Quantum Variational Solving of Nonlinear and Multi-Dimensional Partial Differential Equations

A variational quantum algorithm for numerically solving partial differential equations (PDEs) on a quantum computer was proposed by Lubasch et al. In this paper, we generalize the method introduced by Lubasch et al. to cover a broader class of nonlinear PDEs as well as multidimensional PDEs, and study the performance of the variational quantum algorithm on several example equations. Specifically, we show via numerical simulations that the algorithm can solve instances of the Single-Asset Black-Scholes equation with a nontrivial nonlinear volatility model, the Double-Asset Black-Scholes equation, the Buckmaster equation, and the deterministic Kardar-Parisi-Zhang equation. Our simulations used up to $n=12$ ansatz qubits, computing PDE solutions with $2^n$ grid points. We also performed proof-of-concept experiments with a trapped-ion quantum processor from IonQ, showing accurate computation of two representative expectation values needed for the calculation of a single timestep of the nonlinear Black--Scholes equation. Through our classical simulations and experiments on quantum hardware, we have identified -- and we discuss -- several open challenges for using quantum variational methods to solve PDEs in a regime with a large number ($\gg 2^{20}$) of grid points, but also a practical number of gates per circuit and circuit shots.Comment: 16 pages, 10 figures (main text

Comparison of long-term pregnancy outcomes between neosalpingostomy and salpingectomy for infertile women with bilateral severe hydrosalpinx

Objective·To compare the pregnancy outcomes of infertile women with bilateral severe hydrosalpinx receiving neosalpingostomy or salpingectomy.Methods·The single-center prospective cohort study from 2005 to 2012 focused on pregnancy outcomes of infertile women aged 20‒40 years, with bilateral severe hydrosalpinx, undergoing bilateral neosalpingostomy or salpingectomy in International Peace Maternal and Child Health Hospital, Shanghai Jiao Tong University School of Medicine. The choice for treatment was based on a shared decision approach, and the participants were divided into the neosalpingostomy group and salpingectomy group. After registration of baseline characteristics, including age, birth place, reproductive history, preoperative hysterosalpingography results, surgical findings, and pregnancy outcomes, women were followed up on an annual basis until July 2020 for the occurrence of live birth by outpatient follow-up or telephone questionnaire. Intention-to-treat analysis and per-protocol analysis were applied to compare the pregnancy outcomes. Kaplan-Meier analysis and COX proportional hazard model were used to analyze the reproductive outcomes. In addition, subgroup analysis was performed based on age stratification. The main outcome measures were live birth rate, cumulative live birth rate, and factors affecting live birth. Secondary outcome measures included the mode of conception, time to live birth, biochemical pregnancy rate, clinical miscarriage rate, and ectopic pregnancy rate.Results·A total of 113 women were included in the analysis, 58 women underwent bilateral neosalpingostomy, and 55 women underwent bilateral salpingectomy. The study demonstrated that in infertile women with bilateral severe hydrosalpinx, bilateral salpingectomy achieved higher cumulative live birth rate than bilateral neosalpingostomy (76.36% vs 62.07, HR=2.18,95%CI 1.37‒3.45). In the neosalpingostomy group, 34.48% (20/58) live births were obtained after in vitro fertilization treatment, and 27.59% (16/58) live births were obtained through spontaneous conception which mainly occurred within 3 years after initial neosalpingostomy, while all live births in the salpingectomy group were obtained after assisted reproductive therapy. However, the risk of ectopic pregnancy was higher in the neosalpingostomy group than that in the salpingectomy group (20.69% vs 1.82%, P<0.001). No statistically significant differences regarding biochemical pregnancy and clinical miscarriage between the two groups were found. During the subgroup analysis, the cumulative live birth rate of the salpingectomy group (n=51) was significantly higher than that of the neosalpingostomy group (n=48) in women younger than 35 years old (HR=2.25, 95%CI 1.39‒3.66), while between two groups of women aged 35 years old or older, there was no statistically significant difference in the cumulative live birth rate (HR=1.60, 95%CI 0.36‒7.19). In addition, after adjustment for confounding factors including age, previous abortion history, fibroid, benign ovarian cyst, and endometriosis, COX proportional hazard analysis revealed that salpingectomy was positively correlated to live birth compared with neosalpingostomy (aHR=1.94, 95%CI 1.18‒3.18).Conclusion·For infertile women with bilateral severe hydrosalpinx, neosalpingostomy provides the possibility for spontaneous conception but also brings about certain risk of ectopic pregnancy. Bilateral salpingectomy can achieve higher cumulative live birth rate while receiving postoperative in vitro fertilization treatment

RobustState: Boosting Fidelity of Quantum State Preparation via Noise-Aware Variational Training

Quantum state preparation, a crucial subroutine in quantum computing, involves generating a target quantum state from initialized qubits. Arbitrary state preparation algorithms can be broadly categorized into arithmetic decomposition (AD) and variational quantum state preparation (VQSP). AD employs a predefined procedure to decompose the target state into a series of gates, whereas VQSP iteratively tunes ansatz parameters to approximate target state. VQSP is particularly apt for Noisy-Intermediate Scale Quantum (NISQ) machines due to its shorter circuits. However, achieving noise-robust parameter optimization still remains challenging. We present RobustState, a novel VQSP training methodology that combines high robustness with high training efficiency. The core idea involves utilizing measurement outcomes from real machines to perform back-propagation through classical simulators, thus incorporating real quantum noise into gradient calculations. RobustState serves as a versatile, plug-and-play technique applicable for training parameters from scratch or fine-tuning existing parameters to enhance fidelity on target machines. It is adaptable to various ansatzes at both gate and pulse levels and can even benefit other variational algorithms, such as variational unitary synthesis. Comprehensive evaluation of RobustState on state preparation tasks for 4 distinct quantum algorithms using 10 real quantum machines demonstrates a coherent error reduction of up to 7.1 $\times$ and state fidelity improvement of up to 96\% and 81\% for 4-Q and 5-Q states, respectively. On average, RobustState improves fidelity by 50\% and 72\% for 4-Q and 5-Q states compared to baseline approaches.Comment: Accepted to FASTML @ ICCAD 2023. 14 pages, 20 figure

Zebrafish Whole-Adult-Organism Chemogenomics for Large-Scale Predictive and Discovery Chemical Biology

The ability to perform large-scale, expression-based chemogenomics on whole adult organisms, as in invertebrate models (worm and fly), is highly desirable for a vertebrate model but its feasibility and potential has not been demonstrated. We performed expression-based chemogenomics on the whole adult organism of a vertebrate model, the zebrafish, and demonstrated its potential for large-scale predictive and discovery chemical biology. Focusing on two classes of compounds with wide implications to human health, polycyclic (halogenated) aromatic hydrocarbons [P(H)AHs] and estrogenic compounds (ECs), we generated robust prediction models that can discriminate compounds of the same class from those of different classes in two large independent experiments. The robust expression signatures led to the identification of biomarkers for potent aryl hydrocarbon receptor (AHR) and estrogen receptor (ER) agonists, respectively, and were validated in multiple targeted tissues. Knowledge-based data mining of human homologs of zebrafish genes revealed highly conserved chemical-induced biological responses/effects, health risks, and novel biological insights associated with AHR and ER that could be inferred to humans. Thus, our study presents an effective, high-throughput strategy of capturing molecular snapshots of chemical-induced biological states of a whole adult vertebrate that provides information on biomarkers of effects, deregulated signaling pathways, and possible affected biological functions, perturbed physiological systems, and increased health risks. These findings place zebrafish in a strategic position to bridge the wide gap between cell-based and rodent models in chemogenomics research and applications, especially in preclinical drug discovery and toxicology

Impact of Land-Use Change on Ecosystem Services in the Wuling Mountains from a Transport Development Perspective

Transportation significantly affects regional land-use changes and ecosystem service functions. Exploring the correlations among transport development, spatial pattern of land-use changes, and ecosystem service changes are important for mitigating the deterioration of regional ecosystems due to human activities. In this study, 2000–2020 was selected as the study period to explore the effects of land-use changes on the ecosystem service value (ESV) in the Wuling Mountains. The results showed that: (1) the Wuling Mountains have experienced four stages of transport development and (2) transportation development has contributed to land-use change. The spatial pattern associated with construction land growth has evolved due to transport development. Garden land has gradually spread into the entire region with transport development. Policies from different periods have had more of an effect on ecological land and cropland. (3) During the study period, the ESV first increased and then declined. The periphery of the transportation axis formed a concentration zone of ESV cold spots. In contrast, ESV hot spots were more concentrated in areas along the Yangtze River. The results of this study provide guidance for land-use policy and spatial planning under the concept of green development

Characterization and Manipulation of Carbon Precursor Species during Plasma Enhanced Chemical Vapor Deposition of Graphene

To develop a synthesis technique providing enhanced control of graphene film quality and uniformity, a systematic characterization and manipulation of hydrocarbon precursors generated during plasma enhanced chemical vapor deposition of graphene is presented. Remote ionization of acetylene is observed to generate a variety of neutral and ionized hydrocarbon precursors, while in situ manipulation of the size and reactivity of carbon species permitted to interact with the growth catalyst enables control of the resultant graphene morphology. Selective screening of high energy hydrocarbon ions coupled with a multistage bias growth regime results in the production of 90% few-to-monolayer graphene on 50 nm Ni/Cu alloy catalysts at 500 C. Additionally, synthesis with low power secondary ionization processes is performed and reveals further control during the growth, enabling a 50% reduction in average defect densities throughout the film. Mass spectrometry and UV-Vis spectroscopy monitoring of the reaction environment in conjunction with Raman characterization of the synthesized graphene films facilitates correlation of the carbon species permitted to reach the catalyst surface to the ultimate quality, layer number, and uniformity of the graphene film. These findings reveal a robust technique to control graphene synthesis pathways during plasma enhanced chemical vapor deposition

Spatial Pattern of Large-Scale Agricultural Land and Spatial Heterogeneity of Influencing Factors in the Mountainous Areas of Western China—Wuling Mountains as an Example

The scaling of agricultural land is a trend in land use transformation and is important for modernizing agriculture. Therefore, the reasons for large-scale agricultural land formation should be explored. The spatial distribution of large-scale agricultural land and the factors for its formation vary between different regions. Currently, the exploration of the formation mechanism of large-scale agricultural land from the perspective of heterogeneity is not yet sufficient. Therefore, the main objectives of this article are as follows: first, analyze the spatial pattern characteristics of large-scale agricultural land; second, explore the spatial heterogeneity characteristics of influencing factors from both global and local perspectives; third, explore the mechanism of the formation of large-scale agricultural land from the perspective of heterogeneity. The results indicate the following: (1) The large-scale agricultural land distribution pattern in the Wuling Mountains area was high in the east and low in the west. (2) Natural conditions, production factors, and location conditions all significantly impacted large-scale agricultural land, but with differences in their degree of influence. From a local perspective, the influences of various factors in different regions also exhibited spatial heterogeneity. These two types of heterogeneity can be attributed to the differences in regional development stages. (3) Natural conditions, location conditions, and production factors had negative, positive, and positive effects on the agricultural land scale, respectively, but the influence of the first two decreased with the improvement in the regional development stages. The influence of different factors on production factors was related to the regional development stage, and production factors that were suitable for the regional development stage had a greater impact. The conclusion can provide differentiated policy support for regional land use in practice

The complete mitochondrial genome of diamond dove (Geopelia cuneata) and its phylogeny

The complete mitochondrial genome (mitogenome) of diamond dove (Geopelia cuneata) was first determined in this study. The mitogenome is 17,880 bp in size and composed of 22 transfer RNA genes, 13 protein-coding genes, two ribosomal RNA genes, and a control region. The overall nucleotide composition is 30.11% of A, 13.66% of G, 25.11% of T, and 31.13% of C. The mitochondrial structure and gene order were similar to other Columbidae species. Phylogenetic analysis suggested that G. cuneata was placed as sister to G. striata of the same genus. The data could provide valuable information for further studies on conservation genetics and evolution of G. cuneata

Characterization and Manipulation of Carbon Precursor Species during Plasma Enhanced Chemical Vapor Deposition of Graphene

To develop a synthesis technique providing enhanced control of graphene film quality and uniformity, a systematic characterization and manipulation of hydrocarbon precursors generated during plasma enhanced chemical vapor deposition of graphene is presented. Remote ionization of acetylene is observed to generate a variety of neutral and ionized hydrocarbon precursors, while in situ manipulation of the size and reactivity of carbon species permitted to interact with the growth catalyst enables control of the resultant graphene morphology. Selective screening of high energy hydrocarbon ions coupled with a multistage bias growth regime results in the production of 90% few-to-monolayer graphene on 50 nm Ni/Cu alloy catalysts at 500 &deg;C. Additionally, synthesis with low power secondary ionization processes is performed and reveals further control during the growth, enabling a 50% reduction in average defect densities throughout the film. Mass spectrometry and UV-Vis spectroscopy monitoring of the reaction environment in conjunction with Raman characterization of the synthesized graphene films facilitates correlation of the carbon species permitted to reach the catalyst surface to the ultimate quality, layer number, and uniformity of the graphene film. These findings reveal a robust technique to control graphene synthesis pathways during plasma enhanced chemical vapor deposition