304 research outputs found
Blackleg of rapeseed
Unless blackleg can be controlled there is little future for rapeseed as a major commercial crop in W.A.
Until 1972, oilseed rape showed great promise as an alternative cash crop for Western Australian farmers, especially in the Great Southern and south coastal areas.
However, like most other cruciferous crops, rape is prone to attack from diseases and insect pests. Most of these can be controlled, but the fungus disease blackleg (Leptosphaeria maculans) emerged as a major threat to the industry.
Clearly, unless the disease can be controlled, there is little future for rapeseed as a major commercial crop in Western Australia
The viewing conditions of light-field video for subjective quality assessment
At the time of this paper, research on the quality of light-field visualization is continuously gaining momentum, as the excellence in visual performance shall be one of the key enablers of the emergence and long-Term presence of this technology on the consumer market. Experiments on perceived quality began in parallel with the appearance of commercially available light-field displays. As the techniques of subjective quality assessment on these displays are not standardized yet, certain parameters may greatly vary, such as viewing conditions. Although most of the current research efforts in this area address forms of static visualization, light-field video is also an essential target of quality evaluation. In this paper, we introduce the results of an experiment investigating the viewing conditions of light-field video quality assessment. The tests directly compare the perceived horizontal motion parallax of static viewing positions with motion patterns. The visual quality of the test conditions was degraded by the reduction of content spatial and angular resolution, as they both affect the smoothness of the horizontal motion parallax
Single-atom doping for quantum device development in diamond and silicon
The ability to inject dopant atoms with high spatial resolution, flexibility
in dopant species and high single ion detection fidelity opens opportunities
for the study of dopant fluctuation effects and the development of devices in
which function is based on the manipulation of quantum states in single atoms,
such as proposed quantum computers. We describe a single atom injector, in
which the imaging and alignment capabilities of a scanning force microscope
(SFM) are integrated with ion beams from a series of ion sources and with
sensitive detection of current transients induced by incident ions. Ion beams
are collimated by a small hole in the SFM tip and current changes induced by
single ion impacts in transistor channels enable reliable detection of single
ion hits. We discuss resolution limiting factors in ion placement and
processing and paths to single atom (and color center) array formation for
systematic testing of quantum computer architectures in silicon and diamond
Magic Numbers of Silicon Clusters
A structural model for intermediate sized silicon clusters is proposed that
is able to generate unique structures without any dangling bonds. This
structural model consists of bulk-like core of five atoms surrounded by
fullerene-like surface. Reconstruction of the ideal fullerene geometry results
in the formation of crown atoms surrounded by -bonded dimer pairs. This
model yields unique structures for \Si{33}, \Si{39}, and \Si{45} clusters
without any dangling bonds and hence explains why these clusters are least
reactive towards chemisorption of ammonia, methanol, ethylene, and water. This
model is also consistent with the experimental finding that silicon clusters
undergo a transition from prolate to spherical shapes at \Si{27}. Finally,
reagent specific chemisorption reactivities observed experimentally is
explained based on the electronic structures of the reagents.Comment: 4 pages + 3 figures (postscript files after \end{document}
Development of sperm vitrification protocols for freshwater fish (Eurasian perch, Perca fluviatilis) and marine fish (European eel, Anguilla anguilla)
[EN] Vitrification was successfully applied to the sperm of two fish species, the freshwater Eurasian perch (Perca fluviatilis) and marine European eel (Anguilla anguilla). Sperm was collected, diluted in species specific non-activating media and cryoprotectants and vitrified by plunging directly into liquid nitrogen without pre-cooling in its vapor. Progressive motility of fresh and vitrified-thawed sperm was evaluated with computer-assisted sperm analysis (CASA). Additional sperm quality parameters such as sperm head morphometry parameters (in case of European eel) and fertilizing capacity (in case of Eurasian perch) were carried out to test the effectiveness of vitrification. The vitrification method for Eurasian perch sperm resulting the highest post-thaw motility (14 +/- 1.6%) was as follows: 1:5 dilution ratio, Tanaka extender, 30% cryoprotectant (15% methanol + 15% propylene-glycol), cooling device: Cryotop, 2 mu l droplets, and for European eel sperm: dilution ratio 1:1, with 40% cryoprotectant (20% MeOH and 20% PG), and 10% FBS, cooling device: Cryotop, with 2 mu l of sperm suspension. Viable embryos were produced by fertilization with vitrified Eurasian perch sperm (neurulation: 2.54 +/- 1.67%). According to the ASMA analysis, no significant decrease in head area and perimeter of vitrified European eel spermatozoa were found when compared to fresh spermatozoa.The work was funded by the NKFI (previously OTKA) project number K-109847 and by a Short-term Scientific Mission awarded to E. Kasa by the COST Office (Food and Agriculture COST Action FA1205: Assessing and improving the quality of aquatic animal gametes to enhance aquatic resources. The need to harmonize and standardize evolving methodologies, and improve transfer from academia to industry; AQUAGAMETE). The work was supported by the project Research Center of Excellence - 9878-3/2016/FEKUT of the Ministry of Human Resources of Hungary and the project EUREKA_HU_12-1-2012-0056 (PERCAHATCH).Kása, E.; Bernáth, G.; Kollár, T.; Zarski, D.; Lujic, J.; Marinovic, Z.; Bokor, Z.... (2017). Development of sperm vitrification protocols for freshwater fish (Eurasian perch, Perca fluviatilis) and marine fish (European eel, Anguilla anguilla). General and Comparative Endocrinology. 245:102-107. https://doi.org/10.1016/j.ygcen.2016.05.010S10210724
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