324 research outputs found
Lasing properties and nonlinearities of dyes under high power pumping
AbstractNitrogen lasers have been used for many years to make dye solutions lase. A nitrogen laser, which transverse electrical discharge in gas at atmospheric pressure has been built in our laboratory. It has been characterized and applied to pump different dyes: Rhodamine 6G, Coumarin 440, DOTCI, and pyranine in simple "on axis" geometric configuration. It has been shown that pyranine can lase in the absence of any optical external mirror cavity, this happens at very low threshold, and in different solvents. Dyes under consideration can be grouped into two major classes according to their lasing behavior independently on their concentration in the solvent: Rhodamine 6G and DOTCI can lase both axially or transversally and Coumarin 440 and pyranine can lase only axially. Other intriguing features have been observed that span from simultaneous multiple beam generation, to super fluorescence and to distribute axial pumping of dye solutions. A preliminary basis for understanding and controlling such processes is the spatial energy distribution and the energy density of the beam
Blue Horizontal Branch Stars in the Sagittarius dwarf spheroidal galaxy
We report on the recovery of a Blue Horizontal Branch (BHB) population
belonging to the Sagittarius Dwarf Spheroidal Galaxy (Sgr). The sequence is
clearly identified in the (V, V-I) Color Magnitude Diagram (CMD) obtained for
about 500,000 stars in the region of the globular cluster M~54. The BHB
morphology is similar to the analogous sequence in M~54, but it is
unambiguously associated with Sgr since {\it(i)} it is detected well outside
the main body of the cluster, up to more than 5 tidal radii from the cluster
center and {\it(ii)} the BHB stars follow the radial distribution of the other
stellar populations of Sgr. This finding finally demonstrates that the Sgr
galaxy hosts a significant (of the order of 10%) old and metal-poor
stellar population ([Fe/H]\ltsima -1.3; age \gtsima 10 Gyr), similar to that of
its oldest clusters (M~54, Ter~8). We also show that the Sgr BHB sequence found
here is the counterpart of the analogous feature observed by Newberg et al.
(2002) in the Sgr Stream, in a field more than 80\degr away from the center
of the galaxy.Comment: 12 pages, 4 figures. Accepted for publication in ApJ Letter
DIAMIN: a software library for the distributed analysis of large-scale molecular interaction networks
Background Huge amounts of molecular interaction data are continuously produced and stored in public databases. Although many bioinformatics tools have been proposed in the literature for their analysis, based on their modeling through different types of biological networks, several problems still remain unsolved when the problem turns on a large scale. Results We propose DIAMIN, that is, a high-level software library to facilitate the development of applications for the efficient analysis of large-scale molecular interaction networks. DIAMIN relies on distributed computing, and it is implemented in Java upon the framework Apache Spark. It delivers a set of functionalities implementing different tasks on an abstract representation of very large graphs, providing a built-in support for methods and algorithms commonly used to analyze these networks. DIAMIN has been tested on data retrieved from two of the most used molecular interactions databases, resulting to be highly efficient and scalable. As shown by different provided examples, DIAMIN can be exploited by users without any distributed programming experience, in order to perform various types of data analysis, and to implement new algorithms based on its primitives. Conclusions The proposed DIAMIN has been proved to be successful in allowing users to solve specific biological problems that can be modeled relying on biological networks, by using its functionalities. The software is freely available and this will hopefully allow its rapid diffusion through the scientific community, to solve both specific data analysis and more complex tasks
A Cross-Sectional Survey on Burnout Prevalence and Profile in the Sicilian Population of Ambulance Driver-Rescuers
Introduction: Burnout is present at a high rate in emergency medicine. The ambulance
driver-rescuers, who furnish first aid to the victims, are the non-medical part of the
Italian 118-service staff. There is a lack of research on burnout risk in Italian Emergency
Medical Services and, particularly, for this category of workers. The two Italian studies,
including a little group of ambulance driver-rescuers, reported inconsistent findings.
Hypothesis: This survey investigated for the first time the prevalence and exact profile of
burnout in a large sample of Italian driver-rescuers. As a secondary aim, the study described
how the items of the Italian version of the Maslach Burnout Inventory-Human Services
Survey (MBI-HSS) cluster in components in this sample.
Methods: This cross-sectional census survey was conducted from June 2015 through May
2016 and involved all the driver-rescuers operating in Sicily, the biggest and most southern
region of Italy. The subjects received a classification according to different profiles of burnout by using the Italian version of the MBI-HSS (burnout, engagement, disengagement,
over-extension, and work-inefficacy). In order to explore the existence of independent
factors, a Principal Component Analysis (PCA) was conducted on the survey to obtain
eigenvalues >one for each component in the data.
Results: The final sample comprised 2,361 responders (96.6% of the initial sample). Of them,
29.8% were in burnout (95% confidence interval [CI], 27.8% to 31.8%) and 1.7% presented a
severe form (95% CI, 1.1% to 2.3%); 30.0% were engaged in their work (95% CI, 21.0% to
34.8%), 24.7% of responders were disengaged (95% CI, 22.9% to 26.5%), 1.2% presented an
over-extension profile (95% CI, 0.8% to 1.7%), and 12.6% felt work-inefficacy (95% CI,
11.3% to 14.1%). The factors loaded into a five-factor solution at PCA, explaining 48.1%
of the variance and partially replicating the three-factor structure. The Emotional
Exhaustion (EE) component was confirmed. New dimensions from Personal
Accomplishment (PA) and Depersonalization (DP) sub-scales described empathy and disengagement with patients, respectively, and were responsible for the increased risk of burnout.
Conclusions: These results endorse the importance of screening and psychological interventions for this population of emergency workers, where burnout could manifest itself more
insidiously. It is also possible to speculate that sub-optimal empathy skills could be related to
the disengagement and work-inefficacy feelings registered
Interaction with smart assistants using alternative and augmentative communication
Smart assistants utilize speech recognition, sensing, artificial intelligence, and networking technologies to enable improved human-machine interaction. However, there remain use cases where smart assistants are not easily usable by humans. For example, voice-activated assistants are not accessible to those that are hearing or speech impaired. Touchscreen based assistants are not usable by those who lack fine motor skills and/or reading ability.
This disclosure adds to the modalities by which humans can control and communicate with smart assistants by enabling use of physical objects, facial expressions, gross motor skills, body movements, etc. to provide commands. Collectively, these techniques of control and communication are referred to as alternative and augmentative communication (AAC)
On the potential and limitations of quantum extreme learning machines
Quantum reservoir computers (QRC) and quantum extreme learning machines
(QELM) aim to efficiently post-process the outcome of fixed -- generally
uncalibrated -- quantum devices to solve tasks such as the estimation of the
properties of quantum states. The characterisation of their potential and
limitations, which is currently lacking, will enable the full deployment of
such approaches to problems of system identification, device performance
optimization, and state or process reconstruction. We present a framework to
model QRCs and QELMs, showing that they can be concisely described via single
effective measurements, and provide an explicit characterisation of the
information exactly retrievable with such protocols. We furthermore find a
close analogy between the training process of QELMs and that of reconstructing
the effective measurement characterising the given device. Our analysis paves
the way to a more thorough understanding of the capabilities and limitations of
both QELMs and QRCs, and has the potential to become a powerful measurement
paradigm for quantum state estimation that is more resilient to noise and
imperfections.Comment: 12 pages, 7 figures, comments welcom
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