Search results for " Complement"

Esperienze con studenti italiani e cinesi: processi cognitivi e soluzioni di problemi matematici.

2011

Uno dei problemi più interessanti che si pongono oggi è certamente quello di confrontarsi con la “diversabilità” in situazioni di multicultura, realtà ormai presente nella nostra società, in continuo mutamento socio-culturale, e quindi nodo centrale per la ricerca in didattica della Matematica e non solo. Se infatti i fenomeni di insegnamento/apprendimento delle discipline hanno già sistemi complessi di indagine, la “diversabilità multiculturale” ne aumenta notevolmente la complessità. Ogni persona, appartenente ad una stessa cultura, possiede differenze cognitive rispetto ai suoi simili; in ambienti multiculturali queste si sommano a quelle riscontrabili nei diversi saperi che interagiscon…

Problems with variation: an educational experience of cultural transposition with prospective primary teachers

2022

The paper presents some theoretical reflections and some methodological notes about a Professional Development (PD) path worked out during the last two years by Italian researchers for prospective Primary teachers. The theoretical construct of Cultural Transposition defines the framework of the PD path's activities and the related research. It was used to define an interesting cultural lent to delineate possible new approaches for effective pre-service teacher education programs, in particular for the Primary level. The defined methodology was based on the possibility to reflect about the decentralization of didactic practices based on a specific cultural context through one or more contact…

Differentiation-associated apoptosis of neural stem cells is effected by Bcl-2 overexpression: impact on cell lineage determination

2001

Apoptosis is an integral part of neural development. To elucidate the importance of programmed cell death on cell lineage determination we utilized murine PCC7-Mzl cells, a model system for neural differentiation. Treatment of pluripotent PCC7-Mzl stem cells with 0.1 microM all-trans retinoic acid (RA) causes a cease of proliferation and an initiation of differentiation into neurons, glial cells and fibroblasts. Simultaneously, a fraction of the cell culture (ca. 25%) dies within 24 h by apoptosis. We transfected PCC7-Mzl cells with the human bcl-2 cDNA and generated PCC7-Mz-Bcl-2 cell lines expressing two- to tenfold higher levels of Bcl-2 than parental cells. Overexpression of Bcl-2 resul…

cARTegory Theory: Framing Aesthetics of Mathematics

2019

Mathematics can help investigate hidden patterns and structures in music and visual arts. Also, math in and of itself possesses an intrinsic beauty. We can explore such a specific beauty through the comparison of objects and processes in math with objects and processes in the arts. Recent experimental studies investigate the aesthetics of mathematical proofs compared to those of music. We can contextualize these studies within the framework of category theory applied to the arts (cARTegory theory), thanks to the helpfulness of categories for the analysis of transformations and transformations of transformations. This approach can be effective for the pedagogy of mathematics, mathematical mu…

Diverse cell surface protein ectodomains are shed by a system sensitive to metalloprotease inhibitors.

1996

The extracellular domains of a diverse group of membrane proteins are shed in response to protein kinase C activators such as phorbol 12-myristate 13-acetate (PMA). The lack of sequence similarity in the cleavage sites suggests the involvement of many proteases of diverse specificity in this process. However, a mutant Chinese hamster ovary cell line recently isolated for being defective in PMA-activated shedding of the membrane-anchored growth factor transforming growth factor alpha precursor (proTGF-alpha) is concomitantly defective in the shedding of many other unrelated membrane proteins. Here we show that independent mutagenesis and selection experiments yield shedding mutants having th…

Cloning of Sponge (Geodia cydonium) and Tunicate (Botryllus schlosseri) Proteasome Subunit Epsilon (PRCE): Implications about the Vertebrate MHC-Enco…

1996

Proteasomes are large protein complexes that play a major role in selective degradation of intracellular proteins. Eukaryotes feature seven different alpha and beta subunits. Two of the vertebrate housekeeping beta-subunits have MHC-encoded homologues that can substitute for the housekeeping counterparts upon interferon-gamma induction. In the present study we report the cloning of invertebrate beta-subunit proteasome epsilon (PRCE), from the marine sponge Geodia cydonium and from the colonial tunicate Botryllus schlosseri. Sequence comparisons revealed that the sponge and tunicate proteins are strikingly similar to vertebrate and yeast PRCEs and their MHC-linked counterparts the PRCCs (als…

Conformational clamping by a membrane ligand activates the EphA2 receptor

2021

AbstractThe EphA2 receptor is a promising drug target for cancer treatment, since EphA2 activation can inhibit metastasis and tumor progression. It has been recently described that the TYPE7 peptide activates EphA2 using a novel mechanism that involves binding to the single transmembrane domain of the receptor. TYPE7 is a conditional transmembrane (TM) ligand, which only inserts into membranes at neutral pH in the presence of the TM region of EphA2. However, how membrane interactions can activate EphA2 is not known. We systematically altered the sequence of TYPE7 to identify the binding motif used to activate EphA2. With the resulting six peptides, we performed biophysical and cell migratio…

The protease domain of procollagen C-proteinase (BMP1) lacks substrate selectivity, which is conferred by non-proteolytic domains.

2007

Abstract Procollagen C-proteinase (PCP) removes the C-terminal pro-peptides of procollagens and also processes other matrix proteins. The major splice form of the PCP is termed BMP1 (bone morphogenetic protein 1). Active BMP1 is composed of an astacin-like protease domain, three CUB (complement, sea urchin Uegf, BMP1) domains and one EGF-like domain. Here we compare the recombinant human full-length BMP1 with its isolated proteolytic domain to further unravel the functional influence of the CUB and EGF domains. We show that the protease domain alone cleaves truncated procollagen VII within the short telopeptide region into fragments of similar size as the full-length enzyme does. However, u…

A tunicate (Botryllus schlosseri) cDNA reveals similarity to vertebrate antigen receptors

1996

Complementation of Saccharomyces cerevisiae mutationsin genes involved in translation and protein folding (EFB1 and SSB1)with Candida albicans cloned…

2000

We have demonstrated that the expression of Candida albicans genes involved in translation and protein folding (EFB1 and SSB1) complements the phenotype of Saccharomyces cerevisiae mutants. The elongation factor 1beta (EF-1beta) is essential for growth and efb1 S. cerevisiae null mutant cells are not viable; however, viable haploid cells, carrying the disrupted chromosomal allele of the S. cerevisiae EFB1 gene and pEFB1, were isolated upon sporulation of a diploid strain which was heterozygous at the EFB1 locus and transformed with pEFB1 (a pEMBLYe23 derivative plasmid containing an 8-kb DNA fragment from the C. albicans genome which contains the EFB1 gene). This indicates that the C. albic…