Wen-Ching Winnie Li

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Neocortical neurons begin to differentiate soon after they are generated by mitoses at the surface of the ventricular zone (VZ). We provide evidence here that bone morphogenetic protein (BMP) triggers neuronal differentiation of neocortical precursors within the VZ. In cultures of dissociated neocortical neuroepithelial cells, BMPs increase the number of(More)
In this paper we study the distribution of eigenvalues of regular graphs , regular hypergraphs , and biregular bipartite graphs of given girth by considering the polynomials orthogonal with respect to the measures attached to the spectra of such graphs and to the continuous spectra of their ‘universal covers’ . Our estimates are tight for Biggs graphs and(More)
Cycle codes are a special case of low-density parity-check (LDPC) codes and as such can be decoded using an iterative message-passing decoding algorithm on the associated Tanner graph. The existence of pseudo-codewords is known to cause the decoding algorithm to fail in certain instances. In this paper, we draw a connection between pseudo-codewords of cycle(More)
Ternary cyclotomic polynomials are polynomials of the form Φpqr(z) = ∏ ρ(z − ρ), where p < q < r are odd primes and the product is taken over all primitive pqr-th roots of unity ρ. We show that for every p there exists an infinite family of polynomials Φpqr such that the set of coefficients of each of these polynomials coincides with the set of integers in(More)
One approach to defining mechanisms essential to neocortical development is to analyze the phenotype of novel spontaneous mutations that dramatically affect the generation and differentiation of different neocortical neurons. Previously we have shown that there is a large decrease in the total number of cortical neurons in the flathead mutant rat, and in(More)
We describe a new mutation, flathead (fh), that arose spontaneously in an inbred colony of Wistar rats. The mutation is autosomal recessive, and the behavioral phenotype of fh/fh rats includes spontaneous seizures, tremor, impaired coordination, and premature death. A striking feature of the fh mutation is a dramatic reduction in brain size (40% of normal(More)
It is possible to view the combinatorial structures known as (integral) t-designs as Z-modules in a natural way. In this note we introduce a polynomial associated to each such Z-module. Using this association, we quickly derive explicit bases for the important class of submodules which correspond to the so-called null-designs. Introduction. Among the most(More)
An important property of high-performance, low complexity codes is the existence of highly efficient algorithms for their decoding. Many of the most efficient, recent graph-based algorithms, e.g. message passing algorithms and decoding based on linear programming, crucially depend on the efficient representation of a code in a graphical model. In order to(More)
We consider a certain generalization of the hidden number problem introduced by Boneh and Venkatesan in 1996. Considering the XTR variation of Diffie-Hellman, we apply our results to show security of the log p most significant bits of the secret, in analogy to the results known for the classical Diffie-Hellman scheme. Our method is based on bounds of(More)