3,011 research outputs found
The Effects of Agonist-Antagonist Paired Set vs. Traditional Set Training on Forearm Strength
Please download pdf version here
Evaluating Cultivars of Subterranean Clover in Monoculture or with Perennial Ryegrass
Over four years, sowing perennial ryegrass (Lolium perenne) with a range of subterranean clover (âsub cloverâ, Trifolium subterraneum) cultivars was found to reduce the yield of clover per se by 31% and increase pasture yield by 11%. For one high-producing experimental variety, the presence of grass did not reduce clover yield (P\u3c0.001). Clover yield in monoculture plots was poorly correlated with that measured in mixed swards (r = 0.44), but clover yield (± grass) was correlated with total herbage yield (r = 0.94). Clover seed yield was not reduced by the presence of grass. However, in year 2 - but not in the establishment year - grass reduced seed weight. Irrespective of grass treatment, the new late maturing cultivar, Leura outyielded the other commercial cultivars (P\u3c0.05). Enfield and Enfield x Daliak crosses set the most seed and regenerated with a greater density than other cultivars (P\u3c0.05) - apart from Leura. It was concluded that the winter-active, late maturing cultivar, Leura, will compete most successfully with perennial ryegrass
Comparative Seed Strike of Temperate, Sub-Tropical and Native Grasses and Herb Species Under Contrasting Environments in Southern Australia
The role of deep-rooted perennials in reducing recharge to mitigate dryland salinity has been recognised widely in Australia recently. Poor seedling establishment is a key limiting factor for the expression of genetic merit for some perennial pasture species. Nie et al. (2004) investigated seedling establishment, and its relationship with rainfall and temperature, of a range of perennial grass and herb species in southern Australia. This paper reports seed strike of a range of perennial pasture species in 2 contrasting environments. There was significant interaction between species and site on seed strike. Environmental conditions caused different establishment outcomes within a diverse set of perennial forage species
Recommended from our members
The niche and forest growth
p.68-88 from Analysis of coniferous forest ecosystems in the Western United States
A ballistic motion disrupted by quantum reflections
I study a Lindblad dynamics modeling a quantum test particle in a Dirac comb
that collides with particles from a background gas. The main result is a
homogenization theorem in an adiabatic limiting regime involving large initial
momentum for the test particle. Over the time interval considered, the particle
would exhibit essentially ballistic motion if either the singular periodic
potential or the kicks from the gas were removed. However, the particle behaves
diffusively when both sources of forcing are present. The conversion of the
motion from ballistic to diffusive is generated by occasional quantum
reflections that result when the test particle's momentum is driven through a
collision near to an element of the half-spaced reciprocal lattice of the Dirac
comb.Comment: 54 pages. I rewrote the introduction and simplified some of the
presentatio
Diffusive limit for a quantum linear Boltzmann dynamics
In this article, I study the diffusive behavior for a quantum test particle
interacting with a dilute background gas. The model I begin with is a reduced
picture for the test particle dynamics given by a quantum linear Boltzmann
equation in which the gas particle scattering is assumed to occur through a
hard-sphere interaction. The state of the particle is represented by a density
matrix that evolves according to a translation-covariant Lindblad equation. The
main result is a proof that the particle's position distribution converges to a
Gaussian under diffusive rescaling.Comment: 51 pages. I have restructured Sections 2-4 from the previous version
and corrected an error in the proof of Proposition 7.
A translational approach for limb vascular delivery of the micro-dystrophin gene without high volume or high pressure for treatment of Duchenne muscular dystrophy
Background: Duchenne muscular dystrophy (DMD) is an X-linked recessive disorder with monogenic mutations
setting the stage for successful gene therapy treatment. We have completed a study that directly deals with the following
key issues that can be directly adapted to a gene therapy clinical trial using rAAV considering the following criteria: 1) A
regional vascular delivery approach that will protect the patient from widespread dissemination of virus; 2) an approach
to potentially facilitate safe passage of the virus for efficient skeletal muscle transduction; 3) the use of viral doses to
accommodate current limitations imposed by vector production methods; 4) and at the same time, achieve a clinically
meaningful outcome by transducing multiple muscles in the lower limb to prolong ambulation.
Methods: The capacity of AAV1, AAV6 or AAV8 to cross the vascular endothelial barrier carrying a micro-dystrophin
cDNA was compared under identical conditions with delivery through a catheter placed in the femoral artery of the mdx
mouse. Transduction efficiency was assessed by immuno-staining using an antibody (Manex1a) that recognizes the Nterminus
of micro-dystrophin. The degree of physiologic correction was assessed by measuring tetanic force and
protection from eccentric contraction in the extensor digitorum longus muscle (EDL). The vascular delivery paradigm
found successful in the mouse was carried to the non-human primate to test its potential translation to boys with DMD.
Results: Regional vascular delivery resulted in transduction by rAAV8.micro-dystrophin reaching 94.5 ± 0.9 (1 month),
91.3 ± 3.1 (2 months), and 89.6 ± 1.6% (3 months). rAAV6.micro-dystrophin treated animals demonstrated 87.7 ± 6.8
(1 month), 78.9 ± 7.4 (2 months), and 81.2 ± 6.2% (3 months) transduction. In striking contrast, rAAV1 demonstrated
very low transduction efficiency [0.9 ± 0.3 (1 month), 2.1 ± 0.8 (2 months), and 2.1 ± 0.7% (3 months)] by vascular
delivery. Micro-dystrophin delivered by rAAV8 and rAAV6 through the femoral artery significantly improved tetanic
force and protected against eccentric contraction. Mouse studies translated to the hindlimb of cynamologous macaques
using a similar vascular delivery paradigm. rAAV8 carrying eGFP in doses proportional to the mouse (5 Ă 1012 vg/kg in
mouse vs 2 Ă 1012 vg/kg in monkey) demonstrated widespread gene expression [medial gastrocnemius â 63.8 ± 4.9%,
lateral gastrocnemius â 66.0 ± 4.5%, EDL â 80.2 ± 3.1%, soleus â 86.4 ± 1.9%, TA â 72.2 ± 4.0%.
Conclusion: These studies demonstrate regional vascular gene delivery with AAV serotype(s) in mouse and non-human
primate at doses, pressures and volumes applicable for clinical trials in children with DMD
Recommended from our members
MP3 - A meteorology and physical properties package to explore air-sea interaction on Titan
The exchange of mass, heat and momentum at the air:sea interface are profound influences on the terrestrial environment, affecting the intensity of hurricanes, the size of waves and lake-effect precipitation. Titan presents us with an opportunity to study these processes in a novel physical context, with a different sea, atmosphere and gravity. The MP3 instrument, under development for the proposed Discovery mission TiME (Titan Mare Explorer [1,2]) is an integrated suite of small, simple sensors that combines the function of traditional meteorology packages with liquid physical properties and depth-sounding : these latter functions follow the concept of - and indeed use spare elements from - the Huygens Surface Science Package (SSP,[3]). However, unlike Huygensâ brief and dynamic 3 hours of measurement, in TiMEâs 6-Titan-day (96 Earth day) nominal mission enabled by radioisotope power, MP3 will have an unprecedented long-term measurement opportunity in one of the most evocative environments in the solar system, Titanâs sea Ligeia Mare
Two-band second moment model and an interatomic potential for caesium
A semi-empirical formalism is presented for deriving interatomic potentials
for materials such as caesium or cerium which exhibit volume collapse phase
transitions. It is based on the Finnis-Sinclair second moment tight binding
approach, but incorporates two independent bands on each atom. The potential is
cast in a form suitable for large-scale molecular dynamics, the computational
cost being the evaluation of short ranged pair potentials. Parameters for a
model potential for caesium are derived and tested
First Steps towards Underdominant Genetic Transformation of Insect Populations
The idea of introducing genetic modifications into wild populations of insects to stop them from spreading diseases is more than 40 years old. Synthetic disease refractory genes have been successfully generated for mosquito vectors of dengue fever and human malaria. Equally important is the development of population transformation systems to drive and maintain disease refractory genes at high frequency in populations. We demonstrate an underdominant population transformation system in Drosophila melanogaster that has the property of being both spatially self-limiting and reversible to the original genetic state. Both population transformation and its reversal can be largely achieved within as few as 5 generations. The described genetic construct {Ud} is composed of two genes; (1) a UAS-RpL14.dsRNA targeting RNAi to a haploinsufficient gene RpL14 and (2) an RNAi insensitive RpL14 rescue. In this proof-of-principle system the UAS-RpL14.dsRNA knock-down gene is placed under the control of an Actin5c-GAL4 driver located on a different chromosome to the {Ud} insert. This configuration would not be effective in wild populations without incorporating the Actin5c-GAL4 driver as part of the {Ud} construct (or replacing the UAS promoter with an appropriate direct promoter). It is however anticipated that the approach that underlies this underdominant system could potentially be applied to a number of species.
Figure
- âŠ