1,137 research outputs found
Incorporating pathological gait into patient-specific finite element models of the haemophilic ankle
Haemarthrosis is an inherent clinical feature of haemophilia, a disease characterised by an absence or reduction in clotting proteins. Patients with severe haemophilia experience joint bleeding leading to blood-induced ankle arthropathy (haemarthropathy). Altered biomechanics of the ankle have been reported in people with haemophilia; however, the consequence of this on joint health is little understood. The aim of this study was to assess the changes in joint contact due to haemophilia disease-specific gait features using patient-specific modelling, to better understand the link between biomechanics and joint outcomes. Four, image-based, finite element models of haemophilic ankles were simulated through consecutive events in the stance phase of gait, using both patient-specific and healthy control group (n = 36) biomechanical inputs. One healthy control FE model was simulated through the healthy control stance phase of the gait cycle for a point of comparison. The method developed allowed cartilage contact mechanics to be assessed throughout the loading phase of the gait cycle. This showed areas of increased contact pressure in the medial and lateral regions of the talar dome, which may be linked to collapse in these regions. This method may allow the relationship between structure and function in the tibiotalar joint to be better understood
Non-resonant direct p- and d-wave neutron capture by 12C
Discrete gamma-rays from the neutron capture state of 13C to its low-lying
bound states have been measured using pulsed neutrons at En = 550 keV. The
partial capture cross sections have been determined to be 1.7+/-0.5,
24.2+/-1.0, 2.0+/-0.4 and 1.0+/-0.4 microb for the ground (1/2-), first (1/2+),
second (3/2-) and third (5/2+) excited states, respectively. From a comparison
with theoretical predictions based on the non-resonant direct radiative capture
mechanism, we could determine the spectroscopic factor for the 1/2+ state to be
0.80 +/- 0.04, free from neutron-nucleus interaction ambiguities in the
continuum. In addition we have detected the contribution of the non-resonant
d-wave capture component in the partial cross sections for transitions leading
to the 1/2- and 3/2- states. While the s-wave capture dominates at En < 100
keV, the d-wave component turns out to be very important at higher energies.
From the present investigation the 12C(n,gamma)13C reaction rate is obtained
for temperatures in the range 10E+7 - 10E+10 K.Comment: Accepted for publication in Phys. Rev. C. - 16 pages + 8 figure
Lifetime measurements in Co and Co
Lifetimes of the and states in Co and the
state in Co were measured using the recoil distance Doppler
shift and the differential decay curve methods. The nuclei were populated by
multi-nucleon transfer reactions in inverse kinematics. Gamma rays were
measured with the EXOGAM Ge array and the recoiling fragments were fully
identified using the large-acceptance VAMOS spectrometer. The E2 transition
probabilities from the and states to the ground
state could be extracted in Co as well as an upper limit for the
(E2) value in Co. The experimental
results were compared to large-scale shell-model calculations in the and
model spaces, allowing to draw conclusions on the single-particle
or collective nature of the various states.Comment: 8 pages, 8 figures, 1 table, accepted for publication in Physical
Review
Exploring the performance of the spectrometer prisma in heavy zirconium and xenon mass regions
We present results from two recent runs which illustrate the performance of the PRISMA spectrometer in the proximity of the upper limit of its operational interval, namely 96Zr + 124Sn at Elab = 500 MeV and 136Xe + 208Pb at Elab = 930 MeV. In the latter run, the γ array CLARA also allowed us to identify previously unknown γ transitions in the nuclides 136Cs and 134I
Genetic variability and population structuring in the European Lanner Falcon Falco biarmicus feldeggii
We analysed variation in 10 polymorphic microsatellites and a variable portion of control region of mtDNA in 24 specimens from 3 populations of European Lanner Falcon Falco biarmicus feldeggii living in Sicily, continental Italy and the Balkan area to assess species' genetic diversity and population structure in the poorly investigated range of this threatened subspecies. We considered also a dataset of previously published mtDNA sequences of the other Lanner Falcon subspecies and of Hierofalco subgenus members (F. cherrug, F. rusticolus and F. jugger) to outline the genetic variation in the region on a wide-ranging basis. Regard with mtDNA we identified 6 haplotypes from our 24 European Lanner Falcon specimens, 3 of which were new and unique (1 Sicilian, 2 Balkans) and the 3 others already known and shared with other Hierofalcons. The 62.5% of our sample, including 14 of Sicilians and one Apulia specimen, belonged to haplotype H_24 shared with F. c. cherrug, F. rusticolus and F. jugger. MtDNA analyses of European Lanner Falcons showed a dispersed pattern of our specimens inside the main Hierofalco clades and haplo-groups in a way congruent to what found in recent literature. These analyses confirmed that none of the Hierofalcons form a monophyletic group, nonetheless the Lanner Falcons can be subdivided in two major Palaearctic (F. b. feldeggii, F. b. erlangeri and F. b. tanypterus) and sub-Sahara African (F. b. biarmicus and F. b. abyssinicus) clades. Microsatellites analysis yielded a first outline of population genetic structure, with genetic identity between continental Italy and Sicily and a moderate degree of differentiation of the Balkan area with Sicily and continental Italy. The 3 populations did not show significant departure from Hardy-Weinberg equilibrium, with low values of the inbreeding coefficients and had allele richness and haplotype diversity consistent with literature. Microsatellites analysis (Nm, frequency of private alleles) suggests a gene flow among the three examined populations and the connection of Sicilian population to those of mainland
Pulse shape analysis of signals from BaF2 and CeF3 scintillators for neutron capture experiments
The scope of this work is to study the characteristics of BaF2 and CeF3 signals using fast digitizers, which allow the sampling of the signal at very high frequencies and the application of the fitting method for analysis of the recorded pulses. By this procedure particle identification and the reconstruction of pile-up events can be improved, while maintaining the energy and time-of-flight resolution as compared to traditional methods. The reliability of the technique and problems connected with data acquisition are discussed with respect to accurate measurements of neutron capture cross-sections
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