Quantum error correction of a qubit encoded in grid states of an oscillator.

The accuracy of logical operations on quantum bits (qubits) must be improved for quantum computers to outperform classical ones in useful tasks. One method to achieve this is quantum error correction (QEC), which prevents noise in the underlying system from causing logical errors. This approach derives from the reasonable assumption that noise is local, that is, it does not act in a coordinated way on different parts of the physical system. Therefore, if a logical qubit is encoded non-locally, we can-for a limited time-detect and correct noise-induced evolution before it corrupts the encoded information1. In 2001, Gottesman, Kitaev and Preskill (GKP) proposed a hardware-efficient instance of such a non-local qubit: a superposition of position eigenstates that forms grid states of a single oscillator2. However, the implementation of measurements that reveal this noise-induced evolution of the oscillator while preserving the encoded information3-7 has proved to be experimentally challenging, and the only realization reported so far relied on post-selection8,9, which is incompatible with QEC. Here we experimentally prepare square and hexagonal GKP code states through a feedback protocol that incorporates non-destructive measurements that are implemented with a superconducting microwave cavity having the role of the oscillator. We demonstrate QEC of an encoded qubit with suppression of all logical errors, in quantitative agreement with a theoretical estimate based on the measured imperfections of the experiment. Our protocol is applicable to other continuous-variable systems and, in contrast to previous implementations of QEC10-14, can mitigate all logical errors generated by a wide variety of noise processes and facilitate fault-tolerant quantum computation.

The Development of the Mental Toughness Situational Judgment Test: A Novel Approach to Assessing Mental Toughness.

Mental toughness (MT) predicts outcomes across several high-stress contexts such as athletics, the military, and the workplace. Despite this, researchers have struggled to reach consensus regarding how best to conceptualize and measure MT. MT assessments have focused on measuring general MT rather than domain-specific MT. The current study proposed a measurement model of MT grounded in social-cognitive theory and introduced an assessment of MT within a situational judgment context relevant to the workplace. Participants completed the new MT measure as well as assessments to establish construct validity. Both exploratory and confirmatory factor analyses suggested a three-factor solution fit the data best, consisting of task persistence, emotional control, and utilization of feedback. Cross-structure analyses indicated that the new assessment avoided common-method bias in responding, evidenced by weak correlations with measures of other constructs. The results provided initial evidence to continue research on using a situational judgment test to measure MT.

Deterministic Remote Entanglement of Superconducting Circuits through Microwave Two-Photon Transitions.

Large-scale quantum information processing networks will most probably require the entanglement of distant systems that do not interact directly. This can be done by performing entangling gates between standing information carriers, used as memories or local computational resources, and flying ones, acting as quantum buses. We report the deterministic entanglement of two remote transmon qubits by Raman stimulated emission and absorption of a traveling photon wave packet. We achieve a Bell state fidelity of 73%, well explained by losses in the transmission line and decoherence of each qubit.

Continuous Quantum Nondemolition Measurement of the Transverse Component of a Qubit.

Quantum jumps of a qubit are usually observed between its energy eigenstates, also known as its longitudinal pseudospin component. Is it possible, instead, to observe quantum jumps between the transverse superpositions of these eigenstates? We answer positively by presenting the first continuous quantum nondemolition measurement of the transverse component of an individual qubit. In a circuit QED system irradiated by two pump tones, we engineer an effective Hamiltonian whose eigenstates are the transverse qubit states, and a dispersive measurement of the corresponding operator. Such transverse component measurements are a useful tool in the driven-dissipative operation engineering toolbox, which is central to quantum simulation and quantum error correction.

Perineal body length as a risk factor for ultrasound-diagnosed anal sphincter tear at first delivery.

INTRODUCTION AND HYPOTHESIS: Shortened perineal body (PB) is associated with an increased risk of ultrasound-detected obstetric anal sphincter tear. The objective was to determine if shortened perineal body length (<3 cm) is a risk factor for ultrasound-detected anal sphincter tear at first delivery. METHODS: Pregnant nulliparous women were recruited over 18 months. At 35-37 weeks' gestation and 6 weeks' postpartum perineal body length (PB) was measured and subjects completed quality of life questionnaires. Primary outcome was ultrasound-diagnosed anal sphincter tear at 6 weeks postpartum. Secondary outcomes were also assessed. A priori power analysis determined that 70 subjects were needed to detect a difference in anal sphincter tear based on a PB cut-off of 3 cm. RESULTS: Seventy-three subjects completed the study. Mode of delivery was 69.9% spontaneous vaginal, 15.1% operative vaginal, and 15.1% labored cesarean. There were 25 anal sphincter abnormalities (34.2%) seen on ultrasound: 11 (15.1%) internal or external sphincter tears, 3 (4.1%) internal sphincter atrophy, 6 (8.2%) external sphincter thinning, and 7 (9.6%) external sphincter scarring. Only the 11 sphincter tears qualified as abnormal for the primary outcome. In the vaginal delivery group 16.4% (10 out of 61) had a sphincter tear, compared with 8.3% (1 out of 12) in the labored cesarean group (p = 0.68). Women with PB < 3 had a significantly higher rate of ultrasound-diagnosed anal sphincter tear (40.0% vs 11.1%, p = 0.038). When comparing women with and without sphincter tear, there was a significant difference in mean antepartum PB (3.1 vs 3.7 cm, p = 0.043). CONCLUSIONS: A shortened perineal body length in primiparous women is associated with an increased risk of anal sphincter tear at the time of first delivery.

The utility of university fitness facilities: Environmental vs. psychological determinants of their use.

OBJECTIVE: It is important for college students to engage regularly in physical activity. While psychological factors, such as motivation, are likely to increase attendance at fitness facilities, positive perceptions of the fitness facility (e.g., the type of classes offered) might also influence use of a fitness facility. PARTICIPANTS: Data were collected from 462 college students. METHODS: Participants completed a survey that included an assessment of commitment and motivation to exercise, life satisfaction, and perceptions of the environment of the fitness facility they use. They also answered questions about fitness facility preferences. RESULTS: Commitment and motivation to exercise were associated with use of a fitness facility. Perceptions of the environmental context of the fitness facility did not influence attendance. CONCLUSIONS: Even though college students shared some preferences (e.g., workout space and lighting), psychological factors were more influential than the environment of a fitness facility with regard to attendance.

The Actively Caring for People Movement: A Synergistic Integration of Behaviorism, Humanism, and Positive Psychology.

This article reviews the Actively Caring for People (AC4P) Movement, initiated in 2007 to increase occurrences of interpersonal acts of kindness worldwide. Resources to support the AC4P Movement, including research-based training manuals and AC4P wristbands for adults and children, are available at www.ac4p.org. This prosocial movement incorporates principles from three diverse disciplines of psychological science: humanism, positive psychology, and applied behavioral science (ABS). With this article, I explicate seven evidence-based "life lessons" that operationalize select principles from humanism and ABS, and rejuvenate a seemingly forgotten applied psychology concept from the 1970s: humanistic behaviorism. Whenever and wherever practiced, these life lessons benefit human well-being and quality of life. Certain life lessons reflect the essence of empowerment and self-motivation and thereby illustrate critical distinctions between management and leadership. Next, I exemplify synergistic connections between positive psychology and ABS, highlighting practical techniques for promoting and supporting human welfare and personal happiness. Previous and ongoing research by my students and colleagues demonstrates how ABS can apply findings from positive psychology to promote subjective well-being on a large scale. The need for worldwide application and dissemination of practical procedures to increase occurrences of AC4P behavior is strikingly obvious, perhaps more so now than ever before in our contentious, fractured, and polarized society. This article explores evidence-based strategies for increasing occurrences of AC4P behavior in various settings, with the mission to cultivate an AC4P culture in families, educational settings, corporations, and communities throughout the world.

Evaluation of Bacillus anthracis and Yersinia pestis sample collection from nonporous surfaces by quantitative real-time PCR.

AIM: We will validate sample collection methods for recovery of microbial evidence in the event of accidental or intentional release of biological agents into the environment. METHODS AND RESULTS: We evaluated the sample recovery efficiencies of two collection methods - swabs and wipes - for both nonvirulent and virulent strains of Bacillus anthracis and Yersinia pestis from four types of nonporous surfaces: two hydrophilic surfaces, stainless steel and glass, and two hydrophobic surfaces, vinyl and plastic. Sample recovery was quantified using real-time qPCR to assay for intact DNA signatures. We found no consistent difference in collection efficiency between swabs or wipes. Furthermore, collection efficiency was more surface-dependent for virulent strains than nonvirulent strains. For the two nonvirulent strains, collection efficiency was similar between all four surfaces, albeit B. anthracis Sterne exhibited higher levels of recovery compared to Y. pestis A1122. In contrast, recovery of B. anthracis Ames spores and Y. pestis CO92 from the hydrophilic glass or stainless steel surfaces was generally more efficient compared to collection from the hydrophobic vinyl and plastic surfaces. CONCLUSIONS: Our results suggest that surface hydrophobicity may play a role in the strength of pathogen adhesion. The surface-dependent collection efficiencies observed with the virulent strains may arise from strain-specific expression of capsular material or other cell surface receptors that alter cell adhesion to specific surfaces. SIGNIFICANCE AND IMPACT OF THE STUDY: These findings contribute to the validation of standard bioforensics procedures and emphasize the importance of specific strain and surface interactions in pathogen detection.

Cdc42 and Rac stimulate exocytosis of secretory granules by activating the IP(3)/calcium pathway in RBL-2H3 mast cells.

We have expressed dominant-active and dominant-negative forms of the Rho GTPases, Cdc42 and Rac, using vaccinia virus to evaluate the effects of these mutants on the signaling pathway leading to the degranulation of secretory granules in RBL-2H3 cells. Dominant-active Cdc42 and Rac enhance antigen-stimulated secretion by about twofold, whereas the dominant-negative mutants significantly inhibit secretion. Interestingly, treatment with the calcium ionophore, A23187, and the PKC activator, PMA, rescues the inhibited levels of secretion in cells expressing the dominant-negative mutants, implying that Cdc42 and Rac act upstream of the calcium influx pathway. Furthermore, cells expressing the dominant-active mutants exhibit elevated levels of antigen-stimulated IP(3) production, an amplified antigen-stimulated calcium response consisting of both calcium release from internal stores and influx from the extracellular medium, and an increase in aggregate formation of the IP(3) receptor. In contrast, cells expressing the dominant-negative mutants display the opposite phenotypes. Finally, we are able to detect an in vitro interaction between Cdc42 and PLCgamma1, the enzyme immediately upstream of IP(3) formation. Taken together, these findings implicate Cdc42 and Rac in regulating the exocytosis of secretory granules by stimulation of IP(3) formation and calcium mobilization upon antigen stimulation.

Maturation of a stress-activated mechanism inhibiting induction of tyrosine transaminase.

Rats of various ages were subjected to the stress of 30 minutes on a noisy reciprocating shaker 4 hours before their liver tyrosine transaminase and tryptophan pyrrolase activities were measured. Adrenalectomized infants and adults and hypophysectomized adults were also stressed. Intact, stressed infants exhibited an increase in tyrosine transaminase activity, while intact, stressed adults showed no change. In the stressed adrenalectomized adult, tyrosine transaminase activity markedly decreased, while adrenalectomized infants showed no change. Hypophysectomy largely, but not completely, abolished inhibition in the adults. Tryptophan pyrrolase activity, when present, was increased by stress in all age groups, but the increase was abolished by adrenalectomy and hypophysectomy. The results suggest stress-activation of a pituitary mechanism that inhibits or represses activation of tyrosine transaminase and that may not function during early postnatal life.

Classification of opioids on the basis of change in seizure threshold in rats.

Twenty opioids have been subdivided into four classes by using flurothyl-induced seizures in rats to measure dose-response relationships, stereospecificity, naloxone sensitivity, and tolerance-cross-tolerance. The data support current theories of multiple opiate receptor types. Since the receptors involved mediate effects that are antagonized, enhanced, or unaffected by naloxone, the model is uniquely suitable for detecting novel narcotic antagonists that can then be used to differentiate opiate receptors in other systems.

Harderian gland: development and influence of early hormonal treatment on porphyrin content.

The porphyrin content of the rat Harderian gland remains low until 12 days of age at which time both porphyrin content and concentration rapidly increase. Intraperitoneal administration of tetraiodothyronine (thyroxine) into newborn animals advances the appearance of porphyrin in the gland. Conversely, a single injection of cortisol acetate into newborns retards the appearance of porphyrin. The time of porphyrin appearance in the gland parallels the time for maturation of the evoked cortical response to visual stimulation in normal and hormone-treated animals.

Harderian gland: an extraretinal photoreceptor influencing the pineal gland in neonatal rats?

The circadian rhythm of pineal serotonin and the influence of light on that rhythm have been confirmed. Removal of the Harderian gland abolishes the response to light in blinded animals, which suggests that this gland may act as the extraretinal transducer involved in the persistence of the pineal rhythm in blinded suckling rats.

Harderian gland: influence on pineal hydroxyindole-O-methyltransferase activity in neonatal rats.

A circadian rhythm has been found in hydroxyindole-O-methyltransferase activity of the pineal gland of blinded 12-day-old rats. Five additional hours of lighting can partly prevent the nocturnal increase in pineal hydroxyindole-O-methyltransferase activity in such rats. Removal of the Harderian gland abolishes this response to light in 12-day-old blinded animals, giving further support to the suggestion that this gland may function as an extraretinal photosensitive organ influencing the pineal gland in blinded suckling rats.

Reducing excessive alcohol consumption at university fraternity parties: a cost-effective incentive/reward intervention.

The impact of an incentive/reward intervention on college students' intoxication from alcohol consumption at fraternity parties was explored using a group-randomized trial. Participants included 702 college students (447 men, 225 women) attending fraternity parties in Blacksburg, VA. Six fraternities were randomly assigned to a control or experimental group, and each of these fraternities hosted two parties. The three fraternities in the experimental group hosted a baseline party first and then hosted an intervention party at which those having a blood alcohol concentration (BAC) level below 0.05 were entered in a $100 cash lottery. The three fraternities in the control group hosted two control (non-intervention) parties. For the experimental fraternities, mean BAC levels were significantly lower at the intervention parties (M=0.079) than the baseline parties (M=0.098) and the percentage of party-goers with a BAC below 0.08 was significantly higher at intervention parties (40.1%) than at baseline parties (30.6%). This field study supports the efficacy of differential reinforcement in controlling student intoxication at party settings.

Mutant RBL mast cells defective in Fc epsilon RI signaling and lipid raft biosynthesis are reconstituted by activated Rho-family GTPases.

Characterization of defects in a variant subline of RBL mast cells has revealed a biochemical event proximal to IgE receptor (Fc epsilon RI)-stimulated tyrosine phosphorylation that is required for multiple functional responses. This cell line, designated B6A4C1, is deficient in both Fc epsilon RI-mediated degranulation and biosynthesis of several lipid raft components. Agents that bypass receptor-mediated Ca(2+) influx stimulate strong degranulation responses in these variant cells. Cross-linking of IgE-Fc epsilon RI on these cells stimulates robust tyrosine phosphorylation but fails to mobilize a sustained Ca(2+) response. Fc epsilon RI-mediated inositol phosphate production is not detectable in these cells, and failure of adenosine receptors to mobilize Ca(2+) suggests a general deficiency in stimulated phospholipase C activity. Antigen stimulation of phospholipases A(2) and D is also defective. Infection of B6A4C1 cells with vaccinia virus constructs expressing constitutively active Rho family members Cdc42 and Rac restores antigen-stimulated degranulation, and active Cdc42 (but not active Rac) restores ganglioside and GPI expression. The results support the hypothesis that activation of Cdc42 and/or Rac is critical for Fc epsilon RI-mediated signaling that leads to Ca(2+) mobilization and degranulation. Furthermore, they suggest that Cdc42 plays an important role in the biosynthesis and expression of certain components of lipid rafts.

Prompting safety-belt use in the context of a belt-use law: the flash-for life revisited.

PROBLEM: Safety-belt use reduces motor vehicle crash-related morbidity and mortality, yet an estimated 18% of drivers do not consistently buckle up (NHTSA, 2005). In 1985, Geller and colleagues developed an interpersonal Flash-for-Life prompt that increased belt use among 22% of 1,087 unbuckled drivers (Geller, Bruff, & Nimmer, 1985). METHOD: The Flash-for-Life intervention was re-introduced at a large university with high safety-belt use (i.e., 80%). College students stood at parking-lot entrance/exits and "flashed" signs with the message, "Please Buckle Up, I Care" to unbuckled drivers. RESULTS: Of 427 unbuckled drivers observed, 30% of these complied with the prompt. Male drivers were significantly more likely to comply with prompts delivered by females. DISCUSSION: Compliance was higher than in the 1985 study, indicating a high baseline rate of safety-belt use does not negate potential beneficial influence of a prompting intervention. This intervention is particularly effective with college-aged males, a sub-group of the driving population least likely to buckle-up. IMPACT ON INDUSTRY: A simple behavioral prompt could be used at most industrial complexes to increase safety-belt use among vehicle occupants who are not buckled-up.

Intervening to promote pay-it-forward behavior: Does perceived self-motivation of the benefactor matter?

Pay-it-forward behavior reflects actively caring for people (AC4P) and the reciprocity principle. Interventions to increase the frequency of pay-it-forward behavior were evaluated. At a buffet-style dining hall, a research assistant (RA) entered the line and paid for the next person's meal. In the Sign Intervention Phase, the RA discreetly paid for the next person's meal. In the Verbal + Sign Intervention Phase, the RA verbally activated reciprocity and paid for the next diner's meal. For Baseline and Withdrawal, a sign prompted the purchase of another person's meal. The Verbal + Sign Intervention was significantly more effective at activating pay-it-forward behavior (24.6% of 171) than the Sign Intervention (15.6% of 122), Baseline (6.8% of 148), and Withdrawal (12.6% of 95). These results were contrary to the research hypothesis that verbal and sign prompting would decrease perceived self-motivation of the benefactor and thereby reduce the beneficiary's perceived obligation to pay it forward.

Actively caring to prevent bullying in an elementary school: Prompting and rewarding prosocial behavior.

This field study evaluated the impact of an intervention designed to prevent bullying among elementary-school students by prompting and rewarding prosocial behavior. More specifically, teachers of 404 second-, third-, fourth-, fifth-, and sixth-grade students from an elementary school in northeast Virginia asked their students to look out for other students' prosocial behaviors (termed "actively caring") and to submit their stories about actively caring. At the start of every class day, the teachers read three of these stories and recognized one story and the two associated students (i.e., the observer and the performer) by providing each with a wristband engraved with "Actively Caring for People." For six consecutive Fridays, students reported their observations of bullying and completed a single item estimate of self-esteem. Weekly surveys revealed reductions in "being bullied" and "bullying others," as well as an increase in self-esteem.