The kinetics of folding of the NSH2 domain from p85

SH2 domains are protein domains that mediate protein-protein interaction through the recognition and binding of specific sequences containing phosphorylated tyrosines. The p85 protein is the regulatory subunit of the heterodimeric enzyme PI3K, an important enzyme involved in several molecular pathways. In this work we characterize the folding kinetics of the NSH2 domain of p85. Our data clearly reveal peculiar folding kinetics, characterized by an apparent mismatch between the observed folding and unfolding kinetics. Taking advantage of double mixing stopped flow experiments and site directed mutagenesis we demonstrate that such behavior is due to the cis/trans isomerization of the peptide bond between D73 and P74, being in a cis conformation in the native protein. Our data are discussed in comparison with previous works on the folding of other SH2 domains

Optimization of a fluorescence polarization immunoassay for rapid quantification of deoxynivalenol in durum wheat-based products.

A fluorescence polarization immunoassay previously described for deoxynivalenol (DON) screening in wheat was optimized for the rapid quantification of DON in durum wheat kernels, semolina, and pasta. A background signal was observed in both spiked and naturally contaminated samples, strictly depending on the testing matrix. After subtracting the background DON level for durum wheat (0.27 microg of DON per g), semolina (0.08 microg of DON per g), and pasta (0.04 microg of DON per g), an accurate quantification of DON was possible at levels greater than 0.10 microg/g for all matrices. Average recoveries from spiked samples (0.25 to 1.75 microg/g) were 98, 102, and 101% for wheat, semolina, and pasta, respectively. Comparative analyses of 35 naturally contaminated durum wheat samples, 22 semolina samples, and 26 pasta samples performed by both the fluorescence polarization method and high-pressure liquid chromatography/immunoaffinity cleanup showed a good correlation (r0.995). The fluorescence polarization method showed better accuracy and precision with respect to the high-pressure liquid chromatography method and is suitable for the rapid and quantitative determination of DON in durum wheat-based products at levels foreseen by existing or coming international regulations

Feed-forward neural network assisted by discriminant analysis for the spectroscopic discriminantion of cracked spores Ganoderma lucidum: A prospective biotechnology production tool

A major problem for manufacturers of cracked spores Ganoderma lucidum, a traditional functional food/Chinese medicine (TCM), is to ensure that raw materials are consistent as received from the producer. To address this, a feed-forward artificial neural network (ANN) method assisted by linear discriminant analysis (LDA) and principal component analysis (PCA) was developed for the spectroscopic discrimination of cracked spores of Ganoderma lucidum from uncracked spores. 120 samples comprising cracked spores, uncracked spores and concentrate of Ganoderma lucidum were analyzed. Differences in the absorption spectra located at ν1 (1143 - 1037 cm-1), ν2 (1660 - 1560 cm-1), ν3 (1745 - 1716 cm-1) and ν4 (2845 - 2798 cm-1) were identified by applying fourier transform infra-red (FTIR) spectroscopy and used as variables for discriminant analysis. The utilization of spectra frequencies offered maximum chemical information provided by the absorption spectra. Uncracked spores gave rise to characteristic spectrum that permitted discrimination from its cracked physical state. Parallel application of variables derived from unsupervised LDA/PCA provided useful (feed-forward) information to achieve 100% classification integrity objective in ANN. 100% model validation was obtained by utilizing 30 independent samples. ν1 was used to construct the matrix-matched calibration curve (n = 10) based on 4 levels of concentration (20%, 40%, 60% and 80% uncracked spores in cracked spores). A coefficient of correlation (r) of 0.97 was obtained. Relative standard deviation (RSD) of 11% was achieved using 100% uncracked spores (n = 30). These results demonstrate the feasibility of utilizing a combination of spectroscopy and prospective statistical tools to perform non destructive food quality assessment in a high throughput environment

Features, operation principle and limits of SPI and I2C communication protocols for smart objects: a novel SPI-based hybrid protocol especially suitable for IoT applications

The Internet of Things (IoT) is an expression, sometimes abused by companies given the absence of an unambiguous meaning, that indicates the upcoming evolution of Internet as it has been known so far. In fact, all objects will have network capabilities which will be exploited to overcome, in certain situations, human intervention. Thanks to the direct cooperation of new class of devices, aware of their operating scenario and interconnected in subnetworks, our life style will be strongly enhanced and simplified. IoT, however, is not yet the “El Dorado” of technology, capable of revolutionizing everyday life: some aspects and open issues have to be carefully analyzed. The huge complexity of this new technology forces companies to select a specific research field: for this reason, they focus only on some features that an IoT device should have to guarantee fulfillment of requirements. In this context, this research work concerns an analysis of features, operation principle and limits of SPI and I2C communication protocols followed by the proposal of a new hybrid protocol suited for embedded systems, named FlexSPI, thought as an evolution of the classic SPI. Thanks to a robust software architecture, it is able to provide many features that can be used by smart objects to enhance their capabilities. In this way, sensors and actuators or, more in general, subsystems, can quickly exchange data and efficiently react to malfunctioning; moreover, number of devices on bus can be safely increased even while smart object is performing operations

Influence of Lobesia botrana field control on black aspergilli rot and ochratoxin A contamination in grapes.

The grape berry moth Lobesia botrana is a key pest in vineyards in southern Europe. Damage caused by L. botrana larvae may encourage growth of black aspergilli, leading to ochratoxin A (OTA) accumulation in grapes. Field trials were conducted during three grape growing seasons (2005 through 2007) in Apulia, Italy, to evaluate an insecticide control strategy for L. botrana in the vineyard as an indirect method of reducing OTA contamination by reducing black aspergilli on the grapes. In the 2005 field trials, the insecticide treatment controlled attacks by L. botrana larvae and reduced OTA concentrations by up to 66% in the must samples of Negroamaro and Primitivo grape varieties. Significant differences (P < or = 0.05) also were observed in the incidence of black aspergilli. Environmental conditions in 2006 and 2007 resulted in a natural low level of infestation by L. botrana, low levels of OTA in both treated and untreated samples, and no significant differences between treated and nontreated samples. The results of our field study confirm previous reports that L. botrana is an important risk factor for OTA accumulation and are consistent with the hypothesis that controlling L. botrana in vineyards reduces OTA concentrations in grapes

Raširenost bovericina u hrvatskom kukuruzu

The occurrence of beauvericin has been investigated in corn kernel (Zea mays L.) samples collected in 1996 (105 samples) and 1997 (104 samples) from 14 corn-producing counties of Croatia. Corn sample extracts were cleaned up by silica gel minicolumns and analyzed for beauvericin by high performance liquid chromatography with UV diode array detector. Higher incidence of positive samples was found in the 1996 crop as compared to the 1997 crop. In particular, 18 samples (17.4 %) of the 1996 crop were found contaminated with a mean beauvericin content of 393 ng/g and the highest level at 1864 ng/g. Only 1 out of 104 samples collected in the 1997 crop was contaminated with 696 ng/g of the toxin.n Beauvericin co-occurred with fumonisins B1 and B2 and with ochratoxin A in 17 and 4 samples, respectively. The results of mycological analysis of corn samples for beauvericin producing Fusarium species were in agreement with results of chemical analysis. In particular, higher incidence of Fusarium verticillioides (Sacc.) Nirenberg (known as Fusarium moniliforme Sheldon) (3.7 %) and Fusarium subglutinans (Wollenweber & Reinking) Nelson, Toussoun & Marasas (5.3 %) was found in 1996 with respect to 1997 (1.9 % of F. verticillioides and 0.4 % of F. subglutinans). This is the first report on the occurrence of beauvericin in Croatia.Učestalost bovericina analizirana je u uzorcima kukuruza skupljenim tijekom 1996. (105 uzoraka) i 1997. godine (104 uzorka) iz 14 županija Republike Hrvatske. Ekstrakt uzoraka kukuruza pročišćen je na silicij-gelskim minikolonama i analiziran na bovericin s tekućinskim kromatografom velike učinkovitosti (HPLC) s UV-diodnim detektorom. Učestalija pojava pozitivnih uzoraka nađena je godine 1996. u usporedbi s 1997. godinom. Godine 1996. nađeno je 18 uzoraka (17,4 %) kontaminiranih bovericinom sa srednjom vrijednošću pozitivnih uzoraka od 393 ng/g, odnosno s najvećom količinom od 1864 ng/g. Samo 1 od 104 skupljena uzorka godine 1997. bio je onečišćen s 696 ng/g toksina. Bovericin je nađen zajedno s fumonizinom B1 i B2 u 17 uzoraka, a s okratoksinom A samo u 4 uzorka. Mikološkom analizom utvrđene Fusarium vrste slažu se s kemijskim analizama na mikotoksine. Veća pojava Fusarium verticillioides (Sacc.) Nirenberg (poznat i kao Fusarium moniliforme Sheldon) (3,7 %) i F. subglutinans (Wollenweber & Reinking) Nelson, Toussoun & Marasas (5,3 %) nađena je godine 1996. u usporedbi s 1997. godinom kada je ustanovljeno (1,9 %) F. verticillioides i (0,4 %) F. subglutinans. Ovo je prvo izvješće o prisutnosti bovericina u Republici Hrvatskoj

Raširenost bovericina u hrvatskom kukuruzu

The occurrence of beauvericin has been investigated in corn kernel (Zea mays L.) samples collected in 1996 (105 samples) and 1997 (104 samples) from 14 corn-producing counties of Croatia. Corn sample extracts were cleaned up by silica gel minicolumns and analyzed for beauvericin by high performance liquid chromatography with UV diode array detector. Higher incidence of positive samples was found in the 1996 crop as compared to the 1997 crop. In particular, 18 samples (17.4 %) of the 1996 crop were found contaminated with a mean beauvericin content of 393 ng/g and the highest level at 1864 ng/g. Only 1 out of 104 samples collected in the 1997 crop was contaminated with 696 ng/g of the toxin.n Beauvericin co-occurred with fumonisins B1 and B2 and with ochratoxin A in 17 and 4 samples, respectively. The results of mycological analysis of corn samples for beauvericin producing Fusarium species were in agreement with results of chemical analysis. In particular, higher incidence of Fusarium verticillioides (Sacc.) Nirenberg (known as Fusarium moniliforme Sheldon) (3.7 %) and Fusarium subglutinans (Wollenweber & Reinking) Nelson, Toussoun & Marasas (5.3 %) was found in 1996 with respect to 1997 (1.9 % of F. verticillioides and 0.4 % of F. subglutinans). This is the first report on the occurrence of beauvericin in Croatia.Učestalost bovericina analizirana je u uzorcima kukuruza skupljenim tijekom 1996. (105 uzoraka) i 1997. godine (104 uzorka) iz 14 županija Republike Hrvatske. Ekstrakt uzoraka kukuruza pročišćen je na silicij-gelskim minikolonama i analiziran na bovericin s tekućinskim kromatografom velike učinkovitosti (HPLC) s UV-diodnim detektorom. Učestalija pojava pozitivnih uzoraka nađena je godine 1996. u usporedbi s 1997. godinom. Godine 1996. nađeno je 18 uzoraka (17,4 %) kontaminiranih bovericinom sa srednjom vrijednošću pozitivnih uzoraka od 393 ng/g, odnosno s najvećom količinom od 1864 ng/g. Samo 1 od 104 skupljena uzorka godine 1997. bio je onečišćen s 696 ng/g toksina. Bovericin je nađen zajedno s fumonizinom B1 i B2 u 17 uzoraka, a s okratoksinom A samo u 4 uzorka. Mikološkom analizom utvrđene Fusarium vrste slažu se s kemijskim analizama na mikotoksine. Veća pojava Fusarium verticillioides (Sacc.) Nirenberg (poznat i kao Fusarium moniliforme Sheldon) (3,7 %) i F. subglutinans (Wollenweber & Reinking) Nelson, Toussoun & Marasas (5,3 %) nađena je godine 1996. u usporedbi s 1997. godinom kada je ustanovljeno (1,9 %) F. verticillioides i (0,4 %) F. subglutinans. Ovo je prvo izvješće o prisutnosti bovericina u Republici Hrvatskoj

Effects of muffin processing on fumonisins from 14C-labeled toxins produced in cultured corn kernels.

The persistence of fumonisins during cooking is known to be affected by several factors, including thermal degradation and the presence of various ingredients in corn-based food recipes that can react with the toxin. A method for the production of corn kernels containing 14C-fumonisins was developed. The corn kernels were colonized by Fusarium verticillioides MRC 826 and supplemented with 1,2-14C-sodium acetate. The specific activity of 14C-FB1 produced made the study of its fate in cornmeal muffins possible. The double-extraction acetonitrile-water-methanol/immunoaffinity column/o-phthaldialdehyde high-performance liquid chromatography (HPLC) method was used to determine FB1 levels in cornmeal muffins. Reductions in FB1 levels in muffins spiked with 14C-labeled and unlabeled FB1 (43 and 48%, respectively) were similar, indicating that the extraction method was efficient and consistent with previous reports. However, with the labeled corn kernel material, recovery levels based on the 14C counts for the eluate from an immunoaffinity column were much higher (90%). This finding indicates that some fumonisin-related compounds other than FB1 that were present in the cornmeal were recognized by the antibodies but not by the HPLC method

FEATURES, OPERATION PRINCIPLE AND LIMITS OF SPI AND I2C COMMUNICATION PROTOCOLS FOR SMART OBJECTS: A NOVEL SPI-BASED HYBRID PROTOCOL ESPECIALLY SUITABLE FOR IoT APPLICATIONS

The Internet of Things (IoT) is an expression, sometimes abused by companies given the absence of an unambiguous meaning, that indicates the upcoming evolution of Internet as it has been known so far. In fact, all objects will have network capabilities which will be exploited to overcome, in certain situations, human intervention. Thanks to the direct cooperation of new class of devices, aware of their operating scenario and interconnected in subnetworks, our life style will be strongly enhanced and simplified. IoT, however, is not yet the “El Dorado” of technology, capable of revolutionizing everyday life: some aspects and open issues have to be carefully analyzed. The huge complexity of this new technology forces companies to select a specific research field: for this reason, they focus only on some features that an IoT device should have to guarantee fulfillment of requirements. In this context, this research work concerns an analysis of features, operation principle and limits of SPI and I2C communication protocols followed by the proposal of a new hybrid protocol suited for embedded systems, named FlexSPI, thought as an evolution of the classic SPI. Thanks to a robust software architecture, it is able to provide many features that can be used by smart objects to enhance their capabilities. In this way, sensors and actuators or, more in general, subsystems, can quickly exchange data and efficiently react to malfunctioning; moreover, number of devices on bus can be safely increased even while smart object is performing operations