Probing the isovector transition strength of the low-lying nuclear excitations induced by inverse kinematics proton scattering

A compact approach based on the folding model is suggested for the determination of the isoscalar and isovector transition strengths of the low-lying ($\Delta S=\Delta T=0$) excitations induced by inelastic proton scattering measured with exotic beams. Our analysis of the recently measured inelastic $^{18,20}$O+p scattering data at $E_{\rm lab}=30$ and 43 MeV/nucleon has given for the first time an accurate estimate of the isoscalar $\beta_0$ and isovector $\beta_1$ deformation parameters (which cannot be determined from the (p,p') data alone by standard methods) for 2$^+_1$ and $3^-_1$ excited states in $^{18,20}$O. Quite strong isovector mixing was found in the 2$^+_1$ inelastic $^{20}$O+p scattering channel, where the strength of the isovector form factor $F_1$ (prototype of the Lane potential) corresponds to a $\beta_1$ value almost 3 times larger than $\beta_0$ and a ratio of nuclear transition matrix elements $M_n/M_p\simeq 4.2$.Comment: 5 pages, 3 figure

Waiting for coronary revascularization: A comparison between New York State, the Netherlands and Sweden

Objective: To compare waiting times for percutaneous transluminal coronary angioplasty (PTCA) and coronary artery bypass graft (CABG) surgery in New York State, the Netherlands and Sweden and to determine whether queuing adversely affects patients' health. Methods: We reviewed the medical records of 4487 chronic stable angina patients who underwent PTCA or CABG in one of 15 New York State hospitals (n = 1021) or were referred for PTCA or CABG to one of ten hospitals in the Netherlands (n = 1980) or to one of seven hospitals in Sweden (n = 1486). We measured the median waiting time between coronary angiography and PTCA or CABG. Results: The median waiting time for PTCA in New York was 13 days compared with 35 and 42 days, respectively, in the Netherlands and Sweden (P<0.001). For CABG, New York patients waited 17 days, while Dutch and Swedish patients waited 72 and 59 days, respectively (P< 0.001). The Swedish and Dutch waiting list mortality rate was 0.8% for CABG candidates and 0.15% for PTCA candidates. Conclusions: There were large variations in waiting time for coronary revascularization among these three sites. Patients waiting for CABG were at greatest risk of experiencing an adverse event. In both the Netherlands and Sweden, the capacity to perform coronary revascularization has been expanded since this study began. Further international cooperation may identify other areas where quality of care can be improved

Indications for coronary revascularisation: a Dutch perspective

OBJECTIVE: To assess the appropriateness of indications for coronary artery bypass graft (CABG) surgery and percutaneous transluminal coronary angioplasty (PTCA). METHODS: A modified Delphi group judgement process with input from a panel of six interventional cardiologists and six cardiopulmonary surgeons. There was one clinician from each of the 12 tertiary referral heart centres in The Netherlands. MAIN OUTCOME MEASURE: Ratings by panel members, on a 1 to 9 scale, of indications presented as a choice between two treatments (CABG v medical treatment, PTCA v medical treatment, and CABG v PTCA) for 1182 model cases. Each case represented a unique combination of clinical features in terms of symptoms, medical history, and results of tests. Ratings were analysed with respect to degree of agreement among panelists, degree of appropriateness of indications, and panel's preference for invasive or medical treatment. RESULTS: The panel agreed on 58.6% and disagreed on 3.2% of the indications. The panel opted for invasive treatment in 48.2% and medical treatment in 22.8%, and had no clear preference for either method in 29.0% of the cases. When compared with medical treatment, CABG was more often rated appropriate than PTCA: 35.4% v 21.6% (P < 0.001). Panel scores depended on severity of anatomical disease. For instance, for 51.5% of the model cases with one-vessel disease not including the proximal left anterior descending artery, the panel preferred medical treatment to invasive treatment, while the latter was preferred in 18% of the cases. In cases with type C lesions, the panel frequently rated PTCA as inappropriate. Panel scores were also affected by nonclinical factors. Cardiologists and surgeons rated the procedure of their own specialty higher than the alternative invasive intervention. CONCLUSIONS: The panel method yields logically consistent scores of the appropriateness of indications for carrying out medical procedures. It may be an aid in formulating clinical practice guidelines

Energy landscape of relaxed amorphous silicon

We analyze the structure of the energy landscape of a well-relaxed 1000-atom model of amorphous silicon using the activation-relaxation technique (ART nouveau). Generating more than 40,000 events starting from a single minimum, we find that activated mechanisms are local in nature, that they are distributed uniformly throughout the model and that the activation energy is limited by the cost of breaking one bond, independently of the complexity of the mechanism. The overall shape of the activation-energy-barrier distribution is also insensitive to the exact details of the configuration, indicating that well-relaxed configurations see essentially the same environment. These results underscore the localized nature of relaxation in this material.Comment: 8 pages, 12 figure

Financial diversification before modern portfolio theory: UK financial advice documents in the late nineteenth and the beginning of the twentieth century

The paper offers textual evidence from a series of financial advice documents in the late nineteenth century and the early twentieth century of how UK investors perceived of and managed risk. In the world’s largest financial centre of the time, UK investors were familiar with the concept of correlation and financial advisers’ suggestions were consistent with the recommendations of modern portfolio theory in relation to portfolio selection strategies. From the 1870s, there was an increased awareness of the benefits of financial diversification - primarily putting equal amounts into a number of different securities - with much of the emphasis being on geographical rather than sectoral diversification and some discussion of avoiding highly correlated investments. Investors in the past were not so naïve as mainstream financial discussions suggest today

Global profiling of the proteomic changes associated with the post-testicular maturation of mouse spermatozoa

Spermatozoa acquire fertilization potential during passage through a highly specialized region of the extratesticular ductal system known as the epididymis. In the absence of de novo gene transcription or protein translation, this functional transformation is extrinsically driven via the exchange of varied macromolecular cargo between spermatozoa and the surrounding luminal plasma. Key among these changes is a substantive remodeling of the sperm proteomic architecture, the scale of which has yet to be fully resolved. Here, we have exploited quantitative mass spectrometry-based proteomics to define the extent of changes associated with the maturation of mouse spermatozoa; reporting the identity of >6,000 proteins, encompassing the selective loss and gain of several hundred proteins. Further, we demonstrate epididymal-driven activation of RHOAmediated signaling pathways is an important component of sperm maturation. These data contribute molecular insights into the complexity of proteomic changes associated with epididymal sperm maturation.David A. Skerrett-Byrne, Amanda L. Anderson, Elizabeth G. Bromfield, Ilana R. Bernstein, Jess E. Mulhall, John E. Schjenken, Matthew D. Dun, Sean J. Humphrey, and Brett Nixo

Dimensionless cosmology

Although it is well known that any consideration of the variations of fundamental constants should be restricted to their dimensionless combinations, the literature on variations of the gravitational constant $G$ is entirely dimensionful. To illustrate applications of this to cosmology, we explicitly give a dimensionless version of the parameters of the standard cosmological model, and describe the physics of Big Bang Neucleosynthesis and recombination in a dimensionless manner. The issue that appears to have been missed in many studies is that in cosmology the strength of gravity is bound up in the cosmological equations, and the epoch at which we live is a crucial part of the model. We argue that it is useful to consider the hypothetical situation of communicating with another civilization (with entirely different units), comparing only dimensionless constants, in order to decide if we live in a Universe governed by precisely the same physical laws. In this thought experiment, we would also have to compare epochs, which can be defined by giving the value of any {\it one} of the evolving cosmological parameters. By setting things up carefully in this way one can avoid inconsistent results when considering variable constants, caused by effectively fixing more than one parameter today. We show examples of this effect by considering microwave background anisotropies, being careful to maintain dimensionlessness throughout. We present Fisher matrix calculations to estimate how well the fine structure constants for electromagnetism and gravity can be determined with future microwave background experiments. We highlight how one can be misled by simply adding $G$ to the usual cosmological parameter set

Determination of the Strange Quark Content of the Nucleon from a Next-to-Leading-Order QCD Analysis of Neutrino Charm Production

We present the first next-to-leading-order QCD analysis of neutrino charm production, using a sample of 6090 $\nu_\mu$- and $\bar\nu_\mu$-induced opposite-sign dimuon events observed in the CCFR detector at the Fermilab Tevatron. We find that the nucleon strange quark content is suppressed with respect to the non-strange sea quarks by a factor \kappa = 0.477 \: ^{+\:0.063}_{-\:0.053}, where the error includes statistical, systematic and QCD scale uncertainties. In contrast to previous leading order analyses, we find that the strange sea $x$-dependence is similar to that of the non-strange sea, and that the measured charm quark mass, $m_c = 1.70 \pm 0.19 \:{\rm GeV/c}^2$, is larger and consistent with that determined in other processes. Further analysis finds that the difference in $x$-distributions between $xs(x)$ and $x\bar s(x)$ is small. A measurement of the Cabibbo-Kobayashi-Maskawa matrix element $|V_{cd}|=0.232 ^{+\:0.018}_{-\:0.020}$ is also presented. uufile containing compressed postscript files of five Figures is appended at the end of the LaTeX source.Comment: Nevis R#150