1,953 research outputs found
Factors associated with invasive lung aspergillosis and the significance of positive aspergillus culture after liver transplantation
From January 1981 to December 1990, 2180 patients underwent orthotopic liver transplantation at the University of Pittsburgh. Thirty-two patients (1.5%) were identified with invasive aspergillosis (29 lung, 2 intraabdominal, 1 meningitis). Of 29 patients with invasive lung disease, only 23 (79%) had positive culture (Aspergillus fumigatus, 20; Aspergillus flavus, 3). Forty-eight variables were analyzed and compared in 23 patients with invasive disease with positive cultures and 9 patients with colonization only. The variables associated with pulmonary invasive disease, by univariate analysis, were surgical time (P =.03), presence of laparotomies (P =.02), higher creatinine level at time of Aspergillus isolation (P =.01), and use of OKT3 (P =.02). However, in a multivariate analysis, only the last two (creatinine, OKT3) were associated with invasive lung aspergillosis. Of 4 patients with positive abdominal wound culture, 2 had local invasive aspergillosis. Therefore, positive cultures of Aspergillus organisms from respiratory secretions and wound drainage may represent invasive disease and should not be ignored. © 1992 the University of Chicago
Hamiltonian description of singular Lagrangian systems with spontaneously broken time translation symmetry
Shapere and Wilczek recently found some singular Lagrangian systems which
spontaneously breaks time translation symmetry. The common feature of their
models is that the energy functions are multivalued in terms of the canonical
phase space variables and the symmetry breaking ground states are all located
at the brunching point singularities. By enlarging the phase space and making
use of Dirac's theory on constrained Hamiltonian systems, we present the
Hamiltonian description of some of the models discussed by Shapere and Wilczek
and found that both the multivaluedness and the brunching point singularities
can be avoided, while the spontaneous breaking oftime translation becomes more
transparent. It is also shown that the breaking of time translation is always
accompanied by the breaking of time reversal.Comment: 13 page
ESTIMATING SHALLOW WATER TABLE CONTRIBUTION TO SOYBEAN WATER USE IN ARGENTINA
The existence of a shallow water table can be an important water source for rainfed agricultural production. The objective of this study is to quantify the water contribution of the water table to soybean water requirements in the center of Argentina by means of a crop simulation model that relates water balance to grain production. The model was calibrated and validated considering soil water records up to 1 m deep, and the oscillation in the water table depth and grain yield during two climatically contrasted growth seasons (2004/05 - 2005/06). The adjustment obtained between observed and simulated values was: 1.8 mm for soil humidity, between 0.26 and 0.01 m for oscillation of the water table and between 49 and 920 kg ha-1 for grain yield. The results obtained with the simulation indicate that the water table contributed between 12 and 30% of the total water used by the crop in each growing season studied. It was concluded that, in rainfed agricultural conditions, a water table oscillating between 1.5 and 2 m deep makes it possible to stabilize the yield of rainfed soybean
Singular open book structures from real mappings
We prove extensions of Milnor's theorem for germs with nonisolated
singularity and use them to find new classes of genuine real analytic mappings
with positive dimensional singular locus \Sing \psi \subset
\psi^{-1}(0), for which the Milnor fibration exists and yields an open book
structure with singular binding.Comment: more remark
- …