Diffusion of geographic information innovations

Abstract

Appropriate diffusion of geographic information technologies is hampered by lack of systematic research on factors and processes affecting diffusion, utilization and impact assessment of the technologies and by a variety of conceptual and methodological problems. Diffusion of innovation principles developed in other fields, in combination with methods developed within the field of management information systems, provide an important beginning for improved understanding. This paper focuses on gaps in knowledge which might be addressed within the geographic information field by analysis techniques and research methodologies used in the diffusion of innovations.     

Temporal variations in night-time hydroxyl rotational temperature

Airborne and groundbased OH measurements showing short-term temporal variations in OH rotational temperature are presented. The variations are interpreted on the basis of a dynamic model of the OH emitting region; they are also employed to clarify the apparent contradiction in latitude dependence of OH intensity reported in the literature.     

Modeling the Pre-Euroamerican Landscape with Government Land Office Surveys and Geostatistics

Forested areas in the United States have been altered since the time of European settlement. There is increasing interest in comparing present day vegetation with that of the Pre-Euroamerican era to understand what changes have occurred in some of our more outstanding natural areas. Studies have been conducted using Government Land Office (GLO) notes to understand historic vegetation surveys, but past studies focused on species present/absent lists. The GLO surveys included information about tree species, tree diameter and other physical features. This study used indicator kriging to interpolate the probability of tree species on the landscape using the GLO data from 62 townships. Once continuous probability models were developed, vegetation spatial patterns were analyzed throughout the sub-basin. This technique provided insight into what the vegetation pattern (spatially) was like prior to Euroamerican settlement within the Buffalo River sub-basin. It provided the base information necessary to quantify vegetation change and the spatial extent of that change. Based on this research it appears that post-Euroamerican fire suppression and agricultural practices with other human activities have been major contributors to change. Eastern Redcedar ( Juniperious virginiana ) and hickory ( Carya sp .) have increased, while oak species ( Quercus sp .) have decreased. Additionally 19% of the sub-basin has changed to non-forest.     

Calculation of the relative metastabilities of proteins using the CHNOSZ software package

Background  

Proteins of various compositions are required by organisms inhabiting different environments. The energetic demands for protein formation are a function of the compositions of proteins as well as geochemical variables including temperature, pressure, oxygen fugacity and pH. The purpose of this study was to explore the dependence of metastable equilibrium states of protein systems on changes in the geochemical variables.     

An intersection‐based trajectory‐region movement study

In order to better understand the movement of an object with respect to a region, we propose a formal model of the evolving spatial relationships that transition between local topologies with respect to a trajectory and a region as well as develop a querying mechanism to analyze movement patterns. We summarize 12 types of local topologies built on trajectory‐region intersections, and derive their transition graph; then we capture and model evolving local topologies with two types of trajectory‐region strings, a movement string and a stop‐move string. The stop‐move string encodes the stop information further during a trajectory than the movement string. Such a string‐format expression of trajectory‐region movement, although conceptually simple, carries unprecedented information for effectively interpreting how trajectories move with respect to regions. We also design the corresponding Finite State Automations for a movement string as well as a stop‐move string, which are used not only to recognize the language of trajectory‐region strings, but also to deal effectively with trajectory‐region pattern queries. When annotated with the time information of stops and intersections, a trajectory‐region movement snapshot and its evolution during a time interval can be inferred, and even the relationships among trajectories with respect to the same region can be explored.     

Matching carbon pools and fluxes for the Southern Ocean Iron Release Experiment (SOIREE)

The Lagrangian Southern Ocean Iron Release Experiment (SOIREE) allowed study of a gradually evolving iron-mediated phytoplankton bloom in water labelled with the inert tracer sulfur hexafluoride, SF₆. This article describes a pelagic carbon budget for the mixed layer in SOIREE and assesses the extent to which closure of the budget is achieved. Net community production (NCP) converted 837 mmol m⁻² of inorganic carbon to organic carbon in 12.0 d after the first iron addition. A large fraction (41%) of NCP remained as particulate organic carbon in the mixed layer of the iron-enriched patch, while 23% was lost by horizontal dispersion and 0–29% was exported. The closure of the carbon budget is hampered by the lack of measurements of dissolved organic carbon (DOC), by a major uncertainty in carbon export, and by use of empirical conversion factors in estimates of carbon biomass and metabolic rates. Lagrangian carbon-budget studies may be improved by direct measurement of all major carbon parameters and conversion factors. Carbon cycling in the SOIREE bloom resembled that in ‘natural’ algal blooms in the open Southern Ocean in some respects, but not in all. Daily NCP in the SOIREE bloom (70 mmol m⁻² d⁻¹) was higher than in natural blooms, partly because other studies did not account for horizontal dispersion, were for longer periods or included less productive areas. The build-up of POC stock and carbon export as a fraction of NCP in SOIREE were in the lower range of observations elsewhere.     

Petrography and geochemistry of basaltic rocks from the Conrad fracture zone on the America-Antarctica Ridge

Intrusive and extrusive basaltic rocks have been dredged from the Conrad fracture zone (transecting the slow-spreading America-Antarctica Ridge). The majority of rocks recovered are holocrystalline with the dominant mineral assemblage being plagioclase plus clinopyroxene with or without minor Fe-Ti oxides (olivine occurs in only three samples) and many of the samples show evidence of extensive alteration. Secondary minerals include chlorite, actinolite, K- and Na-feldspar, analcite and epidote. In terms of bulk chemistry the rocks are characterized by their generally evolved and highly variable compositions (e.g.Mg^*=0.65?0.35;TiO₂=0.7?3.6%;Zr=31?374ppm;Nb=<3?21ppm;Y=17?96ppm;Ni=100?9ppm), but with respect to the immobile incompatible element ratios (e.g. Zr/Nb, Y/Nb, La/Sm) are similar to “normal” or depleted mid-oceanic ridge basalts.Quantitative major and trace element modelling indicate that most of the variation observed can be attributed to low-pressure fractional crystallization of plagioclase plus clinopyroxene in approximately equal proportions with or without minor Fe-Ti oxides. The range in composition can be accounted for by up to 76% fractional crystallization. Although ferrobasalts have not frequently been associated with slow spreading ridges, the extreme differentiation observed in the Conrad fracture zone basalts implies some additional constraint other than spreading rate on the formation of ferrobasalt and reaffirms the importance of extensive crustal differentiation during the production of this basalt type.