8,967 research outputs found
Fischer decomposition by inframonogenic functions
Let D denote the Dirac operator in the Euclidean space R^m. In this paper, we
present a refinement of the biharmonic functions and at the same time an
extension of the monogenic functions by considering the equation DfD=0. The
solutions of this "sandwich" equation, which we call inframonogenic functions,
are used to obtain a new Fischer decomposition for homogeneous polynomials in
R^m.Comment: 10 pages, accepted for publication in CUBO, A Mathematical Journa
Reunion overseas: introduced wild boars and cultivated orange trees interact in the Brazilian Atlantic forest
Little is known concerning novel interactions between species that typically
interact in their native range but, as a consequence of human activity, are also interacting out of their original
distribution under new ecological conditions. Objective: We investigate the interaction between the orange tree
and wild boar, both of which share Asian origins and have been introduced to the Americas (i.e. the overseas).
Methods: Specifically, we assessed whether i) wild boars consume orange (Citrus sinensis) fruits and seeds
in orchards adjacent to a remnant of the Atlantic Forest of Brazil, ii) the orange seeds are viable after passing
through boar’s digestive tract and iii) whether the orange tree may naturalise in the forest remnant assisted by
wild boars. Results: Our camera surveys indicated that wild boar was by far the most frequent consumer of
orange fruits (40.5 % of camera trap-days). A considerable proportion of sown orange seeds extracted from fresh
boar feces emerged seedlings (27.8 %, N = 386) under controlled greenhouse conditions. Further, 37.6 % of sown
seeds (N = 500) in the forest remnant emerged seedlings in July 2015; however, after ~4 years (March 2019)
only 9 seedlings survived (i.e. 4.8 %, N = 188). Finally, 52 sweet orange seedlings were found during surveys
within the forest remnant which is intensively used by wild boars. This study indicates a high potential of boars
to act as effective seed dispersers of the sweet orange. However, harsh competition with native vegetation and
the incidence of lethal diseases, which quickly kill sweet orange trees under non-agricultural conditions, could
seriously limit orange tree establishment in the forest. Conclusions: Our results have important implications not
only because the wild boar could be a vector of potential invasive species, but also because they disperse seeds
of some native species (e.g. the queen palm, Syagrus romanzofiana) in defaunated forests, where large native
seed dispersers are missing; thus, wild boars could exert critical ecological functions lost due to human activityinfo:eu-repo/semantics/publishedVersio
Linear Time-Dependent Invariants for Scalar Fields and Noether's Theorem
The infinite number of time-dependent linear in field and conjugated momenta
invariants is derived for the scalar field using the Noether's theorem
procedure.Comment: LaTeX, 6 pages, preprint of Instituto de Ciencias Nucleares, UNAM,
Departamento de F\ii sica and Matem\'aticas Aplicadas, M\'exico D. F. ,
M\'exico No. 04 (1994
Squeezing in a 2-D generalized oscillator
A two-dimensional generalized oscillator with time-dependent parameters is
considered to study the two-mode squeezing phenomena. Specific choices of the
parameters are used to determine the dispersion matrix and analytic
expressions, in terms of standard hermite polynomials, of the wavefunctions and
photon distributions. (to be publish in the Third Workshop on Squeezed States
and Uncertainty Relations, Baltimore, USA, (August 1993))Comment: LaTeX, 5 pages, preprint of Instituto de Ciencias Nucleares, UNAM
Departamento de F\ii sica and Matem\'aticas Aplicadas, No. 02 (1994
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