Road expansion and market integration in the Austrian low countries during the second half of the 18th century.

We analyse the integration of wheat markets across 18 towns in the Austrian Low Countries during the second half of the 18th century and the relationship with the rapidly expanding paved road network in this period. We use a switching regression approach (threshold cointegration) to study long-run and short-run integration of these markets, using monthly wheat prices. We find that throughout this period, markets were spatially interconnected. However, price margins adjust only slowly to long-term levels in response to local shocks. We also find that transaction costs are relatively high. The results suggest a complex market with regular trade flow reversals and periods of unprofitable trade between key markets. It is widely accepted in Belgian historiography that the construction of a paved road network caused a substantial reduction in transaction costs. Our research, however, indicates that distance, fixed costs or links by rivers and canals mainly influenced transaction costs, not the expansion of a paved road network. Two factors can account for this. First, the toll structure on paved roads discouraged bulk trade. Secondly, new private investment in inter-city grain trade that may have led to cuts in the trading costs, typically appeared to be absent in this period. However, adjustment speeds in markets are significantly affected by the existence of paved roads. Better communication and faster transport due to the road network resulted in faster arbitrageCountry; Integration; Market; Market integration;

Agricultural extension messages using video on portable devices increase knowledge about seed selection, storage and handling among smallholder potato farmers in southwestern Uganda

Open Access JournalTo feed a growing population, agricultural productivity needs to increase dramatically. Agricultural extension information, with its public, non-rival nature, is generally undersupplied, and public provision remains challenging. In this study, simple agricultural extension video messages, delivered through Android tablets, were tested in the field to determine if they increased farmers’ knowledge of recommended practices on (i) potato seed selection and (ii) seed storage and handling among a sample of potato farmers in southwestern Uganda. Using a field experiment with ex ante matching in a factorial design, it was established that showing agricultural extension videos significantly increased farmers’ knowledge. However, results suggested impact pathways that went beyond simply replicating what was shown in the video. Video messages may have triggered a process of abstraction, whereby farmers applied insights gained in one context to a different context

Electrically controllable saturable absorption in hybrid graphene-silicon waveguides

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50GHz Ge waveguide electro-absorption modulator integrated in a 220nm SOI photonics platform

We report waveguide-integrated Ge electro-absorption modulators operating at 1615nm wavelength with 3dB bandwidth beyond 50GHz and a capacitance of 10fF, A 2V voltage swing enables 4.6dB DC extinction ratio for 4.1dB insertion loss

Demonstration of silicon-on-insulator mid-infrared spectrometers operating at 3.8µm

The design and characterization of silicon-on-insulator mid- infrared spectrometers operating at 3.8µm is reported. The devices are fabricated on 200mm SOI wafers in a CMOS pilot line. Both arrayed waveguide grating structures and planar concave grating structures were designed and tested. Low insertion loss (1.5-2.5dB) and good crosstalk characteristics (15-20dB) are demonstrated, together with waveguide propagation losses in the range of 3 to 6dB/cm

Optical interconnect with densely integrated plasmonic modulator and germanium photodetector arrays

We demonstrate the first chip-to-chip interconnect utilizing a densely integrated plasmonic Mach-Zehnder modulator array operating at 3 x 10 Gbit/s. A multicore fiber provides a compact optical interface, while the receiver consists of germanium photodetectors

Nonlinear optical interactions in silicon waveguides

The strong nonlinear response of silicon photonic nanowire waveguides allows for the integration of nonlinear optical functions on a chip. However, the detrimental nonlinear optical absorption in silicon at telecom wavelengths limits the efficiency of many such experiments. In this review, several approaches are proposed and demonstrated to overcome this fundamental issue. By using the proposed methods, we demonstrate amongst others supercontinuum generation, frequency comb generation, a parametric optical amplifier, and a parametric optical oscillator