A square real matrix is sign-nonsingular if it is forced to be nonsingular by its pattern of zero, negative, and positive entries. We give structural characterizations of sign-nonsingular matrices, digraphs with no even length dicycles, and square nonnegative real matrices whose permanent and determinant are equal. The structural characterizations, which are topological in nature, imply polynom...

We present the case of a patient who developed periorbital ecchymosis (panda sign) following an exacerbation of asthma with severe coughing. There was no history of cranial trauma. Investigations for a structural or haematological cause were negative. The panda sign is typically seen following a base of skull fracture, but rarely reported due to severe coughing.

The question of how to construct polynomials having as many roots as allowed by the Descartes rule of signs has been the focus of interest recently 1],,2]. For a given real polynomial p(x) = a 0 + a 1 x + + a n x n ; Descartes's rule of signs says that the number of positive roots of p(x) is equal to the number of sign changes in the sequence a 0 ; a 1 ; : : : ; a n , or is less than this numbe...

Our recent studies have shown that the dendritic cell-specific ICAM nonintegrin CD209 (DC-SIGN) specifically binds to the core LPS of Escherichia coli K12 (E. coli), promoting bacterial adherence and phagocytosis. In this current study, we attempted to map the sites within the core LPS that are directly involved in LPS-DC-SIGN interaction. We took advantage of four sets of well-defined core LPS...

Background and study aims  The non-extension sign relates to a localized increase in thickness and rigidity due to deep submucosal invasive (SM-d: depth of 1000 μm or more) cancer. The present study aimed to evaluate the efficacy of the non-extension sign in assessing the optical diagnosis of colorectal SM-d cancer. Patients and methods  We retrospectively analyzed 309 patients with 315 early...

BACKGROUND AND PURPOSE The purpose of this study was to assess the effect of postcontrast CT (PCCT) leakage (PCL) on hematoma growth in CTA spot negative patients. METHODS A retrospective study of 61 patients presenting within 6 hours of primary ICH onset imaged with CT angiography (CTA) and PCCT. Presence of CTA spot sign and PCL were documented. PCL was defined as the presence of contrast e...

Dynamics of two-sign point vortices in two-dimensional circular boundary is examined by numerical simulations with MDGRAPE-2. The vortex system is characterized by the inverse temperature beta as determined from the density of states of the microcanonical ensemble of numerically generated 10(7) states. The massive simulation shows that different configurations appear in the time-asymptotic stat...