Longitudinal Variability in Hydrochemistry and Zooplankton Community of a Large River: A Lagrangian‐Based Approach

The variability in water quality and zooplankton community structure during downstream transport was investigated in the Po river (Italy) using for the first time a Lagrangian sampling approach. Two surveys were conducted, one in spring under relatively high discharge levels, and one at low flows in summer. Twelve stations along a 332‐km stretch of the river’s lowland reach and four major tributaries were sampled. A hydrodynamic modelling system was used to determine water transport time along the river, with a satisfying fit between simulated and observed discharge values. No clear downstream trend in phosphorus and nitrogen concentrations was found. Conversely, a marked longitudinal decrease in dissolved silica supports the hypothesis of increasing downstream silica limitation during the phytoplankton growing season.In spring, at low residence time, no apparent plankton growth was observed during downstream transport. In summer, higher temperatures and lower turbulence and turbidity associated with longer residence time stimulated algal growth and in‐stream reproduction of fast‐growing rotifer taxa, with the gradual downstream development of a truly potamal assemblage and the increase of the ratio of euplanktonic to littoral/epibenthic rotifer taxa. Crustacean zooplankton density was generally low. The importance of biotic interactions within the zooplankton in driving community abundance and composition appeared to increase in the downstream direction, paralleled by a decrease in the influence of physical forcing. Tributary influence was especially evident where severe anthropogenic alterations of river hydrology and trophic status resulted in enhanced plankton growth, ultimately affecting zooplankton structure in the main river. Copyright © 2016 John Wiley & Sons, Ltd.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/134064/1/rra3028.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/134064/2/rra3028_am.pd

Antibacterial effects of two synthetic peptides against Enterococcus faecalis biofilms: A preliminary in vitro study

Aim: Current endodontic techniques are unable to fully eradicate intracanal bacteria. Thus, new agents that effectively eliminate endodontic pathogens are needed. The aim of this study was to assess the antibacterial properties of two synthetic peptides, namely KP and L18R, against planktonic cells and biofilms of the endodontic pathogen Enterococcus faecalis. Methodology: KP and L18R bactericidal activity against E. faecalis ATCC 29212 was evaluated by colony forming unit assays and the half maximal effective concentration (EC50) was calculated. The effect of peptides on E. faecalis biofilm formation onto polystyrene plates was also assessed by the crystal violet assay. Confocal laser scanning microscopy (CLSM) analysis was carried out to compare the effects of KP, L18R and a Ca(OH)2 saturated solution in an in vitro model of dental infection consisting in 2-day-old E. faecalis biofilms grown on hydroxyapatite disks. Results: Both KP and L18R showed strong bactericidal activity against planktonic E. faecalis. L18R proved to be 10-folds more ef fective than KP (KP and L18R EC50 values=4.520×10-6 M and 3.624×10-7 M, respectively). Peptides inhibited E. faecalis biofilm formation in a dose-dependent manner and L18R resulted more effectivethan KP. CLSM images showed that Ca(OH)2, KP and L18R remarkably impaired E. faecal is biof i lms pre -grown on hydroxyapatite. Conclusions: KP and L18R effectively inhibited E. faecalis, both in planktonic and biofilm form. L18R demonstrated a more potent antibacterial activity than KP. These preliminary results suggest that antimicrobial peptides may represent a promising new strategy for endodontic infection control

Activity of two antimicrobial peptides against Enterococcus faecalis in a model of biofilm-mediated endodontic infection

Enterococcus faecalis is a common cause of biofilm-associated opportunistic infections, which are often difficult to treat. The formation of E. faecalis biofilms on the dentinal walls of the root canal is frequently the cause of endodontic treatment failure and secondary apical periodontitis. In a preliminary work, two recognized antifungal peptides, KP and L18R, showed antibacterial activity against planktonic E. faecalis cells at micromolar concentrations. Moreover, L18R proved to reduce the biomass in the early stage of E. faecalis biofilm development on polystyrene plates, while a qualitative biofilm inhibition was demonstrated on hydroxyapatite disks by confocal laser scanning microscopy (CLSM). The aim of this study was to better characterize the effect of both peptides on E. faecalis biofilm. A reduction in metabolic activity after peptide treatment was detected by Al-amar Blue assay, while a remarkable impairment in the architecture of E. faecalis biofilms on hy-droxyapatite disks, along with a significant reduction in viable bacteria, was caused mostly by L18R, as assessed by CLSM and scanning electron microscopy. The lack of cytotoxicity of the investigated peptides against L929 murine fibroblasts was also determined. Obtained results suggest L18R as a promising candidate for the development of new strategies for endodontic infection control

Negative serology of Fasciola hepatica infection in patients with liver cancer in Peru: A preliminary report

Introduction: The etiology of several hepatocellular carcinoma (HCC) cases remains largely unknown. Although Fasciola hepatica has been associated with liver fibrosis in Latin America, it has not yet been associated with HCC. This study aimed to determine the existence of specific IgG antibodies against F. hepatica in the serum samples of HCC patients. Methods: In total, 13 serum samples from 13 HCC patients were screened using Fas2-ELISA. Results: Fas2-ELISA demonstrated negative results in all HCC patients included in this study. Conclusions: The pre-existence of F. hepatica infection in HCC patients needs to be further investigated in epidemiological and experimental studies

label free discrimination of cells undergoing apoptosis by hyperspectral confocual reflectance imaging

Among the optical techniques used for exploring the properties of cells and tissues, those based on hyperspectral label-free analysis are particularly interesting due to their non-invasive character and their ability to fast collect a huge number of information on the different sample constituents and their spatial distribution. Here we present results obtained with a novel hyperspectral reflectance confocal microscope of label-free discrimination of cells undergoing apoptosis. Our data, analyzed by means of a powerful statistical method, enable to obtain information on the biological status at a single cell level through the local measurement of reflectivity. Furthermore, an optical model of the local dielectric response gives an additional insight of the parameters linking the optical responsivity to the biological status

Development of reverse genetics systems for infectious bursal disease virus by yeast-based homologous recombination.

Projeto/Plano de Ação: 05.11.10.200-04

First determination of the one-proton induced Non-Mesonic Weak Decay width of p-shell {\Lambda}-Hypernuclei

Previous studies of proton and neutron spectra from Non-Mesonic Weak Decay of eight Lambda-Hypernuclei (A = 5-16) have been revisited. New values of the ratio of the two-nucleon and the one-proton induced decay widths, Gamma_2N/Gamma_p, are obtained from single proton spectra, Gamma_2N/Gamma_p = 0.50 +/- 0.24, and from neutron and proton coincidence spectra, Gamma_2N/Gamma_p = 0.36 +/- 0.14stat +0.05sys -0.04sys , in full agreement with previously published ones. With these values, a method is developed to extract the one-proton induced decay width in units of the free Lambda decay width, Gamma_p/Gamma_Lambda, without resorting to Intra Nuclear Cascade models but by exploiting only experimental data, under the assumption of a linear dependence on A of the Final State Interaction contribution. This is the first systematic determination ever done and it agrees within the errors with recent theoretical calculations.Comment: 16 pages, 3 figures, 2 table

A model to explain angular distributions of J/ψJ/\psi and ψ(2S)\psi(2S) decays into ΛΛ‾\Lambda\overline{\Lambda} and Σ0Σ‾0\Sigma^0\overline{\Sigma}^0

BESIII data show a particular angular distribution for the decay of the $J/\psi$ and $\psi(2S)$ mesons into the hyperons $\Lambda\overline{\Lambda}$ and $\Sigma^0\overline{\Sigma}^0$. More in details the angular distribution of the decay $\psi(2S) \to \Sigma^0\overline{\Sigma}^0$ exhibits an opposite trend with respect to that of the other three channels: $J/\psi \to \Lambda\overline{\Lambda}$, $J/\psi \to \Sigma^0\overline{\Sigma}^0$ and $\psi(2S) \to \Lambda\overline{\Lambda}$. We define a model to explain the origin of this phenomenon.Comment: 6 pages, 7 figures, to be published in Chinese Physics

Ig Glycosylation in Ulcerative Colitis: It’s Time for New Biomarkers

Background: Ulcerative colitis (UC) is a chronic relapsing disease, which needs a continue monitoring, especially during biological therapies. An increasing number of patients is treated with anti-Tumor Necrosis factor (TNF) drugs, and current research is focalized to identify biomarkers able to monitor the disease and to predict therapeutic outcome. Methods: We enrolled consecutive UC patients treated with anti-TNF, naïve to biologic drugs. Therapeutic outcome was evaluated after 54 weeks of treatment in terms of clinical remission (Partial Mayo Score -PMS- <2) and mucosal healing (Mayo Endoscopic Score <2). On serum samples collected at baseline and after 54 weeks of treatment, a Lectin-based ELISA assay was performed, and specific glycosylation patterns were evaluated by biotin-labelled lectins. We have also collected 21 healthy controls (NHS) samples, age and sex-matched. Results: Out of 44 UC patients enrolled, 22 achieved clinical remission and mucosal healing after 54 weeks. At baseline, when Protein A was used as coating, UC patients non-responders showed a reduced reactivity to Jacalin (JAC) in comparison with NHS (p = 0.04). After one year of treatment, a decrease in JAC binding was seen only in responders, in comparison with baseline (p = 0.04). When JAC binding was tested selecting IgG by means of Fab anti-IgG Fab, UC patients displayed an increased reactivity after anti-TNF therapy (p < 0,0001 vs controls). At baseline, PMS inversely correlates with JAC binding when Fab anti-IgG Fab was used in solid phase (r2 = 0,2211; p = 0,0033). Patients with higher PMS at baseline (PMS ≥5) presented lower binding capacity for JAC in comparison with NHS and with lower PMS patients (p = 0,0135 and p = 0,0089, respectively). Conclusion: Ig glycosylation was correlated with clinical and endoscopic activity in patients with UC. JAC protein A-selected Ig showed a possible role in predicting therapeutic effectiveness. If these data would be confirmed, Ig glycosylation could be used as biomarker in UC