2,577 research outputs found
Il tema del âdoppioâ nel romanzo di A. Skaldin Stranstvia i prikljuÄenija Nikodima StarĆĄego
Lâ«inspiegabile divisione» (ĐœĐ”ĐžĐ·ŃŃŃĐœĐžĐŒĐŸĐ” ŃĐ°Đ·ĐŽĐ”Đ»Đ”ĐœĐžĐ”) psicofisica della personalitĂ sperimentata dal giovane barin Nikodim MichajloviÄ Ipatâev, protagonista del romanzo filosofico di Aleksej Skaldin Stranstvija i prikljuÄenija Nikodima StarĆĄego [Peregrinazioni e avventure di Nikodim il Vecchio]4, va certamente letta come un tributo dellâultimo (in ordine cronologico) dei simbolisti russi ad un tema di antica memoria, caro alla mitologia e alla classicitĂ â quello del âdoppioâ â, che, a partire da Pogorelâskij, passando per PuĆĄkin, Odoevskij, Gogolâ e Dostoevskij, aveva imperversato nellâOttocento russo e, prima ancora, nellâambiente letterario europeo barocco e romantico, confermandosi nel Novecento, secolo del relativismo e della crisi dellâio, come il tratto distintivo della modernitĂ . Eppure lo sdoppiamento, a detta di Pasolini «la piĂč grande delle invenzioni letterarie», se ricollega Skaldin alla grande tradizione culturale otto-novecentesca, Ăš un Leitmotiv che lâautore desume non da fonti esterne ma dallâintimo della propria esperienza personale. La mia analisi della scissione identitaria del Nikodim skaldiniano si basa appunto sullâipotesi di una totale o parziale identificazione dello scrittore con il suo personaggio, nella convinzione che solo un accurato esame del substratum autobiografico dellâopera ci possa restituire il significato e la funzione che in essa riveste il topos della destrutturazione e moltiplicazione dellâio
On Poincare and logarithmic Sobolev inequalities for a class of singular Gibbs measures
This note, mostly expository, is devoted to Poincar{\'e} and log-Sobolev
inequalities for a class of Boltzmann-Gibbs measures with singular interaction.
Such measures allow to model one-dimensional particles with confinement and
singular pair interaction. The functional inequalities come from convexity. We
prove and characterize optimality in the case of quadratic confinement via a
factorization of the measure. This optimality phenomenon holds for all beta
Hermite ensembles including the Gaussian unitary ensemble, a famous exactly
solvable model of random matrix theory. We further explore exact solvability by
reviewing the relation to Dyson-Ornstein-Uhlenbeck diffusion dynamics admitting
the Hermite-Lassalle orthogonal polynomials as a complete set of
eigenfunctions. We also discuss the consequence of the log-Sobolev inequality
in terms of concentration of measure for Lipschitz functions such as maxima and
linear statistics.Comment: Minor improvements. To appear in Geometric Aspects of Functional
Analysis -- Israel Seminar (GAFA) 2017-2019", Lecture Notes in Mathematics
225
Cardiovascular changes after administration of aerosolized salbutamol in horses: five cases
Prevention and treatment of intraoperative hypoxemia in horses is difficult and both efficacy and safety of therapeutic maneuvers have to be taken into account. Inhaled salbutamol has been suggested as treatment of hypoxia in horses during general anesthesia, due to safety and ease of the technique. The present report describes the occurrence of clinically relevant unwanted cardiovascular effects (i.e. tachycardia and blood pressure modifications) in 5 horses undergoing general anesthesia in dorsal recumbency after salbutamol inhalation. Balanced anesthesia based on inhalation of isoflurane in oxygen or oxygen and air and continuous rate infusion (CRI) of lidocaine, romifidine, or combination of lidocaine and guaifenesine and ketamine was provided. Supportive measures were necessary to restore normal cardiovascular function in all horses but no long-term adverse effects were noticed in any of the cases
Cyclic dermal BMP signalling regulates stem cell activation during hair regeneration
In the age of stem cell engineering it is critical to understand how stem cell activity is regulated during regeneration. Hairs are mini-organs that undergo cyclic regeneration throughout adult life1, and are an important model for organ regeneration. Hair stem cells located in the follicle bulge2 are regulated by the surrounding microenvironment, or niche3. The activation of such stem cells is cyclic, involving periodic -catenin activity4, 5, 6, 7. In the adult mouse, regeneration occurs in waves in a follicle population, implying coordination among adjacent follicles and the extrafollicular environment. Here we show that unexpected periodic expression of bone morphogenetic protein 2 (Bmp2) and Bmp4 in the dermis regulates this process. This BMP cycle is out of phase with the WNT/-catenin cycle, thus dividing the conventional telogen into new functional phases: one refractory and the other competent for hair regeneration, characterized by high and low BMP signalling, respectively. Overexpression of noggin, a BMP antagonist, in mouse skin resulted in a markedly shortened refractory phase and faster propagation of the regenerative wave. Transplantation of skin from this mutant onto a wild-type host showed that follicles in donor and host can affect their cycling behaviours mutually, with the outcome depending on the equilibrium of BMP activity in the dermis. Administration of BMP4 protein caused the competent region to become refractory. These results show that BMPs may be the long-sought 'chalone' inhibitors of hair growth postulated by classical experiments. Taken together, results presented in this study provide an example of hierarchical regulation of local organ stem cell homeostasis by the inter-organ macroenvironment. The expression of Bmp2 in subcutaneous adipocytes indicates physiological integration between these two thermo-regulatory organs. Our findings have practical importance for studies using mouse skin as a model for carcinogenesis, intra-cutaneous drug delivery and stem cell engineering studies, because they highlight the acute need to differentiate supportive versus inhibitory regions in the host skin
Olives and olive oil are sources of electrophilic fatty acid nitroalkenes
Extra virgin olive oil (EVOO) and olives, key sources of unsaturated fatty acids in the Mediterranean diet, provide health benefits to humans. Nitric oxide (âąNO) and nitrite (NO2-)-dependent reactions of unsaturated fatty acids yield electrophilic nitroalkene derivatives (NO 2-FA) that manifest salutary pleiotropic cell signaling responses in mammals. Herein, the endogenous presence of NO2-FA in both EVOO and fresh olives was demonstrated by mass spectrometry. The electrophilic nature of these species was affirmed by the detection of significant levels of protein cysteine adducts of nitro-oleic acid (NO2-OA-cysteine) in fresh olives, especially in the peel. Further nitration of EVOO by NO2- under acidic gastric digestive conditions revealed that human consumption of olive lipids will produce additional nitro-conjugated linoleic acid (NO2-cLA) and nitro-oleic acid (NO2-OA). The presence of free and protein-adducted NO2-FA in both mammalian and plant lipids further affirm a role for these species as signaling mediators. Since NO2-FA instigate adaptive anti-inflammatory gene expression and metabolic responses, these redox-derived metabolites may contribute to the cardiovascular benefits associated with the Mediterranean diet. © 2014 Fazzari et al
Structural basis for CRISPR RNA-guided DNA recognition by Cascade
The CRISPR (clustered regularly interspaced short palindromic repeats) immune system in prokaryotes uses small guide RNAs to neutralize invading viruses and plasmids. In Escherichia coli, immunity depends on a ribonucleoprotein complex called Cascade. Here we present the composition and low-resolution structure of Cascade and show how it recognizes double-stranded DNA (dsDNA) targets in a sequence-specific manner. Cascade is a 405-kDa complex comprising five functionally essential CRISPR-associated (Cas) proteins (CasA1B2C6D1E1) and a 61-nucleotide CRISPR RNA (crRNA) with 5âČ-hydroxyl and 2âČ,3âČ-cyclic phosphate termini. The crRNA guides Cascade to dsDNA target sequences by forming base pairs with the complementary DNA strand while displacing the noncomplementary strand to form an R-loop. Cascade recognizes target DNA without consuming ATP, which suggests that continuous invader DNA surveillance takes place without energy investment. The structure of Cascade shows an unusual seahorse shape that undergoes conformational changes when it binds target DNA.
Breakingtheice: A protocol for a randomised controlled trial of an internet-based intervention addressing amphetamine-type stimulant use
Background: The prevalence of amphetamine-type stimulant use is greater than that of opioids and cocaine combined. Currently, there are no approved pharmacotherapy treatments for amphetamine-type stimulant problems, but some face-to-face psychotherapies are of demonstrated effectiveness. However, most treatment services focus on alcohol or opioid disorders, have limited reach and may not appeal to users of amphetamine-type stimulants. Internet interventions have proven to be effective for some substance use problems but none has specifically targeted users of amphetamine-type stimulants. Design/method: The study will use a randomized controlled trial design to evaluate the effect of an internet intervention for amphetamine-type stimulant problems compared with a waitlist control group. The primary outcome will be assessed as amphetamine-type stimulant use (baseline, 3 and 6âmonths). Other outcomes measures will include âreadiness to changeâ, quality of life, psychological distress (K-10 score), days out of role, poly-drug use, help-seeking intention and help-seeking behavior. The intervention consists of three modules requiring an estimated total completion time of 90 minutes. The content of the modules was adapted from face-to-face clinical techniques based on cognitive behavior therapy and motivation enhancement. The target sample is 160 men and women aged 18 and over who have used amphetamine-type stimulants in the last 3âmonths. Discussion: To our knowledge this will be the first randomized controlled trial of an internet intervention specifically developed for users of amphetamine-type stimulants. If successful, the intervention will offer greater reach than conventional therapies and may engage clients who do not generally seek treatment from existing service providers
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