Testing Evolutionary Models of Dwarf Irregular Galaxies through Gas and Stellar Metallicity Determinations in HII Galaxies

Dwarf irregular galaxies are usually low-metallicity objects, and show ongoing or very recent star formation, giving rise to their irregular appearance. Especially HII galaxies, a sub-category of dwarf irregulars showing unusually high star formation activity, are believed to be among the least evolved galaxies in existence today. Therefore, they are very interesting objects for studies of early galaxy evolution and of metallicity enrichment mechanisms. Several groups have developed theoretical evolutionary models of galaxies of this type, describing different possible formation and evolutionary scenarii, and varying factors such as gas infall and outflow, as well as the star formation history, and making predictions about their chemical evolution. One way to evaluate these models is by determining the metallicities of the different components of these galaxies, their gas and stars. We examine a sample of HII galaxies from the Sloan Digital Sky Survey, which possibly contains the largest homogeneous sample of HII galaxy spectra to date. Using very restrictive selection criteria, which guarantee a sample of high quality spectra and avoid "contamination” by spectra of objects of other nature, we defined a sample of ∼ 700 HII galaxies spectra. Through emission line strength calibrations and a detailed stellar population synthesis, we determined the metallicities of both the gas and the stellar content of these galaxies. For HII galaxies up to stellar masses of 5 × 109 M ⊙, we find enrichment mechanisms not to vary with galactic mass, being the same for low- and high-mass galaxies on average. They do seem to present a greater variety at the high-mass end, though, indicating a more complex assembly history. Our results favour galaxy evolutionary models featuring constantly infalling low-metallicity clouds that retain part of the galactic winds. Above 5 × 109 M ⊙ stellar mass, the retention of high metallicity gas by the galaxies' gravitational potential dominates. I would like to thank the Fundação de Amparo à Pesquisa do Estado do São Paulo (FAPESP) for financial suppor

Associations of HLA-A, -B and-DRB1 Types with Oral Diseases in Swiss Adults

Peer reviewe

Midregional pro-Adrenomedullin in addition to b-type natriuretic peptides in the risk stratification of patients with acute dyspnea: an observational study

The identification of patients at highest risk for adverse outcome who are presenting with acute dyspnea to the emergency department remains a challenge. This study investigates the prognostic value of the newly described midregional fragment of the pro-Adrenomedullin molecule (MR-proADM) alone and combined to B-type natriuretic peptide (BNP) or N-terminal proBNP (NT-proBNP) in patients with acute dyspnea.; We conducted a prospective, observational cohort study in the emergency department of a University Hospital and enrolled 287 unselected, consecutive patients (48% women, median age 77 (range 68 to 83) years) with acute dyspnea.; MR-proADM levels were elevated in non-survivors (n = 77) compared to survivors (median 1.9 (1.2 to 3.2) nmol/L vs. 1.1 (0.8 to 1.6) nmol/L; P > 0.001). The areas under the receiver operating characteristic curve (AUC) to predict 30-day mortality were 0.81 (95% CI 0.73 to 0.90), 0.76 (95% CI 0.67 to 0.84) and 0.63 (95% CI 0.53 to 0.74) for MR-proADM, NT-proBNP and BNP, respectively (MRproADM vs. NTproBNP P = 0.38; MRproADM vs. BNP P = 0.009). For one-year mortality the AUC were 0.75 (95% CI 0.69 to 0.81), 0.75 (95% CI 0.68 to 0.81), 0.69 (95% CI 0.62 to 0.76) for MR-proADM, NT-proBNP and BNP, respectively without any significant difference. Using multivariate linear regression analysis, MR-proADM strongly predicted one-year all-cause mortality independently of NT-proBNP and BNP levels (OR = 10.46 (1.36 to 80.50), P = 0.02 and OR = 24.86 (3.87 to 159.80) P = 0.001, respectively). Using quartile approaches, Kaplan-Meier curve analyses demonstrated a stepwise increase in one-year all-cause mortality with increasing plasma levels (P > 0.0001). Combined levels of MR-proADM and NT-proBNP did risk stratify acute dyspneic patients into a low (90% one-year survival rate), intermediate (72 to 82% one-year survival rate) or high risk group (52% one-year survival rate).; MR-proADM alone or combined to NT-proBNP has a potential to assist clinicians in risk stratifying patients presenting with acute dyspnea regardless of the underlying disease

Multicenter Validation of Histopathologic Tumor Regression Grade After Neoadjuvant Chemotherapy in Muscle-Invasive Bladder Carcinoma

Response classification after neoadjuvant chemotherapy in muscle-invasive bladder carcinoma is based on the TNM stage at radical cystectomy. We recently showed that histopathologic tumor regression grades (TRGs) add prognostic information to TNM. Our aim was to validate the prognostic significance of TRG in muscle-invasive bladder cancer in a multicenter setting. We enrolled 389 patients who underwent cisplatin-based chemotherapy before radical cystectomy in 8 centers between 2010 and 2016. Median follow-up was 2.2 years. TRG was determined in radical cystectomy specimens by local pathologists. Central pathology review was conducted in 20% of cases, which were randomly selected. The major response was defined as ≤pT1N0. The remaining patients were grouped into partial responders (≥ypT2N0-3 and TRG 2) and nonresponders (≥ypT2N0-3 and TRG 3). TRG was successfully determined in all cases, and interobserver agreement in central pathology review was high (κ=0.83). After combining TRG and TNM, 47%, 15%, and 38% of patients were major, partial, and nonresponders, respectively. Combination of TRG and TNM showed significant prognostic discrimination of overall survival (major responder: reference; partial responder: hazard ratio 3.5 [95% confidence interval: 1.8-6.8]; nonresponder: hazard ratio 6.1 [95% confidence interval: 3.6-10.3]). This discrimination was superior compared with TNM staging alone, supported by 2 goodness-of-fit criteria (P=0.041). TRG is a simple, reproducible histopathologic measurement of response to neoadjuvant chemotherapy in muscle-invasive bladder cancer. Integrating TRG with TNM staging resulted in significantly better prognostic stratification than TNM staging alone

Deception and Self-Deception

Why are people so often overconfident? We conduct an experiment to test the hypothesis that people become overconfident to more effectively persuade or deceive others. After performing a cognitively challenging task, half of our subjects are informed that they can earn money by convincing others of their superior performance. The privately elicited beliefs of informed subjects are significantly more confident than the beliefs of subjects in the control condition. By generating exogenous variation in confidence with a noisy performance signal, we are also able to show that higher confidence indeed makes subjects more persuasive in the subsequent face-to-face interactions