Low dimensional manifolds for exact representation of open quantum systems

Weakly nonlinear degrees of freedom in dissipative quantum systems tend to localize near manifolds of quasi-classical states. We present a family of analytical and computational methods for deriving optimal unitary model transformations based on representations of finite dimensional Lie groups. The transformations are optimal in that they minimize the quantum relative entropy distance between a given state and the quasi-classical manifold. This naturally splits the description of quantum states into quasi-classical coordinates that specify the nearest quasi-classical state and a transformed quantum state that can be represented in fewer basis levels. We derive coupled equations of motion for the coordinates and the transformed state and demonstrate how this can be exploited for efficient numerical simulation. Our optimization objective naturally quantifies the non-classicality of states occurring in some given open system dynamics. This allows us to compare the intrinsic complexity of different open quantum systems.Comment: Added section on semi-classical SR-latch, added summary of method, revised structure of manuscrip

99mTc-EDDA/HYNIC-TOC in management of patients with head and neck somatostatin receptor positive tumors

BACKGROUND: Aim of this study was to determine the value of technetium-99m-hydrazinonicotinyl-Tyr3-octreotide (99mTc-ED­DA/HYNIC-TOC) in patients with somatostatin receptor (SSR) positive tumors of head and neck region. MATERIAL AND METHODS: A total number of 16 patients were enrolled in this study. Planar whole body (WB) and single photon emission computed tomography (SPECT) images were acquired at 2 and 4 hours after the injection of approximately 670 MBq of 99mTc-EDDA/HYNIC-TOC. Additional single photon emission computed tomography/computed tomography (SPECT/CT) images of the head and neck region were acquired at 4h post tracer injection. Clinical and imaging follow up were taken as the reference standard. RESULTS: There were 10 female and 6 male patients of age 57.7 ± 12.9 years (58.5; 32–78) years. 99mTc-EDDA/HYNIC-TOC somatostatin receptor scintigraphy (SRS) was TP in 13 patients, TN in two and FP in one. Follow up period for SRS was 31.1 ± 19.4 (29; 2–63) months. 99mTc-EDDA/HYNIC-TOC scintigraphy provided additional information in 50% of patients, with impact on patient management in the same percentage of patients. Distant metastases were found in nine out of 16 patients (56%). 99mTc-EDDA/HYNIC-TOC SRS had sensitivity of 100% (75.3–100%), specificity of 66.7% (9.4–99.2%), accuracy of 93.7%, positive predictive value of 92.9% (66.1–99.8%), and negative predictive value of 100% (15.8–100%). CONCLUSION: Somatostatin receptor scintigraphy using 99mTc-EDDA/HYNIC-TOC is very useful imaging method in the evalu­ation of patients with SSR positive tumors of head and neck region

The Influence of Nonextensivity on Orientational Ordering in Liquid Crystal Systems with Variable Molecular Shape

A generalized model taking into account the photoisomerization influence on the nematic ordering is presented. This generalized theory is used to investigate the effect of the nonextensivity on the concentration dependence of the long-range order parameter. The q-dependent variation of the concentration of cis-trans isomers and of the order parameter with the time of exposure to the illumination is investigated within nonextensivity. It is also shown that for sufficiently long exposition of the mesophase to the illumination the nematic phase cannot disappear for some value of the entropic index, coming from Tsallis statistics. Moreover it is shown that long range interactions or the fractal structure in the liquid crystalline system might affect the characteristics of the phase transition in the physical system. We think therefore that this conclusion might shed light on the interaction potential energy terms in the similar system in future possible experiments, even to be performed on new objects with different symmetries.Comment: 18 pages together with 5 figures. Accepted for publication in Physica

Blue Carbon in Marine Protected Areas: Part 2

Coastal and marine ecosystems play a significant role in the global carbon cycle, sequestering and storing carbon over long timescales. These "blue carbon" ecosystems help mitigate climate change and its impacts by facilitating the uptake of atmospheric carbon dioxide (CO2) into the ocean and transporting carbon into sediments or deep waters where it can remain indefinitely if undisturbed. Inclusion of these coastal and ocean processes as part of the solution to global climate change is essential in achieving global carbon mitigation and emission reduction goals; however, blue carbon is often overlooked in climate mitigation policies. Further, resource managers of the largest network of U.S. marine protected areas (MPAs), the Office of National Marine Sanctuaries, have not incorporated assessments of blue carbon extent and functionality into their management plans, policies, or decisions, which can result in unintentional carbon emissions and lost opportunities to further protect and enhance carbon sequestration in MPAs. Though blue carbon is a rapidly growing area of research, guidance for how to apply blue carbon information in MPA management is lacking, and for some sequestration processes, completely absent. As requested by Greater Farallones National Marine Sanctuary (GFNMS) in response to Part 1 of this series, the Greater Farallones Association conducted a blue carbon assessment for the sanctuary. This is the first assessment of multiple blue carbon sequestration processes in a U.S. federal MPA, with the primary purpose of informing one of the nation's largest MPAs in its management decision-making. The carbon storage and annual sequestration for two coastal blue carbon habitats, seagrass and salt marsh, and two oceanic carbon sequestration processes, kelp export and dead whale falls, were assessed within the boundaries of the sanctuary using regional and site-specific data. These processes have the potential to sequester 4,950 megagrams of carbon (MgC) each year (or 18,150 metric tons CO2 equivalent), which is valued at $925,650 in societal benefit annually and is 140 times the amount of CO2 that is emitted from annual site operations. Whale falls account for roughly 60% of this annual sequestration; salt marsh, seagrass, and kelp account for roughly equal parts of the remaining 40%, though annual sequestration by the region's kelp forests have declined by 99.7% from 2008 to 2019. Sanctuary coastal blue carbon habitats currently hold approximately 175,000 MgC in their sediments, which, if destroyed, could release approximately 643,000 metric tons of CO2, or the equivalent of adding 140,000 vehicles to the road for one year. Understanding carbon sequestration within national marine sanctuaries is key for managing changes to stored carbon, which has national and global climate relevance. While these estimates are an incomplete characterization of carbon services provided by GFNMS, this report nonetheless serves as a preliminary step in guiding sanctuary management to protect and enhance the critical climate mitigation services of its coast and ocean resources

Specification of photonic circuits using Quantum Hardware Description Language

Following the simple observation that the interconnection of a set of quantum optical input-output devices can be specified using structural mode VHSIC Hardware Description Language (VHDL), we demonstrate a computer-aided schematic capture workflow for modeling and simulating multi-component photonic circuits. We describe an algorithm for parsing circuit descriptions to derive quantum equations of motion, illustrate our approach using simple examples based on linear and cavity-nonlinear optical components, and demonstrate a computational approach to hierarchical model reduction.Comment: 20 pages, 6 figures, 1 table, 6 code listing