A multi-wavelength study of the starburst galaxy NGC 7673

HST/WFPC2 images resolved NGC 7673 into a large number of star clusters. Among these, 31 fall inside the IUE large aperture, which was used to acquire an integrated ultraviolet spectrum of the galaxy. We have fitted Starburst99 evolutionary synthesis models to the observed colours of these clusters and derived ages, reddenings, and masses of the clusters. Then a simple sum of the clusters synthetic UV spectra has been compared to the observed IUE spectrum, in order to investigate the star formation history of NGC 7673.Comment: 6 pages, 2 figures, to appear in the Proceedings of the Conference "Starburst-from 30 Doradus to Lyman Break Galaxies

Long term Arecibo monitoring of the water megamaser in MG J0414+0534

We monitored the 22 GHz maser line in the lensed quasar MG J0414+0534 at z=2.64 with the 300-m Arecibo telescope for almost two years to detect possible additional maser components and to measure a potential velocity drift of the lines. The main maser line profile is complex and can be resolved into a number of broad features with line widths of 30-160 km/s. A new maser component was tentatively detected in October 2008 at a velocity of +470 km/s. After correcting for the estimated lens magnification, we find that the H2O isotropic luminosity of the maser in MG J0414+0534 is about 26,000 solar luminosities, making this source the most luminous ever discovered. Both the main line peak and continuum flux densities are surprisingly stable throughout the period of the observations. An upper limit on the velocity drift of the main peak of the line has been estimated from our observations and is of the order of 2 km/s per year. We discuss the results of the monitoring in terms of the possible nature of the maser emission, associated with an accretion disk or a radio jet. This is the first time that such a study is performed in a water maser source at high redshift, potentially allowing us to study the parsec-scale environment around a powerful radio source at cosmological distances.Comment: 5 pages, 2 figures, to appear in the Proceedings of the IAU Symposium 287, 2012, "Cosmic masers: from OH to H0

Creating with Anger: Contemplating Vendetta. An Analysis of Anger in Italian and Spanish Women Writers of the Early Modern Era

In the vast gamut of human emotions, anger is one of the most complex, provocative, and enduring. From Greek philosophers working in antiquity to today’s most recent theories on emotions, most scholars agree that anger has a multifaceted nature. This near universal agreement across the barriers of time and geography stems from the following facts: in order to exist, anger involves the participation of other emotions; anger does not have an opposite; anger leads an individual to engage in an act of self-analysis and in an evaluation of other individuals; and, finally, anger inspires action to right a wrong that has been perceived as injustice. This sense of perceived injustice is what leads to the creation of vendetta for the women writers I analyze in my dissertation. They achieve their vendetta through their act of writing, as they themselves often assert. Like all vendetta, theirs grows from a sense of constant injustice and systematic subjugation. Unlike traditional vendetta however, these women, because of their status within society as women, could not take direct action to right these perceived wrongs. Their need for revenge therefore had to be fulfilled entirely through the written word, with their poems, plays, novels and short stories serving as the vehicles through which their anger could be delivered. This dissertation investigates the connection between anger and the act of writing. Specifically, it attempts to explore how anger served as a vital catalyst that prompted early modern women writers to engage in the act of writing

New H_(2)O masers in Seyfert and FIR bright galaxies: III. The southern sample

Context. A relationship between the water maser detection rate and far infrared (FIR) flux densities was established as a result of two 22 GHz maser surveys in a complete sample of galaxies (Dec > −30°) with flux densities of >50 Jy and >30 Jy. Aims. We attempted to discover new maser sources and investigate the galaxies hosting the maser spots by extending previous surveys to southern galaxies with particular emphasis on the study of their nuclear regions. Methods. A sample of 12 galaxies with Dec 50 Jy was observed with the 70-m telescope of the Canberra deep space communication complex (CDSCC) at Tidbinbilla (Australia) in a search for water maser emission. The average 3σ noise level of the survey was 15 mJy for a 0.42 km s^(−1) channel, corresponding to a detection threshold of ∼0.1 L_☉ for the isotropic maser luminosity at a distance of 25 Mpc. Results. Two new detections are reported: a kilomaser with an isotropic luminosity L_(H_(2)O) ~ 5 L_☉ in NGC 3620 and a maser with about twice this luminosity in the merger system NGC 3256. The detections have been followed-up by continuum and spectral line interferometric observations with the Australia Telescope Compact Array (ATCA). In NGC 3256, a fraction (about a third) of the maser emission originates in two hot spots associated with star formation activity, which are offset from the galactic nuclei of the system. The remaining emission may originate in weaker centres of maser activity distributed over the central 50". For NGC 3620, the water maser is coincident with the nuclear region of the galaxy. Our continuum observations indicate that the nature of the nuclear emission is probably linked to particularly intense star formation. Including the historical detection in NGC 4945, the water maser detection rate in the southern sample is 15% (3/20), consistent with the northern sample. The high rate of maser detections in the complete all-sky FIR sample (23%, 15/65) confirms the existence of a link between overall FIR flux density and maser phenomena. A relation between H_(2)O and OH masers in the FIR sample is also discussed

VLBI observations of the H2O gigamaser in TXS2226-184

Outside the Milky Way, the most luminous H2O masers at 22 GHz, called 'megamasers' because of their extreme luminosity with respect to the Galactic and extragalactic H2O masers associated with star formation, are mainly detected in active galactic nuclei. In the case of the H2O maser detected in the nuclear region of the galaxy TXS2226-184 for the first time the term 'gigamaser' was used. However, the origin of this very luminous H2O maser emission has never been investigated into details. We study the nature of the H2O gigamaser in TXS2226-184 by measuring for the first time its absolute position at mas resolution, by comparing the morphology and characteristics of the maser emission at the VLBI scales after about 20 years, and by trying to detect its polarized emission. We observed the maser emission towards TXS2226-184 three times: the very first one with the VLBA (epoch 2017.45) and the next two times with the EVN (epochs 2017.83 and 2018.44). The first two epochs were observed in phase-reference mode, while the last epoch was observed in full-polarization mode but not in phase-reference mode to increase the on-source integration time. We also retrieved and analyzed the VLBA archival data at 22 GHz of TXS2226-184 observed in 1998.40. We detected 6 H2O maser features in epoch 2017.45 (VLBA), one in epoch 2017.83 (EVN), and two in epoch 2018.44 (EVN). All of them but one are red-shifted with respect to the systemic velocity of TXS2226-184, we detected only one blue-shifted maser feature and it is the weakest one. For the first time, we were able to measure the absolute position of the H2O maser features with errors below 1 mas. No linear and circular polarization was detected. We were able to associate the H2O maser features in TXS2226-184 with the most luminous radio continuum clump reported in the literature.Comment: 13 pages, 10 figures, 3 tables, accepted for publication by Astronomy & Astrophysic

AGN and Megamasers

Luminous extragalactic masers are traditionally referred to as the `megamasers'. Those produced by water molecules are associated with accretion disks, radio jets, or outflows in the nuclear regions of active galactic nuclei (AGN). The majority of OH maser sources are instead driven by intense star formation in ultra-luminous infrared galaxies, although in a few cases the OH maser emission traces rotating (toroidal or disk) structures around the nuclear engines of AGN. Thus, detailed maser studies provide a fundamental contribution to our knowledge of the main nuclear components of AGN, constitute unique tools to measure geometric distances of host galaxies, and have a great impact on probing the, so far, paradigmatic Unified Model of AGN.Comment: 11 pages, 3 figures, invited review to appear in Proc. IAU 287 "Cosmic Masers: from OH to H_0", R.S. Booth, E.M.L. Humphreys and W.H.T. Vlemmings, ed

From Grape By-Products to Enriched Yogurt Containing Pomace Extract Loaded in Nanotechnological Nutriosomes Tailored for Promoting Gastro-Intestinal Wellness

Grape pomace is the main by-product generated during the winemaking process; since it is still rich in bioactive molecules, especially phenolic compounds with high antioxidant power, its transformation in beneficial and health-promoting foods is an innovative challenge to extend the grape life cycle. Hence, in this work, the phytochemicals still contained in the grape pomace were recovered by an enhanced ultrasound assisted extraction. The extract was incorporated in liposomes prepared with soy lecithin and in nutriosomes obtained combining soy lecithin and Nutriose FM06®, which were further enriched with gelatin (gelatin-liposomes and gelatin-nutriosomes) to increase the samples’ stability in modulated pH values, as they were designed for yogurt fortification. The vesicles were sized ~100 nm, homogeneously dispersed (polydispersity index < 0.2) and maintained their characteristics when dispersed in fluids at different pH values (6.75, 1.20 and 7.00), simulating salivary, gastric and intestinal environments. The extract loaded vesicles were biocompatible and effectively protected Caco-2 cells against oxidative stress caused by hydrogen peroxide, to a better extent than the free extract in dispersion. The structural integrity of gelatin-nutriosomes, after dilution with milk whey was confirmed, and the addition of vesicles to the yogurt did not modify its appearance. The results pointed out the promising suitability of vesicles loading the phytocomplex obtained from the grape by-product to enrich the yogurt, offering a new and easy strategy for healthy and nutritional food development.Ecosystem of Innovation for Next Generation Sardinia” funded by the Italian Ministry of University and ResearchNext- Generation EU Programme (National Recovery and Resilience Plan—PNRR, M4C2, INVESTMENT 1.5—DD 1056 of 23/06/2022, ECS00000038)The European Union under the ENI CBC MED Programme 2014–2020, BESTMEDGRAPE Project reference number A_A.2.1_0035Fondazione di Sardegna 202

New lipid nanovesicles as topical delivery sistems for ant-inflammatory drugs

The purpose of the present study was to formulate new vesicular carriers to optimize the topical delivery of anti-inflammatory drugs: diclofenac, quercetin and curcumin. In the first work concentrated and interconnected penetration enhancer containing vesicles (PEVs) are proposed as carriers for dermal delivery of diclofenac. PEVs were prepared by using a commercial phosphatidylcholine mixture (180 mg/m) and transcutol in different amounts. Conventional liposomes were also prepared and tested as control. All vesicles showed a mean size ranging from 75 to 253 nm with fairly narrow size distribution, negative zeta potential value, and drug loading capacity between 48 and 70%. SWAXS studies showed that composition affected vesicle structure and morphology: 10 and 30% transcutol PEVs were unilamellar while liposomes and 20% transcutol PEVs were multilamellar. Rheological studies demonstrated that control liposomes and 10 and 30% transcutol containing PEVs behaved as Newtonian fluids while 20% transcutol containing PEVs showed a plastic behavior. Ex vivo (trans)dermal delivery experiments showed an improved skin deposition of diclofenac when PEVs were used. Vesicle toxicity and uptake of fibroblasts, target of inflammation treatment, were evaluated by MTT test and fluorescence microscopy. Control liposomes and PEVs were both able to interact and being internalized by the 3T3 fibroblasts at all time exposure tested. Furthermore, PEVs showed to be able to reduce the in vitro drug toxicity. The aim of the second study was to improve the knowledge of drug–glycol–phospholipid-interactions and their effects in lamellar vesicle suitability as drug delivery systems. Liposomes were prepared using hydrogenated soy phosphatidylcholine (P90H, 60 mg/ml) and diclofenac sodium salt at two con-centrations (5–10 mg/ml). To obtain innovative vesicles two permeation enhancers with glycol group, diethyleneglycol monoethyl ether and propylene glycol, were added to the water phase at different ratios (5%, 10%, and 20%). Vesicle organization was deeply investigated by physico-chemical characterization, including differen-tial scanning calorimetry and small-angle diffraction signal analysis while macroscopic structure behavior was evaluated by rheological studies. Results evidenced that the presence of the penetration enhancer and diclofenac sodium salt led to structural rearrangements within and among vesicles forming a tridi-mensional and complex architecture in which vesicles were closely packed and interconnected. This new design allowed a change in the physical state of dispersions that became highly viscous liquid or soft-solid-like, thus forming an ideal system for topical application able of both adhering to the skin and delivering the drug. © 2013 Elsevier B.V. All rights reserved. In the last work biocompatible quercetin and curcumin nanovesicles were developed as a novel approach to prevent and restore skin tissue defects on chronic cutaneous pathologies. Stable and suitable quercetin- and curcumin-loaded phospholipid vesicles, namely liposomes and penetration enhancercontaining vesicles (PEVs), were prepared. Vesicles were made from a highly biocompatible mixture of phospholipids and alternatively a natural polyphenol, quercetin or curcumin. Liposomes were obtained by adding water, while PEVs by adding polyethylene glycol 400 and Oramix_CG110 to the water phase. Transmission electron microscopy, cryogenic-transmission electron microscopy and small- and wideangle X-ray scattering showed that vesicles were spherical, oligo- or multilamellar and small in size (112–220 nm). In vitro and in vivo tests underlined a good effectiveness of quercetin and curcumin nanovesicles in counteracting phorbol ester 12-O-tetradecanoylphorbol-13-acetate (TPA) induced lesions and inflammation. Myeloperoxydase activity, used to gauge inflammation, was markedly inhibited by quercetin liposomes (59%) and curcumin liposomes and polyethylene glycol (PEG)-PEVs (_68%). Histology showed that PEG-PEVs provided an extensive re-epithelization of the TPA-damaged skin, with multiple layers of thick epidermis. In conclusion, nanoentrapped polyphenols prevented the formation of skin lesions abrogating the various biochemical processes that cause epithelial loss and skin damage