Exploring the optimal experimental setup for surface flow velocity measurements using PTV.

Advances in flow monitoring are crucial to increase our knowledge on basin hydrology and to understand the interactions between flow dynamics and infrastructures. In this context, image processing offers great potential for hydraulic monitoring, allowing acquisition of a wide range of measurements with high spatial resolution at relatively low costs. In particular, the particle tracking velocimetry (PTV) algorithm can be used to describe the dynamics of surface flow velocity in both space and time using fixed cameras or unmanned aerial systems (UASs). In this study, analyses allowed exploration of the optimal particle seeding density and frame rate in different configurations. Numerical results provided useful indications for two field experiments that have been carried out with a low-cost quadrocopter equipped with an optical camera to record RGB videos of floating tracers manually distributed over the water surface. Field measurements have been carried out using different natural tracers under diverse hydraulic and morphological conditions; PTV's processed velocities have been subsequently benchmarked with current meter measurements. The numerical results allowed rapid identification of the experimental configuration (e.g., required particle seeding density, image resolution, particle size, and frame frequency) producing flow velocity fields with high resolution in time and space with good agreement with the benchmark velocity values measured with conventional instruments.

Viral and Antibody Prevalence of Hepatitis E in European Wild Boars (Sus scrofa) and Hunters at Zoonotic Risk in the Latium Region.

Hepatitis E virus (HEV) is a member of the genus Hepevirus within the family Hepeviridae. Hepatitis E is recognized as a zoonosis, and swine and wild boars (Sus scrofa) are known reservoirs of HEV infection. The aim of this study was to investigate the presence of HEV in wild boars and hunters exposed to infection in central Italy (Latium region). During the hunting season, blood samples were collected from 228 wild boars and 20 hunters. The seroprevalence of HEV infection was determined using a commercial enzyme-linked immunosorbent assay, previously validated for use in man, pigs and wild boars. The estimated HEV seroprevalence in wild boars and in hunters was 40.7% (93/228; 95% confidence interval [CI] 34.4-47.1%) and 25% (5/20; 95% CI 6.1-43.9%), respectively. Liver samples were collected from the boars and HEV RNA was detected by nested reverse transcriptase polymerase chain reaction. Fifty-five of 164 tested wild boar liver samples (33.5%; 95% CI 26.2-40.7%) and three of 20 (15.0%; 95% CI 1.3-28.7%) tested human serum samples were positive for HEV RNA. Phylogenetic analysis of the nucleotide sequences obtained from PCR products indicated that the HEV strains present in wild boars and the human population all belonged to genotype 3, supporting the zoonotic role of wild boars in the spread of HEV infection.

Prevalence and antimicrobial susceptibility of salmonella in European wild boar (Sus scrofa); Latium Region - Italy.

The prevalence of Salmonella spp. infection was determined in 499 wild boars harvested during the 2010-2011 and 2011-2012 hunting seasons in the Latium Region of Italy. We conducted a microbiological assessment on faeces collected at slaughter and we examined serum samples for the presence of antibodies to Salmonella spp. by ELISA assay. Out of 383 serum samples examined, 255 (66.5%) were positive for Salmonella spp. antibodies. Overall, 10.8% (54/499) of the animals were positive by microbiological assessment. The Salmonellae most frequently isolated were S. enterica subsp. salamae II (24%), S. enterica subsp. Diarizonae III b (12.9%), S. enterica subsp. houtenae IV (11.1%) and S. Fischerhuette (7.4%); less common Salmonella isolates included S. Veneziana (5.5%), S. Napoli (5.5%), S. Kottbus (5.5%), S. Thompson (5.5%), S. enterica subsp. arizonae III a (3.7%), S. Toulon (3.7%), S. Burgas (1.8%), S. Tennelhone (1.8%), S. Ferruch (1.8%), S. choleraesuis (1.8%), S. Paratyphi (1.8%), S. Stanleyville (1.8%), S. Typhimurium (1.8%) and S. enterica subsp. enterica 4,5,12:1:- (1.8%). These isolates were tested against 16 antimicrobial agents and exhibited resistance to sulphonamides (92.5%), sulphonamides and thrimetroprim (14.8%), colistin (14.8%), streptomycin (18.5%), gentamycin (5.5%), tetracycline (5.5%), ceftiofur (3.7%), cefazoline (1.8%), cefotaxime (1.8%), nalidixic acid (1.8%), amoxicillin and clavulanic acid (1.8%) and ampicillin (3.7%). Our data, the first collected on this species in Italy, suggest that European wild boars are frequent carriers of antimicrobial-resistant Salmonellae and are likely involved in the transmission of antimicrobial resistance throughout the environment.

Secondary metabolites: applications on cultural heritage.

Biological sciences and related bio-technology play a very important role in research projects concerning protection and preservation of cultural heritage for future generations. In this work secondary metabolites of Burkholderia gladioli pv. agaricicola (Bga) ICMP 11096 strain and crude extract of glycoalkaloids from Solanaceae plants, were tested against a panel of microorganisms isolated from calcarenite stones of two historical bridges located in Potenza and in Campomaggiore (Southern Italy). The isolated bacteria belong to Bacillus cereus and Arthrobacter agilis species, while fungi belong to Aspergillus, Penicillium, Coprinellus, Fusarium, Rhizoctonio and Stemphylium genera. Bga broth (unfiltered) and glycoalkaloids extracts were able to inhibit the growth of all bacterial isolates. Bga culture was active against fungal colonies, while Solanaceae extract exerted bio-activity against Fusarium and Rhizoctonia genera.

Circular dichroism and molecular modeling of the E. coli TolA periplasmic domains.

Colicins are killer proteins that use envelope proteins from the outer and the inner membranes to reach their cellular target in susceptible cells of Escherichia coli. Each group A colicin uses a combination of Tol proteins to cross the outer membrane of gram-negative bacteria and to exert their killing activity. The TolA protein, necessary for the import of all the group A colicins, is a 421-amino acid residue protein composed of three domains (TolAI, TolAII, and TolAIII). TolAIII interacts with the N-terminal domain of colicin A (AT1). Analytical ultracentrifugation reveals that TolAII and TolAIII are monomer structures, TolAII has an elongated structure, and TolAIII is rather globular. Circular dichroism (CD) spectra were done with TolAII-III, TolAII, TolAIII, AT1, and the AT1-TolAII-III complex. TolA CD spectra reveal the presence of alpha-helix structure in aqueous solution and the intensity of the a-helix signal is the highest with TolAII. Few structural changes are observed with the complex AT1-TolAII-III. Molecular modeling was done for TolAII-III, taking into account CD and ultracentrifugation data and show that domain II can adopt a barrel structure made of three twisted alpha-helices similar to coiled coil helices while domain III can adopt a globular structure.

Thermal denaturation of bacterial and bovine dihydrofolate reductases and their complexes with NADPH, trimethoprim and methotrexate.

Scanning microcalorimetry was used for the study of thermal denaturation of E.coli and bovine liver dihydrofolate reductases (cDHFR and bDHFR, respectively) and their complexes with NADPH, trimethoprim (TMP) and methotrexate (MTX) at pH 6.8. It was shown that the denaturation temperature of bDHFR is 7.2 degrees C less than that of cDHFR and that ionic strength is equally important for the thermostability and cooperativity of the denaturation process of the two proteins. Binding of antifolate compounds significantly stabilizes DHFR against heat denaturation. The stabilizing effect and the transition cooperativity depend on the nature of the inhibitor, the presence of NADPH and the origin of the enzyme. The dependence of calorimetric denaturation enthalpy (calculated per gram of protein) on denaturation temperature for DHFRs, their complexes with NADPH and binary/ternary complexes with TMP/MTX fits to the same straight line with the slope of 0.66 J/Kg. This relatively high value indicates an essential role of hydrophobic contacts in the stabilization of DHFR structure. The change of denaturation temperatures in binary complexes with MTX/TMP (in comparison with the free enzymes) is as much as 14.2 degrees C/8.5 degrees C and 13.3 degrees C/3.2 degrees C for cDHFR and bDHFR, respectively. The same change in ternary complexes with MTX/TMP is much more pronounced and equals to 21.9 degrees C/16.8 degrees C and 29.0 degrees C/16.4 degrees C. The vast difference of binary and ternary complexes thermostability demonstrates the important role of cofactor in the stabilization of enzyme. Moving from binary to ternary systems causes a significant increase in denaturation temperatures, even when corresponding association constants do not change (cDHFR binary/ternary complexes with MTX) or increases very slightly (bDHFR binary/ternary complexes with TMP). In all other cases the increase of denaturation temperature for each protein in complex with ligands correlates with the association constant for the corresponding complex.

Thermodynamic study of dihydrofolate reductase inhibitor selectivity.

The thermodynamic parameters of the binding of some folate analogues (methotrexate, trimetrexate and trimethoprim) to dihydrofolate reductases from different species have been measured with a flow microcalorimetric method at 37 degrees C. In the absence of NADPH, the three inhibitors exhibited a higher affinity for E. coli DHFR than for vertebrate DHFRs. This selectivity in favor of bacterial DHFR is entropy driven and is correlated with a weaker conformational change for bacterial DHFR than for vertebrate DHFRs, and with additional hydrophobic contacts, provided by this enzyme to the ligands. In presence of NADPH, as reported in the literature, trimetoprim shows a high selectivity in favor of bacterial DHFR, contrarily to methotrexate and trimetrexate, whose affinities are elevated and highly similar for mammalian and bacterial enzymes. The positive cooperative effect of NADPH, which has an enthalpic origin, fluctuates widely with inhibitor structure and with enzyme species. For trimethoprim, the cooperative effect is much more pronounced for bacterial DHFR than for vertebrate DHFRs. But the role of NADPH is not to induce a selectivity: it only increases the selectivity that trimethoprim already presented in absence of NADPH. Inversely, for methotrexate and trimetrexate, the cooperative effect is stronger for vertebrate enzymes than for the bacterial enzyme, and thus, NADPH cancels the selectivity the two antifolic compounds had, in the absence of NADPH, for the bacterial enzyme.

Antenatal and intrapartum factors associated with the occurrence of seizures in term infant.

To identify antenatal and intrapartum risk factors associated with seizures in term newborns, 40 infants who had seizures within 72 hours of birth were compared with 400 controls using logistic regression analysis. The risk of seizure in the term newborn was approximately one per 1000 in the population studied. The logistic regression model identified a group of infants in whom the risk of seizure was approximately one per 100. The risk factors included in the model were antepartum anemia, antepartum bleeding, asthma, meconium-stained amniotic fluid, presentation other than occiput anterior, fetal distress, and shoulder dystocia. Consistent with other studies, our analysis confirmed a strong association between seizures and factors that increase the risk of fetal asphyxia.

Stereochemical considerations and the antiinflammatory activity of 6-amino-6,7,8,9-tetrahydro-5H-benzocyclohepten-5-ols and related derivatives.

The antiinflammatory activity of a series of 6-amino-6,7,8,9-tetrahydro-5H-benzocyclohepten-5-ols and related derivatives was examined using the reverse passive Arthus reaction (RPAR). The antiinflammatory activity of these compounds was markedly influenced by the stereochemistry of the amino alcohol moiety. The threo diastereomer exhibited activity in the RPAR, while the erythro diastereomer was devoid of any significant antiinflammatory activity. The antiinflammatory activity of the amino alcohols was also significantly influenced by the position and nature of the aromatic substituent. Latentiation of the amino alcohol function resulted in analogues exhibiting antiinflammatory activity equivalent to their amino alcohol precursors. Masking the amino alcohol function as a more stable derivative led to analogues exhibiting an antiinflammatory profile unique to their structural class.