93,163 research outputs found
Mode coupling in solar spicule oscillations
In a real medium which has oscillations, the perturbations can cause the
energy transfer between different modes. The perturbation interpreted as an
interaction between the modes is inferred as mode coupling. Mode coupling
process in an inhomogeneous medium such as solar spicules may lead to the
coupling of kink waves to local Alfven waves. This coupling occurs practically
in any conditions when there is smooth variation in density in the radial
direction. This process is seen as the decay of transverse kink waves in the
medium. To study the damping of kink waves due to mode coupling, a
2.5-dimensional numerical simulation of the initial wave is considered in
spicules. The initial perturbation is assumed to be in a plane perpendicular to
the spicule axis. The considered kink wave is a standing wave which shows an
exponential damping in the inhomogeneous layer after occurrence of the mode
coupling
Riemannian Polyhedra and Liouville-type Theorems for Harmonic maps
This paper is a study of harmonic maps from Riemannian polyhedra to (locally)
non-positively curved geodesic spaces in the sense of Alexandrov. We prove
Liouville-type theorems for subharmonic functions and harmonic maps under two
different assumptions on the source space. First we prove the analogue of the
Schoen-Yau Theorem on a complete (smooth) pseudomanifolds with non-negative
Ricci curvature. Then we study 2-parabolic admissible Riemannian polyhedra and
prove some vanishing results on them.Comment: References added. Minor typos fixe
Genomic resource development for a diploid mint: Mentha longifolia
This research project aimed to develop genomic resources needed to enable construction of a genetic linkage map of the diploid mint species Mentha longifolia. Such a map would facilitate identification of plant genes involved in resistance to Verticillium fungal infection. For this purpose, a small genomic library was constructed from germplasm accession CMEN 585, 279 genomic inserts were sequenced and annotated and 19 PCR primer pairs were designed and tested on two resistant and two susceptible accessions. The Cleaved Modified Polymorphic Sequence (CAPS) method of molecular marker genotyping was found to detect little variation between crossing parents CMEN 585 (resistant) and CMEN 584 (susceptible). Comparative sequencing of PCR products from two European and two South African accessions revealed greater diversity between than within geographic locations. Future efforts should focus on assessing more sensitive genotyping methods, and developing a mapping population from a cross between European and South African accessions
Risk assessment of genetically modified food and neoliberalism: An argument for democratizing the regulatory review protocol of the Food and Drug Administration
The primary responsibility of the US Food and Drug Administration is to protect public health by ensuring the safety of the food supply. To that end, it sometimes conducts risk assessments of novel food products, such as genetically modified food. The FDA describes its regulatory review of GM food as a purely scientific activity, untainted by any normative considerations. This paper provides evidence that the regulatory agency is not justified in making that claim. It is argued that the FDA’s policy stance on GM food is shaped by neoliberal considerations. The agency’s review of a genetically engineered animal, the AquAdvantage salmon, is used as a case study to track the influence of neoliberalism on its regulatory review protocol. After that, an epistemic argument justifying public engagement in the risk assessment of new GM food is outlined. It is because risk evaluations involve normative judgments, in a democracy, layperson representatives of informal epistemic communities that could be affected by a new GM food should have the opportunity to decide the ethical, political or other normative questions that arise during the regulatory review of that entit
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