Electric and metabolic brain activities were controlled for 49 persons by means of electroencephalography (EEG) and near infrared spectroscopy (NIRS) during different physiological and psychological states, e.g. eyes open or closed, hyperpnoea (HV) or apnoea (AP) and during calculation (addition of one- (CAL.S.) or two-digit numbers (CAL C.)) or Raven's test - set A (RAV A) or more difficult set C (RAV C) or TAT. Both diagnostic methods confirm one another. But sometimes there are more expressive changes in one method than in another, e.g. during HV it is a more prominent deoxyhemoglobin (CO2Hb) increase than an alpha frequency band increase in EEG curves. On the other side, very marked alpha frequency decreasing in EEG during eyes open is followed by only a weak oxyhemoglobin (O2Hb) rise. Synchronous activities are clearly visible during psychic test: increasing O2Hb in NIRS and increasing delta frequency band in EEG spectrum. Decreasing alpha with increasing theta activity during relaxation and somnolence is accompanied by decreasing O2Hb and prominent increasing CO2Hb. Inter individually differences are often but not big. We suggest both methods are good tools for attention and psychic states control.
Let a⊕b=max(a,b) and a⊗b=a+b for a,b∈R. Max-algebra is an analogue of linear algebra developed on the pair of operations (⊕,⊗) extended to matrices and vectors. The system of equations A⊗x=b and inequalities C⊗x≤d have each been studied in the literature. We consider a problem consisting of these two systems and present necessary and sufficient conditions for its solvability. We also develop a polynomial algorithm for solving max-linear program whose constraints are max-linear equations and inequalities.
a1_Statins, the inhibitors of 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase, are most frequently used drugs in the prevention of coronary artery disease due to their cholesterol- lowering activity. However, it is not exactly known whether these effects of statins or those independent of cholesterol decrease account for the protection ag ainst myocardial ischemia- reperfusion (I/R) injury. In this study, we investigated the effect of 5-day treatment with simvastatin (10 mg/kg) in Langendorff- perfused hearts of healthy control (C) and diabetic- hypercholesterolemic (D-H; strept ozotocin + high fat-cholesterol diet, 5 days) rats subjected to 30-min global ischemia followed by 40-min reperfusion for the examination of postischemic contractile dysfunction and reperfusion-induced ventricular arrhythmias or to 30-min (left anterior descending) coronary artery occlusion and 2-h reperfusion for the infarct size determination (IS; tetrazolium stai ning). Postischemic recovery of left ventricular developed pressu re (LVDP) in animals with D-H was improved by simvastatin therapy (62.7±18.2 % of preischemic values vs. 30.3±5.7 % in the untreated D-H; P<0.05), similar to the values in the simvastatin-treated C group, which were 2.5-fold higher than those in the untreated C group. No ventricular fibrillation occurred in the simvastatin-treated C and D-H animals during reperf usion. Likewise, simvastatin shortened the duration of ventri cular tachycardia (10.2±8.1 s and 57.8±29.3 s in C and D-H vs. 143.6±28.6 s and 159.3±44.3 s in untreated C and D-H, respectively, both P<0.05). The decreased arrhythmogenesis in the simvastatin-treated groups correlated with the limitation of IS (in % of risk area) by 66 % and 62 % in C and D-H groups, respectively. However, simvastatin treatment decreased plasma cholesterol levels neither in the D-H animals nor in C., a2_The results indicate that other effects of statins (independent of cholesterol lowering) are involved in the improvement of contractile recovery and attenuation of lethal I/R injury in both, healthy and diseased individuals., A. Adameová, A. Harčárová, J. Matejíková, D. Pancza, M. Kuželová, S. Čarnická, P. Švec, M. Barteková, J. Styk, T. Ravingerová., and Obsahuje bibliografii
Inhibitors of 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase (statins) have been proven to reduce effectively cholesterol level and morbidity and mortality in patients with coronary heart disease and/or dyslipoproteinemia. Statins inhibit synthesis of mevalonate, a precursor of both cholesterol and coenzyme Q (CoQ). Inhibited biosynthesis of CoQ may be involved in some undesirable actions of statins. We investigated the effect of simvastatin on tissue CoQ concentrations in the rat model of NO-deficient hypertension induced by chronic L-NAME administration. Male Wistar rats were treated daily for 6 weeks with L-NAME (40 mg/kg) or with simvastatin (10 mg/kg), another group received simultaneously L-NAME and simvastatin in the same doses. Coenzyme Q9 and Q10 concentrations were analyzed by high performance liquid chromatography. L-NAME and simvastatin alone had no effect on CoQ concentrations. However, simultaneous application of L-NAME and simvastatin significantly decreased concentrations of both CoQ homologues in the left ventricle and slightly decreased CoQ9 concentration in the skeletal muscle. No effect was observed on CoQ level in the liver and brain. We conclude that the administration of simvastatin under the condition of NO-deficiency reduced the level of CoQ in the heart and skeletal muscle what may participate in adverse effect of statins under certain clinical conditions., J. Kucharská, A. Gvozdjáková, F. Šimko., and Obsahuje bibliografii
Let (M, g) be a 4-dimensional Einstein Riemannian manifold. At each point p of M, the tangent space admits a so-called Singer-Thorpe basis (ST basis) with respect to the curvature tensor R at p. In this basis, up to standard symmetries and antisymmetries, just 5 components of the curvature tensor R are nonzero. For the space of constant curvature, the group O(4) acts as a transformation group between ST bases at TpM and for the so-called 2-stein curvature tensors, the group Sp(1) ⊂ SO(4) acts as a transformation group between ST bases. In the present work, the complete list of Lie subgroups of SO(4) which act as transformation groups between ST bases for certain classes of Einstein curvature tensors is presented. Special representations of groups SO(2), T2, Sp(1) or U(2) are obtained and the classes of curvature tensors whose transformation group into new ST bases is one of the mentioned groups are determined., Zdeněk Dušek, Hradec Králové., and Obsahuje seznam literatury
Let T be an operator acting on a Banach space X, let σ(T) and σBW (T) be respectively the spectrum and the B-Weyl spectrum of T. We say that T satisfies the generalized Weyl’s theorem if σBW (T) = σ(T) \ E(T), where E(T) is the set of all isolated eigenvalues of T. The first goal of this paper is to show that if T is an operator of topological uniform descent and 0 is an accumulation point of the point spectrum of T, then T does not have the single valued extension property at 0, extending an earlier result of J. K.Finch and a recent result of Aiena and Monsalve. Our second goal is to give necessary and sufficient conditions under which an operator having the single valued extension property satisfies the generalized Weyl’s theorem.
A problem of measuring tilt around a single axis is discussed in detail with regard to the resultant accuracy. Ways of improving the accuracy, based on application of various mathematical equations, are proposed. Presented results of related experimental studies, performed on a tilt sensor made of a standard MEMS accelerometer, have proven that it is possible to obtain accuracy of such measurements of ca. 0.2 degrees arc. Additionally, a problem of measuring tilt of an object, which rotates within a non-vertical plane, is addressed. and Obsahuje seznam literatury
The singular cases of mechanisms have been defined as those positions of a mechanism where it loses its unambiguousness. Those positions are characterized with abrupt changes of kinematic magnitudes, which then manifest as complications during the mechanism control.
Existence results are established for the resonant problem $y^{\prime \prime }+\lambda _m \,a\,y=f(t,y)$ a.e. on $[0,1]$ with $y$ satisfying Dirichlet boundary conditions. The problem is singular since $f$ is a Carathéodory function, $a\in L_{{\mathrm loc}}^1(0,1)$ with $a>0$ a.e. on $[0,1]$ and $\int ^1_0 x(1-x)a(x)\,\mathrm{d}x <\infty $.
We provide sufficient conditions for solvability of a singular Dirichlet boundary value problem with φ-Laplacian (φ(u ' ))' = f(t, u, u ' ), u(0) = A, u(T) = B, where φ is an increasing homeomorphism, φ(R) = R, φ(0) = 0, f satisfies the Carathéodory conditions on each set [a, b] × R 2 with [a, b] ⊂ (0, T) and f is not integrable on [0, T] for some fixed values of its phase variables. We prove the existence of a solution which has continuous first derivative on [0, T].