TECHNICAL CHANGE AND AGRICULTURAL TRADE: THREE EXAMPLES (SUGARCANE, BANANAS, AND RICE)

The purpose of this paper is to examine three cases which provide some insight into the character of international transmission of technical change and its economic impacts and implications. These cases focus on three separate commodities, sugarcane, bananas, and rice. Each case presents different facets of the international movement of technological innovation.International Relations/Trade, Research and Development/Tech Change/Emerging Technologies,

Coherent coupling between surface plasmons and excitons in semiconductor nanocrystals

We present an experimental demonstration of strong coupling between a surface plasmon propagating on a planar silver substrate, and the lowest excited state of CdSe nanocrystals. Variable-angle spectroscopic ellipsometry measurements demonstrated the formation of plasmon-exciton mixed states, characterized by a Rabi splitting of $\sim$ 82 meV at room temperature. Such a coherent interaction has the potential for the development of plasmonic non-linear devices, and furthermore, this system is akin to those studied in cavity quantum electrodynamics, thus offering the possibility to study the regime of strong light-matter coupling in semiconductor nanocrystals at easily accessible experimental conditions.Comment: 12 pages, 4 figure

Rotation of visual landmark cues influences the spatial response profile of hippocampal neurons in freely-moving homing pigeons

Pigeon hippocampal neurons display two spatial response profiles: location fields frequently at goals, and path fields connecting goals. We recorded from 15 location and six path cells, with color cues positioned near four goal locations. Following color cue rotation, most location cells (12/15) shifted their response fields; path cells (5/6) lost their fields. Therefore, local visual cues can independently define a reference frame for location cells, but path cells may be more broadly tuned to context or alternative reference frames

Multimodal Perception and Multicriterion Control of Nested Systems

The purpose of this report is to identify the essential characteristics of goal-directed whole-body motion. The report is organized into three major sections (Sections 2, 3, and 4). Section 2 reviews general themes from ecological psychology and control-systems engineering that are relevant to the perception and control of whole-body motion. These themes provide an organizational framework for analyzing the complex and interrelated phenomena that are the defining characteristics of whole-body motion. Section 3 of this report applies the organization framework from the first section to the problem of perception and control of aircraft motion. This is a familiar problem in control-systems engineering and ecological psychology. Section 4 examines an essential but generally neglected aspect of vehicular control: coordination of postural control and vehicular control. To facilitate presentation of this new idea, postural control and its coordination with vehicular control are analyzed in terms of conceptual categories that are familiar in the analysis of vehicular control

Understanding Skill in EVA Mass Handling

Key attributes of skilled mass handling were identified through an examination of lessons learned by the extravehicular activity operational community. These qualities were translated into measurable quantities. The operational validity of the ground-based investigation was improved by building a device that increased the degrees of freedom of extravehicular mobility unit motion on the Precision Air-Bearing Floor. The results revealed subtle patterns of interaction between motions of an orbital replacement unit mockup and mass handler that should be important for effective performance on orbit. The investigation also demonstrated that such patterns can be measured with a variety of common instruments and under imperfect conditions of observation

Higgs ID at the LHC

We make a complete catalog of extended Higgs sectors involving SU(2)_L doublets and singlets, subject to natural flavor conservation. In each case we present the couplings of a light neutral CP-even Higgs state h in terms of the model parameters, and identify which models are distinguishable in principle based on this information. We also give explicit expressions for the model parameters in terms of h couplings and exhibit the behaviors of the couplings in the limit where the deviations from the Standard Model Higgs couplings are small. Finally we discuss prospects for differentiation of extended Higgs models based on measurements at the LHC and ILC and identify the regions in which these experiments could detect deviations from the SM Higgs predictions.Comment: 46 pages, 6 figures, 2 tables, PRD versio

Migrating to Cloud-Native Architectures Using Microservices: An Experience Report

Migration to the cloud has been a popular topic in industry and academia in recent years. Despite many benefits that the cloud presents, such as high availability and scalability, most of the on-premise application architectures are not ready to fully exploit the benefits of this environment, and adapting them to this environment is a non-trivial task. Microservices have appeared recently as novel architectural styles that are native to the cloud. These cloud-native architectures can facilitate migrating on-premise architectures to fully benefit from the cloud environments because non-functional attributes, like scalability, are inherent in this style. The existing approaches on cloud migration does not mostly consider cloud-native architectures as their first-class citizens. As a result, the final product may not meet its primary drivers for migration. In this paper, we intend to report our experience and lessons learned in an ongoing project on migrating a monolithic on-premise software architecture to microservices. We concluded that microservices is not a one-fit-all solution as it introduces new complexities to the system, and many factors, such as distribution complexities, should be considered before adopting this style. However, if adopted in a context that needs high flexibility in terms of scalability and availability, it can deliver its promised benefits

High efficiency GaAs-Ge tandem solar cells grown by MOCVD

High conversion efficiency and low weight are obviously desirable for solar cells intended for space applications. One promising structure is GaAs on Ge. The advantages of using Ge wafers as substrates include the following: they offer high efficiency by forming a two-junction tandem cell; low weight combined with superior strength allows usage of thin (3 mil) wafers; and they are a good substrate for GaAs, being lattice matched, thermal expansion matched, and available as large-area wafers

Gauss Sums and Quantum Mechanics

By adapting Feynman's sum over paths method to a quantum mechanical system whose phase space is a torus, a new proof of the Landsberg-Schaar identity for quadratic Gauss sums is given. In contrast to existing non-elementary proofs, which use infinite sums and a limiting process or contour integration, only finite sums are involved. The toroidal nature of the classical phase space leads to discrete position and momentum, and hence discrete time. The corresponding `path integrals' are finite sums whose normalisations are derived and which are shown to intertwine cyclicity and discreteness to give a finite version of Kelvin's method of images.Comment: 14 pages, LaTe

Truly unentangled photon pairs without spectral filtering

We demonstrate that an integrated silicon microring resonator is capable of efficiently producing photon pairs that are completely unentangled; such pairs are a key component of heralded single photon sources. A dual-channel interferometric coupling scheme can be used to independently tune the quality factors associated with the pump and signal and idler modes, yielding a biphoton wavefunction with Schmidt number arbitrarily close to unity. This will permit the generation of heralded single photon states with unit purity.Comment: 5 pages, 3 figure