Outcomes of CCAFS Work in Vietnam

The study explored how CCAFS SEA outputs have helped the country achieve its development outcomes in the agricultural sector. The assessment showed that CCAFS SEA, although still on-going, has contributed to specific outcomes in Vietnam, which include changes in knowledge, approaches, practices, and strategies related to climate change, particularly in the agricultural sector. These outcomes were observed among decision makers, policymakers, technical staff, and farmers

Semi-groups, groups and Lyapunov stability of partial differential equations

Applications of group theory and Liapunov stability to partial differential equation

The Effects of Arousal Induction on Infants\u27 Tempo Preferences

Previous research has demonstrated that infants have a natural preference to listen to fast temporal sequences over intermediate temporal sequences (Steffler, 2012, unpublished thesis). The present study seeks to explore whether or not infant tempo preferences are context-dependent, specifically examining the effect of arousal levels on tempo preferences. In the current study, 6- to 8-month-old infants\u27 preference for tempo was evaluated using a head-turn preference procedure, following an arousal induction phase, in which the infants\u27 environment was altered with the aim of lowering their physiological arousal. Infants showed a significant 3-way interaction between side of presentation, first stimulus presentation, and tempo

Information based clustering

In an age of increasingly large data sets, investigators in many different disciplines have turned to clustering as a tool for data analysis and exploration. Existing clustering methods, however, typically depend on several nontrivial assumptions about the structure of data. Here we reformulate the clustering problem from an information theoretic perspective which avoids many of these assumptions. In particular, our formulation obviates the need for defining a cluster "prototype", does not require an a priori similarity metric, is invariant to changes in the representation of the data, and naturally captures non-linear relations. We apply this approach to different domains and find that it consistently produces clusters that are more coherent than those extracted by existing algorithms. Finally, our approach provides a way of clustering based on collective notions of similarity rather than the traditional pairwise measures.Comment: To appear in Proceedings of the National Academy of Sciences USA, 11 pages, 9 figure

Coupled Two-Way Clustering Analysis of Gene Microarray Data

We present a novel coupled two-way clustering approach to gene microarray data analysis. The main idea is to identify subsets of the genes and samples, such that when one of these is used to cluster the other, stable and significant partitions emerge. The search for such subsets is a computationally complex task: we present an algorithm, based on iterative clustering, which performs such a search. This analysis is especially suitable for gene microarray data, where the contributions of a variety of biological mechanisms to the gene expression levels are entangled in a large body of experimental data. The method was applied to two gene microarray data sets, on colon cancer and leukemia. By identifying relevant subsets of the data and focusing on them we were able to discover partitions and correlations that were masked and hidden when the full dataset was used in the analysis. Some of these partitions have clear biological interpretation; others can serve to identify possible directions for future research

Laser pulse annealing of ion-implanted GaAs

GaAs single-crystals wafers are implanted at room temperature with 400-keV Te + ions to a dose of 1×10^15 cm^–2 to form an amorphous surface layer. The recrystallization of this layer is investigated by backscattering spectrometry and transmission electron microscopy after transient annealing by Q-switched ruby laser irradiation. An energy density threshold of about 1.0 J/cm^2 exists above which the layer regrows epitaxially. Below the threshold the layer is polycrystalline; the grain size increases as the energy density approaches threshold. The results are analogous to those reported for the elemental semiconductors, Si and Ge. The threshold value observed is in good agreement with that predicted by the simple model successfully applied previously to Si and Ge