193 research outputs found
Systematic grid-wise radon concentration measurements and first radon map in Cyprus
A systematic study of the indoor airborne radon concentration in the central
part of the Nicosia district was conducted, using high-sensitivity active radon
portable detectors of the type "RADIM3A". From a total of 108 measurements in
54 grids of 1 km^2 area each, the overall mean value is 20.6 \pm 13.2 Bq m^-3
(A.M.\pm S.D.). That is almost twice less than the corresponding average
worldwide value. The radon concentration levels in drinking water were also
measured in 24 sites of the residential district, using the high-sensitivity
radon detector of the type "RADIM3W". The mean value obtained from these
measurements is 243.8 \pm 224.8 mBq L^-1, which is relatively low compared to
the corresponding internationally accepted level. The associated annual
effective dose rates to each measurement were also calculated and compared to
the corresponding worldwide values. From the geographical coordinates of the
measuring sites and the corresponding radon concentration values, the digital
radon map of the central part of the Nicosia district was constructed for the
first time, by means of the ArcMap software package.Comment: 21 pages including 2 tables and 8 figure
HARMONIA: strategy of an integrated resilience assessment platform (IRAP) with available tools and geospatial services
The huge amount of the available data nowadays has raised some major challenges which are related to the storage, fusion, structure, streaming and processing of these data. In this paper, we present the development of a holistic framework, entitled HARMONIA, that encompasses State-of-The-Art solutions for the emerging issues related to Climate Change, natural and/or man-made hazards and urban/peri-urban risks. The Horizon 2020 HARMONIA project is developing an Integrated Resilience Assessment Platform (IRAP) which plans to provide targeted services for different groups of end-users. In particular, it will actively support urban decision-makers in strategic decisions and planning and citizens in facing daily effects and risks of Climate Change. Additionally, the platform will be a place to interconnect cities which end up facing similar Climate Change effects. HARMONIA IRAP leverages cuttingedge technologies (i.e., explainable Artificial Intelligence, Data Mining, multi-criteria analysis, dynamic programming) and services (ie., Virtual Machines, Containers) in order to provide solutions considering the complexity and diversity of extreme earth and non-earth data. In addition, this platform includes a Decision Support System providing early-warning feedback and recommendations to the end-users. In this way the HARMONIA IRAP design tends to address these challenges by offering the corresponding dynamic, scalable and robust mechanisms with the aim to provide useful integrated tools for the related users. Datacubes architecture, which is a major part of the IRAP, offers the opportunity to investigate more sophisticated correlations among the data and provide a more tangible representation of the extracted information
Increased cortical neuronal responses to NMDA and improved attentional set-shifting performance in rats following prebiotic (B-GOS) ingestion.
We have previously shown that prebiotics (dietary fibres that augment the growth of indigenous beneficial gut bacteria) such as Bimuno galacto-oligosaccharides (B-GOS), increased N-methyl-D-aspartate (NMDA) receptor levels in the rat brain. The current investigation examined the functional correlates of these changes in B-GOS-fed rats by measuring cortical neuronal responses to NMDA using in vivo NMDA micro-iontophoresis electrophysiology, and performance in the attentional set-shifting task. Adult male rats were supplemented with B-GOS in the drinking water 3 weeks prior to in vivo iontophoresis or behavioural testing. Cortical neuronal responses to NMDA iontophoresis, were greater (+30%) in B-GOS administered rats compared to non-supplemented controls. The intake of B-GOS also partially hindered the reduction of NMDA responses by the glycine site antagonist, HA-966. In the attentional set-shifting task, B-GOS -fed rats shifted from an intra-dimensional to an extra-dimensional set in fewer trials than controls, thereby indicating greater cognitive flexibility. An initial exploration into the mechanisms revealed that rats ingesting B-GOS had increased levels of plasma acetate, and cortical GluN2B subunits and Acetyl Co-A Carboxylase mRNA. These changes were also observed in rats fed daily for 3 weeks with glyceryl triacetate, though unlike B-GOS, cortical histone deacetylase (HDAC1, HDAC2) mRNAs were also increased which suggested an additional epigenetic action of direct acetate supplementation. Our data demonstrate that a pro-cognitive effect of B-GOS intake in rats is associated with an increase in cortical NMDA receptor function, but the role of circulating acetate derived from gut bacterial fermentation of this prebiotic requires further investigation
The contrasted phytoplankton dynamics across a frontal system in the southwestern Mediterranean Sea
Numerical simulations have shown that finescale structures such as fronts are often suitable places for the generation of vertical velocities,
transporting subsurface nutrients to the euphotic zone and thus modulating phytoplankton abundance and community structure. In these structures,
direct in situ estimations of the phytoplankton growth rates are rare; although difficult to obtain, they provide precious information on the
ecosystem functioning. Here, we consider the case of a front separating two water masses characterized by several phytoplankton groups with
different abundances in the southwestern Mediterranean Sea. In order to estimate possible differences in growth rates, we measured the
phytoplankton diurnal cycle in these two water masses as identified by an adaptive and Lagrangian sampling strategy. A size-structured population
model was then applied to these data to estimate the growth and loss rates for each phytoplankton group identified by flow cytometry, showing that
these two population parameters are significantly different on the two sides of the front and consistent with the relative abundances. Our results
introduce a general method for estimating growth rates at frontal systems, paving the way for in situ exploration of finescale biophysical
interactions.</p
UV spectrophotometry method for the monitoring of galacto-oligosaccharides production
Monitoring the industrial production of galacto-oligosaccharides (GOS) requires a fast and accurate
methodology able to quantify, in real time, the substrate level and the product yield. In this work, a simple,
fast and inexpensive UV spectrophotometric method, together with partial least squares regression
(PLS) and artificial neural networks (ANN), was applied to simultaneously estimate the products (GOS)
and the substrate (lactose) concentrations in fermentation samples. The selected multiple models were
trained and their prediction abilities evaluated by cross-validation and external validation being the
results obtained compared with HPLC measurements. ANN models, generated from absorbance spectra
data of the fermentation samples, gave, in general, the best performance being able to accurately and precisely
predict lactose and total GOS levels, with standard error of prediction lower than 13 g kg 1 and
coefficient of determination for the external validation set of 0.93â0.94, showing residual predictive deviations
higher than five, whereas lower precision was obtained with the multiple model generated with
PLS. The results obtained show that UV spectrophotometry allowed an accurate and non-destructive
determination of sugars in fermentation samples and could be used as a fast alternative method for monitoring
GOS production.Fundação para a CiĂȘncia e a Tecnologia (FCT) - Bolsa de doutouramento SFRH/BDE/15510/2004AgĂȘncia da Inovação â Programa IDEIA (Potugal
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Effects of orange juice formulation on prebiotic functionality using an in vitro colonic model sytem
A three-stage continuous fermentative colonic model system was used to monitor in vitro the effect of different orange juice formulations on prebiotic activity. Three different juices with and without Bimuno, a GOS mixture containing galactooligosaccharides (B-GOS) were assessed in terms of their ability to induce a bifidogenic microbiota. The recipe development was based on incorporating 2.75g B-GOS into a 250 ml serving of juice (65°Brix of concentrate juice). Alongside the production of B-GOS juice, a control juice - orange juice without any additional Bimuno and a positive control juice, containing all the components of Bimuno (glucose, galactose and lactose) in the same relative proportions with the exception of B-GOS were developed. Ion Exchange Chromotography analysis was used to test the maintenance of bimuno components after the production process. Data showed that sterilisation had no significant effect on concentration of B-GOS and simple sugars. The three juice formulations were digested under conditions resembling the gastric and small intestinal environments. Main bacterial groups of the faecal microbiota were evaluated throughout the colonic model study using 16S rRNA-based fluorescence in situ hybridization (FISH). Potential effects of supplementation of the juices on microbial metabolism were studied measuring short chain fatty acids (SCFAs) using gas chromatography. Furthermore, B-GOS juices showed positive modulations of the microbiota composition and metabolic activity. In particular, numbers of faecal bifidobacteria and lactobacilli were significantly higher when B-GOS juice was fermented compared to controls. Furthermore, fermentation of B-GOS juice resulted in an increase in Roseburia subcluster and concomitantly increased butyrate production, which is of potential benefit to the host. In conclusion, this study has shown B-GOS within orange juice can have a beneficial effect on the fecal microbiota
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CLSM method for the dynamic observation of pH change within polymer matrices for oral delivery
If acid-sensitive drugs or cells are administered orally, there is often a reduction in efficacy associated with gastric passage. Formulation into a polymer matrix is a potential method to improve their stability. The visualization of pH within these materials may help better understand the action of these polymer systems and allow comparison of different formulations. We herein describe the development of a novel confocal laser-scanning microscopy (CLSM) method for visualizing pH changes within polymer matrices and demonstrate its applicability to an enteric formulation based on chitosan-coated alginate gels. The system in question is first shown to protect an acid-sensitive bacterial strain to low pH, before being studied by our technique. Prior to this study, it has been claimed that protection by these materials is a result of buffering, but this has not been demonstrated. The visualization of pH within these matrices during exposure to a pH 2.0 simulated gastric solution showed an encroachment of acid from the periphery of the capsule, and a persistence of pHs above 2.0 within the matrix. This implies that the protective effect of the alginate-chitosan matrices is most likely due to a combination of buffering of acid as it enters the polymer matrix and the slowing of acid penetration
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