The Blueshift Of Civ Broad Emission Line In Qsos

For the sample from Ge et al. of 87 low-$z$ Palomar--Green (PG) quasi-stellar objects (QSOs) and 130 high-$z$ QSOs ($0<z<5$) with \hb-based single-epoch supermassive black hole (SMBH) masses, we performed a uniform decomposition of the \civ\ $\lambda$1549 broad-line profile. Based on the rest frame defined by the \oiii $\lambda$5007 narrow emission line, a medium-strong positive correlation is found between the \civ\ blueshift and the luminosity at 5100\AA\ or the Eddington ratio \leddR. A medium-strong negative relationship is found between the \civ\ blueshift and \civ\ equivalent width. These results support the postulation where the radiation pressure may be the driver of \civ\ blueshift. There is a medium strong correlation between the mass ratio of \civ-based to \hb-based \mbh and the \civ\ blueshift, which indicates that the bias for \civ-based \mbh is affected by the \civ\ profile.Comment: 18 pages, 8 figures, Accepted for publication in A

Dimension reduction and efficient recommender system for large-scale complex data

Large-scale complex data have drawn great attention in recent years, which play an important role in information technology and biomedical research. In this thesis, we address three challenging issues: sufficient dimension reduction for longitudinal data, nonignorable missing data with refreshment samples, and large-scale recommender systems. In the first part of this thesis, we incorporate correlation structure in sufficient dimension reduction for longitudinal data. Existing sufficient dimension reduction approaches assuming independence may lead to substantial loss of efficiency. We apply the quadratic inference function to incorporate the correlation information and apply the transformation method to recover the central subspace. The proposed estimators are shown to be consistent and more efficient than the ones assuming independence. In addition, the estimated central subspace is also efficient when the correlation information is taken into account. We compare the proposed method with other dimension reduction approaches through simulation studies, and apply this new approach to an environmental health study. In the second part of this thesis, we address nonignorable missing data which occur frequently in longitudinal studies and can cause biased estimations. Refreshment samples which recruit new subjects in subsequent waves from the original population could mitigate the bias. In this thesis, we introduce a mixed-effects estimating equation approach which enables one to incorporate refreshment samples and recover missing information. We show that the proposed method achieves consistency and asymptotic normality for fixed-effect estimation under shared-parameter models, and we extend it to a more general nonignorable-missing framework. Our finite sample simulation studies show the effectiveness and robustness of the proposed method under different missing mechanisms. In addition, we apply our method to election poll longitudinal survey data with refreshment samples from the 2007-2008 Associated Press–Yahoo! News. In the third part of this thesis, we develop a novel recommender system which track users' preferences and recommend items of interest effectively. In this thesis, we propose a group-specific method to utilize dependency information from users and items which share similar characteristics under the singular value decomposition framework. The new approach is effective for the "cold-start" problem, where new users and new items' information is not available from the existing data collection. One advantage of the proposed model is that we are able to incorporate information from the missing mechanism and group-specific features through clustering based on variables associated with missing patterns. In addition, we propose a new algorithm that embeds a back-fitting algorithm into alternating least squares, which avoids large matrices operation and big memory storage, and therefore makes it feasible to achieve scalable computing. Our simulation studies and MovieLens data analysis both indicate that the proposed group-specific method improves prediction accuracy significantly compared to existing competitive recommender system approaches

Application of whole-cell fluorescent in situ hybridization (FISH) of molecular detection of toxic alexandrium species

Paralytic shellfish poisoning is a type of seafood poisoning due to contamination of a group of neurotoxin, collectively known as saxitoxin, in filter feeding mollusks. Monitoring of PSP producing organism especially from the genus of Alexandrium is very challenging as identification of toxic species is only possible based on plate tabulation. In this study, oligonucleotide probes using whole cell fluorescence in situ hybridization (FISH) to detect toxic A. tamiyavanichii and A. minutum were developed. In silico probe design for the 2 species was carried out using sequences database of Alexandrium species found in Malaysia. Probe specificity was assessed based on GC content, melting temperature, Gibbs free energy change and E value. Potential species-specific probes for A. minutum and A. tamiyavanichii were designated as [L-S-Amin-680- (A. minutum)-A-24] and [L-S-Atam-286-(A. tamiyavanichii)-A-23]. Specific probe for A. tamiyavanichii, TAMIS1 was synthesized and tested against A. tamiyavanichii and all other related species. Probe uniC and uniR were applied as positive and negative control. Our result show high specificity of TAMIS1 to A. tamiyavanichii with no cross-reactivity to four other Alexandrium (A. minutum, A. leei, A. tamarense and A.affine). FISH condition applied in this study with hybridization temperature, 35 °C and formamide 40 % work well with no unspecific binding observed. The probe TAMIS1 should be adopted in national HAB monitoring program in order to increase the efficiency in detection of A. tamiyavanichii

New contribution to the knowledge of the genus Vietetropis Komiya, 1997 with the description of a new species from the Guangxi province in southern China (Coleoptera, Cerambycidae, Prioninae, Anacolini)

Abstract The peculiar Prioninae genus Vietetropis Komiya, 1997 comprised up to now a single species, V. viridis, described at the same time. A new species has been recently found in southern China in the Guangxi province. It is described under the name V. cheni sp. nov. and compared to the original type species of the genus V. viridis. Résumé Le genre particulier de Prioninae Vietetropis Komiya, 1997 ne comprenait jusqu'à présent qu'une seule espèce, V. viridis, décrite au même moment. Une nouvelle espèce a récemment été découverte dans le sud de la Chine, dans la province du Guangxi. Elle est décrite sous le nom de V. cheni sp. nov. et comparée à l'espèce-type du genre V. viridis

The Essence of Nested Composition

Calculi with disjoint intersection types support an introduction form for intersections called the merge operator, while retaining a coherent semantics. Disjoint intersections types have great potential to serve as a foundation for powerful, flexible and yet type-safe and easy to reason OO languages. This paper shows how to significantly increase the expressive power of disjoint intersection types by adding support for nested subtyping and composition, which enables simple forms of family polymorphism to be expressed in the calculus. The extension with nested subtyping and composition is challenging, for two different reasons. Firstly, the subtyping relation that supports these features is non-trivial, especially when it comes to obtaining an algorithmic version. Secondly, the syntactic method used to prove coherence for previous calculi with disjoint intersection types is too inflexible, making it hard to extend those calculi with new features (such as nested subtyping). We show how to address the first problem by adapting and extending the Barendregt, Coppo and Dezani (BCD) subtyping rules for intersections with records and coercions. A sound and complete algorithmic system is obtained by using an approach inspired by Pierce\u27s work. To address the second problem we replace the syntactic method to prove coherence, by a semantic proof method based on logical relations. Our work has been fully formalized in Coq, and we have an implementation of our calculus