the effect of endogenous serotonin on long-term potentiation (ltp) in region cai was studied by blocking 5-ht2 receptors with ketanserin in rat hippocampal slices. such a block significantly en-hanced long-term potentiation of the cai population spike induced by high frequency stimulation of the schaffer collateral/ commissural pathway. this implies that serotonin acts on 5-ht2 receptors in cai...

purpose: to compare the effects of short-tem and long-term systemic corticosteroids in the treatment of confirmed ocular toxoplasmosis. methods: this randomized comparative clinical trial was performed on 69 patients with confirmed active ocular toxoplasmosis with typical clinical manifestations. the subjects were randomly assigned to receive either 10 days (group a, 33 cases) or 4-6 weeks (gro...

The multivariate regular variation (MRV) is one of the most important tools in modeling multivariate heavy-tailed phenomena. This paper characterizes the MRV distributions through the tail dependence function of the copula associated with them. Along with some existing results, our studies indicate that the existence of the lower tail dependence function of the survival copula is necessary and ...

This paper explains how we have contributed to the development of an open learning infrastructure that manages and makes available Open Educational Resources. By removing friction between people and resources, we can leverage the long tail of learning resources, so that the abundance of learning resources will act as a platform for innovation.

We describe an efficient incentive mechanism for P2P systems that generates a wide diversity of content offerings while responding adaptively to customer demand. Files are served and paid for through a parimutuel market similar to that commonly used for betting in horse races. An analysis of the performance of such a system shows that there exists an equilibrium with a long tail in the distribu...

The Long Tail. The phrase “The Long Tail” was first coined by Chris Anderson in an October 2004 Wired magazine article to describe how our culture and economy is increasingly shifting away from a focus on a relatively small number of “hits” (mainstream products and markets) at the head of the demand curve toward a huge number of niches in the tail (as exemplified by companies such as Amazon or ...

Twitter is often considered to be a useful source of real-time news, potentially replacing newswire for this purpose. But is this true? In this paper, we examine the extent to which news reporting in newswire and Twitter overlap and whether Twitter often reports news faster than traditional newswire providers. In particular, we analyse 77 days worth of tweet and newswire articles with respect t...