4,057 research outputs found
L'ingegneria strutturale applicata alla conservazione di monumenti archeologici in area sismica. Il caso studio delle terme-chiesa di Hierapolis di Frigia.
No full textThe present work concerns the prevention and the conservation of the so called Terme-Chiesa. It is part of a bigger project consisting of the proposal of the archeo-seismologic site of Hierapolis.
The analysis of this complex, very peculiar in its morphology, evolution and damage, constituted a research methodology also applicable to monuments technologically different but with the same preservation purpose.
The methodology is based on an interdisciplinary approach, taking into account the requirements of the Italian and international codes. Skills from different areas contributed to the conservation of the structures following the knowledge process and to an integrated design method based on the synergy between technology and historical-archeological conservation.
The complex of the Terme-Chiesa has been analyzed from a historical, archeological and architectonical point of view. Graphical representation helped understanding the construction techniques, as well as the conservation conditions.
In-situ experimental campaigns were carried out in2014 and 2015. Those investigations included several surveys and non obtrusive investigations such as: endoscopy inspections, sonic and dynamic identification tests.
Seismic analyses and geophysical studies provided further information, such as the properties of the soil. This information contributed identifying the fault system which characterizes the Hierapolis site.
The geophysical data was also crossed with the engineering evaluation of structural damage suffered by the monument and related to past ground motion.
Samples of mortar and travertine stone were drawn. Future analysis on these samples will show evolutionary states and will give information about possible restoration performed on some parts of the building in the past.
Moreover, analytical and numerical modeling valuations were performed.
Starting from the results obtained from the dynamic identification, the Finite Element Model (FEM) was calibrated and validated. To better understand the dynamic behavior of the structure, a Discrete Element Model (DEM) was also implemented, through non-linear dynamic analyzes based on real and artificial accelerograms
Claudia Ceppi, Stefano Spagnolo ,Massimo Monteleone, Giovanna Marson, Luca Zagolin, Salvatore Patti, Furio Forni. 2016. Le combustioni all’aperto, importanti sorgenti di pm10 e composti tossicologicamente rilevanti. In: Qualità dell’ambiente urbano, XII Rapporto. Focus su inquinamento atmosferico nelle aree urbane ed effetti sulla salute. pp. 67-80. Stato dell’Ambiente 68/2016. Ministero dell’Ambiente ed ANCI.
No full textUna breve riflessione storica sulla teoria infiammatoria dell’aterosclerosi.
No full textIn the past 20 years several clinical and experimental observations have led to the hypothesis that an inflammatory response can trigger some key processes during the development of atherosclerosis. Here we briefly review, from the historical viewpoint, the inflammatory theory of atherosclerosis, as proposed by the Berliner pathologist Rudolf Virchow in the XIX century. Contrary to this hypothesis, in the same period the Viennese Karl von Rokitansky recognized blood dyscrasia (particularly fibrin-induced alterations) as the promoting factor in the process of atherogenesis. Moreover, we outline the relationship between atherosclerosis and arthritis, by reporting some passages from two scientific works published in the late XIX century, the former by the Italian Achille De Giovanni ("Sull'arterite. Sue forme cliniche e sua patogenesi", 1882) and the latter by the French Theophile Guyot ("L'arthritis. Maladie Constitutionnelle", 1890)
Folding versus charge: understanding selective target recognition by the thrombin aptamers
No full textThe use of nucleic acids as drugs represents a consistently growing approach. Different therapeutical strategies take advantage of the biological and biophysical properties of DNA and RNA to properly modulate activity of selected targets. A peculiar characteristic of these molecules is their structural flexibility which allows them to assume distinct foldings depending upon their sequence and/or environment. During the last twenty years this has led to the theoretical and experimental development of oligonucleotide aptamers, short sequences which can recognize a target with specificity and affinity comparable to antibodies. A leading example is represented by the Thrombin aptamer (15fTBA), a 15-mer DNA selected by its high affinity for the exosite I (fibrinogen binding site) of the coagulation factor. The very stable protein-DNA complex formation is the result of complementarities between the two macromolecules promoted by the aptamer sequence and folding as well as of electrostatic interactions generated by the charge balance at the binding site/s. Here, we investigated the relative role of these contributions and their involvement in defining the biological properties of the resulting complex. Thus we compared the Thrombin binding and inhibition properties of TBA to those of unrelated single stranded oligonucleotides. Additionally, the differences between the two protein exosites were assessed by using 29hTBA, a longer (29-mer) aptamer known to bind exosite II (heparin binding site). A subtle balance of aptamer folding and sequence is shown to cooperate with charge density for effective and selective recognition of exosite I or exosite II by TBAs
Structural and functional characterization of thrombin binding aptamer minor loop
No full textThe thrombin binding aptamer (29hTBA), identified with a SELEX approach, shows a significant affinity for the coagulation factor thrombin by recognizing the protein Exosite II (heparin binding site). The structure of 29hTBA consists of a G-quadruplex core flanked by two partially paired terminal strands. Literature data underline that the structure and stability of intramolecular G-quadruplexes can be profoundly influenced by the length and composition of the loops. Here, we investigated the role of the minor loop (10-11) composition by introducing a single A-T mutation at position 11. A comparative structural investigation of the wild type and the mutant aptamers evidenced that this loop is not largely impairing the folding of the G-quadruplex core. Additionally, thrombin binding analysis suggested that this loop is not directly involved in protein binding at exosite II
Claudia Rankine: An Evening with Claudia Rankine
No full textAn initiative of the National Endowment for the Arts in partnership with Arts Midwest, the NEA Big Read broadens our understanding of our world, our communities, and ourselves through the joy of sharing a good book. For NEA Big Read: Hampton Roads, that book is Citizen: An American Lyric.
NEA Big Read: Hampton Roads, the President\u27s Lecture Series, and the President\u27s Task Force on Inclusive Excellence invite you to a powerful evening with Claudia Rankine, the book\u27s author, hosted by Tim Seibles, Poet Laureate for the Commonwealth of Virginia, and opening with readings by local youth poets.
Claudia Rankine has written five collections of poetry, including Citizen: An American Lyric, which was selected for the National Endowment for the Arts\u27 Big Read, and two plays. She also has participated in several video collaborations and edited anthologies including The Racial Imaginary: Writers on Race in the Life of the Mind.
Rankine has received fellowships from the MacArthur and Guggenheim foundations. Citizen won several honors, including the National Book Critics Circle Award for Poetry, the PEN Open Book Award and the NAACP Image Award. Citizen also was the only poetry book to be a New York Times nonfiction bestseller. She is the Frederick Iseman Professor of Poetry at Yale University and chancellor of the Academy of American Poets
DNA, variations on the theme
No full textMolecular biology's central dogma, laid down in 1950s, affirmed that genetic information flows from DNA to RNA to protein synthesis. For a long time, the first element of this logic scheme, DNA, was regarded as inactive molecule with the sole purpose to act as a repository of genetic code. Indeed, the molecular dialogue between DNA and proteins has been generally interpreted as an univocal relationship between an inert partner (nucleic acid) and a versatile one (proteins), that remodels DNA as a clay object. Rather, has been emerged that each kind of interactions between macromolecules requires a mutual structural adaptation and chemical complementarity.
As in Kurosawa’s classic movie “Rashomon” (1950) the same central event, a heinous crime, is recalled from the differing perspective of each character (a bandit, a samurai, samurai’s wife and a woodcutter) this present study aims to highlight some different, but complementary, aspects of the full dynamic repertoire of DNA macromolecules. In the first part of this thesis, I will demonstrate that DNA, according to a peculiar three dimensional arrangement, is not only a simple recipe for proteins production but something more. In particular, I will focus on guanosine quadruplex structure, a not canonical B-form of DNA could be described through multiple points of view.
On one side, synthetic guanosine quadruplex can act as “smart” biomolecules able to recognize multiple targets, with potential implications both as diagnostic as well as therapeutic agent. This short DNA/RNA sequences, called aptamers, according to a unique molecular flexibility, are able to recognize and bind a broad range of targets with specificities reminiscent those exhibited by antibodies. As working model, here I will present a detailed characterization in vitro of not physiological guanosine rich sequences able to bind human thrombin, a protein of physiological and pathological relevance. Our research was aimed to describe the relative role of the structural modules composing their molecular architecture. This allowed us to propose a structure activity relationship of synthetic G quadruplex aptamers, in order to fully rationalize and optimize their binding property.
On the other side, G-quadruplex forming sequences are also found in human genome. Some of them have been described as unique biochemical on/off switch able to regulate tumorigenic pathways.
In particular, the expression of the oncogene c-Myc is controlled through the formation of non–B-form DNA structures within its promoter. The conformational shift of this promoter between a transcription inactive form (G-quadruplex form) to an active one (a canonical double strand form) is strictly regulated by several nuclear proteins. In the second section I’ll present a study concerning the heterologous expression, the purification scheme of the resulting products and the biochemical characterization of the functional domains of human nucleolin, a nucleolar protein that is able to inhibit c-Myc oncogene transcription by a peculiar recognition of its promoter in a G quadruplex form. This approach was pursued to deeper clarify the mechanism of this binding event. Doubtless, this represents a promising goal in order to develop new selective and effective chemotherapy drugs.
Although revolutionary, the idea that genetic information was encoded only by DNA sequence, in a protein-free mechanism has been appeared definitely too simplistic. Indeed, in organisms with nuclei chromosomal DNA is organized along with protein templates (histones), forming a complex called chromatin. This is target of diverse array of posttranslational modifications that modulate the interaction among chromatin-associated proteins, which ultimately dictate dynamic transitions between transcriptionally active (euchromatin) or transcriptionally silent chromatin states (heterochromatin). In the last section, I will focus on the structural insights standing on the recognition event between a modified histone N-terminal tail and a specialized ‘effector’ protein (ORC1b), generally known for its role in pre-replication complex assembly.
The identification of the molecular details that clarify how distinct protein modules are able to recognize specific histone modifications is a critical step to understanding how chromatin dynamics influence fundamental DNA-templated processes such as transcription, DNA recombination and DNA repair. In particular, our results identify the tandem PHD-BAH domains of Arabidopsis thaliana ORC1b as a novel unmethylated-lysine-binding module, thereby establishing the first direct link between histone methylation grade and the epigenetic role of ORC1b, previously known as a transcriptional regulation factor only for a series of specific interactions with silencing regulators
Behavior of Historic Buildings in Zones with Moderate Seismic Activity. Case Study: Banat Region, Romania
No full textAbstractHistoric buildings from seismic zones have recorded important damages after earthquakes. Due to this aspect, in current design codes for consolidations of some countries there are special calculations for historic buildings. The development of the investigation methods for the damages developed in the historic bearing structures revealed the fact that these damages are differentiated by the type and intensity of the earthquake. Information on these different failure modes of the historic bearing structures is not given in the current design codes for zones with medium and reduced seismic activity. In Romania there are no specific provisions for the design of the consolidation works of historic bearing structures, even though there are two important seismic zones: Vrancea region and Banat region. The Vrancea region is characterized by deep earthquakes while the Banat region is characterized by shallow earthquakes. These two types of earthquakes produce different failure modes for similar historic buildings. In this article there are presented specific failure modes of historic buildings such as orthodox churches, catholic churches, synagogues, residential buildings, and aggregate buildings from Banat region which has moderate seismic activity. The evaluation methodology of the seismic vulnerability of buildings from historic centers developed by the University of Padova was confirmed by in situ identification of failure mechanisms recorded in historic bearing structures from Timisoara. There are also presented specific recommendations regarding the design philosophy of the consolidations for zones with moderate seismic activity, by the control of the fundamental requirements for buildings: rigidity and ductility
Portrait of Claudia Lynn Pittman.
No full textHandwritten inscription: Claudia Lynn Pittman, 20 yrs old, Hattiesburg.https://egrove.olemiss.edu/joephoto_c/1129/thumbnail.jp
Homonoia - Concorda - Sammanasya
No full textAnalysis of the divine figures of Homónoia in the Greek pantheon, Concordia in the Roman pantheon, and Sammanasya in the Vedic pantheon. Claudia Santi is the author of Homónoia; Andrzej Gillmeister is the author of Concordia; Antonio Salvati is the author of Sammanasya. As regards Homónoia, the origin of this personified abstraction seems to be traced back to the political debate of Athens in the last 5th century. Maybe it was created by Antiphon as opposed to stásis, both in the meaning of ‘psychic conflict’ and ‘internal political dissensions, civil war’
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