26 research outputs found
Kerr-Schild spacetimes with (A)dS background
General properties of Kerr-Schild spacetimes with (A)dS background in
arbitrary dimension are studied. It is shown that the geodetic Kerr-Schild
vector k is a multiple WAND of the spacetime. Einstein Kerr-Schild spacetimes
with non-expanding k are shown to be of Weyl type N, while the expanding
spacetimes are of type II or D. It is shown that this class of spacetimes obeys
the optical constraint. This allows us to solve Sachs equation, determine
r-dependence of boost weight zero components of the Weyl tensor and discuss
curvature singularities.Comment: 17 pages, minor change
Spatio-temporal Models of Lymphangiogenesis in Wound Healing
Several studies suggest that one possible cause of impaired wound healing is
failed or insufficient lymphangiogenesis, that is the formation of new
lymphatic capillaries. Although many mathematical models have been developed to
describe the formation of blood capillaries (angiogenesis), very few have been
proposed for the regeneration of the lymphatic network. Lymphangiogenesis is a
markedly different process from angiogenesis, occurring at different times and
in response to different chemical stimuli. Two main hypotheses have been
proposed: 1) lymphatic capillaries sprout from existing interrupted ones at the
edge of the wound in analogy to the blood angiogenesis case; 2) lymphatic
endothelial cells first pool in the wound region following the lymph flow and
then, once sufficiently populated, start to form a network. Here we present two
PDE models describing lymphangiogenesis according to these two different
hypotheses. Further, we include the effect of advection due to interstitial
flow and lymph flow coming from open capillaries. The variables represent
different cell densities and growth factor concentrations, and where possible
the parameters are estimated from biological data. The models are then solved
numerically and the results are compared with the available biological
literature.Comment: 29 pages, 9 Figures, 6 Tables (39 figure files in total
Markovian Equilibrium in Infinite Horizon Economies with Incomplete Markets and Public Policy
Stereocontrolled construction of decahydro quinoline ring systems: the case of lepadin alkaloids (Review)
Carga de trabalho de enfermagem em transplante de células-tronco hematopoiéticas: estudo de coorte
Adaptation of the Amsterdam Inventory for Auditory Disability and Handicap into Cantonese
This research aimed to adapt the Amsterdam Inventory for Auditory Disability and Handicap (AIADH) into Cantonese. A total of six Cantonese-English bilingual speakers participated in the adaptation of the AIADH. One-hundred and thirty-
three normal-hearing and hearing-impaired Chinese-speaking participants from Hong Kong completed the Cantonese adaptation of the questionnaire (C-AIADH). Good internal consistency and reliability of the questionnaire was indicated by a high Cronbach's alpha coefficient. Statistical analysis showed that the newly adapted questionnaire could differentiate between normal-hearing and hearing-impaired subjects. Percentiles were computed from the data obtained from normal-hearing subjects (n = 35) to obtain normal scores for the C-AIADH. The findings
and possible clinical uses are discussed