Animals have a remarkable ability to track dynamic sensory information. For example, the nematode Caenorhabditis elegans can locate a diacetyl odor source across a 100,000-fold concentration range. Here, we relate neuronal properties, circuit implementation, and behavioral strategies underlying this robust navigation. Diacetyl responses in AWA olfactory neurons are concentration and history dep...

A recent publication reports a series of findings demonstrating a network of inhibitory connections between antennal lobe glomeruli in the Drosophila olfactory system. These connections include a GABA-mediated presynaptic inhibition that suppresses transmitter release from olfactory receptor neuron terminals. This presynaptic inhibition is organized on an interglomerular basis, such that the in...

A tentative list of ecological attributes; diversity, cycling, stability and capacity, is proposed for quantification and ranking of farming systems along a hypothetical scale of increasing ecological sustainability. The modelling and preliminary analysis of four rice-based systems from the Philippines, two on-station experimental systems and two smallholder farms, confirms our intuitive percep...

There is a growing demand for sharing information across multiple autonomous and private databases. The problem is usually formulated as a secure multiparty computation problem where a set of parties wish to jointly compute a function of their private inputs such that the parties learn only the result of the function but nothing else. In this paper we analyze existing and potential solutions fo...

Background: Conventional cattle ranching and agricultural practices have severely degraded and fragmented tropical forests in Latin America. This trend has resulted in the loss of a range of ecosystem services upon which humans depend, especially those that support agricultural production, such as biodiversity, the provision of water and soil fertility. Consequently, conventional cattle ranchin...

Although two classes of shares on the same Chinese companies differ only in that the A-share class trade in Yuan and the B-share class in dollars, the B-shares have traded at a significant and persistent discounts to the A-shares since inception of the B-share market in the early 1990s. The persistence of the discount has been a puzzle. We find that liquidity differences between the less liquid...

abstract the objective of this study is to investigate the long run and short run interactions between agricultural trade liberalization and shares of the two sectors of agriculture and services in the total export and import products and services of iran during the years 1961-2008. to figure out interactions, the vector correction model was used. the ratio of the sum of imports and exports to ...

This paper investigates the impacts of cotton marketing reforms on farm productivity, a key element for poverty alleviation, in rural Zambia. The reforms comprised the elimination of the Zambian cotton marketing board that was in place since 1977. Following liberalization, the sector adopted an outgrower scheme, whereby firms provided extension services to farmers and sold inputs on loans that ...

This article analyzes direct and indirect effects of foreign ownership on productivity in the Turkish manufacturing plants between 1990 and 1996. First, based on Olley-Pakes production function estimates, foreign affiliates are shown to be more productive than local plants. Using sectoral output shares of foreign affiliates and 1990 input-output matrix to identify linkages across plants, regres...

The impact of trade liberalization on productivity and economic growth has received considerable attention in recent policy debates (for recent review, see Tybout, 2000 and 2001, Epifani, 2003, Erdem and Tybout, 2003). To start with, there is no consensus in the theoretical literature on the impact of trade reform on productivity. Some researchers claim that trade openness might improve product...