555 research outputs found
Extending Grazing In Heifer Development Systems Decreases Cost Without Compromising Production
Three experiments compared heifer development systems. In Exp. 1, 299 heifers (253 ± 2 kg) from 3 yr were used to compare dry lot (DL) to grazing corn residue (CR) post weaning. Heifers in the DL consumed a common diet after weaning for 187 d until breeding. The CR heifers grazed for 145 d with a supplement (0.45 kg/d; 28% CP) and were then fed in the DL until breeding. In Exp. 2, 270 heifers (225 ± 2 kg) in 3 yr grazed Sandhills winter range (WR) or CR with a supplement (0.45 kg/d; 28% CP) post weaning. In Exp. 3, 180 heifers (262 ± 3 kg) in 2 yr grazed Eastern Nebraska WR or CR with a supplement (0.45 – 0.90 kg/d; 29% CP) post weaning. The CR heifers had lower (P \u3c 0.001) ADG before breeding compared to DL or WR heifers in Exp. 1 and 2, but WR and CR were similar (P = 0.66) in Exp. 3. The DL and WR heifers were heavier (P \u3c 0.003) than CR at breeding and pregnancy diagnosis in Exp. 1 and 2, but similar (P = 0.62) in Exp. 3. The percentage of heifers pubertal at breeding was greater (P \u3c 0.001) for DL than CR in Exp. 1, for WR than CR in yr 1 and 2 of Exp. 2 (P \u3c 0.01), but similar (P = 0.36) in Exp. 3. Pregnancy rate to AI was lower (P = 0.08) for CR than DL heifers in Exp. 1, but not different (P = 0.89) in Exp. 3. Final pregnancy rate was not affected (P ≥ 0.27) in Exp. 1, 2 or 3. In Exp. 2,, yr 2, CR heifers required (P = 0.01) more calving assistance than WR. Milk production of WR heifers was greater (P = 0.04) than CR in Exp. 3. Calf weaning BW, two-year old AI (Exp. 1 and 3) and final pregnancy rates (Exp. 1, 2 and 3) were not different (P \u3e 0.10). Development grazing CR reduced cost by $45/pregnancy compared to DL, but cost of WR was similar to CR. Development grazing CR reduces ADG before breeding without sacrificing final pregnancy rate. Development grazing WR increases milk production, but does not increase weaning BW. Grazing CR during heifer development reduces cost compared to DL. Grazing CR or WR is suitable for heifer development at similar cost
Particles with anomalous magnetic moment in external e.m. fields: the proper time formulation
In this paper we evaluate the expression for the Green function of a
pseudo-classical spinning particle interacting with constant electromagnetic
external fields by taking into account the anomalous magnetic and electric
moments of the particle. The spin degrees of freedom are described in terms of
Grassmann variables and the evolution operator is obtained through the
Fock-Schwinger proper time method.Comment: 10 page
Superstar in Noncommutative Superspace via Covariant Quantization of the Superparticle
A covariant quantization method is developed for the off-shell superparticle
in 10 dimensions. On-shell it is consistent with lightcone quantization, while
off-shell it gives a noncommutative superspace that realizes non-linearly a
hidden 11-dimensional super Poincare symmetry. The non-linear commutation rules
are then used to construct the supersymmetric generalization of the covariant
Moyal star product in noncommutative superspace. As one of the possible
applications, we propose this new product as the star product in supersymmetric
string field theory. Furthermore, the formalism introduces new techniques and
concepts in noncommutative (super)geometry.Comment: 17 pages, LaTe
Volume, asymmetry and reciprocal relationships between paranasal sinuses: a 3D segmentation study on head CT-scans
Relevamiento y asignación taxonómica de himenópteros potencialmente polinizadores en un cultivo de soja
A la luz de recientes investigaciones que comprueban la contribución de los insectos polinizadores sobre el rendimiento de la soja, el presente trabajo evalúa cualitativamente y cuantitativamente los himenópteros presentes en la canopia del cultivo, con el objeto de estimar cuáles conforman el complejo potencialmente polinizador de esta oleaginosa. Para ello, se capturaron insectos mediante red entomológica en la canopia de un cultivo de soja, en diferentes horarios del dÃa y a lo largo del periodo de floración. Los resultados mostraron a la familia Formicidae como el grupo de himenópteros más numerosos, seguido por la familia Apidae y otras cinco familias escasamente representadas. Se alienta a considerar a los himenópteros potenciales polinizadores del cultivo de soja, en la redefinición de los Umbrales de Daño Económico y se destaca la necesidad de ampliar el muestreo a otras regiones productivas y durante un mayor número de años a fin de robustecer conclusiones.In light of recent research that confirms the contribution of pollinating insects to the yield of soybean, the present work qualitatively and quantitatively evaluates the hymenoptera present in the crop canopy, in order to propose which make up the potentially pollinating complex of this oilseed crop. To do this, insects were captured with an entomological net by sweeping the canopy of a soybean crop at different times of the day and
throughout the flowering period. The results showed the Formicidae family as the most numerous hymenoptera group, followed by the Apidae family and five other poorly represented families. It is encouraged to consider the hymenoptera as potential pollinators of soybean in the redefinition of the Economic Damage Thresholds,
and the need to extend the sampling to other productive regions and for a greater number of years in order to
strengthen conclusions.Gerencia de Comunicación e Imagen InstitucionalFil: Blettler, Diego César. Provincia de Entre RÃos. Centro de Investigaciones CientÃficas y Transferencia de TecnologÃa a la Producción. Universidad Autónoma de Entre RÃos. Centro de Investigaciones CientÃficas y Transferencia de TecnologÃa a la Producción. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Centro CientÃfico Tecnológico Conicet - Santa Fe. Centro de Investigaciones CientÃficas y Transferencia de TecnologÃa a la Producción; ArgentinaFil: Fagundez, Guillermina Andrea. Provincia de Entre RÃos. Centro de Investigaciones CientÃficas y Transferencia de TecnologÃa a la Producción. Universidad Autónoma de Entre RÃos. Centro de Investigaciones CientÃficas y Transferencia de TecnologÃa a la Producción. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Centro CientÃfico Tecnológico Conicet - Santa Fe. Centro de Investigaciones CientÃficas y Transferencia de TecnologÃa a la Producción; ArgentinaFil: Chemez, D.M. Provincia de Entre RÃos. Centro de Investigaciones CientÃficas y Transferencia de TecnologÃa a la Producción. Universidad Autónoma de Entre RÃos. Centro de Investigaciones CientÃficas y Transferencia de TecnologÃa a la Producción. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Centro CientÃfico Tecnológico Conicet - Santa Fe. Centro de Investigaciones CientÃficas y Transferencia de TecnologÃa a la Producción; Argentin
Multilevel Contracts for Trusted Components
This article contributes to the design and the verification of trusted
components and services. The contracts are declined at several levels to cover
then different facets, such as component consistency, compatibility or
correctness. The article introduces multilevel contracts and a
design+verification process for handling and analysing these contracts in
component models. The approach is implemented with the COSTO platform that
supports the Kmelia component model. A case study illustrates the overall
approach.Comment: In Proceedings WCSI 2010, arXiv:1010.233
On the perturbative chiral ring for marginally deformed N=4 SYM theories
For \cal{N}=1 SU(N) SYM theories obtained as marginal deformations of the
\cal{N}=4 parent theory we study perturbatively some sectors of the chiral ring
in the weak coupling regime and for finite N. By exploiting the relation
between the definition of chiral ring and the effective superpotential we
develop a procedure which allows us to easily determine protected chiral
operators up to n loops once the superpotential has been computed up to (n-1)
order. In particular, for the Lunin-Maldacena beta-deformed theory we determine
the quantum structure of a large class of operators up to three loops. We
extend our procedure to more general Leigh-Strassler deformations whose chiral
ring is not fully understood yet and determine the weight-two and weight-three
sectors up to two loops. We use our results to infer general properties of the
chiral ring.Comment: LaTex, 40 pages, 4 figures, uses JHEP3; v2: minor correction
Perioperative Chemotherapy in Gastroesophageal Cancer. A Retrospective Monocenter Evaluation of 42 Cases
Background: Perioperative chemotherapy increases the overall and progression-free survival of patients suffering from resectable adenocarcinomas of the lower esophagus, gastroesophageal junction and stomach (GEC). Comparing different chemotherapy regimens platin-based protocols with 5-fluorouracil (5-FU)/calcium folinate (CF) or oral fluoropyrimidines were favorable in terms of efficacy and side-effects. However, there is no consensus which regimen is the most efficacious. Methods: 42 consecutive patients with resectable GEC (UICC II and III) were treated with 3 pre- and postoperative chemotherapy cycles each consisting of epirubicin, oxaliplatin and capecitabine (EOX). We analyzed the overall survival, progression-free survival and toxicity retrospectively in comparison to published data. Results: The median overall survival in our cohort was 29 months and the progression-free survival was 17 months. The most frequent grade 3 and 4 toxicities during preoperative chemotherapy were diarrhea (16.7%), leukocytopenia (9.5%) and nausea (9.5%); overall 38.1% of our patients suffered from grade 3 or 4 toxicity. Surgery was carried out in 83% of our patients, 69% of those achieved R0 resection. Conclusion: Comparing our data with the results of previously published randomized trials EOX is at least non-inferior with regard to overall survival, progression-free survival and toxicity. In conclusion, EOX is an appropriate perioperative therapy for patients with resectable GEC
A meta-analysis of water quality and aquatic macrophyte responses in 18 lakes treated with lanthanum modified bentonite (PHOSLOCK®)
Lanthanum (La) modified bentonite is being increasingly used as a geo-engineering tool for the control of phosphorus (P) release from lake bed sediments to overlying waters. However, little is known about its effectiveness in controlling P across a wide range of lake conditions or of its potential to promote rapid ecological recovery. We combined data from 18 treated lakes to examine the lake population responses in the 24 months following La-bentonite application (range of La-bentonite loads: 1.4 to 6.7 tonnes ha-1) in concentrations of surface water total phosphorus (TP; data available from 15 lakes), soluble reactive phosphorus (SRP; 14 lakes), and chlorophyll a (15 lakes), and in Secchi disk depths (15 lakes), aquatic macrophyte species numbers (6 lakes) and aquatic macrophyte maximum colonisation depths (4 lakes) across the treated lakes. Data availability varied across the lakes and variables, and in general monitoring was more frequent closer to the application dates. Median annual TP concentrations decreased significantly across the lakes, following the La-bentonite applications (from 0.08 mg L-1 in the 24 months pre-application to 0.03 mg L-1 in the 24 months post-application), particularly in autumn (0.08 mg L-1 to 0.03 mg L-1) and winter (0.08 mg L-1 to 0.02 mg L-1). Significant decreases in SRP concentrations over annual (0.019 mg L-1 to 0.005 mg L-1), summer (0.018 mg L-1 to 0.004 mg L-1), autumn (0.019 mg L-1 to 0.005 mg L-1) and winter (0.033 mg L-1 to 0.005 mg L-1) periods were also reported. P concentrations following La-bentonite application varied across the lakes and were correlated positively with dissolved organic carbon concentrations. Relatively weak, but significant responses were reported for summer chlorophyll a concentrations and Secchi disk depths following La-bentonite applications, the 75th percentile values decreasing from 119 μg L-1 to 74 μg L-1 and increasing from 398 cm to 506 cm, respectively. Aquatic macrophyte species numbers and maximum colonisation depths increased following La-bentonite application from a median of 5.5 species to 7.0 species and a median of 1.8 m to 2.5 m, respectively. The aquatic macrophyte responses varied significantly between lakes. La-bentonite application resulted in a general improvement in water quality leading to an improvement in the aquatic macrophyte community within 24 months. However, because, the responses were highly site-specific, we stress the need for comprehensive pre- and post-application assessments of processes driving ecological structure and function in candidate lakes to inform future use of this and similar products
Jamming at Zero Temperature and Zero Applied Stress: the Epitome of Disorder
We have studied how 2- and 3- dimensional systems made up of particles
interacting with finite range, repulsive potentials jam (i.e., develop a yield
stress in a disordered state) at zero temperature and applied stress. For each
configuration, there is a unique jamming threshold, , at which
particles can no longer avoid each other and the bulk and shear moduli
simultaneously become non-zero. The distribution of values becomes
narrower as the system size increases, so that essentially all configurations
jam at the same in the thermodynamic limit. This packing fraction
corresponds to the previously measured value for random close-packing. In fact,
our results provide a well-defined meaning for "random close-packing" in terms
of the fraction of all phase space with inherent structures that jam. The
jamming threshold, Point J, occurring at zero temperature and applied stress
and at the random close-packing density, has properties reminiscent of an
ordinary critical point. As Point J is approached from higher packing
fractions, power-law scaling is found for many quantities. Moreover, near Point
J, certain quantities no longer self-average, suggesting the existence of a
length scale that diverges at J. However, Point J also differs from an ordinary
critical point: the scaling exponents do not depend on dimension but do depend
on the interparticle potential. Finally, as Point J is approached from high
packing fractions, the density of vibrational states develops a large excess of
low-frequency modes. All of these results suggest that Point J may control
behavior in its vicinity-perhaps even at the glass transition.Comment: 21 pages, 20 figure
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