The function of adult neurogenesis in the dentate gyrus is not yet completely understood, though many competing theories have attempted to explain the function of these newly -generated neurons. Most theories give adult neurogenesis a role in aiding known hippocampal/dentate gyrus functions. Other theories offer a novel role for these new cells based on their unique physiological qualities, such as their low excitability threshold. Many behavioral tests have been used to test these theories, but results have been inconsistent and often contradictory. Substantial variability in tests and protocols may be at least partially responsible for the mixed results. On the other hand, conflicting results arising from the same tests can serve as aids in elucidating the function of adult neurogenesis. Here, we offer a hypothesis that considers the cognitive nature of tasks commonly used to assess the function of adult neurogenesis, and introduce a dichotomy between tasks focused on discrimination vs. generalization. We view these two aspects as opposite ends of the continuous spectrum onto which traditional tests can be mapped. We propose that high neurogenesis favors behavioral discrimination while low adult neurogenesis favors behavioral generalization of a knowledge or rule. Since many tasks require both, the effects of neurogenesis could be cancelled out in many cases. Although speculative, we hope that our view presents an interesting and testable hypothesis of the effect of adult neurogenesis in traditional behavioral tasks. We conclude that new, carefully designed behavioral tests may be necessary to reach a final consensus on the role of adult neurogenesis in behavior., A. Pistikova, H. Brozka, A. Stuchlik., and Obsahuje bibliografii
We evaluated the effects of N G -nitro-L-arginine methylester (L-NAME) (50 mg/kg/day) and 7-nitroindazole (7NI) (10 mg/kg/day) administered from 10th-16th week of age either individually or together on cardiovascular system of Wistar rats and SHR. Systolic blood pressure (sBP) was measured weekly by the plethysmographic method. For morphological studies, the animals (n=10) were perfused with a fixative (120 mm Hg), and thoracic aorta and carotid and co ronary arteries were processed for electron microscopy. For functional investigation (n=10), aortic rings were used in an or gan bath. In Wistar rats, L-NAME evoked an increase of sBP; hype rtrophy of the heart and arterial walls; an increase in cross-sectional areas (CSA) of endothelial cells (EC), muscle cells (SMC), extracellular matrix (ECM), and a decrease in acetylcholin e-induced endothelial-dependent relaxation (EDR). 7NI evoked sBP-independent hypotrophy of the heart and arterial walls, a decrease in CSA of EC and SMC without affecting the CSA of ECM, and a mild decrease in acetylcholine-induced EDR. 7NI and L-NAME administered together evoked lower effect on BP and trophicity of the heart and all arteries, and a similar de crease in acetylcholine-induced EDR compared to L-NAME alone. In SHR, 7NI did not evoke any effect on the studied parameters., F. Kristek, M. Drobna, S. Cacanyiova., and Obsahuje bibliografii
This paper focuses on the roots of a functional theory of predication, which is represented primarly by Frege and Russell. After a brief presentation of the theory of Frege, I concentrate on the philosophical motivation of this theory. The example of the influence of F. H. Bradley on Russell’s conception of the categorical judgements shows a common epistemological position of both authors, which I recognize also in Frege. The point of the article is to find common grounds in Kant noetics, especially in his conception of synthetic judgement. Replacement of the problematic Kant’s notion of transcendental schema by the functional application subsequently allowed flourishing of the theory. In conclusion, I outline potential problems associated with the challenge of philosophical assumptions on which this theory is based., Příspěvek se zaměřuje na kořeny funkční teorie predikce, kterou reprezentují především Frege a Russell. Po krátké prezentaci teorie Frege se zaměřuji na filosofickou motivaci této teorie. Příklad vlivu FH Bradleyho na Russellovu koncepci kategorických úsudků ukazuje společné epistemologické postavení obou autorů, které uznávám i ve Frege. Cílem článku je najít společné důvody v Kantově noetice, zejména v jeho koncepci syntetického úsudku. Nahrazení problematického Kantova pojmu transcendentálního schématu funkční aplikacínásledně umožnil rozkvět teorie. V závěru nastiňuji možné problémy spojené s výzvou filozofických předpokladů, na nichž je tato teorie založena., and Karel Šebela
In the paper we discuss the uniqueness problem for meromorphic functions that share two sets and prove five theorems which improve and supplement some results earlier given by Yi and Yang [13], Lahiri and Banerjee [5].
Logical analysis of natural language (LANL) based on TIL defines meaning (Frege’s sense) in a procedural way, resulting in the following thesis: The meaning of an expression is independent of context. The meaning (in the case of non-indexical expressions concept) is thus an abstract procedure, which is explicated in TIL as (well-defined) construction. What does depend on context is the way in which the meaning has to be handled. From this viewpoint we can distinguish three kinds of context: (i) hyperintensional context; (ii) intensional context; (iii) extensional context., Logická analýza přirozeného jazyka (LANL) na základě TIL definuje význam (Fregeho smysl ) v procesním způsobem, což má za následek následující práce: Význam výrazu je nezávislá na kontextu . Význam (v případě konceptu neindexových výrazů ) je tedy abstraktním postupem, který je vysvětlen v TIL jako (dobře definovaná) konstrukce . To, co závisí na kontextu, je způsob, jakým je třeba tento význam řešit . Z tohoto pohledu můžeme rozlišit tři druhy kontextů: (i) hyperintenzionální kontext; ii) intenzivní souvislosti; iii) kontext prodloužení., and Pavel Materna