Nonadiabatic control of a superconducting qubit via strong driving

Thesis (S.B.)--Massachusetts Institute of Technology, Dept. of Physics, 2008.Includes bibliographical references (leaf 43).Quantum computation offers the promise of speeding up many calculations that are intractable on classical computers, including but not limited to factoring and the simulation of quantum mechanical systems. Quantum computation is achieved by replacing the bits of a classical computer with quoits. Qubits generalize bits by allowing not only the classical states of zero and one, but also any arbitrary superposition of zero and one. These qubits are implemented as two-state systems by mapping the classical one and zero states to two orthogonal quantum states. The qubits are then manipulated by varying the Hamiltonian of the two-state systems with time. The standard method to manipulate a two-state system is to drive it weakly using Rabi dynamics. This approach is ineffective for a large scale quantum computer because the rotation is slow, and decoherence breaks the fragile state before the computation can be completed. To address this problem, we developed a method to rapidly rotate a qubit by an arbitrary angle. This is achieved by abandoning Rabi oscillations, and instead using a strong, rapidly changing field to coherently rotate the spin. We rapid drive the system through an avoided crossing and back again by giving the on diagonal term of the Hamiltonian a parabolic time dependence. In this paper, I contrast the standard method of spin rotation via Rabi oscillations with our protocol. Then, I discuss the various numerical simulations used to evaluate our protocol. Finally, I present some experimental evidence suggesting the protocol will be effective when implemented. Then, I discuss experimental findings and computational results of our method. We found regions of parameter space that allow a qubit to be rapidly rotated by any angle from zero to nearly ~r. This new protocol for arbitrary qubit rotation is a significant improvement over techniques relying on Rabi oscillations, reducing the time needed to transition qubits.(cont.) Our protocol deserves further study and refinement for its potential to speed up and, thusly, reduce the problem of decoherence in quantum computation.by Matthew W. Farrell.S.B

Cholesterol-lowering drugs cause dissolution of cholesterol crystals and disperse Kupffer cell crown-like structures during resolution of NASH

Cholesterol crystals form within hepatocyte lipid droplets in human and experimental nonalcoholic steatohepatitis (NASH) and are the focus of crown-like structures (CLSs) of activated Kupffer cells (KCs). Obese, diabetic Alms1 mutant ( foz/foz ) mice were a fed high-fat (23%) diet containing 0.2% cholesterol for 16 weeks and then assigned to four intervention groups for 8 weeks: a ) vehicle control, b ) ezetimibe (5 mg/kg/day), c ) atorvastatin (20 mg/kg/day), or d ) ezetimibe and atorvastatin. Livers of vehicle-treated mice developed fibrosing NASH with abundant cholesterol crystallization within lipid droplets calculated to extend over 3.3% (SD, 2.2%) of liver surface area. Hepatocyte lipid droplets with prominent cholesterol crystallization were surrounded by TNFα -positive (activated) KCs forming CLSs ( ≥ 3 per high-power field). KCs that formed CLSs stained positive for NLRP3, implicating activation of the NLRP3 inflammasome in response to cholesterol crystals. In contrast, foz/foz mice treated with ezetimibe and atorvastatin showed near-complete resolution of cholesterol crystals [0.01% (SD, 0.02%) of surface area] and CLSs (0 per high-power field), with amelioration of fibrotic NASH. Ezetimibe or atorvastatin alone had intermediate effects on cholesterol crystallization, CLSs, and NASH. These findings are consistent with a causative link between exposure of hepatocytes and KCs to cholesterol crystals and with the development of NASH possibly mediated by NLRP3 activation

A deep ocean acoustic noise floor, 1–800 Hz

Author Posting. © Acoustical Society of America, 2018. This article is posted here by permission of Acoustical Society of America for personal use, not for redistribution. The definitive version was published in Journal of the Acoustical Society of America 143 (2018): 1223, doi:10.1121/1.5025042.The ocean acoustic noise floor (observed when the overhead wind is low, ships are distant, and marine life silent) has been measured on an array extending up 987 m from 5048 m depth in the eastern North Pacific, in what is one of only a few recent measurements of the vertical noise distribution near the seafloor in the deep ocean. The floor is roughly independent of depth for 1–6 Hz, and the slope (∼ f−7) is consistent with Longuet-Higgins radiation from oppositely-directed surface waves. Above 6 Hz, the acoustic floor increases with frequency due to distant shipping before falling as ∼ f−2 from 40 to 800 Hz. The noise floor just above the seafloor is only about 5 dB greater than during the 1975 CHURCH OPAL experiment (50–200 Hz), even though these measurements are not subject to the same bathymetric blockage. The floor increases up the array by roughly 15 dB for 40–500 Hz. Immediately above the seafloor, the acoustic energy is concentrated in a narrow, horizontal beam that narrows as f−1 and has a beam width at 75 Hz that is less than the array resolution. The power in the beam falls more steeply with frequency than the omnidirectional spectrum.The OBSANP cruise was funded by the Office of Naval Research under Grant Nos. N00014-10-1-0987, N00014-14- 1-0324, N00014-10-1-0510, and N00014-10-1-0990

Group early intervention eye movement desensitization and reprocessing therapy as a video-conference psychotherapy with frontline/emergency workers in response to the COVID-19 pandemic in the treatment of post-traumatic stress disorder and moral injury—An RCT study

Objective: Frontline mental health, emergency, law enforcement, and social workers have faced unprecedented psychological distress in responding to the COVID-19 pandemic. The purpose of the RCT (Randomized Controls Trial) study was to investigate the effectiveness of a Group EMDR (Eye Movement Desensitization and Reprocessing) therapy (Group Traumatic Episode Protocol—GTEP) in the treatment of Post-Traumatic Stress Disorder (PTSD) and Moral Injury. The treatment focus is an early intervention, group trauma treatment, delivered remotely as video-conference psychotherapy (VCP). This early intervention used an intensive treatment delivery of 4x2h sessions over 1-week. Additionally, the group EMDR intervention utilized therapist rotation in treatment delivery. Methods: The study’s design comprised a delayed (1-month) treatment intervention (control) versus an active group. Measurements included the International Trauma Questionnaire (ITQ), Generalized Anxiety Disorder Assessment (GAD-7), Patient Health Questionnaire (PHQ-9), Moral Injury Events Scale (MIES), and a Quality-of-Life psychometric (EQ-5D), tested at T0, T1: pre—treatment, T2: post-treatment, T3: 1-month follow-up (FU), T4: 3-month FU, and T5: 6-month FU. The Adverse Childhood Experiences – International version (ACEs), Benevolent Childhood Experience (BCEs) was ascertained at pre-treatment only. N = 85 completed the study. Results: Results highlight a significant treatment effect within both active and control groups. Post Hoc comparisons of the ITQ demonstrated a significant difference between T1 pre (mean 36.8, SD 14.8) and T2 post (21.2, 15.1) (t11.58) = 15.68, p < 0.001). Further changes were also seen related to co-morbid factors. Post Hoc comparisons of the GAD-7 demonstrated significant difference between T1 pre (11.2, 4.91) and T2 post (6.49, 4.73) (t = 6.22) = 4.41, p < 0.001; with significant difference also with the PHQ-9 between T1 pre (11.7, 5.68) and T2 post (6.64, 5.79) (t = 6.30) = 3.95, p < 0.001, d = 0.71. The treatment effect occurred irrespective of either ACEs/BCEs during childhood. However, regarding Moral Injury, the MIES demonstrated no treatment effect between T1 pre and T5 6-month FU. The study’s findings discuss the impact of Group EMDR therapy delivered remotely as video-conference psychotherapy (VCP) and the benefits of including a therapist/rotation model as a means of treatment delivery. However, despite promising results suggesting a large treatment effect in the treatment of trauma and adverse memories, including co-morbid symptoms, research results yielded no treatment effect in frontline/emergency workers in addressing moral injury related to the COVID-19 pandemic. Conclusion: The NICE (2018) guidance on PTSD highlighted the paucity of EMDR therapy research used as an early intervention. The primary rationale for this study was to address this critical issue. In summary, treatment results for group EMDR, delivered virtually, intensively, using therapist rotation are tentatively promising, however, the moral dimensions of trauma need consideration for future research, intervention development, and potential for further scalability. The data contributes to the emerging literature on early trauma interventions. Clinical Trial Registration:Clinicaltrials.gov, ISRCTN16933691

The state of the Martian climate

60°N was +2.0°C, relative to the 1981–2010 average value (Fig. 5.1). This marks a new high for the record. The average annual surface air temperature (SAT) anomaly for 2016 for land stations north of starting in 1900, and is a significant increase over the previous highest value of +1.2°C, which was observed in 2007, 2011, and 2015. Average global annual temperatures also showed record values in 2015 and 2016. Currently, the Arctic is warming at more than twice the rate of lower latitudes

Single-cell transcriptomes from human kidneys reveal the cellular identity of renal tumors.

Messenger RNA encodes cellular function and phenotype. In the context of human cancer, it defines the identities of malignant cells and the diversity of tumor tissue. We studied 72,501 single-cell transcriptomes of human renal tumors and normal tissue from fetal, pediatric, and adult kidneys. We matched childhood Wilms tumor with specific fetal cell types, thus providing evidence for the hypothesis that Wilms tumor cells are aberrant fetal cells. In adult renal cell carcinoma, we identified a canonical cancer transcriptome that matched a little-known subtype of proximal convoluted tubular cell. Analyses of the tumor composition defined cancer-associated normal cells and delineated a complex vascular endothelial growth factor (VEGF) signaling circuit. Our findings reveal the precise cellular identities and compositions of human kidney tumors

Single-copy nuclear genes resolve the phylogeny of the holometabolous insects

Background: Evolutionary relationships among the 11 extant orders of insects that undergo complete metamorphosis, called Holometabola, remain either unresolved or contentious, but are extremely important as a context for accurate comparative biology of insect model organisms. The most phylogenetically enigmatic holometabolan insects are Strepsiptera or twisted wing parasites, whose evolutionary relationship to any other insect order is unconfirmed. They have been controversially proposed as the closest relatives of the flies, based on rDNA, and a possible homeotic transformation in the common ancestor of both groups that would make the reduced forewings of Strepsiptera homologous to the reduced hindwings of Diptera. Here we present evidence from nucleotide sequences of six single-copy nuclear protein coding genes used to reconstruct phylogenetic relationships and estimate evolutionary divergence times for all holometabolan orders. Results: Our results strongly support Hymenoptera as the earliest branching holometabolan lineage, the monophyly of the extant orders, including the fleas, and traditionally recognized groupings of Neuropteroidea and Mecopterida. Most significantly, we find strong support for a close relationship between Coleoptera (beetles) and Strepsiptera, a previously proposed, but analytically controversial relationship. Exploratory analyses reveal that this relationship cannot be explained by long-branch attraction or other systematic biases. Bayesian divergence times analysis, with reference to specific fossil constraints, places the origin of Holometabola in the Carboniferous (355 Ma), a date significantly older than previous paleontological and morphological phylogenetic reconstructions. The origin and diversification of most extant insect orders began in the Triassic, but flourished in the Jurassic, with multiple adaptive radiations producing the astounding diversity of insect species for which these groups are so well known. Conclusion: These findings provide the most complete evolutionary framework for future comparative studies on holometabolous model organisms and contribute strong evidence for the resolution of the 'Strepsiptera problem', a long-standing and hotly debated issue in insect phylogenetics

Maternal Administration of Solithromycin, a New, Potent, Broad-Spectrum Fluoroketolide Antibiotic, Achieves Fetal and Intra-Amniotic Antimicrobial Protection in a Pregnant Sheep Model

Solithromycin (CEM-101) is a new antibiotic that is highly potent against Ureaplasma and Mycoplasma spp. and active against many other antibiotic-resistant organisms. We have explored the maternal-amniotic-fetal pharmacokinetics of CEM-101 in a pregnant sheep model to assess its potential for treating intrauterine and antenatal infection. Chronically catheterized pregnant ewes (n = 6 or 7) received either a single maternal intravenous (i.v.) infusion of CEM-101 (10 mg/kg of body weight), a single intra-amniotic (i.a.) injection (1.4 mg/kg of estimated fetal weight), or a combined i.v. and i.a. dose. Maternal plasma (MP), fetal plasma (FP), and amniotic fluid (AF) samples were taken via catheter at intervals of 0 to 72 h postadministration, and concentrations of solithromycin and its bioactive polar metabolites (N-acetyl [NAc]–CEM-101 and CEM-214) were determined. Following maternal i.v. infusion, peak CEM-101 concentrations in MP, FP, and AF were 1,073, 353, and 214 ng/ml, respectively, representing a maternal-to-fetal plasma transfer efficiency of 34%. A single maternal dose resulted in effective concentrations (>30 ng/ml) in MP, FP, and AF sustained for >12 h. NAc–CEM-101 and CEM-214 exhibited delayed accumulation and clearance in FP and AF, resulting in an additive antimicrobial effect (>48 h). Intra-amniotic solithromycin injection resulted in elevated (∼50 μg/ml) and sustained CEM-101 concentrations in AF and significant levels in FP, although the efficiency of amniotic-to-fetal transfer was low (∼1.5%). Combined i.v. and i.a. administration resulted in primarily additive concentrations of CEM-101 in all three compartments. Our findings suggest that CEM-101 may provide, for the first time, an effective antimicrobial approach for the prevention and treatment of intrauterine infection and early prevention of preterm birth

Science Opportunities offered by Mercury's Ice-Bearing Polar Deposits

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