1,518 research outputs found
Parental evaluation of a telemonitoring service for children with Type 1 Diabetes
Introduction In the past years, we developed a telemonitoring service for young patients affected by Type 1 Diabetes. That service provides data to the clinical staff and offers an important tool to the parents, that are able to oversee in real time their children. The aim of this work was to analyze the parents' perceived usefulness of the service. Methods The service was tested by the parents of 31 children enrolled in a seven-day clinical trial during a summer camp. To study the parents' perception we proposed and analyzed two questionnaires. A baseline questionnaire focused on the daily management and implications of their children's diabetes, while a post-study one measured the perceived benefits of telemonitoring. Questionnaires also included free text comment spaces. Results Analysis of the baseline questionnaires underlined the parents' suffering and fatigue: 51% of total responses showed a negative tendency and the mean value of the perceived quality of life was 64.13 in a 0-100 scale. In the post-study questionnaires about half of the parents believed in a possible improvement adopting telemonitoring. Moreover, the foreseen improvement in quality of life was significant, increasing from 64.13 to 78.39 ( p-value\u2009=\u20090.0001). The analysis of free text comments highlighted an improvement in mood, and parents' commitment was also proved by their willingness to pay for the service (median\u2009=\u2009200\u2009euro/year). Discussion A high number of parents appreciated the telemonitoring service and were confident that it could improve communication with physicians as well as the family's own peace of mind
A Kinematic Approach to Determining the Optimal Actuator Sensor Architecture for Space Robots
Autonomous space robots will be required for such future missions as the construction of large space structures and repairing disabled satellites. These robots will need to be precisely controlled. However, factors such as manipulator joint/actuator friction and spacecraft attitude control thruster inaccuracies can substantially degrade control system performance. Sensor-based control algorithms can be used to mitigate the effects of actuator error, but sensors can add substantially to a space system’s weight, complexity, and cost, and reduce its reliability. Here, a method is presented to determine the sensor architecture that uses the minimum number of sensors that can simultaneously compensate for errors and disturbance in a space robot’s manipulator joint actuators, spacecraft thrusters, and reaction wheels. The placement and minimal number of sensors is determined by analytically structuring the system into “canonical chains” that consist of the manipulator links and spacecraft with force/torque sensors placed between the space robot’s spacecraft and its manipulators. These chains are combined to determine the number of sensors needed for the entire system. Examples of one- and two-manipulator space robots are studied and the results are validated by simulation
Molecular details of the unique mechanism of chloride transport by acyanobacterial rhodopsin
Microbial rhodopsins are well known as versatile and ubiquitous light-driven
ion transporters and photosensors. While the proton transport mechanism has
been studied in great detail, much less is known about various modes of anion
transport. Until recently, only two main groups of light-driven anion pumps
were known, archaeal halorhodopsins (HRs) and bacterial chloride pumps (known
as ClRs or NTQs). Last year, another group of cyanobacterial anion pumps with
a very distinct primary structure was reported. Here, we studied the chloride-
transporting photocycle of a representative of this new group,
Mastigocladopsis repens rhodopsin (MastR), using time-resolved spectroscopy in
the infrared and visible ranges and site-directed mutagenesis. We found that,
in accordance with its unique amino acid sequence containing many polar
residues in the transmembrane region of the protein, its photocycle features a
number of unusual molecular events not known for other anion-pumping
rhodopsins. It appears that light-driven chloride ion transfers by MastR are
coupled with translocation of protons and water molecules as well as
perturbation of several polar sidechains. Of particular interest is transient
deprotonation of Asp-85, homologous to the cytoplasmic proton donor of light-
driven proton pumps (such as Asp-96 of bacteriorhodopsin), which may serve as
a regulatory mechanism
Performance improvement of the multicell cavity prototype for proton Linac projects
The CEA-Saclay / IPN-Orsay collaboration allowed to manufacture a multicell superconducting RF cavity prototype for proton linac. Since the first experimental results [1], obtained in a vertical cryostat and the horizontal cryostat CryHoLab, the accelerating field Eacc has been recently increased up to 19 MV/m with a quality factor Q0 = 9.109 and a limitation by quench. However some improvements are still needed, in particular to suppress the field emission above 16 MV/m
Synthesis, photophysical characterisation and metal ion binding properties of new ligands containing anthracene chromophores
Model for initiation of quality factor degradation at high accelerating fields in superconducting radio-frequency cavities
A model for the onset of the reduction in SRF cavity quality factor, the
so-called Q-drop, at high accelerating electric fields is presented. Breakdown
of the surface barrier against magnetic flux penetration at the cavity equator
is considered to be the critical event that determines the onset of Q-drop. The
worst case of triangular grooves with low field of first flux penetration Hp,
as analyzed previously by Buzdin and Daumens, [1998 Physica C 294: 257], was
adapted. This approach incorporates both the geometry of the groove and local
contamination via the Ginzburg-Landau parameter kappa, so the proposed model
allows new comparisons of one effect in relation to the other. The model
predicts equivalent reduction of Hp when either roughness or contamination were
varied alone, so smooth but dirty surfaces limit cavity performance about as
much as rough but clean surfaces do. When in combination, contamination
exacerbates the negative effects of roughness and vice-versa. To test the model
with actual data, coupons were prepared by buffered chemical polishing and
electropolishing, and stylus profilometry was used to obtain distributions of
angles. From these data, curves for surface resistance generated by simple flux
flow as a function of magnetic field were generated by integrating over the
distribution of angles for reasonable values of kappa. This showed that
combined effects of roughness and contamination indeed reduce the Q-drop onset
field by ~30%, and that that contamination contributes to Q-drop as much as
roughness. The latter point may be overlooked by SRF cavity research, since
access to the cavity interior by spectroscopy tools is very difficult, whereas
optical images have become commonplace. The model was extended to fit cavity
test data, which indicated that reduction of the superconducting gap by
contaminants may also play a role in Q-drop.Comment: 15 pages with 7 figure
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Real-time smart and standalone vision/IMU navigation sensor
In this paper, we present a smart, standalone, multi-platform stereo vision/IMU-based navigation system, providing ego-motion estimation. The real-time visual odometry algorithm is run on a nano ITX single-board computer (SBC) of 1.9 GHz CPU and 16-core GPU. High-resolution stereo images of 1.2 megapixel provide high-quality data. Tracking of up to 750 features is made possible at 5 fps thanks to a minimal, but efficient, features detection–stereo matching–feature tracking scheme runs on the GPU. Furthermore, the feature tracking algorithm benefits from assistance of a 100 Hz IMU whose accelerometer and gyroscope data provide inertial features prediction enhancing execution speed and tracking efficiency. In a space mission context, we demonstrate robustness and accuracy of the real-time generated 6-degrees-of-freedom trajectories from our visual odometry algorithm. Performance evaluations are comparable to ground truth measurements from an external motion capture system
High-resolution calcareous nannofossil biostratigraphy across the Toarcian Oceanic Anoxic Event in northern Italy: clues from the Sogno and Gajum Cores (Lombardy Basin, Southern Alps)
Calcareous nannofossil biostratigraphy was conducted across the toarcian oceanic anoxic event (t-oae) interval cored at Colle di Sogno and Gajum in the lombardy basin (Southern alps, northern italy). Drilling at both sites resulted in 100% recovery of unweathered material. the Sogno and Gajum Cores consist of pelagic marly limestones, marlstone, marly claystone, and a relatively expanded black shale interval named fish level considered the lithostratigraphic record of the t-oae at regional scale.Semiquantitative analyses of calcareous nannofloras allowed to achieve a high-resolution biostratigraphy of the latest Pliensbachian-early toarcian time interval. Several nannofossil biohorizons were detected, including zonal/subzonal markers and additional events related to changes in abundance. the nannofossil biostratigraphic correlation of the Sogno and Gajum Cores indicates that, according to their paleogeographic settings, the succession recovered in the Sogno Core deposited on a pelagic plateau is continuous while a hiatus of ~600 kyrs was detected in the lower-most toarcian in the Gajum Core located on a slope of a structural high.the nJt 5 and nJt 6 Zones of the standard nannofossil zonation for the Mediterranean Province were identified in both the Sogno and Gajum Cores. Our findings allow an implementation of the reference biozonation with the separation of the nJt 6a and nJt 6b Subzones, and age revision of some secondary events. the zonation established for the Lusitanian Basin (Portugal) is only partially reproducible in the Lombardy Basin, confirming nan-noplankton paleoprovincialism during the early Jurassic requiring different zonal schemes in various areas. neverthe-less, we underline that the t-oae is unambiguously constrained by the fo of C. superbus crassus and the lo of M. jansae at supra-regional scale
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