SPITZER IRS spectra of Virgo early type galaxies: detection of stellar silicate emission

We present high signal to noise ratio Spitzer Infrared Spectrograph observations of 17 Virgo early-type galaxies. The galaxies were selected from those that define the colour-magnitude relation of the cluster, with the aim of detecting the silicate emission of their dusty, mass-losing evolved stars. To flux calibrate these extended sources we have devised a new procedure that allows us to obtain the intrinsic spectral energy distribution and to disentangle resolved and unresolved emission within the same object. We have found that thirteen objects of the sample (76%) are passively evolving galaxies with a pronounced broad silicate feature which is spatially extended and likely of stellar origin, in agreement with model predictions. The other 4 objects (24%) are characterized by different levels of activity. In NGC 4486 (M 87) the line emission and the broad silicate emission are evidently unresolved and, given also the typical shape of the continuum, they likely originate in the nuclear torus. NGC 4636 shows emission lines superimposed on extended (i.e. stellar) silicate emission, thus pushing the percentage of galaxies with silicate emission to 82%. Finally, NGC 4550 and NGC 4435 are characterized by polycyclic aromatic hydrocarbon (PAH) and line emission, arising from a central unresolved region. A more detailed analysis of our sample, with updated models, will be presented in a forthcoming paper.Comment: 6 pages; ApJ Letters, accepte

Some new well-posedness results for continuity and transport equations, and applications to the chromatography system

We obtain various new well-posedness results for continuity and transport equations, among them an existence and uniqueness theorem (in the class of strongly continuous solutions) in the case of nearly incompressible vector fields, possibly having a blow-up of the BV norm at the initial time. We apply these results (valid in any space dimension) to the k x k chromatography system of conservation laws and to the k x k Keyfitz and Kranzer system, both in one space dimension.Comment: 33 pages, minor change

A resource based approach in the context of the emerging craft brewing industry

Purpose: The purpose of this exploratory study is to examine the perceived resources, strengths, weaknesses, opportunities and threats from the perspective of micro and small brewery owners, managers and brewing masters operating in three countries. To this end, the study adopts the resource based view (RBV) of the firm, complemented by a SWOT analysis. Design/methodology/approach: The research provides a mixed methods approach. Data were collected from craft breweries in Italy, Spain and the United Kingdom (UK). 165 valid responses were obtained from an online questionnaire, and an additional 24 face-to-face and telephone interviews with craft brewing operators in these three countries were conducted to further enrich the data. Independent samples t-test and Scheffé post hoc were used to analyse part of the quantitative data, while content analysis and word association were used for the qualitative component. Findings: Product quality and uniqueness of product emerged as important perceived resources and strengths, suggesting an alignment with some of the resource related attributes postulated by the RBV, such as valuable, rare, and (un)substitutable. Other elements, such as natural and sustainable resources, including water quality and the current and future involvement in growing or sourcing raw products locally emerged as key resources, and are suggested as additional attributes. These strategic and tangible resources are however challenged by perceived weaknesses, particularly lack of financial, infrastructure and commercialisation resources, as well as threats from competition. Originality/value: The exploratory study focuses on craft brewing from the perspective of micro/small operators. This industry has received very limited attention from the literature. The use of the RBV, with the potential to increase understanding of an emerging industry, and develop the theory further in this domain, adds to the originality and value of this research

The Ages of Elliptical Galaxies from Infrared Spectral Energy Distributions

The mean ages of early-type galaxies obtained from the analysis of optical spectra, give a mean age of 8 Gyr at z = 0, with 40% being younger than 6 Gyr. Independent age determinations are possible by using infrared spectra (5-21 microns), which we have obtained with the Infrared Spectrograph on the Spitzer Observatory. This age indicator is based on the collective mass loss rate of stars, where mass loss from AGB stars produces a silicate emission feature at 9-12 microns. This feature decreases more rapidly than the shorter wavelength continuum as a stellar population ages, providing an age indicator. From observations of 30 nearby early-type galaxies, 29 show a spectral energy distribution dominated by stars and one has significant emission from the ISM and is excluded. The infrared age indicators for the 29 galaxies show them all to be old, with a mean age of about 10 Gyr and a standard deviation of only a few Gyr. This is consistent with the ages inferred from the values of M/L_B, but is inconsistent with the ages derived from the optical line indices, which can be much younger. All of these age indicators are luminosity-weighted and should be correlated, even if multiple-age components are considered. The inconsistency indicates that there is a significant problem with either the infrared and the M/L_B ages, which agree, or with the ages inferred from the optical absorption lines.Comment: Accepted for publication in Ap

Priorities for Cancer Research From the Viewpoints of Cancer Nurses and Cancer Patients: A Mixed-Method Systematic Review

BACKGROUND: Setting priorities in oncology is a useful way to produce a robust set of research questions that researchers can address. OBJECTIVE: The aim of this review was to describe cancer nurses and patients' main research priorities and describe their development over time. METHODS: A mixed-method systematic review was conducted for the period from 2000 to 2018 through a search of multiple databases. The methodological quality of the studies included was assessed using the Mixed-Methods Appraisal Tool, and the process of setting the health research priorities was assessed using Viergever's tool. Each study's top research priorities were extracted and summarized in categories. RESULTS: Fifteen studies were included: 13 addressed nurses' research priorities, and 2 focused on those of patients. The majority were Delphi and quantitative studies that were conducted in the United States and United Kingdom. The quality criteria score and the quality of the process were considered sufficiently good. The most important research priorities were categorized as disease control and management, patient-related issues, and professional dimensions and issues. Management of symptoms and pain, education, information, and communication were research priorities always present in the articles during the study period. CONCLUSION: Priorities change over time and depend on several factors; however, some have remained consistent for the last 18 years. Although there is increasing emphasis on including patients in establishing research priorities that inform cancer care, this involvement is still lacking. IMPLICATIONS FOR PRACTICE: Future studies should describe the primary cancer research priorities of nurses in collaboration with patients

Correlation Clustering with Adaptive Similarity Queries

In correlation clustering, we are givennobjects together with a binary similarityscore between each pair of them. The goal is to partition the objects into clustersso to minimise the disagreements with the scores. In this work we investigatecorrelation clustering as an active learning problem: each similarity score can belearned by making a query, and the goal is to minimise both the disagreementsand the total number of queries. On the one hand, we describe simple activelearning algorithms, which provably achieve an almost optimal trade-off whilegiving cluster recovery guarantees, and we test them on different datasets. On theother hand, we prove information-theoretical bounds on the number of queriesnecessary to guarantee a prescribed disagreement bound. These results give a richcharacterization of the trade-off between queries and clustering error

UGC 3995: A Close Pair of Spiral Galaxies

UGC 3995 is a close pair of spiral galaxies whose eastern component hosts a Seyfert 2 nucleus. We present a detailed analysis of this system using long slit spectroscopy and narrow (\ha + \nii) as well as broad band (B, R) imaging and an archive WFPC2 image. The component galaxies reveal surprisingly small signs of interaction considering their spatial proximity and almost identical recession velocities, as the bright filament is probably an optical illusion due to the superposition of the bar of the Seyfert galaxy and of the spiral arms of the companion. The broad band morphology, a B--R color map, and a continuum-subtracted \ha + \nii image demonstrate that the western component UGC 3995B is in front of the Seyfert-hosting component UGC 3995A, partly obscuring its western side. The small radial velocity difference leaves the relative motion of the two galaxies largely unconstrained. The observed lack of major tidal deformations, along with some morphological peculiarities, suggests that the galaxies are proximate in space but may have recently approached each other on the plane of the sky. The geometry of the system and the radial velocity curve at P. A. = 106 suggest that the encounter may be retrograde or, alternatively, prograde before perigalacticon. The partial overlap of the two galaxies allows us to estimate the optical thickness of the disk of component B. We derive an extinction = 0.18 visual magnitudes in the infra-arms parts of the foreground galaxy disk, and >= 1-1.5 visual magnitudes in correspondence of the spiral arms.Comment: Accepted for publication in the Astronomical Journal (June 1999 issue

Stellar populations in gas-rich galaxy mergers II. Feedback effects of Type Ia and II supernovae

We numerically investigate chemodynamical evolution of major disk-disk galaxy mergers in order to explore the origin of mass-dependent chemical, photometric, and spectroscopic properties observed in elliptical galaxies. We particularly investigate the dependence of the fundamental properties on merger progenitor disk mass (M_d). Main results obtained in this study are the following three. (1) More massive (luminous) ellipticals formed by galaxy mergers between more massive spirals have larger metallicity (Z) and thus show redder colors: The typical metallicity ranges from ~ 1.0 solar abundance (Z~ 0.02) for ellipticals formed by mergers with M_d = 10^10 M_solar to ~ 2.0 solar (Z ~ 0.04) for those with M_d = 10^12 M_solar. (2) The absolute magnitude of negative metallicity gradients developed in galaxy mergers is more likely to be larger for massive ellipticals. Absolute magnitude of metallicity gradient correlates with that of age gradient in ellipticals in the sense that an elliptical with steeper negative metallicity gradient is more likely to show steeper age gradient. (3) Both M/L_B and M/L_K, where M, L_B, and L_K are total stellar mass of galaxy mergers, B-band luminosity, and K-band one, respectively, depend on galactic mass in such a way that more massive ellipticals have larger M/L_B and smaller M/L_K.Comment: 58 pages 16 figures, ApJ in press (March 1999 issue

Experimental transmission by Scaphoideus titanus Ball of two Flavescence doree-type phytoplasmas

During the last 5 years Flavescence doree (FD) has been expanding from the first loci of outbreak in the Veneto region, to the major viticultural areas of northern Italy, showing increased infection rates in 1999. The FD vector is Scaphoideus titanus Ball. Recently it has been demonstrated that in Veneto FD is associated with two molecularly distinguishable types of phytoplasmas, both belonging to the 16SrV group (Elm yellows and related strains). In 1997 the two phytoplasma types appeared to be geographically separated in 1997: FD-16SrV-D was found in the provinces of Verona, Vicenza, Venice and Padova, infecting mainly cvs Garganega and Chardonnay while FD-16SrV-C occurred in the Treviso province, infecting cultivars Prosecco, Chardonnay and Perera. During 1998 the two types started to merge in Treviso province, showing that 16SrV-D was transmitted more efficently and over longer distances than the other type. From the transmission trials carried out in 1998 and 1999 in order to gain more information about the epidemiology of the two types of FD agents, S. titanus was found to be able to transmit both 16SrV-C and 16SrV-D phytoplasmas.