Selection of primer-template sequences that bind human immunodeficiency virus reverse transcriptase with high affinity

A SELEX (systematic evolution of ligands by exponential enrichment)-based approach was developed to determine whether HIV-RT showed preference for particular primer-template sequences. A 70 nt duplex DNA was designed with 20 nt fixed flanking sequences at the 3′ and 5′ ends and a randomized 30 nt internal sequence. The fixed sequence at the 5′ end contained a BbsI site six bases removed from the randomized region. BbsI cuts downstream of its recognition site generating four base 5′ overhangs with recessed 3′ termini. Cleavage produced a 50 nt template and 46 nt primer with the 3′ terminus within the randomized region. HIV-RT was incubated with this substrate and material that bound RT was isolated by gel-shift. The recovered material was treated to regenerate the BbsI site, amplified by PCR, cleaved with BbsI and selected with HIV-RT again. This was repeated for 12 rounds. Material from round 12 bound approximately 10-fold more tightly than starting material. All selected round 12 primer-templates had similar sequence configuration with a 6–8 base G run at the 3′ primer terminus, similar to the HIV polypurine tract. Further modifications indicate that the Gs were necessary and sufficient for strong binding

Promozione del sistema dei poli di innovazione nello spazio web: analisi dei contenuti e delle reti di relazioni virtuali

Nel progetto di analisi e modellizzazione del sistema regionale dei poli di innovazione in Toscana (www.poliinnovazione.unimore.it), abbiamo esaminato in modo sistematico le informazioni disponibili nei siti web dei poli con due obiettivi: (i) analizzare la varietà di linguaggio e di contenuti che caratterizzano i poli nella loro attività on line; (ii) verificare in che misura i poli facciano riferimento agli stessi enti, imprese, organizzazioni, progetti e, tra questi, alle organizzazioni/o attività direttamente collegate al polo (come ad esempio i soggetti gestori dei poli laboratori, gli incubatori, gli aderenti). Questo articolo presenta nella prima parte l'analisi linguistica dei siti web prodotti dai poli di innovazione ed ha lo scopo di fornire un insieme di variabili per la valutazione delle loro strategie di promozione. Il metro di valutazione principale è l'individuazione della fonte dei materiali pubblicati online dai singoli poli (materiali originali vs. materiali prodotti da terzi), che è stato usato come indicatore del livello di partecipazione di ogni singolo polo nelle strategie di promozione delle proprie attività. Si è quindi cercato di quantificare il livello di coinvolgimento che ogni polo ha espresso – nel proprio sito web – attraverso la pubblicazione di testi. L'analisi è stata condotta utilizzando la metodologia di linguistica dei corpora al fine di svolgere un'indagine sia quantitativa sia qualitativa (simile alla metodologia nota come CADS), ed è stata effettuata prendendo in esame 24 termini relativi ai concetti di innovazione e sviluppo, all'interno dei contenuti web pubblicati dai poli di innovazione (azienda, aziende, centri, collaborazione, conoscenze, finanziamenti, gestione, gestore, impresa, imprese, industriale, innovazione, poli, polo, processi, progetti, progetto, ricerca, servizi, servizio, sviluppo, tecnologia, tecnologie, territorio). Attraverso la valutazione dell'utilizzo dei 24 termini all'interno dei testi web, l'analisi ha evidenziato come le nozioni di innovazione e sviluppo vengano costruite dai singoli poli in termini sia di significato, sia di connotazione. Oltre all'analisi linguistica, l'analisi dei testi web ha consentito anche di individuare in maniera puntuale i domini principali e i link completi citati nei siti web dei poli. Adottando una prospettiva di analisi delle reti di relazioni, con queste informazioni sulle reti virtuali abbiamo analizzato due questioni rilevanti per la modellizzazione del sistema dei poli di innovazione: attraverso le citazioni dei domini principali mettiamo in evidenza in che misura i siti web i poli hanno comunicato le connessioni tra di loro e con i soggetti attivi nel trasferimento tecnologico; attraverso l'analisi dei link completi presenti nei siti web dei singoli poli possiamo individuare in che misura i poli fanno riferimento allo stesso spazio di informazioni. La presentazione è strutturata come segue: nella sezione 1 vengono presentati i dati, gli strumenti e la metodologia utilizzata nell'analisi linguistica; nella sezione 2 viene presentata l'analisi linguistica dei 24 termini selezionati ; nella sezione 3 sono analizzate le reti di relazioni virtuali, la sezione 4 conclude. L'appendice 1 presenta i dettagli tecnici sulla raccolta e successiva pulizia dei dati; l'appendice 2 contiene la lista dei principali link completi presenti all'interno dei siti dei poli presi in esame

Fibrinogen-elongated Chain Inhibits Thrombin-induced Platelet Response, Hindering the Interaction with Different Receptors

The expression of the elongated fibrinogen γ chain, termed γ′, derives from alternative splicing of mRNA and causes an insertion sequence of 20 amino acids. This insertion domain interacts with the anion-binding exosite (ABE)-II of thrombin. This study investigated whether and how γ′ chain binding to ABE-II affects thrombin interaction with its platelet receptors, i.e. glycoprotein Ibα (GpIbα), protease-activated receptor (PAR) 1, and PAR4. Both synthetic γ′ peptide and fibrinogen fragment D*, containing the elongated γ′ chain, inhibited thrombin-induced platelet aggregation up to 70%, with IC50 values of 42 ± 3.5 and 0.47 ± 0.03 μm, respectively. Solid-phase binding and spectrofluorimetric assays showed that both fragment D* and the synthetic γ′ peptide specifically bind to thrombin ABE-II and competitively inhibit the thrombin binding to GpIbα with a mean Ki ≈ 0.5 and ≈35 μm, respectively. Both these γ′ chain-containing ligands allosterically inhibited thrombin cleavage of a synthetic PAR1 peptide, of native PAR1 molecules on intact platelets, and of the synthetic chromogenic peptide d-Phe-pipecolyl-Arg-p-nitroanilide. PAR4 cleavage was unaffected. In summary, fibrinogen γ′ chain binds with high affinity to thrombin and inhibits with combined mechanisms the platelet response to thrombin. Thus, its variations in vivo may affect the hemostatic balance in arterial circulation

AN INTERDISCIPLINARY APPROACH FOR THE SEISMIC VULNERABILITY ASSESSMENT OF HISTORICAL CENTRES IN MASONRY BUILDING AGGREGATES: APPLICATION TO THE CITY OF SCARPERIA, ITALY

Abstract. The seismic vulnerability of masonry building aggregates is very difficult to determine, since it is affected by many uncertainties. The most uncertain quantities concern the historical periodization of structural aggregates. Moreover, the studies made at the urban scale can hardly be thorough, and usually the knowledge achieved on the single units is not fully satisfactory, so that the structural designer has to deal with uncompleted architectonical surveys and partial data; one of the most important problems concerns the lack of knowledge about the boundary conditions between adjacent structures. In order to perform mechanical analyses, an extensive knowledge of materials and techniques adopted is required. In this paper, an integrated methodology for the seismic assessment of building aggregate is presented. It concerns a multidisciplinary knowledge-based approach calibrated over the historical centres and the urban aggregates; the procedure joins different aspects, such as the use of modern technologies for an integrated knowledge, plans reconstructions through archival documents, laser scanner digital survey of urban fronts, non-destructive investigations of the materials. GIS and BIM platforms have been used to implement and collect data in order to perform detailed analyses. The information allowed to assess the seismic vulnerability of the building aggregates and the expected damage scenarios through empirical methodologies. The city of Scarperia, founded a few kilometres from Florence during the Medieval Age and characterized by a medium seismicity, has been chosen as a case study for the presented procedure

Influence of carbon and nitrogen on electronic structure and hyperfine interactions in fcc iron-based alloys

Carbon and nitrogen austenites, modeled by Fe8N and Fe8C superstructures are studied by full-potential LAPW method. Structure parameters, electronic and magnetic properties as well as hyperfine interaction parameters are obtained. Calculations prove that Fe-C austenite can be successfully modeled by ordered Fe8C superstructure. The results show that chemical Fe-C bond in Fe8C has higher covalent part than in Fe8N. Detailed analysis of electric field gradient formation for both systems is performed. The calculation of electric field gradient allow us to carry out a good interpretation of Moessbauer spectra for Fe-C and Fe-N systems.Comment: 8 pages, 3 figures, IOP-style LaTeX, submitted to J. Phys. Condens. Matte

Multi-risk assessment in a historical city

AbstractNatural hazards pose a significant threat to historical cities which have an authentic and universal value for mankind. This study aims at codifying a multi-risk workflow for seismic and flood hazards, for site-scale applications in historical cities, which provides the Average Annual Loss for buildings within a coherent multi-exposure and multi-vulnerability framework. The proposed methodology includes a multi-risk correlation and joint probability analysis to identify the role of urban development in re-shaping risk components in historical contexts. The workflow is unified by exposure modelling which adopts the same assumptions and parameters. Seismic vulnerability is modelled through an empirical approach by assigning to each building a vulnerability value depending on the European Macroseismic Scale (EMS-98) and modifiers available in literature. Flood vulnerability is modelled by means of stage-damage curves developed for the study area and validated against ex-post damage claims. The method is applied to the city centre of Florence (Italy) listed as UNESCO World Heritage site since 1982. Direct multi-hazard, multi-vulnerability losses are modelled for four probabilistic scenarios. A multi-risk of 3.15 M€/year is estimated for the current situation. In case of adoption of local mitigation measures like floodproofing of basements and installation of steel tie rods, multi-risk reduces to 1.55 M€/yr. The analysis of multi-risk correlation and joint probability distribution shows that the historical evolution of the city centre, from the roman castrum followed by rebuilding in the Middle Ages, the late XIX century and the post WWII, has significantly affected multi-risk in the area. Three identified portions of the study area with a different multi-risk spatial probability distribution highlight that the urban development of the historical city influenced the flood hazard and the seismic vulnerability. The presented multi-risk workflow could be applied to other historical cities and further extended to other natural hazards

The effect of the sterile insect technique on vibrational communication: the case of Bagrada hilaris (Hemiptera: Pentatomidae)

The painted bug, Bagrada hilaris, is an agricultural pest in its original areas (Africa, South Asia, and the Middle East), and it has recently been recorded as an invasive species in southwestern part of the US, Chile, Mexico, and two islands in the Mediterranean basin. Its polyphagous diet causes severe damage to economically important crops. The control of this pest is primarily achieved by means of synthetic pesticides, which are often expensive, ineffective, and harmful to the ecosystem. Recent physiological bioassays to assess its potential control through the sterile insect technique demonstrated that mating between untreated females and males irradiated at doses of 64 and 100 Gy, respectively, resulted in 90% and 100% sterility of the eggs produced by the females. In this study, the mating abilities of virgin males irradiated at 60 and 100 Gy with virgin females were measured through a study of short-range courtship mediated by vibrational communication. The results indicate that males irradiated at 100 Gy emit signals with lower peak frequencies, mate significantly less than unirradiated males do, and do not surpass the early stages of courtship. Conversely, males irradiated at 60 Gy present vibrational signal frequencies that are comparable to those of the control and successfully mated males. Our findings suggest that B. hilaris individuals irradiated at 60 Gy are good candidates for the control of this species, given that they retain sexual competitiveness regardless of their sterility, through an area-wide program that incorporates the sterile insect technique

Effects of gamma irradiation on the fecundity, fertility, and longevity of the invasive stink bug pest Bagrada hilaris (Burmeister) (Hemiptera: Pentatomidae)

The bagrada bug, Bagrada hilaris, is an invasive insect pest in the family Brassicaceae that causes economically important damage to crops. It was originally present in Asia, the Middle East, and Africa, and was reported as invasive in the southwestern part of the US, in Chile, and on a few islands in the Mediterranean Basin. In its native range, B. hilaris is controlled by several egg parasitoid species that are under consideration as potential biological control agents. This research evaluated the impact of gamma irradiation on life history parameters, e.g., the fecundity, fertility, and longevity of B. hilaris, as a critical step towards assessing the feasibility of using the sterile insect technique against this recent invasive pest. Newly emerged adults of a laboratory colony originally collected from the island of Pantelleria (Italy) were gamma-irradiated. Life history parameters were evaluated at nine different doses, ranging from 16 Gy to 140 Gy. The minimal dose to approach full sterility was 100 Gy. Irradiation up to a maximum of 140 Gy apparently did not negatively impact the longevity of the adults. Even if both genders are sensitive to irradiation, the decline in fecundity for irradiated females could be exploited to release irradiated males safely to apply the SIT in combination with classical biological control. The data presented here allow us to consider, for the first time, the irradiation of bagrada adults as a suitable and feasible technique that could contribute to guaranteeing a safe approach to control this important pest species in agro-ecosystems. More research is warranted on the competitive fitness of irradiated males to better understand mating behavior as well as elucidate the possible mechanisms of sperm selection by polyandric B. hilaris female

NSHT: New Smart Hybrid Transducer for Structural and Geotechnical Applications

This work describes the application of a new transducer prototype for continuous monitoring in both the structural and geotechnical fields. The transducer is synthetically constituted by a wire of optical fiber embedded between two fiber tapes (fiberglass or carbon fiber) and glued by a matrix of polyester resin. The fiber optical wire ends have been connected to a control unit whose detection system is based on Brillouin optical time-domain frequency analysis. Three laboratory tests were carried out to evaluate the sensor's reliability and accuracy. In each experiment, the transducer was applied to a sample of inclinometer casing sets in different configurations and with different constraint conditions. The experimental collected data were compared with theoretical models and with data obtained from the use of different measuring instruments to perform validation and calibration of the transducer at the same time. Several diagrams can compare the transducer and highlight its suitability for the monitoring and maintenance of structures. The characteristic of the transducer suggests its use as a mixed system for reinforcing and monitoring, especially in the lifetime maintenance of critical infrastructures such as transportation and service networks, and historical heritag

Liquid baits with Oenococcus oeni increase captures of Drosophila suzukii

The spotted-wing drosophila (SWD), Drosophila suzukii Matsumura (Diptera: Drosophilidae), native to Eastern Asia, is an invasive alien species in Europe and the Americas, where it is a severe pest of horticultural crops, including soft fruits and wine grapes. The conventional approach to controlling infestations of SWD involves the use of insecticides, but the frequency of application for population management is undesirable. Consequently, alternative strategies are urgently needed. Effective and improved trapping is important as an early risk detection tool. This study aimed to improve Droskidrink® (DD), a commercially available attractant for SWD. We focused on the chemical and behavioral effects of adding the bacterium Oenococcus oeni (Garvie) to DD and used a new trap design to enhance the effects of attractive lures. We demonstrate that microbial volatile compounds produced by O. oeni are responsible for the increase in the attractiveness of the bait and could be later utilized for the development of a better trapping system. Our results showed that the attractiveness of DD was increased up to two-fold by the addition of commercially available O. oeni when combined with an innovative trap design. The new trap-bait combination increased the number of male and especially female catches at low population densitie