Finitely Many Dirac-Delta Interactions on Riemannian Manifolds

This work is intended as an attempt to study the non-perturbative renormalization of bound state problem of finitely many Dirac-delta interactions on Riemannian manifolds, S^2, H^2 and H^3. We formulate the problem in terms of a finite dimensional matrix, called the characteristic matrix. The bound state energies can be found from the characteristic equation. The characteristic matrix can be found after a regularization and renormalization by using a sharp cut-off in the eigenvalue spectrum of the Laplacian, as it is done in the flat space, or using the heat kernel method. These two approaches are equivalent in the case of compact manifolds. The heat kernel method has a general advantage to find lower bounds on the spectrum even for compact manifolds as shown in the case of S^2. The heat kernels for H^2 and H^3 are known explicitly, thus we can calculate the characteristic matrix. Using the result, we give lower bound estimates of the discrete spectrum.Comment: To be published in JM

Corrections For Two Photon Decays of chi_{c0} and chi_{c2} and Color Octet Contributions

Using the fact that the c-quark inside a charmonium moves with a small velocity v in the charmonium rest-frame, one can employ an expansion in v to study decays of charmonia and results at the leading order for chi_{c0,2} --> gamma gamma exist in the literature. We study corrections at the next-to-leading order in the framework of nonrelativistic QCD(NRQCD) factorization. The study presented here is different than previous approaches where chi_{c0,2} is taken as a bound-state of a c cbar pair and a nonrelativistic wave-function is used for the pair. We find that the corrections are consist not only of relativistic corrections, but also of corrections from Fock state components of chi_{c0,2} in which the c cbar pair is in a color-octet state. For chi_{c2} there is also a contribution from a Fock state component in which the pair is in a F-wave state. We determine the factorization formula for decay widths in the form of NRQCD matrix elements representing nonperturbative effects related to chi_{c0,2}, and calculate the perturbative coefficients at tree-level. Because the NRQCD matrix elements are unknown, a detailed prediction for the decay chi_{c0,2} --> gamma gamma can not be made, but the effect of these corrections can be determined at certain level. Estimations show that the effect is significant and can not be neglected.Comment: 8 pages, 2 figures; typo in Eq.(24) and Eq.(26) are corrected. add one referenc

Rare decays B→Xsl+l−B\to X_sl^+l^- and B→K(∗)l+l−B\to K^{(*)}l^+l^- in SM and beyond

After a brief review of the inclusive and exclusive rare semileptonic decays of B mesons in the standard model (SM), an overview of recent theoretical developments in this field is given. New physics effects on various observables such as branching ratio, backward-forward asymmetry, polarization of lepton and CP violation in the decays are anlyzed in models beyond SM (supersymmetric models and two Higgs doublet models).Comment: 6 pages, invited talk given at the Fourth International Conference on Hyperons, Charm and Beauty Hadrons, June 27-30, 2000, Valencia, Spain, to appear in the Proceedings of the Conference, typo correcte

Introduction to Deep Learning, Ubiquitous and Toy Computing Minitrack

N/

Convolution Neural Network Application in Kidney Tumor Segmentation on CT Images

In this paper, we propose an novel network model which is similar to V-net and prove its superiority and efficiency in tumor segmentation. And The model of segmentation of Kidney is Dense V-Network [1]. Then we ensemble the results of two networks together to get a final predict result for kidney and tumor. In particularly, we apply a series of method to image preprocessing, which is proved to be effective in improving dice

Overexpression of members of the microRNA-183 family is a risk factor for lung cancer: A case control study

<p>Abstract</p> <p>Background</p> <p>Lung cancer is the leading cause of cancer-related deaths worldwide. Early detection is considered critical for lung cancer treatment. MicroRNAs (miRNAs) have shown promise as diagnostic and prognostic indicators. This study was to identify specific miRNAs with diagnostic and prognostic value for patients with lung cancer, and to explore the correlation between expression profiles of miRNAs and patient survival.</p> <p>Methods</p> <p>Gene expression of members of the miR-183 family (miR-96, miR-182, and miR-183) were examined in 70 paired samples from lung cancer patients (primary cancer and non-cancerous tissues and sera), as well as 44 serum samples from normal volunteers and lung cancer cell lines by quantitative real-time reverse transcription polymerase chain reaction (RT-qPCR). The correlation between the expression of miRNAs in tissues, sera, and patient overall survival were also examined by log-rank and Cox regression analysis.</p> <p>Results</p> <p>Expression levels of members of the miR-183 family in lung cancer tumor and sera were higher than that of their normal counterparts. The miR-96 expression in tumors was positively associated with its expression in sera. Log-rank and Cox regression analyses demonstrated that high expression of tumor and serum miRNAs of the miR-183 family were associated with overall poor survival in patients with lung cancer.</p> <p>Conclusions</p> <p>Our results suggest that the expressions of miR-96, miR-182, and miR-183 in tumor and sera may be considered potential novel biomarkers for the diagnosis and prognosis of lung cancer.</p

The effects of solvent extraction on nanoporosity of marine-continental coal and mudstone

Coal and organic-rich mudstone develop massive nanopores, which control the storage of adsorbed and free gas, as well as fluid flows. Generation and retention of bitumen and hydrocarbons of oil window reservoirs add more uncertainty to the nanoporosity. Solvent extraction is a traditional way to regain unobstructed pore networks but may cause additional effects due to interactions with rocks, such as solvent adsorbing on clay surfaces or absorbing in kerogens. Selected marine-continental coal and mudstone in Eastern Ordos Basin were studied to investigate how pore structures are affected by these in-situ-sorptive compounds (namely residual bitumen and hydrocarbons) and altered by solvent extractions. Solvent extraction was performed to obtain bitumen-free subsamples. Organic petrology, bulk geochemical analyses and gas chromatography were used to characterize the samples and the extracts. Low-pressure argon and carbon dioxide adsorptions were utilized to characterize the nanopore structures of the samples before and after extraction. The samples, both coal and mudstone, are in oil windows, with vitrinite reflectance ranging from 0.807 to 1.135%. The coals are strongly affected by marine organic input, except for the sample C-4; the mudstones are sourced by either marine or terrestrial organic input, or their mixture. As for the coals affected by marine organic input, residual bitumen and hydrocarbons occupying or blocking pores <10 nm becomes weak with thermal maturation. Bitumen derived from terrestrial organic matter mainly affects small pores, since coal asphaltene molecules are much smaller than petroleum asphaltene molecules. The mudstone M-2 with high extract production showed an increase of nanopores after extraction, due to the exposure of the filled or blocked pores. However, most transitional mudstones saw decreases of the pores because pore shrinkage caused by solvents adsorbing on and swelling clay minerals (mainly kaolinite and illite/smectite mixed layers) counteracts the released pore spaces. Solvent extractions on the coals significantly increased the micropores <0.6 nm, since the heat of sorption of alkanes reaches the peak in the pores within 0.4–0.5 nm. By contrast, solvent extractions on the mudstones decreased the micropores ∼0.35 nm, which is perhaps caused by evaporative drying of solvent displacing residual water in clay

Instruments assessing problematic use of the internet and their associations with psychological distress among Ghanaian university students

Background: The present study evaluated the psychometric properties of Problematic Internet Use (PIU) instruments and their correlation with psychological distress and time spent on Internet activities among university students in Ghana. Methods: In the present cross-sectional survey design study, 520 participants (35.96% female) were recruited with a mean age of 19.55 years (SD = 1.94) from several university departments (i.e., Behavioral Sciences, Materials Engineering, Nursing and Midwifery, and Biochemistry and Biotechnology) of Kwame Nkrumah University of Science and Technology (KNUST) between 19 July and 04 August, 2023. Participants completed a survey that included the following measures: the Gaming Disorder Test (GDT), Gaming Disorder Scale for Adolescents (GADIS-A), Internet Gaming Disorder Scale-Short Form (IGDS9-SF), Bergen Social Media Addiction Scale (BSMAS), Smartphone Application Based Addiction Scale (SABAS), Nomophobia Questionnaire (NMP-Q), and the external criterion measure: Depression Anxiety Stress Scale-21 (DASS-21). Confirmatory factor analysis (CFA) was carried out to evaluate the structure of the instruments. Cronbach’s α, McDonald’s ω, and composite reliability were used to evaluate internal consistency. Pearson correlation was used to examine the associations between the scores of instruments assessing PIU, time spent on Internet activities, and the level of psychological distress. Results: Model fits confirmed the (i) unidimensional structure of the GDT, BSMAS, SABAS, IGDS9-SF, (ii) two-factor structure of the GADIS-A, and (iii) four-factor structure of the NMP-Q. Additionally, the study found that different types of PIU were significantly associated with psychological distress and time spent on related Internet activities. Conclusion: The six instruments validated in the present study demonstrated very good to excellent psychometric properties when applied to university students in Ghana. The significant associations between Internet-related disorders, time spent on Internet-related activities, and psychological distress highlight the importance of addressing issues of PIU among this population