6,887 research outputs found
Peptide-based foldamers: new photo-controlled devices towards opto-electronic and mechanical applications
No full textI
An ECD investigation aiming at assessing the critical main-chain length for peptide helix formation in water solution is reported. To this goal, it was synthesized by a solution step-by-step protocol a complete series of N-terminally acetylated, C-terminally methoxylated oligopeptides, characterized only by alternating Aib and Ala residues, from the di- to the nonamer stage. All of these compounds were investigated by ECD in the far-UV region in water solution as a function of chemical structure, the presence/absence of the ester moiety at the C-terminus and temperature. The critical main-chain lengths for 310- and α-helices, although still formed to a partial extent, in aqueous solution are six and eight residues, respectively.
II
A whole series of AuNps was synthesized from mercaptopropionic derivatives of alternating Aib/Ala peptide series. Our studies established the occurrence of chiroptical properties in peptide-coated 2 nm diameter gold nanoparticles. The peptides induce a chiral effect onto the plasmon resonance band detectable via ECD. Such a behavior appears to be strongly influenced by the secondary structure assumed by the coating peptides.
III
The water solubility displayed by alternating Aib/Ala peptide series was investigated. The evidences of the formation of self-assembled structures in water, likewise responsible for the unexpected solubility properties, are presented. These peptide aggregates are spherical, with diameters up to 100 nm. They can also incorporate other molecular structures of relevant size, such as Au nanoparticles. Such systems may widen the number of applications currently accessible to self-assembled aggregates in the fields of biomedicine and materials science.
IV
Two new Ca-tetrasubstituted a-amino acids bearing two identical azobenzene-derived side chains have been synthesized. Photo-reversible isomerization process was detected. Intermediate chiral species are generated during the isomerization process driven by iii
light. Diastereomers where generated when a chiral protein amino acid was inserted.
The conjugation of one of the bis(azobenzene)-derived amino acids with different metal
nanoparticles allowed the isomerization process to be detected even in solid state.
Furthermore, the Au-derived nanoparticles exhibit a magnetic susceptibility dependence
on the light-driven isomerization state that can be simply detected by 1H-NMR
spectroscopy. Based on this behavior, these amino acids are of relevant potential for the
development of a novel class of materials.
V
A series of Ferrocene and Pyrene labelled helical peptides containing one or more 4-
amino-1,2-dithiolane-4-carboxylic acid (Adt) residues have been synthetized. Such
peptides have been prepared to be employed in the formation of SAMs over gold
surfaces (by means of linkage with the dithiolane Adt side chains) for electrochemical
applications. In particular, the peptides have been designed for ensuring: (i) an highrigidity
of the peptide scaffold and (ii) a parallel disposition of the peptide axle respect
the metal surface. Conformational characterizations and CV tests on a Ferrocene
binding 6-mer are presented. Preliminary experiment on the photo-current generation
property has also been performed
MENTAL WORKLOAD
No full textThis chapter begins with an assessment of the nature and characteristics of mental workload and how people have defined it over the years. It looks at the major techniques, their relative advantages and disadvantages and how they are enacted in practical circumstances in the many operational domains to which they can apply. The chapter examines approaches including some that have fallen out of favor and others which, at the present time represent only candidate proposals which offer a degree of applicational promise. It looks also looks at workload and its assessment in the broader context of humans and their interaction with developing and evolving forms of technology. The chapter considers where workload stands in relation to pressing issues such as human teaming with ever-more autonomous systems. Human cognitive workload assessment might be rather obviated by developments while, interestingly, assessment of computer “cognitive” load may actually burgeon in importance
Ritorno al Pireo. Alcune riflessioni sull'organizzazione urbana e sulla cronologia dell'impianto
No full textIn this paper the author discusses the town plan of Piraeus to shed further light on some aspects he already examined in a previous article (Longo 2008). Starting from the most recent archaeological data that were overlooked in some recent studies, and the literary and epigraphic documentation, the author attempts to capture the essential elements informing the development plan of Hippodamus of Miletus, viz., functionality and the likely pre-existence of the main street axes; the characteristics of the urban grid; a clear demarcation of public and private spaces; and the issue of the location of the two agorai mentioned in literary sources.
In questo contributo l’Autore riprende la discussione sull’urbanistica del Pireo chiarendo e precisando aspetti in parte già affrontati in un precedente articolo (Longo 2008). Partendo dai dati archeologici più recenti, poco valorizzati in alcune sintesi di questi ultimi anni, e dalla documentazione letteraria ed epigrafica, l’Autore cerca di cogliere gli elementi essenziali che sono alla base del progetto urbanistico di Ippodamo di Mileto: funzionalità e probabile preesistenza degli assi viari principali; caratteristiche della griglia urbana; netta delimitazione degli spazi pubblici e privati; cronologia dell’impianto; problema della localizzazione delle due agorai menzionate nelle fonti letterarie
The Author and Authorship in the Internet Society. New Perspectives for Scientific Communication
No full textThe Internet is the most recent and relevant innovation in the field of
media communication, as well as the medium that reproduces most of the characteristics
of global society. In trying to describe contemporary society, we cannot
neglect the social implication of the web. Our assumption is that the evolution of
the Internet has led to problematic effects on the relevance of concepts such as
individuality, author, authorship and copyright, as commonly used up till now.
The first part of the article focuses on individuality as a means to describe individual
actors and social structures in the first modernity, paying particular attention
to the idea of the author as an individual in the field of intellectual products.
New communication forms online make the connection between the individuality
of the author and the text weaker and less recognizable. The second part develops
the theme of scientific knowledge in contemporary society, with regard to scholarly
authorship. The Internet has produced deep transformations in scholarly
publications. Technical and structural characteristics of the Internet suggest possibilities
for a reorganization of the scientific system towards the replacement of
authorship and reputation with innovative mechanisms of information processing
and selection
A COMÉDIA DAS VAIDADES: MARXISMO, OLIGARQUIAS POLÍTICAS E COLETIVIZAÇÃO HISTÉRICA DO GÉNDERISMO
No full textGender ideology emerges as the next phase of the more mature relativism that in turn
found its roots in post-Marxism and structuralism from Gilles Deleuze to Michel Foucault, but which
had already recovered wide openness in the analytical philosophy of Jules Viullemin and in the Marx ian existentialism of Jean-Paul Sartre. The cult of the body as absolute self and the search for an
overlapping of culture on nature, of civilization on civilization, outline in genderism a propensity for
colonization of the human person, led to confuse the protection of individual rights and the protec tion of fundamental freedoms as a particular guarantee of an even axiological choice which, from
being an ideological expression of a sexual orientation, leads solely to the categorized, destructive
omesessualization of God’s creative plan precisely because it stands to be and become not a personal
choice, but politically and ideologically personalizing, so as to change the sense of reality and creation,
GIANFRANCO LONGO
Universitá Di Bari, Italia
[email protected]
Received: 07 Jan 2022
Accepted: 17 Mar 2022
Published: 20 Abr 2022
Corresponding author:
Journal of Teleological Science, v. 2, 2022, eISSN 2763-6577
© Telos Publicações e Serviços Ltda, Rio de Janeiro, Brasil
e00-2
of words and things to the point of proposing collectivization, highlighting in this hysterical and
obsessive characters, especially when a pedagogical use is proposed or no less if they are identified as
characters of university training and research courses
REL22 Reinventing Energy Landscapes
No full textREL22 was an international summer school program launched by the Institute of Landscape Architecture of RWTH Aachen University (Prof. Frank Lohrberg, Silvia Beretta) together with the Master’s Programme in „Landscape Architecture and Landscape Heritage“ of Politecnico di Milano (Prof. Antonio Longo) andthe Master’s Programme in “Landscape Architecture” of TU Delft (Prof. Laura Cipriani). The aim was to formulate visions for the landscape transformation of the Rhenish Lignite District, the largest open-cast lignite mining area in Europe, located in the German region of North Rhine Westphalia
Interações tróficas em ambientes recifais ao longo de diferentes escalas espaciais
No full textTese (doutorado) - Universidade Federal de Santa Catarina, Centro de Ciências Biológicas, Programa de Pós-Graduação em Ecologia, Florianópolis, 2015.Interações tróficas são fundamentais para a estrutura e funcionamento de ecossistemas, alterando padrões de densidade e biomassa de espécies de diferentes níveis tróficos. Atividades humanas podem afetar negativamente a estrutura e intensidade dessas interações, causando mudanças drásticas nos ecossistemas. Os ambientes recifais, por exemplo, têm sofrido uma variedade de impactos antrópicos (e.g., sobrepesca, poluição), levando à perda de diversidade e processos ecossistêmicos críticos, sobretudo aqueles mediados por interações tróficas. Por exemplo, quando peixes herbívoros e ouriços foram experimentalmente removidos (cenário de sobrepesca) de recifes de coral, macroalgas rapidamente dominaram o recife. Nesses ambientes, a pressão alimentar dos peixes recifais sobre a comunidade bentônica é um bom modelo de interação trófica já que tem uma importância fundamental na estruturação das comunidades bentônicas. A intensidade e composição de interações tróficas podem ser influenciadas por múltiplos fatores ao longo de diferentes escalas espaciais, com consequências importantes para o funcionamento dos ecossistemas. Por exemplo: na escala do centímetro, a qualidade nutricional de uma presa ou suas defesas químicas moldam a identidade de seus predadores e intensidade de predação; na escala do habitat (centenas de metros), diferentes níveis de tolerância à condições abióticas extremas podem resultar em refúgios contra predação; em largas escalas espaciais (centenas de quilômetros), a temperatura pode interferir na demanada metabólica do predador, moldando suas interações tróficas; em escala latitudinal, esses fatores ecológicos se combinam a fatores biogeográficos, como diferentes composições taxonômicas. Esta tese apresenta diferentes abordagens sobre interações tróficas desde a escala do centímetro até a escala latitudinal, em quatro capítulos: (1) ?Can seaweed-coral competition make seaweeds more palatable??, que aborda questões de competição direta entre corais e macroalgas e sua relação com herbivoria; (2) ?Between-habitat variation in benthic communities, reef fish assemblage and feeding pressure at the only atoll in South Atlantic: Rocas atoll, NE Brazil?, que avalia padrões das comunidades e processos ecológicos relacionados à sua estruturação emhabitats com diferentes condições abióticas; (3) ?Herbivory drives large-scale spatial variation in reef fish trophic interactions?, que explora a intensidade e composição da pressão alimentar dos peixes recifais sobre as comunidades bentônicas, identificando espécies-chave para esses ecossistemas; e (4) ?Latitudinal gradients in reef fish trophic interactions on the benthos?, que investiga a variação latitudinal (34oN?27oS) da intensidade e composição das interações tróficas dos peixes sobre o bentos no Oceano Atlântico Ocidental, e sua relação com fatores ambientais (e.g., temperatura) e contexto biogeográfico (e.g., regiões biogeográficas). Observou-se que: (1) na escala do centímetro, a competição com corais pode tornar a alga mais susceptível à herbivoria; (2) na escala do habitat, a sinergia entre fatores abióticos e interações tróficas é determinante na estruturação de comunidades recifais (peixes e bentos); (3) em larga escala espacial, a contribuição desproporcional de alguns grupos, indicam que o funcionamento dos ambientes recifais é variável de acordo com condições locais específicas (e.g., temperatura); e (4) em escala latitudinal, observou-se que embora recifes compartilhem os mesmos grupos funcionais, a identidade das espécies nesses grupos varia de acordo com o contexto biogeográfico. Esses múltiplos fatores ao longo de diferentes escalas espaciais demonstram a complexidade das interações tróficas e indicam abordagens possíveis de aplicação em conservação de processos críticos mediados por essas interações.Abstract : Trophic interactions are critical to the structure and functioning of ecosystems, altering density and biomass patterns of species across different trophic levels. Human activities have been negatively impacting these interactions, causing drastic changes in ecosystems. Reef habitats, for instance, have suffered a variety of human-related impacts (e.g, overfishing, pollution) leading to loss of biodiversity and critical ecosystem processes, particularly those mediated by trophic interactions. For example, when herbivorous fish and sea urchins were experimentally excluded from coral reefs (overfishing scenario) seaweeds rapidly overgrew corals. In these habitats, reef fish feeding pressure on the benthos is a good metric of trophic interaction because it is critically important to the structure of benthic communities. The intensity and composition of trophic interactions can be influenced by multiple factors across different spatial scales and have important consequences to ecosystem functioning. For example: at the scale of centimeters, prey nutritional quality or chemical defenses can shape the identity of predators and predation intensity; at the habitat scale (hundreds of meters), different tolerance levels to harsh abiotic conditions can result in predation refugees; at large spatial scales (hundreds of kilometers), temperature can interfere in the predator?s metabolic demand and thus influencing its trophic interactions; at latitudinal scales (thousands of kilometers), these ecological factors meet biogeography, for example with different taxonomic composition. This thesis presents different approaches on trophic interactions in reef systems from the centimeter to the latitudinal scales, along four chapters: (1) ?Can seaweed-coral competition make seaweeds more palatable??, encompassing direct coral-seaweed competition and its effect on herbivory by sea urchins; (2) ?Between-habitat variation in benthic communities, reef fish assemblage and feeding pressure at the only atoll in South Atlantic: Rocas atoll, NE Brazil?, on patterns in reef fish and benthic assemblages and ecological processes associated to its structure in habitats with different abiotic conditions; (3) ?Herbivory drives large-scale spatial variation in reef fish trophic interactions?, exploring the intensity and composition of reef fish feeding pressure on the benthosand identifying key groups to the studied ecosystems; and (4) ?Latitudinal gradients in reef fish trophic interactions on the benthos?, exploring the latitudinal variation (34oN?27oS) in the intensity and composition of reef fish feeding pressure on the benthos in the Western Atlantic Ocean, and its relation to environmental factos (e.g., temperature) and biogeographic context (e.g., biogeographic regions). The main outcomes are: (1) at the scale of centimeters, competition with corals can enhance seaweed?s susceptibility to herbivory by sea urchins; (2) at the habitat scale, the synergy between abiotic conditions and trophic interactions is critical to structure reef communities (fish and benthos); (3) at large spatial scales, the disproportional contribution of some groups indicate that the functioning of the reefs are variable and dependent on specific local conditions (e.g., temperature). And (4) at the latitudinal scale, it was observed that although reefs in different regions share the same functional groups, species within these groups vary according to the biogeographic context. These multiple factors across different spatial scales demonstrate the complexity of trophic interactions and indicate potential approaches to be applied in the conservation of critical processes they mediate
Introduction to IG-KDD
No full textSummary of the activities of the Interest Group on Knoledge Discovery in databases which the author coordinate
All’origine della nozione kantiana di “idea”: il confronto con Jakob Brucker
No full textKant’s knowledge of Plato was mostly
indirect and derived from various sources. One of
these was Johann Jakob Brucker’s Historia critica
philosophiae, which focuses on the Platonic doctrine
of ideas. By comparing Brucker’s work with Kant’s
section Von den Ideen überhaupt, it is possible to reconstruct
the context within which the Kantian notion
of “idea” emerges. In constrast to Brucker,
Kant denies that “ideas” are mere mental abstractions,
stating the notorious hermeneutical claim that
it is possible to understand an author better than the
author itself. The present paper aims to assess
Kant’s debt towards Brucker by identifying analogies
and diversities between the two German thinkers
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