Description: Testing theories of hierarchical structure formation requires estimating the distribution of galaxy morphologies and its change with redshift. One aspect of this investigation involves identifying galaxies with disturbed morphologies (e.g. merging galaxies). This is often done by summarizing galaxy images using, e.g. the concentration, asymmetry and clumpiness and Gini- M 20 statistics of Conselice and Lotz et al., respectively, and associating particular statistic values with disturbance. We introduce three statistics that enhance detection of disturbed morphologies at high redshift ( z  ~ 2): the multimode ( M ), intensity ( I ) and deviation ( D ) statistics. We show their effectiveness by training a machine-learning classifier, random forest, using 1639 galaxies observed in the H band by the Hubble Space Telescope WFC3, galaxies that had been previously classified by eye by the Cosmic Assembly Near-IR Deep Extragalactic Legacy Survey collaboration. We find that the MID statistics (and the A statistic of Conselice) are the most useful for identifying disturbed morphologies. We also explore whether human annotators are useful for identifying disturbed morphologies. We demonstrate that they show limited ability to detect disturbance at high redshift, and that increasing their number beyond 10 does not provably yield better classification performance. We propose a simulation-based model-fitting algorithm that mitigates these issues by bypassing annotation.

Description: We have exploited the Hubble Space Telescope ( HST ) Cosmic Assembly Near-IR Deep Extragalactic Legacy Survey (CANDELS) J and H -band Wide Field Camera 3 (WFC3)/infrared (IR) imaging to study the properties of (sub-)millimetre galaxies within the Great Observatories Origins Deep Survey South (GOODS-South) field. After using the deep radio (Very Large Array 1.4 GHz) and Spitzer (Infrared Array Camera 8 μm) imaging to identify galaxy counterparts for the (sub-)millimetre sources, we have then utilized the new CANDELS WFC3/IR imaging in two ways. First, the addition of new deep near-IR photometry from both HST and (at K band) the VLT to the existing GOODS-South data base has enabled us to derive improved photometric redshifts and stellar masses, confirming that the (sub-)millimetre sources are massive (〈 M * 〉 = 2.2  x 10 11  ± 0.2 M ) galaxies at z ~= 1-3. Secondly, we have exploited the depth and resolution of the WFC3/IR imaging to determine the sizes and morphologies of the galaxies at rest-frame optical wavelengths rest  〉 4000 Å. Specifically, we have fitted two-dimensional axisymmetric galaxy models to the WFC3/IR images, varying luminosity, axial ratio, half-light radius r 1/2 and Sérsic index n . Crucially, the wavelength and depth of the WFC3/IR imaging enables modelling of the mass-dominant galaxy, rather than the blue high surface-brightness features which often dominate optical (rest-frame ultraviolet) images of (sub-)millimetre galaxies, and can confuse visual morphological classification. As a result of this analysis, we find that 〉95 per cent of the rest-frame optical light in almost all of the (sub-)millimetre galaxies is well described by either a single exponential disc ( n  ~= 1), or a multiple-component system in which the dominant constituent is disc like. We demonstrate that this conclusion is completely consistent with the results of recent high-quality ground-based K -band imaging sampling even longer rest-frame wavelengths, and explain why it is so. These massive disc galaxies are reasonably extended (〈 r 1/2 〉 = 4.5 ± 0.5 kpc; median r 1/2  = 4.0 kpc), consistent with the sizes of other massive star-forming discs at z  ~= 2. In many cases, we find evidence of blue clumps within the sources, with the mass-dominant disc component becoming more significant at longer wavelengths. Finally, only a minority of the sources show evidence for a major galaxy–galaxy interaction. Taken together, these results support the view that most (sub-)millimetre galaxies at z  ~= 2 are simply the most extreme examples of normal star-forming galaxies at that era. Interestingly, the only two bulge-dominated galaxies are also the two lowest redshift sources in the sample ( z  ~= 1), a result which may reflect the structural evolution of high-mass galaxies in general.

Description: Aims This study aimed to identify whether left atrial (LA) volume assessed by multidetector computed tomography (MDCT) is related to the long-term success of pulmonary vein ablation (PVA). MDCT is used to guide PVA for the treatment of atrial fibrillation (AF). MDCT permits accurate sizing of LA dimensions. Methods and results We analysed data from 368 ablation procedures of 279 consecutive patients referred for PVA due to drug-refractory symptomatic AF (age 62 ± 10; 58% men; 71% paroxysmal AF). Prior to the procedure, all patients underwent ECG-gated 64-MDCT scan for assessment of LA and PV anatomy, LA thrombus evaluation, LA volume estimation, and electroanatomical mapping integration. Within a mean follow-up of 356 ± 128 days, 64% of the patients maintained sinus rhythm after the initial ablation, and 84% when including repeat PVA. LA diameter ( P = 0.004), LA volume ( P = 0.002), and type of AF ( P = 0.001) were independent predictors of AF recurrence in univariate analysis. There was a relatively low correlation between the echocardiographic LA diameter and LA volume from MDCT ( P = 0.01, r = 0.5). In multivariate analysis, paroxysmal AF ( P 〈 0.006) and LA volume below the median value of 106 mL ( P = 0.042) were significantly associated with the success of PVA, whereas LA diameter was not ( P = 0.245). Analysing receiver-operator characteristics, the area under the curve for LA volume was 0.73 ( P = 0.001) compared with 0.60 ( P = 0.09) for LA diameter from echocardiography. Conclusion LA volume assessed by MDCT is a better predictor of AF recurrence after PVA than echocardiograpic LA diameter and can be derived from the pre-procedural imaging data set.

Description: Aims Multidetector computed tomography (MDCT) is frequently used to guide circumferential pulmonary vein ablation (PVA) for treatment of atrial fibrillation (AF) as it offers accurate visualization of the left atrial (LA) and pulmonary vein (PV) anatomy. This study aimed to identify if PV anatomy is associated with outcomes following PVA using remote magnetic navigation (RMN). Methods and results We analysed data from 138 consecutive patients and 146 ablation procedures referred for PVA due to drug-refractory symptomatic AF (age 63 ± 11 years; 57% men; 69% paroxysmal AF). The RMN using the stereotaxis system and open-irrigated 3.5 mm ablation catheters was used in all procedures. Prior to PVA, all patients underwent electrocardiogram-gated 64-MDCT for assessment of LA dimensions, PV anatomy, and electro-anatomical image integration during the procedure. Regular PV anatomy was found in 68%, a common left PV ostium was detected in 26%, and variant anatomy of the right PVs was detected in 6%. After a mean follow-up of 337 ± 102 days, 63% of the patients maintained sinus rhythm after the initial ablation, and 83% when including repeat PVA. Although acutely successful PV isolation did not differ between anatomical subgroups (regular 3.5 ± 0.8 vs. variant 3.2 ± 1.3; P = 0.31), AF recurrence was significantly higher in patients with non-regular PV anatomy ( P = 0.04, hazard ratio 1.72). Pulmonary vein anatomy did not influence complication rates. Conclusion Pulmonary vein anatomy assessed by MDCT is a good predictor of AF recurrence after PVA using RMN.

Description: Currently-proposed galaxy quenching mechanisms predict very different behaviours during major halo mergers, ranging from significant quenching enhancement (e.g. clump-induced gravitational heating models) to significant star formation enhancement (e.g. gas starvation models). To test real galaxies’ behaviour, we present an observational galaxy pair method for selecting galaxies whose host haloes are preferentially undergoing major mergers. Applying the method to central L * (10 10 M  〈  M *  〈 10 10.5 M ) galaxies in the Sloan Digital Sky Survey at z  〈 0.06, we find that major halo mergers can at most modestly reduce the star-forming fraction, from 59 to 47 per cent. Consistent with past research, however, mergers accompany enhanced specific star formation rates for star-forming L * centrals: ~10 per cent when a paired galaxy is within 200 kpc (approximately the host halo's virial radius), climbing to ~70 per cent when a paired galaxy is within 30 kpc. No evidence is seen for even extremely close pairs (〈30 kpc separation) rejuvenating star formation in quenched galaxies. For galaxy formation models, our results suggest: (1) quenching in L * galaxies likely begins due to decoupling of the galaxy from existing hot and cold gas reservoirs, rather than a lack of available gas or gravitational heating from infalling clumps, (2) state-of-the-art semi-analytic models currently overpredict the effect of major halo mergers on quenching, and (3) major halo mergers can trigger enhanced star formation in non-quenched central galaxies.

Description: We study how optical galaxy morphology depends on mass and star formation rate (SFR) in the Illustris Simulation. To do so, we measure automated galaxy structures in 10 808 simulated galaxies at z  = 0 with stellar masses 10 9.7  〈  M * /M  〈 10 12.3 . We add observational realism to idealized synthetic images and measure non-parametric statistics in rest-frame optical and near-IR images from four directions. We find that Illustris creates a morphologically diverse galaxy population, occupying the observed bulge strength locus and reproducing median morphology trends versus stellar mass, SFR, and compactness. Morphology correlates realistically with rotation, following classification schemes put forth by kinematic surveys. Type fractions as a function of environment agree roughly with data. These results imply that connections among mass, star formation, and galaxy structure arise naturally from models matching global star formation and halo occupation functions when simulated with accurate methods. This raises a question of how to construct experiments on galaxy surveys to better distinguish between models. We predict that at fixed halo mass near 10 12 M , disc-dominated galaxies have higher stellar mass than bulge-dominated ones, a possible consequence of the Illustris feedback model. While Illustris galaxies at M *  ~ 10 11 M have a reasonable size distribution, those at M *  ~ 10 10 M have half-light radii larger than observed by a factor of 2. Furthermore, at M *  ~ 10 10.5 –10 11 M , a relevant fraction of Illustris galaxies have distinct ‘ring-like’ features, such that the bright pixels have an unusually wide spatial extent.

Description: Background High-dose chemotherapy (HDCT) is an effective salvage treatment of germ-cell tumors (GCTs) patients. In the first salvage setting, 30%–70% of patients may achieve durable remissions. Even when HDCT is administered as subsequent salvage treatment, up to 20% of patients may still be definitively cured. However, patients with refractory/relapsed disease still have a very poor long-term prognosis, requiring earlier intervention of HDCT. Patients and methods This phase II trial was addressed to nonrefractory patients failing Cisplatin-based chemotherapy. Inclusion criteria included seminomatous GCT in relapse after two lines of chemotherapy, nonseminomatous GCT in relapse after first or second lines, partial remission after first line, primary mediastinal GCT in first relapse. Patients received two cycles combining Epirubicin and Paclitaxel (Epi-Tax), followed by three consecutive HDCT, one using a Paclitaxel/Thiotepa (Thio-Tax) association and two using the 5-day Ifosfamide–Carboplatin–Etoposide regimen. The main objective was to determine the complete response rate. Results Forty-five patients were included between September 2004 and December 2007: 44 received the first HDCT cycle, 39 two HDCT cycles, 29 could receive the whole protocol. Sixteen patients did not receive the entire protocol, including eight (17.7%) for toxic side-effects. Two patients (4.4%) died of toxicities, and 17 (37.7%) of disease progression. With a median follow-up time of 26 months (range, 4–51), the final overall response rate was 48.8% (including a complete response rate of 15.5% and a partial response/negative serum markers rate of 26.6%) in an intent-to-treat analysis. The median progression-free survival (PFS) and overall survival (OS) times were 22 months [95% confidence interval (CI) 2–not reached] and 32 months (95% CI 4–49), respectively. The 2-year PFS was a plateau setup at 50% (95% CI 32–67) and the 2-year OS was 66% (95% CI 44–81). Conclusion The TAXIF II protocol was effective in nonrefractory GCT patients failing Cisplatin-based chemotherapy. The toxic death rate remained acceptable in the field of HDCT regimens. Trial registration number NCT00231582.

Description: Background Inflammatory breast cancer (IBC) is a rare and aggressive disease requiring a multimodal treatment. We evaluated the benefit of adding docetaxel–5-fluorouracil (D-5FU) regimen after preoperative dose-intense (DI) epirubicin–cyclophosphamide (EC) and locoregional treatment in IBC patients. Patients and methods PEGASE 07 was a national randomized phase III open-label study involving 14 hospitals in France. Women with nonmetastatic IBC were eligible and randomly assigned to receive either four cycles of DI EC (E 150 mg/m 2 and C 4000 mg/m 2 every 3 weeks with repeated hematopoietic stem cell support), then mastectomy with axillary lymph node dissection, and radiotherapy (arm A) or the same treatment followed by four cycles of D-5FU (D 85 mg/m 2 , day 1 and 5FU 750 mg/m 2 /day continuous infusion, days 1–5 every 3 weeks) administered postradiotherapy (arm B). Patients with hormone receptor-positive tumors received hormonal therapy. Disease-free survival (DFS) was the primary end point. Secondary end points included tolerance, pathological complete response (pCR) rate, and overall survival (OS). Results Between January 2001 and May 2005, 174 patients were enrolled and treated (87 in each arm). Median follow-up was similar in both arms: 59.6 months [95% confidence interval (CI) 58.4–60.3] in arm A and 60.5 months (95% CI 58.3–61.4) in arm B. The estimated 5-year DFS rates were not different: 55% (95% CI 43.9–64.7) in arm A and 55.5% (95% CI 44.3–65.3) in arm B [hazard ratio (HR) = 0.94 (0.61–1.48); P = 0.81]. Identical results were observed for 5-year OS: 70.2% (95% CI 59.1–78.8) in arm A and 70% (95% CI 58.8–78.7) in arm B [HR = 0.93 (0.55–1.60); P = 0.814]. Following DI EC induction, in-breast and global (breast plus nodes) pCR were 28.9% and 20.1%, respectively. Estrogen receptor and pCR status were independently associated with survival. Conclusion The addition of D-5FU after preoperative DI EC and standard local therapy did not improve DFS in IBC. Clinical trial number ClinicalTrials.gov identifier: NCT02324088.

Description: Important but rare and subtle processes driving galaxy morphology and star formation may be missed by traditional spiral, elliptical, irregular or Sérsic bulge/disc classifications. To overcome this limitation, we use a principal component analysis (PCA) of non-parametric morphological indicators (concentration, asymmetry, Gini coefficient, M 20 , multimode, intensity and deviation) measured at rest-frame B band (corresponding to HST /WFC3 F 125 W at 1.4 〈 z 〈 2) to trace the natural distribution of massive (〉10 10 M ) galaxy morphologies. PCA quantifies the correlations between these morphological indicators and determines the relative importance of each. The first three principal components (PCs) capture ~75 per cent of the variance inherent to our sample. We interpret the first PC as bulge strength, the second PC as dominated by concentration and the third PC as dominated by asymmetry. Both PC1 and PC2 correlate with the visual appearance of a central bulge and predict galaxy quiescence. PC1 is a better predictor of quenching than stellar mass, as good as other structural indicators (Sérsic-n or compactness). We divide the PCA results into groups using an agglomerative hierarchical clustering method. Unlike Sérsic, this classification scheme separates compact galaxies from larger, smooth protoelliptical systems, and star-forming disc-dominated clumpy galaxies from star-forming bulge-dominated asymmetric galaxies. Distinguishing between these galaxy structural types in a quantitative manner is an important step towards understanding the connections between morphology, galaxy assembly and star formation.