2,713 research outputs found
Practices Used by Dairy Farmers to Reduce Seasonal Production Variability
The objective of this analysis was to identify the production practices used by farmers to change seasonal production. Production practices included milk production per cow, proportion of cows milking, number of first lactation animals entering the herd, number of cows leaving the herd, number of days to first breeding, and calves born. Farms that participated in a seasonal pricing plan during 1993, 1994, and 1995 decreased production practice seasonality in response to price premiums, which caused a decrease in production seasonality compared to nonparticipating farms. Participating farms showed a preference for adjusting entering first lactation animals and number of calves born, but did make adjustments in other practices as well.Livestock Production/Industries,
On parity functions in conformal field theories
We examine general aspects of parity functions arising in rational conformal
field theories, as a result of Galois theoretic properties of modular
transformations. We focus more specifically on parity functions associated with
affine Lie algebras, for which we give two efficient formulas. We investigate
the consequences of these for the modular invariance problem.Comment: 18 pages, no figure, LaTeX2
Two-qubit parametric amplifier: large amplification of weak signals
Using numerical simulations, we show that two coupled qubits can amplify a
weak signal about hundredfold. This can be achieved if the two qubits are
biased simultaneously by this weak signal and a strong pump signal, both of
which having frequencies close to the inter-level transitions in the system.
The weak signal strongly affects the spectrum generated by the strong pumping
drive by producing and controlling mixed harmonics with amplitudes of the order
of the main harmonic of the strong drive. We show that the amplification is
robust with respect to noise, with an intensity of the order of the weak
signal. When deviating from the optimal regime (corresponding to strong qubit
coupling and a weak-signal frequency equal to the inter-level transition
frequency) the proposed amplifier becomes less efficient, but it can still
considerably enhance a weak signal (by several tens). We therefore propose to
use coupled qubits as a combined parametric amplifier and frequency shifter.Comment: 6 figure
Valid and reliable assessment of wellness among adolescents: Do you know what youâre measuring?
Measuring wellness among adolescents is an emerging trend among professionals and researchers endeavouring to influence youth as they establish lifestyle patterns in this critical period of life. This discussion highlights instruments used to measure adolescentsâ wellness, and considers the empirical data supporting the validity and reliability of those instruments. In summary, adolescentsâ wellness is an important indicator of future health and lifestyle habits. There are a number of tools available to measure wellness, each with its own focus, depending on the definition or model from which it was developed. This might cause debate regarding the appropriateness of some instruments for evaluating wellness. The majority of wellness evaluation approaches used with adolescent populations have less than ideal validation. A âgold standardâ definition could lead to the standardisation of a theoretical model against which wellness instruments could be validated. The absence of peer-reviewed studies reporting psychometric testing for wellness evaluation instruments used with adolescents is of concern given their growing popularity and highlights a priority area for future research in this field
Electronic structure and optical properties of ZnX (X=O, S, Se, Te)
Electronic band structure and optical properties of zinc monochalcogenides
with zinc-blende- and wurtzite-type structures were studied using the ab initio
density functional method within the LDA, GGA, and LDA+U approaches.
Calculations of the optical spectra have been performed for the energy range
0-20 eV, with and without including spin-orbit coupling. Reflectivity,
absorption and extinction coefficients, and refractive index have been computed
from the imaginary part of the dielectric function using the Kramers--Kronig
transformations. A rigid shift of the calculated optical spectra is found to
provide a good first approximation to reproduce experimental observations for
almost all the zinc monochalcogenide phases considered. By inspection of the
calculated and experimentally determined band-gap values for the zinc
monochalcogenide series, the band gap of ZnO with zinc-blende structure has
been estimated.Comment: 17 pages, 10 figure
T145 Comprehensive flow cytometry tracking of regulatory T cells and other lymphocyte subsets during HD IL-2 therapy for melanoma
High dose IL-2 (HD IL-2) has been extensively used as an immunotherapy against metastatic melanoma However, why HD IL-2 is effective only in a subset of patients and whether predictive biomarkers, before or early during the course of therapy, can be used to improve response rates remain unresolved. In addition, it has been found that IL-2 therapy potently expands CD4+CD25+Foxp3+ T-regulatory cells (Tregs) but how Treg cell levels, phenotype, and function change and whether specific subsets of Tregs are activated and expanded during HD IL-2 therapy is remain unclear. In this study, we performed comprehensive multi-parameter FACS analysis of patient blood before and two days after the last bolus of IL-2 infusion during cycle 1 of HD IL-2 therapy. Two lymphocyte subsets were found to expand the most during the first cycle of IL-2 therapy: CD4+CD25+Foxp3+ Tregs expressing an activation marker, inducible costimulator (ICOS), and CD3-CD56hiCD16loPerforin+ NK cells. ICOS+ Tregs expressed significantly higher levels of CD25, Foxp3 and had a more activated phenotype than ICOSâ Tregs as indicated by lower levels of CD45RA and CD127 expression. Further phenotypic characterization revealed a more suppressive phenotype on ICOS+ Treg with higher expression levels of CD39, CD73, and TGF-ÎČ/LAP than ICOSâ Treg. ICOS+ Tregs were also the predominant Treg cells that secreted IL-10 and have potent T-cell suppressor function. Majority of ICOS+ Tregs from HD IL-2-treated patients were Ki67+ and exhibited an enhanced proliferative response to IL-2 ex vivo relative to ICOSâ Tregs. Functional analysis revealed that ICOS+ Tregs secreted little IFN- and IL-2 in comparison to CD4+Foxp3 â cells. Furthermore, analysis on 38 IL-2-treated patients at MD Anderson, we found that non-responders had a significantly higher degree of ICOS+ Treg expansion than responders during the first cycle of IL-2 therapy, while no significant changes in the ICOSâ or bulk Treg population. In conclusion, our data suggests that tracking changes in ICOS+ Tregs early during the course of HD IL-2 therapy may be a new predictive biomarker of clinical outcome
Spin-echo small-angle neutron scattering (SESANS) studies of diblock copolymer nanoparticles
Poly(glycerol monomethacrylate)âpoly(benzyl methacrylate) (PGMAâPBzMA) diblock copolymer nanoparticles were synthesized via polymerization-induced self-assembly (PISA) using reversible additionâfragmentation chain-transfer (RAFT) aqueous emulsion polymerization in D2O. Such PISA syntheses produce sterically-stabilized nanoparticles in situ and can be performed at relatively high copolymer concentrations (up to 50 wt%). This PGMAâPBzMA formulation is known to form only spherical nanoparticles in water using aqueous emulsion polymerization (Macromolecules, 2014, 47, 5613â5623), which makes it an ideal model system for exploring new characterization methods. The polymer micelles were characterized using small-angle X-ray scattering (SAXS) and a recently developed form of neutron scattering, spin-echo small-angle neutron scattering (SESANS). As far as we are aware, this is the first report of a study of polymer micelles by SESANS, and the data agree well with reciprocal-space scattering. Using this technique enables characterization of the concentrated, as synthesized dispersions directly without dilution, and this will provide a method to study self-assembled polymer systems that have concentration dependent morphologies, while still maintaining the advantages of scattering techniques
On the Classification of Diagonal Coset Modular Invariants
We relate in a novel way the modular matrices of GKO diagonal cosets without
fixed points to those of WZNW tensor products. Using this we classify all
modular invariant partition functions of
for all positive integer level , and for all and infinitely many (in fact, for
each a positive density of ). Of all these classifications, only that
for had been known. Our lists include many
new invariants.Comment: 24 pp (plain tex
The structures of Hausdorff metric in non-Archimedean spaces
For non-Archimedean spaces and let and be the
ballean of (the family of the balls in ), the space of mappings from
to and the space of mappings from the ballen of to
respectively. By studying explicitly the Hausdorff metric structures related to
these spaces, we construct several families of new metric structures (e.g., ) on the corresponding spaces, and study their convergence,
structural relation, law of variation in the variable including
some normed algebra structure. To some extent, the class is a counterpart of the usual Levy-Prohorov metric in the
probability measure spaces, but it behaves very differently, and is interesting
in itself. Moreover, when is compact and is a complete
non-Archimedean field, we construct and study a Dudly type metric of the space
of valued measures on Comment: 43 pages; this is the final version. Thanks to the anonymous
referee's helpful comments, the original Theorem 2.10 is removed, Proposition
2.10 is stated now in a stronger form, the abstact is rewritten, the
Monna-Springer is used in Section 5, and Theorem 5.2 is written in a more
general for
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