96 research outputs found
Dramatic Repositioning of c-Myb to Different Promoters during the Cell Cycle Observed by Combining Cell Sorting with Chromatin Immunoprecipitation
The c-Myb transcription factor is a critical regulator of proliferation and stem cell differentiation, and mutated alleles of c-Myb are oncogenic, but little is known about changes in c-Myb activity during the cell cycle. To map the association of c-Myb with specific target genes during the cell cycle, we developed a novel Fix-Sort-ChIP approach, in which asynchronously growing cells were fixed with formaldehyde, stained with Hoechst 33342 and separated into different cell cycle fractions by flow sorting, then processed for chromatin immunoprecipitation (ChIP) assays. We found that c-Myb actively repositions, binding to some genes only in specific cell cycle phases. In addition, the specificity of c-Myb is dramatically different in small subpopulations of cells, for example cells in the G2/M phase of the cell cycle, than in the bulk population. The repositioning of c-Myb during the cell cycle is not due to changes in its expression and also occurs with ectopically expressed, epitope-tagged versions of c-Myb. The repositioning occurs in established cell lines, in primary human CD34+ hematopoietic progenitors and in primary human acute myeloid leukemia cells. The combination of fixation, sorting and ChIP analysis sheds new light on the dynamic nature of gene regulation during the cell cycle and provides a new type of tool for the analysis of gene regulation in small subsets of cells, such as cells in a specific phase of the cell cycle
MicroRNA-146a and AMD3100, two ways to control CXCR4 expression in acute myeloid leukemias
CXCR4 is a negative prognostic marker in acute myeloid leukemias (AMLs). Therefore, it is necessary to develop novel ways to inhibit CXCR4 expression in leukemia. AMD3100 is an inhibitor of CXCR4 currently used to mobilize cancer cells. CXCR4 is a target of microRNA (miR)-146a that may represent a new tool to inhibit CXCR4 expression. We then investigated CXCR4 regulation by miR-146a in primary AMLs and found an inverse correlation between miR-146a and CXCR4 protein expression levels in all AML subtypes. As the lowest miR-146a expression levels were observed in M5 AML, we analyzed the control of CXCR4 expression by miR-146a in normal and leukemic monocytic cells and showed that the regulatory miR-146a/CXCR4 pathway operates during monocytopoiesis, but is deregulated in AMLs. AMD3100 treatment and miR-146a overexpression were used to inhibit CXCR4 in leukemic cells. AMD3100 treatment induces the decrease of CXCR4 protein expression, associated with miR-146a increase, and increases sensitivity of leukemic blast cells to cytotoxic drugs, this effect being further enhanced by miR-146a overexpression. Altogether our data indicate that miR-146a and AMD3100, acting through different mechanism, downmodulate CXCR4 protein levels, impair leukemic cell proliferation and then may be used in combination with anti-leukemia drugs, for development of new therapeutic strategies
APOKASC-3:The Third Joint Spectroscopic and Asteroseismic Catalog for Evolved Stars in the Kepler Fields
In the third APOKASC catalog, we present data for the complete sample of 15,808 evolved stars with APOGEE spectroscopic parameters and Kepler asteroseismology. We used 10 independent asteroseismic analysis techniques and anchor our system on fundamental radii derived from Gaia L and spectroscopic Teff. We provide evolutionary state, asteroseismic surface gravity, mass, radius, age, and the data used to derive them for 12,418 stars. This includes 10,036 exceptionally precise measurements, with median fractional uncertainties in νmax , Δν, mass, radius, and age of 0.6%, 0.6%, 3.8%, 1.8%, and 11.1%, respectively. We provide more limited data for 1624 additional stars that either have lower-quality data or are outside of our primary calibration domain. Using lower red giant branch (RGB) stars, we find a median age for the chemical thick disk of 9.14 ± 0.05(ran) ± 0.9(sys) Gyr with an age dispersion of 1.1 Gyr, consistent with our error model. We calibrate our red clump (RC) mass loss to derive an age consistent with the lower RGB and provide asymptotic GB and RGB ages for luminous stars. We also find a sharp upper-age boundary in the chemical thin disk. We find that scaling relations are precise and accurate on the lower RGB and RC, but they become more model dependent for more luminous giants and break down at the tip of the RGB. We recommend the use of multiple methods, calibration to a fundamental scale, and the use of stellar models to interpret frequency spacings
The eighteenth data release of the Sloan Digital Sky Surveys : targeting and first spectra from SDSS-V
The eighteenth data release of the Sloan Digital Sky Surveys (SDSS) is the first one for SDSS-V, the fifth generation of the survey. SDSS-V comprises three primary scientific programs, or "Mappers": Milky Way Mapper (MWM), Black Hole Mapper (BHM), and Local Volume Mapper (LVM). This data release contains extensive targeting information for the two multi-object spectroscopy programs (MWM and BHM), including input catalogs and selection functions for their numerous scientific objectives. We describe the production of the targeting databases and their calibration- and scientifically-focused components. DR18 also includes ~25,000 new SDSS spectra and supplemental information for X-ray sources identified by eROSITA in its eFEDS field. We present updates to some of the SDSS software pipelines and preview changes anticipated for DR19. We also describe three value-added catalogs (VACs) based on SDSS-IV data that have been published since DR17, and one VAC based on the SDSS-V data in the eFEDS field.Publisher PDFPeer reviewe
The Seventeenth Data Release of the Sloan Digital Sky Surveys: Complete Release of MaNGA, MaStar and APOGEE-2 Data
This paper documents the seventeenth data release (DR17) from the Sloan Digital Sky Surveys; the fifth and final release from the fourth phase (SDSS-IV). DR17 contains the complete release of the Mapping Nearby Galaxies at Apache Point Observatory (MaNGA) survey, which reached its goal of surveying over 10,000 nearby galaxies. The complete release of the MaNGA Stellar Library (MaStar) accompanies this data, providing observations of almost 30,000 stars through the MaNGA instrument during bright time. DR17 also contains the complete release of the Apache Point Observatory Galactic Evolution Experiment 2 (APOGEE-2) survey which publicly releases infra-red spectra of over 650,000 stars. The main sample from the Extended Baryon Oscillation Spectroscopic Survey (eBOSS), as well as the sub-survey Time Domain Spectroscopic Survey (TDSS) data were fully released in DR16. New single-fiber optical spectroscopy released in DR17 is from the SPectroscipic IDentification of ERosita Survey (SPIDERS) sub-survey and the eBOSS-RM program. Along with the primary data sets, DR17 includes 25 new or updated Value Added Catalogs (VACs). This paper concludes the release of SDSS-IV survey data. SDSS continues into its fifth phase with observations already underway for the Milky Way Mapper (MWM), Local Volume Mapper (LVM) and Black Hole Mapper (BHM) surveys
Pathway-based predictive approaches for non-animal assessment of acute inhalation toxicity
New approaches are needed to assess the effects of inhaled substances on human health. These approaches will be based on mechanisms of toxicity, an understanding of dosimetry, and the use of in silico modeling and in vitro test methods. In order to accelerate wider implementation of such approaches, development of adverse outcome pathways (AOPs) can help identify and address gaps in our understanding of relevant parameters for model input and mechanisms, and optimize non-animal approaches that can be used to investigate key events of toxicity. This paper describes the AOPs and the toolbox of in vitro and in silico models that can be used to assess the key events leading to toxicity following inhalation exposure. Because the optimal testing strategy will vary depending on the substance of interest, here we present a decision tree approach to identify an appropriate non-animal integrated testing strategy that incorporates consideration of a substance's physicochemical properties, relevant mechanisms of toxicity, and available in silico models and in vitro test methods. This decision tree can facilitate standardization of the testing approaches. Case study examples are presented to provide a basis for proof-of-concept testing to illustrate the utility of non-animal approaches to inform hazard identification and risk assessment of humans exposed to inhaled substances
Low vitamin D status is associated with systemic and gastrointestinal inflammation in dogs with a chronic enteropathy
Vitamin D is traditionally known for its role in calcium homeostasis and bone metabolism.
However, it has been demonstrated that numerous types of cells express the vitamin D
receptor and it is now clear that the physiological roles of vitamin D extend beyond the
maintenance of skeletal health. Vitamin D insufficiency, which is typically assessed by
measuring the major circulating form of vitamin D, 25 hydroxyvitamin D (25(OH)D), has
been associated with a number of disorders in people including hypertension, diabetes,
cardiovascular diseases, cancer, autoimmune conditions and infectious diseases. Meta-analyses
have demonstrated that serum 25(OH)D concentrations are an important predictor
of survival in people with a wide variety of illnesses and have been linked to all-cause
mortality in the general human population.
The role of vitamin D in non-skeletal disorders in cats and dogs is poorly understood. This is
surprising since cats and dogs could act as excellent models for probing the biology of
vitamin D. Vitamin D status in people is largely dependent on cutaneous production of
vitamin D. This is influenced by many factors such as season, latitude and exposure to
ultraviolet (UV) radiation. The interpretation of human studies investigating the effects
vitamin D status on disease outcomes are therefore influenced by a number of confounding
variables. Unlike humans, domesticated cats and dogs do not produce vitamin D cutaneously
and obtain vitamin D only from their diet. The physiological functions and regulation of
vitamin D are otherwise similar to humans. Most pets are fed commercial diets containing a
relatively standard amount of vitamin D. Consequently, companion animals are attractive
model systems in which to examine the relationship vitamin D status and health outcomes.
Furthermore, spontaneously occurring model systems which did not require disease to be
induced in healthy animals would allow the numbers of animals used in scientist research to
be reduced.
This thesis aimed to define vitamin D homeostasis in companion animals in three disease
settings; in cats with feline immunodeficiency virus (FIV) infection, dogs with chronic
enteropathies (CE) and in hospitalised ill cats. Additional aims were to assess the prognostic
significance of serum 25(OH)D concentrations in companion animals and the relationship
between serum 25(OH)D concentrations and markers of inflammation. The hypothesis of
this thesis was that vitamin status D would negatively correlate with presence of disease,
markers of inflammation and disease outcomes. As similar findings have been demonstrated
in human medicine, the hypothesis was that cats and dogs would be suitable models to
investigate the role of vitamin D in human disease.
This thesis demonstrates that in dogs with a CE serum 25(OH)D concentrations are
negatively correlated with inflammation and are predictive of clinical outcomes. Vitamin D
status was also lower in cats with FIV and importantly vitamin D status was predictive of
short term mortality in hospitalised ill cats. This research will be of interest to veterinary
surgeons and opens the possibility for clinical trials which examine if low vitamin D status is
causally associated with ill health and whether vitamin D supplementation results in superior
treatment outcomes in companion animals. This thesis also demonstrates the potential of cats
and dogs as model systems in which to examine the role of vitamin D in human health
The Seventeenth Data Release of the Sloan Digital Sky Surveys: Complete Release of MaNGA, MaStar, and APOGEE-2 Data
This paper documents the seventeenth data release (DR17) from the Sloan Digital Sky Surveys; the fifth and final release from the fourth phase (SDSS-IV). DR17 contains the complete release of the Mapping Nearby Galaxies at Apache Point Observatory (MaNGA) survey, which reached its goal of surveying over 10,000 nearby galaxies. The complete release of the MaNGA Stellar Library accompanies this data, providing observations of almost 30,000 stars through the MaNGA instrument during bright time. DR17 also contains the complete release of the Apache Point Observatory Galactic Evolution Experiment 2 survey that publicly releases infrared spectra of over 650,000 stars. The main sample from the Extended Baryon Oscillation Spectroscopic Survey (eBOSS), as well as the subsurvey Time Domain Spectroscopic Survey data were fully released in DR16. New single-fiber optical spectroscopy released in DR17 is from the SPectroscipic IDentification of ERosita Survey subsurvey and the eBOSS-RM program. Along with the primary data sets, DR17 includes 25 new or updated value-added catalogs. This paper concludes the release of SDSS-IV survey data. SDSS continues into its fifth phase with observations already underway for the Milky Way Mapper, Local Volume Mapper, and Black Hole Mapper surveys
Developing an effective coaching framework that supports teachers with their literacy instruction in an elementary setting
The research question addressed in this project is, how to develop an effective coaching framework that supports teachers with their literacy instruction in an elementary setting? The motivating factor for this capstone was to find responsive ways to reach all teachers in spite of the lack of time in a work day. In addition, a need for more effective pathways to professional growth that is manageable and respectful to all learning styles. The key influences were the authors Dozier (2006), Boyles (2007), and L\u27Allier, S., Elish-Piper, L., & Nean, R.M. (2010). The project is a curriculum development project providing teachers with a flipped version of professional development in the area of literacy instructio
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