Distance-based kernels for real-valued data

We consider distance-based similarity measures for real-valued vectors of interest in kernel-based machine learning algorithms. In particular, a truncated Euclidean similarity measure and a self-normalized similarity measure related to the Canberra distance. It is proved that they are positive semi-definite (p.s.d.), thus facilitating their use in kernel-based methods, like the Support Vector Machine, a very popular machine learning tool. These kernels may be better suited than standard kernels (like the RBF) in certain situations, that are described in the paper. Some rather general results concerning positivity properties are presented in detail as well as some interesting ways of proving the p.s.d. property.Peer ReviewedPostprint (author's final draft

Las Matemáticas y sus aplicaciones, ayer y hoy: Retos del futuro

Los científicos han sabido desde hace siglos que las matemáticas forman, junto con el método experimental, el esquema conceptual en que se basa la ciencia moderna y en el que se apoya la tecnología. En la presente sociedad de la información, el esquema se ha ampliado y está formado por experimentos, matemáticas y computación. Tras siglos de vivir una vida más o menos discreta, parece que con el último siglo ha llegado la edad de oro: nadie duda hoy día de la importancia de las matemáticas en la educación, en la ciencia, en la industria, y también en las más variadas actividades sociales, como son los mundos de la economía y las finanzas, la ecología, la climatología, la medicina, o el fascinante mundo de la image

Existencia, unicidad y propiedades de algunas ecuaciones en derivadas parciales semilineales

Tesis inédita de la Universidad Complutense de Madrid, Facultad de Ciencias Matemáticas, leída en 1979.Fac. de Ciencias MatemáticasTRUEProQuestpu

The Potosí principle: religious prosociality fosters selforganization of larger commnities under extreme natural and economic conditions

We show how in colonial Potosı´ (present-day Bolivia) social and political stabil-ity was achieved through the self-organization of society through the repetition of religious rituals. Our analysis shows that the population of Potosı´ develops over the time a series of cycles of rituals and miracles as a response to social upheaval and natural disasters and that these cycles of religious performance become crucial mechanisms of cooperation among different ethnic and religious groups. Our methodology starts with a close reading and annotation of the Historia de Potosı´ by Bartolome´ Arzans. Then, we model the religious cycles of miracles and rituals and store all social and cultural information about the cycles in a multirelational graph database. Finally, we perform graph analysis through traversals queries in order to establish facts concerning social networks, historical evolution of behaviors, types of participation of miraculous characters according to dates, parts of the city, ethnic groups, etc. It is also important to note that the religious activity at the group level gave native communities a way to participate in the social life. It also guaranteed that the city performed its role as producer of silver in the global economic structure of the Spanish empire. This case proves the importance of religion as a mechanism of stability and self-organization in periods of social or political turbulence. The multidisciplinary methodology combining traditional humanistic techniques with graph analysis shows a great potential for other sociological, historical, and literary problems

Influence of grain processing in regard to serum metabolites and enzymes for finishing bull calves

This study compared two grain processing methods that are widely used for beef cattle, grinding and steam pelleting, with respect to serum metabolic parameters: glucose, non-esterified fatty acids (NEFA), serum urea nitrogen (SUN), total serum protein (TSP), albumin, L-lactate, aspartate aminotransferase (AST), γ-glutamyltransferase (GGT) and amylase. Ten Belgian Blue bull calves were allotted randomly to each of two experimental groups: PF, fed pelleted concentrate, and GF, fed ground concentrate. During the 77-day study most parameters underwent significant variation in time, increasing only numerically serum values of total protein, albumin, AST and amylase, while serum glucose, NEFA and GGT decreased numerically. Statistically significant differences were found only between groups PF and GF for creatinine (higher in group PF, in relation with its greater average body weight) and urea nitrogen, which for unknown causes fluctuated in opposite directions in the two groups throughout most of the study and attributable to changes in ruminal protein digestion. Neither serum glucose nor L-lactate were affected by treatment of grainsSupported by the Xunta de Galicia (Spain), Grant XUGA 2002/CG320S

Cerebral changes and disrupted gray-matter cortical networks in asymptomatic older adults at risk for Alzheimer's disease

The diagnostic value of cerebrospinal fluid (CSF) biomarkers is well established in Alzheimer's disease, but our current knowledge about how abnormal CSF levels affect cerebral integrity, at local and network levels, is incomplete in asymptomatic older adults. Here, we have collected CSF samples and performed structural magnetic resonance imaging scans in cognitively normal elderly as part of a cross-sectional multicenter study (SIGNAL project). To identify group differences in cortical thickness, white matter volume, and properties of structural networks, participants were split into controls (N = 20), positive amyloid-? (A?1?42 +) (N = 19), and positive phosphorylated tau (N = 18). The A?1?42 + group exhibited thickening of middle temporal regions, while positive phosphorylated tau individuals showed thinning in the superior parietal and orbitofrontal cortices. Subjects with abnormal CSF biomarkers further showed regional white matter atrophy and more segregated cortical networks, the A?1?42 + group showing heightened isolation of cingulate and temporal cortices. Collectively, these findings highlight the relevance of combining structural brain imaging and connectomics for in vivo tracking of Alzheimer's disease lesions in asymptomatic stages.This work was supported by research grants from the Spanish Ministry of Economy and Competitiveness (SAF2011-25463 to J.L.C., PSI2014-55747-R to M.A.), the Carlos III Institute of Health, Spain (PI11/02425 and PI14/01126 to J.F.; PI11/3035 and PI14/1561 to A.L.; PI08/0139, PI12/02288 and PI16/01652 to P.S.J.), jointly funded by Fondo Europeo de Desarrollo Regional (FEDER), Unión Europea, “Una manera de hacer Europa”, the Joint Programming in Neurodegenerative Disease Research (DEMTEST to P.S.J.), “Marató TV3” (project 20141210 to J.F. and 20142610 to A.L.), the Regional Ministry of Innovation, Science and Enterprise, Junta de Andalucia (P12- CTS-2327 to J.C.L.), and the CIBERNED program (Signal project)

Medium-sided games in soccer: Physical and heart rate demands throughout successive working periods

This research compared the physical and heart rate demands of three medium-sided games with the same number of players per team (six) but different playing areas throughout four successive working periods. The two games played in relatively larger areas (large and medium) were performed with regular goals and goalkeepers, so the most reduced game (short) was performed without goals. Nine professional soccer players participated in this study. Meaningful differences were found (p<0.05) on the physical demands in the three proposals, with higher values for the games performed on larger areas: maximum speed: 22.8±2.4, 19.8±2.3, and 17.6±1.8 Km/h; and distance covered/min: 120.5±13.4, 103.4±11.2, and 93.8±11.6 m/min in large, medium and short game respectively. There were no differences on the heart rate responses among them. When the physical demands were analysed during the four working periods, the differences could only be seen in large game (p<0.05). The first periods in this proposal showed higher values in distance covered/min, maximum speed, and distance/h in the speed zones 7.0-12.9, 13.0-17.9, and 18.0-20.9 Km/h, and lower values in the zones 0-6.9 Km/h, demonstrating, throughout the periods, the tendency to reduce the distance at high speed and to increase the distance at lower speed. These changes in the activity patterns, related to the period of exercising, could depend on the dimensions of the playing field, thus showing a possible effect of fatigue only in those games played in relative higher areas