Interspecific variation in the tetradactyl manus of modern tapirs (Perissodactyla: Tapirus) exposed using geometric morphometrics.

PubMed

MacLaren, Jamie A; Nauwelaerts, Sandra

2017-11-01

The distal forelimb (autopodium) of quadrupedal mammals is a key morphological unit involved in locomotion, body support, and interaction with the substrate. The manus of the tapir (Perissodactyla: Tapirus) is unique within modern perissodactyls, as it retains the plesiomorphic tetradactyl (four-toed) condition also exhibited by basal equids and rhinoceroses. Tapirs are known to exhibit anatomical mesaxonic symmetry in the manus, although interspecific differences and biomechanical mesaxony have yet to be rigorously tested. Here, we investigate variation in the manus morphology of four modern tapir species (Tapirus indicus, Tapirus bairdii, Tapirus pinchaque, and Tapirus terrestris) using a geometric morphometric approach. Autopodial bones were laser scanned to capture surface shape and morphology was quantified using 3D-landmark analysis. Landmarks were aligned using Generalised Procrustes Analysis, with discriminant function and partial least square analyses performed on aligned coordinate data to identify features that significantly separate tapir species. Overall, our results support the previously held hypothesis that T. indicus is morphologically separate from neotropical tapirs; however, previous conclusions regarding function from morphological differences are shown to require reassessment. We find evidence indicating that T. bairdii exhibits reduced reliance on the lateral fifth digit compared to other tapirs. Morphometric assessment of the metacarpophalangeal joint and the morphology of the distal facets of the lunate lend evidence toward high loading on the lateral digits of both the large T. indicus (large body mass) and the small, long limbed T. pinchaque (ground impact). Our results support other recent studies on T. pinchaque, suggesting subtle but important adaptations to a compliant but inclined habitat. In conclusion, we demonstrate further evidence that the modern tapir forelimb is a variable locomotor unit with a range of interspecific features tailored to habitual and biomechanical needs of each species. © 2017 Wiley Periodicals, Inc.

Clinal variation or validation of a subspecies? A case study of the Graptemys nigrinoda complex (Testudines: Emydidae)

USGS Publications Warehouse

Ennen, Joshua R.; Kalis, Marley E.; Patterson, Adam L.; Kreiser, Brian R.; Lovich, Jeffrey E.; Godwin, James; Qualls, Carl P.

2014-01-01

Widely distributed species often display intraspecific morphological variation due to the abiotic and biotic gradients experienced across their ranges. Historically, in many vertebrate taxa, such as birds and reptiles, these morphological differences within a species were used to delimit subspecies. Graptemys nigrinoda is an aquatic turtle species endemic to the Mobile Bay Basin. Colour pattern and morphological variability were used to describe a subspecies (G. n. delticola) from the lower reaches of the system, although it and the nominate subspecies also reportedly intergrade over a large portion of the range. Other researchers have suggested that these morphological differences merely reflect clinal variation. Our molecular data (mtDNA) did not support the existence of the subspecies, as the haplotypes were differentiated by only a few base pairs and one haplotype was shared between the putative subspecies. While there were significant morphological and pattern differences among putative specimens of G. n. nigrinoda, G. n. delticola and G. n. nigrinoda × delticola, these differences probably represent clinal variation as they were also related to environmental variables [i.e. cumulative drainage area and drainage (categorical)]. Specimens occupying slow-current, high-turbidity river reaches (e.g. the Tensaw River) exhibited greater relative carapace heights and more dark pigmentation, while specimens occupying fast-current, clearer rivers (e.g. the upper Alabama, Cahaba and Tallapoosa rivers) exhibited lower carapace heights and more yellow pigmentation. Given the absence of clear molecular and morphological differences that are related to drainage characteristics, we suggest that there is not sufficient evidence for the recognition of G. n. delticola as a distinct subspecies.

Local versus Generalized Phenotypes in Two Sympatric Aurelia Species: Understanding Jellyfish Ecology Using Genetics and Morphometrics

PubMed Central

Chiaverano, Luciano M.; Bayha, Keith W.; Graham, William M.

2016-01-01

For individuals living in environmentally heterogeneous environments, a key component for adaptation and persistence is the extent of phenotypic differentiation in response to local environmental conditions. In order to determine the extent of environmentally induced morphological variation in a natural population distributed along environmental gradients, it is necessary to account for potential genetic differences contributing to morphological differentiation. In this study, we set out to quantify geographic morphological variation in the moon jellyfish Aurelia exposed at the extremes of a latitudinal environmental gradient in the Gulf of Mexico (GoM). We used morphological data based on 28 characters, and genetic data taken from mitochondrial cytochrome oxidase I (COI) and nuclear internal transcribed spacer 1 (ITS-1). Molecular analyses revealed the presence of two genetically distinct species of Aurelia co-occurring in the GoM: Aurelia sp. 9 and Aurelia c.f. sp. 2, named for its divergence from (for COI) and similarity to (for ITS-1) Aurelia sp. 2 (Brazil). Neither species exhibited significant population genetic structure between the Northern and the Southeastern Gulf of Mexico; however, they differed greatly in the degree of geographic morphological variation. The morphology of Aurelia sp. 9 exhibited ecophenotypic plasticity and varied significantly between locations, while morphology of Aurelia c.f. sp. 2 was geographically invariant (i.e., canalized). The plastic, generalist medusae of Aurelia sp. 9 are likely able to produce environmentally-induced, “optimal” phenotypes that confer high relative fitness in different environments. In contrast, the non-plastic generalist individuals of Aurelia c.f. sp. 2 likely produce environmentally-independent phenotypes that provide the highest fitness across environments. These findings suggest the two Aurelia lineages co-occurring in the GoM were likely exposed to different past environmental conditions (i.e., different selective pressures) and evolved different strategies to cope with environmental variation. This study highlights the importance of using genetics and morphometric data to understand jellyfish ecology, evolution and systematics. PMID:27332545

Local versus Generalized Phenotypes in Two Sympatric Aurelia Species: Understanding Jellyfish Ecology Using Genetics and Morphometrics.

PubMed

Chiaverano, Luciano M; Bayha, Keith W; Graham, William M

2016-01-01

For individuals living in environmentally heterogeneous environments, a key component for adaptation and persistence is the extent of phenotypic differentiation in response to local environmental conditions. In order to determine the extent of environmentally induced morphological variation in a natural population distributed along environmental gradients, it is necessary to account for potential genetic differences contributing to morphological differentiation. In this study, we set out to quantify geographic morphological variation in the moon jellyfish Aurelia exposed at the extremes of a latitudinal environmental gradient in the Gulf of Mexico (GoM). We used morphological data based on 28 characters, and genetic data taken from mitochondrial cytochrome oxidase I (COI) and nuclear internal transcribed spacer 1 (ITS-1). Molecular analyses revealed the presence of two genetically distinct species of Aurelia co-occurring in the GoM: Aurelia sp. 9 and Aurelia c.f. sp. 2, named for its divergence from (for COI) and similarity to (for ITS-1) Aurelia sp. 2 (Brazil). Neither species exhibited significant population genetic structure between the Northern and the Southeastern Gulf of Mexico; however, they differed greatly in the degree of geographic morphological variation. The morphology of Aurelia sp. 9 exhibited ecophenotypic plasticity and varied significantly between locations, while morphology of Aurelia c.f. sp. 2 was geographically invariant (i.e., canalized). The plastic, generalist medusae of Aurelia sp. 9 are likely able to produce environmentally-induced, "optimal" phenotypes that confer high relative fitness in different environments. In contrast, the non-plastic generalist individuals of Aurelia c.f. sp. 2 likely produce environmentally-independent phenotypes that provide the highest fitness across environments. These findings suggest the two Aurelia lineages co-occurring in the GoM were likely exposed to different past environmental conditions (i.e., different selective pressures) and evolved different strategies to cope with environmental variation. This study highlights the importance of using genetics and morphometric data to understand jellyfish ecology, evolution and systematics.

EFFECTS OF POND CHARACTERISTICS ON BIOTIC EXPOSURES

EPA Science Inventory

Different aquatic communities, although apparently equivalent, can exhibit a variety of responses when challenged with the same initial total toxicant concentration. ifferences in realized actual exposure concentrations can result from differences in physical morphology, water an...

Southern high latitude squat lobsters II: description of Uroptychus macquariae sp. nov. from Macquarie Ridge.

PubMed

Schnabel, Kareen E; Burghardt, Ingo; Ahyong, Shane T

2017-11-23

Squat lobsters have only recently been recorded from the Macquarie Ridge, which extends south between New Zealand and Antarctica. Among these, Uroptychus insignis (Henderson, 1885) was recorded for the first time outside the western Indian Ocean, exhibiting only subtle morphological differences. Reexamination of the Macquarie Ridge and Indian Ocean specimens attributed to U. insignis using morphological and molecular data revealed the Macquarie Ridge form to represent a separate species. Subtle but consistent morphological differences are evident and partial CO1 sequence data indicates that the specimens collected on Macquarie Ridge differ from those collected in the Indian Ocean by more than 7%. The Macquarie Ridge species is described herein as Uroptychus macquariae n.sp. Subtle morphological differences between the new species and U. insignis are discussed.

Non-Mendelian determinants of morphology in fungi.

PubMed

Malagnac, Fabienne; Silar, Philippe

2003-12-01

Morphological plasticity is a hallmark of eumycetes. In addition to genes and environment, epigenetic factors control cell, colony and thallus forms in many species, by creating reversible switches. Current knowledge indicates that the different shapes are due to structural or regulatory heritable states of cytoplasmic components. Cellular physiology differs in the various forms, permitting adaptation to fluctuation in the environment. These switches are part of the adaptation repertoire that fungi exhibit to colonize most niches.

Morphology effect of nano-hydroxyapatite as a drug carrier of methotrexate.

PubMed

Sun, Haina; Liu, Shanshan; Zeng, Xiongfeng; Meng, Xianguang; Zhao, Lina; Wan, Yizao; Zuo, Guifu

2017-09-13

In this study, morphology effect of nano-hydroxyapatite as a drug carrier was investigated for the first time. Hydroxyapatite/methotrexate (HAp/MTX) hybrids with different morphologies were successfully prepared in situ using polyethylene glycol (PEG) as a template. SEM, TEM, XRD and FTIR results confirmed that the hybrids of different morphologies (laminated, rod-like and spherical) with similar phase composition and functional groups were obtained by changing the preparation parameters. UV-Vis spectroscopy was used to identify the drug loading capacity and drug release mechanism of the three hybrids with different morphologies. It is concluded that the laminated hybrid exhibits a higher drug loading capacity compared to the other two hybrids, and all the three hybrids showed a sustained slow release which were fitted well by Bhaskar equation. Additionally, the result of in vitro bioassay test confirms that the inhibition efficacy of the three hybrids showed a positive correlation to the drug loading capacity.

Morphological effect of BiVO4 catalysts on degradation of aqueous paracetamol under visible light irradiation.

PubMed

Hu, Changying; Xu, Jie; Zhu, Yaqi; Chen, Acong; Bian, Zhaoyong; Wang, Hui

2016-09-01

Morphological effect of bismuth vanadate (BiVO4) on visible light-driven catalytic degradation of aqueous paracetamol was carefully investigated using four monoclinic BiVO4 catalysts. The catalysts with different morphologies were controllably prepared by a hydrothermal method without any additions. The prepared catalysts were fully characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and UV-Vis diffuse reflectance spectroscopy (DRS). Under the visible light irradiation, these catalysts with different morphology were investigated to degrade aqueous paracetamol contaminant. The degradation effects were evaluated based on the catalyst morphology, solution pH, initial paracetamol concentration, and catalyst dosage. Cube-like BiVO4 powders exhibited excellent photocatalytic performance. The optimal photocatalytic performance of the cube-like BiVO4 in degrading paracetamol was achieved.

Morphology and laccase production of white-rot fungi grown on wheat bran flakes under semi-solid-state fermentation conditions.

PubMed

Osma, Johann F; Moilanen, Ulla; Toca-Herrera, José L; Rodríguez-Couto, Susana

2011-05-01

In this paper, we studied the laccase production and the growth morphology of different white-rot fungi, i.e. Pleurotus ostreatus, Trametes pubescens, Cerrena unicolor and Trametes versicolor, cultured under semi-solid-state fermentation conditions using wheat bran flakes as a natural low-cost support substrate. Trametes versicolor exhibited the highest laccase activity per gram of total dry matter, followed by P. ostreatus (63.5 and 58.2Ug(-1) , respectively). In addition, they showed a time profile of laccase production that was quite similar. Growth morphology was studied using environmental microscopic images and analyzed by discrete Fourier transformation-based software to determine the mean diameter of the hyphae, the number of hypha layers and the global micromorphology. The four strains exhibited different micromorphologies of growth. Pleurotus ostreatus presented narrow hyphae, which formed many thick clumps, T. pubescens and T. versicolor showed clumps of different sizes and C. unicolor showed thick hyphae that formed larger clumps, but in less amounts. © 2011 Federation of European Microbiological Societies. Published by Blackwell Publishing Ltd. All rights reserved.

Comparison of stem morphology and anatomy of two alfalfa clonal lines exhibiting divergent cell wall composition

USDA-ARS?s Scientific Manuscript database

In previous research, two alfalfa clonal lines (252, 1283) were identified that exhibited environmentally stable differences in stem cell walls. Compared to stems of 1283, stems of 252 have a higher cell wall concentration and greater amounts of lignin and cellulose but reduced levels of pectic suga...

Galaxy Zoo: Morphological Classification of Galaxy Images from the Illustris  Simulation

NASA Astrophysics Data System (ADS)

Dickinson, Hugh; Fortson, Lucy; Lintott, Chris; Scarlata, Claudia; Willett, Kyle; Bamford, Steven; Beck, Melanie; Cardamone, Carolin; Galloway, Melanie; Simmons, Brooke; Keel, William; Kruk, Sandor; Masters, Karen; Vogelsberger, Mark; Torrey, Paul; Snyder, Gregory F.

2018-02-01

Modern large-scale cosmological simulations model the universe with increasing sophistication and at higher spatial and temporal resolutions. These ongoing enhancements permit increasingly detailed comparisons between the simulation outputs and real observational data. Recent projects such as Illustris are capable of producing simulated images that are designed to be comparable to those obtained from local surveys. This paper tests the degree to which Illustris achieves this goal across a diverse population of galaxies using visual morphologies derived from Galaxy Zoo citizen scientists. Morphological classifications provided by these volunteers for simulated galaxies are compared with similar data for a compatible sample of images drawn from the Sloan Digital Sky Survey (SDSS) Legacy Survey. This paper investigates how simple morphological characterization by human volunteers asked to distinguish smooth from featured systems differs between simulated and real galaxy images. Significant differences are identified, which are most likely due to the limited resolution of the simulation, but which could be revealing real differences in the dynamical evolution of populations of galaxies in the real and model universes. Specifically, for stellar masses {M}\\star ≲ {10}11 {M}ȯ , a substantially larger proportion of Illustris galaxies that exhibit disk-like morphology or visible substructure, relative to their SDSS counterparts. Toward higher masses, the visual morphologies for simulated and observed galaxies converge and exhibit similar distributions. The stellar mass threshold indicated by this divergent behavior confirms recent works using parametric measures of morphology from Illustris simulated images. When {M}\\star ≳ {10}11 {M}ȯ , the Illustris data set contains substantially fewer galaxies that classifiers regard as unambiguously featured. In combination, these results suggest that comparison between the detailed properties of observed and simulated galaxies, even when limited to reasonably massive systems, may be misleading.

[Grape seed extract induces morphological changes of prostate cancer PC-3 cells].

PubMed

Shang, Xue-Jun; Yin, Hong-Lin; Ge, Jing-Ping; Sun, Yi; Teng, Wen-Hui; Huang, Yu-Feng

2008-12-01

To observe the morphological changes of prostate cancer PC-3 cells induced by grape seed extract (GSE). PC-3 cells were incubated with different concentrations of GSE (100, 200 and 300 microg/ml) for 24, 48 and 72 hours, and then observed for morphological changes by invert microscopy, HE staining and transmission electron microscopy. The incubated PC-3 cells appeared round, small, wrinkled and broken under the invert microscope and exhibited the classical morphological characteristics of cell death under the electron microscope, including cell atrophy, increased vacuoles, crumpled nuclear membrane, and chromosome aggregation. GSE can cause morphological changes and induce necrosis and apoptosis of PC-3 cells.

Genetic backgrounds and redox conditions influence morphological characteristics and cell differentiation of osteoclasts in mice.

PubMed

Narahara, Shun; Matsushima, Haruna; Sakai, Eiko; Fukuma, Yutaka; Nishishita, Kazuhisa; Okamoto, Kuniaki; Tsukuba, Takayuki

2012-04-01

Osteoclasts (OCLs) are multinucleated giant cells and are formed by the fusion of mononuclear progenitors of monocyte/macrophage lineage. It is known that macrophages derived from different genetic backgrounds exhibit quite distinct characteristics of immune responses. However, it is unknown whether OCLs from different genetic backgrounds show distinct characteristics. In this study, we showed that bone-marrow macrophages (BMMs) derived from C57BL/6, BALB/c and ddY mice exhibited considerably distinct morphological characteristics and cell differentiation into OCLs. The differentiation of BMMs into OCLs was comparatively quicker in the C57BL/6 and ddY mice, while that of BALB/c mice was rather slow. Morphologically, ddY OCLs showed a giant cell with a round shape, C57BL/6 OCLs were of a moderate size with many protrusions and BALB/c OCLs had the smallest size with fewer nuclei. The intracellular signaling of differentiation and expression levels of marker proteins of OCLs were different in the respective strains. Treatment of BMMs from the three different strains with the reducing agent N-acetylcysteine (NAC) or with the oxidation agent hydrogen peroxide (H(2)O(2)) induced changes in the shape and sizes of the cells and caused distinct patterns of cell differentiation and survival. Thus, genetic backgrounds and redox conditions regulate the morphological characteristics and cell differentiation of OCLs.

Sexual selection and the rodent baculum: an intraspecific study in the house mouse (Mus musculus domesticus).

PubMed

Ramm, Steven A; Khoo, Lin; Stockley, Paula

2010-01-01

The rapid divergence of genitalia is a pervasive trend in animal evolution, thought to be due to the action of sexual selection. To test predictions from the sexual selection hypothesis, we here report data on the allometry, variation, plasticity and condition dependence of baculum morphology in the house mouse (Mus musculus domesticus). We find that that baculum size: (a) exhibits no consistent pattern of allometric scaling (baculum size being in most cases unrelated to body size), (b) exhibits low to moderate levels of phenotypic variation, (c) does not exhibit phenotypic plasticity in response to differences in perceived levels of sexual competition and (d) exhibits limited evidence of condition dependence. These patterns provide only limited evidence in support of the sexual selection hypothesis, and no consistent support for any particular sexual selection mechanism; however, more direct measures of how genital morphology influences male fertilization success are required.

One-step fabrication of BaMoO4 microstructures with controlled morphologies via a simple EDTA-mediated route

NASA Astrophysics Data System (ADS)

Yin, Yongkui; Li, Ying; Zhang, Haifeng; Ren, Fengyun; Zhang, Dawei; Feng, Wenxu; Shao, Lili; Li, Kaijun; Liu, Yang; Sun, Zhanpeng; Li, Miaojing; Song, Gaochen; Wang, Guan

2013-03-01

A facile strategy has been developed to synthesize BaMoO4 microcrystals with different morphologies, such as octopus-like, flower-like, and Chinese-cabbage-like, by using ethylenediaminetetraacetic acid as chelating and capping reagent at room temperature. X-ray diffraction, field emission scanning electron microscopy, and Fourier transformer infrared spectroscopy were introduced to characterize the composition, morphology, and chemical information of the as-obtained products. The effects of a series of experimental parameters, such as ethylenediaminetetraacetic acid quantity and the reagent concentrations, on the morphology and photoluminescence properties of the consequential BaMoO4 microcrystals were investigated in detail. The photoluminescence spectra of the obtained BaMoO4 microstructures exhibited different emission intensities. This method could be readily extended to synthesize BaWO4 microstructures with various morphologies.

Neomorphosis and heterochrony of skull shape in dog domestication.

PubMed

Geiger, Madeleine; Evin, Allowen; Sánchez-Villagra, Marcelo R; Gascho, Dominic; Mainini, Cornelia; Zollikofer, Christoph P E

2017-10-18

The overall similarity of the skull shape of some dog breeds with that of juvenile wolves begs the question if and how ontogenetic changes such as paedomorphosis (evolutionary juvenilisation) played a role in domestication. Here we test for changes in patterns of development and growth during dog domestication. We present the first geometric morphometric study using ontogenetic series of dog and wolf crania, and samples of dogs with relatively ancestral morphology and from different time periods. We show that patterns of juvenile-to-adult morphological change are largely similar in wolves and domestic dogs, but differ in two ways. First, dog skulls show unique (neomorphic) features already shortly after birth, and these features persist throughout postnatal ontogeny. Second, at any given age, juvenile dogs exhibit skull shapes that resemble those of consistently younger wolves, even in dog breeds that do not exhibit a 'juvenilized' morphology as adults. These patterns exemplify the complex nature of evolutionary changes during dog domestication: the cranial morphology of adult dogs cannot simply be explained as either neomorphic or paedomorphic. The key to our understanding of dog domestication may lie in a closer comparative examination of developmental phases.

ZnO nanostructures with different morphology for enhanced photocatalytic activity

NASA Astrophysics Data System (ADS)

Peter, I. John; Praveen, E.; Vignesh, G.; Nithiananthi, P.

2017-12-01

ZnO nanomaterials of different morphologies have been synthesized and the effect of morphology on Photocatalytic activity on natural dye has been investigated. Crystalline size and lattice strain of the synthesized particles are determined by XRD analysis and Williamson-Hall (W-H) method respectively. All other important physical parameters such as strain, stress and energy density values are also calculated using W-H analysis using different models such as uniform deformation model, uniform deformation stress model and uniform deformation energy density model. A shift in the peak of FTIR spectrum of ZnO is observed due to morphology effects. The SEM analysis reveals that the synthesized ZnO nanoparticles appear as flake, rod and dot. ZnO quantum dot exhibits higher photocatalytic activity comparing to the other morphologies. Larger surface area, high adsorption rate, large charge separation and the slow recombination of electrons/holes in ZnO dots establish dots as favorable morphology for good photocatalysis. Among the three, ZnO quantum dot shows three-times enhancement in the kinetic rate constants of photocatalysis. The results confirm that availability of specific (active) surface area, photocatalytic potential and quantum confinement of photo-induced carriers differ with morphology.

Generic model of morphological changes in growing colonies of fungi

NASA Astrophysics Data System (ADS)

López, Juan M.; Jensen, Henrik J.

2002-02-01

Fungal colonies are able to exhibit different morphologies depending on the environmental conditions. This allows them to cope with and adapt to external changes. When grown in solid or semisolid media the bulk of the colony is compact and several morphological transitions have been reported to occur as the external conditions are varied. Here we show how a unified simple mathematical model, which includes the effect of the accumulation of toxic metabolites, can account for the morphological changes observed. Our numerical results are in excellent agreement with experiments carried out with the fungus Aspergillus oryzae on solid agar.

Analysis of Phosphate Acquisition Efficiency in Different Arabidopsis Accessions

PubMed Central

Narang, Ram A.; Bruene, Asja; Altmann, Thomas

2000-01-01

The morphological and physiological characteristics of Arabidopsis accessions differing in their phosphate acquisition efficiencies (PAEs) when grown on a sparingly soluble phosphate source (hydroxylapatite) were analyzed. A set of 36 accessions was subjected to an initial PAE evaluation following cultivation on synthetic, agarose-solidified media containing potassium phosphate (soluble) or hydroxylapatite (sparingly soluble). From the five most divergent accessions identified in this way, C24, Co, and Cal exhibited high PAEs, whereas Col-0 and Te exhibited low PAEs. These five accessions were analyzed in detail. Significant differences were found in root morphology, phosphate uptake kinetics, organic acid release, rhizosphere acidification, and the ability of roots to penetrate substrates. Long root hairs at high densities, high uptake per unit root length, and high substrate penetration ability in the efficient accessions C24 and Co mediate their high PAEs. The third accession with high PAE, Cal, exhibits a high shoot-to-root ratio, long roots with long root hairs, and rhizosphere acidification. These results are consistent with previous observations and highlight the suitability of using Arabidopsis accessions to identify and isolate genes determining the PAE in plants. PMID:11115894

Detecting cryptic speciation in the widespread and morphologically conservative carpet chameleon (Furcifer lateralis) of Madagascar.

PubMed

Florio, A M; Ingram, C M; Rakotondravony, H A; Louis, E E; Raxworthy, C J

2012-07-01

Species delimitation within recently evolved groups can be challenging because species may be difficult to distinguish morphologically. Following the General Lineage Concept, we apply a multiple evidence approach to assess species limits within the carpet chameleon Furcifer lateralis, which is endemic to Madagascar and exported in large numbers for the pet trade. Cryptic speciation within F. lateralis was considered likely because this species (1) has a vast distribution, (2) occupies exceptionally diverse habitats and (3) exhibits subtle regional differences in morphology. Phylogenetic trees reconstructed using nuclear and mitochondrial genes recovered three well-supported clades corresponding with geography. Morphological results based on canonical variates analysis show that these clades exhibit subtle differences in head casque morphology. Ecological niche modelling results found that these phylogenetic groups also occupy unique environmental space and exhibit patterns of regional endemism typical of other endemic reptiles. Combined, our findings provide diverse yet consistent evidence for the existence of three species. Consequently, we elevate the subspecies F. lateralis major to species rank and name a new species distributed in northern and western Madagascar. Initial ecological divergence, associated with speciation of F. lateralis in humid eastern habitat, fits the Ecographic Constraint model for species diversification in Madagascar. By contrast, the second speciation event provides some support for the Riverine Barrier model, with the Mangoky River possibly causing initial isolation between species. These findings thus support two contrasting models of speciation within closely related species and demonstrate the utility of applying a combined-evidence approach for detecting cryptic speciation. © 2012 The Authors. Journal of Evolutionary Biology © 2012 European Society For Evolutionary Biology.

The neocortex of cetartiodactyls. II. Neuronal morphology of the visual and motor cortices in the giraffe (Giraffa camelopardalis).

PubMed

Jacobs, Bob; Harland, Tessa; Kennedy, Deborah; Schall, Matthew; Wicinski, Bridget; Butti, Camilla; Hof, Patrick R; Sherwood, Chet C; Manger, Paul R

2015-09-01

The present quantitative study extends our investigation of cetartiodactyls by exploring the neuronal morphology in the giraffe (Giraffa camelopardalis) neocortex. Here, we investigate giraffe primary visual and motor cortices from perfusion-fixed brains of three subadults stained with a modified rapid Golgi technique. Neurons (n = 244) were quantified on a computer-assisted microscopy system. Qualitatively, the giraffe neocortex contained an array of complex spiny neurons that included both "typical" pyramidal neuron morphology and "atypical" spiny neurons in terms of morphology and/or orientation. In general, the neocortex exhibited a vertical columnar organization of apical dendrites. Although there was no significant quantitative difference in dendritic complexity for pyramidal neurons between primary visual (n = 78) and motor cortices (n = 65), there was a significant difference in dendritic spine density (motor cortex > visual cortex). The morphology of aspiny neurons in giraffes appeared to be similar to that of other eutherian mammals. For cross-species comparison of neuron morphology, giraffe pyramidal neurons were compared to those quantified with the same methodology in African elephants and some cetaceans (e.g., bottlenose dolphin, minke whale, humpback whale). Across species, the giraffe (and cetaceans) exhibited less widely bifurcating apical dendrites compared to elephants. Quantitative dendritic measures revealed that the elephant and humpback whale had more extensive dendrites than giraffes, whereas the minke whale and bottlenose dolphin had less extensive dendritic arbors. Spine measures were highest in the giraffe, perhaps due to the high quality, perfusion fixation. The neuronal morphology in giraffe neocortex is thus generally consistent with what is known about other cetartiodactyls.

Neurochemical, morphologic, and laminar characterization of cortical projection neurons in the cingulate motor areas of the macaque monkey

NASA Technical Reports Server (NTRS)

Nimchinsky, E. A.; Hof, P. R.; Young, W. G.; Morrison, J. H.; Bloom, F. E. (Principal Investigator)

1996-01-01

The primate cingulate gyrus contains multiple cortical areas that can be distinguished by several neurochemical features, including the distribution of neurofilament protein-enriched pyramidal neurons. In addition, connectivity and functional properties indicate that there are multiple motor areas in the cortex lining the cingulate sulcus. These motor areas were targeted for analysis of potential interactions among regional specialization, connectivity, and cellular characteristics such as neurochemical profile and morphology. Specifically, intracortical injections of retrogradely transported dyes and intracellular injection were combined with immunocytochemistry to investigate neurons projecting from the cingulate motor areas to the putative forelimb region of the primary motor cortex, area M1. Two separate groups of neurons projecting to area M1 emanated from the cingulate sulcus, one anterior and one posterior, both of which furnished commissural and ipsilateral connections with area M1. The primary difference between the two populations was laminar origin, with the anterior projection originating largely in deep layers, and the posterior projection taking origin equally in superficial and deep layers. With regard to cellular morphology, the anterior projection exhibited more morphologic diversity than the posterior projection. Commissural projections from both anterior and posterior fields originated largely in layer VI. Neurofilament protein distribution was a reliable tool for localizing the two projections and for discriminating between them. Comparable proportions of the two sets of projection neurons contained neurofilament protein, although the density and distribution of the total population of neurofilament protein-enriched neurons was very different in the two subareas of origin. Within a projection, the participating neurons exhibited a high degree of morphologic heterogeneity, and no correlation was observed between somatodendritic morphology and neurofilament protein content. Thus, although the neurons that provide the anterior and posterior cingulate motor projections to area M1 differ morphologically and in laminar origin, their neurochemical profiles are similar with respect to neurofilament protein. This suggests that neurochemical phenotype may be a more important unifying feature for corticocortical projections than morphology.

Preparation, characterization and luminescence properties of a new hydrous red phosphor CaB3 O5 (OH):Eu3+ with different morphologies.

PubMed

Huang, H S; Tang, A J; Yang, C; Jin, H F

2017-03-01

A new borate phosphor CaB 3 O 5 (OH):Eu 3 + with different morphologies was synthesized using a hydrothermal method and its luminescence properties were studied. The effects of surfactants on the crystal structures, morphologies and luminescence properties of the samples were studied. The results showed that the surfactants play an important role in controlling the morphology and improving the luminescence properties of phosphors. The luminescence intensity and R/O(I615/I592) value were enhanced for the prepared sample by adding PEG4000. The prepared sample exhibited a higher R/O than some anhydrous calcium borate phosphors, indicating that this product could serve as a new potential red phosphor. Copyright © 2016 John Wiley & Sons, Ltd.

Morphological study of polymethyl methacrylate microcapsules filled with self-healing agents

NASA Astrophysics Data System (ADS)

Ahangaran, Fatemeh; Hayaty, Mehran; Navarchian, Amir H.

2017-03-01

Polymethyl methacrylate (PMMA) microcapsules filled with epoxy prepolymer, 3-aminomethyl-3,5,5-trimethylcyclohexylamine, and pentaerythritol tetrakis (3-mercaptopropionate) as healing agents have been prepared separately through internal phase separation method for self-healing purposes. PMMA with two different molecular weights (M bar1 = 36,000 g/mol and M bar2 = 550,000 g/mol) were used with two types of different emulsifiers (ionic and polymeric) to prepare microcapsules. The morphology of healing agent microcapsules was investigated using field emission scanning electron microscopy (FESEM). It was found that PMMA microcapsules separately filled with epoxy and amine had core-shell morphologies with smooth surfaces. The mercaptan/PMMA particles exhibited core-shell and acorn-shape morphologies. The surface morphology of mercaptan microcapsules changed from holed to plain in different emulsion systems. The spreading coefficient (S) of phases in the prepared emulsion systems were calculated from interfacial tension (σ) and contact angle (θ) measurements. The theoretical equilibrium morphology of PMMA microcapsules was predicted according to spreading coefficient values of phases in emulsion systems. It was also found that the surface morphology of PMMA microcapsules depended strongly on the nature of the core, molecular weight of PMMA, type and concentration of emulsifier.

Shape, form, function and Leishmania pathogenicity: from textbook descriptions to biological understanding

PubMed Central

Gull, Keith

2017-01-01

The shape and form of protozoan parasites are inextricably linked to their pathogenicity. The evolutionary pressure associated with establishing and maintaining an infection and transmission to vector or host has shaped parasite morphology. However, there is not a ‘one size fits all’ morphological solution to these different pressures, and parasites exhibit a range of different morphologies, reflecting the diversity of their complex life cycles. In this review, we will focus on the shape and form of Leishmania spp., a group of very successful protozoan parasites that cause a range of diseases from self-healing cutaneous leishmaniasis to visceral leishmaniasis, which is fatal if left untreated. PMID:28903998

Direct growth of ZnO tetrapod on glass substrate by Chemical Vapor Deposition Technique

NASA Astrophysics Data System (ADS)

Fadzil, M. F. M.; Rahman, R. A.; Azhar, N. E. A.; Aziz, T. N. T. A.; Zulkifli, Z.

2018-03-01

This research demonstrates the growth of ZnO tetrapod structure on glass substrate for different types of flow gas and at different growth temperatures. The study on the morphological structure and electrical properties of ZnO thin film growth by Chemical Vapour Deposition (CVD) technique showed that the optimum growth temperature was obtained at 750°C with ZnO nanotetrapod morphological structure. Introducing Nitrogen gas flow during the growth process exhibited leg-to-leg linking ZnO tetrapods morphology. The electrical properties of ZnO tetrapods film were measured by using two point probes and it shows that, the sample growth in Ar and O2 atmosphere have better I-V characteristic.

Gender-related traits in the dioecious shrub Empetrum rubrum in two plant communities in the Magellanic steppe

NASA Astrophysics Data System (ADS)

Díaz-Barradas, Mari Cruz; Zunzunegui, María; Collantes, Marta; Álvarez-Cansino, Leonor; García Novo, Francisco

2014-10-01

Following the theory on costs of reproduction, sexually dimorphic plants may exhibit several trade-offs in energy and resources that can determine gender dimorphism in morphological or physiological traits, especially during the reproductive period. In this study we assess whether the sexes of the dioecious species Empetrum rubrum differ in morphological and ecophysiological traits related to water economy and photochemical efficiency and whether these differences change in nearby populations with contrasting plant communities. We conducted physiological, morphological, sex ratio, and cover measurements in E. rubrum plants in the Magellanic steppe, North-Eastern part of Tierra del Fuego (Argentina), from two types of heathlands with differing community composition. We found differences between sites in soil pH and wind speed at the canopy level. E. rubrum plants exhibited lower photosynthetic height and higher LAI (leaf area index), lower RWC (relative water content) and higher water-use efficiency (lower Δ13C) in the heathland with harsher environmental conditions. Gender dimorphism in the physiological response was patent for photochemical efficiency and water use (RWC and Δ13C discrimination), with males showing a more conservative strategy in relation to females. Accordingly, male-biased sex ratio in the stress-prone community suggested a better performance of male plants under stressful environmental conditions. The integrated analysis of all variables (photochemical efficiency, RWC, leaf dry matter content (LDMC), pigments, and Δ13C) indicated an interaction between gender and heathland community effects in the physiological response. We suggest that female plants may exhibit compensatory mechanisms to face their higher reproductive costs.

Controlled Synthesis and Photocatalytic Antifouling Properties of BiVO4 with Tunable Morphologies

NASA Astrophysics Data System (ADS)

Xiang, Zhenbo; Wang, Yi; Ju, Peng; Zhang, Dun

2017-02-01

Monoclinic BiVO4 with different nanostructures were prepared via a facile and rapid route by adding different surfactants. Ethylenediaminetetraacetic acid, polyvinylpyrrolidone, and sodium dodecyl sulfate surfactants were selected as morphology controlling agents. The crystal phase, morphology, and diffuse reflectance spectra of BiVO4 were characterized by x-ray diffraction, scanning electron microscopy, and UV-visible diffuse reflectance spectra techniques, respectively. The photocatalytic activities of BiVO4 were investigated by killing the typical marine fouling bacteria Pseudomonas aeruginosa ( P. aeruginosa) under visible light irradiation. BiVO4 with grape-like nanostructure exhibited the best photocatalytic bactericidal activity. The sterilization rate of P. aeruginosa could reach up to 99.9% in 120 min. The photocatalytic mechanism was studied by captive species trapping experiments. The result revealed that photogenerated hole (h+) is the main reactive specie for killing P. aeruginosa under visible light irradiation. In addition, after five recycles, BiVO4 does not exhibit significant loss of photocatalytic sterilization activity. The results confirm that the synthesized BiVO4 photocatalyst has long-time reusability and good photocatalytic stability.

Parallel functional category deficits in clauses and nominal phrases: The case of English agrammatism

PubMed Central

Wang, Honglei; Yoshida, Masaya; Thompson, Cynthia K.

2015-01-01

Individuals with agrammatic aphasia exhibit restricted patterns of impairment of functional morphemes, however, syntactic characterization of the impairment is controversial. Previous studies have focused on functional morphology in clauses only. This study extends the empirical domain by testing functional morphemes in English nominal phrases in aphasia and comparing patients’ impairment to their impairment of functional morphemes in English clauses. In the linguistics literature, it is assumed that clauses and nominal phrases are structurally parallel but exhibit inflectional differences. The results of the present study indicated that aphasic speakers evinced similar impairment patterns in clauses and nominal phrases. These findings are consistent with the Distributed Morphology Hypothesis (DMH), suggesting that the source of functional morphology deficits among agrammatics relates to difficulty implementing rules that convert inflectional features into morphemes. Our findings, however, are inconsistent with the Tree Pruning Hypothesis (TPH), which suggests that patients have difficulty building complex hierarchical structures. PMID:26379370

Effect of morphology and solvent on two-photon absorption of nano zinc oxide

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kavitha, M.K.; Haripadmam, P.C.; Gopinath, Pramod

Highlights: ► ZnO nanospheres and triangular structures synthesis by novel precipitation technique. ► The effect of precursor concentration on the size and shape of nano ZnO. ► Open aperture Z-scan measurements of the ZnO nanoparticle dispersions. ► Nanospheres exhibit higher two photon absorption coefficient than triangular nanostructures. ► Nanospheres dispersed in water exhibit higher two photon absorption coefficient than its dispersion in 2-propanol. - Abstract: In this paper, we report the effect of morphology and solvent on the two-photon absorption of nano zinc oxide. Zinc oxide nanoparticles in two different morphologies like nanospheres and triangular nanostructures are synthesized by novelmore » precipitation technique and their two-photon absorption coefficient is measured using open aperture Z-scan technique. Experimental results show that the zinc oxide nanospheres exhibit higher two-photon absorption coefficient than the zinc oxide triangular nanostructures. The zinc oxide nanospheres dispersed in water exhibit higher two-photon absorption coefficient than that of its dispersion in 2-propanol. The zinc oxide nanospheres dispersed in water shows a decrease in two-photon absorption coefficient with an increase in on-axis irradiance. The result confirms the dependence of shape and solvent on the two-photon absorption of nano zinc oxide.« less

Substantial photovoltaic response and morphology tuning in benzo[1,2-b:6,5-b']dithiophene (bBDT) molecular donors.

PubMed

Harschneck, Tobias; Zhou, Nanjia; Manley, Eric F; Lou, Sylvia J; Yu, Xinge; Butler, Melanie R; Timalsina, Amod; Turrisi, Riccardo; Ratner, Mark A; Chen, Lin X; Chang, Robert P H; Facchetti, Antonio; Marks, Tobin J

2014-04-21

The influence of solubilizing substituents on the photovoltaic performance and thin-film blend morphology of new benzo[1,2-b:6,5-b']dithiophene (bBDT) based small molecule donor semiconductors is investigated. Solar cells based on bBDT(TDPP)2-PC71BM with two different types of side chains exhibit high power conversion efficiencies, up to 5.53%.

Root canal morphology of South Asian Indian maxillary molar teeth

PubMed Central

Singh, Shishir; Pawar, Mansing

2015-01-01

Objective: The objective was to study the root canal morphology of South Asian Indian Maxillary molars using a tooth clearing technique. Materials and Methods: Hundred teeth each comprising of first, second, and third molars collected from different dental schools and clinics in India were subjected to standard dye penetration, decalcification and clearing procedure before being studied. Results: The first molar mesiobuccal roots exhibited 69% Type I, 24% Type II, 4% Type IV, 2% Type V, and 1% exhibited a Vertuccis Type VIII canal anatomy. In the group with three separate roots the second molar mesiobuccal roots in exhibited 80.6% Type I, 15.3% Type II, 2.7% Type IV, and 1.4% Type V canal anatomy while the third molars mesiobuccal roots exhibited 57.4% Type I, 32% Type II, 2.1% Type III, 8.5% Type IV, 1% had a Type V canal anatomy in the similar group. Conclusion: A varied root canal anatomy was seen in the mesiobuccal root canal of the maxillary molars. PMID:25713497

DISPLACEMENT CASCADE SIMULATION IN TUNGSTEN AT 1025 K

DOE Office of Scientific and Technical Information (OSTI.GOV)

Setyawan, Wahyu; Nandipati, Giridhar; Roche, Kenneth J.

2013-09-30

Molecular dynamics simulation was employed to investigate the irradiation damage properties of bulk tungsten at 1025 K (0.25 melting temperature). A comprehensive data set of primary cascade damage was generated up to primary knock-on atom (PKA) energies 100 keV. The dependence of the number of surviving Frenkel pairs (NFP) on the PKA energy (E) exhibits three different characteristic domains presumably related to the different cascade morphologies that form. The low-energy regime < 0.2 keV is characterized by a hit-or-miss type of Frenkel pair (FP) production near the displacement threshold energy of 128 eV. The middle regime 0.3 – 30 keVmore » exhibits a sublinear dependence of log(NFP) vs log(E) associated with compact cascade morphology with a slope of 0.73. Above 30 keV, the cascade morphology consists of complex branches or interconnected damage regions. In this extended morphology, large interstitial clusters form from superposition of interstitials from nearby damage regions. Strong clustering above 30 keV results in a superlinear dependence of log(NFP) vs log(E) with a slope of 1.365. At 100 keV, an interstitial cluster of size 92 and a vacancy cluster of size 114 were observed.« less

Solvent-controlled preparation and photocatalytic properties of nanostructured TiO{sub 2} thin films with different morphologies

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ao, Yanhui, E-mail: andyao@hhu.edu.cn; Gao, Yinyin; Wang, Peifang

2014-01-01

Graphical abstract: Low-temperature growth of nanostructured TiO{sub 2} thin films was presented by a solvent-controlled method. Nanoparticle structured films in anatase phase have been successfully fabricated with some adjustment. The effects of the solvent were investigated and the formation mechanism was proposed. - Highlights: • Nanostructured TiO{sub 2} thin films with different morphologies were obtained at low temperature. • The effects of the solvent on the morphologies of the products were investigated. • The effects of the solvent on the phtocatalytic activity were investigated. - Abstract: A low-temperature growth method of nanostructured TiO{sub 2} thin films with different morphologies wasmore » reported. Rod-like, grass-like and nanosheet structured films have been successfully fabricated just by adjusting the ratio of different solvents. The effects of the solvent on the morphologies of the TiO{sub 2} nanostructures were investigated. The formation mechanism of different morphologies was proposed based on the experiment results. The as-prepared samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM). The photocatalytic activity of as-prepared samples for the degradation of methylene blue (MB) in water was evaluated under UV illumination. Results showed that the solvents exhibited important effect on the morphologies and photocatalytic activity of as-prepared nanostructured titania films.« less

Distributed effects of biological sex define sex-typical motor behavior in Caenorhabditis elegans.

PubMed

Mowrey, William R; Bennett, Jessica R; Portman, Douglas S

2014-01-29

Sex differences in shared behaviors (for example, locomotion and feeding) are a nearly universal feature of animal biology. Though these behaviors may share underlying neural programs, their kinematics can exhibit robust differences between males and females. The neural underpinnings of these differences are poorly understood because of the often-untested assumption that they are determined by sex-specific body morphology. Here, we address this issue in the nematode Caenorhabditis elegans, which features two sexes with distinct body morphologies but similar locomotor circuitry and body muscle. Quantitative behavioral analysis shows that C. elegans and related nematodes exhibit significant sex differences in the dynamics and geometry of locomotor body waves, such that the male is generally faster. Using a recently proposed model of locomotor wave propagation, we show that sex differences in both body mechanics and the intrinsic dynamics of the motor system can contribute to kinematic differences in distinct mechanical contexts. By genetically sex-reversing the properties of specific tissues and cells, however, we find that sex-specific locomotor frequency in C. elegans is determined primarily by the functional modification of shared sensory neurons. Further, we find that sexual modification of body wall muscle together with the nervous system is required to alter body wave speed. Thus, rather than relying on a single focus of modification, sex differences in motor dynamics require independent modifications to multiple tissue types. Our results suggest shared motor behaviors may be sex-specifically optimized though distributed modifications to several aspects of morphology and physiology.

Distributed Effects of Biological Sex Define Sex-Typical Motor Behavior in Caenorhabditis elegans

PubMed Central

Mowrey, William R.; Bennett, Jessica R.

2014-01-01

Sex differences in shared behaviors (for example, locomotion and feeding) are a nearly universal feature of animal biology. Though these behaviors may share underlying neural programs, their kinematics can exhibit robust differences between males and females. The neural underpinnings of these differences are poorly understood because of the often-untested assumption that they are determined by sex-specific body morphology. Here, we address this issue in the nematode Caenorhabditis elegans, which features two sexes with distinct body morphologies but similar locomotor circuitry and body muscle. Quantitative behavioral analysis shows that C. elegans and related nematodes exhibit significant sex differences in the dynamics and geometry of locomotor body waves, such that the male is generally faster. Using a recently proposed model of locomotor wave propagation, we show that sex differences in both body mechanics and the intrinsic dynamics of the motor system can contribute to kinematic differences in distinct mechanical contexts. By genetically sex-reversing the properties of specific tissues and cells, however, we find that sex-specific locomotor frequency in C. elegans is determined primarily by the functional modification of shared sensory neurons. Further, we find that sexual modification of body wall muscle together with the nervous system is required to alter body wave speed. Thus, rather than relying on a single focus of modification, sex differences in motor dynamics require independent modifications to multiple tissue types. Our results suggest shared motor behaviors may be sex-specifically optimized though distributed modifications to several aspects of morphology and physiology. PMID:24478342

Physiological and morphological responses of pine and willow saplings to post-fire salvage logging

NASA Astrophysics Data System (ADS)

Millions, E. L.; Letts, M. G.; Harvey, T.; Rood, S. B.

2015-12-01

With global warming, forest fires may be increasing in frequency, and post-fire salvage logging may become more common. The ecophysiological impacts of this practice on tree saplings remain poorly understood. In this study, we examined the physiological and morphological impacts of increased light intensity, due to post-fire salvage logging, on the conifer Pinus contorta (pine) and deciduous broadleaf Salix lucida (willow) tree and shrub species in the Crowsnest Pass region of southern Alberta. Photosynthetic gas-exchange and plant morphological measurements were taken throughout the summer of 2013 on approximately ten year-old saplings of both species. Neither species exhibited photoinhibition, but different strategies were observed to acclimate to increased light availability. Willow saplings were able to slightly elevate their light-saturated rate of net photosynthesis (Amax) when exposed to higher photosynthetic photon flux density (PPFD), thus increasing their growth rate. Willow also exhibited increased leaf inclination angles and leaf mass per unit area (LMA), to decrease light interception in the salvage-logged plot. By contrast, pine, which exhibited lower Amax and transpiration (E), but higher water-use efficiency (WUE = Amax/E) than willow, increased the rate at which electrons were moved through and away from the photosynthetic apparatus in order to avoid photoinhibition. Acclimation indices were higher in willow saplings, consistent with the hypothesis that species with short-lived foliage exhibit greater acclimation. LMA was higher in pine saplings growing in the logged plot, but whole-plant and branch-level morphological acclimation was limited and more consistent with a response to decreased competition in the logged plot, which had much lower stand density.

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.

Isolated Polynucleotides and Methods of Promoting a Morphology in a Fungus

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lasure, Linda L; Dai, Ziyu

2008-10-21

The invention includes isolated polynucleotide molecules that are differentially expressed in a native fungus exhibiting a first morphology relative to the native fungus exhibiting a second morphology. The invention includes a method of enhancing a bioprocess utilizing a fungus. A transformed fungus is produced by transforming a fungus with a recombinant polynucleotide molecule. The recombinant polynucleotide molecule contains an isolated polynucleotide sequence linked operably to a promoter. The polynucleotide sequence is expressed to promote a first morphology. The first morphology of the transformed fungus enhances a bioprocess relative to the bioprocess utilizing a second morphology.

The microgeographical patterns of morphological and molecular variation of a mixed ploidy population in the species complex Actinidia chinensis.

PubMed

Liu, Yifei; Li, Dawei; Yan, Ling; Huang, Hongwen

2015-01-01

Polyploidy and hybridization are thought to have significant impacts on both the evolution and diversification of the genus Actinidia, but the structure and patterns of morphology and molecular diversity relating to ploidy variation of wild Actinidia plants remain much less understood. Here, we examine the distribution of morphological variation and ploidy levels along geographic and environmental variables of a large mixed-ploidy population of the A. chinensis species complex. We then characterize the extent of both genetic and epigenetic diversity and differentiation exhibited between individuals of different ploidy levels. Our results showed that while there are three ploidy levels in this population, hexaploids were constituted the majority (70.3%). Individuals with different ploidy levels were microgeographically structured in relation to elevation and extent of niche disturbance. The morphological characters examined revealed clear difference between diploids and hexaploids, however tetraploids exhibited intermediate forms. Both genetic and epigenetic diversity were high but the differentiation among cytotypes was weak, suggesting extensive gene flow and/or shared ancestral variation occurred in this population even across ploidy levels. Epigenetic variation was clearly correlated with changes in altitudes, a trend of continuous genetic variation and gradual increase of epigenomic heterogeneities of individuals was also observed. Our results show that complex interactions between the locally microgeographical environment, ploidy and gene flow impact A. chinensis genetic and epigenetic variation. We posit that an increase in ploidy does not broaden the species habitat range, but rather permits A. chinensis adaptation to specific niches.

Growth of different phases and morphological features of MnS thin films by chemical bath deposition: Effect of deposition parameters and annealing

NASA Astrophysics Data System (ADS)

Hannachi, Amira; Maghraoui-Meherzi, Hager

2017-03-01

Manganese sulfide thin films have been deposited on glass slides by chemical bath deposition (CBD) method. The effects of preparative parameters such as deposition time, bath temperature, concentration of precursors, multi-layer deposition, different source of manganese, different complexing agent and thermal annealing on structural and morphological film properties have been investigated. The prepared thin films have been characterized using the X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive X-ray analysis (EDX). It exhibit the metastable forms of MnS, the hexagonal γ-MnS wurtzite phase with preferential orientation in the (002) plane or the cubic β-MnS zinc blende with preferential orientation in the (200) plane. Microstructural studies revealed the formation of MnS crystals with different morphologies, such as hexagons, spheres, cubes or flowers like.

Asynchronous evolution of physiology and morphology in Anolis lizards.

PubMed

Hertz, Paul E; Arima, Yuzo; Harrison, Alexis; Huey, Raymond B; Losos, Jonathan B; Glor, Richard E

2013-07-01

Species-rich adaptive radiations typically diversify along several distinct ecological axes, each characterized by morphological, physiological, and behavioral adaptations. We test here whether different types of adaptive traits share similar patterns of evolution within a radiation by investigating patterns of evolution of morphological traits associated with microhabitat specialization and of physiological traits associated with thermal biology in Anolis lizards. Previous studies of anoles suggest that close relatives share the same "structural niche" (i.e., use the same types of perches) and are similar in body size and shape, but live in different "climatic niches" (i.e., use habitats with different insolation and temperature profiles). Because morphology is closely tied to structural niche and field active body temperatures are tied to climatic niches in Anolis, we expected phylogenetic analyses to show that morphology is more evolutionarily conservative than thermal physiology. In support of this hypothesis, we find (1) that thermal biology exhibits more divergence among recently diverged Anolis taxa than does morphology; and (2) diversification of thermal biology among all species often follows diversification in morphology. These conclusions are remarkably consistent with predictions made by anole biologists in the 1960s and 1970s. © 2013 The Author(s). Evolution © 2013 The Society for the Study of Evolution.

Biogenic twinned crystals exhibiting unique morphological symmetry

NASA Astrophysics Data System (ADS)

Hirsch, Anna; Gur, Dvir; Palmer, Ben; Addadi, Lia; Leiserowitz, Leslie; Kronik, Leeor

Guanine crystals are widely used in nature as components of multilayer reflectors. Organisms control the size, morphology, and arrangement of these crystals, to obtain a variety of optical ''devices''. The reflection systems found in the lens of the scallop eye and in the copepod cuticle are unique in that the multilayered reflectors are tiled together to form a contiguous packed array. In the former, square crystals are tiled to form a reflecting mirror. In the latter, hexagonal crystals are closely packed to produce brilliant colors. Based on electron diffraction, morphology considerations, and density functional theory, these crystals were shown to possess similar monoclinic crystal symmetry, which we have previously identified as different from that of synthetic anhydrous guanine. However, the crystals are different in that multiple twinning about the {012} and the {011} crystallographic planes results in square and hexagonal morphology, respectively. This is a unique example where controlled twinning is used as a strategy to form a morphology with higher symmetry than that of the underlying crystal, allowing for tilling that facilitates optical functionality.

In-Kennel Behavior Predicts Length of Stay in Shelter Dogs

PubMed Central

Protopopova, Alexandra; Mehrkam, Lindsay Renee; Boggess, May Meredith; Wynne, Clive David Lawrence

2014-01-01

Previous empirical evaluations of training programs aimed at improving dog adoption rates assume that dogs exhibiting certain behaviors are more adoptable. However, no systematic data are available to indicate that the spontaneous behavior of shelter dogs has an effect on adopter preference. The aim of the present study was to determine whether any behaviors that dogs exhibit spontaneously in the presence of potential adopters were associated with the dogs' length of stay in the shelter. A sample of 289 dogs was videotaped for 1 min daily throughout their stay at a county shelter. To account for differences in adopter behavior, experimenters varied from solitary passive observers to pairs of interactive observers. Dogs behaved more attentively to active observers. To account for adopter preference for morphology, dogs were divided into “morphologically preferred” and “non-preferred” groups. Morphologically preferred dogs were small, long coated, ratters, herders, and lap dogs. No theoretically significant differences in behavior were observed between the two different dog morphologies. When accounting for morphological preference, three behaviors were found to have a significant effect on length of stay in all dogs: leaning or rubbing on the enclosure wall (increased median length of stay by 30 days), facing away from the front of the enclosure (increased by 15 days), and standing (increased by 7 days). When combinations of behaviors were assessed, back and forth motion was found to predict a longer stay (increased by 24 days). No consistent behavioral changes were observed due to time spent at the shelter. These findings will allow shelters to focus behavioral modification efforts only on behaviors likely to influence adopters' choices. PMID:25551460

Effects of different substrates on the sprint performance of lizards.

PubMed

Tulli, Maria Jose; Abdala, Virginia; Cruz, Felix B

2012-03-01

The variation in substrate structure is one of the most important determinants of the locomotor abilities of lizards. Lizards are found across a range of habitats, from large rocks to loose sand, each of them with conflicting mechanical demands on locomotion. We examined the relationships among sprint speed, morphology and different types of substrate surfaces in species of lizards that exploit different structural habitats (arboreal, saxicolous, terrestrial and arenicolous) in a phylogenetic context. Our main goals were to assess which processes drive variability in morphology (i.e. phylogeny or adaptation to habitat) in order to understand how substrate structure affects sprint speed in species occupying different habitats and to determine the relationship between morphology and performance. Liolaemini lizards show that most morphological traits are constrained by phylogeny, particularly toe 3, the femur and foot. All ecological groups showed significant differences on rocky surfaces. Surprisingly, no ecological group performed better on the surface resembling its own habitat. Moreover, all groups exhibited significant differences in sprint speed among the three different types of experimental substrates and showed the best performance on sand, with the exception of the arboreal group. Despite the fact that species use different types of habitats, the highly conservative morphology of Liolaemini species and the similar levels of performance on different types of substrates suggest that they confer to the 'jack of all trades and master of none' principle.

[cAMP mediates the morphological change of cultured olfactory ensheathing cells induced by serum].

PubMed

Wang, Ying; Huang, Zhi-Hui

2011-02-25

Olfactory ensheathing cells (OECs) are a unique type of glia with common properties of astrocyte and Schwann cells. Cultured OECs have two morphological phenotypes, astrocyte-like OECs and Schwann cell-like OECs. Reversible changes have been found between these two morphological phenotypes. However, the molecular mechanism underlying the regulation of these reversible changes is still unknown. The aim of this paper is to establish a method for the morphology plasticity of cultured OECs, and investigate the underlying mechanism. Using the primary culture of OECs and immunocytochemistry, the morphology of OECs was observed under serum, serum free media or dB-cAMP drug treatment. Statistical analysis was performed to test differences among the percentages of OEC subtypes under these conditions. The results showed that under serum free media, (95.2±3.7)% of OECs showed Schwann cell-like morphology, and (4.8±3.7)% of OECs showed astrocyte-like morphology; however, under 10% serum media, (42.5±10.4)% of OECs exhibited Schwann cell-like morphology, and (57.5±10.4)% of OECs exhibited astrocyte-like morphology. When media was changed back to serum free media for 24 h, (94.8±5.0)% of OECs showed Schwann cell-like morphology, and (5.2±5.0)% of OECs showed astrocyte-like morphology. Furthermore, culture condition with or without serum did not affect the expression of OEC cell marker, p-75 and S-100. Finally, dB-cAMP, an analog of cAMP, through inhibiting the formation of F-actin stress fibers and focal adhesion, induced the morphology switch from astrocyte-like to Schwann cell-like morphology under serum condition, promoted the branches and the growth of processes. These results suggest that serum induces the morphology plasticity of cultured OECs, which is mediated by cytoplasmic cAMP level through regulating the formation of F-actin stress fibers and focal adhesion.

Beneath the Surface: Understanding Patterns of Intra-Domain Orientational Order

NASA Astrophysics Data System (ADS)

Prasad, Ishan; Seo, Youngmi; Hall, Lisa; Grason, Gregory

Block copolymers (BCP) self assemble into a rich spectrum of ordered phases due to asymmetry in copolymer architecture. Despite extensive study of spatially-ordered composition patterns of BCP, knowledge of orientational order of chain segments that underlie these spatial patterns is evidently missing. We show using self consistent field (SCF) theory and coarse-grained molecular dynamics (MD) simulations that, even without explicit orientational interactions between segments, BCP exhibit generic patterns of intra-domain segment orientation, which vary both within a given morphology and from morphology to morphology. We find that segment alignment is usually both normal and parallel to the interface within different local regions of a BCP sub-domain. We describe principles that control relative strength and directionality of alignment in different morphologies and report a surprising yet generic emergence of biaxial segment order in morphologies with anisotropic curved interfaces, such as cylinders and gyroid phases. Finally, we focus our study on cholesteric textures that pervade mesochiral BCP morphologies, specifically alternating double gyroid (aDG) and helical cylinder (H*) phases, and analyze patterns of twisted (nematic and polar) segment order within these domains.

A morphological and electrophysiological study on the postnatal development of oligodendrocyte precursor cells in the rat brain.

PubMed

Chen, Peng-hui; Cai, Wen-qin; Wang, Li-yan; Deng, Qi-yue

2008-12-03

A widespread population of cells in CNS is identified by specific expression of the NG2 chondroitin sulphate proteoglycan and named as oligodendrocyte precursor cell (OPC). OPCs may possess stem cell-like characteristics, including multipotentiality in vitro and in vivo. It was proposed that OPCs in the CNS parenchyma comprise a unique population of glia, distinct from oligodendrocytes and astrocytes. This study confirmed that NG2 immunoreactive OPCs were continuously distributed in cerebral cortex and hippocampus during different postnatal developmental stages. These cells rapidly increased in number over the postnatal 7 days and migrate extensively to populate with abundant processes both in developing cortex and hippocampus. The morphology of OPCs exhibited extremely complex changes with the distribution of long distance primary process gradually increased from neonatal to adult CNS. Immunohistochemical studies showed that OPCs exhibited the morphological properties that can be distinguished from astrocytes. The electrophysiological properties showed that OPCs expressed a small amount of inward Na(+) currents which was distinguished from Na(+) currents in neurons owing to their lower Na-to-K conductance ratio and higher command voltage step depolarized maximum Na(+) current amplitude. These observations suggest that OPCs can be identified as the third type of macroglia because of their distribution in the CNS, the morphological development in process diversity and the electrophysiological difference from astrocyte.

The effects of a skeletal muscle titin mutation on walking in mice.

PubMed

Pace, Cinnamon M; Mortimer, Sarah; Monroy, Jenna A; Nishikawa, Kiisa C

2017-01-01

Titin contributes to sarcomere assembly, muscle signaling, and mechanical properties of muscle. The mdm mouse exhibits a small deletion in the titin gene resulting in dystrophic mutants and phenotypically normal heterozygotes. We examined the effects of this mutation on locomotion to assess how, and if, changes to muscle phenotype explain observed locomotor differences. Mutant mice are much smaller in size than their siblings and gait abnormalities may be driven by differences in limb proportions and/or by changes to muscle phenotype caused by the titin mutation. We quantified differences in walking gait among mdm genotypes and also determined whether genotypes vary in limb morphometrics. Mice were filmed walking, and kinematic and morphological variables were measured. Mutant mice had a smaller range of motion at the ankle, shorter stride lengths, and shorter stance duration, but walked at the same relative speeds as the other genotypes. Although phenotypically similar to wildtype mice, heterozygous mice frequently exhibited intermediate gait mechanics. Morphological differences among genotypes in hindlimb proportions were small and do not explain the locomotor differences. We suggest that differences in locomotion among mdm genotypes are due to changes in muscle phenotype caused by the titin mutation.

Two stable variants of Burkholderia pseudomallei strain MSHR5848 express broadly divergent in vitro phenotypes associated with their virulence differences.

PubMed

Shea, A A; Bernhards, R C; Cote, C K; Chase, C J; Koehler, J W; Klimko, C P; Ladner, J T; Rozak, D A; Wolcott, M J; Fetterer, D P; Kern, S J; Koroleva, G I; Lovett, S P; Palacios, G F; Toothman, R G; Bozue, J A; Worsham, P L; Welkos, S L

2017-01-01

Burkholderia pseudomallei (Bp), the agent of melioidosis, causes disease ranging from acute and rapidly fatal to protracted and chronic. Bp is highly infectious by aerosol, can cause severe disease with nonspecific symptoms, and is naturally resistant to multiple antibiotics. However, no vaccine exists. Unlike many Bp strains, which exhibit random variability in traits such as colony morphology, Bp strain MSHR5848 exhibited two distinct and relatively stable colony morphologies on sheep blood agar plates: a smooth, glossy, pale yellow colony and a flat, rough, white colony. Passage of the two variants, designated "Smooth" and "Rough", under standard laboratory conditions produced cultures composed of > 99.9% of the single corresponding type; however, both could switch to the other type at different frequencies when incubated in certain nutritionally stringent or stressful growth conditions. These MSHR5848 derivatives were extensively characterized to identify variant-associated differences. Microscopic and colony morphology differences on six differential media were observed and only the Rough variant metabolized sugars in selective agar. Antimicrobial susceptibilities and lipopolysaccharide (LPS) features were characterized and phenotype microarray profiles revealed distinct metabolic and susceptibility disparities between the variants. Results using the phenotype microarray system narrowed the 1,920 substrates to a subset which differentiated the two variants. Smooth grew more rapidly in vitro than Rough, yet the latter exhibited a nearly 10-fold lower lethal dose for mice than Smooth. Finally, the Smooth variant was phagocytosed and replicated to a greater extent and was more cytotoxic than Rough in macrophages. In contrast, multiple locus sequence type (MLST) analysis, ribotyping, and whole genome sequence analysis demonstrated the variants' genetic conservation; only a single consistent genetic difference between the two was identified for further study. These distinct differences shown by two variants of a Bp strain will be leveraged to better understand the mechanism of Bp phenotypic variability and to possibly identify in vitro markers of infection.

Comparison of stem morphology and anatomy of two alfalfa clonal lines exhibiting divergent cell wall composition.

PubMed

Gronwald, John W; Bucciarelli, Bruna

2013-08-30

In previous research, two alfalfa clonal lines (252 and 1283) were identified that exhibited environmentally stable differences in stem cell walls. Compared with stems of 1283, stems of 252 have a higher cell wall concentration and greater amounts of lignin and cellulose but reduced levels of pectic sugar residues. These results suggest greater deposition of secondary xylem and a reduction in pith in stems of 252 compared with 1283. The stem morphology and anatomy of first-cut and second-cut harvests of field-grown 1283 and 252 were examined. For both harvests, stems of 1283 were thicker and had a higher leaf/stem ratio compared with stems of 252. Stem cross-sections of both genotypes were stained for lignin, and the proportions of stem area that were pith and secondary xylem were measured using ImageJ. Stems of 252 exhibited greater deposition of secondary xylem and a reduction in pith proportion compared with stems of 1283 for the first-cut harvest, but this difference was not statistically significant for the second-cut harvest. The results indicate that the proportions of secondary xylem and pith are not environmentally stable in these two genotypes and hence cannot be the sole basis for the differences in cell wall concentration/composition. © 2012 Society of Chemical Industry.

Morphomechanics of bacterial biofilms undergoing anisotropic differential growth

NASA Astrophysics Data System (ADS)

Zhang, Cheng; Li, Bo; Huang, Xiao; Ni, Yong; Feng, Xi-Qiao

2016-10-01

Growing bacterial biofilms exhibit a number of surface morphologies, e.g., concentric wrinkles, radial ridges, and labyrinthine networks, depending on their physiological status and nutrient access. We explore the mechanisms underlying the emergence of these greatly different morphologies. Ginzburg-Landau kinetic method and Fourier spectral method are integrated to simulate the morphological evolution of bacterial biofilms. It is shown that the morphological instability of biofilms is triggered by the stresses induced by anisotropic and heterogeneous bacterial expansion, and involves the competition between membrane energy and bending energy. Local interfacial delamination further enriches the morphologies of biofilms. Phase diagrams are established to reveal how the anisotropy and spatial heterogeneity of growth modulate the surface patterns. The mechanics of three-dimensional microbial morphogenesis may also underpin self-organization in other development systems and provide a potential strategy for engineering microscopic structures from bacterial aggregates.

Darwin's naturalization hypothesis up-close: Intermountain grassland invaders differ morphologically and phenologically from native community dominants

Treesearch

Dean E. Pearson; Yvette K. Ortega; Samantha J. Sears

2012-01-01

Darwin's naturalization hypothesis predicts that successful invaders will tend to differ taxonomically from native species in recipient communities because less related species exhibit lower niche overlap and experience reduced biotic resistance. This hypothesis has garnered substantial support at coarse scales. However, at finer scales, the influence of traits...

Quantifying the abnormal hemodynamics of sickle cell anemia

NASA Astrophysics Data System (ADS)

Lei, Huan; Karniadakis, George

2012-02-01

Sickle red blood cells (SS-RBC) exhibit heterogeneous morphologies and abnormal hemodynamics in deoxygenated states. A multi-scale model for SS-RBC is developed based on the Dissipative Particle Dynamics (DPD) method. Different cell morphologies (sickle, granular, elongated shapes) typically observed in deoxygenated states are constructed and quantified by the Asphericity and Elliptical shape factors. The hemodynamics of SS-RBC suspensions is studied in both shear and pipe flow systems. The flow resistance obtained from both systems exhibits a larger value than the healthy blood flow due to the abnormal cell properties. Moreover, SS-RBCs exhibit abnormal adhesive interactions with both the vessel endothelium cells and the leukocytes. The effect of the abnormal adhesive interactions on the hemodynamics of sickle blood is investigated using the current model. It is found that both the SS-RBC - endothelium and the SS-RBC - leukocytes interactions, can potentially trigger the vicious ``sickling and entrapment'' cycles, resulting in vaso-occlusion phenomena widely observed in micro-circulation experiments.

The influences of shape and structure of MnO2 nanomaterials over the non-enzymatic sensing ability of hydrogen peroxide

NASA Astrophysics Data System (ADS)

Babu, K. Justice; Zahoor, Awan; Nahm, Kee Suk; Ramachandran, R.; Rajan, M. A. Jothi; Gnana kumar, G.

2014-02-01

The different morphologies of MnO2 nanomaterials such as rod, belt, and flower were synthesized through a facile hydrothermal method, and their phases were also effectively controlled without employing any organic surfactants. The growth mechanisms of prepared nanostructures has been rationalized through the observed morphologic and structural characterizations. The prepared MnO2 nanostructures improved the electron transfer kinetics and minimized the overpotential and exhibited good electrocatalytic activities in detecting the hydrogen peroxide. Among the studied nanostructures, r-MnO2 exhibited an excellent sensing behavior toward hydrogen peroxide, and a linear current response was observed for the hydrogen peroxide, ranging from 1 micromolar to 1.5 mM with a high-sensitivity and low-level detection limit of 62.9 μAmM-1 cm-2 and 0.1 μM, respectively. Moreover, r-MnO2-modified electrode exhibited high selectivity toward hydrogen peroxide and interference-free phenomenon for the other electroactive species.

Martian impact craters - Correlations of ejecta and interior morphologies with diameter, latitude, and terrain

NASA Technical Reports Server (NTRS)

Barlow, Nadine G.; Bradley, Tracy L.

1990-01-01

An effort is made to establish the ability of a correlation between crater morphology and latitude, diameter, and terrain, to discriminate among the effects of impact energy, atmosphere, and subsurface volatiles in 3819 larger-than-8 km diameter craters distributed over the Martian surface. It is noted that changes in ejecta and interior morphology correlate with increases in crater diameter, and that while many of the interior structures exhibit distributions interpretable as terrain-dependent, central peak and peak ring interior morphologies exhibit minimal relationships with planetary properties.

Nanomechanical properties of distinct fibrillar polymorphs of the protein α-synuclein.

PubMed

Makky, Ali; Bousset, Luc; Polesel-Maris, Jérôme; Melki, Ronald

2016-11-30

Alpha-synuclein (α-Syn) is a small presynaptic protein of 140 amino acids. Its pathologic intracellular aggregation within the central nervous system yields protein fibrillar inclusions named Lewy bodies that are the hallmarks of Parkinson's disease (PD). In solution, pure α-Syn adopts an intrinsically disordered structure and assembles into fibrils that exhibit considerable morphological heterogeneity depending on their assembly conditions. We recently established tightly controlled experimental conditions allowing the assembly of α-Syn into highly homogeneous and pure polymorphs. The latter exhibited differences in their shape, their structure but also in their functional properties. We have conducted an AFM study at high resolution and performed a statistical analysis of fibrillar α-Syn shape and thermal fluctuations to calculate the persistence length to further assess the nanomechanical properties of α-Syn polymorphs. Herein, we demonstrated quantitatively that distinct polymorphs made of the same protein (wild-type α-Syn) show significant differences in their morphology (height, width and periodicity) and physical properties (persistence length, bending rigidity and axial Young's modulus).

Nanomechanical properties of distinct fibrillar polymorphs of the protein α-synuclein

NASA Astrophysics Data System (ADS)

Makky, Ali; Bousset, Luc; Polesel-Maris, Jérôme; Melki, Ronald

2016-11-01

Alpha-synuclein (α-Syn) is a small presynaptic protein of 140 amino acids. Its pathologic intracellular aggregation within the central nervous system yields protein fibrillar inclusions named Lewy bodies that are the hallmarks of Parkinson’s disease (PD). In solution, pure α-Syn adopts an intrinsically disordered structure and assembles into fibrils that exhibit considerable morphological heterogeneity depending on their assembly conditions. We recently established tightly controlled experimental conditions allowing the assembly of α-Syn into highly homogeneous and pure polymorphs. The latter exhibited differences in their shape, their structure but also in their functional properties. We have conducted an AFM study at high resolution and performed a statistical analysis of fibrillar α-Syn shape and thermal fluctuations to calculate the persistence length to further assess the nanomechanical properties of α-Syn polymorphs. Herein, we demonstrated quantitatively that distinct polymorphs made of the same protein (wild-type α-Syn) show significant differences in their morphology (height, width and periodicity) and physical properties (persistence length, bending rigidity and axial Young’s modulus).

Insights into Penicillium roqueforti Morphological and Genetic Diversity

PubMed Central

Gillot, Guillaume; Jany, Jean-Luc; Coton, Monika; Le Floch, Gaétan; Debaets, Stella; Ropars, Jeanne; López-Villavicencio, Manuela; Dupont, Joëlle; Branca, Antoine; Giraud, Tatiana; Coton, Emmanuel

2015-01-01

Fungi exhibit substantial morphological and genetic diversity, often associated with cryptic species differing in ecological niches. Penicillium roqueforti is used as a starter culture for blue-veined cheeses, being responsible for their flavor and color, but is also a common spoilage organism in various foods. Different types of blue-veined cheeses are manufactured and consumed worldwide, displaying specific organoleptic properties. These features may be due to the different manufacturing methods and/or to the specific P. roqueforti strains used. Substantial morphological diversity exists within P. roqueforti and, although not taxonomically valid, several technological names have been used for strains on different cheeses (e.g., P. gorgonzolae, P. stilton). A worldwide P. roqueforti collection from 120 individual blue-veined cheeses and 21 other substrates was analyzed here to determine (i) whether P. roqueforti is a complex of cryptic species, by applying the Genealogical Concordance Phylogenetic Species Recognition criterion (GC-PSR), (ii) whether the population structure assessed using microsatellite markers correspond to blue cheese types, and (iii) whether the genetic clusters display different morphologies. GC-PSR multi-locus sequence analyses showed no evidence of cryptic species. The population structure analysis using microsatellites revealed the existence of highly differentiated populations, corresponding to blue cheese types and with contrasted morphologies. This suggests that the population structure has been shaped by different cheese-making processes or that different populations were recruited for different cheese types. Cheese-making fungi thus constitute good models for studying fungal diversification under recent selection. PMID:26091176

A morphological and life history comparison between desert populations of a sit-and-pursue antlion, in reference to a co-occurring pit-building antlion.

PubMed

Scharf, Inon; Filin, Ido; Subach, Aziz; Ovadia, Ofer

2009-10-01

Although most antlion species do not construct pits, the vast majority of studies on antlions focused on pit-building species. We report here on a transplant experiment aiming to test for morphological and life history differences between two desert populations of a sit-and-pursue antlion species, Lopezus fedtschenkoi (Neuroptera: Myrmeleontidae), originating from habitats, which mainly differ in plant cover and productivity. We raised the antlion larvae in environmental chambers simulating either hyper-arid or Mediterranean climate. We found significant differences in the morphology and life history of L. fedtschenkoi larvae between the two populations. For example, the larvae originating from the more productive habitat pupated faster and had a higher growth rate. In agreement with the temperature-size rule, antlions reached higher final mass in the colder Mediterranean climate and exhibited a higher growth rate, but there was no difference in their developmental time. Observed differences in morphology between populations as well as those triggered by climate growing conditions could be explained by differences in size allometry. We also provide a quantitative description of the allometric growth axis, based on 12 morphological traits. Comparing the responses of L. fedtschenkoi with those observed in a co-occurring pit-building antlion indicated that there were neither shape differences that are independent of size nor was there a difference in the plasticity level between the two species.

Sex-specific differences in mitochondria biogenesis, morphology, respiratory function, and ROS homeostasis in young mouse heart and brain.

PubMed

Khalifa, Abdel Rahman M; Abdel-Rahman, Engy A; Mahmoud, Ali M; Ali, Mohamed H; Noureldin, Maha; Saber, Saber H; Mohsen, Mahmoud; Ali, Sameh S

2017-03-01

Sex-specific differences in mitochondrial function and free radical homeostasis are reported in the context of aging but not well-established in pathogeneses occurring early in life. Here, we examine if sex disparity in mitochondria function, morphology, and redox status starts early and hence can be implicated in sexual dimorphism in cardiac as well as neurological disorders prevalent at young age. Although mitochondrial activity in the heart did not significantly vary between sexes, female brain exhibited enhanced respiration and higher reserve capacity. This was associated with lower H 2 O 2 production in female cardiac and brain tissues. Using transmission electron microscopy, we found that the number of female cardiac mitochondria is moderately greater (117 ± 3%, P  = 0.049, N  = 4) than male's, which increased significantly for cortical mitochondria (134 ± 4%, P  = 0.001, N  = 4). However, male's cardiac mitochondria exhibited fragmented, circular, and smaller mitochondria relative to female's mitochondria, while no morphologic sex-dependent differences were observed in cortical mitochondria. No sex differences were detected in Nox2 and Nox4 proteins or O 2 -consuming/H 2 O 2 -producing activities in brain homogenate or synaptosomes. However, a strong trend of increased EPR-detected NOX superoxide in male synaptosomes hinted at higher superoxide dismutase activity in female brains, which was confirmed by two independent protocols. We also provide direct evidence that respiring mitochondria generally produce an order-of-magnitude lower reactive oxygen species (ROS) proportions than currently estimated. Our results indicate that sex differences in mitochondrial biogenesis, bioenergetics, and morphology may start at young age and that sex-dependent SOD capacity may be responsible for differences in ROS homeostasis in heart and brain. © 2017 The Authors. Physiological Reports published by Wiley Periodicals, Inc. on behalf of The Physiological Society and the American Physiological Society.

Morphology-controlled synthesis of α-Fe 2O 3 nanostructures with magnetic property and excellent electrocatalytic activity for H 2O 2

NASA Astrophysics Data System (ADS)

Li, Xiyan; Lei, Yongqian; Li, Xiaona; Song, Shuyan; Wang, Cheng; Zhang, Hongjie

2011-12-01

α-Fe 2O 3 nanocrystals (NCs) with different morphologies are successfully synthesized via a facile template-free hydrothermal route. By simply changing the volume ratio of ethanol to water, we obtained three different α-Fe 2O 3 nanostructures of rhombohedra, truncated rhombohedra and hexagonal sheet. The morphologies and structures of the as-obtained products have been confirmed by varieties of characterizations such as X-ray diffraction (XRD), X-ray photoelectron spectrometry (XPS), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The influences of the experimental conditions, such as the amount of NaOH and reaction temperature on the morphologies of the as-prepared α-Fe 2O 3 NCs, have been well investigated. Additionally, magnetic investigations show that the as-obtained α-Fe 2O 3 nanostructures show structure-dependent magnetic properties. Furthermore, the electrochemical experiments indicate that the as-prepared α-Fe 2O 3 hexagonal sheets exhibit strong electrocatalytic reduction activity for H 2O 2.

Investigation of Synthesis and Magnetic Properties of Rod-Shaped CoFe2O4 via Precipitation-Topotactic Reaction Employing α-FeOOH and γ-FeOOH As Templates

NASA Astrophysics Data System (ADS)

Cao, Xiaohui; Dong, Hongfei; Tan, Yuzhuo; Meng, Jinhong

2018-03-01

Rod-shaped CoFe2O4 was prepared by chemical precipitation-topotactic reaction method, and in this preparation needle-like γ-FeOOH and α-FeOOH were synthesized to use as template materials. The evolution of phase and morphology in the process of calcination exhibits that α-FeOOH and γ-FeOOH experienced different routes to form the α-Fe2O3 middle phase with different crystallinity and morphology. The synthesis process of CoFe2O4 revealed that the crystallinity, purity and morphology of CoFe2O4 depend on the α-Fe2O3 middle phase. The magnetic measurement showed that the CoFe2O4 prepared from α-FeOOH has higher saturation magnetization and coercivity, and the crystallinity and morphology may play important roles in achieving a better magnetic performance.

Correlated evolution of body and fin morphology in the cichlid fishes.

PubMed

Feilich, Kara L

2016-10-01

Body and fin shapes are chief determinants of swimming performance in fishes. Different configurations of body and fin shapes can suit different locomotor specializations. The success of any configuration is dependent upon the hydrodynamic interactions between body and fins. Despite the importance of body-fin interactions for swimming, there are few data indicating whether body and fin configurations evolve in concert, or whether these structures vary independently. The cichlid fishes are a diverse family whose well-studied phylogenetic relationships make them ideal for the study of macroevolution of ecomorphology. This study measured body, and caudal and median fin morphology from radiographs of 131 cichlid genera, using morphometrics and phylogenetic comparative methods to determine whether these traits exhibit correlated evolution. Partial least squares canonical analysis revealed that body, caudal fin, dorsal fin, and anal fin shapes all exhibited strong correlated evolution consistent with locomotor ecomorphology. Major patterns included the evolution of deep body profiles with long fins, suggestive of maneuvering specialization; and the evolution of narrow, elongate caudal peduncles with concave tails, a combination that characterizes economical cruisers. These results demonstrate that body shape evolution does not occur independently of other traits, but among a suite of other morphological changes that augment locomotor specialization. © 2016 The Author(s). Evolution © 2016 The Society for the Study of Evolution.

Application of morphologic burrow interpretations to discern continental burrow architects: Lungfish or crayfish?

USGS Publications Warehouse

Hasiotis, Stephen T.; Mitchell, Charles E.; Dubiel, Russell R.

1993-01-01

A methodology for trace fossil identification using burrowing signatures is tested by evaluating ancient and modern lungfish and crayfish burrows and comparing them to previously undescribed burrows in a stratigraphic interval thought to contain both lungfish and crayfish burrows. Permian burrows that bear skeletal remains of the lungfish Gnathorhiza, from museum collections, were evaluated to identify unique burrow morphologies that could be used to distinguish lungfish from crayfish burrows when fossil remains are absent. The lungfish burrows were evaluated for details of the burrowing mechanism preserved in the burrow morphologies together forming burrowing signatures and were compared to new burrows in the Chinle Formation of western Colorado to test the methodology of using burrow signatures to identify unknown burrows.Permian lungfish aestivation burrows show simple, nearly vertical, unbranched architectures and relatively smooth surficial morphologies with characteristic quasi‐horizontal striae on the burrow walls and vertical striae on the bulbous terminus. Burrow lengths do not exceed 0.5 m. In contrast, modern and ancient crayfish burrows exhibit simple to highly complex architectures with highly textured surficial morphologies. Burrow lengths may reach 4 to 5 m.Burrow morphologies unlike those identified in Gnathorhiza aestivation burrows were found in four burrow groups from museum collections. Two of these groups exhibit simple architectures and horizontal striae that were greater in sinuosity and magnitude, respectively. One of these burrows contains the remains of Lysoro‐phus, but the burrow surface reveals no reliable surficial characteristics. It is not clear whether Lysorophustruly burrowed or merely occupied a pre‐existing structure. The other two groups exhibit surficial morphologies similar to those found on modern and ancient crayfish burrows and may provide evidence of freshwater crayfish in the Permian.Burrows from the Upper Triassic Chinle Formation in western Colorado exhibit simple to moderately complex architectural morphologies, ranging from predominantly vertical, unbranched, with little or no chamber development to predominantly vertical, few branches, and with minor chamber development. Surficial burrow morphologies are moderate to highly textured. The burrows have scrape marks, scratch marks, mud and lag‐liners, knobby surfaces, pleopod striae, and body impressions.Although no fossil remains of the burrowing organism were found within or associated with the Chinle burrows from western Colorado, the similarity of architectural and surficial burrow morphologies to those in the Chinle of Canyonlands, Utah and to modern crayfish burrows, clearly indicates that the Colorado burrows are the product of burrowing crayfish rather than lungfish. Evaluation of burrowing signatures preserved in the architectural and surficial burrow morphologies is a very useful tool to compare and contrast Chinle burrows from different regions on the Colorado Plateau. Documentation of crayfish burrows in the Chinle of Utah and Colorado strongly suggests that other large‐diameter Chinle burrows elsewhere on the Colorado Plateau and in stratigraphically equivalent units may also be the product of crayfish activity.

The evolution of floral nectaries in Disa (Orchidaceae: Disinae): recapitulation or diversifying innovation?

PubMed

Hobbhahn, Nina; Johnson, Steven D; Bytebier, Benny; Yeung, Edward C; Harder, Lawrence D

2013-11-01

The Orchidaceae have a history of recurring convergent evolution in floral function as nectar production has evolved repeatedly from an ancestral nectarless state. However, orchids exhibit considerable diversity in nectary type, position and morphology, indicating that this convergence arose from alternative adaptive solutions. Using the genus Disa, this study asks whether repeated evolution of floral nectaries involved recapitulation of the same nectary type or diversifying innovation. Epidermis morphology of closely related nectar-producing and nectarless species is also compared in order to identify histological changes that accompanied the gain or loss of nectar production. The micromorphology of nectaries and positionally equivalent tissues in nectarless species was examined with light and scanning electron microscopy. This information was subjected to phylogenetic analyses to reconstruct nectary evolution and compare characteristics of nectar-producing and nectarless species. Two nectary types evolved in Disa. Nectar exudation by modified stomata in floral spurs evolved twice, whereas exudation by a secretory epidermis evolved six times in different perianth segments. The spur epidermis of nectarless species exhibited considerable micromorphological variation, including strongly textured surfaces and non-secreting stomata in some species. Epidermis morphology of nectar-producing species did not differ consistently from that of rewardless species at the magnifications used in this study, suggesting that transitions from rewardlessness to nectar production are not necessarily accompanied by visible morphological changes but only require sub-cellular modification. Independent nectary evolution in Disa involved both repeated recapitulation of secretory epidermis, which is present in the sister genus Brownleea, and innovation of stomatal nectaries. These contrasting nectary types and positional diversity within types imply weak genetic, developmental or physiological constraints in ancestral, nectarless Disa. Such functional convergence generated by morphologically diverse solutions probably also underlies the extensive diversity of nectary types and positions in the Orchidaceae.

A simple and rapid method for preparing the whole section of starchy seed to investigate the morphology and distribution of starch in different regions of seed.

PubMed

Zhao, Lingxiao; Pan, Ting; Guo, Dongwei; Wei, Cunxu

2018-01-01

Storage starch in starchy seed influences the seed weight and texture, and determines its applications in food and nonfood industries. Starch granules from different plant sources have significantly different shapes and sizes, and even more the difference exists in the different regions of the same tissue. Therefore, it is very important to in situ investigate the morphology and distribution of starch in the whole seed. However, a simple and rapid method is deficient to prepare the whole section of starchy seed for investigating the morphology and distribution of starch in the whole seeds for a large number of samples. A simple and rapid method was established to prepare the whole section of starchy seed, especially for floury seed, in this study. The whole seeds of translucent and chalky rice, vitreous and floury maize, and normal barley and wheat were sectioned successfully using the newly established method. The iodine-stained section clearly exhibited the shapes and size of starch granules in different regions of seed. The starch granules with different morphologies and iodine-staining colors existed regionally in the seeds of high-amylose rice and maize. The sections of lotus and kidney bean seeds also showed the feasibility of this method for starchy non-cereal seeds. The simple and rapid method was proven effective for preparing the whole sections of starchy seeds. The whole section of seed could be used to investigate the morphology and distribution of starch granules in different regions of the whole seed. The method was especially suitable for large sample numbers to investigate the starch morphology in short time.

Exophiala pisciphila. A study of its development.

PubMed

Gaskins, J E; Cheung, P J

1986-03-01

Exophiala pisciphila is a dematiaceous fungus that belongs to a group of fungi known as the 'black yeasts'. It was isolated from the skin lesions of a smooth dogfish, Mustelus canis Mitchill, that had been born in the shark exhibit tank of the New York Aquarium. The different stages of development of this fungus were studied by light microscopy and scanning electron microscopy to illustrate the morphology and surface structures of conidia and mycelium. The list of marine and fresh water fish, which have been infected by Exophiala spp. and Exophiala-like fungi has been up-dated. Potato Dextrose Agar and Malt Agar proved to be the best growth media, while Corn Meal Agar proved to be the best medium for studying the morphological features of the conidia and mycelial development of E. pisciphila, which exhibited polymorphic conidiogenesis.

STXM/C 1s-NEXAFS study of Eu(III) and Uranyl humic acid aggregates at different pH

NASA Astrophysics Data System (ADS)

Plaschke, M.; Rothe, J.; Denecke, M. A.; Geckeis, H.

2010-04-01

Humic acids (HA) are chemically heterogeneous and structurally ill-defined biopolymers which are able to bind traces of actinides or lanthanides. Due to their dimensions in the colloidal size range they may affect transport of these elements in aquatic systems. Eu(III)- and UO22+-HA aggregates have been investigated by Scanning Transmission X-ray Microscopy (STXM) and C 1s-NEXAFS under systematic variation of pH. In the Eu(III)- and UO22+-HA systems aggregate morphologies at near neutral pH were similar to those observed in previous studies: optically dense zones (high absorption at the carbon K-edge) are embedded in a matrix of less dense material. C 1s-NEXAFS signatures observed in the different zones, i.e., the intensity of the characteristic complexation feature previously experimentally described and recently theoretically characterized, strongly depends on sample pH. In the alkaline regime (pH 9) with added carbonate, co-precipitation of Eu(III)-carbonate (or ternary carbonate/(oxo)hydroxide complexes) with the Eu(III)-HA majority fraction is observed but Eu(III) binding to HA over carbonate in the dense zones seems to be favoured. The UO22+-HA system exhibits in alkaline solution more compact morphologies combined with a strong metal ion complexation effect in the NEXAFS. Eu(III) and UO22+ polyacrylic acid (PAA) aggregates used as HA model systems show similar spectral trends; these aggregates exhibit highly branched morphologies without segregation into zones with different NEXAFS signatures. The chemical environment such as pH or the type of metal cation strongly influences both HA aggregate morphologies and NEXAFS spectral signatures. These can, in turn, be used as indicators of the strength of lanthanide or actinide ion bound HA interaction.

Neurogenic and cardiomyogenic differentiation of mesenchymal stem cells isolated from minipig bone marrow.

PubMed

Kumar, B Mohana; Maeng, Geun-Ho; Lee, Yeon-Mi; Kim, Tae-Ho; Lee, Jeong-Hyeon; Jeon, Byeong-Gyun; Ock, Sun-A; Yoo, Jae-Gyu; Rho, Gyu-Jin

2012-10-01

The present study investigated the potential of minipig bone marrow-mesenchymal stem cells (BM-MSCs) to differentiate in vitro into neuron- and cardiomyocyte-like cells. Isolated BM-MSCs exhibited a fibroblast-like morphology, expressed CD29, CD44 and CD90, and differentiated into osteocytes, adipocytes and chondrocytes. Upon induction in two different neuronal specific media, most of BM-MSCs acquired the distinctive morphological features and positively stained for nestin, neurofilament-M (NF-M), neuronal nuclei (NeuN), β-tubulin, galactocerebroside (Gal-C) and glial fibrillary acidic protein (GFAP). Expression of nestin, GFAP and NF-M was further demonstrated by RT-PCR and RT-qPCR. Following cardiomyogenic induction, MSCs exhibited a stick-like morphology with extended cytoplasmic processes, and formed cluster-like structures. The expression of cardiac specific markers α-smooth muscle actin, cardiac troponin T, desmin and α-cardiac actin was positive for immunofluorescence staining, and further confirmed by RT-PCR and RT-qPCR. In conclusion, our results showed the in vitro differentiation ability of porcine BM-MSCs into neuron-like and cardiomyocyte-like cells. Copyright © 2011 Elsevier Ltd. All rights reserved.

Natural Genetic Variation and Candidate Genes for Morphological Traits in Drosophila melanogaster

PubMed Central

Carreira, Valeria Paula; Mensch, Julián; Hasson, Esteban; Fanara, Juan José

2016-01-01

Body size is a complex character associated to several fitness related traits that vary within and between species as a consequence of environmental and genetic factors. Latitudinal and altitudinal clines for different morphological traits have been described in several species of Drosophila and previous work identified genomic regions associated with such variation in D. melanogaster. However, the genetic factors that orchestrate morphological variation have been barely studied. Here, our main objective was to investigate genetic variation for different morphological traits associated to the second chromosome in natural populations of D. melanogaster along latitudinal and altitudinal gradients in Argentina. Our results revealed weak clinal signals and a strong population effect on morphological variation. Moreover, most pairwise comparisons between populations were significant. Our study also showed important within-population genetic variation, which must be associated to the second chromosome, as the lines are otherwise genetically identical. Next, we examined the contribution of different candidate genes to natural variation for these traits. We performed quantitative complementation tests using a battery of lines bearing mutated alleles at candidate genes located in the second chromosome and six second chromosome substitution lines derived from natural populations which exhibited divergent phenotypes. Results of complementation tests revealed that natural variation at all candidate genes studied, invected, Fasciclin 3, toucan, Reticulon-like1, jing and CG14478, affects the studied characters, suggesting that they are Quantitative Trait Genes for morphological traits. Finally, the phenotypic patterns observed suggest that different alleles of each gene might contribute to natural variation for morphological traits. However, non-additive effects cannot be ruled out, as wild-derived strains differ at myriads of second chromosome loci that may interact epistatically with mutant alleles. PMID:27459710

Starvation stress during larval development reveals predictive adaptive response in adult worker honey bees (Apis mellifera)

USDA-ARS?s Scientific Manuscript database

A variety of organisms exhibit developmental plasticity that results in differences in adult morphology, physiology or behavior. This variation in the phenotype, called “Predictive Adaptive Response (PAR),” gives a selective advantage in an adult's environment if the adult experiences environments s...

Whole genome sequences of the raspberry and strawberry pathogens Phytophthora rubi and P. fragariae

USDA-ARS?s Scientific Manuscript database

Phytophthora rubi and P. fragariae are two closely related oomycete plant pathogens that exhibit strong morphological and physiological similarities, but are specialized to infect different hosts of economic importance, namely raspberry and strawberry. Here, we report the draft genome sequences of t...

Host-Specific Phenotypic Plasticity of the Turtle Barnacle Chelonibia testudinaria: A Widespread Generalist Rather than a Specialist

PubMed Central

Chu, Ka Hou; Cheng, I-Jiunn; Chan, Benny K. K.

2013-01-01

Turtle barnacles are common epibionts on marine organisms. Chelonibia testudinaria is specific on marine turtles whereas C. patula is a host generalist, but rarely found on turtles. It has been questioned why C. patula, being abundant on a variety of live substrata, is almost absent from turtles. We evaluated the genetic (mitochondrial COI, 16S and 12S rRNA, and amplified fragment length polymorphism (AFLP)) and morphological differentiation of C. testudinaia and C. patula from different hosts, to determine the mode of adaptation exhibited by Chelonibia species on different hosts. The two taxa demonstrate clear differences in shell morphology and length of 4–6th cirri, but very similar in arthropodal characters. Moreover, we detected no genetic differentiation in mitochondrial DNA and AFLP analyses. Outlier detection infers insignificant selection across loci investigated. Based on combined morphological and molecular evidence, we proposed that C. testudinaria and C. patula are conspecific, and the two morphs with contrasting shell morphologies and cirral length found on different host are predominantly shaped by developmental plasticity in response to environmental setting on different hosts. Chelonibia testudinaria is, thus, a successful general epibiotic fouler and the phenotypic responses postulated can increase the fitness of the animals when they attach on hosts with contrasting life-styles. PMID:23469208

Differences in Lateral Line Morphology between Hatchery- and Wild-Origin Steelhead

PubMed Central

Brown, Andrew D.; Sisneros, Joseph A.; Jurasin, Tyler; Nguyen, Chau; Coffin, Allison B.

2013-01-01

Despite identification of multiple factors mediating salmon survival, significant disparities in survival-to-adulthood among hatchery- versus wild-origin juveniles persist. In the present report, we explore the hypothesis that hatchery-reared juveniles might exhibit morphological defects in vulnerable mechanosensory systems prior to release from the hatchery, potentiating reduced survival after release. Juvenile steelhead (Oncorhynchus mykiss) from two different hatcheries were compared to wild-origin juveniles on several morphological traits including lateral line structure, otolith composition (a proxy for auditory function), and brain weight. Wild juveniles were found to possess significantly more superficial lateral line neuromasts than hatchery-reared juveniles, although the number of hair cells within individual neuromasts was not significantly different across groups. Wild juveniles were also found to possess primarily normal, aragonite-containing otoliths, while hatchery-reared juveniles possessed a high proportion of crystallized (vaterite) otoliths. Finally, wild juveniles were found to have significantly larger brains than hatchery-reared juveniles. These differences together predict reduced sensitivity to biologically important hydrodynamic and acoustic signals from natural biotic (predator, prey, conspecific) and abiotic (turbulent flow, current) sources among hatchery-reared steelhead, in turn predicting reduced survival fitness after release. Physiological and behavioral studies are required to establish the functional significance of these morphological differences. PMID:23554988

Feeding behavior, diet, and the functional consequences of jaw form in orangutans, with implications for the evolution of Pongo.

PubMed

Taylor, Andrea B

2006-04-01

Orangutans are amongst the most craniometrically variable of the extant great apes, yet there has been no attempt to explicitly link this morphological variation with observed differences in behavioral ecology. This study explores the relationship between feeding behavior, diet, and mandibular morphology in orangutans. All orangutans prefer ripe, pulpy fruit when available. However, some populations of Bornean orangutans (Pongo pygmaeus morio and P. p. wurmbii) rely more heavily on bark and relatively tough vegetation during periods of low fruit yield than do Sumatran orangutans (Pongo abelii). I tested the hypothesis that Bornean orangutans exhibit structural features of the mandible that provide greater load resistance abilities to masticatory and incisal forces. Compared to P. abelii, P. p. morio exhibits greater load resistance abilities as reflected in a relatively deeper mandibular corpus, deeper and wider mandibular symphysis, and relatively greater condylar area. P. p. wurmbii exhibits most of these same morphologies, and in all comparisons is either comparable in jaw proportions to P. p. morio, or intermediate between P. p. morio and P. abelii. These data indicate that P. p. morio and P. p. wurmbii are better suited to resisting large and/or frequent jaw loads than P. abelii. Using these results, I evaluated mandibular morphology in P. p. pygmaeus, a Bornean orangutan population whose behavioral ecology is poorly known. Pongo p. pygmaeus generally exhibits relatively greater load resistance capabilities than P. abelii, but less than P. p. morio. These results suggest that P. p. pygmaeus may consume greater amounts of tougher and/or more obdurate foods than P. abelii, and that consumption of such foods may intensify amongst Bornean orangutan populations. Finally, data from this study are used to evaluate variation in craniomandibular morphology in Khoratpithecus piriyai, possibly the earliest relative of Pongo from the late Miocene of Thailand, and the late Pleistocene Hoa Binh subfossil orangutan recovered from Vietnam. With the exception of a relatively thicker M(3) mandibular corpus, K. piriyai has jaw proportions that would be expected for an extant orangutan of comparable jaw size. Likewise, the Hoa Binh subfossil does not differ in skull proportions from extant Pongo, independent of the effects of increase in jaw size. These results indicate that differences in skull and mandibular proportions between these fossil and subfossil orangutans and extant Pongo are allometric. Furthermore, the ability of K. piriyai to resist jaw loads appears to have been comparable to that of extant orangutans. However, the similarity in jaw proportions between P. abelii and K. piriyai suggest the latter may have been dietarily more similar to Sumatran orangutans.

Crystallography and Morphology of Niobium Carbide in As-Cast HP-Niobium Reformer Tubes

NASA Astrophysics Data System (ADS)

Buchanan, Karl G.; Kral, Milo V.

2012-06-01

The microstructures of two as-cast heats of niobium-modified HP stainless steels were characterized. Particular attention was paid to the interdendritic niobium-rich carbides formed during solidification of these alloys. At low magnifications, these precipitates are grouped in colonies of similar lamellae. Higher magnifications revealed that the lamellae actually obtain two distinct morphologies. The type I morphology exhibits broad planar interfaces with a smooth platelike shape. Type II lamellae have undulating interfaces and an overall reticulated shape. To provide further insight into the origin of these two different morphologies, the microstructure and crystallography of each have been studied in detail using high resolution scanning electron microscopy, transmission electron microscopy, various electron diffraction methods (electron backscatter diffraction (EBSD), selected area diffraction (SAD), and convergent beam electron diffraction (CBED)), and energy dispersive X-ray spectroscopy.

Size and diet in the evolution of African ape craniodental form.

PubMed

Shea, B T

1983-01-01

Interspecific differences in craniodental morphology among Pan paniscus, Pan troglodytes, and Gorilla gorilla are analyzed. These apes differ in both diet and body size, and thus present an excellent example in which to apply an allometric criterion of subtraction in order to determine morphological differences which might be related to divergent dietary specialization. The use of ontogenetic allometry in particular as a criterion of subtraction is discussed. Bivariate and multivariate results indicate that most of the variation in skull form among the species relates to the extension of a common growth trend to different sizes. Comparative analysis of growth trajectories reveals a number of differences, but none that appear to relate to a reorganization of skull proportions which might correspond to a dietary shift towards increased folivory. The dentition clearly exhibits non-allometric shape changes corresponding to the dietary differences, however. The meaning of these differences between cranial and dental patterns is discussed.

Morphological analysis of Trichomycterus areolatus Valenciennes, 1846 from southern Chilean rivers using a truss-based system (Siluriformes, Trichomycteridae).

PubMed

Colihueque, Nelson; Corrales, Olga; Yáñez, Miguel

2017-01-01

Trichomycterus areolatus Valenciennes, 1846 is a small endemic catfish inhabiting the Andean river basins of Chile. In this study, the morphological variability of three T. areolatus populations, collected in two river basins from southern Chile, was assessed with multivariate analyses, including principal component analysis (PCA) and discriminant function analysis (DFA). It is hypothesized that populations must segregate morphologically from each other based on the river basin that they were sampled from, since each basin presents relatively particular hydrological characteristics. Significant morphological differences among the three populations were found with PCA (ANOSIM test, r = 0.552, p < 0.0001) and DFA (Wilks's λ = 0.036, p < 0.01). PCA accounted for a total variation of 56.16% by the first two principal components. The first Principal Component (PC1) and PC2 explained 34.72 and 21.44% of the total variation, respectively. The scatter-plot of the first two discriminant functions (DF1 on DF2) also validated the existence of three different populations. In group classification using DFA, 93.3% of the specimens were correctly-classified into their original populations. Of the total of 22 transformed truss measurements, 17 exhibited highly significant ( p < 0.01) differences among populations. The data support the existence of T. areolatus morphological variation across different rivers in southern Chile, likely reflecting the geographic isolation underlying population structure of the species.

Intrinsic physiological properties of rat retinal ganglion cells with a comparative analysis.

PubMed

Wong, Raymond C S; Cloherty, Shaun L; Ibbotson, Michael R; O'Brien, Brendan J

2012-10-01

Mammalian retina contains 15-20 different retinal ganglion cell (RGC) types, each of which is responsible for encoding different aspects of the visual scene. The encoding is defined by a combination of RGC synaptic inputs, the neurotransmitter systems used, and their intrinsic physiological properties. Each cell's intrinsic properties are defined by its morphology and membrane characteristics, including the complement and localization of the ion channels expressed. In this study, we examined the hypothesis that the intrinsic properties of individual RGC types are conserved among mammalian species. To do so, we measured the intrinsic properties of 16 morphologically defined rat RGC types and compared these data with cat RGC types. Our data demonstrate that in the rat different morphologically defined RGC types have distinct patterns of intrinsic properties. Variation in these properties across cell types was comparable to that found for cat RGC types. When presumed morphological homologs in rat and cat retina were compared directly, some RGC types had very similar properties. The rat A2 cell exhibited patterns of intrinsic properties nearly identical to the cat alpha cell. In contrast, rat D2 cells (ON-OFF directionally selective) had a very different pattern of intrinsic properties than the cat iota cell. Our data suggest that the intrinsic properties of RGCs with similar morphology and suspected visual function may be subject to variation due to the behavioral needs of the species.

Field-assisted organization, substrate effects and magnetic behavior of Ag 30Co 70 core-shell nanoparticles

NASA Astrophysics Data System (ADS)

Crisan, A. D.; Angelakeris, M.; Simeonidis, K.; Tsiaoussis, I.; Crisan, O.

2010-11-01

In core-shell systems with non-magnetic core and magnetic shell, the electron transport and magnetic properties are expected to show enhanced behavior due to the particular morpho-structural features of the conductive and magnetic regions. This may lead to novel advanced GMR materials and spin valves. This is the case of core-shell Ag-Co colloidal nanoscale particles that organize into regular arrays. An insight on the structure and morphology of the newly synthesized Ag-Co nanoparticles deposited on different substrates will be presented. The influence of the substrate on different morphologies and organization dynamics is discussed. It is shown that the magnetic behavior of the Ag-Co nanoparticles is highly influenced by the corona-like morphology of Co shell, chemical environment of the magnetic atoms and by the fact that they exhibit strongly reduced coordination due to the surface states.

The effects of deposition parameters on surface morphology and crystallographic orientation of electroless Ni-B coatings

NASA Astrophysics Data System (ADS)

Bulbul, Ferhat

2011-02-01

Electroless Ni-B coatings were deposited on AISI 304 stainless steels by electroless deposition method, which was performed for nine different test conditions at various levels of temperature, concentration of NaBH4, concentration of NiCl2, and time, using the Taguchi L9(34) experimental method. The effects of deposition parameters on the crystallographic orientation of electroless Ni-B coatings were investigated using SEM and XRD equipment. SEM analysis revealed that the Ni-B coatings developed six types (pea-like, maize-like, primary nodular, blackberry-like or grapes-like, broccoli-like, and cauliflower-like) of morphological structures depending on the deposition parameters. XRD results also showed that these structures exhibited different levels of amorphous character. The concentration of NaBH4 had the most dominant effect on the morphological and crystallographic development of electroless Ni-B coatings.

Albumin Evolution in Frogs: A Test of the Evolutionary Clock Hypothesis

PubMed Central

Wallace, Donald G.; Maxson, Linda R.; Wilson, Allan C.

1971-01-01

Frogs are an ancient group compared to placental mammals. Yet, although there are about as many species of frogs as there are of mammals, zoologists consider that frogs have undergone only limited morphological divergence, while placental mammals have diversified greatly in morphology and way of life. The serum albumins of numerous frog species were compared by the quantitative microcomplement fixation technique. Frogs that are morphologically similar enough to merit taxonomic distinction at only the species level often exhibit differences in the serological properties of their albumins larger than those usually seen between mammals placed in distinct families or suborders. Thus, there seems to be a contrast between albumin evolution and evolution at the organismal level. The large differences between albumins among frogs can be explained by the hypothesis that albumin evolution has proceeded at the same rate in frogs as in mammals. PMID:5002283

Impact of air pollution on floral morphology of Cassia siamea Lamk.

PubMed

Chauhan, S V S; Chaurasia, Bharati; Rana, Anita

2004-07-01

Cassia siamea plants growing at two different sites (polluted and non-polluted) on two important roads of Agra city exhibited significant differences in their flowering phenology and floral morphology. The flowering in plants growing at polluted site is delayed and there was a marked reduction in flowering density, flowering period, size of floral parts, pollen fertility, fruit and seed-set. SEM observations revealed the presence of well developed glandular structures and reduction in the number and size of large stomata on the anther surface at polluted site. These changes were found to be closely associated with the extent of air pollution caused mainly by significant in the number of automobiles.

The evolution of embryonic patterning mechanisms in animals

NASA Technical Reports Server (NTRS)

Wray, G. A.

2000-01-01

Animals exhibit an enormous diversity of life cycles and larval morphologies. The developmental basis for this diversity is not well understood. It is clear, however, that mechanisms of pattern formation in early embryos differ significantly among and within groups of animals. These differences show surprisingly little correlation with phylogenetic relationships; instead, many are correlated with ecological factors, such as changes in life histories. Copyright 2000 Academic Press.

Retro-action model for the erosion of rocky coasts

NASA Astrophysics Data System (ADS)

Sapoval, B.; Baldassarri, A.

2009-12-01

Rocky coasts are estimated to represent 75% of the world’s shorelines [1]. We discuss various situations where the formation of rocky coast morphology could be attributed to the retro-action of the coast morphology on the erosive power of the see. In the case of rocky coasts, erosion can spontaneously create irregular seashores. But, in turn, the geometrical irregularity participates to the damping of sea-waves, decreasing the average wave amplitude and erosive power. There may then exist a mutual self-stabilization of the waves amplitude together with the irregular morphology of the coast. A simple model of such stabilization is discussed. It leads, through a complex dynamics of the earth-sea interface, to the spontaneous appearance of an irregular sea-shore. The final coast morphology is found to depend on the morphology/damping coupling of the coast and on the possible existence of built-in correlations within the coast lithologic properties. This is illustrated in the figure. In the limit case where the morphology/damping coupling is weak and when the earth lithology distribution exhibit only short range correlations, the process spontaneously build fractal morphologies with a dimension close to 4/3 [2]. It is shown that this dimension refers to the dimension of the so-called accessible perimeter in gradient percolation. However, even rugged but non-fractal sea-coasts morphology may emerge for strong damping or during the erosion process. When the distributions of the lithologies exhibit long range correlations, a variety of complex morphologies are obtained which mimics observed coastline complexity, well beyond simple fractality. On a somewhat different perspective, the design of breakwaters is suggested to be improved by using global irregular geometry with features sizes of the order of the wave-length of the sea oscillations. [1] R. A. Davis, Jr, D. M. Fitzgerald, Beaches and Coasts,(Blackwell, Oxford 2004). [2] B. Sapoval, A. Baldassarri, A. Gabrielli, Self-stabilized Fractality of Sea-coasts through Erosion, Phys. Rev. Lett. 93, 098501 (2004). Time evolution of the coastline morphology starting with a flat sea-shore. Left and right columns correspond respectively to weak and strong coupling. Top to bottom: suc- cessive morphologies with the final morphologies at the bottom.

A thermodynamics model for morphology prediction of aluminum nano crystals fabricated by the inert gas condensation method

NASA Astrophysics Data System (ADS)

Wen, Yu; Xia, Dehong

2018-03-01

The purpose of this study is to provide scientific guidance for the morphological control of nanoparticle synthesis using the gas phase method. A universal thermodynamics model is developed to predict the morphology of nanoparticles fabricated using the inert gas condensation method. By using this model, the morphologies of aluminum nanocrystals are predicted under various preparation conditions. There are two types of energy that jointly determine the formation of nanoparticle morphology—Gibbs free energy for nanoparticles and energy variation during the process. The results show that energy variation dominates morphology formation when the cooling rate is less than 2 × 1011 K s-1 in the aluminum nanocrystal production process. At the beginning of the nanoparticle growth, the most stable morphology is predicted to be spherical, but the energetically preferred morphology becomes cubic as the particle grows. The turning point in the particle size at which spherical morphology is no longer the most stable morphology is exhibited as a function of pressure in a condensation chamber for different cooling rates. In this paper, we focus on the need for morphology prediction based on preparation conditions. It is concluded that nanoparticles with various morphologies could be obtained by adjusting the cooling rate and pressure in the condensation chamber.

Influence of airway wall compliance on epithelial cell injury and adhesion during interfacial flows

PubMed Central

Higuita-Castro, Natalia; Mihai, Cosmin; Hansford, Derek J.

2014-01-01

Interfacial flows during cyclic airway reopening are an important source of ventilator-induced lung injury. However, it is not known how changes in airway wall compliance influence cell injury during airway reopening. We used an in vitro model of airway reopening in a compliant microchannel to investigate how airway wall stiffness influences epithelial cell injury. Epithelial cells were grown on gel substrates with different rigidities, and cellular responses to substrate stiffness were evaluated in terms of metabolic activity, mechanics, morphology, and adhesion. Repeated microbubble propagations were used to simulate cyclic airway reopening, and cell injury and detachment were quantified via live/dead staining. Although cells cultured on softer gels exhibited a reduced elastic modulus, these cells experienced less plasma membrane rupture/necrosis. Cells on rigid gels exhibited a minor, but statistically significant, increase in the power law exponent and also exhibited a significantly larger height-to-length aspect ratio. Previous studies indicate that this change in morphology amplifies interfacial stresses and, therefore, correlates with the increased necrosis observed during airway reopening. Although cells cultured on stiff substrates exhibited more plasma membrane rupture, these cells experienced significantly less detachment and monolayer disruption during airway reopening. Western blotting and immunofluorescence indicate that this protection from detachment and monolayer disruption correlates with increased focal adhesion kinase and phosphorylated paxillin expression. Therefore, changes in cell morphology and focal adhesion structure may govern injury responses during compliant airway reopening. In addition, these results indicate that changes in airway compliance, as occurs during fibrosis or emphysema, may significantly influence cell injury during mechanical ventilation. PMID:25213636

Facile synthesis of hierarchical mesoporous weirds-like morphological MnO2 thin films on carbon cloth for high performance supercapacitor application.

PubMed

Shinde, Pragati A; Lokhande, Vaibhav C; Ji, Taeksoo; Lokhande, Chandrakant D

2017-07-15

The mesoporous nanostructured metal oxides have a lot of capabilities to upsurge the energy storing capacity of the supercapacitor. In present work, different nanostructured morphologies of MnO 2 have been successfully fabricated on flexible carbon cloth by simple but capable hydrothermal method at different deposition temperatures. The deposition temperature has strong influence on reaction kinetics, which subsequently alters the morphology and electrochemical performance. Among different nanostructured MnO 2 thin films, the mesoporous weirds composed thin film obtained at temperature of 453K exhibits excellent physical and electrochemical features for supercapacitor application. The weirds composed MnO 2 thin film exhibits specific surface area of 109m 2 g -1 , high specific capacitance of 595Fg -1 with areal capacitance of 4.16Fcm -2 at a scan rate of 5mVs -1 and high specific energy of 56.32Whkg -1 . In addition to this, MnO 2 weirds attain capacity retention of 87 % over 2000 CV cycles, representing better cycling stability. The enhanced electrochemical performance could be ascribed to direct growth of highly porous MnO 2 weirds on carbon cloth which provide more pathways for easy diffusion of electrolyte into the interior of electroactive material. The as-fabricated electrode with improved performance could be ascribed as a potential electrode material for energy storage devices. Copyright © 2017 Elsevier Inc. All rights reserved.

Waking the dead: morphological and molecular characterization of extant †Posoniella tricarinelloides (Thoracosphaeraceae, Dinophyceae).

PubMed

Gu, Haifeng; Kirsch, Monika; Zinssmeister, Carmen; Soehner, Sylvia; Meier, K J Sebastian; Liu, Tingting; Gottschling, Marc

2013-09-01

The Thoracosphaeraceae are dinophytes that produce calcareous shells during their life history, whose optical crystallography has been the basis for the division into subfamilies. To evaluate the validity of the classification (mainly applied by palaeontologists), living material of phylogenetic key species is necessary albeit frequently difficult to access for contemporary morphological and molecular analyses. We isolated and established five living strains of the rare fossil-taxon †Posoniella tricarinelloides from different sediment samples collected in the South China Sea, Yellow Sea and in the Mediterranean Sea (west coast off Italy). Here, we provide detailed descriptions of its morphology and conducted phylogenetic analyses based on hundreds of accessions and thousands of informative sites on concatenated rRNA datasets. Within the monophyletic Peridiniales, †P. tricarinelloides was reliably nested in the Thoracosphaeraceae and exhibited two distinct morphological types of coccoid cells. The two morphologies of coccoid cells would have been assigned to different taxa at the subfamily level if found separately in fossil samples. Our results thus challenge previous classification concepts within the dinophytes and underline the importance of comparative morphological and molecular studies to better understand the complex biology of unicellular organisms such as †P. tricarinelloides. Copyright © 2013 Elsevier GmbH. All rights reserved.

Morphological analysis of the pancreas and liver in diabetic KK-A(y) mice treated with zinc and oxovanadium complexes.

PubMed

Moroki, Takayasu; Yoshikawa, Yutaka; Yoshizawa, Katsuhiko; Tsubura, Airo; Yasui, Hiroyuki

2014-09-01

The relationship between biometals, such as zinc (Zn(2+)), vanadium, copper, cobalt, and magnesium ions, and diabetes therapy has been recognized for several years. In particular, the antidiabetic activities of Zn(2+) and oxovanadium (VO(2+)) complexes have been measured using biochemical approaches. In the present study, diabetic KK-A(y) mice were treated with bis(1-oxy-2-pyridine-thiolato)Zn(2+) (Zn(opt)2) and bis(1-oxy-2-pyridine-thiolato)VO(2+) (VO(opt)2) for 4 weeks, and the antidiabetic activities of these metal complexes were evaluated using biochemical and morphological methods. Additionally, zinc gluconate (Zn(glc)2) and bis(ethylmaltolato)VO(2+) (VO(emal)2) were used as reference compounds. Pancreatic islet cells were smaller, and there was a tendency towards a lower islet cell area ratio in Zn(opt)2-treated mice compared with nontreated KK-A(y) mice. Furthermore, plasma insulin concentrations were significantly reduced to 27.2% of insulin concentrations in nontreated KK-A(y) mice. These results suggest that Zn(opt)2 administration provides morphological and biochemical improvements in hyperinsulinaemia. In contrast, in mice that received Zn(glc)2 and VO(2+) complexes, the islet cell size and islet cell area ratio did not differ from those in nontreated controls. Zn(opt)2- and VO(opt)2-treated mice exhibited significantly lower fat deposition and fat deposition area ratio in the liver (63.6% and 65.8% of nontreated KK-A(y) mice, respectively) compared to those observed in nontreated KK-A(y) mice. The differences in morphological improvements of the pancreas and liver owing to Zn(opt)2 or VO(opt)2 treatment may be explained by differences in the sites of actions of Zn(2+) and VO(2+) complexes in different organs in KK-A(y) mice. In conclusion, Zn(opt)2 exhibited superior antidiabetic effects over those of VO(opt)2, and this was owing to greater amelioration of the morphological parameters of the liver and pancreas.

Functional Morphology of Eunicidan (Polychaeta) Jaws

NASA Astrophysics Data System (ADS)

Clemo, W. C.; Dorgan, K. M.

2016-02-01

Polychaetes exhibit diverse feeding strategies and diets, with some species possessing hardened teeth or jaws of varying complexity. Species in the order Eunicida have complex, rigidly articulated jaws consisting of multiple pairs of maxillae and a pair of mandibles. While all Eunicida possess this general jaw structure, a number of characteristics of the jaw parts vary considerably among families. These differences, described for fossilized and extant species' jaws, were used to infer evolutionary relationships, but current phylogeny shows that jaw structures that are similar among several families are convergent. Little has been done, however, to relate jaw functional morphology and feeding behavior to diet. To explore these relationships, we compared the jaw kinematics of two taxa with similar but evolutionarily convergent jaw structures: Diopatra (Onuphidae) and Lumbrineris (Lumbrineridae). Diopatra species are tube-dwelling and predominantly herbivorous, whereas Lumbrineris species are burrowing carnivores. Jaw kinematics were observed and analyzed by filming individuals biting or feeding and tracking tooth movements in videos. Differences in jaw structure and kinematics between Diopatra and Lumbrineris can be interpreted to be consistent with their differences in diet. Relating jaw morphology to diet would provide insight into early annelid communities by linking fossil teeth (scolecodonts) to the ecological roles of extant species with similar morphologies.

Form follows function: ultrastructure of different morphotypes of Physarum polycephalum

NASA Astrophysics Data System (ADS)

Oettmeier, Christina; Lee, Jonghyun; Döbereiner, Hans-Günther

2018-04-01

The multinucleate, unicellular slime mold Physarum polycephalum is a highly motile and morphologically diverse giant amoeba. Despite being brainless and lacking neurons, it exhibits ‘smart’ behavior. There is considerable interest in describing such traits and to investigate the underlying mechanochemical patterns which may hint at universal principles of behavior and decision-making. Furthermore, the slime mold’s mechanism of locomotion is unique. It resembles amoeboid movement, but differs from the locomotion of other amoebae in many ways, e.g. in their much larger size and lack of lobopodia. These two aspects, behavior and locomotion, are linked by the cytoskeleton and the overall morphology of P. polycephalum. In this paper, we present a structural analysis of different growth forms (micro-, meso- and macroplasmodia) by transmission electron microscopy (TEM), scanning electron microscopy (SEM), light microscopy, and fluorescence microscopy of F-actin. With these detailed investigations of cellular ultrastructure and morphology, we provide the basis for the analysis of, e.g. viscoelastic and rheological measurements. Our data also provide structural details for the many models that have been constructed for the understanding of locomotion. We conclude that morphological information is vital for the assessment and measurement of material properties.

Correlated evolution of personality, morphology and performance

PubMed Central

Kern, Elizabeth M. A.; Robinson, Detric; Gass, Erika; Godwin, John; Langerhans, R. Brian

2018-01-01

Evolutionary change in one trait can elicit evolutionary changes in other traits due to genetic correlations. This constrains the independent evolution of traits and can lead to unpredicted ecological and evolutionary outcomes. Animals might frequently exhibit genetic associations among behavioural and morphological-physiological traits, because the physiological mechanisms behind animal personality can have broad multitrait effects and because many selective agents influence the evolution of multiple types of traits. However, we currently know little about genetic correlations between animal personalities and nonbehavioural traits. We tested for associations between personality, morphology and locomotor performance by comparing zebrafish (Danio rerio) collected from the wild and then selectively bred for either a proactive or reactive stress coping style (‘bold’ or ‘shy’ phenotypes). Based on adaptive hypotheses of correlational selection in the wild, we predicted that artificial selection for boldness would produce correlated evolutionary responses of larger caudal regions and higher fast-start escape performance (and the opposite for shyness). After four to seven generations, morphology and locomotor performance differed between personality lines: bold zebrafish exhibited a larger caudal region and higher fast-start performance than fish in the shy line, matching predictions. Individual-level phenotypic correlations suggested that pleiotropy or physical gene linkage likely explained the correlated response of locomotor performance, while the correlated response of body shape may have reflected linkage disequilibrium, which is breaking down each generation in the laboratory. Our results indicate that evolution of personality can result in concomitant changes in morphology and whole-organism performance, and vice versa. PMID:29398712

Spectral evidence for a carbonaceous chondrite surface composition on Deimos

NASA Technical Reports Server (NTRS)

Pang, K. D.; Rhoads, J. W.; Lane, A. L.; Ajello, J. M.

1980-01-01

The surface compositions of Phobos and Deimos as determined by their UV-visible reflectance are compared in order to evaluate the hypothesis that the different surface morphologies of the two satellites are due to different mechanical properties. The UV-visible reflectance spectrum of Deimos is compiled from Mariner 9 UV spectrometry and Canopus star tracker photometry and ground-based colorimetry and polarimetry; the geometric albedo of Deimos is determined from Mariner 9 Canopus star tracker data. The reflectance spectra of Deimos and Phobos are found to be similar in a first approximation, exhibiting low, flat reflectivities in the visible and dropping off sharply in the UV, compatible with a probable carbonaceous chondrite nature for Deimos as well as Phobos and suggesting that their different surface morphologies are most likely due to different orbital histories.

Characteristics of Saccharomyces cerevisiae yeasts exhibiting rough colonies and pseudohyphal morphology with respect to alcoholic fermentation.

PubMed

Reis, Vanda Renata; Bassi, Ana Paula Guarnieri; da Silva, Jessica Carolina Gomes; Ceccato-Antonini, Sandra Regina

2013-12-01

Among the native yeasts found in alcoholic fermentation, rough colonies associated with pseudohyphal morphology belonging to the species Saccharomyces cerevisiae are very common and undesirable during the process. The aim of this work was to perform morphological and physiological characterisations of S. cerevisiae strains that exhibited rough and smooth colonies in an attempt to identify alternatives that could contribute to the management of rough colony yeasts in alcoholic fermentation. Characterisation tests for invasiveness in Agar medium, killer activity, flocculation and fermentative capacity were performed on 22 strains (11 rough and 11 smooth colonies). The effects of acid treatment at different pH values on the growth of two strains ("52"--rough and "PE-02"--smooth) as well as batch fermentation tests with cell recycling and acid treatment of the cells were also evaluated. Invasiveness in YPD Agar medium occurred at low frequency; ten of eleven rough yeasts exhibited flocculation; none of the strains showed killer activity; and the rough strains presented lower and slower fermentative capacities compared to the smooth strains in a 48-h cycle in a batch system with sugar cane juice. The growth of the rough strain was severely affected by the acid treatment at pH values of 1.0 and 1.5; however, the growth of the smooth strain was not affected. The fermentative efficiency in mixed fermentation (smooth and rough strains in the same cell mass proportion) did not differ from the efficiency obtained with the smooth strain alone, most likely because the acid treatment was conducted at pH 1.5 in a batch cell-recycle test. A fermentative efficiency as low as 60% was observed with the rough colony alone.

Characteristics of Saccharomyces cerevisiae yeasts exhibiting rough colonies and pseudohyphal morphology with respect to alcoholic fermentation

PubMed Central

Reis, Vanda Renata; Bassi, Ana Paula Guarnieri; da Silva, Jessica Carolina Gomes; Ceccato-Antonini, Sandra Regina

2013-01-01

Among the native yeasts found in alcoholic fermentation, rough colonies associated with pseudohyphal morphology belonging to the species Saccharomyces cerevisiae are very common and undesirable during the process. The aim of this work was to perform morphological and physiological characterisations of S. cerevisiae strains that exhibited rough and smooth colonies in an attempt to identify alternatives that could contribute to the management of rough colony yeasts in alcoholic fermentation. Characterisation tests for invasiveness in Agar medium, killer activity, flocculation and fermentative capacity were performed on 22 strains (11 rough and 11 smooth colonies). The effects of acid treatment at different pH values on the growth of two strains (“52” - rough and “PE-02” - smooth) as well as batch fermentation tests with cell recycling and acid treatment of the cells were also evaluated. Invasiveness in YPD Agar medium occurred at low frequency; ten of eleven rough yeasts exhibited flocculation; none of the strains showed killer activity; and the rough strains presented lower and slower fermentative capacities compared to the smooth strains in a 48-h cycle in a batch system with sugar cane juice. The growth of the rough strain was severely affected by the acid treatment at pH values of 1.0 and 1.5; however, the growth of the smooth strain was not affected. The fermentative efficiency in mixed fermentation (smooth and rough strains in the same cell mass proportion) did not differ from the efficiency obtained with the smooth strain alone, most likely because the acid treatment was conducted at pH 1.5 in a batch cell-recycle test. A fermentative efficiency as low as 60% was observed with the rough colony alone. PMID:24688501

The Relationship between Cranial Structure, Biomechanical Performance and Ecological Diversity in Varanoid Lizards

PubMed Central

McCurry, Matthew R.; Mahony, Michael; Clausen, Phillip D.; Quayle, Michelle R.; Walmsley, Christopher W.; Jessop, Tim S.; Wroe, Stephen; Richards, Heather; McHenry, Colin R.

2015-01-01

Skull structure is intimately associated with feeding ability in vertebrates, both in terms of specific performance measures and general ecological characteristics. This study quantitatively assessed variation in the shape of the cranium and mandible in varanoid lizards, and its relationship to structural performance (von Mises strain) and interspecific differences in feeding ecology. Geometric morphometric and linear morphometric analyses were used to evaluate morphological differences, and finite element analysis was used to quantify variation in structural performance (strain during simulated biting, shaking and pulling). This data was then integrated with ecological classes compiled from relevant scientific literature on each species in order to establish structure-function relationships. Finite element modelling results showed that variation in cranial morphology resulted in large differences in the magnitudes and locations of strain in biting, shaking and pulling load cases. Gracile species such as Varanus salvadorii displayed high strain levels during shaking, especially in the areas between the orbits. All models exhibit less strain during pull back loading compared to shake loading, even though a larger force was applied (pull =30N, shake = 20N). Relationships were identified between the morphology, performance, and ecology. Species that did not feed on hard prey clustered in the gracile region of cranial morphospace and exhibited significantly higher levels of strain during biting (P = 0.0106). Species that fed on large prey clustered in the elongate area of mandible morphospace. This relationship differs from those that have been identified in other taxonomic groups such as crocodiles and mammals. This difference may be due to a combination of the open ‘space-frame’ structure of the varanoid lizard skull, and the ‘pull back’ behaviour that some species use for processing large prey. PMID:26106889

Nanomechanical properties of distinct fibrillar polymorphs of the protein α-synuclein

PubMed Central

Makky, Ali; Bousset, Luc; Polesel-Maris, Jérôme; Melki, Ronald

2016-01-01

Alpha-synuclein (α-Syn) is a small presynaptic protein of 140 amino acids. Its pathologic intracellular aggregation within the central nervous system yields protein fibrillar inclusions named Lewy bodies that are the hallmarks of Parkinson’s disease (PD). In solution, pure α-Syn adopts an intrinsically disordered structure and assembles into fibrils that exhibit considerable morphological heterogeneity depending on their assembly conditions. We recently established tightly controlled experimental conditions allowing the assembly of α-Syn into highly homogeneous and pure polymorphs. The latter exhibited differences in their shape, their structure but also in their functional properties. We have conducted an AFM study at high resolution and performed a statistical analysis of fibrillar α-Syn shape and thermal fluctuations to calculate the persistence length to further assess the nanomechanical properties of α-Syn polymorphs. Herein, we demonstrated quantitatively that distinct polymorphs made of the same protein (wild-type α-Syn) show significant differences in their morphology (height, width and periodicity) and physical properties (persistence length, bending rigidity and axial Young’s modulus). PMID:27901068

Optoelectronic performance comparison of new thiophene linked benzimidazole conjugates with diverse substitution patterns

NASA Astrophysics Data System (ADS)

Saltan, Gözde Murat; Dinçalp, Haluk; Kırmacı, Eser; Kıran, Merve; Zafer, Ceylan

2018-01-01

In an approach to develop efficient organic optoelectronic devices to be used in light-driven systems, a series of three thiophene linked benzimidazole conjugates were synthesized and characterized. The combination of two thiophene rings to a benzimidazole core decorated with different functional groups (such as sbnd OCH3, sbnd N(CH3)2, sbnd CF3) resulted in donor-acceptor type molecular scaffold. The effect of the electronic behavior of the substituents on the optical, electrochemical, morphological and electron/hole transporting properties of the dyes were systematically investigated. DTBI2 dye exhibited distinct absorption properties among the other studied dyes because N,N-dimethylamino group initiated intramolecular charge transfer (ICT) process in the studied solvents. In solid state, the dyes exhibit peaks extending up to 600 nm. Depending on the solvent polarities, dyes show significant wavelength changes on their fluorescence emission spectra in the excited states. Morphological parameters of the thin films spin-coated from CHCl3 solution were investigated by using AFM instrument; furthermore photovoltaic responses are reported, even though photovoltaic performances of the fabricated solar cells with different configurations are quite low.

The Cervical Osteology of Okapia johnstoni and Giraffa camelopardalis.

PubMed

Danowitz, Melinda; Solounias, Nikos

2015-01-01

Giraffidae is the only family of ruminants that is represented by two extant species; Okapia johnstoni and Giraffa camelopardalis. Of these taxa, O. johnstoni represents a typical short-necked ungulate, and G. camelopardalis exemplifies the most extreme cervical elongation seen in any ruminant. We utilize these two species to provide a comprehensive anatomic description of the cervical vertebrae. In addition, we compare the serial morphologic characteristics of the okapi and giraffe cervical vertebrae, and report on several osteologic differences seen between the two taxa. The giraffe neck appears to exhibit homogenization of C3-C7; the position of the dorsal tubercle, thickness of the cranial articular process, shape of the ventral vertebral body, and orientation of the ventral tubercle are constant throughout these vertebrae, whereas these features are serially variable in the okapi. We also report on several specializations of the giraffe C7, which we believe relates to an atypical cervico-thoracic junction, corresponding to the substantial neck lengthening. The morphologic differences exhibited between the okapi and giraffe cervical vertebrae have implications on the function of the necks relating to both fighting and feeding.

The Cervical Osteology of Okapia johnstoni and Giraffa camelopardalis

PubMed Central

2015-01-01

Giraffidae is the only family of ruminants that is represented by two extant species; Okapia johnstoni and Giraffa camelopardalis. Of these taxa, O. johnstoni represents a typical short-necked ungulate, and G. camelopardalis exemplifies the most extreme cervical elongation seen in any ruminant. We utilize these two species to provide a comprehensive anatomic description of the cervical vertebrae. In addition, we compare the serial morphologic characteristics of the okapi and giraffe cervical vertebrae, and report on several osteologic differences seen between the two taxa. The giraffe neck appears to exhibit homogenization of C3-C7; the position of the dorsal tubercle, thickness of the cranial articular process, shape of the ventral vertebral body, and orientation of the ventral tubercle are constant throughout these vertebrae, whereas these features are serially variable in the okapi. We also report on several specializations of the giraffe C7, which we believe relates to an atypical cervico-thoracic junction, corresponding to the substantial neck lengthening. The morphologic differences exhibited between the okapi and giraffe cervical vertebrae have implications on the function of the necks relating to both fighting and feeding. PMID:26302156

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. © 2014 European Society For Evolutionary Biology. Journal of Evolutionary Biology © 2014 European Society For Evolutionary Biology.

Effects of organic solvents on drug incorporation into polymeric carriers and morphological analyses of drug-incorporated polymeric micelles.

PubMed

Harada, Yoshiko; Yamamoto, Tatsuhiro; Sakai, Masaru; Saiki, Toshiharu; Kawano, Kumi; Maitani, Yoshie; Yokoyama, Masayuki

2011-02-14

We incorporated an anticancer agent, camptothecin (CPT), into polymeric micelle carriers by using two different solvents (TFE and chloroform) in the solvent-evaporation drug incorporation process. We observed significant differences in the drug-incorporation behaviors, in the morphologies of the incorporated drug and the polymeric micelles, and in the pharmacokinetic behaviors between the two solvents' cases. In particular, the CPT-incorporated polymeric micelles prepared with TFE as the incorporation solvent exhibited more stable circulation in blood than those prepared with chloroform. This contrast indicates a novel technological perspective regarding the drug incorporation into polymeric micelle carriers. Morphological analyses of the inner core have revealed the presence of the directed alignment of the CPT molecules and CPT crystals in the micelle inner core. This is the first report of the morphologies of the drug incorporated into the polymeric micelle inner cores. We believe these analyses are very important for further pharmaceutical developments of polymeric micelle drug-carrier systems. Copyright © 2010 Elsevier B.V. All rights reserved.

Contrasting evolutionary patterns in two reef-corals and their possible relationship to life history traits

DOE Office of Scientific and Technical Information (OSTI.GOV)

Foster, A.B.

1985-01-01

Multivariate statistical analyses have been used to redefine species within two genera of reef-corals (Porites and Montastraea) and to trace their evolutionary patterns through a continuous sequence from late Miocene to early Pliocene time. The material studied consists of populations sampled at regular intervals through four stratigraphic sections in the northern Dominican Republic. The results show that species in the first genus (Porites) have relatively short durations, morphologic stability, and narrow spatial distributions. Their overall evolutionary history is characterized by short periods of radiation and widespread extinction, separated by longer periods of stasis. In contrast, species in the second genusmore » (Montastraea) exhibit various different durations and distributions and directional morphologic trends. These differences in patterns may be related to the dissimilar life histories of the two genera. Patterns in the first genus appear more common in organisms having high larval recruitment, high mortality, high genetic variation, and less morphologic distance between species. Patterns in the second genus occur more frequently in slower growing, phenotypically plastic organisms experiencing less recruitment and mortality and showing more morphologic distance between species.« less

The role of support morphology on the performance of Cu/ZnO-catalyst for hydrogenation of CO{sub 2} to methanol

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tasfy, Sara Faiz Hanna, E-mail: miss25208@gmail.com; Zabidi, Noor Asmawati Mohd, E-mail: noorasmawati-mzabidi@petronas.com.my; Shaharun, Maizatul Shima, E-mail: maizats@petronas.com.my

The effects of SBA-15 support morphology on the activity of Cu/ZnO catalyst in the hydrogenation of CO{sub 2} to methanol was investigated. In the hydrogenation of CO{sub 2} to methanol at 210°C, 2.25 MPa, H{sub 2}/CO{sub 2} ratio of three remarkable difference was obtained using Cu/ZnO catalyst supported on SBA-15 with different morphology. The catalysts were characterized using N{sub 2}-adsorption, field emission scanning microscopy (FESEM/EDX), transmission electron microscopy (HRTEM), and temperature-programmed reduction (TPR). Characterization of the catalyst showed that support morphology, surface area, metals dispersion, and reducibility influenced the catalytic performance. On the fiber-shaped SBA-15, copper dispersion was 29 % whereasmore » on the spherical-shaped SBA-15, the dispersion was 20 %. The experimental results showed that the catalyst supported over fiber-shaped SBA-15 exhibit higher CO{sub 2} conversion (13.96 %) and methanol selectivity (91.32 %) compare to catalyst supported over spherical-shaped SBA-15.« less

Determinants and taxonomic consequences of extreme egg shell variability in Ramazzottius subanomalus (Biserov, 1985) (Tardigrada).

PubMed

Stec, Daniel; Morek, Witold; Gąsiorek, Piotr; Kaczmarek, Łukasz; Michalczyk, Łukasz

2016-12-15

Nearly a half of known eutardigrade species lay ornamented eggs. The ornamentation is thought to provide attachment of the egg to the substrate and protection for the developing embryo, but from the taxonomic point of view chorion morphology may also provide key characters for species differentiation and identification, especially between closely related taxa. Nonetheless, despite the evolutionary and taxonomic importance of the egg shell, the determinants of its morphology are very poorly, if at all, understood. Here, we combine morphological, molecular and experimental approaches in an attempt to separate the genetic and environmental factors that shape egg chorion morphology in Ramazzottius subanomalus (Biserov, 1985). Our integrative study, based on a population of R. subanomalus isolated from a single moss sample, revealed (1) remarkable variation in egg shell morphology, but (2) relatively little variation in animal morphometric traits, and (3) genetic differentiation, expressed as two ITS-2 haplotypes, but no parallel polymorphism in COI. Although animals did not differ morphometrically between the haplotypes, eggs laid by haplotype 1 and 2 females exhibited highly statistically significant differences in all measured traits. The study demonstrates, for the first time, a correlation between phenotypic and genetic variability within a tardigrade species. The revealed congruence between genetic and morphological traits might be viewed as an example of incipient speciation that illustrates early evolutionary steps leading to species complexes that differ primarily in terms of egg shell morphology. Moreover, our data confirm the value of the ITS-2 fragment in distinguishing very closely related tardigrade lineages.

Controllable synthesis, morphology evolution and electrochemical properties of LiFePO4 cathode materials for Li-ion batteries.

PubMed

Song, Jianjun; Wang, Lin; Shao, Guangjie; Shi, Meiwu; Ma, Zhipeng; Wang, Guiling; Song, Wei; Liu, Shuang; Wang, Caixia

2014-05-07

Monodispersed LiFePO4 nanocrystals with diverse morphologies were successfully synthesized via a mild and controllable solvothermal approach with a mixture of ethylene glycol and oleic acid as the solvent. Morphology evolution of LiFePO4 nanoparticles from nanoplates to nanorods can be simply realized by varying the volume ratio of oleic acid to ethylene glycol. Moreover, the mechanism of competitive adsorption between ethylene glycol and oleic acid was proposed for the formation of different morphologies. Electrochemical measurements show that the LiFePO4/C nanorods have an initial discharge capacity of 155 mA h g(-1) at 0.5 C with a capacity retention of 80% at a high rate of 5 C, which confirms that LiFePO4/C nanorods exhibit excellent rate capability and cycling stability.

Morphology control of layer-structured gallium selenide nanowires.

PubMed

Peng, Hailin; Meister, Stefan; Chan, Candace K; Zhang, Xiao Feng; Cui, Yi

2007-01-01

Layer-structured group III chalcogenides have highly anisotropic properties and are attractive materials for stable photocathodes and battery electrodes. We report the controlled synthesis and characterization of layer-structured GaSe nanowires via a catalyst-assisted vapor-liquid-solid (VLS) growth mechanism during GaSe powder evaporation. GaSe nanowires consist of Se-Ga-Ga-Se layers stacked together via van der Waals interactions to form belt-shaped nanowires with a growth direction along the [11-20], width along the [1-100], and height along the [0001] direction. Nanobelts exhibit a variety of morphologies including straight, zigzag, and saw-tooth shapes. These morphologies are realized by controlling the growth temperature and time so that the actual catalysts have a chemical composition of Au, Au-Ga alloy, or Ga. The participation of Ga in the VLS catalyst is important for achieving different morphologies of GaSe. In addition, GaSe nanotubes are also prepared by a slow growth process.

Vapor-phase deposition of regioregular and oriented poly(3-hexylthiophene) structures and novel nanostructured composites of interpenetrating poly(3-hexylthiophene) and polyaniline exhibiting full-color wavelength (400-1000 nm) photoluminescence

NASA Astrophysics Data System (ADS)

Biswas, A.; Bayer, I. S.; Karulkar, P. C.; Tripathi, A.; Avasthi, D. K.

2007-10-01

A promising solvent-free technique of electron-beam-assisted vapor-phase codeposition method is presented which allows uniform blending of different conjugated and nonconjugated polymers at the nanoscale. The technique allows direct incorporation of regioregular poly(3-hexylthiophene) (P3HT) polymer with different structural orientations into conventional and semiconducting polymers without fractionation or degradation of P3HT while maintaining the nanoscale morphology of deposited organic films. The results of fabricated novel nanostructured organic composites (˜100-200nm) comprising regioregular and oriented P3HT and different conjugated and nonconjugated polymers including selective assembly of P3HT nanonodules into a copolymer template are presented. We show a typical example of blending of P3HT and polyaniline (PANI) that formed a unique nanoscale morphology comprising interpenetrating networks of different shapes and sizes of nanospherulites (˜100nm) of P3HT in PANI. The so fabricated nanocomposites (˜200nm) exhibited remarkable broadband photoluminescence features covering the entire blue, green, and red wavelength regions between 400 and 1000nm. Such organic nanocomposites might be useful for flexible full-color screen flat panel displays and organic white-light solid-state lighting applications.

Photoelectrochemical performance of W-doped BiVO4 thin-films deposited by spray pyrolysis

NASA Astrophysics Data System (ADS)

Holland, Stephen K.; Dutter, Melissa R.; Lawrence, David J.; Reisner, Barbara A.; DeVore, Thomas C.

2013-09-01

The effect of tungsten doping and hydrogen annealing treatments on the photoelectrochemical (PEC) performance of bismuth vanadate (BiVO4) photoanodes for solar water splitting was studied. Thin films of BiVO4 were deposited on ITO-coated glass slides by ultrasonic spray pyrolysis of an aqueous solution containing bismuth nitrate and vanadium oxysulfate. Tungsten doping was achieved by adding either silicotungstic acid (STA) or ammonium metatungstate (AMT) in the aqueous precursor. The 1.7 μm - 2.2 μm thick films exhibited a highly porous microstructure. Undoped films that were reduced at 375 ºC in 3% H2 exhibited the largest photocurrent densities under 0.1 W cm-2 AM1.5 illumination. This performance enhancement was believed to be due to the formation of oxygen vacancies, which are shallow electron donors, in the films. Films doped with 1% or 5% tungsten from either STA or AMT exhibited reduced photoelectrochemical performance and greater sample-to-sample performance variations. Powder X-ray diffraction data of the undoped films indicated that they were comprised primarily of the monoclinic scheelite phase while unidentified phases were also present. Scanning electron microscopy showed slightly different morphology characteristics for the Wdoped films. It is surmised that the addition of W in the deposition process promoted the morphology differences and the formation of different phases, thus reducing the PEC performance of the photoanode samples. Significant PEC performance variability was also observed among films deposited using the described process.

Coercivity and Exchange Bias Study of Polycrystalline Hollow Nanoparticles

NASA Astrophysics Data System (ADS)

Bah, Mohamed Alpha

Magnetic nanoparticles (NPs) have the potential to be useful in a variety of applications such as biomedical instruments, catalysis, sensing, recording information, etc. These nanoparticles exhibit remarkably different properties compared to their bulk counter parts. Synthesis of magnetic NPs with the right morphology, phase, size and surface functionality, as well as their usage for specific applications are challenging in terms of efficiency and safety. Morphology wise, there have been numerous reports on magnetic nanoparticles where morphologies such as core/shell, hollow, solid, etc., have been explored. It has been shown that morphology affects the magnetic response. Achieving the right crystal structure with required morphology and the magnetic behavior of the nanoparticle phases determines the magnetic response of the structure. For example, in the case of core/shell NPs various ferromagnetic (FM), ferrimagnetic (FiM), and antiferromagnetic (AFM) core and shell combinations have been reported. In these cases, interesting and strikingly different features, such as unusually high spin glass transition temperature, large exchange bias, finite size effects, magnetic proximity effects, unusual trend of blocking temperature as function of average crystal size, etc., have been reported. More specifically, the morphology of core/shell nanoparticles provides added degrees of freedom compared to conventional solid magnetic nanoparticles, including variations in the size, phase and material of the core and shell of the particle, etc. which helps enhance their magnetic properties. Similar to traditional core/shell nanoparticles, inverted core/shell having a FiM or FM order above the Curie temperature (TC) of the shell has been reported where the Neel temperature (TN) is comparable with the bulk value and there is nonmonotonic dependence of the coercive field (HC) and exchange bias (HEB) on the core diameter. In addition to the core/shell morphology, nanoparticles with hollow morphology are also of interest to the scientific community. For such cases, surface spin glass transition enhancements have been reported due to the presence of the additional inner surface. CoFe2O4, NiFe 2O4 and gamma-Fe2O3 hollow nanoparticles exhibit strikingly contrasting magnetic behavior compared to bulk and conventional solid particles; similar behavior was also observed in core/shell nanoparticles. Structurally, hollow polycrystalline nanoparticles are composed of multiple crystallographic domains. This random orientation of the crystallographic domains also causes randomization of the local anisotropy axes. Hence the overall effect of this morphology on the magnetic properties is exhibited through the high coercivity, relatively high temperature magnetic irreversibility, lack of magnetic saturation, high blocking temperature, etc. Over the years, extensive work on core/shell nanoparticles have been carried out to understand their exchange bias phenomenon and the effect on coercivity. Recently, focus has been given to hollow polycrystalline nanoparticles for the reason mentioned above. This thesis investigates the root cause for the above-mentioned effects on the coercivity and exchange bias. Since hollow nanoparticles with polycrystalline structure have shown to exhibit different and improved magnetic behavior compared to bulk and other conventional solid particles, they will be the focus of our investigation. First, extensive field and temperature dependent magnetic study on polycrystalline hollow nickel ferrite (NiFe2O4) have revealed the effect of the presence of inner surface in a single oxide nanoparticle. Second, the effect of having multiple oxides with different magnetic properties (i.e. FM and AFM) in a single nanoparticle, while maintaining a hollow morphology was investigated by studying polycrystalline hollow gamma-Mn2O3 and MnO nanoparticles. Studies on various conventional solid manganese oxide nanoparticles have already been reported. Therefore, focus was only made on the fabrication and magnetic study of hollow polycrystalline manganese oxide, with a comparison of the results to those from solid nanoparticles already available in literature. A conclusion was drawn to the importance of the coupling of different magnetic phases (i.e. FM and AFM, FiM and AFM, or SG and AFM), in contrast to just having one single oxide in the hollow nanoparticles. Finally, the importance of this coupling as compared to the increase of surface-to-volume ratio was evaluated in CoO/Co3O4/CoFe2O4 polycrystalline hollow nanoparticles by varying the AFM phase (CoO/Co 3O4) in the nanoparticles and observing how the magnetic properties varied. This system helped address the effect of the coupling between different magnetic phases, super-exchange interaction, and proximity effect.

Morphological evolution of various fungal species in the presence and absence of aluminum oxide microparticles: Comparative and quantitative insights into microparticle-enhanced cultivation (MPEC).

PubMed

Kowalska, Anna; Boruta, Tomasz; Bizukojć, Marcin

2018-03-05

The application of microparticle-enhanced cultivation (MPEC) is an attractive method to control mycelial morphology, and thus enhance the production of metabolites and enzymes in the submerged cultivations of filamentous fungi. Unfortunately, most literature data deals with the spore-agglomerating species like aspergilli. Therefore, the detailed quantitative study of the morphological evolution of four different fungal species (Aspergillus terreus, Penicillium rubens, Chaetomium globosum, and Mucor racemosus) based on the digital analysis of microscopic images was presented in this paper. In accordance with the current knowledge, these species exhibit different mechanisms of agglomerates formation. The standard submerged shake flask cultivations (as a reference) and MPEC involving 10 μm aluminum oxide microparticles (6 g·L -1 ) were performed. The morphological parameters, including mean projected area, elongation, roughness, and morphology number were determined for the mycelial objects within the first 24 hr of growth. It occurred that heretofore observed and widely discussed effect of microparticles on fungi, namely the decrease in pellet size, was not observed for the species whose pellet formation mechanism is different from spore agglomeration. In the MPEC, C. globosum developed core-shell pellets, and M. racemosus, a nonagglomerative species, formed the relatively larger, compared to standard cultures, pellets with distinct cores. © 2018 The Authors. MicrobiologyOpen published by John Wiley & Sons Ltd.

Morphological analysis of Trichomycterus areolatus Valenciennes, 1846 from southern Chilean rivers using a truss-based system (Siluriformes, Trichomycteridae)

PubMed Central

Colihueque, Nelson; Corrales, Olga; Yáñez, Miguel

2017-01-01

Abstract Trichomycterus areolatus Valenciennes, 1846 is a small endemic catfish inhabiting the Andean river basins of Chile. In this study, the morphological variability of three T. areolatus populations, collected in two river basins from southern Chile, was assessed with multivariate analyses, including principal component analysis (PCA) and discriminant function analysis (DFA). It is hypothesized that populations must segregate morphologically from each other based on the river basin that they were sampled from, since each basin presents relatively particular hydrological characteristics. Significant morphological differences among the three populations were found with PCA (ANOSIM test, r = 0.552, p < 0.0001) and DFA (Wilks’s λ = 0.036, p < 0.01). PCA accounted for a total variation of 56.16% by the first two principal components. The first Principal Component (PC1) and PC2 explained 34.72 and 21.44% of the total variation, respectively. The scatter-plot of the first two discriminant functions (DF1 on DF2) also validated the existence of three different populations. In group classification using DFA, 93.3% of the specimens were correctly-classified into their original populations. Of the total of 22 transformed truss measurements, 17 exhibited highly significant (p < 0.01) differences among populations. The data support the existence of T. areolatus morphological variation across different rivers in southern Chile, likely reflecting the geographic isolation underlying population structure of the species. PMID:29134012

Effects of Morphology Constraint on Electrophysiological Properties of Cortical Neurons

NASA Astrophysics Data System (ADS)

Zhu, Geng; Du, Liping; Jin, Lei; Offenhäusser, Andreas

2016-04-01

There is growing interest in engineering nerve cells in vitro to control architecture and connectivity of cultured neuronal networks or to build neuronal networks with predictable computational function. Pattern technologies, such as micro-contact printing, have been developed to design ordered neuronal networks. However, electrophysiological characteristics of the single patterned neuron haven’t been reported. Here, micro-contact printing, using polyolefine polymer (POP) stamps with high resolution, was employed to grow cortical neurons in a designed structure. The results demonstrated that the morphology of patterned neurons was well constrained, and the number of dendrites was decreased to be about 2. Our electrophysiological results showed that alterations of dendritic morphology affected firing patterns of neurons and neural excitability. When stimulated by current, though both patterned and un-patterned neurons presented regular spiking, the dynamics and strength of the response were different. The un-patterned neurons exhibited a monotonically increasing firing frequency in response to injected current, while the patterned neurons first exhibited frequency increase and then a slow decrease. Our findings indicate that the decrease in dendritic complexity of cortical neurons will influence their electrophysiological characteristics and alter their information processing activity, which could be considered when designing neuronal circuitries.

Intraspecific Genetic Admixture and the Morphological Diversification of an Estuarine Fish Population Complex

PubMed Central

Legault, Michel

2015-01-01

The North-east American Rainbow smelt (Osmerus mordax) is composed of two glacial races first identified through the spatial distribution of two distinct mtDNA lineages. Contemporary breeding populations of smelt in the St. Lawrence estuary comprise contrasting mixtures of both lineages, suggesting that the two races came into secondary contact in this estuary. The overall objective of this study was to assess the role of intraspecific genetic admixture in the morphological diversification of the estuarine rainbow smelt population complex. The morphology of mixed-ancestry populations varied as a function of the relative contribution of the two races to estuarine populations, supporting the hypothesis of genetic admixture. Populations comprising both ancestral mtDNA races did not exhibit intermediate morphologies relative to pure populations but rather exhibited many traits that exceeded the parental trait values, consistent with the hypothesis of transgressive segregation. Evidence for genetic admixture at the level of the nuclear gene pool, however, provided only partial support for this hypothesis. Variation at nuclear AFLP markers revealed clear evidence of the two corresponding mtDNA glacial races. The admixture of the two races at the nuclear level is only pronounced in mixed-ancestry populations dominated by one of the mtDNA lineages, the same populations showing the greatest degree of morphological diversification and population structure. In contrast, mixed-ancestry populations dominated by the alternate mtDNA lineage showed little evidence of introgression of the nuclear genome, little morphological diversification and little contemporary population genetic structure. These results only partially support the hypothesis of transgressive segregation and may be the result of the differential effects of natural selection acting on admixed genomes from different sources. PMID:25856193

Patterns of specificity and diversity in species of Paraorygmatobothrium Ruhnke, 1994 (Cestoda: Phyllobothriidae) in Moreton Bay, Queensland, Australia, with the description of four new species.

PubMed

Cutmore, Scott C; Bennett, Michael B; Miller, Terrence L; Cribb, Thomas H

2017-11-01

A survey of tapeworms of galeomorph sharks from Moreton Bay (Queensland, Australia) identified a complex of species of Paraorygmatobothrium Ruhnke, 1994 infecting 11 carcharhiniform and two orectolobiform species. Combined morphological and multi-locus molecular analyses (based on the 28S nuclear ribosomal RNA and partial mitochondrial NADH dehydrogenase subunit 1 genes) revealed the presence of 12 species of Paraorygmatobothrium; four species (Paraorygmatobothrium christopheri n. sp., P. harti n. sp., P. sinclairtaylori n. sp. and P. ullmanni n. sp.) are considered to be new to science and are formally described, four represent known species, and four lack sufficient morphological data to allow definitive identification. In contrast to previous records for the genus, four of the species found in this study exhibited low host specificity [P. orectolobi (Butler, 1987) Ruhnke, 2011, P. sinclairtaylori, P. ullmanni and Paraorygmatobothrium sp. 3], three stenoxenic species were each found in two closely-related sharks (P. orectolobi, P. ullmanni and Paraorygmatobothrium sp. 3) and one euryxenic species was found in five species from two shark families (P. sinclairtaylori). One species was found to exhibit mild morphologically plasticity (P. orectolobi), with size range being associated with different shark species. Conversely, collections of almost morphologically indistinguishable specimens from single shark species were found to represent multiple species of Paraorygmatobothrium. The findings of this study indicate that the description of species of this genus on the basis of morphological data alone is problematic and that the inclusion of multi-locus molecular data is essential for future work on Paraorygmatobothrium. Host specificity, morphology and phylogenetic relatedness of species of Paraorygmatobothrium are explored.

Influence of aggregated morphology on carbon dioxide uptake of polythiophene conjugated organic networks

DOE Office of Scientific and Technical Information (OSTI.GOV)

Qiao, Shanlin; University of Chinese Academy of Sciences, Beijing 100049; Du, Zhengkun

2014-04-01

Two novel thiophene-based conjugated networks CMPs-TTT and CMPs-DTBT were designed and prepared with different steric configuration building blocks by FeCl{sub 3} oxidative coupling polymerization. UV–vis spectra, FE-SEM and TEM images showed CMPs-TTT and CMPs-DTBT having the different aggregated morphologies. After porous analysis and gas adsorption test, the result showed CO{sub 2} uptake capacity of CMPs-DTBT with amorphous aggregation model is 2.88 times and 2.66 times greater than that of CMPs-TTT with large lamellar structure model at 273 K and 298 K (1.0 bar), respectively. As a result, this communication proved that change the topological structure of the polymer can influencemore » the CO{sub 2} adsorption capacity significantly. - Graphical abstract: Two thiophene-based conjugated networks were prepared with different steric configuration building blocks, and they show various CO{sub 2} uptake capacity and sorption isosteric enthalpies, although they have identical chemical constitution. - Highlights: • Topological-directed design and synthesis two conjugated porous polymers. • Two thiophene-based CMPs show different aggregated morphologies. • They exhibit similar porosity structure and different CO{sub 2} uptake capacity.« less

Different characteristics of mesenchymal stem cells isolated from different layers of full term placenta

PubMed Central

Ha, Chul-Won; Kim, Jin A; Heo, Jin-Chul; Han, Woo-Jung; Oh, Soo-Young; Choi, Suk-Joo

2017-01-01

Background The placenta is a very attractive source of mesenchymal stem cells (MSCs) for regenerative medicine due to readily availability, non-invasive acquisition, and avoidance of ethical issues. Isolating MSCs from parts of placenta tissue has obtained growing interest because they are assumed to exhibit different proliferation and differentiation potentials due to complex structures and functions of the placenta. The objective of this study was to isolate MSCs from different parts of the placenta and compare their characteristics. Methods Placenta was divided into amniotic epithelium (AE), amniotic membrane (AM), chorionic membrane (CM), chorionic villi (CV), chorionic trophoblast without villi (CT-V), decidua (DC), and whole placenta (Pla). Cells isolated from each layer were subjected to analyses for their morphology, proliferation ability, surface markers, and multi-lineage differentiation potential. MSCs were isolated from all placental layers and their characteristics were compared. Findings Surface antigen phenotype, morphology, and differentiation characteristics of cells from all layers indicated that they exhibited properties of MSCs. MSCs from different placental layers had different proliferation rates and differentiation potentials. MSCs from CM, CT-V, CV, and DC had better population doubling time and multi-lineage differentiation potentials compared to those from other layers. Conclusions Our results indicate that MSCs with different characteristics can be isolated from all layers of term placenta. These finding suggest that it is necessary to appropriately select MSCs from different placental layers for successful and consistent outcomes in clinical applications. PMID:28225815

Effect of holding pressure on microstructure and fracture behavior of low-pressure die cast A356-T6 alloy

NASA Astrophysics Data System (ADS)

Wu, Xiaoyan; Yun, Ying; Zhang, Huarui; Ma, Zhen; Jia, Lina; Tao, Tongxiang; Zhang, Hu

2017-12-01

The effect of different holding pressures on microstructure, tensile properties and fracture behavior of A356-T6 aluminum alloy was investigated. It was observed that the ultimate strength, yield strength and elongation of A356-T6 aluminum alloy increased with the increasing of holding pressure from 85 kPa to 300 kPa. This was attributed to the finer microstructure and the elimination of porosity defects caused by high holding pressure. The fractographs of specimens obtained under lower holding pressure displayed mixed quasi-cleavage and dimple type morphology with flat dimples and large amount of porosities. However, the fractographs of specimens obtained under high holding pressure of 300 kPa clearly exhibited a dimple morphology with small and deep dimples. The differences in the tensile fracture were attributed to the different shape of eutectic Si particle and different amount of porosity defects.

Sidescan backscatter variations of cold seeps on the Hikurangi Margin (New Zealand): indications for different stages in seep development

NASA Astrophysics Data System (ADS)

Dumke, Ines; Klaucke, Ingo; Berndt, Christian; Bialas, Jörg

2014-06-01

Cold seeps on the Hikurangi Margin off New Zealand exhibit various seabed morphologies producing different intensity patterns in sidescan backscatter images. Acoustic backscatter characteristics of 25 investigated seep sites fall into four distinct types characterised by variations in backscatter intensity, distribution and inferred structural heights. The types reflect different carbonate morphologies including up to 20-m-high structures (type 1), low-relief crusts (type 2), scattered blocks (type 3) and carbonate-free sites (type 4). Each seep corresponds to a single type; intermediates were not observed. This correlates well with published data on seep fauna at each site, with the four types representing three different faunal habitats of successive stages of seep development. Backscatter signatures in sidescan sonar images of cold seeps may therefore serve as a convenient proxy for variations in faunal habitats.

The influence of flight style on the aerodynamic properties of avian wings as fixed lifting surfaces

PubMed Central

Dimitriadis, Grigorios; Nudds, Robert L.

2016-01-01

The diversity of wing morphologies in birds reflects their variety of flight styles and the associated aerodynamic and inertial requirements. Although the aerodynamics underlying wing morphology can be informed by aeronautical research, important differences exist between planes and birds. In particular, birds operate at lower, transitional Reynolds numbers than do most aircraft. To date, few quantitative studies have investigated the aerodynamic performance of avian wings as fixed lifting surfaces and none have focused upon the differences between wings from different flight style groups. Dried wings from 10 bird species representing three distinct flight style groups were mounted on a force/torque sensor within a wind tunnel in order to test the hypothesis that wing morphologies associated with different flight styles exhibit different aerodynamic properties. Morphological differences manifested primarily as differences in drag rather than lift. Maximum lift coefficients did not differ between groups, whereas minimum drag coefficients were lowest in undulating flyers (Corvids). The lift to drag ratios were lower than in conventional aerofoils and data from free-flying soaring species; particularly in high frequency, flapping flyers (Anseriformes), which do not rely heavily on glide performance. The results illustrate important aerodynamic differences between the wings of different flight style groups that cannot be explained solely by simple wing-shape measures. Taken at face value, the results also suggest that wing-shape is linked principally to changes in aerodynamic drag, but, of course, it is aerodynamics during flapping and not gliding that is likely to be the primary driver. PMID:27781155

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yao, Kaisheng; Henan Normal University, School of Chemistry and Environmental Science, Key Laboratory of Green Chemical Media and Reactions, Xin xiang, Henan 453007; Lu, Weiwei

A novel method was proposed for successful fabrication of CuS nanostructures with various morphologies. At the ionic liquids (ILs)-modulated CHCl{sub 3}-H{sub 2}O interface, copper cupferronate [Cu(cup){sub 2}] in CHCl{sub 3} reacted with thiourea in water to generate CuS nanostructures via a solvothermal reaction process. The effects of alkyl chain length of imidazolium cations and nature of anions of the ILs, molar ratio of Cu(cup){sub 2} to thiourea, the reaction temperature and time on the morphology of the products were studied systematically. It was shown that by changing alkyl chain length of imidazolium cations and nature of anions of the ILs,more » CuS nanostructures with various morphologies, including flowers, urchins, large nanodisks and nanoparticles, could be obtained at the liquid-liquid interface, and the ILs played important template roles in directing the formation of CuS nanostructures. Furthermore, the as-prepared CuS samples exhibited high catalytic activity for photodegradation of methyl orange and thermal decomposition of ammonium perchlorate. - Graphical abstract: At the ionic liquids-modulated CHCl{sub 3}-H{sub 2}O interface, the CuS nanostructures with the various morphologies of flowers, urchins, large nanodisks and nanoparticles have been successfully prepared via a solvothermal reaction process. Highlights: Black-Right-Pointing-Pointer The properties of oil-H{sub 2}O interface can be modulated by employing different ILs. Black-Right-Pointing-Pointer The modulated interface has been used to prepare CuS nanostructures with various morphologies. Black-Right-Pointing-Pointer The CuS samples exhibited high catalytic activity for the photodegradation of methyl orange.« less

Trophic divergence despite morphological convergence in a continental radiation of snakes

PubMed Central

Grundler, Michael C.; Rabosky, Daniel L.

2014-01-01

Ecological and phenotypic convergence is a potential outcome of adaptive radiation in response to ecological opportunity. However, a number of factors may limit convergence during evolutionary radiations, including interregional differences in biogeographic history and clade-specific constraints on form and function. Here, we demonstrate that a single clade of terrestrial snakes from Australia—the oxyuranine elapids—exhibits widespread morphological convergence with a phylogenetically diverse and distantly related assemblage of snakes from North America. Australian elapids have evolved nearly the full spectrum of phenotypic modalities that occurs among North American snakes. Much of the convergence appears to involve the recurrent evolution of stereotyped morphologies associated with foraging mode, locomotion and habitat use. By contrast, analysis of snake diets indicates striking divergence in feeding ecology between these faunas, partially reflecting regional differences in ecological allometry between Australia and North America. Widespread phenotypic convergence with the North American snake fauna coupled with divergence in feeding ecology are clear examples of how independent continental radiations may converge along some ecological axes yet differ profoundly along others. PMID:24920479

Trophic divergence despite morphological convergence in a continental radiation of snakes.

PubMed

Grundler, Michael C; Rabosky, Daniel L

2014-07-22

Ecological and phenotypic convergence is a potential outcome of adaptive radiation in response to ecological opportunity. However, a number of factors may limit convergence during evolutionary radiations, including interregional differences in biogeographic history and clade-specific constraints on form and function. Here, we demonstrate that a single clade of terrestrial snakes from Australia--the oxyuranine elapids--exhibits widespread morphological convergence with a phylogenetically diverse and distantly related assemblage of snakes from North America. Australian elapids have evolved nearly the full spectrum of phenotypic modalities that occurs among North American snakes. Much of the convergence appears to involve the recurrent evolution of stereotyped morphologies associated with foraging mode, locomotion and habitat use. By contrast, analysis of snake diets indicates striking divergence in feeding ecology between these faunas, partially reflecting regional differences in ecological allometry between Australia and North America. Widespread phenotypic convergence with the North American snake fauna coupled with divergence in feeding ecology are clear examples of how independent continental radiations may converge along some ecological axes yet differ profoundly along others. © 2014 The Author(s) Published by the Royal Society. All rights reserved.

Corn-like indium tin oxide nanostructures: fabrication, characterization and formation mechanism

NASA Astrophysics Data System (ADS)

Wu, Xu; Wang, Yihua; Yang, Bin

2015-11-01

Electrospinning is a simple but efficient procedure enabling the parallel fabrication of a multitude of inorganic fibers. But the precise control of the fiber's morphology, which seriously affects the electrical, optical and other important properties of such electrospun materials, is still less developed. The creation of nanoscale indium tin oxide fibers with corn-like geometry (corn-like ITO NFs) by our group has provided a good example to show how to modify the morphologies and properties of nanofibers by means of tailoring the fiber's compositions. Here we show that in the fabrication of corn-like ITO NFs, the usage of different solvents N, N-dimethylformamide (DMF) and deionized water, as well as the calcination temperature, can also lead to dramatic morphology changes, from ribbon-like to cylindrical and then to corn-like. The resultant nanoribbons and nanoscale corn-like fibers exhibit different photoluminescence properties. We find that the morphology of the as-spun fibers is closely related to the vapor pressure of the solvent we used, and the generation of ITO crystals sensitively depends on the calcination temperature, which both are critical for the morphology and properties of the final products. Thus, we demonstrate that the formation of this unprecedented nanostructure is determined by the combined effect of the precursor chemical composition, solvent and calcination temperature.

Controlled synthesis of nanostructured molybdenum oxide electrodes for high performance supercapacitor devices

NASA Astrophysics Data System (ADS)

Maheswari, Nallappan; Muralidharan, Gopalan

2017-09-01

Well defined crystallographic and one dimensional morphological structure of molybdenum oxide were successfully synthesized by adjusting the duration of hydrothermal treatment. The prepared molybdenum oxide was examined through XRD, SEM, FTIR, TEM, BET and electrochemical studies. The XRD patterns illustrate that MoOx prepared by variying the hydrothermal reaction time are in different crystallographic structure of MoyOx (Mo8O23 and MoO3). SEM studies reveal the different morphological structures ranging from flake like morphology to nanorods. TEM images confirm the excellent nanorod structure. The nanorod structure ensures good cyclic behaviour with maximum capacitance of 1080 F g-1 at a current density of 2 A g-1. This large capacity of the MoO3 nanostructures enabled fabrication of symmetric and asymmertic supercapacitor devices. The asymmertic device exhibits a maximum specific capacitance of 145 F g-1 at 2 mV s-1 with highest energy density of 38.6 W h kg-1 at 374.7 W kg-1 power density.

Nanoporous Ag prepared from the melt-spun Cu-Ag alloys

NASA Astrophysics Data System (ADS)

Li, Guijing; Song, Xiaoping; Sun, Zhanbo; Yang, Shengchun; Ding, Bingjun; Yang, Sen; Yang, Zhimao; Wang, Fei

2011-07-01

Nanoporous Ag ribbons with different morphology and porosity were achieved by the electrochemical corrosion of the melt-spun Cu-Ag alloys. The Cu-rich phase in the alloys was removed, resulting in the formation of the nanopores distributed across the whole ribbon. It is found that the structures, morphology and porosity of the nanoporous Ag ribbons were dependent on the microstructures of the parent alloys. The most of ligaments presented a rod-like shape due to the formation of pseudoeutectic microstructure in the melt-spun Cu 55Ag 45 and Cu 70Ag 30 alloys. For nanoporous Ag prepared from Cu 85Ag 15 alloys, the ligaments were camber-like because of the appearance of the divorced microstructures. Especially, a novel bamboo-grove-like structure could be observed at the cross-section of the nanoporous Ag ribbons. The experiment reveals that nanoporous Ag ribbons exhibited excellent enhancement of surface-enhanced Raman scattering (SERS) effect, but a slight difference existed due to the discrepancy of their morphology.

Comparative Morphological Analysis of the Immature Stages of the Grass Blue Butterflies Zizeeria and Zizina (Lepidoptera: Lycaenidae).

PubMed

Gurung, Raj D; Iwata, Masaki; Hiyama, Atsuki; Taira, Wataru; Degnan, Bernard; Degnan, Sandie; Otaki, Joji M

2016-08-01

The pale grass blue butterfly has been used to assess the biological effects of the Fukushima nuclear accident. Zizeeria and Zizina are two closely related genera of grass blue butterflies that are widely distributed in tropical to temperate Asia, Australia, and Africa, making them suitable environmental indicators for these areas. However, the morphological features of the immature stages have been examined only in fragmentary fashion. Here, we reared Zizeeria maha argia, Zizeeria maha okinawana, Zizeeria karsandra karsandra, Zizina emelina emelina, Zizina otis labradus, and Zizina otis riukuensis using a standard rearing method that was developed for Zizeeria maha, and comparatively identified morphological traits to effectively classify the immature stages of species or subspecies. Morphological information on these and other subspecies including Zizeeria knysna knysna and Zizina otis antanossa from Africa was also collected from literature. The subspecies were all reared successfully. The subspecies all had dorsal nectary and tentacle organs with similar morphology. For the subspecies of Zizeeria maha, only minor morphological differences were noted. Similarly, the subspecies of Zizina otis shared many traits. Most importantly, Zizeeria and Zizina differed in the shape of the sensory hairs that accompany the dorsal nectary organ; Zizeeriahad pointed hairs, and Zizina had blunt or rounded hairs. However, Zizina emelina exhibited several intermediate features between these two genera. Overall, the morphological traits did not completely reflect the conventional systematic relationships. This comparative study describes the efficient rearing of the grass blue butterflies and provides a morphological basis for the use of these species as environmental indicators.

A comparative study of the influence of alpha-lactose monohydrate particle morphology on granule and tablet properties after roll compaction/dry granulation.

PubMed

Grote, Simon; Kleinebudde, Peter

2018-05-29

The influence of particle morphology and size of alpha-lactose monohydrate on dry granules and tablets was studied. Four different morphologies were investigated: Two grades of primary crystals, which differed in their particle size and structure (compact crystals vs. agglomerates). The materials were roll compacted at different specific compaction forces and changes in the particle size distribution and the specific surface area were measured. Afterwards, two fractions of granules were pressed to tablets and the tensile strength was compared to that from tablets compressed from the raw materials. The specific surface area was increased induced by roll compaction/dry granulation for all materials. At increased specific compaction forces, the materials showed sufficient size enlargement. The morphology of lactose determined the strength of direct compressed tablets. In contrast, the strength of granule tablets was leveled by the previous compression step during roll compaction/dry granulation. Thus, the tensile strength of tablets compressed directly from the powder mixtures determined whether materials exhibited a loss in tabletability after roll compaction/dry granulation or not. The granule size had only a slight influence on the strength of produced tablets. In some cases, the fraction of smaller granules showed a higher tensile strength compared to the larger fraction.

New Features for Neuron Classification.

PubMed

Hernández-Pérez, Leonardo A; Delgado-Castillo, Duniel; Martín-Pérez, Rainer; Orozco-Morales, Rubén; Lorenzo-Ginori, Juan V

2018-04-28

This paper addresses the problem of obtaining new neuron features capable of improving results of neuron classification. Most studies on neuron classification using morphological features have been based on Euclidean geometry. Here three one-dimensional (1D) time series are derived from the three-dimensional (3D) structure of neuron instead, and afterwards a spatial time series is finally constructed from which the features are calculated. Digitally reconstructed neurons were separated into control and pathological sets, which are related to three categories of alterations caused by epilepsy, Alzheimer's disease (long and local projections), and ischemia. These neuron sets were then subjected to supervised classification and the results were compared considering three sets of features: morphological, features obtained from the time series and a combination of both. The best results were obtained using features from the time series, which outperformed the classification using only morphological features, showing higher correct classification rates with differences of 5.15, 3.75, 5.33% for epilepsy and Alzheimer's disease (long and local projections) respectively. The morphological features were better for the ischemia set with a difference of 3.05%. Features like variance, Spearman auto-correlation, partial auto-correlation, mutual information, local minima and maxima, all related to the time series, exhibited the best performance. Also we compared different evaluators, among which ReliefF was the best ranked.

Ag films deposited on Si and Ti: How the film-substrate interaction influences the nanoscale film morphology

NASA Astrophysics Data System (ADS)

Ruffino, F.; Torrisi, V.

2017-11-01

Submicron-thick Ag films were sputter deposited, at room temperature, on Si, covered by the native SiO2 layer, and on Ti, covered by the native TiO2 layer, under normal and oblique deposition angle. The aim of this work was to study the morphological differences in the grown Ag films on the two substrates when fixed all the other deposition parameters. In fact, the surface diffusivity of the Ag adatoms is different on the two substrates (higher on the SiO2 surface) due to the different Ag-SiO2 and Ag-TiO2 atomic interactions. So, the effect of the adatoms surface diffusivity, as determined by the adatoms-substrate interaction, on the final film morphology was analyzed. To this end, microscopic analyses were used to study the morphology of the grown Ag films. Even if the homologous temperature prescribes that the Ag film grows on both substrates in the zone I described by the structure zone model some significant differences are observed on the basis of the supporting substrate. In the normal incidence condition, on the SiO2/Si surface a dense close-packed Ag film exhibiting a smooth surface is obtained, while on the TiO2/Ti surface a more columnar film morphology is formed. In the oblique incidence condition the columnar morphology for the Ag film occurs both on SiO2/Si and TiO2/Ti but a higher porous columnar film is obtained on TiO2/Ti due to the lower Ag diffusivity. These results indicate that the adatoms diffusivity on the substrate as determined by the adatom-surface interaction (in addition to the substrate temperature) strongly determines the final film nanostructure.

Ultrathin NiGe films prepared via catalytic solid-vapor reaction of Ni with GeH(4).

PubMed

Peter, Antony P; Opsomer, Karl; Adelmann, Christoph; Schaekers, Marc; Meersschaut, Johan; Richard, Olivier; Vaesen, Inge; Moussa, Alain; Franquet, Alexis; Zsolt, Tokei; Van Elshocht, Sven

2013-10-09

A low-temperature (225-300 °C) solid-vapor reaction process is reported for the synthesis of ultrathin NiGe films (∼6-23 nm) on 300 mm Si wafers covered with thermal oxide. The films were prepared via catalytic chemical vapor reaction of germane (GeH4) gas with physical vapor deposited (PVD) Ni films of different thickness (2-10 nm). The process optimization by investigating GeH4 partial pressure, reaction temperature, and time shows that low resistive, stoichiometric, and phase pure NiGe films can be formed within a broad window. NiGe films crystallized in an orthorhombic structure and were found to exhibit a smooth morphology with homogeneous composition as evidenced by glancing angle X-ray diffraction (GIXRD), scanning electron microscopy (SEM), atomic force microscopy (AFM), and Rutherford back-scattering (RBS) analysis. Transmission electron microscopy (TEM) analysis shows that the NiGe layers exhibit a good adhesion without voids and a sharp interface on the thermal oxide. The NiGe films were found to be morphologically and structurally stable up to 500 °C and exhibit a resistivity value of 29 μΩ cm for 10 nm NiGe films.

Polymorphisms of blood forms and in vitro metacyclogenesis of Trypanosoma cruzi I, II, and IV.

PubMed

Abegg, Camila Piva; Abreu, Ana Paula de; Silva, Juliane Lopes da; Araújo, Silvana Marques de; Gomes, Mônica Lúcia; Ferreira, Érika Cristina; Toledo, Max Jean de Ornelas

2017-05-01

Trypanosoma cruzi is the etiologic agent of American trypanosomiasis has broad biological and genetic diversity. Remaining to be studied are polymorphisms of the blood forms and metacyclogenesis of different T. cruzi discrete typing units (DTUs). Our goal was to evaluate the relationship between T. cruzi DTUs, the morphology of blood trypomastigotes, and in vitro metacyclogenesis. T. cruzi strains that pertained to DTUs TcI, TcII, and TcIV from different Brazilian states were used. Parameters that were related to the morphology of eight strains were assessed in thin blood smears that were obtained from mice that were inoculated with blood or culture forms, depending on strain. The metacyclogenesis of 12 strains was measured using smears with Liver Infusion Tryptose culture medium and M16 culture medium (which is poor in nutrients and has a low pH) at the exponential phase of growth, both stained with Giemsa. The morphological pattern of TcII strains was consistent with broad forms of the parasite. In TcIV strains, slender forms predominated. The Y strain (TcII) was morphologically more similar to TcIV. Significant differences in polymorphisms were observed between DTUs. Metacyclogenesis parameters, although displaying large standard deviations, differed between the DTUs, with the following descending rank order: TcII > TcI > TcIV. The mean numbers of metacyclic trypomastigotes for TcII were significantly higher than the other DTUs. Although the DTUs presented overlapping characteristics, the general pattern was that different DTUs exhibited significantly different morphologies and metacyclogenesis, suggesting that the genetic diversity of T. cruzi could be related to parameters that are associated with the evolution of infection in mammalian hosts and its ability to disperse in nature. Copyright © 2017 Elsevier Inc. All rights reserved.

A numerical retroaction model relates rocky coast erosion to percolation theory

NASA Astrophysics Data System (ADS)

Sapoval, B.; Baldassarri, A.

2011-12-01

Rocky coasts are estimated to represent 75% of the world's shorelines [1]. We discuss various situations where the formation of rocky coast morphology could be attributed to the retroaction of the coast morphology on the erosive power of the see. In the case of rocky coasts, erosion can spontaneously create irregular seashores. But, in turn, the geometrical irregularity participates to the damping of sea-waves, decreasing the average wave amplitude and erosive power. There may then exist a mutual self-stabilization of the waves amplitude together with the irregular morphology of the coast. A simple model of such stabilization is discussed. It leads, through a complex avalanche dynamics of the earth-sea interface, to the spontaneous appearance of an irregular sea-shore. The final coast morphology is found to depend on the morphology/damping coupling of the coast and on the possible existence of built-in correlations within the coast lithologic properties. In the limit case where the morphology/damping coupling is weak and when the earth lithology distribution exhibit only short range correlations, the process spontaneously build fractal morphologies with a dimension close to 4/3 [2]. This dimension refers to the dimension of the accessible perimeter in percolation theory. However, even rugged but non-fractal sea-coasts morphology may emerge for strong damping or during the erosion process. When the distributions of the lithologies exhibit long range correlations, a variety of complex morphologies are obtained which mimics observed coastline complexity, well beyond simple fractality. This approach, which links erosion of rocky coasts to percolation theory, provide a natural frame to explain the frequent field observation that the statistics of erosion events follow power law behavior. In a somewhat different perspective, the design of breakwaters is suggested to be improved by using global irregular geometry with features sizes of the order of the wave-length of the sea oscillations. [1] R. A. Davis, Jr, D. M. Fitzgerald, Beaches and Coasts,(Blackwell, Oxford 2004). [2] B. Sapoval, A. Baldassarri, A. Gabrielli, Self-stabilized Fractality of Sea-coasts through Erosion, Phys. Rev. Lett. 93, 098501 (2004).

'Ogura'-based 'CMS' lines with different nuclear backgrounds of cabbage revealed substantial diversity at morphological and molecular levels.

PubMed

Parkash, Chander; Kumar, Sandeep; Singh, Rajender; Kumar, Ajay; Kumar, Satish; Dey, Shyam Sundar; Bhatia, Reeta; Kumar, Raj

2018-01-01

A comprehensive study on characterization and genetic diversity analysis was carried out in 16 'Ogura'-based 'CMS' lines of cabbage using 14 agro-morphological traits and 29 SSR markers. Agro-morphological characterization depicted considerable variations for different horticultural traits studied. The genotype, ZHA-2, performed better for most of the economically important quantitative traits. Further, gross head weight (0.76), head length (0.60) and head width (0.83) revealed significant positive correlation with net head weight. Dendrogram based on 10 quantitative traits exhibited considerable diversity among different CMS lines and principle component analysis (PCA) indicated that net and gross head weight, and head length and width are the main components of divergence between 16 CMS lines of cabbage. In molecular study, a total of 58 alleles were amplified by 29 SSR primers, averaging to 2.0 alleles in each locus. High mean values of Shannon's Information index (0.62), expected (0.45) and observed (0.32) heterozygosity and polymorphic information content (0.35) depicted substantial polymorphism. Dendrogram based on Jaccard's similarity coefficient constructed two major groups and eight sub-groups, which revealed substantial diversity among different CMS lines. In overall, based on agro-morphological and molecular studies genotype RRMA, ZHA-2 and RCA were found most divergent. Hence, they have immense potential in future breeding programs for the high-yielding hybrid development in cabbage.

Population genetic structure and its implications for adaptive variation in memory and the hippocampus on a continental scale in food-caching black-capped chickadees.

PubMed

Pravosudov, V V; Roth, T C; Forister, M L; Ladage, L D; Burg, T M; Braun, M J; Davidson, B S

2012-09-01

Food-caching birds rely on stored food to survive the winter, and spatial memory has been shown to be critical in successful cache recovery. Both spatial memory and the hippocampus, an area of the brain involved in spatial memory, exhibit significant geographic variation linked to climate-based environmental harshness and the potential reliance on food caches for survival. Such geographic variation has been suggested to have a heritable basis associated with differential selection. Here, we ask whether population genetic differentiation and potential isolation among multiple populations of food-caching black-capped chickadees is associated with differences in memory and hippocampal morphology by exploring population genetic structure within and among groups of populations that are divergent to different degrees in hippocampal morphology. Using mitochondrial DNA and 583 AFLP loci, we found that population divergence in hippocampal morphology is not significantly associated with neutral genetic divergence or geographic distance, but instead is significantly associated with differences in winter climate. These results are consistent with variation in a history of natural selection on memory and hippocampal morphology that creates and maintains differences in these traits regardless of population genetic structure and likely associated gene flow. Published 2012. This article is a US Government work and is in the public domain in the USA.

3-Rooted Maxillary First Premolars: An Ex Vivo Study of External and Internal Morphologies.

PubMed

Beltes, Panagiotis; Kalaitzoglou, Maria-Elpida; Kantilieraki, Eleni; Beltes, Charalampos; Angelopoulos, Christos

2017-08-01

This study aimed to analyze the external and internal morphologies of 3-rooted maxillary first premolars using cone-beam computed tomographic (CBCT) imaging. Fifty-six three-rooted maxillary first premolars were imaged by CBCT imaging and classified into 4 groups on the basis of external root morphology. Internal morphologic features, including the shapes of the buccal and palatal orifices and distances of bifurcation of the buccal-palatal and mesiobuccal-distobuccal root canals from the cementoenamel junction (CEJ), were measured. The teeth were classified into 4 groups on the basis of external morphology: group A, separation of the buccal and palatal roots with bifurcation of the former into the mesiobuccal and distobuccal roots (n = 22); group B, fusion of 2 buccal roots with the palatal root being separate (n = 19); group C, complete or partial fusion of the distobuccal and palatal roots (n = 9); and group D, fusion of all 3 roots (n = 6). The buccal orifice was mainly triangular/heart shaped. The distance of bifurcation of the buccal-palatal root canals from the CEJ in group A differed significantly from those in groups B and C (P < .05). There were significant differences in the distance of bifurcation of the mesiobuccal-distobuccal root canals from the CEJ among groups A, B, and C (P < .05). Four teeth exhibited C-shaped root canal systems of different configurations. The external and internal morphologies of 3-rooted maxillary first premolars vary considerably. Copyright © 2017 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Structural, Optical and Ethanol Sensing Properties of Dy-Doped SnO2 Nanoparticles

NASA Astrophysics Data System (ADS)

Shaikh, F. I.; Chikhale, L. P.; Nadargi, D. Y.; Mulla, I. S.; Suryavanshi, S. S.

2018-04-01

We report a facile co-precipitation synthesis of dysprosium (Dy3+) doped tin oxide (SnO2) thick films and their use as gas sensors. The doping percentage (Dy3+) was varied from 1 mol.% to 4 mol.% with the step of 1 mol.%. As-produced material with varying doping levels were sintered in air; and by using a screen printing technique, their thick films were developed. Prior to sensing performance investigations, the films were examined for structural, morphological and compositional properties using x-ray diffraction, a field emission scanning electron microscope, a transmission electron microscope, selected area electron diffraction, energy dispersive analysis by x-rays, Fourier transform infrared spectroscopy and Raman spectroscopic techniques. The structural analyses revealed formation of single phase nanocrystalline material with tetragonal rutile structure of SnO2. The morphological analyses confirmed the nanocrystalline porous morphology of as-developed material. Elemental analysis defined the composition of material in accordance with the doping concentration. The produced sensor material exhibited good response towards different reducing gases (acetone, ethanol, LPG, and ammonia) at different operating temperatures. The present study confirms that the Dy3+ doping in SnO2 enhances the response towards ethanol with reduction in operating temperature. Particularly, 3 mol.% Dy3+ doped sensor exhibited the highest response (˜ 92%) at an operating temperature of 300°C with better selectivity, fast response (˜ 13 s) and recovery (˜ 22 s) towards ethanol.

The evolution of cranial base and face in Cercopithecoidea and Hominoidea: Modularity and morphological integration.

PubMed

Profico, Antonio; Piras, Paolo; Buzi, Costantino; Di Vincenzo, Fabio; Lattarini, Flavio; Melchionna, Marina; Veneziano, Alessio; Raia, Pasquale; Manzi, Giorgio

2017-12-01

The evolutionary relationship between the base and face of the cranium is a major topic of interest in primatology. Such areas of the skull possibly respond to different selective pressures. Yet, they are often said to be tightly integrated. In this paper, we analyzed shape variability in the cranial base and the facial complex in Cercopithecoidea and Hominoidea. We used a landmark-based approach to single out the effects of size (evolutionary allometry), morphological integration, modularity, and phylogeny (under Brownian motion) on skull shape variability. Our results demonstrate that the cranial base and the facial complex exhibit different responses to different factors, which produces a little degree of morphological integration between them. Facial shape variation appears primarily influenced by body size and sexual dimorphism, whereas the cranial base is mostly influenced by functional factors. The different adaptations affecting the two modules suggest they are best studied as separate and independent units, and that-at least when dealing with Catarrhines-caution must be posed with the notion of strong cranial integration that is commonly invoked for the evolution of their skull shape. © 2017 Wiley Periodicals, Inc.

Color and Morphology of Lava Flows on Io

NASA Astrophysics Data System (ADS)

Piatek, Jennifer L.; McElfresh, Sarah B. Z.; Byrnes, Jeffrey M.; Hale, Amy Snyder; Crown, David A.

2000-12-01

Analyses of color and morphologic changes in Voyager images of lava flows on Io were conducted to extend previous flow studies to additional volcanoes in preparation for comparison to Galileo data. Blue and orange filter images of Atar, Daedalus, and Ra Paterae were examined to identify systematic downflow decreases in blue/orange reflectivity suggested in earlier studies as diagnostic of color changes in cooled sulfur flows. Analyses of the color and morphology of 21 lava flows were conducted at these volcanoes, with additional morphologic analysis of lava flows at Agni, Masaaw, Mbali, Shoshu, and Talos Paterae. A total of 66 lava flows of up to 245 km in length were mapped to identify morphologic changes consistent with the rheologic changes expected to occur in sulfur flows. Although downflow color changes are observed, the trends are not consistent, even at the same edifice. Individual flows exhibit a statistically significant increase in blue/orange ratio, decrease in blue/orange ratio, or a lack of progressive downflow color variation. Color changes have similar magnitudes downflow and across flow, and the color ranges observed are similar from volcano to volcano, suggesting that similar processes are controlling color ratios at these edifices. In addition, using flow widening and branching as an indicator of the low viscosity exhibited by sulfur cooling from high temperatures, these flows do not exhibit morphologic changes consistent with the systematic behavior expected from the simple progressive cooling of sulfur.

Distinct phylogeographic structure recognized within Desmazierella acicola.

PubMed

Martinović, Tijana; Koukol, Ondřej; Hirose, Dai

2016-01-01

Desmazierella acicola (anamorph Verticicladium trifidum, Chorioactidaceae) represents a frequent colonizer of pine needles in litter. Considering the global diversity and distribution of pine species, we expected different phylogenetic lineages to exist in different geographical and climatic areas inhabited by these hosts. We compared DNA sequence data with phenotypic characteristics (morphology of the anamorph and growth at three different temperatures) of 43 strains isolated mostly from pine and also spruce needle litter sampled in various geographical areas. Analyses of ITS rDNA recovered eight geographically structured lineages. Fragments of genes for the translation elongation factor 1-α, and the second largest subunit of RNA polymerase II reproduced similar lineages, although not all of them were monophyletic. The similarity in ITS sequences among the clade with samples from Continental-Atlantic Europe and four other clades was lower than 95%. Several lineages exhibit also a tendency toward host specificity to a particular pine species. Growth tests at different temperatures indicated a different tolerance to specific climatic conditions in different geographic areas. However, the surveyed phenotypic characteristics also showed high variation within lineages, most evident in the morphology of the anamorph. Until a morphological study of the teleomorph is carried out, all of these lineages should be treated as distinct populations within a single species. © 2016 by The Mycological Society of America.

Cellulose effects on morphology and elasticity of Vibrio fischeri biofilms.

PubMed

Ziemba, Christopher; Shabtai, Yael; Piatkovsky, Maria; Herzberg, Moshe

2016-01-01

Cellulose effects on Vibrio fischeri biofilm morphology were tested for the wild-type and two of its isogenic mutants that either exhibit increased cellulose production or do not produce cellulose at all. Confocal laser scanning microscopy imaging of each biofilm revealed that total sessile volume increases with cellulose expression, but the size of colonies formed with cellulose was smaller, creating a more diffuse biofilm. These morphological differences were not attributed to variations in bacterial deposition, extracellular polymeric substances affinity to the surface or bacterial growth. A positive correlation was found between cellulose expression, Young's (elastic) modulus of the biofilm analyzed with atomic force microscope and shear modulus of the related extracellular polymeric substances layers analyzed with quartz crystal microbalance with dissipation monitoring. Cellulose production also correlated positively with concentrations of extracellular DNA. A significant negative correlation was observed between cellulose expression and rates of diffusion through the extracellular polymeric substances. The difference observed in biofilm morphology is suggested as a combined result of cellulose and likely extracellular DNA (i) increasing biofilm Young's modulus, making shear removal more difficult, and (ii) decreased diffusion rate of nutrients and wastes into and out of the biofilm, which effectively limits colony size.

Geographical variation in the skeletal morphology of red jungle fowl.

PubMed

Endo, H; Tsunekawa, N; Sonoe, M; Sasaki, Tї; Ogawa, H; Amano, T; Nguyen, T S; Phimphachanhvongsod, V; Kudo, K; Yonezawa, T; Akishinonomiya, F

2017-08-01

1. The skulls and postcranial skeletons of the red jungle fowl (Gallus gallus) were compared osteometrically between the populations from North and South Vietnam, North and Central Laos and Southeast Bangladesh. The populations include the three subspecies of G. g. spadiceus, G. g. gallus and G. g. murghi and were sampled to reveal the geographical morphological variations among populations in G. gallus. 2. The morphometric characteristics of subspecies murghi could be clearly distinguished from those of the other subspecies using a canonical discriminant analysis. However, the size and shape of the skull of the gallus population from South Vietnam were not statistically different from that of the subspecies spadiceus from North Laos. The canonical discriminant scores also clearly indicated that there were morphological similarities in the skulls of the populations from North Laos and South Vietnam. 3. From the results, therefore, it is concluded that red jungle fowls do not exhibit high levels of osteometric variation between geographical localities at least within the Indochinese Peninsula. 4. This contrasts with previous studies which have described these subspecies as having various external morphological differences and have argued that zoogeographical barriers exist between the north and south areas of the Indochinese Peninsula.

Spectral analysis of crater central peak material (ccp)

NASA Astrophysics Data System (ADS)

Galiano, A.; Palomba, E.; Longobardo, A.; De Sanctis, M. C.; Raponi, A.; Tosi, F.; Ammannito, E.; Raymond, C. A.; Russell, C. T.

2017-09-01

We spectrally investigated 32 ccp units, which stand out in geologic maps of Ceres as they exhibit a different color and morphology with respect to the surrounding floor. We focus our attention on spectral parameters related to Mg-phyllosilicates (2.7 μm band), ammoniated phyllosilicates (3.1 μm band) and carbonates (bands at about 3.4 and 4.0 μm).

From 2D to 3D: The morphology, proliferation and differentiation of MC3T3-E1 on silk fibroin/chitosan matrices.

PubMed

Li, Da-Wei; He, Feng-Li; He, Jin; Deng, Xudong; Liu, Ya-Li; Liu, Yang-Yang; Ye, Ya-Jing; Yin, Da-Chuan

2017-12-15

It has been widely accepted that cell culture in two-dimensional (2D) conditions may not be able to represent growth in three-dimensional (3D) conditions. Systematic comparisons between 2D and 3D cell cultures are needed to appropriately use the existing 2D results. In this work, we conducted a comparative study between 2D and 3D cell cultures of MC3T3-E1 using the same type of material (a mixture of silk fibroin (SF) and chitosan (CS)). Our results showed 3D SF/CS scaffold exhibited different effects on cell culture compared with the 2D cases. 1) The cells grown in 3D scaffold showed multiple morphologies. 2) The proliferation of cells in 3D scaffold was long-term and sustainable. 3) Cell differentiation occurred throughout the entire 3D scaffold. The results showed that cell culture in 3D SF/CS scaffold exhibited different features than 2D cases and 3D SF/CS scaffold could be a promising material for 3D cell culture. Copyright © 2017 Elsevier Ltd. All rights reserved.

Fluid Mechanical Properties of Silkworm Fibroin Solutions

NASA Astrophysics Data System (ADS)

Matsumoto, Akira

2005-11-01

The aqueous solution behavior of silk fibroin is of interest due to the assembly and processing of this protein related to the spinning of protein fibers that exhibit remarkable mechanical properties. To gain insight into the origins of this functional feature, it is desired to determine how the protein behaves under a range of solution conditions. Pure fibroin at different concentrations in water was studied for surface tension, as a measure of surfactancy. In addition, shear induced changes on these solutions in terms of structure and morphology was also determined. Fibroin solutions exhibited shear rate-sensitive viscosity changes and precipitated at a critical shear rate where a dramatic increase of 75-150% of the initial value was observed along with a decrease in viscosity. In surface tension measurements, critical micelle concentrations were in the range of 3-4% w/v. The influence of additional factors, such as sericin protein, divalent and monovalent cations, and pH on the solution behavior in relation to structural and morphological features will also be described.

Effects of surface morphology of ZnO seed layers on growth of ZnO nanostructures prepared by hydrothermal method and annealing.

PubMed

Yim, Kwang Gug; Kim, Min Su; Leem, Jae-Young

2013-05-01

ZnO nanostructures were grown on Si (111) substrates by a hydrothermal method. Prior to growing the ZnO nanostructures, ZnO seed layers with different post-heat temperatures were prepared by a spin-coating process. Then, the ZnO nanostructures were annealed at 500 degrees C for 20 min under an Ar atmosphere. Scanning electron microscopy (SEM), X-ray diffraction (XRD), and photoluminescence (PL) were carried out at room temperature (RT) to investigate the structural and optical properties of the as-grown and annealed ZnO nanostructures. The surface morphologies of the seed layers changed from a smooth surface to a mountain chain-like structure as the post-heating temperatures increased. The as-grown and annealed ZnO nanostructures exhibited a strong (002) diffraction peak. Compared to the as-grown ZnO nanostructures, the annealed ZnO nanostructures exhibited significantly strong enhancement in the PL intensity ratio by almost a factor of 2.

Influence of Oxygen ions irradiation on Polyaniline/Single Walled Carbon Nanotubes nanocomposite

NASA Astrophysics Data System (ADS)

Patil, Harshada K.; Deshmukh, Megha A.; Gaikwad, Sumedh D.; Bodkhe, Gajanan A.; Asokan, K.; Yasuzawa, Mikito; Koinkar, Pankaj; Shirsat, Mahendara D.

2017-01-01

Influence of Oxygen ions (100 MeV) irradiation on Polyaniline (PANI)/Single Walled Carbon Nanotubes (SWNTs) nanocomposite was studied in the present investigation. PANI/SWNTs nanocomposite was synthesized by electrochemical Cyclic Voltammetry technique. Nanocomposite was exposed under SHI irradiation of Oxygen (100 MeV) ions for three different fluences such as 1×1010 ions/cm2, 5×1010 ions/cm2 and 1×1011 ions/cm2. The SHI irradiated PANI/SWNTs nanocomposite was investigated by using morphological (AFM), structural (XRD) and spectroscopy (FTIR) characterization. AFM study exhibits effects of SHI irradiation on morphology of the nanocomposite and root mean square roughness of the nanocomposite is observed to be decreased as fluence was increased. The FTIR absorption spectrum exhibits formation of new functional sites with the increase in intensity of absorption peaks, due to SHI irradiation. X-Ray Diffraction studies show a gradual decrease in the crystalline nature of the nanocomposite upon irradiation.

Assessing heterogeneity of peroxisomes: isolation of two subpopulations from rat liver.

PubMed

Islinger, Markus; Abdolzade-Bavil, Afsaneh; Liebler, Sven; Weber, Gerhardt; Völkl, Alfred

2012-01-01

Peroxisomes exhibit a heterogeneous morphological appearance in rat liver tissue. In this respect, the isolation and subsequent biochemical characterization of peroxisome species from different subcellular prefractions should help to solve the question of whether peroxisomes indeed diverge into functionally specialized subgroups in one tissue. As a means to address this question, we provide a detailed separation protocol for the isolation of peroxisomes from both the light (LM-Po) and the heavy (HM-Po) mitochondrial prefraction for their subsequent comparative analysis. Both isolation strategies rely on centrifugation in individually adapted Optiprep gradients. In case of the heavy mitochondrial fraction, free flow electrophoresis is appended as an additional separation step to yield peroxisomes of sufficient purity. In view of their morphology, peroxisomes isolated from both fractions are surrounded by a continuous single membrane and contain a gray-opaque inner matrix. However, beyond this overall similar appearance, HM-Po exhibit a smaller average diameter, float at lower density, and show a more negative average membrane charge when compared to LM-Po.

Peculiarity of two thermodynamically-stable morphologies and their impact on the efficiency of small molecule bulk heterojunction solar cells

DOE PAGES

Herath, Nuradhika; Das, Sanjib; Keum, Jong K.; ...

2015-08-28

Structural characteristics of the active layers in organic photovoltaic (OPV) devices play a critical role in charge generation, separation and transport. Here we report on morphology and structural control of p-DTS(FBTTh 2) 2:PC 71BM films by means of thermal annealing and 1,8-diiodooctane (DIO) solvent additive processing, and correlate it to the device performance. By combining surface imaging with nanoscale depth-sensitive neutron reflectometry (NR) and X-ray diffraction, three-dimensional morphologies of the films are reconstituted with information extending length scales from nanometers to microns. DIO promotes the formation of a well-mixed donor-acceptor vertical phase morphology with a large population of small p-DTS(FBTTh2)2more » nanocrystals arranged in an elongated domain network of the film, thereby enhancing the device performance. In contrast, films without DIO exhibit three-sublayer vertical phase morphology with phase separation in agglomerated domains. Our findings are supported by thermodynamic description based on the Flory-Huggins theory with quantitative evaluation of pairwise interaction parameters that explain the morphological changes resulting from thermal and solvent treatments. Our study reveals that vertical phase morphology of small-molecule based OPVs is significantly different from polymer-based systems. Lastly, the significant enhancement of morphology and information obtained from theoretical modeling may aid in developing an optimized morphology to enhance device performance for OPVs.« less

Comparative neuronal morphology of the cerebellar cortex in afrotherians, carnivores, cetartiodactyls, and primates

PubMed Central

Jacobs, Bob; Johnson, Nicholas L.; Wahl, Devin; Schall, Matthew; Maseko, Busisiwe C.; Lewandowski, Albert; Raghanti, Mary A.; Wicinski, Bridget; Butti, Camilla; Hopkins, William D.; Bertelsen, Mads F.; Walsh, Timothy; Roberts, John R.; Reep, Roger L.; Hof, Patrick R.; Sherwood, Chet C.; Manger, Paul R.

2014-01-01

Although the basic morphological characteristics of neurons in the cerebellar cortex have been documented in several species, virtually nothing is known about the quantitative morphological characteristics of these neurons across different taxa. To that end, the present study investigated cerebellar neuronal morphology among eight different, large-brained mammalian species comprising a broad phylogenetic range: afrotherians (African elephant, Florida manatee), carnivores (Siberian tiger, clouded leopard), cetartiodactyls (humpback whale, giraffe) and primates (human, common chimpanzee). Specifically, several neuron types (e.g., stellate, basket, Lugaro, Golgi, and granule neurons; N = 317) of the cerebellar cortex were stained with a modified rapid Golgi technique and quantified on a computer-assisted microscopy system. There was a 64-fold variation in brain mass across species in our sample (from clouded leopard to the elephant) and a 103-fold variation in cerebellar volume. Most dendritic measures tended to increase with cerebellar volume. The cerebellar cortex in these species exhibited the trilaminate pattern common to all mammals. Morphologically, neuron types in the cerebellar cortex were generally consistent with those described in primates (Fox et al., 1967) and rodents (Palay and Chan-Palay, 1974), although there was substantial quantitative variation across species. In particular, Lugaro neurons in the elephant appeared to be disproportionately larger than those in other species. To explore potential quantitative differences in dendritic measures across species, MARSplines analyses were used to evaluate whether species could be differentiated from each other based on dendritic characteristics alone. Results of these analyses indicated that there were significant differences among all species in dendritic measures. PMID:24795574

The Compatibility Effect Of Coupling Agent On Rheological-Morphological Relationship Of Banana Fibre Reinforced Polypropylene

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chang, S. Y.; Shamsudin, Z.

The rheological properties of banana fibre reinforced polypropylene (PP/BF) composites at different composition were analysed using Shimadzu capillary rheometer. The effect of coupling agent concentration on the rheological properties was studied and followed by drawing a relationship of rheological-morphological properties of PP/BF composites. It was found that all composite system exhibits pseudoplasticity and incorporation of treated fibres consequents enhanced viscosity due to improved interfacial adhesion at fibre-matrix interface. However, it was observed that PP/BF composite with 2 wt% silane concentration does not yield further enhancement in the rheological properties when compared to that of 1 wt%. Composites with 1 wt%more » silane concentration were found to yield most promising compatibility effect with well-oriented and uniformly dispersed fibre morphology.« less

The tooth, the whole tooth and nothing but the tooth: tooth shape and ontogenetic shift dynamics in the white shark Carcharodon carcharias.

PubMed

French, G C A; Stürup, M; Rizzuto, S; van Wyk, J H; Edwards, D; Dolan, R W; Wintner, S P; Towner, A V; Hughes, W O H

2017-10-01

Results from this study of the white shark Carcharodon carcharias include measurements obtained using a novel photographic method that reveal significant differences between the sexes in the relationship between tooth cuspidity and shark total length, and a novel ontogenetic change in male tooth shape. Males exhibit broader upper first teeth and increased distal inclination of upper third teeth with increasing length, while females do not present a consistent morphological change. Substantial individual variation, with implications for pace of life syndrome, was present in males and tooth polymorphism was suggested in females. Sexual differences and individual variation may play major roles in ontogenetic changes in tooth morphology in C. carcharias, with potential implications for their foraging biology. Such individual and sexual differences should be included in studies of ontogenetic shift dynamics in other species and systems. © 2017 The Fisheries Society of the British Isles.

Noninvasive optical coherence tomography monitoring of structure and hydration changes of human corneas in different preservation media

NASA Astrophysics Data System (ADS)

Wu, Yicong; Clarke, Dominic; Mathew, Aby; Nicoud, Ian; Li, Xingde

2011-02-01

The influence of different tissue preservation (a test solution under development and a standard storage solution) on human cornea morphology, refractive index and hydration was assessed noninvasively by ultrahigh-resolution optical coherence tomography (OCT) over time. For 28 days' or 15 days' storage in the preservation media, corneas in the two media exhibited different structural changes with different onset times including epithelial desquamation, edema-induced cornea thickening and change in tissue refractive index. It was found that the variation of the group refractive index over time was only about 2%, while 25% variation of hydration was observed in the storage and subsequent return to normothermic conditions in both preservation media. The results suggest the two media involved different but correlated preservation mechanisms. This study demonstrates that the noncontact, noninvasive, and high-resolution OCT is a powerful tool for noninvasive characterization of tissue morphological changes and hydration process and for assessment of the effects of preservation media on stored tissue integrity. Engineers.

Relationships between environmental conditions and the morphological variability of planktonic testate amoeba in four neotropical floodplains.

PubMed

Arrieira, Rodrigo Leite; Schwind, Leilane Talita Fatoreto; Joko, Ciro Yoshio; Alves, Geziele Mucio; Velho, Luiz Felipe Machado; Lansac-Tôha, Fábio Amodêo

2016-10-01

Planktonic testate amoebae in floodplains exhibit a broad-range of morphological variability. The variation size is already known, but it is necessary to know how this is for morphological variables. This study aimed to identify the relationships between testate amoebae morphology and environmental factors in four neotropical floodplains. We conducted detailed morphometric analyses on 27 common species of planktonic testate amoebae from genera Arcella, Centropyxis, Cucurbitella, Suiadifflugia, Difflugia, Lesquereusia and Netzelia. We sampled subsurface water from each lake in 72 lakes in four Brazilian floodplain lakes. Our goals were to assess: (1) the range of their morphological variability (a) over space within each floodplain, and (b) among the four floodplains, and (c) over time, and (2) which environmental factors explained this variation. Mean shell height and breadth varied considerably among the different floodplain lakes, especially in the Pantanal and Amazonian floodplains. The morphological variability of testate amoeba was correlated to environmental conditions (ammonia, nitrate, phosphate, chlorophyll-a, turbidity, temperature, and depth). Thus, understanding the morphological variation of the testate amoeba species can elucidate many questions involving the ecology of these organisms. Furthermore, could help molecular studies, bioindicator role of these organisations, environmental reconstruction, among others. Copyright © 2016 Elsevier GmbH. All rights reserved.

Quantification of mammalian tumor cell state plasticity with digital holographic cytometry

NASA Astrophysics Data System (ADS)

Hejna, Miroslav; Jorapur, Aparna; Zhang, Yuntian; Song, Jun S.; Judson, Robert L.

2018-02-01

Individual cells within isogenic tumor populations can exhibit distinct cellular morphologies, behaviors, and molecular profiles. Cell state plasticity refers to the propensity of a cell to transition between these different morphologies and behaviors. Elevation of cell state plasticity is thought to contribute to critical stages in tumor evolution, including metastatic dissemination and acquisition of therapeutic resistance. However, methods for quantifying general plasticity in mammalian cells remain limited. Working with a HoloMonitor M4 digital holographic cytometry platform, we have established a machine learning-based pipeline for high accuracy and label-free classification of adherent cells. We use twenty-six morphological and optical density-derived features for label-free identification of cell state in heterogeneous cultures. The system is housed completely within a mammalian cell incubator, permitting the monitoring of changes in cell state over time. Here we present an application of our approach for studying cell state plasticity. Human melanoma cell lines of known metastatic potential were monitored in standard growth conditions. The rate of feature change was quantified for each individual cell in the populations. We observed that cells of higher metastatic potential exhibited more rapid fluctuation of cell state in homeostatic conditions. The approach we demonstrate will be advantageous for further investigations into the factors that influence cell state plasticity.

Predator-induced defenses in tadpoles confound body stoichiometry predictions of the general stress paradigm.

PubMed

Costello, David M; Michel, Matt J

2013-10-01

Predation is known to have both direct and indirect effects on nutrient cycling in terrestrial and aquatic ecosystems, and the general stress paradigm (GSP) has been promoted as a theory for describing predator-mediated indirect effects on nutrient cycling. The GSP predicts that prey exposed to predators will produce glucocorticosteroids, which have a host of physiological effects including gluconeogenesis, increased respiration, excretion of N and P, and increases in body C:N. We tested the nutrient predictions of the GSP using anuran larvae, which exhibit morphological defenses in addition to behavioral defenses for which the GSP was conceived. Genetically similar Hyla versicolor tadpoles were placed in mesocosms either in the presence or absence of a fed predator (Dytiscus verticalis), and after two weeks, tadpoles exposed to predators exhibited strong induced defenses with large, tubular bodies, larger tails, and reduced activity. Tadpole body %C and N:P increased with no change in C:N, which is contrary to expectations from the GSP. Statistical models suggested that changes in body morphology (e.g., tail muscle width) rather than behavioral defenses (i.e., reduced activity) were most likely responsible for predator-mediated differences in body stoichiometry. This study suggests that strong morphological defenses may overwhelm or counteract the nutrient predictions of the GSP.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sun, Shibin; College of Electromechanical Engineering, Qingdao University of Science and Technology, Qingdao 266061; Chang, Xueting, E-mail: xuetingchang@yahoo.cn

Cobalt-doped tungsten oxide mesocrystals with different morphologies have been successfully generated using a solvothermal method with tungsten hexachloride and cobalt chloride salts as precursors. The resulting mesocrystals were characterized by X-ray diffraction, field emission scanning electron microscopy, transmission electron microscopy, Brunauer-Emmet-Teller analysis of nitrogen sorptometer, and UV-vis diffuse reflectance spectroscopy. The photocatalytic properties of the cobalt-doped tungsten oxide mesocrystals were evaluated on the basis of their ability to degrade methyl orange in an aqueous solution under simulated sunlight irradiation. Results showed that the cobalt doping had obvious effect on the morphologies of the final products, and lenticular and blocky cobalt-dopedmore » tungsten oxide mesocrystals could be obtained with 1.0 wt.% and 2.0 wt.% cobalt doping, respectively. The cobalt-doped tungsten oxides exhibited superior photocatalytic activities to that of the undoped tungsten oxide. - Graphical abstract: Schematic illustrations of the growth of the bundled nanowires, lenticular mesocrystals, and blocky mesocrystals. Highlights: Black-Right-Pointing-Pointer Co-doped W{sub 18}O{sub 49} mesocrystals were synthesized using a solvothermal method. Black-Right-Pointing-Pointer The Co doping has obvious effect on the morphology of the final mesocrystals. Black-Right-Pointing-Pointer The Co-doped W{sub 18}O{sub 49} exhibited superior photocatalytic activity to the undoped W{sub 18}O{sub 49}.« less

Effect of reduction time on the structure and properties of porous graphene

NASA Astrophysics Data System (ADS)

Li, Guoping; Zhang, Chenhui; Zhang, Tianfu; Xia, Min; Luo, Yunjun

2017-07-01

Porous graphene with nanoscaled pores on the sheets was prepared by a carbon thermal reduction method, in which the molybdenum oxide nanoparticles generated from the thermal decomposition of molybdate were used as the etching reagent, and the pores were formed on the surface of the reduced graphene oxide under the conditions of 650 °C and a nitrogen atmosphere. The morphology of pores on the graphene sheets may affect their potential applications in various fields, especially in the enhancement of mass transfer. Previous studies have shown that the reduction temperature and the amount of metal oxide are the key factors affecting the morphology of porous graphene, but in fact the reduction time is a more important affecting factor according to the present study. The results of SEM/TEM showed that a disordered large sheet-like structure with wrinkles was obtained at 120 min in the carbon-thermal reaction. The structural integrity of the PG was further destroyed after the reaction time of 140 min, in which the edge exhibited slightly crush and significant fold. The PG exhibited a hollow rod-like structure at the reaction time of 180 min. FTIR, Raman, XRD, and XPS studies were performed to characterize the morphology of porous graphene prepared at different reduction times.

Marine phages as excellent tracers for reactive colloidal transport in porous media

NASA Astrophysics Data System (ADS)

Ghanem, Nawras; Chatzinotas, Antonis; Harms, Hauke; Wick, Lukas Y.

2016-04-01

Question: Here we evaluate marine phages as specific markers of hydrological flow and reactive transport of colloidal particles in the Earth's critical zone (CZ). Marine phages and their bacterial hosts are naturally absent in the CZ, and can be detected with extremely high sensitivity. In the framework of the DFG Collaborative Research Center AquaDiva, we asked the following questions: (1) Are marine phages useful specific markers of hydrological flow and reactive transport in porous media? and (2) Which phage properties are relevant drivers for the transport of marine phages in porous media? Methods: Seven marine phages from different families (as well two commonly used terrestrial phages) were selected based on their morphology, size and physico-chemical surface properties (surface charge and hydrophobicity). Phage properties were assessed by electron microscopy, dynamic light scattering and water contact angle analysis (CA). Sand-filled laboratory percolation columns were used to study transport. The breakthrough curves of the phages were analyzed using the clean bed filtration theory and the XDLVO theory of colloid stability, respectively. Phages were quantified by a modified high- throughput plaque assay and a culture-independent particle counting method approach. Results: Our data show that most marine tested phages exhibited highly variable transport rates and deposition efficiency, yet generally high colloidal stability and viability. We find that size, morphology and hydrophobicity are key factors shaping the transport efficiency of phages. Differing deposition efficiencies of the phages were also supported by calculated XDLVO interaction energy profile. Conclusion: Marine phages have a high potential for the use as sensitive tracers in terrestrial habitats with their surface properties playing a crucial role for their transport. Marine phages however, exhibit differences in their deposition efficiency depending on their morphology, hydrophobicity and availability.

Controllable synthesis of Ln3+ (Ln = Tb, Eu) doped zinc phosphate nano-/micro-structured materials: phase, morphology and luminescence properties

NASA Astrophysics Data System (ADS)

Yue, Dan; Lu, Wei; Li, Chunyang; Zhang, Xinlei; Liu, Chunxia; Wang, Zhenling

2014-01-01

Ln3+ (Ln = Tb, Eu) doped zinc phosphate tetrahydrate (ZPT:Ln3+) and ammonium zinc phosphate (AZP:Ln3+) nano-/micro-structured materials were synthesized in aqueous solution without the addition of any structure-directing agent. The phase structures, morphologies and luminescence properties of the as-synthesized samples were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), transmission electron microscopy (TEM), photoluminescence (PL) spectroscopy and lifetime. These investigations indicate that different phosphate sources MnH(3-n)PO4 (M = NH4+ or Na+, n = 1, 2, 3) can lead to the altering of morphology from nanosheet to microflower, but have no significant effect on the phase structure of the samples. The microlump, nanosheet, and microflower (constructed by the primary microlumps or nanosheets) of orthorhombic ZPT:Ln3+ could be selectively prepared by adjusting the pH value from 3.5 to 7.0. A mixture of orthorhombic ZPT:Ln3+ and monoclinic AZP:Ln3+ with a microflower morphology was obtained when the pH value was adjusted to 8.0. Monoclinic AZP:Ln3+ microplate, microcube and nanoparticle morphologies were obtained at pH values of 8.5, 9.0 and 11.0 respectively. The phase transformation and growth mechanism of the diverse morphologies were proposed, and ZPT:Ln3+ (Ln3+ = Eu or Tb) samples exhibit red or green emission under the excitation of UV light.Ln3+ (Ln = Tb, Eu) doped zinc phosphate tetrahydrate (ZPT:Ln3+) and ammonium zinc phosphate (AZP:Ln3+) nano-/micro-structured materials were synthesized in aqueous solution without the addition of any structure-directing agent. The phase structures, morphologies and luminescence properties of the as-synthesized samples were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), transmission electron microscopy (TEM), photoluminescence (PL) spectroscopy and lifetime. These investigations indicate that different phosphate sources MnH(3-n)PO4 (M = NH4+ or Na+, n = 1, 2, 3) can lead to the altering of morphology from nanosheet to microflower, but have no significant effect on the phase structure of the samples. The microlump, nanosheet, and microflower (constructed by the primary microlumps or nanosheets) of orthorhombic ZPT:Ln3+ could be selectively prepared by adjusting the pH value from 3.5 to 7.0. A mixture of orthorhombic ZPT:Ln3+ and monoclinic AZP:Ln3+ with a microflower morphology was obtained when the pH value was adjusted to 8.0. Monoclinic AZP:Ln3+ microplate, microcube and nanoparticle morphologies were obtained at pH values of 8.5, 9.0 and 11.0 respectively. The phase transformation and growth mechanism of the diverse morphologies were proposed, and ZPT:Ln3+ (Ln3+ = Eu or Tb) samples exhibit red or green emission under the excitation of UV light. Electronic supplementary information (ESI) available: Additional XRD patterns, EDX, SEM and TEM images, dependence of the average lifetimes on the different doping concentrations of Eu3+ and Tb3+. See DOI: 10.1039/c3nr03749e

Molecular evolution of calcification genes in morphologically similar but phylogenetically unrelated scleractinian corals.

PubMed

Wirshing, Herman H; Baker, Andrew C

2014-08-01

Molecular phylogenies of scleractinian corals often fail to agree with traditional phylogenies derived from morphological characters. These discrepancies are generally attributed to non-homologous or morphologically plastic characters used in taxonomic descriptions. Consequently, morphological convergence of coral skeletons among phylogenetically unrelated groups is considered to be the major evolutionary process confounding molecular and morphological hypotheses. A strategy that may help identify cases of convergence and/or diversification in coral morphology is to compare phylogenies of existing "neutral" genetic markers used to estimate genealogic phylogenetic history with phylogenies generated from non-neutral genes involved in calcification (biomineralization). We tested the hypothesis that differences among calcification gene phylogenies with respect to the "neutral" trees may represent convergent or divergent functional strategies among calcification gene proteins that may correlate to aspects of coral skeletal morphology. Partial sequences of two nuclear genes previously determined to be involved in the calcification process in corals, "Cnidaria-III" membrane-bound/secreted α-carbonic anhydrase (CIII-MBSα-CA) and bone morphogenic protein (BMP) 2/4, were PCR-amplified, cloned and sequenced from 31 scleractinian coral species in 26 genera and 9 families. For comparison, "neutral" gene phylogenies were generated from sequences from two protein-coding "non-calcification" genes, one nuclear (β-tubulin) and one mitochondrial (cytochrome b), from the same individuals. Cloned CIII-MBSα-CA sequences were found to be non-neutral, and phylogenetic analyses revealed CIII-MBSα-CAs to exhibit a complex evolutionary history with clones distributed between at least 2 putative gene copies. However, for several coral taxa only one gene copy was recovered. With CIII-MBSα-CA, several recovered clades grouped taxa that differed from the "non-calcification" loci. In some cases, these taxa shared aspects of their skeletal morphology (i.e., convergence or diversification relative to the "non-calcification" loci), but in other cases they did not. For example, the "non-calcification" loci recovered Atlantic and Pacific mussids as separate evolutionary lineages, whereas with CIII-MBSα-CA, clones of two species of Atlantic mussids (Isophyllia sinuosa and Mycetophyllia sp.) and two species of Pacific mussids (Acanthastrea echinata and Lobophyllia hemprichii) were united in a distinct clade (except for one individual of Mycetophyllia). However, this clade also contained other taxa which were not unambiguously correlated with morphological features. BMP2/4 also contained clones that likely represent different gene copies. However, many of the sequences showed no significant deviation from neutrality, and reconstructed phylogenies were similar to the "non-calcification" tree topologies with a few exceptions. Although individual calcification genes are unlikely to precisely explain the diverse morphological features exhibited by scleractinian corals, this study demonstrates an approach for identifying cases where morphological taxonomy may have been misled by convergent and/or divergent molecular evolutionary processes in corals. Studies such as this may help illuminate our understanding of the likely complex evolution of genes involved in the calcification process, and enhance our knowledge of the natural history and biodiversity within this central ecological group. Published by Elsevier Inc.

Morphological driven photocatalytic activity of ZnO nanostructures

NASA Astrophysics Data System (ADS)

Abbas, Khaldoon N.; Bidin, Noriah

2017-02-01

Using a simple combination of pulse laser ablation in liquid and hydrothermal (PLAL-H) approaches, we control the morphology of ZnO nanostructures (ZNSs) to determine the feasibility of their photocatalytic efficacy. These ZNSs are deposited on Si (100) substrates and two different morphologies are achieved. In this synergistic approach, PLAL synthesized NSs are used as a nutrient solution with different pH for further hydrothermal treatment at 110 °C under varying growth time (5, 30 and 60 min). Surface morphology, structure, composition, and optical characteristics of the prepared ZNSs are determined using FESEM, XRD, FTIR and Photoluminescence (PL) and UV-vis absorption measurements. The morphology revealed remarkable transformation from nanorods (NRs)/nanoflowers (NFs) (at pH 7.6) to nanoparticles (NPs)-like (at pH 10.5) structure. XRD patterns showed better polycrystallinity for NPs with enlarged band gap than NR/NF-like structures. Both PL and UV-vis spectral analysis of ZNPs exhibited higher surface area and deep level defects density dependent morphology, where the nutrient pH and growth time variation are found to play a significant role towards structural evolution. Furthermore, the photocatalytic activities of, such ZNSs are evaluated via sunlight driven photo-degradation of methylene blue (MB) dye. The photocatalytic efficiency of ZNPs is demonstrated to be much superior (97.4%) than ZNRs/ZNFs-like morphology (86%). Such enhanced photocatalytic activities of as-synthesized ZNPs is attributed to the synergism of the improved surface area and defects density, which is useful for promoting the adsorption of the MB dye and suppressed surface recombination of photo-generated charge carriers.

Self-assembled flower-like antimony trioxide microstructures with high infrared reflectance performance

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ge, Shengsong, E-mail: geshengsong@126.com; Yang, Xiaokun; Shao, Qian

A simple hydrothermal process was adopted to self-assembly prepare high infrared reflective antimony trioxide with three-dimensional flower-like microstructures. The morphologies of antimony trioxide microstructures were characterized by X-ray diffractometry (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and high resolution transmission electron microscopy (HRTEM) respectively. It is also found that experimental parameters, such as NaOH concentration, surfactant concentration and volume ratio of ethanol–water played crucial roles in controlling the morphologies of Sb{sub 2}O{sub 3} microstructures. A possible growth mechanism of flower-like Sb{sub 2}O{sub 3} microstructure was proposed based on the experimental data. UV–vis–NIR spectra verified that the near infraredmore » reflectivity of the obtained flower-like microstructures could averagely achieve as 92% with maximum reflectivity of 98%, obviously higher than that of other different morphologies of antimony trioxide microstructures. It is expected that the flower-like Sb{sub 2}O{sub 3} nanostructures have some applications in optical materials and heat insulation coatings. - Graphical abstract: Flower-like Sb{sub 2}O{sub 3} microstructures that composed of nanosheets with thickness of ca. 100 nm exhibit high reflectivity under UV–vis–NIR spectra. Highlights: ► Uniform flower-like microstructures were synthesized via simple hydrothermal reaction. ► The flower-like Sb{sub 2}O{sub 3} microstructures exhibited higher reflectivity than other morphologies under the UV–vis–NIR light. ► Influencing parameters on the Sb{sub 2}O{sub 3} morphologies have been discussed in detail. ► Possible mechanism leading to flower-like microstructures was proposed.« less

Impact of oxidative stress defense on bacterial survival and morphological change in Campylobacter jejuni under aerobic conditions.

PubMed

Oh, Euna; McMullen, Lynn; Jeon, Byeonghwa

2015-01-01

Campylobacter jejuni, a microaerophilic foodborne pathogen, inescapably faces high oxygen tension during its transmission to humans. Thus, the ability of C. jejuni to survive under oxygen-rich conditions may significantly impact C. jejuni viability in food and food safety as well. In this study, we investigated the impact of oxidative stress resistance on the survival of C. jejuni under aerobic conditions by examining three mutants defective in key antioxidant genes, including ahpC, katA, and sodB. All the three mutants exhibited growth reduction under aerobic conditions compared to the wild-type (WT), and the ahpC mutant showed the most significant growth defect. The CFU reduction in the mutants was recovered to the WT level by complementation. Higher levels of reactive oxygen species were accumulated in C. jejuni under aerobic conditions than microaerobic conditions, and supplementation of culture media with an antioxidant recovered the growth of C. jejuni. The levels of lipid peroxidation and protein oxidation were significantly increased in the mutants compared to WT. Additionally, the mutants exhibited different morphological changes under aerobic conditions. The ahpC and katA mutants developed coccoid morphology by aeration, whereas the sodB mutant established elongated cellular morphology. Compared to microaerobic conditions, interestingly, aerobic culture conditions substantially induced the formation of coccoidal cells, and antioxidant treatment reduced the emergence of coccoid forms under aerobic conditions. The ATP concentrations and PMA-qPCR analysis supported that oxidative stress is a factor that induces the development of a viable-but-non-culturable state in C. jejuni. The findings in this study clearly demonstrated that oxidative stress resistance plays an important role in the survival and morphological changes of C. jejuni under aerobic conditions.

Hip morphology in elite golfers: asymmetry between lead and trail hips.

PubMed

Dickenson, Edward; O'Connor, Philip; Robinson, Philip; Campbell, Robert; Ahmed, Imran; Fernandez, Miguel; Hawkes, Roger; Charles, Hutchinson; Griffin, Damian

2016-09-01

During a golf swing, the lead hip (left hip in a right-handed player) rotates rapidly from external to internal rotation, while the opposite occurs in the trail hip. This study assessed the morphology and pathology of golfers' hips comparing lead and trail hips. A cohort of elite golfers were invited to undergo MRI of their hips. Hip morphology was evaluated by measuring acetabular depth (pincer shape=negative measure), femoral neck antetorsion (retrotorsion=negative measure) and α angles (cam morphology defined as α angle >55° anteriorly) around the axis of the femoral neck. Consultant musculoskeletal radiologists determined the presence of intra-articular pathology. 55 players (mean age 28 years, 52 left hip lead) underwent MRI. No player had pincer morphology, 2 (3.6%) had femoral retrotorsion and 9 (16%) had cam morphology. 7 trail hips and 2 lead hips had cam morphology (p=0.026). Lead hip femoral neck antetorsion was 16.7° compared with 13.0° in the trail hip (p<0.001). The α angles around the femoral neck were significantly lower in the lead compared with trail hips (p<0.001), with the greatest difference noted in the anterosuperior portion of the head neck junction; 53° vs 58° (p<0.001) and 43° vs 47° (p<0.001). 37% of trail and 16% of lead hips (p=0.038) had labral tears. Golfers' lead and trail hips have different morphology. This is the first time side-to-side asymmetry of cam prevalence has been reported. The trail hip exhibited a higher prevalence of labral tears. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

Is Supramolecular Filament Chirality the Underlying Cause of Major Morphology Differences in Amyloid Fibrils?

PubMed Central

2015-01-01

The unique enhanced sensitivity of vibrational circular dichroism (VCD) to the formation and development of amyloid fibrils in solution is extended to four additional fibril-forming proteins or peptides where it is shown that the sign of the fibril VCD pattern correlates with the sense of supramolecular filament chirality and, without exception, to the dominant fibril morphology as observed in AFM or SEM images. Previously for insulin, it has been demonstrated that the sign of the VCD band pattern from filament chirality can be controlled by adjusting the pH of the incubating solution, above pH 2 for “normal” left-hand-helical filaments and below pH 2 for “reversed” right-hand-helical filaments. From AFM or SEM images, left-helical filaments form multifilament braids of left-twisted fibrils while the right-helical filaments form parallel filament rows of fibrils with a flat tape-like morphology, the two major classes of fibril morphology that from deep UV resonance Raman scattering exhibit the same cross-β-core secondary structure. Here we investigate whether fibril supramolecular chirality is the underlying cause of the major morphology differences in all amyloid fibrils by showing that the morphology (twisted versus flat) of fibrils of lysozyme, apo-α-lactalbumin, HET-s (218–289) prion, and a short polypeptide fragment of transthyretin, TTR (105–115), directly correlates to their supramolecular chirality as revealed by VCD. The result is strong evidence that the chiral supramolecular organization of filaments is the principal underlying cause of the morphological heterogeneity of amyloid fibrils. Because fibril morphology is linked to cell toxicity, the chirality of amyloid aggregates should be explored in the widely used in vitro models of amyloid-associated diseases. PMID:24484302

Is supramolecular filament chirality the underlying cause of major morphology differences in amyloid fibrils?

PubMed

Kurouski, Dmitry; Lu, Xuefang; Popova, Ludmila; Wan, William; Shanmugasundaram, Maruda; Stubbs, Gerald; Dukor, Rina K; Lednev, Igor K; Nafie, Laurence A

2014-02-12

The unique enhanced sensitivity of vibrational circular dichroism (VCD) to the formation and development of amyloid fibrils in solution is extended to four additional fibril-forming proteins or peptides where it is shown that the sign of the fibril VCD pattern correlates with the sense of supramolecular filament chirality and, without exception, to the dominant fibril morphology as observed in AFM or SEM images. Previously for insulin, it has been demonstrated that the sign of the VCD band pattern from filament chirality can be controlled by adjusting the pH of the incubating solution, above pH 2 for "normal" left-hand-helical filaments and below pH 2 for "reversed" right-hand-helical filaments. From AFM or SEM images, left-helical filaments form multifilament braids of left-twisted fibrils while the right-helical filaments form parallel filament rows of fibrils with a flat tape-like morphology, the two major classes of fibril morphology that from deep UV resonance Raman scattering exhibit the same cross-β-core secondary structure. Here we investigate whether fibril supramolecular chirality is the underlying cause of the major morphology differences in all amyloid fibrils by showing that the morphology (twisted versus flat) of fibrils of lysozyme, apo-α-lactalbumin, HET-s (218-289) prion, and a short polypeptide fragment of transthyretin, TTR (105-115), directly correlates to their supramolecular chirality as revealed by VCD. The result is strong evidence that the chiral supramolecular organization of filaments is the principal underlying cause of the morphological heterogeneity of amyloid fibrils. Because fibril morphology is linked to cell toxicity, the chirality of amyloid aggregates should be explored in the widely used in vitro models of amyloid-associated diseases.

Researching into the cellular shape, volume and elasticity of mesenchymal stem cells, osteoblasts and osteosarcoma cells by atomic force microscopy

PubMed Central

Docheva, Denitsa; Padula, Daniela; Popov, Cvetan; Mutschler, Wolf; Clausen-Schaumann, Hauke; Schieker, Matthias

2008-01-01

Abstract Within the bone lie several different cell types, including osteoblasts (OBs) and mesenchymal stem cells (MSCs). The MSCs are ideal targets for regenerative medicine of bone due to their differentiation potential towards OBs. Human MSCs exhibit two distinct morphologies: rapidly self-renewing cells (RS) and flat cells (FC) with very low proliferation rates. Another cell type found in pathological bone conditions is osteosarcoma. In this study, we compared the topographic and morphometric features of RS and FC cells, human OBs and MG63 osteosarcoma cells by atomic force microscopy (AFM). The results demonstrated clear differences: FC and hOB cells showed similar ruffled topography, whereas RS and MG63 cells exhibited smoother surfaces. Furthermore, we investigated how selected substrates influence cell morphometry. We found that RS and MG63 cells were flatter on fibrous substrates such as polystyrene and collagen I, but much more rounded on glass, the smoothest surface. In contrast, cells with large area, namely FC and hOB cells, did not exhibit pronounced changes in flatness with regards to the different substrates. They were, however, remarkably flatter in comparison to RS and MG63 cells. We could explain the differences in flatness by the extent of adhesion. Indeed, FC and hOB cells showed much higher content of focal adhesions. Finally, we used the AFM to determine the cellular Young's modulus. RS, FC and hOB cells showed comparable stiffness on the three different substrates, while MG63 cells demonstrated the unique feature of increased elasticity on collagen I. In summary, our results show, for the first time, a direct comparison between the morphometric and biophysical features of different human cell types derived from normal and pathological bone. Our study manifests the opinion that along with RNA, proteomic and functional research, morphological and biomechanical characterization of cells also reveals novel cell features and interrelationships. PMID:18419596

Strings on a Violin: Location Dependence of Frequency Tuning in Active Dendrites.

PubMed

Das, Anindita; Rathour, Rahul K; Narayanan, Rishikesh

2017-01-01

Strings on a violin are tuned to generate distinct sound frequencies in a manner that is firmly dependent on finger location along the fingerboard. Sound frequencies emerging from different violins could be very different based on their architecture, the nature of strings and their tuning. Analogously, active neuronal dendrites, dendrites endowed with active channel conductances, are tuned to distinct input frequencies in a manner that is dependent on the dendritic location of the synaptic inputs. Further, disparate channel expression profiles and differences in morphological characteristics could result in dendrites on different neurons of the same subtype tuned to distinct frequency ranges. Alternately, similar location-dependence along dendritic structures could be achieved through disparate combinations of channel profiles and morphological characteristics, leading to degeneracy in active dendritic spectral tuning. Akin to strings on a violin being tuned to different frequencies than those on a viola or a cello, different neuronal subtypes exhibit distinct channel profiles and disparate morphological characteristics endowing each neuronal subtype with unique location-dependent frequency selectivity. Finally, similar to the tunability of musical instruments to elicit distinct location-dependent sounds, neuronal frequency selectivity and its location-dependence are tunable through activity-dependent plasticity of ion channels and morphology. In this morceau, we explore the origins of neuronal frequency selectivity, and survey the literature on the mechanisms behind the emergence of location-dependence in distinct forms of frequency tuning. As a coda to this composition, we present some future directions for this exciting convergence of biophysical mechanisms that endow a neuron with frequency multiplexing capabilities.

Selection of reference genes for quantitative real-time RT-PCR assays in different morphological forms of dimorphic zygomycetous fungus Benjaminiella poitrasii.

PubMed

Pathan, Ejaj K; Ghormade, Vandana; Deshpande, Mukund V

2017-01-01

Benjaminiella poitrasii, a dimorphic non-pathogenic zygomycetous fungus, exhibits a morphological yeast (Y) to hypha (H) reversible transition in the vegetative phase, sporangiospores (S) in the asexual phase and zygospores (Z) in the sexual phase. To study the gene expression across these diverse morphological forms, suitable reference genes are required. In the present study, 13 genes viz. ACT, 18S rRNA, eEF1α, eEF-Tu,eIF-1A, Tub-α, Tub-b, Ubc, GAPDH, Try, WS-21, NADGDH and NADPGDH were evaluated for their potential as a reference, particularly for studying gene expression during the Y-H reversible transition and also for other asexual and sexual life stages of B. poitrasii. Analysis of RT-qPCR data using geNorm, normFinder and BestKeeper software revealed that genes such as Ubc, 18S rRNA and WS-21 were expressed at constant levels in each given subset of RNA samples from all the morphological phases of B. poitrasii. Therefore, these reference genes can be used to elucidate the role of morpho-genes in B. poitrasii. Further, use of the two most stably expressed genes (Ubc and WS-21) to normalize the expression of the ornithine decarboxylase gene (Bpodc) in different morphological forms of B. poitrasii, generated more reliable results, indicating that our selection of reference genes was appropriate.

Hippocampus-based contextual memory alters the morphological characteristics of astrocytes in the dentate gyrus.

PubMed

Choi, Moonseok; Ahn, Sangzin; Yang, Eun-Jeong; Kim, Hyunju; Chong, Young Hae; Kim, Hye-Sun

2016-07-26

Astrocytes have been reported to exist in two states, the resting and the reactive states. Morphological changes in the reactive state of astrocytes include an increase in thickness and number of processes, and an increase in the size of the cell body. Molecular changes also occur, such as an increase in the expression of glial fibrillary acidic protein (GFAP). However, the morphological and molecular changes during the process of learning and memory have not been elucidated. In the current study, we subjected Fvb/n mice to contextual fear conditioning, and checked for morphological and molecular changes in astrocytes. 1 h after fear conditioning, type II and type III astrocytes exhibited a unique status with an increased number of processes and decreased GFAP expression which differed from the typical resting or reactive state. In addition, the protein level of excitatory excitatory amino acid transporter 2 (EAAT2) was increased 1 h to 24 h after contextual fear conditioning while EAAT1 did not show any alterations. Connexin 43 (Cx43) protein was found to be increased at 24 h after fear conditioning. These data suggest that hippocampus-based contextual memory process induces changes in the status of astrocytes towards a novel status different from typical resting or reactive states. These morphological and molecular changes may be in line with functional changes.

Morphological Processing of Ultraviolet Emissions of Electrical Corona Discharge for Analysis and Diagnostic Use

NASA Technical Reports Server (NTRS)

Schubert, Matthew R.; Moore, Andrew J.

2015-01-01

Electron cascades from electrical discharge produce secondary emissions from atmospheric plasma in the ultraviolet band. For a single point of discharge, these emissions exhibit a stereotypical discharge morphology, with latent information about the discharge location. Morphological processing can uncover the location and therefore can have diagnostic utility.

Morphological processing of ultraviolet emissions of electrical corona discharge for analysis and diagnostic use.

PubMed

Schubert, Matthew; Moore, Andrew J

2016-03-01

Electron cascades from electrical discharge produce secondary emissions from atmospheric plasma in the ultraviolet band. For a single point of discharge, these emissions exhibit a stereotypical discharge morphology, with latent information about the discharge location. Morphological processing can uncover the location and therefore have diagnostic utility.

Masticatory form and function in the African apes.

PubMed

Taylor, Andrea B

2002-02-01

This study examines variability in masticatory morphology as a function of dietary preference among the African apes. The African apes differ in the degree to which they consume leaves and other fibrous vegetation. Gorilla gorilla beringei, the eastern mountain gorilla, consumes the most restricted diet comprised of mechanically resistant foods such as leaves, pith, bark, and bamboo. Gorilla gorilla gorilla, the western lowland gorilla subspecies, consumes leaves and other terrestrial herbaceous vegetation (THV) but also consumes a fair amount of ripe, fleshy fruit. In contrast to gorillas, chimpanzees are frugivores and rely on vegetation primarily as fallback foods. However, there has been a long-standing debate regarding whether Pan paniscus, the pygmy chimpanzee (or bonobo), consumes greater quantities of THV as compared to Pan troglodytes, the common chimpanzee. Because consumption of resistant foods involves more daily chewing cycles and may require larger average bite force, the mechanical demands placed on the masticatory system are expected to be greater in folivores as compared to primates that consume large quantities of fleshy fruit. Therefore, more folivorous taxa are predicted to exhibit features that improve load-resistance capabilities and increase force production. To test this hypothesis, jaw and skull dimensions were compared in ontogenetic series of G. g. beringei, G. g. gorilla, P. t. troglodytes, and P. paniscus. Controlling for the influence of allometry, results show that compared to both chimpanzees and bonobos, gorillas exhibit some features of the jaw complex that are suggestive of improved masticatory efficiency. For example, compared to all other taxa, G. g. beringei has a significantly wider mandibular corpus and symphysis, larger area for the masseter muscle, higher mandibular ramus, and higher mandibular condyle relative to the occlusal plane of the mandible. However, the significantly wider mandibular symphysis may be an architectural response to increasing symphyseal curvature with interspecific increase in size. Moreover, Gorilla and Pan do not vary consistently in all features, and some differences run counter to predictions based on dietary variation. Thus, the morphological responses are not entirely consonant with predictions based on hypothesized loading regimes. Finally, despite morphological differences between bonobos and chimpanzees, there is no systematic pattern of differentiation that can be clearly linked to differences in diet. Results indicate that while some features may be linked to differences in diet among the African apes, diet alone cannot account for the patterns of morphological variation demonstrated in this study. Allometric constraints and dental development also appear to play a role in morphological differentiation among the African apes. Copyright 2002 Wiley-Liss, Inc.

Use of Advanced Characterization Techniques to Study Structural and Compositional Transitions Across Solid State Interfaces (Preprint)

DTIC Science & Technology

2011-07-01

and ω phases, is shown in Figure 4a. While these α precipitates exhibit a lenticular morphology, the ω precipitates exhibit a more ellipsoidal...morphology. Subsequent isothermal annealing at 400°C for 2 hours resulted in two changes, namely, growth and coarsening of the lenticular α...contrast) imaging studies on the nanometer scale lenticular α precipitates and their interface with the surrounding β matrix were carried out in the

Bone indicators of grasping hands in lizards

PubMed Central

2016-01-01

Grasping is one of a few adaptive mechanisms that, in conjunction with clinging, hooking, arm swinging, adhering, and flying, allowed for incursion into the arboreal eco-space. Little research has been done that addresses grasping as an enhanced manual ability in non-mammalian tetrapods, with the exception of studies comparing the anatomy of muscle and tendon structure. Previous studies showed that grasping abilities allow exploitation for narrow branch habitats and that this adaptation has clear osteological consequences. The objective of this work is to ascertain the existence of morphometric descriptors in the hand skeleton of lizards related to grasping functionality. A morphological matrix was constructed using 51 morphometric variables in 278 specimens, from 24 genera and 13 families of Squamata. To reduce the dimensions of the dataset and to organize the original variables into a simpler system, three PCAs (Principal Component Analyses) were performed using the subsets of (1) carpal variables, (2) metacarpal variables, and (3) phalanges variables. The variables that demonstrated the most significant contributions to the construction of the PCA synthetic variables were then used in subsequent analyses. To explore which morphological variables better explain the variations in the functional setting, we ran Generalized Linear Models for the three different sets. This method allows us to model the morphology that enables a particular functional trait. Grasping was considered the only response variable, taking the value of 0 or 1, while the original variables retained by the PCAs were considered predictor variables. Our analyses yielded six variables associated with grasping abilities: two belong to the carpal bones, two belong to the metacarpals and two belong to the phalanges. Grasping in lizards can be performed with hands exhibiting at least two different independently originated combinations of bones. The first is a combination of a highly elongated centrale bone, reduced palmar sesamoid, divergence angles above 90°, and slender metacarpal V and phalanges, such as exhibited by Anolis sp. and Tropidurus sp. The second includes an elongated centrale bone, lack of a palmar sesamoid, divergence angles above 90°, and narrow metacarpal V and phalanges, as exhibited by geckos. Our data suggest that the morphological distinction between graspers and non-graspers is demonstrating the existence of ranges along the morphological continuum within which a new ability is generated. Our results support the hypothesis of the nested origin of grasping abilities within arboreality. Thus, the manifestation of grasping abilities as a response to locomotive selective pressure in the context of narrow-branch eco-spaces could also enable other grasping-dependent biological roles, such as prey handling. PMID:27168987

Various fates of neuronal progenitor cells observed on several different chemical functional groups

NASA Astrophysics Data System (ADS)

Liu, Xi; Wang, Ying; He, Jin; Wang, Xiu-Mei; Cui, Fu-Zhai; Xu, Quan-Yuan

2011-12-01

Neuronal progenitor cells cultured on gold-coated glass surfaces modified by different chemical functional groups, including hydroxyl (-OH), carboxyl (-COOH), amino (-NH2), bromo (-Br), mercapto (-SH), - Phenyl and methyl (-CH3), were studied here to investigate the influence of surface chemistry on the cells' adhesion, morphology, proliferation and functional gene expression. Focal adhesion staining indicated in the initial culture stage cells exhibited morphological changes in response to different chemical functional groups. Cells cultured on -NH2 grafted surface displayed focal adhesion plaque and flattened morphology and had the largest contact area. However, their counter parts on -CH3 grafted surface displayed no focal adhesion and rounded morphology and had the smallest contact area. After 6 days culture, the proliferation trend was as follows: -NH2 > -SH> -COOH> - Phenyl > - Br > -OH> -CH3. To determine the neural functional properties of the cells affected by surface chemistry, the expression of glutamate decarboxylase (GAD67), nerve growth factor (NGF) and brainderived neurotrophic factor (BDNF) were characterized. An increase of GAD67 expression was observed on -NH2, -COOH and -SH grafted surfaces, while no increase in NGF and BDNF expression was observed on any chemical surfaces. These results highlight the importance of surface chemistry in the fate determination of neuronal progenitor cells, and suggest that surface chemistry must be considered in the design of biomaterials for neural tissue engineering.

Foliar anatomy and microscopy of six Brazilian species of Baccharis (Asteraceae).

PubMed

Budel, J M; Raman, V; Monteiro, L M; Almeida, V P; Bobek, V B; Heiden, G; Takeda, I J M; Khan, I A

2018-04-27

We report for the first time the presence of cluster crystals of calcium oxalate within the glandular trichomes and oil bodies in the mesophyll for Baccharis species. Moreover, the comparative leaf anatomy and micro-morphology of six species of Baccharis, namely B. illinita, B. microdonta, B. pauciflosculosa, B. punctulata, B. reticularioides, and B. sphenophylla is investigated by light and scanning electron microscopy. The studied species exhibited differences in their leaf anatomical features such as the morphology of the cuticle, type and occurrence of the stomata, presence or absence of glandular trichomes, shape of the flagelliform trichomes, and the arrangement of the mesophyll tissues. These differences can be helpful in the species identification and classification and could represent informative characters for the reconstruction of the evolution of the genus. © 2018 Wiley Periodicals, Inc.

Effects of the morphology of CIPs on microwave absorption behaviors

NASA Astrophysics Data System (ADS)

Woo, Soobin; Yoo, Chan-Sei; Kim, Hwijun; Lee, Mijung; Quevedo-Lopez, Manuel; Choi, Hyunjoo

2017-11-01

Electromagnetic (EM) wave absorption properties are affected by the thickness and surface area of absorbing materials. In this study, a facile ball-milling process was introduced to effectively reduce the diameter and increase the aspect ratio of carbonyl iron powder (CIP), which is one of the most commercially available EM-absorbing materials. The size, aspect ratio, and consequent surface area of CIP were manipulated by controlling the milling parameters to investigate their effects on EM absorption properties. The results indicated that ball-milled CIPs exhibited better EM wave absorption ability when compared with that of pristine CIPs. However, significant differences in minimum reflection loss values were not observed between CIPs with different morphologies and similar specific surface areas. Hence, both fine and flaky CIPs were considered as beneficial for EM wave absorption.[Figure not available: see fulltext.

Surfaces wettability and morphology modulation in a fluorene derivative self-assembly system

NASA Astrophysics Data System (ADS)

Cao, Xinhua; Gao, Aiping; Zhao, Na; Yuan, Fangyuan; Liu, Chenxi; Li, Ruru

2016-04-01

A new organogelator based on fluorene derivative (gelator 1) was designed and synthesized. Organogels could be obtained via the self-assembly of the derivative in acetone, toluene, ethyl acetate, hexane, DMSO and petroleum ether. The self-assembly process was thoroughly characterized using field-emission scanning electron microscopy (FESEM), X-ray diffraction (XRD), UV-vis, FT-IR and the contact angle. Surfaces with different morphologies and wetting properties were formed via the self-assembly of gelator 1 in the six different solvents. Interestingly, a superhydrophobic surface with a contact angle of 150° was obtained from organogel 1 in DMSO and exhibited the lotus-effect. The sliding angle necessary for a water droplet to move on the glass was only 15°. Hydrogen bonding and van der Waals forces were attributed as the main driving forces for gel formation.

Fabrication of low reflective nanopore-type black Si layer using one-step Ni-assisted chemical etching for Si solar cell application

NASA Astrophysics Data System (ADS)

Takaloo, AshkanVakilipour; Kolahdouz, Mohammadreza; Poursafar, Jafar; Es, Firat; Turan, Rasit; Ki-Joo, Seung

2018-03-01

Nanotextured Si fabricated through metal-assisted chemical etching (MACE) technique exhibits a promising potential for producing antireflective layer for photovoltaic (PV) application. In this study, a novel single-step nickel (Ni) assisted etching technique was applied to produce an antireflective, nonporous Si (black Si) in an aqueous solution containing hydrofluoric acid (HF), hydrogen peroxide (H2O2) and NiSO4 at 40 °C. Field emission scanning electron microscope was used to characterize different morphologies of the textured Si. Optical reflection measurements of samples were carried out to compare the reflectivity of different morphologies. Results indicated that vertical as well as horizontal pores with nanosized diameters were bored in the Si wafer after 1 h treatment in the etching solution containing different molar ratios of H2O2 to HF. Increasing H2O2 concentration in electrochemical etching solution had a considerable influence on the morphology due to higher injection of positive charges from Ni atoms onto the Si surface. Optimized concentration of H2O2 led to formation of an antireflective layer with 2.1% reflectance of incident light.

Sex-based differences in the adaptive value of social behavior contrasted against morphology and environment.

PubMed

Vander Wal, E; Festa-Bianchet, M; Réale, D; Coltman, D W; Pelletier, F

2015-03-01

The adaptive nature of sociality has long been a central question in ecology and evolution. However, the relative importance of social behavior for fitness, compared to morphology and environment, remains largely unknown. We assessed the importance of sociality for fitness (lamb production and survival) in a population of mark6d bighorn sheep (Ovis canadensis) over 16 years (n = 1022 sheep-years). We constructed social networks from observations (n = 38,350) of group membership (n = 3150 groups). We then tested whether consistent individual differences in social behavior (centrality) exist and evaluated their relative importance compared to factors known to affect fitness: mass, age, parental effects, and population density. Sheep exhibited consistent individual differences in social centrality. Controlling for maternal carryover effects and age, the positive effect of centrality in a social network on adult female lamb production and survival was equal or greater than the effect of body mass or population density. Social centrality had less effect on male survival and no effect on adult male lamb production or lamb survival. Through its effect on lamb production and survival, sociality in fission-fusion animal societies may ultimately influence population dynamics equally or more than morphological or environmental effects.

Calcite precipitates in Slovenian bottled waters.

PubMed

Stanič, Tamara Ferjan; Miler, Miloš; Brenčič, Mihael; Gosar, Mateja

2017-06-01

Storage of bottled waters in varying ambient conditions affects its characteristics. Different storage conditions cause changes in the initial chemical composition of bottled water which lead to the occurrence of precipitates with various morphologies. In order to assess the relationship between water composition, storage conditions and precipitate morphology, a study of four brands of Slovenian bottled water stored in PET bottles was carried out. Chemical analyses of the main ions and measurements of the physical properties of water samples were performed before and after storage of water samples at different ambient conditions. SEM/EDS analysis of precipitates was performed after elapsed storage time. The results show that the presence of Mg 2+ , SO 4 2- , SiO 2 , Al, Mn and other impurities such as K + , Na + , Ba and Sr in the water controlled precipitate morphology by inhibiting crystal growth and leading to elongated rhombohedral calcite crystal forms which exhibit furrowed surfaces and calcite rosettes. Different storage conditions, however, affected the number of crystallization nuclei and size of calcite crystals. Hollow calcite spheres composed of cleavage rhombohedrons formed in the water with variable storage conditions by a combination of evaporation and precipitation of water droplets during high temperatures or by the bubble templating method.

Structural and optical properties of colloidal InZnO NPs prepared by laser ablation in liquid

NASA Astrophysics Data System (ADS)

khlewee, Maryam M.; Khashan, Khawla S.

2018-05-01

In the current work, colloidal of InZnO NPs were produced by pulsed laser ablation in liquid (PLAL) method. The effect of indium content on the structural, morphological and optical of the InZnO NPs was confirmed by Fourier transform infrared spectroscopy, Scanning electron microscopy, and UV-visible spectroscopy. The FTIR spectra showed the presence of the metal-oxide bond. The SEM exhibit different morphological aspects according to the (In/Zn) ratio. The optical transmittance of InZnO NPs has high value around 70 % in the visible region and the band gap value was varied between 3.29 to 3.25 eV.

Morphometric changes in Yellow-headed Blackbirds during summer in central North Dakota

USGS Publications Warehouse

Twedt, D.J.; Linz, G.M.

2002-01-01

Temporal stability of morphometric measurements is desirable when using avian morphology as a predictor of geographic origin. Therefore, to assess their temporal stability, we examined changes in morphology of Yellow-headed Blackbirds (Xanthocephalus xanthocephalus) from central North Dakota during summer. Measurements differed among age classes and between sexes. As expected, due to growth and maturation, measurements on hatching-year birds increased over summer. Measurements of adult plumage fluctuated with prebasic molt and exhibited age-specific discontinuities. Body mass of adult birds increased over summer, whereas both culmen length and skull length decreased. Only body length and length of internal skeletal elements were temporally stable in adult Yellow-headed Blackbirds.

Erosive processes after tectonic uplift stimulate vicariant and adaptive speciation: evolution in an Afrotemperate-endemic paper daisy genus

PubMed Central

2014-01-01

Background The role of tectonic uplift in stimulating speciation in South Africa’s only alpine zone, the Drakensberg, has not been explicitly examined. Tectonic processes may influence speciation both through the creation of novel habitats and by physically isolating plant populations. We use the Afrotemperate endemic daisy genus Macowania to explore the timing and mode (geographic versus adaptive) of speciation in this region. Between sister species pairs we expect high morphological divergence where speciation has happened in sympatry (adaptive) while with geographic (vicariant) speciation we may expect to find less morphological divergence and a greater degree of allopatry. A dated molecular phylogenetic hypothesis for Macowania elucidates species’ relationships and is used to address the potential impact of uplift on diversification. Morphological divergence of a small sample of reproductive and vegetative characters, used as a proxy for adaptive divergence, is measured against species’ range distributions to estimate mode of speciation across two subclades in the genus. Results The Macowania crown age is consistent with the hypothesis of post-uplift diversification, and we find evidence for both vicariant and adaptive speciation between the two subclades within Macowania. Both subclades exhibit strong signals of range allopatry, suggesting that geographic isolation was important in speciation. One subclade, associated with dry, rocky environments at high altitudes, shows very little morphological and ecological differentiation but high range allopatry. The other subclade occupies a greater variety of habitats and exhibits far greater morphological differentiation, but contains species with overlapping distribution ranges. Conclusions Species in Macowania are likely to have diversified in response to tectonic uplift, and we invoke uplift and uplift-mediated erosion as the main drivers of speciation. The greater relative morphological divergence in sympatric species of Macowania indicates that speciation in the non-sympatric taxa may not have required obvious adaptive differences, implying that simple geographic isolation was the driving force for speciation (‘neutral speciation’). PMID:24524661

Mass movement on Vesta at steep scarps and crater rims

NASA Astrophysics Data System (ADS)

Krohn, K.; Jaumann, R.; Otto, K.; Hoogenboom, T.; Wagner, R.; Buczkowski, D. L.; Garry, B.; Williams, D. A.; Yingst, R. A.; Scully, J.; De Sanctis, M. C.; Kneissl, T.; Schmedemann, N.; Kersten, E.; Stephan, K.; Matz, K.-D.; Pieters, C. M.; Preusker, F.; Roatsch, T.; Schenk, P.; Russell, C. T.; Raymond, C. A.

2014-12-01

The Quadrangles Av-11 and Av-12 on Vesta are located at the northern rim of the giant Rheasilvia south polar impact basin. The primary geologic units in Av-11 and Av-12 include material from the Rheasilvia impact basin formation, smooth material and different types of impact crater structures (such as bimodal craters, dark and bright crater ray material and dark ejecta material). Av-11 and Av-12 exhibit almost the full range of mass wasting features observed on Vesta, such as slump blocks, spur-and-gully morphologies and landslides within craters. Processes of collapse, slope instability and seismically triggered events force material to slump down crater walls or scarps and produce landslides or rotational slump blocks. The spur-and-gully morphology that is known to form on Mars is also observed on Vesta; however, on Vesta this morphology formed under dry conditions.

Astrocyte atrophy and immune dysfunction in self-harming macaques.

PubMed

Lee, Kim M; Chiu, Kevin B; Sansing, Hope A; Inglis, Fiona M; Baker, Kate C; MacLean, Andrew G

2013-01-01

Self-injurious behavior (SIB) is a complex condition that exhibits a spectrum of abnormal neuropsychological and locomotor behaviors. Mechanisms for neuropathogenesis could include irregular immune activation, host soluble factors, and astrocyte dysfunction. We examined the role of astrocytes as modulators of immune function in macaques with SIB. We measured changes in astrocyte morphology and function. Paraffin sections of frontal cortices from rhesus macaques identified with SIB were stained for glial fibrillary acidic protein (GFAP) and Toll-like receptor 2 (TLR2). Morphologic features of astrocytes were determined using computer-assisted camera lucida. There was atrophy of white matter astrocyte cell bodies, decreased arbor length in both white and gray matter astrocytes, and decreased bifurcations and tips on astrocytes in animals with SIB. This was combined with a five-fold increase in the proportion of astrocytes immunopositive for TLR2. These results provide direct evidence that SIB induces immune activation of astrocytes concomitant with quantifiably different morphology.

Mass Movement on Vesta at Steep Scarps and Crater Rims

NASA Technical Reports Server (NTRS)

Krohn, K.; Jaumann, R.; Otto, K.; Hoogenboom, T.; Wagner, R.; Buczkowski, D. L.; Garry, B.; Williams, D. A.; Yingst, R. A.; Scully, J.;

Surface Morphology and Hardness Analysis of TiCN Coated AA7075 Aluminium Alloy

NASA Astrophysics Data System (ADS)

Srinath, M. K.; Ganesha Prasad, M. S.

2017-12-01

Successful titanium carbonitride (TiCN) coating on AA7075 plates using the PVD technique depends upon many variables, including temperature, pressure, incident angle and energy of the reactive ions. Coated specimens have shown an increase in their surface hardness of 2.566 GPa. In this work, an attempt to further augment the surface hardness and understand its effects on the surface morphology was performed through heat treatments at 500°C for different duration of times. Specimen's heat treated at 500°C for 1 h exhibited a maximum surface hardness of 6.433 GPa, corresponding to an increase of 92.07%. The XRD results showed the presence of Al2Ti and AlTi3N and indicate the bond created between them. Unit cell lattice parameters in the XRD data are calculated using Bragg's law. The SEM images exhibit increasing crack sizes as the heat treatment time is increased. From the studies, the heat treatment duration can be optimized to 1 h, which exhibited an augmented surface hardness, as further increases in durations caused a drop in the surface hardness. The heat treatment effectively modified the surface hardness. Equations providing the relationships that temperature and time have with the reaction parameters are presented.

Effect of synthesis conditions on the nanopowder properties of Ce{sub 0.9}Zr{sub 0.1}O{sub 2}

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zimicz, M.G.; Fabregas, I.O.; Lamas, D.G.

Graphical abstract: . The synthesis of nanocrystalline Ce{sub 0.9}Zr{sub 0.1}O{sub 2} powders via the gel-combustion method, using different fuels, and following either stoichiometric or non-stoichiometric pH-controlled routes is investigated. Research highlights: {yields} All samples exhibited the fluorite-type crystal structure, nanometric average crystallite size and negligible carbon content. {yields} Synthesis conditions strongly affect the average crystallite size, the degree of agglomeration, the specific surface area and the pore volume. {yields} Our results indicate that, by controlling the synthesis conditions it is possible to obtain solids with custom-made morphological properties. -- Abstract: In this work, the synthesis of nanocrystalline Ce{sub 0.9}Zr{sub 0.1}O{submore » 2} powders via the gel-combustion method, using different fuels, and following either stoichiometric or non-stoichiometric pH-controlled routes is investigated. The objective is to evaluate the effect of synthesis conditions on the textural and morphological properties, and the crystal structure of the synthesized materials. The solids were characterized by nitrogen physisorption, Scanning Electron Microscopy (SEM), X-ray powder diffraction (XPD), and Carbon-Hydrogen-Nitrogen Elemental Analysis (CHN). All the powders exhibited nanometric crystallite size, fluorite-type structure and negligible carbon content. Synthesis conditions strongly affect the average crystallite size, the degree of agglomeration, the specific surface area and the pore volume. Our results indicate that, by controlling the synthesis conditions it is possible to obtain solids with custom-made morphological properties.« less

Adult microbiota-deficient mice have distinct dendritic morphological changes: differential effects in the amygdala and hippocampus.

PubMed

Luczynski, Pauline; Whelan, Seán O; O'Sullivan, Colette; Clarke, Gerard; Shanahan, Fergus; Dinan, Timothy G; Cryan, John F

2016-11-01

Increasing evidence implicates the microbiota in the regulation of brain and behaviour. Germ-free mice (GF; microbiota deficient from birth) exhibit altered stress hormone signalling and anxiety-like behaviours as well as deficits in social cognition. Although the mechanisms underlying the ability of the gut microbiota to influence stress responsivity and behaviour remain unknown, many lines of evidence point to the amygdala and hippocampus as likely targets. Thus, the aim of this study was to determine if the volume and dendritic morphology of the amygdala and hippocampus differ in GF versus conventionally colonized (CC) mice. Volumetric estimates revealed significant amygdalar and hippocampal expansion in GF compared to CC mice. We also studied the effect of GF status on the level of single neurons in the basolateral amygdala (BLA) and ventral hippocampus. In the BLA, the aspiny interneurons and pyramidal neurons of GF mice exhibited dendritic hypertrophy. The BLA pyramidal neurons of GF mice had more thin, stubby and mushroom spines. In contrast, the ventral hippocampal pyramidal neurons of GF mice were shorter, less branched and had less stubby and mushroom spines. When compared to controls, dentate granule cells of GF mice were less branched but did not differ in spine density. These findings suggest that the microbiota is required for the normal gross morphology and ultrastructure of the amygdala and hippocampus and that this neural remodelling may contribute to the maladaptive stress responsivity and behavioural profile observed in GF mice. © 2016 The Authors. European Journal of Neuroscience published by Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

Improved performance by morphology control via fullerenes in PBDT-TBT-alkoBT based organic solar cells

DOE PAGES

Khatiwada, Devendra; Venkatesan, Swaminathan; Chen, QIliang; ...

2015-07-03

In this work, we report improved performance by controlling morphology using different fullerene derivatives in poly{2-octyldodecyloxy-benzo[1,2-b;3,4-b]dithiophene-alt-5,6-bis(dodecyloxy)-4,7- di(thieno[3,2-b]thiophen-2-yl)-benzo[c][1,2,5]thiadiazole} (PBDT-TBT-alkoBT) based organic solar cells. PC60BM and PC70BM fullerenes were used to investigate the characteristic change in morphology and device performance. Fullerene affects device efficiency by changing active layer morphology. PC70BM with broader absorption than PC 60BM resulted in reduced device performance which was elucidated by the intermixed granular morphology separating each larger grain in the PC70BM/polymer composite layer which created higher density of traps. However after adding additive 1,8-diiodooctane (DIO), the fibrous morphology was observed due to reduced solubility of polymer andmore » increased solubility of PC 70BM in chloroform. The fibrous morphology improved charge transport leading to increase in overall device performance. Atomic force microscopies (AFM), photo induced charge extraction by linearly increasing voltage (photo-CELIV), and Kelvin prove force microscope (KPFM) were used to investigate nanoscale morphology of active layer with different fullerene derivatives. For PC 60BM based active layer, AFM images revealed dense fibrous morphology and more distinct fibrous morphology was observed by adding DIO. The PC 70BM based active layer only exhibited intermixed granular morphology instead of fibrous morphology observed in PC60BM based active layer. However, addition of DIO in PC 70BM based active layer led to fibrous morphology. When additive DIO was not used, a wider distribution of surface potential was observed for PC 70BM than PC 60BM based active layer by KPFM measurements, indicating 2 polymer and fullerene domains are separated. When DIO was used, narrower distribution of surface potential for both PC 70BM and PC 60BM based active layers was observed. Photo-CELIV experiment showed larger extracted charge carrier density and mobility in PC 70BM/DIO film.« less

Improved performance by morphology control via fullerenes in PBDT-TBT-alkoBT based organic solar cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Khatiwada, Devendra; Venkatesan, Swaminathan; Chen, QIliang

In this work, we report improved performance by controlling morphology using different fullerene derivatives in poly{2-octyldodecyloxy-benzo[1,2-b;3,4-b]dithiophene-alt-5,6-bis(dodecyloxy)-4,7- di(thieno[3,2-b]thiophen-2-yl)-benzo[c][1,2,5]thiadiazole} (PBDT-TBT-alkoBT) based organic solar cells. PC60BM and PC70BM fullerenes were used to investigate the characteristic change in morphology and device performance. Fullerene affects device efficiency by changing active layer morphology. PC70BM with broader absorption than PC 60BM resulted in reduced device performance which was elucidated by the intermixed granular morphology separating each larger grain in the PC70BM/polymer composite layer which created higher density of traps. However after adding additive 1,8-diiodooctane (DIO), the fibrous morphology was observed due to reduced solubility of polymer andmore » increased solubility of PC 70BM in chloroform. The fibrous morphology improved charge transport leading to increase in overall device performance. Atomic force microscopies (AFM), photo induced charge extraction by linearly increasing voltage (photo-CELIV), and Kelvin prove force microscope (KPFM) were used to investigate nanoscale morphology of active layer with different fullerene derivatives. For PC 60BM based active layer, AFM images revealed dense fibrous morphology and more distinct fibrous morphology was observed by adding DIO. The PC 70BM based active layer only exhibited intermixed granular morphology instead of fibrous morphology observed in PC60BM based active layer. However, addition of DIO in PC 70BM based active layer led to fibrous morphology. When additive DIO was not used, a wider distribution of surface potential was observed for PC 70BM than PC 60BM based active layer by KPFM measurements, indicating 2 polymer and fullerene domains are separated. When DIO was used, narrower distribution of surface potential for both PC 70BM and PC 60BM based active layers was observed. Photo-CELIV experiment showed larger extracted charge carrier density and mobility in PC 70BM/DIO film.« less

Effects of annealing on arrays of Ge nanocolumns formed by glancing angle deposition

NASA Astrophysics Data System (ADS)

Khare, C.; Gerlach, J. W.; Höche, T.; Fuhrmann, B.; Leipner, H. S.; Rauschenbach, B.

2012-10-01

Post-deposition thermal annealing of glancing angle deposited Ge nanocolumn arrays was carried out in a continuous Ar-flow at temperatures ranging from TA = 300 to 800 °C for different annealing durations. Morphological alterations and the recrystallization process induced by the thermal annealing treatment were investigated for the Ge nanocolumns deposited on planar and pre-patterned Si substrates. From X-ray diffraction (XRD) measurements, the films annealed at TA ≥ 500 °C were found to be polycrystalline. On planar Si substrates, at TA = 600 °C nanocolumns exhibited strong coarsening and merging, while a complete disintegration of the nanocolumns was detected at TA = 700 °C. The morphology of nanostructures deposited on pre-patterned substrates differs substantially, where the merging or column-disintegration effect was absent at elevated annealing temperatures. The two-arm-chevron nanostructures grown on pre-patterned substrates retained their complex shape and morphology, after extended annealing intervals. Investigations by transmission electron microscopy revealed nanocrystalline domains of the order of 5-30 nm (in diameter) present within the chevron structures after the annealing treatment.

Essential-Oil Variability in a Collection of Ocimum basilicum L. (Basil) Cultivars.

PubMed

Maggio, Antonella; Roscigno, Graziana; Bruno, Maurizio; De Falco, Enrica; Senatore, Felice

2016-10-01

Ocimum basilicum L. (Lamiaceae) is an aromatic plant of great tradition in the Mediterranean area. Its economic importance is growing up determining an expansion of cultivation. This paper evaluated the morphological traits, the chemical profiles, and antibacterial activity of 21 cultivars of basil belonging to 'Genovese', 'Napoletano', and 'Purple basil' types. The cultivars were characterized by different growth rate and morphological traits. The chemical composition of the oils analyzed by GC and GC/MS analysis, supported by the PCA analysis, underlined the strong influence of chemotype. It is noteworthy that estragole, never present in Genovese and purple basil types, occurred in Napoletano type. The high presence of eugenol, methyl eugenol, and linalool in the majority of cultivars, belonging both to Genovese and to Napoletano types was registered. Of great interest resulted the composition of the purple basil 'Opal'. All the samples tested exhibited similar antibiotic profiles with moderate antibacterial activity. The results enhanced the importance of determination of essential-oil profile in the selection of cultivars characterized by diverse morphological traits and are useful for different purposes. © 2016 Wiley-VHCA AG, Zürich.

Repeated adaptive divergence of microhabitat specialization in avian feather lice.

PubMed

Johnson, Kevin P; Shreve, Scott M; Smith, Vincent S

2012-06-20

Repeated adaptive radiations are evident when phenotypic divergence occurs within lineages, but this divergence into different forms is convergent when compared across lineages. Classic examples of such repeated adaptive divergence occur in island (for example, Caribbean Anolis lizards) and lake systems (for example, African cichlids). Host-parasite systems in many respects are analogous to island systems, where host species represent isolated islands for parasites whose life cycle is highly tied to that of their hosts. Thus, host-parasite systems might exhibit interesting cases of repeated adaptive divergence as seen in island and lake systems.The feather lice of birds spend their entire life cycle on the body of the host and occupy distinct microhabitats on the host: head, wing, body and generalist. These microhabitat specialists show pronounced morphological differences corresponding to how they escape from host preening. We tested whether these different microhabitat specialists were a case of repeated adaptive divergence by constructing both morphological and molecular phylogenies for a diversity of avian feather lice, including many examples of head, wing, body and generalist forms. Morphological and molecular based phylogenies were highly incongruent, which could be explained by rampant convergence in morphology related to microhabitat specialization on the host. In many cases lice from different microhabitat specializations, but from the same group of birds, were sister taxa. This pattern indicates a process of repeated adaptive divergence of these parasites within host group, but convergence when comparing parasites across host groups. These results suggest that host-parasite systems might be another case in which repeated adaptive radiations could be relatively common, but potentially overlooked, because morphological convergence can obscure evolutionary relationships.

Extreme Postnatal Scaling in Bat Feeding Performance: A View of Ecomorphology from Ontogenetic and Macroevolutionary Perspectives.

PubMed

Santana, Sharlene E; Miller, Kimberly E

2016-09-01

Ecomorphology studies focus on understanding how anatomical and behavioral diversity result in differences in performance, ecology, and fitness. In mammals, the determinate growth of the skeleton entails that bite performance should change throughout ontogeny until the feeding apparatus attains its adult size and morphology. Then, interspecific differences in adult phenotypes are expected to drive food resource partitioning and patterns of lineage diversification. However, Formal tests of these predictions are lacking for the majority of mammal groups, and thus our understanding of mammalian ecomorphology remains incomplete. By focusing on a fundamental measure of feeding performance, bite force, and capitalizing on the extraordinary morphological and dietary diversity of bats, we discuss how the intersection of ontogenetic and macroevolutionary changes in feeding performance may impact ecological diversity in these mammals. We integrate data on cranial morphology and bite force gathered through longitudinal studies of captive animals and comparative studies of free-ranging individuals. We demonstrate that ontogenetic trajectories and evolutionary changes in bite force are highly dependent on changes in body and head size, and that bats exhibit dramatic, allometric increases in bite force during ontogeny. Interspecific variation in bite force is highly dependent on differences in cranial morphology and function, highlighting selection for ecological specialization. While more research is needed to determine how ontogenetic changes in size and bite force specifically impact food resource use and fitness in bats, interspecific diversity in cranial morphology and bite performance seem to closely match functional differences in diet. Altogether, these results suggest direct ecomorphological relationships at ontogenetic and macroevolutionary scales in bats. © The Author 2016. Published by Oxford University Press on behalf of the Society for Integrative and Comparative Biology. All rights reserved. For permissions please email: journals.permissions@oup.com.

Repeated adaptive divergence of microhabitat specialization in avian feather lice

PubMed Central

2012-01-01

Background Repeated adaptive radiations are evident when phenotypic divergence occurs within lineages, but this divergence into different forms is convergent when compared across lineages. Classic examples of such repeated adaptive divergence occur in island (for example, Caribbean Anolis lizards) and lake systems (for example, African cichlids). Host-parasite systems in many respects are analogous to island systems, where host species represent isolated islands for parasites whose life cycle is highly tied to that of their hosts. Thus, host-parasite systems might exhibit interesting cases of repeated adaptive divergence as seen in island and lake systems. The feather lice of birds spend their entire life cycle on the body of the host and occupy distinct microhabitats on the host: head, wing, body and generalist. These microhabitat specialists show pronounced morphological differences corresponding to how they escape from host preening. We tested whether these different microhabitat specialists were a case of repeated adaptive divergence by constructing both morphological and molecular phylogenies for a diversity of avian feather lice, including many examples of head, wing, body and generalist forms. Results Morphological and molecular based phylogenies were highly incongruent, which could be explained by rampant convergence in morphology related to microhabitat specialization on the host. In many cases lice from different microhabitat specializations, but from the same group of birds, were sister taxa. Conclusions This pattern indicates a process of repeated adaptive divergence of these parasites within host group, but convergence when comparing parasites across host groups. These results suggest that host-parasite systems might be another case in which repeated adaptive radiations could be relatively common, but potentially overlooked, because morphological convergence can obscure evolutionary relationships. PMID:22717002

Analysis of Historic Copper Patinas. Influence of Inclusions on Patina Uniformity

PubMed Central

Chang, Tingru; Odnevall Wallinder, Inger; de la Fuente, Daniel; Chico, Belen; Morcillo, Manuel; Welter, Jean-Marie; Leygraf, Christofer

2017-01-01

The morphology and elemental composition of cross sections of eight historic copper materials have been explored. The materials were taken from copper roofs installed in different middle and northern European environments from the 16th to the 19th century. All copper substrates contain inclusions of varying size, number and composition, reflecting different copper ores and production methods. The largest inclusions have a size of up to 40 μm, with most inclusions in the size ranging between 2 and 10 μm. The most common element in the inclusions is O, followed by Pb, Sb and As. Minor elements include Ni, Sn and Fe. All historic patinas exhibit quite fragmentized bilayer structures, with a thin inner layer of cuprite (Cu2O) and a thicker outer one consisting mainly of brochantite (Cu4SO4(OH)6). The extent of patina fragmentation seems to depend on the size of the inclusions, rather than on their number and elemental composition. The larger inclusions are electrochemically nobler than the surrounding copper matrix. This creates micro-galvanic effects resulting both in a profound influence on the homogeneity and morphology of historic copper patinas and in a significantly increased ratio of the thicknesses of the brochantite and cuprite layers. The results suggest that copper patinas formed during different centuries exhibit variations in uniformity and corrosion protection ability. PMID:28772659

Foraging strategies in trees of different root morphology: the role of root lifespan.

PubMed

Adams, Thomas S; McCormack, M Luke; Eissenstat, David M

2013-09-01

Resource exploitation of patches is influenced not simply by the rate of root production in the patches but also by the lifespan of the roots inhabiting the patches. We examined the effect of sustained localized nitrogen (N) fertilization on root lifespan in four tree species that varied widely in root morphology and presumed foraging strategy. The study was conducted in a 12-year-old common garden in central Pennsylvania using a combination of data from minirhizotron and root in-growth cores. The two fine-root tree species, Acer negundo L. and Populus tremuloides Michx., exhibited significant increases in root lifespan with local N fertilization; no significant responses were observed in the two coarse-root tree species, Sassafras albidum Nutt. and Liriodendron tulipifera L. Across species, coarse-root tree species had longer median root lifespan than fine-root tree species. Localized N fertilization did not significantly increase the N concentration or the respiration of the roots growing in the N-rich patch. Our results suggest that some plant species appear to regulate the lifespan of different portions of their root system to improve resource acquisition while other species do not. Our results are discussed in the context of different strategies of foraging of nutrient patches in species of different root morphology.

Functional analyses of the primate upper cervical vertebral column.

PubMed

Nalley, Thierra K; Grider-Potter, Neysa

2017-06-01

Recent work has highlighted functional correlations between direct measures of head and neck posture and primate cervical bony morphology. Primates with more horizontal necks exhibit middle and lower cervical vertebral features that indicate increased mechanical advantage for deep nuchal musculature and mechanisms for column curvature formation and maintenance. How features of the C1 and C2 reflect quantified measures of posture have yet to be examined. This study incorporates bony morphology from the upper cervical levels from 20 extant primate species in order to investigate further how posture correlates with cervical vertebrae morphology. Results from phylogenetic generalized least-squares analyses indicate that few vertebral features exhibit a significant relationship with posture when accounting for differences in size. When size-adjusted traits were correlated with posture, vertebral variation had a stronger relationship with neck posture than head posture variables. Two C1 traits-relative posterior arch length and superior facet curvature-were correlated with neck posture variables. Relative posterior arch length exhibits a positive relationship with neck posture, while superior articular facet curvature demonstrates a negative relationship, such that as the neck becomes more horizontal, the greater the facet curvature. Four C2 features were also correlated with neck posture: relative pedicle and lamina lengths, relative superior facet orientation, and dens orientation. Relative pedicle and lamina lengths become craniocaudally longer as the neck becomes more horizontal. Relative C2 superior facet orientation and dens orientation exhibit negative correlations with posture, such that as the neck becomes more horizontal, the superior facet becomes more caudally inclined and the dens more dorsally inclined. These results produce a similar functional signal observed in the middle and lower cervical spine. Modeling the cervical vertebrae of more pronograde taxa within a sigmoidal spinal column model is further discussed and may prove useful in refining and testing future hypotheses of primate cervical mechanics. Copyright © 2017 Elsevier Ltd. All rights reserved.

The risk of recrystallization: changes to the toxicity and morphology of pyrimethamine.

PubMed

Perold, Zak; Caira, Mino R; Brits, Marius

2014-01-01

Pyrimethamine, an anti-malarial agent known to exhibit solid state polymorphism, may be purified by means of recrystallization. Recrystallization may alter the solid state chemistry of pharmaceuticals, which may impact the toxicity and/or manufacturability thereof. We evaluated the risks associated with the recrystallization of pyrimethamine. Pyrimethamine was recrystallized using several organic solvents. X-ray diffraction, thermal analysis, infra-red spectroscopy, microscopy, flowability -, solubility and dissolution testing as well as computational work were employed to evaluate the recrystallized products. A toxic solvatomorph of pyrimethamine (Pyr-MeOH) was found to be the product from methanol recrystallization. The elucidation of - and the elaboration on the unique characteristics of Pyr-MeOH provides the pharmaceutical industry with several means to identify Pyr-MeOH and to distinguish it from the pharmaceutically preferred anhydrous form (Pyr). Thermal methods of analysis found that the toxicity of Pyr-MeOH may be reversed by overcoming a desolvation activation energy of 148 kJ/mol. In addition it was found that recrystallization altered the morphology of Pyr. Angle of repose and tapped density determinations identified that the different morphologies of Pyr displayed differences in powder flow and compressibility behaviour and In Silico calculations were successful in rendering morphologies resembling that found experimentally. We present a solvatomorph of pyrimethamine and provide several characteristic means to identify this unwanted toxic form and quantified the energy required to overcome its toxicity. In addition we describe that Pyr may present in different morphologies and show how it may impact the manufacturability thereof.

Creole English Speakers' Treatment of Tense-Aspect Morphology in English Interlanguage Written Discourse

ERIC Educational Resources Information Center

Clachar, Arlene

2005-01-01

The study sought to examine the effect of lexical aspect and narrative discourse structure on the pattern of acquisition and use of English verbal morphology exhibited by creole-speaking students. Findings indicated that the emergent pattern of morphology in the creole participants' written interlanguage appeared to be influenced not only by…

Morphology of pulp fiber from hardwoods and influence on paper strength

Treesearch

Richard A. Horn

1978-01-01

The results of this investigation showed that physical properties of sheets made from hardwood fiber are very dependent upon fiber morphology. Chemical variation of pulp fibers did not exhibit an influence on sheet strength. Of the morphological characteristics investigated, those contributing the most were fiber length, L/T ratio, and fibril angle. Hardwood fines (...

Morphological Segregation in the Surroundings of Cosmic Voids

NASA Astrophysics Data System (ADS)

Ricciardelli, Elena; Cava, Antonio; Varela, Jesus; Tamone, Amelie

2017-09-01

We explore the morphology of galaxies living in the proximity of cosmic voids, using a sample of voids identified in the Sloan Digital Sky Survey Data Release 7. At all stellar masses, void galaxies exhibit morphologies of a later type than galaxies in a control sample, which represent galaxies in an average density environment. We interpret this trend as a pure environmental effect, independent of the mass bias, due to a slower galaxy build-up in the rarefied regions of voids. We confirm previous findings about a clear segregation in galaxy morphology, with galaxies of a later type being found at smaller void-centric distances with respect to the early-type galaxies. We also show, for the first time, that the radius of the void has an impact on the evolutionary history of the galaxies that live within it or in its surroundings. In fact, an enhanced fraction of late-type galaxies is found in the proximity of voids larger than the median void radius. Likewise, an excess of early-type galaxies is observed within or around voids of a smaller size. A significant difference in galaxy properties in voids of different sizes is observed up to 2 R void, which we define as the region of influence of voids. The significance of this difference is greater than 3σ for all the volume-complete samples considered here. The fraction of star-forming galaxies shows the same behavior as the late-type galaxies, but no significant difference in stellar mass is observed in the proximity of voids of different sizes.

Carbon Dots/NiCo2 O4 Nanocomposites with Various Morphologies for High Performance Supercapacitors.

PubMed

Wei, Ji-Shi; Ding, Hui; Zhang, Peng; Song, Yan-Fang; Chen, Jie; Wang, Yong-Gang; Xiong, Huan-Ming

2016-11-01

A series of carbon dots/NiCo 2 O 4 composites with various morphologies are prepared and tested for supercapacitors. These samples have good electrical conductivities and efficient ions transport paths, so they exhibit high specific capacitances, superior rate performances, and high cycling stabilities. The optimal composite for hybrid supercapacitor exhibits a high energy density up to 62.0 Wh kg -1 . © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Size determines antennal sensitivity and behavioral threshold to odors in bumblebee workers

NASA Astrophysics Data System (ADS)

Spaethe, Johannes; Brockmann, Axel; Halbig, Christine; Tautz, Jürgen

2007-09-01

The eusocial bumblebees exhibit pronounced size variation among workers of the same colony. Differently sized workers engage in different tasks (alloethism); large individuals are found to have a higher probability to leave the colony and search for food, whereas small workers tend to stay inside the nest and attend to nest duties. We investigated the effect of size variation on morphology and physiology of the peripheral olfactory system and the behavioral response thresholds to odors in workers of Bombus terrestris. Number and density of olfactory sensilla on the antennae correlate significantly with worker size. Consistent with these morphological changes, we found that antennal sensitivity to odors increases with body size. Antennae of large individuals show higher electroantennogram responses to a given odor concentration than those of smaller nestmates. This finding indicates that large antennae exhibit an increased capability to catch odor molecules and thus are more sensitive to odors than small antennae. We confirmed this prediction in a dual choice behavioral experiment showing that large workers indeed are able to respond correctly to much lower odor concentrations than small workers. Learning performance in these experiments did not differ between small and large bumblebees. Our results clearly show that, in the social bumblebees, variation in olfactory sensilla number due to size differences among workers strongly affects individual odor sensitivity. We speculate that superior odor sensitivity of large workers has favored size-related division of labor in bumblebee colonies.

The granulocytes are the main immunocompetent hemocytes in Crassostrea gigas.

PubMed

Wang, Weilin; Li, Meijia; Wang, Lingling; Chen, Hao; Liu, Zhaoqun; Jia, Zhihao; Qiu, Limei; Song, Linsheng

2017-02-01

Hemocytes comprise diverse cell types with morphological and functional heterogeneity and play indispensable roles in immunological homeostasis of invertebrates. The morphological classification of different hemocytes in mollusk has been studied since the 1970's, yet the involvement of the different sub-populations in immune functions is far from clear. In the present study, three types of hemocytes were morphologically identified and separated as agranulocytes, semi-granulocytes and granulocytes by flow cytometry and Percoll ® density gradient centrifugation. The granulocytes were characterized functionally as the main phagocytic and encapsulating population, while semi-granulocytes and agranulocytes exhibited low or no such capacities, respectively. Meanwhile, the lysosome activity and the productions of ROS and NO were all mainly concentrated in granulocytes under both normal and immune-activated situations. Further, the mRNA transcripts of some immune related genes, including CgTLR, CgClathrin, CgATPeV, CgLysozyme, CgDefensin and CgIL-17, were mainly expressed in granulocytes, lower in semi-granulocytes and agranulocytes. These results collectively suggested that the granulocytes were the main immunocompetent hemocytes in oyster C. gigas, and a differentiation relationship among these three sub-population hemocytes was inferred based on the gradual changes in morphological, functional and molecular features. Copyright © 2016 Elsevier Ltd. All rights reserved.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lin, Xiaomei; Lv, Xin; Wang, Limin

Graphical abstract: - Highlights: • Effect of CTAB on the morphology and crystallization of MnFe{sub 2}O{sub 4}. • The lowest coercivity of MnFe{sub 2}O{sub 4} polyhedron is 11.9 Oe. • MnFe{sub 2}O{sub 4} as anode for LIB shows good reversible capacity and cycle performances. - Abstract: The uniform different morphologies MnFe{sub 2}O{sub 4}, including cube, truncated cube, polyhedron and octahedron, were successfully synthesized via a solvothermal route using cetyltrimethylammonium bromide. The results of control experiments revealed that the concentration of cetyltrimethylammonium bromide was an important factor, which affected the morphology and crystallization of MnFe{sub 2}O{sub 4} submicro-crystals. All the preparedmore » samples exhibited soft-magnetic behavior at room temperature. Especially, the coercivity of MnFe{sub 2}O{sub 4} polyhedron with 200 nm diameter was 11.9 Oe, which was among the lowest values reported so far. Moreover, MnFe{sub 2}O{sub 4} submicro-crystals with special morphologies demonstrated higher reversible capacity (about 1000 mAh g{sup −1}) and different cycle performances. After 50 cycles, polyhedron structure remained 428 mAh/g. The MnFe{sub 2}O{sub 4} would have a potential application as anode material for lithium ion batteries.« less

Tungsten substituted molybdophosphoric acid loaded on various types of mesoporous silica SBA-15 for application of thorium ion adsorption

NASA Astrophysics Data System (ADS)

Aghayan, H.; Khanchi, A. R.; Yousefi, T.; Ghasemi, H.

2017-12-01

In this research, three type of mesoporous silica with different morphologies, namely fibers, spheres and platelets were synthesized and used as a support for immobilization of [H3PMo6W6O40].nH2O. The samples were then applied as an inorganic composite ion-exchanger for sorption of thorium from aqueous solution. Various techniques including ICP, XRD, BET, SEM and FT-IR methods were used to characterize of the products. The experiment results showed that the [H3PMo6W6O40].nH2O supported on the platelet mesoporous silica exhibited both the highest sorption capacity and fastest kinetics when compared with the fibers and spheres adsorbents. Our results show that the morphology of the mesoporous support, which can produce different channel lengths, pore size and surface area, has a serious effect on the sorption properties and influences: (1) the amount of loading of heteropoly acid in the support (2) the kinetic of the sorption process and (3) the maximum of adsorption capacity. The platelet morphology showed the shortest equilibrium time, the highest loading amount and the highest adsorption capacity therefore delivering the best performance among the three morphologies.

Pyrolytic carbon membranes containing silica: morphological approach on gas transport behavior

NASA Astrophysics Data System (ADS)

Park, Ho Bum; Lee, Sun Yong; Lee, Young Moo

2005-04-01

Pyrolytic carbon membrane containing silica (C-SiO 2) is a new-class material for gas separation, and in the present work we will deal with it in view of the morphological changes arising from the difference in the molecular structure of the polymeric precursors. The silica embedded carbon membranes were fabricated by a predetermined pyrolysis step using imide-siloxane copolymers (PISs) that was synthesized from benzophenone tetracarboxylic dianhydrides (BTDA), 4,4'-oxydianiline (ODA), and amine-terminated polydimethylsiloxane (PDMS). To induce different morphologies at the same chemical composition, the copolymers were prepared using one-step (preferentially a random segmented copolymer) sand two-step polymerization (a block segmented copolymer) methods. The polymeric precursors and their pyrolytic C-SiO 2 membranes were analyzed using thermal analysis, atomic force microscopy, and transmission electron microscopy, etc. It was found that the C-SiO 2 membrane derived from the random PIS copolymer showed a micro-structure containing small well-dispersed silica domains, whereas the C-SiO 2 membrane from the block PIS copolymer exhibited a micro-structure containing large silica domains in the continuous carbon matrix. Eventually, the gas transport through these C-SiO 2 membranes was significantly affected by the morphological changes of the polymeric precursors.

Classification model based on Raman spectra of selected morphological and biochemical tissue constituents for identification of atherosclerosis in human coronary arteries.

PubMed

Peres, Marines Bertolo; Silveira, Landulfo; Zângaro, Renato Amaro; Pacheco, Marcos Tadeu Tavares; Pasqualucci, Carlos Augusto

2011-09-01

This study presents the results of Raman spectroscopy applied to the classification of arterial tissue based on a simplified model using basal morphological and biochemical information extracted from the Raman spectra of arteries. The Raman spectrograph uses an 830-nm diode laser, imaging spectrograph, and a CCD camera. A total of 111 Raman spectra from arterial fragments were used to develop the model, and those spectra were compared to the spectra of collagen, fat cells, smooth muscle cells, calcification, and cholesterol in a linear fit model. Non-atherosclerotic (NA), fatty and fibrous-fatty atherosclerotic plaques (A) and calcified (C) arteries exhibited different spectral signatures related to different morphological structures presented in each tissue type. Discriminant analysis based on Mahalanobis distance was employed to classify the tissue type with respect to the relative intensity of each compound. This model was subsequently tested prospectively in a set of 55 spectra. The simplified diagnostic model showed that cholesterol, collagen, and adipocytes were the tissue constituents that gave the best classification capability and that those changes were correlated to histopathology. The simplified model, using spectra obtained from a few tissue morphological and biochemical constituents, showed feasibility by using a small amount of variables, easily extracted from gross samples.

Astragalar Morphology of Selected Giraffidae.

PubMed

Solounias, Nikos; Danowitz, Melinda

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.

Exploring the nature of ecological specialization in a coral reef fish community: morphology, diet and foraging microhabitat use

PubMed Central

Brandl, Simon J.; Robbins, William D.; Bellwood, David R.

2015-01-01

Patterns of ecological specialization offer invaluable information about ecosystems. Yet, specialization is rarely quantified across several ecological niche axes and variables beyond the link between morphological and dietary specialization have received little attention. Here, we provide a quantitative evaluation of ecological specialization in a coral reef fish assemblage (f. Acanthuridae) along one fundamental and two realized niche axes. Specifically, we examined ecological specialization in 10 surgeonfish species with regards to morphology and two realized niche axes associated with diet and foraging microhabitat utilization using a recently developed multidimensional framework. We then investigated the potential relationships between morphological and behavioural specialization. These relationships differed markedly from the traditional ecomorphological paradigm. While morphological specialization showed no relationship with dietary specialization, it exhibited a strong relationship with foraging microhabitat specialization. However, this relationship was inverted: species with specialized morphologies were microhabitat generalists, whereas generalized morphotypes were microhabitat specialists. Interestingly, this mirrors relationships found in plant–pollinator communities and may also be applicable to other ecosystems, highlighting the potential importance of including niche axes beyond dietary specialization into ecomorphological frameworks. On coral reefs, it appears that morphotypes commonly perceived as most generalized may, in fact, be specialized in exploiting flat and easily accessible microhabitats. PMID:26354935

Exploring the nature of ecological specialization in a coral reef fish community: morphology, diet and foraging microhabitat use.

PubMed

Brandl, Simon J; Robbins, William D; Bellwood, David R

2015-09-22

Patterns of ecological specialization offer invaluable information about ecosystems. Yet, specialization is rarely quantified across several ecological niche axes and variables beyond the link between morphological and dietary specialization have received little attention. Here, we provide a quantitative evaluation of ecological specialization in a coral reef fish assemblage (f. Acanthuridae) along one fundamental and two realized niche axes. Specifically, we examined ecological specialization in 10 surgeonfish species with regards to morphology and two realized niche axes associated with diet and foraging microhabitat utilization using a recently developed multidimensional framework. We then investigated the potential relationships between morphological and behavioural specialization. These relationships differed markedly from the traditional ecomorphological paradigm. While morphological specialization showed no relationship with dietary specialization, it exhibited a strong relationship with foraging microhabitat specialization. However, this relationship was inverted: species with specialized morphologies were microhabitat generalists, whereas generalized morphotypes were microhabitat specialists. Interestingly, this mirrors relationships found in plant-pollinator communities and may also be applicable to other ecosystems, highlighting the potential importance of including niche axes beyond dietary specialization into ecomorphological frameworks. On coral reefs, it appears that morphotypes commonly perceived as most generalized may, in fact, be specialized in exploiting flat and easily accessible microhabitats. © 2015 The Author(s).

Allometry of root branching and its relationship to root morphological and functional traits in three range grasses.

PubMed

Arredondo, J Tulio; Johnson, Douglas A

2011-11-01

The study of proportional relationships between size, shape, and function of part of or the whole organism is traditionally known as allometry. Examination of correlative changes in the size of interbranch distances (IBDs) at different root orders may help to identify root branching rules. Root morphological and functional characteristics in three range grasses {bluebunch wheatgrass [Pseudoroegneria spicata (Pursh) Löve], crested wheatgrass [Agropyron desertorum (Fisch. ex Link) Schult.×A. cristatum (L.) Gaert.], and cheatgrass (Bromus tectorum L.)} were examined in response to a soil nutrient gradient. Interbranch distances along the main root axis and the first-order laterals as well as other morphological and allocation root traits were determined. A model of nutrient diffusivity parameterized with root length and root diameter for the three grasses was used to estimate root functional properties (exploitation efficiency and exploitation potential). The results showed a significant negative allometric relationship between the main root axis and first-order lateral IBD (P ≤ 0.05), but only for bluebunch wheatgrass. The main root axis IBD was positively related to the number and length of roots, estimated exploitation efficiency of second-order roots, and specific root length, and was negatively related to estimated exploitation potential of first-order roots. Conversely, crested wheatgrass and cheatgrass, which rely mainly on root proliferation responses, exhibited fewer allometric relationships. Thus, the results suggested that species such as bluebunch wheatgrass, which display slow root growth and architectural root plasticity rather than opportunistic root proliferation and rapid growth, exhibit correlative allometry between the main axis IBD and morphological, allocation, and functional traits of roots.

Annealing induced low coercivity, nanocrystalline Co-Fe-Si thin films exhibiting inverse cosine angular variation

NASA Astrophysics Data System (ADS)

Hysen, T.; Al-Harthi, Salim; Al-Omari, I. A.; Geetha, P.; Lisha, R.; Ramanujan, R. V.; Sakthikumar, D.; Anantharaman, M. R.

2013-09-01

Co-Fe-Si based films exhibit high magnetic moments and are highly sought after for applications like soft under layers in perpendicular recording media to magneto-electro-mechanical sensor applications. In this work the effect of annealing on structural, morphological and magnetic properties of Co-Fe-Si thin films was investigated. Compositional analysis using X-ray photoelectron spectroscopy and secondary ion mass spectroscopy revealed a native oxide surface layer consisting of oxides of Co, Fe and Si on the surface. The morphology of the as deposited films shows mound like structures conforming to the Volmer-Weber growth model. Nanocrystallisation of amorphous films upon annealing was observed by glancing angle X-ray diffraction and transmission electron microscopy. The evolution of magnetic properties with annealing is explained using the Herzer model. Vibrating sample magnetometry measurements carried out at various angles from 0° to 90° to the applied magnetic field were employed to study the angular variation of coercivity. The angular variation fits the modified Kondorsky model. Interestingly, the coercivity evolution with annealing deduced from magneto-optical Kerr effect studies indicates a reverse trend compared to magetisation observed in the bulk. This can be attributed to a domain wall pinning at native oxide layer on the surface of thin films. The evolution of surface magnetic properties is correlated with morphology evolution probed using atomic force microscopy. The morphology as well as the presence of the native oxide layer dictates the surface magnetic properties and this is corroborated by the apparent difference in the bulk and surface magnetic properties.

Developmental evidence for obstetric adaptation of the human female pelvis.

PubMed

Huseynov, Alik; Zollikofer, Christoph P E; Coudyzer, Walter; Gascho, Dominic; Kellenberger, Christian; Hinzpeter, Ricarda; Ponce de León, Marcia S

2016-05-10

The bony pelvis of adult humans exhibits marked sexual dimorphism, which is traditionally interpreted in the framework of the "obstetrical dilemma" hypothesis: Giving birth to large-brained/large-bodied babies requires a wide pelvis, whereas efficient bipedal locomotion requires a narrow pelvis. This hypothesis has been challenged recently on biomechanical, metabolic, and biocultural grounds, so that it remains unclear which factors are responsible for sex-specific differences in adult pelvic morphology. Here we address this issue from a developmental perspective. We use methods of biomedical imaging and geometric morphometrics to analyze changes in pelvic morphology from late fetal stages to adulthood in a known-age/known-sex forensic/clinical sample. Results show that, until puberty, female and male pelves exhibit only moderate sexual dimorphism and follow largely similar developmental trajectories. With the onset of puberty, however, the female trajectory diverges substantially from the common course, resulting in rapid expansion of obstetrically relevant pelvic dimensions up to the age of 25-30 y. From 40 y onward females resume a mode of pelvic development similar to males, resulting in significant reduction of obstetric dimensions. This complex developmental trajectory is likely linked to the pubertal rise and premenopausal fall of estradiol levels and results in the obstetrically most adequate pelvic morphology during the time of maximum female fertility. The evidence that hormones mediate female pelvic development and morphology supports the view that solutions of the obstetrical dilemma depend not only on selection and adaptation but also on developmental plasticity as a response to ecological/nutritional factors during a female's lifetime.

Developmental evidence for obstetric adaptation of the human female pelvis

PubMed Central

Huseynov, Alik; Zollikofer, Christoph P. E.; Coudyzer, Walter; Gascho, Dominic; Kellenberger, Christian; Hinzpeter, Ricarda; Ponce de León, Marcia S.

2016-01-01

The bony pelvis of adult humans exhibits marked sexual dimorphism, which is traditionally interpreted in the framework of the “obstetrical dilemma” hypothesis: Giving birth to large-brained/large-bodied babies requires a wide pelvis, whereas efficient bipedal locomotion requires a narrow pelvis. This hypothesis has been challenged recently on biomechanical, metabolic, and biocultural grounds, so that it remains unclear which factors are responsible for sex-specific differences in adult pelvic morphology. Here we address this issue from a developmental perspective. We use methods of biomedical imaging and geometric morphometrics to analyze changes in pelvic morphology from late fetal stages to adulthood in a known-age/known-sex forensic/clinical sample. Results show that, until puberty, female and male pelves exhibit only moderate sexual dimorphism and follow largely similar developmental trajectories. With the onset of puberty, however, the female trajectory diverges substantially from the common course, resulting in rapid expansion of obstetrically relevant pelvic dimensions up to the age of 25–30 y. From 40 y onward females resume a mode of pelvic development similar to males, resulting in significant reduction of obstetric dimensions. This complex developmental trajectory is likely linked to the pubertal rise and premenopausal fall of estradiol levels and results in the obstetrically most adequate pelvic morphology during the time of maximum female fertility. The evidence that hormones mediate female pelvic development and morphology supports the view that solutions of the obstetrical dilemma depend not only on selection and adaptation but also on developmental plasticity as a response to ecological/nutritional factors during a female’s lifetime. PMID:27114515

Morphological and community changes of turf algae in competition with corals

NASA Astrophysics Data System (ADS)

Cetz-Navarro, Neidy P.; Quan-Young, Lizette I.; Espinoza-Avalos, Julio

2015-08-01

The morphological plasticity and community responses of algae competing with corals have not been assessed. We evaluated eight morphological characters of four species of stoloniferous clonal filamentous turf algae (FTA), including Lophosiphonia cristata (Lc) and Polysiphonia scopulorum var. villum (Psv), and the composition and number of turf algae (TA) in competition for space with the coral Orbicella spp. under experimental and non-manipulated conditions. All FTA exhibited morphological responses, such as increasing the formation of new ramets (except for Psv when competing with O. faveolata). Opposite responses in the space between erect axes were found when Psv competed with O. faveolata and when Lc competed with O. annularis. The characters modified by each FTA species, and the number and composition of TA species growing next to coral tissue differed from that of the TA growing at ≥3 cm. The specific and community responses indicate that some species of TA can actively colonise coral tissue and that fundamental competitive interactions between the two types of organisms occur within the first millimetres of the coral-algal boundary. These findings suggest that the morphological plasticity, high number, and functional redundancy of stoloniferous TA species favour their colonisation of coral tissue and resistance against coral invasion.

Rate and extent of protein localization is controlled by peptide-binding domain association kinetics and morphology.

PubMed

Mills, Evan; Truong, Kevin

2009-06-01

Protein localization is an important regulatory mechanism in many cell signaling pathways such as cytoskeletal organization and genetic regulation. The specific mechanism of protein localization determines the kinetics and morphological constraints of protein translocation, and thus affects the rate and extent of localization. To investigate the affect of localization kinetics and morphology on protein localization, we designed a protein localization system based on Ca(2+)-calmodulin and Src homology 3 domain binding peptides that can translocate between specific localizations in response to a Ca(2+) signal. We used a stochastic biomolecular simulator to predict that such a protein localization system will exhibit slower and less complete translocations when the association kinetics of a binding domain and peptide are reduced. As well, we predicted that increasing the diffusion resistance by manipulating the morphology of the system would similarly impair translocation speed and completeness. We then constructed a network of synthetic fusion proteins and showed that these predictions could be qualitatively confirmed in vitro. This work provides a basis for explaining the different characteristics (rate and extent) of protein transport and localization in cells as a consequence of the kinetics and morphology of the transport mechanism.

Morphological and community changes of turf algae in competition with corals.

PubMed

Cetz-Navarro, Neidy P; Quan-Young, Lizette I; Espinoza-Avalos, Julio

2015-08-05

The morphological plasticity and community responses of algae competing with corals have not been assessed. We evaluated eight morphological characters of four species of stoloniferous clonal filamentous turf algae (FTA), including Lophosiphonia cristata (Lc) and Polysiphonia scopulorum var. villum (Psv), and the composition and number of turf algae (TA) in competition for space with the coral Orbicella spp. under experimental and non-manipulated conditions. All FTA exhibited morphological responses, such as increasing the formation of new ramets (except for Psv when competing with O. faveolata). Opposite responses in the space between erect axes were found when Psv competed with O. faveolata and when Lc competed with O. annularis. The characters modified by each FTA species, and the number and composition of TA species growing next to coral tissue differed from that of the TA growing at ≥ 3 cm. The specific and community responses indicate that some species of TA can actively colonise coral tissue and that fundamental competitive interactions between the two types of organisms occur within the first millimetres of the coral-algal boundary. These findings suggest that the morphological plasticity, high number, and functional redundancy of stoloniferous TA species favour their colonisation of coral tissue and resistance against coral invasion.

Form and function of the human and chimpanzee forefoot: implications for early hominin bipedalism.

PubMed

Fernández, Peter J; Holowka, Nicholas B; Demes, Brigitte; Jungers, William L

2016-07-28

During bipedal walking, modern humans dorsiflex their forefoot at the metatarsophalangeal joints (MTPJs) prior to push off, which tightens the plantar soft tissues to convert the foot into a stiff propulsive lever. Particular features of metatarsal head morphology such as "dorsal doming" are thought to facilitate this stiffening mechanism. In contrast, chimpanzees are believed to possess MTPJ morphology that precludes high dorsiflexion excursions during terrestrial locomotion. The morphological affinity of the metatarsal heads has been used to reconstruct locomotor behavior in fossil hominins, but few studies have provided detailed empirical data to validate the assumed link between morphology and function at the MTPJs. Using three-dimensional kinematic and morphometric analyses, we show that humans push off with greater peak dorsiflexion angles at all MTPJs than do chimpanzees during bipedal and quadrupedal walking, with the greatest disparity occurring at MTPJ 1. Among MTPJs 2-5, both species exhibit decreasing peak angles from medial to lateral. This kinematic pattern is mirrored in the morphometric analyses of metatarsal head shape. Analyses of Australopithecus afarensis metatarsals reveal morphology intermediate between humans and chimpanzees, suggesting that this species used different bipedal push-off kinematics than modern humans, perhaps resulting in a less efficient form of bipedalism.

The functional and palaeoecological implications of tooth morphology and wear for the megaherbivorous dinosaurs from the Dinosaur Park Formation (upper Campanian) of Alberta, Canada.

PubMed

Mallon, Jordan C; Anderson, Jason S

2014-01-01

Megaherbivorous dinosaurs were exceptionally diverse on the Late Cretaceous island continent of Laramidia, and a growing body of evidence suggests that this diversity was facilitated by dietary niche partitioning. We test this hypothesis using the fossil megaherbivore assemblage from the Dinosaur Park Formation (upper Campanian) of Alberta as a model. Comparative tooth morphology and wear, including the first use of quantitative dental microwear analysis in the context of Cretaceous palaeosynecology, are used to infer the mechanical properties of the foods these dinosaurs consumed. The phylliform teeth of ankylosaurs were poorly adapted for habitually processing high-fibre plant matter. Nevertheless, ankylosaur diets were likely more varied than traditionally assumed: the relatively large, bladed teeth of nodosaurids would have been better adapted to processing a tougher, more fibrous diet than the smaller, cusp-like teeth of ankylosaurids. Ankylosaur microwear is characterized by a preponderance of pits and scratches, akin to modern mixed feeders, but offers no support for interspecific dietary differences. The shearing tooth batteries of ceratopsids are much better adapted to high-fibre herbivory, attested by their scratch-dominated microwear signature. There is tentative microwear evidence to suggest differences in the feeding habits of centrosaurines and chasmosaurines, but statistical support is not significant. The tooth batteries of hadrosaurids were capable of both shearing and crushing functions, suggestive of a broad dietary range. Their microwear signal overlaps broadly with that of ankylosaurs, and suggests possible dietary differences between hadrosaurines and lambeosaurines. Tooth wear evidence further indicates that all forms considered here exhibited some degree of masticatory propaliny. Our findings reveal that tooth morphology and wear exhibit different, but complimentary, dietary signals that combine to support the hypothesis of dietary niche partitioning. The inferred mechanical and dietary patterns appear constant over the 1.5 Myr timespan of the Dinosaur Park Formation megaherbivore chronofauna, despite continual species turnover.

The Functional and Palaeoecological Implications of Tooth Morphology and Wear for the Megaherbivorous Dinosaurs from the Dinosaur Park Formation (Upper Campanian) of Alberta, Canada

PubMed Central

Mallon, Jordan C.; Anderson, Jason S.

2014-01-01

Megaherbivorous dinosaurs were exceptionally diverse on the Late Cretaceous island continent of Laramidia, and a growing body of evidence suggests that this diversity was facilitated by dietary niche partitioning. We test this hypothesis using the fossil megaherbivore assemblage from the Dinosaur Park Formation (upper Campanian) of Alberta as a model. Comparative tooth morphology and wear, including the first use of quantitative dental microwear analysis in the context of Cretaceous palaeosynecology, are used to infer the mechanical properties of the foods these dinosaurs consumed. The phylliform teeth of ankylosaurs were poorly adapted for habitually processing high-fibre plant matter. Nevertheless, ankylosaur diets were likely more varied than traditionally assumed: the relatively large, bladed teeth of nodosaurids would have been better adapted to processing a tougher, more fibrous diet than the smaller, cusp-like teeth of ankylosaurids. Ankylosaur microwear is characterized by a preponderance of pits and scratches, akin to modern mixed feeders, but offers no support for interspecific dietary differences. The shearing tooth batteries of ceratopsids are much better adapted to high-fibre herbivory, attested by their scratch-dominated microwear signature. There is tentative microwear evidence to suggest differences in the feeding habits of centrosaurines and chasmosaurines, but statistical support is not significant. The tooth batteries of hadrosaurids were capable of both shearing and crushing functions, suggestive of a broad dietary range. Their microwear signal overlaps broadly with that of ankylosaurs, and suggests possible dietary differences between hadrosaurines and lambeosaurines. Tooth wear evidence further indicates that all forms considered here exhibited some degree of masticatory propaliny. Our findings reveal that tooth morphology and wear exhibit different, but complimentary, dietary signals that combine to support the hypothesis of dietary niche partitioning. The inferred mechanical and dietary patterns appear constant over the 1.5 Myr timespan of the Dinosaur Park Formation megaherbivore chronofauna, despite continual species turnover. PMID:24918431

Colony types and virulence traits of Legionella feeleii determined by exopolysaccharide materials.

PubMed

Wang, Changle; Saito, Mitsumasa; Ogawa, Midori; Yoshida, Shin-Ichi

2016-05-01

Legionella feeleii is a Gram-negative pathogenic bacterium that causes Pontiac fever and pneumonia in humans. When L. feeleii serogroup 1 (ATCC 35072) was cultured on BCYE agar plates, two types of colonies were observed and exhibited differences in color, opacity and morphology. Since the two colony types are white rugose and brown translucent, they were termed as white rugose L. feeleii (WRLf) and brown translucent L. feeleii (BTLf), respectively. They exhibited different growth capacities in BYE broth in vitro, and it was found that WRLf could transform to BTLf. Under the electron microscope, it was observed that WRLf secreted materials which could be stained with ruthenium red, which was absent in BTLf. When U937 macrophages and HeLa cells were infected with the bacteria, WRLf manifested stronger internalization ability than BTLf. Intracellular growth in murine macrophages and Acanthamoeba cells was affected by the level of initial phagocytosis. WRLf was more resistant to human serum bactericidal action than BTLf. After being inoculated to guinea pigs, both organisms caused fever in the animals. These results suggest that ruthenium red-stained materials secreted in the surroundings may play a crucial role in determining L. feeleii colony morphology and virulence traits. © FEMS 2016. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Evolution of the structure and function of the vertebrate tongue

PubMed Central

Iwasaki, Shin-ichi

2002-01-01

Abstract Studies of the comparative morphology of the tongues of living vertebrates have revealed how variations in the morphology and function of the organ might be related to evolutional events. The tongue, which plays a very important role in food intake by vertebrates, exhibits significant morphological variations that appear to represent adaptation to the current environmental conditions of each respective habitat. This review examines the fundamental importance of morphology in the evolution of the vertebrate tongue, focusing on the origin of the tongue and on the relationship between morphology and environmental conditions. Tongues of various extant vertebrates, including those of amphibians, reptiles, birds and mammals, were analysed in terms of gross anatomy and microanatomy by light microscopy and by scanning and transmission electron microscopy. Comparisons of tongue morphology revealed a relationship between changes in the appearance of the tongue and changes in habitat, from a freshwater environment to a terrestrial environment, as well as a relationship between the extent of keratinization of the lingual epithelium and the transition from a moist or wet environment to a dry environment. The lingual epithelium of amphibians is devoid of keratinization while that of reptilians is keratinized to different extents. Reptiles live in a variety of habitats, from seawater to regions of high temperature and very high or very low humidity. Keratinization of the lingual epithelium is considered to have been acquired concomitantly with the evolution of amniotes. The variations in the extent of keratinization of the lingual epithelium, which is observed between various amniotes, appear to be secondary, reflecting the environmental conditions of different species. PMID:12171472

Evolution of the structure and function of the vertebrate tongue.

PubMed

Iwasaki, Shin-ichi

2002-07-01

Studies of the comparative morphology of the tongues of living vertebrates have revealed how variations in the morphology and function of the organ might be related to evolutional events. The tongue, which plays a very important role in food intake by vertebrates, exhibits significant morphological variations that appear to represent adaptation to the current environmental conditions of each respective habitat. This review examines the fundamental importance of morphology in the evolution of the vertebrate tongue, focusing on the origin of the tongue and on the relationship between morphology and environmental conditions. Tongues of various extant vertebrates, including those of amphibians, reptiles, birds and mammals, were analysed in terms of gross anatomy and microanatomy by light microscopy and by scanning and transmission electron microscopy. Comparisons of tongue morphology revealed a relationship between changes in the appearance of the tongue and changes in habitat, from a freshwater environment to a terrestrial environment, as well as a relationship between the extent of keratinization of the lingual epithelium and the transition from a moist or wet environment to a dry environment. The lingual epithelium of amphibians is devoid of keratinization while that of reptilians is keratinized to different extents. Reptiles live in a variety of habitats, from seawater to regions of high temperature and very high or very low humidity. Keratinization of the lingual epithelium is considered to have been acquired concomitantly with the evolution of amniotes. The variations in the extent of keratinization of the lingual epithelium, which is observed between various amniotes, appear to be secondary, reflecting the environmental conditions of different species.

Process for making whiskers, fibers and flakes of transition metal compounds

DOEpatents

Bamberger, Carlos E.

1992-01-01

A process for making titanium and chromium nitrides of known morphology by reacting potassium titanate and chromium oxide in the gas phase with NH.sub.3. The products exhibit the same morphology as the starting material.

Process for making whiskers, fibers and flakes of transition metal compounds

DOEpatents

Bamberger, C.E.

1992-06-02

A process for making titanium and chromium nitrides of known morphology by reacting potassium titanate and chromium oxide in the gas phase with NH[sub 3]. The products exhibit the same morphology as the starting material.

Turning semicircular canal function on its head: dinosaurs and a novel vestibular analysis.

PubMed

Georgi, Justin A; Sipla, Justin S; Forster, Catherine A

2013-01-01

Previous investigations have correlated vestibular function to locomotion in vertebrates by scaling semicircular duct radius of curvature to body mass. However, this method fails to discriminate bipedal from quadrupedal non-avian dinosaurs. Because they exhibit a broad range of relative head sizes, we use dinosaurs to test the hypothesis that semicircular ducts scale more closely with head size. Comparing the area enclosed by each semicircular canal to estimated body mass and to two different measures of head size, skull length and estimated head mass, reveals significant patterns that corroborate a connection between physical parameters of the head and semicircular canal morphology. Head mass more strongly correlates with anterior semicircular canal size than does body mass and statistically separates bipedal from quadrupedal taxa, with bipeds exhibiting relatively larger canals. This morphologic dichotomy likely reflects adaptations of the vestibular system to stability demands associated with terrestrial locomotion on two, versus four, feet. This new method has implications for reinterpreting previous studies and informing future studies on the connection between locomotion type and vestibular function.

Turning Semicircular Canal Function on Its Head: Dinosaurs and a Novel Vestibular Analysis

PubMed Central

Georgi, Justin A.; Sipla, Justin S.; Forster, Catherine A.

2013-01-01

Previous investigations have correlated vestibular function to locomotion in vertebrates by scaling semicircular duct radius of curvature to body mass. However, this method fails to discriminate bipedal from quadrupedal non-avian dinosaurs. Because they exhibit a broad range of relative head sizes, we use dinosaurs to test the hypothesis that semicircular ducts scale more closely with head size. Comparing the area enclosed by each semicircular canal to estimated body mass and to two different measures of head size, skull length and estimated head mass, reveals significant patterns that corroborate a connection between physical parameters of the head and semicircular canal morphology. Head mass more strongly correlates with anterior semicircular canal size than does body mass and statistically separates bipedal from quadrupedal taxa, with bipeds exhibiting relatively larger canals. This morphologic dichotomy likely reflects adaptations of the vestibular system to stability demands associated with terrestrial locomotion on two, versus four, feet. This new method has implications for reinterpreting previous studies and informing future studies on the connection between locomotion type and vestibular function. PMID:23516495

Age-related changes in glial cells of dopamine midbrain subregions in rhesus monkeys.

PubMed

Kanaan, Nicholas M; Kordower, Jeffrey H; Collier, Timothy J

2010-06-01

Aging remains the strongest risk factor for developing Parkinson's disease (PD), and there is selective vulnerability in midbrain dopamine (DA) neuron degeneration in PD. By tracking normal aging-related changes with an emphasis on regional specificity, factors involved in selective vulnerability and resistance to degeneration can be studied. Towards this end, we sought to determine whether age-related changes in microglia and astrocytes in rhesus monkeys are region-specific, suggestive of involvement in regional differences in vulnerability to degeneration that may be relevant to PD pathogenesis. Gliosis in midbrain DA subregions was measured by estimating glia number using unbiased stereology, assessing fluorescence intensity for proteins upregulated during activation, and rating morphology. With normal aging, microglia exhibited increased staining intensity and a shift to more activated morphologies preferentially in the vulnerable substantia nigra-ventral tier (vtSN). Astrocytes did not exhibit age-related changes consistent with an involvement in regional vulnerability in any measure. Our results suggest advancing age is associated with chronic mild inflammation in the vtSN, which may render these DA neurons more vulnerable to degeneration. Copyright 2008 Elsevier Inc. All rights reserved.

Synthesis of Copper-Antimony-Sulfide Nanocrystals for Solution-Processed Solar Cells.

PubMed

Suehiro, Satoshi; Horita, Keisuke; Yuasa, Masayoshi; Tanaka, Tooru; Fujita, Katsuhiko; Ishiwata, Yoichi; Shimanoe, Kengo; Kida, Tetsuya

2015-08-17

The p-type nanocrystals (NCs) of copper-based chalcogenides, such as CuInSe2 and Cu2ZnSnS4, have attracted increasing attention in photovoltaic applications due to their potential to produce cheap solution-processed solar cells. Herein, we report the synthesis of copper-antimony-sulfide (CAS) NCs with different crystal phases including CuSbS2, Cu3SbS4, and Cu12Sb4S13. In addition, their morphology, crystal phase, and optical properties were characterized using transmission electron microscopy, X-ray diffractometry, UV-vis-near-IR spectroscopy, and photoemission yield spectroscopy. The morphology, crystal phase, and electronic structure were significantly dependent on the chemical composition in the CAS system. Devices were fabricated using particulate films consisting of CAS NCs prepared by spin coating without a high-temperature treatment. The CAS NC-based devices exhibited a diode-like current-voltage characteristic when coupled with an n-type CdS layer. In particular, the CuSbS2 NC devices exhibited photovoltaic responses under simulated sunlight, demonstrating its applicability for use in solution-processed solar cells.

Shrink-induced graphene sensor for alpha-fetoprotein detection with low-cost self-assembly and label-free assay

NASA Astrophysics Data System (ADS)

Sando, Shota; Zhang, Bo; Cui, Tianhong

2017-12-01

Combination of shrink induced nano-composites technique and layer-by-layer (LbL) self-assembled graphene challenges controlling surface morphology. Adjusting shrink temperature achieves tunability on graphene surface morphology on shape memory polymers, and it promises to be an alternative in fields of high-surface-area conductors and molecular detection. In this study, self-assembled graphene on a shrink polymer substrate exhibits nanowrinkles after heating. Induced nanowrinkles on graphene with different shrink temperature shows distinct surface roughness and wettability. As a result, it becomes more hydrophilic with higher shrink temperatures. The tunable wettability promises to be utilized in, for example, microfluidic devices. The graphene on shrink polymer also exhibits capability of being used in sensing applications for pH and alpha-fetoprotein (AFP) detection with advantages of label free and low cost, due to self-assembly technique, easy functionalization, and antigen-antibody reaction on graphene surface. The detection limit of AFP detection is down to 1 pg/mL, and therefore the sensor also has a significant potential for biosensing as it relies on low-cost self-assembly and label-free assay.

Development of CdS Nanostructures by Thermal Decomposition of Aminocaproic Acid-Mixed Cd-Thiourea Complex Precursor: Structural, Optical and Photocatalytic Characterization.

PubMed

Patel, Jayesh D; Mighri, Frej; Ajji, Abdellah; Chaudhuri, Tapas K

2015-04-01

The present work deals with two different CdS nanostructures produced via hydrothermal and solvothermal decompositions of aminocaproic acid (ACA)-mixed Cd-thiourea complex precursor at 175 °C. Both nanostructures were extensively characterized for their structural, morphological and optical properties. The powder X-ray diffraction characterization showed that the two CdS nanostructures present a wurtzite morphology. Scanning electron microscopy and energy-dispersive X-ray characterizations revealed that the hydrothermal decomposition produced well-shaped CdS flowers composed of six dendritic petals, and the solvothermal decomposition produced CdS microspheres with close stoichiometric chemical composition. The UV-vis absorption and photoluminescence spectra of CdS dendritic flowers and microsphere nanostructures showed that both nanostructures present a broad absorption between 200 and 700 nm and exhibit strong green emissions at 576 and 520 nm upon excitations at 290 nm and 260 nm, respectively. The transmission electron microscopy (TEM) and Brunauer-Emmett-Teller (BET) characterizations confirmed that CdS microspheres were mesoporous and were composed of small nanocrystals. A possible growth mechanism in the formation of the CdS nanostructures was proposed based on morphology evolution as a function of the reaction time. Furthermore, the as-synthesized CdS nanostructures were found to exhibit highly efficient photocatalytic activities for the degradation of methyl orange (MeO) and rhodamine B (RhB) dyes.

Fabrication of hierarchical micro-nanotopographies for cell attachment studies.

PubMed

López-Bosque, M J; Tejeda-Montes, E; Cazorla, M; Linacero, J; Atienza, Y; Smith, K H; Lladó, A; Colombelli, J; Engel, E; Mata, A

2013-06-28

We report on the development of micro/nanofabrication processes to create hierarchical surface topographies that expand from 50 nm to microns in size on different materials. Three different approaches (named FIB1, FIB2, and EBL) that combine a variety of techniques such as photolithography, reactive ion etching, focused ion beam lithography, electron beam lithography, and soft lithography were developed, each one providing different advantages and disadvantages. The EBL approach was employed to fabricate substrates comprising channels with features between 200 nm and 10 μm in size on polymethylmethacrylate (PMMA), which were then used to investigate the independent or competitive effects of micro- and nanotopographies on cell adhesion and morphology. Rat mesenchymal stem cells (rMSCs) were cultured on four different substrates including 10 μm wide and 500 nm deep channels separated by 10 μm distances (MICRO), 200 nm wide and 100 nm deep nanochannels separated by 200 nm distances (NANO), their combination in parallel (PARAL), and in a perpendicular direction (PERP). Rat MSCs behaved differently on all tested substrates with a high degree of alignment (as measured by both number of aligned cells and average angle) on both NANO and MICRO. Furthermore, cells exhibited the highest level of alignment on PARAL, suggesting a synergetic effect of the two scales of topographies. On the other hand, cells on PERP exhibited the lowest alignment and a consistent change in morphology over time that seemed to be the result of interactions with both micro- and nanochannels positioned in the perpendicular direction, also suggesting a competitive effect of the topographies.

Shape plasticity in response to water velocity in the freshwater blenny Salaria fluviatilis.

PubMed

Laporte, M; Claude, J; Berrebi, P; Perret, P; Magnan, P

2016-03-01

A non-random association between an environmental factor and a given trait could be explained by directional selection (genetic determinism) and by phenotypic plasticity (environmental determinism). A previous study showed a significant relationship between morphology and water velocity in Salaria fluviatilis that conformed to functional expectations. The objective of this study was to test whether this relationship could be explained by phenotypic plasticity. Salaria fluviatilis from a Corsican stream were placed in four experimental channels with different water velocities (0, 10, 20 and 30 cm s(-1)) to test whether there was a morphological response associated with this environmental factor. After 28 days, fish shape changed in response to water velocity without any significant growth. Fish in higher water velocities exhibited a more slender body shape and longer anal and caudal fins. These results indicate a high degree of morphological plasticity in riverine populations of S. fluviatilis and suggest that the previous relationship between morphology and water velocity observed in the field may largely be due to an environmental determinism. © 2016 The Fisheries Society of the British Isles.

NEW EVIDENCE FOR MORPHOLOGICAL AND GENETIC VARIATION IN THE COSMOPOLITAN COCCOLITHOPHORE EMILIANIA HUXLEYI (PRYMNESIOPHYCEAE) FROM THE COX1b-ATP4 GENES(1).

PubMed

Hagino, Kyoko; Bendif, El Mahdi; Young, Jeremy R; Kogame, Kazuhiro; Probert, Ian; Takano, Yoshihito; Horiguchi, Takeo; de Vargas, Colomban; Okada, Hisatake

2011-10-01

Emiliania huxleyi (Lohmann) W. W. Hay et H. Mohler is a cosmopolitan coccolithophore occurring from tropical to subpolar waters and exhibiting variations in morphology of coccoliths possibly related to environmental conditions. We examined morphological characters of coccoliths and partial mitochondrial sequences of the cytochrome oxidase 1b (cox1b) through adenosine triphosphate synthase 4 (atp4) genes of 39 clonal E. huxleyi strains from the Atlantic and Pacific Oceans, Mediterranean Sea, and their adjacent seas. Based on the morphological study of culture strains by SEM, Type O, a new morphotype characterized by coccoliths with an open central area, was separated from existing morphotypes A, B, B/C, C, R, and var. corona, characterized by coccoliths with central area elements. Molecular phylogenetic studies revealed that E. huxleyi consists of at least two mitochondrial sequence groups with different temperature preferences/tolerances: a cool-water group occurring in subarctic North Atlantic and Pacific and a warm-water group occurring in the subtropical Atlantic and Pacific and in the Mediterranean Sea. © 2011 Phycological Society of America.

Controlled synthesis of BiVO{sub 4} with multiple morphologies via an ethylenediamine-assisted hydrothermal method

DOE Office of Scientific and Technical Information (OSTI.GOV)

Qi, Xuemei, E-mail: qixuemei@shiep.edu.cn; School of Environmental and Chemical Engineering, Shanghai University of Electric Power, Shanghai 200090; Zhu, Xinyuan

2014-11-15

Graphical abstract: BiVO{sub 4} samples with various morphologies were synthesized via a simple ethylenediamine (EN) assisted hydrothermal route. One of the mixed crystal phase with spherical and porous morphology showed excellent photocatalytic activity and about 90% Rhodamine B was degraded after 140 min visible light irradiation. - Highlights: • BiVO{sub 4} samples with various morphologies were synthesized by hydrothermal method. • Ethylenediamine mainly acts as alkaline source to adjust pH values of precursor. • BiVO{sub 4} with spherical morphology has excellent photocatalytic activity. - Abstract: In this work, BiVO{sub 4} particles with different crystal structures and morphologies including hexahedral, sphericalmore » porous and hyperbranched ones were fabricated in the presence of ethylenediamine by hydrothermal process. The as-fabricated samples were well characterized by X-ray diffraction, scanning electron microscopy, Fourier transform infrared spectroscopy, Raman spectroscopy and ultraviolet–visible absorption spectroscopy. The results showed that the morphology and crystal structure of BiVO{sub 4} particles could be well controlled by only changing the ethylenediamine content in the deionized water solution. Photocatalytic activity of the samples was evaluated by the degradation of Rhodamine B under visible-light irradiation. It was shown that BiVO{sub 4} sample with spherical porous morphology and mixed crystal phase exhibited the best photocatalytic performance after optimizing the ethylenediamine content. The best degradation ratio of Rhodamine B could reach about 87% after 140 min visible-light irradiation.« less

Morphological and molecular characterization of Isospora manorinae n. sp. in a yellow-throated miner (Manorina flavigula wayensis) (Gould, 1840).

PubMed

Yang, Rongchang; Brice, Belinda; Jian, Fuchun; Ryan, Una

2016-04-01

A new Isospora (Apicomplexa:Eimeriidae) species is described from a single yellow-throated miner bird (Manorina flavigula) (subspecies M. f. wayensis) in Western Australia. Sporulated oocysts (n = 32) of this isolate are spherical to subspherical, 22.8 (20.3-23.8) × 18.3 (17.7-18.7) μm, with a shape index (length/width) of 1.25 (1.2-1.3); and a smooth and bilayered oocyst wall, 1.3 μm thick (outer layer 0.9 μm, inner 0.4 μm). A polar granule is present, but the micropyle and oocyst residuum are absent. The sporocysts are lemon-shaped, 15.5 (14.6-15.8) × 9.5 (9.5-10.2) μm, with a shape index of 1.6. Stieda and substieda bodies are present, the Stieda body being knob-like and the substieda body being subspherical-shaped. A sporocyst residuum is present and composed of numerous granules of different size scattered among the sporozoites, a spheroid or subspheroid refractile body is present in the sporozoite. Morphologically, the oocysts from this isolate are different from those of all known valid Isospora spp. Molecular analysis was conducted at 3 loci; the 18S and 28S ribosomal RNA and the mitochondrial cytochrome oxidase (COI) gene. At the 18S locus, this new isolate exhibited 99.2% similarity to Isospora gryphoni and three other Isospora spp. Further analysis of a subgroup of 300 bp long 18S sequences (8), including Isospora anthochaerae was conducted. This new isolate grouped in a clade with I. anthochaerae and exhibited 99.3% similarity. At the 28S locus, this new isolate grouped with I. anthochaerae with which it shared 99.1% similarity. At the COI locus, this new isolate exhibited 96.8% similarity to Isospora sp. JCI-2015 from a spectacled warbler (Sylvia conspicillata) in Spain. Further analysis from a subgroup of shorter COI sequences (n = 13) was performed and this new isolate exhibited 99.1% similarity to I. anthochaerae. Based on morphological and molecular data, this isolate is a new species of Isospora, which is named Isospora manorinae n. sp. after its host, the yellow-throated miner (Manorina flavigula wayensis). Crown Copyright © 2016. Published by Elsevier Inc. All rights reserved.

Stimuli Responsive Morphological Changes of Pnipa Polymer Brushes Synthesized on Silicon Substrate

NASA Astrophysics Data System (ADS)

Huda, Muhammad Nurul; Kabir, A. N. M. Hamidul

2013-08-01

High-density polymer brushes were grown from the silicon surface by atom transfer radical polymerization of Poly(N-isopropylacrylamide) (PNIPA) at different polymerization conditions. PNIPA brushes were prepared using Copper (I) Chloride/tris(2-(dimetylamino)ethyl)amine (Me6TREN) as a catalytic system in DMSO at 20°C. Free polymer formed during the brush formation was characterized by gel permeation chromatography. The grafting densities up to 0.52 chains/nm2 were obtained. The layer thickness of polymer brush increases with the increase of conversion of the monomer conversion as well as polymerization time. Atomic force microscopy and air bubble contact angle under pH solution were employed to study the surface morphology, reversible conformational changes of and stimulus-response behavior. PNIPA brushes exhibited a different nanomorphology after treatment with different pH solution. It also revealed a unique reversible wetting behavior with pH. The reversible properties of the PNIPA brushes can be used to regulate the adsorption of the sulfonated PS nanoparticles.

Wetting and drying of liquid on crossed fibers

NASA Astrophysics Data System (ADS)

Sauret, Alban; Bick, Alison D.; Stone, Howard A.; Complex Fluids Group Team

2013-11-01

Fibrous media are common in various engineered systems such as filters, paper or the textile industry. Many of these materials can be described as a network of fibers in which a wetting liquid tends to accumulate at its nodes and changes the bulk properties. Here we study a drop of silicone oil sitting on the simplest element of the array: two rigid crossed fibers. In particular, we investigate experimentally how the structure of the material affects the wetting and drying dynamics of that liquid drop. We first show that the liquid can adopt different shapes from a long liquid column to a drop. The transition between these morphologies depends on the volume of liquid, the tilting angle between the fibers, as well as the fiber radius. The wetting length in the column state can be predicted analytically. Because of these different shapes, the liquid exhibits different drying kinetics, which effects the overall drying time. Our study suggests that shearing a wetted array of fibers, by tuning the liquid morphology, may enhance the drying rate.

Ontogenetic and static allometry in the human face: contrasting Khoisan and Inuit.

PubMed

Freidline, Sarah E; Gunz, Philipp; Hublin, Jean-Jacques

2015-09-01

Regional differences in modern human facial features are present at birth, and ontogenetic allometry contributes to variation in adults. However, details regarding differential rates of growth and timing among regional groups are lacking. We explore ontogenetic and static allometry in a cross-sectional sample spanning Africa, Europe and North America, and evaluate tempo and mode in two regional groups with very different adult facial morphology, the Khoisan and Inuit. Semilandmark geometric morphometric methods, multivariate statistics and growth simulations were used to quantify and compare patterns of facial growth and development. Regional-specific facial morphology develops early in ontogeny. The Inuit has the most distinct morphology and exhibits heterochronic differences in development compared to other regional groups. Allometric patterns differ during early postnatal development, when significant increases in size are coupled with large amounts of shape changes. All regional groups share a common adult static allometric trajectory, which can be attributed to sexual dimorphism, and the corresponding allometric shape changes resemble developmental patterns during later ontogeny. The amount and pattern of growth and development may not be shared between regional groups, indicating that a certain degree of flexibility is allowed for in order to achieve adult size. In early postnatal development the face is less constrained compared to other parts of the cranium allowing for greater evolvability. The early development of region-specific facial features combined with heterochronic differences in timing or rate of growth, reflected in differences in facial size, suggest different patterns of postnatal growth. © 2015 Wiley Periodicals, Inc.

Uniform modeling of bacterial colony patterns with varying nutrient and substrate

NASA Astrophysics Data System (ADS)

Schwarcz, Deborah; Levine, Herbert; Ben-Jacob, Eshel; Ariel, Gil

2016-04-01

Bacteria develop complex patterns depending on growth condition. For example, Bacillus subtilis exhibit five different patterns depending on substrate hardness and nutrient concentration. We present a unified integro-differential model that reproduces the entire experimentally observed morphology diagram at varying nutrient concentrations and substrate hardness. The model allows a comprehensive and quantitative comparison between experimental and numerical variables and parameters, such as colony growth rate, nutrient concentration and diffusion constants. As a result, the role of the different physical mechanisms underlying and regulating the growth of the colony can be evaluated.

A Quantile Regression Approach to Understanding the Relations Between Morphological Awareness, Vocabulary, and Reading Comprehension in Adult Basic Education Students

PubMed Central

Tighe, Elizabeth L.; Schatschneider, Christopher

2015-01-01

The purpose of this study was to investigate the joint and unique contributions of morphological awareness and vocabulary knowledge at five reading comprehension levels in Adult Basic Education (ABE) students. We introduce the statistical technique of multiple quantile regression, which enabled us to assess the predictive utility of morphological awareness and vocabulary knowledge at multiple points (quantiles) along the continuous distribution of reading comprehension. To demonstrate the efficacy of our multiple quantile regression analysis, we compared and contrasted our results with a traditional multiple regression analytic approach. Our results indicated that morphological awareness and vocabulary knowledge accounted for a large portion of the variance (82-95%) in reading comprehension skills across all quantiles. Morphological awareness exhibited the greatest unique predictive ability at lower levels of reading comprehension whereas vocabulary knowledge exhibited the greatest unique predictive ability at higher levels of reading comprehension. These results indicate the utility of using multiple quantile regression to assess trajectories of component skills across multiple levels of reading comprehension. The implications of our findings for ABE programs are discussed. PMID:25351773

Microscopic evolution of dielectric nanoparticles at different calcination temperatures synthesized via sol-gel auto-combustion

DOE Office of Scientific and Technical Information (OSTI.GOV)

Adil, Muhammad, E-mail: muhammadadil86@hotmail.com; Zaid, Hasnah Mohd, E-mail: hasnamz@petronas.com.my; Chuan, Lee Kean, E-mail: lee.kc@petronas.com.my

2015-07-22

Dielectric nano powder synthesis is carried by a simple and fast sol-gel auto-combustion method. The transformation of crystalline phases of as-synthesized nano powders is investigated through the detailed transmission electron microscopy (TEM), revealed the crystallographic alterations and morphological information even at lattice scale. From specific area electron diffraction (SAED) pattern, has specified the d-spacing and corresponding planes supported by the observed lattice fringes. The morphological characterization of nanoparticles is performed through field-emission scanning electron microscopy (FESEM), exhibiting the increment in particle size due to agglomeration with the increase in annealing temperature. Furthermore, EDX pattern has been used to verify themore » formation of nanoparticles by revealing the presence of required elements.« less

[Fenetic analysis of aboriginal and introduced sable (Martes zibellina) populations in Russia].

PubMed

Monakhov, V G

2001-09-01

Using standard and mulivariate statistic methods, an epigenetic character--foramina in fossa condyloidei inferior, FFCI--was studied in sable populations. This character was shown to be most frequent in southeastern populations of the species (Primorye and the Baikal region) while its distribution in the remaining part of the range was polyclinal. The expression of FFCI was directly associated with coat color and longitude, and inversely associated with skull size. This trend was broken by some western populations formed in the 1950s by introduction, which exhibited stable morphological differences with adjacent aboriginal sable populations. Most populations of the species exhibit differences in the manifestation of the character. Frequency of the FFCI manifestation can be used as an additional population characteristic, an associative diagnostic character that shows high discriminating capability in detecting phenogenetic relationships of intraspecific groups.

Left ventricular outflow tract arrhythmias with divergent QRS morphology: mapping of different exits and ablation strategy.

PubMed

Reithmann, Christopher; Fiek, Michael

2018-01-01

Ventricular arrhythmias (VAs) from the left ventricular outflow tract (LVOT) can have multiple exits exhibiting divergent ECG features. In a series of 131 patients with VAs with LVOT origin, 10 patients presented with divergent QRS morphologies. Multisite endo- and epicardial mapping of different exit sites was performed. The earliest ventricular activity of 23 LVOT VAs in 10 patients was detected in the endocardium of the LV in 7 patients, the aortic sinuses of Valsalva (SoV) in 3 patients, the distal coronary sinus in 6 patients, the anterior interventricular vein in 3 patients, and the posterior right ventricular outflow tract (RVOT) in 4 patients. Simultaneous elimination of two divergent QRS morphologies of LVOT VAs by ablation from a single site was achieved in 5 patients (aorto-mitral continuity in 3 patients, SoV and RVOT in each 1 patient) using a mean maximum ablation energy of 46 ± 5 W. Sequential ablation from two or three different sites, including trans-pericardial and distal coronary sinus ablation in each 2 patients, led to elimination of the divergent VA QRS morphologies in the other 5 patients. During the follow-up of 28 ± 29 months, 4 of the 10 patients had recurrence of at least one LVOT VA. A 43-year-old patient with muscular dystrophy Curschmann-Steinert had recurrence of sustained LVOT VTs and died of sudden cardiac death. Multisite mapping of different exit sites of LVOT VAs can guide ablation of intramural foci but the recurrence rate after initially successful ablation was high.

Variability and similarities in the structural properties of two related Laminaria kelp species

NASA Astrophysics Data System (ADS)

Henry, Pierre-Yves

2018-01-01

Kelps of the genus Laminaria have long been studied and shown to exhibit a seasonal shift in growth and morphology, as nutrients and light levels change during the year. However, the variation of kelp biomechanical properties has been little explored despite the importance of these properties for the interaction of kelp with the flow. Previous research showed that aging does influence the algae biomechanical properties, so this study further investigates the variability of kelp biomechanical properties and morphological characteristics at a given site as a function of the season (growth phase), species, and different kelp parts. Mechanical parameters and morphological characteristics were measured on kelps sampled in winter and summer, and DNA sequencing was used to identify the two related species, L. digitata and L. hyperborea. Descriptive statistics and statistical analysis were used to detect trends in the modulation of kelp mechanical design. Although two distinct species were identified, only minor structural differences were observed between them. The biomechanical properties varied significantly along the kelp, and significant seasonal shifts occurred at the blade level, in relation to the different morphological changes during blade renewal. In general, the variations of the structural properties were mostly linked to the blade growth activity. The absence of significant variation in the mechanical design of the two species highlights the significance of the adaptation to the same local environmental conditions, this adaptation being a key process in vegetation-flow interactions and having implications on the interaction between kelp and hydrodynamics.

Sulfur Nanoparticles with Novel Morphologies Coupled with Brain-Targeting Peptides RVG as a New Type of Inhibitor Against Metal-Induced Aβ Aggregation.

PubMed

Sun, Jing; Xie, Wenjie; Zhu, Xufeng; Xu, Mengmeng; Liu, Jie

2018-04-18

Functionalized nanomaterials, which have been applied widely to inhibit amyloid-β protein (Aβ) aggregation, show enormous potential in the field of prevention and treatment of Alzheimer's disease (AD). A significant body of data has demonstrated that the morphology and size of nanomaterials have remarkable effects on their biological behaviors. In this work, we proposed and designed three kinds of brain-targeting sulfur nanoparticles (RVG@Met@SNPs) with novel morphologies (volute-like, tadpole-like, and sphere-like) and investigated the effect of different RVG@Met@SNPs on Aβ-Cu 2+ complex aggregation and their corresponding neurotoxicity. Among them, the sphere-like nanoparticles (RVG@Met@SS) exhibited the most effective inhibitory activity, due to their unique mini size effect, and they reduced 61.6% the Aβ-Cu 2+ complex aggregation and increased 92.4% SH-SY5Y cell viability in a dose of 10 μg/mL. In vitro and in vivo, the abilities of different morphologies of RVG@Met@SNPs to cross the blood-brain barrier (BBB) and target brain parenchymal cells were significantly different. Moreover, improvements in learning disability and cognitive loss were shown in the transgenic AD mice model using the Morris water maze test after multiple doses of RVG@Met@SNPs treatment. In general, the purpose of this research is to develop a biological application of sulfur nanoparticles and to provide a novel functionalized nanomaterial to treat AD.

Role of Intramolecular Aromatic π-π Interactions in the Self-Assembly of Di-l-Phenylalanine Dipeptide Driven by Intermolecular Interactions: Effect of Alanine Substitution.

PubMed

Reddy, Samala Murali Mohan; Shanmugam, Ganesh

2016-09-19

Although the role of intermolecular aromatic π-π interactions in the self-assembly of di-l-phenylalanine (l-Phe-l-Phe, FF), a peptide that is known for hierarchical structure, is well established, the influence of intramolecular π-π interactions on the morphology of the self-assembled structure of FF has not been studied. Herein, the role of intramolecular aromatic π-π interactions is investigated for FF and analogous alanine (Ala)-containing dipeptides, namely, l-Phe-l-Ala (FA) and l-Ala-l-Phe (AF). The results reveal that these dipeptides not only form self-assemblies, but also exhibit remarkable differences in structural morphology. The morphological differences between FF and the analogues indicate the importance of intramolecular π-π interactions, and the structural difference between FA and AF demonstrates the crucial role of the nature of intramolecular side-chain interactions (aromatic-aliphatic or aliphatic-aromatic), in addition to intermolecular interactions, in deciding the final morphology of the self-assembled structure. The current results emphasise that intramolecular aromatic π-π interaction may not be essential to induce self-assembly in smaller peptides, and π (aromatic)-alkyl or alkyl-π (aromatic) interactions may be sufficient. This work also illustrates the versatility of aromatic and a combination of aromatic and aliphatic residues in dipeptides in the formation of structurally diverse self-assembled structures. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Corallite skeletal morphological variation in Hawaiian Porites lobata

NASA Astrophysics Data System (ADS)

Tisthammer, Kaho H.; Richmond, Robert H.

2018-06-01

Due to their high morphological plasticity and complex evolutionary history, the species boundaries of many reef-building corals are poorly understood. The skeletal structures of corals have traditionally been used for species identification, but these structures can be highly variable, and currently we lack knowledge regarding the extent of morphological variation within species. Porites species are notorious for their taxonomic difficulties, both morphologically and genetically, and currently there are several unresolved species complexes in the Pacific. Despite its ubiquitous presence and broad use in coral research, Porites lobata belongs to one such unresolved species complex. To understand the degree of intraspecific variation in skeletal morphology, 120 corallites from the Hawaiian P. lobata were examined. A subset of samples from two genetically differentiated populations from contrasting high- and low-stress environments in Maunalua Bay, Hawaii, were then quantitatively analyzed using multivariate morphometrics. Our observations revealed high intraspecific variation in corallite morphology, as well as significant morphological differences between the two populations of P. lobata. Additionally, significant correlation was found between the morphological and genetic distances calculated from approximately 18,000 loci generated from restriction site-associated DNA sequencing. The unique morphological characters observed from the genetically differentiated population under environmental stress suggest that these characters may have adaptive values, but how such traits relate to fitness and how much plasticity they can exhibit remain to be determined by future studies. Relatively simple morphometric analyses used in our study can be useful in clarifying the existing ambiguity in skeletal architecture, thus contributing to resolving species issues in corals.

Influence of Different Aluminum Sources on the NH3 Gas-Sensing Properties of ZnO Thin Films

NASA Astrophysics Data System (ADS)

Ozutok, Fatma; Karaduman, Irmak; Demiri, Sani; Acar, Selim

2018-02-01

Herein we report Al-doped ZnO films (AZO) deposited on the ZnO seed layer by chemical bath deposition method. Al powder, Al oxide and Al chloride were used as sources for the deposition process and investigated for their different effects on the NH3 gas-sensing performance. The morphological and microstructural properties were investigated by employing x-ray powder diffraction, scanning electron microscopy analysis and energy-dispersive x-ray spectroscopy. The characterization studies showed that the AZO thin films are crystalline and exhibit a hexagonal wurtzite structure. Ammonia (NH3) gas-sensing measurements of AZO films were performed at different concentration levels and different operation temperatures from 50°C to 210°C. The sample based on powder-Al source showed a higher response, selectivity and short response/recovery time than the remaining samples. The powder Al sample exhibited 33% response to 10-ppm ammonia gas at 190°C, confirming a strong dependence on the dopant source type.

Motoneuron axon pathfinding errors in zebrafish: Differential effects related to concentration and timing of nicotine exposure

PubMed Central

Menelaou, Evdokia; Paul, Latoya T.; Perera, Surangi N.; Svoboda, Kurt R.

2015-01-01

Nicotine exposure during embryonic stages of development can affect many neurodevelopmental processes. In the developing zebrafish, exposure to nicotine was reported to cause axonal pathfinding errors in the later born secondary motoneurons (SMN). These alterations in SMN axon morphology coincided with muscle degeneration at high nicotine concentrations (15–30µM). Previous work showed that the paralytic mutant zebrafish known as sofa potato, exhibited nicotine-induced effects onto SMN axons at these high concentrations but in the absence of any muscle deficits, indicating that pathfinding errors could occur independent of muscle effects. In this study, we used varying concentrations of nicotine at different developmental windows of exposure to specifically isolate its effects onto subpopulations of motoneuron axons. We found that nicotine exposure can affect SMN axon morphology in a dose-dependent manner. At low concentrations of nicotine, SMN axons exhibited pathfinding errors, in the absence of any nicotine-induced muscle abnormalities. Moreover, the nicotine exposure paradigms used affected the 3 subpopulations of SMN axons differently, but the dorsal projecting SMN axons were primarily affected. We then identified morphologically distinct pathfinding errors that best described the nicotine-induced effects on dorsal projecting SMN axons. To test whether SMN pathfinding was potentially influenced by alterations in the early born primary motoneuron (PMN), we performed dual labeling studies, where both PMN and SMN axons were simultaneously labeled with antibodies. We show that only a subset of the SMN axon pathfinding errors coincided with abnormal PMN axonal targeting in nicotine-exposed zebrafish. We conclude that nicotine exposure can exert differential effects depending on the levels of nicotine and developmental exposure window. PMID:25668718

Shape Variation in Aterian Tanged Tools and the Origins of Projectile Technology: A Morphometric Perspective on Stone Tool Function

PubMed Central

Iovita, Radu

2011-01-01

Background Recent findings suggest that the North African Middle Stone Age technocomplex known as the Aterian is both much older than previously assumed, and certainly associated with fossils exhibiting anatomically modern human morphology and behavior. The Aterian is defined by the presence of ‘tanged’ or ‘stemmed’ tools, which have been widely assumed to be among the earliest projectile weapon tips. The present study systematically investigates morphological variation in a large sample of Aterian tools to test the hypothesis that these tools were hafted and/or used as projectile weapons. Methodology/Principal Findings Both classical morphometrics and Elliptical Fourier Analysis of tool outlines are used to show that the shape variation in the sample exhibits size-dependent patterns consistent with a reduction of the tools from the tip down, with the tang remaining intact. Additionally, the process of reduction led to increasing side-to-side asymmetries as the tools got smaller. Finally, a comparison of shape-change trajectories between Aterian tools and Late Paleolithic arrowheads from the North German site of Stellmoor reveal significant differences in terms of the amount and location of the variation. Conclusions/Significance The patterns of size-dependent shape variation strongly support the functional hypothesis of Aterian tools as hafted knives or scrapers with alternating active edges, rather than as weapon tips. Nevertheless, the same morphological patterns are interpreted as one of the earliest evidences for a hafting modification, and for the successful combination of different raw materials (haft and stone tip) into one implement, in itself an important achievement in the evolution of hominin technologies. PMID:22216161

Morphological and structural plasticity of grassland species in response to a gradient in saline-sodic soils.

PubMed

Huang, Y; Song, Y; Li, G; Drake, P L; Zheng, W; Li, Z; Zhou, D

2015-11-01

The abundance and distribution of species can be ascribed to both environmental heterogeneity and stress tolerance, with the latter measure sometimes associated with phenotypic plasticity. Although phenotypic plasticity varies predictably in response to common forms of stress, we lack a mechanistic understanding of the response of species to high saline-sodic soils. We compared the phenotypic plasticity of three pairs of high and low saline-sodic tolerant congeners from the families Poaceae (Leymus chinensis versus L. secalinus), Fabaceae (Lespedeza davurica versus L. bicolor) and Asteraceae (Artemisia mongolica versus A. sieversiana) in a controlled pot experiment in the Songnen grassland, China. The low tolerant species, L. secalinus and A. sieversiana exhibited higher plasticity in response to soil salinity and sodicity than their paired congeners. Highly tolerant species, L. chinensis and A. mongolica, had higher values for several important morphological traits, such as shoot length and total biomass under the high saline-sodic soil treatment than their paired congeners. In contrast, congeners from the family Fabaceae, L. davurica and L. bicolor, did not exhibit significantly different plasticity in response to soil salinity and sodicity. All species held a constant reproductive effort in response to saline-sodic soil stress. The different responses between low and high tolerant species offer an explanation for the distribution patterns of these species in the Songnen grassland. Highly tolerant species showed less morphological plasticity over a range of saline-sodic conditions than their paired congeners, which may manifest as an inability to compete with co-occurring species in locations where saline-sodic soils are absent. © 2015 German Botanical Society and The Royal Botanical Society of the Netherlands.

NiCo2O4 particles with diamond-shaped hexahedron structure for high-performance supercapacitors

NASA Astrophysics Data System (ADS)

Li, Yanfang; Hou, Xiaojuan; Zhang, Zengxing; Hai, Zhenyin; Xu, Hongyan; Cui, Danfeng; Zhuiykov, Serge; Xue, Chenyang

2018-04-01

Nickel cobalt oxide (NiCo2O4) particles with a diamond-shaped hexahedral porous sheet structure are successfully synthesized by a facile hydrothermal method, followed by calcination in one step. NiCo2O4-I and NiCo2O4-II particles are prepared using the same method with different contents of urea (CO(NH2)2) and ammonium fluoride (NH4F). The different morphologies of the NiCo2O4-I and NiCo2O4-II particles illustrate that CO(NH2)2 and NH4F play an important role in crystal growth. To verify the influence of NH4F and CO(NH2)2 on the morphology of the NiCo2O4 particles, the theory of crystal growth morphology is analyzed. The electrochemical measurements show that NiCo2O4 particles exhibit a high specific capacitance. At a current density of 1.0 mA cm-2, the mass specific capacitances of the NiCo2O4-I and NiCo2O4-II electrodes are 690.75 and 1710.9 F g-1, respectively, in a 6 M KOH aqueous electrolyte. The specific capacitances of the NiCo2O4-I and NiCo2O4-II electrodes remain ∼95.95% and ∼70.58% of the initial capacitance values after 5000 cycles, respectively. According to the two-electrode test, the NiCo2O4-II//AC asymmetric electrodes exhibited an ultrahigh energy density of 64.67 Wh kg-1 at the power density of 12 kW kg-1, demonstrating its excellent application potential as an electrode material for supercapacitors.

Metabolic and morphological differences between rapidly proliferating cancerous and normal breast epithelial cells.

PubMed

Meadows, Adam L; Kong, Becky; Berdichevsky, Marina; Roy, Siddhartha; Rosiva, Rosiva; Blanch, Harvey W; Clark, Douglas S

2008-01-01

The metabolic and morphological characteristics of two human epithelial breast cell populations--MCF7 cells, a cancerous cell line, and 48R human mammary epithelial cells (48R HMECs), a noncancerous, finite lifespan cell strain--were compared at identical growth rates. Both cell types were induced to grow rapidly in nutrient-rich media containing 13C-labeled glucose, and the isotopic enrichment of cellular metabolites was quantified to calculate metabolic fluxes in key pathways. Despite their similar growth rates, the cells exhibited distinctly different metabolic and morphological profiles. MCF7 cells have an 80% smaller exposed surface area and contain 26% less protein per cell than the 48R cells. Surprisingly, rapidly proliferating 48R cells exhibited a 225% higher per-cell glucose consumption rate, a 250% higher per-cell lactate production rate, and a nearly identical per-cell glutamine consumption rate relative to the cancer cell line. However, when fluxes were considered on the basis of exposed area, the cancer cells were observed to have higher glucose, lactate, and glutamine fluxes, demonstrating superior transport capabilities per unit area of cell membrane. MCF7 cells also consumed amino acids at rates much higher than are generally required for protein synthesis, whereas 48R cells generally did not. Pentose phosphate pathway activity was higher in MCF7 cells, and the flux of glutamine to glutamate was less reversible. Energy efficiency was significantly higher in MCF7 cells, as a result of a combination of their smaller size and greater reliance on the TCA cycle than the 48R cells. These observations support evolutionary models of cancer cell metabolism and suggest targets for metabolic drugs in metastatic breast cancers.

Species variation in the degree of sex differences in brain and behaviour related to birdsong: adaptations and constraints.

PubMed

Ball, Gregory F

2016-02-19

The song-control system, a neural circuit that controls the learning and production of birdsong, provided the first example in vertebrates of prominent macro-morphological sex differences in the brain. Forebrain nuclei HVC, robust nucleus of the arcopallium (RA) and area X all exhibit prominent male-biased sex differences in volume in zebra finches and canaries. Subsequent studies compared species that exhibited different degrees of a sex difference in song behaviour and revealed an overall positive correlation between male biases in song behaviour and male biases in the volume of the song nuclei. However, several exceptions have been described in which male biases in HVC and RA are observed even though song behaviour is equal or even female-biased. Other phenotypic measures exhibit lability in both sexes. In the duetting plain-tailed wren (Pheugopedius euophrys), males and females have auditory cells in the song system that are tuned to the joint song the two sexes produce rather than just male or female components. These findings suggest that there may be constraints on the adaptive response of the song system to ecological conditions as assessed by nucleus volume but that other critical variables regulating song can respond so that each sex can modify its song behaviour as needed. © 2016 The Author(s).

Synthetic Design of Polysulfone Membranes: Morphological Effect on Property and Performance in Flow Batteries

NASA Astrophysics Data System (ADS)

Gindt, Brandon

This dissertation outlines a novel path towards improved understanding and function of proton exchange membranes (PEMs) for redox flow batteries, a large-scale battery storage device. This research uses synthetic methods and nanotechnology through two different approaches to prepare tailored polymer membranes: 1) Ion exchange membranes with enhanced chemical structures to promote membrane morphology on the nano-scale were prepared. Specifically, functional polysulfones (PSUs) were synthesized from different pre-sulfonated monomers. These PSUs have controlled placement and content of unique sulfonic acid moieties. PEMs were fabricated and characterized. The new PEMs showed desirable physical properties and performance in a vanadium redox flow battery (VRFB) cell. 2) Nanoporous PSU membranes were fabricated via post-hydrolysis of polylactide (PLA) from PLA-PSU-PLA triblock copolymer membranes. The controlled morphology and pore size of the resulting nanoporous membranes were evaluated by different microscopy and scattering techniques to understand structure-property relationships. Further, the resulting nanopore surface was chemically modified with sulfonic acid moieties. Membranes were analyzed and evaluated as separators for a VRFB. The chemically modified nanoporous PEMs exhibited unique behavior with respect to their ion conductivity when exposed to solutions of increasing acid concentration. In addition, the hierarchical micro-nanoporous membranes developed further showed promising structure and properties.

A new high-resolution 3-D quantitative method for analysing small morphological features: an example using a Cambrian trilobite.

PubMed

Esteve, Jorge; Zhao, Yuan-Long; Maté-González, Miguel Ángel; Gómez-Heras, Miguel; Peng, Jin

2018-02-12

Taphonomic processes play an important role in the preservation of small morphological features such as granulation or pits. However, the assessment of these features may face the issue of the small size of the specimens and, sometimes, the destructiveness of these analyses, which makes impossible carrying them out in singular specimen, such as holotypes or lectotypes. This paper takes a new approach to analysing small-morphological features, by using an optical surface roughness (OSR) meter to create a high-resolution three-dimensional digital-elevation model (DEM). This non-destructive technique allows analysing quantitatively the DEM using geometric morphometric methods (GMM). We created a number of DEMs from three populations putatively belonging to the same species of trilobite (Oryctocephalus indicus) that present the same cranidial outline, but differ in the presence or absence of the second and third transglabellar furrows. Profile analysis of the DEMs demonstrate that all three populations show similar preservation variation in the glabellar furrows and lobes. The GMM shows that all populations exhibit the same range of variation. Differences in preservation are a consequence of different degrees of cementation and rates of dissolution. Fast cementation enhances the preservation of glabellar furrows and lobes, while fast dissolution hampers preservation of the same structures.

Effects of smoking on taste: assessment with contact endoscopy and taste strips.

PubMed

Konstantinidis, Iordanis; Chatziavramidis, Angelos; Printza, Athanasia; Metaxas, Spyros; Constantinidis, Jannis

2010-10-01

This study aims to compare the taste function between smokers and nonsmokers with clinical testing, subjective ratings, and contact endoscopy of the tongue. Cross-sectional survey. Data were collected from 38 smokers (mean age 37 years; 25 female, 23 male) and 34 nonsmokers (mean age 33.5 years; 18 female, 16 male). The parameters assessed were the number of fungiform papillae per square centimeter in a noncontact way and their morphology (surface, capillary vessels) by contact endoscopy. The morphology of the filiform papillae has also been assessed. In addition, clinical testing of gustatory function was performed by means of taste strips and subjective intensity ratings of natural taste stimuli. No significant difference was found in clinical testing and intensity ratings between the two study groups. A trend toward significance was found in taste strip results for decreased bitter taste in heavy smokers (P = .06). The number and the size of fungiform papillae did not significantly differ between the study groups. No sex-related differences were observed. Smokers exhibited significantly more keratin structures on the fungiform papillae surface, less tortuous capillary vessels, and a significant distortion of their filiform papillae. Taste function presents significant resistance to smoking, although changes in morphology of fungiform and filiform papillae have been observed especially in heavy smokers. Laryngoscope, 2010.

Jaw lever analysis of Hawaiian gobioid stream fishes: a simulation study of morphological diversity and functional performance.

PubMed

Maie, Takashi; Schoenfuss, Heiko L; Blob, Richard W

2009-08-01

Differences in feeding behavior and performance among the five native Hawaiian gobioid stream fishes (Sicyopterus stimpsoni, Lentipes concolor, Awaous guamensis, Stenogobius hawaiiensis, and Eleotris sandwicensis) have been proposed based on the skeletal anatomy of their jaws and dietary specialization. However, performance of the feeding apparatus likely depends on the proportions and configurations of the jaw muscles and the arrangement of the jaw skeleton. We used a published mathematical model of muscle function to evaluate potential differences in jaw closing performance and their correlations with morphology among these species. For example, high output force calculated for the adductor mandibulae muscles (A2 and A3) of both A. guamensis and E. sandwicensis matched expectations based on the morphology of these species because these muscles are larger than in the other species. In contrast, Stenogobius hawaiiensis exhibited an alternative morphological strategy for achieving high relative output forces of both A2 and A3, in which the placement and configuration of the muscles conveyed high mechanical advantage despite only moderate cross-sectional areas. These differing anatomical pathways to similar functional performance suggest a pattern of many-to-one mapping of morphology to performance. In addition, a functional differentiation between A2 and A3 was evident for all species, in which A2 was better suited for producing forceful jaw closing and A3 for rapid jaw closing. Thus, the diversity of feeding performance of Hawaiian stream gobies seems to reflect a maintenance of functional breadth through the retention of some primitive traits in combination with novel functional capacities in several species. (c) 2009 Wiley-Liss, Inc.

Morphological similarity and ecological overlap in two rotifer species.

PubMed

Gabaldón, Carmen; Montero-Pau, Javier; Serra, Manuel; Carmona, María José

2013-01-01

Co-occurrence of cryptic species raises theoretically relevant questions regarding their coexistence and ecological similarity. Given their great morphological similitude and close phylogenetic relationship (i.e., niche retention), these species will have similar ecological requirements and are expected to have strong competitive interactions. This raises the problem of finding the mechanisms that may explain the coexistence of cryptic species and challenges the conventional view of coexistence based on niche differentiation. The cryptic species complex of the rotifer Brachionus plicatilis is an excellent model to study these questions and to test hypotheses regarding ecological differentiation. Rotifer species within this complex are filtering zooplankters commonly found inhabiting the same ponds across the Iberian Peninsula and exhibit an extremely similar morphology-some of them being even virtually identical. Here, we explore whether subtle differences in body size and morphology translate into ecological differentiation by comparing two extremely morphologically similar species belonging to this complex: B. plicatilis and B. manjavacas. We focus on three key ecological features related to body size: (1) functional response, expressed by clearance rates; (2) tolerance to starvation, measured by growth and reproduction; and (3) vulnerability to copepod predation, measured by the number of preyed upon neonates. No major differences between B. plicatilis and B. manjavacas were found in the response to these features. Our results demonstrate the existence of a substantial niche overlap, suggesting that the subtle size differences between these two cryptic species are not sufficient to explain their coexistence. This lack of evidence for ecological differentiation in the studied biotic niche features is in agreement with the phylogenetic limiting similarity hypothesis but requires a mechanistic explanation of the coexistence of these species not based on differentiation related to biotic niche axes.

Controlled fabrication of PANI/CNF hybrid films: molecular interaction induced various micromorphologies and electrochemical properties.

PubMed

Xu, Guiheng; Xu, Dongdong; Zhang, Jianan; Wang, Kaixi; Chen, Zhimin; Chen, Jiafu; Xu, Qun

2013-12-01

In this paper, a facile and efficient method is reported to prepare polyaniline/carbon nanofiber (PANI/CNF) hybrid films by in situ chemical polymerization of aniline. The various morphologies and microstructures of PANI/CNF hybrid films can be controlled by adjusting the concentration of aniline and different acids as the protonation reagent, and the formation mechanism is illustrated in this study. The surface morphologies and chemical structure of the PANI/CNF hybrid films are characterized by scanning electron microscope (SEM), transmission electron microscope (TEM), water contact angle (CA), FT-IR, Raman, and UV-vis spectrophotometers. The different morphology of uniformly coated, twist-tangled, and needle-like PANI built on CNF films are obtained by using HCl, H2SO4, and HClO4 as protonation reagent and the obtained hybrid films are labeled as PANI/CNF-f1, PANI/CNF-f2, and PANI/CNF-f3, respectively. We demonstrated that the different protonation reagent has the determined effect on the surface properties of the obtained hybrid films that can transfer from hydrophilic to hydrophobic. Besides, the various morphologies of PANI play an important role in their electrochemical properties. PANI/CNF-f3 exhibits higher specific capacitance and better stability than that of the PANI/CNF-f1 and PANI/CNF-f2. Considering its unique needle-like structure, this work is a proof of concept that micro-structure and morphology can determine the macro-properties. And this study supplies a facile method to fabricate PANI/CNF hybrid films that can be used as electrode materials in supercapacitors. Copyright © 2013 Elsevier Inc. All rights reserved.

The antagonistic modulation of Arp2/3 activity by N-WASP, WAVE2 and PICK1 defines dynamic changes in astrocyte morphology.

PubMed

Murk, Kai; Blanco Suarez, Elena M; Cockbill, Louisa M R; Banks, Paul; Hanley, Jonathan G

2013-09-01

Astrocytes exhibit a complex, branched morphology, allowing them to functionally interact with numerous blood vessels, neighboring glial processes and neuronal elements, including synapses. They also respond to central nervous system (CNS) injury by a process known as astrogliosis, which involves morphological changes, including cell body hypertrophy and thickening of major processes. Following severe injury, astrocytes exhibit drastically reduced morphological complexity and collectively form a glial scar. The mechanistic details behind these morphological changes are unknown. Here, we investigate the regulation of the actin-nucleating Arp2/3 complex in controlling dynamic changes in astrocyte morphology. In contrast to other cell types, Arp2/3 inhibition drives the rapid expansion of astrocyte cell bodies and major processes. This intervention results in a reduced morphological complexity of astrocytes in both dissociated culture and in brain slices. We show that this expansion requires functional myosin II downstream of ROCK and RhoA. Knockdown of the Arp2/3 subunit Arp3 or the Arp2/3 activator N-WASP by siRNA also results in cell body expansion and reduced morphological complexity, whereas depleting WAVE2 specifically reduces the branching complexity of astrocyte processes. By contrast, knockdown of the Arp2/3 inhibitor PICK1 increases astrocyte branching complexity. Furthermore, astrocyte expansion induced by ischemic conditions is delayed by PICK1 knockdown or N-WASP overexpression. Our findings identify a new morphological outcome for Arp2/3 activation in restricting rather than promoting outwards movement of the plasma membrane in astrocytes. The Arp2/3 regulators PICK1, and N-WASP and WAVE2 function antagonistically to control the complexity of astrocyte branched morphology, and this mechanism underlies the morphological changes seen in astrocytes during their response to pathological insult.

Anomalous single-subject based morphological cortical networks in drug-naive, first-episode major depressive disorder.

PubMed

Chen, Taolin; Kendrick, Keith M; Wang, Jinhui; Wu, Min; Li, Kaiming; Huang, Xiaoqi; Luo, Yuejia; Lui, Su; Sweeney, John A; Gong, Qiyong

2017-05-01

Major depressive disorder (MDD) has been associated with disruptions in the topological organization of brain morphological networks in group-level data. Such disruptions have not yet been identified in single-patients, which is needed to show relations with symptom severity and to evaluate their potential as biomarkers for illness. To address this issue, we conducted a cross-sectional structural brain network study of 33 treatment-naive, first-episode MDD patients and 33 age-, gender-, and education-matched healthy controls (HCs). Weighted graph-theory based network models were used to characterize the topological organization of brain networks between the two groups. Compared with HCs, MDD patients exhibited lower normalized global efficiency and higher modularity in their whole-brain morphological networks, suggesting impaired integration and increased segregation of morphological brain networks in the patients. Locally, MDD patients exhibited lower efficiency in anatomic organization for transferring information predominantly in default-mode regions including the hippocampus, parahippocampal gyrus, precuneus and superior parietal lobule, and higher efficiency in the insula, calcarine and posterior cingulate cortex, and in the cerebellum. Morphological connectivity comparisons revealed two subnetworks that exhibited higher connectivity strength in MDD mainly involving neocortex-striatum-thalamus-cerebellum and thalamo-hippocampal circuitry. MDD-related alterations correlated with symptom severity and differentiated individuals with MDD from HCs with a sensitivity of 87.9% and specificity of 81.8%. Our findings indicate that single subject grey matter morphological networks are often disrupted in clinically relevant ways in treatment-naive, first episode MDD patients. Circuit-specific changes in brain anatomic network organization suggest alterations in the efficiency of information transfer within particular brain networks in MDD. Hum Brain Mapp 38:2482-2494, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

Molecular interactions in self-assembled nano-structures of chitosan-sodium alginate based polyelectrolyte complexes.

PubMed

Wasupalli, Geeta Kumari; Verma, Devendra

2018-03-16

We report here the self-assembled structures of polyelectrolyte complexes (PECs) of polyanionic sodium alginate with the polycationic chitosan at room temperature. The PECs prepared at different pH values exhibited two distinct morphologies. The chitosan-alginate PECs self-assembled into the fibrous structure in a low pH range of pH3 to 7. The PECs obtained at high pH series around pH8 and above resulted in the formation of colloidal nanoparticles in the range of 120±9.48nm to 46.02±16.66nm. The zeta potential measurement showed that PECs prepared at lower pH (pH<6) exhibited nearly neutral surface charge, whereas PECs prepared at higher pH than 6 exhibited highly negative surface charge. The molecular interactions in nano-colloids and fibers were evaluated using FTIR analysis. The results attest that the ionic state of the chitosan and alginate plays an important role controlling the morphologies of the PECS. The present study has identified the enormous potential of the polyelectrolytes complexes to exploit shape by the alteration of ionic strength. These findings might be useful in the development of novel biomaterial. The produced fibers and nanocolloids could be applied as a biomaterial for tissue engineering and drug delivery. Copyright © 2017. Published by Elsevier B.V.

Morphological and electromechanical characterization of ionic liquid/Nafion polymer composites

NASA Astrophysics Data System (ADS)

Bennett, Matthew; Leo, Donald

2005-05-01

Ionic liquids have shown promise as replacements for water in ionic polymer transducers. Ionic liquids are non-volatile and have a larger electrochemical stability window than water. Therefore, transducers employing ionic liquids can be operated for long periods of time in air and can be actuated with higher voltages. Furthermore, transducers based on ionic liquids do not exhibit the characteristic back relaxation that is common with water-swollen materials. However, the physics of transduction in the ionic liquid-swollen materials is not well understood. In this paper, the morphology of Nafion/ionic liquid composites is characterized using small-angle X-ray scattering (SAXS). The electromechanical transduction behavior of the composites is also investigated. For this testing, five different counterions and two ionic liquids are used. The results reveal that both the morphology and transduction performance of the composites is affected by the identity of the ionic liquid, the cation, and the swelling level of ionic liquid within the membrane. Specifically, speed of response is found to be lower for the membranes that were exchanged with the smaller lithium and potassium ions. The response speed is also found to increase with increased content of ionic liquid. Furthermore, for the two ionic liquids studied, the actuators swollen with the less viscous ionic liquid exhibited a slower response. The slower speed of response corresponds to less contrast between the ionically conductive phase and the inert phase of the polymer. This suggests that disruption of the clustered morphology in the ionic liquid-swollen membranes as compared to water-swollen membranes attenuates ion mobility within the polymer. This attenuation is attributed to swelling of the non-conductive phase by the ionic liquids.

Lateral Semicircular Canal Asymmetry in Idiopathic Scoliosis: An Early Link between Biomechanical, Hormonal and Neurosensory Theories?

PubMed Central

Hitier, Martin; Hamon, Michèle; Denise, Pierre; Lacoudre, Julien; Thenint, Marie-Aude; Mallet, Jean-François; Moreau, Sylvain; Quarck, Gaëlle

2015-01-01

Introduction Despite its high incidence and severe morbidity, the physiopathogenesis of adolescent idiopathic scoliosis (AIS) is still unknown. Here, we looked for early anomalies in AIS which are likely to be the cause of spinal deformity and could also be targeted by early treatments. We focused on the vestibular system, which is suspected of acting in AIS pathogenesis and which exhibits an end organ with size and shape fixed before birth. We hypothesize that, in adolescents with idiopathic scoliosis, vestibular morphological anomalies were already present at birth and could possibly have caused other abnormalities. Materials and Methods The vestibular organ of 18 adolescents with AIS and 9 controls were evaluated with MRI in a prospective case controlled study. We studied lateral semicircular canal orientation and the three semicircular canal positions relative to the midline. Lateral semicircular canal function was also evaluated by vestibulonystagmography after bithermal caloric stimulation. Results The left lateral semicircular canal was more vertical and further from the midline in AIS (p = 0.01) and these two parameters were highly correlated (r = -0.6; p = 0.02). These morphological anomalies were associated with functional anomalies in AIS (lower excitability, higher canal paresis), but were not significantly different from controls (p>0.05). Conclusion Adolescents with idiopathic scoliosis exhibit morphological vestibular asymmetry, probably determined well before birth. Since the vestibular system influences the vestibulospinal pathway, the hypothalamus, and the cerebellum, this indicates that the vestibular system is a possible cause of later morphological, hormonal and neurosensory anomalies observed in AIS. Moreover, the simple lateral SCC MRI measurement demonstrated here could be used for early detection of AIS, selection of children for close follow-up, and initiation of preventive treatment before spinal deformity occurs. PMID:26186348

Differences in mushroom bodies morphogenesis in workers, queens and drones of Apis mellifera: neuroblasts proliferation and death.

PubMed

Roat, Thaisa Cristina; da Cruz Landim, Carminda

2010-06-01

Apis mellifera is an interesting model to neurobiological studies. It has a relatively small brain that commands the complex learning and memory tasks demanded by the social organization. An A. mellifera colony is made up of a queen, thousands of workers and a varying number of drones. The latter are males, whereas the former are the two female castes. These three phenotypes differ in morphology, physiology and behavior, correlated with their respective functions in the society. Such differences include the morphology and architecture of their brains. To understand the processes generating such polymorphic brains we characterized the cell division and cell death dynamics which underlie the morphogenesis of the mushroom bodies, through several methods suitable for evidence the time and place of occurrence. Cell death was detected in mushroom bodies of last larval instar and mainly in black-eyed pupae. Cell division was observed in mushroom bodies, primarily at the start of metamorphosis, exhibiting temporal differences among workers, queens and males. Copyright 2010 Elsevier Ltd. All rights reserved.

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

Using High-Resolution Comparison of Bedrock Properties and Channel Morphology to Empirically Characterize Erodibility in Fluvial Settings

NASA Astrophysics Data System (ADS)

Chilton, K.; Spotila, J. A.

2017-12-01

Bedrock erodibility exerts a primary control on landscape evolution and fluvial morphodynamics, but the relationships between erodibility and the many factors that influence it (rock strength, spacing and orientation of discontinuities, weathering susceptibility, erosive process, etc.) remain poorly defined. This results in oversimplification of erodibility in landscape evolution models, the primary example being the stream power incision model, which groups together factors which may influence erodibility into a single coefficient. There is therefore need to better define how bedrock properties influence erodibility and, in turn, channel form and evolution. This study seeks to deconvolve the relationships between bedrock material properties and erodibility by quantifying empirical relationships between substrate characteristics and bedrock channel morphology (slope, steepness index, width, form) at a high spatial resolution (5-10 m scale) in continuous and mixed alluvial-bedrock channels. We specifically focus on slowly eroding channels with minimal evidence for landscape transience, such that variations in channel morphology are mainly due to bedrock properties. We also use channels cut into sedimentary rock, which exhibit extreme variation (yet predictability and continuity) in discontinuity spacing. Here we present preliminary data comparing the morphology and bedrock properties of 1st through 4th order channels in the tectonically inactive Valley and Ridge province of the Appalachian Mountains, SW Virginia. Field surveys of channel slope, width, substrate, and form consist of 0.5 km long, continuous stream reaches through different intervals of tilted Paleozoic siliciclastic stratigraphy. Some surveys exhibit nearly complete bedrock exposure, whereas others are predominantly mixed, with localized bedrock reaches in high-slope knickzones. We statistically analyze relationships between fluvial morphology and lithology, strength (based on field and laboratory measurements), and discontinuity spacing and orientation. Results are informative for models of landscape evolution, and specifically provide insight into the controls on erosive process dominance (i.e., plucking vs. abrasion) and on the development and evolution of knickpoints in non-transient settings.

Endothelial cell responses in terms of adhesion, proliferation, and morphology to stiffness of polydimethylsiloxane elastomer substrates.

PubMed

Ataollahi, Forough; Pramanik, Sumit; Moradi, Ali; Dalilottojari, Adel; Pingguan-Murphy, Belinda; Wan Abas, Wan Abu Bakar; Abu Osman, Noor Azuan

2015-07-01

Extracellular environments can regulate cell behavior because cells can actively sense their mechanical environments. This study evaluated the adhesion, proliferation and morphology of endothelial cells on polydimethylsiloxane (PDMS)/alumina (Al2 O3 ) composites and pure PDMS. The substrates were prepared from pure PDMS and its composites with 2.5, 5, 7.5, and 10 wt % Al2 O3 at a curing temperature of 50°C for 4 h. The substrates were then characterized by mechanical, structural, and morphological analyses. The cell adhesion, proliferation, and morphology of cultured bovine aortic endothelial (BAEC) cells on substrate materials were evaluated by using resazurin assay and 1,1'-dioctadecyl-1,3,3,3',3'-tetramethylindocarbocyanine perchlorate-acetylated LDL (Dil-Ac-LDL) cell staining, respectively. The composites (PDMS/2.5, 5, 7.5, and 10 wt % Al2 O3 ) exhibited higher stiffness than the pure PDMS substrate. The results also revealed that stiffer substrates promoted endothelial cell adhesion and proliferation and also induced spread morphology in the endothelial cells compared with lesser stiff substrates. Statistical analysis showed that the effect of time on cell proliferation depended on stiffness. Therefore, this study concludes that the addition of different Al2 O3 percentages to PDMS elevated substrate stiffness which in turn increased endothelial cell adhesion and proliferation significantly and induced spindle shape morphology in endothelial cells. © 2014 Wiley Periodicals, Inc.

Distinct roles of cell wall biogenesis in yeast morphogenesis as revealed by multivariate analysis of high-dimensional morphometric data

PubMed Central

Okada, Hiroki; Ohnuki, Shinsuke; Roncero, Cesar; Konopka, James B.; Ohya, Yoshikazu

2014-01-01

The cell wall of budding yeast is a rigid structure composed of multiple components. To thoroughly understand its involvement in morphogenesis, we used the image analysis software CalMorph to quantitatively analyze cell morphology after treatment with drugs that inhibit different processes during cell wall synthesis. Cells treated with cell wall–affecting drugs exhibited broader necks and increased morphological variation. Tunicamycin, which inhibits the initial step of N-glycosylation of cell wall mannoproteins, induced morphologies similar to those of strains defective in α-mannosylation. The chitin synthase inhibitor nikkomycin Z induced morphological changes similar to those of mutants defective in chitin transglycosylase, possibly due to the critical role of chitin in anchoring the β-glucan network. To define the mode of action of echinocandin B, a 1,3-β-glucan synthase inhibitor, we compared the morphology it induced with mutants of Fks1 that contains the catalytic domain for 1,3-β-glucan synthesis. Echinocandin B exerted morphological effects similar to those observed in some fks1 mutants, with defects in cell polarity and reduced glucan synthesis activity, suggesting that echinocandin B affects not only 1,3-β-glucan synthesis, but also another functional domain. Thus our multivariate analyses reveal discrete functions of cell wall components and increase our understanding of the pharmacology of antifungal drugs. PMID:24258022

3D printing of biomimetic microstructures for cancer cell migration.

PubMed

Huang, Tina Qing; Qu, Xin; Liu, Justin; Chen, Shaochen

2014-02-01

To understand the physical behavior and migration of cancer cells, a 3D in vitro micro-chip in hydrogel was created using 3D projection printing. The micro-chip has a honeycomb branched structure, aiming to mimic 3D vascular morphology to test, monitor, and analyze differences in the behavior of cancer cells (i.e. HeLa) vs. non-cancerous cell lines (i.e. 10 T1/2). The 3D Projection Printing system can fabricate complex structures in seconds from user-created designs. The fabricated microstructures have three different channel widths of 25, 45, and 120 microns wide to reflect a range of blood vessel diameters. HeLa and 10 T1/2 cells seeded within the micro-chip were then analyzed for morphology and cell migration speed. 10 T1/2 cells exhibited greater changes in morphology due to channel size width than HeLa cells; however, channel width had a limited effect on 10 T1/2 cell migration while HeLa cancer cell migration increased as channel width decreased. This physiologically relevant 3D cancer tissue model has the potential to be a powerful tool for future drug discoveries and cancer migration studies.

Disparate rates, differing fates: tempo and mode of evolution changed from the Precambrian to the Phanerozoic

NASA Technical Reports Server (NTRS)

Schopf, J. W.

1994-01-01

Over the past quarter century, detailed genus- and species-level similarities in cellular morphology between described taxa of Precambrian microfossils and extant cyanobacteria have been noted and regarded as biologically and taxonomically significant by numerous workers world-wide. Such similarities are particularly well documented for members of the Oscillatoriaceae and Chroococcaceae, the two most abundant and widespread Precambrian cyanobacterial families. For species of two additional families, the Entophysalidaceae and Pleurocapsaceae, species-level morphologic similarities are supported by in-depth fossil-modern comparisons of environment, taphonomy, development, and behavior. Morphologically and probably physiologically as well, such cyanobacterial "living fossils" have exhibited an extraordinarily slow (hypobradytelic) rate of evolutionary change, evidently a result of the broad ecologic tolerance characteristic of many members of the group and a striking example of G. G. Simpson's [Simpson, G.G. (1944) Tempo and Mode in Evolution (Columbia Univ. Press, New York)] "rule of the survival of the relatively unspecialized." In both tempo and mode of evolution, much of the Precambrian history of life--that dominated by microscopic cyanobacteria and related prokaryotes--appears to have differed markedly from the more recent Phanerozoic evolution megascopic, horotelic, adaptationally specialized eukaryotes.

Controllable synthesis of magnetic Fe3O4 particles with different morphology by one-step hydrothermal route

NASA Astrophysics Data System (ADS)

Chen, Zhongtao; Du, Yi; Li, Zhongfu; Yang, Kai; Lv, Xingjie

2017-03-01

Well-defined Fe3O4 particles were successfully fabricated by a facile triethanolamine (TEA)-assisted method under mild hydrothermal conditions. Hydrated ferric salt was employed as the single iron precursor. TEA was used as the complexing agent and/or alkaline source. The crystalline phases of the as-obtained samples were characterized by X-ray diffraction (XRD). Furthermore, the morphology as well as the compositions of the samples were investigated by scanning electron microscopy (SEM) equipped with an energy dispersion spectroscopy (EDS). The results indicated that the products were Fe3O4 crystal phase, and the morphology and powder size of the particles were varied with adding different amount of NaOAc and keeping the content of TEA unchanged. On the basis of these results, the possible formation mechanism of Fe3O4 was discussed. It was observed that TEA and NaOAc affected the growth rate of crystal planes and nucleation. Besides, the magnetic property tested by a vibrating sample magnetometer (VSM) showed that the products exhibited a ferromagnetic behavior and possessed the excellent saturation magnetization (Ms) at room temperature.

High efficient perovskite solar cell material CH3NH3PbI3: Synthesis of films and their characterization

NASA Astrophysics Data System (ADS)

Bera, Amrita Mandal; Wargulski, Dan Ralf; Unold, Thomas

2018-04-01

Hybrid organometal perovskites have been emerged as promising solar cell material and have exhibited solar cell efficiency more than 20%. Thin films of Methylammonium lead iodide CH3NH3PbI3 perovskite materials have been synthesized by two different (one step and two steps) methods and their morphological properties have been studied by scanning electron microscopy and optical microscope imaging. The morphology of the perovskite layer is one of the most important parameters which affect solar cell efficiency. The morphology of the films revealed that two steps method provides better surface coverage than the one step method. However, the grain sizes were smaller in case of two steps method. The films prepared by two steps methods on different substrates revealed that the grain size also depend on the substrate where an increase of the grain size was found from glass substrate to FTO with TiO2 blocking layer to FTO without any change in the surface coverage area. Present study reveals that an improved quality of films can be obtained by two steps method by an optimization of synthesis processes.

Morphology-diet relationships in four killifishes (Teleostei, Cyprinodontidae, Orestias) from Lake Titicaca.

PubMed

Maldonado, E; Hubert, N; Sagnes, P; De Mérona, B

2009-02-01

This study explores the relationship between morphology and diet in four Andean killifishes (Orestias) from Lake Titicaca that are known to differ in habitat use. Species that fed preferentially on amphipods (Orestias albus) or molluscs (Orestias luteus) separated in multivariate space from other species that feed on cladocera and algae (Orestias agassii and Orestias jussiei). Generally, specimens feeding on cladocera were characterized by a short, blunt nose with a small mouth; whereas, specimens feeding on amphipods exhibited a long snout with a large mouth. Specimens including molluscs in their diet tended to have a larger posterior part of the head and the larger opercles than others; while the occurrence of substratum in gut content was generally related to a short but deep head. The present analysis suggests that the littoral O. jussiei has an intermediate phenotype and diet between the pelagic (O. agassii) and benthic (O. albus and O. luteus) species. Results suggest that resource partitioning was occurring and that several morphological traits relate to characteristics of the diet, and it is inferred that the benthic, the pelagic and the littoral zones in the lake host different prey communities constituting distinct adaptive landscapes.

Morphological and histological characters of penile organization in eleven species of molossid bats.

PubMed

Comelis, Manuela T; Bueno, Larissa M; Góes, Rejane M; Taboga, S R; Morielle-Versute, Eliana

2018-04-01

The penis is the reproductive organ that ensures efficient copulation and success of internal fertilization in all species of mammals, with special challenges for bats, where copulation can occur during flight. Comparative anatomical analyses of different species of bats can contribute to a better understanding of morphological diversity of this organ, concerning organization and function. In this study, we describe the external morphology and histomorphology of the penis and baculum in eleven species of molossid bats. The present study showed that penile organization in these species displayed the basic vascular mammalian pattern and had a similar pattern concerning the presence of the tissues constituting the penis, exhibiting three types of erectile tissue (the corpus cavernosum, accessory cavernous tissue, and corpus spongiosum) around the urethra. However, certain features varied among the species, demonstrating that most species are distinguishable by glans and baculum morphology and glans histological organization. Major variations in glans morphology were genus-specific, and the greatest similarities were shared by Eumops species and N. laticaudatus. The greatest interspecific similarities occurred between M. molossus and M. rufus and between Eumops species. Save for M. molossus and M. rufus, morphology of the baculum was species-specific; and in E. perotis, it did not occur in all specimens, indicating that it is probably under selection. In the histological organization, the most evident differences were number of septa and localization of the corpora cavernosa. In species with a baculum (Molossus, Eumops and Nyctinomops species), the corpora cavernosa predominantly occupied the dorsal region of the penile glans and is associated with the proximal (basal) portion of the baculum. In species that do not have a baculum (Cynomops, Molossops and Neoplatymops species), the corpora cavernosa predominantly occupied the ventro-lateral region of the glans. Copyright © 2018 Elsevier GmbH. All rights reserved.

Effects of long-term preservation on amphibian body conditions: implications for historical morphological research

PubMed Central

Shu, Guocheng; Gong, Yuzhou; Xie, Feng; Wu, Nicholas C.

2017-01-01

Measurements of historical specimens are widely applied in studies of taxonomy, systematics, and ecology, but biologists often assume that the effects of preservative chemicals on the morphology of amphibian specimens are minimal in their analyses. We compared the body length and body mass of 182 samples of 13 live and preserved (up to 10 years) anuran species and found that the body length and body mass of preserved specimens significantly decreased by 6.1% and 24.8%, respectively, compared to those measurements of their live counterparts. The changes in body length and mass also exhibited highly significant variations between species. Similarly, there were significant differences in shrinkage of body length and body mass between sexes, where males showed greater shrinkage in body length and body mass compared to females. Preservation distorted the magnitude of the interspecific differences in body length observed in the fresh specimens. Overall, the reduction in body length or mass was greater in longer or heavier individuals. Due to the effects of preservation on amphibian morphology, we propose two parsimonious conversion equations to back-calculate the original body length and body mass of studied anurans for researchers working with historical data, since morphological data from preserved specimens may lead to incorrect biological interpretations when comparing to fresh specimens. Therefore, researchers should correct for errors due to preservation effects that may lead to the misinterpretation of results. PMID:28929024

Morphological and Genetic Analysis of Four Color Morphs of Bean Leaf Beetle.

PubMed

Tiroesele, Bamphitlhi; Skoda, Steven R; Hunt, Thomas E; Lee, Donald J; Ullah, Muhammad Irfan; Molina-Ochoa, Jaime; Foster, John E

2018-03-01

Bean leaf beetle (BLB), Cerotoma trifurcata (Forster; Coleoptera: Chrysomelidae), exhibits considerable color variation but little is known about the underlying genetic structure and gene flow among color phenotypes. Genetic and morphological variation among four color phenotypes-green with spots (G+S), green without spots (G-S), red with spots (R+S) and red without spots (R-S)-were analyzed using amplified fragment length polymorphisms (AFLP) and morphometrics, respectively. AFLP generated 175 markers that showed ≥80% polymorphism. Analysis of molecular variance (AMOVA) indicated that genetic variation was greatest within phenotypes (82.6-84.0%); gene flow among the four phenotypes was relatively high (Nm = 3.82). The dendrogram and STRUCTURE analysis indicated some population divergence of G-S from the other phenotypes. Morphological parameters were similar among phenotypes except that R+S showed significant differences in weight and body-length. Canonical variables 1 and 2, based on average morphometric characters, accounted for 98% of the total variation; some divergence was indicated between G+S and R+S from each other and from the G-S/R-S BLB color morphs. The pattern of genetic variation indicated potential divergence of G-S and G+S from each other and from R-S and R+S. Although these results indicate that the four different color morphs are not genetically or reproductively isolated, there is some genetic differentiation/structure and morphological dissimilarity suggesting weak/incomplete isolation.

Functional morphology of comminuting feeding structures of Trichodactylus borellianus (Brachyura, Decapoda, Trichodactylidae), an omnivorous freshwater crab.

PubMed

Carvalho, Débora de Azevedo; Viozzi, Maria Florencia; Collins, Pablo Agustín; Williner, Verónica

2017-07-01

Crustaceans exhibit great diversity of feeding structures with morphological traits that are useful to infer the general trophic habits of species. In this study, we analyzed the functional morphology of comminuting feeding structures (mandibles, chelipeds, gastric mill) of the freshwater crab Trichodactylus borellianus directly related with the food fragmentation. The heterochely and mechanical advantage (MA) of the chelae were also studied. In both analyses, we considered the relationship between morphology and the natural diet. We expected to find a consistent relation between feeding habits and morphological traits. In general, we found simple structures armed with uniform setal systems and feeding appendages without pronounced teeth or spines. Mandibles have primarily cutting functions, helping with the food anchoring and fragmentation with mandibular palps armed with pappose setae. Chelipeds were covered with spines and simple setae. Adult males exhibited right-handedness with high MA of the major chelae. The ingested, relatively large pieces of food are finally chewed by a gastric mill equipped with sharp cusps characteristic of decapods with low ingestion of crude fiber material. The morphology of the feeding apparatus revealed that it is well adapted to an omnivorous diet, being able to cope with dietary changes. Copyright © 2017 Elsevier Ltd. All rights reserved.

Cell–material interactions on biphasic polyurethane matrix

PubMed Central

Dicesare, Patrick; Fox, Wade M.; Hill, Michael J.; Krishnan, G. Rajesh; Yang, Shuying; Sarkar, Debanjan

2013-01-01

Cell–matrix interaction is a key regulator for controlling stem cell fate in regenerative tissue engineering. These interactions are induced and controlled by the nanoscale features of extracellular matrix and are mimicked on synthetic matrices to control cell structure and functions. Recent studies have shown that nanostructured matrices can modulate stem cell behavior and exert specific role in tissue regeneration. In this study, we have demonstrated that nanostructured phase morphology of synthetic matrix can control adhesion, proliferation, organization and migration of human mesenchymal stem cells (MSCs). Nanostructured biodegradable polyurethanes (PU) with segmental composition exhibit biphasic morphology at nanoscale dimensions and can control cellular features of MSCs. Biodegradable PU with polyester soft segment and hard segment composed of aliphatic diisocyanates and dipeptide chain extender were designed to examine the effect polyurethane phase morphology. By altering the polyurethane composition, morphological architecture of PU was modulated and its effect was examined on MSC. Results show that MSCs can sense the nanoscale morphology of biphasic polyurethane matrix to exhibit distinct cellular features and, thus, signifies the relevance of matrix phase morphology. The role of nanostructured phases of a synthetic matrix in controlling cell–matrix interaction provides important insights for regulation of cell behavior on synthetic matrix and, therefore, is an important tool for engineering tissue regeneration. PMID:23255285

Coma Morphology of Recent Comets: C/ISON (2012 S1), C/Pan-STARRS (2012 K1), C/Jacques (2014 E2), and C/Siding Spring (2013 A1)

NASA Astrophysics Data System (ADS)

Knight, Matthew M.; Schleicher, David G.

2014-11-01

We will present preliminary results from recent and upcoming imaging campaigns of four comets using Lowell Observatory’s 4.3-m Discovery Channel Telescope, 42-in Hall Telescope, and/or 31-in telescope: 1. Observations of C/ISON (2012 S1) were carried out from January through November 2013. A small, sunward fan was detected in dust images acquired in March, April, May, and September. Two faint CN features approximately orthogonal to the tail appeared on November 1 and were visible until our final night of data on November 12. This significantly predates their first reported appearance in broadband images on November 14 (Boehnhard et al., CBET 3715; Ye et al., CBET 3718) and suggests that the features were not caused by a catastrophic disruption of the nucleus at that time.2. We observed C/Pan-STARRS (2012 K1) regularly from October 2013 through June 2014 when it entered solar conjunction. Enhanced CN images in May and June 2014 exhibited a side-on pinwheel morphology that varied from night to night; similar morphology was not seen in concurrent dust images. Analysis of the rotation period is underway. 3. C/Jacques (2014 E2) was observed in April, May, and August 2014, and additional observations are scheduled through September 2014. After enhancement of the August images, Jacques exhibited two side-on CN corkscrews roughly orthogonal to the tail. The CN morphology was different from night to night but did not vary noticeably during ~1 hr of observations on a given night. Jacques also exhibited a smaller sunward dust feature in August that did not appear to vary during the observations. We will combine these data with our scheduled observations to investigate periodicity and compare the spatial distribution of multiple gas species. 4. Observations of C/Siding Spring (2013 A1) are scheduled around its close approach to Mars on October 19, 2014. This work is supported by NASA’s Planetary Astronomy Program grants NNX09AB51G and NNX11AD95G.

Morphology-Tuned Synthesis of Nickel Cobalt Selenides as Highly Efficient Pt-Free Counter Electrode Catalysts for Dye-Sensitized Solar Cells.

PubMed

Qian, Xing; Li, Hongmei; Shao, Li; Jiang, Xiancai; Hou, Linxi

2016-11-02

In this work, morphology-tuned ternary nickel cobalt selenides based on different Ni/Co molar ratios have been synthesized via a simple precursor conversion method and used as counter electrode (CE) materials for dye-sensitized solar cells (DSSCs). The experimental facts and mechanism analysis clarified the possible growth process of product. It can be found that the electrochemical performance and structures of ternary nickel cobalt selenides can be optimized by tuning the Ni/Co molar ratio. Benefiting from the unique morphology and tunable composition, among the as-prepared metal selenides, the electrochemical measurements showed that the ternary nickel cobalt selenides exhibited a more superior electrocatalytic activity in comparison with binary Ni and Co selenides. In particular, the three-dimensional dandelion-like Ni 0.33 Co 0.67 Se microspheres delivered much higher power conversion efficiency (9.01%) than that of Pt catalyst (8.30%) under AM 1.5G irradiation.

Exceptional preservation reveals gastrointestinal anatomy and evolution in early actinopterygian fishes

PubMed Central

Argyriou, Thodoris; Clauss, Marcus; Maxwell, Erin E.; Furrer, Heinz; Sánchez-Villagra, Marcelo R.

2016-01-01

Current knowledge about the evolutionary morphology of the vertebrate gastrointestinal tract (GIT) is hindered by the low preservation potential of soft tissues in fossils. Exceptionally preserved cololites of individual †Saurichthys from the Middle Triassic of Switzerland provide unique insights into the evolutionary morphology of the GIT. The GIT of †Saurichthys differed from that of other early actinopterygians, and was convergent to that of some living sharks and rays, in exhibiting up to 30 turns of the spiral valve. Dissections and literature review demonstrate the phylogenetic diversity of GIT features and signs of biological factors that influence its morphology. A phylogenetically informed analysis of a dataset containing 134 taxa suggests that body size and phylogeny are important factors affecting the spiral valve turn counts. The high number of turns in the spiral valve of †Saurichthys and some recent sharks and rays reflect both energetically demanding lifestyles and the evolutionary histories of the groups. PMID:26732746

Tailoring the morphology of electrodeposited ZnO and its photoluminescence properties

NASA Astrophysics Data System (ADS)

Cui, H.; Mollar, M.; Marí, B.

2011-01-01

High density ZnO columnar films with well-aligned and well-perpendicular to the surface of film were electrodeposited on ITO substrates by using an electrolyte consisting of a mix of water and organic solvent namely dimethylsulfoxide (DMSO). The effect of mixing ratio of water and DMSO on the growth of film has been examined critically. SEM images have shown that well-oriented ZnO quasi-nano columns were formed perpendicular to the substrate. At the same time we found there are three kinds of competitions for growth of ZnO crystalmorphology i.e. column, rod and needle like. The needle like morphology has high density with well-aligned structure. The reasons for the growth of films of different morphology and their photoluminescence (PL) properties have been presented and discussed. It has been found that the three-dimensional (3D) ordered ZnO structure exhibits high intensity PL band which may shift their position and intensity with the varying conditions of depositions.

Lithography-free glass surface modification by self-masking during dry etching

NASA Astrophysics Data System (ADS)

Hein, Eric; Fox, Dennis; Fouckhardt, Henning

2011-01-01

Glass surface morphologies with defined shapes and roughness are realized by a two-step lithography-free process: deposition of an ~10-nm-thin lithographically unstructured metallic layer onto the surface and reactive ion etching in an Ar/CF4 high-density plasma. Because of nucleation or coalescence, the metallic layer is laterally structured during its deposition. Its morphology exhibits islands with dimensions of several tens of nanometers. These metal spots cause a locally varying etch velocity of the glass substrate, which results in surface structuring. The glass surface gets increasingly rougher with further etching. The mechanism of self-masking results in the formation of surface structures with typical heights and lateral dimensions of several hundred nanometers. Several metals, such as Ag, Al, Au, Cu, In, and Ni, can be employed as the sacrificial layer in this technology. Choice of the process parameters allows for a multitude of different glass roughness morphologies with individual defined and dosed optical scattering.

Agronomic, chemical and genetic profiles of hot peppers (Capsicum annuum ssp.).

PubMed

De Masi, Luigi; Siviero, Pietro; Castaldo, Domenico; Cautela, Domenico; Esposito, Castrese; Laratta, Bruna

2007-08-01

A study on morphology, productive yield, main quality parameters and genetic variability of eight landraces of hot pepper (Capsicum annuum ssp.) from Southern Italy has been performed. Morphological characters of berries and productivity values were evaluated by agronomic analyses. Chemical and genetic investigations were performed by HPLC and random amplified polymorphic DNA (RAPD)-PCR, respectively. In particular, carotenoid and capsaicinoid (pungency) contents were considered as main quality parameters of hot pepper. For the eight selected samples, genetic similarity values were calculated from the generated RAPD fragments and a dendrogram of genetic similarity was constructed. All the eight landraces exhibited characteristic RAPD patterns that allowed their characterization. Agro-morphological and chemical determinations were found to be adequate for selection, but they resulted useful only for plants grown in the same environmental conditions. RAPD application may provide a more reliable way based on DNA identification. The results of our study led to the identification of three noteworthy populations, suitable for processing, which fitted into different clusters of the dendrogram.

Study of morphological and mechanical features of multinuclear and mononuclear SW480 cells by atomic force microscopy.

PubMed

Liu, Jinyun; Qu, Yingmin; Wang, Guoliang; Wang, Xinyue; Zhang, Wenxiao; Li, Jingmei; Wang, Zuobin; Li, Dayou; Jiang, Jinlan

2018-01-01

This article studies the morphological and mechanical features of multinuclear and mononuclear SW480 colon cancer cells by atomic force microscopy to understand their drug-resistance. The SW480 cells were incubated with the fullerenol concentrations of 1 mg/ml and 2 mg/ml. Morphological and mechanical features including the height, length, width, roughness, adhesion force and Young's modulus of three multinuclear cell groups and three mononuclear cell groups were imaged and analyzed. It was observed that the features of multinuclear cancer cells and mononuclear cancer cells were significantly different after the treatment with fullerenol. The experiment results indicated that the mononuclear SW480 cells were more sensitive to fullerenol than the multinuclear SW480 cells, and the multinuclear SW480 cells exhibited a stronger drug-resistance than the mononuclear SW480 cells. This work provides a guideline for the treatments of multinuclear and mononuclear cancer cells with drugs. © 2017 Wiley Periodicals, Inc.

Co-Precipitation Synthesis of Gadolinium Aluminum Gallium Oxide (GAGG) via Different Precipitants

NASA Astrophysics Data System (ADS)

Sun, Yan; Yang, Shenghui; Zhang, Ye; Jiang, Jun; Jiang, Haochuan

2014-02-01

In order to obtain a uniform transparent ceramic scintillator, well-dispersed fine starting powders with high-purity, small grain size, spherical morphology and high sinter-ability are necessary. In this study, Ce3+ doped gadolinium aluminum gallium garnet Gd3Al3Ga2O12 (GAGG) powders were synthesized by the co-precipitation method. NH4OH, NH4HCO3 and the mixed solution of NH4OH and NH4HCO3 were used as precipitants, respectively. The precursor composition, phase formation process, microstructure, morphology, particle size distribution and luminescent properties of obtained GAGG powders were measured. The results show that powders prepared using the mixed precipitant exhibit the best microstructural morphology, good sinter-ability and highest luminescent intensity. Pure GAGG polycrystalline powders could be obtained at about 950°C for 1.5 h and the average size of the particles is about 50 nm. The photoluminescence spectrum shows a strong green-yellow emission near 540 nm.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hannachi, Amira, E-mail: amira.hannachi88@gmail.com; Maghraoui-Meherzi, Hager

Manganese sulfide thin films have been deposited on glass slides by chemical bath deposition (CBD) method. The effects of preparative parameters such as deposition time, bath temperature, concentration of precursors, multi-layer deposition, different source of manganese, different complexing agent and thermal annealing on structural and morphological film properties have been investigated. The prepared thin films have been characterized using the X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive X-ray analysis (EDX). It exhibit the metastable forms of MnS, the hexagonal γ-MnS wurtzite phase with preferential orientation in the (002) plane or the cubic β-MnS zinc blende with preferentialmore » orientation in the (200) plane. Microstructural studies revealed the formation of MnS crystals with different morphologies, such as hexagons, spheres, cubes or flowers like. - Graphical Abstract: We report the preparation of different phases of manganese sulfide thin films (γ, β and α-MnS) by chemical bath deposition method. The effects of deposition parameters such as deposition time and temperature, concentrations of precursors and multi-layer deposition on MnS thin films structure and morphology were investigated. The influence of thermal annealing under nitrogen atmosphere at different temperature on MnS properties was also studied. Different manganese precursors as well as different complexing agent were also used. - Highlights: • γ and β-MnS films were deposited on substrate using the chemical bath deposition. • The effect of deposition parameters on MnS film properties has been investigated. • Multi-layer deposition was also studied to increase film thickness. • The effect of annealing under N{sub 2} at different temperature was investigated.« less

Morphological and community changes of turf algae in competition with corals

PubMed Central

Cetz-Navarro, Neidy P.; Quan-Young, Lizette I.; Espinoza-Avalos, Julio

2015-01-01

The morphological plasticity and community responses of algae competing with corals have not been assessed. We evaluated eight morphological characters of four species of stoloniferous clonal filamentous turf algae (FTA), including Lophosiphonia cristata (Lc) and Polysiphonia scopulorum var. villum (Psv), and the composition and number of turf algae (TA) in competition for space with the coral Orbicella spp. under experimental and non-manipulated conditions. All FTA exhibited morphological responses, such as increasing the formation of new ramets (except for Psv when competing with O. faveolata). Opposite responses in the space between erect axes were found when Psv competed with O. faveolata and when Lc competed with O. annularis. The characters modified by each FTA species, and the number and composition of TA species growing next to coral tissue differed from that of the TA growing at ≥3 cm. The specific and community responses indicate that some species of TA can actively colonise coral tissue and that fundamental competitive interactions between the two types of organisms occur within the first millimetres of the coral−algal boundary. These findings suggest that the morphological plasticity, high number, and functional redundancy of stoloniferous TA species favour their colonisation of coral tissue and resistance against coral invasion. PMID:26244816

Morphological observation and analysis using automated image cytometry for the comparison of trypan blue and fluorescence-based viability detection method.

PubMed

Chan, Leo Li-Ying; Kuksin, Dmitry; Laverty, Daniel J; Saldi, Stephanie; Qiu, Jean

2015-05-01

The ability to accurately determine cell viability is essential to performing a well-controlled biological experiment. Typical experiments range from standard cell culturing to advanced cell-based assays that may require cell viability measurement for downstream experiments. The traditional cell viability measurement method has been the trypan blue (TB) exclusion assay. However, since the introduction of fluorescence-based dyes for cell viability measurement using flow or image-based cytometry systems, there have been numerous publications comparing the two detection methods. Although previous studies have shown discrepancies between TB exclusion and fluorescence-based viability measurements, image-based morphological analysis was not performed in order to examine the viability discrepancies. In this work, we compared TB exclusion and fluorescence-based viability detection methods using image cytometry to observe morphological changes due to the effect of TB on dead cells. Imaging results showed that as the viability of a naturally-dying Jurkat cell sample decreased below 70 %, many TB-stained cells began to exhibit non-uniform morphological characteristics. Dead cells with these characteristics may be difficult to count under light microscopy, thus generating an artificially higher viability measurement compared to fluorescence-based method. These morphological observations can potentially explain the differences in viability measurement between the two methods.

Form and function of the human and chimpanzee forefoot: implications for early hominin bipedalism

PubMed Central

Fernández, Peter J.; Holowka, Nicholas B.; Demes, Brigitte; Jungers, William L.

2016-01-01

During bipedal walking, modern humans dorsiflex their forefoot at the metatarsophalangeal joints (MTPJs) prior to push off, which tightens the plantar soft tissues to convert the foot into a stiff propulsive lever. Particular features of metatarsal head morphology such as “dorsal doming” are thought to facilitate this stiffening mechanism. In contrast, chimpanzees are believed to possess MTPJ morphology that precludes high dorsiflexion excursions during terrestrial locomotion. The morphological affinity of the metatarsal heads has been used to reconstruct locomotor behavior in fossil hominins, but few studies have provided detailed empirical data to validate the assumed link between morphology and function at the MTPJs. Using three-dimensional kinematic and morphometric analyses, we show that humans push off with greater peak dorsiflexion angles at all MTPJs than do chimpanzees during bipedal and quadrupedal walking, with the greatest disparity occurring at MTPJ 1. Among MTPJs 2–5, both species exhibit decreasing peak angles from medial to lateral. This kinematic pattern is mirrored in the morphometric analyses of metatarsal head shape. Analyses of Australopithecus afarensis metatarsals reveal morphology intermediate between humans and chimpanzees, suggesting that this species used different bipedal push-off kinematics than modern humans, perhaps resulting in a less efficient form of bipedalism. PMID:27464580

Influences of Probe’s Morphology for Metal Ion Detection Based on Light-Addressable Potentiometric Sensors

PubMed Central

Shao, Chen; Zhou, Shuang; Yin, Xuebo; Gu, Yajun; Jia, Yunfang

2016-01-01

The sensing mechanism of binding Hg2+ into thymine-thymine (T-T) mismatched base pairs was introduced into a light-addressable potentiometric sensor (LAPS) with anti-Hg2+ aptamer as the sensing units. Three kinds of T-rich single-strand DNA (ssDNA) chains with different spacer lengths, from 0 to 12 –CH2 groups, were designed to investigate surface charge and morphological effects on the LAPS’ output. First, by comparing the responding of LAPS modified with three kinds of ssDNA, it was found that the best performance for Hg2+ sensing was exhibited by the probe without –CH2 groups. The detection limit of Hg2+ ion was 1 ppt under the optimal condition. Second, the cooperative effects of surface charge and morphology on the output were observed by the controlled experiments. The two effects were the negative charge balanced by metal cations and the morphological changing caused by the formation of T-Hg2+-T structure. In conclusion, not only the influences of the aptamer probe’s morphology and surface charge was investigated on the platform of LAPS, but also sensing Hg2+ ions was achieved for the first time by the presented aptamer LAPS. PMID:27187412

The identification of sympatric cryptic free-living nematode species in the Antarctic intertidal

PubMed Central

Canales-Aguirre, Cristian B.; Nuñez, Daniela; Pérez, Karla; Hernández, Crisitan E.; Brante, Antonio

2017-01-01

The diversity of free-living nematodes in the beaches of two Antarctic islands, King George and Deception islands was investigated. We used morphological and molecular (LSU, and two fragments of SSU sequences) approaches to evaluate 236 nematodes. Specimens were assigned to at least genera using morphology and were assessed for the presence of cryptic speciation. The following genera were identified: Halomonhystera, Litoditis, Enoploides, Chromadorita, Theristus, Oncholaimus, Viscosia, Gammanema, Bathylaimus, Choanolaimus, and Paracanthonchus; along with specimens from the families Anticomidae and Linhomoeidae. Cryptic speciation was identified within the genera Halomonhystera and Litoditis. All of the cryptic species identified live sympatrically. The two cryptic species of Halomonhystera exhibited no significant morphological differences. However, Litoditis species 2 was significantly larger than Litoditis species 1. The utility of molecular data in confirming the identifications of some of the morphologically more challenging families of nematodes was demonstrated. In terms of which molecular sequences to use for the identification of free-living nematodes, the SSU sequences were more variable than the LSU sequences, and thus provided more resolution in the identification of cryptic speciation. Finally, despite the considerable amount of time and effort required to put together genetic and morphological data, the resulting advance in our understanding of diversity and ecology of free-living marine nematodes, makes that effort worthwhile. PMID:28982192

Rational Design and Synthesis of Carboxylate Gemini Surfactants with an Excellent Aggregate Behavior for Nano-La2O3 Morphology-Controllable Preparation.

PubMed

Liao, Xueming; Gao, Zhinong; Xia, Yan; Niu, Fei; Zhai, Wenzhong

2017-04-04

A series of carboxylate gemini surfactants (CGS, C n -Φ-C n , n = 12, 14, 16, 18) with diphenyl ketone as a spacer group were prepared using a simple and feasible synthetic method. These CGS exhibited an excellent surface activity with extremely low critical micelle concentration (CMC) value (approximately 10 -5 mol/L), good performance in reducing surface tension (nearly 30 mN/m), and the ability of molecular self-assembly into different aggregate morphologies via adjusting the concentrations, which is attributed to the introduction of diphenyl ketone and carboxylic acid ammonium salt in the molecular structure. Moreover, the surface activity and self-assembly ability of CGS were further optimized by tuning the length of the tail chain. These excellent properties imply that CGS can be a soft template to prepare nanomaterials, especially in morphology-controllable synthesis. By adjusting the concentration of one of CGS (C 12 -Φ-C 12 ), nano-La 2 O 3 particles with diverse morphologies were obtained, including spherical shape, bead-chain shape, rod shape, velvet-antler shape, cedar shape, and bowknot shape. This work offers a vital insight into the rational design of template agents for the development of morphology-controllable nanomaterials.

Optical and mechanical properties of nanocrystalline ZrC thin films grown by pulsed laser deposition.

DOE PAGES

Craciun, D.; Socol, G.; Lambers, E.; ...

2015-01-17

Thin ZrC films (<500 nm) were grown on (100) Si substrates at a substrate temperature of 500 °C by the pulsed laser deposition (PLD) technique using a KrF excimer laser under different CH 4 pressures. Glancing incidence X-ray diffraction showed that films were nanocrystalline, while X-ray reflectivity studies found out films were very dense and exhibited a smooth surface morphology. Optical spectroscopy data shows that the films have high reflectivity (>90%) in the infrared region, characteristic of metallic behavior. Nanoindentation results indicated that films deposited under lower CH 4 pressures exhibited slightly higher nanohardness and Young modulus values than filmsmore » deposited under higher pressures. As a result, tribological characterization revealed that these films exhibited relatively high wear resistance and steady-state friction coefficients on the order of μ = 0.4.« less

Pre-Quaternary divergence and subsequent radiation explain longitudinal patterns of genetic and morphological variation in the striped skink, Heremites vittatus.

PubMed

Baier, Felix; Schmitz, Andreas; Sauer-Gürth, Hedwig; Wink, Michael

2017-06-09

Many animal and plant species in the Middle East and northern Africa have a predominantly longitudinal distribution, extending from Iran and Turkey along the eastern Mediterranean coast into northern Africa. These species are potentially characterized by longitudinal patterns of biological diversity, but little is known about the underlying biogeographic mechanisms and evolutionary timescales. We examined these questions in the striped skink, Heremites vittatus, one such species with a roughly longitudinal distribution across the Middle East and northern Africa, by analyzing range-wide patterns of mitochondrial DNA (mtDNA) sequence and multi-trait morphological variation. The striped skink exhibits a basic longitudinal organization of mtDNA diversity, with three major mitochondrial lineages inhabiting northern Africa, the eastern Mediterranean coast, and Turkey/Iran. Remarkably, these lineages are of pre-Quaternary origin, and are characterized by p-distances of 9-10%. In addition, within each of these lineages a more recent Quaternary genetic diversification was observed, as evidenced by deep subclades and high haplotype diversity especially in the Turkish/Iranian and eastern Mediterranean lineages. Consistent with the genetic variation, our morphological analysis revealed that the majority of morphological traits show significant mean differences between specimens from northern Africa, the eastern Mediterranean coast, and Turkey/Iran, suggesting lineage-specific trait evolution. In addition, a subset of traits exhibits clinal variation along the eastern Mediterranean coast, potentially indicating selection gradients at the geographic transition from northern Africa to Anatolia. The existence of allopatric, morphologically and genetically divergent lineages suggests that Heremites vittatus might represent a complex with several taxa. Our work demonstrates that early divergence events in the Pliocene, likely driven by both climatic and geological factors, established the longitudinal patterns and distribution of Heremites vittatus. Subsequent radiation during the Pleistocene generated the genetic and morphological diversity observed today. Our study provides further evidence that longitudinal diversity patterns and species distributions in the Middle East and northern Africa were shaped by complex evolutionary processes, involving the region's intricate geological history, climatic oscillations, and the presence of the Sahara.

The biophysical effects of deuterium oxide on biomolecules and living cells through open notebook science

NASA Astrophysics Data System (ADS)

Salvagno, Anthony L.

This dissertation explores various effects of deuterium oxide (D2O also known as heavy water) in nature. Water is everywhere and interacts with just about everything. As such, it would be quite a daunting task to characterize every effect that water exhibits on everything in the universe. This research is a small piece of the puzzle, and provides some fundamental understanding of how water interacts with other molecules. This is done from two viewpoints: (1) the effects of heavy water on living cells and (2) the effects of heavy water on molecules. Varying concentrations of deuterium oxide were used as the growing solvent for four different organisms: S. cerevisiae, E. coli, A. thaliana, and N. tabacum. In each case growth rates and morphology was assessed and compared to the wild type. Organisms were surveyed for potential phenotypes exhibited in the presence of extremely low and high concentrations of D2O. In every organism, growth is increasingly inhibited in higher concentrations of D2O compared to lower concentrations of D2O. In the case of tobacco, a root hair phenotype was exhibited in the presence of deuterium depleted water (<1ppm deuterium atoms). Roots also grew faster in 1% D2O and DDW, compared to natural water. For Arabidopsis, root germination is statistically indistinguishable between DI water and 33% D2O. Growth of the plant in 10% D2O is identical to that of natural water, and potentially healthier. Meanwhile, plants grown in 60% D2O exhibit slower growth and leaf discoloration. Tests on E. coli reveal inconsistent growth rates, but exhibit increased growth in DDW when adapted to D2O. Cellular and colonial morphology is also very distinguished from the wt. Cells appear to remain joined after cellular fission, while colonies exhibit brainy structures. Yeast morphology is quite different. Yeast cells remain joined after mitosis in 99% D2O, causing large cellular aggregates, while colonies become slightly asymmetric. Adaptation of yeast to D2O was not possible. Molecular effects were examined using a variety of tools including: dynamic light spectroscopy, Fourier transform-infrared spectroscopy, cavity ring-down spectroscopy, and optical tweezers. Heat induced protein aggregation was possible in H2O, but prevented in the presence of D2O and analyzed via DLS. Deuterium exchange and replacement was observed and quantified using both FT-IR and CRDS. With FT-IR it was possible to identify differences between solvents, while the time-scale of hydrogen-deuterium exchange was quantified for bulk water with CRDS. Using optical tweezers, DNA was overstretched in both H2O and D2O. The average force for DNA overstretching was found to be ~2.5pN higher in D2O compared to H2O. Deuterium oxide has a stabilizing force on biomolecules, which prevents protein denaturing and can affect the timing for cellular processes. It is because of this molecular property that D2O is observed to affect organisms grown with D2O instead of H2O. Despite this, there seems to be an optimal concentration of deuterium which is above the natural concentration of 155.6ppm. In the presence of deuterium depleted water, cells exhibit signs of stress, further demonstrating that deuterium isn't merely tolerated in solution, but actually required as hypothesized by Gilbert N. Lewis in 1934.

Proprioception in the extraocular muscles of mammals and man.

PubMed

Blumer, Roland; Konacki, Kadriye Zeynep; Streicher, Johannes; Hoetzenecker, Wolfram; Blumer, Michael Josef Franz; Lukas, Julius-Robert

2006-06-01

This article summarizes the authors' previous studies on proprioceptors in extraocular muscles (EOMs) of mammals and man. They report on muscle spindles in the EOMs of man, Golgi tendon organs in the EOMs of even-toed ungulates, and palisade endings in the EOMs of the cat. Muscle spindles: Muscle spindles are present in the EOMs of some mammals and in the EOMs of man. Compared with muscle spindles in other skeletal muscles, those in human EOMs exhibit structural differences. These structural differences may indicate a special function. Golgi tendon organs: Golgi tendon organs are absent in human EOMs. Golgi tendon organs exhibiting a specific morphology are present in the EOMs of even-toed ungulates. Their high number and rich innervation indicate functional importance. Palisade endings: Palisade endings are nervous end organs confined to the EOMs of mammals and man. It is assumed that these organs have a proprioceptive function. The authors show that palisade endings are immunoreactive for antibodies against choline acetyltransferase. Neuromuscular contacts, if present in palisade endings, are alpha -bungarotoxin positive as well. Taken together, these results show that palisade endings exhibit molecular characteristics of effector organs.

ZnO deposition on metal substrates: Relating fabrication, morphology, and wettability

NASA Astrophysics Data System (ADS)

Beaini, Sara S.; Kronawitter, Coleman X.; Carey, Van P.; Mao, Samuel S.

2013-05-01

It is not common practice to deposit thin films on metal substrates, especially copper, which is a common heat exchanger metal and practical engineering material known for its heat transfer properties. While single crystal substrates offer ideal surfaces with uniform structure for compatibility with oxide deposition, metallic surfaces needed for industrial applications exhibit non-idealities that complicate the fabrication of oxide nanostructure arrays. The following study explored different ZnO fabrication techniques to deposit a (super)hydrophobic thin film of ZnO on a metal substrate, specifically copper, in order to explore its feasibility as an enhanced condensing surface. ZnO was selected for its non-toxicity, ability to be made (super)hydrophobic with hierarchical roughness, and its photoinduced hydrophilicity characteristic, which could be utilized to pattern it to have both hydrophobic-hydrophilic regions. We investigated the variation of ZnO's morphology and wetting state, using SEMs and sessile drop contact angle measurements, as a function of different fabrication techniques: sputtering, pulsed laser deposition (PLD), electrodeposition and annealing Zn. We successfully fabricated (super)hydrophobic ZnO on a mirror finish, commercially available copper substrate using the scalable electrodeposition technique. PLD for ZnO deposition did not prove viable, as the ZnO samples on metal substrates were hydrophilic and the process does not lend itself to scalability. The annealed Zn sheets did not exhibit consistent wetting state results.

Thin-plate spline analysis of craniofacial morphology in subjects with adenoid or tonsillar hypertrophy.

PubMed

Baroni, Michela; Ballanti, Fabiana; Polimeni, Antonella; Franchi, Lorenzo; Cozza, Paola

2011-04-01

To compare the skeletal features of subjects with adenoid hypertrophy with those of children with tonsillar hypertrophy using thin-plate spline (TPS) analysis. A group of 20 subjects (9 girls and 11 boys; mean age 8.4 ± 0.9 years) with adenoid hypertrophy (AG) was compared with a group of 20 subjects (10 girls and 10 boys; mean age 8.2 ± 1.1 years) with tonsillar hypertrophy (TG). Craniofacial morphology was analyzed on the lateral cephalograms of the subjects in both groups by means of TPS analysis. A cross-sectional comparison was performed on both size and shape differences between the two groups. AG exhibited statistically significant shape and size differences in craniofacial configuration with respect to TG. Subjects with adenoid hypertrophy showed an upward dislocation of the anterior region of the maxilla, a more downward/backward position of the anterior region of the mandibular body and an upward/backward displacement of the condylar region. Conversely, subjects with tonsillar hypertrophy showed a downward dislocation of the anterior region of the maxilla, a more upward/forward position of the anterior region of the mandibular body and a downward/forward displacement of the condylar region. Subjects with adenoid hypertrophy exhibited features suggesting a more retrognathic mandible while subjects with tonsillar hypertrophy showed features suggesting a more prognathic mandible. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

Morphological and molecular comparisons between tibialis anterior muscle and levator veli palatini muscle: A preliminary study on their augmentation potential.

PubMed

Cheng, Xu; Song, Lei; Lan, Min; Shi, Bing; Li, Jingtao

2018-01-01

Tibialis anterior (TA) muscle and other somite-derived limb muscles remain the prototype in skeletal muscle study. The majority of head muscles, however, develop from branchial arches and maintain a number of heterogeneities in comparison with their limb counterparts. Levator veli palatini (LVP) muscle is a deep-located head muscle responsible for breathing, swallowing and speech, and is central to cleft palate surgery, yet lacks morphological and molecular investigation. In the present study, multiscale in vivo analyses were performed to compare TA and LVP muscle in terms of their myofiber composition, in-situ stem cell population and augmentation potential. TA muscle was identified to be primarily composed of type 2B myofibers while LVP muscle primarily consisted of type 2A and 2X myofibers. In addition, LVP muscle maintained a higher percentage of centrally-nucleated myofibers and a greater population of satellite cells. Notably, TA and LVP muscle responded to exogenous Wnt7a stimulus in different ways. Three weeks after Wnt7a administration, TA muscle exhibited an increase in myofiber number and a decrease in myofiber size, while LVP muscle demonstrated no significant changes in myofiber number or myofiber size. These results suggested that LVP muscle exhibits obvious differences in comparison with TA muscle. Therefore, knowledge acquired from TA muscle studies requires further testing before being applied to LVP muscle.

Ionic liquid-assisted sonochemical preparation of CeO 2 nanoparticles for CO oxidation

DOE PAGES

Alammar, Tarek; Noei, Heshmat; Wang, Yuemin; ...

2014-10-10

CeO 2 nanoparticles were synthesized via a one-step ultrasound synthesis in different kinds of ionic liquids based on bis(trifluoromethanesulfonylamide, [Tf 2N] –, in combination with various cations including 1-butyl-3-methylimidazolium ([C 4mim] +), 1-ethyl-2,3-dimethylimidazolium ([Edimim] +), butyl-pyridinium([Py 4] +), 1-butyl-1-methyl-pyrrolidinium ([Pyrr 14] +), and 2-hydroxyethyl-trimethylammonium ([N 1112OH] +). Depending on synthetic parameters, such as ionic liquid, Ce(IV) precursor, heating method, and precipitator, formed ceria exhibits different morphologies, varying from nanospheres, nanorods, nanoribbons, and nanoflowers. The morphology, crystallinity, and chemical composition of the obtained materials were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), energy dispersive X-raymore » spectroscopy (EDX), Raman spectroscopy, and N2 adsorption. The structural and electronic properties of the as-prepared CeO 2 samples were probed by CO adsorption using IR spectroscopy under ultrahigh vacuum conditions. The catalytic activities of CeO 2 nanoparticles were investigated in the oxidation of CO. CeO 2 nanospheres obtained sonochemically in [C 4mim][Tf 2N] exhibit the best performance for low-temperature CO oxidation. As a result, the superior catalytic performance of this material can be related to its mesoporous structure, small particle size, large surface area, and high number of surface oxygen vacancy sites.« less

CompCytogen of two of the smallest Amazonian fishes: Fluviphylax simplex Costa, 1996 and Fluviphylax zonatus Costa, 1996 (Cyprinodontiformes, Poeciliidae).

PubMed

Souza, E R; Ribeiro, L B; Feldberg, E; Hrbek, I P Farias T; Gross, M C

2011-01-01

The genus Fluviphylax Whitley, 1965is comprized of five valid species (Fluviphylax pygmaeus Myers et Carvalho, 1955, Fluviphylax zonatus, Fluviphylax simplex, Fluviphylax obscurus Costa, 1996,and Fluviphylax palikur Costa et Le Bail, 1999), which are endemic to the Amazon region. These fishes are the smallest known South American vertebrates and among the smallest know vertebrates on Earth. All species but the type Fluviphylax pygmaeus have been described in late 1990's, and much remains unknown about the biology, taxonomy and systematics of this group of fishes. The aims of the present study were to establish the diploid and haploid number of Fluviphylax zonatus and Fluviphylax simplex, and to find species-specific markers for the discrimination of taxa. The diploid number for both species was 48 chromosomes, with no sex chromosome heteromorphism. Fluviphylax zonatus exhibited the karyotypic formula 4m+8sm+22st+14a and FN=82, and Fluviphylax simplex exhibited 4m+16sm+18st+10a and FN=86. The determination of the total mean length of the chromosomes and their grouping into five size classes demonstrated different chromosome composition of the two species. This difference was further supported by the distribution of constitutive heterochromatin. The meiotic analysis revealed 24 bivalents in both species, but Fluviphylax zonatus exhibited chromosomes with late pairing of the telomeric portions in the pachytene. These data reveal that cytogenetic characterization is useful and important for the discrimination of these species. Our study further indicates that this method could be employed in the analysis of other species of small fishes that are difficult to distinguish using traditional morphological traits or are morphologically cryptic.

Effects of p-(Trifluoromethoxy)benzyl and p-(Trifluoromethoxy)phenyl Molecular Architecture on the Performance of Naphthalene Tetracarboxylic Diimide-Based Air-Stable n-Type Semiconductors.

PubMed

Zhang, Dongwei; Zhao, Liang; Zhu, Yanan; Li, Aiyuan; He, Chao; Yu, Hongtao; He, Yaowu; Yan, Chaoyi; Goto, Osamu; Meng, Hong

2016-07-20

N,N'-Bis(4-trifluoromethoxyphenyl) naphthalene-1,4,5,8-tetracarboxylic acid diimide (NDI-POCF3) and N,N'-bis(4-trifluoromethoxybenzyl) naphthalene-1,4,5,8-tetracarboxylic acid diimide (NDI-BOCF3) have similar optical and electrochemical properties with a deep LUMO level of approximately 4.2 eV, but exhibit significant differences in electron mobility and molecular packing. NDI-POCF3 exhibits nondetectable charge mobility. Interestingly, NDI-BOCF3 shows air-stable electron transfer performance with enhanced mobility by increasing the deposition temperature onto the octadecyltrichlorosilane (OTS)-modified SiO2/Si substrates and achieves electron mobility as high as 0.7 cm(2) V(-1) s(-1) in air. The different mobilities of those two materials can be explained by several factors including thin-film morphology and crystallinity. In contrast to the poor thin-film morphology and crystallinity of NDI-POCF3, NDI-BOCF3 exhibits larger grain sizes and improved crystallinities due to the higher deposition temperature. In addition, the theoretical calculated transfer integrals of the intermolecular lowest unoccupied molecular orbital (LUMO) of the two materials further show that a large intermolecular orbital overlap of NDI-BOCF3 can transfer electron more efficiently than NDI-POCF3 in thin-film transistors. On the basis of fact that the theoretical calculations are consistent with the experimental results, it can be concluded that the p-(trifluoromethoxy) benzyl (BOCF3) molecular architecture on the former position of the naphthalene tetracarboxylic diimides (NDI) core provides a more effective way to enhance the intermolecular electron transfer property than the p-(trifluoromethoxy) phenyl (POCF3) group for the future design of NDI-related air-stable n-channel semiconductor.

Molecular-Scale Structural Controls on Nanoscale Growth Processes: Step-Specific Regulation of Biomineral Morphology

NASA Astrophysics Data System (ADS)

Dove, P. M.; Davis, K. J.; De Yoreo, J. J.; Orme, C. A.

2001-12-01

Deciphering the complex strategies by which organisms produce nanocrystalline materials with exquisite morphologies is central to understanding biomineralizing systems. One control on the morphology of biogenic nanoparticles is the specific interactions of their surfaces with the organic functional groups provided by the organism and the various inorganic species present in the ambient environment. It is now possible to directly probe the microscopic structural controls on crystal morphology by making quantitative measurements of the dynamic processes occurring at the mineral-water interface. These observations can provide crucial information concerning the actual mechanisms of growth that is otherwise unobtainable through macroscopic techniques. Here we use in situ molecular-scale observations of step dynamics and growth hillock morphology to directly resolve roles of principal impurities in regulating calcite surface morphologies. We show that the interactions of certain inorganic as well as organic impurities with the calcite surface are dependent upon the molecular-scale structures of step-edges. These interactions can assume a primary role in directing crystal morphology. In calcite growth experiments containing magnesium, we show that growth hillock structures become modified owing to the preferential inhibition of step motion along directions approximately parallel to the [010]. Compositional analyses have shown that Mg incorporates at different levels into the two types of nonequivalent steps, which meet at the hillock corner parallel to [010]. A simple calculation of the strain caused by this difference indicates that we should expect a significant retardation at this corner, in agreement with the observed development of [010] steps. If the low-energy step-risers produced by these [010] steps is perpendicular to the c-axis as seems likely from crystallographic considerations, this effect provides a plausible mechanism for the elongated calcite crystal habits found in natural environments that contain magnesium. In a separate study, step-specific interactions are also found between chiral aspartate molecules and the calcite surface. The L and D- aspartate enantiomers exhibit structure preferences for the different types of step-risers on the calcite surface. These site-specific interactions result in the transfer of asymmetry from the organic molecule to the crystal surface through the formation of chiral growth hillocks and surface morphologies. These studies yield direct experimental insight into the molecular-scale structural controls on nanocrystal morphology in biomineralizing systems.

Round and pointed-head grenadier fishes (Actinopterygii: Gadiformes) represent a single sister group: evidence from the complete mitochondrial genome sequences.

PubMed

Satoh, Takashi P; Miya, Masaki; Endo, Hiromitsu; Nishida, Mutsumi

2006-07-01

The gene order of mitochondrial genomes (mitogenomes) has been employed as a useful phylogenetic marker in various metazoan animals, because it may represent uniquely derived characters shared by members of monophyletic groups. During the course of molecular phylogenetic studies of the order Gadiformes (cods and their relatives) based on whole mitogenome sequences, we found that two deep-sea grenadiers (Squalogadus modificatus and Trachyrincus murrayi: family Macrouridae) revealed a unusually identical gene order (translocation of the tRNA(Leu (UUR))). Both are members of the same family, although their external morphologies differed so greatly (e.g., round vs. pointed head) that they have been placed in different subfamilies Macrouroidinae and Trachyrincinae, respectively. Additionally, we determined the whole mitogenome sequences of two other species, Bathygadus antrodes and Ventrifossa garmani, representing a total of four subfamilies currently recognized within Macrouridae. The latter two species also exhibited gene rearrangements, resulting in a total of three different patterns of unique gene order being observed in the four subfamilies. Partitioned Bayesian analysis was conducted using available whole mitogenome sequences from five macrourids plus five outgroups. The resultant trees clearly indicated that S. modificatus and T. murrayi formed a monophyletic group, having a sister relationship to other macrourids. Thus, monophyly of the two species with disparate head morphologies was corroborated by two different lines of evidence (nucleotide sequences and gene order). The overall topology of the present tree differed from any of the previously proposed, morphology-based phylogenetic hypotheses.

Triple Hit Lymphoma: Rare Cases With Less Dire Than Usual Prognosis.

PubMed

Kallen, Michael E; Alexanian, Serge; Said, Jonathan; Quintero-Rivera, Fabiola

2016-12-01

Triple hit lymphomas are a subset of so-called double hit non-Hodgkin lymphomas exhibiting simultaneous gene translocations/disruption of MYC, BCL2, and BCL6; however, their overlapping morphologic features and complex genetic rearrangements can render classification and prognostication vexing. Clinically triple hit lymphomas are thought to demonstrate aggressive behavior, similar to or worse than that of double hit lymphomas. Only rare reports of long term survivors exist and raise the possibility that unidentified morphologic, immunologic, or cytogenetic differences may impart a less adverse prognosis than current literature and opinion may suggest. Here we report 3 such cases with less aggressive behavior. Cases such as these may prove useful in comparing outcomes, and underlying mechanisms of tumor progression, in aggressive non-Hodgkin lymphomas. © The Author(s) 2016.

Controlled synthesis of silver nanostructures stabilized by fluorescent polyarylene ether nitrile

NASA Astrophysics Data System (ADS)

Jia, Kun; Shou, Hongguo; Wang, Pan; Zhou, Xuefei; Liu, Xiaobo

2016-07-01

In this work, the intrinsically fluorescent polyarylene ether nitrile (PEN) was explored to realize the controlled synthesis of fluorescent silver nanostructures with different morphology for the first time. Specifically, it was found that silver nitrate (AgNO3) can be effectively reduced to silver nanoparticles using PEN as both reducing and surface capping agents in N, N-dimethylformamide (DMF). More interestingly, the morphology of obtained fluorescent silver nanostructures can be tuned from nanospheres to nanorods by simple variation of reaction time at 130 °C using a relative PEN:AgNO3 molar concentration ratio of 1:8. Meanwhile, the obtained Ag nanostructures exhibited both localized surface plasmon resonance (LSPR) band and fluorescent emission around 420 nm, which would find potential applications in biochemical sensing and optical devices fields.

Characteristics of the cultivable bacteria from sediments associated with two deep-sea hydrothermal vents in Okinawa Trough.

PubMed

Sun, Qing-lei; Wang, Ming-qing; Sun, Li

2015-12-01

In this study, different culture-dependent methods were used to examine the cultivable heterotrophic bacteria in the sediments associated with two deep-sea hydrothermal vents (named HV1 and HV2) located at Iheya Ridge and Iheya North in Okinawa Trough. The two vents differed in morphology, with HV1 exhibiting diffuse flows while HV2 being a black smoker with a chimney-like structure. A total of 213 isolates were identified by near full-length 16S rRNA gene sequence analysis. Of these isolates, 128 were from HV1 and 85 were from HV2. The bacterial community structures were, in large parts, similar between HV1 and HV2. Nevertheless, differences between HV1 and HV2 were observed in one phylum, one class, 4 orders, 10 families, and 20 genera. Bioactivity analysis revealed that 25 isolates belonging to 9 different genera exhibited extracellular protease activities, 21 isolates from 11 genera exhibited extracellular lipase activities, and 13 isolates of 8 genera displayed antimicrobial activities. This is the first observation of a large population of bacteria with extracellular bioactivities existing in deep-sea hydrothermal vents. Taken together, the results of this study provide new insights into the characteristics of the cultivable heterotrophic bacteria in deep-sea hydrothermal ecosystems.

Morphological regulation of Aspergillus niger to improve citric acid production by chsC gene silencing.

PubMed

Sun, Xiaowen; Wu, Hefang; Zhao, Genhai; Li, Zhemin; Wu, Xihua; Liu, Hui; Zheng, Zhiming

2018-04-02

The mycelial morphology of Aspergillus niger, a major filamentous fungus used for citric acid production, is important for citric acid synthesis during submerged fermentation. To investigate the involvement of the chitin synthase gene, chsC, in morphogenesis and citric acid production in A. niger, an RNAi system was constructed to silence chsC and the morphological mutants were screened after transformation. The compactness of the mycelial pellets was obviously reduced in the morphological mutants, with lower proportion of dispersed mycelia. These morphological changes have caused a decrease in viscosity and subsequent improvement in oxygen and mass transfer efficiency, which may be conducive for citric acid accumulation. All the transformants exhibited improvements in citric acid production; in particular, chsC-3 showed 42.6% higher production than the original strain in the shake flask. Moreover, the high-yield strain chsC-3 exhibited excellent citric acid production potential in the scale-up process.The citric acid yield and the conversion rate of glucose of chsC-3 were both improved by 3.6%, when compared with that of the original strain in the stirred tank bioreactor.

A Quantile Regression Approach to Understanding the Relations Among Morphological Awareness, Vocabulary, and Reading Comprehension in Adult Basic Education Students.

PubMed

Tighe, Elizabeth L; Schatschneider, Christopher

2016-07-01

The purpose of this study was to investigate the joint and unique contributions of morphological awareness and vocabulary knowledge at five reading comprehension levels in adult basic education (ABE) students. We introduce the statistical technique of multiple quantile regression, which enabled us to assess the predictive utility of morphological awareness and vocabulary knowledge at multiple points (quantiles) along the continuous distribution of reading comprehension. To demonstrate the efficacy of our multiple quantile regression analysis, we compared and contrasted our results with a traditional multiple regression analytic approach. Our results indicated that morphological awareness and vocabulary knowledge accounted for a large portion of the variance (82%-95%) in reading comprehension skills across all quantiles. Morphological awareness exhibited the greatest unique predictive ability at lower levels of reading comprehension whereas vocabulary knowledge exhibited the greatest unique predictive ability at higher levels of reading comprehension. These results indicate the utility of using multiple quantile regression to assess trajectories of component skills across multiple levels of reading comprehension. The implications of our findings for ABE programs are discussed. © Hammill Institute on Disabilities 2014.

External tufted cells in the main olfactory bulb form two distinct subpopulations.

PubMed

Antal, Miklós; Eyre, Mark; Finklea, Bryson; Nusser, Zoltan

2006-08-01

The glomeruli of the main olfactory bulb are the first processing station of the olfactory pathway, where complex interactions occur between sensory axons, mitral cells and a variety of juxtaglomerular neurons, including external tufted cells (ETCs). Despite a number of studies characterizing ETCs, little is known about how their morphological and functional properties correspond to each other. Here we determined the active and passive electrical properties of ETCs using in vitro whole-cell recordings, and correlated them with their dendritic arborization patterns. Principal component followed by cluster analysis revealed two distinct subpopulations of ETCs based on their electrophysiological properties. Eight out of 12 measured physiological parameters exhibited significant difference between the two subpopulations, including the membrane time constant, amplitude of spike afterhyperpolarization, variance in the interspike interval distribution and subthreshold resonance. Cluster analysis of the morphological properties of the cells also revealed two subpopulations, the most prominent dissimilarity between the groups being the presence or absence of secondary, basal dendrites. Finally, clustering the cells taking all measured properties into account also indicated the presence of two subpopulations that mapped in an almost perfect one-to-one fashion to both the physiologically and the morphologically derived groups. Our results demonstrate that a number of functional and structural properties of ETCs are highly predictive of one another. However, cells within each subpopulation exhibit pronounced variability, suggesting a large degree of specialization evolved to fulfil specific functional requirements in olfactory information processing.

External tufted cells in the main olfactory bulb form two distinct subpopulations

PubMed Central

Antal, Miklós; Eyre, Mark; Finklea, Bryson; Nusser, Zoltan

2006-01-01

The glomeruli of the main olfactory bulb are the first processing station of the olfactory pathway, where complex interactions occur between sensory axons, mitral cells and a variety of juxtaglomerular neurons, including external tufted cells (ETCs). Despite a number of studies characterizing ETCs, little is known about how their morphological and functional properties correspond to each other. Here we determined the active and passive electrical properties of ETCs using in vitro whole-cell recordings, and correlated them with their dendritic arborization patterns. Principal component followed by cluster analysis revealed two distinct subpopulations of ETCs based on their electrophysiological properties. Eight out of 12 measured physiological parameters exhibited significant difference between the two subpopulations, including the membrane time constant, amplitude of spike afterhyperpolarization, variance in the interspike interval distribution and subthreshold resonance. Cluster analysis of the morphological properties of the cells also revealed two subpopulations, the most prominent dissimilarity between the groups being the presence or absence of secondary, basal dendrites. Finally, clustering the cells taking all measured properties into account also indicated the presence of two subpopulations that mapped in an almost perfect one-to-one fashion to both the physiologically and the morphologically derived groups. Our results demonstrate that a number of functional and structural properties of ETCs are highly predictive of one another. However, cells within each subpopulation exhibit pronounced variability, suggesting a large degree of specialization evolved to fulfil specific functional requirements in olfactory information processing. PMID:16930438

Influence of surfactants on the microstructure and electrochemical performance of the tin oxide anode in lithium ion batteries

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sun, Yan-Hui, E-mail: sunyanhui0102@163.com; Guangzhou Key Laboratory of Materials for Energy Conversion and Storage, South China Normal University, Guangzhou 510006; Dong, Pei-Pei

2016-02-15

Highlights: • CTAB and SDS alter the formation of SnO{sub 2} from nanosheets to nanocubes during oxalate precipitation. • The CTAB concentration affects the SnO{sub 2} crystal growth direction, morphology and size. • The SnO{sub 2} anode synthesized using CTAB exhibited superior electrochemical performance. • Proposed a mechanism of influence of surfactant on SnO{sub 2} in the precipitation and annealing process. - Abstract: Different SnO{sub 2} micro–nano structures are prepared by precipitation using a surfactant-assisted process. The surfactants, such as cetyltriethylammonium bromide (CTAB) or sodium dodecyl benzene sulfonate (SDBS), can change the crystal growth direction and microstructure of SnO{sub 2}more » primary and secondary particles. Larger SnO{sub 2} nanosheets were synthesized without surfactant, and micro-fragments composed of small nanospheres or nanocubes were synthesized using CTAB and SDBS. The CTAB-assisted process resulted in smaller primary particles and larger specific surface area and larger pore volume, as a lithium-ion-battery anode that exhibits superior electrochemical performance compared to the other two anodes. Further investigation showed that the concentration of CTAB had a substantial influence on the growth of the crystal face, morphology and size of the SnO{sub 2} secondary particles, which influenced the electrochemical performance of the anode. A simple mechanism for the influence of surfactants on SnO{sub 2} morphology and size in the precipitation and annealing process is proposed.« less

Ordered to isotropic morphology transition in pattern-directed dewetting of polymer thin films on substrates with different feature heights.

PubMed

Roy, Sudeshna; Mukherjee, Rabibrata

2012-10-24

Controlled dewetting of a thin polymer film on a topographically patterned substrate is an interesting approach for aligning isotropic dewetted structures. In this article, we investigate the influence of substrate feature height (H(S)) on the dewetting pathway and final pattern morphology by studying the dewetting of polystyrene (PS) thin films on grating substrates with identical periodicity (λ(P) = 1.5 μm), but H(S) varying between 10 nm and 120 nm. We identify four distinct categories of final dewetted morphology, with different extent of ordering: (1) array of aligned droplets (H(S) ≈ 120 nm); (2) aligned undulating ribbons (H(S) ≈ 70-100 nm); (3) multilength scale structures with coexisting large droplets uncorrelated to the substrate and smaller droplets/ribbons aligned along the stripes (H(S) ≈ 40-60 nm); and (4) large droplets completely uncorrelated to the substrate (H(S) < 25 nm). The distinct morphologies across the categories are attributed to two major factors: (a) whether the as-cast film is continuous (H(S)≤ 80 nm) or discontinuous (H(S)≥ 100 nm) and (b) in case of a continuous film, whether the film ruptures along each substrate stripe (H(S)≥ 70 nm) or with nucleation of random holes that are not correlated to the substrate features (H(S)≤ 60 nm). While the ranges of H(S) values indicated in the parentheses are valid for PS films with an equivalent thickness (h(E)) ≈ 50.3 nm on a flat substrate, a change in h(E) merely alters the cut-off values of H(S), as the final dewetted morphologies and transition across categories remain generically unaltered. We finally show that the structures obtained by dewetting on different H(S) substrates exhibits different levels of hydrophobicity because of combined spatial variation of chemical and topographic contrast along the surface. Thus, the work reported in this article can find potential application in fabricating surfaces with controlled wettability.

Study of the Effect of Nanoparticles and Surface Morphology on Reverse Osmosis and Nanofiltration Membrane Productivity

PubMed Central

Fang, Yuming; Duranceau, Steven J.

2013-01-01

To evaluate the significance of reverse osmosis (RO) and nanofiltration (NF) surface morphology on membrane performance, productivity experiments were conducted using flat-sheet membranes and three different nanoparticles, which included SiO2, TiO2 and CeO2. In this study, the productivity rate was markedly influenced by membrane surface morphology. Atomic force microscopy (AFM) analysis of membrane surfaces revealed that the higher productivity decline rates associated with polyamide RO membranes as compared to that of a cellulose acetate NF membrane was due to the inherent ridge-and-valley morphology of the active layer. The unique polyamide active layer morphology was directly related to the surface roughness, and was found to contribute to particle accumulation in the valleys causing a higher flux decline than in smoother membranes. Extended RO productivity experiments using laboratory grade water and diluted pretreated seawater were conducted to compare the effect that different nanoparticles had on membrane active layers. Membrane flux decline was not affected by particle type when the feed water was laboratory grade water. On the other hand, membrane productivity was affected by particle type when pretreated diluted seawater served as feed water. It was found that CeO2 addition resulted in the least observable flux decline, followed by SiO2 and TiO2. A productivity simulation was conducted by fitting the monitored flux data into a cake growth rate model, where the model was modified using a finite difference method to incorporate surface thickness variation into the analysis. The ratio of cake growth term (k1) and particle back diffusion term (k2) was compared in between different RO and NF membranes. Results indicated that k2 was less significant for surfaces that exhibited a higher roughness. It was concluded that the valley areas of thin-film membrane surfaces have the ability to capture particles, limiting particle back diffusion. PMID:24956946

SSR and morphological trait based population structure analysis of 130 diverse flax (Linum usitatissimum L.) accessions.

PubMed

Choudhary, Shashi Bhushan; Sharma, Hariom Kumar; Kumar, Arroju Anil; Maruthi, Rangappa Thimmaiah; Mitra, Jiban; Chowdhury, Isholeena; Singh, Binay Kumar; Karmakar, Pran Gobinda

2017-02-01

A total of 130 flax accessions of diverse morphotypes and worldwide origin were assessed for genetic diversity and population structure using 11 morphological traits and microsatellite markers (15 gSSRs and 7 EST-SSRs). Analysis performed after classifying these accessions on the basis of plant height, branching pattern, seed size, Indian/foreign origin into six categories called sub-populations viz. fibre type exotic, fibre type indigenous, intermediate type exotic, intermediate type indigenous, linseed type exotic and linseed type indigenous. The study assessed different diversity indices, AMOVA, population structure and included a principal coordinate analysis based on different marker systems. The highest diversity was exhibited by gSSR markers (SI=0.46; He=0.31; P=85.11). AMOVA based on all markers explained significant difference among fibre type, intermediate type and linseed type populations of flax. In terms of variation explained by different markers, EST-SSR markers (12%) better differentiated flax populations compared to morphological (9%) and gSSR (6%) markers at P=0.01. The maximum Nei's unbiased genetic distance (D=0.11) was observed between fibre type and linseed type exotic sub-populations based on EST-SSR markers. The combined structure analysis by using all markers grouped Indian fibre type accessions (63.4%) in a separate cluster along with the Indian intermediate type (48.7%), whereas Indian accessions (82.16%) of linseed type constituted an independent cluster. These findings were supported by the results of the principal coordinate analysis. Morphological markers employed in the study found complementary with microsatellite based markers in deciphering genetic diversity and population structure of the flax germplasm. Copyright © 2016 Académie des sciences. Published by Elsevier Masson SAS. All rights reserved.

Interfacial nanobubbles on atomically flat substrates with different hydrophobicities.

PubMed

Wang, Xingya; Zhao, Binyu; Ma, Wangguo; Wang, Ying; Gao, Xingyu; Tai, Renzhong; Zhou, Xingfei; Zhang, Lijuan

2015-04-07

The dependence of the morphology of interfacial nanobubbles on atomically flat substrates with different wettability ranges was investigated by using PeakForce quantitative nanomechanics. Interfacial nanobubbles were formed and imaged on silicon nitride (Si3N4), mica, and highly ordered pyrolytic graphite (HOPG) substrates that were partly covered by reduced graphene oxide (rGO). The contact angles and sizes of those nanobubbles were measured under the same conditions. Nanobubbles with the same lateral width exhibited different heights on the different substrates, with the order Si3N4≈mica>rGO>HOPG, which is consistent with the trend of the hydrophobicity of the substrates. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Reconstructing the Morphology of an Evolving Coronal Mass Ejection

DTIC Science & Technology

2009-01-01

694, 707 Wood, B. E., Howard, R. A ., Thernisien, A ., Plunkett, S. P., & Socker, D. G. 2009b, Sol. Phys., 259, 163 Wood, B. E., Karovska , M., Chen, J...Reconstructing the Morphology of an Evolving Coronal Mass Ejection B. E. Wood, R. A . Howard, D. G. Socker Naval Research Laboratory, Space Science...mission, we empirically reconstruct the time-dependent three-dimensional morphology of a coronal mass ejection (CME) from 2008 June 1, which exhibits

Effects of transition-metal ions on the morphology and electrochemical properties of δ-MnO2 for supercapacitors

NASA Astrophysics Data System (ADS)

Wang, Jia-Wei; Chen, Ya; Chen, Bai-Zhen

2014-11-01

δ-MnO2 materials doped with transition-metal cations (Zn, Co, and Ag) were successfully synthesized using a hydrothermal technique. The structures and morphologies of the obtained oxides were analyzed using X-ray diffraction, scanning electron microscopy and Brunauer-Emmett-Teller measurements. Additionally, the electrochemical properties were evaluated through cyclic voltammetry, electrochemical impedance spectroscopy and galvanostatic cycling measurements. The results indicate that the pure and doped samples crystallize in the δ form with a layered structure and that the Mn/Zn, Mn/Co and Mn/Ag molar ratios are all approximately 1:0.09. Both the Zn-doped and pure MnO2 materials exhibit a petal-like morphology; however, the former has a higher specific surface area of up to 98.97m2 g-1. Furthermore, the Zn-doped MnO2 exhibits a near-rectangular cyclic voltammetry (CV) curve with broad quasi-reversible redox peaks and a specific capacitance of 182.9 F g-1 at a CV scan rate of 2 mV s-1. The Co-doped material exhibits a distinct spiny-fiber morphology, and the electrochemical performance of this material is significantly worse than that of pure MnO2. The average attenuation rate of the Ag-doped material is only 0.028% after 1000 cycles, which is lower than that of pure MnO2.

Ancestral State Reconstruction Reveals Rampant Homoplasy of Diagnostic Morphological Characters in Urticaceae, Conflicting with Current Classification Schemes

PubMed Central

Wu, Zeng-Yuan; Milne, Richard I.; Chen, Chia-Jui; Liu, Jie; Wang, Hong; Li, De-Zhu

2015-01-01

Urticaceae is a family with more than 2000 species, which contains remarkable morphological diversity. It has undergone many taxonomic reorganizations, and is currently the subject of further systematic studies. To gain more resolution in systematic studies and to better understand the general patterns of character evolution in Urticaceae, based on our previous phylogeny including 169 accessions comprising 122 species across 47 Urticaceae genera, we examined 19 diagnostic characters, and analysed these employing both maximum-parsimony and maximum-likelihood approaches. Our results revealed that 16 characters exhibited multiple state changes within the family, with ten exhibiting >eight changes and three exhibiting between 28 and 40. Morphological synapomorphies were identified for many clades, but the diagnostic value of these was often limited due to reversals within the clade and/or homoplasies elsewhere. Recognition of the four clades comprising the family at subfamily level can be supported by a small number carefully chosen defining traits for each. Several non-monophyletic genera appear to be defined only by characters that are plesiomorphic within their clades, and more detailed work would be valuable to find defining traits for monophyletic clades within these. Some character evolution may be attributed to adaptive evolution in Urticaceae due to shifts in habitat or vegetation type. This study demonstrated the value of using phylogeny to trace character evolution, and determine the relative importance of morphological traits for classification. PMID:26529598

MAJOR-MERGER GALAXY PAIRS AT Z = 0: DUST PROPERTIES AND COMPANION MORPHOLOGY

DOE Office of Scientific and Technical Information (OSTI.GOV)

Domingue, Donovan L.; Ronca, Joseph; Hill, Emily

We present an analysis of dust properties of a sample of close major-merger galaxy pairs selected by K {sub s} magnitude and redshift. The pairs represent the two populations of spiral–spiral (S+S) and mixed morphology spiral–elliptical (S+E). The Code Investigating GALaxy Emission software is used to fit dust models to the Two Micron All Sky Survey, Wide-Field Infrared Survey Explorer , and Herschel flux density measurements, and to derive the parameters describing the polycyclic aromatic hydrocarbons contribution, interstellar radiation field, and photodissociation regions. Model fits verify our previous Spitzer Space Telescope analysis that S+S and S+E pairs do not havemore » the same level of enhancement of star formation and differ in dust composition. The spirals of mixed-morphology galaxy pairs do not exhibit the enhancements in interstellar radiation field and therefore dust temperature for spirals in S+S pairs in contrast to what would be expected according to standard models of gas redistribution due to encounter torques. This suggests the importance of the companion environment/morphology in determining the dust properties of a spiral galaxy in a close major-merger pair.« less

Piscivory limits diversification of feeding morphology in centrarchid fishes.

PubMed

Collar, David C; O'Meara, Brian C; Wainwright, Peter C; Near, Thomas J

2009-06-01

Proximity to an adaptive peak influences a lineage's potential to diversify. We tested whether piscivory, a high quality but functionally demanding trophic strategy, represents an adaptive peak that limits morphological diversification in the teleost fish clade, Centrarchidae. We synthesized published diet data and applied a well-resolved, multilocus and time-calibrated phylogeny to reconstruct ancestral piscivory. We measured functional features of the skull and performed principal components analysis on species' values for these variables. To assess the role of piscivory on morphological diversification, we compared the fit of several models of evolution for each principal component (PC), where model parameters were allowed to vary between lineages that differed in degree of piscivory. According to the best-fitting model, two adaptive peaks influenced PC 1 evolution, one peak shared between highly and moderately piscivorous lineages and another for nonpiscivores. Brownian motion better fit PCs 2, 3, and 4, but the best Brownian models infer a slow rate of PC 2 evolution shared among all piscivores and a uniquely slow rate of PC 4 evolution in highly piscivorous lineages. These results suggest that piscivory limits feeding morphology diversification, but this effect is most severe in lineages that exhibit an extreme form of this diet.

Strong texturing of lithium metal in batteries

DOE PAGES

Shi, Feifei; Pei, Allen; Vailionis, Arturas; ...

2017-10-30

Lithium, with its high theoretical specific capacity and lowest electrochemical potential, has been recognized as the ultimate negative electrode material for next-generation lithium-based high-energy-density batteries. However, a key challenge that has yet to be overcome is the inferior reversibility of Li plating and stripping, typically thought to be related to the uncontrollable morphology evolution of the Li anode during cycling. Here we show that Li-metal texturing (preferential crystallographic orientation) occurs during electrochemical deposition, which governs the morphological change of the Li anode. X-ray diffraction pole-figure analysis demonstrates that the texture of Li deposits is primarily dependent on the type ofmore » additive or cross-over molecule from the cathode side. With adsorbed additives, like LiNO 3 and polysulfide, the lithium deposits are strongly textured, with Li (110) planes parallel to the substrate, and thus exhibit uniform, rounded morphology. A growth diagram of lithium deposits is given to connect various texture and morphology scenarios for different battery electrolytes. In conclusion, this understanding of lithium electrocrystallization from the crystallographic point of view provides significant insight for future lithium anode materials design in high-energy-density batteries.« less

Combining morphometrics with molecular taxonomy: how different are similar foliose keratose sponges from the Australian tropics?

PubMed

Abdul Wahab, M A; Fromont, J; Whalan, S; Webster, N; Andreakis, N

2014-04-01

Sponge taxonomy can be challenging as many groups exhibit extreme morphological plasticity induced by local environmental conditions. Foliose keratose sponges of the sub-family Phyllospongiinae (Dictyoceratida, Thorectidae: Strepsichordaia, Phyllospongia and Carteriospongia) are commonly found in intertidal and subtidal habitats of the Indo-Pacific. Lacking spicules, these sponges can be difficult to differentiate due to the lack of reliable morphological characters for species delineation. We use molecular phylogenies inferred from the nuclear Internal Transcribed Spacer 2 region (ITS2) and morphometrics (19 characters; 52 character states) to identify evolutionarily significant units (ESUs; sensu Moritz) within foliose Phyllosponginiids collected from seven geographic locations across tropical eastern and Western Australia. The ITS2 topology was congruent with the tree derived from Bayesian inference of discrete morphological characters supporting expected taxonomic relationships at the genus level and the identification of five ESUs. However, phylogenies inferred from the ITS2 marker revealed multiple sequence clusters, some of which were characterised by distinct morphological features and specific geographic ranges. Our results are discussed in light of taxonomic incongruences within this study, hidden sponge diversity and the role of vicariant events in influencing present day distribution patterns. Copyright © 2014 Elsevier Inc. All rights reserved.

To feed or to breed: morphological constraints of mouthbrooding in coral reef cardinalfishes

PubMed Central

Hoey, Andrew S.; Bellwood, David R.; Barnett, Adam

2012-01-01

Functionally coupled biomechanical systems are widespread in nature and are viewed as major constraints on evolutionary diversification, yet there have been few attempts to explore the implications of performing multiple functions within a single anatomical structure. Paternally mouthbrooding cardinalfishes present an ideal system to investigate the constraints of functional coupling as the oral jaws of male fishes are directly responsible for both feeding and reproductive functions. To test the effects of (i) mouthbrooding on feeding and (ii) feeding on reproductive potential we compared the feeding apparatus between sexes of nine species of cardinalfish and compared brood characteristics among species from different trophic groups, respectively. Mouthbrooding was strongly associated with the morphology of the feeding apparatus in males. Male cardinalfishes possessed longer heads, snouts and jaws than female conspecifics irrespective of body size, trophic group or evolutionary history. Conversely, reproductive potential also appeared to be related to trophic morphology. Piscivorous cardinalfishes produced larger, but fewer eggs, and had smaller brood volumes than species from the two invertebrate feeding groups. These interrelationships suggest that feeding and reproduction in the mouth of cardinalfishes may be tightly coupled. If so this may, in part, have contributed to the limited morphological diversification exhibited by cardinalfishes. PMID:22319124

The influence of amphiphilic additional agents on the morphology and photoluminescence properties of calcium carbonate phosphor

NASA Astrophysics Data System (ADS)

Mou, Yongren; Kang, Ming; Liu, Min; Wang, Feng; Chen, Kexu; Sun, Rong

2017-06-01

In order to investigate the effect of amphiphilic additional agents on the morphology (particle shape, particle size and particle size distribution) and photoluminescence performance of calcium carbonate phosphor, the phosphors AA-CaCO3:Eu3+ (AA = glycerol or sodium dodecyl sulfate) were synthesized by the microwave-assisted co-precipitation method using glycerol (Gly) and sodium dodecyl sulfate (SDS) as amphiphilic additional agents (AA), respectively. The phase structure, morphology and luminescent properties of the as-synthesized samples were characterized by X-ray diffraction, scanning electron microscope, laser diffraction particle size analyzer and Fluorescence spectrophotometer, respectively. The results showed that the phase structure and morphology of AA-CaCO3:Eu3+ changed along with different types and amount of amphiphilic additional agents evidently. The particle size of Gly-CaCO3 decreased to 1.383 µm when the volume ratio reached 8:2 (Gly:H2O). Photoluminescence (PL) spectra show that all the AA-CaCO3:Eu3+ phosphors exhibit strong red emission peak originating from electric-dipole transition 5D0 → 7F2 (614 nm) of Eu3+ ions and the amphiphilic molecules (Gly and SDS) had a huge influence on photoluminescence intensity.

Morphology informed by phylogeny reveals unexpected patterns of species differentiation in the aquatic moss Rhynchostegium riparioides s.l.

PubMed

Hutsemékers, Virginie; Vieira, Cristiana C; Ros, Rosa María; Huttunen, Sanna; Vanderpoorten, Alain

2012-02-01

Bryophyte floras typically exhibit extremely low levels of endemism. The interpretation, that this might reflect taxonomic shortcomings, is tested here for the Macaronesian flora, using the moss species complex of Rhynchostegium riparioides as a model. The deep polyphyly of R. riparioides across its distribution range reveals active differentiation that better corresponds to geographic than morphological differences. Morphometric analyses are, in fact, blurred by a size gradient that accounts for 80% of the variation observed among gametophytic traits. The lack of endemic diversification observed in R. riparioides in Macaronesia weakens the idea that the low rates of endemism observed in the Macaronesian bryophyte flora might solely be explained by taxonomic shortcomings. To the reverse, the striking polyphyly of North American and European lineages of R. riparioides suggests that the similarity between the floras of these continents has been over-emphasized. Discriminant analyses point to the existence of morphological discontinuities among the lineages resolved by the molecular phylogeny. The global rate of error associated to species identification based on morphology (0.23) indicates, however, that intergradation of shape and size characters among species in the group challenges their identification. Copyright © 2011 Elsevier Inc. All rights reserved.

Strong texturing of lithium metal in batteries

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shi, Feifei; Pei, Allen; Vailionis, Arturas

Lithium, with its high theoretical specific capacity and lowest electrochemical potential, has been recognized as the ultimate negative electrode material for next-generation lithium-based high-energy-density batteries. However, a key challenge that has yet to be overcome is the inferior reversibility of Li plating and stripping, typically thought to be related to the uncontrollable morphology evolution of the Li anode during cycling. Here we show that Li-metal texturing (preferential crystallographic orientation) occurs during electrochemical deposition, which governs the morphological change of the Li anode. X-ray diffraction pole-figure analysis demonstrates that the texture of Li deposits is primarily dependent on the type ofmore » additive or cross-over molecule from the cathode side. With adsorbed additives, like LiNO 3 and polysulfide, the lithium deposits are strongly textured, with Li (110) planes parallel to the substrate, and thus exhibit uniform, rounded morphology. A growth diagram of lithium deposits is given to connect various texture and morphology scenarios for different battery electrolytes. In conclusion, this understanding of lithium electrocrystallization from the crystallographic point of view provides significant insight for future lithium anode materials design in high-energy-density batteries.« less

Where do the 3.5 keV photons come from? A morphological study of the Galactic Center and of Perseus

DOE Office of Scientific and Technical Information (OSTI.GOV)

Carlson, Eric; Jeltema, Tesla; Profumo, Stefano, E-mail: erccarls@ucsc.edu, E-mail: tesla@ucsc.edu, E-mail: profumo@ucsc.edu

We test the origin of the 3.5 keV line photons by analyzing the morphology of the emission at that energy from the Galactic Center and from the Perseus cluster of galaxies. We employ a variety of different templates to model the continuum emission and analyze the resulting radial and azimuthal distribution of the residual emission. We then perform a pixel-by-pixel binned likelihood analysis including line emission templates and dark matter templates and assess the correlation of the 3.5 keV emission with these templates. We conclude that the radial and azimuthal distribution of the residual emission is incompatible with a darkmore » matter origin for both the Galactic center and Perseus; the Galactic center 3.5 keV line photons trace the morphology of lines at comparable energy, while the Perseus 3.5 keV photons are highly correlated with the cluster's cool core, and exhibit a morphology incompatible with dark matter decay. The template analysis additionally allows us to set the most stringent constraints to date on lines in the 3.5 keV range from dark matter decay.« less

Investigation of diseases through red blood cells' shape using photoacoustic response technique

NASA Astrophysics Data System (ADS)

Biswas, Deblina; Gorey, Abhijeet; Chen, Goerge C. K.; Sharma, Norman; Vasudevan, Srivathsan

2015-03-01

Photoacoustic (PA) imaging is a non-invasive real-time technique, widely applied to many biomedical imaging studies in the recent years. While most of these studies have been focussed on obtaining an image after reconstruction, various features of time domain signal (e.g. amplitude, width, rise and relaxation time) would provide very high sensitivity in detecting morphological changes in cells during a biological study. Different haematological disorders (e.g., sickle cell anaemia, thalassemia) exhibit significant morphological cellular changes. In this context, this study explores the possibility of utilizing the developed photoacoustic response technique to apply onto blood samples. Results of our preliminary study demonstrate that there is a significant change in signal amplitude due to change in concentration of the blood. Thus it shows the sensitivity of the developed photoacoustic technique towards red blood cell count (related to haematological disease like anaemia). Subsequently, morphological changes in RBC (i.e. swollen and shrunk compared to normal RBC) induced by hypotonic and hypertonic solutions respectively were also experimented. The result shows a distinct change in PA signal amplitude. This would serve as a diagnostic signature for many future studies on cellular morphological disorders.

To feed or to breed: morphological constraints of mouthbrooding in coral reef cardinalfishes.

PubMed

Hoey, Andrew S; Bellwood, David R; Barnett, Adam

2012-06-22

Functionally coupled biomechanical systems are widespread in nature and are viewed as major constraints on evolutionary diversification, yet there have been few attempts to explore the implications of performing multiple functions within a single anatomical structure. Paternally mouthbrooding cardinalfishes present an ideal system to investigate the constraints of functional coupling as the oral jaws of male fishes are directly responsible for both feeding and reproductive functions. To test the effects of (i) mouthbrooding on feeding and (ii) feeding on reproductive potential we compared the feeding apparatus between sexes of nine species of cardinalfish and compared brood characteristics among species from different trophic groups, respectively. Mouthbrooding was strongly associated with the morphology of the feeding apparatus in males. Male cardinalfishes possessed longer heads, snouts and jaws than female conspecifics irrespective of body size, trophic group or evolutionary history. Conversely, reproductive potential also appeared to be related to trophic morphology. Piscivorous cardinalfishes produced larger, but fewer eggs, and had smaller brood volumes than species from the two invertebrate feeding groups. These interrelationships suggest that feeding and reproduction in the mouth of cardinalfishes may be tightly coupled. If so this may, in part, have contributed to the limited morphological diversification exhibited by cardinalfishes.

Stellar feedback strongly alters the amplification and morphology of galactic magnetic fields

NASA Astrophysics Data System (ADS)

Su, Kung-Yi; Hayward, Christopher C.; Hopkins, Philip F.; Quataert, Eliot; Faucher-Giguère, Claude-André; Kereš, Dušan

2018-01-01

Using high-resolution magnetohydrodynamic simulations of idealized, non-cosmological galaxies, we investigate how cooling, star formation and stellar feedback affect galactic magnetic fields. We find that the amplification histories, saturation values and morphologies of the magnetic fields vary considerably depending on the baryonic physics employed, primarily because of differences in the gas density distribution. In particular, adiabatic runs and runs with a subgrid (effective equation of state) stellar feedback model yield lower saturation values and morphologies that exhibit greater large-scale order compared with runs that adopt explicit stellar feedback and runs with cooling and star formation but no feedback. The discrepancies mostly lie in gas denser than the galactic average, which requires cooling and explicit fragmentation to capture. Independent of the baryonic physics included, the magnetic field strength scales with gas density as B ∝ n2/3, suggesting isotropic flux freezing or equipartition between the magnetic and gravitational energies during the field amplification. We conclude that accurate treatments of cooling, star formation and stellar feedback are crucial for obtaining the correct magnetic field strength and morphology in dense gas, which, in turn, is essential for properly modelling other physical processes that depend on the magnetic field, such as cosmic ray feedback.

Co(II)-doped MOF-5 nano/microcrystals: Solvatochromic behaviour, sensing solvent molecules and gas sorption property

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yang, Ji-Min; School of Chemistry and Chemical Engineering, Linyi University, Linyi 276005; Liu, Qing

2014-10-15

Co(II)-doped MOF-5 nano/microcrystals with controllable morphology and size were successfully obtained by solvothermal method. The products were characterized by powder X-ray diffraction (PXRD), energy dispersive spectrometry (EDS), field emission scanning electron microscopy (FESEM), thermogravimetric analysis (TGA), inductively coupled plasma optical emission spectrometer (ICP-OES), elemental analysis, UV–vis and infrared (IR) spectroscopy. The factors influencing the crystal morphology and size were investigated. The gas sorption measurements reveal that highly crystalline particles have large Langmuir surface area. It was found that the Co(II)-doped MOF-5 shows enhanced hydrostability and the sorption profiles of the Co(II)-doped MOF-5 nano/microcrystals are dependent on the morphology and sizemore » of the particles. Porous Co(II)-doped MOF-5 is stable upon the removal of guest molecules and exhibits different colour with accommodating different solvent molecule, which means that it can act as solvatochromic sensing materials for recognition of solvent molecules. - Graphical abstract: Co(II)-doped MOF-5 nano/microcrystals with different shapes and sizes were synthesized by a facile hydrothermal method, which not only enhance gas sorption properties and structural stability of MOFs towards moisture, but also act as new sensing materials for sensing small molecules. - Highlights: • Co(II)-doped MOF-5 nano/microcrystals with controllable morphology and size were obtained. • Co(II)-doped MOF-5 nano/microcrystals enhance the structural stability towards moisture. • Co(II)-doped MOF-5 can act as new sensing material for sensing small molecules.« less

Temperature-induced plasticity in morphology and relative shell weight in the invasive apple snail Pomacea canaliculata.

PubMed

Tamburi, Nicolás E; Seuffert, María E; Martín, Pablo R

2018-05-01

Temperature has a great influence on the life-history traits of freshwater snails. In this study we investigated the long term effects of a range of temperatures on shell morphology of the apple snail Pomacea canaliculata, a highly invasive species and an important pest of rice. Analysis of shells using geometric morphometrics showed that the main source of morphological variation was allometry, which was detected in males but not in females. This intersexual divergence in allometric trajectories generates much of the morphological variation evidenced. In females, the monotonic relationship with temperature produced narrower shells in the snails reared at lower temperatures, and more expanded apertures, relatively bigger than the body whorl, at higher temperatures. We also found an inverse relationship between relative shell weight, a proxy for shell thickness, and temperature. The differences in shape and relative shell weight are attributable to the different growth rates associated with different temperatures. Temperature fluctuation around a mean of 23.2 °C seemed to have no influence in shell shape and relative weight when is compared with a constant temperature of 25 °C. Information on the influence of temperature on freshwater snails is important for understanding and predicting changes in the face of global climatic change, especially in traits exhibiting great plasticity, such as shell shape and thickness. This work showed that higher temperatures could result in a relatively thinner shell, implying a greater significance of corrosion in flowing waters and a lower resistance to crushing by predators, especially in low latitude areas. Copyright © 2018 Elsevier Ltd. All rights reserved.

Effect of different processes and Ti/Zn molar ratios on the structure, morphology, and enhanced photoelectrochemical and photocatalytic performance of Ti3+ self-doped titanium-zinc hybrid oxides

NASA Astrophysics Data System (ADS)

Fu, Rongrong; Wang, Qingyao; Gao, Shanmin; Wang, Zeyan; Huang, Baibiao; Dai, Ying; Lu, Jun

2015-07-01

Ti3+ self-doped titanium-zinc hybrid oxides with different phase compositions and morphologies were successfully synthesized using Zn powder as the reductant and Zn source by a chemical-reduction precipitation method with subsequent thermal treatment. The fabricated Ti3+ self-doped TiO2(A)/TiO2(R), TiO2(A)/TiO2(R)/ZnTiO3, and TiO2(A)/ZnO heterojunctions were characterized by X-ray diffraction, transmission electron microscopy, high-resolution transmission electron microscopy, X-ray photoelectron spectroscopy, and UV-Vis diffuse reflectance spectroscopy. The effects of various Ti/Zn molar ratios and preparation processes on the structural, morphological, optical, photocurrent and photocatalytic properties of the resultant samples were investigated systematically. Results reveal that Ti3+ self-doping enhances the photoabsorption capability of titanium-zinc hybrid oxides in the visible-light region. Moreover, different processes and Ti/Zn molar ratios play great influences on the structure, morphology, optical, photocurrent and photocatalytic properties of the final products. Ti3+ self-doped titanium-zinc hybrid oxides exhibit excellent photocurrent and photocatalytic activity than pure TiO2 and ZnTiO3 under visible-light irradiation (λ ≥ 400 nm). The most active Ti3+ self-doped titanium-zinc hybrid oxides photoanode presents significantly improved water splitting performance. The synergistic effect between the Ti3+ self-doped and heterojunctions is responsible for the enhanced performance of these materials.

Biomass particle models with realistic morphology and resolved microstructure for simulations of intraparticle transport phenomena

DOE PAGES

Ciesielski, Peter N.; Crowley, Michael F.; Nimlos, Mark R.; ...

2014-12-09

Biomass exhibits a complex microstructure of directional pores that impact how heat and mass are transferred within biomass particles during conversion processes. However, models of biomass particles used in simulations of conversion processes typically employ oversimplified geometries such as spheres and cylinders and neglect intraparticle microstructure. In this study, we develop 3D models of biomass particles with size, morphology, and microstructure based on parameters obtained from quantitative image analysis. We obtain measurements of particle size and morphology by analyzing large ensembles of particles that result from typical size reduction methods, and we delineate several representative size classes. Microstructural parameters, includingmore » cell wall thickness and cell lumen dimensions, are measured directly from micrographs of sectioned biomass. A general constructive solid geometry algorithm is presented that produces models of biomass particles based on these measurements. Next, we employ the parameters obtained from image analysis to construct models of three different particle size classes from two different feedstocks representing a hardwood poplar species ( Populus tremuloides, quaking aspen) and a softwood pine ( Pinus taeda, loblolly pine). Finally, we demonstrate the utility of the models and the effects explicit microstructure by performing finite-element simulations of intraparticle heat and mass transfer, and the results are compared to similar simulations using traditional simplified geometries. In conclusion, we show how the behavior of particle models with more realistic morphology and explicit microstructure departs from that of spherical models in simulations of transport phenomena and that species-dependent differences in microstructure impact simulation results in some cases.« less

Effect of different processes and Ti/Zn molar ratios on the structure, morphology, and enhanced photoelectrochemical and photocatalytic performance of Ti3+ self-doped titanium–zinc hybrid oxides

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fu, Rongrong; Wang, Qingyao; Gao, shanmin

2015-07-01

Ti3+ self-doped titanium–zinc hybrid oxides with different phase compositions and morphologies were successfully synthesized using Zn powder as the reductant and Zn source by a chemical-reduction precipitation method with subsequent thermal treatment. The fabricated Ti3+ self-doped TiO2(A)/TiO2(R), TiO2(A)/TiO2(R)/ZnTiO3, and TiO2(A)/ZnO heterojunctions were characterized by X-ray diffraction, transmission electron microscopy, high-resolution transmission electron microscopy, X-ray photoelectron spectroscopy, and UV–Vis diffuse reflectance spectroscopy. The effects of various Ti/Zn molar ratios and preparation processes on the structural, morphological, optical, photocurrent and photocatalytic properties of the resultant samples were investigated systematically. Results reveal that Ti3+ self-doping enhances the photoabsorption capability of titanium–zinc hybrid oxidesmore » in the visible-light region. Moreover, different processes and Ti/Zn molar ratios play great influences on the structure, morphology, optical, photocurrent and photocatalytic properties of the final products. Ti3+ self-doped titanium–zinc hybrid oxides exhibit excellent photocurrent and photocatalytic activity than pure TiO2 and ZnTiO3 under visible-light irradiation (λ ≥ 400 nm). The most active Ti3+ self-doped titanium–zinc hybrid oxides photoanode presents significantly improved water splitting performance. The synergistic effect between the Ti3+ self-doped and heterojunctions is responsible for the enhanced performance of these materials.« less

The Feeding Biomechanics and Dietary Ecology of Paranthropus boisei

PubMed Central

Smith, Amanda L.; Benazzi, Stefano; Ledogar, Justin A.; Tamvada, Kelli; Pryor Smith, Leslie C.; Weber, Gerhard W.; Spencer, Mark A.; Lucas, Peter W.; Michael, Shaji; Shekeban, Ali; Al-Fadhalah, Khaled; Almusallam, Abdulwahab S.; Dechow, Paul C.; Grosse, Ian R.; Ross, Callum F.; Madden, Richard H.; Richmond, Brian G.; Wright, Barth W.; Wang, Qian; Byron, Craig; Slice, Dennis E.; Wood, Sarah; Dzialo, Christine; Berthaume, Michael A.; Casteren, Adam Van; Strait, David S.

2015-01-01

The African Plio-Pleistocene hominins known as australopiths evolved derived craniodental features frequently interpreted as adaptations for feeding on either hard, or compliant/tough foods. Among australopiths, Paranthropus boisei is the most robust form, exhibiting traits traditionally hypothesized to produce high bite forces efficiently and strengthen the face against feeding stresses. However, recent mechanical analyses imply that P. boisei may not have been an efficient producer of bite force and that robust morphology in primates is not necessarily strong. Here we use an engineering method, finite element analysis, to show that the facial skeleton of P. boisei is structurally strong, exhibits a strain pattern different from that in chimpanzees (Pan troglodytes) and Australopithecus africanus, and efficiently produces high bite force. It has been suggested that P. boisei consumed a diet of compliant/tough foods like grass blades and sedge pith. However, the blunt occlusal topography of this and other species suggests that australopiths are adapted to consume hard foods, perhaps including grass and sedge seeds. A consideration of evolutionary trends in morphology relating to feeding mechanics suggests that food processing behaviors in gracile australopiths evidently were disrupted by environmental change, perhaps contributing to the eventual evolution of Homo and Paranthropus. PMID:25529240

Synergistic tungsten oxide/organic framework hybrid nanofibers for electrochromic device application

NASA Astrophysics Data System (ADS)

Dulgerbaki, Cigdem; Komur, Ali Ihsan; Nohut Maslakci, Neslihan; Kuralay, Filiz; Uygun Oksuz, Aysegul

2017-08-01

We report the first successful applications of tungsten oxide/conducting polymer hybrid nanofiber assemblies in electrochromic devices. Poly(3,4-ethylenedioxythiophene)/tungsten oxide (PEDOT/WO3) and polypyrrole/tungsten oxide (PPy/WO3) composites were prepared by an in situ chemical oxidative polymerization of monomers in different ionic liquids; 1-butyl-3-methylimidazolium tetrafluoroborate (BMIMBF4), 1-butyl-3-methylimidazolium hexafluorophosphate (BMIMPF6), 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl) imide (BMIMTFSI) and 1-butyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl) imide (BMPTFSI). Electrospinning process was used to form hybrid nanofibers from chemically synthesized nanostructures. The electrospun hybrid samples were compared from both morphological and electrochemical perspectives. Importantly, deposition of nanofibers from chemically synthesized hybrids can be achieved homogenously, on nanoscale dimensions. The morphologies of these assemblies were evaluated by SEM, whereas their electroactivity was characterized by cyclic voltammetry. Electrochromic devices made from hybrid nanofiber electrodes exhibited highest chromatic contrast of 37.66% for PEDOT/WO3/BMIMPF6, 40.42% for PPy/WO3/BMIMBF4 and show a strong electrochromic color change from transparent to light brown. Furthermore, the nanofiber devices exhibit outstanding stability when color switching proceeds, which may ensure a versatile platform for color displays, rear-view mirrors and smart windows.

Emphasizing the role of surface chemistry on hydrophobicity and cell adhesion behavior of polydimethylsiloxane/TiO2 nanocomposite films.

PubMed

Yousefi, Seyedeh Zahra; Tabatabaei-Panah, Pardis-Sadat; Seyfi, Javad

2018-07-01

Improving the bioinertness of materials is of great importance for developing biomedical devices that contact human tissues. The main goal of this study was to establish correlations among surface morphology, roughness and chemistry with hydrophobicity and cell adhesion in polydimethylsiloxane (PDMS) nanocomposites loaded with titanium dioxide (TiO 2 ) nanoparticles. Firstly, wettability results showed that the nanocomposite loaded with 30 wt.% of TiO 2 exhibited a superhydrophobic behavior; however, the morphology and roughness analysis proved that there was no discernible difference between the surface structures of samples loaded with 20 and 30 wt.% of nanoparticles. Both cell culture and MTT assay experiments showed that, despite the similarity between the surface structures, the sample loaded with 30 wt.% nanoparticles exhibits the greatest reduction in the cell viability (80%) as compared with the pure PDMS film. According to the X-ray photoelectron spectroscopy results, the remarkable reduction in cell viability of the superhydrophobic sample could be majorly attributed to the role of surface chemistry. The obtained results emphasize the importance of adjusting the surface properties especially surface chemistry to gain the optimum cell adhesion behavior. Copyright © 2018 Elsevier B.V. All rights reserved.

Water Stress Affects Development Time but Not Takeoff Performance in the Butterfly Pararge aegeria.

PubMed

Lailvaux, Simon P; Breuker, Casper J; Van Damme, Raoul

Most organisms are limited in the amount and type of resources they are able to extract from the environment. The juvenile environment is particularly important in this regard, as conditions over ontogeny can influence the adult phenotype. Whole-organism performance traits, such as locomotion, are susceptible to such environmental effects, yet the specific biotic and abiotic factors driving performance plasticity have received little attention. We tested whether speckled wood Pararge aegeria L. butterflies reared under conditions of water stress exhibited poorer flight morphology and performance than control individuals. Despite large differences in mortality between treatments, we found no effects of water stress treatment on takeoff performance and only minor treatment effects on flight morphology. However, butterflies reared on water-stressed diets exhibited both significantly greater mortality and longer development times than did control individuals. Pararge aegeria larvae may compensate for this stress by prolonging development, resulting in similar realized performance capacities at least in takeoff performance in surviving adult butterflies; other measures of flight performance remain to be considered. Alternatively, the adult phenotype may be insulated from environmental effects at the larval stage in these insects.

Morphology Instruction in the Science Classroom for Students Who Are Deaf: A Multiple Probe Across Content Analysis.

PubMed

Trussell, Jessica W; Nordhaus, Jason; Brusehaber, Alison; Amari, Brittany

2018-04-17

Deaf and hard-of-hearing (DHH) students have exhibited a morphological knowledge delay that begins in preschool and persists through college. Morphological knowledge is critical to vocabulary understanding and text comprehension in the science classroom. We investigated the effects of morphological instruction, commonly referred to as Word Detectives, on the morphological knowledge of college-age DHH students in a science course. We implemented a multiple probe across behaviors single-case experimental design study with nine student participants. The student participants attended the National Technical Institute for the Deaf. A functional relation was found between the morphological instruction and the student participants' improvement of morphological knowledge regarding the morphemes taught during instruction. These findings indicate that DHH students benefit from morphological instruction to build their vocabulary knowledge in content-area classrooms, such as science courses.

Analysis of the internal anatomy of maxillary first molars by using different methods.

PubMed

Baratto Filho, Flares; Zaitter, Suellen; Haragushiku, Gisele Aihara; de Campos, Edson Alves; Abuabara, Allan; Correr, Gisele Maria

2009-03-01

The success of endodontic treatment depends on the identification of all root canals so that they can be cleaned, shaped, and obturated. This study investigated internal morphology of maxillary first molars by 3 different methods: ex vivo, clinical, and cone beam computed tomography (CBCT) analysis. In all these different methods, the number of additional root canals and their locations, the number of foramina, and the frequency of canals that could or could not be negotiated were recorded. In the ex vivo study, 140 extracted maxillary first molars were evaluated. After canals were accessed and detected by using an operating microscope, the teeth with significant anatomic variances were cleared. In the clinical analysis, the records of 291 patients who had undergone endodontic treatment in a dental school during a 2-year period were used. In the CBCT analysis, 54 maxillary first molars were evaluated. The ex vivo assessment results showed a fourth canal frequency in 67.14% of the teeth, besides a tooth with 7 root canals (0.72%). Additional root canals were located in the mesiobuccal root in 92.85% of the teeth (17.35% could not be negotiated), and when they were present, 65.30% exhibited 1 foramen. Clinical assessment showed that 53.26%, 0.35%, and 0.35% of the teeth exhibited 4, 5, and 6 root canals, respectively. Additional root canals were located in this assessment in mesiobuccal root in 95.63% (27.50% could not be negotiated), and when they were present, 59.38% exhibited 1 foramen. CBCT results showed 2, 4, and 5 root canals in 1.85%, 37.05%, and 1.85% of the teeth, respectively. When present, additional canals showed 1 foramen in 90.90% of the teeth studied. This study demonstrated that operating microscope and CBCT have been important for locating and identifying root canals, and CBCT can be used as a good method for initial identification of maxillary first molar internal morphology.

Morphological and clinical findings in Sri Lankan patients with chronic kidney disease of unknown cause (CKDu): Similarities and differences with Mesoamerican Nephropathy.

PubMed

Wijkström, Julia; Jayasumana, Channa; Dassanayake, Rajeewa; Priyawardane, Nalin; Godakanda, Nimali; Siribaddana, Sisira; Ring, Anneli; Hultenby, Kjell; Söderberg, Magnus; Elinder, Carl-Gustaf; Wernerson, Annika

2018-01-01

In Sri Lanka, an endemic of chronic kidney disease of unknown origin (CKDu) is affecting rural communities. The endemic has similarities with Mesoamerican Nephropathy (MeN) in Central America, however it has not yet been clarified if the endemics are related diagnostic entities. We designed this study of kidney biopsies from patients with CKDu in Sri Lanka to compare with MeN morphology. Eleven patients with CKDu were recruited at the General Hospital, Polonnaruwa, using similar inclusion and exclusion criteria as our previous MeN studies. Inclusion criteria were 20-65 years of age and plasma creatinine 100-220 μmol/L. Exclusion criteria were diabetes mellitus, uncontrolled hypertension and albuminuria >1g/24h. Kidney biopsies, blood and urine samples were collected, and participants answered a questionnaire. Included participants were between 27-61 years of age and had a mean eGFR of 38±14 ml/min/1.73m2. Main findings in the biopsies were chronic glomerular and tubulointerstitial damage with glomerulosclerosis (8-75%), glomerular hypertrophy and mild to moderate tubulointerstitial changes. The morphology was more heterogeneous and interstitial inflammation and vascular changes were more common compared to our previous studies of MeN. In two patients the biopsies showed morphological signs of acute pyelonephritis but urine cultures were negative. Electrolyte disturbances with low levels of serum sodium, potassium, and/or magnesium were common. In the urine, only four patients displayed albuminuria, but many patients exhibited elevated α-1-microglobulin and magnesium levels. This is the first study reporting detailed biochemical and clinical data together with renal morphology, including electron microscopy, from Sri Lankan patients with CKDu. Our data show that there are many similarities in the biochemical and morphological profile of the CKDu endemics in Central America and Sri Lanka, supporting a common etiology. However, there are differences, such as a more mixed morphology, more interstitial inflammation and vascular changes in Sri Lankan patients.

Morphology meets molecules: a new genus and two new species of diphyllidean cestodes from the Yellowspotted skate, Leucoraja wallacei, from South Africa.

PubMed

Abbott, Lauren McKenna; Caira, Janine N

2014-06-01

Two morphologically disparate undescribed species of diphyllidean cestodes from the Yellowspotted skate, Leucoraja wallacei , from South Africa were included in a recent molecular phylogenetic study aimed at revising diphyllidean classification. From a molecular standpoint, these species were determined to be only distantly related to one another. One (originally referred to as Echinobothrium n. sp. 2) showed affinities with species of the batoid-parasitizing Echinobothrium sensu stricto and is described here as Echinobothrium marquesi n. sp. This species most closely resembles Echinobothrium joshuai, an affinity supported by the previous molecular study, but differs in the form of its "B" hooks and degree of overlap between bothria and cephalic peduncle. The other species (originally referred to as New genus n. sp. 1), although exhibiting the full complement of scolex armature, grouped among primarily shark-hosted genera, most of which lack or exhibit reduced scolex armatures. That unexpected result suggested that erection of a novel genus might be warranted, but morphological grounds supporting the action were not apparent at that time. The present study aimed to explore the morphology of this taxon in more detail. Light and scanning electron microscopy revealed this taxon to be exceptional in that its lateral hooklets, which are arranged in 2 clusters like those of Echinobothrium and Coronocestus, are unique in being arranged in anterior and posterior rows, rather than in a single row. Andocadoncum n. gen. is erected, with Andocadoncum meganae n. sp. as its type, to accommodate this taxon. A minor adjustment to the existing hook formula by presenting counts for the anterior hooklets (a) separately from the posterior hooklets (b) readily accommodates this new form. Leucoraja wallacei is distinctive among skates in hosting 2 different genera of diphyllideans. In the context of the previous molecular phylogenetic analyses, it appears that the presence of Andocadoncum n. gen. in this skate species may be the result of a host-switching event involving a weakly or unarmed shark-hosted taxon moving to a batoid-a shift that was likely accompanied by a return to the fully armed condition seen, for example, in other batoid-parasitizing members of the order.

Data on morphological features of mycosis induced by Colletotrichum nymphaeae and Lecanicillium longisporum on citrus orthezia scale.

PubMed

Mascarin, Gabriel Moura; Guarín-Molina, Juan Humberto; Arthurs, Steven Paul; Humber, Richard Alan; de Andrade Moral, Rafael; Demétrio, Clarice Garcia Borges; Delalibera, Ítalo

2016-09-01

We describe symptoms of mycosis induced by two native fungal entomopathogens of the citrus orthezia scale, Praelongorthezia praelonga (Hemiptera: Ortheziidae), an important pest of citrus orchards. The data presented in this article are related to the article entitled "Seasonal prevalence of the insect pathogenic fungus Colletotrichum nymphaeae in Brazilian citrus groves under different chemical pesticide regimes" [1]. The endemic fungal pathogen, C. nymphaeae, emerges through the thin cuticular intersegmental regions of the citrus orthezia scale body revealing orange salmon-pigmented conidiophores bearing conidial masses, as well as producing rhizoid-like hyphae that extend over the citrus leaf. By contrast, nymphs or adult females of this scale insect infected with Lecanicillium longisporum exhibit profuse outgrowth of bright white-pigmented conidiophores with clusters of conidia emerging from the insect intersegmental membranes, and mycosed cadavers are commonly observed attached to the leaf surface by hyphal extensions. These morphological differences are important features to discriminate these fungal entomopathogens in citrus orthezia scales.

Effect of different Zr contents on properties and microstructure of Cu-Cr-Zr alloys

NASA Astrophysics Data System (ADS)

Jinshui, Chen; Bin, Yang; Junfeng, Wang; Xiangpeng, Xiao; Huiming, Chen; Hang, Wang

2018-02-01

The crystallography and morphology of precipitate particles of Cu-Cr-Zr alloys with varying Zr contents were studied by transmission electron microscopy (TEM) after solution treatments at 950 °C for 1 h and aging treatments at 500 °C for different times ranged from 0.5 h to 24 h. The microhardness and electrical conductivity of Cu-Cr-Zr alloys after various aging process were tested. The results show that the microhardness and electrical conductivity rapidly increased at first, then the microhardness decreased slowly after reaching the peak, while the conductivity continues to increase. Nano-scaled precipitates exhibit two kinds of morphology (coffee bean and ellipse shaped). With increasing Zr content, the Zr-containing precipitation sequence of Cu-Cr-Zr alloys at peak-ageing is Heusler CrCu2Zr → Cu5Zr → Cu4Zr. The Heusler CrCu2Zr phase decomposed into fine and homogeneous Cr and Cu4Zr, resulting in improved alloy properties.

The Deposition of Electro-Optic Films on Semiconductors

DTIC Science & Technology

1993-10-08

Electro - optic properties of KNbO3 films on MgO are found to be similar to bulk, although the scattering losses are very high for these films. In comparison KNbO3 films grown on KTaO3 exhibit low losses of less than 8 dB, while losses for films on spinel showed to be in between those two. The variety of substrates provide us with differences in lattice mismatch, refractive index mismatch, surface morphologies, and microstructure, all of which influence loss

Characterization of aluminum selenide bi-layer thin film

NASA Astrophysics Data System (ADS)

Boolchandani, Sarita; Soni, Gyanesh; Srivastava, Subodh; Vijay, Y. K.

2018-05-01

The Aluminum Selenide (AlSe) bi-layer thin films were grown on glass substrate using thermal evaporation method under high vacuum condition. The morphological characterization was done using SEM. Electrical measurement with temperature variation shows that thin films exhibit the semiconductor nature. The optical properties of prepared thin films have also been characterized by UV-VIS spectroscopy measurements. The band gap of composite thin films has been calculated by Tauc's relation at different temperature ranging 35°C-100°C.

Transitional phase inversion of emulsions monitored by in situ near-infrared spectroscopy.

PubMed

Charin, R M; Nele, M; Tavares, F W

2013-05-21

Water-heptane/toluene model emulsions were prepared to study emulsion transitional phase inversion by in situ near-infrared spectroscopy (NIR). The first emulsion contained a small amount of ionic surfactant (0.27 wt % of sodium dodecyl sulfate) and n-pentanol as a cosurfactant. In this emulsion, the study was guided by an inversion coordinate route based on a phase behavior study previously performed. The morphology changes were induced by rising aqueous phase salinity in a "steady-state" inversion protocol. The second emulsion contained a nonionic surfactant (ethoxylated nonylphenol) at a concentration of 3 wt %. A continuous temperature change induced two distinct transitional phase inversions: one occurred during the heating of the system and another during the cooling. NIR spectroscopy was able to detect phase inversion in these emulsions due to differences between light scattered/absorbed by water in oil (W/O) and oil in water (O/W) morphologies. It was observed that the two model emulsions exhibit different inversion mechanisms closely related to different quantities of the middle phases formed during the three-phase behavior of Winsor type III.

Sequential Markov chain Monte Carlo filter with simultaneous model selection for electrocardiogram signal modeling.

PubMed

Edla, Shwetha; Kovvali, Narayan; Papandreou-Suppappola, Antonia

2012-01-01

Constructing statistical models of electrocardiogram (ECG) signals, whose parameters can be used for automated disease classification, is of great importance in precluding manual annotation and providing prompt diagnosis of cardiac diseases. ECG signals consist of several segments with different morphologies (namely the P wave, QRS complex and the T wave) in a single heart beat, which can vary across individuals and diseases. Also, existing statistical ECG models exhibit a reliance upon obtaining a priori information from the ECG data by using preprocessing algorithms to initialize the filter parameters, or to define the user-specified model parameters. In this paper, we propose an ECG modeling technique using the sequential Markov chain Monte Carlo (SMCMC) filter that can perform simultaneous model selection, by adaptively choosing from different representations depending upon the nature of the data. Our results demonstrate the ability of the algorithm to track various types of ECG morphologies, including intermittently occurring ECG beats. In addition, we use the estimated model parameters as the feature set to classify between ECG signals with normal sinus rhythm and four different types of arrhythmia.

Investigations on diamond nanostructuring of different morphologies by the reactive-ion etching process and their potential applications.

PubMed

Kunuku, Srinivasu; Sankaran, Kamatchi Jothiramalingam; Tsai, Cheng-Yen; Chang, Wen-Hao; Tai, Nyan-Hwa; Leou, Keh-Chyang; Lin, I-Nan

2013-08-14

We report the systematic studies on the fabrication of aligned, uniform, and highly dense diamond nanostructures from diamond films of various granular structures. Self-assembled Au nanodots are used as a mask in the self-biased reactive-ion etching (RIE) process, using an O2/CF4 process plasma. The morphology of diamond nanostructures is a close function of the initial phase composition of diamond. Cone-shaped and tip-shaped diamond nanostructures result for microcrystalline diamond (MCD) and nanocrystalline diamond (NCD) films, whereas pillarlike and grasslike diamond nanostructures are obtained for Ar-plasma-based and N2-plasma-based ultrananocrystalline diamond (UNCD) films, respectively. While the nitrogen-incorporated UNCD (N-UNCD) nanograss shows the most-superior electron-field-emission properties, the NCD nanotips exhibit the best photoluminescence properties, viz, different applications need different morphology of diamond nanostructures to optimize the respective characteristics. The optimum diamond nanostructure can be achieved by proper choice of granular structure of the initial diamond film. The etching mechanism is explained by in situ observation of optical emission spectrum of RIE plasma. The preferential etching of sp(2)-bonded carbon contained in the diamond films is the prime factor, which forms the unique diamond nanostructures from each type of diamond films. However, the excited oxygen atoms (O*) are the main etching species of diamond film.

Craniofacial and pharyngeal airway morphology in patients with acromegaly.

PubMed

Balos Tuncer, Burcu; Canigur Bavbek, Nehir; Ozkan, Cigdem; Tuncer, Cumhur; Eroglu Altinova, Alev; Gungor, Kahraman; Akturk, Mujde; Balos Toruner, Fusun

2015-08-01

The aim of this study was to assess differences in craniofacial characteristics, upper spine and pharyngeal airway morphology in patients with acromegaly compared with healthy individuals. Twenty-one patients with acromegaly were compared with 22 controls by linear and angular measurements on cephalograms. The differences between the mean values of cephalometric parameters were analyzed with Mann-Whitney U-test. With respect to controls, anterior (p<0.05), middle (p<0.01) and posterior (p<0.05) cranial base lengths were increased, sella turcica was enlarged (p<0.001) and upper spine morphology demonstrated differences in the height of atlas (p<0.01) and axis (p<0.05) in patients with acromegaly. Craniofacial changes were predominantly found in the frontal bone (p<0.01) and the mandible (p<0.05). As for the airway, patients with acromegaly exhibited diminished dimensions at nasal (p<0.001), uvular (p<0.01), mandibular (p<0.01) pharyngeal levels and at the narrowest point of the pharyngeal airway space (p<0.001) compared to healthy controls. Soft palate width was significantly higher (p<0.001) and the hyoid bone was more vertically positioned (p<0.01) in patients with acromegaly. Current results point to the importance of the reduced airway dimensions and that dentists and/or orthodontists should be aware of the cranial or dental abnormalities in patients with acromegaly.

Erratum to: Morphometric analysis of Passiflora leaves: the relationship between landmarks of the vasculature and elliptical Fourier descriptors of the blade.

PubMed

Chitwood, Daniel H; Otoni, Wagner C

2017-10-01

Leaf shape among Passiflora species is spectacularly diverse. Underlying this diversity in leaf shape are profound changes in the patterning of the primary vasculature and laminar outgrowth. Each of these aspects of leaf morphology-vasculature and blade-provides different insights into leaf patterning. Here, we morphometrically analyze >3300 leaves from 40 different Passiflora species collected sequentially across the vine. Each leaf is measured in two different ways: using 1) 15 homologous Procrustes-adjusted landmarks of the vasculature, sinuses, and lobes; and 2) Elliptical Fourier Descriptors (EFDs), which quantify the outline of the leaf. The ability of landmarks, EFDs, and both datasets together are compared to determine their relative ability to predict species and node position within the vine. Pairwise correlation of x and y landmark coordinates and EFD harmonic coefficients reveals close associations between traits and insights into the relationship between vasculature and blade patterning. Landmarks, more reflective of the vasculature, and EFDs, more reflective of the blade contour, describe both similar and distinct features of leaf morphology. Landmarks and EFDs vary in ability to predict species identity and node position in the vine and exhibit a correlational structure (both within landmark or EFD traits and between the two data types) revealing constraints between vascular and blade patterning underlying natural variation in leaf morphology among Passiflora species. © The Authors 2017. Published by Oxford University Press.

Morphometric analysis of Passiflora leaves: the relationship between landmarks of the vasculature and elliptical Fourier descriptors of the blade.

PubMed

Chitwood, Daniel H; Otoni, Wagner C

2017-01-01

Leaf shape among Passiflora species is spectacularly diverse. Underlying this diversity in leaf shape are profound changes in the patterning of the primary vasculature and laminar outgrowth. Each of these aspects of leaf morphology-vasculature and blade-provides different insights into leaf patterning. Here, we morphometrically analyze >3300 leaves from 40 different Passiflora species collected sequentially across the vine. Each leaf is measured in two different ways: using 1) 15 homologous Procrustes-adjusted landmarks of the vasculature, sinuses, and lobes; and 2) Elliptical Fourier Descriptors (EFDs), which quantify the outline of the leaf. The ability of landmarks, EFDs, and both datasets together are compared to determine their relative ability to predict species and node position within the vine. Pairwise correlation of x and y landmark coordinates and EFD harmonic coefficients reveals close associations between traits and insights into the relationship between vasculature and blade patterning. Landmarks, more reflective of the vasculature, and EFDs, more reflective of the blade contour, describe both similar and distinct features of leaf morphology. Landmarks and EFDs vary in ability to predict species identity and node position in the vine and exhibit a correlational structure (both within landmark or EFD traits and between the two data types) revealing constraints between vascular and blade patterning underlying natural variation in leaf morphology among Passiflora species. © The Author 2017. Published by Oxford University Press.

Morphological and molecular characterization of Isospora neochmiae n. sp. in a captive-bred red-browed finch (Neochmia temporalis) (Latham, 1802).

PubMed

Yang, Rongchang; Brice, Belinda; Ryan, Una

2016-07-01

A new Isospora (Apicomplexa: Eimeriidae) species is described from a single red-browed finch (Neochmia temporalis) (subspecies N. temporalis temporalis), that was part of a captive population in Western Australia. Sporulated oocysts of this isolate are spherical, 18.3 (18.2-18.9) × 18.2 (18.2-18.6) μm, with a shape index (length/width) of 1.0; and a smooth and bilayered oocyst wall, 1.2 μm thick (outer layer 0.9 μm, inner 0.3 μm). A polar granule is present, but the oocyst residuum and a micropyle are absent. The sporocysts are ovoid-shaped, 13.3 (9.5-16.4) × 8.6 (6.8-10.0) μm, with a shape index of 1.5. An indistinct Stieda body is present, but the substieda body is absent. A sporocyst residuum is present and composed of numerous granules of different size scattered among the sporozoites. Morphologically, the oocysts from this isolate are different from those of all known valid Isospora spp. Molecular analysis was conducted at 4 loci; the 18S and 28S ribosomal RNA (rRNA), the mitochondrial cytochrome oxidase (COI) gene and the heat shock protein 70 (hsp70) gene. At the 18S locus, this new isolate exhibited 99.9%, 99.8%, 99.7%, and 99.5% similarity to I. sp. MAH-2013a from a superb starling (Lamprotornis superbus), I. MS-2003 from a Southern cape sparrow (Passer melanurus), I. sp. Tokyo from a domestic pigeon (Columba livia domestica) and I. MS-2003 from a Surinam crested oropendula (Psarocolius decumanus). At the 28S locus, this new isolate exhibited 99.7% similarity to both an Isospora sp (MS-2003) from a Northern house sparrow (Passer domesticus) and an Isospora sp. (MS-2003) from a Southern cape sparrow. At the COI locus, this new isolate exhibited 98.9% similarity to an Isospora sp. ex Apodemus flavicollis. At the hsp70 locus, this new isolate exhibited 99% similarity to isolate MS-2003 (AY283879) from a wattled starling (Creatophora cinerea). Based on morphological and molecular data, this isolate is a new species of Isospora, which is named Isospora neochmiae n. sp. after its host, the red-browed finch (Neochmia temporalis). Crown Copyright © 2016. Published by Elsevier Inc. All rights reserved.

Hierarchically Flower-like N-Doped Porous Carbon Materials Derived from an Explosive 3-Fold Interpenetrating Diamondoid Copper Metal-Organic Framework for a Supercapacitor.

PubMed

Li, Zuo-Xi; Zou, Kang-Yu; Zhang, Xue; Han, Tong; Yang, Ying

2016-07-05

A peculiar copper metal-organic framework (Cu-MOF) was synthesized by a self-assembly method, which presents a 3-fold interpenetrating diamondoid net based on the square-planar Cu(II) node. Although it exhibits a high degree of interpenetration, the Cu-MOF still exhibits a one-dimensional channel, which provides a template for constructing porous materials through the "precursor" strategy. Furthermore, the explosive ClO4(-) ion, which resided in the channel, could induce the quick decomposition of organic ingredients and release a huge amount of gas, which is beneficial for the porosity of postsynthetic materials. Significantly, we first utilize this explosive MOF to prepare a series of Cu@C composites through the calcination-thermolysis method at different temperatures, which contain copper particles exhibiting various shapes and combinations with the carbon substrate. Considering the hole-forming effect of copper particles, Cu@C composites were etched by HCl to afford a sequence of hierarchically flower-like N-doped porous carbon materials (NPCs), which retain the original morphology of the Cu-MOF. Interestingly, NPC-900, originating from the calcination of the Cu-MOF at 900 °C, exhibits a more regular flower-like morphology, the largest specific surface area, abundant porosities, and multiple nitrogen functionalities. The remarkable specific capacitances are 138 F g(-1) at 5 mV s(-1) and 149 F g(-1) at 0.5 A g(-1) for the NPC-900 electrode in a 6 M potassium hydroxide aqueous solution. Moreover, the retention of capacitance remains 86.8% (125 F g(-1)) at 1 A g(-1) over 2000 cycles, which displays good chemical stability. These findings suggest that NPC-900 can be applied as a suitable electrode for a supercapacitor.

The antagonistic modulation of Arp2/3 activity by N-WASP, WAVE2 and PICK1 defines dynamic changes in astrocyte morphology

PubMed Central

Murk, Kai; Blanco Suarez, Elena M.; Cockbill, Louisa M. R.; Banks, Paul; Hanley, Jonathan G.

2013-01-01

Summary Astrocytes exhibit a complex, branched morphology, allowing them to functionally interact with numerous blood vessels, neighboring glial processes and neuronal elements, including synapses. They also respond to central nervous system (CNS) injury by a process known as astrogliosis, which involves morphological changes, including cell body hypertrophy and thickening of major processes. Following severe injury, astrocytes exhibit drastically reduced morphological complexity and collectively form a glial scar. The mechanistic details behind these morphological changes are unknown. Here, we investigate the regulation of the actin-nucleating Arp2/3 complex in controlling dynamic changes in astrocyte morphology. In contrast to other cell types, Arp2/3 inhibition drives the rapid expansion of astrocyte cell bodies and major processes. This intervention results in a reduced morphological complexity of astrocytes in both dissociated culture and in brain slices. We show that this expansion requires functional myosin II downstream of ROCK and RhoA. Knockdown of the Arp2/3 subunit Arp3 or the Arp2/3 activator N-WASP by siRNA also results in cell body expansion and reduced morphological complexity, whereas depleting WAVE2 specifically reduces the branching complexity of astrocyte processes. By contrast, knockdown of the Arp2/3 inhibitor PICK1 increases astrocyte branching complexity. Furthermore, astrocyte expansion induced by ischemic conditions is delayed by PICK1 knockdown or N-WASP overexpression. Our findings identify a new morphological outcome for Arp2/3 activation in restricting rather than promoting outwards movement of the plasma membrane in astrocytes. The Arp2/3 regulators PICK1, and N-WASP and WAVE2 function antagonistically to control the complexity of astrocyte branched morphology, and this mechanism underlies the morphological changes seen in astrocytes during their response to pathological insult. PMID:23843614

Habitat partitioning and morphological differentiation: the Southeast Asian Draco lizards and Caribbean Anolis lizards compared.

PubMed

Ord, Terry J; Klomp, Danielle A

2014-06-01

Sympatric species that initially overlap in resource use are expected to partition the environment in ways that will minimize interspecific competition. This shift in resource use can in turn prompt evolutionary changes in morphology. A classic example of habitat partitioning and morphological differentiation are the Caribbean Anolis lizards. Less well studied, but nevertheless striking analogues to the Anolis are the Southeast Asian Draco lizards. Draco and Anolis have evolved independently of each other for at least 80 million years. Their comparison subsequently offers a special opportunity to examine mechanisms of phenotypic differentiation between two ecologically diverse, but phylogenetically distinct groups. We tested whether Draco shared ecological axes of differentiation with Anolis (e.g., habitat use), whether this differentiation reflected interspecific competition, and to what extent adaptive change in morphology has occurred along these ecological axes. Using existing data on Anolis, we compared the habitat use and morphology of Draco in a field study of allopatric and sympatric species on the Malay Peninsula, Borneo and in the Philippines. Sympatric Draco lizards partitioned the environment along common resource axes to the Anolis lizards, especially in perch use. Furthermore, the morphology of Draco was correlated with perch use in the same way as it was in Anolis: species that used wider perches exhibited longer limb lengths. These results provide an important illustration of how interspecific competition can occur along common ecological axes in different animal groups, and how natural selection along these axes can generate the same type of adaptive change in morphology.

Morphological and genetic analysis of four color morphs of bean leaf beetle, Cerotoma trifurcata (Coleoptera: Chrysomelidae)

USDA-ARS?s Scientific Manuscript database

Bean leaf beetle (BLB) exhibits a relatively large amount of morphological variation in terms of color but little is known about the underlying genetic structure and gene flow. Genetic variation among four color phenotypes of the BLB was analyzed using amplified fragment length polymorphisms (AFLP) ...

Ecomorphology of the moray bite: relationship between dietary extremes and morphological diversity.

PubMed

Mehta, Rita S

2009-01-01

The pharyngeal jaws of moray eels function exclusively to transport prey from the oral jaws into the esophagus. This functional innovation in the moray pharyngeal jaw system occurred through the loss of some ancestral functions that presumably included prey processing. Therefore, the oral jaws of morays are used to capture and process prey. Dietary accounts suggest that morays can be categorized as either piscivorous or durophagous in feeding habits. These extreme feeding specializations that select for conflicting biomechanical demands on the oral jaws should result in two discrete clusters of cranial form and diet in morphospace. When functional characters underlying the oral jaws were examined for 10 muraenid species, piscivorous and durophagous morays occupied distinct areas of morphospace. Piscivores exhibited longer jaws, narrower heads, and long recurved teeth, while durophagous morays exhibited shorter jaws, greater dentary depths, and short blunt teeth. Durophagous morays process prey in their oral jaws, and their jaw-opening and jaw-closing ratios, along with their enlarged adductors, revealed jaws modified for force transmission. Pharyngeal jaw characters also separated moray species into different areas of morphospace. For example, Gymnomuraena zebra, a molluscivore, had more teeth on its pharyngobranchials than all other morays, and these teeth were long and thin compared with those of piscivores. The overall patterns of morphological variation corresponded well with moray dietary breadth. In addition, the range of jaw-opening and jaw-closing ratios revealed that for a clade of obligate carnivores, morays exhibit diverse biting behaviors.

Morphology and band structure regulation of graphitic carbon nitride microspheres by solvothermal temperature to boost photocatalytic activity

NASA Astrophysics Data System (ADS)

Wang, Shuaijun; Yan, Qingyun; Dong, Pei; Zhao, Chaocheng; Wang, Yongqiang; Liu, Fang; Li, Lin

2018-06-01

Graphitic carbon nitride (g-C3N4) microspheres (CNMS) were fabricated via a solvothermal method by using supramolecular complexes of dicyandiamide and cyanuric chloride as precursors. The effect of solvothermal temperature on the morphology, band structure, and activity was systematically investigated. Structural characterization results indicate that the samples prepared at 180 °C (CNMS-180) and 200 °C (CNMS-200) possess spherical morphology, while irregular bulk particles were obtained at 160 °C (CN-160). In addition, the band gap increased as the solvothermal temperature decreased from 200 to 160 °C. In comparison with CN-160 and CNMS-200, the valence band of CNMS-180 was more positive and thus gives higher photo-oxidation capability. Accordingly, CNMS-180 exhibits higher photocatalytic degradation efficiency on Rhodamine B, stronger photocurrent response, and lower charge transfer resistance. Additionally, CNMS-180 exhibits excellent stability after four runs. This work might provide a guidance for the regulation of morphology and band structure of g-C3N4-based materials prepared at low temperatures.

Morphology transition of the primary silicon particles in a hypereutectic A390 alloy in high pressure die casting.

PubMed

Wang, J; Guo, Z; Song, J L; Hu, W X; Li, J C; Xiong, S M

2017-11-03

The microstructure of a high-pressure die-cast hypereutectic A390 alloy, including PSPs, pores, α-Al grains and Cu-rich phases, was characterized using synchrotron X-ray tomography, together with SEM, TEM and EBSD. The Cu-rich phases exhibited a net morphology and distributed at the boundaries of the α-Al grains, which in turn surrounded the PSPs. Statistical analysis of the reconstructed 1000 PSPs showed that both equivalent diameter and shape factor of the PSPs exhibited a unimodal distribution with peaks corresponding to 25 μm and 0.78, respectively.) PSPs morphology with multiple twinning were observed and morphological or growth transition of the PSPs from regular octahedral shape (with a shape factor of 0.85 was mainly caused by the constraint of the Cu-rich phases. In particular, the presence of the Cu-rich phases restricted the growth of the α-Al grains, inducing stress on the internal silicon particles, which caused multiple twinning occurrence with higher growth potential and consequently led to growth transitions of the PSPs.

Controllable synthesis of Ln3+ (Ln = Tb, Eu) doped zinc phosphate nano-/micro-structured materials: phase, morphology and luminescence properties.

PubMed

Yue, Dan; Lu, Wei; Li, Chunyang; Zhang, Xinlei; Liu, Chunxia; Wang, Zhenling

2014-02-21

Ln(3+) (Ln = Tb, Eu) doped zinc phosphate tetrahydrate (ZPT:Ln(3+)) and ammonium zinc phosphate (AZP:Ln(3+)) nano-/micro-structured materials were synthesized in aqueous solution without the addition of any structure-directing agent. The phase structures, morphologies and luminescence properties of the as-synthesized samples were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), transmission electron microscopy (TEM), photoluminescence (PL) spectroscopy and lifetime. These investigations indicate that different phosphate sources MnH(3-n)PO4 (M = NH4(+) or Na(+), n = 1, 2, 3) can lead to the altering of morphology from nanosheet to microflower, but have no significant effect on the phase structure of the samples. The microlump, nanosheet, and microflower (constructed by the primary microlumps or nanosheets) of orthorhombic ZPT:Ln(3+) could be selectively prepared by adjusting the pH value from 3.5 to 7.0. A mixture of orthorhombic ZPT:Ln(3+) and monoclinic AZP:Ln(3+) with a microflower morphology was obtained when the pH value was adjusted to 8.0. Monoclinic AZP:Ln(3+) microplate, microcube and nanoparticle morphologies were obtained at pH values of 8.5, 9.0 and 11.0 respectively. The phase transformation and growth mechanism of the diverse morphologies were proposed, and ZPT:Ln(3+) (Ln(3+) = Eu or Tb) samples exhibit red or green emission under the excitation of UV light.

Effects of habitat structure on the epifaunal community in Mussismilia corals: does coral morphology influence the richness and abundance of associated crustacean fauna?

NASA Astrophysics Data System (ADS)

Nogueira, Marcos M.; Neves, Elizabeth; Johnsson, Rodrigo

2015-06-01

Coral habitat structures increase abundance and richness of organisms by providing niches, easy access to resources and refuge from predators. Corals harbor a great variety of animals; the variation in coral species morphology contributes to the heterogeneity and complexity of habitat types. In this report, we studied the richness and abundance of crustaceans (Decapoda, Copepoda, Peracarida and Ostracoda) associated with three species of Mussismilia exhibiting different growth morphologies, in two different coral reefs of the Bahia state (Caramuanas and Boipeba-Moreré, Brazil). Mussismilia hispida is a massive coral; M. braziliensis also has a massive growth pattern, but forms a crevice in the basal area of the corallum; M. harttii has a meandroid pattern. PERMANOVA analysis suggests significant differences in associated fauna richness among Mussismilia species, with higher values for M. harttii, followed by M. braziliensis and later by M. hispida. The same trend was observed for density, except that the comparison of M. braziliensis and M. hispida did not show differences. Redundancy and canonical correspondence analysis indicated that almost all of the crustacean species were more associated with the M. harttii colonies that formed a group clearly separated from colonies of M. braziliensis and M. hispida. We also found that the internal volume of interpolyp space, only present in M. harttii, was the most important factor influencing richness and abundance of all analyzed orders of crustaceans.

Facile chemical approach to ZnO submicrometer particles with controllable morphologies.

PubMed

Bardhan, Rizia; Wang, Hui; Tam, Felicia; Halas, Naomi J

2007-05-22

We have developed a simple wet-chemistry approach to fabricating ZnO submicrometer particles with unique morphologies including rings, bowls, hemispheres, and disks. The size and morphology of the particles can be conveniently tailored by varying the concentrations of the zinc precursor. The reaction temperature, pH, and concentration of ammonia are also found to play critical roles in directing the formation of these particle morphologies. These submicrometer particles exhibit strong white-light emission upon UV excitation as a result of the presence of surface defect states resulting from the fabrication method and synthesis conditions.

Identification of two new phylogenetically distant phytoplasmas from Senna surattensis plants exhibiting stem fasciation and shoot proliferation symptoms

USDA-ARS?s Scientific Manuscript database

Sunshine trees (Senna surattensis Burm.) exhibiting unusual stem fasciation symptoms were observed in Yunnan, China. Morphological abnormalities of the affected plants included enlargement and flattening of stems and excessive proliferation of shoots. An electron microscopic investigation revealed...

Marine Phages As Tracers: Effects of Size, Morphology, and Physico-Chemical Surface Properties on Transport in a Porous Medium.

PubMed

Ghanem, Nawras; Kiesel, Bärbel; Kallies, René; Harms, Hauke; Chatzinotas, Antonis; Wick, Lukas Y

2016-12-06

Although several studies examined the transport of viruses in terrestrial systems only few studies exist on the use of marine phages (i.e., nonterrestrial viruses infecting marine host bacteria) as sensitively detectable microbial tracers for subsurface colloid transport and water flow. Here, we systematically quantified and compared for the first time the effects of size, morphology and physicochemical surface properties of six marine phages and two coliphages (MS2, T4) on transport in sand-filled percolated columns. Phage-sand interactions were described by colloidal filtration theory and the extended Derjaguin-Landau-Verwey-Overbeek approach (XDLVO), respectively. The phages belonged to different families and comprised four phages never used in transport studies (i.e., PSA-HM1, PSA-HP1, PSA-HS2, and H3/49). Phage transport was influenced by size, morphology and hydrophobicity in an approximate order of size > hydrophobicity ≥ morphology. Two phages PSA-HP1, PSA-HS2 (Podoviridae and Siphoviridae) exhibited similar mass recovery as commonly used coliphage MS2 and were 7-fold better transported than known marine phage vB_PSPS-H40/1. Differing properties of the marine phages may be used to trace transport of indigenous viruses, natural colloids or anthropogenic nanomaterials and, hence, contribute to better risk analysis. Our results underpin the potential role of marine phages as microbial tracer for transport of colloidal particles and water flow.

Developmental ethanol exposure alters the morphology of mouse prefrontal neurons in a layer-specific manner.

PubMed

Louth, Emma L; Luctkar, Hanna D; Heney, Kayla A; Bailey, Craig D C

2018-01-01

Chronic developmental exposure to ethanol can lead to a wide variety of teratogenic effects, which in humans are known as fetal alcohol spectrum disorders (FASD). Individuals affected by FASD may exhibit persistent impairments to cognitive functions such as learning, memory, and attention, which are highly dependent on medial prefrontal cortex (mPFC) circuitry. The objective of this study was to determine long-term effects of chronic developmental ethanol exposure on mPFC neuron morphology, in order to better-understand potential neuronal mechanisms underlying cognitive impairments associated with FASD. C57BL/6-strain mice were exposed to ethanol or an isocaloric/isovolumetric amount of sucrose (control) via oral gavage, administered both to the dam from gestational day 10-18 and directly to pups from postnatal day 4-14. Brains from male mice were collected at postnatal day 90 and neurons were stained using a modified Golgi-Cox method. Pyramidal neurons within layers II/III, V and VI of the mPFC were imaged, traced in three dimensions, and assessed using Sholl and branch structure analyses. Developmental ethanol exposure differentially impacted adult pyramidal neuron morphology depending on mPFC cortical layer. Neurons in layer II/III exhibited increased size and diameter of dendrite trees, whereas neurons in layer V were not affected. Layer VI neurons with long apical dendrites had trees with decreased diameter that extended farther from the soma, and layer VI neurons with short apical dendrite trees exhibited decreased tree size overall. These layer-specific alterations to mPFC neuron morphology may form a novel morphological mechanism underlying long-term mPFC dysfunction and resulting cognitive impairments in FASD. Copyright © 2017 Elsevier B.V. All rights reserved.

Ultrasound synthesis of Y2O3: Dy3+ nanophosphor: Structural and photometric properties suitable for wLEDs

NASA Astrophysics Data System (ADS)

Marappa, B.; Rudresha, M. S.; Nagabhsuhana, H.; Basavaraj, R. B.; Prasad, B. Daruka

2017-05-01

The facile ultrasound synthesis of Y2O3:Dy3+ nanostructures by using bio-surfactant mimosa pudica leaves extract. The concentration of bio-surfactant was the key factor in controlling the morphology of Y2O3 nanostructures. The formation of different morphologies of Y2O3: Dy3+ was characterized by SEM, TEM and HRTEM. The PXRD data and Rietveld analysis evident the formation of single phase Y2O3 with cubic crystal structure. The influence of Dy3+ concentration on the structure morphology, UV absorption, and PL emission of Y2O3: Dy3+ nanostructures were investigated systematically. Y2O3: Dy3+ exhibits intense warm white emission with CIE chromaticity coordinates (0.32, 0.33) and CCT value is 5525 K which corresponds to vertical day light. SEM micrographs showed superstructure morphology influenced by both sonication time as well as surfactant concentration. Pl emission spectra shows three intense peaks observed at 480, 574 and 666 nm attributed to the Dy3+ transitions. The photometric properties were studied by evaluating the CIE, CCT diagrams and the results were very fruitful in making the white light emitting diodes. This method has been considered to be the cost effective and eco-friendly to synthesize nanomaterials with superior morphology suitable for display device applications.

Association of monoamine oxidase-A genetic variants and amygdala morphology in violent offenders with antisocial personality disorder and high psychopathic traits.

PubMed

Kolla, Nathan J; Patel, Raihaan; Meyer, Jeffrey H; Chakravarty, M Mallar

2017-08-29

Violent offending is elevated among individuals with antisocial personality disorder (ASPD) and high psychopathic traits (PP). Morphological abnormalities of the amygdala and orbitofrontal cortex (OFC) are present in violent offenders, which may relate to the violence enacted by ASPD + PP. Among healthy males, monoamine oxidase-A (MAO-A) genetic variants linked to low in vitro transcription (MAOA-L) are associated with structural abnormalities of the amygdala and OFC. However, it is currently unknown whether amygdala and OFC morphology in ASPD relate to MAO-A genetic polymorphisms. We studied 18 ASPD males with a history of violent offending and 20 healthy male controls. Genomic DNA was extracted from peripheral leukocytes to determine MAO-A genetic polymorphisms. Subjects underwent a T1-weighted MRI anatomical brain scan that provided vertex-wise measures of amygdala shape and surface area and OFC cortical thickness. We found that ASPD + PP subjects with MAOA-L exhibited decreased surface area in the right basolateral amygdala nucleus and increased surface area in the right anterior cortical amygdaloid nucleus versus healthy MAOA-L carriers. This study is the first to describe genotype-related morphological differences of the amygdala in a population marked by high aggression. Deficits in emotional regulation that contribute to the violence of ASPD + PP may relate to morphological changes of the amygdala under genetic control.

Polyethersulfone - barium chloride blend ultrafiltration membranes for dye removal studies

NASA Astrophysics Data System (ADS)

Rambabu, K.; Srivatsan, N.; Gurumoorthy, Anand V. P.

2017-11-01

A series of Polyethersulfone (PES) - barium chloride (BaCl2) blend ultra filtration membrane was developed by varying the BaCl2 concentration in the dope solution. Prepared membranes were subjected to membrane characterization and their performance was studied through dye rejection tests. Morphological studies through SEM and AFM showed that the composite membranes exhibited differences in morphologies, porosities and properties due to the BaCl2 addition as compared with pristine PES membrane. Addition of the inorganic modifier enhanced the hydrophilicity and water permeability of the blend membrane system. Polymer enhanced ultrafiltration of dye solutions showed that the proposed blend system had better performance in terms of flux and rejection efficiency than the pure polymer membrane. The performance of the 2 wt% BaCl2 blend membrane was more promising for application to real time dye wastewater studies.

Improving the corrosion properties of magnesium AZ31 alloy GTA weld metal using microarc oxidation process

NASA Astrophysics Data System (ADS)

Siva Prasad, M.; Ashfaq, M.; Kishore Babu, N.; Sreekanth, A.; Sivaprasad, K.; Muthupandi, V.

2017-05-01

In this work, the morphology, phase composition, and corrosion properties of microarc oxidized (MAO) gas tungsten arc (GTA) weldments of AZ31 alloy were investigated. Autogenous gas tungsten arc welds were made as full penetration bead-on-plate welding under the alternating-current mode. A uniform oxide layer was developed on the surface of the specimens with MAO treatment in silicate-based alkaline electrolytes for different oxidation times. The corrosion behavior of the samples was evaluated by potentiodynamic polarization and electrochemical impedance spectroscopy. The oxide film improved the corrosion resistance substantially compared to the uncoated specimens. The sample coated for 10 min exhibited better corrosion properties. The corrosion resistance of the coatings was concluded to strongly depend on the morphology, whereas the phase composition and thickness were concluded to only slightly affect the corrosion resistance.

Modified Stranski-Krastanov growth in Ge/Si heterostructures via nanostenciled pulsed laser deposition.

PubMed

MacLeod, J M; Cojocaru, C V; Ratto, F; Harnagea, C; Bernardi, A; Alonso, M I; Rosei, F

2012-02-17

The combination of nanostenciling with pulsed laser deposition (PLD) provides a flexible, fast approach for patterning the growth of Ge on Si. Within each stencilled site, the morphological evolution of the Ge structures with deposition follows a modified Stranski-Krastanov (SK) growth mode. By systematically varying the PLD parameters (laser repetition rate and number of pulses) on two different substrate orientations (111 and 100), we have observed corresponding changes in growth morphology, strain and elemental composition using scanning electron microscopy, atomic force microscopy and μ-Raman spectroscopy. The growth behaviour is well predicted within a classical SK scheme, although the Si(100) growth exhibits significant relaxation and ripening with increasing coverage. Other novel aspects of the growth include the increased thickness of the wetting layer and the kinetic control of Si/Ge intermixing via the PLD repetition rate.

Investigation of the asymmetric misfit dislocation morphology in epitaxial layers with the zinc-blende structure

NASA Technical Reports Server (NTRS)

Fox, Bradley A.; Jesser, William A.

1990-01-01

The source of the asymmetry in the dislocation morphology exhibited in the epitaxial growth of compound semiconductors on (100) was investigated. A thickness wedge of p- and n-type GaAs(0.95)P(0.05) was grown on GaAs by metalorganic chemical vapor deposition, and the effect of misorientation on the resolved shear stress for each slip system was calculated and eliminated as the source of the asymmetry. Another potential source of asymmetry, the thickness gradient, was also eliminated. Results show that the substrate misorientation and the thickness gradient do not significantly contribute to the asymmetry and that the dominant contributor to the asymmetry of misfit dislocations in the (001) epitaxial interface can be attributed to the differences in the Peierls barriers between the two types of dilocations in GaAsP/GaAs.

Charge Generation Dynamics in Efficient All-Polymer Solar Cells: Influence of Polymer Packing and Morphology.

PubMed

Gautam, Bhoj R; Lee, Changyeon; Younts, Robert; Lee, Wonho; Danilov, Evgeny; Kim, Bumjoon J; Gundogdu, Kenan

2015-12-23

All-polymer solar cells exhibit rapid progress in power conversion efficiency (PCE) from 2 to 7.7% over the past few years. While this improvement is primarily attributed to efficient charge transport and balanced mobility between the carriers, not much is known about the charge generation dynamics in these systems. Here we measured exciton relaxation and charge separation dynamics using ultrafast spectroscopy in polymer/polymer blends with different molecular packing and morphology. These measurements indicate that preferential face-on configuration with intermixed nanomorphology increases the charge generation efficiency. In fact, there is a direct quantitative correlation between the free charge population in the ultrafast time scales and the external quantum efficiency, suggesting not only the transport but also charge generation is key for the design of high performance all polymer solar cells.

Liquid-phase characterization of molecular interactions in polyunsaturated and n-fatty acid methyl esters by (1)H low-field nuclear magnetic resonance.

PubMed

Meiri, Nitzan; Berman, Paula; Colnago, Luiz Alberto; Moraes, Tiago Bueno; Linder, Charles; Wiesman, Zeev

2015-01-01

To identify and develop the best renewable and low carbon footprint biodiesel substitutes for petroleum diesel, the properties of different biodiesel candidates should be studied and characterized with respect to molecular structures versus biodiesel liquid property relationships. In our previous paper, (1)H low-field nuclear magnetic resonance (LF-NMR) relaxometry was investigated as a tool for studying the liquid-phase molecular packing interactions and morphology of fatty acid methyl esters (FAMEs). The technological potential was demonstrated with oleic acid and methyl oleate standards having similar alkyl chains but different head groups. In the present work, molecular organization versus segmental and translational movements of FAMEs in their pure liquid phase, with different alkyl chain lengths (10-20 carbons) and degrees of unsaturation (0-3 double bonds), were studied with (1)H LF-NMR relaxometry and X-ray, (1)H LF-NMR diffusiometry, and (13)C high-field NMR. Based on density values and X-ray measurements, it was proposed that FAMEs possess a liquid crystal-like order above their melting point, consisting of random liquid crystal aggregates with void spaces between them, whose morphological properties depend on chain length and degree of unsaturation. FAMEs were also found to exhibit different degrees of rotational and translational motions, which were rationalized by chain organization within the clusters, and the degree and type of molecular interactions and temperature effects. At equivalent fixed temperature differences from melting point, saturated FAME molecules were found to have similar translational motion regardless of chain length, expressed by viscosity, self-diffusion coefficients, and spin-spin (T 2) (1)H LF-NMR. T 2 distributions suggest increased alkyl chain rigidity, and reduced temperature response of the peaks' relative contribution with increasing unsaturation is a direct result of the alkyl chain's morphological packing and molecular interactions. Both the peaks' assignments for T 2 distributions of FAMEs and the model for their liquid crystal-like morphology in the liquid phase were confirmed. The study of morphological structures within liquids and their response to temperature changes by (1)H LF-NMR has a high value in the field of biodiesel and other research and applied disciplines in numerous physicochemical- and organizational-based properties, processes, and mechanisms of alkyl chains, molecular interactions, and morphologies.

Effects of two sediment types on the fluorescence yield of two Hawaiian scleractinian corals

USGS Publications Warehouse

Piniak, G.A.

2007-01-01

This study used non-invasive pulse-amplitude modulated (PAM) fluorometry to measure the maximum fluorescence yield (Fv/Fm) of two Hawaiian scleractinian coral species exposed to short-term sedimentation stress. Beach sand or harbor mud was applied to coral fragments in a flow-through aquarium system for 0-45 h, and changes in Fv/Fm were measured as a function of sediment type and length of exposure. Corals were monitored for up to 90 h to document recovery after sediment removal. Sediment deposition significantly decreased Fv/Fm in both species and was a function of sediment type and time. Corals that received sediment for 30 h or more had the greatest reduction in yield and exhibited little recovery over the course of the experiment. Harbor mud caused a greater reduction in Porites lobata yield than beach sand, whereas both sediment types had equally deleterious effects on Montipora capitata. Colony morphology and sediment type were important factors in determining yield reduction-P. lobata minimized damage from coarse sand grains by passive sediment rejection or accumulation in depressions in the skeleton, and fluorescence yield decreased most in corals exposed to sticky harbor mud or in colonies with flattened morphologies. Species-specific differences could not be tested due to differences in colony morphology and surface area. ?? 2007.

Morphological and immunohistochemical diversity of endometrial stromal sarcoma in rats.

PubMed

Kumabe, Shino; Sato, Junko; Tomonari, Yuki; Takahashi, Miwa; Inoue, Kaoru; Yoshida, Midori; Doi, Takuya; Wako, Yumi; Tsuchitani, Minoru

2018-04-01

To clarify the histopathological characteristics of rat endometrial stromal sarcoma (ESS), we morphologically reviewed 12 malignant uterine tumors protruding into the lumen in previous rat carcinogenicity studies. The 12 cases were classified into the following 6 types based on their morphological features: spindle cell and collagen rich type, pleomorphic/spindle cell and compact type, decidual alteration type, histiocytic and multinucleated giant cell mixture type, Antoni A-type schwannoma type, and Antoni B-type schwannoma type. Immunohistochemically, tumor cells in all cases exhibited focal or diffuse positive reactions for vimentin, and 11 of the 12 cases were positive for S-100. Interestingly, 9 cases were positive for desmin or αSMA, indicating tumor cells expressing smooth muscle properties. Both Antoni A- and B-type schwannoma types showed low reactions for both muscle markers. Positive results for estrogen receptor α in the 11 cases suggested that they were derived from endometrial stromal cells. On the basis of their immunohistochemical profiles, they were considered to be derived from endometrial stromal cells while they showed morphological variation. The detection of a basement membrane surrounding tumor cells might not be a definitive indicator for differential diagnosis of ESS from malignant schwannoma. In conclusion, ESS could exhibit wide morphological and immunohistochemical variation including features of schwannoma or smooth muscle tumor.

Differences in mechanical and structural properties of surface and aerial petioles of the aquatic plant Nymphaea odorata subsp. tuberosa (Nymphaeaceae).

PubMed

Etnier, Shelley A; Villani, Philip J

2007-07-01

Lily pads (Nymphaea odorata) exhibit heterophylly where a single plant may have leaves that are submerged, floating, or above (aerial) the surface of the water. Lily pads are placed in a unique situation because each leaf form is exposed to a distinctly different set of mechanical demands. While surface petioles may be loaded in tension under conditions of wind or waves, aerial petioles are loaded in compression because they must support the weight of the lamina. Using standard techniques, we compared the mechanical and morphological properties of both surface and aerial leaf petioles. Structural stiffness (EI) and the second moment of area (I) were higher in aerial petioles, although we detected no differences in other mechanical values (elastic modulus [E], extension ratio, and breaking strength). Morphologically, aerial petioles had a thicker rind, with increased collenchyma tissue and sclereid cell frequency. Aerial petioles also had a larger cross-sectional area and were more elliptical. Thus, subtle changes in the distribution of materials, rather than differences in their makeup, differentiate petiole forms. We suggest that the growth of aerial petioles may be an adaptive response to shading, allowing aerial leaves to rise above a crowded water surface.

Sex-specific evolution during the diversification of live-bearing fishes.

PubMed

Culumber, Zachary W; Tobler, Michael

2017-08-01

Natural selection is often assumed to drive parallel functional diversification of the sexes. But males and females exhibit fundamental differences in their biology, and it remains largely unknown how sex differences affect macroevolutionary patterns. On microevolutionary scales, we understand how natural and sexual selection interact to give rise to sex-specific evolution during phenotypic diversification and speciation. Here we show that ignoring sex-specific patterns of functional trait evolution misrepresents the macroevolutionary adaptive landscape and evolutionary rates for 112 species of live-bearing fishes (Poeciliidae). Males and females of the same species evolve in different adaptive landscapes. Major axes of female morphology were correlated with environmental variables but not reproductive investment, while male morphological variation was primarily associated with sexual selection. Despite the importance of both natural and sexual selection in shaping sex-specific phenotypic diversification, species diversification was overwhelmingly associated with ecological divergence. Hence, the inter-predictability of mechanisms of phenotypic and species diversification may be limited in many systems. These results underscore the importance of explicitly addressing sex-specific diversification in empirical and theoretical frameworks of evolutionary radiations to elucidate the roles of different sources of selection and constraint.

Geometric morphometric analysis of allometric variation in the mandibular morphology of the hominids of Atapuerca, Sima de los Huesos site.

PubMed

Rosas, Antonio; Bastir, Markus

2004-06-01

Allometry is an important factor of morphological integration that contributes to the organization of the phenotype and its variation. Variation in the allometric shape of the mandible is particularly important in hominid evolution because the mandible carries important taxonomic traits. Some of these traits are known to covary with size, particularly the retromolar space, symphyseal curvature, and position of the mental foramen. The mandible is a well studied system in the context of the evolutionary development of complex morphological structures because it is composed of different developmental units that are integrated within a single bone. In the present study, we investigated the allometric variation of two important developmental units that are separated by the inferior nerve (a branch of CN V3). We tested the null hypothesis that there would be no difference in allometric variation between the two components. Procrustes-based geometric morphometrics of 20 two-dimensional (2D) landmarks were analyzed by multivariate regressions of shape on size in samples from 121 humans, 48 chimpanzees, and 50 gorillas (all recent specimens), eight fossil hominids from Atapuerca, Sima de los Huesos (AT-SH), and 17 Neandertals. The findings show that in all of the examined species, there was significantly greater allometric variation in the supra-nerve unit than in the infra-nerve unit. The formation of the retromolar space exhibited an allometric relationship with the supra-nerve unit in all of the species studied. The formation of the chin-like morphology is an "apodynamic" feature of the infra-nerve unit in the AT-SH hominids. The results of this study support the hypothesis that allometry contributes to the organization of variation in complex morphological structures. Copyright 2004 Wiley-Liss, Inc.

Hippocampal Astrocytes in Migrating and Wintering Semipalmated Sandpiper Calidris pusilla.

PubMed

Carvalho-Paulo, Dario; de Morais Magalhães, Nara G; de Almeida Miranda, Diego; Diniz, Daniel G; Henrique, Ediely P; Moraes, Isis A M; Pereira, Patrick D C; de Melo, Mauro A D; de Lima, Camila M; de Oliveira, Marcus A; Guerreiro-Diniz, Cristovam; Sherry, David F; Diniz, Cristovam W P

2017-01-01

Seasonal migratory birds return to the same breeding and wintering grounds year after year, and migratory long-distance shorebirds are good examples of this. These tasks require learning and long-term spatial memory abilities that are integrated into a navigational system for repeatedly locating breeding, wintering, and stopover sites. Previous investigations focused on the neurobiological basis of hippocampal plasticity and numerical estimates of hippocampal neurogenesis in birds but only a few studies investigated potential contributions of glial cells to hippocampal-dependent tasks related to migration. Here we hypothesized that the astrocytes of migrating and wintering birds may exhibit significant morphological and numerical differences connected to the long-distance flight. We used as a model the semipalmated sandpiper Calidris pusilla , that migrates from northern Canada and Alaska to South America. Before the transatlantic non-stop long-distance component of their flight, the birds make a stopover at the Bay of Fundy in Canada. To test our hypothesis, we estimated total numbers and compared the three-dimensional (3-D) morphological features of adult C. pusilla astrocytes captured in the Bay of Fundy ( n = 249 cells) with those from birds captured in the coastal region of Bragança, Brazil, during the wintering period ( n = 250 cells). Optical fractionator was used to estimate the number of astrocytes and for 3-D reconstructions we used hierarchical cluster analysis. Both morphological phenotypes showed reduced morphological complexity after the long-distance non-stop flight, but the reduction in complexity was much greater in Type I than in Type II astrocytes. Coherently, we also found a significant reduction in the total number of astrocytes after the transatlantic flight. Taken together these findings suggest that the long-distance non-stop flight altered significantly the astrocytes population and that morphologically distinct astrocytes may play different physiological roles during migration.

Prevalence and morphology of druse types in the macula and periphery of eyes with age-related maculopathy.

PubMed

Rudolf, Martin; Clark, Mark E; Chimento, Melissa F; Li, Chuan-Ming; Medeiros, Nancy E; Curcio, Christine A

2008-03-01

Macular drusen are hallmarks of age-related maculopathy (ARM), but these focal extracellular lesions also appear with age in the peripheral retina. The present study was conducted to determine regional differences in morphology that contribute to the higher vulnerability of the macula to advanced disease. Drusen from the macula (n = 133) and periphery (n = 282) were isolated and concentrated from nine ARM-affected eyes. A semiquantitative light microscopic evaluation of 1-mum-thick sections included 12 parameters. Significant differences were found between the macula and periphery in ease of isolation, distribution of druse type, composition qualities, and substructures. On harvesting, macular drusen were friable, with liquefied or crystallized contents. Peripheral drusen were resilient and never crystallized. On examination, soft drusen appeared in the macula only, had homogeneous content without significant substructures, and had abundant basal laminar deposits (BlamD). Several substructures, previously postulated as signatures of druse biogenesis, were found primarily in hard drusen. Specific to hard drusen, which appeared everywhere, were central subregions and reduced RPE coverage. Macular hard drusen with a rich substructure profile differed from primarily homogeneous peripheral hard drusen. Compound drusen, found in the periphery only, exhibited a composition profile that was not intermediate between hard and soft. The data confirm regional differences in druse morphology, composition, and physical properties, most likely based on different formative mechanisms that may contribute to macular susceptibility for ARM progression. Two other reasons that only the macula is at high risk despite having relatively few drusen are the exclusive presence of soft drusen and the abundant BlamD in this region.

Characterization of CeO{sub 2} crystals synthesized with different amino acids

DOE Office of Scientific and Technical Information (OSTI.GOV)

Atla, Shashi B.; Wu, Min-Nan; Pan, Wei

We investigated the relationship between the structures of the CeO{sub 2} products (particle size, morphology and their characteristics) prepared using different amino acids. Cerium hydroxide carbonate precursors were initially prepared by a hydrothermal method and were subsequently converted to CeO{sub 2} by its thermal decomposition. Various amino acids were used as structure-directing agents in the presence of cerium nitrate and urea as precursors. The results indicate morphology selectivity using different amino acids; CeO{sub 2} structures, such as quasi-prism-sphere, straw-bundle, urchin-flower like and polyhedron prisms, indeed could be produced. Raman and photoluminescence studies indicate the presence of oxygen vacancies in themore » CeO{sub 2} samples. Photoluminescence spectra of CeO{sub 2} with L-Valine exhibit stronger emission compared with other amino acids utilized under this study, indicating the higher degree of defects in these particles. This study clearly indicates that the degree of defects varied in the presence of different amino acids. Improved precision to control the crystal morphology is important in various material applications and our study provides a novel method to achieve this specificity. - Highlights: • We used urea hydrolysis of process for synthesis of CeO{sub 2}. • Structures have been directed using various amino acids. • We obtained straw bundle-like, quasi prism-sphere, polyhedron prisms and urchin flower-like based on amino acids. • We have found that amino acids could achieve the specificity of different degrees of defects. • This could provide the “tailor-make” of cerium crystals.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ricciardelli, Elena; Tamone, Amelie; Cava, Antonio

We explore the morphology of galaxies living in the proximity of cosmic voids, using a sample of voids identified in the Sloan Digital Sky Survey Data Release 7. At all stellar masses, void galaxies exhibit morphologies of a later type than galaxies in a control sample, which represent galaxies in an average density environment. We interpret this trend as a pure environmental effect, independent of the mass bias, due to a slower galaxy build-up in the rarefied regions of voids. We confirm previous findings about a clear segregation in galaxy morphology, with galaxies of a later type being found atmore » smaller void-centric distances with respect to the early-type galaxies. We also show, for the first time, that the radius of the void has an impact on the evolutionary history of the galaxies that live within it or in its surroundings. In fact, an enhanced fraction of late-type galaxies is found in the proximity of voids larger than the median void radius. Likewise, an excess of early-type galaxies is observed within or around voids of a smaller size. A significant difference in galaxy properties in voids of different sizes is observed up to 2 R {sub void}, which we define as the region of influence of voids. The significance of this difference is greater than 3 σ for all the volume-complete samples considered here. The fraction of star-forming galaxies shows the same behavior as the late-type galaxies, but no significant difference in stellar mass is observed in the proximity of voids of different sizes.« less

Field emission properties and strong localization effect in conduction mechanism of nanostructured perovskite LaNiO{sub 3}

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kamble, Ramesh B., E-mail: rbk.physics@coep.ac.in; Department of Physics, College of Engineering, Pune 411005, Maharashtra; Tanty, Narendra

2016-08-22

We report the potential field emission of highly conducting metallic perovskite lanthanum nickelate (LaNiO{sub 3}) from the nanostructured pyramidal and whisker shaped tips as electron emitters. Nano particles of lanthanum nickelate (LNO) were prepared by sol-gel route. Structural and morphological studies have been carried out. Field emission of LNO exhibited high emission current density, J = 3.37 mA/cm{sup 2} at a low threshold electric field, E{sub th} = 16.91 V/μm, obeying Fowler–Nordheim tunneling. The DC electrical resistivity exhibited upturn at 11.6 K indicating localization of electron at low temperature. Magnetoresistance measurement at different temperatures confirmed strong localization in nanostructured LNO obeying Anderson localization effect at low temperature.

Ice Shaping Properties, Similar to That of Antifreeze Proteins, of a Zirconium Acetate Complex

PubMed Central

Deville, Sylvain; Viazzi, Céline; Leloup, Jérôme; Lasalle, Audrey; Guizard, Christian; Maire, Eric; Adrien, Jérôme; Gremillard, Laurent

2011-01-01

The control of the growth morphologies of ice crystals is a critical issue in fields as diverse as biomineralization, medicine, biology, civil or food engineering. Such control can be achieved through the ice-shaping properties of specific compounds. The development of synthetic ice-shaping compounds is inspired by the natural occurrence of such properties exhibited by antifreeze proteins. We reveal how a particular zirconium acetate complex is exhibiting ice-shaping properties very similar to that of antifreeze proteins, albeit being a radically different compound. We use these properties as a bioinspired approach to template unique faceted pores in cellular materials. These results suggest that ice-structuring properties are not exclusive to long organic molecules and should broaden the field of investigations and applications of such substances. PMID:22028886

Surface-enhanced Raman scattering from silver nanostructures with different morphologies

NASA Astrophysics Data System (ADS)

Zhang, W. C.; Wu, X. L.; Kan, C. X.; Pan, F. M.; Chen, H. T.; Zhu, J.; Chu, Paul K.

2010-07-01

Scanning electron microscopy and X-ray diffraction reveal that four different types of crystalline silver nanostructures including nanoparticles, nanowires, nanocubes, and bipyramids are synthesized by a solvothermal method by reducing silver nitrate with ethylene glycol using poly(vinylpyrrolidone) as an adsorption agent and adding different quantities of sodium chloride to the solution. These nanostructures which exhibit different surface plasma resonance properties in the ultraviolet-visible region are shown to be good surface-enhanced Raman scattering (SERS) substrates using rhodamine 6G molecules. Our results demonstrate that the silver nanocubes, bipyramids with sharp corners and edges, and aggregated silver nanoparticles possess better SERS properties than the silver nanowires, indicating that they can serve as high-sensitivity substrates in SERS-based measurements.

Evaluation of morpho-anatomical and chemical differences between varieties of the medicinal plant Casearia sylvestris Swartz.

PubMed

Claudino, Josiane C; Sacramento, Luis V S do; Koch, Ingrid; Santos, Helen A; Cavalheiro, Alberto J; Tininis, Aristeu G; Santos, André G dos

2013-01-01

Casearia sylvestris Swartz (Salicaceae) has been used in traditional medicine and its leaf extracts have been exhibited important pharmacological activities. The species presents morphological, chemical and genetic variation. Two varieties are considered due external morphological differences: C. sylvestris var. sylvestris and var. lingua. There are difficulties in definition of these varieties. The objective of this work is to evaluate chemical and morpho-anatomical differences between C. sylvestris varieties that can be applied in their distinction for pharmaceutical or botanical purposes. Transverse and paradermic sections of leaves were prepared for morpho-anatomical, histochemical and quantitative microscopy (stomatal and palisade index) analyses. Diterpene profiles of the specimens were obtained by HPLC-DAD and TLC. Morpho-anatomical analyses demonstrated significant differences between the varieties only in paradermic sections: var. sylvestris--polygonal epidermic cell walls and hypostomatic; var. lingua--rounded epidermic cell walls and amphistomatic. No differences were observed for stomatal index; palisade index was found 2.8 for var. lingua and 3.9 for var. sylvestris. Chromatographic analyses confirmed previous results demonstrating that diterpene profile in varieties differs, with predominance of these metabolites in var. sylvestris. In conclusion, this work indicates that chromatographic analysis besides morpho-anatomical analysis can be applied in distinction of C. sylvestris varieties.

Arsia Mons by Day and Night

NASA Image and Video Library

2004-06-22

Released 22 June 2004 This pair of images shows part of Arsia Mons. Day/Night Infrared Pairs The image pairs presented focus on a single surface feature as seen in both the daytime and nighttime by the infrared THEMIS camera. The nighttime image (right) has been rotated 180 degrees to place north at the top. Infrared image interpretation Daytime: Infrared images taken during the daytime exhibit both the morphological and thermophysical properties of the surface of Mars. Morphologic details are visible due to the effect of sun-facing slopes receiving more energy than antisun-facing slopes. This creates a warm (bright) slope and cool (dark) slope appearance that mimics the light and shadows of a visible wavelength image. Thermophysical properties are seen in that dust heats up more quickly than rocks. Thus dusty areas are bright and rocky areas are dark. Nighttime: Infrared images taken during the nighttime exhibit only the thermophysical properties of the surface of Mars. The effect of sun-facing versus non-sun-facing energy dissipates quickly at night. Thermophysical effects dominate as different surfaces cool at different rates through the nighttime hours. Rocks cool slowly, and are therefore relatively bright at night (remember that rocks are dark during the day). Dust and other fine grained materials cool very quickly and are dark in nighttime infrared images. Image information: IR instrument. Latitude -19.6, Longitude 241.9 East (118.1 West). 100 meter/pixel resolution. http://photojournal.jpl.nasa.gov/catalog/PIA06399

Crater Ejecta by Day and Night

NASA Image and Video Library

2004-06-24

Released 24 June 2004 This pair of images shows a crater and its ejecta. Day/Night Infrared Pairs The image pairs presented focus on a single surface feature as seen in both the daytime and nighttime by the infrared THEMIS camera. The nighttime image (right) has been rotated 180 degrees to place north at the top. Infrared image interpretation Daytime: Infrared images taken during the daytime exhibit both the morphological and thermophysical properties of the surface of Mars. Morphologic details are visible due to the effect of sun-facing slopes receiving more energy than antisun-facing slopes. This creates a warm (bright) slope and cool (dark) slope appearance that mimics the light and shadows of a visible wavelength image. Thermophysical properties are seen in that dust heats up more quickly than rocks. Thus dusty areas are bright and rocky areas are dark. Nighttime: Infrared images taken during the nighttime exhibit only the thermophysical properties of the surface of Mars. The effect of sun-facing versus non-sun-facing energy dissipates quickly at night. Thermophysical effects dominate as different surfaces cool at different rates through the nighttime hours. Rocks cool slowly, and are therefore relatively bright at night (remember that rocks are dark during the day). Dust and other fine grained materials cool very quickly and are dark in nighttime infrared images. Image information: IR instrument. Latitude -9, Longitude 164.2 East (195.8 West). 100 meter/pixel resolution. http://photojournal.jpl.nasa.gov/catalog/PIA06445

Salicylic Acid Alleviates the Adverse Effects of Salt Stress on Dianthus superbus (Caryophyllaceae) by Activating Photosynthesis, Protecting Morphological Structure, and Enhancing the Antioxidant System

PubMed Central

Ma, Xiaohua; Zheng, Jian; Zhang, Xule; Hu, Qingdi; Qian, Renjuan

2017-01-01

Salt stress critically affects the physiological processes and morphological structure of plants, resulting in reduced plant growth. Salicylic acid (SA) is an important signal molecule that mitigates the adverse effects of salt stress on plants. Large pink Dianthus superbus L. (Caryophyllaceae) usually exhibit salt-tolerant traits under natural conditions. To further clarify the salt-tolerance level of D. superbus and the regulating mechanism of exogenous SA on the growth of D. superbus under different salt stresses, we conducted a pot experiment to examine the biomass, photosynthetic parameters, stomatal structure, chloroplast ultrastructure, reactive oxygen species (ROS) concentrations, and antioxidant activities of D. superbus young shoots under 0.3, 0.6, and 0.9% NaCl conditions, with and without 0.5 mM SA. D. superbus exhibited reduced growth rate, decreased net photosynthetic rate (Pn), increased relative electric conductivity (REC) and malondialdehyde (MDA) contents, and poorly developed stomata and chloroplasts under 0.6 and 0.9% salt stress. However, exogenously SA effectively improved the growth, photosynthesis, antioxidant enzyme activity, and stoma and chloroplast development of D. superbus. However, when the plants were grown under severe salt stress (0.9% NaCl condition), there was no significant difference in the plant growth and physiological responses between SA-treated and non-SA-treated plants. Therefore, our research suggests that exogenous SA can effectively counteract the adverse effect of moderate salt stress on D. superbus growth and development. PMID:28484476

Sexually dimorphic tridimensionally preserved pterosaurs and their eggs from China.

PubMed

Wang, Xiaolin; Kellner, Alexander W A; Jiang, Shunxing; Wang, Qiang; Ma, Yingxia; Paidoula, Yahefujiang; Cheng, Xin; Rodrigues, Taissa; Meng, Xi; Zhang, Jialiang; Li, Ning; Zhou, Zhonghe

2014-06-16

The pterosaur record is generally poor, with little information about their populations, and pterosaur eggs are even rarer, with only four isolated and flattened eggs found to date. We report here a population of a new sexually dimorphic pterosaur species (Hamipterus tianshanensis gen. et sp. nov.), with five exceptionally well-preserved three-dimensional eggs, from the Early Cretaceous deposit in northwestern China. About 40 male and female individuals in total were recovered, but the actual number associated might be in the hundreds. All of the discovered skulls have crests, which exhibit two different morphologies in size, shape, and robustness. The eggs show pliable depressions with cracking and crazing on the outer surface. The eggshell, observed by scanning electron microscopy and energy-dispersive spectroscopy, comprises a thin calcareous external hard shell followed by a soft membrane. These fossils shed new light on the reproductive strategy, ontogeny, and behavior of pterosaurs. The cranial crests show sexually dimorphic morphologies, with presumed males and females differing in crest size, shape, and robustness. Ontogenetic variation is reflected mainly in the expansion of the rostrum. The eggs have some external rigidity of the general pliable eggshell, and the microstructure of the eggshell is similar to that of some modern "soft" snake eggs. We suggest that this new pterosaur nested in colonies and thus exhibited gregarious behavior, a possible general trend for at least derived pterodactyloid pterosaurs. Copyright © 2014 Elsevier Ltd. All rights reserved.

The utility of captive animals in actualistic research: A geometric morphometric exploration of the tooth row of Alligator mississippiensis suggesting ecophenotypic influences and functional constraints.

PubMed

Drumheller, Stephanie K; Wilberg, Eric W; Sadleir, Rudyard W

2016-07-01

Captive broad snouted crocodylians are generally thought to have wider, shorter rostra than their wild counterparts. Interpreted to reflect morphological change in response to the conditions of captivity, this qualitative pattern could affect the utility of these animals in a variety of fields of research. However, due to relative ease of access and availability of life history data, captive animals are often utilized in actualistic research. Thus, this issue should be addressed in more detail. Here we explore snout shape variation between captive and wild members of Alligator mississippiensis using two-dimensional (2D) morphometric techniques. Several landmark schemesare used to assess the utility of different aspects of morphology in distinguishing the groups. While statistical analyses consistently differentiated between the groups, the area of morphospace occupied by wild members of A. mississippiensis generally overlapped with the larger area encompassing the captive specimens. This indicates that the captive condition is not as uniform as previously thought and instead encompasses a large spectrum of morphologies, ranging from the stereotypical broad, shortened snouts to outlines that are indistinguishable from the wild morphotype. These results align well with the interpretation that this change reflects an extreme example of ecophenotypy, since ranched, farmed, or zoo organisms are held in an array of enclosures, ranging from indoor, climate controlled pens to outdoor, more natural areas. This variation in environments should be reflected in different reactions to the animals' surroundings, resulting in a broad spectrum of morphotypes. While wild specimens are still preferred, especially for fine scale analyses, these results indicate that not all captive members of A. mississippiensis exhibit the extreme morphological alterations often cited in the literature. Weighing the conditions in which the animals are held and exploring the possibility of morphological differences against the benefits of using captive specimens should be part of any actualistic study. J. Morphol. 277:866-878, 2016. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Processes underpinning development and maintenance of diversity in rice in West Africa: evidence from combining morphological and molecular markers.

PubMed

Mokuwa, Alfred; Nuijten, Edwin; Okry, Florent; Teeken, Béla; Maat, Harro; Richards, Paul; Struik, Paul C

2014-01-01

We assessed the interplay of artificial and natural selection in rice adaptation in low-input farming systems in West Africa. Using 20 morphological traits and 176 molecular markers, 182 farmer varieties of rice (Oryza spp.) from 6 West African countries were characterized. Principal component analysis showed that the four botanical groups (Oryza sativa ssp. indica, O. sativa ssp. japonica, O. glaberrima, and interspecific farmer hybrids) exhibited different patterns of morphological diversity. Regarding O. glaberrima, morphological and molecular data were in greater conformity than for the other botanical groups. A clear difference in morphological features was observed between O. glaberrima rices from the Togo hills and those from the Upper Guinea Coast, and among O. glaberrima rices from the Upper Guinea Coast. For the other three groups such clear patterns were not observed. We argue that this is because genetic diversity is shaped by different environmental and socio-cultural selection pressures. For O. glaberrima, recent socio-cultural selection pressures seemed to restrict genetic diversity while this was not observed for the other botanical groups. We also show that O. glaberrima still plays an important role in the selection practices of farmers and resulting variety development pathways. This is particularly apparent in the case of interspecific farmer hybrids where a relationship was found between pericarp colour, panicle attitude and genetic diversity. Farmer varieties are the product of long and complex trajectories of selection governed by local human agency. In effect, rice varieties have emerged that are adapted to West African farming conditions through genotype × environment × society interactions. The diversity farmers maintain in their rice varieties is understood to be part of a risk-spreading strategy that also facilitates successful and often serendipitous variety innovations. We advocate, therefore, that farmers and farmer varieties should be more effectively involved in crop development.

Processes Underpinning Development and Maintenance of Diversity in Rice in West Africa: Evidence from Combining Morphological and Molecular Markers

PubMed Central

Maat, Harro; Richards, Paul; Struik, Paul C.

2014-01-01

We assessed the interplay of artificial and natural selection in rice adaptation in low-input farming systems in West Africa. Using 20 morphological traits and 176 molecular markers, 182 farmer varieties of rice (Oryza spp.) from 6 West African countries were characterized. Principal component analysis showed that the four botanical groups (Oryza sativa ssp. indica, O. sativa ssp. japonica, O. glaberrima, and interspecific farmer hybrids) exhibited different patterns of morphological diversity. Regarding O. glaberrima, morphological and molecular data were in greater conformity than for the other botanical groups. A clear difference in morphological features was observed between O. glaberrima rices from the Togo hills and those from the Upper Guinea Coast, and among O. glaberrima rices from the Upper Guinea Coast. For the other three groups such clear patterns were not observed. We argue that this is because genetic diversity is shaped by different environmental and socio-cultural selection pressures. For O. glaberrima, recent socio-cultural selection pressures seemed to restrict genetic diversity while this was not observed for the other botanical groups. We also show that O. glaberrima still plays an important role in the selection practices of farmers and resulting variety development pathways. This is particularly apparent in the case of interspecific farmer hybrids where a relationship was found between pericarp colour, panicle attitude and genetic diversity. Farmer varieties are the product of long and complex trajectories of selection governed by local human agency. In effect, rice varieties have emerged that are adapted to West African farming conditions through genotype × environment × society interactions. The diversity farmers maintain in their rice varieties is understood to be part of a risk-spreading strategy that also facilitates successful and often serendipitous variety innovations. We advocate, therefore, that farmers and farmer varieties should be more effectively involved in crop development. PMID:24465809

Morphological and behavioral differences in the gastropod Trophon geversianus associated to distinct environmental conditions, as revealed by a multidisciplinary approach

NASA Astrophysics Data System (ADS)

Márquez, Federico; Nieto Vilela, Rocío Aimé; Lozada, Mariana; Bigatti, Gregorio

2015-01-01

The gastropod Trophon geversianus exhibits shell polymorphisms along its distribution in subtidal and intertidal habitats. Our hypothesis is that morphological and behavioral patterns of T. geversianus represent habitat-specific constrains; subsequently we expect an association between shell morphology, attachment behavior, and habitat. In order to test this hypothesis we compared individuals from intertidal and subtidal habitats, at three sites in Golfo Nuevo (Argentina). We analyzed shell morphology using classic morphometric variables, 3D geometric morphometrics and computing tomography scan. The results were complemented with field observations of attachment to substrate and turning time behavior, as well as of the number of shell scars produced by crab predation. Our results showed differences in shell size and shape between intertidal and subtidal-collected individuals. Centroid size, total weight and shell weight, as well as shell density and thickness were significantly lower in intertidal individuals than in subtidal ones. Gastropods from intertidal habitats presented a low-spired shell and an expanded aperture which might allow better attachment to the bottom substrate, while subtidal individuals presented a slender and narrower shell shape. The number of crab scars was significantly higher in shells from subtidal individuals. Observations of the behavior of gastropods placed at the intertidal splash zone showed 100% of attachment to the bottom in the intertidal individuals, while subtidal specimens only attached in average in 32% of the cases. These latter took 12 times longer to re-attach to the bottom when faced up. Phylogenetic analysis of COI gene fragments showed no consistent differences among individuals sampled in both habitats. All these results suggest that T. geversianus has developed two ecomorphs with distinct morphological and behavioral responses to physically stressful conditions registered in north Patagonian intertidals, as opposed to lower physical stress but higher predation pressure in the subtidal habitats. The findings of this work constitute a starting point in the study of ecological adaptation processes in gastropods from Patagonian coastal environments.

Corn stalks char from fast pyrolysis as precursor material for preparation of activated carbon in fluidized bed reactor.

PubMed

Wang, Zhiqi; Wu, Jingli; He, Tao; Wu, Jinhu

2014-09-01

Corn stalks char from fast pyrolysis was activated by physical and chemical activation process in a fluidized bed reactor. The structure and morphology of the carbons were characterized by N2 adsorption and SEM. Effects of activation time and activation agents on the structure of activation carbon were investigated. The physically activated carbons with CO2 have BET specific surface area up to 880 m(2)/g, and exhibit microporous structure. The chemically activated carbons with H3PO4 have BET specific surface area up to 600 m(2)/g, and exhibit mesoporous structure. The surface morphology shows that physically activated carbons exhibit fibrous like structure in nature with long ridges, resembling parallel lines. Whereas chemically activated carbons have cross-interconnected smooth open pores without the fibrous like structure. Copyright © 2014 Elsevier Ltd. All rights reserved.

Controllable synthesis and electrochemical hydrogen storage properties of Sb₂Se₃ ultralong nanobelts with urchin-like structures.

PubMed

Jin, Rencheng; Chen, Gang; Pei, Jian; Sun, Jingxue; Wang, Yang

2011-09-01

The controlled synthesis of one-dimensional and three-dimensional Sb(2)Se(3) nanostructures has been achieved by a facile solvothermal process in the presence of citric acid. By simply controlling the concentration of citric acid, the nucleation, growth direction and exposed facet can be readily tuned, which brings the different morphologies and nanostructures to the final products. The as-prepared products have been characterized by means of X-ray diffraction, field-emission scanning electron microscopy, transmission electron microscopy (TEM), high-resolution TEM and selected area electron diffraction. Based on the electron microscope observations, a possible growth mechanism of Sb(2)Se(3) with distinctive morphologies including ultralong nanobelts, hierarchical urchin-like nanostructures is proposed and discussed in detail. The electrochemical hydrogen storage measurements reveal that the morphology plays a key role on the hydrogen storage capacity of Sb(2)Se(3) nanostructures. The Sb(2)Se(3) ultralong nanobelts with high percentage of {-111} facets exhibit higher hydrogen storage capacity (228.5 mA h g(-1)) and better cycle stability at room temperature.

Synthesis and Characterization of 2-D Materials

NASA Astrophysics Data System (ADS)

Pazos, S.; Sahoo, P.; Afaneh, T.; Rodriguez Gutierrez, H.

Atomically thin transition-metal dichacogenides (TMD), graphene, and boron nitride (BN) are two-dimensional materials where the charge carriers (electrons and holes) are confined to move in a plane. They exhibit distinctive optoelectronic properties compared to their bulk layered counterparts. When combined into heterostructures, these materials open more possibilities in terms of new properties and device functionality. In this work, WSe2 and graphene were grown using Chemical Vapor Deposition (CVD) and Physical Vapor Deposition (PVD) techniques. The quality and morphology of each material was checked using Raman, Photoluminescence Spectroscopy, and Scanning Electron Microscopy. Graphene had been successfully grown homogenously, characterized, and transferred from copper to silicon dioxide substrates; these films will be used in future studies to build 2-D devices. Different morphologies of WSe2 2-D islands were successfully grown on SiO2 substrates. Depending on the synthesis conditions, the material on each sample had single layer, double layer, and multi-layer areas. A variety of 2-D morphologies were also observed in the 2-D islands. This project is supported by the NSF REU Grant #1560090 and NSF Grant #DMR-1557434.

Effect of cooling rates on the structure, density and micro-indentation behavior of the Fe, Co-based bulk metallic glass

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lesz, Sabina, E-mail: sabina.lesz@polsl.pl

The experiments demonstrate that ductility of the samples of bulk metallic glass (BMG) with the same chemical composition increased with decreasing sample size. It is shown that microhardness and density increases with decreasing the cooling rate. The fracture morphology of rods after compressive fracture were different on the cross section. Two characteristic features of the compressive fracture morphologies of metallic glasses (MGs) were observed in samples: smooth region and the vein pattern. Many parallel shear bands were observed on the deformed specimen with ϕ = 2 mm in diameter. The results provide more understanding on the relationship among the coolingmore » rate, structure and micro-indentation behavior of the Fe-Co-based BMGs. - Highlights: •Fracture morphology and micro-indentation behavior is studied. •The smaller BMG sample exhibits the larger plasticity. •Microhardness and density increase with decreasing the cooling rate. •Formation of shear bands has been reported in deformed specimens. •Structure and mechanical properties of BMGs can be controlled by the cooling rate.« less

Ternary blend polymer solar cells with self-assembled structure for enhancing power conversion efficiency

NASA Astrophysics Data System (ADS)

Yang, Zhenhua; Li, Hongfei; Nam, Chang-Yong; Kisslinger, Kim; Satija, Sushil; Rafailovich, Miriam

Bulk heterojunction (BHJ) polymer solar cells are an area of intense interest due to their advantages such as mechanical flexibility. The active layer is typically spin coated from the solution of polythiophene derivatives (donor) and fullerenes (acceptor) and interconnected domains are formed because of phase separation. However, the power conversion efficiency (PCE) of BHJ solar cell is restricted by the disordered inner structures in the active layer, donor or acceptor domains isolated from electrodes. Here we report a self-assembled columnar structure formed by phase separation between (PCDTBT) and polystyrene (PS) for the active layer morphology optimization. The BHJ solar cell device based on this structure is promising for exhibiting higher performance due to the shorter carrier transportation pathway and larger interfacial area between donor and acceptor. The surface morphology is investigated with atomic force microscopy (AFM) and the columnar structure is studied by investigation of cross-section of the blend thin film of PCDTBT and PS under the transmission electron microscopy (TEM). The different morphological structures formed via phase segregation are correlated with the performance of the BHJ solar cells.

Ultrasonic assisted production of starch nanoparticles: Structural characterization and mechanism of disintegration.

PubMed

Boufi, Sami; Bel Haaj, Sihem; Magnin, Albert; Pignon, Frédéric; Impéror-Clerc, Marianne; Mortha, Gérard

2018-03-01

In this paper, the disintegration of starch (waxy and standard starch) granules into nanosized particles under the sole effect of high power ultrasonication treatment in water/isopropanol is investigated, by using wide methods of analysis. The present work aims at a fully characterization of the starch nanoparticles produced by ultrasonication, in terms of size, morphology and structural properties, and the proposition of a possible mechanism explaining the top-down generation of starch nanoparticles (SNPs) via high intensity ultrasonication. Dynamic light scattering measurements have indicated a leveling of the particle size to about 40nm after 75min of ultrasonication. The WAXD, DSC and Raman have revealed the amorphous character of the SNPs. FE-SEM. AFM observations have confirmed the size measured by DLS and suggested that SNPs exhibited 2D morphology of platelet-like shapes. This morphology is further supported by SAXS. On the basis of data collected from the different characterization techniques, a possible mechanism explaining the disintegration process of starch granules into NPs is proposed. Copyright © 2017 Elsevier B.V. All rights reserved.

Correlation between oxidant concentrations, morphological aspects and etching kinetics of silicon nanowires during silver-assist electroless etching

NASA Astrophysics Data System (ADS)

Moumni, Besma; Jaballah, Abdelkader Ben

2017-12-01

Silicon porosification by silver assisted chemical etching (Ag-ACE) for a short range of H2O2 concentration is reported. We experimentally show that porous silicon (PSi) is obtained for 1% H2O2, whereas silicon nanowires (SiNWs) appeared by simply tuning the concentration of H2O2 to relatively high concentrations up to 8%. The morphological aspects are claimed by scanning electron microscopy proving that the kinetics of SiNWs formation display nonlinear relationships versus H2O2 concentration and etching time. A semi-qualitative electrochemical etching model based on local anodic, Ic, and cathodic, Ia, currents is proposed to explain the different morphological changes, and to unveil the formation pathways of both PS and SiNWs. More importantly, an efficient antireflective character for silicon solar cell (reflectance close to 2%) is realized at 8% H2O2. In addition, the luminescence of the prepared Si-nanostructures is claimed by photoluminescence which exhibit a large enhancement of the intensity and a blue shift for narrow and deep SiNWs.

Disrupted behaviour in grammatical morphology in French speakers with autism spectrum disorders.

PubMed

Le Normand, Marie-Thérèse; Blanc, Romuald; Caldani, Simona; Bonnet-Brilhault, Frédérique

2018-01-18

Mixed and inconsistent findings have been reported across languages concerning grammatical morphology in speakers with Autism Spectrum Disorders (ASD). Some researchers argue for a selective sparing of grammar whereas others claim to have identified grammatical deficits. The present study aimed to investigate this issue in 26 participants with ASD speaking European French who were matched on age, gender and SES to 26 participants with typical development (TD). The groups were compared regarding their productivity and accuracy of syntactic and agreement categories using the French MOR part-of-speech tagger available from the CHILDES. The groups significantly differed in productivity with respect to nouns, adjectives, determiners, prepositions and gender markers. Error analysis revealed that ASD speakers exhibited a disrupted behaviour in grammatical morphology. They made gender, tense and preposition errors and they omitted determiners and pronouns in nominal and verbal contexts. ASD speakers may have a reduced sensitivity to perceiving and processing the distributional structure of syntactic categories when producing grammatical morphemes and agreement categories. The theoretical and cross-linguistic implications of these findings are discussed.

Effect of the Cold-Sprayed Aluminum Coating-Substrate Interface Morphology on Bond Strength for Aircraft Repair Application

NASA Astrophysics Data System (ADS)

Blochet, Quentin; Delloro, Francesco; N'Guyen, Franck; Jeulin, Dominique; Borit, François; Jeandin, Michel

2017-04-01

This article is dealing with the effects of surface preparation of the substrate on aluminum cold-sprayed coating bond strength. Different sets of AA2024-T3 specimens have been coated with pure Al 1050 feedstock powder, using a conventional cold spray coating technique. The sets were grit-blasted (GB) before coating. The study focuses on substrate surface topography evolution before coating and coating-substrate interface morphology after coating. To study coating adhesion by LASAT® technique for each set, specimens with and without preceding GB treatment were tested in load-controlled conditions. Then, several techniques were used to evaluate the effects of substrate surface treatment on the final coating mechanical properties. Irregularities induced by the GB treatment modify significantly the interface morphology. Results showed that particle anchoring was improved dramatically by the presence of craters. The substrate surface was characterized by numerous anchors. Numerical simulation results exhibited the increasing deformation of particle onto the grit-blasted surface. In addition, results showed a strong relationship between the coating-substrate bond strength on the deposited material and surface preparation.

Control of dental-derived induced pluripotent stem cells through modified surfaces for dental application.

PubMed

Choi, Hyunmin; Park, Kyu-Hyung; Lee, Ah-Reum; Mun, Chin Hee; Shin, Yong Dae; Park, Yong-Beom; Park, Young-Bum

2017-07-01

The aim of this study is to investigate the behaviour of iPSc derived from dental stem cells in terms of initial adhesion, differentiation potential on differently surface-treated titanium disc. iPSc derived from human gingival fibroblasts (hGFs) were established using 4-reprogramming factors transduction with Sendai virus. The hGF-iPSc established in this study exhibited the morphology and growth properties similar to human embryonic stem (ES) cells and expressed pluripotency makers. Alkaline Phosphatase (AP) staining, Embryoid Body (EB) formation and in vitro differentiation and karyotyping further confirmed pluripotency of hGF-iPSc. Then, hGF-iPSc were cultured on machined- and Sandblasted and acid etched (SLA)-treated titanium discs with osteogenic induction medium and their morphological as well as quantitative changes according to different surface types were investigated using Alizrin Red S staining, Scanning electron microscopy (SEM), Flow cytometry and RT-PCR. Time-dependent and surface-dependent morphological changes as well as quantitative change in osteogenic differentiation of hGF-iPSc were identified and osteogenic gene expression of hGF-iPSc cultured on SLA-treated titanium disc found to be greater than machined titanium disc, suggesting the fate of hGF-iPSc may be determined by the characteristics of surface to which hGF-iPSc first adhere. iPSc derived from dental stem cell can be one of the most promising and practical cell sources for personalized regenerative dentistry and their morphological change as well as quantitative change in osteogenic differentiation according to different surface types may be further utilized for future clinical application incorporated with dental implant.

Differences in hydraulic architecture between mesic and xeric Pinus pinaster populations at the seedling stage.

PubMed

Corcuera, Leyre; Gil-Pelegrín, Eustaquio; Notivol, Eduardo

2012-12-01

We studied the intraspecific variability of maritime pine in a set of morphological and physiological traits: soil-to-leaf hydraulic conductance, intrinsic water-use efficiency (WUE, estimated by carbon isotope composition, δ(13)C), root morphology, xylem anatomy, growth and carbon allocation patterns. The data were collected from Pinus pinaster Aiton seedlings (25 half-sib families from five populations) grown in a greenhouse and subjected to water and water-stress treatments. The aims were to relate this variability to differences in water availability at the geographic location of the populations, and to study the potential trade-offs among traits. The drought-stressed seedlings demonstrated a decrease in hydraulic conductance and root surface area and increased WUE and root tip number. The relationships among the growth, morphological, anatomical and physiological traits changed with the scale of study: within the species, among/within populations. The populations showed a highly significant relationship between the percentage reduction in whole-plant hydraulic conductance and WUE. The differences among the populations in root morphology, whole-plant conductance, carbon allocation, plant growth and WUE were significant and consistent with dryness of the site of seed origin. The xeric populations exhibited lower growth and a conservative water use, as opposed to the fast-growing, less water-use-efficient populations from mesic habitats. The xeric and mesic populations, Tamrabta and San Cipriano, respectively, showed the most contrasting traits and were clustered in opposite directions along the main axis in the canonical discriminant analysis under both the control and drought treatments. The results suggest the possibility of selecting the Arenas population, which presents a combination of traits that confer increased growth and drought resistance.

Morphological divergence between three Arctic charr morphs - the significance of the deep-water environment.

PubMed

Skoglund, Sigrid; Siwertsson, Anna; Amundsen, Per-Arne; Knudsen, Rune

2015-08-01

Morphological divergence was evident among three sympatric morphs of Arctic charr (Salvelinus alpinus (L.)) that are ecologically diverged along the shallow-, deep-water resource axis in a subarctic postglacial lake (Norway). The two deep-water (profundal) spawning morphs, a benthivore (PB-morph) and a piscivore (PP-morph), have evolved under identical abiotic conditions with constant low light and temperature levels in their deep-water habitat, and were morphologically most similar. However, they differed in important head traits (e.g., eye and mouth size) related to their different diet specializations. The small-sized PB-morph had a paedomorphic appearance with a blunt head shape, large eyes, and a deep body shape adapted to their profundal lifestyle feeding on submerged benthos from soft, deep-water sediments. The PP-morph had a robust head, large mouth with numerous teeth, and an elongated body shape strongly related to their piscivorous behavior. The littoral spawning omnivore morph (LO-morph) predominantly utilizes the shallow benthic-pelagic habitat and food resources. Compared to the deep-water morphs, the LO-morph had smaller head relative to body size. The LO-morph exhibited traits typical for both shallow-water benthic feeding (e.g., large body depths and small eyes) and planktivorous feeding in the pelagic habitat (e.g., streamlined body shape and small mouth). The development of morphological differences within the same deep-water habitat for the PB- and PP-morphs highlights the potential of biotic factors and ecological interactions to promote further divergence in the evolution of polymorphism in a tentative incipient speciation process. The diversity of deep-water charr in this study represents a novelty in the Arctic charr polymorphism as a truly deep-water piscivore morph has to our knowledge not been described elsewhere.

PHOTOSYNTHETIC PIGMENT AND GENETIC DIFFERENCES BETWEEN TWO SOUTHERN OCEAN MORPHOTYPES OF EMILIANIA HUXLEYI (HAPTOPHYTA)1.

PubMed

Cook, Suellen S; Whittock, Lucy; Wright, Simon W; Hallegraeff, Gustaaf M

2011-06-01

The widespread coccolithophorid Emiliania huxleyi (Lohmann) W. W. Hay et H. Mohler plays a pivotal role in the carbon pump and is known to exhibit significant morphological, genetic, and physiological diversity. In this study, we compared photosynthetic pigments and morphology of triplicate strains of Southern Ocean types A and B/C. The two morphotypes differed in width of coccolith distal shield elements (0.11-0.24 μm, type A; 0.06-0.12 μm, type B/C) and morphology of distal shield central area (grill of curved rods in type A; thin plain plate in type B/C) and showed differences in carotenoid composition. The mean 19'-hexanoyloxyfucoxanthin (Hex):chl a ratio in type B/C was >1, whereas the type A ratio was <1. The Hex:fucoxanthin (fuc) ratio for type B/C was 11 times greater than that for type A, and the proportion of fuc in type A was 6 times higher than that in type B/C. The fuc derivative 4-keto-19'-hexanoyloxyfucoxanthin (4-keto-hex) was present in type A but undetected in B/C. DNA sequencing of tufA distinguished morphotypes A, B/C (indistinguishable from B), and R, while little variation was observed within morphotypes. Thirty single nucleotide polymorphisms were identified in the 710 bp tufA sequence, of which 10 alleles were unique to B/C and B morphotypes, seven alleles were unique to type A, and six alleles were unique to type R. We propose that the morphologically, physiologically, and genetically distinct Southern Ocean type B/C sensu Young et al. (2003) be classified as E. huxleyi var. aurorae var. nov. S. S. Cook et Hallegr. © 2011 Phycological Society of America.

Morphological Similarity and Ecological Overlap in Two Rotifer Species

PubMed Central

Gabaldón, Carmen; Montero-Pau, Javier; Serra, Manuel; Carmona, María José

2013-01-01

Co-occurrence of cryptic species raises theoretically relevant questions regarding their coexistence and ecological similarity. Given their great morphological similitude and close phylogenetic relationship (i.e., niche retention), these species will have similar ecological requirements and are expected to have strong competitive interactions. This raises the problem of finding the mechanisms that may explain the coexistence of cryptic species and challenges the conventional view of coexistence based on niche differentiation. The cryptic species complex of the rotifer Brachionus plicatilis is an excellent model to study these questions and to test hypotheses regarding ecological differentiation. Rotifer species within this complex are filtering zooplankters commonly found inhabiting the same ponds across the Iberian Peninsula and exhibit an extremely similar morphology—some of them being even virtually identical. Here, we explore whether subtle differences in body size and morphology translate into ecological differentiation by comparing two extremely morphologically similar species belonging to this complex: B. plicatilis and B. manjavacas. We focus on three key ecological features related to body size: (1) functional response, expressed by clearance rates; (2) tolerance to starvation, measured by growth and reproduction; and (3) vulnerability to copepod predation, measured by the number of preyed upon neonates. No major differences between B. plicatilis and B. manjavacas were found in the response to these features. Our results demonstrate the existence of a substantial niche overlap, suggesting that the subtle size differences between these two cryptic species are not sufficient to explain their coexistence. This lack of evidence for ecological differentiation in the studied biotic niche features is in agreement with the phylogenetic limiting similarity hypothesis but requires a mechanistic explanation of the coexistence of these species not based on differentiation related to biotic niche axes. PMID:23451154

Conidiogenesis-related DNA photolyase gene in Beauveria bassiana.

PubMed

Lee, Se Jin; Lee, Mi Rong; Kim, Sihyeon; Kim, Jong Cheol; Park, So Eun; Shin, Tae Young; Kim, Jae Su

2018-03-01

Beauveria bassiana is an entomopathogenic fungi used in environmentally mindful pest management. Its main active ingredient, conidia, is commercially available as a fungal biopesticide. Many studies of conidia production have focused on how to optimize culture conditions for maximum productivity and stability against unfavorable abiotic factors. However, understanding of how conidiogenesis-related genes provide improved conidial production remains unclear. In this study, we focus on identifying conidiogenesis-related genes in B. bassiana ERL1170 using a random mutagenesis technique. Transformation of ERL1170 using restriction enzyme-mediated integration generated one morphologically different transformant, ERL1170-pABeG #163. The transformant was confirmed to represent B. bassiana, and the binary vector was successfully integrated into the genome of ERL1170. Compared to the wild type, transformant #163 showed very slow hyphal growth and within 6 days only produced <1 × 10 6  conidia/0.28 cm 2 agar block (wild type: 6.2 × 10 7  conidia/agar block). Transformant #163 also exhibited different morphology than the wild type, including thicker hyphae with some club-shaped parts. In contrast, the typical morphology of wild type B. bassiana exhibits thread-like hyphae and conidiophore structures and circular conidia. To determine the location of the randomly inserted DNA, we conducted thermal asymmetric interlaced (TAIL) PCR and Escherichia coli cloning to clearly sequence the disrupted region. We identified one colony (colony No. 7) with an insertion site identified as DNA photolyase. This was confirmed through a gene knock-out study. It is possible the gene that encodes for DNA photolyase was disrupted during the insertion process and might be involved in fungal conidiogenesis. This work serves as a platform for exploring the function of a variety of B. bassiana genes involved in pest management and their downstream processing. Copyright © 2018 Elsevier Inc. All rights reserved.

Craniofacial morphology of Homo floresiensis: description, taxonomic affinities, and evolutionary implication.

PubMed

Kaifu, Yousuke; Baba, Hisao; Sutikna, Thomas; Morwood, Michael J; Kubo, Daisuke; Saptomo, E Wahyu; Jatmiko; Awe, Rokhus Due; Djubiantono, Tony

2011-12-01

This paper describes in detail the external morphology of LB1/1, the nearly complete and only known cranium of Homo floresiensis. Comparisons were made with a large sample of early groups of the genus Homo to assess primitive, derived, and unique craniofacial traits of LB1 and discuss its evolution. Principal cranial shape differences between H. floresiensis and Homo sapiens are also explored metrically. The LB1 specimen exhibits a marked reductive trend in its facial skeleton, which is comparable to the H. sapiens condition and is probably associated with reduced masticatory stresses. However, LB1 is craniometrically different from H. sapiens showing an extremely small overall cranial size, and the combination of a primitive low and anteriorly narrow vault shape, a relatively prognathic face, a rounded oval foramen that is greatly separated anteriorly from the carotid canal/jugular foramen, and a unique, tall orbital shape. Whereas the neurocranium of LB1 is as small as that of some Homo habilis specimens, it exhibits laterally expanded parietals, a weak suprameatal crest, a moderately flexed occipital, a marked facial reduction, and many other derived features that characterize post-habilis Homo. Other craniofacial characteristics of LB1 include, for example, a relatively narrow frontal squama with flattened right and left sides, a marked frontal keel, posteriorly divergent temporal lines, a posteriorly flexed anteromedial corner of the mandibular fossa, a bulbous lateral end of the supraorbital torus, and a forward protruding maxillary body with a distinct infraorbital sulcus. LB1 is most similar to early Javanese Homo erectus from Sangiran and Trinil in these and other aspects. We conclude that the craniofacial morphology of LB1 is consistent with the hypothesis that H. floresiensis evolved from early Javanese H. erectus with dramatic island dwarfism. However, further field discoveries of early hominin skeletal remains from Flores and detailed analyses of the finds are needed to understand the evolutionary history of this endemic hominin species. Copyright © 2011 Elsevier Ltd. All rights reserved.

Pinus Monophylla (Single Needled Pinyon Pine) show morphological changes in needle cell size and stomata over the past 100 years of rising CO2 in Western Arid Ecosystems.

NASA Astrophysics Data System (ADS)

Van De Water, P. K.

2016-12-01

The size, frequency, and morphology of leaf surface stomata is used to reconstruct past levels of atmospheric carbon dioxide over geologic time. This technique relies on measuring cell and cell-clusters to correlate with changes of known carbon dioxide levels in the atmosphere. Unfortunately, not all plants are suitable because the occurrence and placement of stomatal cell-complexes differ significantly between plant families. Monocot and dicot angiosperms exhibit different types of stomata and stomatal complexes that lack order and thus are unsuitable. But, in gymnosperms, the number and distribution of stomata and pavement cells is formalized and can be used to reconstruct past atmospheric carbon dioxide levels. However, characteristic of each plant species must still be considered. For example, conifers are useful but are divided into two-needle to five-needle pines, or have irregular surface morphology (Pseudotsuga sp. and Tsuga sp. needles). This study uses Pinus monophylla an undivided needle morphology, that being a cylinder has no interior surface cells. Pinus monophylla (single needle pinyon) needles were collected along Geiger Grade (Nevada State Highway 341, Reno) in 2005 and 2013 from 1500m to 2195m. Herbarium samples were also collected from 13 historic collections made between 1911 and 1994. The study determined changes with elevation and/or over time using in these populations. Using Pinus monophylla, insured needles represented a single surface with stomata, stomatal complex cells, and co-occurring pavement cell types. Results show decreased stomatal densities (stomata/area), stomatal index (stomata/stomata + epidermal cells) and stable stomata per row (stomata/row) . Epidermal cell density (Epidermal Cells /Area), and Pavement cell density (Pavement cell/area) track stomatal density similarly. Data comparison, using elevation in the 2005 and 2013 collections showed no-significant trends. Individual stomatal complexes show no differences in the size and shape over time or with elevation. Stomata morphology and the stomatal pores appear conservative. However some complex cells show a morphology suggesting they are not fully formed and functional. These characteristics appear often in the modern material suggesting some stomata never fully develop.

In vivo administration of fluorescent dextrans for the specific and sensitive localization of brain vascular pericytes and their characterization in normal and neurotoxin exposed brains.

PubMed

Sarkar, Sumit; Schmued, Larry

2012-06-01

We have aimed to develop novel histochemical markers for the labeling of brain pericytes and characterize their morphology in the normal and the excitotoxin-exposed brain, as this class of cells has received little attention until recently. Pericyte labeling was accomplished by the intracerebroventricular injection of certain fluorescent dextran conjugates, such as Fluoro-Gold-dextran, FR-dextran, FITC-dextran and Fluoro-Turquoise (FT)-dextran. 1-7 days after the tracer injection, extensive labeling of vascular pericytes was seen throughout the entire brain. These cells were found distal to the endothelial cells and exhibited large dye containing vacuoles. The morphology of the pericytes was somewhat variable, exhibiting round or amoeboid shapes within larger intracellular vesicles, while those wrapping around capillaries exhibited a more elongated appearance with finger-like projections. The use of FG-dextran resulted in bluish yellow fluorescently labeled pericytes, while FR-dextran resulted in red fluorescent labeled pericytes, FITC-dextran exhibited green fluorescent pericytes and FT-dextran showed fluorescent blue pericytes in the brain. We have used these tracers to study possible changes in morphology and pericyte number following kainic acid insult, observing that the number of pericytes in the injured or lesioned areas of the brain is dramatically reduced compared to the non-injured areas. These novel fluorochromes should be of use for studies involving the detection and localization of pericytes in both normal and pathological brain tissues. Published by Elsevier B.V.

Palladium nanoparticles functionalized graphene nanosheets for Li-O2 batteries: enhanced performance by tailoring the morphology of discharge product

NASA Astrophysics Data System (ADS)

Wang, Liangjun; Chen, Wei; SSL Team

Lithium oxygen (Li-O2) batteries represent a promising candidate for the next generation electric vehicle.1-3 Despite the attractive prospect, some issues including large overpotentials, poor recyclability and unstable electrolyte4-6 limit the wide applications of Li-O2 batteries. Due to the insoluble and non-conductive nature of discharge product Li2O2, it has been widely accepted that the performance of oxygen evolution reaction (OER) process is not only determined by the catalyst itself but also close linked to morphology and electronic conductivity of Li2O2 formed during oxygen reduction reaction (ORR) process. Herein, we report a strategy to improve the battery performance by tailoring the morphology of discharge product. By using graphene nanosheets (GNSs) functionalized with Pd nanoparticles (NPs) as cathode catalyst, the growth and morphology of the discharge products of Li2O2 can be effectively tailored, thereby leading to the improved Li-O2 battery performance. Surprisingly, on bare GNSs cathode, the discharge product showed widely observed large-sized toroidal morphology. While for Pd NPs functionalized GNSs, the discharge product was homogenously distributed on the cathode in the form of small nanoparticles with an average diameter of 25 nm. As a result, Pd NPs functionalized GNSs exhibited a high discharge capacity of 7690 mAh g-1. Meanwhile, the battery with tailored morphology exhibits lower charge overpotential.

Trench motion-controlled slab morphology and stress variations: Implications for the isolated 2015 Bonin Islands deep earthquake

NASA Astrophysics Data System (ADS)

Yang, Ting; Gurnis, Michael; Zhan, Zhongwen

2017-07-01

The subducted old and cold Pacific Plate beneath the young Philippine Sea Plate at the Izu-Bonin trench over the Cenozoic hosts regional deep earthquakes. We investigate slab morphology and stress regimes under different trench motion histories with mantle convection models. Viscosity, temperature, and deviatoric stress are inherently heterogeneous within the slab, which we link to the occurrence of isolated earthquakes. Models expand on previous suggestions that observed slab morphology variations along the Izu-Bonin subduction zone, exhibited as shallow slab dip angles in the north and steeper dip angles in the south, are mainly due to variations in the rate of trench retreat from the north (where it is fast) to the south (where it is slow). Geodynamic models consistent with the regional plate tectonics, including oceanic plate age, plate convergence rate, and trench motion history, reproduce the seismologically observed principal stress direction and slab morphology. We suggest that the isolated 680 km deep, 30 May 2015 Mw 7.9 Bonin Islands earthquake, which lies east of the well-defined Benioff zone and has its principal compressional stress direction oriented toward the tip of the previously defined Benioff zone, can be explained by Pacific slab buckling in response to the slow trench retreat.

Morphology-Variable Aggregates Prepared from Cholesterol-Containing Amphiphilic Glycopolymers: Their Protein Recognition/Adsorption and Drug Delivery Applications

PubMed Central

Wang, Zhao; Luo, Ting; Cao, Amin; Sun, Jingjing; Jia, Lin

2018-01-01

In this study, a series of diblock glycopolymers, poly(6-O-methacryloyl-d-galactopyranose)-b-poly(6-cholesteryloxyhexyl methacrylate) (PMAgala-b-PMAChols), with cholesterol/galactose grafts were prepared through a sequential reversible addition-fragmentation chain transfer (RAFT) polymerization and deprotection process. The glycopolymers could self-assemble into aggregates with various morphologies depending on cholesterol/galactose-containing block weight ratios, as determined by transmission electronic microscopy (TEM) and dynamic laser light scattering (DLS). In addition, the lectin (Ricinus communis agglutinin II, RCA120) recognition and bovine serum albumin (BSA) adsorption of the PMAgala-b-PMAChol aggregates were evaluated. The SK-Hep-1 tumor cell inhibition properties of the PMAgala-b-PMAChol/doxorubicin (DOX) complex aggregates were further examined in vitro. Results indicate that the PMAgala-b-PMAChol aggregates with various morphologies showed different interaction/recognition features with RCA120 and BSA. Spherical aggregates (d ≈ 92 nm) possessed the highest RCA120 recognition ability and lowest BSA protein adsorption. In addition, the DOX-loaded spherical complex aggregates exhibited a better tumor cell inhibition property than those of nanofibrous complex aggregates. The morphology-variable aggregates derived from the amphiphilic glycopolymers may serve as multifunctional biomaterials with biomolecular recognition and drug delivery features. PMID:29495614

Influence of carbon nanoparticle modification on the mechanical and electrical properties of epoxy in small volumes.

PubMed

Leopold, Christian; Augustin, Till; Schwebler, Thomas; Lehmann, Jonas; Liebig, Wilfried V; Fiedler, Bodo

2017-11-15

The influence of nanoparticle morphology and filler content on the mechanical and electrical properties of carbon nanoparticle modified epoxy is investigated regarding small volumes. Three types of particles, representing spherical, tubular and layered morphologies are used. A clear size effect of increasing true failure strength with decreasing volume is found for neat and carbon black modified epoxy. Carbon nanotube (CNT) modified epoxy exhibits high potential for strength increase, but dispersion and purity are critical. In few layer graphene modified epoxy, particles are larger than statistically distributed defects and initiate cracks, counteracting any size effect. Different toughness increasing mechanisms on the nano- and micro-scale depending on particle morphology are discussed based on scanning electron microscopy images. Electrical percolation thresholds in the small volume fibres are significantly higher compared to bulk volume, with CNT being found to be the most suitable morphology to form electrical conductive paths. Good correlation between electrical resistance change and stress strain behaviour under tensile loads is observed. The results show the possibility to detect internal damage in small volumes by measuring electrical resistance and therefore indicate to the high potential for using CNT modified polymers in fibre reinforced plastics as a multifunctional, self-monitoring material with improved mechanical properties. Copyright © 2017. Published by Elsevier Inc.

Control of dissected leaf morphology by a Cys(2)His(2) zinc finger transcription factor in the model legume Medicago truncatula

PubMed Central

Yu, Jianbin; Ge, Liangfa; Wang, Hongliang; Berbel, Ana; Liu, Yu; Chen, Yuhui; Li, Guangming; Tadege, Million; Wen, Jiangqi; Cosson, Viviane; Mysore, Kirankumar S.; Ratet, Pascal; Madueño, Francisco; Bai, Guihua; Chen, Rujin

2010-01-01

Plant leaves are diverse in their morphology, reflecting to a large degree the plant diversity in the natural environment. How different leaf morphology is determined is not yet understood. The leguminous plant Medicago truncatula exhibits dissected leaves with three leaflets at the tip. We show that development of the trifoliate leaves is determined by the Cys(2)His(2) zinc finger transcription factor PALM1. Loss-of-function mutants of PALM1 develop dissected leaves with five leaflets clustered at the tip. We demonstrate that PALM1 binds a specific promoter sequence and down-regulates the expression of the M. truncatula LEAFY/UNIFOLIATA orthologue SINGLE LEAFLET1 (SGL1), encoding an indeterminacy factor necessary for leaflet initiation. Our data indicate that SGL1 is required for leaflet proliferation in the palm1 mutant. Interestingly, ectopic expression of PALM1 effectively suppresses the lobed leaf phenotype from overexpression of a class 1 KNOTTED1-like homeobox protein in Arabidopsis plants. Taken together, our results show that PALM1 acts as a determinacy factor, regulates the spatial-temporal expression of SGL1 during leaf morphogenesis and together with the LEAFY/UNIFOLIATA orthologue plays an important role in orchestrating the compound leaf morphology in M. truncatula. PMID:20498057

Spectral, thermal, XRD and SEM studies of charge-transfer complexation of hexamethylenediamine and three types of acceptors: π-, σ- and vacant orbital acceptors that include quinol, picric acid, bromine, iodine, SnCl4 and ZnCl2 acceptors

NASA Astrophysics Data System (ADS)

Adam, Abdel Majid A.; Refat, Moamen S.; Saad, Hosam A.

2013-11-01

In this work, structural, thermal, morphological and pharmacological characterization was performed on the interactions between a hexamethylenediamine (HMDA) donor and three types of acceptors to understand the complexation behavior of diamines. The three types of acceptors include π-acceptors (i.e., quinol (QL) and picric acid (PA)), σ-acceptors (i.e., bromine and iodine) and vacant orbital acceptors (i.e., tin(IV) tetrachloride (SnCl4) and zinc chloride (ZnCl2)). The characterization of the obtained CT complexes was performed using elemental analysis, infrared (IR), Raman, 1H NMR and electronic absorption spectroscopy, powder X-ray diffraction (XRD) and thermogravimetric (TG) analysis. Their morphologies were studied using scanning electron microscopy with energy-dispersive X-ray analysis (SEM-EDX). The biological activities of the obtained CT complexes were tested for their antibacterial activities. The complex containing the QL acceptor exhibited a remarkable electronic spectrum with a strong, broad absorption band, which had an observed λmax that was at a much longer wavelength than those of the free reactants. In addition, this complex exhibited strong antimicrobial activities against various bacterial and fungal strains compared to standard drugs. The complexes containing the PA, iodine, Sn(IV) and Zn(II) acceptors exhibited good thermal stability up to 240, 330, 275 and 295 °C, respectively. The complexes containing bromine, Sn(IV) and Zn(II) acceptors exhibited good crystallinity. In addition to its good crystallinity properties, the complex containing the bromine acceptor exhibits a remarkable morphology feature.

Evolution of Body Elongation in Gymnophthalmid Lizards: Relationships with Climate

PubMed Central

Grizante, Mariana B.; Brandt, Renata; Kohlsdorf, Tiana

2012-01-01

The evolution of elongated body shapes in vertebrates has intrigued biologists for decades and is particularly recurrent among squamates. Several aspects might explain how the environment influences the evolution of body elongation, but climate needs to be incorporated in this scenario to evaluate how it contributes to morphological evolution. Climatic parameters include temperature and precipitation, two variables that likely influence environmental characteristics, including soil texture and substrate coverage, which may define the selective pressures acting during the evolution of morphology. Due to development of geographic information system (GIS) techniques, these variables can now be included in evolutionary biology studies and were used in the present study to test for associations between variation in body shape and climate in the tropical lizard family Gymnophthalmidae. We first investigated how the morphological traits that define body shape are correlated in these lizards and then tested for associations between a descriptor of body elongation and climate. Our analyses revealed that the evolution of body elongation in Gymnophthalmidae involved concomitant changes in different morphological traits: trunk elongation was coupled with limb shortening and a reduction in body diameter, and the gradual variation along this axis was illustrated by less-elongated morphologies exhibiting shorter trunks and longer limbs. The variation identified in Gymnophthalmidae body shape was associated with climate, with the species from more arid environments usually being more elongated. Aridity is associated with high temperatures and low precipitation, which affect additional environmental features, including the habitat structure. This feature may influence the evolution of body shape because contrasting environments likely impose distinct demands for organismal performance in several activities, such as locomotion and thermoregulation. The present study establishes a connection between morphology and a broader natural component, climate, and introduces new questions about the spatial distribution of morphological variation among squamates. PMID:23166767

Description of congenital hand anomalies: a personal view.

PubMed

Tonkin, M A

2006-10-01

A series of four congenital hand cases exhibiting central clefting are presented. The cases are morphologically similar and exhibit characteristics of both symbrachydactyly and central longitudinal deficiency. The cases demonstrate difficulties in classification by either the IFSSH classification system or the JSSH modification of it. An alternative descriptive approach to classification is suggested.

Role of the nuclear migration protein Lis1 in cell morphogenesis in Ustilago maydis

PubMed Central

Valinluck, Michael; Ahlgren, Sara; Sawada, Mizuho; Locken, Kristopher; Banuett, Flora

2010-01-01

Ustilago maydis is a basidiomycete fungus that exhibits a yeast-like and a filamentous form. Growth of the fungus in the host leads to additional morphological transitions. The different morphologies are characterized by distinct nuclear movements. Dynein and α-tubulin are required for nuclear movements and for cell morphogenesis of the yeast-like form. Lis1 is a microtubule plus-end tracking protein (+TIPs) conserved in eukaryotes and required for nuclear migration and spindle positioning. Defects in nuclear migration result in altered cell fate and aberrant development in metazoans, slow growth in fungi and disease in humans (e.g. lissencephaly). Here we investigate the role of the human LIS1 homolog in U. maydis and demonstrate that it is essential for cell viability, not previously seen in other fungi. With a conditional null mutation we show that lis1 is necessary for nuclear migration in the yeast-like cell and during the dimorphic transition. Studies of asynchronous exponentially growing cells and time-lapse microscopy uncovered novel functions of lis1: It is necessary for cell morphogenesis, positioning of the septum and cell wall integrity. lis1-depleted cells exhibit altered axes of growth and loss of cell polarity leading to grossly aberrant cells with clusters of nuclei and morphologically altered buds devoid of nuclei. Altered septum positioning and cell wall deposition contribute to the aberrant morphology. lis1-depleted cells lyse, indicative of altered cell wall properties or composition. We also demonstrate, with indirect immunofluorescence to visualize tubulin, that lis1 is necessary for the normal organization of the microtubule cytoskeleton: lis1-depleted cells contain more and longer microtubules that can form coils perpendicular to the long axis of the cell. We propose that lis1 controls microtubule dynamics and thus the regulated delivery of vesicles to growth sites and other cell domains that govern nuclear movements. PMID:20524583

Photocatalytic activity of ZnWO₄: band structure, morphology and surface modification.

PubMed

Zhang, Cuiling; Zhang, Hulin; Zhang, Kaiyou; Li, Xiaoyan; Leng, Qiang; Hu, Chenguo

2014-08-27

Photocatalytic degradation of organic contaminants is an important application area in solar energy utilization. To improve material photocatalytic properties, understanding their photocatalytic mechanism is indispensable. Here, the photocatalytic performance of ZnWO4 nanocrystals was systematicly investigated by the photodegradation of tetraethylated rhodamine (RhB) under simulated sunlight irradiation, including the influence of morphology, AgO/ZnWO4 heterojunction and comparison with CoWO4 nanowires. The results show that the photocatalytic activity of ZnWO4 is higher than that of CoWO4, and the ZnWO4 nanorods exhibit better photocatalytic activity than that of ZnWO4 nanowires. In addition, the mechanism for the difference of the photocatalytic activity was also investigated by comparison of their photoluminescence and photocurrents. AgO nanoparticles were assembled uniformly on the surface of ZnWO4 nanowires to form a heterojunction that exhibited enhanced photocatalytic activity under irradiation at the initial stage. We found that a good photocatalyst should not only have an active structure for electrons directly to transfer from the valence band to the conduction band without the help of phonons but also a special electronic configuration for the high mobility, to ensure more excited electrons and holes in a catalytic reaction.

Effect of reaction atmosphere on structural and optical properties of hexagonal molybdenum oxide (h-MoO{sub 3})

DOE Office of Scientific and Technical Information (OSTI.GOV)

Doss, V. Arumai; Chithambararaj, A.; Bose, A. Chandra, E-mail: acbose@nitt.edu

2016-05-23

The present work aims to synthesize single phase h-MoO{sub 3} nanocrytals by chemical precipitation method exposed under different reaction atmospheres. The reaction atmosphere have been successfully tuned as air, nitrogen and argon and studied its effects on structural, functional, morphology and optical properties by using X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared (FT-IR) spectroscopy and diffuse reflectance spectroscopy (DRS) measurements. The XRD result indicates that the sample exhibits characteristic hexagonal phase of MoO{sub 3}. The crystallite size is estimated by well known Scherrer’s method. The crystallite size is relative small in the case of sample prepared atmore » argon atmosphere. The functional groups such as Mo-O, N-H and O-H are identified from FT-IR spectroscopy. The particle exhibits rod like morphology with perfect hexagonal cross-section. The optical absorption observed at 420-450 nm corresponds to fundamental optical absorption by h-MoO{sub 3}. The band gap values are estimated using Kublka-Munk (K-M) function and found to be 2. 87 eV, 2.93 eV and 2.97 eV for samples synthesized under air, nitrogen and argon, respectively.« less

Reversal of Myoblast Aging by Tocotrienol Rich Fraction Posttreatment

PubMed Central

Wan Ngah, Wan Zurinah; Mouly, Vincent; Abdul Karim, Norwahidah

2013-01-01

Skeletal muscle satellite cells are heavily involved in the regeneration of skeletal muscle in response to the aging-related deterioration of the skeletal muscle mass, strength, and regenerative capacity, termed as sarcopenia. This study focused on the effect of tocotrienol rich fraction (TRF) on regenerative capacity of myoblasts in stress-induced premature senescence (SIPS). The myoblasts was grouped as young control, SIPS-induced, TRF control, TRF pretreatment, and TRF posttreatment. Optimum dose of TRF, morphological observation, activity of senescence-associated β-galactosidase (SA-β-galactosidase), and cell proliferation were determined. 50 μg/mL TRF treatment exhibited the highest cell proliferation capacity. SIPS-induced myoblasts exhibit large flattened cells and prominent intermediate filaments (senescent-like morphology). The activity of SA-β-galactosidase was significantly increased, but the proliferation capacity was significantly reduced as compared to young control. The activity of SA-β-galactosidase was significantly reduced and cell proliferation was significantly increased in the posttreatment group whereas there was no significant difference in SA-β-galactosidase activity and proliferation capacity of pretreatment group as compared to SIPS-induced myoblasts. Based on the data, we hypothesized that TRF may reverse the myoblasts aging through replenishing the regenerative capacity of the cells. However, further investigation on the mechanism of TRF in reversing the myoblast aging is needed. PMID:24349615

Muscle contraction controls skeletal morphogenesis through regulation of chondrocyte convergent extension.

PubMed

Shwartz, Yulia; Farkas, Zsuzsanna; Stern, Tomer; Aszódi, Attila; Zelzer, Elazar

2012-10-01

Convergent extension driven by mediolateral intercalation of chondrocytes is a key process that contributes to skeletal growth and morphogenesis. While progress has been made in deciphering the molecular mechanism that underlies this process, the involvement of mechanical load exerted by muscle contraction in its regulation has not been studied. Using the zebrafish as a model system, we found abnormal pharyngeal cartilage morphology in both chemically and genetically paralyzed embryos, demonstrating the importance of muscle contraction for zebrafish skeletal development. The shortening of skeletal elements was accompanied by prominent changes in cell morphology and organization. While in control the cells were elongated, chondrocytes in paralyzed zebrafish were smaller and exhibited a more rounded shape, confirmed by a reduction in their length-to-width ratio. The typical columnar organization of cells was affected too, as chondrocytes in various skeletal elements exhibited abnormal stacking patterns, indicating aberrant intercalation. Finally, we demonstrate impaired chondrocyte intercalation in growth plates of muscle-less Sp(d) mouse embryos, implying the evolutionary conservation of muscle force regulation of this essential morphogenetic process.Our findings provide a new perspective on the regulatory interaction between muscle contraction and skeletal morphogenesis by uncovering the role of muscle-induced mechanical loads in regulating chondrocyte intercalation in two different vertebrate models. Copyright © 2012 Elsevier Inc. All rights reserved.

Preservation and detection of microstructural and taxonomic correlations in the carbon isotopic compositions of individual Precambrian microfossils

NASA Astrophysics Data System (ADS)

Williford, Kenneth H.; Ushikubo, Takayuki; Schopf, J. William; Lepot, Kevin; Kitajima, Kouki; Valley, John W.

2013-03-01

Here we present techniques for, and new data from, in situ carbon isotope (δ13C) analysis of Precambrian permineralized microscopic fossils with a reproducibility of 1-2‰ using secondary ion mass spectrometry (SIMS). Individual microfossils, selected for their excellent preservation, were analyzed in petrographic thin sections of stromatolitic cherts from the Proterozoic Gunflint (˜1880 Ma), Bitter Springs (˜830 Ma), Min'yar (˜740 Ma), and Chichkan (˜775 Ma) Formations. The range of δ13C values (-34.6‰ to -22.1‰ VPDB) among the 46 individuals analyzed falls within that expected for photoautotrophic carbon fixation by ribulose bisphosphate carboxylase (RuBisCO), consistent with morphology-based taxonomic assignments for these specimens. Microfossils classified as cyanobacteria from the Gunflint, Bitter Springs, and Min'yar Formations (for which published carbonate carbon isotope data can be used to estimate the δ13C of the original dissolved inorganic carbon substrate) exhibit a consistent ˜19‰ total fractionation (δ13C of dissolved inorganic carbon - δ13C of biomass) similar to that observed in living cyanobacteria, over a wide range of δ13Ccarb values (-2.9‰ to 3.4‰). In stromatolitic chert of the Min'yar Formation, morphologically diverse microfossils preserved in a ˜1 mm2 part of a microbial mat exhibit systematic isotopic differences among and within taxa that correlate with their morphologically inferred biological affinities and suggest that isotopic signatures of their original biosynthetic processes (e.g., lipid and peptidoglycan synthesis) are preserved. Isotopic offsets consistent with the different RuBisCO-based fractionations typical of cyanobacteria and photosynthetic eukaryotes are documented by the differing δ13C values of a colonial cyanobacterium (-22.6 ± 0.5‰) and a phytoplanktonic protistan acritarch (-28.9 ± 1.0‰) situated <1 cm apart in the stromatolitic Chichkan chert. These findings show for the first time the possibility of using in situ isotopic microanalysis of fossil microbial mats and ancient sediments in order to distinguish metabolic fingerprints within complex microbial ecosystems and consortia.

Antibacterial properties and cytocompatibility of tantalum oxide coatings with different silver content

DOE Office of Scientific and Technical Information (OSTI.GOV)

Huang, Heng-Li; Chang, Yin-Yu, E-mail: yinyu@mail2000.com.tw; Chen, Hung-Jui

Tantalum (Ta) oxides and their coatings have been proved to increase their applications in the biomedical fields by improving osseointegration and wear resistance. In this study, Ta oxide coatings containing different proportions of Ag are deposited on SS304 materials. A twin-gun magnetron sputtering system is used to deposit the tantalum oxide-Ag coating. In this study, Staphylococcus aureus, which exhibits physiological commensalism on the human skin, nares, and mucosal and oral areas, is chosen as the model for in vitro antibacterial analyses via a fluorescence staining method using Syto9. The cytocompatibility and adhesive morphology of human skin fibroblast cells (CCD-966SK) onmore » the coatings are also determined by using the microculture tetrazolium assay. This study shows that Ta{sub 2}O{sub 5} and Ta{sub 2}O{sub 5}-Ag coatings with 12.5 at. % of Ag exhibit improved antibacterial effects against S. aureus and have good skin fibroblast cell cellular biocompatibility.« less

Sedimentation of a two-dimensional colloidal mixture exhibiting liquid-liquid and gas-liquid phase separation: a dynamical density functional theory study.

PubMed

Malijevský, Alexandr; Archer, Andrew J

2013-10-14

We present dynamical density functional theory results for the time evolution of the density distribution of a sedimenting model two-dimensional binary mixture of colloids. The interplay between the bulk phase behaviour of the mixture, its interfacial properties at the confining walls, and the gravitational field gives rise to a rich variety of equilibrium and non-equilibrium morphologies. In the fluid state, the system exhibits both liquid-liquid and gas-liquid phase separation. As the system sediments, the phase separation significantly affects the dynamics and we explore situations where the final state is a coexistence of up to three different phases. Solving the dynamical equations in two-dimensions, we find that in certain situations the final density profiles of the two species have a symmetry that is different from that of the external potentials, which is perhaps surprising, given the statistical mechanics origin of the theory. The paper concludes with a discussion on this.

Neurodevelopmental Malformations of the Cerebellar Vermis in Genetically Engineered Rats.

PubMed

Ramos, Raddy L; Van Dine, Sarah E; Gilbert, Mary E; Leheste, Joerg R; Torres, German

2015-12-01

The cerebellar vermis is particularly vulnerable to neurodevelopmental malformations in humans and rodents. Sprague-Dawley, and Long-Evans rats exhibit spontaneous cerebellar malformations consisting of heterotopic neurons and glia in the molecular layer of the vermis. Malformations are almost exclusively found along the primary fissure and are indicative of deficits of neuronal migration during cerebellar development. In the present report, we test the prediction that genetically engineered rats on Sprague-Dawley or Long-Evans backgrounds will also exhibit the same cerebellar malformations. Consistent with our hypothesis, we found that three different transgenic lines on two different backgrounds had cerebellar malformations. Heterotopia in transgenic rats had identical cytoarchitecture as that observed in wild-type rats including altered morphology of Bergmann glia. In light of the possibility that heterotopia could affect results from behavioral studies, these data suggest that histological analyses be performed in studies of cerebellar function or development when using genetically engineered rats on these backgrounds in order to have more careful interpretation of experimental findings.

Internal Characteristics of Phobos and Deimos from Spectral Properties and Density: Relationship to Landforms and Comparison with Asteroids

NASA Technical Reports Server (NTRS)

Murchie, S. L.; Fraeman, A. A.; Arvidson, R. E.; Rivkin, A. S.; Morris, R. V.

2013-01-01

Compositional interpretations of new spectral measurements of Phobos and Deimos from Mars Express/OMEGA and MRO/CRISM and density measurements from encounters by multiple spacecraft support refined estimates of the moons' porosity and internal structure. Phobos' estimated macroporosity of 12-20% is consistent with a fractured but coherent interior; Deimos' estimated macroporosity of 23-44% is more consistent with a loosely consolidated interior. These internal differences are reflected in differences in surface morphology: Phobos exhibits a globally coherent pattern of grooves, whereas Deimos has a surface dominated instead by fragmental debris. Comparison with other asteroids .110 km in diameter shows that this correspondence between landforms and inferred internal structure is part of a pervasive pattern: asteroids interpreted to have coherent interiors exhibit pervasive, organized ridge or groove systems, whereas loosely consolidated asteroids have landforms dominated by fragmental debris and/or retain craters >1.3 body radii in diameter suggesting a porous, compressible interior.

An ecological interpretation of the difference in leaf anatomy and its plasticity in contrasting tree species in orange kloof, table mountain, South Africa.

PubMed

Hlwatika, C N M; Bhat, R B

2002-01-01

Leaf anatomy and morphology were studied in 11 tree species growing in an undisturbed forest and the adjoining fynbos for over 50 years. Functional anatomical results suggest that the forest and the fynbos are ecologically distinct. Moreover, leaf anatomy suggests that the foliage is primarily adapted for photosynthesis rather than for control of transpirational water loss. Forest precursor tree species and scrub species exhibit xeromorphy in the fynbos whereas they exhibit mesomorphic features inside the forest. The wide-ranging species, such as Olea capensis subsp. capensis, simulated the response of the forest precursors, with the cuticle being phenotypically plastic between the forest and the fynbos but not between the stream and non-stream habitats. Finally, the forest precursors, the scrub species, and the wide-ranging taxa seem to have anatomical characters which can be modified in the fynbos and therefore allow its colonization by a variety of different species.

Effect of different drying methods on chemical composition and bioactivity of tea polysaccharides.

PubMed

Wang, Yuanfeng; Liu, Yangyang; Huo, Jianglei; Zhaoa, Xintong; Zhao, Tingtong; Zheng, Jian; Ren, Jian; Wei, Xinlin

2013-11-01

Four polysaccharides (TPS-F, TPS-V, TPS-S and TPS-M) were obtained from tea (Camellia sinensis) leaves by freeze-drying, vacuum-drying, spray-drying and microwave-vacuum drying, respectively. Their chemical composition and biological properties were comparatively studied. The results showed these TPS were similar in IR, UV absorption and distribution of molecular weight. However, they showed significant differences (P<0.05) in yields of crude polysaccharides and contents of protein and total polyphenols. Furthermore, morphological analysis showed their surface differed from each other in size and shape when viewed by SEM, from which surface of TPS-F was rough and porous, surface of TPS-S was evenly particles, and surfaces of the other two were similar to anomalistic bricks. In addition, the bioactivity of them was also evaluated. It was found TPS-F exhibited relatively better ability on metal chelating and superoxide radicals scavenging assays than others, and TPS-V exhibited higher ability on α-glycosidase and α-amylase inhibition assays than others with inhibitory percentages of 82.75% and 92.8%. Copyright © 2013 Elsevier B.V. All rights reserved.

Comparative anatomy and evolution of the cardiac innervation in New World monkeys (Platyrrhini, e. Geoffroy, 1812).

PubMed

Kawashima, Tomokazu; Thorington, Richard W; Whatton, James F

2009-05-01

The morphology of the autonomic cardiac nervous system (ACNS) was examined in 24 sides of 12 New World monkeys (Platyrrhini) of all four families to document the morphology systematically and to study the evolutionary changes of the ACNS in this primate lineage. We report the following: (1) Although several trivial intra- and inter-specific variations are present, a family-dependent morphology of the ACNS does not exist in New World monkeys. (2) The sympathetic ganglia in New World monkeys consist of the superior cervical, the middle cervical, and the cervicothoracic which is composed of the inferior cervical and first and second thoracic, and the thoracic ganglia starting with the third thoracic. The general cardiac nervous system is the sympathetic middle and inferior cardiac nerves and all parasympathetic vagal cardiac branches. (3) The morphology of the ACNS in the New World monkeys is almost consistent regardless of the number of vertebrae, the cardiac position and deviation (axis), and the great arterial branching pattern of the aortic arch, and it is very similar to that in the Old World monkeys, with only one difference: the superior cervical ganglion in the New World monkeys tends to be relatively smaller, higher, and provides a narrower contribution to the spinal nerves than in the Old World monkeys. The ACNS morphology exhibits significant evolutionary changes within the primate lineage from New and Old World monkeys to humans. The comparative morphology within the lineage is concordant with the phylogeny, suggesting that the primate ACNS preserves its evolutionary history in close alignment with phylogeny.

Biogeography and molar morphology of Pleistocene African elephants: new evidence from Elandsfontein, Western Cape Province, South Africa

NASA Astrophysics Data System (ADS)

Smith, Kathlyn M.; Stynder, Deano D.

2015-05-01

Elandsfontein (EFT) is a Middle Pleistocene archaeological/paleontological site located in the Western Cape Province of South Africa. The largest herbivore in the assemblage is Loxodonta atlantica zulu, an extinct member of the genus that includes modern African elephants. No Elephas recki specimens were recovered at EFT, despite their common occurrence in other regions of Africa at the same time. Because E. recki and L. atlantica molars are similar in appearance, but the two species are traditionally viewed as dominating different regions of Africa during the Pleistocene, isolated molars may on occasions have been assessed to species level on the basis of geography rather than morphology. The last morphologic evaluation of EFT elephants was conducted in the 1970s, and revisiting this issue with new specimens provides added insight into the evolution of elephants in Africa. Reevaluating morphological characteristics of EFT elephant molars, through qualitative and quantitative description and comparison with Middle Pleistocene E. recki recki, L. atlantica atlantica, and L. atlantica zulu molar morphology, corroborates assessment of EFT elephants as L. a. zulu. Two recently discovered, previously undescribed molars from EFT show that molars of L. a. zulu exhibit greater variation in enamel thickness, lamellar frequency, and occlusal surface morphology than previously reported. An update of the Pleistocene biogeography of Loxodonta and Elephas indicates that fossil remains of both are often found at the same localities in eastern Africa. Their rare co-occurrences in the north and south, however, suggest geographic separation of the two genera in at least some regions of Africa, which may have been based on habitat preference.

Morphology-based optical separation of subpopulations from a heterogeneous murine breast cancer cell line.

PubMed

Tamura, Masato; Sugiura, Shinji; Takagi, Toshiyuki; Satoh, Taku; Sumaru, Kimio; Kanamori, Toshiyuki; Okada, Tomoko; Matsui, Hirofumi

2017-01-01

Understanding tumor heterogeneity is an urgent and unmet need in cancer research. In this study, we used a morphology-based optical cell separation process to classify a heterogeneous cancer cell population into characteristic subpopulations. To classify the cell subpopulations, we assessed their morphology in hydrogel, a three-dimensional culture environment that induces morphological changes according to the characteristics of the cells (i.e., growth, migration, and invasion). We encapsulated the murine breast cancer cell line 4T1E, as a heterogeneous population that includes highly metastatic cells, in click-crosslinkable and photodegradable gelatin hydrogels, which we developed previously. We observed morphological changes within 3 days of encapsulating the cells in the hydrogel. We separated the 4T1E cell population into colony- and granular-type cells by optical separation, in which local UV-induced degradation of the photodegradable hydrogel around the target cells enabled us to collect those cells. The obtained colony- and granular-type cells were evaluated in vitro by using a spheroid assay and in vivo by means of a tumor growth and metastasis assay. The spheroid assay showed that the colony-type cells formed compact spheroids in 2 days, whereas the granular-type cells did not form spheroids. The tumor growth assay in mice revealed that the granular-type cells exhibited lower tumor growth and a different metastasis behavior compared with the colony-type cells. These results suggest that morphology-based optical cell separation is a useful technique to classify a heterogeneous cancer cell population according to its cellular characteristics.

Major Crop Species Show Differential Balance between Root Morphological and Physiological Responses to Variable Phosphorus Supply

PubMed Central

Lyu, Yang; Tang, Hongliang; Li, Haigang; Zhang, Fusuo; Rengel, Zed; Whalley, William R.; Shen, Jianbo

2016-01-01

The relationship between root morphological and physiological responses to variable P supply in different plant species is poorly understood. We compared root morphological and physiological responses to P supply in seven crop species (Zea mays, Triticum aestivum, Brassica napus, Lupinus albus, Glycine max, Vicia faba, Cicer arietinum) treated with or without 100 mg P kg-1 in two soils (acidic and calcareous). Phosphorus deficiency decreased root length more in fibrous root species (Zea mays, Triticum aestivum, Brassica napus) than legumes. Zea mays and Triticum aestivum had higher root/shoot biomass ratio and Brassica napus had higher specific root length compared to legumes, whereas legumes (except soybean) had higher carboxylate exudation than fibrous root species. Lupinus albus exhibited the highest P-acquisition efficiency due to high exudation of carboxylates and acid phosphatases. Lupinus albus and Cicer arietinum depended mostly on root exudation (i.e., physiological response) to enhance P acquisition, whereas Zea mays, Triticum aestivum and Brassica napus had higher root morphology dependence, with Glycine max and Vicia faba in between. Principal component analysis using six morphological and six physiological responses identified root size and diameter as the most important morphological traits, whereas important physiological responses included carboxylate exudation, and P-acquisition and P-utilization efficiency followed by rhizosphere soil pH and acid phosphatase activity. In conclusion, plant species can be grouped on the basis of their response to soil P being primarily via root architectural or exudation plasticity, suggesting a potential benefit of crop-specific root-trait-based management to cope with variable soil P supply in sustainable grain production. PMID:28066491

Biomolecular Mechanisms of Adaptive Reflectance and Related Biophotonic Systems in Molluscs

DTIC Science & Technology

2015-01-09

From Silica Skeletons of Sponges to Dynamically Tunable Photonics in Squid: Bio-inspired Materials Open New Horizons for Marine Biodiscovery...both types of reflective cells, the morphologies and dimensions of the dehydrated vesicles dictate that omnidirectional, broadband Mie scattering...family of synthetic polymeric thin films that exhibit electrically driven simultaneous changes in morphology and refractive index. The lesson we

Children's Use of Morphological Cues in Real-Time Event Representation

ERIC Educational Resources Information Center

Zhou, Peng; Ma, Weiyi

2018-01-01

The present study investigated whether and how fast young children can use information encoded in morphological markers during real-time event representation. Using the visual world paradigm, we tested 35 adults, 34 5-year-olds and 33 3-year-olds. The results showed that the adults, the 5-year-olds and the 3-year-olds all exhibited eye gaze…

Maxillary first molar with aberrant canal configuration: a report of 3 cases.

PubMed

Poorni, Saravanan; Kumar, Anil; Indira, Rajamani

2008-12-01

The prognosis for endodontic treatment in teeth exhibiting morphological aberrations is unfavorable if the clinician fails to recognize extra root canals. This report demonstrates 3 clinical cases of maxillary first molars that presented 2 canals in the palatal root merging at the apical third (Vertucci's type II canal morphology), a pattern that is rare and seldom encountered.

Lineages with long durations are old and morphologically average: an analysis using multiple datasets.

PubMed

Liow, Lee Hsiang

2007-04-01

Lineage persistence is as central to biology as evolutionary change. Important questions regarding persistence include: why do some lineages outlive their relatives, neither becoming extinct nor evolving into separate lineages? Do these long-duration lineages have distinctive ecological or morphological traits that correlate with their geologic durations and potentially aid their survival? In this paper, I test the hypothesis that lineages (species and higher taxa) with longer geologic durations have morphologies that are more average than expected by chance alone. I evaluate this hypothesis for both individual lineages with longer durations and groups of lineages with longer durations, using more than 60 published datasets of animals with adequate fossil records. Analyses presented here show that groups of lineages with longer durations fall empirically into one of three theoretically possible scenarios, namely: (1) the morphology of groups of longer duration lineages is closer to the grand average of their inclusive group, that is, their relative morphological distance is smaller than expected by chance alone, when compared with rarified samples of their shorter duration relatives (a negative group morpho-duration distribution); (2) the relative morphological distance of groups of longer duration lineages is no different from rarified samples of their shorter duration relatives (a null group morpho-duration distribution); and (3) the relative morphological distance of groups of longer duration lineages is greater than expected when compared with rarified samples of their shorter duration relatives (a positive group morpho-duration distribution). Datasets exhibiting negative group morpho-duration distributions predominate. However, lineages with higher ranks in the Linnean hierarchy demonstrate positive morpho-duration distributions more frequently. The relative morphological distance of individual longer duration lineages is no different from that of rarified samples of their shorter duration relatives (a null individual morpho-duration distribution) for the majority of datasets studied. Contrary to the common idea that very persistent lineages are special or unique in some significant way, both the results from analyses of long-duration lineages as groups and individuals show that they are morphologically average. Persistent lineages often arise early in a group's history, even though there is no prior expectation for this tendency in datasets of extinct groups. The implications of these results for diversification histories and niche preemption are discussed.

Structural characterization of ZnO thin films grown on various substrates by pulsed laser deposition

NASA Astrophysics Data System (ADS)

Novotný, M.; Čížek, J.; Kužel, R.; Bulíř, J.; Lančok, J.; Connolly, J.; McCarthy, E.; Krishnamurthy, S.; Mosnier, J.-P.; Anwand, W.; Brauer, G.

2012-06-01

ZnO thin films were grown by pulsed laser deposition on three different substrates: sapphire (0 0 0 1), MgO (1 0 0) and fused silica (FS). The structure and morphology of the films were characterized by x-ray diffraction and scanning electron microscopy and defect studies were carried out using slow positron implantation spectroscopy (SPIS). Films deposited on all substrates studied in this work exhibit the wurtzite ZnO structure and are characterized by an average crystallite size of 20-100 nm. However, strong differences in the microstructure of films deposited on various substrates were found. The ZnO films deposited on MgO and sapphire single-crystalline substrates exhibit local epitaxy, i.e. a well-defined relation between film crystallites and the substrate. Domains with different orientation relationships with the substrate were found in both films. On the other hand, the film deposited on the FS substrate exhibits fibre texture with random lateral orientation of crystallites. Extremely high compressive in-plane stress of σ ˜ 14 GPa was determined in the film deposited on the MgO substrate, while the film deposited on sapphire is virtually stress-free, and the film deposited on the FS substrate exhibits a tensile in-plane stress of σ ˜ 0.9 GPa. SPIS investigations revealed that the concentration of open-volume defects in the ZnO films is substantially higher than that in a bulk ZnO single crystal. Moreover, the ZnO films deposited on MgO and sapphire single-crystalline substrates exhibit a significantly higher density of defects than the film deposited on the amorphous FS substrate.

Detecting metal-poor gas accretion in the star-forming dwarf galaxies UM 461 and Mrk 600

NASA Astrophysics Data System (ADS)

Lagos, P.; Scott, T. C.; Nigoche-Netro, A.; Demarco, R.; Humphrey, A.; Papaderos, P.

2018-06-01

Using VIsible MultiObject Spectrograph (VIMOS)-integral field unit (IFU) observations, we study the interstellar medium (ISM) of two star-forming dwarf galaxies, UM 461 and Mrk 600. Our aim was to search for the existence of metallicity inhomogeneities that might arise from infall of nearly pristine gas feeding ongoing localized star formation. The IFU data allowed us to study the impact of external gas accretion on the chemical evolution as well as the ionized gas kinematics and morphologies of these galaxies. Both systems show signs of morphological distortions, including cometary-like morphologies. We analysed the spatial variation of 12 + log(O/H) abundances within both galaxies using the direct method (Te), the widely applied HII-CHI-mistry code, as well as by employing different standard calibrations. For UM 461, our results show that the ISM is fairly well mixed, at large scales; however, we find an off-centre and low-metallicity region with 12 + log(O/H) < 7.6 in the SW part of the brightest H II region, using the direct method. This result is consistent with the recent infall of a metal-poor H I cloud into the region now exhibiting the lowest metallicity, which also displays localized perturbed neutral and ionized gas kinematics. Mrk 600 in contrast, appears to be chemically homogeneous on both large and small scales. The intrinsic differences in the spatially resolved properties of the ISM in our analysed galaxies are consistent with these systems being at different evolutionary stages.

Rapid genetic diversification within dog breeds as evidenced by a case study on Schnauzers.

PubMed

Streitberger, K; Schweizer, M; Kropatsch, R; Dekomien, G; Distl, O; Fischer, M S; Epplen, J T; Hertwig, S T

2012-10-01

As a result of strong artificial selection, the domesticated dog has arguably become one of the most morphologically diverse vertebrate species, which is mirrored in the classification of around 400 different breeds. To test the influence of breeding history on the genetic structure and variability of today's dog breeds, we investigated 12 dog breeds using a set of 19 microsatellite markers from a total of 597 individuals with about 50 individuals analysed per breed. High genetic diversity was noted over all breeds, with the ancient Asian breeds (Akita, Chow Chow, Shar Pei) exhibiting the highest variability, as was indicated chiefly by an extraordinarily high number of rare and private alleles. Using a Bayesian clustering method, we detected significant genetic stratification within the closely related Schnauzer breeds. The individuals of these three recently differentiated breeds (Miniature, Standard and Giant Schnauzer) could not be assigned to a single cluster each. This hidden genetic structure was probably caused by assortative mating owing to breeders' preferences regarding coat colour types and the underlying practice of breeding in separate lineages. Such processes of strong artificial disruptive selection for different morphological traits in isolated and relatively small lineages can result in the rapid creation of new dog types and potentially new breeds and represent a unique opportunity to study the evolution of genetic and morphological differences in recently diverged populations. © 2011 The Authors, Animal Genetics © 2011 Stichting International Foundation for Animal Genetics.

Effects of Hatchery Rearing on the Structure and Function of Salmonid Mechanosensory Systems.

PubMed

Brown, Andrew D; Sisneros, Joseph A; Jurasin, Tyler; Coffin, Allison B

2016-01-01

This paper reviews recent studies on the effects of hatchery rearing on the auditory and lateral line systems of salmonid fishes. Major conclusions are that (1) hatchery-reared juveniles exhibit abnormal lateral line morphology (relative to wild-origin conspecifics), suggesting that the hatchery environment affects lateral line structure, perhaps due to differences in the hydrodynamic conditions of hatcheries versus natural rearing environments, and (2) hatchery-reared salmonids have a high proportion of abnormal otoliths, a condition associated with reduced auditory sensitivity and suggestive of inner ear dysfunction.

Morphology and electronic transport of polycrystalline pentacene thin-film transistors

NASA Astrophysics Data System (ADS)

Knipp, D.; Street, R. A.; Völkel, A. R.

2003-06-01

Temperature-dependent measurements of thin-film transistors were performed to gain insight in the electronic transport of polycrystalline pentacene. Devices were fabricated with plasma-enhanced chemical vapor deposited silicon nitride gate dielectrics. The influence of the dielectric roughness and the deposition temperature of the thermally evaporated pentacene films were studied. Although films on rougher gate dielectrics and films prepared at low deposition temperatures exhibit similar grain size, the electronic properties are different. Increasing the dielectric roughness reduces the free carrier mobility, while low substrate temperature leads to more and deeper hole traps.

Morphological response contributes to patient selection for rescue liver resection in chemotherapy patients with initially un-resectable colorectal liver metastasis.

PubMed

Suzuki, Koichi; Muto, Yuta; Ichida, Kosuke; Fukui, Taro; Takayama, Yuji; Kakizawa, Nao; Kato, Takaharu; Hasegawa, Fumi; Watanabe, Fumiaki; Kaneda, Yuji; Kikukawa, Rina; Saito, Masaaki; Tsujinaka, Shingo; Futsuhara, Kazushige; Takata, Osamu; Noda, Hiroshi; Miyakura, Yasuyuki; Kiyozaki, Hirokazu; Konishi, Fumio; Rikiyama, Toshiki

2017-08-01

Morphological response is considered an improved surrogate to the Response Evaluation Criteria in Solid Tumors (RECIST) model with regard to predicting the prognosis for patients with colorectal liver metastases. However, its use as a decision-making tool for surgical intervention has not been examined. The present study assessed the morphological response in 50 patients who underwent chemotherapy with or without bevacizumab for initially un-resectable colorectal liver metastases. Changes in tumor morphology between heterogeneous with uncertain borders and homogeneous with clear borders were defined as an optimal response (OR). Patients were also assessed as having an incomplete response (IR), and an absence of marked changes was assessed as no response (NR). No significant difference was observed in progression-free survival (PFS) between complete response/partial response (CR/PR) and stable disease/progressive disease (SD/PD), according to RECIST. By contrast, PFS for OR/IR patients was significantly improved compared with that for NR patients (13.2 vs. 8.7 months; P=0.0426). Exclusion of PD enhanced the difference in PFS between OR/IR and NR patients (15.1 vs. 9.3 months; P<0.0001), whereas no difference was observed between CR/PR and SD. The rate of OR and IR in patients treated with bevacizumab was 47.4% (9/19), but only 19.4% (6/31) for patients that were not administered bevacizumab. Comparison of the survival curves between OR/IR and NR patients revealed similar survival rates at 6 months after chemotherapy, but the groups exhibited different survival rates subsequent to this period of time. Patients showing OR/IR within 6 months appeared to be oncologically stable and could be considered as candidates for surgical intervention, including rescue liver resection. Comparing the pathological and morphological features of the tumor with representative optimal response, living tumor cells were revealed to be distributed within the area of vascular reconstruction induced by bevacizumab, resulting in a predictive value for prognosis in the patients treated with bevacizumab. The present findings provided the evidence for physicians to consider patients with previously un-resectable metastatic colorectal cancer as candidates for surgical treatment. Morphological response is a useful decision-making tool for evaluating these patients for rescue liver resection following chemotherapy.

Slow but tenacious: an analysis of running and gripping performance in chameleons.

PubMed

Herrel, Anthony; Tolley, Krystal A; Measey, G John; da Silva, Jessica M; Potgieter, Daniel F; Boller, Elodie; Boistel, Renaud; Vanhooydonck, Bieke

2013-03-15

Chameleons are highly specialized and mostly arboreal lizards characterized by a suite of derived characters. The grasping feet and tail are thought to be related to the arboreal lifestyle of chameleons, yet specializations for grasping are thought to exhibit a trade-off with running ability. Indeed, previous studies have demonstrated a trade-off between running and clinging performance, with faster species being poorer clingers. Here we investigate the presence of trade-offs by measuring running and grasping performance in four species of chameleon belonging to two different clades (Chamaeleo and Bradypodion). Within each clade we selected a largely terrestrial species and a more arboreal species to test whether morphology and performance are related to habitat use. Our results show that habitat drives the evolution of morphology and performance but that some of these effects are specific to each clade. Terrestrial species in both clades show poorer grasping performance than more arboreal species and have smaller hands. Moreover, hand size best predicts gripping performance, suggesting that habitat use drives the evolution of hand morphology through its effects on performance. Arboreal species also had longer tails and better tail gripping performance. No differences in sprint speed were observed between the two Chamaeleo species. Within Bradypodion, differences in sprint speed were significant after correcting for body size, yet the arboreal species were both better sprinters and had greater clinging strength. These results suggest that previously documented trade-offs may have been caused by differences between clades (i.e. a phylogenetic effect) rather than by design conflicts between running and gripping per se.

Bio-inspired synthesis of Y2O3: Eu3+ red nanophosphor for eco-friendly photocatalysis

NASA Astrophysics Data System (ADS)

Prasanna kumar, J. B.; Ramgopal, G.; Vidya, Y. S.; Anantharaju, K. S.; Daruka Prasad, B.; Sharma, S. C.; Prashantha, S. C.; Premkumar, H. B.; Nagabhushana, H.

2015-04-01

We report the synthesis of Y2O3: Eu3+ (1-11 mol%) nanoparticles (NPs) with different morphologies via eco-friendly, inexpensive and simple low temperature solution combustion method using Aloe Vera gel as fuel. The formation of different morphologies of Y2O3: Eu3+ NPs were characterized by PXRD, SEM, TEM, HRTEM, UV-Visible and PL techniques. The PXRD data and Rietveld analysis confirms the formation of single phase Y2O3 with cubic crystal structure. The influence of Eu3+ ion concentration on the morphology, UV-Visible absorption, PL emission and photocatalytic activity of Y2O3: Eu3+ nanostructures were investigated. Y2O3: Eu3+ NPs exhibit intense red emission with CIE chromaticity coordinates (0.50, 0.47) and correlated color temperature values at different excitation ranges from 1868 to 2600 K. The control of Eu3+ ion on Y2O3 matrix influences the photocatalytic decolorization of methylene blue (MB) as a model compound was evaluated under UVA light. Enhanced photocatalytic activity of conical shaped Y2O3: Eu3+ (1 mol%) was attributed to dopant concentration, crystallite size, textural properties and capability of reducing the electron-hole pair recombination. The trend of inhibitory effect in the presence of different radical scavengers followed the order SO42- > Cl- > C2H5OH > HCO3- > CO32-. These findings show great promise of Y2O3: Eu3+ NPs as a red phosphor in warm white LEDs as well as eco-friendly heterogeneous photocatalysis.

Solvothermal synthesis of hierarchical TiO2 nanostructures with tunable morphology and enhanced photocatalytic activity

NASA Astrophysics Data System (ADS)

Fan, Zhenghua; Meng, Fanming; Zhang, Miao; Wu, Zhenyu; Sun, Zhaoqi; Li, Aixia

2016-01-01

This paper presents controllable growth and photocatalytic activity of TiO2 hierarchical nanostructures by solvothermal method at different temperatures. It is revealed by scanning electron microscopy (SEM) and transmission electron microscopy (TEM) that the morphology of TiO2 can be effectively controlled as rose-like, chrysanthemum-like and sea-urchin-like only changing solvothermal temperature. BET surface area analysis confirms the presence of a mesoporous network in all the nanostructures, and shows high surface area at relatively high temperature. The photocatalytic activities of the photocatalysts are evaluated by the photodegradation of RhB under UV light irradiation. The TiO2 samples exhibit high activity on the photodegradation of RhB, which is higher than that of the commercial P25. The enhancement in photocatalytic performance can be attributed to the synergetic effect of the surface area, crystallinity, band gap and crystalline size.

Preparation of Shape-Controlled Graphene/Co3O4 Composites for Supercapacitors

NASA Astrophysics Data System (ADS)

Chen, Jun; Chen, Ningna; Feng, Xiaomiao; Hou, Wenhua

2016-09-01

Graphene/Co3O4 nanocomposites with different morphologies were fabricated by hydrothermal method. The morphology of nanocomposites was characterized by scanning electron microscopy. These composites could be used as the electrode materials for supercapacitors. The eletrochemical behavior of the composite was tested by cyclic voltammetry and galvanostatic charge-discharge measurements in 1.0 mol/L KOH solution. The results showed that the graphene/Co3O4 nanopetal composite exhibited excellent electrochemical performance. The specific capacitance value could reach up to 714 F/g at a scan rate of 2 mV/s. Besides, the capacitance of the graphene/Co3O4 nanopetal composite was 841 F/g at a current density of 0.1 A/g. After galvanostatic charge-discharge 1000 laps at the current density of 0.4 A/g, the specific capacitance could keep 96.7% of original capacitive value, demonstrating its good cycling stability.

Thickness effect of kenaf cellulose membrane on its morphological, physical and tensile properties

NASA Astrophysics Data System (ADS)

Hashim, Sharifah Nurul Ain Syed; Zakaria, Sarani; Jaafar, Sharifah Nabihah Syed; Chia, Chin Hua

2016-11-01

Dissolution of kenaf core cellulose was undergone in NaOH/Urea solvent and the cellulose solution was casted with three different thicknesses (0.04 mm, 0.06 mm and 0.07 mm) followed by coagulation in 5 % of H2SO4 to form regenerated cellulose membrane. The XRD results showed that the crystallinity index (CrI) of kenaf core cellulose membrane decreased after been regenerated into cellulose II. The surface morphology showed that the pores of the membrane became smaller as the thickness of cellulose membrane increased. The transparency tests demonstrated the thinner samples (0.04 mm) gave higher light transmittance than the thickest samples (0.07 mm). The kenaf core membrane with 0.07 mm thickness possessed highest tensile strength and breaking elongation at σ = 33.48 and ɛ = 8.03 relatively and also exhibited the largest pore size.

Molecular and Evolutionary History of Melanism in North American Gray Wolves

PubMed Central

Anderson, Tovi M.; vonHoldt, Bridgett M.; Candille, Sophie I.; Musiani, Marco; Greco, Claudia; Stahler, Daniel R.; Smith, Douglas W.; Padhukasahasram, Badri; Randi, Ettore; Leonard, Jennifer A.; Bustamante, Carlos D.; Ostrander, Elaine A.; Tang, Hua; Wayne, Robert K.; Barsh, Gregory S.

2010-01-01

Morphological diversity within closely related species is an essential aspect of evolution and adaptation. Mutations in the Melanocortin 1 receptor (Mc1r) gene contribute to pigmentary diversity in natural populations of fish, birds, and many mammals. However, melanism in the gray wolf, Canis lupus, is caused by a different melanocortin pathway component, the K locus, that encodes a beta-defensin protein that acts as an alternative ligand for Mc1r. We show that the melanistic K locus mutation in North American wolves derives from past hybridization with domestic dogs, has risen to high frequency in forested habitats, and exhibits a molecular signature of positive selection. The same mutation also causes melanism in the coyote, Canis latrans, and in Italian gray wolves, and hence our results demonstrate how traits selected in domesticated species can influence the morphological diversity of their wild relatives. PMID:19197024

Thin randomly aligned hierarchical carbon nanotube arrays as ultrablack metamaterials

NASA Astrophysics Data System (ADS)

De Nicola, Francesco; Hines, Peter; De Crescenzi, Maurizio; Motta, Nunzio

2017-07-01

Ultrablack metamaterials are artificial materials able to harvest all the incident light regardless of wavelength, angle, or polarization. Here, we show the ultrablack properties of randomly aligned hierarchical carbon nanotube arrays with thicknesses below 200 nm. The thin coatings are realized by solution processing and dry-transfer deposition on different substrates. The hierarchical surface morphology of the coatings is biomimetic and provides a large effective area that improves the film optical absorption. Also, such a morphology is responsible for the moth-eye effect, which leads to the omnidirectional and polarization-independent suppression of optical reflection. The films exhibit an emissivity up to 99.36% typical of an ideal black body, resulting in the thinnest ultrablack metamaterial ever reported. Such a material may be exploited for thermal, optical, and optoelectronic devices such as heat sinks, optical shields, solar cells, light and thermal sensors, and light-emitting diodes.

Signet ring cell melanocytic nevus: report of a case over trichilemmal cyst and review of the literature.

PubMed

Sabater Marco, Vicente; Escutia Muñoz, Begoña; Morera Faet, Arturo; Botella Estrada, Rafael

2012-02-01

Different melanocytic nevi have been reported as being associated with dermal cysts. Signet ring cell melanocytic nevus is a rare variant of melanocytic nevus characterized by cells with signet ring morphology within a common melanocytic nevus. This article describes an exceptional case of melanocytic nevus composed exclusively of signet ring cells over a trichilemmal cyst. Histologically, above the cyst, there was a small, symmetrical and sharply demarcated lesion showing a compound proliferation of small, round, monomorphous cells with signet ring morphology. Immunohistochemically, signet ring cells were negative for cytokeratin AE1/3, leukocyte common antigen, HMB-45, and CD34. Occasionally, isolated signet ring cells were positive for S-100 and melan A. Melanocytic nevus composed of signet ring cells should raise the differential diagnosis with other cutaneous tumors exhibiting signet ring cells. Previous cases of this entity reported in the literature are also reviewed.

Influence of the Additives and The pH On the Cobalt-Molybdenum (Co-Mo) Alloy Electrodeposited On n-TypeSilicon

NASA Astrophysics Data System (ADS)

Fekih, Z.; Ghellai, N.; Fortas, G.; Chiboub, N.; Sam, S.; Chabanne-sari, N. E.; Gabouze, N.

In this work, thin films of metal alloys (Co-Mo) have been electrodeposited onto silicon (Si) surface. The effects of two different additives (H3BO3 and Na2CO3) and the pH of the solution on the electrochemically deposited films (morphology, stochiometry…) have been investigated. The properties of the deposits were characterized by using X-Rays Diffraction (XRD), Scanning Electron Microscopy (SEM) and Energy Dispersive X-ray Spectroscopy (EDS). The results show that the morphology and the film composition depend on both the pH of the solution and the additives. The presence of boric acid favors the Mo deposition. Crack-free homogeneous deposits with a low percentage of molybdenum can be easily obtained from high pH bath. The deposits were shown to exhibits a good crystalline structure.

Water-Wisteria as an ideal plant to study heterophylly in higher aquatic plants.

PubMed

Li, Gaojie; Hu, Shiqi; Yang, Jingjing; Schultz, Elizabeth A; Clarke, Kurtis; Hou, Hongwei

2017-08-01

The semi-aquatic plant Water-Wisteria is suggested as a new model to study heterophylly due to its many advantages and typical leaf phenotypic plasticity in response to environmental factors and phytohormones. Water-Wisteria, Hygrophila difformis (Acanthaceae), is a fast growing semi-aquatic plant that exhibits a variety of leaf shapes, from simple leaves to highly branched compound leaves, depending on the environment. The phenomenon by which leaves change their morphology in response to environmental conditions is called heterophylly. In order to investigate the characteristics of heterophylly, we assessed the morphology and anatomy of Hygrophila difformis in different conditions. Subsequently, we verified that phytohormones and environmental factors can induce heterophylly and found that Hygrophila difformis is easily propagated vegetatively through either leaf cuttings or callus induction, and the callus can be easily transformed by Agrobacterium tumefaciens. These results suggested that Hygrophila difformis is a good model plant to study heterophylly in higher aquatic plants.

Response of Jupiter's auroras to conditions in the interplanetary medium as measured by the Hubble Space Telescope and Juno

NASA Astrophysics Data System (ADS)

Nichols, J. D.; Badman, S. V.; Bagenal, F.; Bolton, S. J.; Bonfond, B.; Bunce, E. J.; Clarke, J. T.; Connerney, J. E. P.; Cowley, S. W. H.; Ebert, R. W.; Fujimoto, M.; Gérard, J.-C.; Gladstone, G. R.; Grodent, D.; Kimura, T.; Kurth, W. S.; Mauk, B. H.; Murakami, G.; McComas, D. J.; Orton, G. S.; Radioti, A.; Stallard, T. S.; Tao, C.; Valek, P. W.; Wilson, R. J.; Yamazaki, A.; Yoshikawa, I.

2017-08-01

We present the first comparison of Jupiter's auroral morphology with an extended, continuous, and complete set of near-Jupiter interplanetary data, revealing the response of Jupiter's auroras to the interplanetary conditions. We show that for ˜1-3 days following compression region onset, the planet's main emission brightened. A duskside poleward region also brightened during compressions, as well as during shallow rarefaction conditions at the start of the program. The power emitted from the noon active region did not exhibit dependence on any interplanetary parameter, though the morphology typically differed between rarefactions and compressions. The auroras equatorward of the main emission brightened over ˜10 days following an interval of increased volcanic activity on Io. These results show that the dependence of Jupiter's magnetosphere and auroras on the interplanetary conditions are more diverse than previously thought.

Molecular and evolutionary history of melanism in North American gray wolves.

PubMed

Anderson, Tovi M; vonHoldt, Bridgett M; Candille, Sophie I; Musiani, Marco; Greco, Claudia; Stahler, Daniel R; Smith, Douglas W; Padhukasahasram, Badri; Randi, Ettore; Leonard, Jennifer A; Bustamante, Carlos D; Ostrander, Elaine A; Tang, Hua; Wayne, Robert K; Barsh, Gregory S

2009-03-06

Morphological diversity within closely related species is an essential aspect of evolution and adaptation. Mutations in the Melanocortin 1 receptor (Mc1r) gene contribute to pigmentary diversity in natural populations of fish, birds, and many mammals. However, melanism in the gray wolf, Canis lupus, is caused by a different melanocortin pathway component, the K locus, that encodes a beta-defensin protein that acts as an alternative ligand for Mc1r. We show that the melanistic K locus mutation in North American wolves derives from past hybridization with domestic dogs, has risen to high frequency in forested habitats, and exhibits a molecular signature of positive selection. The same mutation also causes melanism in the coyote, Canis latrans, and in Italian gray wolves, and hence our results demonstrate how traits selected in domesticated species can influence the morphological diversity of their wild relatives.

Altered cortical anatomical networks in temporal lobe epilepsy

NASA Astrophysics Data System (ADS)

Lv, Bin; He, Huiguang; Lu, Jingjing; Li, Wenjing; Dai, Dai; Li, Meng; Jin, Zhengyu

2011-03-01

Temporal lobe epilepsy (TLE) is one of the most common epilepsy syndromes with focal seizures generated in the left or right temporal lobes. With the magnetic resonance imaging (MRI), many evidences have demonstrated that the abnormalities in hippocampal volume and the distributed atrophies in cortical cortex. However, few studies have investigated if TLE patients have the alternation in the structural networks. In the present study, we used the cortical thickness to establish the morphological connectivity networks, and investigated the network properties using the graph theoretical methods. We found that all the morphological networks exhibited the small-world efficiency in left TLE, right TLE and normal groups. And the betweenness centrality analysis revealed that there were statistical inter-group differences in the right uncus region. Since the right uncus located at the right temporal lobe, these preliminary evidences may suggest that there are topological alternations of the cortical anatomical networks in TLE, especially for the right TLE.

Annealing induced reorientation of crystallites in Sn doped ZnO films

NASA Astrophysics Data System (ADS)

Ravichandran, K.; Vasanthi, M.; Thirumurugan, K.; Sakthivel, B.; Karthika, K.

2014-11-01

Tin doped ZnO thin films were prepared by employing a simplified spray pyrolysis technique using a perfume atomizer and subsequently annealed under different temperatures from 350 °C to 500 °C in steps of 50 °C. The structural, optical, electrical, photoluminescence and surface morphological properties of the as-deposited films were studied and compared with that of the annealed films. The X-ray diffraction studies showed that as-deposited film exhibits preferential orientation along the (0 0 2) plane and it changes in favour of (1 0 0) plane after annealing. The increase in crystallite size due to annealing is explained on the basis of Ostwald ripening effect. It is found that the optical transmittance and band gap increases with increase in annealing temperature. A slight decrease in resistivity caused by annealing is discussed in correlation with annealing induced defect modifications and surface morphology.

A fifth species of the genus Euparkerella (Griffths, 1959), the advertisement calls of E. robusta Izecksohn, 1988 and E. tridactyla Izecksohn, 1988, and a key for the Euparkerella species (Anura: Brachycephaloidea: Craugastoridae).

PubMed

Hepp, Fábio; Carvalho-E-Silva, Sergio P De; Carvalho-E-Silva, Ana M P Telles De; Folly, Manuella

2015-06-17

A new species of the anuran genus Euparkerella is described from a rainforest area in the state of Rio de Janeiro, southeastern Brazil. Morphologically, the species resembles E. brasiliensis and E. cochranae, but differs from them in acoustic features. Relative to its congeners, the new species is characterized by: (1) medium size; (2) slender body; (3) narrow head; (4) long Finger IV, Toes I and V; (5) tubercles of the hand and foot protuberant; (6) duration of advertisement call longer than three seconds; (7) pulse-section rate slower than two sections/second; and (8) exhibiting pulse clusters. The advertisement calls of E. robusta and E. tridactyla are described and a key based on morphological and acoustic characters is presented for species in the genus.

Karyological, morphological and phytochemical characteristics of medicinal plants Sophora flavescens Aiton grown from seeds collected at different localities.

PubMed

Lin, Tzu Che; Sung, Jih Min; Yeh, Mau Shing

2014-12-01

Dried roots of Sophora flavescens Aiton contain many phytochemicals that exhibit beneficial effects on human health. This study examined and compared the karyological, morphological and phytochemical characteristics of three S. flavescens populations collected from the Danda, Hualien and Yuli of Taiwan and a population collected from Gansu, China. Karyotypes of the four populations were similar, with a diploid number of 2n = 18. The Hualien population produced more roots but with less matrine and oxymatrine contents in its root tissue than others. However, only the root of Danda population had a measurable level of naringenin. The dried root of Yuli population had greater ferric reducing antioxidant power and trolox equivalent antioxidant capacity than that of the other populations. Thus, the collected S. flavescens populations, particularly the population collected from Danda, have the potential to be used in breeding programs.

Facile Synthesis of Nitrogen Doped Graphene Oxide from Graphite Flakes and Powders: A Comparison of Their Surface Chemistry.

PubMed

Yokwana, Kholiswa; Ray, Sekhar C; Khenfouch, Mohammad; Kuvarega, Alex T; Mamba, Bhekie B; Mhlanga, Sabelo D; Nxumalo, Edward N

2018-08-01

Nitrogen-doped graphene oxide (NGO) nanosheets were prepared via a facile one-pot modified Hummer's approach at low temperatures using graphite powder and flakes as starting materials in the presence of a nitrogen precursor. It was found that the morphology, structure, composition and surface chemistry of the NGO nanosheets depended on the nature of the graphite precursor used. GO nanosheets doped with nitrogen atoms exhibited a unique structure with few thin layers and wrinkled sheets, high porosity and structural defects. NGO sheets made from graphite powder (NGOp) exhibited excellent thermal stability and remarkably high surface area (up to 240.53 m2 ·g-1) compared to NGO sheets made from graphite flakes (NGOf) which degraded at low temperatures and had an average surface area of 24.70 m2 ·g-1. NGOf sheets had a size range of 850 to 2200 nm while NGOp sheets demonstrated obviously small sizes (460-1600 nm) even when exposed to different pH conditions. The NGO nanosheets exhibited negatively charged surfaces in a wide pH range (1 to 12) and were found to be stable above pH 6. In addition, graphite flakes were found to be more suitable for the production of NGO as they produced high N-doping levels (0.65 to 1.29 at.%) compared to graphite powders (0.30 to 0.35 at.%). This study further demonstrates that by adjusting the amount of N source in the host GO, one can tailor its thermal stability, surface morphology, surface chemistry and surface area.

Molecular Markers in Patients with Chronic Wounds to Guide Surgical Debridement

PubMed Central

Brem, Harold; Stojadinovic, Olivera; Diegelmann, Robert F; Entero, Hyacinth; Lee, Brian; Pastar, Irena; Golinko, Michael; Rosenberg, Harvey; Tomic-Canic, Marjana

2007-01-01

Chronic wounds, such as venous ulcers, are characterized by physiological impairments manifested by delays in healing, resulting in severe morbidity. Surgical debridement is routinely performed on chronic wounds because it stimulates healing. However, procedures are repeated many times on the same patient because, in contrast to tumor excision, there are no objective biological/molecular markers to guide the extent of debridement. To develop bioassays that can potentially guide surgical debridement, we assessed the pathogenesis of the patients’ wound tissue before and after wound debridement. We obtained biopsies from three patients at two locations, the nonhealing edge (prior to debridement) and the adjacent, nonulcerated skin of the venous ulcers (post debridement), and evaluated their histology, biological response to wounding (migration) and gene expression profile. We found that biopsies from the nonhealing edges exhibit distinct pathogenic morphology (hyperproliferative/hyperkeratotic epidermis; dermal fibrosis; increased procollagen synthesis). Fibroblasts deriving from this location exhibit impaired migration in comparison to the cells from adjacent nonulcerated biopsies, which exhibit normalization of morphology and normal migration capacity. The nonhealing edges have a specific, identifiable, and reproducible gene expression profile. The adjacent nonulcerated biopsies have their own distinctive reproducible gene expression profile, signifying that particular wound areas can be identified by gene expression profiling. We conclude that chronic ulcers contain distinct subpopulations of cells with different capacity to heal and that gene expression profiling can be utilized to identify them. In the future, molecular markers will be developed to identify the nonimpaired tissue, thereby making surgical debridement more accurate and more efficacious. PMID:17515955