172 research outputs found
Do best-selected strains perform table olive fermentation better than undefined biodiverse starters? A comparative study
Twenty-seven Lactobacillus pentosus strains, and the undefined starter for table olives from which they were isolated, were characterised for their technological properties: tolerance to low temperature, high salt concentration, alkaline pH, and olive leaf extract; acidifying ability; oleuropein degradation; hydrogen peroxide and lactic acid production. Two strains with appropriate technological properties were selected. Then, table olive fermentation in vats, with the original starter, the selected strains, and without starter (spontaneous fermentation) were compared. Starters affected some texture profile parameters. The undefined culture resulted in the most effective Enterobacteriaceae reduction, acidification and olive debittering, while the selected strains batch showed the lowest antioxidant activity. Our results show that the best candidate strains cannot guarantee better fermentation performance than the undefined biodiverse mix from which they originate
Growth performance of cork oak plantations recently established on farmlands in Sardinia, Italy
A soft and transient ultraluminous X-ray source with 6-h modulation in the NGC 300 galaxy
We investigate the nature of CXOU J005440.5-374320 (J0054), a peculiar bright
( erg/s) and soft X-ray transient in the spiral galaxy
NGC 300 with a 6-hour periodic flux modulation that was detected in a 2014
Chandra observation. Subsequent observations with Chandra and XMM-Newton, as
well as a large observational campaign of NGC 300 and its sources performed
with the Swift Neil Gehrels Observatory, showed that this source exhibits
recurrent flaring activity: four other outbursts were detected across 8
years of monitoring. Using data from the Swift/UVOT archive and from the
XMM-Newton/OM and Gaia catalogues, we noted the source is likely associated
with a bright blue optical/ultraviolet counterpart. This prompted us to perform
follow-up observations with the Southern African Large Telescope in December
2019. With the multi-wavelength information at hand, we discuss several
possibilities for the nature of J0054. Although none is able to account for the
full range of the observed peculiar features, we found that the two most
promising scenarios are a stellar-mass compact object in a binary system with a
WolfRayet star companion, or the recurrent tidal stripping of a stellar
object trapped in a system with an intermediate-mass ( )
black hole.Comment: 13 pages, 11 Figures, 3 Tables (the Table in appendix A will be
available in the published version). Accepted for publication in A&
Médecine interne hospitalière dans un hôpital régional : enjeux du présent et défis pour le futur.
Prognostic role of KRAS mutations in Sardinian patients with colorectal carcinoma
The presence of mutations in the KRAS gene is a predictor of a poor clinical response to EGFR-targeted agents in patients affected by colorectal cancer (CRC), but its significance as a global prognostic factor remains unclear. The aim of the present study was to evaluate the impact of the KRAS mutational status on time to first metastasis (TTM) and overall survival (OS) in a cohort of Sardinian CRC patients. A total of 551 patients with metastatic CRC at the time of enrolment were included. Clinical and pathological features of the disease, including follow-up information, were obtained from medical records and cancer registry data. For mutational analysis formalin-fixed paraffin-embedded tissue samples were processed using a standard protocol. The coding sequence and splice junctions of exons 2 and 3 of the KRAS gene were screened for mutations by direct automated sequencing. Overall, 186 KRAS mutations were detected in 183/551 (33%) patients: 125 (67%) were located in codon 12, 36 (19%) in codon 13, and 18 (10%) in codon 61. The remaining mutations (7; 4%) were detected in uncommonly-affected codons. No significant correlation between KRAS mutations and gender, age, anatomical location and stage of the disease at the time of diagnosis was identified. Furthermore, no prognostic value of KRAS mutations was found considering either TTM or OS. When patients were stratified by KRAS mutational status and gender, males were significantly associated with a longer TTM. The results of the present study indicate that KRAS mutation correlated with a slower metastatic progression in males with CRC from Sardinia, irrespective of the age at diagnosis and the codon of the mutatio
Rapid mechanosensitive migration and dispersal of newly divided mesenchymal cells aid their recruitment into dermal condensates
Embryonic mesenchymal cells are dispersed within an extracellular matrix but can coalesce to form condensates with key developmental roles. Cells within condensates undergo fate and morphological changes and induce cell fate changes in nearby epithelia to produce structures including hair follicles, feathers, or intestinal villi. Here, by imaging mouse and chicken embryonic skin, we find that mesenchymal cells undergo much of their dispersal in early interphase, in a stereotyped process of displacement driven by 3 hours of rapid and persistent migration followed by a long period of low motility. The cell division plane and the elevated migration speed and persistence of newly born mesenchymal cells are mechanosensitive, aligning with tissue tension, and are reliant on active WNT secretion. This behaviour disperses mesenchymal cells and allows daughters of recent divisions to travel long distances to enter dermal condensates, demonstrating an unanticipated effect of cell cycle subphase on core mesenchymal behaviour
Spatial abundance and clustering of Culicoides (Diptera: Ceratopogonidae) on a local scale
BACKGROUND: Biting midges, Culicoides, of the Obsoletus group and the Pulicaris group have been involved in recent outbreaks of bluetongue virus and the former was also involved in the Schmallenberg virus outbreak in northern Europe. METHODS: For the first time, here we investigate the local abundance pattern of these two species groups in the field by intensive sampling with a grid of light traps on 16 catch nights. Neighboring trap catches can be spatially dependent on each other, hence we developed a conditional autoregressive (CAR) model framework to test a number of spatial and non-spatial covariates expected to affect Culicoides abundance. RESULTS: The distance to sheep penned in the corner of the study field significantly increased the abundance level up to 200 meters away from the sheep. Spatial clustering was found to be significant but could not be explained by any known factors, and cluster locations shifted between catch nights. No significant temporal autocorrelation was detected. CAR models for both species groups identified a significant positive impact of humidity and significant negative impacts of precipitation and wind turbulence. Temperature was also found to be significant with a peak at just below 16 degrees Celcius. Surprisingly, there was a significant positive impact of wind speed. The CAR model for the Pulicaris group also identified a significant attraction to the smaller groups of sheep placed in the field. Furthermore, a large number of spatial covariates which were incorrectly found to be significant in ordinary regression models were not significant in the CAR models. The 95% C.I. on the prediction estimates ranged from 20.4% to 304.8%, underlining the difficulties of predicting the abundance of Culicoides. CONCLUSIONS: We found that significant spatial clusters of Culicoides moved around in a dynamic pattern varying between catch nights. This conforms with the modeling but was not explained by any of the tested covariates. The mean abundance within these clusters was up to 11 times higher for the Obsoletus group and 4 times higher for the Pulicaris group compared to the rest of the field
Impact of temperature, feeding preference and vaccination on Schmallenberg virus transmission in Scotland
First identified in 2011, Schmallenberg virus (SBV) is principally transmitted by Culicoides midges and
affects ruminants. Clinical presentation is typified by foetal abnormalities, but despite very high infection
rates, relatively few animals present with clinical signs. In this paper we further develop a previously
published stochastic mathematical model of SBV spread to investigate the optimal deployment of a vaccine
for SBV in Scotland, a country that has experienced only sporadic and isolated cases of SBV.We consider the
use of the vaccine under different temperatures and explore the effects of a vector preference for feeding on
cattle. We demonstrate that vaccine impact is optimised by targeting it at the high risk areas in the south of
Scotland, or vaccinating only cattle. At higher than average temperatures, and hence increased transmission
potential, the relative impact of vaccination is considerably enhanced. Vaccine impact is also enhanced if
vectors feed preferentially on cattle. These findings are of considerable importance when planning control
strategies for SBV and also have important implications for management of other arboviruses such as
Bluetongue virus. Environmental determinants and feeding preferences should be researched further to
inform development of effective control strategies
Assessing the potential for Bluetongue virus 8 to spread and vaccination strategies in Scotland
Europe has seen frequent outbreaks of Bluetongue (BT) disease since 2006, including an outbreak of BT virus serotype 8 in central France during 2015 that has continued to spread in Europe during 2016. Thus, assessing the potential for BTv-8 spread and determining the optimal deployment of vaccination is critical for contingency planning. We developed a spatially explicit mathematical model of BTv-8 spread in Scotland and explored the sensitivity of transmission to key disease spread parameters for which detailed empirical data is lacking. With parameters at mean values, there is little spread of BTv-8 in Scotland. However, under a “worst case” but still feasible scenario with parameters at the limits of their ranges and temperatures 1 °C warmer than the mean, we find extensive spread with 203,000 sheep infected given virus introduction to the south of Scotland between mid-May and mid-June. Strategically targeted vaccine interventions can greatly reduce BT spread. Specifically, despite BT having most clinical impact in sheep, we show that vaccination can have the greatest impact on reducing BTv infections in sheep when administered to cattle, which has implications for disease control policy
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