It seems that hypervolemia and vasodilatation coincide in compensated cirrhosis, but neither rank... more It seems that hypervolemia and vasodilatation coincide in compensated cirrhosis, but neither rank nor importance of these factors has been fully clarified in adaptive response to postural change. We studied, with gated equilibrium radionuclide angiography and thoracic electrical bioimpedance the hemodynamic status of 19 patients with compensated cirrhosis and 18 healthy subjects in upright and supine positions. In the upright position, the cirrhotic patients were hypotensive and had decreased peripheral vascular resistance despite increased cardiac output. The transition to the supine position was accompanied by a significant fall in the heart rate and an increase in the stroke volume in both controls (92 +/- 22 to 63 +/- 10 beats/min, and 38 +/- 9 to 62 +/- 19 ml/m2, respectively) and cirrhotic patients (101 +/- 20 to 79 +/- 13 beats/min, and 44 +/- 15 to 63 +/- 19 ml/m2, respectively). Besides, the diastolic arterial pressure fell in controls from 89 +/- 9 mmHg to 81 +/- 11 mmHg; p < 0.01, while it remained unchanged in cirrhotic patients (77 +/- 17 vs 82 +/- 13 mmHg). In the supine position, the cirrhotic patients presented tachycardia and left ventricular hyperkinesy (increased velocity of left ventricular filling and emptying). In conclusion, these results show that in compensated cirrhosis the decreased arterial tone and peripheral blood pooling are important factors of adaptive hemodynamic reaction to postural change.
This paper presents a dynamical systems model of escalation and de-escalation and shows how it re... more This paper presents a dynamical systems model of escalation and de-escalation and shows how it relates to and is enriched by a reaction function model of escalation.
Evaluation of existing steel bridges becomes more important due to natural aging, increasing load... more Evaluation of existing steel bridges becomes more important due to natural aging, increasing load spectra, deterioration caused by corrosion, and other problems. In the result, bridge structures exposed to aggressive environmental conditions are subjected to time-variant changes of resistance. Therefore, there is a need for evaluation procedures for an accurate prediction of the load carrying capacity and reliability of bridge structures, in order to make rational decisions about repair, rehabilitation, and expected life-cycle costs. The objective of this paper is to develop time-variant reliability models for steel girder bridges. Traditional methods based on deterministic analysis do not reveal the actual load carrying capacity of the structure. The proposed approach is based on reliability analysis of components and structural systems. The study involves the selection of representative structures, formulation of limit state functions, development of load models, development of resistance models for corroded steel girders, development of the reliability analysis method, reliability analysis of selected bridges, and development of the time-dependant reliability profiles including deterioration due to corrosion. The results of the study can be used for a better prediction of the service life of deteriorating steel girder bridges, and development of optimal reliability-based maintenance strategies.
The effect of two oral doses (10 and 20 mg) of nifedipine versus placebo on the fasted gallbladde... more The effect of two oral doses (10 and 20 mg) of nifedipine versus placebo on the fasted gallbladder volume and on the meal-induced gallbladder emptying was assessed according to a double-blind study protocol in 12 healthy volunteers. Eight subjects underwent three studies (with placebo and with both nifedipine doses), whereas in two subjects the effect of a 10-mg nifedipine dose, vs placebo and in two others the effect of a 20-mg nifedipine dose vs placebo was examined. The studies were performed on separate days, and the gallbladder volume was measured by means of real-time ultrasonography. Neither placebo nor 20 mg nifedipine per os elicited any significant change in the fasted gallbladder vlume. With 10 mg nifedipine per os a significant increase in the interdigestive gallbladder volume was observed: 22.9±2.9 cm3 before and 26.2±3.2 cm3 after the drug receipt (Pper os without, however, reaching the level of statistical significance. Following 20 mg nifedipineper os, a marked delay in the meal-stimulated gallbladder emptying occurred as reflected by a decrease in the gallbladder ejection fraction from 48.1±4.5% (placebo) to 26.4±5.0% (nifedipine) (PP
Secondary elements such as barriers, sidewalks, and diaphragms may increase the load carrying cap... more Secondary elements such as barriers, sidewalks, and diaphragms may increase the load carrying capacity of girder bridges. This in turn affects reliability. The objective of this study is to evaluate the potential benefit of secondary elements on the system reliability of girder bridges, if these elements are designed with the structural system to participate resisting vehicular live loads. Simple span, two lane structures are considered, with composite steel girders supporting a reinforced concrete deck. For structural analysis, a finite element procedure is developed that combines a grillage model of the bridge deck with solid elements for edge-stiffening effects. Random variables considered are composite girder, barrier, and sidewalk flexural strengths (each in turn composed of many random variables), load magnitude (dead load and truck traffic live load), and live load position. System resistance parameters are estimated with a point integration method. System resistance is evaluated in terms of maximum load carried at ultimate capacity. It was found that the interaction of typical secondary element combinations has a varying effect on system reliability, depending on element stiffness, bridge span, and girder spacing.
In this paper we address the destructiveness and constructiveness of conflict in a Dynamical Syst... more In this paper we address the destructiveness and constructiveness of conflict in a Dynamical Systems Theory framework. We propose that destructive and constructive conflict processes constitute two relatively orthogonal dimensions, of which each is associated with specific variables and components, and has its own distinct dynamics.Destructive processes form a coherent system aimed at inflicting psychological, material or physical damage on the opponent, while constructive processes form a coherent system aimed at achieving one's goals while maintaining or enhancing relations with the opponent. We have constructed Destructive and Constructive Conflict Intensity Scales to assess the intensity of conflict processes in 10 conflicts on internet discussions forums and analyzed these discussions using language analysis software (LIWC). Linguistic analyses were also conducted on 5 military versus 5 human rights blogs. Results of the two studies confirm that constructive and destructive conflict processes are indeed two distinct, relatively independent dimensions, with different dynamics and different correlates. Theoretical and practical implications of this model are discussed.
This paper presents a dynamical systems model of escalation and de-escalation and shows how it re... more This paper presents a dynamical systems model of escalation and de-escalation and shows how it relates to and is enriched by a reaction function model of escalation.
It seems that hypervolemia and vasodilatation coincide in compensated cirrhosis, but neither rank... more It seems that hypervolemia and vasodilatation coincide in compensated cirrhosis, but neither rank nor importance of these factors has been fully clarified in adaptive response to postural change. We studied, with gated equilibrium radionuclide angiography and thoracic electrical bioimpedance the hemodynamic status of 19 patients with compensated cirrhosis and 18 healthy subjects in upright and supine positions. In the upright position, the cirrhotic patients were hypotensive and had decreased peripheral vascular resistance despite increased cardiac output. The transition to the supine position was accompanied by a significant fall in the heart rate and an increase in the stroke volume in both controls (92 +/- 22 to 63 +/- 10 beats/min, and 38 +/- 9 to 62 +/- 19 ml/m2, respectively) and cirrhotic patients (101 +/- 20 to 79 +/- 13 beats/min, and 44 +/- 15 to 63 +/- 19 ml/m2, respectively). Besides, the diastolic arterial pressure fell in controls from 89 +/- 9 mmHg to 81 +/- 11 mmHg; p < 0.01, while it remained unchanged in cirrhotic patients (77 +/- 17 vs 82 +/- 13 mmHg). In the supine position, the cirrhotic patients presented tachycardia and left ventricular hyperkinesy (increased velocity of left ventricular filling and emptying). In conclusion, these results show that in compensated cirrhosis the decreased arterial tone and peripheral blood pooling are important factors of adaptive hemodynamic reaction to postural change.
This paper presents a dynamical systems model of escalation and de-escalation and shows how it re... more This paper presents a dynamical systems model of escalation and de-escalation and shows how it relates to and is enriched by a reaction function model of escalation.
Evaluation of existing steel bridges becomes more important due to natural aging, increasing load... more Evaluation of existing steel bridges becomes more important due to natural aging, increasing load spectra, deterioration caused by corrosion, and other problems. In the result, bridge structures exposed to aggressive environmental conditions are subjected to time-variant changes of resistance. Therefore, there is a need for evaluation procedures for an accurate prediction of the load carrying capacity and reliability of bridge structures, in order to make rational decisions about repair, rehabilitation, and expected life-cycle costs. The objective of this paper is to develop time-variant reliability models for steel girder bridges. Traditional methods based on deterministic analysis do not reveal the actual load carrying capacity of the structure. The proposed approach is based on reliability analysis of components and structural systems. The study involves the selection of representative structures, formulation of limit state functions, development of load models, development of resistance models for corroded steel girders, development of the reliability analysis method, reliability analysis of selected bridges, and development of the time-dependant reliability profiles including deterioration due to corrosion. The results of the study can be used for a better prediction of the service life of deteriorating steel girder bridges, and development of optimal reliability-based maintenance strategies.
The effect of two oral doses (10 and 20 mg) of nifedipine versus placebo on the fasted gallbladde... more The effect of two oral doses (10 and 20 mg) of nifedipine versus placebo on the fasted gallbladder volume and on the meal-induced gallbladder emptying was assessed according to a double-blind study protocol in 12 healthy volunteers. Eight subjects underwent three studies (with placebo and with both nifedipine doses), whereas in two subjects the effect of a 10-mg nifedipine dose, vs placebo and in two others the effect of a 20-mg nifedipine dose vs placebo was examined. The studies were performed on separate days, and the gallbladder volume was measured by means of real-time ultrasonography. Neither placebo nor 20 mg nifedipine per os elicited any significant change in the fasted gallbladder vlume. With 10 mg nifedipine per os a significant increase in the interdigestive gallbladder volume was observed: 22.9±2.9 cm3 before and 26.2±3.2 cm3 after the drug receipt (Pper os without, however, reaching the level of statistical significance. Following 20 mg nifedipineper os, a marked delay in the meal-stimulated gallbladder emptying occurred as reflected by a decrease in the gallbladder ejection fraction from 48.1±4.5% (placebo) to 26.4±5.0% (nifedipine) (PP
Secondary elements such as barriers, sidewalks, and diaphragms may increase the load carrying cap... more Secondary elements such as barriers, sidewalks, and diaphragms may increase the load carrying capacity of girder bridges. This in turn affects reliability. The objective of this study is to evaluate the potential benefit of secondary elements on the system reliability of girder bridges, if these elements are designed with the structural system to participate resisting vehicular live loads. Simple span, two lane structures are considered, with composite steel girders supporting a reinforced concrete deck. For structural analysis, a finite element procedure is developed that combines a grillage model of the bridge deck with solid elements for edge-stiffening effects. Random variables considered are composite girder, barrier, and sidewalk flexural strengths (each in turn composed of many random variables), load magnitude (dead load and truck traffic live load), and live load position. System resistance parameters are estimated with a point integration method. System resistance is evaluated in terms of maximum load carried at ultimate capacity. It was found that the interaction of typical secondary element combinations has a varying effect on system reliability, depending on element stiffness, bridge span, and girder spacing.
In this paper we address the destructiveness and constructiveness of conflict in a Dynamical Syst... more In this paper we address the destructiveness and constructiveness of conflict in a Dynamical Systems Theory framework. We propose that destructive and constructive conflict processes constitute two relatively orthogonal dimensions, of which each is associated with specific variables and components, and has its own distinct dynamics.Destructive processes form a coherent system aimed at inflicting psychological, material or physical damage on the opponent, while constructive processes form a coherent system aimed at achieving one's goals while maintaining or enhancing relations with the opponent. We have constructed Destructive and Constructive Conflict Intensity Scales to assess the intensity of conflict processes in 10 conflicts on internet discussions forums and analyzed these discussions using language analysis software (LIWC). Linguistic analyses were also conducted on 5 military versus 5 human rights blogs. Results of the two studies confirm that constructive and destructive conflict processes are indeed two distinct, relatively independent dimensions, with different dynamics and different correlates. Theoretical and practical implications of this model are discussed.
This paper presents a dynamical systems model of escalation and de-escalation and shows how it re... more This paper presents a dynamical systems model of escalation and de-escalation and shows how it relates to and is enriched by a reaction function model of escalation.
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