We present a measurement of the top quark pair production cross section in p (p) over bar collisions at root s = 1.96 TeV using approximately 1 fb(-1) collected with the DO detector. We consider ...decay channels containing two high p(T) charged leptons where one lepton is identified as an electron or a muon while the other lepton can be an electron, a muon or a hadronically decaying tau lepton. For a mass of the top quark of 170 GeV, the measured cross section is 7.5(-1.0)(+1.0)(stat)(-0.6)(+0.7)(syst)(-0.5)(+0.6)(lumi) pb. Using l tau events only, we measure: sigma(t (t) over bar) x B(t (t) over bar -> l tau b (b) over bar) = 0.13(-0.08)(+0.09)(stat)(-0.06)(+0.06)(syst)(-0.02)(+0.02)(lumi) pb. Comparing the measured cross section as a function of the mass of the top quark with a partial next-to-next-to leading order Quantum Chroniodynamics theoretical prediction, we extract a mass of the top quark of 171.5(-8.8)(+9-9) GeV, in agreement with direct measurements.
A 20-m sediment core from Rano Kau, Easter Island provides plant microfossil, arthropod fossil and high-resolution super(14)C sampling evidence for late Quaternary environments, ant (Formicidae) ...distributions and human activity. The record commences prior to or during the LGM, providing the two oldest dates for Rano Kau thus far, 20,340 plus or minus 160 and 34,260 plus or minus 440 BP. The vegetation at the time was mostly Arecaceae (palm)-dominated grassland-woodland, suggesting cooler/drier conditions than present. Near the start of the Holocene c. 12,500 cal BP, climate alleviation is indicated by Asteraceae shrubland increasing at the expense of grassland. There is an early to mid-Holocene sediment hiatus. The record recommences c. 3,500 cal BP, with in-washed clayey soils bearing charcoal and phytoliths of Polynesian-introduced Musa (banana) and mixed with wetland detritus, reflecting slumping as a result of forest clearance and gardening. Dates of material of other plants from the clay/detritus layers containing the Musa phytoliths are older than expected, within the range 3,680-2,750 cal BP, well before settlement of Eastern Polynesia. This could reflect horticultural material settling in an older part of the sediment column or age increase by reservoir effects. A long section of overlying unconsolidated detritus provides a progressively younger upward sequence from 2,840-2,870 to 930-810 cal BP, but dates are variable after 1,290-1,180 cal BP, where charcoal, disturbance-related pollen and older than expected ant exoskeletons demonstrate the inclusion of pre-aged material from the floating vegetation mat or upslope erosion in the sediment column. Arecaceae pollen declines sharply after 930-810 cal BP. Arthropod analysis reveals two new weevil species for Easter Island, and two ant taxa, Tetramorium bicarinatum and Pheidole sp., the latter of which is also new for the island. Three of the four age determinations on ant remains suggest that ants were present prior to c. 2,500 cal BP, and probably associated with the period following the resumption of sediment accumulation c. 3,500 cal BP. Unless the apparent ant super(14)C ages have been increased by reservoir effects, these results question the long-accepted assumption that all Eastern Polynesia's ant species have been introduced.
A 20-m sediment core from Rano Kau, Easter Island provides plant microfossil, arthropod fossil and high-resolution ^sup 14^C sampling evidence for late Quaternary environments, ant (Formicidae) ...distributions and human activity. The record commences prior to or during the LGM, providing the two oldest dates for Rano Kau thus far, 20,340 ± 160 and 34,260 ± 440 BP. The vegetation at the time was mostly Arecaceae (palm)-dominated grassland-woodland, suggesting cooler/drier conditions than present. Near the start of the Holocene c. 12,500 cal BP, climate alleviation is indicated by Asteraceae shrubland increasing at the expense of grassland. There is an early to mid-Holocene sediment hiatus. The record recommences c. 3,500 cal BP, with in-washed clayey soils bearing charcoal and phytoliths of Polynesian-introduced Musa (banana) and mixed with wetland detritus, reflecting slumping as a result of forest clearance and gardening. Dates of material of other plants from the clay/detritus layers containing the Musa phytoliths are older than expected, within the range 3,680-2,750 cal BP, well before settlement of Eastern Polynesia. This could reflect horticultural material settling in an older part of the sediment column or age increase by reservoir effects. A long section of overlying unconsolidated detritus provides a progressively younger upward sequence from 2,840-2,870 to 930-810 cal BP, but dates are variable after 1,290-1,180 cal BP, where charcoal, disturbance-related pollen and older than expected ant exoskeletons demonstrate the inclusion of pre-aged material from the floating vegetation mat or upslope erosion in the sediment column. Arecaceae pollen declines sharply after 930-810 cal BP. Arthropod analysis reveals two new weevil species for Easter Island, and two ant taxa, Tetramorium bicarinatum and Pheidole sp., the latter of which is also new for the island. Three of the four age determinations on ant remains suggest that ants were present prior to c. 2,500 cal BP, and probably associated with the period following the resumption of sediment accumulation c. 3,500 cal BP. Unless the apparent ant ^sup 14^C ages have been increased by reservoir effects, these results question the long-accepted assumption that all Eastern Polynesia's ant species have been introduced.PUBLICATION ABSTRACT
Let X and Y be reflexive Banach spaces with strictly convex duals, and let T be a compact linear map from X to Y. It is shown that a certain nonlinear equation, involving T and its adjoint, has a ...normalised solution (an ‘eigenvector’) corresponding to an ‘eigenvalue’, and that the same is true for each member of a countable family of similar equations involving the restrictions of T to certain subspaces of X. The action of T can be described in terms of these ‘eigenvectors’. There are applications to the p-Laplacian, the p-biharmonic operator and integral operators of Hardy type.
We present a search for associated production of Higgs and W bosons in inline image collisions at a center of mass energy of inline image in 5.3 fbsuper-1 of integrated luminosity recorded by the D0 ...experiment. Multivariate analysis techniques are applied to events containing one lepton, an imbalance in transverse energy, and one or two b-tagged jets to discriminate a potential WH signal from Standard Model backgrounds. We observe good agreement between data and expected backgrounds, and set an upper limit of 4.5 (at 95% confidence level and for m sub(H=115 GeV) on the ratio of the WH cross section multiplied by the branching fraction of inline image to its Standard Model prediction, which is consistent with an expected limit of 4.8.)
Background: With the decrease in junior doctor hours, the advent of specialist registrars, and the availability of highly trained and experienced nursing personnel, the service needs of patients with ...chronic respiratory diseases attending routine outpatient clinics may be better provided by appropriately trained nurse practitioners. Methods: A randomised controlled crossover trial was used to compare nurse practitioner led care with doctor led care in a bronchiectasis outpatient clinic. Eighty patients were recruited and randomised to receive 1 year of nurse led care and 1 year of doctor led care in random order. Patients were followed up for 2 years to ensure patient safety and acceptability and to assess differences in lung function. Outcome measures were forced expiratory volume in 1 second (FEV1), 12 minute walk test, health related quality of life, and resource use. Results: The mean difference in FEV1 was 0.2% predicted (95% confidence interval –1.6 to 2.0%, p=0.83). There were no significant differences in the other clinical or health related quality of life measures. Nurse led care resulted in significantly increased resource use compared with doctor led care (mean difference £1497, 95% confidence interval £688 to £2674, p<0.001), a large part of which resulted from the number and duration of hospital admissions. The mean difference in resource use was greater in the first year (£2625) than in the second year (£411). Conclusions: Nurse practitioner led care for stable patients within a chronic chest clinic is safe and is as effective as doctor led care, but may use more resources.
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