Interaction between Granulation and Small-Scale Magnetic Flux Observed by Hinode

We study the relationship between granular development and magnetic field evolution in the quiet Sun. 6 typical cases are displayed to exhibit interaction between granules and magnetic elements, and we have obtained the following results. (1) A granule develops centrosymmetrically when no magnetic flux emerges within the granular cell. (2) A granule develops and splits noncentrosymmetrically while flux emerges at an outer part of the granular cell. (3) Magnetic flux emergence as a cluster of mixed polarities is detected at the position of a granule as soon as the granule breaks up. (4) A dipole emerges accompanying with the development of a granule, and the two elements of the dipole root in the adjacent intergranular lanes and face each other across the granule. Advected by the horizontal granular motion, the positive element of the dipole then cancels with pre-existing negative flux. (5) Flux cancellation also takes place between a positive element, which is advected by granular flow, and its surrounding negative flux. (6) While magnetic flux cancellation takes place at a granular cell, the granule shrinks and then disappears. (7) Horizontal magnetic fields enhance at the places where dipoles emerge and where opposite polarities cancel with each other, but only the horizontal fields between the dipolar elements point orderly from the positive element to the negative one. Our results reveal that granules and small-scale magnetic flux influence each other. Granular flow advects magnetic flux, and magnetic flux evolution suppresses granular development. There exist extremely large Doppler blue-shifts at the site of one cancelling magnetic element. This phenomenon may be caused by the upward flow produced by magnetic reconnection below the photosphere.Comment: 8 figures, 13 pages. RAA, in pres

Optimal estimation and control for lossy network: stability, convergence, and performance

In this paper, we study the problems of optimal estimation and control, i.e., the linear quadratic Gaussian (LQG) control, for systems with packet losses but without acknowledgment. Such acknowledgment is a signal sent by the actuator to inform the estimator of the incidence of control packet losses. For such system, which is usually called as a user datagram protocol (UDP)-like system, the optimal estimation is nonlinear and its calculation is time-consuming, making its corresponding optimal LQG problem complicated. We first propose two conditions: 1) the sensor has some computation abilities; and 2) the control command, exerted to the plant, is known to the sensor. For a UDP-like system satisfying these two conditions, we derive the optimal estimation. By constructing the finite and infinite product probability measure spaces for the estimation error covariances (EEC), we give the stability condition for the expected EEC, and show the existence of a measurable function to which the EEC converges in distribution, and propose some practical methods to evaluate the estimation performance. Finally, the LQG controllers are derived, and the conditions for the mean square stability of the closed-loop system are established

IDENTIFICATION OF TISSUE AND CIRCULATING BIOMARKERS FOR PREMALIGNANT AND MALIGNANT LESIONS

Recent advancement in technologies including next-generation sequencing and production-scale throughput qPCR have revolutionized the identification of biomarkers in the epidemiology field. In response to the vast amount of data generated from high-throughput technologies, novel inventions in the computer sciences fields have been applied to analyze these data. The current study demonstrates the application of such technologies in a variety of scenarios. I first described how targeted and whole-exome sequencing were used to identify somatic mutations which marked the differences between colorectal adenomas and adenocarcinomas. A statistical test based on the unique clustering pattern of tumor suppressor genes and oncogenes was employed to locate driver mutations. Random forest algorithm was performed to find somatic mutations which best classify samples into adenoma and adenocarcinoma. 20 important mutated genes (TP53, KRAS, APC, PIK3CA, SMAD4, FBXW7, CTNNB1, SYNE1, CDC27, CSMD1, NRAS, RYR3, NALCN, LRP1B, FAT4, ATM, TMPRSS13, SOX9, CSMD3, MED12) which constantly served to separate adenomas from adenocarcinomas were discovered. The Second project focused on exploring differentially expressed genes (DEG) and pathways enriched with such genes in colorectal adenomas and adenocarcinomas. Fold changes of paired premalignant/malignant lesions compared to normal adjacent tissues from the same patient were analyzed. And the ratio of 20-gene panel found in the first project were also found to differ between colorectal adenomas and cancers. The last project in the dissertation demonstrated the potential for microRNA (miR) in the serum to be used as a non-invasive prognostic factor for non-muscle invasive bladder cancers (NMIBC). With the help from a vast amount of miR profiles, we were able to identify two panels in overall population (miR-16/miR-378 + miR-24/miR-331-3p for recurrence and miR-16/miR-21 + miR-24/miR-375 for progression) and two panels in BCG-treated population (miR-16/miR-378 + miR-24/miR-331-3p for recurrence and miR-16/miR-21 + miR-24/miR-375 for progression). Taken together, these projects showcased the discovery of tissue and circulating biomarkers with cutting-edge technologies. These biomarkers could lead to more informed distribution of limited medical resources for monitoring clinical outcomes as well as the origin for future studies on deciphering the intricate mechanisms underlying tumorigenesis, host response and patient survival

Aplikasi Image Thresholding Untuk Segmentasi Objek

Salah satu operasi di dalam analisis citra adalah segmentasi citra, yaitu memisahkan objek dari latar belakangnya atau dari objek lain yang tidak menjadi perhatian. Metode sementasi yang sederhana adalah dengan operasi pengambangan (thresholding). Operasi pengambangan menghasilkan citra biner, yang dalam hal ini objek yang diacu di-set berwarna putih sedangkan latar belakangnya di-set berwarna hitam (atau sebaliknya bergantung kasusnya). Makalah ini mempresentasikan penggunaan operasi pengambangan untuk melakukan segmentasi objek. Eksperimen dilakukan dengan menggunakan kakas MATLAB. Hasil eksperimen memperlihatkan bahwa pemilihan nilai ambang (threshold) yang tepat sangat menentukan keberhasilan segmentasi

Development and Characterization of Polymorphic Microsatellite Markers (SSRs) for an Endemic Plant, Pseudolarix amabilis (Nelson) Rehd. (Pinaceae)

Pseudolarix (Pinaceae) is a vulnerable (sensu IUCN) monotypic genus restricted to southeastern China. To better understand levels of genetic diversity, population structure and gene flow among populations of P. amabilis, we developed five compound SSR markers and ten novel polymorphic expressed sequence tags (EST) derived microsatellites. The results showed that all 15 loci were polymorphic with the number of alleles per locus ranging from two to seven. The expected and observed heterozygosities varied from 0.169 to 0.752, and 0.000 to 1.000, respectively. The inbreeding coefficient ranged from −0.833 to 1.000. These markers will contribute to research on genetic diversity and population genetic structure of P. amabilis, which in turn will contribute to the species conservation