The effect of the environment on the Faber Jackson relation

We investigate the effect of the environment on the Faber Jackson (FJ) relation, using a sample of 384 nearby elliptical galaxies and estimating objectively their environment on the typical scale of galaxy clusters. We show that the intrinsic scatter of the FJ is significantly reduced when ellipticals in high density environments are compared to ellipticals in low density ones. This result, which holds on a limited range of overdensities, is likely to provide an important observational link between scaling relations and formation mechanisms in galaxies.Comment: accepted by Ap

A Dialog on the First 20 Years of PML Research and the Next 20 Ahead

This introductory article has been written in the form of a conversation between Pier Paolo Pandolfi, Director of the Cancer Center of Beth Israel Deaconess Medical Center in Boston, and Rosa Bernardi, a former post-doctoral fellow in the laboratory of Dr. Pandolfi, now principal investigator at San Raffaele Scientific Institute in Milan, Italy. We have chosen this atypical review format because we want to offer to our readers a more direct and personal perspective on the first 20 years of research over the promyelocytic leukemia gene. This article begins as an interview, but soon transforms into a dialog where we exchange our thoughts on a number of issues around the past, present, and future research over the biology of PML. We were particularly keen on emphasizing the aspects that we find most interesting or challenging, therefore, we warn our readers that this will not be a comprehensive essay but rather a very personal view of what has been, is, and will be exciting and interesting in the PML world, in our opinion

“Se le lettere e la dottrina frutta mai nulla, ciò è in virtù non della verità, ma dell’impostura”. Sulla fertilità concettuale e altri aspetti rivelatori delle Bullshit come Dissoi Logoi

Questo contributo teorico propone una prospettiva innovativa nel dibattito sul concetto di “bullshit”. L’ipotesi principale è che la vaghezza sia un elemento fondamentale delle bullshit, che si focalizza sull’attività. In questo modo si supera il dibattito in letteratura che mette al centro o l’intenzionalità dell’enunciatore o la struttura e il contenuto degli enunciati. Si sostiene inoltre che la vaghezza non debba essere considerata come un limite, ma come un’opportunità per comprendere situazioni comunicative complesse. Questo differente approccio, basato sulla tradizione pragmatista, supera alcuni limiti evidenziati in letteratura, aprendo la strada a una comprensione più approfondita del fenomeno delle bullshit. Offre inoltre una risposta esaustiva ad alcuni quesiti di Frankfurt e riconosce il lato “produttivo” delle bullshit, adattandosi meglio a molteplici circostanze quotidiane. Un approccio pragmatista al fenomeno-bullshit basato sulla vaghezza offre una maggiore comprensione di fenomeni complessi di comunicazione senza cadere nel “paradigma della sincerità” evidenziato da Frankfurt

Il fallimento di una vita inabituale: Henry James e la costruzione della «nostra eroina» Isabel Archer

This article aims to raise crucial aspects of the philosophy of habit found in late 19th-century literature, particularly through an examination of Henry James’ portrayal of his character Isabel Archer. This goal is pursued through the analysis of two interconnected aspects forming the theoretical core of this contribution. Firstly, the focus is on Isabel Archer’s psychological depiction as a fundamental contribution of the English and American literature on the theme of habit, especially during the latter half of the 19th century. By contextualizing James’ work, exploring links to Peirce’s pragmatist philosophy and habit theory, the centrality of habit reflection in the psychological structuring of characters, interwoven with philosophical and narrative theories of individuality, is revealed. Furthermore, this reflection provides interpretative keys to understanding Henry James’ narrative choices concerning Isabel’s fate in the novel. Then this article directly specifically examines the construction of Isabel’s self which unfolds through the entire narrative events. The interpretative hypothesis guiding the investigation focuses on the connection between Isabel’s attempts to conduct life without habit and the resulting errors in judgment. To support this hypothesis, the importance of comparing key characters such as Gilbert Osmond and Madame Merle is highlighted. Through the narrative, it will emerge a peculiar ontological structure of the concept of habit. Moreover, through the psychological portraits in the novel, a critical exploration of James’ idea of individuality arises — acknowledging social dynamics and the ontological force of habit, rejecting the dichotomy represented by an optimistic individualism and a degenerate conventional life. The conclusion asserts that Isabel’s pursuit of an unhabitual life inevitably leads to failure. The solution does not lie in a rigid, conventional, dichotomous view of habit. Instead, James argues for a dynamic, relational view of habit: a fundamental aspect of being that must be acknowledged to understand the mechanisms that lead us from the variety of possibilities to the limited “actualities” of life. Through these two interrelated perspectives, the article aims to illuminate the psychological depth of Isabel Archer’s character, demonstrating how her story represents a cornerstone in the broader discussion of the nature and evolution of habit in 19th- century literature. From that, it sets the stage for a more comprehensive discussion on habit’s role in shaping characters and narratives during this historical period.This article aims to raise crucial aspects of the philosophy of habit found in late 19th-century literature, particularly through an examination of Henry James’ portrayal of his character Isabel Archer. This goal is pursued through the analysis of two interconnected aspects forming the theoretical core of this contribution. Firstly, the focus is on Isabel Archer’s psychological depiction as a fundamental contribution of the English and American literature on the theme of habit, especially during the latter half of the 19th century. By contextualizing James’ work, exploring links to Peirce’s pragmatist philosophy and habit theory, the centrality of habit reflection in the psychological structuring of characters, interwoven with philosophical and narrative theories of individuality, is revealed. Furthermore, this reflection provides interpretative keys to understanding Henry James’ narrative choices concerning Isabel’s fate in the novel. Then this article directly specifically examines the construction of Isabel’s self which unfolds through the entire narrative events. The interpretative hypothesis guiding the investigation focuses on the connection between Isabel’s attempts to conduct life without habit and the resulting errors in judgment. To support this hypothesis, the importance of comparing key characters such as Gilbert Osmond and Madame Merle is highlighted. Through the narrative, it will emerge a peculiar ontological structure of the concept of habit. Moreover, through the psychological portraits in the novel, a critical exploration of James’ idea of individuality arises — acknowledging social dynamics and the ontological force of habit, rejecting the dichotomy represented by an optimistic individualism and a degenerate conventional life. The conclusion asserts that Isabel’s pursuit of an unhabitual life inevitably leads to failure. The solution does not lie in a rigid, conventional, dichotomous view of habit. Instead, James argues for a dynamic, relational view of habit: a fundamental aspect of being that must be acknowledged to understand the mechanisms that lead us from the variety of possibilities to the limited “actualities” of life. Through these two interrelated perspectives, the article aims to illuminate the psychological depth of Isabel Archer’s character, demonstrating how her story represents a cornerstone in the broader discussion of the nature and evolution of habit in 19th- century literature. From that, it sets the stage for a more comprehensive discussion on habit’s role in shaping characters and narratives during this historical period

Bone Marrow Endosteal Mesenchymal Progenitors Depend on HIF Factors for Maintenance and Regulation of Hematopoiesis

Summary Maintenance and differentiation of hematopoietic stem cells (HSCs) is regulated through cell-autonomous and non-cell-autonomous mechanisms within specialized bone marrow microenvironments. Recent evidence demonstrates that signaling by HIF-1α contributes to cell-autonomous regulation of HSC maintenance. By investigating the role of HIF factors in bone marrow mesenchymal progenitors, we found that murine endosteal mesenchymal progenitors express high levels of HIF-1α and HIF-2α and proliferate preferentially in hypoxic conditions ex vivo. Inactivation of either HIF-1α or HIF-2α dramatically affects their phenotype, propagation, and differentiation. Also, downregulation of HIF factors provokes an increase in interferon-responsive genes and triggers expansion and differentiation of hematopoietic progenitors by a STAT1-mediated mechanism. Interestingly, in conditions of demand-driven hematopoiesis HIF factors are specifically downregulated in mesenchymal progenitors in vivo. In conclusion, our findings indicate that HIF factors also regulate hematopoiesis non-cell-autonomously by preventing activation of a latent program in mesenchymal progenitors that promotes hematopoiesis

The history of star formation and mass assembly in early-type galaxies

We define a volume limited sample of over 14,000 early-type galaxies (ETGs) selected from data release six of the Sloan Digital Sky Survey. The density of environment of each galaxy is robustly measured. By comparing narrow band spectral line indices with recent models of simple stellar populations (SSPs) we investigate trends in the star formation history as a function of galaxy mass (velocity dispersion), density of environment and galactic radius. We find that age, metallicity and alpha-enhancement all increase with galaxy mass and that field ETGs are younger than their cluster counterparts by ~2 Gyr. We find negative radial metallicity gradients for all masses and environments, and positive radial age gradients for ETGs with velocity dispersion over 180 km/s. Our results are qualitatively consistent with a relatively simple picture for ETG evolution in which the low-mass halos accreted by a proto-ETG contained not only gas but also a stellar population. This fossil population is preferentially found at large radii in massive ETGs because the stellar accretions were dissipationless. We estimate that the typical, massive ETG should have been assembled at z < 3.5. The process is similar in the cluster and the field but occurred earlier in dense environments.Comment: 5 pages, 2 figures. Submitted to MNRA

The age-redshift relation for Luminous Red Galaxies in the Sloan Digital Sky Survey

We present a detailed analysis of 17,852 quiescent, Luminous Red Galaxies (LRGs) selected from Sloan Digital Sky Survey (SDSS) Data Release Seven (DR7) spanning a redshift range of 0.0 < z < 0.4. These galaxies are co-added into four equal bins of velocity dispersion and luminosity to produce high signal-to-noise spectra (>100A^{-1}), thus facilitating accurate measurements of the standard Lick absorption-line indices. In particular, we have carefully corrected and calibrated these indices onto the commonly used Lick/IDS system, thus allowing us to compare these data with other measurements in the literature, and derive realistic ages, metallicities ([Z/H]) and alpha-element abundance ratios ([alpha/Fe]) for these galaxies using Simple Stellar Population (SSP) models. We use these data to study the relationship of these galaxy parameters with redshift, and find little evidence for evolution in metallicity or alpha-elements (especially for our intermediate mass samples). This demonstrates that our subsamples are consistent with pure passive evolving (i.e. no chemical evolution) and represent a homogeneous population over this redshift range. We also present the age-redshift relation for these LRGs and clearly see a decrease in their age with redshift (5 Gyrs over the redshift range studied here) which is fully consistent with the cosmological lookback times in a concordance Lambda CDM universe. We also see that our most massive sample of LRGs is the youngest compared to the lower mass galaxies. We provide these data now to help future cosmological and galaxy evolution studies of LRGs, and provide in the appendices of this paper the required methodology and information to calibrate SDSS spectra onto the Lick/IDS system.Comment: 26 pages, with several appendices containing data. Accepted for publication in MNRA

The Faber-Jackson relation for early-type galaxies: Dependence on the magnitude range

We take a sample of early-type galaxies from the Sloan Digital Sky Survey (SDSS-DR7, $\sim$ 90 000 galaxies) spanning a range of approximately 7 $mag$ in both $g$ and $r$ filters and analyse the behaviour of the Faber-Jackson relation parameters as functions of the magnitude range. We calculate the parameters in two ways: i) We consider the faintest (brightest) galaxies in each sample and we progressively increase the width of the magnitude interval by inclusion of the brighter (fainter) galaxies (increasing-magnitude-intervals), and ii) we consider narrow-magnitude intervals of the same width ($\Delta M = 1.0$ $mag$) over the whole magnitude range available (narrow-magnitude-intervals). Our main results are that: i) in both increasing and narrow-magnitude-intervals the Faber-Jackson relation parameters change systematically, ii) non-parametric tests show that the fluctuations in the values of the slope of the Faber-Jackson relation are not products of chance variations. We conclude that the values of the Faber-Jackson relation parameters depend on the width of the magnitude range and the luminosity of galaxies within the magnitude range. This dependence is caused, to a great extent by the selection effects and because the geometrical shape of the distribution of galaxies on the $M - \log (\sigma_{0})$ plane depends on luminosity. We therefore emphasize that if the luminosity of galaxies or the width of the magnitude range or both are not taken into consideration when comparing the structural relations of galaxy samples for different wavelengths, environments, redshifts and luminosities, any differences found may be misinterpreted.Comment: 15 pages, 5 figures. A&A. Accepte