In this paper, for complete Riemannian manifolds with radial Ricci or sectional curvature bounded from below or above, respectively, with respect to some point, we prove several volume comparison theorems, which can be seen as extensions of already existing results. In fact, under this radial curvature assumption, the model space is the spherically symmetric manifold, which is also called the generalized space form, determined by the bound of the radial curvature, and moreover, volume comparisons are made between annulus or geodesic balls on the original manifold and those on the model space., Jing Mao., and Obsahuje seznam literatury
Voluntary death, particularly when caused by oneself, defies easy understanding. The individual´s life carries immense value in the West and therefore a rather negative attitude toward death predominates. The attitudes towards death found in Confucianism, Buddhism and Shintó are substabtually different - the death of an individual is seen as a natural part of human life. The manner or style of leaving the world is, however, very important since it validates the life that preceded the event. This article focuses of the problem of voluntary death in Japan. It analyzes the Japanese expressions that specify various types of self-killing and deals with traditional religious and social factors that influence atttudes to self-sacrifice and suicide.
Although physical exercise is known to reduce size of infarction,
incidence of ventricular arrhythmias, and to improve heart
function, molecular mechanisms of this protection are not fully
elucidated. We explored the hypothesis that voluntary running,
similar to adaptive interventions, such as ischemic or remote
preconditioning, may activate components of pro-survival (RISK)
pathway and potentially modify cell proliferation. Sprague-Dawley
adult male rats freely exercised for 23 days in cages equipped
with running wheels, while sedentary controls were housed in
standard cages. After 23 days, left ventricular (LV) myocardial
tissue samples were collected for the detection of expression and
activation of RISK proteins (WB). The day before, a marker of
cell proliferation 5-bromo-2'-deoxyuridine (BrdU) was given to all
animals to detect its incorporation into DNA of the LV cells
(ELISA). Running increased phosphorylation (activation) of Akt,
as well as the levels of PKCε and phospho-ERK1/2, whereas BrdU
incorporation into DNA was unchanged. In contrast, exercise
promoted pro-apoptotic signaling - enhanced Bax/Bcl-2 ratio and
activation of GSK-3β kinase. Results suggest that in the rat
myocardium adapted to physical load, natural cardioprotective
processes associated with physiological hypertrophy are
stimulated, while cell proliferation is not modified. Up-regulation
of pro-apoptotic markers indicates potential induction of cell
death mechanisms that might lead to maladaptation in the longterm.