Perturbative expansions from Monte Carlo simulations at weak coupling: Wilson loops and the static-quark self-energy

Perturbative coefficients for Wilson loops and the static-quark self-energy are extracted from Monte Carlo simulations at weak coupling. The lattice volumes and couplings are chosen to ensure that the lattice momenta are all perturbative. Twisted boundary conditions are used to eliminate the effects of lattice zero modes and to suppress nonperturbative finite-volume effects due to Z(3) phases. Simulations of the Wilson gluon action are done with both periodic and twisted boundary conditions, and over a wide range of lattice volumes (from $3^4$ to $16^4$) and couplings (from $\beta \approx 9$ to $\beta \approx 60$). A high precision comparison is made between the simulation data and results from finite-volume lattice perturbation theory. The Monte Carlo results are shown to be in excellent agreement with perturbation theory through second order. New results for third-order coefficients for a number of Wilson loops and the static-quark self-energy are reported.Comment: 36 pages, 15 figures, REVTEX documen

Surveillance for pancreatic cancer in high-risk individuals

Background Surveillance of individuals at high risk of pancreatic ductal adenocarcinoma (PDAC) and its precursors might lead to better outcomes. The aim of this study was to determine the prevalence and outcomes of PDAC and high-risk neoplastic precursor lesions among such patients participating in surveillance programmes. Methods A multicentre study was conducted through the International CAncer of the Pancreas Screening (CAPS) Consortium Registry to identify high-risk individuals who had undergone pancreatic resection or progressed to advanced PDAC while under surveillance. High-risk neoplastic precursor lesions were defined as: pancreatic intraepithelial neoplasia (PanIN) 3, intraductal papillary mucinous neoplasia (IPMN) with high-grade dysplasia, and pancreatic neuroendocrine tumours at least 2 cm in diameter. Results Of 76 high-risk individuals identified in 11 surveillance programmes, 71 had undergone surgery and five had been diagnosed with inoperable PDAC. Of the 71 patients who underwent resection, 32 (45 per cent) had PDAC or a high-risk precursor (19 PDAC, 4 main-duct IPMN, 4 branch-duct IPMN, 5 PanIN-3); the other 39 patients had lesions thought to be associated with a lower risk of neoplastic progression. Age at least 65 years, female sex, carriage of a gene mutation and location of a lesion in the head/uncinate region were associated with high-risk precursor lesions or PDAC. The survival of high-risk individuals with low-risk neoplastic lesions did not differ from that in those with high-risk precursor lesions. Survival was worse among patients with PDAC. There was no surgery-related mortality. Conclusion A high proportion of high-risk individuals who had surgical resection for screening- or surveillance-detected pancreatic lesions had a high-risk neoplastic precursor lesion or PDAC at the time of surgery. Survival was better in high-risk individuals who had either low- or high-risk neoplastic precursor lesions compared with that in patients who developed PDAC

Extreme multi-valence states in mixed actinide oxides

To assure the safety of oxide-fuel based nuclear reactors, the knowledge of the atomic-scale properties of U1−yMyO2±x materials is essential. These compounds show complex chemical properties, originating from the fact that actinides and rare earths may occur with different oxidation states. In these mostly ionic materials, aliovalent cationic configurations can induce changes in the oxygen stoichiometry, with dramatic effects on the properties of the fuel. First studies on U1−yAmyO2±x indicated that these materials exhibit particularly complex electronic and local-structure configurations. Here we present an in-depth study of these compounds, over a wide compositional domain, by combining XRD, XAS and Raman spectroscopy. We provide evidences of the co-existence of four different cations (U4+, U5+, Am3+, Am4+) in U1−yMyO2±x compounds, which nevertheless maintain the fluorite structure. Indeed, we show that the cationic sublattice is basically unaffected by the extreme multi-valence states, whereas complex defects are present in the oxygen sublattice

Pathogens that cause acute febrile illness among children and adolescents in Burkina Faso, Madagascar and Sudan

BACKGROUND: The etiology and optimal clinical management of acute febrile illness (AFI) is poorly understood. METHODS: Blood samples taken from study participants with acute fever (>/=37.5 degrees C) or a history of fever and recruited into the previous Typhoid-Fever-Surveillance-in-Africa (TSAP) study were evaluated using a polymerase chain reaction (PCR)-based TaqMan-Array Card designed to detect a panel of bacterial, viral and parasitic pathogens. Clinical metadata were also assessed. RESULTS: A total of 615 blood samples available for analysis originated from Burkina Faso (n=53), Madagascar (n=364) and Sudan (n=198) and were taken from participants ranging from 0-19 years of age. Most individuals [86.4% (531/615)] presenting at healthcare facilities were outpatient adolescents (11-19 years-old). Leading clinical diagnoses were respiratory tract infections [45.9% (282/615)], malaria [27.3% (168/615)], and gastrointestinal tract infections [10.7% (66/615)]. Through the TaqMan-Array Card, at least one pathogen was detected in 62% (33/53), 24% (86/364), and 60% (118/198) of specimens, from Burkina Faso, Madagascar and Sudan, respectively. The leading identified pathogen overall was Plasmodium spp., accounting for 47% (25/53), 2.2% (8/364) and 45% (90/198) of AFI at respective sites. In Madagascar, dengue virus was the most prevalent pathogen (10.2%). Overall, 69% (357/516) of patients with clinical diagnoses of malaria, respiratory, or gastrointestinal infections were prescribed a WHO-guideline-recommended empiric antibiotic,whereas only 45% (106/237) of patients with pathogens detected were treated with an antibiotic exerting likely activity. CONCLUSIONS: A PCR-approach for identifying multiple bacterial, viral and parasitic pathogens in whole blood unveiled a diversity of previously undetected pathogens in AFI cases and carries implications for the appropriate management of this common syndrome

Trade openness, real exchange rates and job reallocation

This paper investigates the impact of real exchange rate movements on job reallocation at the industry level. The analysis focuses on the manufacturing sector of Belgium, using data for 82 NACE 3-digit industries, over the time span 1996-2002. I find that real exchange rate changes do have a significant impact on job flows, and that this impact is magnified by increasing levels of trade exposure. In particular, a real appreciation is found to lower net employment growth through higher job destruction, while job creation is not significantly affected. These results are in line with previous empirical evidence on the United States, and differ from earlier findings for France and Germany, where the adjustment to real exchange rate shocks has been found to occur mainly through the job creation margin. I suggest that these differences may be explained by the fact that Belgium is a small open economy

Exponential distribution of long heart beat intervals during atrial fibrillation and their relevance for white noise behaviour in power spectrum

The statistical properties of heart beat intervals of 130 long-term surface electrocardiogram recordings during atrial fibrillation (AF) are investigated. We find that the distribution of interbeat intervals exhibits a characteristic exponential tail, which is absent during sinus rhythm, as tested in a corresponding control study with 72 healthy persons. The rate of the exponential decay lies in the range 3-12 Hz and shows diurnal variations. It equals, up to statistical uncertainties, the level of the previously uncovered white noise part in the power spectrum, which is also characteristic for AF. The overall statistical features can be described by decomposing the intervals into two statistically independent times, where the first one is associated with a correlated process with 1/f noise characteristics, while the second one belongs to an uncorrelated process and is responsible for the exponential tail. It is suggested to use the rate of the exponential decay as a further parameter for a better classification of AF and for the medical diagnosis. The relevance of the findings with respect to a general understanding of AF is pointed out