305,482 research outputs found
X-entanglement: the non-factorable spatio-temporal structure of biphoton correlation
No full textIn this work we turn our attention to the genuine quantum properties of PDC, and we demonstrate the hyperbolic
geometry underlying the spatio-temporal structure of the PDC entanglement and its non-factorability with
respect to space and time [1,2]. As for the macroscopic X-waves, the X-shape of the biphoton correlation is
imposed by the phase-matching mechanism governing the PDC process, and following this analogy we coined
the name of X-entanglement
[1] A. Gatti, E. Brambilla, L. Caspani, O. Jedrkiewicz, and L.A. Lugiato, Phys. Rev. Lett. 102, 223601 (2009) ;
e-print arXiv:0812.3533v1
[2] L. Caspani, E. Brambilla and A. Gatti, Tailoring the spatio-temporal structure of biphoton entanglement in
type I PDC , Phys. Rev A, 81, 033808 (2010
Counterpropagating frequency mixing with terahertz waves in diamond
No full textFrequency conversion by means of Kerr nonlinearity is one of the most common and exploited nonlinear optical processes in the UV, visible, IR, and mid-IR spectral regions. Here we show that wave mixing of an optical field and a terahertz wave can be achieved in diamond, resulting in the frequency conversion of the terahertz radiation either by sum-or difference-frequency generation. In the latter case, we show that this process is phase matched and most efficient in a counterpropagating geometry. (C) 2013 Optical Society of America</p
Storie scelte. Elementi e pratiche di didattica della storia
No full textUna introduzione alla didattica della storia che conduce a riscoprire la dimensione umanistica del sapere storico e fornisce esempi di pratiche didattiche innovativ
La città nel verde. Progetto per l'area ex Caffaro-Ideal Clima a Brescia
No full textPubblicazione di una tesi di laurea selezionata per partecipare al Premio Manter
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Dispelling the Myths Behind First-author Citation Counts
No full textWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
Small talk: microbial metabolites involved in the signaling from microbiota to brain
No full textThe wealth of biotransformational capabilities encoded in the microbiome expose the host to an array of bioactive xenobiotic products. Several of these metabolites participate in the communication between the gastrointestinal tract and the central nervous system and have potential to modulate central physiological and pathological processes. This biochemical interplay can occur through various direct and indirect mechanisms. These include binding to host receptors in the brain, stimulation of the vagus nerve in the gut, alteration of central neurotransmission, and modulation of neuroinflammation. Here, the potential for short chain fatty acids, bile acids, neurotransmitters and other bioactive products of the microbiome to participate in the gut-brain axis will be reviewed
SOSTENIBILITA' COME OTTIMIZZAZIONE DEL PROGETTO DI CONSERVAZIONE
No full textIn architecture, the sustainability paradigm is able to evaluate how the physical transformations can influence the natural and anthropical environment. That is why it is important to control these transformations overall.
With particular regards to new buildings, the monitoring can move from the technological resources, that can be apt from the constructive and environmental point of view, to the social and economical ones.
The same parameters used to define the environmental impact assessment for new buildings are employed to judge the sustainability in the conservation project of historical buildings.
Conservation is a sustainable approach, because is finalized to minimize the restoration and to maximize the level of knowledge about the construction.
According to the new given definition of conservation, the sustainability can be defined as optimization of the activities connected to safeguard and to restoration of Cultural Heritage.
Sustainability therefore is a process to balance conveniently resources and tasks: collection and organization of the data; management of the human and economical assets; valorisation and usability; use of the material resources (from the compatibility, reversibility and possible disposal); conception of structural and conservative solution that shall be controlled during the time. It is, also , important, to verify which barriers could be broken by the development of the optimization/sustainable process. The diffusion of the specific conservation culture that embraces the management of the cultural heritage might be the main one.
The present aims analyze, also by examples, how the above mentioned process could be applied into conservation project and the integration among “classical” procedures and rating systems
Author, publisher and bookseller : a tripartite synergy in Nigerian book industry
No full textThis work is about the roles of Author, Publisher and Bookseller in Book development in
Nigeria. The paper started by delving into the history of Book Publishing in Nigeria after
which it proceeded by defining who an author, a publisher, and a bookseller is and
expatiated on the indispensable roles of these key actors in Nigerian Book Industry and in
the emerging Information Society. Furthermore, the various constraints to book
development were identified while the paper advised on how the Book Industry can be
further promoted in Nigeria. However, the paper concluded and made recommendations
on how the Book sector can help in enhancing scholarship in the country
Metabolomics and the gut–brain axis
No full textIt is now well established that a multidimensional pan-kingdom communication network exists between the gut microbiota and the brain. This dialogue is bidirectional and involves multiple lines of communication. The metabolic output of the intestinal microbiota represents a major component of this crosstalk. Gut microbial metabolites can act locally on the enteric nervous system, and/or reach the central nervous system to elicit their effects. The metabolic activity of the gut microbiota and its resultant metabolites have an important role in normal brain function and have been shown to impact on the brain across the life-course, influencing neurodevelopmental, neuropsychiatric, and neurodegenerative disorders. The metabolites involved in the gut–brain axis span a range of chemical classes including short-chain fatty acids, bile acids, choline-related metabolites, and vitamins among others. Metabolomics is a systems biology approach that seeks to comprehensively measure a diverse range of metabolites in a biological sample, capturing the metabolome. Importantly, the metabolome contains not only molecules derived from host endogenous processes but also those derived from the microbiota, and their biochemical interactions with the host. As such, metabolomics provides an excellent tool for studying the biochemical component of the microbiota–gut–brain axis.</p
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