462 research outputs found
Recommended from our members
Heterogeneity in Host Risk Factors for Incident Melanoma and Non-Melanoma Skin Cancer in a Cohort of US Women
Background: Melanoma, squamous cell carcinoma (SCC), and basal cell carcinoma (BCC) are 3 types of skin cancer that have distinct biologic characteristics and prognoses. We evaluated phenotypic differences in the risk of these cancers in US women. Methods: We conducted a prospective study of 113 139 female nurses from 1984 to 2002. Over the 18 years of follow-up, there were 375 cases of melanoma, 495 cases of SCC, and 9423 cases of BCC. Results: Women with melanoma were more likely to have a family history of melanoma (melanoma: RR 1.94, 95% confidence interval [CI] 1.36–2.76; SCC: RR 0.82, 95% CI 0.58–1.37; BCC: RR 1.49, 95% CI 1.38–1.62) and 6 or more moles on the left arm (melanoma: RR 3.66, 95% CI 2.15–6.24; SCC: RR 1.53, 95% CI 0.83–2.79; BCC: RR 1.48, 95% CI 1.28–1.72). Polytomous logistic regression analysis showed that age at diagnosis (P < 0.0001), family history of melanoma (P = 0.016), and number of moles on the left arm (P = 0.007) were significantly different across the 3 cancers. Conclusions: This prospective observational study demonstrated that known phenotypic factors for skin cancer have a differential impact on the risk of melanoma, SCC, and BCC
Weibull Racing Survival Analysis for Competing Events and a Study of Loan Payoff and Default
We propose Bayesian nonparametric Weibull delegate racing (WDR) to explicitly
model surviving under competing events and to interpret how the covariates
accelerate or decelerate the event times. WDR explains non-monotonic covariate
effects by racing a potentially infinite number of sub-events, relaxing the
ubiquitous proportional-hazards assumption which may be too restrictive. WDR
can handle different types of censoring and missing event times or types. For
inference, we develop a Gibbs-sampler-based MCMC algorithm along with a maximum
a posteriori estimation for big data applications. We use synthetic data
analysis to demonstrate the flexibility and parsimonious nonlinearity of WDR.
We also use a data set of time to loan payoff and default from Prosper.com to
showcase the interpretability.Comment: 40 pages, 7 figures, 14 table
A detection of the layered structure of nearby open clusters
We applied the newly developed rose diagram overlay method to detect the
layered structure of 88 nearby open clusters (500~pc) on the three
projections after the distance correction of their member stars, based on the
catalog in literature. The results show that with the rose diagram overlay
method, a total of 74 clusters in our sample have a layered structure, while
the remaining clusters are without a clear layered structure. We for the first
time defined the layered structure parameters for the sample clusters.
Meanwhile, we found that the layered circle core area () has a strong
positive correlation with the number of cluster members, while the kernel
instability index () has a strong negative correlation with the number of
cluster members. Our study provides a novel perspective for the detection of
the layered structure of open clusters.Comment: 11 pages, 9 figures, 6 tables, accepted for publication in A&
Recommended from our members
Association between Cutaneous Nevi and Breast Cancer in the Nurses' Health Study: A Prospective Cohort Study
Background: Cutaneous nevi are suggested to be hormone-related. We hypothesized that the number of cutaneous nevi might be a phenotypic marker of plasma hormone levels and predict subsequent breast cancer risk. Methods and Findings: We followed 74,523 female nurses for 24 y (1986–2010) in the Nurses' Health Study and estimate the relative risk of breast cancer according to the number of cutaneous nevi. We adjusted for the known breast cancer risk factors in the models. During follow-up, a total of 5,483 invasive breast cancer cases were diagnosed. Compared to women with no nevi, women with more cutaneous nevi had higher risks of breast cancer (multivariable-adjusted hazard ratio, 1.04, 95% confidence interval [CI], 0.98–1.10 for 1–5 nevi; 1.15, 95% CI, 1.00–1.31 for 6–14 nevi, and 1.35, 95% CI, 1.04–1.74 for 15 or more nevi; p for continuous trend = 0.003). Over 24 y of follow-up, the absolute risk of developing breast cancer increased from 8.48% for women without cutaneous nevi to 8.82% (95% CI, 8.31%–9.33%) for women with 1–5 nevi, 9.75% (95% CI, 8.48%–11.11%) for women with 6–14 nevi, and 11.4% (95% CI, 8.82%–14.76%) for women with 15 or more nevi. The number of cutaneous nevi was associated with increased risk of breast cancer only among estrogen receptor (ER)–positive tumors (multivariable-adjusted hazard ratio per five nevi, 1.09, 95% CI, 1.02–1.16 for ER+/progesterone receptor [PR]–positive tumors; 1.08, 95% CI, 0.94–1.24 for ER+/PR− tumors; and 0.99, 95% CI, 0.86–1.15 for ER−/PR− tumors). Additionally, we tested plasma hormone levels according to the number of cutaneous nevi among a subgroup of postmenopausal women without postmenopausal hormone use (n = 611). Postmenopausal women with six or more nevi had a 45.5% higher level of free estradiol and a 47.4% higher level of free testosterone compared to those with no nevi (p for trend = 0.001 for both). Among a subgroup of 362 breast cancer cases and 611 matched controls with plasma hormone measurements, the multivariable-adjusted odds ratio for every five nevi attenuated from 1.25 (95% CI, 0.89–1.74) to 1.16 (95% CI, 0.83–1.64) after adjusting for plasma hormone levels. Key limitations in this study are that cutaneous nevi were self-counted in our cohort and that the study was conducted in white individuals, and thus the findings do not necessarily apply to other populations. Conclusions: Our results suggest that the number of cutaneous nevi may reflect plasma hormone levels and predict breast cancer risk independently of previously known factors. Please see later in the article for the Editors' Summar
Searching for Variable Stars in the Open Cluster NGC 2355 and Its Surrounding Region
We have investigated the variable stars in the field surrounding NGC 2355
based on the time-series photometric observation data. More than 3000 CCD
frames were obtained in the V band spread over 13 nights with the Nanshan
One-meter Wide-field Telescope. We have detected 88 variable stars, containing
72 new variable stars and 16 known variable stars. By analyzing these light
curves, we classified the variable stars as follows: 26 eclipsing binaries, 52
pulsating stars, 4 rotating variables, and 6 unclear type variable stars for
which their periods are much longer than the time baseline chosen. Employing
Gaia DR2 parallax, kinematics, and photometry, the cluster membership of these
variable stars were also analyzed for NGC 2355. In addition to the 11 variable
members reported by Cantat-Gaudin et al. (2018), we identify 4 more variable
member candidates located at the outer region of NGC 2355 and showed
homogeneity in space positions and kinematic properties with the cluster
members. The main physical parameters of NGC 2355 estimated from the two-color
and color-magnitude diagrams are log(age/yr) = 8.9, E(B - V) = 0.24 mag, and
[Fe/H] = - 0.07 dex.Comment: 15 pages, 11 figures. 6 tables,Accepted for publication in A
A Practical Simulation Flow for Singing Capacitor based Acoustic Noise Analysis
Multilayer ceramic capacitors (MLCCs) are widely used in modern electronics. Due to the piezoelectric effect of the ceramic material, however, MLCCs subjected to electrical noise may vibrate and generate acoustic noise, as \u27singing\u27. Acoustic noise can be annoying for users, especially within mobile devices, so it becomes important to perform acoustic noise analysis before a product is released. In this paper, a practical simulation flow for singing capacitor based acoustic noise is presented. The simulation flow and analysis method are developed on Ansys Sherlock and Mechanical. In Ansys Sherlock, local library and Approved Vendor List (AVL) files were used to build the model efficiently. After the PCB and all parts were set correctly, the model was imported to Ansys Mechanical for further modal analysis and harmonic analysis. Using the proposed simulation flow the simulation model could be easily created, and the inherent vibration properties and frequency response of the structure could be estimated
On Finding an Equivalent Force to Mimic the Multilayer Ceramic Capacitor Vibration
The Multilayer Ceramic Capacitor (MLCC) Can Vibrate Due to the Piezoelectric Effect When There is AC Noise on the Power Rail. the Vibration of the Capacitor Will Generate a Force on the PCB and Thus Cause the PCB Vibration and Audible Problems May Occur. the Work in This Paper Finds an Equivalent Force with Similar Behavior to the MLCC-Generated Force. the Force is Controllable and Knowable and Thus Can Mimic the Capacitor Vibration on the PCB
Effect of Gradually Decreasing Photoperiod on Immune Function in Siberian Hamsters
Animals usually use photoperiod as an important environmental cue to time the year. In terms of the winter immunocompetence enhancement hypothesis, animals in the non-tropical zone would actively enhance their immune function to decrease the negative influence of stressors such as low temperature and food shortage in winter. In the present study, we mimicked the transition from summer to winter by decreasing photoperiod gradually and examined the variations of immune repsonses in Siberian hamsters (Phodopus sungorus) to test this hypothesis. Twenty two female adult hamsters were randomly divided into the control (12h light: 12h dark, Control, n=11) and the gradually decreasing photoperiod group (Experiment, n=11). In the experiment group, day length was decreased from 12 h: 12 h light-dark cycle to 8 h: 16 h light-dark cycle at the pace of half an hour per week. We found that gradually decreasing photoperiod had no effect on body composition (wet carcass mass, subcutaneous, retroperitoneal, mesenteric and total body fat mass) and the masses of the organs detected such as brain, heart, liver and so on in hamsters. Similarly, immunological parameters including immune organs (thymus and spleen), white blood cells and serum bacteria killing capacity indicative of innate immunity were also not influenced by gradually decreasing photoperiod, which did not support the winter immunocompetence enhancement hypothesis. However, gradually decreasing photoperiod increased phytohaemagglutinin response post-24h of PHA challenge, which supported this hypothesis. There was no correlation between cellular, innate immunity and body fat mass, suggesting that body fat was not the reasons of the changes of cellular immunity. In summary, distinct components of immune system respond to gradually decreasing photoperiod differently in Siberian hamsters
Recommended from our members
Joint Effect of Multiple Common SNPs Predicts Melanoma Susceptibility
Single genetic variants discovered so far have been only weakly associated with melanoma. This study aims to use multiple single nucleotide polymorphisms (SNPs) jointly to obtain a larger genetic effect and to improve the predictive value of a conventional phenotypic model. We analyzed 11 SNPs that were associated with melanoma risk in previous studies and were genotyped in MD Anderson Cancer Center (MDACC) and Harvard Medical School investigations. Participants with ≥15 risk alleles were 5-fold more likely to have melanoma compared to those carrying ≤6. Compared to a model using the most significant single variant rs12913832, the increase in predictive value for the model using a polygenic risk score (PRS) comprised of 11 SNPs was 0.07(95% CI, 0.05-0.07). The overall predictive value of the PRS together with conventional phenotypic factors in the MDACC population was 0.69 (95% CI, 0.64-0.69). PRS significantly improved the risk prediction and reclassification in melanoma as compared with the conventional model. Our study suggests that a polygenic profile can improve the predictive value of an individual gene polymorphism and may be able to significantly improve the predictive value beyond conventional phenotypic melanoma risk factors
- …