1,721,227 research outputs found
Functional role of the third cytoplasmic loop in muscarinic receptor dimerization.
No full textBy means of the expression of two chimeric receptors, alpha2/m3 and m3/alpha2, in which the carboxyl-terminal receptor portions, containing transmembrane (TM) domains VI and VII, were exchanged between the alpha2C adrenergic and the m3 muscarinic receptor, Maggio et al. (Maggio, R., Vogel, Z., and Wess, J. (1993) Proc. Natl. Acad. Sci. U. S. A. 90, 3103-31073) demonstrated that G protein-linked receptors are able to interact functionally with each other at the molecular level to form (hetero)dimers. In the present study we tested the hypothesis that interaction between receptors might depend on the presence of a long third intracellular (i3) loop and that shortening this loop could impair the capability of receptors to form dimers. To address this question, we initially created short chimeric alpha2 adrenergic/m3 muscarinic receptors in which 196 amino acids were deleted from the i3 loop (alpha2/m3-short and m3/alpha2-short). Although co-transfection of alpha2/m3 and m3/alpha2 resulted in the appearance of specific binding, the co-expression of the two short constructs (alpha2/m3-short and m3/alpha2-short), either together or in combination, respectively, with m3/alpha2 and alpha2/m3 did not result in any detectable binding activity. In another set of experiments, a mutant m3 receptor, m3/m2(16aa), containing 16 amino acids of the m2 receptor sequence at the amino terminus of the third cytoplasmic loop, which was capable of binding muscarinic ligands but was virtually unable to stimulate phosphatidylinositol hydrolysis, was also mutated in the i3 loop, resulting in the m3/m2(16aa)-short receptor. Although co-transfection of m3/m2(16aa) with a truncated form of the m3 receptor (m3-trunc, containing an in frame stop codon after amino acid codon 272 of the rat m3 sequence) resulted in a considerable carbachol-stimulated phosphatidylinositol breakdown, the co-transfection of m3/m2(16aa)-short with the truncated form of the m3 receptor did not result in any recovery of the functional activity. Thus, these data suggest that intermolecular interaction between muscarinic receptors, involving the exchange of amino-terminal (containing TM domains I-V) and carboxyl-terminal (containing TM domains VI and VII) receptor fragments depends on the presence of a long i3 loop. One may speculate that when alternative forms of receptors with a different length of the i3 loop exist, they could have a different propensity to dimerize
Emotions Course: l’esperienza di un intervento educativo per la promozione della competenza socio-emotiva nella scuola dell’infanzia
No full textL’esperienza qui presentata s’inserisce nell’ambito degli interventi condotti secondo un approccio evidencebased nella scuola dell’infanzia e riguarda la realizzazione dell’Emotions Course (EC; Di Maggio, Zappulla e Izard, 2014), un percorso educativo finalizzato alla promozione delle abilità socio-emotive in età prescolare. Il programma è stato elaborato facendo riferimento ai fondamenti e agli sviluppi della teoria differenziale delle emozioni, i cui principi sono stati «tradotti» in modo da formare le basi concettuali ed empiriche dell’intervento, articolato nell’ottica della prevenzione primaria e secondaria (Izard, 2002, 2009). In particolare, l’EC è stato applicato al fine di migliorare: – la comprensione delle emozioni primarie (gioia, tristezza, rabbia, paura), intesa in età prescolare come la conoscenza da parte dei bambini sia delle diverse modalità verbali e non verbali di espressione emotiva sia delle cause esterne (gli antecedenti situazionali) e interne (per esempio, i desideri) che possono suscitare le diverse emozioni; – la regolazione emotiva, ossia la capacità dei bambini di esercitare un controllo sull’espressione delle emozioni e sui vissuti emotivi in modo da potere utilizzare costruttivamente la componente motivazionale delle emozioni e mettere in atto risposte cognitive e comportamentali adeguate alle opportunità e alle richieste dell’ambiente; – la competenza sociale dei bambini, la capacità, cioè, di stabilire e mantenere relazioni positive con i pari, di lavorare insieme, di affrontare e risolvere eventuali problemi e conflitti. Hanno preso parte allo studio 143 bambini (73 maschi e 70 femmine) di 3-5 anni (età media = 4.4 anni, ds = .74), inseriti nelle classi di due scuole dell’infanzia di una città del sud d’Italia
Le Special Purpose Acquisition Companies come strumento alternativo di raccolta di capitale
No full textA Special Purpose Acquisition Company (SPAC) is a pooled investment vehicle that allows a stock market equityholder to take part in a private equity buyout transaction. In this paper, we highlight potential advantages and drawbacks of such an instrument in a country characterized by poor legal investor protection, of which Italy may be an ideal archetype
Repurposing the mucolytic cough suppressant and TMPRSS2 protease inhibitor bromhexine for the prevention and management of SARS-CoV-2 infection
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Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe 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
G protein-coupled receptor oligomerization provides the framework for signal discrimination.
No full textThe idea that G protein-coupled receptors (GPCRs) may undergo homo- or hetero-oligomerization, although highly controversial up to a few years ago, has recently gained wide acceptance. The recognition that GPCRs may exhibit either dimeric or oligomeric structures is based upon a large body of biochemical and biophysical evidence. While much effort has been spent to demonstrate the mechanism(s) by which GPCRs interact with each other, the physiological relevance of this phenomenon remains rather elusive. GPCR oligomerization has been proposed to play a role in receptor ontogeny by either chaperoning protein folding or controlling trafficking to the cell surface. However, the acquisition of these roles does not rule out the possibility that oligomeric receptors may have additional functions, once they are brought to the cell surface. Herein, we propose that protein-protein as well as protein-lipid interactions may provide the structural basis for organizing distinct cell compartments along the plasma membrane where different extracellular signals may be perceived and discriminated
Apomorphine continuous stimulation in Parkinson's disease: Receptor desensitization as a possible mechanism of reduced motor response
No full textLa valutazione del temperamento infantile: osservazioni dirette e indirette delle espressioni emotive nel primo anno di vita
No full textLo studio si propone di esaminare le differenze individuali nell’espressione delle emozioni di gioia,
rabbia, interesse e paura e nel livello di attività di bambini nel primo anno di vita, utilizzando un approccio
multi-metodo basato sull’utilizzo di uno strumento di osservazione diretta, la Lab-TAB (Goldsmith e
Rothbart, 1999), e uno strumento di osservazione indiretta, il questionario IBQ-R (Montirosso, Cozzi,
Putnam, Gartstein e Borgatti, 2011). I dati delle osservazioni dirette sono stati rilevati attraverso due
diversi sistemi di codifica: molecolare e globale. Obiettivo dello studio è anche di verificare se i risultati
ottenuti con i due sistemi di codifica delle osservazioni convergano tra loro e con quelli ottenuti dalle
valutazioni materne fornite tramite la compilazione del questionario. L’analisi dei cluster effettuata sui
dati rilevati tramite la codifica molecolare delle osservazioni ha permesso di identificare cinque profili
temperamentali che corrispondono solo in parte a quelli emersi dall’analisi della codifica globale delle
osservazioni e dei questionari. I dati mostrano, inoltre, come i punteggi della Lab-TAB ottenuti con i due
sistemi di codifica – molecolare e globale – convergano tra loro, ma non correlino significativamente
con i punteggi delle stesse dimensioni del temperamento rilevate tramite l’IBQ-R.The study is aimed to examine individual differences in the expression of emotions
of joy, anger, interest, fear, and in the level of activity of children in the first year of life, by
means of a multi-method approach based on the use of an instrument for direct observation, the
Lab-TAB (Goldsmith and Rothbart, 1999), and of an instrument for indirect observation, the questionnaire
IBQ-R (Montirosso et al., 2011). Data from direct observations were coded through two
different coding systems: molecular and global. The study was also aimed to verify whether the
results obtained with the two coding systems converged with each other and with those obtained
with the questionnaire. The cluster analysis performed on data collected through the molecular
coding allowed to identify five temperamental profiles that match only partially to those that
emerged from the global coding of the observations and questionnaires. The data also show that
the Lab-TAB scores obtained with the two coding systems – global and molecular – converged
with each other, but did not correlate significantly with the scores of the same dimensions of temperament
detected by the IBQ-R
Lesser kestrel diet and agricultural intensification in the Mediterranean: An unexpected win-win solution?
No full textFarmland bird species have suffered dramatic declines in recent decades, especially in Mediterranean areas. The
intensification of agricultural practices has led to reduced invertebrate prey, which represent the bulk of the diet
of many farmland birds. In this study, we investigated the spatial and temporal variation in the diet of the lesser
kestrel (Falco naumanni) during the breeding season, monitored over a five-year period between 2006 and 2013
in the Gela Plain (Sicily). Our aim was to understand whether, and to what extent, farming practices affected the
reproductive outputs of this predominantly insectivore bird in order to find a profitable compromise between
conservation of farmland birds and farming practices. During our study, lesser kestrel diet varied among
farmland habitats, in terms of ingested biomass, prey items/pellet and diet breadth. This has reflected in the
reproductive output because colonies characterised by a higher ingested biomass fledged more chicks than the
others. The artichoke and grassland fields were found to provide the most beneficial dietary parameters.
Unexpectedly, the intensive and high-profit artichoke farming might turn out to be suitable for lesser kestrels.
Artichoke fields are chiefly used when abandoned after harvest, providing high prey availability and accessibility
for kestrels during the brood raising stage of their breeding season. A mosaic of grassland and artichoke fields
can thus be recommended for Mediterranean agricultural areas of the Natura2000 network, in which some intensive farming and lesser kestrels can coexist, if adequately framed in a friendly-to-wildlife agriculture policy. Such a potential optimal trade-off between avian population persistence and economic sustainability for farmers we have found, should be planned in alternative management of agro-ecosystems, enhancing the functioning of trophic chains. For our study area, we suggest at least farmers be: i) informed on the role of predators as biological agents for pest control; ii) granted to reduce the high level of chemicals currently used during cultivation
in favour of organic farming; and iii) granted to maintain the artichoke fields until June, following
completion of the harvest
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