1,511 research outputs found
Deep reinforcement learning control of white-light continuum generation
White-light continuum (WLC) generation in bulk media finds numerous applications in ultrafast optics and spectroscopy. Due to the complexity of the underlying spatiotemporal dynamics, WLC optimization typically follows empirical procedures. Deep reinforcement learning (RL) is a branch of machine learning dealing with the control of automated systems using deep neural networks. In this Letter, we demonstrate the capability of a deep RL agent to generate a long-term-stable WLC from a bulk medium without any previous knowledge of the system dynamics or functioning. This work demonstrates that RL can be exploited effectively to control complex nonlinear optical experiments
Genetic characterization of four native Italian shepherd dog breeds and analysis of their relationship to cosmopolitan dog breeds using microsatellite markers
Very little research into genetic diversity of Italian native dog breeds has been carried out so far. In this study we aimed to estimate and compare the genetic diversity of four native Italian shepherd dog breeds: the Maremma, Bergamasco, Lupino del Gigante and Oropa shepherds. Therefore, some cosmopolitan dog breeds, which have been widely raised in Italy for a long time past, have also been considered to check possible influence of these dog populations on the Italian autochthonous breeds considered here. A total of 212 individuals, belonging to 10 different dog breeds, were sampled and genotyped using 18 autosomal microsatellite loci. We analyzed the genetic diversity of these breeds, within breed diversity, breed relationship and population structure. The 10 breeds considered in this study were clearly genetically differentiated from each other, regardless of current population sizes and the onset of separate breeding history. The level of genetic diversity explained 20% of the total genetic variation. The level of H E found here is in agreement with that found by other studies. The native Italian breeds showed generally higher genetic diversity compared with the long established, well-defined cosmopolitan dog breeds. As the Border Collie seems closer to the Italian breeds than the other cosmopolitan shepherd dogs considered here, a possible utilization of this breed to improve working performance in Italian traditional working shepherd dogs cannot be ignored. The data and information found here can be utilized in the organization of conservation programs planned to reduce inbreeding and to minimize loss of genetic variability
Molecular Response in One-Photon Absorption via Natural Thermal Light vs Pulsed Laser Excitation
Photoinduced biological processes occur via one photon absorption in natural
light, which is weak, CW and incoherent, but are often studied in the
laboratory using pulsed coherent light. Here we compare the response of a
molecule to these two very different sources within a quantized radiation field
picture. The latter is shown to induce coherent time evolution in the molecule,
whereas the former does not. As a result, the coherent time dependence observed
in the laboratory experiments will not be relevant to the natural biological
process. Emphasis is placed on resolving confusions regarding this issue that
are shown to arise from aspects of quantum measurement and from a lack of
appreciation of the proper description of the absorbed photon.Comment: Revised (now published) manuscript: Replaces ArXiv:1109.002
A comparison of seismic risk maps for Italy
National seismic risk maps are an important risk mitigation tool as they can be used for the prioritization of regions within a country where retrofitting of the building stock or other risk mitigation measures should take place. The production of a seismic risk map involves the convolution of seismic hazard data, vulnerability predictions for the building stock and exposure data. The seismic risk maps produced in Italy over the past 10 years are compared in this paper with recent proposals for seismic risk maps based on state-of-the-art seismic hazard data and mechanics-based vulnerability assessment procedures. The aim of the paper is to open the discussion for the way in which future seismic risk maps could be produced, making use of the most up-to-date information in the fields of seismic hazard evaluation and vulnerability assessment
Clinical Outcomes of Shunting in Normal Pressure Hydrocephalus. A Multicenter Prospective Observational Study
Background: Normal pressure hydrocephalus (NPH) is characterized by the triad of dementia, gait disturbance and urinary incontinence, all potentially reversible following a ventricu-loperitoneal shunt (VPS). This study aims to evaluate the clinical outcomes of shunting in normal pressure hydrocephalus following a new standardized protocol. Methods: This study is designed according to the STROBE guidelines. Demographical, clinical, surgical and radiological data were collected from May 2015 to November 2019. Gait, balance and incontinence data based on the NPH European scale were collected before and after one, six and twelve months of treatment with a VPS. Clinical symptoms and changes of the stoke volume, measured on phase-contrast MRI, were used to evaluate improvement after VPS surgery. Results: One hundred and eighty-one consecutive patients met the inclusion criteria. The mean age was 73.1 years (59–86) and mean follow-up was 38.3 months (13–50). The gait (58.5 ± 14.3 to 70.1 ± 13.4, p < 0.001), the balance (66.7 ± 21.5 to 71.7 ± 22.1, p = 0.001), continence domain (69.9 ± 20.5 to 76 ± 20, p = 0.002) scores and neuropsychological scales showed a statistically significant improvement over the follow-up. The overall improvement after 12 months was present in 91.2% of patients. An overall complication rate of 8.8% and a reoperation rate of 9.4% were recorded, respectively. Conclusions: Surgical treatment by VPS for NPH improves symptoms in most patients, when accurately selected. A standardized protocol and a multidisciplinary team dedicated to this disorder is needed to achieve an early and correct diagnosis of NPH. Follow-up with stroke volume measurement is a valuable tool for the early diagnosis of shunt malfunction or the need for valve adjustment
A Stimulated Raman Loss spectrometer for metrological studies of quadrupole lines of hydrogen isotopologues
We discuss layout and performance of a high-resolution Stimulated Raman Loss
spectrometer that has been newly developed for accurate studies of spectral
lineshapes and line center frequencies of hydrogen isotopologues and in general
of Raman active transitions. Thanks to the frequency comb calibration of the
detuning between pump and Stokes lasers and to an active alignment of the two
beams, the frequency accuracy is well below 100 kHz. Over the vertical axis the
spectrometer benefits from shot-noise limited detection, signal enhancement via
multipass cell, active flattening of the spectral baseline and measurement
times of few seconds over spectral spans larger than 10 GHz. Under these
conditions an efficient averaging of Raman spectra is possible over long
measurement times with minimal distortion of spectral lineshapes. By changing
the pump laser, transitions can be covered in a very broad frequency span, from
50 to 5000 , including both vibrational and rotational bands.
The spectrometer has been developed for studies of fundamental and collisional
physics of hydrogen isotopologues and has been recently applied to the
metrology of the Q(1) 1-0 line of
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