1,594 research outputs found
The sloppy model universality class and the Vandermonde matrix
In a variety of contexts, physicists study complex, nonlinear models with
many unknown or tunable parameters to explain experimental data. We explain why
such systems so often are sloppy; the system behavior depends only on a few
`stiff' combinations of the parameters and is unchanged as other `sloppy'
parameter combinations vary by orders of magnitude. We contrast examples of
sloppy models (from systems biology, variational quantum Monte Carlo, and
common data fitting) with systems which are not sloppy (multidimensional linear
regression, random matrix ensembles). We observe that the eigenvalue spectra
for the sensitivity of sloppy models have a striking, characteristic form, with
a density of logarithms of eigenvalues which is roughly constant over a large
range. We suggest that the common features of sloppy models indicate that they
may belong to a common universality class. In particular, we motivate focusing
on a Vandermonde ensemble of multiparameter nonlinear models and show in one
limit that they exhibit the universal features of sloppy models.Comment: New content adde
Mice lacking epidermal PPARγ exhibit a marked augmentation in photocarcinogenesis associated with increased UVB-induced apoptosis, inflammation and barrier dysfunction
Recent studies suggest that peroxisome proliferator-activated receptor gamma (PPARγ) agonists may have cancer chemopreventive activity. Other studies have shown that loss of epidermal PPARγ results in enhanced chemical carcinogenesis in mice via unknown mechanisms. However, ultraviolet B (UVB) exposure represents the primary etiological agent for skin cancer formation and the role of PPARγ in photobiology and photocarcinogenesis is unknown. In previous studies, we demonstrated that UVB irradiation of cells results in the formation of oxidized glycerophosphocholines that exhibit PPARγ ligand activity. We therefore hypothesized that PPARγ would prove to be a chemopreventive target in photocarcinogenesis. We first showed that UVB irradiation of mouse skin causes generation of PPARγ agonist species in vivo. We then generated SKH-1 hairless, albino mice deficient in epidermal Pparg (Pparg-/-(epi)) using a cytokeratin 14 driven Cre-LoxP strategy. Using a chronic model of UVB photocarcinogenesis, we next showed that Pparg-/-(epi) mice exhibit an earlier onset of tumor formation, increased tumor burden and tumor progression. Increased tumor burden in Pparg-/-(epi) mice was accompanied by a significant increase in epidermal hyperplasia and p53 positive epidermal cells in surrounding skin lacking tumors. After acute UVB irradiation, Pparg-/-(epi) mice exhibited an augmentation of both UVB-induced Caspase 3/7 activity and inflammation. Increased apoptosis and inflammation was also observed after treatment with the PPARγ antagonist GW9662. With chronic UVB irradiation, Pparg-/-(epi) mice exhibited a sustained increase in erythema and transepidermal water loss relative to wildtype littermates. This suggests that PPARγ agonists could have possible chemopreventive activity in non-melanoma skin cancer
Integrating genetic regulation and single-cell expression with GWAS prioritizes causal genes and cell types for glaucoma
Primary open-angle glaucoma (POAG), characterized by retinal ganglion cell death, is a leading cause of irreversible blindness worldwide; however, the molecular and cellular causes are not well understood. Elevated intraocular pressure (IOP) is a major risk factor, but many patients have normal IOP. Colocalization and Mendelian randomization analysis of >240 POAG and IOP genome-wide association study (GWAS) loci and of overlapping expression and splicing quantitative trait loci (e/QTLs and sQTLs) in 49 GTEx tissues and retina prioritizesd causal genes for 60% of loci. These genes awere enriched in pathways implicated in extracellular matrix organization, cell adhesion, and vascular development. Analysis of single-nucleus RNA-seq of glaucoma-relevant eye tissues revealesd that the colocalizing genes and genome-wide POAG and IOP associations awere enriched in specific cell types in the aqueous outflow pathways, retina, optic nerve head, peripapillary sclera, and choroid. This study nominatesd IOP-dependent and independent regulatory mechanisms, genes, and cell types that may contribute to POAG pathogenesis
INTERVENTIONAL CARDIOLOGY FELLOWS AND PROCEDURAL COMPLICATIONS AFTER PERCUTANEOUS CORONARY INTERVENTION
Ultra-deep sequencing reveals the mutational landscape of classical Hodgkin lymphoma
UNLABELLED: The malignant Hodgkin and Reed Sternberg (HRS) cells of classical Hodgkin lymphoma (cHL) are scarce in affected lymph nodes, creating a challenge to detect driver somatic mutations. As an alternative to cell purification techniques, we hypothesized that ultra-deep exome sequencing would allow genomic study of HRS cells, thereby streamlining analysis and avoiding technical pitfalls. To test this, 31 cHL tumor/normal pairs were exome sequenced to approximately 1,000× median depth of coverage. An orthogonal error-corrected sequencing approach verified \u3e95% of the discovered mutations. We identified mutations in genes novel to cHL including: CDH5 and PCDH7, novel stop gain mutations in IL4R, and a novel pattern of recurrent mutations in pathways regulating Hippo signaling. As a further application of our exome sequencing, we attempted to identify expressed somatic single-nucleotide variants (SNV) in single-nuclei RNA sequencing (snRNA-seq) data generated from a patient in our cohort. Our snRNA analysis identified a clear cluster of cells containing a somatic SNV identified in our deep exome data. This cluster has differentially expressed genes that are consistent with genes known to be dysregulated in HRS cells (e.g., PIM1 and PIM3). The cluster also contains cells with an expanded B-cell clonotype further supporting a malignant phenotype. This study provides proof-of-principle that ultra-deep exome sequencing can be utilized to identify recurrent mutations in HRS cells and demonstrates the feasibility of snRNA-seq in the context of cHL. These studies provide the foundation for the further analysis of genomic variants in large cohorts of patients with cHL.
SIGNIFICANCE: Our data demonstrate the utility of ultra-deep exome sequencing in uncovering somatic variants in Hodgkin lymphoma, creating new opportunities to define the genes that are recurrently mutated in this disease. We also show for the first time the successful application of snRNA-seq in Hodgkin lymphoma and describe the expression profile of a putative cluster of HRS cells in a single patient
Who Cares About Being Gentle? The Impact of Social Identity and the Gender of One’s Friends on Children’s Display of Same-Gender Favoritism
This research assessed children’s same-gender favoritism by examining whether children value traits descriptive of their own gender more than traits descriptive of the other gender. We also investigated whether children’s proportion of same-gender friends relates to their same-gender favoritism. Eighty-one third and fourth grade children from the Midwest and West Coast of the U.S. rated how well 19 personality traits describe boys and girls, and how important each trait is for their gender to possess. Results replicate and extend past trait assignment research by demonstrating that both genders valued same-gender traits significantly more than other-gender traits. Results also indicated that boys with many same-gender friends derogated feminine-stereotyped traits, which has implications for research on masculinity norms within male-dominated peer groups
Protocols for Endovascular Stroke Treatment Diminish the Weekend Effect Through Improvements in Off-Hours Care
Introduction: The weekend effect is a well-recognized phenomenon in which patient outcomes worsen for acute strokes presenting outside routine business hours. This is attributed to non-uniform availability of services throughout the week and evenings and, though described for intravenous thrombolysis candidates, is poorly understood for endovascular stroke care. We evaluated the impact of institutional protocols on the weekend effect, and the speed and outcome of endovascular therapy as a function of time of presentation.Method: This study assesses a prospective observational cohort of 129 consecutive patients. Patients were grouped based on the time of presentation during regular work hours (Monday through Friday, 07:00–19:00 h) vs. off-hours (overnight 19:00–07:00 h and weekends) and assessed for treatment latency and outcome.Results: Treatment latencies did not depend on the time of presentation. The door to imaging interval was comparable during regular and off-hours (median time 21 vs. 19 min, respectively, p < 0.50). Imaging to groin puncture was comparable (71 vs. 71 min, p < 1.0), as were angiographic and functional outcomes. Additionally, treatment intervals decreased with increased protocol experience; door-to-puncture interval significantly decreased from the first to the fourth quarters of the study period (115 vs. 94 min, respectively, p < 0.006), with the effect primarily seen during off-hours with a 28% reduction in median door-to-puncture times.Conclusions: Institutional protocols help diminish the weekend effect in endovascular stroke treatment. This is driven largely by improvement in off-hours performance, with protocol adherence leading to further decreases in treatment intervals over time
Carfilzomib and dexamethasone versus bortezomib and dexamethasone for patients with relapsed or refractory multiple myeloma (ENDEAVOR): And randomised, phase 3, open-label, multicentre study
Background: Bortezomib with dexamethasone is a standard treatment option for relapsed or refractory multiple myeloma. Carfilzomib with dexamethasone has shown promising activity in patients in this disease setting. The aim of this study was to compare the combination of carfilzomib and dexamethasone with bortezomib and dexamethasone in patients with relapsed or refractory multiple myeloma. Methods: In this randomised, phase 3, open-label, multicentre study, patients with relapsed or refractory multiple myeloma who had one to three previous treatments were randomly assigned (1:1) using a blocked randomisation scheme (block size of four) to receive carfilzomib with dexamethasone (carfilzomib group) or bortezomib with dexamethasone (bortezomib group). Randomisation was stratified by previous proteasome inhibitor therapy, previous lines of treatment, International Staging System stage, and planned route of bortezomib administration if randomly assigned to bortezomib with dexamethasone. Patients received treatment until progression with carfilzomib (20 mg/m2 on days 1 and 2 of cycle 1; 56 mg/m2 thereafter; 30 min intravenous infusion) and dexamethasone (20 mg oral or intravenous infusion) or bortezomib (1·3 mg/m2; intravenous bolus or subcutaneous injection) and dexamethasone (20 mg oral or intravenous infusion). The primary endpoint was progression-free survival in the intention-to-treat population. All participants who received at least one dose of study drug were included in the safety analyses. The study is ongoing but not enrolling participants; results for the interim analysis of the primary endpoint are presented. The trial is registered at ClinicalTrials.gov, number NCT01568866. Findings: Between June 20, 2012, and June 30, 2014, 929 patients were randomly assigned (464 to the carfilzomib group; 465 to the bortezomib group). Median follow-up was 11·9 months (IQR 9·3-16·1) in the carfilzomib group and 11·1 months (8·2-14·3) in the bortezomib group. Median progression-free survival was 18·7 months (95% CI 15·6-not estimable) in the carfilzomib group versus 9·4 months (8·4-10·4) in the bortezomib group at a preplanned interim analysis (hazard ratio [HR] 0·53 [95% CI 0·44-0·65]; p<0·0001). On-study death due to adverse events occurred in 18 (4%) of 464 patients in the carfilzomib group and in 16 (3%) of 465 patients in the bortezomib group. Serious adverse events were reported in 224 (48%) of 463 patients in the carfilzomib group and in 162 (36%) of 456 patients in the bortezomib group. The most frequent grade 3 or higher adverse events were anaemia (67 [14%] of 463 patients in the carfilzomib group vs 45 [10%] of 456 patients in the bortezomib group), hypertension (41 [9%] vs 12 [3%]), thrombocytopenia (39 [8%] vs 43 [9%]), and pneumonia (32 [7%] vs 36 [8%]). Interpretation: For patients with relapsed or refractory multiple myeloma, carfilzomib with dexamethasone could be considered in cases in which bortezomib with dexamethasone is a potential treatment option. Funding: Onyx Pharmaceuticals, Inc., an Amgen subsidiary
Strong Carbon Features and a Red Early Color in the Underluminous Type Ia SN 2022xkq
We present optical, infrared, ultraviolet, and radio observations of SN
2022xkq, an underluminous fast-declining type Ia supernova (SN Ia) in NGC 1784
( Mpc), from to 180 days after explosion. The
high-cadence observations of SN 2022xkq, a photometrically transitional and
spectroscopically 91bg-like SN Ia, cover the first days and weeks following
explosion which are critical to distinguishing between explosion scenarios. The
early light curve of SN 2022xkq has a red early color and exhibits a flux
excess which is more prominent in redder bands; this is the first time such a
feature has been seen in a transitional/91bg-like SN Ia. We also present 92
optical and 19 near-infrared (NIR) spectra, beginning 0.4 days after explosion
in the optical and 2.6 days after explosion in the NIR. SN 2022xkq exhibits a
long-lived C I 1.0693 m feature which persists until 5 days post-maximum.
We also detect C II 6580 in the pre-maximum optical spectra. These
lines are evidence for unburnt carbon that is difficult to reconcile with the
double detonation of a sub-Chandrasekhar mass white dwarf. No existing
explosion model can fully explain the photometric and spectroscopic dataset of
SN 2022xkq, but the considerable breadth of the observations is ideal for
furthering our understanding of the processes which produce faint SNe Ia.Comment: 38 pages, 16 figures, accepted for publication in ApJ, the figure 15
input models and synthetic spectra are now available at
https://zenodo.org/record/837925
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