Structural Attributes (structural + attribute)

Distribution by Scientific Domains


Selected Abstracts


Predicting Spray Processing Parameters from Required Coating Structural Attributes by Artificial Intelligence,

ADVANCED ENGINEERING MATERIALS, Issue 7 2006
A.-F. Kanta
Predicting processing parameters to manufacture a coating with the required structural attributes is of prime interest to reduce the associate development costs. Such an approach permits, among other advantages, to select the most appropriate scheme among several possible to implement. This paper intends to present such an approach. The specific case of predicting plasma spray process parameters to manufacture a grey alumina (Al2O3 -TiO2, 13% by wt.) coating was considered. [source]


Multiscale structure in sedimentary basins

BASIN RESEARCH, Issue 2 2004
S. A. Stewart
Hierarchies of superimposed structures are found in maps of geological horizons in sedimentary basins. Mapping based on three-dimensional (3D) seismic data includes structures that range in scale from tens of metres to hundreds of kilometres. Extraction of structures from these maps without a priori knowledge of scale and shape is analogous to pattern recognition problems that have been widely researched in disciplines outside of Geoscience. A number of these lessons are integrated and applied within a geological context here. We describe a method for generating multiscale representations from two-dimensional sections and 3D surfaces, and illustrate how superimposed geological structures can be topologically analysed. Multiscale analysis is done in two stages , generation of scale-space as a geometrical attribute, followed by identification of significant scale-space objects. Results indicate that Gaussian filtering is a more robust method than conventional moving average filtering for deriving multiscale geological structure. We introduce the concept of natural scales for identifying the most significant scales in a geological cross section. In three dimensions, scale-dependent structures are identified via an analogous process as discrete topological entities within a four-dimensional scale-space cube. Motivation for this work is to take advantage of the completeness of seismic data coverage to see ,beyond the outcrop' and yield multiscale geological structure. Applications include identifying artefacts, scale-specific features and large-scale structural domains, facilitating multiscale structural attribute mapping for reservoir characterisation, and a novel approach to fold structure classification. [source]


Influences of the vegetation mosaic on riparian and stream environments in a mixed forest-grassland landscape in "Mediterranean" northwestern California

ECOGRAPHY, Issue 4 2005
Hartwell H. Welsh
We examined differences in riparian and aquatic environments within the three dominant vegetation patch types of the Mattole River watershed, a 789-km2 mixed conifer-deciduous (hardwood) forest and grassland-dominated landscape in northwestern California, USA. Riparian and aquatic environments, and particularly microclimates therein, influence the distributions of many vertebrate species, particularly the physiologically-restricted ectotherms , reptiles and amphibians (herpetofauna), and fishes. In addition to being a significant portion of the native biodiversity of a landscape, the presence and relative numbers of these more tractable small vertebrates can serve as useful metrics of its "ecological health." Our primary objective was to determine the range of available riparian and aquatic microclimatic regimes, and discern how these regimes relate to the dominant vegetations that comprise the landscape mosaic. A second objective, reported in a companion paper, was to examine relationships between available microclimatic regimes and herpetofaunal distributions. Here we examined differences in the composition, structure, and related environmental attributes of the three dominant vegetation types, both adjacent to and within the riparian corridors along 49 tributaries. Using automated dataloggers, we recorded hourly water and air temperatures and relative humidity throughout the summer at a representative subset of streams; providing us with daily means and amplitudes for these variables within riparian environments during the hottest period. Although the three vegetation types that dominate this landscape each had unique structural attributes, the overlap in plant species composition indicates that they represent a seral continuum. None-the-less, we found distinct microclimates in each type. Only riparian within late-seral forests contained summer water temperatures that could support cold-water-adapted species. We evaluated landscape-level variables to determine the best predictors of water temperature as represented by the maximum weekly maximum temperature (MWMT). The best model for predicting MWMT (adj. R2=0.69) consisted of catchment area, aspect, and the proportion of non-forested (grassland) patches. Our model provides a useful tool for management of cold-water fauna (e.g. salmonids, stream amphibians) throughout California's "Mediterranean" climate zone. [source]


Why Study Large Projects?

EUROPEAN FINANCIAL MANAGEMENT, Issue 2 2004
An Introduction to Research on Project Finance
G32; G34; L22; G31 Abstract Despite the fact that more than $200 billion of capital investment was financed through project companies in 2001, an amount that grew at a compound annual rate of almost 20% during the 1990s, there has been very little academic research on project finance. The purpose of this article is to explain why project finance in general and why large projects in particular merit separate academic research and instruction. In short, there are significant opportunities to study the relationship among structural attributes (i.e., high leverage, contractual details, and concentrated equity ownership), managerial incentives, and asset values, as well as improve current practice in this rapidly growing field of finance. [source]


Predicting Spray Processing Parameters from Required Coating Structural Attributes by Artificial Intelligence,

ADVANCED ENGINEERING MATERIALS, Issue 7 2006
A.-F. Kanta
Predicting processing parameters to manufacture a coating with the required structural attributes is of prime interest to reduce the associate development costs. Such an approach permits, among other advantages, to select the most appropriate scheme among several possible to implement. This paper intends to present such an approach. The specific case of predicting plasma spray process parameters to manufacture a grey alumina (Al2O3 -TiO2, 13% by wt.) coating was considered. [source]


Regional scale relationships between ecosystem structure and functioning: the case of the Patagonian steppes

GLOBAL ECOLOGY, Issue 5 2004
José M. Paruelo
ABSTRACT Aims, 1. To characterize ecosystem functioning by focusing on above-ground net primary production (ANPP), and 2. to relate the spatial heterogeneity of both functional and structural attributes of vegetation to environmental factors and landscape structure. We discuss the relationship between vegetation structure and functioning found in Patagonia in terms of the capabilities of remote sensing techniques to monitor and assess desertification. Location, Western portion of the Patagonian steppes in Argentina (39°30, S to 45°27, S). Methods, We used remotely-sensed data from Landsat TM and AVHRR/NOAA sensors to characterize vegetation structure (physiognomic units) and ecosystem functioning (ANPP and its seasonal and interannual variation). We combined the satellite information with floristic relevés and field estimates of ANPP. We built an empirical relationship between the Landsat TM-derived normalized difference vegetation index (NDVI) and field ANPP. Using stepwise regressions we explored the relationship between ANPP and both environmental variables (precipitation and temperature surrogates) and structural attributes of the landscape (proportion and diversity of different physiognomic classes (PCs)). Results, PCs were quite heterogeneous in floristic terms, probably reflecting degradation processes. Regional estimates of ANPP showed differences of one order of magnitude among physiognomic classes. Fifty percent of the spatial variance in ANPP was accounted for by longitude, reflecting the dependency of ANPP on precipitation. The proportion of prairies and semideserts, latitude and, to a lesser extent, the number of PCs within an 8 × 8 km cell accounted for an additional 33% of the ANPP variability. ANPP spatial heterogeneity (calculated from Landsat TM data) within an 8 × 8 km cell was positively associated with the mean AVHRR/NOAA NDVI and with the diversity of physiognomic classes. Main conclusions, Our results suggest that the spatial and temporal patterns of ecosystem functioning described from ANPP result not only from water availability and thermal conditions but also from landscape structure (proportion and diversity of different PCs). The structural classification performed using remotely-sensed data captured the spatial variability in physiognomy. Such capability will allow the use of spectral classifications to monitor desertification. [source]


Highly Fluorinated Comb-Shaped Copolymers as Proton Exchange Membranes (PEMs): Improving PEM Properties Through Rational Design,

ADVANCED FUNCTIONAL MATERIALS, Issue 14 2006
B. Norsten
Abstract A new class of comb-shaped polymers for use as a proton conducting membrane is presented. The polymer is designed to combine the beneficial physical, chemical, and structural attributes of fluorinated Nafion-like materials with higher-temperature, polyaromatic-based polymer backbones. The comb-shaped polymer unites a rigid, polyaromatic, hydrophobic backbone with lengthy hydrophilic polymer side chains; this combination affords direct control over the polymer nanostructure within the membrane and results in distinct microphase separation between the opposing domains. The microphase separation serves to compartmentalize water into the hydrophilic polymer side chain domains, resulting in effective membrane water management and excellent proton conductivities. [source]


Co-option of endocytic functions of cellular caveolae by pathogens

IMMUNOLOGY, Issue 1 2001
J.-S. Shin
Summary It is increasingly becoming clear that various immune cells are infected by the very pathogens that they are supposed to attack. Although many mechanisms for microbial entry exist, it appears that a common route of entry shared by certain bacteria, viruses and parasites involves cellular lipid-rich microdomains sometimes called caveolae. These cellular entities, which are characterized by their preferential accumulation of glycosylphosphatidylinositol (GPI)-anchored molecules, cholesterol and various glycolipids, and a distinct protein (caveolin), are present in many effector cells of the immune system including neutrophils, macrophages, mast cells and dendritic cells. These structures have an innate capacity to endocytoze various ligands and traffic them to different intracellular sites and sometimes, back to the extracellular cell surface. Because caveolae do not typically fuse with lysosomes, the ligands borne by caveolar vesicles are essentially intact, which is in marked contrast to ligands endocytozed via the classical endosome,lysosome pathway. A number of microbes or their exotoxins co-opt the unique features of caveolae to enter and traffic, without any apparent loss of viability and function, to different sites within immune and other host cells. In spite of their wide disparity in size and other structural attributes, we predict that a common feature among caveolae-utilizing pathogens and toxins is that their cognate receptor(s) are localized within plasmalemmal caveolae of the host cell. [source]


The role of user charges and structural attributes of quality on the use of maternal health services in Morocco

INTERNATIONAL JOURNAL OF HEALTH PLANNING AND MANAGEMENT, Issue 2 2005
David R. Hotchkiss
Abstract Health care decision makers in settings with low levels of utilization of primary services are faced with the challenge of balancing the sometimes competing goals of increasing coverage and utilization of maternity services, particularly among the poor, with that of ensuring the financial viability of the health system. Morocco is a case in point where this policy dilemma is currently being played out. This study examines the role of household out-of-pocket costs and structural attributes of quality on the use of maternity care in Morocco using empirical data collected from both households and health care facilities. A nested logit model is estimated, and the coefficient estimates are used to carry out policy simulations of the impact of changes in the levels of out-of-pocket fees and structural attributes of quality in order to help guide policy makers responsible for the design of pending social insurance programs. The results of the paper suggest that social insurance strategies that involve increases in out-of-pocket charges in the form of copayments could be implemented without untoward effects on appropriate use of maternity care for non-poor women, but would be contraindicated for poorer and rural households. Copyright © 2005 John Wiley & Sons, Ltd. [source]


DiPAMP's Big Brother "i- Pr-SMS-Phos" Exhibits Exceptional Features Enhancing Rhodium(I)-Catalyzed Hydrogenation of Olefins

ADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 17 2009
Michel Stephan
Abstract Switching Knowles DiPAMP's {DiPAMP=1,2-bis[(o -anisyl)(phenyl)phosphino]- ethane} MeO groups with i- PrO ones led to the i- Pr-SMS-Phos {i- Pr-SMS-Phos=1,2-bis[(o -isoprop- oxyphenyl)(phenyl)phosphino]ethane} ligand which displayed a boosted catalyst activity coupled with an enhanced enantioselectivity in the rhodium(I)-catalyzed hydrogenation of a wide-range of representative olefinic substrates (dehydro-,-amido acids, itaconates, acrylates, enamides, enol acetates, ,,,-diarylethylenes, etc). The rhodium(I)-(i- Pr-SMS-Phos) catalytic profile was investigated revealing its structural attributes and robustness, and in contrast to the usual trend, 31P,NMR analysis revealed that its methyl (Z)-,-acetamidocinnamate (MAC) adduct consisted of a reversed diastereomeric ratio of 1.4:1 in favour of the most reactive diastereomer. [source]


Explaining bird species composition and richness in eucalypt-dominated remnants in subhumid Tasmania

JOURNAL OF BIOGEOGRAPHY, Issue 9 2003
Michael A. MacDonald
Abstract Aim To determine the factors influencing the distribution of birds in remnants in a fragmented agricultural landscape. Location Forty-seven eucalypt remnants and six sites in continuous forest in the subhumid Midlands region of Tasmania, Australia. Methods Sites were censused over a two-year period, and environmental data were collected for remnants. The avifauna of the sites was classified and ordinated. The abundances of bird species, and bird species composition, richness, abundance and diversity were related to environmental variables, using simple correlation and modelling. Results There were two distinct groups of sample sites, which sharply differed in species composition, richness, diversity and bird abundance, separated on the presence/absence of noisy miner (Manorina melanocephala Latham) colonies, remnant size, vegetation structural attributes and variables that reflected disturbance history. The approximate remnant size threshold for the change from one group to another was 20,30 ha. Remnant species richness and diversity were most strongly explained by remnant area and noisy miner abundance, with contributions from structural and isolation attributes in the second case. Segment richness was explained by precipitation, logging history and noisy miner abundance. Bird abundance was positively related to precipitation and negatively related to tree dieback. The 28 individual bird species models were highly individualistic, with vegetation structural variables, noisy miner abundance, climatic variables, variables related to isolation, area, variables related to floristics, disturbance variables, the nature of the matrix and remnant shape all being components in declining order of incidence. Age of the remnant did not relate to any of the dependent variables. Main conclusions Degraded and small remnants may have become more distinct in their avifaunal characteristics than might otherwise be the case, as a result of the establishment of colonies of an aggressive native bird, the noisy miner. The area, isolation and shape of remnants directly relate to the abundance of relatively few species, compared to vegetation attributes, climate and the abundance of the noisy miner. The nature of the matrix is important in the response of some species to fragmentation. [source]


Nonlinear quantitative structure-property relationship modeling of skin permeation coefficient

JOURNAL OF PHARMACEUTICAL SCIENCES, Issue 11 2009
Brian J. Neely
Abstract The permeation coefficient characterizes the ability of a chemical to penetrate the dermis, and the current study describes our efforts to develop structure-based models for the permeation coefficient. Specifically, we have integrated nonlinear, quantitative structure-property relationship (QSPR) models, genetic algorithms (GAs), and neural networks to develop a reliable model. Case studies were conducted to investigate the effects of structural attributes on permeation using a carefully characterized database. Upon careful evaluation, a permeation coefficient data set consisting of 333 data points for 258 molecules was identified, and these data were added to our extensive thermophysical database. Of these data, permeation values for 160 molecular structures were deemed suitable for our modeling efforts. We employed established descriptors and constructed new descriptors to aid the development of a reliable QSPR model for the permeation coefficient. Overall, our new nonlinear QSPR model had an absolute-average percentage deviation, root-mean-square error, and correlation coefficient of 8.0%, 0.34, and 0.93, respectively. Cause-and-effect analysis of the structural descriptors obtained in this study indicates that that three size/shape and two polarity descriptors accounted for ,70% of the permeation information conveyed by the descriptors. © 2009 Wiley-Liss, Inc. and the American Pharmacists Association J Pharm Sci 98:4069,4084, 2009 [source]


Predicting P-glycoprotein substrates by a quantitative structure,activity relationship model

JOURNAL OF PHARMACEUTICAL SCIENCES, Issue 4 2004
Vijay K. Gombar
Abstract A quantitative structure,activity relationship (QSAR) model has been developed to predict whether a given compound is a P-glycoprotein (Pgp) substrate or not. The training set consisted of 95 compounds classified as substrates or non-substrates based on the results from in vitro monolayer efflux assays. The two-group linear discriminant model uses 27 statistically significant, information-rich structure quantifiers to compute the probability of a given structure to be a Pgp substrate. Analysis of the descriptors revealed that the ability to partition into membranes, molecular bulk, and the counts and electrotopological values of certain isolated and bonded hydrides are important structural attributes of substrates. The model fits the data with sensitivity of 100% and specificity of 90.6% in the jackknifed cross-validation test. A prediction accuracy of 86.2% was obtained on a test set of 58 compounds. Examination of the eight "mispredicted" compounds revealed two distinct categories. Five mispredictions were explained by experimental limitations of the efflux assay; these compounds had high permeability and/or were inhibitors of calcein-AM transport. Three mispredictions were due to limitations of the chemical space covered by the current model. The Pgp QSAR model provides an in silico screen to aid in compound selection and in vitro efflux assay prioritization. © 2004 Wiley-Liss, Inc. and the American Pharmacists Association J Pharm Sci 93: 957,968, 2004 [source]


TWO SNOW SPECIES OF THE QUADRIFLAGELLATE GREEN ALGA CHLAINOMONAS (CHLOROPHYTA, VOLVOCALES): ULTRASTRUCTURE AND PHYLOGENETIC POSITION WITHIN THE CHLOROMONAS CLADE,

JOURNAL OF PHYCOLOGY, Issue 4 2008
Philip M. Novis
The quadriflagellate snow alga Chlainomonas Christen, distributed in New Zealand and North America, has several unusual structural attributes. A process assumed to be cytokinesis involves extrusion of protoplasm from the parent through a narrow canal, C. kolii (J. T. Hardy et Curl) Hoham produces a net-like outer envelope rather than a cell wall, and the flagellar basal apparatus of Chlainomonas consists of two semi-independent pairs of basal bodies. Structural connections between basal body pairs appear minimal, but a connecting system different from that observed in other genera exists within each pair. Phylogenetic analysis using rbcL sequences places Chlainomonas in the Chloromonas clade, other known members of which are all biflagellate. Chlainomonas is split into two robust lineages, with New Zealand collections sharing an origin with northern North American collections. Although the quadriflagellate condition is regarded as ancestral in the Chlorophyceae, we speculate,based on ultrastructural and molecular data presented here,that Chlainomonas represents a derived form that has arisen from fusion of two ancestral biflagellate cells. Other explanations (for example, that Chlainomonas represents a diploid form of a biflagellate species) are remotely possible but are presently at odds with extensive observations of field material. Improvements in techniques for experimental manipulation of these sensitive cryophiles will be required to fully characterize their structure and progress our understanding of their biology. [source]


Measurement of lipoxygenase in Australian white wheat flour: the effect of lipoxygenase on the quality properties of white salted noodles

JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 11 2006
Larisa Cato
Abstract The enzyme lipoxygenase has a number of functions in breadmaking. Although white salted noodles are a staple food in various countries, the significance and potential of lipoxygenase in noodlemaking are less well understood. In these products a bright, uniform appearance is particularly important and so the aim of the present research has been to study the effect of endogenous and exogenous lipoxygenase upon discolouration of white salted noodles as well as on the textural and structural attributes. Similar lipoxygenase levels were recorded in the flours studied and no significant losses of activity were found during noodle manufacture and subsequent storage. Less discolouration occurred in treated noodle sheets compared with control samples. Discolouration happened to a lesser extent when samples were cooked immediately after preparation or drying for both treated and control noodles. Whiter noodle sheets were obtained when a soybean lipoxygenase was added to the formulation. Textural and structural properties of white salted noodles were not adversely affected by enzyme addition, giving firm, elastic and non-sticky products. It is concluded that the incorporation of the lipoxygenase preparation offers prospects for colour enhancement of white salted noodles. Copyright © 2006 Society of Chemical Industry [source]


Description of the chemical and pharmacological characteristics of a new hemisynthetic ultra-low-molecular-weight heparin, AVE5026

JOURNAL OF THROMBOSIS AND HAEMOSTASIS, Issue 7 2009
C. VISKOV
Summary.,Background and objectives: AVE5026 is a novel, hemisynthetic, ultra-low-molecular-weight heparin (ULMWH), which is in clinical development for prevention of venous thromboembolism. Its unique structural features result from the highly selective depolymerization of heparin by the phosphazene base that protects the antithrombin (AT)-binding site from destruction. In the present paper, we describe the chemical and biological characteristics of AVE5026, as well as its effects on experimental thrombosis as compared to those of the low-molecular-weight heparin (LMWH) enoxaparin after a single subcutaneous (s.c.) administration in certain animal models. Method and results: AVE5026 has a higher anti-factor Xa (anti-FXa) activity (,160 U mg,1) along with a catalytic anti-thrombin (anti-FIIa) activity (,2 U mg,1) as a result of its structure being strongly enriched in specific AT-binding oligosaccharides. In human plasma, potent inhibition of thrombin generation by AVE5026 was closely related to its anti-FXa activity. In a rat venous thrombosis model, AVE5026 showed a dose-dependent antithrombotic activity comparable to that of enoxaparin (ED50-AVE5026 = 1.6 mg kg,1, ED50-enoxaparin = 2.8 mg kg,1). Interestingly, non-occlusive venous thrombosis in rabbits was inhibited by an ED50 of 0.1 mg kg,1 AVE5026, whereas 0.316 mg kg,1 enoxaparin was not active. In a canine model, similarly to enoxaparin (ED50 = 1.3 mg kg,1), AVE5026 dose-dependently inhibited arterial thrombosis (ED50 = 2.0 mg kg,1). At equipotent doses, AVE5026 did not affect bleeding parameters, whereas enoxaparin showed increased hemorrhage in rats, rabbits and dogs. Conclusion: These unique structural attributes distinguish AVE5026 from the LMWH class. Based on these data in well-established arterial and venous thrombosis models, AVE5026 could represent a valuable alternative in thrombosis prevention with an improved benefit-risk profile as compared to that of enoxaparin. [source]


Relationships between soil hydrology and forest structure and composition in the southern Brazilian Amazon

JOURNAL OF VEGETATION SCIENCE, Issue 2 2007
Stefan Jirka
Abstract Question: Is soil hydrology an important niche-based driver of biodiversity in tropical forests? More specifically, we asked whether seasonal dynamics in soil water regime contributed to vegetation partitioning into distinct forest types. Location: Tropical rain forest in northwestern Mato Grosso, Brazil. Methods: We investigated the distribution of trees and lianas , 1 cm DBH in ten transects that crossed distinct hydrological transitions. Soil water content and depth to water table were measured regularly over a 13-month period. Results: A detrended correspondence analysis (DCA) of 20 dominant species and structural attributes in 10 × 10 m subplots segregated three major forest types: (1) high-statured upland forest with intermediate stem density, (2) medium-statured forest dominated by palms, and (3) low-statured campinarana forest with high stem density. During the rainy season and transition into the dry season, distinct characteristics of the soil water regime (i.e. hydro-indicators) were closely associated with each vegetation community. Stand structural attributes and hydro-indicators were statistically different among forest types. Conclusions: Some upland species appeared intolerant of anaerobic conditions as they were not present in palm and campinarana sites, which experienced prolonged periods of saturation at the soil surface. A shallow impermeable layer restricted rooting depth in the campinarana community, which could heighten drought stress during the dry season. The only vegetation able to persist in campinarana sites were short-statured trees that appear to be well-adapted to the dual extremes of inundation and drought. [source]


A comparative study of multimodal vs. bimodal polyethylene pipe resins for PE-100 applications,

POLYMER ENGINEERING & SCIENCE, Issue 9 2005
Paul J. DesLauriers
In this paper several high density polyethylene pipe resins are compared to polyethylene resins made in the Phillips Loop-Slurry Process (single-reactor), using a catalyst of chromium on modified aluminophosphate (Cr/AlPO4). A brief description of the Cr/AlPO4 system is presented along with polymer chain architecture (i.e., topology) and other structural aspects of polymers made from these catalysts. The physical properties of these resins and their fabricated pipe processing/performance properties were compared to both PE80 and conventional bimodal type PE-100 resins. Results from this study show that high-density polyethylene resins made from Cr/AlPO4 catalysts possess primary structural attributes that are truly unique for chromium-catalyzed resins. These multimodal resins have very high molecular weights (MW; Mw > 400 kg/mol) and exceptionally broad MW distributions (MWD; Mw/Mn > 50). Topologically, these resins were found to have uniform short chain branching distributions across the MWD; as in polymers made from single site metallocene catalysts) and significantly reduced levels (10 times less) of long chain branching when compared to resins made using chromium catalysts on conventional supports. Furthermore, results from rheological, fabricated pipe processing, and performance studies suggest that these resins should be especially well suited for high performance pipe applications. Pipe samples made from these resins were found to meet PE-100 requirements including low temperature impact properties. POLYM. ENG. SCI., 45:1203,1213, 2005. © 2005 Society of Plastics Engineers [source]


The potential of L-band SAR for quantifying mangrove characteristics and change: case studies from the tropics

AQUATIC CONSERVATION: MARINE AND FRESHWATER ECOSYSTEMS, Issue 3 2007
Richard M. Lucas
Abstract 1.The Japan Aerospace Exploration Agency's (JAXA) Advanced Land Observing Satellite (ALOS) L-band Phased Array Synthetic Aperture Radar (PALSAR), launched successfully in January 2006, will provide new data sets for coastal ecosystems mapping and change monitoring at local to global scales. 2.To evaluate L-band capability for mangrove applications, data acquired by the NASA airborne SAR (AIRSAR) and Japanese Earth Resources Satellite (JERS-1 SAR) over sites in Australia, French Guiana and Malaysia were used to demonstrate benefits for mapping extent and zones, retrieving biomass and structural attributes (e.g. height), and detecting change. 3.The research indicates that mapping is most effective where mangroves border non-forested areas and where differences in structure, as a function of species, growth stage and biomass distributions, occur between zones. 4.Using L-band SAR, biomass can be retrieved up to ,100,140 Mg ha,1, although retrieval is complicated by a noticeable decrease in L-band backscattering coefficient within higher (,>200 Mg ha,1) biomass stands, particularly those with extensive prop root systems. 5.Change detection through multi-temporal comparison of data proved useful for mapping deforestation/regeneration and mangrove dynamics associated with changing patterns of sedimentation. 6.The research highlights the likely benefits and limitations of using ALOS PALSAR data and supports JAXA's Kyoto & Carbon (K&C) Initiative in promoting the use of these data for regional mangrove assessment. Copyright © 2007 John Wiley & Sons, Ltd. [source]


Habitat preferences of the noisy miner (Manorina melanocephala) , a propensity for prime real estate?

AUSTRAL ECOLOGY, Issue 3 2009
JOANNE M. OLDLAND
Abstract This study investigated habitat characteristics that have been postulated to influence the occurrence of noisy miners (Manorina melanocephala Family Meliphagidae). It builds on an earlier study that identified corners along remnant edges as important predictors of the presence of noisy miners in large blocks of remnant vegetation (>300 ha). Six habitat characteristics were recorded at 39 corner sites within the box-ironbark region of Victoria. We failed to detect any significant effect of the density of understorey vegetation on the likelihood of noisy miners occupying a site, but this might have been an artefact of prolonged drought conditions. The most powerful predictors of the presence of noisy miners at remnant corners were found to be soil type and the proportion of canopy trees at a site that were yellow gum (Eucalyptus leucoxylon), with noisy miners being associated with deeper, more fertile soils and higher proportions of yellow gums present. As yellow gum is a prolific and reliable nectar producer, the inherent productivity of a site might be more important in determining the attractiveness of a site to noisy miners than structural attributes like the presence or absence of an understorey. Noisy miners are sedentary colonial birds that occupy year-round territories, often at high densities. Sites capable of supporting such high density occupation year-round might be limited to the most productive sites within the landscape. This productivity hypothesis has potentially profound implications for other woodland avifauna, as noisy miners might be excluding other woodland birds from some of the most fertile components of the landscape; components that are already rare in the box-ironbark region due preferential clearing for agriculture at the time of settlement. [source]