Exploiting Nonclassical Motion of a Trapped Ion Crystal for Quantum-Enhanced Metrology of Global and Differential Spin Rotations.

We theoretically investigate prospects for the creation of nonclassical spin states in trapped ion arrays by coupling to a squeezed state of the collective motion of the ions. The correlations of the generated spin states can be tailored for quantum-enhanced sensing of global or differential rotations of subensembles of the spins by working with specific vibrational modes of the ion array. We propose a pair of protocols to utilize the generated states and demonstrate their viability even for small systems, while assessing limitations imposed by spin-motion entanglement and technical noise. Our work suggests new opportunities for the preparation of many-body states with tailored correlations for quantum-enhanced metrology in spin-boson systems.

EELS: Autonomous snake-like robot with task and motion planning capabilities for ice world exploration.

Ice worlds are at the forefront of astrobiological interest because of the evidence of subsurface oceans. Enceladus in particular is unique among the icy moons because there are known vent systems that are likely connected to a subsurface ocean, through which the ocean water is ejected to space. An existing study has shown that sending small robots into the vents and directly sampling the ocean water is likely possible. To enable such a mission, NASA's Jet Propulsion Laboratory is developing a snake-like robot called Exobiology Extant Life Surveyor (EELS) that can navigate Enceladus' extreme surface and descend an erupting vent to capture unaltered liquid samples and potentially reach the ocean. However, navigating to and through Enceladus' environment is challenging: Because of the limitations of existing orbital reconnaissance, there is substantial uncertainty with respect to its geometry and the physical properties of the surface/vents; communication is limited, which requires highly autonomous robots to execute the mission with limited human supervision. Here, we provide an overview of the EELS project and its development effort to create a risk-aware autonomous robot to navigate these extreme ice terrains/environments. We describe the robot's architecture and the technical challenges to navigate and sense the icy environment safely and effectively. We focus on the challenges related to surface mobility, task and motion planning under uncertainty, and risk quantification. We provide initial results on mobility and risk-aware task and motion planning from field tests and simulated scenarios.

Detecting Out-of-Time-Order Correlations via Quasiadiabatic Echoes as a Tool to Reveal Quantum Coherence in Equilibrium Quantum Phase Transitions.

We propose a new dynamical method to connect equilibrium quantum phase transitions and quantum coherence using out-of-time-order correlations (OTOCs). Adopting the iconic Lipkin-Meshkov-Glick and transverse-field Ising models as illustrative examples, we show that an abrupt change in coherence and entanglement of the ground state across a quantum phase transition is observable in the spectrum of multiple quantum coherence intensities, which are a special type of OTOC. We also develop a robust protocol to obtain the relevant OTOCs using quasi-adiabatic quenches through the ground state phase diagram. Our scheme allows for the detection of OTOCs without time reversal of coherent dynamics, making it applicable and important for a broad range of current experiments where time reversal cannot be achieved by inverting the sign of the underlying Hamiltonian.

Author Correction: Unifying scrambling, thermalization and entanglement through measurement of fidelity out-of-time-order correlators in the Dicke model.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Unifying scrambling, thermalization and entanglement through measurement of fidelity out-of-time-order correlators in the Dicke model.

Scrambling is the process by which information stored in local degrees of freedom spreads over the many-body degrees of freedom of a quantum system, becoming inaccessible to local probes and apparently lost. Scrambling and entanglement can reconcile seemingly unrelated behaviors including thermalization of isolated quantum systems and information loss in black holes. Here, we demonstrate that fidelity out-of-time-order correlators (FOTOCs) can elucidate connections between scrambling, entanglement, ergodicity and quantum chaos (butterfly effect). We compute FOTOCs for the paradigmatic Dicke model, and show they can measure subsystem Rényi entropies and inform about quantum thermalization. Moreover, we illustrate why FOTOCs give access to a simple relation between quantum and classical Lyapunov exponents in a chaotic system without finite-size effects. Our results open a path to experimental use FOTOCs to explore scrambling, bounds on quantum information processing and investigation of black hole analogs in controllable quantum systems.

Verification of a Many-Ion Simulator of the Dicke Model Through Slow Quenches across a Phase Transition.

We use a self-assembled two-dimensional Coulomb crystal of ∼70 ions in the presence of an external transverse field to engineer a simulator of the Dicke Hamiltonian, an iconic model in quantum optics which features a quantum phase transition between a superradiant (ferromagnetic) and a normal (paramagnetic) phase. We experimentally implement slow quenches across the quantum critical point and benchmark the dynamics and the performance of the simulator through extensive theory-experiment comparisons which show excellent agreement. The implementation of the Dicke model in fully controllable trapped ion arrays can open a path for the generation of highly entangled states useful for enhanced metrology and the observation of scrambling and quantum chaos in a many-body system.

Solving the Quantum Many-Body Problem via Correlations Measured with a Momentum Microscope.

In quantum many-body theory, all physical observables are described in terms of correlation functions between particle creation or annihilation operators. Measurement of such correlation functions can therefore be regarded as an operational solution to the quantum many-body problem. Here, we demonstrate this paradigm by measuring multiparticle momentum correlations up to third order between ultracold helium atoms in an s-wave scattering halo of colliding Bose-Einstein condensates, using a quantum many-body momentum microscope. Our measurements allow us to extract a key building block of all higher-order correlations in this system-the pairing field amplitude. In addition, we demonstrate a record violation of the classical Cauchy-Schwarz inequality for correlated atom pairs and triples. Measuring multiparticle momentum correlations could provide new insights into effects such as unconventional superconductivity and many-body localization.

Quantum-Enhanced Sensing Based on Time Reversal of Nonlinear Dynamics.

We experimentally demonstrate a nonlinear detection scheme exploiting time-reversal dynamics that disentangles continuous variable entangled states for feasible readout. Spin-exchange dynamics of Bose-Einstein condensates is used as the nonlinear mechanism which not only generates entangled states but can also be time reversed by controlled phase imprinting. For demonstration of a quantum-enhanced measurement we construct an active atom SU(1,1) interferometer, where entangled state preparation and nonlinear readout both consist of parametric amplification. This scheme is capable of exhausting the quantum resource by detecting solely mean atom numbers. Controlled nonlinear transformations widen the spectrum of useful entangled states for applied quantum technologies.

Single-stage resection and microwave ablation for bilobar colorectal liver metastases.

BACKGROUND: Patients undergoing liver resection combined with microwave ablation (MWA) for bilobar colorectal metastasis may have similar overall survival to patients who undergo two-stage hepatectomy, but with less morbidity. METHODS: This was a multi-institutional evaluation of patients who underwent MWA between 2003 and 2012. Morbidity (90-day) and mortality were compared between patients who had MWA alone and those who underwent combined resection and MWA (CRA). Mortality and overall survival after CRA were compared with published data on two-stage resections. RESULTS: Some 201 patients with bilobar colorectal liver metastasis treated with MWA from four high-volume institutions were evaluated (100 MWA alone, 101 CRA). Patients who had MWA alone were older, but the groups were otherwise well matched demographically. The tumour burden was higher in the CRA group (mean number of lesions 3·9 versus 2·2; P = 0·003). Overall (31·7 versus 15·0 per cent; P = 0·006) and high-grade (13·9 versus 5·0 per cent; P = 0·030) complication rates were higher in the CRA group. Median overall survival was slightly shorter in the CRA group (38·4 versus 42·2 months; P = 0·132) but disease-free survival was similar (10·1 versus 9·3 months; P = 0·525). The morbidity and mortality of CRA compared favourably with rates in the existing literature on two-stage resection, and survival data were similar. CONCLUSION: Single-stage hepatectomy and MWA resulted in survival similar to that following two-stage hepatectomy, with less overall morbidity.

Robotic pancreaticoduodenectomy: comparison of complications and cost to the open approach.

BACKGROUND: Robotic pancreaticoduodenectomy (RP) has shown some advantages over open pancreaticoduodenectomy (OP) but no data has been published providing a cost comparison. METHODS: Retrospective analysis of all pancreaticoduodenectomies at a single quaternary cancer referral center was performed. Patient demographics, comorbidities, operative characteristics, complications, and charge data were recorded, and then compared using standard statistical methods. RESULTS: 71 pancreaticoduodenectomies were performed: 22 RP and 49 OP. Patients undergoing OP had similar demographics, comorbidities, pathology, and oncologic characteristics as patients undergoing RP. While operative charges were higher for RP, once inpatient stay associated costs and follow-up costs were included, there was no difference in total costs between RP and OP. CONCLUSIONS: Patients undergoing RP have equivalent rates of R0 resection as OP, and benefit from decreased number of complications, surgical site infections, and length of stay in the intensive care unit. Once cost of complications and follow-up are incorporated, no significant difference between procedures exists. Copyright © 2015 John Wiley & Sons, Ltd.

Proposal for demonstrating the Hong-Ou-Mandel effect with matter waves.

The Hong-Ou-Mandel effect is a demonstration of destructive quantum interference between pairs of indistinguishable bosons, realised so far only with massless photons. Here we propose an experiment to realize this effect in the matter-wave regime using pair-correlated atoms produced via a collision of two Bose-Einstein condensates and subjected to two laser--induced Bragg pulses. We formulate a measurement protocol for the multimode matter-wave field, which--unlike the typical two-mode optical case-bypasses the need for repeated measurements under different displacement settings of the beam splitter, markedly reducing the number of experimental runs required to map out the interference visibility. Although the protocol can be used in related matter-wave schemes, we focus on condensate collisions. By simulating the entire experiment, we predict a Hong-Ou-Mandel dip visibility of ~69%. This visibility highlights strong quantum correlations between the atoms, paving the way for a possible demonstration of a Bell inequality violation with massive particles in a related Rarity-Tapster setup.

AAV serotype 2/1-mediated gene delivery of anti-inflammatory interleukin-10 enhances neurogenesis and cognitive function in APP+PS1 mice.

Brain inflammation is a double-edged sword. It is required for brain repair in acute damage, whereas chronic inflammation and autoimmune disorders are neuropathogenic. Certain proinflammatory cytokines and chemokines are closely related to cognitive dysfunction and neurodegeneration. Representative anti-inflammatory cytokines, such as interleukin (IL)-10, can suppress neuroinflammation and have significant therapeutic potentials in ameliorating neurodegenerative disorders such as Alzheimer's disease (AD). Here, we show that adeno-associated virus (AAV) serotype 2/1 hybrid-mediated neuronal expression of the mouse IL-10 gene ameliorates cognitive dysfunction in amyloid precursor protein+ presenilin-1 bigenic mice. AAV2/1 infection of hippocampal neurons resulted in sustained expression of IL-10 without its leakage into the blood, reduced astro/microgliosis, enhanced plasma amyloid-ß peptide (Aß) levels and enhanced neurogenesis. Moreover, increased levels of IL-10 improved spatial learning, as determined by the radial arm water maze. Finally, IL-10-stimulated microglia enhanced proliferation but not differentiation of primary neural stem cells in the co-culture system, whereas IL-10 itself had no effect. Our data suggest that IL-10 gene delivery has a therapeutic potential for a non-Aß-targeted treatment of AD.

Evaluation of absorbable and permanent mesh fixation devices: adhesion formation and mechanical strength.

PURPOSE: Laparoscopic ventral hernia repair is commonly performed with mesh prostheses; however, there is no standard for fixation devices used to secure mesh to the abdominal wall. This study is a functional comparison of novel, screw-type absorbable and permanent fixation devices with a traditional titanium fixation device. METHODS: Fifteen pigs each underwent the laparoscopic placement of two 11 × 14-cm mesh prostheses and were randomized for mesh fixation with either titanium spiral tacks (TS), absorbable screw-type fasteners (SF), or permanent screw-type fasteners (PF) (n = 10 mesh prostheses for each fixation group). Adhesions were assessed laparoscopically at 4 weeks. The fixation devices were also embedded in porcine abdominal rectus muscle for ex vivo mechanical testing along with partial thickness polypropylene suture (PR) as a control group (n = 40 for each group). Maximum pull-off forces were measured. All statistical tests were two-tailed, and a P-value < 0.05 was considered to be significant. RESULTS: The mean tenacity adhesion scores were 1.40 ± 0.52 (PF), 1.7 ± 0.82 (SF), and 2.6 ± 1.07 (TS). Adhesions in the PF group were significantly less tenacious compared with the TS group (P = 0.01). Quantitative adhesion scores were not significantly different among groups. The maximum pull-off forces, measured in Newtons, were 28.61 N ± 4.89 N (TS), 22.71 N ± 7.86 N (SF), 16.98 N ± 7.59 N (PF), and 20.83 N ± 6.25 N (PR). The pull-off force in the TS group was higher than all of the other groups (P < 0.001). The SF group also had a higher pull-off force compared with the PF group (P < 0.001). CONCLUSIONS: The screw-type absorbable and permanent fixation devices provided adequate fixation and were associated with decreased adhesions in this porcine model.

Cutaneous papillomatosis and carcinomatosis in the Western barred bandicoot (Perameles bougainville).

A progressive wart-like syndrome in both captive and wild populations of the Western barred bandicoot (WBB) is hindering conservation efforts to prevent the extinction of this endangered marsupial. In this study, 42 WBBs exhibiting the papillomatosis and carcinomatosis syndrome were examined. The disease was characterized by multicentric proliferative lesions involving cutaneous and mucosal surfaces, which were seen clinically to increase in size with time. Grossly and histologically the smaller skin lesions resembled papillomas, whereas the larger lesions were most commonly observed to be squamous cell carcinomas. Large amphophilic intranuclear inclusion bodies were observed in hyperplastic conjunctival lesions of 8 WBBs under light microscopy. Conjunctival lesions from 2 WBBs examined using transmission electron microscopy contained a crystalline array of spherical electron-dense particles of 45-nm diameter, within the nucleus of conjunctival epithelial cells, consistent with a papillomavirus or polyomavirus. Conjunctival samples from 3 bandicoots that contained intranuclear inclusion bodies also demonstrated a positive immunohistochemical reaction after indirect immunohistochemistry for papillomavirus structural antigens. Ultrastructural and/or immunohistochemical evidence of an etiologic agent was not identified in the nonconjunctival lesions examined. Here we describe the gross, histopathologic, ultrastructural, and immunohistochemical findings of a papillomatosis and carcinomatosis syndrome recently identified in the WBB.

Klossiella quimrensis (Apicomplexa: Klossiellidae) causes renal coccidiosis in western barred bandicoots Perameles bougainville (Marsupialia: Peramelidae) in Western Australia.

Previous studies have described a range of Klossiella species parasitic in marsupial hosts. Klossiella quimrensis is the etiologic agent of renal coccidiosis in the peramelid marsupial hosts Isoodon obesulus and Perameles gunnii in Eastern Australia, but there is no previous report of klossiellosis in Western Australian peramelids. This study describes klossiellosis diagnosed by histology of renal tissue sections collected during necropsy of 20 Perameles bougainville between 2000 and 2005. Sporonts, sporoblasts, and macrogametes were identified within parasitophorous vacuoles of epithelial cells located near the renal corticomedullary junction. The prevalence of renal coccidiosis in P. bougainville diagnosed by renal histology is estimated at 30%. Only a single unsporulated sporocyst was detected by examination of cystocentesis-collected urine, indicating that microscopic evaluation of urine samples is an insensitive diagnostic test for detection of K. quimrensis in P. bougainville. This infection in P. bougainville is indirectly associated with mild multifocal interstitial lymphohistiocytic nephritis and is likely to be only minimally pathogenic in otherwise healthy individuals. Our study also extends the host and geographic range of K. quimrensis to include P. bougainville and Western Australia.

Cryptosporidium muris infection in bilbies (Macrotis lagotis).

Cryptosporidiosis is an enteric disease of animals and humans that can be fatal in immunocompromised individuals. There is no known effective treatment for cryptosporidiosis. Bilbies are threatened marsupials and are bred in captivity as part of a recovery program to re-introduce this species to the southwest of Western Australia. Cryptosporidium muris infection was detected in the faeces of bilbies at a captive breeding colony. Stress associated with a high density of bilbies in enclosures may have predisposed some of the bilbies to infection with C. muris. C. muris has been described in mice and was found in the faeces of one mouse trapped in the breeding enclosures. It is likely the bilbies acquired the infection from mice by faecal contamination of food and water. The infection cleared within 2 months from some bilbies, however others remained infected for 6 months and treatment was attempted with dimetridazole. Subsequently the parasite was no longer be detectable in the faeces.

Speciation and intrasubspecific variation of Bornean orangutans, Pongo pygmaeus pygmaeus.

Mitochondrial DNA control region sequences of orangutans (Pongo pygmaeus) from six different populations on the island of Borneo were determined and analyzed for evidence of regional diversity and were compared separately with orangutans from the island of Sumatra. Within the Bornean population, four distinct subpopulations were identified. Furthermore, the results of this study revealed marked divergence, supportive evidence of speciation between Sumatran and Bornean orangutans. This study demonstrates that, as an entire population, Bornean orangutans have not experienced a serious genetic bottleneck, which has been suggested as the cause of low diversity in humans and east African chimpanzees. Based on these new data, it is estimated that Bornean and Sumatran orangutans diverged approximately 1.1 MYA and that the four distinct Bornean populations diverged 860,000 years ago. These findings have important implications for management, breeding, and reintroduction practices in orangutan conservation efforts.

Seasonal variation in glucocorticoid receptor binding characteristics in human mononuclear leucocytes.

OBJECTIVE: Glucocorticoid sensitivity varies between individuals and between tissues in the same individual. Although some of this variation is explained by the activity of the 11 beta-hydroxysteroid dehydrogenase enzymes, the possibility that glucocorticoid receptor sensitivity is modulated remains unexplored. This study examined glucocorticoid receptor binding in leucocytes and assessed the effects of seasonal hormonal variation on receptor binding. PATIENTS AND MEASUREMENTS: Two populations were studied. In the first, 318 healthy subjects were studied over 2 years with a single measurement of receptor binding made on each. In the second study nine healthy male subjects each had receptor binding measurements made at 3-week intervals over 1 year. RESULTS: In both populations there was significant seasonal variation in receptor binding. In the first population Kd for dexamethasone was highest in November and lowest in July (8.37 +/- 0.5 nmol/l vs. 1.58 +/- 0.7, mean +/- SEM P < 0.00001) and the number of receptor sites per leucocyte was highest in January and lowest in June (10 440 +/- 580 vs. 4969 +/- 302, P < 0.00001). In multivariate analysis, climate was the main determinant for both Kd and the number of receptor sites per cell: increases in day length and environmental temperature reduced Kd and the number of receptor sites per cell. Co-incubation with physiological concentrations of melatonin raised Kd without affecting receptor number. Co-incubation with forskolin lowered Kd suggesting that melatonin might act through the ML1 receptor class by inhibiting adenylyl cyclase. No correlations were found with 0900 h plasma cortisol. CONCLUSIONS: The results suggest that the glucocorticoid receptor might be modulated by season. Melatonin might mediate part of these effects. The lack of correlation with cortisol suggests that it is not an important determinant of receptor binding and that leucocyte receptors are regulated differently from central receptors.