We apply combinatorial arguments to establish structural constraints on Costas arrays. We prove restrictions on when a Costas array can contain a large corner region whose entries are all 0. In particular, we prove a 2010 conjecture due to Russo, Erickson and Beard. We then constrain the vectors joining pairs of 1s in a Costas array by establishing a series of results on its number of “mirror p...

In this paper we test two hypotheses regarding magical thinking about the perceived likelihood of future events. The first is that people believe that those who “tempt fate” by failing to take necessary precautions are more likely to suffer negative outcomes. The second is the “protection effect”, where reminding people of precautions they have taken leads them to see related risks as less like...

Abstract Monoon liukiuense (Annonaceae) is an endangered tree species distributed in Iriomote Island and Hateruma the Ryukyu (Nansei) Islands, Japan, Orchid (Lanyu) Taiwan. While its habitat confined to small areas surrounded by human-altered landscapes, matured trees bear abundant fruits, many offspring grow under mother trees. M. hypothesised have lost effective seed dispersers. To test this ...

Seed banking remains a cornerstone in the conservation of plant genetic resources. To be successful, it relies on the collecting and banking of high-quality seeds. In 1995 there was relatively little guidance available to seed collectors (especially of wild plant species), who had to make decisions in the field about what to collect and how to handle collected material. Since then, research int...

—Pocket gophers have the potential to alter the dynamics of grasslands by creating mounds that bury existing vegetation and locally reset succession. Gopher mounds may provide safe sites for less competitive species, potentially increasing both species diversity and vegetation heterogeneity (spatial variation in species composition). We compared species composition, diversity and heterogeneity ...

Use of improved seeds has a vital role in enhancing agricultural production. Agriculture extension has implemented farmers’ managed seed multiplication program at the community level to ensure efficient supply of improved seeds. Several success and failure cases of seed multiplication through farmers' organizations were experienced. Therefore, a case study was conducted in the western terai reg...

Immigration rates of species into communities are widely understood to influence community diversity, which in turn is widely expected to influence the susceptibility of ecosystems to species invasion. For a given community, however, immigration processes may impact diversity by means of two separable components: the number of species represented in seed inputs and the density of seed per speci...

The success or failure of many organisms to respond to the challenges of habitat destruction and a warming climate lies in the ability of plant species to disperse between isolated habitats or to migrate to new ranges. European semi-natural grasslands represent one of the world’s most species-rich habitats at small scales, but agricultural intensification during the 20th century has meant that ...

Formation of the coronary vessels is a fundamental event in heart development. Congenital abnormalities in the coronary system can have major deleterious effects on heart function. It is also possible that subtle variation in the patterning of coronary vessels has significant but uncharacterized effects on myocardial structure and function. In addition, generation of the coronary vascular syste...