OBJECTIVE Previous evidence suggests that episodes of myocardial ischemia of sufficient duration and intensity are required to produce coronary collateral development during repetitive coronary occlusion. This investigation tested the hypothesis that coronary collateral development is also temporal-dependent. METHODS Chronically instrumented dogs (n = 16) were subjected to brief (2 min) left ...

This investigation tested the hypothesis that metabolic syndrome decreases the relative contribution of specific K(+) channels to coronary reactive hyperemia. Ca(2+)-activated (BK(Ca)), voltage-activated (K(V)), and ATP-dependent (K(ATP)) K(+) channels were investigated. Studies were conducted in anesthetized miniature Ossabaw swine fed a normal maintenance diet (11% kcal from fat) or an excess...

We studied the localization of blood flow control in skeletal muscle by shortterm microocclusions (30-60 seconds) of capillaries and arterioles of the pectoralis muscle in anesthetized frogs (Rana pipiens). The muscle was surgically exposed to permit transillumination and measurement of red cell velocity in the microvessels, but innervation and blood supply were kept intact. About one-third of ...

We present a delay induced three dimensional deterministic system, consisting of malignant tumor cells, hunting and resting immune cells. Stability analysis is performed along with numerical simulations. We obtain certain thresholds which are helpful to control the malignant cell growth. Estimation of time delay factor from our study gives suitable preventive strategy. Our analysis is supported...

In this paper, a delayed prototype model is studied. Regarding the delay as a bifurcation parameter, we prove that a sequence of Hopf bifurcations will occur at the positive equilibrium when the delay increases. Using the normal form method and center manifold theory, some explicit formulae are worked out for determining the stability and the direction of the bifurcated periodic solutions. Fina...

In this paper, we present a novel approach to comprehensively verify timing sensitive blocks, specifically Delay Lines and Delay Locked Loops by modelling transient behavior into the RTL. This paper focuses on reduction of simulation time and increase in design turnaround time. Information gathered from a small set of spice simulations is modelled into a Verilog based environment, which gives s...

This paper describes a set of delay-dependent IQC stability conditions for time-delay uncertainty. The IQC’s are linearly parameterized in terms of a pair of rational stability multipliers, each active over one of a pair of complementary frequency intervals. Using the finite-frequency positive real lemma, each of these finite-frequency IQC conditions are shown to be equivalent to a frequency-in...

Keywords: Systems with time delays Distributed delay Exponential stability Perturbations a b s t r a c t We consider preservation of exponential stability for a system of linear equations with a distributed delay under the addition of new terms and a delay perturbation. As particular cases, the system includes models with concentrated delays and systems of integrodifferential equations. Our met...