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41532. What is the optimal light source for optical mapping using voltage- and calcium-sensitive dyes?
- Creator:
- Olejníčková, Veronika and Sedmera, David
- Format:
- počítač and online zdroj
- Type:
- model:article and TEXT
- Subject:
- světelné diody, light emitting diodes, xenon lamp, chick, mouse, optical mapping, mercury lamp, di-4-ANEPPS, 14, and 612
- Language:
- English
- Description:
- Optical mapping is a fluorescence-based physiological method to image spreading of action potential in excitable tissues, such as the heart and central nervous system. Because of the requirements for high speed imaging in low light conditions, highly sensitive high-speed cameras together with an optical system with maximum photon efficiency are required. While the optimization of these two components is relatively straightforward, the choice of the perfect light source is less simple; depending on the other (usually fixed) components, various parameters may acquire different weight in decisionmaking process. Here we describe the rationale for building an optical mapping setup and consider the relative advantages and disadvantages of three different commonly available light sources: mercury vapor lamp (HBO), xenon lamp (XBO), and light emitting diode (LED). Using the same optical system (fluorescence macroscope) and high-speed camera (Ultima L), we have tested each of the sources for its ability to provide bright and even illumination of the field of view and measured its temporal fluctuations in intensity. Then we used each in the actual optical mapping experiment using isolated, perfused adult mouse heart or chick embryonic heart to determine the actual signal to noise ratio at various acquisition rates. While the LED sources have undergone significant improvements in the recent past, the other alternatives may still surpass them in some parameters, so LEDs may not be the automatic number one choice for every application., Veronika Olejnickova, David Sedmera., and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
41533. What is the role of subcutaneous single injections on the behavior of adult male rats exposed to drugs?
- Creator:
- Šlamberová, R., Nohejlová, K., Ochozková, A., and Mihalčíková, L.
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- amphetamine, MDMA, cocaine, THC, behavior, LABORAS test • Injection, and injection
- Language:
- English
- Description:
- Psychostimulants, as well as cannabinoids, have been shown to significantly affect a great variety of behaviors in both humans and laboratory animals. Our previous studies have repeatedly demonstrated that the application of the vehicle for psychostimulants, i.e. saline, to control groups, generated different behavioral test results compared to absolute naïve controls (i.e. without any injection). Therefore, our present study has set three goals: (1) to evaluate the effect of three different psychostimulant drugs, (2) to evaluate the effect of three doses of delta 9-tetrahydrocannabinol (THC), and (3) to evaluate the effect of saline and ethanol injections vs sham injections and no injection on spontaneous behavior of adult male rats. The LABORAS test (Metris B.V., Netherlands) was used to examine spontaneous locomotor activity and exploratory behavior in an unknown environment over 1 h. In Experiment 1, psychostimulant drugs were tested: single subcutaneous (s.c.) injections of amphetamine (5 mg/kg), cocaine (5 mg/kg), and 3,4-methylenedioxymethamphetamine (MDMA) (5 mg/kg) were applied prior to testing. Control animals received the same volume (1 ml/kg) of s.c. saline. In Experiment 2, the effect of three doses of THC (1, 2, and 5 mg/kg, s.c.) were examined. An s.c. injection of vehicle (ethanol) was used as a control. In Experiment 3, injections of saline and ethanol were compared to the group receiving a sham s.c. injection and to a group of absolute “naïve” controls. Our results demonstrated that (1) all psychostimulants increased locomotion time, distance traveled, and speed while decreasing immobility time of adult male rats relative to saline controls. The most prominent effect was associated with MDMA; (2) The effect of THC was dosedependent and was most apparent within the first 10 min of the LABORAS test. (3) With regard to the effect of injection: absolute controls (without injection) compared to animals injected with ethanol, saline, or sham-injected displayed reduced immobility time, traveled longer distances, and had increased speed. In conclusion, our data showed drug dependent behavioral changes in adult male rats after application of psychostimulants and cannabinoids. Our findings also suggest that not only drugs but the actual single injection per se also affects the behavior of laboratory animals in an unknown environment. This effect seems to be associated with the acute stress associated with the injection.
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
41534. What sort of statement is ''/p/ is a phoneme of English''?
- Creator:
- Rastall , Paul
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- ontological commitment, linguistic description, judgments, constructs, particulars, identification, characterization, and hypotheses
- Language:
- Slovak
- Description:
- The article considers the nature of descriptive statements and the ontological status of descriptive constructs in linguistics, taking the example of a phoneme of English. It is argued that descriptive statements should be seen as expressions of the content of descriptive models or as hypotheses. Furthermore, it is argued that descriptive models and constructs in linguistics have a purely explanatory function in relation to speech events and without ontological commitment to corresponding entities in the real world., Článek pojednává o povaze popisných výroků a ontologickém stavu deskriptivních konstrukcí v lingvistice, přičemž vychází z příkladu fonému angličtiny. Argumentuje se tím, že popisná prohlášení by měla být chápána jako vyjádření obsahu popisných modelů nebo jako hypotézy. Dále, to je argumentoval, že popisné modely a konstrukce v lingvistice mají čistě vysvětlující funkci ve vztahu k událostem řeči a bez ontologického závazku k odpovídajícím entitám v reálném světě., and Paul Rastall
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
41535. What we know about numbers and propositions and how we know it
- Creator:
- Soames, Scott
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- arithmetic, cognition, knowledge, natural numbers, plural properties, plural quantification, propositional attitudes, propositions, representation, and semantics
- Language:
- Slovak
- Description:
- The paper sketches and defends two instances of the strategy Let N’s be whatever they have to be to explain our knowledge of them—one in which N’s are natural numbers and one in which N’s are propositions. The former, which makes heavy use of Hume’s principle and plural quantification, grounds our initial knowledge of number in (a) our identification of objects as falling under various types, (b) our ability to count (i.e. to pair memorized numerals with individuated objects of one’s attention), (c) our (initially perceptual) recognition of plural properties (e.g. being three in number), and (d) our predication of those properties of pluralities that possess them (even though no individuals in the pluralities do). Given this foundation, one can use Fregean techniques to non-paradoxically generate more extensive arithmetical knowledge. The second instance of my metaphysics-in-the-service-of-epistemology identifies propositions (i.e. semantic contents of some sentences, objects of the attitudes, and bearers of truth, falsity, necessity, contingency, and apriority) with certain kinds of purely representational cognitive acts, operations, or states. In addition to providing natural solutions to traditionally un-addressed epistemic problems involving linguistic cognition and language use, I argue that this metaphysical conception of propositions expands the solution spaces of many of the most recalcitrant and long-standing problems in natural-language semantics and the philosophy of language.
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
41536. What’s the price of a nonmeasurable set?
- Creator:
- Sardella, Mirko and Ziliotti, Guido
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- Lebesgue measure, nonmeasurable set, and axiom of choice
- Language:
- English
- Description:
- In this note, we prove that the countable compactness of {0, 1} R together with the Countable Axiom of Choice yields the existence of a nonmeasurable subset of . This is done by providing a family of nonmeasurable subsets of whose intersection with every non-negligible Lebesgue measurable set is still not Lebesgue measurable. We develop this note in three sections: the first presents the main result, the second recalls known results concerning non-Lebesgue measurability and its relations with the Axiom of Choice, the third is devoted to the proofs.
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
41537. Wheatcroft, Andrew: Nevěřící
- Creator:
- Ostřanský, Bronislav
- Type:
- article, model:article, and TEXT
- Language:
- Czech
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
41538. Wheater C.P. and Cook P.A.: Studying Invertebrates
- Creator:
- Nedvěd, O.
- Type:
- article, model:article, and TEXT
- Language:
- English
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
41539. Wheeler A.G. Jr: Biology of the Plant Bugs (Hemiptera: Miridae)
- Creator:
- Štys, P.
- Type:
- article, model:article, and TEXT
- Language:
- English
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
41540. When benevolence harms women and favours men: the effects of ambivalent sexism on leadership aspiration
- Creator:
- Rollero, Chiara and Fedi, Angela
- Format:
- print, bez média, and svazek
- Type:
- article, předběžná sdělení, model:article, and TEXT
- Subject:
- Psychologie, psychologie, gender, aspirace na vůdcovství, ambivalentní sexismus, leadershoip aspiration, ambivalent sexism, 17, and 159.9
- Language:
- Czech
- Description:
- Když benevolence zraňuje ženy a favorizuje muže: účinky ambivalentního sexismu na aspirace na vůdcovství Literatura o ambivalentním sexismu ukázala, že benevolence vůči ženám může být dokonce škodlivější než otevřené nepřátelství, protože není jasně rozpoznatelná jako druh předsudku, a tak je obtížnější s ní bojovat. Podobně benevolence vůči mužům predikuje vnímanou oprávněnost genderové hierarchie. Účinek sexismu na mužské a ženské aspirace na vůdcovství však ještě nebyl zkoumán. Účastníci studie (N = 101) byli poučeni o sexismu (hostilním vs. benevolentním) vůči vlastnímu pohlaví. Výsledky ukázaly, že benevolence podporuje možnost udržení vůdcovské role u mužů, ale odrazuje ženy od vůdcovských pozic. Ženy dokonce považují benevolentní a hostilní postoje vůči ženám za podobné předsudky. Muži naopak vymezují hostilní sexismus vůči mužům jako více předsudečný než benevolentní postoje., Literature on ambivalent sexism has shown that benevolence toward women can be even more pernicious than explicit hostility because it is not clearly recognizable as a form of prejudice and thus it is more difficult to combat. Similarly, benevolence toward men predicts the perceived legitimacy of gender hierarchy. However, the effects of sexism on men’s and women’s leadership aspiration have not been studied yet. In the present study participants (N = 101) were primed with sexism (Hostile vs. Benevolent) toward their own gender. Results showed that benevolence fosters the possibility of holding a leadership role for men, but harms women from leader positions. Moreover, women consider benevolent and hostile attitudes toward women as similarly prejudiced. On the contrary, men define hostile sexism toward men as more prejudiced than benevolent attitudes., Chiara Rollero, Angela Fed., and Obsahuje seznam literatury
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public