The extended structure of the dwarf irregular galaxies Sextans A and Sextans B. Signatures of tidal distortion in the outskirts of the Local Group

We present a detailed study of the stellar and HI structure of the dwarf irregular galaxies SextansA and SextansB, members of the NGC3109 association. We use newly obtained deep (r~26.5) and wide field g,r photometry to extend the Surface Brightness (SB) profiles of the two galaxies down to mu_V~ 31.0 mag/arcsec^2. We find that both galaxies are significantly more extended than what previously traced with surface photometry, out to ~4 kpc from their centers along their major axis. Older stars are found to have more extended distribution with respect to younger populations. We obtain the first estimate of the mean metallicity for the old stars in SexB, from the color distribution of the Red Giant Branch, =-1.6. The SB profiles show significant changes of slope and cannot be fitted with a single Sersic model. Both galaxies have HI discs as massive as their respective stellar components. In both cases the HI discs display solid-body rotation with maximum amplitude of ~50 km/s (albeit with significant uncertainty due to the poorly constrained inclination), implying a dynamical mass ~10^{9}~M_sun, a mass-to-light ratio M/L_V~25 and a dark-to-barionic mass ratio of ~10. The distribution of the stellar components is more extended than the gaseous disc in both galaxies. We find that the main, approximately round-shaped, stellar body of Sex~A is surrounded by an elongated low-SB stellar halo that can be interpreted as a tidal tail, similar to that found in another member of the same association (Antlia). We discuss these, as well as other evidences of tidal disturbance, in the framework of a past passage of the NGC3109 association close to the Milky Way, that has been hypothesized by several authors and is also supported by the recently discovered filamentary configuration of the association itself.Comment: Accepted for publication by A&A. PdfLateX, 16 pages, 11 figures, 2 appendice

Thermally-induced lactosylation of whey proteins: Identification and synthesis of lactosylated β-lactoglobulin epitope

The high temperatures used in the production of milk may induce modifications in proteins structure. Due to occurrence of the Maillard reaction, lactose binds lysine residues in proteins, affecting the nutritional value. Milk is also an important source of allergenic proteins (i.e., caseins, β-lactoglobulin and α-lactalbumin). Thus, this modification may also affect the allergenicity of these proteins. Focusing on milk whey proteins, a screening on different Ultra High Temperatures (UHT) and pasteurized milk samples was performed to identify lactosylation sites, in particular in protein known epitopes, and to verify the correlation between lactosylation and the harshness of the treatment. Whey proteins were extracted from milk samples after caseins precipitations at pH 4.6 and, after chymotryptic and tryptic in solution digestion, peptides were analysed by UPLC-MS and LTQ-Orbitrap. Results show the presence of lactosylated lysine residues in several known epitopes. Then, a β-lactoglobulin epitope was selected and synthesized by solid phase synthesis followed by in solution lactosylation, obtaining high reaction yields and purities. The synthesis of lactosylated allergenic epitopes, described here for the first time, is a useful tool for further studies on the technological impacts on food allergenicity

Culverted rivers in the historic center of Genoa (Italy) as an emblematic case of human pressure and fluvial landscape changes

The city of Genoa is internationally known its the recurrent floods, mainly related to the Bisagno River. The high risk is linked to meteo-hydrological hazard and to the urbanisation in hazardous areas and consequently to the high exposure of risk elements. The present research concerns the hydrographic network that characterises the historical center of Genoa, i.e. the natural amphitheatre bordering the Polcevera valley to the W and the Bisagno valley to the E. In this area of just 8.5 km2 there are eight catchments ranging from 0.49 km2 to 2.36 km2 in size: from W to E we recognise the basins of the San Bartolomeo, San Lazzaro, San Teodoro, Lagaccio, Sant'Ugo, Carbonara, Sant'Anna and Torbido streams. These watercourses have been subject to anthropic modifications since the Middle Ages, sometimes with significant diversions, rectifications and channelling; today the watercourse network appears almost entirely artificial, flowing under the streets and buildings of the historic centre. The name of some alleys recalls their presence, which is otherwise not perceptible. Only the upper basin of the Lagaccio and San Lazzaro streams still have a watercourse with a natural riverbed, although the area is still significantly urbanised. The construction of these culverts over time and the modifications they have undergone over the following centuries up to very recent times due to progressive urbanisation have led to a reduction in the hydraulic cross-section, which can lead to a possible flow of water under pressure and the consequent flooding hazard. Therefore a better geographic knowledge of these culverted streams in Genoa historical city is crucial for hazard and risk assessments and for the planning of related hydraulic risk reduction activities

Geo-hydrological hazard underlined by toponymy of Italian Military Geographycal Institute maps at 1:25,000 scale. Contributions to the knowledge of floodplain and hillslope dinamycs

Toponymy is a linguistic discipline, which has already been used as a tool for geographical studies in Italy and particularly in Liguria. Geographical studies have already classified the toponyms in several categories: physical geography, human geography and socio-economic geography. By selecting the place names connected to physical geography, we study those suggesting the presence of landslides or floods. We focussed on the Italian Military Geographic Institute maps at 1: 25.000 scale, edited between 1936-1939 and related to a territory approximately located between Genoa and Chiavari, in Ligurian coastal area, and Tortona and Piacenza in Po valley. On the Ligurian slopes we have examined the maps relating to the Polcevera, Bisagno and Entella streams catchments. For the Po side we dealt with maps of the Scrivia and Trebbia rivers catchments: From the Ligurian-Po watershed, these rivers flow into the Adriatic Sea. The place names have been compared with landslide and flood hazard maps of Basin Master Plans for geo-hydrological risk reduction. The toponyms feature a linguistic layer linked to different historical periods. In particular in the study area several layers have been recognized: the ancient Ligurian pre-Roman, Latin, ancient Lombard, vulgar Gaulish-Italic of local languages and Italian terms related to the twentieth century. The first three layers and the last one match in the entire area of study. The vulgar Gaulish-Italic is structured into two Ligurian and Emilian groups: the latter is further splitted into the Oltrepo variants of Tortona and Piacenza. The identified names were distinguished in related-landslides or floods. In addition, the toponyms have been further divided into three linguistic influence areas: Ligurian, from Ligurian Sea up to Novi Ligure and Bobbio, the language of Tortona, downstream of Novi Ligure and Piacenza from Bobbio to Po river. Overall, place names linked to physical geography features represent nearly 25% of toponyms with a density of about 0.5 per km2. Almost half of these are toponyms related to landslides, floods or predisposing factors such as erosion, steepness or water. The names of places linked to landsliding prevail in Liguria, while those related to the waters or floods in the Po areas are located in plain areas or in very gentle slopes. The most common names related to landslides or erosion are \u201cmoggia\u201d, \u201cliggia\u201d or \u201ccrosi\u201d and similar, which respectively mean swampy deposits, landslides or gullies. Names related to floods are \u201criva\u201d, \u201cpiana\u201d \u201cponte\u201d or \u201cisola\u201d which mean respectively edge of fluvial scarp, floodplain, bridge or isle. The comparison with the Basin Master Plan gave satisfying results: we found a good correspondence between names and geo-hydrological hazard. The use of toponyms allowed a geographycal interpretation of the slope and floodplain dynamics. It suggests a possible use of toponymys in land planning activities

Search for Neutron Flux Generation in a Plasma Discharge Electrolytic Cell

Following some recent unexpected hints of neutron production in setups like high-voltage atmospheric discharges and plasma discharges in electrolytic cells, we present a measurement of the neutron flux in a configuration similar to the latter. We use two different types of neutron detectors, poly-allyl-diglicol-carbonate (PADC, aka CR-39) tracers and Indium disks. At 95% C.L. we provide an upper limit of 1.5 neutrons cm^-2 s^-1 for the thermal neutron flux at ~5 cm from the center of the cell. Allowing for a higher energy neutron component the largest allowed flux is 64 neutrons cm^-2 s^-1. This upper limit is two orders of magnitude smaller than what previously claimed in an electrolytic cell plasma discharge experiment. Furthermore the behavior of the CR-39 is discussed to point our possible sources of spurious signals.Comment: 4 pages, 3 figure

Resistance of European spring 2-row barley cultivars to Pyrenophora graminea and detection of associated loci

Pyrenophora graminea is the seed-borne pathogen causal agent of barley leaf stripe disease. In this work, we screened a collection of 206 spring two-row barley cultivars from Europe for their resistance to the fungal pathogen. Artificial inoculation with the highly virulent isolate Dg2 revealed a continuous variation for the incidence of infection, with few highly resistant or highly susceptible genotypes. On average, old cultivars showed higher resistance than the more modern ones. Genome- Wide Association Scan was performed by exploiting available molecular data for >4000 SNP markers and revealed a single, highly significant association on the short arm of chromosome 6H, in a genomic position where quantitative trait loci (QTL) for barley resistance to P. graminea were not detected before. Based on the last version of the reference barley genome, genes encoding for proteins with a kinase domain were suggested as candidates for the locus

A SIMPLE CAPACITANCE SENSOR FOR VOID FRACTION MEASUREMENT IN GAS-LIQUID TWO-PHASE FLOW

In this work we present a simple and inexpensive capacitance sensor for time averaging void fraction measurement of gas-liquid two-phase flow, which was developed at Experimental Thermalhydraulics Laboratory in the Nuclear Engineering Institute, IEN/CNEN. The sensor is a non-invasive device causing no flow disturbances. It is formed by two parallel plates and four electronic circuits: a signal input circuit, an amplification circuit, a frequency generator, and a power supply circuit. The frequency generator applies a sinusoidal signal with appropriate frequency into the signal input circuit which converts the capacitance variation value (or void fraction) of the two-phase flow into a voltage signal that goes to the amplifier stage; the output signal of the amplifier stage will be an input to an analogical/digital converter, installed inside of a computer, and it will provide interpretation of the signal behavior. The capacitance sensor was calibrated by using a horizontal acrylic tube filled with a known volume of water

Hepatitis a epidemic in men who have sex with men (MSM) in milan, Italy

Background and aim of the work: Hepatitis A is an infectious disease characterized by fecal-oral transmission; however, a rise in sexually-transmitted cases has been observed, particularly among \u201cmen who have sex with men\u201d. In Europe, a Hepatitis A epidemic occurred among men who have sex with men between 2016 and 2018. The aim of this study is to describe this Hepatitis A epidemic in the city of Milan and to analyze the incidence of Sexually Transmitted Diseases co-infection among Hepatitis A cases. Methods: Hepatitis A cases were traced and identified. Epidemiological data were collected and Hepatitis A vaccination was investigated. Cases were georeferenced, calculating incidence rates for each Milan Municipality. Viral genotypic analysis was carried out. Results: 353 cases were reported in Milan. Incidence rates resulted significantly higher in males (RR 18.1 CI9 5% 11.5 - 28.4). 70 cases reported foreign travel. 172 cases reported \u201cMen who have Sex with Men\u201d behaviour. Genotypic analysis revealed correlation with strains of the European \u201cMen who have Sex with Men\u201d epidemic. Georeferencing showed asymmetric case distribution. Only 12 cases reported Hepatitis A vaccination. The Relative Risk for syphilis infection among Hepatitis A cases was 133.9 (95% CI 81.7 - 219.7) and 29.7 (95%CI 9.5 - 92.7) for gonorrhea. Conclusions: Most genotyped cases (93.7%) correlated to the European Hepatitis A epidemic among Men who have Sex with Men. Georeferencing showed a greater incidence of Hepatitis A cases in areas characterized by the homosexual community. The higher incidence of Sexually Transmitted Diseases co-infection in Hepatitis A cases correlated to clusters responsible for the European Hepatitis A epidemic, suggests increased sexual promiscuity among Men who have Sex with Men. These data support the need for Hepatitis A vaccination programs and sensitization of Men who have Sex with Men to the adoption of safe sexual practices