Mass limits for the progenitor star of supernova 2001du and other Type II-P supernovae

The supernova SN 2001du was discovered in the galaxy NGC 1365 at a distance of 19 +/- 2 Mpc, and is a core-collapse event of Type II-P. Images of this galaxy, of moderate depth, have been taken with the Hubble Space Telescope approximately 6.6 yr before discovery and include the supernova position on the WFPC2 field of view. We have observed the supernova with the WFPC2 to allow accurate differential astrometry of SN 2001du on the pre-explosion frames. As a core-collapse event it is expected that the progenitor was a massive, luminous star. There is a marginal detection (3sigma) of a source close to the supernova position on the pre-discovery V -band frame, but it is not precisely coincident and we do not believe it to be a robust detection of a point source. We conclude that there is no stellar progenitor at the supernova position and derive sensitivity limits of the pre-discovery images that provide an upper mass limit for the progenitor star. We estimate that the progenitor had a mass of less than 15 M-circle dot . We revisit two other nearby Type II-P supernovae that have high-quality pre-explosion images, and refine the upper mass limits for the progenitor stars. Using a new distance determination for SN 1999gi from the expanding photosphere method, we revise the upper mass limit to 12 M-circle dot . We present new HST images of the site of SN 1999em, which validate the use of lower spatial resolution ground-based images in the progenitor studies and use a new Cepheid distance to the galaxy to measure an upper mass limit of 15 M-circle dot for that progenitor. Finally we compile all the direct information available for the progenitors of eight nearby core-collapse supernovae and compare their mass estimates. These are compared with the latest stellar evolutionary models of pre-supernova evolution which have attempted to relate metallicity and mass to the supernovae type. Although this is statistically limited at present, reasonable agreement is already found for the lower-mass events (generally the II-P), but some discrepancies appear at higher masses.

INCIDENCE AND CLINICAL IMPORTANCE OF PERIOPERATIVE HISTAMINE-RELEASE - RANDOMIZED STUDY OF VOLUME LOADING AND ANTIHISTAMINES AFTER INDUCTION OF ANESTHESIA

Although histamine release is recognised as a common event during anaesthesia and surgery, few clinicians judge the resultant cardiorespiratory disturbances serious enough to warrant prophylaxis with antihistamines. We have assessed the incidence and importance of histamine release in a randomised 2 x 2 factorial study.

Chemical and mechanical stability of sodium sulfate activated slag after exposure to elevated temperature

The chemical and mechanical stability of slag activated with two different concentrations of sodium sulfate (Na₂SO₄) after exposure to elevated temperatures ranging from 200 to 800 °C with an increment of 200 °C has been examined. Compressive strengths and pH of the hardened pastes before and after the exposure were determined. The various decomposition phases formed were identified using X-ray diffraction, thermogravimetric analysis and scanning electron microscopy. The results indicated that Na₂SO₄ activated slag has a better resistance to the degradation caused by exposure to elevated temperature up to 600 °C than Portland cement system as its relative strengths are superior. The finer slag and higher Na₂SO₄ concentration gave better temperature resistance. Whilst the pH of the hardened pastes decreased with an increase in temperature, it still maintained a sufficiently high pH for the protection of reinforcing bar against corrosion.

Pharmacy Students’ Views of Faculty Feedback on Academic Performance

Objective: To investigate students' views on and satisfaction with faculty feedback on their academic performance.

Methods: A 41-item survey instrument was developed based on a literature review relating to effective feedback. All pharmacy undergraduate students were invited via e-mail to complete the self-administered electronic questionnaire relating to their views on feedback, including faculty feedback received to date regarding their academic performance.

Results: A response rate of 61% (343/561) was obtained. Only 32.3% of students (107/331) agreed that they were satisfied with the feedback they received; dissatisfaction with examination feedback was particularly high. The provision of faculty feedback was perceived to be variable in terms of quality and quantity.

Conclusions: There are some inconsistencies relating to provision of feedback within the MPharm degree program at Queen's University Belfast. Further work is needed to close the gap between student expectations and the faculty's delivery of feedback on academic performance.

Low-pressure solubilities and thermodynamics of solvation of eight gases in 1-butyl-3-methylimidazolium hexafluorophosphate

Experimental values for the solubility of carbon dioxide, ethane, methane, oxygen, nitrogen, hydrogen, argon and carbon monoxide in 1-butyl-3-methylimidazolium hexafluorophosphate, [bmim][PF6] - a room temperature ionic liquid - are reported as a function of temperature between 283 and 343 K and at pressures close to atmospheric. Carbon dioxide is the most soluble and hydrogen is the least soluble of the gases studied with mole fraction solubilities of the order of 10-2 and 10-4, respectively. All the mole fraction solubilities decrease with temperature except for hydrogen for which a maximum is observed at temperatures close to 310 K. From the variation of solubility, expressed as Henry's law constants, with temperature, the partial molar thermodynamic functions of solvation such as the standard Gibbs energy, the enthalpy, and the entropy are calculated. The precision of the experimental data, considered as the average absolute deviation of the Henry's law constants from appropriate smoothing equations, is better than ±1%. © 2005 Elsevier B.V. All rights reserved.

Influence of the cation on the solubility of CO2 and H 2 in ionic liquids based on the bis(trifluoromethylsulfonyl)imide anion

Experimental values for the solubility of carbon dioxide and hydrogen in three room temperature ionic liquids based on the same anion- (bistrifluoromethylsulfonyl)imide [Ntf2]-and three different cations-1-butyl-3-methylimidazolium, [C4mim], 1-ethyl-3- methylimidazolium, [C2mim] and trimethyl-butylammonium, [N 4111]-are reported between 283 and 343 K and close to atmospheric pressure. Carbon dioxide, with a mole-fraction solubility of the order of 10-2, is two orders of magnitude more soluble than hydrogen. The solubility of CO2 is very similar in the three ionic liquids although slightly lower in the presence of the [C2mim] cation. In the case of H2, noticeable differences were observed with larger mole fraction solubilities in the presence of [N4111] followed by [C 4mim]. All of the mole-fraction solubilities decrease with increasing temperature. From the variation of Henry's law constants with temperature, the thermodynamic functions of solvation were calculated. The precision of the experimental data, considered as the average absolute deviation of the Henry's law constants from appropriate smoothing equations, is always better than ±1%. © Springer Science+Business Media, LLC 2007.

Thermophysical properties, low pressure solubilities and thermodynamics of solvation of carbon dioxide and hydrogen in two ionic liquids based on the alkylsulfate anion

Densities and viscosities of the ionic liquid 1-butyl-3-methylimidazolium octylsulfate, [C4C1Im][C8SO4] were measured as a function of temperature between 313 K and 395 K. Solubilities of hydrogen and carbon dioxide were determined, between 283 K and 343 K, and at pressures close to atmospheric in [C4C1Im][C 8SO4] and in another ionic liquid based on the alkylsulfate anion-1-ethyl-3-methylimidazolium ethylsulfate, [C 2C1Im][C2SO4]. Density and viscosity were measured using a vibrating tube densimeter from Anton Paar and a rheometer from Rheometrics Scientific with accuracies of 10-3 g cm -3 and 1%, respectively. Solubilities were obtained using an isochoric saturation technique and, from the variation of solubility with temperature, the partial molar thermodynamic functions of solvation, such as the standard Gibbs energy, the enthalpy, and the entropy, are calculated. The precision of the experimental data, considered as the average absolute deviation of the Henry's law constants from appropriate smoothing equations, is better than ±1%. © The Royal Society of Chemistry.

Assessing the extent to which temporal changes in waterbird community composition are driven by either local, regional or global factors.

1. Lough Neagh and Lough Beg Special Protection Area (SPA, hereafter Lough Neagh) is an important non-estuarine site in Britain and Ireland for overwintering wildfowl. Multivariate analysis of the winter counts showed a state-shift in the waterbird community following winter 2000/2001, mostly due to rapid declines in abundance (46–57% declines in the mean mid-winter January counts between 1993–2000 and 2002–2009) of members of the diving duck guild (pochard Aythya ferina, tufted duck Aythya fuligula and goldeneye Bucephala clangula) and coot (Fulica atra), a submerged macrophyte feeder.
2. Only pochard showed correlations between declines at Lough Neagh and those of overall species flyway population indices to suggest that global changes could contribute to declines at the site. However, indices from the Republic of Ireland showed no overall decline in the rest of Ireland. Tufted duck indices at the site were inversely related to indices in Great Britain. Lough Neagh goldeneye indices were positively correlated with indices in the Republic of Ireland and Great Britain, suggesting that short-stopping could contribute to declines at the site. Coot declines at Lough Neagh did not correlate with trends elsewhere, suggesting local factors involved in the decline.
3. These analyses indicate that although there are potentially different explanations for the dramatic declines in these four waterbird species at this site, the simultaneous nature of the declines across two feeding guilds strongly
suggest that local factors (such as loss of submerged macrophytes and benthic invertebrates) were involved. An assessment of the food supply, local disturbance and other factors at Lough Neagh is required to find an explanation for the observed adverse trends in wintering numbers of the affected species.
4. This study highlights the potential of waterbird community structure to reflect the status of aquatic systems, but confirms the need to establish site-specific factors responsible for the observed changes in abundance of key waterbird species at a site.

China’s National Security Review: a tit-for-tat response?

China is gradually taking its place as a major regulator, exercising concurrent jurisdiction of the national security review along with the US and EU over high-profile cross-border mergers and acquisitions. The National Security Review (NSR) regulatory regime of foreign acquisitions has attracted significant attention recently with the establishment of China's counterpart to the Committee on Foreign Investment in the United States (CFIUS). Due to the intensified activities of sovereign wealth funds (SWFs) that are closely linked with states, CFIUS's broad discretion to deal with China's SWF-based investment may have a far-reaching impact on China's implementation of the newly enacted NSR regime. It is essential to design a mechanism that allows SWFs to maximise their positive attributes while safeguarding the apolitical integrity of the marketplace. Any disproportionate use of the NSR regime would inevitably bring about more unintended consequences, such as tit-for-tat protectionism. This represents an imminent threat to the tenuous recovery from the recent economic crisis, largely because of the increasingly intertwined and interdependent nature of the global financial markets. It is of utmost significance to evaluate the extent to which the updated legislation strikes a reasonable balance between preserving genuine national security interests and maintaining an open environment for investment.

Genetic renal abnormalities

Inherited disorders of renal structure and function are relatively common causes of end-stage renal disease requiring renal replacement therapy. A family history of haematuria, urinary tract infection or renal failure can alert the clinician to the possible diagnosis of underlying renal genetic abnormalities. In practice, the commonest inherited renal disorder is autosomal dominant polycystic kidney disease (ADPKD), characterized by multiple kidney cysts associated with hypertension and renal failure. Insights into the cell biology of ADPKD are informing new therapeutic approaches to limit cyst growth and prevent progressive renal failure. Non-visible haematuria is a clinical finding that presents a diagnostic challenge because it has so many possible causes. Mutations in the genes encoding collagen proteins within the glomerular basement membrane (GBM) can disrupt its normal barrier function. Thin basement membrane nephropathy, caused by GBM collagen gene mutations, is a relatively common cause of familial haematuria that normally has a good long-term prognosis. Alport syndrome is a rare and genetically heterogeneous condition leading to renal failure in men inheriting the X-linked gene defect. Single-gene defects may cause diverse renal tubular disorders, such as predisposition to renal calculi, diabetes insipidus, renal tubular acidosis or hypertension with associated electrolyte imbalance. Gene mutations responsible for familial renal cancer syndromes, such as tuberous sclerosis complex and von Hippel–Lindau disease, have also been identified

Measuring party organization: The vertical dimension of the multilevel organization of statewide parties in Spain and the UK

Over the past few years, attention to the role of state-wide political parties in multi-level polities has increased in recognition of their linkage function between levels of government, as these parties compete in both state-wide and regional elections across their countries. This article presents a coding scheme designed to describe the relationship between central and regional levels of state-wide parties. It evaluates the involvement of the regional branches in central decision-making and their degree of autonomy in the management of regional party affairs. This coding scheme is applied to state-wide parties in Spain (the socialist PSOE and the conservative Partido Popular) and in the UK (Labour, the Conservatives and the Liberal Democrats). It is an additional tool with which to analyse party organization and it facilitates the comparison of parties across regions and in different countries.