Introducción. Las actinoporinas (AP) son proteínas formadoras de poro (PFP) que se aso - cian a membranas conduciendo a la muerte celular. Sticholysinas I y II (St, StI/II) se encuen- tran entre las ...AP más potentes descritas en la naturaleza. El objetivo del presente trabajo fue estudiar la influencia de la composición lipídica y dinámica de la membrana en la unión y formación de poros por StI/II y nigrelysina (Ngr), una nueva AP aquí descrita. Métodos. La unión y formación de poros se estudiaron mediante membranas modelo combinadas con espectroscopía de fluorescencia y microscopía. Resultados y discusión. St y Ngr se unen y permeabilizan preferencialmente membranas que contienen esfingomielina (SM) cuando se compara con fosfatidilcolina (PC), debido a la presencia, en SM, de la unidad de fosfocolina de PC más la unidad ceramida (Cer). StI reconoce a Cer y a gangliósidos, aunque en menor extensión. En términos de propiedades dinámicas, StI penetra preferencialmente membra- nas con elevada movilidad lateral y adecuado nivel de SM. StI permeabiliza más eficiente - mente membranas con esteroles además de SM. Los bordes de la coexistencia de dominios lipídicos no constituyen un factor determinante para su unión y actividad. La heterogeneidad molecular de las membranas, más allá de la presencia de dominios, favorece la actividad de AP. Conclusiones. Estos estudios explican la relevancia de SM, otros lípidos de base Cer y esteroles a la actividad de St, Ngr, y por extensión, a las AP. Desde una perspectiva dinámica, una fase altamente fluida y moderadamente enriquecida en SM y esteroles constituye una plataforma ideal para la formación de poros por AP.
L’obiettivo di questo articolo è mettere a fuoco due delle caratteristiche principali della mente: la capacità di formulare analogie creative, combinando e reinterpre- tando in schemi nuovi le ...informazioni che un soggetto ha a sua disposizione, e la capacità di far slittare i concetti in aree semantiche a ni. Il progetto Copycat consiste in un so ware, messo a punto dal gruppo di ricer- ca F.A.R.G. dell’Indiana University tra gli anni ’80 e ’90 del secolo scorso, che, partendo da alcune informazioni di base, prova a formulare analogie intelligenti per rispondere a problemi logici circoscritti. Nell’articolo che segue si presenterà un’analisi dettagliata del progetto Copycat e dei suoi antecedenti, so ermandosi su alcune intuizioni teoriche ancora utili e stimolanti di questo approccio rappre- sentazionalista alla struttura e alle dinamiche della mente.
COME MIGLIORARE IL PENSIERO CRITICO NELL’APPRENDIMENTO DELLA FISICA? UNA REVISIONE SISTEMATICA DELLA LETTERATURA Abstract Critical thinking skills are essential skills needed in the 21st century. ...Critical thinking skills can be trained in students through student-centered learning. Through a literature review, this research aims to determine learning models that can improve critical thinking skills in physics. Data collection was based on Scopus and Google Scholar database sources. This type of document comes from journal articles with the keywords «critical thinking», «learning models», and «physics learning» from the years (2011-2021). The literature review used procedures adapted from PRISMA. Documents published are based on predetermined content analysis criteria, including year of publication, author, article source, learning model, physics material topic, research subject, education level, and assessment. Inquiry learning and the higher-order thinking laboratory (HOT Lab) dominate the learning models used to improve critical thinking skills. The critical skills indicators used vary. Indicators of critical thinking skills. Self-regulated learning is rarely used in research instruments compared to other indicators of critical thinking skills. The instruments used are multiple-choice, essays, worksheets, and observation sheets. Research respondents at the university level are often used in studies of critical thinking skills. Fluid mechanics is a topic that is often used in research. This research contributes to improving students’ critical thinking skills through various recommended learning models. Research findings show that student-centered learning models can improve critical thinking skills.
This volume introduces a systematic approach to mathematical problems involved with thermodynamic fluids. The book is written for theoretical and applied mathematicians with an interest in ...compressible flow, capillarity theory, and control theory.
The results are reported of the experimental application of mechanical vapour compression (MVC) to the concentration of different liquid foods (apple juice, rectified grape must, tomato juice, orange ...juice, dealcoholized yeast). In order to promote MVC in the food industry, ENEL Holding, in collaboration with Enel Distribution, Stazione Sperimentale per I'Industria delle Conserve Alimentari (SSICA) and CESI, in 2001 developed a small transportable demonstration pilot plant, manufactured by FBR-Elpo, having a capacity of about 100 kg/h of evaporated water, which utilises an electric resistance heater for start and compensation of thermal dispersions. An analysis of the experimental data shows that, when products are highly concentrated, as a result of the more marked ebullioscopic increase and, above all, of the progressive fouling of the system, heat exchange becomes less efficient and thus the exchanger requires higher deltaT values; this involves more elevated compression ratios and, therefore, higher compression energy consumption. However, it is confirmed that, in all trials, compressor efficiency increases with increasing concentration, because compression ratio approximates the optimum value, i.e. 2
Sono riportati i risultati dell'applicazione sperimentale di compressione meccanica del vapore (CMV) nella concentrazione di diversi liquidi alimentari (succo di mela, mosto d'uva rettificato, succo di pomodoro, succo d'arancia, lievito dealcolizzato). Per promuovere la CMV nel settore alimentare, ENEL Holding, in collaborazione con ENEL Distribuzione, Stazione Sperimentale per l'Industria delle Conserve Alimentari (SSICA) e CESI, hanno realizzato nel 2001 un piccolo impianto pilota dimostrativo e trasportabile a CMV, costruito da FBR-Elpo, da circa 100 kg/h d'acqua evaporata, che per l'avviamento e la compressione delle dispersioni termiche utilizza un riscaldatore elettrico a resistenza. Dall'analisi dei dati sperimentali si evince che, quando i prodotti sono molto concentrati, a causa dell'innalzamento ebullioscopico piu' marcato e, soprattutto, del progressivo "sporcamento" del sistema, lo scambio termico risulta meno efficiente, per cui sono necessarie allo scambiatore deltaT piu' elevate, il che significa rapporti di compressione piu' alti e, quindi, maggiori consumi energetici di compressione. Si conferma, peraltro, in tutte le prove condotte, che l'efficienza del compressore cresce all'aumentare della concentrazione perche' il rapporto di compressione si avvicina al valore ottimale di 2
This book aims to bridge the gap between practising mathematicians and the practitioners of turbulence theory. It presents the mathematical theory of turbulence to engineers and physicists, and the ...physical theory of turbulence to mathematicians. The book is the result of many years of research by the authors to analyse turbulence using Sobolev spaces and functional analysis. In this way the authors have recovered parts of the conventional theory of turbulence, deriving rigorously from the Navier–Stokes equations what had been arrived at earlier by phenomenological arguments. The mathematical technicalities are kept to a minimum within the book, enabling the language to be at a level understood by a broad audience. Each chapter is accompanied by appendices giving full details of the mathematical proofs and subtleties. This unique presentation should ensure a volume of interest to mathematicians, engineers and physicists.