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Sample records for morphologically indistinguishable diplomonads

  1. Identification of three morphologically indistinguishable Epicauta species (Coleoptera, Meloidae, Epicautini) through DNA barcodes and morphological comparisons.

    PubMed

    Liu, Shao-Pan; Pan, Zhao; Ren, Guo-Dong

    2016-04-14

    Three species that belong to the genus Epicauta (Coleopera: Meloidae), E. chinensis, E. dubia, and E. sibirica, appear morphologically indistinguishable. The present study aims to resolve the taxonomic status and the relationships among these three species. Identifying adult morphological characters among the three species were compared and illustrated and partial fragments of the mitochondrial gene (COI) for 77 samples, representing seven meloid species, were obtained and analyzed. Analyses of nucleotide composition, genetic distances and phylogenetics were performed. The results of the morphological studies and molecular analyses showed concordance, indicating that the three species are closely related and indistinguishable from one another. Consequently, two new synonyms are proposed: E. chinensis (Laporte, 1840) syn. n. = E. sibirica (Pallas, 1773) and E. dubia (Fabricius, 1781) syn. n. = E. sibirica (Pallas, 1773).

  2. Identification of genes suitable for DNA barcoding of morphologically indistinguishable Korean Halichondriidae sponges.

    PubMed

    Park, Mi-Hyun; Sim, Chung-Ja; Baek, Jina; Min, Gi-Sik

    2007-04-30

    The development of suitable genetic markers would be useful for defining species and delineating the species boundaries of morphologically indistinguishable sponges. In this study, genetic variation in the sequences of nuclear rDNA and the mitochondrial cytochrome c oxidase subunit 1 and 3 (CO1 and CO3) regions were compared in morphologically indistinguishable Korean Halichondriidae sponges in order to determine the most suitable species-specific molecular marker region. The maximal congeneric nucleotide divergences of Halichondriidae sponges in CO1 and CO3 are similar to those found among anthozoan cnidarians, but they are 2- to 8-fold lower than those found among genera of other triploblastic metazoans. Ribosomal internal transcribed spacer regions (ITS: ITS1 + ITS2) showed higher congeneric variation (17.28% in ITS1 and 10.29% in ITS2) than those of CO1 and CO3. Use of the guidelines for species thresholds suggested in the recent literature indicates that the mtDNA regions are not appropriate for use as species-specific DNA markers for the Halichondriidae sponges, whereas the rDNA ITS regions are suitable because ITS exhibits a low level of intraspecific variation and a relatively high level of interspecific variation. In addition, to test the reliability of the ITS regions for identifying Halichondriidae sponges by PCR, a species-specific multiplex PCR primer set was developed.

  3. Hydrogenosomes in the diplomonad Spironucleus salmonicida

    PubMed Central

    Jerlström-Hultqvist, Jon; Einarsson, Elin; Xu, Feifei; Hjort, Karin; Ek, Bo; Steinhauf, Daniel; Hultenby, Kjell; Bergquist, Jonas; Andersson, Jan O.; Svärd, Staffan G.

    2013-01-01

    Acquisition of the mitochondrion is a key event in the evolution of the eukaryotic cell, but diversification of the organelle has occurred during eukaryotic evolution. One example of such mitochondria-related organelles (MROs) are hydrogenosomes, which produce ATP by substrate-level phosphorylation with hydrogen as a byproduct. The diplomonad parasite Giardia intestinalis harbours mitosomes, another type of MRO. Here we identify MROs in the salmon parasite Spironucleus salmonicida with similar protein import and Fe–S cluster assembly machineries as in Giardia mitosomes. We find that hydrogen production is prevalent in the diplomonad genus Spironucleus, and that S. salmonicida MROs contain enzymes characteristic of hydrogenosomes. Evolutionary analyses of known hydrogenosomal components indicate their presence in the diplomonad ancestor, and subsequent loss in Giardia. Our results suggest that hydrogenosomes are metabolic adaptations predating the split between parabasalids and diplomonads, which is deeper than the split between animals and fungi in the eukaryotic tree. PMID:24042146

  4. Comparative biochemistry of Giardia, Hexamita and Spironucleus: Enigmatic diplomonads.

    PubMed

    Lloyd, David; Williams, Catrin F

    2014-10-01

    The diplomonad genera are here represented by three highly diverse species, both free-living (Hexamita inflata), and parasitic (Spironucleus vortens and Giardia intestinalis). All three are moderately aerotolerant flagellates, inhabiting environments where O2 tensions are low and fluctuating. Many diplomonads are opportunistic pathogens of avian, terrestrial and aquatic animals. Hexamitids inhabit deep waters and sediments of lakes and marine basins, S. vortens commonly infects the intestinal tract of ornamental fish, particularly of cichlids and cyprinids, and G. intestinalis, the upper intestinal tracts of humans as well as domestic and farm animals. Despite these very different habitats, their known physiological and biochemical characteristics are similar, but they do differ in significant respects as their lifestyles and life cycles demand. They have efficient O2 scavenging systems, and are highly effective at countering rapid O2 fluctuations, or clustering away from its source (except for G. intestinalis when attached to the jejunal villi). Their core metabolic pathways (glycolysis using pyrophosphate), incomplete tricarboxylic acid cycle (lacking α-ketoglutarate dehydrogenase), and amino acid metabolism (with an alternative energy-generating arginine dihydrolase pathway as a possibility in some cases), largely conform to those of other protists inhabiting low-O2 environments. Mitochondrial evolutionary reduction to give hydrogenosomes as seen in Spironucleus spp. has proceeded further to its minimal state in the mitosomes of G. intestinalis. Understanding of essential redox reactions and the maintentence of redox state, especially in the infective encysted stage of G. intestinalis provide increasing possibilities for parasite control. To this aim a plethora of new synthetic chemicals and natural products (especially those from garlic, Allium sativum) show promise as replacements for the highly effective (but potentially toxic to higher organisms) 5

  5. The resurrection of a species: Sarcocystis bovifelis Heydorn et al., 1975 is distinct from the current Sarcocystis hirsuta in cattle and morphologically indistinguishable from Sarcocystis sinensis in water buffaloes.

    PubMed

    Gjerde, Bjørn

    2016-01-01

    should again be used not only for the species originally described from cattle in Germany but also for morphologically indistinguishable taxa recently reported from cattle under the names S. sinensis and S. rommeli. Because of the morphological similarity between S. bovifelis and S. sinensis, it is likely that cats also act as definitive hosts for S. sinensis. The present paper also gives a thorough review of all research in the 1970s pertaining to S. bovifelis, including its development in cats and cattle; a review of reports of S. bovifelis-like sarcocysts in cattle, water buffaloes and other hosts; and a review of reports of the taxon currently named S. hirsuta in cattle. The usage of the name S. sinensis versus Sarcocystis dubeyi for the S. bovifelis-like taxon in water buffaloes is discussed, and the latter name is found to represent a nomen dubium since the original description concerned a mixture of a S. sinensis- and a Sarcocystis hominis-like species. Based on available transmission (TEM) and scanning electron microscopy (SEM) images, the three-dimensional configuration of the cyst wall protrusions of S. bovifelis/S. sinensis and the current S. hirsuta has been inferred and is described. The protrusions of S. bovifelis/S. sinensis are shaped like soft plastic tubes, having a cylindrical basal portion and a flattened distal portion, making them prone to fold over. The protrusions of the current S. hirsuta are thin, flattened and flexible rectangular structures (like a soft cover note book), which are attached to the cyst surface with a narrow stalk. The appearance of both types of protrusions in ultrathin sections viewed by TEM is highly dependent on how the sarcocysts and the protrusions themselves have been sectioned.

  6. Treatment of diplomonad intestinal parasites with magnesium sulphate at a commercial rainbow trout (Oncorhynchus mykiss) facility

    PubMed Central

    St-Hilaire, Sophie; Price, Derek; Taylor, Shawna; Groman, David

    2015-01-01

    Rainbow trout (average weight of 2 g) in fresh water experienced high mortality and were infected with a diplomonad intestinal parasite. Tanks of fish experienced an immediate reduction in mortality after an in-feed treatment with 3% Epsom salts for 2 d. Treatments had to be applied several times, but in each case there was a similar reduction in mortality. PMID:26246637

  7. Treatment of diplomonad intestinal parasites with magnesium sulphate at a commercial rainbow trout (Oncorhynchus mykiss) facility.

    PubMed

    St-Hilaire, Sophie; Price, Derek; Taylor, Shawna; Groman, David

    2015-08-01

    Rainbow trout (average weight of 2 g) in fresh water experienced high mortality and were infected with a diplomonad intestinal parasite. Tanks of fish experienced an immediate reduction in mortality after an in-feed treatment with 3% Epsom salts for 2 d. Treatments had to be applied several times, but in each case there was a similar reduction in mortality.

  8. Stable transformation of an episomal protein-tagging shuttle vector in the piscine diplomonad Spironucleus vortens

    PubMed Central

    Dawson, Scott C; Pham, Jonathan K; House, Susan A; Slawson, Elizabeth E; Cronembold, Daniela; Cande, W Zacheus

    2008-01-01

    Background Diplomonads are common free-living inhabitants of anoxic aquatic environments and are also found as intestinal commensals or parasites of a wide variety of animals. Spironucleus vortens is a putatively commensal diplomonad of angelfish that grows to high cell densities in axenic culture. Genomic sequencing of S. vortens is in progress, yet little information is available regarding molecular and cellular aspects of S. vortens biology beyond descriptive ultrastructural studies. To facilitate the development of S. vortens as an additional diplomonad experimental model, we have constructed and stably transformed an episomal plasmid containing an enhanced green fluorescent protein (GFP) tag, an AU1 epitope tag, and a tandem affinity purification (TAP) tag. This construct also contains selectable antibiotic resistance markers for both S. vortens and E. coli. Results Stable transformants of S. vortens grew relatively rapidly (within 7 days) after electroporation and were maintained under puromycin selection for over 6 months. We expressed the enhanced GFP variant, eGFP, under transcriptional control of the S. vortens histone H3 promoter, and visually confirmed diffuse GFP expression in over 50% of transformants. Next, we generated a histone H3::GFP fusion using the S. vortens conventional histone H3 gene and its native promoter. This construct was also highly expressed in the majority of S. vortens transformants, in which the H3::GFP fusion localized to the chromatin in both nuclei. Finally, we used fluorescence in situ hybridization (FISH) of the episomal plasmid to show that the transformed plasmid localized to only one nucleus/cell and was present at roughly 10–20 copies per nucleus. Because S. vortens grows to high densities in laboratory culture, it is a feasible diplomonad from which to purify native protein complexes. Thus, we also included a TAP tag in the plasmid constructs to permit future tagging and subsequent purification of protein complexes by

  9. The local indistinguishability of multipartite product states

    NASA Astrophysics Data System (ADS)

    Wang, Yan-Ling; Li, Mao-Sheng; Zheng, Zhu-Jun; Fei, Shao-Ming

    2017-01-01

    We study the perfectly local indistinguishability of multipartite product states. Firstly, we follow the method of Zhang et al. (Phys Rev A 93:012314, 2016) to give another more concise set of 2n-1 orthogonal product states in {mathbb {C}}^m⊗ {mathbb {C}}^n (4le mle n) which can not be distinguished by local operations and classical communication. Then we use the three-dimensional cubes to present some product states which give us an intuitive view on how to construct locally indistinguishable product states in tripartite quantum systems. At last, we give an explicit construction of locally indistinguishable orthogonal product states for general multipartite systems.

  10. Eight unique basal bodies in the multi-flagellated diplomonad Giardia lamblia.

    PubMed

    McInally, Shane G; Dawson, Scott C

    2016-01-01

    Giardia lamblia is an intestinal parasitic protist that causes significant acute and chronic diarrheal disease worldwide. Giardia belongs to the diplomonads, a group of protists in the supergroup Excavata. Diplomonads are characterized by eight motile flagella organized into four bilaterally symmetric pairs. Each of the eight Giardia axonemes has a long cytoplasmic region that extends from the centrally located basal body before exiting the cell body as a membrane-bound flagellum. Each basal body is thus unique in its cytological position and its association with different cytoskeletal features, including the ventral disc, axonemes, and extra-axonemal structures. Inheritance of these unique and complex cytoskeletal elements is maintained through basal body migration, duplication, maturation, and their subsequent association with specific spindle poles during cell division. Due to the complex composition and inheritance of specific basal bodies and their associated structures, Giardia may require novel basal body-associated proteins. Thus, protists such as Giardia may represent an undiscovered source of novel basal body-associated proteins. The development of new tools that make Giardia genetically tractable will enable the composition, structure, and function of the eight basal bodies to be more thoroughly explored.

  11. On optimal currents of indistinguishable particles

    NASA Astrophysics Data System (ADS)

    Walschaers, Mattia; Buchleitner, Andreas; Fannes, Mark

    2017-02-01

    We establish a mathematically rigorous, general and quantitative framework to describe currents of non- (or weakly) interacting, indistinguishable particles driven far from equilibrium. We derive tight upper and lower bounds for the achievable fermionic and bosonic steady state current, respectively, which can serve as benchmarks for special cases of interacting many-particle dynamics. For fermionic currents, we identify a symmetry-induced enhancement mechanism in parameter regimes where the coupling between system and reservoirs is weak. This mechanism is broadly applicable provided the inter-particle interaction strength is small as compared to typical exchange interactions.

  12. Transcriptomic analysis of diplomonad parasites reveals a trans-spliced intron in a helicase gene in Giardia

    PubMed Central

    2017-01-01

    Background The mechanisms by which DNA sequences are expressed is the central preoccupation of molecular genetics. Recently, ourselves and others reported that in the diplomonad protist Giardia lamblia, the coding regions of several mRNAs are produced by ligation of independent RNA species expressed from distinct genomic loci. Such trans-splicing of introns was found to affect nearly as many genes in this organism as does classical cis-splicing of introns. These findings raised questions about the incidence of intron trans-splicing both across the G. lambliatranscriptome and across diplomonad diversity in general, however a dearth of transcriptomic data at the time prohibited systematic study of these questions. Methods I leverage newly available transcriptomic data from G. lamblia and the related diplomonad Spironucleus salmonicidato search for trans-spliced introns. My computational pipeline recovers all four previously reported trans-spliced introns in G. lamblia, suggesting good sensitivity. Results Scrutiny of thousands of potential cases revealed only a single additional trans-spliced intron in G. lamblia, in the p68 helicase gene, and no cases in S. salmonicida. The p68 intron differs from the previously reported trans-spliced introns in its high degree of streamlining: the core features of G. lamblia trans-spliced introns are closely packed together, revealing striking economy in the implementation of a seemingly inherently uneconomical molecular mechanism. Discussion These results serve to circumscribe the role of trans-splicing in diplomonads both in terms of the number of genes effected and taxonomically. Future work should focus on the molecular mechanisms, evolutionary origins and phenotypic implications of this intriguing phenomenon. PMID:28090405

  13. Theories of Newtonian gravity and empirical indistinguishability

    NASA Astrophysics Data System (ADS)

    Bain, Jonathan

    2004-09-01

    In this essay, I examine the curved spacetime formulation of Newtonian gravity known as Newton-Cartan gravity and compare it with flat spacetime formulations. Two versions of Newton-Cartan gravity can be identified in the physics literature-a "weak" version and a "strong" version. The strong version has a constrained Hamiltonian formulation and consequently a well-defined gauge structure, whereas the weak version does not (with some qualifications). Moreover, the strong version is best compared with the structure of what Earman (World enough and spacetime. Cambridge: MIT Press) has dubbed Maxwellian spacetime. This suggests that there are also two versions of Newtonian gravity in flat spacetime-a "weak" version in Maxwellian spacetime, and a "strong" version in Neo-Newtonian spacetime. I conclude by indicating how these alternative formulations of Newtonian gravity impact the notion of empirical indistinguishability and the debate over scientific realism.

  14. LOCC indistinguishable orthogonal product quantum states

    PubMed Central

    Zhang, Xiaoqian; Tan, Xiaoqing; Weng, Jian; Li, Yongjun

    2016-01-01

    We construct two families of orthogonal product quantum states that cannot be exactly distinguished by local operation and classical communication (LOCC) in the quantum system of 2k+i ⊗ 2l+j (i, j ∈ {0, 1} and i ≥ j ) and 3k+i ⊗ 3l+j (i, j ∈ {0, 1, 2}). And we also give the tiling structure of these two families of quantum product states where the quantum states are unextendible in the first family but are extendible in the second family. Our construction in the quantum system of 3k+i ⊗ 3l+j is more generalized than the other construction such as Wang et al.’s construction and Zhang et al.’s construction, because it contains the quantum system of not only 2k ⊗ 2l and 2k+1 ⊗ 2l but also 2k ⊗ 2l+1 and 2k+1 ⊗ 2l+1. We calculate the non-commutativity to quantify the quantumness of a quantum ensemble for judging the local indistinguishability. We give a general method to judge the indistinguishability of orthogonal product states for our two constructions in this paper. We also extend the dimension of the quantum system of 2k ⊗ 2l in Wang et al.’s paper. Our work is a necessary complement to understand the phenomenon of quantum nonlocality without entanglement. PMID:27377310

  15. Quantifying entanglement of overlapping indistinguishable particles

    NASA Astrophysics Data System (ADS)

    Gittings, Joseph R.

    This thesis develops the quantitative study of quantum entanglement in systems of identical particles. Understanding this topic is essential for the construction of quantum information processing devices involving identical particles. A brief overview of necessary concepts and methods, such as the density matrix, the entanglement in pure and mixed states of distinguishable particles, and some common applications of entanglement is given in the introduction. Some competing methods of calculating the entanglement in bipartite pure states of indistinguishable particles are examined. It is shown that only the 'site entropy' measure introduced by Zanardi satisfies all the criteria for a correct entanglement measure. A teleportation protocol which utilizes all the entanglement carried (in both the spin and space degrees of freedom) in a doubly- occupied molecular bonding orbital is presented. The output from an interferometer in a thought experiment described by Omar et al. is studied as an example to see whether entanglement can be separated into space-only, spin-only, and space-spin components. A similar exercise is performed for a doubly-occupied molecular bonding orbital. The relationship between these results and the application of superselection rules (SSRs) to the quantification of useful entanglement is discussed. A numerical method for estimating the entanglement of formation of a mixed state of arbitrary dimension by a conjugate gradient algorithm is described. The results of applying an implementation of the algorithm to both random and isotropic states of 2 qutrits (i.e. two three-dimensional systems) is described. Existing work on calculating entanglement between two sites in various spin systems is outlined. New methods for calculating the entanglement between two sites in various types of degenerate quantum gas - a Fermi gas, a Bose condensate, and a BCS superconductor - are described. The results of numerical studies of the entanglement in a normal metal

  16. Locally indistinguishable orthogonal product bases in arbitrary bipartite quantum system

    PubMed Central

    Xu, Guang-Bao; Yang, Ying-Hui; Wen, Qiao-Yan; Qin, Su-Juan; Gao, Fei

    2016-01-01

    As we know, unextendible product basis (UPB) is an incomplete basis whose members cannot be perfectly distinguished by local operations and classical communication. However, very little is known about those incomplete and locally indistinguishable product bases that are not UPBs. In this paper, we first construct a series of orthogonal product bases that are completable but not locally distinguishable in a general m ⊗ n (m ≥ 3 and n ≥ 3) quantum system. In particular, we give so far the smallest number of locally indistinguishable states of a completable orthogonal product basis in arbitrary quantum systems. Furthermore, we construct a series of small and locally indistinguishable orthogonal product bases in m ⊗ n (m ≥ 3 and n ≥ 3). All the results lead to a better understanding of the structures of locally indistinguishable product bases in arbitrary bipartite quantum system. PMID:27503634

  17. Non-commutativity and Local Indistinguishability of Quantum States

    PubMed Central

    Ma, Teng; Zhao, Ming-Jing; Wang, Yao-Kun; Fei, Shao-Ming

    2014-01-01

    We study the local indistinguishability problem of quantum states. By introducing an easily calculated quantity, non-commutativity, we present an criterion which is both necessary and sufficient for the local indistinguishability of a complete set of pure orthogonal product states. A constructive distinguishing procedure to obtain the concrete local measurements and classical communications is given. The non-commutativity of ensembles can be also used to characterize the quantumness for classical-quantum or quantum-classical correlated states. PMID:25208830

  18. Coherence and indistinguishability of single electrons emitted by independent sources.

    PubMed

    Bocquillon, E; Freulon, V; Berroir, J-M; Degiovanni, P; Plaçais, B; Cavanna, A; Jin, Y; Fève, G

    2013-03-01

    The on-demand emission of coherent and indistinguishable electrons by independent synchronized sources is a challenging task of quantum electronics, in particular regarding its application for quantum information processing. Using two independent on-demand electron sources, we triggered the emission of two single-electron wave packets at different inputs of an electronic beam splitter. Whereas classical particles would be randomly partitioned by the splitter, we observed two-particle interference resulting from quantum exchange. Both electrons, emitted in indistinguishable wave packets with synchronized arrival time on the splitter, exited in different outputs as recorded by the low-frequency current noise. The demonstration of two-electron interference provides the possibility of manipulating coherent and indistinguishable single-electron wave packets in quantum conductors.

  19. A mitochondrial-like chaperonin 60 gene in Giardia lamblia: evidence that diplomonads once harbored an endosymbiont related to the progenitor of mitochondria.

    PubMed

    Roger, A J; Svärd, S G; Tovar, J; Clark, C G; Smith, M W; Gillin, F D; Sogin, M L

    1998-01-06

    Diplomonads, parabasalids, as represented by trichomonads, and microsporidia are three protist lineages lacking mitochondria that branch earlier than all other eukaryotes in small subunit rRNA and elongation factor phylogenies. The absence of mitochondria and plastids in these organisms suggested that they diverged before the origin of these organelles. However, recent discoveries of mitochondrial-like heat shock protein 70 and/or chaperonin 60 (cpn60) genes in trichomonads and microsporidia imply that the ancestors of these two groups once harbored mitochondria or their endosymbiotic progenitors. In this report, we describe a mitochondrial-like cpn60 homolog from the diplomonad parasite Giardia lamblia. Northern and Western blots reveal that the expression of cpn60 is independent of cellular stress and, except during excystation, occurs throughout the G. lamblia life cycle. Phylogenetic analyses position the G. lamblia cpn60 in a clade that includes mitochondrial and hydrogenosomal cpn60 proteins. The most parsimonious interpretation of these data is that the cpn60 gene was transferred from the endosymbiotic ancestors of mitochondria to the nucleus early in eukaryotic evolution, before the divergence of the diplomonads and trichomonads from other extant eukaryotic lineages. A more complicated explanation requires that these genes originated from distinct alpha-proteobacterial endosymbioses that formed transiently within these protist lineages.

  20. The false dichotomy: a refutation of the Neandertal indistinguishability claim.

    PubMed

    Wynn, Thomas; Overmann, Karenleigh; Coolidge, Frederick

    2016-06-20

    In the debate about the demise of the Neandertal, several scholars have claimed that humanity's nearest relatives were indistinguishable archaeologically, and thus behaviorally and cognitively, from contemporaneous Homo sapiens. They suggest that to hold otherwise is to characterize Neandertals as inferior to H. sapiens, a false dichotomy that excludes the possibility that the two human types simply differed in ways visible to natural selection, including their cognition. Support of the Neandertal indistinguishability claim requires ignoring the cranial differences between the two human types, which have implications for cognition and behavior. Further, support of the claim requires minimizing asymmetries in the quantity and degree of behavioral differences as attested by the archaeological record. The present paper reviews the evidence for cognitive and archaeological differences between the two human types in support of the excluded middle position.

  1. Broadband indistinguishability from bright parametric downconversion in a semiconductor waveguide

    NASA Astrophysics Data System (ADS)

    Günthner, T.; Pressl, B.; Laiho, K.; Geßler, J.; Höfling, S.; Kamp, M.; Schneider, C.; Weihs, G.

    2015-12-01

    Parametric downconversion (PDC) in semiconductor Bragg-reflection waveguides (BRW) is routinely exploited for photon-pair generation in the telecommunication range. Contrary to many conventional PDC sources, BRWs offer possibilities to create spectrally broadband but nevertheless indistinguishable photon pairs in orthogonal polarizations that simultaneously incorporate high frequency entanglement. We explore the characteristics of co-propagating twin beams created in a type-II ridge BRW. Our PDC source is bright and efficient, serving as a benchmark of its performance and justifies its exploitation for further use in quantum photonics. We then examine the coalescence of the twin beams and investigate the effect of their inevitable multi-photon contributions on the observed photon bunching. Our results show that BRWs have a great potential for producing broadband indistinguishable photon pairs as well as multi-photon states.

  2. Optimal excitation conditions for indistinguishable photons from quantum dots

    NASA Astrophysics Data System (ADS)

    Huber, Tobias; Predojević, Ana; Föger, Daniel; Solomon, Glenn; Weihs, Gregor

    2015-12-01

    In this paper, we present a detailed, all optical study of the influence of different excitation schemes on the indistinguishability of single photons from a single InAs quantum dot. For this study, we measure the Hong-Ou-Mandel interference of consecutive photons from the spontaneous emission of an InAs quantum dot state under various excitation schemes and different excitation conditions and give a comparison.

  3. Active temporal multiplexing of indistinguishable heralded single photons

    PubMed Central

    Xiong, C.; Zhang, X.; Liu, Z.; Collins, M. J.; Mahendra, A.; Helt, L. G.; Steel, M. J.; Choi, D. -Y.; Chae, C. J.; Leong, P. H. W.; Eggleton, B. J.

    2016-01-01

    It is a fundamental challenge in quantum optics to deterministically generate indistinguishable single photons through non-deterministic nonlinear optical processes, due to the intrinsic coupling of single- and multi-photon-generation probabilities in these processes. Actively multiplexing photons generated in many temporal modes can decouple these probabilities, but key issues are to minimize resource requirements to allow scalability, and to ensure indistinguishability of the generated photons. Here we demonstrate the multiplexing of photons from four temporal modes solely using fibre-integrated optics and off-the-shelf electronic components. We show a 100% enhancement to the single-photon output probability without introducing additional multi-photon noise. Photon indistinguishability is confirmed by a fourfold Hong–Ou–Mandel quantum interference with a 91±16% visibility after subtracting multi-photon noise due to high pump power. Our demonstration paves the way for scalable multiplexing of many non-deterministic photon sources to a single near-deterministic source, which will be of benefit to future quantum photonic technologies. PMID:26996317

  4. Active temporal multiplexing of indistinguishable heralded single photons

    NASA Astrophysics Data System (ADS)

    Xiong, C.; Zhang, X.; Liu, Z.; Collins, M. J.; Mahendra, A.; Helt, L. G.; Steel, M. J.; Choi, D.-Y.; Chae, C. J.; Leong, P. H. W.; Eggleton, B. J.

    2016-03-01

    It is a fundamental challenge in quantum optics to deterministically generate indistinguishable single photons through non-deterministic nonlinear optical processes, due to the intrinsic coupling of single- and multi-photon-generation probabilities in these processes. Actively multiplexing photons generated in many temporal modes can decouple these probabilities, but key issues are to minimize resource requirements to allow scalability, and to ensure indistinguishability of the generated photons. Here we demonstrate the multiplexing of photons from four temporal modes solely using fibre-integrated optics and off-the-shelf electronic components. We show a 100% enhancement to the single-photon output probability without introducing additional multi-photon noise. Photon indistinguishability is confirmed by a fourfold Hong-Ou-Mandel quantum interference with a 91+/-16% visibility after subtracting multi-photon noise due to high pump power. Our demonstration paves the way for scalable multiplexing of many non-deterministic photon sources to a single near-deterministic source, which will be of benefit to future quantum photonic technologies.

  5. Spironucleus meleagridis, an enteric diplomonad protozoan of cockatiels (Nymphicus hollandicus): preliminary molecular characterization and association with clinical disease.

    PubMed

    Levy, M G; Powers, L V; Gore, K C; Marr, H S

    2015-03-15

    A flagellated enteric diplomonad protozoan consistent with Spironucleus meleagridis (formerly Hexamita meleagridis) associated with gastrointestinal disease and mortality in psittacine birds including cockatiels (Nymphicus hollandicus) has been sporadically described in the literature. However, molecular characterization of psittacine protozoal isolates had not yet been performed. The 16S rRNA gene from a protozoan persistently shed in the feces in a small group of cockatiels demonstrated a 98% molecular identity with S. meleagridis isolated from turkeys. Based on these sequence data, a diagnostic PCR assay was developed to detect the presence of S. meleagridis. Nineteen privately owned pet cockatiels from unrelated households were clinically evaluated. All birds microscopically positive for this organism were PCR positive, with several additional birds microscopically negative but PCR positive. Many of the birds identified as positive for S. meleagridis by fecal PCR had signs of gastrointestinal disease such as diarrhea, soft feces, and melena, whereas none of the birds that tested negative had gastrointestinal signs. Examination of feces from two unrelated cockatiel breeding facilities revealed 70% and 86% PCR positive rates. Prevalence of infection and incidence of clinical disease, including factors that lead to clinical manifestation such as viral, bacterial, or mycotic coinfections, are not yet known and warrant further study, but spironucleosis is likely an under-recognized disease in cockatiels.

  6. Noisy quantum walks of two indistinguishable interacting particles

    NASA Astrophysics Data System (ADS)

    Siloi, Ilaria; Benedetti, Claudia; Piccinini, Enrico; Piilo, Jyrki; Maniscalco, Sabrina; Paris, Matteo G. A.; Bordone, Paolo

    2017-02-01

    We investigate the dynamics of continuous-time two-particle quantum walks on a one-dimensional noisy lattice. Depending on the initial condition, we show how the interplay between particle indistinguishability and interaction determines distinct propagation regimes. A realistic model for the environment is considered by introducing non-Gaussian noise as time-dependent fluctuations of the tunneling amplitudes between adjacent sites. We observe that the combined effect of particle interaction and fast noise (weak coupling with the environment) provides a faster propagation compared to the noiseless case. This effect can be understood in terms of the band structure of the Hubbard model, and a detailed analysis as a function of both noise and system parameters is presented.

  7. Reconstructible Phylogenetic Networks: Do Not Distinguish the Indistinguishable

    PubMed Central

    Pardi, Fabio; Scornavacca, Celine

    2015-01-01

    Phylogenetic networks represent the evolution of organisms that have undergone reticulate events, such as recombination, hybrid speciation or lateral gene transfer. An important way to interpret a phylogenetic network is in terms of the trees it displays, which represent all the possible histories of the characters carried by the organisms in the network. Interestingly, however, different networks may display exactly the same set of trees, an observation that poses a problem for network reconstruction: from the perspective of many inference methods such networks are indistinguishable. This is true for all methods that evaluate a phylogenetic network solely on the basis of how well the displayed trees fit the available data, including all methods based on input data consisting of clades, triples, quartets, or trees with any number of taxa, and also sequence-based approaches such as popular formalisations of maximum parsimony and maximum likelihood for networks. This identifiability problem is partially solved by accounting for branch lengths, although this merely reduces the frequency of the problem. Here we propose that network inference methods should only attempt to reconstruct what they can uniquely identify. To this end, we introduce a novel definition of what constitutes a uniquely reconstructible network. For any given set of indistinguishable networks, we define a canonical network that, under mild assumptions, is unique and thus representative of the entire set. Given data that underwent reticulate evolution, only the canonical form of the underlying phylogenetic network can be uniquely reconstructed. While on the methodological side this will imply a drastic reduction of the solution space in network inference, for the study of reticulate evolution this is a fundamental limitation that will require an important change of perspective when interpreting phylogenetic networks. PMID:25849429

  8. Reconstructible phylogenetic networks: do not distinguish the indistinguishable.

    PubMed

    Pardi, Fabio; Scornavacca, Celine

    2015-04-01

    Phylogenetic networks represent the evolution of organisms that have undergone reticulate events, such as recombination, hybrid speciation or lateral gene transfer. An important way to interpret a phylogenetic network is in terms of the trees it displays, which represent all the possible histories of the characters carried by the organisms in the network. Interestingly, however, different networks may display exactly the same set of trees, an observation that poses a problem for network reconstruction: from the perspective of many inference methods such networks are "indistinguishable". This is true for all methods that evaluate a phylogenetic network solely on the basis of how well the displayed trees fit the available data, including all methods based on input data consisting of clades, triples, quartets, or trees with any number of taxa, and also sequence-based approaches such as popular formalisations of maximum parsimony and maximum likelihood for networks. This identifiability problem is partially solved by accounting for branch lengths, although this merely reduces the frequency of the problem. Here we propose that network inference methods should only attempt to reconstruct what they can uniquely identify. To this end, we introduce a novel definition of what constitutes a uniquely reconstructible network. For any given set of indistinguishable networks, we define a canonical network that, under mild assumptions, is unique and thus representative of the entire set. Given data that underwent reticulate evolution, only the canonical form of the underlying phylogenetic network can be uniquely reconstructed. While on the methodological side this will imply a drastic reduction of the solution space in network inference, for the study of reticulate evolution this is a fundamental limitation that will require an important change of perspective when interpreting phylogenetic networks.

  9. General criterion for the entanglement of two indistinguishable particles

    SciTech Connect

    Ghirardi, GianCarlo; Marinatto, Luca

    2004-07-01

    We relate the notion of entanglement for quantum systems composed of two identical constituents to the impossibility of attributing a complete set of properties to both particles. This implies definite constraints on the mathematical form of the state vector associated with the whole system. We then analyze separately the cases of fermion and boson systems, and we show how the consideration of both the Slater-Schmidt number of the fermionic and bosonic analog of the Schmidt decomposition of the global state vector and the von Neumann entropy of the one-particle reduced density operators can supply us with a consistent criterion for detecting entanglement. In particular, the consideration of the von Neumann entropy is particularly useful in deciding whether the correlations of the considered states are simply due to the indistinguishability of the particles involved or are a genuine manifestation of the entanglement. The treatment leads to a full clarification of the subtle aspects of entanglement of two identical constituents which have been a source of embarrassment and of serious misunderstandings in the recent literature.

  10. Measurement of photon indistinguishability to a quantifiable uncertainty using a Hong-Ou-Mandel interferometer

    SciTech Connect

    Thomas, Peter J.; Cheung, Jessica Y.; Chunnilall, Christopher J.; Dunn, Malcolm H.

    2010-04-10

    We present a method for using the Hong-Ou-Mandel (HOM) interference technique to quantify photon indistinguishability within an associated uncertainty. The method allows the relative importance of various experimental factors affecting the HOM visibility to be identified, and enables the actual indistinguishability, with an associated uncertainty, to be estimated from experimentally measured quantities. A measurement equation has been derived that accounts for the non-ideal performance of the interferometer. The origin of each term of the equation is explained, along with procedures for their experimental evaluation and uncertainty estimation. These uncertainties are combined to give an overall uncertainty for the derived photon indistinguishability. The analysis was applied to measurements from an interferometer sourced with photon pairs from a parametric downconversion process. The measured photon indistinguishably was found to be 0.954+/-0.036 by using the prescribed method.

  11. The Gibbs paradox and the physical criteria for indistinguishability of identical particles

    NASA Astrophysics Data System (ADS)

    Unnikrishnan, C. S.

    2016-08-01

    Gibbs paradox in the context of statistical mechanics addresses the issue of additivity of entropy of mixing gases. The usual discussion attributes the paradoxical situation to classical distinguishability of identical particles and credits quantum theory for enabling indistinguishability of identical particles to solve the problem. We argue that indistinguishability of identical particles is already a feature in classical mechanics and this is clearly brought out when the problem is treated in the language of information and associated entropy. We pinpoint the physical criteria for indistinguishability that is crucial for the treatment of the Gibbs’ problem and the consistency of its solution with conventional thermodynamics. Quantum mechanics provides a quantitative criterion, not possible in the classical picture, for the degree of indistinguishability in terms of visibility of quantum interference, or overlap of the states as pointed out by von Neumann, thereby endowing the entropy expression with mathematical continuity and physical reasonableness.

  12. Efficient generation of indistinguishable single photons on-demand at telecom wavelengths

    NASA Astrophysics Data System (ADS)

    Kim, Jehyung; Cai, Tao; Richardson, Christopher; Leavitt, Richard; Waks, Edo

    Highly efficient single photon sources are important building blocks for optical quantum information processing. For practical use and long-distance quantum communication, single photons should have fiber-compatible telecom wavelengths. In addition, most quantum communication applications require high degree of indistinguishability of single photons, such that they exhibit interference on a beam splitter. However, deterministic generation of indistinguishable single photons with high brightness remains a challenging problem in particular at telecom wavelengths. We demonstrate a telecom wavelength source of indistinguishable single photons using an InAs/InP quantum dot in a nanophotonic cavity. To obtain the efficient single quantum dot emission, we employ the higher order mode in L3 photonic crystal cavity that shows a nearly Gaussian transverse mode profile and results in out-coupling efficiency exceeding 46 % and unusual bright single quantum dot emission exceeding 1.5 million counts per second at a detector. We also observe Purcell enhanced spontaneous emission rate as large as 4 and high linear polarization ratio of 0.96 for the coupled dots. Using this source, we generate high purity single photons at 1.3 μm wavelength and demonstrate the indistinguishable nature of the emission using a two-photon interference measurement.

  13. Enhanced indistinguishability of in-plane single photons by resonance fluorescence on an integrated quantum dot

    NASA Astrophysics Data System (ADS)

    Kalliakos, Sokratis; Brody, Yarden; Bennett, Anthony J.; Ellis, David J. P.; Skiba-Szymanska, Joanna; Farrer, Ian; Griffiths, Jonathan P.; Ritchie, David A.; Shields, Andrew J.

    2016-10-01

    Integrated quantum light sources in photonic circuits are envisaged as the building blocks of future on-chip architectures for quantum logic operations. While semiconductor quantum dots have been proven to be the highly efficient emitters of quantum light, their interaction with the host material induces spectral decoherence, which decreases the indistinguishability of the emitted photons and limits their functionality. Here, we show that the indistinguishability of in-plane photons can be greatly enhanced by performing resonance fluorescence on a quantum dot coupled to a photonic crystal waveguide. We find that the resonant optical excitation of an exciton state induces an increase in the emitted single-photon coherence by a factor of 15. Two-photon interference experiments reveal a visibility of 0.80 ± 0.03, which is in good agreement with our theoretical model. Combined with the high in-plane light-injection efficiency of photonic crystal waveguides, our results pave the way for the use of this system for the on-chip generation and transmission of highly indistinguishable photons.

  14. On the simulation of indistinguishable fermions in the many-body Wigner formalism

    NASA Astrophysics Data System (ADS)

    Sellier, J. M.; Dimov, I.

    2015-01-01

    The simulation of quantum systems consisting of interacting, indistinguishable fermions is an incredible mathematical problem which poses formidable numerical challenges. Many sophisticated methods addressing this problem are available which are based on the many-body Schrödinger formalism. Recently a Monte Carlo technique for the resolution of the many-body Wigner equation has been introduced and successfully applied to the simulation of distinguishable, spinless particles. This numerical approach presents several advantages over other methods. Indeed, it is based on an intuitive formalism in which quantum systems are described in terms of a quasi-distribution function, and highly scalable due to its Monte Carlo nature. In this work, we extend the many-body Wigner Monte Carlo method to the simulation of indistinguishable fermions. To this end, we first show how fermions are incorporated into the Wigner formalism. Then we demonstrate that the Pauli exclusion principle is intrinsic to the formalism. As a matter of fact, a numerical simulation of two strongly interacting fermions (electrons) is performed which clearly shows the appearance of a Fermi (or exchange-correlation) hole in the phase-space, a clear signature of the presence of the Pauli principle. To conclude, we simulate 4, 8 and 16 non-interacting fermions, isolated in a closed box, and show that, as the number of fermions increases, we gradually recover the Fermi-Dirac statistics, a clear proof of the reliability of our proposed method for the treatment of indistinguishable particles.

  15. Indistinguishable Synaptic Pharmacodynamics of the N-Methyl-d-Aspartate Receptor Channel Blockers Memantine and Ketamine

    PubMed Central

    Emnett, Christine M.; Eisenman, Lawrence N.; Taylor, Amanda M.; Izumi, Yukitoshi; Zorumski, Charles F.

    2013-01-01

    Memantine and ketamine, voltage- and activation-dependent channel blockers of N-methyl-d-aspartate (NMDA) receptors (NMDARs), have enjoyed a recent resurgence in clinical interest. Steady-state pharmacodynamic differences between these blockers have been reported, but it is unclear whether the compounds differentially affect dynamic physiologic signaling. In this study, we explored nonequilibrium conditions relevant to synaptic transmission in hippocampal networks in dissociated culture and hippocampal slices. Equimolar memantine and ketamine had indistinguishable effects on the following measures: steady-state NMDA currents, NMDAR excitatory postsynaptic current (EPSC) decay kinetics, progressive EPSC inhibition during repetitive stimulation, and extrasynaptic NMDAR inhibition. Therapeutic drug efficacy and tolerability of memantine have been attributed to fast kinetics and strong voltage dependence. However, pulse depolarization in drug presence revealed a surprisingly slow and similar time course of equilibration for the two compounds, although memantine produced a more prominent fast component (62% versus 48%) of re-equilibration. Simulations predicted that low gating efficacy underlies the slow voltage–dependent relief from block. This prediction was empirically supported by faster voltage-dependent blocker re-equilibration with several experimental manipulations of gating efficacy. Excitatory postsynaptic potential–like voltage commands produced drug differences only with large, prolonged depolarizations unlikely to be attained physiologically. In fact, we found no difference between drugs on measures of spontaneous network activity or acute effects on plasticity in hippocampal slices. Despite indistinguishable synaptic pharmacodynamics, ketamine provided significantly greater neuroprotection from damage induced by oxygen glucose deprivation, consistent with the idea that under extreme depolarizing conditions, the biophysical difference between drugs

  16. Isolation of a urinary digitalis-like factor indistinguishable from digoxin

    SciTech Connect

    Goto, A.; Ishiguro, T.; Yamada, K.; Ishii, M.; Yoshioka, M.; Eguchi, C.; Shimora, M.; Sugimoto, T. )

    1990-12-31

    A digitalis-like factor has been purified to apparent homogeneity from human urine based on the inhibitory effect on ({sup 3}H) ouabain binding to intact human erythrocytes. The purification scheme involved large scale adsorption followed by preparative, semipreparative and analytical high-performance liquid chromatography. The purified material showed a prominent digoxin-like immunoreactivity. The behaviour of the isolated substance was identical to that of authentic digoxin in three high-performance liquid chromatography and three thin-layer chromatography systems. Moreover, fast atom bombardment mass spectrum and proton nuclear magnetic resonance spectrum suggested that the purified material may be indistinguishable from digoxin.

  17. Result-indistinguishable zero-knowledge proofs: Increased power and constant-round protocols

    NASA Astrophysics Data System (ADS)

    di Crescenzo, Giovanni; Sakurai, Kouichi; Yung, Moti

    We investigate result-indistinguishable perfect zero-knowledge proof systems [8] for "transferring the decision of whether the membership of an input in a language is true or not". Previously only a single number-theoretic language was known to have such a proof system and possible extensions were left as an open question. We show that all known random self-reducible languages (e.g., graph isomorphism, quadratic residuosity, discrete log) and compositions over them have such systems. We also consider techniques for constant-round protocols for these languages in this model, and obtain a 5 round protocol scheme.

  18. In-plane emission of indistinguishable photons generated by an integrated quantum emitter

    SciTech Connect

    Kalliakos, Sokratis Bennett, Anthony J.; Ward, Martin B.; Ellis, David J. P.; Skiba-Szymanska, Joanna; Shields, Andrew J.; Brody, Yarden; Schwagmann, Andre; Farrer, Ian; Griffiths, Jonathan P.; Jones, Geb A. C.; Ritchie, David A.

    2014-06-02

    We demonstrate the emission of indistinguishable photons along a semiconductor chip originating from carrier recombination in an InAs quantum dot. The emitter is integrated in the waveguiding region of a photonic crystal structure, allowing for on-chip light propagation. We perform a Hong-Ou-Mandel-type of experiment with photons collected from the exit of the waveguide, and we observe two-photon interference under continuous wave excitation. Our results pave the way for the integration of quantum emitters in advanced photonic quantum circuits.

  19. Conformal blocks on a 2-sphere with indistinguishable punctures and implications on black hole entropy

    NASA Astrophysics Data System (ADS)

    Majhi, Abhishek

    2016-11-01

    The dimensionality of the Hilbert space of a Chern-Simons theory on a 3-fold, in the presence of Wilson lines carrying spin representations, had been counted by using its link with the Wess-Zumino theory, with level k, on the 2-sphere with points (to be called punctures) marked by the piercing of the corresponding Wilson lines and carrying the respective spin representations. It is shown, in the weak coupling (large k) limit, the formula decouples into two characteristically distinct parts; one mimics the dimensionality of the Hilbert space of a collection of non-interacting spin systems and the other is an effective overall correction contributed by all the punctures. The exact formula yield from this counting has been shown earlier to have resulted from the consideration of the punctures to be distinguishable. We investigate the same counting problem by considering the punctures to be indistinguishable. Although the full formula remains undiscovered, nonetheless, we are able to impose the relevant statistics for indistinguishable punctures in the approximate formula resulting from the weak coupling limit. As an implication of this counting, in the context of its relation to that of black hole entropy calculation in quantum geometric approach, we are able to show that the logarithmic area correction, with a coefficient of - 3 / 2, that results in this method of entropy calculation, in independent of whether the punctures are distinguishable or not.

  20. An electrically driven cavity-enhanced source of indistinguishable photons with 61% overall efficiency

    NASA Astrophysics Data System (ADS)

    Schlehahn, A.; Thoma, A.; Munnelly, P.; Kamp, M.; Höfling, S.; Heindel, T.; Schneider, C.; Reitzenstein, S.

    2016-04-01

    We report on an electrically driven efficient source of indistinguishable photons operated at pulse-repetition rates f up to 1.2 GHz. The quantum light source is based on a p-i-n-doped micropillar cavity with integrated self-organized quantum dots, which exploits cavity quantum electrodynamics effects in the weak coupling regime to enhance the emission of a single quantum emitter coupled to the cavity mode. We achieve an overall single-photon extraction efficiency of (61 ± 11) % for a device triggered electrically at f = 625 MHz. Analyzing the suppression of multi-photon emission events as a function of excitation repetition rate, we observe single-photon emission associated with g(2)HBT(0) values between 0.076 and 0.227 for f ranging from 373 MHz to 1.2 GHz. Hong-Ou-Mandel-type two-photon interference experiments under pulsed current injection at 487 MHz reveal a photon-indistinguishability of (41.1 ± 9.5) % at a single-photon emission rate of (92 ± 23) MHz.

  1. Low-noise quantum frequency down-conversion of indistinguishable photons (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Kambs, Benjamin; Kettler, Jan; Bock, Matthias; Becker, Jonas; Arend, Carsten; Jetter, Michael; Michler, Peter; Becher, Christoph

    2016-04-01

    Single-photon sources based on quantum dots have been shown to exhibit almost ideal properties such as high brightness and purity in terms of clear anti-bunching as well as high two-photon interference visibilities of the emitted photons, making them promising candidates for different quantum information applications such as quantum computing, quantum communication and quantum teleportation. However, as most single-photon sources also quantum dots typically emit light at wavelengths of electronic transitions within the visible or the near infrared range. In order to establish quantum networks with remote building blocks, low-loss single photons at telecom wavelengths are preferable, though. Despite recent progress on emitters of telecom-photons, the most efficient single-photon sources still work at shorter wavelengths. On that matter, quantum frequency down-conversion, being a nonlinear optical process, has been used in recent years to alter the wavelength of single photons to the telecom wavelength range while conserving their nonclassical properties. Characteristics such as lifetime, first-order coherence, anti-bunching and entanglement have been shown to be conserved or even improved due to background suppression during the conversion process, while the conservation of indistinguishability was yet to be shown. Here we present our experimental results on quantum frequency down-conversion of single photons emitted by an InAs/GaAs quantum dot at 903.6 nm following a pulsed excitation of a p-shell exciton at 884 nm. The emitted fluorescence photons are mixed with a strong pump-field at 2155 nm inside a periodically poled lithium niobate ridge waveguide and converted to 1557 nm. Common issues of a large background due to Raman-scattered pump-light photons spectrally overlapping with the converted single photons could largely be avoided, as the pump-wavelength was chosen to be fairly longer than the target wavelength. Additional narrowband spectral filtering at the

  2. The queenslandensis and the type Form of the Dengue Fever Mosquito (Aedes aegypti L.) Are Genomically Indistinguishable

    PubMed Central

    Filipović, Igor; Callahan, Ashley G.; Stanford, Darren; Chan, Abigail; Lam-Phua, Sai Gek; Tan, Cheong Huat; Hoffmann, Ary Anthony

    2016-01-01

    Background The mosquito Aedes aegypti (L.) is a major vector of viral diseases like dengue fever, Zika and chikungunya. Aedes aegypti exhibits high morphological and behavioral variation, some of which is thought to be of epidemiological significance. Globally distributed domestic Ae. aegypti have often been grouped into (i) the very pale variety queenslandensis and (ii) the type form. Because the two color forms co-occur across most of their range, there is interest in understanding how freely they interbreed. This knowledge is particularly important for control strategies that rely on mating compatibilities between the release and target mosquitoes, such as Wolbachia releases and SIT. To address this question, we analyzed nuclear and mitochondrial genome-wide variation in the co-occurring pale and type Ae. aegypti from northern Queensland (Australia) and Singapore. Methods/Findings We typed 74 individuals at a 1170 bp-long mitochondrial sequence and at 16,569 nuclear SNPs using a customized double-digest RAD sequencing. 11/29 genotyped individuals from Singapore and 11/45 from Queensland were identified as var. queenslandensis based on the diagnostic scaling patterns. We found 24 different mitochondrial haplotypes, seven of which were shared between the two forms. Multivariate genetic clustering based on nuclear SNPs corresponded to individuals’ geographic location, not their color. Several family groups consisted of both forms and three queenslandensis individuals were Wolbachia infected, indicating previous breeding with the type form which has been used to introduce Wolbachia into Ae. aegypti populations. Conclusion Aedes aegypti queenslandensis are genomically indistinguishable from the type form, which points to these forms freely interbreeding at least in Australia and Singapore. Based on our findings, it is unlikely that the presence of very pale Ae. aegypti will affect the success of Aedes control programs based on Wolbachia-infected, sterile or RIDL

  3. Phase-locked indistinguishable photons with synthesized waveforms from a solid-state source

    NASA Astrophysics Data System (ADS)

    Matthiesen, Clemens; Geller, Martin; Schulte, Carsten H. H.; Le Gall, Claire; Hansom, Jack; Li, Zhengyong; Hugues, Maxime; Clarke, Edmund; Atatüre, Mete

    2013-03-01

    Resonance fluorescence in the Heitler regime provides access to single photons with coherence well beyond the Fourier transform limit of the transition, and holds the promise to circumvent environment-induced dephasing common to all solid-state systems. Here we demonstrate that the coherently generated single photons from a single self-assembled InAs quantum dot display mutual coherence with the excitation laser on a timescale exceeding 3 s. Exploiting this degree of mutual coherence, we synthesize near-arbitrary coherent photon waveforms by shaping the excitation laser field. In contrast to post-emission filtering, our technique avoids both photon loss and degradation of the single-photon nature for all synthesized waveforms. By engineering pulsed waveforms of single photons, we further demonstrate that separate photons generated coherently by the same laser field are fundamentally indistinguishable, lending themselves to the creation of distant entanglement through quantum interference.

  4. Indistinguishability and correlations of photons generated by quantum emitters undergoing spectral diffusion

    PubMed Central

    Dorfman, Konstantin E.; Mukamel, Shaul

    2014-01-01

    Photon-based quantum information processing is based on manipulating multi photon interference. We focus on the Hong-Ou-Mandel (HOM) dip in the photon coincidence rate which provides a direct measure of interference of indistinguishable photons linked to their Bose statistics. The effect has been first observed with entangled photons generated by parametric down conversion and then extended to independent emitters. Fluctuations caused by coupling between emitters and a bath can erode the interference which causes the dip. Here we show how the magnitude and shape of the HOM dip is affected by spectral diffusion induced by coupling to a brownian oscillator bath. Conditions for maintaining and controlling the interference are specified. PMID:24510121

  5. Screening Nuclear Field Fluctuations in Quantum Dots for Indistinguishable Photon Generation.

    PubMed

    Malein, R N E; Santana, T S; Zajac, J M; Dada, A C; Gauger, E M; Petroff, P M; Lim, J Y; Song, J D; Gerardot, B D

    2016-06-24

    A semiconductor quantum dot can generate highly coherent and indistinguishable single photons. However, intrinsic semiconductor dephasing mechanisms can reduce the visibility of two-photon interference. For an electron in a quantum dot, a fundamental dephasing process is the hyperfine interaction with the nuclear spin bath. Here, we directly probe the consequence of the fluctuating nuclear spins on the elastic and inelastic scattered photon spectra from a resident electron in a single dot. We find the in-plane component of the nuclear Overhauser field leads to detuned Raman scattered photons, broadened over experimental time scales by field fluctuations, which are distinguishable from both the elastic and incoherent components of the resonance fluorescence. This significantly reduces two-photon interference visibility. However, we demonstrate successful screening of the nuclear spin noise, which enables the generation of coherent single photons that exhibit high visibility two-photon interference.

  6. Nucleotide specificities of anterograde and retrograde organelle transport in Reticulomyxa are indistinguishable.

    PubMed

    Schliwa, M; Shimizu, T; Vale, R D; Euteneuer, U

    1991-03-01

    Membrane-bound organelles move bidirectionally along microtubules in the freshwater ameba, Reticulomyxa. We have examined the nucleotide requirements for transport in a lysed cell model and compared them with kinesin and dynein-driven motility in other systems. Both anterograde and retrograde transport in Reticulomyxa show features characteristic of dynein but not of kinesin-powered movements: organelle transport is reactivated only by ATP and no other nucleoside triphosphates; the Km and Vmax of the ATP-driven movements are similar to values obtained for dynein rather than kinesin-driven movement; and of 15 ATP analogues tested for their ability to promote organelle transport, only 4 of them did. This narrow specificity resembles that of dynein-mediated in vitro transport and is dissimilar to the broad specificity of the kinesin motor (Shimizu, T., K. Furusawa, S. Ohashi, Y. Y. Toyoshima, M. Okuno, F. Malik, and R. D. Vale. 1991. J. Cell Biol. 112: 1189-1197). Remarkably, anterograde and retrograde organelle transport cannot be distinguished at all with respect to nucleotide specificity, kinetics of movement, and the ability to use the ATP analogues. Since the "kinetic fingerprints" of the motors driving transport in opposite directions are indistinguishable, the same type of motor(s) may be involved in the two directions of movement.

  7. [Case of tsutsugamushi disease (scrub typhus) presenting with fever and pain indistinguishable from trigeminal neuralgia].

    PubMed

    Arai, Motomi; Nakamura, Asuka; Shichi, Daisuke

    2007-06-01

    A 64-year-old man visited our clinic with a 9-day history of headache and fever. He had frequent, severe, electric shock-like pain in his left eye, forehead, and scalp. The body temperature was 37.1 degrees. Cranial nerve functions were intact. Limb weakness and stiff neck were absent. There were injection of the conjunctiva, a red rash on the trunk, and an eschar in the axilla. Abnormal laboratory findings included AST 40 IU, ALT 44 IU, CRP 16.0 mg/dl, WBC 11,090/microl, and proteinuria. CT scan was unremarkable. The cerebrospinal fluid (CSF) showed 2 polymorphs/microl, 6 lymphocytes/microl, 65 mg/dl of glucose, and 42 mg/dl of protein. A diagnosis of scrub typhus was made. Treatment with minocycline brought about prompt disappearance of the fever and dramatic clinical improvement. Increased antibody titers confirmed the diagnosis. Although almost all patients present with high fever and severe headache, only a small number of patients have CSF pleocytosis. The present case illustrates that pain in scrub typhus is, on rare occasions, indistinguishable from trigeminal neuralgia. Neurologists should have a high index of suspicion in patients with fever and headache during the epidemic season and should be familiar with the systemic symptoms and signs.

  8. On-demand semiconductor single-photon source with near-unity indistinguishability.

    PubMed

    He, Yu-Ming; He, Yu; Wei, Yu-Jia; Wu, Dian; Atatüre, Mete; Schneider, Christian; Höfling, Sven; Kamp, Martin; Lu, Chao-Yang; Pan, Jian-Wei

    2013-03-01

    Single-photon sources based on semiconductor quantum dots offer distinct advantages for quantum information, including a scalable solid-state platform, ultrabrightness and interconnectivity with matter qubits. A key prerequisite for their use in optical quantum computing and solid-state networks is a high level of efficiency and indistinguishability. Pulsed resonance fluorescence has been anticipated as the optimum condition for the deterministic generation of high-quality photons with vanishing effects of dephasing. Here, we generate pulsed single photons on demand from a single, microcavity-embedded quantum dot under s-shell excitation with 3 ps laser pulses. The π pulse-excited resonance-fluorescence photons have less than 0.3% background contribution and a vanishing two-photon emission probability. Non-postselective Hong-Ou-Mandel interference between two successively emitted photons is observed with a visibility of 0.97(2), comparable to trapped atoms and ions. Two single photons are further used to implement a high-fidelity quantum controlled-NOT gate.

  9. Major Ampullate Spider Silk with Indistinguishable Spidroin Dope Conformations Leads to Different Fiber Molecular Structures

    PubMed Central

    Dionne, Justine; Lefèvre, Thierry; Auger, Michèle

    2016-01-01

    To plentifully benefit from its properties (mechanical, optical, biological) and its potential to manufacture green materials, the structure of spider silk has to be known accurately. To this aim, the major ampullate (MA) silk of Araneus diadematus (AD) and Nephila clavipes (NC) has been compared quantitatively in the liquid and fiber states using Raman spectromicroscopy. The data show that the spidroin conformations of the two dopes are indistinguishable despite their specific amino acid composition. This result suggests that GlyGlyX and GlyProGlyXX amino acid motifs (X = Leu, Glu, Tyr, Ser, etc.) are conformationally equivalent due to the chain flexibility in the aqueous environment. Species-related sequence specificity is expressed more extensively in the fiber: the β-sheet content is lower and width of the orientation distribution of the carbonyl groups is broader for AD (29% and 58°, respectively) as compared to NC (37% and 51°, respectively). β-Sheet content values are close to the proportion of polyalanine segments, suggesting that β-sheet formation is mainly dictated by the spidroin sequence. The extent of molecular alignment seems to be related to the presence of proline (Pro) that may decrease conformational flexibility and inhibit chain extension and alignment upon drawing. It appears that besides the presence of Pro, secondary structure and molecular orientation contribute to the different mechanical properties of MA threads. PMID:27548146

  10. Dynamics of Hubbard Hamiltonians with the multiconfigurational time-dependent Hartree method for indistinguishable particles

    NASA Astrophysics Data System (ADS)

    Lode, Axel U. J.; Bruder, Christoph

    2016-07-01

    We apply the multiconfigurational time-dependent Hartree method for indistinguishable particles (MCTDH-X) to systems of bosons or fermions in lattices described by Hubbard-type Hamiltonians with long-range or short-range interparticle interactions. The wave function is expanded in a variationally optimized time-dependent many-body basis generated by a set of effective creation operators that are related to the original particle creation operators by a time-dependent unitary transform. We use the time-dependent variational principle for the coefficients of this transform and the expansion coefficients of the wave function expressed in the time-dependent many-body basis as variational parameters to derive equations of motion. The convergence of MCTDH-X is shown by comparing its results to the exact diagonalization of one-, two-, and three-dimensional lattices filled with bosons with contact interactions. We use MCTDH-X to study the buildup of correlations in the long-time splitting dynamics of a Bose-Einstein condensate loaded into a large two-dimensional lattice subject to a barrier that is ramped up in the center. We find that the system is split into two parts with emergent time-dependent correlations that depend on the ramping time—for most barrier-raising times the system becomes twofold fragmented, but for some of the very fast ramps, the system shows revivals of coherence.

  11. No ψ-epistemic model can fully explain the indistinguishability of quantum states.

    PubMed

    Barrett, Jonathan; Cavalcanti, Eric G; Lal, Raymond; Maroney, Owen J E

    2014-06-27

    According to a recent no-go theorem [M. Pusey, J. Barrett and T. Rudolph, Nat. Phys. 8, 475 (2012)], models in which quantum states correspond to probability distributions over the values of some underlying physical variables must have the following feature: the distributions corresponding to distinct quantum states do not overlap. In such a model, it cannot coherently be maintained that the quantum state merely encodes information about underlying physical variables. The theorem, however, considers only models in which the physical variables corresponding to independently prepared systems are independent, and this has been used to challenge the conclusions of that work. Here we consider models that are defined for a single quantum system of dimension d, such that the independence condition does not arise, and derive an upper bound on the extent to which the probability distributions can overlap. In particular, models in which the quantum overlap between pure states is equal to the classical overlap between the corresponding probability distributions cannot reproduce the quantum predictions in any dimension d ≥ 3. Thus any ontological model for quantum theory must postulate some extra principle, such as a limitation on the measurability of physical variables, to explain the indistinguishability of quantum states. Moreover, we show that as d→∞, the ratio of classical and quantum overlaps goes to zero for a class of states. The result is noise tolerant, and an experiment is motivated to distinguish the class of models ruled out from quantum theory.

  12. Nucleotide specificities of anterograde and retrograde organelle transport in Reticulomyxa are indistinguishable

    PubMed Central

    1991-01-01

    Membrane-bound organelles move bidirectionally along microtubules in the freshwater ameba, Reticulomyxa. We have examined the nucleotide requirements for transport in a lysed cell model and compared them with kinesin and dynein-driven motility in other systems. Both anterograde and retrograde transport in Reticulomyxa show features characteristic of dynein but not of kinesin-powered movements: organelle transport is reactivated only by ATP and no other nucleoside triphosphates; the Km and Vmax of the ATP-driven movements are similar to values obtained for dynein rather than kinesin-driven movement; and of 15 ATP analogues tested for their ability to promote organelle transport, only 4 of them did. This narrow specificity resembles that of dynein-mediated in vitro transport and is dissimilar to the broad specificity of the kinesin motor (Shimizu, T., K. Furusawa, S. Ohashi, Y. Y. Toyoshima, M. Okuno, F. Malik, and R. D. Vale. 1991. J. Cell Biol. 112: 1189-1197). Remarkably, anterograde and retrograde organelle transport cannot be distinguished at all with respect to nucleotide specificity, kinetics of movement, and the ability to use the ATP analogues. Since the "kinetic fingerprints" of the motors driving transport in opposite directions are indistinguishable, the same type of motor(s) may be involved in the two directions of movement. PMID:1825662

  13. Quantization and superselection sectors III: Multiply connected spaces and indistinguishable particles

    NASA Astrophysics Data System (ADS)

    Landsman, N. P. Klaas

    2016-09-01

    We reconsider the (non-relativistic) quantum theory of indistinguishable particles on the basis of Rieffel’s notion of C∗-algebraic (“strict”) deformation quantization. Using this formalism, we relate the operator approach of Messiah and Greenberg (1964) to the configuration space approach pioneered by Souriau (1967), Laidlaw and DeWitt-Morette (1971), Leinaas and Myrheim (1977), and others. In dimension d > 2, the former yields bosons, fermions, and paraparticles, whereas the latter seems to leave room for bosons and fermions only, apparently contradicting the operator approach as far as the admissibility of parastatistics is concerned. To resolve this, we first prove that in d > 2 the topologically non-trivial configuration spaces of the second approach are quantized by the algebras of observables of the first. Secondly, we show that the irreducible representations of the latter may be realized by vector bundle constructions, among which the line bundles recover the results of the second approach. Mathematically speaking, representations on higher-dimensional bundles (which define parastatistics) cannot be excluded, which render the configuration space approach incomplete. Physically, however, we show that the corresponding particle states may always be realized in terms of bosons and/or fermions with an unobserved internal degree of freedom (although based on non-relativistic quantum mechanics, this conclusion is analogous to the rigorous results of the Doplicher-Haag-Roberts analysis in algebraic quantum field theory, as well as to the heuristic arguments which led Gell-Mann and others to QCD (i.e. Quantum Chromodynamics)).

  14. Indistinguishable transcriptional profiles between in vitro- and in vivo-produced bovine fetuses.

    PubMed

    Jiang, Le; Marjani, Sadie L; Bertolini, Marcelo; Anderson, Gary B; Yang, Xiangzhong; Tian, X Cindy

    2011-09-01

    During the past several decades, in vitro fertilization (IVF) has been increasingly used both in animal production and human infertility treatment. Animals derived from in vitro manipulation are occasionally associated with abnormal offspring syndrome (AOS) and other developmental abnormalities. By studying gene expression of in vitro-produced (IVP) embryos/animals, we gain an indicator of how well this procedure mimics the in vivo environment. Most previous studies of this nature have focused on only a few genes at a time or have been limited to studying the pre-implantation stage; a global view of how gene transcription may be influenced by in vitro procedures during fetal development has yet to be ascertained. To this end, we collected liver and placental tissue samples from IVP and in vivo control bovine fetuses at days 90 and 180 of gestation. We used a bovine 13K oligonucleotide microarray to investigate the transcriptional profiles in both tissues from IVP fetuses, and compared them with those of their age-matched in vivo counterparts. Surprisingly, in both liver and placental tissues, the transcriptional profiles between IVP and control fetuses, at either 90 or 180 days of gestation, were indistinguishable. A total of 879 genes were found to be significantly regulated during liver development from 90 to 180 days of gestation, but there were no gene expression changes in the placental tissue during this developmental period. Quantitative real-time RT-PCR on 11 selected genes confirmed these results. Our results have certain implications for IVF technologies, both in agriculture and in human medicine.

  15. Highly indistinguishable photons from deterministic quantum-dot microlenses utilizing three-dimensional in situ electron-beam lithography

    PubMed Central

    Gschrey, M.; Thoma, A.; Schnauber, P.; Seifried, M.; Schmidt, R.; Wohlfeil, B.; Krüger, L.; Schulze, J. -H.; Heindel, T.; Burger, S.; Schmidt, F.; Strittmatter, A.; Rodt, S.; Reitzenstein, S.

    2015-01-01

    The success of advanced quantum communication relies crucially on non-classical light sources emitting single indistinguishable photons at high flux rates and purity. We report on deterministically fabricated microlenses with single quantum dots inside which fulfil these requirements in a flexible and robust quantum device approach. In our concept we combine cathodoluminescence spectroscopy with advanced in situ three-dimensional electron-beam lithography at cryogenic temperatures to pattern monolithic microlenses precisely aligned to pre-selected single quantum dots above a distributed Bragg reflector. We demonstrate that the resulting deterministic quantum-dot microlenses enhance the photon-extraction efficiency to (23±3)%. Furthermore we prove that such microlenses assure close to pure emission of triggered single photons with a high degree of photon indistinguishability up to (80±7)% at saturation. As a unique feature, both single-photon purity and photon indistinguishability are preserved at high excitation power and pulsed excitation, even above saturation of the quantum emitter. PMID:26179766

  16. Statistics of indistinguishable particles.

    PubMed

    Wittig, Curt

    2009-07-02

    The wave function of a system containing identical particles takes into account the relationship between a particle's intrinsic spin and its statistical property. Specifically, the exchange of two identical particles having odd-half-integer spin results in the wave function changing sign, whereas the exchange of two identical particles having integer spin is accompanied by no such sign change. This is embodied in a term (-1)(2s), which has the value +1 for integer s (bosons), and -1 for odd-half-integer s (fermions), where s is the particle spin. All of this is well-known. In the nonrelativistic limit, a detailed consideration of the exchange of two identical particles shows that exchange is accompanied by a 2pi reorientation that yields the (-1)(2s) term. The same bookkeeping is applicable to the relativistic case described by the proper orthochronous Lorentz group, because any proper orthochronous Lorentz transformation can be expressed as the product of spatial rotations and a boost along the direction of motion.

  17. Nondestructive Total Excitation-Emission Fluorescence Microscopy Combined with Multi-Way Chemometric Analysis for Visually Indistinguishable Single Fiber Discrimination.

    PubMed

    Muñoz de la Peña, Arsenio; Mujumdar, Nirvani; Heider, Emily C; Goicoechea, Hector C; Muñoz de la Peña, David; Campiglia, Andres D

    2016-03-01

    The potential of total excitation-emission fluorescence microscopy combined with multiway chemometric analysis was investigated for the nondestructive forensic analysis of textile fibers. The four pairs of visually indistinguishable fibers consisted of nylon 361 dyed with acid yellow 17 and acid yellow 23, acetate satin 105B dyed with disperse blue 3 and disperse blue 14, polyester 777 dyed with disperse red 1 and disperse red 19, and acrylic 864 dyed with basic green 1 and basic green 4. Excitation emission matrices were recorded with the aid of an inverted microscope and a commercial spectrofluorimeter. The full information content of excitation-emission matrices was processed with the aid of unsupervised parallel factor analysis (PARAFAC), PARAFAC supervised by linear discriminant analysis (LDA), and discriminant unfolded partial least-squares (DU-PLS). The ability of the latter algorithm to classify the four pairs of fibers demonstrates the advantage of using the multidimensionality of fluorescence data formats for the nondestructive analysis of forensic fiber evidence.

  18. Comparison of phenotypically indistinguishable but geographically distinct Neisseria meningitidis Group B isolates in a serum bactericidal antibody assay.

    PubMed

    Findlow, Jamie; Holland, Ann; Andrews, Nick; Weynants, Vincent; Sotolongo, Franklin; Balmer, Paul; Poolman, Jan; Borrow, Ray

    2007-11-01

    The "gold standard" assay for measuring serologic protection against Neisseria meningitidis group B (MenB) is the serum bactericidal antibody (SBA) assay. Of vital importance to the outcome of the SBA assay is the choice of the target strain(s), which is often chosen on the basis of phenotype or genotype. We therefore investigated the effect on the results produced by the SBA assay of using phenotypically indistinguishable but geographically distinct MenB isolates. Nine PorA P1.19,15 and 11 PorA P1.7-2,4 MenB isolates were incorporated into the SBA assay using human complement and were assayed against sera obtained either before or after outer membrane vesicle vaccination. Large differences in the results produced by the isolates in the SBA assay were demonstrated. These included differences as great as 5.8-fold in SBA geometric mean titers and in the proportions of subjects with SBA titers of >/=4. Ranges of as many as 9 SBA titers were achieved by individual sera across the panels of isolates. To determine the reasons for the differences observed, investigations into the expression of capsular polysaccharide, PorA, PorB, Opc, and lipooligosaccharide (LOS) and into LOS sialylation were completed. However, minor differences were found between strains, indicating similar expression and no antigen masking. These results have implications for the choice of MenB target strains for inclusion in future studies of MenB vaccines and highlight the requirement for standardization of target strains between laboratories.

  19. On-Demand Single Photons with High Extraction Efficiency and Near-Unity Indistinguishability from a Resonantly Driven Quantum Dot in a Micropillar.

    PubMed

    Ding, Xing; He, Yu; Duan, Z-C; Gregersen, Niels; Chen, M-C; Unsleber, S; Maier, S; Schneider, Christian; Kamp, Martin; Höfling, Sven; Lu, Chao-Yang; Pan, Jian-Wei

    2016-01-15

    Scalable photonic quantum technologies require on-demand single-photon sources with simultaneously high levels of purity, indistinguishability, and efficiency. These key features, however, have only been demonstrated separately in previous experiments. Here, by s-shell pulsed resonant excitation of a Purcell-enhanced quantum dot-micropillar system, we deterministically generate resonance fluorescence single photons which, at π pulse excitation, have an extraction efficiency of 66%, single-photon purity of 99.1%, and photon indistinguishability of 98.5%. Such a single-photon source for the first time combines the features of high efficiency and near-perfect levels of purity and indistinguishabilty, and thus opens the way to multiphoton experiments with semiconductor quantum dots.

  20. Discriminating the indistinguishable sapwood from heartwood in discolored ancient wood by direct molecular mapping of specific extractives using time-of-flight secondary ion mass spectrometry.

    PubMed

    Saito, Kaori; Mitsutani, Takumi; Imai, Takanori; Matsushita, Yasuyuki; Fukushima, Kazuhiko

    2008-03-01

    A new method that can chemically discriminate the visually indistinguishable sapwood from heartwood in discolored woods is presented in this paper. Discriminating between sapwood and heartwood, which are normally recognized by color in cross sections of stems of tress, is important in dendrochronological dating, as well as in evaluating qualities of woods such as durability. In tree-ring chronology, the felling date, which affects the construction date of architectures, can be estimated only in woods that have a recognizable sapwood/heartwood boundary. However, the felling date cannot be estimated in discolored woods because it has indistinguishable sapwood. Time-of-flight secondary ion mass spectrometry (TOF-SIMS) analysis of specific chemical substances retained for approximately 1300 years after felling demonstrated the presence of sapwood in a discolored ancient architectural wood of Hinoki cypress (Chamaecyparis obtusa). Direct molecular mapping by TOF-SIMS clearly indicated that the specific substances, hinokinin, hinokiresinol, hinokione, and hinokiol, started to accumulate at the sapwood/heartwood boundary where only hinokinin was localized and retained predominantly in ray parenchyma cells. The result allowed the determination of the felling date of the discolored wood. TOF-SIMS has shown to be useful for investigating the distribution of minute amounts of chemical components in woods.

  1. Deterministic and robust generation of single photons from a single quantum dot with 99.5% indistinguishability using adiabatic rapid passage.

    PubMed

    Wei, Yu-Jia; He, Yu-Ming; Chen, Ming-Cheng; Hu, Yi-Nan; He, Yu; Wu, Dian; Schneider, Christian; Kamp, Martin; Höfling, Sven; Lu, Chao-Yang; Pan, Jian-Wei

    2014-11-12

    Single photons are attractive candidates of quantum bits (qubits) for quantum computation and are the best messengers in quantum networks. Future scalable, fault-tolerant photonic quantum technologies demand both stringently high levels of photon indistinguishability and generation efficiency. Here, we demonstrate deterministic and robust generation of pulsed resonance fluorescence single photons from a single semiconductor quantum dot using adiabatic rapid passage, a method robust against fluctuation of driving pulse area and dipole moments of solid-state emitters. The emitted photons are background-free, have a vanishing two-photon emission probability of 0.3% and a raw (corrected) two-photon Hong-Ou-Mandel interference visibility of 97.9% (99.5%), reaching a precision that places single photons at the threshold for fault-tolerant surface-code quantum computing. This single-photon source can be readily scaled up to multiphoton entanglement and used for quantum metrology, boson sampling, and linear optical quantum computing.

  2. Purification and partial sequencing of the nuclear autoantigen RA33 shows that it is indistinguishable from the A2 protein of the heterogeneous nuclear ribonucleoprotein complex.

    PubMed Central

    Steiner, G; Hartmuth, K; Skriner, K; Maurer-Fogy, I; Sinski, A; Thalmann, E; Hassfeld, W; Barta, A; Smolen, J S

    1992-01-01

    RA33 is a nuclear autoantigen with an apparent molecular mass of 33 kD. Autoantibodies against RA33 are found in about 30% of sera from RA patients, but only occasionally in sera from patients with other connective tissue diseases. To characterize RA33, the antigen was purified from HeLa cell nuclear extracts to more than 90% homogeneity by affinity chromatography on heparin-Sepharose and by chromatofocusing. Sequence analysis of five tryptic peptides revealed that their sequences matched corresponding sequences of the A2 protein of the heterogeneous nuclear ribonucleoprotein (hnRNP) complex. Furthermore, RA33 was shown to be present in the 40S hnRNP complex and to behave indistinguishably from A2 in binding to single stranded DNA. In summary, these data strongly indicate that RA33 and A2 are the same protein, and thus identify on a molecular level a new autoantigen. Images PMID:1522214

  3. Use of colony morphology to distinguish different enterococcal strains and species in mixed culture from clinical specimens.

    PubMed

    Qamer, Shabnam; Sandoe, Jonathan A T; Kerr, Kevin G

    2003-06-01

    Colony morphology on kanamycin esculin azide agar was investigated as a means of selecting different species and strains of enterococci from clinical specimens. Four representative colonies of each morphotype were indistinguishable by pulsed-field gel electrophoresis, biotype, and antibiogram analysis. The optimum time for identification of different colony morphotypes was 72 h.

  4. Map learning with indistinguishable locations

    NASA Technical Reports Server (NTRS)

    Basye, Kenneth; Dean, Thomas

    1989-01-01

    Nearly all spatial reasoning problems involve uncertainty of one sort or another. Uncertainty arises due to the inaccuracies of sensors used in measuring distances and angels. This is inferred as directional uncertainty. Uncertainty also arises in combining spatial information when one location is mistakenly identified with another. This is referred to as recognition uncertainty. Most problems in constructing spatial representations (maps) for the purpose of navigation involve both directional and recognition uncertainty. It is shown that a particular class of spatial reasoning problems involving the construction of representations of large-scale space can be solved efficiently even in the presence of directional and recognition uncertainty. Particular attention is paid to the problems that arise due to recognition uncertainty. The results described are applicable to the construction of global maps from satellite data as well as the construction of local navigation maps from measurements made by a rover in exploring a planetary surface.

  5. QUANTITATIVE MORPHOLOGY

    EPA Science Inventory

    Abstract: In toxicology, the role of quantitative assessment of brain morphology can be understood in the context of two types of treatment-related alterations. One type of alteration is specifically associated with treatment and is not observed in control animals. Measurement ...

  6. TRF requirements for in vitro PFC responses to SRBC and R36a. I. TRF is distinct from IL 2 but indistinguishable from polyclonal BCSF.

    PubMed

    Eisenberg, L; Prystowsky, M B; Dick, R F; Sosman, J A; Fitch, F W; Quintáns, J

    1984-03-01

    In vitro PFC responses to the thymus-independent (TI) antigen Streptococcus pneumoniae R36a require T cell replacing factor(s) (TRF). This requirement for TRF is as significant as for the thymus-dependent (TD) antigen SRBC. TRF is shown to be distinct from IL 2 by the following observations: 1) culture supernatants from the cloned T cell line L2, collected over an 8-day period after allogeneic stimulation, transiently contain IL 2 activity but maintain high levels of TRF activity throughout 192 hr; 2) L2V, a variant subclone of L2, produces much higher levels of TRF activity than the parental line but no detectable IL 2 activity; 3) the addition of IL2+, TRF- supernatants from the T cell hybridoma FS6-14.13 does not affect the L2V SF-driven PFC responses to R36a or SRBC; and 4) the addition of contaminating T cells to cultures containing T cell-depleted spleen cells, L2V SF, and antigen does not affect the PFC response. TRF does appear to be indistinguishable from polyclonal B cell stimulating factor (BCSF), which stimulates polyclonal PFC responses in the absence of antigen, mitogen, or anti-Ig. The TRF and BCSF activities of L2V SF could not be separated by ion-exchange, hydrophobic-interaction, and gel-filtration chromatography. TRF and BCSF have an apparent m.w. of approximately 40,000.

  7. Indistinguishable Landscapes of Meiotic DNA Breaks in rad50+ and rad50S Strains of Fission Yeast Revealed by a Novel rad50+ Recombination Intermediate

    PubMed Central

    Hyppa, Randy W.; Cromie, Gareth A.; Smith, Gerald R.

    2008-01-01

    The fission yeast Schizosaccharomyces pombe Rec12 protein, the homolog of Spo11 in other organisms, initiates meiotic recombination by creating DNA double-strand breaks (DSBs) and becoming covalently linked to the DNA ends of the break. This protein–DNA linkage has previously been detected only in mutants such as rad50S in which break repair is impeded and DSBs accumulate. In the budding yeast Saccharomyces cerevisiae, the DSB distribution in a rad50S mutant is markedly different from that in wild-type (RAD50) meiosis, and it was suggested that this might also be true for other organisms. Here, we show that we can detect Rec12-DNA linkages in Sc. pombe rad50+ cells, which are proficient for DSB repair. In contrast to the results from Sa. cerevisiae, genome-wide microarray analysis of Rec12-DNA reveals indistinguishable meiotic DSB distributions in rad50+ and rad50S strains of Sc. pombe. These results confirm our earlier findings describing the occurrence of widely spaced DSBs primarily in large intergenic regions of DNA and demonstrate the relevance and usefulness of fission yeast studies employing rad50S. We propose that the differential behavior of rad50S strains reflects a major difference in DSB regulation between the two species—specifically, the requirement for the Rad50-containing complex for DSB formation in budding yeast but not in fission yeast. Use of rad50S and related mutations may be a useful method for DSB analysis in other species. PMID:19023408

  8. Human and Swine Hosts Share Vancomycin-Resistant Enterococcus faecium CC17 and CC5 and Enterococcus faecalis CC2 Clonal Clusters Harboring Tn1546 on Indistinguishable Plasmids▿†

    PubMed Central

    Freitas, Ana R.; Coque, Teresa M.; Novais, Carla; Hammerum, Anette M.; Lester, Camilla H.; Zervos, Marcus J.; Donabedian, Susan; Jensen, Lars B.; Francia, Maria Victoria; Baquero, Fernando; Peixe, Luísa

    2011-01-01

    VRE isolates from pigs (n = 29) and healthy persons (n = 12) recovered during wide surveillance studies performed in Portugal, Denmark, Spain, Switzerland, and the United States (1995 to 2008) were compared with outbreak/prevalent VRE clinical strains (n = 190; 23 countries; 1986 to 2009). Thirty clonally related Enterococcus faecium clonal complex 5 (CC5) isolates (17 sequence type 6 [ST6], 6 ST5, 5 ST185, 1 ST147, and 1 ST493) were obtained from feces of swine and healthy humans. This collection included isolates widespread among pigs of European Union (EU) countries since the mid-1990s. Each ST comprised isolates showing similar pulsed-field gel electrophoresis (PFGE) patterns (≤6 bands difference; >82% similarity). Some CC5 PFGE subtype strains from swine were indistinguishable from hospital vancomycin-resistant enterococci (VRE) causing infections. A truncated variant of Tn1546 (encoding resistance to vancomycin) and tcrB (coding for resistance to copper) were consistently located on 150- to 190-kb plasmids (reppLG1). E. faecium CC17 (ST132) isolates from pig manure and two clinical samples showed identical PFGE profiles and contained a 60-kb mosaic plasmid (repInc18 plus reppRUM) carrying diverse Tn1546-IS1216 variants. The only Enterococcus faecalis isolate obtained from pigs (CC2-ST6) corresponded to a multidrug-resistant clone widely disseminated in hospitals in Italy, Portugal, and Spain, and both animal and human isolates harbored an indistinguishable 100-kb mosaic plasmid (reppRE25 plus reppCF10) containing the whole Tn1546 backbone. The results indicate a current intra- and international spread of E. faecium and E. faecalis clones and their plasmids among swine and humans. PMID:21227995

  9. Morphological and cytogenetic assessment of cleavage and blastocyst stage embryos.

    PubMed

    Fragouli, E; Alfarawati, S; Spath, K; Wells, D

    2014-02-01

    Morphological assessments are the main way in which fertility clinics select in vitro generated embryo(s) for transfer to the uterus. However, it is widely acknowledged that the microscopic appearance of an embryo is only weakly correlated with its viability. Furthermore, the extent to which morphology is affected by aneuploidy, a genetic defect common in human preimplantation embryos, remains unclear. Aneuploidy is of great relevance to embryo selection as it represents one of the most important causes of implantation failure and miscarriage. The current study aimed to examine whether morphological appearance can assist in identifying embryos at risk of aneuploidy. Additionally, the data produced sheds light on how chromosomal anomalies impact development from the cleavage to the blastocyst stage. A total of 1213 embryos were examined. Comprehensive chromosome analysis was combined with well-established criteria for the assessment of embryo morphology. At the cleavage stage, chromosome abnormalities were common even amongst embryos assigned the best morphological scores, indicating that aneuploidy has little effect on microscopic appearance at fixed time points up until Day 3 of development. However, at the blastocyst stage aneuploidies were found to be significantly less common among embryos of optimal morphological quality, while such abnormalities were overrepresented amongst embryos considered to be of poor morphology. Despite the link between aneuploidy and blastocyst appearance, many chromosomally abnormal embryos were able to achieve the highest morphological scores. In particular, blastocysts affected by forms of aneuploidy with the greatest capacity to produce clinical pregnancies (e.g. trisomy 21) were indistinguishable from euploid embryos. The sex ratio was seen to be equal throughout preimplantation development. Interestingly, however, females were overrepresented amongst the fastest growing cleavage-stage embryos, whereas a sex-related skew in the

  10. Active Sensing System with In Situ Adjustable Sensor Morphology

    PubMed Central

    Nurzaman, Surya G.; Culha, Utku; Brodbeck, Luzius; Wang, Liyu; Iida, Fumiya

    2013-01-01

    Background Despite the widespread use of sensors in engineering systems like robots and automation systems, the common paradigm is to have fixed sensor morphology tailored to fulfill a specific application. On the other hand, robotic systems are expected to operate in ever more uncertain environments. In order to cope with the challenge, it is worthy of note that biological systems show the importance of suitable sensor morphology and active sensing capability to handle different kinds of sensing tasks with particular requirements. Methodology This paper presents a robotics active sensing system which is able to adjust its sensor morphology in situ in order to sense different physical quantities with desirable sensing characteristics. The approach taken is to use thermoplastic adhesive material, i.e. Hot Melt Adhesive (HMA). It will be shown that the thermoplastic and thermoadhesive nature of HMA enables the system to repeatedly fabricate, attach and detach mechanical structures with a variety of shape and size to the robot end effector for sensing purposes. Via active sensing capability, the robotic system utilizes the structure to physically probe an unknown target object with suitable motion and transduce the arising physical stimuli into information usable by a camera as its only built-in sensor. Conclusions/Significance The efficacy of the proposed system is verified based on two results. Firstly, it is confirmed that suitable sensor morphology and active sensing capability enables the system to sense different physical quantities, i.e. softness and temperature, with desirable sensing characteristics. Secondly, given tasks of discriminating two visually indistinguishable objects with respect to softness and temperature, it is confirmed that the proposed robotic system is able to autonomously accomplish them. The way the results motivate new research directions which focus on in situ adjustment of sensor morphology will also be discussed. PMID:24416094

  11. Cytosolic free Ca2+ oscillations induced by diadenosine 5',5"'-P1,P3-triphosphate and diadenosine 5',5"'-P1,P4-tetraphosphate in single rat hepatocytes are indistinguishable from those induced by ADP and ATP respectively.

    PubMed

    Green, A K; Cobbold, P H; Dixon, C J

    1995-09-01

    Diadenosine 5',5"'-P1,P3-triphosphate (Ap3A) and diadenosine 5',5"'-P1,P4-tetraphosphate (Ap4A) induce distinctive patterns of [Ca2+]i oscillations in single rat hepatocytes. We show here that [Ca2+]i oscillations induced by Ap3A and ADP are indistinguishable and that [Ca2+]i oscillations induced by Ap4A closely resemble those induced by ATP. These similarities embrace the following: (1) ADP and Ap3A invariably induce [Ca2+]i transients of short duration (approx. 9 s). Ap4A, like ATP, can induce, depending upon the individual cell, either transients of short duration (approx. 9 s), transients of much longer duration or a mixture of short and long transients within a single response. We show here that the pattern of oscillations induced by Ap4A is similar to that induced by ATP in the same hepatocyte. (2) Elevated intracellular cyclic AMP concentration modulates Ap3A-induced transients, like ADP-induced transients, through an increase in both the peak [Ca2+]i and the frequency of the transients. In contrast, Ap4A-induced transients, like ATP-induced transients, develop an increased duration or a sustained rise in [Ca2+]i, with no rise in peak [Ca2+]i. (3) Ap3A-induced transients, like ADP-induced transients, are abolished by low concentrations of the phorbol ester 4 beta-phorbol 12,13-dibutyrate (PDB; 5-10 nM), whereas long Ap4A-induced transients, like long ATP-induced transients, are refractory to high concentrations of PDB (100 nM). We propose that the [Ca2+]i oscillations induced in rat hepatocytes by Ap3A are mediated by the same purinoceptor that mediates the effects of ADP, whereas the oscillations induced by Ap4A are mediated by the same purinoceptor(s) that mediate the effects of ATP.

  12. Volcanology and morphology

    NASA Technical Reports Server (NTRS)

    Bryan, W. B.

    1976-01-01

    Apollo 15 photographs of the southern parts of Serenitatis and Imbrium were used for a study of the morphology and distribution of wrinkle ridges. Volcanic and structural features along the south margin of Serenitatis were also studied, including the Dawes basalt cinder cones. Volcanic and structural features in crater Aitken were investigated as well. Study of crater Goclenius showed a close relationship between morphology of the impact crater and grabens which tend to parallel directions of the lunar grid. Similar trends were observed in the walls of crater Tsiolkovsky and other linear structures. Small craters of possible volcanic origin were also studied. Possible cinder cones were found associated with the Dawes basalt and in the floor of craters Aitken and Goclenius. Small pit craters were observed in the floors of these craters. Attempts were made to obtain contour maps of specific small features and to compare Orbiter and Apollo photographs to determine short term changes associated with other processes.

  13. Cryptic diversity of the 'cosmopolitan' harpacticoid copepod Nannopus palustris: genetic and morphological evidence.

    PubMed

    Garlitska, Lesya; Neretina, Tatyana; Schepetov, Dimitry; Mugue, Nikolai; De Troch, Marleen; Baguley, Jeffrey G; Azovsky, Andrey

    2012-11-01

    Nannopus palustris Brady, 1880 is a free-living widely distributed harpacticoid copepod, which has been formerly assumed to be a single, cosmopolitan but highly variable species. We compared several geographically distant N. palustris populations in terms of their morphology and genetics. Populations from the White Sea (WS), the North Sea (NS), the Black Sea (BS) and two sympatric morphs from South Carolina, USA (SC notched and SC straight morphs), were considered. The NS, BS and to a lesser extent SC notched specimens were morphologically similar and partly coincided to the 'canonical' description of the species. By contrast, WS population showed remarkable anatomical and morphometric peculiarities that correspond to some earlier descriptions. Genetic analyses of mitochondrial (cytochrome b) and nuclear (28S rDNA) genes demonstrated the significant distinctness among WS, both SC and (NS+BS) populations, the latter two being genetically indistinguishable. Concordance between mitochondrial and nuclear gene trees and morphological data supports that N. palustris is in fact composed of several pseudo-sibling species, which are genetically and morphologically divergent. Neither correlation between genetic divergence and geographical distance nor significant intrapopulation diversity was found for these species. Taxonomic status, distribution and phylogenetic relationships of the species within the Nannopus genus need to be reconsidered. A further subdivision of species complexes might have important implications for the analysis of biodiversity of benthic copepods and consequently for the interpretation of their (species-specific) ecological function.

  14. Effect of Surface Morphology on Adhesion of Graphene

    NASA Astrophysics Data System (ADS)

    Lee, Changgu; Cho, Dae-Hyun; Kim, Jin-Seon; Jin, Taiyu; Kang, Jinyoung; Liu, Renlong; Kim, Youngchan; Wang, Lei; Lee, Gwan-Hyoung; Hone, James

    2013-03-01

    The friction of graphene on various substrates, such as SiO2, h-BN, graphite, and mica, was investigated to characterize the adhesion level between graphene and the underlying surface. The friction of graphene on SiO2 decreased with increasing thickness and converged around the penta-layers due to incomplete contact between the two surfaces. However, the friction of graphene on an atomically flat substrate, such as h-BN and graphite, was low and comparable to that of bulk-like graphene. In contrast, the friction of graphene folded onto graphite was indistinguishable with that of mono-layer graphene on SiO2 despite the ultra-smoothness of the graphite. The characterization of the graphene's roughness before and after folding showed that the corrugation of graphene induced by SiO2 morphology was preserved even after it was folded onto an atomically flat substrate. In addition, graphene deposited on mica, when folded, preserved the same corrugation level as before the folding event. We found that graphene, once exfoliated from the bulk crystal, tends to maintain its corrugation level even after it is folded onto an atomically flat substrate and that ultraflatness in both graphene and the substrate is required to achieve the intimate contact necessary for strong adhesion. School of Mechanical Engineering, SKKU Advanced Institute of Nanotechnology

  15. Evolutionary history of "early-diverging" eukaryotes: the excavate taxon Carpediemonas is a close relative of Giardia.

    PubMed

    Simpson, Alastair G B; Roger, Andrew J; Silberman, Jeffrey D; Leipe, Detlef D; Edgcomb, Virginia P; Jermiin, Lars S; Patterson, David J; Sogin, Mitchell L

    2002-10-01

    Diplomonads, such as Giardia, and their close relatives retortamonads have been proposed as early-branching eukaryotes that diverged before the acquisition-retention of mitochondria, and they have become key organisms in attempts to understand the evolution of eukaryotic cells. In this phylogenetic study we focus on a series of eukaryotes suggested to be relatives of diplomonads on morphological grounds, the "excavate taxa". Phylogenies of small subunit ribosomal RNA (SSU rRNA) genes, alpha-tubulin, beta-tubulin, and combined alpha- + beta-tubulin all scatter the various excavate taxa across the diversity of eukaryotes. But all phylogenies place the excavate taxon Carpediemonas as the closest relative of diplomonads (and, where data are available, retortamonads). This novel relationship is recovered across phylogenetic methods and across various taxon-deletion experiments. Statistical support is strongest under maximum-likelihood (ML) (when among-site rate variation is modeled) and when the most divergent diplomonad sequences are excluded, suggesting a true relationship rather than an artifact of long-branch attraction. When all diplomonads are excluded, our ML SSU rRNA tree actually places retortamonads and Carpediemonas away from the base of the eukaryotes. The branches separating excavate taxa are mostly not well supported (especially in analyses of SSU rRNA data). Statistical tests of the SSU rRNA data, including an "expected likelihood weights" approach, do not reject trees where excavate taxa are constrained to be a clade (with or without parabasalids and Euglenozoa). Although diplomonads and retortamonads lack any mitochondria-like organelle, Carpediemonas contains double membrane-bounded structures physically resembling hydrogenosomes. The phylogenetic position of Carpediemonas suggests that it will be valuable in interpreting the evolutionary significance of many molecular and cellular peculiarities of diplomonads.

  16. The Digital Morphological Sampling Theorem

    NASA Astrophysics Data System (ADS)

    Haralick, Robert M.; Zhuang, Xinhua; Lin, Charlotte; Lee, James

    1988-02-01

    There are potential industrial applications for any methodology which inherently reduces processing time and cost and yet produces results sufficiently close to the result of full processing. It is for this reason that a morphological sampling theorem is important. The morphological sampling theorem described in this paper states: (1) how a digital image must be morphologically filtered before sampling in order to preserve the relevant information after sampling; (2) to what precision an appropriately morphologically filtered image can be reconstructed after sampling; and (3) the relationship between morphologically operating before sampling and the more computationally efficient scheme of morphologically operating on the sampled image with a sampled structuring element. The digital sampling theorem is developed first for the case of binary morphology and then it is extended to gray scale morphology through the use of the umbra homomorphism theorems.

  17. 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

  18. 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.

  19. Investigation of morphology, structure and composition of biomass-oil soot particles

    NASA Astrophysics Data System (ADS)

    Hu, Enzhu; Hu, Xianguo; Liu, Tianxia; Liu, Yiming; Song, Ruhong; Chen, Yazhou

    2013-04-01

    Biomass-oil soot (BS) particles were characterized by a range of analytical techniques. A comparative analysis with commercial carbon black (CB), a surrogate for diesel soot particles, was carried out. The experimental results showed that the morphologies of BS and CB particles were both spherical, with average diameters of 50 and 40 nm, respectively. There were only a few differences between the elemental composition of BS and CB. The groups (Cdbnd O, Osbnd Csbnd O and Csbnd Osbnd C) were presented on the surfaces of CB and BS. Moreover, it was also found that Csbnd OH group was appeared on the surface of BS. BS contained more acidic and basic sites than CB, which was ascribed to the complex mixtures of biomass oil. Both BS and CB had virtually indistinguishable perturbed graphitic or turbostratic internal structures. Thus, CB can be a potential alternative to evaluate the aggregation and tribological behavior of BS in lubricating oils.

  20. Morphology of Proeutectoid Ferrite

    NASA Astrophysics Data System (ADS)

    Yin, Jiaqing; Hillert, Mats; Borgenstam, Annika

    2017-01-01

    The morphology of grain boundary nucleated ferrite particles in iron alloys with 0.3 mass pct carbon has been classified according to the presence of facets. Several kinds of particles extend into both grains of austenite and have facets to both. It is proposed that they all belong to a continuous series of shapes. Ferrite plates can nucleate directly on the grain boundary but can also develop from edges on many kinds of particles. Feathery structures of parallel plates on both sides of a grain boundary can thus form. In sections, parallel to their main growth direction, plates have been seen to extend the whole way from the nucleation site at the grain boundary and to the growth front. This happens in the whole temperature range studied from 973 K to 673 K (700 °C to 400 °C). The plates thus grow continuously and not by subunits stopping at limited length and continuing the growth by new ones nucleating. Sometimes, the plates have ridges and in oblique sections they could be mistaken for the start of new plates. No morphological signs were observed indicating a transition between Widmanstätten ferrite and bainitic ferrite. It is proposed that there is only one kind of acicular ferrite.

  1. Morphology of Proeutectoid Ferrite

    NASA Astrophysics Data System (ADS)

    Yin, Jiaqing; Hillert, Mats; Borgenstam, Annika

    2017-03-01

    The morphology of grain boundary nucleated ferrite particles in iron alloys with 0.3 mass pct carbon has been classified according to the presence of facets. Several kinds of particles extend into both grains of austenite and have facets to both. It is proposed that they all belong to a continuous series of shapes. Ferrite plates can nucleate directly on the grain boundary but can also develop from edges on many kinds of particles. Feathery structures of parallel plates on both sides of a grain boundary can thus form. In sections, parallel to their main growth direction, plates have been seen to extend the whole way from the nucleation site at the grain boundary and to the growth front. This happens in the whole temperature range studied from 973 K to 673 K (700 °C to 400 °C). The plates thus grow continuously and not by subunits stopping at limited length and continuing the growth by new ones nucleating. Sometimes, the plates have ridges and in oblique sections they could be mistaken for the start of new plates. No morphological signs were observed indicating a transition between Widmanstätten ferrite and bainitic ferrite. It is proposed that there is only one kind of acicular ferrite.

  2. Morphological variation of genetically confirmed Alouatta Pigra × A. palliata hybrids from a natural hybrid zone in Tabasco, Mexico.

    PubMed

    Kelaita, Mary A; Cortés-Ortiz, Liliana

    2013-02-01

    While hybridization has been reported for a large number of primate taxa, there is a general lack of data on hybrid morphology for wild individuals with known genetic ancestry. A confirmed hybrid zone for the closely related Neotropical primates Alouatta palliata and A. pigra has provided a unique opportunity to study primate hybrid morphological variation. Here we used molecular evidence based on mitochondrial, Y-chromosome, and autosomal data to assess hybrid ancestry. We conducted univariate and multivariate statistical comparisons of morphometric data collected from individuals both outside and within the hybrid zone in Tabasco, Mexico. Our results show that of all the hybrids detected (N = 128), only 12% of them were approximately genetically intermediate, and none of them were first generation hybrids. Univariate pairwise comparisons among parental individuals, multigenerational backcrossed hybrids, and intermediate hybrids showed that overall, multigenerational backcrossed hybrids resemble the parental species with which they share most of their alleles. Conversely, intermediates were highly variable. Similarly, principal component analysis depicts an overlap between the parental species and their backcrosses when considering overall morphological differences. Finally, discriminant function analysis of the morphological variables was overall unreliable for classifying individuals into their assigned genotypic classes. Taken together, our results suggest that primate natural hybridization studies should incorporate molecular methods for determining ancestry, because morphology may not always be a reliable indicator of hybrid status. Hybrid zones could comprise a large number of multigenerational backcrossed hybrids that are indistinguishable from the parental species. The implications for studying hybridization in the primate fossil record are discussed.

  3. Cryptic diversity in a fig wasp community-morphologically differentiated species are sympatric but cryptic species are parapatric.

    PubMed

    Darwell, C T; Cook, J M

    2017-02-01

    A key debate in ecology centres on the relative importance of niche and neutral processes in determining patterns of community assembly with particular focus on whether ecologically similar species with similar functional traits are able to coexist. Meanwhile, molecular studies are increasingly revealing morphologically indistinguishable cryptic species with presumably similar ecological roles. Determining the geographic distribution of such cryptic species provides opportunities to contrast predictions of niche vs. neutral models. Discovery of sympatric cryptic species increases alpha diversity and supports neutral models, while documentation of allopatric/parapatric cryptic species increases beta diversity and supports niche models. We tested these predictions using morphological and molecular data, coupled with environmental niche modelling analyses, of a fig wasp community along its 2700-km latitudinal range. Molecular methods increased previous species diversity estimates from eight to eleven species, revealing morphologically cryptic species in each of the four wasp genera studied. Congeneric species pairs that were differentiated by a key morphological functional trait (ovipositor length) coexisted sympatrically over large areas. In contrast, morphologically similar species, with similar ovipositor lengths, typically showed parapatric ranges with very little overlap. Despite parapatric ranges, environmental niche models of cryptic congeneric pairs indicate large regions of potential sympatry, suggesting that competitive processes are important in determining the distributions of ecologically similar species. Niche processes appear to structure this insect community, and cryptic diversity may typically contribute mostly to beta rather than alpha diversity.

  4. Morphological and molecular characterization of Cladosporium cladosporioides species complex causing pecan tree leaf spot.

    PubMed

    Walker, C; Muniz, M F B; Rolim, J M; Martins, R R O; Rosenthal, V C; Maciel, C G; Mezzomo, R; Reiniger, L R S

    2016-09-16

    The objective of this study was to characterize species of the Cladosporium cladosporioides complex isolated from pecan trees (Carya illinoinensis) with symptoms of leaf spot, based on morphological and molecular approaches. Morphological attributes were assessed using monosporic cultures on potato dextrose agar medium, which were examined for mycelial growth, sporulation, color, and conidia and ramoconidia size. Molecular characterization comprised isolation of DNA and subsequent amplification of the translation elongation factor 1α (TEF-1α) region. Three species of the C. cladosporioides complex were identified: C. cladosporioides, Cladosporium pseudocladosporioides, and Cladosporium subuliforme. Sporulation was the most important characteristic differentiating species of this genus. However, morphological features must be considered together with molecular analysis, as certain characters are indistinguishable between species. TEF-1αcan be effectively used to identify and group isolates belonging to the C. cladosporioides complex. The present study provides an important example of a methodology to ascertain similarity between isolates of this complex causing leaf spot in pecan trees, which should facilitate future pathogenicity studies.

  5. Interpreting dissociations between regular and irregular past-tense morphology: Evidence from event-related potentials

    PubMed Central

    Justus, Timothy; Larsen, Jary; de Mornay Davies, Paul; Swick, Diane

    2009-01-01

    Neuropsychological dissociations between regular and irregular English past-tense morphology have been reported using a lexical-decision task in which past-tense primes immediately precede present-tense targets. We present N400 event-related potential data from healthy participants using the same design. Both regular and irregular past-tense forms primed corresponding present-tense forms, but with a longer duration for irregular verbs. Phonological control conditions suggested that differences in formal overlap between prime and target contributes to, but does not account for this difference, suggesting a link between irregular morphology and semantics. Further analysis, dividing the irregular verbs into two categories (weak irregular and strong) revealed that priming for strong verbs was reliably stronger than that for weak irregular and regular verbs, which were statistically indistinguishable from one another. We argue that although we observe a regular-irregular dissociation, the nature of this dissociation is more consistent with single- than with dual-system models of inflectional morphology. PMID:18589508

  6. Morphological innovation and developmental genetics.

    PubMed

    Marshall, C R; Orr, H A; Patel, N H

    1999-08-31

    How do the actions of individual genes contribute to the complex morphologies of animals and plants? How widespread are these genes taxonomically? How many genes are involved in the morphological differences observed between species, and can we identify them? To what extent can empirical data and theory be reconciled? We provide an overview of some recent attempts to answer these questions, answers that have taken us to the threshold of understanding the mechanistic basis and evolutionary factors that underlie morphological innovation.

  7. Differentiating morphology, form, and meaning: neural correlates of morphological complexity.

    PubMed

    Bozic, Mirjana; Marslen-Wilson, William D; Stamatakis, Emmanuel A; Davis, Matthew H; Tyler, Lorraine K

    2007-09-01

    The role of morphological structure in word recognition raises issues about the nature and structure of the language system. One major issue is whether morphological factors provide an independent principle for lexical organization and processing, or whether morphological effects can be reduced to the joint contribution of form and meaning. The independence of form, meaning, and morphological structure can be directly investigated using derivationally complex words, because derived words can share form but need not share meaning (e.g., archer-arch). We used an event-related functional magnetic resonance imaging paradigm to investigate priming between pairs of words that potentially shared a stem, where this link was either semantically transparent (e.g., bravely-brave) or opaque (e.g., archer-arch). These morphologically related pairs were contrasted with identity priming (e.g., mist-mist) and priming for pairs of words that shared only form (e.g., scandal-scan) or meaning (e.g., accuse-blame). Morphologically related words produced significantly reduced activation in left frontal regions, whether the pairs were semantically transparent or opaque. The effect was not found for any of the control conditions (identity, form, or meaning). Morphological effects were observed separately from processing form and meaning and we propose that they reflect segmentation of complex derived words, a process triggered by surface morphological structure of complex words.

  8. Morphological Evolution of Asteroids

    NASA Astrophysics Data System (ADS)

    Richardson, D. C.

    2003-08-01

    Recent ground- and space-based observations of asteroids have revealed that these bodies are far more complex than once imagined. Surprisingly low bulk densities, giant craters, unusual shapes, non-principal-axis spin states, and satellites are all challenging our understanding of how asteroids form and evolve. Since asteroids are the remnants of the planet building era, understanding their nature improves our understanding of the origin of solar systems in general. I will review some of the more puzzling aspects of asteroid morphology, including the existence of asteroid satellites, and discuss recent theoretical advances aimed at understanding our tiny neighbors. I will show that both theoretical and observational evidence is pointing increasingly to asteroids being fragile assemblages of smaller pieces, called gravitational aggregates. The consequences of such fragmented internal structure on asteroid evolution and hazard mitigation will be discussed. This work has been supported in part by the National Aeronautics and Space Administration under Contract No. NAG511722 issued through the Office of Space Science.

  9. Fish Manoeuvres and Morphology

    NASA Astrophysics Data System (ADS)

    Singh, Kiran; Pedley, Timothy

    2008-11-01

    The extraordinary manoeuvrability observed in many fish is attributed to their inherent flexibility, which might be enhanced by the use of appendages like fins. The aim of this work is to understand the role of morphological adaptations, such as body shape and deployment of median fins, on manoeuvrability and internal body dynamics. The 3d vortex lattice numerical method was employed to analyse the hydrodynamics for arbitrary body planforms of infinitesimal thickness. The internal structure of the body due to the combined skeletal system and soft tissue, is represented as an active Euler-Bernoulli beam, in which the time-dependent bending moment distribution is calculated from body inertia and the hydrodynamic pressure difference across the body. C-turns are the manoeuvre of choice for this work and the response for three different species of fish are examined. Angelfish(Pterophyllum eimekei), pike (Esox sp) and tuna (Thunnus albacares) were chosen for their differences in body profile, median fin use and manoeuvrability. Net direction change and bending moment response to prescribed backbone flexure are calculated and used to interpret the influence of body profile on manoeuvrability and muscle work done. Internal stresses may be computed from anatomical data on muscle fibre distribution and recruitment. To the future, it is intended to extend this work to other typical manoeuvres, such as fast starts for which muscle activation patterns have been measured quite widely.

  10. Engineering Crystal Morphology

    NASA Astrophysics Data System (ADS)

    Dandekar, Preshit; Kuvadia, Zubin B.; Doherty, Michael F.

    2013-07-01

    Crystallization is an important separation and particle formation technique in the manufacture of high-value-added products. During crystallization, many physicochemical characteristics of the substance are established. Such characteristics include crystal polymorph, shape and size, chemical purity and stability, reactivity, and electrical and magnetic properties. However, control over the physical form of crystalline materials has remained poor, due mainly to an inadequate understanding of the basic growth and dissolution mechanisms, as well as of the influence of impurities, additives, and solvents on the growth rate of individual crystal faces. Crystal growth is a surface-controlled phenomenon in which solute molecules are incorporated into surface lattice sites to yield the bulk long-range order that characterizes crystalline materials. In this article, we describe some recent advances in crystal morphology engineering, with a special focus on a new mechanistic model for spiral growth. These mechanistic ideas are simple enough that they can be made to work and accurate enough that they are useful.

  11. Hip Morphology Characterization

    PubMed Central

    Barrientos, Cristián; Diaz, Jorge; Brañes, Julian; Chaparro, Felipe; Barahona, Maximiliano; Salazar, Alfonso; Hinzpeter, Jaime

    2014-01-01

    Background: Femoroacetabular impingement (FAI) is the result of a mechanical conflict in the hip joint, and its diagnosis is based on clinical and radiological parameters. To our knowledge, there are no published studies describing the radiologic characteristics of FAI in Latin American populations. Purpose: To describe the radiological features associated with FAI in an asymptomatic Chilean population. Study Design: Cross-sectional study; Level of evidence, 3. Methods: We prospectively recruited asymptomatic patients with no history or symptoms of hip pathology who underwent abdomen-pelvis computed tomography (CT) for a nonorthopaedic indication. The acetabular and femoral parameters related to FAI were measured. Results: We studied 101 subjects (202 hips) with a mean age of 36.8 ± 14.4 years. The mean center-edge angle was 39.4° ± 7.2°. The crossover sign was present in 34 cases (33.7%). The mean alpha angle was 49.7° ± 8.3°. Depending on the cut points chosen for FAI-related parameters, between 39.6% and 69.3% of an asymptomatic Chilean population were found to have morphological features related to FAI. Conclusion: Our findings suggest that the proposed pathological threshold values in the literature cannot be extrapolated to a Chilean population, and this must be taken into consideration when evaluating Latin American patients with hip pain. PMID:26535273

  12. Morphological Processing in Adult Dyslexia

    ERIC Educational Resources Information Center

    Leikin, Mark; Hagit, Even Zur

    2006-01-01

    This study employed the masked-priming paradigm [Forster and Davis (J Exp Psychol bearn Mem Cogn 10: 680-698, 1984).], along with traditional methods of evaluation of morphological awareness and phonological processing, to obtain a finer-grained picture of the relationship between morphological abilities and reading in adult dyslexic readers.…

  13. Differential morphology and image processing.

    PubMed

    Maragos, P

    1996-01-01

    Image processing via mathematical morphology has traditionally used geometry to intuitively understand morphological signal operators and set or lattice algebra to analyze them in the space domain. We provide a unified view and analytic tools for morphological image processing that is based on ideas from differential calculus and dynamical systems. This includes ideas on using partial differential or difference equations (PDEs) to model distance propagation or nonlinear multiscale processes in images. We briefly review some nonlinear difference equations that implement discrete distance transforms and relate them to numerical solutions of the eikonal equation of optics. We also review some nonlinear PDEs that model the evolution of multiscale morphological operators and use morphological derivatives. Among the new ideas presented, we develop some general 2-D max/min-sum difference equations that model the space dynamics of 2-D morphological systems (including the distance computations) and some nonlinear signal transforms, called slope transforms, that can analyze these systems in a transform domain in ways conceptually similar to the application of Fourier transforms to linear systems. Thus, distance transforms are shown to be bandpass slope filters. We view the analysis of the multiscale morphological PDEs and of the eikonal PDE solved via weighted distance transforms as a unified area in nonlinear image processing, which we call differential morphology, and briefly discuss its potential applications to image processing and computer vision.

  14. Tense Aspect in Verbal Morphology.

    ERIC Educational Resources Information Center

    Salaberry, Rafael

    2003-01-01

    Analyzed the development of past tense verbal morphology in Spanish second language acquisition among native English speakers divided into three levels of proficiency. Analysis shows that learners may use a default marker of past tense during the beginning stages of development of verbal morphology, but the choice of the default may be dependent…

  15. Morphological Awareness in Developmental Dyslexia

    ERIC Educational Resources Information Center

    Casalis, Severine; Cole, Pascale; Sopo, Delphine

    2004-01-01

    This study examines morphological awareness in developmental dyslexia. While the poor phonological awareness of dyslexic children has been related to their difficulty in handling the alphabetical principle, less is known about their morphological awareness, which also plays an important part in reading development. The aim of this study was to…

  16. Morphological Dynamics in Compound Processing

    ERIC Educational Resources Information Center

    Kuperman, Victor; Bertram, Raymond; Baayen, R. Harald

    2008-01-01

    This paper explores the time-course of morphological processing of trimorphemic Finnish compounds. We find evidence for the parallel access to full-forms and morphological constituents diagnosed by the early effects of compound frequency, as well as early effects of left constituent frequency and family size. We also observe an interaction between…

  17. Unraveling a 70-year-old taxonomic puzzle: redefining the genus ikedosoma (annelida: echiura) on the basis of morphological and molecular analyses.

    PubMed

    Tanaka, Masaatsu; Kon, Takeshi; Nishikawa, Teruaki

    2014-12-01

    After a long-standing taxonomic confusion, the echiurid genus Ikedosoma Bock, 1942 , endemic to Japan and surroundings, is redefined on the basis of morphological and molecular analyses of many new Japanese materials and some museum specimens. The re-examination of a syntype of I. elegans ( Ikeda, 1904 ), the type species of the genus, first revealed that its oblique muscle layer is continuous throughout and never fasciculate between longitudinal muscle bands, unlike those described in the definitions that have prevailed for ca. 70 years, making this genus indistinguishable from Listriolobus Spengel, 1912 . Two Japanese species of Ikedosoma, I. elegans and I. gogoshimense (Ikeda, 1904), which were thus redefined, had also been poorly defined in the past to the point of being nearly indistinguishable from each other, largely due to incomplete descriptions and poor collections. Molecular phylogenetic analyses using 18S and 28S ribosomal RNA, histone H3, and cytochrome c oxidase subunit I (COI) genes clearly confirmed the distinction between these two species, their monophyletic origin, and their distinction from L. sorbillans (Lampert, 1883). The genus Ikedosoma thus validated is morphologically distinguishable from Listriolobus by the absence of a rectal caecum. Ikedosoma elegans and I. gogoshimense also differ in the disposition of gonoduct pairs. The third known species, I. qingdaoense Li, Wang and Zhou, 1994 , from Qingdao, North China, lacks information on oblique muscle layers, which makes even its generic affiliation uncertain.

  18. Morphological measurements and ITS sequences show that the new alder rust in Europe is conspecific with Melampsoridium hiratsukanum in eastern Asia.

    PubMed

    Hantula, J; Kurkela, T; Hendry, S; Yamaguchi, T

    2009-01-01

    Three species of Melampsoridium have been reported to infect hosts in genus Alnus. An epidemic of foliar rust affecting A. glutinosa and A. incana began in Europe in the mid-1990s, and the associated pathogen was identified as Melampsoridium hiratsukanum based on morphology. In this investigation we analyzed the morphology and genetic variation of alder rusts from Europe and Japan and the host specificity of the European epidemic rust. Our results showed that two rusts occur on the leaves of alders native to northern Europe; in Scotland an endemic rust indistinguishable from M. betulinum occurs, whereas alders in areas of Europe affected by the current epidemic were infected by M. hiratsukanum. M. hiratsukanum from naturally infected alder in Finland produced aecia on all Larix species tested but did not infect Betula leaves.

  19. Beyond mathematical morphology (Invited Paper)

    NASA Astrophysics Data System (ADS)

    Ritter, G. X.; Davidson, J. L.; Wilson, J. N.

    1987-10-01

    We present an algebraic structure, known as the AFATL (Air Force Armament Technical Laboratory) Image Algebra, that is capable of expressing all image-to-image transformations. After presenting a brief overview of the operands and operations of the algebra, we show how a subalgebra of the full Image Algebra generalizes the theory of mathematical morphology. We provide examples which include 1) morphological operations expressed in the algebra, 2) Image Algebra algorithms not expressible in terms of morphological operations, and 3) a fractal target detection algorithm expressed in terms of the Image Algebra.

  20. Mitochondria-derived organelles in the diplomonad fish parasite Spironucleus vortens.

    PubMed

    Millet, Coralie O M; Williams, Catrin F; Hayes, Anthony J; Hann, Anthony C; Cable, Joanne; Lloyd, David

    2013-10-01

    In some eukaryotes, mitochondria have become modified during evolution to yield derived organelles (MDOs) of a similar size (hydrogenosomes), or extremely reduced to produce tiny cellular vesicles (mitosomes). The current study provides evidence for the presence of MDOs in the highly infectious fish pathogen Spironucleus vortens, an organism that produces H₂ and is shown here to have no detectable cytochromes. Transmission electron microscopy (TEM) reveals that S. vortens trophozoites contain electron-dense, membranous structures sometimes with an electron-dense core (200 nm-1 μm), resembling the hydrogenosomes previously described in other protists from habitats deficient in O₂. Confocal microscopy establishes that these organelles exhibit autofluorescence emission spectra similar to flavoprotein constituents previously described for mitochondria and also present in hydrogenosomes. These organelles possess a membrane potential and are labelled by a fluorescently labeled antibody against Fe-hydrogenase from Blastocystis hominis. Heterologous antibodies raised to mitochondrial proteins frataxin and Isu1, also exhibit a discrete punctate pattern of localization in S. vortens; however these labelled structures are distinctly smaller (90-150 nm) than hydrogenosomes as observed previously in other organisms. TEM confirms the presence of double-membrane bounded organelles of this smaller size. In addition, strong background immunostaining occurs in the cytosol for frataxin and Isu1, and labelling by anti-ferredoxin antibody is generally distributed and not specifically localized except for at the anterior polar region. This suggests that some of the functions traditionally attributed to such MDOs may also occur elsewhere. The specialized parasitic life-style of S. vortens may necessitate more complex intracellular compartmentation of redox reactions than previously recognized. Control of infection requires biochemical characterization of redox-related organelles.

  1. Martian deltas: Morphology and distribution

    NASA Technical Reports Server (NTRS)

    Rice, J. W., Jr.; Scott, D. H.

    1993-01-01

    Recent detailed mapping has revealed numerous examples of Martian deltas. The location and morphology of these deltas are described. Factors that contribute to delta morphology are river regime, coastal processes, structural stability, and climate. The largest delta systems on Mars are located near the mouths of Maja, Maumee, Vedra, Ma'adim, Kasei, and Brazos Valles. There are also several smaller-scale deltas emplaced near channel mouths situated in Ismenius Lacus, Memnonia, and Arabia. Delta morphology was used to reconstruct type, quantity, and sediment load size transported by the debouching channel systems. Methods initially developed for terrestrial systems were used to gain information on the relationships between Martian delta morphology, river regime, and coastal processes.

  2. SDSS DR7 superclusters. Morphology

    NASA Astrophysics Data System (ADS)

    Einasto, M.; Liivamägi, L. J.; Tago, E.; Saar, E.; Tempel, E.; Einasto, J.; Martínez, V. J.; Heinämäki, P.

    2011-08-01

    Aims: We study the morphology of a set of superclusters drawn from the SDSS DR7. Methods: We calculate the luminosity density field to determine superclusters from a flux-limited sample of galaxies from SDSS DR7 and select superclusters with 300 and more galaxies for our study. We characterise the morphology of superclusters using the fourth Minkowski functional V3, the morphological signature (the curve in the shapefinder's K1-K2 plane) and the shape parameter (the ratio of the shapefinders K1/K2). We investigate the supercluster sample using multidimensional normal mixture modelling. We use Abell clusters to identify our superclusters with known superclusters and to study the large-scale distribution of superclusters. Results: The superclusters in our sample form three chains of superclusters; one of them is the Sloan Great Wall. Most superclusters have filament-like overall shapes. Superclusters can be divided into two sets; more elongated superclusters are more luminous, richer, have larger diameters and a more complex fine structure than less elongated superclusters. The fine structure of superclusters can be divided into four main morphological types: spiders, multispiders, filaments, and multibranching filaments. We present the 2D and 3D distribution of galaxies and rich groups, the fourth Minkowski functional, and the morphological signature for all superclusters. Conclusions: Widely different morphologies of superclusters show that their evolution has been dissimilar. A study of a larger sample of superclusters from observations and simulations is needed to understand the morphological variety of superclusters and the possible connection between the morphology of superclusters and their large-scale environment.

  3. Sorting of Sperm by Morphology

    NASA Astrophysics Data System (ADS)

    Koh, James; Marcos, Marcos

    2016-11-01

    Many studies have proven that the percentage of morphologically normal sperm is a significant factor in determining the success of assisted reproduction. The velocity of sperm in a microchannel with shear flow subjected to an external field will be explored theoretically. The difference in response between morphologically normal and abnormal sperm will be computed from a statistical approach, to study the feasibility and effectiveness of sorting by an external field to remove abnormal sperm. The full name of this author is Marcos.

  4. The morphology of green hydra endosymbionts as influenced by host strain and host environment.

    PubMed

    Pardy, R L

    1976-05-01

    The ultrastructure of Chlorella-like algal endosymbionts from the Florida and English strains of green hydra was compared under different host feeding and photoperiodic regimes. Under standard conditions (host fed daily, 12-h photoperiod) the algae from the 2 strains exhibited considerable differences. The English symbionts had a pyrenoid, compact chloroplast membranes and vesiculated polyphosphate bodies. By comparison, Florida symbionts lacked a pyrenoid, had chloroplasts with less compact membranes and exhibited spherical polyphosphate bodies. When maintained in the dark, algae from English hydra lost their pyrenoids, showed great compaction of the chloroplast and developed large, shield-shaped, electron-dense bodies. In contrast, algae from Florida hosts did not exhibit gross ultrastructural modification. Reciprocal cross-transfers of symbionts were made by placing Florida algae in English aposymbiotic (algal-free) hosts and vice versa. After residence in Florida hosts, English symbionts appeared to undergo ultrastructural modifications resulting in a morphology indistinguishable from the native Florida symbionts. Florida algae showed no modifications resulting from residence in English hosts. It thus appears that the English symbiont has great morphological plasticity, as its structure is greatly modified depending upon the host in which it resides and the conditions under which the host is maintained. The results of these studies are discussed and compared with published accounts of free-living Chlorella and with reports dealing with other Chlorella symbionts.

  5. Shape-shifting corals: Molecular markers show morphology is evolutionarily plastic in Porites

    PubMed Central

    Forsman, Zac H; Barshis, Daniel J; Hunter, Cynthia L; Toonen, Robert J

    2009-01-01

    Background Corals are notoriously difficult to identify at the species-level due to few diagnostic characters and variable skeletal morphology. This 'coral species problem' is an impediment to understanding the evolution and biodiversity of this important and threatened group of organisms. We examined the evolution of the nuclear ribosomal internal transcribed spacer (ITS) and mitochondrial markers (COI, putative control region) in Porites, one of the most taxonomically challenging and ecologically important genera of reef-building corals. Results Nuclear and mitochondrial markers were congruent, clearly resolving many traditionally recognized species; however, branching and mounding varieties were genetically indistinguishable within at least two clades, and specimens matching the description of 'Porites lutea' sorted into three genetically divergent groups. Corallite-level features were generally concordant with genetic groups, although hyper-variability in one group (Clade I) overlapped and obscured several others, and Synarea (previously thought to be a separate subgenus) was closely related to congeners despite its unique morphology. Scanning electron microscopy revealed subtle differences between genetic groups that may have been overlooked previously as taxonomic characters. Conclusion This study demonstrates that the coral skeleton can be remarkably evolutionarily plastic, which may explain some taxonomic difficulties, and obscure underlying patterns of endemism and diversity. PMID:19239678

  6. Tailoring vessel morphology in vivo

    NASA Astrophysics Data System (ADS)

    Gould, Daniel Joseph

    Tissue engineering is a rapidly growing field which seeks to provide alternatives to organ transplantation in order to address the increasing need for transplantable tissues. One huge hurdle in this effort is the provision of thick tissues; this hurdle exists because currently there is no way to provide prevascularized or rapidly vascularizable scaffolds. To design thick, vascularized tissues, scaffolds are needed that can induce vessels which are similar to the microvasculature found in normal tissues. Angiogenic biomaterials are being developed to provide useful scaffolds to address this problem. In this thesis angiogenic and cell signaling and adhesion factors were incorporated into a biomimetic poly(ethylene glycol) (PEG) hydrogel system. The composition of these hydrogels was precisely tuned to induce the formation of differing vessel morphology. To sensitively measure induced microvascular morphology and to compare it to native microvessels in several tissues, this thesis developed an image-based tool for quantification of scale invariant and classical measures of vessel morphology. The tool displayed great utility in the comparison of native vessels and remodeling vessels in normal tissues. To utilize this tool to tune the vessel response in vivo, Flk1::myr-mCherry fluorescently labeled mice were implanted with Platelet Derived Growth Factor-BB (PDGF-BB) and basic Fibroblast Growth Factor (FGF-2) containing PEG-based hydrogels in a modified mouse corneal angiogenesis assay. Resulting vessels were imaged with confocal microscopy, analyzed with the image based tool created in this thesis to compare morphological differences between treatment groups, and used to create a linear relationship between space filling parameters and dose of growth factor release. Morphological parameters of native mouse tissue vessels were then compared to the linear fit to calculate the dose of growth factors needed to induce vessels similar in morphology to native vessels

  7. Phylogenetic mapping of bacterial morphology

    NASA Technical Reports Server (NTRS)

    Siefert, J. L.; Fox, G. E.

    1998-01-01

    The availability of a meaningful molecular phylogeny for bacteria provides a context for examining the historical significance of various developments in bacterial evolution. Herein, the classical morphological descriptions of selected members of the domain Bacteria are mapped upon the genealogical ancestry deduced from comparison of small-subunit rRNA sequences. For the species examined in this study, a distinct pattern emerges which indicates that the coccus shape has arisen and accumulated independently multiple times in separate lineages and typically survived as a persistent end-state morphology. At least two other morphologies persist but have evolved only once. This study demonstrates that although bacterial morphology is not useful in defining bacterial phylogeny, it is remarkably consistent with that phylogeny once it is known. An examination of the experimental evidence available for morphogenesis as well as microbial fossil evidence corroborates these findings. It is proposed that the accumulation of persistent morphologies is a result of the biophysical properties of peptidoglycan and their genetic control, and that an evolved body-plan strategy based on peptidoglycan may have been a fate-sealing step in the evolution of Bacteria. More generally, this study illustrates that significant evolutionary insights can be obtained by examining biological and biochemical data in the context of a reliable phylogenetic structure.

  8. Opto-electronic morphological processor

    NASA Technical Reports Server (NTRS)

    Yu, Jeffrey W. (Inventor); Chao, Tien-Hsin (Inventor); Cheng, Li J. (Inventor); Psaltis, Demetri (Inventor)

    1993-01-01

    The opto-electronic morphological processor of the present invention is capable of receiving optical inputs and emitting optical outputs. The use of optics allows implementation of parallel input/output, thereby overcoming a major bottleneck in prior art image processing systems. The processor consists of three components, namely, detectors, morphological operators and modulators. The detectors and operators are fabricated on a silicon VLSI chip and implement the optical input and morphological operations. A layer of ferro-electric liquid crystals is integrated with a silicon chip to provide the optical modulation. The implementation of the image processing operators in electronics leads to a wide range of applications and the use of optical connections allows cascadability of these parallel opto-electronic image processing components and high speed operation. Such an opto-electronic morphological processor may be used as the pre-processing stage in an image recognition system. In one example disclosed herein, the optical input/optical output morphological processor of the invention is interfaced with a binary phase-only correlator to produce an image recognition system.

  9. Eruptive viscosity and volcano morphology

    NASA Technical Reports Server (NTRS)

    Posin, Seth B.; Greeley, Ronald

    1988-01-01

    Terrestrial central volcanoes formed predominantly from lava flows were classified as shields, stratovolcanoes, and domes. Shield volcanoes tend to be large in areal extent, have convex slopes, and are characterized by their resemblance to inverted hellenic war shields. Stratovolcanoes have concave slopes, whereas domes are smaller and have gentle convex slopes near the vent that increase near the perimeter. In addition to these differences in morphology, several other variations were observed. The most important is composition: shield volcanoes tend to be basaltic, stratovolcanoes tend to be andesitic, and domes tend to be dacitic. However, important exceptions include Fuji, Pico, Mayon, Izalco, and Fuego which have stratovolcano morphologies but are composed of basaltic lavas. Similarly, Ribkwo is a Kenyan shield volcano composed of trachyte and Suswa and Kilombe are shields composed of phonolite. These exceptions indicate that eruptive conditions, rather than composition, may be the primary factors that determine volcano morphology. The objective of this study is to determine the relationships, if any, between eruptive conditions (viscosity, erupted volume, and effusion rate) and effusive volcano morphology. Moreover, it is the goal of this study to incorporate these relationships into a model to predict the eruptive conditions of extraterrestrial (Martian) volcanoes based on their morphology.

  10. Martian valleys: morphology, distribution, age, and origin.

    PubMed

    Pieri, D C

    1980-11-21

    Branching valley networks throughout the heavily cratered terrain of Mars exhibit no compelling evidence for formation by rainfall-fed erosion. The networks are diffuse and inefficient, with irregular tributary junction angles and large, undissected intervalley areas. Rather, the deeply entrenched canyons, with blunt amphitheater terminations, cliff-bench wall topography, lack of evidence of interior erosion by flow, and clear structural control, suggest headward extension by basal sapping. The size-frequency distributions of impact craters in these valleys and in the heavily cratered terrain that surrounds them are statistically indistinguishable, suggesting that valley formation has not occurred on Mars for billions of years.

  11. Bayesian Inference of Galaxy Morphology

    NASA Astrophysics Data System (ADS)

    Yoon, Ilsang; Weinberg, M.; Katz, N.

    2011-01-01

    Reliable inference on galaxy morphology from quantitative analysis of ensemble galaxy images is challenging but essential ingredient in studying galaxy formation and evolution, utilizing current and forthcoming large scale surveys. To put galaxy image decomposition problem in broader context of statistical inference problem and derive a rigorous statistical confidence levels of the inference, I developed a novel galaxy image decomposition tool, GALPHAT (GALaxy PHotometric ATtributes) that exploits recent developments in Bayesian computation to provide full posterior probability distributions and reliable confidence intervals for all parameters. I will highlight the significant improvements in galaxy image decomposition using GALPHAT, over the conventional model fitting algorithms and introduce the GALPHAT potential to infer the statistical distribution of galaxy morphological structures, using ensemble posteriors of galaxy morphological parameters from the entire galaxy population that one studies.

  12. Ecological Niche Modelling and nDNA Sequencing Support a New, Morphologically Cryptic Beetle Species Unveiled by DNA Barcoding

    PubMed Central

    Hawlitschek, Oliver; Porch, Nick; Hendrich, Lars; Balke, Michael

    2011-01-01

    Background DNA sequencing techniques used to estimate biodiversity, such as DNA barcoding, may reveal cryptic species. However, disagreements between barcoding and morphological data have already led to controversy. Species delimitation should therefore not be based on mtDNA alone. Here, we explore the use of nDNA and bioclimatic modelling in a new species of aquatic beetle revealed by mtDNA sequence data. Methodology/Principal Findings The aquatic beetle fauna of Australia is characterised by high degrees of endemism, including local radiations such as the genus Antiporus. Antiporus femoralis was previously considered to exist in two disjunct, but morphologically indistinguishable populations in south-western and south-eastern Australia. We constructed a phylogeny of Antiporus and detected a deep split between these populations. Diagnostic characters from the highly variable nuclear protein encoding arginine kinase gene confirmed the presence of two isolated populations. We then used ecological niche modelling to examine the climatic niche characteristics of the two populations. All results support the status of the two populations as distinct species. We describe the south-western species as Antiporus occidentalis sp.n. Conclusion/Significance In addition to nDNA sequence data and extended use of mitochondrial sequences, ecological niche modelling has great potential for delineating morphologically cryptic species. PMID:21347370

  13. Geometric morphology of granular materials

    NASA Astrophysics Data System (ADS)

    Schlei, Bernd R.; Prasad, Lakshman; Skourikhine, Alexei N.

    2000-10-01

    We present a new method to transform the spectral pixel information of a micrograph into an affine geometric description, which allows us to analyze the morphology of granular materials. We use spectral and pulse-coupled neural network based segmentation techniques to generate blobs, and a newly developed algorithm to extract dilated contours. A constrained Delaunay tessellation of the contour points results in a triangular mesh. This mesh is the basic ingredient of the Chodal Axis Transform, which provides a morphological decomposition of shapes. Such decomposition allows for grain separation and the efficient computation of the statistical features of granular materials.

  14. Morphological Galaxy Classification with Shapelets

    NASA Astrophysics Data System (ADS)

    Andrae, René; Melchior, Peter

    2008-12-01

    We present an unsupervised classification algorithm, that identifies natural classes of galaxy morphologies. Working on SDSS G-band imaging data, we encode the morphologies by shapelet decomposition. The algorithm employs a model-based soft clustering analysis to find groupings of similar data points. We demonstrate that the algorithm is able to clearly identify and distinguish groups of elliptical, face-on and edge-on spiral galaxies in a training data set. Based on the soft clustering results, we set up a soft classifier for a data set containing 1602 SDSS galaxies.

  15. Children's Morphological Awareness and Reading Ability

    ERIC Educational Resources Information Center

    Kirby, John R.; Deacon, S. Helene; Bowers, Peter N.; Izenberg, Leah; Wade-Woolley, Lesly; Parrila, Rauno

    2012-01-01

    We investigated the effects of morphological awareness on five measures of reading in 103 children from Grades 1 to 3. Morphological awareness was assessed with a word analogy task that included a wide range of morphological transformations. Results indicated that the new measure had satisfactory reliability, and that morphological awareness was a…

  16. Quantitative Flow Morphology, Recent Volcanic Evolution and Future Activity of the Kameni Islands, Santorini, Greece

    NASA Astrophysics Data System (ADS)

    Elliott, J. R.; Pyle, D. M.

    2005-12-01

    The fundamental importance of careful field investigation, and the long term value of detailed published volcanic eruption reports, means that much can be learned about eruption processes even many decades after an eruption has ceased. We illustrate this with reference to the young dacite lava flows of the Kameni islands, Santorini. We have created a new, high resolution digital elevation model (DEM) for the intra-caldera Kameni islands, Santorini, based on new data from a recent airborne laser-ranging (LiDAR) and aerial photography mission. This DEM reveals a wealth of surface morphological information on the dacite lava flows that comprise the Kameni islands. When combined with a re-analysis of contemporary eruption accounts, these data yield important insights into the physical properties and flow behaviour of dacite magma during slow effusive eruptions. Kameni island lava flows exhibit the classic surface morphologies associated with viscous aa: levees, and compression folds. Levee heights and flow widths are consistent with a Bingham rheology, and lava yield strengths of (3 to 7)× 104 Pa. Analysis of the shapes of flow edges confirms that the blocky aa dacite lava flows show a scale-invariant morphology with a typical fractal dimension that is indistinguishable from Hawaiian aa. Dome-growth rates during eruptions of the Kameni islands in 1866 and 1939 are consistent with a model of slow inflation of a dome with a strong crust. Lava domes on the Kameni islands have a crustal yield strength (4×107 Pa) that is lower by a factor of 2 to 4 than the domes at Pinatubo and Mount St Helens. The dome height model, combined with the apparent time-predictable nature of volcanic eruptions of the Kameni islands, allows us to predict that the next eruption of the Kameni islands will last for > 2.6 years (in 2005) and will involve formation of a dome ca. 115 to 123 m high.

  17. 7 CFR 201.58a - Indistinguishable seeds.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... in a glass container. (3) Chemical reaction: When seeds have imbibed, remove excess water and add... subjected to the chemical test as follows: (1) Preparation of test solution: Add 3 grams of cupric sulfate... that a complete reaction has taken place between CuSO4 and NH4 OH; otherwise fumes from excess...

  18. 7 CFR 201.58a - Indistinguishable seeds.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... in a glass container. (3) Chemical reaction: When seeds have imbibed, remove excess water and add... subjected to the chemical test as follows: (1) Preparation of test solution: Add 3 grams of cupric sulfate... that a complete reaction has taken place between CuSO4 and NH4 OH; otherwise fumes from excess...

  19. 7 CFR 201.58a - Indistinguishable seeds.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... in a glass container. (3) Chemical reaction: When seeds have imbibed, remove excess water and add... subjected to the chemical test as follows: (1) Preparation of test solution: Add 3 grams of cupric sulfate... that a complete reaction has taken place between CuSO4 and NH4 OH; otherwise fumes from excess...

  20. 7 CFR 201.58a - Indistinguishable seeds.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... in a glass container. (3) Chemical reaction: When seeds have imbibed, remove excess water and add... subjected to the chemical test as follows: (1) Preparation of test solution: Add 3 grams of cupric sulfate... that a complete reaction has taken place between CuSO4 and NH4 OH; otherwise fumes from excess...

  1. 7 CFR 201.58a - Indistinguishable seeds.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... in a glass container. (3) Chemical reaction: When seeds have imbibed, remove excess water and add... subjected to the chemical test as follows: (1) Preparation of test solution: Add 3 grams of cupric sulfate... that a complete reaction has taken place between CuSO4 and NH4 OH; otherwise fumes from excess...

  2. Quantum indistinguishability from general representations of SU(2n)

    NASA Astrophysics Data System (ADS)

    Harrison, J. M.; Robbins, J. M.

    2004-04-01

    A treatment of the spin-statistics relation in nonrelativistic quantum mechanics due to Berry and Robbins [Proc. R. Soc. London Ser. A 453, 1771-1790 (1997)] is generalized within a group-theoretical framework. The construction of Berry and Robbins is reformulated in terms of certain locally flat vector bundles over n-particle configuration space. It is shown how families of such bundles can be constructed from irreducible representations of the group SU(2n). The construction of Berry and Robbins, which leads to a definite connection between spin and statistics (the physically correct connection), is shown to correspond to the completely symmetric representations. The spin-statistics connection is typically broken for general SU(2n) representations, which may admit, for a given value of spin, both Bose and Fermi statistics, as well as parastatistics. The determination of the allowed values of the spin and statistics reduces to the decomposition of certain zero-weight representations of a (generalized) Weyl group of SU(2n). A formula for this decomposition is obtained using the Littlewood-Richardson theorem for the decomposition of representations of U(m+n) into representations of U(m)×U(n).

  3. Temporal coherence and indistinguishability in two-photon interference effects

    SciTech Connect

    Jha, Anand Kumar; O'Sullivan, Malcolm N.; Chan, Kam Wai Clifford; Boyd, Robert W.

    2008-02-15

    We show that temporal two-photon interference effects involving the signal and idler photons created by parametric down-conversion can be fully characterized in terms of the variations of two length parameters--called the biphoton path-length difference and the biphoton path-asymmetry-length difference--which we construct using the six different length parameters that a general two-photon interference experiment involves. We perform an experiment in which the effects of the variations of these two parameters can be independently controlled and studied. In our experimental setup, which does not involve mixing of signal and idler photons at a beam splitter, we further report observations of Hong-Ou-Mandel- (HOM-)like effects both in coincidence and in one-photon count rates. As an important consequence, we argue that the HOM and the HOM-like effects are best described as observations of how two-photon coherence changes as a function of the biphoton path-asymmetry-length difference.

  4. Morphological instabilities of polymer crystals.

    PubMed

    Grozev, N; Botiz, I; Reiter, G

    2008-09-01

    We present experimental observations at comparatively low supercooling of morphology transitions from dendritic to faceted structures in polymer crystals growing in thin films of a poly-2-vinylpyridine-block-polyethyleneoxid copolymer. Our results are compared with theoretical concepts describing morphological instabilities of single crystals. Although these concepts originally were not developed for polymers, they allow to describe and interpret our experimental results quite well. In particular, the measured temperature dependence of the width W and frequency of dendritic side branches and the radius of curvature p of the growth tips of the crystals follow these concepts. We present preliminary evidence for the influence of polymer attachment kinetics and reorganisation processes behind the growth front. Polymer thin films provide valuable model systems for studying general concepts of crystallisation and allow to distinguish at which point the connectivity of the crystallising units within chain-like molecules starts to play a measurable role.

  5. Morphological castes in a vertebrate

    PubMed Central

    O'Riain, M. J.; Jarvis, J. U. M.; Alexander, R.; Buffenstein, R.; Peeters, C.

    2000-01-01

    Morphological specialization for a specific role has, until now, been assumed to be restricted to social invertebrates. Herein we show that complete physical dimorphism has evolved between reproductives and helpers in the eusocial naked mole-rat. Dimorphism is a consequence of the lumbar vertebrae lengthening after the onset of reproduction in females. This is the only known example of morphological castes in a vertebrate and is distinct from continuous size variation between breeders and helpers in other species of cooperatively breeding vertebrates. The evolution of castes in a mammal and insects represents a striking example of convergent evolution for enhanced fecundity in societies characterized by high reproductive skew. Similarities in the selective environment between naked mole-rats and eusocial insect species highlight the selective conditions under which queen/worker castes are predicted to evolve in animal societies. PMID:11087866

  6. Quantitative Morphology of Epithelial Folds

    PubMed Central

    Štorgel, Nick; Krajnc, Matej; Mrak, Polona; Štrus, Jasna; Ziherl, Primož

    2016-01-01

    The shape of spatially modulated epithelial morphologies such as villi and crypts is usually associated with the epithelium-stroma area mismatch leading to buckling. We propose an alternative mechanical model based on intraepithelial stresses generated by differential tensions of apical, lateral, and basal sides of cells as well as on the elasticity of the basement membrane. We use it to theoretically study longitudinal folds in simple epithelia and we identify four types of corrugated morphologies: compact, invaginated, evaginated, and wavy. The obtained tissue contours and thickness profiles are compared to epithelial folds observed in invertebrates and vertebrates, and for most samples, the agreement is within the estimated experimental error. Our model establishes the groove-crest modulation of tissue thickness as a morphometric parameter that can, together with the curvature profile, be used to estimate the relative differential apicobasal tension in the epithelium. PMID:26745429

  7. Morphological details in bloodstain particles.

    PubMed

    De Wael, K; Lepot, L

    2015-01-01

    During the commission of crimes blood can be transferred to the clothing of the offender or on other crime related objects. Bloodstain particles are sub-millimetre sized flakes that are lost from dried bloodstains. The nature of these red particles is easily confirmed using spectroscopic methods. In casework, bloodstain particles showing highly detailed morphological features were observed. These provided a rationale for a series of experiments described in this work. It was found that the "largest" particles are shed from blood deposited on polyester and polyamide woven fabrics. No particles are lost from the stains made on absorbent fabrics and from those made on knitted fabrics. The morphological features observed in bloodstain particles can provide important information on the substrates from which they were lost.

  8. Pyrolytic carbon indentation crack morphology.

    PubMed

    Ely, J L; Stupka, J; Haubold, A D

    1996-06-01

    In studying fatigue and fracture behavior of brittle materials, Vickers diamond indentation cracks are often used. Many of the studies of indentation cracks use crack system models such as the radial-median crack or Palmqvist crack. These systems are also used to study small crack growth in brittle materials, and have been studied for pyrolytic carbon. However, the true morphology of these cracks in pyrolytic carbon coatings on graphite substrates have not been described. This study examined Vickers diamond and spherical ball indentation cracks in pyrolytic carbon coatings using several techniques, including serial metallographic cross sections, indentation fracture in bending, acoustic emission, and residual surface indentation scanning. The crack systems developed using these techniques were not typical of either radial median or Palmqvist systems. The morphology is unique to this material, possibly because of the coating thickness limitations. Given the difference in crack system, the application of standard indentation crack equations in studying fracture mechanics, especially for small cracks, must be questioned.

  9. COSMOS Galaxy Morphology Pilot Project

    NASA Astrophysics Data System (ADS)

    Prescott, M.; Impey, C.; Scoville, N.; COSMOS Collaboration

    2004-05-01

    The COSMOS (Cosmic Evolution Survey) project will be the largest HST imaging survey ever, covering two square degrees with the ACS instrument. The survey is designed to sample the full range of cosmic structures up to scales of 100 Mpc, map the evolution of galaxy morphology, galaxy merging, and star formation out to z of 2, use weak lensing to reconstruct the dark matter distribution out to z of 1, and study the joint evolution of galaxies and black holes via the AGN population. Extensive multi-wavelength observations of the field have also been committed for X-ray, UV, FIR, NIR, millimeter, and radio wavelengths. We present results from a pilot project using only the central 10.4 by 10.4 arcmin portion of the field. The goal is to understand the reliability of galaxy morphological information derived from GALFIT and other methods. Morphology has been derived from both g and i ACS images in terms of bulge/disk ratio and Sersic index. These measures have been augmented by CAS and Gini coefficients as a way of identifying galaxies that are disturbed or interacting, or where the axisymmetric assumptions of GALFIT are not warranted. We present results on how morphology correlates with global quantities such as luminosity, scale length, and mean surface brightness as well as with various broad band color combinations, which serve as proxies for overall stellar populations and ages. Using photo-z's we study all these relationships in terms of cosmic evolution. This pilot project will be used to optimize analysis strategies for the much larger amount of data in the overall COSMOS project. Funding for this work was provided by a NSF Graduate Fellowship and a NASA/HST GO Grant.

  10. The morphological diagram of spinels

    SciTech Connect

    Ziolkowski, J.

    1996-02-01

    Catalytic anisotropy in mild oxidation reactions results from the varying activity of different crystal faces. Here, spinels exposing (100), (110), and (111) faces have been considered and their Curie-Wulff plots have been drawn, admitting that the relative G(hkl) surface free energies may change in a wide range as a function of composition, inversion, and segregation degree. The normalized free surface energies are defined as A = G(100)/G(111), B = G(110)/G(111), and C = G(111)/G(111) = 1 = const. This made it possible to construct bidimensional morphological diagrams (morphology = f(A,B) at C = const) in the exposed-face-type, solid-type, and exposure-percentage versions. Eleven morphological habits of grains have been identified, including (100)-cube, (110)-dodecahedron, (111)-hexagons, 18-hedron, 20-hedron, and up to 26-hedra bordered with (i) 6 (100)-octagons, 12 (110)-rectangles, and 8 (111)-hexagons, (ii) 6 (100)-squares, 12 (110)-rectangles, and 8 (111)-triangles, or (iii) 6 (100)-squares, 12 (110)-octagons, and 8 (100)-triangles. The analysis is valid for all compounds crystallizing in the cubic system and preferentially exposing the three enumerated faces.

  11. Thermodynamics of catalytic nanoparticle morphology

    NASA Astrophysics Data System (ADS)

    Zwolak, Michael; Sharma, Renu; Lin, Pin Ann

    Metallic nanoparticles are an important class of industrial catalysts. The variability of their properties and the environment in which they act, from their chemical nature & surface modification to their dispersion and support, allows their performance to be optimized for many chemical processes useful in, e.g., energy applications and other areas. Their large surface area to volume ratio, as well as varying sizes and faceting, in particular, makes them an efficient source for catalytically active sites. These characteristics of nanoparticles - i.e., their morphology - can often display intriguing behavior as a catalytic process progresses. We develop a thermodynamic model of nanoparticle morphology, one that captures the competition of surface energy with other interactions, to predict structural changes during catalytic processes. Comparing the model to environmental transmission electron microscope images of nickel nanoparticles during carbon nanotube (and other product) growth demonstrates that nickel deformation in response to the nanotube growth is due to a favorable interaction with carbon. Moreover, this deformation is halted due to insufficient volume of the particles. We will discuss the factors that influence morphology and also how the model can be used to extract interaction strengths from experimental observations.

  12. Astragalar Morphology of Selected Giraffidae

    PubMed Central

    2016-01-01

    The artiodactyl astragalus has been modified to exhibit two trochleae, creating a double pullied structure allowing for significant dorso-plantar motion, and limited mediolateral motion. The astragalus structure is partly influenced by environmental substrates, and correspondingly, morphometric studies can yield paleohabitat information. The present study establishes terminology and describes detailed morphological features on giraffid astragali. Each giraffid astragalus exhibits a unique combination of anatomical characteristics. The giraffid astragalar morphologies reinforce previously established phylogenetic relationships. We find that the enlargement of the navicular head is a feature shared by all giraffids, and that the primitive giraffids possess exceptionally tall astragalar heads in relation to the total astragalar height. The sivatheres and the okapi share a reduced notch on the lateral edge of the astragalus. We find that Samotherium is more primitive in astragalar morphologies than Palaeotragus, which is reinforced by tooth characteristics and ossicone position. Diagnostic anatomical characters on the astragalus allow for giraffid species identifications and a better understanding of Giraffidae. PMID:27028515

  13. Island morphologies in epitaxial growth.

    NASA Astrophysics Data System (ADS)

    Hessinger, Uwe; Leskovar, M.; Rumaner, Lee; Ohuchi, Fumio; Olmstead, Marjorie A.; Ueno, Keiji; Koma, Atsushi

    1996-03-01

    Growth of epitaxial films commonly occurs through the coalescence of individual islands. The morphology of islands has therefore a key importance for the film qualities desired. A uniform layer-by-layer growth of the film is achieved when islands in the first layer coalesce to form a uniform layer before a second layer nucleates; a non-uniform multi-layer growth results from multiple layers successively nucleating on top of each other before the first layer coalesces. We developed a kinetic model based on an analytic solution of the diffusion equation between nucleation events to calculate the evolving island morphology during growth. The morphologies depend on deposition rate, substrate temperature, and activation energies for surface diffusion on the substrate and deposited material. By applying this theory to atomic force microscopy data of GaSe multi-layer islands, we extract a value for the activation energy for Ga diffusion across steps of GaSe. Supported by NSF Grant No. ECS-9209652, DOE Grant No. DE-FG06-94ER45516, and the Japanese New Energy Development Organization.

  14. Morphological plasticity of vertebrate aestivation.

    PubMed

    Secor, Stephen M; Lignot, Jean-Herve

    2010-01-01

    Aestivation or daily torpor is an adaptive tactic to survive hot and dry periods of low food availability, and has been documented for species of lungfishes, teleost fishes, amphibians, reptiles, birds, and mammals. Among these species, aestivation is characterized by inactivity and fasting, and for lungfishes and amphibians the formation of a cocoon around the body to retard water loss. While metabolic and physiological changes to aestivation have been well examined, few studies have explored the morphological responses of organs and tissues to aestivation. Predictably, inactive tissues such as skeletal muscles and those of the gastrointestinal tract would regress during aestivation, and thus aid in the reduction of metabolic rate. African lungfishes experience changes in the structure of their skin, gills, lungs, and heart during aestivation. For anurans, the group most thoroughly examined for morphological responses, aestivation generates significant decreases in gut mass and modification of the intestinal epithelium. Intestinal mucosal thickness, enterocyte size, and microvillus length of anurans are characteristically reduced during aestivation. We can surmise from laboratory studies on fasting reptiles, birds, and mammals that they likewise experience atrophy of their digestive tissues during torpor or aestivation. Aestivation-induced loss of tissue structure may be matched with a loss of cellular function generating an integrative decrease in tissue performance and metabolism. Ample opportunity exists to remedy the paucity of studies on the morphological plasticity of organs and tissues to aestivation and examine how such responses dictate tissue function during and immediately following aestivation.

  15. Hydrodynamics, Fungal Physiology, and Morphology.

    PubMed

    Serrano-Carreón, L; Galindo, E; Rocha-Valadéz, J A; Holguín-Salas, A; Corkidi, G

    2015-01-01

    Filamentous cultures, such as fungi and actinomycetes, contribute substantially to the pharmaceutical industry and to enzyme production, with an annual market of about 6 billion dollars. In mechanically stirred reactors, most frequently used in fermentation industry, microbial growth and metabolite productivity depend on complex interactions between hydrodynamics, oxygen transfer, and mycelial morphology. The dissipation of energy through mechanically stirring devices, either flasks or tanks, impacts both microbial growth through shearing forces on the cells and the transfer of mass and energy, improving the contact between phases (i.e., air bubbles and microorganisms) but also causing damage to the cells at high energy dissipation rates. Mechanical-induced signaling in the cells triggers the molecular responses to shear stress; however, the complete mechanism is not known. Volumetric power input and, more importantly, the energy dissipation/circulation function are the main parameters determining mycelial size, a phenomenon that can be explained by the interaction of mycelial aggregates and Kolmogorov eddies. The use of microparticles in fungal cultures is also a strategy to increase process productivity and reproducibility by controlling fungal morphology. In order to rigorously study the effects of hydrodynamics on the physiology of fungal microorganisms, it is necessary to rule out the possible associated effects of dissolved oxygen, something which has been reported scarcely. At the other hand, the processes of phase dispersion (including the suspended solid that is the filamentous biomass) are crucial in order to get an integral knowledge about biological and physicochemical interactions within the bioreactor. Digital image analysis is a powerful tool for getting relevant information in order to establish the mechanisms of mass transfer as well as to evaluate the viability of the mycelia. This review focuses on (a) the main characteristics of the two most

  16. New phylogenetic analysis of the family elephantidae based on cranial-dental morphology.

    PubMed

    Todd, Nancy E

    2010-01-01

    In 1973, Vincent Maglio published a seminal monograph on the evolution of the Elephantidae, in which he revised and condensed the 100+ species named by Henry Fairfield Osborn in 1931. Michel Beden further revised the African Elephantidae in 1979, but little systematic work has been done on the family since this publication. With addition of new specimens and species and revisions of chronology, a new analysis of the phylogeny and systematics of this family is warranted. A new, descriptive character dataset was generated from studies of modern elephants for use with fossil species. Parallel evolution in cranial and dental characters in all three lineages of elephants creates homoplastic noise in cladistic analysis, but new inferences about evolutionary relationships are possible. In this analysis, early Loxodonta and early African Mammuthus are virtually indistinguishable in dental morphology. The Elephas lineage is not monophyletic, and results from this analysis suggest multiple migration events out of Africa into Eurasia, and possibly back into Africa. New insight into the origin of the three lineages is also proposed, with Stegotetrabelodon leading to the Mammuthus lineage, and Primelephas as the ancestor of Loxodonta and Elephas. These new results suggest a much more complex picture of elephantid origins, evolution, and paleogeography.

  17. Hybrid and Nonhybrid Lipids Exert Common Effects on Membrane Raft Size and Morphology

    SciTech Connect

    Heberle, Frederick A; Doktorova, Milka; Goh, Shih Lin; Standaert, Robert F; Katsaras, John; Feigenson, Gerald

    2013-01-01

    Nanometer-scale domains in cholesterolrich model membranes emulate lipid rafts in cell plasma membranes (PMs). The physicochemical mechanisms that maintain a finite, small domain size are, however, not well understood. A special role has been postulated for chainasymmetric or hybrid lipids having a saturated sn-1 chain and an unsaturated sn-2 chain. Hybrid lipids generate nanodomains in some model membranes and are also abundant in the PM. It was proposed that they align in a preferred orientation at the boundary of ordered and disordered phases, lowering the interfacial energy and thus reducing domain size. We used small-angle neutron scattering and fluorescence techniques to detect nanoscopic and modulated liquid phase domains in a mixture composed entirely of nonhybrid lipids and cholesterol. Our results are indistinguishable from those obtained previously for mixtures containing hybrid lipids, conclusively showing that hybrid lipids are not required for the formation of nanoscopic liquid domains and strongly implying a common mechanism for the overall control of raft size and morphology. We discuss implications of these findings for theoretical descriptions of nanodomains.

  18. Concordant morphologic and gene expression data show that a vaccine halts HER-2/neu preneoplastic lesions

    PubMed Central

    Quaglino, Elena; Rolla, Simona; Iezzi, Manuela; Spadaro, Michela; Musiani, Piero; De Giovanni, Carla; Lollini, Pier Luigi; Lanzardo, Stefania; Forni, Guido; Sanges, Remo; Crispi, Stefania; De Luca, Pasquale; Calogero, Raffaele; Cavallo, Federica

    2004-01-01

    While much experimental data shows that vaccination efficiently inhibits a subsequent challenge by a transplantable tumor, its ability to inhibit the progress of autochthonous preneoplastic lesions is virtually unknown. In this article, we show that a combined DNA and cell vaccine persistently inhibits such lesions in a murine HER-2/neu mammary carcinogenesis model. At 10 weeks of age, all of the ten mammary gland samples from HER-2/neu–transgenic mice displayed foci of hyperplasia that progressed to invasive tumors. Vaccination with plasmids coding for the transmembrane and extracellular domain of rat p185neu followed by a boost with rp185neu+ allogeneic cells secreting IFN-γ kept 48% of mice tumor free. At 22 weeks, their mammary glands were indistinguishable from those of 10-week-old untreated mice. Furthermore, the transcription patterns of the two sets of glands coincided. Of the 12,000 genes analyzed, 17 were differentially expressed and related to the antibody response. The use of B cell knockout mice as well as the concordance of morphologic and gene expression data demonstrated that the Ab response is the main mechanism facilitating tumor growth arrest. This finding suggests that a new way can be found to secure the immunologic control of the progression of HER-2/neu preneoplastic lesions. PMID:14991069

  19. MeCP2 Affects Skeletal Muscle Growth and Morphology through Non Cell-Autonomous Mechanisms.

    PubMed

    Conti, Valentina; Gandaglia, Anna; Galli, Francesco; Tirone, Mario; Bellini, Elisa; Campana, Lara; Kilstrup-Nielsen, Charlotte; Rovere-Querini, Patrizia; Brunelli, Silvia; Landsberger, Nicoletta

    2015-01-01

    Rett syndrome (RTT) is an autism spectrum disorder mainly caused by mutations in the X-linked MECP2 gene and affecting roughly 1 out of 10.000 born girls. Symptoms range in severity and include stereotypical movement, lack of spoken language, seizures, ataxia and severe intellectual disability. Notably, muscle tone is generally abnormal in RTT girls and women and the Mecp2-null mouse model constitutively reflects this disease feature. We hypothesized that MeCP2 in muscle might physiologically contribute to its development and/or homeostasis, and conversely its defects in RTT might alter the tissue integrity or function. We show here that a disorganized architecture, with hypotrophic fibres and tissue fibrosis, characterizes skeletal muscles retrieved from Mecp2-null mice. Alterations of the IGF-1/Akt/mTOR pathway accompany the muscle phenotype. A conditional mouse model selectively depleted of Mecp2 in skeletal muscles is characterized by healthy muscles that are morphologically and molecularly indistinguishable from those of wild-type mice raising the possibility that hypotonia in RTT is mainly, if not exclusively, mediated by non-cell autonomous effects. Our results suggest that defects in paracrine/endocrine signaling and, in particular, in the GH/IGF axis appear as the major cause of the observed muscular defects. Remarkably, this is the first study describing the selective deletion of Mecp2 outside the brain. Similar future studies will permit to unambiguously define the direct impact of MeCP2 on tissue dysfunctions.

  20. Morphological and Genetic Diversity of Opisthosporidia: New Aphelid Paraphelidium tribonemae gen. et sp. nov.

    PubMed

    Karpov, Sergey A; Tcvetkova, Victoria S; Mamkaeva, Maria A; Torruella, Guifré; Timpano, Hélène; Moreira, David; Mamanazarova, Karomat S; López-García, Purificación

    2017-03-01

    Aphelids are a poorly known group of parasitoids of algae that have raised considerable interest due to their pivotal phylogenetic position. Together with Cryptomycota and the highly derived Microsporidia, they have been recently re-classified as the Opisthosporidia, which constitute the sister group to the fungi within the Holomycota. Despite their huge diversity, as revealed by molecular environmental studies, and their phylogenetic interest, only three genera have been described (Aphelidium, Amoeboaphelidium, and Pseudaphelidium), from which 18S rRNA gene sequences exist only for Amoeboaphelidium and Aphelidium species. Here, we describe the life cycle and ultrastructure of a new representative of Aphelida, Paraphelidium tribonemae gen. et sp. nov., and provide the first 18S rRNA gene sequence obtained for this genus. Molecular phylogenetic analysis indicates that Paraphelidium is distantly related to both Aphelidium and Amoebaphelidium, highlighting the wide genetic diversity of aphelids. Paraphelidium tribonemae has amoeboflagellate zoospores containing a lipid-microbody complex, dictyosomes, and mitochondria with rhomboid cristae, which are also present in trophonts and plasmodia. The amoeboid trophont uses pseudopodia to feed from the host cytoplasm. Although genetically distinct, the genus Paraphelidium is morphologically indistinguishable from other aphelid genera and has zoospores able to produce lamellipodia with subfilopodia like those of Amoeboaphelidium.

  1. Concordant morphologic and gene expression data show that a vaccine halts HER-2/neu preneoplastic lesions.

    PubMed

    Quaglino, Elena; Rolla, Simona; Iezzi, Manuela; Spadaro, Michela; Musiani, Piero; De Giovanni, Carla; Lollini, Pier Luigi; Lanzardo, Stefania; Forni, Guido; Sanges, Remo; Crispi, Stefania; De Luca, Pasquale; Calogero, Raffaele; Cavallo, Federica

    2004-03-01

    While much experimental data shows that vaccination efficiently inhibits a subsequent challenge by a transplantable tumor, its ability to inhibit the progress of autochthonous preneoplastic lesions is virtually unknown. In this article, we show that a combined DNA and cell vaccine persistently inhibits such lesions in a murine HER-2/neu mammary carcinogenesis model. At 10 weeks of age, all of the ten mammary gland samples from HER-2/neu-transgenic mice displayed foci of hyperplasia that progressed to invasive tumors. Vaccination with plasmids coding for the transmembrane and extracellular domain of rat p185neu followed by a boost with rp185neu+ allogeneic cells secreting IFN-gamma kept 48% of mice tumor free. At 22 weeks, their mammary glands were indistinguishable from those of 10-week-old untreated mice. Furthermore, the transcription patterns of the two sets of glands coincided. Of the 12,000 genes analyzed, 17 were differentially expressed and related to the antibody response. The use of B cell knockout mice as well as the concordance of morphologic and gene expression data demonstrated that the Ab response is the main mechanism facilitating tumor growth arrest. This finding suggests that a new way can be found to secure the immunologic control of the progression of HER-2/neu preneoplastic lesions.

  2. Science to Practice: Does FDG Differentiate Morphologically Unstable from Stable Atherosclerotic Plaque?

    PubMed

    Dilsizian, Vasken; Jadvar, Hossein

    2017-04-01

    It has been reported that fluorine 18 fluorodeoxyglucose (FDG) positron emission tomography (PET) may detect the inflammatory state and macrophage burden of atherosclerotic plaques and potentially identify vulnerable plaques. However, published reports have been inconsistent in this area. Tavakoli et al ( 1 ) hypothesized that differential regulation of macrophage glucose metabolism by macrophage colony-stimulating factor (M-CSF; inflammation resolving) and granulocyte-M-CSF (GM-CSF; proinflammatory) may contribute to the inconsistency of FDG vessel wall inflammation. After the induction of inflammatory and metabolic profiles, both M-CSF and GM-CSF generated comparable levels of glucose uptake in cultured macrophages and murine atherosclerotic plaques. These findings suggest that although FDG uptake is an indicator of vascular macrophage burden (total number of macrophages), it may not necessarily differentiate morphologically unstable (inflammatory) from stable (noninflammatory) atherosclerotic plaque. Moreover, although atherosclerosis is characterized by macrophage-predominated inflammation, there is a wide range of other vascular diseases in which macrophages and inflammation play an important role in the absence of atherosclerosis. FDG uptake will be indistinguishable in atherosclerosis from large-artery inflammatory vascular disease, such as Takayasu arteritis, chemotherapy- or radiation-induced vascular inflammation, or foreign-body reaction, such as synthetic arterial graft. Because of the nonspecific nature of FDG uptake by any cell (upregulated under hypoxic conditions or other microenvironmental factors), this work calls for a more cautious approach to interpreting vascular FDG uptake as indicative of inflammatory atherosclerosis in the clinical setting.

  3. Ovarian teratoma displaying a wide variety of tissue components in a broiler chicken (Gallus Domesticus): morphological heterogeneity of pluripotential germ cell during tumorigenesis

    PubMed Central

    Ohfuji, S.

    2016-01-01

    Spontaneous ovarian teratoma was found in a seven-week-old female Chunky broiler chicken that was slaughtered for food. On post-mortem inspection, a spherical tumor mass attaching to a juvenile ovary was found in the abdominal cavity. Histopathologically, the tumor was comprised of immature mesenchymal stroma and a variety of mature tissue elements of mesodermal and ectodermal origin. In addition, there were multiple indistinguishable tissue elements, which showed no malignant cytological features but were unidentifiable as to corresponding embryological layer of origin. These heterogeneous teratoma tissues consisted of a variety of glandular, cystic, duct-like, and tubular structures, some of which exhibited a lining by a mixture of both keratinizing/non-keratinizing stratified squamous epithelial cells and cuboidal/columnar epithelial cells. The ovarian tetatoma was considered a benign and congenital one. The highly diverse differentiation of the teratoma might have manifested a morphological aspect of intrinsic character of the pluripotential germ cells during tumorigenesis. PMID:27303655

  4. Metal oxide nanostructures with hierarchical morphology

    SciTech Connect

    Ren, Zhifeng; Lao, Jing Yu; Banerjee, Debasish

    2007-11-13

    The present invention relates generally to metal oxide materials with varied symmetrical nanostructure morphologies. In particular, the present invention provides metal oxide materials comprising one or more metallic oxides with three-dimensionally ordered nanostructural morphologies, including hierarchical morphologies. The present invention also provides methods for producing such metal oxide materials.

  5. Morphology in Language Comprehension, Production and Acquisition

    ERIC Educational Resources Information Center

    Bertram, Raymond; Hyona, Jukka; Laine, Matti

    2011-01-01

    This Special Issue on Morphological Processing is based on the sixth MOrphological PROcessing Conference (MOPROC), which was kept in June 2009 in Turku, Finland. The issue contains 13 articles by leading scholars in the field of morphological processing. These articles investigate the role morphemes play in language comprehension, production and…

  6. Imaging Implicit Morphological Processing: Evidence from Hebrew

    ERIC Educational Resources Information Center

    Bick, Atira S.; Frost, Ram; Goelman, Gadi

    2010-01-01

    Is morphology a discrete and independent element of lexical structure or does it simply reflect a fine-tuning of the system to the statistical correlation that exists among orthographic and semantic properties of words? Hebrew provides a unique opportunity to examine morphological processing in the brain because of its rich morphological system.…

  7. Morphological Stability of Faceted Interfaces

    NASA Technical Reports Server (NTRS)

    Abbaschian, Reza; Golyshev, V. D.; Gonik, M.; Tsvetivsky, V.; deVahlDavis, G.; Leonardi, E.

    2001-01-01

    The major focus of this investigation is to study the fundamentals of layer spreading mechanisms during growth of doped Ge (a facet forming material), and to determine the conditions for morphological instability of vicinal solid-liquid interfaces. The investigation will also lead to the determination of the effect of dopants on the layer growth kinetics, step free energy, and dopant capture by the advancing ledges. The theoretical treatment of growth of faceted interfaces indicates that the kinetics of a step on a growing vicinal interface considerably depends on its angle of inclination, the melt concentration, and characteristics of flow currents in the melt. The morphological stability of the interface also depends on these parameters, as well as on the density and spreading velocity of the steps. However, the treatment of the instability of the interface by the layer growth mechanism is rather difficult because it requires exact knowledge of the thermal and solutal fields, hydrodynamics of the melt, and supercooling at the interface. The results of recent space experiments of the principal investigator involving directional solidification of faceted Bi-Sn alloys have shown that the morphological stability of various crystallographic orientations is significantly affected by the anistropy in interfacial properties of the faceted alloy in general, and the interface kinetics in particular. These findings have also raised many important and fundamental questions, particularly with respect to the behavior of interfacial steps, which need to be addressed via additional groundbased and microgravity experiments. For the present investigation we will use a novel crystal growth technique which provides axial heat flux close to the solid-liquid boundary. The Axial Heat Processing (AHP) technique allows for precise control and determination of the heat and mass transfer close to the crystallization front, and the establishment of a planar interface over the entire cross

  8. Morphological aspects of surface reactions

    SciTech Connect

    White, J.M.

    1992-08-01

    This program involves the preparation and characterization (both structural and kinetic) of metal-based catalysts and adsorbates thereon. The substrates involve mainly Rh and Ag; oxides of Si, Al and Ti are used for supports for particles and thin metal films. Adsorbates include carbon oxides, halogenated hydrocarbons, benzene and alkalis. Particular attention is given to synthesis of hydrocarbon fragments by photochemical and electron-induced methods. Tunneling microscopy and spectroscopy are used to study the morphology and electronic structure of the metals. (DLC)

  9. Hair morphology and anthropological applications.

    PubMed

    Guilbeau-Frugier, Céline; Blanc, Antony; Crubezy, Eric; Delisle, Marie-Bernadette; Rouge, Daniel; Telmon, Norbert

    2006-01-01

    The histological study of hair has a long history, dating from the 19th century. We obtained a collection of hair taken from people of known geographic origin. We analyzed these samples according to their transversal cut shape index, derived from computerized image-processing. We noted statistically significant variation according to the geographic origin of subjects. This morphological variation may reflect genetic distance. This reliable, quick, and cheap technique could be used in other existing anthropological material for which DNA analysis is usually difficult.

  10. He-Ion and Self-Atom Induced Damage and Surface-Morphology Changes of a Hot W Target

    SciTech Connect

    Meyer, Fred W; Hijazi, Hussein Dib; Krstic, Predrag S; Dadras, Mostafa Jonny; Meyer III, Harry M; Parish, Chad M; Bannister, Mark E

    2014-01-01

    We report results of measurements on the evolution of the surface morphology of a hot tungsten surface due to impacting low-energy (80 12,000 eV) He ions and of simulations of damage caused by cumulative bombardment of 1 and 10 keV W self-atoms. The measurements were performed at the ORNL Multicharged Ion Research Facility (MIRF), while the simulations were done at the Kraken supercomputing facility of the University of Tennessee. At 1 keV, the simulations show strong defect-recombination effects that lead to a saturation of the total defect number after a few hundreds impacts, while sputtering leads to an imbalance of the vacancy and interstitial number. On the experimental side, surface morphology changes were investigated over a broad range of fluences for both virgin and pre-damaged W-targets. At the lowest accumulated fluences, small surface-grain features and near-surface He bubbles are observed. At the largest fluences, individual grain characteristics disappear in FIB/SEM scans, and the entire surface is covered by a multitude of near-surface bubbles with a broad range of sizes, and disordered whisker growth, while in top-down SEM imaging the surface is virtually indistinguishable from the nano-fuzz produced on linear plasma devices. These features are evident at progressively lower fluences as the He-ion energy is increased.

  11. A Phylogeny of the Family Poritidae (Cnidaria, Scleractinia) Based on Molecular and Morphological Analyses

    PubMed Central

    Kitano, Yuko F.; Benzoni, Francesca; Arrigoni, Roberto; Shirayama, Yoshihisa; Wallace, Carden C.; Fukami, Hironobu

    2014-01-01

    The family Poritidae formerly included 6 genera: Alveopora, Goniopora, Machadoporites, Porites, Poritipora, and Stylaraea. Morphologically, the genera can be differentiated based on the number of tentacles, the number of septa and their arrangement, the length of the polyp column, and the diameter of the corallites. However, the phylogenetic relationships within and between the genera are unknown or contentious. On the one hand, Alveopora has been transferred to the Acroporidae recently because it was shown to be more closely related to this family than to the Poritidae by previous molecular studies. On the other hand, Goniopora is morphologically similar to 2 recently described genera, Machadoporites and Poritipora, particularly with regard to the number of septa (approximately 24), but they have not yet been investigated at the molecular level. In this study, we analyzed 93 samples from all 5 poritid genera and Alveopora using 2 genetic markers (the barcoding region of the mitochondrial COI and the ITS region of the nuclear rDNA) to investigate their phylogenetic relationships and to revise their taxonomy. The reconstructed molecular trees confirmed that Alveopora is genetically distant from all poritid genera but closely related to the family Acroporidae, whereas the other genera are genetically closely related. The molecular trees also revealed that Machadoporites and Poritipora were indistinguishable from Goniopora. However, Goniopora stutchburyi was genetically isolated from the other congeneric species and formed a sister group to Goniopora together with Porites and Stylaraea, thus suggesting that 24 septa could be an ancestral feature in the Poritidae. Based on these data, we move G. stutchburyi into a new genus, Bernardpora gen. nov., whereas Machadoporites and Poritipora are merged with Goniopora. PMID:24871224

  12. Lipidomic analysis can distinguish between two morphologically similar strains of Nannochloropsis oceanica.

    PubMed

    Li, Shuang; Xu, Jilin; Jiang, Ying; Zhou, Chengxu; Yu, Xuejun; Zhong, Yingying; Chen, Juanjuan; Yan, Xiaojun

    2015-04-01

    The two morphologically similar microalgae NMBluh014 and NMBluh-X belong to two different strains of Nannochloropsis oceanica. They possess obviously different feeding effects on bivalves, but are indistinguishable by 18S rRNA and morphological features. In this work, lipidomic analysis followed by principal component analysis and orthogonal projections to latent structures discriminant analysis provided a clear distinction between these strains. Metabolites that definitively contribute to the classification were selected as potential biomarkers. The most important difference in polar lipids were sulfoquinovosyldiacylglycerol (containing 18:1/16:0 and 18:3/16:0) and monogalactosyldiacylglycerol (containing 18:3/16:3 and 20:5/14:0), which were detected only in NMBluh-X. Additionally, an exhaustive qualitative and quantitative profiling of the neutral lipid triacylglycerol (TAG) in the two strains was carried out. The predominant species of TAG containing 16:1/16:1/16:1 acyl groups was detected only in NMBluh-X with a content of ~93.67 ± 11.85 nmol · mg(-1) dry algae at the onset of stationary phase. Meanwhile, TAG containing 16:0/16:0/16:0 was the main TAG in NMBluh014 with a content of 40.25 ± 3.92 nmol · mg(-1) . These results provided the most straightforward evidence for differentiating the two species. The metabolomic profiling indicated that NMBluh-X underwent significant chemical and physiological changes during the growth process, whereas NMBluh014 did not show such noticeable time-dependent metabolite change. This study is the first using Ultra Performance Liquid Chromatography coupled with Electrospray ionization-Quadrupole-Time of Flight Mass Spectrometry (UPLC-Q-TOF-MS) for lipidomic profiling with multivariate statistical analysis to explore lipidomic differences of plesiomorphous microalgae. Our results demonstrate that lipidomic profiling is a valid chemotaxonomic tool in the study of microalgal systematics.

  13. Morphology of atherosclerotic coronary arteries

    NASA Astrophysics Data System (ADS)

    Holme, Margaret N.; Schulz, Georg; Deyhle, Hans; Hieber, Simone Elke; Weitkamp, Timm; Beckmann, Felix; Herzen, Julia; Lobrinus, Johannes A.; Montecucco, Fabrizio; Mach, François; Zumbuehl, Andreas; Saxer, Till; Müller, Bert

    2012-10-01

    Atherosclerosis, the narrowing of vessel diameter and build-up of plaques in coronary arteries, leads to an increase in the shear stresses present, which can be used as a physics-based trigger for targeted drug delivery. In order to develop appropriate nanometer-size containers, one has to know the morphology of the critical stenoses with isotropic micrometer resolution. Micro computed tomography in absorption and phase contrast mode provides the necessary spatial resolution and contrast. The present communication describes the pros and cons of the conventional and synchrotron radiation-based approaches in the visualization of diseased human and murine arteries. Using registered datasets, it also demonstrates that multi-modal imaging, including established histology, is even more powerful. The tomography data were evaluated with respect to cross-section, vessel radius and maximal constriction. The average cross-section of the diseased human artery (2.31 mm2) was almost an order of magnitude larger than the murine one (0.27 mm2), whereas the minimal radius differs only by a factor of two (0.51 mm versus 0.24 mm). The maximal constriction, however, was much larger for the human specimen (85% versus 49%). We could also show that a plastic model used for recent experiments in targeted drug delivery represents a very similar morphology, which is, for example, characterized by a maximal constriction of 82%. The tomography data build a sound basis for flow simulations, which allows for conclusions on shear stress distributions in stenosed blood vessels.

  14. Morphological Variation in Pratylenchus penetrans

    PubMed Central

    Tarte, Rodrigo; Mai, W. F.

    1976-01-01

    Variability of morphological characters used to separate Pratylenchus penetrans from other species of the genus was studied in a population originating from a single gravid female. Pronounced heteromorphism was observed and characterized. About 30% of females had a crenate-tail terminus. Several shapes of stylet knobs were characterized; 50% of them were anteriorly flattened to indented. The outer margin of the cephalic framework extended into the body from one-half to two annules. The shape of the spermatheca varied from round to oval. A fifth lateral line was observed in many specimens. Environmental factors, and particularly the host plant, influenced such morphometric characters as body length, width, esophagus length, stylet length, V value, a and b' ratios, as well as qualitative characters such as tail terminus, growth of ovary, and shape of median bulb. Nematodes reared on pea and cabbage had a higher percentage of females with a crenate-tail terminus than those from tomato, rye, beet, and alfalfa callus culture. Nematodes from peas were longer and wider; they often had gonads that extended to esophagi, but they had shorter esophagi amt stylets than those from callus culture. Populations from different geographical locations also exhibited variahility in morphological characters, as did the Cornell population. The validity of many characters used in species identification is discussed, and the possibility that other related Pratylenchus species are conspecific with P. penetrans is suggested. PMID:19308221

  15. Protoplanetary and Debris Disk Morphologies

    NASA Astrophysics Data System (ADS)

    Lomax, Jamie R.; Wisniewski, John P.; Grady, Carol A.; McElwain, Michael W.; Hashimoto, Jun; Donaldson, Jessica; Debes, John H.; Malumuth, Eliot; Roberge, Aki; Weinberger, Alycia J.; SEEDS Team

    2016-01-01

    The types of planets that form around other stars are highly dependent on their natal disk conditions. Therefore, the composition, morphology, and distribution of material in protoplanetary and debris disks are important for planet formation. Here we present the results of studies of two disk systems: AB Aur and AU Mic.The circumstellar disk around the Herbig Ae star AB Aur has many interesting features, including spirals, asymmetries, and non-uniformities. However, comparatively little is known about the envelope surrounding the system. Recent work by Tang et al (2012) has suggested that the observed spiral armss may not in fact be in the disk, but instead are due to areas of increased density in the envelope and projection effects. Using Monte Carlo modeling, we find that it is unlikely that the envelope holds enough material to be responsible for such features and that it is more plausible that they form from disk material. Given the likelihood that gravitational perturbations from planets cause the observed spiral morphology, we use archival H band observations of AB Aur with a baseline of 5.5 years to determine the locations of possible planets.The AU Mic debris disk also has many interesting morphological features. Because its disk is edge on, the system is an ideal candidate for color studies using coronagraphic spectroscopy. Spectra of the system were taken by placing a HST/STIS long slit parallel to and overlapping the disk while blocking out the central star with an occulting fiducial bar. Color gradients may reveal the chemical processing that is occuring within the disk. In addition, it may trace the potential composition and architecture of any planetary bodies in the system because collisional break up of planetesimals produces the observed dust in the system. We present the resulting optical reflected spectra (5200 to 10,200 angstroms) from this procedure at several disk locations. We find that the disk is bluest at the innermost locations of the

  16. Tissue channel morphology in Octopus.

    PubMed

    Browning, J; Casley-Smith, J R

    1981-01-01

    The morphology of tissue channels in muscle and neural tissues of Octopus was investigated, at the ultrastructural level, with a technique involving the precipitation of ferrocyanide ions. The numbers, sizes and conductivities of the channels were estimated from quantitative data. No evidence was gained to indicate that the low microvascular density in Octopus is coupled to an especially extensive network of extravascular channels. The tissue channel system in Octopus appears to be broadly comparable with the mammalian system; a lack of information prevents more appropriate comparisons with marine fishes. Probable functions of tissue channels in Octopus and mammals, and reasons for apparent similarities and differences in the channel organization of these divergent groups, are discussed.

  17. Morphological study of penumbral formation

    NASA Astrophysics Data System (ADS)

    Kitai, Reizaburo; Watanabe, Hiroko; Otsuji, Ken'ichi

    2014-12-01

    Penumbrae are known to be areas of mainly horizontal magnetic field surrounding umbrae of relatively large and mature sunspots. In this paper, we observationally studied the formation of penumbrae in NOAA 10978, where several penumbral formations were observed in G-band images of the Solar Optical Telescope on board Hinode. Thanks to the continuous observation by Hinode, we could morphologically follow the evolution of sunspots and found that there are several paths to the penumbral formation: (1) active accumulation of magnetic flux, (2) rapid emergence of magnetic field, and (3) appearance of twisted or rotating magnetic tubes. In all of these cases, magnetic fields are expected to sustain high inclination at the edges of flux tube concentration longer than the characteristic growth time of downward magnetic pumping.

  18. Dielectric inspection of erythrocyte morphology

    NASA Astrophysics Data System (ADS)

    Hayashi, Yoshihito; Oshige, Ikuya; Katsumoto, Yoichi; Omori, Shinji; Yasuda, Akio; Asami, Koji

    2008-05-01

    We performed a systematic study of the sensitivity of dielectric spectroscopy to erythrocyte morphology. Namely, rabbit erythrocytes of four different shapes were prepared by precisely controlling the pH of the suspending medium, and their complex permittivities over the frequency range from 0.1 to 110 MHz were measured and analyzed. Their quantitative analysis shows that the characteristic frequency and the broadening parameter of the dielectric relaxation of interfacial polarization are highly specific to the erythrocyte shape, while they are insensitive to the cell volume fraction. Therefore, these two dielectric parameters can be used to differentiate erythrocytes of different shapes, if dielectric spectroscopy is applied to flow-cytometric inspection of single blood cells. In addition, we revealed the applicability and limitations of the analytical theory of interfacial polarization to explain the experimental permittivities of non-spherical erythrocytes.

  19. Morphological docking of secretory vesicles

    PubMed Central

    2010-01-01

    Calcium-dependent secretion of neurotransmitters and hormones is essential for brain function and neuroendocrine-signaling. Prior to exocytosis, neurotransmitter-containing vesicles dock to the target membrane. In electron micrographs of neurons and neuroendocrine cells, like chromaffin cells many synaptic vesicles (SVs) and large dense-core vesicles (LDCVs) are docked. For many years the molecular identity of the morphologically docked state was unknown. Recently, we resolved the minimal docking machinery in adrenal medullary chromaffin cells using embryonic mouse model systems together with electron-microscopic analyses and also found that docking is controlled by the sub-membrane filamentous (F-)actin. Currently it is unclear if the same docking machinery operates in synapses. Here, I will review our docking assay that led to the identification of the LDCV docking machinery in chromaffin cells and also discuss whether identical docking proteins are required for SV docking in synapses. PMID:20577884

  20. Surface morphology of erbium silicide

    NASA Technical Reports Server (NTRS)

    Lau, S. S.; Pai, C. S.; Wu, C. S.; Kuech, T. F.; Liu, B. X.

    1982-01-01

    The surface of rare-earth silicides (Er, Tb, etc.), formed by the reaction of thin-film metal layers with a silicon substrate, is typically dominated by deep penetrating, regularly shaped pits. These pits may have a detrimental effect on the electronic performance of low Schottky barrier height diodes utilizing such silicides on n-type Si. This study suggests that contamination at the metal-Si or silicide-Si interface is the primary cause of surface pitting. Surface pits may be reduced in density or eliminated entirely through either the use of Si substrate surfaces prepared under ultrahigh vacuum conditions prior to metal deposition and silicide formation or by means of ion irradiation techniques. Silicide layers formed by these techniques possess an almost planar morphology.

  1. Internal morphology of human phalanges.

    PubMed

    Schulter-Ellis, F P; Lazar, G T

    1984-07-01

    The internal morphology of human phalanges has been defined by measurements taken directly from specimens of these bones. For this study, all 14 phalanges were prepared from 25 fresh cadaver hands. Measurements were taken of both external and internal variables. Intramedullary structures are described. In the proximal metaphysis of the phalanges, the canal presents the shape of a tunnel with a flat floor on its palmar aspect and an arching roof dorsally. Distally, toward middiaphysis, the canal becomes more elliptic and its size is smaller relative to the metaphyseal area. This suggests that not only dimensions but also the shape of the canal should be given full consideration in the design of intramedullary devices.

  2. Open data and digital morphology.

    PubMed

    Davies, Thomas G; Rahman, Imran A; Lautenschlager, Stephan; Cunningham, John A; Asher, Robert J; Barrett, Paul M; Bates, Karl T; Bengtson, Stefan; Benson, Roger B J; Boyer, Doug M; Braga, José; Bright, Jen A; Claessens, Leon P A M; Cox, Philip G; Dong, Xi-Ping; Evans, Alistair R; Falkingham, Peter L; Friedman, Matt; Garwood, Russell J; Goswami, Anjali; Hutchinson, John R; Jeffery, Nathan S; Johanson, Zerina; Lebrun, Renaud; Martínez-Pérez, Carlos; Marugán-Lobón, Jesús; O'Higgins, Paul M; Metscher, Brian; Orliac, Maëva; Rowe, Timothy B; Rücklin, Martin; Sánchez-Villagra, Marcelo R; Shubin, Neil H; Smith, Selena Y; Starck, J Matthias; Stringer, Chris; Summers, Adam P; Sutton, Mark D; Walsh, Stig A; Weisbecker, Vera; Witmer, Lawrence M; Wroe, Stephen; Yin, Zongjun; Rayfield, Emily J; Donoghue, Philip C J

    2017-04-12

    Over the past two decades, the development of methods for visualizing and analysing specimens digitally, in three and even four dimensions, has transformed the study of living and fossil organisms. However, the initial promise that the widespread application of such methods would facilitate access to the underlying digital data has not been fully achieved. The underlying datasets for many published studies are not readily or freely available, introducing a barrier to verification and reproducibility, and the reuse of data. There is no current agreement or policy on the amount and type of data that should be made available alongside studies that use, and in some cases are wholly reliant on, digital morphology. Here, we propose a set of recommendations for minimum standards and additional best practice for three-dimensional digital data publication, and review the issues around data storage, management and accessibility.

  3. The morphological evolution of galaxies.

    PubMed

    Abraham, R G; van Den Bergh, S

    2001-08-17

    Many galaxies have taken on their familiar appearance relatively recently. In the distant Universe, galaxy morphology deviates significantly (and systematically) from that of nearby galaxies at redshifts (z) as low as 0.3. This corresponds to a time approximately 3.5 x 10(9) years in the past, which is only approximately 25% of the present age of the Universe. Beyond z = 0.5 (5 x 10(9) years in the past), spiral arms are less well developed and more chaotic, and barred spiral galaxies may become rarer. At z = 1, around 30% of the galaxy population is sufficiently peculiar that classification on Hubble's traditional "tuning fork" system is meaningless. On the other hand, some characteristics of galaxies have not changed much over time. The space density of luminous disk galaxies has not changed significantly since z = 1, indicating that although the general appearance of these galaxies has continuously changed over time, their overall numbers have been conserved.

  4. Molecular control of facial morphology

    PubMed Central

    Liu, B.; Rooker, S.M.; Helms, J.A.

    2010-01-01

    We present a developmental perspective on the concept of phylotypic and phenotypic stages of craniofacial development. Within Orders of avians and mammals, a phylotypic period exists when the morphology of the facial prominences is minimally divergent. We postulate that species-specific facial variations arise as a result of subtle shifts in the timing and the duration of molecular pathway activity (e.g., heterochrony), and present evidence demonstrating a critical role for Wnt and FGF signaling in this process. The same molecular pathways that shape the vertebrate face are also implicated in craniofacial deformities, indicating that comparisons between and among animal species may represent a novel method for the identification of human craniofacial disease genes. PMID:19747977

  5. Morphological study of semicrystalline polymers

    NASA Astrophysics Data System (ADS)

    Rane, Shrish Yashwant

    1999-10-01

    This dissertation addresses several unresolved issues pertaining to the morphology of semi-crystalline polymers. The morphology of the simpler semi-crystalline polymers such as, polyethylene (PE) has been well characterized in the literature. Still large gaps exist in the quantitative understanding of the lamellar in the spherulites of these polymers. The intermediate regime between the lamellae and spherulites is still largely unexplored. Further information on this regime will enhance the establishment of vital structure-property relationships in commercially blown PE films. The lamellae may follow fractal scaling laws as they grow from the nucleus to form the spherulite. This mesoscale structure will be investigated by ultra low small angle (Bonse-Hart) scattering. Variables such as the orientation imported during processing and the branch content the effect the macro-properties of the finished polymer product. In the past the orientation of molecular chains has been studied by several authors using diffraction, birefringence and spectroscopic measurements. In this study the orientation of the lamellae will be quantified using small angle x-ray scattering and an attempt will be made to correlate the orientation to properties such as permeability and machine direction tear strength in blown films of commercial grades of high density polyethylene (HDPE), linear low density polyethylene (LLDPE) and the newer metallocene resins. The origin and cause of spherulitic banding in semi-crystalline polymers remains another mystery. The classical formalisms of lamellar banding by Keith and Padden which attribute it to the regular twisting of lamellae are not universal and fail to explain the bands present in other materials such as agates, where there is no evidence of lamellar structures. The phenomena of lamellar banding will be studied in bio-polyester systems, which exhibit distinct, well developed banded spherulites. The effect of copolymerization and thermal

  6. Tropical deep convective cloud morphology

    NASA Astrophysics Data System (ADS)

    Igel, Matthew R.

    integrated to form a more comprehensive theory for deep convective anvil responses to SST. An investigation into the physical shape and size of mature, oceanic, tropical, deep convective clouds is conducted. Mean cloud objects are discussed. For single-core clouds, the mean cloud has an anvil width of 95 km, a pedestal width of 11 km, and an anvil thickness of 6.4 km. The number of identified convective cores within pedestal correlates well with certain length scales and morphological attributes of cloud objects. As the number of cores increases, so does the size of the mean cloud object. Pedestal width is shown to regress linearly to anvil width when a 2/3rd power scaling is applied to pedestal width. This result implies continuous but retarded growth of anvils with growing pedestals and equivalence in the mass flux convecting through the pedestal and into the anvil. Trends in cloud scales with cloud base and top heights are investigated to shed light on related convective parameterization assumptions and on convective transport, respectively. Many of the results obtained using the CloudSat methodology are also examined with a large-domain radiative-convective equilibrium numerical simulation and are found to exhibit similar trends when modeled. Finally, various CloudSat sampling issues are discussed in several appendices. Utilizing the CloudSat cloud object database, an examination of the sensitivity of oceanic, mature, deep convective cloud morphology to environmental characteristics is conducted. Convective available potential energy (CAPE), aerosol optical depth, mid-level vertical velocity, and troposphere deep shear are all included as meteorological measures. The sensitivity of various aspects of convective morphology to each one of these environmental characteristics is assessed individually. The results demonstrate that clouds tend to be invigorated by higher CAPE, aerosol amount, and upward mid-level vertical velocity. Stronger shear tends to make clouds wider but

  7. Sarcocystis in moose (Alces alces): molecular identification and phylogeny of six Sarcocystis species in moose, and a morphological description of three new species.

    PubMed

    Dahlgren, Stina S; Gjerde, Bjørn

    2008-06-01

    Muscle tissues from 34 moose from Southeastern Norway and two moose from Canada were examined. Sarcocysts were excised and morphologically classified by light microscopy, and some cysts were further examined by scanning electron microscopy or DNA amplification and sequencing at the small subunit (ssu) rRNA gene. In Norwegian moose, three sarcocyst types were recognized, yet five Sarcocystis species were found by sequence analysis. New names were proposed for three species which could be characterised by both morphological and molecular methods, i.e., Sarcocystis alces, Sarcocystis ovalis, and Sarcocystis scandinavica. S. alces was the most prevalent species, whereas S. scandinavica and the two unnamed species were rare and might either use another principal intermediate host or a rare definitive host. The five species in Norwegian moose were different from Sarcocystis alceslatrans isolated from a Canadian moose. Phylogenetic analyses based on complete ssu rRNA gene sequences revealed a close relationship between the six Sarcocystis species from moose and species from reindeer and Sika deer. We conclude that molecular methods are necessary for unequivocal species identification, as different cervid hosts harbour morphologically indistinguishable sarcocysts.

  8. Edge enhanced morphology for infrared image analysis

    NASA Astrophysics Data System (ADS)

    Bai, Xiangzhi; Liu, Haonan

    2017-01-01

    Edge information is one of the critical information for infrared images. Morphological operators have been widely used for infrared image analysis. However, the edge information in infrared image is weak and the morphological operators could not well utilize the edge information of infrared images. To strengthen the edge information in morphological operators, the edge enhanced morphology is proposed in this paper. Firstly, the edge enhanced dilation and erosion operators are given and analyzed. Secondly, the pseudo operators which are derived from the edge enhanced dilation and erosion operators are defined. Finally, the applications for infrared image analysis are shown to verify the effectiveness of the proposed edge enhanced morphological operators. The proposed edge enhanced morphological operators are useful for the applications related to edge features, which could be extended to wide area of applications.

  9. THE PARADOX OF SIGN LANGUAGE MORPHOLOGY

    PubMed Central

    Aronoff, Mark; Meir, Irit; Sandler, Wendy

    2011-01-01

    Sign languages have two strikingly different kinds of morphological structure: sequential and simultaneous. The simultaneous morphology of two unrelated sign languages, American and Israeli Sign Language, is very similar and is largely inflectional, while what little sequential morphology we have found differs significantly and is derivational. We show that at least two pervasive types of inflectional morphology, verb agreement and classifier constructions, are iconically grounded in spatiotemporal cognition, while the sequential patterns can be traced to normal historical development. We attribute the paucity of sequential morphology in sign languages to their youth. This research both brings sign languages much closer to spoken languages in their morphological structure and shows how the medium of communication contributes to the structure of languages.* PMID:22223926

  10. Recent Advances in Morphological Cell Image Analysis

    PubMed Central

    Chen, Shengyong; Zhao, Mingzhu; Wu, Guang; Yao, Chunyan; Zhang, Jianwei

    2012-01-01

    This paper summarizes the recent advances in image processing methods for morphological cell analysis. The topic of morphological analysis has received much attention with the increasing demands in both bioinformatics and biomedical applications. Among many factors that affect the diagnosis of a disease, morphological cell analysis and statistics have made great contributions to results and effects for a doctor. Morphological cell analysis finds the cellar shape, cellar regularity, classification, statistics, diagnosis, and so forth. In the last 20 years, about 1000 publications have reported the use of morphological cell analysis in biomedical research. Relevant solutions encompass a rather wide application area, such as cell clumps segmentation, morphological characteristics extraction, 3D reconstruction, abnormal cells identification, and statistical analysis. These reports are summarized in this paper to enable easy referral to suitable methods for practical solutions. Representative contributions and future research trends are also addressed. PMID:22272215

  11. The Limits on Trypanosomatid Morphological Diversity

    PubMed Central

    Wheeler, Richard John; Gluenz, Eva; Gull, Keith

    2013-01-01

    Cell shape is one, often overlooked, way in which protozoan parasites have adapted to a variety of host and vector environments and directional transmissions between these environments. Consequently, different parasite life cycle stages have characteristic morphologies. Trypanosomatid parasites are an excellent example of this in which large morphological variations between species and life cycle stage occur, despite sharing well-conserved cytoskeletal and membranous structures. Here, using previously published reports in the literature of the morphology of 248 isolates of trypanosomatid species from different hosts, we perform a meta-analysis of the occurrence and limits on morphological diversity of different classes of trypanosomatid morphology (trypomastigote, promastigote, etc.) in the vertebrate bloodstream and invertebrate gut environments. We identified several limits on cell body length, cell body width and flagellum length diversity which can be interpreted as biomechanical limits on the capacity of the cell to attain particular dimensions. These limits differed for morphologies with and without a laterally attached flagellum which we suggest represent two morphological superclasses, the ‘juxtaform’ and ‘liberform’ superclasses. Further limits were identified consistent with a selective pressure from the mechanical properties of the vertebrate bloodstream environment; trypanosomatid size showed limits relative to host erythrocyte dimensions. This is the first comprehensive analysis of the limits of morphological diversity in any protozoan parasite, revealing the morphogenetic constraints and extrinsic selection pressures associated with the full diversity of trypanosomatid morphology. PMID:24260255

  12. Molecular and morphological differentiation of two similar species of Accacoeliidae (Digenea): Accacladocoelium macrocotyle and A. nigroflavum from sunfish, Mola mola.

    PubMed

    Ahuir-Baraja, A E; Fraija-Fernández, N; Raga, J A; Montero, F E

    2015-04-01

    In a study of 106 sunfish, Mola mola (L.), from Mediterranean waters, 2,731 worms, belonging to 2 congeneric species of accacoeliids, Accacladocoelium macrocotyle (Diesing, 1858) Robinson, 1934 and Accacladocoelium nigroflavum (Rudolphi, 1819) Robinson, 1934 , were collected from the digestive system. It is often difficult to differentiate between these 2 species as they are sympatric and very similar; in fact, according to previous descriptions, the extent of the vitellarium is the only interspecific difference, described as extending posteriorly to the ovary in A. macrocotyle and as anterior to the anterior testis in A. nigroflavum. However, this diagnostic trait is not always valid; moreover, it is often indistinguishable because it is masked by the uterine eggs. Here, the morphology of new specimens of both species has been studied in detail and combined with molecular analysis. This study shows that the extension of the vitellarium is very similar in both species, but the degree of ramification differs. Furthermore, although the morphological differences are very slight, both species seemed genetically different: intraspecific differences ranged between 0.8 and 1.5% in internal transcribed spacer (ITS)-2 rRNA gene (ITS2) and between 0.5 and 1.6% in cytochrome c oxidase subunit 1 (COI) and interspecific differences ranged between 2 and 3.2% in ITS2 and between 9.6 and 10.6% in COI. In addition, we observed previously undescribed morphological differences, which help to differentiate these 2 species: the oral sucker is relatively smaller in A. nigroflavum than in A. macrocotyle and the ovary is usually relatively longer in A. nigroflavum than in A. macrocotyle.

  13. North American sturgeon otolith morphology

    USGS Publications Warehouse

    Chalupnicki, Marc A.; Dittman, Dawn E.

    2016-01-01

    Accurate expedient species identification of deceased sturgeon (Acipenseridae) when external physical characteristic analysis is inconclusive has become a high priority due to the endangered or threatened status of sturgeon species around the world. Examination of otoliths has provided useful information to aid in population management, age and size-class analysis, understanding predator–prey interactions, and archeological research in other fish species. The relationship between otolith characteristics and sturgeon species has remained unknown. Therefore, we analyzed the shape of otoliths from the eight species of sturgeon found in North America to test the utility of otolith characteristic morphology in species identification. There were distinct differences in the size and shape of the otoliths between species of sturgeon with little shape variation among individuals of the same species. The relationship between otolith length axes was linear, and most of the variability was explained by a Log (axis + 1) transformation of the x and y axes (r2 = 0.8983) using the equation y = 0.73x + 0.0612. Images of otoliths from all eight North American species are presented to assist in the identification process.

  14. Clinorotation affects soybean seedling morphology.

    PubMed

    Hilaire, E; Guikema, J A; Brown, C S

    1995-01-01

    Although spaceflight does not appear to significantly affect seed germination, it can influence subsequent plant growth. On STS-3 and SL-2, decreased growth (measured as plant length, fresh weight and dry weight) was noted for pine, oat and mung bean. In the CHROMEX-01 and -02 experiments with Haplopappus and in the CHROMEX-03 experiment with Arabidopsis, enhanced root growth was noted in the space-grown plants. In the CHROMEX-04 experiment with wheat, both leaf fresh weight and leaf area were diminished in the space-grown plants but there was no difference in total plant height (CS Brown, HG Levine, and AD Krikorian, unpublished data). These data suggest that microgravity impacts growth by whole plant partitioning of assimilates. The objective of the present study was to determine the influence of clinorotation on the growth and morphology of soybean seedlings grown in the BRIC (Biological Research In Canister) flight hardware. This experiment provided baseline data for a spaceflight experiment (BRIC-03) flown on STS-63 (Feb. 3-11, 1995).

  15. Platelets: production, morphology and ultrastructure.

    PubMed

    Thon, Jonathan N; Italiano, Joseph E

    2012-01-01

    Platelets are anucleate, discoid cells, roughly 2-3 μm in diameter that function primarily as regulators of hemostasis, but also play secondary roles in angiogensis and innate immunity. Although human adults contain nearly one trillion platelets in circulation that are turned over every 8-10 days, our understanding of the mechanisms involved in platelet production is still incomplete. Platelets stem from large (30-100 μm) nucleated cells called megakaryocytes that reside primarily in the bone marrow. During maturation megakaryocytes extend long proplatelet elongations into sinusoidal blood vessels from which platelets ultimately release. During this process, platelets develop a number of distinguishable structural elements including: a delimited plasma membrane; invaginations of the surface membrane that form the open canalicular system (OCS); a closed-channel network of residual endoplasmic reticulum that form the dense tubular system (DTS); a spectrin-based membrane skeleton; an actin-based cytoskeletal network; a peripheral band of microtubules; and numerous organelles including α-granules, dense-granules, peroxisomes, lysosomes, and mitochondria. Proplatelet elongation and platelet production is an elaborate and complex process that defines the morphology and ultrastructure of circulating platelets, and is critical in understanding their increasingly numerous and varied biological functions.

  16. Morphology Controls on Calcite Recrystallization.

    PubMed

    Heberling, Frank; Paulig, Leonie; Nie, Zhe; Schild, Dieter; Finck, Nicolas

    2016-11-01

    Environmental scientists and geoscientists working in different fields regard the reactivity of calcite and corresponding changes in its trace elemental- or isotopic composition from diametrically opposed points of view. As one extreme, calcite based environmental remediation strategies rely on the fast recrystallization of calcite and the concurrent uptake and immobilization of pollutants. Paleo-ecological investigations denote the other extreme, and rely on the invariability of calcite composition over geological periods of time. We use long-term radiotracer experiments to quantify recrystallization rates of seven types of calcite powder with diverse morphology and particle size distribution. On the one hand our results demonstrate the long-term metastability of calcite with equilibrated crystal surfaces even at isotopic dis-equilibrium. On the other hand, we document the extremely high reactivity and interfacial free energy of freshly ground, rough calcite. Our results indicate that bulk calcite recrystallization is an interfacial free energy driven Ostwald-ripening process, in which particle roughness effects dominate over the effect of crystal habitus and particle size. We confirm that the dynamic equilibrium exchange of crystal constituents between kink sites involves an activation barrier of about 25 kJ/mol. At room temperature the equilibrium exchange is limited to a near surface region and proceeds at a rate of (3.6 ± 1.4)·10(-13) mol/(m(2)·s).

  17. Clinorotation affects soybean seedling morphology

    NASA Technical Reports Server (NTRS)

    Hilaire, Emmanuel; Guikema, James A.; Brown, Christopher S.

    1995-01-01

    Although spaceflight does not appear to significantly affect seed germination, it can influence subsequent plant growth. On STS-3 and SL-2, decreased growth (measured as plant length, fresh weight, and dry weight) was noted for pine, oat, and mung bean. In the CHROMEX-01 and 02 experiments with Haplopappus and in the CHROMEX-03 experiment with Arabidopsis, enhanced root growth was noted in the space-grown plants. In the CHROMEX-04 experiments with wheat, both leaf fresh weight and leaf area were diminished in the space-grown plants but there was no difference in total plant height (CS Brown, HG Levine, and AD Krikorian, unpublished data). These data suggest that microgravity impacts growth by whole plant partitioning of the assimilates. The objective of the present study was to determine the influence of clinorotation on the growth and the morphology of soybean seedlings grown in the Biological Research In Canister (BRIC) flight hardware. This experiment provided baseline data for a spaceflight experiment (BRIC-3) flown on STS-63 (February 3-11, 1995).

  18. Morphological Decomposition in Reading Hebrew Homographs

    ERIC Educational Resources Information Center

    Miller, Paul; Liran-Hazan, Batel; Vaknin, Vered

    2016-01-01

    The present work investigates whether and how morphological decomposition processes bias the reading of Hebrew heterophonic homographs, i.e., unique orthographic patterns that are associated with two separate phonological, semantic entities depicted by means of two morphological structures (linear and nonlinear). In order to reveal the nature of…

  19. Accurate sperm morphology assessment predicts sperm function.

    PubMed

    Abu Hassan Abu, D; Franken, D R; Hoffman, B; Henkel, R

    2012-05-01

    Sperm morphology has been associated with in vitro as well as in vivo fertilisation. The study aimed to evaluate the possible relation between the percentage of spermatozoa with normal morphology and the following sperm functional assays: (i) zona-induced acrosome reaction (ZIAR); (ii) DNA integrity; (iii) chromatin condensation; (iv) sperm apoptosis; and (v) fertilisation rates. Regression analysis was employed to calculate the association between morphology and different functional tests. Normal sperm morphology correlated significantly with the percentages of live acrosome-reacted spermatozoa in the ZIAR (r = 0.518; P < 0.0001; n = 92), DNA integrity (r = -0.515; P = 0.0018; n = 34), CMA(3) -positive spermatozoa (r = -0.745; P < 0.0001; n = 92), sperm apoptosis (r = -0.395; P = 0.0206; n = 34) and necrosis (r = -0.545; P = 0.0009; n = 34). Negative correlations existed between for the acrosome reaction, and DNA integrity, while negative associations were recorded with the percentages of CMA(3) -positive spermatozoa, apoptotic and necrotic spermatozoa. Sperm morphology is related to sperm dysfunction such as poor chromatin condensation, acrosome reaction and DNA integrity. Negative and significant correlations existed between normal sperm morphology and chromatin condensation, the percentage of spermatozoa with abnormal DNA and spermatozoa with apoptotic activity. The authors do not regard sperm morphology as the only test for the diagnosis of male fertility, but sperm morphology can serve as a valuable indicator of underlying dysfunction.

  20. Effects of Morphological Instruction on Vocabulary Acquisition

    ERIC Educational Resources Information Center

    Bowers, Peter N.; Kirby, John R.

    2010-01-01

    The effects of a 20-session intervention targeting morphological word structure on vocabulary knowledge were investigated in four Grade 4 and 5 classes, assigned randomly to treatment and control conditions. Hierarchical regression analyses controlling for initial vocabulary showed significant instructional effects on morphological analysis and…

  1. Lexical Morphology: Structure, Process, and Development

    ERIC Educational Resources Information Center

    Jarmulowicz, Linda; Taran, Valentina L.

    2013-01-01

    Recent work has demonstrated the importance of derivational morphology to later language development and has led to a consensus that derivation is a lexical process. In this review, derivational morphology is discussed in terms of lexical representation models from both linguistic and psycholinguistic perspectives. Input characteristics, including…

  2. Arabic Morphology in the Neural Language System

    ERIC Educational Resources Information Center

    Boudelaa, Sami; Pulvermuller, Friedemann; Hauk, Olaf; Shtyrov, Yury; Marslen-Wilson, William

    2010-01-01

    There are two views about morphology, the aspect of language concerned with the internal structure of words. One view holds that morphology is a domain of knowledge with a specific type of neurocognitive representation supported by specific brain mechanisms lateralized to left fronto-temporal cortex. The alternate view characterizes morphological…

  3. Genetic topography of brain morphology

    PubMed Central

    Chen, Chi-Hua; Fiecas, Mark; Gutiérrez, E. D.; Panizzon, Matthew S.; Eyler, Lisa T.; Vuoksimaa, Eero; Thompson, Wesley K.; Fennema-Notestine, Christine; Hagler, Donald J.; Jernigan, Terry L.; Neale, Michael C.; Franz, Carol E.; Lyons, Michael J.; Fischl, Bruce; Tsuang, Ming T.; Dale, Anders M.; Kremen, William S.

    2013-01-01

    Animal data show that cortical development is initially patterned by genetic gradients largely along three orthogonal axes. We previously reported differences in genetic influences on cortical surface area along an anterior-posterior axis using neuroimaging data of adult human twins. Here, we demonstrate differences in genetic influences on cortical thickness along a dorsal-ventral axis in the same cohort. The phenomenon of orthogonal gradations in cortical organization evident in different structural and functional properties may originate from genetic gradients. Another emerging theme of cortical patterning is that patterns of genetic influences recapitulate the spatial topography of the cortex within hemispheres. The genetic patterning of both cortical thickness and surface area corresponds to cortical functional specializations. Intriguingly, in contrast to broad similarities in genetic patterning, two sets of analyses distinguish cortical thickness and surface area genetically. First, genetic contributions to cortical thickness and surface area are largely distinct; there is very little genetic correlation (i.e., shared genetic influences) between them. Second, organizing principles among genetically defined regions differ between thickness and surface area. Examining the structure of the genetic similarity matrix among clusters revealed that, whereas surface area clusters showed great genetic proximity with clusters from the same lobe, thickness clusters appear to have close genetic relatedness with clusters that have similar maturational timing. The discrepancies are in line with evidence that the two traits follow different mechanisms in neurodevelopment. Our findings highlight the complexity of genetic influences on cortical morphology and provide a glimpse into emerging principles of genetic organization of the cortex. PMID:24082094

  4. Morphological, Biochemical, and Functional Study of Viral Replication Compartments Isolated from Adenovirus-Infected Cells

    PubMed Central

    Hidalgo, Paloma; Anzures, Lourdes; Hernández-Mendoza, Armando; Guerrero, Adán; Wood, Christopher D.; Valdés, Margarita; Dobner, Thomas

    2016-01-01

    ABSTRACT Adenovirus (Ad) replication compartments (RC) are nuclear microenvironments where the viral genome is replicated and a coordinated program of late gene expression is established. These virus-induced nuclear sites seem to behave as central hubs for the regulation of virus-host cell interactions, since proteins that promote efficient viral replication as well as factors that participate in the antiviral response are coopted and concentrated there. To gain further insight into the activities of viral RC, here we report, for the first time, the morphology, composition, and activities of RC isolated from Ad-infected cells. Morphological analyses of isolated RC particles by superresolution microscopy showed that they were indistinguishable from RC within infected cells and that they displayed a dynamic compartmentalization. Furthermore, the RC-containing fractions (RCf) proved to be functional, as they directed de novo synthesis of viral DNA and RNA as well as RNA splicing, activities that are associated with RC in vivo. A detailed analysis of the production of viral late mRNA from RCf at different times postinfection revealed that viral mRNA splicing occurs in RC and that the synthesis, posttranscriptional processing, and release from RC to the nucleoplasm of individual viral late transcripts are spatiotemporally separate events. The results presented here demonstrate that RCf are a powerful system for detailed study into RC structure, composition, and activities and, as a result, the determination of the molecular mechanisms that induce the formation of these viral sites of adenoviruses and other nuclear-replicating viruses. IMPORTANCE RC may represent molecular hubs where many aspects of virus-host cell interaction are controlled. Here, we show by superresolution microscopy that RCf have morphologies similar to those of RC within Ad-infected cells and that they appear to be compartmentalized, as nucleolin and DBP display different localization in the

  5. The Relationship between Morphological Awareness and Morphological Decomposition among English Language Learners

    ERIC Educational Resources Information Center

    Kraut, Rachel

    2015-01-01

    Morphological awareness facilitates many reading processes. For this reason, L1 and L2 learners of English are often directly taught to use their knowledge of English morphology as a useful reading strategy for determining parts of speech and meaning of novel words. Over time, use of morphological awareness skills while reading develops into an…

  6. The Contribution of Morphological Awareness to the Spelling of Morphemes and Morphologically Complex Words in French

    ERIC Educational Resources Information Center

    Fejzo, Anila

    2016-01-01

    The goal of this study was to explore the relationship between morphological awareness and the spelling of morphemes and morphologically complex words among 75 third- and fourth-grade Francophone students of low socio-economic status. To reach this objective, we administered a dictation comprised of morphologically complex words with prefixes,…

  7. Morphological and molecular convergences in mammalian phylogenetics.

    PubMed

    Zou, Zhengting; Zhang, Jianzhi

    2016-09-02

    Phylogenetic trees reconstructed from molecular sequences are often considered more reliable than those reconstructed from morphological characters, in part because convergent evolution, which confounds phylogenetic reconstruction, is believed to be rarer for molecular sequences than for morphologies. However, neither the validity of this belief nor its underlying cause is known. Here comparing thousands of characters of each type that have been used for inferring the phylogeny of mammals, we find that on average morphological characters indeed experience much more convergences than amino acid sites, but this disparity is explained by fewer states per character rather than an intrinsically higher susceptibility to convergence for morphologies than sequences. We show by computer simulation and actual data analysis that a simple method for identifying and removing convergence-prone characters improves phylogenetic accuracy, potentially enabling, when necessary, the inclusion of morphologies and hence fossils for reliable tree inference.

  8. Morphological and molecular convergences in mammalian phylogenetics

    PubMed Central

    Zou, Zhengting; Zhang, Jianzhi

    2016-01-01

    Phylogenetic trees reconstructed from molecular sequences are often considered more reliable than those reconstructed from morphological characters, in part because convergent evolution, which confounds phylogenetic reconstruction, is believed to be rarer for molecular sequences than for morphologies. However, neither the validity of this belief nor its underlying cause is known. Here comparing thousands of characters of each type that have been used for inferring the phylogeny of mammals, we find that on average morphological characters indeed experience much more convergences than amino acid sites, but this disparity is explained by fewer states per character rather than an intrinsically higher susceptibility to convergence for morphologies than sequences. We show by computer simulation and actual data analysis that a simple method for identifying and removing convergence-prone characters improves phylogenetic accuracy, potentially enabling, when necessary, the inclusion of morphologies and hence fossils for reliable tree inference. PMID:27585543

  9. Predicting vegetation-stabilized dune field morphology

    NASA Astrophysics Data System (ADS)

    Barchyn, Thomas E.; Hugenholtz, Chris H.

    2012-09-01

    The morphology of vegetation-stabilized dune fields on the North American Great Plains (NAGP) mostly comprises parabolic dunes; stabilized barchan and transverse dunes are rare, with the exception of transverse and barchan mega-dunes in the Nebraska Sand Hills. We present a hypothesis from a numerical dune field model explaining the vegetation-stabilized morphology of dunes under unidirectional wind. Simulations with a range of initial dune morphologies (closely-spaced transverse to disperse barchans) indicate that stabilized morphology is determined by the ratio of slipface deposition rate to deposition tolerance of vegetation. Slipface deposition rate is related to dune height, flux, and celerity. With a fixed depositional tolerance, large, slow-moving dunes have low slipface deposition rates and ‘freeze’ in place once vegetation is introduced. Relatively small, fast dunes have high slipface deposition rates and evolve into parabolic dunes, often colliding during stabilization. Our hypothesis could explain differences in stabilized morphology across the NAGP and elsewhere.

  10. Growth morphology with anisotropic surface kinetics

    NASA Technical Reports Server (NTRS)

    Xiao, Rong-Fu; Alexander, J. Iwan D.; Rosenberger, Franz

    1990-01-01

    The morphological evolution of crystals growing from an incongruent vapor phase is studied using a Monte Carlo model, and the full range of growth morphologies is recovered. The diffusion in the bulk nutrient and the anisotropy in the interface kinetics are morphologically destabilizing and stabilizing, respectively. For a given set of simulation parameters and lattice symmetries there is a critical size, which scales linearly with the mean free path in the vapor, beyond which a crystal cannot retain its stable, macroscopically faceted growth shape. Surface diffusion stabilizes faceted growth on the shorter scale of the mean surface diffusion length. In simulations with a uniform drift superimposed on the random walk nutrient transport, crystal faces oriented toward the drift show enhanced morphological stability compared to the purely diffusive situation. Rotational drifts with periodic reversal of direction are morphologically stabilizing for all crystal facets.

  11. Effect of surface morphology on friction of graphene on various substrates

    NASA Astrophysics Data System (ADS)

    Cho, Dae-Hyun; Wang, Lei; Kim, Jin-Seon; Lee, Gwan-Hyoung; Kim, Eok Su; Lee, Sunhee; Lee, Sang Yoon; Hone, James; Lee, Changgu

    2013-03-01

    The friction of graphene on various substrates, such as SiO2, h-BN, bulk-like graphene, and mica, was investigated to characterize the adhesion level between graphene and the underlying surface. The friction of graphene on SiO2 decreased with increasing thickness and converged around the penta-layers due to incomplete contact between the two surfaces. However, the friction of graphene on an atomically flat substrate, such as h-BN or bulk-like graphene, was low and comparable to that of bulk-like graphene. In contrast, the friction of graphene folded onto bulk-like graphene was indistinguishable from that of mono-layer graphene on SiO2 despite the ultra-smoothness of bulk-like graphene. The characterization of the graphene's roughness before and after folding showed that the corrugation of graphene induced by SiO2 morphology was preserved even after it was folded onto an atomically flat substrate. In addition, graphene deposited on mica, when folded, preserved the same corrugation level as before the folding event. Our friction measurements revealed that graphene, once exfoliated from the bulk crystal, tends to maintain its corrugation level even after it is folded onto an atomically flat substrate and that ultra-flatness in both graphene and the substrate is required to achieve the intimate contact necessary for strong adhesion.The friction of graphene on various substrates, such as SiO2, h-BN, bulk-like graphene, and mica, was investigated to characterize the adhesion level between graphene and the underlying surface. The friction of graphene on SiO2 decreased with increasing thickness and converged around the penta-layers due to incomplete contact between the two surfaces. However, the friction of graphene on an atomically flat substrate, such as h-BN or bulk-like graphene, was low and comparable to that of bulk-like graphene. In contrast, the friction of graphene folded onto bulk-like graphene was indistinguishable from that of mono-layer graphene on SiO2

  12. The morphology of cometary nuclei

    NASA Astrophysics Data System (ADS)

    Keller, H. U.; Jorda, L.

    the Rosetta comet rendezvous mission) to about 50 km (comet Hale- Bopp, comet P/Schwassman-Wachmann 1). Their albedos are very low, about 0.04. Their shapes are irregular, axes ratios of 2:1 are often derived. Even though comets are characterized by their activity, in most cases only a small fraction of the nuclear surface (in some cases less than 1%) is active. An exception seems to be comet P/Wirtanen where all its surface is required to be active in order to explain its production rates (Rickman and Jorda 1998). The detection of trans-Neptunian objects (TNOs) in the Kuiper belt (Jewitt and Luu 1993) reveals a new population of cometary bodies with dimensions an order of magnitude bigger (100 km and larger) than the typical comet observed in the inner planetary system. Little is known about the extent, density, size distribution and physical characteristics of these objects. This region is supposedly the reservoir for short-period comets, manly those controlled by Jupiter (Jupiter family comets). Our present concept of a cometary nucleus has been strongly influenced by the first pictures of the nucleus of comet Halley achieved during the Giotto flyby in 1986. While this revelation seems to be confirmed as typical by modern observations it carries the danger of prototyping new observational results and inferences. Missions and spacecraft are already on their way (Deep Space, Contour, Stardust, Deep Impact) or in preparation (Rosetta) to diversify our knowledge. The morphology of cometary nuclei is determined by their formation process in the early solar nebula, their dynamics and evolution. The physics of the processes leading to their apparent activity while approaching the Sun are still obscure in many details but determine the small- and intermediate-scale morphology. The large-scale morphology, the shape, of a cometary nucleus is determined by its fragility and inner structure and by its generally complex rotational state. These topics will be reviewed in the

  13. Colony Morphology Variation of Burkholderia pseudomallei Is Associated with Antigenic Variation and O-Polysaccharide Modification

    PubMed Central

    Wikraiphat, Chanthiwa; Saiprom, Natnaree; Tandhavanant, Sarunporn; Heiss, Christian; Azadi, Parastoo; Wongsuvan, Gumphol; Tuanyok, Apichai; Holden, Matthew T. G.; Burtnick, Mary N.; Brett, Paul J.; Peacock, Sharon J.

    2015-01-01

    Burkholderia pseudomallei is a CDC tier 1 select agent that causes melioidosis, a severe disease in humans and animals. Persistent infections are common, and there is currently no vaccine available. Lipopolysaccharide (LPS) is a potential vaccine candidate. B. pseudomallei expresses three serologically distinct LPS types. The predominant O-polysaccharide (OPS) is an unbranched heteropolymer with repeating d-glucose and 6-deoxy-l-talose residues in which the 6-deoxy-l-talose residues are variably replaced with O-acetyl and O-methyl modifications. We observed that primary clinical B. pseudomallei isolates with mucoid and nonmucoid colony morphologies from the same sample expressed different antigenic types distinguishable using an LPS-specific monoclonal antibody (MAb). MAb-reactive (nonmucoid) and nonreactive (mucoid) strains from the same patient exhibited identical LPS banding patterns by silver staining and indistinguishable genotypes. We hypothesized that LPS antigenic variation reflected modification of the OPS moieties. Mutagenesis of three genes involved in LPS synthesis was performed in B. pseudomallei K96243. Loss of MAb reactivity was observed in both wbiA (encoding a 2-O-acetyltransferase) and wbiD (putative methyl transferase) mutants. The structural characteristics of the OPS moieties from isogenic nonmucoid strain 4095a and mucoid strain 4095c were further investigated. Utilizing nuclear magnetic resonance (NMR) spectroscopy, we found that B. pseudomallei 4095a and 4095c OPS antigens exhibited substitution patterns that differed from the prototypic OPS structure. Specifically, 4095a lacked 4-O-acetylation, while 4095c lacked both 4-O-acetylation and 2-O-methylation. Our studies indicate that B. pseudomallei OPS undergoes antigenic variation and suggest that the 9D5 MAb recognizes a conformational epitope that is influenced by both O-acetyl and O-methyl substitution patterns. PMID:25776750

  14. Morphological detection method with girdle structure

    NASA Astrophysics Data System (ADS)

    Chen, Yong; Yan, Gao-shi; Huo, Yu

    2013-09-01

    A flat structure element is usually used in the traditional morphological detection. In this processing method, the infrared target is regarded as a single point without considering the imaging characteristics of infrared dim and small target. There is a gray transition zone between target and background. It is unreasonable that the transition region processed as background in the traditional morphological method. So, the infrared dim target detection results are not ideal by using the traditional morphological processing method. Aimed at this problem, the imaging characteristic of infrared dim and small target is analyzed. The Spatial distribution of infrared target gray scale is calculated. The result shows it is a tip package structure. The top peak is the target. Based on theoretical research on the morphological detection, the girdle structure elements are designed. This structure is composed of two circles. The target neighborhood zones are protected in this structure. They do not participate in the morphological calculation. The sixteen external zones are only participated in the calculation. The morphology of infrared target detection method is established based on this neighborhood zoned structure. The designed girdle structure is used in the opening operation and the traditional flat structure is used in the closing operation. The traditional Top-Hat algorithm is improved according to the girdle structure morphology method. And used the real infrared target image, the improved algorithm is simulated. The processed result shows that the girdle structure morphology method is effective in the background noise restraining. In order to evaluate the image processed result quantitatively, the signal noise ratio and signal noise ratio gain factor are used. Accordingly to the calculated result, the improved algorithm compared with the traditional morphological methods, inhibition of complex background with better.

  15. Scaling laws for coastal overwash morphology

    NASA Astrophysics Data System (ADS)

    Lazarus, Eli D.

    2016-12-01

    Overwash is a physical process of coastal sediment transport driven by storm events and is essential to landscape resilience in low-lying barrier environments. This work establishes a comprehensive set of scaling laws for overwash morphology: unifying quantitative descriptions with which to compare overwash features by their morphological attributes across case examples. Such scaling laws also help relate overwash features to other morphodynamic phenomena. Here morphometric data from a physical experiment are compared with data from natural examples of overwash features. The resulting scaling relationships indicate scale invariance spanning several orders of magnitude. Furthermore, these new relationships for overwash morphology align with classic scaling laws for fluvial drainages and alluvial fans.

  16. Cascade morphology transition in bcc metals.

    PubMed

    Setyawan, Wahyu; Selby, Aaron P; Juslin, Niklas; Stoller, Roger E; Wirth, Brian D; Kurtz, Richard J

    2015-06-10

    Energetic atom collisions in solids induce shockwaves with complex morphologies. In this paper, we establish the existence of a morphological transition in such cascades. The order parameter of the morphology is defined as the exponent, b, in the defect production curve as a function of cascade energy (N(F) ~ E(MD)(b)). Response of different bcc metals can be compared in a consistent energy domain when the energy is normalized by the transition energy, μ, between the high- and the low-energy regime. Using Cr, Fe, Mo and W data, an empirical formula of μ as a function of displacement threshold energy, E(d), is presented for bcc metals.

  17. Morphological Phylogenetics in the Genomic Age.

    PubMed

    Lee, Michael S Y; Palci, Alessandro

    2015-10-05

    Evolutionary trees underpin virtually all of biology, and the wealth of new genomic data has enabled us to reconstruct them with increasing detail and confidence. While phenotypic (typically morphological) traits are becoming less important in reconstructing evolutionary trees, they still serve vital and unique roles in phylogenetics, even for living taxa for which vast amounts of genetic information are available. Morphology remains a powerful independent source of evidence for testing molecular clades, and - through fossil phenotypes - the primary means for time-scaling phylogenies. Morphological phylogenetics is therefore vital for transforming undated molecular topologies into dated evolutionary trees. However, if morphology is to be employed to its full potential, biologists need to start scrutinising phenotypes in a more objective fashion, models of phenotypic evolution need to be improved, and approaches for analysing phenotypic traits and fossils together with genomic data need to be refined.

  18. Morphological Neuron Classification Using Machine Learning.

    PubMed

    Vasques, Xavier; Vanel, Laurent; Villette, Guillaume; Cif, Laura

    2016-01-01

    Classification and quantitative characterization of neuronal morphologies from histological neuronal reconstruction is challenging since it is still unclear how to delineate a neuronal cell class and which are the best features to define them by. The morphological neuron characterization represents a primary source to address anatomical comparisons, morphometric analysis of cells, or brain modeling. The objectives of this paper are (i) to develop and integrate a pipeline that goes from morphological feature extraction to classification and (ii) to assess and compare the accuracy of machine learning algorithms to classify neuron morphologies. The algorithms were trained on 430 digitally reconstructed neurons subjectively classified into layers and/or m-types using young and/or adult development state population of the somatosensory cortex in rats. For supervised algorithms, linear discriminant analysis provided better classification results in comparison with others. For unsupervised algorithms, the affinity propagation and the Ward algorithms provided slightly better results.

  19. Morphological Neuron Classification Using Machine Learning

    PubMed Central

    Vasques, Xavier; Vanel, Laurent; Villette, Guillaume; Cif, Laura

    2016-01-01

    Classification and quantitative characterization of neuronal morphologies from histological neuronal reconstruction is challenging since it is still unclear how to delineate a neuronal cell class and which are the best features to define them by. The morphological neuron characterization represents a primary source to address anatomical comparisons, morphometric analysis of cells, or brain modeling. The objectives of this paper are (i) to develop and integrate a pipeline that goes from morphological feature extraction to classification and (ii) to assess and compare the accuracy of machine learning algorithms to classify neuron morphologies. The algorithms were trained on 430 digitally reconstructed neurons subjectively classified into layers and/or m-types using young and/or adult development state population of the somatosensory cortex in rats. For supervised algorithms, linear discriminant analysis provided better classification results in comparison with others. For unsupervised algorithms, the affinity propagation and the Ward algorithms provided slightly better results. PMID:27847467

  20. Morphological and genetic characterization of Saimiri boliviensis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The taxonomy of the genus Saimiri is controversial since morphological characters, traditionally used for identification, are insufficient to distinguish species and subspecies. Genetic studies of specimens in captivity become relevant, especially considering their frequently unknown geographical or...

  1. Genome Sequences of Eight Morphologically Diverse Alphaproteobacteria▿

    PubMed Central

    Brown, Pamela J. B.; Kysela, David T.; Buechlein, Aaron; Hemmerich, Chris; Brun, Yves V.

    2011-01-01

    The Alphaproteobacteriacomprise morphologically diverse bacteria, including many species of stalked bacteria. Here we announce the genome sequences of eight alphaproteobacteria, including the first genome sequences of species belonging to the genera Asticcacaulis, Hirschia, Hyphomicrobium, and Rhodomicrobium. PMID:21705585

  2. Genome sequences of eight morphologically diverse Alphaproteobacteria.

    PubMed

    Brown, Pamela J B; Kysela, David T; Buechlein, Aaron; Hemmerich, Chris; Brun, Yves V

    2011-09-01

    The Alphaproteobacteria comprise morphologically diverse bacteria, including many species of stalked bacteria. Here we announce the genome sequences of eight alphaproteobacteria, including the first genome sequences of species belonging to the genera Asticcacaulis, Hirschia, Hyphomicrobium, and Rhodomicrobium.

  3. Self-generated morphology in lagoon reefs.

    PubMed

    Blakeway, David; Hamblin, Michael G

    2015-01-01

    The three-dimensional form of a coral reef develops through interactions and feedbacks between its constituent organisms and their environment. Reef morphology therefore contains a potential wealth of ecological information, accessible if the relationships between morphology and ecology can be decoded. Traditionally, reef morphology has been attributed to external controls such as substrate topography or hydrodynamic influences. Little is known about inherent reef morphology in the absence of external control. Here we use reef growth simulations, based on observations in the cellular reefs of Western Australia's Houtman Abrolhos Islands, to show that reef morphology is fundamentally determined by the mechanical behaviour of the reef-building organisms themselves-specifically their tendency to either remain in place or to collapse. Reef-building organisms that tend to remain in place, such as massive and encrusting corals or coralline algae, produce nodular reefs, whereas those that tend to collapse, such as branching Acropora, produce cellular reefs. The purest reef growth forms arise in sheltered lagoons dominated by a single type of reef builder, as in the branching Acropora-dominated lagoons of the Abrolhos. In these situations reef morphology can be considered a phenotype of the predominant reef building organism. The capacity to infer coral type from reef morphology can potentially be used to identify and map specific coral habitat in remotely sensed images. More generally, identifying ecological mechanisms underlying other examples of self-generated reef morphology can potentially improve our understanding of present-day reef ecology, because any ecological process capable of shaping a reef will almost invariably be an important process in real time on the living reef.

  4. Self-generated morphology in lagoon reefs

    PubMed Central

    Hamblin, Michael G.

    2015-01-01

    The three-dimensional form of a coral reef develops through interactions and feedbacks between its constituent organisms and their environment. Reef morphology therefore contains a potential wealth of ecological information, accessible if the relationships between morphology and ecology can be decoded. Traditionally, reef morphology has been attributed to external controls such as substrate topography or hydrodynamic influences. Little is known about inherent reef morphology in the absence of external control. Here we use reef growth simulations, based on observations in the cellular reefs of Western Australia’s Houtman Abrolhos Islands, to show that reef morphology is fundamentally determined by the mechanical behaviour of the reef-building organisms themselves—specifically their tendency to either remain in place or to collapse. Reef-building organisms that tend to remain in place, such as massive and encrusting corals or coralline algae, produce nodular reefs, whereas those that tend to collapse, such as branching Acropora, produce cellular reefs. The purest reef growth forms arise in sheltered lagoons dominated by a single type of reef builder, as in the branching Acropora-dominated lagoons of the Abrolhos. In these situations reef morphology can be considered a phenotype of the predominant reef building organism. The capacity to infer coral type from reef morphology can potentially be used to identify and map specific coral habitat in remotely sensed images. More generally, identifying ecological mechanisms underlying other examples of self-generated reef morphology can potentially improve our understanding of present-day reef ecology, because any ecological process capable of shaping a reef will almost invariably be an important process in real time on the living reef. PMID:26175962

  5. Morphology of photoreceptor systems in microalgae.

    PubMed

    Gualtieri, P

    2001-06-01

    The polyphyletic artificial assemblage of O(2)-evolving, photosynthetic organisms, collectively referred to as algae, include a highly diverse array of organisms from large seaweeds (macroalgae) to unicellular microalgae. Phycology, the study of algae, focuses on morphological, ecological, physiological and molecular biological aspects of these organisms. Most microalgae show a photo-behaviour, i.e. they sense light and move towards it; in this review we will describe morphological similarities and differences in the photoreceptive system of microalgae.

  6. ISIS-2 satellite imagery and auroral morphology

    NASA Technical Reports Server (NTRS)

    Anger, C. D.; Murphree, J. S.

    1976-01-01

    Auroral morphology is emphasized over auroral dynamics in a paper describing conspicuous auroral features picked up by the ISIS-2 scanning photometer. Results of improved programs designed to transform the data into a corrected geomagnetic coordinate frame and generate latitude profiles of auroral intensities at different magnetic local times are reported. The diffuse aurora and its relation to the morphology of discrete aurorae is given special attention.

  7. Rubber-Modified Epoxies: Transitions and Morphology.

    DTIC Science & Technology

    1980-09-01

    Table 2. Composition and Cure of Model Resins: Notation. Table 3. Morphology: Summary. FIGURE CAPTIONS Fig. 1. TBA damping curves for unmodified and...temperature of cure and the gelation time. These DD 1473 om~ow* orimv as to .gews ~ 410 3 ? U611111Iry OLASSIPCATSWor TISite Answ IO - ------ AIR- SECURITV...rubber, the temperature of cure and the gelation time. These ideas have been exploited to control the development of morphology of these amorphous

  8. Morphological variation, advertisement call, and tadpoles of Bokermannohyla nanuzae (Bokermann, 1973), and taxonomic status of B. feioi (Napoli & Caramaschi, 2004) (Anura, Hylidae, Cophomantini).

    PubMed

    Walker, Marina; Lourenço, Ana Carolina Calijorne; Pimenta, Bruno V S; Nascimento, Luciana Barreto

    2015-03-24

    Bokermannohyla nanuzae (Bokermann & Sazima 1973) and B. feioi (Napoli & Caramaschi 2004) belong to the B. cir-cumdata species group. The type locality of the former is Serra do Cipó, Espinhaço mountain range, and of the latter is Parque Estadual do Ibitipoca, Mantiqueira mountain range, both in Minas Gerais State, Brazil. Differences on dorsal draw-ing pattern of adults, oral disc morphology of tadpoles, and temporal properties of calls were proposed to distinguish these two species. However, several specimens found between the two type localities remain unidentified because diagnostic characters and states occur in all of these populations. Thus, in order to assess these characters variations, we performed an analysis of the morphology and morphometry of adults, vocalization, and morphology of tadpoles. Specimens were divided into three operational taxonomic units (OTUs): B. nanuzae (Serra do Cipó and northwards, Espinhaço mountain range), B. cf. nanuzae (Quadrilátero Ferrífero, Espinhaço mountain range, south of Serra do Cipó), and B. feioi (Serra do Ibitipoca, Mantiqueira mountain range). Drawing patterns of the dorsum and limbs show clinal variation and the three units are morphometrically very similar. Temporal and spectral properties of calls overlap in these three units. The diagnostic differences originally proposed for tadpoles are intrapopulational variations and occur in specimens from all of the locations analyzed. We found that these three units are morphologically indistinguishable. Therefore, we designate Bok-ermannohyla feioi (Napoli & Caramaschi 2004) as a junior synonym of Bokermannohyla nanuzae (Bokermann & Sazima 1973), extending its geographical distribution to the Mantiqueira mountain range.

  9. Morphological theory in image feature extraction

    NASA Astrophysics Data System (ADS)

    Gui, Feng; Lin, QiWei

    2003-06-01

    As we know that morphology is the technique that based upon set theory and it can be used for binary image processing and gray image processing. The principle and the geometrical meaning of morphological boundary detecting for image were discussed in this paper, and the selecting of structure element was analyzed. Comparison was made between morphological boundary detecting and traditional boundary detecting method, conclusion that morphological boundary detecting method has better compatibility and anti-interference capability was reached. The method was also used for L.V. cineangiograms processing. In this paper we hoped to build up a foundation for automatic detection of L.V. contours based on the features of L.V. cineangiograms and Morphological theory, for the further study of L.V. wall motion abnormalities, because wall motion abnormalities of L.V. due to myocardia ischeamia caused by coronary atherosclerosis is a significant feature of Atherosclerotic coronary heart disease (CHD). An algorithm that based on morphology for L.V. contours extracting was developed in this paper.

  10. Sperm Morphology Assessment in Captive Neotropical Primates.

    PubMed

    Swanson, W F; Valle, R R; Carvalho, F M; Arakaki, P R; Rodas-Martínez, A Z; Muniz, Japc; García-Herreros, M

    2016-08-01

    The main objective of this study was to evaluate sperm morphology in four neotropical primate species to compare the sperm morphological traits and the sperm morphometric parameters as a basis for establishing normative sperm standards for each species. Data from 80 ejaculates collected from four primate species, Callithrix jacchus, Callimico goeldii, Alouatta caraya and Ateles geoffroyi, were analysed for detection of sperm morphological alterations using subjective World Health Organization (WHO-2010) standards and Sperm Deformity Index (SDI) criteria, objective computer-assisted sperm morphometry analysis (CASMA) and subpopulation sperm determination (SSD) methods. There were multiple differences (p < 0.01) observed among primate species in values obtained from WHO-2010, SDI, CASMA and SSD sperm analysis methods. In addition, multiple significant positive and negative correlations were observed between the sperm morphological traits (SDI, Sperm Deformity Index Head Defects, Sperm Deformity Index Midpiece Defects, Sperm Deformity Index Tail Defects, Normal Sperm, Head Defects, Midpiece Defects and Tail Defects) and the sperm morphometric parameters (SSD, Area (A), Perimeter (P), Length (L), Width (W), Ellipticity, Elongation and Rugosity) (p ≤ 0.046). In conclusion, our findings using different evaluation methods indicate that pronounced sperm morphological variation exists among these four neotropical primate species. Because of the strong relationship observed among morphological and morphometric parameters, these results suggest that application of objective analysis methods could substantially improve the reliability of comparative studies and help to establish valid normative sperm values for neotropical primates.

  11. Distinguishing Bicontinuous Lipid Cubic Phases from Isotropic Membrane Morphologies Using 31P Solid-State NMR Spectroscopy

    PubMed Central

    Yang, Yu; Yao, Hongwei

    2015-01-01

    Nonlamellar lipid membranes are frequently induced by proteins that fuse, bend, and cut membranes. Understanding the mechanism of action of these proteins requires the elucidation of the membrane morphologies that they induce. While hexagonal phases and lamellar phases are readily identified by their characteristic solid-state NMR lineshapes, bicontinuous lipid cubic phases are more difficult to discern, since the static NMR spectra of cubic-phase lipids consist of an isotropic 31P or 2H peak, indistinguishable from the spectra of isotropic membrane morphologies such as micelles and small vesicles. To date, small-angle X-ray scattering is the only method to identify bicontinuous lipid cubic phases. To explore unique NMR signatures of lipid cubic phases, we first describe the orientation distribution of lipid molecules in cubic phases and simulate the static 31P chemical shift lineshapes of oriented cubic-phase membranes in the limit of slow lateral diffusion. We then show that 31P T2 relaxation times differ significantly between isotropic micelles and cubic-phase membranes: the latter exhibit two-orders-of magnitude shorter T2 relaxation times. These differences are explained by the different timescales of lipid lateral diffusion on the cubic-phase surface versus the timescales of micelle tumbling. Using this relaxation NMR approach, we investigated a DOPE membrane containing the transmembrane domain (TMD) of a viral fusion protein. The static 31P spectrum of DOPE shows an isotropic peak, whose T2 relaxation times correspond to that of a cubic phase. Thus, the viral fusion protein TMD induces negative Gaussian curvature, which is an intrinsic characteristic of cubic phases, to the DOPE membrane. This curvature induction has important implications to the mechanism of virus-cell fusion. This study establishes a simple NMR diagnostic probe of lipid cubic phases, which is expected to be useful for studying many protein-induced membrane remodeling phenomena in biology

  12. SDSS superclusters: morphology and galaxy content

    NASA Astrophysics Data System (ADS)

    Einasto, M.; Lietzen, H.; Tempel, E.; Gramann, M.; Liivamägi, L. J.; Einasto, J.

    2014-02-01

    Context. Understanding the formation, evolution and present-day properties of the cosmic web and objects forming it is an important task in cosmology. Aims: We compare the galaxy populations in superclusters of different morphology in the nearby Universe (180 h-1 Mpc ≤ d ≤ 270 h-1 Mpc) to see whether the inner structure and overall morphology of superclusters are important in shaping galaxy properties in superclusters. Methods: We find supercluster morphology with Minkowski functionals and analyse the probability density distributions of colours, morphological types, stellar masses, star formation rate (SFR) of galaxies, and the peculiar velocities of the main galaxies in groups in superclusters of filament and spider types, and in the field. We test the statistical significance of the results with the KS test. Results: The fraction of red, early-type, low SFR galaxies in filament-type superclusters is higher than in spider-type superclusters; in low-density global environments their fraction is lower than in superclusters. In all environments the fraction of red, high stellar mass, and low SFR galaxies in rich groups is higher than in poor groups. In superclusters of spider morphology red, high SFR galaxies have higher stellar masses than in filament-type superclusters. Groups of equal richness host galaxies with larger stellar masses, a larger fraction of early-type and red galaxies, and a higher fraction of low SFR galaxies, if they are located in superclusters of filament morphology. The peculiar velocities of the main galaxies in groups from superclusters of filament morphology are higher than in those of spider morphology. Groups with higher peculiar velocities of their main galaxies in filament-type superclusters are located in higher density environment than those with low peculiar velocities. There are significant differences between galaxy populations of the individual richest superclusters. Conclusions: Both local (group) and global (supercluster

  13. Predicting vegetation-stabilized dune morphology

    NASA Astrophysics Data System (ADS)

    Barchyn, T.; Hugenholtz, C.

    2012-04-01

    The morphology of vegetation-stabilized dune fields on the North American Great Plains mostly comprises parabolic dunes; stabilized barchan and transverse dunes are rare. One notable exception is the Nebraska Sand Hills (NSH), where massive grass-covered barchan and transverse dunes bear proof of former desert-like conditions. We present a hypothesis from a numerical dune field model to explain the vegetation-stabilized morphology of dunes. The model incorporates a growth curve that preferentially grows vegetation in regions of sediment deposition with a sharp drop in growth at the peak depositional tolerance of vegetation, qualitatively matching biological response to erosion and deposition. Simulations on a range of pre-stabilization dune morphologies, from large closely-spaced transverse dunes to small dispersed barchans, indicate that the stabilized morphology is largely determined by the ratio of slipface deposition rate to peak depositional tolerance of vegetation. Conceptually, slipface deposition rate is related to dune height and celerity. By keeping depositional tolerance constant (representing a constant vegetation type and climate) the model shows that large slow-moving dunes have low slipface deposition rates and essentially 'freeze' in place once vegetation is introduced, retaining their pre-vegetation morphology. Small fast-moving dunes have higher slipface deposition rates and evolve into parabolic dunes. We hypothesize that, when barchan and transverse dunes are subjected to a stabilizing climate shift that increases vegetation growth rate, they retain their pre-stabilization morphology if deposition rates are below the depositional tolerance of stabilizing vegetation, otherwise they become parabolic dunes. This could explain why NSH dunes are stabilized in barchan and transverse morphologies while elsewhere on the Great Plains dune fields are dominated by smaller parabolic dunes.

  14. Morphology Changing at Incipient Crystallization Condition

    NASA Astrophysics Data System (ADS)

    Toshima, Takeshi; Hamai, Ryo; Fujita, Saya; Takemura, Yuka; Takamatsu, Saori; Tafu, Masamoto

    2015-04-01

    Brushite (Dicalcium phosphate dihydrate, (DCPD), CaHPO4·2H2O) is one of key components in calcium phosphate system due to wide attractive material not only as bioceramics but also environmental materials. Morphology of DCPD crystals is important factor when one uses its functionality with chemical reaction; because its surface crystal face, shape and size rule the chemical reactivity, responsiveness. Moreover, physical properties are also changed the morphology; such as cohesion, dispersiveness, permeability and so on. If one uses DCPD crystals as environmental renovation materials to catch the fluoride ions, their shape require 020 crystal surfaces; which usually restricts their shape as plate-like structure. After the chemical reaction, the shape of sludge is not good for handling due to their agglutinate property. Therefore searching an effective parameter and developing the method to control the morphology of DCPD crystals is required. In past, we reported that initial concentration and pH value of starting solution, prepared by dissolving calcium nitrate, Ca(NO3)2 and ammonium dihydrogen phosphate, NH4H2PO4, changes the morphology of DCPD crystals and phase diagram of morphology of DCPD crystal depend on those parameter. The DCPD crystallization shows unique behaviour; products obtained higher initial concentration form single crystal-like structure and under lower condition, they form agglomerate crystal-like structure. These results contradict usual crystallization. Here we report that the effect of mixing process of two solutions. The morphology of DCPD crystals is changed from plate structure to petal structure by the arrangement. Our result suggests that morphology of DCPD crystals strongly depends at incipient crystallization condition and growth form is controllable by setting initial crystallization condition.

  15. Galaxy morphology - An unsupervised machine learning approach

    NASA Astrophysics Data System (ADS)

    Schutter, A.; Shamir, L.

    2015-09-01

    Structural properties poses valuable information about the formation and evolution of galaxies, and are important for understanding the past, present, and future universe. Here we use unsupervised machine learning methodology to analyze a network of similarities between galaxy morphological types, and automatically deduce a morphological sequence of galaxies. Application of the method to the EFIGI catalog show that the morphological scheme produced by the algorithm is largely in agreement with the De Vaucouleurs system, demonstrating the ability of computer vision and machine learning methods to automatically profile galaxy morphological sequences. The unsupervised analysis method is based on comprehensive computer vision techniques that compute the visual similarities between the different morphological types. Rather than relying on human cognition, the proposed system deduces the similarities between sets of galaxy images in an automatic manner, and is therefore not limited by the number of galaxies being analyzed. The source code of the method is publicly available, and the protocol of the experiment is included in the paper so that the experiment can be replicated, and the method can be used to analyze user-defined datasets of galaxy images.

  16. Morphological boundary detecting method in cineangiogram image

    NASA Astrophysics Data System (ADS)

    Gui, Feng; Lin, QiWei

    2002-04-01

    Atherosclerotic coronary heart disease (CHD) is one of the commonest diseases that is heavily hazardous to people's health. Wall motion abnormalities of L.V. due to myocardia ischeamia caused by coronary atherosclerosis is a significant feature of CHD. This paper was designed to build up a foundation for automatic detection of L.V. contours according to the features of L.V. cineangiograms, for a further study of L.V. wall motion abnormalities. An algorithm that based on morphology for L.V. contours extracting was developed in this paper. As we know morphology is a kind of technique based upon set theory and it can be used for binary image and gray image processing. The principle and the geometrical meaning of morphological boundary detecting for image were discussed in this paper, and the selection of structuring element was analyzed. Comparison was made between morphological boundary detecting and traditional boundary detecting method, conclusion that morphological boundary detecting method has better compatibility and anti-interference capability was reached.

  17. Template learning in morphological neural nets

    NASA Astrophysics Data System (ADS)

    Davidson, Jennifer L.; Sun, K.

    1991-07-01

    This paper presents an application of morphology neural networks to a template learning problem. Morphology neural networks are a nonlinear version of the familiar artificial neural networks. Typically, an artificial neural net is used to solve pattern classification problems One useful characterization of many neural network algorithms is the ability to 'learn' to respond correctly to new data based only on a selection of known data responses. For example, in the multilayer perceptron model, the 'learning' is a procedure whereby parameters are fed back from output to input neurons and the weights changed to give a better response. The morphological neural net in this paper solves a different type of image processing problem. Specifically, given an input image and an output image which corresponds to a dilated version of the input, one would like to determine what template produced the output. The problem corresponds to teaching the network to solve for the weights in a morphological net, as the weights are the template's values. A reasonable method has been investigated for the boolean case; in this paper results are presented for gray scale images. Image algebra has been shown to provide a succinct expression of neural networks algorithms and also to allow a generalization of neural networks, and thus the authors describe the algorithm in image algebra. The remainder of the paper gives a brief discussion of image algebra, the relationship of image algebra and neural networks, a recap of the dilation morphology neural network boolean for boolean images, and the generalization to grayscale data.

  18. Modeling disordered morphologies in organic semiconductors.

    PubMed

    Neumann, Tobias; Danilov, Denis; Lennartz, Christian; Wenzel, Wolfgang

    2013-12-05

    Organic thin film devices are investigated for many diverse applications, including light emitting diodes, organic photovoltaic and organic field effect transistors. Modeling of their properties on the basis of their detailed molecular structure requires generation of representative morphologies, many of which are amorphous. Because time-scales for the formation of the molecular structure are slow, we have developed a linear-scaling single molecule deposition protocol which generates morphologies by simulation of vapor deposition of molecular films. We have applied this protocol to systems comprising argon, buckminsterfullerene, N,N-Di(naphthalene-1-yl)-N,N'-diphenyl-benzidine, mer-tris(8-hydroxy-quinoline)aluminum(III), and phenyl-C61-butyric acid methyl ester, with and without postdeposition relaxation of the individually deposited molecules. The proposed single molecule deposition protocol leads to formation of highly ordered morphologies in argon and buckminsterfullerene systems when postdeposition relaxation is used to locally anneal the configuration in the vicinity of the newly deposited molecule. The other systems formed disordered amorphous morphologies and the postdeposition local relaxation step has only a small effect on the characteristics of the disordered morphology in comparison to the materials forming crystals.

  19. Morphologic studies in the skeletal dysplasias.

    PubMed Central

    Sillence, D. O.; Horton, W. A.; Rimoin, D. L.

    1979-01-01

    Considerable progress has been made in the delineation of the genetic skeletal dysplasias, a heterogeneous group of disorders, that consist of over 80 distinct conditions. Morphologic studies have added a further dimension to the delineation of these conditions, their diagnosis, and the investigation of their pathogenetic mechanisms. In certain diseases, the morphologic alterations are characteristic and pathognomonic. In others only nonspecific alterations are observed, whereas in still other disorders growth-plate structure is essentially normal. Histologic, histochemical, and electronmicroscopic studies of growth-plate cartilage have provided new insights into the complexity of morphogenetic events in normal growth through the demonstration of morphologic defects in the genetic disorders of skeletal growth. As yet, very little is known of the biochemical abnormalities underlying the morphologic abnormalities. However, the great variety of morphologic findings points to a number of different pathogenetic defects in the synthesis, release, and assembly of connective tissue macromolecules and in the cells involved in growth-plate metabolism. Images Figure 4 Figure 8 Figure 5 Figure 7 Figure 10 Figure 6 Figure 9 Figure 1 Figure 3 Figure 2 PMID:474720

  20. Nanoscale Morphology Evolution Under Ion Irradiation

    SciTech Connect

    Aziz, Michael J.

    2014-11-10

    We showed that the half-century-old paradigm of morphological instability under irradiation due to the curvature-dependence of the sputter yield, can account neither for the phase diagram nor the amplification or decay rates that we measure in the simplest possible experimental system -- an elemental semiconductor with an amorphous surface under noble-gas ion irradiation; We showed that a model of pattern formation based on the impact-induced redistribution of atoms that do not get sputtered away explains our experimental observations; We developed a first-principles, parameter-free approach for predicting morphology evolution, starting with molecular dynamics simulations of single ion impacts, lasting picoseconds, and upscaling through a rigorous crater-function formalism to develop a partial differential equation that predicts morphology evolution on time scales more than twelve orders of magnitude longer than can be covered by the molecular dynamics; We performed the first quantitative comparison of the contributions to morphological instability from sputter removal and from impact-induced redistribution of atoms that are removed, and showed that the former is negligible compared to the latter; We established a new paradigm for impact-induced morphology evolution based on crater functions that incorporate both redistribution and sputter effects; and We developed a model of nanopore closure by irradiation-induced stress and irradiationenhanced fluidity, for the near-surface irradiation regime in which nuclear stopping predominates, and showed that it explains many aspects of pore closure kinetics that we measure experimentally.

  1. Morphological Awareness and Children's Writing: Accuracy, Error, and Invention.

    PubMed

    McCutchen, Deborah; Stull, Sara

    2015-02-01

    This study examined the relationship between children's morphological awareness and their ability to produce accurate morphological derivations in writing. Fifth-grade U.S. students (n = 175) completed two writing tasks that invited or required morphological manipulation of words. We examined both accuracy and error, specifically errors in spelling and errors of the sort we termed morphological inventions, which entailed inappropriate, novel pairings of stems and suffixes. Regressions were used to determine the relationship between morphological awareness, morphological accuracy, and spelling accuracy, as well as between morphological awareness and morphological inventions. Linear regressions revealed that morphological awareness uniquely predicted children's generation of accurate morphological derivations, regardless of whether or not accurate spelling was required. A logistic regression indicated that morphological awareness was also uniquely predictive of morphological invention, with higher morphological awareness increasing the probability of morphological invention. These findings suggest that morphological knowledge may not only assist children with spelling during writing, but may also assist with word production via generative experimentation with morphological rules during sentence generation. Implications are discussed for the development of children's morphological knowledge and relationships with writing.

  2. Influence of prepolymer composition on polyurethane morphology

    NASA Astrophysics Data System (ADS)

    Krishnamoorthy, Jayaraman; Jeong, Young Gyu; Hashida, Tomoko; Hsu, Shaw Ling

    2004-03-01

    Polyurethane chemistry is one of the most studied subjects. Yet many aspects remain unexplained. Polyurethanes are synthesized by the reaction of diisocyanate with diol in the presence of nucleophilic catalysts. Polyurethane prepolymers are obtained by reacting the polyester diol / polyether diol with diisocyanate, with [NCO] / [OH] > 1, resulting in isocyanate-terminated polyester/polyether mixture. Prepolymers thus synthesized can be cured at a later stage to realize various morphologies and structures. Though the initial composition and the final morphology are known, little is known about the intermediate prepolymer mixture. Due to the different reactivity of primary and secondary hydroxyl groups in the polyester and polyether towards isocyanate, prepolymer has a non-random distribution in terms of composition as blends and copolymers. Our aim is to characterize the prepolymer by different techniques and study how the different prepolymer composition, with varying polyester and polyether ratio, affects the morphology and phase separation kinetics of the final product.

  3. Cascade morphology transition in bcc metals

    DOE PAGES

    Setyawan, Wahyu; Selby, Aaron P.; Juslin, Niklas; ...

    2015-01-01

    Energetic atom collisions in solids induce shockwaves with complex morphologies. In this paper, we establish the existence of a morphological transition in such cascades. The order parameter of the morphology is defined as the exponent, b, in the defect production curve as a function of cascade energy (N-F similar to E-MD(b)). Response of different bcc metals can be compared in a consistent energy domain when the energy is normalized by the transition energy, mu, between the high-and the low-energy regime. Using Cr, Fe, Mo and W data, an empirical formula of mu as a function of displacement threshold energy, E-d,more » is presented for bcc metals.« less

  4. Cascade morphology transition in bcc metals

    SciTech Connect

    Setyawan, Wahyu; Selby, A.; Juslin, Niklas; Stoller, Roger E.; Wirth, Brian D.; Kurtz, Richard J.

    2015-06-10

    Energetic atom collisions in solids induce shockwaves with complex morphologies. In this paper, we establish the existence of a morphological transition in such cascades. The order parameter of the morphology is defined as the exponent, $b$, in the defect production curve as a function of cascade energy ($N_F$$ \\sim$$E_{MD}^b$). Response of different bcc metals can be compared in a consistent energy domain when the energy is normalized by the transition energy, $\\mu$, between the high- and the low-energy regime. Using Cr, Fe, Mo and W data, an empirical formula of $\\mu$ as a function of displacement threshold energy, $E_d$, is presented for bcc metals.

  5. Cascade morphology transition in bcc metals

    SciTech Connect

    Setyawan, Wahyu; Selby, Aaron P.; Juslin, Niklas; Stoller, Roger E.; Wirth, Brian D.; Kurtz, Richard J.

    2015-01-01

    Energetic atom collisions in solids induce shockwaves with complex morphologies. In this paper, we establish the existence of a morphological transition in such cascades. The order parameter of the morphology is defined as the exponent, b, in the defect production curve as a function of cascade energy (N-F similar to E-MD(b)). Response of different bcc metals can be compared in a consistent energy domain when the energy is normalized by the transition energy, mu, between the high-and the low-energy regime. Using Cr, Fe, Mo and W data, an empirical formula of mu as a function of displacement threshold energy, E-d, is presented for bcc metals.

  6. Mesoscale morphologies in polymer thin films.

    SciTech Connect

    Ramanathan, M.; Darling, S. B.

    2011-06-01

    In the midst of an exciting era of polymer nanoscience, where the development of materials and understanding of properties at the nanoscale remain a major R&D endeavor, there are several exciting phenomena that have been reported at the mesoscale (approximately an order of magnitude larger than the nanoscale). In this review article, we focus on mesoscale morphologies in polymer thin films from the viewpoint of origination of structure formation, structure development and the interaction forces that govern these morphologies. Mesoscale morphologies, including dendrites, holes, spherulites, fractals and honeycomb structures have been observed in thin films of homopolymer, copolymer, blends and composites. Following a largely phenomenological level of description, we review the kinetic and thermodynamic aspects of mesostructure formation outlining some of the key mechanisms at play. We also discuss various strategies to direct, limit, or inhibit the appearance of mesostructures in polymer thin films as well as an outlook toward potential areas of growth in this field of research.

  7. Juvenile morphology in baleen whale phylogeny

    NASA Astrophysics Data System (ADS)

    Tsai, Cheng-Hsiu; Fordyce, R. Ewan

    2014-09-01

    Phylogenetic reconstructions are sensitive to the influence of ontogeny on morphology. Here, we use foetal/neonatal specimens of known species of living baleen whales (Cetacea: Mysticeti) to show how juvenile morphology of extant species affects phylogenetic placement of the species. In one clade (sei whale, Balaenopteridae), the juvenile is distant from the usual phylogenetic position of adults, but in the other clade (pygmy right whale, Cetotheriidae), the juvenile is close to the adult. Different heterochronic processes at work in the studied species have different influences on juvenile morphology and on phylogenetic placement. This study helps to understand the relationship between evolutionary processes and phylogenetic patterns in baleen whale evolution and, more in general, between phylogeny and ontogeny; likewise, this study provides a proxy how to interpret the phylogeny when fossils that are immature individuals are included. Juvenile individuals in the peramorphic acceleration clades would produce misleading phylogenies, whereas juvenile individuals in the paedomorphic neoteny clades should still provide reliable phylogenetic signals.

  8. Mitochondrial morphology-emerging role in bioenergetics.

    PubMed

    Galloway, Chad A; Lee, Hakjoo; Yoon, Yisang

    2012-12-15

    Dynamic change in mitochondrial shape is a cellular process mediated mainly by fission and fusion of mitochondria. Studies have shown that mitochondrial fission and fusion are directly and indirectly associated with mitochondrial maintenance, bioenergetic demand, and cell death. Changes in mitochondrial morphology are frequently observed in response to changes in the surrounding cellular milieu, such as metabolic flux, that influence cellular bioenergetics. Connections between morphological regulation and the bioenergetic status of mitochondria are emerging as reciprocally responsive processes, though the nature of the signaling remains to be defined. Given the pivotal role mitochondria play in cellular fate, tight regulation of fission and fusion is therefore critical to preserving normal cellular physiology. Here we describe recent advancements in the understanding of the mechanisms governing mitochondrial morphology and their emerging role in mitochondrial bioenergetics.

  9. Juvenile morphology in baleen whale phylogeny.

    PubMed

    Tsai, Cheng-Hsiu; Fordyce, R Ewan

    2014-09-01

    Phylogenetic reconstructions are sensitive to the influence of ontogeny on morphology. Here, we use foetal/neonatal specimens of known species of living baleen whales (Cetacea: Mysticeti) to show how juvenile morphology of extant species affects phylogenetic placement of the species. In one clade (sei whale, Balaenopteridae), the juvenile is distant from the usual phylogenetic position of adults, but in the other clade (pygmy right whale, Cetotheriidae), the juvenile is close to the adult. Different heterochronic processes at work in the studied species have different influences on juvenile morphology and on phylogenetic placement. This study helps to understand the relationship between evolutionary processes and phylogenetic patterns in baleen whale evolution and, more in general, between phylogeny and ontogeny; likewise, this study provides a proxy how to interpret the phylogeny when fossils that are immature individuals are included. Juvenile individuals in the peramorphic acceleration clades would produce misleading phylogenies, whereas juvenile individuals in the paedomorphic neoteny clades should still provide reliable phylogenetic signals.

  10. Nematode taxonomy: from morphology to metabarcoding

    NASA Astrophysics Data System (ADS)

    Ahmed, M.; Sapp, M.; Prior, T.; Karssen, G.; Back, M.

    2015-11-01

    Nematodes represent a species rich and morphologically diverse group of metazoans inhabiting both aquatic and terrestrial environments. Their role as biological indicators and as key players in nutrient cycling has been well documented. Some groups of nematodes are also known to cause significant losses to crop production. In spite of this, knowledge of their diversity is still limited due to the difficulty in achieving species identification using morphological characters. Molecular methodology has provided very useful means of circumventing the numerous limitations associated with classical morphology based identification. We discuss herein the history and the progress made within the field of nematode systematics, the limitations of classical taxonomy and how the advent of high throughput sequencing is facilitating advanced ecological and molecular studies.

  11. Nanoscale Ionic Aggregate Morphology in Zwitterionic Copolymers

    NASA Astrophysics Data System (ADS)

    Choi, Jae-Hong; Huyck, Rebecca; Salas-de La Cruz, David; Long, Timothy E.; Winey, Karen I.

    2009-03-01

    The morphology of two different zwitterionic copolymers, poly(sulfobetaine methacrylate-ran-butyl acrylate), and poly(sulfobetaine methacrylamide-ran-butyl acrylate) are investigated as a function of the mol % content of SBMA (7 and 9 mol %) and SBMAm (6, 10 and 13 mol %), respectively. In both copolymers, X-ray scattering results show a new structure in the material arising from ionic aggregates. The sizes of the ionic aggregates are obtained through the scattering model. The sizes of the ionic aggregates increase as the ion content increases. The application of scanning transmission electron microscopy to the study of ionomer morphology has enabled direct, model-independent visualization of the ionic aggregates. The correlation between X-ray scattering results and the real space imaging for morphology of these zwitterionic copolymers will be presented.

  12. Modeling nearshore morphological evolution at seasonal scale

    USGS Publications Warehouse

    Walstra, D.-J.R.; Ruggiero, P.; Lesser, G.; Gelfenbaum, G.

    2006-01-01

    A process-based model is compared with field measurements to test and improve our ability to predict nearshore morphological change at seasonal time scales. The field experiment, along the dissipative beaches adjacent to Grays Harbor, Washington USA, successfully captured the transition between the high-energy erosive conditions of winter and the low-energy beach-building conditions typical of summer. The experiment documented shoreline progradation on the order of 20 m and as much as 175 m of onshore bar migration. Significant alongshore variability was observed in the morphological response of the sandbars over a 4 km reach of coast. A detailed sensitivity analysis suggests that the model results are more sensitive to adjusting the sediment transport associated with asymmetric oscillatory wave motions than to adjusting the transport due to mean currents. Initial results suggest that alongshore variations in the initial bathymetry are partially responsible for the observed alongshore variable morphological response during the experiment. Copyright ASCE 2006.

  13. Controlled morphological structure of magnesium oxide particles

    NASA Astrophysics Data System (ADS)

    Pradita, T.; Aji, B. B.; Shih, S. J.; Sudibyo

    2017-03-01

    Magnesium Oxide (MgO) based material have been widely used as catalyst, paints, flame retardants, semiconductors, additives in refractory and solid adsorbent. Morphology of a particle has significant influence towards their application. MgO particles were prepared from Magnesium Acetate (MgAc) and Magnesium Nitrate (MgN) precursors using ultrasonic spray pyrolysis method (SP). The MgO particles were characterized by thermogravimetry analysis (TGA), X-Ray Diffraction Analysis (XRD), Field Emission-Secondary Electron Microscopy (FE-SEM) and Transmission Electron Microscopy (TEM). This experimental study results each precursor could have more than one morphologies. It also suggests that the morphology of the MgO particles were controlled by the selection of the precursor, each precursor possess different particle formation characteristic, including the different crystallization rate and also related from the different decomposition behavior during the heating process of SP.

  14. The Relationship of Morphological Analysis and Morphological Decoding to Reading Comprehension

    ERIC Educational Resources Information Center

    Deacon, S. Hélène; Tong, Xiuli; Francis, Kathryn

    2017-01-01

    The ultimate goal of children's reading development is the full and fluid understanding of texts. Morphological structure awareness, or children's awareness of the minimal units of meaning in language, has been identified as a key skill influencing reading comprehension. Here, we evaluate the roles of morphological structure awareness and two…

  15. Morphology Tuning of Strontium Tungstate Nanoparticles

    SciTech Connect

    Joseph, S.; George, T.; George, K. C.; Sunny, A. T.; Mathew, S.

    2007-08-22

    Strontium tungstate nanocrystals in two different morphologies are successfully synthesized by controlled precipitation in aqueous and in poly vinyl alcohol (PVA) medium. Structural characterizations are carried out by XRD and SEM. The average particle size calculated for the SrWO4 prepared in the two different solvents ranges 20-24 nm. The SEM pictures show that the surface morphologies of the SrWO4 nanoparticles in aqueous medium resemble mushroom and the SrWO4 nanoparticles in PVA medium resemble cauliflower. Investigations on the room temperature luminescent properties of the strontium tungstate nanoparticles prepared in aqueous and PVA medium shows strong emissions around 425 nm.

  16. VIPERS: Galaxy morphology at z ˜ 1

    NASA Astrophysics Data System (ADS)

    Krywult, Janusz; Pollo, Agnieszka; Vipers Team

    2014-12-01

    We use spectroscopic VIPERS data to analyze morphological properties of galaxies at z ˜ 1. To determine galaxy morphologies, we estimate their Sérsic index. Then, we correlate it with galaxy rest-frame colors, and other physical properties. We find that the distribution of Sérsic index of our sample is bimodal, and well correlated with the color-bimodality of the galaxy distribution. So-called green valley (i.e. intermediate colour) galaxies often have intermediate values of Sérsic index which may support the hypothesis that at least a part of this population are galaxies in the transition phase.

  17. Bacterial Morphologies Supporting Cometary Panspermia: a Reappraisal

    NASA Astrophysics Data System (ADS)

    Wickramasinghe, Chandra

    It is nearly 30 years since the first decisive evidence of microbial morphologies in carbonaceous chondrites was discovered and reported by Hans Dieter Pflug. In addition to morphology other data, notably laser mass spectroscopy, served to confirm the identification of such structures as putative bacterial fossils. Recent examinations of cometary dust collected in the stratosphere and further studies of carbonaceous meteorites reaffirm the presence of putative microbial fossils. Since carbonaceous chondrites (particularly Type 1 chondrites) are thought to be extinct comets the data reviewed in this article provide strong support for theories of cometary panspermia.

  18. Cloning nanocrystal morphology with soft templates

    NASA Astrophysics Data System (ADS)

    Thapa, Dev Kumar; Pandey, Anshu

    2016-08-01

    In most template directed preparative methods, while the template decides the nanostructure morphology, the structure of the template itself is a non-general outcome of its peculiar chemistry. Here we demonstrate a template mediated synthesis that overcomes this deficiency. This synthesis involves overgrowth of silica template onto a sacrificial nanocrystal. Such templates are used to copy the morphologies of gold nanorods. After template overgrowth, gold is removed and silver is regrown in the template cavity to produce a single crystal silver nanorod. This technique allows for duplicating existing nanocrystals, while also providing a quantifiable breakdown of the structure - shape interdependence.

  19. Bacterial morphologies supporting cometary panspermia: a reappraisal

    NASA Astrophysics Data System (ADS)

    Wickramasinghe, Chandra

    2011-01-01

    It is nearly 30 years since the first decisive evidence of microbial morphologies in carbonaceous chondrites was discovered and reported by Hans Dieter Pflug. In addition to morphology, other data, notably laser mass spectroscopy, served to confirm the identification of such structures as putative bacterial fossils. Recent examinations of cometary dust collected in the stratosphere and further studies of carbonaceous meteorites reaffirm the presence of putative microbial fossils. Since carbonaceous chondrites (particularly Type 1 chondrites) are thought to be extinct comets the data reviewed in this article provide strong support for theories of cometary panspermia.

  20. Plastic solar cell interface and morphological characterization

    NASA Astrophysics Data System (ADS)

    Guralnick, Brett W.

    Plastic solar cell research has become an intense field of study considering these devices may be lightweight, flexible and reduce the cost of photovoltaic devices. The active layer of plastic solar cells are a combination of two organic components which blend to form an internal morphology. Due to the poor electrical transport properties of the organic components it is important to understand how the morphology forms in order to engineer these materials for increased efficiency. The focus of this thesis is a detailed study of the interfaces between the plastic solar cell layers and the morphology of the active layer. The system studied in detail is a blend of P3HT and PCBM that acts as the primary absorber, which is the electron donor, and the electron acceptor, respectively. The key morphological findings are, while thermal annealing increases the crystallinity parallel to the substrate, the morphology is largely unchanged following annealing. The deposition and mixing conditions of the bulk heterojunction from solution control the starting morphology. The spin coating speed, concentration, solvent type, and solution mixing time are all critical variables in the formation of the bulk heterojunction. In addition, including the terminals or inorganic layers in the analysis is critical because the inorganic surface properties influence the morphology. Charge transfer in the device occurs at the material interfaces, and a highly resistive transparent conducting oxide layer limits device performance. It was discovered that the electron blocking layer between the transparent conducting oxide and the bulk heterojunction is compromised following annealing. The electron acceptor material can diffuse into this layer, a location which does not benefit device performance. Additionally, the back contact deposition is important since the organic material can be damaged by the thermal evaporation of Aluminum, typically used for plastic solar cells. Depositing a thin thermal and

  1. Using Morphological Awareness Instruction to Improve Written Language Skills

    ERIC Educational Resources Information Center

    Apel, Kenn; Werfel, Krystal

    2014-01-01

    Purpose: Written English is a morphophonemic language. Researchers have documented that a conscious awareness of the morphological structure of English morphology is predictive of students' written language skills and that morphological awareness instruction leads to improvements in morphological awareness and in other written language…

  2. Exploring the Dimensionality of Morphological Knowledge for Adolescent Readers

    ERIC Educational Resources Information Center

    Goodwin, Amanda P.; Petscher, Yaacov; Carlisle, Joanne F.; Mitchell, Alison M.

    2017-01-01

    This study examined the dimensionality of morphological knowledge. The performance of 371 seventh- and eighth-graders on seven morphological knowledge tasks was investigated using confirmatory factor analysis. Results suggested that morphological knowledge was best fit by a bifactor model with a general factor of morphological knowledge and seven…

  3. Aspects of Bangime Phonology, Morphology, and Morphosyntax

    ERIC Educational Resources Information Center

    Hantgan, Abbie

    2013-01-01

    This dissertation provides a description of aspects of the phonology, morphology, and morphosyntax of Bangime. Bangime is a language isolate spoken in the Dogon language speaking area of Central Eastern Mali. Although the Bangande, the speakers of Bangime, self-identify with the Dogon, their language bears practically no resemblance to the…

  4. Topics in Mocho' Phonology and Morphology

    ERIC Educational Resources Information Center

    Palosaari, Naomi Elizabeth

    2011-01-01

    This dissertation is a grammatical description of several features of the morphology and phonology of the Mocho' language. Mocho' (Motozintleco) is a moribund Mayan language spoken in the Chiapas region of Mexico near the border of Guatemala. This dissertation, based on data collected during several field trips and supplemented with unpublished…

  5. Computation of Semantic Number from Morphological Information

    ERIC Educational Resources Information Center

    Berent, Iris; Pinker, Steven; Tzelgov, Joseph; Bibi, Uri; Goldfarb, Liat

    2005-01-01

    The distinction between singular and plural enters into linguistic phenomena such as morphology, lexical semantics, and agreement and also must interface with perceptual and conceptual systems that assess numerosity in the world. Three experiments examine the computation of semantic number for singulars and plurals from the morphological…

  6. Morphological Knowledge in Children with Dyslexia

    ERIC Educational Resources Information Center

    Duranovic, Mirela; Tinjak, Sanela; Turbic-Hadzagic, Amira

    2014-01-01

    The phonological skills are not the only linguistic abilities which are observed to have some influence on reading achievement in dyslexics. In addition to phonological skills, morphological skills should be also taken in consideration. The aim of this study is to extend investigation the linguistic abilities of children with dyslexia to the…

  7. Morphology of nematic and smectic vesicles

    PubMed Central

    Xing, Xiangjun; Shin, Homin; Bowick, Mark J.; Yao, Zhenwei; Jia, Lin; Li, Min-Hui

    2012-01-01

    Recent experiments on vesicles formed from block copolymers with liquid-crystalline side chains reveal a rich variety of vesicle morphologies. The additional internal order (“structure”) developed by these self-assembled block copolymer vesicles can lead to significantly deformed vesicles as a result of the delicate interplay between two-dimensional ordering and vesicle shape. The inevitable topological defects in structured vesicles of spherical topology also play an essential role in controlling the final vesicle morphology. Here we develop a minimal theoretical model for the morphology of the membrane structure with internal nematic/smectic order. Using both analytic and numerical approaches, we show that the possible low free energy morphologies include nano-size cylindrical micelles (nano-fibers), faceted tetrahedral vesicles, and ellipsoidal vesicles, as well as cylindrical vesicles. The tetrahedral vesicle is a particularly fascinating example of a faceted liquid-crystalline membrane. Faceted liquid vesicles may lead to the design of supramolecular structures with tetrahedral symmetry and new classes of nano-carriers. PMID:22431595

  8. Morphological Priming Survives a Language Switch

    ERIC Educational Resources Information Center

    Verdonschot, Rinus G.; Middelburg, Renee; Lensink, Saskia E.; Schiller, Niels O.

    2012-01-01

    In a long-lag morphological priming experiment, Dutch (L1)-English (L2) bilinguals were asked to name pictures and read aloud words. A design using non-switch blocks, consisting solely of Dutch stimuli, and switch-blocks, consisting of Dutch primes and targets with intervening English trials, was administered. Target picture naming was facilitated…

  9. Descriptive Morphology Terms For MAMA software

    SciTech Connect

    Ruggiero, Christy E.; Porter, Reid B.

    2014-05-21

    The table on the following pages lists a set of morphology terms for describing materials. We have organized these terms by categories. Software uses are welcome to suggest other terms that are needed to accurately describe materials. This list is intended as a initial starting point to generating a consensus terminology list.

  10. Sedimentation counting and morphology of Mycoplasma.

    PubMed

    Clark, H W

    1965-11-01

    Clark, Harold W. (The George Washington University School of Medicine, Washington, D.C.). Sedimentation counting and morphology of Mycoplasma. J. Bacteriol. 90:1373-1386. 1965.-The sedimentation technique for counting viral particles was applied to the quantitation and morphological identification of Mycoplasma in broth cultures. Mycoplasma, apparently in their native form, firmly adhered to the surface, when sedimented on glass cover slips or onto electron microscope grids. The sedimented cover slip preparations stained with crystal violet could be readily counted in the light microscope. The cultures sedimented onto electron microscope grids were readily counted at low magnification and provided excellent preparations for morphological examination at higher magnifications. It was found that air-dried Mycoplasma particles were enlarged considerably because of excessive flattening. Fixation of sedimented Mycoplasma particles in diluted OsO(4) prior to air drying yielded a more realistic morphology, with various sizes and shapes in the stages of the growth cycle exhibited. A new technique of differentially staining Mycoplasma colonies on agar plates was developed to facilitate the quantitation of viable colony-forming units for comparison with total counts. The use of plastic or Parafilm gaskets for dry mounting was developed to facilitate the handling and examination of the stained cover slip preparations. The results of this investigation indicated that the growth cycle of some Mycoplasma species includes a stage of hexadic fission with the cleavage of minimal reproductive units (less than 100 mmu) containing a limited deoxyribonucleic acid genetic coding molecule (approximately 4 x 10(6)).

  11. The morphology of Sersic-Pastoriza galaxies

    NASA Technical Reports Server (NTRS)

    Yates, G. J.; Pedlar, A.; Saikia, D. J.; Unger, S. W.; Axon, D. J.

    1990-01-01

    The authors present the preliminary results of their radio-continuum and neutral hydrogen observations of Sersic-Pastoriza (S-P) galaxies. They show that the central regions contain a population of compact features thought to be young supernova remnants (SNRs) and discuss the overall morphology of the nuclei.

  12. Generalisation of Regular and Irregular Morphological Patterns.

    ERIC Educational Resources Information Center

    Prasada, Sandeep; and Pinker, Steven

    1993-01-01

    When it comes to explaining English verbs' patterns of regular and irregular generalization, single-network theories have difficulty with the former, rule-only theories with the latter process. Linguistic and psycholinguistic evidence, based on observation during experiments and simulations in morphological pattern generation, independently call…

  13. Morphological rates of angiosperm seed size evolution.

    PubMed

    Sims, Hallie J

    2013-05-01

    The evolution of seed size among angiosperms reflects their ecological diversification in a complex fitness landscape of life-history strategies. The lineages that have evolved seeds beyond the upper and lower boundaries that defined nonflowering seed plants since the Paleozoic are more dispersed across the angiosperm phylogeny than would be expected under a neutral model of phenotypic evolution. Morphological rates of seed size evolution estimated for 40 clades based on 17,375 species ranged from 0.001 (Garryales) to 0.207 (Malvales). Comparative phylogenetic analysis indicated that morphological rates are not associated with the clade's seed size but are negatively correlated with the clade's position in the overall distribution of angiosperm seed sizes; clades with seed sizes closer to the angiosperm mean had significantly higher morphological rates than clades with extremely small or extremely large seeds. Likewise, per-clade taxonomic diversification rates are not associated with the seed size of the clade but with where the clade falls within the angiosperm seed size distribution. These results suggest that evolutionary rates (morphological and taxonomic) are elevated in densely occupied regions of the seed morphospace relative to lineages whose ecophenotypic innovations have moved them toward the edges.

  14. Functional innovations and morphological diversification in parrotfish.

    PubMed

    Price, Samantha A; Wainwright, Peter C; Bellwood, David R; Kazancioglu, Erem; Collar, David C; Near, Thomas J

    2010-10-01

    The association between diversification and evolutionary innovations has been well documented and tested in studies of taxonomic richness but the impact that such innovations have on the diversity of form and function is less well understood. Using phylogenetically rigorous techniques, we investigated the association between morphological diversity and two design breakthroughs within the jaws of parrotfish. Similar intramandibular joints and other modifications of the pharyngeal jaws have evolved repeatedly in teleost fish and are frequently hypothesized to promote diversity. We quantified morphological diversity within six functionally important oral jaw traits using the Brownian motion rate of evolution to correct for phylogenetic and time-related biases and compared these rates across clades that did and did not possess the intramandibular joint and the parrotfish pharyngeal jaw. No change in morphological diversity was associated with the pharyngeal jaw modification alone but rates of oral jaw diversification were up to 8× faster in parrotfish species that possessed both innovations. Interestingly, this morphological diversity may not have led to differential resource uses as available data suggest that members of this clade show remarkable homogeneity of diet.

  15. Morphological diversity of sperm: A mini review

    PubMed Central

    Prakash, Seppan; Prithiviraj, Elumalai; Suresh, Sekar; Lakshmi, Nagella Venkata; Ganesh, Mohanraj Karthik; Anuradha, Murugesan; Ganesh, Lakshmanan; Dinesh, Premavathy

    2014-01-01

    Sperms are highly specialized cells for delivering DNA from male to the ovum. Incredibly, wide degree of diversity in sperm morphology in their basic structures i.e. head, middle piece and tail is found across species. Differences in terms of overall size of the sperm, shape and number of sperm produced are also incredible. One of the key for this variations or diversity in sperm may be associated with female reproductive tract, sperm competition, testicular size and sperm size and number. Establishing a correlation between sperm morphology and factors influencing them is a phenomenal task. In this mini-review these associations and the anatomical and functional adaptations among different from of sperm cells that have evolved to optimize fertilization success are discussed. Nevertheless, explaining these morphological diversities in sperm cells is a challenging question and it seems that evolutionary biologists have only recently engaged in exploring its links and patterns. From the literatures it seems that there is no causal relationship between sperm size and testicular size, however, the accumulated knowledge do indicates evolution of sperm morphology across species has some associations with female reproductive tract, sperm competition and sperm size and number, however interpreting these results for phylogentic correlations should be approached with caution. PMID:24976817

  16. Morphological and Phonological Structure in Zulu Reduplication

    ERIC Educational Resources Information Center

    Cook, Toni

    2013-01-01

    This dissertation provides an account of Zulu reduplication within the derivational framework of Distributed Morphology (DM). New Zulu data challenge the idea of reified domains like the D(erivational)-Stem and Macrostem as relevant constituents for reduplication (Downing 1997, Hyman, Inkelas, and Sibanda 2009). Instead, a crucial distinction is…

  17. Grammatical Processing in Schizophrenia: Evidence from Morphology

    ERIC Educational Resources Information Center

    Walenski, Matthew; Weickert, Thomas W.; Maloof, Christopher J.; Ullman, Michael T.

    2010-01-01

    Patients with psychiatric disorders such as schizophrenia commonly present with impaired language. Here we investigate language in schizophrenia with a focus on inflectional morphology, using an intensively studied and relatively well-understood linguistic paradigm. Patients with schizophrenia (n = 43) and age-matched healthy control subjects (n =…

  18. Integrated molecular and morphological studies of Daucus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Ninety-four nuclear orthologs were used to analyze phylogenetic structure in 92 accessions of 13 species and two subspecies of Daucus, and 15 accessions of related genera. A near parallel set of accessions was used for morphological analyses of germplasm. Reiterative analyses examined data of both a...

  19. Integrated molecular and morphological studies of Daucus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Ninety-four nuclear orthologs were used to analyze phylogenetic structure in 89 accessions of 13 species and two subspecies of Daucus, and an additional ten accessions of related genera. A near parallel set of accessions were used for morphological analyses of germplasm planted in a common garden in...

  20. Factors affecting spermatozoa morphology in beef bulls

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The objective of this study was to evaluate factors affecting sperm morphology of bulls (n=908) collected at 320 days of age. Bulls were a composite breed (50% Red Angus, 25% Charolais, and 25% Tarentaise) born from 2002 to 2008 to dams fed levels of feed during mid and late gestation that were expe...

  1. 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.

  2. Comparative evolution of flower and fruit morphology

    PubMed Central

    Whitney, Kenneth D.

    2009-01-01

    Angiosperm diversification has resulted in a vast array of plant morphologies. Only recently has it been appreciated that diversification might have proceeded quite differently for the two key diagnostic structures of this clade, flowers and fruits. These structures are hypothesized to have experienced different selective pressures via their interactions with animals in dispersal mutualisms, resulting in a greater amount of morphological diversification in animal-pollinated flowers than in animal-dispersed fruits. I tested this idea using size and colour traits for the flowers and fruits of 472 species occurring in three floras (St John, Hawaii and the Great Plains). Phylogenetically controlled analyses of nearest-neighbour distances in multidimensional trait space matched the predicted pattern: in each of the three floras, flowers were more divergent from one another than were fruits. In addition, the spacing of species clusters differed for flowers versus fruits in the flora of St John, with clusters in flower space more divergent than those in fruit space. The results are consistent with the idea that a major driver of angiosperm diversification has been stronger selection for divergent floral morphology than for divergent fruit morphology, although genetic, physiological and ecological constraints may also play a role. PMID:19474045

  3. Morphology: The Descriptive Analysis of Words.

    ERIC Educational Resources Information Center

    Nida, Eugene A.

    This textbook establishes principles and methodology for researching and analyzing the morphological systems of languages. The sequence of approach used in the text begins with procedures for the identification of morphemes and deals with types, distribution, structural classes, and meanings of morphemes. The final chapters present field…

  4. Sexing California Clapper Rails using morphological measurements

    USGS Publications Warehouse

    Overton, Cory T.; Casazza, Michael L.; Takekawa, John Y.; Rohmer, Tobias M.

    2009-01-01

    California Clapper Rails (Rallus longirostris obsoletus) have monomorphic plumage, a trait that makes identification of sex difficult without extensive behavioral observation or genetic testing. Using 31 Clapper Rails (22 females, 9 males), caught in south San Francisco Bay, CA, and using easily measurable morphological characteristics, we developed a discriminant function to distinguish sex. We then validated this function on 33 additional rails. Seven morphological measurements were considered, resulting in three which were selected in the discriminate function: culmen length, tarsometatarsus length, and flat wing length. We had no classification errors for the development or testing datasets either with resubstitution or cross-validation procedures. Male California Clapper Rails were 6-22% larger than females for individual morphological traits, and the largest difference was in body mass.  Variables in our discriminant function closely match variables developed for sexing Clapper Rails of Gulf Coast populations. However, a universal discriminant function to sex all Clapper Rail subspecies is not likely because of large and inconsistent differences in morphological traits among subspecies. 

  5. Sublexical and Morphological Information in Speech Processing

    ERIC Educational Resources Information Center

    Zwitserlood, Pienie

    2004-01-01

    Three experiments investigated the impact of syllabic boundary information and of morphological structure on performance in a sequence-monitoring task. In sequence monitoring, participants detect pre-specified sequences of phonemes in spoken carrier words. Sequences corresponded to the first syllable of the carrier word, to its first morpheme, or…

  6. Airway adequacy, head posture, and craniofacial morphology.

    PubMed

    Solow, B; Siersbaek-Nielsen, S; Greve, E

    1984-09-01

    Previous studies of different samples have demonstrated associations between craniocervical angulation and craniofacial morphology, between airway obstruction by adenoids and craniofacial morphology, and between airway obstruction and craniocervical angulation. A hypothesis to account for the different sets of associations was suggested by Solow and Kreiborg in 1977. In the present study, the three sets of associations were examined in a single group of nonpathologic subjects with no history of airway obstruction. Cephalometric radiographs taken in the natural head position and rhinomanometric recordings were obtained from twenty-four children 7 to 9 years of age. Correlations were calculated between twenty-seven morphologic, eight postural, and two airway variables. A large craniocervical angle was, on the average, seen in connection with small mandibular dimensions, mandibular retrognathism, and a large mandibular inclination. Obstructed nasopharyngeal airways (defined as a small pm-ad 2 radiographic distance and a large nasal respiratory resistance, NRR, determined rhinomanometrically) were, on the average, seen in connection with a large craniocervical angle and with small mandibular dimensions, mandibular retrognathism, a large mandibular inclination, and retroclination of the upper incisors. The observed correlations were in agreement with the predicted pattern of associations between craniofacial morphology, craniocervical angulation, and airway resistance, thus suggesting the simultaneous presence of such associations in the sample of nonpathologic subjects with no history of airway obstruction.

  7. The morphology of Sersic-Pastoriza galaxies

    NASA Astrophysics Data System (ADS)

    Yates, G. J.; Pedlar, A.; Saikia, D. J.; Unger, S. W.; Axon, D. J.

    1990-11-01

    The authors present the preliminary results of their radio-continuum and neutral hydrogen observations of Sersic-Pastoriza (S-P) galaxies. They show that the central regions contain a population of compact features thought to be young supernova remnants (SNRs) and discuss the overall morphology of the nuclei.

  8. Cotton and its interaction with cotton morphology

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The morphological plasticity of the cotton plant enables it to be produced in a wide variety of agro-ecological regions (Oosterhuis and Jernstedt 1999). This plasticity essentially translates to the lengthening, shortening, or interruption of its effective flowering period in response to season leng...

  9. An experimental investigation of olivine morphology

    NASA Technical Reports Server (NTRS)

    Donaldson, C. H.

    1976-01-01

    Results are reported for a morphological study of olivine and an experimental investigation performed to determine the degrees of supercooling and the cooling rates necessary to crystallize particular morphologies. Ten arbitrary categories of three-dimensional olivine crystal shape are identified: polyhedral, granular, hopper, chain, lattice, plate, branching, radiate, feather, and swallow-tail. The morphological study establishes that equant and tabular crystals are the common shapes of olivine, nonequant crystals are elongate parallel to the a or c axis, and skeletal crystals result when a particular form is missing or only partially developed. In the experiment, olivine crystals were grown by melting rock samples above their liquidus temperatures before initiating crystallization. The results show that olivine morphology changes systematically as a function of the degree of melt supercooling, the melt cooling rate, and the normative olivine and water contents of the melt. It is also found that each shape has a specific range of temperature stability which is essentially independent of melt composition.

  10. Morphological Sensitivity in Deaf Readers of Dutch

    ERIC Educational Resources Information Center

    Van Hoogmoed, Anne H.; Verhoeven, Ludo; Schreuder, Robert; Knoors, Harry

    2011-01-01

    Deaf children experience difficulties with reading comprehension. These difficulties are not completely explained by their difficulties with the reading of single short words. Whether deaf children and adults lag behind in the morphological processing of longer words is therefore examined in two experiments in which the processing of prefixes by…

  11. Relating rock avalanche morphology to emplacement processes

    NASA Astrophysics Data System (ADS)

    Dufresne, Anja; Prager, Christoph; Bösmeier, Annette

    2015-04-01

    The morphology, structure and sedimentological characteristics of rock avalanche deposits reflect both internal emplacement processes and external influences, such as runout path characteristics. The latter is mainly predisposed by topography, substrate types, and hydrogeological conditions. Additionally, the geological setting at the source slope controls, e.g. the spatial distribution of accumulated lithologies and hence material property-related changes in morphology, or the maximum clast size and amount of fines of different lithological units. The Holocene Tschirgant rock avalanche (Tyrol, Austria) resulted from failure of an intensely deformed carbonate rock mass on the southeast face of a 2,370-m-high mountain ridge. The initially sliding rock mass rapidly fragmented as it moved towards the floor of the Inn River valley. Part of the 200-250 x 106 m3 (Patzelt 2012) rock avalanche debris collided with and moved around an opposing bedrock ridge and flowed into the Ötz valley, reaching up to 6.3 km from source. Where the Tschirgant rock avalanche spread freely it formed longitudinal ridges aligned along motion direction as well as smaller hummocks. Encountering high topography, it left runup ridges, fallback patterns (i.e. secondary collapse), and compressional morphology (successively elevated, transverse ridges). Further evidence for the mechanical landslide behaviour is given by large volumes of mobilized valley-fill sediments (polymict gravels and sands). These sediments indicate both shearing and compressional faulting within the rock avalanche mass (forming their own morphological units through, e.g. in situ bulldozing or as distinctly different hummocky terrain), but also indicate extension of the spreading landslide mass (i.e. intercalated/injected gravels encountered mainly in morphological depressions between hummocks). Further influences on its morphology are given by the different lithological units. E.g. the transition from massive dolomite

  12. Comparison of morphological and genetic analyses reveals cryptic divergence and morphological plasticity in Stylophora (Cnidaria, Scleractinia)

    NASA Astrophysics Data System (ADS)

    Stefani, Fabrizio; Benzoni, F.; Yang, S.-Y.; Pichon, M.; Galli, P.; Chen, C. A.

    2011-12-01

    A combined morphological and genetic study of the coral genus Stylophora investigated species boundaries in the Gulf of Aden, Yemen. Two mitochondrial regions, including the hypervariable IGS9 spacer and the control region, and a fragment of rDNA were used for phylogenetic analysis. Results were compared by multivariate analysis on the basis of branch morphology and corallite morphometry. Two species were clearly discriminated by both approaches. The first species was characterised by small corallites and a low morphological variability and was ascribed to a new geographical record of Stylophora madagascarensis on the basis of its phylogenetic distinction and its morphological similarity to the type material. The second species was characterised by larger corallite size and greater morphological variability and was ascribed to Stylophora pistillata. The analysis was extended to the intrageneric level for other S. pistillata populations from the Red Sea and the Pacific Ocean. Strong internal divergence was evident in the genus Sty lophora. S. pistillata populations were split into two highly divergent Red Sea/Gulf of Aden and western Pacific lineages with significant morphological overlap, which suggests they represent two distinct cryptic species. The combined use of morphological and molecular approaches, so far proved to be a powerful tool for the re-delineation of species boundaries in corals, provided novel evidence of cryptic divergence in this group of marine metazoans.

  13. Standardizing the nomenclature of Martian impact crater ejecta morphologies

    USGS Publications Warehouse

    Barlow, Nadine G.; Boyce, Joseph M.; Costard, Francois M.; Craddock, Robert A.; Garvin, James B.; Sakimoto, Susan E.H.; Kuzmin, Ruslan O.; Roddy, David J.; Soderblom, Laurence A.

    2000-01-01

    The Mars Crater Morphology Consortium recommends the use of a standardized nomenclature system when discussing Martian impact crater ejecta morphologies. The system utilizes nongenetic descriptors to identify the various ejecta morphologies seen on Mars. This system is designed to facilitate communication and collaboration between researchers. Crater morphology databases will be archived through the U.S. Geological Survey in Flagstaff, where a comprehensive catalog of Martian crater morphologic information will be maintained.

  14. Morphological Peculiarities of Distant and Local Galaxies

    NASA Astrophysics Data System (ADS)

    Wu, K. L.; Faber, S. M.; Lauer, T. R.

    1997-12-01

    Detailed images from the Hubble Space Telescope (HST) have sparked a surge of interest in morphological peculiarities in both distant and local galaxies. Several groups have developed criteria by which to classify peculiarities in galaxy morphology (e.g., Abraham et al. 1996, Naim et al. 1997). In order to study peculiar galaxies at high redshifts, it is crucial to have a solid understanding of both the morphological peculiarities in local galaxies and the appearance of local galaxies if they were observed at higher redshifts. We are developing several algorithms to quantify the types and degree of peculiarity seen in galaxy morphology. These algorithms, or peculiarity indices, are sensitive to several different types of features. The indices are applied initially to two samples: (1) a local galaxy sample, comprised of a subset of the Frei, et al. 1996 ``Catalog of Nearby Galaxies,'' along with several merger candidates from Hibbard & van Gorkom 1996 and from a run on the Lick Observatory Nickel 40-inch telescope by one of the authors (KLW); and (2) a sample of simulated z ~ 0.8 galaxies. The images of the local galaxies are resampled, and noise is added, to reflect the sampling and noise levels found in the Hubble Deep Field (HDF). The galaxy sizes and surface brightnesses are cosmologically shifted to simulate observations of these galaxies through the HST F814W ( ~ I) filter at z ~ 0.8. This study expands upon previous work by providing a realistic view of which local morphological features we can expect to measure robustly when observed at high redshifts with the current observational technology. We also demonstrate the effectiveness of our peculiarity indices in differentiating between ``normal'' (i.e., Hubble Sequence type) galaxies and ``peculiar'' galaxies at these two epochs.

  15. Modeling nearshore morphological evolution at seasonal scale

    NASA Astrophysics Data System (ADS)

    Ruggiero, P.; Walstra, D.; Lesser, G.; Hanes, D.; Gelfenbaum, G.

    2004-12-01

    For the first time, process and nearshore bottom change measurements are being coupled along the dissipative, yet dynamic, beaches of the U.S. Pacific Northwest. A Spring 2001 field experiment on the ebb-tidal delta and adjacent beaches near Grays Harbor, Washington USA provides detailed information about bed sediments, waves, currents, suspended-sediment concentrations, and sea-bed change for the testing and improvement of numerical models of sediment transport and morphology change. Upwelling favorable winds from the NW predominated during the two-month deployment period which successfully captured the transition between the high-energy erosive conditions of winter and the low-energy beach-building conditions typical of summer. During the experiment onshore sandbar migration O(75m), trough infilling O(1m), and sub-aerial beach (shoreline) progradation O(10m) dominated nearshore morphological changes. However, over the four kilometer study area, significant alongshore variability in morphological response was observed. To investigate the mechanisms responsible for these observed morphological changes we are using a combination of data analysis techniques and numerical model simulations. Our specific research questions include: 1) What are the relative contributions of alongshore versus cross-shore processes in seasonal morphological change? and 2) What are the mechanisms responsible for the significant alongshore variability observed in both the sandbar and the shoreline response over only a few kilometers? A recently developed capacity to model cross-shore profile change (1DV) within an overall area modeling framework (2DH or 3D) is being applied to answer these questions. Model parameters are tuned by initially balancing onshore transports due to asymmetric oscillatory wave motion and offshore transport due to undertow along a series of individual cross-shore profiles. Area model results then allow us to explore the role of cell circulation and alongshore

  16. Sonic morphology: Aesthetic dimensional auditory spatial awareness

    NASA Astrophysics Data System (ADS)

    Whitehouse, Martha M.

    The sound and ceramic sculpture installation, " Skirting the Edge: Experiences in Sound & Form," is an integration of art and science demonstrating the concept of sonic morphology. "Sonic morphology" is herein defined as aesthetic three-dimensional auditory spatial awareness. The exhibition explicates my empirical phenomenal observations that sound has a three-dimensional form. Composed of ceramic sculptures that allude to different social and physical situations, coupled with sound compositions that enhance and create a three-dimensional auditory and visual aesthetic experience (see accompanying DVD), the exhibition supports the research question, "What is the relationship between sound and form?" Precisely how people aurally experience three-dimensional space involves an integration of spatial properties, auditory perception, individual history, and cultural mores. People also utilize environmental sound events as a guide in social situations and in remembering their personal history, as well as a guide in moving through space. Aesthetically, sound affects the fascination, meaning, and attention one has within a particular space. Sonic morphology brings art forms such as a movie, video, sound composition, and musical performance into the cognitive scope by generating meaning from the link between the visual and auditory senses. This research examined sonic morphology as an extension of musique concrete, sound as object, originating in Pierre Schaeffer's work in the 1940s. Pointing, as John Cage did, to the corporeal three-dimensional experience of "all sound," I composed works that took their total form only through the perceiver-participant's participation in the exhibition. While contemporary artist Alvin Lucier creates artworks that draw attention to making sound visible, "Skirting the Edge" engages the perceiver-participant visually and aurally, leading to recognition of sonic morphology.

  17. Quantification of Osteon Morphology Using Geometric Histomorphometrics.

    PubMed

    Dillon, Scott; Cunningham, Craig; Felts, Paul

    2016-03-01

    Many histological methods in forensic anthropology utilize combinations of traditional histomorphometric parameters which may not accurately describe the morphology of microstructural features. Here, we report the novel application of a geometric morphometric method suitable when considering structures without anatomically homologous landmarks for the quantification of complete secondary osteon size and morphology. The method is tested for its suitability in the measurement of intact secondary osteons using osteons digitized from transverse femoral diaphyseal sections prepared from two human individuals. The results of methodological testing demonstrate the efficacy of the technique when applied to intact secondary osteons. In providing accurate characterization of micromorphology within the robust mathematical framework of geometric morphometrics, this method may surpass traditional histomorphometric variables currently employed in forensic research and practice. A preliminary study of the intersectional histomorphometric variation within the femoral diaphysis is made using this geometric histomorphometric method to demonstrate its potential.

  18. [Heart morphologic state in retired fighter pilots].

    PubMed

    Yang, X E; Chen, Z G; Long, L; Zhai, D S; Zhao, X J; Fang, R Y

    2000-12-01

    Objective. To study the heart morphology in the retired fighter pilots, and to provide clinical evidence for protection combined G-loads (+ Gz), heat, noise, hypoxic and vibration stress induced cardiac structural damage. Method. Parameters of heart morphology were studied using Doppler echocardiography in 40 retired fighter pilots with 40 veteran cadres as control. Result. LVDd, LVDs, LADs, LVEDV, LVPWs and LVM in pilot group were somewhat higher than those in control group (NS); while IVSs and LVMI in pilot group were slightly lower than those in control group (NS); LVESV, aortic valve area, internal diameter of the ring and sinus in pilot group were significantly higher than those in control group (P < 0.05). Conclusion. Analysis of the results revealed no pathomorphologic damage of the heart. It suggest that all the variations can be regarded as adaptive changes due to the effects of the combined environmental factors experienced in long time flying.

  19. Modelling the morphology of migrating bacterial colonies

    NASA Astrophysics Data System (ADS)

    Nishiyama, A.; Tokihiro, T.; Badoual, M.; Grammaticos, B.

    2010-08-01

    We present a model which aims at describing the morphology of colonies of Proteus mirabilis and Bacillus subtilis. Our model is based on a cellular automaton which is obtained by the adequate discretisation of a diffusion-like equation, describing the migration of the bacteria, to which we have added rules simulating the consolidation process. Our basic assumption, following the findings of the group of Chuo University, is that the migration and consolidation processes are controlled by the local density of the bacteria. We show that it is possible within our model to reproduce the morphological diagrams of both bacteria species. Moreover, we model some detailed experiments done by the Chuo University group, obtaining a fine agreement.

  20. Morphological and niche divergence of pinyon pines.

    PubMed

    Ortiz-Medrano, Alejandra; Scantlebury, Daniel Patrick; Vázquez-Lobo, Alejandra; Mastretta-Yanes, Alicia; Piñero, Daniel

    2016-05-01

    The environmental variables that define a species ecological niche should be associated with the evolutionary patterns present in the adaptations that resulted from living in these conditions. Thus, when comparing across species, we can expect to find an association between phylogenetically independent phenotypic characters and ecological niche evolution. Few studies have evaluated how organismal phenotypes might mirror patterns of niche evolution if these phenotypes reflect adaptations. Doing so could contribute on the understanding of the origin and maintenance of phenotypic diversity observed in nature. Here, we show the pattern of niche evolution of the pinyon pine lineage (Pinus subsection Cembroides); then, we suggest morphological adaptations possibly related to niche divergence, and finally, we test for correlation between ecological niche and morphology. We demonstrate that niche divergence is the general pattern within the clade and that it is positively correlated with adaptation.

  1. Feature relevance in morphological galaxy classification

    NASA Astrophysics Data System (ADS)

    Bazell, D.

    2000-08-01

    We investigate the utility of a variety of features in performing morphological galaxy classification using back-propagation neural network classifiers based on a sample of 805 galaxies classified by Naim et al. We derive a total of 22 features from each galaxy image and use these as inputs to a neural network trained using back-propagation. The morphological types are subdivided into two to seven groups, and the relevance of each of the features is examined for each grouping. We use the magnitude of the regularization parameter for each input to determine whether a feature can be eliminated. We then prune the input features of the network, typically down to four features. We examine a number of methods of assessing the performance of the network and determine which works best for our task.

  2. Modeling Light-Dependent Biofilm Morphology

    NASA Astrophysics Data System (ADS)

    Kernan, Chase; Huang, Jean; Christianson, Rebecca

    2013-03-01

    Bacterial aggregates on submerged substrates can produce complex biofilm morphologies that are subject to environmental and metabolic factors. We develop a reductionistic cellular automata model of these structures with the intent of guiding experimentation and explaining prior results. We focus on reproducing the columnar and ``mushroom'' phases of aerobic R. palustris and light-sensitive anaerobic R. palustris, respectively. This light sensitivity requires the novel inclusion of a characteristic light penetration depth in addition to surface tension and media penetration parameters. We quantitatively divide this parameter space into roughly four morphological phases--columnar, mushroom, uniform, and irregular--by examining the resultant convexity defect distribution, horizontal correlation, and coverage as a function of height. Finally, we both validate experimental evidence of these phases and suggest new parameter regimes to investigate empirically.

  3. Giant intracranial aneurysms: morphology and clinical presentation.

    PubMed

    dos Santos, Marcio L Tostes; Spotti, Antonio Ronaldo; dos Santos, Rosangela M Tostes; Borges, Moacir Alves; Ferrari, Antonio Fernandes; Colli, Benedicto Oscar; Tognola, Waldir Antônio

    2013-01-01

    The purpose of this study was to correlate the morphology of giant intracranial aneurysms (GIA) with their clinical presentation. Eighty patients with GIA, 14 males and 66 females, were studied. Univariate and multivariate analyses were made to test the associations between morphological and clinical features. The main locations of the unruptured GIA included the carotid cavernous segment, and for the ruptured GIA, the most frequent were the carotid supraclinoid and middle cerebral arteries. There was a significant association among communicating arteries (CA) of "bad" quality and presence of thrombus and calcification (TC). The risk of rupture is 8 times higher in patients with CA of "bad" quality and 11 times higher in patients without TC. GIA are more frequent in the cavernous segment. There is a high rupture risk in the middle cerebral artery. CA of "bad" quality are associated with TC. The rupture risk is significantly higher in patients without TC.

  4. Morphological cladistic study of coregonine fishes

    USGS Publications Warehouse

    Smith, G.R.; Todd, T.N.

    1992-01-01

    A cladistic analysis of 50 characters from 26 taxa of coregonine fishes and two outgroup taxa yields a phylogenetic tree with two major branches, best summarized as two genera - Prosopium and Coregonus. Presence of teeth on the palatine, long maxillae, and long supra-maxillae are primitive, whereas loss of teeth, short or notched maxillae, and short supermaxillae are derived traits. P. coulteri and C. huntsmani are morphologically and phylogenetically primitive members of their groups. The widespread species, P. cylindraceum and P. williamsoni are morphologically advanced in parallel with the subgenus Coregonus (whitefishes): they share subterminal mouths, short jaws, and reduced teeth. Prosopium gemmifer parallels the ciscoes, subgenus Leucichthys. The whitefishes, C. ussuriensis, C. lavaretus, C. clupeaformis, and C. nasus are a monophyletic group, the subgenus Coregonus. The subgenus Leucichthys is a diverse, relatively plesiomorphic assemblage, widespread in the Holarctic region. This assemblage includes the inconnu, Stenodus.

  5. Dissociation of inflectional and derivational morphology.

    PubMed

    Miceli, G; Caramazza, A

    1988-09-01

    A patient is described who makes morphological errors in spontaneous sentence production and in repetition of single words. The great majority of these errors were substitutions of inflectional affixes. The patient did make some derivational errors in repeating derived words but almost never made such errors for nonderived words. The inflectional errors for adjectives and nouns occurred mostly on the plural forms for nouns and adjectives and on the feminine form for adjectives. For verbs, inflectional errors were produced for all tense, aspect, and mood forms. There were no indications that these latter verb features constrained the form of inflectional errors produced. The results are interpreted as support for the thesis that morphological processes are located in the lexicon but that inflectional and derivational processes constitute autonomous subcomponents of the lexicon.

  6. Multigraft Copolymer Superelastomers: Synthesis Morphology, and Properties

    SciTech Connect

    Uhrig, David; Schlegel, Ralf; Weidisch, Roland; Mays, Jimmy

    2011-01-01

    The synthesis of well-defined multigraft copolymers having a polydiene backbone with polystyrene side chains is briefly reviewed, with particular focus on controlling branch point spacing and branch point functionality. Use of living anionic polymerization and chlorosilane linking chemistry has led to the synthesis of series of materials having regularly spaced trifunctional (comb), tetrafunctional (centipede), and hexafunctional (barbwire) branch points. The morphologies of these materials were characterized by transmission electron microscopy and small-angle X-ray scattering, and it was found that the morphologies were controlled by the local architectural asymmetry associated with each branch point. Mechanical properties studies revealed that such multigraft copolymers represent a new class of thermoplastic elastomers (TPEs) with superior elongation at break and low residual strains as compared to conventional TPEs.

  7. Thermal light ghost imaging based on morphology

    NASA Astrophysics Data System (ADS)

    Chen, Zhipeng; Shi, Jianhong; Zeng, Guihua

    2016-12-01

    The quality of thermal light ghost imaging could be degraded by undersampling noise. This kind of noise is generated because of finite sampling, which could reduce the signal-to-noise ratio (SNR) of ghost imaging and submerge object information. In order to reduce the undersampling noise, we propose a thermal light ghost imaging scheme based on the morphology (GIM). In this scheme, the average size of the undersampling noise can be obtained by computing the second-order correlation function of the ghost imaging system. According to the average size of the undersampling noise, the corresponding structure element can be designed and used in the morphological filter; then, the GIM reconstructed image can be obtained. The experiment results show that the peak signal-to-noise ratio of the GIM reconstructed image can increased by 80% than that of conventional ghost imaging for the same number of measurements.

  8. Engineering particle morphology with microfluidic droplets

    NASA Astrophysics Data System (ADS)

    Kang, Zhanxiao; Kong, Tiantian; Lei, Leyan; Zhu, Pingan; Tian, Xiaowei; Wang, Liqiu

    2016-07-01

    The controlled generation of microparticles with non-spherical features is of increasing importance. Such particles are useful for fundamental studies in areas such as self-assembly, as well as biomedical applications from drug carriers to photonic devices. We propose a simple model that captures the dominating factors controlling the size and morphology of non-spherical particles from phase separated droplets. The validity of our model is verified by comparing the generated non-spherical microparticles by droplet microfluidics. This simple relationship between the dominating factors and the final morphologies enables the production of non-spherical particles with well-defined shapes and tightly-controlled dimensions for a variety of applications from drug delivery vehicles to structural materials.

  9. [Morphologic aspects of angle grinder injury].

    PubMed

    Thurner, W; Pollak, S

    1989-01-01

    Experiments were conducted on soft-tissue and bone preparations to determine the morphological characteristics of angle grinder injuries. The grinding effect of the rotating cutting-off wheel causes severances with local loss of tissue, resulting in tool-specific wound features. Superficial skin notches and (incomplete) severances of bony structures are of particular significance. Mutual trace transfer is a valuable means for determining the tool used and for interpreting the scene.

  10. Dentofacial morphology in Turner syndrome karyotypes.

    PubMed

    Rizell, Sara

    2012-01-01

    The overall aim of this thesis was to study dentofacial morphology in Turner syndrome (TS) versus controls and the influence hereupon from karyotype. One hundred thirty two TS females (5-66 years of age), from Göteborg, Uppsala and Umeå were participating. Cephalometric analysis, cast model analysis concerning palatal height, dental arch morphology and dental crown width were performed. Eighteen primary teeth were analysed in polarized light microscopy, scanning electron microscopy, microradiography and X-ray microanalysis were performed. The TS females were divided according to karyotype into: 1 45,X; 2 45,X/46,XX; 3 isochromosome; 4 other. Compared to healthy females, TS were found to have a flattened cranial base as well as small and retrognathic jaws with a posterior inclination. The maxillary dentoalveolar arch was narrower and longer, while the mandibular dental arch was wider and longer in TS compared to controls. The palatal height did not differ comparing TS and healthy females. The dental crown width was smaller in TS for both permanent and primary teeth. Aberrant elemental composition, prism pattern and lower mineral density were found in TS primary enamel compared to enamel in primary teeth from healthy girls. Turner syndrome karyotype was found having an impact on craniofacial morphology, with the mosaic 45,X/46,XX exhibiting a milder mandibular retrognathism as well as fewer cephalometric variables differing from controls compared to other karyotypes. Also for the dentoalveolar arch morphology the 45,X/46,XX group had fewer variables differing from healthy females. The isochromosome TS group exhibited the smallest dental crown width for several teeth, while 45,X/46,XX hade the largest dental crown with for some teeth and fewer teeth than both 45,X and isochromosomes that differed from controls. Thus, the mosaic 45,X/46,XX seemed to exhibit a milder phenotype, possibly due to presence of healthy 46,XX cell lines.

  11. Morphological plasticity as a bacterial survival strategy.

    PubMed

    Justice, Sheryl S; Hunstad, David A; Cegelski, Lynette; Hultgren, Scott J

    2008-02-01

    Bacteria have evolved complex systems to maintain consistent cell morphologies. Nevertheless, in certain circumstances, bacteria alter this highly regulated process to transform into filamentous organisms. Accumulating evidence attributes important biological roles to filamentation in stressful environments, including, but not limited to, sites of interaction between pathogenic bacteria and their hosts. Filamentation could represent an intended response to specific environmental cues that promote survival amidst the threats of consumption and killing.

  12. Variation in tooth morphology of Pongo pygmaeus.

    PubMed

    Uchida, A

    1998-01-01

    This study examines the postcanine morphology of Pongo pygmaeus, identifying sexual, populational, and subspecific differences, with particular focus on the cusp area proportions. Little differences between the sexes were found in molar shapes, and cusp area proportions can be considered population specific. Inter-population differences are significant between the two Bornean populations, with the Kapuas River as a biogeographic barrier, and are as great as inter-subspecies (Borneo-Sumatra) differences.

  13. Pemphigus vulgaris presenting with multiple lesion morphologies.

    PubMed

    Song, Philip In; Divito, Sherrie J; Kroshinsky, Daniela

    2014-12-14

    Pemphigus vulgaris is an uncommon intraepidermal blistering disorder that typically presents with flaccid bullae or erosions. We report a patient with pemphigus vulgaris who presented with several unusual clinical features: tense bullae with dependently layered pus, true target lesions coalescing into annular configurations, and diffuse desquamation that initially raised concern for toxic epidermal necrolysis. We discuss the differential diagnosis and implications of these morphological findings.

  14. Neuron Morphology Influences Axon Initial Segment Plasticity.

    PubMed

    Gulledge, Allan T; Bravo, Jaime J

    2016-01-01

    In most vertebrate neurons, action potentials are initiated in the axon initial segment (AIS), a specialized region of the axon containing a high density of voltage-gated sodium and potassium channels. It has recently been proposed that neurons use plasticity of AIS length and/or location to regulate their intrinsic excitability. Here we quantify the impact of neuron morphology on AIS plasticity using computational models of simplified and realistic somatodendritic morphologies. In small neurons (e.g., dentate granule neurons), excitability was highest when the AIS was of intermediate length and located adjacent to the soma. Conversely, neurons having larger dendritic trees (e.g., pyramidal neurons) were most excitable when the AIS was longer and/or located away from the soma. For any given somatodendritic morphology, increasing dendritic membrane capacitance and/or conductance favored a longer and more distally located AIS. Overall, changes to AIS length, with corresponding changes in total sodium conductance, were far more effective in regulating neuron excitability than were changes in AIS location, while dendritic capacitance had a larger impact on AIS performance than did dendritic conductance. The somatodendritic influence on AIS performance reflects modest soma-to-AIS voltage attenuation combined with neuron size-dependent changes in AIS input resistance, effective membrane time constant, and isolation from somatodendritic capacitance. We conclude that the impact of AIS plasticity on neuron excitability will depend largely on somatodendritic morphology, and that, in some neurons, a shorter or more distally located AIS may promote, rather than limit, action potential generation.

  15. Evolutionary morphology of the rabbit skull

    PubMed Central

    Sherratt, Emma

    2016-01-01

    The skull of leporids (rabbits and hares) is highly transformed, typified by pronounced arching of the dorsal skull and ventral flexion of the facial region (i.e., facial tilt). Previous studies show that locomotor behavior influences aspects of cranial shape in leporids, and here we use an extensive 3D geometric morphometrics dataset to further explore what influences leporid cranial diversity. Facial tilt angle, a trait that strongly correlates with locomotor mode, significantly predicts the cranial shape variation captured by the primary axis of cranial shape space, and describes a small proportion (13.2%) of overall cranial shape variation in the clade. However, locomotor mode does not correlate with overall cranial shape variation in the clade, because there are two district morphologies of generalist species, and saltators and cursorial species have similar morphologies. Cranial shape changes due to phyletic size change (evolutionary allometry) also describes a small proportion (12.5%) of cranial shape variation in the clade, but this is largely driven by the smallest living leporid, the pygmy rabbit (Brachylagus idahoensis). By integrating phylogenetic history with our geometric morphometric data, we show that the leporid cranium exhibits weak phylogenetic signal and substantial homoplasy. Though these results make it difficult to reconstruct what the ‘ancestral’ leporid skull looked like, the fossil records suggest that dorsal arching and facial tilt could have occurred before the origin of the crown group. Lastly, our study highlights the diversity of cranial variation in crown leporids, and highlights a need for additional phylogenetic work that includes stem (fossil) leporids and includes morphological data that captures the transformed morphology of rabbits and hares. PMID:27688967

  16. Morphology of leaves cuticle by fringe projection

    NASA Astrophysics Data System (ADS)

    Martínez, Amalia; Rayas Alvarez, J. A.; Cordero, Raúl; Balieiro R., Daniela

    2011-10-01

    The development of this work is important in the morphological study of plant parts, specifically in the study of the cuticle of fruits or leaves. The implemented optical technique for fringe projection can identify potential fracture zones which damage the presentation of the fruits impacting business as well as producing them. Specifically, we obtained information on the thickness of a cuticle corresponding to the abaxial surface of a leaf of apple (Malus domestica) of the variety Golden Delicious.

  17. Periodicity of nuclear morphology in human fibroblasts

    PubMed Central

    Seaman, Laura; Meixner, Walter; Snyder, John; Rajapakse, Indika

    2015-01-01

    Motivation: Morphology of the cell nucleus has been used as a key indicator of disease state and prognosis, but typically without quantitative rigor. It is also not well understood how nuclear morphology varies with time across different genetic backgrounds in healthy cells. To help answer these questions we measured the size and shape of nuclei in cell-cycle-synchronized primary human fibroblasts from 6 different individuals at 32 time points over a 75 hour period. Results: The nucleus was modeled as an ellipsoid and its dynamics analyzed. Shape and volume changed significantly over this time. Two prominent frequencies were found in the 6 individuals: a 17 hour period consistent with the cell cycle and a 26 hour period. Our findings suggest that the shape of the nucleus changes over time and thus any time-invariant shape property may provide a misleading characterization of cellular populations at different phases of the cell cycle. The proposed methodology provides a general method to analyze morphological change using multiple time points even for non-live-cell experiments. PMID:26734724

  18. Tool making, hand morphology and fossil hominins

    PubMed Central

    Marzke, Mary W.

    2013-01-01

    Was stone tool making a factor in the evolution of human hand morphology? Is it possible to find evidence in fossil hominin hands for this capability? These questions are being addressed with increasingly sophisticated studies that are testing two hypotheses; (i) that humans have unique patterns of grip and hand movement capabilities compatible with effective stone tool making and use of the tools and, if this is the case, (ii) that there exist unique patterns of morphology in human hands that are consistent with these capabilities. Comparative analyses of human stone tool behaviours and chimpanzee feeding behaviours have revealed a distinctive set of forceful pinch grips by humans that are effective in the control of stones by one hand during manufacture and use of the tools. Comparative dissections, kinematic analyses and biomechanical studies indicate that humans do have a unique pattern of muscle architecture and joint surface form and functions consistent with the derived capabilities. A major remaining challenge is to identify skeletal features that reflect the full morphological pattern, and therefore may serve as clues to fossil hominin manipulative capabilities. Hominin fossils are evaluated for evidence of patterns of derived human grip and stress-accommodation features. PMID:24101624

  19. Facial morphology and obstructive sleep apnea

    PubMed Central

    Capistrano, Anderson; Cordeiro, Aldir; Capelozza, Leopoldino; Almeida, Veridiana Correia; Silva, Priscila Izabela de Castro e; Martinez, Sandra; de Almeida-Pedrin, Renata Rodrigues

    2015-01-01

    Objective: This study aimed at assessing the relationship between facial morphological patterns (I, II, III, Long Face and Short Face) as well as facial types (brachyfacial, mesofacial and dolichofacial) and obstructive sleep apnea (OSA) in patients attending a center specialized in sleep disorders. Methods: Frontal, lateral and smile photographs of 252 patients (157 men and 95 women), randomly selected from a polysomnography clinic, with mean age of 40.62 years, were evaluated. In order to obtain diagnosis of facial morphology, the sample was sent to three professors of Orthodontics trained to classify patients' face according to five patterns, as follows: 1) Pattern I; 2) Pattern II; 3) Pattern III; 4) Long facial pattern; 5) Short facial pattern. Intraexaminer agreement was assessed by means of Kappa index. The professors ranked patients' facial type based on a facial index that considers the proportion between facial width and height. Results: The multiple linear regression model evinced that, when compared to Pattern I, Pattern II had the apnea and hypopnea index (AHI) worsened in 6.98 episodes. However, when Pattern II was compared to Pattern III patients, the index for the latter was 11.45 episodes lower. As for the facial type, brachyfacial patients had a mean AHI of 22.34, while dolichofacial patients had a significantly statistical lower index of 10.52. Conclusion: Patients' facial morphology influences OSA. Pattern II and brachyfacial patients had greater AHI, while Pattern III patients showed a lower index. PMID:26691971

  20. A Primer on Unifying Debris Disk Morphologies

    NASA Astrophysics Data System (ADS)

    Lee, Eve J.; Chiang, Eugene

    2016-08-01

    A “minimum model” for debris disks consists of a narrow ring of parent bodies, secularly forced by a single planet on a possibly eccentric orbit, colliding to produce dust grains that are perturbed by stellar radiation pressure. We demonstrate how this minimum model can reproduce a wide variety of disk morphologies imaged in scattered starlight. Five broad categories of disk shape can be captured: “rings,” “needles,” “ships-and-wakes,” “bars,” and “moths (a.k.a. fans),” depending on the viewing geometry. Moths can also sport “double wings.” We explain the origin of morphological features from first principles, exploring the dependence on planet eccentricity, disk inclination dispersion, and the parent body orbital phases at which dust grains are born. A key determinant in disk appearance is the degree to which dust grain orbits are apsidally aligned. Our study of a simple steady-state (secularly relaxed) disk should serve as a reference for more detailed models tailored to individual systems. We use the intuition gained from our guidebook of disk morphologies to interpret, informally, the images of a number of real-world debris disks. These interpretations suggest that the farthest reaches of planetary systems are perturbed by eccentric planets, possibly just a few Earth masses each.

  1. Physiological identification of morphologically distinct afferent classes innervating the cristae ampullares of the squirrel monkey

    NASA Technical Reports Server (NTRS)

    Lysakowski, A.; Minor, L. B.; Fernandez, C.; Goldberg, J. M.

    1995-01-01

    1. Semicircular-canal afferents in the squirrel monkey were characterized by their resting discharge, discharge regularity, sensitivity to galvanic currents delivered to the ear (beta *), the gain (g2Hz), and phase lead (phi 2Hz) of their response to 2-Hz sinusoidal head rotations, and their antidromic conduction velocity. Discharge regularity was measured by a normalized coefficient of variation (CV*); the higher the CV*, the more irregular the discharge. g2Hz and phi 2Hz were expressed relative to angular head velocity. 2. These physiological measures were used in an attempt to discern the discharge properties of the three morphological classes of afferents innervating the crista. Presumed bouton (B) fibers were identified as slowly conducting afferents. Presumed calyx (C) fibers were recognized by their irregular discharge and low rotational gains. The remaining fibers were considered to be dimorphic (D) units. Single letters (B, C, and D) are used to emphasize that the classification is based on circumstantial evidence and may be wrong for individual fibers. Of the 125 identified fibers, 13 (10%) were B units, 36 (29%) were C units, and 76 (61%) were D units. 3. B units were regularly discharging D units ranged from regularly to irregularly discharging. C units were the most irregularly discharging afferents encountered. The mean resting discharge for the entire sample was 74 spikes/s. Resting rates were similar for regularly discharging B and D units and higher than those for irregularly discharging C and D units. 4. Except for their lower conduction velocities, the discharge properties of B units are indistinguishable from those of regularly discharging D units. Many of the discharge properties of B and D units vary with discharge regularity. There is a strong, positive relation when beta *, g2Hz, or phi 2Hz is plotted against CV*. For beta * or phi 2Hz, C units conform to the relation for B and D units. In contrast, values of g2Hz for C units are three to

  2. Morphology of certain viruses of Salmonid Fishes. I. in vitro studies of some viruses causing Hematopoietic Necrosis

    USGS Publications Warehouse

    Amend, Donald F.; Chambers, Velma C.

    1970-01-01

    An electron microscope study was performed on three virus isolates that caused hematopoietic necrosis in salmonid fishes: infectious hematopoietic necrosis (IHN), Oregon Sockeye Disease (OSD), and Sacramento River Chinook Salmon Disease (SRCD). All three isolates were examined by negative staining of fathead minnow (FHM) monolayer tissue culture concentrates and IHN virus was also examined in thin sections of FHM cells. Viruslike particles were observed in infected tissues, but similar structures were not found in uninfected cultures. All three isolates were bullet-shaped, but oval and truncated forms were also observed. Mean measurements of particles from IHN-virus-infected tissue were 158 × 90 mμ. They consisted of an outer coat 15 mμ thick, a core 60 mμ in diameter, subunits about 5 mμ, and an axial pore about 20 mμ in diameter. These particles also were seen budding from the cytoplasmic membrane. Similar particles from SRCD were 159 × 90 mμ and isolates from OSD were 181 × 91 mμ. The three isolates were morphologically indistinguishable from one another and the greater length of OSD was considered insignificant. IHN, SRCD, and OSD viruses were tentatively placed in the rhabdovirus group, but serological studies are needed to determine if they are antigenically identical or should be included as separate members. Biochemical and physical characteristics of these viruses and a comparison with other salmonid viruses is also discussed.

  3. Ecoregions and stream morphology in eastern Oklahoma

    USGS Publications Warehouse

    Splinter, D.K.; Dauwalter, D.C.; Marston, R.A.; Fisher, W.L.

    2010-01-01

    Broad-scale variables (i.e., geology, topography, climate, land use, vegetation, and soils) influence channel morphology. How and to what extent the longitudinal pattern of channel morphology is influenced by broad-scale variables is important to fluvial geomorphologists and stream ecologists. In the last couple of decades, there has been an increase in the amount of interdisciplinary research between fluvial geomorphologists and stream ecologists. In a historical context, fluvial geomorphologists are more apt to use physiographic regions to distinguish broad-scale variables, while stream ecologists are more apt to use the concept of an ecosystem to address the broad-scale variables that influence stream habitat. For this reason, we designed a study using ecoregions, which uses physical and biological variables to understand how landscapes influence channel processes. Ecoregions are delineated by similarities in geology, climate, soils, land use, and potential natural vegetation. In the fluvial system, stream form and function are dictated by processes observed throughout the fluvial hierarchy. Recognizing that stream form and function should differ by ecoregion, a study was designed to evaluate how the characteristics of stream channels differed longitudinally among three ecoregions in eastern Oklahoma, USA: Boston Mountains, Ozark Highlands, and Ouachita Mountains. Channel morphology of 149 stream reaches was surveyed in 1st- through 4th-order streams, and effects of drainage area and ecoregion on channel morphology was evaluated using multiple regressions. Differences existed (?????0.05) among ecoregions for particle size, bankfull width, and width/depth ratio. No differences existed among ecoregions for gradient or sinuosity. Particle size was smallest in the Ozark Highlands and largest in the Ouachita Mountains. Bankfull width was larger in the Ozark Highlands than in the Boston Mountains and Ouachita Mountains in larger streams. Width/depth ratios of the

  4. Quantitative Morphology of Galaxies Observed in the Ultraviolet

    NASA Technical Reports Server (NTRS)

    Kuchinski, L.; Madore, B.; Trewhella, M.; Freedman, W.

    2000-01-01

    We present a quantitative study of the far-ultraviolet (FUV) and optical morphology in 32 nearby galaxies and estimate the morphological k-correction expected if these objects were observed unevolved at high redshift.

  5. Ecological radiation with limited morphological diversification in salamanders.

    PubMed

    Blankers, Thomas; Adams, D C; Wiens, J J

    2012-04-01

    A major goal of evolutionary biology is to explain morphological diversity among species. Many studies suggest that much morphological variation is explained by adaptation to different microhabitats. Here, we test whether morphology and microhabitat use are related in plethodontid salamanders, which contain the majority of salamander species, and have radiated into a striking diversity of microhabitats. We obtained microhabitat data for 189 species that also had both morphometric and phylogenetic data. We then tested for associations between morphology and microhabitat categories using phylogenetic comparative methods. Associations between morphology and ecology in plethodontids are largely confined to a single clade within one subfamily (Bolitoglossinae), whereas variation in morphology across other plethodontids is unrelated to microhabitat categories. These results demonstrate that ecological radiation and morphological evolution can be largely decoupled in a major clade. The results also offer a striking contrast to lizards, which typically show close relationships between morphology and microhabitat.

  6. Development of Morphological Awareness in Chinese and English.

    ERIC Educational Resources Information Center

    Ku, Yu-Min; Anderson, Richard C.

    2003-01-01

    Investigates the development of morphological awareness in Chinese and English. Indicates that morphological awareness develops with grade level and is strongly related to reading ability. Notes that Chinese students' acquisition of derivational morphology seems to lag behind that of compounding rules, which might reflect the nature of Chinese…

  7. Evidence for Early Morphological Decomposition: Combining Masked Priming with Magnetoencephalography

    ERIC Educational Resources Information Center

    Lehtonen, Minna; Monahan, Philip J.; Poeppel, David

    2011-01-01

    Are words stored as morphologically structured representations? If so, when during word recognition are morphological pieces accessed? Recent masked priming studies support models that assume early decomposition of (potentially) morphologically complex words. The electrophysiological evidence, however, is inconsistent. We combined masked…

  8. An Electrophysiological Investigation of Early Effects of Masked Morphological Priming

    ERIC Educational Resources Information Center

    Morris, Joanna; Grainger, Jonathan; Holcomb, Phillip J.

    2008-01-01

    This experiment examined event-related responses to targets preceded by semantically transparent morphologically related primes (e.g., farmer-farm), semantically opaque primes with an apparent morphological relation (corner-corn), and orthographically, but not morphologically, related primes (scandal-scan) using the masked priming technique…

  9. Morphological Decomposition Based on the Analysis of Orthography

    ERIC Educational Resources Information Center

    Rastle, Kathleen; Davis, Matthew H.

    2008-01-01

    Recent theories of morphological processing have been dominated by the notion that morphologically complex words are decomposed into their constituents on the basis of their semantic properties. In this article we argue that the weight of evidence now suggests that the recognition of morphologically complex words begins with a rapid morphemic…

  10. The Processing of Morphology in Old Age: Evidence from Hebrew

    ERIC Educational Resources Information Center

    Kave, Gitit; Levy, Yonata

    2005-01-01

    Purpose: Taking advantage of the rich morphological structure of Hebrew, the current article aims to examine whether age affects the processing of morphological forms through an investigation of 2 systematic morphological paradigms. Method: Forty-eight young and 48 old Hebrew speakers completed 2 experiments: the 1st investigated sensitivity to…

  11. Assessing Two-Year-Olds' Knowledge of Number Agreement Morphology

    ERIC Educational Resources Information Center

    Blossom, Megan

    2013-01-01

    Previous research in the area of children's knowledge of number agreement morphology has yielded mixed results. Some researchers have found evidence for sensitivity to agreement morphology at as early as 16 months, while others report that children do not comprehend number agreement morphology until as late as five or six years old. Studies of…

  12. Examining the Underlying Dimensions of Morphological Awareness and Vocabulary Knowledge

    ERIC Educational Resources Information Center

    Spencer, Mercedes; Muse, Andrea; Wagner, Richard K.; Foorman, Barbara; Petscher, Yaacov; Schatschneider, Christopher; Tighe, Elizabeth L.; Bishop, M. Denise

    2015-01-01

    We report results from two studies on the underlying dimensions of morphological awareness and vocabulary knowledge in elementary-aged children. In Study 1, 99 fourth-grade students were given multiple measures of morphological awareness and vocabulary. A single factor accounted for individual differences in all morphology and vocabulary…

  13. A Survey of the Measurements of Morphological Productivity

    ERIC Educational Resources Information Center

    Du, Lifang; Zhang, Xuezhong

    2010-01-01

    Morphological productivity is one of the key issues in the study of derivational morphology. This paper makes a survey of the quantitative measurements of morphological productivity so far proposed by different scholars, and tentatively attempts to point out the pros and cons and also feasibility of each measurement, with a view to provide some…

  14. Computer Simulation of Glioma Growth and Morphology

    PubMed Central

    Frieboes, Hermann B.; Lowengrub, John S.; Wise, S.; Zheng, X.; Macklin, Paul; Bearer, Elaine; Cristini, Vittorio

    2007-01-01

    Despite major advances in the study of glioma, the quantitative links between intra-tumor molecular/cellular properties, clinically observable properties such as morphology, and critical tumor behaviors such as growth and invasiveness remain unclear, hampering more effective coupling of tumor physical characteristics with implications for prognosis and therapy. Although molecular biology, histopathology, and radiological imaging are employed in this endeavor, studies are severely challenged by the multitude of different physical scales involved in tumor growth, i.e., from molecular nanoscale to cell microscale and finally to tissue centimeter scale. Consequently, it is often difficult to determine the underlying dynamics across dimensions. New techniques are needed to tackle these issues. Here, we address this multi-scalar problem by employing a novel predictive three-dimensional mathematical and computational model based on first-principle equations (conservation laws of physics) that describe mathematically the diffusion of cell substrates and other processes determining tumor mass growth and invasion. The model uses conserved variables to represent known determinants of glioma behavior, e.g., cell density and oxygen concentration, as well as biological functional relationships and parameters linking phenomena at different scales whose specific forms and values are hypothesized and calculated based on in-vitro and in-vivo experiments and from histopathology of tissue specimens from human gliomas. This model enables correlation of glioma morphology to tumor growth by quantifying interdependence of tumor mass on the microenvironment (e.g., hypoxia, tissue disruption) and on the cellular phenotypes (e.g., mitosis and apoptosis rates, cell adhesion strength). Once functional relationships between variables and associated parameter values have been informed, e.g. from histopathology or intra-operative analysis, this model can be used for disease diagnosis

  15. Structure, morphology, and assembly behavior of kafirin

    SciTech Connect

    Xiao, Jie; Li, Yunqi; Li, Ji; Gonzalez, Alejandro Perez; Xia, Qiuyang; Huang, Qingrong

    2014-12-15

    Prolamins from grains have attracted intensive attention in recent years due to their potential in satisfying the demand for environmentally friendly (biodegradable), abundantly available (sustainable), and cost-effective biomaterials. However, for kafirin, the prolamin from sorghum, its composition, structure, morphology, and self-assembly behaviors have not been fully characterized. In this paper, kafirin was extracted from the whole sorghum grain and found to contain 68, 14, 6, and 12% of α-, β-, and γ-fractions and cross-linked kafirin, respectively. Freeze-dried kafirin contained ~49% α-helix in the solid state. When dissolved in 65% (v/v) isopropanol, 60% (v/v) tert-butanol, and 85% (v/v) ethanol aqueous solvents, the relative α-helix content in kafirin increased with the decrease of solvent polarity. Structural analysis using small-angle X-ray scattering (SAXS) indicated that kafirin (2 mg/mL) took stretched and extended conformations with dimensions of 118 × 15 × 15 and 100 × 11 × 11 Å in 60% tert-butanol and 65% isopropanol, respectively. More elongated conformation of individual kafirin with high-order assembly was observed in 85% ethanol. Protein aggregation occurred as protein concentration increased in its good solvent. The morphology of kafirin assemblies captured by atomic force microscopy (AFM) revealed that kafirin protein took uniform particle morphology at low concentration, and disk-like or rod-like structures resulting from solvent evaporation induced particle interactions emerged at high concentrations. Lastly, these results suggest that both protein concentration and solvent polarity can effectively regulate kafirin assemblies from thick rod-like to slim rod-like structures, a convenient way to tune the fibrillation of prolamin-based biomaterials.

  16. Structure, morphology, and assembly behavior of kafirin

    DOE PAGES

    Xiao, Jie; Li, Yunqi; Li, Ji; ...

    2014-12-15

    Prolamins from grains have attracted intensive attention in recent years due to their potential in satisfying the demand for environmentally friendly (biodegradable), abundantly available (sustainable), and cost-effective biomaterials. However, for kafirin, the prolamin from sorghum, its composition, structure, morphology, and self-assembly behaviors have not been fully characterized. In this paper, kafirin was extracted from the whole sorghum grain and found to contain 68, 14, 6, and 12% of α-, β-, and γ-fractions and cross-linked kafirin, respectively. Freeze-dried kafirin contained ~49% α-helix in the solid state. When dissolved in 65% (v/v) isopropanol, 60% (v/v) tert-butanol, and 85% (v/v) ethanol aqueous solvents,more » the relative α-helix content in kafirin increased with the decrease of solvent polarity. Structural analysis using small-angle X-ray scattering (SAXS) indicated that kafirin (2 mg/mL) took stretched and extended conformations with dimensions of 118 × 15 × 15 and 100 × 11 × 11 Å in 60% tert-butanol and 65% isopropanol, respectively. More elongated conformation of individual kafirin with high-order assembly was observed in 85% ethanol. Protein aggregation occurred as protein concentration increased in its good solvent. The morphology of kafirin assemblies captured by atomic force microscopy (AFM) revealed that kafirin protein took uniform particle morphology at low concentration, and disk-like or rod-like structures resulting from solvent evaporation induced particle interactions emerged at high concentrations. Lastly, these results suggest that both protein concentration and solvent polarity can effectively regulate kafirin assemblies from thick rod-like to slim rod-like structures, a convenient way to tune the fibrillation of prolamin-based biomaterials.« less

  17. Morphologic manifestations of testicular and epididymal toxicity

    PubMed Central

    Vidal, Justin D; Whitney, Katharine M

    2014-01-01

    Histopathologic examination of the testis is the most sensitive means to detect effects on spermatogenesis; however, the complexity of testicular histology, interrelatedness of cell types within the testis, and long duration of spermatogenesis can make assessment of a testicular toxicant challenging. A thorough understanding of the histology and morphologic manifestations of response to injury is critical to successfully identify a testicular effect and to begin to understand the underlying mechanism of action. The basic patterns of response to xenobiotic-induced injury to the testis and epididymis are detailed and discussed. PMID:26413388

  18. Applications of Mathematical Morphology to Range Imagery

    DTIC Science & Technology

    1987-12-23

    is C*(h) given by Mes((XnZ)eB) C {h) = Mes( ZGB ) ■ (3-15) The denominator, Mes(Z Q B), is the total possible number of occurences of B...45] Watson, G.S., "Mathematical Morphology," A Survey of Statistical Design and Linear Models , ed. J.N. Srivastava, pp. 547-53, North-Holland...Processor," Au- tometriya (USSR), Trans, in Autom. and Monit. and Measures (GB), No. 4, pp. 75-78, 1982. A relatively simple software model of a

  19. Morphological characterization of fullerene–androsterone conjugates

    PubMed Central

    Ruiz, Alberto; Suárez, Margarita; Martin, Nazario

    2014-01-01

    Summary Here we report on the self-organization characteristics in water of two diastereomer pairs of fullerene–androsterone hybrids that have the hydrophobic C60 appendage in the A and D ring of the androsterone moiety, respectively. The morphology and particle size in aqueous solution were determined by transmission electron microscopy (TEM) and dynamic light scattering (DLS), with satisfactory agreement between both techniques. In general, these fullerene derivatives are shown to organize into spherical nano-scale structures with diameters in the ranges of 10–20 and 30–50 nm, respectively. PMID:24778962

  20. Morphological properties of vestibulospinal neurons in primates

    NASA Technical Reports Server (NTRS)

    Boyle, Richard; Johanson, Curt

    2003-01-01

    The lateral and medial vestibulospinal tracts constitute the major descending pathways controlling extensor musculature of the body. We examined the axon morphology and synaptic input patterns and targets in the cervical spinal segments from these tract cells using intracellular recording and biocytin labeling in the squirrel monkey. Lumbosacral projecting cells represent a private, and mostly rapid, communication pathway between the dorsal Deiters' nucleus and the motor circuits controlling the lower limbs and tail. The cervical projecting cells provide both redundant and variable synaptic input to spinal cell groups, suggesting both general and specific control of the head and neck reflexes.

  1. [Morphological fibroblastic changes in cytomegalovirus infection].

    PubMed

    Parkhomenko, Iu V; Solnyshkova, T G; Tishkivich, O A; Shakhgil'dian, V I; Nikonova, E A

    2006-01-01

    Cytomegalovirus (CMV) infection is widely spread among population. While immunocompetent patients suffer rarely from this virus, it can lead to a lethal outcome in immunocompromised patients. An electron microscopic study has detected fibroblastic morphological changes of a definite cytodestructive character. The nuclei of some fibroblasts have chromatine condensation. A clear zone arising due to vacuolization near this inclusion may reflect nuclear rearrangement leading to further CMV metamorphosis of the cell. This metamorphosis is characteristic of the changes developing in the cells of different parenchymatous organs.

  2. MORPHOLOGICAL PROPERTIES OF Lyα EMITTERS AT REDSHIFT 4.86 IN THE COSMOS FIELD: CLUMPY STAR FORMATION OR MERGER?

    SciTech Connect

    Kobayashi, Masakazu A. R.; Taniguchi, Yoshiaki; Kajisawa, Masaru; Shioya, Yasuhiro; Nagao, Tohru; Murata, Katsuhiro L.; Koekemoer, Anton M.; Murayama, Takashi; Scoville, Nick Z.; Capak, Peter L.

    2016-03-01

    We investigate morphological properties of 61 Lyα emitters (LAEs) at z = 4.86 identified in the COSMOS field, based on Hubble Space Telescope Advanced Camera for Surveys (ACS) imaging data in the F814W band. Out of the 61 LAEs, we find the ACS counterparts for 54 LAEs. Eight LAEs show double-component structures with a mean projected separation of 0.″63 (∼4.0 kpc at z = 4.86). Considering the faintness of these ACS sources, we carefully evaluate their morphological properties, that is, size and ellipticity. While some of them are compact and indistinguishable from the point-spread function (PSF) half-light radius of 0.″07 (∼0.45 kpc), the others are clearly larger than the PSF size and spatially extended up to 0.″3 (∼1.9 kpc). We find that the ACS sources show a positive correlation between ellipticity and size and that the ACS sources with large size and round shape are absent. Our Monte Carlo simulation suggests that the correlation can be explained by (1) the deformation effects via PSF broadening and shot noise or (2) the source blending in which two or more sources with small separation are blended in our ACS image and detected as a single elongated source. Therefore, the 46 single-component LAEs could contain the sources that consist of double (or multiple) components with small spatial separation (i.e., ≲0.″3 or 1.9 kpc). Further observation with high angular resolution at longer wavelengths (e.g., rest-frame wavelengths of ≳4000 Å) is inevitable to decipher which interpretation is adequate for our LAE sample.

  3. Angel lichen moth abundance and morphology data

    USGS Publications Warehouse

    Metcalfe, Anya; Kennedy, Theodore A.; Muehlbauer, Jeffrey D.

    2016-01-01

    Two unique datasets on the abundance and morphology of the angel lichen moth ( Cisthene angelus) in Grand Canyon, Arizona, USA were compiled to describe the phenology and life history of this common, but poorly known, species. The abundance data were collected from 2012 to 2013 through a collaboration with river runners in Grand Canyon National Park. These citizen scientists deployed light traps from their campsites for one hour each night of their expedition. Insects were preserved in ethanol on site, and returned to the Southwest Biological Science Center in Flagstaff, Arizona for analysis in the laboratory. A total of 2,437 light trap samples were sorted through, 903 of which contained C. angelus. In total, 73,841 C. angelus were identified and enumerated to create the abundance data set. The morphology dataset is based on a subset of 28 light trap samples from sampling year 2012 (14 from spring and 14 from fall.) It includes gender and forewing lengths for 2,674 individual moths and dry weights for 1,102 of those individuals.

  4. Morphology and Structures of Nearby Dwarf Galaxies

    NASA Astrophysics Data System (ADS)

    Seo, Mira; Ann, HongBae

    2015-08-01

    We performed an analysis of the structure of nearby dwarf galaxies based on a 2-dimensional decomposition of galaxy images using GALFIT. The present sample consists of ~1,100 dwarf galaxies with redshift less than z = 0.01, which is is derived from the morphology catalog of the Visually classified galaxies in the local universe (Ann, Seo, and Ha 2015). In this catalog, dwarf galaxies are divided into 5 subtypes: dS0, dE, dSph, dEbc, dEblue with distinction of the presence of nucleation in dE, dSph, and dS0. We found that dSph and dEblue galaxies are fainter than other subtypes of dwarf galaxies. In most cases, single component, represented by the Sersic profile with n=1~1.5, well describes the luminosity distribution of dwarf galaxies in the present sample. However, a significant fraction of dS0, dEbc, and dEbue galaxies show sub-structures such as spiral arms and rings. We will discuss the morphology dependent evolutionary history of the local dwarf galaxies.

  5. Morphological study of the hoof in yak.

    PubMed

    Yang, X; Ren, X; Yu, S; Cui, Y

    2016-01-01

    The fore- and hindlimb of yak have been studied by the gross anatomical methods and standard histological techniques. The artery of ungula was also determined by X-ray and acrylonitrile-butadiene-styrene casting. Anatomical features of the forelimb of yak resemble those of hindlimb, including hoof periphery, hoof coronal, hoof wall, hoof sole, and hoof sphere. The forelimb and hindlimb are almost the same in histological structure. The epidermis comprised all 5 strata: stratum corneum, stratum lucidum, stratum granulosum, stratum spinosum and stratum basale. The papillary layers and dermal lamellae contained a variable amount of capillary as well as collagen and elastic fibres. Many venules and arteriovenous anastomosis were distributed among the reticular layer. Subcutaneous tissue was composed of rich adipose and connective tissue in hoof periphery, hoof coronal, and, especially, hoof sphere. Major arteria in forelimb of yak include arteria digitalis palmaris communis III and arteriae digitales palmares propriae III and IV axialis. Those in hindlimb include arteria digitalis plantaris communis III and arteria digitalis plantaris propria III and IV axialis. Our findings highlight the main morphological features of yak and provide a morphological basis useful to researchers using yak hoof.

  6. Genetic and morphologic features for melanoma classification

    PubMed Central

    Broekaert, Sigrid M.C.; Roy, Ritu; Okamoto, Ichiro; van den Oord, Joost; Bauer, Jürgen; Garbe, Claus; Barnhill, Raymond L.; Busam, Klaus J.; Cochran, Alistair J.; Cook, Martin G.; Elder, David E.; McCarthy, Stanley W.; Mihm, Martin C; Schadendorf, Dirk; Scolyer, Richard A.; Spatz, Alain; Bastian, Boris C.

    2011-01-01

    Summary Melanoma is comprised of biologically distinct subtypes. The defining clinical, histomorphologic and molecular features are not fully established. This study sought to validate the association between genetic and histomorphologic features previously described, determine their reproducibility, and association with important clinical variables. Detailed clinical and histomorphologic features of 365 primary cutaneous melanomas were assessed by 11 pathologists and correlated with mutation status of BRAF and NRAS. There was substantial agreement in the quantitative assessment of histomorphologic features showing similar or better interobserver reproducibility than the established WHO classification scheme. We confirmed that melanomas with BRAF mutations showed characteristic morphologic features (p<0.0001) and metastasized more frequently to regional lymph nodes (p=0.046). Importantly, melanomas without mutations were a heterogeneous group, with a subset having very similar features clinical and morphological features than those with BRAF mutation raising the possibility that they are biologically related. Our study confirms an association between histomorphologic features, mutation status and pattern of metastasis, providing criteria for a refined melanoma classification aimed at defining biologically homogeneous disease subgroups. PMID:20874733

  7. The Morphology of Emulsion Polymerized Latex Particles

    DOE R&D Accomplishments Database

    Wignall, G. D.; Ramakrishnan, V. R.; Linne, M. A.; Klein, A.; Sperling, L. H.; Wai, M. P.; Gelman, R. A.; Fatica, M. G.; Hoerl, R. H.; Fisher, L. W.

    1987-11-01

    Under monomer starved feed conditions, emulsion polymerization of perdeuterated methyl methacrylate and styrene in the presence of preformed polymethylmethacrylate latexes resulted in particles with a core-shell morphology, as determined by small-angle neutron scattering (SANS) analysis for a hollow sphere. The locus of polymerization of the added deuterated monomer is therefore at the particle surface. In similar measurements a statistical copolymer of styrene and methyl methacrylate was used as seed particles for further polymerization of trideuteromethyl methacrylate. The resulting polymer latex was again shown to have a core-shell morphological structure as determined by SANS. SANS experiments were also undertaken on polystyrene latexes polymerized by equilibrium swelling methods, with deuterated polymer forming the first or second step. The experiments covered a molecular weight range of 6 x 10{sup 4} 10{sup 6} the molecular weights are consistent with the experimental errors, indicating that the deuterium labeled molecules are randomly distributed in the latex. These results led to the finding that the polymer chains were constrained in the latex particles by factors of 2 to 4 from the relaxed coil dimensions. For M < 10{sup 6} g/mol SANS gave zero angle scattering intensities much higher than expected on the basis of a random distribution of labeled molecules. Several models were examined, including the possible development of core-shell structures at lower molecular weights.

  8. Quantification of the Dental Morphology of Orangutans

    PubMed Central

    Nambiar, P.; John, J.; Al-Amery, Samah M.; Purmal, K.; Chai, W. L.; Ngeow, W. C.; Mohamed, N. H.; Vellayan, S.

    2013-01-01

    Orangutans are believed to have close biological affinities to humans. Teeth being the hardest tissue provide useful information on primate evolution. Furthermore, knowledge of the pulp chamber and root canal morphology is important for dental treatment. A female Bornean orangutan and a Sumatran male orangutan skull were available for this study. Both of their dentitions, comprising 50 teeth, were scanned employing the cone-beam computed tomography for both metrical and nonmetrical analyses. Measurements included tooth and crown length, root length, enamel covered crown height, root canal length (posterior teeth), length of pulpal space (anterior teeth), and root canal width. Nonmetrical parameters included number of canals per root, number of foramina in each root, and root canal morphology according to Vertucci's classification. It was found that the enamel covered crown height was the longest in the upper central incisors although the canine was the longest amongst the anterior teeth. Both the upper premolars were three-rooted while the lower second premolar of the Sumatran orangutan was two-rooted, with two foramina. The mandibular lateral incisors of the Bornean orangutan were longer than the central incisors, a feature similar to humans. In addition, secondary dentine deposition was noticed, a feature consistent with aged humans. PMID:24348143

  9. Fibonacci thresholding: signal representation and morphological filters

    NASA Astrophysics Data System (ADS)

    Grigoryan, Artyom M.; Agaian, Sos S.

    2014-02-01

    A new weighted thresholding concept is presented, which is used for the set-theoretical representation of signals, the producing new signals containing a large number of key features that are in the original signals and the design new morphological filters. Such representation maps many operations of non binary signal and image processing to the union of the simple operations over the binary signals and images. The weighted thresholding is invariant under the morphological transformations, including the basic ones, erosion and dilation. The main idea of using the weighted thresholding is in the choice of the special level of thresholding on which we can concentrate all our attention for the future processing. Together with arithmetical thresholding the so-called Fibonacci levels are chosen because of many interesting properties; one of them is the effective decomposition of the median filter. Experimental results show that the Fibonacci thresholding is much promised and can be used for many applications, including the image enhancement, segmentation, and edge detection.

  10. Solutocapillary Convection Effects on Polymeric Membrane Morphology

    NASA Technical Reports Server (NTRS)

    Krantz, William B.; Todd, Paul W.; Kinagurthu, Sanjay

    1996-01-01

    Macro voids are undesirable large pores in membranes used for purification. They form when membranes are cast as thin films on a smooth surface by evaporating solvent (acetone) from a polymer solution. There are two un-tested hypotheses explaining the growth of macro voids. One states that diffusion of the non-solvent (water) is solely responsible, while the other states that solutocapillary convection is the primary cause of macro void growth. Solutocapillary convection is flow-caused by a concentration induced surface-tension gradient. Macrovoid growth in the former hypothesis is gravity independent, while in the latter it is opposed by gravity. To distinguish between these two hypotheses, experiments were designed to cast membranes in zero-gravity. A semi-automated apparatus was designed and built for casting membranes during the 20 secs of zero-g time available in parabolic aircraft flight such as NASA's KC-135. The phase changes were monitored optically, and membrane morphology was evaluated by scanning electron microscopy (SEM). These studies appear to be the first quantitative studies of membrane casting in micro-gravity which incorporate real-time data acquisition. Morphological studies of membranes cast at 0, 1, and 1.8 g revealed the presence of numerous, sparse and no macrovoids respectively. These results are consistent with the predictions of the solutocapillary hypothesis of macrovoid growth.

  11. What limits the morphological disparity of clades?

    PubMed Central

    Oyston, Jack W.; Hughes, Martin; Wagner, Peter J.; Gerber, Sylvain; Wills, Matthew A.

    2015-01-01

    The morphological disparity of species within major clades shows a variety of trajectory patterns through evolutionary time. However, there is a significant tendency for groups to reach their maximum disparity relatively early in their histories, even while their species richness or diversity is comparatively low. This pattern of early high-disparity suggests that there are internal constraints (e.g. developmental pleiotropy) or external restrictions (e.g. ecological competition) upon the variety of morphologies that can subsequently evolve. It has also been demonstrated that the rate of evolution of new character states decreases in most clades through time (character saturation), as does the rate of origination of novel bodyplans and higher taxa. Here, we tested whether there was a simple relationship between the level or rate of character state exhaustion and the shape of a clade's disparity profile: specifically, its centre of gravity (CG). In a sample of 93 extinct major clades, most showed some degree of exhaustion, but all continued to evolve new states up until their extinction. Projection of states/steps curves suggested that clades realized an average of 60% of their inferred maximum numbers of states. Despite a weak but significant correlation between overall levels of homoplasy and the CG of clade disparity profiles, there were no significant relationships between any of our indices of exhaustion curve shape and the clade disparity CG. Clades showing early high-disparity were no more likely to have early character saturation than those with maximum disparity late in their evolution. PMID:26640649

  12. The morphology of emulsion polymerized latex particles

    SciTech Connect

    Wignall, G.D.; Ramakrishnan, V.R.; Linne, M.A.; Klein, A.; Sperling, L.H.; Wai, M.P.; Gelman, R.A.; Fatica, M.G.; Hoerl, R.H.; Fisher, L.W.

    1987-11-01

    Under monomer starved feed conditions, emulsion polymerization of perdeuterated methyl methacrylate and styrene in the presence of preformed polymethylmethacrylate latexes resulted in particles with a core-shell morphology, as determined by small-angle neutron scattering (SANS) analysis for a hollow sphere. The locus of polymerization of the added deuterated monomer is therefore at the particle surface. In similar measurements a statistical copolymer of styrene and methyl methacrylate was used as seed particles for further polymerization of trideuteromethyl methacrylate. The resulting polymer latex was again shown to have a core-shell morphological structre as determined by SANS. SANS experiments were also undertaken on polystyrene latexes polymerized by equilibrium swelling methods, with deuterated polymer forming the first or second step. The experiments covered a molecular weight range of 6 x 10/sup 4/ < M < 6 x 10/sup 6/ g/mol. For M > 10/sup 6/ the molecular weights are consistent with the experimental errors, indicating that the deuterium labeled molecules are randomly distributed in the latex. These results led to the finding that the polymer chains were constrained in the latex particles by factors of 2 to 4 from the relaxed coil dimensions. For M < 10/sup 6/ g/mol SANS gave zero angle scattering intensities much higher than expected on the basis of a random distribution of labeled molecules. Several models were examined, including the possible development of core-shell structures at lower molecular weights. 25 refs., 6 figs., 3 tabs.

  13. Morphological properties of mouse retinal ganglion cells.

    PubMed

    Coombs, J; van der List, D; Wang, G-Y; Chalupa, L M

    2006-06-19

    The mouse retina offers an increasingly valuable model for vision research given the possibilities for genetic manipulation. Here we assess how the structural properties of mouse retinal ganglion cells relate to the stratification pattern of the dendrites of these neurons within the inner plexiform layer. For this purpose, we used 14 morphological measures to classify mouse retinal ganglion cells parametrically into different clusters. Retinal ganglion cells were labeled in one of three ways: Lucifer Yellow injection, 'DiOlistics' or transgenic expression of yellow fluorescent protein. The resulting analysis of 182 cells revealed 10 clusters of monostratified cells, with dendrites confined to either On or Off sublaminae of the inner plexiform layer, and four clusters of bistratified cells, dendrites spanning the On and Off sublaminae. We also sought to establish how these parametrically identified retinal ganglion cell clusters relate to cell types identified previously on the basis of immunocytochemical staining and the expression of yellow fluorescent protein. Cells labeled with an antibody against melanopsin were found to be located within a single cluster, while those labeled with the SMI-32 antibody were in four different clusters. Yellow fluorescent protein expressing cells were distributed within 13 of the 14 clusters identified here, which demonstrates that yellow fluorescent protein expression is a useful method for labeling virtually the entire population of mouse retinal ganglion cells. Collectively, these findings provide a valuable baseline for future studies dealing with the effects of genetic mutations on the morphological development of these neurons.

  14. EXPLORING THE MORPHOLOGY OF RAVE STELLAR SPECTRA

    SciTech Connect

    Matijevic, G.; Zwitter, T.; Bienayme, O.; Siebert, A.; Bland-Hawthorn, J.; Boeche, C.; Grebel, E. K.; Freeman, K. C.; Gibson, B. K.; Gilmore, G.; Helmi, A.; Munari, U.; Navarro, J.; Parker, Q. A.; Reid, W.; Seabroke, G.; Siviero, A.; Steinmetz, M.; Williams, M.; Watson, F. G.; and others

    2012-06-01

    The RAdial Velocity Experiment (RAVE) is a medium-resolution (R {approx} 7500) spectroscopic survey of the Milky Way that has already obtained over half a million stellar spectra. They present a randomly selected magnitude-limited sample, so it is important to use a reliable and automated classification scheme that identifies normal single stars and discovers different types of peculiar stars. To this end, we present a morphological classification of {approx}350, 000 RAVE survey stellar spectra using locally linear embedding, a dimensionality reduction method that enables representing the complex spectral morphology in a low-dimensional projected space while still preserving the properties of the local neighborhoods of spectra. We find that the majority of all spectra in the database ({approx} 90%-95%) belong to normal single stars, but there is also a significant population of several types of peculiars. Among them, the most populated groups are those of various types of spectroscopic binary and chromospherically active stars. Both of them include several thousands of spectra. Particularly the latter group offers significant further investigation opportunities since activity of stars is a known proxy of stellar ages. Applying the same classification procedure to the sample of normal single stars alone shows that the shape of the projected manifold in two-dimensional space correlates with stellar temperature, surface gravity, and metallicity.

  15. Morphological Heterogeneity and Attachment of Phaeobacter inhibens

    PubMed Central

    Segev, Einat; Tellez, Adèle; Vlamakis, Hera; Kolter, Roberto

    2015-01-01

    The Roseobacter clade is a key group of bacteria in the ocean exhibiting diverse metabolic repertoires and a wide range of symbiotic life-styles. Many Roseobacters possess remarkable capabilities of attachment to both biotic and abiotic surfaces. When attached to each other, these bacteria form multi-cellular structures called rosettes. Phaeobacter inhibens, a well-studied Roseobacter, exhibits various cell sizes and morphologies that are either associated with rosettes or occur as single cells. Here we describe the distribution of P. inhibens morphologies and rosettes within a population. We detect an N-acetylglucosamine-containing polysaccharide on the poles of some cells and at the center of all rosettes. We demonstrate that rosettes are formed by the attachment of individual cells at the polysaccharide-containing pole rather than by cell division. Finally, we show that P. inhibens attachment to abiotic surfaces is hindered by the presence of DNA from itself, but not from other bacteria. Taken together, our findings demonstrate that cell adhesiveness is likely to play a significant role in the life cycle of P. inhibens as well as other Roseobacters. PMID:26560130

  16. Radio Source Morphology: 'nature or nuture'?

    NASA Astrophysics Data System (ADS)

    Banfield, Julie; Emonts, Bjorn; O'Sullivan, Shane

    2012-10-01

    Radio sources, emanating from supermassive black-holes in the centres of active galaxies, display a large variety of morphological properties. It is a long-standing debate to what extent the differences between various types of radio sources are due to intrinsic properties of the central engine (`nature') or due to the properties of the interstellar medium that surrounds the central engine and host galaxy (`nurture'). Settling this `nature vs. nurture' debate for nearby radio galaxies, which can be studied in great detail, is vital for understanding the properties and evolution of radio galaxies throughout the Universe. We propose to observe the radio galaxy NGC 612 where previous observations have detected the presence of a large-scale HI bridge between the host galaxy and a nearby galaxy NGC 619. We request a total of 13 hrs in the 750m array-configuration to determine whether or not the 100 kpc-scale radio source morphology is directly related to the intergalactic distribution of neutral hydrogen gas.

  17. Emerging brain morphologies from axonal elongation

    PubMed Central

    Holland, Maria A.; Miller, Kyle E.; Kuhl, Ellen

    2015-01-01

    Understanding the characteristic morphology of our brain remains a challenging, yet important task in human evolution, developmental biology, and neurosciences. Mathematical modeling shapes our understanding of cortical folding and provides functional relations between cortical wavelength, thickness, and stiffness. Yet, current mathematical models are phenomenologically isotropic and typically predict non-physiological, periodic folding patterns. Here we establish a mechanistic model for cortical folding, in which macroscopic changes in white matter volume are a natural consequence of microscopic axonal growth. To calibrate our model, we consult axon elongation experiments in chick sensory neurons. We demonstrate that a single parameter, the axonal growth rate, explains a wide variety of in vitro conditions including immediate axonal thinning and gradual thickness restoration. We embed our axonal growth model into a continuum model for brain development using axonal orientation distributions motivated by diffusion spectrum imaging. Our simulations suggest that white matter anisotropy - as an emergent property from directional axonal growth - intrinsically induces symmetry breaking, and predicts more physiological, less regular morphologies with regionally varying gyral wavelengths and sulcal depths. Mechanistic modeling of brain development could establish valuable relationships between brain connectivity, brain anatomy, and brain function. PMID:25824370

  18. Morphological adaptations to marine life in snakes.

    PubMed

    Brischoux, François; Shine, Richard

    2011-05-01

    We investigated morphological adaptations to aquatic life within animals that exhibit a structurally simple, elongate body form, i.e., snakes. This linear body plan should impose different biomechanical constraints than the classical streamlined body shape associated with propulsion by fins, feet, or wings. Our measurements of general body shape of terrestrial, amphibious, and marine snakes (all from the same phylogenetic lineage, the Elapidae) show that seasnakes display specialized morphological attributes for life in water. Most notably, the cross-sectional body shape is circular in terrestrial snakes but dorso-ventrally elongated in seasnakes (due to a prominent ventral keel); amphibious species (sea kraits) exhibit an intermediate shape. The tail of amphibious and marine species (a major propulsive structure during swimming) is higher and thinner than in terrestrial snakes (i.e., paddle-shaped) but shorter relative to body length. The evolution of a laterally compressed shape has been achieved by an increase in body height rather than a decrease in body width, possibly reflecting selection for more effective propulsive thrust, and for an ability to maintain hydrodynamic efficiency despite the minor bodily distension inevitably caused by prey items and developing offspring.

  19. Endobronchial ultrasound: morphological predictors of benign disease.

    PubMed

    Gogia, Pratibha; Insaf, Tabassum Z; McNulty, William; Boutou, Afroditi; Nicholson, Andrew G; Zoumot, Zaid; Shah, Pallav L

    2016-01-01

    The objective of this study was to assess the utility of endobronchial ultrasound (EBUS) morphology of lymph nodes in predicting benign cytology of transbronchial needle aspirates in a prospective observational study. Five ultrasonic morphological characteristics of mediastinal and hilar lymph nodes were recorded: size, shape, margins, echogenic appearance and the presence of a central blood vessel. These characteristics were correlated with the final diagnosis. A total of 402 consecutive patients (237 males and 165 females) undergoing EBUS were studied. The final diagnosis was malignant disease in 244 (60.6%) and benign disease in 153 (38.05%) subjects. Out of 740 sampled nodes, in 463 (62.6%) malignant cells were identified, whereas in 270 (36.5%) nodes, no malignant cells were identified. On univariate analysis small size, triangular shape and the presence of a central vessel were predictive of a benign aetiology. In the final multivariate model, a predictive probability of 0.811 (95% CI 0.72-0.91) for benign disease was found if lymph node size was <10 mm and a central vessel was present. Sonographic appearances of lymph nodes improve the predictive probability of EBUS for benign aetiologies, and may reduce the number of nodes requiring sampling and the need for further invasive investigations.

  20. What limits the morphological disparity of clades?

    PubMed

    Oyston, Jack W; Hughes, Martin; Wagner, Peter J; Gerber, Sylvain; Wills, Matthew A

    2015-12-06

    The morphological disparity of species within major clades shows a variety of trajectory patterns through evolutionary time. However, there is a significant tendency for groups to reach their maximum disparity relatively early in their histories, even while their species richness or diversity is comparatively low. This pattern of early high-disparity suggests that there are internal constraints (e.g. developmental pleiotropy) or external restrictions (e.g. ecological competition) upon the variety of morphologies that can subsequently evolve. It has also been demonstrated that the rate of evolution of new character states decreases in most clades through time (character saturation), as does the rate of origination of novel bodyplans and higher taxa. Here, we tested whether there was a simple relationship between the level or rate of character state exhaustion and the shape of a clade's disparity profile: specifically, its centre of gravity (CG). In a sample of 93 extinct major clades, most showed some degree of exhaustion, but all continued to evolve new states up until their extinction. Projection of states/steps curves suggested that clades realized an average of 60% of their inferred maximum numbers of states. Despite a weak but significant correlation between overall levels of homoplasy and the CG of clade disparity profiles, there were no significant relationships between any of our indices of exhaustion curve shape and the clade disparity CG. Clades showing early high-disparity were no more likely to have early character saturation than those with maximum disparity late in their evolution.

  1. Craniofacial morphology in children with cystic fibrosis.

    PubMed

    Hellsing, E; Brattström, V; Strandvik, B

    1992-04-01

    Cystic fibrosis (CF) is a hereditary metabolic disorder with clinical symptoms of abnormal mucus production. This blocks the airways, gives pancreatic insufficiency, and increases sweat electrolytes. The progressive respiratory disease often leads to respiratory insufficiency and cor pulmonale. The aim of the present investigation was to examine the facial morphology in children with cystic fibrosis. The sample comprised 11 children with cystic fibrosis, who were divided in two groups, one with gastrointestinal disorders and the other with predominantly respiratory insufficiency. Eleven healthy children with normal occlusions were selected as controls. Lateral skull radiographs obtained in natural head posture were digitized, and linear and angular variables for the different groups calculated and compared statistically. The cystic fibrosis group showed open bite, decreased posterior facial height, increased mandibular and craniocervical inclination. Additionally, within the CF-group, the children with respiratory insufficiency differed more from the controls than the children with gastrointestinal disorders. Despite the small number of subjects, the facial morphology of the CF children showed a similar pattern to that of children with nasal respiratory obstruction due to enlarged adenoids or tonsils.

  2. Dynamic Morphologies of Microscale Droplet Interface Bilayers

    SciTech Connect

    Mruetusatorn, Prachya; Boreyko, Jonathan B; Sarles, Stephen A; Venkatesan, Guru; Hayes, Douglas G; Collier, Pat

    2014-01-01

    Droplet interface bilayers (DIBs) are a powerful platform for studying the dynamics of synthetic cellular membranes; however, very little has been done to exploit the unique dynamical features of DIBs. Here, we generate microscale droplet interface bilayers ( DIBs) by bringing together femtoliter-volume water droplets in a microfluidic oil channel, and characterize morphological changes of the DIBs as the droplets shrink due to evaporation. By varying the initial conditions of the system, we identify three distinct classes of dynamic morphology. (1) Buckling and Fission: When forming DIBs using the lipid-out method (lipids in oil phase), lipids in the shrinking monolayers continually pair together and slide into the bilayer to conserve their mass. As the bilayer continues to grow, it becomes confined, buckles, and eventually fissions one or more vesicles. (2) Uniform Shrinking: When using the lipid-in method (lipids in water phase) to form DIBs, lipids uniformly transfer from the monolayers and bilayer into vesicles contained inside the water droplets. (3) Stretching and Unzipping: Finally, when the droplets are pinned to the wall(s) of the microfluidic channel, the droplets become stretched during evaporation, culminating in the unzipping of the bilayer and droplet separation. These findings offer a better understanding of the dynamics of coupled lipid interfaces.

  3. Cortex and amygdala morphology in psychopathy.

    PubMed

    Boccardi, Marina; Frisoni, Giovanni B; Hare, Robert D; Cavedo, Enrica; Najt, Pablo; Pievani, Michela; Rasser, Paul E; Laakso, Mikko P; Aronen, Hannu J; Repo-Tiihonen, Eila; Vaurio, Olli; Thompson, Paul M; Tiihonen, Jari

    2011-08-30

    Psychopathy is characterized by abnormal emotional processes, but only recent neuroimaging studies have investigated its cerebral correlates. The study aim was to map local differences of cortical and amygdalar morphology. Cortical pattern matching and radial distance mapping techniques were used to analyze the magnetic resonance images of 26 violent male offenders (age: 32±8) with psychopathy diagnosed using the Psychopathy Checklist-Revised (PCL-R) and no schizophrenia spectrum disorders, and in matched controls (age: 35± sp="0.12"/>11). The cortex displayed up to 20% reduction in the orbitofrontal and midline structures (corrected p<0.001 bilaterally). Up to 30% tissue reduction in the basolateral nucleus, and 10-30% enlargement effects in the central and lateral nuclei indicated abnormal structure of the amygdala (corrected p=0.05 on the right; and symmetrical pattern on the left). Psychopathy features specific morphology of the main cerebral structures involved in cognitive and emotional processing, consistent with clinical and functional data, and with a hypothesis of an alternative evolutionary brain development.

  4. Ultrastructural Morphology of Sperm from Human Globozoospermia.

    PubMed

    Ricci, Giuseppe; Andolfi, Laura; Zabucchi, Giuliano; Luppi, Stefania; Boscolo, Rita; Martinelli, Monica; Zweyer, Marina; Trevisan, Elisa

    2015-01-01

    Globozoospermia is a rare disorder characterized by the presence of sperm with round head, lacking acrosome. Coiling tail around the nucleus has been reported since early human studies, but no specific significance has conferred it. By contrast, studies on animal models suggest that coiling tail around the nucleus could represent a crucial step of defective spermatogenesis, resulting in round-headed sperm. No observations, so far, support the transfer of this hypothesis to human globozoospermia. The purpose of this work was to compare ultrastructural morphology of human and mouse model globozoospermic sperm. Sperm have been investigated by using scanning and transmission electron microscopy. The images that we obtained show significant similarities to those described in GOPC knockout mice, an animal model of globozoospermia. By using this model as reference, we were able to identify the probable steps of the tail coiling process in human globozoospermia. Although we have no evidence that there is the same pathophysiology in man and knocked-out mouse, the similarities between these ultrastructural observations in human and those in the experimental model are very suggestive. This is the first demonstration of the existence of relevant morphological homologies between the tail coiling in animal model and human globozoospermia.

  5. Ultrastructural Morphology of Sperm from Human Globozoospermia

    PubMed Central

    Ricci, Giuseppe; Andolfi, Laura; Zabucchi, Giuliano; Luppi, Stefania; Boscolo, Rita; Martinelli, Monica; Zweyer, Marina; Trevisan, Elisa

    2015-01-01

    Globozoospermia is a rare disorder characterized by the presence of sperm with round head, lacking acrosome. Coiling tail around the nucleus has been reported since early human studies, but no specific significance has conferred it. By contrast, studies on animal models suggest that coiling tail around the nucleus could represent a crucial step of defective spermatogenesis, resulting in round-headed sperm. No observations, so far, support the transfer of this hypothesis to human globozoospermia. The purpose of this work was to compare ultrastructural morphology of human and mouse model globozoospermic sperm. Sperm have been investigated by using scanning and transmission electron microscopy. The images that we obtained show significant similarities to those described in GOPC knockout mice, an animal model of globozoospermia. By using this model as reference, we were able to identify the probable steps of the tail coiling process in human globozoospermia. Although we have no evidence that there is the same pathophysiology in man and knocked-out mouse, the similarities between these ultrastructural observations in human and those in the experimental model are very suggestive. This is the first demonstration of the existence of relevant morphological homologies between the tail coiling in animal model and human globozoospermia. PMID:26436098

  6. Examining the Underlying Dimensions of Morphological Awareness and Vocabulary Knowledge.

    PubMed

    Spencer, Mercedes; Muse, Andrea; Wagner, Richard K; Foorman, Barbara; Petscher, Yaacov; Schatschneider, Christopher; Tighe, Elizabeth L; Bishop, M Denise

    2015-09-01

    We report results from two studies on the underlying dimensions of morphological awareness and vocabulary knowledge in elementary-aged children. In Study 1, 99 fourth-grade students were given multiple measures of morphological awareness and vocabulary. A single factor accounted for individual differences in all morphology and vocabulary assessments. Study 2 extended these results by giving 90 eighth-grade students expanded measures of vocabulary and morphology that assessed (a) definitional knowledge, (b) usage, (c) relational knowledge, and (d) knowledge of morphological variants, with each potential aspect of knowledge assessed using an identical set of 23 words to control for differential knowledge of specific vocabulary items. Results indicated that a single-factor model that encompassed morphological and vocabulary knowledge provided the best fit to the data. Finally, explanatory item response modeling was used to investigate sources of variance in the vocabulary and morphological awareness tasks we administered. Implications for assessment and instruction are discussed.

  7. Contributions of Morphological Skill to Children's Essay Writing

    PubMed Central

    Northey, Mary; McCutchen, Deborah; Sanders, Elizabeth A.

    2015-01-01

    Morphological skills have previously been found to reliably predict reading skill, including word reading, vocabulary, and comprehension. However, less is known about how morphological skills might contribute to writing skill, aside from its well-documented role in the development of spelling. This correlational study examines whether morphological skill, as measured by a sentence generation task tapping both derivational morphology and meta-syntactic skills, predicts performance on a standardized essay writing task for fifth- and eighth-grade U.S. students (N = 233), after controlling for grade level, comprehension, and writing fluency. Multilevel analyses indicated that morphological skill and writing fluency were each uniquely predictive of essay quality, and this finding was consistent regardless of whether accurate spelling was required in the morphological task. Our results suggest that morphological skills play an important role in writing, as has been previously documented in reading and spelling. PMID:26957783

  8. Minding Morphology: How Morphological Awareness Relates to Reading for English Language Learners

    ERIC Educational Resources Information Center

    Goodwin, Amanda P.; Huggins, A. Corinne; Carlo, Maria S.; August, Diane; Calderon, Margarita

    2013-01-01

    This study explored subprocesses of reading for 157 fifth grade Spanish-speaking English language learners (ELLs) by examining whether morphological awareness made a unique contribution to reading comprehension beyond a strong covariate-phonological decoding. The role of word reading and reading vocabulary as mediators of this relationship was…

  9. Orientation and morphology development in electrospun nanofibers

    NASA Astrophysics Data System (ADS)

    Lin, David Yuh-Shyang

    This thesis presents the morphology and orientation development of electrospun fibers from polymer solutions with volatile solvents. Polymer solution concentration had a strong effect on the morphology of both Nylon 6,6 and poly(lactic acid) (PLLA) fibers. Successful electrospinning occurred above the overlap concentration, c* (˜0.1 wt% for Nylon 6,6 and 0.13 to 0.16 wt% for PLLA). Beaded fiber to smooth fiber transitions (5.4 to 8.3 wt% for Nylon 6,6 and 3.0 wt% for PLLA) were observed around the entanglement concentrations, ce, corresponding to entanglement characteristic values, [eta]C, of 5.4 to 8.5 (Nylon 6,6) and 20 to 24 (PLLA). Processing parameters, including DC voltage (VD), AC voltage (VA), frequency of VA, and tip-to-target distance, did not significantly affect the morphology of electrospun Nylon 6,6 fibers, but increasing VA or frequency resulted in more uniform fibers. Fully-aligned, defect-free PLLA scaffolds with diameters between 200 and 800 nm were electrospun by decreasing the solution feed rate, increasing the voltage and tip-to-target distance, and using concentrations near the beaded to smooth fiber transition. Neurites from dorsal root ganglion (DRG) explants that were seeded on these scaffolds were shown to follow the direction of these fibers upon contact. After 12 days, these neurites still adhered to the fibers and extended ˜1.5 to 2 cm from their original contact position. Neuroblastoma (SH-EP and SH-SY5Y) and Schwann cells were found to elongate and align parallel to the direction of the fibers. Orientation of electrospun fibers was found to be a function of fiber diameters. Polarized light optical microscopy was used to characterize banded structures in electrospun poly(hexyl isocyanate) (PHIC) fibers. The orientational order observed in fibers with diameters between 2 mum and 13 mum increased linearly with decreasing diameters. The structure of electrospun PLLA fibers was determined to be the beta structure. Using the intensity

  10. Goethe's bone and the beginnings of morphology.

    PubMed

    Opitz, John M

    2004-04-01

    Biology as a discipline per se and its agenda, seems not to have been burdened from its beginnings as heavily with neo-Platonism as its subspecialty morphology, conceptualized at the same time by Goethe and Burdach. One of the reasons may have been that biologists were then regarded as "mere" naturalists, "doing" anatomy and embryology, breeding, and field work (as did Darwin, Wallace, Bateson and a legion of others during the 19th century), whereas the, perhaps more elitist, morphologists, ab initio devoted themselves to the origin, even to the Kantian analysis of causes of development and its variability within and between species. Since Goethe included abnormal plant development in his studies, his definition of morphology as the science of the form, formation and transformation of living organisms may be modified to include the concept of malformation, although the embryological and comparative analysis of vertebrate/mammalian malformation had its real inception somewhat later with the younger Meckel. In view of the meaning attached by his French contemporaries to the term transformisme (eventually defined as evolution) one would err considering Goethe as a prophet of "descent;" he was not, referring primarily to the continuous state of flux of living beings. Nonetheless, Goethe and Burdach independently coined the concept of morphology and set its agenda, increasingly freed of Naturphilosophie, an agenda that dominated 19th century biology but which did not come to fruition in its causal analysis of form and its formation until the 20th century, after Mendel, Darwin and the pioneers of experimental embryology (a.o., Roux, Driesch, Spemann, Vogt). In his discovery of the intermaxillary bone in humans (Goethe's bone), he had a startling insight, against conventional wisdom, into the anatomical, hence developmental, similarity of primate/mammals. During his lifetime, this was still called analogie by his great French contemporary Etienne Geoffroy St-Hilaire who

  11. Morphological Evolution of Block Copolymer Particles: Effect of Solvent Evaporation Rate on Particle Shape and Morphology.

    PubMed

    Shin, Jae Man; Kim, YongJoo; Yun, Hongseok; Yi, Gi-Ra; Kim, Bumjoon J

    2017-02-28

    Shape and morphology of polymeric particles are of great importance in controlling their optical properties or self-assembly into unusual superstructures. Confinement of block copolymers (BCPs) in evaporative emulsions affords particles with diverse structures, including prolate ellipsoids, onion-like spheres, oblate ellipsoids, and others. Herein, we report that the evaporation rate of solvent from emulsions encapsulating symmetric polystyrene-b-polybutadiene (PS-b-PB) determines the shape and internal nanostructure of micron-sized BCP particles. A distinct morphological transition from the ellipsoids with striped lamellae to the onion-like spheres was observed with decreasing evaporation rate. Experiments and dissipative particle dynamics (DPD) simulations showed that the evaporation rate affected the organization of BCPs at the particle surface, which determined the final shape and internal nanostructure of the particles. Differences in the solvent diffusion rates in PS and PB at rapid evaporation rates induced alignment of both domains perpendicular to the particle surface, resulting in ellipsoids with axial lamellar stripes. Slower evaporation rates provided sufficient time for BCP organization into onion-like structures with PB as the outermost layer, owing to the preferential interaction of PB with the surroundings. BCP molecular weight was found to influence the critical evaporation rate corresponding to the morphological transition from ellipsoid to onion-like particles, as well as the ellipsoid aspect ratio. DPD simulations produced morphologies similar to those obtained from experiments and thus elucidated the mechanism and driving forces responsible for the evaporation-induced assembly of BCPs into particles with well-defined shapes and morphologies.

  12. Discord between morphological and phylogenetic species boundaries: incomplete lineage sorting and recombination results in fuzzy species boundaries in an asexual fungal pathogen

    PubMed Central

    2014-01-01

    new areas, and for regulating the movement of pathogens to enforce quarantines. This research shows that multilocus phylogenetic methods that allow for recombination and incomplete lineage sorting can be useful for the quantitative delimitation of asexual species that are morphologically indistinguishable. Two phylogenetic species of Alternaria were identified as causing citrus brown spot worldwide. Further research is needed to determine how these species were introduced worldwide, how they differ phenotypically and how these species are maintained. PMID:24593138

  13. Morphology of arolia in Auchenorrhyncha (Insecta, Hemiptera).

    PubMed

    Friedemann, Katrin; Beutel, Rolf G

    2014-11-01

    The pretarsal arolium serves as an attachment device in many groups of insects, enabling them to walk efficiently on smooth surfaces, where claws alone do not provide sufficient foothold. The arolia of representatives of all major lineages of Auchenorrhyncha are described and illustrated, mainly using scanning electron microscopy and histology. Glands inside the lumen of the arolia are described for the first time in this group. It is shown that the morphology of arolia within Auchenorrhyncha differs considerably. Some of them are even distinctly bilobed. The cuticle of the contact zone is thickened and formed of branching chitinous rods. In some cases, two layers of rods oriented in different directions were found. An extended definition of "arolium" is proposed.

  14. Morphological effect on swelling behaviour of hydrogel

    SciTech Connect

    Yacob, Norzita; Hashim, Kamaruddin

    2014-02-12

    Hydrogels are hydrophilic polymer networks that are capable of imbibing large amounts of water. In this work, hydrogels prepared from natural and synthetic polymers were irradiated by using electron beam irradiation. The morphology of hydrogel inter-polymeric network (IPN) was investigated using Scanning Electron Microscopy (SEM). The studies reveal correlations between pore sizes of IPN with degree of cross-linking. This relation also has an effect on swelling properties of the hydrogel. The results indicated that hydrogel with smaller pore size, as a result of much dense IPN, would decrease water uptake capacity. Combination of natural and synthetic polymers to form hydrogel affects the pore size and swelling property of the hydrogel as compared to each component of polymer.

  15. Small Martian valleys - Pristine and degraded morphology

    NASA Technical Reports Server (NTRS)

    Baker, V. R.; Partridge, J. B.

    1986-01-01

    This study is concerned with a more detailed investigation of the small valley networks on Mars. The dual nature of many valley systems is pointed out, taking into account a relatively fresh-appearing network portion versus an apparent larger, less distinct network system. These separate network characteristics are referred to as pristine and degraded. The valley networks included in this study are all located in the equatorial zone of heavily cratered uplands, between latitudes 30 deg N and 40 deg S. Aspects of network morphology are examined, taking into account drainage density, network dissection ratio, and valley length parameters. Age relationships are also discussed, giving attention to crater age, counting problems, a conservative method, and a crater-fraction method.

  16. Ultraviolet Halos around Spiral Galaxies. I. Morphology

    NASA Astrophysics Data System (ADS)

    Hodges-Kluck, Edmund; Cafmeyer, Julian; Bregman, Joel N.

    2016-12-01

    We examine ultraviolet halos around a sample of highly inclined galaxies within 25 Mpc to measure their morphology and luminosity. Despite contamination from galactic light scattered into the wings of the point-spread function, we find that ultraviolet (UV) halos occur around each galaxy in our sample. Around most galaxies the halos form a thick, diffuse disk-like structure, but starburst galaxies with galactic superwinds have qualitatively different halos that are more extensive and have filamentary structure. The spatial coincidence of the UV halos above star-forming regions, the lack of consistent association with outflows or extraplanar ionized gas, and the strong correlation between the halo and galaxy UV luminosity suggest that the UV light is an extragalactic reflection nebula. UV halos may thus represent 106-107 M ⊙ of dust within 2-10 kpc of the disk, whose properties may change with height in starburst galaxies.

  17. Morphologies at High Redshift from Galaxy Zoo

    NASA Astrophysics Data System (ADS)

    Masters, Karen; Melvin, Tom; Simmons, Brooke; Willett, Kyle; Lintott, Chris

    2015-08-01

    I will present results from Galaxy Zoo classification of galaxies observed in public observed frame optical HST surveys (e.g. COSMOS, GOODS) as well as in observed frame NIR with (ie. CANDELS). Early science results from these classifications have investigated the changing bar fraction in disc galaxies as a function of redshift (to z~1 in Melvin et al. 2014; and at z>1 in Simmons et al. 2015), as well as how the morphologies of galaxies on the red sequence have been changing since z~1 (Melvin et al. in prep.). These unique dataset of quantitative visual classifications for high redshift galaxies will be made public in forthcoming publications (planned as Willett et al. for Galaxy Zoo Hubble, and Simmons et al. for Galaxy Zoo CANDELS).

  18. Soft micromachines with programmable motility and morphology.

    PubMed

    Huang, Hen-Wei; Sakar, Mahmut Selman; Petruska, Andrew J; Pané, Salvador; Nelson, Bradley J

    2016-07-22

    Nature provides a wide range of inspiration for building mobile micromachines that can navigate through confined heterogenous environments and perform minimally invasive environmental and biomedical operations. For example, microstructures fabricated in the form of bacterial or eukaryotic flagella can act as artificial microswimmers. Due to limitations in their design and material properties, these simple micromachines lack multifunctionality, effective addressability and manoeuvrability in complex environments. Here we develop an origami-inspired rapid prototyping process for building self-folding, magnetically powered micromachines with complex body plans, reconfigurable shape and controllable motility. Selective reprogramming of the mechanical design and magnetic anisotropy of body parts dynamically modulates the swimming characteristics of the micromachines. We find that tail and body morphologies together determine swimming efficiency and, unlike for rigid swimmers, the choice of magnetic field can subtly change the motility of soft microswimmers.

  19. Soft micromachines with programmable motility and morphology

    NASA Astrophysics Data System (ADS)

    Huang, Hen-Wei; Sakar, Mahmut Selman; Petruska, Andrew J.; Pané, Salvador; Nelson, Bradley J.

    2016-07-01

    Nature provides a wide range of inspiration for building mobile micromachines that can navigate through confined heterogenous environments and perform minimally invasive environmental and biomedical operations. For example, microstructures fabricated in the form of bacterial or eukaryotic flagella can act as artificial microswimmers. Due to limitations in their design and material properties, these simple micromachines lack multifunctionality, effective addressability and manoeuvrability in complex environments. Here we develop an origami-inspired rapid prototyping process for building self-folding, magnetically powered micromachines with complex body plans, reconfigurable shape and controllable motility. Selective reprogramming of the mechanical design and magnetic anisotropy of body parts dynamically modulates the swimming characteristics of the micromachines. We find that tail and body morphologies together determine swimming efficiency and, unlike for rigid swimmers, the choice of magnetic field can subtly change the motility of soft microswimmers.

  20. Clinical Insights Into Foveal Morphology in Albinism

    PubMed Central

    McCafferty, Brandon K.; Wilk, Melissa A.; McAllister, John T.; Stepien, Kimberly E.; Dubis, Adam M.; Brilliant, Murray H.; Anderson, Jennifer L; Carroll, Joseph; Summers, C. Gail

    2016-01-01

    Purpose A hallmark of albinism is foveal hypoplasia. However, literature suggests variable foveal development. This study evaluates the association between ocular phenotype and foveal morphology to demonstrate the broad structural and functional spectrum. Methods Best-corrected visual acuity (BCVA), nystagmus, angle kappa, stereoacuity, iris transillumination, macular melanin presence, foveal avascular zone, and annular reflex were recorded in 14 patients with albinism. Spectral-domain optical coherence tomography provided macular images. Results The clinical phenotype was broad, with BCVA varying from 20/20 to 20/100. Better BCVA was associated with a preserved foveal avascular zone, annular macular reflex, stereoacuity, and macular melanin. Imaging demonstrated a continuum of foveal development correlating with BCVA. Individuals with a rudimentary pit had normal inner and outer segment lengthening and better BCVA. Conclusions The spectrum of ocular structure and visual function in albinism is broad, suggesting a possible diagnosis of albinism in a patient with an even more normal clinical presentation. PMID:26053207

  1. [Chromatin morphology and cytokinesis in pleurocapsalean cyanobacteria].

    PubMed

    Pinevich, A V; Gavrilova, O V; Averina, S G

    2007-01-01

    By means of differential interference contrast (DIC) and fluorescence microscopy, chromatin morphology and cytokinesis have been described in the cyanobacterium Pleurocapsa sp. CALU 1126 capable of multiple fission (multiple reproduction of the mother cell, the macrocyte, with formation of unique reproductive cells, the baeocytes). Two kinds of chromatin behavior have been revealed in the cell cycle: 1) the formation of numerous chromatin areas before their compartmentalization by multiple fission; 2) chromatin condensation in the phase of binary fission, and chromatin decondensation in growth period. The cytokinetic essence of multiple fission has been shown to consist of successive binary fissions of the macrocyte, while in between the mother cells (pre-baeocytes) do not grow.

  2. On culture artefacts in coccolith morphology

    NASA Astrophysics Data System (ADS)

    Langer, Gerald; Oetjen, Kerstin; Brenneis, Tina

    2013-06-01

    Coccolith malformations occur more frequently in cultured specimens than in specimens from natural samples, a phenomenon commonly termed `culture artefacts'. The causes of culture artefacts are unknown. Here, we tested the effect of culture flask shape, mixing, and cell density on the morphology of Emiliania huxleyi coccoliths. While there was no effect of different culture flask types typically used in coccolithophore culturing, continuous mixing reduced the percentage of malformations by ca. 11 % in exponential-phase cells (cell density ca. 80 × 103 cells per ml) and ca. 17 % in stationary-phase cells (cell density ca. 2 × 106 cells per ml). Stationary-phase cells displayed 19 % more malformations than mid-exponential-phase cells when not mixed at all and 20 % more malformations when continuously mixed. It is concluded that the lack of mixing and unnaturally high cell densities, typical for coccolithophore stock cultures, are partly responsible for culture artefacts.

  3. Fluctuations of thermal conductivity and morphological stability

    NASA Technical Reports Server (NTRS)

    Mazuruk, K.; Gillies, D. C.; Lehoczky, S. L.

    1995-01-01

    Compositional fluctuations of the binary alloy result in the corresponding fluctuations of the thermal conductivity of the material. During crystal growth, these fluctuations can significantly modify the local temperature fields at the liquid-solid interface. This, in turn, will affect the morphological stability of the growing interface. In this work, the temperature dependence of the thermal conductivity of the solid phase has been included into the Mullins-Sekerka formalism. A significant effect on the onset of the instability of planar interface has been predicted. It has been found, in particular, that for binary systems with the segregation coefficient above unity a flat interface is always unstable. The shape of the interface fluctuation should have a single harmonic character with a well defined wavelength.

  4. Arborescent palm seed morphology and seedling distribution.

    PubMed

    Salm, Rodolfo

    2005-11-01

    This study examines how the seed morphology of two large arborescent palms, Attalea maripa (Aubl.) Mart. and Astrocaryum aculeatum G. Mey, may affect their seed shadow in a seasonally dry Amazonian forest. In addition to being smaller and produced in larger numbers than those of A. aculeatum, A. maripa seeds also presented a substantially lower amount of nutritional reserves available for the embryo. However, A. maripa seedlings were found in much higher numbers than those of A. aculeatum. The results suggest that, within the spatial scale considered, the seed rain of A. maripa is more restricted to the area surrounding around reproductive conspecifics than that of A. aculeatum. Furthermore, in comparison with those of A. aculeatum, the smaller seeds of A. maripa might be less attractive to scatterhoarding rodents (e.g. Dasyprocta aguti). The pattern observed emphasizes the importance of scatterhoarding rodents as dispersers of large-seeded plant species in Neotropical forests.

  5. Morphology and Melting Behavior of Polypropylenes

    NASA Astrophysics Data System (ADS)

    Alamo, R. G.; Mandelkern, L.

    1997-03-01

    The double melting of isothermally crystallized polypropylenes (metallocenes or Ziegler fractions) of a low defect content, is found to be associated with the presence of dominant (usually thicker) and daughter lamellae. A double population of lamellae thicknesses that adheres to the formulated epitaxial crystallization is seen by TEM even in samples crystallized at temperatures above 160 degC. Mixed and positive spherulites are also observed to grow linearly at these temperatures. During the melting process, positive or mixed spherulites show a well defined change to a negative character at a temperature corresponding to the low temperature endotherm in agreement with the melting of the daughter lamellae at this temperature. It is also found that the melting and stability of the dominant lamellae are influenced by the presence of epitaxial transversal lamellae. The kinetics of the melting process are investigated in relation to the initial morphology. Higher defected polypropylenes with a high concentration of gamma crystals do not show associated melting kinetics.

  6. Matching behavioral evolution to brain morphology.

    PubMed

    Legendre, P; Lapointe, F J

    1995-01-01

    A method is presented to test the relationship between a phylogenetic tree derived from brain morphology, and different hypotheses describing the evolution of a behavioral trait. This is a question of interest for evolutionary psychologists and behavioral biologists. The paper first discusses how hypotheses for behavioral evolution should be coded for such a comparison, then a triple-per-mutation test, originally proposed to compare independently obtained evolutionary trees, is used for the statistical assessment of each hypothesis. Non-parametric correlation coefficients computed between brain components and appropriately coded behavioral states can then be used to suggest what brain components are responsible for the development of the various states of the behavioral trait of interest. The procedure is illustrated with three different applications relating brain evolution to habitat selection in marsupials, locomotory specialization in primates, and trophic adaptation in bats.

  7. Mars: Morphology of Southern Hemisphere intracrater dunefields

    NASA Technical Reports Server (NTRS)

    Lancaster, N.; Greeley, R.

    1987-01-01

    Viking Orbiter images of intracrater dunefields in the Noachis Terra region were examined in order to study the morphology of these landforms and to assess their relationship to local geological settings. The sizes of the dunefields range from 40 to 3600 sq km and vary directly with crater size. Preliminary studies reveal dunefields of two varieties. The most common type is composed of massed straight to slightly wavy crescentic dunes similar to those described by Breed. Dunefields of this type occupy more than 20% of the area of the crater floor, with the dunefield margins often marked by a large dune wall or rampart. Dune spacing ranges between 0.7 and 1.2 km. The second type of dune accumulation consists of clusters of large, widely spaced straight or curved ridges, which often intersect to create rectilinear patterns. Dunes are typically spaced 1.6 to 4 km apart. Earth terrestrial analogs for these dunes are discussed.

  8. Nornahraun lava morphology and mode of emplacement

    NASA Astrophysics Data System (ADS)

    Pedersen, Gro B. M.; Höskuldsson, Armann; Riishuus, Morten S.; Jónsdóttir, Ingibjörg; Gudmundsson, Magnús T.; Sigmundsson, Freysteinn; Óskarsson, Birgir V.; Drouin, Vincent; Gallagher, Catherine; Askew, Rob; Moreland, William M.; Dürig, Tobias; Dumont, Stephanie; Þórdarson, Þór

    2015-04-01

    The ongoing Nornahraun eruption is the largest effusive eruption in Iceland since the Laki eruption in 1783-84, with an estimated lava volume of ~1.15 km3 covering an area of ~83.4 km2 (as of 5 JAN 2015). The eruption provides an unprecedented opportunity to study i) lava morphologies and their emplacement styles, ii) the transition from from open to closed lava pathways and iii) lava pond formation. Tracking of the lava advancement and morphology has been performed by GPS and GoPro cameras installed in 4×4 vehicles as well as video footage. Complimentary observations have been provided from aircraft platforms and by satellite data. Of particular importance for lava morphology observations are 1-12 m/pixel airborne SAR images (x-band). The Nornahraun flow field comprises a continuum of morphologies from pāhoehoe to 'a'ā, which have varied tem-porally and spatially. At the onset of the eruption 31 AUG, lava flows advanced rapidly (400-800 m/hr) from the 1.5 km long fissure as large slabby pāhoehoe [1-3] sheet lobes, 100-500 m wide and 0.3-1 m thick at the flow fronts. By 1 SEPT, the flows began channeling towards the NE constrained by the older Holuhraun I lava field and the to-pography of flood plain itself. A central open channel developed, feeding a 1-2 km wide active 'a'ā frontal lobe that advanced 1-2 km/day. In addition to its own caterpillar motion, the frontal lobe advanced in a series of 30-50 m long breakouts, predominantly slabby and rubbly pāhoehoe [4,5]. These breakouts had initial velocities of 10-30 m/hr and reached their full length within tens of minutes and subsequently inflated over hours. With the continuous advancement of the 'a'ā flow front, the breakouts were incorporated into the 'a'ā flow fronts and seldom preserved. At the margins of the frontal lava lobe, the breakouts were more sporadic, but predominantly rubbly pāhoehoe and slabby pāhoehoe, as at the flow front. The lava flow advanced ENE into Jökulsá á Fjöllum on 7 SEPT

  9. Polymer Morphological Change Induced by Terahertz Irradiation.

    PubMed

    Hoshina, Hiromichi; Suzuki, Hal; Otani, Chiko; Nagai, Masaya; Kawase, Keigo; Irizawa, Akinori; Isoyama, Goro

    2016-06-07

    As terahertz (THz) frequencies correspond to those of the intermolecular vibrational modes in a polymer, intense THz wave irradiation affects the macromolecular polymorph, which determines the polymer properties and functions. THz photon energy is quite low compared to the covalent bond energy; therefore, conformational changes can be induced "softly," without damaging the chemical structures. Here, we irradiate a poly(3-hydroxybutylate) (PHB) / chloroform solution during solvent casting crystallization using a THz wave generated by a free electron laser (FEL). Morphological observation shows the formation of micrometer-sized crystals in response to the THz wave irradiation. Further, a 10-20% increase in crystallinity is observed through analysis of the infrared (IR) absorption spectra. The peak power density of the irradiating THz wave is 40 MW/cm(2), which is significantly lower than the typical laser intensities used for material manipulation. We demonstrate for the first time that the THz wave effectively induces the intermolecular rearrangement of polymer macromolecules.

  10. [Geometrical motives in the Tetraodontiformes fishes morphology].

    PubMed

    Voĭtekhovskiĭ, Iu L

    2009-01-01

    Analysis of features of the Ostraciontidae (boxfishes) and Diodontidae (porcupinefishes) families revealed their morphological dualism, also known in combinatorial geometry and crystallography as the dualism of the Dirichlet tiling and that of Delaunay. If we take bases of spines on the body of Diodontidae for the Delaunay points (R, r)-system, the respective Dirichlet tiling will reveal the surface of an Ostraciontidae species being divided into polygonal osseous blades. This fact corroborates taxonomic relationship of the Ostraciontidae and Diodontidae families within the Tetraodontiformes order and indicates the principles of purposefulness in nature, which manifest both in mineral and biological structures. In the course of the present research four specimens of Diodon holocanthus (Diodontidae) were studied and characteristics of the Dirichlet tiling for the surfaces of their bodies were determined.

  11. Pathogenicity, morphology, and differentiation of Acanthamoeba.

    PubMed

    Khan, N A

    2001-12-01

    Acanthamoeba keratitis is sight threatening corneal infection caused by pathogenic Acanthamoeba. Previous studies have shown the genotypic differences between pathogenic and non-pathogenic species/strains of Acanthamoeba. In this study, we examined the morphological differences between pathogenic and non-pathogenic species/strains using scanning electron microscopy. Pathogenic Acanthamoeba exhibited higher number of acanthopodia (structures associated with the binding of amoeba to the target cells) as compared to non-pathogens. In addition, interactions of amoeba with the corneal epithelial cells were studied. Only pathogenic amoeba exhibited adhesion to epithelial cells. Further results indicated that phagocytosis occurs in the pathogenic amoeba by the formation of amoebastome (characteristic of amoeba phagocyte). This study showed that Acanthamoeba phagocytosis may be both an efficient means of obtaining nutrients for the amoeba and a significant factor in the pathogenesis of Acanthamoeba infections.

  12. [Morphology of the gastroesophageal reflux disease].

    PubMed

    Daum, Ondřej; Kokošková, Bohuslava; Švajdler, Marian

    2016-01-01

    The present definition of gastroesophageal reflux disease is based on clinical criteria that are difficult to reproduce accurately. Pathologists are supposed to confirm the presence of morphological changes induced by gastroesophageal reflux. Traditional evaluation of injury, inflammatory and reactive changes of esophageal squamous epithelium lacks both sufficient sensitivity and specificity, and thus the modern diagnostic focuses on chronic metaplastic changes of esophageal mucosa defined as any mucosal type proximal to the upper border of oxyntic mucosa (also called fundic mucosa of the stomach). In the setting of gastroesophageal reflux the esophageal mucosa, under normal conditions lined with squamous epithelium, undergoes columnar metaplasia. According to morphology and immunophenotype of columnar cells, the columnar metaplasia may be further subdivided to oxyntocardiac mucosa, cardiac mucosa, intestinal metaplasia, and an intermediate type of cardiac mucosa expressing intestinal transcription factor CDX2, but devoid of goblet cells. The latter two mucosal types are currently thought to represent the most probable candidates for neoplastic transformation, whereas oxyntocardiac mucosa is believed to represent a stable compensatory change with no risk of further progression. An evaluation of dysplastic changes (intraepithelial neoplasia) in the setting of columnar lined esophagus necessitates correlation with the second opinion of a GI expert to prevent potentially harmful under- or over-treatment of the patient. Regarding invasive adenocarcinoma, the pathologist should avoid overdiagnosis of the infiltration of the space between the two layers of columnar lined esophagus - associated split muscularis mucosae as invasion of submucosa, as it is associated with different prognosis. Critical evaluation of the real impact of acid suppression on neoplastic transformation in the setting of gastroesophageal reflux disease may represent the greatest challenge for future

  13. Robot Guidance Using A Morphological Vision Algorithm

    NASA Astrophysics Data System (ADS)

    Lougheed, Robert M.; Tomko, Leonard M.

    1985-12-01

    An algorithm has been developed to guide a robot by identifying the orientation of a randomly-acquired part held in the robot's gripper. A program implementing this algorithm is being used to demonstrate the feasibility of part-independent robotic bin picking*. The project task was to extract unmodified industrial parts from a compartmentalized tray and position them on a fixture. The parts are singulated in the compartments but are positionally and rotationally unconstrained. The part is acquired based upon three-dimensional image data which is processed by a 3D morphological algorithm described in [1]. The vision algorithm discussed here inspects the parts, determines their orientation and calculates the robot trajectory to a keyed housing with which the part must be mated. When parts are extracted during a bin picking operation their position and orientation are affected by many factors, such as gripper insertion-induced motion, interference with container side walls during extraction, slippage due to gravity and vibration during robot motions. The loss of the known position and orientation of the part in the robot gripper makes accurate fixturing impossible. Our solution to this problem was to redetermine the orientation of the part after acquisition. This paper describes the application in detail and discusses the problems encountered in robot acquisition of unconstrained parts. Next, the physical setup and image acquisition system, including lighting and optical components, are discussed. The principles of morphological (shape-based) image processing are presented, followed by a description of the interactive algorithm development process which was used for this project. The algorithm is illustrated step by step with a series of diagrams showing the effects of the transformations applied to the data. The algorithms were run on ERIM' s new fourth generation hybrid image processing architecture, the Cyto-HSS, which is described in detail in [2], and the

  14. Kimberlite emplacement record in diamond morphology

    NASA Astrophysics Data System (ADS)

    Fedortchouk, Y.; Chinn, I.

    2015-12-01

    Diamond resorption morphology reflects conditions and events in the host kimberlite magma and in diamond sources in subcratonic mantle. Recent experimental studies on diamond dissolution enable us now to use surface features of diamonds to examine magmatic fluid in kimberlites. This study uses optical and scanning electron microscopy examination of ~750 macro-diamonds from two kimberlites in Orapa cluster, Botswana. Kimberlite A is a simple body filled with coherent kimberlite facies (CK); kimberlite B is a complex body with two facies of coherent kimberlite and a massive volcaniclastic kimberlite facies (MVK). Distinction between kimberlite-induced and mantle-derived resorption was based on: the type of the most abundant resorption style, morphology of crystals with attached kimberlite fragments, and the study of pseudohemimorphic diamonds. Kimberlite-induced resorption is the focus of this work. The three facies in the pipe B show three contrasting diamond resorption types. Resorption in MVK facies leads to glossy rounded surfaces with fine striation and hillocks, and is identical to the resorption style in CK facies of pipe A. This type of resorption is typical for volcaniclastic facies and indicates emplacement in the presence of abundant COH fluid with high H2O:CO2 ratio (>50mol% of H2O). We propose that pipe A is a root zone supplying material to a larger kimberlite body filled with VK. The two CK in pipe B have very different resorption style. One forms similar glossy surfaces but with regular small cavities of rounded outline, while the other seems more corrosive and develops extremely rough features and deep cavities. Comparison to the experimental data suggests that the former had almost pure H2O fluid at low pressure (where solubility of SiO2 is low). The later CK facies was emplaced in the absence or very low abundance of a free fluid, and possibly in melt closer to carbonatitic composition.

  15. CRISPRi engineering E. coli for morphology diversification.

    PubMed

    Elhadi, Dina; Lv, Li; Jiang, Xiao-Ran; Wu, Hong; Chen, Guo-Qiang

    2016-11-01

    Microbial morphology engineering has recently become interesting for biotechnology. Genes ftsZ and mreB encoding proteins of bacterial fission ring and skeletons, respectively, are essential for cell growth, they both are the most important genes keeping the bacterial shapes including the cell length and width, respectively. Clustered regularly interspaced short palindromic repeats interference, abbreviated as CRISPRi, was for the first time used in this study to regulate expression intensities of ftsZ or/and mreB in E. coli. Five sgRNAs associated with CRISPRi were designed and synthesized, respectively, to target five various locations on genes ftsZ or mreB encoded in the E. coli chromosome, resulting in various reduced expression levels of ftsZ or/and mreB, respectively, forming elongated or/and fatter cells. Repressions on gene expressions of ftsZ or/and mreB could be further intensified by combining various sgRNAs together. It was found that the stronger the repression on genes ftsZ or/and mreB, the longer the E. coli fibers, and the larger the E. coli cells. Combined repressions on expressions of ftsZ and mreB generated long and larger E. coli with diverse morphologies including various sizes of gourds, bars, coccus, spindles, multi-angles and ellipsoids. In all cases, accumulations of intracellular biopolyester polyhydroxybutyrate (PHB) were in direct proportional to the intracellular volumes, ranging from 40% to 80% PHB in bacterial cell dry weights, depending on the cell volumes increases by the above CRISPRi applications.

  16. Landscape Morphology of the Canadian Rocky Mountains

    NASA Astrophysics Data System (ADS)

    Quinlan, K. T.; Barnes, J. B.; Pavelsky, T.

    2013-12-01

    Glaciers and rivers can significantly modify the shape of mountain landscapes. Following deformation and glaciation, bedrock river form and incision patterns are primarily controlled by variations in geologic structure, the glacial preconditioning of the landscape, and climate. However, the extent to which these factors integrate to affect Holocene patterns and rates of fluvial processes is poorly understood. Fluvial processes dominate the morphology of the Canadian Rocky Mountains today, though the inherited imprint of glaciers remains substantial. This study of fluvial geomorphology in the Athabasca River watershed in Jasper National Park, Alberta, addresses two primary ideas: (1) the fluvial response to deglaciation in alpine environments, and (2) the role of thrust belt geology affecting differential erosion in shaping post-orogenic topography. We use the 0.75 arc-second GeoBase Digital Elevation Model (~18m resolution) to analyze patterns of river concavity (θ) and normalized steepness index (ksn), estimate rock erodibility with field-based proxy measurements, and determine basin-averaged erosion rates using existing river gauge data. We find that bedrock geology and glacial preconditioning exhibit different yet recognizable morphological signatures and that they appear to be related to basin erosion rate. The principal differences we observe include the shape and scale of knickzones, magnitude of channel steepness values, channel concavity patterns, and relationship to bedrock geology. We find that lithologically controlled channel steepness patterns are contained to local spatial scales (<500m) and feature sharp increases in channel steepness at or near contacts between lithologies with differences in measured erodibility. By contrast, glacially controlled steepness patterns are expansive in spatial extent (1-10km), are insensitive to bedrock geology, and have higher overall channel steepness values than areas of lithologically controlled channel steepness

  17. Morphology of lacrimal gland in pig fetuses.

    PubMed

    Klećkowska-Nawrot, J; Dziegiel, P

    2008-02-01

    The morphological and histological examinations of the lacrimal gland were conducted on pig fetuses coming from the 20th, 24th, 27th, 30th, 35th, 50th, 63rd, 94th and 112th day of gestation. The morphological examinations were carried out using the method of macroscopic preparation with a forehead magnifying glass and binocular (magnification 1.5-5.0x). In order to better visualize the anatomical elements, 60-80% absolute alcohol and 0.5-4% acetic acid solution were used for the examinations. On the 20th, 24th, 27th, and 30th day of gestation the whole fetuses were collected for the histological examinations. The whole eyeball with developing accessory organs was collected from the pig fetuses on the 35th day of gestation. On the 50th, 63rd, 94th and 112th day of gestation only the lacrimal gland was collected. Staining with H-E and Azan method was performed. On the 20th, 24th, 27th, 30th and 35th day of gestation ectodermal cells were not found in the collected material. On the 50th and 63rd day of gestation the connective tissue divides the gland parenchyma into indistinct lobes composed of gland cells. On the 94th day of gestation the number of lobes is substantially higher than on the 50th and 63rd day of gestation, while the number of lobules forming lobes decreases. On the 112th day of gestation each lobe is composed of 8-22 excretory ducts made up of the simple cuboid epithelium with a round nucleus arranged less or more peripherally.

  18. Semantic processing during morphological priming: an ERP study.

    PubMed

    Beyersmann, Elisabeth; Iakimova, Galina; Ziegler, Johannes C; Colé, Pascale

    2014-09-04

    Previous research has yielded conflicting results regarding the onset of semantic processing during morphological priming. The present study was designed to further explore the time-course of morphological processing using event-related potentials (ERPs). We conducted a primed lexical decision study comparing a morphological (LAVAGE - laver [washing - wash]), a semantic (LINGE - laver [laundry - wash]), an orthographic (LAVANDE - laver [lavender - wash]), and an unrelated control condition (HOSPICE - laver [nursing home - wash]), using the same targets across the four priming conditions. The behavioral data showed significant effects of morphological and semantic priming, with the magnitude of morphological priming being significantly larger than the magnitude of semantic priming. The ERP data revealed significant morphological but no semantic priming at 100-250 ms. Furthermore, a reduction of the N400 amplitude in the morphological condition compared to the semantic and orthographic condition demonstrates that the morphological priming effect was not entirely due to the semantic or orthographic overlap between the prime and the target. The present data reflect an early process of semantically blind morphological decomposition, and a later process of morpho-semantic decomposition, which we discuss in the context of recent morphological processing theories.

  19. Morphology development of layered silicate epoxy based nanocomposites

    NASA Astrophysics Data System (ADS)

    Benson Tolle, Tia

    2005-07-01

    Nanotailoring of polymeric materials offers significant benefits in terms of new and improved properties or new property trade spaces. Significant improvements to thermoplastics have been demonstrated over the past decade stimulated by the pioneering work of Kojima, Usuki, and Okada. The ability to nanotailor epoxy-based composites could have significant payoffs to aerospace and non-aerospace applications. However the dynamic nature of a crosslinking system such as epoxies poses unique challenges to the development of controlled morphologies. Before ultimate control of morphology and material design towards property enhancements can occur, fundamental understanding of how morphologies of various scales develop with processing parameters must be developed. This dissertation summarizes the effects of various processing variables on the development of morphology within organically modified layered silicate-epoxy-amine materials. The effect of various morphologies on fracture behavior is also examined, and suggests that ordered morphologies on the nanoscale can provide for effective toughening of epoxies.

  20. The three-dimensional morphology of growing dendrites

    SciTech Connect

    Gibbs, J. W.; Mohan, K. A.; Gulsoy, E. B.; Shahani, A. J.; Xiao, X.; Bouman, C. A.; De Graef, M.; Voorhees, P. W.

    2015-07-03

    The processes controlling the morphology of dendrites have been of great interest to a wide range of communities, since they are examples of an out-of-equilibrium pattern forming system, there is a clear connection with battery failure processes, and their morphology sets the properties of many metallic alloys. We determine the three-dimensional morphology of free growing metallic dendrites using a novel X-ray tomographic technique that improves the temporal resolution by more than an order of magnitude compared to conventional techniques. These measurements show that the growth morphology of metallic dendrites is surprisingly different from that seen in model systems, the morphology is not self-similar with distance back from the tip, and that this morphology can have an unexpectedly strong influence on solute segregation in castings. These experiments also provide benchmark data that can be used to validate simulations of free dendritic growth.

  1. The Three-Dimensional Morphology of Growing Dendrites

    PubMed Central

    Gibbs, J. W.; Mohan, K. A.; Gulsoy, E. B.; Shahani, A. J.; Xiao, X.; Bouman, C. A.; De Graef, M.; Voorhees, P. W.

    2015-01-01

    The processes controlling the morphology of dendrites have been of great interest to a wide range of communities, since they are examples of an out-of-equilibrium pattern forming system, there is a clear connection with battery failure processes, and their morphology sets the properties of many metallic alloys. We determine the three-dimensional morphology of free growing metallic dendrites using a novel X-ray tomographic technique that improves the temporal resolution by more than an order of magnitude compared to conventional techniques. These measurements show that the growth morphology of metallic dendrites is surprisingly different from that seen in model systems, the morphology is not self-similar with distance back from the tip, and that this morphology can have an unexpectedly strong influence on solute segregation in castings. These experiments also provide benchmark data that can be used to validate simulations of free dendritic growth. PMID:26139473

  2. Thermal effect on the morphology and performance of organic photovoltaics.

    PubMed

    Kawashima, Eisuke; Fujii, Mikiya; Yamashita, Koichi

    2016-09-29

    The morphology of organic photovoltaics (OPVs) is a significant factor in improving performance, and establishing a method for controlling morphology is necessary. In this study, we propose a device-size simulation model, combining reptation and the dynamic Monte Carlo (DMC) algorithm, to investigate the relationship between the manufacturing process, morphology, and OPV performance. The reptation reproduces morphologies under thermal annealing, and DMC showed morphology-dependence of performance: not only short-circuit current density but also open-circuit voltage had optimal interfacial areas due to competition between exciton dissociation and charge collection. Besides, we performed transient absorption spectroscopy of various BHJ morphologies under realistic conditions, which revealed prompt and delayed dynamics of charge generation-the majority of the charges were from excitons that were generated on interfaces and dissociated within a few picoseconds, and the others from excitons that migrated to interfaces and dissociated on the order of sub-nanoseconds.

  3. Morphological awareness assessment and intervention to improve language and literacy.

    PubMed

    Wolter, Julie A; Gibson, Frances E

    2015-02-01

    Morphological awareness positively influences language and literacy development and may be an ideal intervention focus for improving vocabulary, sight word reading, reading decoding, and reading comprehension in students with and without language and literacy deficits. This article will provide supporting theory, research, and strategies for implementing morphological awareness intervention with students with language and literacy deficits. Additionally, functional connections are explored through the incorporation and application of morphological awareness intervention in academic literacy contexts linked to Common Core State Standards.

  4. The role of morphology in reading and spelling.

    PubMed

    Sénéchal, Monique; Kearnan, Kyle

    2007-01-01

    The accumulated evidence that we reviewed suggests that children make use of regularities in the language--be it phonological, orthographic, and morphological--to read and spell words. Given that languages vary in the clarity with which oral language is represented in writing, one should expect the relative roles of phonological, orthographic, and morphological processing to vary accordingly. In this chapter, we focused on the relative contribution of morphological analysis and awareness to reading and spelling. We found that the morphological information in complex words can facilitate reading and spelling and that knowledge about the morphemic structure of a language can assist a child in reading, spelling, and deriving the meaning of multimorphemic words. The accumulated evidence also demonstrates that morphological awareness contributes to individual differences in reading and spelling that cannot be entirely subsumed to orthographic and phonological processing. Intervention studies on morphological knowledge (i.e., analysis and awareness), however, have not yielded the strong effects that one would have expected. We suspect that more successful intervention studies on how morphological knowledge can enhance literacy warrant a more thorough understanding of the complex interplay between morphological knowledge and a number of different variables such as oral vocabulary, phonological and orthographic awareness, and reading exposure. Given the demonstrated facilitative effects that morphological information can have on reading and spelling along with the particular difficulties that multimorphemic words can pose, researchers argue that systematic and sequential instruction of morphology is needed during the elementary years of schooling. Morphological rules, however, are currently not taught or taught partially to elementary school children. Perhaps, as Carlisle suggests, this is partly due to the fact that educators are more familiar with concepts of phonemes

  5. Varied morphology carbon nanotubes and method for their manufacture

    DOEpatents

    Li, Wenzhi; Wen, Jian Guo; Ren, Zhi Feng

    2007-01-02

    The present invention describes the preparation of carbon nanotubes of varied morphology, catalyst materials for their synthesis. The present invention also describes reactor apparatus and methods of optimizing and controlling process parameters for the manufacture carbon nanotubes with pre-determined morphologies in relatively high purity and in high yields. In particular, the present invention provides methods for the preparation of non-aligned carbon nanotubes with controllable morphologies, catalyst materials and methods for their manufacture.

  6. Association between trochlear morphology and chondromalacia patella: an MRI study.

    PubMed

    Duran, Semra; Cavusoglu, Mehtap; Kocadal, Onur; Sakman, Bulent

    This study aimed to compare trochlear morphology seen in magnetic resonance imaging between patients with chondromalacia patella and age-matched control patients without cartilage lesion. Trochlear morphology was evaluated using the lateral trochlear inclination, medial trochlear inclination, sulcus angle and trochlear angle on the axial magnetic resonance images. Consequently, an association between abnormal trochlear morphology and chondromalacia patella was identified in women. In particular, women with flattened lateral trochlea are at an increased risk of patellar cartilage structural damage.

  7. The Adopted Morphological Types of 247 Rich PF Galaxy Clusters

    NASA Astrophysics Data System (ADS)

    Panko, Elena; Bajan, Katarzyna; Flin, Piotr; Gotsulyak, Alla

    2016-10-01

    Morphological types were determined for 247 rich galaxy clusters from the PF Catalogue of Galaxy Clusters and Groups. The adopted types are based on classical morphological schemes and consider concentration to the cluster center, the signs of preferential direction or plane in the cluster, and the positions of the brightest galaxies. It is shown that both concentration and preferential plane are significant and independent morphological criteria.

  8. Extracting hurricane eye morphology from spaceborne SAR images using morphological analysis

    NASA Astrophysics Data System (ADS)

    Lee, Isabella K.; Shamsoddini, Ali; Li, Xiaofeng; Trinder, John C.; Li, Zeyu

    2016-07-01

    Hurricanes are among the most destructive global natural disasters. Thus recognizing and extracting their morphology is important for understanding their dynamics. Conventional optical sensors, due to cloud cover associated with hurricanes, cannot reveal the intense air-sea interaction occurring at the sea surface. In contrast, the unique capabilities of spaceborne synthetic aperture radar (SAR) data for cloud penetration, and its backscattering signal characteristics enable the extraction of the sea surface roughness. Therefore, SAR images enable the measurement of the size and shape of hurricane eyes, which reveal their evolution and strength. In this study, using six SAR hurricane images, we have developed a mathematical morphology method for automatically extracting the hurricane eyes from C-band SAR data. Skeleton pruning based on discrete skeleton evolution (DSE) was used to ensure global and local preservation of the hurricane eye shape. This distance weighted algorithm applied in a hierarchical structure for extraction of the edges of the hurricane eyes, can effectively avoid segmentation errors by reducing redundant skeletons attributed to speckle noise along the edges of the hurricane eye. As a consequence, the skeleton pruning has been accomplished without deficiencies in the key hurricane eye skeletons. A morphology-based analyses of the subsequent reconstructions of the hurricane eyes shows a high degree of agreement with the hurricane eye areas derived from reference data based on NOAA manual work.

  9. Morphologically complex protostellar envelopes : structure and kinematics

    NASA Astrophysics Data System (ADS)

    Tobin, John J.

    I present an in-depth study of protostars and their surrounding envelopes of dense gas and dust, using a multitude of observational methods to reveal new details of the star formation process. I use mid-infrared imaging from the Spitzer Space Telescope, combined with photometry spanning the near-infrared to millimeter wavelengths, to construct a model of the L1527 protostellar system. I modeled both the spectral energy distribution and resolved scattered light images to determine physical properties of the protostellar system. The nature of the apparent central point source in the Spitzer images was uncertain until high-resolution L-band imaging from the Gemini observatory resolved the point source into a disk in scattered light, having a radius of 200 AU. Protostellar envelopes are also often found to cast shadows against the 8 micron Galactic background in Spitzer imaging, enabling direct probes of envelope structure. The shadow images show that the dense envelopes around twenty-two Class 0 protostars are generally morphologically complex from 0.1 pc scales down to ˜1000 AU; they are often filamentary, and frequently non-axisymmetric. The observed envelope structure indicates a likely origin in turbulent cloud structure rather than a quasi-static/equilibrium formation. The complex envelope structure also may indicate an increased likelihood of fragmentation during collapse, forming close binaries. To further characterize these envelopes, I have observed them in the dense molecular gas tracers nthp and nht, both of which closely follow the 8 micron extinction morphology. The magnitude of the velocity gradients and envelope complexity on ˜10000 AU scales indicates that the velocity structure may reflect large-scale infall in addition to the often assumed rotation. Comparisons with three-dimensional filamentary and symmetric rotating collapse models reinforce the interpretation of velocities reflecting large-scale infall, showing that the structure of the envelope

  10. Morphological Algorithms For The Analysis Of Pavement Structure

    NASA Astrophysics Data System (ADS)

    Grivas, Dimitri A.; Skolnick, Michael M.

    1989-11-01

    The applicability of morphological image processing techniques for the description of condition and analysis of pavement surfaces is examined. Morphological techniques can be used in the measurement of pavement media consisting of grain (aggregates) and binding substances (bituminous or Portland cement mixtures). Measurements of size and size distributions on surface features related to texture and distresses can be obtained via morphological opening and closing transformations and distributions. When correlated with actual physical measurements of such quantities, the presented morphological measures of size and size distributions may prove to be useful in characterizing the surface condition of both asphalt and concrete pavement structures.

  11. Morphology of the Galaxy Distribution from Wavelet Denoising

    NASA Astrophysics Data System (ADS)

    Martínez, Vicent J.; Starck, Jean-Luc; Saar, Enn; Donoho, David L.; Reynolds, Simon C.; de la Cruz, Pablo; Paredes, Silvestre

    2005-11-01

    We have developed a method based on wavelets to obtain the true underlying smooth density from a point distribution. The goal has been to reconstruct the density field in an optimal way, ensuring that the morphology of the reconstructed field reflects the true underlying morphology of the point field, which, as the galaxy distribution, has a genuinely multiscale structure, with near-singular behavior on sheets, filaments, and hot spots. If the discrete distributions are smoothed using Gaussian filters, the morphological properties tend to be closer to those expected for a Gaussian field. The use of wavelet denoising provides us with a unique and more accurate morphological description.

  12. Robust Morphological Averages in Three Dimensions for Anatomical Atlas Construction

    NASA Astrophysics Data System (ADS)

    Márquez, Jorge; Bloch, Isabelle; Schmitt, Francis

    2004-09-01

    We present original methods for obtaining robust, anatomical shape-based averages of features of the human head anatomy from a normal population. Our goals are computerized atlas construction with representative anatomical features and morphopometry for specific populations. A method for true-morphological averaging is proposed, consisting of a suitable blend of shape-related information for N objects to obtain a progressive average. It is made robust by penalizing, in a morphological sense, the contributions of features less similar to the current average. Morphological error and similarity, as well as penalization, are based on the same paradigm as the morphological averaging.

  13. Non-Porod behavior in systems with rough morphologies.

    PubMed

    Shrivastav, Gaurav P; Banerjee, Varsha; Puri, Sanjay

    2014-10-01

    Many experiments yield multi-scale morphologies which are smooth on some length scales and fractal on others. Accurate statements about morphological properties, e.g., roughness exponent, fractal dimension, domain size, interfacial width, etc. are obtained from the correlation function and structure factor. In this paper, we present structure factor data for two systems: (a) droplet-in-droplet morphologies of double-phase-separating mixtures; and (b) ground-state morphologies in dilute anti-ferromagnets. An important characteristic of the scattering data is a non-Porod tail, which is associated with scattering off rough domains and interfaces.

  14. Polymer Morphological Change Induced by Terahertz Irradiation

    PubMed Central

    Hoshina, Hiromichi; Suzuki, Hal; Otani, Chiko; Nagai, Masaya; Kawase, Keigo; Irizawa, Akinori; Isoyama, Goro

    2016-01-01

    As terahertz (THz) frequencies correspond to those of the intermolecular vibrational modes in a polymer, intense THz wave irradiation affects the macromolecular polymorph, which determines the polymer properties and functions. THz photon energy is quite low compared to the covalent bond energy; therefore, conformational changes can be induced “softly,” without damaging the chemical structures. Here, we irradiate a poly(3-hydroxybutylate) (PHB) / chloroform solution during solvent casting crystallization using a THz wave generated by a free electron laser (FEL). Morphological observation shows the formation of micrometer-sized crystals in response to the THz wave irradiation. Further, a 10−20% increase in crystallinity is observed through analysis of the infrared (IR) absorption spectra. The peak power density of the irradiating THz wave is 40 MW/cm2, which is significantly lower than the typical laser intensities used for material manipulation. We demonstrate for the first time that the THz wave effectively induces the intermolecular rearrangement of polymer macromolecules. PMID:27272984

  15. Penis morphology in a Burmese amber harvestman.

    PubMed

    Dunlop, Jason A; Selden, Paul A; Giribet, Gonzalo

    2016-02-01

    A unique specimen of the fossil harvestman Halitherses grimaldii Giribet and Dunlop, 2005 (Arachnida: Opiliones) from the Cretaceous (ca. 99 Ma) Burmese amber of Myanmar reveals a fully extended penis. This is the first record of a male copulatory organ of this nature preserved in amber and is of special importance due to the age of the deposit. The penis has a slender, distally flattened truncus, a spatulate heart-shaped glans and a short distal stylus, twisted at the tip. In living harvestmen, the penis yields crucial characters for their systematics. Male genital morphology in H. grimaldii appears to be unique among the wider Dyspnoi clade to which this fossil belongs. The large eyes in the fossil differ markedly from other members of the subfamily Ortholasmatinae to which H. grimaldii was originally referred. Based on recent data, it has been argued that large eyes may be plesiomorphic for Palpatores (i.e. the suborders Eupnoi and Dyspnoi), potentially rendering this character plesiomorphic for the fossil too. Thus, the unique structure of the penis seen here, and the probable lack of diaphanous teeth, present in all other extant non-acropsopilionid Dyspnoi, suggest that H. grimaldii represents a new, extinct family of large-eyed dyspnoid harvestmen, Halithersidae fam. nov.; a higher taxon in amber diagnosed here on both somatic and genital characters.

  16. Penis morphology in a Burmese amber harvestman

    NASA Astrophysics Data System (ADS)

    Dunlop, Jason A.; Selden, Paul A.; Giribet, Gonzalo

    2016-02-01

    A unique specimen of the fossil harvestman Halitherses grimaldii Giribet and Dunlop, 2005 (Arachnida: Opiliones) from the Cretaceous (ca. 99 Ma) Burmese amber of Myanmar reveals a fully extended penis. This is the first record of a male copulatory organ of this nature preserved in amber and is of special importance due to the age of the deposit. The penis has a slender, distally flattened truncus, a spatulate heart-shaped glans and a short distal stylus, twisted at the tip. In living harvestmen, the penis yields crucial characters for their systematics. Male genital morphology in H. grimaldii appears to be unique among the wider Dyspnoi clade to which this fossil belongs. The large eyes in the fossil differ markedly from other members of the subfamily Ortholasmatinae to which H. grimaldii was originally referred. Based on recent data, it has been argued that large eyes may be plesiomorphic for Palpatores (i.e. the suborders Eupnoi and Dyspnoi), potentially rendering this character plesiomorphic for the fossil too. Thus, the unique structure of the penis seen here, and the probable lack of diaphanous teeth, present in all other extant non-acropsopilionid Dyspnoi, suggest that H. grimaldii represents a new, extinct family of large-eyed dyspnoid harvestmen, Halithersidae fam. nov.; a higher taxon in amber diagnosed here on both somatic and genital characters.

  17. {GUVI} Observations of Night Time Ionospheric Morphology

    NASA Astrophysics Data System (ADS)

    Swenson, C. M.; Christensen, A. B.; Walterscheid, R. J.; Paxton, L. J.; Meng, C. I.; Craven, J. D.; Meier, R. R.; Strickland, D. J.; Crowley, G.

    2002-05-01

    The TIMED spacecraft is currently mapping the nighttime Earth disk and limb with the Global Ultraviolet Imager (GUVI). Images are made in the OI 135.6 nm line which is excited by the recombination of O+ ions. The intensity in these disk images is related to the total electron content of the ionosphere and density profiles can be recovered from the limb scans. Prominent in these images are UV signatures of the Equatorial Anomaly that was first imaged by the DE-1 satellite. Data is currently available from essentially the same local time and is suitable for the study of the longitudinal dependence of the Anomalies. It is known that the Earth's ionosphere shows the occurrence large longitudinal and latitudinal variations in the F-region plasma density that change with season and solar cycle. These plasma density fluctuations occur over a very large range of scale sizes and have been observed by for about three decades by satellites [e.g., ISIS 2, ESRO-4, Atmosphere Explorers, Dynamics Explorer-2, San Marco II, DMSP, etc.]. Their morphology, origin, day-to-day variability, and predictability are still not well understood. The GUVI night data that gives insight into these largest scale structures will be discussed.

  18. Earth Sphericity Effects on Subduction Morphology

    NASA Astrophysics Data System (ADS)

    Morra, G.; Chatelain, P.; Tackley, P.; Koumoutsakos, P.

    2007-12-01

    We present here the first application in Geodynamics of a Multipole accelerated Boundary Element Method (FMM- BEM) for Stokes Flow. The approach offers the advantage of a reduced number of computational elements and linear scaling with the problem size. We show that this numerical mehod can be fruitfully applied to the simulation of several geodynamic systems at the planetary scale in spheical coordinates and we suggest a general appraoch for modeling combined mantle convection and plate tectonics. The potentialities of the approach are shown investigating the effect played by Earth sphericity on the subduction of a very wide oceanic lithosphere , comparing the morphology of the subducted lithosphere in a spherical and in flat setting. The results show a striking difference between the two models: while the slab on a "flat Earth" shows slight undulation, the same subducting plate on a spherical Earth-like setting presents a distinct folding below the trench far from the edges, with wavelength of (1000km-2000km) as Pacific trenches.

  19. Morphology and biomechanics of human heart

    NASA Astrophysics Data System (ADS)

    Chelnokova, Natalia O.; Golyadkina, Anastasiya A.; Kirillova, Irina V.; Polienko, Asel V.; Ivanov, Dmitry V.

    2016-03-01

    Object of study: A study of the biomechanical characteristics of the human heart ventricles was performed. 80 hearts were extracted during autopsy of 80 corpses of adults (40 women and 40 men) aged 31-70 years. The samples were investigated in compliance with the recommendations of the ethics committee. Methods: Tension and compression tests were performed with help of the uniaxial testing machine Instron 5944. Cardiometry was also performed. Results: In this work, techniques for human heart ventricle wall biomechanical properties estimation were developed. Regularities of age and gender variability in deformative and strength properties of the right and left ventricle walls were found. These properties were characterized by a smooth growth of myocardial tissue stiffness and resistivity at a relatively low strain against reduction in their strength and elasticity from 31-40 to 61-70 years. It was found that tissue of the left ventricle at 61-70 years had a lower stretchability and strength compared with tissues of the right ventricle and septum. These data expands understanding of the morphological organization of the heart ventricles, which is very important for the development of personalized medicine. Taking into account individual, age and gender differences of the heart ventricle tissue biomechanical characteristics allows to rationally choosing the type of patching materials during reconstructive operations on heart.

  20. [Concept of polymerization and oligomerization in morphology].

    PubMed

    Zamorskiĭ, A D

    1980-06-01

    The animal body consists of a large number of parts (organs, organoids, parts of organs etc.). This is reflected in names of different taxa including the words "poly" and "oligo" and has been laid into the bases of V.A. Dogiel's conception on polymerization and oligomerization. The least developed part of the conception dedicated to the hosts of organs is critically considered. The organs are divided into two principally different forms: diffuse hosts of similar organs and close hosts of similar elements in the same organ. A great importance of V.A. Dogiel's conception for foundation of a new section in morphology is demonstrated--the notion on hosts of organs. Failures in terminology and that in keeping the principle of homology together with ignoring the close hosts resulted in certain disadvantages of V.A. Dogiel's conception mentioned in the literature. Analysis of both forms mentioned above and that of their evolutional development helped to eradicate the disadvantages pointed above from V.A. Dogiel's conception. Biochemical terminology corresponding to biological tradition is the most suitable for V.A. Dogiel's conception. Besides hosts of organs, another components of the animal body are separate organs or parts of organs. Therefore, it is possible to divide all the animals according to their body structure into polymeres and heteromeres; this approach is also applicable in organs' anatomy.

  1. The Altay falcon: Origin, morphology and distribution

    USGS Publications Warehouse

    Ellis, D.H.

    1995-01-01

    The systematic position of the Altay falcon (Falco altaicus lorenzi) is perhaps the most enigmatic question lingering in falcon taxonomy. First reported to science in 1811, it has been treated as a race of the gyrfalcon (F. rusticolus), as a race of the saker (F. cherrug), as two separate species (F. lorenzi and F. altaicus), and as one to three color morphs of either the saker or the gyrfalcon. Ironically, two or even more of these explanations may be correct. Of 53 specimens examined, at least two are misidentified gyrfalcons, a score I dismiss as typical sakers, but a sizeable group (N = 34) is retained as representing what I consider to be the true Altay falcon type. Three adult color morphs exist: red, brown and grey. The red-backed morph closely resembles some eastern sakers. The chocolate morph resembles the black gyrfalcon from Labrador. The grey morph resembles the grey morph of the gyrfalcon. Ecological, geographical and morphological information contribute to the conclusion that this core group represents a gyrfalcon-saker hybrid that is very likely being swamped into obscurity through back crosses with the saker. The breeding range reported herein (Altay-Sayan Mountains) is greatly contracted from that previously reported. The true identify of the Altay falcon will be resolved by molecular genetics.

  2. Characterizing the morphology of protein binding patches.

    PubMed

    Malod-Dognin, Noël; Bansal, Achin; Cazals, Frédéric

    2012-12-01

    Let the patch of a partner in a protein complex be the collection of atoms accounting for the interaction. To improve our understanding of the structure-function relationship, we present a patch model decoupling the topological and geometric properties. While the geometry is classically encoded by the atomic positions, the topology is recorded in a graph encoding the relative position of concentric shells partitioning the interface atoms. The topological-geometric duality provides the basis of a generic dynamic programming-based algorithm comparing patches at the shell level, which may favor topological or geometric features. On the biological side, we address four questions, using 249 cocrystallized heterodimers organized in biological families. First, we dissect the morphology of binding patches and show that Nature enjoyed the topological and geometric degrees of freedom independently while retaining a finite set of qualitatively distinct topological signatures. Second, we argue that our shell-based comparison is effective to perform atomic-level comparisons and show that topological similarity is a less stringent than geometric similarity. We also use the topological versus geometric duality to exhibit topo-rigid patches, whose topology (but not geometry) remains stable upon docking. Third, we use our comparison algorithms to infer specificity-related information amidst a database of complexes. Finally, we exhibit a descriptor outperforming its contenders to predict the binding affinities of the affinity benchmark. The softwares developed with this article are availablefrom http://team.inria.fr/abs/vorpatch_compatch/.

  3. Dimensional measurements and operators in mathematical morphology

    NASA Astrophysics Data System (ADS)

    Soille, Pierre; Serra, Jean C.; Rivest, Jean-Francois

    1992-04-01

    In mathematical morphology, grey tone images are often considered as 3D Euclidean sets through their umbra or subgraph. This model allows one to extend measurements for sets to grey tone images. It has been shown that any valid measurement on Euclidean sets should satisfy some basic constraints such as invariance to displacements and to magnifications. However, when applied to subgraphs, these measurements may be meaningless as the image plane is not homogeneous with the grey tone axis. An additional constraint is introduced called dimensionality. This property holds for the inhomogeneity of image dimensions. A measurement on a grey tone image will be dimensional if the same measurement applied to this image after a magnification of its image plane and an affine transform of its grey tone axis can be related to the initial measure. The authors first recall valid measurements on sets and their properties. Then it is shown how to generalize to grey tone images and the dimensionality constraint is introduced. Set measurements are then reviewed to determine those satisfying the dimensionality criterion and consideration is given to the measure of the fractal dimension in the light of this new criterion. Eventually, dimensionality must also be considered when processing images. This is illustrated by a segmentation experiment.

  4. The functional morphology of hooding in cobras.

    PubMed

    Young, Bruce A; Kardong, Kenneth V

    2010-05-01

    Many snakes, particularly cobras, form as part of a defensive display, a hood, an active lateral expansion of their neck skin and underlying musculature and ribs. We identified muscle groups possibly involved in hooding based on their attachments on the specialized ribs of the neck. We then used a combination of morphology, kinematic analysis, morphometrics, electromyography and muscle stimulation to test hypotheses about the functional basis of hooding. We confirmed that hood protraction and erection is an active process that begins cranially and extends caudally, often in stages, through the combined action of several sets of muscles. One set of axial muscles (levator costae and supracostalis lateralis superior) coursing along a line of action to rib displacement are the prime erectors acting to lift the hood. However, a second set of muscles connecting ribs to skin primarily keep the skin taut, rather than to displace the ribs relative to the vertebrae. A third set of muscles coursing between ribs function primarily to transmit forces between adjacent ribs rather than to move ribs. The maintenance of the erect hood requires continued muscle activity. Hood relaxation is due to both active muscle contraction of a fourth set of axial muscles and to passive recoil events in the costovertebral ligaments. The shape of the fully erect hood is reflective of the morphometrics of the underlying ribs, while the duration and kinematics of hood erection and relaxation are related to the behavioral context of the display.

  5. [Morphology of neurons of human subiculum proper].

    PubMed

    Stanković-Vulović, Maja; Zivanović-Macuzić, Ivana; Sazdanović, Predrag; Jeremić, Dejan; Tosevski, Jovo

    2010-01-01

    Subiculum proper is an archicortical structure of the subicular complex and presents the place of origin of great majority of axons of the whole hippocampal formation. In contrast to the hippocampus which has been intensively studied, the data about human subiculum proper are quite scarce. The aim of our study was to identify morphological characteristics of neurons of the human subiculum proper. The study was performed on 10 brains of both genders by using Golgi impregnation and Nissl staining. The subiculum has three layers: molecular, pyramidal and polymorphic layer. The dominant cell type in the pyramidal layer was the pyramidal neurons, which had pyramidal shaped soma, multiple basal dendrites and one apical dendrite. The nonpyramidal cells were scattered among the pyramidal cells of the pyramidal layer. The nonpyramidal cells were classified on: multipolar, bipolar and neurons with triangular-shaped soma. The neurons of the molecular layer of the human subiculum were divided into groups: bipolar and multipolar neurons. The most numerous cells of the polymorphic layer were bipolar and multipolar neurons.

  6. Balamuthia mandrillaris: Morphology, biology, and virulence

    PubMed Central

    Siddiqui, Ruqaiyyah; Khan, Naveed Ahmed

    2015-01-01

    Balamuthia mandrillaris is a protist pathogen that can cause encephalitis with a fatality rate of >95%. This is due to our incomplete understanding of the pathogenesis and pathophysiology of B. mandrillaris encephalitis. B. mandrillaris has two stages in its life cycle, an active trophozoite stage during which it divides mitotically. However, under unfavorable conditions, the trophozoite transforms into a dormant cyst stage. A major concern during the course of therapy is that B. mandrillaris can transform into cysts. Cysts are highly resistant to physical and chemical conditions and present a problem in successful antimicrobial chemotherapy. Several lines of evidence suggest that B. mandrillaris encephalitis develops as a result of hematogenous spread, but it is unclear how circulating amoebae enter the central nervous system and cause inflammation, blood-brain barrier disruption, and neuronal injury. Recent studies have identified several parasite-host determinants for B. mandrillaris translocation of the blood-brain barrier, and host inflammatory markers that may be associated with neuronal injury. These determinants may provide important targets for the prevention and treatment of this devastating infection. Here, we present a brief overview of the current understanding of the morphology, biology, pathogenesis, and pathophysiology of B. mandrillaris encephalitis. PMID:25709948

  7. Pituitary function and morphology in Fabry disease.

    PubMed

    Maione, Luigi; Tortora, Fabio; Modica, Roberta; Ramundo, Valeria; Riccio, Eleonora; Daniele, Aurora; Belfiore, Maria Paola; Colao, Annamaria; Pisani, Antonio; Faggiano, Antongiulio

    2015-11-01

    Endocrine abnormalities are known to affect patients with Fabry disease (FD). Pituitary gland theoretically represents an ideal target for FD because of high vascularization and low proliferation rate. We explored pituitary morphology and function in a cohort of FD patients through a prospectic, monocentric study at an Academic Tertiary Center. The study population included 28 FD patients and 42 sex and age-matched normal subjects. The protocol included a contrast enhancement pituitary MRI, the assessment of pituitary hormones, anti-pituitary, and anti-hypothalamus antibodies. At pituitary MRI, an empty sella was found in 11 (39%) FD patients, and in 2 (5%) controls (p < 0.001). Pituitary volume was significantly smaller in FD than in controls (p < 0.001). Determinants of pituitary volume were age and alpha-galactosidase enzyme activity. Both parameters resulted independently correlated at multivariate analysis. Pituitary function was substantially preserved in FD patients. Empty sella is a common finding in patients with FD. The major prevalence in the elderly supports the hypothesis of a progressive pituitary shrinkage overtime. Pituitary function seems not to be impaired in FD. An endocrine workup with pituitary hormone assessment should be periodically performed in FD patients, who are already at risk of cardiovascular complications.

  8. Cell Shape Dependent Regulation of Nuclear Morphology

    PubMed Central

    Chen, Bo; Co, Carlos; Ho, Chia-Chi

    2015-01-01

    Recent studies suggest that actin filaments are essential in how a cell controls its nuclear shape. However, little is known about the relative importance of membrane tension in determining nuclear morphology. In this study, we used adhesive micropatterned substrates to alter the cellular geometry (aspect ratio, size, and shape) that allowed direct membrane tension or without membrane lateral contact with the nucleus and investigate nuclear shape remodeling and orientation on a series of rectangular shapes. Here we showed that at low cell aspect ratios the orientation of the nucleus was regulated by actin filaments while cells with high aspect ratios can maintain nuclear shape and orientation even when actin polymerization was blocked. A model adenocarcinoma cell showed similar behavior in the regulation of nuclear shape in response to changes in cell shape but actin filaments were essential in maintaining cell shape. Our results highlight the two distinct mechanisms to regulate nuclear shape through cell shape control and the difference between fibroblasts and a model cancerous cell in cell adhesion and cell shape control. PMID:26210179

  9. Correlation of cerebral cortical morphology with behavior

    SciTech Connect

    Norton, S.

    1989-03-01

    Association between functional damage and damage to the central nervous system from toxic agents can be used to determine the value of behavioral tests as predictors of damage to the nervous system. Variability in data from behavioral tests may be caused, in part, by varying levels of structural differences in the nervous system. Stepwise multiple regression is one method for analyzing the relationship between variability in data resulting from linkage between functional and morphological or other parameters of the structure of the nervous system. As an example, the predictive value of four behavioral tests is assessed in detecting thinning of the cerebral cortex following gestational exposure of rats to ionizing radiation. In this analysis, there were seven independent variables for predicting cortical thickness. The sequence of number of times each variable was used in prediction, from most frequent to least frequent, was: angle of stride greater than negative geotaxis greater than continuous corridor greater than body weight greater than width of stride greater than length of stride greater than reflex suspension. The data support the concept that there are varying degrees of predictive associations between these functional and cortical parameters.

  10. Human Misato regulates mitochondrial distribution and morphology

    SciTech Connect

    Kimura, Masashi . E-mail: yo@gifu-u.ac.jp; Okano, Yukio

    2007-04-15

    Misato of Drosophila melanogaster and Saccharomyces cerevisiae DML1 are conserved proteins having a homologous region with a part of the GTPase family that includes eukaryotic tubulin and prokaryotic FtsZ. We characterized human Misato sharing homology with Misato of D. melanogaster and S. cerevisiae DML1. Tissue distribution of Misato exhibited ubiquitous distribution. Subcellular localization of the protein studied using anti-Misato antibody suggested that it is localized to the mitochondria. Further experiments of fractionating mitochondria revealed that Misato was localized to the outer membrane. The transfection of Misato siRNA led to growth deficiencies compared with control siRNA transfected HeLa cells, and the Misato-depleted HeLa cells showed apoptotic nuclear fragmentation resulting in cell death. After silencing of Misato, the filamentous mitochondrial network disappeared and fragmented mitochondria were observed, indicating human Misato has a role in mitochondrial fusion. To examine the effects of overexpression, COS-7 cells were transfected with cDNA encoding EGFP-Misato. Its overexpression resulted in the formation of perinuclear aggregations of mitochondria in these cells. The Misato-overexpressing cells showed low viability and had no nuclei or a small and structurally unusual ones. These results indicated that human Misato has a role(s) in mitochondrial distribution and morphology and that its unregulated expression leads to cell death.

  11. Capillary condensation as a morphological transition.

    PubMed

    Kornev, Konstantin G; Shingareva, Inna K; Neimark, Alexander V

    2002-02-25

    The process of capillary condensation/evaporation in cylindrical pores is considered within the idea of symmetry breaking. Capillary condensation/evaporation is treated as a morphological transition between the wetting film configurations of different symmetry. We considered two models: (i) the classical Laplace theory of capillarity and (ii) the Derjaguin model which takes into account the surface forces expressed in terms of the disjoining pressure. Following the idea of Everett and Haynes, the problem of condensation/evaporation is considered as a transition from bumps/undulations to lenses. Using the method of phase portraits, we discuss the mathematical mechanisms of this transition hidden in the Laplace and Derjaguin equations. Analyzing the energetic barriers of the bump and lens formation, it is shown that the bump formation is a prerogative of capillary condensation: for the vapor-liquid transition in a pore, the bump plays the same role as the spherical nucleus in a bulk fluid. We show also that the Derjaguin model admits a variety of interfacial configurations responsible for film patterning at specific conditions.

  12. Polymer Morphological Change Induced by Terahertz Irradiation

    NASA Astrophysics Data System (ADS)

    Hoshina, Hiromichi; Suzuki, Hal; Otani, Chiko; Nagai, Masaya; Kawase, Keigo; Irizawa, Akinori; Isoyama, Goro

    2016-06-01

    As terahertz (THz) frequencies correspond to those of the intermolecular vibrational modes in a polymer, intense THz wave irradiation affects the macromolecular polymorph, which determines the polymer properties and functions. THz photon energy is quite low compared to the covalent bond energy; therefore, conformational changes can be induced “softly,” without damaging the chemical structures. Here, we irradiate a poly(3-hydroxybutylate) (PHB) / chloroform solution during solvent casting crystallization using a THz wave generated by a free electron laser (FEL). Morphological observation shows the formation of micrometer-sized crystals in response to the THz wave irradiation. Further, a 10‑20% increase in crystallinity is observed through analysis of the infrared (IR) absorption spectra. The peak power density of the irradiating THz wave is 40 MW/cm2, which is significantly lower than the typical laser intensities used for material manipulation. We demonstrate for the first time that the THz wave effectively induces the intermolecular rearrangement of polymer macromolecules.

  13. Human Misato regulates mitochondrial distribution and morphology.

    PubMed

    Kimura, Masashi; Okano, Yukio

    2007-04-15

    Misato of Drosophila melanogaster and Saccharomyces cerevisiae DML1 are conserved proteins having a homologous region with a part of the GTPase family that includes eukaryotic tubulin and prokaryotic FtsZ. We characterized human Misato sharing homology with Misato of D. melanogaster and S. cerevisiae DML1. Tissue distribution of Misato exhibited ubiquitous distribution. Subcellular localization of the protein studied using anti-Misato antibody suggested that it is localized to the mitochondria. Further experiments of fractionating mitochondria revealed that Misato was localized to the outer membrane. The transfection of Misato siRNA led to growth deficiencies compared with control siRNA transfected HeLa cells, and the Misato-depleted HeLa cells showed apoptotic nuclear fragmentation resulting in cell death. After silencing of Misato, the filamentous mitochondrial network disappeared and fragmented mitochondria were observed, indicating human Misato has a role in mitochondrial fusion. To examine the effects of overexpression, COS-7 cells were transfected with cDNA encoding EGFP-Misato. Its overexpression resulted in the formation of perinuclear aggregations of mitochondria in these cells. The Misato-overexpressing cells showed low viability and had no nuclei or a small and structurally unusual ones. These results indicated that human Misato has a role(s) in mitochondrial distribution and morphology and that its unregulated expression leads to cell death.

  14. SAR Image Segmentation Using Morphological Attribute Profiles

    NASA Astrophysics Data System (ADS)

    Boldt, M.; Thiele, A.; Schulz, K.; Hinz, S.

    2014-08-01

    In the last years, the spatial resolution of remote sensing sensors and imagery has continuously improved. Focusing on spaceborne Synthetic Aperture Radar (SAR) sensors, the satellites of the current generation (TerraSAR-X, COSMO-SykMed) are able to acquire images with sub-meter resolution. Indeed, high resolution imagery is visually much better interpretable, but most of the established pixel-based analysis methods have become more or less impracticable since, in high resolution images, self-sufficient objects (vehicle, building) are represented by a large number of pixels. Methods dealing with Object-Based Image Analysis (OBIA) provide help. Objects (segments) are groupings of pixels resulting from image segmentation algorithms based on homogeneity criteria. The image set is represented by image segments, which allows the development of rule-based analysis schemes. For example, segments can be described or categorized by their local neighborhood in a context-based manner. In this paper, a novel method for the segmentation of high resolution SAR images is presented. It is based on the calculation of morphological differential attribute profiles (DAP) which are analyzed pixel-wise in a region growing procedure. The method distinguishes between heterogeneous and homogeneous image content and delivers a precise segmentation result.

  15. Morphology of pyroclastic cones and tectonics

    NASA Astrophysics Data System (ADS)

    Tibaldi, Alessandro

    1995-12-01

    The relationships between morphology and spatial distribution of 1315 Quaternary pyroclastic cones and coeval faulting of the volcanic substrate are analyzed in the following regions with different structural settings: Tepic Rift (Mexico), Ethiopian Rift, Mexican Volcanic Belt, Canary Archipelago, and Mount Etna. Field data and analog experiments of tephra cone emplacement and collapse enable the definition of a number of parameters which can be used to infer the geometry of the fracture feeding the magma to a pyroclastic cone. The strike of the feeding plane is directly related to: (1) the elongation of cone base and crater, (2) the location of depressions on the crater rim, and (3) the alignment of pyroclastic cones in relation to a given vent spacing. In addition, the strike and dip of faults affect the direction of cone breaching. These relationships are valid for volcanic substrate topographic surfaces with an inclination of less than 9° and are especially sensitive to fault escarpment and cone height, lava and cone density, and fault orientation with respect to the dip of the volcanic substrate topography. Relations 1 and 2 become more pronounced for regions undergoing extensional tectonics, where edifices also have a larger dimension. Whereas breaching in the direction of the fault dip is more widespread in regions under extension, breaching along the fault strike as well as the coincidence between fault strike and vent alignment are more frequent in regions with transcurrent or transtensional tectonics.

  16. Submarine Volcanic Morphology of Santorini Caldera, Greece

    NASA Astrophysics Data System (ADS)

    Nomikou, P.; Croff Bell, K.; Carey, S.; Bejelou, K.; Parks, M.; Antoniou, V.

    2012-04-01

    Santorini volcanic group form the central part of the modern Aegean volcanic arc, developed within the Hellenic arc and trench system, because of the ongoing subduction of the African plate beneath the European margin throughout Cenozoic. It comprises three distinct volcanic structures occurring along a NE-SW direction: Christianna form the southwestern part of the group, Santorini occupies the middle part and Koloumbo volcanic rift zone extends towards the northeastern part. The geology of the Santorini volcano has been described by a large number of researchers with petrological as well as geochronological data. The offshore area of the Santorini volcanic field has only recently been investigated with emphasis mainly inside the Santorini caldera and the submarine volcano of Kolumbo. In September 2011, cruise NA-014 on the E/V Nautilus carried out new surveys on the submarine volcanism of the study area, investigating the seafloor morphology with high-definition video imaging. Submarine hydrothermal vents were found on the seafloor of the northern basin of the Santorini caldera with no evidence of high temperature fluid discharges or massive sulphide formations, but only low temperature seeps characterized by meter-high mounds of bacteria-rich sediment. This vent field is located in line with the normal fault system of the Kolumbo rift, and also near the margin of a shallow intrusion that occurs within the sediments of the North Basin. Push cores have been collected and they will provide insights for their geochemical characteristics and their relationship to the active vents of the Kolumbo underwater volcano. Similar vent mounds occur in the South Basin, at shallow depths around the islets of Nea and Palaia Kameni. ROV exploration at the northern slopes of Nea Kameni revealed a fascinating underwater landscape of lava flows, lava spines and fractured lava blocks that have been formed as a result of 1707-1711 and 1925-1928 AD eruptions. A hummocky topography at

  17. The morphology of the Martian surface

    USGS Publications Warehouse

    Carr, M.H.

    1980-01-01

    Most of the southern hemisphere of Mars is densely cratered and stands 1-3 km above the topographic datum. The northern hemisphere is more sparsely cratered and elevations are generally below the datum. A broad rise, the Tharsis bulge, centered at 14?? S, 101?? W, is 8000 km across and 10 km above the datum at its summit. The densely cratered terrain has two main components; very ancient crust, nearly saturated with large craters, and younger intercrater plains. In many areas the older unit is fractured and extensively dissected by small channels. The younger intercrater plains are distinctly layered in places and less dissected, less fractured, and less cratered. Both units probably date from very early in the planet's history. Cratered plains cover much of the northern hemisphere and are highly variegated. Those around the large volcanoes are covered with numerous volcanic flows whereas in other areas the plains are featureless except for craters and lunar mare-like ridges. Between 40?? N and 60?? N the plains are complex with various kinds of striped and patterned ground, low escarpments, and isolated irregularly shaped mesas. Their peculiar morphology has been attributed, in part, to the repeated deposition and removal of volatile-rich debris layers. Along the boundary between the northern plains and the densely cratered terrain to the south, the plains and cratered terrain complexly inter-finger. The old terrain forms the high ground and appears to have undergone mass wasting on a large scale. In several areas, particularly south of Chryse Planitia, the old, cratered surface has collapsed to form chaotic terrain. Large channels, tens of kilometers wide and hundreds of kilometers long, with numerous characteristics suggestive of catastrophic flooding, commonly emerge from the chaotic areas. Much of the area between 50?? W and 180?? W and 50?? N and 50?? S is cut by fractures radial to the center of the Tharsis bulge. The equatorial canyon system, Valles

  18. Morphologie et syntaxe du francais (French Morphology and Syntax)

    ERIC Educational Resources Information Center

    Sourdot, Marc

    1977-01-01

    A study of the relationship of morphology and syntax to the communication process from the functionalist viewpoint. Topics considered are: morphological processes, that is the distinction between functional and contingent language facts; the degree of necessity of syntax; the difference between functionalism and traditional grammar. (Text is in…

  19. Non-cardiac morphological stigmata of congenital heart disease

    PubMed Central

    Livesley, Brian

    1971-01-01

    The recognition of morphological stigmata other than cardiac, which are now known to be associated with congenital heart disease, coupled with a familial occurrence, may permit diagnosis of specific cardiac lesions at a very early age. Eleven such morphological associations have been reviewed. ImagesFig. 1Fig. 2Fig. 4 PMID:4400598

  20. Morphological Analysis in Learning to Read Pseudowords in Hebrew

    ERIC Educational Resources Information Center

    Bar-On, Amalia; Ravid, Dorit

    2011-01-01

    This paper examines the role of morphology in gradeschool children's learning to read nonpointed Hebrew. It presents two experiments testing the reading of morphologically based nonpointed pseudowords. One hundred seventy-one Hebrew-speaking children and adolescents in seven age/schooling groups (beginning and end of 2nd, 3rd, 4th, 7th, and 11th…

  1. Morphology and Syntax in Late Talkers at Age 5

    ERIC Educational Resources Information Center

    Rescorla, Leslie; Turner, Hannah L.

    2015-01-01

    Purpose: This study reports age 5 morphology and syntax skills in late talkers identified at age 2 (n = 34) and typically developing comparison children (n = 20). Results: The late talkers manifested significant morphological delays at ages 3 and 4 relative to comparison peers. Based on the 14 morphemes analyzed at age 5, the only significant…

  2. Morphological innovation, diversification and invasion of a new adaptive zone

    PubMed Central

    Dumont, Elizabeth R.; Dávalos, Liliana M.; Goldberg, Aaron; Santana, Sharlene E.; Rex, Katja; Voigt, Christian C.

    2012-01-01

    How ecological opportunity relates to diversification is a central question in evolutionary biology. However, there are few empirical examples of how ecological opportunity and morphological innovation open new adaptive zones, and promote diversification. We analyse data on diet, skull morphology and bite performance, and relate these traits to diversification rates throughout the evolutionary history of an ecologically diverse family of mammals (Chiroptera: Phyllostomidae). We found a significant increase in diversification rate driven by increased speciation at the most recent common ancestor of the predominantly frugivorous subfamily Stenodermatinae. The evolution of diet was associated with skull morphology, and morphology was tightly coupled with biting performance, linking phenotype to new niches through performance. Following the increase in speciation rate, the rate of morphological evolution slowed, while the rate of evolution in diet increased. This pattern suggests that morphology stabilized, and niches within the new adaptive zone of frugivory were filled rapidly, after the evolution of a new cranial phenotype that resulted in a certain level of mechanical efficiency. The tree-wide speciation rate increased non linearly with a more frugivorous diet, and was highest at measures of skull morphology associated with morphological extremes, including the most derived Stenodermatines. These results show that a novel stenodermatine skull phenotype played a central role in the evolution of frugivory and increasing speciation within phyllostomids. PMID:22113035

  3. The Syntax-Semantics Interface in Distributed Morphology

    ERIC Educational Resources Information Center

    Kelly, Justin Robert

    2013-01-01

    Distributed Morphology (DM; Halle & Marantz 1993; Marantz 1997) is founded on the premise that the syntax is the only computational component of the grammar. Much research focuses on how this premise is relevant to the syntax-morphology interface in DM. In this dissertation, I examine theory-internal issues related to the syntax-semantics…

  4. On the Relationship between Morphology Knowledge and Quality of Translation

    ERIC Educational Resources Information Center

    Arbabi Aski, Mohammadreza

    2008-01-01

    The present study intended to investigate whether there is any relationship between morphological knowledge and quality of legal text translation from English to Persian and to what extent do Iranian M.A students of translation use morphological knowledge to guess the meaning of words when translating legal texts from English to Persian. To…

  5. Morphological Uniformity and the Null Subject Parameter in Adult SLA.

    ERIC Educational Resources Information Center

    Davies, William D.

    1996-01-01

    Focuses on the application of the Null Subject Parameter. Data reveals that some second-language learners exhibit knowledge that English is morphologically nonuniform yet still accept English null subject sentences. Findings disprove the Morphological Uniformity Hypothesis, indicating that any reformulation of the Null Subject Parameter must…

  6. Effect of hydroxyapatite surface morphology on cell adhesion.

    PubMed

    Iwamoto, Takashi; Hieda, Yohki; Kogai, Yasumichi

    2016-12-01

    We obtained hydroxyapatite (HAp) materials as a block by mixing HAp nanoparticles and polymer, and then calcining the mixtures. The surface morphology of the HAp materials was tuned by varying heat treatment conditions. After calcining the mixtures at 1200 or 800°C for 4h, the surface morphology of the HAp materials was flat or convexo-concave, respectively. The flat surface morphology, which showed micrometer-ordered grain boundaries, was formed by the aggregation of HAp nanoparticles. On the other hand, the convexo-concave surface morphology resulted from the agglomeration of HAp nanoparticles after heat treatment at 800°C for 4h with nanometer-ordered particle size. We tested cell adhesion to HAp materials with flat or convexo-concave surface morphology and found that cells adhered well to the flat HAp materials but not to the convexo-concave HAp materials. This technique for selectively preparing HAp materials with flat or convexo-concave surface morphology was very easy because we merely mixed commercial HAp nanoparticles with polymer and then calcined the mixtures. As a result, the heat treatment temperature affected the surface morphology of our HAp materials, and their surface morphologies contributed to cell adhesion independently of other material properties.

  7. Interspeaker Variability in Hard Palate Morphology and Vowel Production

    ERIC Educational Resources Information Center

    Lammert, Adam; Proctor, Michael; Narayanan, Shrikanth

    2013-01-01

    Purpose: Differences in vocal tract morphology have the potential to explain interspeaker variability in speech production. The potential acoustic impact of hard palate shape was examined in simulation, in addition to the interplay among morphology, articulation, and acoustics in real vowel production data. Method: High-front vowel production from…

  8. The Reciprocal Relations between Morphological Processes and Reading

    ERIC Educational Resources Information Center

    Kruk, Richard S.; Bergman, Krista

    2013-01-01

    Reciprocal relations between emerging morphological processes and reading skills were examined in a longitudinal study tracking children from Grade 1 through Grade 3. The aim was to examine predictive relationships between productive morphological processing involving composing and decomposing of inflections and derivations, reading ability for…

  9. Phonetic Pause Unites Phonology and Semantics against Morphology and Syntax

    ERIC Educational Resources Information Center

    Sakarna, Ahmad Khalaf; Mobaideen, Adnan

    2012-01-01

    The present study investigates the phonological effect triggered by the different types of phonetic pause used in Quran on morphology, syntax, and semantics. It argues that Quranic pause provides interesting evidence about the close relation between phonology and semantics, from one side, and semantics, morphology, and syntax, from the other…

  10. Morphology in Malay-English Biliteracy Acquisition: An Intervention Study

    ERIC Educational Resources Information Center

    Zhang, Dongbo

    2016-01-01

    This intervention study examined the effect of English morphological instruction on the development of English as well as Malay morphological awareness and word reading abilities among Malay-English bilingual fourth graders in Singapore, where English is the medium of instruction. The intervention group experienced semester-long instruction in…

  11. Using Inquiry and Phylogeny: To Teach Comparative Morphology

    ERIC Educational Resources Information Center

    Giese, Alan R.

    2005-01-01

    A description on inquiry-based approach to teaching comparative vertebrate, skeletal morphology is presented that could be easily adapted to teach comparative morphology for any discipline, provided that sufficient physical models are available. This approach requires students to probe the material world for evidence that would allow them to…

  12. Morphological Degradation Models and their Use in Document Image Restoration

    DTIC Science & Technology

    2001-02-01

    Restoration Qigong Zheng and Tapas Kanungo Language and Media Processing Laboratory Center for Automation Research University of Maryland College Park...IIS9987944 February 2001 Morphological Degradation Models and their Use in Document Image Restoration Qigong Zheng and Tapas Kanungo Morphological...Degradation Models and their Use in Document Image Restoration Qigong Zheng and Tapas Kanungo Language and Media Processing Laboratory Center for Automation

  13. Morphological innovation, diversification and invasion of a new adaptive zone.

    PubMed

    Dumont, Elizabeth R; Dávalos, Liliana M; Goldberg, Aaron; Santana, Sharlene E; Rex, Katja; Voigt, Christian C

    2012-05-07

    How ecological opportunity relates to diversification is a central question in evolutionary biology. However, there are few empirical examples of how ecological opportunity and morphological innovation open new adaptive zones, and promote diversification. We analyse data on diet, skull morphology and bite performance, and relate these traits to diversification rates throughout the evolutionary history of an ecologically diverse family of mammals (Chiroptera: Phyllostomidae). We found a significant increase in diversification rate driven by increased speciation at the most recent common ancestor of the predominantly frugivorous subfamily Stenodermatinae. The evolution of diet was associated with skull morphology, and morphology was tightly coupled with biting performance, linking phenotype to new niches through performance. Following the increase in speciation rate, the rate of morphological evolution slowed, while the rate of evolution in diet increased. This pattern suggests that morphology stabilized, and niches within the new adaptive zone of frugivory were filled rapidly, after the evolution of a new cranial phenotype that resulted in a certain level of mechanical efficiency. The tree-wide speciation rate increased non linearly with a more frugivorous diet, and was highest at measures of skull morphology associated with morphological extremes, including the most derived Stenodermatines. These results show that a novel stenodermatine skull phenotype played a central role in the evolution of frugivory and increasing speciation within phyllostomids.

  14. Morphological stability and kinetics in crystal growth from vapors

    NASA Technical Reports Server (NTRS)

    Rosenberger, Franz

    1990-01-01

    The following topics are discussed: (1) microscopy image storage and processing system; (2) growth kinetics and morphology study with carbon tetrabromide; (3) photothermal deflection vapor growth setup; (4) bridgman growth of iodine single crystals; (5) vapor concentration distribution measurement during growth; and (6) Monte Carlo modeling of anisotropic growth kinetics and morphology. A collection of presentations and publications of these results are presented.

  15. External morphology of stable fly (Diptera: Muscidae) larvae

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Scanning electron microscopy was used to examine the external morphology of first-, second-, and third-instar stable flies (Stomoxys calcitrans (L.)). In the cephalic region, the antennae, labial lobe, and maxillary palpi are morphologically similar among instars. Antennae comprise a prominent ante...

  16. Morphology and Spelling in Arabic: Development and Interface

    ERIC Educational Resources Information Center

    Taha, Haitham; Saiegh-Haddad, Elinor

    2017-01-01

    In the current study, two experiments were carried out: the first tested the development of derivational root and word-pattern morphological awareness in Arabic; the second tested morphological processing in Arabic spelling. 143 Arabic native speaking children with normal reading skills in 2nd, 4th and 6th grade participated in the study. The…

  17. Morphology of LDPE-poly(3-hydroxybutyrate) films

    NASA Astrophysics Data System (ADS)

    Ol'khov, A. A.; Vlasov, S. V.; Shibryaeva, L. S.; Kosenko, R. Yu.; Iordanskii, A. L.

    2012-07-01

    The structure and morphology of biodegradable extruded polymeric films based on LDPE and (PHB) were studied by a combination of methods including polarization IR spectroscopy, DSC, and scanning electron microscopy (SEM). The components of LDPE-PHB blends containing 1-32% PHB are immiscible and form morphological structures (phases) with well distinguishable phase boundaries between dispersed phase and dispersion matrix.

  18. Morphology and Literacy: Getting Our Heads in the Game

    ERIC Educational Resources Information Center

    Green, Laura

    2009-01-01

    Purpose: This prologue introduces the clinical forum, briefly discusses the importance of morphology in literacy, and informs the reader of the scope of the included articles. Method: The concept of morphology is reviewed, contributing authors are introduced, and a brief summary of each of the 5 forum articles is provided. Conclusion: The studies…

  19. Functional morphology of the Neandertal scapular glenoid fossa.

    PubMed

    Macias, Marisa E; Churchill, Steven E

    2015-01-01

    Neandertals and Homo sapiens are known to differ in scapular glenoid fossa morphology. Functional explanations may be appropriate for certain aspects of glenoid fossa morphology; however, other factors--e.g., allometry, evolutionary development--must be addressed before functional morphology is considered. Using three-dimensional geometric morphometrics, shape of the scapular glenoid fossa was compared among Neandertals, early and recent modern humans, chimpanzees, orangutans, Australopithecus afarensis, and Au. sediba. Permutation analysis revealed that side, sex, and lifestyle did not correlate with shape. Of the features we found to differ between groups, anterior glenoid rim morphology and fossa curvature did not correlate with the aforementioned shape variables; thus, a functional explanation is appropriate for these components of glenoid fossa shape. Shared morphology among recent humans and chimpanzees (to the exclusion of Neandertals and orangutans) suggests independent forces contributing to these morphological configurations. Potential explanations include adaptations to habitual behavior and locomotor adaptations in the scapulae of recent humans and chimpanzees; these explanations are supported by clinical and experimental literature. The absence of these morphological features in Neandertals may support the lack of these selective forces on their scapular glenoid fossa morphology.

  20. The Aspect Hypothesis: Development of Morphology and Appropriateness of Use

    ERIC Educational Resources Information Center

    Comajoan, Llorenc

    2006-01-01

    According to the aspect hypothesis (Andersen & Shirai, 1996; Bardovi-Harlig, 2000), perfective morphology emerges before imperfective morphology, it is first used in telic predicates (achievements and accomplishments) and it later extends to atelic predicates (activities and states). The opposite development is hypothesized for imperfective…

  1. When a general morphology allows many habitat uses.

    PubMed

    Tulli, María J; Cruz, Félix B; Kohlsdorf, Tiana; Abdala, Virginia

    2016-11-01

    During the last decades the study of functional morphology received more attention incorporating more detailed data corresponding to the internal anatomy that together contribute for a better understanding of the functional basis in locomotion. Here we focus on 2 lizard families, Tropiduridae and Liolaemidae, and use information related to muscle-tendinous and external morphology traits of hind legs. We investigate whether the value of the traits analyzed tend to exhibit a reduced phenotypic variation produced by stabilizing selection, and whether species showing specialization in their habitat use will also exhibit special morphological features related to it. As a result, we identified that evolution of hind limb traits is mainly explained by the Ornstein-Uhlenbeck model, suggesting stabilizing selection. Liolaemids and tropidurids show clear ecomorphological trends in the variables considered, with sand lizards presenting the most specialized morphological traits. Some ecomorphological trends differ between the 2 lineages, and traits of internal morphology tend to be more flexible than those of external morphology, restricting the ability to identify ecomorphs shared between these 2 lineages. Conservative traits of external morphology likely explain such restriction, as ecomorphs have been historically defined in other lizard clades based on variation of external morphology.

  2. Contributions of Morphological Skill to Children's Essay Writing

    ERIC Educational Resources Information Center

    Northey, Mary; McCutchen, Deborah; Sanders, Elizabeth A.

    2016-01-01

    Morphological skills have previously been found to reliably predict reading skill, including word reading, vocabulary, and comprehension. However, less is known about how morphological skills might contribute to writing skill, aside from its well-documented role in the development of spelling. This correlational study examines whether…

  3. Morphological Awareness and Chinese Children's Literacy Development: An Intervention Study

    ERIC Educational Resources Information Center

    Wu, Xiaoying; Anderson, Richard C.; Li, Wenling; Wu, Xinchun; Li, Hong; Zhang, Jie; Zheng, Qiu; Zhu, Jin; Shu, Hua; Jiang, Wei; Chen, Xi; Wang, Qiuying; Yin, Li; He, Yeqin; Packard, Jerome; Gaffney, Janet S.

    2009-01-01

    The purpose of this study was to investigate the relationship between morphological awareness and Chinese children's literacy development. Of the 169 children from elementary schools in Beijing, China, who participated in the study, about half received enhanced instruction on the morphology of characters and words in the first and second grade. At…

  4. Dissociations in Processing Derivational Morphology: The Right Basal Ganglia Involvement

    ERIC Educational Resources Information Center

    Marangolo, Paola; Piras, Fabrizio

    2008-01-01

    In the neuropsychological literature, there is converging evidence for a dominant role of the left hemisphere in morphological processing. However, two right hemisphere patients were described with a clear dissociation between impaired derivational morphology and preserved inflectional processing. A recent fMRI experiment confirmed the involvement…

  5. New Evidence for Morphological Errors in Deep Dyslexia

    ERIC Educational Resources Information Center

    Rastle, Kathleen; Tyler, Lorraine K.; Marslen-Wilson, William

    2006-01-01

    Morphological errors in reading aloud (e.g., "sexist" [right arrow] "sexy") are a central feature of the symptom-complex known as deep dyslexia, and have historically been viewed as evidence that representations at some level of the reading system are morphologically structured. However, it has been proposed (Funnell, 1987) that morphological…

  6. Evidence for Early Morphological Decomposition: Combining Masked Priming with Magnetoencephalography

    PubMed Central

    Lehtonen, Minna; Monahan, Philip J.; Poeppel, David

    2015-01-01

    Are words stored as morphologically structured representations? If so, when during word recognition are morphological pieces accessed? Recent masked priming studies support models that assume early decomposition of (potentially) morphologically complex words. The electrophysiological evidence, however, is inconsistent. We combined masked morphological priming with magneto-encephalography (MEG), a technique particularly adept at indexing processes involved in lexical access. The latency of an MEG component peaking, on average, 220 msec post-onset of the target in left occipito-temporal brain regions was found to be sensitive to the morphological prime– target relationship under masked priming conditions in a visual lexical decision task. Shorter latencies for related than unrelated conditions were observed both for semantically transparent (cleaner–CLEAN) and opaque (corner–CORN) prime–target pairs, but not for prime–target pairs with only an orthographic relationship (brothel–BROTH). These effects are likely to reflect a prelexical level of processing where form-based representations of stems and affixes are represented and are in contrast to models positing no morphological structure in lexical representations. Moreover, we present data regarding the transitional probability from stem to affix in a post hoc comparison, which suggests that this factor may modulate early morphological decomposition, particularly for opaque words. The timing of a robust MEG component sensitive to the morphological relatedness of prime–target pairs can be used to further understand the neural substrates and the time course of lexical processing. PMID:21557645

  7. Comparative retinal morphology of the platypus.

    PubMed

    Zeiss, Caroline J; Schwab, Ivan R; Murphy, Christopher J; Dubielzig, Richard W

    2011-08-01

    The purpose of this study is to identify evolutionary origin and fate of anatomic features of the duck-billed platypus eye. Eyes from the duck-billed platypus and four key evolutionary basal vertebrates (Pacific hagfish, north hemisphere sea lamprey, and Australian and South American lungfishes) were prepared for light microscopy. In addition to a standard panel of stains, tissues were immunostained against a variety of rod and cone opsins. Finally, published opsin sequences of platypus and several other vertebrate species were aligned and compared with immunohistochemical results. A complete scleral cartilage similar to that seen in birds, reptiles and amphibians encloses the platypus eye. This feature is present in sharks and rays, and in extant relatives of tetrapods, the lungfishes. The choroid lacks a tapetum. The retina is largely avascular and is rod-dominated, with a minority of red- and blue- cone immunoreactive photoreceptors. Like marsupials and many nonmammalian vertebrates, cones contain clear inner segment droplets. Double cones were present, a feature not found in eutherian mammals or marsupials. Evaluation of opsins indicates that red and blue immunoreactive cone opsins, but not rhodopsin, are present in the most basal of the extant species examined, the Pacific hagfish. Rhodopsin appears in the Australian and South American lungfishes, establishing emergence of this pigment in an extant relative of tetrapods. Unlike eyes of eutherian mammals, the platypus eye has retained morphologic features present in early tetrapods such as amphibians and their evolutionarily basal sister group, the lungfishes. These include scleral cartilage, double cones and cone droplets. In the platypus, as in other mammals, rod rhodopsin is the predominant photoreceptor pigment, at expense of the cone system.

  8. Clinical and morphological characteristics of cutaneous melanoma.

    PubMed

    Balaban, Jagoda; Ninković Baroš, Djuka; Grujić, Dragana; Starović, Dragana; Ćelić, Milanka

    2014-01-01

    The incidence of cutaneous melanoma has increased significantly worldwide over the last several decades. The aim of this study is to determine clinical and morphology characteristics of primary melanoma, since some of them are important prognostic factors. This retrospective study included 172 patients. The data were collected by the Consulting team for malignant skin tumors in the Banja Luka Clinical Centre from 2009 to 2011. We did not use dermoscopy as a diagnostic tool in our investigation. We determined that melanoma occurs equally commonly in both sexes, in women in the sixth decade and the seventh in men. The most common sub-type was nodular melanoma (59.5%, P<0.05), followed by superficial spreading (27.8%) and acral lentiginous melanoma (11.4%). The most common localization was on the back in men (34.3%) and on the legs in women (P<0.05). More than half of our patients (55.8%) had melanoma thickness from 1.0 to 4.0 mm, and 38% had a melanoma thicker than 4.0 mm. The average Breslow thickness is 4.6 mm. More women than men had melanoma thicker than 4 mm (P<0.05). Spread of the primary tumor localization was found in 31.4% of patients, more frequently in men than in women (P<0.05). In most cases it was abstraction of lymph nodes (P<0.05). The average thickness of the melanoma in our patients is much higher than the average in the world and the countries of Europe. The results of this study indicate a need for better unique regional registry in this part of Bosnia and Herzegovina and improvement of preventive measures in the early diagnosis of melanoma.

  9. Morphology of Gas Release in Physical Simulants

    SciTech Connect

    Daniel, Richard C.; Burns, Carolyn A.; Crawford, Amanda D.; Hylden, Laura R.; Bryan, Samuel A.; MacFarlan, Paul J.; Gauglitz, Phillip A.

    2014-07-03

    This report documents testing activities conducted as part of the Deep Sludge Gas Release Event Project (DSGREP). The testing described in this report focused on evaluating the potential retention and release mechanisms of hydrogen bubbles in underground radioactive waste storage tanks at Hanford. The goal of the testing was to evaluate the rate, extent, and morphology of gas release events in simulant materials. Previous, undocumented scoping tests have evidenced dramatically different gas release behavior from simulants with similar physical properties. Specifically, previous gas release tests have evaluated the extent of release of 30 Pa kaolin and 30 Pa bentonite clay slurries. While both materials are clays and both have equivalent material shear strength using a shear vane, it was found that upon stirring, gas was released immediately and completely from bentonite clay slurry while little if any gas was released from the kaolin slurry. The motivation for the current work is to replicate these tests in a controlled quality test environment and to evaluate the release behavior for another simulant used in DSGREP testing. Three simulant materials were evaluated: 1) a 30 Pa kaolin clay slurry, 2) a 30 Pa bentonite clay slurry, and 3) Rayleigh-Taylor (RT) Simulant (a simulant designed to support DSGREP RT instability testing. Entrained gas was generated in these simulant materials using two methods: 1) application of vacuum over about a 1-minute period to nucleate dissolved gas within the simulant and 2) addition of hydrogen peroxide to generate gas by peroxide decomposition in the simulants over about a 16-hour period. Bubble release was effected by vibrating the test material using an external vibrating table. When testing with hydrogen peroxide, gas release was also accomplished by stirring of the simulant.

  10. Nanometer Scale Morphology of Bacteriogenic Mn Oxides

    NASA Astrophysics Data System (ADS)

    Perez, M.; Obraztsova, A.; Tebo, B. M.; Bargar, J. R.

    2005-12-01

    Manganese oxides, which are ubiquitous in surface waters, soils, and sediments, are believed to result from the bacterially catalyzed oxidation of Mn(II) to Mn(IV). Bacteriogenic Mn oxides exhibit high surface areas and degrade or oxidize a variety of organic and inorganic compounds. Via these reactions, Mn oxides influence the biogeochemical cycling of micronutrients and help to control the composition of natural waters. Recent EXAFS (extended X-ray absorption fine structure) and WAXS (wide angle X-ray scattering) investigations of bacteriogenic Mn oxides indirectly suggest that particles are as small as 10 or 20 nm , . However, no detailed systematic quantitative measurements of bacteriogenic Mn oxide particle sizes and morphology have been reported. We have characterized manganese oxides produced by the marine sporeforming bacterium Bacillus sp., strain SG-1 using SAXS (small angle X-ray scattering) and TEM (transmission electron microscopy). TEM measurements indicate that the particles are layered structures having basal-plane widths of several hundred nm. WAXS measurements indicate that particles are extremely thin, ~1nm thick, which corresponds to a single Mn oxide layer. The particles appear to have particularly high aspect ratios, with the majority of all structural MnO6 octahedral units exposed to solution. Furthermore, it follows that basal plane sites are the overwhelmingly dominant surface binding sites. Particles with such small dimensions often have properties that are intermediate between those of molecular clusters and bulk materials. Therefore, the reactivity of natural manganese oxides is expected to differ substantially from that of synthetic crystalline analogs.

  11. The Morphology and Sedimentology of Fluvial Megascours

    NASA Astrophysics Data System (ADS)

    Bull, J. M.; Vardy, M. E.; Sambrook Smith, G.; Best, J.; Dixon, S. J.; Goodbred, S. L., Jr.

    2015-12-01

    Scour zones in the World's largest rivers, or so-called "megascours", are extensive and dynamic features that are currently poorly understood in terms of their morphology and kinematics. Such scours can erode c. 50-60 metres below the water surface, extend laterally for 100s metres to kilometres, and may migrate kilometres in a single year. Understanding the evolution of such scour zones has important implications for improved flood and bank erosion prediction, better infrastructure planning (e.g. bridges, embankments), and differentiating between autocyclic and allocyclic erosion in the geological record (e.g. sequence stratigraphic applications). Here, we present results from two field seasons using geophysical techniques (high-resolution multibeam bathymetry and seismic reflection data using Chirp and Boomer sources) to study six scour zones in the Ganges-Jamuna-Padma-Meghna river system of Bangladesh. These scours include some of the World's largest confluences, as well as smaller distributaries, and those with varying levels of tidal influence. Seismic data from repeat surveys permit an accurate characterization of short-term scour evolution and associated deposits across two monsoonal flood peaks. Meanwhile, the bathymetric data reveals widespread deep scours (30-40 m) even in small, downstream distributary tidal channels, illustrating that megascours are present all the way to the subaerial delta fringe. Bathymetric analysis also shows a complex relationship between these scours and bedform distribution and orientation. This suggests the need for a new scaling for sand dune dimensions at such sites, and the need for substantial revisions to current ideas on the use of dune-scale cross-stratification to infer palaeoflow depths in the ancient sedimentary record.

  12. Morphology of rare-earth polymeric electrolytes

    SciTech Connect

    Puga, M.M.S.; Carlos, L.D.; Abrantes, T.M.A.

    1995-12-01

    The usual two-solvent casting technique was used to prepare a series of poly(ethylene oxide), PEO, and poly(propylene oxide), PPO, electrolytes containing trivalent salts of Eu, Nd, and Pr with concentrations between n = 80 and n = 3 (n is the number of ether oxygen atoms in the polymer chain per lanthanide cation). The films were characterized by differential scanning calorimetry, scanning electron microscopy/energy-dispersive X-ray microanalysis, and X-ray powder diffraction. The Eu{sup 3+} and Pr{sup 3+} electrolytes with n {ge} 8 exhibit an endothermic peak around 65{degrees}C, which is associated with the melting of crystalline PEO. Films with compositions 16 {ge} n {ge} 7 showed, in addition, a smaller endotherm around 60{degrees}C, which results from a eutectic phase of PEO and PEO/salt complex. The highly concentrated PEO{sub n}EuBr{sub 3} films, n {le} 6, are glassy, transparent, and fragile materials when no traces of water are detected. The stoichiometry of the high-melting-point crystalline complex observed for these Eu{sup 3+} electrolytes appears to be close to an oxygen-cation ratio of 3:1. The morphology of the Nd{sup 3+} electrolytes was found to be independent of the salt concentration. These films are characterized by the presence of a crystalline PEO phase and, probably, a nonstoichiometric PEO-NdCl{sub 3} complex. PPO-EuBr{sub 3} electrolytes are predominantly amorphous and formation of a salt-rich complex phase was also observed at high salt concentrations. 40 refs., 9 figs.

  13. Functional nasal morphology of chimaerid fishes.

    PubMed

    Howard, Lauren E; Holmes, William M; Ferrando, Sara; Maclaine, James S; Kelsh, Robert N; Ramsey, Andrew; Abel, Richard L; Cox, Jonathan P L

    2013-09-01

    Holocephalans (chimaeras) are a group of marine fishes comprising three families: the Callorhinchidae (callorhinchid fishes), the Rhinochimaeridae (rhinochimaerid fishes) and the Chimaeridae (chimaerid fishes). We have used X-ray microcomputed tomography and magnetic resonance imaging to characterise in detail the nasal anatomy of three species of chimaerid fishes: Chimaera monstrosa, C. phantasma and Hydrolagus colliei. We have shown that the nasal chamber of these three species is linked to the external environment by an incurrent channel and to the oral cavity by an excurrent channel via an oral groove. A protrusion of variable morphology is present on the medial wall of the incurrent channel in all three species, but is absent in members of the two other holocephalan families that we inspected. A third nasal channel, the lateral channel, functionally connects the incurrent nostril to the oral cavity, by-passing the nasal chamber. From anatomical reconstructions, we have proposed a model for the circulation of water, and therefore the transport of odorant, in the chimaerid nasal region. In this model, water could flow through the nasal region via the nasal chamber or the lateral channel. In either case, the direction of flow could be reversed. Circulation through the entire nasal region is likely to be driven primarily by the respiratory pump. We have identified several anatomical features that may segregate, distribute, facilitate and regulate flow in the nasal region and have considered the consequences of flow reversal. The non-sensory cilia lining the olfactory sensory channels appear to be mucus-propelling, suggesting that these cilia have a common protective role in cartilaginous fishes (sharks, rays and chimaeras). The nasal region of chimaerid fishes shows at least two adaptations to a benthic lifestyle, and suggests good olfactory sensitivity, with secondary folding enhancing the hypothetical flat sensory surface area by up to 70%.

  14. Research of Gear Fault Detection in Morphological Wavelet Domain

    NASA Astrophysics Data System (ADS)

    Hong, Shi; Fang-jian, Shan; Bo, Cong; Wei, Qiu

    2016-02-01

    For extracting mutation information from gear fault signal and achieving a valid fault diagnosis, a gear fault diagnosis method based on morphological mean wavelet transform was designed. Morphological mean wavelet transform is a linear wavelet in the framework of morphological wavelet. Decomposing gear fault signal by this morphological mean wavelet transform could produce signal synthesis operators and detailed synthesis operators. For signal synthesis operators, it was just close to orginal signal, and for detailed synthesis operators, it contained fault impact signal or interference signal and could be catched. The simulation experiment result indicates that, compared with Fourier transform, the morphological mean wavelet transform method can do time-frequency analysis for original signal, effectively catch impact signal appears position; and compared with traditional linear wavelet transform, it has simple structure, easy realization, signal local extremum sensitivity and high denoising ability, so it is more adapted to gear fault real-time detection.

  15. Crystalline Morphology of Propylene 1-Octene Random Copolymers

    NASA Astrophysics Data System (ADS)

    Jeon, Keesu; Alamo, Rufina G.

    2008-03-01

    The morphology of isotactic propylene 1-octene random copolymers has been studied by AFM, DSC, WAXS, and FTIR in an octene range of 10-20 mol %. Different morphologies were observed below and above 15 mol %. The morphological components in the higher counit copolymers are not of the lamellae-type, thicker than lamellae observed below 15 mol %, connected and isotropic in their orientation. Their global morphology is developed via nucleation and growth (NG) of spherulitic aggregates. The evolution of heat of fusion with time is also sigmoidal shape, typical of NG-type crystallization mechanism. WAXS diffractograms for the higher counit copolymers are devoid of crystalline reflections, except for small and broad peaks suggesting mesomorphic-like structures, which by FTIR show small contents of the 840 cm-1, 12 and higher units regularity bands, and hence formed of short helical sequences. The PO morphology is additionally compared with copolymers with ethylene, 1-butene and 1-hexene counits at matched contents.

  16. Vertical Craniofacial Morphology and its Relation to Temporomandibular Disorders

    PubMed Central

    Bavia, Paula Furlan

    2016-01-01

    ABSTRACT Objectives This study investigated the association between craniofacial morphology and temporomandibular disorders in adults. The influence of different craniofacial morphologies on painful temporomandibular disorders was also evaluated. Material and Methods A total of 200 subjects were selected, including 100 with temporomandibular disorders (TMD) and 100 without TMD (control), diagnosed by research diagnostic criteria for temporomandibular disorders. All subjects were submitted to lateral cephalometric radiographs, and classified as brachyfacial, mesofacial, or dolichofacial by Ricketts’ analysis. Data were analysed by Tukey-Kramer and Chi-square tests. Results No association between craniofacial morphology and TMD was found (P = 0.6622). However, brachyfacial morphology influences the presence of painful TMD (P = 0.0077). Conclusions Craniofacial morphology is not related to temporomandibular disorders in general. PMID:27489610

  17. The three-dimensional morphology of growing dendrites

    DOE PAGES

    Gibbs, J. W.; Mohan, K. A.; Gulsoy, E. B.; ...

    2015-07-03

    The processes controlling the morphology of dendrites have been of great interest to a wide range of communities, since they are examples of an out-of-equilibrium pattern forming system, there is a clear connection with battery failure processes, and their morphology sets the properties of many metallic alloys. We determine the three-dimensional morphology of free growing metallic dendrites using a novel X-ray tomographic technique that improves the temporal resolution by more than an order of magnitude compared to conventional techniques. These measurements show that the growth morphology of metallic dendrites is surprisingly different from that seen in model systems, the morphologymore » is not self-similar with distance back from the tip, and that this morphology can have an unexpectedly strong influence on solute segregation in castings. These experiments also provide benchmark data that can be used to validate simulations of free dendritic growth.« less

  18. Morphological Consequences of Frustration in ABC Triblock Polymers

    SciTech Connect

    Radlauer, Madalyn R.; Sinturel, Christophe; Asai, Yusuke; Arora, Akash; Bates, Frank S.; Dorfman, Kevin D.; Hillmyer, Marc A.

    2016-12-19

    Three poly(styrene)-block-poly(isoprene)-block-poly(lactide) (PS-b-PI-b-PLA, SIL) triblock terpolymers were synthesized and characterized in the bulk and as thin films. The pronounced incompatibility of the covalently connected PI and PLA led to significant frustration and the tendency to minimize their intermaterial dividing surface area. This resulted in the formation of a core–shell cylinder morphology with exaggerated nonconstant mean curvature from triblock polymers with equal block volume fractions rather than the more typical lamellar morphology. The effect of frustration was magnified in thin films by both confinement and interfacial interactions such that the PI domains became discontinuous. Self-consistent field theory (SCFT) calculations emphasize that the marked difference in the PS/PI and PI/PLA interaction parameters promotes the formation of nonlamellar morphologies. However, SCFT predicts that lamellar morphology is more stable than the observed cylindrical morphology, demonstrating a limitation that arises from the underlying assumptions.

  19. An electrophysiological investigation of early effects of masked morphological priming

    PubMed Central

    Morris, Joanna; Grainger, Jonathan; Holcomb, Phillip J.

    2009-01-01

    This experiment examined event-related responses to targets preceded by semantically transparent morphologically related primes (e.g., farmer-farm), semantically opaque primes with an apparent morphological relation (cornercorn), and orthographically, but not morphologically, related primes (scandalscan) using the masked priming technique combined with a semantic categorisation task. In order to provide information about possible early effects of morphology we focused our analysis on the N250 ERP component. Priming effects for transparent and opaque items patterned together in the early phase of the N250 (200-250 ms), whereas the transparent and orthographic items patterned together in the latter phase of this component (250-300 ms). These results provide further evidence in support of the rapid extraction of morphemes from morphologically complex stimuli independently of the semantic relatedness of the whole and its parts. PMID:19779574

  20. Morphological Processing as We Know It: An Analytical Review of Morphological Effects in Visual Word Identification

    PubMed Central

    Amenta, Simona; Crepaldi, Davide

    2012-01-01

    The last 40 years have witnessed a growing interest in the mechanisms underlying the visual identification of complex words. A large amount of experimental data has been amassed, but although a growing number of studies are proposing explicit theoretical models for their data, no comprehensive theory has gained substantial agreement among scholars in the field. We believe that this is due, at least in part, to the presence of several controversial pieces of evidence in the literature and, consequently, to the lack of a well-defined set of experimental facts that any theory should be able to explain. With this review, we aim to delineate the state of the art in the research on the visual identification of complex words. By reviewing major empirical evidences in a number of different paradigms such as lexical decision, word naming, and masked and unmasked priming, we were able to identify a series of effects that we judge as reliable or that were consistently replicated in different experiments, along with some more controversial data, which we have tried to resolve and explain. We concentrated on behavioral and electrophysiological studies on inflected, derived, and compound words, so as to span over all types of complex words. The outcome of this work is an analytical summary of well-established facts on the most relevant morphological issues, such as regularity, morpheme position coding, family size, semantic transparency, morpheme frequency, suffix allomorphy, and productivity, morphological entropy, and morpho-orthographic parsing. In discussing this set of benchmark effects, we have drawn some methodological considerations on why contrasting evidence might have emerged, and have tried to delineate a target list for the construction of a new all-inclusive model of the visual identification of morphologically complex words. PMID:22807919

  1. Simulating the evolution of coastal morphology and stratigraphy with a new morphological-behaviour model (GEOMBEST)

    USGS Publications Warehouse

    Stolper, D.; List, J.H.; Thieler, E.R.

    2005-01-01

    A new morphological-behaviour model is used to simulate evolution of coastal morphology associated with cross-shore translations of the shoreface, barrier, and estuary. The model encapsulates qualitative principles drawn from established geological concepts that are parameterized to provide quantitative predictions of morphological change on geological time scales (order 10 3 years), as well as shorter time scales applicable for long-term coastal management (order 101 to 102 years). Changes in sea level, and sediment volume within the shoreface, barrier, and estuary, drive the model behaviour. Further parameters, defining substrate erodibility, sediment composition, and time-dependent shoreface response, constrain the evolution of the shoreface towards an equilibrium profile. Results from numerical experiments are presented for the low-gradient autochthonous setting of North Carolina and the steep allochthonous setting of the Washington shelf. Simulations in the Currituck region of North Carolina examined the influence of sediment supply, substrate composition, and substrate erodibility on barrier transgression. Results demonstrate that the presence of a lithified substrate reduces the rate of barrier transgression compared to scenarios where an erodible, sand-rich substrate exists. Simulations of the Washington coast, 20 km north of the Columbia River, confirmed that the model can reproduce complex stratigraphy involving regressive and transgressive phases of coastal evolution. Results suggest that the first major addition of sediment to the shelf occurred around 12 900 years ago and resulted from the rapid addition of sediment volume from the Columbia River attributed to the Missoula floods. This was followed by a period where little or no sediment was added (12 400-9100 BP) and a third period when most sediment was added to the shelf (9100 BP to present) from the Columbia River. Comparing results from each setting demonstrates an indirect control that substrate

  2. Constraints on the morphological evolution of marsupial shoulder girdles.

    PubMed

    Sears, Karen E

    2004-10-01

    Throughout their evolutionary histories, marsupial mammals have been taxonomically and morphologically less diverse than their sister taxa the placentals. Because of this, it has been proposed that the evolution of marsupials has been constrained by the functional requirements of their mode of reproduction. Marsupials give birth after short gestation times to immature neonates that immediately crawl, under the power of their precociously developed shoulder girdles, to the teat where they attach and complete their early development. Using a novel approach incorporating adult and embryological morphological data, this study is the first to both: (1) statistically support adult patterns of morphological divergence consistent with the constraint hypothesis, and (2) identify ontogenetic patterns of morphological change that demonstrate that the constraint was responsible, at least in part, for their formation. As predicted by the marsupial constraint, the shoulder girdles of adult marsupials are less diverse than those of adult placentals, and adult marsupial scapulae are less morphologically diverse than adult marsupial pelves. Furthermore, marsupials that complete an extensive crawl to the teat are restricted to a common pattern of ontogenetic scapular shape change, strongly supporting the hypothesis that the morphological development of the marsupial scapula has been limited evolutionarily by its obligate role in the crawl to the teat. Because this study establishes that ontogenetic and evolutionary morphological change is correlated within mammalian scapulae, it is probable that the marsupial constraint also restricted the morphological divergence of the scapula over evolutionary time by limiting ontogenetic change in the scapula. These findings, coupled with the importance of the shoulder girdle in mammalian locomotor specialization, support the conclusion that the low morphological diversity of marsupial forms over evolutionary time could be directly due to the

  3. Robust surface roughness indices and morphological interpretation

    NASA Astrophysics Data System (ADS)

    Trevisani, Sebastiano; Rocca, Michele

    2016-04-01

    Geostatistical-based image/surface texture indices based on variogram (Atkison and Lewis, 2000; Herzfeld and Higginson, 1996; Trevisani et al., 2012) and on its robust variant MAD (median absolute differences, Trevisani and Rocca, 2015) offer powerful tools for the analysis and interpretation of surface morphology (potentially not limited to solid earth). In particular, the proposed robust index (Trevisani and Rocca, 2015) with its implementation based on local kernels permits the derivation of a wide set of robust and customizable geomorphometric indices capable to outline specific aspects of surface texture. The stability of MAD in presence of signal noise and abrupt changes in spatial variability is well suited for the analysis of high-resolution digital terrain models. Moreover, the implementation of MAD by means of a pixel-centered perspective based on local kernels, with some analogies to the local binary pattern approach (Lucieer and Stein, 2005; Ojala et al., 2002), permits to create custom roughness indices capable to outline different aspects of surface roughness (Grohmann et al., 2011; Smith, 2015). In the proposed poster, some potentialities of the new indices in the context of geomorphometry and landscape analysis will be presented. At same time, challenges and future developments related to the proposed indices will be outlined. Atkinson, P.M., Lewis, P., 2000. Geostatistical classification for remote sensing: an introduction. Computers & Geosciences 26, 361-371. Grohmann, C.H., Smith, M.J., Riccomini, C., 2011. Multiscale Analysis of Topographic Surface Roughness in the Midland Valley, Scotland. IEEE Transactions on Geoscience and Remote Sensing 49, 1220-1213. Herzfeld, U.C., Higginson, C.A., 1996. Automated geostatistical seafloor classification - Principles, parameters, feature vectors, and discrimination criteria. Computers and Geosciences, 22 (1), pp. 35-52. Lucieer, A., Stein, A., 2005. Texture-based landform segmentation of LiDAR imagery

  4. Morphology and neurochemistry of rabbit iris innervation.

    PubMed

    He, Jiucheng; Bazan, Haydee E P

    2015-06-01

    The aim of this study was to map the entire nerve architecture and sensory neuropeptide content of the rabbit iris. Irises from New Zealand rabbits were stained with antibodies against neuronal-class βIII-tubulin, calcitonin gene-related peptide (CGRP) and substance P (SP), and whole-mount images were acquired to build a two-dimensional view of the iridal nerve architecture. After taking images in time-lapse mode, we observed thick nerves running in the iris stroma close to the anterior epithelia, forming four to five stromal nerve rings from the iris periphery to the pupillary margin and sub-branches that connected with each other, constituting the stromal nerve plexus. In the anterior side, fine divisions derivated from the stromal nerves, forming a nerve network-like structure to innervate the superficial anterior border layer, with the pupillary margin having the densest innervation. In the posterior side, the nerve bundles ran along with the pupil dilator muscle in a radial pattern. The morphology of the iris nerves on both sides changed with pupil size. To obtain the relative content of the neuropeptides in the iris, the specimens were double stained with βIII-tubulin and CGRP or SP antibodies. Relative nerve fiber densities for each fiber population were assessed quantitatively by computer-assisted analysis. On the anterior side, CGRP-positive nerve fibers constituted about 61%, while SP-positive nerves constitute about 30.5%, of the total nerve content, which was expressed as βIII tubulin-positive fibers. In addition, in the anterior stroma of the collarette region, there were non-neuronal cells that were positive for SP. On the posterior side, CGRP-positive nerve fibers were about 69% of total nerve content, while SP constituted only up to 20%. Similarly, in the trigeminal ganglia (TG), the number of CGRP-positive neurons significantly outnumbered those that were positive for SP. Also, all the SP-positive neurons were labeled with CGRP. This is the

  5. Process depending morphology and resulting physical properties of TPU

    NASA Astrophysics Data System (ADS)

    Frick, Achim; Spadaro, Marcel

    2015-12-01

    Thermoplastic polyurethane (TPU) is a rubber like material with outstanding properties, e.g. for seal applications. TPU basically provides high strength, low frictional behavior and excellent wear resistance. Though, due to segmented structure of TPU, which is composed of hard segments (HSs) and soft segments (SSs), physical properties depend strongly on the morphological arrangement of the phase separated HSs at a certain ratio of HSs to SSs. It is obvious that the TPU deforms differently depending on its bulk morphology. Basically, the morphology can either consist of HSs segregated into small domains, which are well dispersed in the SS matrix or of few strongly phase separated large size HS domains embedded in the SS matrix. The morphology development is hardly ruled by the melt processing conditions of the TPU. Depending on the morphology, TPU provides quite different physical properties with respect to strength, deformation behavior, thermal stability, creep resistance and tribological performance. The paper deals with the influence of important melt processing parameters, such as temperature, pressure and shear conditions, on the resulting physical properties tested by tensile and relaxation experiments. Furthermore the morphology is studied employing differential scanning calorimeter (DSC), transmission light microscopy (TLM), scanning electron beam microscopy (SEM) and transmission electron beam microscopy (TEM) investigations. Correlations between processing conditions and resulting TPU material properties are elaborated. Flow and shear simulations contribute to the understanding of thermal and flow induced morphology development.

  6. Evolutionary developmental genetics of fruit morphological variation within the Solanaceae.

    PubMed

    Wang, Li; Li, Jing; Zhao, Jing; He, Chaoying

    2015-01-01

    Morphological variations of fruits such as shape and size, and color are a result of adaptive evolution. The evolution of morphological novelties is particularly intriguing. An understanding of these evolutionary processes calls for the elucidation of the developmental and genetic mechanisms that result in particular fruit morphological characteristics, which determine seed dispersal. The genetic and developmental basis for fruit morphological variation was established at a microevolutionary time scale. Here, we summarize the progress on the evolutionary developmental genetics of fruit size, shape and color in the Solanaceae. Studies suggest that the recruitment of a pre-existing gene and subsequent modification of its interaction and regulatory networks are frequently involved in the evolution of morphological diversity. The basic mechanisms underlying changes in plant morphology are alterations in gene expression and/or gene function. We also deliberate on the future direction in evolutionary developmental genetics of fruit morphological variation such as fruit type. These studies will provide insights into plant developmental processes and will help to improve the productivity and fruit quality of crops.

  7. The reciprocal relations between morphological processes and reading.

    PubMed

    Kruk, Richard S; Bergman, Krista

    2013-01-01

    Reciprocal relations between emerging morphological processes and reading skills were examined in a longitudinal study tracking children from Grade 1 through Grade 3. The aim was to examine predictive relationships between productive morphological processing involving composing and decomposing of inflections and derivations, reading ability for pseudoword and word decoding, and word and passage reading comprehension after controlling for initial abilities in reading, morphological processing, phonological awareness, and vocabulary. Reciprocal influences were indicated by predictive relations among initial morphological processes and later reading abilities co-occurring with relationships between initial reading abilities and later morphological processes. Using multilevel modeling, decomposing and composing were found to predict emerging word decoding and word and passage comprehension but not pseudoword decoding. Reading comprehension predicted growth in decomposing. Subsequent regression analyses of model-estimated early linear growth in predictors and later linear growth in outcomes showed that early growth in morphological processes predicted later growth in word decoding and passage comprehension. Although reciprocal relations between emerging morphological processes and reading skills were observed, the different patterns on each side of the reciprocal "coin" indicated that the mechanisms underlying predictive influences are likely different but related to quality of lexical representations.

  8. Genetic Determinism vs. Phenotypic Plasticity in Protist Morphology.

    PubMed

    Mulot, Matthieu; Marcisz, Katarzyna; Grandgirard, Lara; Lara, Enrique; Kosakyan, Anush; Robroek, Bjorn J M; Lamentowicz, Mariusz; Payne, Richard J; Mitchell, Edward A D

    2017-02-23

    Untangling the relationships between morphology and phylogeny is key to building a reliable taxonomy, but is especially challenging for protists, where the existence of cryptic or pseudocryptic species makes finding relevant discriminant traits difficult. Here we use Hyalosphenia papilio (a testate amoeba) as a model species to investigate the contribution of phylogeny and phenotypic plasticity in its morphology. We study the response of H. papilio morphology (shape and pores number) to environmental variables in (i) a manipulative experiment with controlled conditions (water level), (ii) an observational study of a within-site natural ecological gradient (water level), and (iii) an observational study across 37 European peatlands (climate). We showed that H. papilio morphology is correlated to environmental conditions (climate and water depth) as well as geography, while no relationship between morphology and phylogeny was brought to light. The relative contribution of genetic inheritance and phenotypic plasticity in shaping morphology varies depending on the taxonomic group and the trait under consideration. Thus, our data call for a reassessment of taxonomy based on morphology alone. This clearly calls for a substantial increase in taxonomic research on these globally still under-studied organisms leading to a reassessment of estimates of global microbial eukaryotic diversity.

  9. Predation risk influences adaptive morphological variation in fish populations.

    PubMed

    Eklöv, Peter; Svanbäck, Richard

    2006-03-01

    Predators can cause a shift in both density and frequency of a prey phenotype that may lead to phenotypic divergence through natural selection. What is less investigated is that predators have a variety of indirect effects on prey that could potentially have large evolutionary responses. We conducted a pond experiment to test whether differences in predation risk in different habitats caused shifts in behavior of prey that, in turn, would affect their morphology. We also tested whether the experimental data could explain the morphological variation of perch in the natural environment. In the experiment, predators caused the prey fish to shift to the habitat with the lower predation risk. The prey specialized on habitat-specific resources, and there was a strong correlation between diet of the prey fish and morphological variation, suggesting that resource specialization ultimately affected the morphology. The lack of differences in competition and mortality suggest that the morphological variation among prey was induced by differences in predation risk among habitats. The field study demonstrated that there are differences in growth related to morphology of perch in two different habitats. Thus, a trade-off between foraging and predator avoidance could be responsible for adaptive morphological variation of young perch.

  10. Process depending morphology and resulting physical properties of TPU

    SciTech Connect

    Frick, Achim Spadaro, Marcel

    2015-12-17

    Thermoplastic polyurethane (TPU) is a rubber like material with outstanding properties, e.g. for seal applications. TPU basically provides high strength, low frictional behavior and excellent wear resistance. Though, due to segmented structure of TPU, which is composed of hard segments (HSs) and soft segments (SSs), physical properties depend strongly on the morphological arrangement of the phase separated HSs at a certain ratio of HSs to SSs. It is obvious that the TPU deforms differently depending on its bulk morphology. Basically, the morphology can either consist of HSs segregated into small domains, which are well dispersed in the SS matrix or of few strongly phase separated large size HS domains embedded in the SS matrix. The morphology development is hardly ruled by the melt processing conditions of the TPU. Depending on the morphology, TPU provides quite different physical properties with respect to strength, deformation behavior, thermal stability, creep resistance and tribological performance. The paper deals with the influence of important melt processing parameters, such as temperature, pressure and shear conditions, on the resulting physical properties tested by tensile and relaxation experiments. Furthermore the morphology is studied employing differential scanning calorimeter (DSC), transmission light microscopy (TLM), scanning electron beam microscopy (SEM) and transmission electron beam microscopy (TEM) investigations. Correlations between processing conditions and resulting TPU material properties are elaborated. Flow and shear simulations contribute to the understanding of thermal and flow induced morphology development.

  11. Ultrastructure of Dendritic Spines: Correlation Between Synaptic and Spine Morphologies

    PubMed Central

    Arellano, Jon I.; Benavides-Piccione, Ruth; DeFelipe, Javier; Yuste, Rafael

    2007-01-01

    Dendritic spines are critical elements of cortical circuits, since they establish most excitatory synapses. Recent studies have reported correlations between morphological and functional parameters of spines. Specifically, the spine head volume is correlated with the area of the postsynaptic density (PSD), the number of postsynaptic receptors and the ready-releasable pool of transmitter, whereas the length of the spine neck is proportional to the degree of biochemical and electrical isolation of the spine from its parent dendrite. Therefore, the morphology of a spine could determine its synaptic strength and learning rules. To better understand the natural variability of neocortical spine morphologies, we used a combination of gold-toned Golgi impregnations and serial thin-section electron microscopy and performed three-dimensional reconstructions of spines from layer 2/3 pyramidal cells from mouse visual cortex. We characterized the structure and synaptic features of 144 completed reconstructed spines, and analyzed their morphologies according to their positions. For all morphological parameters analyzed, spines exhibited a continuum of variability, without clearly distinguishable subtypes of spines or clear dependence of their morphologies on their distance to the soma. On average, the spine head volume was correlated strongly with PSD area and weakly with neck diameter, but not with neck length. The large morphological diversity suggests an equally large variability of synaptic strength and learning rules. PMID:18982124

  12. Habitat type and ambient temperature contribute to bill morphology.

    PubMed

    Luther, David; Greenberg, Russell

    2014-03-01

    Avian bills are iconic structures for the study of ecology and evolution, with hypotheses about the morphological structure of bills dating back to Darwin. Several ecological and physiological hypotheses have been developed to explain the evolution of the morphology of bill shape. Here, we test some of these hypotheses such as the role of habitat, ambient temperature, body size, intraspecific competition, and ecological release on the evolution of bill morphology. Bill morphology and tarsus length were measured from museum specimens of yellow warblers, and grouped by habitat type, sex, and subspecies. We calculated the mean maximum daily temperature for the month of July, the hottest month for breeding specimens at each collecting location. Analysis of covariance models predicted total bill surface area as a function of sex, habitat type, body size, and temperature, and model selection techniques were used to select the best model. Habitat, mangrove forests compared with inland habitats, and climate had the largest effects on bill size. Coastal wetland habitats and island populations of yellow warblers had similar bill morphology, both of which are larger than mainland inland populations. Temperate but not tropical subspecies exhibited sexual dimorphism in bill morphology. Overall, this study provides evidence that multiple environmental factors, such as temperature and habitat, contribute to the evolution of bill morphology.

  13. Freehand three-dimensional ultrasound to assess semitendinosus muscle morphology.

    PubMed

    Haberfehlner, Helga; Maas, Huub; Harlaar, Jaap; Becher, Jules G; Buizer, Annemieke I; Jaspers, Richard T

    2016-10-01

    In several neurological disorders and muscle injuries, morphological changes of the m. semitendinosus (ST) are presumed to contribute to movement limitations around the knee. Freehand three-dimensional (3D) ultrasound (US), using position tracking of two-dimensional US images to reconstruct a 3D voxel array, can be used to assess muscle morphology in vivo. The aims of this study were: (i) to introduce a newly developed 3D US protocol for ST; and (ii) provide a first comparison of morphological characteristics determined by 3D US with those measured on dissected cadaveric muscles. Morphological characteristics of ST (e.g. muscle belly length, tendon length, fascicle length and whole muscle volume, and volumes of both compartments) were assessed in six cadavers using a 3D US protocol. Subsequently, ST muscles were removed from the body to measure the same morphological characteristics. Mean differences between morphological characteristics measured by 3D US and after dissection were smaller than 10%. Intra-class correlation coefficients (ICCs) were higher than 0.75 for all variables except for the lengths of proximal fascicles (ICC = 0.58). Measurement of the volume of proximal compartment by 3D US was not feasible, due to low US image quality proximally. We conclude that the presented 3D US protocol allows for reasonably accurate measurements of key morphological characteristics of ST muscle.

  14. Evolutionary developmental genetics of fruit morphological variation within the Solanaceae

    PubMed Central

    Wang, Li; Li, Jing; Zhao, Jing; He, Chaoying

    2015-01-01

    Morphological variations of fruits such as shape and size, and color are a result of adaptive evolution. The evolution of morphological novelties is particularly intriguing. An understanding of these evolutionary processes calls for the elucidation of the developmental and genetic mechanisms that result in particular fruit morphological characteristics, which determine seed dispersal. The genetic and developmental basis for fruit morphological variation was established at a microevolutionary time scale. Here, we summarize the progress on the evolutionary developmental genetics of fruit size, shape and color in the Solanaceae. Studies suggest that the recruitment of a pre-existing gene and subsequent modification of its interaction and regulatory networks are frequently involved in the evolution of morphological diversity. The basic mechanisms underlying changes in plant morphology are alterations in gene expression and/or gene function. We also deliberate on the future direction in evolutionary developmental genetics of fruit morphological variation such as fruit type. These studies will provide insights into plant developmental processes and will help to improve the productivity and fruit quality of crops. PMID:25918515

  15. The effect of parity on morphological evolution among phrynosomatid lizards.

    PubMed

    Oufiero, C E; Gartner, G E A

    2014-11-01

    The shift from egg laying to live-bearing is one of the most well-studied transitions in evolutionary biology. Few studies, however, have assessed the effect of this transition on morphological evolution. Here, we evaluated the effect of reproductive mode on the morphological evolution of 10 traits, among 108 species of phrynosomatid lizards. We assess whether the requirement for passing shelled eggs through the pelvic girdle has led to morphological constraints in oviparous species and whether long gestation times in viviparous species have led to constraints in locomotor morphology. We fit models to the data that vary both in their tempo (strength and rate of selection) and mode of evolution (Brownian or Ornstein-Uhlenbeck) and estimates of trait optima. We found that most traits are best fit by a generalized multipeak OU model, suggesting differing trait optima for viviparous vs. oviparous species. Additionally, rates (σ(2) ) of both pelvic girdle and forelimb trait evolution varied with parity; viviparous species had higher rates. Hindlimb traits, however, exhibited no difference in σ(2) between parity modes. In a functional context, our results suggest that the passage of shelled eggs constrains the morphology of the pelvic girdle, but we found no evidence of morphological constraint of the locomotor apparatus in viviparous species. Our results are consistent with recent lineage diversification analyses, leading to the conclusion that transitions to viviparity increase both lineage and morphological diversification.

  16. Laser cooling atoms to indistinguishability: Atomic Hong-Ou-Mandel interference and entanglement through spin exchange

    NASA Astrophysics Data System (ADS)

    Kaufman, Adam

    2016-05-01

    Motional control of neutral atoms has a rich history and increasingly interest has turned to single-atom control. In my thesis work, we created a platform to individually prepare single bosonic atoms in highly pure quantum states, by developing methods to laser cool single atoms to the vibrational ground state of optical tweezer traps. Applying this toolset, we observe the atomic Hong-Ou-Mandel effect when we arrange for atom tunneling to play the role of a balanced beam splitter between two optical tweezers. In another experiment, we utilize spin exchange to create entanglement, which we then verify after spatially separating the atoms to observe their non-local correlations. Merging these results with our recent demonstration of deterministic loading of atomic arrays, our results establish the concept of quantum gas assembly, which could be applied to a variety of systems ranging from the production of single dipolar molecules to the assembly of low-entropy arrays of atoms.

  17. The spectroscopic indistinguishability of red giant branch and red clump stars

    NASA Astrophysics Data System (ADS)

    Masseron, T.; Hawkins, K.

    2017-01-01

    Context. Stellar spectroscopy provides useful information on the physical properties of stars such as effective temperature, metallicity and surface gravity. However, those photospheric characteristics are often hampered by systematic uncertainties. The joint spectro-sismo project (APOGEE+Kepler, aka APOKASC) of field red giants has revealed a puzzling offset between the surface gravities (log g) determined spectroscopically and those determined using asteroseismology, which is largely dependent on the stellar evolutionary status. Aims: Therefore, in this letter, we aim to shed light on the spectroscopic source of the offset. Methods: We used the APOKASC sample to analyse the dependencies of the log g discrepancy as a function of stellar mass and stellar evolutionary status. We discuss and study the impact of some neglected abundances on spectral analysis of red giants, such as He and carbon isotopic ratio. Results: We first show that, for stars at the bottom of the red giant branch where the first dredge-up had occurred, the discrepancy between spectroscopic log g and asteroseismic log g depends on stellar mass. This seems to indicate that the log g discrepancy is related to CN cycling. Among the CN-cycled elements, we demonstrate that the carbon isotopic ratio (12C /13C) has the largest impact on stellar spectrum. In parallel, we observe that this log g discrepancy shows a similar trend as the 12C /13C ratios as expected by stellar evolution theory. Although we did not detect a direct spectroscopic signature of 13C, other corroborating evidences suggest that the discrepancy in log g is tightly correlated to the production of 13C in red giants. Moreover, by running the data-driven algorithm (the Cannon) on a synthetic grid trained on the APOGEE data, we try to evaluate more quantitatively the impact of various 12C /13C ratios. Conclusions: While we have demonstrated that 13C indeed impacts all parameters, the size of the impact is smaller than the observed offset in log g. If further tests confirm that 13C is not the main element responsible of the log g problem, the number of spectroscopic effects remaining to be investigated is now relatively limited (if any).

  18. Indistinguishability of photon pair in a periodically poled KTiOPO4

    NASA Astrophysics Data System (ADS)

    Lee, Hee Jung; Kim, Heonoh; Lee, Sang Min; Moon, Han Seb

    2015-12-01

    We report the two-photon interference properties of a photon pair generated in a type-II collinear periodically poled KTiOPO4 (PPKTP) crystal pumped by a 406-nm diode laser capable of producing a single or dual longitudinal mode (LM). When the Hong-Ou-Mandel (HOM) interference signals in the PPKTP crystal pumped by a dual-mode diode laser were investigated at various crystal temperatures, it was found that the maximum visibility of the HOM interference signal depends on the relative strength of the dual LMs of the pump laser. The HOM interference pattern was numerically calculated considering the dual LM components of the pump laser diode and the crystal temperature, and was found to be in good agreement with the experimental results.

  19. Cyclomaltodextrinase, neopullulanase, and maltogenic amylase are nearly indistinguishable from each other.

    PubMed

    Lee, Hee-Seob; Kim, Min-Sung; Cho, Hyun-Soo; Kim, Jung-In; Kim, Tae-Jip; Choi, Ji-Hye; Park, Cheonseok; Lee, Heung-Soo; Oh, Byung-Ha; Park, Kwan-Hwa

    2002-06-14

    Over 20 enzymes denoted as cyclomaltodextrinase, maltogenic amylase, or neopullulanase that share 40-86% sequence identity with each other are found in public data bases. These enzymes are distinguished from typical alpha-amylases by containing a novel N-terminal domain and exhibiting preferential substrate specificities for cyclomaltodextrins (CDs) over starch. In this research field, a great deal of confusion exists regarding the features distinguishing the three groups of enzymes from one another. Although a different enzyme code has been assigned to each of the three different enzyme names, even a single differentiating enzymatic property has not been documented in the literature. On the other hand, an outstanding question related to this issue concerns the structural basis for the preference of these enzymes for CDs. To clarify the confusion and to address this question, we have determined the structures of two enzymes, one from alkalophilic Bacillus sp. I-5 and named cyclomaltodextrinase and the other from a Thermus species and named maltogenic amylase. The structure of the Bacillus enzyme reveals a dodecameric assembly composed of six copies of the dimer, which is the structural and functional unit of the Thermus enzyme and an enzyme named neopullulanase. The structure of the Thermus enzyme in complex with beta-CD led to the conclusion that Trp47, a well conserved N-terminal domain residue, contributes greatly to the preference for beta-CD. The common dimer formation through the novel N-terminal domain, which contributes to the preference for CDs by lining the active-site cavity, convincingly indicates that the three groups of enzymes are not different enough to preserve the different names and enzyme codes.

  20. New Results in Fuzzy Clustering Based on the Concept of Indistinguishability Relation

    DTIC Science & Technology

    1984-01-01

    factor analysis , principal components, etc.). We start giving some definitions and theorems whose proofs are omitted because of space reasons (See...To appear in H.J. Skala et al. (Eds.): Aspects of Vagueness. Reidel. Valverde, L. (1982). Contribucio a l’estudi dels models matematics per rogiques

  1. Helicobacter gastritis induces changes in the oxyntic mucosa indistinguishable from the effects of proton pump inhibitors.

    PubMed

    Kumar, Kirthi R; Iqbal, Ramiz; Coss, Elizabeth; Park, Christina; Cryer, Byron; Genta, Robert M

    2013-12-01

    A causal relationship between oxyntic glands dilatation with protruding parietal cells, referred to as proton pump inhibitor (PPI) effects, and PPI use has been suspected but not established. We designed this study to evaluate the association between these changes and the use of PPIs and histamine2-receptor blockers (H2-blockers). We obtained five Sydney System-compliant biopsy specimens from patients recruited into a therapeutic trial for H. pylori. Medication history with details on PPI and H2-blockers use was collected. Two blinded pathologists graded gastritis and the intensity of putative PPI effects using a 0 to 3 scale. PPI and H2-blocker use was then disclosed and the accuracy of pathologists' assessment was analyzed. There were 138 H. pylori-negative and 104 positive patients. In H. pylori-negative patients the histologic assessment for PPI use had 77.5% sensitivity and 51.8% specificity, with a positive predictive value of 86.9% and a negative predictive value of 35.9%. In H. pylori-positive patients, sensitivity was 74.1% and specificity 26.1%. Positive and negative predictive values were 55.8% and 44.4%, respectively. Neither glandular dilatations nor parietal cell protrusions related to H2-blocker use. We conclude that these changes are associated with PPI use only in H. pylori-negative subjects. In H. pylori gastritis, so-called PPI-effects were equally prevalent in PPI-users and non-users, indicating that other factors are involved in the induction of oxyntic cell hyperplasia. We suggest that comments regarding the supposed evidence of PPI use are too often wrong to be useful and should be avoided in the diagnosis of gastric biopsy specimens.

  2. Multiscale Morphological Filtering for Analysis of Noisy and Complex Images

    NASA Technical Reports Server (NTRS)

    Kher, A.; Mitra, S.

    1993-01-01

    Images acquired with passive sensing techniques suffer from illumination variations and poor local contrasts that create major difficulties in interpretation and identification tasks. On the other hand, images acquired with active sensing techniques based on monochromatic illumination are degraded with speckle noise. Mathematical morphology offers elegant techniques to handle a wide range of image degradation problems. Unlike linear filters, morphological filters do not blur the edges and hence maintain higher image resolution. Their rich mathematical framework facilitates the design and analysis of these filters as well as their hardware implementation. Morphological filters are easier to implement and are more cost effective and efficient than several conventional linear filters. Morphological filters to remove speckle noise while maintaining high resolution and preserving thin image regions that are particularly vulnerable to speckle noise were developed and applied to SAR imagery. These filters used combination of linear (one-dimensional) structuring elements in different (typically four) orientations. Although this approach preserves more details than the simple morphological filters using two-dimensional structuring elements, the limited orientations of one-dimensional elements approximate the fine details of the region boundaries. A more robust filter designed recently overcomes the limitation of the fixed orientations. This filter uses a combination of concave and convex structuring elements. Morphological operators are also useful in extracting features from visible and infrared imagery. A multiresolution image pyramid obtained with successive filtering and a subsampling process aids in the removal of the illumination variations and enhances local contrasts. A morphology-based interpolation scheme was also introduced to reduce intensity discontinuities created in any morphological filtering task. The generality of morphological filtering techniques in

  3. Morphological evolution of growing crystals - A Monte Carlo simulation

    NASA Technical Reports Server (NTRS)

    Xiao, Rong-Fu; Alexander, J. Iwan D.; Rosenberger, Franz

    1988-01-01

    The combined effects of nutrient diffusion and surface kinetics on the crystal morphology were investigated using a Monte Carlo model to simulate the evolving morphology of a crystal growing from a two-component gaseous nutrient phase. The model combines nutrient diffusion, based on a modified diffusion-limited aggregation process, with anisotropic surface-attachment kinetics and surface diffusion. A variety of conditions, ranging from kinetic-controlled to diffusion-controlled growth, were examined. Successive transitions from compact faceted (dominant surface kinetics) to open dendritic morphologies (dominant volume diffusion) were obtained.

  4. Dumb bell shaped morphology of liver: an autopsy case report.

    PubMed

    Jagadish Rao, P P; Murlimanju, B V; Menezes, R G

    2013-01-01

    Medicolegal autopsy on the dead body of an elderly female revealed that the liver was having some unusual shape. The left lobe of liver was bifid, having dumb bell type morphology. Also there were some furrows which were observed over the anterior surface of the liver. This type of morphological variant has not been reported hitherto. The clinicians should be aware of developmental morphological anomalies like in this case, as they might cause confusion during the procedures like biopsy, transplantation and lobectomies. We believe that this case report is important for the clinicians who are involved in the diagnosis and management of hepatic diseases. The knowledge is also enlightening for morphologists and embryologists.

  5. Test-retest reliability of brain morphology estimates.

    PubMed

    Madan, Christopher R; Kensinger, Elizabeth A

    2017-01-05

    Metrics of brain morphology are increasingly being used to examine inter-individual differences, making it important to evaluate the reliability of these structural measures. Here we used two open-access datasets to assess the intersession reliability of three cortical measures (thickness, gyrification, and fractal dimensionality) and two subcortical measures (volume and fractal dimensionality). Reliability was generally good, particularly with the gyrification and fractal dimensionality measures. One dataset used a sequence previously optimized for brain morphology analyses and had particularly high reliability. Examining the reliability of morphological measures is critical before the measures can be validly used to investigate inter-individual differences.

  6. The Interplay of Dengue Virus Morphological Diversity and Human Antibodies.

    PubMed

    Lok, Shee-Mei

    2016-04-01

    Dengue virus (DENV) infects ∼400 million people annually, and there is no available vaccine or therapeutics. It is not clear why candidate vaccines provide only modest protection. In addition to the presence of four different dengue serotypes, there is also structural heterogeneity in DENV infectious particles, even within a strain. This severely complicates the development of vaccines and therapeutics. The currently known different morphologies of DENV are: immature, partially mature, compact mature, and expanded mature forms of the virus. In this review I describe these forms of the virus, their infectivity, and how antibodies could recognize these morphologies. I also discuss possible vaccine and antibody therapeutic formulations to protect against all morphologies.

  7. Analysis of the dental morphology of Plio-Pleistocene hominids. IV. Mandibular postcanine root morphology.

    PubMed Central

    Wood, B A; Abbott, S A; Uytterschaut, H

    1988-01-01

    The subocclusal morphology of 168 permanent mandibular premolars (N = 77) and molars (N = 91) of Plio-Pleistocene hominids has been investigated. The taxonomic allocation of the teeth, which represent at least 46 individuals, was based on nondental evidence. Specimens were allocated to one of two major taxonomic categories, (EAFROB or EAFHOM), East African Homo erectus (EAFHER), or their taxonomic affinity was regarded as 'unknown' (N = 17). Information about the root system was derived from radiography and direct observation. Morphometric data were in the form of nine linear and two angular measurements based on eighteen reference points. Root form was also assessed using a scheme which recognised four classes of root morphology. Data were compared using both univariate and multivariate techniques, including Principal Component and Canonical Variate analysis. Posterior probabilities derived from the latter were used (in a two-taxon design model) to assess the affinities of the 'unknown' specimens. The variation in hominid mandibular premolar root form was interpreted as two morphoclines, based on the presumed primitive condition of the P3 (with mesiobuccal and distal roots, 2R: MB and D) and P4 (with mesial and distal root, 2R: M and D) root systems. One trend apparently leads towards root reduction (i.e. P3 = 1 R; P4 = 1 R), and the other to root elaboration (i.e. P3 and P4 = 2R: M and D). The extreme form of the latter is the 'molarisation' of the premolar roots seen in EAFROB. Despite major differences in root form there was relatively little taxonomic variation in root metrics, except for a more robust distal root system in EAFROB. Molar root form showed little interspecific variation except for M2 in which the roots in EAFROB were larger and more robust, with differences in root height being greater for the distal than for the mesial roots. Root form and metrics enable four of the 'unknown' specimens (KMN-ER 819, 1482, 1483 and 1801) to be tentatively

  8. Analysis of the dental morphology of Plio-Pleistocene hominids. IV. Mandibular postcanine root morphology.

    PubMed

    Wood, B A; Abbott, S A; Uytterschaut, H

    1988-02-01

    The subocclusal morphology of 168 permanent mandibular premolars (N = 77) and molars (N = 91) of Plio-Pleistocene hominids has been investigated. The taxonomic allocation of the teeth, which represent at least 46 individuals, was based on nondental evidence. Specimens were allocated to one of two major taxonomic categories, (EAFROB or EAFHOM), East African Homo erectus (EAFHER), or their taxonomic affinity was regarded as 'unknown' (N = 17). Information about the root system was derived from radiography and direct observation. Morphometric data were in the form of nine linear and two angular measurements based on eighteen reference points. Root form was also assessed using a scheme which recognised four classes of root morphology. Data were compared using both univariate and multivariate techniques, including Principal Component and Canonical Variate analysis. Posterior probabilities derived from the latter were used (in a two-taxon design model) to assess the affinities of the 'unknown' specimens. The variation in hominid mandibular premolar root form was interpreted as two morphoclines, based on the presumed primitive condition of the P3 (with mesiobuccal and distal roots, 2R: MB and D) and P4 (with mesial and distal root, 2R: M and D) root systems. One trend apparently leads towards root reduction (i.e. P3 = 1 R; P4 = 1 R), and the other to root elaboration (i.e. P3 and P4 = 2R: M and D). The extreme form of the latter is the 'molarisation' of the premolar roots seen in EAFROB. Despite major differences in root form there was relatively little taxonomic variation in root metrics, except for a more robust distal root system in EAFROB. Molar root form showed little interspecific variation except for M2 in which the roots in EAFROB were larger and more robust, with differences in root height being greater for the distal than for the mesial roots. Root form and metrics enable four of the 'unknown' specimens (KMN-ER 819, 1482, 1483 and 1801) to be tentatively

  9. Morphology, temperature, and eruption dynamics at Pele

    NASA Astrophysics Data System (ADS)

    Howell, Robert R.; Lopes, Rosaly M. C.

    2011-06-01

    The Pele region of Io has been the site of vigorous volcanic activity from the time of the first Voyager I observations in 1979 up through the final Galileo ones in 2001. There is high-temperature thermal emission from a visibly dark area that is thought to be a rapidly overturning lava lake, and is also the source of a large sulfur-rich plume. We present a new analysis of Voyager I visible wavelength images, and Galileo Solid State Imager (SSI) and Near Infrared Mapping Spectrometer (NIMS) thermal emission observations which better define the morphology of the region and the intensity of the emission. The observations show remarkable correlations between the locations of the emission and the features seen in the Voyager images, which provide insight into eruption mechanisms and constrain the longevity of the activity. We also analyze an additional wavelength channel of NIMS data (1.87 μm) which paradoxically, because of reduced sensitivity, allows us to estimate temperatures at the peak locations of emission. Measurements of eruption temperatures on Io are crucial because they provide our best clues to the composition of the magma. High color temperatures indicative of ultramafic composition have been reported for the Pillan hot spot and possibly for Pele, although recent work has called into question the requirement for magma temperatures above those expected for ordinary basalts. Our new analysis of the Pele emission near the peak of the hot spot shows color temperatures near the upper end of the basalt range during the I27 and I32 encounters. In order to analyze the observed color temperatures we also present an analytical model for the thermal emission from fire-fountains, which should prove generally useful for analyzing similar data. This is a modification of the lava flow emission model presented in Howell (Howell, R.R. [1997]. Icarus 127, 394-407), adapted to the fire-fountain cooling curves first discussed in Keszthelyi et al. (Keszthelyi, L., Jaeger, W

  10. Morphological evolution in the variable resin-producing Detarieae (Fabaceae): do morphological characters retain a phylogenetic signal?

    PubMed Central

    Fougère-Danezan, Marie; Herendeen, Patrick S.; Maumont, Stéphan; Bruneau, Anne

    2010-01-01

    Background and Aims Previous molecular phylogenetic studies disagree with the informal generic-level taxonomic groups based on morphology. In this study morphological characters in the caesalpinioid clade Detarieae are evaluated within a phylogenetic framework as a means of better understanding phylogenetic relationships and morphological evolution. Methods Morphological characters were observed and scored for representative species of Detarieae focusing on the resin-producing genera. Phylogenetic analyses were carried out with morphological characters alone and then combined with DNA sequences. Key Results Despite a high level of homoplasy, morphological data support several clades corresponding to those recovered in molecular phylogenetic analyses. The more strongly supported clades are each defined by at least one morphological synapomorphy. Several characters (e.g. apetaly) previously used to define informal generic groups evolved several times independently, leading to the differences observed with the molecular phylogenetic analyses. Although floral evolution is complex in Detarieae some patterns are recovered. Conclusions New informal taxonomic groupings are proposed based on the present findings. Floral evolution in the diverse Detarieae clade is characterized by a repeated tendency toward zygomorphy through the reduction of lateral petals and toward complete loss of petals. PMID:19939978

  11. Influence of Copolymer Composition on Morphology Development in Blends

    NASA Astrophysics Data System (ADS)

    Krishanmoorthy, Jayaraman

    2005-03-01

    Blends involving a crystallizable polyester [poly(hexamethylene adipate) (PHMA)] with an amorphous polyether has been studied. These systems have hydroxyl end groups which can react with diisocyanate in the presence of nucleophilic catalysts. These functionalized (isocyanate-terminated) polymer blends form the fundamental structure of polyurethanes. These prepolymers can then be cured at a later stage due to ambient water molecules. Thus the migration of water molecules through the morphology formed needs to be understood well. The morphology development (i.e. phase separation occurring concurrently with crystallization) of nascent polymer blends has been characterized. The morphology of functionalized polymers exhibit very different kinetics due to the presence of the small amount of copolymers formed. The ultimate morphology formed can be ``tuned'' by varying blend composition and crystallization conditions. The structures of prepolymers will be reported. The presence of this copolymer can significantly alter the structural transformation in either binary or ternary blends.

  12. Skeletal maturation analysis by morphological evaluation of the cervical vertebrae.

    PubMed

    Santos, Eduardo César Almada; Bertoz, Francisco Antônio; Arantes, Flávia de Moraes; Reis, Patrícia Maria Pizzo; de Bertoz, André Pinheiro Magalhães

    2006-01-01

    The determination of skeletal maturation by morphological evaluation of the cervical vertebrae was evaluated in a 100 cephalograms. The analysis showed that this method was reproducible for assessing the individual's growth curve.

  13. Non-native three-dimensional block copolymer morphologies

    PubMed Central

    Rahman, Atikur; Majewski, Pawel W.; Doerk, Gregory; Black, Charles T.; Yager, Kevin G.

    2016-01-01

    Self-assembly is a powerful paradigm, wherein molecules spontaneously form ordered phases exhibiting well-defined nanoscale periodicity and shapes. However, the inherent energy-minimization aspect of self-assembly yields a very limited set of morphologies, such as lamellae or hexagonally packed cylinders. Here, we show how soft self-assembling materials—block copolymer thin films—can be manipulated to form a diverse library of previously unreported morphologies. In this iterative assembly process, each polymer layer acts as both a structural component of the final morphology and a template for directing the order of subsequent layers. Specifically, block copolymer films are immobilized on surfaces, and template successive layers through subtle surface topography. This strategy generates an enormous variety of three-dimensional morphologies that are absent in the native block copolymer phase diagram. PMID:28004774

  14. Non-native three-dimensional block copolymer morphologies

    DOE PAGES

    Rahman, Atikur; Majewski, Pawel W.; Doerk, Gregory; ...

    2016-12-22

    Self-assembly is a powerful paradigm, wherein molecules spontaneously form ordered phases exhibiting well-defined nanoscale periodicity and shapes. However, the inherent energy-minimization aspect of self-assembly yields a very limited set of morphologies, such as lamellae or hexagonally packed cylinders. Here, we show how soft self-assembling materials—block copolymer thin films—can be manipulated to form a diverse library of previously unreported morphologies. In this iterative assembly process, each polymer layer acts as both a structural component of the final morphology and a template for directing the order of subsequent layers. Specifically, block copolymer films are immobilized on surfaces, and template successive layers throughmore » subtle surface topography. As a result, this strategy generates an enormous variety of three-dimensional morphologies that are absent in the native block copolymer phase diagram.« less

  15. Non-native three-dimensional block copolymer morphologies

    SciTech Connect

    Rahman, Atikur; Majewski, Pawel W.; Doerk, Gregory; Black, Charles T.; Yager, Kevin G.

    2016-12-22

    Self-assembly is a powerful paradigm, wherein molecules spontaneously form ordered phases exhibiting well-defined nanoscale periodicity and shapes. However, the inherent energy-minimization aspect of self-assembly yields a very limited set of morphologies, such as lamellae or hexagonally packed cylinders. Here, we show how soft self-assembling materials—block copolymer thin films—can be manipulated to form a diverse library of previously unreported morphologies. In this iterative assembly process, each polymer layer acts as both a structural component of the final morphology and a template for directing the order of subsequent layers. Specifically, block copolymer films are immobilized on surfaces, and template successive layers through subtle surface topography. As a result, this strategy generates an enormous variety of three-dimensional morphologies that are absent in the native block copolymer phase diagram.

  16. Morphology-Controlled Synthesis of Organometal Halide Perovskite Inverse Opals.

    PubMed

    Chen, Kun; Tüysüz, Harun

    2015-11-09

    The booming development of organometal halide perovskites in recent years has prompted the exploration of morphology-control strategies to improve their performance in photovoltaic, photonic, and optoelectronic applications. However, the preparation of organometal halide perovskites with high hierarchical architecture is still highly challenging and a general morphology-control method for various organometal halide perovskites has not been achieved. A mild and scalable method to prepare organometal halide perovskites in inverse opal morphology is presented that uses a polystyrene-based artificial opal as hard template. Our method is flexible and compatible with different halides and organic ammonium compositions. Thus, the perovskite inverse opal maintains the advantage of straightforward structure and band gap engineering. Furthermore, optoelectronic investigations reveal that morphology exerted influence on the conducting nature of organometal halide perovskites.

  17. Morphological type correlation between nearest neighbor pairs of galaxies

    NASA Astrophysics Data System (ADS)

    Yamagata, Tomohiko

    1990-11-01

    Although the morphological type of galaxies is one of the most fundamental properties of galaxies, its origin and evolutionary processes, if any, are not yet fully understood. It has been established that the galaxy morphology strongly depends on the environment in which the galaxy resides (e.g., Dressler 1980). Galaxy pairs correspond to the smallest scales of galaxy clustering and may provide important clues to how the environment influences the formation and evolution of galaxies. Several investigators pointed out that there is a tendency for pair galaxies to have similar morphological types (Karachentsev and Karachentseva 1974, Page 1975, Noerdlinger 1979). Here, researchers analyze morphological type correlation for 18,364 nearest neighbor pairs of galaxies identified in the magnetic tape version of the Center for Astrophysics Redshift Catalogue.

  18. Flight stability analysis under changes in insect morphology

    NASA Astrophysics Data System (ADS)

    Noest, Robert; Wang, Z. Jane

    2015-11-01

    Insect have an amazing ability to control their flight, being able to perform both fast aerial maneuvers and stable hovering. The insect's neural system has developed various mechanism by which it can control these flying feats, but we expect that insect morphology is equally important in facilitating the aerial control. We perform a computational study using a quasi-steady instantaneous flapping flight model which allows us to freely adapt the insect's morphological parameters. We picked a fruit fly as the basis for the body shape and wing motion, and study the effect of changes to the morphology for a range of wing stroke amplitudes. In each case we determine the periodic flight mode, with the period equal to a single wing beat, and do a Floquet stability analysis of the flight. To interpret our results we will compare the changed morphology to related insects. We discuss the implications of the insects location on the stability diagram.

  19. The Parsec-Scale Morphology of Southern GPS Sources

    NASA Astrophysics Data System (ADS)

    Edwards, P. G.; Tingay, S. J.

    2016-12-01

    Multi-frequency, multi-epoch ATCA observations of a sample of AGN resulted in the identification of nine new candidate Giga-hertz Peaked Spectrum sources. Here, we present Long Baseline Array observations at 4.8 GHz of the four candidates with no previously published VLBI image, and consider these together with previously published VLBI images of the other five sources. We find core-jet or compact double morphologies dominate, with further observations required to distinguish between these two possibilities for some sources. One of the nine candidates, PKS 1831-711, displays appreciable variability, suggesting its GPS spectrum is more ephemeral in nature. We focus in particular on the apparent relationship between a narrow spectral width and `compact double' parsec-scale morphology, finding further examples, but also exceptions to this trend. An examination of the VLBI morphologies high-redshift (z > 3) sub-class of GPS sources suggests that core-jet morphologies predominate in this class.

  20. Modeling the brain morphology distribution in the general aging population

    NASA Astrophysics Data System (ADS)

    Huizinga, W.; Poot, D. H. J.; Roshchupkin, G.; Bron, E. E.; Ikram, M. A.; Vernooij, M. W.; Rueckert, D.; Niessen, W. J.; Klein, S.

    2016-03-01

    Both normal aging and neurodegenerative diseases such as Alzheimer's disease cause morphological changes of the brain. To better distinguish between normal and abnormal cases, it is necessary to model changes in brain morphology owing to normal aging. To this end, we developed a method for analyzing and visualizing these changes for the entire brain morphology distribution in the general aging population. The method is applied to 1000 subjects from a large population imaging study in the elderly, from which 900 were used to train the model and 100 were used for testing. The results of the 100 test subjects show that the model generalizes to subjects outside the model population. Smooth percentile curves showing the brain morphology changes as a function of age and spatiotemporal atlases derived from the model population are publicly available via an interactive web application at agingbrain.bigr.nl.