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Sample records for addition similar patterns

  1. Additive Similarity Trees

    ERIC Educational Resources Information Center

    Sattath, Shmuel; Tversky, Amos

    1977-01-01

    Tree representations of similarity data are investigated. Hierarchical clustering is critically examined, and a more general procedure, called the additive tree, is presented. The additive tree representation is then compared to multidimensional scaling. (Author/JKS)

  2. Effect of similarity between patterns in associative memory

    NASA Astrophysics Data System (ADS)

    Wang, Sheng-Jun; Yang, Zhou

    2017-01-01

    We study the stability of patterns in Hopfield networks in which a part of memorized patterns are similar. The similarity between patterns impacts the stability of these patterns, but the stability of other independent patterns is only changed slightly. We show that the stability of patterns is affected in different ways by similarity. For networks storing a number of patterns, the similarity between patterns enhances the pattern stability. However, the stability of patterns can be weakened by the similarity when networks store fewer patterns, and the relation between the stability of patterns and similarity is nonmonotonic. We present a theoretical explanation of the effect of similarity on stability using signal-to-noise-ratio analysis.

  3. Similarity measures for pattern matching on-the-fly

    NASA Astrophysics Data System (ADS)

    Caluori, Ursina; Simon, Klaus

    2013-12-01

    Recently, we presented a new OCR-concept [1] for historic prints. The core part is the glyph recognition based on pattern matching with patterns that are derived from computer font glyphs and are generated on-the-fly. The classification of a sample is organized as a search process for the most similar glyph pattern. In this paper, we investigate several similarity measures which are of vital importance for this concept.

  4. Self-similar Turing patterns: An anomalous diffusion consequence

    NASA Astrophysics Data System (ADS)

    Hernández, D.; Herrera-Hernández, E. C.; Núñez-López, M.; Hernández-Coronado, H.

    2017-02-01

    In this work, we show that under specific anomalous diffusion conditions, chemical systems can produce well-ordered self-similar concentration patterns through diffusion-driven instability. We also find spiral patterns and patterns with mixtures of rotational symmetries. The type of anomalous diffusion discussed in this work, either subdiffusion or superdiffusion, is a consequence of the medium heterogeneity, and it is modeled through a space-dependent diffusion coefficient with a power-law functional form.

  5. Self-similar Turing patterns: An anomalous diffusion consequence.

    PubMed

    Hernández, D; Herrera-Hernández, E C; Núñez-López, M; Hernández-Coronado, H

    2017-02-01

    In this work, we show that under specific anomalous diffusion conditions, chemical systems can produce well-ordered self-similar concentration patterns through diffusion-driven instability. We also find spiral patterns and patterns with mixtures of rotational symmetries. The type of anomalous diffusion discussed in this work, either subdiffusion or superdiffusion, is a consequence of the medium heterogeneity, and it is modeled through a space-dependent diffusion coefficient with a power-law functional form.

  6. Database of patterns PROF_PAT for detecting local similarities.

    PubMed

    Nizolenko, Lily P; Bachinsky, Alexander G; Naumochkin, Andrey N; Yarigin, Andrey A; Grigorovich, Dmitry A

    2003-01-01

    We have developed PROF_PAT, a database of patterns, constructed for groups of related proteins and designed to maximize representation of amino acid sequences from the SWISS-PROT database. The purpose of the current study was to demonstrate that PROT_PAT is not only as good as known analogs but surpasses them in some features. 10938 new amino acid sequences from the SWISS-PROT bank were compared with patterns constructed for protein families in the PROF_PAT 1.10 bank. The aim of the comparisons was to estimate some threshold values of "Score" parameter to distinguish random similarities from significant ones. From the 10938 new sequences, 638 did not reveal any similarities with PROF_PAT patterns. Cases of found similarities were divided into three sets: 'positive', 'putative' (or 'unknown'), and 'false positive', containing 7719, 2297 and 284 sequences respectively. Using 20 amino acid sequences from the TrEMBL bank that have no descriptions, PROF_PAT demonstrated specificity at a level that was as good as the best-known "secondary" banks. At the same time, its pattern content and variety of included proteins was significantly richer, and its search speed was 3-10 times higher than those of any other protein family bank used for comparison.

  7. Similar Fracture Patterns in Human Nose and Gothic Cathedral.

    PubMed

    Lee, Shu Jin; Tse, Kwong Ming; Lee, Heow Pueh

    2015-10-01

    This study proposes that the bony anatomy of the human nose and masonry structure of the Gothic cathedral are geometrically similar, and have common fracture patterns. We also aim to correlate the fracture patterns observed in patients' midface structures with those seen in the Gothic cathedral using computational approach. CT scans of 33 patients with facial fractures were examined and compared with computer simulations of both the Gothic cathedral and human nose. Three similar patterns were found: (1) Cracks of the nasal arch with crumpling of the vertical buttresses akin to the damage seen during minor earthquakes; (2) lateral deviation of the central nasal arch and collapse of the vertical buttresses akin to those due to lateral forces from wind and in major earthquakes; and (3) Central arch collapse seen as a result of collapse under excessive dead weight. Interestingly, the finding of occult nasal and septal fractures in the mandible fractures with absence of direct nasal trauma highlights the possibility of transmission of forces from the foundation to the arch leading to structural failure. It was also found that the structural buttresses of the Gothic cathedral delineate the vertical buttresses in the human midface structure. These morphologic similarities between the human nose and Gothic cathedral will serve as a basis to study the biomechanics of nasal fractures. Identification of structural buttresses in a skeletal structure has important implications for reconstruction as reestablishment of structural continuity restores normal anatomy and architectural stability of the human midface structure.

  8. Disambiguating the similar: the dentate gyrus and pattern separation.

    PubMed

    Schmidt, Brandy; Marrone, Diano F; Markus, Etan J

    2012-01-01

    The human hippocampus supports the formation of episodic memory without confusing new memories with old ones. To accomplish this, the brain must disambiguate memories (i.e., accentuate the differences between experiences). There is convergent evidence linking pattern separation to the dentate gyrus. Damage to the dentate gyrus reduces an organism's ability to differentiate between similar objects. The dentate gyrus has tenfold more principle cells than its cortical input, allowing for a divergence in information flow. Dentate gyrus granule neurons also show a very different pattern of representing the environment than "classic" place cells in CA1 and CA3, or grid cells in the entorhinal cortex. More recently immediate early genes have been used to "timestamp" activity of individual cells throughout the dentate gyrus. These data indicate that the dentate gyrus robustly differentiates similar situations. The degree of differentiation is non-linear, with even small changes in input inducing a near maximal response in the dentate. Furthermore this differentiation occurs throughout the dentate gyrus longitudinal (dorsal-ventral) axis. Conversely, the data point to a divergence in information processing between the dentate gyrus suprapyramidal and infrapyramidal blades possibly related to differences in organization within these regions. The accumulated evidence from different approaches converges to support a role for the dentate gyrus in pattern separation. There are however inconsistencies that may require incorporation of neurogenesis and hippocampal microcircuits into the currents models. They also suggest different roles for the dentate gyrus suprapyramidal and infrapyramidal blades, and the responsiveness of CA3 to dentate input.

  9. Diversification patterns in cosmopolitan earthworms: similar mode but different tempo.

    PubMed

    Fernández, Rosa; Novo, Marta; Marchán, Daniel F; Díaz Cosín, Darío J

    2016-01-01

    Comparative phylogeography of widespread species that span the same geographic areas can elucidate the influence of historical events on current patterns of biodiversity, identify patterns of co-vicariance, and therefore aid the understanding of general evolutionary processes. Soil-dwelling animals present characteristics that make them suitable for testing the effect of the palaeogeographical events on their distribution and diversification, such as their low vagility and population structure. In this study, we shed light on the spatial lineage diversification and cladogenesis of two widely-distributed cosmopolitan and invasive earthworms (Aporrectodea rosea and A. trapezoides) in their putative ancestral area of origin, the Western Palearctic, and a few populations in North America. Molecular analyses were conducted on mitochondrial and nuclear markers from 220 (A. rosea) and 198 (A. trapezoides) individuals collected in 56 and 57 localities, respectively. We compared the lineage diversification pattern, genetic variability and cladogenesis in both species. Our findings showed that both species underwent a similar diversification from the Western Mediterranean plates to (i) Northern Europe and (ii) the Iberian Peninsula, establishing their two main lineages. Their diversification was in concordance with the main palaeogeographical events in the Iberian Peninsula and Western Mediterranean, followed by a later colonization of North America from individuals derived exclusively from the Eurosiberian lineage. Their diversification occurred at different times, with the diversification of A. rosea being potentially more ancient. Cladogenesis in both species seems to have been modelled only by the Mediterranean plate shifts, ignoring historical climatic oscillations such as the Messinian salinity crisis. Their high genetic variability, strong population structure, lack of gene flow and stepping-stone-like cladogenesis suggest the existence of different cryptic lineages

  10. Super Memory Bros.: going from mirror patterns to concordant patterns via similarity enhancements.

    PubMed

    Ozubko, Jason D; Joordens, Steve

    2008-12-01

    When memory is contrasted for stimuli belonging to distinct stimulus classes, one of two patterns is observed: a mirror pattern, in which one stimulus gives rise to higher hits but lower false alarms (e.g., the frequency-based mirror effect) or a concordant pattern, in which one stimulus class gives rise both to higher hits and to higher false alarms (e.g., the pseudoword effect). On the basis of the dual-process account proposed by Joordens and Hockley (2000), we predict that mirror patterns occur when one stimulus class is more familiar and less distinctive than another, whereas concordant patterns occur when one stimulus class is more familiar than another. We tested these assumptions within a video game paradigm using novel stimuli that allow manipulations in terms of distinctiveness and familiarity (via similarity). When more distinctive, less familiar items are contrasted with less distinctive, more familiar items, a mirror pattern is observed. Systematically enhancing the familiarity of stimuli transforms the mirror pattern to a concordant pattern as predicted. Although our stimuli differ considerably from those used in examinations of the frequency-based mirror effect and the pseudoword effect, the implications of our findings with respect to those phenomena are also discussed.

  11. Investigation of Time Series Representations and Similarity Measures for Structural Damage Pattern Recognition

    PubMed Central

    Swartz, R. Andrew

    2013-01-01

    This paper investigates the time series representation methods and similarity measures for sensor data feature extraction and structural damage pattern recognition. Both model-based time series representation and dimensionality reduction methods are studied to compare the effectiveness of feature extraction for damage pattern recognition. The evaluation of feature extraction methods is performed by examining the separation of feature vectors among different damage patterns and the pattern recognition success rate. In addition, the impact of similarity measures on the pattern recognition success rate and the metrics for damage localization are also investigated. The test data used in this study are from the System Identification to Monitor Civil Engineering Structures (SIMCES) Z24 Bridge damage detection tests, a rigorous instrumentation campaign that recorded the dynamic performance of a concrete box-girder bridge under progressively increasing damage scenarios. A number of progressive damage test case datasets and damage test data with different damage modalities are used. The simulation results show that both time series representation methods and similarity measures have significant impact on the pattern recognition success rate. PMID:24191136

  12. Similarity

    NASA Technical Reports Server (NTRS)

    Apostol, Tom M. (Editor)

    1990-01-01

    In this 'Project Mathematics! series, sponsored by the California Institute for Technology (CalTech), the mathematical concept of similarity is presented. he history of and real life applications are discussed using actual film footage and computer animation. Terms used and various concepts of size, shape, ratio, area, and volume are demonstrated. The similarity of polygons, solids, congruent triangles, internal ratios, perimeters, and line segments using the previous mentioned concepts are shown.

  13. Complementary Role of Frontoparietal Activity and Cortical Pattern Similarity in Successful Episodic Memory Encoding

    PubMed Central

    Xue, Gui; Dong, Qi; Chen, Chuansheng; Lu, Zhong-Lin; Mumford, Jeanette A.; Poldrack, Russell A.

    2013-01-01

    One central goal in cognitive neuroscience of learning and memory is to characterize the neural processes that lead to long-lasting episodic memory. In addition to the stronger frontoparietal activity, greater category- or item-specific cortical representation during encoding, as measured by pattern similarity (PS), is also associated with better subsequent episodic memory. Nevertheless, it is unknown whether frontoparietal activity and cortical PS reflect distinct mechanisms. To address this issue, we reanalyzed previous data (Xue G, Dong Q, Chen C, Lu ZL, Mumford JA, Poldrack RA. 2010. Greater neural pattern similarity across repetitions is associated with better memory. Science. 330:97, Experiment 3) using a novel approach based on combined activation-based and information-based analyses. The results showed that across items, stronger frontoparietal activity was associated with greater PS in distributed brain regions, including those where the PS was predictive of better subsequent memory. Nevertheless, the item-specific PS was still associated with later episodic memory after controlling the effect of frontoparietal activity. Our results suggest that one possible mechanism of frontoparietal activity on episodic memory encoding is via enhancing PS, resulting in more unique and consistent input to the medial temporal lobe. In addition, they suggest that PS might index additional processes, such as pattern reinstatement as a result of study-phase retrieval, that contribute to episodic memory encoding. PMID:22645250

  14. Similarity breeds proximity: Pattern similarity within and across contexts is related to later mnemonic judgments of temporal proximity

    PubMed Central

    Ezzyat, Youssef; Davachi, Lila

    2014-01-01

    Summary Experiences unfold over time, but little is known about the mechanisms that support the formation of coherent episodic memories for temporally-extended events. Recent work in animals has provided evidence for signals in hippocampus that could link events across temporal gaps, however it is unknown whether and how such signals might be related to later memory for temporal information in humans. We measured patterns of fMRI BOLD activity as people encoded items that were separated in time and manipulated the presence of shared or distinct context across items. We found that hippocampal pattern similarity in the BOLD response across trials predicted later temporal memory decisions when context changed. By contrast, pattern similarity in lateral occipital cortex was related to memory only when context remained stable. These data provide the first evidence in humans that representational stability in hippocampus across time may be a mechanism for temporal memory organization. PMID:24607235

  15. Genetic Algorithm-Based Relevance Feedback for Image Retrieval Using Local Similarity Patterns.

    ERIC Educational Resources Information Center

    Stejic, Zoran; Takama, Yasufumi; Hirota, Kaoru

    2003-01-01

    Proposes local similarity pattern (LSP) as a new method for computing digital image similarity. Topics include optimizing similarity computation based on genetic algorithm; relevance feedback; and an evaluation of LSP on five databases that showed an increase in retrieval precision over other methods for computing image similarity. (Author/LRW)

  16. A Review of a Rotation to Obtain Maximum Similarity and Simple Structure Among Factor Patterns.

    ERIC Educational Resources Information Center

    Jensema, Carl

    Under some circumstances, it is desirable to compare the factor patterns obtained from different factor analyses. To date, the best method of simultaneously achieving simple structure and maximum similarity is the technique devised by Bloxom (1968). This technique simultaneously rotates different factor patterns to maximum similarity and varimax…

  17. Similarity between particles and bubbles as micro-additives in turbulent channel flow

    NASA Astrophysics Data System (ADS)

    Mito, Yoichi

    2015-11-01

    The acceleration of turbulent fluid flow in a vertical channel by the use of a uniform distribution of microparticles and of microbubbles has been examined by using a direct numerical simulation to calculate the fluid velocities seen by the additives. The flows considered are the downward gas flow to which solid particles of density ratio of 103 are added and the upward liquid flow to which bubbles of density ratio of 10-3 are added. Both additives, ranging in volume fraction up to 2 ×10-3 , are represented as solid spheres. The Froude numbers are chosen so as to have similar effects in both flows by the use of the same volume fraction of the additives. The fluid-phase momentum balance, integrated over the domain, is used to examine the changes in drag, wall friction and averaged feedback force of the non-stationary flow models. The feedback force per volume fraction is unchanged in the bubble flow. It decreases with increasing volume fraction and inertia of particles in the particle flow. Similarities between the two disperse flows are seen at small times for small volume fractions. Drag is reduced by both additives. The amount of reduced drag decreases with time at large times in the bubble flow, due to the increases in the accumulation of bubbles above walls. This work was supported by JSPS KAKENHI Grant Number 26420097.

  18. Explanation of non-additive effects in mixtures of similar mode of action chemicals.

    PubMed

    Kamo, Masashi; Yokomizo, Hiroyuki

    2015-09-01

    Many models have been developed to predict the combined effect of drugs and chemicals. Most models are classified into two additive models: independent action (IA) and concentration addition (CA). It is generally considered if the modes of action of chemicals are similar then the combined effect obeys CA; however, many empirical studies report nonlinear effects deviating from the predictions by CA. Such deviations are termed synergism and antagonism. Synergism, which leads to a stronger toxicity, requires more careful management, and hence it is important to understand how and which combinations of chemicals lead to synergism. In this paper, three types of chemical reactions are mathematically modeled and the cause of the nonlinear effects among chemicals with similar modes of action was investigated. Our results show that combined effects obey CA only when the modes of action are exactly the same. Contrary to existing knowledge, combined effects are generally nonlinear even if the modes of action of the chemicals are similar. Our results further show that the nonlinear effects vanish out when the chemical concentrations are low, suggesting that the current management procedure of assuming CA is rarely inappropriate because environmental concentrations of chemicals are generally low.

  19. Similar Verbal Fluency Patterns in Amnestic Mild Cognitive Impairment and Alzheimer's Disease

    PubMed Central

    Teng, Edmond; Leone-Friedman, Judith; Lee, Grace J.; Woo, Stephanie; Apostolova, Liana G.; Harrell, Shelly; Ringman, John M.; Lu, Po H.

    2013-01-01

    Disproportionately greater deficits in semantic relative to phonemic verbal fluency are seen in Alzheimer's disease (AD) and have been attributed to neurodegenerative changes in the temporal lobe. Amnestic (AMN) mild cognitive impairment (MCI), which often represents incipient AD, is also characterized by early temporal lobe neuropathology, but previous comparisons of verbal fluency between AD and AMN MCI have yielded mixed results. We examined semantic and phonemic verbal fluency performance in 399 individuals (78 AD, 138 AMN MCI, 72 non-amnestic MCI, and 111 cognitively normal controls). Similar verbal fluency patterns were seen in AMN MCI and AD; both groups exhibited disproportionately poorer performance on semantic verbal fluency relative to normal controls. However, relative verbal fluency indices performed more poorly than individual semantic or phonemic verbal fluency indices for discriminating AMN MCI or AD participants from normal controls, suggesting that they are unlikely to provide additional utility for predicting progression from MCI to AD. PMID:23752677

  20. Gender Similarity or Gender Difference? Contemporary Women's and Men's Career Patterns

    ERIC Educational Resources Information Center

    Whitmarsh, Lona; Wentworth, Diane Keyser

    2012-01-01

    Career development research has often explored gender differences in and development of career patterns (Gottfredson, 2006). Hyde's (2005) meta-analysis indicated that men and women shared more similarities than differences. Applying Hyde's gender similarities hypothesis to careers, the authors conducted a 2-stage study. Stage 1 was an analysis of…

  1. The importance of pattern similarity between Müllerian mimics in predator avoidance learning.

    PubMed

    Rowe, Candy; Lindström, Leena; Lyytinen, Anne

    2004-02-22

    Müllerian mimicry, where unpalatable prey share common warning patterns, has long fascinated evolutionary biologists. It is commonly assumed that Müllerian mimics benefit by sharing the costs of predator education, thus reducing per capita mortality, although there has been no direct test of this assumption. Here, we specifically measure the selection pressure exerted by avian predators on unpalatable prey with different degrees of visual similarity in their warning patterns. Using wild-caught birds foraging on novel patterned prey in the laboratory, we unexpectedly found that pattern similarity did not increase the speed of avoidance learning, and even dissimilar mimics shared the education of naive predators. This was a consistent finding across two different densities of unpalatable prey, although mortalities were lower at the higher density as expected. Interestingly, the mortalities of Müllerian mimics were affected by pattern similarity in the predicted way by the end of our experiment, although the result was not quite significant. This suggests that the benefits to Müllerian mimics may emerge only later in the learning process, and that predator experience of the patterns may affect the degree to which pattern similarity is important. This highlights the need to measure the behaviour of real predators if we are to understand fully the evolution of mimicry systems.

  2. Local similarity in organic crystals and the non-uniqueness of X-ray powder patterns.

    PubMed

    Karfunkel; Wilts; Hao; Iqbal; Mizuguchi; Wu

    1999-12-01

    Two new concepts for molecular solids, 'local similarity' and 'boundary-preserving isometry', are defined mathematically and a theorem which relates these concepts is formulated. 'Locally similar' solids possess an identical short-range structure and a 'boundary-preserving isometry' is a new mathematical operation on a finite region of a solid that transforms mathematically a given solid to a locally similar one. It is shown further that the existence of such a 'boundary-preserving isometry' in a given solid has infinitely many 'locally similar' solids as a consequence. Chemical implications, referring to the similarity of X-ray powder patterns and patent registration, are discussed as well. These theoretical concepts, which are first introduced in a schematic manner, are proved to exist in nature by the elucidation of the crystal structure of some diketopyrrolopyrrole (DPP) derivatives with surprisingly similar powder patterns. Although the available powder patterns were not indexable, the underlying crystals could be elucidated by using the new technique of ab initio prediction of possible polymorphs and a subsequent Rietveld refinement. Further ab initio packing calculations on other molecules reveal that 'local crystal similarity' is not restricted to DPP derivatives and should also be exhibited by other molecules such as quinacridones. The 'boundary-preserving isometry' is presented as a predictive tool for crystal engineering purposes and attempts to detect it in crystals of the Cambridge Structural Database (CSD) are reported.

  3. Ethanol and Cancer Induce Similar Changes on Protein Expression Pattern of Human Fibroblast Cell

    PubMed Central

    Zamanian–Azodi, Mona; Rezaei-Tavirani, Mostafa; Rahmati-Rad, Sara; Rezaei Tavirani, Majid

    2016-01-01

    Ethanol has a vast consumption around the world. Many researches confirmed some adverse effect of this component on human health. In addition, recent studies showed significant alteration in both cellular population, and protein profile of human foreskin fibroblast cell line (HFFF2) in the specific dosage of ethanol. Here, the role and interaction of some proteins (characterized by significant alteration in expression due to ethanol effect) analyzed by proteomics and evaluated by considering cancerous case. 2D-electrophoresis findings of comparison of normal fibroblast cells and treated fibroblast with 270 mM dosage of ethanol analyzed by using SameSpots software, R software, and Cytoscape for protein-protein interaction (PPI) investigation. Six proteins with significantly altered expression associated with fundamental properties in a cell identified in ethanol-treated sample. These include AnnexinA5, Heterogeneous nuclear ribonucleoprotein A1, Rho-GDP dissociation inhibitor, Cathepsin L, Cu/Zn-SOD, Rho-GDP dissociation inhibitor, and Serpin peptidase inhibitor. Surprisingly, all these proteins were down-regulated and this pattern is similar to nasopharyngeal carcinoma-associated stromal fibroblast sample. Additionally, protein-protein interaction (PPI) indicates that HNRNPA1, SERPINE1 are hub proteins. Once their expression alters, it can impose vast changes on other molecular function. Based on this approach, ethanol may target same pathways that are related to cancer onset. In addition, some epidemiologic studies proved that ethanol consumption is related to increment of cancer risk. Therefore, more investigation is required in this regard to elicit the feasible relationship. PMID:28228815

  4. Trait similarity patterns within grass and grasshopper communities: multitrophic community assembly at work.

    PubMed

    Van der Plas, F; Anderson, T M; Olff, H

    2012-04-01

    Trait-based community assembly theory suggests that trait variation among co-occurring species is shaped by two main processes: abiotic filtering, important in stressful environments and promoting similarity, and competition, more important in productive environments and promoting dissimilarity. Previous studies have indeed found trait similarity to decline along productivity gradients. However, these studies have always been done on single trophic levels. Here, we investigated how interactions between trophic levels affect trait similarity patterns along environmental gradients. We propose three hypotheses for the main drivers of trait similarity patterns of plants and herbivores along environmental gradients: (1) environmental control of both, (2) bottom-up control of herbivore trait variation, and (3) top-down control of grass trait variation. To test this, we collected data on the community composition and trait variation of grasses (41 species) and grasshoppers (53 species) in 50 plots in a South African savanna. Structural equation models were used to investigate how the range and spacing of within-community functional trait values of both grasses and their insect herbivores (grasshoppers; Acrididae) respond to (1) rainfall and fire frequency gradients and (2) the trait similarity patterns of the other trophic level. The analyses revealed that traits of co-occurring grasses became more similar toward lower rainfall and higher fire frequency (environmental control), while showing little evidence for top-down control. Grasshopper trait range patterns, on the other hand, were mostly directly driven by vegetation structure and grass trait range patterns (bottom-up control), while environmental factors had mostly indirect effects via plant traits. Our study shows the potential to expand trait-based community assembly theory to include trophic interactions.

  5. Gait Patterns in Twins with Cerebral Palsy: Similarities and Development over Time after Multilevel Surgery

    ERIC Educational Resources Information Center

    van Drongelen, Stefan; Dreher, Thomas; Heitzmann, Daniel W. W.; Wolf, Sebastian I.

    2013-01-01

    To examine gait patterns and gait quality, 7 twins with cerebral palsy were measured preoperatively and after surgical intervention. The aim was to study differences and/or similarities in gait between twins, the influence of personal characteristics and birth conditions, and to describe the development of gait over time after single event…

  6. Temporal Patterns in Bacterioplankton Community Composition in Three Reservoirs of Similar Trophic Status in Shenzhen, China

    PubMed Central

    Li, Jiancheng; Chen, Cheng; Lu, Jun; Lei, Anping; Hu, Zhangli

    2016-01-01

    The bacterioplankton community composition’s (BCC) spatial and temporal variation patterns in three reservoirs (Shiyan, Xikeng, and LuoTian Reservoir) of similar trophic status in Bao’an District, Shenzhen (China), were investigated using PCR amplification of the 16S rDNA gene and the denaturing gradient gel electrophoresis (DGGE) techniques. Water samples were collected monthly in each reservoir during 12 consecutive months. Distinct differences were detected in band number, pattern, and density of DGGE at different sampling sites and time points. Analysis of the DGGE fingerprints showed that changes in the bacterial community structure mainly varied with seasons, and the patterns of change indicated that seasonal forces might have a more significant impact on the BCC than eutrophic status in the reservoirs, despite the similar Shannon-Weiner index among the three reservoirs. The sequences obtained from excised bands were affiliated with Cyanobacteria, Firmicutes, Bacteriodetes, Acidobacteria, Actinobacteria, Planctomycetes, and Proteobacteria. PMID:27322295

  7. Similarity of relationship standards, couple communication patterns, and marital satisfaction among Chinese couples.

    PubMed

    Chi, Peilian; Epstein, Norman B; Fang, Xiaoyi; Lam, Debbie O B; Li, Xiaoming

    2013-10-01

    Prior research has indicated that partners' standards for their couple relationships are associated with their levels of marital satisfaction, both in terms of similarity between standards and the degree to which partners are able to resolve differences in their standards constructively. However, little is known about processes through which couples effectively cope with conflicting relationship standards. Furthermore, most research on relationship standards has been conducted in Western countries, and there is a need for more information about the role of this form of cognition in Asian and other cultures. In the present study, relationship standards and communication patterns were examined in relation to marital satisfaction among 297 community couples in a northern city in mainland China. Results indicated that the similarity of relationship standards of members of real couples was significantly higher than randomly matched male-female pairs. A hypothesized conceptual model predicting marital satisfaction from partners' similarity of relationship standards and communication patterns was tested using structural equation modeling. Similarity of relationship standards can affect couple's marital satisfaction indirectly, through perceived communication patterns. The interdependence between husbands' and wives' aspects of relationship functioning also are examined and discussed.

  8. Idiosyncratic Patterns of Representational Similarity in Prefrontal Cortex Predict Attentional Performance.

    PubMed

    Lee, Jeongmi; Geng, Joy J

    2017-02-01

    The efficiency of finding an object in a crowded environment depends largely on the similarity of nontargets to the search target. Models of attention theorize that the similarity is determined by representations stored within an "attentional template" held in working memory. However, the degree to which the contents of the attentional template are individually unique and where those idiosyncratic representations are encoded in the brain are unknown. We investigated this problem using representational similarity analysis of human fMRI data to measure the common and idiosyncratic representations of famous face morphs during an identity categorization task; data from the categorization task were then used to predict performance on a separate identity search task. We hypothesized that the idiosyncratic categorical representations of the continuous face morphs would predict their distractability when searching for each target identity. The results identified that patterns of activation in the lateral prefrontal cortex (LPFC) as well as in face-selective areas in the ventral temporal cortex were highly correlated with the patterns of behavioral categorization of face morphs and search performance that were common across subjects. However, the individually unique components of the categorization behavior were reliably decoded only in right LPFC. Moreover, the neural pattern in right LPFC successfully predicted idiosyncratic variability in search performance, such that reaction times were longer when distractors had a higher probability of being categorized as the target identity. These results suggest that the prefrontal cortex encodes individually unique components of categorical representations that are also present in attentional templates for target search.

  9. Similarity-dissimilarity plot for visualization of high dimensional data in biomedical pattern classification.

    PubMed

    Arif, Muhammad

    2012-06-01

    In pattern classification problems, feature extraction is an important step. Quality of features in discriminating different classes plays an important role in pattern classification problems. In real life, pattern classification may require high dimensional feature space and it is impossible to visualize the feature space if the dimension of feature space is greater than four. In this paper, we have proposed a Similarity-Dissimilarity plot which can project high dimensional space to a two dimensional space while retaining important characteristics required to assess the discrimination quality of the features. Similarity-dissimilarity plot can reveal information about the amount of overlap of features of different classes. Separable data points of different classes will also be visible on the plot which can be classified correctly using appropriate classifier. Hence, approximate classification accuracy can be predicted. Moreover, it is possible to know about whom class the misclassified data points will be confused by the classifier. Outlier data points can also be located on the similarity-dissimilarity plot. Various examples of synthetic data are used to highlight important characteristics of the proposed plot. Some real life examples from biomedical data are also used for the analysis. The proposed plot is independent of number of dimensions of the feature space.

  10. Gait patterns in twins with cerebral palsy: similarities and development over time after multilevel surgery.

    PubMed

    van Drongelen, Stefan; Dreher, Thomas; Heitzmann, Daniel W W; Wolf, Sebastian I

    2013-05-01

    To examine gait patterns and gait quality, 7 twins with cerebral palsy were measured preoperatively and after surgical intervention. The aim was to study differences and/or similarities in gait between twins, the influence of personal characteristics and birth conditions, and to describe the development of gait over time after single event multilevel surgery. A standardized clinical exam and a three-dimensional gait analysis were performed. Gait patterns were classified according to Sutherland and Davids, and the Gillette Gait Index was calculated as a global measure of the gait impairment. Next to subject characteristics at time of first measurement, and at time of birth, birth conditions were collected. Gait patterns were determined as crouch gait in 13 legs, as stiff gait in 6 legs and as jump gait in 8 legs. One leg showed a normal gait pattern. The knee flexion-extension angle correlated most constant with the knee flexion-extension angle of the contralateral leg (range 0.91-0.99). Correlations with the legs of the sibling showed variable correlations (range 0.44-0.99); with all other legs medium to high correlations of 0.73-0.91 were found. The Gillette Gait Index was found to initially decrease after surgical intervention. Similar correlations were found between twins or between legs for the gait pattern expressed by the knee flexion-extension angle, and the Gillette Gait Index improved after surgery. It seems that gait quality in twins with cerebral palsy is characterized predominantly by the traumatic disorder: genetic dispositions and personal characteristics only play a negligible role.

  11. Neural pattern similarity between contra- and ipsilateral movements in high-frequency band of human electrocorticograms.

    PubMed

    Fujiwara, Yusuke; Matsumoto, Riki; Nakae, Takuro; Usami, Kiyohide; Matsuhashi, Masao; Kikuchi, Takayuki; Yoshida, Kazumichi; Kunieda, Takeharu; Miyamoto, Susumu; Mima, Tatsuya; Ikeda, Akio; Osu, Rieko

    2017-02-15

    The cortical motor areas are activated not only during contralateral limb movements but also during ipsilateral limb movements. Although these ipsilateral activities have been observed in several brain imaging studies, their functional role is poorly understood. Due to its high temporal resolution and low susceptibility to artifacts from body movements, the electrocorticogram (ECoG) is an advantageous measurement method for assessing the human brain function of motor behaviors. Here, we demonstrate that contra- and ipsilateral movements share a similarity in the high-frequency band of human ECoG signals. The ECoG signals were measured from the unilateral sensorimotor cortex while patients conducted self-paced movements of different body parts, contra- or ipsilateral to the measurement side. The movement categories (wrist, shoulder, or ankle) of ipsilateral movements were decoded as accurately as those of contralateral movements from spatial patterns of the high-frequency band of the precentral motor area (the primary motor and premotor areas). The decoder, trained in the high-frequency band of ipsilateral movements generalized to contralateral movements, and vice versa, confirmed that the activity patterns related to ipsilateral limb movements were similar to contralateral ones in the precentral motor area. Our results suggest that the high-frequency band activity patterns of ipsilateral and contralateral movements might be functionally coupled to control limbs, even during unilateral movements.

  12. A modified statistical pattern recognition approach to measuring the crosslinguistic similarity of Mandarin and English vowels.

    PubMed

    Thomson, Ron I; Nearey, Terrance M; Derwing, Tracey M

    2009-09-01

    This study describes a statistical approach to measuring crosslinguistic vowel similarity and assesses its efficacy in predicting L2 learner behavior. In the first experiment, using linear discriminant analysis, relevant acoustic variables from vowel productions of L1 Mandarin and L1 English speakers were used to train a statistical pattern recognition model that simultaneously comprised both Mandarin and English vowel categories. The resulting model was then used to determine what categories novel Mandarin and English vowel productions most resembled. The extent to which novel cases were classified as members of a competing language category provided a means for assessing the crosslinguistic similarity of Mandarin and English vowels. In a second experiment, L2 English learners imitated English vowels produced by a native speaker of English. The statistically defined similarity between Mandarin and English vowels quite accurately predicted L2 learner behavior; the English vowel elicitation stimuli deemed most similar to Mandarin vowels were more likely to elicit L2 productions that were recognized as a Mandarin category; English stimuli that were less similar to Mandarin vowels were more likely to elicit L2 productions that were recognized as new or emerging categories.

  13. Similarity analysis of PAH and PCB bioaccumulation patterns in sediment-exposed Chironomus tentans larvae

    SciTech Connect

    Wood, L.W.; O`Keefe, P.; Bush, B.

    1997-02-01

    Larvae of the aquatic insect Chironomus tentans were exposed at the third or fourth instar stage to sediments collected near the outfalls of two aluminum foundries and an aluminum fabrication plant. Biota and sediment bioaccumulation factors (BFs), based on wet tissue weights and dry sediment weights, ranged from 0.07 to 0.27 for polycyclic aromatic hydrocarbons (PAHs) and from 0.22 to 1.42 for polychlorinated biphenyls (PCBs). A higher rate of metabolism of PAHs compared with PCBs could explain the differences in BF values for the two groups of chemicals. It was found, using community similarity procedures from the field of ecology, that the congener patterns for PAHs and PCBs bioaccumulated by the larvae differed from the pattern of the same compounds in the sediments to which they were exposed. Affinity analysis indicated that the larvae favored the higher molecular weight PAH and PCB congeners. Preferential ingestion of sediments with defined particle size ranges, metabolism, and octanol/water partition coefficients (log K{sub ow}) are factors that may have influenced the bioaccumulation patterns. However, no single factor could adequately account for the differences between the larval and sediment patterns.

  14. Children's patterns of reasoning about reading and addition concepts.

    PubMed

    Farrington-Flint, Lee; Canobi, Katherine H; Wood, Clare; Faulkner, Dorothy

    2010-06-01

    Children's reasoning was examined within two educational contexts (word reading and addition) so as to understand the factors that contribute to relational reasoning in the two domains. Sixty-seven 5- to 7-year-olds were given a series of related words to read or single-digit addition items to solve (interspersed with unrelated items). The frequency, accuracy, and response times of children's self-reports on the conceptually related items provided a measure of relational reasoning, while performance on the unrelated addition and reading items provided a measure of procedural skill. The results indicated that the children's ability to use conceptual relations to solve both reading and addition problems enhanced speed and accuracy levels, increased with age, and was related to procedural skill. However, regression analyses revealed that domain-specific competencies can best explain the use of conceptual relations in both reading and addition. Moreover, a cluster analysis revealed that children differ according to the academic domain in which they first apply conceptual relations and these differences are related to individual variation in their procedural skills within these particular domains. These results highlight the developmental significance of relational reasoning in the context of reading and addition and underscore the importance of concept-procedure links in explaining children's literacy and arithmetical development.

  15. Global neural pattern similarity as a common basis for categorization and recognition memory.

    PubMed

    Davis, Tyler; Xue, Gui; Love, Bradley C; Preston, Alison R; Poldrack, Russell A

    2014-05-28

    Familiarity, or memory strength, is a central construct in models of cognition. In previous categorization and long-term memory research, correlations have been found between psychological measures of memory strength and activation in the medial temporal lobes (MTLs), which suggests a common neural locus for memory strength. However, activation alone is insufficient for determining whether the same mechanisms underlie neural function across domains. Guided by mathematical models of categorization and long-term memory, we develop a theory and a method to test whether memory strength arises from the global similarity among neural representations. In human subjects, we find significant correlations between global similarity among activation patterns in the MTLs and both subsequent memory confidence in a recognition memory task and model-based measures of memory strength in a category learning task. Our work bridges formal cognitive theories and neuroscientific models by illustrating that the same global similarity computations underlie processing in multiple cognitive domains. Moreover, by establishing a link between neural similarity and psychological memory strength, our findings suggest that there may be an isomorphism between psychological and neural representational spaces that can be exploited to test cognitive theories at both the neural and behavioral levels.

  16. Spatial Attention Evokes Similar Activation Patterns for Visual and Auditory Stimuli

    PubMed Central

    Smith, David V.; Davis, Ben; Niu, Kathy; Healy, Eric W.; Bonilha, Leonardo; Fridriksson, Julius; Morgan, Paul S.; Rorden, Chris

    2010-01-01

    Neuroimaging studies suggest that a fronto-parietal network is activated when we expect visual information to appear at a specific spatial location. Here we examined whether a similar network is involved for auditory stimuli. We used sparse fMRI to infer brain activation while participants performed analogous visual and auditory tasks. On some trials, participants were asked to discriminate the elevation of a peripheral target. On other trials, participants made a nonspatial judgment. We contrasted trials where the participants expected a peripheral spatial target to those where they were cued to expect a central target. Crucially, our statistical analyses were based on trials where stimuli were anticipated but not presented, allowing us to directly infer perceptual orienting independent of perceptual processing. This is the first neuroimaging study to use an orthogonal-cuing paradigm (with cues predicting azimuth and responses involving elevation discrimination). This aspect of our paradigm is important, as behavioral cueing effects in audition are classically only observed when participants are asked to make spatial judgments. We observed similar fronto-parietal activation for both vision and audition. In a second experiment that controlled for stimulus properties and task difficulty, participants made spatial and temporal discriminations about musical instruments. We found that the pattern of brain activation for spatial selection of auditory stimuli was remarkably similar to what we found in our first experiment. Collectively, these results suggest that the neural mechanisms supporting spatial attention are largely similar across both visual and auditory modalities. PMID:19400684

  17. Phasic activation of ventral tegmental neurons increases response and pattern similarity in prefrontal cortex neurons

    PubMed Central

    Iwashita, Motoko

    2014-01-01

    Dopamine is critical for higher neural processes and modifying the activity of the prefrontal cortex (PFC). However, the mechanism of dopamine contribution to the modification of neural representation is unclear. Using in vivo two-photon population Ca2+ imaging in awake mice, this study investigated how neural representation of visual input to PFC neurons is regulated by dopamine. Phasic stimulation of dopaminergic neurons in the ventral tegmental area (VTA) evoked prolonged Ca2+ transients, lasting ∼30 s in layer 2/3 neurons of the PFC, which are regulated by a dopamine D1 receptor-dependent pathway. Furthermore, only a conditioning protocol with visual sensory input applied 0.5 s before the VTA dopaminergic input could evoke enhanced Ca2+ transients and increased pattern similarity (or establish a neural representation) of PFC neurons to the same sensory input. By increasing both the level of neuronal response and pattern similarity, dopaminergic input may establish robust and reliable cortical representation. DOI: http://dx.doi.org/10.7554/eLife.02726.001 PMID:25269147

  18. Same or different? A neural circuit mechanism of similarity-based pattern match decision making.

    PubMed

    Engel, Tatiana A; Wang, Xiao-Jing

    2011-05-11

    The ability to judge whether sensory stimuli match an internally represented pattern is central to many brain functions. To elucidate the underlying mechanism, we developed a neural circuit model for match/nonmatch decision making. At the core of this model is a "comparison circuit" consisting of two distinct neural populations: match enhancement cells show higher firing response for a match than a nonmatch to the target pattern, and match suppression cells exhibit the opposite trend. We propose that these two neural pools emerge from inhibition-dominated recurrent dynamics and heterogeneous top-down excitation from a working memory circuit. A downstream system learns, through plastic synapses, to extract the necessary information to make match/nonmatch decisions. The model accounts for key physiological observations from behaving monkeys in delayed match-to-sample experiments, including tasks that require more than simple feature match (e.g., when BB in ABBA sequence must be ignored). A testable prediction is that magnitudes of match enhancement and suppression neural signals are parametrically tuned to the similarity between compared patterns. Furthermore, the same neural signals from the comparison circuit can be used differently in the decision process for different stimulus statistics or tasks; reward-dependent synaptic plasticity enables decision neurons to flexibly adjust the readout scheme to task demands, whereby the most informative neural signals have the highest impact on the decision.

  19. Similar lymphocytic infiltration pattern in primary breast cancer and their corresponding distant metastases.

    PubMed

    Sobottka, Bettina; Pestalozzi, Bernhard; Fink, Daniel; Moch, Holger; Varga, Zsuzsanna

    2016-06-01

    Tumor infiltrating lymphocytes in primary breast cancer (TIL) are acknowledged measures of disease free survival (DFS) in adjuvant and neoadjuvant settings. Little is known about the biology of metastasis infiltrating lymphocytes (mTIL) although the local immunity of the metastatic site may critically influence the infiltrate composite. To address this question, we compared mTIL with their matched TIL in 87 breast cancer patients and their corresponding distant metastasis at four different anatomical locations. Sections of surgical specimen were immunohistochemically analyzed for CD4(+), CD8(+) and CD20(+) lymphocytes in three different tumor compartments: intratumoral lymphocytes (iTIL) defined as lymphocytes in direct contact with breast cancer cells, stromal lymphocytes (sTIL) located within the intratumoral stromal tissue and invasive-margin lymphocytes (imTIL). Overall, we found fewer (p < 0.001) mTIL than TIL. Within the tumor compartments, imTIL were more frequent than sTIL and iTIL both within metastases and the matched primary tumors (PT) (p < 0.001). CD4(+) T cells were more numerous than CD8(+) T cells and CD20(+) B cells (p < 0.001). There was a similar pattern in PT and their corresponding metastasis. Only patients with brain metastases differed from the others displaying less CD20(+) B cells at the infiltrative margin of the PT (p < 0.05). In summary, mTIL were significantly reduced within metastases but still mirrored the infiltrate pattern of the PT, interestingly regardless of the metastatic anatomical locations investigated. Our results suggest that the PT assigns the infiltrating lymphocyte pattern resumed at the metastatic site.

  20. Similar lymphocytic infiltration pattern in primary breast cancer and their corresponding distant metastases

    PubMed Central

    Sobottka, Bettina; Pestalozzi, Bernhard; Fink, Daniel; Moch, Holger; Varga, Zsuzsanna

    2016-01-01

    ABSTRACT Tumor infiltrating lymphocytes in primary breast cancer (TIL) are acknowledged measures of disease free survival (DFS) in adjuvant and neoadjuvant settings. Little is known about the biology of metastasis infiltrating lymphocytes (mTIL) although the local immunity of the metastatic site may critically influence the infiltrate composite. To address this question, we compared mTIL with their matched TIL in 87 breast cancer patients and their corresponding distant metastasis at four different anatomical locations. Sections of surgical specimen were immunohistochemically analyzed for CD4+, CD8+ and CD20+ lymphocytes in three different tumor compartments: intratumoral lymphocytes (iTIL) defined as lymphocytes in direct contact with breast cancer cells, stromal lymphocytes (sTIL) located within the intratumoral stromal tissue and invasive-margin lymphocytes (imTIL). Overall, we found fewer (p < 0.001) mTIL than TIL. Within the tumor compartments, imTIL were more frequent than sTIL and iTIL both within metastases and the matched primary tumors (PT) (p < 0.001). CD4+ T cells were more numerous than CD8+ T cells and CD20+ B cells (p < 0.001). There was a similar pattern in PT and their corresponding metastasis. Only patients with brain metastases differed from the others displaying less CD20+ B cells at the infiltrative margin of the PT (p < 0.05). In summary, mTIL were significantly reduced within metastases but still mirrored the infiltrate pattern of the PT, interestingly regardless of the metastatic anatomical locations investigated. Our results suggest that the PT assigns the infiltrating lymphocyte pattern resumed at the metastatic site. PMID:27471624

  1. Patterns in Gut Microbiota Similarity Associated with Degree of Sociality among Sex Classes of a Neotropical Primate.

    PubMed

    Amato, Katherine R; Van Belle, Sarie; Di Fiore, Anthony; Estrada, Alejandro; Stumpf, Rebecca; White, Bryan; Nelson, Karen E; Knight, Rob; Leigh, Steven R

    2017-01-26

    Studies of human and domestic animal models indicate that related individuals and those that spend the most time in physical contact typically have more similar gut microbial communities. However, few studies have examined these factors in wild mammals where complex social dynamics and a variety of interacting environmental factors may impact the patterns observed in controlled systems. Here, we explore the effect of host kinship and time spent in social contact on the gut microbiota of wild, black howler monkeys (Alouatta pigra). Our results indicate that closely related individuals had less similar gut microbial communities than non-related individuals. However, the effect was small. In contrast, as previously reported in baboons and chimpanzees, individuals that spent more time in contact (0 m) and close proximity (0-1 m) had more similar gut microbial communities. This pattern was driven by adult female-adult female dyads, which generally spend more time in social contact than adult male-adult male dyads or adult male-adult female dyads. Relative abundances of individual microbial genera such as Bacteroides, Clostridium, and Streptococcus were also more similar in individuals that spent more time in contact or close proximity. Overall, our data suggest that even in arboreal primates that live in small social groups and spend a relatively low proportion of their time in physical contact, social interactions are associated with variation in gut microbiota composition. Additionally, these results demonstrate that within a given host species, subgroups of individuals may interact with the gut microbiota differently.

  2. Searching for Contracting Patterns over Time: Do Prime Contractor and Subcontractor Relations Follow Similar Patterns for Professional Services Provision?

    ERIC Educational Resources Information Center

    Ponomariov, Branco; Kingsley, Gordon; Boardman, Craig

    2011-01-01

    This paper compares over a 12-year period (1) patterns of contracting between a state transportation agency and its prime contractors providing engineering design services with (2) patterns between these prime contractors and their subcontractors. We find evidence of different contracting patterns at each level that emerge over time and coexist in…

  3. Very similar spacing-effect patterns in very different learning/practice domains.

    PubMed

    Kornmeier, Jürgen; Spitzer, Manfred; Sosic-Vasic, Zrinka

    2014-01-01

    Temporally distributed ("spaced") learning can be twice as efficient as massed learning. This "spacing effect" occurs with a broad spectrum of learning materials, with humans of different ages, with non-human vertebrates and also invertebrates. This indicates, that very basic learning mechanisms are at work ("generality"). Although most studies so far focused on very narrow spacing interval ranges, there is some evidence for a non-monotonic behavior of this "spacing effect" ("nonlinearity") with optimal spacing intervals at different time scales. In the current study we focused both the nonlinearity aspect by using a broad range of spacing intervals and the generality aspect by using very different learning/practice domains: Participants learned German-Japanese word pairs and performed visual acuity tests. For each of six groups we used a different spacing interval between learning/practice units from 7 min to 24 h in logarithmic steps. Memory retention was studied in three consecutive final tests, one, seven and 28 days after the final learning unit. For both the vocabulary learning and visual acuity performance we found a highly significant effect of the factor spacing interval on the final test performance. In the 12 h-spacing-group about 85% of the learned words stayed in memory and nearly all of the visual acuity gain was preserved. In the 24 h-spacing-group, in contrast, only about 33% of the learned words were retained and the visual acuity gain dropped to zero. The very similar patterns of results from the two very different learning/practice domains point to similar underlying mechanisms. Further, our results indicate spacing in the range of 12 hours as optimal. A second peak may be around a spacing interval of 20 min but here the data are less clear. We discuss relations between our results and basic learning at the neuronal level.

  4. Similar Personality Patterns Are Associated with Empathy in Four Different Countries

    PubMed Central

    Melchers, Martin C.; Li, Mei; Haas, Brian W.; Reuter, Martin; Bischoff, Lena; Montag, Christian

    2016-01-01

    Empathy is an important human ability associated with successful social interaction. It is currently unclear how to optimally measure individual differences in empathic processing. Although the Big Five model of personality is an effective model to explain individual differences in human experience and behavior, its relation to measures of empathy is currently not well understood. Therefore, the present study was designed to investigate the relationship between the Big Five personality concept and two commonly used measures for empathy [Empathy Quotient (EQ), Interpersonal Reactivity Index (IRI)] in four samples from China, Germany, Spain, and the United States of America. This approach was designed to advance the way the Big Five personality model can be used to measure empathy. We found evidence of medium effect sizes for associations between personality and empathy, with agreeableness and conscientiousness as the most important predictors of affective and cognitive empathy (measured by the respective IRI subscales) as well as for a one-dimensional empathy score (measured by the EQ). Empathy in a fictional context was most closely related to openness to experience while personal distress was first of all related to neuroticism. In terms of culture, we did not observe any distinct pattern concerning cultural differences. These results support the cross-cultural applicability of the EQ and the IRI and indicate structurally similar associations between personality and empathy across cultures. PMID:27014115

  5. Dispersal similarly shapes both population genetics and community patterns in the marine realm

    PubMed Central

    Chust, Guillem; Villarino, Ernesto; Chenuil, Anne; Irigoien, Xabier; Bizsel, Nihayet; Bode, Antonio; Broms, Cecilie; Claus, Simon; Fernández de Puelles, María L.; Fonda-Umani, Serena; Hoarau, Galice; Mazzocchi, Maria G.; Mozetič, Patricija; Vandepitte, Leen; Veríssimo, Helena; Zervoudaki, Soultana; Borja, Angel

    2016-01-01

    Dispersal plays a key role to connect populations and, if limited, is one of the main processes to maintain and generate regional biodiversity. According to neutral theories of molecular evolution and biodiversity, dispersal limitation of propagules and population stochasticity are integral to shaping both genetic and community structure. We conducted a parallel analysis of biological connectivity at genetic and community levels in marine groups with different dispersal traits. We compiled large data sets of population genetic structure (98 benthic macroinvertebrate and 35 planktonic species) and biogeographic data (2193 benthic macroinvertebrate and 734 planktonic species). We estimated dispersal distances from population genetic data (i.e., FST vs. geographic distance) and from β-diversity at the community level. Dispersal distances ranked the biological groups in the same order at both genetic and community levels, as predicted by organism dispersal ability and seascape connectivity: macrozoobenthic species without dispersing larvae, followed by macrozoobenthic species with dispersing larvae and plankton (phyto- and zooplankton). This ranking order is associated with constraints to the movement of macrozoobenthos within the seabed compared with the pelagic habitat. We showed that dispersal limitation similarly determines the connectivity degree of communities and populations, supporting the predictions of neutral theories in marine biodiversity patterns. PMID:27344967

  6. Dispersal similarly shapes both population genetics and community patterns in the marine realm

    NASA Astrophysics Data System (ADS)

    Chust, Guillem; Villarino, Ernesto; Chenuil, Anne; Irigoien, Xabier; Bizsel, Nihayet; Bode, Antonio; Broms, Cecilie; Claus, Simon; Fernández de Puelles, María L.; Fonda-Umani, Serena; Hoarau, Galice; Mazzocchi, Maria G.; Mozetič, Patricija; Vandepitte, Leen; Veríssimo, Helena; Zervoudaki, Soultana; Borja, Angel

    2016-06-01

    Dispersal plays a key role to connect populations and, if limited, is one of the main processes to maintain and generate regional biodiversity. According to neutral theories of molecular evolution and biodiversity, dispersal limitation of propagules and population stochasticity are integral to shaping both genetic and community structure. We conducted a parallel analysis of biological connectivity at genetic and community levels in marine groups with different dispersal traits. We compiled large data sets of population genetic structure (98 benthic macroinvertebrate and 35 planktonic species) and biogeographic data (2193 benthic macroinvertebrate and 734 planktonic species). We estimated dispersal distances from population genetic data (i.e., FST vs. geographic distance) and from β-diversity at the community level. Dispersal distances ranked the biological groups in the same order at both genetic and community levels, as predicted by organism dispersal ability and seascape connectivity: macrozoobenthic species without dispersing larvae, followed by macrozoobenthic species with dispersing larvae and plankton (phyto- and zooplankton). This ranking order is associated with constraints to the movement of macrozoobenthos within the seabed compared with the pelagic habitat. We showed that dispersal limitation similarly determines the connectivity degree of communities and populations, supporting the predictions of neutral theories in marine biodiversity patterns.

  7. Dispersal similarly shapes both population genetics and community patterns in the marine realm.

    PubMed

    Chust, Guillem; Villarino, Ernesto; Chenuil, Anne; Irigoien, Xabier; Bizsel, Nihayet; Bode, Antonio; Broms, Cecilie; Claus, Simon; Fernández de Puelles, María L; Fonda-Umani, Serena; Hoarau, Galice; Mazzocchi, Maria G; Mozetič, Patricija; Vandepitte, Leen; Veríssimo, Helena; Zervoudaki, Soultana; Borja, Angel

    2016-06-27

    Dispersal plays a key role to connect populations and, if limited, is one of the main processes to maintain and generate regional biodiversity. According to neutral theories of molecular evolution and biodiversity, dispersal limitation of propagules and population stochasticity are integral to shaping both genetic and community structure. We conducted a parallel analysis of biological connectivity at genetic and community levels in marine groups with different dispersal traits. We compiled large data sets of population genetic structure (98 benthic macroinvertebrate and 35 planktonic species) and biogeographic data (2193 benthic macroinvertebrate and 734 planktonic species). We estimated dispersal distances from population genetic data (i.e., FST vs. geographic distance) and from β-diversity at the community level. Dispersal distances ranked the biological groups in the same order at both genetic and community levels, as predicted by organism dispersal ability and seascape connectivity: macrozoobenthic species without dispersing larvae, followed by macrozoobenthic species with dispersing larvae and plankton (phyto- and zooplankton). This ranking order is associated with constraints to the movement of macrozoobenthos within the seabed compared with the pelagic habitat. We showed that dispersal limitation similarly determines the connectivity degree of communities and populations, supporting the predictions of neutral theories in marine biodiversity patterns.

  8. Memory Reactivation Predicts Resistance to Retroactive Interference: Evidence from Multivariate Classification and Pattern Similarity Analyses

    PubMed Central

    Rugg, Michael D.

    2016-01-01

    Memory reactivation—the reinstatement of processes and representations engaged when an event is initially experienced—is believed to play an important role in strengthening and updating episodic memory. The present study examines how memory reactivation during a potentially interfering event influences memory for a previously experienced event. Participants underwent fMRI during the encoding phase of an AB/AC interference task in which some words were presented twice in association with two different encoding tasks (AB and AC trials) and other words were presented once (DE trials). The later memory test required retrieval of the encoding tasks associated with each of the study words. Retroactive interference was evident for the AB encoding task and was particularly strong when the AC encoding task was remembered rather than forgotten. We used multivariate classification and pattern similarity analysis (PSA) to measure reactivation of the AB encoding task during AC trials. The results demonstrated that reactivation of generic task information measured with multivariate classification predicted subsequent memory for the AB encoding task regardless of whether interference was strong and weak (trials for which the AC encoding task was remembered or forgotten, respectively). In contrast, reactivation of neural patterns idiosyncratic to a given AB trial measured with PSA only predicted memory when the strength of interference was low. These results suggest that reactivation of features of an initial experience shared across numerous events in the same category, but not features idiosyncratic to a particular event, are important in resisting retroactive interference caused by new learning. SIGNIFICANCE STATEMENT Reactivating a previously encoded memory is believed to provide an opportunity to strengthen the memory, but also to return the memory to a labile state, making it susceptible to interference. However, there is debate as to how memory reactivation elicited by

  9. Local Action with Global Impact: Highly Similar Infection Patterns of Human Viruses and Bacteriophages.

    PubMed

    Mariano, Rachelle; Khuri, Sawsan; Uetz, Peter; Wuchty, Stefan

    2016-01-01

    The investigation of host-pathogen interaction interfaces and their constituent factors is crucial for our understanding of an organism's pathogenesis. Here, we explored the interactomes of HIV, hepatitis C virus, influenza A virus, human papillomavirus, herpes simplex virus, and vaccinia virus in a human host by analyzing the combined sets of virus targets and human genes that are required for viral infection. We also considered targets and required genes of bacteriophages lambda and T7 infection in Escherichia coli. We found that targeted proteins and their immediate network neighbors significantly pool with proteins required for infection and essential for cell growth, forming large connected components in both the human and E. coli protein interaction networks. The impact of both viruses and phages on their protein targets appears to extend to their network neighbors, as these are enriched with topologically central proteins that have a significant disruptive topological effect and connect different protein complexes. Moreover, viral and phage targets and network neighbors are enriched with transcription factors, methylases, and acetylases in human viruses, while such interactions are much less prominent in bacteriophages. IMPORTANCE While host-virus interaction interfaces have been previously investigated, relatively little is known about the indirect interactions of pathogen and host proteins required for viral infection and host cell function. Therefore, we investigated the topological relationships of human and bacterial viruses and how they interact with their hosts. We focused on those host proteins that are directly targeted by viruses, those that are required for infection, and those that are essential for both human and bacterial cells (here, E. coli). Generally, we observed that targeted, required, and essential proteins in both hosts interact in a highly intertwined fashion. While there exist highly similar topological patterns, we found that human

  10. MicroPattern: a web-based tool for microbe set enrichment analysis and disease similarity calculation based on a list of microbes

    PubMed Central

    Ma, Wei; Huang, Chuanbo; Zhou, Yuan; Li, Jianwei; Cui, Qinghua

    2017-01-01

    The microbiota colonized on human body is renowned as “a forgotten organ” due to its big impacts on human health and disease. Recently, microbiome studies have identified a large number of microbes differentially regulated in a variety of conditions, such as disease and diet. However, methods for discovering biological patterns in the differentially regulated microbes are still limited. For this purpose, here, we developed a web-based tool named MicroPattern to discover biological patterns for a list of microbes. In addition, MicroPattern implemented and integrated an algorithm we previously presented for the calculation of disease similarity based on disease-microbe association data. MicroPattern first grouped microbes into different sets based on the associated diseases and the colonized positions. Then, for a given list of microbes, MicroPattern performed enrichment analysis of the given microbes on all of the microbe sets. Moreover, using MicroPattern, we can also calculate disease similarity based on the shared microbe associations. Finally, we confirmed the accuracy and usefulness of MicroPattern by applying it to the changed microbes under the animal-based diet condition. MicroPattern is freely available at http://www.cuilab.cn/micropattern. PMID:28071710

  11. Similar patterns of infection with bovine foamy virus in experimentally inoculated calves and sheep.

    PubMed

    Materniak, Magdalena; Hechler, Torsten; Löchelt, Martin; Kuzmak, Jacek

    2013-03-01

    Foamy viruses (FVs) are the least known retroviruses commonly found in primates, cats, horses, and cattle. Although FVs are considered apathogenic, simian and feline FVs have been shown to be associated with some transient health abnormalities in animal models. Currently, data regarding the course of infection with bovine FV (BFV) are not available. In this study, we conducted experimental infections of natural (cattle) and heterologous (sheep) hosts with the BFV(100) isolate and monitored infection patterns in both hosts during the early phase postinoculation as well as after long-term infection. Four calves and six sheep inoculated with BFV(100) showed no signs of pathology but developed persistent infection, as confirmed by virus rescue, consistent detection of BFV-specific antibodies, and presence of viral DNA. In both hosts, antibodies against BFV Gag and Bet appeared early after infection and persisted at high and stable levels while seroreactivity toward Env was consistently detectable only in BFV-infected sheep. Interestingly, the BFV proviral DNA load was highest in lung, spleen, and liver and moderate in leukocytes, while salivary glands contained either low or undetectable DNA loads in calves or sheep, respectively. Additionally, comparison of partial BFV sequences from inoculum and infected animals demonstrated very limited changes after long-term infection in the heterologous host, clearly less than those found in BFV field isolates. The persistence of BFV infection in both hosts suggests full replication competence of the BFV(100) isolate with no requirement of genetic adaptation for productive replication in the authentic and even in a heterologous host.

  12. The pattern of factor IX germ-line mutation in Asians is similar to that of Caucasians.

    PubMed Central

    Bottema, C D; Ketterling, R P; Yoon, H S; Sommer, S S

    1990-01-01

    To begin documenting the pattern of germ-line mutations in different human races, we have delineated the mutation in nine Korean families with hemophilia B by direct genomic sequencing of the regions of likely functional significance in the factor IX gene. An evaluation of these mutations in combination with previously described point mutations in the factor IX gene of Asians indicates that transitions predominate followed by transversions and microdeletions/insertions. Transitions at the dinucleotide CpG are a dramatic hot spot of mutation. This pattern of mutation is very similar to that observed in Caucasians with hemophilia B, despite the many differences between Asians (mostly Koreans) and Caucasians in diet, environment and cultural life-styles. The similarity may reflect the predominance of endogenous processes or ubiquitous mutagens rather than specific mutagens in the environment. The following additional conclusions emerge: (1) The missense mutations in Asians occur at evolutionarily conserved amino acids. When combined with the previous data this makes it likely that more than two-thirds of the missense mutations which could possibly occur at nonconserved amino acids do not cause hemophilia B. (2) Surprisingly, a change in the sixth base of the intron 2 donor splice-junction sequence is associated with severe disease in HB 74/77. (3) Direct carrier testing of nine Korean families demonstrates that the stability of DNA at ambient temperature in blood with the anticoagulant ACD solution B makes it feasible for a diagnostic laboratory to perform such testing at a distance of 7,000 miles. Carrier testing revealed that the mutation in HB78 arose in his mother's germ-line.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:2220823

  13. Regional Similarities and Consistent Patterns of Local Variation in Beach Sand Bacterial Communities throughout the Northern Hemisphere

    PubMed Central

    Staley, Christopher

    2016-01-01

    ABSTRACT Recent characterization of the bacterial community structure in beach sands has revealed patterns of biogeography similar to those observed in aquatic environments. Studies to date, however, have mainly focused on subtidal sediments from marine beaches. Here, we investigate the bacterial diversity, using Illumina-based sequencing of the V5-V6 region of the 16S rRNA gene, at 11 beaches representing those next to the Great Lakes, Florida, and the Pacific Ocean. The alpha diversity differed significantly among regions (P < 0.0001), while the within-region diversity was more similar. The beta diversity also differed by region (P < 0.001), where freshwater sands had significantly higher abundances of taxa within the Actinobacteria, Betaproteobacteria, and Verrucomicrobia than marine environments. In contrast, marine sands harbored greater abundances of Gammaproteobacteria and Planctomycetes, and those from Florida had more Deltaproteobacteria and Firmicutes. Marine beaches had significantly different phylogenetic community structures (P ≤ 0.018), but freshwater and Florida beaches showed fewer within-region phylogenetic differences. Furthermore, regionally distinct patterns in taxonomic variation were observed in backshore sands, which had communities distinct from those in nearshore sands (P < 0.001). Sample depth minimally influenced the community composition. The results of this study reveal distinct bacterial community structures in sand on a broad geographic scale but moderate regional similarity and suggest that local variation is primarily related to the distance from the shoreline. This study offers a novel comparison of the bacterial communities in freshwater and marine beach sands and provides an important basis for future comparisons and analyses to elucidate factors affecting microbial ecology in this underexplored environment. IMPORTANCE This study presents a large-scale geographic characterization of the bacterial communities present in beach

  14. Similarities in the Spatial Pattern of the Surface Flux Response to Present-Day Greenhouse Gases and Aerosols

    NASA Astrophysics Data System (ADS)

    Persad, G.; Ming, Y.; Ramaswamy, V.

    2014-12-01

    Recent studies suggest that present-day greenhouse gases (GHGs) and aerosols can produce remarkably similar patterns of climate response in fully coupled general circulation model (GCM) simulations, despite having significantly different spatial patterns of top-of-atmosphere (TOA) forcing. However, there is little understanding of the mechanisms of ocean-atmosphere interaction that could lead to the response pattern formation. Surface flux perturbations are a crucial pathway by which TOA forcing is communicated to the ocean, and may be a vital link in explaining the spatial similarities in the fully coupled responses to disparate TOA forcing patterns—a phenomenon with implications for detection and attribution, as well as the climate sensitivity to different forcers. We analyze the surface energy budget response to present-day aerosols versus GHGs in single forcing, fixed SST, atmospheric GCM experiments to identify mechanisms for response pattern formation via surface flux perturbations. We find that, although the TOA forcing spatial patterns of GHGs and aerosols are largely uncorrelated, their surface radiative and heat flux patterns are significantly anti-correlated. Furthermore, this anti-correlation is largely explained by similar (but sign-reversed) spatial patterns of surface latent and sensible heat flux response to the two forcers, particularly over the winter-hemisphere extratropical oceans. These are, in turn, driven by spatially similar perturbations in surface winds from changes in mean tropical and midlatitude circulation. These results suggest that the mean atmospheric circulation, which has many anti-symmetric responses to GHG and aerosol forcings, is an efficient homogenizer of spatial patterns in the surface heat flux response to heterogeneous TOA forcings, creating an atmosphere-only pathway for similarities in the fully coupled response.

  15. Aging in the natural world: comparative data reveal similar mortality patterns across primates.

    PubMed

    Bronikowski, Anne M; Altmann, Jeanne; Brockman, Diane K; Cords, Marina; Fedigan, Linda M; Pusey, Anne; Stoinski, Tara; Morris, William F; Strier, Karen B; Alberts, Susan C

    2011-03-11

    Human senescence patterns-late onset of mortality increase, slow mortality acceleration, and exceptional longevity-are often described as unique in the animal world. Using an individual-based data set from longitudinal studies of wild populations of seven primate species, we show that contrary to assumptions of human uniqueness, human senescence falls within the primate continuum of aging; the tendency for males to have shorter life spans and higher age-specific mortality than females throughout much of adulthood is a common feature in many, but not all, primates; and the aging profiles of primate species do not reflect phylogenetic position. These findings suggest that mortality patterns in primates are shaped by local selective forces rather than phylogenetic history.

  16. Similarities and Differences in Patterns and Geolocation of SSH Attack Data

    DTIC Science & Technology

    2015-09-01

    DIFFERENCES IN PATTERNS AND GEOLOCATION OF SSH ATTACK DATA by Jeffry P. Macy II September 2015 Thesis Advisor: Neil C. Rowe Second...collection of information is estimated to average 1 hour per response, including the time for reviewing instruction, searching existing data sources...gathering and maintaining the data needed, and completing and reviewing the collection of information. Send comments regarding this burden estimate or

  17. Contrasting global genetic patterns in two biologically similar, widespread and invasive Ciona species (Tunicata, Ascidiacea)

    PubMed Central

    Bouchemousse, Sarah; Bishop, John D. D.; Viard, Frédérique

    2016-01-01

    Human-mediated dispersal interplays with natural processes and complicates understanding of the biogeographical history of species. This is exemplified by two invasive tunicates, Ciona robusta (formerly Ciona intestinalis type A) and C. intestinalis (formerly Ciona intestinalis type B), globally distributed and sympatric in Europe. By gathering new mitochondrial sequences that were merged with published datasets, we analysed genetic patterns in different regions, with a focus on 1) their sympatric range and 2) allopatric populations in N and S America and southern Europe. In the sympatric range, the two species display contrasting genetic diversity patterns, with low polymorphism in C. robusta supporting the prevalent view of its recent introduction. In the E Pacific, several genetic traits support the non-native status of C. robusta. However, in the NE Pacific, this appraisal requires a complex scenario of introduction and should be further examined supported by extensive sampling efforts in the NW Pacific (putative native range). For C. intestinalis, Bayesian analysis suggested a natural amphi-North Atlantic distribution, casting doubt on its non-native status in the NW Atlantic. This study shows that both natural and human-mediated dispersal have influenced genetic patterns at broad scales; this interaction lessens our ability to confidently ascertain native vs. non-native status of populations, particularly of those species that are globally distributed. PMID:27137892

  18. Using Similarities and Differences: A Meta-Analysis of Its Effects and Emergent Patterns

    ERIC Educational Resources Information Center

    Apthorp, Helen S.; Igel, Charles; Dean, Ceri

    2012-01-01

    The purpose of the study was to update previous meta-analytic findings on the effectiveness of using similarities and differences as an instructional strategy. The strategy includes facilitating student comparison, classification, use of analogies, and use of metaphors. Previously, Marzano, Pickering, and Pollock reported a mean effect size of…

  19. Additives

    NASA Technical Reports Server (NTRS)

    Smalheer, C. V.

    1973-01-01

    The chemistry of lubricant additives is discussed to show what the additives are chemically and what functions they perform in the lubrication of various kinds of equipment. Current theories regarding the mode of action of lubricant additives are presented. The additive groups discussed include the following: (1) detergents and dispersants, (2) corrosion inhibitors, (3) antioxidants, (4) viscosity index improvers, (5) pour point depressants, and (6) antifouling agents.

  20. Similar patterns of neural activity predict memory function during encoding and retrieval.

    PubMed

    Kragel, James E; Ezzyat, Youssef; Sperling, Michael R; Gorniak, Richard; Worrell, Gregory A; Berry, Brent M; Inman, Cory; Lin, Jui-Jui; Davis, Kathryn A; Das, Sandhitsu R; Stein, Joel M; Jobst, Barbara C; Zaghloul, Kareem A; Sheth, Sameer A; Rizzuto, Daniel S; Kahana, Michael J

    2017-04-01

    Neural networks that span the medial temporal lobe (MTL), prefrontal cortex, and posterior cortical regions are essential to episodic memory function in humans. Encoding and retrieval are supported by the engagement of both distinct neural pathways across the cortex and common structures within the medial temporal lobes. However, the degree to which memory performance can be determined by neural processing that is common to encoding and retrieval remains to be determined. To identify neural signatures of successful memory function, we administered a delayed free-recall task to 187 neurosurgical patients implanted with subdural or intraparenchymal depth electrodes. We developed multivariate classifiers to identify patterns of spectral power across the brain that independently predicted successful episodic encoding and retrieval. During encoding and retrieval, patterns of increased high frequency activity in prefrontal, MTL, and inferior parietal cortices, accompanied by widespread decreases in low frequency power across the brain predicted successful memory function. Using a cross-decoding approach, we demonstrate the ability to predict memory function across distinct phases of the free-recall task. Furthermore, we demonstrate that classifiers that combine information from both encoding and retrieval states can outperform task-independent models. These findings suggest that the engagement of a core memory network during either encoding or retrieval shapes the ability to remember the past, despite distinct neural interactions that facilitate encoding and retrieval.

  1. Bison and bovine rectoanal junctions exhibit similar cellular architecture and Escherichia coli O157 adherence patterns

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Escherichia coli O157 (O157) is frequently isolated from bison retail meat, a fact that is important given that bison meat has also been implicated in an O157-multistate outbreak. In addition, O157 has also been isolated from bison feces at slaughter and on farms. Cattle are well documented as O15...

  2. Generalized method for sorting Shack-Hartmann spot patterns using local similarity

    SciTech Connect

    Smith, Daniel G.; Greivenkamp, John E

    2008-09-01

    The sensitivity and dynamic range of a Shack-Hartmann wavefront sensor is enhanced when the spots produced by the lenslet array are allowed to shift more than one lenslet radius from their on-axis positions. However, this presents the problem of accurately and robustly associating the spots with their respective subapertures. This paper describes a method for sorting spots that takes advantage of the local spot position distortions to unwrap the spot pattern. The described algorithm is both simple and robust and also applicable to any lenslet array geometry that can be described as a two-dimensional lattice, including hexagonal arrays, which are shown here to be more efficient than square arrays.

  3. Aging in the Natural World: Comparative Data Reveal Similar Mortality Patterns Across Primates

    PubMed Central

    Bronikowski, Anne M.; Altmann, Jeanne; Brockman, Diane K.; Cords, Marina; Fedigan, Linda M.; Pusey, Anne; Stoinski, Tara; Morris, William F.; Strier, Karen B.; Alberts, Susan C.

    2012-01-01

    Human senescence patterns—late onset of mortality increase, slow mortality acceleration, and exceptional longevity—are often described as unique in the animal world. Using an individual-based data set from longitudinal studies of wild populations of seven primate species, we show that contrary to assumptions of human uniqueness, human senescence falls within the primate continuum of aging; the tendency for males to have shorter life spans and higher age-specific mortality than females throughout much of adulthood is a common feature in many, but not all, primates; and the aging profiles of primate species do not reflect phylogenetic position. These findings suggest that mortality patterns in primates are shaped by local selective forces rather than phylogenetic history. PMID:21393544

  4. Unbounded growth patterns of reproducing, competing polymers—similarities to biological evolution

    NASA Astrophysics Data System (ADS)

    Gregor Worst, Emanuel; Zimmer, Philipp; Wollrab, Eva; Kruse, Karsten; Ott, Albrecht

    2016-10-01

    Since the origin of life the interplay between reproduction, variation, and selection has been driving the emergence of new species. The evolution of the Earth’s biosphere appears to innovate unceasingly instead of coming to a stall. Here, we introduce a model system of linear molecules where new polymers appear by spontaneous ligation. The polymers proliferate following a template-based mechanism. Our combined experimental and theoretical study shows that for sufficiently rapid autocatalysis the reproduction process selects particular lengths—while ever longer polymers emerge. We suggest similarities to biological evolution.

  5. Single molecule PCR reveals similar patterns of non-homologous DSB repair in tobacco and Arabidopsis.

    PubMed

    Lloyd, Andrew H; Wang, Dong; Timmis, Jeremy N

    2012-01-01

    DNA double strand breaks (DSBs) occur constantly in eukaryotes. These potentially lethal DNA lesions are repaired efficiently by two major DSB repair pathways: homologous recombination and non-homologous end joining (NHEJ). We investigated NHEJ in Arabidopsis thaliana and tobacco (Nicotiana tabacum) by introducing DNA double-strand breaks through inducible expression of I-SceI, followed by amplification of individual repair junction sequences by single-molecule PCR. Using this process over 300 NHEJ repair junctions were analysed in each species. In contrast to previously published variation in DSB repair between Arabidopsis and tobacco, the two species displayed similar DSB repair profiles in our experiments. The majority of repair events resulted in no loss of sequence and small (1-20 bp) deletions occurred at a minority (25-45%) of repair junctions. Approximately ~1.5% of the observed repair events contained larger deletions (>20 bp) and a similar percentage contained insertions. Strikingly, insertion events in tobacco were associated with large genomic deletions at the site of the DSB that resulted in increased micro-homology at the sequence junctions suggesting the involvement of a non-classical NHEJ repair pathway. The generation of DSBs through inducible expression of I-SceI, in combination with single molecule PCR, provides an effective and efficient method for analysis of individual repair junctions and will prove a useful tool in the analysis of NHEJ.

  6. Patterns of similarity and difference between the vocabularies of psychology and other subjects.

    PubMed

    Benjafield, John G

    2014-02-01

    The vocabulary of Anglophone psychology is shared with many other subjects. Previous research using the Oxford English Dictionary has shown that the subjects having the most words in common with psychology are biology, chemistry, computing, electricity, law, linguistics, mathematics, medicine, music, pathology, philosophy, and physics. The present study presents a database of the vocabularies of these 12 subjects that is similar to one previously constructed for psychology, enabling the histories of the vocabularies of these subjects to be compared with each other as well as with psychology. All subjects have a majority of word senses that are metaphorical. However, psychology is not among the most metaphorical of subjects, a distinction belonging to computing, linguistics, and mathematics. Indeed, the history of other subjects shows an increasing tendency to recycle old words and give them new, metaphorical meanings. The history of psychology shows an increasing tendency to invent new words rather than metaphorical senses of existing words. These results were discussed in terms of the degree to which psychology's vocabulary remains unsettled in comparison with other subjects. The possibility was raised that the vocabulary of psychology is in a state similar to that of chemistry prior to Lavoisier.

  7. Combining 1-D components to extract pattern information: It is about more than component similarity

    PubMed Central

    Quaia, Christian; Optican, Lance M.; Cumming, Bruce G.

    2017-01-01

    At least under some conditions, plaid stimuli are processed by combining information first extracted in orientation and scale-selective channels. The rules that govern this combination across channels are only partially understood. Although the available data suggests that only components having similar spatial frequency and contrast are combined, the extent to which this holds has not been firmly established. To address this question, we measured, in human subjects, the short-latency reflexive vergence eye movements induced by stereo plaids in which spatial frequency and contrast of the components are independently varied. We found that, although similarity in component spatial frequency and contrast matter, they interact in a nonseparable way. One way in which this relationship might arise is if the internal estimate of contrast is not a faithful representation of stimulus contrast but is instead spatial frequency–dependent (with higher spatial frequencies being boosted). We propose that such weighting might have been put in place by a mechanism that, in an effort of achieve contrast constancy and/or coding efficiency, regulates the gain of detectors in early visual cortex to equalize their long-term average response to natural images. PMID:28355633

  8. Epidemiologic import of tuberculosis cases whose isolates have similar but not identical IS6110 restriction fragment length polymorphism patterns.

    PubMed

    Cave, M D; Yang, Z H; Stefanova, R; Fomukong, N; Ijaz, K; Bates, J; Eisenach, K D

    2005-03-01

    Isolates of Mycobacterium tuberculosis from patients with epidemiologic links frequently demonstrate identical IS6110 restriction fragment length polymorphism (RFLP) patterns (i.e., RFLP clustering) because they are infected with the same strain. Uncertainty arises with isolates that differ from one another by a few IS6110 hybridizing bands. During the period from 1 January 1996 to 31 December 1999, isolates from 585 tuberculosis (TB) cases were analyzed by RFLP, representing 98.2% of the 596 culture-positive TB cases reported in Arkansas during the study period. Of the 585 cases for which RFLP was available, 419 (71.6%) had an RFLP pattern with more than five copies of IS6110. Of the total 74 clusters, 48 comprised isolates with more than five copies of IS6110 and included 164 cases. Sixty-nine isolates with more than five copies of IS6110 comprising 16 clusters and 60 unique isolates were found to be similar to at least 1 other isolate (differing from it by one or two hybridizing bands). Among the 129 cases whose isolates were similar to other clustered or unique isolates, 16 cases were discovered with epidemiologic links: 14 (15.2%) were among the 92 cases with IS6110 RFLP patterns similar to those in clusters, and 2 (5.2%) were among the 37 unique cases that were similar to another unique case. The isolates from the epidemiologically linked patients shared common spoligotypes; all except one case shared common polymorphic GC-rich sequence (PGRS) patterns. Of the 129 patients whose isolates differed from another by one or two hybridizing IS6110 bands, 101 (78.3%) shared common spoligotypes and 87 (67.4%) shared common PGRS RFLP patterns.

  9. Intensity normalization of additive and multiplicative spatially multiplexed patterns with n encoded phases

    NASA Astrophysics Data System (ADS)

    Juarez-Salazar, Rigoberto; Robledo-Sanchez, Carlos; Guerrero-Sanchez, Fermin; Barcelata-Pinzon, Antonio; Gonzalez-Garcia, Jorge; Santiago-Alvarado, Agustin

    2016-02-01

    An efficient, robust and user-free intensity normalization method for patterns with n frequency-multiplexed phases of both additive and multiplicative types is proposed. For this, the parameter estimation approach by using the least-squares method is applied. The theoretical principles are given and the good performance of the proposal is verified by computer simulation and experimental results. Because the proposed method has good features such as robustness, simplicity, fast and user-free execution, it could be implemented in a wide variety of applications. This contribution motivates future generalization in both phase demodulation algorithms and experimental setups to exploit the benefits of additive/multiplicative patterns with multiple phases.

  10. Patterns of cuticular hydrocarbon variation and genetic similarity between natural populations of Amblyomma cajennense (Acari: Ixodidae).

    PubMed

    Estrada-Peña, A; Guglielmone, A A; Mangold, A J; Castellá, J

    1993-10-01

    Gas chromatography has been used to analyze the variation in cuticular hydrocarbon patterns between several populations of Amblyomma cajennense. 88 compounds were detected and these could be divided into 17 groups of hydrocarbons. Heterozygosis in the populations ranges from 0% to 25.84%. Isomers for pentacosane, heptacosane and nonatriacontane are the most variable, with 13, 10 and 11 variants, respectively. Nei's genetic identity and genetic distance show that populations may be considered as regional variants of only one species: the results do not indicate the presence of sibling species. However, a relatively high genetic distance has been observed between several Cuban and continental populations, suggesting a long reproductive isolation. Gas chromatography of cuticular hydrocarbons is a good alternative to isozyme analysis for population studies, when collecting conditions do not allow the use of live ticks and only alcohol-preserved collections are available. The high number of compounds available for genetic studies will provide excellent markers for evaluating the extent of gene flow and migration of tick species.

  11. Stable Patterns of CENH3 Occupancy Through Maize Lineages Containing Genetically Similar Centromeres

    PubMed Central

    Gent, Jonathan I.; Wang, Kai; Jiang, Jiming; Dawe, R. Kelly

    2015-01-01

    While the approximate chromosomal position of centromeres has been identified in many species, little is known about the dynamics and diversity of centromere positions within species. Multiple lines of evidence indicate that DNA sequence has little or no impact in specifying centromeres in maize and in most multicellular organisms. Given that epigenetically defined boundaries are expected to be dynamic, we hypothesized that centromere positions would change rapidly over time, which would result in a diversity of centromere positions in isolated populations. To test this hypothesis, we used CENP-A/cenH3 (CENH3 in maize) chromatin immunoprecipitation to define centromeres in breeding pedigrees that included the B73 inbred as a common parent. While we found a diversity of CENH3 profiles for centromeres with divergent sequences that were not inherited from B73, the CENH3 profiles from centromeres that were inherited from B73 were indistinguishable from each other. We propose that specific genetic elements in centromeric regions favor or inhibit CENH3 accumulation, leading to reproducible patterns of CENH3 occupancy. These data also indicate that dramatic shifts in centromere position normally originate from accumulated or large-scale genetic changes rather than from epigenetic positional drift. PMID:26063660

  12. Similar symptom patterns in gastroesophageal reflux patients with and without hiatal hernia.

    PubMed

    Antoniou, S A; Koch, O O; Antoniou, G A; Asche, K U; Kaindlstorfer, A; Granderath, F A; Pointner, R

    2013-07-01

    Gastroesophageal reflux disease is a common clinical entity in Western societies. Its association with hiatal hernia has been well documented; however, the comparative clinical profile of patients in the presence or absence of hiatal hernia remains mostly unknown. The aim of the present study was to delineate and compare symptom, impedance, and manometric patterns of patients with and without hiatal hernia. A cumulative number of 120 patients with reflux disease were enrolled in the study. Quality of life score, demographic, symptom, manometric, and impedance data were prospectively collected. Data comparison was undertaken between patients with and without hiatal hernia. A P-value < 0.05 was considered statistically significant. Patients with hiatal hernia tended to be older than patients without hernia (52.3 vs. 48.6 years, P < 0.05), whereas quality of life scores were slightly better for the former (97.0 vs. 88.2, P= 0.005). Regurgitation occurred more frequently in patients without hiatal hernia (78.3% vs. 93.9%, P < 0.05). Otherwise, no differences were found with regard to esophageal and extraesophageal symptoms. However, lower esophageal sphincter pressures (7.7 vs. 10.0 mmHg, P= 0.007) and more frequent reflux episodes (upright, 170 vs. 134, P= 0.01; supine, 41 vs. 24, P < 0.03) were documented for patients with hiatal hernia on manometric and impedance studies. Distinct functional characteristics in patients with and without hiatal hernia may suggest a tailored therapeutic management for these diverse patient groups.

  13. Temporal patterns of dissolved organic matter biodegradability are similar across three rivers of varying size

    NASA Astrophysics Data System (ADS)

    Coble, Ashley A.; Marcarelli, Amy M.; Kane, Evan S.; Toczydlowski, David; Stottlemyer, Robert

    2016-06-01

    Dissolved organic matter (DOM) composition may be an important determinant of its fate in freshwaters, but little is known about temporal variability in DOM composition and the biodegradability of DOM in northern temperate watersheds. We measured biodegradable dissolved organic carbon (BDOC) via incubation assays and DOM composition using optical indices on 11 dates in three Lake Superior tributaries. Percent BDOC (%BDOC) and BDOC concentrations were seasonally synchronous across these watersheds, despite that they vary in size by orders of magnitude (1.7 to 3400 km2). Relative to %BDOC, BDOC concentrations were more tightly constrained among sites on any given date. BDOC also varied within seasons; for example, %BDOC on two different dates in winter were among the highest (29% and 54%) and lowest (0%) values observed for each site (overall %BDOC range: 0 to 72%). DOM composition varied the most among tributaries during a summer storm event when BDOC (both as percent and concentration) was elevated but was remarkably similar among tributaries during fall, spring, and winter. Multivariate models identified humic-like and tryptophan-like fluorophores as predictors of %BDOC, but DOM composition only described 21% of the overall variation in %BDOC. Collectively, these three rivers exported ~18 Gg C yr-1 as DOC and ~2 Gg C yr-1 as BDOC, which corresponded to 9 to 17% of annual DOC exported in biodegradable form. Our results suggest much of the C exported from these northern temperate watersheds may be biodegradable within 28 days and that large pulses of labile DOM can be exported during storm events and spring snowmelt.

  14. Pattern of intake of food additives associated with hyperactivity in Irish children and teenagers.

    PubMed

    Connolly, A; Hearty, A; Nugent, A; McKevitt, A; Boylan, E; Flynn, A; Gibney, M J

    2010-04-01

    A double-blind randomized intervention study has previously shown that a significant relationship exists between the consumption of various mixes of seven target additives by children and the onset of hyperactive behaviour. The present study set out to ascertain the pattern of intake of two mixes (A and B) of these seven target additives in Irish children and teenagers using the Irish national food consumption databases for children (n = 594) and teenagers (n = 441) and the National Food Ingredient Database. The majority of additive-containing foods consumed by both the children and teenagers contained one of the target additives. No food consumed by either the children or teenagers contained all seven of the target food additives. For each additive intake, estimates for every individual were made assuming that the additive was present at the maximum legal permitted level in those foods identified as containing it. For both groups, mean intakes of the food additives among consumers only were far below the doses used in the previous study on hyperactivity. Intakes at the 97.5th percentile of all food colours fell below the doses used in Mix B, while intakes for four of the six food colours were also below the doses used in Mix A. However, in the case of the preservative sodium benzoate, it exceeded the previously used dose in both children and teenagers. No child or teenager achieved the overall intakes used in the study linking food additives with hyperactivity.

  15. Myelomatous plasma cells display an aberrant gene expression pattern similar to that observed in normal memory B cells

    PubMed Central

    Báez, Alicia; Piruat, José I; Caballero-Velázquez, Teresa; Sánchez-Abarca, Luís I; Álvarez-Laderas, Isabel; Barbado, M Victoria; García-Guerrero, Estefanía; Millán-Uclés, África; Martín-Sánchez, Jesús; Medrano, Mayte; Pérez-Simón, José Antonio

    2015-01-01

    Memory B cells (MBCs) remain in a quiescent state for years, expressing pro-survival and anti-apoptotic factors while repressing cell proliferation and activation genes. During their differentiation into plasma cells (PCs), their expression pattern is reversed, with a higher expression of genes related to cell proliferation and activation, and a lower expression of pro-survival genes. To determine whether myelomatous PCs (mPCs) share characteristics with normal PCs and MBCs and to identify genes involved in the pathophysiology of multiple myeloma (MM), we compared gene expression patterns in these three cell sub-types. We observed that mPCs had features intermediate between those of MBCs and normal PCs, and identified 3455 genes differentially expressed in mPCs relative to normal PCs but with a similar expression pattern to that in MBCs. Most of these genes are involved in cell death and survival, cell growth and proliferation and protein synthesis. According to our findings, mPCs have a gene expression pattern closer to a MBC than a PC with a high expression of genes involved in cell survival. These genes should be physiologically inactivated in the transit from MBC to PC, but remain overexpressed in mPCs and thus may play a role in the pathophysiology of the disease. PMID:25628947

  16. Chronic lung injury risk estimates for urban areas having ozone patterns similar to those in the Northeast

    SciTech Connect

    Absil, M.; Narducci, P.; Whitfield, R.; Richmond, H.M.

    1991-12-31

    This paper describes the approach and result of an assessment of health risks associated with long-term exposure to ozone. The health endpoint of interest is the probability of formation of mild lesions in the centriacinar region of the lung among children living in New York City. The risk model incorporates an exposure model and a health model. The exposure model is preliminary results of the probabilistic NAAQS Exposure Model (P-NEM) for ozone, and the health model is the judgments of active researchers about the likelihood of formation of ozone-induced lesions in the human lung. Children and New York City were chosen as the population and city of interest because it is believed that children are more sensitive to ozone than any other group of people, and New York City is more representative of other urban areas than Los Angeles, the other city of which P-NEM exposure results are available. Risk results are presented for ten exposure distributions generated by P-NEM, two air quality scenarios (``as-is`` and ``attainment``), and two exposure periods (1 and 10 ozone seasons). The results vary across experts, are not very sensitive to variations in P-NEM exposure distributions, are lower for attainment conditions than as-is conditions, and are lower for 1 season of exposure than 10 seasons. Although these results are specific to children living in areas having exposure patterns similar to those found in the Northeast, they are fairly representative of results for outdoor workers in the Northeast and Southern California and for children in Southern California. The reason for this is that many experts believe that children and outdoor workers respond in a similar fashion to the given exposure patterns, or that exposure patterns in the Northeast and Southern California are similar. Some experts held both of these beliefs. These results should help policymakers evaluate alternative national ambient air quality standards for ozone. 4 refs., 9 figs., 3 tabs.

  17. Chronic lung injury risk estimates for urban areas having ozone patterns similar to those in the Northeast

    SciTech Connect

    Absil, M.; Narducci, P.; Whitfield, R. ); Richmond, H.M. . Office of Air Quality Planning and Standards)

    1991-01-01

    This paper describes the approach and result of an assessment of health risks associated with long-term exposure to ozone. The health endpoint of interest is the probability of formation of mild lesions in the centriacinar region of the lung among children living in New York City. The risk model incorporates an exposure model and a health model. The exposure model is preliminary results of the probabilistic NAAQS Exposure Model (P-NEM) for ozone, and the health model is the judgments of active researchers about the likelihood of formation of ozone-induced lesions in the human lung. Children and New York City were chosen as the population and city of interest because it is believed that children are more sensitive to ozone than any other group of people, and New York City is more representative of other urban areas than Los Angeles, the other city of which P-NEM exposure results are available. Risk results are presented for ten exposure distributions generated by P-NEM, two air quality scenarios ( as-is'' and attainment''), and two exposure periods (1 and 10 ozone seasons). The results vary across experts, are not very sensitive to variations in P-NEM exposure distributions, are lower for attainment conditions than as-is conditions, and are lower for 1 season of exposure than 10 seasons. Although these results are specific to children living in areas having exposure patterns similar to those found in the Northeast, they are fairly representative of results for outdoor workers in the Northeast and Southern California and for children in Southern California. The reason for this is that many experts believe that children and outdoor workers respond in a similar fashion to the given exposure patterns, or that exposure patterns in the Northeast and Southern California are similar. Some experts held both of these beliefs. These results should help policymakers evaluate alternative national ambient air quality standards for ozone. 4 refs., 9 figs., 3 tabs.

  18. 3D similarity-dissimilarity plot for high dimensional data visualization in the context of biomedical pattern classification.

    PubMed

    Arif, Muhammad; Basalamah, Saleh

    2013-06-01

    In real life biomedical classification applications, it is difficult to visualize the feature space due to high dimensionality of the feature space. In this paper, we have proposed 3D similarity-dissimilarity plot to project the high dimensional space to a three dimensional space in which important information about the feature space can be extracted in the context of pattern classification. In this plot it is possible to visualize good data points (data points near to their own class as compared to other classes) and bad data points (data points far away from their own class) and outlier points (data points away from both their own class and other classes). Hence separation of classes can easily be visualized. Density of the data points near each other can provide some useful information about the compactness of the clusters within certain class. Moreover, an index called percentage of data points above the similarity-dissimilarity line (PAS) is proposed which is the fraction of data points above the similarity-dissimilarity line. Several synthetic and real life biomedical datasets are used to show the effectiveness of the proposed 3D similarity-dissimilarity plot.

  19. Mosaic activity patterns and their relation to perceptual similarity: open discussions on the molecular basis and circuitry of odor recognition.

    PubMed

    Locatelli, Fernando F; Rela, Lorena

    2014-12-01

    Enormous advances have been made in the recent years in regard to the mechanisms and neural circuits by which odors are sensed and perceived. Part of this understanding has been gained from parallel studies in insects and rodents that show striking similarity in the mechanisms they use to sense, encode, and perceive odors. In this review, we provide a short introduction to the functioning of olfactory systems from transduction of odorant stimuli into electrical signals in sensory neurons to the anatomical and functional organization of the networks involved in neural representation of odors in the central nervous system. We make emphasis on the functional and anatomical architecture of the first synaptic relay of the olfactory circuit, the olfactory bulb in vertebrates and the antennal lobe in insects. We discuss how the exquisite and conserved architecture of this structure is established and how different odors are encoded in mosaic activity patterns. Finally, we discuss the validity of methods used to compare activation patterns in relation to perceptual similarity.

  20. Reinstatement of individual past events revealed by the similarity of distributed activation patterns during encoding and retrieval.

    PubMed

    Wing, Erik A; Ritchey, Maureen; Cabeza, Roberto

    2015-04-01

    Neurobiological memory models assume memory traces are stored in neocortex, with pointers in the hippocampus, and are then reactivated during retrieval, yielding the experience of remembering. Whereas most prior neuroimaging studies on reactivation have focused on the reactivation of sets or categories of items, the current study sought to identify cortical patterns pertaining to memory for individual scenes. During encoding, participants viewed pictures of scenes paired with matching labels (e.g., "barn," "tunnel"), and, during retrieval, they recalled the scenes in response to the labels and rated the quality of their visual memories. Using representational similarity analyses, we interrogated the similarity between activation patterns during encoding and retrieval both at the item level (individual scenes) and the set level (all scenes). The study yielded four main findings. First, in occipitotemporal cortex, memory success increased with encoding-retrieval similarity (ERS) at the item level but not at the set level, indicating the reactivation of individual scenes. Second, in ventrolateral pFC, memory increased with ERS for both item and set levels, indicating the recapitulation of memory processes that benefit encoding and retrieval of all scenes. Third, in retrosplenial/posterior cingulate cortex, ERS was sensitive to individual scene information irrespective of memory success, suggesting automatic activation of scene contexts. Finally, consistent with neurobiological models, hippocampal activity during encoding predicted the subsequent reactivation of individual items. These findings show the promise of studying memory with greater specificity by isolating individual mnemonic representations and determining their relationship to factors like the detail with which past events are remembered.

  1. Spectral Similarity Assessment Based on a Spectrum Reflectance-Absorption Index and Simplified Curve Patterns for Hyperspectral Remote Sensing.

    PubMed

    Ma, Dan; Liu, Jun; Huang, Junyi; Li, Huali; Liu, Ping; Chen, Huijuan; Qian, Jing

    2016-01-26

    Hyperspectral images possess properties such as rich spectral information, narrow bandwidth, and large numbers of bands. Finding effective methods to retrieve land features from an image by using similarity assessment indices with specific spectral characteristics is an important research question. This paper reports a novel hyperspectral image similarity assessment index based on spectral curve patterns and a reflection-absorption index. First, some spectral reflection-absorption features are extracted to restrict the subsequent curve simplification. Then, the improved Douglas-Peucker algorithm is employed to simplify all spectral curves without setting the thresholds. Finally, the simplified curves with the feature points are matched, and the similarities among the spectral curves are calculated using the matched points. The Airborne Visible Infrared Imaging Spectrometer (AVIRIS) and Reflective Optics System Imaging Spectrometer (ROSIS) hyperspectral image datasets are then selected to test the effect of the proposed index. The practical experiments indicate that the proposed index can achieve higher precision and fewer points than the traditional spectral information divergence and spectral angle match.

  2. Spectral Similarity Assessment Based on a Spectrum Reflectance-Absorption Index and Simplified Curve Patterns for Hyperspectral Remote Sensing

    PubMed Central

    Ma, Dan; Liu, Jun; Huang, Junyi; Li, Huali; Liu, Ping; Chen, Huijuan; Qian, Jing

    2016-01-01

    Hyperspectral images possess properties such as rich spectral information, narrow bandwidth, and large numbers of bands. Finding effective methods to retrieve land features from an image by using similarity assessment indices with specific spectral characteristics is an important research question. This paper reports a novel hyperspectral image similarity assessment index based on spectral curve patterns and a reflection-absorption index. First, some spectral reflection-absorption features are extracted to restrict the subsequent curve simplification. Then, the improved Douglas-Peucker algorithm is employed to simplify all spectral curves without setting the thresholds. Finally, the simplified curves with the feature points are matched, and the similarities among the spectral curves are calculated using the matched points. The Airborne Visible Infrared Imaging Spectrometer (AVIRIS) and Reflective Optics System Imaging Spectrometer (ROSIS) hyperspectral image datasets are then selected to test the effect of the proposed index. The practical experiments indicate that the proposed index can achieve higher precision and fewer points than the traditional spectral information divergence and spectral angle match. PMID:26821030

  3. Endothelial pattern formation in hybrid constructs of additive manufactured porous rigid scaffolds and cell-laden hydrogels for orthopedic applications.

    PubMed

    Shanjani, Yaser; Kang, Yunqing; Zarnescu, Livia; Ellerbee Bowden, Audrey K; Koh, Jeong-Tae; Ker, Dai Fei Elmer; Yang, Yunzhi

    2017-01-01

    Vascularization of tissue engineering constructs (TECs) in vitro is of critical importance for ensuring effective and satisfactory clinical outcomes upon implantation of TECs. Biomechanical properties of TECs have remarkable influence on the in vitro vascularization of TECs. This work utilized in vitro experiments and finite element analysis to investigate endothelial patterns in hybrid constructs of soft collagen gels and rigid macroporous poly(ε-caprolactone)-β-tricalcium phosphate (PCL-β-TCP) scaffold seeded/embedded with human umbilical vein endothelial cells (HUVECs) for bone tissue engineering applications. We first fabricated and characterized well-defined porous PCL-β-TCP scaffolds with identical pore size (500µm) but different strut sizes (200 and 400µm) using additive manufacturing (AM) technology, and then assessed the HUVEC׳s proliferation and morphogenesis within collagen, PCL-β-TCP scaffold, and the collagen-scaffold hybrid construct. Results showed that, in the hybrid construct, the cell population in the collagen component dropped by day 7 but then increased by day 14. Also, cells migrated onto the struts of the scaffold component, proliferated over time, and formed networks on the thinner struts (i.e., 200µm). Also, the thinner struts resulted in formation of long linear cellular cords structures within the pores. Finite element simulation demonstrated principal stress patterns similar to the observed cell-network pattern. It is probable that the scaffold component modulated patterns of principal stresses in the collagen component as biomechanical cues for reorganization of cell network patterns. Also, the scaffold component significantly improved the mechanical integrity of hydrogel component in the hybrid construct for weight-bearing applications. These results have collectively indicated that the manipulation of micro-architecture of scaffold could be an effective means to further regulate and guide desired cellular response in hybrid

  4. Similarities and gradients in growth unit branching patterns during ontogeny in "Fuji" apple trees: a stochastic approach.

    PubMed

    Renton, Michael; Guédon, Yann; Godin, Christophe; Costes, Evelyne

    2006-01-01

    This study aims to explore and model the changes in growth unit (GU) branching patterns during tree ontogeny. The question was addressed in apple trees cv. "Fuji", by analysing the relative impact of GU length and within-tree position. The development of two 6-year-old trees was recorded over 6 years. The fate of axillary buds along each GU was represented as a sequence of symbols corresponding to five types of lateral growth: latent buds, short, medium, long, and floral lateral GUs. Based on an exploratory analysis of data and a priori hypotheses, a hidden semi-Markov chain was estimated from all of these GU sequences. This model was composed of six transient states representing successive branching zones along the GUs. The accuracy of this global model was a posteriori assessed by fitting the characteristic distributions computed from model parameters to the corresponding empirical characteristic distributions extracted from the observed sequences. The observed sequences were then grouped hierarchically according to the GU length, year of growth, and branching order. Comparing model parameters between these sub-groups revealed similarities between GUs. These similarities were based on particular branching zones whose composition and relative position within the GUs remained invariant across the subgroups: the latent zones, floral zone, and short-lateral zone. The probability of occurrence of the floral zone varied with the year, showing the alternate fruiting of "Fuji". It is shown that, during tree ontogeny, as GU length decreases, branching patterns tend to progressively simplify due to the disappearance of the most central zones and a progressive reduction in the length of the floral zone.

  5. Detection of Aeromonas hydrophila in Liquid Media by Volatile Production Similarity Patterns, Using a FF-2A Electronic Nose

    PubMed Central

    Fujioka, Kouki; Arakawa, Eiji; Kita, Jun-ichi; Aoyama, Yoshihiro; Manome, Yoshinobu; Ikeda, Keiichi; Yamamoto, Kenji

    2013-01-01

    A technique for rapid detection of pathogenic microorganisms is essential for the diagnosis of associated infections and for food safety analysis. Aeromonas hydrophila is one such food contaminant. Several methods for rapid detection of this pathogen have been developed; these include multiplex polymerase chain reaction assays and the colony overlay procedure for peptidases. However, these conventional methods can only be used to detect the microorganisms at high accuracy after symptomatic onset of the disease. Therefore, in the future, simple pre-screening methods may be useful for preventing food poisoning and disease. In this paper, we present a novel system for the rapid detection of the microorganism A. hydrophila in cultured media (in <2 h), with the use of an electronic nose (FF-2A). With this electronic nose, we detected the changes of volatile patterns produced by A. hydrophila after 30 min culture. Our calculations revealed that the increased volatiles were similar to the odours of organic acids and esters. In future, distinctive volatile production patterns of microorganisms identified with the electronic nose may have the potential in microorganism detection. PMID:23296330

  6. Activation Patterns throughout the Word Processing Network of L1-dominant Bilinguals Reflect Language Similarity and Language Decisions.

    PubMed

    Oganian, Yulia; Conrad, Markus; Aryani, Arash; Spalek, Katharina; Heekeren, Hauke R

    2015-11-01

    A crucial aspect of bilingual communication is the ability to identify the language of an input. Yet, the neural and cognitive basis of this ability is largely unknown. Moreover, it cannot be easily incorporated into neuronal models of bilingualism, which posit that bilinguals rely on the same neural substrates for both languages and concurrently activate them even in monolingual settings. Here we hypothesized that bilinguals can employ language-specific sublexical (bigram frequency) and lexical (orthographic neighborhood size) statistics for language recognition. Moreover, we investigated the neural networks representing language-specific statistics and hypothesized that language identity is encoded in distributed activation patterns within these networks. To this end, German-English bilinguals made speeded language decisions on visually presented pseudowords during fMRI. Language attribution followed lexical neighborhood sizes both in first (L1) and second (L2) language. RTs revealed an overall tuning to L1 bigram statistics. Neuroimaging results demonstrated tuning to L1 statistics at sublexical (occipital lobe) and phonological (temporoparietal lobe) levels, whereas neural activation in the angular gyri reflected sensitivity to lexical similarity to both languages. Analysis of distributed activation patterns reflected language attribution as early as in the ventral stream of visual processing. We conclude that in language-ambiguous contexts visual word processing is dominated by L1 statistical structure at sublexical orthographic and phonological levels, whereas lexical search is determined by the structure of both languages. Moreover, our results demonstrate that language identity modulates distributed activation patterns throughout the reading network, providing a key to language identity representations within this shared network.

  7. Individual differences in cognitive style and strategy predict similarities in the patterns of brain activity between individuals.

    PubMed

    Miller, Michael B; Donovan, Christa-Lynn; Bennett, Craig M; Aminoff, Elissa M; Mayer, Richard E

    2012-01-02

    Neuroimaging is being used increasingly to make inferences about an individual. Yet, those inferences are often confounded by the fact that topographical patterns of task-related brain activity can vary greatly from person to person. This study examined two factors that may contribute to the variability across individuals in a memory retrieval task: individual differences in cognitive style and individual differences in encoding strategy. Cognitive style was probed using a battery of assessments focused on the individual's tendency to visualize or verbalize written material. Encoding strategy was probed using a series of questions designed to assess typical strategies that an individual might utilize when trying to remember a list of words. Similarity in brain activity was assessed by cross-correlating individual t-statistic maps contrasting the BOLD response during retrieval to the BOLD response during fixation. Individual differences in cognitive style and encoding strategy accounted for a significant portion of the variance in similarity. This was true above and beyond individual differences in anatomy and memory performance. These results demonstrate the need for a multidimensional approach in the use of fMRI to make inferences about an individual.

  8. Pigeon circoviruses display patterns of recombination, genomic secondary structure and selection similar to those of beak and feather disease viruses.

    PubMed

    Stenzel, Tomasz; Piasecki, Tomasz; Chrząstek, Klaudia; Julian, Laurel; Muhire, Brejnev M; Golden, Michael; Martin, Darren P; Varsani, Arvind

    2014-06-01

    Pigeon circovirus (PiCV) has a ~2 kb genome circular ssDNA genome. All but one of the known PiCV isolates have been found infecting pigeons in various parts of the world. In this study, we screened 324 swab and tissue samples from Polish pigeons and recovered 30 complete genomes, 16 of which came from birds displaying no obvious pathology. Together with 17 other publicly available PiCV complete genomes sampled throughout the Northern Hemisphere and Australia, we find that PiCV displays a similar degree of genetic diversity to that of the related psittacine-infecting circovirus species, beak and feather disease virus (BFDV). We show that, as is the case with its pathology and epidemiology, PiCV also displays patterns of recombination, genomic secondary structure and natural selection that are generally very similar to those of BFDV. It is likely that breeding facilities play a significant role in the emergence of new recombinant PiCV variants and given that ~50 % of the domestic pigeon population is infected subclinically, all pigeon breeding stocks should be screened routinely for this virus.

  9. Additional Drug Resistance Patterns among Multidrug-Resistant Tuberculosis Patients in Korea: Implications for Regimen Design

    PubMed Central

    2017-01-01

    Detailed information on additional drug resistance patterns of multidrug-resistant tuberculosis (MDR-TB) is essential to build an effective treatment regimen; however, such data are scarce in Korea. We retrospectively analyzed the results of phenotypic drug susceptibility testing (DST) of culture confirmed-TB patients from January 2010 to December 2014 in 7 university hospitals in Korea. MDR-TB was identified among 6.8% (n = 378) of 5,599 isolates. A total of 57.1% (n = 216) of the MDR-TB patients had never been treated for TB. Strains from MDR-TB patients showed additional resistance to pyrazinamide (PZA) (35.7%), any second-line injectable drug (19.3%), and any fluoroquinolone (26.2%). Extensively drug resistant TB comprised 12.4% (n = 47) of the MDR-TB patients. Of 378 MDR-TB patients, 50.3% (n = 190) were eligible for the shorter MDR-TB regimen, and 50.0% (n = 189) were fully susceptible to the 5 drugs comprising the standard conventional regimen (PZA, kanamycin, ofloxoacin, prothionamide, and cycloserine). In conclusion, the proportion of new patients and the levels of additional drug resistance were high in MDR-TB patients. Considering the high levels of drug resistance, the shorter MDR-TB treatment regimen may not be feasible; instead, an individually tailored regimen based on the results of molecular and phenotypic DST may be more appropriate in MDR-TB patients in Korea. PMID:28244290

  10. Hierarchical pattern formation through photo-induced disorder in block copolymer/additive composite films

    NASA Astrophysics Data System (ADS)

    Yao, Li; Watkins, James

    2013-03-01

    Segregation strength in hybrid materials can be increased through selective hydrogen bonding between organic or nanoparticle additives and one block of weakly segregated block copolymers to generate well ordered hybrid materials. Here, we report the use of enantiopure tartaric acid as the additive to dramatically improve ordering in poly(ethylene oxide-block-tert-butyl acrylate) (PEO-b-PtBA) copolymers. Phase behavior and morphologies within both bulk and thin films were studied by TEM, AFM and X-ray scattering. Suppression of PEO crystallization by the interaction between tartaric acid and the PEO block enables the formation of well ordered smooth thin films. With the addition of a photo acid generator, photo-induced disorder in PEO-b-PtBA/tartaric acid composite system can be achieved upon UV exposure to deprotect PtBA block to yield poly(acrylic acid) (PAA), which is phase-miscible with PEO. Due to the strong interaction of tartaric acid with both blocks, the system undergoes a disordering transition within seconds during a post-exposure baking. With the assistance of trace-amounts of base quencher, high resolution, hierarchical patterns of sub-micron regions of ordered and disordered domains were achieved in thin films through area-selective UV exposure using a photo-mask. Funding from Center for Hierarchical Manufacturing (CHM); Facility support from Materials Research Science and Engineering Center at UMass Amherst and Cornell High Energy Synchrotron Source

  11. Pattern of inbreeding depression, condition dependence, and additive genetic variance in Trinidadian guppy ejaculate traits

    PubMed Central

    Gasparini, Clelia; Devigili, Alessandro; Dosselli, Ryan; Pilastro, Andrea

    2013-01-01

    In polyandrous species, a male's reproductive success depends on his fertilization capability and traits enhancing competitive fertilization success will be under strong, directional selection. This leads to the prediction that these traits should show stronger condition dependence and larger genetic variance than other traits subject to weaker or stabilizing selection. While empirical evidence of condition dependence in postcopulatory traits is increasing, the comparison between sexually selected and ‘control’ traits is often based on untested assumption concerning the different strength of selection acting on these traits. Furthermore, information on selection in the past is essential, as both condition dependence and genetic variance of a trait are likely to be influenced by the pattern of selection acting historically on it. Using the guppy (Poecilia reticulata), a livebearing fish with high levels of multiple paternity, we performed three independent experiments on three ejaculate quality traits, sperm number, velocity, and size, which have been previously shown to be subject to strong, intermediate, and weak directional postcopulatory selection, respectively. First, we conducted an inbreeding experiment to determine the pattern of selection in the past. Second, we used a diet restriction experiment to estimate their level of condition dependence. Third, we used a half-sib/full-sib mating design to estimate the coefficients of additive genetic variance (CVA) underlying these traits. Additionally, using a simulated predator evasion test, we showed that both inbreeding and diet restriction significantly reduced condition. According to predictions, sperm number showed higher inbreeding depression, stronger condition dependence, and larger CVA than sperm velocity and sperm size. The lack of significant genetic correlation between sperm number and velocity suggests that the former may respond to selection independently one from other ejaculate quality traits

  12. Similarities and differences between eating disorders and obese patients in a virtual environment for normalizing eating patterns.

    PubMed

    Perpiñá, Conxa; Roncero, María

    2016-05-01

    Virtual reality has demonstrated promising results in the treatment of eating disorders (ED); however, few studies have examined its usefulness in treating obesity. The aim of this study was to compare ED and obese patients on their reality judgment of a virtual environment (VE) designed to normalize their eating pattern. A second objective was to study which variables predicted the reality of the experience of eating a virtual forbidden-fattening food. ED patients, obese patients, and a non-clinical group (N=62) experienced a non-immersive VE, and then completed reality judgment and presence measures. All participants rated the VE with similar scores for quality, interaction, engagement, and ecological validity; however, ED patients obtained the highest scores on emotional involvement, attention, reality judgment/presence, and negative effects. The obese group gave the lowest scores to reality judgment/presence, satisfaction and sense of physical space, and they held an intermediate position in the attribution of reality to virtually eating a "fattening" food. The palatability of a virtual food was predicted by attention capturing and belonging to the obese group, while the attribution of reality to the virtual eating was predicted by engagement and belonging to the ED group. This study offers preliminary results about the differential impact on ED and obese patients of the exposure to virtual food, and about the need to implement a VE that can be useful as a virtual lab for studying eating behavior and treating obesity.

  13. Additive Fabrication of Conductive Patterns by a Template Transfer Process Based on Benzotriazole Adsorption As a Separation Layer.

    PubMed

    Chang, Yu; Yang, Zhen-Guo

    2016-06-08

    The traditional subtractive process to fabricate conductive patterns is environmentally harmful, wasteful, and limited in line width. The additive process, including direct printing of conductive paste or ink, direct printing of catalytic ink, laser-induced forward transfer, etc., can solve these problems. However, the current additive process also faces many difficulties such as low electrical and adhesion properties, low pattern thickness, high cost, etc. Benzotriazole (BTA), as widely used corrosion inhibitor, can be adsorbed onto a copper surface. The electroplated copper film on BTA-adsorbed copper foil shows poor adhesion. On the basis of this phenomenon, a novel template transfer process to additively fabricate conductive patterns has been developed. A permeant antiadhesive mask is printed on carrier copper foil, and then, BTA is adsorbed onto the exposed area of the carrier foil, thus forming the template. The template is electroplated to grow conductive patterns in the exposed parts, and then can be adhered to the flexible substrate. The substrate is peeled off, with the transfer of the conductive patterns to the substrate, to form the designed conductive patterns on PET. By reimmersing the template into BTA solution, the template can be used again. The mechanism of BTA adsorption and the reason for the low peeling strength are researched using Raman spectra, XPS and electrochemical impedance spectroscopy. Copper patterns more than 20 μm in thickness can be prepared on PET, the resistivity of the prepared copper patterns is 2.01 μΩ cm, which is about the same as bulk copper, and the peeling strength of the pattern on PET is measured to be 6.97 N/cm. This template transfer process, with no waste, low pollution, high electrical and adhesion properties, and low cost, shows high potential in the large scale manufacturing of electronic devices, such as RFID circuitry, FPCs, etc.

  14. Similar DNA methylation and histone H3 lysine 9 dimethylation patterns in tripronuclear and corrected bipronuclear human zygotes.

    PubMed

    Chen, Xinjie; Fan, Yong; Long, Xiaolin; Sun, Xiaofang

    2010-06-01

    After fertilization, male and female gametes undergo extensive reprogramming to restore totipotency. Both DNA methylation and histone modification are important epigenetic reprogramming events. Previous studies have reported that the paternal pronucleus of the human zygote is actively demethylated to some extent, while the maternal pronucleus remains methylated. However, to our knowledge, the relationship between DNA methylation and H3K9 dimethylation patterns in human embryos has not been reported. In this study, we examined the dynamic DNA methylation and H3K9 dimethylation patterns in triploid and bipronucleated zygotes and early developing embryos. We sought to gain further insight into the relationship between DNA methylation and H3K9 dimethylation and to investigate whether removing a pronucleus from triploid zygotes affects DNA methylation and H3K9 dimethylation patterns. We found that active DNA demethylation of the two male pronuclei occurred in tripronuclear human zygotes while the female pronucleus remained methylated at 20 h post-insemination. In tripronuclear human zygotes, H3K9 was hypomethylated in the two paternal pronuclei relative to the maternal pronucleus. Our data show that there are no differences in the DNA methylation and H3K9 dimethylation patterns between tripronuclear and corrected bipronuclear human zygotes. However, correction of 3PN human zygotes dispermic in origin could not improve subsequent embryo development. In conclusion, DNA methylation and H3K9 dimethylation patterns are well correlated in tripronuclear zygotes and embryos; early embryo development is not affected by removal of a male pronucleus. Our results imply that limited developmental potential of either 3PN or corrected 2PN embryos may not be caused by the abnormalities in DNA methylation or H3K9 dimethylation modification.

  15. Identifying associations in Escherichia coli antimicrobial resistance patterns using additive Bayesian networks.

    PubMed

    Ludwig, Antoinette; Berthiaume, Philippe; Boerlin, Patrick; Gow, Sheryl; Léger, David; Lewis, Fraser I

    2013-05-15

    While the genesis of antimicrobial resistance (AMR) in animal production is a high profile topic in the media and the scientific community, it is still not well understood. The epidemiology of AMR is complex. This complexity is demonstrated by extensive biological and evolutionary mechanisms which are potentially impacted by farm management and husbandry practices - the risk factors. Many parts of this system have yet to be fully described. Notably, the occurrence of multiple resistance patterns is the rule rather than exception - the multivariate problem. A first essential step in the development of any comprehensive risk factor analysis - whose goal is the prevention or reduction of AMR - is to describe those associations between different patterns of resistance which are systematic. That is, have sufficient statistical support for these patterns to be considered robust features of the underlying epidemiological system, and whose presence must therefore be incorporated into any risk factor analysis of AMR for it to be meaningful with respect to the farm environment. Presented here is a case study that seeks to identify systematic associations between patterns of resistance to 13 different antimicrobials in Escherichia coli isolates obtained from composite finisher (>80 kg) pig faecal samples obtained from Canada's five major pork producing provinces. The use of a Bayesian network analysis approach allowed us to identify many systematic associations between individual antimicrobial resistances. Sixteen of these resistances are corroborated with existing literature. These associations are distributed between several important classes of antimicrobials including the β-lactams, folate biosynthesis inhibitors, tetracyclines, aminoglycosides and quinolones. This study presents an exciting first step towards the larger and far more ambitious goal of developing generic and holistic risk factor analyses for on-farm occurrence of AMR. Analyses of this nature would combine

  16. Bioavailability of zinc oxide added to corn tortilla is similar to that of zinc sulfate and is not affected by simultaneous addition of iron

    PubMed Central

    Rosado, Jorge L.; Díaz, Margarita; Muñoz, Elsa; Westcott, Jamie L.; González, Karla E.; Krebs, Nancy F.; Caamaño, María C.; Hambidge, Michael

    2013-01-01

    Background Corn tortilla is the staple food of Mexico and its fortification with zinc, iron, and other micronutrients is intended to reduce micronutrient deficiencies. However, no studies have been performed to determine the relative amount of zinc absorbed from the fortified product and whether zinc absorption is affected by the simultaneous addition of iron. Objective To compare zinc absorption from corn tortilla fortified with zinc oxide versus zinc sulfate and to determine the effect of simultaneous addition of two doses of iron on zinc bioavailability. Methods A randomized, double-blind, crossover design was carried out in two phases. In the first phase, 10 adult women received corn tortillas with either 20 mg/kg of zinc oxide added, 20 mg/kg of zinc sulfate added, or no zinc added. In the second phase, 10 adult women received corn tortilla with 20 mg/kg of zinc oxide added and either with no iron added or with iron added at one of two different levels. Zinc absorption was measured by the stable isotope method. Results The mean (± SEM) fractional zinc absorption from unfortified tortilla, tortilla fortified with zinc oxide, and tortilla fortified with zinc sulfate did not differ among treatments: 0.35 ± 0.07, 0.36 ± 0.05, and 0.37 ± 0.07, respectively. The three treatment groups with 0, 30, and 60 mg/kg of added iron had similar fractional zinc absorption (0.32 ± 0.04, 0.33 ± 0.02, and 0.32 ± 0.05, respectively) and similar amounts of zinc absorbed (4.8 ± 0.7, 4.5 ± 0.3, and 4.8 ± 0.7 mg/day, respectively). Conclusions Since zinc oxide is more stable and less expensive and was absorbed equally as well as zinc sulfate, we suggest its use for corn tortilla fortification. Simultaneous addition of zinc and iron to corn tortilla does not modify zinc bioavailability at iron doses of 30 and 60 mg/kg of corn flour. PMID:23424892

  17. Pattern transition and sluggish cracking of colloidal droplet deposition with polymer additives

    NASA Astrophysics Data System (ADS)

    Zhang, YongJian; Liu, ZhengTang; Zang, DuYang; Qian, YiMeng; Lin, KeJun

    2013-09-01

    Drying of colloidal droplets often develops versatile depositions. We study the drying deposition of both colloidal droplets containing silica nanoparticles and the silica colloidal droplets with polyethylene oxide (PEO) additives. We focus on the effect of polymer additives on the deposition formation and the cracking dynamics by using in-situ microscope observation. With PEO additives, a transition from ring-like deposition to uniform deposition is observed, and the cracking dynamics is greatly reduced. The PEO additives enhance the adsorption of particles at the air-water interface, thus forming the network structure at the interface which blocks the outward capillary flow. This contributes to the uniform deposition. Meanwhile, the multi-distribution of the aggregates size enhances the non-homogeneity of the drying film and consequently results in multi-nucleation of cracks. This reduces the stress accumulation that drives the crack propagation and may be responsible for the sluggish cracking dynamics.

  18. Docking pose selection by interaction pattern graph similarity: application to the D3R grand challenge 2015

    NASA Astrophysics Data System (ADS)

    Slynko, Inna; Da Silva, Franck; Bret, Guillaume; Rognan, Didier

    2016-09-01

    High affinity ligands for a given target tend to share key molecular interactions with important anchoring amino acids and therefore often present quite conserved interaction patterns. This simple concept was formalized in a topological knowledge-based scoring function (GRIM) for selecting the most appropriate docking poses from previously X-rayed interaction patterns. GRIM first converts protein-ligand atomic coordinates (docking poses) into a simple 3D graph describing the corresponding interaction pattern. In a second step, proposed graphs are compared to that found from template structures in the Protein Data Bank. Last, all docking poses are rescored according to an empirical score (GRIMscore) accounting for overlap of maximum common subgraphs. Taking the opportunity of the public D3R Grand Challenge 2015, GRIM was used to rescore docking poses for 36 ligands (6 HSP90α inhibitors, 30 MAP4K4 inhibitors) prior to the release of the corresponding protein-ligand X-ray structures. When applied to the HSP90α dataset, for which many protein-ligand X-ray structures are already available, GRIM provided very high quality solutions (mean rmsd = 1.06 Å, n = 6) as top-ranked poses, and significantly outperformed a state-of-the-art scoring function. In the case of MAP4K4 inhibitors, for which preexisting 3D knowledge is scarce and chemical diversity is much larger, the accuracy of GRIM poses decays (mean rmsd = 3.18 Å, n = 30) although GRIM still outperforms an energy-based scoring function. GRIM rescoring appears to be quite robust with comparison to the other approaches competing for the same challenge (42 submissions for the HSP90 dataset, 27 for the MAP4K4 dataset) as it ranked 3rd and 2nd respectively, for the two investigated datasets. The rescoring method is quite simple to implement, independent on a docking engine, and applicable to any target for which at least one holo X-ray structure is available.

  19. Sleep patterns and psychological functioning in families in northeastern Iran; evidence for similarities between adolescent children and their parents.

    PubMed

    Bajoghli, Hafez; Alipouri, Aazam; Holsboer-Trachsler, Edith; Brand, Serge

    2013-12-01

    Sleep and well-being of adolescents and their parents are related, but data from non-Western countries are scarce. The aim of the present study was to investigate the relationship between adolescents' and their parents' sleep patterns and psychological functioning in northeastern Iran. A total of 81 families (81 mothers, 78 fathers, 130 children aged 12-20 years) took part in the study. They individually and separately completed questionnaires related to sleep and psychological functioning. Sleep quality was related within families. Poor sleep among children and parents was related in each case to more depressive symptoms and stress. Mothers' sleep and psychological functioning were more related to adolescent children's sleep and psychological functioning than were those of fathers. Results confirm research showing that adolescent's and parents' sleep and psychological functioning are inter-related. This association holds also true for families in northeastern Iran, suggesting that the association reflects universal features of family functioning.

  20. Divergent patterns of allelic diversity from similar origins: the case of oilseed rape (Brassica napus L.) in China and Australia.

    PubMed

    Chen, S; Nelson, M N; Ghamkhar, K; Fu, T; Cowling, W A

    2008-01-01

    Oilseed rape (Brassica napus) in Australia and China have similar origins, with introductions from Europe, Canada, and Japan in the mid 20th century, and there has been some interchange of germplasm between China and Australia since that time. Allelic diversity of 72 B. napus genotypes representing contemporary germplasm in Australia and China, including samples from India, Europe, and Canada, was characterized by 55 polymorphic simple sequence repeat (SSR) markers spanning the entire B. napus genome. Hierarchical clustering and two-dimensional multidimensional scaling identified a Chinese group (China-1) that was separated from "mixed group" of Australian, Chinese (China-2), European, and Canadian lines. A small group from India was distinctly separated from all other B. napus genotypes. Chinese genotypes, especially in the China-1 group, have inherited unique alleles from interspecific crossing, primarily with B. rapa, and the China-2 group has many alleles in common with Australian genotypes. The concept of "private alleles" is introduced to describe both the greater genetic diversity and the genetic distinctiveness of Chinese germplasm, compared with Australian germplasm, after 50 years of breeding from similar origins.

  1. Similar or disparate brain patterns? The intra-personal EEG variability of three women with multiple personality disorder.

    PubMed

    Lapointe, A R; Crayton, J W; DeVito, R; Fichtner, C G; Konopka, L M

    2006-07-01

    Quantitative EEG was used to assess the intra-personal variability of brain electrical activity for 3 women diagnosed with Multiple Personality Disorder (MPD). Two separate control groups (within-subject and between-subject) were used to test the hypothesis that the intra-personal EEG variability between 2 alters would be less than the interpersonal EEG variability between 2 controls, and similar to the intra-personal EEG variability of a single personality. This hypothesis was partially supported. In general, the 2 EEG records of a MPD subject (alter 1 vs. alter 2) were more different from one another than the 2 EEG records of a single control, but less different from one another than the EEG records of 2 separate controls. Most of the EEG variability between alters involved beta activity in the frontal and temporal lobes.

  2. Similar patterns of frequency-dependent selection on animal personalities emerge in three species of social spiders.

    PubMed

    Lichtenstein, J L L; Pruitt, J N

    2015-06-01

    Frequency-dependent selection is thought to be a major contributor to the maintenance of phenotypic variation. We tested for frequency-dependent selection on contrasting behavioural strategies, termed here 'personalities', in three species of social spiders, each thought to represent an independent evolutionary origin of sociality. The evolution of sociality in the spider genus Anelosimus is consistently met with the emergence of two temporally stable discrete personality types: an 'aggressive' or 'docile' form. We assessed how the foraging success of each phenotype changes as a function of its representation within a colony. We did this by creating experimental colonies of various compositions (six aggressives, three aggressives and three dociles, one aggressive and five dociles, six dociles), maintaining them in a common garden for 3 weeks, and tracking the mass gained by individuals of either phenotype. We found that both the docile and aggressive phenotypes experienced their greatest mass gain in mixed colonies of mostly docile individuals. However, the performance of both phenotypes decreased as the frequency of the aggressive phenotype increased. Nearly identical patterns of phenotype-specific frequency dependence were recovered in all three species. Naturally occurring colonies of these spiders exhibit mixtures dominated by the docile phenotype, suggesting that these spiders may have evolved mechanisms to maintain the compositions that maximize the success of the colony without compromising the expected reproductive output of either phenotype.

  3. Selectivity in the Addition Reactions of Organometallic Reagents to Aziridine-2-carboxaldehydes: The Effects of Protecting Groups and Substitution Patterns

    PubMed Central

    Kulshrestha, Aman; Schomaker, Jennifer M.; Holmes, Daniel; Staples, Richard J.; Jackson, James E.; Borhan, Babak

    2014-01-01

    Good to excellent stereo-selectivity has been found in the addition reactions of Grignard and organo-zinc reagents to N-protected aziridine-2-carboxaldehydes. Specifically, high syn selectivity was obtained with benzyl-protected cis, tert-butyloxycar-bonyl-protected trans, and tosyl-pro-tected 2,3-disubstituted aziridine-2-car-boxaldehydes. Furthermore, rate and selectivity effects of ring substituents, temperature, solvent, and Lewis acid and base modifiers were studied. The diastereomeric preference of addition is dominated by the substrate aziri-dines’ substitution pattern and especially the electronic character and conformational preferences of the nitrogen protecting groups. To help rationalize the observed stereochemical outcomes, conformational and electronic structural analyses of a series of model systems representing the various substitution patterns have been explored by density functional calculations at the B3LYP/6–31G* level of theory with the SM8 solvation model to account for solvent effects. PMID:21928447

  4. Morphometric patterns in Modern carbonate platforms can be applied to the ancient rock record: Similarities between Modern Alacranes Reef and Upper Palaeozoic platforms of the Barents Sea

    NASA Astrophysics Data System (ADS)

    Purkis, Sam; Casini, Giulio; Hunt, Dave; Colpaert, Arnout

    2015-05-01

    In recent years, considerable research has been undertaken in order to gain a better quantitative understanding of morphometric patterns within modern carbonate depositional systems. The industrial application of the scaling/juxtaposition relationships derived from the Modern to subsurface Cenozoic carbonate reservoirs appears relatively straightforward, given that many key biota are common to both. However, the direct application of Modern sedimentary insight further back into the geologic rock record is more controversial, given the enormous changes in the biota, climate, sea level, water chemistry and so on, that have taken place. To justify such an approach, we contend that similar morphometric patterns should be observed in both the Modern and ancient data. In the Norwegian Barents Sea, numerous seismic surveys have imaged Upper Palaeozoic carbonate buildups arranged in polygonal networks, or reticular patterns. These patterns are observed in both warm water photozoan and cool water heterozoan carbonate stratigraphies, and are developed atop platforms founded on stable shelves, in tectonically active settings and platforms developed over basinal evaporites. GIS mapping of multiple seismic horizons allows the Palaeozoic reticulated morphology to be numerically compared to that mapped in Alacranes Reef from QuickBird satellite imagery. QuickBird's metre-scale resolution allows identification of subtle cross-platform trends, such as windward-leeward differences in the packing density of ridge-and-pond complexes, which can be correlated with the kilometre-scale patterning extracted in the Barents subsurface. Despite different controls and architecture, the patterning of reticular networks is statistically inseparable between the two systems, once the metre-scale Modern dataset is down-sampled to seismic resolution. Whilst other controls cannot unequivocally be ruled out, these results suggest that biotic self-organisation is a fundamental driver of sedimentary

  5. Influence of the addition of rosemary essential oil on the volatiles pattern of porcine frankfurters.

    PubMed

    Estévez, Mario; Ventanas, Sonia; Ramírez, Rosario; Cava, Ramón

    2005-10-19

    The effect of the addition of increasing levels of rosemary essential oil (150, 300, and 600 mg/kg) on the generation of volatile compounds in frankfurters from Iberian and white pigs was analyzed using solid-phase microextraction coupled to gas chromatography and mass spectrometry (SPME-GC-MS). Lipid-derived volatiles such as aldehydes (hexanal, octanal, nonanal) and alcohols (pentan-1-ol, hexan-1-ol, oct-1-en-3-ol) were the most abundant compounds in the headspace (HS) of porcine frankfurters. Frankfurters from different pig breeds presented different volatile profiles due to their different oxidation susceptibilities as a likely result of their fatty acid composition and vitamin E content. Rosemary essential oil showed a different effect on the generation of volatiles depending on the type of frankfurter in which they were added. In frankfurters from Iberian pigs, the antioxidant effect of the essential oil improved with increasing levels, showing the highest activity at 600 mg/kg. In contrast, 150 mg/kg of the essential oil improved the oxidative stability of frankfurters from white pigs, whereas higher levels led to no effect or a prooxidant effect. The activity of the essential oil could have been affected by the different fatty acid compositions and vitamin E contents between types of frankfurters. SPME successfully allowed the isolation and analysis of volatile terpenes from frankfurters with added rosemary essential oil including alpha-pinene, beta-myrcene, l-limonene, (E)-caryophyllene, linalool, camphor, and 1,8-cineole, which might contribute to the aroma characteristics of frankfurters.

  6. In vitro adherence patterns of Shigella serogroups to bovine recto-anal junction squamous epithelial (RSE) cells are similar to those of Escherichia coli O157.

    PubMed

    Kudva, Indira T

    2012-04-01

    The aims of this study were to determine whether Shigella species, which are human gastrointestinal pathogens, can adhere to cattle recto-anal junction squamous epithelial (RSE) cells using a recently standardized in vitro adherence assay, and to compare their adherence patterns with that of Escherichia coli O157. Shigella dysenteriae (serogroup A), S. flexneri (serogroup B), S. boydii (serogroup C), and S. sonnei (serogroup D) were tested in adherence assays using both RSE and HEp-2 cells, in the presence or absence of D+mannose. Escherichia coli O157, which adheres to RSE cells in a Type I fimbriae-independent manner, was used as a positive control. Shigella serogroups A, B, D, but not C adhered to RSE cells with distinct adherence patterns in the presence of D+mannose. No such distinction could be made between the four Shigella serogroups based on the HEp-2 cell adherence patterns. Thus, this study provides evidence that certain Shigella serogroups adhere to RSE cells in a manner that is similar to the adherence pattern of E. coli O157. These unexpected observations of in vitro binding of these foodborne human pathogens to cells of the bovine gastrointestinal tract warrant evaluation of Shigella carriage by cattle using both experimental and observational studies, especially for serogroups B and D. Such studies are currently underway.

  7. Assigning Peptide Disulfide Linkage Pattern Among Regio-Isomers via Methoxy Addition to Disulfide and Tandem Mass Spectrometry

    NASA Astrophysics Data System (ADS)

    Durand, Kirt L.; Tan, Lei; Stinson, Craig A.; Love-Nkansah, Chasity B.; Ma, Xiaoxiao; Xia, Yu

    2017-02-01

    Pinpointing disulfide linkage pattern is critical in the characterization of proteins and peptides consisting of multiple disulfide bonds. Herein, we report a method based on coupling online disulfide modification and tandem mass spectrometry (MS/MS) to distinguish peptide disulfide regio-isomers. Such a method relies on a new disulfide bond cleavage reaction in solution, involving methanol as a reactant and 254 nm ultraviolet (UV) irradiation. This reaction leads to selective cleavage of a disulfide bond and formation of sulfenic methyl ester (-SOCH3) at one cysteine residue and a thiol (-SH) at the other. Under low energy collision-induced dissociation (CID), cysteine sulfenic methyl ester motif produces a signature methanol loss (-32 Da), allowing its identification from other possible isomeric structures such as S-hydroxylmethyl (-SCH2OH) and methyl sulfoxide (-S(O)-CH3). Since disulfide bond can be selectively cleaved and modified upon methoxy addition, subsequent MS2 CID of the methoxy addition product provides enhanced sequence coverage as demonstrated by the analysis of bovine insulin. More importantly, this reaction does not induce disulfide scrambling, likely due to the fact that radical intermediates are not involved in the process. An approach based on methoxy addition followed by MS3 CID has been developed for assigning disulfide linkage patterns in peptide disulfide regio-isomers. This methodology was successfully applied to characterizing peptide systems having two disulfide bonds and three disulfide linkage isomers: side-by-side, overlapped, and looped-within-a-loop configurations.

  8. Comparison of several supervised pattern recognition techniques for detecting additive methamidophos in rotenone preparation by near-infrared spectroscopy.

    PubMed

    Tang, Guo; Tian, Kuangda; Song, Xiangzhong; Xiong, Yanmei; Min, Shungeng

    2014-01-01

    In this paper, different supervised pattern recognition methods have been applied to detect the manually additive methamidophos in rotenone preparation. The aim of this paper was to examine the performances of different supervised pattern recognition techniques: soft independent modeling of class analogy (SIMCA), partial least squares discriminant analysis (PLS-DA), artificial neutral networks (ANN), and support vector machine (SVM). The results obtained show that SVM is the most effective techniques with 100.0% classification accuracy followed by ANN, PLS-DA and with the accuracy of 97.5% and 93.3% respectively while SIMCA yields the poorest result of 85.8%. We hope that the results obtained in this study will help both further chemometric investigations and investigations in the sphere of applied vibrational spectroscopy of sophisticated multicomponent systems. Furthermore, the use of portable instrument and satisfactory classification also indicated the possibility of detecting illicit-addition at scene by near-infrared (NIR) spectroscopy which makes a great sense in pesticide quality control.

  9. What are the evolutionary mechanisms explaining the similar species richness patterns in tropical mosses? Insights from the phylogeny of the pantropical genus Pelekium.

    PubMed

    Norhazrina, Nik; Vanderpoorten, Alain; Hedenäs, Lars; Patiño, Jairo

    2016-12-01

    As opposed to angiosperms, moss species richness is similar among tropical regions of the world, in line with the hypothesis that tropical bryophytes are extremely good dispersers. Here, we reconstructed the phylogeny of the pantropical moss genus Pelekium to test the hypothesis that high migration rates erase any difference in species richness among tropical regions. In contrast with this hypothesis, several species considered to have a pantropical range were resolved as a complex of species with a strong geographic structure. Consequently, a significant phylogeographical signal was found in the data, evidencing that cladogenetic diversification within regions takes place at a faster rate than intercontinental migration. The shape of the Pelekium phylogeny, along with the selection of a constant-rate model of diversification among species in the genus, suggests, however, that the cladogenetic speciation patterns observed in Pelekium are not comparable to some of the spectacular examples of tropical radiations reported in angiosperms. Rather, the results presented here point to the constant accumulation of diversity through time in Pelekium. This, combined with evidence for long-distance dispersal limitations in the genus, suggests that the similar patterns of species richness among tropical areas are better explained in terms of comparable rates of diversification across tropical regions than by the homogenization of species richness by recurrent migrations.

  10. Ecosystem functional assessment based on the "optical type" concept and self-similarity patterns: An application using MODIS-NDVI time series autocorrelation

    NASA Astrophysics Data System (ADS)

    Huesca, Margarita; Merino-de-Miguel, Silvia; Eklundh, Lars; Litago, Javier; Cicuéndez, Victor; Rodríguez-Rastrero, Manuel; Ustin, Susan L.; Palacios-Orueta, Alicia

    2015-12-01

    Remote sensing (RS) time series are an excellent operative source for information about the land surface across several scales and different levels of landscape heterogeneity. Ustin and Gamon (2010) proposed the new concept of "optical types" (OT), meaning "optically distinguishable functional types", as a way to better understand remote sensing signals related to the actual functional behavior of species that share common physiognomic forms but differ in functionality. Whereas the OT approach seems to be promising and consistent with ecological theory as a way to monitor vegetation derived from RS, it received little implementation. This work presents a method for implementing the OT concept for efficient monitoring of ecosystems based on RS time series. We propose relying on an ecosystem's repetitive pattern in the temporal domain (self-similarity) to assess its dynamics. Based on this approach, our main hypothesis is that distinct dynamics are intrinsic to a specific OT. Self-similarity level in the temporal domain within a broadleaf forest class was quantitatively assessed using the auto-correlation function (ACF), from statistical time series analysis. A vector comparison classification method, spectral angle mapper, and principal component analysis were used to identify general patterns related to forest dynamics. Phenological metrics derived from MODIS NDVI time series using the TIMESAT software, together with information from the National Forest Map were used to explain the different dynamics found. Results showed significant and highly stable self-similarity patterns in OTs that corresponded to forests under non-moisture-limited environments with an adaptation strategy based on a strong phenological synchrony with climate seasonality. These forests are characterized by dense closed canopy deciduous forests associated with high productivity and low biodiversity in terms of dominant species. Forests in transitional areas were associated with patterns of less

  11. Fine-Scale Vertical Stratification and Guild Composition of Saproxylic Beetles in Lowland and Montane Forests: Similar Patterns despite Low Faunal Overlap

    PubMed Central

    Weiss, Matthias; Procházka, Jiří; Schlaghamerský, Jiří; Cizek, Lukas

    2016-01-01

    Objective The finer scale patterns of arthropod vertical stratification in forests are rarely studied and poorly understood. Further, there are no studies investigating whether and how altitude affects arthropod vertical stratification in temperate forests. We therefore investigated the fine-scale vertical stratification of diversity and guild structure of saproxylic beetles in temperate lowland and montane forests and compared the resulting patterns between the two habitats. Methods The beetles were sampled with flight intercept traps arranged into vertical transects (sampling heights 0.4, 1.2, 7, 14, and 21 m). A triplet of such transects was installed in each of the five sites in the lowland and in the mountains; 75 traps were used in each forest type. Results 381 species were collected in the lowlands and 236 species in the mountains. Only 105 species (21%) were found at both habitats; in the montane forest as well as in the lowlands, the species richness peaked at 1.2 m, and the change in assemblage composition was most rapid near the ground. The assemblages clearly differed between the understorey (0.4 m, 1.2 m) and the canopy (7 m, 14 m, 21 m) and between the two sampling heights within the understorey, but less within the canopy. The stratification was better pronounced in the lowland, where canopy assemblages were richer than those near the forest floor (0.4 m). In the mountains the samples from 14 and 21 m were more species poor than those from the lower heights. The guild structure was similar in both habitats. Conclusions The main patterns of vertical stratification and guild composition were strikingly similar between the montane and the lowland forest despite the low overlap of their faunas. The assemblages of saproxylic beetles were most stratified near ground. The comparisons of species richness between canopy and understorey may thus give contrasting results depending on the exact sampling height in the understorey. PMID:26978783

  12. Assigning Peptide Disulfide Linkage Pattern Among Regio-Isomers via Methoxy Addition to Disulfide and Tandem Mass Spectrometry.

    PubMed

    Durand, Kirt L; Tan, Lei; Stinson, Craig A; Love-Nkansah, Chasity B; Ma, Xiaoxiao; Xia, Yu

    2017-02-13

    Pinpointing disulfide linkage pattern is critical in the characterization of proteins and peptides consisting of multiple disulfide bonds. Herein, we report a method based on coupling online disulfide modification and tandem mass spectrometry (MS/MS) to distinguish peptide disulfide regio-isomers. Such a method relies on a new disulfide bond cleavage reaction in solution, involving methanol as a reactant and 254 nm ultraviolet (UV) irradiation. This reaction leads to selective cleavage of a disulfide bond and formation of sulfenic methyl ester (-SOCH3) at one cysteine residue and a thiol (-SH) at the other. Under low energy collision-induced dissociation (CID), cysteine sulfenic methyl ester motif produces a signature methanol loss (-32 Da), allowing its identification from other possible isomeric structures such as S-hydroxylmethyl (-SCH2OH) and methyl sulfoxide (-S(O)-CH3). Since disulfide bond can be selectively cleaved and modified upon methoxy addition, subsequent MS(2) CID of the methoxy addition product provides enhanced sequence coverage as demonstrated by the analysis of bovine insulin. More importantly, this reaction does not induce disulfide scrambling, likely due to the fact that radical intermediates are not involved in the process. An approach based on methoxy addition followed by MS(3) CID has been developed for assigning disulfide linkage patterns in peptide disulfide regio-isomers. This methodology was successfully applied to characterizing peptide systems having two disulfide bonds and three disulfide linkage isomers: side-by-side, overlapped, and looped-within-a-loop configurations. Graphical Abstract ᅟ.

  13. Similar patterns of clonally expanded somatic mtDNA mutations in the colon of heterozygous mtDNA mutator mice and ageing humans

    PubMed Central

    Baines, Holly L.; Stewart, James B.; Stamp, Craig; Zupanic, Anze; Kirkwood, Thomas B.L.; Larsson, Nils-Göran; Turnbull, Douglass M.; Greaves, Laura C.

    2014-01-01

    Clonally expanded mitochondrial DNA (mtDNA) mutations resulting in focal respiratory chain deficiency in individual cells are proposed to contribute to the ageing of human tissues that depend on adult stem cells for self-renewal; however, the consequences of these mutations remain unclear. A good animal model is required to investigate this further; but it is unknown whether mechanisms for clonal expansion of mtDNA mutations, and the mutational spectra, are similar between species. Here we show that mice, heterozygous for a mutation disrupting the proof-reading activity of mtDNA polymerase (PolgA+/mut) resulting in an increased mtDNA mutation rate, accumulate clonally expanded mtDNA point mutations in their colonic crypts with age. This results in focal respiratory chain deficiency, and by 81 weeks of age these animals exhibit a similar level and pattern of respiratory chain deficiency to 70-year-old human subjects. Furthermore, like in humans, the mtDNA mutation spectrum appears random and there is an absence of selective constraints. Computer simulations show that a random genetic drift model of mtDNA clonal expansion can accurately model the data from the colonic crypts of wild-type, PolgA+/mut animals, and humans, providing evidence for a similar mechanism for clonal expansion of mtDNA point mutations between these mice and humans. PMID:24915468

  14. Flow pattern similarities in the near wake of three bird species suggest a common role for unsteady aerodynamic effects in lift generation.

    PubMed

    Gurka, Roi; Krishnan, Krishnamoorthy; Ben-Gida, Hadar; Kirchhefer, Adam J; Kopp, Gregory A; Guglielmo, Christopher G

    2017-02-06

    Analysis of the aerodynamics of flapping wings has yielded a general understanding of how birds generate lift and thrust during flight. However, the role of unsteady aerodynamics in avian flight due to the flapping motion still holds open questions in respect to performance and efficiency. We studied the flight of three distinctive bird species: western sandpiper (Calidris mauri), European starling (Sturnus vulgaris) and American robin (Turdus migratorius) using long-duration, time-resolved particle image velocimetry, to better characterize and advance our understanding of how birds use unsteady flow features to enhance their aerodynamic performances during flapping flight. We show that during transitions between downstroke and upstroke phases of the wing cycle, the near wake-flow structures vary and generate unique sets of vortices. These structures appear as quadruple layers of concentrated vorticity aligned at an angle with respect to the horizon (named 'double branch'). They occur where the circulation gradient changes sign, which implies that the forces exerted by the flapping wings of birds are modified during the transition phases. The flow patterns are similar in (non-dimensional) size and magnitude for the different birds suggesting that there are common mechanisms operating during flapping flight across species. These flow patterns occur at the same phase where drag reduction of about 5% per cycle and lift enhancement were observed in our prior studies. We propose that these flow structures should be considered in wake flow models that seek to account for the contribution of unsteady flow to lift and drag.

  15. Learning similarity with multikernel method.

    PubMed

    Tang, Yi; Li, Luoqing; Li, Xuelong

    2011-02-01

    In the field of machine learning, it is a key issue to learn and represent similarity. This paper focuses on the problem of learning similarity with a multikernel method. Motivated by geometric intuition and computability, similarity between patterns is proposed to be measured by their included angle in a kernel-induced Hilbert space. Having noticed that the cosine of such an included angle can be represented by a normalized kernel, it can be said that the task of learning similarity is equivalent to learning an appropriate normalized kernel. In addition, an error bound is also established for learning similarity with the multikernel method. Based on this bound, a boosting-style algorithm is developed. The preliminary experiments validate the effectiveness of the algorithm for learning similarity.

  16. Effect of Ag nanowire addition into nanoparticle paste on the conductivity of Ag patterns printed by gravure offset method.

    PubMed

    Ok, Ki-Hun; Lee, Chan-Jae; Kwak, Min-Gi; Choi, Duck-Kyun; Kim, Kwang-Seok; Jung, Seung-Boo; Kim, Jong-Woong

    2014-11-01

    This paper focuses on the effect of Ag nanowire addition into a commercial Ag nanopaste and the printability evaluation of the mixed paste by the gravure offset printing methodology. Ag nanowires were synthesized by a modified polyol method, and a small amount of them was added into a commercial metallic paste based on Ag nanoparticles of 50 nm in diameter. Two annealing temperatures were selected for comparison, and electrical conductivity was measured by four point probe method. As a result, the hybrid mixture could be printed by the gravure offset method for patterning fine lines up to 15 μm width with sharp edges and scarce spreading. The addition of the Ag nanowires was significantly efficient for enhancement of electrical conductivity of the printed lines annealed at a low temperature (150 degrees C), while the effect was somewhat diluted in case of high temperature annealing (200 degrees C). The experimental results were discussed with the conduction mechanism in the printed conductive circuits with a schematic description of the electron flows in the printed lines.

  17. The rediscovery of a long described species reveals additional complexity in speciation patterns of poeciliid fishes in sulfide springs.

    PubMed

    Palacios, Maura; Arias-Rodriguez, Lenin; Plath, Martin; Eifert, Constanze; Lerp, Hannes; Lamboj, Anton; Voelker, Gary; Tobler, Michael

    2013-01-01

    The process of ecological speciation drives the evolution of locally adapted and reproductively isolated populations in response to divergent natural selection. In Southern Mexico, several lineages of the freshwater fish species of the genus Poecilia have independently colonized toxic, hydrogen sulfide-rich springs. Even though ecological speciation processes are increasingly well understood in this system, aligning the taxonomy of these fish with evolutionary processes has lagged behind. While some sulfide spring populations are classified as ecotypes of Poecilia mexicana, others, like P. sulphuraria, have been described as highly endemic species. Our study particularly focused on elucidating the taxonomy of the long described sulfide spring endemic, Poecilia thermalis Steindachner 1863, and investigates if similar evolutionary patterns of phenotypic trait divergence and reproductive isolation are present as observed in other sulfidic species of Poecilia. We applied a geometric morphometric approach to assess body shape similarity to other sulfidic and non-sulfidic fish of the genus Poecilia. We also conducted phylogenetic and population genetic analyses to establish the phylogenetic relationships of P. thermalis and used a population genetic approach to determine levels of gene flow among Poecilia from sulfidic and non-sulfidic sites. Our results indicate that P. thermalis' body shape has evolved in convergence with other sulfide spring populations in the genus. Phylogenetic analyses placed P. thermalis as most closely related to one population of P. sulphuraria, and population genetic analyses demonstrated that P. thermalis is genetically isolated from both P. mexicana ecotypes and P. sulphuraria. Based on these findings, we make taxonomic recommendations for P. thermalis. Overall, our study verifies the role of hydrogen sulfide as a main factor shaping convergent, phenotypic evolution and the emergence of reproductive isolation between Poecilia populations

  18. The Rediscovery of a Long Described Species Reveals Additional Complexity in Speciation Patterns of Poeciliid Fishes in Sulfide Springs

    PubMed Central

    Palacios, Maura; Arias-Rodriguez, Lenin; Plath, Martin; Eifert, Constanze; Lerp, Hannes; Lamboj, Anton; Voelker, Gary; Tobler, Michael

    2013-01-01

    The process of ecological speciation drives the evolution of locally adapted and reproductively isolated populations in response to divergent natural selection. In Southern Mexico, several lineages of the freshwater fish species of the genus Poecilia have independently colonized toxic, hydrogen sulfide-rich springs. Even though ecological speciation processes are increasingly well understood in this system, aligning the taxonomy of these fish with evolutionary processes has lagged behind. While some sulfide spring populations are classified as ecotypes of Poecilia mexicana, others, like P. sulphuraria, have been described as highly endemic species. Our study particularly focused on elucidating the taxonomy of the long described sulfide spring endemic, Poecilia thermalis Steindachner 1863, and investigates if similar evolutionary patterns of phenotypic trait divergence and reproductive isolation are present as observed in other sulfidic species of Poecilia. We applied a geometric morphometric approach to assess body shape similarity to other sulfidic and non-sulfidic fish of the genus Poecilia. We also conducted phylogenetic and population genetic analyses to establish the phylogenetic relationships of P. thermalis and used a population genetic approach to determine levels of gene flow among Poecilia from sulfidic and non-sulfidic sites. Our results indicate that P. thermalis' body shape has evolved in convergence with other sulfide spring populations in the genus. Phylogenetic analyses placed P. thermalis as most closely related to one population of P. sulphuraria, and population genetic analyses demonstrated that P. thermalis is genetically isolated from both P. mexicana ecotypes and P. sulphuraria. Based on these findings, we make taxonomic recommendations for P. thermalis. Overall, our study verifies the role of hydrogen sulfide as a main factor shaping convergent, phenotypic evolution and the emergence of reproductive isolation between Poecilia populations

  19. Gravure-Printed Sol-Gels on Flexible Glass: A Scalable Route to Additively Patterned Transparent Conductors.

    PubMed

    Scheideler, William J; Jang, Jaewon; Ul Karim, Muhammed Ahosan; Kitsomboonloha, Rungrot; Zeumault, Andre; Subramanian, Vivek

    2015-06-17

    Gravure printing is an attractive technique for patterning high-resolution features (<5 μm) at high speeds (>1 m/s), but its electronic applications have largely been limited to depositing nanoparticle inks and polymer solutions on plastic. Here, we extend the scope of gravure to a new class of materials and on to new substrates by developing viscous sol-gel precursors for printing fine lines and films of leading transparent conducting oxides (TCOs) on flexible glass. We explore two strategies for controlling sol-gel rheology: tuning the precursor concentration and tuning the content of viscous stabilizing agents. The sol-gel chemistries studied yield printable inks with viscosities of 20-160 cP. The morphology of printed lines of antimony-doped tin oxide (ATO) and tin-doped indium oxide (ITO) is studied as a function of ink formulation for lines as narrow as 35 μm, showing that concentrated inks form thicker lines with smoother edge morphologies. The electrical and optical properties of printed TCOs are characterized as a function of ink formulation and printed film thickness. XRD studies were also performed to understand the dependence of electrical performance on ink composition. Printed ITO lines and films achieve sheet resistance (Rs) as low as 200 and 100 Ω/□, respectively (ρ≈2×10(-3) Ω-cm) for single layers. Similarly, ATO lines and films have Rs as low as 700 and 400 Ω/□ with ρ≈7×10(-3) Ω-cm. High visible range transparency is observed for ITO (86-88%) and ATO (86-89%). Finally, the influence of moderate bending stress on ATO films is investigated, showing the potential for this work to scale to roll-to-roll (R2R) systems.

  20. Molecular similarity and property similarity.

    PubMed

    Barbosa, Frédérique; Horvath, Dragos

    2004-01-01

    This paper reviews the main efforts undertaken up to date in order to understand, rationalize and apply the similarity principle (similar compounds=>similar properties) as a computational tool in modern drug discovery. The best suited mathematical expression of this classical working hypothesis of medicinal chemistry needs to be carefully chosen (out of the virtually infinite possible implementations in terms of molecular descriptors and molecular similarity metrics), in order to achieve an optimal validation of the hypothesis that molecules that are neighbors in the Structural Space will also display similar properties. This overview will show why no single "absolute" measure of molecular similarity can be conceived, and why molecular similarity scores should be considered tunable tools that need to be adapted to each problem to solve.

  1. Transplacental arsenic plus postnatal 12-O-teradecanoyl phorbol-13-acetate exposures associated with hepatocarcinogenesis induce similar aberrant gene expression patterns in male and female mouse liver

    SciTech Connect

    Liu Jie . E-mail: Liu6@niehs.nih.gov; Xie Yaxiong; Merrick, B. Alex; Shen Jun; Ducharme, Danica M.K.; Collins, Jennifer; Diwan, Bhalchandra A.; Logsdon, Daniel; Waalkes, Michael P.

    2006-06-15

    Our prior work shows that in utero arsenic exposure alone is a complete transplacental carcinogen, producing hepatocellular carcinoma in adult male offspring but not in females. In a follow-up study to potentially promote arsenic-initiated tumors, mice were exposed to arsenic (85 ppm) from gestation day 8 to 18 and then exposed to 12-O-teradecanoyl phorbol-13-acetate (TPA), a well-known tumor promoter after weaning. The dermal application of TPA (2 {mu}g/0.1 ml acetone, twice/week for 21 weeks) after transplacental arsenic did not further increase arsenic-induced liver tumor formation in adult males but significantly increased liver tumor formation in adult females. Thus, for comparison, liver tumors and normal liver samples taken from adult male and female mice at necropsy were analyzed for aberrant gene/protein expression by microarray, real-time RT-PCR and Western blot analysis. Arsenic/TPA treatment resulted in increased expression of {alpha}-fetoprotein, k-ras, c-myc, estrogen receptor-{alpha}, cyclin D1, cdk2na, plasminogen activator inhibitor-1, cytokeratin-8, cytokeratin-18, glutathione S-transferases and insulin-like growth factor binding proteins in liver and liver tumors from both male and female mice. Arsenic/TPA also decreased the expression of BRCA1, betaine-homocysteine methyltransferase, CYP7B1, CYP2F2 and insulin-like growth factor-1 in normal and cancerous livers. Alterations in these gene products were associated with arsenic/TPA-induced liver tumors, regardless of sex. Thus, transplacental arsenic plus postnatal TPA exposure induced similar aberrant gene expression patterns in male and female mouse liver, which are persistent and potentially important to the mechanism of arsenic initiation of hepatocarcinogenesis.

  2. Patterns of Non-adherence to Supplementation with Calcium and Vitamin D in Persistent Postmenopausal Women Are Similar at Start and 1 Year Later: A Qualitative Longitudinal Study

    PubMed Central

    Touskova, Tereza; Vytrisalova, Magda; Palicka, Vladimir; Hendrychova, Tereza; Chen, Yang-Ti; Fuksa, Leos

    2016-01-01

    patterns of non-adherence were very similar at follow-up. Signing of the informed consent seems to act as bias more than regular medical check-up. PMID:27746732

  3. Gene expression suggests double-segmental and single-segmental patterning mechanisms during posterior segment addition in the beetle Tribolium castaneum.

    PubMed

    Janssen, Ralf

    2014-01-01

    In the model arthropod Drosophila, all segments are patterned simultaneously in the blastoderm. In most other arthropods, however, posterior segments are added sequentially from a posterior segment addition zone. Posterior addition of single segments likely represents the ancestral mode of arthropod segmentation, although in Drosophila, segments are patterned in pairs by the pair-rule genes. It has been shown that in the new model insect, the beetle Tribolium, a segmentation clock operates that apparently patterns all segments in pairs as well. Here, I report on the expression of the segment polarity gene H15/midline in Tribolium. In the anterior embryo, segmental stripes of H15 appear in pairs, but in the posterior of the embryo stripes appear in a single-segmental periodicity. This implies that either two completely different segmentation-mechanisms may act in the germ band of Tribolium, that the segmentation clock changes its periodicity during development, or that the speed in which posterior segments are patterned changes. In any case, the data suggest the presence of another (or modified), yet undiscovered, mechanism of posterior segment addition in one of the best-understood arthropod models. The finding of a hitherto unrecognized segmentation mechanism in Tribolium may have major implications for the understanding of the origin of segmentation mechanisms, including the origin of pair rule patterning. It also calls for (re)-investigation of posterior segment addition in Tribolium and other previously studied arthropod models.

  4. Distinct Pattern Separation Related Transfer Functions in Human CA3/Dentate and CA1 Revealed Using High-Resolution fMRI and Variable Mnemonic Similarity

    ERIC Educational Resources Information Center

    Lacy, Joyce W.; Yassa, Michael A.; Stark, Shauna M.; Muftuler, L. Tugan; Stark, Craig E. L.

    2011-01-01

    Producing and maintaining distinct (orthogonal) neural representations for similar events is critical to avoiding interference in long-term memory. Recently, our laboratory provided the first evidence for separation-like signals in the human CA3/dentate. Here, we extended this by parametrically varying the change in input (similarity) while…

  5. In vitro adherence patterns of Shigella serogroups to bovine recto-anal junction squamous epithelial (RSE) cells are similar to those of Escherichia coli O157

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The aim of this study was to determine whether Shigella species, which are human gastrointestinal pathogens, can adhere to cattle recto-anal junction squamous epithelial (RSE) cells using a recently standardized adherence assay, and to compare their adherence patterns to that of Escherichia coli O15...

  6. Cis-transcriptional variation in maize inbred lines B73 and Mo17 leads to additive expression patterns in the F1 hybrid.

    PubMed

    Stupar, Robert M; Springer, Nathan M

    2006-08-01

    Microarray analysis of gene expression patterns in immature ear, seedling, and embryo tissues from the maize inbred lines B73 and Mo17 identified numerous genes with variable expression. Some genes had detectable expression in only one of the two inbreds; most of these genes were detected in the genomic DNA of both inbreds, indicating that the expression differences are likely caused by differential regulation rather than by differences in gene content. Gene expression was also monitored in the reciprocal F1 hybrids B73xMo17 and Mo17xB73. The reciprocal F1 hybrid lines did not display parental effects on gene expression levels. Approximately 80% of the differentially expressed genes displayed additive expression patterns in the hybrids relative to the inbred parents. The approximately 20% of genes that display nonadditive expression patterns tend to be expressed at levels within the parental range, with minimal evidence for novel expression levels greater than the high parent or less than the low parent. Analysis of allele-specific expression patterns in the hybrid suggested that intraspecific variation in gene expression levels is largely attributable to cis-regulatory variation in maize. Collectively, our data suggest that allelic cis-regulatory variation between B73 and Mo17 dictates maintenance of inbred allelic expression levels in the F1 hybrid, resulting in additive expression patterns.

  7. Increased pattern transfer fidelity ZEP 520A during reactive ion etching through chemical modifications by additional dosing of the electron beam resist.

    SciTech Connect

    Czaplewski, D. A.; Ocola, L. E.

    2011-03-01

    This article describes a postdevelopment, additional electron exposure to enhance the etch selectivity and improve pattern transfer fidelity of an electron beam resist, ZEP 520A, through chemical changes of the resist. After the critical features were patterned and developed, the resist was exposed at 5 kV accelerating voltage to a second dose of electrons ranging from 300 to 300,000 {micro}C/cm{sup 2}. The etch rate of the resist decreased by approximately 25% in a CHF{sub 3} and O{sub 2} plasma. More critically, the fidelity of the pattern transfer was improved. Infrared and Raman spectroscopies were used to characterize the resist before and after electron beam exposure for doses up to 3000 {micro}C/cm{sup 2}. The carbonyl bonding in the polymer showed significant changes after electron beam exposure that can be associated with improvement in the etch performance of this resist.

  8. Bile duct carcinoma involving the common channel associated with pancreaticobiliary maljunction shows an extension pattern similar to ductal carcinoma of the pancreas.

    PubMed

    Yoshida, Nao; Esaki, Minoru; Kishi, Yoji; Shimada, Kazuaki; Ojima, Hidenori; Kanai, Yae; Hiraoka, Nobuyoshi

    2013-08-01

    Biliary tract cancer occurs frequently in patients with pancreaticobiliary maljunction (PBM), although no details of its clinicopathological characteristics have been reported. Here we describe a case of bile duct (BD) cancer that developed in association with PBM. This BD cancer involved the common channel, extended to the main pancreatic duct (MPD) via the common channel, and invaded the pancreatic parenchyma, where its growth and spread, and features of its recurrence, were similar to those of ductal carcinoma of the pancreas. We assumed that MPD extension of BD cancer via the common channel was the reason for its deep spread to the pancreas, since BD cancer usually spreads along the BD and rarely reaches the common channel of the ampulla of Vater. During the follow-up of patients with PBM, attention should be paid to involvement of the common channel by BD cancer and also to cancer developing silently in the pancreas after extrahepatic BD resection.

  9. Patterns of some extracellular matrix gene expression are similar in cells from cleft lip-palate patients and in human palatal fibroblasts exposed to diazepam in culture.

    PubMed

    Marinucci, Lorella; Balloni, Stefania; Bodo, Maria; Carinci, Francesco; Pezzetti, Furio; Stabellini, Giordano; Conte, Carmela; Carmela, Conte; Lumare, Eleonora

    2009-03-04

    Prenatal exposure to diazepam, a prototype sedative drug that belongs to Benzodiazepines, can lead to orofacial clefting in human newborns. By using real-time PCR, in the present study we investigated whether diazepam elicits gene expression alterations in extracellular matrix (ECM) components, growth factors and gamma-aminobutyric acid receptor (GABRB3), implicated in the coordinate regulation of palate development. Palate fibroblasts were treated with diazepam (Dz-N fibroblasts) and compared to cleft lip-palate (CLP) fibroblasts obtained from patients with no known exposure to diazepam or other teratogens. Untreated fibroblasts from non-CLP patients were used as control. The results showed significant convergences in gene expression pattern of collagens, fibromodulin, vitronectin, tenascin C, integrins and metalloprotease MMP13 between Dz-N and CLP fibroblasts. Among the growth factors, constitutive Fibroblast Growth Factor 2 (FGF2) was greatly enhanced in Dz-N and CLP fibroblasts and associated with a higher reduction of FGF receptor. Transforming Growth Factor beta 3 (TGFbeta(3)) resulted up-regulated in CLP fibroblasts and decreased in Dz-N fibroblasts. We found phenotypic differences exhibited by Dz-N and CLP fibroblasts in GABRB3 gene regulation, so further studies are necessary to determine whether GABAergic system could be involved in the development of diazepam mediated CLP phenotype. Taken together the results elucidate the molecular mechanisms underlying possible toxicology effects induced by diazepam. Counselling of women on the safety of diazepam exposure is clinically important, also for the forensic consequences.

  10. Does cross-taxon analysis show similarity in diversity patterns between vascular plants and bryophytes? Some answers from a literature review.

    PubMed

    Bagella, Simonetta

    2014-04-01

    The objective of this study was to clarify the taxon surrogacy hypothesis relative to vascular plants and bryophytes. A literature review was conducted to obtain papers that met the following criteria: (i) they examined species richness values; or (ii) they evaluated the species richness within the same study sites, or under the same spatial variation conditions. Twenty-seven papers were accessed. The richness of the two taxa, compared in 32 cases, positively co-varied in about half of the comparisons. The response to the spatial variation in environmental or human-induced factors of the two taxa in terms of species richness was rather variable. Based on current knowledge, the main documented findings regard forest habitats and nival gradients. In forest habitats, co-variation in species richness is likely when similar environments are analysed and seems to be strengthened for boreal forests. Along the nival gradient, a different response in terms of richness of the two taxa suggests that vascular plants cannot be considered good surrogates for bryophytes.

  11. Addition of ammonia or amino acids to a nitrogen-depleted medium affects gene expression patterns in yeast cells during alcoholic fermentation.

    PubMed

    Jiménez-Martí, Elena; del Olmo, Marcel Lí

    2008-03-01

    Yeast cells require nitrogen and are capable of selectively using good nitrogen sources in preference to poor ones by means of the regulatory mechanism known as nitrogen catabolite repression (NCR). Herein, the effect of ammonia or amino acid addition to nitrogen-depleted medium on global yeast expression patterns in yeast cells was studied using alcoholic fermentation as a system. The results indicate that there is a differential reprogramming of the gene expression depending on the nitrogen source added. Ammonia addition resulted in a higher expression of genes involved in amino acids biosynthesis while amino acid addition prepares the cells for protein biosynthesis. Therefore, a high percentage of the genes regulated by the transcription factors involved in the regulation of amino acid biosynthesis are more expressed during the first hours after ammonia addition compared with amino acid addition. The opposite occurs for those genes regulated by the transcription factor Sfp1p, related to ribosome biosynthesis. Although both additions include rich nitrogen sources, most NCR-regulated genes are more expressed after adding ammonia than amino acids. One of the differentially expressed genes, YBR174W, is required for optimal growth in synthetic medium.

  12. Additivity and Auditory Pattern Analysis

    DTIC Science & Technology

    1988-05-01

    individual intensities of the tones in the complex comprised a random sample of size n from one of two log-normal distributions: LOW (MI = 65 dB, al = 5...Recognition. December meeting. Lutfi, R.A. (1988c). "Discrimination of random spectra by normal-hearing listeners," in Abstracts of the l1th...four-tone masking, revisited," J. Acoust. Soc. Am., 80 422-428. Lutfi, R.A. (1988). "Discrimination of random spectra by normal-hearing listeners

  13. a Geometrical Similarity Pattern as AN Experimental Model for Shapes in Architectural Heritage: a Case Study of the Base of the Pillars in the Cathedral of Seville and the Church of Santiago in Jerez, Spain

    NASA Astrophysics Data System (ADS)

    Moyano, J. J.; Barrera, J. A.; Nieto, J. E.; Marín, D.; Antón, D.

    2017-02-01

    This paper proposes a procedure for the search of a geometrical similarity pattern in architectural heritage by means of calculating probability indexes to support hypotheses initially endorsed by documentary sources. The buildings analysed are the Cathedral of Seville and the Church of Santiago, in Jerez, Spain. The 3D models of their selected pillars are obtained by means of Terrestrial Laser Scanning (TLS), Optical Scanning (OS) and photogrammetry through image-based modelling software (SFM-IBM). To this end, a procedure for the comparison of shapes is established. It is based on similarity statistics, the determination of homologous points and the agreement of characteristic sections. Here, two key aspects are considered: on the one hand, the metric standpoint; on the other hand, historical-graphical features of the 3D models: composition, techniques, styles, and historical-graphical documentary sources. Thus, putting aside the mere dimensional analysis, the sections are compared with graphical patterns and models of which the same authorship - stonemasons working in that age - is accurately known. As a result, the outcomes of this research reveal the geometrical similarity between the elements of the pillars of the Cathedral of Seville and the Church of Santiago.

  14. Influence of Al³⁺ addition on the flocculation and sedimentation of activated sludge: comparison of single and multiple dosing patterns.

    PubMed

    Wen, Yue; Zheng, Wanlin; Yang, Yundi; Cao, Asheng; Zhou, Qi

    2015-05-15

    In this study, the flocculation and sedimentation performance of activated sludge (AS) with single and multiple dosing of trivalent aluminum (Al(3+)) were studied. The AS samples were cultivated in sequencing batch reactors at 22 °C. The dosages of Al(3+) were 0.00, 0.125, 0.5, 1.0, and 1.5 meq/L for single dosing, and 0.1 meq/L for multiple dosing. Under single dosing conditions, as Al(3+) dosage increased, the zeta potential, total interaction energy, and effluent turbidity decreased, whereas the sludge volume index (SVI) increased, indicating that single Al(3+) dosing could enhance sludge flocculation, but deteriorate sedimentation. By comparison, adding an equal amount of Al(3+) through multiple dosing achieved a similar reduction in turbidity, but the zeta potential was higher, while the loosely bound extracellular polymeric substances (LB-EPS) content and SVI remarkably declined. Although the difference in the flocculation performances between the two dosing patterns was not significant, the underlying mechanisms were quite distinct: the interaction energy played a more important role under single dosing conditions, whereas multiple dosing was more effective in reducing the EPS content. Multiple dosing, which allows sufficient time for sludge restructuring and floc aggregation, could simultaneously optimize sludge flocculation and sedimentation.

  15. Nutraceutical pill containing berberine versus ezetimibe on plasma lipid pattern in hypercholesterolemic subjects and its additive effect in patients with familial hypercholesterolemia on stable cholesterol-lowering treatment

    PubMed Central

    2012-01-01

    Background Although statins (STs) are drugs of first choice in hypercholesterolemic patients, especially in those at high cardiovascular risk, some of them are intolerant to STs or refuse treatment with these drugs. In view of this, we have evaluated the lipid-lowering effect of a nutraceutical pill containing berberine (BBR) and of ezetimibe, as alternative treatments, in monotherapy or in combination, in 228 subjects with primary hypercholesterolemia (HCH), with history of STs intolerance or refusing STs treatment. In addition, since PCSK9 was found up-regulated by STs dampening their effect through an LDL receptors (LDLRs) degradation, and BBR suppressed PCSK9 expression in cellular studies, we supplemented the stable lipid-lowering therapy of 30 genotype-confirmed Familial Hypercholesterolemia heterozygotes (HeFH) with BBR, searching for a further plasma cholesterol reduction. Plasma lipid pattern was evaluated at baseline and during treatments. Results In HCH subjects the nutraceutical pill resulted more effective than EZE in lowering LDL cholesterol (−31.7% vs −25.4%, P < 0.001) and better tolerated. On treatment, LDL-C level below 3.36 mmol/L (≤130 mg/dl) was observed in 28.9% of subjects treated with the nutraceutical pill and 11.8% of those treated with EZE (P <0.007). In the group treated with EZE the subjects carrying the G allele of the g.1679 C > G silent polymorphism of NPC1L1 gene showed a higher response to EZE than homozygous for the common allele (GG + CG: LDL-C −29.4±5.0%, CC −23.6±6.5%, P <0.001). Combined treatment with these drugs was as effective as STs in moderate doses (LDL cholesterol −37%, triglycerides −23%). In HeFH patients the addition of BBR resulted in LDL cholesterol reductions inversely related to those induced by the stable therapy (r = −0.617, P <0.0001), with mean 10.5% further decrease. Conclusions The alternative treatments tested in our HCH subjects were rather effective and safe. The findings in

  16. Role of inert gas additive on dry etch patterning of InGaP in planar inductively coupled BCl 3 plasmas

    NASA Astrophysics Data System (ADS)

    Lee, J. W.; Lim, W. T.; Baek, I. K.; Yoo, S. R.; Jeon, M. H.; Cho, G. S.; Pearton, S. J.; Abernathy, C. R.

    2004-01-01

    The dry etch characteristics of InGaP in BCl 3 planar inductively coupled plasmas (ICP) with additions of Ar or Ne were determined. The inert gas additive provided enhanced etch rates relative to pure BCl 3 and Ne addition in particular produced much higher etch rates at low ratios of BCl 3 in the mixture. The etched features tended to have sloped sidewalls and much rougher surfaces than for GaAs and AlGaAs etched under the same conditions. The practical effect of the Ar or Ne addition was the ability to operate the ICP source over a somewhat broader range of pressures and still maintain practical etch rates. The use of room temperature BCl 3-based etching in a planar ICP appears feasible for base and emitter mesa applications in InGaP/GaAs heterojunction bipolar transistors.

  17. Predicting spatial similarity of freshwater fish biodiversity

    PubMed Central

    Azaele, Sandro; Muneepeerakul, Rachata; Maritan, Amos; Rinaldo, Andrea; Rodriguez-Iturbe, Ignacio

    2009-01-01

    A major issue in modern ecology is to understand how ecological complexity at broad scales is regulated by mechanisms operating at the organismic level. What specific underlying processes are essential for a macroecological pattern to emerge? Here, we analyze the analytical predictions of a general model suitable for describing the spatial biodiversity similarity in river ecosystems, and benchmark them against the empirical occurrence data of freshwater fish species collected in the Mississippi–Missouri river system. Encapsulating immigration, emigration, and stochastic noise, and without resorting to species abundance data, the model is able to reproduce the observed probability distribution of the Jaccard similarity index at any given distance. In addition to providing an excellent agreement with the empirical data, this approach accounts for heterogeneities of different subbasins, suggesting a strong dependence of biodiversity similarity on their respective climates. Strikingly, the model can also predict the actual probability distribution of the Jaccard similarity index for any distance when considering just a relatively small sample. The proposed framework supports the notion that simplified macroecological models are capable of predicting fundamental patterns—a theme at the heart of modern community ecology. PMID:19359481

  18. The Additive Impact of Group and Individual Publicly Displayed Feedback: Examining Individual Response Patterns and Response Generalization in a Safe-Driving Occupational Intervention

    ERIC Educational Resources Information Center

    Ludwig, Timothy D.; Geller, E. Scott; Clarke, Steven W.

    2010-01-01

    Additive effects of publicly posting individual feedback following group goal-setting and feedback were evaluated. The turn-signal use of pizza deliverers was studied in a multiple baseline design across two pizza stores. After baseline observations, pizza deliverers voted on a group turn-signal goal and then received 4 weeks of group feedback on…

  19. Dendritic amphiphiles as additives for honeycomb-like patterned surfaces by breath figures: role of the molecular characteristics on the pore morphology.

    PubMed

    De León, A S; Malhotra, S; Molina, M; Haag, R; Calderón, M; Rodríguez-Hernández, J; Muñoz-Bonilla, A

    2015-02-15

    The current study presents a library of honeycomb-like patterned surfaces developed from a variety of different water-soluble amphiphilic dendrons. When compared to commercial surfactants, the dendrons produce a wide variety of porous surfaces due to their well-defined branched structure. Different functionalities and generations of dendrons have been studied. A singular hierarchical distribution of the dendrons, forming small nanoparticles (micelles) only at the inner edges of the holes (coffee stain effect) is observed. Once the surfaces are fabricated, these dendrons can be easily recovered via simple aqueous washing. After this treatment, the surfaces exhibit a high hydrophobic character (up to 140°) due to the high porosity. This behavior can be described by the Cassie-Baxter model.

  20. Determination of the Pb, Cr, and Cd distribution patterns with various chlorine additives in the bottom ashes of a low-temperature two-stage fluidized bed incinerator by chemical sequential extraction.

    PubMed

    Peng, Tzu-Huan; Lin, Chiou-Liang; Wey, Ming-Yen

    2015-09-15

    A novel low-temperature two-stage fluidized bed (LTTSFB) incinerator has been successfully developed to control heavy-metal emissions during municipal solid waste (MSW) treatment. However, the characteristics of the residual metal patterns during this process are still unclear. The aim of this study was to investigate the metal patterns in the different partitions of the LTTSFB bottom ash by chemical sequential extraction. Artificial waste was used to simulate the MSW. Different parameters including the first-stage temperature, chloride additives, and operating gas velocity were also considered. Results indicated that during the low-temperature treatment process, a high metal mobility phase exists in the first-stage sand bed. The main patterns of Cd, Pb, and Cr observed were the water-soluble, exchangeable, and residual forms, respectively. With the different Cl additives, the results showed that polyvinyl chloride addition increased metal mobility in the LTTSFB bottom ash, while, sodium chloride addition may have reduced metal mobility due to the formation of eutectic material. The second-stage sand bed was found to have a lower risk of metal leaching. The results also suggested that, the residual ashes produced by the LTTSFB system must be taken into consideration given their high metal mobility.

  1. Biosimilar Insulins: How Similar is Similar?

    PubMed Central

    Heinemann, Lutz; Hompesch, Marcus

    2011-01-01

    Biosimilar insulins (BIs) are viewed as commercially attractive products by a number of companies. In order to obtain approval in the European Union or the United States, where there is not a single BI currently on the market, a manufacturer needs to demonstrate that a given BI has a safety and efficacy profile that is similar to that of the “original” insulin formulation that is already on the market. As trivial as this may appear at first glance, it is not trivial at all for a good number of reasons that will be discussed in this commentary. As with protein manufacturing, modifications in the structure of the insulin molecule can take place (which can have serious consequences for the biological effects induced), so a rigid and careful assessment is absolutely necessary. The example of Marvel's failed application with the European Medicines Agency provides insights into the regulatory and clinical challenges surrounding the matter of BI. Although a challenging BI approval process might be regarded as a hurdle to keep companies out of certain markets, it is fair to say that the potential safety and efficacy issues surrounding BI are substantial and relevant and do warrant a careful and evidence-driven approval process. PMID:21722590

  2. Molecular similarity measures.

    PubMed

    Maggiora, Gerald M; Shanmugasundaram, Veerabahu

    2011-01-01

    Molecular similarity is a pervasive concept in chemistry. It is essential to many aspects of chemical reasoning and analysis and is perhaps the fundamental assumption underlying medicinal chemistry. Dissimilarity, the complement of similarity, also plays a major role in a growing number of applications of molecular diversity in combinatorial chemistry, high-throughput screening, and related fields. How molecular information is represented, called the representation problem, is important to the type of molecular similarity analysis (MSA) that can be carried out in any given situation. In this work, four types of mathematical structure are used to represent molecular information: sets, graphs, vectors, and functions. Molecular similarity is a pairwise relationship that induces structure into sets of molecules, giving rise to the concept of chemical space. Although all three concepts - molecular similarity, molecular representation, and chemical space - are treated in this chapter, the emphasis is on molecular similarity measures. Similarity measures, also called similarity coefficients or indices, are functions that map pairs of compatible molecular representations that are of the same mathematical form into real numbers usually, but not always, lying on the unit interval. This chapter presents a somewhat pedagogical discussion of many types of molecular similarity measures, their strengths and limitations, and their relationship to one another. An expanded account of the material on chemical spaces presented in the first edition of this book is also provided. It includes a discussion of the topography of activity landscapes and the role that activity cliffs in these landscapes play in structure-activity studies.

  3. Molecular similarity measures.

    PubMed

    Maggiora, Gerald M; Shanmugasundaram, Veerabahu

    2004-01-01

    Molecular similarity is a pervasive concept in chemistry. It is essential to many aspects of chemical reasoning and analysis and is perhaps the fundamental assumption underlying medicinal chemistry. Dissimilarity, the complement of similarity, also plays a major role in a growing number of applications of molecular diversity in combinatorial chemistry, high-throughput screening, and related fields. How molecular information is represented, called the representation problem, is important to the type of molecular similarity analysis (MSA) that can be carried out in any given situation. In this work, four types of mathematical structure are used to represent molecular information: sets, graphs, vectors, and functions. Molecular similarity is a pairwise relationship that induces structure into sets of molecules, giving rise to the concept of a chemistry space. Although all three concepts molecular similarity, molecular representation, and chemistry space are treated in this chapter, the emphasis is on molecular similarity measures. Similarity measures, also called similarity coefficients or indices, are functions that map pairs of compatible molecular representations, that is, representations of the same mathematical form, into real numbers usually, but not always, lying on the unit interval. This chapter presents a somewhat pedagogical discussion of many types of molecular similarity measures, their strengths and limitations, and their relationship to one another.

  4. The Gender Similarities Hypothesis

    ERIC Educational Resources Information Center

    Hyde, Janet Shibley

    2005-01-01

    The differences model, which argues that males and females are vastly different psychologically, dominates the popular media. Here, the author advances a very different view, the gender similarities hypothesis, which holds that males and females are similar on most, but not all, psychological variables. Results from a review of 46 meta-analyses…

  5. The gender similarities hypothesis.

    PubMed

    Hyde, Janet Shibley

    2005-09-01

    The differences model, which argues that males and females are vastly different psychologically, dominates the popular media. Here, the author advances a very different view, the gender similarities hypothesis, which holds that males and females are similar on most, but not all, psychological variables. Results from a review of 46 meta-analyses support the gender similarities hypothesis. Gender differences can vary substantially in magnitude at different ages and depend on the context in which measurement occurs. Overinflated claims of gender differences carry substantial costs in areas such as the workplace and relationships.

  6. Possibility of controlling the chemical pattern of He and Ar “guided streamers” by means of N{sub 2} or O{sub 2} additives

    SciTech Connect

    Gazeli, K.; Svarnas, P. E-mail: franck.clement@univ-pau.fr; Held, B.; Clément, F. E-mail: franck.clement@univ-pau.fr; Marlin, L.

    2015-03-07

    Plasma chemistry at atmospheric pressure and low temperature has met an increased interest due to the effective production of reactive species (mainly reactive nitrogen species and reactive oxygen species) which are demanded in many applications like in biomedicine. Τhe generation of such emissive reactive species is herein studied. A single parameter, i.e., the gas composition, is tuned and abundant chemical species are obtained in a quite controllable manner. The system refers to a small dielectric barrier discharge based reactor fed with He–N{sub 2}/O{sub 2} or Ar–N{sub 2}/O{sub 2} gases, which provides plasma in the form of “guided streamers.” The plasma is sustained by positive high voltage pulses, and the emissive transitions versus the gas composition is determined by UV-VIS optical emission spectroscopy. The relative intensities of emissive species are recorded in the ambient air where the streamers propagate. The evolution of dominant species as a function of the gas composition is mapped, and optimal conditions in terms of species production are clearly revealed. The results show that additives do not necessarily enhance the density of all species, implying the need for plasma chemistry optimization in respect to every application. The study is extended inside the reactor, supporting the above statements. Finally, the rotational and vibrational distributions of critical probe molecules are recorded, testing the dependence of the gas temperature and energy transfer, respectively, on the gas composition.

  7. Food additives

    PubMed Central

    Spencer, Michael

    1974-01-01

    Food additives are discussed from the food technology point of view. The reasons for their use are summarized: (1) to protect food from chemical and microbiological attack; (2) to even out seasonal supplies; (3) to improve their eating quality; (4) to improve their nutritional value. The various types of food additives are considered, e.g. colours, flavours, emulsifiers, bread and flour additives, preservatives, and nutritional additives. The paper concludes with consideration of those circumstances in which the use of additives is (a) justified and (b) unjustified. PMID:4467857

  8. The Qualitative Similarity Hypothesis

    ERIC Educational Resources Information Center

    Paul, Peter V.; Lee, Chongmin

    2010-01-01

    Evidence is presented for the qualitative similarity hypothesis (QSH) with respect to children and adolescents who are d/Deaf or hard of hearing. The primary focus is on the development of English language and literacy skills, and some information is provided on the acquisition of English as a second language. The QSH is briefly discussed within…

  9. Quantifying Similarity in Seismic Polarizations

    NASA Astrophysics Data System (ADS)

    Eaton, D. W. S.; Jones, J. P.; Caffagni, E.

    2015-12-01

    Measuring similarity in seismic attributes can help identify tremor, low S/N signals, and converted or reflected phases, in addition to diagnosing site noise and sensor misalignment in arrays. Polarization analysis is a widely accepted method for studying the orientation and directional characteristics of seismic phases via. computed attributes, but similarity is ordinarily discussed using qualitative comparisons with reference values. Here we introduce a technique for quantitative polarization similarity that uses weighted histograms computed in short, overlapping time windows, drawing on methods adapted from the image processing and computer vision literature. Our method accounts for ambiguity in azimuth and incidence angle and variations in signal-to-noise (S/N) ratio. Using records of the Mw=8.3 Sea of Okhotsk earthquake from CNSN broadband sensors in British Columbia and Yukon Territory, Canada, and vertical borehole array data from a monitoring experiment at Hoadley gas field, central Alberta, Canada, we demonstrate that our method is robust to station spacing. Discrete wavelet analysis extends polarization similarity to the time-frequency domain in a straightforward way. Because histogram distance metrics are bounded by [0 1], clustering allows empirical time-frequency separation of seismic phase arrivals on single-station three-component records. Array processing for automatic seismic phase classification may be possible using subspace clustering of polarization similarity, but efficient algorithms are required to reduce the dimensionality.

  10. Food additives

    MedlinePlus

    ... or natural. Natural food additives include: Herbs or spices to add flavor to foods Vinegar for pickling ... Certain colors improve the appearance of foods. Many spices, as well as natural and man-made flavors, ...

  11. Similar enzymes, different structures

    PubMed Central

    Tarasev, Michael; Kaddis, Catherine S.; Yin, Sheng; Loo, Joseph A.; Burgner, John; Ballou, David P.

    2007-01-01

    Phthalate dioxygenase (PDO) is a member of a class of bacterial oxygenases that contain both Rieske [2Fe-2S] and Fe(II) mononuclear centers. Recent crystal structures of several Rieske dioxygenases showed that they exist as α3β3 multimers with subunits arranged head-to-tail in α and β stacked planar consists of only α-subunits, remains to be solved. Although similar to other Rieske dioxygenases in many aspects, PDO was shown to differ in the mechanism of catalysis. Gel filtration and analytical centrifugation experiments, supplemented with mass spectrometric analysis (both ESI-MS and ESI-GEMMA), in this work showed a hexameric arrangement of subunits in the PDO multimer. Our proposed model for the subunit arrangement in PDO postulates two α3 planar rings one on top the other, similar to the α3β3 arrangement in other Rieske dioxygenases. Unlike other Rieske dioxygenases, this arrangement brings two Rieske and two mononuclear centers, all on separate subunits, into proximity, allowing their cooperation for catalysis. Potential reasons necessitating this unusual structural arrangement are discussed. PMID:17764654

  12. Similarity transformed semiclassical dynamics

    NASA Astrophysics Data System (ADS)

    Van Voorhis, Troy; Heller, Eric J.

    2003-12-01

    In this article, we employ a recently discovered criterion for selecting important contributions to the semiclassical coherent state propagator [T. Van Voorhis and E. J. Heller, Phys. Rev. A 66, 050501 (2002)] to study the dynamics of many dimensional problems. We show that the dynamics are governed by a similarity transformed version of the standard classical Hamiltonian. In this light, our selection criterion amounts to using trajectories generated with the untransformed Hamiltonian as approximate initial conditions for the transformed boundary value problem. We apply the new selection scheme to some multidimensional Henon-Heiles problems and compare our results to those obtained with the more sophisticated Herman-Kluk approach. We find that the present technique gives near-quantitative agreement with the the standard results, but that the amount of computational effort is less than Herman-Kluk requires even when sophisticated integral smoothing techniques are employed in the latter.

  13. Does Bienertia cycloptera with the single-cell system of C(4) photosynthesis exhibit a seasonal pattern of delta (13)C values in nature similar to co-existing C (4) Chenopodiaceae having the dual-cell (Kranz) system?

    PubMed

    Akhani, Hossein; Lara, María Valeria; Ghasemkhani, Maryam; Ziegler, Hubert; Edwards, Gerald E

    2009-01-01

    Family Chenopodiaceae is an intriguing lineage, having the largest number of C(4) species among dicots, including a number of anatomical variants of Kranz anatomy and three single-cell C(4) functioning species. In some previous studies, during the culture of Bienertia cycloptera Bunge ex Boiss., carbon isotope values (delta(13)C values) of leaves deviated from C(4) to C(3)-C(4) intermediate type, raising questions as to its mode of photosynthesis during growth in natural environments. This species usually co-occurs with several Kranz type C(4) annuals. The development of B. cycloptera morphologically and delta(13)C values derived from plant samples (cotyledons, leaves, bracts, shoots) were analyzed over a complete growing season in a salt flat in north central Iran, along with eight Kranz type C(4) species and one C(3) species. For a number of species, plants were greenhouse-grown from seeds collected from the site, in order to examine leaf anatomy and C(4) biochemical subtype. Among the nine C(4) species, the cotyledons of B. cycloptera, and of the Suaeda spp. have the same respective forms of C(4) anatomy occurring in leaves, while cotyledons of members of tribe Caroxyloneae lack Kranz anatomy, which is reflected in the delta(13)C values found in plants grown in the natural habitat. The nine C(4) species had average seasonal delta(13)C values of -13.9 per thousand (with a range between species from -11.3 to -15.9 per thousand). The measurements of delta(13)C values over a complete growing season show that B. cycloptera performs C(4) photosynthesis during its life cycle in nature, similar to Kranz type species, with a seasonal average delta(13)C value of -15.2 per thousand.

  14. Potlining Additives

    SciTech Connect

    Rudolf Keller

    2004-08-10

    In this project, a concept to improve the performance of aluminum production cells by introducing potlining additives was examined and tested. Boron oxide was added to cathode blocks, and titanium was dissolved in the metal pool; this resulted in the formation of titanium diboride and caused the molten aluminum to wet the carbonaceous cathode surface. Such wetting reportedly leads to operational improvements and extended cell life. In addition, boron oxide suppresses cyanide formation. This final report presents and discusses the results of this project. Substantial economic benefits for the practical implementation of the technology are projected, especially for modern cells with graphitized blocks. For example, with an energy savings of about 5% and an increase in pot life from 1500 to 2500 days, a cost savings of $ 0.023 per pound of aluminum produced is projected for a 200 kA pot.

  15. Phosphazene additives

    DOEpatents

    Harrup, Mason K; Rollins, Harry W

    2013-11-26

    An additive comprising a phosphazene compound that has at least two reactive functional groups and at least one capping functional group bonded to phosphorus atoms of the phosphazene compound. One of the at least two reactive functional groups is configured to react with cellulose and the other of the at least two reactive functional groups is configured to react with a resin, such as an amine resin of a polycarboxylic acid resin. The at least one capping functional group is selected from the group consisting of a short chain ether group, an alkoxy group, or an aryloxy group. Also disclosed are an additive-resin admixture, a method of treating a wood product, and a wood product.

  16. Representational Similarity of Body Parts in Human Occipitotemporal Cortex.

    PubMed

    Bracci, Stefania; Caramazza, Alfonso; Peelen, Marius V

    2015-09-23

    Regions in human lateral and ventral occipitotemporal cortices (OTC) respond selectively to pictures of the human body and its parts. What are the organizational principles underlying body part responses in these regions? Here we used representational similarity analysis (RSA) of fMRI data to test multiple possible organizational principles: shape similarity, physical proximity, cortical homunculus proximity, and semantic similarity. Participants viewed pictures of whole persons, chairs, and eight body parts (hands, arms, legs, feet, chests, waists, upper faces, and lower faces). The similarity of multivoxel activity patterns for all body part pairs was established in whole person-selective OTC regions. The resulting neural similarity matrices were then compared with similarity matrices capturing the hypothesized organizational principles. Results showed that the semantic similarity model best captured the neural similarity of body parts in lateral and ventral OTC, which followed an organization in three clusters: (1) body parts used as action effectors (hands, feet, arms, and legs), (2) noneffector body parts (chests and waists), and (3) face parts (upper and lower faces). Whole-brain RSA revealed, in addition to OTC, regions in parietal and frontal cortex in which neural similarity was related to semantic similarity. In contrast, neural similarity in occipital cortex was best predicted by shape similarity models. We suggest that the semantic organization of body parts in high-level visual cortex relates to the different functions associated with the three body part clusters, reflecting the unique processing and connectivity demands associated with the different types of information (e.g., action, social) different body parts (e.g., limbs, faces) convey. Significance statement: While the organization of body part representations in motor and somatosensory cortices has been well characterized, the principles underlying body part representations in visual cortex

  17. On distributional assumptions and whitened cosine similarities.

    PubMed

    Loog, Marco

    2008-06-01

    Recently, an interpretation of the whitened cosine similarity measure as a Bayes decision rule was proposed (C. Liu, "The Bayes Decision Rule Induced Similarity Measures,'' IEEE Trans. Pattern Analysis and Machine Intelligence, vol. 29, no. 6, pp. 1086-1090, June 2007. This communication makes the observation that some of the distributional assumptions made to derive this measure are very restrictive and, considered simultaneously, even inconsistent.

  18. Similar pattern of chemokines after acute viral and bacterial infection.

    PubMed

    Vyas, Ashish Kumar

    2017-01-27

    Read with great interest the article by Cavalcanti et al (1). Which describes the levels of chemokine such as MCP-1, RANETS, MIG and IP-10 in children with sepsis community acquired pneumonia and skin abscess. Author has found increased levels of RANETS in all infections mentioned above. Interestingly IP-10 was significantly increased in sepsis groups with low levels of MCP1. This article is protected by copyright. All rights reserved.

  19. Gait Signal Analysis with Similarity Measure

    PubMed Central

    Shin, Seungsoo

    2014-01-01

    Human gait decision was carried out with the help of similarity measure design. Gait signal was selected through hardware implementation including all in one sensor, control unit, and notebook with connector. Each gait signal was considered as high dimensional data. Therefore, high dimensional data analysis was considered via heuristic technique such as the similarity measure. Each human pattern such as walking, sitting, standing, and stepping up was obtained through experiment. By the results of the analysis, we also identified the overlapped and nonoverlapped data relation, and similarity measure analysis was also illustrated, and comparison with conventional similarity measure was also carried out. Hence, nonoverlapped data similarity analysis provided the clue to solve the similarity of high dimensional data. Considered high dimensional data analysis was designed with consideration of neighborhood information. Proposed similarity measure was applied to identify the behavior patterns of different persons, and different behaviours of the same person. Obtained analysis can be extended to organize health monitoring system for specially elderly persons. PMID:25110724

  20. Methods to Calculate Spectrum Similarity.

    PubMed

    Yilmaz, Şule; Vandermarliere, Elien; Martens, Lennart

    2017-01-01

    Scoring functions that assess spectrum similarity play a crucial role in many computational mass spectrometry algorithms. These functions are used to compare an experimentally acquired fragmentation (MS/MS) spectrum against two different types of target MS/MS spectra: either against a theoretical MS/MS spectrum derived from a peptide from a sequence database, or against another, previously acquired MS/MS spectrum. The former is typically encountered in database searching, while the latter is used in spectrum clustering and spectral library searching. The comparison between acquired versus theoretical MS/MS spectra is most commonly performed using cross-correlations or probability derived scoring functions, while the comparison of two acquired MS/MS spectra typically makes use of a normalized dot product, especially in spectrum library search algorithms. In addition to these scoring functions, Pearson's or Spearman's correlation coefficients, mean squared error, or median absolute deviation scores can also be used for the same purpose. Here, we describe and evaluate these scoring functions with regards to their ability to assess spectrum similarity for theoretical versus acquired, and acquired versus acquired spectra.

  1. Self-similar dynamics of bacterial chemotaxis

    NASA Astrophysics Data System (ADS)

    Ngamsaad, Waipot; Khompurngson, Kannika

    2012-12-01

    Colonies of bacteria grown on thin agar plate exhibit fractal patterns as a result of adaptation to their environments. The bacterial colony pattern formation is regulated crucially by chemotaxis, the movement of cells along a chemical concentration gradient. Here, the dynamics of pattern formation in a bacterial colony is investigated theoretically through a continuum model that considers chemotaxis. In the case of the gradient sensed by the bacterium is nearly uniform, the bacterial colony patterns are self-similar, which means they look the same at every scale. The scaling law of the bacterial colony growth has been revealed explicitly. Chemotaxis biases the movement of the bacterial population in colony to trend toward the chemical attractant. Moreover, the bacterial colonies evolve for a long time as the traveling wave with a sharp front.

  2. Phylogenetically related and ecologically similar carnivores harbour similar parasite assemblages.

    PubMed

    Huang, Shan; Bininda-Emonds, Olaf R P; Stephens, Patrick R; Gittleman, John L; Altizer, Sonia

    2014-05-01

    Most parasites infect multiple hosts, but what factors determine the range of hosts a given parasite can infect? Understanding the broad scale determinants of parasite distributions across host lineages is important for predicting pathogen emergence in new hosts and for estimating pathogen diversity in understudied host species. In this study, we used a new data set on 793 parasite species reported from free-ranging populations of 64 carnivore species to examine the factors that influence parasite sharing between host species. Our results showed that parasites are more commonly shared between phylogenetically related host species pairs. Additionally, host species with higher similarity in biological traits and greater geographic range overlap were also more likely to share parasite species. Of three measures of phylogenetic relatedness considered here, the number divergence events that separated host species pairs most strongly influenced the likelihood of parasite sharing. We also showed that viruses and helminths tend to infect carnivore hosts within more restricted phylogenetic ranges than expected by chance. Overall, our results underscore the importance of host evolutionary history in determining parasite host range, even when simultaneously considering other factors such as host ecology and geographic distribution.

  3. Self-similarity in Laplacian growth

    SciTech Connect

    Mineev-weinstein, Mark; Zabrodin, Anton; Abanov, Artem

    2008-01-01

    We consider Laplacian Growth of self-similar domains in different geometries. Self-similarity determines the analytic structure of the Schwarz function of the moving boundary. The knowledge of this analytic structure allows us to derive the integral equation for the conformal map. It is shown that solutions to the integral equation obey also a second-order differential equation which is the 1D Schroedinger equation with the sinh{sup -2}-potential. The solutions, which are expressed through the Gauss hypergeometric function, characterize the geometry of self-similar patterns in a wedge. We also find the potential for the Coulomb gas representation of the self-similar Laplacian growth in a wedge and calculate the corresponding free energy.

  4. Self-similarity in active colloid motion

    NASA Astrophysics Data System (ADS)

    Constant, Colin; Sukhov, Sergey; Dogariu, Aristide

    The self-similarity of displacements among randomly evolving systems has been used to describe the foraging patterns of animals and predict the growth of financial systems. At micron scales, the motion of colloidal particles can be analyzed by sampling their spatial displacement in time. For self-similar systems in equilibrium, the mean squared displacement increases linearly in time. However, external forces can take the system out of equilibrium, creating active colloidal systems, and making this evolution more complex. A moment scaling spectrum of the distribution of particle displacements quantifies the degree of self-similarity in the colloid motion. We will demonstrate that, by varying the temporal and spatial characteristics of the external forces, one can control the degree of self-similarity in active colloid motion.

  5. Relations between premise similarity and inductive strength.

    PubMed

    Heit, Evan; Feeney, Aidan

    2005-04-01

    According to the diversity principle, diverse evidence is strong evidence. There has been considerable evidence that people respect this principle in inductive reasoning. However, exceptions may be particularly informative. Medin, Coley, Storms, and Hayes (2003) introduced a relevance theory of inductive reasoning and used this theory to predict exceptions, including the nondiversity-by-property-reinforcement effect. A new experiment in which this phenomenon was investigated is reported here. Subjects made inductive strength judgments and similarity judgments for stimuli from Medin et al. (2003). The inductive strength judgments showed the same pattern as that in Medin et al. (2003); however, the similarity judgments suggested that the pattern should be interpreted as a diversity effect, rather than as a nondiversity effect. It is concluded that the evidence regarding the predicted nondiversity-by-property-reinforcement effect does not give distinctive support for relevance theory, although this theory does address other results.

  6. Developing networks play a similar melody.

    PubMed

    Ben-Ari, Y

    2001-06-01

    During development, when synapses start to be established, a primitive form of network-driven activity provides most of the synaptic activity. This pattern enables a high degree of synchrony in immature neurons in spite of the small number of functional synapses and could participate in activity-dependent growth and synapse formation. Relying on the giant depolarizing potentials that provide most of the synaptic activity in the developing hippocampus, this article reviews the common properties and generating mechanisms of these patterns, and particularly the role of the early depolarizing action of GABA(A) and glycine receptors and the sequential expression of GABA and glutamate synapses. Patterns similar to giant depolarizing potentials have been observed in a wide range of structures and species suggesting that there is a temporal template throughout evolution that constitutes an essential step in the formation of functional networks.

  7. Activity-relevant similarity values for fingerprints and implications for similarity searching

    PubMed Central

    Jasial, Swarit; Hu, Ye; Vogt, Martin; Bajorath, Jürgen

    2016-01-01

    A largely unsolved problem in chemoinformatics is the issue of how calculated compound similarity relates to activity similarity, which is central to many applications. In general, activity relationships are predicted from calculated similarity values. However, there is no solid scientific foundation to bridge between calculated molecular and observed activity similarity. Accordingly, the success rate of identifying new active compounds by similarity searching is limited. Although various attempts have been made to establish relationships between calculated fingerprint similarity values and biological activities, none of these has yielded generally applicable rules for similarity searching. In this study, we have addressed the question of molecular versus activity similarity in a more fundamental way. First, we have evaluated if activity-relevant similarity value ranges could in principle be identified for standard fingerprints and distinguished from similarity resulting from random compound comparisons. Then, we have analyzed if activity-relevant similarity values could be used to guide typical similarity search calculations aiming to identify active compounds in databases. It was found that activity-relevant similarity values can be identified as a characteristic feature of fingerprints. However, it was also shown that such values cannot be reliably used as thresholds for practical similarity search calculations. In addition, the analysis presented herein helped to rationalize differences in fingerprint search performance. PMID:27127620

  8. Detecting Distortion: Bridging Visual and Quantitative Reasoning on Similarity Tasks

    ERIC Educational Resources Information Center

    Cox, Dana C.; Lo, Jane-Jane

    2014-01-01

    This study is focused on identifying and describing the reasoning patterns of middle grade students when examining potentially similar figures. Described here is a framework that includes 11 strategies that students used during clinical interview to differentiate similar and non-similar figures. Two factors were found to influence the strategies…

  9. Similarity Learning of Manifold Data.

    PubMed

    Chen, Si-Bao; Ding, Chris H Q; Luo, Bin

    2015-09-01

    Without constructing adjacency graph for neighborhood, we propose a method to learn similarity among sample points of manifold in Laplacian embedding (LE) based on adding constraints of linear reconstruction and least absolute shrinkage and selection operator type minimization. Two algorithms and corresponding analyses are presented to learn similarity for mix-signed and nonnegative data respectively. The similarity learning method is further extended to kernel spaces. The experiments on both synthetic and real world benchmark data sets demonstrate that the proposed LE with new similarity has better visualization and achieves higher accuracy in classification.

  10. Stability of similarity measurements for bipartite networks

    NASA Astrophysics Data System (ADS)

    Liu, Jian-Guo; Hou, Lei; Pan, Xue; Guo, Qiang; Zhou, Tao

    2016-01-01

    Similarity is a fundamental measure in network analyses and machine learning algorithms, with wide applications ranging from personalized recommendation to socio-economic dynamics. We argue that an effective similarity measurement should guarantee the stability even under some information loss. With six bipartite networks, we investigate the stabilities of fifteen similarity measurements by comparing the similarity matrixes of two data samples which are randomly divided from original data sets. Results show that, the fifteen measurements can be well classified into three clusters according to their stabilities, and measurements in the same cluster have similar mathematical definitions. In addition, we develop a top-n-stability method for personalized recommendation, and find that the unstable similarities would recommend false information to users, and the performance of recommendation would be largely improved by using stable similarity measurements. This work provides a novel dimension to analyze and evaluate similarity measurements, which can further find applications in link prediction, personalized recommendation, clustering algorithms, community detection and so on.

  11. Stability of similarity measurements for bipartite networks

    PubMed Central

    Liu, Jian-Guo; Hou, Lei; Pan, Xue; Guo, Qiang; Zhou, Tao

    2016-01-01

    Similarity is a fundamental measure in network analyses and machine learning algorithms, with wide applications ranging from personalized recommendation to socio-economic dynamics. We argue that an effective similarity measurement should guarantee the stability even under some information loss. With six bipartite networks, we investigate the stabilities of fifteen similarity measurements by comparing the similarity matrixes of two data samples which are randomly divided from original data sets. Results show that, the fifteen measurements can be well classified into three clusters according to their stabilities, and measurements in the same cluster have similar mathematical definitions. In addition, we develop a top-n-stability method for personalized recommendation, and find that the unstable similarities would recommend false information to users, and the performance of recommendation would be largely improved by using stable similarity measurements. This work provides a novel dimension to analyze and evaluate similarity measurements, which can further find applications in link prediction, personalized recommendation, clustering algorithms, community detection and so on. PMID:26725688

  12. Stability of similarity measurements for bipartite networks.

    PubMed

    Liu, Jian-Guo; Hou, Lei; Pan, Xue; Guo, Qiang; Zhou, Tao

    2016-01-04

    Similarity is a fundamental measure in network analyses and machine learning algorithms, with wide applications ranging from personalized recommendation to socio-economic dynamics. We argue that an effective similarity measurement should guarantee the stability even under some information loss. With six bipartite networks, we investigate the stabilities of fifteen similarity measurements by comparing the similarity matrixes of two data samples which are randomly divided from original data sets. Results show that, the fifteen measurements can be well classified into three clusters according to their stabilities, and measurements in the same cluster have similar mathematical definitions. In addition, we develop a top-n-stability method for personalized recommendation, and find that the unstable similarities would recommend false information to users, and the performance of recommendation would be largely improved by using stable similarity measurements. This work provides a novel dimension to analyze and evaluate similarity measurements, which can further find applications in link prediction, personalized recommendation, clustering algorithms, community detection and so on.

  13. Additive manufacturing of polymer-derived ceramics

    NASA Astrophysics Data System (ADS)

    Eckel, Zak C.; Zhou, Chaoyin; Martin, John H.; Jacobsen, Alan J.; Carter, William B.; Schaedler, Tobias A.

    2016-01-01

    The extremely high melting point of many ceramics adds challenges to additive manufacturing as compared with metals and polymers. Because ceramics cannot be cast or machined easily, three-dimensional (3D) printing enables a big leap in geometrical flexibility. We report preceramic monomers that are cured with ultraviolet light in a stereolithography 3D printer or through a patterned mask, forming 3D polymer structures that can have complex shape and cellular architecture. These polymer structures can be pyrolyzed to a ceramic with uniform shrinkage and virtually no porosity. Silicon oxycarbide microlattice and honeycomb cellular materials fabricated with this approach exhibit higher strength than ceramic foams of similar density. Additive manufacturing of such materials is of interest for propulsion components, thermal protection systems, porous burners, microelectromechanical systems, and electronic device packaging.

  14. Additive manufacturing of polymer-derived ceramics.

    PubMed

    Eckel, Zak C; Zhou, Chaoyin; Martin, John H; Jacobsen, Alan J; Carter, William B; Schaedler, Tobias A

    2016-01-01

    The extremely high melting point of many ceramics adds challenges to additive manufacturing as compared with metals and polymers. Because ceramics cannot be cast or machined easily, three-dimensional (3D) printing enables a big leap in geometrical flexibility. We report preceramic monomers that are cured with ultraviolet light in a stereolithography 3D printer or through a patterned mask, forming 3D polymer structures that can have complex shape and cellular architecture. These polymer structures can be pyrolyzed to a ceramic with uniform shrinkage and virtually no porosity. Silicon oxycarbide microlattice and honeycomb cellular materials fabricated with this approach exhibit higher strength than ceramic foams of similar density. Additive manufacturing of such materials is of interest for propulsion components, thermal protection systems, porous burners, microelectromechanical systems, and electronic device packaging.

  15. Discuss Similarity Using Visual Intuition

    ERIC Educational Resources Information Center

    Cox, Dana C.; Lo, Jane-Jane

    2012-01-01

    The change in size from a smaller shape to a larger similar shape (or vice versa) is created through continuous proportional stretching or shrinking in every direction. Students cannot solve similarity tasks simply by iterating or partitioning a composed unit, strategies typically used on numerical proportional tasks. The transition to thinking…

  16. Dynamic similarity in erosional processes

    USGS Publications Warehouse

    Scheidegger, A.E.

    1963-01-01

    A study is made of the dynamic similarity conditions obtaining in a variety of erosional processes. The pertinent equations for each type of process are written in dimensionless form; the similarity conditions can then easily be deduced. The processes treated are: raindrop action, slope evolution and river erosion. ?? 1963 Istituto Geofisico Italiano.

  17. Towards personalized medicine: leveraging patient similarity and drug similarity analytics.

    PubMed

    Zhang, Ping; Wang, Fei; Hu, Jianying; Sorrentino, Robert

    2014-01-01

    The rapid adoption of electronic health records (EHR) provides a comprehensive source for exploratory and predictive analytic to support clinical decision-making. In this paper, we investigate how to utilize EHR to tailor treatments to individual patients based on their likelihood to respond to a therapy. We construct a heterogeneous graph which includes two domains (patients and drugs) and encodes three relationships (patient similarity, drug similarity, and patient-drug prior associations). We describe a novel approach for performing a label propagation procedure to spread the label information representing the effectiveness of different drugs for different patients over this heterogeneous graph. The proposed method has been applied on a real-world EHR dataset to help identify personalized treatments for hypercholesterolemia. The experimental results demonstrate the effectiveness of the approach and suggest that the combination of appropriate patient similarity and drug similarity analytics could lead to actionable insights for personalized medicine. Particularly, by leveraging drug similarity in combination with patient similarity, our method could perform well even on new or rarely used drugs for which there are few records of known past performance.

  18. Patterns of Broken Patterns

    NASA Astrophysics Data System (ADS)

    Field, R. W.; Park, G. B.; Changala, P. B.; Baraban, J. H.; Stanton, J. F.; Merer, A. J.

    2013-06-01

    Spectroscopy - it is all about patterns. Some patterns look so indescribably complicated that, unlike pornography, you do not know one when you see one. It is tempting to say that, at high vibrational excitation, interactions among normal mode basis states are so strong and widespread that all patterns are obliterated. But this is not true. When normal mode frequencies are in near integer multiple ratios, polyads emerge. A polyad is a robust pattern often comprising many vibrational eigenstates. Each such pattern might span many hundreds of cm^{-1}, and it is inevitable that several unrelated polyad patterns overlap. When polyads overlap, it might seem impossible to disentangle them. However, the key to disentanglement is that polyads come in families in which successive generations are related by harmonic oscillator matrix element selection and scaling rules. Families of polyads are described by families of scaling-based effective Hamiltonian matrices, {H}^{{eff}}. No matter how complex and overlapped, the polyad {H}^{{eff}} serves as a magic decoder for picking out the polyad pattern. Sometimes the polyad patterns are systematically broken (a meta-pattern), owing to proximity to an isomerization barrier, as occurs in highly excited bending levels of the S_{1} state of HCCH, which encode the trans-cis minimum energy isomerization path. Quantum Chemists often dismiss {H}^{{eff}} models, precisely because they are models that do not express the full dimensionality of the complete Hamiltonian. But an {H}^{{eff}} explains rather than describes. Shunning {H}^{{eff}}s is like throwing out the baby with the bath water. Don't do it!

  19. SlideSort: all pairs similarity search for short reads

    PubMed Central

    Shimizu, Kana; Tsuda, Koji

    2011-01-01

    Motivation: Recent progress in DNA sequencing technologies calls for fast and accurate algorithms that can evaluate sequence similarity for a huge amount of short reads. Searching similar pairs from a string pool is a fundamental process of de novo genome assembly, genome-wide alignment and other important analyses. Results: In this study, we designed and implemented an exact algorithm SlideSort that finds all similar pairs from a string pool in terms of edit distance. Using an efficient pattern growth algorithm, SlideSort discovers chains of common k-mers to narrow down the search. Compared to existing methods based on single k-mers, our method is more effective in reducing the number of edit distance calculations. In comparison to backtracking methods such as BWA, our method is much faster in finding remote matches, scaling easily to tens of millions of sequences. Our software has an additional function of single link clustering, which is useful in summarizing short reads for further processing. Availability: Executable binary files and C++ libraries are available at http://www.cbrc.jp/~shimizu/slidesort/ for Linux and Windows. Contact: slidesort@m.aist.go.jp; shimizu-kana@aist.go.jp Supplementary information: Supplementary data are available at Bioinformatics online. PMID:21148542

  20. Renewing the respect for similarity.

    PubMed

    Edelman, Shimon; Shahbazi, Reza

    2012-01-01

    In psychology, the concept of similarity has traditionally evoked a mixture of respect, stemming from its ubiquity and intuitive appeal, and concern, due to its dependence on the framing of the problem at hand and on its context. We argue for a renewed focus on similarity as an explanatory concept, by surveying established results and new developments in the theory and methods of similarity-preserving associative lookup and dimensionality reduction-critical components of many cognitive functions, as well as of intelligent data management in computer vision. We focus in particular on the growing family of algorithms that support associative memory by performing hashing that respects local similarity, and on the uses of similarity in representing structured objects and scenes. Insofar as these similarity-based ideas and methods are useful in cognitive modeling and in AI applications, they should be included in the core conceptual toolkit of computational neuroscience. In support of this stance, the present paper (1) offers a discussion of conceptual, mathematical, computational, and empirical aspects of similarity, as applied to the problems of visual object and scene representation, recognition, and interpretation, (2) mentions some key computational problems arising in attempts to put similarity to use, along with their possible solutions, (3) briefly states a previously developed similarity-based framework for visual object representation, the Chorus of Prototypes, along with the empirical support it enjoys, (4) presents new mathematical insights into the effectiveness of this framework, derived from its relationship to locality-sensitive hashing (LSH) and to concomitant statistics, (5) introduces a new model, the Chorus of Relational Descriptors (ChoRD), that extends this framework to scene representation and interpretation, (6) describes its implementation and testing, and finally (7) suggests possible directions in which the present research program can be

  1. Renewing the respect for similarity

    PubMed Central

    Edelman, Shimon; Shahbazi, Reza

    2012-01-01

    In psychology, the concept of similarity has traditionally evoked a mixture of respect, stemming from its ubiquity and intuitive appeal, and concern, due to its dependence on the framing of the problem at hand and on its context. We argue for a renewed focus on similarity as an explanatory concept, by surveying established results and new developments in the theory and methods of similarity-preserving associative lookup and dimensionality reduction—critical components of many cognitive functions, as well as of intelligent data management in computer vision. We focus in particular on the growing family of algorithms that support associative memory by performing hashing that respects local similarity, and on the uses of similarity in representing structured objects and scenes. Insofar as these similarity-based ideas and methods are useful in cognitive modeling and in AI applications, they should be included in the core conceptual toolkit of computational neuroscience. In support of this stance, the present paper (1) offers a discussion of conceptual, mathematical, computational, and empirical aspects of similarity, as applied to the problems of visual object and scene representation, recognition, and interpretation, (2) mentions some key computational problems arising in attempts to put similarity to use, along with their possible solutions, (3) briefly states a previously developed similarity-based framework for visual object representation, the Chorus of Prototypes, along with the empirical support it enjoys, (4) presents new mathematical insights into the effectiveness of this framework, derived from its relationship to locality-sensitive hashing (LSH) and to concomitant statistics, (5) introduces a new model, the Chorus of Relational Descriptors (ChoRD), that extends this framework to scene representation and interpretation, (6) describes its implementation and testing, and finally (7) suggests possible directions in which the present research program can be

  2. Self-similar aftershock rates

    NASA Astrophysics Data System (ADS)

    Davidsen, Jörn; Baiesi, Marco

    2016-08-01

    In many important systems exhibiting crackling noise—an intermittent avalanchelike relaxation response with power-law and, thus, self-similar distributed event sizes—the "laws" for the rate of activity after large events are not consistent with the overall self-similar behavior expected on theoretical grounds. This is particularly true for the case of seismicity, and a satisfying solution to this paradox has remained outstanding. Here, we propose a generalized description of the aftershock rates which is both self-similar and consistent with all other known self-similar features. Comparing our theoretical predictions with high-resolution earthquake data from Southern California we find excellent agreement, providing particularly clear evidence for a unified description of aftershocks and foreshocks. This may offer an improved framework for time-dependent seismic hazard assessment and earthquake forecasting.

  3. Self-similar aftershock rates.

    PubMed

    Davidsen, Jörn; Baiesi, Marco

    2016-08-01

    In many important systems exhibiting crackling noise-an intermittent avalanchelike relaxation response with power-law and, thus, self-similar distributed event sizes-the "laws" for the rate of activity after large events are not consistent with the overall self-similar behavior expected on theoretical grounds. This is particularly true for the case of seismicity, and a satisfying solution to this paradox has remained outstanding. Here, we propose a generalized description of the aftershock rates which is both self-similar and consistent with all other known self-similar features. Comparing our theoretical predictions with high-resolution earthquake data from Southern California we find excellent agreement, providing particularly clear evidence for a unified description of aftershocks and foreshocks. This may offer an improved framework for time-dependent seismic hazard assessment and earthquake forecasting.

  4. Similarity of the Velocity Profile

    DTIC Science & Technology

    2014-10-01

    su x (with 0 constantb = ) is the empirically derived velocity scale developed by Zagarola and Smits [5] for turbulent boundary layer flow...Zagarola and Smits and others have shown that the velocity scaling factor given by Eq. 5 with sδ as the boundary layer thickness can collapse certain...and Smits , it is important to point out that the fact that the similarity length scale factor and the similarity velocity scale factor must follow

  5. Some more similarities between Peirce and Skinner

    PubMed Central

    Moxley, Roy A.

    2002-01-01

    C. S. Peirce is noted for pioneering a variety of views, and the case is made here for the similarities and parallels between his views and B. F. Skinner's radical behaviorism. In addition to parallels previously noted, these similarities include an advancement of experimental science, a behavioral psychology, a shift from nominalism to realism, an opposition to positivism, a selectionist account for strengthening behavior, the importance of a community of selves, a recursive approach to method, and the probabilistic nature of truth. Questions are raised as to the extent to which Skinner's radical behaviorism, as distinguished from his S-R positivism, may be seen as an extension of Peirce's pragmatism. PMID:22478387

  6. What difference reveals about similarity.

    PubMed

    Sagi, Eyal; Gentner, Dedre; Lovett, Andrew

    2012-08-01

    Detecting that two images are different is faster for highly dissimilar images than for highly similar images. Paradoxically, we showed that the reverse occurs when people are asked to describe how two images differ--that is, to state a difference between two images. Following structure-mapping theory, we propose that this disassociation arises from the multistage nature of the comparison process. Detecting that two images are different can be done in the initial (local-matching) stage, but only for pairs with low overlap; thus, "different" responses are faster for low-similarity than for high-similarity pairs. In contrast, identifying a specific difference generally requires a full structural alignment of the two images, and this alignment process is faster for high-similarity pairs. We described four experiments that demonstrate this dissociation and show that the results can be simulated using the Structure-Mapping Engine. These results pose a significant challenge for nonstructural accounts of similarity comparison and suggest that structural alignment processes play a significant role in visual comparison.

  7. Similarity searching in large combinatorial chemistry spaces

    NASA Astrophysics Data System (ADS)

    Rarey, Matthias; Stahl, Martin

    2001-06-01

    We present a novel algorithm, called Ftrees-FS, for similarity searching in large chemistry spaces based on dynamic programming. Given a query compound, the algorithm generates sets of compounds from a given chemistry space that are similar to the query. The similarity search is based on the feature tree similarity measure representing molecules by tree structures. This descriptor allows handling combinatorial chemistry spaces as a whole instead of looking at subsets of enumerated compounds. Within few minutes of computing time, the algorithm is able to find the most similar compound in very large spaces as well as sets of compounds at an arbitrary similarity level. In addition, the diversity among the generated compounds can be controlled. A set of 17 000 fragments of known drugs, generated by the RECAP procedure from the World Drug Index, was used as the search chemistry space. These fragments can be combined to more than 1018 compounds of reasonable size. For validation, known antagonists/inhibitors of several targets including dopamine D4, histamine H1, and COX2 are used as queries. Comparison of the compounds created by Ftrees-FS to other known actives demonstrates the ability of the method to jump between structurally unrelated molecule classes.

  8. Do birds and beetles show similar responses to urbanization?

    PubMed

    Gagné, Sara A; Fahrig, Lenore

    2011-09-01

    introduced birds and introduced beetles and similar patterns of community simplification in both taxa. To better understand and mitigate the effects of urbanization on biodiversity, we suggest that, in addition to the responses of birds, future research should focus on the responses of other taxa in the urban matrix.

  9. A novel design strategy for nanoparticles on nanopatterns: interferometric lithographic patterning of Mms6 biotemplated magnetic nanoparticles† †Electronic supplementary information (ESI) available. See DOI: 10.1039/c5tc03895b Click here for additional data file.

    PubMed Central

    Bird, S. M.; El-Zubir, O.; Rawlings, A. E.; Leggett, G. J.

    2016-01-01

    Nanotechnology demands the synthesis of highly precise, functional materials, tailored for specific applications. One such example is bit patterned media. These high-density magnetic data-storage materials require specific and uniform magnetic nanoparticles (MNPs) to be patterned over large areas (cm2 range) in exact nanoscale arrays. However, the realisation of such materials for nanotechnology applications depends upon reproducible fabrication methods that are both precise and environmentally-friendly, for cost-effective scale-up. A potentially ideal biological fabrication methodology is biomineralisation. This is the formation of inorganic minerals within organisms, and is known to be highly controlled down to the nanoscale whilst being carried out under ambient conditions. The magnetotactic bacterium Magnetospirillum magneticum AMB-1 uses a suite of dedicated biomineralisation proteins to control the formation of magnetite MNPs within their cell. One of these proteins, Mms6, has been shown to control formation of magnetite MNPs in vitro. We have previously used Mms6 on micro-contact printed (μCP) patterned self-assembled monolayer (SAM) surfaces to control the formation and location of MNPs in microscale arrays, offering a bioinspired and green-route to fabrication. However, μCP cannot produce patterns reliably with nanoscale dimensions, and most alternative nanofabrication techniques are slow and expensive. Interferometric lithography (IL) uses the interference of laser light to produce nanostructures over large areas via a simple process implemented under ambient conditions. Here we combine the bottom-up biomediated approach with a top down IL methodology to produce arrays of uniform magnetite MNPs (86 ± 21 nm) with a period of 357 nm. This shows a potentially revolutionary strategy for the production of magnetic arrays with nanoscale precision in a process with low environmental impact, which could be scaled readily to facilitate large-scale production of

  10. Comparison of hydrological similarity measures

    NASA Astrophysics Data System (ADS)

    Rianna, Maura; Ridolfi, Elena; Manciola, Piergiorgio; Napolitano, Francesco; Russo, Fabio

    2016-04-01

    The use of a traditional at site approach for the statistical characterization and simulation of spatio-temporal precipitation fields has a major recognized drawback. Indeed, the weakness of the methodology is related to the estimation of rare events and it involves the uncertainty of the at-site sample statistical inference, because of the limited length of records. In order to overcome the lack of at-site observations, regional frequency approach uses the idea of substituting space for time to estimate design floods. The conventional regional frequency analysis estimates quantile values at a specific site from multi-site analysis. The main idea is that homogeneous sites, once pooled together, have similar probability distribution curves of extremes, except for a scaling factor. The method for pooling groups of sites can be based on geographical or climatological considerations. In this work the region of influence (ROI) pooling method is compared with an entropy-based one. The ROI is a flexible pooling group approach which defines for each site its own "region" formed by a unique set of similar stations. The similarity is found through the Euclidean distance metric in the attribute space. Here an alternative approach based on entropy is introduced to cluster homogeneous sites. The core idea is that homogeneous sites share a redundant (i.e. similar) amount of information. Homogeneous sites are pooled through a hierarchical selection based on the mutual information index (i.e. a measure of redundancy). The method is tested on precipitation data in Central Italy area.

  11. What Difference Reveals about Similarity

    ERIC Educational Resources Information Center

    Sagi, Eyal; Gentner, Dedre; Lovett, Andrew

    2012-01-01

    Detecting that two images are different is faster for highly dissimilar images than for highly similar images. Paradoxically, we showed that the reverse occurs when people are asked to describe "how" two images differ--that is, to state a difference between two images. Following structure-mapping theory, we propose that this…

  12. Phylogenetic metrics of community similarity.

    PubMed

    Ives, Anthony R; Helmus, Matthew R

    2010-11-01

    We derive a new metric of community similarity that takes into account the phylogenetic relatedness among species. This metric, phylogenetic community dissimilarity (PCD), can be partitioned into two components, a nonphylogenetic component that reflects shared species between communities (analogous to Sørensen' s similarity metric) and a phylogenetic component that reflects the evolutionary relationships among nonshared species. Therefore, even if a species is not shared between two communities, it will increase the similarity of the two communities if it is phylogenetically related to species in the other community. We illustrate PCD with data on fish and aquatic macrophyte communities from 59 temperate lakes. Dissimilarity between fish communities associated with environmental differences between lakes often has a phylogenetic component, whereas this is not the case for macrophyte communities. With simulations, we then compare PCD with two other metrics of phylogenetic community similarity, II(ST) and UniFrac. Of the three metrics, PCD was best at identifying environmental drivers of community dissimilarity, showing lower variability and greater statistical power. Thus, PCD is a statistically powerful metric that separates the effects of environmental drivers on compositional versus phylogenetic components of community structure.

  13. Genetic and ‘cultural’ similarity in wild chimpanzees

    PubMed Central

    Langergraber, Kevin E.; Boesch, Christophe; Inoue, Eiji; Inoue-Murayama, Miho; Mitani, John C.; Nishida, Toshisada; Pusey, Anne; Reynolds, Vernon; Schubert, Grit; Wrangham, Richard W.; Wroblewski, Emily; Vigilant, Linda

    2011-01-01

    The question of whether animals possess ‘cultures’ or ‘traditions’ continues to generate widespread theoretical and empirical interest. Studies of wild chimpanzees have featured prominently in this discussion, as the dominant approach used to identify culture in wild animals was first applied to them. This procedure, the ‘method of exclusion,’ begins by documenting behavioural differences between groups and then infers the existence of culture by eliminating ecological explanations for their occurrence. The validity of this approach has been questioned because genetic differences between groups have not explicitly been ruled out as a factor contributing to between-group differences in behaviour. Here we investigate this issue directly by analysing genetic and behavioural data from nine groups of wild chimpanzees. We find that the overall levels of genetic and behavioural dissimilarity between groups are highly and statistically significantly correlated. Additional analyses show that only a very small number of behaviours vary between genetically similar groups, and that there is no obvious pattern as to which classes of behaviours (e.g. tool-use versus communicative) have a distribution that matches patterns of between-group genetic dissimilarity. These results indicate that genetic dissimilarity cannot be eliminated as playing a major role in generating group differences in chimpanzee behaviour. PMID:20719777

  14. What causes similarity in catchments?

    NASA Astrophysics Data System (ADS)

    Savenije, Hubert

    2014-05-01

    One of the biggest issues in hydrology is how to handle the heterogeneity of catchment properties at different scales. But is this really such a big issue? Is this problem not merely the consequence of how we conceptualise and how we model catchments? Is there not far more similarity than we observe. Maybe we are not looking at the right things or at the right scale to see the similarity. The identity of catchments is largely determined by: the landscape, the ecosystem living on the landscape, and the geology, in that order. Soils, which are often seen as a crucial aspect of hydrological behaviour, are far less important, as will be demonstrated. The main determinants of hydrological behaviour are: the landscape composition, the rooting depth and the phenology. These determinants are a consequence of landscape and ecosystem evolution, which, in turn, are the manifestations of entropy production. There are striking similarities between catchments. The different runoff processes from hillslopes are linked and similar in different environments (McDonnell, 2013). Wetlands behave similarly all over the world. The key is to classify landscapes and to link the ecosystems living on them to climate. The ecosystem then is the main controller of hydrological behaviour. Besides phenology, the rooting depth is key in determining runoff behaviour. Both are strongly linked to climate and much less to soil properties. An example is given of how rooting depth is determined by climate, and how rooting depth can be predicted without calibration, providing a strong constraints on the prediction of rainfall partitioning and catchment runoff.

  15. Examining Similarity Structure: Multidimensional Scaling and Related Approaches in Neuroimaging

    PubMed Central

    Shinkareva, Svetlana V.; Wedell, Douglas H.

    2013-01-01

    This paper covers similarity analyses, a subset of multivariate pattern analysis techniques that are based on similarity spaces defined by multivariate patterns. These techniques offer several advantages and complement other methods for brain data analyses, as they allow for comparison of representational structure across individuals, brain regions, and data acquisition methods. Particular attention is paid to multidimensional scaling and related approaches that yield spatial representations or provide methods for characterizing individual differences. We highlight unique contributions of these methods by reviewing recent applications to functional magnetic resonance imaging data and emphasize areas of caution in applying and interpreting similarity analysis methods. PMID:23662162

  16. Earthquake detection through computationally efficient similarity search.

    PubMed

    Yoon, Clara E; O'Reilly, Ossian; Bergen, Karianne J; Beroza, Gregory C

    2015-12-01

    Seismology is experiencing rapid growth in the quantity of data, which has outpaced the development of processing algorithms. Earthquake detection-identification of seismic events in continuous data-is a fundamental operation for observational seismology. We developed an efficient method to detect earthquakes using waveform similarity that overcomes the disadvantages of existing detection methods. Our method, called Fingerprint And Similarity Thresholding (FAST), can analyze a week of continuous seismic waveform data in less than 2 hours, or 140 times faster than autocorrelation. FAST adapts a data mining algorithm, originally designed to identify similar audio clips within large databases; it first creates compact "fingerprints" of waveforms by extracting key discriminative features, then groups similar fingerprints together within a database to facilitate fast, scalable search for similar fingerprint pairs, and finally generates a list of earthquake detections. FAST detected most (21 of 24) cataloged earthquakes and 68 uncataloged earthquakes in 1 week of continuous data from a station located near the Calaveras Fault in central California, achieving detection performance comparable to that of autocorrelation, with some additional false detections. FAST is expected to realize its full potential when applied to extremely long duration data sets over a distributed network of seismic stations. The widespread application of FAST has the potential to aid in the discovery of unexpected seismic signals, improve seismic monitoring, and promote a greater understanding of a variety of earthquake processes.

  17. Earthquake detection through computationally efficient similarity search

    PubMed Central

    Yoon, Clara E.; O’Reilly, Ossian; Bergen, Karianne J.; Beroza, Gregory C.

    2015-01-01

    Seismology is experiencing rapid growth in the quantity of data, which has outpaced the development of processing algorithms. Earthquake detection—identification of seismic events in continuous data—is a fundamental operation for observational seismology. We developed an efficient method to detect earthquakes using waveform similarity that overcomes the disadvantages of existing detection methods. Our method, called Fingerprint And Similarity Thresholding (FAST), can analyze a week of continuous seismic waveform data in less than 2 hours, or 140 times faster than autocorrelation. FAST adapts a data mining algorithm, originally designed to identify similar audio clips within large databases; it first creates compact “fingerprints” of waveforms by extracting key discriminative features, then groups similar fingerprints together within a database to facilitate fast, scalable search for similar fingerprint pairs, and finally generates a list of earthquake detections. FAST detected most (21 of 24) cataloged earthquakes and 68 uncataloged earthquakes in 1 week of continuous data from a station located near the Calaveras Fault in central California, achieving detection performance comparable to that of autocorrelation, with some additional false detections. FAST is expected to realize its full potential when applied to extremely long duration data sets over a distributed network of seismic stations. The widespread application of FAST has the potential to aid in the discovery of unexpected seismic signals, improve seismic monitoring, and promote a greater understanding of a variety of earthquake processes. PMID:26665176

  18. Effect of acoustic similarity on short-term auditory memory in the monkey.

    PubMed

    Scott, Brian H; Mishkin, Mortimer; Yin, Pingbo

    2013-04-01

    Recent evidence suggests that the monkey's short-term memory in audition depends on a passively retained sensory trace as opposed to a trace reactivated from long-term memory for use in working memory. Reliance on a passive sensory trace could render memory particularly susceptible to confusion between sounds that are similar in some acoustic dimension. If so, then in delayed matching-to-sample, the monkey's performance should be predicted by the similarity in the salient acoustic dimension between the sample and subsequent test stimulus, even at very short delays. To test this prediction and isolate the acoustic features relevant to short-term memory, we examined the pattern of errors made by two rhesus monkeys performing a serial, auditory delayed match-to-sample task with interstimulus intervals of 1 s. The analysis revealed that false-alarm errors did indeed result from similarity-based confusion between the sample and the subsequent nonmatch stimuli. Manipulation of the stimuli showed that removal of spectral cues was more disruptive to matching behavior than removal of temporal cues. In addition, the effect of acoustic similarity on false-alarm response was stronger at the first nonmatch stimulus than at the second one. This pattern of errors would be expected if the first nonmatch stimulus overwrote the sample's trace, and suggests that the passively retained trace is not only vulnerable to similarity-based confusion but is also highly susceptible to overwriting.

  19. Mechanisms for similarity based cooperation

    NASA Astrophysics Data System (ADS)

    Traulsen, A.

    2008-06-01

    Cooperation based on similarity has been discussed since Richard Dawkins introduced the term “green beard” effect. In these models, individuals cooperate based on an aribtrary signal (or tag) such as the famous green beard. Here, two different models for such tag based cooperation are analysed. As neutral drift is important in both models, a finite population framework is applied. The first model, which we term “cooperative tags” considers a situation in which groups of cooperators are formed by some joint signal. Defectors adopting the signal and exploiting the group can lead to a breakdown of cooperation. In this case, conditions are derived under which the average abundance of the more cooperative strategy exceeds 50%. The second model considers a situation in which individuals start defecting towards others that are not similar to them. This situation is termed “defective tags”. It is shown that in this case, individuals using tags to cooperate exclusively with their own kind dominate over unconditional cooperators.

  20. Inferring Trust Based on Similarity with TILLIT

    NASA Astrophysics Data System (ADS)

    Tavakolifard, Mozhgan; Herrmann, Peter; Knapskog, Svein J.

    A network of people having established trust relations and a model for propagation of related trust scores are fundamental building blocks in many of today’s most successful e-commerce and recommendation systems. However, the web of trust is often too sparse to predict trust values between non-familiar people with high accuracy. Trust inferences are transitive associations among users in the context of an underlying social network and may provide additional information to alleviate the consequences of the sparsity and possible cold-start problems. Such approaches are helpful, provided that a complete trust path exists between the two users. An alternative approach to the problem is advocated in this paper. Based on collaborative filtering one can exploit the like-mindedness resp. similarity of individuals to infer trust to yet unknown parties which increases the trust relations in the web. For instance, if one knows that with respect to a specific property, two parties are trusted alike by a large number of different trusters, one can assume that they are similar. Thus, if one has a certain degree of trust to the one party, one can safely assume a very similar trustworthiness of the other one. In an attempt to provide high quality recommendations and proper initial trust values even when no complete trust propagation path or user profile exists, we propose TILLIT — a model based on combination of trust inferences and user similarity. The similarity is derived from the structure of the trust graph and users’ trust behavior as opposed to other collaborative-filtering based approaches which use ratings of items or user’s profile. We describe an algorithm realizing the approach based on a combination of trust inferences and user similarity, and validate the algorithm using a real large-scale data-set.

  1. Quantifying the similarity of seismic polarizations

    NASA Astrophysics Data System (ADS)

    Jones, Joshua P.; Eaton, David W.; Caffagni, Enrico

    2016-02-01

    Assessing the similarities of seismic attributes can help identify tremor, low signal-to-noise (S/N) signals and converted or reflected phases, in addition to diagnosing site noise and sensor misalignment in arrays. Polarization analysis is a widely accepted method for studying the orientation and directional characteristics of seismic phases via computed attributes, but similarity is ordinarily discussed using qualitative comparisons with reference values or known seismic sources. Here we introduce a technique for quantitative polarization similarity that uses weighted histograms computed in short, overlapping time windows, drawing on methods adapted from the image processing and computer vision literature. Our method accounts for ambiguity in azimuth and incidence angle and variations in S/N ratio. Measuring polarization similarity allows easy identification of site noise and sensor misalignment and can help identify coherent noise and emergent or low S/N phase arrivals. Dissimilar azimuths during phase arrivals indicate misaligned horizontal components, dissimilar incidence angles during phase arrivals indicate misaligned vertical components and dissimilar linear polarization may indicate a secondary noise source. Using records of the Mw = 8.3 Sea of Okhotsk earthquake, from Canadian National Seismic Network broad-band sensors in British Columbia and Yukon Territory, Canada, and a vertical borehole array at Hoadley gas field, central Alberta, Canada, we demonstrate that our method is robust to station spacing. Discrete wavelet analysis extends polarization similarity to the time-frequency domain in a straightforward way. Time-frequency polarization similarities of borehole data suggest that a coherent noise source may have persisted above 8 Hz several months after peak resource extraction from a `flowback' type hydraulic fracture.

  2. Similarities in Aegyptopithecus and Afropithecus facial morphology.

    PubMed

    Leakey, M G; Leakey, R E; Richtsmeier, J T; Simons, E L; Walker, A C

    1991-01-01

    Recently discovered cranial fossils from the Oligocene deposits of the Fayum depression in Egypt provide many details of the facial morphology of Aegyptopithecus zeuxis. Similar features are found in the Miocene hominoid Afropithecus turkanensis. Their presence is the first good evidence of a strong phenetic link between the Oligocene and Miocene hominoids of Africa. A comparison of trait lists emphasizes the similarities of the two fossil species, and leads us to conclude that the two fossil genera share many primitive facial features. In addition, we studied facial morphology using finite-element scaling analysis and found that the two genera show similarities in morphological integration, or the way in which biological landmarks relate to one another in three dimensions to define the form of the organism. Size differences between the two genera are much greater than the relatively minor shape differences. Analysis of variability in landmark location among the four Aegyptopithecus specimens indicates that variability within the sample is not different from that found within two samples of modern macaques. We propose that the shape differences found among the four Aegyptopithecus specimens simply reflect individual variation in facial characteristics, and that the similarities in facial morphology between Aegyptopithecus and Afropithecus probably represent a complex of primitive facial features retained over millions of years.

  3. [Combination similarity algorithm on chromatographic fingerprints].

    PubMed

    Zhan, Xueyan; Shi, Xinyuan; Duan, Tianxuan; Li, Lei; Qiao, Yanjiang

    2010-11-01

    The similarity of chromatographic fingerprints is one of the effective approaches evaluating the quality stability of Chinese medicine, and the cosine of angle plays an important role in the application of similarity. However, the cosine approach is insensitive to the data difference when the distribution range of the data sets is wide. When the data proportion of the reference sample and the test sample is greatly different, it confirms that the sensitivity of the cosine to the differences of the peaks owned by both the reference sample and the test sample differs from the peaks owned only by the reference sample or the test sample in this study. The method considers the peaks owned by one sample in addition to peaks owned by both samples, and determines their own appropriate weigh targeting for the maximal homostasis value of proportion among the peaks of all of Smilax glabra Roxb. samples. The method based on sample data could reflect the difference in the chemical composition area ratio between the reference sample and test samples sensitively, and measures the similarity among the nine Smilax glabra Roxb. samples, which is a new similarity algorithm for evaluating the quality stability of herbal medicines.

  4. Interneurons targeting similar layers receive synaptic inputs with similar kinetics.

    PubMed

    Cossart, Rosa; Petanjek, Zdravko; Dumitriu, Dani; Hirsch, June C; Ben-Ari, Yehezkel; Esclapez, Monique; Bernard, Christophe

    2006-01-01

    GABAergic interneurons play diverse and important roles in controlling neuronal network dynamics. They are characterized by an extreme heterogeneity morphologically, neurochemically, and physiologically, but a functionally relevant classification is still lacking. Present taxonomy is essentially based on their postsynaptic targets, but a physiological counterpart to this classification has not yet been determined. Using a quantitative analysis based on multidimensional clustering of morphological and physiological variables, we now demonstrate a strong correlation between the kinetics of glutamate and GABA miniature synaptic currents received by CA1 hippocampal interneurons and the laminar distribution of their axons: neurons that project to the same layer(s) receive synaptic inputs with similar kinetics distributions. In contrast, the kinetics distributions of GABAergic and glutamatergic synaptic events received by a given interneuron do not depend upon its somatic location or dendritic arborization. Although the mechanisms responsible for this unexpected observation are still unclear, our results suggest that interneurons may be programmed to receive synaptic currents with specific temporal dynamics depending on their targets and the local networks in which they operate.

  5. Path similarity skeleton graph matching.

    PubMed

    Bai, Xiang; Latecki, Longin Jan

    2008-07-01

    This paper presents a novel framework to for shape recognition based on object silhouettes. The main idea is to match skeleton graphs by comparing the shortest paths between skeleton endpoints. In contrast to typical tree or graph matching methods, we completely ignore the topological graph structure. Our approach is motivated by the fact that visually similar skeleton graphs may have completely different topological structures. The proposed comparison of shortest paths between endpoints of skeleton graphs yields correct matching results in such cases. The skeletons are pruned by contour partitioning with Discrete Curve Evolution, which implies that the endpoints of skeleton branches correspond to visual parts of the objects. The experimental results demonstrate that our method is able to produce correct results in the presence of articulations, stretching, and occlusion.

  6. Selection of USSR foreign similarity regions

    NASA Technical Reports Server (NTRS)

    Disler, J. M. (Principal Investigator)

    1982-01-01

    The similarity regions in the United States and Canada were selected to parallel the conditions that affect labeling and classification accuracies in the U.S.S.R. indicator regions. In addition to climate, a significant condition that affects labeling and classification accuracies in the U.S.S.R. is the proportion of barley and wheat grown in a given region (based on sown areas). The following regions in the United States and Canada were determined to be similar to the U.S.S.R. indicator regions: (1) Montana agrophysical unit (APU) 104 corresponds to the Belorussia high barley region; (2) North Dakota and Minnesota APU 20 and secondary region southern Manitoba and Saskatchewan correspond to the Ural RSFSR barley and spring wheat region; (3) Montana APU 23 corresponds to he North Caucasus barley and winter wheat region. Selection criteria included climates, crop type, crop distribution, growth cycles, field sizes, and field shapes.

  7. Encoding protein-ligand interaction patterns in fingerprints and graphs.

    PubMed

    Desaphy, Jérémy; Raimbaud, Eric; Ducrot, Pierre; Rognan, Didier

    2013-03-25

    We herewith present a novel and universal method to convert protein-ligand coordinates into a simple fingerprint of 210 integers registering the corresponding molecular interaction pattern. Each interaction (hydrophobic, aromatic, hydrogen bond, ionic bond, metal complexation) is detected on the fly and physically described by a pseudoatom centered either on the interacting ligand atom, the interacting protein atom, or the geometric center of both interacting atoms. Counting all possible triplets of interaction pseudoatoms within six distance ranges, and pruning the full integer vector to keep the most frequent triplets enables the definition of a simple (210 integers) and coordinate frame-invariant interaction pattern descriptor (TIFP) that can be applied to compare any pair of protein-ligand complexes. TIFP fingerprints have been calculated for ca. 10,000 druggable protein-ligand complexes therefore enabling a wide comparison of relationships between interaction pattern similarity and ligand or binding site pairwise similarity. We notably show that interaction pattern similarity strongly depends on binding site similarity. In addition to the TIFP fingerprint which registers intermolecular interactions between a ligand and its target protein, we developed two tools (Ishape, Grim) to align protein-ligand complexes from their interaction patterns. Ishape is based on the overlap of interaction pseudoatoms using a smooth Gaussian function, whereas Grim utilizes a standard clique detection algorithm to match interaction pattern graphs. Both tools are complementary and enable protein-ligand complex alignments capitalizing on both global and local pattern similarities. The new fingerprint and companion alignment tools have been successfully used in three scenarios: (i) interaction-biased alignment of protein-ligand complexes, (ii) postprocessing docking poses according to known interaction patterns for a particular target, and (iii) virtual screening for bioisosteric

  8. Similarity and discrimination learning in humans.

    PubMed

    Noguera, M; Grau, M; Peris, J M; Barbería, I; Chamizo, V D

    2008-10-01

    In an experiment involving a new behavioural preparation the role played by similarity in discrimination learning was examined using visual patterns (i.e., paintings) that might share common elements (specifically, A, BC, and ABC). A-C were small stars of three specific colours (target colours), which were intermixed with other stars of two different colours (distracting colours). The target colours were balanced through A-C. Students received discrimination training in which a fictitious painter was the author of paintings A and BC, while paintings ABC were assigned to a second fictitious painter. During training, the students had to make a choice, in the presence of each pattern, between two response keys, each of them indicating one of the painters. The time taken to respond was also measured. Feedback was always given after each key-press. The results showed that while at times the A+ ABC- discrimination was acquired more readily than was the BC+ ABC- discrimination, on other occasions the reverse was also true, the critical factor being the way in which the colours were combined.

  9. A toolbox for representational similarity analysis.

    PubMed

    Nili, Hamed; Wingfield, Cai; Walther, Alexander; Su, Li; Marslen-Wilson, William; Kriegeskorte, Nikolaus

    2014-04-01

    Neuronal population codes are increasingly being investigated with multivariate pattern-information analyses. A key challenge is to use measured brain-activity patterns to test computational models of brain information processing. One approach to this problem is representational similarity analysis (RSA), which characterizes a representation in a brain or computational model by the distance matrix of the response patterns elicited by a set of stimuli. The representational distance matrix encapsulates what distinctions between stimuli are emphasized and what distinctions are de-emphasized in the representation. A model is tested by comparing the representational distance matrix it predicts to that of a measured brain region. RSA also enables us to compare representations between stages of processing within a given brain or model, between brain and behavioral data, and between individuals and species. Here, we introduce a Matlab toolbox for RSA. The toolbox supports an analysis approach that is simultaneously data- and hypothesis-driven. It is designed to help integrate a wide range of computational models into the analysis of multichannel brain-activity measurements as provided by modern functional imaging and neuronal recording techniques. Tools for visualization and inference enable the user to relate sets of models to sets of brain regions and to statistically test and compare the models using nonparametric inference methods. The toolbox supports searchlight-based RSA, to continuously map a measured brain volume in search of a neuronal population code with a specific geometry. Finally, we introduce the linear-discriminant t value as a measure of representational discriminability that bridges the gap between linear decoding analyses and RSA. In order to demonstrate the capabilities of the toolbox, we apply it to both simulated and real fMRI data. The key functions are equally applicable to other modalities of brain-activity measurement. The toolbox is freely

  10. Ceramics with Different Additives

    NASA Astrophysics Data System (ADS)

    Wang, Juanjuan; Feng, Lajun; Lei, Ali; Zhao, Kang; Yan, Aijun

    2014-09-01

    Li2CO3, MgCO3, BaCO3, and Bi2O3 dopants were introduced into CaCu3Ti4O12 (CCTO) ceramics in order to improve the dielectric properties. The CCTO ceramics were prepared by conventional solid-state reaction method. The phase structure, microstructure, and dielectric behavior were carefully investigated. The pure structure without any impurity phases can be confirmed by the x-ray diffraction patterns. Scanning Electron Microscopy (SEM) analysis illuminated that the grains of Ca0.90Li0.20Cu3Ti4O12 ceramics were greater than that of pure CCTO. It was important for the properties of the CCTO ceramics to study the additives in complex impedance spectroscopy. It was found that the Ca0.90Li0.20Cu3Ti4O12 ceramics had the higher permittivity (>45000), the lower dielectric loss (<0.025) than those of CCTO at 1 kHz at room temperature and good temperature stability from -30 to 75 °C.

  11. Additivity of Feature-Based and Symmetry-Based Grouping Effects in Multiple Object Tracking.

    PubMed

    Wang, Chundi; Zhang, Xuemin; Li, Yongna; Lyu, Chuang

    2016-01-01

    Multiple object tracking (MOT) is an attentional process wherein people track several moving targets among several distractors. Symmetry, an important indicator of regularity, is a general spatial pattern observed in natural and artificial scenes. According to the "laws of perceptual organization" proposed by Gestalt psychologists, regularity is a principle of perceptual grouping, such as similarity and closure. A great deal of research reported that feature-based similarity grouping (e.g., grouping based on color, size, or shape) among targets in MOT tasks can improve tracking performance. However, no additive feature-based grouping effects have been reported where the tracking objects had two or more features. "Additive effect" refers to a greater grouping effect produced by grouping based on multiple cues instead of one cue. Can spatial symmetry produce a similar grouping effect similar to that of feature similarity in MOT tasks? Are the grouping effects based on symmetry and feature similarity additive? This study includes four experiments to address these questions. The results of Experiments 1 and 2 demonstrated the automatic symmetry-based grouping effects. More importantly, an additive grouping effect of symmetry and feature similarity was observed in Experiments 3 and 4. Our findings indicate that symmetry can produce an enhanced grouping effect in MOT and facilitate the grouping effect based on color or shape similarity. The "where" and "what" pathways might have played an important role in the additive grouping effect.

  12. Additivity of Feature-Based and Symmetry-Based Grouping Effects in Multiple Object Tracking

    PubMed Central

    Wang, Chundi; Zhang, Xuemin; Li, Yongna; Lyu, Chuang

    2016-01-01

    Multiple object tracking (MOT) is an attentional process wherein people track several moving targets among several distractors. Symmetry, an important indicator of regularity, is a general spatial pattern observed in natural and artificial scenes. According to the “laws of perceptual organization” proposed by Gestalt psychologists, regularity is a principle of perceptual grouping, such as similarity and closure. A great deal of research reported that feature-based similarity grouping (e.g., grouping based on color, size, or shape) among targets in MOT tasks can improve tracking performance. However, no additive feature-based grouping effects have been reported where the tracking objects had two or more features. “Additive effect” refers to a greater grouping effect produced by grouping based on multiple cues instead of one cue. Can spatial symmetry produce a similar grouping effect similar to that of feature similarity in MOT tasks? Are the grouping effects based on symmetry and feature similarity additive? This study includes four experiments to address these questions. The results of Experiments 1 and 2 demonstrated the automatic symmetry-based grouping effects. More importantly, an additive grouping effect of symmetry and feature similarity was observed in Experiments 3 and 4. Our findings indicate that symmetry can produce an enhanced grouping effect in MOT and facilitate the grouping effect based on color or shape similarity. The “where” and “what” pathways might have played an important role in the additive grouping effect. PMID:27199875

  13. A Case of 22q11 Deletion Syndrome (22q11DS) with a Panayiotopoulos Epileptic Pattern: Are Additional Copy-Number Variations a Possible Second Hit in Modulating the 22q11DS Phenotype?

    PubMed Central

    Bertini, Veronica; Valetto, Angelo; Azzarà, Alessia; Legitimo, Annalisa; Saggese, Giuseppe; Consolini, Rita; Orsini, Alessandro; Bonuccelli, Alice

    2017-01-01

    “22q11 deletion syndrome” (22q11DS) is a rare genetic syndrome, in which most patients share the same deletion, but their clinical features may vary a great deal. The genetic mechanisms underlying the variable expressivity and reduced penetrance of 22q11DS still have to be fully elucidated. Epilepsy has been reported in about 15.2% of the patients; however, few studies have focused on this topic, and in most cases, a detailed epileptic profile is missing. Since only a minority of patients experience epileptic seizures, 22q11deletion can be considered a predisposing factor, which is not sufficient “per se” to cause epilepsy; to date, no candidate gene for epilepsy has been identified in the deleted region. We report on a 6-year-old girl with 22q11DS presenting a form of epilepsy that can be classified as “Panayiotopoulos syndrome.” Array CGH revealed an additional microduplication of 172 kb in 2q37, harboring three genes. One of these, DGKD (diacylglycerol kinase delta), is interrupted by the distal breakpoint of the duplication. DGKD encodes a cytoplasmic enzyme that phosphorylates diacylglycerol to produce phosphatidic acid. This is an important second messenger in a pathway of lipid signaling that has been implicated in epilepsy and other neurological diseases. Disruption of DGKD by a t(X;2) has been previously reported in a patient with epilepsy. The 2q37 microduplication was inherited from her mother, who never experienced epileptic seizures, thus this imbalance is not “per se” sufficient to cause epilepsy. It can be hypothesized that the epileptic phenotype is provoked by the simultaneous presence of 22q11.2 deletion and 2q37 duplication. It has been shown that rare additional copy-number variations (CNVs) outside the 22q11.2 region may modulate the risk of congenital heart defects. It is possible that also for the epileptic phenotype, the additional CNVs may represent an important modifying factor underlying the variable expressivity and

  14. Similarity and scale in catchment storm response

    NASA Technical Reports Server (NTRS)

    Wood, Eric F.; Sivapalan, Murugesu; Beven, Keith

    1993-01-01

    Until recently, very little progress had been made in understanding the relationship between small-scale variability of topography, soil, and rainfalls and the storm response seen at the catchment scale. The work reviewed here represents the first attempt at a systematic theoretical framework for such understanding in the context of surface runoff generation by different processes. The parameterization of hydrological processes over a range of scales is examined, and the concept of the 'representative elementary area' (REA) is introduced. The REA is a fundamental scale for catchment modeling at which continuum assumptions can be applied for the spatially variable controls and parameters, and spatial patterns no longer have to be considered explicitly. The investigation of scale leads into the concept of hydrologic similarity in which the effects of the environmental controls on runoff generation and flood frequency response be investigated independently of catchment scale. The paper reviews the authors' initial results and hopefully will motivate others to also investigate the issues of hydrologic scale and similarity.

  15. Comparing investigation of pattern formation in glow and streamer DBD

    NASA Astrophysics Data System (ADS)

    Li, Ben; Ouyang, Jiting

    2016-11-01

    In this paper, we investigate the behaviors of patterns in dielectric barrier discharge (DBD) in glow and streamer regimes under different operating conditions (driving frequency and voltage) and external electric/magnetic field to explore the similarity and difference of pattern formation. It is found that patterns in both glow and streamer DBDs can be homogenized by decreasing the driving frequency to a low level. But filamentary streamers can still appear at low frequency when the voltage is much higher. With an additional lateral electric field, patterns in both regimes can be homogenized. However, an axial magnetic field makes the glow DBD homogeneous, while the streamer DBD decreases in filamentary size. In both regimes, dynamics and distribution of the space charges, rather than the surface charges, play the predominant role in the formation of DBD patterns. But the surface charges may also play an important role in pattern formation, especially in streamer DBD.

  16. Patterned control of human locomotion

    PubMed Central

    Lacquaniti, Francesco; Ivanenko, Yuri P; Zago, Myrka

    2012-01-01

    There is much experimental evidence for the existence of biomechanical constraints which simplify the problem of control of multi-segment movements. In addition, it has been hypothesized that movements are controlled using a small set of basic temporal components or activation patterns, shared by several different muscles and reflecting global kinematic and kinetic goals. Here we review recent studies on human locomotion showing that muscle activity is accounted for by a combination of few basic patterns, each one timed at a different phase of the gait cycle. Similar patterns are involved in walking and running at different speeds, walking forwards or backwards, and walking under different loading conditions. The corresponding weights of distribution to different muscles may change as a function of the condition, allowing highly flexible control. Biomechanical correlates of each activation pattern have been described, leading to the hypothesis that the co-ordination of limb and body segments arises from the coupling of neural oscillators between each other and with limb mechanical oscillators. Muscle activations need only intervene during limited time epochs to force intrinsic oscillations of the system when energy is lost. PMID:22411012

  17. Perceptual tests of rhythmic similarity: I. Mora rhythm.

    PubMed

    Murty, Lalita; Otake, Takashi; Cutler, Anne

    2007-01-01

    Listeners rely on native-language rhythm in segmenting speech; in different languages, stress-, syllable- or mora-based rhythm is exploited. The rhythmic similarity hypothesis holds that where two languages have similar rhythm, listeners of each language should segment their own and the other language similarly. Such similarity in listening was previously observed only for related languages (English-Dutch; French-Spanish). We now report three experiments in which speakers of Telugu, a Dravidian language unrelated to Japanese but similar to it in crucial aspects of rhythmic structure, heard speech in Japanese and in their own language, and Japanese listeners heard Telugu. For the Telugu listeners, detection of target sequences in Japanese speech was harder when target boundaries mismatched mora boundaries, exactly the pattern that Japanese listeners earlier exhibited with Japanese and other languages. The same results appeared when Japanese listeners heard Telugu speech containing only codas permissible in Japanese. Telugu listeners' results with Telugu speech were mixed, but the overall pattern revealed correspondences between the response patterns of the two listener groups, as predicted by the rhythmic similarity hypothesis. Telugu and Japanese listeners appear to command similar procedures for speech segmentation, further bolstering the proposal that aspects of language phonological structure affect listeners' speech segmentation.

  18. Drug repositioning by applying 'expression profiles' generated by integrating chemical structure similarity and gene semantic similarity.

    PubMed

    Tan, Fujian; Yang, Ruizhi; Xu, Xiaoxue; Chen, Xiujie; Wang, Yunfeng; Ma, Hongzhe; Liu, Xiangqiong; Wu, Xin; Chen, Yuelong; Liu, Lei; Jia, Xiaodong

    2014-05-01

    Drug repositioning, also known as drug repurposing or reprofiling, is the process of finding new indications for established drugs. Because drug repositioning can reduce costs and enhance the efficiency of drug development, it is of paramount importance in medical research. Here, we present a systematic computational method to identify potential novel indications for a given drug. This method utilizes some prior knowledge such as 3D drug chemical structure information, drug-target interactions and gene semantic similarity information. Its prediction is based on another form of 'expression profile', which contains scores ranging from -1 to 1, reflecting the consensus response scores (CRSs) between each drug of 965 and 1560 proteins. The CRS integrates chemical structure similarity and gene semantic similarity information. We define the degree of similarity between two drugs as the absolute value of their correlation coefficients. Finally, we establish a drug similarity network (DSN) and obtain 33 modules of drugs with similar modes of action, determining their common indications. Using these modules, we predict new indications for 143 drugs and identify previously unknown indications for 42 drugs without ATC codes. This method overcomes the instability of gene expression profiling derived from experiments due to experimental conditions, and predicts indications for a new compound feasibly, requiring only the 3D structure of the compound. In addition, the high literature validation rate of 71.8% also suggests that our method has the potential to discover novel drug indications for existing drugs.

  19. Host ontogeny and the temporal decay of similarity in parasite communities of marine fish.

    PubMed

    Timi, Juan T; Luque, José L; Poulin, Robert

    2010-07-01

    Geographical distances between host populations are key determinants of how many parasite species they share. In principle, decay in similarity should also occur with increasing distance along any other dimension that characterizes some form of separation between communities. Here, we apply the biogeographical concept of distance decay in similarity to ontogenetic changes in the metazoan parasite communities of three species of marine fish from the Atlantic coast of South America. Using differences in body length between all possible pairs of size classes as measures of ontogenetic distances, we find that, using an index of similarity (Bray-Curtis) that takes into account the abundance of each parasite species, the similarity in parasite communities showed a very clear decay pattern; using an index (Jaccard) based on presence/absence of species only, we obtained slightly weaker but nevertheless similar patterns. As we predicted, the slope of the decay relationship was significantly steeper in the fish Cynoscion guatucupa, which goes through clear ontogenetic changes in diet and therefore in exposure to parasites, than in the other species, Engraulis anchoita and Micropogonias furnieri, which maintain a roughly similar diet throughout their lives. In addition, we found that for any given ontogenetic distance, i.e. for a given length difference between two size classes, the similarity in parasite communities was almost always higher if they were adult size classes, and almost always lower if they were juvenile size classes. This, combined with comparisons among individual fish within size classes, shows that parasite communities in juvenile fish are variable and subject to stochastic effects. We propose the distance decay approach as a rigorous and quantitative method to measure rates of community change as a function of host age, and for comparisons across host species to elucidate the role of host ecology in the development of parasite assemblages.

  20. Similar and Additive Effects of Ovariectomy and Diabetes on Insulin Resistance and Lipid Metabolism

    PubMed Central

    Tawfik, Shady H.; Mahmoud, Bothaina F.; Saad, Mohamed I.; Shehata, Mona; Kamel, Maher A.; Helmy, Madiha H.

    2015-01-01

    Type 2 diabetes mellitus (T2DM) is among the leading causes of death in postmenopausal women. The disruption of ovarian function may contribute to the incidence of T2DM. The purpose of this study was to investigate the effects of ovariectomy and T2DM on glucose and lipid homeostasis, perilipin levels in adipose tissues, as a lipolytic regulator, and levels of certain adipokines. Ovariectomized (OVX) rats were used as a model for postmenopausal women. The study was performed on sham, OVX, sham diabetic, and OVX diabetic female rats. The results indicated that ovariectomy alters adipose tissue metabolism through reducing perilipin content in white adipose tissue (WAT); however it has no effect on perilipin level in brown adipose tissue (BAT). OVX diabetic females suffer from serious metabolic disturbances, suggested by exacerbation of insulin resistance in terms of disrupted lipid profile, higher HOMA-IR, hyperinsulinemia, higher leptin, and lower adiponectin concentrations. These metabolic derangements may underlie the predisposition for cardiovascular disease in women after menopause. Therefore, for efficient treatment, the menopausal status of diabetic female should be addressed, and the order of events is of great importance because ovariectomy following development of diabetes has more serious complications compared to development of diabetes as result of menopause. PMID:25834745

  1. Lingos, finite state machines, and fast similarity searching.

    PubMed

    Grant, J Andrew; Haigh, James A; Pickup, Barry T; Nicholls, Anthony; Sayle, Roger A

    2006-01-01

    We apply a recently published method of text-based molecular similarity searching (LINGO) to standard data sets for the purpose of quantifying the accuracy of the approach. Our implementation is based on a pattern-matching finite state machine (FSM) which results in fast search times. The accuracy of LINGO is demonstrated to be comparable to that of a path-based fingerprint and offers a simple yet effective method for similarity searching.

  2. Medical practices display power law behaviors similar to spoken languages

    PubMed Central

    2013-01-01

    Background Medical care commonly involves the apprehension of complex patterns of patient derangements to which the practitioner responds with patterns of interventions, as opposed to single therapeutic maneuvers. This complexity renders the objective assessment of practice patterns using conventional statistical approaches difficult. Methods Combinatorial approaches drawn from symbolic dynamics are used to encode the observed patterns of patient derangement and associated practitioner response patterns as sequences of symbols. Concatenating each patient derangement symbol with the contemporaneous practitioner response symbol creates “words” encoding the simultaneous patient derangement and provider response patterns and yields an observed vocabulary with quantifiable statistical characteristics. Results A fundamental observation in many natural languages is the existence of a power law relationship between the rank order of word usage and the absolute frequency with which particular words are uttered. We show that population level patterns of patient derangement: practitioner intervention word usage in two entirely unrelated domains of medical care display power law relationships similar to those of natural languages, and that–in one of these domains–power law behavior at the population level reflects power law behavior at the level of individual practitioners. Conclusions Our results suggest that patterns of medical care can be approached using quantitative linguistic techniques, a finding that has implications for the assessment of expertise, machine learning identification of optimal practices, and construction of bedside decision support tools. PMID:24007376

  3. An Examination of Similarity Neighbourhoods in Young Children's Receptive Vocabularies.

    ERIC Educational Resources Information Center

    Charles-Luce, Jan; Luce, Paul A.

    1995-01-01

    Examines issues relating to similarity neighborhoods of words in children's lexicons. Young children's receptive vocabularies were analyzed for three-phoneme, four-phoneme and five-phoneme words. The pattern of the original results from Charles-Luce & Luce (1990) was replicated. (18 references) (Author/CK)

  4. Spouse similarity for IQ and personality and convergence.

    PubMed

    Mascie-Taylor, C G

    1989-03-01

    A similar pattern of spousal association for IQ scores and personality traits was found in two British samples from Oxford and Cambridge. There was no indirect evidence from either sample to suggest that convergence occurred during marriage. All observed assortative mating might well be due to initial assortment.

  5. Additive manufacturing of hybrid circuits

    SciTech Connect

    Bell, Nelson S.; Sarobol, Pylin; Cook, Adam; Clem, Paul G.; Keicher, David M.; Hirschfeld, Deidre; Hall, Aaron Christopher

    2016-03-26

    There is a rising interest in developing functional electronics using additively manufactured components. Considerations in materials selection and pathways to forming hybrid circuits and devices must demonstrate useful electronic function; must enable integration; and must complement the complex shape, low cost, high volume, and high functionality of structural but generally electronically passive additively manufactured components. This article reviews several emerging technologies being used in industry and research/development to provide integration advantages of fabricating multilayer hybrid circuits or devices. First, we review a maskless, noncontact, direct write (DW) technology that excels in the deposition of metallic colloid inks for electrical interconnects. Second, we review a complementary technology, aerosol deposition (AD), which excels in the deposition of metallic and ceramic powder as consolidated, thick conformal coatings and is additionally patternable through masking. As a result, we show examples of hybrid circuits/devices integrated beyond 2-D planes, using combinations of DW or AD processes and conventional, established processes.

  6. FRESCO: Referential compression of highly similar sequences.

    PubMed

    Wandelt, Sebastian; Leser, Ulf

    2013-01-01

    In many applications, sets of similar texts or sequences are of high importance. Prominent examples are revision histories of documents or genomic sequences. Modern high-throughput sequencing technologies are able to generate DNA sequences at an ever-increasing rate. In parallel to the decreasing experimental time and cost necessary to produce DNA sequences, computational requirements for analysis and storage of the sequences are steeply increasing. Compression is a key technology to deal with this challenge. Recently, referential compression schemes, storing only the differences between a to-be-compressed input and a known reference sequence, gained a lot of interest in this field. In this paper, we propose a general open-source framework to compress large amounts of biological sequence data called Framework for REferential Sequence COmpression (FRESCO). Our basic compression algorithm is shown to be one to two orders of magnitudes faster than comparable related work, while achieving similar compression ratios. We also propose several techniques to further increase compression ratios, while still retaining the advantage in speed: 1) selecting a good reference sequence; and 2) rewriting a reference sequence to allow for better compression. In addition,we propose a new way of further boosting the compression ratios by applying referential compression to already referentially compressed files (second-order compression). This technique allows for compression ratios way beyond state of the art, for instance,4,000:1 and higher for human genomes. We evaluate our algorithms on a large data set from three different species (more than 1,000 genomes, more than 3 TB) and on a collection of versions of Wikipedia pages. Our results show that real-time compression of highly similar sequences at high compression ratios is possible on modern hardware.

  7. A Model-Based Approach to Constructing Music Similarity Functions

    NASA Astrophysics Data System (ADS)

    West, Kris; Lamere, Paul

    2006-12-01

    Several authors have presented systems that estimate the audio similarity of two pieces of music through the calculation of a distance metric, such as the Euclidean distance, between spectral features calculated from the audio, related to the timbre or pitch of the signal. These features can be augmented with other, temporally or rhythmically based features such as zero-crossing rates, beat histograms, or fluctuation patterns to form a more well-rounded music similarity function. It is our contention that perceptual or cultural labels, such as the genre, style, or emotion of the music, are also very important features in the perception of music. These labels help to define complex regions of similarity within the available feature spaces. We demonstrate a machine-learning-based approach to the construction of a similarity metric, which uses this contextual information to project the calculated features into an intermediate space where a music similarity function that incorporates some of the cultural information may be calculated.

  8. Personality Trait Similarity Between Spouses in Four Cultures

    PubMed Central

    Martin, Thomas A.; H⊆ebí ková, Martina; Urbánek, Tomáš; Boomsma, Dorret I.; Willemsen, Gonneke; Costa, Paul T.

    2008-01-01

    We examined patterns of trait similarity (assortative mating) in married couples in four cultures, using both self-reports and spouse ratings on versions of the Revised NEO Personality Inventory. There was evidence of a subtle but pervasive perceived contrast bias in the spouse rating data. However, there was strong agreement across methods of assessment and moderate agreement across cultures in the pattern of results. Most assortment effects were small, but correlations exceeding .40 were seen for a subset of traits, chiefly from the Openness and Agreeableness domains. Except in Russia, where more positive assortment was seen for younger couples, comparisons of younger and older cohorts showed little systematic difference. This suggested that mate selection, rather than convergence over time, accounted for similarity. Future research on personality similarity in dyads can utilize different designs, but should assess personality at both domain and the facet levels. PMID:18665894

  9. Food additives and preschool children.

    PubMed

    Martyn, Danika M; McNulty, Breige A; Nugent, Anne P; Gibney, Michael J

    2013-02-01

    Food additives have been used throughout history to perform specific functions in foods. A comprehensive framework of legislation is in place within Europe to control the use of additives in the food supply and ensure they pose no risk to human health. Further to this, exposure assessments are regularly carried out to monitor population intakes and verify that intakes are not above acceptable levels (acceptable daily intakes). Young children may have a higher dietary exposure to chemicals than adults due to a combination of rapid growth rates and distinct food intake patterns. For this reason, exposure assessments are particularly important in this age group. The paper will review the use of additives and exposure assessment methods and examine factors that affect dietary exposure by young children. One of the most widely investigated unfavourable health effects associated with food additive intake in preschool-aged children are suggested adverse behavioural effects. Research that has examined this relationship has reported a variety of responses, with many noting an increase in hyperactivity as reported by parents but not when assessed using objective examiners. This review has examined the experimental approaches used in such studies and suggests that efforts are needed to standardise objective methods of measuring behaviour in preschool children. Further to this, a more holistic approach to examining food additive intakes by preschool children is advisable, where overall exposure is considered rather than focusing solely on behavioural effects and possibly examining intakes of food additives other than food colours.

  10. CD measurement point extraction from local dense patterns

    NASA Astrophysics Data System (ADS)

    Miyajima, Masaaki; Matsumoto, Hiroyuki; Takeuchi, Kanji; Naoe, Mitsufumi; Hosono, Koji; Miyauchi, Toru

    2015-07-01

    Precision control of critical dimensions (CD) in modern photomask manufacturing is conventionally accomplished by measuring of CD check patterns allocated inside photomask area. Recently, due to use of immersion and High-NA processes for ArF scanners surface of photomask is subjected to higher energy exposure. Such high energy exposure not only increases the loading effect and the flare but also brings about additional issues such as Cr migration and degradation of MoSi film quality due to its surface oxidation which become a new source of CD deviation. Such phenomenon influence both local pattern shape and its dependence on pattern density and global pattern density and arrangement. To achieve good control of CD in such global environment it is required to measure patterns in the chip device area equivalent to CD check patterns allocated on that chip. However, it is extremely difficult to accurately extract coordinates of patterns for CD measurements inside large device of the chip. We have developed a system in which firstly, using design rule check (DRC) method we extract from the chip device area simple line and space (L/S) patterns similar to CD check patterns and secondly, after bitmap transformation of the extraction result use a convolution operation approach to determine the patterns to measure. We confirmed that our method enables selection of CD measurement points with good reproducibility and stability. Next, we report on details of our method to extract CD measurement points and demonstrate its usefulness due to its excellent reproducibility and stability.

  11. Polyimide processing additives

    NASA Technical Reports Server (NTRS)

    Pratt, J. R.; St. Clair, T. L.; Burks, H. D.; Stoakley, D. M.

    1987-01-01

    A method has been found for enhancing the melt flow of thermoplastic polyimides during processing. A high molecular weight 422 copoly(amic acid) or copolyimide was fused with approximately 0.05 to 5 pct by weight of a low molecular weight amic acid or imide additive, and this melt was studied by capillary rheometry. Excellent flow and improved composite properties on graphite resulted from the addition of a PMDA-aniline additive to LARC-TPI. Solution viscosity studies imply that amic acid additives temporarily lower molecular weight and, hence, enlarge the processing window. Thus, compositions containing the additive have a lower melt viscosity for a longer time than those unmodified.

  12. [Food additives and healthiness].

    PubMed

    Heinonen, Marina

    2014-01-01

    Additives are used for improving food structure or preventing its spoilage, for example. Many substances used as additives are also naturally present in food. The safety of additives is evaluated according to commonly agreed principles. If high concentrations of an additive cause adverse health effects for humans, a limit of acceptable daily intake (ADI) is set for it. An additive is a risk only when ADI is exceeded. The healthiness of food is measured on the basis of nutrient density and scientifically proven effects.

  13. Beyond Literal Similarity. Technical Report No. 105.

    ERIC Educational Resources Information Center

    Ortony, Andrew

    Hitherto, theories of similarity have restricted themselves to judgments of what might be called literal similarity. A central thesis of this paper is that a complete account of similarity needs also to be sensitive to nonliteralness, or metaphoricity, an aspect of similarity statements that is most evident in similes, but that actually underlies…

  14. Study and response time for the visual recognition of 'similarity' and identity

    NASA Technical Reports Server (NTRS)

    Derks, P. L.; Bauer, T. M.

    1974-01-01

    Four subjects compared successively presented pairs of line patterns for a match between any lines in the pattern (similarity) and for a match between all lines (identity). The encoding or study times for pattern recognition from immediate memory and the latency in responses to comparison stimuli were examined. Qualitative differences within and between subjects were most evident in study times.

  15. Perceptual similarity of regional dialects of American English

    PubMed Central

    Clopper, Cynthia G.; Levi, Susannah V.; Pisoni, David B.

    2012-01-01

    Previous research on the perception of dialect variation has measured the perceptual similarity of talkers based on regional dialect using only indirect methods. In the present study, a paired comparison similarity ratings task was used to obtain direct measures of perceptual similarity. Naive listeners were asked to make explicit judgments about the similarity of a set of talkers based on regional dialect. The talkers represented four regional varieties of American English and both genders. Results revealed an additive effect of gender and dialect on mean similarity ratings and two primary dimensions of perceptual dialect similarity: geography (northern versus southern varieties) and dialect markedness (many versus few characteristic properties). The present findings are consistent with earlier research on the perception of dialect variation, as well as recent speech perception studies which demonstrate the integral role of talker gender in speech perception. PMID:16454310

  16. Semantic similarity measure in biomedical domain leverage web search engine.

    PubMed

    Chen, Chi-Huang; Hsieh, Sheau-Ling; Weng, Yung-Ching; Chang, Wen-Yung; Lai, Feipei

    2010-01-01

    Semantic similarity measure plays an essential role in Information Retrieval and Natural Language Processing. In this paper we propose a page-count-based semantic similarity measure and apply it in biomedical domains. Previous researches in semantic web related applications have deployed various semantic similarity measures. Despite the usefulness of the measurements in those applications, measuring semantic similarity between two terms remains a challenge task. The proposed method exploits page counts returned by the Web Search Engine. We define various similarity scores for two given terms P and Q, using the page counts for querying P, Q and P AND Q. Moreover, we propose a novel approach to compute semantic similarity using lexico-syntactic patterns with page counts. These different similarity scores are integrated adapting support vector machines, to leverage the robustness of semantic similarity measures. Experimental results on two datasets achieve correlation coefficients of 0.798 on the dataset provided by A. Hliaoutakis, 0.705 on the dataset provide by T. Pedersen with physician scores and 0.496 on the dataset provided by T. Pedersen et al. with expert scores.

  17. Foam patterns

    DOEpatents

    Chaudhry, Anil R; Dzugan, Robert; Harrington, Richard M; Neece, Faurice D; Singh, Nipendra P; Westendorf, Travis

    2013-11-26

    A method of creating a foam pattern comprises mixing a polyol component and an isocyanate component to form a liquid mixture. The method further comprises placing a temporary core having a shape corresponding to a desired internal feature in a cavity of a mold and inserting the mixture into the cavity of the mold so that the mixture surrounds a portion of the temporary core. The method optionally further comprises using supporting pins made of foam to support the core in the mold cavity, with such pins becoming integral part of the pattern material simplifying subsequent processing. The method further comprises waiting for a predetermined time sufficient for a reaction from the mixture to form a foam pattern structure corresponding to the cavity of the mold, wherein the foam pattern structure encloses a portion of the temporary core and removing the temporary core from the pattern independent of chemical leaching.

  18. Similarity interaction in information-theoretic self-organizing maps

    NASA Astrophysics Data System (ADS)

    Kamimura, Ryotaro

    2013-04-01

    In this paper, we propose a new information-theoretic computational method called 'similarity interaction' for improving visualization. Due to the fixed arrangement of neurons in the self-organizing maps, similarity between neurons is not necessarily a faithful representation of the actual similarity between neurons. To relax the fixed arrangement, we introduce a method called 'similarity interaction', because we integrate the information of connection weights into that of neurons. We applied our method to three problems, namely teaching assistant evaluation, automobile data, and dermatology data. In all three problems, we succeeded in demonstrating the better performance of our method through visual inspection and quantitative evaluation. Our method is the first step towards the interaction of multiple components in a neural network for finer representations of input patterns.

  19. Innate Visual Learning through Spontaneous Activity Patterns

    PubMed Central

    Albert, Mark V.; Schnabel, Adam; Field, David J.

    2008-01-01

    Patterns of spontaneous activity in the developing retina, LGN, and cortex are necessary for the proper development of visual cortex. With these patterns intact, the primary visual cortices of many newborn animals develop properties similar to those of the adult cortex but without the training benefit of visual experience. Previous models have demonstrated how V1 responses can be initialized through mechanisms specific to development and prior to visual experience, such as using axonal guidance cues or relying on simple, pairwise correlations on spontaneous activity with additional developmental constraints. We argue that these spontaneous patterns may be better understood as part of an “innate learning” strategy, which learns similarly on activity both before and during visual experience. With an abstraction of spontaneous activity models, we show how the visual system may be able to bootstrap an efficient code for its natural environment prior to external visual experience, and we continue the same refinement strategy upon natural experience. The patterns are generated through simple, local interactions and contain the same relevant statistical properties of retinal waves and hypothesized waves in the LGN and V1. An efficient encoding of these patterns resembles a sparse coding of natural images by producing neurons with localized, oriented, bandpass structure—the same code found in early visual cortical cells. We address the relevance of higher-order statistical properties of spontaneous activity, how this relates to a system that may adapt similarly on activity prior to and during natural experience, and how these concepts ultimately relate to an efficient coding of our natural world. PMID:18670593

  20. Reconstructing propagation networks with temporal similarity

    PubMed Central

    Liao, Hao; Zeng, An

    2015-01-01

    Node similarity significantly contributes to the growth of real networks. In this paper, based on the observed epidemic spreading results we apply the node similarity metrics to reconstruct the underlying networks hosting the propagation. We find that the reconstruction accuracy of the similarity metrics is strongly influenced by the infection rate of the spreading process. Moreover, there is a range of infection rate in which the reconstruction accuracy of some similarity metrics drops nearly to zero. To improve the similarity-based reconstruction method, we propose a temporal similarity metric which takes into account the time information of the spreading. The reconstruction results are remarkably improved with the new method. PMID:26086198

  1. Reconstructing propagation networks with temporal similarity.

    PubMed

    Liao, Hao; Zeng, An

    2015-06-18

    Node similarity significantly contributes to the growth of real networks. In this paper, based on the observed epidemic spreading results we apply the node similarity metrics to reconstruct the underlying networks hosting the propagation. We find that the reconstruction accuracy of the similarity metrics is strongly influenced by the infection rate of the spreading process. Moreover, there is a range of infection rate in which the reconstruction accuracy of some similarity metrics drops nearly to zero. To improve the similarity-based reconstruction method, we propose a temporal similarity metric which takes into account the time information of the spreading. The reconstruction results are remarkably improved with the new method.

  2. Polylactides in additive biomanufacturing.

    PubMed

    Poh, Patrina S P; Chhaya, Mohit P; Wunner, Felix M; De-Juan-Pardo, Elena M; Schilling, Arndt F; Schantz, Jan-Thorsten; van Griensven, Martijn; Hutmacher, Dietmar W

    2016-12-15

    New advanced manufacturing technologies under the alias of additive biomanufacturing allow the design and fabrication of a range of products from pre-operative models, cutting guides and medical devices to scaffolds. The process of printing in 3 dimensions of cells, extracellular matrix (ECM) and biomaterials (bioinks, powders, etc.) to generate in vitro and/or in vivo tissue analogue structures has been termed bioprinting. To further advance in additive biomanufacturing, there are many aspects that we can learn from the wider additive manufacturing (AM) industry, which have progressed tremendously since its introduction into the manufacturing sector. First, this review gives an overview of additive manufacturing and both industry and academia efforts in addressing specific challenges in the AM technologies to drive toward AM-enabled industrial revolution. After which, considerations of poly(lactides) as a biomaterial in additive biomanufacturing are discussed. Challenges in wider additive biomanufacturing field are discussed in terms of (a) biomaterials; (b) computer-aided design, engineering and manufacturing; (c) AM and additive biomanufacturing printers hardware; and (d) system integration. Finally, the outlook for additive biomanufacturing was discussed.

  3. Additive Manufactured Product Integrity

    NASA Technical Reports Server (NTRS)

    Waller, Jess; Wells, Doug; James, Steve; Nichols, Charles

    2017-01-01

    NASA is providing key leadership in an international effort linking NASA and non-NASA resources to speed adoption of additive manufacturing (AM) to meet NASA's mission goals. Participants include industry, NASA's space partners, other government agencies, standards organizations and academia. Nondestructive Evaluation (NDE) is identified as a universal need for all aspects of additive manufacturing.

  4. Similar resilience attributes in lakes with different management practices

    USGS Publications Warehouse

    Baho, Didier L.; Drakare, Stina; Johnson, Richard K.; Allen, Craig R.; Angeler, David G.

    2014-01-01

    Liming has been used extensively in Scandinavia and elsewhere since the 1970s to counteract the negative effects of acidification. Communities in limed lakes usually return to acidified conditions once liming is discontinued, suggesting that liming is unlikely to shift acidified lakes to a state equivalent to pre-acidification conditions that requires no further management intervention. While this suggests a low resilience of limed lakes, attributes that confer resilience have not been assessed, limiting our understanding of the efficiency of costly management programs. In this study, we assessed community metrics (diversity, richness, evenness, biovolume), multivariate community structure and the relative resilience of phytoplankton in limed, acidified and circum-neutral lakes from 1997 to 2009, using multivariate time series modeling. We identified dominant temporal frequencies in the data, allowing us to track community change at distinct temporal scales. We assessed two attributes of relative resilience (cross-scale and within-scale structure) of the phytoplankton communities, based on the fluctuation frequency patterns identified. We also assessed species with stochastic temporal dynamics. Liming increased phytoplankton diversity and richness; however, multivariate community structure differed in limed relative to acidified and circum-neutral lakes. Cross-scale and within-scale attributes of resilience were similar across all lakes studied but the contribution of those species exhibiting stochastic dynamics was higher in the acidified and limed compared to circum-neutral lakes. From a resilience perspective, our results suggest that limed lakes comprise a particular condition of an acidified lake state. This explains why liming does not move acidified lakes out of a “degraded” basin of attraction. In addition, our study demonstrates the potential of time series modeling to assess the efficiency of restoration and management outcomes through quantification

  5. Similar resilience attributes in lakes with different management practices.

    PubMed

    Baho, Didier L; Drakare, Stina; Johnson, Richard K; Allen, Craig R; Angeler, David G

    2014-01-01

    Liming has been used extensively in Scandinavia and elsewhere since the 1970s to counteract the negative effects of acidification. Communities in limed lakes usually return to acidified conditions once liming is discontinued, suggesting that liming is unlikely to shift acidified lakes to a state equivalent to pre-acidification conditions that requires no further management intervention. While this suggests a low resilience of limed lakes, attributes that confer resilience have not been assessed, limiting our understanding of the efficiency of costly management programs. In this study, we assessed community metrics (diversity, richness, evenness, biovolume), multivariate community structure and the relative resilience of phytoplankton in limed, acidified and circum-neutral lakes from 1997 to 2009, using multivariate time series modeling. We identified dominant temporal frequencies in the data, allowing us to track community change at distinct temporal scales. We assessed two attributes of relative resilience (cross-scale and within-scale structure) of the phytoplankton communities, based on the fluctuation frequency patterns identified. We also assessed species with stochastic temporal dynamics. Liming increased phytoplankton diversity and richness; however, multivariate community structure differed in limed relative to acidified and circum-neutral lakes. Cross-scale and within-scale attributes of resilience were similar across all lakes studied but the contribution of those species exhibiting stochastic dynamics was higher in the acidified and limed compared to circum-neutral lakes. From a resilience perspective, our results suggest that limed lakes comprise a particular condition of an acidified lake state. This explains why liming does not move acidified lakes out of a "degraded" basin of attraction. In addition, our study demonstrates the potential of time series modeling to assess the efficiency of restoration and management outcomes through quantification of

  6. Similar Motor Cortical Control Mechanisms for Precise Limb Control during Reaching and Locomotion

    PubMed Central

    Yakovenko, Sergiy

    2015-01-01

    Throughout the course of evolution there has been a parallel development of the complexity and flexibility of the nervous system and the skeletomuscular system that it controls. This development is particularly evident for the cerebral cortical areas and the transformation of the use of the upper limbs from a purely locomotor function to one including, or restricted to, reaching and grasping. This study addresses the issue of whether the control of reaching has involved the development of new cortical circuits or whether the same neurons are used to control both locomotion and reaching. We recorded the activity of pyramidal tract neurons in the motor cortex of the cat both during voluntary gait modifications and during reaching. All cells showed generally similar patterns of activity in both tasks. More specifically, we showed that, in many cases, cells maintained a constant temporal relationship to the activity of synergistic muscle groups in each task. In addition, in some cells the relationship between the intensity of the cell discharge activity and the magnitude of the EMG activity was equally constant during gait modifications and reaching. As such, the results are compatible with the hypothesis that the corticospinal circuits used to control reaching evolved from those used to precisely modify gait. SIGNIFICANCE STATEMENT In an article in 1989, Georgopoulos and Grillner (1989) proposed that the corticospinal control mechanisms used for reaching movements in primates may have evolved from those used to control precise modifications of gait during quadrupedal locomotion. In this article, we provide a test of this hypothesis by recording the activity of individual motor cortical cells during both behaviors. Our results are compatible with the hypothesis in that they demonstrate that individual cortical neurons exhibit similar qualitative and quantitative patterns during each behavior. Beyond a general similarity of activity patterns, we show that some cortical

  7. Voxel similarity measures for automated image registration

    NASA Astrophysics Data System (ADS)

    Hill, Derek L.; Studholme, Colin; Hawkes, David J.

    1994-09-01

    We present the concept of the feature space sequence: 2D distributions of voxel features of two images generated at registration and a sequence of misregistrations. We provide an explanation of the structure seen in these images. Feature space sequences have been generated for a pair of MR image volumes identical apart from the addition of Gaussian noise to one, MR image volumes with and without Gadolinium enhancement, MR and PET-FDG image volumes and MR and CT image volumes, all of the head. The structure seen in the feature space sequences was used to devise two new measures of similarity which in turn were used to produce plots of cost versus misregistration for the 6 degrees of freedom of rigid body motion. One of these, the third order moment of the feature space histogram, was used to register the MR image volumes with and without Gadolinium enhancement. These techniques have the potential for registration accuracy to within a small fraction of a voxel or resolution element and therefore interpolation errors in image transformation can be the dominant source of error in subtracted images. We present a method for removing these errors using sinc interpolation and show how interpolation errors can be reduced by over two orders of magnitude.

  8. A Distance and Angle Similarity Measure Method.

    ERIC Educational Resources Information Center

    Zhang, Jin; Korfhage, Robert R.

    1999-01-01

    Discusses similarity measures that are used in information retrieval to improve precision and recall ratios and presents a combined vector-based distance and angle measure to make similarity measurement more scientific and accurate. Suggests directions for future research. (LRW)

  9. Self-similarity Detection via Multi-scale Image Analysis

    NASA Astrophysics Data System (ADS)

    Kamejima, Kohji

    A dynamic scheme is presented for generating multi-scale images associated with self-similar patterns. By blurring with a small scale parameter, brightness distributions are extended to geometrically singular fractal patterns. Through weighted averaging with respect to scale factors, a multi-scale image is generated as a representation of the conditional probability for capturing unknown attractors. The local structure of the multi-scale image is analyzed to demonstrate the structural consistency of the capturing probability with respect to the imaging process associated with the attractor. By extracting stochastic features based on the capturing probability, a computational scheme is introduced for matching observed attractors with a preassigned dictionary of patterns. Proposed method was verified by simulation studies.

  10. Learning, memory and exploratory similarities in genetically identical cloned dogs

    PubMed Central

    Shin, Chi Won; Kim, Geon A; Park, Won Jun; Park, Kwan Yong; Jeon, Jeong Min; Oh, Hyun Ju; Kim, Min Jung

    2016-01-01

    Somatic cell nuclear transfer allows generation of genetically identical animals using donor cells derived from animals with particular traits. To date, few studies have investigated whether or not these cloned dogs will show identical behavior patterns. To address this question, learning, memory and exploratory patterns were examined using six cloned dogs with identical nuclear genomes. The variance of total incorrect choice number in the Y-maze test among cloned dogs was significantly lower than that of the control dogs. There was also a significant decrease in variance in the level of exploratory activity in the open fields test compared to age-matched control dogs. These results indicate that cloned dogs show similar cognitive and exploratory patterns, suggesting that these behavioral phenotypes are related to the genotypes of the individuals. PMID:27030191

  11. Learning, memory and exploratory similarities in genetically identical cloned dogs.

    PubMed

    Shin, Chi Won; Kim, Geon A; Park, Won Jun; Park, Kwan Yong; Jeon, Jeong Min; Oh, Hyun Ju; Kim, Min Jung; Lee, Byeong Chun

    2016-12-30

    Somatic cell nuclear transfer allows generation of genetically identical animals using donor cells derived from animals with particular traits. To date, few studies have investigated whether or not these cloned dogs will show identical behavior patterns. To address this question, learning, memory and exploratory patterns were examined using six cloned dogs with identical nuclear genomes. The variance of total incorrect choice number in the Y-maze test among cloned dogs was significantly lower than that of the control dogs. There was also a significant decrease in variance in the level of exploratory activity in the open fields test compared to age-matched control dogs. These results indicate that cloned dogs show similar cognitive and exploratory patterns, suggesting that these behavioral phenotypes are related to the genotypes of the individuals.

  12. On Identifying Useful Patterns to Analyze Products in Retail Transaction Databases

    NASA Astrophysics Data System (ADS)

    Yun, Unil

    Mining correlated patterns in large transaction databases is one of the essential tasks in data mining since a huge number of patterns are usually mined, but it is hard to find patterns with the correlation. The needed data analysis should be made according to the requirements of the particular real application. In previous mining approaches, patterns with the weak affinity are found even with a high minimum support. In this paper, we suggest weighted support affinity pattern mining in which a new measure, weighted support confidence (ws-confidence) is developed to identify correlated patterns with the weighted support affinity. To efficiently prune the weak affinity patterns, we prove that the ws-confidence measure satisfies the anti-monotone and cross weighted support properties which can be applied to eliminate patterns with dissimilar weighted support levels. Based on the two properties, we develop a weighted support affinity pattern mining algorithm (WSP). The weighted support affinity patterns can be useful to answer the comparative analysis queries such as finding itemsets containing items which give similar total selling expense levels with an acceptable error range α% and detecting item lists with similar levels of total profits. In addition, our performance study shows that WSP is efficient and scalable for mining weighted support affinity patterns.

  13. Thematic Relations Affect Similarity via Commonalities

    ERIC Educational Resources Information Center

    Golonka, Sabrina; Estes, Zachary

    2009-01-01

    Thematic relations are an important source of perceived similarity. For instance, the "rowing" theme of boats and oars increases their perceived similarity. The mechanism of this effect, however, has not been specified previously. The authors investigated whether thematic relations affect similarity by increasing commonalities or by…

  14. Category-based induction from similarity of neural activation.

    PubMed

    Weber, Matthew J; Osherson, Daniel

    2014-03-01

    The idea that similarity might be an engine of inductive inference dates back at least as far as David Hume. However, Hume's thesis is difficult to test without begging the question, since judgments of similarity may be infected by inferential processes. We present a one-parameter model of category-based induction that generates predictions about arbitrary statements of conditional probability over a predicate and a set of items. The prediction is based on the unconditional probabilities and similarities that characterize that predicate and those items. To test Hume's thesis, we collected brain activation from various regions of the ventral visual stream during a categorization task that did not invite comparison of categories. We then calculated the similarity of those activation patterns using a simple measure of vectorwise similarity and supplied those similarities to the model. The model's outputs correlated well with subjects' judgments of conditional probability. Our results represent a promising first step toward confirming Hume's thesis; similarity, assessed without reference to induction, may well drive inductive inference.

  15. Polyimide processing additives

    NASA Technical Reports Server (NTRS)

    Fletcher, James C. (Inventor); Pratt, J. Richard (Inventor); St.clair, Terry L. (Inventor); Stoakley, Diane M. (Inventor); Burks, Harold D. (Inventor)

    1992-01-01

    A process for preparing polyimides having enhanced melt flow properties is described. The process consists of heating a mixture of a high molecular weight poly-(amic acid) or polyimide with a low molecular weight amic acid or imide additive in the range of 0.05 to 15 percent by weight of additive. The polyimide powders so obtained show improved processability, as evidenced by lower melt viscosity by capillary rheometry. Likewise, films prepared from mixtures of polymers with additives show improved processability with earlier onset of stretching by TMA.

  16. Polyimide processing additives

    NASA Technical Reports Server (NTRS)

    Pratt, J. Richard (Inventor); St.clair, Terry L. (Inventor); Stoakley, Diane M. (Inventor); Burks, Harold D. (Inventor)

    1993-01-01

    A process for preparing polyimides having enhanced melt flow properties is described. The process consists of heating a mixture of a high molecular weight poly-(amic acid) or polyimide with a low molecular weight amic acid or imide additive in the range of 0.05 to 15 percent by weight of the additive. The polyimide powders so obtained show improved processability, as evidenced by lower melt viscosity by capillary rheometry. Likewise, films prepared from mixtures of polymers with additives show improved processability with earlier onset of stretching by TMA.

  17. Currents connecting communities: nearshore community similarity and ocean circulation.

    PubMed

    Watson, J R; Hays, C G; Raimondi, P T; Mitarai, S; Dong, C; McWilliams, J C; Blanchette, C A; Caselle, J E; Siegel, D A

    2011-06-01

    Understanding the mechanisms that create spatial heterogeneity in species distributions is fundamental to ecology. For nearshore marine systems, most species have a pelagic larval stage where dispersal is strongly influenced by patterns of ocean circulation. Concomitantly, nearshore habitats and the local environment are also influenced by ocean circulation. Because of the shared dependence on the seascape, distinguishing the relative importance of the local environment from regional patterns of dispersal for community structure remains a challenge. Here, we quantify the "oceanographic distance" and "oceanographic asymmetry" between nearshore sites using ocean circulation modeling results. These novel metrics quantify spatial separation based on realistic patterns of ocean circulation, and we explore their explanatory power for intertidal and subtidal community similarity in the Southern California Bight. We find that these metrics show significant correspondence with patterns of community similarity and that their combined explanatory power exceeds that of the thermal structure of the domain. Our approach identifies the unique influence of ocean circulation on community structure and provides evidence for oceanographically mediated dispersal limitation in nearshore marine communities.

  18. Food Additives and Hyperkinesis

    ERIC Educational Resources Information Center

    Wender, Ester H.

    1977-01-01

    The hypothesis that food additives are causally associated with hyperkinesis and learning disabilities in children is reviewed, and available data are summarized. Available from: American Medical Association 535 North Dearborn Street Chicago, Illinois 60610. (JG)

  19. Smog control fuel additives

    SciTech Connect

    Lundby, W.

    1993-06-29

    A method is described of controlling, reducing or eliminating, ozone and related smog resulting from photochemical reactions between ozone and automotive or industrial gases comprising the addition of iodine or compounds of iodine to hydrocarbon-base fuels prior to or during combustion in an amount of about 1 part iodine per 240 to 10,000,000 parts fuel, by weight, to be accomplished by: (a) the addition of these inhibitors during or after the refining or manufacturing process of liquid fuels; (b) the production of these inhibitors for addition into fuel tanks, such as automotive or industrial tanks; or (c) the addition of these inhibitors into combustion chambers of equipment utilizing solid fuels for the purpose of reducing ozone.

  20. Automation for pattern library creation and in-design optimization

    NASA Astrophysics Data System (ADS)

    Deng, Rock; Zou, Elain; Hong, Sid; Wang, Jinyan; Zhang, Yifan; Sweis, Jason; Lai, Ya-Chieh; Ding, Hua; Huang, Jason

    2015-03-01

    Semiconductor manufacturing technologies are becoming increasingly complex with every passing node. Newer technology nodes are pushing the limits of optical lithography and requiring multiple exposures with exotic material stacks for each critical layer. All of this added complexity usually amounts to further restrictions in what can be designed. Furthermore, the designs must be checked against all these restrictions in verification and sign-off stages. Design rules are intended to capture all the manufacturing limitations such that yield can be maximized for any given design adhering to all the rules. Most manufacturing steps employ some sort of model based simulation which characterizes the behavior of each step. The lithography models play a very big part of the overall yield and design restrictions in patterning. However, lithography models are not practical to run during design creation due to their slow and prohibitive run times. Furthermore, the models are not usually given to foundry customers because of the confidential and sensitive nature of every foundry's processes. The design layout locations where a model flags unacceptable simulated results can be used to define pattern rules which can be shared with customers. With advanced technology nodes we see a large growth of pattern based rules. This is due to the fact that pattern matching is very fast and the rules themselves can be very complex to describe in a standard DRC language. Therefore, the patterns are left as either pattern layout clips or abstracted into pattern-like syntax which a pattern matcher can use directly. The patterns themselves can be multi-layered with "fuzzy" designations such that groups of similar patterns can be found using one description. The pattern matcher is often integrated with a DRC tool such that verification and signoff can be done in one step. The patterns can be layout constructs that are "forbidden", "waived", or simply low-yielding in nature. The patterns can also

  1. Visualizing the spatial gene expression organization in the brain through non-linear similarity embeddings.

    PubMed

    Mahfouz, Ahmed; van de Giessen, Martijn; van der Maaten, Laurens; Huisman, Sjoerd; Reinders, Marcel; Hawrylycz, Michael J; Lelieveldt, Boudewijn P F

    2015-02-01

    The Allen Brain Atlases enable the study of spatially resolved, genome-wide gene expression patterns across the mammalian brain. Several explorative studies have applied linear dimensionality reduction methods such as Principal Component Analysis (PCA) and classical Multi-Dimensional Scaling (cMDS) to gain insight into the spatial organization of these expression patterns. In this paper, we describe a non-linear embedding technique called Barnes-Hut Stochastic Neighbor Embedding (BH-SNE) that emphasizes the local similarity structure of high-dimensional data points. By applying BH-SNE to the gene expression data from the Allen Brain Atlases, we demonstrate the consistency of the 2D, non-linear embedding of the sagittal and coronal mouse brain atlases, and across 6 human brains. In addition, we quantitatively show that BH-SNE maps are superior in their separation of neuroanatomical regions in comparison to PCA and cMDS. Finally, we assess the effect of higher-order principal components on the global structure of the BH-SNE similarity maps. Based on our observations, we conclude that BH-SNE maps with or without prior dimensionality reduction (based on PCA) provide comprehensive and intuitive insights in both the local and global spatial transcriptome structure of the human and mouse Allen Brain Atlases.

  2. MARQ: an online tool to mine GEO for experiments with similar or opposite gene expression signatures.

    PubMed

    Vazquez, Miguel; Nogales-Cadenas, Ruben; Arroyo, Javier; Botías, Pedro; García, Raul; Carazo, Jose M; Tirado, Francisco; Pascual-Montano, Alberto; Carmona-Saez, Pedro

    2010-07-01

    The enormous amount of data available in public gene expression repositories such as Gene Expression Omnibus (GEO) offers an inestimable resource to explore gene expression programs across several organisms and conditions. This information can be used to discover experiments that induce similar or opposite gene expression patterns to a given query, which in turn may lead to the discovery of new relationships among diseases, drugs or pathways, as well as the generation of new hypotheses. In this work, we present MARQ, a web-based application that allows researchers to compare a query set of genes, e.g. a set of over- and under-expressed genes, against a signature database built from GEO datasets for different organisms and platforms. MARQ offers an easy-to-use and integrated environment to mine GEO, in order to identify conditions that induce similar or opposite gene expression patterns to a given experimental condition. MARQ also includes additional functionalities for the exploration of the results, including a meta-analysis pipeline to find genes that are differentially expressed across different experiments. The application is freely available at http://marq.dacya.ucm.es.

  3. Additive manufacturing of hybrid circuits

    DOE PAGES

    Bell, Nelson S.; Sarobol, Pylin; Cook, Adam; ...

    2016-03-26

    There is a rising interest in developing functional electronics using additively manufactured components. Considerations in materials selection and pathways to forming hybrid circuits and devices must demonstrate useful electronic function; must enable integration; and must complement the complex shape, low cost, high volume, and high functionality of structural but generally electronically passive additively manufactured components. This article reviews several emerging technologies being used in industry and research/development to provide integration advantages of fabricating multilayer hybrid circuits or devices. First, we review a maskless, noncontact, direct write (DW) technology that excels in the deposition of metallic colloid inks for electrical interconnects.more » Second, we review a complementary technology, aerosol deposition (AD), which excels in the deposition of metallic and ceramic powder as consolidated, thick conformal coatings and is additionally patternable through masking. As a result, we show examples of hybrid circuits/devices integrated beyond 2-D planes, using combinations of DW or AD processes and conventional, established processes.« less

  4. Clustering rainfall pattern in Malaysia using functional data analysis

    NASA Astrophysics Data System (ADS)

    Hamdan, Muhammad Fauzee; Suhaila, Jamaludin; Jemain, Abdul Aziz

    2015-02-01

    Understanding rainfall pattern is important for planning and prediction in hydrology, meteorology, water planning and agriculture. There are two important features of rainfall: the rainfall amount and the probability of rainfall occurrence. The discrete raw data of rainfall precipitation was reconstructed into rainfall amount curves by using functional data analysis method. Hierarchical clustering method with complete-linkage method was used to search for natural similar groupings of rainfall amount curves. The functional clustering illustrated the four dominant patterns for rainfall amount curves. In additional, adaptive Neyman test showed that each clusters are significantly different with from each others.

  5. Similarity increases altruistic punishment in humans.

    PubMed

    Mussweiler, Thomas; Ockenfels, Axel

    2013-11-26

    Humans are attracted to similar others. As a consequence, social networks are homogeneous in sociodemographic, intrapersonal, and other characteristics--a principle called homophily. Despite abundant evidence showing the importance of interpersonal similarity and homophily for human relationships, their behavioral correlates and cognitive foundations are poorly understood. Here, we show that perceived similarity substantially increases altruistic punishment, a key mechanism underlying human cooperation. We induced (dis)similarity perception by manipulating basic cognitive mechanisms in an economic cooperation game that included a punishment phase. We found that similarity-focused participants were more willing to punish others' uncooperative behavior. This influence of similarity is not explained by group identity, which has the opposite effect on altruistic punishment. Our findings demonstrate that pure similarity promotes reciprocity in ways known to encourage cooperation. At the same time, the increased willingness to punish norm violations among similarity-focused participants provides a rationale for why similar people are more likely to build stable social relationships. Finally, our findings show that altruistic punishment is differentially involved in encouraging cooperation under pure similarity vs. in-group conditions.

  6. Surface-Based Protein Binding Pocket Similarity

    PubMed Central

    Spitzer, Russell; Cleves, Ann E.; Jain, Ajay N.

    2011-01-01

    Protein similarity comparisons may be made on a local or global basis and may consider sequence information or differing levels of structural information. We present a local 3D method that compares protein binding site surfaces in full atomic detail. The approach is based on the morphological similarity method which has been widely applied for global comparison of small molecules. We apply the method to all-by-all comparisons two sets of human protein kinases, a very diverse set of ATP-bound proteins from multiple species, and three heterogeneous benchmark protein binding site data sets. Cases of disagreement between sequence-based similarity and binding site similarity yield informative examples. Where sequence similarity is very low, high pocket similarity can reliably identify important binding motifs. Where sequence similarity is very high, significant differences in pocket similarity are related to ligand binding specificity and similarity. Local protein binding pocket similarity provides qualitatively complementary information to other approaches, and it can yield quantitative information in support of functional annotation. PMID:21769944

  7. Group Sparse Additive Models

    PubMed Central

    Yin, Junming; Chen, Xi; Xing, Eric P.

    2016-01-01

    We consider the problem of sparse variable selection in nonparametric additive models, with the prior knowledge of the structure among the covariates to encourage those variables within a group to be selected jointly. Previous works either study the group sparsity in the parametric setting (e.g., group lasso), or address the problem in the nonparametric setting without exploiting the structural information (e.g., sparse additive models). In this paper, we present a new method, called group sparse additive models (GroupSpAM), which can handle group sparsity in additive models. We generalize the ℓ1/ℓ2 norm to Hilbert spaces as the sparsity-inducing penalty in GroupSpAM. Moreover, we derive a novel thresholding condition for identifying the functional sparsity at the group level, and propose an efficient block coordinate descent algorithm for constructing the estimate. We demonstrate by simulation that GroupSpAM substantially outperforms the competing methods in terms of support recovery and prediction accuracy in additive models, and also conduct a comparative experiment on a real breast cancer dataset.

  8. Additive Manufacturing Infrared Inspection

    NASA Technical Reports Server (NTRS)

    Gaddy, Darrell

    2014-01-01

    Additive manufacturing is a rapid prototyping technology that allows parts to be built in a series of thin layers from plastic, ceramics, and metallics. Metallic additive manufacturing is an emerging form of rapid prototyping that allows complex structures to be built using various metallic powders. Significant time and cost savings have also been observed using the metallic additive manufacturing compared with traditional techniques. Development of the metallic additive manufacturing technology has advanced significantly over the last decade, although many of the techniques to inspect parts made from these processes have not advanced significantly or have limitations. Several external geometry inspection techniques exist such as Coordinate Measurement Machines (CMM), Laser Scanners, Structured Light Scanning Systems, or even traditional calipers and gages. All of the aforementioned techniques are limited to external geometry and contours or must use a contact probe to inspect limited internal dimensions. This presentation will document the development of a process for real-time dimensional inspection technique and digital quality record of the additive manufacturing process using Infrared camera imaging and processing techniques.

  9. Similarities between cysteinesulphinate transaminase and aspartate aminotransferase.

    PubMed

    Recasens, M; Mandel, P

    1979-01-01

    A method for the purification of two cysteinesulphinate transaminases, A and B (EC 2.6.1), is described. These enzymes catalyse the conversion of cysteinesulphinic acid to beta-sulphinyl pyruvate. The final preparations are homogeneous by polyacrylamide gel electrophoresis, sodium dodecyl sulphate-polyacrylamide gel electrophoresis and isoelectrofocusing. The molecular weight of the subunits is 41 000 for cysteinesulphinate transaminase A and 43 400 for B. Both enzymes are unspecific, as L-asparate, L-glutamate and L-cysteic acid serve as substrates in addition to L-cysteinesulphinic acid. Cysteinesulphinate transaminase A has a Km of 9.8 mM for cysteinesulphinic acid and 0.25 mM for aspartic acid, whereas the B enzyme has a Km of 6.5 mM for cysteinesulphinic acid and 1.4 mM for aspartic acid. The Vmax values of the A and B enzymes are respectively 7.1 and 6.2 mmol h-1 mg-1 protein for aspartic acid and 45 and 9.3 mmol h-1 mg-1 protein for cysteinesulphinic acid. Both enzymes exhibit maximum activity at pH 8.6. A high specific activity is found in optimal conditions for these two transaminases, the pI values being 9.06 and 5.70 for cysteinesulphinate transaminase A and B respectively. These results have been compared with those already obtained for purified aspartate aminotransferase. Similarities in the pathways of taurine and gamma-aminobutyric acid (GABA) metabolism are discussed.

  10. Synthetic and Biopolymer Gels - Similarities and Difference.

    NASA Astrophysics Data System (ADS)

    Horkay, Ferenc

    2006-03-01

    Ion exchange plays a central role in a variety of physiological processes, such as nerve excitation, muscle contraction and cell locomotion. Hydrogels can be used as model systems for identifying fundamental chemical and physical interactions that govern structure formation, phase transition, etc. in biopolymer systems. Polyelectrolyte gels are particularly well-suited to study ion-polymer interactions because their structure and physical-chemical properties (charge density, crosslink density, etc) can be carefully controlled. They are sensitive to different external stimuli such as temperature, ionic composition and pH. Surprisingly few investigations have been made on polyelectrolyte gels in salt solutions containing both monovalent and multivalent cations. We have developed an experimental approach that combines small angle neutron scattering and osmotic swelling pressure measurements. The osmotic pressure exerted on a macroscopic scale is a consequence of changes occurring at a molecular level. The intensity of the neutron scattering signal, which provides structural information as a function of spatial resolution, is directly related to the osmotic pressure. We have found a striking similarity in the scattering and osmotic behavior of polyacrylic acid gels and DNA gels swollen in nearly physiological salt solutions. Addition of calcium ions to both systems causes a sudden volume change. This volume transition, which occurs when the majority of the sodium counterions are replaced by calcium ions, is reversible. Such reversibility implies that the calcium ions are not strongly bound by the polyanion, but are free to move along the polymer chain, which allows these ions to form temporary bridges between negative charges on adjacent chains. Mechanical measurements reveal that the elastic modulus is practically unchanged in the calcium-containing gels, i.e., ion bridging is qualitatively different from covalent crosslinks.

  11. Origin of the Nubian and similar sandstones

    USGS Publications Warehouse

    McKee, E.D.

    1963-01-01

    The Nubian Sandstone and similar sandstone bodies exposed across much of northern Africa and adjoining parts of Asia are characteristically formed of clean sand that is conspicuously cross stratified throughout. Such sandstone, here called Nubian-type sandstone, ranges from Cambrian through Cretaceous in age and its genesis has been interpreted in many ways. Studies of its primary structures, and of the direction of sand transport, based on statistical measurements of foreset dip directions, have contributed new data on its genesis. By far the most common structure in Nubian-type sandstone is a medium-scale planar-type cross stratification in which sets of evenly dipping cross beds are bounded by essentially flat-lying top and bottom surfaces to form tabular bodies. Other less numerous but typical structures are large-scale, truncated-wedge cross strata, trough-type cross strata, intraformational recumbent folds, small-scale ripple laminae, and dipping sets of tabular-planar cross beds. An analysis of these structures suggests that in the typical Nubian Sandstone of Cretaceous age eolian deposits are not represented and normal marine types probably also are lacking; flood plain, pond or lagoon, and other continental and marginal environments are indicated. In the Carboniferous rocks of Sinai Peninsula some beach sandstone and possibly some eolian, in addition to the types described, form part of the sequence. Direction of sand transport, as determined from cross-bed dips, was northerly in the Cretaceous Nubian of Libya, Sudan, and Egypt; easterly in the Jurassic Adigrat of Ethiopia; westerly in the Carboniferous of Sinai; northwesterly in the early Paleozoic of Jordan. ?? 1963 Ferdinand Enke Verlag Stuttgart.

  12. Pattern Formation

    NASA Astrophysics Data System (ADS)

    Hoyle, Rebecca

    2006-03-01

    From the stripes of a zebra and the spots on a leopard's back to the ripples on a sandy beach or desert dune, regular patterns arise everywhere in nature. The appearance and evolution of these phenomena has been a focus of recent research activity across several disciplines. This book provides an introduction to the range of mathematical theory and methods used to analyse and explain these often intricate and beautiful patterns. Bringing together several different approaches, from group theoretic methods to envelope equations and theory of patterns in large-aspect ratio-systems, the book also provides insight behind the selection of one pattern over another. Suitable as an upper-undergraduate textbook for mathematics students or as a fascinating, engaging, and fully illustrated resource for readers in physics and biology, Rebecca Hoyle's book, using a non-partisan approach, unifies a range of techniques used by active researchers in this growing field. Accessible description of the mathematical theory behind fascinating pattern formation in areas such as biology, physics and materials science Collects recent research for the first time in an upper level textbook Features a number of exercises - with solutions online - and worked examples

  13. Phenylethynyl Containing Reactive Additives

    NASA Technical Reports Server (NTRS)

    Connell, John W. (Inventor); Smith, Joseph G., Jr. (Inventor); Hergenrother, Paul M. (Inventor)

    2002-01-01

    Phenylethynyl containing reactive additives were prepared from aromatic diamine, containing phenylethvnvl groups and various ratios of phthalic anhydride and 4-phenylethynviphthalic anhydride in glacial acetic acid to form the imide in one step or in N-methyl-2-pvrrolidinone to form the amide acid intermediate. The reactive additives were mixed in various amounts (10% to 90%) with oligomers containing either terminal or pendent phenylethynyl groups (or both) to reduce the melt viscosity and thereby enhance processability. Upon thermal cure, the additives react and become chemically incorporated into the matrix and effect an increase in crosslink density relative to that of the host resin. This resultant increase in crosslink density has advantageous consequences on the cured resin properties such as higher glass transition temperature and higher modulus as compared to that of the host resin.

  14. Fused Lasso Additive Model

    PubMed Central

    Petersen, Ashley; Witten, Daniela; Simon, Noah

    2016-01-01

    We consider the problem of predicting an outcome variable using p covariates that are measured on n independent observations, in a setting in which additive, flexible, and interpretable fits are desired. We propose the fused lasso additive model (FLAM), in which each additive function is estimated to be piecewise constant with a small number of adaptively-chosen knots. FLAM is the solution to a convex optimization problem, for which a simple algorithm with guaranteed convergence to a global optimum is provided. FLAM is shown to be consistent in high dimensions, and an unbiased estimator of its degrees of freedom is proposed. We evaluate the performance of FLAM in a simulation study and on two data sets. Supplemental materials are available online, and the R package flam is available on CRAN. PMID:28239246

  15. Phenylethynyl Containing Reactive Additives

    NASA Technical Reports Server (NTRS)

    Connell, John W. (Inventor); Smith, Joseph G., Jr. (Inventor); Hergenrother, Paul M. (Inventor)

    2002-01-01

    Phenylethynyl containing reactive additives were prepared from aromatic diamines containing phenylethynyl groups and various ratios of phthalic anhydride and 4-phenylethynylphthalic anhydride in glacial acetic acid to form the imide in one step or in N-methyl-2-pyrrolidi none to form the amide acid intermediate. The reactive additives were mixed in various amounts (10% to 90%) with oligomers containing either terminal or pendent phenylethynyl groups (or both) to reduce the melt viscosity and thereby enhance processability. Upon thermal cure, the additives react and become chemically incorporated into the matrix and effect an increase in crosslink density relative to that of the host resin. This resultant increase in crosslink density has advantageous consequences on the cured resin properties such as higher glass transition temperature and higher modulus as compared to that of the host resin.

  16. Data declustering for efficient range and similarity searching

    NASA Astrophysics Data System (ADS)

    Prabhakar, Sunil; Agrawal, Divyakant; El Abbadi, Amr

    1998-10-01

    Advances in processor and network technologies have catalyzed the growth of data intensive applications such as image repositories and digital libraries. The lack of commensurate improvements in storage systems have resulted in I/O becoming a major bottleneck in modern systems. The use of parallel I/O from multiple devices is a well known technique for improving I/O performance. A key factor in exploiting parallel I/O is knowledge of the access pattern-- the sets of data items that are likely to be accessed concurrently should be declustered across the disks. Range and nearest-neighbor (similarity) queries are the most important class of queries for multimedia databases. Declustering schemes tailored for improving the performance of range only or similarity only queries have been proposed in the literature. The problem of declustering for combined range and similarity queries has not been addressed in the literature.

  17. Additives in plastics.

    PubMed Central

    Deanin, R D

    1975-01-01

    The polymers used in plastics are generally harmless. However, they are rarely used in pure form. In almost all commercial plastics, they are "compounded" with monomeric ingredients to improve their processing and end-use performance. In order of total volume used, these monomeric additives may be classified as follows: reinforcing fibers, fillers, and coupling agents; plasticizers; colorants; stabilizers (halogen stabilizers, antioxidants, ultraviolet absorbers, and biological preservatives); processing aids (lubricants, others, and flow controls); flame retardants, peroxides; and antistats. Some information is already available, and much more is needed, on potential toxicity and safe handling of these additives during processing and manufacture of plastics products. PMID:1175566

  18. Additives in plastics.

    PubMed

    Deanin, R D

    1975-06-01

    The polymers used in plastics are generally harmless. However, they are rarely used in pure form. In almost all commercial plastics, they are "compounded" with monomeric ingredients to improve their processing and end-use performance. In order of total volume used, these monomeric additives may be classified as follows: reinforcing fibers, fillers, and coupling agents; plasticizers; colorants; stabilizers (halogen stabilizers, antioxidants, ultraviolet absorbers, and biological preservatives); processing aids (lubricants, others, and flow controls); flame retardants, peroxides; and antistats. Some information is already available, and much more is needed, on potential toxicity and safe handling of these additives during processing and manufacture of plastics products.

  19. Similarity-Dissimilarity Competition in Disjunctive Classification Tasks

    PubMed Central

    Mathy, Fabien; Haladjian, Harry H.; Laurent, Eric; Goldstone, Robert L.

    2013-01-01

    Typical disjunctive artificial classification tasks require participants to sort stimuli according to rules such as “x likes cars only when black and coupe OR white and SUV.” For categories like this, increasing the salience of the diagnostic dimensions has two simultaneous effects: increasing the distance between members of the same category and increasing the distance between members of opposite categories. Potentially, these two effects respectively hinder and facilitate classification learning, leading to competing predictions for learning. Increasing saliency may lead to members of the same category to be considered less similar, while the members of separate categories might be considered more dissimilar. This implies a similarity-dissimilarity competition between two basic classification processes. When focusing on sub-category similarity, one would expect more difficult classification when members of the same category become less similar (disregarding the increase of between-category dissimilarity); however, the between-category dissimilarity increase predicts a less difficult classification. Our categorization study suggests that participants rely more on using dissimilarities between opposite categories than finding similarities between sub-categories. We connect our results to rule- and exemplar-based classification models. The pattern of influences of within- and between-category similarities are challenging for simple single-process categorization systems based on rules or exemplars. Instead, our results suggest that either these processes should be integrated in a hybrid model, or that category learning operates by forming clusters within each category. PMID:23403979

  20. Angular-Similarity-Preserving Binary Signatures for Linear Subspaces.

    PubMed

    Ji, Jianqiu; Li, Jianmin; Tian, Qi; Yan, Shuicheng; Zhang, Bo

    2015-11-01

    We propose a similarity-preserving binary signature method for linear subspaces. In computer vision and pattern recognition, linear subspace is a very important representation for many kinds of data, such as face images, action and gesture videos, and so on. When there is a large amount of subspace data and the ambient dimension is high, the cost of computing the pairwise similarity between the subspaces would be high and it requires a large storage space for storing the subspaces. In this paper, we first define the angular similarity and angular distance between the subspaces. Then, based on this similarity definition, we develop a similarity-preserving binary signature method for linear subspaces, which transforms a linear subspace into a compact binary signature, and the Hamming distance between two signatures provides an unbiased estimate of the angular similarity between the two subspaces. We also provide a lower bound of the signature length sufficient to guarantee uniform distance-preservation between every pair of subspaces in a set. Experiments on face recognition, gesture recognition, and action recognition verify the effectiveness of the proposed method.

  1. Online multiple kernel similarity learning for visual search.

    PubMed

    Xia, Hao; Hoi, Steven C H; Jin, Rong; Zhao, Peilin

    2014-03-01

    Recent years have witnessed a number of studies on distance metric learning to improve visual similarity search in content-based image retrieval (CBIR). Despite their successes, most existing methods on distance metric learning are limited in two aspects. First, they usually assume the target proximity function follows the family of Mahalanobis distances, which limits their capacity of measuring similarity of complex patterns in real applications. Second, they often cannot effectively handle the similarity measure of multimodal data that may originate from multiple resources. To overcome these limitations, this paper investigates an online kernel similarity learning framework for learning kernel-based proximity functions which goes beyond the conventional linear distance metric learning approaches. Based on the framework, we propose a novel online multiple kernel similarity (OMKS) learning method which learns a flexible nonlinear proximity function with multiple kernels to improve visual similarity search in CBIR. We evaluate the proposed technique for CBIR on a variety of image data sets in which encouraging results show that OMKS outperforms the state-of-the-art techniques significantly.

  2. Phenotypic similarity in sympatric crow species: Evidence of social convergence?

    PubMed

    Laiolo, Paola

    2017-04-01

    Crows, rooks, and ravens (Corvus spp.) display marked morphological and voice similarities that have been hypothesized to stem from competitive interactions, as a case of nonaposematic mimicry. Here, I test predictions of the mimicry hypothesis at the macrovolutionary scale, examining whether species morphological and acoustic traits covary with those of coexisting congeners, and whether phenotypic similarity has facilitated the coexistence of related species after secondary contact. Body size and the temporal patterns of the commonest call display high levels of similarity among sympatric species, even after controlling for the effect of shared climate and habitat, and phylogenetic constraints in the production of variation. When sister species differed in these acoustic and morphological traits, their transition to secondary sympatry was delayed relative to those with more similar traits. No similarity was found in the sexual call of crows, suggesting that convergence occurs only when function does not favour maintenance of species-specific traits. Crow similarities in morphological and acoustic features may therefore be associated with coevolving interactions with congeners, in line with a broad array of studies documenting convergence among species that interact aggressively or forage communally.

  3. Block Copolymer Thin Films: Patterns and Patterning

    NASA Astrophysics Data System (ADS)

    Register, Richard A.

    2001-03-01

    The nanostructures ("microdomains") in thin block copolymer films make excellent contact masks for surface patterning on the nanoscale. Using these thin films as templates, we have developed techniques based on reactive ion etching to uniformly and completely pattern the underlying substrate with a dense periodic pattern of dots, holes, or lines, with widths of order 20 nm. In addition, we have fabricated arrays of metal dots by backfilling these holes, and GaAs quantum dots by regrowth onto patterned GaAs substrates. A key issue in this nanopatterning approach is controlling the pattern which forms within the mask. While the local structure of the pattern (e.g., spheres vs. cylinders) is easily controlled through block copolymer composition, the long-range order ("grain size") is more difficult to manipulate. For cylinder-forming diblocks, we find that the correlation length of the microdomains grows as a weak power of annealing time, approximately 1/4. The principal types of defects which destroy the long-range order of the microdomains are disclinations. Sequential AFM images taken on the same region of the film after varying annealing times can be strung together into "movies" (to be shown at the talk) which directly show that the principal mode of defect annihilation (and hence grain growth) is the annihilation of disclination quadrupoles (pairs of +1/2 and -1/2 disclinations). We propose a model for quadrupole annihilation which reproduces the 1/4 exponent. Preliminary results for sphere-forming systems suggest that the exponent there is even lower than 1/4, making it difficult to achieve a significant degree of coarsening by extending the annealing time. * in collaboration with D.H. Adamson, P.M. Chaikin, Z. Cheng, P.D. Dapkus (USC), C.K. Harrison, D.A. Huse, R.R. Li (USC), and M. Park.

  4. 3-D laser patterning process utilizing horizontal and vertical patterning

    DOEpatents

    Malba, Vincent; Bernhardt, Anthony F.

    2000-01-01

    A process which vastly improves the 3-D patterning capability of laser pantography (computer controlled laser direct-write patterning). The process uses commercially available electrodeposited photoresist (EDPR) to pattern 3-D surfaces. The EDPR covers the surface of a metal layer conformally, coating the vertical as well as horizontal surfaces. A laser pantograph then patterns the EDPR, which is subsequently developed in a standard, commercially available developer, leaving patterned trench areas in the EDPR. The metal layer thereunder is now exposed in the trench areas and masked in others, and thereafter can be etched to form the desired pattern (subtractive process), or can be plated with metal (additive process), followed by a resist stripping, and removal of the remaining field metal (additive process). This improved laser pantograph process is simpler, faster, move manufacturable, and requires no micro-machining.

  5. Notions of similarity for systems biology models.

    PubMed

    Henkel, Ron; Hoehndorf, Robert; Kacprowski, Tim; Knüpfer, Christian; Liebermeister, Wolfram; Waltemath, Dagmar

    2016-10-14

    Systems biology models are rapidly increasing in complexity, size and numbers. When building large models, researchers rely on software tools for the retrieval, comparison, combination and merging of models, as well as for version control. These tools need to be able to quantify the differences and similarities between computational models. However, depending on the specific application, the notion of 'similarity' may greatly vary. A general notion of model similarity, applicable to various types of models, is still missing. Here we survey existing methods for the comparison of models, introduce quantitative measures for model similarity, and discuss potential applications of combined similarity measures. To frame model comparison as a general problem, we describe a theoretical approach to defining and computing similarities based on a combination of different model aspects. The six aspects that we define as potentially relevant for similarity are underlying encoding, references to biological entities, quantitative behaviour, qualitative behaviour, mathematical equations and parameters and network structure. We argue that future similarity measures will benefit from combining these model aspects in flexible, problem-specific ways to mimic users' intuition about model similarity, and to support complex model searches in databases.

  6. Similarity effects in visual working memory.

    PubMed

    Jiang, Yuhong V; Lee, Hyejin J; Asaad, Anthony; Remington, Roger

    2016-04-01

    Perceptual similarity is an important property of multiple stimuli. Its computation supports a wide range of cognitive functions, including reasoning, categorization, and memory recognition. It is important, therefore, to determine why previous research has found conflicting effects of inter-item similarity on visual working memory. Studies reporting a similarity advantage have used simple stimuli whose similarity varied along a featural continuum. Studies reporting a similarity disadvantage have used complex stimuli from either a single or multiple categories. To elucidate stimulus conditions for similarity effects in visual working memory, we tested memory for complex stimuli (faces) whose similarity varied along a morph continuum. Participants encoded 3 morphs generated from a single face identity in the similar condition, or 3 morphs generated from different face identities in the dissimilar condition. After a brief delay, a test face appeared at one of the encoding locations for participants to make a same/different judgment. Two experiments showed that similarity enhanced memory accuracy without changing the response criterion. These findings support previous computational models that incorporate featural variance as a component of working memory load. They delineate limitations of models that emphasize cortical resources or response decisions.

  7. Biobased lubricant additives

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Fully biobased lubricants are those formulated using all biobased ingredients, i.e. biobased base oils and biobased additives. Such formulations provide the maximum environmental, safety, and economic benefits expected from a biobased product. Currently, there are a number of biobased base oils that...

  8. More Than Additional Space...

    ERIC Educational Resources Information Center

    CEFP Journal, 1973

    1973-01-01

    A much needed addition to the Jamestown Elementary School turned out to be more than an expansion of walls for more space. A new educational program, a limited budget, and a short time line were tackled on a team approach basis and were successfully resolved. (Author)

  9. Overspecification of color, pattern, and size: salience, absoluteness, and consistency

    PubMed Central

    Tarenskeen, Sammie; Broersma, Mirjam; Geurts, Bart

    2015-01-01

    The rates of overspecification of color, pattern, and size are compared, to investigate how salience and absoluteness contribute to the production of overspecification. Color and pattern are absolute and salient attributes, whereas size is relative and less salient. Additionally, a tendency toward consistent responses is assessed. Using a within-participants design, we find similar rates of color and pattern overspecification, which are both higher than the rate of size overspecification. Using a between-participants design, however, we find similar rates of pattern and size overspecification, which are both lower than the rate of color overspecification. This indicates that although many speakers are more likely to include color than pattern (probably because color is more salient), they may also treat pattern like color due to a tendency toward consistency. We find no increase in size overspecification when the salience of size is increased, suggesting that speakers are more likely to include absolute than relative attributes. However, we do find an increase in size overspecification when mentioning the attributes is triggered, which again shows that speakers tend to refer in a consistent manner, and that there are circumstances in which even size overspecification is frequently produced. PMID:26594190

  10. Learning of a simple grapho-motor task by young children and adults: similar acquisition but age-dependent retention

    PubMed Central

    Julius, Mona S.; Adi-Japha, Esther

    2015-01-01

    Many new skills are acquired during early childhood. Typical laboratory skill learning tasks are not applicable for developmental studies that involve children younger than 8 years of age. It is not clear whether young children and adults share a basic underlying skill learning mechanism. In the present study, the learning and retention of a simple grapho-motor pattern were studied in three age groups: 5–6, 7–8, and 19–29 years. Each block of the task consists of identical patterns arranged in a spaced writing array. Progression across the block involves on-page movements while producing the pattern, and off-page movements between patterns. The participants practiced the production of the pattern using a digitizing tablet and were tested at 24 h and 2 weeks post-practice. All age groups produced the task blocks more quickly with practice, and the learning rate was inversely related to the initial production time. All groups exhibited additional gains 24 h post-practice that were well-retained 2 weeks later. The accuracy of the participants was maintained throughout the 2-weeks period. These findings suggest that young children and young adults use a similar mechanism when learning the task. Nevertheless, the 6-years-old spent more time off-page during retention testing than when tested at 24 h post-practice, thus supporting the notion that an age advantage may exists in the long-term retention of skills due to planning-dependent aspects. PMID:25798120

  11. Documents Similarity Measurement Using Field Association Terms.

    ERIC Educational Resources Information Center

    Atlam, El-Sayed; Fuketa, M.; Morita, K.; Aoe, Jun-ichi

    2003-01-01

    Discussion of text analysis and information retrieval and measurement of document similarity focuses on a new text manipulation system called FA (field association)-Sim that is useful for retrieving information in large heterogeneous texts and for recognizing content similarity in text excerpts. Discusses recall and precision, automatic indexing…

  12. Guaranteed classification via regularized similarity learning.

    PubMed

    Guo, Zheng-Chu; Ying, Yiming

    2014-03-01

    Learning an appropriate (dis)similarity function from the available data is a central problem in machine learning, since the success of many machine learning algorithms critically depends on the choice of a similarity function to compare examples. Despite many approaches to similarity metric learning that have been proposed, there has been little theoretical study on the links between similarity metric learning and the classification performance of the resulting classifier. In this letter, we propose a regularized similarity learning formulation associated with general matrix norms and establish their generalization bounds. We show that the generalization error of the resulting linear classifier can be bounded by the derived generalization bound of similarity learning. This shows that a good generalization of the learned similarity function guarantees a good classification of the resulting linear classifier. Our results extend and improve those obtained by Bellet, Habrard, and Sebban (2012). Due to the techniques dependent on the notion of uniform stability (Bousquet & Elisseeff, 2002), the bound obtained there holds true only for the Frobenius matrix-norm regularization. Our techniques using the Rademacher complexity (Bartlett & Mendelson, 2002) and its related Khinchin-type inequality enable us to establish bounds for regularized similarity learning formulations associated with general matrix norms, including sparse L1-norm and mixed (2,1)-norm.

  13. Feature matching algorithm based on spatial similarity

    NASA Astrophysics Data System (ADS)

    Tang, Wenjing; Hao, Yanling; Zhao, Yuxin; Li, Ning

    2008-10-01

    The disparities of features that represent the same real world entities from disparate sources usually occur, thus the identification or matching of features is crutial to the map conflation. Motivated by the idea of identifying the same entities through integrating known information by eyes, the feature matching algorithm based on spatial similarity is proposed in this paper. Total similarity is obtained by integrating positional similarity, shape similarity and size similarity with a weighted average algorithm, then the matching entities is achieved according to the maximum total similarity. The matching of areal features is analyzed in detail. Regarding the areal feature as a whole, the proposed algorithm identifies the same areal features by their shape-center points in order to calculate their positional similarity, and shape similarity is given by the function of describing the shape, which ensures its precision not be affected by interferes and avoids the loss of shape information, furthermore the size of areal features is measured by their covered areas. Test results show the stability and reliability of the proposed algorithm, and its precision and recall are higher than other matching algorithm.

  14. Structure Mapping in Analogy and Similarity.

    ERIC Educational Resources Information Center

    Gentner, Dedre; Markman, Arthur B.

    1997-01-01

    It is suggested that both similarity and analogy involve a process of structural alignment and mapping. The structure mapping process is described as it has been worked out for analogy, and this view is then extended to similarity and used to generate new predictions. (SLD)

  15. Perceived Similarity, Proactive Adjustment, and Organizational Socialization

    ERIC Educational Resources Information Center

    Kammeyer-Mueller, John D.; Livingston, Beth A.; Liao, Hui

    2011-01-01

    The present study explores how perceived demographic and attitudinal similarity can influence proactive behavior among organizational newcomers. We propose that newcomers who perceive themselves as similar to their co-workers will be more willing to seek new information or build relationships, which in turn will lead to better long-term…

  16. Marking Student Programs Using Graph Similarity

    ERIC Educational Resources Information Center

    Naude, Kevin A.; Greyling, Jean H.; Vogts, Dieter

    2010-01-01

    We present a novel approach to the automated marking of student programming assignments. Our technique quantifies the structural similarity between unmarked student submissions and marked solutions, and is the basis by which we assign marks. This is accomplished through an efficient novel graph similarity measure ("AssignSim"). Our experiments…

  17. Mining Diagnostic Assessment Data for Concept Similarity

    ERIC Educational Resources Information Center

    Madhyastha, Tara; Hunt, Earl

    2009-01-01

    This paper introduces a method for mining multiple-choice assessment data for similarity of the concepts represented by the multiple choice responses. The resulting similarity matrix can be used to visualize the distance between concepts in a lower-dimensional space. This gives an instructor a visualization of the relative difficulty of concepts…

  18. Vinyl capped addition polyimides

    NASA Technical Reports Server (NTRS)

    Vannucci, Raymond D. (Inventor); Malarik, Diane C. (Inventor); Delvigs, Peter (Inventor)

    1991-01-01

    Polyimide resins (PMR) are generally useful where high strength and temperature capabilities are required (at temperatures up to about 700 F). Polyimide resins are particularly useful in applications such as jet engine compressor components, for example, blades, vanes, air seals, air splitters, and engine casing parts. Aromatic vinyl capped addition polyimides are obtained by reacting a diamine, an ester of tetracarboxylic acid, and an aromatic vinyl compound. Low void materials with improved oxidative stability when exposed to 700 F air may be fabricated as fiber reinforced high molecular weight capped polyimide composites. The aromatic vinyl capped polyimides are provided with a more aromatic nature and are more thermally stable than highly aliphatic, norbornenyl-type end-capped polyimides employed in PMR resins. The substitution of aromatic vinyl end-caps for norbornenyl end-caps in addition polyimides results in polymers with improved oxidative stability.

  19. Electrophilic addition of astatine

    SciTech Connect

    Norseev, Yu.V.; Vasaros, L.; Nhan, D.D.; Huan, N.K.

    1988-03-01

    It has been shown for the first time that astatine is capable of undergoing addition reactions to unsaturated hydrocarbons. A new compound of astatine, viz., ethylene astatohydrin, has been obtained, and its retention numbers of squalane, Apiezon, and tricresyl phosphate have been found. The influence of various factors on the formation of ethylene astatohydrin has been studied. It has been concluded on the basis of the results obtained that the univalent cations of astatine in an acidic medium is protonated hypoastatous acid.

  20. Criteria for dynamic similarity in bouncing gaits.

    PubMed

    Bullimore, Sharon R; Donelan, J Maxwell

    2008-01-21

    Animals of different sizes tend to move in a dynamically similar manner when travelling at speeds corresponding to equal values of a dimensionless parameter (DP) called the Froude number. Consequently, the Froude number has been widely used for defining equivalent speeds and predicting speeds of locomotion by extinct species and on other planets. However, experiments using simulated reduced gravity have demonstrated that equality of the Froude number does not guarantee dynamic similarity. This has cast doubt upon the usefulness of the Froude number in locomotion research. Here we use dimensional analysis of the planar spring-mass model, combined with Buckingham's Pi-Theorem, to demonstrate that four DPs must be equal for dynamic similarity in bouncing gaits such as trotting, hopping and bipedal running. This can be reduced to three DPs by applying the constraint of maintaining a constant average speed of locomotion. Sensitivity analysis indicates that all of these DPs are important for predicting dynamic similarity. We show that the reason humans do not run in a dynamically similar manner at equal Froude number in different levels of simulated reduced gravity is that dimensionless leg stiffness decreases as gravity increases. The reason that the Froude number can predict dynamic similarity in Earth gravity is that dimensionless leg stiffness and dimensionless vertical landing speed are both independent of size. In conclusion, although equal Froude number is not sufficient for dynamic similarity, it is a necessary condition. Therefore, to detect fundamental differences in locomotion, animals of different sizes should be compared at equal Froude number, so that they can be as close to dynamic similarity as possible. More generally, the concept of dynamic similarity provides a powerful framework within which similarities and differences in locomotion can be interpreted.

  1. Contrasting HIV phylogenetic relationships and V3 loop protein similarities

    SciTech Connect

    Korber, B. Santa Fe Inst., NM ); Myers, G. )

    1992-01-01

    At least five distinct sequence subtypes of HIV-I can be identified from the major centers of the AMS pandemic. While it is too early to tell whether these subtypes are serologically or phenotypically similar or distinct in terms of properties such as pathogenicity and transmissibility, we can begin to investigate their potential for phenotypic divergence at the protein sequence level. Phylogenetic analysis of HIV DNA sequences is being widely used to examine lineages of different viral strains as they evolve and spread throughout the globe. We have identified five distinct HIV-1 subtypes (designated A-E), or clades, based on phylogenetic clustering patterns generated from genetic information from both the gag and envelope (env) genes from a spectrum of international isolates. Our initial observations concerning both HIV-1 and HIV-2 sequences indicate that conserved patterns in protein chemistry may indeed exist across distant lineages. Such patterns in V3 loop amino acid chemistry may be indicative of stable lineages or convergence within this highly variable, though functionally and immunologically critical, region. We think that there may be parallels between the apparently stable HIV-2 V3 lineage and the previously mentioned HIV-1 V3 loops which are very similar at the protein level despite being distant by cladistic analysis, and which do not possess the distinctive positively charged residues. Highly conserved V3 loop protein sequences are also encountered in SIVAGMs and CIVs (chimpanzee viral strains), which do not appear to be pathogenic in their wild-caught natural hosts.

  2. Contrasting HIV phylogenetic relationships and V3 loop protein similarities

    SciTech Connect

    Korber, B. |; Myers, G.

    1992-12-31

    At least five distinct sequence subtypes of HIV-I can be identified from the major centers of the AMS pandemic. While it is too early to tell whether these subtypes are serologically or phenotypically similar or distinct in terms of properties such as pathogenicity and transmissibility, we can begin to investigate their potential for phenotypic divergence at the protein sequence level. Phylogenetic analysis of HIV DNA sequences is being widely used to examine lineages of different viral strains as they evolve and spread throughout the globe. We have identified five distinct HIV-1 subtypes (designated A-E), or clades, based on phylogenetic clustering patterns generated from genetic information from both the gag and envelope (env) genes from a spectrum of international isolates. Our initial observations concerning both HIV-1 and HIV-2 sequences indicate that conserved patterns in protein chemistry may indeed exist across distant lineages. Such patterns in V3 loop amino acid chemistry may be indicative of stable lineages or convergence within this highly variable, though functionally and immunologically critical, region. We think that there may be parallels between the apparently stable HIV-2 V3 lineage and the previously mentioned HIV-1 V3 loops which are very similar at the protein level despite being distant by cladistic analysis, and which do not possess the distinctive positively charged residues. Highly conserved V3 loop protein sequences are also encountered in SIVAGMs and CIVs (chimpanzee viral strains), which do not appear to be pathogenic in their wild-caught natural hosts.

  3. Functional Generalized Additive Models.

    PubMed

    McLean, Mathew W; Hooker, Giles; Staicu, Ana-Maria; Scheipl, Fabian; Ruppert, David

    2014-01-01

    We introduce the functional generalized additive model (FGAM), a novel regression model for association studies between a scalar response and a functional predictor. We model the link-transformed mean response as the integral with respect to t of F{X(t), t} where F(·,·) is an unknown regression function and X(t) is a functional covariate. Rather than having an additive model in a finite number of principal components as in Müller and Yao (2008), our model incorporates the functional predictor directly and thus our model can be viewed as the natural functional extension of generalized additive models. We estimate F(·,·) using tensor-product B-splines with roughness penalties. A pointwise quantile transformation of the functional predictor is also considered to ensure each tensor-product B-spline has observed data on its support. The methods are evaluated using simulated data and their predictive performance is compared with other competing scalar-on-function regression alternatives. We illustrate the usefulness of our approach through an application to brain tractography, where X(t) is a signal from diffusion tensor imaging at position, t, along a tract in the brain. In one example, the response is disease-status (case or control) and in a second example, it is the score on a cognitive test. R code for performing the simulations and fitting the FGAM can be found in supplemental materials available online.

  4. Similar Processes Despite Divergent Behavior in Two Commonly Used Measures of Risky Decision Making

    PubMed Central

    BISHARA, ANTHONY J.; PLESKAC, TIMOTHY J.; FRIDBERG, DANIEL J.; YECHIAM, ELDAD; LUCAS, JESOLYN; BUSEMEYER, JEROME R.; FINN, PETER R.; STOUT, JULIE C.

    2011-01-01

    Performance on complex decision-making tasks may depend on a multitude of processes. Two such tasks, the Iowa Gambling Task (IGT) and Balloon Analog Risk Task (BART), are of particular interest because they are associated with real world risky behavior, including illegal drug use. We used cognitive models to disentangle underlying processes in both tasks. Whereas behavioral measures from the IGT and BART were uncorrelated, cognitive models revealed two reliable cross-task associations. Results suggest that the tasks similarly measure loss aversion and decision-consistency processes, but not necessarily the same learning process. Additionally, substance-using individuals (and especially stimulant users) performed worse on the IGT than healthy controls did, and this pattern could be explained by reduced decision consistency. PMID:21836771

  5. Transformed Neural Pattern Reinstatement during Episodic Memory Retrieval.

    PubMed

    Xiao, Xiaoqian; Dong, Qi; Gao, Jiahong; Men, Weiwei; Poldrack, Russell A; Xue, Gui

    2017-03-15

    Contemporary models of episodic memory posit that remembering involves the reenactment of encoding processes. Although encoding-retrieval similarity has been consistently reported and linked to memory success, the nature of neural pattern reinstatement is poorly understood. Using high-resolution fMRI on human subjects, our results obtained clear evidence for item-specific pattern reinstatement in the frontoparietal cortex, even when the encoding-retrieval pairs shared no perceptual similarity. No item-specific pattern reinstatement was found in the ventral visual cortex. Importantly, the brain regions and voxels carrying item-specific representation differed significantly between encoding and retrieval, and the item specificity for encoding-retrieval similarity was smaller than that for encoding or retrieval, suggesting different nature of representations between encoding and retrieval. Moreover, cross-region representational similarity analysis suggests that the encoded representation in the ventral visual cortex was reinstated in the frontoparietal cortex during retrieval. Together, these results suggest that, in addition to reinstatement of the originally encoded pattern in the brain regions that perform encoding processes, retrieval may also involve the reinstatement of a transformed representation of the encoded information. These results emphasize the constructive nature of memory retrieval that helps to serve important adaptive functions.SIGNIFICANCE STATEMENT Episodic memory enables humans to vividly reexperience past events, yet how this is achieved at the neural level is barely understood. A long-standing hypothesis posits that memory retrieval involves the faithful reinstatement of encoding-related activity. We tested this hypothesis by comparing the neural representations during encoding and retrieval. We found strong pattern reinstatement in the frontoparietal cortex, but not in the ventral visual cortex, that represents visual details. Critically

  6. Evolution of solidification texture during additive manufacturing

    PubMed Central

    Wei, H. L.; Mazumder, J.; DebRoy, T.

    2015-01-01

    Striking differences in the solidification textures of a nickel based alloy owing to changes in laser scanning pattern during additive manufacturing are examined based on theory and experimental data. Understanding and controlling texture are important because it affects mechanical and chemical properties. Solidification texture depends on the local heat flow directions and competitive grain growth in one of the six <100> preferred growth directions in face centered cubic alloys. Therefore, the heat flow directions are examined for various laser beam scanning patterns based on numerical modeling of heat transfer and fluid flow in three dimensions. Here we show that numerical modeling can not only provide a deeper understanding of the solidification growth patterns during the additive manufacturing, it also serves as a basis for customizing solidification textures which are important for properties and performance of components. PMID:26553246

  7. Evolution of solidification texture during additive manufacturing

    DOE PAGES

    Wei, H. L.; Mazumder, J.; DebRoy, T.

    2015-11-10

    Striking differences in the solidification textures of a nickel based alloy owing to changes in laser scanning pattern during additive manufacturing are examined based on theory and experimental data. Understanding and controlling texture are important because it affects mechanical and chemical properties. Solidification texture depends on the local heat flow directions and competitive grain growth in one of the six <100> preferred growth directions in face centered cubic alloys. Furthermore, the heat flow directions are examined for various laser beam scanning patterns based on numerical modeling of heat transfer and fluid flow in three dimensions. Here we show that numericalmore » modeling can not only provide a deeper understanding of the solidification growth patterns during the additive manufacturing, it also serves as a basis for customizing solidification textures which are important for properties and performance of components.« less

  8. Evolution of solidification texture during additive manufacturing

    SciTech Connect

    Wei, H. L.; Mazumder, J.; DebRoy, T.

    2015-11-10

    Striking differences in the solidification textures of a nickel based alloy owing to changes in laser scanning pattern during additive manufacturing are examined based on theory and experimental data. Understanding and controlling texture are important because it affects mechanical and chemical properties. Solidification texture depends on the local heat flow directions and competitive grain growth in one of the six <100> preferred growth directions in face centered cubic alloys. Furthermore, the heat flow directions are examined for various laser beam scanning patterns based on numerical modeling of heat transfer and fluid flow in three dimensions. Here we show that numerical modeling can not only provide a deeper understanding of the solidification growth patterns during the additive manufacturing, it also serves as a basis for customizing solidification textures which are important for properties and performance of components.

  9. Evolution of solidification texture during additive manufacturing.

    PubMed

    Wei, H L; Mazumder, J; DebRoy, T

    2015-11-10

    Striking differences in the solidification textures of a nickel based alloy owing to changes in laser scanning pattern during additive manufacturing are examined based on theory and experimental data. Understanding and controlling texture are important because it affects mechanical and chemical properties. Solidification texture depends on the local heat flow directions and competitive grain growth in one of the six <100> preferred growth directions in face centered cubic alloys. Therefore, the heat flow directions are examined for various laser beam scanning patterns based on numerical modeling of heat transfer and fluid flow in three dimensions. Here we show that numerical modeling can not only provide a deeper understanding of the solidification growth patterns during the additive manufacturing, it also serves as a basis for customizing solidification textures which are important for properties and performance of components.

  10. Evolution of solidification texture during additive manufacturing

    NASA Astrophysics Data System (ADS)

    Wei, H. L.; Mazumder, J.; Debroy, T.

    2015-11-01

    Striking differences in the solidification textures of a nickel based alloy owing to changes in laser scanning pattern during additive manufacturing are examined based on theory and experimental data. Understanding and controlling texture are important because it affects mechanical and chemical properties. Solidification texture depends on the local heat flow directions and competitive grain growth in one of the six <100> preferred growth directions in face centered cubic alloys. Therefore, the heat flow directions are examined for various laser beam scanning patterns based on numerical modeling of heat transfer and fluid flow in three dimensions. Here we show that numerical modeling can not only provide a deeper understanding of the solidification growth patterns during the additive manufacturing, it also serves as a basis for customizing solidification textures which are important for properties and performance of components.

  11. Additive manufacturing of RF absorbers

    NASA Astrophysics Data System (ADS)

    Mills, Matthew S.

    The ability of additive manufacturing techniques to fabricate integrated electromagnetic absorbers tuned for specific radio frequency bands within structural composites allows for unique combinations of mechanical and electromagnetic properties. These composites and films can be used for RF shielding of sensitive electromagnetic components through in-plane and out-of-plane RF absorption. Structural composites are a common building block of many commercial platforms. These platforms may be placed in situations in which there is a need for embedded RF absorbing properties along with structural properties. Instead of adding radar absorbing treatments to the external surface of existing structures, which adds increased size, weight and cost; it could prove to be advantageous to integrate the microwave absorbing properties directly into the composite during the fabrication process. In this thesis, a method based on additive manufacturing techniques of composites structures with prescribed electromagnetic loss, within the frequency range 1 to 26GHz, is presented. This method utilizes screen printing and nScrypt micro dispensing to pattern a carbon based ink onto low loss substrates. The materials chosen for this study will be presented, and the fabrication technique that these materials went through to create RF absorbing structures will be described. The calibration methods used, the modeling of the RF structures, and the applications in which this technology can be utilized will also be presented.

  12. Cardiomyocyte clusters derived from human embryonic stem cells share similarities with human heart tissue.

    PubMed

    Asp, Julia; Steel, Daniella; Jonsson, Marianne; Améen, Caroline; Dahlenborg, Kerstin; Jeppsson, Anders; Lindahl, Anders; Sartipy, Peter

    2010-10-01

    Cardiotoxicity testing is a key activity in the pharmaceutical industry in order to detect detrimental effects of new drugs. A reliable human in vitro model would both be beneficial in selection of lead compounds and be important for reducing animal experimentation. However, the human heart is a complex organ composed of many distinct types of cardiomyocytes, but cardiomyocyte clusters (CMCs) derived from human embryonic stem cells could be an option for a cellular model. Data on functional properties of CMCs demonstrate similarities to their in vivo analogues in human. However, development of an in vitro model requires a more thorough comparison of CMCs to human heart tissue. Therefore, we directly compared individually isolated CMCs to human fetal, neonatal, adult atrial and ventricular heart tissues. Real-time qPCR analysis of mRNA levels and protein staining of ion channels and cardiac markers showed in general a similar expression pattern in CMCs and human heart. Moreover, a significant decrease in beat frequency was noted after addition of Zatebradine, a blocker to I(f) involved in regulation of spontaneous contraction in CMCs. The results underscore the similarities of CMCs to human cardiac tissue, and further support establishment of novel cardiotoxicity assays based on the CMCs in drug discovery.

  13. Drug Promiscuity in PDB: Protein Binding Site Similarity Is Key

    PubMed Central

    Schroeder, Michael

    2013-01-01

    Drug repositioning applies established drugs to new disease indications with increasing success. A pre-requisite for drug repurposing is drug promiscuity (polypharmacology) – a drug’s ability to bind to several targets. There is a long standing debate on the reasons for drug promiscuity. Based on large compound screens, hydrophobicity and molecular weight have been suggested as key reasons. However, the results are sometimes contradictory and leave space for further analysis. Protein structures offer a structural dimension to explain promiscuity: Can a drug bind multiple targets because the drug is flexible or because the targets are structurally similar or even share similar binding sites? We present a systematic study of drug promiscuity based on structural data of PDB target proteins with a set of 164 promiscuous drugs. We show that there is no correlation between the degree of promiscuity and ligand properties such as hydrophobicity or molecular weight but a weak correlation to conformational flexibility. However, we do find a correlation between promiscuity and structural similarity as well as binding site similarity of protein targets. In particular, 71% of the drugs have at least two targets with similar binding sites. In order to overcome issues in detection of remotely similar binding sites, we employed a score for binding site similarity: LigandRMSD measures the similarity of the aligned ligands and uncovers remote local similarities in proteins. It can be applied to arbitrary structural binding site alignments. Three representative examples, namely the anti-cancer drug methotrexate, the natural product quercetin and the anti-diabetic drug acarbose are discussed in detail. Our findings suggest that global structural and binding site similarity play a more important role to explain the observed drug promiscuity in the PDB than physicochemical drug properties like hydrophobicity or molecular weight. Additionally, we find ligand flexibility to have a

  14. The baryonic self similarity of dark matter

    SciTech Connect

    Alard, C.

    2014-06-20

    The cosmological simulations indicates that dark matter halos have specific self-similar properties. However, the halo similarity is affected by the baryonic feedback. By using momentum-driven winds as a model to represent the baryon feedback, an equilibrium condition is derived which directly implies the emergence of a new type of similarity. The new self-similar solution has constant acceleration at a reference radius for both dark matter and baryons. This model receives strong support from the observations of galaxies. The new self-similar properties imply that the total acceleration at larger distances is scale-free, the transition between the dark matter and baryons dominated regime occurs at a constant acceleration, and the maximum amplitude of the velocity curve at larger distances is proportional to M {sup 1/4}. These results demonstrate that this self-similar model is consistent with the basics of modified Newtonian dynamics (MOND) phenomenology. In agreement with the observations, the coincidence between the self-similar model and MOND breaks at the scale of clusters of galaxies. Some numerical experiments show that the behavior of the density near the origin is closely approximated by a Einasto profile.

  15. Measure of Node Similarity in Multilayer Networks

    PubMed Central

    Mollgaard, Anders; Zettler, Ingo; Dammeyer, Jesper; Jensen, Mogens H.; Lehmann, Sune; Mathiesen, Joachim

    2016-01-01

    The weight of links in a network is often related to the similarity of the nodes. Here, we introduce a simple tunable measure for analysing the similarity of nodes across different link weights. In particular, we use the measure to analyze homophily in a group of 659 freshman students at a large university. Our analysis is based on data obtained using smartphones equipped with custom data collection software, complemented by questionnaire-based data. The network of social contacts is represented as a weighted multilayer network constructed from different channels of telecommunication as well as data on face-to-face contacts. We find that even strongly connected individuals are not more similar with respect to basic personality traits than randomly chosen pairs of individuals. In contrast, several socio-demographics variables have a significant degree of similarity. We further observe that similarity might be present in one layer of the multilayer network and simultaneously be absent in the other layers. For a variable such as gender, our measure reveals a transition from similarity between nodes connected with links of relatively low weight to dis-similarity for the nodes connected by the strongest links. We finally analyze the overlap between layers in the network for different levels of acquaintanceships. PMID:27300084

  16. Patterns and dynamics in transitional shear flows

    NASA Astrophysics Data System (ADS)

    Tuckerman, Laurette

    2009-11-01

    One of the greatest mysteries in fluid dynamics is surely transition to turbulence. The classic shear flows -- channel, plane Couette and pipe flow -- while linearly stable, undergo sudden transition to 3D turbulence. In recent years, transition has been attacked with an arsenal of weapons from dynamical systems theory, such as low-dimensional chaos, unstable periodic orbits, heteroclinic connections, fractal basin boundaries. At the same time, 3D physical mechanisms such as streamwise vorticity and streaks have supplanted the 2D picture of linear instability long promoted by Squire's theorem. A striking recent discovery by experimentalists at CEA-Saclay is that large-aspect-ratio plane Couette flow near transition actually takes the form of a steady pattern of wide turbulent and laminar bands, with a fixed angle and wavelength. We have been able to reproduce these remarkable flows in numerical simulations of the Navier-Stokes equations. Simulations display a rich variety of variants of these patterns, including spatio-temporal intermittency, branching and travelling states, and localized states analogous to spots. Because similar patterns have since also been observed in Taylor-Couette, channel and pipe flow, it appears that they are inevitable intermediate states on the route from turbulent to laminar flow in large aspect-ratio shear flows. In addition to their intrinsic interest, these patterns provide clues to the transition to turbulence.

  17. Similarity relations for anisotropic scattering in absorbing media

    NASA Astrophysics Data System (ADS)

    Graaff, Reindert; Aarnoudse, Jan G.; de Mul, Frits F.; Jentink, Henk W.

    1993-02-01

    The validity of the similarity parameter (Sigma) 's equalsV (Sigma) s (1 - g), the reduced scattering coefficient, where g is the average cosine of the scattering phase function is investigated. Attenuation coefficients (alpha) and diffusion patterns are obtained from solutions of the transport equation for isotropic scattering and Rayleigh-Gans scattering, applied to infinite media. Similarity is studied for the attenuation coefficient (alpha) , as well as for the Kubelka-Munk absorption and backscattering coefficients in the positive and negative directions, and for predictions of the internal reflection at interfaces. Similarity between solutions of the Boltzmann equation for highly forward scattering and isotropic scattering (g equals 0) exist only when (Sigma) a << (Sigma) s (1 - g). However, because similarity between results, both with g > 0.9, is independent of the value of the absorption coefficient, it is advantageous to simulate highly forward scattering media like biological tissues with g > 0.9, e.g., by Monte Carlo simulations, instead of using isotropic scattering or diffusion theory. Monte Carlo simulations on slabs confirm the deviations from the diffusion approximation and show the behavior near boundaries. Application of similarity may save calculation time in Monte Carlo simulations, because simulation with a lower value for g will increase the mean free path.

  18. How similar are recognition memory and inductive reasoning?

    PubMed

    Hayes, Brett K; Heit, Evan

    2013-07-01

    Conventionally, memory and reasoning are seen as different types of cognitive activities driven by different processes. In two experiments, we challenged this view by examining the relationship between recognition memory and inductive reasoning involving multiple forms of similarity. A common study set (members of a conjunctive category) was followed by a test set containing old and new category members, as well as items that matched the study set on only one dimension. The study and test sets were presented under recognition or induction instructions. In Experiments 1 and 2, the inductive property being generalized was varied in order to direct attention to different dimensions of similarity. When there was no time pressure on decisions, patterns of positive responding were strongly affected by property type, indicating that different types of similarity were driving recognition and induction. By comparison, speeded judgments showed weaker property effects and could be explained by generalization based on overall similarity. An exemplar model, GEN-EX (GENeralization from EXamples), could account for both the induction and recognition data. These findings show that induction and recognition share core component processes, even when the tasks involve flexible forms of similarity.

  19. Similarity-dissimilarity competition in disjunctive classification tasks.

    PubMed

    Mathy, Fabien; Haladjian, Harry H; Laurent, Eric; Goldstone, Robert L

    2013-01-01

    Typical disjunctive artificial classification tasks require participants to sort stimuli according to rules such as "x likes cars only when black and coupe OR white and SUV." For categories like this, increasing the salience of the diagnostic dimensions has two simultaneous effects: increasing the distance between members of the same category and increasing the distance between members of opposite categories. Potentially, these two effects respectively hinder and facilitate classification learning, leading to competing predictions for learning. Increasing saliency may lead to members of the same category to be considered lesssimilar, while the members of separate categories might be considered moredissimilar. This implies a similarity-dissimilarity competition between two basic classification processes. When focusing on sub-category similarity, one would expect more difficult classification when members of the same category become less similar (disregarding the increase of between-category dissimilarity); however, the between-category dissimilarity increase predicts a less difficult classification. Our categorization study suggests that participants rely more on using dissimilarities between opposite categories than finding similarities between sub-categories. We connect our results to rule- and exemplar-based classification models. The pattern of influences of within- and between-category similarities are challenging for simple single-process categorization systems based on rules or exemplars. Instead, our results suggest that either these processes should be integrated in a hybrid model, or that category learning operates by forming clusters within each category.

  20. Floristic similarity, diversity and endemism as indicators of refugia characteristics and needs in the West

    USGS Publications Warehouse

    Malanson, George P.; Zimmerman, Dale L.; Fagre, Daniel B.

    2015-01-01

    The floras of mountain ranges, and their similarity, beta diversity and endemism, are indicative of processes of community assembly; they are also the initial conditions for coming disassembly and reassembly in response to climate change. As such, these characteristics can inform thinking on refugia. The published floras or approximations for 42 mountain ranges in the three major mountain systems (Sierra-Cascades, Rocky Mountains and Great Basin ranges) across the western USA and southwestern Canada were analysed. The similarity is higher among the ranges of the Rockies while equally low among the ranges of the Sierra-Cascades and Great Basin. Mantel correlations of similarity with geographic distance are also higher for the Rocky Mountains. Endemism is relatively high, but is highest in the Sierra-Cascades (due to the Sierra Nevada as the single largest range) and lowest in the Great Basin, where assemblages are allochthonous. These differences indicate that the geologic substrates of the Cascade volcanoes, which are much younger than any others, play a role in addition to geographic isolation in community assembly. The pattern of similarity and endemism indicates that the ranges of the Cascades will not function well as stepping stones and the endemic species that they harbor may need more protection than those of the Rocky Mountains. The geometry of the ranges is complemented by geology in setting the stage for similarity and the potential for refugia across the West. Understanding the geographic template as initial conditions for the future can guide the forecast of refugia and related monitoring or protection efforts.

  1. Siloxane containing addition polyimides

    NASA Technical Reports Server (NTRS)

    Maudgal, S.; St. Clair, T. L.

    1984-01-01

    Addition polyimide oligomers have been synthesized from bis(gamma-aminopropyl) tetramethyldisiloxane and 3, 3', 4, 4'-benzophenonetetracarboxylic dianhydride using a variety of latent crosslinking groups as endcappers. The prepolymers were isolated and characterized for solubility (in amide, chlorinated and ether solvents), melt flow and cure properties. The most promising systems, maleimide and acetylene terminated prepolymers, were selected for detailed study. Graphite cloth reinforced composites were prepared and properties compared with those of graphite/Kerimid 601, a commercially available bismaleimide. Mixtures of the maleimide terminated system with Kerimid 601, in varying proportions, were also studied.

  2. Faces in places: humans and machines make similar face detection errors.

    PubMed

    't Hart, Bernard Marius; Abresch, Tilman Gerrit Jakob; Einhäuser, Wolfgang

    2011-01-01

    The human visual system seems to be particularly efficient at detecting faces. This efficiency sometimes comes at the cost of wrongfully seeing faces in arbitrary patterns, including famous examples such as a rock configuration on Mars or a toast's roast patterns. In machine vision, face detection has made considerable progress and has become a standard feature of many digital cameras. The arguably most wide-spread algorithm for such applications ("Viola-Jones" algorithm) achieves high detection rates at high computational efficiency. To what extent do the patterns that the algorithm mistakenly classifies as faces also fool humans? We selected three kinds of stimuli from real-life, first-person perspective movies based on the algorithm's output: correct detections ("real faces"), false positives ("illusory faces") and correctly rejected locations ("non faces"). Observers were shown pairs of these for 20 ms and had to direct their gaze to the location of the face. We found that illusory faces were mistaken for faces more frequently than non faces. In addition, rotation of the real face yielded more errors, while rotation of the illusory face yielded fewer errors. Using colored stimuli increases overall performance, but does not change the pattern of results. When replacing the eye movement by a manual response, however, the preference for illusory faces over non faces disappeared. Taken together, our data show that humans make similar face-detection errors as the Viola-Jones algorithm, when directing their gaze to briefly presented stimuli. In particular, the relative spatial arrangement of oriented filters seems of relevance. This suggests that efficient face detection in humans is likely to be pre-attentive and based on rather simple features as those encoded in the early visual system.

  3. Faces in Places: Humans and Machines Make Similar Face Detection Errors

    PubMed Central

    't Hart, Bernard Marius; Abresch, Tilman Gerrit Jakob; Einhäuser, Wolfgang

    2011-01-01

    The human visual system seems to be particularly efficient at detecting faces. This efficiency sometimes comes at the cost of wrongfully seeing faces in arbitrary patterns, including famous examples such as a rock configuration on Mars or a toast's roast patterns. In machine vision, face detection has made considerable progress and has become a standard feature of many digital cameras. The arguably most wide-spread algorithm for such applications (“Viola-Jones” algorithm) achieves high detection rates at high computational efficiency. To what extent do the patterns that the algorithm mistakenly classifies as faces also fool humans? We selected three kinds of stimuli from real-life, first-person perspective movies based on the algorithm's output: correct detections (“real faces”), false positives (“illusory faces”) and correctly rejected locations (“non faces”). Observers were shown pairs of these for 20 ms and had to direct their gaze to the location of the face. We found that illusory faces were mistaken for faces more frequently than non faces. In addition, rotation of the real face yielded more errors, while rotation of the illusory face yielded fewer errors. Using colored stimuli increases overall performance, but does not change the pattern of results. When replacing the eye movement by a manual response, however, the preference for illusory faces over non faces disappeared. Taken together, our data show that humans make similar face-detection errors as the Viola-Jones algorithm, when directing their gaze to briefly presented stimuli. In particular, the relative spatial arrangement of oriented filters seems of relevance. This suggests that efficient face detection in humans is likely to be pre-attentive and based on rather simple features as those encoded in the early visual system. PMID:21998653

  4. Similarity of Crocodilian and Avian Lungs Indicates Unidirectional Flow Is Ancestral for Archosaurs.

    PubMed

    Farmer, C G

    2015-12-01

    Patterns of airflow and pulmonary anatomy were studied in the American alligator (Alligator mississippiensis), the black caiman (Melanosuchus niger), the spectacled caiman (Caiman crocodilus), the dwarf crocodile (Osteolaemus tetraspis), the saltwater crocodile (Crocodylus porosus), the Nile crocodile (Crocodylus niloticus), and Morelet's crocodile (Crocodylus moreletii). In addition, anatomy was studied in the Orinoco crocodile (Crocodylus intermedius). Airflow was measured using heated thermistor flow meters and visualized by endoscopy during insufflation of aerosolized propolene glycol and glycerol. Computed tomography and gross dissection were used to visualize the anatomy. In all species studied a bird-like pattern of unidirectional flow was present, in which air flowed caudad in the cervical ventral bronchus and its branches during both lung inflation and deflation and craniad in dorsobronchi and their branches. Tubular pathways connected the secondary bronchi to each other and allowed air to flow from the dorsobronchi into the ventrobronchi. No evidence for anatomical valves was found, suggesting that aerodynamic valves cause the unidirectional flow. In vivo data from the American alligator showed that unidirectional flow is present during periods of breath-holding (apnea) and is powered by the beating heart, suggesting that this pattern of flow harnesses the heart as a pump for air. Unidirectional flow may also facilitate washout of stale gases from the lung, reducing the cost of breathing, respiratory evaporative water loss, heat loss through the heat of vaporization, and facilitating crypsis. The similarity in structure and function of the bird lung with pulmonary anatomy of this broad range of crocodilian species indicates that a similar morphology and pattern of unidirectional flow were present in the lungs of the common ancestor of crocodilians and birds. These data suggest a paradigm shift is needed in our understanding of the evolution of this

  5. Enhancer Responses to Similarly Distributed Antagonistic Gradients in Development

    PubMed Central

    Zinzen, Robert P; Papatsenko, Dmitri

    2007-01-01

    Formation of spatial gene expression patterns in development depends on transcriptional responses mediated by gene control regions, enhancers. Here, we explore possible responses of enhancers to overlapping gradients of antagonistic transcriptional regulators in the Drosophila embryo. Using quantitative models based on enhancer structure, we demonstrate how a pair of antagonistic transcription factor gradients with similar or even identical spatial distributions can lead to the formation of distinct gene expression domains along the embryo axes. The described mechanisms are sufficient to explain the formation of the anterior and the posterior knirps expression, the posterior hunchback expression domain, and the lateral stripes of rhomboid expression and of other ventral neurogenic ectodermal genes. The considered principles of interaction between antagonistic gradients at the enhancer level can also be applied to diverse developmental processes, such as domain specification in imaginal discs, or even eyespot pattern formation in the butterfly wing. PMID:17500585

  6. Platelet additive solution - electrolytes.

    PubMed

    Azuma, Hiroshi; Hirayama, Junichi; Akino, Mitsuaki; Ikeda, Hisami

    2011-06-01

    Recent attention to solutions that replace most or all plasma in platelet concentrates, while maintaining satisfactory platelet function, is motivated by the potential of plasma reduction or depletion to mitigate various transfusion-related adverse events. This report considers the electrolytic composition of previously described platelet additive solutions, in order to draw general conclusions about what is required for platelet function and longevity. The optimal concentrations of Na(+) and Cl(-) are 69-115 mM. The presence of both K(+) and Mg(2+) in platelet suspension at nearly physiological concentrations (3-5mM and 1.5-3mM, respectively) is indispensable for good preservation capacity because both electrolytes are required to prevent platelet activation. In contrast to K(+) and Mg(2+), Ca(2+) may not be important because no free Ca(2+) is available in M-sol, which showed excellent platelet preservation capacity at less than 5% plasma concentration. The importance of bicarbonate (approximately 40 mM) can be recognized when the platelets are suspended in additive solution under less than 5% residual plasma concentration.

  7. Bilateral Trade Flows and Income Distribution Similarity

    PubMed Central

    2016-01-01

    Current models of bilateral trade neglect the effects of income distribution. This paper addresses the issue by accounting for non-homothetic consumer preferences and hence investigating the role of income distribution in the context of the gravity model of trade. A theoretically justified gravity model is estimated for disaggregated trade data (Dollar volume is used as dependent variable) using a sample of 104 exporters and 108 importers for 1980–2003 to achieve two main goals. We define and calculate new measures of income distribution similarity and empirically confirm that greater similarity of income distribution between countries implies more trade. Using distribution-based measures as a proxy for demand similarities in gravity models, we find consistent and robust support for the hypothesis that countries with more similar income-distributions trade more with each other. The hypothesis is also confirmed at disaggregated level for differentiated product categories. PMID:27137462

  8. Similarities between catalase and cytosolic epoxide hydrolase.

    PubMed

    Guenthner, T M; Qato, M; Whalen, R; Glomb, S

    1989-01-01

    Cytosolic epoxide hydrolase, measured as trans-stilbene oxide hydrolase activity, was isolated and purified from human and guinea pig liver cytosol. Antiserum to the guinea pig liver preparation reacted strongly with bovine liver catalase. We determined that this lack of selectivity of the antiserum was due to catalase contamination of the epoxide hydrolase preparation. We also determined that several commercial catalase preparations are contaminated with cytosolic epoxide hydrolase. Our human epoxide hydrolase preparation contained no detectable catalase contamination, yet antiserum to this protein also cross-reacted slightly with catalase, indicating some intrinsic similarity between the two enzymes. We conclude that catalase and cytosolic epoxide hydrolase contain some similar immunogenic epitopes, and we surmise that similarities between the subunits of these two enzymes may lead to their partial copurification. Functional similarities between the two enzymes are also demonstrated, as several compounds that inhibit catalase are also shown to inhibit cytosolic epoxide hydrolase activity in the same concentration range and rank order.

  9. Evaluating Similarity Measures for Brain Image Registration.

    PubMed

    Razlighi, Q R; Kehtarnavaz, N; Yousefi, S

    2013-10-01

    Evaluation of similarity measures for image registration is a challenging problem due to its complex interaction with the underlying optimization, regularization, image type and modality. We propose a single performance metric, named robustness, as part of a new evaluation method which quantifies the effectiveness of similarity measures for brain image registration while eliminating the effects of the other parts of the registration process. We show empirically that similarity measures with higher robustness are more effective in registering degraded images and are also more successful in performing intermodal image registration. Further, we introduce a new similarity measure, called normalized spatial mutual information, for 3D brain image registration whose robustness is shown to be much higher than the existing ones. Consequently, it tolerates greater image degradation and provides more consistent outcomes for intermodal brain image registration.

  10. Heat transfer in geometrically similar cylinders

    NASA Technical Reports Server (NTRS)

    Riekert, P; Held, A

    1941-01-01

    The power and heat-stress conditions of geometrically similar engines are discussed. The advantages accruing from smaller cylinder dimensions are higher specific horsepower, lower weight per horsepower, lower piston temperature, and less frontal area, with reduced detonation tendency.

  11. HYPOTHESIS TESTING WITH THE SIMILARITY INDEX

    EPA Science Inventory

    Mulltilocus DNA fingerprinting methods have been used extensively to address genetic issues in wildlife populations. Hypotheses concerning population subdivision and differing levels of diversity can be addressed through the use of the similarity index (S), a band-sharing coeffic...

  12. Privacy-preserving matching of similar patients.

    PubMed

    Vatsalan, Dinusha; Christen, Peter

    2016-02-01

    The identification of similar entities represented by records in different databases has drawn considerable attention in many application areas, including in the health domain. One important type of entity matching application that is vital for quality healthcare analytics is the identification of similar patients, known as similar patient matching. A key component of identifying similar records is the calculation of similarity of the values in attributes (fields) between these records. Due to increasing privacy and confidentiality concerns, using the actual attribute values of patient records to identify similar records across different organizations is becoming non-trivial because the attributes in such records often contain highly sensitive information such as personal and medical details of patients. Therefore, the matching needs to be based on masked (encoded) values while being effective and efficient to allow matching of large databases. Bloom filter encoding has widely been used as an efficient masking technique for privacy-preserving matching of string and categorical values. However, no work on Bloom filter-based masking of numerical data, such as integer (e.g. age), floating point (e.g. body mass index), and modulus (numbers wrap around upon reaching a certain value, e.g. date and time), which are commonly required in the health domain, has been presented in the literature. We propose a framework with novel methods for masking numerical data using Bloom filters, thereby facilitating the calculation of similarities between records. We conduct an empirical study on publicly available real-world datasets which shows that our framework provides efficient masking and achieves similar matching accuracy compared to the matching of actual unencoded patient records.

  13. Interlinguistic similarity and language death dynamics

    NASA Astrophysics Data System (ADS)

    Mira, J.; Paredes, Á.

    2005-03-01

    We analyze the time evolution of a system of two coexisting languages (Castillian Spanish and Galician, both spoken in northwest Spain) in the framework of a model given by Abrams and Strogatz (Nature 424 (2003) 900). It is shown that, contrary to the model's initial prediction, a stable bilingual situation is possible if the languages in competition are similar enough. Similarity is described with a simple parameter, whose value can be estimated from fits of the data.

  14. Distorting limb design for dynamically similar locomotion.

    PubMed Central

    Bullimore, Sharon R.; Burn, Jeremy F.

    2004-01-01

    Terrestrial mammals of different sizes tend to move in a dynamically similar manner when travelling at speeds corresponding to equal values of the Froude number. This means that certain dimensionless locomotor parameters, including peak vertical ground reaction force relative to body weight, stride length relative to leg length and duty factor, are independent of animal size. The Froude number is consequently used to define equivalent speeds for mammals of different sizes. However, most musculoskeletal-tissue properties, including tendon elastic modulus, do not scale in a dynamically similar manner. Therefore, mammals could not be completely dynamically similar, even if perfectly geometrically similar. We argue that, for mammals to move in a dynamically similar manner, they must exhibit systematic 'distortions' of limb structure with size that compensate for the size independence of the tendon elastic modulus. An implication of this is that comparing mammals at equal Froude numbers cannot remove all size-dependent effects. We show that the previously published allometry of limb moment arms is sufficient to compensate for size-independent tendon properties. This suggests that it is an important factor in allowing mammals of different sizes to move in a dynamically similar manner. PMID:15058440

  15. Representational similarity analysis - connecting the branches of systems neuroscience.

    PubMed

    Kriegeskorte, Nikolaus; Mur, Marieke; Bandettini, Peter

    2008-01-01

    A FUNDAMENTAL CHALLENGE FOR SYSTEMS NEUROSCIENCE IS TO QUANTITATIVELY RELATE ITS THREE MAJOR BRANCHES OF RESEARCH: brain-activity measurement, behavioral measurement, and computational modeling. Using measured brain-activity patterns to evaluate computational network models is complicated by the need to define the correspondency between the units of the model and the channels of the brain-activity data, e.g., single-cell recordings or voxels from functional magnetic resonance imaging (fMRI). Similar correspondency problems complicate relating activity patterns between different modalities of brain-activity measurement (e.g., fMRI and invasive or scalp electrophysiology), and between subjects and species. In order to bridge these divides, we suggest abstracting from the activity patterns themselves and computing representational dissimilarity matrices (RDMs), which characterize the information carried by a given representation in a brain or model. Building on a rich psychological and mathematical literature on similarity analysis, we propose a new experimental and data-analytical framework called representational similarity analysis (RSA), in which multi-channel measures of neural activity are quantitatively related to each other and to computational theory and behavior by comparing RDMs. We demonstrate RSA by relating representations of visual objects as measured with fMRI in early visual cortex and the fusiform face area to computational models spanning a wide range of complexities. The RDMs are simultaneously related via second-level application of multidimensional scaling and tested using randomization and bootstrap techniques. We discuss the broad potential of RSA, including novel approaches to experimental design, and argue that these ideas, which have deep roots in psychology and neuroscience, will allow the integrated quantitative analysis of data from all three branches, thus contributing to a more unified systems neuroscience.

  16. Representational Similarity Analysis – Connecting the Branches of Systems Neuroscience

    PubMed Central

    Kriegeskorte, Nikolaus; Mur, Marieke; Bandettini, Peter

    2008-01-01

    A fundamental challenge for systems neuroscience is to quantitatively relate its three major branches of research: brain-activity measurement, behavioral measurement, and computational modeling. Using measured brain-activity patterns to evaluate computational network models is complicated by the need to define the correspondency between the units of the model and the channels of the brain-activity data, e.g., single-cell recordings or voxels from functional magnetic resonance imaging (fMRI). Similar correspondency problems complicate relating activity patterns between different modalities of brain-activity measurement (e.g., fMRI and invasive or scalp electrophysiology), and between subjects and species. In order to bridge these divides, we suggest abstracting from the activity patterns themselves and computing representational dissimilarity matrices (RDMs), which characterize the information carried by a given representation in a brain or model. Building on a rich psychological and mathematical literature on similarity analysis, we propose a new experimental and data-analytical framework called representational similarity analysis (RSA), in which multi-channel measures of neural activity are quantitatively related to each other and to computational theory and behavior by comparing RDMs. We demonstrate RSA by relating representations of visual objects as measured with fMRI in early visual cortex and the fusiform face area to computational models spanning a wide range of complexities. The RDMs are simultaneously related via second-level application of multidimensional scaling and tested using randomization and bootstrap techniques. We discuss the broad potential of RSA, including novel approaches to experimental design, and argue that these ideas, which have deep roots in psychology and neuroscience, will allow the integrated quantitative analysis of data from all three branches, thus contributing to a more unified systems neuroscience. PMID:19104670

  17. Additive composition, for gasoline

    SciTech Connect

    Vataru, M.

    1989-01-10

    An admixture is described that comprises Diesel fuel and an additive composition added thereto which is between about 0.05 to about 2.0 percent by weight of the fuel, the composition comprising: (a) between about 0.05 and 25% relative weight parts of an organic peroxide, and (b) between about 0.1 and 25% relative weight parts of detergent selected from the component group that consists of: (i) fatty amines; (ii) ethoxylated and propoxylated derivatives of fatty amines; (iii) fatty diamines; (iv) fatty imidazlines; (v) polymeric amines and derivatives thereof; (vi) combination of one or more of the (i) through (v) components with carboxylic acid or acids having from three to forth carbon atoms, (c) from about 99.0 to about 50% by weight of a hydrocarbon solvent.

  18. Teardrop bladder: additional considerations

    SciTech Connect

    Wechsler, R.J.; Brennan, R.E.

    1982-07-01

    Nine cases of teardrop bladder (TDB) seen at excretory urography are presented. In some of these patients, the iliopsoas muscles were at the upper limit of normal in size, and additional evaluation of the perivesical structures with computed tomography (CT) was necessary. CT demonstrated only hypertrophied muscles with or without perivesical fat. The psoas muscles and pelvic width were measured in 8 patients and compared with the measurements of a control group of males without TDB. Patients with TDB had large iliopsoas muscles and narrow pelves compared with the control group. The psoas muscle width/pelvic width ratio was significantly greater (p < 0.0005) in patients with TDB than in the control group, with values of 1.04 + 0.05 and 0.82 + 0.09, respectively. It is concluded that TDB is not an uncommon normal variant in black males. Both iliopsoas muscle hypertrophy and a narrow pelvis are factors that predispose a patient to TDB.

  19. New addition curing polyimides

    NASA Technical Reports Server (NTRS)

    Frimer, Aryeh A.; Cavano, Paul

    1991-01-01

    In an attempt to improve the thermal-oxidative stability (TOS) of PMR-type polymers, the use of 1,4-phenylenebis (phenylmaleic anhydride) PPMA, was evaluated. Two series of nadic end-capped addition curing polyimides were prepared by imidizing PPMA with either 4,4'-methylene dianiline or p-phenylenediamine. The first resulted in improved solubility and increased resin flow while the latter yielded a compression molded neat resin sample with a T(sub g) of 408 C, close to 70 C higher than PME-15. The performance of these materials in long term weight loss studies was below that of PMR-15, independent of post-cure conditions. These results can be rationalized in terms of the thermal lability of the pendant phenyl groups and the incomplete imidization of the sterically congested PPMA. The preparation of model compounds as well as future research directions are discussed.

  20. Perspectives on Additive Manufacturing

    NASA Astrophysics Data System (ADS)

    Bourell, David L.

    2016-07-01

    Additive manufacturing (AM) has skyrocketed in visibility commercially and in the public sector. This article describes the development of this field from early layered manufacturing approaches of photosculpture, topography, and material deposition. Certain precursors to modern AM processes are also briefly described. The growth of the field over the last 30 years is presented. Included is the standard delineation of AM technologies into seven broad categories. The economics of AM part generation is considered, and the impacts of the economics on application sectors are described. On the basis of current trends, the future outlook will include a convergence of AM fabricators, mass-produced AM fabricators, enabling of topology optimization designs, and specialization in the AM legal arena. Long-term developments with huge impact are organ printing and volume-based printing.

  1. Sewage sludge additive

    NASA Technical Reports Server (NTRS)

    Kalvinskas, J. J.; Mueller, W. A.; Ingham, J. D. (Inventor)

    1980-01-01

    The additive is for a raw sewage treatment process of the type where settling tanks are used for the purpose of permitting the suspended matter in the raw sewage to be settled as well as to permit adsorption of the dissolved contaminants in the water of the sewage. The sludge, which settles down to the bottom of the settling tank is extracted, pyrolyzed and activated to form activated carbon and ash which is mixed with the sewage prior to its introduction into the settling tank. The sludge does not provide all of the activated carbon and ash required for adequate treatment of the raw sewage. It is necessary to add carbon to the process and instead of expensive commercial carbon, coal is used to provide the carbon supplement.

  2. Sex Similarities in Verbal and Performance IQ Deficits Following Unilateral Cerebral Lesions.

    ERIC Educational Resources Information Center

    Herring, Sheldon; Reitan, Ralph M.

    1986-01-01

    Investigated whether men and women produced similar Verbal Intelligence Quotient (IQ) and Performance IQ patterns following unilateral cerebral lesions. No consistent evidence of Sex X Lesioned Hemisphere interactions was found. Differences in the lateralization effects between men and women were not reflected in direction or pattern but only in…

  3. Semantic similarity between ontologies at different scales

    SciTech Connect

    Zhang, Qingpeng; Haglin, David J.

    2016-04-01

    In the past decade, existing and new knowledge and datasets has been encoded in different ontologies for semantic web and biomedical research. The size of ontologies is often very large in terms of number of concepts and relationships, which makes the analysis of ontologies and the represented knowledge graph computational and time consuming. As the ontologies of various semantic web and biomedical applications usually show explicit hierarchical structures, it is interesting to explore the trade-offs between ontological scales and preservation/precision of results when we analyze ontologies. This paper presents the first effort of examining the capability of this idea via studying the relationship between scaling biomedical ontologies at different levels and the semantic similarity values. We evaluate the semantic similarity between three Gene Ontology slims (Plant, Yeast, and Candida, among which the latter two belong to the same kingdom—Fungi) using four popular measures commonly applied to biomedical ontologies (Resnik, Lin, Jiang-Conrath, and SimRel). The results of this study demonstrate that with proper selection of scaling levels and similarity measures, we can significantly reduce the size of ontologies without losing substantial detail. In particular, the performance of Jiang-Conrath and Lin are more reliable and stable than that of the other two in this experiment, as proven by (a) consistently showing that Yeast and Candida are more similar (as compared to Plant) at different scales, and (b) small deviations of the similarity values after excluding a majority of nodes from several lower scales. This study provides a deeper understanding of the application of semantic similarity to biomedical ontologies, and shed light on how to choose appropriate semantic similarity measures for biomedical engineering.

  4. Rejecting probability summation for radial frequency patterns, not so Quick!

    PubMed

    Baldwin, Alex S; Schmidtmann, Gunnar; Kingdom, Frederick A A; Hess, Robert F

    2016-05-01

    Radial frequency (RF) patterns are used to assess how the visual system processes shape. They are thought to be detected globally. This is supported by studies that have found summation for RF patterns to be greater than what is possible if the parts were being independently detected and performance only then improved with an increasing number of cycles by probability summation between them. However, the model of probability summation employed in these previous studies was based on High Threshold Theory (HTT), rather than Signal Detection Theory (SDT). We conducted rating scale experiments to investigate the receiver operating characteristics. We find these are of the curved form predicted by SDT, rather than the straight lines predicted by HTT. This means that to test probability summation we must use a model based on SDT. We conducted a set of summation experiments finding that thresholds decrease as the number of modulated cycles increases at approximately the same rate as previously found. As this could be consistent with either additive or probability summation, we performed maximum-likelihood fitting of a set of summation models (Matlab code provided in our Supplementary material) and assessed the fits using cross validation. We find we are not able to distinguish whether the responses to the parts of an RF pattern are combined by additive or probability summation, because the predictions are too similar. We present similar results for summation between separate RF patterns, suggesting that the summation process there may be the same as that within a single RF.

  5. Similarity Metrics for Closed Loop Dynamic Systems

    NASA Technical Reports Server (NTRS)

    Whorton, Mark S.; Yang, Lee C.; Bedrossian, Naz; Hall, Robert A.

    2008-01-01

    To what extent and in what ways can two closed-loop dynamic systems be said to be "similar?" This question arises in a wide range of dynamic systems modeling and control system design applications. For example, bounds on error models are fundamental to the controller optimization with modern control design methods. Metrics such as the structured singular value are direct measures of the degree to which properties such as stability or performance are maintained in the presence of specified uncertainties or variations in the plant model. Similarly, controls-related areas such as system identification, model reduction, and experimental model validation employ measures of similarity between multiple realizations of a dynamic system. Each area has its tools and approaches, with each tool more or less suited for one application or the other. Similarity in the context of closed-loop model validation via flight test is subtly different from error measures in the typical controls oriented application. Whereas similarity in a robust control context relates to plant variation and the attendant affect on stability and performance, in this context similarity metrics are sought that assess the relevance of a dynamic system test for the purpose of validating the stability and performance of a "similar" dynamic system. Similarity in the context of system identification is much more relevant than are robust control analogies in that errors between one dynamic system (the test article) and another (the nominal "design" model) are sought for the purpose of bounding the validity of a model for control design and analysis. Yet system identification typically involves open-loop plant models which are independent of the control system (with the exception of limited developments in closed-loop system identification which is nonetheless focused on obtaining open-loop plant models from closed-loop data). Moreover the objectives of system identification are not the same as a flight test and

  6. Patterning of cells through patterning of biology.

    PubMed

    Kala, A; Jain, P K; Friedman, S H

    2014-07-01

    For the first time, cells have been patterned on surfaces through the spatial manipulation of native gene expression. By manipulating the inherent biology of the cell, as opposed to the chemical nature of the surfaces they are attached to, we have created a potentially more flexible way of creating patterns of cells that does not depend on the substrate. This was accomplished by bringing an siRNA that targets the expression of pten under the control of light, by modifying it with photocleavable groups. This pten-targeting siRNA has been previously demonstrated to induce dissociation of cells from surfaces. We modified this siRNA with dimethoxy nitro phenyl ethyl photocleavable groups (DMNPE) to allow the activity of the siRNA, and hence pten knockdown, to be toggled with light. Using this approach we demonstrated light dependent cell dissociation only with a DMNPE modified siRNA that targets pten and not with control siRNAs. In addition we demonstrated the ability to make simple patterns of cells through the application of masks during irradiation.

  7. Self-Similar Compressible Free Vortices

    NASA Technical Reports Server (NTRS)

    vonEllenrieder, Karl

    1998-01-01

    Lie group methods are used to find both exact and numerical similarity solutions for compressible perturbations to all incompressible, two-dimensional, axisymmetric vortex reference flow. The reference flow vorticity satisfies an eigenvalue problem for which the solutions are a set of two-dimensional, self-similar, incompressible vortices. These solutions are augmented by deriving a conserved quantity for each eigenvalue, and identifying a Lie group which leaves the reference flow equations invariant. The partial differential equations governing the compressible perturbations to these reference flows are also invariant under the action of the same group. The similarity variables found with this group are used to determine the decay rates of the velocities and thermodynamic variables in the self-similar flows, and to reduce the governing partial differential equations to a set of ordinary differential equations. The ODE's are solved analytically and numerically for a Taylor vortex reference flow, and numerically for an Oseen vortex reference flow. The solutions are used to examine the dependencies of the temperature, density, entropy, dissipation and radial velocity on the Prandtl number. Also, experimental data on compressible free vortex flow are compared to the analytical results, the evolution of vortices from initial states which are not self-similar is discussed, and the energy transfer in a slightly-compressible vortex is considered.

  8. Efficient Video Similarity Measurement and Search

    SciTech Connect

    Cheung, Sen-ching S.

    2002-12-19

    The amount of information on the world wide web has grown enormously since its creation in 1990. Duplication of content is inevitable because there is no central management on the web. Studies have shown that many similar versions of the same text documents can be found throughout the web. This redundancy problem is more severe for multimedia content such as web video sequences, as they are often stored in multiple locations and different formats to facilitate downloading and streaming. Similar versions of the same video can also be found, unknown to content creators, when web users modify and republish original content using video editing tools. Identifying similar content can benefit many web applications and content owners. For example, it will reduce the number of similar answers to a web search and identify inappropriate use of copyright content. In this dissertation, they present a system architecture and corresponding algorithms to efficiently measure, search, and organize similar video sequences found on any large database such as the web.

  9. Predicting missing links via structural similarity

    NASA Astrophysics Data System (ADS)

    Lyu, Guo-Dong; Fan, Chang-Jun; Yu, Lian-Fei; Xiu, Bao-Xin; Zhang, Wei-Ming

    2015-04-01

    Predicting missing links in networks plays a significant role in modern science. On the basis of structural similarity, our paper proposes a new node-similarity-based measure called biased resource allocation (BRA), which is motivated by the resource allocation (RA) measure. Comparisons between BRA and nine well-known node-similarity-based measures on five real networks indicate that BRA performs no worse than RA, which was the best node-similarity-based index in previous researches. Afterwards, based on localPath (LP) and Katz measure, we propose another two improved measures, named Im-LocalPath and Im-Katz respectively. Numerical results show that the prediction accuracy of both Im-LP and Im-Katz measure improve compared with the original LP and Katz measure. Finally, a new path-similarity-based measure and its improved measure, called LYU and Im-LYU measure, are proposed and especially, Im-LYU measure is shown to perform more remarkably than other mentioned measures.

  10. Geometric similarity between protein-RNA interfaces.

    PubMed

    Zhou, Peng; Zou, Jianwei; Tian, Feifei; Shang, Zhicai

    2009-12-01

    A new method is described to measure the geometric similarity between protein-RNA interfaces quantitatively. The method is based on a procedure that dissects the interface geometry in terms of the spatial relationships between individual amino acid nucleotide pairs. Using this technique, we performed an all-on-all comparison of 586 protein-RNA interfaces deposited in the current Protein Data Bank, as the result, an interface-interface similarity score matrix was obtained. Based upon this matrix, hierarchical clustering was carried out which yielded a complete clustering tree for the 586 protein-RNA interfaces. By investigating the organizing behavior of the clustering tree and the SCOP classification of protein partners in complexes, a geometrically nonredundant, diverse data set (representative data set) consisting of 45 distinct protein-RNA interfaces was extracted for the purpose of studying protein-RNA interactions, RNA regulations, and drug design. We classified protein-RNA interfaces into three types. In type I, the families and interface structural classes of the protein partners, as well as the interface geometries are all similar. In type II, the interface geometries and the interface structural classes are similar, whereas the protein families are different. In type III, only the interface geometries are similar but the protein families and the interface structural classes are distinct. Furthermore, we also show two new RNA recognition themes derived from the representative data set.

  11. Determining similarity of scientific entities in annotation datasets.

    PubMed

    Palma, Guillermo; Vidal, Maria-Esther; Haag, Eric; Raschid, Louiqa; Thor, Andreas

    2015-01-01

    Linked Open Data initiatives have made available a diversity of scientific collections where scientists have annotated entities in the datasets with controlled vocabulary terms from ontologies. Annotations encode scientific knowledge, which is captured in annotation datasets. Determining relatedness between annotated entities becomes a building block for pattern mining, e.g. identifying drug-drug relationships may depend on the similarity of the targets that interact with each drug. A diversity of similarity measures has been proposed in the literature to compute relatedness between a pair of entities. Each measure exploits some knowledge including the name, function, relationships with other entities, taxonomic neighborhood and semantic knowledge. We propose a novel general-purpose annotation similarity measure called 'AnnSim' that measures the relatedness between two entities based on the similarity of their annotations. We model AnnSim as a 1-1 maximum weight bipartite match and exploit properties of existing solvers to provide an efficient solution. We empirically study the performance of AnnSim on real-world datasets of drugs and disease associations from clinical trials and relationships between drugs and (genomic) targets. Using baselines that include a variety of measures, we identify where AnnSim can provide a deeper understanding of the semantics underlying the relatedness of a pair of entities or where it could lead to predicting new links or identifying potential novel patterns. Although AnnSim does not exploit knowledge or properties of a particular domain, its performance compares well with a variety of state-of-the-art domain-specific measures. Database URL: http://www.yeastgenome.org/

  12. Determining similarity of scientific entities in annotation datasets

    PubMed Central

    Palma, Guillermo; Vidal, Maria-Esther; Haag, Eric; Raschid, Louiqa; Thor, Andreas

    2015-01-01

    Linked Open Data initiatives have made available a diversity of scientific collections where scientists have annotated entities in the datasets with controlled vocabulary terms from ontologies. Annotations encode scientific knowledge, which is captured in annotation datasets. Determining relatedness between annotated entities becomes a building block for pattern mining, e.g. identifying drug–drug relationships may depend on the similarity of the targets that interact with each drug. A diversity of similarity measures has been proposed in the literature to compute relatedness between a pair of entities. Each measure exploits some knowledge including the name, function, relationships with other entities, taxonomic neighborhood and semantic knowledge. We propose a novel general-purpose annotation similarity measure called ‘AnnSim’ that measures the relatedness between two entities based on the similarity of their annotations. We model AnnSim as a 1–1 maximum weight bipartite match and exploit properties of existing solvers to provide an efficient solution. We empirically study the performance of AnnSim on real-world datasets of drugs and disease associations from clinical trials and relationships between drugs and (genomic) targets. Using baselines that include a variety of measures, we identify where AnnSim can provide a deeper understanding of the semantics underlying the relatedness of a pair of entities or where it could lead to predicting new links or identifying potential novel patterns. Although AnnSim does not exploit knowledge or properties of a particular domain, its performance compares well with a variety of state-of-the-art domain-specific measures. Database URL: http://www.yeastgenome.org/ PMID:25725057

  13. Clinical patterns of phytodermatitis.

    PubMed

    Sasseville, Denis

    2009-07-01

    Exposure to plants is very common, through leisure or professional activity. In addition, plant products and botanic extracts are increasingly present in the environment. Cutaneous adverse reactions to plants and their derivatives occur fairly frequently, and establishing the correct diagnosis is not always easy. The astute clinician relies on a detailed history and a careful skin examination to substantiate his opinion. This article reviews the characteristic clinical patterns of phyto- and phytophotodermatitis and some less common presentations.

  14. Another Study of the Pronunciation of Words Ending in a Vowel-Consonant-Final E Pattern and Similar Patterns.

    ERIC Educational Resources Information Center

    Greif, Ivo P.

    In response to criticism of a previous study, this paper reports a revision of a proposed phonics rule "when there are two vowels, one of which is a final e, the first vowel is long and the final e is silent" (cradle), which is called the VCE (Vowel Consonant E) rule. Following an introductory section, the paper examines previous research, citing…

  15. Additive lattice kirigami.

    PubMed

    Castle, Toen; Sussman, Daniel M; Tanis, Michael; Kamien, Randall D

    2016-09-01

    Kirigami uses bending, folding, cutting, and pasting to create complex three-dimensional (3D) structures from a flat sheet. In the case of lattice kirigami, this cutting and rejoining introduces defects into an underlying 2D lattice in the form of points of nonzero Gaussian curvature. A set of simple rules was previously used to generate a wide variety of stepped structures; we now pare back these rules to their minimum. This allows us to describe a set of techniques that unify a wide variety of cut-and-paste actions under the rubric of lattice kirigami, including adding new material and rejoining material across arbitrary cuts in the sheet. We also explore the use of more complex lattices and the different structures that consequently arise. Regardless of the choice of lattice, creating complex structures may require multiple overlapping kirigami cuts, where subsequent cuts are not performed on a locally flat lattice. Our additive kirigami method describes such cuts, providing a simple methodology and a set of techniques to build a huge variety of complex 3D shapes.

  16. Additive lattice kirigami

    PubMed Central

    Castle, Toen; Sussman, Daniel M.; Tanis, Michael; Kamien, Randall D.

    2016-01-01

    Kirigami uses bending, folding, cutting, and pasting to create complex three-dimensional (3D) structures from a flat sheet. In the case of lattice kirigami, this cutting and rejoining introduces defects into an underlying 2D lattice in the form of points of nonzero Gaussian curvature. A set of simple rules was previously used to generate a wide variety of stepped structures; we now pare back these rules to their minimum. This allows us to describe a set of techniques that unify a wide variety of cut-and-paste actions under the rubric of lattice kirigami, including adding new material and rejoining material across arbitrary cuts in the sheet. We also explore the use of more complex lattices and the different structures that consequently arise. Regardless of the choice of lattice, creating complex structures may require multiple overlapping kirigami cuts, where subsequent cuts are not performed on a locally flat lattice. Our additive kirigami method describes such cuts, providing a simple methodology and a set of techniques to build a huge variety of complex 3D shapes. PMID:27679822

  17. Dreaming and waking: similarities and differences revisited.

    PubMed

    Kahan, Tracey L; LaBerge, Stephen P

    2011-09-01

    Dreaming is often characterized as lacking high-order cognitive (HOC) skills. In two studies, we test the alternative hypothesis that the dreaming mind is highly similar to the waking mind. Multiple experience samples were obtained from late-night REM sleep and waking, following a systematic protocol described in Kahan (2001). Results indicated that reported dreaming and waking experiences are surprisingly similar in their cognitive and sensory qualities. Concurrently, ratings of dreaming and waking experiences were markedly different on questions of general reality orientation and logical organization (e.g., the bizarreness or typicality of the events, actions, and locations). Consistent with other recent studies (e.g., Bulkeley & Kahan, 2008; Kozmová & Wolman, 2006), experiences sampled from dreaming and waking were more similar with respect to their process features than with respect to their structural features.

  18. Online Multiple Kernel Similarity Learning for Visual Search.

    PubMed

    Xia, Hao; Hoi, Steven C H; Jin, Rong; Zhao, Peilin

    2013-08-13

    Recent years have witnessed a number of studies on distance metric learning to improve visual similarity search in Content-Based Image Retrieval (CBIR). Despite their popularity and success, most existing methods on distance metric learning are limited in two aspects. First, they typically assume the target proximity function follows the family of Mahalanobis distances, which limits their capacity of measuring similarity of complex patterns in real applications. Second, they often cannot effectively handle the similarity measure of multi-modal data that may originate from multiple resources. To overcome these limitations, this paper investigates an online kernel ranking framework for learning kernel-based proximity functions, which goes beyond the conventional linear distance metric learning approaches. Based on the framework, we propose a novel Online Multiple Kernel Ranking (OMKR) method, which learns a flexible nonlinear proximity function with multiple kernels to improve visual similarity search in CBIR. We evaluate the proposed technique for CBIR on a variety of image data sets, in which encouraging results show that OMKR outperforms the state-of-the-art techniques significantly.

  19. Repeated parallel evolution reveals limiting similarity in subterranean diving beetles.

    PubMed

    Vergnon, Remi; Leijs, Remko; van Nes, Egbert H; Scheffer, Marten

    2013-07-01

    The theory of limiting similarity predicts that co-occurring species must be sufficiently different to coexist. Although this idea is a staple of community ecology, convincing empirical evidence has been scarce. Here we examine 34 subterranean beetle communities in arid inland Australia that share the same habitat type but have evolved in complete isolation over the past 5 million years. Although these communities come from a range of phylogenetic origins, we find that they have almost invariably evolved to share a similar size structure. The relative positions of coexisting species on the body size axis were significantly more regular across communities than would be expected by chance, with a size ratio, on average, of 1.6 between coexisting species. By contrast, species' absolute body sizes varied substantially from one community to the next. This suggests that self-organized spacing according to limiting-similarity theory, as opposed to evolution toward preexisting fixed niches, shaped the communities. Using a model starting from random sets of founder species, we demonstrate that the patterns are indeed consistent with evolutionary self-organization. For less isolated habitats, the same model predicts the coexistence of multiple species in each regularly spaced functional group. Limiting similarity, therefore, may also be compatible with the coexistence of many redundant species.

  20. Numerical study of similarity in prototype and model pumped turbines

    NASA Astrophysics Data System (ADS)

    Li, Z. J.; Wang, Z. W.; Bi, H. L.

    2014-03-01

    Similarity study of prototype and model pumped turbines are performed by numerical simulation and the partial discharge case is analysed in detail. It is found out that in the RSI (rotor-stator interaction) region where the flow is convectively accelerated with minor flow separation, a high level of similarity in flow patterns and pressure fluctuation appear with relative pressure fluctuation amplitude of model turbine slightly higher than that of prototype turbine. As for the condition in the runner where the flow is convectively accelerated with severe separation, similarity fades substantially due to different topology of flow separation and vortex formation brought by distinctive Reynolds numbers of the two turbines. In the draft tube where the flow is diffusively decelerated, similarity becomes debilitated owing to different vortex rope formation impacted by Reynolds number. It is noted that the pressure fluctuation amplitude and characteristic frequency of model turbine are larger than those of prototype turbine. The differences in pressure fluctuation characteristics are discussed theoretically through dimensionless Navier-Stokes equation. The above conclusions are all made based on simulation without regard to the penstock response and resonance.

  1. The similarity of life across the universe

    PubMed Central

    Cockell, Charles S.

    2016-01-01

    Is the hypothesis correct that if life exists elsewhere in the universe, it would have forms and structures unlike anything we could imagine? From the subatomic level in cellular energy acquisition to the assembly and even behavior of organisms at the scale of populations, life on Earth exhibits characteristics that suggest it is a universal norm for life at all levels of hierarchy. These patterns emerge from physical and biochemical limitations. Their potentially universal nature is supported by recent data on the astrophysical abundance and availability of carbon compounds and water. Within these constraints, biochemical and biological variation is certainly possible, but it is limited. If life exists elsewhere, life on Earth, rather than being a contingent product of one specific experiment in biological evolution, is likely to reflect common patterns for the assembly of living matter. PMID:27255694

  2. The similarity of life across the universe.

    PubMed

    Cockell, Charles S

    2016-05-15

    Is the hypothesis correct that if life exists elsewhere in the universe, it would have forms and structures unlike anything we could imagine? From the subatomic level in cellular energy acquisition to the assembly and even behavior of organisms at the scale of populations, life on Earth exhibits characteristics that suggest it is a universal norm for life at all levels of hierarchy. These patterns emerge from physical and biochemical limitations. Their potentially universal nature is supported by recent data on the astrophysical abundance and availability of carbon compounds and water. Within these constraints, biochemical and biological variation is certainly possible, but it is limited. If life exists elsewhere, life on Earth, rather than being a contingent product of one specific experiment in biological evolution, is likely to reflect common patterns for the assembly of living matter.

  3. Assessing intraplate volcano compositional similarities with cluster analysis

    NASA Astrophysics Data System (ADS)

    Konter, J. G.

    2012-12-01

    The compositional variation in intraplate volcanoes is commonly assessed as a function of end-members that were recognized as extrema in a 3D space, defined by radiogenic isotope ratios. The specific isotope ratios used are the principle components in the intraplate volcano compositional data set, and by reducing the dimensionality of the data set to 3, groupings and trends in the data can be visually identified. Such groupings can then be used to compare to other geochemical or geophysical data sets (e.g. correlations with seismic models). A complementary approach in examining groupings and trends in a data set is the use of cluster analysis, which can be used to recognize groups of similar intraplate volcanic systems. Since it is not known a priori how many clusters may exist, hierarchical cluster analysis can be used to examine the relationships between individual intraplate volcanic systems. The technique compares the Euclidian distance between the data available at the different locations, and this data can have a large number of dimensions. The results can be visualized as a dendrogram, where individual locations are represented by different branches (or leafs) that join at different distances. We use Matlab to examine the data extracted from pre-compiled GEOROC database files, including location, major elements, large ion lithophile elements, high field strength elements, rare earth elements and radiogenic isotopes. These data do not vary over the same range in values and are therefore first normalized by the total range in the data set for each particular element or isotope ratio. Since multiple samples have been analyzed for most intraplate volcanic systems, we assess the results for the average, the maximum, and the minimum values for each element. In addition, we investigate the robustness of the outcome by removing one element at a time from the data set and recalculating a new dendrogram. One of the outcomes is that the resulting clusters seem to

  4. Additive Construction using Basalt Regolith Fines

    NASA Technical Reports Server (NTRS)

    Mueller, Robert P.; Sibille, Laurent; Hintze, Paul E.; Lippitt, Thomas C.; Mantovani, James G.; Nugent, Matthew W.; Townsend, Ivan I.

    2014-01-01

    Planetary surfaces are often covered in regolith (crushed rock), whose geologic origin is largely basalt. The lunar surface is made of small-particulate regolith and areas of boulders located in the vicinity of craters. Regolith composition also varies with location, reflecting the local bedrock geology and the nature and efficiency of the micrometeorite-impact processes. In the lowland mare areas (suitable for habitation), the regolith is composed of small granules (20 - 100 microns average size) of mare basalt and volcanic glass. Impacting micrometeorites may cause local melting, and the formation of larger glassy particles, and this regolith may contain 10-80% glass. Studies of lunar regolith are traditionally conducted with lunar regolith simulant (reconstructed soil with compositions patterned after the lunar samples returned by Apollo). The NASA Kennedy Space Center (KSC) Granular Mechanics & Regolith Operations (GMRO) lab has identified a low fidelity but economical geo-technical simulant designated as Black Point-1 (BP-1). It was found at the site of the Arizona Desert Research and Technology Studies (RATS) analog field test site at the Black Point lava flow in adjacent basalt quarry spoil mounds. This paper summarizes activities at KSC regarding the utilization of BP-1 basalt regolith and comparative work with lunar basalt simulant JSC-1A as a building material for robotic additive construction of large structures. In an effort to reduce the import or in-situ fabrication of binder additives, we focused this work on in-situ processing of regolith for construction in a single-step process after its excavation. High-temperature melting of regolith involves techniques used in glassmaking and casting (with melts of lower density and higher viscosity than those of metals), producing basaltic glass with high durability and low abrasive wear. Most Lunar simulants melt at temperatures above 1100 C, although melt processing of terrestrial regolith at 1500 C is not

  5. Molecular fingerprint similarity search in virtual screening.

    PubMed

    Cereto-Massagué, Adrià; Ojeda, María José; Valls, Cristina; Mulero, Miquel; Garcia-Vallvé, Santiago; Pujadas, Gerard

    2015-01-01

    Molecular fingerprints have been used for a long time now in drug discovery and virtual screening. Their ease of use (requiring little to no configuration) and the speed at which substructure and similarity searches can be performed with them - paired with a virtual screening performance similar to other more complex methods - is the reason for their popularity. However, there are many types of fingerprints, each representing a different aspect of the molecule, which can greatly affect search performance. This review focuses on commonly used fingerprint algorithms, their usage in virtual screening, and the software packages and online tools that provide these algorithms.

  6. The collagenous gastroenteritides: similarities and differences.

    PubMed

    Gopal, Purva; McKenna, Barbara J

    2010-10-01

    Collagenous gastritis, collagenous sprue, and collagenous colitis share striking histologic similarities and occur together in some patients. They also share some drug and disease associations. Pediatric cases of collagenous gastritis, however, lack most of these associations. The etiologies of the collagenous gastroenteritides are not known, so it is not clear whether they are similar because they share pathogeneses, or because they indicate a common histologic response to varying injuries. The features, disease and drug associations, and the inquiries into the pathogenesis of these disorders are reviewed.

  7. Similarity Based Semantic Web Service Match

    NASA Astrophysics Data System (ADS)

    Peng, Hui; Niu, Wenjia; Huang, Ronghuai

    Semantic web service discovery aims at returning the most matching advertised services to the service requester by comparing the semantic of the request service with an advertised service. The semantic of a web service are described in terms of inputs, outputs, preconditions and results in Ontology Web Language for Service (OWL-S) which formalized by W3C. In this paper we proposed an algorithm to calculate the semantic similarity of two services by weighted averaging their inputs and outputs similarities. Case study and applications show the effectiveness of our algorithm in service match.

  8. Nuclear markers reveal that inter-lake cichlids' similar morphologies do not reflect similar genealogy.

    PubMed

    Kassam, Daud; Seki, Shingo; Horic, Michio; Yamaoka, Kosaku

    2006-08-01

    The apparent inter-lake morphological similarity among East African Great Lakes' cichlid species/genera has left evolutionary biologists asking whether such similarity is due to sharing of common ancestor or mere convergent evolution. In order to answer such question, we first used Geometric Morphometrics, GM, to quantify morphological similarity and then subsequently used Amplified Fragment Length Polymorphism, AFLP, to determine if similar morphologies imply shared ancestry or convergent evolution. GM revealed that not all presumed morphological similar pairs were indeed similar, and the dendrogram generated from AFLP data indicated distinct clusters corresponding to each lake and not inter-lake morphological similar pairs. Such results imply that the morphological similarity is due to convergent evolution and not shared ancestry. The congruency of GM and AFLP generated dendrograms imply that GM is capable of picking up phylogenetic signal, and thus GM can be potential tool in phylogenetic systematics.

  9. Understanding taxi travel patterns

    NASA Astrophysics Data System (ADS)

    Cai, Hua; Zhan, Xiaowei; Zhu, Ji; Jia, Xiaoping; Chiu, Anthony S. F.; Xu, Ming

    2016-09-01

    Taxis play important roles in modern urban transportation systems, especially in mega cities. While providing necessary amenities, taxis also significantly contribute to traffic congestion, urban energy consumption, and air pollution. Understanding the travel patterns of taxis is thus important for addressing many urban sustainability challenges. Previous research has primarily focused on examining the statistical properties of passenger trips, which include only taxi trips occupied with passengers. However, unoccupied trips are also important for urban sustainability issues because they represent potential opportunities to improve the efficiency of the transportation system. Therefore, we need to understand the travel patterns of taxis as an integrated system, instead of focusing only on the occupied trips. In this study we examine GPS trajectory data of 11,880 taxis in Beijing, China for a period of three weeks. Our results show that taxi travel patterns share similar traits with travel patterns of individuals but also exhibit differences. Trip displacement distribution of taxi travels is statistically greater than the exponential distribution and smaller than the truncated power-law distribution. The distribution of short trips (less than 30 miles) can be best fitted with power-law while long trips follow exponential decay. We use radius of gyration to characterize individual taxi's travel distance and find that it does not follow a truncated power-law as observed in previous studies. Spatial and temporal regularities exist in taxi travels. However, with increasing spatial coverage, taxi trips can exhibit dual high probability density centers.

  10. Great Apes' Capacities to Recognize Relational Similarity

    ERIC Educational Resources Information Center

    Haun, Daniel B. M.; Call, Josep

    2009-01-01

    Recognizing relational similarity relies on the ability to understand that defining object properties might not lie in the objects individually, but in the relations of the properties of various object to each other. This aptitude is highly relevant for many important human skills such as language, reasoning, categorization and understanding…

  11. Mental Institutions and Similar Phenomena Called Schools

    ERIC Educational Resources Information Center

    Fischer, Ronald W.

    1971-01-01

    Mental institutions and public schools appear to have many similarities, and they often operate in ways that would seem contradictory to their philosophy. This article explores certain atrocities to the self" that result from programs that are intended to be beneficial but, in reality, often result in dehumanization. (Author)

  12. The Case of the Similar Trees.

    ERIC Educational Resources Information Center

    Meyer, Rochelle Wilson

    1982-01-01

    A possible logical flaw based on similar triangles is discussed with the Sherlock Holmes mystery, "The Muskgrave Ritual." The possible flaw has to do with the need for two trees to have equal growth rates over a 250-year period in order for the solution presented to work. (MP)

  13. Recognizing Similarities between Fraction Word Problems.

    ERIC Educational Resources Information Center

    Hardiman, Pamela Thibodeau

    Deciding how to approach a word problem for solution is a critical stage of problem solving, and is the stage which frequently presents considerable difficulty for novices. Do novices use the same information that experts do in deciding that two problems would be solved similarly? This set of four studies indicates that novices rely more on…

  14. Similarity of Science Textbooks: A Content Analysis

    ERIC Educational Resources Information Center

    Yost, Michael

    1973-01-01

    Studied the similarity of the astronomy portion in five science textbooks at the fourth through sixth grade levels by comparing students' responses to text authors' requirements. Concluded that the texts had more in common across grade levels than within grade levels. (CC)

  15. Cognitive Similarity in Normal and Schizogenic Families.

    ERIC Educational Resources Information Center

    Leibowitz, Gerald

    The basic purpose of this study was to measure cognitive similarity, and to test the hypothesis that the cognitive organization of a child (normal or schizophrenic) is more like that of his own parents than it is like that of randomly chosen, unrelated adults. Thirty-six matched family triads, half with sons hospitalized for a schizophrenic…

  16. Equivalence classes of Fibonacci lattices and their similarity properties

    NASA Astrophysics Data System (ADS)

    Lo Gullo, N.; Vittadello, L.; Bazzan, M.; Dell'Anna, L.

    2016-08-01

    We investigate, theoretically and experimentally, the properties of Fibonacci lattices with arbitrary spacings. Different from periodic structures, the reciprocal lattice and the dynamical properties of Fibonacci lattices depend strongly on the lengths of their lattice parameters, even if the sequence of long and short segment, the Fibonacci string, is the same. In this work we show that by exploiting a self-similarity property of Fibonacci strings under a suitable composition rule, it is possible to define equivalence classes of Fibonacci lattices. We show that the diffraction patterns generated by Fibonacci lattices belonging to the same equivalence class can be rescaled to a common pattern of strong diffraction peaks thus giving to this classification a precise meaning. Furthermore we show that, through the gap labeling theorem, gaps in the energy spectra of Fibonacci crystals belonging to the same class can be labeled by the same momenta (up to a proper rescaling) and that the larger gaps correspond to the strong peaks of the diffraction spectra. This observation makes the definition of equivalence classes meaningful also for the spectral and therefore dynamical and thermodynamical properties of quasicrystals. Our results apply to the more general class of quasiperiodic lattices for which similarity under a suitable deflation rule is in order.

  17. Differential Patterns of Hypoperfusion in Subtypes of Mild Cognitive Impairment

    PubMed Central

    Caffarra, Paolo; Ghetti, Caterina; Concari, Letizia; Venneri, Annalena

    2008-01-01

    In this study the regional cerebral blood flow (rCBF) pattern of three Mild Cognitive Impairment (MCI) subtypes was measured with SPECT in 60 patients (nineteen with an amnestic deficit, sixteen with disexecutive deficits, and twenty five with mild multidomain deficits) and compared with that of 15 healthy matched older adults. The amnestic MCI subgroup showed significant hypoperfusion in the left hippocampus, parahippocampal gyrus and fronto-parieto-temporal areas. The disexecutive subgroup had significant hypoperfusion of the left superior, medial frontal and cingulate cortex. The multidomain subgroup had similar perfusion deficits to the amnestic subgroup, with an additional deficit in the left posterior cingulate gyrus. This study found differential patterns of hypoperfusion in MCI subtypes. Since all patients who progressed to dementia converted to probable Alzheimer’s disease, the different rCBF patterns most likely reflect the neuropathological heterogeneity at onset and differences in disease stage. PMID:19018314

  18. Regional Similarities in Seasonal Mortality across the United States: An Examination of 28 Metropolitan Statistical Areas

    PubMed Central

    Kalkstein, Adam J.

    2013-01-01

    Human mortality exhibits a strong seasonal pattern with deaths in winter far exceeding those in the summer. While the pattern itself is clear, there have been very few studies examining whether the magnitude or timing of seasonal mortality varies considerably across space. Thus, the goal of this study is to conduct a comprehensive geographic analysis of seasonal mortality across the United States and to uncover systematic regional differences in such mortality. Unique seasonal mortality curves were created for 28 metropolitan statistical areas across the United States, and the amplitude and timing of mortality peaks were determined. The findings here indicate that the seasonality of mortality exhibits strong spatial variation with the largest seasonal mortality amplitudes found in the southwestern United States and the smallest in the North, along with South Florida. In addition, there were strong intra-regional similarities that exist among the examined cities, implying that environmental factors are more important than social factors in determining seasonal mortality response. This work begins to fill a large gap within the scientific literature concerning the geographic variation and underlying causes of seasonal mortality across the United States. PMID:23734179

  19. Landscape similarity, retrieval, and machine mapping of physiographic units

    NASA Astrophysics Data System (ADS)

    Jasiewicz, Jaroslaw; Netzel, Pawel; Stepinski, Tomasz F.

    2014-09-01

    We introduce landscape similarity - a numerical measure that assesses affinity between two landscapes on the basis of similarity between the patterns of their constituent landform elements. Such a similarity function provides core technology for a landscape search engine - an algorithm that parses the topography of a study area and finds all places with landscapes broadly similar to a landscape template. A landscape search can yield answers to a query in real time, enabling a highly effective means to explore large topographic datasets. In turn, a landscape search facilitates auto-mapping of physiographic units within a study area. The country of Poland serves as a test bed for these novel concepts. The topography of Poland is given by a 30 m resolution DEM. The geomorphons method is applied to this DEM to classify the topography into ten common types of landform elements. A local landscape is represented by a square tile cut out of a map of landform elements. A histogram of cell-pair features is used to succinctly encode the composition and texture of a pattern within a local landscape. The affinity between two local landscapes is assessed using the Wave-Hedges similarity function applied to the two corresponding histograms. For a landscape search the study area is organized into a lattice of local landscapes. During the search the algorithm calculates the similarity between each local landscape and a given query. Our landscape search for Poland is implemented as a GeoWeb application called TerraEx-Pl and is available at http://sil.uc.edu/. Given a sample, or a number of samples, from a target physiographic unit the landscape search delineates this unit using the principles of supervised machine learning. Repeating this procedure for all units yields a complete physiographic map. The application of this methodology to topographic data of Poland results in the delineation of nine physiographic units. The resultant map bears a close resemblance to a conventional

  20. Fractal dimension of bioconvection patterns

    NASA Technical Reports Server (NTRS)

    Noever, David A.

    1990-01-01

    Shallow cultures of the motile algal strain, Euglena gracilis, were concentrated to 2 x 10 to the 6th organisms per ml and placed in constant temperature water baths at 24 and 38 C. Bioconvective patterns formed an open two-dimensional structure with random branches, similar to clusters encountered in the diffusion-limited aggregation (DLA) model. When averaged over several example cultures, the pattern was found to have no natural length scale, self-similar branching, and a fractal dimension (d about 1.7). These agree well with the two-dimensional DLA.

  1. Fractal Dimension of Bioconvection Patterns

    NASA Astrophysics Data System (ADS)

    Noever, David A.

    1990-10-01

    Shallow cultures of the motile algal strain, Euglena gracilis, were concentrated to 2× 106 organisms per ml and placed in constant temperature water baths at 24 and 38 C. Bioconvective patterns formed an open two-dimensional structure with random branches, similar to clusters encountered in the diffusion-limited aggregation (DLA) model. When averaged over several example cultures, the pattern was found to have no natural length scale, self-similar branching and a fractal dimension (d˜1.7). These agree well with the two-dimensional DLA.

  2. Quantifying Visual Similarity in Clinical Iconic Graphics

    PubMed Central

    Payne, Philip R.O.; Starren, Justin B.

    2005-01-01

    Objective: The use of icons and other graphical components in user interfaces has become nearly ubiquitous. The interpretation of such icons is based on the assumption that different users perceive the shapes similarly. At the most basic level, different users must agree on which shapes are similar and which are different. If this similarity can be measured, it may be usable as the basis to design better icons. Design: The purpose of this study was to evaluate a novel method for categorizing the visual similarity of graphical primitives, called Presentation Discovery, in the domain of mammography. Six domain experts were given 50 common textual mammography findings and asked to draw how they would represent those findings graphically. Nondomain experts sorted the resulting graphics into groups based on their visual characteristics. The resulting groups were then analyzed using traditional statistics and hypothesis discovery tools. Strength of agreement was evaluated using computational simulations of sorting behavior. Measurements: Sorter agreement was measured at both the individual graphical and concept-group levels using a novel simulation-based method. “Consensus clusters” of graphics were derived using a hierarchical clustering algorithm. Results: The multiple sorters were able to reliably group graphics into similar groups that strongly correlated with underlying domain concepts. Visual inspection of the resulting consensus clusters indicated that graphical primitives that could be informative in the design of icons were present. Conclusion: The method described provides a rigorous alternative to intuitive design processes frequently employed in the design of icons and other graphical interface components. PMID:15684136

  3. Predicted correspondence between species abundances and dendrograms of niche similarities

    PubMed Central

    Sugihara, George; Bersier, Louis-Félix; Southwood, T. Richard E.; Pimm, Stuart L.; May, Robert M.

    2003-01-01

    We examine a hypothesized relationship between two descriptions of community structure: the niche-overlap dendrogram that describes the ecological similarities of species and the pattern of relative abundances. Specifically, we examine the way in which this relationship follows from the niche hierarchy model, whose fundamental assumption is a direct connection between abundances and underlying hierarchical community organization. We test three important, although correlated, predictions of the niche hierarchy model and show that they are upheld in a set of 11 communities (encompassing fishes, amphibians, lizards, and birds) where both abundances and dendrograms were reported. First, species that are highly nested in the dendrogram are on average less abundant than species from branches less subdivided. Second, and more significantly, more equitable community abundances are associated with more evenly branched dendrogram structures, whereas less equitable abundances are associated with less even dendrograms. This relationship shows that abundance patterns can give insight into less visible aspects of community organization. Third, one can recover the distribution of proportional abundances seen in assemblages containing two species by treating each branch point in the dendrogram as a two-species case. This reconstruction cannot be achieved if abundances and the dendrogram are unrelated and suggests a method for hierarchically decomposing systems. To our knowledge, this is the first test of a species abundance model based on nontrivial predictions as to the origins and causes of abundance patterns, and not simply on the goodness-of-fit of distributions. PMID:12702773

  4. Correspondence analysis: a method for classifying similar patterns of violence against women.

    PubMed

    Mota, Jurema Corrêa da; Vasconcelos, Ana Gloria Godoi; Assis, Simone Gonçalves de

    2008-06-01

    Violence against women has received relatively little debate in society. It includes physical, psychological, and sexual abuse that jeopardizes the victim's health. Multivariate correspondence analysis and cluster analysis were applied to crimes reported to the Integrated Women's Aid Center in Rio de Janeiro, Brazil, to investigate associations between injury and define criteria for classifying the aggressions. Three groups of abuse were identified, differing according to the nature (physical, psychological, or sexual) and severity of the crimes. Less serious crimes consisted of threats and moderate physical injuries. The intermediate severity group included serious physical assault and threats. More serious crimes included death threats, rape, and sexual assault. The method thus allowed classification of the crimes in three groups according to severity.

  5. Tactile Perception and Friction-Induced Vibrations: Discrimination of Similarly Patterned Wood-Like Surfaces.

    PubMed

    Dacleu Ndengue, Jessica; Cesini, B Ilaria; Faucheu, C Jenny; Chatelet, D Eric; Zahouani, E Hassan; Delafosse, F David; Massi, G Francesco

    2016-12-22

    The tactile perception of a surface texture is mediated by factors such as material, topography and vibrations induced by the sliding contact. In this paper, sensory characterizations are developed together with topographical and tribo-tactile characterizations to relate perceived features with objective measurements of tribological and dynamic signals. Two sets of surface samples are used in this study: the first set is made of a commercial floor covering tiles that aim at counter-typing natural wood flooring, with both a visual and a tactile texture mimicking wood. A second set is custom-made by replicating the first set using a plain purple polyurethane resin. The comparison between tribo-tactile signals and sensory analysis allowed the identification of objective indices for textures with slight topographical differences. Even though the topography of the replicated samples is the same as their corresponding commercial products, the fact that the material is different, induces differences in the contact and vibrational parameters. This in turn modifies the discrimination performances during the sensory experiment. Tactile characteristics collected during sensory procedures are found to be in agreement with objective indices such as friction coefficients and induced vibrations.

  6. Similar brain activation patterns for writing logographic and phonetic symbols in Chinese.

    PubMed

    Lin, Chong-Yu; Xiao, Zhuang-Wei; Shen, Li; Zhang, John X; Weng, Xu-Chu

    2007-10-08

    This event-related functional MRI study examined the neural correlates for Chinese writing, by comparing the writing of logographic characters and that of pinyin, a phonetic notation system for Chinese characters. The temporal profile of the activations indicated that the middle frontal gyrus, superior parietal lobule, and posterior inferior temporal gyrus reflected more central processes for writing. Although pinyin writing elicited greater activity overall than character writing, the critical finding is that the two types of symbols recruited essentially the same brain regions. The results were compared with studies in Japanese showing dissociation between logographic kanji and phonetic kana writing and frequency of use was suggested to be an important factor in accounting for result differences across the two writing systems.

  7. Similarities and differences in crack cocaine use patterns in Santa Catarina, Brazil: Capital vs. Midwest.

    PubMed

    Zeferino, Maria Terezinha; Fermo, Vivian Costa; Fialho, Marcelo Brandt; Bastos, Francisco Inácio

    2017-01-01

    Crack cocaine has been a major public health problem in Brazil due to the individual and social harms and risks deriving from its use. This article aims to assess the characteristics of drug scenes in the capital and Midwest of Santa Catarina state. The project used the Time-Location Sampling. Between January and June 2011, 41 crack cocaine scenes were mapped in capital of Santa Catarina, whereas 33 were mapped in the Midwest of that state. Such scenes were randomly selected to be observed, as well as their days and shifts (time periods/day) for in-depth observation. Overall, 98 scenes/shifts were observed in the capital and 62 in the Midwest. First-hand reports were logged as field notes into notebooks. Analyses of the empirical material were based on Bardin's content analysis, and findings were compared and contrasted with Brazilian and international literature. Most crack cocaine users were adult males. In the capital, a substantial fraction of the users lived in the streets, but in both settings most interviewees have used multiple substances. In the Midwest, most scenes occurred at night, whereas in the capital scenes occurred in all shifts. Risk practices associated with the use of crack cocaine were: association of multiple drugs, prostitution, pipe sharing and sexual favors in exchange for the substance.

  8. Different but Similar: Computer Use Patterns between Young Korean Males and Females

    ERIC Educational Resources Information Center

    Lim, Keol; Meier, Ellen B.

    2011-01-01

    This study was developed to identify and describe new trends and gender differences in the use of computers and the Internet in South Korea. In this mixed-method study, both quantitative and qualitative techniques were used. Results indicated that both males and females used computers generally for four purposes: social networking, personal…

  9. Six- and 9-Month-Old Infants Discriminate between Goals Despite Similar Action Patterns

    ERIC Educational Resources Information Center

    Marsh, Heidi L.; Stavropoulos, Jennifer; Nienhuis, Tom; Legerstee, Maria

    2010-01-01

    Behne, Carpenter, Call, and Tomasello (2005) showed that 9- to 18-month-olds, but not 6-month-olds, differentiated between people who were unwilling and unable to share toys. As the outcome of the two tasks is the same (i.e., the toy is not shared), the infants must respond to the different goals of the actor. However, visual habituation paradigms…

  10. Low-Income, African American Adolescent Mothers and Their Toddlers Exhibit Similar Dietary Variety Patterns

    ERIC Educational Resources Information Center

    Papas, Mia A.; Hurley, Kristen M.; Quigg, Anna M.; Oberlander, Sarah E.; Black, Maureen M.

    2009-01-01

    Objective: To examine the relationship between maternal and toddler dietary variety. Design: Longitudinal; maternal and toddler dietary data were collected at 13 months; anthropometry was collected at 13 and 24 months. Setting: Data were collected in homes. Participants: 109 primiparous, low-income, African American adolescent mothers and…

  11. Magnetic Assisted Colloidal Pattern Formation

    NASA Astrophysics Data System (ADS)

    Yang, Ye

    phase transitions in condensed matter systems that can be tracked with single particle resolution. Compared with other research on colloidal crystal formation, my research has focused on multi-component colloidal systems of magnetic and non-magnetic colloids immersed in a ferrofluid. Initially, I studied the types of patterns that form as a function of the concentrations of the different particles and ferrofluid, and I discovered a wide variety of chains, rings and crystals forming in bi-component and tri-component systems. Based on these results, I narrowed my focus to one specific crystal structure (checkerboard lattice) as a model of phase transformations in alloy. Liquid/solid phase transitions were studied by slowly adjusting the magnetic field strength, which serves to control particle-particle interactions in a manner similar to controlling the physical temperature of the fluid. These studies were used to determine the optimal conditions for forming large single crystal structures, and paved the way for my later work on solid/solid phase transitions when the angle of the external field was shifted away from the normal direction. The magnetostriction coefficient of these crystals was measured in low tilt angle of the applied field. At high tilt angles, I observed a variety of martensitic transformations, which followed different pathways depending on the crystal direction relative to the in-plane field. In the last part of my doctoral studies, I investigated colloidal patterns formed in a superimposed acoustic and magnetic field. In this approach, the magnetic field mimics "temperature", while the acoustic field mimics "pressure". The ability to simultaneously tune both temperature and pressure allows for more efficient exploration of phase space. With this technique I demonstrated a large class of particle structures ranging from discrete molecule-like clusters to well ordered crystal phases. Additionally, I demonstrated a crosslinking strategy based on

  12. Polar Polygon Patterns

    NASA Technical Reports Server (NTRS)

    2003-01-01

    MGS MOC Release No. MOC2-338, 22 April 2003

    This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image was taken during southern spring, as the seasonal carbon dioxide frost cap was subliming away. Frost remaining in shallow cracks and depressions reveals a fantastic polygonal pattern. Similar polygons occur in the Earth's arctic and antarctic regions-on Earth such polygons are related to the freeze and thaw of ground ice. The picture covers an area about 3 km (about 1.9 mi) wide near 71.9oS, 11.1oW. Sunlight illuminates the scene from the left.

  13. Detecting Patterns of Anomalies

    DTIC Science & Technology

    2009-03-01

    ct)P (bt|ct) , where A,B and C are mutually exclusive subsets of attributes with at most k elements . This ratio is similar to the previous formula , but...AND SUBTITLE Detecting Patterns of Anomalies 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) 5d. PROJECT NUMBER 5e...to be dependent if, µ(A,B) ≥ βµ (2.1) where, βµ is a threshold parameter, set to a low value of 0.1 ( empirically ) in our experi- ments. Thus, for a

  14. Cognitive patterns: giving autonomy some context

    NASA Astrophysics Data System (ADS)

    Dumond, Danielle; Stacy, Webb; Geyer, Alexandra; Rousseau, Jeffrey; Therrien, Mike

    2013-05-01

    Today's robots require a great deal of control and supervision, and are unable to intelligently respond to unanticipated and novel situations. Interactions between an operator and even a single robot take place exclusively at a very low, detailed level, in part because no contextual information about a situation is conveyed or utilized to make the interaction more effective and less time consuming. Moreover, the robot control and sensing systems do not learn from experience and, therefore, do not become better with time or apply previous knowledge to new situations. With multi-robot teams, human operators, in addition to managing the low-level details of navigation and sensor management while operating single robots, are also required to manage inter-robot interactions. To make the most use of robots in combat environments, it will be necessary to have the capability to assign them new missions (including providing them context information), and to have them report information about the environment they encounter as they proceed with their mission. The Cognitive Patterns Knowledge Generation system (CPKG) has the ability to connect to various knowledge-based models, multiple sensors, and to a human operator. The CPKG system comprises three major internal components: Pattern Generation, Perception/Action, and Adaptation, enabling it to create situationally-relevant abstract patterns, match sensory input to a suitable abstract pattern in a multilayered top-down/bottom-up fashion similar to the mechanisms used for visual perception in the brain, and generate new abstract patterns. The CPKG allows the operator to focus on things other than the operation of the robot(s).

  15. Effects of Spatial Frequency Similarity and Dissimilarity on Contour Integration

    PubMed Central

    Persike, Malte; Meinhardt, Günter

    2015-01-01

    We examined the effects of spatial frequency similarity and dissimilarity on human contour integration under various conditions of uncertainty. Participants performed a temporal 2AFC contour detection task. Spatial frequency jitter up to 3.0 octaves was applied either to background elements, or to contour and background elements, or to none of both. Results converge on four major findings. (1) Contours defined by spatial frequency similarity alone are only scarcely visible, suggesting the absence of specialized cortical routines for shape detection based on spatial frequency similarity. (2) When orientation collinearity and spatial frequency similarity are combined along a contour, performance amplifies far beyond probability summation when compared to the fully heterogenous condition but only to a margin compatible with probability summation when compared to the fully homogenous case. (3) Psychometric functions are steeper but not shifted for homogenous contours in heterogenous backgrounds indicating an advantageous signal-to-noise ratio. The additional similarity cue therefore not so much improves contour detection performance but primarily reduces observer uncertainty about whether a potential candidate is a contour or just a false positive. (4) Contour integration is a broadband mechanism which is only moderately impaired by spatial frequency dissimilarity. PMID:26057620

  16. Effects of Spatial Frequency Similarity and Dissimilarity on Contour Integration.

    PubMed

    Persike, Malte; Meinhardt, Günter

    2015-01-01

    We examined the effects of spatial frequency similarity and dissimilarity on human contour integration under various conditions of uncertainty. Participants performed a temporal 2AFC contour detection task. Spatial frequency jitter up to 3.0 octaves was applied either to background elements, or to contour and background elements, or to none of both. Results converge on four major findings. (1) Contours defined by spatial frequency similarity alone are only scarcely visible, suggesting the absence of specialized cortical routines for shape detection based on spatial frequency similarity. (2) When orientation collinearity and spatial frequency similarity are combined along a contour, performance amplifies far beyond probability summation when compared to the fully heterogenous condition but only to a margin compatible with probability summation when compared to the fully homogenous case. (3) Psychometric functions are steeper but not shifted for homogenous contours in heterogenous backgrounds indicating an advantageous signal-to-noise ratio. The additional similarity cue therefore not so much improves contour detection performance but primarily reduces observer uncertainty about whether a potential candidate is a contour or just a false positive. (4) Contour integration is a broadband mechanism which is only moderately impaired by spatial frequency dissimilarity.

  17. A topological similarity measure for proteins.

    PubMed

    Máté, Gabriell; Hofmann, Andreas; Wenzel, Nicolas; Heermann, Dieter W

    2014-04-01

    We introduce a new measure for assessing similarity among chemical structures, based on well-established computational-topology algorithms. We argue that although the method considers geometry, it is more than a mere geometric similarity measure, as it takes into account, on different geometric scales, the important topological features of the compared structures. We prove that our measure is rigorous and complies with the proper mathematical requirements. We validate the method through comparing different configurations of simple zinc finger proteins and present an application on ligands binding to membrane-proteINS extracted from the Directory of Useful Decoys: Enhanced database and corresponding decoys. This article is part of a Special Issue entitled: Viral membrane proteins - Channels for cellular networking.

  18. Comparative Similarity in Branching Space-Times

    NASA Astrophysics Data System (ADS)

    Placek, Tomasz

    2010-12-01

    My aim in this paper is to investigate the notions of comparative similarity definable in the framework of branching space-times. A notion of this kind is required to give a rigorous Lewis-style semantics of space-time counterfactuals. In turn, the semantical analysis is needed to decide whether the recently proposed proofs of the non-locality of quantum mechanics are correct. From among the three notions of comparative similarity I select two which appear equally good as far as their intuitiveness and algebraic properties are concerned. However, the relations are not transitive, and thus cannot be used in the semantics proposed by Lewis (J. Philos. Log. 2:418-446, 1973), which requires transitivity. Yet they are adequate for the account of Lewis (J. Philos. Log. 10:217-234, 1981).

  19. Generative Models for Similarity-based Classification

    DTIC Science & Technology

    2007-01-01

    problem of estimating the class-conditional similarity probability models is solved by applying the maximum entropy principle, under the constraint that...model. The SDA class-conditional probability models have exponential form, because they are derived as the maximum entropy distribu- tions subject to...exist because the constraints are based on the data. As prescribed by Jaynes’ principle of maximum entropy [34], a unique class- conditional joint

  20. Optimal dynamic discrimination of similar quantum systems

    NASA Astrophysics Data System (ADS)

    Li, Baiqing

    2005-07-01

    The techniques for identifying and separating similar molecules have always been very important to chemistry and other branches of science and engineering. Similar quantum systems share comparable Hamiltonians, so their eigenenergy levels, transition dipole moments, and therefore their ordinary observable properties are alike. Traditional analytical methods have mostly been restricted by working with the subtle differences in the physical and chemical properties of the similar species. Optimal Dynamic Discrimination (ODD) aims at magnifying the dissimilarity of the agents by actively controlling their quantum evolution, drawing on the extremely rich information embedded in their dynamics. ODD is developed based on the tremendous flexibility of Optimal Control Theory (OCT) and on the practical implementation of closed-loop learning control, which has become a more and more indispensable tool for controlling quantum processes. The ODD experimental paradigm is designed to combat a number of factors that are detrimental to the discrimination of similar molecules: laser pulse noise, signal detection errors, finite time resolution in the signals, and environmental decoherence effects. It utilizes either static signals or time series signal, the latter capable of providing more information. Simulations are performed in this dissertation progressing from the wave function to the density matrix formulation, in order to study the decoherence effects. Analysis of the results reveals the roles of the adverse factors, unravels the underlying mechanisms of ODD, and provides insights on laboratory implementation. ODD emphasizes the incorporation of algorithmic development and laboratory design, and seeks to bridge the gap between theoretical/computational chemistry and experimental chemistry, with the help from applied mathematics and computer science.

  1. Explosion Source Similarity Analysis via SVD

    NASA Astrophysics Data System (ADS)

    Yedlin, Matthew; Ben Horin, Yochai; Margrave, Gary

    2016-04-01

    An important seismological ingredient for establishing a regional seismic nuclear discriminant is the similarity analysis of a sequence of explosion sources. To investigate source similarity, we are fortunate to have access to a sequence of 1805 three-component recordings of quarry blasts, shot from March 2002 to January 2015. The centroid of these blasts has an estimated location 36.3E and 29.9N. All blasts were detonated by JPMC (Jordan Phosphate Mines Co.) All data were recorded at the Israeli NDC, HFRI, located at 30.03N and 35.03E. Data were first winnowed based on the distribution of maximum amplitudes in the neighborhood of the P-wave arrival. The winnowed data were then detrended using the algorithm of Cleveland et al (1990). The detrended data were bandpass filtered between .1 to 12 Hz using an eighth order Butterworth filter. Finally, data were sorted based on maximum trace amplitude. Two similarity analysis approaches were used. First, for each component, the entire suite of traces was decomposed into its eigenvector representation, by employing singular-valued decomposition (SVD). The data were then reconstructed using 10 percent of the singular values, with the resulting enhancement of the S-wave and surface wave arrivals. The results of this first method are then compared to the second analysis method based on the eigenface decomposition analysis of Turk and Pentland (1991). While both methods yield similar results in enhancement of data arrivals and reduction of data redundancy, more analysis is required to calibrate the recorded data to charge size, a quantity that was not available for the current study. References Cleveland, R. B., Cleveland, W. S., McRae, J. E., and Terpenning, I., Stl: A seasonal-trend decomposition procedure based on loess, Journal of Official Statistics, 6, No. 1, 3-73, 1990. Turk, M. and Pentland, A., Eigenfaces for recognition. Journal of cognitive neuroscience, 3(1), 71-86, 1991.

  2. Quantification of Health by Scaling Similarity Judgments

    PubMed Central

    Arons, Alexander M. M.; Krabbe, Paul F. M.

    2014-01-01

    Objective A new methodology is introduced to scale health states on an interval scale based on similarity responses. It could be well suited for valuation of health states on specific regions of the health continuum that are problematic when applying conventional valuation techniques. These regions are the top-end, bottom-end, and states around ‘dead’. Methods Three samples of approximately 500 respondents were recruited via an online survey. Each sample received a different judgmental task in which similarity data were elicited for the top seven health states in the dementia quality of life instrument (DQI). These states were ‘111111’ (no problems on any domain) and six others with some problems (level 2) on one domain. The tasks presented two (dyads), three (triads), or four (quads) DQI health states. Similarity data were transformed into interval-level scales with metric and non-metric multidimensional scaling algorithms. The three response tasks were assessed for their feasibility and comprehension. Results In total 532, 469, and 509 respondents participated in the dyads, triads, and quads tasks respectively. After the scaling procedure, in all three response tasks, the best health state ‘111111’ was positioned at one end of the health-state continuum and state ‘111211’ was positioned at the other. The correlation between the metric scales ranged from 0.73 to 0.95, while the non-metric scales ranged from 0.76 to 1.00, indicating strong to near perfect associations. There were no apparent differences in the reported difficulty of the response tasks, but the triads had the highest number of drop-outs. Discussion Multidimensional scaling proved to be a feasible method to scale health-state similarity data. The dyads and especially the quads response tasks warrant further investigation, as these tasks provided the best indications of respondent comprehension. PMID:24586520

  3. Self-similar scalar field collapse

    NASA Astrophysics Data System (ADS)

    Banerjee, Narayan; Chakrabarti, Soumya

    2017-01-01

    A spherically symmetric collapsing scalar field model is discussed with a dissipative fluid which includes a heat flux. This vastly general matter distribution is analyzed at the expense of a high degree of symmetry in the space-time, that of conformal flatness and self-similarity. Indeed collapsing models terminating into a curvature singularity can be obtained. The formation of black holes or the occurrence of naked singularities depends on the initial collapsing profiles.

  4. [Samuel Hahnemann and the principle of similars].

    PubMed

    Schmidt, Josef M

    2010-01-01

    The principle of similars (treat likes by likes) is generally considered to be one of the pillars of the homeopathic doctrine established by Samuel Hahnemann (1755-1843). Nevertheless, its status and relevance with regard to the practice of homeopathy can be challenged by semantic, conceptual, and epistemological objections. 1. Contrary to its literal meaning, "similia similibus curentur" is commonly used in the sense of "all diseases should be treated by similar drug diseases", thus transgressing its original field of indication. 2. From 1796, when Hahnemann published his first definition of the principle of similars, he gradually raised his claims from merely suggesting a heuristic principle for finding new curative remedies to insisting on having discovered a law of nature and the only true way of healing, in 1807/1808. To substantiate his ambitious tenets, Hahnemann had to introduce a variety of theories which in turn were to become the main battleground in the ensuing controversy about homeopathy. 3. From the perspective of epistemology of science, science can never consist of a final set of absolute truths or the like but must rather be described as a continuous social process that retains a methodological cycle of abduction, deduction, and induction. From the perspective of theory of medicine, however, medicine is to be considered as a practical rather than a cognitive science in its own right. Its first concern ought to be the development of practical directions for treating patients, while the value of competing theories can only be judged from their usefulness in practice. Hence, even though Hahnemann's theories, including his conception of the principle of similars, may be untenable or outdated, the genuine method of homeopathic treatment he founded remains independent of and unaffected by criticism at the level of theory and concepts.

  5. Wind Turbine Experiments at Full Dynamic Similarity

    NASA Astrophysics Data System (ADS)

    Miller, Mark; Kiefer, Janik; Westergaard, Carsten; Hultmark, Marcus

    2015-11-01

    Performing experiments with scaled-down wind turbines has traditionally been difficult due to the matching requirements of the two driving non-dimensional parameters, the Tip Speed Ratio (TSR) and the Reynolds number. Typically, full-size turbines must be used to provide the baseline cases for engineering models and computer simulations where flow similarity is required. We present a new approach to investigating wind turbine aerodynamics at full dynamic similarity by employing a high-pressure wind tunnel at Princeton University known as the High Reynolds number Test Facility (or HRTF). This facility allows for Reynolds numbers of up to 3 million (based on chord and velocity at the tip) while still matching the TSR, on a geometrically similar, small-scale model. The background development of this project is briefly presented including the design and manufacture of a model turbine. Following this the power, thrust and wake data are discussed, in particular the scaling dependence on the Reynolds number. Supported under NSF grant CBET-1435254 (program manager Gregory Rorrer).

  6. SEROLOGICAL SIMILARITY OF FLAGELLAR AND MITOTIC MICROTUBULES

    PubMed Central

    Fulton, Chandler; Kane, R. E.; Stephens, R. E.

    1971-01-01

    An antiserum to flagellar axonemes from sperm of Arbacia punctulata contains antibodies which react both with intact flagellar outer fibers and with purified tubulin from the outer fibers. Immunodiffusion tests indicate the presence of similar antigenic determinants on outer-fiber tubulins from sperm flagella of five species of sea urchins and a sand dollar, but not a starfish. The antibodies also react with extracts containing tubulins from different classes of microtubules, including central-pair fibers and both A- and B-subfibers from outer fibers of sperm flagella, an extract from unfertilized eggs, mitotic apparatuses from first cleavage embryos, and cilia from later embryos. Though most tubulins tested share similar antigenic determinants, some clear differences have been detected, even, in Pseudoboletia indiana, between the outer-fiber tubulins of sperm flagella and blastular cilia. Though tubulins are "actin-like" proteins, antitubulin serum does not react with actin from sea urchin lantern muscle. On the basis of these observations, we suggest that various echinoid microtubules are built of similar, but not identical, tubulins. PMID:4106543

  7. Effects of similarity on environmental context cueing.

    PubMed

    Smith, Steven M; Handy, Justin D; Angello, Genna; Manzano, Isabel

    2014-01-01

    Three experiments examined the prediction that context cues which are similar to study contexts can facilitate episodic recall, even if those cues are never seen before the recall test. Environmental context cueing effects have typically produced such small effect sizes that influences of moderating factors, such as the similarity between encoding and retrieval contexts, would be difficult to observe experimentally. Videos of environmental contexts, however, can be used to produce powerful context-dependent memory effects, particularly when only one memory target is associated with each video context, intentional item-context encoding is encouraged, and free recall tests are used. Experiment 1 showed that a not previously viewed video of the study context provided an effective recall cue, although it was not as effective as the originally viewed video context. Experiments 2 and 3 showed that videos of environments that were conceptually similar to encoding contexts (e.g., both were videos of ball field games) also cued recall, but not as well if the encoding contexts were given specific labels (e.g., "home run") incompatible with test contexts (e.g., a soccer scene). A fourth experiment that used incidental item-context encoding showed that video context reinstatement has a robust effect on paired associate memory, indicating that the video context reinstatement effect does not depend on interactive item-context encoding or free recall testing.

  8. Octreotide and pasireotide (dis)similarly inhibit pituitary tumor cells in vitro.

    PubMed

    Ibáñez-Costa, Alejandro; Rivero-Cortés, Esther; Vázquez-Borrego, Mari C; Gahete, Manuel D; Jiménez-Reina, Luis; Venegas-Moreno, Eva; de la Riva, Andrés; Arráez, Miguel Ángel; González-Molero, Inmaculada; Schmid, Herbert A; Maraver-Selfa, Silvia; Gavilán-Villarejo, Inmaculada; García-Arnés, Juan Antonio; Japón, Miguel A; Soto-Moreno, Alfonso; Gálvez, María A; Luque, Raúl M; Castaño, Justo P

    2016-11-01

    Somatostatin analogs (SSA) are the mainstay of pharmacological treatment for pituitary adenomas. However, some patients escape from therapy with octreotide, a somatostatin receptor 2 (sst2)-preferring SSA, and pasireotide, a novel multi-sst-preferring SSA, may help to overcome this problem. It has been proposed that correspondence between sst1-sst5 expression pattern and SSA-binding profile could predict patient's response. To explore the cellular/molecular features associated with octreotide/pasireotide response, we performed a parallel comparison of their in vitro effects, evaluating sst1-sst5 expression, intracellular Ca(2+) signaling ([Ca(2+)]i), hormone secretion and cell viability, in a series of 85 pituitary samples. Somatotropinomas expressed sst5>sst2, yet octreotide reduced [Ca(2+)]i more efficiently than pasireotide, while both SSA similarly decreased growth hormone release/expression and viability. Corticotropinomas predominantly expressed sst5, but displayed limited response to pasireotide, while octreotide reduced functional endpoints. Non-functioning adenomas preferentially expressed sst3 but, surprisingly, both SSA increased cell viability. Prolactinomas mainly expressed sst1 but were virtually unresponsive to SSA. Finally, both SSA decreased [Ca(2+)]i in normal pituitaries. In conclusion, both SSA act in vitro on pituitary adenomas exerting both similar and distinct effects; however, no evident correspondence was found with the sst1-sst5 profile. Thus, it seems plausible that additional factors, besides the simple abundance of a given sst, critically influence the SSA response.

  9. Does language about similarity play a role in fostering similarity comparison in children?

    PubMed

    Ozçalişkan, Seyda; Goldin-Meadow, Susan; Gentner, Dedre; Mylander, Carolyn

    2009-08-01

    Commenting on perceptual similarities between objects stands out as an important linguistic achievement, one that may pave the way towards noticing and commenting on more abstract relational commonalities between objects. To explore whether having a conventional linguistic system is necessary for children to comment on different types of similarity comparisons, we observed four children who had not been exposed to usable linguistic input--deaf children whose hearing losses prevented them from learning spoken language and whose hearing parents had not exposed them to sign language. These children developed gesture systems that have language-like structure at many different levels. Here we ask whether the deaf children used their gestures to comment on similarity relations and, if so, which types of relations they expressed. We found that all four deaf children were able to use their gestures to express similarity comparisons (point to cat+point to tiger) resembling those conveyed by 40 hearing children in early gesture+speech combinations (cat+point to tiger). However, the two groups diverged at later ages. Hearing children, after acquiring the word like, shifted from primarily expressing global similarity (as in cat/tiger) to primarily expressing single-property similarity (as in crayon is brown like my hair). In contrast, the deaf children, lacking an explicit term for similarity, continued to primarily express global similarity. The findings underscore the robustness of similarity comparisons in human communication, but also highlight the importance of conventional terms for comparison as likely contributors to routinely expressing more focused similarity relations.

  10. A Statistical Model of Protein Sequence Similarity and Function Similarity Reveals Overly-Specific Function Predictions

    PubMed Central

    Kolker, Eugene

    2009-01-01

    Background Predicting protein function from primary sequence is an important open problem in modern biology. Not only are there many thousands of proteins of unknown function, current approaches for predicting function must be improved upon. One problem in particular is overly-specific function predictions which we address here with a new statistical model of the relationship between protein sequence similarity and protein function similarity. Methodology Our statistical model is based on sets of proteins with experimentally validated functions and numeric measures of function specificity and function similarity derived from the Gene Ontology. The model predicts the similarity of function between two proteins given their amino acid sequence similarity measured by statistics from the BLAST sequence alignment algorithm. A novel aspect of our model is that it predicts the degree of function similarity shared between two proteins over a continuous range of sequence similarity, facilitating prediction of function with an appropriate level of specificity. Significance Our model shows nearly exact function similarity for proteins with high sequence similarity (bit score >244.7, e-value >1e−62, non-redundant NCBI protein database (NRDB)) and only small likelihood of specific function match for proteins with low sequence similarity (bit score <54.6, e-value <1e−05, NRDB). For sequence similarity ranges in between our annotation model shows an increasing relationship between function similarity and sequence similarity, but with considerable variability. We applied the model to a large set of proteins of unknown function, and predicted functions for thousands of these proteins ranging from general to very specific. We also applied the model to a data set of proteins with previously assigned, specific functions that were electronically based. We show that, on average, these prior function predictions are more specific (quite possibly overly-specific) compared to

  11. Referred pain from trapezius muscle trigger points shares similar characteristics with chronic tension type headache.

    PubMed

    Fernández-de-Las-Peñas, César; Ge, Hong-You; Arendt-Nielsen, Lars; Cuadrado, Maria Luz; Pareja, Juan A

    2007-05-01

    Referred pain and pain characteristics evoked from the upper trapezius muscle was investigated in 20 patients with chronic tension-type headache (CTTH) and 20 age- and gender-matched controls. A headache diary was kept for 4 weeks in order to confirm the diagnosis and record the pain history. Both upper trapezius muscles were examined for the presence of myofascial trigger points (TrPs) in a blinded fashion. The local and referred pain intensities, referred pain pattern, and pressure pain threshold (PPT) were recorded. The results show that referred pain was evoked in 85% and 50% on the dominant and non-dominant sides in CTTH patients, much higher than 55% and 25% in controls (P<0.01). Referred pain spread to the posterior-lateral aspect of the neck ipsi-lateral to the stimulated muscle in both patients and controls, with additional referral to the temple in most patients, but none in controls. Nearly half of the CTTH patients (45%) recognized the referred pain as their usual headache sensation, i.e. active TrPs. CTTH patients with active TrPs in the right upper trapezius muscle showed greater headache intensity and frequency, and longer headache duration than those with latent TrPs. CTTH patients with bilateral TrPs reported significantly decreased PPT than those with unilateral TrP (P<0.01). Our results showed that manual exploration of TrPs in the upper trapezius muscle elicited referred pain patterns in both CTTH patients and healthy subjects. In CTTH patients, the evoked referred pain and its sensory characteristics shared similar patterns as their habitual headache pain, consistent with active TrPs. Our results suggest that spatial summation of perceived pain and mechanical pain sensitivity exists in CTTH patients.

  12. A bayesian approach to deformed pattern matching of iris images.

    PubMed

    Thornton, Jason; Savvides, Marios; Vijaya Kumar, B V K

    2007-04-01

    We describe a general probabilistic framework for matching patterns that experience in-plane nonlinear deformations, such as iris patterns. Given a pair of images, we derive a maximum a posteriori probability (MAP) estimate of the parameters of the relative deformation between them. Our estimation process accomplishes two things simultaneously: It normalizes for pattern warping and it returns a distortion-tolerant similarity metric which can be used for matching two nonlinearly deformed image patterns. The prior probability of the deformation parameters is specific to the pattern-type and, therefore, should result in more accurate matching than an arbitrary general distribution. We show that the proposed method is very well suited for handling iris biometrics, applying it to two databases of iris images which contain real instances of warped patterns. We demonstrate a significant improvement in matching accuracy using the proposed deformed Bayesian matching methodology. We also show that the additional computation required to estimate the deformation is relatively inexpensive, making it suitable for real-time applications.

  13. Tsunamis and meteorological tsunamis: similarities and differences

    NASA Astrophysics Data System (ADS)

    Rabinovich, A. B.; Monserrat, S.

    2003-04-01

    Destructive seiche oscillations occasionally generated in certain bays and inlets are mainly associated with two natural forcing phenomena: Seismic activity (tsunamis), and atmospheric disturbances (meteotsunamis). Despite their different origin, both types are modified and amplified by topography in a similar way and produce similar catastrophic effects in coastal areas. Due to these similarities, it is often difficult to distinguish between these two phenomena without knowing the exact source characteristics. Recognition and separation of these phenomena is important for the revision/improvement of existing tsunami catalogues but also to better understand the generation mechanism and mitigate their possible catastrophic effects. To investigate this problem and to compare seismic and meteorological tsunamis, we assembled a number of cases when both phenomena had been recorded at the same place. In particular, our findings included Alicante (Mediterranean coast of Spain), Malokurilsk and Krabovaya bays (Shikotan Island, Russia), and Tofino, Winter Harbour, Bamfield, Port Hardy, and Victoria (British Columbia, Canada). We also used the results of the LAST-97 hydrophysical experiment when eight bottom pressure stations were deployed on the shelf and in the inlets of Menorca Island (Western Meditterranean, Spain) and three precise microbarographs were working on the coast. Our analysis is based on the assumption that both tsunamis and meteotsunamis are formed by the combined effects of external forcing and topography. So, for different events recorded at the same site, the similarities are related to topography and the differences to the forcing. On the contrary, for the same event recorded at different stations, similarities are mainly associated with the forcing and the differences with specific local topographic features. Analysis of the spectral distributions and comparison with background noise enabled us to reconstruct the topographic transfer functions for all

  14. Acoustic and perceptual similarity of North German and American English vowels

    NASA Astrophysics Data System (ADS)

    Strange, Winifred; Bohn, Ocke-Schwen; Trent, Sonja A.; Nishi, Kanae

    2004-04-01

    Current theories of cross-language speech perception claim that patterns of perceptual assimilation of non-native segments to native categories predict relative difficulties in learning to perceive (and produce) non-native phones. Cross-language spectral similarity of North German (NG) and American English (AE) vowels produced in isolated hVC(a) (di)syllables (study 1) and in hVC syllables embedded in a short sentence (study 2) was determined by discriminant analyses, to examine the extent to which acoustic similarity was predictive of perceptual similarity patterns. The perceptual assimilation of NG vowels to native AE vowel categories by AE listeners with no German language experience was then assessed directly. Both studies showed that acoustic similarity of AE and NG vowels did not always predict perceptual similarity, especially for ``new'' NG front rounded vowels and for ``similar'' NG front and back mid and mid-low vowels. Both acoustic and perceptual similarity of NG and AE vowels varied as a function of the prosodic context, although vowel duration differences did not affect perceptual assimilation patterns. When duration and spectral similarity were in conflict, AE listeners assimilated vowels on the basis of spectral similarity in both prosodic contexts.

  15. Humans process dog and human facial affect in similar ways.

    PubMed

    Schirmer, Annett; Seow, Cui Shan; Penney, Trevor B

    2013-01-01

    Humans share aspects of their facial affect with other species such as dogs. Here we asked whether untrained human observers with and without dog experience are sensitive to these aspects and recognize dog affect with better-than-chance accuracy. Additionally, we explored similarities in the way observers process dog and human expressions. The stimulus material comprised naturalistic facial expressions of pet dogs and human infants obtained through positive (i.e., play) and negative (i.e., social isolation) provocation. Affect recognition was assessed explicitly in a rating task using full face images and images cropped to reveal the eye region only. Additionally, affect recognition was assessed implicitly in a lexical decision task using full faces as primes and emotional words and pseudowords as targets. We found that untrained human observers rated full face dog expressions from the positive and negative condition more accurately than would be expected by chance. Although dog experience was unnecessary for this effect, it significantly facilitated performance. Additionally, we observed a range of similarities between human and dog face processing. First, the facial expressions of both species facilitated lexical decisions to affectively congruous target words suggesting that their processing was equally automatic. Second, both dog and human negative expressions were recognized from both full and cropped faces. Third, female observers were more sensitive to affective information than were male observers and this difference was comparable for dog and human expressions. Together, these results extend existing work on cross-species similarities in facial emotions and provide evidence that these similarities are naturally exploited when humans interact with dogs.

  16. Humans Process Dog and Human Facial Affect in Similar Ways

    PubMed Central

    Schirmer, Annett; Seow, Cui Shan; Penney, Trevor B.

    2013-01-01

    Humans share aspects of their facial affect with other species such as dogs. Here we asked whether untrained human observers with and without dog experience are sensitive to these aspects and recognize dog affect with better-than-chance accuracy. Additionally, we explored similarities in the way observers process dog and human expressions. The stimulus material comprised naturalistic facial expressions of pet dogs and human infants obtained through positive (i.e., play) and negative (i.e., social isolation) provocation. Affect recognition was assessed explicitly in a rating task using full face images and images cropped to reveal the eye region only. Additionally, affect recognition was assessed implicitly in a lexical decision task using full faces as primes and emotional words and pseudowords as targets. We found that untrained human observers rated full face dog expressions from the positive and negative condition more accurately than would be expected by chance. Although dog experience was unnecessary for this effect, it significantly facilitated performance. Additionally, we observed a range of similarities between human and dog face processing. First, the facial expressions of both species facilitated lexical decisions to affectively congruous target words suggesting that their processing was equally automatic. Second, both dog and human negative expressions were recognized from both full and cropped faces. Third, female observers were more sensitive to affective information than were male observers and this difference was comparable for dog and human expressions. Together, these results extend existing work on cross-species similarities in facial emotions and provide evidence that these similarities are naturally exploited when humans interact with dogs. PMID:24023954

  17. How similar are two-unit bicycle and motorcycle crashes?

    PubMed

    Haworth, Narelle; Debnath, Ashim Kumar

    2013-09-01

    This paper explores the similarities and differences between bicycle and motorcycle crashes with other motor vehicles. If similar treatments can be effective for both bicycle and motorcycle crashes, then greater benefits in terms of crash costs saved may be possible for the same investment in treatments. To reduce the biases associated with under-reporting of these crashes to police, property damage and minor injury crashes were excluded. The most common crash type for both bicycles (31.1%) and motorcycles (24.5%) was intersection from adjacent approaches. Drivers of other vehicles were coded most at fault in the majority of two-unit bicycle (57.0%) and motorcycle crashes (62.7%). The crash types, patterns of fault and factors affecting fault were generally similar for bicycle and motorcycle crashes. This confirms the need to combat the factors contributing to failure of other drivers to yield right of way to two-wheelers, and suggest that some of these actions should prove beneficial to the safety of both motorized and non-motorized two-wheelers. In contrast, child bicyclists were more often at fault, particularly in crashes involving a vehicle leaving the driveway or footpath. The greater reporting of violations by riders and drivers in motorcycle crashes also deserves further investigation.

  18. Sensitivity to Phonological Similarity Within and Across Languages

    PubMed Central

    Blumenfeld, Henrike K.; Boukrina, Olga V.

    2009-01-01

    The influence of phonological similarity on bilingual language processing was examined within and across languages in three experiments. Phonological similarity was manipulated within a language by varying neighborhood density, and across languages by varying extent of cross-linguistic overlap between native and non-native languages. In Experiment 1, speed and accuracy of bilinguals’ picture naming were susceptible to phonological neighborhood density in both the first and the second language. In Experiment 2, eye-movement patterns indicated that the time-course of language activation varied across phonological neighborhood densities and across native/non-native language status. In Experiment 3, speed and accuracy of bilingual performance in an auditory lexical decision task were influenced by degree of cross-linguistic phonological overlap. Together, the three experiments confirm that bilinguals are sensitive to phonological similarity within and across languages and suggest that this sensitivity is asymmetrical across native and non-native languages and varies along the timecourse of word processing. PMID:18041587

  19. 21 CFR 170.18 - Tolerances for related food additives.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Tolerances for related food additives. 170.18... (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) FOOD ADDITIVES General Provisions § 170.18 Tolerances for related food additives. (a) Food additives that cause similar or related pharmacological effects will...

  20. 21 CFR 570.18 - Tolerances for related food additives.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... for related food additives. (a) Food additives that cause similar or related pharmacological effects... effects and will be considered as related food additives. (b) Tolerances established for such related food... accomplish the physical or technical effect for which such combined additives are intended and that...

  1. Dynamics of ultrasonic additive manufacturing.

    PubMed

    Hehr, Adam; Dapino, Marcelo J

    2017-01-01

    Ultrasonic additive manufacturing (UAM) is a solid-state technology for joining similar and dissimilar metal foils near room temperature by scrubbing them together with ultrasonic vibrations under pressure. Structural dynamics of the welding assembly and work piece influence how energy is transferred during the process and ultimately, part quality. To understand the effect of structural dynamics during UAM, a linear time-invariant model is proposed to relate the inputs of shear force and electric current to resultant welder velocity and voltage. Measured frequency response and operating performance of the welder under no load is used to identify model parameters. Using this model and in-situ measurements, shear force and welder efficiency are estimated to be near 2000N and 80% when welding Al 6061-H18 weld foil, respectively. Shear force and welder efficiency have never been estimated before in UAM. The influence of processing conditions, i.e., welder amplitude, normal force, and weld speed, on shear force and welder efficiency are investigated. Welder velocity was found to strongly influence the shear force magnitude and efficiency while normal force and weld speed showed little to no influence. The proposed model is used to describe high frequency harmonic content in the velocity response of the welder during welding operations and coupling of the UAM build with the welder.

  2. Similarity, Separability, and the Triangle Inequality.

    ERIC Educational Resources Information Center

    Tversky, Amos; Gati, Itamar

    1982-01-01

    The coincidence hypothesis predicts that dissimilarity between objects that differ on two separable dimensions is larger than predicted from their unidimensional differences on the basis of triangle inequality and segmental additivity. The coincidence hypothesis was supported in two-dimensional stimuli studies. (Author/CM)

  3. Oblique patterned etching of vertical silicon sidewalls

    SciTech Connect

    Burckel, D. Bruce; Finnegan, Patrick S.; Henry, M. David; Resnick, Paul J.; Jarecki, Jr., Robert L.

    2016-04-05

    A method for patterning on vertical silicon surfaces in high aspect ratio silicontopography is presented. A Faraday cage is used to direct energetic reactive ions obliquely through a patterned suspended membrane positioned over the topography. The technique is capable of forming high-fidelity pattern (100 nm) features, adding an additional fabrication capability to standard top-down fabrication approaches.

  4. Oblique patterned etching of vertical silicon sidewalls

    NASA Astrophysics Data System (ADS)

    Bruce Burckel, D.; Finnegan, Patrick S.; David Henry, M.; Resnick, Paul J.; Jarecki, Robert L.

    2016-04-01

    A method for patterning on vertical silicon surfaces in high aspect ratio silicon topography is presented. A Faraday cage is used to direct energetic reactive ions obliquely through a patterned suspended membrane positioned over the topography. The technique is capable of forming high-fidelity pattern (100 nm) features, adding an additional fabrication capability to standard top-down fabrication approaches.

  5. Additives in fibers and fabrics.

    PubMed Central

    Barker, R H

    1975-01-01

    The additives and contaminants which occur in textile fibers vary widely, depending on the type of fiber and the pretreatment which it has received. Synthetic fibers such as nylon and polyester contain trace amounts of contaminants such as catalysts and catalyst deactivators which remain after the synthesis of the basic polymers. In addition, there are frequently a number of materials which are added to perform specific functions in almost all man-made fibers. Examples of these would include traces of metals or metal salts used as tracers for identification of specific lots of fiber, TiO2 or similar materials added as delustrants, and a host of organic species added for such special purposes as antistatic agents or flame retardants. There may also be considerable quantities of residual monomer or small oligomers dissolved in the polymer matrix. The situation becomes even more complex after the fibers are converted into fabric form. Numerous materials are applied at various stages of fabric preparation to act as lubricants, sizing agents, antistats, bleaches, and wetting agents to facilitate the processing, but these are normally removed before the fabric reaches the cutters of the ultimate consumers and therefore usually do not constitute potential hazards. However, there are many other chemical agents which are frequently added during the later stages of fabric preparation and which are not designed to be removed. Aside from dyes and printing pigments, the most common additive for apparel fabrics is a durable press treatment. This generally involves the use of materials capable of crosslinking cellulosics by reacting through such functions as N-methylolated amides or related compounds such as ureas and carbamates. These materials pose some potential hazards due to both the nitrogenous bases and the formaldehyde which they usually release. There is usually also some residual catalyst in fabrics which have received such treatments. Other types of chemical treatments

  6. Joint Effect of Habitat Identity and Spatial Distance on Spiders’ Community Similarity in a Fragmented Transition Zone

    PubMed Central

    Ziv, Yaron

    2016-01-01

    Understanding the main processes that affect community similarity have been the focus of much ecological research. However, the relative effects of environmental and spatial aspects in structuring ecological communities is still unresolved and is probably scale-dependent. Here, we examine the effect of habitat identity and spatial distance on fine-grained community similarity within a biogeographic transition zone. We compared four hypotheses: i) habitat identity alone, ii) spatial proximity alone, iii) non-interactive effects of both habitat identity and spatial proximity, and iv) interactive effect of habitat identity and spatial proximity. We explored these hypotheses for spiders in three fragmented landscapes located along the sharp climatic gradient of Southern Judea Lowlands (SJL), Israel. We sampled 14,854 spiders (from 199 species or morphospecies) in 644 samples, taken in 35 patches and stratified to nine different habitats. We calculated the Bray-Curtis similarity between all samples-pairs. We divided the pairwise values to four functional distance categories (same patch, different patches from the same landscape, adjacent landscapes and distant landscapes) and two habitat categories (same or different habitats) and compared them using non-parametric MANOVA. A significant interaction between habitat identity and spatial distance was found, such that the difference in mean similarity between same-habitat pairs and different-habitat pairs decreases with spatial distance. Additionally, community similarity decayed with spatial distance. Furthermore, at all distances, same-habitat pairs had higher similarity than different-habitats pairs. Our results support the fourth hypothesis of interactive effect of habitat identity and spatial proximity. We suggest that the environmental complexity of habitats or increased habitat specificity of species near the edge of their distribution range may explain this pattern. Thus, in transitions zones care should be taken

  7. Joint Effect of Habitat Identity and Spatial Distance on Spiders' Community Similarity in a Fragmented Transition Zone.

    PubMed

    Gavish, Yoni; Ziv, Yaron

    2016-01-01

    Understanding the main processes that affect community similarity have been the focus of much ecological research. However, the relative effects of environmental and spatial aspects in structuring ecological communities is still unresolved and is probably scale-dependent. Here, we examine the effect of habitat identity and spatial distance on fine-grained community similarity within a biogeographic transition zone. We compared four hypotheses: i) habitat identity alone, ii) spatial proximity alone, iii) non-interactive effects of both habitat identity and spatial proximity, and iv) interactive effect of habitat identity and spatial proximity. We explored these hypotheses for spiders in three fragmented landscapes located along the sharp climatic gradient of Southern Judea Lowlands (SJL), Israel. We sampled 14,854 spiders (from 199 species or morphospecies) in 644 samples, taken in 35 patches and stratified to nine different habitats. We calculated the Bray-Curtis similarity between all samples-pairs. We divided the pairwise values to four functional distance categories (same patch, different patches from the same landscape, adjacent landscapes and distant landscapes) and two habitat categories (same or different habitats) and compared them using non-parametric MANOVA. A significant interaction between habitat identity and spatial distance was found, such that the difference in mean similarity between same-habitat pairs and different-habitat pairs decreases with spatial distance. Additionally, community similarity decayed with spatial distance. Furthermore, at all distances, same-habitat pairs had higher similarity than different-habitats pairs. Our results support the fourth hypothesis of interactive effect of habitat identity and spatial proximity. We suggest that the environmental complexity of habitats or increased habitat specificity of species near the edge of their distribution range may explain this pattern. Thus, in transitions zones care should be taken

  8. Similarities between decapod and insect neuropeptidomes.

    PubMed

    Veenstra, Jan A

    2016-01-01

    Background. Neuropeptides are important regulators of physiological processes and behavior. Although they tend to be generally well conserved, recent results using trancriptome sequencing on decapod crustaceans give the impression of significant differences between species, raising the question whether such differences are real or artefacts. Methods. The BLAST+ program was used to find short reads coding neuropeptides and neurohormons in publicly available short read archives. Such reads were then used to find similar reads in the same archives, and the DNA assembly program Trinity was employed to construct contigs encoding the neuropeptide precursors as completely as possible. Results. The seven decapod species analyzed in this fashion, the crabs Eriocheir sinensis, Carcinus maenas and Scylla paramamosain, the shrimp Litopenaeus vannamei, the lobster Homarus americanus, the fresh water prawn Macrobrachium rosenbergii and the crayfish Procambarus clarkii had remarkably similar neuropeptidomes. Although some neuropeptide precursors could not be assembled, in many cases individual reads pertaining to the missing precursors show unambiguously that these neuropeptides are present in these species. In other cases, the tissues that express those neuropeptides were not used in the construction of the cDNA libraries. One novel neuropeptide was identified: elongated PDH (pigment dispersing hormone), a variation on PDH that has a two-amino-acid insertion in its core sequence. Hyrg is another peptide that is ubiquitously present in decapods and is likely a novel neuropeptide precursor. Discussion. Many insect species have lost one or more neuropeptide genes, but apart from elongated PDH and hyrg all other decapod neuropeptides are present in at least some insect species, and allatotropin is the only insect neuropeptide missing from decapods. This strong similarity between insect and decapod neuropeptidomes makes it possible to predict the receptors for decapod neuropeptides

  9. Horton Law in Self-Similar Trees

    NASA Astrophysics Data System (ADS)

    Kovchegov, Yevgeniy; Zaliapin, Ilya

    2016-04-01

    Self-similarity of random trees is related to the operation of pruning. Pruning ℛ cuts the leaves and their parental edges and removes the resulting chains of degree-two nodes from a finite tree. A Horton-Strahler order of a vertex v and its parental edge is defined as the minimal number of prunings necessary to eliminate the subtree rooted at v. A branch is a group of neighboring vertices and edges of the same order. The Horton numbers 𝒩k[K] and 𝒩ij[K] are defined as the expected number of branches of order k, and the expected number of order-i branches that merged order-j branches, j > i, respectively, in a finite tree of order K. The Tokunaga coefficients are defined as Tij[K] = 𝒩ij[K]/𝒩j[K]. The pruning decreases the orders of tree vertices by unity. A rooted full binary tree is said to be mean-self-similar if its Tokunaga coefficients are invariant with respect to pruning: Tk := Ti,i+k[K]. We show that for self-similar trees, the condition limsupk→∞Tk1/k < ∞ is necessary and sufficient for the existence of the strong Horton law: 𝒩k[K]/𝒩1[K] → R1-k, as K →∞ for some R > 0 and every k ≥ 1. This work is a step toward providing rigorous foundations for the Horton law that, being omnipresent in natural branching systems, has escaped so far a formal explanation.

  10. Similarities between decapod and insect neuropeptidomes

    PubMed Central

    2016-01-01

    Background. Neuropeptides are important regulators of physiological processes and behavior. Although they tend to be generally well conserved, recent results using trancriptome sequencing on decapod crustaceans give the impression of significant differences between species, raising the question whether such differences are real or artefacts. Methods. The BLAST+ program was used to find short reads coding neuropeptides and neurohormons in publicly available short read archives. Such reads were then used to find similar reads in the same archives, and the DNA assembly program Trinity was employed to construct contigs encoding the neuropeptide precursors as completely as possible. Results. The seven decapod species analyzed in this fashion, the crabs Eriocheir sinensis, Carcinus maenas and Scylla paramamosain, the shrimp Litopenaeus vannamei, the lobster Homarus americanus, the fresh water prawn Macrobrachium rosenbergii and the crayfish Procambarus clarkii had remarkably similar neuropeptidomes. Although some neuropeptide precursors could not be assembled, in many cases individual reads pertaining to the missing precursors show unambiguously that these neuropeptides are present in these species. In other cases, the tissues that express those neuropeptides were not used in the construction of the cDNA libraries. One novel neuropeptide was identified: elongated PDH (pigment dispersing hormone), a variation on PDH that has a two-amino-acid insertion in its core sequence. Hyrg is another peptide that is ubiquitously present in decapods and is likely a novel neuropeptide precursor. Discussion. Many insect species have lost one or more neuropeptide genes, but apart from elongated PDH and hyrg all other decapod neuropeptides are present in at least some insect species, and allatotropin is the only insect neuropeptide missing from decapods. This strong similarity between insect and decapod neuropeptidomes makes it possible to predict the receptors for decapod neuropeptides

  11. Diverse precerebellar neurons share similar intrinsic excitability

    PubMed Central

    Kolkman, Kristine E.; McElvain, Lauren E.; du Lac, Sascha

    2011-01-01

    The cerebellum dedicates a majority of the brain’s neurons to processing a wide range of sensory, motor, and cognitive signals. Stereotyped circuitry within the cerebellar cortex suggests that similar computations are performed throughout the cerebellum, but little is known about whether diverse precerebellar neurons are specialized for the nature of the information they convey. In vivo recordings indicate that firing responses to sensory or motor stimuli vary dramatically across different precerebellar nuclei, but whether this reflects diverse synaptic inputs or differentially tuned intrinsic excitability has not been determined. We targeted whole-cell patch clamp recordings to neurons in 8 precerebellar nuclei which were retrogradely labeled from different regions of the cerebellum in mice. Intrinsic physiology was compared across neurons in the medial vestibular, external cuneate, lateral reticular, prepositus hypoglossi, supragenual, Roller/intercalatus, reticularis tegmenti pontis (NRTP), and pontine nuclei. Within the firing domain, precerebellar neurons were remarkably similar. Firing faithfully followed temporally modulated inputs, could be sustained at high rates, and was a linear function of input current over a wide range of inputs and firing rates. Pharmacological analyses revealed common expression of Kv3 currents, which were essential for a wide linear firing range, and of SK currents, which were essential for a wide linear input range. In contrast, membrane properties below spike threshold varied considerably within and across precerebellar nuclei, as evidenced by variability in postinhibitory rebound firing. Our findings indicate that diverse precerebellar neurons perfom similar scaling computations on their inputs but may be differentially tuned to synaptic inhibition. PMID:22090493

  12. Similar on the Inside (post-grinding)

    NASA Technical Reports Server (NTRS)

    2004-01-01

    This approximate true-color image taken by the panoramic camera on the Mars Exploration Rover Opportunity show the hole drilled into the rock called 'Pilbara,' which is located in the small crater dubbed 'Fram.' Spirit drilled into this rock with its rock abrasion tool. The rock appears to be dotted with the same 'blueberries,' or spherules, found at 'Eagle Crater.' After analyzing the hole with the rover's scientific instruments, scientists concluded that Pilbara has a similar chemical make-up, and thus watery past, to rocks studied at Eagle Crater. This image was taken with the panoramic camera's 480-, 530- and 600-nanometer filters.

  13. Similar on the Inside (pre-grinding)

    NASA Technical Reports Server (NTRS)

    2004-01-01

    This approximate true-color image taken by the panoramic camera on the Mars Exploration Rover Opportunity show the rock called 'Pilbara' located in the small crater dubbed 'Fram.' The rock appears to be dotted with the same 'blueberries,' or spherules, found at 'Eagle Crater.' Spirit drilled into this rock with its rock abrasion tool. After analyzing the hole with the rover's scientific instruments, scientists concluded that Pilbara has a similar chemical make-up, and thus watery past, to rocks studied at Eagle Crater. This image was taken with the panoramic camera's 480-, 530- and 600-nanometer filters.

  14. Desert ecosystems: similarities, characteristics, and health benefits.

    PubMed

    Carpio-Obeso, M P; Shorr, M; Valdez-Salas, B

    1999-01-01

    Salty bodies of water in desert zones are known worldwide. The Salton Sea in California, USA, and the Dead Sea between Israel and Jordan are located in arid areas at approximately the same latitude, which might explain some similarities. Both the Salton and Dead Seas have ecosystems consisting of a singular saline sea/hot desert interface. The Salton Sea, the largest inland body of water in California, is a saline lake in the Coachella and Imperial Valleys. The Imperial Valley is one of the 10 top agricultural areas in the United States. Several thermoelectric plants exploiting geothermal wells operate around the Salton Sea, and some areas comprise a National Wildlife Refuge. The Dead Sea (Sea of Salt in Hebrew), the lowest saline lake on earth, contains high concentrations of salts and is a reservoir of minerals with a unique evaporation regime. The Dead Sea salts are the raw materials for the production of several chemical and health products. Magnesium salts and sulfur-containing mud are used for treating human skin disorders, allergies, arthritis, and respiratory diseases. After visiting both zones, we recorded, analyzed, and compared the similarities and differences between the areas. Some differences were found in the geographic, orographic, hydraulic, and climatic properties, but the main difference is in the economic-industrial aspect. The characteristics and health aspects are described in this report.

  15. Similarity Rules for Scaling Solar Sail Systems

    NASA Technical Reports Server (NTRS)

    Canfield, Stephen L.; Peddieson, John; Garbe, Gregory

    2010-01-01

    Future science missions will require solar sails on the order of 200 square meters (or larger). However, ground demonstrations and flight demonstrations must be conducted at significantly smaller sizes, due to limitations of ground-based facilities and cost and availability of flight opportunities. For this reason, the ability to understand the process of scalability, as it applies to solar sail system models and test data, is crucial to the advancement of this technology. This paper will approach the problem of scaling in solar sail models by developing a set of scaling laws or similarity criteria that will provide constraints in the sail design process. These scaling laws establish functional relationships between design parameters of a prototype and model sail that are created at different geometric sizes. This work is applied to a specific solar sail configuration and results in three (four) similarity criteria for static (dynamic) sail models. Further, it is demonstrated that even in the context of unique sail material requirements and gravitational load of earth-bound experiments, it is possible to develop appropriate scaled sail experiments. In the longer term, these scaling laws can be used in the design of scaled experimental tests for solar sails and in analyzing the results from such tests.

  16. Exploiting Data Similarity to Reduce Memory Footprints

    SciTech Connect

    Biswas, S; de Supinski, B R; Schulz, M; Franklin, D; Sherwood, T; Chong, F T

    2011-01-28

    Memory size has long limited large-scale applications on high-performance computing (HPC) systems. Since compute nodes frequently do not have swap space, physical memory often limits problem sizes. Increasing core counts per chip and power density constraints, which limit the number of DIMMs per node, have exacerbated this problem. Further, DRAM constitutes a significant portion of overall HPC system cost. Therefore, instead of adding more DRAM to the nodes, mechanisms to manage memory usage more efficiently - preferably transparently - could increase effective DRAM capacity and thus the benefit of multicore nodes for HPC systems. MPI application processes often exhibit significant data similarity. These data regions occupy multiple physical locations across the individual rank processes within a multicore node and thus offer a potential savings in memory capacity. These regions, primarily residing in heap, are dynamic, which makes them difficult to manage statically. Our novel memory allocation library, SBLLmalloc, automatically identifies identical memory blocks and merges them into a single copy. SBLLmalloc does not require application or OS changes since we implement it as a user-level library. Overall, we demonstrate that SBLLmalloc reduces the memory footprint of a range of MPI applications by 32.03% on average and up to 60.87%. Further, SBLLmalloc supports problem sizes for IRS over 21.36% larger than using standard memory management techniques, thus significantly increasing effective system size. Similarly, SBLLmalloc requires 43.75% fewer nodes than standard memory management techniques to solve an AMG problem.

  17. Similarities between methamphetamine toxicity and proteasome inhibition.

    PubMed

    Fornai, F; Lenzi, P; Gesi, M; Ferrucci, M; Lazzeri, G; Capobianco, L; de Blasi, A; Battaglia, G; Nicoletti, F; Ruggieri, S; Paparelli, A

    2004-10-01

    The monoamine neurotoxin methamphetamine (METH) is commonly used as an experimental model for Parkinson's disease (PD). In fact, METH-induced striatal dopamine (DA) loss is accompanied by damage to striatal nerve endings arising from the substantia nigra. On the other hand, PD is characterized by neuronal inclusions within nigral DA neurons. These inclusions contain alpha-synuclein, ubiquitin, and various components of a metabolic pathway named the ubiquitin-proteasome (UP) system, while mutation of genes coding for various components of the UP system is responsible for inherited forms of PD. In this presentation we demonstrate for the first time the occurrence of neuronal inclusions in vivo in the nigrostriatal system of the mouse following administration of METH. We analyzed, in vivo and in vitro, the shape and the fine structure of these neuronal bodies by using transmission electron microscopy. Immunocytochemical investigation showed that these METH-induced cytosolic inclusions stain for ubiquitin, alpha-synuclein, and UP-related molecules, thus sharing similar components with Lewy bodies occurring in PD, with an emphasis on enzymes belonging to the UP system. In line with this, blockade of this multicatalytic pathway by the selective inhibitor epoxomycin produced cell inclusions with similar features. Moreover, using a multifaceted pharmacological approach, we could demonstrate the need for endogenous DA in order to form neuronal inclusions.

  18. Visualizing Similarity of Appearance by Arrangement of Cards.

    PubMed

    Nakatsuji, Nao; Ihara, Hisayasu; Seno, Takeharu; Ito, Hiroshi

    2016-01-01

    This study proposes a novel method to extract the configuration of the psychological space by directly measuring subjects' similarity rating without computational work. Although multidimensional scaling (MDS) is well-known as a conventional method for extracting the psychological space, the method requires many pairwise evaluations. The times taken for evaluations increase in proportion to the square of the number of objects in MDS. The proposed method asks subjects to arrange cards on a poster sheet according to the degree of similarity of the objects. To compare the performance of the proposed method with the conventional one, we developed similarity maps of typefaces through the proposed method and through non-metric MDS. We calculated the trace correlation coefficient among all combinations of the configuration for both methods to evaluate the degree of similarity in the obtained configurations. The threshold value of trace correlation coefficient for statistically discriminating similar configuration was decided based on random data. The ratio of the trace correlation coefficient exceeding the threshold value was 62.0% so that the configurations of the typefaces obtained by the proposed method closely resembled those obtained by non-metric MDS. The required duration for the proposed method was approximately one third of the non-metric MDS's duration. In addition, all distances between objects in all the data for both methods were calculated. The frequency for the short distance in the proposed method was lower than that of the non-metric MDS so that a relatively small difference was likely to be emphasized among objects in the configuration by the proposed method. The card arrangement method we here propose, thus serves as a easier and time-saving tool to obtain psychological structures in the fields related to similarity of appearance.

  19. Visualizing Similarity of Appearance by Arrangement of Cards

    PubMed Central

    Nakatsuji, Nao; Ihara, Hisayasu; Seno, Takeharu; Ito, Hiroshi

    2016-01-01

    This study proposes a novel method to extract the configuration of the psychological space by directly measuring subjects' similarity rating without computational work. Although multidimensional scaling (MDS) is well-known as a conventional method for extracting the psychological space, the method requires many pairwise evaluations. The times taken for evaluations increase in proportion to the square of the number of objects in MDS. The proposed method asks subjects to arrange cards on a poster sheet according to the degree of similarity of the objects. To compare the performance of the proposed method with the conventional one, we developed similarity maps of typefaces through the proposed method and through non-metric MDS. We calculated the trace correlation coefficient among all combinations of the configuration for both methods to evaluate the degree of similarity in the obtained configurations. The threshold value of trace correlation coefficient for statistically discriminating similar configuration was decided based on random data. The ratio of the trace correlation coefficient exceeding the threshold value was 62.0% so that the configurations of the typefaces obtained by the proposed method closely resembled those obtained by non-metric MDS. The required duration for the proposed method was approximately one third of the non-metric MDS's duration. In addition, all distances between objects in all the data for both methods were calculated. The frequency for the short distance in the proposed method was lower than that of the non-metric MDS so that a relatively small difference was likely to be emphasized among objects in the configuration by the proposed method. The card arrangement method we here propose, thus serves as a easier and time-saving tool to obtain psychological structures in the fields related to similarity of appearance. PMID:27242611

  20. Creating Birds of Similar Feathers: Leveraging Similarity to Improve Teacher-Student Relationships and Academic Achievement

    ERIC Educational Resources Information Center

    Gehlbach, Hunter; Brinkworth, Maureen E.; King, Aaron M.; Hsu, Laura M.; McIntyre, Joseph; Rogers, Todd

    2016-01-01

    When people perceive themselves as similar to others, greater liking and closer relationships typically result. In the first randomized field experiment that leverages actual similarities to improve real-world relationships, we examined the affiliations between 315 9th grade students and their 25 teachers. Students in the treatment condition…

  1. Similar Students, Different Choices: Who Uses a School Voucher in an Otherwise Similar Population of Students?

    ERIC Educational Resources Information Center

    Fleming, David J.; Cowen, Joshua M.; Witte, John F.; Wolf, Patrick J.

    2015-01-01

    We examine what factors predict why some parents enroll their children in voucher schools while other parents with similar types of children and from similar neighborhoods do not. Furthermore, we investigate how aware parents are of their educational options, where they get their information, and what school characteristics they deem the most…

  2. Mental additions and verbal-domain interference in children with developmental dyscalculia.

    PubMed

    Mammarella, Irene C; Caviola, Sara; Cornoldi, Cesare; Lucangeli, Daniela

    2013-09-01

    This study examined the involvement of verbal and visuo-spatial domains in solving addition problems with carrying in a sample of children diagnosed with developmental dyscalculia (DD) divided into two groups: (i) those with DD alone and (ii) those with DD and dyslexia. Age and stage matched typically developing (TD) children were also studied. The addition problems were presented horizontally or vertically and associated with verbal or visuo-spatial information. Study results showed that DD children's performance on mental calculation tasks was more impaired when they tackled horizontally presented addition problems compared to vertically presented ones that are associated to verbal domain involvement. The performance pattern in the two DD groups was found to be similar. The theoretical, clinical and educational implications of these findings are discussed.

  3. Ultra-accurate collaborative information filtering via directed user similarity

    NASA Astrophysics Data System (ADS)

    Guo, Q.; Song, W.-J.; Liu, J.-G.

    2014-07-01

    A key challenge of the collaborative filtering (CF) information filtering is how to obtain the reliable and accurate results with the help of peers' recommendation. Since the similarities from small-degree users to large-degree users would be larger than the ones in opposite direction, the large-degree users' selections are recommended extensively by the traditional second-order CF algorithms. By considering the users' similarity direction and the second-order correlations to depress the influence of mainstream preferences, we present the directed second-order CF (HDCF) algorithm specifically to address the challenge of accuracy and diversity of the CF algorithm. The numerical results for two benchmark data sets, MovieLens and Netflix, show that the accuracy of the new algorithm outperforms the state-of-the-art CF algorithms. Comparing with the CF algorithm based on random walks proposed by Liu et al. (Int. J. Mod. Phys. C, 20 (2009) 285) the average ranking score could reach 0.0767 and 0.0402, which is enhanced by 27.3% and 19.1% for MovieLens and Netflix, respectively. In addition, the diversity, precision and recall are also enhanced greatly. Without relying on any context-specific information, tuning the similarity direction of CF algorithms could obtain accurate and diverse recommendations. This work suggests that the user similarity direction is an important factor to improve the personalized recommendation performance.

  4. Chemical structure of odorants and perceptual similarity in ants.

    PubMed

    Bos, Nick; d'Ettorre, Patrizia; Guerrieri, Fernando J

    2013-09-01

    Animals are often immersed in a chemical world consisting of mixtures of many compounds rather than of single substances, and they constantly face the challenge of extracting relevant information out of the chemical landscape. To this purpose, the ability to discriminate among different stimuli with different valence is essential, but it is also important to be able to generalise, i.e. to treat different but similar stimuli as equivalent, as natural variation does not necessarily affect stimulus valence. Animals can thus extract regularities in their environment and make predictions, for instance about distribution of food resources. We studied perceptual similarity of different plant odours by conditioning individual carpenter ants to one odour, and subsequently testing their response to another, structurally different odour. We found that asymmetry in generalisation, where ants generalise from odour A to B, but not from B to A, is dependent on both chain length and functional group. By conditioning ants to a binary mixture, and testing their reaction to the individual components of the mixture, we show that overshadowing, where parts of a mixture are learned better than others, is rare. Additionally, generalisation is dependent not only on the structural similarity of odorants, but also on their functional value, which might play a crucial role. Our results provide insight into how ants make sense of the complex chemical world around them, for example in a foraging context, and provide a basis with which to investigate the neural mechanisms behind perceptual similarity.

  5. Fractal patterns of neural activity exist within the suprachiasmatic nucleus and require extrinsic network interactions.

    PubMed

    Hu, Kun; Meijer, Johanna H; Shea, Steven A; vanderLeest, Henk Tjebbe; Pittman-Polletta, Benjamin; Houben, Thijs; van Oosterhout, Floor; Deboer, Tom; Scheer, Frank A J L

    2012-01-01

    The mammalian central circadian pacemaker (the suprachiasmatic nucleus, SCN) contains thousands of neurons that are coupled through a complex network of interactions. In addition to the established role of the SCN in generating rhythms of ~24 hours in many physiological functions, the SCN was recently shown to be necessary for normal self-similar/fractal organization of motor activity and heart rate over a wide range of time scales--from minutes to 24 hours. To test whether the neural network within the SCN is sufficient to generate such fractal patterns, we studied multi-unit neural activity of in vivo and in vitro SCNs in rodents. In vivo SCN-neural activity exhibited fractal patterns that are virtually identical in mice and rats and are similar to those in motor activity at time scales from minutes up to 10 hours. In addition, these patterns remained unchanged when the main afferent signal to the SCN, namely light, was removed. However, the fractal patterns of SCN-neural activity are not autonomous within the SCN as these patterns completely broke down in the isolated in vitro SCN despite persistence of circadian rhythmicity. Thus, SCN-neural activity is fractal in the intact organism and these fractal patterns require network interactions between the SCN and extra-SCN nodes. Such a fractal control network could underlie the fractal regulation observed in many physiological functions that involve the SCN, including motor control and heart rate regulation.

  6. Three MADS-box genes similar to APETALA1 and FRUITFULL from silver birch (Betula pendula).

    PubMed

    Elo, Annakaisa; Lemmetyinen, Juha; Turunen, Marja-Leena; Tikka, Liisa; Sopanen, Tuomas

    2001-05-01

    Despite intensive research on genetic regulation of flower development there are still only a few studies on the early phases of this process in perennial plants like trees. The aim of this study has been to identify genes that regulate early stages of inflorescence development in silver birch (Betula pendula Roth) and to follow the expression of these genes during development of the unisexual birch inflorescences. Here we describe the cloning and characterization of 3 cDNAs representing MADS-box genes designated BpMADS3, BpMADS4 and BpMADS5, all belonging to the AP1/SQUA group of plant MADS-box genes. According to RNA blot analysis, all 3 genes are active during the development of both male and female inflorescences. However, differences in patterns of expression suggest that they play different roles. BpMADS3 is most similar in sequence to AP1 and SQUA, but it seems to have the highest expression at late developmental stages. BpMADS4 is most similar in sequence to the Arabidopsis gene FRUITFULL, but is expressed, in addition to developing inflorescences, in shoots and roots. BpMADS5 is also similar to FRUITFULL; its expression seems to be inflorescence-specific and continues during fruit development. Ectopic expression of either BpMADS3, BpMADS4 or BpMADS5 with the CaMV 35S promoter in tobacco results in extremely early flowering. All of these birch genes seem to act early during the transition to reproductive phase and might be involved in the determination of the identity of the inflorescence or flower meristem. They could apparently be used to accelerate flowering in various plant species.

  7. The Unknown Computer Viruses Detection Based on Similarity

    NASA Astrophysics Data System (ADS)

    Liu, Zhongda; Nakaya, Naoshi; Koui, Yuuji

    New computer viruses are continually being generated and they cause damage all over the world. In general, current anti-virus software detects viruses by matching a pattern based on the signature; thus, unknown viruses without any signature cannot be detected. Although there are some static analysis technologies that do not depend on signatures, virus writers often use code obfuscation techniques, which make it difficult to execute a code analysis. As is generally known, unknown viruses and known viruses share a common feature. In this paper we propose a new static analysis technology that can circumvent code obfuscation to extract the common feature and detect unknown viruses based on similarity. The results of evaluation experiments demonstrated that this technique is able to detect unknown viruses without false positives.

  8. Learning categories via rules and similarity: comparing adults and children.

    PubMed

    Rabi, Rahel; Miles, Sarah J; Minda, John Paul

    2015-03-01

    Two experiments explored the different strategies used by children and adults when learning new perceptual categories. Participants were asked to learn a set of categories for which both a single-feature rule and overall similarity would allow for perfect performance. Other rules allowed for suboptimal performance. Transfer stimuli (Experiments 1 and 2) and single features (Experiment 2) were presented after training to help determine how the categories were learned. In both experiments, we found that adults made significantly more optimal rule-based responses to the test stimuli than children. Children showed a variety of categorization styles, with a few relying on the optimal rules, many relying on suboptimal single-feature rules, and only a few relying on overall family resemblance. We interpret these results within a multiple systems framework, and we argue that children show the pattern they do because they lack the necessary cognitive resources to fully engage in hypothesis testing, rule selection, and verbally mediated category learning.

  9. Self-similarity and scaling in forest communities

    PubMed Central

    Simini, Filippo; Anfodillo, Tommaso; Carrer, Marco; Banavar, Jayanth R.; Maritan, Amos

    2010-01-01

    Ecological communities exhibit pervasive patterns and interrelationships between size, abundance, and the availability of resources. We use scaling ideas to develop a unified, model-independent framework for understanding the distribution of tree sizes, their energy use, and spatial distribution in tropical forests. We demonstrate that the scaling of the tree crown at the individual level drives the forest structure when resources are fully used. Our predictions match perfectly with the scaling behavior of an exactly solvable self-similar model of a forest and are in good accord with empirical data. The range, over which pure power law behavior is observed, depends on the available amount of resources. The scaling framework can be used for assessing the effects of natural and anthropogenic disturbances on ecosystem structure and functionality. PMID:20375286

  10. Popularity, similarity, and the network extraversion bias.

    PubMed

    Feiler, Daniel C; Kleinbaum, Adam M

    2015-05-01

    Using the emergent friendship network of an incoming cohort of students in an M.B.A. program, we examined the role of extraversion in shaping social networks. Extraversion has two important implications for the emergence of network ties: a popularity effect, in which extraverts accumulate more friends than introverts do, and a homophily effect, in which the more similar are two people's levels of extraversion, the more likely they are to become friends. These effects result in a systematic network extraversion bias, in which people's social networks will tend to be overpopulated with extraverts and underpopulated with introverts. Moreover, the most extraverted people have the greatest network extraversion bias, and the most introverted people have the least network extraversion bias. Our finding that social networks were systematically misrepresentative of the broader social environment raises questions about whether there is a societal bias toward believing other people are more extraverted than they actually are and whether introverts are better socially calibrated than extraverts.

  11. [Generics: similarities, bioequivalence but no conformity].

    PubMed

    Even-Adin, D; De Muylder, J A; Sternon, J

    2002-01-01

    The using of generic forms (GF) is presented as a potential source of budgetary "saving of money" in the field of pharmaceutical expenses. Not frequently prescribed in Belgium, they win a new interest thanks to the recent making use of the "reference repayment". Sale's authorization of GF is controlled by european rules, but some questions about their identity to original medications remain. Do similarities based only upon qualitative and quantitative composition in active molecules, pharmaceutical forms and biodisponibility give us all requested guaranties? Several cases of discordances can appear; the major elements of non conformity are the nature of excipients, notice's contents and the value of biodisponibility studies. However, in term of economy, in the drug market, development of GF appears to constitute an unavoidable phenomenon.

  12. Generalized entropies and the similarity of texts

    NASA Astrophysics Data System (ADS)

    Altmann, Eduardo G.; Dias, Laércio; Gerlach, Martin

    2017-01-01

    We show how generalized Gibbs–Shannon entropies can provide new insights on the statistical properties of texts. The universal distribution of word frequencies (Zipf’s law) implies that the generalized entropies, computed at the word level, are dominated by words in a specific range of frequencies. Here we show that this is the case not only for the generalized entropies but also for the generalized (Jensen–Shannon) divergences, used to compute the similarity between different texts. This finding allows us to identify the contribution of specific words (and word frequencies) for the different generalized entropies and also to estimate the size of the databases needed to obtain a reliable estimation of the divergences. We test our results in large databases of books (from the google n-gram database) and scientific papers (indexed by Web of Science).

  13. Self-similar Relativisitic Disks revisted

    NASA Astrophysics Data System (ADS)

    Cai, M. J.; Shu, F. H.

    2001-05-01

    We revisit the rotating self-similar disk first studied by Lynden-Bell and Pineault and extend it to include pressure. A two-parameter family of solutions is constructed numerically. These disks are parameterized by the constant linear rotation velocity v, and the isothermal sound speed γ 1/2. For sufficiently high velocities, an ergo region develops in the form of the exterior of a cone. For each value of γ , there is a maximum velocity vc above which there is no equilibrium solutions. For this solution the frame dragging is infinite and the ergo cone closes on the rotation axis. The null geodesic equations are also integrated numerically. Due to the infinite extend and mass of the system, all photon trajectories are focused towards the disk. The behavior of equatorial photons orbits is qualitatively the same as that of cold disks.

  14. Social values as arguments: similar is convincing

    PubMed Central

    Maio, Gregory R.; Hahn, Ulrike; Frost, John-Mark; Kuppens, Toon; Rehman, Nadia; Kamble, Shanmukh

    2014-01-01

    Politicians, philosophers, and rhetors engage in co-value argumentation: appealing to one value in order to support another value (e.g., “equality leads to freedom”). Across four experiments in the United Kingdom and India, we found that the psychological relatedness of values affects the persuasiveness of the arguments that bind them. Experiment 1 found that participants were more persuaded by arguments citing values that fulfilled similar motives than by arguments citing opposing values. Experiments 2 and 3 replicated this result using a wider variety of values, while finding that the effect is stronger among people higher in need for cognition and that the effect is mediated by the greater plausibility of co-value arguments that link motivationally compatible values. Experiment 4 extended the effect to real-world arguments taken from political propaganda and replicated the mediating effect of argument plausibility. The findings highlight the importance of value relatedness in argument persuasiveness. PMID:25147529

  15. Generalized Similarity for Accretion/Decretion Disks

    NASA Astrophysics Data System (ADS)

    Rafikov, Roman R.

    2016-10-01

    Decretion (or external) disks are gas disks freely expanding to large radii due to their internal stresses. They are expected to naturally arise in tidal disruption events, around Be stars, in mass-losing post-main-sequence binaries, as a result of supernova fallback, etc. Their evolution is theoretically understood in two regimes: when the central object does not exert torque on the disk (a standard assumption for conventional accretion disks) or when no mass inflow (or outflow) occurs at the disk center. However, many astrophysical objects—circumbinary disks, Be stars, neutron stars accreting in a propeller regime, etc.—feature non-zero torque simultaneously with the non-zero accretion (or ejection of mass) at the disk center. We provide a general description for the evolution of such disks (both linear and nonlinear) in the self-similar regime, to which the disk should asymptotically converge with time. We identify a similarity parameter λ, which is uniquely related to the degree, to which the central mass accretion is suppressed by the non-zero central torque. The known decretion disk solutions correspond to the two discrete values of λ, while our new solutions cover a continuum of its physically allowed values, corresponding to either accretion or mass ejection by the central object. A direct relationship between λ and central \\dot{M} and torque is also established. We describe the time evolution of the various disk characteristics for different λ, and show that the observable properties (spectrum and luminosity evolution) of the decretion disks, in general, are different from the standard accretion disks with no central torque.

  16. Statistical self-similarity of hotspot seamount volumes modeled as self-similar criticality

    USGS Publications Warehouse

    Tebbens, S.F.; Burroughs, S.M.; Barton, C.C.; Naar, D.F.

    2001-01-01

    The processes responsible for hotspot seamount formation are complex, yet the cumulative frequency-volume distribution of hotspot seamounts in the Easter Island/Salas y Gomez Chain (ESC) is found to be well-described by an upper-truncated power law. We develop a model for hotspot seamount formation where uniform energy input produces events initiated on a self-similar distribution of critical cells. We call this model Self-Similar Criticality (SSC). By allowing the spatial distribution of magma migration to be self-similar, the SSC model recreates the observed ESC seamount volume distribution. The SSC model may have broad applicability to other natural systems.

  17. [Macroscopic fungi from Sierra de Quila, Jalisco, Mexico: diversity and fungal similarity].

    PubMed

    Fierros, M L; Navarrete-Heredia, J L; Guzmán-Dávalos, L

    2000-12-01

    Diversity and similarity of macrofungi of Sierra de Quila, Jalisco, México were analized in three different kinds of vegetation. Fungal diversity in the area is high. The pine-oak and cloud forests, were more diverse in their community structure than the oak forest. Similarity among the three kinds of vegetation was low, there are few species share among them; pine-oak and cloud forests show higher affinity than oak forests. This pattern of similarity is a general condition for others regions with environmental conditions similar to Sierra de Quila.

  18. Analysis of spatial-temporal gene expression patterns reveals dynamics and regionalization in developing mouse brain.

    PubMed

    Chou, Shen-Ju; Wang, Chindi; Sintupisut, Nardnisa; Niou, Zhen-Xian; Lin, Chih-Hsu; Li, Ker-Chau; Yeang, Chen-Hsiang

    2016-01-20

    Allen Brain Atlas (ABA) provides a valuable resource of spatial/temporal gene expressions in mammalian brains. Despite rich information extracted from this database, current analyses suffer from several limitations. First, most studies are either gene-centric or region-centric, thus are inadequate to capture the superposition of multiple spatial-temporal patterns. Second, standard tools of expression analysis such as matrix factorization can capture those patterns but do not explicitly incorporate spatial dependency. To overcome those limitations, we proposed a computational method to detect recurrent patterns in the spatial-temporal gene expression data of developing mouse brains. We demonstrated that regional distinction in brain development could be revealed by localized gene expression patterns. The patterns expressed in the forebrain, medullary and pontomedullary, and basal ganglia are enriched with genes involved in forebrain development, locomotory behavior, and dopamine metabolism respectively. In addition, the timing of global gene expression patterns reflects the general trends of molecular events in mouse brain development. Furthermore, we validated functional implications of the inferred patterns by showing genes sharing similar spatial-temporal expression patterns with Lhx2 exhibited differential expression in the embryonic forebrains of Lhx2 mutant mice. These analysis outcomes confirm the utility of recurrent expression patterns in studying brain development.

  19. Asteroid clusters similar to asteroid pairs

    NASA Astrophysics Data System (ADS)

    Pravec, Petr; Vokrouhlicky, David; Fatka, Petr; Kusnirák, Peter; Hornoch, Kamil; Galád, Adrián

    2016-10-01

    We study five small, tight and young clusters of asteroids. They are placed around following largest (primary) bodies: (11842) Kap'bos, (14627) Emilkowalski, (16598) 1992 YC2, (21509) Lucascavin and (39991) 1998 HR37. Each cluster has 2-4 secondaries that are tightly clustered around the primary body, with distance in the 5-dimensional space of mean orbital elements mostly within 10 m/s, and always < 23 m/s. Backward orbital integrations indicate that they formed between 105 and 106 yr ago. In the P1-q space, where P1 is the primary's spin period and q = Σ Mj/M1 is the total secondary-to-primary mass ratio, the clusters lie in the same range as asteroid pairs formed by rotational fission. We have extended the model of a proto-system separation after rotational fission by Pravec et al. (2010) for application to systems with more than one secondary and found a perfect match for the five tight clusters. We find these clusters to be similar to asteroid pairs and we suggest that they are "extended pairs", having 2-4 escaped secondaries rather than just one secondary as in the case of an asteroid pair. We compare them to six young mini-families (1270) Datura, (2384) Schulhof, (3152) Jones, (6825) Irvine, (10321) Rampo and (20674) 1999 VT1. These mini-families have similar ages, but they have a higher number of members and/or they show a significantly larger spread in the mean orbital elements (dmean on an order of tens m/s) than the five tight clusters. In the P1-q space, all but one of the mini-families lie in the same range as asteroid pairs and the tight clusters; the exception is the mini-family of (3152) Jones which appears to be a collisional family. A possibility that the other five mini-families were also formed by rotational fission as we suggest for the tight clusters ("extended asteroid pairs") is being explored.Reference:Pravec, P., et al. Formation of asteroid pairs by rotational fission. Nature 466, 1085-1088.

  20. Clarifying the role of pattern separation in schizophrenia: the role of recognition and visual discrimination deficits.

    PubMed

    Martinelli, Cristina; Shergill, Sukhwinder S

    2015-08-01

    Patients with schizophrenia show marked memory deficits which have a negative impact on their functioning and life quality. Recent models suggest that such deficits might be attributable to defective pattern separation (PS), a hippocampal-based computation involved in the differentiation of overlapping stimuli and their mnemonic representations. One previous study on the topic concluded in favour of pattern separation impairments in the illness. However, this study did not clarify whether more elementary recognition and/or visual discrimination deficits could explain observed group differences. To address this limitation we investigated pattern separation in 22 schizophrenic patients and 24 healthy controls with the use of a task requiring individuals to classify stimuli as repetitions, novel or similar compared to a previous familiarisation phase. In addition, we employed a visual discrimination task involving perceptual similarity judgments on the same images. Results revealed impaired performance in the patient group; both on baseline measure of pattern separation as well as an index of pattern separation rigidity. However, further analyses demonstrated that such differences could be fully explained by recognition and visual discrimination deficits. Our findings suggest that pattern separation in schizophrenia is predicated on earlier recognition and visual discrimination problems. Furthermore, we demonstrate that future studies on pattern separation should include appropriate measures of recognition and visual discrimination performance for the correct interpretation of their findings.

  1. Magnus expansion and in-medium similarity renormalization group

    NASA Astrophysics Data System (ADS)

    Morris, T. D.; Parzuchowski, N. M.; Bogner, S. K.

    2015-09-01

    We present an improved variant of the in-medium similarity renormalization group (IM-SRG) based on the Magnus expansion. In the new formulation, one solves flow equations for the anti-Hermitian operator that, upon exponentiation, yields the unitary transformation of the IM-SRG. The resulting flow equations can be solved using a first-order Euler method without any loss of accuracy, resulting in substantial memory savings and modest computational speedups. Since one obtains the unitary transformation directly, the transformation of additional operators beyond the Hamiltonian can be accomplished with little additional cost, in sharp contrast to the standard formulation of the IM-SRG. Ground state calculations of the homogeneous electron gas (HEG) and 16O nucleus are used as test beds to illustrate the efficacy of the Magnus expansion.

  2. Song trait similarity in great tits varies with social structure.

    PubMed

    Snijders, Lysanne; van der Eijk, Jerine; van Rooij, Erica P; de Goede, Piet; van Oers, Kees; Naguib, Marc

    2015-01-01

    For many animals, long-range signalling is essential to maintain contact with conspecifics. In territorial species, individuals often have to balance signalling towards unfamiliar potential competitors (to solely broadcast territory ownership) with signalling towards familiar immediate neighbours (to also maintain so-called "dear enemy" relations). Hence, to understand how signals evolve due to these multilevel relationships, it is important to understand how general signal traits vary in relation to the overall social environment. For many territorial songbirds dawn is a key signalling period, with several neighbouring individuals singing simultaneously without immediate conflict. In this study we tested whether sharing a territory boundary, rather than spatial proximity, is related to similarity in dawn song traits between territorial great tits (Parus major) in a wild personality-typed population. We collected a large dataset of automatized dawn song recordings from 72 unique male great tits, during the fertile period of their mate, and compared specific song traits between neighbours and non-neighbours. We show here that both song rate and start time of dawn song were repeatable song traits. Moreover, neighbours were significantly more dissimilar in song rate compared to non-neighbours, while there was no effect of proximity on song rate similarity. Additionally, similarity in start time of dawn song was unrelated to sharing a territory boundary, but birds were significantly more similar in start time of dawn song when they were breeding in close proximity of each other. We suggest that the dissimilarity in dawn song rate between neighbours is either the result of neighbouring great tits actively avoiding similar song rates to possibly prevent interference, or a passive consequence of territory settlement preferences relative to the types of neighbours. Neighbourhood structuring is therefore likely to be a relevant selection pressure shaping variation in

  3. Durability to oxygen reactive ion etching enhanced by addition of synthesized bis(trimethylsilyl)phenyl-containing (meth)acrylates in ultraviolet nanoimprint lithography

    NASA Astrophysics Data System (ADS)

    Ito, Shunya; Sato, Hiroki; Tasaki, Yuhei; Watanuki, Kimihito; Nemoto, Nobukatsu; Nakagawa, Masaru

    2016-06-01

    We investigated the selection of bis(trimethylsilyl)phenyl-containing (meth)acrylates as additives to improve the durability to oxygen reactive ion etching (O2 RIE) of sub-50 nm imprint resist patterns suitable for bubble-defect-free UV nanoimprinting with a readily condensable gas. 2,5-Bis(2-acryloyloxyethoxy)-1,4-bis(trimethylsilyl)benzene, which has a diacrylate chemical structure similar to that of glycerol 1,3-diglycerolate diacrylate used as a base monomer, and 3-(2-methacryloyloxyethoxy)-1-(hydroxylethoxy)-2-propoxy-3,5-bis(trimethylsilyl)benzene, which has a hydroxy group similar to the base monomer, were synthesized taking into consideration the Ohnishi and ring parameters, and the oxidization of the trimethylsilyl moiety to inorganic species during O2 RIE. The addition of the latter liquid additive to the base monomer decreased etching rate owing to the good miscibility of the additive in the base monomer, while the addition of the former crystalline additive caused phase separation after UV nanoimprinting. The latter additive worked as a compatibilizer to the former additive, which is preferred for etching durability improvement. The coexistence of the additives enabled the fabrication of a 45 nm line-and-space resist pattern by UV nanoimprinting, and its residual layer could be removed by O2 RIE.

  4. DDE Transposases: Structural Similarity and Diversity

    PubMed Central

    Nesmelova, Irina V.; Hackett, Perry B.

    2010-01-01

    DNA transposons are mobile DNA elements that can move from one DNA molecule to another and thereby deliver genetic information into human chromosomes in order to confer a new function or replace a defective gene. This process requires a transposase enzyme. During transposition DD[E/D]-transposases undergo a series of conformational changes. We summarize the structural features of DD[E/D]-transposases for which three-dimensional structures are available and that relate to transposases, which are being developed for use in mammalian cells. Similar to other members of the polynucleotidyl transferase family, the catalytic domains of DD[E/D]-transposases share a common feature: an RNase H-like fold that draws three catalytically active residues, the DDE motif, into close proximity. Beyond this fold, the structures of catalytic domains vary considerably, and the DD[E/D]-transposases display marked structural diversity within their DNA-binding domains. Yet despite such structural variability, essentially the same end result is achieved. PMID:20615441

  5. Laplacian Eigenmaps From Sparse, Noisy Similarity Measurements

    NASA Astrophysics Data System (ADS)

    Levin, Keith; Lyzinski, Vince

    2017-04-01

    Manifold learning and dimensionality reduction techniques are ubiquitous in science and engineering, but can be computationally expensive procedures when applied to large data sets or when similarities are expensive to compute. To date, little work has been done to investigate the tradeoff between computational resources and the quality of learned representations. We present both theoretical and experimental explorations of this question. In particular, we consider Laplacian eigenmaps embeddings based on a kernel matrix, and explore how the embeddings behave when this kernel matrix is corrupted by occlusion and noise. Our main theoretical result shows that under modest noise and occlusion assumptions, we can (with high probability) recover a good approximation to the Laplacian eigenmaps embedding based on the uncorrupted kernel matrix. Our results also show how regularization can aid this approximation. Experimentally, we explore the effects of noise and occlusion on Laplacian eigenmaps embeddings of two real-world data sets, one from speech processing and one from neuroscience, as well as a synthetic data set.

  6. Pathogenesis of Malaria and Clinically Similar Conditions

    PubMed Central

    Clark, Ian A.; Alleva, Lisa M.; Mills, Alison C.; Cowden, William B.

    2004-01-01

    There is now wide acceptance of the concept that the similarity between many acute infectious diseases, be they viral, bacterial, or parasitic in origin, is caused by the overproduction of inflammatory cytokines initiated when the organism interacts with the innate immune system. This is also true of certain noninfectious states, such as the tissue injury syndromes. This review discusses the historical origins of these ideas, which began with tumor necrosis factor (TNF) and spread from their origins in malaria research to other fields. As well the more established proinflammatory mediators, such as TNF, interleukin-1, and lymphotoxin, the roles of nitric oxide and carbon monoxide, which are chiefly inhibitory, are discussed. The established and potential roles of two more recently recognized contributors, overactivity of the enzyme poly(ADP-ribose) polymerase 1 (PARP-1) and the escape of high-mobility-group box 1 (HMGB1) protein from its normal location into the circulation, are also put in context. The pathogenesis of the disease caused by falciparum malaria is then considered in the light of what has been learned about the roles of these mediators in these other diseases, as well as in malaria itself. PMID:15258091

  7. Mass versus molar doses, similarities and differences.

    PubMed

    Chmielewska, A; Lamparczyk, H

    2008-11-01

    Generally, they are two systems expressing the amounts of active substance in a given drug product, i.e. mass and molar dose. Currently, the dose system based on the mass is widely used in which doses are expressed in grams or milligrams. On the other hand, the molar dose system is in direct relation to the number of molecules. Hence, the objective of this work was to compare both systems in order to find their advantages and disadvantages. Active substances belonging to the groups of antibiotics, nootropic agents, beta-blockers, vitamins, GABA-analog, COX-2 inhibitors, calcium channel antagonists, benzodiazepine receptor agonists, lipid-modifying agents (fibrates), non-steroidal anti-inflammatory drugs (profens), estrogens, neuroleptics, analgesics and benzodiazepines were considered. Moreover, products containing two active substances were also taken into account. These are mixtures of hydrochlorothiazide with active substances influencing the renin-angiotensin system and combined oral contraceptives. For each active substance, belonging to the groups mentioned above molar doses were calculated from mass doses and molar mass. Hence, groups of drugs with a single active substance, drugs with similar pharmacological activities, pharmaceutical alternatives, and drugs with a single active ingredient manufactured in different doses were compared in order to find which dose system describes more adequately differences between and within the groups mentioned above. Comparisons were supported by a number of equations, which theoretically justify the data, and relationships derived from calculations.

  8. HMMER web server: interactive sequence similarity searching.

    PubMed

    Finn, Robert D; Clements, Jody; Eddy, Sean R

    2011-07-01

    HMMER is a software suite for protein sequence similarity searches using probabilistic methods. Previously, HMMER has mainly been available only as a computationally intensive UNIX command-line tool, restricting its use. Recent advances in the software, HMMER3, have resulted in a 100-fold speed gain relative to previous versions. It is now feasible to make efficient profile hidden Markov model (profile HMM) searches via the web. A HMMER web server (http://hmmer.janelia.org) has been designed and implemented such that most protein database searches return within a few seconds. Methods are available for searching either a single protein sequence, multiple protein sequence alignment or profile HMM against a target sequence database, and for searching a protein sequence against Pfam. The web server is designed to cater to a range of different user expertise and accepts batch uploading of multiple queries at once. All search methods are also available as RESTful web services, thereby allowing them to be readily integrated as remotely executed tasks in locally scripted workflows. We have focused on minimizing search times and the ability to rapidly display tabular results, regardless of the number of matches found, developing graphical summaries of the search results to provide quick, intuitive appraisement of them.

  9. Exploring similarities among many species distributions

    USGS Publications Warehouse

    Simmerman, Scott; Wang, Jingyuan; Osborne, James; Shook, Kimberly; Huang, Jian; Godsoe, William; Simons, Theodore R.

    2012-01-01

    Collecting species presence data and then building models to predict species distribution has been long practiced in the field of ecology for the purpose of improving our understanding of species relationships with each other and with the environment. Due to limitations of computing power as well as limited means of using modeling software on HPC facilities, past species distribution studies have been unable to fully explore diverse data sets. We build a system that can, for the first time to our knowledge, leverage HPC to support effective exploration of species similarities in distribution as well as their dependencies on common environmental conditions. Our system can also compute and reveal uncertainties in the modeling results enabling domain experts to make informed judgments about the data. Our work was motivated by and centered around data collection efforts within the Great Smoky Mountains National Park that date back to the 1940s. Our findings present new research opportunities in ecology and produce actionable field-work items for biodiversity management personnel to include in their planning of daily management activities.

  10. Perceptual tests of rhythmic similarity: II. Syllable rhythm.

    PubMed

    Kim, Jeesun; Davis, Chris; Cutler, Anne

    2008-01-01

    To segment continuous speech into its component words, listeners make use of language rhythm; because rhythm differs across languages, so do the segmentation procedures which listeners use. For each of stress-, syllable- and mora-based rhythmic structure, perceptual experiments have led to the discovery of corresponding segmentation procedures. In the case of mora-based rhythm, similar segmentation has been demonstrated in the otherwise unrelated languages Japanese and Telugu; segmentation based on syllable rhythm, however, has been previously demonstrated only for European languages from the Romance family. We here report two target detection experiments in which Korean listeners, presented with speech in Korean and in French, displayed patterns of segmentation like those previously observed in analogous experiments with French listeners. The Korean listeners' accuracy in detecting word-initial target fragments in either language was significantly higher when the fragments corresponded exactly to a syllable in the input than when the fragments were smaller or larger than a syllable. We conclude that Korean and French listeners can call on similar procedures for segmenting speech, and we further propose that perceptual tests of speech segmentation provide a valuable accompaniment to acoustic analyses for establishing languages' rhythmic class membership.

  11. Similarity of different lifting techniques in trunk muscular synergies.

    PubMed

    Mirakhorlo, Mojtaba; Azghani, Mahmood Reza

    2015-01-01

    Lifting is known to be a major reason for musculoskeletal injuries. In this way, lifting has a crucial effect on human musculoskeletal system and intensity of this impact depends slightly on the selection of techniques. Underlying mechanisms by which trunk muscles are executed during performing lifting are central to biomechanical study of lifting techniques. In the current study, the trunk muscular control mechanisms of lifting are investigated using the synergetic control analysis. Non-negative matrix factorization has been used to extract trunk muscles synergies from their activities - which are computed by a previously validated musculoskeletal model - during different lifting techniques aimed to investigate motor control strategies. Three lifting techniques are considered; stoop, squat and semi-squat. Three synergies account for variety among muscle activation of trunk muscles with related VAF (Variability Account For) of over 95%. Trunk muscle synergy weightings and related time-varying coefficients are calculated for each kind of lifting techniques considering three synergies. Paired correlation coefficients between muscle synergies are all greater than 0.91 (P < 0.05) suggesting that trunk muscle synergies are similar for examined techniques in spite of their kinematic diversity. This similarity can be a result of their common ultimate goal. The acquired results also elucidate the mechanisms of muscle activation patterns that can be exploited in future studies and ergonomic interventions.

  12. Chromatic induction and contrast masking: similar models, different goals?

    NASA Astrophysics Data System (ADS)

    Jiménez, Sandra; Otazu, Xavier; Laparra, Valero; Malo, Jesús

    2013-03-01

    Normalization of signals coming from linear sensors is an ubiquitous mechanism of neural adaptation.1 Local interaction between sensors tuned to a particular feature at certain spatial position and neighbor sensors explains a wide range of psychophysical facts including (1) masking of spatial patterns, (2) non-linearities of motion sensors, (3) adaptation of color perception, (4) brightness and chromatic induction, and (5) image quality assessment. Although the above models have formal and qualitative similarities, it does not necessarily mean that the mechanisms involved are pursuing the same statistical goal. For instance, in the case of chromatic mechanisms (disregarding spatial information), different parameters in the normalization give rise to optimal discrimination or adaptation, and different non-linearities may give rise to error minimization or component independence. In the case of spatial sensors (disregarding color information), a number of studies have pointed out the benefits of masking in statistical independence terms. However, such statistical analysis has not been performed for spatio-chromatic induction models where chromatic perception depends on spatial configuration. In this work we investigate whether successful spatio-chromatic induction models,6 increase component independence similarly as previously reported for masking models. Mutual information analysis suggests that seeking an efficient chromatic representation may explain the prevalence of induction effects in spatially simple images.

  13. Similarly shaped letters evoke similar colors in grapheme-color synesthesia.

    PubMed

    Brang, David; Rouw, Romke; Ramachandran, V S; Coulson, Seana

    2011-04-01

    Grapheme-color synesthesia is a neurological condition in which viewing numbers or letters (graphemes) results in the concurrent sensation of color. While the anatomical substrates underlying this experience are well understood, little research to date has investigated factors influencing the particular colors associated with particular graphemes or how synesthesia occurs developmentally. A recent suggestion of such an interaction has been proposed in the cascaded cross-tuning (CCT) model of synesthesia, which posits that in synesthetes connections between grapheme regions and color area V4 participate in a competitive activation process, with synesthetic colors arising during the component-stage of grapheme processing. This model more directly suggests that graphemes sharing similar component features (lines, curves, etc.) should accordingly activate more similar synesthetic colors. To test this proposal, we created and regressed synesthetic color-similarity matrices for each of 52 synesthetes against a letter-confusability matrix, an unbiased measure of visual similarity among graphemes. Results of synesthetes' grapheme-color correspondences indeed revealed that more similarly shaped graphemes corresponded with more similar synesthetic colors, with stronger effects observed in individuals with more intense synesthetic experiences (projector synesthetes). These results support the CCT model of synesthesia, implicate early perceptual mechanisms as driving factors in the elicitation of synesthetic hues, and further highlight the relationship between conceptual and perceptual factors in this phenomenon.

  14. Patterns of inner chorion structure in Anastrepha (Diptera: Tephritidae) eggs.

    PubMed

    Figueiredo, Julia V A; Perondini, André L P; Selivon, Denise

    2017-03-01

    The inner chorion structure of Anastrepha eggs from 16 species of various infrageneric taxonomic groups is described by scanning and transmission electron microscopy. The layers of the chorion, the outer egg membrane, are structurally similar. Furthermore, an additional trabecular layer (ATL) that exists in some species, together with other characteristics, facilitates the recognition of four patterns of chorion structuring: Pattern I, in which the ATL layer is absent, is found in Anastrepha amita, the Anastrepha fraterculus complex, Anastrepha obliqua, Anastrepha sororcula, Anastrepha suspensa and Anastrepha zenildae (fraterculus group), and Anastrepha bistrigata and Anastrepha striata (striata group); Pattern II in Anastrepha serpentina (serpentina group), Anastrepha grandis (grandis group) and Anastrepha pseudoparallela (pseudoparallela group), in which the ATL presents large open spaces with pillars; Pattern III, found in Anastrepha consobrina (pseudoparallela group), in which the ATL is composed of round cavities; and Pattern IV, found in Anastrepha alveata and Anastrepha pickeli (spatulata group), where the large ATL cavities are reticulated. Comparatively, the chorion structure in Anastrepha eggs is more complex than in eggs of other fruit flies, e.g., Bactrocera, Rhagoletis and Ceratitis.

  15. Effect of feed presentation on feeding patterns of dairy calves.

    PubMed

    Miller-Cushon, E K; Bergeron, R; Leslie, K E; Mason, G J; DeVries, T J

    2013-01-01

    The objectives of this study were to determine the effect of feed presentation on meal frequency and duration, as well as diurnal feeding patterns of dairy calves, and to assess any longer-term differences in feeding patterns resulting from previous experience. Twenty Holstein bull calves were exposed from wk 1 to 8 of life to 1 of 2 feed presentation treatments: concentrate and chopped grass hay (<2.5 cm) offered at a ratio of 7:3 as a mixture (MIX), or as separate components (COM). Feed was provided ad libitum. Calves received 8L/d of milk replacer (1.2 kg of dry matter), with the amount progressively reduced after 5 wk to facilitate weaning by the end of wk 7. At the beginning of wk 9, all calves received the MIX diet and remained on trial for an additional 3 wk. Feeding behavior was recorded from video for 4d during wk 6, 8, 9, and 11. In wk 6, calves fed MIX spent more time feeding than calves fed COM (56.7 vs. 46.8 min/d). In wk 8, calves fed MIX spent more time feeding (174.0 vs. 139.1 min/d) and had a lower rate of intake (11.5 vs. 14.7 g/min) compared with calves fed COM. Meal frequency was similar between treatments (12.2 meals/d). Diurnal feeding patterns in wk 8 were also affected by feed presentation, with calves fed MIX spending less time feeding at time of feed delivery and more time feeding throughout the rest of the daylight hours than calves fed COM. Diurnal feeding patterns of hay and concentrate in wk 8 differed for calves fed COM, with more time spent consuming hay at time of feed delivery and less time spent consuming hay throughout the rest of the day. Once calves previously fed COM were transitioned to the MIX diet in wk 9, meal frequency, meal duration, and diurnal feeding patterns were similar between treatments: both treatments spent similar amounts of time feeding (173.9 min/d) and had similar peaks in feeding activity at time of feed delivery, sunrise, and sunset. Provision of hay and concentrate to young calves as a mixed ration

  16. Neural similarity between encoding and retrieval is related to memory via hippocampal interactions.

    PubMed

    Ritchey, Maureen; Wing, Erik A; LaBar, Kevin S; Cabeza, Roberto

    2013-12-01

    A fundamental principle in memory research is that memory is a function of the similarity between encoding and retrieval operations. Consistent with this principle, many neurobiological models of declarative memory assume that memory traces are stored in cortical regions, and the hippocampus facilitates the reactivation of these traces during retrieval. The present investigation tested the novel prediction that encoding-retrieval similarity can be observed and related to memory at the level of individual items. Multivariate representational similarity analysis was applied to functional magnetic resonance imaging data collected during encoding and retrieval of emotional and neutral scenes. Memory success tracked fluctuations in encoding-retrieval similarity across frontal and posterior cortices. Importantly, memory effects in posterior regions reflected increased similarity between item-specific representations during successful recognition. Mediation analyses revealed that the hippocampus mediated the link between cortical similarity and memory success, providing crucial evidence for hippocampal-cortical interactions during retrieval. Finally, because emotional arousal is known to modulate both perceptual and memory processes, similarity effects were compared for emotional and neutral scenes. Emotional arousal was associated with enhanced similarity between encoding and retrieval patterns. These findings speak to the promise of pattern similarity measures for evaluating memory representations and hippocampal-cortical interactions.

  17. Learning semantic and visual similarity for endomicroscopy video retrieval.

    PubMed

    Andre, Barbara; Vercauteren, Tom; Buchner, Anna M; Wallace, Michael B; Ayache, Nicholas

    2012-06-01

    . In our resulting retrieval system, we decide to use visual signatures for perceived similarity learning and retrieval, and semantic signatures for the output of an additional information, expressed in the endoscopist own language, which provides a relevant semantic translation of the visual retrieval outputs.

  18. Mosaic, Self-Similarity Logic, and Biological Attraction principles

    PubMed Central

    Baluška, František; Barlow, Peter W; Guidolin, Diego

    2009-01-01

    From a structural standpoint, living organisms are organized like a nest of Russian matryoshka dolls, in which structures are buried within one another. From a temporal point of view, this type of organization is the result of a history comprised of a set of time backcloths which have accompanied the passage of living matter from its origins up to the present day. The aim of the present paper is to indicate a possible course of this ‘passage through time, and suggest how today’s complexity has been reached by living organisms. This investigation will employ three conceptual tools, namely the Mosaic, Self-Similarity Logic, and the Biological Attraction principles. Self-Similarity Logic indicates the self-consistency by which elements of a living system interact, irrespective of the spatiotemporal level under consideration. The term Mosaic indicates how, from the same set of elements assembled according to different patterns, it is possible to arrive at completely different constructions: hence, each system becomes endowed with different emergent properties. The Biological Attraction principle states that there is an inherent drive for association and merging of compatible elements at all levels of biological complexity. By analogy with the gravitation law in physics, biological attraction is based on the evidence that each living organism creates an attractive field around itself. This field acts as a sphere of influence that actively attracts similar fields of other biological systems, thereby modifying salient features of the interacting organisms. Three specific organizational levels of living matter, namely the molecular, cellular, and supracellular levels, have been considered in order to analyse and illustrate the interpretative as well as the predictive roles of each of these three explanatory principles. PMID:20195461

  19. Mapping of VSG similarities in Trypanosoma brucei.

    PubMed

    Weirather, Jason L; Wilson, Mary E; Donelson, John E

    2012-02-01

    The protozoan parasite Trypanosoma brucei switches its variant surface glycoprotein (VSG) to subvert its mammalian hosts' immune responses. The T. brucei genome contains as many as 1600 VSG genes (VSGs), but most are silent noncoding pseudogenes. Only one functional VSG, located in a telomere-linked expression site, is transcribed at a time. Silent VSGs are copied into a VSG expression site through gene conversion. Truncated gene conversion events can generate new mosaic VSGs with segments of sequence identity to other VSGs. To examine the VSG family sub-structure within which these events occur, we combined the available VSG sequences and annotations with scripted BLAST searches to map the relationships among VSGs in the T. brucei genome. Clusters of related VSGs were visualized in 2- and 3-dimensions for different N- and C-terminal regions. Five types of N-termini (N1-N5) were observed, within which gene recombinational events are likely to occur, often with fully-coding 'functional' or 'atypical'VSGs centrally located between more dissimilar VSGs. Members of types N1, N3 and N4 are most closely related in the middle of the N-terminal region, whereas type N2 members are more similar near the N-terminus. Some preference occurs in pairing between specific N- and C-terminal types. Statistical analyses indicated no overall tendency for more related VSGs to be located closer in the genome than less related VSGs, although exceptions were noted. Many potential mosaic gene formation events within each N-terminal type were identified, contrasted by only one possible mosaic gene formation between N-terminal types (N1 and N2). These data suggest that mosaic gene formation is a major contributor to the overall VSG diversity, even though gene recombinational events between members of different N-terminal types occur only rarely.

  20. Humans and Insects Decide in Similar Ways

    PubMed Central

    Louâpre, Philippe; van Alphen, Jacques J. M.; Pierre, Jean-Sébastien

    2010-01-01

    Behavioral ecologists assume that animals use a motivational mechanism for decisions such as action selection and time allocation, allowing the maximization of their fitness. They consider both the proximate and ultimate causes of behavior in order to understand this type of decision-making in animals. Experimental psychologists and neuroeconomists also study how agents make decisions but they consider the proximate causes of the behavior. In the case of patch-leaving, motivation-based decision-making remains simple speculation. In contrast to other animals, human beings can assess and evaluate their own motivation by an introspection process. It is then possible to study the declared motivation of humans during decision-making and discuss the mechanism used as well as its evolutionary significance. In this study, we combine both the proximate and ultimate causes of behavior for a better understanding of the human decision-making process. We show for the first time ever that human subjects use a motivational mechanism similar to small insects such as parasitoids [1] and bumblebees [2] to decide when to leave a patch. This result is relevant for behavioral ecologists as it supports the biological realism of this mechanism. Humans seem to use a motivational mechanism of decision making known to be adaptive to a heterogeneously distributed resource. As hypothesized by Hutchinson et al. [3] and Wilke and Todd [4], our results are consistent with the evolutionary shaping of decision making because hominoids were hunters and gatherers on food patches for more than two million years. We discuss the plausibility of a neural basis for the motivation mechanism highlighted here, bridging the gap between behavioral ecology and neuroeconomy. Thus, both the motivational mechanism observed here and the neuroeconomy findings are most likely adaptations that were selected for during ancestral times. PMID:21170378

  1. Similarities and differences among 105 members of the Int family of site-specific recombinases.

    PubMed Central

    Nunes-Düby, S E; Kwon, H J; Tirumalai, R S; Ellenberger, T; Landy, A

    1998-01-01

    Alignments of 105 site-specific recombinases belonging to the Int family of proteins identified extended areas of similarity and three types of structural differences. In addition to the previously recognized conservation of the tetrad R-H-R-Y, located in boxes I and II, several newly identified sequence patches include charged amino acids that are highly conserved and a specific pattern of buried residues contributing to the overall protein fold. With some notable exceptions, unconserved regions correspond to loops in the crystal structures of the catalytic domains of lambda Int (Int c170) and HP1 Int (HPC) and of the recombinases XerD and Cre. Two structured regions also harbor some pronounced differences. The first comprises beta-sheets 4 and 5, alpha-helix D and the adjacent loop connecting it to alpha-helix E: two Ints of phages infecting thermophilic bacteria are missing this region altogether; the crystal structures of HPC, XerD and Cre reveal a lack of beta-sheets 4 and 5; Cre displays two additional beta-sheets following alpha-helix D; five recombinases carry large insertions. The second involves the catalytic tyrosine and is seen in a comparison of the four crystal structures. The yeast recombinases can theoretically be fitted to the Int fold, but the overall differences, involving changes in spacing as well as in motif structure, are more substantial than seen in most other proteins. The phenotypes of mutations compiled from several proteins are correlated with the available structural information and structure-function relationships are discussed. In addition, a few prokaryotic and eukaryotic enzymes with partial homology with the Int family of recombinases may be distantly related, either through divergent or convergent evolution. These include a restriction enzyme and a subgroup of eukaryotic RNA helicases (D-E-A-D proteins). PMID:9421491

  2. Assessing the Development of Preschoolers' Mathematical Patterning

    ERIC Educational Resources Information Center

    Mitchelmore, Michael C.; Papic, Marina M.; Mulligan, Joanne T.

    2011-01-01

    The development of patterning strategies during the year prior to formal schooling was studied in 53 children from 2 similar preschools. One preschool implemented a 6-month intervention focusing on repeating and spatial patterns. Children from the intervention group demonstrated greater understanding of unit of repeat and spatial structuring, and…

  3. How Safe Are Color Additives?

    MedlinePlus

    ... Home For Consumers Consumer Updates How Safe are Color Additives? Share Tweet Linkedin Pin it More sharing ... Consumer Updates RSS Feed Download PDF (380 K) Color additives give the red tint to your fruit ...

  4. A general framework for regularized, similarity-based image restoration.

    PubMed

    Kheradmand, Amin; Milanfar, Peyman

    2014-12-01

    Any image can be represented as a function defined on a weighted graph, in which the underlying structure of the image is encoded in kernel similarity and associated Laplacian matrices. In this paper, we develop an iterative graph-based framework for image restoration based on a new definition of the normalized graph Laplacian. We propose a cost function, which consists of a new data fidelity term and regularization term derived from the specific definition of the normalized graph Laplacian. The normalizing coefficients used in the definition of the Laplacian and associated regularization term are obtained using fast symmetry preserving matrix balancing. This results in some desired spectral properties for the normalized Laplacian such as being symmetric, positive semidefinite, and returning zero vector when applied to a constant image. Our algorithm comprises of outer and inner iterations, where in each outer iteration, the similarity weights are recomputed using the previous estimate and the updated objective function is minimized using inner conjugate gradient iterations. This procedure improves the performance of the algorithm for image deblurring, where we do not have access to a good initial estimate of the underlying image. In addition, the specific form of the cost function allows us to render the spectral analysis for the solutions of the corresponding linear equations. In addition, the proposed approach is general in the sense that we have shown its effectiveness for different restoration problems, including deblurring, denoising, and sharpening. Experimental results verify the effectiveness of the proposed algorithm on both synthetic and real examples.

  5. Flow parsing and heading perception show similar dependence on quality and quantity of optic flow.

    PubMed

    Foulkes, Andrew J; Rushton, Simon K; Warren, Paul A

    2013-01-01

    Here we examine the relationship between the perception of heading and flow parsing. In a companion study we have investigated the pattern of dependence of human heading estimation on the quantity (amount of dots per frame) and quality (amount of directional noise) of motion information in an optic flow field. In the present study we investigated whether the flow parsing mechanism, which is thought to aid in the assessment of scene-relative object movement during observer movement, exhibits a similar pattern of dependence on these stimulus manipulations. Finding that the pattern of flow parsing effects was similar to that observed for heading thresholds would provide some evidence that these two complementary roles for optic flow processing are reliant on the same, or similar, neural computation. We found that the pattern of flow parsing effects observed does indeed display a striking similarity to the heading thresholds. As with judgements of heading, there is a critical value of around 25 dots per frame; below this value flow parsing effects rapidly deteriorate and above this value flow parsing effects are stable [see Warren et al. (1988) for similar results for heading]. Also, as with judgements of heading, when there were 50 or more dots there was a systematic effect of noise on the magnitude of the flow parsing effect. These results are discussed in the context of different possible schemes of flow processing to support both heading and flow parsing mechanisms.

  6. Detergent Additive for Lubricating Oils,

    DTIC Science & Technology

    The Russian patent pertains to a method of producing additives for lubricating oils . A method is known for producing an antiwear additive for... lubricating oils by processing phenols with phosphorus oxychloride, phosphoric acid esters are obtained. In order to give the additive detergent properties

  7. Expression of ABA Metabolism-Related Genes Suggests Similarities and Differences Between Seed Dormancy and Bud Dormancy of Peach (Prunus persica)

    PubMed Central

    Wang, Dongling; Gao, Zhenzhen; Du, Peiyong; Xiao, Wei; Tan, Qiuping; Chen, Xiude; Li, Ling; Gao, Dongsheng

    2016-01-01

    Dormancy inhibits seed and bud growth of perennial plants until the environmental conditions are optimal for survival. Previous studies indicated that certain co-regulation pathways exist in seed and bud dormancy. In our study, we found that seed and bud dormancy are similar to some extent but show different reactions to chemical treatments that induce breaking of dormancy. Whether the abscisic acid (ABA) regulatory networks are similar in dormant peach seeds and buds is not well known; however, ABA is generally believed to play a critical role in seed and bud dormancy. In peach, some genes putatively involved in ABA synthesis and catabolism were identified and their expression patterns were studied to learn more about ABA homeostasis and the possible crosstalk between bud dormancy and seed dormancy mechanisms. The analysis demonstrated that two 9-cis-epoxycarotenoid dioxygenase-encoding genes seem to be key in regulating ABA biosynthesis to induce seed and bud dormancy. Three CYP707As play an overlapping role in controlling ABA inactivation, resulting in dormancy-release. In addition, Transcript analysis of ABA metabolism-related genes was much similar demonstrated that ABA pathways was similar in the regulation of vegetative and flower bud dormancy, whereas, expression patterns of ABA metabolism-related genes were different in seed dormancy showed that ABA pathway maybe different in regulating seed dormancy in peach. PMID:26793222

  8. Expression of ABA Metabolism-Related Genes Suggests Similarities and Differences Between Seed Dormancy and Bud Dormancy of Peach (Prunus persica).

    PubMed

    Wang, Dongling; Gao, Zhenzhen; Du, Peiyong; Xiao, Wei; Tan, Qiuping; Chen, Xiude; Li, Ling; Gao, Dongsheng

    2015-01-01

    Dormancy inhibits seed and bud growth of perennial plants until the environmental conditions are optimal for survival. Previous studies indicated that certain co-regulation pathways exist in seed and bud dormancy. In our study, we found that seed and bud dormancy are similar to some extent but show different reactions to chemical treatments that induce breaking of dormancy. Whether the abscisic acid (ABA) regulatory networks are similar in dormant peach seeds and buds is not well known; however, ABA is generally believed to play a critical role in seed and bud dormancy. In peach, some genes putatively involved in ABA synthesis and catabolism were identified and their expression patterns were studied to learn more about ABA homeostasis and the possible crosstalk between bud dormancy and seed dormancy mechanisms. The analysis demonstrated that two 9-cis-epoxycarotenoid dioxygenase-encoding genes seem to be key in regulating ABA biosynthesis to induce seed and bud dormancy. Three CYP707As play an overlapping role in controlling ABA inactivation, resulting in dormancy-release. In addition, Transcript analysis of ABA metabolism-related genes was much similar demonstrated that ABA pathways was similar in the regulation of vegetative and flower bud dormancy, whereas, expression patterns of ABA metabolism-related genes were different in seed dormancy showed that ABA pathway maybe different in regulating seed dormancy in peach.

  9. Understanding human activity patterns based on space-time-semantics

    NASA Astrophysics Data System (ADS)

    Huang, Wei; Li, Songnian

    2016-11-01

    Understanding human activity patterns plays a key role in various applications in an urban environment, such as transportation planning and traffic forecasting, urban planning, public health and safety, and emergency response. Most existing studies in modeling human activity patterns mainly focus on spatiotemporal dimensions, which lacks consideration of underlying semantic context. In fact, what people do and discuss at some places, inferring what is happening at the places, cannot be simple neglected because it is the root of human mobility patterns. We believe that the geo-tagged semantic context, representing what individuals do and discuss at a place and a specific time, drives a formation of specific human activity pattern. In this paper, we aim to model human activity patterns not only based on space and time but also with consideration of associated semantics, and attempt to prove a hypothesis that similar mobility patterns may have different motivations. We develop a spatiotemporal-semantic model to quantitatively express human activity patterns based on topic models, leading to an analysis of space, time and semantics. A case study is conducted using Twitter data in Toronto based on our model. Through computing the similarities between users in terms of spatiotemporal pattern, semantic pattern and spatiotemporal-semantic pattern, we find that only a small number of users (2.72%) have very similar activity patterns, while the majority (87.14%) show different activity patterns (i.e., similar spatiotemporal patterns and different semantic patterns, similar semantic patterns and different spatiotemporal patterns, or different in both). The population of users that has very similar activity patterns is decreased by 56.41% after incorporating semantic information in the corresponding spatiotemporal patterns, which can quantitatively prove the hypothesis.

  10. Similar Associations of Tooth Microwear and Morphology Indicate Similar Diet across Marsupial and Placental Mammals

    PubMed Central

    Christensen, Hilary B.

    2014-01-01

    Low-magnification microwear techniques have been used effectively to infer diets within many unrelated mammalian orders, but the extent to which patterns are comparable among such different groups, including long extinct mammal lineages, is unknown. Microwear patterns between ecologically equivalent placental and marsupial mammals are found to be statistically indistinguishable, indicating that microwear can be used to infer diet across the mammals. Microwear data were compared to body size and molar shearing crest length in order to develop a system to distinguish the diet of mammals. Insectivores and carnivores were difficult to distinguish from herbivores using microwear alone, but combining microwear data with body size estimates and tooth morphology provides robust dietary inferences. This approach is a powerful tool for dietary assessment of fossils from extinct lineages and from museum specimens of living species where field study would be difficult owing to the animal’s behavior, habitat, or conservation status. PMID:25099537

  11. Similar associations of tooth microwear and morphology indicate similar diet across marsupial and placental mammals.

    PubMed

    Christensen, Hilary B

    2014-01-01

    Low-magnification microwear techniques have been used effectively to infer diets within many unrelated mammalian orders, but the extent to which patterns are comparable among such different groups, including long extinct mammal lineages, is unknown. Microwear patterns between ecologically equivalent placental and marsupial mammals are found to be statistically indistinguishable, indicating that microwear can be used to infer diet across the mammals. Microwear data were compared to body size and molar shearing crest length in order to develop a system to distinguish the diet of mammals. Insectivores and carnivores were difficult to distinguish from herbivores using microwear alone, but combining microwear data with body size estimates and tooth morphology provides robust dietary inferences. This approach is a powerful tool for dietary assessment of fossils from extinct lineages and from museum specimens of living species where field study would be difficult owing to the animal's behavior, habitat, or conservation status.

  12. Incorporation of additives into polymers

    DOEpatents

    McCleskey, T. Mark; Yates, Matthew Z.

    2003-07-29

    There has been invented a method for incorporating additives into polymers comprising: (a) forming an aqueous or alcohol-based colloidal system of the polymer; (b) emulsifying the colloidal system with a compressed fluid; and (c) contacting the colloidal polymer with the additive in the presence of the compressed fluid. The colloidal polymer can be contacted with the additive by having the additive in the compressed fluid used for emulsification or by adding the additive to the colloidal system before or after emulsification with the compressed fluid. The invention process can be carried out either as a batch process or as a continuous on-line process.

  13. Additive manufacturing of optical components

    NASA Astrophysics Data System (ADS)

    Heinrich, Andreas; Rank, Manuel; Maillard, Philippe; Suckow, Anne; Bauckhage, Yannick; Rößler, Patrick; Lang, Johannes; Shariff, Fatin; Pekrul, Sven

    2016-08-01

    The development of additive manufacturing methods has enlarged rapidly in recent years. Thereby, the work mainly focuses on the realization of mechanical components, but the additive manufacturing technology offers a high potential in the field of optics as well. Owing to new design possibilities, completely new solutions are possible. This article briefly reviews and compares the most important additive manufacturing methods for polymer optics. Additionally, it points out the characteristics of additive manufactured polymer optics. Thereby, surface quality is of crucial importance. In order to improve it, appropriate post-processing steps are necessary (e.g. robot polishing or coating), which will be discussed. An essential part of this paper deals with various additive manufactured optical components and their use, especially in optical systems for shape metrology (e.g. borehole sensor, tilt sensor, freeform surface sensor, fisheye lens). The examples should demonstrate the potentials and limitations of optical components produced by additive manufacturing.

  14. Computer Simulation of Diffraction Patterns.

    ERIC Educational Resources Information Center

    Dodd, N. A.

    1983-01-01

    Describes an Apple computer program (listing available from author) which simulates Fraunhofer and Fresnel diffraction using vector addition techniques (vector chaining) and allows user to experiment with different shaped multiple apertures. Graphics output include vector resultants, phase difference, diffraction patterns, and the Cornu spiral…

  15. Analysis Of Overlay Distortion Patterns

    NASA Astrophysics Data System (ADS)

    Armitage, John D.; Kirk, Joseph P.

    1988-01-01

    A comprehensive geometrical approach is presented for the least-squares analysis of overlay distortion patterns into useful, physically meaningful systematic distortion subpatterns and an essentially non-systematic residue. A scheme of generally useful distortion sub-patterns is presented in graphic and algorithmic form; some of these sub-patterns are additions to those already in widespread use. A graphic and geometric approach is emphasized rather than an algebraic or statistical approach, and an example illustrates the value in utilizing the pattern-detecting ability of the eye-brain system. The conditions are described under which different distortion sub-patterns may interact, possibly leading to misleading or erroneous conclusions about the types and amounts of different distortions present. Examples of typical interaction situations are given, and recommendations are made for analytic procedures to avoid misinterpretation. It is noted that the lower-order distortion patterns preserve straight-line linearity, but that higher-order distortion may result in straight lines becoming curved. The principle of least-squares analysis is outlined and a simple polynomial data-fitting example is used to illustrate the method. Algorithms are presented for least-squares distortion analysis of overlay patterns, and an APL2 program is given to show how this may easily be implemented on a digital computer. The appendix extends the treatment to cases where small-angle approximation is not permissible.

  16. The Evolution of Facultative Conformity Based on Similarity.

    PubMed

    Efferson, Charles; Lalive, Rafael; Cacault, Maria Paula; Kistler, Deborah

    2016-01-01

    Conformist social learning can have a pronounced impact on the cultural evolution of human societies, and it can shape both the genetic and cultural evolution of human social behavior more broadly. Conformist social learning is beneficial when the social learner and the demonstrators from whom she learns are similar in the sense that the same behavior is optimal for both. Otherwise, the social learner's optimum is likely to be rare among demonstrators, and conformity is costly. The trade-off between these two situations has figured prominently in the longstanding debate about the evolution of conformity, but the importance of the trade-off can depend critically on the flexibility of one's social learning strategy. We developed a gene-culture coevolutionary model that allows cognition to encode and process information about the similarity between naive learners and experienced demonstrators. Facultative social learning strategies that condition on perceived similarity evolve under certain circumstances. When this happens, facultative adjustments are often asymmetric. Asymmetric adjustments mean that the tendency to follow the majority when learners perceive demonstrators as similar is stronger than the tendency to follow the minority when learners perceive demonstrators as different. In an associated incentivized experiment, we found that social learners adjusted how they used social information based on perceived similarity, but adjustments were symmetric. The symmetry of adjustments completely eliminated the commonly assumed trade-off between cases in which learners and demonstrators share an optimum versus cases in which they do not. In a second experiment that maximized the potential for social learners to follow their preferred strategies, a few social learners exhibited an inclination to follow the majority. Most, however, did not respond systematically to social information. Additionally, in the complete absence of information about their similarity to

  17. The Evolution of Facultative Conformity Based on Similarity

    PubMed Central

    Efferson, Charles; Lalive, Rafael; Cacault, Maria Paula; Kistler, Deborah

    2016-01-01

    Conformist social learning can have a pronounced impact on the cultural evolution of human societies, and it can shape both the genetic and cultural evolution of human social behavior more broadly. Conformist social learning is beneficial when the social learner and the demonstrators from whom she learns are similar in the sense that the same behavior is optimal for both. Otherwise, the social learner’s optimum is likely to be rare among demonstrators, and conformity is costly. The trade-off between these two situations has figured prominently in the longstanding debate about the evolution of conformity, but the importance of the trade-off can depend critically on the flexibility of one’s social learning strategy. We developed a gene-culture coevolutionary model that allows cognition to encode and process information about the similarity between naive learners and experienced demonstrators. Facultative social learning strategies that condition on perceived similarity evolve under certain circumstances. When this happens, facultative adjustments are often asymmetric. Asymmetric adjustments mean that the tendency to follow the majority when learners perceive demonstrators as similar is stronger than the tendency to follow the minority when learners perceive demonstrators as different. In an associated incentivized experiment, we found that social learners adjusted how they used social information based on perceived similarity, but adjustments were symmetric. The symmetry of adjustments completely eliminated the commonly assumed trade-off between cases in which learners and demonstrators share an optimum versus cases in which they do not. In a second experiment that maximized the potential for social learners to follow their preferred strategies, a few social learners exhibited an inclination to follow the majority. Most, however, did not respond systematically to social information. Additionally, in the complete absence of information about their similarity to

  18. Towards drug repositioning: a unified computational framework for integrating multiple aspects of drug similarity and disease similarity.

    PubMed

    Zhang, Ping; Wang, Fei; Hu, Jianying

    2014-01-01

    In response to the high cost and high risk associated with traditional de novo drug discovery, investigation of potential additional uses for existing drugs, also known as drug repositioning, has attracted increasing attention from both the pharmaceutical industry and the research community. In this paper, we propose a unified computational framework, called DDR, to predict novel drug-disease associations. DDR formulates the task of hypothesis generation for drug repositioning as a constrained nonlinear optimization problem. It utilizes multiple drug similarity networks, multiple disease similarity networks, and known drug-disease associations to explore potential new associations among drugs and diseases with no known links. A large-scale study was conducted using 799 drugs against 719 diseases. Experimental results demonstrated the effectiveness of the approach. In addition, DDR ranked drug and disease information sources based on their contributions to the prediction, thus paving the way for prioritizing multiple data sources and building more reliable drug repositioning models. Particularly, some of our novel predictions of drug-disease associations were supported by clinical trials databases, showing that DDR could serve as a useful tool in drug discovery to efficiently identify potential novel uses for existing drugs.

  19. 76 FR 47210 - Notices of Filing of Petitions for Food Additives and Color Additives; Relocation in the Federal...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-08-04

    ... HUMAN SERVICES Food and Drug Administration Notices of Filing of Petitions for Food Additives and Color... petitions for food additives and color additives that are published in accordance with the Federal Food.... Similarly, section 721 of the FD&C Act (21 U.S.C. 379e) establishes a petition approval process for...

  20. Identifying patterns from one-rule-firing cellular automata.

    PubMed

    Shin, Jae Kyun

    2011-01-01

    A new firing scheme for cellular automata in which only one rule is fired at a time produces myriad patterns. In addition to geometric patterns, natural patterns such as flowers and snow crystals were also generated. This study proposes an efficient method identifying the patterns using a minimal number of digits. Complexity of the generated patterns is discussed in terms of the shapes and colors of the patterns.