The Generation of Direction Selectivity in the Auditory System

Both human speech and animal vocal signals contain frequency-modulated (FM) sounds. Although central auditory neurons that selectively respond to the direction of frequency modulation are known, the synaptic mechanisms underlying the generation of direction selectivity (DS) remain elusive. Here we show the emergence of DS neurons in the inferior colliculus by mapping the three major subcortical auditory nuclei. Cell-attached recordings reveal a highly reliable and precise firing of DS neurons to FM sweeps in a preferred direction. By using in vivo whole-cell current-clamp and voltage-clamp recordings, we found that the synaptic inputs to DS neurons are not direction selective, but temporally reversed excitatory and inhibitory synaptic inputs are evoked in response to opposing directions of FM sweeps. The construction of such temporal asymmetry, resulting DS, and its topography can be attributed to the spectral disparity of the excitatory and the inhibitory synaptic tonal receptive fields

Digital Switching in the Quantum Domain

In this paper, we present an architecture and implementation algorithm such that digital data can be switched in the quantum domain. First we define the connection digraph which can be used to describe the behavior of a switch at a given time, then we show how a connection digraph can be implemented using elementary quantum gates. The proposed mechanism supports unicasting as well as multicasting, and is strict-sense non-blocking. It can be applied to perform either circuit switching or packet switching. Compared with a traditional space or time domain switch, the proposed switching mechanism is more scalable. Assuming an n-by-n quantum switch, the space consumption grows linearly, i.e. O(n), while the time complexity is O(1) for unicasting, and O(log n) for multicasting. Based on these advantages, a high throughput switching device can be built simply by increasing the number of I/O ports.Comment: 24 pages, 16 figures, LaTe

Interacting Two-Time Physics Field Theory With a BRST Gauge Invariant Action

We construct a field theoretic version of 2T-physics including interactions in an action formalism. The approach is a BRST formulation based on the underlying Sp(2,R)gauge symmetry, and shares some similarities with the approach used to construct string field theory. In our first case of spinless particles, the interaction is uniquely determined by the BRST gauge symmetry, and it is different than the Chern-Simons type theory used in open string field theory. After constructing a BRST gauge invariant action for 2T-physics field theory with interactions in d+2 dimensions, we study its relation to standard 1T-physics field theory in (d-1)+1 dimensions by choosing gauges. In one gauge we show that we obtain the Klein-Gordon field theory in (d-1)+1 dimensions with unique SO(d,2) conformal invariant self interactions at the classical field level. This SO(d,2) is the natural linear Lorentz symmetry of the 2T field theory in d+2 dimensions. As indicated in Fig.1, in other gauges we expect to derive a variety of SO(d,2)invariant 1T-physics field theories as gauge fixed forms of the same 2T field theory, thus obtaining a unification of 1T-dynamics in a field theoretic setting, including interactions. The BRST gauge transformation should play the role of duality transformations among the 1T-physics holographic images of the same parent 2T field theory. The availability of a field theory action opens the way for studying 2T-physics with interactions at the quantum level through the path integral approach.Comment: 22 pages, 1 figure, v3 includes corrections of typos and some comment

Was agricultural protection reduced after the Uruguay Round?: Evidence from East Asia

The purpose of this paper is to empirically investigate how agricultural protection has been reduced before/after the implementation of the Uruguay Round Agreement on 1995 in East Asian countries. Our empirical results show that the reduction on agricultural protection in the second half of the 1990s is not outstanding, compared with that in the first half of the 1990s. This result implies that the UR Agreement does not substantially succeed in reducing the protection for agricultural trade in East Asia.

Location Choice of Multinational Enterprises in China: Comparison between Japan and Taiwan

This paper explores the location choice of MNEs in China, shedding special light on the role of agglomeration of same-nationality firms. In particular, we examine how its role differs according to investors’ productivity. Furthermore, we compare the location choice of Japanese and Taiwanese MNEs in China, because Taiwanese MNEs are expected to experience less uncertainty in investing in China than Japanese MNEs, due to Taiwan’s linguistic and cultural advantages in China. We find that, less productive Japanese firms prefer to locate close to larger same-nationality agglomerations, there are no differences in location according to firms’ productivity in the case of Taiwanese firms.

"Estimating the Impact of Whaling on Global Whale Watching"

After the commercial whaling moratorium was enacted in 1986, whale watching became one of the fastest growing tourism industries worldwide. As whaling was regarded as an activity incompatible with whale watching, the possible resumption of commercial whaling caused an urgent need to investigate the potential negative effects of whaling on the whale-watching industry. We examine the potential impacts of whaling on the global whale-watching tourism industry using unbalanced panel data model. The empirical results indicate that the resumption of commercial whaling has the potential for a negative effect on the global whale-watching industry, especially for nations that are engaged in whaling.