The NorduGrid architecture and tools

The NorduGrid project designed a Grid architecture with the primary goal to meet the requirements of production tasks of the LHC experiments. While it is meant to be a rather generic Grid system, it puts emphasis on batch processing suitable for problems encountered in High Energy Physics. The NorduGrid architecture implementation uses the \globus{} as the foundation for various components, developed by the project. While introducing new services, the NorduGrid does not modify the Globus tools, such that the two can eventually co-exist. The NorduGrid topology is decentralized, avoiding a single point of failure. The NorduGrid architecture is thus a light-weight, non-invasive and dynamic one, while robust and scalable, capable of meeting most challenging tasks of High Energy Physics.Comment: Talk from the 2003 Computing in High Energy Physics and Nuclear Physics (CHEP03), La Jolla, Ca, USA, March 2003, 9 pages,LaTeX, 4 figures. PSN MOAT00

Functional connectivity changes in the delta frequency band following trauma treatment in complex trauma and dissociative disorder patients

Objective: Phase-oriented trauma treatment is efficacious in the treatment of complex trauma and dissociative disorder patients. However, the neural correlates of this therapeutic effect are not yet well-understood. In the current study we investigated whether patients show a strengthening in functional network connectivity in the delta frequency band (1–3.5 Hz) over the course of phase-oriented inpatient trauma treatment while they performed an emotion regulation task. Further, we examined whether neural changes were associated with symptom reduction and improvement in emotion regulation skills. Methods: Before and after 8 weeks of treatment, electroencephalography (EEG) was acquired in patients (n = 28) with a complex posttraumatic stress disorder (cPTSD) or complex dissociative disorder (CDD). They also completed clinical and emotion regulation questionnaires. To delimit data variability, patients participated as one dissociative part that is referred to as Apparently Normal Part (ANP). Patients' data were compared to a matched healthy control croup (n = 38), also measured twice. Results: Prior to treatment, functional connectivity was significantly lower in patients compared to controls during cognitive reappraisal of unpleasant pictures and passive viewing of unpleasant and neutral pictures. These hypoconnected networks largely overlapped with networks typically activated during the recall of (emotional) autobiographical memories. Functional connectivity strength within these networks significantly increased following treatment and was comparable to controls. Patients showed symptom reduction across various clinical domains and improvement in the use of cognitive reappraisal as emotion regulation strategy. Treatment-related network normalizations were not related to changes in questionnaire data. Conclusion: Phase-oriented treatment may strengthen connections between regions that are activated during autobiographical recall. These findings encourage further investigation of this circuitry as a therapeutic target in cPTSD and CDD patients

Resting-state functional connectivity in patients with a complex PTSD or complex dissociative disorder before and after inpatient trauma treatment

INTRODUCTION: Recent research suggests that traumatized patients are characterized by disrupted resting-state functional connectivity. We examined whether neural networks involved in resting-state change over the course of a phase-oriented inpatient treatment for complex traumatized and dissociative disorder patients. We also investigated associations between these network alterations and clinical symptoms and emotion regulation skills. METHODS: Pre- and post-treatment, electroencephalography (EEG) was recorded during resting-state in patients (n = 23) with a complex dissociative disorder (CDD) or complex posttraumatic stress disorder (cPTSD). Patients also completed clinical and emotion regulation questionnaires. To reduce variance in the collected data, patients were exclusively tested as one prototypical dissociative part referred to as Apparently Normal Part (ANP). Functional network connectivity was examined and compared with a matched healthy control group (n = 37), also measured twice. RESULTS: Prior to treatment and compared with controls, patients had a significantly lower functional connectivity strength within eyes-open and eyes-closed resting-state networks in the theta and alpha frequency band. Following treatment, functional connectivity strength within these networks was comparable to the control group and comprised areas belonging to the default mode network (DMN) and prefrontal as well as anterior cingulate control regions. Treatment-related network normalizations in the theta frequency band were associated with a self-reported increase in the use of cognitive reappraisal strategies and reduction in emotion regulation difficulties. CONCLUSION: Phase-oriented trauma treatment can strengthen resting-state network connectivity and can increase the capacity of complex traumatized and dissociative patients as ANP to handle emotional challenges effectively

Atlas Data-Challenge 1 on NorduGrid

The first LHC application ever to be executed in a computational Grid environment is the so-called ATLAS Data-Challenge 1, more specifically, the part assigned to the Scandinavian members of the ATLAS Collaboration. Taking advantage of the NorduGrid testbed and tools, physicists from Denmark, Norway and Sweden were able to participate in the overall exercise starting in July 2002 and continuing through the rest of 2002 and the first part of 2003 using solely the NorduGrid environment. This allowed to distribute input data over a wide area, and rely on the NorduGrid resource discovery mechanism to find an optimal cluster for job submission. During the whole Data-Challenge 1, more than 2 TB of input data was processed and more than 2.5 TB of output data was produced by more than 4750 Grid jobs.Comment: Talk from the 2003 Computing in High Energy Physics and Nuclear Physics (CHEP03), La Jolla, Ca, USA, March 2003, 7 pages, 3 ps figure

Eletrorresistividade aplicada na região do litoral norte do Estado de São Paulo

A geophysical survey using geoelectrical method was carried out on several coastal plains along the north coast of the State of São Paulo . These plains, corresponding to Baleia, Juréia, Juqueí, Una, Guaratuba, Boracéia, Maresias and Saí beaches, are small, urban tourist, areas under intense development. Water supply from the municipality is often not provided before most of the lots are occupied. Groundwater becomes the main source of water in most cases. Geologicaly the area is formed of Quaternary sediments covering the crystalline basement. These sediments, mostly sandy, contain silt and clay layers, which are sometimes saturated with salt water. The sediments present variable values of resistivities, depending of the surrounding topography. Large plains frequently contain salt water intrusions. Small plains, surrounded by high elevations, usually contain fresh water, even at greater depths, imposing high resistivities to the sediments. Telluric currents with high intensity were present at all investigated points, limiting MN spacing to a maximum of 4 meters. Due to the elevated soil humidity, contact resistance was low, allowing currents of 500 mA to flow in the ground using source voltages of about 500 V.Um levantamento geofísico, utilizando métodos elétricos, foi executado em várias planícies costeiras do litoral norte do Estado de São Paulo. Estas planícies correspondem às praias da Baleia, Juréia, Juqueí, Una, Boracéia, Maresias e Saí, que são áreas urbanas turísticas que se encontram sob forte desenvolvimento. O suprimento de água potável pela municipalidade é uma realidade somente quando a maioria dos lotes dos terrenos estão ocupados. Desta forma a água subterrânea se transforma na principal fonte para o abastecimento quando estas áreas se encontram em suas fases preliminares de ocupação. Geologicamente a região é constituída por sedimentos Quaternários cobrindo o embasamento cristalino. Estes sedimentos são na maior parte arenosos, contendo camadas de silte e argila, as quais são algumas vezes saturadas por água salgada. Os sedimentos presentes apresentam variados valores de resistividade, muitas vezes influenciados pela topografia circundante. Amplas planícies contém freqüentemente intrusões de água salgada. Pequenas planícies, circundadas por grandes elevações topográficas, usualmente contém água doce, mesmo a maiores profundidades. Correntes telúricas de elevada intensidade estavam presentes em praticamente todos os pontos investigados, atingindo duas dezenas de milivolts, para afastamentos de 10 metros entre os eletrodos de potencial, variando em tempos de poucos segundos, limitando o espaçamento MN entre os eletrodos de potencial, a um máximo de 4 metros. Devido à elevada umidade, a resistência de contato era geralmente baixa, permitindo que correntes de até 500 mA circulassem a partir da fonte com tensão de até 500 V

The propensity of molecules to spatially align in intense light fields

The propensity of molecules to spatially align along the polarization vector of intense, pulsed light fields is related to readily-accessible parameters (molecular polarizabilities, moment of inertia, peak intensity of the light and its pulse duration). Predictions can now be made of which molecules can be spatially aligned, and under what circumstances, upon irradiation by intense light. Accounting for both enhanced ionization and hyperpolarizability, it is shown that {\it all} molecules can be aligned, even those with the smallest static polarizability, when subjected to the shortest available laser pulses (of sufficient intensity).Comment: 8 pages, 4 figures, to be submitted to PR

Classification of phase transitions in small systems

We present a classification scheme for phase transitions in finite systems like atomic and molecular clusters based on the Lee-Yang zeros in the complex temperature plane. In the limit of infinite particle numbers the scheme reduces to the Ehrenfest definition of phase transitions and gives the right critical indices. We apply this classification scheme to Bose-Einstein condensates in a harmonic trap as an example of a higher order phase transitions in a finite system and to small Ar clusters.Comment: 12 pages, 4 figures, accepted for publication in Phys. Rev. Let

Ionic structure and photoabsorption in medium sized sodium clusters

We present ground-state configurations and photoabsorption spectra of Na-7+, Na-27+ and Na-41+. Both the ionic structure and the photoabsorption spectra of medium-size sodium clusters beyond Na-20 have been calculated self-consistently with a nonspherical treatment of the valence electrons in density functional theory. We use a local pseudopotential that has been adjusted to experimental bulk properties and the atomic 3s level of sodium. Our studies have shown that both the ionic structure of the ground state and the positions of the plasmon resonances depend sensitively on the pseudopotential used in the calculation, which stresses the importance of its consistent use in both steps.Comment: 4 pages, 3 figures. Accepted for publication in PRB, tentatively July 15th, 1998 some typos corrected, brought to nicer forma