The Rarity of Star Formation in Brightest Cluster Galaxies as Measured by WISE

We present the mid-infrared (IR) star formation rates of 245 X-ray selected, nearby (z<0.1) brightest cluster galaxies (BCGs). A homogeneous and volume limited sample of BCGs was created by X-ray selecting clusters with L_x > 1x10^44 erg/s. The Wide-Field Infrared Survey Explorer (WISE) AllWISE Data Release provides the first measurement of the 12 micron star formation indicator for all BCGs in the nearby Universe. Perseus A and Cygnus A are the only galaxies in our sample to have star formation rates of > 40 M_sol/yr, indicating that these two galaxies are highly unusual at current times. Stellar populations of 99 +/- 0.6 % of local BCGs are (approximately) passively evolving, with star formation rates of <10 M_sol/yr. We find that in general, star formation produces only modest BCG growth at the current epoch.Comment: 5 pages, 3 figures, accepted for publication in MNRA

Regulation of cAMP responses by the G12/13 pathway converges on adenylyl cyclase VII

Regulation of intracellular cyclic adenosine 3’, 5’-monophosphate (cAMP) by multiple pathways enables differential function of this ubiquitous second messenger in a context dependent manner. Modulation of Gs-stimulated intracellular cAMP has long been known to be modulated by the Gi and Gq/Ca2+ pathways. Recently, the G13 pathway was also shown to facilitate cAMP responses in murine macrophage cells. We report here that this synergistic regulation of cAMP synthesis by the Gs and G13 pathways is mediated by a specific isoform of adenylyl cyclase, AC7. Furthermore, this signaling paradigm exists in several hematopoietic lineages and can be recapitulated by exogenous expression of AC7 in HEK 293 cells. Mechanistic characterization of this synergistic interaction indicates that it occurs downstream of receptor activation and it can be mediated by the alpha subunit of either G12 or G13. Our results demonstrate that AC7 is a specific downstream effector of the G12/13 pathway

Pectus updates and special considerations in Marfan syndrome.

Congenital chest wall or pectus deformities including pectus excavatum (funnel chest) and pectus carinatum (pigeon chest) affect a significant proportion of the general population and up to 70% of patients with Marfan syndrome. Patients often experience significant morbidity and psychological distress, which can worsen with age. Here we discuss new techniques for both operative and non-operative treatment of pectus deformity, the importance of a welltimed intervention and special considerations in patients with Marfan syndrome

An unusual case of pancreatic fistula.

We report an unusual case of a pancreatic fistula communicating with an appendicectomy wound. This occurred following an episode of acute haemorrhagic pancreatitis. The patient was initially admitted with signs and symptoms indicating appendicitis and went to theatre for an open appendicectomy. However, this did not resolve his symptoms and a laparotomy was performed the next day revealing haemorrhagic pancreatitis. He endured a stormy post-operative course, the cause of which was found to be an external pancreatic fistula with discharge of amylase-rich fluid from the Lanz incision. A trial of conservative management failed despite multiple percutaneous drainage procedures and treatment with broad-spectrum antibiotics. After a second opinion was sought, it was decided to fit a roux loop anastomosis between the head of the pancreas and the duodenum to divert the fistulous fluid. This procedure was a success and the patient remains well 2 years later

Consumption of salt rich products in the UK: impact of the reduced salt campaign

YesThis paper makes use of a leading UK supermarket’s loyalty card based data which records information on purchase decisions by consumers who shop at its stores in order to assess the effectiveness and impact of the UK reduced salt campaign. We present an empirical analysis of consumption data to assess the effectiveness of the UK Food Standard Agency’s (FSA) ‘reduced salt campaign’ on the basis of information on health related announcements undertaken by the FSA under its ‘low salt campaign’. We adopt a general approach to determining structural breaks in consumption data, including making use of minimum LM unit root tests whereby structural breaks are endogenously determined from the data. We find evidence supporting the effectiveness of the FSA’s reduced salt campaign

Acoustic oscillations in stars near the tip of the red giant branch

Small amplitude oscillations are observed in red giant branch (RGB) stars. Data on such oscillations are a source of information about the objects, notably about properties of convection in their envelopes and about the systems these objects inhabit. The OGLE-III catalog contains data for about 80 thousand small amplitude variable red giants (OSARGs) in the Large Magellanic Cloud. We want to explain variability in OSARGs as the solar-like oscillation and to associate the peaks in power spectra with frequencies of acoustic modes. We use data on reddening-free magnitudes of the objects and interpret them in terms of stellar physical parameters using tabulated isochrones calculated for ages and composition parameters corresponding to the upper RGB of the LMC. Massive data on the peak frequencies and amplitudes are compared with expectations for stochastically excited oscillations. The frequencies are also compared with those calculated for radial modes in envelope models with parameters taken from the isochrones. In stars close to the tip of the RGB, the peaks in power spectra are found in the 0.1-1.0 $\mu$Hz range, which is consistent with extrapolation of the frequency-luminosity relation for the solar-like oscillation. The dominant peaks occur close to the first two radial overtones. The increase in amplitude with luminosity is slower than linear. The exponent s=0.9 is similar to what is found from recent analysis of CoRoT data on less luminous red giants. Frequency separations between dominant peaks are found to be smaller by about 20% than calculated separations between these modes. After examining various possibilities, we left this discrepancy unexplained. The small amplitude variability of stars at the RGB tip is likely to be caused by a stochastic excitation of acoustic oscillations, but interpreting of individual peaks in power spectra presents a problem.Comment: Accepted for publication in Astronomy and Astrophysics, 6 pages, 6 figure

First-passage theory of exciton population loss in single-walled carbon nanotubes reveals micron-scale intrinsic diffusion lengths

One-dimensional crystals have long range translational invariance which manifests as long exciton diffusion lengths, but such intrinsic properties are often obscured by environmental perturbations. We use a first-passage approach to model single-walled carbon nanotube (SWCNT) exciton dynamics (including exciton-exciton annihilation and end effects) and compare it to results from both continuous-wave and multi-pulse ultrafast excitation experiments to extract intrinsic SWCNT properties. Excitons in suspended SWCNTs experience macroscopic diffusion lengths, on the order of the SWCNT length, (1.3-4.7 um) in sharp contrast to encapsulated samples. For these pristine samples, our model reveals intrinsic lifetimes (350-750 ps), diffusion constants (130-350 cm^2/s), and absorption cross-sections (2.1-3.6 X 10^-17 cm^2/atom) among the highest previously reported.and diffusion lengths for SWCNTs.Comment: 6 pages, 3 figure

Photodesorption of CO ice

At the high densities and low temperatures found in star forming regions, all molecules other than H2 should stick on dust grains on timescales shorter than the cloud lifetimes. Yet these clouds are detected in the millimeter lines of gaseous CO. At these temperatures, thermal desorption is negligible and hence a non-thermal desorption mechanism is necessary to maintain molecules in the gas phase. Here, the first laboratory study of the photodesorption of pure CO ice under ultra high vacuum is presented, which gives a desorption rate of 3E-3 CO molecules per UV (7-10.5 eV) photon at 15 K. This rate is factors of 1E2-1E5 larger than previously estimated and is comparable to estimates of other non-thermal desorption rates. The experiments constrains the mechanism to a single photon desorption process of ice surface molecules. The measured efficiency of this process shows that the role of CO photodesorption in preventing total removal of molecules in the gas has been underestimated.Comment: 5 pages, 4 figures, accepted by ApJ

Nuclear expression of Lyn, a Src family kinase member, is associated with poor prognosis in renal cancer patients

Background: 8000 cases of renal cancer are diagnosed each year in the UK, with a five-year survival rate of 50 %. Treatment options are limited; a potential therapeutic target is the Src family kinases (SFKs). SFKs have roles in multiple oncogenic processes and promote metastases in solid tumours. The aim of this study was to investigate SFKs as potential therapeutic targets for clear cell renal cell carcinoma (ccRCC). Methods: SFKs expression was assessed in a tissue microarray consisting of 192 ccRCC patients with full clinical follow-up. SFK inhibitors, dasatinib and saracatinib, were assessed in early ccRCC cell lines, 786-O and 769-P and a metastatic ccRCC cell line, ACHN (± Src) for effects on protein expression, apoptosis, proliferation and wound healing. Results: High nuclear expression of Lyn and the downstream marker of activation, paxillin, were associated with decreased patient survival. Conversely, high cytoplasmic expression of other SFK members and downstream marker of activation, focal adhesion kinase (FAK) were associated with increased patient survival. Treatment of non-metastatic 786-O and 769-P cells with dasatinib, dose dependently reduced SFK activation, shown via SFK (Y419) and FAK (Y861) phosphorylation, with no effect in metastatic ACHN cells. Dasatinib also increased apoptosis, while decreasing proliferation and migration in 786-O and 769-P cell lines, both in the presence and absence of Src protein. Conclusions: Our data suggests that nuclear Lyn is a potential therapeutic target for ccRCC and dasatinib affects cellular functions associated with cancer progression via a Src kinase independent mechanism