3,500 research outputs found

    Mean-Motion Resonances of High Order in Extrasolar Planetary Systems

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    Many multi-planet systems have been discovered in recent years. Some of them are in mean-motion resonances (MMR). Planet formation theory was successful in explaining the formation of 2:1, 3:1 and other low resonances as a result of convergent migration. However, higher order resonances require high initial orbital eccentricities in order to be formed by this process and these are in general unexpected in a dissipative disk. We present a way of generating large initial eccentricities using additional planets. This procedure allows us to form high order MMRs and predict new planets using a genetic N-body code.Comment: To appear in Proceedings: Extrasolar Planets in Multi-body Systems: Theory and Observations; Editors K. Gozdziewski, A. Niedzielski and J. Schneider; 5 pages, 2 figures

    Laplacian-Steered Neural Style Transfer

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    Neural Style Transfer based on Convolutional Neural Networks (CNN) aims to synthesize a new image that retains the high-level structure of a content image, rendered in the low-level texture of a style image. This is achieved by constraining the new image to have high-level CNN features similar to the content image, and lower-level CNN features similar to the style image. However in the traditional optimization objective, low-level features of the content image are absent, and the low-level features of the style image dominate the low-level detail structures of the new image. Hence in the synthesized image, many details of the content image are lost, and a lot of inconsistent and unpleasing artifacts appear. As a remedy, we propose to steer image synthesis with a novel loss function: the Laplacian loss. The Laplacian matrix ("Laplacian" in short), produced by a Laplacian operator, is widely used in computer vision to detect edges and contours. The Laplacian loss measures the difference of the Laplacians, and correspondingly the difference of the detail structures, between the content image and a new image. It is flexible and compatible with the traditional style transfer constraints. By incorporating the Laplacian loss, we obtain a new optimization objective for neural style transfer named Lapstyle. Minimizing this objective will produce a stylized image that better preserves the detail structures of the content image and eliminates the artifacts. Experiments show that Lapstyle produces more appealing stylized images with less artifacts, without compromising their "stylishness".Comment: Accepted by the ACM Multimedia Conference (MM) 2017. 9 pages, 65 figure

    VarDict: a novel and versatile variant caller for next-generation sequencing in cancer research

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    Accurate variant calling in next generation sequencing (NGS) is critical to understand cancer genomes better. Here we present VarDict, a novel and versatile variant caller for both DNA- and RNA-sequencing data. VarDict simultaneously calls SNV, MNV, InDels, complex and structural variants, expanding the detected genetic driver landscape of tumors. It performs local realignments on the fly for more accurate allele frequency estimation. VarDict performance scales linearly to sequencing depth, enabling ultra-deep sequencing used to explore tumor evolution or detect tumor DNA circulating in blood. In addition, VarDict performs amplicon aware variant calling for polymerase chain reaction (PCR)-based targeted sequencing often used in diagnostic settings, and is able to detect PCR artifacts. Finally, VarDict also detects differences in somatic and loss of heterozygosity variants between paired samples. VarDict reprocessing of The Cancer Genome Atlas (TCGA) Lung Adenocarcinoma dataset called known driver mutations in KRAS, EGFR, BRAF, PIK3CA and MET in 16% more patients than previously published variant calls. We believe VarDict will greatly facilitate application of NGS in clinical cancer research

    The TRENDS High-Contrast Imaging Survey. VI. Discovery of a Mass, Age, and Metallicity Benchmark Brown Dwarf

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    The mass and age of substellar objects are degenerate parameters leaving the evolutionary state of brown dwarfs ambiguous without additional information. Theoretical models are normally used to help distinguish between old, massive brown dwarfs and young, low mass brown dwarfs but these models have yet to be properly calibrated. We have carried out an infrared high-contrast imaging program with the goal of detecting substellar objects as companions to nearby stars to help break degeneracies in inferred physical properties such as mass, age, and composition. Rather than using imaging observations alone, our targets are pre-selected based on the existence of dynamical accelerations informed from years of stellar radial velocity (RV) measurements. In this paper, we present the discovery of a rare benchmark brown dwarf orbiting the nearby (d=18.69±0.19d=18.69\pm0.19 pc), solar-type (G9V) star HD 4747 ([Fe/H]=0.22±0.04-0.22\pm0.04) with a projected separation of only ρ=11.3±0.2\rho=11.3\pm0.2 AU (θ\theta \approx 0.6"). Precise Doppler measurements taken over 18 years reveal the companion's orbit and allow us to place strong constraints on its mass using dynamics (msin(i)=55.3±1.9MJm \sin(i) = 55.3\pm1.9M_J). Relative photometry (ΔKs=9.05±0.14\Delta K_s=9.05\pm0.14, MKs=13.00±0.14M_{K_s}=13.00\pm0.14, KsL=1.34±0.46K_s - L' = 1.34\pm0.46) indicates that HD 4747 B is most-likely a late-type L-dwarf and, if near the L/T transition, an intriguing source for studying cloud physics, variability, and polarization. We estimate a model-dependent mass of m=7213+3MJm=72^{+3}_{-13}M_J for an age of 3.31.9+2.33.3^{+2.3}_{-1.9} Gyr based on gyrochronology. Combining astrometric measurements with RV data, we calculate the companion dynamical mass (m=60.2±3.3MJm=60.2\pm3.3M_J) and orbit (e=0.740±0.002e=0.740\pm0.002) directly. As a new mass, age, and metallicity benchmark, HD 4747 B will serve as a laboratory for precision astrophysics to test theoretical models that describe the emergent radiation of brown dwarfs.Comment: Accepted to Ap

    Determination of Allergen Levels, Isoforms, and Their Hydroxyproline Modifications Among Peanut Genotypes by Mass Spectrometry

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    The recently published reference genome of peanuts enables a detailed molecular description of the allergenic proteins of the seed. We used LC-MS/MS to investigate peanuts of different genotypes to assess variability and to better describe naturally occurring allergens and isoforms. Using relative quantification by mass spectrometry, minor variation of some allergenic proteins was observed, but total levels of Ara h 1, 2, 3, and 6 were relatively consistent among 20 genotypes. Previously published RPHPLC methodology was used for comparison. The abundance of three Ara h 3 isoforms were variable among the genotypes and contributed to a large proportion of total Ara h 3 where present. Previously unpublished hydroxyproline sites were identified in Ara h 1 and 3. Hydroxylation did not vary significantly where sites were present. Peanut allergen composition was largely stable, with only some isoforms displaying differences between genotypes. The resulting differences in allergenicity are of unknown clinical significance but are likely to be minor. The data presented herein allow for the design of targeted MS methodology to allow the quantitation and therefore control of peanut allergens of clinical relevance and observed variability

    Subcutaneous furosemide in advanced heart failure: service improvement project

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    Objectives: In severe heart disease, parenteral administration of loop diuretic is often needed. We present clinical outcomes from episodes of care using subcutaneous continuous infusion of furosemide (CSCI-furosemide).Methods: Retrospective review of service improvement data. The heart failure nurse specialist, supported by the heart failure-palliative care multi-disciplinary team, works with the community or hospice staff who administer the CSCI-furosemide. Data collected for consecutive patients receiving CSCI-furosemide included: age, sex, New York Heart Association (NYHA) class, preferred place of care, goal of treatment, infusion-site reactions, and signs and symptoms of fluid retention (including weight and self-reported breathlessness).Results: 116 people (men 86 [66%]; mean age 79 years, 49 to 97; NYHA class 3 [36/116, 31%] or 4 heart failure [80/116, 69%]) received 130 episodes of CSCI-furosemide (average duration 10 days, 1 to 49), over half in the patient’s own home/care home (80/129,; 61%) aiming to prevent hospital admission. 40/129 (31%) were managed in the hospice, and 9 (7.0%) in a community hospital. Average daily furosemide dose was 125 mg (40 to 300mg). The goal of treatment was achieved in (119/130, 91.5%) episodes.The median reduction in weight was 4kg (interquartiles -7 kg to -2 kgs, -22 to +9 kgs). Self-reported breathlessness reduced from 8.2 (+/-1.9) to 5.2 (+/-1.8). Adverse events occurred in 31/130 (24%) episodes; all but 4/130 (3%, localised skin infection) were mild.Conclusions: These preliminary data indicate that CSCI-furosemide is safe and effective for people with severe heart failure. An adequately powered randomised controlled trial is indicated

    State public assistance spending and survival among adults with cancer

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    IMPORTANCE: Social determinants of health contribute to disparities in cancer outcomes. State public assistance spending, including Medicaid and cash assistance programs for socioeconomically disadvantaged individuals, may improve access to care; address barriers, such as food and housing insecurity; and lead to improved cancer outcomes for marginalized populations. OBJECTIVE: To determine whether state-level public assistance spending is associated with overall survival (OS) among individuals with cancer, overall and by race and ethnicity. DESIGN, SETTING, AND PARTICIPANTS: This cohort study included US adults aged at least 18 years with a new cancer diagnosis from 2007 to 2013, with follow-up through 2019. Data were obtained from the Surveillance, Epidemiology, and End Results program. Data were analyzed from November 18, 2021, to July 6, 2023. EXPOSURE: Differential state-level public assistance spending. MAIN OUTCOME AND MEASURE: The main outcome was 6-year OS. Analyses were adjusted for age, race, ethnicity, sex, metropolitan residence, county-level income, state fixed effects, state-level percentages of residents living in poverty and aged 65 years or older, cancer type, and cancer stage. RESULTS: A total 2 035 977 individuals with cancer were identified and included in analysis, with 1 005 702 individuals (49.4%) aged 65 years or older and 1 026 309 (50.4%) male. By tertile of public assistance spending, 6-year OS was 55.9% for the lowest tertile, 55.9% for the middle tertile, and 56.6% for the highest tertile. In adjusted analyses, public assistance spending at the state-level was significantly associated with higher 6-year OS (0.09% [95% CI, 0.04%-0.13%] per 100percapita;P3˘c.001),particularlyfornonHispanicBlackindividuals(0.29100 per capita; P \u3c .001), particularly for non-Hispanic Black individuals (0.29% [95% CI, 0.07%-0.52%] per 100 per capita; P = .01) and non-Hispanic White individuals (0.12% [95% CI, 0.08%-0.16%] per 100percapita;P3˘c.001).InsensitivityanalysesexaminingtherolesofMedicaidspendingandMedicaidexpansionincludingadditionalyearsofdata,nonMedicaidspendingwasassociatedwithhigher3yearOSamongnonHispanicBlackindividuals(0.49100 per capita; P \u3c .001). In sensitivity analyses examining the roles of Medicaid spending and Medicaid expansion including additional years of data, non-Medicaid spending was associated with higher 3-year OS among non-Hispanic Black individuals (0.49% [95% CI, 0.26%-0.72%] per 100 per capita when accounting for Medicaid spending; 0.17% [95% CI, 0.02%-0.31%] per $100 per capita Medicaid expansion effects). CONCLUSIONS AND RELEVANCE: This cohort study found that state public assistance expenditures, including cash assistance programs and Medicaid, were associated with improved survival for individuals with cancer. State investment in public assistance programs may represent an important avenue to improve cancer outcomes through addressing social determinants of health and should be a topic of further investigation
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