Football goal distributions and extremal statistics

We analyse the distributions of the number of goals scored by home teams, away teams, and the total scored in the match, in domestic football games from 169 countries between 1999 and 2001. The probability density functions (PDFs) of goals scored are too heavy-tailed to be fitted over their entire ranges by Poisson or negative binomial distributions which would be expected for uncorrelated processes. Log-normal distributions cannot include zero scores and here we find that the PDFs are consistent with those arising from extremal statistics. In addition, we show that it is sufficient to model English top division and FA Cup matches in the seasons of 1970/71–2000/01 on Poisson or negative binomial distributions, as reported in analyses of earlier seasons, and that these are not consistent with extremal statistics

Dynamics of tournaments: the soccer case

A random walk-like model is considered to discuss statistical aspects of tournaments. The model is applied to soccer leagues with emphasis on the scores. This competitive system was computationally simulated and the results are compared with empirical data from the English, the German and the Spanish leagues and showed a good agreement with them. The present approach enabled us to characterize a diffusion where the scores are not normally distributed, having a short and asymmetric tail extending towards more positive values. We argue that this non-Gaussian behavior is related with the difference between the teams and with the asymmetry of the scores system. In addition, we compared two tournament systems: the all-play-all and the elimination tournaments.Comment: To appear in EPJ

Quantum non-demolition measurement of an electron spin qubit through its low-energy many-body spin environment

The measurement problem dates back to the dawn of quantum mechanics. Here, we measure a quantum dot electron spin qubit through off-resonant coupling with thousands of redundant nuclear spin ancillae. We show that the link from quantum to classical can be made without any "wavefunction collapse", in agreement with the Quantum Darwinism concept. Large ancilla redundancy allows for single-shot readout with high fidelity $\approx99.85\%$. Repeated measurements enable heralded initialization of the qubit and probing of the equilibrium electron spin dynamics. Quantum jumps are observed and attributed to burst-like fluctuations in a thermally populated phonon bath

Approaching a fully-polarized state of nuclear spins in a solid

Magnetic noise of atomic nuclear spins is a major source of decoherence in solid-state spin qubits. In theory, near-unity nuclear spin polarization can eliminate decoherence of the electron spin qubit, while turning the nuclei into a useful quantum information resource. However, achieving sufficiently high nuclear polarizations has remained an evasive goal. Here we implement a nuclear spin polarization protocol which combines strong optical pumping and fast electron tunneling. Nuclear polarizations well above 95% are generated in GaAs semiconductor quantum dots on a timescale of 1 minute. The technique is compatible with standard quantum dot device designs, where highly-polarized nuclear spins can simplify implementations of qubits and quantum memories, as well as offer a testbed for studies of many-body quantum dynamics and magnetism

Generalised joint regression for count data: a penalty extension for competitive settings

We propose a versatile joint regression framework for count responses. The method is implemented in the R add-on package GJRM and allows for modelling linear and non-linear dependence through the use of several copulae. Moreover, the parameters of the marginal distributions of the count responses and of the copula can be specified as flexible functions of covariates. Motivated by competitive settings, we also discuss an extension which forces the regression coefficients of the marginal (linear) predictors to be equal via a suitable penalisation. Model fitting is based on a trust region algorithm which estimates simultaneously all the parameters of the joint models. We investigate the proposal’s empirical performance in two simulation studies, the first one designed for arbitrary count data, the other one reflecting competitive settings. Finally, the method is applied to football data, showing its benefits compared to the standard approach with regard to predictive performance

Hypotheses from mitochondrial DNA: congruence and conflict between DNA sequences and morphology in Dolichopodinae systematics (Diptera : Dolichopodidae)

The molecular phylogeny of the subfamily Dolichopodinae (Diptera : Dolichopodidae) is reconstructed based on 79 species of 7 dolichopodine genera as ingroup, and 10 non-dolichopodine species from different genera as outgroup. A Bayesian analysis based on a mitochondrial DNA dataset consisting of 1702 characters (COI : 810; 12S : 366; 16S : 526) was carried out. Genital and non-genital morphological characters from a hitherto unpublished data matrix (based on 57 Dolichopodidae species) were used to explain and support the lineages hypothesised by our molecular phylogenetic analysis. The monophyly of the subfamily Dolichopodinae, and of the genera Dolichopus and Gymnopternus, was confirmed. The molecular analysis yielded nine species groups in Dolichopus that were proposed in previous studies using COI and Cyt-b. No evidence was found to support a clade including Dolichopus, Ethiromyia, and Gymnopternus. The genus Hercostomus proved polyphyletic with respect to Poecilobothrus, Sybistroma, and Gymnopternus. The following lineages were represented by strongly supported clades: Hercostomus germanus species group, H. vivax species group, H. nigrilamellatus species group, H. plagiatus species group, H. longiventris species group, H. fulvicaudis species group, and Poecilobothrus, Gymnopternus, Tachytrechus and Sybistroma (including Hercostomus nanus and H. parvilamellatus). Two clades that were previously established on the basis of morphology were confirmed in our phylogenetic analysis: (i) Poecilobothrus and the flower-feeding Hercostomus germanus species group, and (ii) the H. longiventris lineage and Sybistroma. In most cases, the groups identified in the molecular analysis could be supported and explained by morphological characters. Species of the Hercostomus germanus species group, Poecilobothrus, the Hercostomus longiventris species group, and a Sybistroma subclade have a similar microhabitat affinity

Increased fecundity of malathion-specific resistant beetles in absence of insecticide pressure

Despite that resistance frequency is assumed to decline when selective pressure is relaxed, the stability of resistance frequency has been observed in some insects in the absence of insecticide. In the red flour beetle, Tribolium castaneum, the first case of malathion-resistance was reported in the early 1960s. The malathion-specific resistant phenotype has now almost completely replaced the susceptible one in red flour beetle populations. In the present study, several life-history traits that could influence the fitness of the insects were compared between insecticide-susceptible and malathion-specific resistant populations of the red flour beetle. On average, egg fertility and egg-to-adult development time did not differ between susceptible and resistant populations. However, the fecundity of resistant females was greater than that of susceptible ones. Generally, differences in development time between insecticide resistant and susceptible populations are considered as having more effect on fitness than do differences in fecundity. However, the observed increased female fecundity may participate, in combination with the previously observed increased male reproductive success, to the development and the stability of malathion-specific resistance in T. castaneum

The Type Locality Of Sciapus pressipes Parent (Diptera, Dolichopodidae)

Volume: 92Start Page: 584End Page: 58