El presente artículo tiene como objetivo identificar algunas aproximaciones conceptuales sobre la desigualdad educativa de género en espacios familiares, en la escuela y en los medios de ...comunicación. Interrogantes como ¿cuáles son las atribuciones de género que se plantean en casa, en la escuela y en los medios? o ¿cómo se desenvuelven y participan los sujetos en espacios atribuidos como privados y espacios públicos que reflejan una diferenciación de género? son las que se propone resolver a través de una revisión documental. En este sentido, se recuperó, seleccionó y reinterpretó información sobre las desigualdades en México que se convierten en disparidades de género que conforman las experiencias de las mujeres.
Mycorrhizal fungi provide plants with a range of benefits, including mineral nutrients and protection from stress and pathogens. Here we synthesize current information about how the presence and type ...of mycorrhizal association affect plant communities. We argue that mycorrhizal fungi regulate seedling establishment and species coexistence through stabilizing and equalizing mechanisms such as soil nutrient partitioning, feedback to soil antagonists, differential mycorrhizal benefits, and nutrient trade. Mycorrhizal fungi have strong effects on plant population and community biology, with mycorrhizal type-specific effects on seed dispersal, seedling establishment, and soil niche differentiation, as well as interspecific and intraspecific competition and hence plant diversity.
Notch role in multipotency or cell fateMultipotent Drosophila intestinal stem cells (ISCs) generate either nutrient-absorbing enterocytes (ECs) or secretory enteroendocrine cells (EECs). Guo and ...Ohlstein investigated the role of Notch signaling in this process. They tracked ISC asymmetric divisions and found that EEC daughter cells, which have a low level of Notch, signal back to the ISC in order to keep it multipotent. However, during EC production, ISCs activate strong Notch signaling in daughters. Thus, Notch signaling functions in two directions to achieve stem cell multipotency.Science, this issue p. 10.1126/science.aab0988 Drosophila intestinal stem cells (ISCs) generate enterocytes (ECs) and enteroendocrine (ee) cells. Previous work suggests that different levels of the Notch ligand Delta (Dl) in ISCs unidirectionally activate Notch in daughters to control multipotency. However, the mechanisms driving different outcomes remain unknown. We found that during ee cell formation, the ee cell marker Prospero localizes to the basal side of dividing ISCs. After asymmetric division, the ee daughter cell acts as a source of Dl that induces low Notch activity in the ISC to maintain identity. Alternatively, ISCs expressing Dl induce high Notch activity in daughter cells to promote EC formation. Our data reveal a conserved role for Notch in Drosophila and mammalian ISC maintenance and suggest that bidirectional Notch signaling may regulate multipotency in other systems.
Time series of single-cell transcriptome measurements can reveal dynamic features of cell differentiation pathways. From measurements of whole frog embryos spanning zygotic genome activation through ...early organogenesis, we derived a detailed catalog of cell states in vertebrate development and a map of differentiation across all lineages over time. The inferred map recapitulates most if not all developmental relationships and associates new regulators and marker genes with each cell state. We find that many embryonic cell states appear earlier than previously appreciated. We also assess conflicting models of neural crest development. Incorporating a matched time series of zebrafish development from a companion paper, we reveal conserved and divergent features of vertebrate early developmental gene expression programs.
is an animal with few cells but a wide diversity of cell types. In this study, we characterize the molecular basis for their specification by profiling the transcriptomes of 86,024 single embryonic ...cells. We identify 502 terminal and preterminal cell types, mapping most single-cell transcriptomes to their exact position in
' invariant lineage. Using these annotations, we find that (i) the correlation between a cell's lineage and its transcriptome increases from middle to late gastrulation, then falls substantially as cells in the nervous system and pharynx adopt their terminal fates; (ii) multilineage priming contributes to the differentiation of sister cells at dozens of lineage branches; and (iii) most distinct lineages that produce the same anatomical cell type converge to a homogenous transcriptomic state.
Oxygen sensing is central to metazoan biology and has implications for human disease. Mammalian cells express multiple oxygen-dependent enzymes called 2-oxoglutarate (OG)-dependent dioxygenases ...(2-OGDDs), but they vary in their oxygen affinities and hence their ability to sense oxygen. The 2-OGDD histone demethylases control histone methylation. Hypoxia increases histone methylation, but whether this reflects direct effects on histone demethylases or indirect effects caused by the hypoxic induction of the HIF (hypoxia-inducible factor) transcription factor or the 2-OG antagonist 2-hydroxyglutarate (2-HG) is unclear. Here, we report that hypoxia promotes histone methylation in a HIF- and 2-HG-independent manner. We found that the H3K27 histone demethylase KDM6A/UTX, but not its paralog KDM6B, is oxygen sensitive. KDM6A loss, like hypoxia, prevented H3K27 demethylation and blocked cellular differentiation. Restoring H3K27 methylation homeostasis in hypoxic cells reversed these effects. Thus, oxygen directly affects chromatin regulators to control cell fate.
Massive open online courses (MOOCs) show great potential to transform traditional education through the Internet. However, the high attrition rates in MOOCs have often been cited as a scale-efficacy ...tradeoff. Traditional educational approaches are usually unable to identify such large-scale number of at-risk students in danger of dropping out in time to support effective intervention design. While building dropout prediction models using learning analytics are promising in informing intervention design for these at-risk students, results of the current prediction model construction methods do not enable personalized intervention for these students. In this study, we take an initial step to optimize the dropout prediction model performance toward intervention personalization for at-risk students in MOOCs. Specifically, based on a temporal prediction mechanism, this study proposes to use the deep learning algorithm to construct the dropout prediction model and further produce the predicted individual student dropout probability. By taking advantage of the power of deep learning, this approach not only constructs more accurate dropout prediction models compared with baseline algorithms but also comes up with an approach to personalize and prioritize intervention for at-risk students in MOOCs through using individual drop out probabilities. The findings from this study and implications are then discussed.
The relationship between sex/gender differences and autism has attracted a variety of research ranging from clinical and neurobiological to etiological, stimulated by the male bias in autism ...prevalence. Findings are complex and do not always relate to each other in a straightforward manner. Distinct but interlinked questions on the relationship between sex/gender differences and autism remain underaddressed. To better understand the implications from existing research and to help design future studies, we propose a 4-level conceptual framework to clarify the embedded themes.
We searched PubMed for publications before September 2014 using search terms “‘sex OR gender OR females’ AND autism.” A total of 1,906 articles were screened for relevance, along with publications identified via additional literature reviews, resulting in 329 articles that were reviewed.
Level 1, “Nosological and diagnostic challenges,” concerns the question, “How should autism be defined and diagnosed in males and females?” Level 2, “Sex/gender-independent and sex/gender-dependent characteristics,” addresses the question, “What are the similarities and differences between males and females with autism?” Level 3, “General models of etiology: liability and threshold,” asks the question, “How is the liability for developing autism linked to sex/gender?” Level 4, “Specific etiological–developmental mechanisms,” focuses on the question, “What etiological–developmental mechanisms of autism are implicated by sex/gender and/or sexual/gender differentiation?”
Using this conceptual framework, findings can be more clearly summarized, and the implications of the links between findings from different levels can become clearer. Based on this 4-level framework, we suggest future research directions, methodology, and specific topics in sex/gender differences and autism.
Sex determination in the mosquito Aedes aegypti is governed by a dominant male-determining factor (M factor) located within a Y chromosome–like region called the M locus. Here, we show that an ...M-locus gene, Nix, functions as an M factor in A. aegypti. Nix exhibits persistent M linkage and early embryonic expression, two characteristics required of an M factor. Nix knockout with clustered regularly interspaced short palindromic repeats (CRISPR)–Cas9 resulted in largely feminized genetic males and the production of female isoforms of two key regulators of sexual differentiation: doublesex and fruitless. Ectopic expression of Nix resulted in genetic females with nearly complete male genitalia. Thus, Nix is both required and sufficient to initiate male development. This study provides a foundation for mosquito control strategies that convert female mosquitoes into harmless males.
Aerobic glycolysis (the Warburg effect) is a metabolic hallmark of activated T cells and has been implicated in augmenting effector T cell responses, including expression f of the proinflammatory ...cytokine interferon-γ (IFN-γ), via 3 untranslated region (3'UTR)-mediated mechanisms. Here, we show that lactate dehydrogenase A (LDHA) is induced in activated T cells to support aerobic glycolysis but promotes IFN-γ expression independently of its 3'UTR. Instead, LDHA maintains high concentrations of acetyl-coenzyme A to enhance histone acetylation and transcription of Ifng. Ablation of LDHA in T cells protects mice from immunopathology triggered by excessive IFN-γ expression or deficiency of regulatory T cells. These findings reveal an epigenetic mechanism by which aerobic glycolysis promotes effector T cell differentiation and suggest that LDHA may be targeted therapeutically in autoinflammatory diseases.
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