Variability and motion of the Brazil-Malvinas front

The temporal evolution of the thermal field associated with frontal motions in the South Western Atlantic is studied. The analysis is based on data collected with an array of inverted echo sounders (IES) deployed during the Confluence Program (1988-1990) at the Brazil/Malvinas Confluence. The travel time series obtained with the IES are scaled to mean temperatures of the upper 500 m (Tsoo) of the ocean and series of T500 horizontal distributions are constructed. A description of the evolution of the thermal field, emphasizing the frontal motions and some mesoscaie features, is presented. Three well-defined northward penetrations of the Malvinas current with fairly variable periods of permanence (15-60 days) and mean frontal motion velocities of 0.2 m/s are observed. Cross-correlation of the T500 time series analysis leads to a plausible explanation of some features of the observed variability. Comparison with previous results in the area indicate a marked interannual variability and sources of variability are discussed.Se estudia la evolución temporal del campo de isotermas asociados con movimientos frontales en el océano Atlántico Sudoccidental. El análisis está basado en datos obtenidos de ecosondas invertidos (IES) fondeados durante la ejecución del Programa Confluencia (1988-1990) en la confluencia de las corrientes de Malvinas y Brasil. Las series de tiempo obtenidas con los IES fueron estandarizados con las temperaturas medias de los primeros 500 m (T500) del océano y de esta forma se obtuvo la distribución horizontal de T500. Se presenta una descripción de la evolución del campo térmico en relación con los movimientos frontales y las características de mesoescala de esa zona. Se observaron tres penetraciones bien definidas de la corriente de Malvinas con períodos variables de permanencia (15 -60 días) y velocidades del frente de 0.2 m/s. Del análisis de la correlación cruzada de la serie de T500 se obtiene una posible explicación de la variabilidad observada. La comparación con resultados previos indican una variabilidad interanual. Se discuten las fuentes de variabilidad.Material digitalizado en SEDICI gracias a la colaboración de la Facultad de Ciencias Astronómicas y Geofísicas (UNLP).Asociación Argentina de Geofísicos y Geodesta

Liquid and vapour phase of lavandin (Lavandula × intermedia) essential oil: chemical composition and antimicrobial activity

Essential oils from Lavandula genus and the obtained hybrids are widely used for different purposes such as perfume production in the cosmetic field and for its biological properties. This is the first study on the liquid and vapour phase of Lavandula × intermedia “Grosso” essential oil grown in the Lazio Region, Italy, investigated using headspace coupled to gas chromatography and mass spectrometry (HS-GC/MS). The results showed the most abundant components were linalool and linalyl acetate, followed by 1,8-cineole and terpinen-4-ol, while lavandulyl acetate and borneol were identified as minor compounds, maintaining the same proportion in both the liquid and vapour phase. Furthermore, we tested lavandin liquid and vapour phase essential oil on gram-negative bacteria (Escherichia coli, Acinetobacter bohemicus, and Pseudomonas fluorescens) and gram-positive bacteria (Bacillus cereus and Kocuria marina)

Chemical investigation of a biologically active schinus molle L. leaf extract

The pepper tree Schinus molle L. is an evergreen ornamental plant belonging to the Anacardiaceae family, native to South America and widespread throughout the world. It has biological activities and is used in folk medicine. This paper aims to contribute to a deeper knowledge of its chemical composition and biological properties. S. molle leaf extracts were obtained by sequential extraction with solvents of different polarities and subsequently tested on the HL-60 human leukaemia cell line to define a possible cytotoxic activity. Among the investigated extracts, the petroleum ether extract revealed a high cytotoxic activity, and its chemical composition was further investigated. By a silica column chromatography, eight fractions were obtained, and their compositions were determined by GC-MS analysis. Compounds and relative abundance differed widely among the fractions; sesquiterpenes resulted the main component and alcoholic sesquiterpenes the most abundant

Effect of gaseous ozone treatment on the aroma and clove rot by Fusarium proliferatum during garlic postharvest storage

It is known that garlic bulbs preserved with traditional methods undergo considerable losses, ranging from 25 to 40%. A frequent cause of these losses is associated with the development of pathogenic fungi, such as those of the genus Fusarium. The effect of ozone on post-harvest garlic bulbs was evaluated. Garlic cloves inoculated with Fusarium proliferatum F21 and F22 strains, were exposed to a continuous gaseous ozone flow (2.14 μg m−3), during 4 days, 20 h a day. After ozone-treatment, the garlic samples were moved at 22 °C to mimic retail conditions (shelf life). The changes in several quality parameters such as fungal decay and aroma were evaluated on garlic samples, as whole bulbs, cloves with and without tunic, through a sensorial descriptive test, SPME analysis in GC/MS and microbiological approaches. The data collected showed that ozone treatment did not affect the aromatic profile of garlic. A significant detrimental effect of ozone treatment on garlic decay was observed. Our results encourage the use of gaseous ozone treatment for containing garlic fungal decay during its storage

Caratterizzazione chimica quali-quantitativa della fase vapore degli oli essenziali

Gli oli essenziali sono prodotti naturali estratti da piante che generalmente presentano una composizione chimica piuttosto complessa. Si tratta di miscele ricche di composti volatili e termolabili come monoterpeni, sesquiterpeni e loro derivati ossigenati. La gascromatografia accoppiata alla spettrometria di massa è ampiamente utilizzata come tecnica analitica di separazione per l'identificazione e la quantificazione dei costituenti volatili della miscela chimica. La tecnica dello spazio di testa (HS) accoppiata al sistema cromatografico viene applicata come metodo di estrazione della fase vapore. Il campione, posto in una fiala chiusa viene riscaldato ad una temperatura tale da favorire il passaggio dei composti nella fase vapore. Tramite l’utilizzo di un gas inerte (He), avviene l’estrazione di tali componenti che verranno convogliati al gas cromatografo mediante l’utilizzo di una transfer-line. Si tratta di una tecnica estrattiva facilmente applicabile e particolarmente efficace soprattutto quando i composti volatili devono essere separati da una matrice liquida prima dell'analisi gas cromatografica evitando così una serie di problematiche legate all' uso dei solventi di estrazione

Variability and motion of the Brazil-Malvinas front

The temporal evolution of the thermal field associated with frontal motions in the South Western Atlantic is studied. The analysis is based on data collected with an array of inverted echo sounders (IES) deployed during the Confluence Program (1988-1990) at the Brazil/Malvinas Confluence. The travel time series obtained with the IES are scaled to mean temperatures of the upper 500 m (Tsoo) of the ocean and series of T500 horizontal distributions are constructed. A description of the evolution of the thermal field, emphasizing the frontal motions and some mesoscaie features, is presented. Three well-defined northward penetrations of the Malvinas current with fairly variable periods of permanence (15-60 days) and mean frontal motion velocities of 0.2 m/s are observed. Cross-correlation of the T500 time series analysis leads to a plausible explanation of some features of the observed variability. Comparison with previous results in the area indicate a marked interannual variability and sources of variability are discussed.Se estudia la evolución temporal del campo de isotermas asociados con movimientos frontales en el océano Atlántico Sudoccidental. El análisis está basado en datos obtenidos de ecosondas invertidos (IES) fondeados durante la ejecución del Programa Confluencia (1988-1990) en la confluencia de las corrientes de Malvinas y Brasil. Las series de tiempo obtenidas con los IES fueron estandarizados con las temperaturas medias de los primeros 500 m (T500) del océano y de esta forma se obtuvo la distribución horizontal de T500. Se presenta una descripción de la evolución del campo térmico en relación con los movimientos frontales y las características de mesoescala de esa zona. Se observaron tres penetraciones bien definidas de la corriente de Malvinas con períodos variables de permanencia (15 -60 días) y velocidades del frente de 0.2 m/s. Del análisis de la correlación cruzada de la serie de T500 se obtiene una posible explicación de la variabilidad observada. La comparación con resultados previos indican una variabilidad interanual. Se discuten las fuentes de variabilidad.Material digitalizado en SEDICI gracias a la colaboración de la Facultad de Ciencias Astronómicas y Geofísicas (UNLP).Asociación Argentina de Geofísicos y Geodesta

Apoptotic effects on HL60 human leukaemia cells induced by lavandin essential oil treatment

Recent scientific investigations have reported a number of essential oils to interfere with intracellular signalling pathways and to induce apoptosis in different cancer cell types. In this paper, Lavandin Essential Oil (LEO), a natural sterile hybrid obtained by cross-breeding L. angustifolia × L. latifolia, was tested on human leukaemia cells (HL60). Based on the MTT results, the reduced cell viability of HL60 cells was further investigated to determine whether cell death was related to the apoptotic process. HL60 cells treated for 24 h with LEO were processed by flow cytometry, and the presence of Annexin V was measured. The activation of caspases-3 was evaluated by western blot and immunofluorescence techniques. Treated cells were also examined by scanning and transmission electron microscopy to establish the possible occurrence of morphological alterations during the apoptotic process. LEO main compounds, such as linalool, linalyl acetate, 1,8-cineole, and terpinen-4-ol, were also investigated by MTT and flow cytometry analysis. The set of obtained results showed that LEO treatments induced apoptosis in a dose-dependent, but not time-dependent, manner on HL60 cells, while among LEO main compounds, both terpinen-4-ol and linalyl acetate were able to induce apoptosis

Comparison of two different classifiers for mental tasks-based Brain-Computer Interface: MLP Neural Networks vs. Fuzzy Logic

This study is devoted to the classification of fourclass mental tasks data for a Brain-Computer Interface protocol. In such view we adopted Multi Layer Perceptron Neural Network (MLP) and Fuzzy C-means analysis for classifying: left and right hand movement imagination, mental subtraction operation and mental recitation of a nursery rhyme. Five subjects participated to the experiment in two sessions recorded in distinct days. Different parameters were considered for the evaluation of the performances of the two classifiers: accuracy, that is, percentage of correct classifications, training time and size of the training dataset. The results show that even if the accuracies of the two classifiers are quite similar, the MLP classifier needs a smaller training set to reach them with respect to the Fuzzy one. This leads to the preference of MLP for the classification of mental tasks in Brain Computer Interface protocols