320 research outputs found
PAHs and star formation in the HII regions of nearby galaxies M83 and M33
We present mid-infrared (MIR) spectra of HII regions within star-forming
galaxies M83 and M33. Their emission features are compared with Galactic and
extragalactic HII regions, HII-type galaxies, starburst galaxies, and
Seyfert/LINER type galaxies. Our main results are as follows: (i) the M33 and
M83 HII regions lie in between Seyfert/LINER galaxies and HII-type galaxies in
the 7.7/11.3 - 6.2/11.3 plane, while the different sub-samples exhibiting
different 7.7/6.2 ratios; (ii) Using the NASA Ames PAH IR Spectroscopic
database, we demonstrate that the 6.2/7.7 ratio does not effectively track PAH
size, but the 11.3/3.3 PAH ratio does; (iii) variations on the 17 m PAH
band depends on object type; however, there is no dependence on metallicity for
both extragalactic HII regions and galaxies; (iv) the PAH/VSG intensity ratio
decreases with the hardness of the radiation field and galactocentric radius
(Rg), yet the ionization alone cannot account for the variation seen in all of
our sources; (v) the relative strength of PAH features does not change
significantly with increasing radiation hardness, as measured through the
[NeIII]/[NeII] ratio and the ionization index; (vi) We present PAH SFR
calibrations based on the tight correlation between the 6.2, 7.7, and 11.3
m PAH luminosities with the 24 m luminosity and the combination of
the 24 m and H luminosity; (vii) Based on the total luminosity
from PAH and FIR emission, we argue that extragalactic HII regions are more
suitable templates in modeling and interpreting the large scale properties of
galaxies compared to Galactic HII regions.Comment: 26 pages, 24 figures, 6 tables. Accepted for publication in MNRA
Το σύμπλεγμα εθνικού και τοπικού στην οριοθέτηση μουσικών ταυτοτήτων: Η περίπτωση της βιολιστικής “παράδοσης” στο Νομό Χανίων (ιστοριογραφική προσέγγιση)
Στην παρούσα διπλωματική εργασία εξετάζεται το επίπεδο αλληλεπίδρασης και διαφοροποίησης μεταξύ του “παν-τοπικού” ταυτοτικού πλαίσιου της “Κρητικής μουσικής” και του “τοπικού” ταυτοτικού πλαισίου της “βιολιστικής παράδοσης” στο Ν. Χανίων με επίκεντρο την επαρχία Κισάμου. Το ερευνητικό ερώτημα αφορά κυρίως στις πρακτικές και τα “υλικά” που χρησιμοποιήθηκαν ως προς την οριοθέτησή των “παραδόσεων” αυτών. Τα ταυτοτικά χαρακτηριστικά που παρουσιάζονται ως προς την ομογενοποίηση ή ετεροποίηση τους απαντώνται σε μεγάλο βαθμό στην ιδεολογική βάση της “ελληνικότητας” διαφόρων μουσικών παραμέτρων και ειδικότερα την ιστορική - πολεμική ταύτιση των μουσικοχορευτικών τους μοτίβων. Οι βασικές πηγές στοιχειοθέτησης των παραπάνω χαρακτηριστικών, προέρχονται κυρίως από την “εθνική ιστοριογραφική αφήγηση” και τις λαογραφικές θέσεις του 19ου και 20ού αιώνα. Βασικό στοιχείο ετερότητας αποτέλεσαν επίσης οι πρακτικές ανάδειξης της λύρας σε “παν-τοπικό” κρητικό όργανο, καθώς προκαλέσαν “ανταγωνισμούς” και διενέξεις σε σχέση με τη θέση του βιολιού στην “Κρητική μουσική”. Ως προς τη διερεύνηση των ζητημάτων που αναφέρθηκαν, μελετώνται:
• Το ιστορικό - κοινωνικό πλαίσιο της οθωμανικής Κρήτης και ο ρόλος της εντόπιας μουσουλμανικής κοινότητας.
• Η ιστορική ιδεολογική οριοθέτηση της “κρητικής μουσικής” από τους πρώτους λαογράφους και μελετητές της.
• Τα μουσικά πλαίσια στα αστικά κέντρα της Κρήτης και στις επαρχίες του Ν. Χανίων έως τις αρχές 20ού αιώνα.
• Η παρουσία των μουσικών οργάνων στο Ν. Χανίων, καθώς και η προέλευση-παρουσία της λύρας στον ελληνικό γεωγραφικό χώρο και ειδικότερα στη διερευνώμενη περιοχή.
• Οι κεντρικοί άξονες στους οποίους δομείται ταυτοτικά η “Χανιώτικη ή Κισαμίτικη βιολιστική παράδοση”, όσον αφορά την ιστορική της εννοιολόγηση, τις προσωπικότητες και τα γεγονότα που είχαν σημαντικό ρόλο στην ανάπτυξή της.Τhe present master’s thesis examines the level of interaction and differentiation between the “pan-local” identity frame of “Cretan music” and the “local” identity frame of the “violin tradition” in the Prefecture of Chania. The research question mainly concerns the practices and the “material” that have been used for the delimitation of these “traditions”. The identity characteristics that are presented regarding their homogenization or their differentiation, are found to a great degree in the ideological basis of the “greek origin” of various musical parameters, and especially the historical- polemical identification of their music and dance patterns. The basic source of evidence of the aforementioned characteristics, derive mainly from the “national historiographical narration” and the folkloric views of the 19th and 20th century. Furthermore, the practices of the promotion of lyra in a “pan-local” cretan organ have constituted a basic element of distinctness since they have provoked “competitions” and dispute regarding the position of the violin in “Cretan music”. As to the investigation of the aforementioned matters, the following subjects are studied:
• The historic-social frame of ottoman Crete and the role of the indigenous muslim community.
• The historic ideological delimitation of “cretan music” from her first folklorists and scholars.
• The musical frames in the urban centers of Crete and the province of the Prefecture of Chania until the beginning of the 20th century.
• The presence of musical instruments in the Prefecture of Chania, as well as the derivation- presence of lyra in the hellenic geographical space and especially in the investigated region.
• The main axis in which the identity of “violin tradition of Chania or Kissamos” is structured, concerning the historic conceptualization, the personalities and the facts that played a significant role in its development
Polycyclic Aromatic Hydrocarbon Size Tracers
We examine the dependence of polycyclic aromatic hydrocarbon (PAH) band
intensity ratios as a function of the average number of carbon atoms and assess
their effectiveness as tracers for PAH size, utilising the data, models, and
tools provided by the NASA Ames PAH Infrared Spectroscopic Database. To achieve
this, we used spectra from mixtures of PAHs of different ionisation fractions,
following a size distribution. Our work, congruent with earlier findings, shows
that band ratios that include the 3.3 m PAH band provide the best PAH
size tracers for small-to-intermediate sized PAHs. In addition, we find that
band ratios that include the sum of the 15-20 m PAH features
(I) and the 6.2 or 7.7 m bands also serve as good
tracers for PAH size in the case of small-to-intermediate sized PAHs, for
objects under a similar PAH size distribution as with the presented models. For
different PAH size distributions, the application of a scaling factor to the
I/I ratio can provide estimates for the size of the
small-to-intermediate PAH population within sources. Employment of the
I/I and I/I ratios can be
of particular interest for JWST observations limited only to 5-28
m MIRI(-MRS) coverage.Comment: 8 pages, 5 figures; Accepted for publication in MNRA
Esperienze creative e collaborative con il teatro d’ombre
Storytelling is a very common educational practice that is used in every level of education. It has a positive impact in children’s learning and creativity. Often the educational use of storytelling is based on national storytelling traditions such as Shadow Theater which is very popular in many countries including Greece. Inthis research we present eShadow, a storytelling tool inspired by the Greek traditional shadow theater and how it has been used in a number of Adult Learning Pilot Programmes (ALPPs) implemented within the context of the ALICE project in Greece.In these ALPPs, intra-family communication scenarios were investigated as well as scenarios related to enabling children develop their own digital stories using eShadow. Furthermore, eShadow was used in a live interactive performance event combining Music and Digital Shadow Theatre. The evidence gathered during the implementation of these ALPPs confirms that such kind of approaches can indeed enhance intergenerational bonding and create an engaging learning space for children to develop important key skills. Our findings illustrate that eShadowis very easy to use, attracts the interest of both children and teachers and has a positive impact on the development of children’s creativity.Lo storytelling è una pratica molto comune in ambito formative ed educativo, utilizzata ad ogni livello di istruzione. Ha un impatto positivo sull’apprendimento e la creatività dei bambini. Spesso l’uso didattico dello storytelling si basa su espressioni narrative ben conosciute a livello nazionale, qual è il caso del teatrodelle ombre, molto popolare in molti paesi tra cui la Grecia. In questa ricerca presentiamo i risultati dell’implementazione di uno strumento digitale, “eShadow”, ispirato al tradizionale teatro delle ombre greco, nel contesto di un certo numero di attività pilota per la formazione degli adulti (Adult Learning Pilot Programmes,ALPPS) attuate nel contesto del progetto ALICE, in Grecia.In questi ALPPS, gli scenari di comunicazione intra-familiari sono stati studiati così come scenari che consentono ai bambini di sviluppare le proprie abilità per il lavoro con lo strumento digitale eShadow. Inoltre, eShadow è stato utilizzato in evento interattivo che univa presentazioni di Musica e Teatro con la presenzadi teatro delle ombre “digitale”. Le prove raccolte nel corso di questi ALPPS conferma l’ipotesi degli autori che questo tipo di approcci può infatti migliorare i legami intergenerazionali e consente di sviluppare importanti competenze chiave sia negli adulti che nei bambini. I nostri risultati mostrano che eShadow è molto facile da usare, attira l’interesse di bambini e insegnanti e ha un positivoimpatto sullo sviluppo della creatività dei bambini
Tomorrow's healthy society - Research priorities for foods and diets
Health promotion and disease prevention through provision and consumption of healthy diets are increasingly recognised as crucial, both socially and economically, in the face of strained healthcare systems, an ageing population, and the high individual and economic costs of diseases.The Foresight study ‘Tomorrow's healthy society – research priorities for foods and diets’ was initiated to inform the selection of research challenges to receive funding under the Horizon 2020 programme. The exploratory scenario-building approach focused on the European consumer with the year 2050 as a long-term time horizon. Four different future scenarios were developed using the extremes of two main drivers – agricultural commodity prices (low or high) and societal values (community spirit or individualistic society). The scenarios provided the basis for the identification and prioritisation of research needs to address the challenges and opportunities arising from the different scenarios. The resulting ten research priorities fall into four thematic areas: Towards healthier eating: integrated policy-making; Food, nutrients and health: cross-interactions and emerging risks; Making individualised diets a reality; and Shaping and coping with the 2050 food system.JRC.DDG.02-Foresight and Behavioural Insight
The Star Formation Reference Survey - III. A multiwavelength view of star formation in nearby galaxies
We present multiwavelength global star formation rate (SFR) estimates for 326 galaxies from the Star Formation Reference Survey in order to determine the mutual scatter and range of validity of different indicators. The widely used empirical SFR recipes based on 1.4 GHz continuum, 8.0 μm polycyclic aromatic hydrocarbons (PAHs), and a combination of far-infrared (FIR) plus ultraviolet (UV) emission are mutually consistent with scatter of ≲0.3 dex. The scatter is even smaller, ≲0.24 dex, in the intermediate luminosity range 9.3 \u3c log(L60 μm/L⊙) \u3c 10.7. The data prefer a non-linear relation between 1.4 GHz luminosity and other SFR measures. PAH luminosity underestimates SFR for galaxies with strong UV emission. A bolometric extinction correction to far-UV luminosity yields SFR within 0.2 dex of the total SFR estimate, but extinction corrections based on UV spectral slope or nuclear Balmer decrement give SFRs that may differ from the total SFR by up to 2 dex. However, for the minority of galaxies with UV luminosity \u3e 5 × 109 L⊙ or with implied far-UV extinction \u3c 1mag, the UV spectral slope gives extinction corrections with 0.22 dex uncertainty
Active Peptic Ulcer Disease in Patients with Hepatitis C Virus-Related Cirrhosis: The Role of Helicobacter pylori
BACKGROUND & AIM: The relationship between Helicobacter pylori infection and peptic ulcer disease in cirrhosis remains controversial. The purpose of the present study was to investigate the role of H pylori infection and portal hypertension gastropathy in the prevalence of active peptic ulcer among dyspeptic patients with compensated hepatitis C virus (HCV)-related cirrhosis
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