74 research outputs found
Estimation of the solubility parameters of model plant surfaces and agrochemicals: a valuable tool for understanding plant surface interactions
Background
Most aerial plant parts are covered with a hydrophobic lipid-rich cuticle, which is the interface between the plant organs and the surrounding environment. Plant surfaces may have a high degree of hydrophobicity because of the combined effects of surface chemistry and roughness. The physical and chemical complexity of the plant cuticle limits the development of models that explain its internal structure and interactions with surface-applied agrochemicals. In this article we introduce a thermodynamic method for estimating the solubilities of model plant surface constituents and relating them to the effects of agrochemicals.
Results
Following the van Krevelen and Hoftyzer method, we calculated the solubility parameters of three model plant species and eight compounds that differ in hydrophobicity and polarity. In addition, intact tissues were examined by scanning electron microscopy and the surface free energy, polarity, solubility parameter and work of adhesion of each were calculated from contact angle measurements of three liquids with different polarities. By comparing the affinities between plant surface constituents and agrochemicals derived from (a) theoretical calculations and (b) contact angle measurements we were able to distinguish the physical effect of surface roughness from the effect of the chemical nature of the epicuticular waxes. A solubility parameter model for plant surfaces is proposed on the basis of an increasing gradient from the cuticular surface towards the underlying cell wall.
Conclusions
The procedure enabled us to predict the interactions among agrochemicals, plant surfaces, and cuticular and cell wall components, and promises to be a useful tool for improving our understanding of biological surface interactions
CHASE-PL Climate Projection dataset over Poland â bias adjustment of EURO-CORDEX simulations
The CHASE-PL (Climate change impact assessment for selected sectors in
Poland) Climate Projections â Gridded Daily Precipitation and Temperature
dataset 5âŻkm (CPLCP-GDPT5) consists of projected daily minimum and
maximum air temperatures and precipitation totals of nine EURO-CORDEX
regional climate model outputs bias corrected and downscaled to
a 5âŻkmâŻâĂââŻ5âŻkm grid. Simulations of one historical period
(1971â2000) and two future horizons (2021â2050 and 2071â2100) assuming two
representative concentration pathways (RCP4.5 and RCP8.5) were produced. We
used the quantile mapping method and corrected any systematic seasonal bias
in these simulations before assessing the changes in annual and seasonal
means of precipitation and temperature over Poland. Projected changes
estimated from the multi-model ensemble mean showed that annual means of
temperature are expected to increase steadily by 1âŻÂ°C until
2021â2050 and by 2âŻÂ°C until 2071â2100 assuming the RCP4.5
emission scenario. Assuming the RCP8.5 emission
scenario, this can reach up to almost 4âŻÂ°C by 2071â2100.
Similarly to temperature, projected changes in regional annual means of
precipitation are expected to increase by 6 to 10âŻ% and by 8 to
16âŻ% for the two future horizons and RCPs, respectively. Similarly,
individual model simulations also exhibited warmer and wetter conditions on
an annual scale, showing an intensification of the magnitude of the change at
the end of the 21st century. The same applied for projected changes in
seasonal means of temperature showing a higher winter warming rate by up to
0.5âŻÂ°C compared to the other seasons. However, projected
changes in seasonal means of precipitation by the individual models largely
differ and are sometimes inconsistent, exhibiting spatial variations which
depend on the selected season, location, future horizon, and RCP. The overall
range of the 90âŻ% confidence interval predicted by the ensemble of
multi-model simulations was found to likely vary between â7âŻ%
(projected for summer assuming the RCP4.5 emission scenario) and
+40âŻ% (projected for winter assuming the RCP8.5 emission scenario) by
the end of the 21st century. Finally, this high-resolution bias-corrected
product can serve as a basis for climate change impact and adaptation studies
for many sectors over Poland. The CPLCP-GDPT5 dataset is publicly available
at http://dx.doi.org/10.4121/uuid:e940ec1a-71a0-449e-bbe3-29217f2ba31d
Assessment of Skeletal Muscle Contractile Properties by Radial Displacement: The Case for Tensiomyography
Skeletal muscle operates as a near-constant volume system; as such muscle shortening during contraction is transversely linked to radial deformation. Therefore, to assess contractile properties of skeletal muscle, radial displacement can be evoked and measured. Mechanomyography measures muscle radial displacement and during the last 20 years, tensiomyography has become the most commonly used and widely reported technique among the various methodologies of mechanomyography. Tensiomyography has been demonstrated to reliably measure peak radial displacement during evoked muscle twitch, as well as muscle twitch speed. A number of parameters can be extracted from the tensiomyography displacement/time curve and the most commonly used and reliable appear to be peak radial displacement and contraction time. The latter has been described as a valid non-invasive means of characterising skeletal muscle, based on fibre-type composition. Over recent years, applications of tensiomyography measurement within sport and exercise have appeared, with applications relating to injury, recovery and performance. Within the present review, we evaluate the perceived strengths and weaknesses of tensiomyography with regard to its efficacy within applied sports medicine settings. We also highlight future tensiomyography areas that require further investigation. Therefore, the purpose of this review is to critically examine the existing evidence surrounding tensiomyography as a tool within the field of sports medicine
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