Search results for "complement"
showing 10 items of 2113 documents
Le scienze matematiche in Sicilia dal riformismo settecentesco all'unità nazionale
2012
Il Carteggio Cremona-Guccia (1878-1900)
2013
Primi elementi di semiotica. La sua presenza e la sua importanza nel processo di insegnamento-apprendimento della matematica.
2013
Dall'inversione alle trasformazioni quadratiche
2012
Dall'inversione alle trasformazioni quadratiche Aldo Brigaglia (Università di Palermo) brig@math.unipa.it La inversione (o trasformazione per raggi vettori reciproci) è da considerarsi la prima trasformazione birazionale (non lineare) entrata in modo stabile nel novero di quelle trattate dai matematici. La stessa sua naturalezza ha reso nebulosa l’origine di questo concetto. In effetti si tratta della trasformazione che, fissato un punto A e un segmento r, associa ad ogni punto B il punto B’ sulla semiretta AB tale che AB’ sia il terzo proporzionale tra AB e r. Costruzioni di punti di questo genere sono presenti assai spesso: p. es. nella proiezione stereografica, in cui r è il diametro del…
Picard et les géomètres italiens: histoire des deux prix Bordin
2013
Dans mon intervention je chercherai à mettre au point la question des rapports entre Picard et les géomètres algébriques italiens, en particulier Enriques, Castelnuovo et Severi, en montrant comment si, d'un côté, les thèmes de recherche se croisent, d'un autre ils ont été développés en utilisant des langages mathématiques profondément différents au point de rendre parfois impossible ou presque la compréhension réciproque. Je chercherai aussi à donner un aperçu des rapports en théorie des nombres entre Picard et Bianchi et de l'influence de Corrado Segre et Fano sur Cartan qui à son tour eut une profonde influence sur Benjamin Segre.
La naturaleza estratégica del proceso de branding
2019
El branding, anglicismo con el que se denomina a la creación y gestión estratégica de una marca, cobró notoriedad en la década del ’90 incorporándose al debate académico y a la actividad profesional del campo disciplinar del diseño y el marketing. En ese trayecto provocó cierta confusión respecto a la naturaleza –a veces estratégica y a veces táctica– de la actividad. Este hecho da lugar a la reflexión teórica sobre el nuevo territorio y a explorar la actividad que rodea a la construcción de una marca, en un intento por descubrir perspectivas teóricas que ayuden a comprender el proceso. Al hacerlo, se examina la noción demarca como sistema bipolar de producción y proyección de imágenes, y s…
Engineering of chicken avidin: a progressive series of reduced charge mutants.
1998
Avidin, a positively charged egg-white glycoprotein, is a widely used tool in biotechnological applications because of its ability to bind biotin strongly. The high pI of avidin (approximately 10.5), however, is a hindrance in certain applications due to non-specific (charge-related) binding. Here we report a construction of a series of avidin charge mutants with pIs ranging from 9.4 to 4.7. Rational design of the avidin mutants was based on known crystallographic data together with comparative sequence alignment of avidin, streptavidin and a set of avidin-related genes which occur in the chicken genome. All charge mutants retained the ability to bind biotin tightly according to optical bio…
Molecular cloning and nucleotide sequence of chicken avidin-related genes 1-5.
1994
Using avidin cDNA as a hybridisation probe, we detected a gene family whose putative products are related to the chicken egg-white avidin. Two overlapping genomic clones were found to contain five genes (avidin-related genes 1–5, avrl-avr5), which have been cloned, characterized and sequenced. All of the genes have a four-exon structure with an overall identity with the avidin cDNA of 88–92%. The genes appear to have no pseudogenic features and, in fact, two of these genes have been shown to be transcribed. The putative proteins share a sequence identity of 68–78% with avidin. The amino acid residues responsible for the biotin-binding activity of avidin and the bacterial biotin-binding prot…
Hybrid equilibrium element with high-order stress fields for accurate elastic dynamic analysis
2021
In the present article the two-dimensional hybrid equilibrium element formulation is initially developed, with quadratic, cubic, and quartic stress fields, for static analysis of compressible and quasi-incompressible elastic solids in the variational framework of the minimum complementary energy principle. Thereafter, the high-order hybrid equilibrium formulation is developed for dynamic analysis of elastic solids in the variational framework of the Toupin principle, which is the complementary form of the Hamilton principle. The Newmark time integration scheme is introduced for discretization of the stress fields in the time domain and dynamic analysis of both the compressible solid and qua…