## Search Constraints

## Search Results

- Creator:
- Saumell, Maria, Medh, Rheem D., Shankar, Deepa B., Fernandez, Silvia, Morris, Devin, Abrego, Bernardo, Hurtado, Ferran, Sakamoto, Kathleen M., Priceman, Saul J., Fabila-Monroy, Ruy, Flores-Penaloza, David, Sacristan, Vera, Kirzner, Jonathan D., and Nary, Laura J.
- Description:
- Let P be a set of n points in the plane. A geometric proximity graph on P is a graph where two points are connected by a straight-line segment if they satisfy some prescribed proximity rule. We consider four classes of higher order proximity graphs, namely, the k-nearest neighbor graph, the k-relative neighborhood graph, the k-Gabriel graph and the k -Delaunay graph. For k=k= (k=1k=1 in the case of the k-nearest neighbor graph) these graphs are plane, but for higher values of k in general they contain crossings. In this paper, we provide lower and upper bounds on their minimum and maximum number of crossings. We give general bounds and we also study particular cases that are especially interesting from the viewpoint of applications. These cases include the 1-Delaunay graph and the k-nearest neighbor graph for small values of k.
- Resource Type:
- Article
- Identifier:
- 0925-7721
- Campus Tesim:
- Northridge

- Creator:
- Yarborough, Jonathan R., Todd, Jennifer, Lee, Lee H., Fernandez, Silvia, Sacristan, Vera, Abrego, Bernardo, Hurtado, Ferran, Perez, Winder, Chu, Tin-Chun, Murray, Sean R., Fabila-Monroy, Ruy, Flores-Penaloza, David, Saumell, Maria, and Okafor, Chiedozie
- Description:
- Resistance to heavy metals is important for the survival of bacteria in contaminated environments. In this study, we show that the unicellular cyanobacterial species Synechococcus sp. IU 625 adapts to growth in the presence of mercuric chloride, recovering from pigmentation and morphological defects. Cells accumulate mercury within two hours of growth and by three days, the total mercury concentration is significantly reduced, with all remaining mercury associated with the cells. This suggests that Synechococcus sp. IU 625 can convert mercury to a volatile form.
- Resource Type:
- Article
- Identifier:
- 0065-1281
- Campus Tesim:
- Northridge

- Creator:
- Meijer, Henk, Flores-Penaloza, David, Fernandez, Silvia, Sacristan, Vera, Abrego, Bernardo, Hurtado, Ferran, Fabila-Monroy, Ruy, and Saumell, Maria
- Description:
- Given a large weighted graph G = (V, E) and a subset U of V , we define several graphs with vertex set U in which two vertices are adjacent if they satisfy some prescribed proximity rule. These rules use the shortest path distance in G and generalize the proximity rules that generate some of the most common proximity graphs in Euclidean spaces. We prove basic properties of the defined graphs and provide algorithms for their computation.
- Resource Type:
- Article
- Identifier:
- http://upcommons.upc.edu/bitstream/handle/2117/8730/proximitygraphsweighted.pdf, 1097-0037
- Campus Tesim:
- Northridge

- Creator:
- Sacristán, Vera, Flores-Peñaloza, David, Saumell, Maria, Fernández-Merchant, Silvia, Ábrego, Bernardo M., Hurtado, Ferran, and Fabila-Monroy, Ruy
- Description:
- Let P be a set of n points in the plane. A geometric proximity graph on P is a graph where two points are connected by a straight-line segment if they satisfy some prescribed proximity rule. We consider four classes of higher order proximity graphs, namely, the k-nearest neighbor graph, the k-relative neighborhood graph, the k-Gabriel graph and the k-Delaunay graph. For ( in the case of the k-nearest neighbor graph) these graphs are plane, but for higher values of k in general they contain crossings. In this paper, we provide lower and upper bounds on their minimum and maximum number of crossings. We give general bounds and we also study particular cases that are especially interesting from the viewpoint of applications. These cases include the 1-Delaunay graph and the k-nearest neighbor graph for small values of k.
- Resource Type:
- Article
- Identifier:
- 0925-7721
- Campus Tesim:
- Northridge