Demonstration of Tunable Three-Body Interactions between Superconducting Qubits.

Nonpairwise multiqubit interactions present a useful resource for quantum information processors. Their implementation would facilitate more efficient quantum simulations of molecules and combinatorial optimization problems, and they could simplify error suppression and error correction schemes. Here, we present a superconducting circuit architecture in which a coupling module mediates two-local and three-local interactions between three flux qubits by design. The system Hamiltonian is estimated via multiqubit pulse sequences that implement Ramsey-type interferometry between all neighboring excitation manifolds in the system. The three-local interaction is coherently tunable over several MHz via the coupler flux biases and can be turned off, which is important for applications in quantum annealing, analog quantum simulation, and gate-model quantum computation.

Eccrine Porocarcinoma Presenting as a Hand Cyst.

Eccrine porocarcinoma is a rare tumor that arises from the epithelium of the eccrine ducts, with a tendency for metastatic spread and a high rate of local recurrence after excision. It was first described in 1963 by Pinkus and Mehregan and can present clinically as a nodule, erosive plaque or a polypoid growth that may ulcerate. The variable clinical appearance of these lesions can make diagnosis challenging and could delay appropriate treatment. If metastasis occurs the prognosis is poor, with a reported mortality rate of up to 80%. We report an uncommon presentation of porocarcinoma as a cyst on the dorsum of the right hand in a 37-year-old man. Only 8% of porocarcinomas occur in the upper extremity and only 3% are on the hand. Furthermore, the tumor is more common in females and mean age at diagnosis is 67 years. Treatment is with wide local excision with free tumor borders confirmed by biopsy, which has been shown to be curative in 70% to 80% of patients.

Comparison of a Padded Patient Litter and Long Spine Board for Spinal Immobilization in Air Medical Transport.

OBJECTIVE: The long spinal board is the immobilization standard during prehospital transport. The flat surface of the board increases the pressure placed on both the thoracic kyphosis and the sacrum and increases the risk for pressure ulcers. This study compared patient stability and comfort between a padded litter system used in air medical transport and the long spine board. METHODS: The study was completed at a large 350-bed Magnet Recognized nonteaching hospital. The hospital owns and operates an air medical transport service. Subjects were secured to a padded litter and a long spinal board with a cervical collar and head blocks and 3 straps. Laser pointers were used to mark neutral at points on the subject's head, sternum, and pelvis. The subject was tilted 45 degrees left and right with movement measured in inches. Comfort level was measured before and after. Paired t-tests were used to detect differences in movement. RESULTS: No statistical difference in movement was found between devices for the head; however, there was statistically significant greater movement on the padded litter for the sternum and pelvis. CONCLUSION: The padded litter did not immobilize as tightly as the long board although the effect of the differences was small.

Early pseudoaneurysm degeneration in biologic extracellular matrix patch for carotid repair.

A newly-approved carotid patch, derived from porcine small intestinal submucosa (SIS), is thought to allow functional tissue regeneration by acting as a biologic scaffold of extracellular matrix. We report three cases of asymptomatic pseudoaneurysm after SIS patch closure. At exploration there were intact suture lines, no growth from cultures, and central patch herniation. Histopathologic examination showed postendarterectomy neointima in the artery and disorganized collagen in the pseudoaneurysm. SIS patch remnants adjacent to macrophage infiltration and neovascularization indicated ongoing processes of degradation and synthesis. Imbalances between degradation and host tissue synthesis are problems that may unpredictably affect SIS patch integrity.

Comparative statistical study of hourly precipitation determined by radar-based stage IV and ground-based methods in the North Central United States.

UNLABELLED: Detailed hourly precipitation data are required for long-range modeling of dispersion and wet deposition of particulate matter and water-soluble pollutants using the CALPUFF model. In sparsely populated areas such as the north central United States, ground-based precipitation measurement stations may be too widely spaced to offer a complete and accurate spatial representation of hourly precipitation within a modeling domain. The availability of remotely sensed precipitation data by satellite and the National Weather Service array of next-generation radars (NEXRAD) deployed nationally provide an opportunity to improve on the paucity of data for these areas. Before adopting a new method of precipitation estimation in a modeling protocol, it should be compared with the ground-based precipitation measurements, which are currently relied upon for modeling purposes. This paper presents a statistical comparison between hourly precipitation measurements for the years 2006 through 2008 at 25 ground-based stations in the north central United States and radar-based precipitation measurements available from the National Center for Environmental Predictions (NCEP) as Stage IV data at the nearest grid cell to each selected precipitation station. It was found that the statistical agreement between the two methods depends strongly on whether the ground-based hourly precipitation is measured to within 0.1 in/ hr or to within 0.01 in/hr. The results of the statistical comparison indicate that it would be more accurate to use gridded Stage IV precipitation data in a gridded dispersion model for a long-range simulation, than to rely on precipitation data interpolated between widely scattered rain gauges. IMPLICATIONS: The current reliance on ground-based rain gauges for precipitation events and hourly data for modeling of dispersion and wet deposition of particulate matter and water-soluble pollutants results in potentially large discontinuity in data coverage and the need to extrapolate data between monitoring stations. The use of radar-based precipitation data, which is available for the entire continental United States and nearby areas, would resolve these data gaps and provide a complete and accurate spatial representation of hourly precipitation within a large modeling domain.

Can a Modified Y-Balance Test Predict Running Overuse Injuries over the Course of a Division I Collegiate Cross-Country Season?

BACKGROUND: Collegiate distance runners often suffer from running overuse injuries (ROI). The Y-Balance Test (YBT) has the potential to predict ROI risk in collegiate runners. PURPOSE: To investigate whether a preseason clinical assessment of dynamic balance, through a modified version of the YBT (mYBT), can predict risk of ROIs during one NCAA Division I cross-country (XC) season. STUDY DESIGN: Prospective case-control study. METHODS: Participants from a Division I XC team were screened for mYBT performance in four directions: anterior (AN), posteromedial (PM), posterolateral (PL), and posterior (PO). ROIs were tracked over the course of the XC season. Receiver operating characteristic (ROC) curve analysis (α = 0.05) was utilized to investigate the effectiveness of the mYBT in predicting injury risk. RESULTS: Nine (5 female, 4 male) of 29 runners developed an ROI during the XC season. Five components of the mYBT were found to predict injuries, including normalized nondominant PO score (AUC = 0.756, p = 0.03; RR = 1.90), AN raw difference and limb asymmetry (AUC = 0.808, p = 0.01), and PM raw difference and limb asymmetry in males (AUC = 0.958, p = 0.02). CONCLUSION: Specific components of the mYBT can help predict the risk of developing a running overuse injury over one Division I XC season. LEVEL OF EVIDENCE: Screening, Level 3.

Correction: Journey to the east: Diverse routes and variable flowering times for wheat and barley en route to prehistoric China.

[This corrects the article DOI: 10.1371/journal.pone.0187405.].

Humoral immune responses to influenza vaccination in patients with obstructive sleep apnea.

STUDY OBJECTIVE: To compare humoral immune responses to influenza vaccination in subjects with obstructive sleep apnea (OSA) and in healthy volunteers (control subjects). DESIGN: Prospective, controlled, parallel-design study. SETTING: Sleep disorders center at a university hospital. SUBJECTS: Fourteen untreated subjects with moderate-to-severe OSA (apnea hypopnea index > 15 events/hr) and 17 healthy volunteers (control subjects). INTERVENTION: All subjects were given the influenza vaccine for the years 2004-2005 or 2005-2006. MEASUREMENTS AND MAIN RESULTS: Blood samples were obtained before and 2-4 weeks after vaccination to measure serum antibody titers for the A/New Caledonia/20/99 (H1N1)-like and B/Shanghai/361/2002-like viral strains by using the hemagglutination inhibition assay. Seroconversion was defined as an increase in the antibody titer by more than 4-fold, whereas seroprotection was defined as an antibody titer greater than 40 hemagglutination units. The mean +/- standard error of the mean apnea hypopnea index, calculated as the number of abnormal respiratory events divided by the number of hours of total sleep time, was 56 +/- 12 events/hour in the OSA group and 1.0 +/- 0.4 oxygen desaturations/hour in the control group (p<0.05). However, no significant differences were observed in changes in antibody concentration, frequencies of seroconversion, or rates of seroprotection between subjects with OSA and control subjects. Polysomnographic measures of OSA were not correlated with immune responses. CONCLUSION: Although pathophysiologic characteristics of OSA may influence immune responses, moderate-to-severe OSA did not impair humoral responses to the influenza vaccine in these subjects.

Adaptation to altitude as a vehicle for experiential learning of physiology by university undergraduates.

In this article, an experiential learning activity is described in which 19 university undergraduates made experimental observations on each other to explore physiological adaptations to high altitude. Following 2 wk of didactic sessions and baseline data collection at sea level, the group ascended to a research station at 12,500-ft elevation. Here, teams of three to four students measured the maximal rate of oxygen uptake, cognitive function, hand and foot volume changes, reticulocyte count and hematocrit, urinary pH and 24-h urine volume, athletic performance, and nocturnal blood oxygen saturation. Their data allowed the students to quantify the effect of altitude on the oxygen cascade and to demonstrate the following altitude-related changes: 1) impaired performance on selected cognitive function tests, 2) mild peripheral edema, 3) rapid reticulocytosis, 4) urinary alkalinization and diuresis, 5) impaired aerobic but not anaerobic exercise performance, 6) inverse relationship between blood oxygen saturation and resting heart rate, and 7) regular periodic nocturnal oxygen desaturation events accompanied by heart rate accelerations. The students learned and applied basic statistical techniques to analyze their data, and each team summarized its results in the format of a scientific paper. The students were uniformly enthusiastic about the use of self-directed experimentation to explore the physiology of altitude adaptation and felt that they learned more from this course format than a control group of students felt that they learned from a physiology course taught by the same instructor in the standard classroom/laboratory format.

Journey to the east: Diverse routes and variable flowering times for wheat and barley en route to prehistoric China.

Today, farmers in many regions of eastern Asia sow their barley grains in the spring and harvest them in the autumn of the same year (spring barley). However, when it was first domesticated in southwest Asia, barley was grown between the autumn and subsequent spring (winter barley), to complete their life cycles before the summer drought. The question of when the eastern barley shifted from the original winter habit to flexible growing schedules is of significance in terms of understanding its spread. This article investigates when barley cultivation dispersed from southwest Asia to regions of eastern Asia and how the eastern spring barley evolved in this context. We report 70 new radiocarbon measurements obtained directly from barley grains recovered from archaeological sites in eastern Eurasia. Our results indicate that the eastern dispersals of wheat and barley were distinct in both space and time. We infer that barley had been cultivated in a range of markedly contrasting environments by the second millennium BC. In this context, we consider the distribution of known haplotypes of a flowering-time gene in barley, Ppd-H1, and infer that the distributions of those haplotypes may reflect the early dispersal of barley. These patterns of dispersal resonate with the second and first millennia BC textual records documenting sowing and harvesting times for barley in central/eastern China.

Suppressing relaxation in superconducting qubits by quasiparticle pumping.

Dynamical error suppression techniques are commonly used to improve coherence in quantum systems. They reduce dephasing errors by applying control pulses designed to reverse erroneous coherent evolution driven by environmental noise. However, such methods cannot correct for irreversible processes such as energy relaxation. We investigate a complementary, stochastic approach to reducing errors: Instead of deterministically reversing the unwanted qubit evolution, we use control pulses to shape the noise environment dynamically. In the context of superconducting qubits, we implement a pumping sequence to reduce the number of unpaired electrons (quasiparticles) in close proximity to the device. A 70% reduction in the quasiparticle density results in a threefold enhancement in qubit relaxation times and a comparable reduction in coherence variability.

Disseminated vaccinia false alarm.

We report the case of a 6-year-old girl who presented in December 2002 with fever and a vesicular rash. Initially she was diagnosed with Stevens-Johnson syndrome. The differential diagnosis was expanded, however, when an exposure to a person who was believed to be vaccinated recently against smallpox was revealed. We describe the sequence of events that ensued and the workup for a possible case of disseminated virus.

Sleep architecture in children with idiopathic generalized epilepsy.

PURPOSE: Children with epilepsy experience sleep disturbances, behavioral and attentional problems at higher rates than their peers. However, the relation between sleep disturbances and the observed behavioral and attentional abnormalities is poorly defined. METHODS: Children with primary generalized epilepsy who were seizure free and between the ages of 5 and 18 years were matched with age- and gender-matched healthy controls and underwent two consecutive nights of nocturnal polysomnography with extended electroencephalography. Connor's Continuous Performance Test (CPT) was administered to assess daytime attentional function. Parents completed the Child Behavior Checklist (CBCL) to assess their emotional-behavioral status. Two sample t tests were used to examine group differences. Spearman correlations were used to examine the relation between sleep variables and behavior and attention variables. Multiple regression analysis was used to identify independent predictors of abnormal behavior and attention among patients. RESULTS: Eleven children with primary generalized epilepsy and eight age- and sex-matched controls participated in the study. Children with epilepsy had longer stage 1 sleep percentage (7.19 +/- 3.2 vs. 4.8 +/- 3.5; p = 0.05) and latency to rapid-eye-movement (REM) sleep (123.5 +/- 40.1 vs. 101.75 +/- 24.3; p = 0.018) compared with controls. Children with epilepsy had worse attention (CPT index, 10.94 +/- 6.55 vs. 3.42 +/- 4.04; p = 0.004) and exhibited significantly higher CBCL Total Behavior and Internalizing Behavior Problem scales. Whereas regression analysis showed no independent predictors of abnormal behavior and attention, a tendency toward association between CBCL total behavior scale and REM percentage (r= 0.55; p = 0.07), and between CPT overall index and stage 1 sleep percentage (r= 0.40; p = 0.10) was noted. CONCLUSIONS: Sleep architecture is abnormal in children with primary generalized epilepsy. Further studies are needed to determine whether abnormalities in sleep architecture contribute to poor daytime behavior and attention.

Hepatic clearance and drug metabolism using isolated perfused rat liver.

The isolated perfused rat liver (IPRL) has been extensively used as an intact organ model for determination of hepatic clearance and metabolism of drugs. The IPRL model can also be applied to determine physiologically based pharmacokinetics. Since the IPRL model avoids neural and hormonal interferences and excludes influences from absorption processes and non-hepatic elimination routes such as renal excretion and respiration, it provides a relatively clean hepatic system to study metabolism and pharmacokinetics. It is especially useful to model the hepatic uptake associated with plasma protein binding and transport. The viability of the liver can be evaluated based on the gross appearance, bile flow, perfusion pressure, lactate dehydrogenase release, and oxygen uptake. The protocol describes the surgical procedures for isolation of the rat liver, a hemoglobin-free perfusion method, and application of this model for determination of hepatic uptake and clearance.