2,426 research outputs found
Transcriptome Analysis of Targeted Mouse Mutations Reveals the Topography of Local Changes in Gene Expression.
The unintended consequences of gene targeting in mouse models have not been thoroughly studied and a more systematic analysis is needed to understand the frequency and characteristics of off-target effects. Using RNA-seq, we evaluated targeted and neighboring gene expression in tissues from 44 homozygous mutants compared with C57BL/6N control mice. Two allele types were evaluated: 15 targeted trap mutations (TRAP); and 29 deletion alleles (DEL), usually a deletion between the translational start and the 3' UTR. Both targeting strategies insert a bacterial beta-galactosidase reporter (LacZ) and a neomycin resistance selection cassette. Evaluating transcription of genes in +/- 500 kb of flanking DNA around the targeted gene, we found up-regulated genes more frequently around DEL compared with TRAP alleles, however the frequency of alleles with local down-regulated genes flanking DEL and TRAP targets was similar. Down-regulated genes around both DEL and TRAP targets were found at a higher frequency than expected from a genome-wide survey. However, only around DEL targets were up-regulated genes found with a significantly higher frequency compared with genome-wide sampling. Transcriptome analysis confirms targeting in 97% of DEL alleles, but in only 47% of TRAP alleles probably due to non-functional splice variants, and some splicing around the gene trap. Local effects on gene expression are likely due to a number of factors including compensatory regulation, loss or disruption of intragenic regulatory elements, the exogenous promoter in the neo selection cassette, removal of insulating DNA in the DEL mutants, and local silencing due to disruption of normal chromatin organization or presence of exogenous DNA. An understanding of local position effects is important for understanding and interpreting any phenotype attributed to targeted gene mutations, or to spontaneous indels
Involvement of protein kinase A in patterning of the mouse somatosensory cortex
Patterning of the mouse somatosensory cortex is unusually evident because of the presence of a "barrel field." Presynaptic serotonin and postsynaptic glutamate receptors regulate barrel formation, but little is known of the intracellular signaling pathways through which they act. To determine whether protein kinase A (PKA) plays a role in the development of the barrel field, we examined five viable PKA subunit-specific knock-out (KO) mouse lines for barrel field abnormalities. Barrels are present in these mice, but those lacking the RIIbeta subunit display significantly reduced contrast between the cell densities of barrel hollows and sides compared with wild-type animals. Thalamocortical afferent segregation in the posterior medial barrel subfield appeared normal, suggesting a postsynaptic site of gene action for the RIIbeta protein. Immunoelectron microscopy confirmed that RIIbeta was selectively localized to dendrites and dendritic spines. Mice lacking RIIbeta show reduced glutamate receptor A (GluRA) subunit insertion into the postsynaptic density in postnatal day 7 somatosensory cortex; however, GluRA KO mice developed normal barrels. Our results clearly demonstrate a role for postsynaptic PKA signaling pathways in barrel differentiation. They also demonstrate a clear dissociation between the regulation of GluRA trafficking by PKA and its role in barrel formation. Finally, although a role for PKA downstream of cAMP cannot be ruled out, these data suggest that PKA may not be the principle downstream target because none of the mutants showed a barrelless phenotype similar to that observed in adenylate cyclase type 1 KO mice. These results give insight into activity-dependent mechanisms that regulate barrel formation
Dyclonine rescues frataxin deficiency in animal models and buccal cells of patients with Friedreich's ataxia.
Inherited deficiency in the mitochondrial protein frataxin (FXN) causes the rare disease Friedreich's ataxia (FA), for which there is no successful treatment. We identified a redox deficiency in FA cells and used this to model the disease. We screened a 1600-compound library to identify existing drugs, which could be of therapeutic benefit. We identified the topical anesthetic dyclonine as protective. Dyclonine increased FXN transcript and FXN protein dose-dependently in FA cells and brains of animal models. Dyclonine also rescued FXN-dependent enzyme deficiencies in the iron-sulfur enzymes, aconitase and succinate dehydrogenase. Dyclonine induces the Nrf2 [nuclear factor (erythroid-derived 2)-like 2] transcription factor, which we show binds an upstream response element in the FXN locus. Additionally, dyclonine also inhibited the activity of histone methyltransferase G9a, known to methylate histone H3K9 to silence FA chromatin. Chronic dosing in a FA mouse model prevented a performance decline in balance beam studies. A human clinical proof-of-concept study was completed in eight FA patients dosed twice daily using a 1% dyclonine rinse for 1 week. Six of the eight patients showed an increase in buccal cell FXN levels, and fold induction was significantly correlated with disease severity. Dyclonine represents a novel therapeutic strategy that can potentially be repurposed for the treatment of FA
The Vitruvian nurse and burnout: New materialist approaches to impossible ideals
The Vitruvian Man is a metaphor for the "ideal man" by feminist posthuman philosopher Rosi Braidotti (2013) as a proxy for eurocentric humanist ideals. The first half of this paper extends Braidotti's concept by thinking about the metaphor of the "ideal nurse" (Vitruvian nurse) and how this metaphor contributes to racism, oppression, and burnout in nursing and might restrict the professionalization of nursing. The Vitruvian nurse is an idealized and perfected form of a nurse with self-sacrificial language (re)producing self-sacrificing expectations. The second half of this paper looks at how regulatory frameworks (using the example of UK's Nursing and Midwifery Council Code of Conduct) institutionalize the conditions of possibility through collective imaginations. The domineering expectations found within the Vitruvian nurse metaphor and further codified by regulatory frameworks give rise to boredom and burnout. The paper ends by suggesting possible ways to diffract regulatory frameworks to practice with affirmative ethics and reduce feelings of self-sacrifice and exhaustion among nurses
Understanding the New Dairy Market Coverage Program
This fact sheet alerts Utah dairy producers to a new program in the 2018 Farm Bill, Dairy Margin Coverage (DMC) that contains significant improvements to the dairy safety net by reducing costs and increasing coverage
Direct Measurements of Meltwater Runoff on the Greenland Ice Sheet Surface
Meltwater runoff from the Greenland Ice Sheet surface influences surface mass balance (SMB), ice dynamics and global sea level rise, but is estimated with climate models and thus difficult to validate. We present a way to measure ice surface runoff directly, from hourly in situ supraglacial river discharge measurements and simultaneous high-resolution satellite/drone remote sensing of upstream fluvial catchment area. A first 72-hour trial for a 63.1 square kilometer moulin-terminating internally drained catchment (IDC) on Greenland's mid-elevation (1207-1381 meters above sea level) ablation zone is compared with melt and runoff simulations from HIRHAM5, MAR3.6.1 (Modele Atmospherique Regionale 3.6.1), RACMO2.3 (Regional Atmospheric Climate Model 2.3), MERRA-2 (Modern Era Retrospective-analysis for Research and Applications-2) and SEB climate/SMB models. Current models cannot reproduce peak discharges or timing of runoff entering moulins, but are improved using synthetic unit hydrograph theory (SUH). Retroactive SUH applications to two older field studies reproduces their findings, signifying that remotely sensed IDC area, shape, and river-length are useful for predicting delays in peak runoff delivery to moulins. Applying SUH to HIRHAM5, MAR3.6.1, RACMO2.3 gridded melt products for 799 surrounding IDCs suggests their terminal moulins receive lower peak discharges, less diurnal variability, and asynchronous runoff timing relative to climate/SMB model output alone. Conversely, large IDCs produce high moulin discharges, even at high elevations where melt rates are low. During this particular field experiment models overestimated runoff by plus 21 percent to plus 58 percent, linked to overestimated ablation and possible meltwater retention in bare, low-density ice. Direct measurements of ice surface runoff will improve climate/SMB models, and incorporating remotely sensed IDCs will aid coupling of surface mass balance with ice dynamics and subglacial systems
The Vitruvian nurse and burnout: New materialist approaches to impossible ideals
The Vitruvian Man is a metaphor for the “ideal man” by feminist posthuman philosopher Rosi Braidotti (2013) as a proxy for eurocentric humanist ideals. The first half of this paper extends Braidotti's concept by thinking about the metaphor of the “ideal nurse” (Vitruvian nurse) and how this metaphor contributes to racism, oppression, and burnout in nursing and might restrict the professionalization of nursing. The Vitruvian nurse is an idealized and perfected form of a nurse with self-sacrificial language (re)producing self-sacrificing expectations. The second half of this paper looks at how regulatory frameworks (using the example of UK's Nursing and Midwifery Council Code of Conduct) institutionalize the conditions of possibility through collective imaginations. The domineering expectations found within the Vitruvian nurse metaphor and further codified by regulatory frameworks give rise to boredom and burnout. The paper ends by suggesting possible ways to diffract regulatory frameworks to practice with affirmative ethics and reduce feelings of self-sacrifice and exhaustion among nurses
Rhetoric or Change? The Role of State Policies and Conditions in Shaping Postsecondary Education Access and Success for Rural Students
Since the 2016 U.S. presidential election, increasing attention has been paid to rural communities. For our study, we used a multicase study approach that included five states to study the difference between the rhetoric about the need to focus more attention on rural communities soon after the 2016 election and the practiced reality of state conditions (e.g., policies, practices, constraints) changing to support postsecondary education outcomes (e.g., enrollment, retention, and graduation) for rural students between 2017 and 2021. We collected and analyzed two forms of data for our study, legislative records and newspaper articles. We noted inequitable funding for rural K–12 education in several states. While some state policymakers responded to these inequities, their responses raised questions about the unintended consequences for some of the decisions. In addition, we found state policymakers and leaders have placed increased attention on postsecondary education enrollment and affordability, but we found limited evidence that attention was paid to rural students and rural-serving higher education institutions and to postsecondary education retention and graduation for rural students
Measurements of the pp → ZZ production cross section and the Z → 4ℓ branching fraction, and constraints on anomalous triple gauge couplings at √s = 13 TeV
Four-lepton production in proton-proton collisions, pp -> (Z/gamma*)(Z/gamma*) -> 4l, where l = e or mu, is studied at a center-of-mass energy of 13 TeV with the CMS detector at the LHC. The data sample corresponds to an integrated luminosity of 35.9 fb(-1). The ZZ production cross section, sigma(pp -> ZZ) = 17.2 +/- 0.5 (stat) +/- 0.7 (syst) +/- 0.4 (theo) +/- 0.4 (lumi) pb, measured using events with two opposite-sign, same-flavor lepton pairs produced in the mass region 60 4l) = 4.83(-0.22)(+0.23) (stat)(-0.29)(+0.32) (syst) +/- 0.08 (theo) +/- 0.12(lumi) x 10(-6) for events with a four-lepton invariant mass in the range 80 4GeV for all opposite-sign, same-flavor lepton pairs. The results agree with standard model predictions. The invariant mass distribution of the four-lepton system is used to set limits on anomalous ZZZ and ZZ. couplings at 95% confidence level: -0.0012 < f(4)(Z) < 0.0010, -0.0010 < f(5)(Z) < 0.0013, -0.0012 < f(4)(gamma) < 0.0013, -0.0012 < f(5)(gamma) < 0.0013
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