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67632. The Davidson - Quine dispute on meaning and knowledge: a concise guide
- Creator:
- Tomáš Marvan
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- Quine, W. V. (Willard Van Orman), 1908-2000, Davidson, Donald, 1917-2003, věda, filozofie, science, epistemology, 12, and 00
- Language:
- Czech
- Description:
- The paper adresses the debate between Donald Davidson and W. V. O. Quine on the nature of meanings and knowledge. It is argued that Davidson´s misgivings, though interesting, are not devastating for Quine´s version of empiricism, which is not easily translateble into traditional philosophical categories, Tomáš Marvan., and Obsahuje použitou literaturu
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
67633. The decomposition theory of LTI systems
- Creator:
- Svítek, Miroslav
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- linear dynarnical systems, neural networks, system decomposition, system reconstruction, digital filtering, control theory, Sylvester’s theorems, state-space representation, and linear time invariant systems
- Language:
- English
- Description:
- The paper presents new rnethodology liow to decompose the higlh dimensional LTI (linear time invariant) systam with both distinct and repeated eigenvalues of the transition matrix into a set of first-order LTI models, which could be combined to achieve approximation of the original dynamics. As a tool, the Sylvester’s theorems are used to design the filter bank and parameters of the firstorder models (transition values). At the end, the practical examples are shown and the next steps of research of the decomposition theory are indicated.
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
67634. The decrease of serum leptin levels in oestrogen-treated male mice
- Creator:
- Nedvídková, J., Haluzík, M., and Schreiber, V.
- Type:
- article, model:article, and TEXT
- Subject:
- oestrogens, oestradiol-benzoate, leptin, cAMP, body weight, and mice
- Language:
- English
- Description:
- Adipocyte hormone leptin (OB protein) is considered to be an "adiposity signal" regulating body weight homeostasis and energy balance. We have previously reported that oestrogens (oestradiol-benzoate) significantly decrease the body weight in male rats, increase anterior pituitary and serum levels of the intracellular messenger cAMP, which activates cAMP-dependent protein kinase A , their targets include hormone-sensitive lipase and they influence the brain sympathetic system. The present study tested our hypothesis that oestrogens could influence serum leptin levels in male mice. We found that chronic administration of oestradiol-benzoate significantly attenuated serum levels of leptin, in the dependence on the duration of its administration, and simultaneously decreased body weight. We suppose that oestrogens affect leptin levels interacting with the signal transmission system of cAMP, possibly at the genome level. Our observations that the food consumption of mice with simultaneously decreased body weight and levels of serum leptin support the idea that there exists a satiety factor that counters the effect of low leptin.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
67635. The deep red state of photosystem II in Cyanidioschyzon merolae
- Creator:
- Langley, J., Morton, J., Purchase, Rupert, Tian, L., Shen, L., Han, G., Shen, J.-R., and Krausz, E.
- Format:
- print, bez média, and svazek
- Type:
- model:article and TEXT
- Subject:
- optická spektroskopie, fotosyntéza, optical spectroscopy, photosynthesis, optical spectra, 2, and 581
- Language:
- Multiple languages
- Description:
- We identified and characterised the deep red state (DRS), an optically-absorbing charge transfer state of PSII, which lies at lower energy than P680, in the red algae Cyanidioschyzon merolae by means of low temperature absorption and magnetic circular dichroism spectroscopies. The photoactive DRS has been previously studied in PSII of the higher plant Spinacia oleracea, and in the cyanobacterium Thermosynechococcus vulcanus. We found the DRS in PSII of C. merolae has similar spectral properties. Treatment of PSII with dithionite leads to reduction of cytochrome (cyt) b559 and the PsbV-based cyt c550 as well as the disassembly of the oxygen-evolving complex. Whereas the overall visible absorption spectrum of PSII was little affected, the DRS absorption in the reduced sample was no longer seen. This bleaching of the DRS is discussed in terms of a corresponding lack of a DRS feature in D1D2/cyt b559 reaction centre preparations of PSII., J. Langley, J. Morton, R. Purchase, L. Tian, L. Shen, G. Han, J.-R. Shen, E. Krausz., and Obsahuje bibliografické odkazy
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
67636. The degree of protection different ants (Hymenoptera: Formicidae) provide aphids (Hemiptera: Aphididae) against aphidophages
- Creator:
- Novgorodova, Tatiana A. and Gavrilyuk, Anton V.
- Type:
- article, články, model:article, and TEXT
- Subject:
- Zoologie, zoologie, entomologie, Formicidae, Aphididae, ants, aphids, aphidophages, degree of protection, trophobiosis, behaviour, 2, and 59
- Language:
- English
- Description:
- Aphids play an important role in the life of many ant species supplying them with energy-rich carbohydrate food and in exchange receiving some degree of protection from natural enemies. This study focused on the degree of protection different ants provide myrmecophilous aphids (Hemiptera: Aphididae) in multispecies ant communities. Field investigations were carried out in steppe and forest plant associations in Siberia. The potential level of aggressiveness of six ant species (Formica rufa Linnaeus, F. pratensis Retzius, Lasius fuliginosus (Latreille), L. niger (Linnaeus), Camponotus saxatilis Ruzsky and Myrmica rubra Linnaeus) towards imagines and larvae of ladybirds and lacewings and larvae of hoverflies was tested in the laboratory. A comparative analysis of the occurrence of aphidophages in colonies of the aphid Chaitophorus populeti Panzer and of all aphid-symbionts tended by different ants in the study area has shown that the degree of protection of myrmecophilous aphids from natural enemies significantly differs among ants and is positively correlated with ant colony size. On the whole, the degree of protection of myrmecophilous aphids from aphidophages depends both on the potential level of aggressiveness of ants and their foraging strategy when collecting honeydew (degree of specialisation among honeydew collectors). As the dominant ants Formica s. str. were the most aggressive and provided aphids with the highest degree of protection, we suppose that these ants have the most important influence on the survival of the symbionts in multispecies ant communities whereas the other ants, which live in small colonies of about 102–103 workers, appear at least partially to take advantage of the mutualistic relationships of the dominant ants., Tatiana A. Novgorodova, Anton V. Gavrilyuk., and Obsahuje seznam literatury
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
67637. The degrees of understanding and the inferential component of understanding
- Creator:
- Petkov, Stefan
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- ecological theory of predation, explanatory understanding, scientific explanations, and unification
- Language:
- Slovak
- Description:
- Current debates on the nature of explanatory understanding have converged on the idea that at least one of the core components of understanding is inferential. Philosophers have characterized the inferential dimension of understanding as consisting of several related cognitive abilities to grasp a given explanation and the nexus of complementing explanations to which it belongs. Whilst analyses of both the subjective epistemic abilities related to grasping and objective features of the inferential links within explanations have received much attention, both within theories of explanation and in the literature on understanding, the criteria for evaluating the specific structure and organization of explanatory clusters or nexuses have received much less attention. Nevertheless, two notable exceptions stand out—Khalifa’s characterization of an explanatory nexus and theories of explanatory unification. I take Khalifa’s ideas, together with the basic criteria of successful explanatory unification, as my starting point. To both, I make some corrections and additions, in order to arrive at a more robust notion of an explanatory nexus and ultimately show that its structural properties and the inter-explanatory relations it contains are relevant to the resulting understanding. I propose to represent such nexuses as directed graph trees and show that some of their properties can be related to the degree of understanding that such nested explanatory structures can offer. I will further illustrate these ideas by a case study on an eco-logical theory of predation.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
67638. The dehydrating function of the descending colon in relationship to crypt function
- Creator:
- Naftalin, R. J.
- Type:
- article, model:article, and TEXT
- Subject:
- colon, eryths, absorption, water, and faecal dehydration
- Language:
- English
- Description:
- Very high pressure is required to generate hard faeces - 5-10 atmospheres. This is much more than can be supplied by the mechanical force from the muscular wall of the colon. Osmotic pressure (at least 200 mOsm) can generate the necessary suction forces required to consolidate faeces. The colon has a hypertonic absórbate (net above plasma - 500 mOsm) in uiuo. Fluorescence imaging of perifused rat descending colonic mucosa shows high steady state Na+ concentrations (600 mM) in the intercryptal extracellular space and low [Na + ] present in the crypt lumen. This [Na + ] distribution generates an osmotic pressure gradient across the crypt luminal wall resulting in a fluid inflow into the crypt lumen. Direct observation using confocal fluorescence microscopy of FITC dextran (mol. wt. 10 000) shows that there is concentration polarisation of the dextran in the upper 30 % of the crypt lumen. The time course and steady state distribution of concentration polarisation of fluorescent dyes within the crypt lumen permit an estimation of the fluid convection rate along the length of the crypt lumen. This is sufficient to account for the majority of fluid absorption by the colon. Observation of the suction force on agarose gels by rat descending colon in vivo shows that the colon generates up to 4 000 cm H2O suction pressure on the stiff gels, this is accompanied by a hypertonic absórbate from the gels of 800 mOsm. Disruption of the colonic musoca by bile salts reduces the suction pressure to about 40 cm H2O.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
67639. The demand and supply of favours in dynamic relationships
- Creator:
- Forand, Jean Guillaume and Zápal, Jan
- Publisher:
- CERGE-EI
- Format:
- electronic, svazek, and 53 stran ; 21 cm.
- Type:
- model:monograph and TEXT
- Subject:
- Ekonomie, nabídka a poptávka, modelování a simulace, supply and demand, modeling and simulation, 339.13, 519.86/.87, (048.8), 4, and 33
- Language:
- English and Czech
- Description:
- Jean Guillaume Forand, Jan Zápal., Obsahuje bibliografii a bibliografické odkazy, and České a anglické resumé
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
67640. The demarcation problem of laws of nature
- Creator:
- Bielik, Lukáš
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- laws of nature, causality, Transparent Intensional Logic, universals, and demarcation.
- Language:
- Slovak
- Description:
- The paper focuses on the problem of identification of laws of nature and their demarcation from other kinds of regularities. The problem is approached from the viewpoint of several metaphysical, epistemological, logical and methodological criteria. Firstly, several dominant approaches to the problem are introduced. Secondly, the logical and semantic explicatory framework - Transparent Intensional Logic - is presented for the sake of clarification of logical forms of sentences that are supposed to express the laws of nature. Finally, a complementary strategy to the demarcation problem is proposed, including reconsideration of relevant metaphysical, epistemological, logical and methodological requirements and principles behind the former conceptions., Příspěvek je zaměřen na problematiku identifikace přírodních zákonů a jejich vymezení od jiných druhů zákonitostí. K problému je přistupováno z hlediska několika metafyzických, epistemologických, logických a metodologických kritérií. Nejprve je představeno několik dominantních přístupů k problému. Za druhé, logický a sémantický vysvětlující rámec - Transparent Intensional Logic - je prezentován pro objasnění logických forem vět, které mají vyjadřovat přírodní zákony. V neposlední řadě je navržena komplementární strategie k demarkačnímu problému, včetně přehodnocení relevantních metafyzických, epistemologických, logických a metodických požadavků a principů, které jsou v pozadí dřívějších koncepcí., and Lukáš Bielik
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public