3,932 research outputs found
Binomial Ideals and Congruences on Nn
Producción CientíficaA congruence on Nn is an equivalence relation on Nn that is compatible with the additive structure. If k is a field, and I is a binomial ideal in k[X1,…,Xn] (that is, an ideal generated by polynomials with at most two terms), then I induces a congruence on Nn by declaring u and v to be equivalent if there is a linear combination with nonzero coefficients of Xu and Xv that belongs to I. While every congruence on Nn arises this way, this is not a one-to-one correspondence, as many binomial ideals may induce the same congruence. Nevertheless, the link between a binomial ideal and its corresponding congruence is strong, and one may think of congruences as the underlying combinatorial structures of binomial ideals. In the current literature, the theories of binomial ideals and congruences on Nn are developed separately. The aim of this survey paper is to provide a detailed parallel exposition, that provides algebraic intuition for the combinatorial analysis of congruences. For the elaboration of this survey paper, we followed mainly (Kahle and Miller Algebra Number Theory 8(6):1297–1364, 2014) with an eye on Eisenbud and Sturmfels (Duke Math J 84(1):1–45, 1996) and Ojeda and Piedra Sánchez (J Symbolic Comput 30(4):383–400, 2000).National Science Foundation (grant DMS-1500832)Ministerio de Economía, Industria y Competitividad (project MTM2015-65764-C3-1)Junta de Extremadura (grupo de investigación FQM-024
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THE COYOLXAUHQUI PROCESS OF A SCHOLAR UNBECOMING AN ENEMY OF YOUTH: A PERFORMATIVE, EMBODIED, SELF-DECOLONIZING STORY OF TRANSFORMATION AND HOPE
Scholarly work may be used to foster colonizing processes upon people of color whether scholars are aware of it or not. That is the case of the study of youth bullying in the United States, an old issue that, however, became a central social concern in the United States in the late 1990s. Building upon scholars’ framing of youth bullying, a combination of moral panics on youth unfolded, fostering a law-and-order regime in schools that expanded the application of zero-tolerance policies. These policies fed the school-to-prison pipeline that funnels youth into the criminal justice system, a form of internal colonization that polices, incarcerates, and exploits youth of color in the United States. As a researcher on youth bullying, I was oblivious to this harmful outcome. I was becoming an enemy of youth of color and I committed to unbecoming one, using this dissertation for that purpose. First, by tracing the genealogy of the study of youth bullying and how academic premises became Gramscian common sense. Second, by reflecting upon and redressing my complicity with (neo)colonialism. I use performance x autoethnography and Anzaldúa’s Coyolxauhqui imperative as methods to unfold a self decolonizing process as a Canary Islander and queer diasporic nepantlera who is a colonize(d)(r) scholar. The new conocimiento that I obtain in this process allows me to look at the study of youth bullying with a different gaze. As a result, I offer an alternative onto-epistemological and methodological approach to the study of youth bullying in the United States. I advocate for a collective decolonizing reframing of youth bullying based upon centering youth’s agency, challenging adult researchers’ standpoint, suggesting other onto-epistemological and conceptual approaches, as well as promoting other values and tactics in the study of youth peer abuse and violence. This dissertation, in sum, is an onto-epistemo-methodological embodied reflection that offers a methodological contribution on how to study youth bullying in less colonizing ways. Likewise, it contributes to methodological conversations on how to use performance autoethnography to self-decolonize as well as how to decolonize performance autoethnography. Moreover, this text contributes to better understanding diasporic experience and expands the literature on the Canarian diaspora. Fundamentally, this dissertation contributes to decolonizing academia
Living Within Opaque Worlds: The Balkanized Experiences of Collegiate Minority Student-Athletes
A long-term study yielded recommendations for college-wide policies to enhance mainstreaming and ameliorate against institutional balkanization of minority student-athletes
NOTEWORTHY BIRD RECORDS IN SONTECOMAPAN, VERACRUZ, MEXICO
Registramos observaciones sobresalientes de aves en el sur del estado de Veracruz. Se reporta la tercera localidad donde se ha registrado la polluela pechigris (Laterallu sexilis) para el país, el primer registro para el estado del rascón cuello rufo (Aramides axillaris), el segundo registro de colimbo mayor (Gavia immer) para el sur del estado, así como el registro de una pareja de hocofaisanes (Crax rubra) en el área de manglar de Sontecomapan
Time dependence of soil water hysteresis in a minesoil reclaimed by sewage sludge amendments
Postprint (published version
Evolution of the largest mammalian genome
The genome of the red vizcacha rat (Rodentia, Octodontidae, Tympanoctomys barrerae) is the largest of all mammals, and about double the size of their close relative, the mountain vizcacha rat Octomys mimax, even though the lineages that gave rise to these species diverged from each other only about five million years ago. The mechanism for this rapid genome expansion is controversial, and hypothesized to be a consequence of whole genome duplication or accumulation of repetitive elements. To test these alternative but nonexclusive hypotheses, we gathered and evaluated evidence from whole transcriptome and whole genome sequences of T. barrerae and O. mimax. We recovered support for genome expansion due to accumulation of a diverse assemblage of repetitive elements, which represent about one half and one fifth of the genomes of T. barrarae and O. mimax, respectively, but we found no strong signal of whole genome duplication. In both species, repetitive sequences were rare in transcribed regions as compared to the rest of the genome, and mostly had no close match to annotated repetitive sequences from other rodents. These findings raise new questions about the genomic dynamics of these repetitive elements, their connection to widespread chromosomal fissions that occurred in the T. barrerae ancestor, and their fitness effects ? including during the evolution of hypersaline dietary tolerance in T. barrerae.Fil: Evans, Ben J.. Mc Master University; CanadáFil: Upham, Nathan S.. Mc Master University; Canadá. Field Museum of Natural History; Estados Unidos. University of Yale; Estados UnidosFil: Golding, G. Brian. Mc Master University; CanadáFil: Ojeda, Ricardo Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Argentino de Investigaciones de las Zonas Áridas. Provincia de Mendoza. Instituto Argentino de Investigaciones de las Zonas Áridas. Universidad Nacional de Cuyo. Instituto Argentino de Investigaciones de las Zonas Áridas; ArgentinaFil: Ojeda, Agustina Alejandra. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Argentino de Investigaciones de las Zonas Áridas. Provincia de Mendoza. Instituto Argentino de Investigaciones de las Zonas Áridas. Universidad Nacional de Cuyo. Instituto Argentino de Investigaciones de las Zonas Áridas; Argentin
Soil shapes community structure through fire
7 páginas, 2 figuras, 2 tablas.Recurrent wildWres constitute a major selecting force in shaping the structure of plant communities. At the regional scale, Wre favours phenotypic and phylogenetic
clustering in Mediterranean woody plant communities.
Nevertheless, the incidence of Wre within a Wre-prone region may present strong variations at the local, landscape scale. This study tests the prediction that woody communities on acid, nutrient-poor soils should exhibit more pronounced phenotypic and phylogenetic clustering patterns
than woody communities on fertile soils, as a consequence of their higher Xammability and, hence, presumably higher propensity to recurrent Wre. Results conWrm the predictions
and show that habitat Wltering driven by Wre may be detected even in local communities from an already Wre-Wltered regional Xora. They also provide a new perspective from which to consider a preponderant role of Wre as a key evolutionary force in acid, infertile Mediterranean heathlands.This work has been partially supported by
projects VAMPIRO (CGL2008-05289-C02-01/BOS) and PERSIST (CGL2006-07126/BOS), Wnanced by the Spanish Ministerio de Ciencia e Innovación, and project P07-RNM-02869, Wnanced by the Junta de Andalucía regional government (Spain). Fieldwork was carried out under permission and complied with legal requirements of the Andalusian regional government.Peer reviewe
Application of multivariate statistical analysis to assess browning bsusceptibility in sweet potatoes (Ipomoea batatas (l.) Lam.) cultivars, based on chemical and enzymatic determinations
The selection of a sweet potato cultivar for minimal processing must be performed considering the nutritional value and the lower susceptibility to browning development, which will result in greater stability of the vegetable colour. The aim of this work was to evaluate browning susceptibility in four sections of two sweet potato cultivars combining chemical and enzymatic determinations with colour variables, by applying multivariate statistical techniques. Each cultivar had a characteristic browning pattern; in white cultivar colour changes were represented by changes in variable b* while in the red cultivar these changes responded to variations in variable a*.The regions with major colour changes (ΔE*>6) after 24 hours also had high levels of phenolic compounds (658±98 mg chlorogenic acid/kg fresh tissue) and high oxidative enzymes activities. Principal Component Analysis indicated that three regions in white cultivar and two in red cultivar had low browning susceptibility. Partial Least Square analysis indicated that colour changes (ΔE*) were highly associated with Polyphenoloxidase activity and phenolic compounds. By comparing both cultivars analyzed, the white cultivar presented 3 regions with low browning susceptibility and therefore would be more suitable for minimally processing.
This low susceptibility would be related to low phenol content and lower enzyme activities.Centro de Investigación y Desarrollo en Criotecnología de Alimentos (CIDCA)Facultad de Ciencias Agrarias y Forestales (FCAF
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