Effect of data scaling on color device model fitting

Output devices in print production can be characterized by different characterization methods. One commonly used method of color device characterization is least squares fitting. In essence, the least squares fitting is used to determine the coefficients of a predetermined polynomial, such that the sum of squared differences between the values predicted by the model and the empirical data is minimal. The choice of the polynomial order and the cross product terms which best describe the behavior of a certain device is not obvious. This paper is a part of a larger study which investigates the criteria in the measurement data which can be used for optimal model selection. The part of the study covered in this paper addresses the data over fitting problem. It is investigated by comparing the performance of models of different polynomial orders on two different domains.Peer Reviewe

Effect of data scaling on color device model fitting

Output devices in print production can be characterized by different characterization methods. One commonly used method of color device characterization is least squares fitting. In essence, the least squares fitting is used to determine the coefficients of a predetermined polynomial, such that the sum of squared differences between the values predicted by the model and the empirical data is minimal. The choice of the polynomial order and the cross product terms which best describe the behavior of a certain device is not obvious. This paper is a part of a larger study which investigates the criteria in the measurement data which can be used for optimal model selection. The part of the study covered in this paper addresses the data over fitting problem. It is investigated by comparing the performance of models of different polynomial orders on two different domains

Effect of data scaling on color device model fitting

Output devices in print production can be characterized by different characterization methods. One commonly used method of color device characterization is least squares fitting. In essence, the least squares fitting is used to determine the coefficients of a predetermined polynomial, such that the sum of squared differences between the values predicted by the model and the empirical data is minimal. The choice of the polynomial order and the cross product terms which best describe the behavior of a certain device is not obvious. This paper is a part of a larger study which investigates the criteria in the measurement data which can be used for optimal model selection. The part of the study covered in this paper addresses the data over fitting problem. It is investigated by comparing the performance of models of different polynomial orders on two different domains.Peer Reviewe

Hemoglobin vesicles improve wound healing and tissue survival in critically ischemic skin in mice

Local hypoxia, as due to trauma, surgery, or arterial occlusive disease, may severely jeopardize the survival of the affected tissue and its wound-healing capacity. Initially developed to replace blood transfusions, artificial oxygen carriers have emerged as oxygen therapeutics in such conditions. The aim of this study was to target primary wound healing and survival in critically ischemic skin by the systemic application of left-shifted liposomal hemoglobin vesicles (HbVs). This was tested in bilateral, cranially based dorsal skin flaps in mice treated with a HbV solution with an oxygen affinity that was increased to a P(50) (partial oxygen tension at which the hemoglobin becomes 50% saturated with oxygen) of 9 mmHg. Twenty percent of the total blood volume of the HbV solution was injected immediately and 24 h after surgery. On the first postoperative day, oxygen saturation in the critically ischemic middle flap portions was increased from 23% (untreated control) to 39% in the HbV-treated animals (P < 0.05). Six days postoperatively, flap tissue survival was increased from 33% (control) to 57% (P < 0.01) and primary healing of the ischemic wound margins from 6.6 to 12.7 mm (P < 0.05) after HbV injection. In addition, higher capillary counts and endothelial nitric oxide synthase expression (both P < 0.01) were found in the immunostained flap tissue. We conclude that left-shifted HbVs may ameliorate the survival and primary wound healing in critically ischemic skin, possibly mediated by endothelial nitric oxide synthase-induced neovascularization

Hemoglobin vesicles reduce hypoxia-related inflammation in critically ischemic hamster flap tissue

OBJECTIVES: The aim of this study was to investigate the effect of a highly viscous, left-shifted hemoglobin vesicle solution (HbV) on the hypoxia-related inflammation and the microcirculation in critically ischemic peripheral tissue. DESIGN: Randomized prospective study. SETTING: University laboratory. SUBJECTS: Twenty-four male golden Syrian hamsters. INTERVENTIONS: Island flaps were dissected from the back skin of anesthetized hamsters for assessment with intravital microscopy. The flap included a critically ischemic, hypoxic area that was perfused via a collateralized vasculature. One hour after completion of the preparation, the animals received an injection of 25% of total blood volume of 0.9% NaCl or NaCl suspended with HbVs at a concentration of 5 g/dL (HbV5) or 10 g/dL (HbV10). MEASUREMENTS AND MAIN RESULTS: Plasma viscosity was increased from 1.32 cP to 1.61 cP and 2.14 cP after the administration of HbV5 and HbV10, respectively (both p 200% (p 50% (p < .01) reduction in cells immunohistochemically stained for tumor necrosis factor-alpha and interleukin-6 and in leukocyte counts, whereas no such changes were observed in the anatomically perfused, normoxic tissue. CONCLUSIONS: Our study suggests that in critically ischemic, hypoxic peripheral tissue, hypoxia-related inflammation may be reduced by a top-load infusion of HbV solutions. We attributed this effect to a restoration of tissue oxygenation and an increase in plasma viscosity, both of which may have resulted in attenuation of secondary microcirculatory impairments