Quantum chaotic resonances from short periodic orbits

We present an approach to calculating the quantum resonances and resonance wave functions of chaotic scattering systems, based on the construction of states localized on classical periodic orbits and adapted to the dynamics. Typically only a few of such states are necessary for constructing a resonance. Using only short orbits (with periods up to the Ehrenfest time), we obtain approximations to the longest living states, avoiding computation of the background of short living states. This makes our approach considerably more efficient than previous ones. The number of long lived states produced within our formulation is in agreement with the fractal Weyl law conjectured recently in this setting. We confirm the accuracy of the approximations using the open quantum baker map as an example.Comment: 4 pages, 4 figure

Oral tradition as a worldwide phenomenon

It is my view that oral tradition is the source of all of the world's literary traditions. Two principal concerns have driven my work (1995, 2000, 2002): the collection of examples of living oral literature (ballads, songs, proverbs, legends, stories, oral history, and epics) in different countries and traditions (Spain, Hispanoamerica, central Africa), and the comparative study of world literary traditions from Homer to Garcia Marquez.Not

Metallicity dependence of HMXB populations

High-mass X-ray binaries (HMXBs) might have contributed a non-negligible fraction of the energy feedback to the interstellar and intergalactic media at high redshift, becoming important sources for the heating and ionization history of the Universe. However, the importance of this contribution depends on the hypothesized increase in the number of HMXBs formed in low-metallicity galaxies and in their luminosities. In this work we test the aforementioned hypothesis, and quantify the metallicity dependence of HMXB population properties. We compile from the literature a large set of data on the sizes and X-ray luminosities of HMXB populations in nearby galaxies with known metallicities and star formation rates. We use Bayesian inference to fit simple Monte Carlo models that describe the metallicity dependence of the size and luminosity of the HMXB populations. We find that HMXBs are typically ten times more numerous per unit star formation rate in low-metallicity galaxies (12 + log(O/H) < 8, namely < 20% solar) than in solar-metallicity galaxies. The metallicity dependence of the luminosity of HMXBs is small compared to that of the population size. Our results support the hypothesis that HMXBs are more numerous in low-metallicity galaxies, implying the need to investigate the feedback in the form of X-rays and energetic mass outflows of these high-energy sources during cosmic dawn.Comment: 9 pages, 5 figures, accepted for publication in Astronomy & Astrophysic

The 1755 earthquake in the Algarve (South of Portugal): what would happen nowadays?

The 1755 Lisbon earthquake, which reached a magnitude of 8.5, remains the most powerful and destructive to hit Europe so far. Within minutes, many lives were lost, populations displaced, livelihoods, homes and infrastructures were destroyed. Although frequently associated to the city of Lisbon, one of the most important European cities at the time, this earthquake caused similar damage and casualties, if not greater, in the southwest of the Algarve, where the seismic intensity was estimated at IX-X Mercalli Intensity Scale. Some time later a tsunami increased the number of victims and the amount of damage. In some locations the tsunami caused greater destruction than the earthquake itself. The tsunami hit both coasts of the North Atlantic; however, the more destructive damage occurred in the Portuguese coast, south from Lisbon, in the Gulf of Cadiz and in the Moroccan coast. The downtown of Lisbon was flooded by waves that reached a height of 6 m. The water flooded an area with an extension of around 250 m from the coast. In the Southwest part of Algarve the waves reached a height between 10 and 15 m and the flooded area was much larger. Through the analysis of recent research works on the assessment of the 1755 tsunami parameters and the interpretation of the more reliable historical documents, it is our intention to analyse the destructive power of the tsunami in the Algarve and delimit the flooded area. Using simple techniques of simulation it is our intention to assess the impacts nowadays of the occurrence of a tsunami similar to the one that hit the Algarve in 1755, which would probably affect a greater number of people, buildings and infrastructures. This assessment is an important instrument not only in terms of disaster preparedness but also for the integration of risk mitigation measures in land use planning

Computer assisted audit tools and techniques in real world: CAATT's applications and approaches in context

Nowadays, Computer Aided Audit Tools (and Techniques’) support almost all audit processes concerning data extraction and analysis. These tools were firstly aimed to support financial auditing processes. However, their scope is beyond this, therefore, we present case studies and good practices in an academic context. Although in large auditing companies Audit Tools to do data extraction and analysis are very common and applied in several contexts, we realized that is not easy to find practical examples to teach this subject. Computer Science students’ and teachers usually use application manuals’, which are adequate to explore the tools itself, but they are not enough to do real data analysis: a “hands-on” approach is essential. Despite that, our students didn’t belong to any Computer Science graduation. CAATTs are good examples of software aimed to help auditors to analyze data, to explore and study distinct data sets in auditing processes. CAATTs represent an innovative approach to do data analysis, mainly because they allow the manipulation of very large data records with no significant added costs. Frequently, users have another difficulty: they are not able to adequate their data sets or to prepare their data in order to create useful input data, to do their analysis. In this paper, we present a proposal of extraction and data analysis, based on data sets obtained from a LMS platform (Learning Management System), a real data set that can be used to support students learning about CAATTs topic. Fundamental procedures to reach specific answers using a CAATT as a main tool to do data extraction and analysis are also referred. The context for this case study was an Information Technologies applied to Auditing course in a Master Degree graduation

Runoff at the micro-plot and slope scale following wildfire, central Portugal

Through their effects on soil properties and vegetation/litter cover, wildfires can strongly enhance overland flow generation and accelerate soil erosion [1] and, thereby, negatively affect land-use sustainability as well as downstream aquatic and flood zones. Wildfires are a common phenomenon in present-day Portugal, devastating in an average year some 100.000 ha of forest and woodlands and in an exceptional year like 2003 over 400.000 ha. There therefore exists a clear need in Portugal for a tool that can provide guidance to post-fire land management by predicting soil erosion risk, on the one hand, and, on the other, the mitigation effectiveness of soil conservation measures. Such a tool has recently been developed for the Western U.S.A. [3: ERMiT] but its suitability for Portuguese forests will need to be corroborated by field observations. Testing the suitability of existing erosion models in recently burned forest areas in Portugal is, in a nutshell, the aim of the EROSFIRE projects. In the first EROSFIRE project the emphasis was on the prediction of erosion at the scale of individual hill slopes. In the ongoing EROSFIRE-II project the spatial scope is extended to include the catchment scale, so that also the connectivity between hill slopes as well as channel and road processes are being addressed. Besides ERMiT, the principal models under evaluation for slope-scale erosion prediction are: (i) the variant of USLE [4] applied by the Portuguese Water Institute after the wildfires of 2003; (ii) the Morgan–Morgan–Finney model (MMF) [5]; (iii) MEFIDIS [6]. From these models, MEFIDIS and perhaps MMF will, after successful calibration at the slope scale, also be applied for predicting catchment-scale sediment yields of extreme events

Lamotrigine treatment of aggression in female borderline patients, Part II: an 18-month follow-up

Borderline patients often display pathological aggression. We previously tested lamotrigine, an anti-convulsant, in therapy for aggression in women with borderline personality disorder (BPD) (J Psychopharmacol 2005; 19: 287–291), and found significant changes on most scales of the State-Trait Anger Expression Inventory (STAXI) after eight weeks. To assess the longerterm efficacy of lamotrigine in therapy for aggression in women with BPD, this 18-month follow-up observation was carried out, in which patients (treated with lamotrigine: n = 18; former placebo group: n = 9) were tested every six months. According to the intent-to-treat principle, significant changes on all scales of the STAXI were observed in the lamotrigine-treated subjects. All subjects tolerated lamotrigine relatively well. Lamotrigine appears to be an effective and relatively safe agent in the longer-term treatment of aggression in women with BPD