Assembly of the nucleolus: in need of revision

© 2015 The AuthorOur current view of the nucleolus has been shaped by the concept that the organization of this prominent compartment within the nucleus is primarily dictated by its function, the making of ribosome subunits. Whether ribosome biogenesis is framed by a dedicated nucleolar scaffold has remained unclear. In this issue of The EMBO Journal, Caudron‐Herger and colleagues present evidence for a nucleolar skeleton composed of non‐coding RNA enriched in Alu repeat elements.info:eu-repo/semantics/publishedVersio

RNA imaging: seeing is believing

© 2015 Carmo-Fonseca; Published by Cold Spring Harbor Laboratory Press for the RNA Society. This article, published in RNA, is available under a Creative Commons License (Attribution-NonCommercial 4.0 International), as described at http://creativecommons.org/licenses/by-nc/4.0/.Twenty years ago, in the middle 1990s, a pending debate in the RNA cell biology field concerned the nuclear organization of pre-mRNA splicing. Localization studies using antibodies to detect proteins of the spliceosome and oligonucleotide probes that hybridized with the spliceosomal small nuclear RNAs had revealed that practically all building blocks of the splicing machinery were not uniformly distributed in the nucleus but rather appeared concentrated in defined regions. These regions were termed “nuclear speckles” or “splicing domains” due to the local enrichment in splicing factors. Whether or not pre-mRNA splicing occurred within these domains remained controversial.info:eu-repo/semantics/publishedVersio

Splicing- and cleavage-independent requirement of RNA polymerase II CTD for mRNA release from the transcription site

Eukaryotic cells have a surveillance mechanism that identifies aberrantly processed pre-mRNAs and prevents their flow to the cytoplasm by tethering them near the site of transcription. Here we provide evidence that mRNA release from the transcription site requires the heptad repeat structure of the C-terminal domain (CTD) of RNA polymerase II. The mammalian CTD, which is essential for normal co-transcriptional maturation of mRNA precursors, comprises 52 heptad repeats. We show that a truncated CTD containing 31 repeats (heptads 1–23, 36–38, and 48–52) is sufficient to support transcription, splicing, cleavage, and polyadenylation. Yet, the resulting mRNAs are mostly retained in the vicinity of the gene after transcriptional shutoff. The retained mRNAs maintain the ability to recruit components of the exon junction complex and the nuclear exosome subunit Rrp6p, suggesting that binding of these proteins is not sufficient for RNA release. We propose that the missing heptads in the truncated CTD mutant are required for binding of proteins implicated in a final co-transcriptional maturation of spliced and 3′ end cleaved and polyadenylated mRNAs into export-competent ribonucleoprotein particles

Trayectoria de paradigmas que explican la fecundidad

El objetivo principal de este estudio es identificar la posible conexión entre la propuesta original de la teoría de la transición demográfica y otros paradigmas que explican los cambios en el comportamiento reproductivo de las poblaciones, aparecidos en la segunda mitad del siglo XX. Las principales conclusiones se refieren a las continuidades y rupturas en la trayectoria de las teorías escogidas en el estudio: transición de la fecundidad, teoría del costo beneficio de los hijos, modelo de los determinantes próximos de la fecundidad, teoría del flujo intergeneracional de riquezas y estudios de población con enfoque de género. Además, la discusión de los cambios entre paradigmas y distintas políticas de intervención en la fecundidad es otro foco de interés en este estudio.transición de la fecundidad, costo beneficio de los hijos, determinantes próximos de la fecundidad, flujo intergeneracional de riquezas, estatus de la mujer, fecundidad y género, políticas de población, intervención de la fecundidad

Ultrafine Particles in Ambient Air of an Urban Area: Dose Implications for Elderly

Due to their detrimental effects on human health, the scientific interest in ultrafine particles (UFP) has been increasing, but available information is far from comprehensive. Compared to the remaining population, the elderly are potentially highly susceptible to the effects of outdoor air pollution. Thus, this study aimed to (1) determine the levels of outdoor pollutants in an urban area with emphasis on UFP concentrations and (2) estimate the respective dose rates of exposure for elderly populations. UFP were continuously measured over 3 weeks at 3 sites in north Portugal: 2 urban (U1 and U2) and 1 rural used as reference (R1). Meteorological parameters and outdoor pollutants including particulate matter (PM10), ozone (O3), nitric oxide (NO), and nitrogen dioxide (NO2) were also measured. The dose rates of inhalation exposure to UFP were estimated for three different elderly age categories: 64–70, 71–80, and >81 years. Over the sampling period levels of PM10, O3 and NO2 were in compliance with European legislation. Mean UFP were 1.7 × 104 and 1.2 × 104 particles/cm3 at U1 and U2, respectively, whereas at rural site levels were 20–70% lower (mean of 1 ×104 particles/cm3). Vehicular traffic and local emissions were the predominant identified sources of UFP at urban sites. In addition, results of correlation analysis showed that UFP were meteorologically dependent. Exposure dose rates were 1.2- to 1.4-fold higher at urban than reference sites with the highest levels noted for adults at 71–80 yr, attributed mainly to higher inhalation rates

Contextualizando a saúde da população negra

Unidade 1 do curso Saúde da População Negra, contendo 03 atividades. Tem como objetivo identificar a Política Nacional de Saúde Integral da População Negra - PNSIPN - enquanto estratégia de aumento do acesso ao SUS e melhorar a qualidade do cuidado na Unidade de Saúde

Enfrentamento do racismo institucional

Unidade 3 do curso Saúde da População Negra, contendo 4 atividades, cujo objetivo é atuar, pela perspectiva do cuidado, para implementação da Política Nacional de Saúde Integral da População Negra promovendo o acesso ao SUS e criando ou fortalecendo parcerias e redes de trabalho estratégicas no entorno da Unidade de Saúde