Non-Hermitian quantum dynamics and entanglement of coupled nonlinear resonators

We consider a generalization of recently proposed non-Hermitian model for resonant cavities coupled by a chiral mirror by taking into account number non-conservation and nonlinear interactions. We analyze non-Hermitian quantum dynamics of populations and entanglement of the cavity modes. We find that an interplay of initial coherence and non-Hermitian coupling leads to a counterintuitive population transfer. While an initially coherent cavity mode is depleted, the other empty cavity can be populated more or less than the initially filled one. Moreover, presence of nonlinearity yields population collapse and revival as well as bipartite entanglement of the cavity modes. In addition to coupled cavities, we point out that similar models can be found in $\mathcal{PT}$ symmetric Bose-Hubbard dimers of Bose-Einstein condensates or in coupled soliton-plasmon waveguides. We specifically illustrate quantum dynamics of populations and entanglement in a heuristic model that we propose for a soliton-plasmon system with soliton amplitude dependent asymmetric interaction. Degree of asymmetry, nonlinearity and coherence are examined to control plasmon excitations and soliton-plasmon entanglement. Relations to $\mathcal{PT}$ symmetric lasers and Jahn-Teller systems are pointed out

Isolated Ramp Metering Feedback Control Utilizing Mixed Sensitivity for Desired Mainline Density and the Ramp Queues

This paper presents a feedback control design for isolated ramp metering control. This feedback control design, unlike the existing isolated feedback ramp controllers, also takes into account the ramp queue length. Using a nonlinear H∞ control design methodology, we formulate the problem in the desired setting to be able to utilize the results of the methodology

Evaluation of boldness assays and associated behavioral measures in a social parrot, monk parakeet (\u3ci\u3eMyiopsitta monachus\u3c/i\u3e)

Boldness reflects consistent individual differences in risk-taking behavior across various contexts. However, evaluating this basic assumption has largely been neglected in birds. In a captive monk parakeet population (Myiopsitta monachus; N = 33), we undertook an analysis of 7 measures across 3 commonly used boldness assays (i.e., novel object, emergence, and predator-exposure tests). Using principal component analysis, we derived 3 components (PCs). PC-2 loaded strongly with measures from emergence and predator-exposure tests; we interpreted it as the closest approximation of boldness. PC-1 and PC-3 described different aspects of feeding such as foraging activity and rate, respectively. Finally, we assessed the predictive power of each measure that loaded significantly on the boldness axis.We found that no single metric explained even %55 of the variation in PC-2, nor could more than %50 individuals at the extremes of the spectrum be predicted. Our results demonstrate the utility of an inclusive approach in personality research

Social conformity affects experimental measurement of boldness in male but not female monk parakeets (\u3ci\u3eMyiopsitta monachus\u3c/i\u3e)

The standard approach for characterizing boldness rarely considers the influence of social environment on the expression of boldness in group-living animals. We studied a wild-caught, captive population of monk parakeets (Myiopsitta monachus) to investigate the impact of conspecific presence on boldness — a personality trait in monk parakeets — in a controlled environment. We quantified seven boldness metrics across three types of behavioural assay: novel object, emergence, and predator exposure tests in the presence of a companion pair of flock mates. Because of the high degree of sociality in this species, we hypothesized that the presence of companion birds would facilitate the focal individuals’ behavioural responses (i.e., increase the average boldness level). We found that behavioural response in a risky foraging context was inversely correlated between solitary and social condition in males, but not in females. Our results have implications for characterizing sex-specific differences of risk-taking behaviour in social animals

Effectiveness of social egg freezing: Protocol for systematic review and meta-analyses

© 2019 Author(s). Introduction Social egg freezing is storing egg for the purpose of preserving fertility and delayed childbearing. Currently, little is known about the utilisation and effectiveness of this approach. This review aims to determine (1) the proportion of women who used their stored eggs, and (2) the egg survival rate through vitrification, and the clinical pregnancy rate and live birth rate per 100 women partaking in the procedure, and among women who stored their eggs for medical reasons. Methods and analyses This systematic review will be done according to the items listed in the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement. PubMed, Embase, Scopus, The Cumulative Index to Nursing and Allied Health Literature (CINAHL) and the Cochrane Library and Health Technology Assessment databases will be searched to identify eligible studies published since 2012. Two reviewers will independently appraise the eligibility and quality of the studies based on preset checklists and extract the data using a data extraction template. Outcomes of interest are proportion of women who used their stored eggs, egg survival rate, pregnancy rate and live birth rates. We will determine the presence heterogeneity among studies using the Cochrane's Q test. The percentage of total variation across studies, which is due to statistical heterogeneity, will be calculated using the I 2 statistics. Outcomes of interest will be pooled together using metaprop programme STATA V.14. Ethics and dissemination For this review, ethical committee approval is not required. We will use publically available data from previously published studies. The final report of the review will be disseminated through publication on national or international journal, and it will be presented on different scientific conferences

A study of the Czernik 2 and NGC 7654 open clusters using CCD UBV photometric and Gaia EDR3 data

We analysed the open clusters Czernik 2 and NGC 7654 using CCD UBV photometric and Gaia Early Data Release 3 (EDR3) photometric and astrometric data. Structural parameters of the two clusters were derived, including the physical sizes of Czernik 2 being r=5 and NGC 7654 as 8 min. We calculated membership probabilities of stars based on their proper motion components as released in the Gaia EDR3. To identify member stars of the clusters, we used these membership probabilities taking into account location and the impact of binarity on main-sequence stars. We used membership probabilities higher than $P=0.5$ to identify 28 member stars for Czernik 2 and 369 for NGC 7654. We estimated colour-excesses and metallicities separately using two-colour diagrams to derive homogeneously determined parameters. The derived $E(B-V)$ colour excess is 0.46(0.02) mag for Czernik 2 and 0.57(0.04) mag for NGC 7654. Metallicities were obtained for the first time for both clusters, -0.08(0.02) dex for Czernik 2 and -0.05(0.01) dex for NGC 7654. Keeping the reddening and metallicity as constant quantities, we fitted PARSEC models using colour-magnitude diagrams, resulting in estimated distance moduli and ages of the two clusters. We obtained the distance modulus for Czernik 2 as 12.80(0.07) mag and for NGC 7654 as 13.20(0.16) mag, which coincide with ages of 1.2(0.2) Gyr and 120(20) Myr, respectively. The distances to the clusters were calculated using the Gaia EDR3 trigonometric parallaxes and compared with the literature. We found good agreement between the distances obtained in this study and the literature. Present day mass function slopes for both clusters are comparable with the value of Salpeter (1955), being X=-1.37(0.24) for Czernik 2 and X=-1.39(0.19) for NGC 7654.Comment: 22 pages, 13 figures and 9 tables, accepted for publication in Astrophysics and Space Scienc

Site characteristics determine the effectiveness of tillage and cover crops on the net ecosystem carbon balance in California vineyard agroecosystems

Globally, wine grape vineyards cover approximately 7.4 M ha. The potential for carbon (C) storage in vineyards is of great interest to offset greenhouse gas emissions and mitigate the effects of climate change. Sustainable soil management practices such as cover crop adoption and reduced tillage may contribute to soil organic carbon (SOC) sequestration. However, site-specific factors such as soil texture, other soil physicochemical properties, and climate largely influence the range and rate to which SOC may be stored. To measure the potential for C storage in vineyards under varying sustainable soil management practices, we calculated the net ecosystem carbon balance (NECB) of three cover crops [perennial grass (Poa bulbosa hybrid cv. Oakville Blue); annual grass (barley, Hordeum vulgare); resident vegetation (natural weed population)] under conventional tillage (CT) and no-till (NT) management. Results provided evidence that vineyards served as C sinks. In sandy soils, the type of cover crop and tillage may be of little influence on the NECB. While in finer-textured soils, tillage reduced the NECB and higher biomass-producing cover crops enhanced the overall C storage potential of the vineyard agroecosystem. Overall, our results revealed that site characteristics, namely, soil texture and climate, were key determinants of the C storage potential of vineyards in Mediterranean climates such as those found in coastal and inland California wine grape production regions