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Morphological Structure (morphological + structure)
Selected AbstractsA computerized treatment of dyslexia: Benefits from treating lexico-phonological processing problemsDYSLEXIA, Issue 1 2005Jurgen Tijms Abstract Two hundred sixty-seven 10- to 14-year-old Dutch children with dyslexia were randomly assigned to one of two samples that received a treatment for reading and spelling difficulties. The treatment was computer-based and focused on learning to recognise and use the phonological and morphological structure of Dutch words. The inferential algorithmic basis of the program ensured that the instruction was highly structured. The present study examined the reliability of the effects of the treatment, and provided an evaluation of the attained levels of reading and spelling by relating them to normal levels. Both samples revealed large, generalized treatment effects on reading accuracy, reading rate, and spelling skills. Following the treatment, participants attained an average level of reading accuracy and spelling. The attained level of reading rate was comparable to the lower bound of the average range. Copyright © 2004 John Wiley & Sons, Ltd. [source] Nb-Doped VO2 Thin Films Prepared by Aerosol-Assisted Chemical Vapour DepositionEUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 25 2007Clara Piccirillo Abstract Niobium-doped vanadium dioxide (VxNb1,xO2, x = 0,0.037) thin films were prepared by aerosol-assisted chemical vapour deposition (AACVD) of vanadyl(IV) acetonate and niobium(V) ethoxide in ethanol. Samples were analysed by EDX, XRD, Raman, XPS and SEM. The analyses confirmed the deposition of niobium, even if no separated phase was formed; the morphological structure of the films was affected by the dopant presence. The thin films showed thermochromic behaviour, with a marked change in optical properties above and below the switching temperature. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007) [source] Determination of age-related changes in the morphological structure (sagging) of the human cheek using a photonumeric scale and three-dimensional surface parametersINTERNATIONAL JOURNAL OF COSMETIC SCIENCE, Issue 4 2000Tsukahara Synopsis The usefulness of the photo standard for evaluating skin sagging in the face, especially in the cheeks, was evaluated. A six-stage photo standard was prepared using photos of women aged 17,83-years-old at three magnification rates (136,188 women in each group). Based on this photo standard, scoring was performed using a six-grade scoring system by two specialists to obtain the consensus score. Scoring was also performed in parallel by five general observers. The degree of agreement between the two scores was evaluated by calculating the Kappa value. In each group, the Kappa value was 0.452,0.563, indicating moderate agreement. Thus, the photo standard may be useful for evaluating sagging. Based on the photo standard, a score of 2, at which sagging becomes detectable appeared at the age of 40 years. In parallel, 3D analysis of replicas around the cheek was performed to morphologically analyse age-related changes in sagging. When the depth parameter was compared between the nasolabial groove and the mouth corners, a higher value was observed in the nasolabial groove until the age of 40 years, but higher values were seen in the mouth corners thereafter. This may have been because sagging in the cheeks descends to the area around the mouth, resulting in reversion in the sWv value. These findings indicated that sagging in the cheeks becomes morphologically distinct in women in their forties. Résumé L'utilité du critère photographique afin d'évaluer l'affaissement cutané du visage, et notamment des joues, a étéévaluée. Un critère photographique en six phases a été préparé au moyen de photographies de femmes âgées de 17 à 83 ans avec trois niveaux d'agrandissement différents (136,188 femmes dans chaque groupe). En se basant sur ce critère, on a procédéà une évaluation au moyen d'un système ou échelle d'évaluation comprenant six degrés par des deux spécialistes afin d'obtenir une évaluation de référence consensuelle. Parallèlement, cinq observateurs ordinaires ont également procédéà une évaluation. Le degré d'accord entre ces deux évaluations a été estimé en calculant la valeur Kappa. Dans chaque groupe, la valeur Kappa se situait entre 0,452 et 0,563, indiquant un consensus modéré. Par conséquent, le critère photographique peut être utile afin d'évaluer l'affaissement cutané. En se basant sur le critère photographique, une évaluation de degré 2, à partir duquel l'affaissement devient détectable, est apparu à l'âge de 40 ans. Parallèlement, une analyse tridimensionnelle de répliques autour des joues a été réalisée afin d'analyser morphologiquement les modifications selon l'âge de l'affaissement. Lorsque le paramètre de profondeur a été comparé entre le sillon nasolabial et les commissures des lèvres, une valeur supérieure a été observée pour le sillon nasolabial jusqu'à l'âge de 40 ans, mais des valeurs plus élevées ont été enregistrées pour les commissures des lèvres après 40 ans. Ceci peut être dû au fait que l'affaissement des joues descend vers la zone située autour de la bouche, conduisant à une réversion de la valeur sWv. Ces résultats indiquent que l'affaissement des joues devient morphologiquement apparent chez les femmes dés la quarantaine. [source] Effect of Matrigel on adenoid cystic carcinoma cell line differentiationINTERNATIONAL JOURNAL OF EXPERIMENTAL PATHOLOGY, Issue 6 2006Márcia M. Marques Summary Adenoid cystic carcinoma (ACC) is a frequent malignant salivary gland neoplasm presenting different growth patterns described as tubular, cribriform and solid, which represent distinct differentiation stages. Cell lines originated from ACCs grown inside three-dimensional environments have not been capable to reproduce all in vivo ACC growth patterns. As ACC cells in vivo present replicated basement membrane, to mimic this situation in vitro ACC cells (CAC2 cells) were grown on the top of a reconstituted basement membrane (Matrigel). Phenotype differences were assessed by light, fluorescence and transmission electron microscopy. The cultures grown on the top of Matrigel presented three-dimensional arrangement of cells intercepted by cellular cords. At these, cell nests pseudocyst formations were observed. This morphological structure entirely reproduced the cribriform growth pattern of ACC. We suggest that the cribriform differentiation of ACC in culture is dependent of proteins and growth factors associated in a bi-dimensional structure. [source] Constituent-morpheme priming: Implications from the morphology of two-kanji compound wordsJAPANESE PSYCHOLOGICAL RESEARCH, Issue 2 2002Terry Joyce Abstract: The diversity in the morphological structure of two-kanji compound words is a matter of special concern for models of the Japanese mental lexicon. This study discusses two proposals for models of the Japanese mental lexicon ,Hirose's (1992, 1994, 1996) hypotheses and a Japanese lemma-unit version of the multilevel interactive-activation framework , in terms of their ability to cope with this diversity. As the proposals make different predictions concerning constituent-morpheme priming, patterns of facilitation were examined in two experiments with five word-formation principles as experimental conditions. Experiment 1, using the long stimulus onset asynchrony (SOA) of 3000 ms employed by Hirose (1992), only found significant differences between the first- and second-element conditions in one of the word-formation conditions. Experiment 2, using a short SOA of 250 ms, confirmed the pattern of priming obtained in Experiment 1. These results are more consistent with the prediction from the Japanese lemma-unit model. [source] Modification of cellulose fabrics with reactive polyhedral oligomeric silsesquioxanes to improve their shape-memory performanceJOURNAL OF APPLIED POLYMER SCIENCE, Issue 4 2010Kongliang Xie Abstract Reactive polyhedral oligomeric silsesquioxane (R-POSS) containing multi- N -methylol is a functional and attractive staring monomer for new reinforcement materials. R-POSS has excellent potential as a nanosized core for starburst dendrimers and highly reactive multi- N -methylol. R-POSS can be used for cellulose fabric finishing to improve its shape-memory performance. Factors affecting the crosslinking reaction of the cellulose with R-POSS were investigated. The physical properties and morphological structure of the cellulose fabrics modified with R-POSS are discussed with respect to the crease recovery angle, the whiteness index, micro-Fourier transform infrared spectroscopy, and scanning electron microscopy. The results show that the crease recovery angle of the fabric modified with R-POSS obviously increased. With increasing R-POSS concentration, the crease recovery angle of the modified fabric sharply increased. R-POSS readily crosslinked to cellulose and improved the elastic recovery of the cellulose fabrics. The surfaces of the cellulose fibers modified with R-POSS were smooth and full. The inclusion of R-POSS with dimethylol dihydroxyl ethylene urea to modify the cellulose showed very interesting results. It showed a good combination of an increase of crease recovery angle and a decrease in tensile strength. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010 [source] Neuroanatomy of the harbor porpoise (Phocoena phocoena) from magnetic resonance imagesJOURNAL OF MORPHOLOGY, Issue 3 2003Lori Marino Abstract Cetacean (dolphin, whale, and porpoise) brains are among the least-studied mammalian brains because of the formidability of collecting and histologically preparing such relatively rare and large specimens. Among cetaceans, there exist relatively few studies of the brain of the harbor porpoise (Phocoena phocoena). Magnetic resonance imaging (MRI) offers a means of observing the internal structure of the brain when traditional histological procedures are not practical. Therefore, MRI has become a critical tool in the study of the brain of cetaceans and other large species. This article represents the first MRI-based anatomically labeled three-dimensional description of the harbor porpoise brain. Coronal plane sections of the brain of a young harbor porpoise were originally acquired and used to produce virtual digital scans in the other two orthogonal spatial planes. A sequential set of images in all three planes has been anatomically labeled and displays the proportions and positions of major neuroanatomical features. These images allow for the visualizing of the distinctive features of the harbor porpoise brain from various orientations by preserving the gross morphological structure of the specimen. J. Morphol. 257:308,347, 2003. © 2003 Wiley-Liss, Inc. [source] Synthesis and hierarchical superstructures of side-chain liquid crystal polyacetylenes containing galactopyranoside end-groupsJOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 23 2009Ming-Shou Ho Abstract Three kinds of chiral saccharide-containing liquid crystalline (LC) acetylenic monomers were prepared by click reaction between 2-azidoethyl-2,3,4,6-tetraacetyl-,- D -galactopyranoside and 1-biphenylacetylene 4-alkynyloxybenzoate. The obtained monomers were polymerized by WCl6 -Ph4Sn to form three side-chain LC polyacetylenes containing 1-[2-(2,3,4,6-tetraacetyl-,- D -galactopyranos-1-yl)-ethyl]-1H -[1,2,3]-triazol-4,-biphenyl 4-alkynyloxybenzoate side groups. All monomers and polymers show a chiral smectic A phase. Self-assembled hiearchical superstructures of the chiral saccharide-containing LCs and LCPs in solution state were studied by field-emission scanning electron microscopy. Because of the LC behavior, the LC molecules exhibit a high segregation strength for phase separation in dilute solution (THF/H2O = 1:9 v/v). The self-assembled morphology of LC monomers was dependent upon the alkynyloxy chain length. Increasing the alkynyloxy chain length caused the self-assembled morphology to change from a platelet-like texture (LC-6) to helical twists morphology (LC-11 and LC-12). Furthermore, the helical twist morphological structure can be aligned on the polyimide rubbed glass substrate to form two-dimensional ordered helical patterns. In contrast to LC monomers, the LCP-11 self-assembled into much more complicate morphologies, including nanospheres and helical nanofibers. These nanofibers are evolved from the helical cables ornamented with entwining nanofibers upon natural evaporation of the solution in a mixture with a THF/methanol ratio of 3:7. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 6596,6611, 2009 [source] Long-term effects of a psycholinguistic treatment for dyslexiaJOURNAL OF RESEARCH IN READING, Issue 2 2003Jurgen Tijms Short and long-term effects of a treatment for dyslexia are evaluated. The treatment is based on psycholinguistic theory and assumes that dyslexia is due to poor lexico-phonological processing of words. The treatment is computer-based and focuses on learning to recognise and to make use of the phonological and morphological structure of Dutch words. The results of the treatment were clear improvements in reading words, reading text and spelling. Effect sizes of standardised treatment gains were large (Cohen's d>0.80 for all variables). Following the treatment, participants attained an average level of text-reading and spelling. The attained level of reading words and reading text was found to be stable over a four-year follow-up period. Spelling showed a slight decline one year after the treatment, but remained stable thereafter.1 [source] Processing, Morphology, and Mechanical Properties of Liquid Pool Polypropylene with Different Molecular WeightsMACROMOLECULAR MATERIALS & ENGINEERING, Issue 6 2005Claudia Stern Abstract Summary: The processability, morphology, and resulting mechanical properties of novel polypropylene (PP) samples of varying molecular weight () were studied. A series of homopolymer PP in a wide range from 101,000 to 1,600,000 g,·,mol,1 was polymerised in a liquid pool (LP) under defined conditions. The LP-PP with a well-known polymerisation history was manufactured into micro dumbbell specimens by means of a micro injection-moulding process. The morphology and mechanical properties of the samples were studied by light microscopy, transmission and scanning electron microscopy, and a quasi-static tensile test. Simulation of the filling behaviour of the molten polymer inside the mould shows that the shear rate increases as the molecular weight increases, up to a maximum shear rate of 750,000 s,1. In addition, the present crystallisation time of the high-molecular-weight PP samples is clearly lower than their retardation time; the long macromolecules do not have sufficient time to retard while cooling. As a result of the shear-induced crystallisation, a highly oriented crystalline structure is formed as a function of the acting shear rate. SEM and TEM investigations show the existence of an oriented shish kebab structure. The density of the shish kebab increases as the molecular weight increases. Evaluations of the shear rate and the morphological structure indicate a critical shear rate of about 300,000 s,1. Above this shear rate level, shish kebab structures are favourably formed. The shear-induced crystallisation and, therefore, the preferred formation of a highly oriented shish kebab structure lead, obviously, to unusual solid-state properties of the analysed LP-PP samples. With a tensile strength up to 100 N,·,mm,2 and an attainable strain at break of more than 30%, the mechanical performance is much higher than results ever reported in literature. True strain,stress behaviour of moulded the LP-PP samples of different molecular weight. [source] A description of the developmental stages of Acylophorus wagenschieberi Kiesenwetter, 1850 (Coleoptera, Staphylinidae), with comments on its biology, egg parasite and distribution in PolandyMITTEILUNGEN AUS DEM MUSEUM FUER NATURKUNDE IN BERLIN-DEUTSCHE ENTOMOLOGISCHE ZEITSCHRIFT, Issue 1 2005Bernard Staniec Abstract The egg, three larval instars and pupa of Acylophorus wagenschieberi Kiesenwetter are described for the first time, with the illustrations of structural features provided. Adult habitus and figures for penis are given. Differences in the morphological structure of its larval instars (L1,3) cover: the number and structure of setae on protibia, the number of setae on tarsungulus, the number of setae on pygopod, the structure of urogomphi, the body color and the measurements of size. Diagnostic characters of immature stages are listed. Modifications of the keys to known eggs, larvae and pupae of the European Staphylininae species are proposed. Some data on its distribution, environmental requirements and biology with the schema of life cycle in the field are also provided. It is stenotopic and one of the rarest-occurring Staphylininae species in its whole distribution range, in Poland known from 13 localities (11 recorded by the author). It occurs exclusively on high- and transitional moors, preferring the ecotone zones between water bodies and the surrounding peatbogs. One of the main factors limiting its occurrences and abundance is the high and stable water level. A. wagenschieberi is a monovoltine species with the summer larvae and wintering imago. Considering its environmental preferences and biology this rove beetle may be of essential importance as a good environmental state indicator. Trimorus fulvimanus Kiefer (Scelionidae, Proctotrupoidea, Hymenoptera) has been recorded as an egg parasite of A. wagenschieberi. (© 2005 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] A Chandra observation of the disturbed cluster core of Abell 2204MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, Issue 3 2005J. S. Sanders ABSTRACT We present results from an observation of the luminous cluster of galaxies Abell 2204 using the Chandra X-ray Observatory. We show the core of the cluster has a complex morphological structure, made up of a high-density core (ne, 0.2 cm,3) with flat surface brightness, a surrounding central plateau, a tail-like feature, wrapping around to the east, and an unusual radio source. A temperature map and deprojected profile shows that the temperature rises steeply outside these regions, until around ,100 kpc where it drops, then rises again. Abundance maps and profiles show that there is a corresponding increase in abundance at the same radius as where the temperature drops. In addition, there are two cold fronts at radii of ,28 and 54.5 kpc. The disturbed morphology indicates that the cluster core may have undergone a merger. However, despite this disruption, the mean radiative cooling time in the centre is short (,230 Myr) and the morphology is regular on large scales. [source] Diversity of essential oil glands of clary sage (Salvia sclarea L., Lamiaceae)PLANT BIOLOGY, Issue 4 2008C. Schmiderer Abstract The Lamiaceae is rich in aromatic plant species. Most of these species produce and store essential oils in specialised epidermal oil glands, which are responsible for their specific flavour. Two types of glands producing essential oil and possessing different morphological structure can be found in Salvia sclarea: peltate and capitate glands. The content of single oil glands from different positions on the plant (corolla, calyx and leaf) were sampled using an SPME fibre and analysed by gas chromatography in order to study variability of the essential oil composition. It was found that the composition of terpenoids is quite variable within an individual plant. Capitate oil glands mainly produce three essential oil compounds: the monoterpenes linalool and linalyl acetate, and the diterpene sclareol. Peltate oil glands, however, accumulate noticeable concentrations of sesquiterpenes and an unknown compound (m/z = 354). Furthermore, the oil composition varies within each gland type according to the plant organ. Linalool and linalyl acetate are characteristic substances of flowers, whereas the sesquiterpenes occur in higher proportions in leaves. Even within one gland type on a single leaf, the chemical variability is exceedingly high. [source] Evaluation of the interfacial state in high impact polystyrene through dynamic mechanical analysis as a function of the synthesis conditions,POLYMER ENGINEERING & SCIENCE, Issue 11 2007R. Díaz de León High impact polystyrene was synthesized using two series of styrene/butadiene (SB) tapered block copolymers with a polystyrene (PS)/polybutadiene (PB) composition of 30/70 and 10/90 wt%. During the synthesis, concentration of initiator, SB and transfer agent were varied. From dynamic mechanical analysis, the corresponding , relaxation of the rubber phase was detected at low temperature (near ,100°C) and that of the glassy PS phase at high temperature (near 100°C). Also, another relaxation at temperature near 40°C was identified, which was associated to the , relaxation of the glassy PS phase. The variations found in the , relaxation of the rubber phase, were attributed to changes in the morphological structure as a consequence of variation in initiator, SB or transfer agent concentrations and in SB composition. , relaxation showed a strong dependency with the interfacial state between the rubber and the glassy phase, where an increase in the amount of graft PS at the interface, which promotes the interfacial adhesion between phases, causes an increase in the magnitude of , relaxation of the PS phase. The results were attributed to variations in the interfacial area as a result of the change in the particle size and to the contribution of molecular chains of each phase in participating in the relaxation process. POLYM. ENG. SCI., 47:1827,1838, 2007. © 2007 Society of Plastics Engineers [source] Structure and properties of star-shaped solution-polymerized styrene-butadiene rubber and its co-coagulated rubber filled with silica/carbon black-I: morphological structure and mechanical propertiesPOLYMERS FOR ADVANCED TECHNOLOGIES, Issue 11 2009Xiao Liu Abstract The morphological structure and mechanical properties of the star-shaped solution-polymerized styrene-butadiene rubber (SSBR) and organically modified nanosilica powder/star-shaped SSBR co-coagulated rubber (N-SSBR) both filled with silica/carbon black (CB) were studied. The results showed that, compared with SSBR, silica powder could be mixed into N-SSBR much more rapidly, and N-SSBR/SiO2 nanocomposite had better filler-dispersion and processability. N-SSBR/SiO2/CB vulcanizates displayed higher glass-transition temperature and lower peak value of internal friction loss than SSBR/SiO2/CB vulcanizates. In the N-SSBR/SiO2/CB vulcanizates, filler was dispersed in nano-scale resulting in good mechanical properties. Composites filled with silica/CB doped filler exhibited more excellent mechanical properties than those filled with a single filler because of the better filler-dispersion and stronger interfacial interaction with macromolecular chains. N-SSBR/SiO2/CB vulcanizates exhibited preferable performance in abrasion resistance and higher bound rubber content as the blending ratio of silica to CB was 20:30. Copyright © 2008 John Wiley & Sons, Ltd. [source] Organic,inorganic hybrid membranes prepared from the sol,gel process of poly(butyleneadipate- co -terephthalate) and TiO2POLYMERS FOR ADVANCED TECHNOLOGIES, Issue 8 2009Chien-Hong Lin Abstract Organic,inorganic hybrids based on poly(butyleneadipate- co -terephthalate)/titanium dioxide (PBAT/TiO2) hybrid membranes were prepared via a sol,gel process. The PBAT/TiO2 hybrid membranes were prepared for various PBAT/TiO2 ratios. The resulting hybrids were characterized with a morphological structure, hydrophilicity, biodegradability, and thermal properties. The results showed that macrovoids underwent a transition into a sponge-like membrane structure with the addition of TiO2. After sol,gel transition, a strong interaction between the inorganic network and polymeric chains led to an increase in glass transition temperature (Tg), thermal degrading temperature, and hydrophilicity, and hence a higher biodegradability. According to X-ray diffraction measurements of the crystal structure of the hybrid, the presence of TiO2 did not change the crystal structure of PBAT. TiO2 networks are uniformly dispersed into the PBAT matrix and no aggregation of TiO2 networks in the hybrid membranes was observed through the small angle X-ray scattering measurements. Thus, the sol,gel process of PBAT and TiO2 can be used to prepare a hybrid with higher application temperature and faster biodegradation rate. Copyright © 2008 John Wiley & Sons, Ltd. [source] Semantic transparency and masked morphological priming: An ERP investigationPSYCHOPHYSIOLOGY, Issue 4 2007Joanna Morris Abstract The role of semantics in the segmentation of morphologically complex words was examined using event-related potentials (ERPs) recorded to target words primed by semantically transparent (hunter,hunt,) opaque (corner,corn), and orthographically related (scandal,scan) masked primes. Behavioral data showed that only transparent items gave rise to priming. The ERP data showed both N250 and the N400 effects with transparent items generating greater priming than orthographic or opaque. Furthermore, priming effects across conditions revealed the existence of a significant linear trend, with transparent items showing the greatest effects and orthographic items the smallest, suggesting that these priming effects vary as a function of morphological structure and semantic transparency. The results are discussed in terms of a model of morphological processing. [source] Biogeographical, ecological and morphological structure in a phylogenetic analysis of Ateleia (Swartzieae, Fabaceae) derived from combined molecular, morphological and chemical dataBOTANICAL JOURNAL OF THE LINNEAN SOCIETY, Issue 1 2010HELEN E. IRELAND A phylogenetic analysis of combined morphological, chemical and ITS/5.8S sequence data reveals that species of Ateleia are often more genetically than morphologically divergent, and that species thought to be most closely related morphologically are distant relatives within the genus. Ateleia shows niche conservatism, with most species confined to seasonally dry tropical forest in Central America and the Caribbean, and fewer species in the same biome in South America. Four independent transitions to wet forests may have occurred in the genus. The estimated ages of Ateleia lineages spanning Central and South America are either older or younger than the estimated age of closure of the Isthmus of Panama. The older dates clearly suggest that over-water dispersal is responsible for the distribution of Ateleia that includes the Caribbean Islands. © 2010 The Linnean Society of London, Botanical Journal of the Linnean Society, 2010, 162, 39,53. [source] Influence of melt drawing on the morphology of one- and two-step processed LDPE/thermoplastic starch blendsADVANCES IN POLYMER TECHNOLOGY, Issue 4 2003F. J. Rodriguez-Gonzalez Abstract In this study the morphology of LDPE/TPS blends prepared by a one-step extrusion process is compared to that obtained by reprocessing of the original blends. The influence of composition and melt drawing is examined. A novel methodology based on the form factor of the dispersed particle was used to estimate the equivalent spherical particle size of dispersed thermoplastic starch (TPS). This approach allows for the quantitative comparison of average dispersed phase particles regardless of their shape. Blends prepared in the one-step extrusion process show increased levels of anisotropy as a consequence of a combination of coalescence and particle deformation during melt drawing. Reprocessed materials demonstrate morphologies that are highly stable to a wide range of hot stretch ratio conditions. The TPS particles of reprocessed blends show no coalescence and a low degree of deformation. This phenomenon is explained by plasticizer evaporation resulting from the second processing step. The TPS is transformed from a highly deformable phase to one resembling a partially cross-linked material. These data indicate that the one-step processing of LDPE/TPS blends can be used to generate a wide range of highly elongated morphological structures. A two-step approach, analogous to typical compounding and shaping operations and involving controlled glycerol removal in the second step can be used to prepare a wide range of highly stable, more isotropic, dispersed particle morphologies. © 2003 Wiley Periodicals, Inc. Adv Polym Techn 22: 297,305, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/adv.10057 [source] Comparative postnatal ontogeny of the skull in the australidelphian metatherian Dasyurus albopunctatus (Marsupialia: Dasyuromorpha: Dasyuridae)JOURNAL OF MORPHOLOGY, Issue 4 2006David A. Flores Abstract We describe the cranial ontogeny of an australidelphian marsupial, Dasyurus albopunctatus, using a combination of qualitative and quantitative approaches. We examined in detail qualitative morphological changes of just-weaned individuals as compared to old adults; specifically, changes in 31 morphological structures (e.g., processes, foramina) and 38 changes in cranial joints. We also interpreted growth-invariant structures in terms of their functional relevance. We performed a multivariate allometry analysis based on 14 cranial measurements taken from 31 specimens encompassing the entire postweaning period. Three variables (height of occipital plate, breadth of braincase, and height of mandible) showed the same allometric trends in D. albopunctatus and the three marsupial species studied previously in the same framework (Didelphis albiventris, Lutreolina crassicaudata, and Dromiciops gliroides). In addition, D. albopunctatus shared allometric trends in two variables (length of the upper postcanine row and length of the orbit) with the microbiotheriid D. gliroides. Most of the growth trends observed are interpreted as linked to the predominantly carnivorous dietary habit of adult D. albopunctatus. Because dasyuromorphians are most likely basal to the major Australasian radiation of marsupials, knowledge of ontogenetic changes in D. albopunctatus may shed light on the evolution of ontogeny in the highly diverse Australasian marsupial fauna. J. Morphol. © 2006 Wiley-Liss, Inc. [source] Morphological biosignatures from relict fossilised sedimentary geological specimens: a Raman spectroscopic studyJOURNAL OF RAMAN SPECTROSCOPY, Issue 10 2007Howell G. M. Edwards Abstract Morphological biosignatures (features related to life) and associated terrestrial sedimentary structures that provide possible sampling targets for the remote astrobiological exploration of planets have been analysed using Raman spectroscopic techniques. The spectral data from a suite of samples comprising crypto-chasmoendoliths, preserved microbial filaments and relict sedimentary structures comprise a preliminary database for the establishment of key Raman biosignatures. This will form the basis for the evaluation of prototype miniaturised instrumentation for the proposed ESA ExoMars mission scheduled for 2013. The Raman spectral biosignatures of carotenoids and scytonemin, organic biomolecules characteristic of the cyanobacterial colonisation of geological matrices and biogeologically modified minerals are also identifiable in the sedimentary specimen materials. The results of this study demonstrate the basis of the molecular recognition of extinct and extant exobiology that will feed into the elemental structural analyses of morphological structures provided by associated SEM, XRD and laser-induced breakdown spectroscopy (LIBS) techniques on robotic analytical landers. Copyright © 2007 John Wiley & Sons, Ltd. [source] Morphology of the first instar of Calliphora vicina, Phormia regina and Lucilia illustris (Diptera, Calliphoridae)MEDICAL AND VETERINARY ENTOMOLOGY, Issue 1 2008K. SZPILA Abstract Scanning electron microscopy documentation of first instar Calliphora vicina Robineau-Desvoidy, Phormia regina (Meigen) and Lucilia illustris (Meigen) (Diptera: Calliphoridae) is presented for the first time, and the following morphological structures are documented: pseudocephalon; antenna; maxillary palpus; facial mask; labial lobe; thoracic and abdominal spinulation; spiracular field; posterior spiracles, and anal pad. Light microscopy documentation and illustrations are provided for the cephaloskeleton in lateral and ventral views. New diagnostic features are revealed in the configuration of the facial mask, cephaloskeleton and posterior spiracles. The first instar morphology of C. vicina, Ph. regina and L. illustris is discussed in the light of existing knowledge about early instars of blowflies. [source] Progress in Parasitic Plant Biology: Host Selection and Nutrient TransferPLANT BIOLOGY, Issue 2 2006H. Shen Abstract: Host range varies widely among species of parasitic plants. Parasitic plants realize host selection through induction by chemical molecular signals, including germination stimulants and haustoria-inducing factors (HIFs). Research on parasitic plant biology has provided information on germination, haustorium induction, invasion, and haustorial structures and functions. To date, some molecular mechanisms have been suggested to explain how germination stimulants work, involving a chemical change caused by addition of a nucleophilic protein receptor, and direct or indirect stimulation of ethylene generation. Haustorium initiation is induced by HIFs that are generated by HIF-releasing enzymes from the parasite or triggered by redox cycling between electrochemical states of the inducers. Haustorium attachment is non-specific, however, the attachment to a host is facilitated by mucilaginous substances produced by haustorial hairs. Following the attachment, the intrusive cells of parasites penetrate host cells or push their way through the host epidermis and cortex between host cells, and some types of cell wall-degrading enzymes may assist in the penetration process. After the establishment of host-parasite associations, parasitic plants develop special morphological structures (haustoria) and physiological characteristics, such as high transpiration rates, high leaf conductance, and low water potentials in hemiparasites, for nutrient transfer and resource acquisition from their hosts. Therefore, they negatively affect the growth and development and even cause death of their hosts. [source] Effects of synthesis conditions on crystal morphological structures and thermal degradation behavior of hydrotalcites and flame retardant and mechanical properties of EVA/hydrotalcite blendsPOLYMER COMPOSITES, Issue 2 2007Longchao Du The effects of synthesis methods and reaction conditions on the crystal morphological structures and thermal degradation behavior of hydrotalcites have been studied by X-ray diffraction (XRD), transmission electron microscopy (TEM), particle size analysis (PSA), and differential thermal analysis (DTA). The flame retardant and mechanical properties of ethylene,vinyl acetate (EVA) blends with the corresponding hydrotalcites have been estimated by limiting oxygen index (LOI), UL-94, and mechanical measurements. The results from the XRD, TEM, and PSA demonstrate that the hydrotalcites synthesized by ultrasound method have larger crystal sizes and particle size distribution than those by mechanical stirring method. Higher reaction temperature, longer dripping time, and lower solution concentration can increase the crystal and particle sizes of ultrasound-synthesized hydrotalcites, whereas the longer ultrasound aging time can increase the crystal sizes and decrease the particle sizes of hydrotalcites because of the smashing conglomeration. The DTA data give a positive evidence that the hydrotalcite samples prepared by mechanical stirring method with longer alkaline dripping time have higher thermal degradation temperature than those by ultrasound method, since the ultrasound-synthesized hydrotalcites have more lattice defects than stirring-prepared hydrotalcites. The data from LOI, UL-94, and mechanical tests show that the ultrasonic-synthesized hydrotalcites have better flame retardant properties, whereas the stirring-synthesized hydrotalcites have better tensile strength in the EVA/hydrotalcite blends. POLYM. COMPOS., 28:131,138, 2007. © 2007 Society of Plastics Engineers [source] Process,structure,property relationships of erodable polymeric biomaterials, I: Poly(desaminotyrosyl arylates),POLYMERS FOR ADVANCED TECHNOLOGIES, Issue 10-12 2002Michael Jaffe Abstract Polymeric biomaterials, especially new compositions, are often tested for biocompatibility, bioerosion rate or cell growth specificity without regard to the morphological structures introduced during materials processing. It will be shown that in addition to the potential influence on biological response, processing induced structure profoundly influences materials properties under bio-relevant conditions. Using a combinatorial library of erodable Polyarylates, these issues will be explored with emphasis on in-vivo dimensional stability and mechanical property retention. Copyright © 2003 John Wiley & Sons, Ltd. [source] Detailed Visualization of the Functional Regions of the Rat Pituitary Gland by High-Resolution T2-Weighted MRIANATOMIA, HISTOLOGIA, EMBRYOLOGIA, Issue 3 2010E. Theunissen With 5 figures and 1 table Summary This high-resolution MRI study focuses on the visualization of the detailed morphology of the rat's pituitary gland by means of post-mortem as well as in vivo MRI at 9.4 T. Determination of the local T1- and T2-relaxation decay times allows to explain the regional image intensities which reflects the degree of tissue organization at the molecular level. Detailed characterization of the molecular level of the pituitary gland, as provided by the relaxation decay times, can offer a rigid platform with respect to functional or pathological explorations. It is demonstrated that T1-weighted imaging, as is routinely used in the clinic, can differentiate between the posterior and anterior lobe but not between the posterior and intermediate lobe. T2-weighted images, however, clearly show the three distinct lobes of the rat pituitary gland without the use of contrast agents, i.e. the posterior, the intermediate and the anterior lobe. Histological analysis of the rat's pituitary gland confirms the morphological structures seen on the MR images. Although the intermediate lobe is less defined in humans and can neither be differentiated by T1-weighted MRI, its clinical visualization might be possible in T2-weighted images. [source] Microelectrona cladara gen. et sp. nov.: A New Protodikraneurini from the Eocene Baltic Amber (Hemiptera: Cicadomorpha: Cicadellidae: Typhlocybinae)ACTA GEOLOGICA SINICA (ENGLISH EDITION), Issue 4 2010Jacek SZWEDO Abstract: A new genus Microelectrona gen. nov. and species Microelectrona cladara sp. nov. of the extinct tribe Protodikraneurini of the leafhoppers (Cicadellidae: Typhlocybinae) from the Eocene Baltic amber is described. The piece of amber containing leafhopper inclusion is broken, unveiling some of the morphological structures, and enabling their studies using scanning electron microscopy. [source] Electrochemical Synthesis of Dendritic Polyaniline in Brønsted Acid Ionic LiquidsCHINESE JOURNAL OF CHEMISTRY, Issue 7 2005Liu Bao-You Abstract Brønsted acid ionic liquids were successfully applied to the electrochemical synthesis of polyaniline films on platinum electrode surfaces by using cyclic voltammetry. The scanning electron micrographs showed distinct changes in morphological structures. The films exhibited quite dense packing and good ordering of polymer dendrite as compared with those prepared using conventional hydrochloric acid, indicating that Brønsting acid ionic liquids might be promising alternatives to dual medium-dopants in the synthesis of conducting polymers. [source] | |||||||||||||||||||||||||