8,096 research outputs found
Medical diagnostics using designed molecules with sense and logic
Luminescent molecules responsive to cations, anions and even small molecules can be designed with the appropriate selectivity and sensitivity for monitoring physiological and pathological levels of analytes. We highlight some recent examples of designed molecules that can sense for a specific analyte or a combination of analytes in blood and in living cells. Furthermore, we demonstrate how molecules can be designed with built-in algorithms according to principles of Boolean logic to perform information processing. The potential future application of molecular systems able to perform multi-analyte sensing as `lab-on-a-molecule' systems for medical and environmental diagnostics is also presented.peer-reviewe
Systematic Differential Renormalization to All Orders
We present a systematic implementation of differential renormalization to all
orders in perturbation theory. The method is applied to individual Feynamn
graphs written in coordinate space. After isolating every singularity. which
appears in a bare diagram, we define a subtraction procedure which consists in
replacing the core of the singularity by its renormalized form givenby a
differential formula. The organizationof subtractions in subgraphs relies in
Bogoliubov's formula, fulfilling the requirements of locality, unitarity and
Lorentz invariance. Our method bypasses the use of an intermediate
regularization andautomatically delivers renormalized amplitudes which obey
renormalization group equations.Comment: TEX, 20 pages, UB-ECM-PF 93/4, 1 figureavailable upon reques
Nonperturbative results on the quark-gluon vertex
We present analytical and numerical results for the Dirac form factor of the
quark-gluon vertex in the quark symmetric limit, where the incoming and
outgoing quark momenta have the same magnitude but opposite sign. To accomplish
this, we compute the relevant components of the quark-ghost scattering kernel
at the one-loop dressed approximation, using as basic ingredients the full
quark propagator, obtained as a solution of the quark gap equation, and the
gluon propagator and ghost dressing function, obtained from large-volume
lattice simulations.Comment: 8 pages, 6 figures. Talk presented by A.C.A at Xth Quark Confinement
and the Hadron Spectrum, 8-12 October 2012, TUM Campus Garching, Munich,
German
Weighted Traces on Algebras of Pseudo-Differential Operators and Geometry of Loop Groups
Using {\it weighted traces} which are linear functionals of the type defined on the whole
algebra of (classical) pseudo-differential operators (P.D.O.s) and where is
some positive invertible elliptic operator, we investigate the geometry of loop
groups in the light of the cohomology of pseudo-differential operators. We set
up a geometric framework to study a class of infinite dimensional manifolds in
which we recover some results on the geometry of loop groups, using again
weighted traces. Along the way, we investigate properties of extensions of the
Radul and Schwinger cocycles defined with the help of weighted traces.Comment: 36 page
Development of polymer network of phenolic and epoxies resins mixed with linseed oil: pilot study
Epoxy resin was mixed with phenolic resins in different percentages by weight. Composite 40/60 means the proportion by weight of epoxy resin is 40 percent. It was found that only composites 50/50 and 40/60 could be cured in ambient conditions. Dynamic mechanical analysis showed that only these two composites form interpenetrating polymer network. The addition of linseed oil to the two resins results also in the formation of interpenetrating network irrespective of proportion by weight of the resins; the mechanical properties will only be better when the percentage by weight of epoxy resin is higher; the aim of reducing cost and at the same time maintaining the mechanical properties cannot be fully achieved because epoxy resin is much more expensive than its counterpart
Seleccion para resistencia a insectos. Manejo de la plaga y metodologia de evaluacion y seleccion
Obtaining insect-resistant var. involves (1) searching for sources of resistance, (2) reconfirming levels of resistance, (3) hybriding, and (4) selecting resistant progenies. Sources of resistance can be obtained from native var., introduced foreign var., wild (uncultivated) materials, and materials of other species of the same genera. In beans, this search is done through mass screening of germplasm, in which reconfirmation of resistance is extremely important, since the method allows uniform distribution of the pests within the field and the var. evaluated are necessarily attacked by the insect. (CIAT)La obtencion de var. resistentes a insectos comprende 1) la busqueda de fuentes de resistencia, 2) la reconfirmacion de los niveles de resistencia, 3) la hibridacion y 4) la seleccion de las progenies resistentes. Las fuentes de resistencia se pueden obtener a partir de var. criollas, var. foraneas introducidas, materiales silvestres y materiales de otras especies del mismo genero. En el caso del frijol, esta busqueda se hace mediante seleccion masal de germoplasma, donde la reconfirmacion de la resistencia es importante, ya que permite que la plaga se distribuya uniformemente dentro del campo de cultivo y evita la ocurrencia de un escape de la var. evaluada al ataque del insecto. (CIAT
Parenting Among Hispanic and Anglo-American Mothers With Young Children
The authors examined parenting practices and developmental expectations among 38 Hispanic and 38 Anglo-American mothers living in the United States. Mothers of children 3 to 5 years of age completed the Parent Behavior Checklist (R. A. Fox, 1994), a 100-item measure of parents\u27 developmental expectations, discipline, and nurturing practices. In addition, the authors appraised the Hispanic mothers\u27 acculturation and selected them for participation if their scores on an acculturation scale indicated (a) that their lifestyle was predominantly Hispanic and (b) that they had not been assimilated into the dominant culture. The 2 ethnic groups were also divided by socioeconomic status (SES). There were significant main effects for ethnicity and SES on the discipline and nurturing scores but not on the expectations scores. The Hispanic and higher SES mothers reported higher discipline and lower nurturing scores than did the Anglo-American and lower SES mothers. An unexpected finding was the tendency for higher SES Hispanic mothers to report more frequent use of discipline than the other 3 groups
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