In this short paper we study the existence of positive and negative semide nite solutions of the algebraic Riccati equation corresponding to linear quadratic problems with an inde nite cost functional. An important role is played by certain two-variable polynomial matrices associated with the algebraic Riccati equation. We characterize al unmixed solutions in terms of the Pick matrices associat...

Management factors affect nutrient loss during animal manure slurry storage in different ways. We conducted a pilot-scale study to evaluate carbon (C) and nitrogen (N) losses from unseparated and digested dairy slurry during winter and summer storage. In addition to season, treatments included mechanical separation of digestate into liquid and solid fractions and bimonthly mixing. Chemical anal...

Abstract Raman spectroscopy is a valuable tool for non-destructive vibrational analysis of chemical compounds in various samples. Through 2D scanning, it one can map the surface distribution heterogeneous sample. These hyperspectral images typically contain spectra pure that are hidden within thousands sum spectra. Inspecting each spectrum to find dataset impractical, and several algorithms hav...

In some production settings, beef bulls are mixed at the beginning of the finishing period to obtain homogeneous groups to facilitate finishing and to produce more homogeneous carcasses. Given the stress induced by mixing, we questioned whether this practice was profitable. Sixty-four young bulls were finished in groups of four over 8 mo. They were either mixed or unmixed and had either homogen...

An in vitro model has been devised so that mixtures of human tumor cells can be grown together for studies related to drug-induced or -selected changes in sensitivity. In the studies reported here, two human astrocytoma clones, one sensitive and one resistant to l-(2-i-hIorocthyl)3-(4-methylcyclohexyI)-l-mrrosourea (MeCCNU), were carefully matched for doubling times, cell cycle phase distributi...

Identification of positive staining is often qualitative and subjective. This is particularly troublesome in pigmented melanoma lesions, because melanin is difficult to distinguish from the brown stain resulting from immunohistochemistry (IHC) using horse radish peroxidase developed with 3,3'-Diaminobenzidine (HRP-DAB). We sought to identify and quantify positive staining, particularly in melan...