513 research outputs found
Hominin palaeoecology in Late Pliocene Malawi : first insights from isotopes (13C, 18O) in mammal teeth
Carbon-13 and oxygen-18 abundances were measured in large mammal skeletal remains (tooth enamel, dentine and bone) from the Chiwondo Beds in Malawi, which were dated by biostratigraphic correlation to ca. 2.5 million years ago. The biologic isotopic patterns, in particular the difference in carbon-13 abundances between grazers and browsers and the difference in oxygen-18 abundances between semi-aquatic and terrestrial herbivores, were preserved in enamel, but not in dentine and bone. The isotopic results obtained from the skeletal remains from the Chiwondo Beds indicate a dominance of savannah habitats with some trees and shrubs. This environment was more arid than the contemporaneous Ndolanya Beds in Tanzania. The present study confirms that robust australopithecines were able to live in relatively arid environments and were not confined to more mesic environments elsewhere in southern Africa
The union of unit balls has quadratic complexity, even if they all contain the origin
We provide a lower bound construction showing that the union of unit balls in
three-dimensional space has quadratic complexity, even if they all contain the
origin. This settles a conjecture of Sharir.Comment: 5 pages, 5 figure
Effect of "wooden breast" appearance on poultry meat quality, histological traits, and lesions characterization
The purposes of the study were to investigate the effects of Wooden Breast (WB) myodegeneration on poultry meat quality and to give a contribution in typing lesions morphology. At a poultry meat cutting facility, 474 carcasses of a high-breast-yield hybrid chickens were inspected for WB condition, and 30 normal (N) and 30 affected (WB) breast fillets (Pectoralis major) were randomly selected. The WB condition represented 53.2% of the examined carcasses. Weight, cross sectional area (CSA), pH, L*, a*, b* colour values, water-holding capacity, and Warner-Bratzler shear force were determined. Samples were also visually and histologically evaluated. Affected samples were heavier, thicker, paler (P < 0.001), and characterized by palpatory hardness and lower water holding capacity (P < 0.05). Macroscopically, abnormalities were primarily localized in the cranial portion of the fillet and defined by the presence of bulges, petechiae, fluid and clear exudate, and higher pH. Microscopically, the WB condition was characterized by muscle fibres with greater CSA (P < 0.001) and higher giant fibres prevalence (P < 0.01). Data suggest a relationship between breast weight and WB condition
A counterexample to parabolic dichotomies in holomorphic iteration
We give an example of a parabolic holomorphic self-map of the unit ball
whose canonical Kobayashi hyperbolic
semi-model is given by an elliptic automorphism of the disc , which can be chosen to be different from the identity. As a
consequence, in contrast to the one dimensional case, this provides a first
example of a holomorphic self-map of the unit ball which has points with zero
hyperbolic step and points with nonzero hyperbolic step, solving an open
question and showing that parabolic dynamics in the ball is
radically different from parabolic dynamics in the disc. The example is
obtained via a geometric method, embedding the ball as a domain
in the bidisc that is forward invariant
and absorbing for the map , where denotes the right half-plane. We also show that a complete
Kobayashi hyperbolic domain with such properties cannot be Gromov
hyperbolic w.r.t. the Kobayashi distance (hence, it cannot be biholomorphic to
) if an additional quantitative geometric condition is satisfied
A Coupled Euler-Lagrange CFD Modelling of Droplets-To-Film
In this paper, a droplet to film interaction model technique is presented. In the proposed approach, the liquid and gas continua are modelled using an enhanced Volume of Fluid (VoF) technique while the droplets are tracked using a Lagrangian framework and are coupled to the Eulerian phases using source terms. The eventual target application is an aeroengine bearing chamber in which oil is found as droplets, shed from the bearings, splashing on impact, separated from wall surfaces at obstacles or simply re-entrained, and as a continuum oil film coating the bearing chamber outer walls which it also cools. In finite volume CFD techniques, a prohibitively large number of cells would be required to describe the details of the droplet impact phenomenon. Based on published correlations, the splashing droplets are created and tracked as Lagrangian particles. The flowing film and the gas continua are handled with an enhanced Volume of Fluid technique
Organizational Discourse and Networks Mobilization: A Case Study of the
Mobilizing local and regional actor
Development of methods and electronic circuits for ultrasound imaging based on innovative probes
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