Footprint

Distribution by Scientific Domains
Distribution within Life Sciences

Kinds of Footprint

  • ecological footprint
  • environmental footprint
  • small footprint

  • Terms modified by Footprint

  • footprint analysis

  • Selected Abstracts


    CONSTRUCTING, VISUALIZING, AND ANALYZING A DIGITAL FOOTPRINT,

    GEOGRAPHICAL REVIEW, Issue 3 2007
    STEPHEN D. WEAVER
    ABSTRACT. Herein, we discuss the desire for new technology, the need for security, and the right to privacy; in doing so, we argue that each of these concerns comprises an important, tripartite debate. To highlight the complexities in this problem, we define our notion of a "digital footprint" and introduce Big Foot,specialized software created for the research described here to facilitate visualization and exploration of the data that comprise Stephen Weaver's personal digital footprint. Using Big Foot we demonstrate how multiple digital personae can be created from the data that constitute one unique digital footprint and provide a methodology for understanding the good and bad impacts that new technologies may have on future societies. One of the primary arguments of this work is that the debate,though not formally recognized,is currently before contemporary society and must receive sufficient attention. [source]


    Energy Security,Addressing the Water Footprint

    GROUND WATER, Issue 6 2009
    Michael Hightower
    No abstract is available for this article. [source]


    Chad: Re-assessing the Aid Footprint

    AFRICA RESEARCH BULLETIN: ECONOMIC, FINANCIAL AND TECHNICAL SERIES, Issue 12 2010
    Article first published online: 9 FEB 2010
    No abstract is available for this article. [source]


    Images in Cardiac Surgery: Bullet's Path Creates Ballistic Footprint Within Pulmonary Parenchyma

    JOURNAL OF CARDIAC SURGERY, Issue 5 2010
    Ara Ketchedjian M.D.
    No abstract is available for this article. [source]


    Green Footstep: A Tool for Evaluating a Building's Life-Cycle Carbon Footprint and Informing Carbon Decisions During the Building Design Process

    ARCHITECTURAL DESIGN, Issue 3 2010
    Michael Bendewald
    Abstract The Green Footstep model provides a valuable set of metrics for ecodesign and masterplanning. Here Michael Bendewald and Victor Olgyay of the Rocky Mountain Institute (RMI), with Ken Yeang, describe the significance of this new online tool. In addition to supplying the basis for balancing the built environment's engineering systems, the Green Footstep enables efficiency with the use of renewable energy systems, such as photovoltaics (illustrated here). By presenting the critical case for increasing the percentage of new vegetation and trees in new developments, it enhances local biodiversity. Carbon emissions are offset from: on-site clearance of vegetation, the disturbance of the many constituents of the local ecosystem and the removal of organic rich soil by new construction. Copyright © 2010 John Wiley & Sons, Ltd. [source]


    Chlorophyll Catabolites , Chemical and Structural Footprints of a Fascinating Biological Phenomenon,

    EUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 1 2009
    Simone Moser
    Abstract Twenty years ago, the molecular basis for the seasonal disappearance of chlorophyll was still enigmatic. In the meantime, our knowledge on chlorophyll breakdown has grown considerably. As outlined here, it has been possible to decipher the basic transformations involved in natural chlorophyll breakdown by identification of chlorophyll catabolites in higher plants, and with the help of the synthesis of (putative) catabolic intermediates. In vascular plants, chlorophyll breakdown typically converts the green plant pigments efficiently into colorless and non-fluorescent tetrapyrroles. It involves colored intermediates only fleetingly and in an (elusive) enzyme-bound form. The non-fluorescent chlorophyll catabolites accumulate in the vacuoles of degreened leaves and are considered the products, primarily, of a detoxification process. However, they are effective antioxidants, and may thus also have physiologically beneficial chemical properties.(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009) [source]


    Footprints in the Sands of Time: Remembering Herschel Horowitz

    JOURNAL OF PUBLIC HEALTH DENTISTRY, Issue 2004
    James B. Bramson DDS
    No abstract is available for this article. [source]


    The Riddle of Ishtar's Shoes: The Religious Significance of the Footprints at ,Ain Dara from a Comparative Perspective

    JOURNAL OF RELIGIOUS HISTORY, Issue 3 2008
    PAUL BRIAN THOMASArticle first published online: 12 AUG 200
    This essay analyzes the carved footprints in the Iron Age temple at ,Ain Dara, Syria from a broadly comparative perspective. This methodology is necessitated by the fact that footprint iconography is very rare in ancient Near Eastern art. The diverse examples utilized in this paper to help explicate the footprints at ,Ain Dara range from the Footprints of the Buddha (Buddhapadas) to the sullied feet of Jesus. Through analysis of footprint iconography in other religious contexts, I have drawn conclusions concerning the form and function of the temple footprints at ,Ain Dara that have escaped other scholars of the ancient Near East. [source]


    2D Random Organization of Racemic Amino Acid Monolayers Driven by Nanoscale Adsorption Footprints: Proline on Cu(110),

    ANGEWANDTE CHEMIE, Issue 13 2010
    Matthew Forster
    In die Fußstapfen getreten: Racemisches (R,S) - Prolin bildet auf Cu(110) Reihen aus zufällig angeordneten chiralen Aminosäuren, was belegt, dass die Anordnung nicht durch die Molekülchiralität festgelegt wird. Vielmehr wird sie durch ein streng heterochirales Adsorptions-,Fußstapfen"-Templat bestimmt, in dem jede Adsorptionsposition von jedem der Enantiomere besetzt werden kann (siehe Bild), was eine ungeordnete zweidimensionale feste Lösung ergibt. [source]


    Statistical optimization of octree searches

    COMPUTER GRAPHICS FORUM, Issue 6 2008
    Rener Castro
    Abstract This work emerged from the following observation: usual search procedures for octrees start from the root to retrieve the data stored at the leaves. But as the leaves are the farthest nodes to the root, why start from the root? With usual octree representations, there is no other way to access a leaf. However, hashed octrees allow direct access to any node, given its position in space and its depth in the octree. Search procedures take the position as an input, but the depth remains unknown. This work proposes to estimate the depth of an arbitrary node through a statistical optimization of the average cost of search procedures. As the highest costs of these algorithms are obtained when starting from the root, this method improves on both the memory footprint by the use of hashed octrees, and execution time through the proposed optimization. [source]


    Shallow Bounding Volume Hierarchies for Fast SIMD Ray Tracing of Incoherent Rays

    COMPUTER GRAPHICS FORUM, Issue 4 2008
    H. Dammertz
    Abstract Photorealistic image synthesis is a computationally demanding task that relies on ray tracing for the evaluation of integrals. Rendering time is dominated by tracing long paths that are very incoherent by construction. We therefore investigate the use of SIMD instructions to accelerate incoherent rays. SIMD is used in the hierarchy construction, the tree traversal and the leaf intersection. This is achieved by increasing the arity of acceleration structures, which also reduces memory requirements. We show that the resulting hierarchies can be built quickly and are smaller than acceleration structures known so far while at the same time outperforming them for incoherent rays. Our new acceleration structure speeds up ray tracing by a factor of 1.6 to 2.0 compared to a highly optimized bounding interval hierarchy implementation, and 1.3 to 1.6 compared to an efficient kd-tree. At the same time, the memory requirements are reduced by 10,50%. Additionally we show how a caching mechanism in conjunction with this memory efficient hierarchy can be used to speed up shadow rays in a global illumination algorithm without increasing the memory footprint. This optimization decreased the number of traversal steps up to 50%. [source]


    Sustainable entrepreneurship in SMEs: a case study analysis

    CORPORATE SOCIAL RESPONSIBILITY AND ENVIRONMENTAL MANAGEMENT, Issue 3 2010
    Cheryl Rodgers
    Abstract Sustainability is oft thought of as the privilege of the large corporate , with sufficient funds to invest in anything from effective green Public Relations (PR) to improving its carbon footprint. What is perhaps less well-understood and documented is the range of activities undertaken by small and medium enterprises (SMEs), including very small entrepreneurial start-ups, some of which base their entire business rationale on sustainable principles. This paper uses a case study approach to explore the modus operandi of ecopreneurship and draws on both primary research and secondary data to develop and explore sustainable entrepreneurship in this sector. Preliminary findings suggest that ecopreneurial SMEs are looking to other goals alongside financial ones and are prepared to go to significant lengths to achieve such goals. Monetary measures are not, of course, entirely absent, but are very strongly conditioned by the ecoconscious nature of the business. In short, sustainability imperatives remain paramount. Copyright © 2010 John Wiley & Sons, Ltd and ERP Environment. [source]


    Sustainability quotients and the social footprint

    CORPORATE SOCIAL RESPONSIBILITY AND ENVIRONMENTAL MANAGEMENT, Issue 4 2008
    Mark W. McElroy
    Abstract We argue that most of what passes for mainstream reporting in corporate sustainability management fails to do precisely the one thing it purports to do , which is make it possible for organizations to measure and report on the sustainability of their operations. It fails because of the lack of what the Global Reporting Initiative calls sustainability context, a shortcoming from which it, too, suffers. We suggest that this missing context calls for a new notion of sustainability (the binary perspective), which can be conceptualized in the form of sustainability quotients. We provide specifications for such quotients in ecological and social contexts, and suggest that sustainability is best understood in terms of the impact organizations can have on the carrying capacity of non-financial capital, or what in the social case we call anthro capital. We conclude by introducing a quantitative quotients-based method for measuring and reporting on the social sustainability of an organization, the social footprint method. Copyright © 2007 John Wiley & Sons, Ltd and ERP Environment. [source]


    Edible insects: Traditional knowledge or western phobia?

    ENTOMOLOGICAL RESEARCH, Issue 5 2009
    Alan L. YEN
    Abstract With an increasing human population and environmental degradation, the world faces a major problem in providing adequate animal based proteins. Many traditional societies have used or still use insects as a protein source, while westernized societies are reluctant to use insects, despite being the major consumers of animal proteins. We now need to consider insects as a source of food for humans in a manner that acknowledges both the role of entomophagy in indigenous societies and the need for westernized societies to reduce the size of their environmental footprint with regard to food production. The situation on continents such as Africa, Asia, and Central and South America has some parallels to Australia in that there are two forces in operation: the sustainable traditional use of edible insects and the "westernization" of these societies leading to a movement away from entomophagy. However, the potential to reach a compromise is greater in these continents because entomophagy is already accepted. The major challenges will be establishing sustainable production systems that include food safety and security as well as environmental protection. Whether this will happen or not will depend upon: (i) a major change in attitude in westernized societies towards entomophagy; (ii) pressure to conserve remaining habitats in a sustainable manner; (iii) economic impetus to develop food production systems that include insects; and (iv) an acknowledgement that achieving adequate nutrition on a global basis will involve different diets in much of the developed world. [source]


    Molecular mechanisms activating muscle protein degradation in chronic kidney disease and other catabolic conditions

    EUROPEAN JOURNAL OF CLINICAL INVESTIGATION, Issue 3 2005
    J. Du
    Abstract Muscle atrophy is a prominent feature of chronic kidney disease (CKD) and is frequent in other catabolic conditions. Results from animal models of these conditions as well as patients indicate that atrophy is mainly owing to accelerated muscle proteolysis in the ubiquitin-proteasome (Ub-P'some) proteolytic system. The Ub-P'some system, however, rapidly degrades actin or myosin but cannot breakdown actomyosin or myofibrils. Consequently, another protease must initially cleave the complex structure of muscle. We identified caspase-3 as an initial and potentially rate-limiting proteolytic step that cleaves actomyosin/myofibrils to produce substrates degraded by the Ub-P'some system. In rodent models of CKD and other catabolic conditions, we find that caspase-3 is activated and cleaves actomyosin to actin, myosin and their fragments. This initial proteolytic step in muscle leaves a characteristic footprint, a 14-kDa actin band, providing a potential diagnostic tool to detect muscle catabolism. We also found that stimulation of caspase-3 activity depends on inhibition of IRS-1-associated phosphatidylinositol 3-kinase (PI3K) activity; inhibiting PI3K in muscle cells also leads to expression of a critical E3-ubiquitin-conjugating enzyme involved in muscle protein breakdown: atrogin-1/MAFbx. Thus, protein breakdown by caspase-3 and the ubiquitin-proteasome system in muscle are stimulated by the same signal: a low PI3K activity. These responses could yield therapeutic strategies to block muscle atrophy. [source]


    What is reinforcement sensitivity?

    EUROPEAN JOURNAL OF PERSONALITY, Issue 5 2008
    Neuroscience paradigms for approach-avoidance process theories of personality
    Abstract Reinforcement sensitivity is a concept proposed by Gray (1973) to describe the biological antecedents of personality, and has become the common mechanism among a family of personality theories concerning approach and avoidance processes. These theories suggest that 2,3 biobehavioural systems mediate the effects of reward and punishment on emotion and motivation, and that individual differences in the functioning of these systems manifest as personality. Identifying paradigms for operationalising reinforcement sensitivity is therefore critical for testing and developing these theories, and evaluating their footprint in personality space. In this paper I suggest that, while traditional self-report paradigms in personality psychology may be less-than-ideal for this purpose, neuroscience paradigms may offer operations of reinforcement sensitivity at multiple levels of approach and avoidance processes. After brief reflection on the use of such methods in animal models,which first spawned the concept of reinforcement sensitivity,recent developments in four domains of neuroscience are reviewed. These are psychogenomics, psychopharmacology, neuroimaging and category-learning. By exploring these paradigms as potential operations of reinforcement sensitivity we may enrich our understanding of the putative biobehavioural bases of personality. Copyright © 2008 John Wiley & Sons, Ltd. [source]


    Two-stage detection of partitioned random CDMA

    EUROPEAN TRANSACTIONS ON TELECOMMUNICATIONS, Issue 5 2008
    Lukasz Krzymien
    Random Code Division Multiple Access (CDMA) with low complexity two-stage joint detection/decoding is considered. A sequence partitioning approach is used for modulation, where every spreading sequence is divided into M sections (partitions) which are interleaved prior to transmission. This setup, called partitioned CDMA, can be understood as a generalisation of (chip) interleave division multiple access (IDMA). An analysis of a low-complexity iterative cancellation receiver is presented for arbitrary received power distributions. It is shown that for equal rate and equal power users the asymptotic performance of partitioned CDMA is equal to the performance of CDMA with optimal a posteriori probability (APP) detection for system loads K/N,<,1.49. Effects of asynchronous signal transmission are quantified for standard pulse shaping filters and it is shown that the signal-to-noise ratios achievable in an asynchronous system are improved with respect to fully synchronous transmission. The effect of unequal received powers is examined and considerable gains in performance are obtained by judicious choices of power distributions. For certain power distribution, partitioned CDMA with iterative detection can achieve arbitrary system loads, that is detection is no longer fundamentally interference limited. The practical near-far resistance of the proposed system is illustrated using an example of a receiver with a circular receive footprint and uniformly distributed transmitters (single cell system). Copyright © 2008 John Wiley & Sons, Ltd. [source]


    Metabolic profiling as a tool for revealing Saccharomyces interactions during wine fermentation

    FEMS YEAST RESEARCH, Issue 1 2006
    Kate S. Howell
    Abstract The multi-yeast strain composition of wine fermentations has been well established. However, the effect of multiple strains of Saccharomyces spp. on wine flavour is unknown. Here, we demonstrate that multiple strains of Saccharomyces grown together in grape juice can affect the profile of aroma compounds that accumulate during fermentation. A metabolic footprint of each yeast in monoculture, mixed cultures or blended wines was derived by gas chromatography , mass spectrometry measurement of volatiles accumulated during fermentation. The resultant ion spectrograms were transformed and compared by principal-component analysis. The principal-component analysis showed that the profiles of compounds present in wines made by mixed-culture fermentation were different from those where yeasts were grown in monoculture fermentation, and these differences could not be produced by blending wines. Blending of monoculture wines to mimic the population composition of mixed-culture wines showed that yeast metabolic interactions could account for these differences. Additionally, the yeast strain contribution of volatiles to a mixed fermentation cannot be predicted by the population of that yeast. This study provides a novel way to measure the population status of wine fermentations by metabolic footprinting. [source]


    Interpretation of knockout experiments: the congenic footprint

    GENES, BRAIN AND BEHAVIOR, Issue 3 2007
    L. C. Schalkwyk
    In gene targeting experiments, the importance of genetic background is now widely appreciated, and knockout alleles are routinely backcrossed onto a standard inbred background. This produces a congenic strain with a substantial segment of embryonic stem (ES)-cell-derived chromosome still flanking the knockout allele, a phenomenon often neglected in knockout studies. In cholecystokynin 2 (Cckbr) knockout mice backcrossed with C57BL/6, we have found a clear ,congenic footprint' of expression differences in at least 10 genes across 40 Mb sequence flanking the Cckbr locus, each of which is potentially responsible for aspects of the ,knockout' phenotype. The expression differences are overwhelmingly in the knockout-low direction, which may point to a general phenomenon of background dependence. This finding emphasizes the need for caution in using gene knockouts to attribute phenotypic effects to genes. This is especially the case when the gene is of unknown function or the phenotype is unexpected, and is a particular concern for large-scale knockout and phenotypic screening programmes. However, the impact of genetic background should not be simply viewed as a potential confound, but as a unique opportunity to study the broader responses of a system to a specific (genetic) perturbation. [source]


    CONSTRUCTING, VISUALIZING, AND ANALYZING A DIGITAL FOOTPRINT,

    GEOGRAPHICAL REVIEW, Issue 3 2007
    STEPHEN D. WEAVER
    ABSTRACT. Herein, we discuss the desire for new technology, the need for security, and the right to privacy; in doing so, we argue that each of these concerns comprises an important, tripartite debate. To highlight the complexities in this problem, we define our notion of a "digital footprint" and introduce Big Foot,specialized software created for the research described here to facilitate visualization and exploration of the data that comprise Stephen Weaver's personal digital footprint. Using Big Foot we demonstrate how multiple digital personae can be created from the data that constitute one unique digital footprint and provide a methodology for understanding the good and bad impacts that new technologies may have on future societies. One of the primary arguments of this work is that the debate,though not formally recognized,is currently before contemporary society and must receive sufficient attention. [source]


    A strategic approach to advancing sustainability at Steelcase

    GLOBAL BUSINESS AND ORGANIZATIONAL EXCELLENCE, Issue 3 2006
    Allan W. Smith
    To minimize its environmental footprint,in fact, to have a positive impact everywhere it operates,Steelcase pursues many paths to sustainability: environmentally friendly facilities and processes, eco-sensitive products and materials that can be re-used and recycled, informing and engaging stakeholders, and sharing learning with others in the industry, to name just a few. Challenging itself to do more through continuous learning and improvement is at the core of a green strategy that has earned accolades for the company. © 2006 Wiley Periodicals, Inc. [source]


    Stochastic Study of Solute Transport in a Nonstationary Medium

    GROUND WATER, Issue 2 2006
    Bill X. Hu
    A Lagrangian stochastic approach is applied to develop a method of moment for solute transport in a physically and chemically nonstationary medium. Stochastic governing equations for mean solute flux and solute covariance are analytically obtained in the first-order accuracy of log conductivity and/or chemical sorption variances and solved numerically using the finite-difference method. The developed method, the numerical method of moments (NMM), is used to predict radionuclide solute transport processes in the saturated zone below the Yucca Mountain project area. The mean, variance, and upper bound of the radionuclide mass flux through a control plane 5 km downstream of the footprint of the repository are calculated. According to their chemical sorption capacities, the various radionuclear chemicals are grouped as nonreactive, weakly sorbing, and strongly sorbing chemicals. The NMM method is used to study their transport processes and influence factors. To verify the method of moments, a Monte Carlo simulation is conducted for nonreactive chemical transport. Results indicate the results from the two methods are consistent, but the NMM method is computationally more efficient than the Monte Carlo method. This study adds to the ongoing debate in the literature on the effect of heterogeneity on solute transport prediction, especially on prediction uncertainty, by showing that the standard derivation of solute flux is larger than the mean solute flux even when the hydraulic conductivity within each geological layer is mild. This study provides a method that may become an efficient calculation tool for many environmental projects. [source]


    Glacial Sediment Causing Regional-Scale Elevated Arsenic in Drinking Water

    GROUND WATER, Issue 6 2005
    Melinda L. Erickson
    In the upper Midwest, USA, elevated arsenic concentrations in public drinking water systems are associated with the lateral extent of northwest provenance late Wisconsin-aged drift. Twelve percent of public water systems located within the footprint of this drift (212 of 1764) exceed 10 ,g/L arsenic, which is the U.S. EPA's drinking water standard. Outside of the footprint, only 2.4% of public water systems (52 of 2182) exceed 10 ,g/L arsenic. Both glacial drift aquifers and shallow bedrock aquifers overlain by northwest provenance late Wisconsin-aged sediment are affected by arsenic contamination. Evidence suggests that the distinct physical characteristics of northwest provenance late Wisconsin-aged drift,its fine-grained matrix and entrained organic carbon that fosters biological activity,cause the geochemical conditions necessary to mobilize arsenic via reductive mechanisms such as reductive desorption and reductive dissolution of metal oxides. This study highlights an important and often unrecognized phenomenon: high-arsenic sediment is not necessary to cause arsenic-impacted ground water,when "impacted" is now defined as >10 ,g/L. This analysis also demonstrates the scientific and economic value of using existing large but imperfect statewide data sets to observe and characterize regional-scale environmental problems. [source]


    Estimating fog deposition at a Puerto Rican elfin cloud forest site: comparison of the water budget and eddy covariance methods

    HYDROLOGICAL PROCESSES, Issue 13 2006
    F. Holwerda
    Abstract The deposition of fog to a wind-exposed 3 m tall Puerto Rican cloud forest at 1010 m elevation was studied using the water budget and eddy covariance methods. Fog deposition was calculated from the water budget as throughfall plus stemflow plus interception loss minus rainfall corrected for wind-induced loss and effect of slope. The eddy covariance method was used to calculate the turbulent liquid cloud water flux from instantaneous turbulent deviations of the surface-normal wind component and cloud liquid water content as measured at 4 m above the forest canopy. Fog deposition rates according to the water budget under rain-free conditions (0·11 ± 0·05 mm h,1) and rainy conditions (0·24 ± 0·13 mm h,1) were about three to six times the eddy-covariance-based estimate (0·04 ± 0·002 mm h,1). Under rain-free conditions, water-budget-based fog deposition rates were positively correlated with horizontal fluxes of liquid cloud water (as calculated from wind speed and liquid water content data). Under rainy conditions, the correlation became very poor, presumably because of errors in the corrected rainfall amounts and very high spatial variability in throughfall. It was demonstrated that the turbulent liquid cloud water fluxes as measured at 4 m above the forest could be only ,40% of the fluxes at the canopy level itself due to condensation of moisture in air moving upslope. Other factors, which may have contributed to the discrepancy in results obtained with the two methods, were related to effects of footprint mismatch and methodological problems with rainfall measurements under the prevailing windy conditions. Best estimates of annual fog deposition amounted to ,770 mm year,1 for the summit cloud forest just below the ridge top (according to the water budget method) and ,785 mm year,1 for the cloud forest on the lower windward slope (using the eddy-covariance-based deposition rate corrected for estimated vertical flux divergence). Copyright © 2006 John Wiley & Sons, Ltd. [source]


    Validation of ERS scatterometer-derived soil moisture data in the central part of the Duero Basin, Spain

    HYDROLOGICAL PROCESSES, Issue 8 2005
    Antonio Ceballos
    Abstract The objective of this study was to validate the soil moisture data derived from coarse-resolution active microwave data (50 km) from the ERS scatterometer. The retrieval technique is based on a change detection method coupled with a data-based modelling approach to account for seasonal vegetation dynamics. The technique is able to derive information about the soil moisture content corresponding to the degree of saturation of the topmost soil layer (,5 cm). To estimate profile soil moisture contents down to 100 cm depth from the scatterometer data, a simple two-layer water balance model is used, which generates a red noise-like soil moisture spectrum. The retrieval technique had been successfully applied in the Ukraine in a previous study. In this paper, the performance of the model in a semi-arid Mediterranean environment characterized by low annual precipitation (400 mm), hot dry summers and sandy soils is investigated. To this end, field measurements from the REMEDHUS soil moisture station network in the semi-arid parts of the Duero Basin (Spain) were used. The results reveal a significant coefficient of determination (R2 = 0·75) for the averaged 0,100 cm soil moisture profile and a root mean square error (RMSE) of 2·2 vol%. The spatial arrangement of the REMEDHUS soil moisture stations also allowed us to study the influence of the small-scale variability of soil moisture within the ERS scatterometer footprint. The results show that the small-scale variability in the study area is modest and can be explained in terms of texture fraction distribution in the soil profiles. Copyright © 2004 John Wiley & Sons, Ltd. [source]


    Efficient sampling for spatial uncertainty quantification in multibody system dynamics applications

    INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN ENGINEERING, Issue 5 2009
    Kyle P. Schmitt
    Abstract We present two methods for efficiently sampling the response (trajectory space) of multibody systems operating under spatial uncertainty, when the latter is assumed to be representable with Gaussian processes. In this case, the dynamics (time evolution) of the multibody systems depends on spatially indexed uncertain parameters that span infinite-dimensional spaces. This places a heavy computational burden on existing methodologies, an issue addressed herein with two new conditional sampling approaches. When a single instance of the uncertainty is needed in the entire domain, we use a fast Fourier transform technique. When the initial conditions are fixed and the path distribution of the dynamical system is relatively narrow, we use an incremental sampling approach that is fast and has a small memory footprint. Both methods produce the same distributions as the widely used Cholesky-based approaches. We illustrate this convergence at a smaller computational effort and memory cost for a simple non-linear vehicle model. Copyright © 2009 John Wiley & Sons, Ltd. [source]


    Role of the zoo veterinarian in the conservation of captive and free-ranging wildlife

    INTERNATIONAL ZOO YEARBOOK, Issue 1 2007
    S. L. DEEM
    The challenges to execute wildlife conservation projects successfully have become more complex as anthropogenic changes continue to stress the planet, changing wild lands. As the wild becomes less so, more species are placed in captivity to improve their chances of long-term survival, while concurrently management (and medicine) for free-ranging wildlife has become increasingly important. A variety of disciplines, including veterinary medicine, is now recognized as key to wildlife conservation. Although veterinarians have been involved in conservation for decades, it is only recently that their role has become more appreciated in the larger conservation community. This realization of the contributions of veterinarians has occurred at a time when disease has been recognized as significantly impacting species' conservation both in situ and ex situ. Today, veterinarians work with captive and free-ranging animals to prevent and/or treat diseases that threaten species' survival. Most of these diseases are associated with the increasing human footprint. In this paper, I present wildlife health in today's world and the zoo veterinarian's role in wildlife conservation. [source]


    Thresholds in landscape connectivity and mortality risks in response to growing road networks

    JOURNAL OF APPLIED ECOLOGY, Issue 5 2008
    Jacqueline L. Frair
    Summary 1The ecological footprint of a road may extend for several kilometres with overlapping effects from neighbouring roads causing a nonlinear accumulation of road effects in the landscape. Availability of preferred habitat, spatial dependencies between roads and habitat types, and fidelity to traditionally used areas further confound our ability to predict population-level responses of animals to growing road networks. 2To isolate these effects, we developed an individually based movement model using elk Cervus elaphus L. as a model system. Empirically derived movement rules redistributed elk under different amounts of preferred habitat (clearcuts), road densities, and road development schemes. We tracked potential mortality risk (given time spent near roads) and emigration rates (given declining accessibility of foraging habitat). 3Design of the road network accounted for up to 30,55% difference in mortality risk and emigration rates, with the largest differences occurring at intermediate road densities (1,1·5 km km,2) when road effects began to saturate the landscape. Maintaining roads in association with clearcuts caused a decline in habitat accessibility equivalent to replacing 50,75% of these foraging patches with conifer forest. A nine-fold difference in potential emigration was observed after varying elk tolerance for declining habitat accessibility despite holding local movement biases constant. 4Elk responses to growing road networks were non-linear, exposing thresholds for road density that were reflected in the home range occupancy patterns of a large sample of elk in the region. 5Synthesis and applications. Our approach provides a means of scaling-up complex movement decisions to population-level redistribution, separating the confounding effects of landscape context from road effects, and exposing thresholds in connectivity and mortality risks for wildlife caused by infrastructure growth. Our model indicated that road densities , 0·5 km km,2 yielded the highest probability of elk occurrence where elk were hunted (and sensitive to roads), but disassociating roads from foraging habitats or managing human access to roads may maintain effective elk habitat at substantially higher road densities. [source]


    Global patterns of plant diversity and floristic knowledge

    JOURNAL OF BIOGEOGRAPHY, Issue 7 2005
    Gerold Kier
    Abstract Aims, We present the first global map of vascular plant species richness by ecoregion and compare these results with the published literature on global priorities for plant conservation. In so doing, we assess the state of floristic knowledge across ecoregions as described in floras, checklists, and other published documents and pinpoint geographical gaps in our understanding of the global vascular plant flora. Finally, we explore the relationships between plant species richness by ecoregion and our knowledge of the flora, and between plant richness and the human footprint , a spatially explicit measure of the loss and degradation of natural habitats and ecosystems as a result of human activities. Location, Global. Methods, Richness estimates for the 867 terrestrial ecoregions of the world were derived from published richness data of c. 1800 geographical units. We applied one of four methods to assess richness, depending on data quality. These included collation and interpretation of published data, use of species,area curves to extrapolate richness, use of taxon-based data, and estimates derived from other ecoregions within the same biome. Results, The highest estimate of plant species richness is in the Borneo lowlands ecoregion (10,000 species) followed by nine ecoregions located in Central and South America with , 8000 species; all are found within the Tropical and Subtropical Moist Broadleaf Forests biome. Among the 51 ecoregions with , 5000 species, only five are located in temperate regions. For 43% of the 867 ecoregions, data quality was considered good or moderate. Among biomes, adequate data are especially lacking for flooded grasslands and flooded savannas. We found a significant correlation between species richness and data quality for only a few biomes, and, in all of these cases, our results indicated that species-rich ecoregions are better studied than those poor in vascular plants. Similarly, only in a few biomes did we find significant correlations between species richness and the human footprint, all of which were positive. Main conclusions, The work presented here sets the stage for comparisons of degree of concordance of plant species richness with plant endemism and vertebrate species richness: important analyses for a comprehensive global biodiversity strategy. We suggest: (1) that current global plant conservation strategies be reviewed to check if they cover the most outstanding examples of regions from each of the world's major biomes, even if these examples are species-poor compared with other biomes; (2) that flooded grasslands and flooded savannas should become a global priority in collecting and compiling richness data for vascular plants; and (3) that future studies which rely upon species,area calculations do not use a uniform parameter value but instead use values derived separately for subregions. [source]


    Candidate cis -elements for human renin gene expression in the promoter region

    JOURNAL OF CELLULAR BIOCHEMISTRY, Issue 2 2004
    Tadashi Konoshita
    Abstract The regulation of renin gene expression, the rate-limiting enzyme of the system, is thought to be fundamental to the total system. Previously, we mapped six putative cis -elements in the promoter region of the human renin gene with nuclear proteins from human chorionic cells and human renal cortex by DNase I protection assay (footprint A,F). Each footprint contains Ets motif like site (A), HOXñPBX recognition sequence (B), unknown sequence as DNA binding consensus (C), CRE (D), COUP-TFII (ARP-1) motif like site (E), and AGE3 like site (F). Footprint D has been characterized by means of functional studies as the genuine human renin gene CRE interacting with CREB in cooperation with the site of footprint B. To obtain further clues to the specific expression in the promoter region, these putative cis -elements were conducted to a consensus-specific binding assay to compare renin-producing and non-renin-producing cells by EMSA and electromobility super-shift assay. Different sequence-specific DNA/protein binding was obtained among the different cell lines with footprint B site, with COUP-TFII (ARP-1) motif like site and possibly with footprint F site. The results implicate these putative cis -elements and each corresponding trans -factor in the specific expression of the human renin gene in the promoter region. Further functional characterization of these elements would provide important data for a better understanding of human renin gene expression. © 2004 Wiley-Liss, Inc. [source]