Mojave Applied Ecology Notes Fall 2009

USDA working to manage invasive annual grasses, effects of heat and smoke on red brome soil seed bank, how burial depth and substrate affect germination of Sahara mustard and red brome, environmental effects of the southern Nevada groundwater projec

Final report on interrelationships between chemical, physical and biological conditions of the waters of Las Vegas Bay of Lake Mead

This program was a status study of the interaction between Las Vegas Wash, an enriched stream, and Las Vegas Bay, a wedge shaped arm of one of the world\u27s deeper reservoirs. The program centered primarily on identification and counting of planktonic algae from several points in Las Vegas Bay. Additional work on nutrient enrichment of water samples was conducted to aid in interpretation of algal distribution related to nutrient input. Examination of a variety of physical, chemical, and biological parameters, both at many surface points in the bay, as well as in vertical profile, was also accomplished and further aided interpretation of nutrient cycling, sources of nutrient input and other limnological events commonly associated with the process of eutrophication. One copy of data is provided as an appendix to this report. Other copies are available on request. An intensive sampling program has been the core of the project. Fifteen stations were located to provide an early warning network for detection of directed movement of water bodies or strata in the bay, reliability in evaluation of surface plankton distributions, and reference points for exploitation of unanticipated opportunities. These stations were visited approximately weekly during the contract period for plankton samples to evaluate biologically-induced or biologically - responsive changes as cumulative indices of the chemical status of the system. Evaluation of results was aided by determinations of depth profiles of the standard limnological parameters: temperature, a measure of the degree of stratification or mixing of a lake, oxygen, pH and oxidation-reduction potential. Conductivity, to identify isothermal yet saline discontinuities and especially the location of the flow from Las Vegas Wash, was also measured. Colonies or unicellular plankton were counted to determine distribution versus time over the bay surface. Distribution and density, rather than productivity, was of primary interest; although evidence for growth or accumulation at given points was also obtained. Chemical analyses for principal anions and cations (such as sulfate, chloride, sodium and potassium) and major nutrients (such as phosphate) were performed in cooperation with Desert Research Institute and Environmental Protection Agency. Counts of total and coliform bacteria were made on samples from vertical profiles at various times to establish the reason for the pattern of oxygen depletion found

A review of the Schizobasis group of Drimia Jacq. (Hyacinthaceae: Urgineoideae), and the new species D. sigmoidea from Western Cape, South Africa

AbstractWe review the Schizobasis Baker group of Drimia Jacq. in southern Africa. We adopt a broad circumscription of D. intricata (Baker) J.C.Manning & Goldblatt as occurring widely through the summer-rainfall parts of southern and tropical Africa, and describe a second species, D. sigmoidea J.C.Manning & J.Deacon, for populations from the Worcester–Robertson Karoo in winter-rainfall Western Cape. It is distinguished from D. intricata by its distinctive, deflexed pedicels that are sharply sigmoid in fruit, and conspicuous anther connective appendage. Both species are fully described and illustrated, with a map of their distribution in southern Africa

Mediatization: key concept or conceptual bandwagon?

Mediatization is emerging as an influential new concept that places the media at the centre of all kinds of important cultural, political and social developments. However, it has so far attracted little critical evaluation. In this article the authors identify three areas of concern, namely, how causal processes are thought about, how historical change is understood, and how concepts are designed. It is hoped this article will generate critical debate and reflection to prevent the term from being applied so inconsistently and indiscriminately that it becomes a ‘concept of no difference’

'Mediatization and' or 'Mediatization of'? A response to Hepp et al.

We welcome Hepp et al.’s (2015) response to our recent critique of the concept of ‘Mediatization’ (Deacon and Stanyer, 2014), which they also use to showcase new literature on this topic. Their article demonstrates why further robust debate on this matter is needed. For when internationally renowned academics start to declare ‘paradigmatic shifts’, then a much wider community of scholars need to consider whether or not the earth is moving for them (see Hepp et al., 2015: 314–315, 321)

Transient phenomena in learning and evolution: genetic assimilation and genetic redistribution

Deacon has recently proposed that complexes of genes can be integrated into functional groups as a result of environmental changes that mask and unmask selection pressures. For example, many animals endogenously synthesize ascorbic acid (vitamin C), but anthropoid primates have only a nonfunctional version of the crucial gene for this pathway. It is hypothesized that the loss of functionality occurred in the evolutionary past when a diet rich in vitamin C masked the effect of the gene, and its loss effectively trapped the animals in a fruit-eating lifestyle. As a result, the complex of abilities that support this lifestyle were evolutionarily bound together, forming a multilocus complex. In this study we use evolutionary computation simulations to explore the thesis that masking and unmasking can transfer dependence from one set of genes to many sets, and thereby integrate the whole complex of genes. We used a framework based on Hinton and Nowlan's 1987 simulation of the Baldwin effect. Additional gene complexes and an environmental parameter were added to their basic model, and the fitness function extended. The simulation clearly demonstrates that the genetic redistribution effect can occur in silico, showing an initial advantage of endogenously synthesized vitamin C, followed by transfer of the fitness contribution to the complex of genes that together allow the acquisition of vitamin C from the environment. As is well known in the modeling community, the Baldwin effect only occurs in simulations when the population of agents is "poised on the brink" of discovering the genetically specified solution. Similarly, the redistribution effect occurs in simulations under specific initial conditions: too little vitamin C in the environment, and its synthesis it is never fully masked; too much vitamin C, and the abilities required to acquire it are not tightly integrated. The Baldwin effect has been hypothesized as a potential mechanism for developing language-specific adaptations like innate universal grammar and other highly modular capacities. We conclude with a discussion of the relevance of genetic assimilation and genetic redistribution to the evolution of language and other cognitive adaptations

Advances in Deep Space Exploration via Simulators & Deep Learning

The NASA Starlight and Breakthrough Starshot programs conceptualize fast interstellar travel via small relativistic spacecraft that are propelled by directed energy. This process is radically different from traditional space travel and trades large and slow spacecraft for small, fast, inexpensive, and fragile ones. The main goal of these wafer satellites is to gather useful images during their deep space journey. We introduce and solve some of the main problems that accompany this concept. First, we need an object detection system that can detect planets that we have never seen before, some containing features that we may not even know exist in the universe. Second, once we have images of exoplanets, we need a way to take these images and rank them by importance. Equipment fails and data rates are slow, thus we need a method to ensure that the most important images to humankind are the ones that are prioritized for data transfer. Finally, the energy on board is minimal and must be conserved and used sparingly. No exoplanet images should be missed, but using energy erroneously would be detrimental. We introduce simulator-based methods that leverage artificial intelligence, mostly in the form of computer vision, in order to solve all three of these issues. Our results confirm that simulators provide an extremely rich training environment that surpasses that of real images, and can be used to train models on features that have yet to be observed by humans. We also show that the immersive and adaptable environment provided by the simulator, combined with deep learning, lets us navigate and save energy in an otherwise implausible way

The contribution of knowledge management practices in generating a corporate culture of innovation

Organisations in all spheres of industries are facing constant change and need to be innovative to carve out a competitive market share. Knowledge is universally recognised as the organisation’s most valuable asset and strategic resource. The competitive business environment is impelling organisations to utilise and strengthen their knowledge capital in order to manage these changes. The relationship between knowledge management and innovation is not well understood and there is a need to explicitly examine this relationship explicitly. The objective of this study is to focus on the internal environment of listed companies in South Africa and determine to what extent knowledge management practices can contribute to an organisational culture of innovation and whether or not these practices are antecedents to innovative behaviour by knowledge workers Senior members in these companies were contacted by email and requested to access a questionnaire that was available via a Web address and complete the questionnaire. All completed questionnaires were analysed, using Item analysis, multiple regression and discriminant analysis. Results show that knowledge management practices: the organisation's science and technology human capital profile and the organisation is flexible and opportunistic are important predictors of innovativeness in organisations that are perceived to have an organisational culture of innovation.Graduate School of Business LeadershipM.B.L

Final report: Lake Mead monitoring program

The Lake Mead Monitoring Program has continued to develop information on the limnological condition of Lake Mead. We have significantly increased our analytical capabilities this year by developing a cooperative project with the U.S. Bureau of Reclamation and continuing our cooperative program with E.P.A. We also were able to derive significant benefit from the reviews of the Pollution Abatement Project written by Clair Sawyer and Charles Goldman. Partially as a result of these reviews we have had the opportunity to interpret and more fully explain the significance of our work to a wider public audience than would otherwise have been possible. Among the important issues that have been of primary interest this year are: 1. The significance, extent and effect on nutrient distribution of a density current from Las Vegas Wash. 2. The significance of lake level on algal abundance and productivity in Las Vegas Bay. 3. The probably effects of the AWT plant on algal abundance and productivity in Las Vegas Bay. This report more fully explains the data available on the density current and shows that the current becomes completely dissipated and mixed with waters of Las Vegas Bay, usually within the middle portion of the Bay. The influence of lake level on algal abundance is also examined with evidence supporting a hypothesis that higher lake levels result in lower algal populations. While we do not have accurate data on water volumes in Las Vegas Bay at various lake levels, rough calculations suggest that rising lake levels since 1972 have in fact resulted in a greater dilution of the inflowing nutrients from Las Vegas Wash. In effect the higher water levels have probably resulted in improved conditions in the lake because the nutrient inflows have actually become increasingly diluted in Las Vegas Bay since 1972. This is basically the same effect that would result by removing nutrients from an inflowing stream if lake level remained stable. A series of bioassays were performed to attempt a reasonable prediction of the probable effects of phosphorous removal on algal growth in Las Vegas Bay. Because of a number of variables, we did not obtain a quantitative estimate of the effect of phosphorous removal on algal growth in the bay. We did demonstrate however that reduction in phosphorous inflow will result in reduction of algal growth in Las Vegas Bay, if the bioassay procedures have approximately simulated conditions in Las Vegas Bay. Additional experimentation is necessary to approach a quantitative model of the effects of phosphorous removal on algal production in Lake Mead. Again we believe the value of the monitoring program has been demonstrated. Without the long-term data base provided by the Lake Mead Monitoring Program, the public discussion that has resulted from the interest created by AWT construction would have been forced to rely on short-term investigations, interpretation by interested and concerned laymen or emotional argument by individuals or organizations with special interests