In this paper I wish to discuss so-called principles of inheritance and the familiar claim that it leads to deontic paradoxes. By combining two such paradoxes it will be shown that inheritance amounts to a principle of explosion: supposing that in the actual world there is at least one thing that one ought to do, almost anything is something one ought to do. I will then attempt to qualify the principle of inheritance so as to avoid this and other paradoxical results., V této práci chci diskutovat o tzv. Principech dědictví a známém tvrzení, že vede k deontickým paradoxům. Spojením dvou takových paradoxů se ukáže, že dědictví se rovná principu exploze: za předpokladu, že ve skutečném světě existuje alespoň jedna věc, kterou by člověk měl udělat, téměř cokoliv by mělo být. Pak se pokusím o to, aby se princip dědičnosti kvalifikoval tak, aby se tomuto a dalším paradoxním výsledkům vyhnul., and David Botting
This paper considers an exponential cost optimality problem for finite horizon semi-Markov decision processes (SMDPs). The objective is to calculate an optimal policy with minimal exponential costs over the full set of policies in a finite horizon. First, under the standard regular and compact-continuity conditions, we establish the optimality equation, prove that the value function is the unique solution of the optimality equation and the existence of an optimal policy by using the minimum nonnegative solution approach. Second, we establish a new value iteration algorithm to calculate both the value function and the ϵ-optimal policy. Finally, we give a computable machine maintenance system to illustrate the convergence of the algorithm.
Previous studies have suggested that the Notch signaling pathway plays a very important role in the proliferation and differentiation of pulmonary microvascular endothelial cells (PMVECs). Therefore, we aimed to investigate the expression level of Notch-related signaling molecules in PMVECs in bleomycin (BLM)-induced rat pulmonary fibrosis. Immunohistochemistry, immunofluorescence, Western blotting, and real-time PCR were used to analyze the differences in protein and mRNA expression levels of Notch-related signaling molecules, i.e. Notch1, Jagged1, Delta-like ligand 4 (Dll4), and hairy and enhancer of split homolog 1 (Hes1), between a control group treated with intratracheal instillation of saline and a study group treated with intratracheal instillation of BLM solution. Expression levels of the receptor Notch1 and one of its ligands, Jagged1, were upregulated, while the expression levels of the ligand Dll4 and the target molecule of the Notch signaling pathway, Hes1, were downregulated. The differences in protein and mRNA expression levels between the control and study groups were significant (p<0.001). The Jagged1/Notch1 signaling pathway is activated in the pathogenesis of BLM-induced rat pulmonary fibrosis, while the Dll4/Notch1 signaling pathway is inhibited, which inhibits the suppressive effect of Dll4/Notch1 signaling on PMVEC overproliferation, further causing PMVEC dysfunction in cell sprouting and maturation as well as abnormal differentiation of the cell phenotype. Conversely, the downexpression of Hes1 indicates that the Jagged1/Notch1 signaling pathway could be a non-canonical Notch signaling pathway independent of Hes1 activation, which differs from the canonical Dll4/Notch1 signaling pathway., Q. Yin, W. Wang, G. Cui, H. Nan, L. Yan, W. Zhang, S. Zhang, J. Wei., and Obsahuje bibliografii
In the present study we investigated the effect of a two-stage bilateral lesion of the olfactory bulb (OB) in rats on the regeneration ability of peripheral olfactory neurons and their reinnervation capacity in the spared OB. The outgrowth of newly-generated olfactory axons as well as the maturation of their terminal synaptic field was detected by immunohistochemistry of the growth-associated phosphoprotein B-50/GAP-43. In addition, the glial response to the surgery was monitored by an immunohistochemical marker for astrocytes, glial fibrillary acidic protein (GFAP). In neonatal rats (P3-P5), the right OB was removed, then three months later the contralateral side was ablated. Six days after the second operation the animals were transcardially perfused. Their brains were embedded in paraplast, serially sectioned and processed for histological and immunohistochemical observations. After neonatal OB ablation, homogeneous B-50-immunoreactivity (BIR) was found in the forebrain, olfactory axons and ectopic glomeruli localized in the small OB remnant-like structures and in the regenerated neuroepithelium. A strong GFAP response was revealed in the brain cortex as well as in the newly-formed olfactory axons and glomeruli-like structures of the OB remnants. After adult OB ablation strong BIR was observed in olfactory axons, while remaining glomerular structures were only faintly stained. The neuroepithelium revealed signs of massive degenerative processes with a substantial decrease in BIR. The GFAP-positive astrocytes were scattered throughout the entire OB remnant and were prominent in the glomeruli-like structures and adjacent frontal cortex. In the present study, we applied GAP-43 and GFAP immunohistochemistry to characterize the responses of individual olfactory components after two-stage olfactory bulbectomy. Furthermore, this model of OB ablation characterized by two immunohistochemical markers could elucidate certain molecular mechanisms involved in the regeneration and/or plasticity of the olfactory system.
The host immune response to parasitic infections plays an important role in controlling multiplication of the parasite and reducing clinical symptoms and life-threatening complications. Nitric oxide (NO), an important innate immune factor and classic Th1 immune effector, may play a role in inhibiting plasmodium infection. In this study, we used two different approaches (L-Arginine [precursor of NO] and NOC5 [short-time NO donor]) to prove the roles of NO in malaria infection. We used 6-8 week-old female BALB/c mice infected with the rodent malaria Plasmodium yoelii Landau, Michel et Adam, 1968 - strain 17XL (P.y17XL) - as a model. For L-Arg treatment, mice were administered with an oral dose of 1.5 mg/g L-Arg daily for seven consecutive days prior to infection with P.y17XL. L-Arg pretreatment resulted in the decrease of the mRNA level of the apical membrane antigen 1 (AMA1) gene, which encodes a protein involved in host invasion. For NOC5 treatment, NOC5 was injected intraperitoneally into the P.y17XL infected mice on day 5 post-infection or incubated in vitro with purified P.y17XL schizonts. Both in vivo and in vitro treatments with NOC5 led to down-regulation of the transcript and protein levels of invasion-related molecules (AMA1, merozoites surface protein 1 and Py235). Our results confirmed the protective role of NO in the asexual blood stage of parasitic infection, which may be partially due to reduced expression of parasite invasion molecules.
Mrk 3 is an early-type galaxy, probably a transition case between E and SO. Analysis of the isophotes clearly shows a disk component along the major axis. A large extended emission line region (EELR) was found. It is confined to a disk along the minor axis, perpendicular to the stellar disk component. The radio-jet of Mrk 3 is almost perpendicular to the stellar disk and has a small inclination only against the EELR.
The ionization mechanism and dynamical state of the EELR was studied from several longslit spectrograms both along and perpendicular to the EELR extension. Both, [OIII]/Hβ and [NII]/Hα clearly indicate that the spectrum of the NLR deviates from HII regions. The line ratios are similar to the values found for the NLR of Mrk 3, indicating that the powerlaw source is responsible for the ionization out to several Kpc.
Off-centre spectrograms indicate that the kinematics is governed by rotation and an additional inflow motion. This accretion flow could have velocities as large as 20 km/sec. It is speculated that the unusually broad and asymmetric lines of the NLR indicate a close interaction with the velocity pattern of the EELR.
The extracellular matrix (ECM) consists of proteins,
glycosaminoglycans and glycoproteins, that support the dynamic
interactions between cells, including intercellular communication,
cell attachment, cell differentiation, cell growth and migration. As
such, the ECM represents an essential and very sensitive system
within the tissue microenvironment that is involved in processes
such as tissue regeneration and carcinogenesis. The aim of the
present review is to evaluate its diversity through Ca2+ signaling
and its role in muscle cell function. Here, we discuss some
methodological approaches dissecting Ca2+ handling mechanisms
in myogenic and non-myogenic cells, e.g. the importance of Ca2+
and calpains in muscle dystrophy. We also consider the
reconstruction of skeletal muscle by colonization of decellularized
ECM with muscle-derived cells isolated from skeletal muscle.
Therefore, it is necessary to establish new methodological
procedures based on Ca2+ signaling in skeletal muscle cells and
their effect on ECM homeostasis, allowing the monitoring of
skeletal muscle reconstruction and organ repair.
Ectoedemia argyropeza (Zeller, 1839) possesses a compound eye that exhibits features of both apposition and superposition type eyes. Like apposition eyes, the eye of E. argyropeza lacks a clear-zone, which in superposition eyes separates the distal dioptric from the proximal light-perceiving structures. On the other hand, a tracheal layer around the proximal ends of the rhabdom as well as a well-developed corneal nipple array on the corneal surfaces are features that E. argyropeza shares with the larger moths. Unique, and so far only seen to this extreme degree in any insect, is the hourglass-shape of E. argyropeza's rhabdom, in which two almost equally voluminous regions (one distal, one proximal and formed in both cases by seven rhabdomeres) are connected by a narrow waist-like region of the retinula. An eighth retinula cell, not participating in rhabdom formation, is developed as a basal cell, just above the basement membrane. The eye responds with photomechanical changes to dark/light adaptation, but while the proximal rhabdom moiety slightly expands (as expected) in the dark, the distal rhabdom increases its diameter only upon light-adaptation. Owing to the tandem position of the two rhabdom moities, it is in the light-adapted state that the distally-placed rhabdom is favoured, while the proximal rhabdom plays a more important role at low ambient light levels. With screening pigments withdrawn, tracheal tapetum exposed, and distal rhabdom diameters reduced, the proximal and in the dark enlarged rhabdom is then in a position to capture photons that have entered the eye through not only the ommatidial window above, but other facets as well even in the absence of a clear-zone and superposition optics.
We present a method for the construction of artificial far-field boundary conditions for two- and three-dimensional exterior compressible viscous flows in aerodynamics. Since at some distance to the surrounded body (e.g. aeroplane, wing section, etc.) the convective forces are strongly dominant over the viscous ones, the viscosity effects are neglected there and the flow is assumed to be inviscid. Accordingly, we consider two different model zones leading to a decomposition of the original flow field into a bounded computational domain (near field) and a complementary outer region (far field). The governing equations as e.g. compressible Navier-Stokes equations are used in the near field, whereas the inviscid far field is modelled by Euler equations linearized about the free-stream flow. By treating the linear model analytically and numerically, we get artificial far-field boundary conditions for the (nonlinear) interior problem. In the two-dimensional case, the linearized Euler model can be handled by using complex analysis. Here, we present a heterogeneous coupling of the above-mentioned models and show some results for the flow around the NACA0012 airfoil. Potential theory is used for the three-dimensional case, leading also to non-local artificial far-field boundary conditions.