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Interesting Patterns (interesting + pattern)
Selected AbstractsRole of ethylenediaminetetraacetic acid on lead uptake and translocation by tumbleweed (Salsola kali L.)ENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 5 2007Guadalupe de la Rosa Abstract Tumbleweed plants (Salsola kali L.) grown in agar and liquid media demonstrated a high capacity to accumulate Pb in their different parts without affecting biomass. Whereas shoot elongation and biomass were not significantly affected by high tissue concentrations of Pb, root growth was significantly affected relative to controls. Roots, stems, and leaves demonstrated Pb concentrations of 31,000, 5,500, and 2,100 mg/kg dry weight, respectively, when plants were grown in the agar medium containing 80 mg Pb/L. Application of ethylenediaminetetraacetic acid (EDTA) to Pb-contaminated media dramatically reduced the total acquisition of Pb from both types of media. However, EDTA significantly increased the translocation of Pb from roots to the aerial parts, as evidenced by a multifold increase (23- and 155-fold for agar and liquid media, respectively) in the translocation concentration factor. The concentration of the antioxidant thiol compounds significantly increased (p < 0.05) in plants grown with uncomplexed Pb treatments relative to control plants. Scanning-electron microscopy and electron dispersive x-ray spectroscopic evaluation of leaf samples demonstrated an interesting pattern of Pb translocation in the presence or absence of EDTA. Large Pb crystals were found across the leaf tissues (palisade, spongy parenchyma, and conducting tissues) in the absence of EDTA. Lead nanoparticles also were seen when plants were grown in Pb-EDTA solution. Ultramicroscopic features of tumbleweed provide clear evidence for the unrestricted conduction of Pb from the root to the aerial parts, and this property makes the plant a good candidate for phytoremediation. [source] Diversity patterns amongst herbivorous dinosaurs and plants during the Cretaceous: implications for hypotheses of dinosaur/angiosperm co-evolutionJOURNAL OF EVOLUTIONARY BIOLOGY, Issue 3 2009R. J. BUTLER Abstract Palaeobiologists frequently attempt to identify examples of co-evolutionary interactions over extended geological timescales. These hypotheses are often intuitively appealing, as co-evolution is so prevalent in extant ecosystems, and are easy to formulate; however, they are much more difficult to test than their modern analogues. Among the more intriguing deep time co-evolutionary scenarios are those that relate changes in Cretaceous dinosaur faunas to the primary radiation of flowering plants. Demonstration of temporal congruence between the diversifications of co-evolving groups is necessary to establish whether co-evolution could have occurred in such cases, but is insufficient to prove whether it actually did take place. Diversity patterns do, however, provide a means for falsifying such hypotheses. We have compiled a new database of Cretaceous dinosaur and plant distributions from information in the primary literature. This is used as the basis for plotting taxonomic diversity and occurrence curves for herbivorous dinosaurs (Sauropodomorpha, Stegosauria, Ankylosauria, Ornithopoda, Ceratopsia, Pachycephalosauria and herbivorous theropods) and major groups of plants (angiosperms, Bennettitales, cycads, cycadophytes, conifers, Filicales and Ginkgoales) that co-occur in dinosaur-bearing formations. Pairwise statistical comparisons were made between various floral and faunal groups to test for any significant similarities in the shapes of their diversity curves through time. We show that, with one possible exception, diversity patterns for major groups of herbivorous dinosaurs are not positively correlated with angiosperm diversity. In other words, at the level of major clades, there is no support for any diffuse co-evolutionary relationship between herbivorous dinosaurs and flowering plants. The diversification of Late Cretaceous pachycephalosaurs (excluding the problematic taxon Stenopelix) shows a positive correlation, but this might be spuriously related to poor sampling in the Turonian,Santonian interval. Stegosauria shows a significant negative correlation with flowering plants and a significant positive correlation with the nonflowering cycadophytes (cycads, Bennettitales). This interesting pattern is worthy of further investigation, and it reflects the decline of both stegosaurs and cycadophytes during the Early Cretaceous. [source] Cardiovascular magnetic resonance reveals similar damage to the heart of patients with becker and limb-girdle muscular dystrophy but no cardiac symptomsJOURNAL OF MAGNETIC RESONANCE IMAGING, Issue 4 2009Ali Yilmaz MD Abstract Cardiac involvement in patients with a sarcoglycanopathy (limb-girdle muscular dystrophy) has been described previously; however, this is the first cardiovascular magnetic resonance (CMR) study in such a patient demonstrating an interesting pattern of myocardial damage using late gadolinium enhancement (LGE) imaging. Moreover, the wall motion abnormality and the subepicardial pattern of LGE in this patient with a sarcoglycanopathy is in agreement with the findings in another patient with Becker muscular dystrophy. The predominance of LGE in the subepicardial layers of the left ventricular inferolateral wall suggests that such a myocardial damage pattern represents a nonspecific cardiac phenotype in response to exaggerated mechanical stress in this region, at least in patients with a sarcoglycanopathy or dystrophinopathy. J. Magn. Reson. Imaging 2009;30:876,877. © 2009 Wiley-Liss, Inc. [source] Supporting user-subjective categorization with self-organizing maps and learning vector quantizationJOURNAL OF THE AMERICAN SOCIETY FOR INFORMATION SCIENCE AND TECHNOLOGY, Issue 4 2005Dina Goren-Bar Today, most document categorization in organizations is done manually. We save at work hundreds of files and e-mail messages in folders every day. While automatic document categorization has been widely studied, much challenging research still remains to support user-subjective categorization. This study evaluates and compares the application of self-organizing maps (SOMs) and learning vector quantization (LVQ) with automatic document classification, using a set of documents from an organization, in a specific domain, manually classified by a domain expert. After running the SOM and LVQ we requested the user to reclassify documents that were misclassified by the system. Results show that despite the subjective nature of human categorization, automatic document categorization methods correlate well with subjective, personal categorization, and the LVQ method outperforms the SOM. The reclassification process revealed an interesting pattern: About 40% of the documents were classified according to their original categorization, about 35% according to the system's categorization (the users changed the original categorization), and the remainder received a different (new) categorization. Based on these results we conclude that automatic support for subjective categorization is feasible; however, an exact match is probably impossible due to the users' changing categorization behavior. [source] Towards closing the analysis gap: Visual generation of decision supporting schemes from raw dataCOMPUTER GRAPHICS FORUM, Issue 3 2008T. May Abstract The derivation, manipulation and verification of analytical models from raw data is a process which requires a transformation of information across different levels of abstraction. We introduce a concept for the coupling of data classification and interactive visualization in order to make this transformation visible and steerable for the human user. Data classification techniques generate mappings that formally group data items into categories. Interactive visualization includes the user into an iterative refinement process. The user identifies and selects interesting patterns to define these categories. The following step is the transformation of a visible pattern into the formal definition of a classifier. In the last step the classifier is transformed back into a pattern that is blended with the original data in the same visual display. Our approach allows in intuitive assessment of a formal classifier and its model, the detection of outliers and the handling of noisy data using visual pattern-matching. We instantiated the concept using decision trees for classification and KVMaps as the visualization technique. The generation of a classifier from visual patterns and its verification is transformed from a cognitive to a mostly pre-cognitive task. [source] Spatial and temporal variability in seed dynamics of machair sand dune plant communities, the Outer Hebrides, ScotlandJOURNAL OF BIOGEOGRAPHY, Issue 5 2001N. W. Owen Aim The subjects of seed banks and seed rain represent comparatively neglected areas of biogeography, yet at the community scale, exhibit interesting patterns in both space and time. This paper describes the seed bank and seed rain characteristics of the machair sand dune communities of the Outer Hebrides. As well as looking at individual species distributions and variability, the seed banks and seed rain are examined in terms of their detailed subcommunity composition and its local spatial and temporal variation. The machair plant (sub)communities show extensive degrees of anthropogenic modification because of past and present agricultural management, including cultivation for cereals over wide areas and for potatoes in large numbers of ,lazy beds' or small patches. Thus over the historical period, large areas of machair have undergone regular ploughing and cultivation, which have provided the opportunity for a patchwork of secondary succession to occur. This pattern continues to the present day. Furthermore, most other non-cultivated plant (sub)communities are intensively grazed, primarily by cattle and also by sheep and rabbits. Location South Uist, the Outer Hebrides, north-west Scotland. Methods At two carefully selected locations, a range of these various successional subcommunities have been sampled for their seed banks, by taking cores and for their seed rain, by using specially designed traps located where each seed bank sample was removed. This paired sampling strategy allowed direct comparison of the seed bank and the seed rain. Both individual species distributions and the community assemblages of seed bank/seed rain species are examined in space and time using techniques of numerical classification [two-way indicator species analysis (TWINSPAN)] and ordination [detrended correspondence analysis (DCA)]. Results and conclusions There is considerable heterogeneity within and between machair subcommunities in terms of seed bank and seed rain characteristics. The soil seed banks and seed rain of the agriculturally disturbed machair subcommunities are consistently more dense and more species rich than non-cultivated areas of the machair. Overall, machair seed banks are small and stable with no discernible seasonal trends in either size or species composition. In contrast, seed rain on the machair is characterized by a distinct temporal trend. Both seed banks and seed rain are potentially very poor sources of propagules for recolonization following disturbance, indicating that the majority of revegetation following anthropogenic and/or environmental interference is through vegetative reproduction. [source] Technological Change and Transition: Relative Contributions to Worldwide Growth During the 1990s,OXFORD BULLETIN OF ECONOMICS & STATISTICS, Issue 4 2008Oleg Badunenko Abstract In this paper we use the Kumar and Russell [American Economic Review (2002) Vol. 92, pp. 527,548] growth-accounting procedure to examine cross-country growth during the 1990s. Using a data set comprising developed, newly industrialized, developing and transitional economies, we decompose the growth of output per worker into components attributable to technological catch-up, technological change and capital accumulation. In contrast to the study by Kumar and Russell, which concludes that capital deepening is the major force of growth and change in the world income per worker distribution over the 1965,90 period, our analysis shows that, during the 1990s, the major force in the further divergence of the rich and the poor is due to technological change, whereas capital accumulation plays a lesser and opposite role. Finally, although on average we find that transitional economies perform similar to the rest of the world, the procedure is able to discover some interesting patterns within the set of transitional countries. [source] Variations in the Thickness and Composition of the Skin of the GiraffeTHE ANATOMICAL RECORD : ADVANCES IN INTEGRATIVE ANATOMY AND EVOLUTIONARY BIOLOGY, Issue 9 2010Farzana Sathar Abstract This study examined the skin of two 1- to 2-year-old male giraffes and one adult male, determining skin thickness and histological structure with reference to it functioning as a component of the features required for the maintenance of blood pressure, dermal armor, or thermoregulation. It has been argued that a tight skin surrounding the extremities of the giraffe aids in the movement of fluid against gravity, hence preventing pooling of blood and tissue fluid (edema), but the skin has also been implicated in the thermoregulatory capacities and defensive anatomy of many mammalian species. In one of the younger giraffes, one-half of the skin was analyzed from which close to 170 sites were measured. In the other young and adult giraffes, spot tests to confirm the pattern observed in the fully analyzed individual were undertaken. It was discovered that the skin varied in thickness across the entire body and within regions of the body. Histological evaluation revealed that the skin was mostly collagenous, although interesting patterns of elastic fiber densities were also apparent. The skin in the neck and legs exhibited a morphology that may assist in cardiovascular regulation of blood flow to and from the head and legs, and the skin of the trunk and anterior neck has the possibility of functioning in a protective role. The analyses performed could not add any new data regarding the thermoregulatory role already described for giraffe skin. Anat Rec 293:1615,1627, 2010. © 2010 Wiley-Liss, Inc. [source] "Specialized" Production in Archaeological Contexts: Rethinking Specialization, the Social Value of Products, and the Practice of ProductionARCHEOLOGICAL PAPERS OF THE AMERICAN ANTHROPOLOGICAL ASSOCIATION, Issue 1 2007Rowan K. Flad The contributions to this volume are introduced via a critical review of terms and concepts used in craft production studies today. Recent detailed contextual and technological analyses of artifacts from all aspects of complex societies have revealed interesting patterns that are difficult to conceptualize using a purely economic framework. Furthermore, interest in practice theory, and sociocultural theory in general, has shifted some foci of archaeological investigation toward the social aspects of production and specialization. New data, methods, and theories require a rethinking of what is meant by specialized production, and this chapter represents an introduction to this endeavor. [source] Feasibility study of multicentre comparison of NHS hospital pharmacy computer dataBRITISH JOURNAL OF CLINICAL PHARMACOLOGY, Issue 1 2000Pauline Debra Walker Aims This study aims to determine the feasibility of collecting, collating and analysing drug expenditure data from a sample of acute hospitals in England. Methods The hospital pharmacy computer system was used to report on drug expenditure from 16 hospitals throughout England for a 2 year period. These data were analysed as a whole and hospital episode statistics were correlated to hospital drug costs. Results Hospital outpatient costs were found to be approximately one third of hospital inpatient costs. Cardiovascular drugs accounted for the greatest increase in expenditure for both inpatients and outpatients (25%). The most expensive therapeutic area of drug use across all sites was anti-infectives. The average daily number of occupied beds explained 55% of the variation in inpatient expenditure and the number of outpatient (including Accident and Emergency) attendances explained 60% of the outpatient drug expenditure. Conclusions This project has confirmed the feasibility of collecting, collating and analysing hospital drug expenditure and identified some interesting patterns and trends in hospital drug use. Hospital activity is reflected in hospital drug costs. [source] | |||||||||||||||||||