Compactification of a map which is mapped to itself

We prove that if $T: X \to X$ is a selfmap of a set $X$ such that \bigcap \{T^{n}X: n\in N}\} is a one-point set, then the set $X$ can be endowed with a compact Hausdorff topology so that $T$ is continuous.Comment: 5 page

Scattering in an environment

The cross section of elastic electron-proton scattering taking place in an electron gas is calculated within the Closed Time Path method. It is found to be the sum of two terms, one being the expression in the vacuum except that it involves dressing due to the electron gas. The other term is due to the scattering particles-electron gas entanglement. This term dominates the usual one when the exchange energy is in the vicinity of the Fermi energy. Furthermore it makes the trajectories of the colliding particles more consistent and the collision more irreversible, rendering the scattering more classical in this regime.Comment: final version to appear in Phys. Rev.

A visual survey of the inshore fish communities of Gran Canaria (Canary Islands).

An in situ visual survey technique (5 minutes and 100 m2 area) was used to assess the inshore fishes off Gran Canaria. In 1996, 211 visual surveys were conducted at 7 localities. Locations differed significantly among each other with regards to the number of species per survey (ANOVA: p < 0.01). The five most abundant species were Chromis limbatus, Boops boops, Pomadasys incisus, Abudefduf luridus, and Thalassoma pavo with respective mean abundances of 65.6, 37.4, 16.7, 8.7, and 4.5 per 100 m2. Detrended Correspondence Analysis, a multivariate ordination technique showed that the major determinant of community structure is substrate type. The majority of the surveyed species had low axis 1 ordination scores indicating a strong association with a hard substrate. The step-wise linear regression models explained 45.3 % and 1 1.4% of the variation in the first and second axis survey ordination scores, respectively

Fossil overpressures compartments? A case study from the Eifel area and some general aspects

Fluid overpressures are well known from hydrocarbon exploration in many sedimentary basins. They can reach almost lithostatic values, and may cause the fracturing of rock. Fracturing allows the discharge of fluid overpressure, and fluid flows along a hydraulic gradient towards a low pressure reservoir. Different mechanisms may cause the precipitation from the fluid, such as a fluid pressure drop, a variation of temperature at the low pressure reservoir, or a different rock type inducing different Eh-pH conditions. Such precipitates in fractures are called veins, which often display paleo-fluid overpressures in rocks. In this study, we present some results from Devonian clastic sedimentary rocks of the Eifel area. Results are compared with other sedimentary basins to highlight some general aspects.conferenc

Clay smear: Review of mechanisms and applications

AbstractClay smear is a collection of fault processes and resulting fault structures that form when normal faults deform layered sedimentary sections. These elusive structures have attracted deep interest from researchers interested in subsurface fluid flow, particularly in the oil and gas industry. In the four decades since the association between clay-smear structures and oil and gas accumulations was introduced, there has been extensive research into the fault processes that create clay smear and the resulting effects of that clay smear on fluid flow. We undertake a critical review of the literature associated with outcrop studies, laboratory and numerical modeling, and subsurface field studies of clay smear and propose a comprehensive summary that encompasses all of these elements. Important fault processes that contribute to clay smear are defined in the context of the ratio of rock strength and in situ effective stresses, the geometric evolution of fault systems, and the composition of the faulted section. We find that although there has been progress in all avenues pursued, progress has been uneven, and the processes that disrupt clay smears are mostly overlooked. We highlight those research areas that we think will yield the greatest benefit and suggest that taking these emerging results within a more process-based framework presented here will lead to a new generation of clay smear models

Development of an internet based system for modeling biotin metabolism using Bayesian networks

Biotin is an essential water-soluble vitamin crucial for maintaining normal body functions. The importance of biotin for human health has been under-appreciated but there is plenty of opportunity for future research with great importance for human health. Currently, carrying out predictions of biotin metabolism involves tedious manual manipulations. In this paper, we report the development of BiotinNet, an internet based program that uses Bayesian networks to integrate published data on various aspects of biotin metabolism. Users can provide a combination of values on the levels of biotin related metabolites to obtain the predictions on other metabolites that are not specified. As an inherent feature of Bayesian networks, the uncertainty of the prediction is also quantified and reported to the user. This program enables convenient in silico experiments regarding biotin metabolism, which can help researchers design future experiments while new data can be continuously incorporated

On the Properties of a Tree-Structured Server Process

Let X0 be a nonnegative integer-valued random variable and let an independent copy of X0 be assigned to each leaf of a binary tree of depth k. If X0 and X0′ are adjacent leaves, let X1=(X0−1)++(X0′−1)+ be assigned to the parent node. In general, if Xj and Xj′ are assigned to adjacent nodes at level j = 0,⋯, k − 1, then Xj and Xj′ are, in turn, independent and the value assigned to their parent node is then Xj+1=(Xj−1)++(Xj′−1)+. We ask what is the behavior of Xk as k→∞. We give sufficient conditions for Xk→∞ and for Xk→0 and ask whether these are the only nontrivial possibilities. The problem is of interest because it asks for the asymptotics of a nonlinear transform which has an expansive term (the + in the sense of addition) and a contractive term (the + in the sense of positive part)

Yield and chemical composition of plant parts of silage maize (Zea mays L) hybrids and their interest for biogas production

Silage maize (Zea mays L) hybrids bred in Martonvásár were tested for morphological traits, yield and chemical composition of the whole plant and the plant parts in three years (2010-2012). Biogas production of the hybrids was investigated in 2009 and 2010. The dry matter, protein, starch, water soluble carbohydrates, neutral detergent fibre, acid detergent fibre, lignin and in vitro digestible organic matter contents were measured by NIR spectroscopy. The ratio of ear attachment height to plant height was smaller, the leaf number above the ear and the proportion of the leaves in the total plant dry matter was greater for leafy hybrids. It was concluded that the differences in the chemical composition of the parts of the same genotype were greater than between the same parts of different genotypes. The leaves had the greatest protein content. The starch and WSC content in the ear was significantly higher than in the other plant parts. The ear had the lowest lignin content and the highest IVDOM content compared to other plant parts. NDF and ADF contents were greatest in the stalk below the ear. Significant differences were found for WSC content of the plant parts of leafy and non-leafy hybrids. Digestible dry matter yield (DDMY) was calculated from individual dry matter production, plant number per hectare and digestible organic matter content. The highest DDMY value was recorded for Siloking (19.18 t ha-1). Biogas yield was highest for Mv Massil (659 l kg-1 DM) with 61.38% methane concentration. Leafy hybrids produced significantly more biogas than conventional hybrids. Biogas yield proved to have significant positive correlations with starch and WSC content, and negative correlations with protein and lignin content