112 research outputs found
The isolation of Leptospira interrogans serovar pomona and related serological findings associated with a mixed farming unit in the Transvaal
This is the first known isolation in the Republic of South Africa (RSA) of the serovar pomona from the organs of porcine foetuses as well as from the renal lymphnodes of slaughter pigs showing chronic nephritis. In addition, the serovar pomona was isolated from the kidneys of 87,5 % of the slaughter pigs examined. The success of these isolations was attributed in part to the refining of 2 existing isolation techniques which complement each other. Using the microscopic agglutination test, serum samples taken from the same farming unit showed evidence of antibodies to the serovar pomona in 89 out of the 170 bovines (52 %), 9 out of the 52 porcines (17 %), 2 of the 2 canines (100 %), 5 out of the 13 equines (38 %) and 2 out of the 152 ovines (1 %) that were tested. As far as is known, serological evidence of the serovar pomona in porcines, ovines, equines and canines has never previously been published in the RSA.The articles have been scanned in colour with a HP Scanjet 5590; 600dpi.
Adobe Acrobat XI Pro was used to OCR the text and also for the merging and conversion to the final presentation PDF-format.lmchunu2014mn201
Nonsingular instantons for the creation of open universes
We show that the instability of the singular Vilenkin instanton describing
the creation of an open universe can be avoided using, instead of a minimally
coupled scalar field, an axionic massless scalar field which gives rise to the
Giddings-Strominger instanton. However, if we replace the singularity of the
Hawking Turok instanton for an axionic wormhole some interpretational and
technical difficulties would appear which can be overcome by introducing a
positive cosmological constant in the action. This would make the instanton
finite and free constant in the action. This would make the instanton finite
and free from any instabilities.Comment: 8 pages, RevTex. A new section on the instantonic global structure
and a figure have been added. To appear in Phys. Rev.
Phenomenology of -CDM model: a possibility of accelerating Universe with positive pressure
Among various phenomenological models, a time-dependent model is selected here to investigate the -CDM cosmology.
Using this model the expressions for the time-dependent equation of state
parameter and other physical parameters are derived. It is shown that
in model accelerated expansion of the Universe takes place at negative
energy density, but with a positive pressure. It has also been possible to
obtain the change of sign of the deceleration parameter during cosmic
evolution.Comment: 16 Latex pages, 11 figures, Considerable modifications in the text;
Accepted in IJT
Gravitomagnetic Effects in the Propagation of Electromagnetic Waves in Variable Gravitational Fields of Arbitrary-Moving and Spinning Bodies
Propagation of light in the gravitational field of self-gravitating spinning
bodies moving with arbitrary velocities is discussed. The gravitational field
is assumed to be "weak" everywhere. Equations of motion of a light ray are
solved in the first post-Minkowskian approximation that is linear with respect
to the universal gravitational constant . We do not restrict ourselves with
the approximation of gravitational lens so that the solution of light geodesics
is applicable for arbitrary locations of source of light and observer. This
formalism is applied for studying corrections to the Shapiro time delay in
binary pulsars caused by the rotation of pulsar and its companion. We also
derive the correction to the light deflection angle caused by rotation of
gravitating bodies in the solar system (Sun, planets) or a gravitational lens.
The gravitational shift of frequency due to the combined translational and
rotational motions of light-ray-deflecting bodies is analyzed as well. We give
a general derivation of the formula describing the relativistic rotation of the
plane of polarization of electromagnetic waves (Skrotskii effect). This formula
is valid for arbitrary translational and rotational motion of gravitating
bodies and greatly extends the results of previous researchers. Finally, we
discuss the Skrotskii effect for gravitational waves emitted by localized
sources such as a binary system. The theoretical results of this paper can be
applied for studying various relativistic effects in microarcsecond space
astrometry and developing corresponding algorithms for data processing in space
astrometric missions such as FAME, SIM, and GAIA.Comment: 36 pages, 1 figure, submitted to Phys. Rev.
Can forest management based on natural disturbances maintain ecological resilience?
Given the increasingly global stresses on forests, many ecologists argue that managers must maintain ecological resilience: the capacity of ecosystems to absorb disturbances without undergoing fundamental change. In this review we ask: Can the emerging paradigm of natural-disturbance-based management (NDBM) maintain ecological resilience in managed forests? Applying resilience theory requires careful articulation of the ecosystem state under consideration, the disturbances and stresses that affect the persistence of possible alternative states, and the spatial and temporal scales of management relevance. Implementing NDBM while maintaining resilience means recognizing that (i) biodiversity is important for long-term ecosystem persistence, (ii) natural disturbances play a critical role as a generator of structural and compositional heterogeneity at multiple scales, and (iii) traditional management tends to produce forests more homogeneous than those disturbed naturally and increases the likelihood of unexpected catastrophic change by constraining variation of key environmental processes. NDBM may maintain resilience if silvicultural strategies retain the structures and processes that perpetuate desired states while reducing those that enhance resilience of undesirable states. Such strategies require an understanding of harvesting impacts on slow ecosystem processes, such as seed-bank or nutrient dynamics, which in the long term can lead to ecological surprises by altering the forest's capacity to reorganize after disturbance
Short-term changes in median nerve neural tension after a suboccipital muscle inhibition technique in subjects with cervical whiplash: A randomised controlled trial.
Objectives To assess the immediate effect of a suboccipital muscle inhibition (SMI) technique on: (a) neck pain, (b) elbow extension rangeof motion during the upper limb neurodynamic test of the median nerve (ULNT-1), and (c) grip strength in subjects with cervical whiplash;and determine the relationships between key variables.Design Randomised, single-blind, controlled clinical trial.Setting Faculty of Nursing, Physiotherapy and Podiatry, University of Seville, Spain.Participants Forty subjects {mean age 34 years [standard deviation (SD) 3.6]} with Grade I or II cervical whiplash and a positive responseto the ULNT-1 were recruited and distributed into two study groups: intervention group (IG) (n = 20) and control group (CG) (n = 20).Interventions The IG underwent the SMI technique for 4 minutes and the CG received a sham (placebo) intervention. Measures were collectedimmediately after the intervention.Main outcome measures The primary outcome was elbow range of motion during the ULNT-1, measured with a goniometer. The secondaryoutcomes were self-perceived neck pain (visual analogue scale) and free-pain grip strength, measured with a digital dynamometer.Results The mean baseline elbow range of motion was 116.0âŠ(SD 10.2) for the CG and 130.1âŠ(SD 7.8) for the IG. The within-groupcomparison found a significant difference in elbow range of motion for the IG [mean difference â15.4âŠ, 95% confidence interval (CI) â20.1to â10.6; P = 0.01], but not for the CG (mean difference â4.9âŠ, 95% CI â11.8 to 2.0; P = 0.15). In the between-group comparison, thedifference in elbow range of motion was significant (mean difference â10.5âŠ, 95% CI â18.6 to â2.3; P = 0.013), but the differences in gripstrength (P = 0.06) and neck pain (P = 0.38) were not significant.Conclusion The SMI technique has an immediate positive effect on elbow extension in the ULNT-1. No immediate effects on self-perceivedcervical pain or grip strength were observed
Applications De La Theorie Des Jeux A L'Education: Pour Quels Types Et Niveaux D'Education, Quels Modeles, Quels Resultats?
Potential for biological nitrification inhibition to reduce nitrification and N2O emissions in pasture cropâlivestock systems
Genetic variability of drought-avoidance root traits in the mini-core germplasm collection of chickpea (Cicer arietinum L.).
Extensive and deep root systems have been recognized as one of the most important traits for improving chickpea (Cicer arietinum L.) productivity under progressively receding soil moisture conditions. However, available information on the range of variation for root traits is still limited. Genetic variability for the root traits was investigated using a cylinder culture system during two consecutive growth seasons in the mini-core germplasm collection of ICRISAT plus several wild relatives of chickpea. The largest genetic variability was observed at 35 days after sowing for root length density (RLD) (heritability, h 2 = 0.51 and 0.54) across seasons, and followed by the ratio of plant dry weight to root length density with h 2 of 0.37 and 0.50 for first and second season, respectively. The root growth of chickpea wild relatives was relatively poor compared to C. arietinum, except in case of C. reticulatum. An outstanding genotype, ICC 8261, which had the largest RLD and one of the deepest root system, was identified in chickpea mini-core germplasm collection. The accession ICC 4958 which was previously characterized as a source for drought avoidance in chickpea was confirmed as one with the most prolific and deep root system, although many superior accessions were also identified. The chickpea landraces collected from the Mediterranean and the west Asian region showed a significantly larger RLD than those from the south Asian region. In addition, the landraces originating from central Asia (former Soviet Union), characterized by arid agro-climatic conditions, also showed relatively larger RLD. As these regions are under-represented in the chickpea collection, they might be interesting areas for further germplasm exploration to identify new landraces with large RLD. The information on the genetic variability of chickpea root traits provides valuable baseline knowledge for further progress on the selection and breeding for drought avoidance root traits in chickpea
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