Fluctuations and Non-Hermiticity in the Stochastic Approach to Quantum Spins

We investigate the non-equilibrium dynamics of isolated quantum spin systems via an exact mapping to classical stochastic differential equations. We show that one can address significantly larger system sizes than recently obtained, including two-dimensional systems with up to 49 spins. We demonstrate that the results for physical observables are in excellent agreement with exact results and alternative numerical techniques where available. We further develop a hybrid stochastic approach involving matrix product states. In the presence of finite numerical sampling, we show that the non-Hermitian character of the stochastic representation leads to the growth of the norm of the time-evolving quantum state and to departures for physical observables at late times. We demonstrate approaches that correct for this and discuss the prospects for further development.Comment: 5 pages, 4 figures, Supplementary Materia

Trajectory-Resolved Weiss Fields for Quantum Spin Dynamics

We explore the dynamics of quantum spin systems in two and three dimensions using an exact mapping to classical stochastic processes. In recent work we explored the effectiveness of sampling around the mean field evolution as determined by a stochastically averaged Weiss field. Here, we show that this approach can be significantly extended by sampling around the instantaneous Weiss field associated with each stochastic trajectory taken separately. This trajectory-resolved approach incorporates sample to sample fluctuations and allows for longer simulation times. We demonstrate the utility of this approach for quenches in the two-dimensional and three-dimensional quantum Ising model. We show that the method is particularly advantageous in situations where the average Weiss-field vanishes, but the trajectory-resolved Weiss fields are non-zero. We discuss the connection to the gauge-P phase space approach, where the trajectory-resolved Weiss field can be interpreted as a gauge degree of freedom.Comment: 11 pages, 7 figure

Use of ERTS-1 data in identification, classification, and mapping of salt-affected soils in California

There are no author-identified significant results in this report

Meratran: An Assessment of a New Central Stimulant in Psychiatry

Abstract Not Provided

A Metastasis or a Second Independent Cancer? Evaluating the Clonal Origin of Tumors Using Array-CGH Data

When a cancer patient develops a new tumor it is necessary to determine if this is a recurrence (metastasis) of the original cancer, or an entirely new occurrence of the disease. This is accomplished by assessing the histo-pathology of the lesions, and it is frequently relatively straightforward. However, there are many clinical scenarios in which this pathological diagnosis is difficult. Since each tumor is characterized by a genetic fingerprint of somatic mutations, a more definitive diagnosis is possible in principle in these difficult clinical scenarios by comparing the fingerprints. In this article we develop and evaluate a statistical strategy for this comparison when the data are derived from array comparative genomic hybridization, a technique designed to identify all of the somatic allelic gains and losses across the genome. Our method involves several stages. First a segmentation algorithm is used to estimate the regions of allelic gain and loss. Then the broad correlation in these patterns between the two tumors is assessed, leading to an initial likelihood ratio for the two diagnoses. This is then further refined by comparing in detail each plausibly clonal mutation within individual chromosome arms, and the results are aggregated to determine a final likelihood ratio. The method is employed to diagnose patients from several clinical scenarios, and the results show that in many cases a strong clonal signal emerges, occasionally contradicting the clinical diagnosis. The “quality” of the arrays can be summarized by a parameter that characterizes the clarity with which allelic changes are detected. Sensitivity analyses show that most of the diagnoses are robust when the data are of high quality

Stress patterns around distal angled implants in the all-on-four concept configuration

nonePurpose: The All-on-Four concept advocates immediate loading and the placement of distal implants at an angle. The purpose of this study was to do a qualitative descriptive analysis of stress patterns around the distal angled implant of the All-on-Four concept. Materials and Methods: Four photoelastic acrylic resin models, each with four implants simulating the All-on-Four configuration, were prepared. The two central implants were placed vertically and parallel in each model, and the distal implant on each side was placed at an increasing angle (0, 15, 30, and 45 degrees) in each model. The four implants were splinted by means of a cast metal bar. The photoelastic models were placed between two parallel anvils. Pairs of abutments were systematically subjected to a load by suspending 5-, 10-, and 15-kg weights from one of the anvils. Photoelastic analysis was accomplished using a circular polariscope. The fringe patterns produced in the photoelastic resin for each implant and load were photographed with a digital camera. Fringe concentrations and the highest fringe order were recorded and described for the apical, central, and coronal regions of the distal angled implant for each load scenario. Results: For the implants placed at 15- and 30-degree angles, little difference in stress patterns was observed between the central straight implant and the distal angled implant. For every load scenario and for all angulations, the lowest fringe order was recorded at the central region of the implant. The highest fringe order for the apical region was always higher than the highest fringe order for the coronal region of the implant. Markedly increased isochromatic fringe concentrations were observed in model 4, which had the distal implants placed at a 45-degree angle. Conclusion: Periimplant bone surrounding the 45-degree-angled distal abutment may be more prone to occlusal overload than bone surrounding implants with lesser tilts.non

The primary structure of three hemoglobin chains from the indigo snake (Drymarchon corais erebennus, Serpentes): First evidence for αD chains and two β chain types in snakes

The hemoglobin of the indigo snake (Drymarchon corais erebennus, Colubrinae) consists of two components, HbA and HbD, in the ratio of 1:1. They differ in both their alpha and beta chains. The amino acid sequences of both alpha chains (alpha(A) and alpha(D)) and one beta chain (betaI) were determined. The presence of an alpha(D)chain in a snake hemoglobin is described for the first time. A comparison of all snake beta chain sequences revealed the existence of two paralogous beta chain types in snakes as well, which are designated as betaI and betaII type. For the discussion of the physiological properties of Drymarchon hemoglobin, the sequences were compared with those of the human alpha and beta chains and those of the closely related water snake Liophis miliaris where functional data are available. Among the heme contacts, the substitution alpha(D)58(E7)His-->Gln is unusual but most likely without any effect. The residues responsible for the main part of the Bohr effect are the same as in mammalian hemoglobins. In each of the three globin chains only two residues at positions involved in the alpha1/beta2 interface contacts, most important for the stability and the properties of the hemoglobin molecule, are substituted with regard to human hemoglobin. On the contrary, nine, eleven, and six alpha1/beta1 contact residues are replaced in the alpha(A), alpha(D), betaI chains, respectively

Citizen science and farmer-led innovation at the frontiers of farming and biodiversity

Agriculture is a key frontier for ensuring planetary health and conserving and promoting biodiversity. The EU project “FRAMEwork” (2020-2024) is helping farmer groups, so-called ‘farmer clusters’, with a shared interest in monitoring biodiversity on their farms in partnership with researchers and local communities as well as implementing more biodiversity-friendly farming at a landscape scale. In eleven active farmer clusters from Spain to Estonia, the project is combining two concepts, stemming from different practice domains: Farmer Clusters and Citizen Observatories. The combination of the two concepts aims to maximise the strengths of both and create a strong, evidence-based, locally embedded community approach to biodiversity protection and enhancement by enabling the integration of structured monitoring with adaptive land management practices. In this poster, we present a summary of the approach including different pathways to link farmer-led innovation via farmer clusters at a landscape scale with the Citizen Observatory concept as well as some intermediary results of the project

The Waipounamu Erosion Surface: questioning the antiquity of the New Zealand land surface and terrestrial fauna and flora

The Waipounamu Erosion Surface is a time-transgressive, nearly planar, wave-cut surface. It is not a peneplain. Formation of the Waipounamu Erosion Surface began in Late Cretaceous time following break-up of Gondwanaland, and continued until earliest Miocene time, during a 60 million year period of widespread tectonic quiescence, thermal subsidence and marine transgression. Sedimentary facies and geomorphological evidence suggest that the erosion surface may have eventually covered the New Zealand subcontinent (Zealandia). We can find no geological evidence to indicate that land areas were continuously present throughout the middle Cenozoic. Important implications of this conclusion are: (1) the New Zealand subcontinent was largely, or entirely, submerged and (2) New Zealand's present terrestrial fauna and flora evolved largely from fortuitous arrivals during the past 22 million years. Thus the modern terrestrial biota may not be descended from archaic ancestors residing on Zealandia when it broke away from Gondwanaland in the Cretaceous, since the terrestrial biota would have been extinguished if this landmass was submerged in Oligocene–Early Miocene time. We conclude that there is insufficient geological basis for assuming that land was continuously present in the New Zealand region through Oligocene to Early Miocene time, and we therefore contemplate the alternative possibility, complete submergence of Zealandia