Evaluation of the progression of visual field damage in patients suffering from early manifest glaucoma

Abstract BACKGROUND: This retrospective study aimed to determine how often a perimetric examination should be carried out in order to identify visual field (VF) changes in patients with relatively early manifestation glaucoma. MATERIALS AND METHODS: Patients included had a relatively recent manifestation of primary open-angle glaucoma. Patients with a minimum follow-up of 5 years and a minimum of seven VF tests were included. Statistical analysis was performed to verify the trend of variations in mean defect (MD) over time (PeriData). The results were subjected to a t-test for a comparative analysis of progression of VF changes over time. The annual rate of progression provided by PeriData considering all the VFs analyzed was compared with that obtained on half of the VF examinations during the same follow-up period. An analysis of the MD trend over time was also carried out in relationship to the number of VF tests done and by dividing the sample into a high-frequency group (more than eight VFs) and a low-frequency group (fewer than eight VFs) in the follow-up period. RESULTS: A total of 96 eyes of 96 patients were included, and overall 846 VFs were examined. The paired t-test performed comparing the MD index of all the VFs against half of them did not show statistical significance (P=0.537). The high-frequency group comprised 39 eyes (average VF 11.05±1.91, average time interval 0.76 years) while the low-frequency group comprised 57 eyes (average VF 6.95±0.6, average time interval 1.21 years). The analysis of the MD trend in the high-frequency patients showed significance (P=0.017); the low-frequency group did not show statistical significance (P=0.08). CONCLUSION: The number of VFs in a determined time interval was not significant. However, a greater frequency of tests provides a predictive evaluation of the rate of progression of early manifestation open-angle glaucoma

A square for people a visually communicative, configuration informed and social-oriented redevelopment project for Largo da Graça, Lisbon

This paper describes an experimental project in which the urban designer uses Space Syntax and other analysis techniques coming from Public Life Studies and Building Thermal Physics, to inform the Design Decision-Making for the redevelopment of a public square. Largo da Graça in the historic centre of Lisbon was selected as a case study, suitable for testing many possible and different design changes when space syntax is embedded in the design decisions. The experiment generated a digital workflow with all the steps undertaken in solving design problems, a ‘design journal’ that includes efficiency targets (centrality, connectivity, enclosure, thermal comfort, social security, equality, and interaction) and a comparative test of the design proposals. The adopted design strategy, as well as the examples extracted from the workflow, could be used to illustrate a link between research and design, adequate for supporting and orientating the project and design of urban spaces

Functional biases in GRB's spectral parameter correlations

Gamma Ray Bursts (GRBs) show evidence of different spectral shapes, light curves, duration, host galaxies and they explode within a wide redshift range. However, the most of them seems to follow very tight correlations among some observed quantities relating to their energetic. If true, these correlations have significant implications on burst physics, giving constraints on theoretical models. Moreover, several suggestions have been made to use these correlations in order to calibrate GRBs as standard candles and to constrain the cosmological parameters. We investigate the cosmological relation between low energy $\alpha$ index in GRBs prompt spectra and the redshift $z$. We present a statistical analysis of the relation between the total isotropic energy $E_{iso}$ and the peak energy $E_p$ (also known as Amati relation) in GRBs spectra searching for possible functional biases. Possible implications on the $E_{iso}$ vs $E_p$ relation of the $\alpha$ vs $(1+z)$ correlation are evaluated. We used MonteCarlo simulations and the boostrap method to evaluate how large are the effects of functional biases on the $E_{iso}$ vs $E_p$. We show that high values of the linear correlation coefficent, up to about 0.8, in the $E_{iso}$ vs $E_p$ relation are obtained for random generated samples of GRBs, confirming the relevance of functional biases. Astrophysical consequences from $E_{iso}$ vs $E_p$ relation are then to be revised after a more accurate and possibly bias free analysis.Comment: 6 pages, 6 figures, conference poster session: "070228: The Next Decade of Gamma-Ray Burst Afterglows", Amsterdam, March 2007, MNRAS submitte

Systematic search for gamma-ray periodicity in active galactic nuclei detected by the Fermi Large Area Telescope

We use nine years of gamma-ray data provided by the Fermi Large Area Telescope (LAT) to systematically study the light curves of more than two thousand active galactic nuclei (AGN) included in recent Fermi-LAT catalogs. Ten different techniques are used, which are organized in an automatic periodicity-search pipeline, in order to search for evidence of periodic emission in gamma rays. Understanding the processes behind this puzzling phenomenon will provide a better view about the astrophysical nature of these extragalactic sources. However, the observation of temporal patterns in gamma-ray light curves of AGN is still challenging. Despite the fact that there have been efforts on characterizing the temporal emission of some individual sources, a systematic search for periodicities by means of a full likelihood analysis applied to large samples of sources was missing. Our analysis finds 11 AGN, of which 9 are identified for the first time, showing periodicity at more than 4sigma in at least four algorithms. These findings will help in solving questions related to the astrophysical origin of this periodic behavior.Comment: 16 pages, 5 figures, 4 tables. Accepted by Ap

Analysis of driving seat vibrations in different transfer conditions

The vibration transmitted through the seat of a four-wheel drive tractor, developing 179 kW, and equipped with front suspension axle and shock absorber for the implement, were measured and analysed according to the ISO standard. Several tests were carried out in different conditions considering: type of operation (transfer with and without mounted implement); type of track (conglomerate bituminous road, country lane); connected and disconnected suspension and/or shock absorber; and forward speeds. For the transfer on bituminous conglomerate road, it was observed that the suspension always reduces acceleration av, in both tests without and with implement, for all the considered forward speeds. For the tests conduced on country lane, the front axle suspension involved a reduction of the acceleration, but it was less evident than on the road Results showed that the forward speed and the mass distribution were the most important factors on tractor behaviour influencing the driver comfort. The daily exposure time which could compromise the driver's health increased from 2.5 to 8 h decreasing the speed from 3.06 to 2.22 m/s during transfer in country lane without implement. In the other condition the time exposure is approximately more than a working day

Effect of forest structure and management on the functional diversity and composition of understorey plant communities

Questions Do forest structural parameters related to stand heterogeneity enhance functional diversity (FD) of understorey plant communities? Do FD and functional composition of understorey plant communities vary between high-forest (HF) and old coppices-with-standard (oldCWS) management types? Are HF stands characterized by a higher FD than oldCWS? Location Submediterranean beech forests of Montagne della Duchessa Reserve (central Italy). Methods We sampled 57 (20 m × 20 m) forest plots, 29 oldCWS and 28 HF stands, where we recorded plant species cover abundance. We used Leaf–Height–Seed and clonal traits, and run multiple separate linear models to quantify the effect of forest structural parameters and management types on FD and functional composition of understorey plant communities. Results We found that increasing lying deadwood enhanced FD of specific leaf area (SLA) through micro-environmental heterogeneity of soil fertility regardless of management type. We also found that increased horizontal stratification filtered the range of plant sizes, probably through light reduction. HF management enhanced FD of SLA and clonal traits through micro-environmental heterogeneity, while reducing the FD of plant size and seed mass. HF tended to select plant communities characterized by high resource acquisition strategies but lower persistence between ramets, possibly as an effect of more mature forest conditions. Conclusion Our study suggests that understorey plant community diversity and composition change in response to forest structure and management. Combining Leaf–Height–Seed with clonal traits offers a promising framework for understanding and predicting plant response to management practices

Urban squares morphologies, contributes of a multidimensional analysis

The word Square and the Latin – platea – derived terms (piazza, plaza, praça, piaţă) are used to identify a public space of an exceptional character that is morphologically distinct in the urban morphology. The study of urban morphology seeks to understand the spatial structure and character of the city by identifying the patterns of its elements and the process of its development. The characterizing traits of the urban square are diverse and their origin twofold: global properties, referred to its relationships within the whole grid, and local properties, depending on the intrinsic morphologic features of its space; what requires a multi-dimensional and multi-scale approach. This paper will present a multidimensional analysis of two Italian Tuscan historic squares and two Portuguese historic squares. The squares will be analysed from a simultaneous view of their attributes. Thus, it is proposed, in an ongoing joint research project, to address the limitations of traditional-descriptive urban morphology in dealing with this simultaneity. Developing the relations between formal attributes and intangible spatial properties, their identity and closeness may be disclosed by multivariate statistical analysis and computational techniques.info:eu-repo/semantics/acceptedVersio