Search results for " GC"

Degradation of long-chain n-alkanes in soil microcosms by two actinobacteria

2012

The ability of two recently isolated actinobacteria, that degrade medium and long chain n-alkanes in laboratory water medium, was investigated in soil microcosms using different standard soils that were artificially contaminated with n-alkanes of different length (C(12)- C(20)- C(24)- C(30)). The two strains, identified as Nocardia sp. SoB and Gordonia sp. SoCp, revealed a similar high HC degradation efficiency with an average of 75% alkane degraded after 28 days incubation. A selectivity of bacteria towards n-alkanes of different length was detected as well as a consistent effect of soil texture and other soil physical chemical characteristics on degradation. It was demonstrated the specif…

Gcn5p is involved in the acetylation of histone H3 in nucleosomes.

1997

Abstract Enzymatic extracts from a gcn5 mutant and wild-type strains of Saccharomyces cerevisiae were chromatographically fractionated and the histone acetyltransferase activities compared. When free histones were used as substrate, extracts from wild-type cells showed two peaks of activity on histone H3 but extracts from gcn5 mutant cells showed only one. With nucleosomes as substrate, the histone acetyltransferase activities present in extracts from the gcn5 mutant strain were not able to modify H3 whereas wild-type cell extracts acetylated intensely this histone. The activity that acetylated nucleosome-bound H3 behaved as a 170-kDa complex. We suggest that Gcn5p represents a catalytic su…

Exploring the chemical diversity of essential oils in Armenian markets: a comprehensive analysis of composition profiles

2023

Due to its location at the convergence of multiple biogeographical regions, Armenia experiences significant variations in climate and soil conditions, resulting in a diverse range of plant chemotypes. However, there has been a lack of recent reports on the biological activity of plants found in Armenia's flora. There are few with well-described essential oil profiles, despite the vast biodiversity of Armenian flora. This study aimed to analyse the chemical composition of essential oils used by the population and found in the Armenian market. Unfortunately, only essential oils of foreign origin can be found, like Russia. Three essential oils of Lavandula angustifolia, Abies sibirica, and Ros…

Hydrological regime modifications induced by climate change in Mediterranean area

2015

The knowledge of river flow regimes has a capital importance for a variety of practical applications, in water resource management, including optimal and sustainable use. Hydrological regime is highly dependent on climatic factors, among which the most important is surely the precipitation, in terms of frequency, seasonal distribution and intensity of rainfall events. The streamflow frequency regime of river basins are often summarized by flow duration curves (FDCs), that offer a simple and comprehensive graphical view of the overall historical variability associated with streamflow, and characterize the ability of the basin to provide flows of various magnitudes. Climate change is likely t…

Tuning parameter selection in LASSO regression

2016

We propose a new method to select the tuning parameter in lasso regression. Unlike the previous proposals, the method is iterative and thus it is particularly efficient when multiple tuning parameters have to be selected. The method also applies to more general regression frameworks, such as generalized linear models with non-normal responses. Simulation studies show our proposal performs well, and most of times, better when compared with the traditional Bayesian Information Criterion and Cross validation.

Cultura dei gruppi di lavoro nei setting di strada: osservazione attraverso il questionario sul clima di gruppo di MacKenzie

2004

EVALUMION OF THE CHEMICAL PHYSICAL DIFFERENCES AMONG SICILIAN HONEYS

2009

Applicazioni di spettrometria di massa in campo alimentare: analisi di olii di oliva tramite HPLC-Ms e HS-SPME-GC-MS

2008

Land Snails as a Valuable Source of Fatty Acids: A Multivariate Statistical Approach

2019

The fatty acid (FA) profile of wild Theba pisana, Cornu aspersum, and Eobania vermiculata land snail samples, collected in Sicily (Southern Italy), before and after heat treatment at +100 °C were examined by gas chromatography with a flame ionization detector (GC-FID). The results show a higher content of polyunsaturated fatty acids (PUFAs) in all of the examined raw snails samples, representing up to 48.10% of the total fatty acids contents, followed by monounsaturated fatty acids (MUFAs). The thermal processing of the snail samples examined determined an overall reduction of PUFA levels (8.13%, 7.75%, and 4.62% for T. pisana, C. aspersum and E. vermiculata samples, respectively) and a spe…

New insights into the composition of historical remedies and pharmaceutical formulations: the identification of natural resins and balsams by gas chr…

2020

AbstractThe present paper reports one of the first studies on the identification of natural resins and balsams in modern era drug formulations. Gas chromatography coupled with mass spectrometry (GC-MS) was applied to investigate the composition of ancient remedies and pharmaceutical formulations coming from the Spezieria di Santa Maria della Scala in Rome, founded at the end of the seventeenth century by the Discalced Carmelites. The obtained results highlight the presence of complex mixtures containing resinaceous and lipidic-based compounds. Thanks to the detection of characteristic markers, it was possible to identify several natural resins, such as guaiacum resin, ladano resin and scamm…