SN 2010LP - A type IA supernova from a violent merger of two carbon-oxygen white dwarfs

SN 2010lp is a subluminous Type Ia supernova (SN Ia) with slowly evolving lightcurves. Moreover, it is the only subluminous SN Ia observed so far that shows narrow emission lines of [O I] in late-time spectra, indicating unburned oxygen close to the center of the ejecta. Most explosion models for SNe Ia cannot explain the narrow [O I] emission. Here, we present hydrodynamic explosion and radiative transfer calculations showing that the violent merger of two carbon-oxygen white dwarfs of 0.9 and 0.76 M adequately reproduces the early-time observables of SN 2010lp. Moreover, our model predicts oxygen close to the center of the explosion ejecta, a pre-requisite for narrow [O I] emission in nebular spectra as observed in SN 2010lp. © 2013. The American Astronomical Society. All rights reserved.

Early Medieval Settlement in North County Antrim: the significance of Doonmore and Drumadoon

The excavated north Antrim sites of Doonmore and Drumadoon are compared and attention is drawn to a group of like monuments in the same barony, here termed fortified outcrops. These are argued to be a type influenced by settlements in Argyll and introduced by the Dál Riata to Ulster through ‘counterstream migration’.

General practice-recorded depression and antidepressant use in young people with newly diagnosed Type 1 diabetes: a cohort study using the Clinical Practice Research Datalink

Aims - To investigate whether young people with Type 1 diabetes have an increased rate of depression andantidepressant use and whether their risk varies by age group, time from diabetes diagnosis, calendar period ofdiagnosis or complications status. Methods - A cohort of incident cases of patients with Type 1 diabetes diagnosed before 35 years of age (n = 5548) wasidentified within the Clinical Practice Research Datalink and individually age and sex matched with up to two controlsubjects without diabetes (n = 10 657). Patients with depression were identified through general practice-recordeddepression codes and antidepressant prescriptions. Cox regression models gave hazard ratios for depression in peoplewith Type 1 diabetes compared with control subjects. Results - People with Type 1 diabetes were twice as likely to have a record of antidepressant use and generalpractice-diagnosed depression as their matched control subjects (hazard ratio 2.08, 95% CI 1.73–2.50, P < 0.001).These associations varied by time from diagnosis, with marked increases observed within the first 5 years of diagnosis(hazard ratio 2.14, 95% CI 1.51–3.03, P < 0.001), and by age at diabetes diagnosis, with excesses noted even in the 10-to 19-year age group (hazard ratio 1.45, 95% CI 1.06–1.98, P = 0.02). Conclusions - This population-based study shows that people with Type 1 diabetes have higher rates of generalpractice-recorded depression and antidepressant use. The excess is present within 5 years of diabetes diagnosis,suggesting psychological input for patients is warranted in the early years of their condition.

Cadaveric fascia lata pubovaginal slings:early results on safety, efficacy and patient satisfaction

Objective To prospectively evaluate and quantify the efficacy of cadaveric fascia lata (CFL) as an allograft material in pubovaginal sling placement to treat stress urinary incontinence (SUI).

Patients and methods Thirty-one women with SUI (25 type II and six type III; mean age 63 years, range 40-75) had a CFL pubovaginal sling placed transvaginally. The operative time, blood loss, surgical complications and mean hospital stay were all documented. Before and at 4 months and 1 year after surgery each patient completed a 3-day voiding diary and validated voiding questionnaires (functional inquiry into voiding habits, Urogenital Distress Inventory and Incontinence Impact Questionnaire, including visual analogue scales).

Results The mean (range) operative time was 71 (50-120) min, blood loss 78.7 (20-250) mL and hospital stay 1.2 (1-2) days; there were no surgical complications. Over the mean follow-up of 13.5 months, complete resolution of SUI was reported by 29 (93%) patients. Overactive bladder symptoms were present in 23 (74%) patients before surgery, 21 (68%) at 4 months and two (6%) at 1 year; 80% of patients with low (<15 cmH (2) O) voiding pressures before surgery required self-catheterization afterward, as did 36% at 4 months, but only one (3%) at 1 year. Twenty-four (77%) patients needed to adopt specific postures to facilitate voiding. After surgery there was a significant reduction in daytime frequency, leakage episodes and pad use (P <0.05). The severity of leak and storage symptoms was also significantly less (P <0.002), whilst the severity of obstructive symptoms remained unchanged. Mean subjective levels of improvement were 69% at 4 months and 85% at 1 year, with corresponding objective satisfaction levels of 61% and 69%, respectively. At 1 year, approximate to 80% of the patients said they would undergo the procedure again and/or recommend it to a friend.

Conclusion Placing a pubovaginal sling of CFL allograft is a highly effective, safe surgical approach for resolving SUI, with a short operative time and rapid recovery. Storage symptoms are significantly improved, and subjective improvement and satisfaction rates are high.

Possible binary progenitors for the Type Ib supernova iPTF13bvn

Cao et al. reported a possible progenitor detection for the Type Ib supernovae iPTF13bvn for the first time. We find that the progenitor is in fact brighter than the magnitudes previously reported by approximately 0.7-0.2 mag with a larger error in the bluer filters. We compare our new magnitudes to our large set of binary evolution models and find that many binary models with initial masses in the range of 10-20M(circle dot) match this new photometry and other constraints suggested from analysing the supernova. In addition, these lower mass stars retain more helium at the end of the model evolution indicating that they are likely to be observed as Type Ib supernovae rather than their more massive, Wolf-Rayet counter parts. We are able to rule out typical Wolf-Rayet models as the progenitor because their ejecta masses are too high and they do not fit the observed SED unless they have a massive companion which is the observed source at the supernova location. Therefore only late-time observations of the location will truly confirm if the progenitor was a helium giant and not a Wolf-Rayet star.

Supersolar Ni/Fe production in the Type IIP SN 2012ec

SN 2012ec is a Type IIP supernova (SN) with a progenitor detection and comprehensive photospheric phase observational coverage. Here, we present Very Large Telescope and Public ESO Spectroscopic Survey of Transient Objects observations of this SN in the nebular phase. We model the nebular [O I] lambda lambda 6300, 6364 lines and find their strength to suggest a progenitor main-sequence mass of 13-15 M-circle dot. SN2012ec is unique among hydrogen-rich SNe in showing a distinct line of stable nickel [Ni II] lambda 7378. This line is produced by Ni-58, a nuclear burning ash whose abundance is a sensitive tracer of explosive burning conditions. Using spectral synthesis modelling, we use the relative strengths of [Ni II] lambda 7378 and [Fe II] lambda 7155 (the progenitor of which is Ni-56) to derive a Ni/Fe production ratio of 0.20 +/- 0.07 (by mass), which is a factor 3.4 +/- 1.2 times the solar value. High production of stable nickel is confirmed by a strong [Ni II] 1.939 mu m line. This is the third reported case of a core-collapse SN producing a Ni/Fe ratio far above the solar value, which has implications for core-collapse explosion theory and galactic chemical evolution models.

Observational Constraints on the Progenitors of Core-Collapse Supernovae: The Case for Missing High-Mass Stars

Over the last 15 years, the supernova community has endeavoured to directly identify progenitor stars for core-collapse supernovae discovered in nearby galaxies. These precursors are often visible as resolved stars in high-resolution images from space-and ground-based telescopes. The discovery rate of progenitor stars is limited by the local supernova rate and the availability and depth of archive images of galaxies, with 18 detections of precursor objects and 27 upper limits. This review compiles these results (from 1999 to 2013) in a distance-limited sample and discusses the implications of the findings. The vast majority of the detections of progenitor stars are of type II-P, II-L, or IIb with one type Ib progenitor system detected and many more upper limits for progenitors of Ibc supernovae (14 in all). The data for these 45 supernovae progenitors illustrate a remarkable deficit of high-luminosity stars above an apparent limit of log L/L-circle dot similar or equal to 5.1 dex. For a typical Salpeter initial mass function, one would expect to have found 13 high-luminosity and high-mass progenitors by now. There is, possibly, only one object in this time-and volume-limited sample that is unambiguously high-mass (the progenitor of SN2009ip) although the nature of that supernovae is still debated. The possible biases due to the influence of circumstellar dust, the luminosity analysis, and sample selection methods are reviewed. It does not appear likely that these can explain the missing high-mass progenitor stars. This review concludes that the community's work to date shows that the observed populations of supernovae in the local Universe are not, on the whole, produced by high-mass (M greater than or similar to 18 M-circle dot) stars. Theoretical explosions of model stars also predict that black hole formation and failed supernovae tend to occur above an initial mass of M similar or equal to 18 M-circle dot. The models also suggest there is no simple single mass division for neutron star or black-hole formation and that there are islands of explodability for stars in the 8-120 M-circle dot range. The observational constraints are quite consistent with the bulk of stars above M similar or equal to 18 M-circle dot collapsing to form black holes with no visible supernovae.

Type 2 diabetes: a case study

Increased prevalence of diabetes in the community has been accompanied by an increase in diabetes in hospitalised patients. About a quarter of these patients experience a hypoglycaemic episode during their admission, which is associated with increased risk of mortality and length of stay. This article examines the aetiology, pathophysiology, diagnosis and treatment of type 2 diabetes using a case study approach. The psychosocial implications for the patient are also discussed. The case study is based on a patient with diabetes who was admitted to hospital following a hypoglycaemic episode and cared for during a practice placement. The importance of early diagnosis of diabetes and the adverse effects of delayed diagnosis are discussed.

Time and Cell Type Dependency of Survival Responses in Co-cultured Tumor and Fibroblast Cells after Exposure to Modulated Radiation Fields

Advanced radiotherapy techniques such as intensity-modulated radiation therapy (IMRT) achieve high levels of conformity to the target volume through the sequential delivery of highly spatially and temporally modulated radiation fields, which have been shown to impact radiobiological response. This study aimed to characterize the time and cell type dependency of survival responses to modulated fields using single cell type (SCT) and mixed cell type (MCT) co-culture models of transformed fibroblast (AG0-1522b) cells, and prostate (DU-145) and lung (H460) cancer cells. In SCT cultures, in-field responses showed no significant time dependency while out-of-field responses occurred early, and plateaued 6 h after irradiation in both DU-145 and H460 cells. Under modulated beam configurations MCT co-cultures showed cell-specific, differential out-of-field responses depending on the irradiated in-field and responding out-of-field cell type. The observed differential out-of-field responses may be due to the genetic background of the cells, in particular p53 status, which has been shown to mediate radiation-induced bystander effects (RIBEs). These data provide further insight into the radiobiological parameters that influence out-of-field responses, which have potential implications for advanced radiotherapy modalities and may provide opportunities for biophysical optimization in radiotherapy treatment planning.

SN 2009ib: a Type II-P supernova with an unusually long plateau

We present optical and near-infrared photometry and spectroscopy of SN 2009ib, a Type II-P supernova in NGC 1559. This object has moderate brightness, similar to those of the intermediate-luminosity SNe 2008in and 2009N. Its plateau phase is unusually long, lasting for about 130 d after explosion. The spectra are similar to those of the subluminous SN 2002gd, with moderate expansion velocities. We estimate the Ni-56 mass produced as 0.046 +/- A 0.015 M-aS (TM). We determine the distance to SN 2009ib using both the expanding photosphere method (EPM) and the standard candle method. We also apply EPM to SN 1986L, a Type II-P SN that exploded in the same galaxy. Combining the results of different methods, we conclude the distance to NGC 1559 as D = 19.8 +/- A 3.0 Mpc. We examine archival, pre-explosion images of the field taken with the Hubble Space Telescope, and find a faint source at the position of the SN, which has a yellow colour [(V - I)(0) = 0.85 mag]. Assuming it is a single star, we estimate its initial mass as M-ZAMS = 20 M-aS (TM). We also examine the possibility, that instead of the yellow source the progenitor of SN 2009ib is a red supergiant star too faint to be detected. In this case, we estimate the upper limit for the initial zero-age main sequence (ZAMS) mass of the progenitor to be similar to 14-17 M-aS (TM). In addition, we infer the physical properties of the progenitor at the explosion via hydrodynamical modelling of the observables, and estimate the total energy as similar to 0.55 x 10(51) erg, the pre-explosion radius as similar to 400 R-aS (TM), and the ejected envelope mass as similar to 15 M-aS (TM), which implies that the mass of the progenitor before explosion was similar to 16.5-17 M-aS (TM).

Deflagrations in hybrid CONe white dwarfs: a route to explain the faint Type Iax supernova 2008ha

Stellar evolution models predict the existence of hybrid white dwarfs (WDs) with a carbon-oxygen core surrounded by an oxygen-neon mantle. Being born with masses similar to 1.1 M-aS (TM), hybrid WDs in a binary system may easily approach the Chandrasekhar mass (M-Ch) by accretion and give rise to a thermonuclear explosion. Here, we investigate an off-centre deflagration in a near-M-Ch hybrid WD under the assumption that nuclear burning only occurs in carbon-rich material. Performing hydrodynamics simulations of the explosion and detailed nucleosynthesis post-processing calculations, we find that only 0.014 M-aS (TM) of material is ejected while the remainder of the mass stays bound. The ejecta consist predominantly of iron-group elements, O, C, Si and S. We also calculate synthetic observables for our model and find reasonable agreement with the faint Type Iax SN 2008ha. This shows for the first time that deflagrations in near-M-Ch WDs can in principle explain the observed diversity of Type Iax supernovae. Leaving behind a near-M-Ch bound remnant opens the possibility for recurrent explosions or a subsequent accretion-induced collapse in faint Type Iax SNe, if further accretion episodes occur. From binary population synthesis calculations, we find the rate of hybrid WDs approaching M-Ch to be of the order of 1 per cent of the Galactic SN Ia rate.

Late-time spectral line formation in Type IIb supernovae, with application to SN 1993J, SN 2008ax, and SN 2011dh

We investigate line formation processes in Type IIb supernovae (SNe) from 100 to 500 days post-explosion using spectral synthesis calculations. The modelling identifies the nuclear burning layers and physical mechanisms that produce the major emission lines, and the diagnostic potential of these. We compare the model calculations with data on the three best observed Type IIb SNe to-date - SN 1993J, SN 2008ax, and SN 2011dh. Oxygen nucleosynthesis depends sensitively on the main-sequence mass of the star and modelling of the [O I] lambda lambda 6300, 6364 lines constrains the progenitors of these three SNe to the M-ZAMS = 12-16 M-circle dot range (ejected oxygen masses 0.3-0.9 M-circle dot), with SN 2011dh towards the lower end and SN 1993J towards the upper end of the range. The high ejecta masses from M-ZAMS greater than or similar to 17 M-circle dot progenitors give rise to brighter nebular phase emission lines than observed. Nucleosynthesis analysis thus supports a scenario of low-to-moderate mass progenitors for Type IIb SNe, and by implication an origin in binary systems. We demonstrate how oxygen and magnesium recombination lines may be combined to diagnose the magnesium mass in the SN ejecta. For SN 2011dh, a magnesium mass of 0.02-0.14 M-circle dot is derived, which gives a Mg/O production ratio consistent with the solar value. Nitrogen left in the He envelope from CNO burning gives strong [N II] lambda lambda 6548, 6583 emission lines that dominate over Ha emission in our models. The hydrogen envelopes of Type IIb SNe are too small and dilute to produce any noticeable H alpha emission or absorption after similar to 150 days, and nebular phase emission seen around 6550 angstrom is in many cases likely caused by [N II] lambda lambda 6548, 6583. Finally, the influence of radiative transport on the emergent line profiles is investigated. Significant line blocking in the metal core remains for several hundred days, which affects the emergent spectrum. These radiative transfer effects lead to early-time blueshifts of the emission line peaks, which gradually disappear as the optical depths decrease with time. The modelled evolution of this effect matches the observed evolution in SN 2011dh.

Developmentally regulated IL6-type cytokines signal to germ cells in the human fetal ovary

Fetal ovarian development and primordial follicle formation are imperative for adult fertility in the female. Data suggest the interleukin (IL)6-type cytokines, leukaemia inhibitory factor (LIF), IL6, oncostatin M (OSM) and ciliary neurotrophic factor (CNTF), are able to regulate the survival, proliferation and differentiation of fetal murine germ cells (GCs) in vivo and in vitro. We postulated that these factors may play a similar role during early human GC development and primordial follicle formation. To test this hypothesis, we have investigated the expression and regulation of IL6-type cytokines, using quantitative reverse transcription polymerase chain reaction and immunohistochemistry. Expression of transcripts encoding OSM increased significantly across the gestational range examined (8-20 weeks), while expression of IL6 increased specifically between the first (8-11 weeks) and early second (12-16 weeks) trimesters, co-incident with the initiation of meiosis. LIF and CNTF expression remained unchanged. Expression of the genes encoding the LIF and IL6 receptors, and their common signalling subunit gp130, was also found to be developmentally regulated, with expression increasing significantly with increasing gestation. LIF receptor and gp130 proteins localized exclusively to GCs, including oocytes in primordial follicles, indicating this cell type to be the sole target of IL6-type cytokine signalling in the human fetal ovary. These data establish that IL6-type cytokines and their receptors are expressed in the human fetal ovary and may directly influence GC development at multiple stages of maturation.

Cosmological Constraints from Measurements of Type Ia Supernovae Discovered During the First 1.5 Yr of the Pan-STARRS1 Survey

We present griz_P1 light curves of 146 spectroscopically confirmed Type Ia supernovae (SNe Ia; 0.03 < z < 0.65) discovered during the first 1.5 yr of the Pan-STARRS1 Medium Deep Survey. The Pan-STARRS1 natural photometric system is determined by a combination of on-site measurements of the instrument response function and observations of spectrophotometric standard stars. We find that the systematic uncertainties in the photometric system are currently 1.2% without accounting for the uncertainty in the Hubble Space Telescope Calspec definition of the AB system. A Hubble diagram is constructed with a subset of 113 out of 146 SNe Ia that pass our light curve quality cuts. The cosmological fit to 310 SNe Ia (113 PS1 SNe Ia + 222 light curves from 197 low-z SNe Ia), using only supernovae (SNe) and assuming a constant dark energy equation of state and flatness, yields w = -1.120^+0.360_-0.206(Stat)^+0.269_0.291(Sys). When combined with BAO+CMB(Planck)+H₀, the analysis yields Ω_M = 0.280^+0.013_0.012 and w = -1.166^+0.072_-0.069 including all identified systematics. The value of w is inconsistent with the cosmological constant value of -1 at the 2.3σ level. Tension endures after removing either the baryon acoustic oscillation (BAO) or the H₀ constraint, though it is strongest when including the H₀ constraint. If we include WMAP9 cosmic microwave background (CMB) constraints instead of those from Planck, we find w = -1.124^+0.083_-0.065, which diminishes the discord to <2σ. We cannot conclude whether the tension with flat ΛCDM is a feature of dark energy, new physics, or a combination of chance and systematic errors. The full Pan-STARRS1 SN sample with ∼three times as many SNe should provide more conclusive results.

The first month of evolution of the slow-rising Type IIP SN 2013ej in M74

We present early photometric and spectroscopic observations of SN 2013ej, a bright Type IIP supernova (SN) in M74. SN 2013ej is one of the closest SNe ever discovered. The available archive images and the early discovery help to constrain the nature of its progenitor. The earliest detection of this explosion was on 2013 July 24.125 UT and our spectroscopic monitoring with the FLOYDS spectrographs began on July 27.7 UT, continuing almost daily for two weeks. Daily optical photometric monitoringwas achieved with the 1mtelescopes of the Las Cumbres Observatory Global Telescope (LCOGT) network, and was complemented by UV data from Swift and near-infrared spectra from Public ESO Spectroscopic Survey of Transient Objects and Infrared Telescope Facility. The data from our monitoring campaign show that SN 2013ej experienced a 10 d rise before entering into a well-defined plateau phase. This unusually long rise time for a Type IIP has been seen previously in SN 2006bp and SN 2009bw. A relatively rare strong absorption blueward of Hα is present since our earliest spectrum. We identify this feature as Si II, rather than high-velocity Hα as sometimes reported in the literature.