron los parámetros de pH y temperatura durante la aplicación de la Amilasa en el efluente, así mismo se controló los aceites y grasas antes de la aplicación y después del tratamiento para verificar la tendencia en reducción del parámetro aceites y grasas en el efluente. El periodo de tratamiento duro 10 semanas, en el que se realizó la aplicación de Amilasa en las siguientes concentraciones 4 gr, 5 gr, 6 gr, 7 gr. La aplicación de estas concentraciones al agua residual fue evaluada con una muestra de control o testigo en todas las repeticiones realizadas. Los resultados de los análisis realizados en la degradación del parámetro de los aceites y grasas cuando se realizó la aplicación de 7 gr de Amilasa, obteniendo el mejor resultado de 563.15 mg/L de aceites y grasas reduciéndose hasta un 49% de reducción. Este resultado fue contrastado con la muestra testigo que se manejó en todos los muestreos realizados. Por lo tanto, los resultados obtenidos respondieron satisfactoriamente a la hipótesis planteada en la presente investigación La aplicación de Amilasa en condiciones normales permite la degradación del parámetro aceites y grasas de las aguas residuales del proceso de lavado de vehículo

Understanding the impact of NextGen in the airline industry

NextGen is the Federal Aviation Administration’s (FAA) current infrastructure program created with the purpose of modernizing the United States National Airspace System (NAS). It aims to make U.S. aviation more secure, effective, capable, predictable, and resilient by transforming its communications, navigation, and surveillance (FAA, 2022). The purpose of this paper will be outlined in three main points. First, we will discuss the importance of NextGen and convey the need for the new structure. Second, we will discuss the impacts of NextGen on the aviation industry in terms of navigation, communication, surveillance, resilience, airlines, the general public, and pilots. Last, we will provide recommendations and future research studies to improve upon Nextgen. This paper should be beneficial for those unaware of the capabilities of Nextgen and what it means for the future of pilots, airlines, and the general public. Demonstrating the use cases of Nextgen, this paper should also be valuable for airlines to better understand future needs and investment requirements and prepare accordingly

Recruitment of functionally distinct membrane proteins to chromatin mediates nuclear envelope formation in vivo

Formation of the nuclear envelope (NE) around segregated chromosomes occurs by the reshaping of the endoplasmic reticulum (ER), a reservoir for disassembled nuclear membrane components during mitosis. In this study, we show that inner nuclear membrane proteins such as lamin B receptor (LBR), MAN1, Lap2β, and the trans-membrane nucleoporins Ndc1 and POM121 drive the spreading of ER membranes into the emerging NE via their capacity to bind chromatin in a collaborative manner. Despite their redundant functions, decreasing the levels of any of these trans-membrane proteins by RNAi-mediated knockdown delayed NE formation, whereas increasing the levels of any of them had the opposite effect. Furthermore, acceleration of NE formation interferes with chromosome separation during mitosis, indicating that the time frame over which chromatin becomes membrane enclosed is physiologically relevant and regulated. These data suggest that functionally distinct classes of chromatin-interacting membrane proteins, which are present at nonsaturating levels, collaborate to rapidly reestablish the nuclear compartment at the end of mitosis

Development of Functional Microfold (M) Cells from Intestinal Stem Cells in Primary Human Enteroids.

Background &amp; aimsIntestinal microfold (M) cells are specialized epithelial cells that act as gatekeepers of luminal antigens in the intestinal tract. They play a critical role in the intestinal mucosal immune response through transport of viruses, bacteria and other particles and antigens across the epithelium to immune cells within Peyer's patch regions and other mucosal sites. Recent studies in mice have demonstrated that M cells are generated from Lgr5+ intestinal stem cells (ISCs), and that infection with Salmonella enterica serovar Typhimurium increases M cell formation. However, it is not known whether and how these findings apply to primary human small intestinal epithelium propagated in an in vitro setting.MethodsHuman intestinal crypts were grown as monolayers with growth factors and treated with recombinant RANKL, and assessed for mRNA transcripts, immunofluorescence and uptake of microparticles and S. Typhimurium.ResultsFunctional M cells were generated by short-term culture of freshly isolated human intestinal crypts in a dose- and time-dependent fashion. RANKL stimulation of the monolayer cultures caused dramatic induction of the M cell-specific markers, SPIB, and Glycoprotein-2 (GP2) in a process primed by canonical WNT signaling. Confocal microscopy demonstrated a pseudopod phenotype of GP2-positive M cells that preferentially take up microparticles. Furthermore, infection of the M cell-enriched cultures with the M cell-tropic enteric pathogen, S. Typhimurium, led to preferential association of the bacteria with M cells, particularly at lower inoculum sizes. Larger inocula caused rapid induction of M cells.ConclusionsHuman intestinal crypts containing ISCs can be cultured and differentiate into an epithelial layer with functional M cells with characteristic morphological and functional properties. This study is the first to demonstrate that M cells can be induced to form from primary human intestinal epithelium, and that S. Typhimurium preferentially infect these cells in an in vitro setting. We anticipate that this model can be used to generate large numbers of M cells for further functional studies of these key cells of intestinal immune induction and their impact on controlling enteric pathogens and the intestinal microbiome

Plant Hormone Addition on Mutant Millets

In this experiment we tested the effects of adding plant hormones to dwarf mutant millet plants that were either non-responsive to this hormone or did not make the hormone naturally. Measurements were taken on a consistent basis to determine how much growth had been affected by the addition of the plant hormone gibberellins, as well as the growth on our control plants that did not receive this hormone addition. Based on prior research, this hormone as said above is crucial in stem elongation and primary growth of plants. The results of this experiment will help to determine which type of dwarf mutant each plant group is, since changes in growth will provide evidence as to whether the plants respond to hormone treatments or not

From the Anthropocene to mutual thriving: An Agenda for higher education in the Ecozoic

Higher education in the global North, and exported elsewhere, is complicit in driving the planet\u27s socio-ecological crises by teaching how to most effectively marginalize and plunder Earth and human communities. As students and activists within the academic system, we take a firm stand to arrest this cycle, and to redirect education toward teaching how to create conditions for all life to thrive. In this paper, we articulate a research and education agenda for co-constructing knowledge and wisdom, and propose shifts in the \u27ologies from the current, destructive modes to intended regenerative counterparts. We offer to shift from an ontology of separation to that of interconnectedness; from an epistemology of domination to that of egalitarian relationship; and from an axiology of development to that of plural values for world- and meaning-making. Such paradigm shifts reflect the foundational aspirations of the consilient transdiscipline of ecological economics. We analyze several introductory university textbooks in economics, law, and natural sciences, to demonstrate how destructive \u27ologies are taught in North American universities, and how such teaching implicitly undermines critical inquiry and effective challenge. Our strategy for change is to provide a new theoretical framework for education: the regenerative \u27ologies of the Ecozoic\u27, based on biophysicality, embedded relationality, pluralism, and the sustainable well-being of all members in the community of life