6,316 research outputs found
Uncovering quasi-degenerate Kaluza-Klein Electro-Weak gauge bosons with top asymmetries at the LHC
No full textBy exploiting the correlation between charge and spin polarisation asymmetries in t-tbar, we show that combining the two observables could identify the presence of quasi-degenerate states in a resonant signal at the LHC. As an example, we investigate experimental signatures emerging in top-antitop final states in the context of a model where the Standard Model Electro-Weak sector is allowed to propagate in large extra--dimensions of TeV-1 size while the colour sector is localised. Assuming current experimental constraints from the 7 and 8 TeV runs and taking into account the estimated top (anti-top) reconstruction efficiencies, we find that the 14 TeV upgraded LHC with the planned integrated luminosity L=100 fb-1 could access these quasi-degenerate multiple resonances and explore for the first time the rich phenomenology in the asymmetry observables. The main outcome would be having measurable quantities, complementary to the usual total and differential cross sections, capable of distinguishing a quasi-degenerate multiply resonant spectrum from a 'standard' single resonance that could present a similar signal in a bump hunt analysis
Ways in which coherence is confirmation conducive
No full textRecent works in epistemology show that the claim that coherence is truth conducive – in the sense that, given suitable ceteris paribus conditions, more coherent sets of statements are always more probable – is dubious and possibly false. From this, it does not follows that coherence is a useless notion in epistemology and philosophy of science. Dietrich and Moretti 2005 have proposed a formal of account of how coherence is confirmation conducive – that is, of how the coherence of a set of statements facilitates the confirmation of such statements. This account is grounded in two confirmation transmission properties that are satisfied by some of the measures of coherence recently proposed in the literature. These properties explicate everyday and scientific uses of coherence. In his paper, I review the main findings of Dietrich and Moretti 2005 and define two evidence gathering properties that are satisfied by the same measures of coherence and constitute further ways in which coherence is confirmation conducive. At least one of these properties vindicates important applications of the notion of coherence in everyday life and in science
La Rede del 1807. Sua natura essoterica ed esoterica
No full textL'autore utilizza le nozioni di "essoterico" ed "esoterico" per interpretare i livelli espositivi e contenutistici del Discorso sul rapporto tra arti figurative e la natura tenuto da Schelling nel 1807
Ionization and speciation of water in silicate melts
No full textWater in silicate melts is commonly assumed to take the form of molecular water (H2Om) and hydroxyl groups (OH), the latter bounded to network formers (T) as T-OH groups. Although free hydroxyls (OH-) were only recently ascertained in depolymerized melts (Xue and Kanzaki, 2004), the amphoteric behavior of water, was already suggested long ago (Fraser, 1977) and preliminarily modelled considering redox data (Moretti, 2005). However, autoprotolysis of water has not been assessed in silicate melts hitherto, because of the rather complex nature of such a solvent. Here, a simple theoretical frame is developed based on the extended two-sublattice hypothesis of Temkin. The theory accounts for acid-base properties of the melt phase, and reconciles differing notations. An independent proof of our appraisal is given by an algorithmic approach to chemical equilibria between O and H in polymeric silicate melts. The assessment of the ionization constant of water in melts can explain the conditions at which precipitation of hydrous minerals can occur. Because of the amphoteric behavior, melt polymerization can be affected less than that normally perceived and assumed, depending on bulk composition. This has implications for the redox behavior, which is strictly connected to melt acid-base properties, hence polymerization. These connections must be accounted for when modelling magmatic equilibria.
REFERENCES:
FRASER DG (1977) In: Thermodynamics in Geology (D.G. Fraser, ed.), D. Reidel Pub. Co.
MORETTI R. (2005) Ann. Geophysics, 48, 503-608.
XUE, X. AND KANZAKI, M. (2004) Geochim. Cosmochim. Acta, 68, 5027-5057
Epistemologia (o della Conoscenza)
No full text’epistemologia (detta anche filosofia della conoscenza o gnoseologia) è la disciplina filosofica che studia come gli esseri umani si rapportano da un punto di vista cognitivo alla realtà che li circonda. Le questioni fondamentali che la interessano sono principalmente di natura normativa. Riguardano il modo in cui dovremmo regolare le nostre credenze alla luce dell’informazione in nostro possesso, e la natura della conoscenza umana ed i suoi limiti. Questo capitolo è organizzato in modo corrispondente. La prima sezione tratta della nozione di giustificazione epistemica, la seconda quella di conoscenza, e la terza introduce il problema filosofico dello scetticismo
Electroporation as a modern approach to the delivery of genetic constructs in cancer gene therapy
No full textVodilni vzrok smrti v razvitem svetu je poleg krvožilnih bolezni rak. Po podatkih IARC je leta 2020 na svetu za rakom zbolelo 19,3 milijonov ljudi, 10 milijonov jih je raku podleglo. Rak ali malignom ali maligni tumor je poligenska bolezen, ki nastane kot posledica mutacije ali epigenetske spremembe v dednem zapisu ene same celice in je trenutno še ne znamo pozdraviti. Nov obetajoč pristop zdravljenja raka je genska terapija, pri kateri v tumorske celice administriramo gene, njihove dele, oligonukleotide, miRNA in siRNA z namenom utišanja, znižanja regulacije, modifikacije ali popravljanja tarčnih celic. Terapijo vnašamo in vivo ali ex vivo s pomočjo dostavnih sistemov oz. vektorjev, ki jih grobo delimo na virusne in nevirusne. Velik potencial za transfekcijo celic ima elektroporacija gole plazmidne DNA zaradi varnosti in največje učinkovitosti med nevirusnimi vektorji. Elektroporacija je pojav tvorbe por na celični membrani, kar je posledica izpostavitve celic kratkim visokonapetostnim impulzom. Permeabilizirana membrana omogoča transport molekul različnih velikost v jedro. Po prenehanju delovanja električnega polja se membrana pri reverzibilni elektroporaciji povrne v prvotno stanje v določenem času (od nekaj milisekund do nekaj minut). Elektroporacijo uporabljamo pri imunski elektrogenski terapiji, kjer v tumorske celice vnašamo IL-12 plazmidno DNA. Gre za citokin, ki je zelo močan induktor protitumorske imunosti. Raziskovanje njegovega terapevtskega potenciala že poteka na predklinični in tudi na klinični ravni.Cancer is the leading cause of death in the developed world, alongside circulatory diseases. According to the IARC, 19.3 million people worldwide were diagnosed with cancer in 2020, and 10 million succumbed to cancer. Cancer, or malignancy or malignant tumour, is a polygenic disease that arises as a result of a mutation or epigenetic change in the genome of a single cell, and which currently has no cure. A promising new approach to cancer treatment is gene therapy, in which genes, gene parts, oligonucleotides, miRNAs and siRNAs are administered into tumour cells to silence, down-regulate, modify, or repair target cells. Therapy is administered in vivo or ex vivo using delivery systems or vectors, which are roughly divided into viral and non-viral. The electroporation of naked plasmid DNA has great potential for cell transfection due to its safety and the highest efficiency among non-viral vectors. Electroporation is the phenomenon of pore formation on the cell membrane resulting from the exposure of cells to short high-voltage pulses. The permeabilised membrane allows the transport of molecules of different sizes into the nucleus. After the electric field has ceased, the membrane returns to its original state within a certain time (from a few milliseconds to a few minutes) in reversible electroporation. Electroporation is used in immune electrogene therapy, where IL-12 plasmid DNA is injected into tumour cells. This is a cytokine that is a very potent inducer of antitumour immunity. Its therapeutic potential is already being tested at both pre-clinical and clinical levels
On the Lux-Flood basicity of melts in solving their chemical reactivity
No full textReactivity of silicate melts is due to charged functional groups (cations, free anions
and polymeric units or structons), which govern mutual interactions between
constituting oxides. The main problem arises when defining thermodynamic oxide
ion activities. This difficulty is overcome if we adopt the Fincham and Richardson
(1954) formalism coupled with a Toop and Samis (1962a,b) polymeric description of
the anion matrix, based on the principle of equal reactivity of co-condensing groups
and involving singly bonded, doubly bonded and free oxygen, that is oxygen species
in three different polarization states. In a chemically complex melt the capability
of transferring fractional electronic charges from the ligand to the central cation
depends in a complex fashion on the melt structure, affecting the polarization state
itself. Therefore, the mean polarization state of the various ligands (mainly oxide
ions in silicate melts) and their ability to transfer fractional electronic charges to the
central cation are conveniently represented by the optical basicity of the medium. On
this basis, Ottonello et al. (2001) related linearly the optical basicity to the extent of
the anionic matrix and hence to the polymerization constant. Although the adopted
functional form is rather brutal, not accounting for temperature effects, it allows
an accurate description of the anionic matrix which enable us to study the iron
oxidation state in both anhydrous and hydrous melts, then solving some controversies
present in literature, to define a consistent model for water speciation which accounts
for the amphoteric behavior of this component and to assess sulfur speciation and
solubility. The latter, in particular, was possible only through the adoption of the
Flood and Grjotheim (1952) thermochemical cycle, which accounts for the standard
state transposition between the Temkin standard state of completely dissociated
components and that of pure component at T and P of interest.
Recently, we applied the Hybrid Polymeric model (Ottonello, 2001) to assess silicate
melt energetics, distinguishing chemical interaction terms from strain energy contributions
(Ottonello and Moretti, 2004). Lux-Flood basic oxides give rise to purely
endothermic effects when admixed to silica along simple bianry joins, whereas acidic
Lux-Flood oxides originate thermal admixtures and amphoteric oxides promote both
enthalpic and entropic (non configurational) chemical interactions.
This makes the Lux-Flood acid-base character of the various oxides consistent
with experimental determinations of nephelauxetic properties of the limiting oxide
components in the mean donor ligand field, represented in terms of optical basicity.
A linear proportionality is observed between endothermic heat of mixing and optical
basicity which allows us to predict the polymerization extent in molten MO-SiO2
binaries.
The extension of this proportionality to complex systems requires the application of
the Flood-Grjotheim (1952) approach and allows us to shift the previously developed
models for iron, water and sulfur to a more rigorous treatment of the anionic matrix
of silicate melts.
REFERENCES
Fincham and Richardson (1954) Proc. Roy. Soc. London, 223A, 40.
Flood and Grjotheim (1952), J. Iron Steel Inst., 171, 64.
Toop and Samis (1962a) Can. Met. Quart., 1, 129.
Toop and Samis (1962b) Trans. Met. Soc. AIME, 224, 878.
Moretti (2003) Ann. Geophys. (submitted).
Moretti and Ottonello (2003a) Metall. Mat. Trans. B, 34B, 399.
Moretti and Ottonello (2003b) J. Non Cryst. Sol., 323, 111.
Ottonello (2001), J. Non Cryst. Sol., 282, 72.
Ottonello and Moretti (2004) J. Phys. Chem. Sol. (submitted).
Ottonello et al. (2001), Chem. Geol., 174, 157
“Il teatro Imperiale di Luigi Moretti. L’importanza del disegno nella concezione dello spazio.” Disegni inediti di L. Moretti. Una nuova lettura del Teatro Imperiale per E42
No full textL'articolo prende spunto da uno studio sull'opera di Moretti, in particolar modo Il Teatro Imperiale.
L'edificio, mai costruito, si trovava localizzato nel quartiere Eur. La rilettura di questo Progetto apre nuove ipotesi interpretative
A análise da linguagem matemática como elemento para pensar o ensino e a aprendizagem da prática de esboço de curvas no ensino superior: Adriano Luiz dos Santos Né ; orientador, Méricles Thadeu Moretti
No full textDissertação (mestrado) - Universidade Federal de Santa Catarina, Centro de Ciências Físicas e Matemáticas, Florianópolis, 2013Na presente pesquisa tenho a intenção de realizar uma investigação a respeito do processo de ensino e aprendizagem da prática de esboço de curvas do ensino superior, particularmente na disciplina de Cálculo. Para tal tarefa, buscarei estudar o uso que se faz da linguagem matemática em sala de aula, tomando como estudo de caso uma turma de estudantes da disciplina Cálculo A, da Universidade Federal de Santa Catarina. Nesta investigação, utilizarei-me de ferramentas teóricas fornecidas pela Teoria dos Registros de Representação Semiótica, de Raymond Duval, e o Enfoque Ontosemiótico, de Juan Dìaz Godino, o que atribui a esta pesquisa uma perspectiva semiótica da atividade matemática. A articulação que pretendo realizar com estas teorias parece fornecer informações importantes a respeito da prática matemática realizada pelos estudantes em sala de aula e a prática que a academia tem a intenção de ensinar, o que possibilita um meio de compará-las para então se intervir no processo de ensino e aprendizado da prática de esboço de curvas.Abstract : In this research I intend to conduct a investigation about the process of teaching and learning in the sketching curves practice on the higher education, particularly in the Calculus' discipline. For such task, I seek study the use made of mathematical language in the classroom, taking as case study a students' class of Calculus A discipline, from the Federal University of Santa Catarina (Brazil). In this research, I will use the theoretical tools provided by the Registers of Semiotic Representation's Theory, by Raymond Duval, and the Ontosemiotic Approach, by Juan Dìaz Godino, which attaches to the research a semiotic perspective of mathematical activity. The articulation that I intend to accomplish with these theories seem to provide important information about the mathematical practice performed by students in the classroom and the practice that the academy intends to teach, which provides a means to compare them and so intervene in the process of teaching and learning on the sketch curves practice
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