Testing Sparsity Assumptions in Bayesian Networks

Bayesian network (BN) structure discovery algorithms typically either make assumptions about the sparsity of the true underlying network, or are limited by computational constraints to networks with a small number of variables. While these sparsity assumptions can take various forms, frequently the assumptions focus on an upper bound for the maximum in-degree of the underlying graph $\nabla_G$. Theorem 2 in Duttweiler et. al. (2023) demonstrates that the largest eigenvalue of the normalized inverse covariance matrix ($\Omega$) of a linear BN is a lower bound for $\nabla_G$. Building on this result, this paper provides the asymptotic properties of, and a debiasing procedure for, the sample eigenvalues of $\Omega$, leading to a hypothesis test that may be used to determine if the BN has max in-degree greater than 1. A linear BN structure discovery workflow is suggested in which the investigator uses this hypothesis test to aid in selecting an appropriate structure discovery algorithm. The hypothesis test performance is evaluated through simulations and the workflow is demonstrated on data from a human psoriasis study

A dynamic programming algorithm for the optimal control of piecewise deterministic Markov processes

Publisher's version/PDFA piecewise deterministic Markov process (PDP) is a continuous time Markov process consisting of continuous, deterministic trajectories interrupted by random jumps. The trajectories may be controlled with the object of minimizing the expected costs associated with the process. A method of representing this controlled PDP as a discrete time decision process is presented, allowing the value function for the problem to be expressed as the fixed point of a dynamic programming operator. Decisions take the form of trajectory segments. The expected costs may then be minimized through a dynamic programming algorithm, rather than through the solution of the Bellman–Hamilton–Jacobi equation, assuming the trajectory segments are numerically tractable. The technique is applied to the optimal capacity expansion problem, that is, the problem of planning the construction of new production facilities to meet rising demand

Capitulacion y concordia hecha, pactada y concordada por y entre los ... habitadores de la villa de Almudebar de una parte, y sus censalistas, acrehedores y personas nombradas de la otra, por la paga y solucion de las pensiones de censales sobre dicha villa cargadas ... hasta por todo el año de mil seyscientos y treynta y cinco

Tít. tomado de p. 1 y menc. de resp. de p. 16En p. 16 texto fechado en letra en 1627Sign.: A\p8\

Ivermectina al 1 %. Ensayo a campo en la sarna psoroptica ovina

How to check, in field conditions the acaricide action of Ivermectina 1% of Psoroptes comunis var. ovis; 47 sheep of different age, weight and both sexes, presenting a high degree of parasite infestation and with large injured body areas, 36 were medicated on three different levels of dosage, as follow: 300 mcg/KPV single dose, 600 mcg/KPV single dose and 300 mcg/KPV double dose, administered in two doses given with 10 days’ interval 11 sheep were untreated control. From the three levels tested the second proved to be the most effective: 600 mcg/KPV single dose, subcutaneous in the interthight. The double dose was also effective but the animals treated were more sensitive to relapses during the development of the experience. It should be noted the acaricide effect of the product, the absence side effects and the ease of administration just as the disadvantages for medicating it accurately. In spite of effectiveness checked, it should not be overlooked the necessary precautions for avoiding relapses and/or new parasitic infestations.A los efectos de comprobar, en condiciones de campo, la acción acaricida de la Ivermectina al 1 % sobre el Psoroptes communis var. ovis; 47 ovinos de diferente edad, peso y ambos sexos, que presentaban alto grado de infestación parasitaria y con amplias regiones corporales lesionadas, 36 fueron medicados a 3 niveles distintos de dosis, a saber: única de 300 mcg/KPV microgramos por Kilo de Peso Vivo); única de 600 mcg/KPV y doble de 300 mcg/KPV repartidos en dos aplicaciones con diez días de intervalo entre una y otra; 11 ovinos se dejaron como testigos. De los tres niveles ensayados resultó más efectivo el segundo, 600 mcg/KPV, en dosis única, subcutánea en la entrepierna. También fue eficaz la dosis doble de 300 mcg/KPV pero los animales tratados fueron más sensibles a las recidivas en las condiciones en que se desarrolló Ia experiencia. Se destaca el efecto acaricida del producto. La ausencia de efectos colaterales y secundarios y la comodidad de aplicación, así como los inconvenientes para dosificarlo correctamente. A pesar de la efectividad comprobada no deben obviarse los recaudos necesarios para evitar recidivas y/o nuevas infestaciones parasíticas

Estimation of effective number of breeders from molecular coancestry of single cohort sample

The effective population size, Ne, is an important parameter in population genetics and conservation biology. It is, however, difficult to directly estimate Ne from demographic data in many wild species. Alternatively, the use of genetic data has received much attention in recent years. In the present study, I propose a new method for estimating the effective number of breeders Neb from a parameter of allele sharing (molecular coancestry) among sampled progeny. The bias and confidence interval of the new estimator are compared with those from a published method, i.e. the heterozygote-excess method, using computer simulation. Two population models are simulated; the noninbred population that consists of noninbred and nonrelated parents and the inbred population that is composed of inbred and related parents. Both methods give essentially unbiased estimates of Neb when applied to the noninbred population. In the inbred population, the proposed method gives a downward biased estimate, but the confidence interval is remarkably narrowed compared with that in the noninbred population. Estimate from the heterozygote-excess method is nearly unbiased in the inbred population, but suffers from a larger confidence interval. By combining the estimates from the two methods as a harmonic mean, the reliability is remarkably improved

Igualdades y desigualdades laborales: estructura empresarial en dos cadenas de alimentación. Mercadona y Simply.

El eje de nuestro trabajo se centra en un estudio sobre las igualdades y desigualdades en el mundo de la empresa, centradonos en dos grandes organizaciones, como son Mercadona y Simply

Efficient maximum likelihood pedigree reconstruction

A simple and efficient algorithm is presented for finding a maximum likelihood pedigree using microsatellite (STR) genotype information on a complete sample of related individuals. The computational complexity of the algorithm is at worst (O(n32n)), where n is the number of individuals. Thus it is possible to exhaustively search the space of all pedigrees of up to thirty individuals for one that maximizes the likelihood. A priori age and sex information can be used if available, but is not essential. The algorithm is applied in a simulation study, and to some real data on humans

On Approximating Four Covering and Packing Problems

In this paper, we consider approximability issues of the following four problems: triangle packing, full sibling reconstruction, maximum profit coverage and 2-coverage. All of them are generalized or specialized versions of set-cover and have applications in biology ranging from full-sibling reconstructions in wild populations to biomolecular clusterings; however, as this paper shows, their approximability properties differ considerably. Our inapproximability constant for the triangle packing problem improves upon the previous results; this is done by directly transforming the inapproximability gap of Haastad for the problem of maximizing the number of satisfied equations for a set of equations over GF(2) and is interesting in its own right. Our approximability results on the full siblings reconstruction problems answers questions originally posed by Berger-Wolf et al. and our results on the maximum profit coverage problem provides almost matching upper and lower bounds on the approximation ratio, answering a question posed by Hassin and Or.Comment: 25 page

Caprine toxoplasmosis in Salta province, Argentina

La toxoplasmosis, causada por Toxoplasma gondii, es una zoonosis que produce pérdidas reproductivas en rumiantes. Este trabajo caracterizó la presencia indirecta, a través de anticuerpos, de la enfermedad en caprinos de la provincia de Salta a través de una encuesta en 39 unidades productoras (UP). Se tomaron muestras biológicas para el diagnóstico de enfermedades en la que fue incluida toxoplasmosis. En un análisis el promedio provincial de UP con animales positivos fue del 79,49% y la seroprevalencia media de los hatos fue 19,09% con valores entre 2,8 y 78,13% siendo más frecuentes valores menores del 20%. Se detectaron UP positivas en toda la provincia con los siguientes promedios de UP con animales positivos: Chaco Salteño (CS)=84,62%, Quebradas Áridas (QA)=72,72%, Valles Templados (VT)=80,00%. La seroprevalencia en los hatos osciló entre CS=3,50-20,00%, QA=2,80-42,00% y VT=6,25-78,13%, encontrándose anticuerpos contra T. gondii presentes en todas ecorregiones evaluadas de la provincia de Salta.Toxoplasmosis, caused by Toxoplasma gondii, is a zoonosis that causes reproductive losses in ruminants. This work characterised indirectly (by detecting antibodies) the disease presence in goats from Salta province through a survey in 39 production units (PU). Biological samples were taken for a disease screening in which toxoplasmosis was included. The provincial average of positives PU was 79.49% and the average herd serum prevalence was 19.09% with values ranging between 2.8 y 78.13%, being more frequent values smaller than 20%. Positive PU were detected in all the provinces with the following averages of PU with positives animals: Saltean Chaco (SC)= 84.62%, Arid Ravines (AR)= 72.72%, Temperate Valleys (TV) = 80.00%. The ranges of seroprevalence were: CS= 3.50-20.00%, QA= 2.80-42.00% and VT= 6.25-78.13%. Antibodies against T. gondii were found in all the ecoregions of Salta province included in our study.Instituto de Investigación Animal Chaco SemiaridoFil: Dodero, Ana Mariela. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Investigación Animal del Chaco Semiárido; ArgentinaFil: Bertoni, Emiliano Agustín. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Investigación Animal del Chaco Semiárido; ArgentinaFil: Cortez, Hector Sergio. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Investigación Animal del Chaco Semiárido; ArgentinaFil: Salatin, Antonio Omar. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Investigación Animal del Chaco Semiárido; ArgentinaFil: Martinez Almudevar, Fabián Carlos. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Salta. Oficina de Información Técnica Coronel Moldes; ArgentinaFil: Gos, María Laura. Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias. Laboratorio de Inmuno-parasitología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Suarez, Victor Humberto. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Investigación Animal Chaco Semiarido; Argentin