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Search Results: 1 - 10 of 137140 matches for " Leonardo V.;Carollo "
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Comparative profiles of Achyrocline alata (Kunth) DC. and A. satureioides (Lam.) DC., Asteraceae, applying HPLC-DAD-MS
Grassi-Zampieron, Rafaela;Fran?a, Leonardo V.;Carollo, Carlos A.;Vieira, Maria do Carmo;Oliveros-Bastidas, Alberto;Siqueira, Jo?o M. de;
Revista Brasileira de Farmacognosia , 2010, DOI: 10.1590/S0102-695X2010000400017
Abstract: a comparative analysis between the hydromethanolic extracts of achyrocline alata (kunth) dc. and a. satureioides (lam.) dc., asteraceae, was performed by the use of hplc-dad-ms. both plants were used without distinction and under the same indications in folk medicine in mato grosso do sul, brasil. while achyrocline alata ("jatei-ka-ha") is used in folk medicine of the brazilian state of mato grosso do sul, a. satureioides is predominantly used in other states. samples of both plants collected in different periods, 1996 and 2002, showed a very similar chemical profile. the results indicate that a alata could be used in phytotherapeutic preparations as substitue for a. satureioides, since they have similar chemical compositions of the polar extract.
Dynamics of Foraging and Recruitment Behavior in the Asian Subterranean Termite Coptotermes gestroi (Rhinotermitidae)
Alberto Arab,Yara carollo Blanco,Ana Maria Costa-Leonardo
Psyche , 2012, DOI: 10.1155/2012/806782
Abstract: The present study investigated the trail-following behavior of the subterranean termite Coptotermes gestroi (Wasmann Rhinotermitidae) under laboratory conditions. The results showed that workers were the first to initiate the exploration to the food source. When food was discovered they returned to the nest laying a trail for recruiting nestmates to the food source. In this situation, workers always traveled significantly faster when returning from the arenas. Both workers and soldiers were recruited to the food source; however, the soldier/worker proportion was higher during the first phase of the recruitment. When no food was available, the number of recruited nestmates and the speed on their way back to the nest were significantly lower. The results also showed that scout foragers always laid trail pheromones when entering into unknown territories, and that chemical signals found in the food could induce workers of C. gestroi to increase their travel speed. 1. Introduction The dynamics of the foraging and recruitment process in social insects has been investigated in many species within the Isoptera and the Hymenoptera. While many ants and bees also rely on optical cues, foraging in termites is organized predominantly by chemical signals, such as pheromone trails laid on the substrate for orientation and recruitment. The sternal gland is the only reported source of trail pheromone in termites. Secretions of this gland are considered to function in the recruitment of nestmates to source disturbance within the nest. Termites may also use trail-following pheromones to colonize new food sources [1, 2]. Termite trail-following pheromones are composed of one or few compounds. Up to date, only 9 compounds have been identified as trail pheromones in several termite species. For the termite families in which chemical trail pheromones have been reported, Rhinotermitidae, Termitidae, and Kalotermitidae seem to use mainly neocembrene A, (Z,Z,E)-dodeca-3,6,8-trien-1-ol, (Z)-dodec-3-en-1-ol, and (Z,Z)-dodeca-3,6-dien-1-ol [3–9]. Nasutitermes corniger uses in addition to these two compounds, trinervitatriene [8]; Mastotermitidae uses (E)-2,6,10-trimethyl-5,9-undecadien-1-ol and Termopsidae uses (E)-2,6,10-trimethyl-5,9-undecadien-1-ol, tricosane, and 4,6-dimethyldodecanal; whereas Glossotermes oculatus (Serritermitidae) uses nonecadienone for trail following [10, 11]. Termites also seem to use secretions of the sternal gland as both attractants and orientation signals in their foraging trails [12, 13], but the details of the chemical communication system used by
Berry's phase in Cavity QED: proposal for observing an effect of field quantization
A. Carollo,M. Franca Santos,V. Vedral
Physics , 2002, DOI: 10.1103/PhysRevA.67.063804
Abstract: Geometric phases are well known in classical electromagnetism and quantum mechanics since the early works of Pantcharatnam and Berry. Their origin relies on the geometric nature of state spaces and has been studied in many different systems such as spins, polarized light and atomic physics. Recent works have explored their application in interferometry and quantum computation. Earlier works suggest how to observe these phases in single quantum systems adiabatically driven by external classical devices or sources, where, by classical, we mean any system whose state does not change considerably during the interaction time: an intense magnetic field interacting with a spin 1/2, or a birefringent medium interacting with polarized light. Here we propose a feasible experiment to investigate quantum effects in these phases, arising when this classical source drives not a single quantum system, but two interacting ones. In particular, we show how to observe a signature of field quantization through a vacuum effect in Berry's phase. To do so, we describe the interaction of an atom and a quantized cavity mode altogether driven by an external quasi-classical field.
Wine Consumption in the Mediterranean Diet: Old Concepts in a New Sight  [PDF]
Caterina Carollo, Gregorio Caimi
Food and Nutrition Sciences (FNS) , 2012, DOI: 10.4236/fns.2012.312226
Abstract: The term “Mediterranean diet” is widely employed to indicate the typical diet of the Countries located on the Mediterranean sea coast. A growing body of scientific literature pointed out the healthy effects of this diet. In recent years we investigated about the protective effects of a regular and moderate wine consumption. As we know, alcoholic and non alcoholic wine constituents are responsible of different effects by means of molecular and cell mechanisms. Among the non alcoholic components, polyphenols (for example resveratrol and quercetin) were deeply investigated. The aim of this review is to underline the effects of a moderate and regular wine drinking in the context of the Mediterranean diet in light of the interactions between wine and important dietary factors such as olive oil, fruit and vegetables.
Metabolomics as a Potential Chemotaxonomical Tool: Application in the Genus Vernonia Schreb
Maria Elvira Poleti Martucci, Ric C. H. De Vos, Carlos Alexandre Carollo, Leonardo Gobbo-Neto
PLOS ONE , 2014, DOI: 10.1371/journal.pone.0093149
Abstract: The taxonomic classification of the genus Vernonia Schreb is complex and, as yet, unclear. We here report the use of untargeted metabolomics approaches, followed by multivariate analyses methods and a phytochemical characterization of ten Vernonia species. Metabolic fingerprints were obtained by accurate mass measurements and used to determine the phytochemical similarities and differences between species through multivariate analyses approaches. Principal component analysis based on the relative levels of 528 metabolites, indicated that the ten species could be clustered into four groups. Thereby, V. polyanthes was the only species with presence of flavones chrysoeriol-7-O-glycuronyl, acacetin-7-O-glycuronyl and sesquiterpenes lactones piptocarphin A and piptocarphin B, while glaucolide A was detected in both V. brasiliana and V. polyanthes, separating these species from the two other species of the Vernonanthura group. Species from the Lessingianthus group were unique in showing a positive response in the foam test, suggesting the presence of saponins, which could be confirmed by metabolite annotation. V. rufogrisea showed a great variety of sesquiterpene lactones, placing this species into a separate group. Species within the Chrysolaena group were unique in accumulating clovamide. Our results of LC-MS-based profiling combined with multivariate analyses suggest that metabolomics approaches, such as untargeted LC-MS, may be potentially used as a large-scale chemotaxonomical tool, in addition to classical morphological and cytotaxonomical approaches, in order to facilitate taxonomical classifications.
Vacuum induced Spin-1/2 Berry phase
I. Fuentes-Guridi,A. Carollo,S. Bose,V. Vedral
Physics , 2002, DOI: 10.1103/PhysRevLett.89.220404
Abstract: We calculate the Berry phase of a spin-1/2 particle in a magnetic field considering the quantum nature of the field. The phase reduces to the standard Berry phase in the semiclassical limit and eigenstate of the particle acquires a phase in the vacuum. We also show how to generate a vacuum induced Berry phase considering two quantized modes of the field which has a interesting physical interpretation.
El control de los agregados monetarios: lecciones y experiencias del caso venezolano reciente
Vera, Leonardo V.;
Economia e Sociedade , 2009, DOI: 10.1590/S0104-06182009000100005
Abstract: this work examines the difficulties and formidable challenges faced by monetary authorities to control the behavior of monetary aggregates in an open economy dependent of an exportable natural resource such as venezuela. the work not only introduces analytical arguments but also provides some empirical evidence that shows the several sources of endogeneity in the monetary base, the multiplier and other wider monetary aggregates in venezuela. though the central bank currently does not announce a clear strategy and target for the practice of monetary policy, we argue that the monetary authority has recently moved towards a strategy of targeting short-term interest rates. presumably, the use of the repo rate as a monetary policy instrument is tied to a final target of economic activity.
Grammaticalization: The development of some English modal auxiliaries
Véliz Campos,Leonardo;
Literatura y lingüística , 2007, DOI: 10.4067/S0716-58112007000100011
Abstract: this paper approaches the topic of grammaticalization from a diachronic perspective, with particular emphasis on the development of some english modal auxiliaries. the first part contextualizes the topic within the filed of cognitive linguistics; the second, deals with a brief description of lexical and grammatical items. the third part of the paper provides some crucial information on the history of grammaticalization. a final section outlines some of the mechanisms involved in the process of grammaticalization together with the analysis of some english modal auxiliaries and the importance of it in when studying and understanding english as a foreign language.
Corrective Feedback in Second Language Classrooms
Véliz C,Leonardo;
Literatura y lingüística , 2008, DOI: 10.4067/S0716-58112008000100016
Abstract: in this paper i attempt to analyse and survey the role of corrective feedback -more specifically recasts- in the interaction between teachers and l2 students in a classroom. thus, i explore the effects of recasts on students' self-correction in order to finally come to the conclusión whether or not students are able to no tice this type of underlying correction and, therefore, reformulate their ill-formed utterances. besides, i also undertake a comprehensive survey of the literature on the topic. two different groups of students from the english teaching trainig programme at universidad católica raúl silva henrríquez are studied. five students taking english courses at an intermedíate level and five taking advanced english courses. intermedíate and advanced students have been categorised on the basis of their number of english language courses they have taken. intermedíate students have taken four, whereas advanced have taken seven. in this paper the point at issue is whether harmful and ineffective or essential and rather effective, and whether recasts are noticeable for students to 'read between lines' and figure out the underlying correction. i take the stand that recasts are only effective when using them with advanced students as they are more cognitively advanced and, therefore, able to make inferences and interpret the implicit message to reformulate their mistakes.the results as well as the tests on the whole, clearly demónstrate that recasts as a corrective technique happen to be a bit more effective with advanced students than with intermedíate students, though the difference is not striking.
Hemosiderosis pulmonar
Leonardo Véjar M.
Revista chilena de pediatría , 1999,
Abstract:
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