The role of exciton delocalization in the major photosynthetic light-harvesting antenna of plants

In the major peripheral plant light-harvesting complex LHCII, excitation energy is transferred between chlorophylls along an energetic cascade before it is transmitted further into the photosynthetic assembly to be converted into chemical energy. The efficiency of these energy transfer processes involves a complicated interplay of pigment-protein structural reorganization and protein dynamic disorder, and the system must stay robust within the fluctuating protein environment. The final, lowest energy site has been proposed to exist within a trimeric excitonically coupled chlorophyll (Chl) cluster, comprising Chls a610-a611-a612. We studied an LHCII monomer with a site-specific mutation resulting in the loss of Chls a611and a612, and find that this mutant exhibits two predominant overlapping fluorescence bands. From a combination of bulk measurements, single-molecule fluorescence characterization, and modeling, we propose the two fluorescence bands originate from differing conditions of exciton delocalization and localization realized in the mutant. Disruption of the excitonically coupled terminal emitter Chl trimer results in an increased sensitivity of the excited state energy landscape to the disorder induced by the protein conformations. Consequently, the mutant demonstrates a loss of energy transfer efficiency. On the contrary, in the wildtype complex, the strong resonance coupling and correspondingly high degree of excitation delocalization within the Chls a610- a611-a612 cluster dampens the influence of the environment and ensures optimal communication with neighboring pigments. These results indicate that the terminal emitter trimer is thus an essential design principle for maintaining the efficient light-harvesting function of LHCII in the presence of protein disorder.VU University and by an Advanced Investigator grant from the European Research Council (No. 267333, PHOTPROT). Nederlandse Organisatie voor Wetenschappelijk Onderzoek, Council of Chemical Sciences (NWO-CW) via a TOP-grant (700.58.305), and by the EU FP7 project PAPETS (GA 323901). Netherlands Royal Academy of Sciences (KNAW).Earth and Life Sciences Council of the NWO (NWO-ALW).Consolidator Investigator grant from the European Research Council (No. 281341 ASAP).Czech Science Foundation (GACR, No. 14-25752S) and an NWO visitor grant 040.11.423 and grant 040.11.428.http://www.cell.combiophysj2016-03-31hb201

Cause of Death and Predictors of All-Cause Mortality in Anticoagulated Patients With Nonvalvular Atrial Fibrillation : Data From ROCKET AF

M. Kaste on työryhmän ROCKET AF Steering Comm jäsen.Background-Atrial fibrillation is associated with higher mortality. Identification of causes of death and contemporary risk factors for all-cause mortality may guide interventions. Methods and Results-In the Rivaroxaban Once Daily Oral Direct Factor Xa Inhibition Compared with Vitamin K Antagonism for Prevention of Stroke and Embolism Trial in Atrial Fibrillation (ROCKET AF) study, patients with nonvalvular atrial fibrillation were randomized to rivaroxaban or dose-adjusted warfarin. Cox proportional hazards regression with backward elimination identified factors at randomization that were independently associated with all-cause mortality in the 14 171 participants in the intention-to-treat population. The median age was 73 years, and the mean CHADS(2) score was 3.5. Over 1.9 years of median follow-up, 1214 (8.6%) patients died. Kaplan-Meier mortality rates were 4.2% at 1 year and 8.9% at 2 years. The majority of classified deaths (1081) were cardiovascular (72%), whereas only 6% were nonhemorrhagic stroke or systemic embolism. No significant difference in all-cause mortality was observed between the rivaroxaban and warfarin arms (P=0.15). Heart failure (hazard ratio 1.51, 95% CI 1.33-1.70, P= 75 years (hazard ratio 1.69, 95% CI 1.51-1.90, P Conclusions-In a large population of patients anticoagulated for nonvalvular atrial fibrillation, approximate to 7 in 10 deaths were cardiovascular, whereasPeer reviewe

Environmental Thematic Map Prediction and Easy Probabilistic Classification

Introduction ISOLA (Information System for the Orientation of Local Actions) was a project supported by the European Community (funds life98env/it/000098), coordinated by the Modena Municipality - Department for Environmental Control and Planning; the project aim was the definition and the implementation of a Geographical Information System finalized to: the analysis of environmental conditions and hazards; the analysis of pressure levels on the environment due to the human activities; the definition of methods and indicators suitable for the choice and the validation of environmental policies; the definition of methods and indicators suitable for the environmental evaluation of development policies. At the present the implemented system is being applied at the Modena Municipality and, in the future, will be made available to other administrations interested in applying it. The GIS core, i.e. the procedures finalized to the environmental analyses, ha been implemented as GRASS co

Low-Cost GNSS Receivers for Local Monitoring: Experimental Simulation, and Analysis of Displacements

The geodetic monitoring of local displacements and deformations is often needed for civil engineering structures and natural phenomena like, for example, landslides. A local permanent GNSS (Global Navigation Satellite Systems) network can be installed: receiver positions in the interest area are estimated and monitored with respect to reference stations. Usually, GNSS geodetic receivers are adopted and provide results with accuracies at the millimeter level: however, they are very expensive and the initial cost and the risk of damage and loss can discourage this approach. In this paper the accuracy and the reliability of low-cost u-blox GNSS receivers are experimentally investigated for local monitoring. Two experiments are analyzed. In the first, a baseline (65 m long) between one geodetic reference receiver and one u-blox is continuously observed for one week: the data are processed by hourly sessions and the results provide comparisons between two processing packages and a preliminary accuracy assessment. Then, a network composed of one geodetic and two u-blox receivers is set up. One u-blox is installed on a device (slide) that allows to apply controlled displacements. The geodetic and the other u-blox (at about 130 m) act as references. The experiment lasts about two weeks. The data are again processed by hourly sessions. The estimated displacements of the u-blox on the slide are analyzed and compared with the imposed displacements. All of the results are encouraging: in the first experiment the standard deviations of the residuals are smaller than 5 mm both in the horizontal and vertical; in the second, they are slightly worse but still satisfactory (5 mm in the horizontal and 13 mm in vertical) and the imposed displacements are almost correctly identified

OpenDiViSe (Discovery and view services): un prototipo di infrastruttura aperta per la Lombardia

Dal 25 al 27 febbraio 2009 si è svolto a Cagliari il X Meeting degli utenti italiani GRASS e GFOSS. L'evento rappresenta da dieci anni l'occasione principale in cui tutta la comunità italiana, attiva nel campo dell'informazione geografica libera, si riunisce per confrontarsi e discutere sugli sviluppi futuri nel settore. Il meeting è stato organizzato dal CRS4 (Centro di Ricerca, Sviluppo e Studi Superiori in Sardegna), con il patrocinio dell'Università degli Studi di Cagliari, di Sardegna Ricerche e dell'associazione GFOSS.it. Gli obiettivi del X Meeting comprendono la presentazione delle innovazioni GFOSS nei seguenti campi: Sviluppi e personalizzazioni di software GIS liberi; Dati geografici liberi; GFOSS per la pubblica amministrazione; Formazione, divulgazione e sensibilizzazione nel campo del software libero; Interoperabilità e standard; Informazione geografica diffusa: web 2.0, GPS, LBS, etc; Ambiente e territorio; Telerilevamento; Applicazioni di Geostatistica2009-02-27Facoltà di Ingegneria, Università degli Studi di Cagliari, Viale Merello, CagliariX Meeting degli utenti italiani GRASS e GFOS

On shallow-water wakes: an analytical study

International audienceAnalytical solutions for the characteristic scales of a turbulent wake in shallow flows are presented for two asymptotic cases: in one case, boundary-layer effects dominate whereas in the other, wake effects prevail. The latter case degenerates into the solution valid for an unbounded two-dimensional wake. These solutions show that the momentum deficit decreases exponentially in the longitudinal direction while the transverse velocity profile reveals a wake region characterized by a reduced velocity deficit compared to that of an unbounded wake. When wake-turbulence dominates there is a non-uniform turbulent viscosity in the longitudinal direction. These analytical solutions are compared with experimental data showing good agreement