Preliminary technology utilization assessment of the robotic fruit harvester

The results of an analysis whose purpose was to examine the history and progress of mechanical fruit harvesting, to determine the significance of a robotic fruit tree harvester and to assess the available market for such a product are summarized. Background information that can be used in determining the benefit of a proof of principle demonstration is provided. Such a demonstration could be a major step toward the transfer of this NASA technology

Self-generated and externally driven current oscillations in n-GaAs

Experimental investigations of self-generated and externally driven non-linear current oscillations due to impact ionization of shallow impurities in n-type GaAs at low temperatures are presented. The regular relaxation oscillations which appear at the onset of breakdown are destabilized by a magnetic field normal to the epitaxial layer and multifrequency oscillations and chaotic fluctuations following the Ruelle-Takens-Newhouse scenario can be found. Driving the self-generated oscillations with an external periodic bias voltage quasiperiodicity, mode locking, interaction and overlap of mode locked resonances and period doubling can be observed depending on frequency and amplitude of the external force. The reconstructed return maps, recorded phase diagrams and Devil's staircase agree with theoretical predictions based on the circle map and give new evidence of the universality of the transition from quasiperiodicity to chaos

Next-generation sequencing: applications beyond genomes.

The development of DNA sequencing more than 30 years ago has profoundly impacted biological research. In the last couple of years, remarkable technological innovations have emerged that allow the direct and cost-effective sequencing of complex samples at unprecedented scale and speed. These next-generation technologies make it feasible to sequence not only static genomes, but also entire transcriptomes expressed under different conditions. These and other powerful applications of next-generation sequencing are rapidly revolutionizing the way genomic studies are carried out. Below, we provide a snapshot of these exciting new approaches to understanding the properties and functions of genomes. Given that sequencing-based assays may increasingly supersede microarray-based assays, we also compare and contrast data obtained from these distinct approaches

Immigration and native welfare

We unify two approaches towards identifying native welfare effects of immigration, one emphasizing the immigration surplus (Borjas, 1995,1999), the other identifying a welfare loss due to terms-of-trade effects (Davis & Weinstein, 2002). We decompose the native welfare effect of immigration into the standard complementarity effect, augmented by a Stolper-Samuelson effect, and a terms-of-trade effect. Using a structural model with three skill-classes we derive propositions on the wage and native welfare effects of various immigration scenarios. A calibration-based simulation reveals that the size of the inflow and immigrant income repatriation are key determinants of the welfare-ranking of different immigration scenarios.international migration; factor movements; international trade; non-tradable goods; welfare analysis; wages; general equilibrium; terms-of-trade