Quantum interference of electromechanically stabilized emitters in nanophotonic devices

Photon-mediated coupling between distant matter qubits may enable secure communication over long distances, the implementation of distributed quantum computing schemes, and the exploration of new regimes of many-body quantum dynamics. Nanophotonic devices coupled to solid-state quantum emitters represent a promising approach towards realization of these goals, as they combine strong light-matter interaction and high photon collection efficiencies. However, the scalability of these approaches is limited by the frequency mismatch between solid-state emitters and the instability of their optical transitions. Here we present a nano-electromechanical platform for stabilization and tuning of optical transitions of silicon-vacancy (SiV) color centers in diamond nanophotonic devices by dynamically controlling their strain environments. This strain-based tuning scheme has sufficient range and bandwidth to alleviate the spectral mismatch between individual SiV centers. Using strain, we ensure overlap between color center optical transitions and observe an entangled superradiant state by measuring correlations of photons collected from the diamond waveguide. This platform for tuning spectrally stable color centers in nanophotonic waveguides and resonators constitutes an important step towards a scalable quantum network

Chitayat-Hall and Schaaf-Yang syndromes: a common aetiology: expanding the phenotype of MAGEL2-related disorders

Chitayat-Hall syndrome, initially described in 1990, is a rare condition characterised by distal arthrogryposis, intellectual disability, dysmorphic features and hypopituitarism, in particular growth hormone deficiency. The genetic aetiology has not been identified.Background Chitayat-Hall syndrome, initially described in 1990, is a rare condition characterised by distal arthrogryposis, intellectual disability, dysmorphic features and hypopituitarism, in particular growth hormone deficiency. The genetic aetiology has not been identified. Methods and results We identified three unrelated families with a total of six affected patients with the clinical manifestations of Chitayat-Hall syndrome. Through whole exome or whole genome sequencing, pathogenic variants in the MAGEL2 gene were identified in all affected patients. All disease-causing sequence variants detected are predicted to result in a truncated protein, including one complex variant that comprised a deletion and inversion. Conclusions Chitayat-Hall syndrome is caused by pathogenic variants in MAGEL2 and shares a common aetiology with the recently described Schaaf-Yang syndrome. The phenotype of MAGEL2-related disorders is expanded to include growth hormone deficiency as an important and treatable complicationhe McLaughlin Centre, University of Toronto, Toronto, Canada, and Fondation Jeanne et Jean- Louis Lévesque (JLM). The Centre for Genetic Medicine, The Hospital for Sick Children, Toronto, Canada. FDL has a fellowship funded by FCT - Fundação para a Ciência e a Tecnologia (SFRH/BD/84650/2010)info:eu-repo/semantics/publishedVersio

Comparison of Robotics, Functional Electrical Stimulation, and Motor Learning Methods for Treatment of Persistent Upper Extremity Dysfunction After Stroke: A Randomized Controlled Trial

Objective To compare response to upper-limb treatment using robotics plus motor learning (ML) versus functional electrical stimulation (FES) plus ML versus ML alone, according to a measure of complex functional everyday tasks for chronic, severely impaired stroke survivors. Design Single-blind, randomized trial. Setting Medical center. Participants Enrolled subjects (N=39) were \u3e1 year post single stroke (attrition rate=10%; 35 completed the study). Interventions All groups received treatment 5d/wk for 5h/d (60 sessions), with unique treatment as follows: ML alone (n=11) (5h/d partial- and whole-task practice of complex functional tasks), robotics plus ML (n=12) (3.5h/d of ML and 1.5h/d of shoulder/elbow robotics), and FES plus ML (n=12) (3.5h/d of ML and 1.5h/d of FES wrist/hand coordination training). Main Outcome Measures Primary measure: Arm Motor Ability Test (AMAT), with 13 complex functional tasks; secondary measure: upper-limb Fugl-Meyer coordination scale (FM). Results There was no significant difference found in treatment response across groups (AMAT: P≥.584; FM coordination: P≥.590). All 3 treatment groups demonstrated clinically and statistically significant improvement in response to treatment (AMAT and FM coordination: P≤.009). A group treatment paradigm of 1:3 (therapist/patient) ratio proved feasible for provision of the intensive treatment. No adverse effects. Conclusions Severely impaired stroke survivors with persistent (\u3e1y) upper-extremity dysfunction can make clinically and statistically significant gains in coordination and functional task performance in response to robotics plus ML, FES plus ML, and ML alone in an intensive and long-duration intervention; no group differences were found. Additional studies are warranted to determine the effectiveness of these methods in the clinical setting

A Specific and Rapid Neural Signature for Parental Instinct

Darwin originally pointed out that there is something about infants which prompts adults to respond to and care for them, in order to increase individual fitness, i.e. reproductive success, via increased survivorship of one's own offspring. Lorenz proposed that it is the specific structure of the infant face that serves to elicit these parental responses, but the biological basis for this remains elusive. Here, we investigated whether adults show specific brain responses to unfamiliar infant faces compared to adult faces, where the infant and adult faces had been carefully matched across the two groups for emotional valence and arousal, as well as size and luminosity. The faces also matched closely in terms of attractiveness. Using magnetoencephalography (MEG) in adults, we found that highly specific brain activity occurred within a seventh of a second in response to unfamiliar infant faces but not to adult faces. This activity occurred in the medial orbitofrontal cortex (mOFC), an area implicated in reward behaviour, suggesting for the first time a neural basis for this vital evolutionary process. We found a peak in activity first in mOFC and then in the right fusiform face area (FFA). In mOFC the first significant peak (p<0.001) in differences in power between infant and adult faces was found at around 130 ms in the 10–15 Hz band. These early differences were not found in the FFA. In contrast, differences in power were found later, at around 165 ms, in a different band (20–25 Hz) in the right FFA, suggesting a feedback effect from mOFC. These findings provide evidence in humans of a potential brain basis for the “innate releasing mechanisms” described by Lorenz for affection and nurturing of young infants. This has potentially important clinical applications in relation to postnatal depression, and could provide opportunities for early identification of families at risk

Mining a Cathepsin Inhibitor Library for New Antiparasitic Drug Leads

The targeting of parasite cysteine proteases with small molecules is emerging as a possible approach to treat tropical parasitic diseases such as sleeping sickness, Chagas' disease, and malaria. The homology of parasite cysteine proteases to the human cathepsins suggests that inhibitors originally developed for the latter may be a source of promising lead compounds for the former. We describe here the screening of a unique ∼2,100-member cathepsin inhibitor library against five parasite cysteine proteases thought to be relevant in tropical parasitic diseases. Compounds active against parasite enzymes were subsequently screened against cultured Plasmodium falciparum, Trypanosoma brucei brucei and/or Trypanosoma cruzi parasites and evaluated for cytotoxicity to mammalian cells. The end products of this effort include the identification of sub-micromolar cell-active leads as well as the elucidation of structure-activity trends that can guide further optimization efforts