Radio spectra of a sample of X-ray selected BL Lacs

We present simultaneous multifrequency radio observations for a complete subsample of 26 XBLs from the Einstein Extended Medium-Sensitivity Survey, obtained with the Very Large Array (VLA). Spectra are computed using fluxes at 20, 6 and 3.6 cm. Unlike many radio selected samples, the EMSS did not impose any criterion on the radio spectrum to identify BL Lac objects. It is therefore possible to investigate the intrinsic radio spectral slope distribution and to determine the effect produced by this selection criterion. We find that 15% of the observed objects do not meet the flat-spectrum criterion imposed on some other BL Lac samples. A dataset that includes non-simultaneous data (that are also taken with different VLA configurations) shows an even higher percentage of steep spectrum sources. This effect can be ascribed to a larger fraction of extended flux detected with the more compact VLA configuration.Possible biases introduced by the flat--radio-spectrum criterion in the radio-selected BL Lac samples cannot explain the discrepancies observed in the evolutionary properties of Radio and X-ray selected samples of BL Lacs.Comment: 9 pages, 5 figures, to be published in Astronomy and Astrophysic

BL Lac evolution revisited

BL Lac objects are an elusive and rare class of active galactic nuclei. For years their evolutionary behavior has appeared inconsistent with the trend observed in the population of AGN at large. The so-called ``negative'' evolution implies that BL Lacs were either less or fainter in the past. This effect is stronger for BL Lacs selected in X-ray surveys. We have investigated if one of the selection criteria, namely the flat-radio spectrum (imposed on the Radio-selected but not on the X-ray-selected samples), might explain the different evolutionary trend.Comment: Proceedings of "Multiwavelength AGN Surveys", Cozumel, Dec 200

DISTRIBUTION OF CATECHOLAMINERGIC NEUROTRANSMITTERS AND RELATED RECEPTORS IN HUMAN BRONCHUS-ASSOCIATED LYMPHOID TISSUE

Background: The functions of the bronchus-associated lymphoid tissue (BALT) are under the control of the autonomic nervous system ( sympathetic and parasympathetic nerve fibers). Objectives: The relationships between the adrenergic nerve fibers and beta-adrenergic receptors were studied in the human BALT with the aim to demonstrate a probable neuromodulation. Methods: Morphological observations ( staining with hematoxylineosin and scanning electron microscopy images) were carried out on samples of human BALT harvested during autopsies. Moreover, histochemical staining for norepinephrine ( adrenaline = adrenergic nerve fibers) as well as for other catecholamines was performed. Finally, beta-adrenergic receptors were stained by means of a beta-blocking, radiolabeled drug ( pindolol I-125). All our data were submitted to morphometric analysis ( quantitative analysis of images and statistical analysis of data). Results: Our results provide direct evidence of the presence and distribution of catecholaminergic nerve fibers and related beta-adrenergic receptors in BALT. beta-Adrenergic receptors are present above all in the most richly innervated part of the BALT, and are, therefore, in close relationship with their related adrenergic nerve fibers. Conclusions: Studies on the distribution of adrenergic neurotransmitters and related beta-adrenergic receptors in the human BALT are the first step for the demonstration of a probable neuromodulation of BALT. Copyright (C) 2004 S. Karger AG, Basel

Local/global: amateur cinema and new forms of valorization in archival film festivals

This paper will focus on the new landscapes of valorization and access to amateur/small gauge films within the archival film festival context. Archival small gauge film festivals present themselves as something completely different from those festivals dedicated to amateur and experimental cinema in the past, mainly because their goal is to valorize assets that have been deposited in specialized archives from the 1980s onwards. This film heritage is composed not only by the products of serious amateurs, but also by home movies and experimental films. We will start from the cases of Home Movie Day, a project developed in 2002 by archivists, cura- tors and film historians in the US, Archivio Aperto in Italy, and Orphan Film Symposium, founded in 1999. Throughout the years they have become a blueprint for archival small gauge film festivals and a label to which different experiences refer: small archival film festivals; meeting activities where the broader field of ‘non-thea- trical film’ is addressed; the Home Movie Marathon, a live streaming in which amateur films from all across the world are screened, etc. Furthermore, we will focus on examples from the European context, such as Archivio Aperto and its recent developments with the Memoryscapes digital platform

Evidence of a kallikrein inhibitor in human kidney. A new ring of the kallikrein-renin-angiotensin-aldosterone chain

By means of immunohistochemical reactions, the authors proved the inhibitor II-related immunoreactivity in distal convoluted tubules of human kidney. A sharp inhibitor II-related immunoreactivity was also present in the blood vessels' wall. On the contrary, in the wall of proximal tubules and glomeruli only low reactivity was found. The demonstration of an inhibitor II-related immunoreactivity in the distal convoluted tubules and vessels of human kidney represents a strong evidence that an inhibitor of kallikrein exists and acts also in humans as an important key in the kallikrein-renin-angiotensin aldosterone chain and hitherto confirms the experimental data of the literature. The proved inhibitor in the human kidney may intervene in the modulation of the kallikrein-kinin system and thus represents a key role in the intrarenal mechanisms related to the blood flow and arterial pressure regulation

¿Barreras o Motivación? Progreso de la Carrera en la Empresa Familiar: La Perspectiva de las Hijas

Women are under-represented in high-level management and administrative positions in family businesses. To date, the research on career motivation remains in the shadow of research on gender barriers. By acknowledging the relation between the two, it is proposed to look holistically at the problem and to empirically examine the relation between motivation, barriers, and position of daughters in family business. By conducting SEM analysis, it was found that motivation to act ethically is positively associated with high positions and that barriers “specific to family business” are negatively related to high positions. This article validates two scales and makes methodological contributions to the stream of research on daughters in family business that to date relies mainly on qualitative studies.Las mujeres están subrepresentadas en los puestos directivos y de gestión de alto nivel en las empresas familiares. Hasta la fecha, la investigación sobre la motivación para la carrera permanece en las sombras de la investigación sobre barreras de género. Al reconocer la relación entre los dos, se propone mirar holísticamente al problema y examinar empíricamente la relación entre la motivación, las barreras, y la posición de las hijas en la empresa familiar. Al realizar el análisis SEM, se encontró que la motivación para actuar éticamente está asociada positivamente con posiciones altas y que las barreras “específicas para las empresas familiares” están relacionadas negativamente con las altas posiciones. Este artículo valida dos escalas y realiza contribuciones metodológicas a la corriente de investigación sobre hijas en empresas familiares que hasta la fecha se basan principalmente en estudios cualitativos

Glycosaminoglycans in the human cornea: age-related changes

Abstract AIM: To investigate possible age-related changes in glycosaminoglycans (GAGs) in the human cornea. The substances today called GAGs were previously referred to as mucopolysaccharides. METHODS: Samples of human cornea were taken from 12 younger (age 21 ± 1.2) and 12 older (age 72 ± 1.6) male subjects. Samples were weighed, homogenized, and used for biochemical and molecular analyses. All the quantitative results were statistically analyzed. RESULTS: The human cornea appears to undergo age-related changes, as evidenced by our biochemical and molecular results. The total GAG and hyaluronic acid counts were significantly higher in the younger subjects than in the older subjects. The sulfated heavy GAGs, such as chondroitin, dermatan, keratan, and heparan sulfate, were lower in the younger subjects than in the older subjects. DISCUSSION: GAGs of the human cornea undergo numerous age-related changes. Their quantity is significantly altered in the elderly in comparison with younger subjects. GAGs play an important role in age-related diseases of the human cornea

Exploring short intramolecular interactions in alkylaromatic substrates

From proteins and peptides to semiconducting polymers, aliphatic chains on aromatic groups are recurring motifs in macromolecules from very diverse application fields. Fields in which molecular folding and packing determine the macroscopic physical properties that make such advanced materials appealing in the first place. Within each macromolecule, the intrinsic structure of each unit defines how it interacts with its neighbours, ultimately opening up or denying certain backbone conformations. This eventually also determines how macromolecules interact with each other. This account deals specifically with the conformational problem of many common alkylaromatic units, examining the features of an intramolecular interaction involving a side chain with as few as three methylene groups. A set of 23 model compounds featuring an intramolecular interaction between an aliphatic X-H (X = C, N, O, and S) bond and an aromatic ring was considered. Quantitative computational analysis was made possible, thanks to complete basis set extrapolated CCSD(T) calculations and NCI topological analysis, the latter of which revealed an elaborate network of dispersive and steric interactions leading to somewhat unintuitive and unexpected results, such as the higher energetic stability of certain twisted conformational isomers over those with extended side chains. Vicinal covalent effects from polarizing groups and various heteroatoms, along with the occurrence of non-dispersive phenomena, were also investigated. The conclusions drawn from the investigation include a comprehensive set of guidelines intended to aid in the prediction of the most stable conformation for this class of building blocks. Our findings affect a variety of different research fields, including the tailoring of functional materials for organic electronics and photovoltaics, with insights into a rational treatment of conformational disorder, and the study of protein- and peptide-folding preferences, putting an emphasis on peculiar interactions between the backbone and aromatic residues