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  • Gröbner bases  (3)
  • Rat  (3)
  • Androgen receptor  (2)
  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Advances in computational mathematics 12 (2000), S. 335-362 
    ISSN: 1572-9044
    Keywords: ideal bases ; Gröbner bases ; multivariate polynomials ; interpolation ; systems of polynomial equations ; 65D05 ; 65H10 ; 13P10
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mathematics
    Notes: Abstract The H-basis concept allows, similarly to the Gröbner basis concept, a reformulation of nonlinear problems in terms of linear algebra. We exhibit parallels of the two concepts, show properties of H-bases, discuss their construction and uniqueness questions, and prove that n polynomials in n variables are, under mild conditions, already H-bases. We apply H-bases to the solution of polynomial systems by the eigenmethod and to multivariate interpolation.
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  • 2
    Electronic Resource
    Electronic Resource
    Springer
    Research in experimental medicine 187 (1987), S. 287-294 
    ISSN: 1433-8580
    Keywords: Androgen receptor ; Dihydrotestosterone ; Ontogeny ; Puberty ; Prostate
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Concentrations of cytosolic androgen receptor, DNA and soluble protein, contents of DHT, and in-vivo uptake of3H-DHT were measured in rat ventral prostates at 5-day intervals during sexual development. Regarding prostate weight two phases of growth were noted being separated by a period of stagnation from Day 40 to 45. Cytosolic androgen receptor, particle-bound DHT, and uptake of3H-DHT into the 100,000-g sediment showed a clear pattern: a maximum in the prepubertal animal at age Day 20, a minimum at age Day 30 (4 days after the early pubertal rise of LH, testosterone, and DHT) followed by a second maximum on Day 55 (2 days before the beginning of fertility), and a second minimum in the young mature animal on Day 70. An intermediate peak seen at age Day 37 was not significant. Neither the time-dependent profile of the cytosolic androgen receptor nor the contents and in vivo uptake of DHT were correlated to concentrations of circulating gonadotrophins, growth hormone, and sex-steroids measured during puberty in the same strain of animals. Therefore, the regulating mechanism remains unclear.
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  • 3
    Electronic Resource
    Electronic Resource
    Springer
    Research in experimental medicine 188 (1988), S. 451-462 
    ISSN: 1433-8580
    Keywords: Androgen receptor ; Diurnal rhythm ; Rat ventral prostate ; Seasonal rhythm ; Testosterone
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Low- and high-salt (600 mM KCl) extractable androgen receptors were measured in the ventral prostate lobes of 70-day-old rats which were housed in constant environmental conditions (22 ± 2°C, 65 ± 5% air humidity, light 6.00 h–18.00 h). Seasonal variations were observed during 2 years, exhibiting elevations in late summer and autumn and depressions in late winter and spring time. These fluctuations were superposed by steep changes from month to month. The maximum and minimum values of the low- and high-salt extractable receptors differed within 1 year by a factor 8.5 and 2.4, respectively. Both receptor fractions showed a diurnal rhythm as measured during 1 day in January with maximal concentrations at 9.00 h (low-salt: median = 1 308 fmol/mg DNA) and minimal values at 18.00 (424) and 24.00 (230). The electrophoretic mobility in agar gel of pH 8.2 also showed a diurnal variation with maximal values at 18.00 h in either receptor fraction. Neither the seasonal nor the diurnal variations were correlated to the corresponding rhythms of serum testosterone concentrations. As steroid receptors may be regulated by neural transmission, in a final experiment the parasympathic innervation of the prostate was blocked by infiltrating the plexus pelvicus with a local anesthetic drug. One hour later, the total receptor concentration was not changed, while the ratio of low- to high-salt extractable receptors and the electrophoretic mobility of both fractions were elevated as compared to the control animals. This finding indicates that peripheral neural transmission rather than circulating testosterone may be involved in the regulation of androgen receptors in rat ventral prostate.
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  • 4
    Electronic Resource
    Electronic Resource
    Springer
    Applicable algebra in engineering, communication and computing 4 (1993), S. 103-145 
    ISSN: 1432-0622
    Keywords: Gröbner bases ; Polynomial ideals ; Dual bases ; Interpolation ; 0-dimensional schemes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Computer Science , Mathematics , Technology
    Notes: Abstract In this paper we study 0-dimensional polynomial ideals defined by a dual basis, i.e. as the set of polynomials which are in the kernel of a set of linear morphisms from the polynomial ring to the base field. For such ideals, we give polynomial complexity algorithms to compute a Gröbner basis, generalizing the Buchberger-Möller algorithm for computing a basis of an ideal vanishing at a set of points and the FGLM basis conversion algorithm. As an application to Algebraic Geometry, we show how to compute in polynomial time a minimal basis of an ideal of projective points.
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  • 5
    Electronic Resource
    Electronic Resource
    Springer
    Applicable algebra in engineering, communication and computing 4 (1993), S. 217-230 
    ISSN: 1432-0622
    Keywords: Algebraic variety decomposition ; Gröbner bases ; Systems of nonlinear equations
    Source: Springer Online Journal Archives 1860-2000
    Topics: Computer Science , Mathematics , Technology
    Notes: Abstract This paper deals with systems ofm polynomial equations inn unknown, which have only finitely many solutions. A method is presented which decomposes the solution set into finitely many subsets, each of them given by a system of type $$f_1 \left( {x_1 } \right) = 0,f_2 \left( {x_1 ,x_2 } \right) = 0, \ldots ,f_n \left( {x_1 , \ldots ,x_n } \right) = 0$$ . The main tools for the decomposition are from ideal theory and use symbolical manipulations. For the ideal generated by the polynomials which describe the solution set, a lexicographical Gröbner basis is required. A particular element of this basis allows the decomposition of the solution set. By a recursive application of these decomposition techniques the triangular subsystems are finally obtained. The algorithm gives even for non-finite solution sets often also usable decompositions.
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  • 6
    Electronic Resource
    Electronic Resource
    Springer
    Psychopharmacology 93 (1987), S. 182-187 
    ISSN: 1432-2072
    Keywords: Nomifensine ; B-HT 920 ; Dopamine receptors ; Conditioning ; Dopamine-mediated behaviours ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Conditioning of behavioural effects produced by two drugs acting differently upon dopaminergic neurotransmission was studied. Nomifensine and the putative dopamine autoreceptor agonist B-HT 920 produce contrasting effects on motility, namely increases in locomotor activity and stereotypies as compared to hypokinesia and ptosis. The administration of each of these drugs (US) was repeatedly associated with well-defined environmental stimuli (CS): a wire cage associated with an auditory and on olfactory stimulus. The rats were conditioned for 7 days with 20 mg/kg nomifensine IP each day. After conditioning, the rats were treated with the solvent alone in presence of the CS. Not only did sniffing and licking occur, but also gnawing, even though the latter response was not evident after acute administration of the drug or during the conditioning period. Nomifensine (20 mg/kg IP) also acutely decreased the ratio of 3,4-dihydroxyphenylacetic acid/dopamine concentrations (DOPAC/DOPAMINE); this ratio was not altered in the conditioned rats, 60 min after solvent administration in presence of the CS. Rats were conditioned with 0.02 mg/kg IP B-HT 920 daily for 8 days. During the conditioning phase, akinesia and ptosis showed a slight enhancement and a faster onset. After conditioning, when the rats were treated with the solvent alone, the majority of them showed akinesia and/or ptosis during the observation period, in contrast to pseudoconditioned controls. When these rats were conditioned or pseudoconditioned, respectively, with B-HT 920 for further 5 days using 0.02 mg/kg again, treatment with the same dose in presence of the CS produced a significant enhancement and acceleration of these signs in conditioned as compared with pseudoconditioned control rats. The results show that stereotypies producd by nomifensine and akinesia and ptosis produced by B-HT 920 can be conditioned and that, in addition, a sign of stereotypies which was not manifest during the conditioning period appeared as conditioned response.
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  • 7
    ISSN: 1432-2072
    Keywords: Apomorphine ; Conditioned dopaminergic activity ; Stereotyped behaviour ; Dopamine autoreceptors ; Dopamine metabolism ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract We investigated whether pharmacological effects of the dopamine agonist apomorphine can be conditioned by establishing an association of apomorphine administration with exteroceptive cues. Apomorphine was repeatedly administered and subsequently, the rat was put into a test cage and exposed to an acoustic and an olfactory stimulus (“conditioned rats”). Control animals (“pseudoconditioned” rats) were treated with the same pharmacological schedule of apomorphine not temporally associated with the stimuli. On the test day, both groups were injected with saline and exposed to the stimuli described. The stereotyped behaviour produced by large doses of apomorphine (0.5 or 2.0 mg/kg SC), namely sniffing, licking and gnawing, could be conditioned in a pronounced way. During the conditioning period, a change in the stereotypies was observed with regard to the time-course (earlier occurrence) and to the character of the stereotypies (from sniffing to licking and gnawing), when 0.5 mg/kg apomorphine was used, but not with the dose of 2.0 mg/kg. The conditioned responses showed a relatively uniform distribution during the observation period with some increase towards the end of the observation period. Some signs produced by a low dose of apomorphine (0.07 mg/kg SC), namely hypomotility and ptosis, but not yawning, could also be conditioned, although in a less pronounced way. An intermediate dose of apomorphine (0.18 mg/kg SC) produced both signs observed after large doses and those observed after a small dose, occurring alternatingly. Both types of signs could be conditioned using this dosage. Conditioning did not alter striatal or mesolimbic dopamine turnover. These results suggest that only behavioural signs due to an activation of postsynaptic dopamine receptors, but also some symptoms produced by an activation of dopamine autoreceptors can be conditioned.
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  • 8
    ISSN: 1432-2072
    Keywords: Apomorphine ; Stereotypy ; Environmental influence ; Automatic recording ; Dopamine ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The topography of stereotyped behaviour produced by apomorphine in rats was studied by using either a scoring system, based on observation in a wire cage, or by quantification of horizontal and vertical activities, and of the total distances run in an open field, using an automatic recording system. The latter design was combined with a classification of the type of stereotyped behaviour observed during recording. In addition, the reproducibility of the nature of the stereotyped behaviour and its dose-dependence in individual animals was evaluated. In rats observed in a wire cage, apomorphine at lower doses (0.25 or 0.50 mg/kg SC) produced stereotyped sniffing. Increasing the doses led to stereotyped licking and the largest dose (5.00 mg/kg SC) produced predominantly stereotyped gnawing, as was demonstrated graphically. The type of behaviour produced by 2 mg/kg apomorphine in the open field was reproduced well in individuals after a second administration 4 days later. The shift from sniffing to gnawing was observed in most, but not all of the individually classified animals after administration of the largest dose (5 mg/kg). The locomotor part of motility was highest in “sniffing animals” and lower when gnawing occurred. The non-locomotor part of motility was low in “sniffing rats” and increased when licking and gnawing occurred. In some of the animals a characteristic “climbing” behaviour was observed in addition after the larger doses, which did not interfere with sniffing, licking or gnawing. A combination of classification by observation and automatic recording seems the most appropriate way to study the topography of stereotyped behaviour produced by apomorphine.
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