X-ray Flashes or soft Gamma-ray Bursts? The case of the likely distant XRF 040912

In this work, we present a multi-wavelength study of XRF 040912, aimed at measuring its distance scale and the intrinsic burst properties. We performed a detailed spectral and temporal analysis of both the prompt and the afterglow emission and we estimated the distance scale of the likely host galaxy. We then used the currently available sample of XRFs with known distance to discuss the connection between XRFs and classical Gamma-ray Bursts (GRBs). We found that the prompt emission properties unambiguously identify this burst as an XRF, with an observed peak energy of E_p=17+/-13 keV and a burst fluence ratio S(2-30keV)/S(30-400keV)>1. A non-fading optical source with R~24 mag and with an apparently extended morphology is spatially consistent with the X-ray afterglow, likely the host galaxy. XRF 040912 is a very dark burst since no afterglow optical counterpart is detected down to R>25 mag (3 sigma limiting magnitude) at 13.6 hours after the burst. The host galaxy spectrum detected from 3800A to 10000A, shows a single emission line at 9552A. The lack of any other strong emission lines blue-ward of the detected one and the absence of the Ly alpha cut-off down to 3800A are consistent with the hypothesis of the [OII] line at redshift z=1.563+/-0.001. The intrinsic spectral properties rank this XRF among the soft GRBs in the E_peak-E_iso diagram. Similar results were obtained for most XRFs at known redshift. Only XRF 060218 and XRF 020903 represent a good example of instrinsic XRF(i-XRF) and are possibly associated with a different progenitor population. This scenario may calls for a new definition of XRFs.Comment: 10 pages, 7 figures, accepted for publication in Astronomy & Astrophysic

Nuclear and cytoplasmic expression of survivin in 67 surgically resected pancreatic cancer patients

Pancreatic cancer is one of the most aggressive gastrointestinal cancer with less than 10% long-term survivors. The apoptotic pathway deregulation is a postulated mechanism of carcinogenesis of this tumour. The present study investigated the prognostic role of apoptosis and apoptosis-involved proteins in a series of surgically resected pancreatic cancer patients. All patients affected by pancreatic adenocarcinoma and treated with surgical resection from 1988 to 2003 were considered for the study. Patients' clinical data and pathological tumour features were recorded. Survivin and Cox-2 expression were evaluated by immunohistochemical staining. Apoptotic cells were identified using the TUNEL method. Tumour specimen of 67 resected patients was included in the study. By univariate analysis, survival was influenced by Survivin overexpression. The nuclear Survivin overexpression was associated with better prognosis (P=0.0009), while its cytoplasmic overexpression resulted a negative prognostic factor (P=0.0127). Also, the apoptotic index was a statistically significant prognostic factor in a univariate model (P=0.0142). By a multivariate Cox regression analysis, both the nuclear (P=0.002) and cytoplasmic (P=0.040) Survivin overexpression maintained the prognostic statistical value. This is the first study reporting a statistical significant prognostic relevance of nuclear and cytoplasmic Survivin overexpression in pancreatic cancer. In particular, patients with high nuclear Survivin staining showed a longer survival, whereas patients with high cytoplasmic Survivin staining had a shorter overall survival

Adaptation in Amarone wine of indigenous Oenococcus oeni strains differentiated by pulsed-field gel electrophoresis.

In the present study, 45 lactic acid bacteria strains isolated from Amarone wine were identified as Oenococcus oeni and genetically differentiated by Pulsed-Field Gel Electrophoresis (PFGE). Twenty different PFGE profiles were recognized by a numerical analysis. Twelve strains displayed unique PFGE profiles. Based on these results, representative strains of each genomic group were selected to determine their ability to survive and to induce malolactic fermentation, when inoculated in Amarone wine. The microvinification trials highlighted the different capability of the tested strains to adapt in wine and to convert L-malic acid. Only four out of the fourteen strains, which survived after inoculation in wine, demonstrated to have a good malolactic performance

Rapid detection of viable yeast and bacteria in wine by flow cytometry

The potential of using flow cytometry (FCM) in combination with fluorescent dyes for rapidly estimating counts of yeasts and malolactic bacteria in laboratory media and wines was examined. In general, there was a good correlation (regression coefficient, 0.94) between viable counts of yeasts determined by FCM and by standard plate assay. The FCM detection limit of yeasts in YPDE medium and in Pinot noir must was 103 cells/ml. The lowest bacterial concentration detected by FCM was 104 cells/ml. When yeast and malolactic bacteria populations were simultaneously analysed in wine by FCM without any previous sample treatment, difficulties were encountered in the count of bacterial cells due to their size, which is similar to natural debries present in wine. However, after the optimisation of the sample preparation, the technique appeared promising in determining the presence of such microorganisms in wine with one single measurement. Because it is rapid and easy to use, flow cytometry can be considered a useful method for microbiological quality control in wineries and for the investigation of the growth dynamics of microorganisms in wine

Saccharomyces bayanus var. uvarum and Saccharomyces cerevisiae succession during spontaneous fermentation of Recioto and Amarone wines

This study was undertaken to evaluate the biodiversity of the indigenous Saccharomyces sensu stricto population during traditional vinification processes of Recioto and Amarone wines using molecular typing techniques. In total 109 isolates, collected from eight wineries during spontaneous fermentations, were identified and characterised by conventional tests and by molecular methods, i.e. PCR fingerprinting using the primer (GTG)5, mtDNA restriction and karyotype analyses. Sixty per cent of the isolates were assigned to Saccharomyces bayanus var. uvarum and 40% to Saccharomyces cerevisiae. A succession between S. bayanus var. uvarum, which dominated the first fermentation, and S. cerevisiae, which appeared after the wine drawing-off operation, was observed during a traditional Amarone winemaking. An extensive polymorphism was found between the isolates, however a few specific genetic biotypes prevailed in the different wineries. This ecotaxonomic survey constitutes a basic step to safeguard and exploit the oenological potential of the yeast biodiversity in the Recioto and Amarone wine ecosystems. Such biodiversity could be further explored to correlate the genetic patterns of the isolates with oenologically useful characteristics, with the ultimate goal to carry out selection programmes of typical strains of the Valpolicella area

Interactions between Saccharomyces and Oenococcus oeni strains from Amarone wine affect malolactic fermentation and wine composition.

This study evaluated the ability of Saccharomyces strains isolated from Amarone wine to induce malolactic fermentation in model fermentations. The results suggest that the interactions of different yeast and malolactic bacteria starins can influence MLF and the aromatic traits of wines

Rapid identification and differentiation of Saccharomyces cerevisiae, Saccharomyces bayanus and their hybrids by multiplex PCR

Aims: To develop a multiplex PCR assay for the specific identification and differentiation of Saccharomyces cerevisiae, S. bayanus and their hybrids. Methods and Results: Two sets of primers with sequences complementary to the region YBR033w were used. A single amplicon of 1710 bp or 329 bp was obtained with species S. cerevisiae and S. bayanus, respectively, while the presence of both bands was observed in S. pastorianus because of its hybrid nature. Both amplification products were also obtained after amplification from DNA of several laboratory S. cerevisiae x S. bayanus hybrid strains. Conclusions: Multiplex PCR was optimized for the rapid and reliable identification of S. cerevisiae, S. bayanus and their hybrids. Significance and Impact of the Study: The procedure may be used for routine detection of the most common Saccharomyces sensu stricto yeasts involved in industrial fermentation processes, overcoming the problems of conventional techniques