University of Kansas

About: University of Kansas is a education organization based out in Lawrence, Kansas, United States. It is known for research contribution in the topics: Population & Poison control. The organization has 38183 authors who have published 81381 publications receiving 2986312 citations. The organization is also known as: KU & Univ of Kansas.

A complex oscillating network of signaling genes underlies the mouse segmentation clock.

Abstract: The segmental pattern of the spine is established early in development, when the vertebral precursors, the somites, are rhythmically produced from the presomitic mesoderm. Microarray studies of the mouse presomitic mesoderm transcriptome reveal that the oscillator associated with this process, the segmentation clock, drives the periodic expression of a large network of cyclic genes involved in cell signaling. Mutually exclusive activation of the notch-fibroblast growth factor and Wnt pathways during each cycle suggests that coordinated regulation of these three pathways underlies the clock oscillator.

I-TASSER: fully automated protein structure prediction in CASP8.

Abstract: The I-TASSER algorithm for protein 3D structure prediction was tested in CASP8, with the procedure fully automated in both the Server and Human sections. The quality of the server models is close to that of human ones but incorporating more diverse templates from other servers improves the results of human predictions in the distant homology category. For the first time, the sequence-based contact predictions from machine learning techniques are found helpful for both template-based modeling (TBM) and template-free modeling (FM). In TBM, although the average accuracy of the sequence-based contact predictions is lower than that from template-based ones, the novel contacts in the sequence-based predictions, which are complementary to the threading templates in the weakly or unaligned regions, are important to improve the global and local packing of these regions. Moreover, the newly developed atomic structural refinement algorithm was tested in CASP8 and found to improve the hydrogen-bonding networks and the overall TM-score, which is mainly due to its ability of removing steric clashes so that the models can be generated from cluster centroids. Nevertheless, one of the major issues of the I-TASSER pipeline is the model selection where the best models could not be appropriately recognized when the correct templates are detected only by the minority of the threading algorithms. There are also problems related with domain-splitting and mirror image recognition which mainly influences the performance of I-TASSER modeling in the FM-based structure predictions.

Atomic and electronic reconstruction at the van der Waals interface in twisted bilayer graphene

Abstract: Control of the interlayer twist angle in two-dimensional van der Waals (vdW) heterostructures enables one to engineer a quasiperiodic moire superlattice of tunable length scale1–8. In twisted bilayer graphene, the simple moire superlattice band description suggests that the electronic bandwidth can be tuned to be comparable to the vdW interlayer interaction at a ‘magic angle’9, exhibiting strongly correlated behaviour. However, the vdW interlayer interaction can also cause significant structural reconstruction at the interface by favouring interlayer commensurability, which competes with the intralayer lattice distortion10–16. Here we report atomic-scale reconstruction in twisted bilayer graphene and its effect on the electronic structure. We find a gradual transition from an incommensurate moire structure to an array of commensurate domains with soliton boundaries as we decrease the twist angle across the characteristic crossover angle, θc ≈ 1°. In the solitonic regime (θ < θc) where the atomic and electronic reconstruction become significant, a simple moire band description breaks down and the secondary Dirac bands appear. On applying a transverse electric field, we observe electronic transport along the network of one-dimensional topological channels that surround the alternating triangular gapped domains. Atomic and electronic reconstruction at the vdW interface provide a new pathway to engineer the system with continuous tunability. An investigation of the structural and transport properties of bilayer graphene as a function of the twist angle between the layers reveals atomic-scale reconstruction for twist angles smaller than a critical value.

The Circumstances and Legal Consequences of Non‐GAAP Reporting: Evidence from Restatements*

Abstract: Our study examines the circumstances of non-GAAP financial reporting by 492 U.S. companies that announced restatements from 1995 to 1999. We focus on income statements to analyze the occurrence and resolution of litigation over restatements and explore the role of accounting items in bringing and resolving this litigation. We provide evidence on the pervasiveness of accounting misstatements, describe their nature, and show how, if at all, they affect litigation. We assess the nature of restatements by determining whether regular, recurring earnings from primary operations (core) or other components of earnings (noncore) are misstated, and we assess their pervasiveness by estimating the number of primary accounts misstated. In our sample, companies with core restatements have higher frequencies of intentional misstatements (fraud) and subsequent bankruptcy or delisting. Likewise, these companies have, on average, more material misstatements, more negative security price reactions to restatement announcements, and more negative security price changes over the six months preceding and following restatement announcements. However, controlling for these and other factors, we find a significant association between accounting items and litigation, whether occurrences or resolutions. Specifically, core restatements — driven primarily by misstatements of revenue, a component of core earnings — and more pervasive restatements each play a role, while misstatements of noncore earnings alone do not.