Mobility unevenness in rock-paper-scissors models

We investigate a tritrophic system whose cyclic dominance is modelled by the rock-paper-scissors game. We consider that organisms of one or two species are affected by movement limitations, which unbalances the cyclic spatial game. Performing stochastic simulations, we show that mobility unevenness controls the population dynamics. In the case of one slow species, the predominant species depends on the level of mobility restriction, with the slow species being preponderant if the mobility limitations are substantial. If two species face mobility limitations, our outcomes show that being higher dispersive does not constitute an advantage in terms of population growth. On the contrary, if organisms move with higher mobility, they expose themselves to enemies more frequently, being more vulnerable to being eliminated. Finally, our findings show that biodiversity benefits in regions where species are slowed. Biodiversity loss for high mobility organisms, common to cyclic systems, may be avoided with coexistence probability being higher for robust mobility limitations. Our results may help biologists understand the dynamics of unbalanced spatial systems where organisms' dispersal is fundamental to biodiversity conservation.Comment: 7 pages, 7 figure

Characterization in bi-parameter space of a non-ideal oscillator

The authors thank scientific agencies CAPES, CNPq (112952/2015-1), and FAPESP (2011/ 19269-11). M. S. Baptista also thanks EPSRC (EP/I03 2606/1).Peer reviewedPostprin

Spatial organisation plasticity reduces disease infection risk in rock-paper-scissors models

We study a three-species cyclic game system where organisms face a contagious disease whose virulence may change by a pathogen mutation. As a responsive defence strategy, organisms' mobility is restricted to reduce disease dissemination in the system. The impact of the collective self-preservation strategy on the disease infection risk is investigated by performing stochastic simulations of the spatial version of the rock-paper-scissors game. Our outcomes show that the mobility control strategy induces plasticity in the spatial patterns with groups of organisms of the same species inhabiting spatial domains whose characteristic length scales depend on the level of dispersal restrictions. The spatial organisation plasticity allows the ecosystems to adapt to minimise the individuals' disease contamination risk if an eventual pathogen alters the disease virulence. We discover that if a pathogen mutation makes the disease more transmissible or less lethal, the organisms benefit more if the mobility is not strongly restricted, thus forming large spatial domains. Conversely, the benefits of protecting against a pathogen causing a less contagious or deadlier disease are maximised if the average size of groups of individuals of the same species is significantly limited, reducing the dimensions of groups of organisms significantly. Our findings may help biologists understand the effects of dispersal control as a conservation strategy in ecosystems affected by epidemic outbreaks.Comment: 8 pages, 8 figure

Do BCS National Championships Lead to Recruiting Violations? A Trend Analysis of NCAA Division I (FBS) Infractions

With the NCAA suggesting increased severity of sanctions for NCAA rules violators (Wieberg, 2008), an area of great concern to athletic directors is the institution’s violation of Article 13 of NCAA Division I legislation while recruiting prospective student-athletes. While researchers state that NCAA violations are on the rise (Mahony,1999; Jordan, Greenwell, Geist, Pastore, & Mahony, 2004), very little research has been conducted to ascertain the number of NCAA recruiting violations committed, and by whom. The purpose of this study was to describe the nature of recruiting violations, including major and secondary violations, conference affiliation of institutions committing major violations, then to analyze major recruiting violations of Division I Football Bowl Subdivision (FBS) institutions. A trend analysis was conducted by examining the frequency and distribution of NCAA major infractions from 1970 to 2007, with a specific focus major recruiting infractions from 1987 through the current construct of the Division I-A (Football Bowl Subdivision) conference structure of 2007. The results of this analysis provide athletic administrators with regional and sport-specific findings regarding major recruiting infractions. It also informs athletic compliance directors of focal points and monitoring strategies based upon sport, region, and conference in am effort to curtail future NCAA recruiting violations

Sampling system for wheat (Triticum aestivum L) area estimation using digital LANDSAT MSS data and aerial photographs

A procedure to estimate wheat (Triticum aestivum L) area using sampling technique based on aerial photographs and digital LANDSAT MSS data is developed. Aerial photographs covering 720 square km are visually analyzed. To estimate wheat area, a regression approach is applied using different sample sizes and various sampling units. As the size of sampling unit decreased, the percentage of sampled area required to obtain similar estimation performance also decreased. The lowest percentage of the area sampled for wheat estimation with relatively high precision and accuracy through regression estimation is 13.90% using 10 square km as the sampling unit. Wheat area estimation using only aerial photographs is less precise and accurate than those obtained by regression estimation