Antiphase Synchronization in a Flagellar-Dominance Mutant of Chlamydomonas

Groups of beating flagella or cilia often synchronize so that neighboring filaments have identical frequencies and phases. A prime example is provided by the unicellular biflagellate Chlamydomonas reinhardtii, which typically displays synchronous in-phase beating in a low-Reynolds number version of breaststroke swimming. We report here the discovery that ptx1, a flagellar dominance mutant of C. reinhardtii, can exhibit synchronization in precise antiphase, as in the freestyle swimming stroke. Long-duration high-speed imaging shows that ptx1 flagella switch stochastically between in-phase and antiphase states, and that the latter has a distinct waveform and significantly higher frequency, both of which are strikingly similar to those found during phase slips that stochastically interrupt in-phase beating of the wildtype. Possible mechanisms underlying these observations are discussed.Comment: 5 pages, 4 figure

Antiphase synchronization in a flagellar-dominance mutant of Chlamydomonas

Groups of beating flagella or cilia often synchronize so that neighboring filaments have identical frequencies and phases. A prime example is provided by the unicellular biflagellate Chlamydomonas reinhardtii, which typically displays synchronous in-phase beating in a low-Reynolds number version of breaststroke swimming. We report the discovery that ptx1, a flagellar-dominance mutant of C. reinhardtii, can exhibit synchronization in precise antiphase, as in the freestyle swimming stroke. High-speed imaging shows that ptx1 flagella switch stochastically between in-phase and antiphase states, and that the latter has a distinct waveform and significantly higher frequency, both of which are strikingly similar to those found during phase slips that stochastically interrupt in-phase beating of the wild-type. Possible mechanisms underlying these observations are discussed. Published by the American Physical Society under the terms of the Creative Commons Attribution 3.0 License. Further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation, and DOI.Support is acknowledged from the Spanish Ministerio de Ciencia y Innovación Grant No. FIS2010-22322-C01 and a Ramón y Cajal Fellowship (I. T.), an EPSRC postdoctoral Fellowship (M. P.), the BBSRC, the EPSRC, ERC Advanced Investigator Grant No. 247333, and a Senior Investigator Award from the Wellcome Trust (R. E. G.)Peer Reviewe

Monitoring of a coastal zone by independent fast photogrammetric surveys: The case of Monterosso a Mare (Ligurian Sea, Italy)

The Structure-from-Motion photogrammetry (SfM) allows a fast and easy data acquisition and a highly automated data processing, leading to accurate photorealistic point clouds. The results of a SfM-based modeling of the coastal zone of Monterosso a Mare (Eastern Liguria, Italy) are shown here. Four photogrammetric surveys of the area were carried out from both moving surface (boat) and aerial (Unmanned Aerial Vehicle) platforms. The corresponding results were compared in order to provide information about precision and model reliability from fast ad cheap SfM surveys carried out without Ground Control Points (GCPs). The important issue of scale factor evaluation was solved by means of selection of points easily recognizable in each point cloud and measurement of the length of the polyline that connects these points. The ratio between the lengths of the polyline defined on a point cloud and the corresponding polyline defined in a metric reference frame provided the scale factor. The results highlight that the SfM technique can be used in emergency conditions, where GCPs cannot be used, and is compatible with a floating platform-based observation, leading to point clouds whose resolution is some centimeters for an acquisition distance of 100-150 m.Published73-817A. Geofisica per il monitoraggio ambientaleN/A or not JC

Interstitial Lung Disease Associated With Autoimmune Rheumatic Diseases: Checklists for Clinical Practice

Background: Interstitial lung diseases (ILDs) are often associated with rheumatic diseases. Their early diagnosis and management are not only difficult, but also crucial, because they are associated with major morbidity and mortality and can be the first cause of death in autoimmune rheumatic diseases (ARDs). Objectives: By using methodologies, such as Nominal Group Technique (NGT) and Delphi Survey, the aims of this study were (1) to measure consensus between pulmonologists, radiologists, and rheumatologists experienced in the management of ARD-ILD; (2) to highlight the importance of a multidisciplinary approach; and (3) to provide clinicians with a practical tool aimed at improving the prompt recognition and follow-up of ILD associated with ARDs and of any possible rheumatic conditions underlying ILD. Results: During the NGT round, the Steering Committee defined 57 statements to be used in the Delphi survey. A total of 78 experts participated in the Delphi survey, namely 28 pulmonologists, 33 rheumatologists, and 17 radiologists. During this round, consensus on agreement was reached in 47 statements, while disagreement was not reached in any statements. A secondary questionnaire was drafted by the Steering Committee to obtain clearer indications on ILD-ARD \u201cred-flags\u201d and follow-up. Delphi Panelists took part also in the second-questionnaire survey. Answers from both surveys were used to draft two checklists of \u201cred flags\u201d sign or symptom suggestive of ILD and ARD, respectively, and two checklists on identification and monitoring of rheumatoid arthritis (RA) and systemic sclerosis (SSc) ILD. Limitations: This study is a consensus work, which cannot produce empiric data, and is limited to the Italian scenario. Conclusions: This work showed a high level of agreement, but also shows some divergent opinions between different experts. This underlines the importance of a multidisciplinary approach. Eventually, we believe the drafted checklists can help clinicians in the diagnosis and follow-up of ILD-ARD

Geodetic deformation Across the Central Apennines from GPS Data in the time span 1999-2003

Abstract During the time span 1999-2003 was set up and repeatedly surveyed a not permanent GPS network located across one of the highest seismic areas of the central Apennines (Italy). The Central Apennine Geodetic Network (CA-GeoNet), extends across Umbria, Abruzzo, Marche and Lazio regions, in an area of ?180x130 km, from Tyrrhenian to the Adriatic sea. It consists in 125 GPS stations distributed at 3-5 km average grid and includes 7 permanent GPS stations operated by the Italian Space Agency (ASI) and the Istituto Nazionale di Geofisica and Vulcanologia (INGV). With the aim to estimate the active strain rate across this part of the chain, the GPS sites have been located on the main geological units of the area and across the typical basin and range structures, related with the main seismogenic faults. In this paper we show the network and the first results obtained for a subset of 23 stations that have been occupied at least during three repeated campaigns, in the time span 1999-2003. Data analysis, performed by Bernese 4.2 software, shows an extensional rate normal to the chain, in agreement with geological and seismic data. The strain rates in the inner chain are ranging from 12x10-9±11yr-1 to 16x10-9±11yr-1 and from -14x10-9±11yr-1 to -3x10-9±11yr-1. This result provides an improved estimation of the ongoing deformation of this area with respect to previous studies and is in agreement with the style of deformation inferred from seismicity and with the features of the main seismogenic sources from recent geological and seismological investigations

Photogrammetric Surveys: the Case of Monterosso a Mare (Ligurian Sea, Italy)

Abstract The Structure-from-Motion photogrammetry (SfM) allows a fast and easy data acquisition and a highly automated data processing, leading to accurate photorealistic point clouds. The results of a SfM-based modeling of the coastal zone of Monterosso a Mare (Eastern Liguria, Italy) are shown here. Four photogrammetric surveys of the area were carried out from both moving surface (boat) and aerial (Unmanned Aerial Vehicle) platforms. The corresponding results were compared in order to provide information about precision and model reliability from fast ad cheap SfM surveys carried out without Ground Control Points (GCPs). The important issue of scale factor evaluation was solved by means of selection of points easily recognizable in each point cloud and measurement of the length of the polyline that connects these points. The ratio between the lengths of the polyline defined on a point cloud and the corresponding polyline defined in a metric reference frame provided the scale factor. The results highlight that the SfM technique can be used in emergency conditions, where GCPs cannot be used, and is compatible with a floating platform-based observation, leading to point clouds whose resolution is some centimeters for an acquisition distance of 100-150 m

GPS surveys in the foreland-foredeep tectonic system of Southeastern Sicily: first results

The Hyblean plateau (Southeastern Sicily) is characterised by three main tectonic structural trends: the first, NNW-SSE striking, runs on the easternmost part of the plateau and is linked to the Hyblean-Maltese fault system; the second runs along the western part of the plateau with a NNE-SSW direction and is characterised by a sinistral strike slip motion, like the Scicli fault; the third ENE-WSW striking, characterises the northernmost part of the area, including the Scordia-Lentini graben. We analysed GPS data collected in a dense network located in the northern area of the Hyblean plateau during 1998 and 2000, between the towns of Catania and Syracuse. Data from Noto, Matera and Cagliari IGS stations, were included in the processing to connect this network to the International Terrestrial Reference Frame (ITRF). The comparison between 1998 and 2000 data sets shows an average northward motion of the GPS stations located south of the Gela-Catania foredeep. Site velocities decrease from south to north and show a weak internal deformation of the northernmost part of the Hyblean plateau