Improving Hyperspectral Subpixel Target Detection Using Hybrid Detection Space

A Hyper-Spectral Image (HSI) has high spectral and low spatial resolution. As a result, most targets exist as subpixels, which pose challenges in target detection. Moreover, limitation of target and background samples always hinders the target detection performance. In this thesis, a hybrid method for subpixel target detection of an HSI using minimal prior knowledge is developed. The Matched Filter (MF) and Adaptive Cosine Estimator (ACE) are two popular algorithms in HSI target detection. They have different advantages in differentiating target from background. In the proposed method, the scores of MF and ACE algorithms are used to construct a hybrid detection space. First, some high abundance target spectra are randomly picked from the scene to perform initial detection to determine the target and background subsets. Then, the reference target spectrum and background covariance matrix are improved iteratively, using the hybrid detection space. As the iterations continue, the reference target spectrum gets closer and closer to the central line that connects the centers of target and background and resulting in noticeable improvement in target detection. Two synthetic datasets and two real datasets are used in the experiments. The results are evaluated based on the mean detection rate, Receiver Operating Characteristic (ROC) curve and observation of the detection results. Compared to traditional MF and ACE algorithms with Reed-Xiaoli Detector (RXD) background covariance matrix estimation, the new method shows much better performance on all four datasets. This method can be applied in environmental monitoring, mineral detection, as well as oceanography and forestry reconnaissance to search for extremely small target distribution in a large scene

Densification of Ultra-Refractory Transition Metal Diboride Ceramics

The densification behavior of transition metal diboride compounds was reviewed with emphasis on ZrB2 and HfB2. These compounds are considered ultra-high temperature ceramics because they have melting temperatures above 3000°C. Densification of transition metal diborides is difficult due to their strong covalent bonding, which results in extremely high melting temperatures and low self-diffusion coefficients. In addition, oxide impurities present on the surface of powder particles promotes coarsening, which further inhibits densification. Studies prior to the 1990s predominantly used hot pressing for densification. Those reports revealed densification mechanisms and identified that oxygen impurity contents below about 0.5 wt% were required for effective densification. Subsequent studies have employed advanced sintering methods such as spark plasma sintering and reactive hot pressing to produce materials with nearly full density and higher metallic purity. Further studies are needed to identify fundamental densification mechanisms and further improve the elevated temperature properties of transition metal diborides

Onset of a boson mode at superconducting critical point of underdoped YBa2Cu3Oy

The thermal conductivity $\kappa$ of underdoped \Y was measured in the $T \to 0$ limit as a function of hole concentration $p$ across the superconducting critical point at $p_{SC}$ = 5.0%. ``Time doping'' was used to resolve the evolution of bosonic and fermionic contributions with high accuracy. For $p \leqslant p_{SC}$, we observe an additional $T^3$ contribution to $\kappa$ which we attribute to the boson excitations of a phase with long-range spin or charge order. Fermionic transport, manifest as a linear term in $\kappa$, is seen to persist unaltered through $p_{SC}$, showing that the state just below $p_{SC}$ is a thermal metal. In this state, the electrical resistivity varies as log$(1/T)$ and the Wiedemann-Franz law is violated

Effects of Tillage and Residue Management on Soil Organic Carbon and Total Nitrogen in the North China Plain

Chinese Academy of Sciences XDA050500001 KSCX1-YW-09-06;Ministry of Science and Technology of China 2004CB720501A suitable tillage-residue management system is needed in the North China Plain (NCP) that sustains soil fertility and agronomic productivity. The objectives of this study were to determine the effects of different tillage-residue managements for a winter wheat (Triticum aestivum L.) and summer maize (Zea mays L.) double-crop system on soil organic carbon (SOC) and total N pools. No-tillage with residue cover (NTR), no-tillage with residue removed and manure applied (NTRRM), and conventional tillage with residue removed (CTRR) were investigated for 6 yr, based on a uniform N application among treatments. Soil samples were collected at six depths and changes in SOC and total N pools were analyzed. Treatments of NTRRM and NTR sequestered more SOC and total N in the 0- to 5-cm depth than CTRR. In the subsoil (5-60 cm), annual SOC sequestration was 0.01 and -0.40 Mg ha(-1) yr(-1) for NTRRM and NTR, respectively, while CTRR exhibited a significantly positive SOC pool trend. In the whole soil profile (0-60 cm), NTRRM, NTR, and CTRR sequestered SOC at the rates of 0.66, 0.27 and 2.24 Mg ha(-1) yr(-1). When manure was applied to substitute for the N lost from residue removal, the NTRRM tended to accumulate more SOC than NTR, and had similar accumulation as NTR in total N pools, grain yield, and aboveground biomass. Crop residue could be substituted by manure in this double-crop, irrigated system. Conventional tillage, with residue removed, was suitable in soil fertility and agronomic productivity relative to NTRRM and NTR in the NCP

Effects of cardiotrophin-1 on hemodynamics and cardiomyocyte apoptosis in rats with acute myocardial infarction

The effects of cardiotrophin-1 on hemodynamics, cardiac function, cardiomyocyte apoptosis, and expression of P53, Fas, Bax and Bcl-2 proteins in myocardium were determined in a rat model of acute myocardial infarction. Twenty-four male Sprague-Dawley rats weighing approximately 310 g were subjected to left coronary artery ligation. Seven days before surgery, the rats were randomized to receive cardiotrophin-1 (treated group) or phosphate-buffered saline (control group). Recombinant rat cardiotrophin-1 (2 μg in 1 ml phosphate-buffered saline) or phosphate-buffered saline (1 ml) was administered daily via the tail vein for 7 days (n=12 for each group). Hemodynamic parameters, apoptotic index, P53, Fas, Bax and Bcl-2 expression in myocardium were measured at 24 hours after coronary ligation. As compared with control animals, rats treated with cardiotrophin-1 had significantly higher mean arterial pressure, left ventricular systolic pressure and the maximum rate of left ventricular pressure rise or fall, and significantly lower left ventricular end-diastolic pressure. Cardiotrophin-1 pretreatment did not affect the heart rate, heart weight, body weight or the ratio of heart weight to body weight. The number of apoptotic cardiomyocytes in cardiotrophin-1 treated group was less than that in control group [(15.8±5.2)% vs (34.6±7.7) %,Plt0.01]. Cardiotrophin-1 pretreatment significantly inhibited P53, Fas and Bax, and increased Bcl-2 expression in myocardium

Interactions of the apolipoprotein C-III 3238C>G polymorphism and alcohol consumption on serum triglyceride levels

<p>Abstract</p> <p>Background</p> <p>Both apolipoprotein (Apo) C-III gene polymorphism and alcohol consumption have been associated with increased serum triglyceride (TG) levels, but their interactions on serum TG levels are not well known. The present study was undertaken to detect the interactions of the ApoC-III 3238C>G (rs5128) polymorphism and alcohol consumption on serum TG levels.</p> <p>Methods</p> <p>A total of 516 unrelated nondrinkers and 514 drinkers aged 15-89 were randomly selected from our previous stratified randomized cluster samples. Genotyping of the ApoC-III 3238C>G was performed by polymerase chain reaction and restriction fragment length polymorphism combined with gel electrophoresis, and then confirmed by direct sequencing. Interactions of the ApoC-III 3238C>G genotype and alcohol consumption was assessed by using a cross-product term between genotypes and the aforementioned factor.</p> <p>Results</p> <p>Serum total cholesterol (TC), TG, high-density lipoprotein cholesterol (HDL-C), ApoA-I and ApoB levels were higher in drinkers than in nondrinkers (<it>P </it>< 0.05-0.001). There was no significant difference in the genotypic and allelic frequencies between the two groups. Serum TG levels in nondrinkers were higher in CG genotype than in CC genotype (<it>P </it>< 0.01). Serum TC, TG, low-density lipoprotein cholesterol (LDL-C) and ApoB levels in drinkers were higher in GG genotype than in CC or CG genotype (<it>P </it>< 0.01 for all). Serum HDL-C levels in drinkers were higher in CG genotype than in CC genotype (<it>P </it>< 0.01). Serum TC, TG, HDL-C and ApoA-I levels in CC genotype, TC, HDL-C, ApoA-I levels and the ratio of ApoA-I to ApoB in CG genotype, and TC, TG, LDL-C, ApoA-I and ApoB levels in GG genotype were higher in drinkers than in nondrinkers (<it>P </it>< 0.05-0.01). But the ratio of ApoA-I to ApoB in GG genotype was lower in drinkers than in nondrinkers (<it>P </it>< 0.01). Multivariate logistic regression analysis showed that the levels of TC, TG and ApoB were correlated with genotype in nondrinkers (<it>P </it>< 0.05 for all). The levels of TC, LDL-C and ApoB were associated with genotype in drinkers (<it>P </it>< 0.01 for all). Serum lipid parameters were also correlated with age, sex, alcohol consumption, cigarette smoking, blood pressure, body weight, and body mass index in both groups.</p> <p>Conclusions</p> <p>This study suggests that the ApoC-III 3238CG heterozygotes benefited more from alcohol consumption than CC and GG homozygotes in increasing serum levels of HDL-C, ApoA-I, and the ratio of ApoA-I to ApoB, and lowering serum levels of TC and TG.</p

Single nucleotide polymorphisms in the mitochondrial displacement loop and outcome of esophageal squamous cell carcinoma

<p>Abstract</p> <p>Backgroud</p> <p>Accumulation of single nucleotide polymorphisms (SNPs) in the displacement loop (D-loop) of mitochondrial DNA (mtDNA) has been described for different types of cancers and might be associated with cancer risk and disease outcome. We used a population-based series of esophageal squamous cell carcinoma (ESCC) patients for investigating the prediction power of SNPs in mitochondrial D-loop.</p> <p>Methods</p> <p>The D-loop region of mtDNA was sequenced for 60 ESCC patients recorded in the Fourth Hospital of Hebei Medical University between 2003 and 2004. The 5 year survival curve were calculated with the Kaplan-Meier method and compared by the log-rank test at each SNP site, a multivariate survival analysis was also performed with the Cox proportional hazards method.</p> <p>Results</p> <p>The SNP sites of nucleotides 16274G/A, 16278C/T and 16399A/G were identified for prediction of post-operational survival by the log-rank test. In an overall multivariate analysis, the 16278 and 16399 alleles were identified as independent predictors of ESCC outcome. The length of survival of patients with the minor allele 16278T genotype was significantly shorter than that of patients with 16278C at the 16278 site (relative risk, 3.001; 95% CI, 1.029 - 8.756; <it>p </it>= 0.044). The length of survival of patients with the minor allele 16399G genotype was significantly shorter than that of patients with the more frequent allele 16399A at the 16399 site in ESCC patients (relative risk, 3.483; 95% CI, 1.068 - 11.359; <it>p </it>= 0.039).</p> <p>Conclusion</p> <p>Genetic polymorphisms in the D-loop are independent prognostic markers for patients with ESCC. Accordingly, the analysis of genetic polymorphisms in the mitochondrial D-loop can help identify patient subgroups at high risk of a poor disease outcome.</p

PQLM -- Multilingual Decentralized Portable Quantum Language Model for Privacy Protection

With careful manipulation, malicious agents can reverse engineer private information encoded in pre-trained language models. Security concerns motivate the development of quantum pre-training. In this work, we propose a highly portable quantum language model (PQLM) that can easily transmit information to downstream tasks on classical machines. The framework consists of a cloud PQLM built with random Variational Quantum Classifiers (VQC) and local models for downstream applications. We demonstrate the ad hoc portability of the quantum model by extracting only the word embeddings and effectively applying them to downstream tasks on classical machines. Our PQLM exhibits comparable performance to its classical counterpart on both intrinsic evaluation (loss, perplexity) and extrinsic evaluation (multilingual sentiment analysis accuracy) metrics. We also perform ablation studies on the factors affecting PQLM performance to analyze model stability. Our work establishes a theoretical foundation for a portable quantum pre-trained language model that could be trained on private data and made available for public use with privacy protection guarantees.Comment: 5 pages, 3 figures, 3 table