The spectroscopic evolution of the symbiotic-like recurrent nova V407 Cygni during its 2010 outburst. I. The shock and its evolution

On 2010 Mar 10, V407 Cyg was discovered in outburst, eventually reaching V< 8 and detected by Fermi. Using medium and high resolution ground-based optical spectra, visual and Swift UV photometry, and Swift X-ray spectrophotometry, we describe the behavior of the high-velocity profile evolution for this nova during its first three months. The peak of the X-ray emission occurred at about day 40 with a broad maximum and decline after day 50. The main changes in the optical spectrum began at around that time. The He II 4686A line first appeared between days 7 and 14 and initially displayed a broad, symmetric profile that is characteristic of all species before day 60. Low-excitation lines remained comparatively narrow, with v(rad,max) of order 200-400 km/s. They were systematically more symmetric than lines such as [Ca V], [Fe VII], [Fe X], and He II, all of which showed a sequence of profile changes going from symmetric to a blue wing similar to that of the low ionization species but with a red wing extended to as high as 600 km/s . The Na I D doublet developed a broad component with similar velocity width to the other low-ionization species. The O VI Raman features were not detected. We interpret these variations as aspherical expansion of the ejecta within the Mira wind. The blue side is from the shock penetrating into the wind while the red wing is from the low-density periphery. The maximum radial velocities obey power laws, v(rad,max) t^{-n} with n ~ 1/3 for red wing and ~0.8 for the blue. (truncated)Comment: Accepted for publication, A&A (submitted: 9 Oct 2010; accepted: 1 Dec 2010) in press; based on data obtained with Swift, Nordic Optical Telescope, Ondrejov Observatory. Corrected typo, Fermi?LAT detection was at energies above 100 MeV (with thanks to C. C. Cheung

Minor stroke due to large artery occlusion. When is intravenous thrombolysis not enough? Results from the SITS International Stroke Thrombolysis Register

Purpose: Beyond intravenous thrombolysis, evidence is lacking on acute treatment of minor stroke caused by large artery occlusion. To identify candidates for additional endovascular therapy, we aimed to determine the frequency of non-haemorrhagic early neurological deterioration in patients with intravenous thrombolysis-treated minor stroke caused by occlusion of large proximal and distal cerebral arteries. Secondary aims were to establish risk factors for non-haemorrhagic early neurological deterioration and report three-month outcomes in patients with and without non-haemorrhagic early neurological deterioration. Method: We analysed data from the SITS International Stroke Thrombolysis Register on 2553 patients with intravenous thrombolysis-treated minor stroke (NIH Stroke Scale scores 0–5) and available arterial occlusion data. Non-haemorrhagic early neurological deterioration was defined as an increase in NIH Stroke Scale score ≥4 at 24 h, without parenchymal hematoma on follow-up imaging within 22–36 h. Findings: The highest frequency of non-haemorrhagic early neurological deterioration was seen in 30% of patients with terminal internal carotid artery or tandem occlusions (internal carotid artery + middle cerebral artery) (adjusted odds ratio: 10.3 (95% CI 4.3–24.9), p &#60; 0.001) and 17% in extracranial carotid occlusions (adjusted odds ratio 4.3 (2.5–7.7), p &#60; 0.001) versus 3.1% in those with no occlusion. Proximal middle cerebral artery-M1 occlusions had non-haemorrhagic early neurological deterioration in 9% (adjusted odds ratio 2.1 (0.97–4.4), p = 0.06). Among patients with any occlusion and non-haemorrhagic early neurological deterioration, 77% were dead or dependent at three months. Conclusions: Patients with minor stroke caused by internal carotid artery occlusion, with or without tandem middle cerebral artery involvement, are at high risk of disabling deterioration, despite intravenous thrombolysis treatment. Acute vessel imaging contributes usefully even in minor stroke to identify and consider endovascular treatment, or intensive monitoring at a comprehensive stroke centre, for patients at high risk of neurological deterioration

Are you suffering from a large arterial occlusion? Please raise your arm!

Background and purpose: Triage tools to identify candidates for thrombectomy are of utmost importance in acute stroke. No prognostic tool has yet gained any widespread use. We compared the predictive value of various models based on National Institutes of Health Stroke Scale (NIHSS) subitems, ranging from simple to more complex models, for predicting large artery occlusion (LAO) in anterior circulation stroke. Methods: Patients registered in the SITS international Stroke Register with available NIHSS and radiological arterial occlusion data were analysed. We compared 2042 patients harbouring an LAO with 2881 patients having no/distal occlusions. Using binary logistic regression, we developed models ranging from simple 1 NIHSS-subitem to full NIHSS-subitems models. Sensitivities and specificities of the models for predicting LAO were examined. Results: The model with highest predictive value included all NIHSS subitems for predicting LAO (area under the curve (AUC) 0.77), yielding a sensitivity and specificity of 69% and 76%, respectively. The second most predictive model (AUC 0.76) included 4-NIHSS-subitems (level of consciousness commands, gaze, facial and arm motor function) yielding a sensitivity and specificity of 67% and 75%, respectively. The simplest model included only deficits in arm motor-function (AUC 0.72) for predicting LAO, yielding a sensitivity and specificity of 67% and 72%, respectively. Conclusions: Although increasingly more complex models yield a higher discriminative performance for predicting LAO, differences between models are not large. Assessing grade of arm dysfunction along with an established stroke-diagnosis model may serve as a surrogate measure of arterial occlusion-status, thereby assisting in triage decisions

External Validation of the SEDAN Score for Prediction of Intracerebral Hemorrhage in Stroke Thrombolysis

Background and Purpose— The SEDAN score is a prediction rule for assessment of the risk of symptomatic intracerebral hemorrhage (SICH) per the European Cooperative Acute Stroke Study (ECASS) II definition in patients with acute ischemic stroke treated with intravenous thrombolysis. We assessed the performance of the score in predicting SICH per the ECASS II and Safe Implementation of Treatments in Stroke Monitoring Study (SITS-MOST) definitions in the SITS–International Stroke Thrombolysis Register (SITS-ISTR). Methods— We calculated the SEDAN score in 34 251 patients with complete data, enrolled into the SITS-ISTR. The risk for SICH by both definitions was calculated per score category. Odds ratios for SICH per point increase of the score were obtained using logistic regression. The predictive performance was assessed using area under the curve of the receiver operating characteristic (AUC-ROC). Results— The predictive capability for SICH per ECASS II was moderate at AUC-ROC=0.66. With rising scores, there was a moderate increase in risk for SICH per ECASS II (odds ratio, 1.65 per point; 95% confidence interval, 1.59–1.72; P <0.001), with SICH rates between 1.6% for 0 points and 16.9% for ≥5 points, average 5.1%. The predictive capability for SICH per SITS–MOST was weaker, AUC-ROC=0.60, with lower increase per score point (odds ratio, 1.36 per point; 95% confidence interval, 1.28–1.46; P <0.001), and SICH rates between 0.8% for 0 points and 5.4% for ≥5 points, average 1.8%. Conclusions— In this very large data set, the predictive and discriminatory performances of the SEDAN score were only moderate for SICH per ECASS II and low for SICH per SITS–Monitoring Study

The Advanced Spectral Library (ASTRAL): Reference Spectra for Evolved M Stars

The HST (Hubble Space Telescope) Treasury Program Advanced Spectral Library Project: Cool Stars was designed to collect representative, high-quality ultraviolet spectra of eight evolved F-M type cool stars. The Space Telescope Imaging Spectrograph (STIS) echelle spectra of these objects enable investigations of a broad range of topics, including stellar and interstellar astrophysics. This paper provides a guide to the spectra of the two evolved M stars, the M2 Iab super giant alpha Ori and the M3.4 giant gamma Cru, with comparisons to the prototypical K1.5 giant alpha Boo. It includes identifications of the significant atomic and molecular emission and absorption features and discusses the character of the photospheric and chromospheric continua and line spectra. The fluorescent processes responsible for a large portion of the emission-line spectrum, the characteristics of the stellar winds, and the available diagnostics for hot and cool plasmas are also summarized. This analysis will facilitate the future study of the spectra, outer atmospheres, and winds, not only of these objects but of numerous other cool, low-gravity stars, for years to come

Abundances and search for vertical stratification in the atmospheres of four HgMn stars

Using high resolution, high-S/N archival UVES spectra, we have performed a detailed spectroscopic analysis of 4 chemically peculiar HgMn stars (HD 71066, HD 175640, HD 178065 and HD 221507). Using spectrum synthesis, mean photospheric chemical abundances are derived for 22 ions of 16 elements. We find good agreement between our derived abundances and those published previously by other authors. For the 5 elements that present a sufficient number of suitable lines, we have attempted to detect vertical chemical stratification by analyzing the dependence of derived abundance as a function of optical depth. For most elements and most stars we find no evidence of chemical stratification with typical 3\sigma upper limits of \Delta\log N_elem/N_tot~0.1-0.2 dex per unit optical depth. However, for Mn in the atmosphere of HD 178065 we find convincing evidence of stratification. Modeling of the line profiles using a two-step model for the abundance of Mn yields a local abundance varying approximately linearly by ~0.7 dex through the optical depth range log \tau_5000=-3.6 to -2.8.Comment: 11 figures, 9 tables, table 6-9 (online material), accepted by MNRA

Improved overall survival after implementation of targeted therapy for patients with metastatic renal cell carcinoma: Results from the Danish Renal Cancer Group (DARENCA) study-2

AbstractAimTo evaluate the implementation of targeted therapy on overall survival (OS) in a complete national cohort of patients with metastatic renal cell carcinoma (mRCC).MethodsAll Danish patients with mRCC referred for first line treatment with immunotherapy, TKIs or mTOR-inhibitors between 2006 and 2010 were included. Baseline and outcome data were collected retrospectively. Prognostics factors were identified using log-rank tests and Cox proportional hazard model. Differences in distributions were tested with the Chi-square test.Results1049 patients were referred; 744 patients received first line treatment. From 2006 to 2010 we observed a significant increase in the number of referred patients; a significant increase in treated patients (64% versus 75%, P=0.0188); a significant increase in first line targeted therapy (22% versus 75%, P<0.0001); a significant increase in second line treatment (20% versus 40%, P=0.0104), a significant increased median OS (11.5 versus 17.2 months, P=0.0435) whereas survival for untreated patients remained unchanged. Multivariate analysis validated known prognostic factors. Moreover, treatment start years 2008 (HR 0.74, 95% CI, 0.55–0.99; P=0.0415), 2009 (HR 0.72, 95% CI, 0.54–0.96; P=0.0277) and 2010 (HR 0.63, 95% CI, 0.47–0.86; P=0.0035) compared to 2006, and more than two treatment lines received for patients with performance status 0–1 (HR 0.76, 95% CI, 0.58–0.99; P=0.0397) and performance status 2–3 (HR 0.19, 95% CI, 0.06–0.60; P=0.0051) were significantly associated with longer OS.ConclusionThis retrospective study documents that the implementation of targeted therapy has resulted in significantly improved treatment rates and overall survival in a complete national cohort of treated mRCC patients

Evaluation of an interactive, case-based review session in teaching medical microbiology

<p>Abstract</p> <p>Background</p> <p>Oklahoma State University-Center for Health Sciences (OSU-CHS) has replaced its microbiology wet laboratory with a variety of tutorials including a case-based interactive session called Microbial Jeopardy!. The question remains whether the time spent by students and faculty in the interactive case-based tutorial is worthwhile? This study was designed to address this question by analyzing both student performance data and assessing students' perceptions regarding the tutorial.</p> <p>Methods</p> <p>Both quantitative and qualitative data were used in the current study. Part One of the study involved assessing student performance using archival records of seven case-based exam questions used in the 2004, 2005, 2006, and 2007 OSU-CHS Medical Microbiology course. Two sample t-tests for proportions were used to test for significant differences related to tutorial usage. Part Two used both quantitative and qualitative means to assess student's perceptions of the Microbial Jeopardy! session. First, a retrospective survey was administered to students who were enrolled in Medical Microbiology in 2006 or 2007. Second, responses to open-ended items from the 2008 course evaluations were reviewed for comments regarding the Microbial Jeopardy! session.</p> <p>Results</p> <p>Both student performance and student perception data support continued use of the tutorials. Quantitative and qualitative data converge to suggest that students like and learn from the interactive, case-based session.</p> <p>Conclusion</p> <p>The case-based tutorial appears to improve student performance on case-based exam questions. Additionally, students perceived the tutorial as helpful in preparing for exam questions and reviewing the course material. The time commitment for use of the case-based tutorial appears to be justified.</p

The spectroscopic evolution of the symbiotic-like recurrent nova V407 Cygni during its 2010 outburst. II. The circumstellar environment and the aftermath

The nova outburst of V407 Cyg in 2010 Mar. 10 was the first observed for this star but its close resemblance to the well known symbiotic-like recurrent nova RS Oph suggests that it is also a member of this rare type of Galactic novae. The nova was the first detected at $\gamma$-ray energies and is the first known nova explosion for this system. The extensive multiwavelength coverage of this outburst makes it an ideal comparison with the few other outbursts known for similar systems. We extend our previous analysis of the Mira and the expanding shock from the explosion to detail the time development of the photoionized Mira wind, circumstellar medium, and shocked circumstellar environment to derive their physical parameters and how they relate to large scale structure of the environment, extending the previous coverage to more than 500 days after outburst. Absorption lines of Fe-peak ions formed in the Mira wind were visible as P Cyg profiles at low velocity before Day 69, around the time of the X-ray peak and we identified many absorption transitions without accompanying emission for metal lines. The H Balmer lines showed strong P Cyg absorption troughs that weakened during the 2010 observing period, through Day 128. We distinguish the components from the shock, the photoionized environment, and the chromosphere and inner Mira wind using spectra taken more than one year after outburst. The multiple shells and radiative excitation phenomenology are similar to those recently cited for GRBs and SNIa (severely truncated)Comment: accepted for publication in A&A (9/12/11