Quantum State Reconstruction in Quantum Optomechanics

The ability to perform mechanical states reconstruction is an essential task in quantum optomechanics to understand different quantum aspects of mechanical states of motion. Many interesting phenomena appear when the light and mechanical motion are coupled through the radiationpressure coupling. Preparing, controlling, and measuring mechanical states are all very crucial in the study and development of quantum optomechanics. In this dissertation, we introduce a practical scheme for mechanical states reconstruction in the weak optomechancial coupling regime in which most optomechanical systems operates. The scheme relies on sending a beam of two-level atoms to pass through an optomechanical cavity where an oscillating mirror is coupled to a cavity field. The atoms interact resonantly with the cavity field as they pass through the cavity. As the oscillating mirror modifies the dynamics of the atoms, we show in this dissertation that by measuring the atomic population inversion of the atoms when they exit the optomechanical cavity, it is possible to obtain the mirror’s state by analyzing the measured data of the population inversion. In the first part of this dissertation, we study a hybrid system in which a two-level atom is placed inside a cavity field where one side of the cavity is free to move. The two-level atom is coupled to the cavity field through the well known Jaynes-Cummings coupling, whereas the mechanical mirror and the cavity field are coupled to each other via the radiation-pressure coupling. A complete analytical and numerical study is performed on this system, and it is shown that the mechanical mirror modifies the atomic population inversion in such a way that each mechanical state changes the signal of the population inversion of the atom differently. From the results in this part of the dissertation, we concluded that the population inversion can be analyzed and employed to extract the quantum state of the mechanical mirror. Second, as each specific mechanical state affects the atomic population inversion differently, we developed the idea of using the atom as a tool to reconstruct the quantum state of the mechanical mirror. We first assumed that the two-level atom is initially in a superposition of its excited and ground states while both the cavity field and the mechanical mirror are in general superposiii tion of Fock states with unknown coefficients. The derived general expression of the population inversion indicates that it is sufficient to initially prepare the atoms in the excited states before passing through the optomechancial cavity and the cavity field is in vacuum state. The population inversion of the atoms exiting the cavity can then be measured, and the collected data can be used to determine the full state of the mechanical mirror. The scheme in this part of the dissertation is only developed for measuring pure mechanical states. Third, we extended the scheme of mechanical states reconstruction to the more practical states of the mirror in which the mirror is initially in a mixed state. We derived a general analytical solution of the population inversion allowing us to reconstruct more experimentally feasible states of the mechanical mirror such as thermal states

Climate Process Team on internal wave–driven ocean mixing

Author Posting. © American Meteorological Society, 2017. This article is posted here by permission of American Meteorological Society for personal use, not for redistribution. The definitive version was published in Bulletin of the American Meteorological Society 98 (2017): 2429-2454, doi:10.1175/BAMS-D-16-0030.1.Diapycnal mixing plays a primary role in the thermodynamic balance of the ocean and, consequently, in oceanic heat and carbon uptake and storage. Though observed mixing rates are on average consistent with values required by inverse models, recent attention has focused on the dramatic spatial variability, spanning several orders of magnitude, of mixing rates in both the upper and deep ocean. Away from ocean boundaries, the spatiotemporal patterns of mixing are largely driven by the geography of generation, propagation, and dissipation of internal waves, which supply much of the power for turbulent mixing. Over the last 5 years and under the auspices of U.S. Climate Variability and Predictability Program (CLIVAR), a National Science Foundation (NSF)- and National Oceanic and Atmospheric Administration (NOAA)-supported Climate Process Team has been engaged in developing, implementing, and testing dynamics-based parameterizations for internal wave–driven turbulent mixing in global ocean models. The work has primarily focused on turbulence 1) near sites of internal tide generation, 2) in the upper ocean related to wind-generated near inertial motions, 3) due to internal lee waves generated by low-frequency mesoscale flows over topography, and 4) at ocean margins. Here, we review recent progress, describe the tools developed, and discuss future directions.We are grateful to U.S. CLIVAR for their leadership in instigating and facilitating the Climate Process Team program. We are indebted to NSF and NOAA for sponsoring the CPT series.2018-06-0

Climate Process Team on Internal-Wave Driven Ocean Mixing

Diapycnal mixing plays a primary role in the thermodynamic balance of the ocean, and consequently, in oceanic heat and carbon uptake and storage. Though observed mixing rates are on average consistent with values required by inverse models, recent attention has focused on the dramatic spatial variability, spanning several orders of magnitude, of mixing rates in both the upper and deep ocean. Climate models have been shown to be very sensitive not only to the overall level but to the detailed distribution of mixing; sub-grid-scale parameterizations based on accurate physical processes will allow model forecasts to evolve with a changing climate. Spatio-temporal patterns of mixing are largely driven by the geography of generation, propagation and destruction of internal waves, which are thought to supply much of the power for turbulent mixing. Over the last five years and under the auspices of US CLIVAR, a NSF and NOAA supported Climate Process Team has been engaged in developing, implementing and testing dynamics-base parameterizations for internal-wave driven turbulent mixing in global ocean models. The work has primarily focused on turbulence 1) near sites of internal tide generation, 2) in the upper ocean related to wind-generated near inertial motions, 3) due to internal lee waves generated by low-frequency mesoscale flows over topography, and 4) at ocean margins. Here we review recent progress, describe the tools developed, and discuss future directions

COVID-19 Outcomes in Saudi Arabia and the UK: A Tale of Two Kingdoms

Background: While the number of COVID-19 cases and deaths around the world is starting to peak, it is essential to point out how different countries manage the outbreak and how different measures and experience resulted in different outcomes. This study aimed to compare the effect of the measures taken by Saudi Arabia and the United Kingdom (UK) governments on the outcome of the COVID-19 pandemic as predicted by a mathematical model. // Method: Data on the numbers of cases, deaths and government measures were collected from Saudi’s Ministry of Health and Public Health England. A prediction of the trend of cases, deaths and days to peak was then modelled using the mathematical technique, Exponential Logistic Growth and Susceptible Infectious Recovered (SIR) model. The measures taken by the governments and the predicted outcomes were compared to assess effectiveness. // Result: We found over three months that 22 fast and extreme measures had been taken in Saudi Arabia compared to eight slow and late measures in the UK. This resulted in a decline in numbers of current infected cases per day and mortality in Saudi Arabia compared to the UK. Based on the SIR model, the predicted number of COVID-19 cases in Saudi as of 31st of March was 2,064, while the predicted number of cases was 63012 in the UK. In addition, the pandemic is predicted to peak earlier on the 27th of March in Saudi Arabia compared to the 2nd of May 2020 in the UK. The end of transition phases for Saudi and UK according to the model, were predicted to be on 18th of April and 24th of May, respectively. These numbers relate to early and decisive measures adopted by the Saudi government. // Conclusion: We show that early extreme measures, informed by science and guided by experience, helped reduce the spread and related deaths from COVID-19 in Saudi. Actions were taken by Saudi under the national slogan “We are all responsible” resulted in the observed reduced number of current and predicted cases and deaths compared to the UK approach “keep calm and carry on”

Investigation of the cardiac depressant effect of Caralluma tuberculate N.E.Br on isolated rabbit heart

Purpose: To investigate the histopathological and cardiac depressant effect of the aqueous methanol extract of Caralluma tuberculata N.E. Br (AMECT) (family: Asclepiadaceae)’ and to determine if there is a scientific basis for its cardiovascular diseases-related folkloric use. Methods: The effect of AMECT in different concentrations ranging from 0.00001 to 1.0 mg/mL were evaluated in isolated perfused rabbit heart to assess their effect on the force of contraction and heart rate using Langendorff’s apparatus. Atropine and adrenaline were used to identify the underlying mechanism of response produced by AMECT. The extract was studied for its possible mechanism in the absence and presence of atropine and adrenaline. In addition, sub-chronic toxicity and histopathological study of heart tissues in rats were assessed by administering 500 mg/kg of extract. Results: At all concentrations, AMECT produced significant (p < 0.001) negative ionotropic and negative chronotropic effects. The most significant effect was observed at 0.001 mg/mL and higher concentrations hence 0.001 mg/mL was selected for further studies. Pre-incubation with atropine did not significantly inhibit the effects of AMECT. However, AMECT significantly (p < 0.01) blocked the cardiac stimulant effect of adrenaline. In the histopathological studies, AMECT did not produce any significant cellular changes or signs of toxicity in the sub-chronic toxicity study. Conclusion: The cardiac-depressant responses of AMECT may involve the β-adrenergic receptors in the myocardium of isolated rabbit heart thus confirming the rationale for its use in ethnomedicine for cardiac diseases

Prescription patterns for children with juvenile idiopathic arthritis in Michigan Medicaid: a comparison by prescriber type

BACKGROUND: Due to a limited number and disparate distribution of pediatric rheumatologists in the US, a variety of physician types provide care to children with rheumatologic diseases. However, little is known about how that care may differ across prescribing physician groups. Our objective was to compare medication claims for children with juvenile idiopathic arthritis (JIA) by type of prescribing physician. METHODS: We performed a retrospective cohort study of children with JIA using Michigan Medicaid data for 7/1/2005-6/30/2007, employing descriptive and bivariate analyses by age, medication type, and prescriber type. RESULTS: Among 397 children, there was no difference in the frequency of medication claims for children with internist versus pediatric rheumatologist prescribers. Children with non-rheumatologist prescribers were less likely to have claims for disease modifying anti-rheumatic drugs (DMARDs) and biologic agents. CONCLUSION: Differential use of DMARDs and biologic agents by rheumatologists indicates the importance of referring children with JIA for specialty care

Clinical approach to the diagnosis of autoimmune encephalitis in the pediatric patient

Autoimmune encephalitis (AE) is an important and treatable cause of acute encephalitis. Diagnosis of AE in a developing child is challenging because of overlap in clinical presentations with other diseases and complexity of normal behavior changes. Existing diagnostic criteria for adult AE require modification to be applied to children, who differ from adults in their clinical presentations, paraclinical findings, autoantibody profiles, treatment response, and long-term outcomes.A subcommittee of the Autoimmune Encephalitis International Working Group collaborated through conference calls and email correspondence to consider the pediatric-specific approach to AE. The subcommittee reviewed the literature of relevant AE studies and sought additional input from other expert clinicians and researchers.Existing consensus criteria for adult AE were refined for use in children. Provisional pediatric AE classification criteria and an algorithm to facilitate early diagnosis are proposed. There is also discussion about how to distinguish pediatric AE from conditions within the differential diagnosis.Diagnosing AE is based on the combination of a clinical history consistent with pediatric AE and supportive diagnostic testing, which includes but is not dependent on antibody testing. The proposed criteria and algorithm require validation in prospective pediatric cohorts.Copyright © 2020 The Author(s). Published by Wolters Kluwer Health, Inc. on behalf of the American Academy of Neurology

International Consensus Recommendations for the Treatment of Pediatric NMDAR Antibody Encephalitis.

OBJECTIVE: To create an international consensus treatment recommendation for pediatric NMDA receptor antibody encephalitis (NMDARE). METHODS: After selection of a panel of 27 experts with representation from all continents, a 2-step Delphi method was adopted to develop consensus on relevant treatment regimens and statements, along with key definitions in pediatric NMDARE (disease severity, failure to improve, and relapse). Finally, an online face-to-face meeting was held to reach consensus (defined as ≥75% agreement). RESULTS: Corticosteroids are recommended in all children with NMDARE (pulsed IV preferred), with additional IV immunoglobulin or plasma exchange in severe patients. Prolonged first-line immunotherapy can be offered for up to 3-12 months (oral corticosteroids or monthly IV corticosteroids/immunoglobulin), dependent on disease severity. Second-line treatments are recommended for cases refractory to first-line therapies (rituximab preferred over cyclophosphamide) and should be considered about 2 weeks after first-line initiation. Further immunotherapies for refractory disease 1-3 months after second-line initiation include another second-line treatment (such as cyclophosphamide) and escalation to tocilizumab. Maintenance immune suppression beyond 6 months (such as rituximab redosing or mycophenolate mofetil) is generally not required, except for patients with a more severe course or prolonged impairments and hospitalization. For patients with relapsing disease, second-line and prolonged maintenance therapy should be considered. The treatment of NMDARE following herpes simplex encephalitis should be similar to idiopathic NMDARE. Broad guidance is provided for the total treatment duration (first line, second line, and maintenance), which is dictated by the severity and clinical course (i.e., median 3, 9 and 18 months in the best, average, and worst responders, respectively). Recommendations on the timing of oncologic searches are provided. CONCLUSION: These international consensus recommendations for the management of pediatric NMDARE aim to standardize the treatment and provide practical guidance for clinicians, rather than absolute rules. A similar recommendation could be applicable to adult patients

Climate Process Team On Internal Wave-Driven Ocean Mixing

The study summarizes recent advances in our understanding of internal wave–driven turbulent mixing in the ocean interior and introduces new parameterizations for global climate ocean models and their climate impacts