Some Contributions to the Class of Two-Sex Branching Processes Depending on the Number of Couples in the Population

2000 Mathematics Subject Classification: 60J80We consider the class of two-sex branching processes with offspring and mating depending on the number of couples in the population introduced in Molina et al. (2008). In addition to its theoretical interest, this class also has clear practical implications, especially in population dynamics. We investigate its extinction probability and limiting behavior. By considering different probabilistic approaches, necessary and sufficient conditions for its almost sure extinction are determined. Assuming the nonextinction, some limiting results are derived.This research has been supported by the Ministerio de Ciencia e Innovaci´on of Spain, the Junta de Extremadura, and the FEDER (grants MTM2009-13248 and GR10118) and by the Natural Sciences Foundation of China (grant 10971048)

Comprehensive profiling of rhizome-associated alternative splicing and alternative polyadenylation in moso bamboo (Phyllostachys edulis).

Moso bamboo (Phyllostachys edulis) represents one of the fastest-spreading plants in the world, due in part to its well-developed rhizome system. However, the post-transcriptional mechanism for the development of the rhizome system in bamboo has not been comprehensively studied. We therefore used a combination of single-molecule long-read sequencing technology and polyadenylation site sequencing (PAS-seq) to re-annotate the bamboo genome, and identify genome-wide alternative splicing (AS) and alternative polyadenylation (APA) in the rhizome system. In total, 145 522 mapped full-length non-chimeric (FLNC) reads were analyzed, resulting in the correction of 2241 mis-annotated genes and the identification of 8091 previously unannotated loci. Notably, more than 42 280 distinct splicing isoforms were derived from 128 667 intron-containing full-length FLNC reads, including a large number of AS events associated with rhizome systems. In addition, we characterized 25 069 polyadenylation sites from 11 450 genes, 6311 of which have APA sites. Further analysis of intronic polyadenylation revealed that LTR/Gypsy and LTR/Copia were two major transposable elements within the intronic polyadenylation region. Furthermore, this study provided a quantitative atlas of poly(A) usage. Several hundred differential poly(A) sites in the rhizome-root system were identified. Taken together, these results suggest that post-transcriptional regulation may potentially have a vital role in the underground rhizome-root system

SEC24A deficiency lowers plasma cholesterol through reduced PCSK9 secretion.

The secretory pathway of eukaryotic cells packages cargo proteins into COPII-coated vesicles for transport from the endoplasmic reticulum (ER) to the Golgi. We now report that complete genetic deficiency for the COPII component SEC24A is compatible with normal survival and development in the mouse, despite the fundamental role of SEC24 in COPII vesicle formation and cargo recruitment. However, these animals exhibit markedly reduced plasma cholesterol, with mutations in Apoe and Ldlr epistatic to Sec24a, suggesting a receptor-mediated lipoprotein clearance mechanism. Consistent with these data, hepatic LDLR levels are up-regulated in SEC24A-deficient cells as a consequence of specific dependence of PCSK9, a negative regulator of LDLR, on SEC24A for efficient exit from the ER. Our findings also identify partial overlap in cargo selectivity between SEC24A and SEC24B, suggesting a previously unappreciated heterogeneity in the recruitment of secretory proteins to the COPII vesicles that extends to soluble as well as trans-membrane cargoes. DOI:http://dx.doi.org/10.7554/eLife.00444.001

A case study on non-parametric design method in ODM collaborative product development

Abstract: There are two distinct solid design methodologies -parametric and non-parametric approaches. In the past 20 years, most industrial CAD users have been upgrading their CAD design methods from the non-parametric approach to the parametric one. However, with the new trends of globalisation, outsourcing and collaboration, it is timely to ask whether the parametric design is still effective. In this paper, a case study based on the non-parametric CAD modelling approach with a distributed collaborative design system is presented. A real project for a typical mechatronic product is studied in depth. Based on the case study and field observations, we have found that non-parametric modelling methodology enables collaboration in several ways. Further, the non-parametric modelling methodology shows many advantages. A comparative analysis has also been carried out via matching ODM design activities to the strengths and weaknesses of the two approaches. Finally, suggestions for future research directions of collaborative design are given. Keywords: collaborative product development; parametric design; non-parametric design; feature-based design; design methodology. Reference to this paper should be made as follows: Ma, Y-S. (2005) 'A case study on non-parametric design method in ODM collaborative product development', Int

Free vibration analysis for wind turbine structure by component mode synthesis method

Based on free interface component modal synthesis method, the free vibration behavior of wind turbine structures is investigated. The wind turbine structure is divided into three parts including tower, wheel hub-cabin and rotor. The tower is modeled as an isotropic metal cantilever beam, the blade as thin-walled composite beam and the wheel hub-cabin as a rigid body due to its large extensional stiffness, bending stiffness and torsion stiffness compared with tower and blades. The displacements of the blades are described by thin-walled composite beam theory. Galerkin’s method is used to discretize blades and tower. Employing Lagrange method, the motion equations of blades are derived and then stiffness and mass matrices are obtained. The natural frequencies and mode shapes of the wind turbine structure are predicted by numerical simulations. Numerical results using the present model are validated by ANSYS software results

Camera Recognition and Laser Detection based on EKF-SLAM in the Autonomous Navigation of Humanoid Robot

The ability of autonomous navigation of the humanoid robot under unknown environment is very important to real-life applications. EKF-SLAM based on the camera recognition and laser detection for humanoid robot NAO is presented in this paper. Camera recognition is used to recognize if the object is a landmark. Because the computational resources needed for the feature-based position estimation are quite expensive, the laser instead of the camera provides the position of the landmark. A fractional order proportional-integral (PI) controller is designed to reduce the derivation of the NAO robot from the desired path during autonomous navigation. Experiments show that the proposed method is valid and reliable for autonomous navigation of the NAO robot under unknown environment