Morphological evolution and galactic sizes in the L-Galaxies SA model

In this work we update theL-Galaxiessemi-analytic model (SAM) to better follow thephysical processes responsible for the growth of bulges via disc instabilities (leading to pseudo-bulges) and mergers (leading to classical bulges). We address the former by considering thecontribution of both stellar and gaseous discs in the stability of the galaxy, and we update thelatter by including dissipation of energy in gas-rich mergers. Furthermore, we introduce angularmomentum losses during cooling and find that an accurate match to the observed correlationbetween stellar disc scale length and mass atz∼0.0requires that the gas loses 20%of its initialspecific angular momentum to the corresponding dark matter halo during the formation of thecold gas disc. We reproduce the observed trends between the stellar mass and specific angularmomentum for both disc- and bulge-dominated galaxies, with the former rotating faster thanthe latter of the same mass. We conclude that a two-component instability recipe provides amorphologically diverse galaxy sample which matches the observed fractional breakdown ofgalaxies into different morphological types. This recipe also enables us to obtain an excellent fitto the morphology-mass relation and stellar mass function of different galactic types. Finally, we find that energy dissipation during mergers reduces the merger remnant sizes and allowsus to match the observed mass-size relation for bulge-dominated system

The challenge of simulating the star cluster population of dwarf galaxies with resolved interstellar medium

We present results on the star cluster properties from a series of high resolution smoothed particles hydrodynamics (SPH) simulations of isolated dwarf galaxies as part of the GRIFFIN project. The simulations at sub-parsec spatial resolution and a minimum particle mass of 4 M-circle dot incorporate non-equilibrium heating, cooling, and chemistry processes, and realize individual massive stars. The simulations follow feedback channels of massive stars that include the interstellar-radiation field variable in space and time, the radiation input by photo-ionization and supernova explosions. Varying the star formation efficiency per free-fall time in the range epsilon(ff) = 0.2-50 per cent neither changes the star formation rates nor the outflow rates. While the environmental densities at star formation change significantly with epsilon(ff), the ambient densities of supernovae are independent of epsilon(ff) indicating a decoupling of the two processes. At low epsilon(ff), gas is allowed to collapse more before star formation, resulting in more massive, and increasingly more bound star clusters are formed, which are typically not destroyed. With increasing epsilon(ff), there is a trend for shallower cluster mass functions and the cluster formation efficiency Gamma for young bound clusters decreases from 50 per cent to similar to 1 per cent showing evidence for cluster disruption. However, none of our simulations form low mass (Peer reviewe

BHPR research: qualitative1. Complex reasoning determines patients' perception of outcome following foot surgery in rheumatoid arhtritis

Background: Foot surgery is common in patients with RA but research into surgical outcomes is limited and conceptually flawed as current outcome measures lack face validity: to date no one has asked patients what is important to them. This study aimed to determine which factors are important to patients when evaluating the success of foot surgery in RA Methods: Semi structured interviews of RA patients who had undergone foot surgery were conducted and transcribed verbatim. Thematic analysis of interviews was conducted to explore issues that were important to patients. Results: 11 RA patients (9 ♂, mean age 59, dis dur = 22yrs, mean of 3 yrs post op) with mixed experiences of foot surgery were interviewed. Patients interpreted outcome in respect to a multitude of factors, frequently positive change in one aspect contrasted with negative opinions about another. Overall, four major themes emerged. Function: Functional ability & participation in valued activities were very important to patients. Walking ability was a key concern but patients interpreted levels of activity in light of other aspects of their disease, reflecting on change in functional ability more than overall level. Positive feelings of improved mobility were often moderated by negative self perception ("I mean, I still walk like a waddling duck”). Appearance: Appearance was important to almost all patients but perhaps the most complex theme of all. Physical appearance, foot shape, and footwear were closely interlinked, yet patients saw these as distinct separate concepts. Patients need to legitimize these feelings was clear and they frequently entered into a defensive repertoire ("it's not cosmetic surgery; it's something that's more important than that, you know?”). Clinician opinion: Surgeons' post operative evaluation of the procedure was very influential. The impact of this appraisal continued to affect patients' lasting impression irrespective of how the outcome compared to their initial goals ("when he'd done it ... he said that hasn't worked as good as he'd wanted to ... but the pain has gone”). Pain: Whilst pain was important to almost all patients, it appeared to be less important than the other themes. Pain was predominately raised when it influenced other themes, such as function; many still felt the need to legitimize their foot pain in order for health professionals to take it seriously ("in the end I went to my GP because it had happened a few times and I went to an orthopaedic surgeon who was quite dismissive of it, it was like what are you complaining about”). Conclusions: Patients interpret the outcome of foot surgery using a multitude of interrelated factors, particularly functional ability, appearance and surgeons' appraisal of the procedure. While pain was often noted, this appeared less important than other factors in the overall outcome of the surgery. Future research into foot surgery should incorporate the complexity of how patients determine their outcome Disclosure statement: All authors have declared no conflicts of interes

Effects of Anacetrapib in Patients with Atherosclerotic Vascular Disease

BACKGROUND: Patients with atherosclerotic vascular disease remain at high risk for cardiovascular events despite effective statin-based treatment of low-density lipoprotein (LDL) cholesterol levels. The inhibition of cholesteryl ester transfer protein (CETP) by anacetrapib reduces LDL cholesterol levels and increases high-density lipoprotein (HDL) cholesterol levels. However, trials of other CETP inhibitors have shown neutral or adverse effects on cardiovascular outcomes. METHODS: We conducted a randomized, double-blind, placebo-controlled trial involving 30,449 adults with atherosclerotic vascular disease who were receiving intensive atorvastatin therapy and who had a mean LDL cholesterol level of 61 mg per deciliter (1.58 mmol per liter), a mean non-HDL cholesterol level of 92 mg per deciliter (2.38 mmol per liter), and a mean HDL cholesterol level of 40 mg per deciliter (1.03 mmol per liter). The patients were assigned to receive either 100 mg of anacetrapib once daily (15,225 patients) or matching placebo (15,224 patients). The primary outcome was the first major coronary event, a composite of coronary death, myocardial infarction, or coronary revascularization. RESULTS: During the median follow-up period of 4.1 years, the primary outcome occurred in significantly fewer patients in the anacetrapib group than in the placebo group (1640 of 15,225 patients [10.8%] vs. 1803 of 15,224 patients [11.8%]; rate ratio, 0.91; 95% confidence interval, 0.85 to 0.97; P=0.004). The relative difference in risk was similar across multiple prespecified subgroups. At the trial midpoint, the mean level of HDL cholesterol was higher by 43 mg per deciliter (1.12 mmol per liter) in the anacetrapib group than in the placebo group (a relative difference of 104%), and the mean level of non-HDL cholesterol was lower by 17 mg per deciliter (0.44 mmol per liter), a relative difference of -18%. There were no significant between-group differences in the risk of death, cancer, or other serious adverse events. CONCLUSIONS: Among patients with atherosclerotic vascular disease who were receiving intensive statin therapy, the use of anacetrapib resulted in a lower incidence of major coronary events than the use of placebo. (Funded by Merck and others; Current Controlled Trials number, ISRCTN48678192 ; ClinicalTrials.gov number, NCT01252953 ; and EudraCT number, 2010-023467-18 .)

RABBITS - I. The crucial role of nuclear star formation in driving the coalescence of supermassive black hole binaries

In this study of the 'Resolving supermAssive Black hole Binaries In galacTic hydrodynamical Simulations' (RABBITS) series, we focus on the hardening and coalescing process of supermassive black hole (SMBH) binaries in galaxy mergers. For simulations including different galaxy formation processes (i.e. gas cooling, star formation, SMBH accretion, stellar, and AGN feedback), we systematically control the effect of stochastic eccentricity by fixing it to similar values during the SMBH hardening phase. We find a strong correlation between the SMBH merger time-scales and the presence of nuclear star formation. Throughout the galaxy merging process, gas condenses at the centre due to cooling and tidal torques, leading to nuclear star formation. These recently formed stars, which inherit low angular momenta from the gas, contribute to the loss cone and assist in the SMBH hardening via three-body interactions. Compared to non-radiative hydrodynamical runs, the SMBH merger time-scales measured from the runs including cooling, stellar, and SMBH physical processes tend to be shortened by a factor of ∼1.7. After fixing the eccentricity to the range of e ∼ 0.6-0.8 during the hardening phase, the simulations with AGN feedback reveal merger time-scales of ∼100-500 Myr for disc mergers and ∼1-2 Gyr for elliptical mergers. With a semi-analytical approach, we find that the torque interaction between the binary and its circumbinary disc has minimal impact on the shrinking of the binary orbit in our retrograde galaxy merger. Our results are useful in improving the modelling of SMBH merger time-scales and gravitational-wave event rates.Peer reviewe

Land

Changing climate patterns, economic globalization, population growth, increasing use of natural resources and rapid urbanization are putting pressure on terrestrial ecosystems as never before, and virtually all of them are under stress. Biophysical limits on what is available for human use are real and there are strong signals that these limits are close to being reached or have already been exceeded (Rockström et al. 2009). Even so, the fact that some areas show recent gains in forested area or land reclamation (Lambin and Meyfroidt 2010; Nepstad et al. 2009; Bai et al. 2008) suggests that declines are not inevitable, and indeed that recovery may be possible – even though original ecosystem functions may be modified or pressure on ecosystems may shift elsewhere (Meyfroidt et al. 2010).Fil: Hunsberger, Carol. No especifíca;Fil: Evans, Tom P.. No especifíca;Fil: Aide, T. Mitchell. No especifíca;Fil: Albaladejo Montoro, Juan. No especifíca;Fil: Borras Jr., Saturnino M.. No especifíca;Fil: del Valle, Hector Francisco. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Nacional Patagónico; ArgentinaFil: Devisscher, Tahia. No especifíca;Fil: Jabbour, Jason. No especifíca;Fil: Kant, Shashi. No especifíca;Fil: López-Carr, David. No especifíca;Fil: Masundire, Hillary. No especifíca;Fil: Pricope, Narcisa G.. No especifíca;Fil: Sánchez-Rodriguez, Roberto. No especifíca;Fil: Abdelhamid, Magdi T.. No especifíca;Fil: Alfthan, Björn. No especifíca;Fil: Ayache, Fethi. No especifíca;Fil: Asefaw Berhe, Asmeret. No especifíca;Fil: Chinweze, Chizoba. No especifíca;Fil: Frélichová, Jana. No especifíca;Fil: Hislop, Lawrence.. No especifíca;Fil: Pan, William K.. No especifíca;Fil: Schulte-Herbrüggen, Björn. No especifíca;Fil: Smith, Jessica. No especifíca;Fil: Souza Jr., Carlos. No especifíca;Fil: Timmins, Tracy L.. No especifíca;Fil: Zulu, Leo C.. No especifíca