High intrinsic energy resolution photon number resolving detectors

Transition Edge Sensors (TESs) are characterized by the intrinsic figure of merit to resolve both the energy and the statistical distribution of the incident photons. These properties lead TES devices to become the best single photon detector for quantum technology experiments. For a TES based on titanium and gold has been reached, at telecommunication wavelength, an unprecedented intrinsic energy resolution (0.113 eV). The uncertainties analysis of both energy resolution and photon state assignment has been discussed. The thermal properties of the superconductive device have been studied by fitting the bias curve to evaluate theoretical limit of the energy resolution

Rasch validation of the prosthetic mobility questionnaire: a new outcome measure for assessing mobility in people with lower limb amputation

Objective: To create a new outcome measure of mobility in people with lower limb amputation, based on a pool of 14 items assessing prosthetic mobility, comprising the 12-item Prosthesis Evaluation Questionnaire (Mobility Section) plus 2 new items. Design: Cross-sectional study. Subjects: A total of 100 subjects (median age 58 years; 46 males; median body mass index 23.8) who had recently undergone lower limb amputation. Methods: Each patient completed the 14-item questionnaire twice: (i) at admission to the rehabilitation unit for prosthetic rehabilitation training; (ii) at 6-month follow-up after discharge. Results: After Rasch analysis, 2 items were deleted (one due to misfit, the other because showing large (> 0.30) positive correlation of residuals with two other items (local dependence). The remaining items fitted the Rasch model (internal construct validity), giving a new 12-item scale with a 5-level response format, the Prosthetic Mobility Questionnaire (PMQ), which demonstrated unidimensionality, lack of differential item functioning, and good reliability indices (person-separation reliability = 0.87; Cronbach's alpha 0.88). Conclusion: Although further studies are needed to increase confidence in clinical use of the PMQ, this new questionnaire appears to be a promising, psychometrically-sound patientreported outcome measure for assessment of mobility in subjects with lower limb amputation who use a prosthesi

Single-photon light detection with transition-edge sensors

Transition-Edge Sensors (TESs) are microcalorimeters that measure the energy of incident single photons by the resistance increase of a superconducting film biased within the superconducting-to-normal transition. TES are able to detect single photons from IR to X-ray with an intrinsic energy resolution and photon-number discrimination capability. Metrology, astronomy and quantum communication are the fields where these properties can be particularly useful. In this work, we report about characterization of different TESs based on Ti films. Single photons have been detected from 200nm to 800 nm working at transition temperature Tc ∼ 100 mK. Using a pulsed laser at 690nm we have demonstrated the capability to resolve up to five photons

Self-reported knee symptoms assessed by KOOS questionnaire in downhill runners (skyrunners)

Background: The knee is the weight-bearing joint most commonly associated with sports injuries, and therefore is most at risk of developing degenerative changes, including osteoarthritis. Skyrunners can be considered to be at risk of developing symptoms of post-traumatic osteoarthritis due to downhill running. Aim: The aim of this study was to analyze the health of the knee joints of a large group of these athletes via a specific self-report questionnaire. Methods: This study was carried out by asking the participants of seven official Skyraces (22.4±3.1 km length; 1596±393 m elevation) to fill out a questionnaire. Information regarding age, sex, downhill elevation (m) during training and competitions over the last month, and history of previous knee injury was also collected before the participants filled out the Knee injury and Osteoarthritis Outcome Score (KOOS), which is a reliable and validated instrument designed to assess patients' opinions about their knees and associated problems that can result in post-traumatic osteoarthritis. Athletes were divided into six age groups (from 17 to 70 years) and 12 groups based on the downhill gradient they had covered over the last month (from 1,000 to 40,000 m). Results: Six hundred twenty-one questionnaires were collected from 45% of the participants in the seven races. Multivariate analysis revealed that self-reported KOOS scores were unrelated to age, sex and monthly downhill gradient. Only 74 (12%) of the participants reported previous knee injuries. Significant differences in the five subscales of the KOOS were found between skyrunners with and without previous knee injuries (P<0.01). Conclusions: In the studied population, regular training for downhill running and participation in Skyraces could not be considered risk factors for subjective knee symptoms. Skyrunners with selfreported histories of knee injuries scored worse on all five subscales of the KOO

Self consistent, absolute calibration technique for photon number resolving detectors

Well characterized photon number resolving detectors are a requirement for many applications ranging from quantum information and quantum metrology to the foundations of quantum mechanics. This prompts the necessity for reliable calibration techniques at the single photon level. In this paper we propose an innovative absolute calibration technique for photon number resolving detectors, using a pulsed heralded photon source based on parametric down conversion. The technique, being absolute, does not require reference standards and is independent upon the performances of the heralding detector. The method provides the results of quantum efficiency for the heralded detector as a function of detected photon numbers. Furthermore, we prove its validity by performing the calibration of a Transition Edge Sensor based detector, a real photon number resolving detector that has recently demonstrated its effectiveness in various quantum information protocols.Comment: 9 pages, 2 figure

Towards joint reconstruction of noise and losses in quantum channels

The calibration of a quantum channel, i.e. the determination of the transmission losses affecting it, is definitely one of the principal objectives in both the quantum communication and quantum metrology frameworks. Another task of the utmost relevance is the identification, e.g. by extracting its photon number distribution, of the noise potentially present in the channel. Here we present a protocol, based on the response of a photon-number-resolving detector at different quantum efficiencies, able to accomplish both of these tasks at once, providing with a single measurement an estimate of the transmission losses as well as the photon statistics of the noise present in the exploited quantum channel. We show and discuss the experimental results obtained in the practical implementation of such protocol, with different kinds and levels of noise.Comment: 6 pages, 4 figure

Pediatric oncological spondylolisthesis: the contribution of Physical Medicine and Rehabilitation and Orthodontics. A narrative review

Different forms of spondylolisthesis (SP) have been described. This pathological condition is often due to a birth defect in the lumbar area, but it can also be caused by a sudden injury resulting from an acute trauma. In athletic children and adolescents, SP may represent a stress fracture triggered by overuse. SP can also be consequent to cancer, although this clinical condition is rare. The first manifestation of SP is pain. Neoplasm related SP may also induce physical impairment and postural alterations of the spine, such as flatback and hyperkyphosis. These changes may also affect the entire spine, including the cervical region (i.e., forward neck) and the head (i.e., forward head). A prompt assessment of children with oncological SP is crucial and involves clinical and radiological evaluations. Multiple healthcare professionals are involved in the management of children with oncological SP, including spinal specialists, pediatricians, oncologists, and psychologists. Orthodontists may also contribute to cervical posture evaluation. The authors of this review aim to provide a comprehensive overview of the topic, particularly focusing on the clinical assessment of children with oncological SP and the possibilities for rehabilitative treatment