218 research outputs found
Genome-wide association study for 13 udder traits from linear type classification in cattle
Udder conformation traits are known to correlate with the incidence of clinical mastitis and the length of productive life. The results of a genome-wide association study based on imputed high-density genotypes of 1,637 -Brown Swiss sires and de-regressed breeding values for 13 udder traits are presented here. For seven traits significant signals could be observed in five regions on BTA3, BTA5, BTA6, BTA17, and BTA25. For fore udder length and teats diameter significant SNPs were found in a known region around 90 Mb on BTA6. For the trait rear udder height significant SNPs are positioned in the coding region of the SNX29gene. Several significant SNPs around 62 Mb on BTA17 are associated with the traits rear udder width, frontteat placement and rear teat placement. The function of potential candidate genes and the influence of substructure will be addressed as next steps
Pitch determination considering laryngealization effects in spoken dialogs
A frequent phenomenon in spoken dialogs of the information seeking type are short elliptic utterances whose mood (declarative or interrogative) can only be distinguished by intonation. The main acoustic evidence is conveyed by the fundamental frequency or Fo-contour. Many algorithms for Fo determination have been reported in the literature. A common problem are irregularities of speech known as "laryngealizations". This article describes an approach based on neural network techniques for the improved determination of fundamental frequency. First, an improved version of our neural network algorithm for reconstruction of the voice source signal (glottis signal) is presented. Second, the reconstructed voice source signal is used as input to another neural network distinguishing the three classes "voiceless", "voiced non-laryngealized", and "voiced laryngealized". Third, the results are used to improve an existing Fo algorithm. Results of this approach are presented and discussed in the context of the application in a spoken dialog system
Multi-step Multi-camera View Planning for Real-Time Visual Object Tracking
Abstract. We present a new method for planning the optimal next view for a probabilistic visual object tracking task. Our method uses a variable number of cameras, can plan an action sequence several time steps into the future, and allows for real-time usage due to a computation time which is linear both in the number of cameras and the number of time steps. The algorithm can also handle object loss in one, more or all cameras, interdependencies in the camera’s information contribution, and variable action costs. We evaluate our method by comparing it to previous approaches with a prere-corded sequence of real world images. From K. Franke et al., Pattern Recognition, 28th DAGM Symposium, Springer, 2006, (pp. 536–545).
On the Existence of Localized Excitations in Nonlinear Hamiltonian Lattices
We consider time-periodic nonlinear localized excitations (NLEs) on
one-dimensional translationally invariant Hamiltonian lattices with arbitrary
finite interaction range and arbitrary finite number of degrees of freedom per
unit cell. We analyse a mapping of the Fourier coefficients of the NLE
solution. NLEs correspond to homoclinic points in the phase space of this map.
Using dimensionality properties of separatrix manifolds of the mapping we show
the persistence of NLE solutions under perturbations of the system, provided
NLEs exist for the given system. For a class of nonintegrable Fermi-Pasta-Ulam
chains we rigorously prove the existence of NLE solutions.Comment: 13 pages, LaTeX, 2 figures will be mailed upon request (Phys. Rev. E,
in press
Urban source term estimation for mercury using a boundary-layer budget method
Mercury is a heavy metal of particular concern due to its adverse effects on
human health and the environment. Recognizing this problem, the UN
Minamata Convention on Mercury was recently adopted, where signatory
countries agreed to reduce anthropogenic mercury emissions. To evaluate the
effectiveness of the convention, quantitative knowledge on mercury emissions
is crucial. So far, bottom-up approaches have successfully been applied to
quantify mercury emission – especially for point sources. Distributed
sources make up a large share of the emission; however, they are still
poorly characterized. Here, we present a top-down approach to estimate
mercury emissions based on atmospheric measurements in the city of Zurich,
Switzerland. While monitoring the atmospheric mercury concentrations during
inversion periods in Zurich, we were able to relate the concentration
increase to the mercury emission strength of the city using a box model. By
means of this boundary-layer budget approach, we succeeded in narrowing down
the emissions of Zurich to range between 41±8 kg a−1 (upper bound) and 24±8 kg a−1 (lower bound). Thereby, we could quantify emissions from
mixed, diffuse and point-like sources and derive an annual mercury per capita
emission of 0.06 to 0.10 g a−1. The approach presented here has the
potential to support authorities in setting up inventories and to validate
emission estimations derived from the commonly applied bottom-up approaches.
Furthermore, our method is applicable to other compounds and to a wide range
of cities or other areas, where sources or sinks for mercury and
other atmospheric pollutants are presumed.</p
Eosinophils Are Important for Protection, Immunoregulation and Pathology during Infection with Nematode Microfilariae
Eosinophil responses typify both allergic and parasitic helminth disease. In helminthic disease, the role of eosinophils can be both protective in immune responses and destructive in pathological responses. To investigate whether eosinophils are involved in both protection and pathology during filarial nematode infection, we explored the role of eosinophils and their granule proteins, eosinophil peroxidase (EPO) and major basic protein-1 (MBP-1), during infection with Brugia malayi microfilariae. Using eosinophil-deficient mice (PHIL), we further clarify the role of eosinophils in clearance of microfilariae during primary, but not challenge infection in vivo. Deletion of EPO or MBP-1 alone was insufficient to abrogate parasite clearance suggesting that either these molecules are redundant or eosinophils act indirectly in parasite clearance via augmentation of other protective responses. Absence of eosinophils increased mast cell recruitment, but not other cell types, into the broncho-alveolar lavage fluid during challenge infection. In addition absence of eosinophils or EPO alone, augmented parasite-induced IgE responses, as measured by ELISA, demonstrating that eosinophils are involved in regulation of IgE. Whole body plethysmography indicated that nematode-induced changes in airway physiology were reduced in challenge infection in the absence of eosinophils and also during primary infection in the absence of EPO alone. However lack of eosinophils or MBP-1 actually increased goblet cell mucus production. We did not find any major differences in cytokine responses in the absence of eosinophils, EPO or MBP-1. These results reveal that eosinophils actively participate in regulation of IgE and goblet cell mucus production via granule secretion during nematode-induced pathology and highlight their importance both as effector cells, as damage-inducing cells and as supervisory cells that shape both innate and adaptive immunity
Special fast diffusion with slow asymptotics. Entropy method and flow on a Riemannian manifold
We consider the asymptotic behaviour of positive solutions of the
fast diffusion equation
posed for x\in\RR^d, , with a precise value for the exponent
. The space dimension is so that , and even
for . This case had been left open in the general study \cite{BBDGV} since
it requires quite different functional analytic methods, due in particular to
the absence of a spectral gap for the operator generating the linearized
evolution.
The linearization of this flow is interpreted here as the heat flow of the
Laplace-Beltrami operator of a suitable Riemannian Manifold (\RR^d,{\bf g}),
with a metric which is conformal to the standard \RR^d metric.
Studying the pointwise heat kernel behaviour allows to prove {suitable
Gagliardo-Nirenberg} inequalities associated to the generator. Such
inequalities in turn allow to study the nonlinear evolution as well, and to
determine its asymptotics, which is identical to the one satisfied by the
linearization. In terms of the rescaled representation, which is a nonlinear
Fokker--Planck equation, the convergence rate turns out to be polynomial in
time. This result is in contrast with the known exponential decay of such
representation for all other values of .Comment: 37 page
Kinetic modelling of competition and depletion of shared miRNAs by competing endogenous RNAs
Non-conding RNAs play a key role in the post-transcriptional regulation of
mRNA translation and turnover in eukaryotes. miRNAs, in particular, interact
with their target RNAs through protein-mediated, sequence-specific binding,
giving rise to extended and highly heterogeneous miRNA-RNA interaction
networks. Within such networks, competition to bind miRNAs can generate an
effective positive coupling between their targets. Competing endogenous RNAs
(ceRNAs) can in turn regulate each other through miRNA-mediated crosstalk.
Albeit potentially weak, ceRNA interactions can occur both dynamically,
affecting e.g. the regulatory clock, and at stationarity, in which case ceRNA
networks as a whole can be implicated in the composition of the cell's
proteome. Many features of ceRNA interactions, including the conditions under
which they become significant, can be unraveled by mathematical and in silico
models. We review the understanding of the ceRNA effect obtained within such
frameworks, focusing on the methods employed to quantify it, its role in the
processing of gene expression noise, and how network topology can determine its
reach.Comment: review article, 29 pages, 7 figure
Myeloperoxidase gene-463G > A polymorphism and premature coronary artery disease
We investigated the association between myeloperoxidase gene -463G > A polymorphism and premature coronary artery disease (CAD) in two Chinese population samples: 229 patients and 230 controls. Genotypes were determined by ligase detection reaction-polymerase chain reaction sequencing and the grouping technique. We found lower frequencies of both the A/A genotype and the A allele in patients (p < 0.05). Multivariate logistic regression showed that the risk of premature CAD in subjects carrying the AA genotype was reduced by 83% in relation to individuals carrying the G/G genotype (OR = 0.172, 95% CI: 0.057-0.526, p = 0.002). Our results indicate that -463G > A polymorphism of the myeloperoxidase gene is associated with premature CAD in Chinese individuals, suggesting that the AA genotype is a protective factor against premature CAD
- …