Computing a high-dimensional euclidean embedding from an arbitrary smooth riemannian metric

International audienceThis article presents a new method to compute a self-intersection free high-dimensional Euclidean embedding (SIFHDE) for surfaces and volumes equipped with an arbitrary Riemannian metric. It is already known that given a high-dimensional (high-d) embedding, one can easily compute an anisotropic Voronoi diagram by back-mapping it to 3D space. We show here how to solve the inverse problem, i.e., given an input metric, compute a smooth intersection-free high-d embedding of the input such that the pullback metric of the embedding matches the input metric. Our numerical solution mechanism matches the deformation gradient of the 3D → higher-d mapping with the given Riemannian metric. We demonstrate applications of the method, by being used to construct anisotropic Restricted Voronoi Diagram (RVD) and anisotropic meshing, that are otherwise extremely difficult to compute. In the SIFHDE-space constructed by our algorithm, difficult 3D anisotropic computations are replaced with simple Euclidean computations, resulting in an isotropic RVD and its dual mesh on this high-d embedding. The results are compared with the state-ofthe-art in anisotropic surface and volume meshings using several examples and evaluation metrics

Effects of ambient temperature on growth performance, slaughter traits, meat quality and serum antioxidant function in Pekin duck

The present study investigated the effects of temperature on growth performance, slaughtering traits, meat quality and antioxidant function of Pekin ducks from 21–42 d of age. Single factor analysis of variance was used in this experiment, 144 21 d-old Pekin ducks were randomly allotted to 4 environmentally controlled chambers: T20 (20°C), T23 (23°C), T26 (26°C) and T29 (29°C), with 3 replicates in each group (12 ducks in each replicate), the relative humidity of all groups is 74%. During the 21-day trial period, feed and water were freely available. At 42 d, the BW (body weight) and ADG (average daily gain) of T26 were significantly lower than T20 (p < 0.05), and the T29 was significantly lower than T20 and T23 (p < 0.05). The ADFI (average daily feed intake) of T26 and T29 were significantly lower than T20 and T23 (p < 0.05). Compared to the T29, the T20 showed a significant increase oblique body length and chest width, and both the keel length and thigh muscle weight significantly increased in both the T20 and T23, while the pectoral muscle weight increased significantly in other groups (p < 0.05). The cooking loss of the T29 was the lowest (p < 0.05). The T-AOC (total antioxidant capacity) of T29 was significantly higher than the other groups (p < 0.05), the SOD (superoxide dismutase) in the T29 was significantly higher than the T23 and T26 (p < 0.05). In conditions of 74% relative humidity, the BW and ADFI of Pekin ducks significantly decrease when the environmental temperature exceeds 26°C, and the development of body size and muscle weight follows this pattern. The growth development and serum redox state of Pekin ducks are more ideal and stable at temperatures of 20°C and 23°C

Oral Delivery of the Sj23LHD-GST Antigen by Salmonella typhimurium Type III Secretion System Protects against Schistosoma japonicum Infection in Mice

Schistosomiasis japonica is a zoonotic parasitic disease and occurs predominantly in Southeast Asia and China. Using a simple, cheap, yet efficient oral method to deliver the vaccine antigen would benefit to control its transmission in that the oral vaccine could be made into a preparation and mixed with feedstuffs of livestock hosts. In this study, we used an attenuated S. typhimurium strain VNP20009, whose safety has been demonstrated in phase I clinical trial, to express the bivalent Schistosoma japonicum antigen Sj23LHD-GST by an intracellular activated promoter (nirB) and deliver it to host cells through type III secretion system. After oral vaccination of this recombinant strain, efficient protection against S. japonicum challenge was induced in mice. Mean while, granuloma formation in the liver was improved significantly in the immunized mice. This protective immune response was Th1 specific type as evidenced by increase in the production of IL-12 and IFN-γ. This work provides an alternative S. japonicum vaccine for livestock and humans

Evolutionary Dynamics Analysis of Human Metapneumovirus Subtype A2: Genetic Evidence for Its Dominant Epidemic

Human metapneumovirus (hMPV) is a respiratory viral pathogen in children worldwide. hMPV is divided into four subtypes: hMPV_A1, hMPV_A2, hMPV_B1, and hMPV_B2. hMPV_A2 can be further divided into hMPV_A2a and A2b based on phylogenetic analysis. The typical prevalence pattern of hMPV involves a shift of the predominant subtype within one or two years. However, hMPV_A2, in particular hMPV_A2b, has circulated worldwide with a several years long term high epidemic. To study this distinct epidemic behavior of hMPV_A2, we analyzed 294 sequences of partial G genes of the virus from different countries. Molecular evolutionary data indicates that hMPV_A2 evolved toward heterogeneity faster than the other subtypes. Specifically, a Bayesian skyline plot analysis revealed that hMPV_A2 has undergone a generally upward fluctuation since 1997, whereas the other subtypes experienced only one upward fluctuation. Although hMPV_A2 showed a lower value of mean dN/dS than the other subtypes, it had the largest number of positive selection sites. Meanwhile, various styles of mutation were observed in the mutation hotspots of hMPV_A2b. Bayesian phylogeography analysis also revealed two fusions of diffusion routes of hMPV_A2b in India (June 2006) and Beijing, China (June 2008). Sequences of hMPV_A2b retrieved from GenBank boosted simultaneously with the two fusions respectively, indicating that fusion of genetic transmission routes from different regions improved survival of hMPV_A2. Epidemic and evolutionary dynamics of hMPV_A2b were similar to those of hMPV_A2. Overall, our findings provide important molecular insights into hMPV epidemics and viral variation, and explain the occurrence of an atypical epidemic of hMPV_A2, particularly hMPV_A2b

Wider Angle Egg Turning during Incubation Enhances Yolk Utilization and Promotes Goose Embryo Development

We aimed to investigate how wide-angle turning of eggs during incubation affected yolk utilization and the associated molecular mechanism, along with improved goose embryonic development. In total, 1152 eggs (mean weight: 143.33 ± 5.43 g) were divided equally and incubated in two commercial incubators with tray turning angles adjusted differently, to either 50° or 70°. Following incubation under the standard temperature and humidity level, turning eggs by 70° increased embryonic days 22 (E22), embryo mass, gosling weight at hatching, and egg hatchability, but reduced E22 yolk mass compared with those after turning eggs by 50°. Lipidomic analyses of the yolk revealed that egg turning at 70° reduced the concentrations of 17 of 1132 detected total lipids, including diglycerides, triglycerides, and phospholipids. Furthermore, the 70° egg turning upregulated the expression of genes related to lipolysis and fat digestion enzymes, such as lipase, cathepsin B, and prosaposin, as well as apolipoprotein B, apolipoprotein A4, very low-density lipoprotein receptor, low-density lipoprotein receptor-related protein 2, and thrombospondin receptor, which are genes involved in lipid transportation. Thus, a 70° egg turning angle during incubation enhances yolk utilization through the upregulation of lipolysis and fat digestion-related gene expression, thereby promoting embryonic development and improving egg hatchability and gosling quality

Vein Network and Climatic Factors Predict the Leaf Economic Spectrum of Desert Plants in Xinjiang, China

The leaf economic spectrum (LES) has been repeatedly verified with regional and global datasets. However, the LES of desert plants and its drivers has not been fully explored at the species level. In this study, we sampled three desert perennial plant species (Alhagi sparsifolia, Karelinia caspia, and Apocynum venetum) at three different geographical areas of distribution in Xinjiang, China, and measured 10 leaf economic traits to determine their strategy of resource utilization. The scores of the first axis from the principal component analysis of 10 leaf economic traits as a continuous variable define the LES. This study showed that the LES did exist in desert plants in this region. The leaf economic spectrum shifted from a more conservative strategy to a more acquisitive strategy with increasing contents of soil potassium (K) and the ratio of K to phosphorus. Except for the vein density of A. venetum, which quadratically correlated with LES, the vein density, distance between veins, and vein loopiness significantly positively correlated with the LES (p < 0.05), indicating a covariation and tradeoff relationship. The annual mean temperature was significantly negatively correlated with LES, while the annual mean precipitation (MAP) and the aridity index (AI), which was calculated by the ratio of MAP to potential evapotranspiration, significantly positively correlated with the LES. Of these, vein loopiness and AI were more effective at predicting the change in LES from anatomical and climatic perspectives owing to their high regression coefficients (R2). The findings of this study will substantially improve the understanding of the strategies of desert plants to utilize resources and predict the structure and function of ecosystems