12 resultados para Probus, Marcus Aurelius, Emperor of Rome, 232-282.
em CentAUR: Central Archive University of Reading - UK
Resumo:
A chapter of 6,000 words on books, literary culture, and public and private libraries in the ancient city of Rome
Resumo:
The E3 ligase c-Cbl ubiquitinates protease-activated receptor 2 (PAR(2)), which is required for post-endocytic sorting of PAR(2) to lysosomes, where degradation arrests signaling. The mechanisms of post-endocytic sorting of ubiquitinated receptors are incompletely understood. Here, we investigated the role of hepatocyte growth factor-regulated tyrosine kinase substrate (HRS), in post-endocytic sorting and signaling of PAR(2). In HEK-PAR(2) cells, PAR(2) activating peptide (PAR(2)-AP) induced PAR(2) trafficking from the cell surface to early endosomes containing endogenous HRS, and then to lysosomes. HRS overexpression or knockdown with small interfering RNA caused formation of enlarged HRS-positive endosomes, where activated PAR(2) and c-Cbl accumulated, and PAR(2) failed to traffic to lysosomes. Overexpression of HRS prevented PAR(2)-AP-induced degradation of PAR(2), as determined by Western blotting. Overexpression of HRS mutant lacking an ubiquitin-binding motif similarly caused retention of PAR(2) in enlarged endosomes. Moreover, HRS overexpression or knockdown caused retention of ubiquitin-resistant PAR(2)Delta14K/R in enlarged HRS-containing endosomes, preventing recycling and resensitization of PAR(2)Delta14K/R. HRS overexpression or knockdown similarly prevented lysosomal trafficking and recycling of calcitonin receptor-like receptor, a non-ubiquitinated receptor that traffics to lysosomes after sustained activation and recycles after transient activation. Thus, HRS plays a critically important role in the post-endocytic sorting of single receptors, PAR(2) and CLR, to both degradative and recycling pathways. This sorting role for HRS is independent of its ubiquitin-interacting motif, and it can regulate trafficking of both ubiquitinated and non-ubiquitinated PAR(2) and non-ubiquitinated CLR. The ultimate sorting decision to degradative or recycling pathways appears to occur downstream from HRS.
Resumo:
Calcitonin receptor-like receptor (CLR) and the receptor activity-modifying protein 1 (RAMP1) comprise a receptor for calcitonin gene-related peptide (CGRP). Although CGRP induces endocytosis of CLR/RAMP1, little is known about post-endocytic sorting of these proteins. We observed that the duration of stimulation with CGRP markedly affected post-endocytic sorting of CLR/RAMP1. In HEK and SK-N-MC cells, transient stimulation (10(-7) M CGRP, 1 h), induced CLR/RAMP1 recycling with similar kinetics (2-6 h), demonstrated by labeling receptors in living cells with antibodies to extracellular epitopes. Recycling of CLR/RAMP1 correlated with resensitization of CGRP-induced increases in [Ca(2+)](i). Cycloheximide did not affect resensitization, but bafilomycin A(1), an inhibitor of vacuolar H(+)-ATPases, abolished resensitization. Recycling CLR and RAMP1 were detected in endosomes containing Rab4a and Rab11a, and expression of GTPase-defective Rab4aS22N and Rab11aS25N inhibited resensitization. After sustained stimulation (10(-7) M CGRP, >2 h), CLR/RAMP1 trafficked to lysosomes. RAMP1 was degraded approximately 4-fold more rapidly than CLR (RAMP1, 45% degradation, 5 h; CLR, 54% degradation, 16 h), determined by Western blotting. Inhibitors of lysosomal, but not proteasomal, proteases prevented degradation. Sustained stimulation did not induce detectable mono- or polyubiquitination of CLR or RAMP1, determined by immunoprecipitation and Western blotting. Moreover, a RAMP1 mutant lacking the only intracellular lysine (RAMP1K142R) internalized and was degraded normally. Thus, after transient stimulation with CGRP, CLR and RAMP1 traffic from endosomes to the plasma membrane, which mediates resensitization. After sustained stimulation, CLR and RAMP1 traffic from endosomes to lysosomes by ubiquitin-independent mechanisms, where they are degraded at different rates.
Resumo:
"Snapshot" of the city of Rome around 1600, with relation to the visual arts, especially the work of artists and architects such as Caravaggio, Annibale Carracci, Rubes, the Cavaliere d'Arpino, Federico Zuccaro, Giacomo della Porta and Carlo Maderno, as well as their patrons (Aldobrandini, Farnese, Giustinani, Mattei, Del Monte).
Resumo:
European air quality legislation has reduced emissions of air pollutants across Europe since the 1970s, affecting air quality, human health and regional climate. We used a coupled composition-climate model to simulate the impacts of European air quality legislation and technology measures implemented between 1970 and 2010. We contrast simulations using two emission scenarios; one with actual emissions in 2010 and the other with emissions that would have occurred in 2010 in the absence of technological improvements and end-of-pipe treatment measures in the energy, industrial and road transport sectors. European emissions of sulphur dioxide, black carbon (BC) and organic carbon in 2010 are 53%, 59% and 32% lower respectively compared to emissions that would have occurred in 2010 in the absence of legislative and technology measures. These emission reductions decreased simulated European annual mean concentrations of fine particulate matter(PM2.5) by 35%, sulphate by 44%, BC by 56% and particulate organic matter by 23%. The reduction in PM2.5 concentrations is calculated to have prevented 80 000 (37 000–116 000, at 95% confidence intervals) premature deaths annually across the European Union, resulting in a perceived financial benefit to society of US$232 billion annually (1.4% of 2010 EU GDP). The reduction in aerosol concentrations due to legislative and technology measures caused a positive change in the aerosol radiative effect at the top of atmosphere, reduced atmospheric absorption and also increased the amount of solar radiation incident at the surface over Europe. We used an energy budget approximation to estimate that these changes in the radiative balance have increased European annual mean surface temperatures and precipitation by 0.45 ± 0.11 °C and by 13 ± 0.8 mm yr−1 respectively. Our results show that the implementation of European legislation and technological improvements to reduce the emission of air pollutants has improved air quality and human health over Europe, as well as having an unintended impact on the regional radiative balance and climate.
Resumo:
The fifteenth century saw a striking upturn in the number of texts from foreign vernaculars that were translated into Irish. Indeed, one might go so far as to speak in terms of a ‘translation trend’ in Ireland during the mid to late fifteenth century. A notable feature of this trend is that a particularly high number of these Irish translations are of romances; contextual and textual evidence suggests that the original exemplars for many of these translated texts appear to have come from England, though not all of them were necessarily in English. Irish translations of eight romances have survived to the present day: Guy of Warwick; Bevis of Hampton; La Queste de Saint Graal; Fierabras; Caxton’s Recuyell of the Histories of Troie; William of Palerne; the Seven Sages of Rome; and Octavian. This paper addresses two aspects of these texts of particular relevance to romance scholars who do not work within the sphere of Celtic studies. Firstly, it argues that certain aspects of the dissemination and reception of romance in Ireland are quite distinctive. Manuscript and textual evidence suggests that the religious orders, particularly the Franciscans, seem to have played a role in the importation and translation of these narratives. Secondly, examination of the Irish versions of romance tends to bear out an observation made by Flower many years ago, but not pursued by subsequent scholars: ‘texts of an unusual kind were current in Ireland, and it may be that interesting discoveries are to be made here’. Certain narrative features of several of these Irish translations diverge from all the surviving versions of the relevant romance in other languages and may witness to a variant exemplar that has since been lost from its own linguistic corpus.
Resumo:
Although principally produced by the pancreas to degrade dietary proteins in the intestine, trypsins are also expressed in the nervous system and in epithelial tissues, where they have diverse actions that could be mediated by protease-activated receptors (PARs). We examined the biological actions of human trypsin IV (or mesotrypsin) and rat p23, inhibitor-resistant forms of trypsin. The zymogens trypsinogen IV and pro-p23 were expressed in Escherichia coli and purified to apparent homogeneity. Enteropeptidase cleaved both zymogens, liberating active trypsin IV and p23, which were resistant to soybean trypsin inhibitor and aprotinin. Trypsin IV cleaved N-terminal fragments of PAR(1), PAR(2), and PAR(4) at sites that would expose the tethered ligand (PAR(1) = PAR(4) > PAR(2)). Trypsin IV increased [Ca(2+)](i) in transfected cells expressing human PAR(1) and PAR(2) with similar potencies (PAR(1), 0.5 microm; PAR(2), 0.6 microm). p23 also cleaved fragments of PAR(1) and PAR(2) and signaled to cells expressing these receptors. Trypsin IV and p23 increased [Ca(2+)](i) in rat dorsal root ganglion neurons that responded to capsaicin and which thus mediate neurogenic inflammation and nociception. Intraplantar injection of trypsin IV and p23 in mice induced edema and granulocyte infiltration, which were not observed in PAR (-/-)(1)(trypsin IV) and PAR (-/-)(2) (trypsin IV and p23) mice. Trypsin IV and p23 caused thermal hyperalgesia and mechanical allodynia and hyperalgesia in mice, and these effects were absent in PAR (-/-)(2) mice but maintained in PAR (-/-)(1) mice. Thus, trypsin IV and p23 are inhibitor-resistant trypsins that can cleave and activate PARs, causing PAR(1)- and PAR(2)-dependent inflammation and PAR(2)-dependent hyperalgesia.
Resumo:
This thesis aims to investigate the development and functions of public libraries in Rome and the Roman world. After a preface with maps of libraries in Rome, Section I discusses the precursors for public library provision in the private book collections of Republican Rome, and their transfer into the public domain with the first public libraries of Asinius Pollio and Augustus. Section II contains three 'case studies' of public libraries' different roles. The Augustan library programme is used in Ch.II.l to examine the role of imperial public libraries in literary life and the connections between Rome's libraries and those of Alexandria. Chapter II.2 concentrates on the libraries of Trajan's Forum to explore the intersection of imperial public libraries and monumental public architecture. This chapter responds to an important recent article by arguing for the continued identification of the Forum's libraries with twin brick buildings at its northern end, and suggests a series of correspondences between these libraries and its other monumental components. The conclusions of this chapter are important when considering the public libraries of the wider empire, several of which seem to have been inspired by the Trajanic libraries. Chapter II.3 considers imperial public libraries and leisure by looking at the evidence for libraries within bath-house complexes, concluding that their presence there is consistent with the archaeological and epigraphic evidence and fits in well with what we know of the intellectual and cultural life of these structures. Section III examines various aspects of the practical function of Roman public libraries: their contents (books and archives), division into Latin and Greek sections, provisions for shelving and cataloguing, staff, usership, architectural form, decoration, and housing of works of art. The picture that emerges is of carefully designed and functional buildings intended to sustain public, monumental, and practical functions. Section IV uses a variety of texts to examine the way in which libraries were viewed and used. Ch. IV. 1 discusses the evidence for use of libraries by scholars and authors such as Gellius, Galen, Josephus, and Apuleius. Ch. IV.2 examines parallels between library collections and compendious encyclopaedic elements within Roman literature and considers how library collections came to be canon-forming institutions and vehicles for the expression of imperial approval or disapproval towards authors. The channels through which this imperial influence flowed are investigated in Ch. IV.3, which looks at the directors and staff of the public libraries of Rome. The final section (V) of the thesis concerns public libraries outside the city of Rome. Provincial libraries provide a useful case study in 'Romanisation': they reveal a range of influences and are shown to embody local, personal, and metropolitan imperial identities. There follows a brief conclusion, and a bibliography. There are also five appendices of numismatic and epigraphic material discussed in the text. This material has not been adequately or completely gathered elsewhere and is intended to assist the reader; where appropriate it includes illustrations, transcriptions, and translations.