A Statistical Model to Explain the Mendel--Fisher Controversy

In 1866 Gregor Mendel published a seminal paper containing the foundations of modern genetics. In 1936 Ronald Fisher published a statistical analysis of Mendel's data concluding that "the data of most, if not all, of the experiments have been falsified so as to agree closely with Mendel's expectations." The accusation gave rise to a controversy which has reached the present time. There are reasonable grounds to assume that a certain unconscious bias was systematically introduced in Mendel's experimentation. Based on this assumption, a probability model that fits Mendel's data and does not offend Fisher's analysis is given. This reconciliation model may well be the end of the Mendel--Fisher controversy.Comment: Published in at http://dx.doi.org/10.1214/10-STS342 the Statistical Science (http://www.imstat.org/sts/) by the Institute of Mathematical Statistics (http://www.imstat.org

Optimal diffusion in ecological dynamics with Allee effect in a metapopulation

How diffusion impacts on ecological dynamics under the Allee effect and spatial constraints? That is the question we address. Employing a microscopic minimal model in a metapopulation (without imposing nonlinear birth and death rates) we evince --- both numerically and analitically --- the emergence of an optimal diffusion that maximises the survival probability. Even though, at first such result seems counter-intuitive, it has empirical support from recent experiments with engineered bacteria. Moreover, we show that this optimal diffusion disappears for loose spatial constraints.Comment: 16 pages; 6 figure

Lorentz invariance for mixed neutrinos

We show that a proper field theoretical treatment of mixed (Dirac) neutrinos leads to non-trivial dispersion relations for the flavor states. We analyze such a situation in the framework of the non-linear relativity schemes recently proposed by Magueijo and Smolin. We finally examine the experimental implications of our theoretical proposals by considering the spectrum and the end-point of beta decay in tritium.Comment: 8 pages, 4 figures. Presented at 2nd International Workshop DICE2004: From Decoherence and Emergent Classicality to Emergent Quantum Mechanics, Castello di Piombino, Tuscany, Italy, 1-4 Sep 200

New housing supply: what do we know and how can we learn more?

This paper reviews the literature on new housing supply. The paper starts by summarizing the results of the empirical studies on housing supply, showing that overall these studies reject the hypothesis of a perfectly elastic housing supply and reveal that housing supply is negatively related with financial costs, inflation and sales delay while showing inconclusive results with respect to the construction costs. In addition, we review a recent branch of the literature on housing supply that uses strategic interaction models. There is evidence that the housing market is not well described by the perfect competition model. Thus, a deeper understanding of housing supply can be achieved by considering theoretical models that take into account the strategic interaction between land developers and by using data where the unit of analysis is the land developer.Housing supply; price elasticity of supply, strategic interaction.

Use of geographical and socio-economical information to support the risk assessment of foot and mouth disease in the frontier between Brazil and Paraguay

ln 2001, Brazil was able to eliminate the outbreaks of Foot and Mouth Disease (FMD) in bovine herds. After that, meat exports had an increase of 200%. However, in September 2005 occurred a FMD outbreak in the State of Mato Grosso do Sul (MS) and Parana, and then, not only them, but also other states, lost the status of the "FMD free zone with vaccination" and they were forbidden to export meat to other countries. According ta Gazeta Mercantil Journal (2005) the loss related to the return of the FMD disease in Mato Grosso do Sul, reached US$ 1.5 billion, due to commercial restriction of meat exportations. Only in July, 2008, after three years of the outbreak, Mato Grosso do Sul was considered free with vaccination by the World Organization for Animal Health (OIE). Because of the different production systems, socio-economical conditions and geographieal eharaeteristie over the State of Mato Grosso do Sul, which has one of the Brazilian's biggest bovine herd (20-million heads) working on FMD risk assessment of FMD involves to address the problematic with an holistie approach. The aim of the Ph.D. project is to analyze the potential use of geographical informations as weil as geospatial tools (maps, satellite images) and use with OTAG decisional support system to make risk assessment of FMD. Two experimental eounties in the state of Mato Grosso do Su 1 in the frontier between Brazi 1 and Paraguay eonsidered by the Brazi 1ian Government a high surveillance region for FMD disease were seleeted. Production praetiees and their specifie geographieal eharaeteristies (land cover, land use, infrastructure, etc.) will be studied with the use of Landsat 5 satellite images and field survey. Soeio-eeonomical, sanitary and animal movements data for eaeh eounty will be analysed. The researeh will also involve a temporal analysis, based on the evolution of the territories and human practices, the aetual picture of these counties, regarding the 2005 FMD outbreak. Ali the parameters will be analyzed in order to develop a methodology to determine and improve deeisional ind ieators that wi Il have potentia 1 issue for FMD risk assessment. (Texte intégral

Global and regional source attribution of Shiga toxin-producing Escherichia coli infections using analysis of outbreak surveillance data

Shiga toxin-producing Escherichia coli (STEC) infections pose a substantial health and economic burden worldwide. To target interventions to prevent foodborne infections, it is important to determine the types of foods leading to illness. Our objective was to determine the food sources of STEC globally and for the six World Health Organization regions. We used data from STEC outbreaks that have occurred globally to estimate source attribution fractions. We categorised foods according to their ingredients and applied a probabilistic model that used information on implicated foods for source attribution. Data were received from 27 countries covering the period between 1998 and 2017 and three regions: the Americas (AMR), Europe (EUR) and Western-Pacific (WPR). Results showed that the top foods varied across regions. The most important sources in AMR were beef (40%; 95% Uncertainty Interval 39-41%) and produce (35%; 95% UI 34-36%). In EUR, the ranking was similar though with less marked differences between sources (beef 31%; 95% UI 28-34% and produce 30%; 95% UI 27-33%). In contrast, the most common source of STEC in WPR was produce (43%; 95% UI 36-46%), followed by dairy (27%; 95% UI 27-27%). Possible explanations for regional variability include differences in food consumption and preparation, frequency of STEC contamination, the potential of regionally predominant STEC strains to cause severe illness and differences in outbreak investigation and reporting. Despite data gaps, these results provide important information to inform the development of strategies for lowering the global burden of STEC infections

Invisible Z decay width bounds on active-sterile neutrino mixing in the (3+1) and (3+2) models

In this work we consider the standard model extended with singlet sterile neutrinos with mass in the eV range and mixed with the active neutrinos. The active-sterile neutrino mixing renders new contributions to the invisible Z decay width which, in the case of light sterile neutrinos, depends on the active-sterile mixing matrix elements only. We then use the current experimental value of the invisible Z decay width to obtain bounds on these mixing matrix elements for both (3+1) and (3+2) models.Comment: 10 pages, 5 figure

NNLO predictions for Z-boson pair production at the LHC

We present a calculation of the NNLO QCD corrections to Z-boson pair production at hadron colliders, based on the N-jettiness method for the real radiation parts. We discuss the size and shape of the perturbative corrections along with their associated scale uncertainties and compare our results to recent LHC data at $\sqrt{s}=13$ TeV.Comment: 19 pages, 2 Tables, 4 figures. Version to appear in JHE