667 research outputs found

    Coordinate representation of particle dynamics in AdS and in generic static spacetimes

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    We discuss the quantum dynamics of a particle in static curved spacetimes in a coordinate representation. The scheme is based on the analysis of the squared energy operator E^2, which is quadratic in momenta and contains a scalar curvature term. Our main emphasis is on AdS spaces, where this term is fixed by the isometry group. As a byproduct the isometry generators are constructed and the energy spectrum is reproduced. In the massless case the conformal symmetry is realized as well. We show the equivalence between this quantization and the covariant quantization, based on the Klein-Gordon type equation in AdS. We further demonstrate that the two quantization methods in an arbitrary (N+1)-dimensional static spacetime are equivalent to each other if the scalar curvature terms both in the operator E^2 and in the Klein-Gordon type equation have the same coefficient equal to (N-1)/(4N).Comment: 14 pages, no figures, typos correcte

    Bridging the ICD11 and the DSM-5 personality disorders classification systems: The role of the PID5BF + M

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    Introduction: In both the ICD-11 Classification of Personality Disorders and the DSM-5 Alternative Model of Personality Disorders (AMPD) personality disorders (PD) are characterized by impairments in self- and interpersonal functioning which distinguish the various levels of dysfunction. Moreover, pathological traits are used by these classification systems to define the stylistic expression of personality dysfunction. Negative affectivity, detachment, antagonism/dissociality, and disinhibition feature as trait domains in each of these models. However, there are also differences between the two models, namely, in the psychoticism domain, which does not feature as a personality trait domain in the ICD-11, and in the anankastia domain, corresponding to compulsivity in the DSM-5, which was removed from the final AMPD model. Furthermore, facets are acknowledged by the DSM-5 within each trait domain, while this does not occur in the ICD-11. In view of the similarity between these classification systems, their harmonization would be beneficial for the clinical profession. With this goal in mind, the PID5BF + M, an algorithm that assesses the DSM-5 and ICD-11 six trait domains and 18 facets, was developed and has proven to adequately characterize the ICD-11 trait domains by means of DSM-5 trait facets. Methods: The current study compares a community sample (N = 280, Mage = 48.01, 53.2% females) with a PD sample (N = 131, Mage = 42.66, 45.0% females) along with the PID5BF + M, the LPFS-SR and the PID-5. Given that the PID5BF + M total can be seen as a measure of the level of personality dysfunction, strong relations between the PID5BF + M total and the LPFS-SR total are expected. Strong relations between the trait specifiers measured by the PID5BF + M and the PID-5 are also expected. Finally, the community and clinical samples are expected to differentiate by means of the dimensions assessed through the three afore-mentioned measures. The Spearman rank-order correlation coefficient was used to measure the strength and direction of associations between the PID5BF + M total and the LPFS-SR total and between the PID5BF + M and the PID-5 traits. Group differences were explored using the Mann–Whitney U test for independent samples. Results: As expected, there were strong, significant, and positive relations between the measures. Furthermore, higher scores were observed in all the variables for the PD group against the community group. Discussion: Although this study has limitations, its findings sustain that the PID5BF + M has potential to assess the severity of personality disfunction and to characterize the stylistic features of PD as they are conceived by both the ICD-11 and the DSM-5. Although more research is needed regarding the convergent validity of the PID5BF + M, this new test contributes to the harmonization of both systems and to parsimony in the assessment of PD, which is the main objective of clinical practice.info:eu-repo/semantics/publishedVersio

    Pemetrexed na segunda linha de tratamento do carcinoma do pulmão de não pequenas células – A experiência portuguesa

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    AbstractUntil 2004, docetaxel in monotherapy was the standard for second-line treatment of non-small cell lung cancer (NSCLC). Pemetrexed (P) has shown similar activity in this setting with a better adverse event profile. In Portugal, it was introduced in October of 2004.We have carried out a retrospective analysis of patients (pts) who received P for second-line NSCLC in Portugal from October 2004 to December 2006. Data were collected from the records of pts with locally advanced or metastatic NSCLC and failed first-line chemotherapy enrolled in centers participating in the Portuguese Lung Cancer Study Group (GECP). Objective response (OR; complete [CR] or partial [PR] response) was evaluated using RECIST and safety was assessed using serious or non-serious adverse events (SAEs/AEs).By December 2006, 19 GECP centers had enrolled 244 pts who had received P for ≥1cycle, and were considered evaluable for both objective response and safety. Demography: male/female, 175/69; median age, 57.0years (range 20-81); smoking status, y/ex/n, 116/57/71; adenocarcinoma / squamous-cell carcinoma/other histology, 141/72/31; mean time to progression (TTP) 8.07months. Disease control in 209 evaluable pts was observed in 116 (55.5%): 2 CR, 45 PR and 69 SD; mean TTP 4.70months. The majority of AEs were grade 3 anemia (15 pts) and neutropenia (18 pts). The mean overall survival was 17.27months.Our retrospective analysis has observed a similar disease control rate with P in 2nd line (55.5%), and TTP (4.7months) in our current unselected population to that published in the literature. P is an option for second-line NSCLC with a good tolerability.Rev Port Pneumol 2008; XIV (Sup.2): S9-S2

    Non-perturbative electron dynamics in crossed fields

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    Intense AC electric fields on semiconductor structures have been studied in photon-assisted tunneling experiments with magnetic field applied either parallel (B_par) or perpendicular (B_per) to the interfaces. We examine here the electron dynamics in a double quantum well when intense AC electric fields F, and tilted magnetic fields are applied simultaneously. The problem is treated non-perturbatively by a time-dependent Hamiltonian in the effective mass approximation, and using a Floquet-Fourier formalism. For B_par=0, the quasi-energy spectra show two types of crossings: those related to different Landau levels, and those associated to dynamic localization (DL), where the electron is confined to one of the wells, despite the non-negligible tunneling between wells. B_par couples parallel and in-plane motions producing anti-crossings in the spectrum. However, since our approach is non-perturbative, we are able to explore the entire frequency range. For high frequencies, we reproduce the well known results of perfect DL given by zeroes of a Bessel function. We find also that the system exhibits DL at the same values of the field F, even as B_par non-zero, suggesting a hidden dynamical symmetry in the system which we identify with different parity operations. The return times for the electron at various values of field exhibit interesting and complex behavior which is also studied in detail. We find that smaller frequencies shifts the DL points to lower field F, and more importantly, yields poorer localization by the field. We analyze the explicit time evolution of the system, monitoring the elapsed time to return to a given well for each Landau level, and find non-monotonic behavior for decreasing frequencies.Comment: REVTEX4 + 11 eps figs, submitted to Phys. Rev.

    Reciprocal effects among changes in weight, body image, and other psychological factors during behavioral obesity treatment: a mediation analysis

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    <p>Abstract</p> <p>Background</p> <p>Changes in body image and subjective well-being variables (e.g. self-esteem) are often reported as outcomes of obesity treatment. However, they may, in turn, also influence behavioral adherence and success in weight loss. The present study examined associations among obesity treatment-related variables, i.e., change in weight, quality of life, body image, and subjective well-being, exploring their role as both mediators and outcomes, during a behavioral obesity treatment.</p> <p>Methods</p> <p>Participants (BMI = 31.1 ± 4.1 kg/m<sup>2</sup>; age = 38.4 ± 6.7 y) were 144 women who attended a 12-month obesity treatment program and a comparison group (n = 49), who received a general health education program. The intervention included regular group meetings promoting lasting behavior changes in physical activity and dietary intake. Body image, quality of life, subjective well-being, and body weight were measured at baseline and treatment's end. Mediation was tested by multiple regression and a resampling approach to measure indirect effects. Treatment group assignment was the independent variable while changes in weight and in psychosocial variables were analyzed alternatively as mediators and as dependent variables.</p> <p>Results</p> <p>At 12 months, the intervention group had greater weight loss (-5.6 ± 6.8% vs. -1.2 ± 4.6%, p < .001) and larger decreases in body size dissatisfaction (effect size of 1.08 vs. .41, p < .001) than the comparison group. Significant improvements were observed in both groups for all other psychosocial variables (effect sizes ranging from .31–.75, p < .05). Mediation analysis showed that changes in body image and body weight were concurrently mediators and outcomes of treatment, suggesting reciprocal influences. Weight loss partially mediated the effect of treatment on quality of life and on self-esteem but the reciprocal effect was not observed.</p> <p>Conclusion</p> <p>Changes in weight and body image may reciprocally affect each other during the course of behavioral obesity treatment. No evidence of reciprocal relationships was found for the other models under analysis; however, weight changes partially explained the effects of treatment on quality of life and self-esteem. Weight and psychosocial changes co-occur during treatment and will probably influence each other dynamically, in ways not yet adequately understood. Results from this study support the inclusion of intervention contents aimed at improving body image in weight management programs.</p

    LigASite—a database of biologically relevant binding sites in proteins with known apo-structures

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    Better characterization of binding sites in proteins and the ability to accurately predict their location and energetic properties are major challenges which, if addressed, would have many valuable practical applications. Unfortunately, reliable benchmark datasets of binding sites in proteins are still sorely lacking. Here, we present LigASite (‘LIGand Attachment SITE’), a gold-standard dataset of binding sites in 550 proteins of known structures. LigASite consists exclusively of biologically relevant binding sites in proteins for which at least one apo- and one holo-structure are available. In defining the binding sites for each protein, information from all holo-structures is combined, considering in each case the quaternary structure defined by the PQS server. LigASite is built using simple criteria and is automatically updated as new structures become available in the PDB, thereby guaranteeing optimal data coverage over time. Both a redundant and a culled non-redundant version of the dataset is available at http://www.scmbb.ulb.ac.be/Users/benoit/LigASite. The website interface allows users to search the dataset by PDB identifiers, ligand identifiers, protein names or sequence, and to look for structural matches as defined by the CATH homologous superfamilies. The datasets can be downloaded from the website as Schema-validated XML files or comma-separated flat files
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