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Despite the large number of genes known to affect leaf shape or size, we still have a relatively poor understanding of how leaf morphology is established. For example, little is known about how cell division and cell expansion are controlled and coordinated within a growing leaf to eventually develop into a laminar organ of a definite size. To obtain a global perspective of the cellular basis of variations in leaf morphology at the organ, tissue and cell levels, we studied a collection of 111 non-allelic mutants with abnormally shaped and/or sized leaves, which broadly represent the mutational variations in Arabidopsis thaliana leaf morphology not associated with lethality. We used image-processing techniques on these mutants to quantify morphological parameters running the gamut from the palisade mesophyll and epidermal cells to the venation, whole leaf and rosette levels. We found positive correlations between epidermal cell size and leaf area, which is consistent with long-standing Avery's hypothesis that the epidermis drives leaf growth. In addition, venation parameters were positively correlated with leaf area, suggesting that leaf growth and vein patterning share some genetic controls. Positional cloning of the genes affected by the studied mutations will eventually establish functional links between genotypes, molecular functions, cellular parameters and leaf phenotypes.

Multi-hop Cellular Networks using Mobile Relays (MCN-MR) are being studied to overcome certain limitations of traditional single hop cellular systems through the integration of cellular and Peer to Peer (P2P) ad-hoc communications. Current MCN-MR research is generally analytical or simulation based, and there is yet the need for studies that empirically demonstrate the potential of MCN-MR and provide valuable models for the research community. In this context, this paper presents the first 2-hop MCN-MR empirical performance models derived from field tests over live networks. The MCN-MR performance is measured for downlink transmissions as the throughput experienced by mobile users. The model parameters are shown to depend on the distance, Line-Of-Sight (LOS) or Non-LOS (NLOS) conditions, and communication settings of the ad-hoc link. As a result, the paper also reports a set of distance-based empirical P2P link level models.

This paper deals with bankruptcy situations in which in addition to the claims, an exogenously given reference point for the allocation of the estate is present. We introduce and analyse two types of compromise solutions and show that they coincide with the τ value of two corresponding TU games. We apply our solutions to a real-life case of allocating university money to degree courses.

Student Response Systems (SRS) are becoming popular among instructors in nearly all levels of learning. The benefits of using SRSs have been demonstrated in many studies, in terms on attendance, attention, participation, engagement, or motivation. On the other hand, the use of some kind of gaming techniques in education has also been demonstrated in several studies that it is useful to stimulate students to learn in wider, longer, and deeper ways. The study analyze whether the integration of both, SRS and gaming techniques, leads to better results in motivation, attention, engagement and learning performance than only SRS. For this purpose, it has been developed a new tool for conducting an experimental study among students from different subjects and from different academic levels, considering three relevant factors: Learning Tool (nongamificated SRS or gamificated SRS), Study Type and Gender. It has been considered a Multivariate Three-Way Factorial Design. The main finding is that students who took lecture sessions with a gamificated SRS had more positive perceptions with respect to motivation, attention, engagement and learning performance than students who took lecture sessions with a non gamificated SRS.

Heterogeneous wireless systems are characterized by the physical coexistence of a variety of radio access technologies with different, but also complementary, technical characteristics and performance. A key aspect of heterogeneous systems is then the implementation of efficient joint radio resource management mechanisms. In this context, this paper presents and evaluates novel joint radio resource management techniques based on the CEA bankruptcy distribution rule. The proposed policies base their distribution decisions on the system conditions and the varying quality of service requirements present in multimedia scenarios. The obtained results demonstrate that the proposed policies can efficiently distribute the radio resources with a low computational cost.

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