3,439 research outputs found
Topological entropy for locally linearly compact vector spaces
By analogy with the topological entropy for continuous endomorphisms of totally disconnected locally compact groups, we introduce a notion of topological entropy for continuous endomorphisms of locally linearly compact vector spaces. We study the fundamental properties of this entropy and we prove the Addition Theorem, showing that the topological entropy is additive with respect to short exact sequences. By means of Lefschetz Duality, we connect the topological entropy to the algebraic entropy in a so-called Bridge Theorem
Neuropragmatics: Extralinguistic communication after closed head injury
This work is concerned with the decay of communicative abilities after head trauma. A protocol composed of 16 videotaped scenes was devised in order to investigate the comprehension of several types of communicative actions realized with extralinguistic means, like pointing or clapping. The protocol was administered to 30 closed head injured individuals. The results showed a decreasing performance from simple standard acts, to complex standard acts, deceits, and ironies. The subjects' performance was worse with the scenes reproducing failing, rather than successful, communicative actions. The results are compared with those we previously obtained with a linguistic protocol. A theory of the cognitive processes underlying intentional communication is outlined and used to explain the results
Marielle Trolet Ndiaye, Femme blanche, Afrique noire
Marielle, voce narrante e protagonista di questo romanzo è una donna francese apparentemente realizzata ma in realtà insoddisfatta, che decide di fare un viaggio in Senegal. Qui si sente inspiegabilmente subito a suo agio («Je me sentais comme un poisson dans l’eau au milieu de la foule des Dakarois. J’étais une des leurs, mais j’étais blanche», p. 14) tanto che poco a poco decide di trasferirsi a Popenguine, un villaggio di pescatori dove incontrerà Tamsir e se ne innamorerà . Più che una sto..
Alia Baccar Bournaz, Essai sur la littérature tunisienne d’expression française
Con questa raccolta di saggi critici Alia Baccar si propone di far conoscere la vasta produzione letteraria tunisina di espressione francese che, a suo giudizio, resta ancor oggi in gran parte sconosciuta. Appoggiandosi a numerose fonti storiche, letterarie e mitologiche, Alia Baccar offre al lettore un’opera composita, articolata in tre sezioni. La prima riunisce vari interventi dell’autrice a convegni e incontri in Italia, Canada, Stati Uniti, Francia, che trattano alcune tematiche tipiche ..
Hélé Béji, Une force qui demeure
Sebbene in copertina appaia la parola “essai”, Hélé Béji definisce giustamente il suo ultimo libro una “autobiographie réflexive”: si tratta infatti di un saggio dagli accenti fortemente personali. In 41 brevissimi capitoli la scrittrice si propone l’ambizioso progetto di scardinare ogni cliché sulla donna araba legato alla sua presunta sottomissione e fragilità offrendone al lettore un ritratto del tutto nuovo e inatteso, che la avvicina alla donna occidentale. Il testo si apre con un Je inv..
Amina Saïd, Au présent du monde
Con questa raccolta la scrittrice tunisina francofona offre al lettore una riflessione sulla scrittura e sull’arte della poesia, nonché sulla vita e sul suo senso più profondo. Una lunga dedica in forma di poesia introduce un’unica sezione di circa sessanta componimenti dai toni ora più intimi e personali ora più discorsivi ed esistenziali, percorsi dalle tematiche spesso intrecciate dell’ erranza e della scrittura. Poesie che parlano della forza dell’amore, dei ricordi d’infanzia, del silenz..
Deepening inside the pictorial layers of Etruscan sarcophagus of Hasti Afunei: An innovative micro-sampling technique for Raman/SERS analyses
The Hasti Afunei sarcophagus is a large Etruscan urn, made up of two chalky alabaster monoliths. Dated from the last quarter of the third century BC, it was found in 1826 in the small town of Chiusi (Tuscany- Il Colle place) by a landowner, Pietro Bonci Casuccini, who made it part of his private collection. The noble owner’s collection was sold in 1865 to the Royal Museum of Palermo (today under the name of Antonino Salinas Regional Archaeological Museum), where it is still displayed. The sarcophagus is characterized by a complex iconography that is meticulously illustrated through an excellent sculptural technique, despite having subjected to anthropic degradation and numerous restorative actions during the last century. During the restoration campaign carried out between 2016 and 2017, a targeted diagnostic campaign was carried out to identify the constituent materials of the artefact, the pigments employed and the executive technique, in order to get an overall picture of conservation status and conservative criticalities. In particular, this last intervention has allowed the use of the innovative micro-sampling technique, patented by the Cultural Heritage research group of Sapienza, in order to identify the employee of lake pigments through SERS analyses. Together with this analysis, Raman and NMR technique have completed the information requested by restorers, for what concerns the wax employed as protective layers, and allowed to rebuild the conservation history of the sarcophagus. In fact, together with the identification of red ocher and yellow ocher, carbon black, Egyptian blue and madder lake, pigments compatible with the historical period of the work, modern pigments (probably green Paris, chrome orange, barium yellow, blue phtalocyanine) have been recognized, attributable with not documented intervention during the eighteenth and twentieth centuries. © 2019 by the authors
Effect of probiotic inocula on the population density of lactic acid bacteria and enteric pathogens in the intestine of weaning piglets
Because antibiotic resistance occurs in bacteria at an alarming rate, significant research has been focused on finding alternative treatments which do not involve the use of antibiotics.
The promotion of beneficial gut bacteria can increase the resistance of animals to possible intestinal infections.
Probiotics can be administered to humans or animals, offering preventive benefits of protecting the host from various types of intestinal diseases, providing positive effects on digestive processes and stimulating influence on the growth of organism, strengthening the barrier function of the gut microbiota and/or non-specific enhancement of the immune system.
A study was designed to screen potential probiotic Bifidobacterium spp. strains with the ability to multiply in the intestine of weaned piglets and then to assess their health promoting effects when challenged with two enteric pathogens.
Three series of trials were conducted with 60 weaning pigs fed one of 12 different Bifidobacterium spp. strains either once or twice a day.
The most effective probiotic treatment (Bifidobacterium animalis subsp. lactis, strain Ra 18, at a dose of 1011cfu twice a day) was then challenged in two series of experiments with the enteric pathogens, Salmonella enterica serovar typhimurium and E. coli K88.
Bifidobacterium animalis subsp. lactis strain Ra 18 significantly increased (p<0.01) the number of viable bifidobacteria in the cecum contents. When it was challenged with Salmonella, Ra 18 reduced excretion of this pathogen with the faeces. On the whole, supplementation with Ra 18 had a positive effect on the growth performance of pigs except after challenge with E. coli K88 where pigs susceptible to ETEC adhesion were lighter than pigs not susceptible
A catalogue of nuclear stellar velocity dispersions of nearby galaxies from \u2009H\u3b1 STIS spectra to constrain supermassive black hole masses
We present new measurements for the nuclear stellar velocity dispersion \u3c3* within sub-arcsecond apertures for 28 nearby galaxies. Our data consist of Space Telescope Imaging Spectrograph (STIS) long-slit spectra obtained with the G750M grating centred on the H\u3b1 spectral range. We fit the spectra using a library of single stellar population models and Gaussian emission lines, while constraining in most cases the stellar-population content from an initial fit to G430L STIS spectra. We illustrate how these \u3c3* measurements can be useful for constraining the mass M\u2022 of supermassive black holes (SBHs) by concentrating on the cases of the lenticular galaxies NGC 4435 and NGC 4459. These are characterized by similar ground-based half-light radii stellar velocity dispersion \u3c3e values but remarkably different M\u2022 as obtained from modelling their central ionized-gas kinematics, where NGC 4435 appears to host a significantly undermassive SBH compared to what is expected from the M\u2022 - \u3c3e relation. For both galaxies, we build Jeans axisymmetric dynamical models to match the ground-based stellar kinematics obtained with Spectrographic Areal Unit for Research on Optical Nebulae integral-field spectrograph, including an SBH with M\u2022 value as predicted by the M\u2022 - \u3c3e relation and using high-resolution HST images taken with the Advanced Camera for Surveys to construct the stellar-mass model. By mimicking the HST observing conditions we use such reference models to make a prediction for the nuclear \u3c3* value. Whereas this was found to agree with our nuclear \u3c3* measurement for NGC 4459, for NGC 4435 the observed \u3c3* is remarkably smaller than the predicted one, which further suggests that this galaxy could host an undermassive SBH
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