Specific oligomerization of the 5-HT1A receptor in the plasma membrane

In the present study we analyze the oligomerization of the 5-HT1A receptor within living cells at the sub-cellular level. Using a 2-excitation Förster Resonance Energy Transfer (FRET) method combined with spectral microscopy we are able to estimate the efficiency of energy transfer based on donor quenching as well as acceptor sensitization between CFP-and YFP-tagged 5-HT1A receptors at the plasma membrane. Through the analysis of the level of apparent FRET efficiency over the various relative amounts of donor and acceptor, as well as over a range of total surface expressions of the receptor, we verify the specific interaction of these receptors. Furthermore we study the role of acylation in this interaction through measurements of a palmitoylation-deficient 5-HT1A receptor mutant. Palmitoylation increases the tendency of a receptor to localize in lipid rich microdomains of the plasma membrane. This increases the effective surface density of the receptor and provides for a higher level of stochastic interaction

The Great Markarian 421 Flare of 2010 February: Multiwavelength Variability and Correlation Studies

We report on variability and correlation studies using multiwavelength observations of the blazar Mrk 421 during the month of 2010 February, when an extraordinary flare reaching a level of ∼27 Crab Units above 1 TeV was measured in very high energy (VHE) γ-rays with the Very Energetic Radiation Imaging Telescope Array System (VERITAS) observatory. This is the highest flux state for Mrk 421 ever observed in VHE γ-rays. Data are analyzed from a coordinated campaign across multiple instruments, including VHE γ-ray (VERITAS, Major Atmospheric Gamma-ray Imaging Cherenkov), high-energy γ-ray (Fermi-LAT), X-ray (Swift, Rossi X-ray Timing Experiment, MAXI), optical (including the GASP-WEBT collaboration and polarization data), and radio (Metsahovi, Owens Valley Radio Observatory, University of Michigan Radio Astronomy Observatory). Light curves are produced spanning multiple days before and after the peak of the VHE flare, including over several flare "decline" epochs. The main flare statistics allow 2 minute time bins to be constructed in both the VHE and optical bands enabling a cross-correlation analysis that shows evidence for an optical lag of ∼25-55 minutes, the first time-lagged correlation between these bands reported on such short timescales. Limits on the Doppler factor (δ ⪆ 33) and the size of the emission region (δ-1RB≲ 3.8 × 1013cm) are obtained from the fast variability observed by VERITAS during the main flare. Analysis of 10 minute binned VHE and X-ray data over the decline epochs shows an extraordinary range of behavior in the flux-flux relationship, from linear to quadratic to lack of correlation to anticorrelation. Taken together, these detailed observations of an unprecedented flare seen in Mrk 421 are difficult to explain with the classic single-zone synchrotron self-Compton model.</p

Geologia forense. Le indagini sui terreni e sui loro componenti organici ed inorganici

In ambito investigativo giudiziario si fa oggigiorno sempre più uso delle tracce di terreno presenti sulla scena di un crimine per ottenere importanti informazioni sia sulla dinamica di un reato che sul suo presunto autore. Il geologo forense, specialista in questa disciplina, può di conseguenza fornire delle indicazioni utili alle indagini, che in alcune circostanze possono rivelarsi risolutive

Geologia forense. La falsificazione dei materiali geologici preziosi

Le gemme e i metalli preziosi non attirano l’uomo solo per la loro bellezza; l’alto valore economico, le piccole dimensioni e la relativa non tracciabilità hanno fatto si che tali materiali siano anche estremamente allettanti per la criminalità organizzata

Application of differential scanning calorimetry-chemometric coupled procedure to the evaluation of thermo-oxidation on extra virgin olive oil

In this work, the opportunity of adopting a differential scanning calorimetry (DSC)-principal component analysis (PCA) coupled procedure to measure the degree of thermal stress for extra virgin olive oil (EVOO) was presented. Oil was subjected to thermal stress under convectional or microwave heating treatments at different heating times up to 1,440 and 15 min, respectively, and p-anisidine values (PAV) were obtained on all samples to measure their oxidative degradation. The entire DSC profiles obtained on the oil upon cooling in the range from 30 °C to –80 °C and subsequent re-heating to 30 °C at different times and under cooking procedures have been subjected to PCA data analysis. PCA discriminated samples by means of profile changes in DSC transition both upon cooling and heating not only according to treatment times (which accounted for the degree of thermo-oxidation) but also considering different heating process. The proposed procedure may be useful to measure oil thermal stress and to select appropriate heating condition to be applied for EVOO both in industrial and/or in food-catering sectors

A novel chemometric strategy for the estimation of extra virgin olive oil adulteration with edible oils

Abstract A useful procedure for the qualitative and quantitative determination of vegetable oils (canola, hazelnut, pomace and high linoleic/oleic sunflower) as adulterants in commercial samples of extra virgin olive oil, has been developed. Partial least squares (PLS) was employed for the analysis of Fourier transform infrared spectroscopy (FTIR) spectral data of the blend oil samples. Calibration models were constructed for extra virgin olive oil purity, with wavelength selection in the infrared region, according to their predictive ability, with first derivative and mean centering used as data pretreatment. PLS models were internally validated by the leave-one-out procedure. The method developed was very suitable for the determination of modeled adulterants but it may also reveal an adulteration even if it does not derive from the adulterants employed in this study

Application of partial least square regression to differential scanning calorimetry data for fatty acid quantitation in olive oil

A chemometric approach based on partial least (PLS) square methodology was applied to unfolded differential scanning calorimetry data obtained by 63 samples of different vegetable oils (58 extra virgin olive oils, one olive and one pomace olive oil, three seed oils) to evaluate fatty acid composition (palmitic, stearic, oleic and linoleic acids, saturated (SFA), mono (MUFA) and polysaturated (PUFA) percentages, oleic/linoleic and unsaturated/saturated ratios). All calibration models exhibited satisfactory figures of merit. Palmitic and oleic acids, as well as SEA showed very good correlation coefficients and low root mean square error values in both calibration and validation sets. Satisfactory results were also obtained for MUFA, PUFA, stearic and linoleic acids, O/L ratio in terms of percentage recoveries and relative standard deviations. No systematic and bias errors were detected in the prediction of validation samples. This novel approach could provide statistically similar results to those given by traditional official procedures, with the advantages of a very rapid and environmentally friendly methodology