Isolating quantum coherence with pathway-selective coherent multi-dimensional spectroscopy

Coherent coupling between spatially separated systems has long been explored as a necessary requirement for quantum information and cryptography. Recent discoveries suggest such phenomena appear in a much wider range of processes, including light-harvesting in photosynthesis. These discoveries have been facilitated by developments in coherent multi-dimensional spectroscopy (CMDS) that allow interactions between different electronic states to be identified in crowded spectra. For complex systems, however, spectral broadening and multiple overlapping peaks limit the ability to separate, identify and properly analyse all contributions. Here we demonstrate how pathway-selective CMDS can overcome these limitations to reveal, isolate and allow detailed analysis of weak coherent coupling between spatially separated excitons localised to different semiconductor quantum wells. Selective excitation of the coherence pathways, by spectrally shaping the laser pulses, provides access to previously hidden details and enables quantitative analysis that can facilitate precise and detailed understanding of interactions in this and other complex systems

The Postjuvenal Wing and Tail Molt of the Ruffed Grouse (Bonasa Umbellus Monticola) in Ohio

Author Institution: Department of Zoology, Ohio University, Athens, OhioBecause feather-replacement patterns influence the validity of aging criteria, 21 captive and 47 wild-trapped Ruffed Grouse from Ohio were studied to determine if their wing and tail molt is comparable to that of more northern races. The results indicate that juvenal primaries numbers 9 and 10 are retained during the first year, but that the progression of wing molt appears to be one to one and one-half weeks slower than that of New York birds. The tail molt occurs about four weeks later than that of New York grouse of comparable age. Differences were not detected in molt timing and pattern between wild and captive birds. Aging keys for chicks between 1 and 18 weeks are adjusted for the apparent slight geographical difference in wing molt rate. The peak hatching period in Ohio is May 15-28, approximately one and one-half weeks earlier than hatching dates reported for Wisconsin

A Unified Approach to High-Gain Adaptive Controllers

It has been known for some time that proportional output feedback will stabilize MIMO, minimum-phase, linear time-invariant systems if the feedback gain is sufficiently large. High-gain adaptive controllers achieve stability by automatically driving up the feedback gain monotonically. More recently, it was demonstrated that sample-and-hold implementations of the high-gain adaptive controller also require adaptation of the sampling rate. In this paper, we use recent advances in the mathematical field of dynamic equations on time scales to unify and generalize the discrete and continuous versions of the high-gain adaptive controller. We prove the stability of high-gain adaptive controllers on a wide class of time scales

Observation of accelerating parabolic beams

We report the first observation of accelerating parabolic beams. These accelerating parabolic beams are similar to the Airy beams because they exhibit the unusual ability to remain diffraction-free while having a quadratic transverse shift during propagation. The amplitude and phase masks required to generate these beams are encoded onto a single liquid crystal display. Experimental results agree well with theory

Proposing the Communicate Bond Belong Theory: Evolutionary intersections with episodic interpersonal communication

The Communicate Bond Belong (CBB) Theory is an evolutionary and motivational explanation of human communication’s role in the relational functions of social interaction. CBB Theory conceives of all social interactions as energy expending, but posits that only some social interactions are striving behaviors (i.e., actions taken to satiate a need). CBB Theory proposes that social interaction operates within a homeostatic system, developed from internal pressures to satiate a need to belong, shaped by competing desires to invest and conserve social energy, and adaptable to new social circumstances and technological affordances. The theory bridges gaps among evolutionary and social psychology theories and interpersonal communication theories by attending to the multifunctional nature of everyday talk in relation to fundamental human needs

Microfluidic actuation by modulation of surface stresses

We demonstrate the active manipulation of nanoliter liquid samples on the surface of a glass or silicon substrate by combining chemical surface patterning with electronically addressable microheater arrays. Hydrophilic lanes designate the possible routes for liquid migration while activation of specific heater elements determine the trajectories. The induced temperature fields spatially modulate the liquid surface tension thereby providing electronic control over the direction, timing, and flow rate of continuous streams or discrete drops. Temperature maps can be programed to move, split, trap, and mix ultrasmall volumes without mechanically moving parts and with low operating voltages of 2–3 V. This method of fluidic actuation allows direct accessibility to liquid samples for handling and diagnostic purposes and provides an attractive platform for palm-sized and battery-powered analysis and synthesis