11,257 research outputs found
Brief Resume of Seiberg-Witten Theory
Talk presented by the second author at the Inaugural Coference of the Asia
Pacific Center for Theoretical Physics, Seoul, June 1996. The purpose of this
note is to give a resume of the Seiberg-Witten theory in the simplest possible
mathematical terms.Comment: 10 pages, LaTe
Reducing the hypoxic fraction of a tumour model by growth in low glucose.
The question of whether growth under low glucose conditions leads to a reduced amount of cell hypoxia was investigated using an in vitro tumour analogue, the sandwich system. In this multicellular system, the interplay between diffusion and consumption of oxygen and nutrients results in spatial gradients of these environmental factors. Gradients in the environment lead to biological heterogeneity within the cell population. A necrotic centre, surrounded by a viable cell border, subsequently develops. Cells adjacent to the necrotic centre in sandwiches are hypoxic and are in an environment somewhat analogous to that of cells adjacent to necrotic regions in solid tumours. Using sandwiches of the 9L and V79 cell lines, the effects of growth under low glucose conditions on the degree of hypoxia in regions adjacent to the necrotic centre were investigated. Per-cell binding of 3H-misonidazole, assessed by autoradiography, was used as an indicator of oxygen deprivation. It was found that the extent of the hypoxic region and the severity of hypoxia were considerably reduced by growing sandwiches in a glucose concentration of 0.6 mM rather than 6.5 mM. This reduction was found in conjunction with a smaller viable border; it occurred despite the fact that the average per-cell oxygen consumption is higher in the low glucose sandwiches. The data are qualitatively consistent with a joint oxygen-glucose deprivation model for cell necrosis
The UN local communities and Indigenous peoples' platform: A traditional ecological knowledge-based evaluation
This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium,
provided the original work is properly cited.
© 2019 The Authors. WIREs Climate Change published by Wiley Periodicals, Inc.This review evaluates the potential of the proposed local communities and Indigenous peoplesâ platform to effectively engage traditional ecological knowledge (TEK) for climate policy. Specifically, we assess the platform's potential to enable greater representation and participation of Indigenous peoples (IPs) within the United Nations Framework Convention on Climate Change (UNFCCC). An analytical
framework based on the extensive TEK and environmental management literature is developed, with a set of criteria identified against which to evaluate the platform. We find that although the process of designing the platform appears to be inclusive of Indigenous views, the structure itself does not recognize the roles that unequal power relations and colonialism play in marginalizing IPs. Limited attention
is paid to the institutional barriers within the UNFCCC and the drawbacks of pursuing knowledge âintegrationâ as an end in itself. Based on this, recommendations for improving the platform structure are put forward including using a rights based framing, giving greater decision-making power to IPs, and developing mechanisms to ensure the holistic integrity of TEK and build the overall resilience of climate mitigation and adaptation systems.Ye
CP Violation and Arrows of Time Evolution of a Neutral or Meson from an Incoherent to a Coherent State
We study the evolution of a neutral meson prepared as an incoherent equal
mixture of and . Denoting the density matrix by \rho(t) =
{1/2} N(t) [\1 + \vec{\zeta}(t) \cdot \vec{\sigma} ] , the norm of the state
is found to decrease monotonically from one to zero, while the magnitude
of the Stokes vector increases monotonically from zero to
one. This property qualifies these observables as arrows of time. Requiring
monotonic behaviour of for arbitrary values of and
yields a bound on the CP-violating overlap , which is similar to, but weaker than, the known unitarity
bound. A similar requirement on yields a new bound,
which is particularly effective in limiting
the CP-violating overlap in the - system. We obtain the Stokes
parameter which shows how the average strangeness of the beam
evolves from zero to . The evolution of the Stokes vector from
to has a resemblance to an order
parameter of a system undergoing spontaneous symmetry breaking.Comment: 13 pages, 6 figures. Inserted conon "." in title; minor change in
text. To appear in Physical review
A hydraulically actuated safety device
A hydraulically actuated safety device has been built and has proved effective in reducing accidental, premature operation of oceanographic samplers. It consists of a cylinder, a piston, and a shear actuated by the piston. Increasing hydrostatic pressure acting on one side of the piston shears a pin at a predetermined depth, thus arming instruments sensitive to sudden motion
The Language Question in a Rainbow Nation: The South African Experience
In this, the twenty-second annual Horace E. Read Memorial Lecture, Mr. Justice Albie Sachs reviews the efforts to resolve problems of multilingualism in the new Constitution of South Africa. Writing from experience in the constitution-making process, he reflects on the reality of eleven different languages in South Africa. He discusses the consequent problems of legislative strategy and linguistic rights and the appropriate balance amongst language rights, policy and practice
A tension recorder for deep-sea dredging and coring
The use of a tension meter or dynamometer for deep-sea dredging and coring is common practice on oceanographic vessels (Sigsbee 1880: 159â160, Thomson and Murray 1885: 61â63, Soule 1949: 49â50, Kullenberg 1955). However, in deep water, variations in wire tension that indicate bottom contact are frequently masked by the background of tension fluctuations due to the ship\u27s motion...
Climate, Water Navigability, and Economic Development
Geographic information systems (GIS) data was used on a global scale to examine the relationship between climate (ecozones), water navigability, and economic development in terms of GDP per capita. GDP per capita and the spatial density of economic activity measured as GDP per km2 are high in temperate ecozones and in regions proximate to the sea (within 100 km of the ocean or a sea-navigable waterway). Temperate ecozones proximate to the sea account for 8 percent of the worldâs inhabited land area, 23 percent of the worldâs population, and 53 percent of the worldâs GDP. The GDP densities in temperate ecozones proximate to the sea are on average eighteen times higher than in non-proximate non-temperate areas.
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