8,233 research outputs found
Quantifying whether different demographic models produce incongruent results on population dynamics of two long-term studied rodent species
1. Population density (ind/ha) of long-term (>15 years) series of CMR populations, using distinct demographic models designed for both open and closed populations, were analysed for two sympatric species of rodents (Myodes glareolus and Apodemus flavicollis) from a mountain area in central Italy, in order to test the relative performance of various employed demographic models. In particular, the hypothesis that enumeration models systematically underestimate the population size of a given population was tested.2. Overall, we compared the performance of 7 distinct demographic models, including both closed and open models, for each study species. Although the two species revealed remarkable intrinsic differences in demography traits (for instance, a lower propensity for being recaptured in Apodemus flavicollis), the Robust Design appeared to be the best fitting model, showing that it is the most suitable model for long-term studies.3. Among the various analysed demographic models, Jolly-Seber returned the lower estimates of population density for both species. Thus, this demographic model could not be suggested for being applied for long-term studies of small mammal populations because it tends to remarkably underestimate the effective population size. Nonetheless, yearly estimates of population density by Jolly-Seber correlated positively with yearly estimates of population density by closed population models, thus showing that interannual trends in population dynamics were uncovered by both types of demographic models, although with different values in terms of true population size
A Sound and Complete Axiomatization of Majority-n Logic
Manipulating logic functions via majority operators recently drew the
attention of researchers in computer science. For example, circuit optimization
based on majority operators enables superior results as compared to traditional
logic systems. Also, the Boolean satisfiability problem finds new solving
approaches when described in terms of majority decisions. To support computer
logic applications based on majority a sound and complete set of axioms is
required. Most of the recent advances in majority logic deal only with ternary
majority (MAJ- 3) operators because the axiomatization with solely MAJ-3 and
complementation operators is well understood. However, it is of interest
extending such axiomatization to n-ary majority operators (MAJ-n) from both the
theoretical and practical perspective. In this work, we address this issue by
introducing a sound and complete axiomatization of MAJ-n logic. Our
axiomatization naturally includes existing majority logic systems. Based on
this general set of axioms, computer applications can now fully exploit the
expressive power of majority logic.Comment: Accepted by the IEEE Transactions on Computer
Chirped seeded free-electron lasers: self-standing light sources for two-colour pump-probe experiments
We demonstrate the possibility to run a single-pass free-electron laser in a
new dynamical regime, which can be exploited to perform two-colour pump-probe
experiments in the VUV/X-ray domain, using the free-electron laser emission
both as a pump and as a probe. The studied regime is induced by triggering the
free-electron laser process with a powerful laser pulse, carrying a significant
and adjustable frequency chirp. As a result, the emitted light is eventually
split in two sub-pulses, whose spectral and temporal separations can be
independently controlled. We provide a theoretical description of this
phenomenon, which is found in good agreement with experiments performed on the
FERMI@Elettra free-electron laser
Gravitational-wave extraction from neutron-star oscillations
We compare different gravitational-wave extraction methods used in
three-dimensional nonlinear simulations against linear simulations of
perturbations of spherical spacetimes with matter. We present results from
fully general-relativistic simulations of a system composed by an oscillating
and non-rotating star emitting gravitational radiation. Results about the onset
of non-linear effects are also shown
PARX model for football matches predictions
We propose an innovative approach to model and predict the outcome of football matches based on the Poisson Autoregression with eXogenous covariates (PARX) model recently proposed by Agosto, Cavaliere, Kristensen and Rahbek (2016). We show that this methodology is particularly suited to model the goals distribution of a football team and provides a good forecast performance that can be exploited to develop a profitable betting strategy. The betting strategy is based on the idea that the odds proposed by the market do not reflect the true probability of the match because they may incorporate also the betting volumes or strategic price settings in order to exploit bettors’ biases. The out-of-sample performance of the PARX model is better than the reference approach by Dixon and Coles (1997). We also evaluate our approach in a simple betting strategy which is applied to the English football Premier League data for the 2013/2014 and 2014/2015 seasons. The results show that the return from the betting strategy is larger than 35% in all the cases considered and may even exceed 100% if we consider an alternative strategy based on a predetermined threshold which allows to exploit the inefficiency of the betting market
Adjuvant radiation therapy in stage I seminoma: 20 years of oncologic results
Aim: To report long term oncologic outcomes after adjuvant radiotherapy (RT) for stage I seminoma.
Method: We reviewed the complete data set for all patients treated at our institute between 1988 and 2005 for stage I seminoma with adjuvant RT after radical orchiectomy.
Results: A total of 85 patients were included. The median follow-3up was 15 years. The 20-3year overall survival (OS) and relapse free survival (RFS) were 92% and 96.3%, respectively. No severe acute and late complications were recorded. Overall 5.9% of patients had a second unrelated malignancy.
Conclusion: Adjuvant RT is an efficacious and safe treatment in stage I seminom
Community core detection in transportation networks
This work analyses methods for the identification and the stability under
perturbation of a territorial community structure with specific reference to
transportation networks. We considered networks of commuters for a city and an
insular region. In both cases, we have studied the distribution of commuters'
trips (i.e., home-to-work trips and viceversa). The identification and
stability of the communities' cores are linked to the land-use distribution
within the zone system, and therefore their proper definition may be useful to
transport planners.Comment: 8 pages, 13 figure
Coherent structures in an electron beam
The formation and evolution of coherent structures in a low-energy electron
beam produced in a Malmberg-Penning trap is investigated by means of CCD
diagnostics. The electrons are emitted from a thermionic cathode and their
energy is controlled by an acceleration grid. By varying the spatial
distribution of the energy of emitted electrons, different space charge effects
are observed, as, e. g., a sharp or a gradual transition to a space charge
dominated regime. The variation of the coherent structures along the beam is
studied by varying the electron density or/and the value of the confined
magnetic field. The observed processes are interpreted using a tridimensional
particle-in-cell code which solves the Vlasov-Poisson system in zeroth order
drift approximation.Comment: 12th International Congress on Plasma Physics, 25-29 October 2004,
Nice (France
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