488 research outputs found
Grades 3-5 Genres in Literature
This is an English language arts lesson for grades three through five on studying genres in literature. Through this lesson students will gain an understanding of the literary elements of each genre, improve comprehension by interpreting, analyzing, synthesizing, and evaluating written text in order to categorize. Students will also be able to identify characteristics of different genres, select genres that interest them, and be able to compare and contrast different works of literature with each other. This lesson spans over ten days and offers a variety of projects using a tic-tack-toe chart on three tiered levels where students can choose their favorite activity in each subject area to create a line based on their interests
Attenuation of choroidal tickness in patients with Alzheimer disease: evidence from an Italian prospective study
INTRODUCTION: To compare the 12-month choroidal thickness (CT) change between
Alzheimer disease (AD) patients and normal subjects.
METHODS: In this prospective, observational study, 39 patients with a diagnosis
of mild to moderate AD and 39 age-matched control subjects were included. All the
subjects underwent neuropsychological (Mini Mental State Examination, Alzheimer
disease Assessment Scale-Cognitive Subscale, and the Clinical Dementia Rating
Scale) and ophthalmological evaluation, including spectral domain optical
coherence tomography, at baseline and after 12 months. CT was measured manually
using the caliper tool of the optical coherence tomography device.
RESULTS: After 12 months, AD patients had a greater reduction of CT than controls
(P≤0.05, adjusted for baseline CT, age, sex, axial length, and smoking).
DISCUSSION: CT in patients with AD showed a rate of thinning greater than what
could be expected during the natural course of aging
Concurrent inhibition of enzymatic activity and NF-Y-mediated transcription of Topoisomerase-IIα by bis-DemethoxyCurcumin in cancer cells
Topoisomerase-IIa (TOP2A) enzyme is essential for cell viability due to its fundamental role in DNA metabolism and in
chromatin organization during interphase and mitosis. TOP2A expression is finely regulated at the transcriptional level through
the binding of the CCAAT-transcription factor NF-Y to its promoter. Overexpression and/or amplification of TOP2A have been
observed in many types of cancers. For this reason, TOP2A is the target of the most widely successful drugs in cancer
chemotherapy, such as TOP2A poisons, which stabilize TOP2A-DNA cleavage complexes and create DSBs, leading to
chromosome damage and cell death. We previously reported that the Curcumin-derivative bis-DemethoxyCurcumin (bDMC) is an anti-proliferative agent that inhibits cell growth by concomitant G1/S and G2/M arrest. Here we showed that bDMC irreversibly induces DSBs in cancer cells, but not in normal cells, by targeting TOP2A activity and expression. TOP2A ablation by siRNA corroborates its contribution to apoptosis induced by bDMC. Short-term exposure to bDMC induces retention of TOP2A-DNA intermediates, while longer exposure inhibits TOP2A transcription by affecting expression and sub-cellular localization of NF-Y subunits. ChIP analysis highlighted reduced recruitment of NF-Y to TOP2A regulatory regions, concomitantly to histone
deacetylation and decreased gene transcription. Our findings suggest that the dual activity of bDMC on TOP2A represents a
novel therapeutic strategy to induce persistent apoptosis in cancer cells and identify NF-Y regulation as a promising approach in anti-cancer therapy
NF-Y loss triggers p53 stabilization and apoptosis in HPV18-positive cells by affecting E6 transcription
The expression of the high risk HPV18 E6 and E7 oncogenic proteins induces the transformation of epithelial cells, through the disruption of p53 and Rb function. The binding of cellular transcription factors to cis-regulatory elements in the viral Upstream Regulatory Region (URR) stimulates E6/E7 transcription. Here, we demonstrate that the CCAAT-transcription factor NF-Y binds to a non-canonical motif within the URR and activates viral gene expression. In addition, NF-Y indirectly up-regulates HPV18 transcription through the transactivation of multiple cellular transcription factors. NFYA depletion inhibits the expression of E6 and E7 genes and re-establishes functional p53. The activation of p53 target genes in turn leads to apoptotic cell death. Finally, we show that NF-YA loss sensitizes HPV18-positive cells toward the DNA damaging agent Doxorubicin, via p53-mediated transcriptional response
Dynamic recruitment of NF-Y and histone acetyltransferases on cell-cycle promoters
Regulation of transcription during the cell-cycle is under the control of E2 factors (E2Fs), often in cooperation with nuclear factor Y (NF-Y), a histone-like CCAAT-binding trimer. NF-Y is paradigmatic of a constitutive, ubiquitous factor that pre-sets the promoter architecture for other regulatory proteins to access it. We analyzed the recruitment of NF-Y, E2F1/4/6, histone acetyltransferases, and histone deacetylase (HDAC) 1/3/4 to several cell-cycle promoters by chromatin immunoprecipitation assays in serum-starved and restimulated NIH3T3 cells. NF-Y binding is not constitutive but timely regulated in all promoters tested, being displaced when promoters are repressed. p300 association correlates with activation, and it is never found in the absence of NF-Y, whereas PCAF/hGCN5 is often found before NF-Y association. E2F4 and E2F6, together with HDACs, are bound to repressed promoters, including the G(2)/M Cyclin B2. As expected, an inverse relationship between HDACs association and histones H3/H4 acetylation is observed. Blocking cells in G(1) with the cyclin-dependent kinase 2 inhibitor R-roscovitine confirms that NF-Y is bound to G(1)/S but not to G(2)/M promoters in G(1). These data indicate that following the release of E2Fs/HDACs, a hierarchy of PCAF-NF-Y-p300 interactions and H3-H4 acetylations are required for activation of cell-cycle promoters
Opening the Floodgates or Filing the Gap: Perdomo v. Holder Advances the Ninth Circuit One Step Closer to Recognizing Gender-Based Asylum Claims
NF-Y activates genes of metabolic pathways altered in cancer cells
The trimeric transcription factor NF-Y binds to the CCAAT box, an element enriched in promoters of genes overexpressed in tumors. Previous studies on the NF-Y regulome identified the general term metabolism as significantly enriched. We dissect here in detail the targeting of metabolic genes by integrating analysis of NF-Y genomic binding and profilings after inactivation of NF-Y subunits in different cell types. NF-Y controls de novo biosynthetic pathways of lipids, teaming up with the master SREBPs regulators. It activates glycolytic genes, but, surprisingly, is neutral or represses mitochondrial respiratory genes. NF-Y targets the SOCG (Serine, One Carbon, Glycine) and Glutamine pathways, as well as genes involved in the biosynthesis of polyamines and purines. Specific cancer-driving nodes are generally under NF-Y control. Altogether, these data delineate a coherent strategy to promote expression of metabolic genes fuelling anaerobic energy production and other anabolic pathways commonly altered in cancer cells
Methods for Improving Efficiency of Planned Missing Data Designs
Any survey specifically constructed so that at least some variables are unobserved on a subset of participants is a planned missing data design, where missing data represent an intentional feature of the study. Use of planned missing data designs can potentially reduce costs, improve data quality, and reduce unplanned missing data, and advancements in missing data methodology and multiple imputation software make planned missing data designs more attractive than before. Two commonly used planned missing data designs are two-phase sampling and split questionnaire design. Two-phase sampling is used to improve the efficiency of an estimate for a single outcome that is costly to measure, while the split questionnaire design is primarily used to reduce survey length.
First, we propose new methods for selecting our second phase sample in two-phase surveys to reduce the variance of our estimate. When our outcome variable is continuous, we can use the data collected in Phase I for selecting our Phase II sample in order to increase the precision of the estimates. For other instances, we propose an adaptive sampling method to select Phase II samples in order to improve estimation of the quantity of interest.
Next, we examine the performance of several design allocations for implementing a split questionnaire survey in a longitudinal study. While many papers examined the administration of split questionnaire designs in cross-sectional studies, research in applying these methods to longitudinal studies has been limited. For our project, we focus on the commonly used 3-form design and propose several methods to administer the 3-form split questionnaire in a longitudinal study. Using simulations and data from the Health and Retirement Study, we compare the performance of each proposed design under several correlation structures.
Finally, we propose a method for improving variable allocation in split questionnaire designs. We establish a criterion that allows us to determine which variable allocations minimize the loss of information due to missing data. We use the Kullback-Leibler divergence between the posterior distribution of the parameters with missing data and the posterior distribution without missing data to locate optimal designs. After establishing a criterion for comparing designs, we propose a search algorithm to find optimal variable allocations, as it would be difficult to enumerate all possible designs as the number of variables grows.PHDBiostatisticsUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttps://deepblue.lib.umich.edu/bitstream/2027.42/144155/1/pimbri_1.pd
Histone Marks-Dependent Effect on Alternative Splicing: New Perspectives for Targeted Splicing Modulation in Cancer?
Alternative splicing (AS) is a tightly regulated mechanism that generates the complex human proteome from a small number of genes. Cis-regulatory RNA motifs in exons and introns control AS, recruiting positive and negative trans-acting splicing regulators. At a higher level, chromatin affects splicing events. Growing evidence indicates that the popular histone code hypothesis can be extended to RNA-level processes, such as AS. In addition to nucleosome positioning, which can generate transcriptional barriers to shape the final splicing outcome, histone post-translational modifications can contribute to the detailed regulation of single exon inclusion/exclusion. A histone-based system can identify alternatively spliced chromatin stretches, affecting RNAPII elongation locally or recruiting splicing components via adaptor complexes. In tumor cells, several mechanisms trigger misregulated AS events and produce cancer-associated transcripts. On a genome-wide level, aberrant AS can be the consequence of dysfunctional epigenetic splicing code, including altered enrichment in histone post-translational modifications. This review describes the main findings related to the effect of histone modifications and variants on splicing outcome and how a dysfunctional epigenetic splicing code triggers aberrant AS in cancer. In addition, it highlights recent advances in programmable DNA-targeting technologies and their possible application for AS targeted epigenetic modulation
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