Fast and simple characterization of a photon pair source

We present an exact model of the detection statistics of a probabilistic source of photon pairs from which a fast, simple and precise method to measure the source's brightness and photon channel transmissions is demonstrated. We measure such properties for a source based on spontaneous parametric downconversion in a periodically poled LiNbO$_3$ crystal producing pairs at 810 and 1550 nm wavelengths. We further validate the model by comparing the predicted and measured values for the $g^{(2)}(0)$ of a heralded single photon source over a wide range of the brightness. Our model is of particular use for monitoring and tuning the brightness on demand as required for various quantum communication applications. We comment on its applicability to sources involving spectral and/or spatial filtering.Comment: 10 pages, 5 figures. Published versio

Field Induced Nodal Order Parameter in the Tunneling Spectrum of YBa2_2Cu3_3O7−x_{7-x} Superconductor

We report planar tunneling measurements on thin films of YBa$_2$Cu$_3$O$_{7-x}$ at various doping levels under magnetic fields. By choosing a special setup configuration, we have probed a field induced energy scale that dominates in the vicinity of a node of the d-wave superconducting order parameter. We found a high doping sensitivity for this energy scale. At Optimum doping this energy scale is in agreement with an induced $id_{xy}$ order parameter. We found that it can be followed down to low fields at optimum doping, but not away from it.Comment: 9 pages, 8 figures, accepted for publication in Phys. Rev.

Static and dynamic responses to hyperoxia of normal placenta across gestation with T2*-weighted sequences

OBJECTIVES: T2*-weighted sequences have been identified as non-invasive tools to study the placental oxygenation in-vivo. This study aims to investigate both static and dynamic responses to hyperoxia of the normal placenta across gestation.METHODS: We conducted a single-center prospective study including 52 uncomplicated pregnancies. Two T2*-weighted sequences were performed: T2*-relaxometry was performed before and after maternal hyperoxia. The histogram distribution of T2* values was assessed by fitting a gamma distribution as T2*~Γ(αβ). A dynamic acquisition (BOLD protocol) was also performed before and during oxygen supply, until placental oxygen saturation. The signal change over time was modeled using a sigmoid function, used to determine the intensity of enhancement (∆BOLD,%), a temporal variation coefficient (λ,min -1 , controlling the slope of the curve), and the maximal steepness (Vmax, ∆BOLD.min -1 ) of placental enhancement. RESULTS: The histogram analysis of the T2* values in normoxia showed a whole-placenta variation, with a decreasing linear trend in the mean T2* value (R= -0.83, 95% CI [-0.9, -0.71], p&lt;0.001) along with a more peaked and narrower distribution of T2* values across gestation. After maternal hyperoxia, the mean T2* ratios (mean T2* hyperoxia / mean T2* baseline ) were positively correlated with gestational age, while the other histogram parameters remained stable, suggesting a translation of the histogram towards higher values with a similar aspect. The ∆BOLD showed a non-linear increase across gestation. Conversely, the λ(min -1 ) parameter, showed an inverted trend across gestation, with a significantly weaker correlation (R = -0.33, 95% CI [-0.58, -0.02], p=0.04, R 2 = 0.1). As a combination of ∆BOLD and λ, the changes in Vmax throughout gestation were mainly influenced by the changes in ∆BOLD and resulted in a positive non-linear correlation with gestational age. CONCLUSION: Our results suggest that the decrease in the T2* placental signal over gestation does not reflect a dysfunction. The BOLD effect, representative of a free-diffusion model of oxygenation, highlights the growing differences in oxygen saturation between mother and fetus across gestation (∆BOLD), and placental permeability to oxygen (λ). This article is protected by copyright. All rights reserved.</p

Highly multimode memory in a crystal

We experimentally demonstrate the storage of 1060 temporal modes onto a thulium-doped crystal using an atomic frequency comb (AFC). The comb covers 0.93 GHz defining the storage bandwidth. As compared to previous AFC preparation methods (pulse sequences i.e. amplitude modulation), we only use frequency modulation to produce the desired optical pumping spectrum. To ensure an accurate spectrally selective optical pumping, the frequency modulated laser is self-locked on the atomic comb. Our approach is general and should be applicable to a wide range of rare-earth doped material in the context of multimode quantum memory

Pharmacokinetics of intramuscular maropitant in pigs (Sus scrofa domesticus)

Pigs are at risk of vomiting from medical conditions as well as the emetic side effects of drugs administered for peri-operative manipulations, but there is a lack of pharmacokinetic data for potential anti-emetic therapies, such as maropitant, in this species. The main objective of this study was to estimate plasma pharmacokinetic parameters for maropitant in pigs after a single intramuscular (IM) administration dosed at 1.0 mg/ kg. A secondary objective was to estimate pilot pharmacokinetic parameters in pigs after oral (PO) administration at 2.0 mg/kg. Maropitant was administered to six commercial pigs at a dose of 1.0 mg/kg IM. Plasma samples were collected over 72 h. After a 7-day washout period, two pigs were administered maropitant at a dose of 2.0 mg/ kg PO. Maropitant concentrations were measured via liquid chromatography/mass spectrometry (LC–MS/ MS). A non-compartmental analysis was used to derive pharmacokinetics parameters. No adverse events were noted in any of the study pigs after administration. Following single IM administration, maximum plasma concentration was estimated at 412.7 ± 132.0 ng/mL and time to maximum concentration ranged from 0.083 to 1.0 h. Elimination half-life was estimated at 6.7 ± 1.28 h, and mean residence time was 6.1 ± 1.2 h. Volume of distribution after IM administration was 15.9 L/ kg. Area under the curve was 1336 ± 132.0 h*ng/mL. The relative bioavailability of PO administration was noted to be 15.5% and 27.2% in the two pilot pigs. The maximum systemic concentration observed in the study pigs after IM administration was higher than what was observed after subcutaneous administration in dogs, cats, or rabbits. The achieved maximum concentration exceeded the concentrations for anti-emetic purposes in dogs and cats; however, a specific anti-emetic concentration is currently not known for pigs. Further research is needed into the pharmacodynam

EquiFACS: the Equine Facial Action Coding System

Although previous studies of horses have investigated their facial expressions in specific contexts, e.g. pain, until now there has been no methodology available that documents all the possible facial movements of the horse and provides a way to record all potential facial configurations. This is essential for an objective description of horse facial expressions across a range of contexts that reflect different emotional states. Facial Action Coding Systems (FACS) provide a systematic methodology of identifying and coding facial expressions on the basis of underlying facial musculature and muscle movement. FACS are anatomically based and document all possible facial movements rather than a configuration of movements associated with a particular situation. Consequently, FACS can be applied as a tool for a wide range of research questions. We developed FACS for the domestic horse (Equus caballus) through anatomical investigation of the underlying musculature and subsequent analysis of naturally occurring behaviour captured on high quality video. Discrete facial movements were identified and described in terms of the underlying muscle contractions, in correspondence with previous FACS systems. The reliability of others to be able to learn this system (EquiFACS) and consistently code behavioural sequences was high—and this included people with no previous experience of horses. A wide range of facial movements were identified, including many that are also seen in primates and other domestic animals (dogs and cats). EquiFACS provides a method that can now be used to document the facial movements associated with different social contexts and thus to address questions relevant to understanding social cognition and comparative psychology, as well as informing current veterinary and animal welfare practices

Promoting the use of a self-management strategy among novice chiropractors treating individuals with spine pain: A mixed methods pilot clustered-clinical trial

Background The uptake of Self-Management Support (SMS) among clinicians is suboptimal. To date, few studies have tested knowledge translation (KT) interventions to increase the application of SMS in chiropractic teaching clinics. Study objective Evaluate the feasibility of implementing a KT intervention to promote the use of a SMS strategy among chiropractic interns, their supervisors, and individuals with spine pain compared to controls. Methods Mixed methods pilot clustered-clinical trial. Clusters of 16 Patient Management Teams were allocated to a complex KT intervention (online and workshop training). Primary feasibility outcomes for clinicians, interns and patients were rates of recruitment, retention, and adherence to protocol. A nominal group technique and interviews were used to seek end-users' views on the implementation process, and generate possible solutions. Results In total, 16 (84%) clinicians, 65 (26%) interns and 42 patients agreed to participate. All clinicians in the intervention group completed all KT intervention components, 23 interns (85%) completed the online training and 14 interns (51.8%) attended the workshop training. All clinicians in the intervention and seven (78%) in the control group completed all outcome measures at baseline and 6-month follow-up, while 15 (55.6%) and 23 (60.5%) interns in the intervention and control groups completed the questionnaires at baseline and 6-month follow-up, respectively. Among patients, 10 (52.6%) and 12 (52.2%) in the intervention and control groups respectively completed the questionnaires at the end of the study. Based on interview findings, solutions to improve the feasibility of conducting a full trial include: making SMS a part of the internship, changing the time of introducing the study to the interns, and having more training on SMS. Conclusion Recruitment and retention of chiropractic interns and patients for a larger implementation trial in a single outpatient teaching clinic may be challenging. © 2022 Eilayyan et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited