Intermittent statistics and stochastic modelling of low and high Re compressible jets

International audienceIn this work, we studied the intermittent statistics of pressure fluctuations in the near field of compressible subsonic single stream jets. The analysis has been performed considering data from numerical simulations of two isothermal jets having the same Mach number, M=0.9, and two different Reynolds number (3,125 and 100,000). Pressure fluctuations were measured by virtual probes located in different positions in the radial and axial directions. Intermittent events are extracted through appropriate wavelet-based indicators and two random variables are analyzed, namely the intermittent time Δ , that is the time delay between two successive events, and the energy amplitude A. Their statistics are computed with the scope of adressing the stochastic model proposed by Camussi et al. [1] that was settled up on the basis of experimental data. The present analysis extends the validity of the model to very low Reynolds number conditions and to the statistics of the 0 ℎ azimuthal mode of the pressure fluctuations that exhibit a relevant degree of intermittency around the Kelvin-Helmholtz frequency

Presence of Escherichia coli O157, Salmonella spp., and Listeria monocytogenes in Raw Ovine Milk Destined for Cheese Production and Evaluation of the Equivalence Between the Analytical Methods Applied

Italy is one of the main producers and exporters of cheese made from unpasteurized sheep milk. Since raw milk and its derived products are known sources of human infections, cheese produced from raw sheep milk could pose a microbiological threat to public health. Hence, the objectives of the study were: to characterize the potential risk of the presence of pathogens Escherichia coli O157, Listeria monocytogenes, and Salmonella in raw ovine milk destined for cheese production obtained from all the sheep farms (n = 24) in the Marches region (Central Italy) that directly transform raw milk into cheeses and to evaluate the equivalence between the analytical methods applied. A three-step molecular method (simultaneous culture enrichment, species-specific DNA magnetic isolation, and multiplex real-time polymerase chain reaction) was used for milk (n = 143) and cheese (n = 5) analysis over a 3- year period. L. monocytogenes was not detected on any of the farms, while E. coli O157 was found on three farms, although only using the molecular method. Four farms tested positive for Salmonella spp., and Salmonella enterica subsp. diarizonae serovar 61:k:1,5,7 was isolated in one of those cases. This information highlights the need to develop preventative measures to guarantee a high level of consumer safety for this specific product line, and the molecular method could be a time-saving and sensitive tool to be used in routine diagnosis

Multifunctional double-negative T cells in sooty mangabeys mediate T-helper functions irrespective of SIV infection.

Studying SIV infection of natural host monkey species, such as sooty mangabeys, has provided insights into the immune changes associated with these nonprogressive infections. Mangabeys maintain immune health despite high viremia or the dramatic CD4 T cell depletion that can occur following multitropic SIV infection. Here we evaluate double-negative (DN)(CD3+CD4-CD8-) T cells that are resistant to SIV infection due to a lack of CD4 surface expression, for their potential to fulfill a role as helper T cells. We first determined that DN T cells are polyclonal and predominantly exhibit an effector memory phenotype (CD95+CD62L-). Microarray analysis of TCR (anti-CD3/CD28) stimulated DN T cells indicated that these cells are multifunctional and upregulate genes with marked similarity to CD4 T cells, such as immune genes associated with Th1 (IFNγ), Th2 (IL4, IL5, IL13, CD40L), Th17 (IL17, IL22) and TFH (IL21, ICOS, IL6) function, chemokines such as CXCL9 and CXCL10 and transcription factors known to be actively regulated in CD4 T cells. Multifunctional T-helper cell responses were maintained in DN T cells from uninfected and SIV infected mangabeys and persisted in mangabeys exhibiting SIV mediated CD4 loss. Interestingly, TCR stimulation of DN T cells from SIV infected mangabeys results in a decreased upregulation of IFNγ and increased IL5 and IL13 expression compared to uninfected mangabeys. Evaluation of proliferative capacity of DN T cells in vivo (BrDU labeling) indicated that these cells maintain their ability to proliferate despite SIV infection, and express the homeostatic cytokine receptors CD25 (IL2 receptor) and CD127 (IL7 receptor). This study identifies the potential for a CD4-negative T cell subset that is refractory to SIV infection to perform T-helper functions in mangabeys and suggests that immune therapeutics designed to increase DN T cell function during HIV infection may have beneficial effects for the host immune system

Characterization of naproxen-polymer conjugates for drug-delivery

The synthesis and the characterization of three new naproxen decorated polymers are described. A versatile and general approach is employed to link the drug to polymers, affording the derivatives with a very high degree of purity. The release of the drug from the conjugates proved to be exceptionally slow, even in acidic aqueous media, and the kinetic of the process seems to be triggered by their solubility in water. On the other hand, the interesting outcome of the first ex vivo drug release experiments on human blood samples makes this preliminary study valuable for future investigations on the use of these polymeric prodrugs in in vivo treatment of inflammatory states

IL-17 producing cell function is higher in colorectum than blood in uninfected RMs.

<p><b>(A)</b> Comparison between cytokine profiles of Th17, Th22, and Th17/Th22 cells in PBMC and RB in uninfected RMs (d. -20 p.i.). Cytokine profiles were generated for each cell population by SPICE program v. 5.33, and were calculated by Flowjo Boolean gating. <b>(B)</b> Functional scores were compared for all three subsets between PBMC and RB. Functional scores represent average number of cytokines produced per individual cell (see <a href="http://www.plospathogens.org/article/info:doi/10.1371/journal.ppat.1005412#sec011" target="_blank">Methods</a>). Averaged data are presented as means ± SEM.</p

ART treatment is insufficient for full restoration of cell subset levels and function.

<p><b>(A-C)</b> Longitudinal functional scores of Th17, Th22, and Th17/Th22 cells in RB at pre-infection (d. -20 p.i.), pre-ART (d. 58 p.i.), and throughout ART (d. 84 p.i. through d. 256 p.i.). Data are presented as box and whisker plots, with the median functional score plotted in between the 25% and 75% quartiles. Dotted line marks time of SIV infection and shaded gray box represents time of ART treatment. ART significantly increased all three subsets’ functional scores, but did not bring Th17 cell function back to pre-infection level. <b>(D)</b> Levels of subsets (as percentages of total CD4⁺ T-cell populations) in RB during ART remain significantly lower than pre-infection. <b>(E)</b> Longitudinal cumulative subset scores, calculated by multiplying cell frequencies and functional scores, showed the inability of ART to fully restore the levels and function of Th17, Th22, and Th17/Th22 cells. Th17 cells marked as red, Th22 cells marked as blue, and Th17/Th22 cells marked as green. Averaged data are presented as means ± SEM.</p

SIV infection severely ablates intestinal IL-17 and IL-22 producing cell function and levels.

<p><b>(A)</b> Comparison between PBMC and RB Th17, Th22, and Th17/Th22 cell cytokine profiles at pre-infection (d.-20 p.i.) vs SIV infection (d. 58 p.i.). While all RB cytokine profiles significantly changed after SIV infection, the blood cytokine profiles remained unchanged. <b>(B)</b> No changes in functional score in PBMC after SIV infection. <b>(C)</b> In all three subsets, colorectal functional scores drastically decreased after SIV infection. Th17 cells marked as red, Th22 cells marked as blue, and Th17/Th22 cells marked as green. Averaged data are presented as means ± SEM.</p

Loss of Th17, Th22, and Th17/Th22 cell function correlates with colorectal immune activation, soluble markers of inflammation, and levels of CD4⁺ T-cells.

<p>Correlations between Th17, Th22, and Th17/Th22 cell function and plasma viral loads (copies viral RNA per mL of plasma) <b>(A,B)</b>, absolute number of CD4⁺ T-cells <b>(C)</b>, levels of activated colorectal (HLA-DR⁺CD38⁺) CD4⁺ T-cells <b>(D,E)</b>, the level of proliferating (Ki-67⁺) RB CD4⁺ T-cells <b>(F)</b>, as well as soluble markers of inflammation sCD14 and sCD163 <b>(G, H)</b>. Pearson product-moment correlation coefficients were measured for all plots except for 7A, which required Spearman’s rank correlation coefficient.</p

Levels of Th17, Th22, and Th17/Th22 are more drastically depleted by SIV infection in RB than PBMC.

<p>Comparison of frequencies (measured as percentages of total CD4⁺ T-cell populations) of circulating <b>(A)</b> and colorectal <b>(B)</b> Th17 (red), Th22 (blue), and Th17/Th22 (green) cells before (d.-20 p.i.) and after (d. 58 p.i.) SIV infection. Averaged data are presented as means ± SEM.</p

Loss of Th17, Th22, and Th17/Th22 cell function and levels are correlates and predictors of SIV persistence.

<p>Correlations between colorectal SIV-DNA content at late-ART (d. 256 p.i.) and IL-17 and IL-22 producing cell function and levels at both ART (<b>A-C</b>) and pre-ART infection (d. 58 p.i). <b>(D,E)</b>. Levels and function of the three subsets at pre-ART and after ART interruption additionally correlated with levels of blood DNA levels after ART interruption (d. 440 p.i.) <b>(F-I)</b>. Pearson product-moment correlation coefficients were measured for all plots except for 8E, which required Spearman’s rank correlation coefficient.</p