Drazepinone, a trisubstituted tetrahydronaphthofuroazepinone with herbicidal activity produced by Drechslera siccans

When grown in a minimal-defined medium, a strain of Drechslera siccans, a pathogenic fungus isolated from seeds of Lolium perenne, produced phytotoxic metabolites. This strain is one of the best toxin producers among several grass pathogenic fungal strains collected and tested to find phytotoxins to be used as natural herbicides of monocot weeds. From the culture filtrates of D. siccans, we isolated a new phytotoxic trisubstituted naphthofuroazepinone, named drazepinone, and characterised it as a 3,5,12a-trimethyl-2,5,5a,12a-tetrahydro- 1H-naphtho[2′,3′:4,5]furo[2,3-b]azepin-2-one. Assayed at 2 μg μl-1 solution the novel metabolite proved to have broad-spectrum herbicidal properties, without antibacterial and antifungal activities, and low zootoxic activity. Its original chemical structure and the interesting biological properties make drazepinone a potential natural herbicide. © 2005 Elsevier Ltd. All rights reserved

The momentum and photon energy dependence of the circular dichroic photoemission in the bulk Rashba semiconductors BiTeX (X = I, Br, Cl)

Bulk Rashba systems BiTeX (X = I, Br, Cl) are emerging as important candidates for developing spintronics devices, because of the coexistence of spin-split bulk and surface states, along with the ambipolar character of the surface charge carriers. The need of studying the spin texture of strongly spin-orbit coupled materials has recently promoted circular dichroic Angular Resolved Photoelectron Spectroscopy (cd-ARPES) as an indirect tool to measure the spin and the angular degrees of freedom. Here we report a detailed photon energy dependent study of the cd-ARPES spectra in BiTeX (X = I, Br and Cl). Our work reveals a large variation of the magnitude and sign of the dichroism. Interestingly, we find that the dichroic signal modulates differently for the three compounds and for the different spin-split states. These findings show a momentum and photon energy dependence for the cd-ARPES signals in the bulk Rashba semiconductor BiTeX (X = I, Br, Cl). Finally, the outcome of our experiment indicates the important relation between the modulation of the dichroism and the phase differences between the wave-functions involved in the photoemission process. This phase difference can be due to initial or final state effects. In the former case the phase difference results in possible interference effects among the photo-electrons emitted from different atomic layers and characterized by entangled spin-orbital polarized bands. In the latter case the phase difference results from the relative phases of the expansion of the final state in different outgoing partial waves.Comment: 6 pages, 4 figure

THE 9TH JULY 1998 FAIAL EARTHQUAKE: COMPARISON OF STOCHASTIC FINITE FAULT DAMAGE SIMULATION WITH SURVEYED DATA

The Azores earthquake, July 9, 1998 (Mw 6.2) caused a large damage to the stock of old masonry buildings, with maximum felt intensity Is=VIII (MMI). A stochastic strong ground motion (SM) was simulated on the islands struck by the earthquake using published fault solution, to derive maps of average Peak Ground Acceleration (PGA) at bedrock. Detailed analysis was done at the Horta station comparing stochastic-computed and observed PGA, PGV, Response Acceleration Spectra and Response Spectrum Intensity (SI) values. Although recordings on Faial (Horta) and Terceira Islands are not enough to fully constrain the simulation parameters, they can define the range of possible variation. Relationships between PGA and MMI were used to retrieve intensity. Retrieved and observed intensities allowed to derive an average damage index according to the EMS-98 classification

Assessing seismic damage through stochastic simulation of ground shaking: the case of the 1998 Faial Earthquake (Azores Islands)

In July 1998, an Mw = 6.2 earthquake struck the islands of Faial, Pico and San Jorge (in the Azores Archipelago), registering VIII on the Modified Mercalli Intensity scale and causing major destruction in the northeastern part of Faial. The main shock was located offshore, 8 km North East of the island, and it triggered a seismic sequence that lasted for several weeks. The existing data for this earthquake include both the general tectonic environment of the region and the teleseismic information. This is accompanied by one strong-motion record obtained 15 km from the epicentre, the epicentre location of aftershocks, and a large collection of the damage inflicted to the building stock (as poor rubble masonry, of 2-3 storeys). The present study was carried out in two steps: first, with a finite-fault stochastic simulation method of ground motion at sites throughout the affected islands, for two possible locations of the rupturing fault and for a large number of combinations of rupture mechanisms (as a parametric analysis); secondly, the damage to buildings was modelled using a well-known macroseismic method that considers the building typologies and their associated vulnerabilities. The main intent was to integrate different data (geological, seismological and building features) to produce a scenario model to reproduce and justify the level of damage generated during the Faial earthquake. Finally, through validation of the results provided by these different approaches, we obtained a complete procedure for the parameters of a first model for the production of seismic damage scenarios for the Azores Islands region

Emergence of pseudogap from short-range spin-correlations in electron doped cuprates

Electron interactions are pivotal for defining the electronic structure of quantum materials. In particular, the strong electron Coulomb repulsion is considered the keystone for describing the emergence of exotic and/or ordered phases of quantum matter as disparate as high-temperature superconductivity and charge- or magnetic-order. However, a comprehensive understanding of fundamental electronic properties of quantum materials is often complicated by the appearance of an enigmatic partial suppression of low-energy electronic states, known as the pseudogap. Here we take advantage of ultrafast angle-resolved photoemission spectroscopy to unveil the temperature evolution of the low-energy density of states in the electron-doped cuprate Nd$_{\text{2-x}}$Ce$_{\text{x}}$CuO$_{\text{4}}$, an emblematic system where the pseudogap intertwines with magnetic degrees of freedom. By photoexciting the electronic system across the pseudogap onset temperature T*, we report the direct relation between the momentum-resolved pseudogap spectral features and the spin-correlation length with an unprecedented sensitivity. This transient approach, corroborated by mean field model calculations, allows us to establish the pseudogap in electron-doped cuprates as a precursor to the incipient antiferromagnetic order even when long-range antiferromagnetic correlations are not established, as in the case of optimal doping.Comment: 17 pages, 3 figure

“Urban Disaster Prevention Strategies Using MAcroseismic Fields and FAult Sources”

In the framework of EU research project “Urban Disaster Prevention Strategies Using MAcroseismic Fields and FAult Sources” (Grant Agreement n. 230301/2011/613486/SUB/A5) innovative approaches are proposed to improve critical points in the procedures for assessing probabilistic hazard and seismic risk; they are tested in particular locations – Mt. Etna, Vesuvius and Campi Flegrei areas (Italy), Azores Islands and areas hit by offshore activity (Portugal), Alicante-Murcia area (Spain) and South Iceland including Reykjavik surrounding urban area (Iceland). A unique probabilistic procedure has been used for seismic hazard evaluation processing both macroseismic fields and characteristics of fault sources. The direct application of probabilistic methodologies to observed and/or synthetic macroseismic fields allows us to carry out a more complete treatment of the uncertainties in the case of both point-wise and linear properties of a fault. An improvement of the urban scale vulnerability information on building and network systems (typologies, schools, strategic buildings, lifelines, and so on) has been introduced to use the new concept of global Disruption Index, with the objective to provide a systematic way to measure the earthquake impact in urbanized areas considered as a complex network. These measures have been then used to identify which nodes are likely to introduce major disruption in the whole urban system, and also which one of them suggests greater risk reduction if intervention takes place. Besides the disaster prevention strategies based on the level of risk, another effective component of disaster-risk reduction is given by long-term activities using educational information systems. To reduce the absence of risk perception in the community some actions have been performed, such as the development of educational materials and the design of a mobile earthquake interactive experience with interactive panels for children and adults, and a central platform for the simulation of an earthquake

Collapse of superconductivity in cuprates via ultrafast quenching of phase coherence

The possibility of driving phase transitions in low-density condensates through the loss of phase coherence alone has far-reaching implications for the study of quantum phases of matter. This has inspired the development of tools to control and explore the collective properties of condensate phases via phase fluctuations. Electrically-gated oxide interfaces, ultracold Fermi atoms, and cuprate superconductors, which are characterized by an intrinsically small phase-stiffness, are paradigmatic examples where these tools are having a dramatic impact. Here we use light pulses shorter than the internal thermalization time to drive and probe the phase fragility of the Bi$_2$Sr$_2$CaCu$_2$O$_{8+\delta}$ cuprate superconductor, completely melting the superconducting condensate without affecting the pairing strength. The resulting ultrafast dynamics of phase fluctuations and charge excitations are captured and disentangled by time-resolved photoemission spectroscopy. This work demonstrates the dominant role of phase coherence in the superconductor-to-normal state phase transition and offers a benchmark for non-equilibrium spectroscopic investigations of the cuprate phase diagram.Comment: 24 pages, 9 figures, Main Text and Supplementary Informatio

An interactive travelling educational path on earthquakes and volcanoes

A mobile earthquake interactive path is an action of disaster-risk reduction given by long-term activities based on an educational information system. The idea is to provide a realistic space and to design in it an interactive path, aimed at both children and adults, explaining. issues related to seismic hazard especially in urban sectors close to volcanic areas, such as Mt. Etna, Vesuvius and Campi Flegrei (Italy) and Azores Islands (Portugal). The educational path would ideally include a wall with basic information on natural hazards related to seismic and volcanic events, with hands on and interactive exhibits, a special "edutainment" corner focused on children, and a central platform for people who will experience the simulation of an earthquake, while being instructed on how to respond to the event. This educational information system represents a way of putting the results of the project UPStrat-MAFA (Urban disaster Prevention Strategies using MAcroseismic Fields and FAult Sources ) to the service of the entire community in order to strengthen people's awareness and preparedness related to seismic and volcanic hazards. The fundamental aspect of the risk level for people living near a volcano is also included in the educational experience

Quantitative seismic risk evaluation and mapping: cases of schools and residential facilities in Lisbon and Algarve

This contribution deals with activities within the framework of an EC-project, entitled "UPStrat-MAFA (Urban prevention strategies using macroseismic and fault sources)", emphasising the inventory, vulnerability and seismic risk of buildings. The cases considered deal with elementary and non-elementary public schools as well as the residential building stock in Lisbon and Algarve in mainland Portugal. A new concept of global disruption measures is introduced and discussed, with the objective of providing a systematic way to quantify earthquake impact in urban areas. This approach provides civil protection, the authorities and local decision makers with a new tool judged to be valuable in prioritizing mitigation measures and responses.Co-financed by the EU - Civil Protection Financial Instrument, in the framework the European project ”Urban disaster Prevention Strategies using MAcroseismic Fields and FAult Sources (Acronym: UPStrat-MAFA, Grant Agreement N. 23031/2011/613486/SUB/A5). http://ec.europa.eu/echo/funding/cp_projects2011_en.htmPublishedLisbon - Portugal4.1. Metodologie sismologiche per l'ingegneria sismicaope