224 research outputs found
Distances, ages, and epoch of formation of globular clusters
We review the results on distances and absolute ages of galactic globular
clusters (GCs) obtained after the release of the Hipparcos catalogue. Several
methods for the Population II local distance scale are discussed, exploiting
NEW RESULTS for RR Lyraes in the Large Magellanic Cloud (LMC). We find that the
so-called Short and Long Distance Scales may be reconciled whether a consistent
reddening scale is adopted for Cepheids and RR Lyrae variables in the LMC.
Distances and ages for the 9 clusters discussed in Paper I are re-derived using
an enlarged sample of local subdwarfs, which includes about 90% of the
metal-poor dwarfs with accurate parallaxes (Delta p/p < 0.12) in the whole
Hipparcos catalogue. On average, our revised distance moduli are decreased by
0.04 mag with respect to Paper I. The corresponding age of the GCs is
t=11.5+-2.6 Gyr (95% confidence range). The relation between Mv(ZAHB) and
metallicity for the nine programme clusters turns out to be
Mv(ZAHB)=(0.18+-0.09)([Fe/H]+1.5)+(0.53+-0.12).Thanks to Hipparcos the major
contribution to the total error budget associated with the subdwarf fitting
technique has been moved from parallaxes to photometric calibrations, reddening
and metallicity scale. This total uncertainty still amounts to about +-0.12
mag. Comparing the corresponding (true) LMC distance modulus 18.64+-0.12 mag
with other existing determinations, we conclude that at present the best
estimate for the distance of the LMC is: 18.54+-0.03+-0.06, suggesting that
distances from the subdwarf fitting method are 1 sigma too long. Consequently,
our best estimate for the age of the GCs is revised to: Age = 12.9+-2.9 Gyr
(95% confidence range). The best relation between Mv(ZAHB) and [Fe/H] is:
Mv(ZAHB) =(0.18+-0.09)([Fe/H]+1.5)+(0.63+-0.07).Comment: 76 pages, 6 encapsulated figures and 6 tables. Latex, uses
aasms4.sty. Revised and improved version, with new data on field RR Lyraes in
LMC. Accepted in the Astrophysical Journa
Marketing madness or financial folly?: Implementing equity crowdfunding in the record industry
Purpose The purpose of this paper is to explore the implementation of equity crowdfunding (ECF) within the record industry in terms of challenges and opportunities, in addition to the marketing and financial implications for independent music artists and major record labels. Design/methodology/approach This study adopted a qualitative methodology consisting of two-stage interview-based research methods. A total of 44 semi-structured in-depth interviews were conducted with the CEOs of ECF platforms in the record industry, other related record industry informants, independent artist managers and senior executives from major record labels. Findings The loyalty aspect of ECF may have significant marketing potential in terms of inconspicuously using the equity platform as a “prosumer” identification mechanism. As this early career stage of artists is delicate in terms of establishing trust and patronage from their fans, these early marketing and ECF ventures should be implemented directly from the artist without external third-party involvement. Research limitations/implications The implications of this paper’s findings and theoretical model are not limited to the two studied stakeholder groups of the record industry. The insights in relation to the obstinate lack of understanding and clarity (particularly for independent artists) which surround ECF are likely to influence short-term strategic approaches by other players throughout the wider music industry. Practical implications The insights regarding negative approaches towards ECF by the labels may influence future “coopetition strategies” for independent labels, as they seek to navigate the changing industry dynamics. Originality/value This paper is the first study to empirically explore the predominantly under-researched area of ECF implementation in the record industry in terms of marketing and financial consequences for artists and labels. </jats:sec
How User‐centric Innovation is Affecting Stakeholder Marketing Strategies: Exploratory Findings from the Music Industry
This paper empirically explores how user‐centric innovation (UCI) in the music industry is affecting how key stakeholder groups are approaching and developing their marketing (and associated management) strategies. The three‐stage interview‐based research methodology consisted of 52 semi‐structured in‐depth interviews with UCI experts and artist managers, as well as representatives from major record labels. The findings make four substantial contributions to theory and practice in the interrelated fields of UCI, marketing and the music industry. First, they provide practical and pragmatic insights for industry practitioners on how different UCI marketing approaches are affecting their management strategies. Second, they take steps towards answering many of the identified gaps in research and knowledge relating to the concept of UCI. Third, they present theoretical models as a foundation for which new UCI marketing theory can be built upon. Last, they offer directions for future research to advance our empirical findings.</jats:p
The effects of dust in simple environments: Large Magellanic Cloud HII regions
We investigate the effects of dust on Large Magellanic Cloud (LMC) HII region
spectral energy distributions using arcminute-resolution far-ultraviolet (FUV),
H-alpha, far-infrared (FIR), and radio images. Widely-used indicators of the
amount of light lost to dust (attenuation) at H-alpha and in the FUV correlate
with each other, although often with substantial scatter. There are two
interesting systematic discrepancies. First, H-alpha attenuations estimated
from the Balmer decrement are lower than those estimated from the
H-alpha-to-thermal radio luminosity ratio. Our data, at this stage, cannot
unambiguously identify the source of this discrepancy. Second, the attenuation
at 1500 angstroms and UV spectral slope, beta, correlate, although the slope
and scatter are substantially different from the correlation first derived for
starbursting galaxies by Calzetti et al. Combining our result with those of
Meurer et al. for ultra-luminous infrared galaxies and Calzetti et al. for
starbursting galaxies, we conclude that no single relation between beta and
1500 angstrom attenuation is applicable to all star-forming systems.Comment: 15 pages; 11 embedded postscript figures; 1 GIF figure; to appear in
ApJ on 20 January 2002, vol. 565, no. 1. Section 5.1 (the discussion of the
discrepancies between Balmer-derived and Radio-derived H alpha attenuations)
has changed considerably to take into account small number statistics for
high-mass stars in the model HII region IMFs. The abstract and conclusions
have been modifie
Computing the everyday: social media as data platforms
We conceive social media platforms as sociotechnical entities that variously shape user platform involvement and participation. Such shaping develops along three fundamental data operations that we subsume under the terms of encoding, aggregation, and computation. Encoding entails the engineering of user platform participation along narrow and standardized activity types (e.g., tagging, liking, sharing, following). This heavily scripted platform participation serves as the basis for the procurement of discrete and calculable data tokens that are possible to aggregate and, subsequently, compute in a variety of ways. We expose these operations by investigating a social media platform for shopping. We contribute to the current debate on social media and digital platforms by describing social media as posttransactional spaces that are predominantly concerned with charting and profiling the online predispositions, habits, and opinions of their user base. Such an orientation sets social media platforms apart from other forms of mediating online interaction. In social media, we claim, platform participation is driven toward an endless online conversation that delivers the data footprint through which a computed sociality is made the source of value creation and monetization
Realising the European network of biodosimetry: RENEB-status quo
Creating a sustainable network in biological and retrospective dosimetry that involves a large number of experienced laboratories throughout the European Union (EU) will significantly improve the accident and emergency response capabilities in case of a large-scale radiological emergency. A well-organised cooperative action involving EU laboratories will offer the best chance for fast and trustworthy dose assessments that are urgently needed in an emergency situation. To this end, the EC supports the establishment of a European network in biological dosimetry (RENEB). The RENEB project started in January 2012 involving cooperation of 23 organisations from 16 European countries. The purpose of RENEB is to increase the biodosimetry capacities in case of large-scale radiological emergency scenarios. The progress of the project since its inception is presented, comprising the consolidation process of the network with its operational platform, intercomparison exercises, training activities, proceedings in quality assurance and horizon scanning for new methods and partners. Additionally, the benefit of the network for the radiation research community as a whole is addressed
Impaired Sprouting and Axonal Atrophy in Cerebellar Climbing Fibres following In Vivo Silencing of the Growth-Associated Protein GAP-43
The adult mammalian central nervous system has a limited ability to establish new connections and to recover from traumatic or degenerative events. The olivo-cerebellar network represents an excellent model to investigate neuroprotection and repair in the brain during adulthood, due to its high plasticity and ordered synaptic organization. To shed light on the molecular mechanisms involved in these events, we focused on the growth-associated protein GAP-43 (also known as B-50 or neuromodulin). During development, this protein plays a crucial role in growth and in branch formation of neurites, while in the adult it is only expressed in a few brain regions, including the inferior olive (IO) where climbing fibres (CFs) originate. Following axotomy GAP-43 is usually up-regulated in association with regeneration. Here we describe an in vivo lentiviral-mediated gene silencing approach, used for the first time in the olivo-cerebellar system, to efficiently and specifically downregulate GAP-43 in rodents CFs. We show that lack of GAP-43 causes an atrophy of the CF in non-traumatic conditions, consisting in a decrease of its length, branching and number of synaptic boutons. We also investigated CF regenerative ability by inducing a subtotal lesion of the IO. Noteworthy, surviving CFs lacking GAP-43 were largely unable to sprout on surrounding Purkinje cells. Collectively, our results demonstrate that GAP-43 is essential both to maintain CFs structure in non-traumatic condition and to promote sprouting after partial lesion of the IO
GATA3 Expression Is Decreased in Psoriasis and during Epidermal Regeneration; Induction by Narrow-Band UVB and IL-4
Psoriasis is characterized by hyperproliferation of keratinocytes and by
infiltration of activated Th1 and Th17 cells in the (epi)dermis. By expression
microarray, we previously found the GATA3 transcription factor significantly
downregulated in lesional psoriatic skin. Since GATA3 serves as a key switch in
both epidermal and T helper cell differentiation, we investigated its function
in psoriasis. Because psoriatic skin inflammation shares many characteristics of
epidermal regeneration during wound healing, we also studied GATA3 expression
under such conditions
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Redirecting research efforts on the diversification-performance linkage: The search for synergy
We review the literature on the diversification-performance (D-P) relationship to a) propose that the time is ripe for a renewed attack on understanding the relationship between diversification and firm performance, and b) outline a new approach to attacking the question. Our paper makes four main contributions. First, through a review of the literature we establish the inherent complexities in the D-P relationship and the methodological challenges confronted by the literature in reaching its current conclusion of a non-linear relationship between diversification and performance. Second, we argue that to better guide managers the literature needs to develop along a complementary path – whereas past research has often focused on answering the big question of does diversification affect firm performance, this second path would focus more on identifying the precise micro-mechanisms through which diversification adds or subtracts value. Third, we outline a new approach to the investigation of this topic, based on (a) identifying the precise underlying mechanisms through which diversification affects performance; (b) identifying performance outcomes that are “proximate” to the mechanism that the researcher is studying, and (c) identifying an appropriate research design that can enable a causal claim. Finally, we outline a set of directions for future research
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