43 research outputs found
Analysis of cod-liver oil adulteration using Fourier Transform Infrared (FTIR) spectroscopy.
Analysis of the adulteration of cod-liver oil with much cheaper oil-like animal fats has become attractive in recent years. This study highlights an application of Fourier transform infrared (FTIR) spectroscopy as a nondestructive and fast technique for the determination of adulterants in cod-liver oil. Attenuated total reflectance measurements were made on pure cod-liver oil and cod-liver oil adulterated with different concentrations of lard (0.5–50% v/v in cod-liver oil). A chemometrics partial least squares (PLS) calibration model was developed for quantitative measurement of the adulterant. Discriminant analysis method was used to classify cod-liver oil samples from common animal fats (beef, chicken, mutton, and lard) based on their infrared spectra. Discriminant analysis carried out using seven principal components was able to classify the samples as pure or adulterated cod-liver oil based on their FTIR spectra at the selected fingerprint regions (1,500–1,030 cm−1)
Stress e Modelli Cognitivi di Simulazione
Abstract not availableNA-NOT AVAILABL
The issue of ground/cockpit integration: results from field studies
A pilot activity analysis has been performed to study the relation between the cognitive behaviour of an expert aircraft pilot and the worksystem. The cognitive demand of the pilot’s task is related to the level of automation (or mode) of the supporting tools. The mode choice stems both from a personal "flying style " and worksystem constraints. One of the most relevant constraints is the air traffic control operator’s requests. A study on air traffic control operator stress shows that this demand actually comes from flow management and is propagated from the ground to the cockpit. Thus, our research, based on natural setting observations, confirms that operators, and designers, from both ground and cockpit sides, should better cooperate and consider that there is one and only one worksystem
CCAAT-box binding protein NF-Y (CBF, CP1) recognizes the minor groove and distorts DNA.
The CCAAT box is one of the most common promoter elements. The evolutionarily conserved heteromeric factor NF-Y binds this sequence with high affinity and specificity. By comparing the methylation interference patterns of different sites, performing electrophoretic mobility shift assays (EMSA) with IC-substituted oligonucleotides and competition experiments with the minor groove binding (MGB) drugs distamicin A, tallimustine and Hoechst 33258 we show that NF-Y makes key minor groove interactions. Circular permutation assays on four CCAAT boxes, MHC Class II Ea, HSP70, epsilon-globin and MSV, indicate that NF-Y is able to distort the double helix by angles of 62-82 degrees, depending on the site used, and suggest that nucleotides flanking the CCAAT pentanucleotide influence the degree of bending
Cloning and expression of human NF-YC
The CCAAT box is an important element in eukaryotic promoters and NF-Y (CBF) is a conserved heterotrimeric protein binding to it. Two subunits, NF-YB and NF-YC, contain a histone-like motif. We cloned the complete cDNA coding for the human NF-YC gene. The ORF codes for a 335 aa protein that shows virtual identity to the rat sequence, confirming the stunning invariance of NF-Y genes across species. We expressed and purified the yeast homology domain of NF-YC in bacteria and performed EMSA together with the corresponding conserved domains of NF-YA and NF-YB, obtaining a CCAAT-binding mini-NF-Y. We evaluated the expression of NF-YC and found that mRNA levels are similar in different human tissues except in testis
Down-regulation of cyclin B1 gene transcription in terminally differentiated skeletal muscle cells is associated with loss of functional CCAAT-binding NF-Y complex
The observation that cyclin B1 protein and mRNAs are down-regulated in terminally differentiated (TD) C2C12 cells, suggested us to investigate the transcriptional regulation of the cyclin B1 gene in these cells. Transfections of cyclin B1 promoter constructs indicate that two CCAAT boxes support cyclin B1 promoter activity in proliferating cells. EMSAs demonstrate that both CCAAT boxes are recognized by the trimeric NF-Y complex in proliferating but not in TD cells. Transfecting a dominant-negative mutant of NF-YA we provide evidence that NF-Y is required for maximal promoter activity. Addition of recombinant NF-YA to TD C2C12 nuclear extracts restores binding activity in vitro, thus indicating that the loss of NF-YA in TD cells is responsible for the lack of the NF-Y binding to the CCAAT boxes. Consistent with this, we found that the NF-YA protein is absent in TD C2C12 cells. In conclusion, our data demonstrate that NF-Y is required for cyclin B1 promoter activity. We also demonstrate that cyclin B1 expression is regulated at the transcriptional level in TD C2C12 cells and that the switch-off of cyclin B1 promoter activity in differentiated cells depends upon the loss of a functional NF-Y complex. In particular the loss of NF-YA protein is most likely responsible for its inactivation
Authentication of feeding fats: classification of animal fats, fish oils and recycled cooking oils
Classification of fats and oils involves the recognition of one/several markers typical of the product. The ideal marker(s) should be specific to the fat or oil. Not many chemical markers fulfill these criteria. Authenticity assessment is a difficult task, which in most cases requires the measurement of several markers and must take into account natural and technology-induced variation. The present study focuses on the identity prediction of three by-products of the fat industry (animal fats, fish oils, recycled cooking oils), which may be used for animal feeding. Their identities were predicted by their triacylglycerol fingerprints, their fatty acid fingerprints and their profiles of volatile organic compounds. Partial least square discriminant analysis allowed samples to be assigned successfully into their identity classes. Most successful were triacylglycerol and fatty acid fingerprints (both 96% correct classification). Proton transfer reaction mass spectra of the volatile compounds predicted the identity of the fats in 92% of the samples correctly