Adsorption spectrum of thulium sulphate octahydrate

The term splitting of the absorption spectrum of thulium sulphate octalhydrate due to crystal field effects was calculated according to first order perturbation theory. Departures from Russell-Saunders Coupling were taken into account. The various transition mechanisms were examined with and without crystal coupling. It was found that crystal coupling effects are important in destroying J and parity selection rules. Transitions induced by these effects are often more important than transitions calculated neglecting crystal coupling. Zeeman patterns were also studied for the several interesting directions of propagation and polarization of the light relative to the magnetic field directione Susceptibility calculations made for thulium, praseodymium and neodymium sulphate octahydrate indicate field calculations cannot always be made neglecting all but nearest neighbor contributions

Foolishness : Kidder

https://digitalcommons.library.umaine.edu/mmb-vp/1467/thumbnail.jp

Geochemistry of quaternary, rift-related volcanism in the Bransfield Strait, Antarctica

The Bransfield Strait is the narrow, late Tertiary to Quaternary marginal basin separating the South Shetland Islands from the northern end of the Antarctic Peninsula magmatic arc. Quaternary volcanism in the strait is tholeiitic to mildly alkaline, and contrasts chemically with the pre-Quaternary calc-alkaline arc volcanism. Geochemical evidence presented here shows that the Quaternary volcanism is related to active rifting in the strait. All of the rift-related volcanoes are chemically related by different extents of partial melting of garnet peridotite variably enriched in alkali and alkali earth elements relative to rare earth elements. This enrichment is characteristic of subduction zones, where fluids from the dehydrating subducted slab concentrate alkalies and alkali earths that can then be mixed into, and partially melted with, the surrounding mantle. The lavas that erupted during the formation of the Bransfield Strait provide evidence that subduction zone processes influence the chemistry of marginal basin volcanism. The Bransfield Strait lavas are chemically similar to published analyses from other marginal basins, especially the Cretaceous marginal basin that is now preserved as the Sarmiento ophiolite of southern Chile. This confirms the interpretation that, prior to obduction, the Sarmiento was a narrow, immature marginal basin analogous to the present day Bransfield Strait

Experimentally heat‐induced transposition increases drought tolerance in Arabidopsis thaliana

Eukaryotic genomes contain a vast diversity of transposable elements (TEs). Formerly often described as selfish and parasitic DNA sequences, TEs are now recognized as a source of genetic diversity and powerful drivers of evolution. Yet, because their mobility is tightly controlled by the host, studies experimentally assessing how fast TEs may mediate the emergence of adaptive traits are scare. We exposed Arabidopsis thaliana high-copy TE lines (hcLines) with up to ~8 fold increased copy numbers of the heat-responsive ONSEN TE to drought as a straightforward and ecologically highly relevant selection pressure. We provide evidence for increased drought tolerance in five out of the 23 tested hcLines and further pinpoint one of the causative mutations to an exonic insertion of ONSEN in the ribose-5-phosphate-isomerase 2 gene. The resulting loss-of-function mutation caused a decreased rate of photosynthesis, plant size and water consumption. Overall, we show that the heat-induced transposition of a low-copy TE increases phenotypic diversity and leads to the emergence of drought-tolerant individuals in Arabidopsis thaliana. This is one of the rare empirical examples substantiating the adaptive potential of mobilized stress-responsive TEs in eukaryotes. Our work demonstrates the potential of TE-mediated loss-of-function mutations in stress adaptation

Cenozoic paleoceanography 1986: An introduction

New developments in Cenozoic paleoceanography include the application of climate models and atmospheric general circulation models to questions of climate reconstruction, the refinement of conceptual models for interpretation of the carbon isotope record in terms of carbon mass balance, paleocirculation, paleoproductivity, and the regional mapping of paleoceanographic events by acoustic stratigraphy. Sea level change emerges as a master variable to which changes in the ocean environment must be traced in many cases, and tests of the onlap-offlap paradigm therefore are of crucial importance

A Calculus of Purpose

Biological systems are so complex that we must ask: "What purpose does all this complexity serve?" Lander argues that computational biology may help provide answer

Banner News

https://openspace.dmacc.edu/banner_news/1287/thumbnail.jp

Space-Time Approach to Scattering from Many Body Systems

We present scattering from many body systems in a new light. In place of the usual van Hove treatment, (applicable to a wide range of scattering processes using both photons and massive particles) based on plane waves, we calculate the scattering amplitude as a space-time integral over the scattering sample for an incident wave characterized by its correlation function which results from the shaping of the wave field by the apparatus. Instrument resolution effects - seen as due to the loss of correlation caused by the path differences in the different arms of the instrument are automatically included and analytic forms of the resolution function for different instruments are obtained. The intersection of the moving correlation volumes (those regions where the correlation functions are significant) associated with the different elements of the apparatus determines the maximum correlation lengths (times) that can be observed in a sample, and hence, the momentum (energy) resolution of the measurement. This geometrical picture of moving correlation volumes derived by our technique shows how the interaction of the scatterer with the wave field shaped by the apparatus proceeds in space and time. Matching of the correlation volumes so as to maximize the intersection region yields a transparent, graphical method of instrument design. PACS: 03.65.Nk, 3.80 +r, 03.75, 61.12.BComment: Latex document with 6 fig

Requirements for a Software Maintenance Methodology

Software maintenance, although widely recognized as the most costly period in the life of a system, is given only passing consideration in life-cycle models. An extensive literature review shows the relationship between the development and maintenance phases to be ignored to a large extent. The Abstraction Refinement Model (ARM) describes the dependency of software maintenance on the quality of the documentation and depicts the adaptive and perfective maintenance forms as relying on earlier design and requirements documents to a greater degree than corrective and preventative maintenance. The ARM is effective in laying the foundations for a software maintenance methodology, particularly in explaining the role of reverse engineering. Coupling the ARM with the Objectives/Principles/Attributes procedure for the evaluation for software development methodologies proves effective in drawing the contrast with maintenance requirements. which are specifically identified for further study and assessment