Row Reduction of Macaulay Matrices

A computer can use a matrix to represent a system of non-linear multivariate polynomial equations. The fastest known ways to transform this system into a form with desirable computational properties rely on transforming its matrix into upper-triangular form [8, 9]. The matrix for such a system will have mostly zero entries, which we call sparse [7]. We propose to analyze several methods of performing row-reduction, the process by which matrices are reduced into upper-triangular form [2]. What is special about row-reducing matrices in this context? When row-reducing a matrix, swapping rows or columns is typically acceptable. However, if the order of the terms in the polynomials must be preserved as in nonlinear systems, swapping columns of its matrix would be unacceptable. Another thing to consider is the “almost” upper-triangular structure of these matrices. Therefore, we want to adapt methods of performing row-reduction to allow swapping rows but not columns and perform the least amount of additions and multiplications

Borders traversed, boundaries erected: Creating discursive identities and language communities in the Village of Tewa

Today the Village of Tewa, First Mesa of the Hopi Reservation in Northern Arizona experiences unprecedented linguistic diversity and change due to language shift to English. Despite a wide range of speaker fluency, the now emblematic Tewa language that their ancestors transported from the Rio Grande Valley almost 325 years ago, is widely valorized within the community. However Language factions have emerged andtheir debates and contestations focus on legitimate language learning and the proper maintenance of their emblematic language. Boundary creation and crossing are featuresof discourses that rationalize possible forms of language revitalization and construct communities across temporal barriers. The theoretical implications of these discourseson both local and theoretical notions of language/speech community are explored. © 2014 Elsevier Ltd. All rights reserved

The native shrub, Piliostigma reticulatum , as an ecological “resource island” for mango trees in the Sahel

African farmers are increasingly adopting sustainable agricultural practices including use of native shrub intercropping approaches. In one village of Sénégal (near Thiès) it was reported that farmers planted mango (Mangifera indica) seedlings within the canopies of a native shrub (Piliostigma reticulatum). Anecdotal information and qualitative observations suggested that the presence of P. reticulatum promoted soil quality and a competitive advantage for establishing mango plantations. We hypothesized that soil chemical and microbial properties of mango rhizosphere soil growing in the presence of P. reticulatum would be significantly improved over soils associated with mango growing outside the influence of P. reticulatum. The results showed that mango-shrub interplanting significantly lowered pH, and increased arbuscular mycorrhizal fungi (AMF) colonization of mango roots, enzyme activities, and microbial biomass compared to mango alone. Phylogenetic analyses by PCR-denaturing gradient gel electrophoresis (DGGE) showed that community structures of fungi, bacteria, and bacterial genes responsible for denitrification (nirK) of the soil from the rooting zone of the mango-shrub intercropping system were distinct from all other soil outside the influence of P. reticulatum. It is concluded that P. reticulatum enhances soil biological functioning and that there is a synergistic effect of intercropping mango with the native shrub, P. reticulatum, in soil quality with a more diverse community, greater AMF infection rates, and greater potential to perform decomposition and mineralize nutrients

Agroforesterie et services écosystémiques en zone tropicale

Respectueux de l’environnement et garantissant une sécurité alimentaire soutenue par la diversification des productions et des revenus qu’ils procurent, les systèmes agroforestiers apparaissent comme un modèle prometteur d’agriculture durable dans les pays du Sud les plus vulnérables aux changements globaux. Cependant, ces systèmes agroforestiers ne peuvent être optimisés qu’à condition de mieux comprendre et de mieux maîtriser les facteurs de leurs productions. L’ouvrage présente un ensemble de connaissances récentes sur les mécanismes biophysiques et socio-économiques qui sous-tendent le fonctionnement et la dynamique des systèmes agroforestiers. Il concerne, d’une part les systèmes agroforestiers à base de cultures pérennes, telles que cacaoyers et caféiers, de régions tropicales humides en Amérique du Sud, en Afrique de l’Est et du Centre, d’autre part les parcs arborés et arbustifs à base de cultures vivrières, principalement de céréales, de la région semi-aride subsaharienne d’Afrique de l’Ouest. Il synthétise les dernières avancées acquises grâce à plusieurs projets associant le Cirad, l’IRD et leurs partenaires du Sud qui ont été conduits entre 2012 et 2016 dans ces régions. L’ensemble de ces projets s’articulent autour des dynamiques des systèmes agroforestiers et des compromis entre les services de production et les autres services socio-écosystémiques que ces systèmes fournissent

As the Rez Turns: Anomalies within and beyond the Boundaries of a Pueblo Community

After initial instruction in written and spoken Tiwa, young adult participants in the summer language program at San Antonio Pueblo began authoring their own pedagogical materials as a learning activity. Charged with writing pedagogical dialogues to aid in language learning, the students created “the first Native soap opera,” as the students described it, which they named As the Rez Turns. In this paper, I analyze the processes of entextualization surrounding the creation of this text, its generic features, and its content, which provides a glimpse into the contemporary lived experience of community members in this community that emphasizes strict control of textual circulation and limiting access to local knowledge. I utilize Philip Deloria’s (2004) analysis of Native Americans’ engagement with popular cultural forms, and linguistic anthropological work on intertextuality and genre to analyze this example of representation, outlining the extra- and intracommunity generic and ideological “expectations” conditioning the creation of this dialogue to show how the students utilize associated “anomalies” as discursive resources to construct veiled political commentaries and assert the right to author indigenous language materials. By including stylistic and thematic elements outside of and in dialogue with the standard forms of pedagogical language dialogues and contemporary soap operas among other genres, the final text is an example of the ways that indigenous people continue to “creat[e] modernity in dialogue with others” (Deloria 2004:238). Pueblo language ideologies privileging indirection are honored in the creation of this covert political commentary supposedly created as a neutral language learning tool. Thus, As the Rez Turns is an example of a comedy of manners, highlighting membership issues, gender, and indigenous identity in this community

Aw Snap!

Lacrosse players and parents know that equipment such as sticks, are pricey. Our project will help prevent lacrosse shafts form breaking during practice or a game. The solution that we decided on will add more support to the shaft to help prevent it from bending and warping which can lead to the lacrosse shaft breaking. the solution is a pole that has triangle supports on the sides and added walls on the inside of the pole that will allow for more support. The pole will go inside the lacrosse shaft to be able to give support

Fitness Cost of Aflatoxin Production in Aspergillus flavus When Competing with Soil Microbes Could Maintain Balancing Selection

Aflatoxin, produced by the fungus Aspergillus flavus, is an extremely potent hepatotoxin that causes acute toxicosis and cancer, and it incurs hundreds of millions of dollars annually in agricultural losses. Despite the importance of this toxin to humans, it has remained unclear what the fungus gains by producing aflatoxin. In fact, not all strains of A. flavus produce aflatoxin. Previous work has shown an advantage to producing aflatoxin in the presence of some insects. Our current work demonstrates the first evidence of a disadvantage to A. flavus in producing aflatoxin when competing with soil microbes. Together, these opposing evolutionary forces could explain the persistence of both aflatoxigenic and nonaflatoxigenic strains through evolutionary time.Selective forces that maintain the polymorphism for aflatoxigenic and nonaflatoxigenic individuals of Aspergillus flavus are largely unknown. As soils are widely considered the natural habitat of A. flavus, we hypothesized that aflatoxin production would confer a fitness advantage in the soil environment. To test this hypothesis, we used A. flavus DNA quantified by quantitative PCR (qPCR) as a proxy for fitness of aflatoxigenic and nonaflatoxigenic field isolates grown in soil microcosms. Contrary to predictions, aflatoxigenic isolates had significantly lower fitness than did nonaflatoxigenic isolates in natural soils across three temperatures (25, 37, and 42°C). The addition of aflatoxin to soils (500 ng/g) had no effect on the growth of A. flavus. Amplicon sequencing showed that neither the aflatoxin-producing ability of the fungus nor the addition of aflatoxin had a significant effect on the composition of fungal or bacterial communities in soil. We argue that the fitness disadvantage of aflatoxigenic isolates is most likely explained by the metabolic cost of producing aflatoxin. Coupled with a previous report of a selective advantage of aflatoxin production in the presence of some insects, our findings give an ecological explanation for balancing selection resulting in persistent polymorphisms in aflatoxin production

Magnitude of Genotype × Environment Interactions Affecting Tomato Fruit Quality

There is a growing interest by consumers to purchase fresh tomatoes with improved quality traits including lycopene, total soluble solids (TSS), vitamin C, and total titratable acid (TTA) content. As a result, there are considerable efforts by tomato breeders to improve tomato for these traits. However, suitable varieties developed for one location may not perform the same in different locations. This causes a problem for plant breeders because it is too labor-intensive to develop varieties for each specific location. The objective of this study was to determine the extent of genotype x environment (GxE) interaction that influences tomato fruit quality. To achieve this objective, we grew a set of 42 diverse tomato genotypes with different fruit shapes in replicated trials in three locations: North Carolina, New York, and Ohio. Fruits were harvested at the red ripe stage and analyzed for lycopene, TSS, vitamin C, and TTA.Analysis of variance (ANOVA) revealed that there were significant differences (P was 16%, whereas that for TTA was 87%. The extent of G·E interaction found for fruit quality traits in the tomato varieties included in this study may be useful in identifying optimal locations for future field trials by tomato breeders aiming to improve tomato fruit quality.Fil: Panthee, Dilip R.. North Carolina State University; Estados UnidosFil: Cao, Chunxue. Ohio State University; Estados UnidosFil: Debenport, Spencer J.. Ohio State University; Estados UnidosFil: Rodríguez, Gustavo Rubén. Ohio State University; Estados Unidos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Investigaciones en Ciencias Agrarias de Rosario. Universidad Nacional de Rosario. Facultad de Ciencias Agrarias. Instituto de Investigaciones en Ciencias Agrarias de Rosario; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Humanidades. Universidad Nacional de Córdoba. Instituto de Humanidades; ArgentinaFil: Labate, Joanne A.. United States Department of Agriculture. Agricultural Research Service; ArgentinaFil: Robertson, Larry D.. United States Department of Agriculture. Agricultural Research Service; ArgentinaFil: Breksa, Andrew P.. United States Department of Agriculture. Agricultural Research Service; ArgentinaFil: van der Knaap, Esther. Ohio State University; Estados UnidosFil: McSpadden Gardener, Brian B.. Ohio State University; Estados Unido