Search results for "Involution"

Do Australopithecus aos ciborgues. Estamos diante do fim da evolução humana?.

2020

Abstract Social implementation of post-humanism could affect the biological evolution of living beings and especially that of humans. This paper addresses the issue from the biological and anthropological-philosophical perspectives. From the biological perspective, reference is made first to the evolution of hominids until the emergence of Homo sapiens, and secondly, to the theories of evolution with special reference to their scientific foundation and the theory of extended heredity. In the anthropological-philosophical part, the paradigm is presented according to which human consciousness, in its emancipatory zeal against biological nature, must “appropriate” the roots of its physis to tr…

Isoform-specific function of calpains in cell adhesion disruption: studies in postlactational mammary gland and breast cancer.

2016

Cleavage of adhesion proteins is the first step for physiological clearance of undesired cells during postlactational regression of the mammary gland, but also for cell migration in pathological states such as breast cancer. The intracellular Ca2+-dependent proteases, calpains (CAPNs), are known to cleave adhesion proteins. The isoform-specific function of CAPN1 and CAPN2 was explored and compared in two models of cell adhesion disruption: mice mammary gland during weaning-induced involution and breast cancer cell lines according to tumor subtype classification. In both models, E-cadherin, β-catenin, p-120, and talin-1 were cleaved as assessed by western blot analysis. Both CAPNs were able …

Role of Vitamin A in Mammary Gland Development and Lactation

2019

Vitamin A (all-trans-retinol), its active derivatives retinal and retinoic acid, and their synthetic analogues constitute the group of retinoids. It is obtained from diet either as preformed vitamin A or as carotenoids. Retinal plays a biological role in vision, but most of the effects of vitamin A are exerted by retinoic acid, which binds to nuclear receptors and regulates gene transcription. Vitamin A deficiency is an important nutritional problem, particularly in the developing world. Retinol and carotenoids from diet during pregnancy and lactation influence their concentration in breast milk, which is important in the long term, not only for the offspring, but also for maternal health. …

Varieties of algebras with pseudoinvolution and polynomial growth

2017

Let A be an associative algebra with pseudoinvolution (Formula presented.) over an algebraically closed field of characteristic zero and let (Formula presented.) be its sequence of (Formula presented.) -codimensions. We shall prove that such a sequence is polynomially bounded if and only if the variety generated by A does not contain five explicitly described algebras with pseudoinvolution. As a consequence, we shall classify the varieties of algebras with pseudoinvolution of almost polynomial growth, i.e. varieties of exponential growth such that any proper subvariety has polynomial growth and, along the way, we shall give also the classification of their subvarieties. Finally, we shall de…

Polynomial identities with involution and the hyperoctahedral group

1987

EphrinB2 controls vessel pruning through STAT1-JNK3 signalling

2014

Angiogenesis produces primitive vascular networks that need pruning to yield hierarchically organized and functional vessels. Despite the critical importance of vessel pruning to vessel patterning and function, the mechanisms regulating this process are not clear. Here we show that EphrinB2, a well-known player in angiogenesis, is an essential regulator of endothelial cell death and vessel pruning. This regulation depends upon phosphotyrosine-EphrinB2 signalling repressing c-jun N-terminal kinase 3 activity via STAT1. JNK3 activation causes endothelial cell death. In the absence of JNK3, hyaloid vessel physiological pruning is impaired, associated with abnormal persistence of hyaloid vessel…

Varieties of algebras with pseudoinvolution: Codimensions, cocharacters and colengths

2022

Abstract Let A be a finitely generated superalgebra with pseudoinvolution ⁎ over an algebraically closed field F of characteristic zero. In this paper we develop a theory of polynomial identities for this kind of algebras . In particular, we shall consider three sequences that can be attached to Id ⁎ ( A ) , the T 2 ⁎ -ideal of identities of A: the sequence of ⁎-codimensions c n ⁎ ( A ) , the sequence of ⁎-cocharacter χ 〈 n 〉 ⁎ ( A ) and the ⁎-colength sequence l n ⁎ ( A ) . Our purpose is threefold. First we shall prove that the ⁎-codimension sequence is eventually non-decreasing, i.e., c n ⁎ ( A ) ≤ c n + 1 ⁎ ( A ) , for n large enough. Secondly, we study superalgebras with pseudoinvoluti…

POLYNOMIAL GROWTH OF THE*-CODIMENSIONS AND YOUNG DIAGRAMS

2001

Let A be an algebra with involution * over a field F of characteristic zero and Id(A, *) the ideal of the free algebra with involution of *-identities of A. By means of the representation theory of the hyperoctahedral group Z 2wrS n we give a characterization of Id(A, *) in case the sequence of its *-codimensions is polynomially bounded. We also exhibit an algebra G 2 with the following distinguished property: the sequence of *-codimensions of Id(G 2, *) is not polynomially bounded but the *-codimensions of any T-ideal U properly containing Id(G 2, *) are polynomially bounded.

A Star-Variety With Almost Polynomial Growth

2000

Abstract Let F be a field of characteristic zero. In this paper we construct a finite dimensional F -algebra with involution M and we study its ∗ -polynomial identities; on one hand we determine a generator of the corresponding T -ideal of the free algebra with involution and on the other we give a complete description of the multilinear ∗ -identities through the representation theory of the hyperoctahedral group. As an outcome of this study we show that the ∗ -variety generated by M , var( M , ∗ ) has almost polynomial growth, i.e., the sequence of ∗ -codimensions of M cannot be bounded by any polynomial function but any proper ∗ -subvariety of var( M , ∗ ) has polynomial growth. If G 2 is…

Involution codimensions and trace codimensions of matrices are asymptotically equal

1996

We calculate the asymptotic growth oft n (M p (F),*) andc n (M p (F),*), the trace and ordinary *-codimensions ofp×p matrices with involution. To do this we first calculate the asymptotic growth oft n and then show thatc n ⋍t n .