Seasonally resolved ice core records from West Antarctica indicate a sea ice source of sea-salt aerosol and a biomass burning source of ammonium

Author Posting. © American Geophysical Union, 2014. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Journal of Geophysical Research: Atmospheres 119 (2014): 9168–9182, doi:10.1002/2013JD020720.The sources and transport pathways of aerosol species in Antarctica remain uncertain, partly due to limited seasonally resolved data from the harsh environment. Here, we examine the seasonal cycles of major ions in three high-accumulation West Antarctic ice cores for new information regarding the origin of aerosol species. A new method for continuous acidity measurement in ice cores is exploited to provide a comprehensive, charge-balance approach to assessing the major non-sea-salt (nss) species. The average nss-anion composition is 41% sulfate (SO42−), 36% nitrate (NO3−), 15% excess-chloride (ExCl−), and 8% methanesulfonic acid (MSA). Approximately 2% of the acid-anion content is neutralized by ammonium (NH4+), and the remainder is balanced by the acidity (Acy ≈ H+ − HCO3−). The annual cycle of NO3− shows a primary peak in summer and a secondary peak in late winter/spring that are consistent with previous air and snow studies in Antarctica. The origin of these peaks remains uncertain, however, and is an area of active research. A high correlation between NH4+ and black carbon (BC) suggests that a major source of NH4+ is midlatitude biomass burning rather than marine biomass decay, as previously assumed. The annual peak in excess chloride (ExCl−) coincides with the late-winter maximum in sea ice extent. Wintertime ExCl− is correlated with offshore sea ice concentrations and inversely correlated with temperature from nearby Byrd station. These observations suggest that the winter peak in ExCl− is an expression of fractionated sea-salt aerosol and that sea ice is therefore a major source of sea-salt aerosol in the region.This work was supported by grants from the NSF Antarctic Program (0632031 and 1142166), NSF-MRI (1126217), the NASA Cryosphere Program (NNX10AP09G), and by an award from the Department of Energy Office of Science Graduate Fellowship Program (DOE SCGF) to ASC.2015-01-2

Aromatase expression and outcomes in the P024 neoadjuvant endocrine therapy trial

Background Expression of aromatase by malignant breast epithelial cells and/or the surrounding stroma implies local estrogen production that could influence the outcome of endocrine therapy for breast cancer. Methods A validated immunohistochemical assay for aromatase was applied to samples from the P024 neoadjuvant endocrine therapy trial that compared tamoxifen and letrozole. The presence of aromatase expression by tumor or stromal cells was correlated with tumor response, treatment induced changes in proliferation index (Ki67), relapse-free survival (RFS) and breast cancer-specific survival (BCSS). Results Tumor and stromal aromatase expression were highly correlated (P = 0.0001). Tumor cell aromatase, as a semi-continuous score, also correlated with smaller tumor size at presentation (P = 0.01) higher baseline ER Allred score (P = 0.006) and lower Ki67 levels (P = 0.003). There was no significant relationship with clinical response or treatment-induced changes in Ki67. However, in a Cox multivariable model that incorporated a post-treatment tumor profile (pathological T stage, N stage, Ki67 and ER status of the surgical specimen), the presence of tumor aromatase expression at baseline sample remained a favorable independent prognostic biomarker for both RFS (P = 0.01, HR 2.3, 95% CI 1.2–4.6 for absent expression) and BCSS (P = 0.008, HR 3.76, 95% CI 1.4–10.0). Conclusions Autocrine estrogen synthesis may be most characteristic of smaller, more indolent and ER-rich breast cancers with lower baseline growth rates. However, response to endocrine treatment may not depend on whether the estrogenic stimulus has a local versus systemic source

Integrating evolution into ecological modelling: accommodating phenotypic changes in agent based models.

PMCID: PMC3733718This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.Evolutionary change is a characteristic of living organisms and forms one of the ways in which species adapt to changed conditions. However, most ecological models do not incorporate this ubiquitous phenomenon. We have developed a model that takes a 'phenotypic gambit' approach and focuses on changes in the frequency of phenotypes (which differ in timing of breeding and fecundity) within a population, using, as an example, seasonal breeding. Fitness per phenotype calculated as the individual's contribution to population growth on an annual basis coincide with the population dynamics per phenotype. Simplified model variants were explored to examine whether the complexity included in the model is justified. Outputs from the spatially implicit model underestimated the number of individuals across all phenotypes. When no phenotype transitions are included (i.e. offspring always inherit their parent's phenotype) numbers of all individuals are always underestimated. We conclude that by using a phenotypic gambit approach evolutionary dynamics can be incorporated into individual based models, and that all that is required is an understanding of the probability of offspring inheriting the parental phenotype

e-Consent in UK academic-led clinical trials : current practice, challenges, and the need for more evidence

Peer reviewe

Outcome prediction for estrogen receptor-positive breast cancer based on postneoadjuvant endocrine therapy tumor characteristics

BACKGROUND: Understanding how tumor response is related to relapse risk would help clinicians make decisions about additional treatment options for patients who have received neoadjuvant endocrine treatment for estrogen receptor–positive (ER+) breast cancer. METHODS: Tumors from 228 postmenopausal women with confirmed ER+ stage 2 and 3 breast cancers in the P024 neoadjuvant endocrine therapy trial, which compared letrozole and tamoxifen for 4 months before surgery, were analyzed for posttreatment ER status, Ki67 proliferation index, histological grade, pathological tumor size, node status, and treatment response. Cox proportional hazards were used to identify factors associated with relapse-free survival (RFS) and breast cancer–specific survival (BCSS) in 158 women. A preoperative endocrine prognostic index (PEPI) for RFS was developed from these data and validated in an independent study of 203 postmenopausal women in the IMPACT trial, which compared treatment with anastrozole, tamoxifen, or the combination 3 months before surgery. Statistical tests were two-sided. RESULTS: Median follow-up in P024 was 61.2 months. Patients with confirmed baseline ER+ clinical stage 2 and 3 tumors that were downstaged to stage 1 or 0 at surgery had 100% RFS (compared with higher stages, P < .001). Multivariable testing of posttreatment tumor characteristics revealed that pathological tumor size, node status, Ki67 level, and ER status were independently associated with both RFS and BCSS. The PEPI model based on these factors predicted RFS in the IMPACT trial (P = .002). CONCLUSIONS: Breast cancer patients with pathological stage 1 or 0 disease after neoadjuvant endocrine therapy and a low-risk biomarker profile in the surgical specimen (PEPI score 0) have an extremely low risk of relapse and are therefore unlikely to benefit from adjuvant chemotherapy

Outcome Prediction for Estrogen Receptor-Positive Breast Cancer Based on Postneoadjuvant Endocrine Therapy Tumor Characteristics

Background Understanding how tumor response is related to relapse risk would help clinicians make decisions about additional treatment options for patients who have received neoadjuvant endocrine treatment for estrogen receptor-positive (ER+) breast cancer. Methods Tumors from 228 postmenopausal women with confirmed ER+ stage 2 and 3 breast cancers in the P024 neoadjuvant endocrine therapy trial, which compared letrozole and tamoxifen for 4 months before surgery, were analyzed for posttreatment ER status, Ki67 proliferation index, histological grade, pathological tumor size, node status, and treatment response. Cox proportional hazards were used to identify factors associated with relapse-free survival (RFS) and breast cancer-specific survival (BCSS) in 158 women. A preoperative endocrine prognostic index (PEPI) for RFS was developed from these data and validated in an independent study of 203 postmenopausal women in the IMPACT trial, which compared treatment with anastrozole, tamoxifen, or the combination 3 months before surgery. Statistical tests were two-sided. Results Median follow-up in P024 was 61.2 months. Patients with confirmed baseline ER+ clinical stage 2 and 3 tumors that were downstaged to stage 1 or 0 at surgery had 100% RFS (compared with higher stages, P < .001). Multivariable testing of posttreatment tumor characteristics revealed that pathological tumor size, node status, Ki67 level, and ER status were independently associated with both RFS and BCSS. The PEPI model based on these factors predicted RFS in the IMPACT trial (P = .002). Conclusions Breast cancer patients with pathological stage 1 or 0 disease after neoadjuvant endocrine therapy and a low-risk biomarker profile in the surgical specimen (PEPI score 0) have an extremely low risk of relapse and are therefore unlikely to benefit from adjuvant chemotherap

The Structure of Episodic Memory: Ganeri's ‘Mental Time Travel and Attention’

We offer a framework for assessing what the structure of episodic memory might be, if one accepts the Buddhist denial of persisting selves. This paper is a response to Jonardon Ganeri's paper "Mental time travel and attention", which explores Buddhaghosa's ideas about memory. (It will eventually be published with a reply by Ganeri)

Deconvolution of Images from BLAST 2005: Insight into the K3-50 and IC 5146 Star-Forming Regions

We present an implementation of the iterative flux-conserving Lucy-Richardson (L-R) deconvolution method of image restoration for maps produced by the Balloon-borne Large Aperture Submillimeter Telescope (BLAST). We have analyzed its performance and convergence extensively through simulations and cross-correlations of the deconvolved images with available highresolution maps. We present new science results from two BLAST surveys, in the Galactic regions K3-50 and IC 5146, further demonstrating the benefits of performing this deconvolution. We have resolved three clumps within a radius of 4.'5 inside the star-forming molecular cloud containing K3-50. Combining the well-resolved dust emission map with available multi-wavelength data, we have constrained the Spectral Energy Distributions (SEDs) of five clumps to obtain masses (M), bolometric luminosities (L), and dust temperatures (T). The L-M diagram has been used as a diagnostic tool to estimate the evolutionary stages of the clumps. There are close relationships between dust continuum emission and both 21-cm radio continuum and 12CO molecular line emission. The restored extended large scale structures in the Northern Streamer of IC 5146 have a strong spatial correlation with both SCUBA and high resolution extinction images. A dust temperature of 12 K has been obtained for the central filament. We report physical properties of ten compact sources, including six associated protostars, by fitting SEDs to multi-wavelength data. All of these compact sources are still quite cold (typical temperature below ~ 16 K) and are above the critical Bonner-Ebert mass. They have associated low-power Young Stellar Objects (YSOs). Further evidence for starless clumps has also been found in the IC 5146 region.Comment: 13 pages, 12 Figures, 3 Table