106 research outputs found
Exploration of the Eucalyptus globulus gene pool
The first Europeans to discover Eucalyptus
globulus were French explorers in 1792. Its seed
was rapidly spread throughout the world in the
19th century and this was the species by which
much of the world first knew the genus.
However, it was in the industrial forests of the
20th century that this species, once considered
the ‘Prince of Eucalypts’, achieved greatest
prominence due to its fast growth and superior
pulp qualities. Formal breeding first commenced
in 1966 in Portugal and in the late 1980’s large
base population trials from open-pollinated seed
collections from native stands were established
in many countries. These trials have provided
unprecedented insights into the quantitative
genetic control of numerous traits of economic
and ecological importance and how this variation
is spatially distributed in the native range of the
species. However with large, fully pedigreed
breeding populations becoming available for
quantitative analysis and the rapidly expanding
knowledge of DNA sequence variation, we are
now at the threshold of a new understanding of
this important eucalypt gene pool. Indications of
the significance of non-additive genetic effects
are becoming available. The E. globulus
chloroplast genome has now been sequenced
and several genome maps have been published.
Studies of the variation in nuclear microsatellites
and the lignin biosynthesis gene CCR confirm
the complex, spatially structured nature of the
native gene pool. Strong spatial structuring of
the chloroplast genome has provided a tool for
tracking seed migration and the geographic
origin of exotic landraces. Highly divergent
lineages of chloroplast DNA have been
discovered and studies of the hypervariable JLA+
region argue that some components of the E.
globulus gene pool have been assimilated from
other species following hybridisation
Rapid Detection and Subtyping of Human Influenza A Viruses and Reassortants by Pyrosequencing
Background: Given the continuing co-circulation of the 2009 H1N1 pandemic influenza A viruses with seasonal H3N2 viruses, rapid and reliable detection of newly emerging influenza reassortant viruses is important to enhance our influenza surveillance. Methodology/Principal Findings: A novel pyrosequencing assay was developed for the rapid identification and subtyping of potential human influenza A virus reassortants based on all eight gene segments of the virus. Except for HA and NA genes, one universal set of primers was used to amplify and subtype each of the six internal genes. With this method, all eight gene segments of 57 laboratory isolates and 17 original specimens of seasonal H1N1, H3N2 and 2009 H1N1 pandemic viruses were correctly matched with their corresponding subtypes. In addition, this method was shown to be capable of detecting reassortant viruses by correctly identifying the source of all 8 gene segments from three vaccine production reassortant viruses and three H1N2 viruses. Conclusions/Significance: In summary, this pyrosequencing assay is a sensitive and specific procedure for screening large numbers of viruses for reassortment events amongst the commonly circulating human influenza A viruses, which is mor
Relationship between cardiovascular risk factors and biomarkers with necrotic core and atheroma size: a serial intravascular ultrasound radiofrequency data analysis
We explored the impact of patient demographics, anthropometric measurements, cardiovascular risk factors, and soluble biomarkers on necrotic core and atheroma size in patients with coronary disease. The IBIS-2 trial enrolled 330 patients. In the multivariate analysis, at baseline, creatinine had a positive, whereas baseline mean lumen diameter and myeloperoxidase had a negative, independent association with percentage of necrotic core (PNC); while age, glomerular filtration rate <60, HbA1c, previous PCI or CABG and baseline % diameter stenosis were positively, and acute coronary syndromes (ACS) were negatively associated with baseline percentage atheroma volume (PAV). The variables associated with a decrease in PNC from baseline were darapladib, ACS and a large content of NC at baseline, while variables associated with an increase in PNC were previous stroke and % diameter stenosis at baseline. Those variables associated with a decrease in PAV from baseline were waist circumference, statin use, CD40L and baseline PAV, while the only variable associated with an increase in PAV was baseline diastolic blood pressure. Treatment with darapladib was associated with a decrease in necrotic core, but was not associated with a decrease in percentage atheroma volume. On the contrary, statin use was only associated with a decrease in percentage atheroma volume
Principles and Fundamentals of Optical Imaging
In this chapter I will give a brief general introduction to optical imaging and then discuss in more detail some of the methods specifically used for imaging cortical dynamics today. Absorption and fluorescence microscopy can be used to form direct, diffraction-limited images but standard methods are often only applicable to superficial layers of cortical tissue. Two-photon microscopy takes an intermediate role since the illumination pathway is diffraction-limited but the detection pathway is not. Losses in the illumination path can be compensated using higher laser power. Since the detection pathway does not require image formation, the method can substantially increase the imaging depth. Understanding the role of scattering is important in this case since non-descanned detection can substantially enhance the imaging performance. Finally, I will discuss some of the most widely used imaging methods that all rely on diffuse scattering such as diffuse optical tomography, laser speckle imaging, and intrinsic optical imaging. These purely scattering-based methods offer a much higher imaging depth, although at a substantially reduced spatial resolution
How do soil nutrients affect within-plant patterns of herbivory in seedlings of Eucalyptus nitens?
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