Propranolol, atenolol, and trifluoperazine reduce the spontaneous occurrence of meiotic diploid products in Saccharomyces cerevisiae

1982 ◽  
Vol 2 (11) ◽  
pp. 1299-1303
Author(s):  
S Sora ◽  
M Bianchi

The effect of atenolol, propranolol, trifluoperazine, and caffeine on the occurrence of meiotic diploid and disomic products in Saccharomyces cerevisiae was investigated. We demonstrated that atenolol, propranolol, and trifluoperazine reduce the occurrence of meiotic diploid products and that propranolol also slightly decreases the spontaneous frequency of disomics. On the other hand, caffeine appears to be a powerful inducer of diploid meiotic products, but also shows a lesser effect on disomic induction. Since spontaneous or caffeine-induced diploids arise from a failure of the second meiotic division, it appears that the target of these drugs is at the beginning of the second meiotic division. The only common effect of trifluoperazine and propranolol, mainly investigated in mammals, was an inhibition of calmodulin activity via direct interaction. We tend, therefore, to believe that calmodulin activity must be a crucial point for the second meiotic division to begin. The increased induction of diploids, due to caffeine, may be interpreted as a consequence of an increased cyclic AMP level.

1982 ◽  
Vol 2 (11) ◽  
pp. 1299-1303 ◽  
Author(s):  
S Sora ◽  
M Bianchi

The effect of atenolol, propranolol, trifluoperazine, and caffeine on the occurrence of meiotic diploid and disomic products in Saccharomyces cerevisiae was investigated. We demonstrated that atenolol, propranolol, and trifluoperazine reduce the occurrence of meiotic diploid products and that propranolol also slightly decreases the spontaneous frequency of disomics. On the other hand, caffeine appears to be a powerful inducer of diploid meiotic products, but also shows a lesser effect on disomic induction. Since spontaneous or caffeine-induced diploids arise from a failure of the second meiotic division, it appears that the target of these drugs is at the beginning of the second meiotic division. The only common effect of trifluoperazine and propranolol, mainly investigated in mammals, was an inhibition of calmodulin activity via direct interaction. We tend, therefore, to believe that calmodulin activity must be a crucial point for the second meiotic division to begin. The increased induction of diploids, due to caffeine, may be interpreted as a consequence of an increased cyclic AMP level.


Author(s):  
Carolina Lacerda Medeiros

<p><strong>Resumo:</strong> A literatura que discute a sintaxe do verbo nas línguas naturais em geral assume que as línguas V2 são aquelas em que o verbo flexionado ocupa a segunda posição na sentença, sendo a primeira posição ocupada por qualquer outro elemento. O alemão, assim como outras línguas germânicas, é caracterizado como uma língua de tipo V2. O inglês, por outro lado, não apresenta a ordenação de constituintes segundo a qual o verbo obrigatoriamente ocupa a segunda posição na sentença, tendo sido considerado uma língua V2 apenas em seu período arcaico. Este artigo procura fazer um breve estudo comparativo analisando a fala de duas crianças, uma adquirindo o alemão e uma adquirindo o inglês britânico, em diferentes momentos (1;9 até 3;3). Com base na tipologia de Vikner (1995) temos como objetivo verificar até que ponto as duas línguas se assemelham, no âmbito da sintaxe, e em que momento passam a se comportar como línguas distintas no que respeita à posição do verbo uma vez que, linearmente, o inglês apresenta o verbo em segunda posição nas sentenças simples. Como hipótese, temos que um ponto decisivo para a diferenciação das duas gramáticas seria a aquisição de encaixadas. Desse modo, a criança que adquire o alemão começaria a apresentar traços de uma gramática V2 a partir do momento em que adquire sentenças encaixadas, dado que, diferentemente do inglês, esta língua não apresenta verbo em segunda posição nas subordinadas. A criança adquirindo o inglês, por outro lado, mantém a ordem V2 linear nas encaixadas.  O <em>corpus </em>utilizado neste trabalho é oriundo da base CHILDES e pode ser acessado <em>online</em>. O quadro teórico se baseia na noção de Gramática de Chomsky (1985), convencionada como Língua-I, que remete à possibilidade de se gerarem estruturas linguísticas e não, por exemplo, a um certo inventário de estruturas. Tais possibilidades são limitadas pela Gramática Universal, parte das faculdades inatas do ser humano, que dispõe de princípios imutáveis e parâmetros que podem ser fixados diferentemente em gramáticas particulares, determinando, assim, os limites de variação entre essas gramáticas (Chomsky &amp; Lasnik 1993). Cada gramática particular, neste sentido, representa uma determinada parametrização dos princípios da Gramática Universal. A gramática do falante, na teoria gerativa, será, portanto, uma entidade individual: uma gramática particular internalizada na mente de cada indivíduo.</p><p><strong>Abstract:</strong> <em>The literature usually assumes that V2 languages are those in which the finite verb is on second position on the sentence, like it is in German. English, on the other hand, does not present the same linearization, so Vikner (1995) classified it as a residual V2-language. This paper aims to provide a comparative study analyzing the speech of two children, one acquiring German and the other acquiring European English, in different moments (1;9-3;3). Based on Vikner's typology, we try to verify how these two languages are syntactically alike and in which moment they begin to behave like different grammars, in what concern verb position, since, linearly, English also presents the verb in second position in matrix sentences. As a hypothesis, we believe that a crucial point in this differentiation would be the acquisition of subordinate sentences. In this sense, the child acquiring German would start presenting  V2 grammar traces on the moment s/he acquires subordinate sentences, since, unlike English, this grammar do not present V2 in subordinate structures. The child acquiring English, on the other hand, would maintain the V2 linearization on subordinate sentences. This work is based on the CHILDES corpus, which can be accessed online. The theoretic framework is based on Chomsky's (1985) notion of Grammar as I-Language, that refers to the possibility to generate language structures and not, for example, a certain inventory of structures. Those possibilities are limited by the Universal Grammar, part of human's innate faculties, that is formed by immutable principles and parameters that can be differently fixed by different particular grammars determining the limits of language variation between those grammars. In this sense, each particular grammar represents a different parametrization of the Universal Grammar's principles. Each speaker's grammar, in this sense, will be an individual entity: a particular grammar internalized in the individual's mind</em><em>.</em></p><p>Keywords: <em>Language Acquisition; V2; Comparative Syntax; Generative Grammar.</em></p><p> </p>


1989 ◽  
Vol 9 (2) ◽  
pp. 207-212
Author(s):  
M. D. Fernández-Moreno ◽  
E. Arilla ◽  
J. C. Prieto

The effects of experimental uremia on the concentration of vasoactive intestinal peptide (VIP) in duodenum as well as on the interaction of this neuropeptide with the corresponding epithelial cells were studied in rats. Duodenal VIP concentration was significantly decreased in uremic rats as compared to control animals. The specific binding of VIP to duodenal epithelial cells increased in rats with uremia due to an increase in the number of VIP receptors rather than a change in the binding affinity or in the extent of VIP degradation. On the other hand, the efficacy but not the potency of VIP upon cyclic AMP generation varied in parallel to that observed at the receptor level.


2021 ◽  
Vol 68 ◽  
pp. 69-84
Author(s):  
Lieven D’hulst

The metaphors of centre and periphery tend to reduce the complexity of language relations and interlingual exchanges that are featured by multilingual societies. At a crucial point of multilingual Belgium’s evolution, i.e. during the 19th century, exchanges between its two major languages, namely French and Flemish, offer a suitable angle to capture the processes of centralisation and peripherisation of both languages. Translingual practices, including translation, are at the heart of these processes. On the one hand, they sustain continuous attempts to impose and maintain the centrality of official French in the legal and administrative domains; on the other hand, they nurture counterbalancing claims for recognition and officialisation of Flemish as an equal language. This contribution puts focus on three major aspects of interlingual exchange: the design and management of Belgian translation policies, the asymmetric translation flows between French and Flemish vs. Flemish and French, and the emancipatory efforts of Flemish and its modest effects, notably in the literary domain.


2014 ◽  
Vol 50 (1-2) ◽  
pp. 217-222 ◽  
Author(s):  
J. P. Tilquin

In 1964, two new types of apogamy were described in ferns. The sporangia contain at the starting-point 16 spore mother cells and at the endingpoint 32 diplospores. On the one hand, the meiosis is replaced by a mitosis, on the other hand, the first meiotic division aborts and the restituition nucleus divides mitotically. The author's observations imply that the second process is a variant of the first one.


1983 ◽  
Vol 49 (01) ◽  
pp. 008-012 ◽  
Author(s):  
Shuichi G Hashimoto

SummaryAccumulation of the newly formed 14C-cyclic adenosine 3',5’-monophosphate (cyclic AMP) was found in the P1 (1.0) fraction, i. e. a platelet plasma membrane fraction which was obtained from 14C-adenine-labeled platelets. On the other hand, total cyclic AMP as determined simultaneously was located mainly in the platelet soluble fraction. Furthermore, the highest value of the cyclic AMP-binding capacity was found in the P1 (1.0) fraction. The cyclic AMP-binding activity of platelet membranes was attributed to two proteins with molecular weights of approximately 48,000 and 68,000.The treatment of 14C-adenine-prelabeled platelets with thrombin (1 unit per ml) led to about 40% decrease in the newly formed 14C-cyclic AMP level and 18% reduction of 14C-adenosine triphosphate level in whole platelets within 10 sec. On the other hand, the 14C-cyclic AMP level in the P, fraction decreased by about 80% of the control value while the total cyclic AMP in this fraction was almost unchanged. This rapid and striking fall in the membrane 14C-cyclic AMP level could be correlated with the more than 2fold stimulation of the membrane-bound cyclic AMP phosphodiesterase, together with the more than 20% inhibition of both the cyclic AMP-binding capacity and the adenyl cyclase in platelet membranes by thrombin treatment. These observations suggest the possibility that functional pool of cyclic AMP related to thrombin-induced aggregation is located in rabbit platelet plasma membrane.


1963 ◽  
Vol 9 (1) ◽  
pp. 111-115 ◽  
Author(s):  
Arnold L. Demain

Lysineless mutants of Saccharomyces cerevisiae were able to grow in liquid medium supplemented with L-lysine or DL-α-aminoadipic acid but not with D-α-aminoadipic acid. Nearospora crassa strain 33933, on the other hand, grew in the presence of D-α-aminoadipic acid as the sole nutritional supplement. Growth was less efficient with D-α-aminoadipic acid than with the DL-form or with L- or DL-lysine, but the presence of a small amount of one of these latter compounds allowed maximal utilization of the D-α-aminoadipic acid. Acid-hydrolyzed cephalosporin C, but not untreated cephalosporin C, also served as a source of the nutritional requirement.


Dialogue ◽  
2000 ◽  
Vol 39 (3) ◽  
pp. 461-474
Author(s):  
Gérard Sondag

AbstractIn reaffirming the intimate link between mind and life, John Duns Scotus is faithful to Augustine. His conception of the rational soul, however, differs from Augustine's trinitarian image, since he stresses the difference between intellect and memory on the one hand, and will on the other hand. He also departs from Augustine by attributing, in his theory of intelligible species, a real, if partial, causal role to the external object in their generation. The principle that there cannot be more reality in an effect than in its cause is true only of the total cause, and not of a partial cause, because an inferior partial cause can concur with a superior partial cause, such as the intellect, to produce a common effect, the perfection of which surpasses its own.


1983 ◽  
Vol 61 (10) ◽  
pp. 1202-1205 ◽  
Author(s):  
Raju V. K. Vegesna ◽  
Jack Diamond

The effects of isoproterenol and forskolin on cyclic AMP levels and tension were compared in helical strips of bovine coronary artery. Both compounds produced time- and dose-dependent increases in cyclic AMP levels and both compounds relaxed potassium-contracted arteries. However, in contrast to the results with isoproterenol, cyclic AMP elevation and relaxation were not well correlated at lower concentrations of forskolin. For example, 0.1 μM forskolin increased cyclic AMP levels in the arteries by approximately 5.5-fold but did not relax the muscles. A smaller elevation of cyclic AMP produced by 1.0 μM isoproterenol, on the other hand, was accompanied by an almost complete relaxation of the arteries. These results suggest that either cyclic AMP is not responsible for the relaxation caused by these agents, or some form of functional compartmentalization of cyclic AMP exists in this tissue.


2018 ◽  
Vol 33 (13) ◽  
pp. 1850066 ◽  
Author(s):  
Z. Derakhshani ◽  
M. Ghominejad

In this paper, the behavior of a Duffin–Kemmer–Petiau (DKP) boson particle in the presence of a harmonic energy-dependent interaction, under the influence of an external magnetic field is precisely studied. In order to exactly solve all equations in commutative (C), non-commutative (NC) and non-commutative phase (NCP) frameworks, the Nikiforov–Uvarov (NU) powerful exact approach is employed. All these attempts end up with solving their quartic equations, trying to find and discuss on their discriminant function [Formula: see text], in a unique way which has never been discussed for any boson in any other research, especially for the boson [Formula: see text] on which, we have been exclusively concerned. We finally succeeded to obtain the exact energy spectrums and wave functions under the effects of NC and NCP parameters and energy-dependent interaction on energy eigenvalues. In this step, we analyze the behaviors of their quartic energy eigenvalue polynomials in three sections and accurately compare all achieved physical-admissible roots one by one. This comparison surprisingly shows that the NC and NCP effects on the other hand, and the assumed harmonic energy-dependent interaction on the other hand, have almost the same order of perturbation effects for limited amounts of the magnetic field in a system of DKP bosons. Furthermore, through some calculations within this paper, we came up with a very crucial point about the NU method which was mistakenly being used in many papers by several researchers and improved it to be used safely.


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