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Sample records for phase function morphology

  1. Fabrication of phase and morphology controlled pure rutile and rutile/anatase TiO2 nanostructures in functional ionic liquid/water

    NASA Astrophysics Data System (ADS)

    Shahi, Satwant Kaur; Kaur, Navneet; Singh, Vasundhara

    2016-01-01

    In this paper, pure rutile and anatase-rutile TiO2 nanoparticles have been successfully synthesised via a green route by hydrolysis of titanium tetrachloride with room temperature acidic ionic liquid 3-methyl-1-(3-sulfonylpropyl) imidazolium trifluoromethanesulfonate [HO3S(CH2)3MIM][CF3SO3] in aqueous medium. The influence of pH of the solution by varying molar ratio of substrate and ionic liquid has been investigated in both sol⿿gel and hydrothermal synthesis of TiO2 with significant variation in phase, phase composition (ratio of rutile to anatase) and morphology as indicated by various structural analysis such as XRD, TEM, BET, Raman and UV⿿vis absorption spectroscopy. The results indicate formation of a bunch of aligned thin flaky nano-rods of TiO2 which look like nano-flowers with a crystal size of 3⿿5 nm by sol⿿gel method, while in case of hydrothermal method well-defined rutile solid nanorods of TiO2 were formed with variable length in the range of 120⿿170 nm and 20⿿24 nm in width. The photocatalytic activity of the prepared TiO2 samples has been determined by the photodegradation of methyl orange dye (20 ppm) under UV light. Best photocatalytic activity was exhibited by sample S-2 prepared via sol⿿gel method.

  2. Accurate sperm morphology assessment predicts sperm function.

    PubMed

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

    2012-05-01

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

  3. Functional innovations and morphological diversification in parrotfish.

    PubMed

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

    2010-10-01

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

  4. Pituitary function and morphology in Fabry disease.

    PubMed

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

    2015-11-01

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

  5. The functional morphology of hooding in cobras.

    PubMed

    Young, Bruce A; Kardong, Kenneth V

    2010-05-01

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

  6. Functional nasal morphology of chimaerid fishes.

    PubMed

    Howard, Lauren E; Holmes, William M; Ferrando, Sara; Maclaine, James S; Kelsh, Robert N; Ramsey, Andrew; Abel, Richard L; Cox, Jonathan P L

    2013-09-01

    Holocephalans (chimaeras) are a group of marine fishes comprising three families: the Callorhinchidae (callorhinchid fishes), the Rhinochimaeridae (rhinochimaerid fishes) and the Chimaeridae (chimaerid fishes). We have used X-ray microcomputed tomography and magnetic resonance imaging to characterise in detail the nasal anatomy of three species of chimaerid fishes: Chimaera monstrosa, C. phantasma and Hydrolagus colliei. We have shown that the nasal chamber of these three species is linked to the external environment by an incurrent channel and to the oral cavity by an excurrent channel via an oral groove. A protrusion of variable morphology is present on the medial wall of the incurrent channel in all three species, but is absent in members of the two other holocephalan families that we inspected. A third nasal channel, the lateral channel, functionally connects the incurrent nostril to the oral cavity, by-passing the nasal chamber. From anatomical reconstructions, we have proposed a model for the circulation of water, and therefore the transport of odorant, in the chimaerid nasal region. In this model, water could flow through the nasal region via the nasal chamber or the lateral channel. In either case, the direction of flow could be reversed. Circulation through the entire nasal region is likely to be driven primarily by the respiratory pump. We have identified several anatomical features that may segregate, distribute, facilitate and regulate flow in the nasal region and have considered the consequences of flow reversal. The non-sensory cilia lining the olfactory sensory channels appear to be mucus-propelling, suggesting that these cilia have a common protective role in cartilaginous fishes (sharks, rays and chimaeras). The nasal region of chimaerid fishes shows at least two adaptations to a benthic lifestyle, and suggests good olfactory sensitivity, with secondary folding enhancing the hypothetical flat sensory surface area by up to 70%.

  7. Effect of phase morphology on bulk strength for power-law materials

    NASA Astrophysics Data System (ADS)

    Gerbi, Christopher; Johnson, Scott E.; Cook, Alden; Vel, Senthil S.

    2015-01-01

    The strength of a polyphase aggregate comprising power-law materials is a function of the constitutive laws of the phases present, the arrangement of those phases and environmental conditions such as temperature. Primarily for geological applications, we consider the degree to which the arrangement of the phases has a significant influence on bulk strength. Calculations based on current single-mineral experimental data indicate that the absolute and relative strength differences between the upper and lower theoretical bounds vary widely with mineral pair, environmental conditions and strain rate. For example, at 850 °C, some pairs, such as plagioclase-clinopyroxene, are highly sensitive to phase morphology, whereas others, such as quartz-plagioclase, are not. Using a finite-element implementation of asymptotic expansion homogenization, we have calculated the bulk strength of natural and synthetic microstructures across macroscale strain gradients. We find that phase morphology does not change sufficiently in most cases to be the dominant factor in bulk strength variation. Thus on its own, phase morphology in an aggregate of power-law materials does not appear to be a major control on bulk strength under typical viscous geological conditions. However, phase morphology does affect microscale stress and strain rate patterns, which in turn can induce microscale variations in constitutive laws and diffusional pathways. These factors, including reactions and changing deformation mechanisms, are strongly influenced by phase morphology and do cause strength variation in rocks. As a result, any parametrization of rock strength needs to account for evolving modal mineralogy and deformation mechanisms in addition to morphological changes alone.

  8. Growth and Morphology of Phase Separating Supercritical Fluids

    NASA Technical Reports Server (NTRS)

    Hegseth, John; Beysens, Daniel; Perrot, Francoise; Nikolayev, Vadim; Garrabos, Yves

    1996-01-01

    The scientific objective is to study the relation between the morphology and the growth kinetics of domains during phase separation. We know from previous experiments performed near the critical point of pure fluids and binary liquids that there are two simple growth laws at late times. The 'fast' growth appears when the volumes of the phases are nearly equal and the droplet pattern is interconnected. In this case the size of the droplets grows linearly in time. The 'slow' growth appears when the pattern of droplets embedded in the majority phase is disconnected. In this case the size of the droplets increases in proportion to time to the power 1/3. The volume fraction of the minority phase is a good candidate to determine this change of behavior. All previous attempts to vary the volume fraction in a single experimental cell have failed because of the extreme experimental difficulties.

  9. Banded ion morphology - Main and recovery storm phases

    NASA Astrophysics Data System (ADS)

    Frahm, R. A.; Reiff, P. H.; Winningham, J. D.; Burch, J. L.

    The occurrence of bands in ion spectra obtained with the high-altitude and low-altitude plasma instruments on DE-1 and DE-2, respectively, during main and recovery storm phases from the period September 1981 - January 1982 is analyzed statistically. Typical spectra are shown; diagrams and graphs of storm morphology are provided; and two theoretical models (one based on time-of-flight effects and another based on convective dispersion) are discussed. It is found that bands occur more often in the main phase than in the recovery phase, and more often and at higher latitudes in the evening than before noon. From the stability of the bands and the dependence of energy on latitude it is inferred that convective dispersion plays a more important role than time-of-flight effects in the motion of heavy ions in the magnetosphere.

  10. Morphological modelling of three-phase microstructures of anode layers using SEM images.

    PubMed

    Abdallah, Bassam; Willot, François; Jeulin, Dominique

    2016-07-01

    A general method is proposed to model 3D microstructures representative of three-phases anode layers used in fuel cells. The models are based on SEM images of cells with varying morphologies. The materials are first characterized using three morphological measurements: (cross-)covariances, granulometry and linear erosion. They are measured on segmented SEM images, for each of the three phases. Second, a generic model for three-phases materials is proposed. The model is based on two independent underlying random sets which are otherwise arbitrary. The validity of this model is verified using the cross-covariance functions of the various phases. In a third step, several types of Boolean random sets and plurigaussian models are considered for the unknown underlying random sets. Overall, good agreement is found between the SEM images and three-phases models based on plurigaussian random sets, for all morphological measurements considered in the present work: covariances, granulometry and linear erosion. The spatial distribution and shapes of the phases produced by the plurigaussian model are visually very close to the real material. Furthermore, the proposed models require no numerical optimization and are straightforward to generate using the covariance functions measured on the SEM images.

  11. Nucleation, kinetics and morphology of displacive phase transformations in iron

    NASA Astrophysics Data System (ADS)

    Suiker, A. S. J.; Thijsse, B. J.

    2013-11-01

    An extensive, systematic molecular dynamics (MD) study is performed for analysing the nucleation, kinetics and morphology characteristics of thermally-induced, displacive phase transformations from face-centred cubic (fcc) to body-centred cubic (bcc) iron. At the atomic level these transformation characteristics are influenced by a number of factors, including (i) the appearance of free surfaces, (ii) the initial presence of fcc-bcc grain boundaries, (iii) the existence of point defects (i.e., atomic vacancies) near a grain boundary, (iv) the initial thermal velocities of the atoms, and (v) the specific interatomic potential used. Other MD studies that capture the overall transformation behaviour of iron well have often underestimated or ignored the influence by these factors on the transformation response, with the risk of putting the accuracy, generality and physical explanation of the MD results on loose grounds. The present research illustrates the relative contribution of each of the above factors by means of a detailed comparison study for three different interatomic potentials. The accuracy of the interatomic potentials is established by validating for the fcc and bcc phases the calculated elastic moduli, cohesive energy, vacancy formation energy and interfacial energy against experimental and ab initio data reported in the literature. The importance of calibrating material data of both the stable bcc phase and the metastable fcc phase - instead of the stable bcc phase only - is demonstrated. The numerical results call for general caution when interpreting phenomena that start close to instability points and therefore are sensitive to small disturbances; a large spread in the overall transformation time is found under different initial thermal velocities, interfacial lattice incoherence, boundary conditions (free vs. periodic), and interatomic potentials, where for completely transformed atomic systems the discrepancy between the maximum and minimum

  12. Prdm8 regulates the morphological transition at multipolar phase during neocortical development.

    PubMed

    Inoue, Mayuko; Kuroda, Takao; Honda, Aya; Komabayashi-Suzuki, Mariko; Komai, Tae; Shinkai, Yoichi; Mizutani, Ken-ichi

    2014-01-01

    Here, we found that the PR domain protein Prdm8 serves as a key regulator of the length of the multipolar phase by controlling the timing of morphological transition. We used a mouse line with expression of Prdm8-mVenus reporter and found that Prdm8 is predominantly expressed in the middle and upper intermediate zone during both the late and terminal multipolar phases. Prdm8 expression was almost coincident with Unc5D expression, a marker for the late multipolar phase, although the expression of Unc5D was found to be gradually down-regulated to the point at which mVenus expression was gradually up-regulated. This expression pattern suggests the possible involvement of Prdm8 in the control of the late and terminal multipolar phases, which controls the timing for morphological transition. To test this hypothesis, we performed gain- and loss-of-function analysis of neocortical development by using in utero electroporation. We found that the knockdown of Prdm8 results in premature change from multipolar to bipolar morphology, whereas the overexpression of Prdm8 maintained the multipolar morphology. Additionally, the postnatal analysis showed that the Prdm8 knockdown stimulated the number of early born neurons, and differentiated neurons located more deeply in the neocortex, however, majority of those cells could not acquire molecular features consistent with laminar location. Furthermore, we found the candidate genes that were predominantly utilized in both the late and terminal multipolar phases, and these candidate genes included those encoding for guidance molecules. In addition, we also found that the expression level of these guidance molecules was inhibited by the introduction of the Prdm8 expression vector. These results indicate that the Prdm8-mediated regulation of morphological changes that normally occur during the late and terminal multipolar phases plays an important role in neocortical development.

  13. Coarse-grained molecular dynamics simulation of binary charged lipid membranes: Phase separation and morphological dynamics

    NASA Astrophysics Data System (ADS)

    Ito, Hiroaki; Higuchi, Yuji; Shimokawa, Naofumi

    2016-10-01

    Biomembranes, which are mainly composed of neutral and charged lipids, exhibit a large variety of functional structures and dynamics. Here, we report a coarse-grained molecular dynamics (MD) simulation of the phase separation and morphological dynamics in charged lipid bilayer vesicles. The screened long-range electrostatic repulsion among charged head groups delays or inhibits the lateral phase separation in charged vesicles compared with neutral vesicles, suggesting the transition of the phase-separation mechanism from spinodal decomposition to nucleation or homogeneous dispersion. Moreover, the electrostatic repulsion causes morphological changes, such as pore formation, and further transformations into disk, string, and bicelle structures, which are spatiotemporally coupled to the lateral segregation of charged lipids. Based on our coarse-grained MD simulation, we propose a plausible mechanism of pore formation at the molecular level. The pore formation in a charged-lipid-rich domain is initiated by the prior disturbance of the local molecular orientation in the domain.

  14. Functional morphology of the Neandertal scapular glenoid fossa.

    PubMed

    Macias, Marisa E; Churchill, Steven E

    2015-01-01

    Neandertals and Homo sapiens are known to differ in scapular glenoid fossa morphology. Functional explanations may be appropriate for certain aspects of glenoid fossa morphology; however, other factors--e.g., allometry, evolutionary development--must be addressed before functional morphology is considered. Using three-dimensional geometric morphometrics, shape of the scapular glenoid fossa was compared among Neandertals, early and recent modern humans, chimpanzees, orangutans, Australopithecus afarensis, and Au. sediba. Permutation analysis revealed that side, sex, and lifestyle did not correlate with shape. Of the features we found to differ between groups, anterior glenoid rim morphology and fossa curvature did not correlate with the aforementioned shape variables; thus, a functional explanation is appropriate for these components of glenoid fossa shape. Shared morphology among recent humans and chimpanzees (to the exclusion of Neandertals and orangutans) suggests independent forces contributing to these morphological configurations. Potential explanations include adaptations to habitual behavior and locomotor adaptations in the scapulae of recent humans and chimpanzees; these explanations are supported by clinical and experimental literature. The absence of these morphological features in Neandertals may support the lack of these selective forces on their scapular glenoid fossa morphology.

  15. Phase behavior, morphology, and polymorphism of surfactant systems

    NASA Astrophysics Data System (ADS)

    Liang, Jingmei

    Surfactants are amphiphilic molecules. They spontaneously form various microstructures in water to accommodate the hydrophilic-hydrophobic interactions. Soaps are the oldest kind of man-made surfactants that are commonly used as washing and cleaning agents. In spite of the long history of soap research, many aspects of soaps in nonaqueous solvents remain unclear. Unlike the aqueous soap systems, which have been studied extensively, investigations of nonaqueous, polar soap systems are rather limited. Motivated by the applications of nonaqueous, polar solvents in soap products, we investigated sodium stearate (NaSt)/water/propylene glycol (PG) systems. The effects of gradual substitution of PG for H 2O on the phase behavior, morphology and crystalline structure of NaSt systems were studied by a combination of characterization techniques. The techniques include direct visual observation, differential scanning calorimetry, wide-angle and small angle x-ray scattering, light and cryo-electron microscopy, and solid-state nuclear magnetic resonance. Anhydrous NaSt forms layered crystalline structures at 25°C. With increasing temperature, a distorted hexagonal phase and a hexagonal liquid crystalline phase form. Compared with aqueous soap systems, the regions of liquid crystalline phases in the phase diagrams are reduced as PG replaces or gradually substitutes for H2O. Fibrous and plate-like NaSt crystallites were investigated in the NaSt/PG/H 2O system containing 1-5 wt% NaSt. Despite of the morphological difference, NaSt fibers and platelets share the same layered crystalline structure at the molecular level. NaSt fibers consist of stacked thin ribbons of NaSt bilayers. NaSt platelets exhibit large basal planes {001} surrounded by other faster-growing lateral planes. Two lamellar crystalline structures, alpha-NaSt and beta-NaSt, which formed in the NaSt/PG/H2O system with 10 wt% NaSt, were characterized on the atomic, molecular and microscopic levels. In a PG

  16. Morphologically and Functionally Distinct Lipid Droplet Subpopulations

    PubMed Central

    Zhang, Shuyan; Wang, Yang; Cui, Liujuan; Deng, Yaqin; Xu, Shimeng; Yu, Jinhai; Cichello, Simon; Serrero, Ginette; Ying, Yunshu; Liu, Pingsheng

    2016-01-01

    Lipid droplet (LD), a multi-functional organelle, is often found to associate with other cellular membranous structures and vary in size in a given cell, which may be related to their functional diversity. Here we established a method to separate LD subpopulations from isolated CHO K2 LDs into three different size categories. The subpopulation with smallest LDs was nearly free of ER and other membranous structures while those with larger LDs contained intact ER. These distinct subpopulations of LDs differed in their protein composition and ability to recruit proteins. This method was also applicable to LDs obtained from other sources, such as Huh7 cells, mouse liver and brown adipose tissue, et al. We developed an in vitro assay requiring only isolated LDs, Coenzyme A, and ATP to drive lipid synthesis. The LD subpopulation nearly depleted of ER was able to incorporate fatty acids into triacylglycerol and phospholipids. Together, our data demonstrate that LDs in a given cell are heterogeneous in size and function, and suggest that LDs are one of cellular lipid synthetic organelles. PMID:27386790

  17. Morphology and crystal phase evolution of GeO 2 in liquid phase deposition process

    NASA Astrophysics Data System (ADS)

    Jing, Chengbin; Sun, Wei; Wang, Wei; Li, Yi; Chu, Junhao

    2012-01-01

    Morphology and crystal phase evolution of GeO 2 in liquid phase deposition (LPD) process is investigated. Rod-like solid phases precipitate out of solution ahead of truncated cube-like phases. SEM, XRD and TEM analyses reveal that the two sorts of solid phases are tetragonal GeO 2 and hexagonal GeO 2, respectively. The tetragonal GeO 2 phases start to experience a re-dissolving process as soon as the hexagonal phases come into being. The prior precipitation of the rod-like phase arises from a relatively low solute saturation of tetragonal GeO 2. Fast growth of a tetragonal GeO 2 phase along [111] direction leads to development of a rod-like shape. The re-dissolving phenomenon does not agree with the classic growth kinetics of crystals but is strongly favored by our calculations based on thermodynamics. The GeO 2 solutes are released in a fluctuant way by germanate ions, which promotes the occurrence of the re-dissolution phenomenon. The current researches open a door for room-temperature LPD growth of not only the hexagonal GeO 2 particles and film but also the one-dimensional tetragonal GeO 2 product.

  18. cAMP initiates early phase neuron-like morphology changes and late phase neural differentiation in mesenchymal stem cells.

    PubMed

    Zhang, Linxia; Seitz, Linsey C; Abramczyk, Amy M; Liu, Li; Chan, Christina

    2011-03-01

    The intracellular second messenger cAMP is frequently used in induction media to induce mesenchymal stem cells (MSCs) into neural lineage cells. To date, an understanding of the role cAMP exerts on MSCs and whether cAMP can induce MSCs into functional neurons is still lacking. We found cAMP initiated neuron-like morphology changes early and neural differentiation much later. The early phase changes in morphology were due to cell shrinkage, which subsequently rendered some cells apoptotic. While the morphology changes occurred prior to the expression of neural markers, it is not required for neural marker expression and the two processes are differentially regulated downstream of cAMP-activated protein kinase A. cAMP enabled MSCs to gain neural marker expressions with neuronal function, such as, calcium rise in response to neuronal activators, dopamine, glutamate, and potassium chloride. However, only some of the cells induced by cAMP responded to the three neuronal activators and further lack the neuronal morphology, suggesting that although cAMP is able to direct MSCs towards neural differentiation, they do not achieve terminal differentiation.

  19. cAMP initiates early phase neuron-like morphology changes and late phase neural differentiation in mesenchymal stem cells

    PubMed Central

    Zhang, Linxia; Seitz, Linsey C.; Abramczyk, Amy M.; Liu, Li

    2010-01-01

    The intracellular second messenger cAMP is frequently used in induction media to induce mesenchymal stem cells (MSCs) into neural lineage cells. To date, an understanding of the role cAMP exerts on MSCs and whether cAMP can induce MSCs into functional neurons is still lacking. We found cAMP initiated neuron-like morphology changes early and neural differentiation much later. The early phase changes in morphology were due to cell shrinkage, which subsequently rendered some cells apoptotic. While the morphology changes occurred prior to the expression of neural markers, it is not required for neural marker expression and the two processes are differentially regulated downstream of cAMP-activated protein kinase A. cAMP enabled MSCs to gain neural marker expressions with neuronal function, such as, calcium rise in response to neuronal activators, dopamine, glutamate, and potassium chloride. However, only some of the cells induced by cAMP responded to the three neuronal activators and further lack the neuronal morphology, suggesting that although cAMP is able to direct MSCs towards neural differentiation, they do not achieve terminal differentiation. PMID:20725762

  20. Diabetic rat testes: morphological and functional alterations.

    PubMed

    Ricci, G; Catizone, A; Esposito, R; Pisanti, F A; Vietri, M T; Galdieri, M

    2009-12-01

    Reproductive dysfunction is a consequence of diabetes, but the underlying mechanisms are poorly understood. This study investigated the histological and molecular alterations in the testes of rats injected with streptozotocin at prepuperal (SPI rats) and adult age (SAI rats) to understand whether diabetes affects testicular tissue with different severity depending on the age in which this pathological condition starts. The testes of diabetic animals showed frequent abnormal histology, and seminiferous epithelium cytoarchitecture appeared altered as well as the occludin distribution pattern. The early occurrence of diabetes increased the percentage of animals with high number of damaged tubules. The interstitial compartment of the testes was clearly hypertrophic in several portions of the organs both in SPI and SAI rats. Interestingly, fully developed Leydig cells were present in all the treated animals although abnormally distributed. Besides the above-described damages, we found a similar decrease in plasma testosterone levels both in SPI and SAI rats. Oxidative stress (OS) is involved in the pathogenesis of various diabetic complications, and in our experimental models we found that manganese superoxide dismutase was reduced in diabetic animals. We conclude that in STZ-induced diabetes, the altered spermatogenesis, more severe in SPI animals, is possibly due to the effect of OS on Leydig cell function which could cause the testosterone decrease responsible for the alterations found in the seminiferous epithelium of diabetic animals.

  1. Banded ion morphology: Main and recovery storm phases

    NASA Astrophysics Data System (ADS)

    Frahm, R. A.; Reiff, P. H.; Winningham, J. D.; Burch, J. L.

    Ion bands appear in a spectrogram display as a continuous line of enhanced ion energy flux, whose median energy increases as the satellite travels poleward in the low and mid-altitude magnetosphere. These ion bands occur with highest energy flux at zero degrees pitch angle. Ion bands similar to those described previously have been investigated using data from the Low Altitude Plasma Instrument (LAPI) and High Altitude Plasma Instrument (HAPI) flown on the Dynamics Explorer (DE) satellites. The purpose of this paper is to present the results of a statistical study of band occurrence and to present and describe the current models for band formation. The morphology of ion bands has been examined for main and recovery storm phases covering the period from September 1981 to December 1981. Bands are more likely to be seen during the main phase of magnetic storms than during recovery phase. Bands are more prevalent in the evening sector and occur at higher invariant latitudes (˜5°) than those in the pre-noon sector. Two current models have been proposed to describe bands or band-like signatures in ion spectrograms. The first is a time-of-flight effect as in the bouncing ion clusters (seen at geosynchronous orbit). The second is convective dispersion, where ions from the opposite hemisphere's ionosphere experience significant motion perpendicular to magnetic field lines and become dispersed in latitude as they travel parallel to a magnetic field line. The data tend to favor convective dispersion, although time-of-flight effects can also be seen.

  2. Morphological filters for functional assessment of roundness profiles

    NASA Astrophysics Data System (ADS)

    Lou, Shan; Jiang, Xiangqian; Scott, Paul J.

    2014-06-01

    Filtration techniques are useful tools for analysing roundness profiles. The 2RC filter and Gaussian filter are commonly used to assess peripheral undulations of the roundness data. However they cannot do every aspect of functional prediction. Morphological filters are employed to characterize roundness profiles for functional assessment. Traditional computation methods for morphological filters are limited to planar surfaces and unable to be extended to roundness measurement. A novel method based on alpha shape theory is developed to break up the confinement. The morphological closing and opening envelopes are obtained by rolling a disk upon the roundness profile from the air and material side of the component respectively. They can be used to identify significant peaks and valleys on the profile respectively, which is vital to the functional performance of components, especially contact phenomenon. A case study is presented where various options of morphological filters and reference circles are applied to a roundness profile, delivering different functional meanings. An in-depth comparison of morphological filters and the Gaussian filter is followed to derive their pros and cons.

  3. Effects of Morphology and Geometry of Inclusions on Two-Point Correlation Statistics in Two Phase Composites

    SciTech Connect

    Tabei, Ali; Ahzi, Said; Li, Dongsheng; Lavender, Curt A.; Garmestani, Hamid

    2014-01-06

    A spectral form of the two-point correlation functions for two-phase composites is presented and the effects of secondary phase morphology, geometry and volume fraction on the coefficients of the corresponding series are studied. Initially, a principal component analysis is performed on the coefficients of the series and then, the effects of different morphological and geometrical parameters of the second phase inclusions on two-point correlation functions are examined. A direct linkage between the principal components of the coefficients with the morphological features (inclusion shape, aspect ratio and size) is established and the influence of preferred orientation of the anisotropic inclusions is also investigated. Finally a composite hull is constructed using the principal components of the coefficients in a three-dimensional space, which helps in determining the interrelation of properties and microstructures of any composite containing these types of inclusions.

  4. Uncoupled Leftward Asymmetries for Planum Morphology and Functional Language Processing

    ERIC Educational Resources Information Center

    Eckert, Mark A.; Leonard, Christiana M.; Possing, Edward T.; Binder, Jeffrey R.

    2006-01-01

    Explanations for left hemisphere language laterality have often focused on hemispheric structural asymmetry of the planum temporale. We examined the association between an index of language laterality and brain morphology in 99 normal adults whose degree of laterality was established using a functional MRI single-word comprehension task. The index…

  5. Biomimetic robotics should be based on functional morphology

    PubMed Central

    Witte, Hartmut; Hoffmann, Helge; Hackert, Rémi; Schilling, Cornelius; Fischer, Martin S; Preuschoft, Holger

    2004-01-01

    Due to technological improvements made during the last decade, bipedal robots today present a surprisingly high level of humanoid skill. Autonomy, with respect to the processing of information, is realized to a relatively high degree. What is mainly lacking in robotics, moving from purely anthropomorphic robots to ‘anthropofunctional’ machines, is energetic autonomy. In a previously published analysis, we showed that closer attention to the functional morphology of human walking could give robotic engineers the experiences of an at least 6 Myr beta test period on minimization of power requirements for biped locomotion. From our point of view, there are two main features that facilitate sustained walking in modern humans. The first main feature is the existence of ‘energetically optimal velocities’ provided by the systematic use of various resonance mechanisms: (a) suspended pendula (involving arms as well as legs in the swing phase of the gait cycle) and matching of the pendular length of the upper and lower limbs; (b) inverted pendula (involving the legs in the stance phase), driven by torsional springs around the ankle joints; and (c) torsional springs in the trunk. The second main feature is compensation for undesirable torques induced by the inertial properties of the swinging extremities: (a) mass distribution in the trunk characterized by maximized mass moments of inertia; (b) lever arms of joint forces at the hip and shoulder, which are inversely proportional to their amplitude; and (c) twisting of the trunk, especially torsion. Our qualitative conclusions are three-fold. (1) Human walking is an interplay between masses, gravity and elasticity, which is modulated by musculature. Rigid body mechanics is insufficient to describe human walking. Thus anthropomorphic robots completely following the rules of rigid body mechanics cannot be functionally humanoid. (2) Humans are vertebrates. Thus, anthropomorphic robots that do not use the trunk for purposes

  6. Atypical neoglottis after supracricoid laryngectomy: a morphological and functional analysis.

    PubMed

    Alicandri-Ciufelli, Matteo; Piccinini, Alessia; Bergamini, Giuseppe; Ruberto, Marco; Ghidini, Angelo; Marchioni, Daniele; Presutti, Livio

    2011-07-01

    The objective of this study was to analyze atypical neoglottis after supracricoid subtotal laryngectomy (SSL) from a morphological and functional point-of-view using retrospective case series reviewin a Tertiary university referral center setting. From May 2003 until January 2010, 106 patients underwent SSL (CHEP, CHP, THEP, THP) for laryngeal cancer, in the Otolaryngology Department of the University Hospital of Modena. We performed a retrospective analysis of recorded videos in our database of patients who underwent SSL. Patients with atypical neoglottis were included in the study. Six patients with atypical neoglottis were identified and morphologically evaluated. The functional outcomes were collected and analyzed. Atypical neoglottis may form after SSL, in particular in the case of CHEP. In most cases, these atypical conformations are due to anomalous positioning of the epiglottis, or involvement of the lateral pharyngeal wall in the sphincteric and vibratory function of the neoglottis. Atypical neoglottis formation seems to guarantee adequate functional outcomes in terms of vocal and swallowing performance.

  7. Breathing and locomotion: comparative anatomy, morphology and function.

    PubMed

    Klein, Wilfried; Codd, Jonathan R

    2010-08-31

    Using specialized respiratory structures such as gills, lungs and or a tracheal system, animals take up oxygen and release carbon dioxide. The efficiency of gas exchange, however, may be constrained by the morphology of the respiratory organ itself as well as by other aspects of an animal's physiology such as feeding, circulation or locomotion. Herein we discuss some aspects of the functional link between the respiratory and locomotor systems, such as gill morphology of sharks as a factor limiting maximum aerobic scope, respiratory constraints among legless lizards, lung morphology of testudines, trade-offs between locomotion and respiration among birds, reconstruction of the respiratory system of sauropods, respiration of mice during locomotion as well as some aspects of gas exchange among insects. Data covering such a broad spectrum of interactions between the locomotor and respiratory systems shall allow us to place breathing and locomotion into a wider context of evolution of oxygen.

  8. Interconnected Network Motifs Control Podocyte Morphology and Kidney Function

    PubMed Central

    Azeloglu, Evren U.; Hardy, Simon V.; Eungdamrong, Narat John; Chen, Yibang; Jayaraman, Gomathi; Chuang, Peter Y.; Fang, Wei; Xiong, Huabao; Neves, Susana R.; Jain, Mohit R.; Li, Hong; Ma’ayan, Avi; Gordon, Ronald E.; He, John Cijiang; Iyengar, Ravi

    2014-01-01

    Podocytes are kidney cells with specialized morphology that is required for glomerular filtration. Diseases, such as diabetes, or drug exposure that causes disruption of the podocyte foot process morphology results in kidney pathophysiology. Proteomic analysis of glomeruli isolated from rats with puromycin-induced kidney disease and control rats indicated that protein kinase A (PKA), which is activated by adenosine 3′,5′-monophosphate (cAMP), is a key regulator of podocyte morphology and function. In podocytes, cAMP signaling activates cAMP response element–binding protein (CREB) to enhance expression of the gene encoding a differentiation marker, synaptopodin, a protein that associates with actin and promotes its bundling. We constructed and experimentally verified a β-adrenergic receptor–driven network with multiple feedback and feedforward motifs that controls CREB activity. To determine how the motifs interacted to regulate gene expression, we mapped multicompartment dynamical models, including information about protein subcellular localization, onto the network topology using Petri net formalisms. These computational analyses indicated that the juxtaposition of multiple feedback and feedforward motifs enabled the prolonged CREB activation necessary for synaptopodin expression and actin bundling. Drug-induced modulation of these motifs in diseased rats led to recovery of normal morphology and physiological function in vivo. Thus, analysis of regulatory motifs using network dynamics can provide insights into pathophysiology that enable predictions for drug intervention strategies to treat kidney disease. PMID:24497609

  9. Morphology and behaviour: functional links in development and evolution

    PubMed Central

    Bertossa, Rinaldo C.

    2011-01-01

    Development and evolution of animal behaviour and morphology are frequently addressed independently, as reflected in the dichotomy of disciplines dedicated to their study distinguishing object of study (morphology versus behaviour) and perspective (ultimate versus proximate). Although traits are known to develop and evolve semi-independently, they are matched together in development and evolution to produce a unique functional phenotype. Here I highlight similarities shared by both traits, such as the decisive role played by the environment for their ontogeny. Considering the widespread developmental and functional entanglement between both traits, many cases of adaptive evolution are better understood when proximate and ultimate explanations are integrated. A field integrating these perspectives is evolutionary developmental biology (evo-devo), which studies the developmental basis of phenotypic diversity. Ultimate aspects in evo-devo studies—which have mostly focused on morphological traits—could become more apparent when behaviour, ‘the integrator of form and function’, is integrated into the same framework of analysis. Integrating a trait such as behaviour at a different level in the biological hierarchy will help to better understand not only how behavioural diversity is produced, but also how levels are connected to produce functional phenotypes and how these evolve. A possible framework to accommodate and compare form and function at different levels of the biological hierarchy is outlined. At the end, some methodological issues are discussed. PMID:21690124

  10. THE SKIN | Functional morphology of the integumentary system in fishes

    USGS Publications Warehouse

    Elliott, D.G.; Farrell, Anthony P.

    2011-01-01

    The integument that covers the outer surface of a fish’s body and fins is a multifunctional organ, with morphological features highly adapted to carry out these functions. The integument consists of two layers. The outer layer, the epidermis, is essentially cellular in structure, comprised of a multilayered epithelium that usually includes specialized cells. The inner layer, the dermis, is primarily a fibrous structure with relatively few cells, although it may contain scales, nerves, blood vessels, adipose tissue, and pigment cells.

  11. Kif5 regulates mitochondrial movement, morphology, function and neuronal survival.

    PubMed

    Iworima, Diepiriye G; Pasqualotto, Bryce A; Rintoul, Gordon L

    2016-04-01

    Due to the unique architecture of neurons, trafficking of mitochondria throughout processes to regions of high energetic demand is critical to sustain neuronal health. It has been suggested that compromised mitochondrial trafficking may play a role in neurodegenerative diseases. We evaluated the consequences of disrupted kif5c-mediated mitochondrial trafficking on mitochondrial form and function in primary rat cortical neurons. Morphological changes in mitochondria appeared to be due to remodelling, a phenomenon distinct from mitochondrial fission, which resulted in punctate-shaped mitochondria. We also demonstrated that neurons displaying punctate mitochondria exhibited relatively decreased ROS and increased cellular ATP levels using ROS-sensitive GFP and ATP FRET probes, respectively. Somewhat unexpectedly, neurons overexpressing the dominant negative form of kif5c exhibited enhanced survival following excitotoxicity, suggesting that the impairment of mitochondrial trafficking conferred some form of neuroprotection. However, when neurons were exposed to H2O2, disruption of kif5c exacerbated cell death indicating that the effect on cell viability was dependent on the mode of toxicity. Our results suggest a novel role of kif5c. In addition to mediating mitochondrial transport, kif5c plays a role in the mechanism of regulating mitochondrial morphology. Our results also suggest that kif5c mediated mitochondrial dynamics may play an important role in regulating mitochondrial function and in turn cellular health. Moreover, our studies demonstrate an interesting interplay between the regulation of mitochondrial motility and morphology.

  12. Ultrasensitive Phase-Resolved Imaging of Cellular Morphology and Dynamics

    NASA Astrophysics Data System (ADS)

    Choma, Michael A.; Ellerbee, Audrey; Izatt, Joseph A.

    Microscopy is an important imaging tool in modern clinical medicine and basic biomedical research. The retrieval of phase information from microscopic samples has a long history initiated by the development of the phase contrast microscope. This technique exploits the fact that optically thin samples such as cells diffract light secondary to local variations in optical index. Phase contrast microscopy has had an immeasurable impact by allowing the user to qualitatively visualize small, subcellular variations in optical index. Quantitative phase microscopy seeks to build upon the principles of phase contrast microscopy to extract quantitative measures relating to optical index, birefringence, motion, and flow. In addition to highlighting subcellular detail in unstained cells, quantitative phase techniques can measure picometer-scale cell motions, small changes in cell index, and even cytoplasmic flow. Because of its sensitivity to phase and its ability to reliably quantify and track changes in coherent wavefronts, interferometry has recently gained momentum as a technique for the implementation of quantitative phase microscopy. This chapter reviews interferometric phase contrast microscopy techniques, with an emphasis on broadband interferometric techniques which exploit the principles of OCT. Both the underlying theory as well biological applications are discussed. Although this chapter gives particular focus to biologically relevant applications, the methods are readily extendable for other, nonbiological applications.

  13. The effect of morphology and confinement on the high-pressure phase transition in ZnO nanostructure

    SciTech Connect

    Kotmool, Komsilp; Bovornratanaraks, Thiti; Chakraborty, Sudip; Ahuja, Rajeev

    2015-03-21

    The transition pressure (P{sub t}) of the B4-to-B1 phase transformation of zinc oxide nanoparticle (n-ZnO) structures was investigated in terms of their size and morphology. Nanorods, nanopencils, nanopyramids, nanowires, and nanotubes of the B4 phase in various sizes were directly built up by accounting for the atomic basis of the core and surface regions. The previously proposed transformation path was performed for constructing shapes and sizes compatible with B1 phases. Using systematic density functional theory, the surfaces were cleaved from the optimized crystal structures at different pressures in both the B4 and B1 phases. A method for calculating the surface energy at different pressures is proposed using an asymmetric slab model. Using the proposed model, the transition pressure of n-ZnO structures was found to significantly depend on their morphology and size, which is in good agreement with the available experimental reports.

  14. [Morphological changes in the thyroid gland of rats during various phases of the estral cycle].

    PubMed

    Pliner, L I; Ledovskaia, S M

    1975-08-01

    The functional state of the thyroid gland and the concentration of thyroid hormones in the peripheral blood were studied in 20 mature female albino rats during their estral cycle. Evaluation of the thyroid functional state was made according to data of histological, morphological (the diameter of folliculi, the height of the thyroid epithelium) and histochemical analysis (determination of NAD and NADP-dehydrogenase, succinatedehydrogenase, lactate dehydrogenase, peroxydase, acid and alkaline phosphatase) as well as biochemical determination of iodine bound with protein (IBP) in the blood plasma and investigation of the ratio of the parameters in question under conditions of the sex cycle. The cyclic changes of the morphological state of the thyroid gland attended by the phases of the estral cycle were revealed. The activation of the organ was observed in proestrus and estrus which was evidenced by high levels of activity of the enzymes under study, high concentration of IBP in the blood and increased height of thyreocytes. A decreased function of the thyroid parenchyma was observed at the period of metaestrus-diestrus.

  15. Location, morphology and function of nephrocytes in termites.

    PubMed

    Costa-Leonardo, Ana Maria; Janei, Vanelize; Laranjo, Lara Teixeira; Haifig, Ives

    2015-07-01

    Insect nephrocytes are cells bathed in hemolymph and considered to have an excretory function. These cells have ambiguous nomenclature and are understudied in termites. This study is the first report on the occurrence, morphology and function of nephrocytes in different termite castes. Cytological characteristics in specific developmental stages and castes enable physiological functions to be inferred. Perforate diaphragms indicate a role in filtration, while the extensive peripheral invaginations of the cell membrane suggest active endocytosis. A sequence of morphologies in putative digestive vacuoles infers a lysosomal system and the occurrence of phosphatases suggests a function involving detoxification of substances sequestered from hemolymph. Pericardical nephrocytes took up the dye trypan blue injected in live termites, suggesting their activity connected to the filtration of the hemolymph. Additionally, histochemical tests showed the existence of stored proteins in their cytoplasm. These cells present a well-developed Golgi apparatus and abundant rough endoplasmic reticulum, consistent with protein synthesis. This study highlights the importance of nephrocytes in Isoptera and opens perspectives for further research of these cells.

  16. Construction of Representative Pore Morphologies in Disordered Nanoporous Two-Phase Materials

    SciTech Connect

    Toney, Michael F

    2003-04-01

    Materials with nanometer size heterogeneities are commonplace in the physical and biological sciences and often exhibit complex morphologies. Although this morphology has a dramatic effect on the materials' properties (e.g., transport and reaction processes), it is often difficult to accurately characterize. We describe a method, using a novel analysis of small angle x-ray scattering data, of generating representative three-dimensional morphologies of isotropic two-phase materials (one class of heterogeneous materials) where the morphology is disordered. This is applied to thin films containing nanometer sized pores with a range of porosities (4-44%). These representations provide a visualization of the pore morphology, give the pore size scale and extent of interconnection, and permit the determination of the transitions from closed pore to interconnected pores to bicontinuous morphology. This methodology will be valuable for characterizing two-phase systems, such as polymer blends, microemulsions, porous geological materials, bones, cements and ceramics.

  17. Morphology and function of Neandertal and modern human ear ossicles

    PubMed Central

    David, Romain; Gunz, Philipp; Schmidt, Tobias; Spoor, Fred; Hublin, Jean-Jacques

    2016-01-01

    The diminutive middle ear ossicles (malleus, incus, stapes) housed in the tympanic cavity of the temporal bone play an important role in audition. The few known ossicles of Neandertals are distinctly different from those of anatomically modern humans (AMHs), despite the close relationship between both human species. Although not mutually exclusive, these differences may affect hearing capacity or could reflect covariation with the surrounding temporal bone. Until now, detailed comparisons were hampered by the small sample of Neandertal ossicles and the unavailability of methods combining analyses of ossicles with surrounding structures. Here, we present an analysis of the largest sample of Neandertal ossicles to date, including many previously unknown specimens, covering a wide geographic and temporal range. Microcomputed tomography scans and 3D geometric morphometrics were used to quantify shape and functional properties of the ossicles and the tympanic cavity and make comparisons with recent and extinct AMHs as well as African apes. We find striking morphological differences between ossicles of AMHs and Neandertals. Ossicles of both Neandertals and AMHs appear derived compared with the inferred ancestral morphology, albeit in different ways. Brain size increase evolved separately in AMHs and Neandertals, leading to differences in the tympanic cavity and, consequently, the shape and spatial configuration of the ossicles. Despite these different evolutionary trajectories, functional properties of the middle ear of AMHs and Neandertals are largely similar. The relevance of these functionally equivalent solutions is likely to conserve a similar auditory sensitivity level inherited from their last common ancestor. PMID:27671643

  18. Morphology and function of isolated hepatocytes transplanted into rat spleen.

    PubMed

    Mito, M; Ebata, H; Kusano, M; Onishi, T; Saito, T; Sakamoto, S

    1979-12-01

    Hepatocytes isolated by the collagenase digestive method were transplanted into the spleens of syngeneic rats. Morphology and function of the hepatocytes in the spleen were investigated for 12 to 17 months after transplantation. The transplanted hepatocytes proliferated and reconfigured in the spleen without direct perfusion of portal venous blood and with the presence of an intact host liver. Fourteen to 17 months after transplantation, the hepatocytes which had formed a demarcated nodule occupied approximately 40% of the area of the splenic parenchyma without undifferentiation on microscopic examination. However, the weight of the hepatized spleen did not increase beyond the weight of a normal spleen and the weight of the host liver that had normal morphology also did not differ from a normal liver. Light and electron microscopic studies demonstrated differentiated cord structure and normal architecture for each heptocyte. Furthermore, the hepatized spleen synthesized albumin and glycogen as demonstrated by immunofluorescence and histochemical studies. Ammonia tolerance and indocyanine green clearance tests revealed functioning hepatocytes in the spleen proper. These results indicate that our experimental model lends itself well to investigations in cell growth mechanism and that hepatocellular transplantation has potential clinical application to compensate for impaired hepatic function.

  19. Structure, morphology and functionality of acetylated and oxidised barley starches.

    PubMed

    El Halal, Shanise Lisie Mello; Colussi, Rosana; Pinto, Vânia Zanella; Bartz, Josiane; Radunz, Marjana; Carreño, Neftali Lenin Villarreal; Dias, Alvaro Renato Guerra; Zavareze, Elessandra da Rosa

    2015-02-01

    Acetylation and oxidation are chemical modifications which alter the properties of starch. The degree of modification of acetylated and oxidized starches is dependent on the catalyst and active chlorine concentrations, respectively. The objective of this study was to evaluate the effect of acetylation and oxidation on the structural, morphological, physical-chemical, thermal and pasting properties of barley starch. Barley starches were acetylated at different catalyst levels (11%, 17%, and 23% of NaOH solution) and oxidized at different sodium hypochlorite concentrations (1.0%, 1.5%, and 2.0% of active chlorine). Fourier-transformed infrared spectroscopy (FTIR), X-ray diffractograms, thermal, morphological, and pasting properties, swelling power and solubility of starches were evaluated. The degree of substitution (DS) of the acetylated starches increased with the rise in catalyst concentration. The percentage of carbonyl (CO) and carboxyl (COOH) groups in oxidized starches also increased with the rise of active chlorine level. The presence of hydrophobic acetyl groups, carbonyl and carboxyl groups caused a partial disorganization and depolymerization of starch granules. The structural, morphological and functional changes in acetylated and oxidized starches varied according to reaction conditions. Acetylation makes barley starch more hydrophobic by the insertion of acetyl groups. Also the oxidation promotes low retrogradation and viscosity. All these characteristics are important for biodegradable film production.

  20. Functional traits and root morphology of alpine plants

    PubMed Central

    Pohl, Mandy; Stroude, Raphaël; Buttler, Alexandre; Rixen, Christian

    2011-01-01

    Background and Aims Vegetation has long been recognized to protect the soil from erosion. Understanding species differences in root morphology and functional traits is an important step to assess which species and species mixtures may provide erosion control. Furthermore, extending classification of plant functional types towards root traits may be a useful procedure in understanding important root functions. Methods In this study, pioneer data on traits of alpine plant species, i.e. plant height and shoot biomass, root depth, horizontal root spreading, root length, diameter, tensile strength, plant age and root biomass, from a disturbed site in the Swiss Alps are presented. The applicability of three classifications of plant functional types (PFTs), i.e. life form, growth form and root type, was examined for above- and below-ground plant traits. Key Results Plant traits differed considerably among species even of the same life form, e.g. in the case of total root length by more than two orders of magnitude. Within the same root diameter, species differed significantly in tensile strength: some species (Geum reptans and Luzula spicata) had roots more than twice as strong as those of other species. Species of different life forms provided different root functions (e.g. root depth and horizontal root spreading) that may be important for soil physical processes. All classifications of PFTs were helpful to categorize plant traits; however, the PFTs according to root type explained total root length far better than the other PFTs. Conclusions The results of the study illustrate the remarkable differences between root traits of alpine plants, some of which cannot be assessed from simple morphological inspection, e.g. tensile strength. PFT classification based on root traits seems useful to categorize plant traits, even though some patterns are better explained at the individual species level. PMID:21795278

  1. Proposed Functional Description for Phased Arrays

    NASA Technical Reports Server (NTRS)

    Jackson, Deborah

    1996-01-01

    Generally speaking, many photonic engineers, while working in a systems development mode, still focus on presenting the unique physical details of the optical elements, instead of using functional representation to describe the system. The purpose of this presentation is to introduce symbols that can be used to represent the functional intent of most of the phased array architecture.

  2. Effect of Phase Contiguity and Morphology on the Evolution of Deformation Texture in Two-Phase Alloys

    NASA Astrophysics Data System (ADS)

    Gurao, N. P.; Suwas, Satyam

    2017-02-01

    Deformation texture evolution in two-phase xFe- yNi-(100- x- y)Cr model alloys and Ti-13Nb-13Zr alloy was studied during rolling to develop an understanding of micro-mechanisms of deformation in industrially relevant two-phase FCC-BCC steels and HCP-BCC titanium alloys, respectively. It was found that volume fraction and contiguity of phases lead to systematic changes in texture, while morphology affects the strength of texture. There was a characteristic change in texture from typical Brass-type to a weaker Copper-type texture in the austenite phase accompanied with a change from alpha fiber to gamma fiber in ferrite phase for Fe-Ni-Cr alloys with increase in fraction of harder ferrite phase. However, similar characteristic texture evolution was noted in both α and β phase irrespective of the different initial morphologies in Ti-13Nb-13Zr alloy. Viscoplastic self-consistent simulations with two-phase scheme were able to qualitatively predict texture evolution in individual phases. It is proposed that the transition from iso-strain-type behavior for equiaxed microstructure at low strain to iso-stress-type behavior at higher strain is aided by the presence of higher volume fraction of the second phase and increasing aspect ratio of individual phases in two-phase alloys.

  3. Reevaluating the functional implications of Australopithecus afarensis navicular morphology.

    PubMed

    Prang, Thomas C

    2016-08-01

    The longitudinal arch is a unique characteristic of the human foot, yet the timing and pattern of its evolution remain controversial, in part due to the disagreement among researchers over which skeletal traits are the best indicators of its presence or absence. The small size of the human navicular tuberosity has previously been linked to the presence of a longitudinal arch, implying that the large tuberosity of early hominins such as Australopithecus afarensis reflects a flat foot. However, this hypothesis is at odds with other evidence of pedal form and function, such as metatarsal, tarsal, and footprint morphology, which show that a longitudinal arch was probably present in A. afarensis. This study reevaluates the morphometric affinities of the A. afarensis naviculars among other Plio-Pleistocene fossil hominins and anthropoid primates (N = 170). Multivariate cluster analyses show that all fossil hominin naviculars, including those attributed to A. afarensis, are most similar to modern humans. A measure of navicular tuberosity size quantified as the ratio of the tuberosity volume to the surface area of the talar facet shows that Ateles has the largest navicular tuberosity among the anthropoid sample and that there is no difference between highly arboreal and terrestrial taxa in this metric (e.g., Hylobates and Gorilla beringei). Instead, a relatively large navicular tuberosity may reflect the development of leg musculature associated with ankle plantarflexion. The functional inferences derived from the morphology of the A. afarensis naviculars are consistent with the morphology of the Laetoli footprints.

  4. Functional and morphological plasticity of crocodile (Crocodylus porosus) salt glands.

    PubMed

    Cramp, Rebecca L; Meyer, Edward A; Sparks, Nicole; Franklin, Craig E

    2008-05-01

    The estuarine crocodile, Crocodylus porosus, inhabits both freshwater and hypersaline waterways and maintains ionic homeostasis by excreting excess sodium and chloride ions via lingual salt glands. In the present study, we sought to investigate the phenotypic plasticity, both morphological and functional, in the lingual salt glands of the estuarine crocodile associated with chronic exposure to freshwater (FW) and saltwater (SW) environments. Examination of haematological parameters indicated that there were no long-term disruptions to ionic homeostasis with prolonged exposure to SW. Maximal secretory rates from the salt glands of SW-acclimated animals (100.8+/-14.7 micromol 100 g(-0.7) body mass h(-1)) were almost three times greater than those of FW-acclimated animals (31.6+/-6.2 micromol 100 g(-0.7) body mass h(-1)). There were no differences in the mass-specific metabolic rate of salt gland tissue slices from FW- and SW-acclimated animals (558.9+/-49.6 and 527.3+/-142.8 microl O(2) g(-1) h(-1), respectively). Stimulation of the tissue slices from SW-acclimated animals by methacholine resulted in a 33% increase in oxygen consumption rate. There was no significant increase in the metabolic rate of tissues from FW-acclimated animals in response to methacholine. Morphologically, the secretory cells from the salt glands of SW-acclimated animals were larger than those of FW-acclimated animals. In addition, there were significantly more mitochondria per unit volume in secretory tissue from SW-acclimated animals. The results from this study demonstrate that the salt glands of C. porosus are phenotypically plastic, both morphologically and functionally and acclimate to changes in environmental salinity.

  5. Evolution and Functional Morphology of the Proboscis in Kalyptorhynchia (Platyhelminthes)

    PubMed Central

    Smith, Julian P. S.; Litvaitis, Marian K.; Gobert, Stefan; Uyeno, Theodore; Artois, Tom

    2015-01-01

    Predatory flatworms belonging to the taxon Kalyptorhynchia are characterized by an anterior muscular proboscis that they use to seize prey. In many cases, the proboscis is armed with hooks, derived either from the extracellular matrix that surrounds the muscles or from intracellular deposits in the epithelium covering the proboscis. Glands associated with the proboscis reportedly are venomous; however, there are few direct tests of this hypothesis. This article reviews the structure and current knowledge of the function of the proboscis in the Kalyptorhynchia, points to areas in which the current understanding of phylogenetic relationships within this taxon is incongruent with our hypothesis of how the proboscis evolved, and addresses areas in need of further research, especially as regards functional morphology and biomechanics. PMID:26002347

  6. Morphological and textural characterization of functionalized particulate silica xerogels

    NASA Astrophysics Data System (ADS)

    de Miranda, Lazaro A.; Mohallem, Nelcy D. S.; de Magalhães, Welington F.

    2006-03-01

    The functionalization of xerogels for use in chromatography and catalysis was carried out by solubilization of amorphous silica using a soxhlet extractor. Xerogels were prepared by sol-gel method using tetraethoxysilane, TEOS, ethanol, and water in a 1/3/10 molar ratio with HCl and HF as catalysts. The samples were prepared in monolithic form and dried at 70 °C and 550 °C for 1 h each. After functionalization, changes in textural and morphological characteristics of xerogels were investigated by means of nitrogen gas adsorption, positron annihilation lifetime spectroscopy (PALS), and scanning electron microscopy (SEM). As the analysis methods are based on different physical principles, the results are complementary, leading to a good knowledge of the texture of the samples studied.

  7. Evolution and Functional Morphology of the Proboscis in Kalyptorhynchia (Platyhelminthes).

    PubMed

    Smith, Julian P S; Litvaitis, Marian K; Gobert, Stefan; Uyeno, Theodore; Artois, Tom

    2015-08-01

    Predatory flatworms belonging to the taxon Kalyptorhynchia are characterized by an anterior muscular proboscis that they use to seize prey. In many cases, the proboscis is armed with hooks, derived either from the extracellular matrix that surrounds the muscles or from intracellular deposits in the epithelium covering the proboscis. Glands associated with the proboscis reportedly are venomous; however, there are few direct tests of this hypothesis. This article reviews the structure and current knowledge of the function of the proboscis in the Kalyptorhynchia, points to areas in which the current understanding of phylogenetic relationships within this taxon is incongruent with our hypothesis of how the proboscis evolved, and addresses areas in need of further research, especially as regards functional morphology and biomechanics.

  8. Leptin regulation of neuronal morphology and hippocampal synaptic function

    PubMed Central

    Harvey, Jenni

    2013-01-01

    The central actions of the hormone leptin in regulating energy homeostasis via the hypothalamus are well documented. However, evidence is growing that this hormone can also modify the structure and function of synapses throughout the CNS. The hippocampus is a region of the forebrain that plays a crucial role in associative learning and memory and is an area also highly vulnerable to neurodegenerative processes. Recent studies indicate that leptin is a potential cognitive enhancer as it modulates the cellular processes underlying hippocampal-dependent learning and memory including dendritic morphology, glutamate receptor trafficking and activity-dependent synaptic plasticity. Here, we review the recent evidence implicating the hormone leptin as a key regulator of hippocampal synaptic function and discuss the role of leptin receptor-driven lipid signaling pathways involved in this process. PMID:23964236

  9. [Morphology: a critical phase in the diagnosis of myelodysplastic syndromes].

    PubMed

    Zini, Gina

    2014-03-01

    Diagnosis and classification of myelodysplastic syndromes (MDS) are based on the integration of morphology, immunophenotype, histology, genetics and molecular analysis. The role of cytomorphology in this context, however, remains fundamental and preliminary to the application of the other methods. The first modern classification of MDS, originally published by the FAB (French-American-British) Group in 1985, was based on the recognition of five different diagnostic categories. The more recent 2008 WHO classification of hematopoietic neoplasms has widened and modified the FAB approach, by including seven different cytomorphological entities and decreasing the threshold of the blast cell percentage to 19% for the discrimination of MDS from acute myeloid leukemias. In addition, chronic myelomonocytic leukemia is now included in the new group or MDS/myeloproliferative neoplasms. Finally, precise quantitative and qualitative criteria are provided, with the aim to improve microscope method standardization.

  10. Four reversible and reconfigurable structures for three-phase emulsions: extended morphologies and applications

    PubMed Central

    Ge, Xue-hui; Geng, Yu-hao; Zhang, Qiao-chu; Shao, Meng; Chen, Jian; Luo, Guang-sheng; Xu, Jian-hong

    2017-01-01

    Here in this article, we classify and conclude the four morphologies of three-phase emulsions. Remarkably, we achieve the reversible transformations between every shape. Through theoretical analysis, we choose four liquid systems to form these four morphologies. Then monodispersed droplets with these four morphologies are formed through a microfluidic device and captured in a petri-dish. By replacing their ambient solution of the captured emulsions, in-situ morphology transformations between each shape are achieved. The process is well recorded through photographs and videos and they are systematical and reversible. Finally, we use the droplets structure to form an on-off switch to start and shut off the evaporation of one volatile phase to achieve the process monitoring. This could be used to initiate and quench a reaction, which offers a novel idea to achieve the switchable and reversible reaction control in multiple-phase reactions. PMID:28198444

  11. Four reversible and reconfigurable structures for three-phase emulsions: extended morphologies and applications

    NASA Astrophysics Data System (ADS)

    Ge, Xue-Hui; Geng, Yu-Hao; Zhang, Qiao-Chu; Shao, Meng; Chen, Jian; Luo, Guang-Sheng; Xu, Jian-Hong

    2017-02-01

    Here in this article, we classify and conclude the four morphologies of three-phase emulsions. Remarkably, we achieve the reversible transformations between every shape. Through theoretical analysis, we choose four liquid systems to form these four morphologies. Then monodispersed droplets with these four morphologies are formed through a microfluidic device and captured in a petri-dish. By replacing their ambient solution of the captured emulsions, in-situ morphology transformations between each shape are achieved. The process is well recorded through photographs and videos and they are systematical and reversible. Finally, we use the droplets structure to form an on-off switch to start and shut off the evaporation of one volatile phase to achieve the process monitoring. This could be used to initiate and quench a reaction, which offers a novel idea to achieve the switchable and reversible reaction control in multiple-phase reactions.

  12. Morphological and functional investigations of neuroendocrine tumors of the pancreas.

    PubMed

    Pereira, Philippe L; Wiskirchen, Jakub

    2003-09-01

    Neuroendocrine tumors of the pancreas are rare neoplasms arising predominantly from the pancreatic islets of Langerhans and are thus known as islet cell tumors. More than the half of all neuroendocrine tumors are called functioning islet cell tumors because they secrete one or more biologically active peptides that may produce clinical symptoms. Clinical diagnosis of non-functioning, i.e., biologically inactive, tumors is often delayed and patients tend to present with advanced tumors (size greater than 5 cm) that are easily localized by using conventional imaging modalities. On the other hand, symptoms of functioning islet cell tumors usually appear early in the clinical course, rendering the preoperative localization of these small hormone-producing tumors (size less than 2 cm) difficult with non-invasive methods. Since functioning islet cell tumors can often be cured by surgical resection, invasive procedures are warranted when necessary for localization diagnosis. Failure to search for, detect, and resect these small tumors will invariably result in persistent symptoms. Regarding the unsatisfactory results of morphological imaging methods, functional studies, especially arterial stimulation with hepatic venous samplings, may provide a preoperative regionalization of the pancreatic adenoma, regardless of its size.

  13. A reappraisal of azhdarchid pterosaur functional morphology and paleoecology.

    PubMed

    Witton, Mark P; Naish, Darren

    2008-05-28

    Azhdarchid pterosaurs were among the most widespread and successful of pterosaur clades, but their paleoecology remains controversial. Morphological features common to all azhdarchids include a long, shallow rostrum; elongate, cylindrical cervical vertebrae that formed a long and unusually inflexible neck; and proportionally short wings with an abbreviated fourth phalanx. While azhdarchids have been imagined as vulture-like scavengers, sediment probers, swimmers, waders, aerial predators, or stork-like generalists, most recent authors have regarded them as skim-feeders, trawling their lower jaws through water during flight and seizing aquatic prey from the water's surface. Although apparently widely accepted, the skim-feeding model lacks critical support from anatomy and functional morphology. Azhdarchids lack the many cranial specialisations exhibited by extant skim-feeding birds, most notably the laterally compressed lower jaw and shock absorbing apparatus required for this feeding style. Well-preserved azhdarchid skulls are rare, but their rostra and lower jaws appear to have been sub-triangular in cross-section, and thus dissimilar to those of skim-feeders and sediment probers. Taphonomic data indicates that azhdarchids predominately inhabited inland settings, and azhdarchid morphology indicates that they were poorly suited for all proposed lifestyles bar wading and terrestrial foraging. However, azhdarchid footprints show that their feet were relatively small, padded and slender, and thus not well suited for wading. We argue that azhdarchids were stork- or ground hornbill-like generalists, foraging in diverse environments for small animals and carrion. Proficient terrestrial abilities and a relatively inflexible neck are in agreement with this interpretation.

  14. A Reappraisal of Azhdarchid Pterosaur Functional Morphology and Paleoecology

    PubMed Central

    Witton, Mark P.; Naish, Darren

    2008-01-01

    Azhdarchid pterosaurs were among the most widespread and successful of pterosaur clades, but their paleoecology remains controversial. Morphological features common to all azhdarchids include a long, shallow rostrum; elongate, cylindrical cervical vertebrae that formed a long and unusually inflexible neck; and proportionally short wings with an abbreviated fourth phalanx. While azhdarchids have been imagined as vulture-like scavengers, sediment probers, swimmers, waders, aerial predators, or stork-like generalists, most recent authors have regarded them as skim-feeders, trawling their lower jaws through water during flight and seizing aquatic prey from the water's surface. Although apparently widely accepted, the skim-feeding model lacks critical support from anatomy and functional morphology. Azhdarchids lack the many cranial specialisations exhibited by extant skim-feeding birds, most notably the laterally compressed lower jaw and shock absorbing apparatus required for this feeding style. Well-preserved azhdarchid skulls are rare, but their rostra and lower jaws appear to have been sub-triangular in cross-section, and thus dissimilar to those of skim-feeders and sediment probers. Taphonomic data indicates that azhdarchids predominately inhabited inland settings, and azhdarchid morphology indicates that they were poorly suited for all proposed lifestyles bar wading and terrestrial foraging. However, azhdarchid footprints show that their feet were relatively small, padded and slender, and thus not well suited for wading. We argue that azhdarchids were stork- or ground hornbill-like generalists, foraging in diverse environments for small animals and carrion. Proficient terrestrial abilities and a relatively inflexible neck are in agreement with this interpretation. PMID:18509539

  15. Monitoring cell morphology during necrosis and apoptosis by quantitative phase imaging

    NASA Astrophysics Data System (ADS)

    Mugnano, Martina; Calabuig, Alejandro; Grilli, Simonetta; Miccio, Lisa; Ferraro, Pietro

    2015-05-01

    Cellular morphology changes and volume alterations play significant roles in many biological processes and they are mirrors of cell functions. In this paper, we propose the Digital Holographic microscope (DH) as a non-invasive imaging technique for a rapid and accurate extraction of morphological information related to cell death. In particular, we investigate the morphological variations that occur during necrosis and apoptosis. The study of necrosis is extremely important because it is often associated with unwarranted loss of cells in human pathologies such as ischemia, trauma, and some forms of neurodegeneration; therefore, a better elucidation in terms of cell morphological changes could pave the way for new treatments. Also, apoptosis is extremely important because it's involved in cancer, both in its formation and in medical treatments. Because the inability to initiate apoptosis enhances tumour formation, current cancer treatments target this pathway. Within this framework, we have developed a transmission off-axis DH apparatus integrated with a micro incubator for investigation of living cells in a temperature and CO2 controlled environment. We employ DH to analyse the necrosis cell death induced by laser light (wavelength 473 nm, light power 4 mW). We have chosen as cellular model NIH 3T3 mouse embryonic fibroblasts because their adhesive features such as morphological changes, and the time needed to adhere and spread have been well characterized in the literature. We have monitored cell volume changes and morphological alterations in real time in order to study the necrosis process accurately and quantitatively. Cell volume changes were evaluated from the measured phase changes of light transmitted through cells. Our digital holographic experiments showed that after exposure of cells to laser light for 90-120 min., they swell and then take on a balloon-like shape until the plasma membrane ruptures and finally the cell volume decreases. Furthermore, we

  16. Morphology and polymorphic phase changes of calcium carbonate micro/nanocrystals using fruit extracts.

    PubMed

    Ankamwar, Balaprasad

    2011-05-01

    This study reveals the morphology and polymorphic phase changes of calcium carbonate crystals into a mixture of calcite and aragonite micro/nanocrystals of interesting morphology at room temperature by a simple reaction with fruit extracts of Tamarindus indica and Emblica officinalis respectively by mixing CaCO3 solutions with their corresponding extracts. The control experiments were carried out to establish the plausible role of tartaric acid from Tamarindus indica and ascorbic acid from Emblica officinalis in this regard. The quantitative determination of CaCO3 phases was done based on the use of intensities obtained from corresponding XRD spectrum. The molar % of aragonite was found to be more in case of TA and AA rather than TI and EO respectively, however the calcite was observed to be the predominant phase in all four reactions. Interestingly, the TI changes the rhombohedral morphology of calcite to elongated rods, whereas EO induces a great polymorphic phase change.

  17. Functional and morphological differences between human alveolar and interstitial macrophages.

    PubMed

    Fathi, M; Johansson, A; Lundborg, M; Orre, L; Sköld, C M; Camner, P

    2001-04-01

    Macrophages play an essential role in pulmonary host defense. They are, however, a heterogeneous cell population located in different lung compartments. This study was designed to elucidate differences between two macrophage populations obtained from the human lung, i.e., alveolar macrophages (AM) and interstitial macrophages (IM). Macroscopically tumor-free lung segments from nine patients undergoing lobectomy or pulmectomy were studied. All patients had a diagnosis of primary lung cancer. AM were recovered by bronchoalveolar lavage and IM were isolated by mechanical fragmentation of the lavaged lung segments followed by enzymatic treatment. The cell fractions were analyzed with respect to morphology (transmission electron microscopy) and function (phagocytosis). The cells in the IM fraction were smaller (7.6 +/- 1.8 microm (mean +/- SD) compared with 16.0 +/- 4.1 microm) and morphologically more heterogeneous than those in the AM fraction. Interestingly, a considerable portion of the cells in the IM fraction had a typical AM-like appearance. Despite this, the AM fraction had a higher phagocytic activity compared to IM, with faster attachment and ingestion processes (P <0.001 for both). We conclude that the heterogeneity of human lung macrophages must be taken into consideration when their role in the inflammatory response is studied.

  18. Thymus and aging: morphological, radiological, and functional overview.

    PubMed

    Rezzani, Rita; Nardo, Lorenzo; Favero, Gaia; Peroni, Michele; Rodella, Luigi Fabrizio

    2014-02-01

    Aging is a continuous process that induces many alterations in the cytoarchitecture of different organs and systems both in humans and animals. Moreover, it is associated with increased susceptibility to infectious, autoimmune, and neoplastic processes. The thymus is a primary lymphoid organ responsible for the production of immunocompetent T cells and, with aging, it atrophies and declines in functions. Universality of thymic involution in all species possessing thymus, including human, indicates it as a long-standing evolutionary event. Although it is accepted that many factors contribute to age-associated thymic involution, little is known about the mechanisms involved in the process. The exact time point of the initiation is not well defined. To address the issue, we report the exact age of thymus throughout the review so that readers can have a nicely pictured synoptic view of the process. Focusing our attention on the different stages of the development of the thymus gland (natal, postnatal, adult, and old), we describe chronologically the morphological changes of the gland. We report that the thymic morphology and cell types are evolutionarily preserved in several vertebrate species. This finding is important in understanding the similar problems caused by senescence and other diseases. Another point that we considered very important is to indicate the assessment of the thymus through radiological images to highlight its variability in shape, size, and anatomical conformation.

  19. Morphological and functional aspects of progenitors perturbed in cortical malformations

    PubMed Central

    Bizzotto, Sara; Francis, Fiona

    2015-01-01

    In this review, we discuss molecular and cellular mechanisms important for the function of neuronal progenitors during development, revealed by their perturbation in different cortical malformations. We focus on a class of neuronal progenitors, radial glial cells (RGCs), which are renowned for their unique morphological and behavioral characteristics, constituting a key element during the development of the mammalian cerebral cortex. We describe how the particular morphology of these cells is related to their roles in the orchestration of cortical development and their influence on other progenitor types and post-mitotic neurons. Important for disease mechanisms, we overview what is currently known about RGC cellular components, cytoskeletal mechanisms, signaling pathways and cell cycle characteristics, focusing on how defects lead to abnormal development and cortical malformation phenotypes. The multiple recent entry points from human genetics and animal models are contributing to our understanding of this important cell type. Combining data from phenotypes in the mouse reveals molecules which potentially act in common pathways. Going beyond this, we discuss future directions that may provide new data in this expanding area. PMID:25729350

  20. Functional morphology of the muscular sling at the pectoral girdle in tree sloths: convergent morphological solutions to new functional demands?

    PubMed

    Nyakatura, John A; Fischer, Martin S

    2011-09-01

    Recent phylogenetic analyses imply a diphyly of tree sloths and a convergent evolution of their obligatory suspensory locomotion. In mammals the extrinsic shoulder musculature forms a 'muscular sling' to support the trunk in quadrupedal postures. In addition, the extrinsic pectoral muscles are responsible for moving the proximal forelimb elements during locomotion. Due to the inverse orientation of the body in regard to the gravitational force, the muscular sling as configured as in pronograde mammals is unsuited to suspend the weight of the thorax in sloths. We here review the muscular topography of the shoulder in Choloepus didactylus and Bradypus variegatus in the light of presumably convergent evolution to adapt to the altered functional demands of the inverse orientation of the body. In addition, we venture to deduce the effect of the shoulder musculature of C. didactylus during locomotion based on previously published 3D kinematic data. Finally, we assess likely convergences in the muscular topography of both extant sloth lineages to test the hypothesis that convergent evolution is reflected by differing morphological solutions to the same functional demands posed by the suspensory posture. Muscular topography of the shoulder in C. didactylus is altered from the plesiomorphic condition of pronograde mammals, whereas the shoulder in B. variegatus more closely resembles the general pattern. Overall kinematics as well as the muscles suitable for pro- and retraction of the forelimb were found to be largely comparable to pronograde mammals in C. didactylus. We conclude that most of the peculiar topography of extrinsic forelimb musculature can be attributed to the inverse orientation of the body. These characteristics are often similar in both genera, but we also identified different morphological solutions that evolved to satisfy the new functional demands and are indicative of convergent evolution. We suggest that the shared phylogenetic heritage canalized

  1. Functional morphological characteristics of the interdigital sinus in the sheep.

    PubMed

    Pourlis, A F

    2010-05-01

    The present paper describes two distinct morphological features of ovine interdigital sinus, which were examined by means of scanning electron microscopy. In the sweat glandular component, acini with epithelial cells exhibiting a paved appearance and apocrine secretion were observed. In the same gland, other acini with cells exhibiting different luminal surfaces and simultaneous apocrine and merocrine secretion were recorded. The numerous hairs embedded within the waxy material of the sinus exhibited two types. The first type, with a round profile, had a special leaflet structure on the tip, whereas the second type had a convex profile. The comparative differences and probable functional relations of these integumentary structures are discussed. The mixed picture of the epithelial cells of the sweat glands suggests the release of different products. The hair microstructure correlated with the mechanism of hold and release of the secretory material of the interdigital sinus.

  2. Interfacial thiol-isocyanate reactions for functional nanocarriers: a facile route towards tunable morphologies and hydrophilic payload encapsulation.

    PubMed

    Kuypers, Sören; Pramanik, Sumit Kumar; D'Olieslaeger, Lien; Reekmans, Gunter; Peters, Martijn; D'Haen, Jan; Vanderzande, Dirk; Junkers, Thomas; Adriaensens, Peter; Ethirajan, Anitha

    2015-11-11

    Functional nanocarriers were synthesized using an in situ inverse miniemulsion polymerization employing thiol-isocyanate reactions at the droplet interface to encapsulate hydrophilic payloads. The morphology of the nanocarriers is conveniently tunable by varying the reaction conditions and the dispersions are easily transferable to the aqueous phase.

  3. [Functional morphology of the submandibular salivary glands of white rats during aging involution].

    PubMed

    Rybakova, M G

    1979-12-01

    Functional morphology of different zones of submandibular glands of albino rats was studied quantitatively with due regard for the stages of neuroendocrine system involution. It is shown that function of salivary glands during ageing is not altered; cyclic fluctuations with estral cycle phases are maintained similarly to those in young animals. But the basal level of proteins and mucopolysaccharides is reduced, their mean levels being equal to the minimal level in young animals. On the other hand, activation of enzymes responsible for energy and transport processes takes place and their relationships change. The data obtained prove the relationship between salivary and endocrine glands and confirm the viewpoint that in early age involution disintegration occurs between different parameters of the functional activity of salivary glands rather than there take place changes in their function.

  4. Phase separation in thermal systems: a lattice Boltzmann study and morphological characterization.

    PubMed

    Gan, Yanbiao; Xu, Aiguo; Zhang, Guangcai; Li, Yingjun; Li, Hua

    2011-10-01

    We investigate thermal and isothermal symmetric liquid-vapor separations via a fast Fourier transform thermal lattice Boltzmann (FFT-TLB) model. Structure factor, domain size, and Minkowski functionals are employed to characterize the density and velocity fields, as well as to understand the configurations and the kinetic processes. Compared with the isothermal phase separation, the freedom in temperature prolongs the spinodal decomposition (SD) stage and induces different rheological and morphological behaviors in the thermal system. After the transient procedure, both the thermal and isothermal separations show power-law scalings in domain growth, while the exponent for thermal system is lower than that for isothermal system. With respect to the density field, the isothermal system presents more likely bicontinuous configurations with narrower interfaces, while the thermal system presents more likely configurations with scattered bubbles. Heat creation, conduction, and lower interfacial stresses are the main reasons for the differences in thermal system. Different from the isothermal case, the release of latent heat causes the changing of local temperature, which results in new local mechanical balance. When the Prandtl number becomes smaller, the system approaches thermodynamical equilibrium much more quickly. The increasing of mean temperature makes the interfacial stress lower in the following way: σ=σ(0)[(T(c)-T)/(T(c)-T(0))](3/2), where T(c) is the critical temperature and σ(0) is the interfacial stress at a reference temperature T(0), which is the main reason for the prolonged SD stage and the lower growth exponent in the thermal case. Besides thermodynamics, we probe how the local viscosities influence the morphology of the phase separating system. We find that, for both the isothermal and thermal cases, the growth exponents and local flow velocities are inversely proportional to the corresponding viscosities. Compared with the isothermal case, the

  5. The small GTPase Arf1 modulates mitochondrial morphology and function.

    PubMed

    Ackema, Karin B; Hench, Jürgen; Böckler, Stefan; Wang, Shyi Chyi; Sauder, Ursula; Mergentaler, Heidi; Westermann, Benedikt; Bard, Frédéric; Frank, Stephan; Spang, Anne

    2014-11-18

    The small GTPase Arf1 plays critical roles in membrane traffic by initiating the recruitment of coat proteins and by modulating the activity of lipid-modifying enzymes. Here, we report an unexpected but evolutionarily conserved role for Arf1 and the ArfGEF GBF1 at mitochondria. Loss of function of ARF-1 or GBF-1 impaired mitochondrial morphology and activity in Caenorhabditis elegans. Similarly, mitochondrial defects were observed in mammalian and yeast cells. In Saccharomyces cerevisiae, aberrant clusters of the mitofusin Fzo1 accumulated in arf1-11 mutants and were resolved by overexpression of Cdc48, an AAA-ATPase involved in ER and mitochondria-associated degradation processes. Yeast Arf1 co-fractionated with ER and mitochondrial membranes and interacted genetically with the contact site component Gem1. Furthermore, similar mitochondrial abnormalities resulted from knockdown of either GBF-1 or contact site components in worms, suggesting that the role of Arf1 in mitochondrial functioning is linked to ER-mitochondrial contacts. Thus, Arf1 is involved in mitochondrial homeostasis and dynamics, independent of its role in vesicular traffic.

  6. Morphology and functional roles of synoviocytes in the joint.

    PubMed

    Iwanaga, T; Shikichi, M; Kitamura, H; Yanase, H; Nozawa-Inoue, K

    2000-03-01

    The joint capsule exhibits a unique cellular lining in the luminal surface of the synovial membrane. The synovial intimal cells, termed synoviocytes, are believed to be responsible for the production of synovial fluid components, for absorption from the joint cavity, and for blood/synovial fluid exchanges, but their detailed structure and function as well as pathological changes remain unclear. Two types of synoviocytes, macrophagic cells (type A cells) and fibroblast-like cells (type B cells) have been identified. Type A synoviocytes are non-fixed cells that can phagocytose actively cell debris and wastes in the joint cavity, and possess an antigen-presenting ability. These type A cells, derived from blood-borne mononuclear cells, can be considered resident macrophages (tissue macrophages) like hepatic Kupffer cells. Type B synoviocytes are characterized by the rich existence of rough endoplasmic reticulum, and dendritic processes which form a regular network in the luminal surface of the synovial membrane. Their complex three-dimensional architecture was first revealed by our recent scanning electron microscopy of macerated samples. The type B cells, which are proper synoviocytes, are involved in production of specialized matrix constituents including hyaluronan, collagens and fibronectin for the intimal interstitium and synovial fluid. The proliferative potentials of type B cells in loco are much higher than type A cells, although the transformation of subintimal fibroblasts into type B cells can not be excluded. In some mammals, type B cells show features suggesting endocrine and sensory functions, but these are not recognized in other species. The synoviocytes, which form a discontinuous cell layer, develop both fragmented basement membranes around the cells and junctional apparatus such as desmosomes and gap junctions. For an exact understanding of the mechanism of arthritis, we need to establish the morphological background of synoviocytes as well as their

  7. Morphology effect on the light scattering and dynamic response of polymer network liquid crystal phase modulator.

    PubMed

    Xiangjie, Zhao; Cangli, Liu; Jiazhu, Duan; Jiancheng, Zeng; Dayong, Zhang; Yongquan, Luo

    2014-06-16

    Polymer network liquid crystal (PNLC) was one of the most potential liquid crystal for submillisecond response phase modulation, which was possible to be applied in submillisecond response phase only spatial light modulator. But until now the light scattering when liquid crystal director was reoriented by external electric field limited its phase modulation application. Dynamic response of phase change when high voltage was applied was also not elucidated. The mechanism that determines the light scattering was studied by analyzing the polymer network morphology by SEM method. Samples were prepared by varying the polymerization temperature, UV curing intensity and polymerization time. The morphology effect on the dynamic response of phase change was studied, in which high voltage was usually applied and electro-striction effect was often induced. The experimental results indicate that the polymer network morphology was mainly characterized by cross linked single fibrils, cross linked fibril bundles or even both. Although the formation of fibril bundle usually induced large light scattering, such a polymer network could endure higher voltage. In contrast, although the formation of cross linked single fibrils induced small light scattering, such a polymer network cannot endure higher voltage. There is a tradeoff between the light scattering and high voltage endurance. The electro-optical properties such as threshold voltage and response time were taken to verify our conclusion. For future application, the monomer molecular structure, the liquid crystal solvent and the polymerization conditions should be optimized to generate optimal polymer network morphology.

  8. Morphology and growth speed of hcp domains during shock-induced phase transition in iron.

    PubMed

    Pang, Wei-Wei; Zhang, Ping; Zhang, Guang-Cai; Xu, Ai-Guo; Zhao, Xian-Geng

    2014-01-10

    Emergence and time evolution of micro-structured new-phase domains play a crucial role in determining the macroscopic physical and mechanical behaviors of iron under shock compression. Here, we investigate, through molecular dynamics simulations and theoretical modelings, shock-induced phase transition process of iron from body-centered-cubic (bcc) to hexagonal-close-packed (hcp) structure. We present a central-moment method and a rolling-ball algorithm to calculate and analyze the morphology and growth speed of the hcp phase domains, and then propose a phase transition model to clarify our derived growth law of the phase domains. We also demonstrate that the new-phase evolution process undergoes three distinguished stages with different time scales of the hcp phase fraction in the system.

  9. Atomic level characterization of the morphology of phases in Chromindur magnetic alloys

    SciTech Connect

    Miller, M.K. ); Camus, P.P . Applied Superconductivity Center); Hetherington, M.G. . Dept. of Materials)

    1991-01-01

    The atom probe field ion microscope has been used to characterize the morphology and determine the compositions of the iron-rich {alpha} and chromium-enriched {alpha}{prime} phases produced during isothermal and step cooled heat treatments in a Chromindur 2 ductile permanent magnet alloy. The good magnetic properties of this material are due to a combination of the composition of the two phases and the isolated nature and size of the ferromagnetic {alpha} phase. The morphology of the {alpha} phase is produced as a result of the shape of the miscibility gap and the step-cooled heat treatment and is distinctly different from that formed during isothermal heat treatments. 6 refs., 3 figs., 4 tabs.

  10. Experimental investigations of the functional morphology of dragonfly wings

    NASA Astrophysics Data System (ADS)

    Rajabi, H.; Darvizeh, A.

    2013-08-01

    Nowadays, the importance of identifying the flight mechanisms of the dragonfly, as an inspiration for designing flapping wing vehicles, is well known. An experimental approach to understanding the complexities of insect wings as organs of flight could provide significant outcomes for design purposes. In this paper, a comprehensive investigation is carried out on the morphological and microstructural features of dragonfly wings. Scanning electron microscopy (SEM) and tensile testing are used to experimentally verify the functional roles of different parts of the wings. A number of SEM images of the elements of the wings, such as the nodus, leading edge, trailing edge, and vein sections, which play dominant roles in strengthening the whole structure, are presented. The results from the tensile tests indicate that the nodus might be the critical region of the wing that is subjected to high tensile stresses. Considering the patterns of the longitudinal corrugations of the wings obtained in this paper, it can be supposed that they increase the load-bearing capacity, giving the wings an ability to tolerate dynamic loading conditions. In addition, it is suggested that the longitudinal veins, along with the leading and trailing edges, are structural mechanisms that further improve fatigue resistance by providing higher fracture toughness, preventing crack propagation, and allowing the wings to sustain a significant amount of damage without loss of strength.

  11. Scaling and functional morphology in strigiform hind limbs

    PubMed Central

    Madan, Meena A.; Rayfield, Emily J.; Bright, Jen A.

    2017-01-01

    Strigiformes are an order of raptorial birds consisting exclusively of owls: the Tytonidae (barn owls) and the Strigidae (true owls), united by a suite of adaptations aiding a keen predatory lifestyle, including robust hind limb elements modified for grip strength. To assess variation in hind limb morphology, we analysed how the dimensions of the major hind limb elements in subfossil and modern species scaled with body mass. Comparing hind limb element length, midshaft width, and robusticity index (RI: ratio of midshaft width to maximum length) to body mass revealed that femoral and tibiotarsal width scale with isometry, whilst length scales with negative allometry, and close to elastic similarity in the tibiotarsus. In contrast, tarsometatarsus width shows strong positive allometry with body mass, whilst length shows strong negative allometry. Furthermore, the tarsometatarsi RI scales allometrically to mass0.028, whilst a weak relationship exists in femora (mass0.004) and tibiotarsi (mass0.004). Our results suggest that tarsometatarsi play a more substantial functional role than tibiotarsi and femora. Given the scaling relationship between tarsometatarsal width and robusticity to body mass, it may be possible to infer the body mass of prehistoric owls by analysing tarsometatarsi, an element that is frequently preserved in the fossil record of owls. PMID:28327549

  12. Phenomena affecting morphology of microporous poly(acrylonitrile) prepared via phase separation from solution

    SciTech Connect

    Legasse, R.R.; Weagley, R.J.; Leslie, P.K.; Schneider, D.A.

    1990-01-01

    This paper is concerned with controlling the morphology of microporous polymers prepared via thermal demixing of solutions. 2 wt % solutions of poly(acrylonitrile) in maleic anhydride, a poor solvent, are first cooled to produce separated polymer-rich and solvent-rich phases. Removing the solvent by freeze drying then produces a microporous material having a density of 33 mg/cm{sup 3}, a void fraction of 97%, and a pore size of about 10 {mu}m. We find that the morphology cannot be explained by existing models, which focus on phase diagrams and kinetics of phase transformations during cooling of the solution. In conflict with those models, we find that two radically different morphologies can be produced even when the polymer concentration and cooling path are held strictly constant. A hypothesis that polymer degradation causes the different morphologies is not supported by GPC, {sup 13}C NMR, and FTIR experiments. Instead, we offer evidence that the different microporous morphologies are caused by different polymer conformations in solutions having the same concentration and temperature. 11 refs., 3 figs.

  13. Ionic-liquid-assisted synthesis of YF{sub 3} with different crystalline phases and morphologies

    SciTech Connect

    Zhong Haoxiang; Hong Jianming; Cao Xiaofeng; Chen Xuetai Xue Ziling

    2009-03-05

    YF{sub 3} with different crystalline phases and morphologies have been prepared via a facile hydrothermal route assisted by imidazolium ionic liquids 1-butyl-3-methylimidazolium tetrafluoroborate (C{sub 4}mimBF{sub 4}) or 1-butyl-3-methylimidazolium hexafluorophosphate (C{sub 4}mimPF{sub 6}). The microstructures and morphologies of YF{sub 3} particles were characterized by X-ray powder diffraction, X-ray photoelectron spectra (XPS), transmission electron microscopy (TEM), high resolution electron microscopy (HRTEM) and field emission scanning electron microscopy (FESEM). Cubic and orthorhombic YF{sub 3} were selectively synthesized by adjusting the molar ratio of the reagents and using C{sub 4}mimBF{sub 4} as the fluoride source, while only orthorhombic YF{sub 3} was obtained using C{sub 4}mimPF{sub 6}, indicating that the crystalline phases and morphologies of the products were significantly influenced by fluoride source and reaction media.

  14. Effect of porous morphology on phase transition in vanadium dioxide thin films

    SciTech Connect

    Xu, Hui Yan; Ma, Fei; Huang, Yu Hong; Li, Jin Ping; Xu, Ke Wei

    2015-11-15

    Vanadium oxide (VO{sub 2}) thin films were prepared on Si (100) substrates by direct current magnetron sputtering at room temperature, and then, postannealing was conducted at 450 °C for 2 h in vacuum. Structural characterizations demonstrated that the thin films exhibited porous morphology upon thermal annealing and the porosity and pore size depended on the oxygen flow rate in the process of film fabrication. Raman spectra were measured in the temperature range of 303–343 K, and resistance measurement was conducted in the temperature range of 293–363 K, to study the influence of porous morphology on the phase transition in VO{sub 2} thin films. It was illustrated that the porous morphology could provide a free space to release the stress induced in the monoclinic-to-tetragonal phase transition of VO{sub 2}, and lower the transition temperature to a certain degree.

  15. Morphology Evolution of High Efficiency Perovskite Solar Cells via Vapor Induced Intermediate Phases.

    PubMed

    Zuo, Lijian; Dong, Shiqi; De Marco, Nicholas; Hsieh, Yao-Tsung; Bae, Sang-Hoon; Sun, Pengyu; Yang, Yang

    2016-12-07

    Morphology is critical component to achieve high device performance hybrid perovskite solar cells. Here, we develop a vapor induced intermediate phase (VIP) strategy to manipulate the morphology of perovskite films. By exposing the perovskite precursor films to different saturated solvent vapor atmospheres, e.g., dimethylformamide and dimethylsufoxide, dramatic film morphological evolution occurs, associated with the formation of different intermediate phases. We observe that the crystallization kinetics is significantly altered due to the formation of these intermediate phases, yielding highly crystalline perovskite films with less defect states and high carrier lifetimes. The perovskite solar cells with the reconstructed films exhibits the highest power conversion efficiency (PCE) up to 19.2% under 1 sun AM 1.5G irradiance, which is among the highest planar heterojunction perovskite solar cells. Also, the perovskite solar cells with VIP processing shows less hysteresis behavior and a stabilized power output over 18%. Our work opens up a new direction for morphology control through intermediate phase formation, and paves the way toward further enhancing the device performances of perovskite solar cells.

  16. Evolution and control of the phase competition morphology in a manganite film.

    PubMed

    Zhou, Haibiao; Wang, Lingfei; Hou, Yubin; Huang, Zhen; Lu, Qingyou; Wu, Wenbin

    2015-11-25

    The competition among different phases in perovskite manganites is pronounced since their energies are very close under the interplay of charge, spin, orbital and lattice degrees of freedom. To reveal the roles of underlying interactions, many efforts have been devoted towards directly imaging phase transitions at microscopic scales. Here we show images of the charge-ordered insulator (COI) phase transition from a pure ferromagnetic metal with reducing field or increasing temperature in a strained phase-separated manganite film, using a home-built magnetic force microscope. Compared with the COI melting transition, this reverse transition is sharp, cooperative and martensitic-like with astonishingly unique yet diverse morphologies. The COI domains show variable-dimensional growth at different temperatures and their distribution can illustrate the delicate balance of the underlying interactions in manganites. Our findings also display how phase domain engineering is possible and how the phase competition can be tuned in a controllable manner.

  17. Morphological and functional platelet abnormalities in Berkeley sickle cell mice.

    PubMed

    Shet, Arun S; Hoffmann, Thomas J; Jirouskova, Marketa; Janczak, Christin A; Stevens, Jacqueline R M; Adamson, Adewole; Mohandas, Narla; Manci, Elizabeth A; Cynober, Therese; Coller, Barry S

    2008-01-01

    Berkeley sickle cell mice are used as animal models of human sickle cell disease but there are no reports of platelet studies in this model. Since humans with sickle cell disease have platelet abnormalities, we studied platelet morphology and function in Berkeley mice (SS). We observed elevated mean platelet forward angle light scatter (FSC) values (an indirect measure of platelet volume) in SS compared to wild type (WT) (37+/-3.2 vs. 27+/-1.4, mean+/-SD; p<0.001), in association with moderate thrombocytopenia (505+/-49 x 10(3)/microl vs. 1151+/-162 x 10(3)/microl; p<0.001). Despite having marked splenomegaly, SS mice had elevated levels of Howell-Jolly bodies and "pocked" erythrocytes (p<0.001 for both) suggesting splenic dysfunction. SS mice also had elevated numbers of thiazole orange positive platelets (5+/-1% vs. 1+/-1%; p<0.001), normal to low plasma thrombopoietin levels, normal plasma glycocalicin levels, normal levels of platelet recovery, and near normal platelet life spans. Platelets from SS mice bound more fibrinogen and antibody to P-selectin following activation with a threshold concentration of a protease activated receptor (PAR)-4 peptide compared to WT mice. Enlarged platelets are associated with a predisposition to arterial thrombosis in humans and some humans with SCD have been reported to have large platelets. Thus, additional studies are needed to assess whether large platelets contribute either to pulmonary hypertension or the large vessel arterial occlusion that produces stroke in some children with sickle cell disease.

  18. Description and Reconstruction of Soil Structure Using Correlation Functions: Morphological and Pore-Scale Modeling Study

    NASA Astrophysics Data System (ADS)

    Karsanina, M.; Gerke, K.; Vasilyev, R.; Skvortsova, E. B.; Korost, D. V.; Mallants, D.

    2013-12-01

    It is now well-established that structure of porous or composite media (i.e., distribution of different materials or phases) defines all physical properties, including multi-phase flow and solute transport. To characterize soil structure conventional soil science uses such metrics as grain size distribution, morphology or numerous classifications. However, all these descriptors provide only limited and often qualitative information about structural properties, cannot be used to reconstruct real structure or predict physical properties. With the progress of modern non-destructive analysis tools we can obtain detailed 3D structure information and use it for calculation of any physical property. Such 3D data is a valuable verification dataset to check the usefulness of soil structure description using stochastic measures such as correlation functions. Any potential soil structure descriptor should possess two main features: 1) represent structure in some mathematical way, 2) reconstruction based on this mathematical function alone should be statistically equal to the original structure (e.g., have similar pore size distributions, physical properties, etc.). To check the applicability to soil science, we choose different 2D and 3D segmented soil images and calculated their correlation function. The modified Yeong-Torquato procedure was then used to reconstruct images based on calculated correlation functions. This method was applied to three different soil datasets: 1) a set of 2D thin-sections, 2) 3D images of soils with known hydraulic properties (Ksat and WRC), 3) 3D images of soils and aggregates from the same soil profile, but different genetic horizons. In the first case, we use conventional morphological descriptors in 2D original and reconstructed images (pore size, shapes and orientations) to quantify reconstructions quality. In the second case, we use pore-network models extracted from original and reconstructed 3D images to calculate Ksat, WRC and relative

  19. Amelogenin Affects Brushite Crystal Morphology and Promotes Its Phase Transformation to Monetite

    SciTech Connect

    Ren, Dongni; Ruan, Qichao; Tao, Jinhui; Lo, Jonathan; Nutt, Steven; Moradian-Oldak, Janet

    2016-09-07

    Amelogenin protein is involved in organized apatite crystallization during enamel formation. Brushite (CaHPO4·2H2O), which is one of the precursors for hydroxyapatite in in vitro mineralization, has been used for fabrication of biomaterials for hard tissue repair. In order to explore its potential application in biomimetic material synthesis, we studied the influence of amelogenin on brushite morphology and phase transformation to monetite. Our results show that amelogenin can adsorb onto surface of brushite, leading to the formation of layered structures on the (010) face. Amelogenin promoted the phase transformation of brushite into monetite (CaHPO4) in the dry state, presumably by interacting with crystalline water layers in brushite unit cell. Changes to the crystal morphology by amelogenin continued even after the phase transformation to monetite forming an organized nanotextured structure of nano-sticks resembling the bundle structure in enamel.

  20. Phases of Polonium via Density Functional Theory

    NASA Astrophysics Data System (ADS)

    Verstraete, Matthieu J.

    2010-01-01

    The thermodynamical properties of the main phases of metallic polonium are examined using density functional theory. The exceptional nature of the solid-solid phase transition of α to β Po is underlined: it induces a lowering in symmetry, from cubic to rhombohedral, with increasing temperature. This is explained as the result of a delicate balance between bonding and entropic effects. Overall agreement with existing experimental data is good by state-of-the-art standards. The phonons of Po present Kohn anomalies, and it is shown that the effect of spin-orbit interactions is the inverse of that in normal metals: due to the nonspherical nature of the Fermi Surface, spin-orbit effects reduce nesting and harden most phonon frequencies.

  1. Effect of confinement and kinetics on the morphology of phase separating gelatin-maltodextrin droplets.

    PubMed

    Fransson, Sophia; Lorén, Niklas; Altskär, Annika; Hermansson, Anne-Marie

    2009-06-08

    The effect of confinement on the structure evolution and final morphology during phase separation and gelation of gelatin and maltodextrin was investigated and compared to the structures seen in bulk phase. Emulsion droplets with diameters from 4 to 300 mum were analyzed using confocal laser scanning microscopy and image analysis. With the confocal laser scanning microscope it was possible to follow the entire phase separating process inside the droplets in real-time. The samples were either quenched directly from 70 degrees C down to 20 degrees C or exposed to holding times at 40 degrees C. Different cooling procedures were studied to examine the structure evolution both before and after gelation in the restricted geometries. The concentration of the biopolymer mixture was kept constant at 4 w/w% gelatin and 6 w/w% maltodextrin. The results revealed that the size of the confinement had a great effect on both the initiation of phase separation and the final morphology of the microstructure inside the emulsion droplets. The phase separation in small droplets was observed to occur at a temperature above the phase separating temperature for bulk. Small droplets had either a microstructure with a shell of maltodextrin and core of gelatin or a microstructure where the two biopolymers had formed two separate bicontinuous halves. The initiation of phase separation in large droplets was similar to what was seen in bulk. The microstructure in large droplets was discontinuous, resembling the morphology in bulk phase. The kinetics had an effect on the character of the maltodextrin inclusions, as the cooling procedure of a direct quench gave spherical inclusions with an even size distribution, while a holding time at 40 degrees C resulted in asymmetrical and elongated inclusions.

  2. Morphology and phase controlled cobalt nanostructures in magnetic polypropylene nanocomposites: the role of alkyl chain-length in maleic anhydride grafted polypropylene.

    PubMed

    He, Qingliang; Yuan, Tingting; Luo, Zhiping; Haldolaarachchige, Neel; Young, David P; Wei, Suying; Guo, Zhanhu

    2013-04-04

    A novel function of maleic anhydride grafted polypropylene (PP) with different backbone chain-lengths was demonstrated, i.e., in controlling the cobalt morphologies (dispersed polyhedral vs. assembled chain nanostructure), crystalline structures (ε- vs. β-phase), and magnetic property (242 vs. 808 Oe) in the synthesized magnetic PP nanocomposites.

  3. Lung Metabolism, Function, and Morphology during Hyperoxic and Hyperbaric Exposure

    DTIC Science & Technology

    1983-01-01

    followed by a 30 min wash period resulted in total loss of phase I of the 5-HT dose - response curve . Partial loss of phase II was also observed and was... response curve to 5-HT in guinea-pig isolated pulmonary arteries exhibits two contractile phases (Fed. Proc. 41: 1649, 1982). The first phase (I) is blocked...deviation in post-capillary transit times was about 1.8 seconds. A. 2) ENHANCEMENT BY PHENTOLAMINE OF RESPONSES TO 5-HT AFTER TACHYPHYLAXIS. The dose

  4. Relationships between phase morphology and deformation mechanisms in polymer nanocomposite nanofibres prepared by an electrospinning process.

    PubMed

    Kim, G M; Lach, R; Michler, G H; Pötschke, P; Albrecht, K

    2006-02-28

    Relationships between phase morphology and mechanical deformation processes in various electrospun polymer nanocomposite nanofibres (PNCNFs) containing different types of one-, two- and three-dimensional nanofiller have been investigated by transmission electron microscopy using in situ tensile techniques. From the study of the phase structure of electrospun PNCNFs, two morphological standard types are classified for the analysis of deformation mechanisms: the binary system (polymer matrix and nanofillers), and the ternary system (polymer matrix, nanofillers and nanopores on the fibres surface). According to these categories, deformation processes have been characterized, and different schematic models for these processes are proposed. The finding of importance in the present work is a brittle-to-ductile transition in polymer nanocomposite fibres during in situ tensile deformation processes. This unique feature in the deformation behaviour of electrospun PNCNFs provides an optimal balance of stiffness, strength and toughness for use as reinforcing elements in a polymer based composite of a new kind.

  5. Surface Morphology and Structure of Double-Phase Magnetic Alkali Borosilicate Glasses

    NASA Astrophysics Data System (ADS)

    Andreeva, N. V.; Naberezhnov, A. A.; Tomkovich, M. V.; Nacke, B.; Kichigin, V.; Rudskoy, A. I.; Filimonov, A. V.

    2016-11-01

    The surface morphology of double-phase magnetic alkali borosilicate glasses of four types obtained by induction melting is studied by the methods of atomic-force and scanning electron microscopy. The distribution of elements over the surface and the elemental composition of the glasses are determined. It is shown that a dendritic system of interrelated channels required for formation of porous matrixes with controlled mean pore diameter may be obtained in these objects depending on the heat treatment mode.

  6. Change dynamics of RBC morphology after injection glucose for diabetes by diffraction phase microscope

    NASA Astrophysics Data System (ADS)

    Talaykova, N. A.; Kalyanov, A. L.; Lychagov, V. V.; Ryabukho, V. P.; Malinova, L. I.

    2013-11-01

    Experimental setup of diffraction phase microscope (DPM) with double low-coherence lighting system is presented in the paper. Algorithm of interference picture processing and optical thickness, height, volume and mean cells volume (MCV) of RBC calculating is shown. We demonstrate results of experiments with blood smears and ability of the method to calculate 3D model of the biological cells shape. Investigation change dynamics of RBC morphology after injection glucose for diabetes by DPM is shown in the paper.

  7. Nanomechanical morphology of amorphous, transition, and crystalline domains in phase change memory thin films

    NASA Astrophysics Data System (ADS)

    Bosse, J. L.; Grishin, I.; Huey, B. D.; Kolosov, O. V.

    2014-09-01

    In the search for phase change materials (PCM) that may rival traditional random access memory, a complete understanding of the amorphous to crystalline phase transition is required. For the well-known Ge2Sb2Te5 (GST) and GeTe (GT) chalcogenides, which display nucleation and growth dominated crystallization kinetics, respectively, this work explores the nanomechanical morphology of amorphous and crystalline phases in 50 nm thin films. Subjecting these PCM specimens to a lateral thermal gradient spanning the crystallization temperature allows for a detailed morphological investigation. Surface and depth-dependent analyses of the resulting amorphous, transition and crystalline regions are achieved with shallow angle cross-sections, uniquely implemented with beam exit Ar ion polishing. To resolve the distinct phases, ultrasonic force microscopy (UFM) with simultaneous topography is implemented revealing a relative stiffness contrast between the amorphous and crystalline phases of 14% for the free film surface and 20% for the cross-sectioned surface. Nucleation is observed to occur preferentially at the PCM-substrate and free film interface for both GST and GT, while fine subsurface structures are found to be sputtering direction dependent. Combining surface and cross-section nanomechanical mapping in this manner allows 3D analysis of microstructure and defects with nanoscale lateral and depth resolution, applicable to a wide range of materials characterization studies where the detection of subtle variations in elastic modulus or stiffness are required.

  8. Effects of monomer functionality on performances of scaffolding morphologic transmission gratings recorded in polymer dispersed liquid crystals

    NASA Astrophysics Data System (ADS)

    Huang, Wenbin; Pu, Donglin; Shen, Su; Wei, Guojun; Xuan, Li; Chen, Linsen

    2015-09-01

    The effects of monomer functionality on performances of holographic polymer dispersed liquid crystal (HPDLC) transmission gratings are systematically investigated. Acrylate monomers with an average functionality ranging from 2.0 to 5.0 are used to prepare these samples. We find scaffolding morphologic transmission gratings (characterized by a high phase separation degree, a well alignment of LCs and low scattering loss) can be obtained irrespective of the monomer functionality, although the exact optimal curing intensity varies. The temporal evolution of the grating formation is studied and the onset time of the LC phase separation decreases significantly with the increase in average monomer functionality. It is also shown that the gratings prepared from low average functionality monomers require a comparatively low switch-off electric field (~8 V μm-1) whilst suffering from mechanical fragility and long-term instability. Our results not only provide a complete understanding of scaffolding morphologic gratings in terms of the material composition effect, but also provide insight into the formation mechanisms of non-droplet morphologic HPDLC gratings.

  9. Functional Imaging of Tissue Morphology with Polarized Light Scattering Spectroscopy

    NASA Astrophysics Data System (ADS)

    Backman, Vadim

    2001-03-01

    We report a new imaging technique to study the morphology of living epithelial cells in vivo. The method is based on light scattering spectroscopy with polarized light (PLSS) and makes it possible to distinguish between single backscattering from epithelial cell nuclei and multiply scattered light. The spectrum of the single backscattering component is further analyzed to provide quantitative histological information about the epithelial cells such as the size distribution, refractive index, and chromatin content of the cell nuclei. The measurement of cell nuclear morphology is crucial for detection and diagnosis of cancerous and precancerous conditions in many human tissues. The method was successfully applied to image precancerous regions of several tissues. Clinical studies in five organs (esophagus, colon, bladder, oral cavity, and uterine cervix) showed the generality and efficacy of the technique.

  10. Morphological and functional diversity in therizinosaur claws and the implications for theropod claw evolution

    PubMed Central

    Lautenschlager, Stephan

    2014-01-01

    Therizinosaurs are a group of herbivorous theropod dinosaurs from the Cretaceous of North America and Asia, best known for their iconically large and elongate manual claws. However, among Therizinosauria, ungual morphology is highly variable, reflecting a general trend found in derived theropod dinosaurs (Maniraptoriformes). A combined approach of shape analysis to characterize changes in manual ungual morphology across theropods and finite-element analysis to assess the biomechanical properties of different ungual shapes in therizinosaurs reveals a functional diversity related to ungual morphology. While some therizinosaur taxa used their claws in a generalist fashion, other taxa were functionally adapted to use the claws as grasping hooks during foraging. Results further indicate that maniraptoriform dinosaurs deviated from the plesiomorphic theropod ungual morphology resulting in increased functional diversity. This trend parallels modifications of the cranial skeleton in derived theropods in response to dietary adaptation, suggesting that dietary diversification was a major driver for morphological and functional disparity in theropod evolution. PMID:24807260

  11. Systematic morphological profiling of human gene and allele function via Cell Painting.

    PubMed

    Rohban, Mohammad Hossein; Singh, Shantanu; Wu, Xiaoyun; Berthet, Julia B; Bray, Mark-Anthony; Shrestha, Yashaswi; Varelas, Xaralabos; Boehm, Jesse S; Carpenter, Anne E

    2017-03-18

    We hypothesized that human genes and disease-associated alleles might be systematically functionally annotated using morphological profiling of cDNA constructs, via a microscopy-based Cell Painting assay. Indeed, 50% of the 220 tested genes yielded detectable morphological profiles, which grouped into biologically meaningful gene clusters consistent with known functional annotation (e.g., the RAS-RAF-MEK-ERK cascade). We used novel subpopulation-based visualization methods to interpret the morphological changes for specific clusters. This unbiased morphologic map of gene function revealed TRAF2/c-REL negative regulation of YAP1/WWTR1-responsive pathways. We confirmed this discovery of functional connectivity between the NF-κB pathway and Hippo pathway effectors at the transcriptional level, thereby expanding knowledge of these two signaling pathways that critically regulate tumor initiation and progression. We make the images and raw data publicly available, providing an initial morphological map of major biological pathways for future study.

  12. Morphology predicts species' functional roles and their degree of specialization in plant–frugivore interactions

    PubMed Central

    Dehling, D. Matthias; Schaefer, H. Martin; Böhning-Gaese, Katrin; Schleuning, Matthias

    2016-01-01

    Species' functional roles in key ecosystem processes such as predation, pollination or seed dispersal are determined by the resource use of consumer species. An interaction between resource and consumer species usually requires trait matching (e.g. a congruence in the morphologies of interaction partners). Species' morphology should therefore determine species' functional roles in ecological processes mediated by mutualistic or antagonistic interactions. We tested this assumption for Neotropical plant–bird mutualisms. We used a new analytical framework that assesses a species's functional role based on the analysis of the traits of its interaction partners in a multidimensional trait space. We employed this framework to test (i) whether there is correspondence between the morphology of bird species and their functional roles and (ii) whether morphologically specialized birds fulfil specialized functional roles. We found that morphological differences between bird species reflected their functional differences: (i) bird species with different morphologies foraged on distinct sets of plant species and (ii) morphologically distinct bird species fulfilled specialized functional roles. These findings encourage further assessments of species' functional roles through the analysis of their interaction partners, and the proposed analytical framework facilitates a wide range of novel analyses for network and community ecology. PMID:26817779

  13. Sigma phase morphologies in cast and aged super duplex stainless steel

    SciTech Connect

    Martins, Marcelo; Casteletti, Luiz Carlos

    2009-08-15

    Solution annealed and water quenched duplex and super duplex stainless steels are thermodynamically metastable systems at room temperature. These systems do not migrate spontaneously to a thermodynamically stable condition because an energy barrier separates the metastable and stable states. However, any heat input they receive, for example through isothermal treatment or through prolonged exposure to a voltaic arc in the welding process, cause them to reach a condition of stable equilibrium which, for super duplex stainless steels, means precipitation of intermetallic and carbide phases. These phases include the sigma phase, which is easily identified from its morphology, and its influence on the material's impact strength. The purpose of this work was to ascertain how 2-hour isothermal heat treatments at 920 deg. C and 980 deg. C affect the microstructure of ASTM A890/A890M GR 6A super duplex stainless steel. The sigma phase morphologies were found to be influenced by these two aging temperatures, with the material showing a predominantly lacy microstructure when heat treated at 920 deg. C and block-shaped when heat treated at 980 deg. C.

  14. Fluorescence-Magnetism Functional EuS Nanocrystals with Controllable Morphologies for Dual Bioimaging.

    PubMed

    Sun, Yuanqing; Wang, Dandan; Zhao, Tianxin; Jiang, Yingnan; Zhao, Yueqi; Wang, Chuanxi; Sun, Hongchen; Yang, Bai; Lin, Quan

    2016-12-14

    Multiple functions incorporated in one single component material offer important applications in biosystems. Here we prepared a divalent state of rare earth EuS nanocrystals (NCs), which provides luminescent and magnetic properties, using both 1-Dodecanethiol (DT) and oleylamine (OLA) as reducing agents. The resultant EuS NCs exhibit controllable shapes, uniform size, and bright luminescence with a quantum yield as high as 3.5%. OLA as a surface ligand plays an important role in tunable morphologies, such as nanowires, nanorods, nanospheres et al. Another attractive nature of the EuS NCs is their paramagnetism at room temperature. In order to expand the biological applications, the resultant EuS NCs were modified with amphiphilic block copolymer F127 and transferred from oil to water phase. The excellent biocompatibility of EuS NCs is demonstrated as well as preservation of their luminescence and paramagnetic properties. The EuS NCs offer multifunction and great advantages of bright luminescence, paramagnetic, controllable morphologies, and good biocompatibility promising applications in the field of simultaneous magnetic resonance and fluorescence bioimaging.

  15. Morphology and crystalline-phase-dependent electrical insulating properties in tailored polypropylene for HVDC cables

    NASA Astrophysics Data System (ADS)

    Zha, Jun-Wei; Yan, Hong-Da; Li, Wei-Kang; Dang, Zhi-Min

    2016-11-01

    Polypropylene (PP) has become one promising material to potentially replace the cross-link polyethylene used for high voltage direct current cables. Besides the isotactic polypropylene, the block polypropylene (b-PP) and random polypropylene (r-PP) can be synthesized through the copolymerization of ethylene and propylene molecules. In this letter, the effect of morphology and crystalline phases on the insulating electrical properties of PP was investigated. It was found that the introduction of polyethylene monomer resulted in the formation of β and γ phases in b-PP and r-PP. The results from the characteristic trap energy levels indicated that the β and γ phases could induce deep electron traps which enable to capture the carriers. And the space charge accumulation was obviously suppressed. Besides, the decreased electrical conductivity was observed in b-PP and r-PP. It is attributed to the existence of deep traps which can effectively reduce the carrier mobility and density in materials.

  16. Morphological instability of Ag films caused by phase transition in the underlying Ta barrier layer

    SciTech Connect

    Mardani, Shabnam Vallin, Örjan; Wätjen, Jörn Timo; Norström, Hans; Olsson, Jörgen; Zhang, Shi-Li

    2014-08-18

    Wide-bandgap (WBG) semiconductor technologies are maturing and may provide increased device performance in many fields of applications, such as high-temperature electronics. However, there are still issues regarding the stability and reliability of WBG devices. Of particular importance is the high-temperature stability of interconnects for electronic systems based on WBG-semiconductors. For metallization without proper encapsulation, morphological degradation can occur at elevated temperatures. Sandwiching Ag films between Ta and/or TaN layers in this study is found to be electrically and morphologically stabilize the Ag metallization up to 800 °C, compared to 600 °C for uncapped films. However, the barrier layer plays a key role and TaN is found to be superior to Ta, resulting in the best achieved stability, whereas the difference between Ta and TaN caps is negligible. The β-to-α phase transition in the underlying Ta barrier layer is identified as the major cause responsible for the morphological instability observed above 600 °C. It is shown that this phase transition can be avoided using a stacked Ta/TaN barrier.

  17. Phase-field simulations of coherent precipitate morphologies and coarsening kinetics

    NASA Astrophysics Data System (ADS)

    Vaithyanathan, Venugopalan

    2002-09-01

    The primary aim of this research is to enhance the fundamental understanding of coherent precipitation reactions in advanced metallic alloys. The emphasis is on a particular class of precipitation reactions which result in ordered intermetallic precipitates embedded in a disordered matrix. These precipitation reactions underlie the development of high-temperature Ni-base superalloys and ultra-light aluminum alloys. Phase-field approach, which has emerged as the method of choice for modeling microstructure evolution, is employed for this research with the focus on factors that control the precipitate morphologies and coarsening kinetics, such as precipitate volume fractions and lattice mismatch between precipitates and matrix. Two types of alloy systems are considered. The first involves L1 2 ordered precipitates in a disordered cubic matrix, in an attempt to model the gamma' precipitates in Ni-base superalloys and delta' precipitates in Al-Li alloys. The effect of volume fraction on coarsening kinetics of gamma' precipitates was investigated using two-dimensional (2D) computer simulations. With increase in volume fraction, larger fractions of precipitates were found to have smaller aspect ratios in the late stages of coarsening, and the precipitate size distributions became wider and more positively skewed. The most interesting result was associated with the effect of volume fraction on the coarsening rate constant. Coarsening rate constant as a function of volume fraction extracted from the cubic growth law of average half-edge length was found to exhibit three distinct regimes: anomalous behavior or decreasing rate constant with volume fraction at small volume fractions ( ≲ 20%), volume fraction independent or constant behavior for intermediate volume fractions (˜20--50%), and the normal behavior or increasing rate constant with volume fraction for large volume fractions ( ≳ 50%). The second alloy system considered was Al-Cu with the focus on understanding

  18. Cells with dendritic cell morphology and immunophenotype, binuclear morphology, and immunosuppressive function in dendritic cell cultures.

    PubMed

    Dong, Rong; Moulding, Dale; Himoudi, Nourredine; Adams, Stuart; Bouma, Gerben; Eddaoudi, Ayad; Basu, B Piku; Derniame, Sophie; Chana, Prabhjoat; Duncan, Andrew; Anderson, John

    2011-01-01

    Culturing of human peripheral blood CD14 positive monocytes is a method for generation of dendritic cells (DCs) for experimental purposes or for use in clinical grade vaccines. When culturing human DCs in this manner for clinical vaccine production, we noticed that 5-10% of cells within the bulk culture were binuclear or multiple nuclear, but had typical dendritic cell morphology and immunophenotype. We refer to the cells as binuclear cells in dendritic cell cultures (BNiDCs). By using single cell PCR analysis of mitochondrial DNA polymorphisms we demonstrated that approximately 20-25% of cells in DC culture undergo a fusion event. Flow sorted BNiDC express low HLA-DR and IL-12p70, but high levels of IL-10. In mixed lymphocyte reactions, purified BNiDC suppressed lymphocyte proliferation. Blockade of dendritic cell-specific transmembrane protein (DC-STAMP) decreased the number of binuclear cells in DC cultures. BNiDC represent a potentially tolerogenic population within DC preparations for clinical use.

  19. Effect of chain extender on the phase behavior and morphology of high hard block content polyurethanes

    NASA Astrophysics Data System (ADS)

    Tsiotas, Achilleas; Lindsay, Chris; Saiani, Alberto

    2010-03-01

    Thermoplastic polyurethanes (TPUs) are linear block copolymers typically constructed of statistically alternating soft and hard segments, the hard segment itself being composed of an isocyanate and a short chain extender. In this project we focused on the effect that varying the chain extender used has on the phase behavior and morphology of high hard block content TPUs. Four different chain extenders were used. DSC, SAXS / WAXS, TEM / AFM, mechanical testing and FTIR were mainly used to characterize the morphology and properties of our materials. Through this work we were able to show that small changes in the chain extender chemical structure had dramatic effects on the properties of the TPUs. The use of 3-methyl-1,5-pentanediol resulted in a fully phase-mixed system with poor mechanical properties, while the use of 1,3-propanediol resulted in stiff materials with relatively high crystallinity and melting temperature. The use of 2-methyl-1,3-propanediol and 1,5-pentanediol resulted in similar materials, although 1,5-pentanediol was found to phase separate / crystallize on cooling while 2-methyl-1,3-propanediol was found to separate / crystallize on heating, suggesting a higher chain mobility in the latter materials.

  20. Morphology and Magnetic Properties of Ferriferous Two-Phase Sodium Borosilicate Glasses

    PubMed Central

    Naberezhnov, Alexander; Porechnaya, Nadezda; Nizhankovskii, Viktor; Filimonov, Alexey; Nacke, Bernard

    2014-01-01

    This contribution is devoted to the study of morphology and magnetic properties of sodium borosilicate glasses with different concentrations (15, 20, and 25 wt.%) of α-Fe2O3 in an initial furnace charge. These glasses were prepared by a melt-quenching method. For all glasses a coexistence of drop-like and two-phase interpenetrative structures is observed. The most part of a drop structure is formed by self-assembling iron oxides particles. All types of glasses demonstrate the magnetic properties and can be used for preparation of porous magnetic matrices with nanometer through dendrite channel structure. PMID:25162045

  1. Simultaneous phase and morphology controllable synthesis of copper selenide films by microwave-assisted nonaqueous approach

    NASA Astrophysics Data System (ADS)

    Li, Jing; Fa, Wenjun; Li, Yasi; Zhao, Hongxiao; Gao, Yuanhao; Zheng, Zhi

    2013-02-01

    Copper selenide films with different phase and morphology were synthesized on copper substrate through controlling reaction solvent by microwave-assisted nonaqueous approach. The films were characterized by X-ray diffraction (XRD) and scanning electron microscope (SEM). The result showed that the pure films could be obtained using cyclohexyl alcohol or benzyl alcohol as solvent. The cubic Cu2-xSe dendrites were synthesized in cyclohexyl alcohol reaction system and hexagonal CuSe flaky crystals were obtained with benzyl alcohol as solvent.

  2. Phase morphology and orientation development of polymer blends in melt processing

    NASA Astrophysics Data System (ADS)

    Yang, Jinhai

    In this dissertation, we studied phase morphology development of various polymer blends in both extrusion and melt spinning using scanning electron microscopy (SEM) assisted with appropriate etching techniques. Various processing conditions, for example shear or elongation rate, shear or elongation stress, and extrusion die length/diameter ratio were considered. The effects of material characteristics, such as viscosity ratio, miscibility and interfacial tension, were studied. To do this, polymer blends were carefully selected. One isotactic polypropylene was blended with two ethylene butene copolymers (EBM), which had different butene contents. One of the blends was miscible and the other was immiscible. The polypropylene was also blended two ethylene octene copolymers (EOM). The above blends had low interfacial tension and different viscosity ratios. One EBM was blended with two polyamide 12 (PA12) materials. These blends had high interfacial tension and different viscosity ratios. One maleic anhydride grafted ethylene octene copolymer was added into the EBM/PA12 blends to decrease their interfacial tension. Studies were focused on a phenomenon that the dispersed phases in these blends could coalesce into a surface layer in both extrusion and melt spinning. This process was controlled by viscosity ratio, interfacial tension and processing conditions. The orientation development of melt spun fibers of these blends was studied by both wide angle X-ray diffraction (WAXD) and birefringence techniques. The orientation was affected by both blend morphologies and solidification order of the blend individual phases. The phase, which solidifies later in the spinline, did not affect the orientation of the first solidified phase. However, the first solidified phase, if it was continuous phase, could largely suppress the orientation of the second solidified phase. Composite stress analysis explained the different orientation behaviors. Extrusion of a PA12 material through a

  3. Functional morphology of the tongue in the nutcracker (Nucifraga caryocatactes).

    PubMed

    Jackowiak, Hanna; Skieresz-Szewczyk, Kinga; Kwieciński, Zbigniew; Trzcielińska-Lorych, Joanna; Godynicki, Szymon

    2010-07-01

    The nutcracker Nucifraga caryocatactes belongs to a group of bird species that use their beak and tongue as tools for obtaining food, such as seeds from hard-to-reach cones or nuts from shells. The aim of the present study, carried out with a scanning electron microscope, was to define the morphological features of the tongue of the nutcracker, which seems to be adapted to its environment through specific methods of obtaining food. One of the characteristic features of the nutcracker's tongue is the unique structure of the anterior part of the tongue, which has two long and highly keratinized processes - a product of the renewable keratinized layer of the epithelium covering the ventral surface of the tongue. These dagger-like processes, which are a modified "lingual nail," take a major role in levering up and shelling seeds, which are transported over the short sulcus-shaped body of the tongue. A unique feature of the nutcracker's tongue is the groove separating the body from the root. Two rows of highly keratinized, mechanical, conical papillae are located at the junction of the body and the root. These papillae are mechanically protective elements for passing food particles in the form of seeds. Among lingual glands, only the posterior lingual glands on the root of the tongue have been observed. Their secretion agglutinates dry food before it is swallowed. Results of the present study indicate that the nutcracker's tongue is an efficient tool resembling a lever that is helpful in shelling seeds.

  4. Functional morphology of the nasal region of a hammerhead shark.

    PubMed

    Abel, Richard L; Maclaine, James S; Cotton, Ross; Xuan, Viet Bui; Nickels, Timothy B; Clark, Thomas H; Wang, Zhijin; Cox, Jonathan P L

    2010-04-01

    We describe several novel morphological features in the nasal region of the hammerhead shark Sphyrna tudes. Unlike the open, rounded incurrent nostril of non-hammerhead shark species, the incurrent nostril of S. tudes is a thin keyhole-like aperture. We discovered a groove running anterior and parallel to the incurrent nostril. This groove, dubbed the minor nasal groove to distinguish it from the larger, previously described, (major) nasal groove, is common to all eight hammerhead species. Using life-sized plastic models generated at 200 microm resolution from an X-ray scan, we also investigated flow in the nasal region. Even modest oncoming flow speeds stimulate extensive, but not complete, circulation within the model olfactory chamber, with flow passing through the two main olfactory channels. Flow crossed from one channel to another via a gap in the olfactory array, sometimes guided by the interlamellar channels. Major and minor nasal grooves, as well as directing flow into the olfactory chamber, can, in conjunction with the nasal bridge separating incurrent and excurrent nostrils, limit flow passing into the olfactory chamber, possibly to protect the delicate nasal structures. This is the first simulation of internal flow within the olfactory chamber of a shark.

  5. Quantification of texture match of the skin graft: function and morphology of the stratum corneum.

    PubMed

    Inoue, K; Matsumoto, K

    1986-01-01

    In an attempt to analyze the "texture match" of grafted skin, functional and morphological aspects of the stratum corneum were studied using the Skin Surface Hydrometer (IBS Inc.) and the scanning electron microscope. The results showed that hygroscopicity and water holding capacity of the stratum corneum played a crucial role in making the skin surface soft and smooth. Morphologically there were regional differences in the surface pattern and the mean area of corneocytes, suggesting that these differences affect skin texture. It is suggested that the present functional and morphological studies of the stratum corneum can provide a quantitative measure of the "texture match".

  6. Efficient reconstruction of multiphase morphologies from correlation functions

    SciTech Connect

    Rozman, M. G.; Utz, Marcel

    2001-06-01

    A highly efficient algorithm for the reconstruction of microstructures of heterogeneous media from spatial correlation functions is presented. Since many experimental techniques yield two-point correlation functions, the restoration of heterogeneous structures, such as composites, porous materials, microemulsions, ceramics, or polymer blends, is an inverse problem of fundamental importance. Similar to previously proposed algorithms, the new method relies on Monte Carlo optimization, representing the microstructure on a discrete grid. An efficient way to update the correlation functions after local changes to the structure is introduced. In addition, the rate of convergence is substantially enhanced by selective Monte Carlo moves at interfaces. Speedups over prior methods of more than two orders of magnitude are thus achieved. Moreover, an improved minimization protocol leads to additional gains. The algorithm is ideally suited for implementation on parallel computers. The increase in efficiency brings new classes of problems within the realm of the tractable, notably those involving several different structural length scales and/or components.

  7. Matching ecological functioning with polychaete morphology: Consistency patterns along sedimentary habitats

    NASA Astrophysics Data System (ADS)

    Otegui, Mariana B. P.; Brauko, Kalina M.; Pagliosa, Paulo R.

    2016-08-01

    The relationship between form and function is usually evident and reflect causal relationships in ecological interactions. However, the consistency of the taxonomical and functional approaches versus a morphological approach is yet to be assessed and applied to benthic-sediment relationships. Here, we propose a new functional classification based on morphological characteristics using polychaetes. To test the validity of the framework we assess the consistency between polychaete responses to distinct sedimentary environments using morphological, taxonomical and biological traits approaches, and comparing the patterns of polychaete responses at local and regional scales. The selected morphological characteristics were pharynx complexity, jaws presence, feeding palps, head appendages, body appendages, body support structures, branchiae and body regionalization, as well as number of segments, which were categorized according to presence, size, number or type of structure. The novel morphological method was successfully applied and all analyses showed consistent faunal patterns of variation along muddy and sandy habitats at the distinct spatial scales. Nevertheless, in the three case studies the morphological method explained more over the general variability and was more concise than the other two methods, emphasizing the reliability of a functional approach. The distinct set of morphological characteristics found in muddy and sandy habitats reflected two different ecological roles of polychaetes. Discretely motile, small sized and of low sensibility polychaetes prevailed in muddy habitats, while sandy sediments were dominated by organisms with richer and more heterogeneous characteristics. The responses of the morphological analysis were very similar to the taxonomical and biological traits analysis, but with a much higher explanatory power, meaning that morphology provides a robust approach for studying the ecological functionality of marine benthic systems.

  8. Comparative and functional morphology of wing coupling structures in Trichoptera: Annulipalpia.

    PubMed

    Stocks, Ian C

    2010-02-01

    Several orders of morphologically four-winged insects have evolved mechanisms that enforce a union between the mesothoracic and metathoracic wings (forewings and hindwings) during the wing beat cycle. Such mechanisms result in a morphologically tetrapterous insect flying as if it were functionally dipterous, and these mechanisms have been described for several insect orders. The caddisfly suborders Annulipalpia and Integripalpia (Trichoptera) each have evolved a wing coupling apparatus, with at least three systems having evolved within the suborder Annulipalpia. The comparative and inferred functional morphology of the putative wing coupling mechanisms is described for the annulipalpian families Hydropsychidae (subfamilies Macronematinae and Hydropsychinae), Polycentropodidae and Ecnomidae, and a novel form-functional complex putatively involved with at-rest forewing-forewing coupling is described for Hydropsychidae: Smicrideinae. It is proposed that the morphology of the wing coupling apparatuses of Hydropsychinae and Macronematinae are apomorphies for those clades.

  9. Morphology, structure and electrochemical properties of single phase electrospun vanadium pentoxide nanofibers for lithium ion batteries

    NASA Astrophysics Data System (ADS)

    Cheah, Yan L.; Gupta, Nutan; Pramana, Stevin S.; Aravindan, Vanchiappan; Wee, Grace; Srinivasan, Madhavi

    2011-08-01

    One-dimensional (1D) vanadium pentoxide (V2O5) nanofibers (VNF) are synthesized by electrospinning vanadium sol-gel precursors containing vanadyl acetylacetonate and poly(vinylpyrrolidone) followed by sintering. Crystal structure, molecular structure and morphology of electrospun VNF are analyzed using field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), selected area diffraction (SAED), X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FT-IR). Single-phase electrospun VNF ∼300-800 nm in diameter, 20-50 μm long (aspect ratio > 50) with porous interconnected fibrous morphology are revealed by FESEM and TEM analysis. Electrochemical properties of the sintered VNF, as a cathode in lithium-ion batteries, explored using cyclic voltammetry (CV), galvanostatic charge/discharge and electrochemical impedance spectroscopy (EIS) give rise to new understandings of the electrochemical processes occurring in these nanofibrous cathodes. Electrospun VNF exhibits initial discharge capacity ∼316 mAh g-1 (∼2.2 Li per V2O5) in the voltage range of 1.75 and 4.0 V vs. Li/Li+ at 0.1 C rate. When cycled at a reduced voltage range of 2.0-4.0 V vs. Li/Li+, less phase transitions occur, giving rise to the initial specific capacity of 308 mAh g-1 and improved cyclic retention of 74% after 50 cycles.

  10. Ontogenetic shifts in functional morphology of dragonfly legs (Odonata: Anisoptera).

    PubMed

    Leipelt, Klaus Guido; Suhling, Frank; Gorb, Stanislav N

    2010-12-01

    Anisopteran leg functions change dramatically from the final larval stadium to the adult. Larvae use legs mainly for locomotion, walking, climbing, clinging, or burrowing. Adults use them for foraging and grasping mates, for perching, clinging to the vegetation, and for repelling rivals. In order to estimate the ontogenetic shift in the leg construction from the larva to the adult, this study quantitatively compared lengths of fore, mid, and hind legs and the relationships between three leg segments, femur, tibia, and tarsus, in larval and adult Anisoptera of the families Gomphidae, Aeshnidae, Cordulegastridae, Corduliidae, and Libellulidae, represented by two species each. We found that leg segment length ratio as well as ontogenetic shift in length ratios was different between families, but rather similar within the families. While little ontogenetic shift occurred in Aeshnidae, there were some modifications in Corduliidae and Libellulidae. The severest shift occurred in Gomphidae and Cordulegastridae, both having burrowing larvae. These two families form a cluster, which is in contrast to their taxonomic relationship within the Anisoptera. Cluster analysis implies that the function of larval legs is primarily responsible for grouping, whereas adult behavior or the taxonomic relationships do not explain the grouping. This result supports the previous hypothesis about the convergent functional shift of leg characters in the dragonfly ontogenesis.

  11. The relationship between oxygen permeability and phase separation morphology of the multicomponent silicone hydrogels.

    PubMed

    Zhao, Zhengbai; Xie, Haijiao; An, Shuangshuang; Jiang, Yong

    2014-12-18

    In this article, the multicomponent copolymers were prepared by the copolymerization of two hydrophobic silicon-containing monomers bis(trimethylsilyloxy) methylsilylpropyl glycerol methacrylate (SiMA) and tris(trimethylsiloxy)-3-methacryloxypropylsilane (TRIS) with three hydrophilic monomers 2-hydroxyethyl methacrylate, N-vinylpyrrolidone, and N,N-dimethyl acrylamide. The copolymers were hydrated to form transparent silicone hydrogels. The oxygen permeability coefficients (Dk) of hydrogels were measured, and their relationships with the equilibrium water contents (EWC) and the types and contents of silicon containing monomers as well as the phase separation structures of silicone hydrogels were analyzed in detail. The results showed that the EWC decreased as the increase of SiMA content. The relationship between Dk and SiMA content, as well as that between Dk and EWC, showed inverted bell curve distributions, which meant two main factors, i.e., silicon-oxygen bond in silicone and water in hydrogel, contributed to oxygen permeation and followed a mutual inhibition competition mechanism. The internal morphologies of the hydrogels were observed by transmission electron microscope, and the results showed that the hydrogels presented two different phase separation structures depending on the types of the silicon-containing monomers. The silicone phase in SiMA containing hydrogel presented to be a granular texture, while the silicone phase in TRIS containing hydrogel formed a fibrous texture which resulted in a higher Dk value. These results could help to design a silicone hydrogel with better properties and wider application.

  12. Oil and air dispersion in a simulated fermentation broth as a function of mycelial morphology.

    PubMed

    Lucatero, Savidra; Larralde-Corona, Claudia Patricia; Corkidi, Gabriel; Galindo, Enrique

    2003-01-01

    The culture conditions of a multiphase fermentation involving morphologically complex mycelia were simulated in order to investigate the influence of mycelial morphology (Trichoderma harzianum) on castor oil and air dispersion. Measurements of oil drops and air bubbles were obtained using an image analysis system coupled to a mixing tank. Complex interactions of the phases involved could be clearly observed. The Sauter diameter and the size distributions of drops and bubbles were affected by the morphological type of biomass (pellets or dispersed mycelia) added to the system. Larger oil drop sizes were obtained with dispersed mycelia than with pellets, as a result of the high apparent viscosity of the broth, which caused a drop in the power drawn, reducing oil drop break-up. Unexpectedly, bubble sizes observed with dispersed mycelia were smaller than with pellets, a phenomenon which can be explained by the segregation occurring at high biomass concentrations with the dispersed mycelia. Very complex oil drops were produced, containing air bubbles and a high number of structures likely consisting of small water droplets. Bubble location was influenced by biomass morphology. The percentage (in volume) of oil-trapped bubbles increased (from 32 to 80%) as dispersed mycelia concentration increased. A practically constant (32%) percentage of oil-trapped bubbles was observed with pelleted morphology at all biomass concentrations. The results evidenced the high complexity of phases interactions and the importance of mycelial morphology in such processes.

  13. Influence of thermal effects on the morphological patterns developed through phase separation in binary systems

    NASA Astrophysics Data System (ADS)

    Borzacchiello, D.; Leygue, A.; Chinesta, F.

    2014-07-01

    This paper is concerned with the modelling and numerical simulation of temperature-induced phase separation (TIPS) coupled with non-uniform temperature fields. The spontaneous phase separation of an initially homogeneous blend can be used, in principle, as a reliable and scalable process to reproduce specific morphologies at the microscopic scale in two-phase composite materials, such as rubber-reinforced resins, or in microstructured porous media. The size of the microstructures that are formed and the degree of anisotropy can be controlled through the imposition of an adequate temperature field. In order to understand the potential use of a temperature gradient to control phase separation, we developed a qualitative model for TIPS based on the Cahn-Hilliard approach and we proposed a computational strategy to obtain numerical solutions for phase separation in confined domains taking into account the thermal interaction with the walls. While the method is based on a volume penalization technique, the novelty of the proposed approach relies on the fact that the penalization term of the equation is constructed on the same theoretical basis from which the Cahn-Hilliard equation is derived. The advantage offered by this technique is that the same pseudo-spectral Fourier discretization schemes that are classically used to solve the Cahn-Hilliard equation in periodic domains can be straightforwardly applied to the case of bounded domains. The application examples shown in this paper emphasize the key role of the dimensionless number given by the ratio of the characteristic heat propagation time and the characteristic time of the phase separation, and demonstrate how control of the microstructure anisotropy could be achieved through TIPS.

  14. Morphogenesis and morphology of HIV. Structure-function relations.

    PubMed

    Gelderblom, H R; Ozel, M; Pauli, G

    1989-01-01

    Fine structure and antigenic make-up analysis of HIV were combined in a 2D model, from which functional aspects can be deduced. On the envelope 72 probably trimeric surface knobs (gp120) are connected to the virion via the transmembrane protein gp41. Gp120 is shed during ageing of the virion, but host cell antigens stay firmly anchored to the envelope. Underneath the envelope, p17 forms the matrix protein layer, while the capsid of the double cone shaped core is built up of p24. The relation between biochemical findings and morphogenesis and maturation of HIV as well as aspects of pathogenesis and vaccination are discussed.

  15. Modeling scattering in turbid media using the Gegenbauer phase function

    NASA Astrophysics Data System (ADS)

    Calabro, Katherine W.; Cassarly, William

    2015-03-01

    The choice of scattering phase function is critically important in the modeling of photon propagation in turbid media, particularly when the scattering path within the material is on the order of several mean free path lengths. For tissue applications, the single parameter Henyey-Greenstein (HG) phase function is known to underestimate the contribution of backscattering, while phase functions based on Mie theory can be more complex than necessary due to the multitude of parameter inputs. In this work, the two term Gegenbauer phase function is highlighted as an effective compromise between HG and Mie, as demonstrated when fitting the various phase function to measured data from phantom materials. Further comparison against the Modified Henyey-Greenstein (MHG) phase function, another two term function, demonstrates that the Gegenbauer function provides better control of the higher order phase function moments, and hence allows for a wider range of values for the similarity parameter, γ. Wavelength dependence of the Gegenbauer parameters is also investigated using a range of theoretical particle distributions. Finally, extraction of the scattering properties of solid turbid samples from angularly resolved transmission measurements is performed using an iterative Monte Carlo optimization technique. Fitting results using Gegenbauer, HG, MHG, and Mie phase functions are compared.

  16. Functional and morphologic damage in the neonatally irradiated canine kidney

    SciTech Connect

    Peneyra, R.S.; Jaenke, R.S.

    1985-11-01

    Perinatal irradiation of the developing kidney results in progressive glomerulosclerosis (PGS) and renal failure. This syndrome may result from direct radiation damage to mature deep cortical nephrons and/or nephron functional adaptations resulting from outer cortical nephron ablation. Beagle dogs received single, whole-body exposures (330 R) to /sup 60/Co gamma radiation at 4 days of age (IR4) to study the combined effects of direct radiation damage and nephron loss, or at 30 days of age (IR30) to study the effects of renal irradiation alone. To study the effects of nephron loss alone, dogs underwent unilateral nephrectomy (UN4) or superficial hyperthermic renal ablation (HY4) at 4 days of age. Nephron loss due to irradiation (IR4) and partial renal ablation (UN4 and HY4) was associated with compensatory nephron hypertrophy and increased single nephron glomerular filtration rate (SNGFR), while irradiation at 30 days resulted in transitory decreased SNGFR. Similar degrees of PGS occurred in IR4 dogs which experienced both irradiation and loss of nephrons and UN4 and HY4 dogs which experienced only loss of nephrons. PGS of lesser severity also occurred in IR30 dogs. These findings indicate that PGS associated with perinatal renal irradiation results from direct radiation damage to deep cortical nephrons and compensatory functional changes occurring in response to loss of renal mass.

  17. Glucose Tightly Controls Morphological and Functional Properties of Astrocytes

    PubMed Central

    Lee, Chun-Yao; Dallérac, Glenn; Ezan, Pascal; Anderova, Miroslava; Rouach, Nathalie

    2016-01-01

    The main energy source powering the brain is glucose. Strong energy needs of our nervous system are fulfilled by conveying this essential metabolite through blood via an extensive vascular network. Glucose then reaches brain tissues by cell uptake, diffusion and metabolization, processes primarily undertaken by astrocytes. Deprivation of glucose can however occur in various circumstances. In particular, ageing is associated with cognitive disturbances that are partly attributable to metabolic deficiency leading to brain glycopenia. Despite the crucial role of glucose and its metabolites in sustaining neuronal activity, little is known about its moment-to-moment contribution to astroglial physiology. We thus here investigated the early structural and functional alterations induced in astrocytes by a transient metabolic challenge consisting in glucose deprivation. Electrophysiological recordings of hippocampal astroglial cells of the stratum radiatum in situ revealed that shortage of glucose specifically increases astrocyte membrane capacitance, whilst it has no impact on other passive membrane properties. Consistent with this change, morphometric analysis unraveled a prompt increase in astrocyte volume upon glucose deprivation. Furthermore, characteristic functional properties of astrocytes are also affected by transient glucose deficiency. We indeed found that glucoprivation decreases their gap junction-mediated coupling, while it progressively and reversibly increases their intracellular calcium levels during the slow depression of synaptic transmission occurring simultaneously, as assessed by dual electrophysiological and calcium imaging recordings. Together, these data indicate that astrocytes rapidly respond to metabolic dysfunctions, and are therefore central to the neuroglial dialog at play in brain adaptation to glycopenia. PMID:27148048

  18. Modeling particle growth and morphology of impact polypropylene produced in the gas phase

    NASA Astrophysics Data System (ADS)

    Debling, Jon A.

    A gas phase reactor system using on-line FTIR for controlled composition olefin polymerization experiments with gaseous or liquid monomers has been designed and constructed in this work. Using this equipment, a comprehensive study of the kinetics, particle growth and morphological development of impact polypropylene produced in-situ with a TiClsb4/MgClsb2 catalyst has been conducted. The catalyst was found exhibiting a decay type behavior for ethylene and propylene homopolymerization but an activation effect was observed when both monomers were present together. Hydrogen was also seen to boost the rate of propylene polymerization but not ethylene, and increased the rate of catalyst deactivation during propylene polymerization. Microscopy analysis of the particles over a range of copolymer content (up to 70 wt. %), copolymer composition, reaction temperature and hydrogen levels reveal how the copolymer phase segregates from the homopolymer and grows within the homopolymer matrix. A model for particle growth is proposed. A computer model for the study of the effects of changing morphology for polyolefins produced in multistage processes has been developed and used to investigate the role of monomer diffusion limitations during polymerization using the experimental data found in this work. To study the effects of residence time distribution in multistage continuous processes for impact polypropylene, population balance models have been developed for multistage processes consisting of gas and liquid phase reactors. The effects of catalyst size distribution and monomer diffusion limitations can be incorporated into the models. It is shown that commercial impact polypropylene consists of a broad distribution of polymer properties as a consequence of reactor residence time distribution issues. Implications for product homogeneity, particle sticking and process productivity are discussed.

  19. [Microtubules in the nerve cells: morphological and functional aspects].

    PubMed

    Vorob'ev, V S; Portuganov, V V

    1980-10-01

    The modern literature concerning ultrastructure and cytochemistry of microtubules in the nervous tissue is reviewed. Common features of cytological and biochemical organization of microtubules in different parts of the nervous system of the vertebrates and invertebrates are analysed: the similarity of ultrastructure of microtubules and their molecular organization (tubulin and its alpha- and beta-monomeres), the ability of microtubules to assemble and disassemble, to bind specifically with poisons--colchicine and vinblastine, participation of microtubules in the neuroplastic transport. The authors' data on space arrangement of microtubules within cytoplasm of the neuronal processes (dendrites and unmyelinated axons in the central and peripheral nevous system) are presented. Some literature and personal results concerning ultrastructure of neurofilaments and microtubules in the myelinated nerve fibres are also considered. The functional significance of microtubules in the nervous system is discussed with special reference to facts and hypotheses on a possible role of microtubules in the propagation of nerve impulse.

  20. Morphological and functional effects of induced laser retinal fibrosis

    NASA Astrophysics Data System (ADS)

    Zwick, Harry; Schuschereba, Steven T.; Gagliano, Donald A.; Silverman, M.; Lund, David J.; Reynolds, Scottie B.; Stuck, Bruce E.

    1994-02-01

    Human laser accident exposure cases may involve severe macula retinal injury resulting in long term visual acuity and spatial vision deficit. In order to investigate this problem, we have chosen to model the effects of such long term exposure in the monkey retina for parafoveal Q- switched exposure produced at two parafoveal exposure sites. Our results suggest significant loss of retinal function in and adjacent to the scar region. Recovery occurs in regions with less scar formation, the foveal region, although long term changes in foveal receptor mechanisms are apparent even after 1 year post-exposure, they do not correlate completely with recent human investigations of severe accidental exposure nor with brain enzyme analysis in our monkey model.

  1. Scattering phase function: the step-child of ocean optics

    NASA Astrophysics Data System (ADS)

    Piskozub, Jacek; Freda, Wlodzimierz

    2013-04-01

    What are inherent optical properties? The answer seems simple: absorption and scattering. Actually, this is the correct answer but only if one means by them the underlying optical processes. If the intended meaning is "absorption and scattering coefficients" the answer is wrong. Wrong because unlike absorption, scattering cannot be described by a single scalar. Scattering has angular distribution which normalized version is called the phase function. Phase functions were never ignored but for several decades they were treated as the step-child of ocean optics: an average of three single wavelenght measurements of the San Diego harbor were used in radiative transfer calculations and when more variability was needed analytical phase functions created for diffuse galactic light were utilized. Only since about 2000, real progress started. Realistic analytical phase functions were created by Haltrin as well as by Fournier and Forand. New instruments were starting to be built. Two years later Mobley and colleges proposed a parametrization of Fournier-Forand functions using backscattering coefficients. We show using Monte Carlo radiative transfer code that backscattering coefficient is not the only factor ruling the phase function shape. Reflectivity values calculated using "realistic" phase functions with identical backscattering ratios can differ by up to 10%. This is the motivation for proposing a new phase function parametrization, an improved version of one we have published in 2007. This spectral parametrization is based on Baltic phase function measurements in four wavelengths. The parameter used to choose the correct Fournier-Forand function is absorption. At this moment this is only a regional parametrization but with more data it can be improved to become a universal one. We challenge ocean optics researchers to use their measured phase function data to verify and improve our method. It is high time phase functions stopped to be treated as the step-child of

  2. Physical rehabilitation of paralysed facial muscles: functional and morphological correlates.

    PubMed

    Angelov, Doychin N

    2011-01-01

    Using a combined morphofunctional approach, we recently found that polyinnervation of the neuromuscular junction (NMJ) is the critical factor for recovery of function after transection and suture of the facial nerve. Since polyinnervation is activity-dependent and can be manipulated, we tried to design a clinically feasible therapy by electrical stimulation or by soft tissue massage. First, electrical stimulation was applied to the transected facial nerve or to paralyzed facial muscles. Both procedures did not improve vibrissal motor performance (video-based motion analysis of whisking), failed to diminish polyinnervation, and even reduced the number of innervated NMJ to one-fifth of normal values. In contrast, gentle stroking of the paralyzed vibrissal muscles by hand resulted in full recovery of whisking. Manual stimulation depended on the intact sensory supply of the denervated muscle targets and was also effective after hypoglossal-facial anastomosis, after interpositional nerve grafting, when applied to the orbicularis oculi muscle and after transection and suture of the hypoglossal nerve. From these results, we conclude that manual stimulation is a noninvasive procedure with immediate potential for clinical rehabilitation following facial nerve reconstruction.

  3. Taxonomy, morphology, masticatory function and phylogeny of heterodontosaurid dinosaurs

    PubMed Central

    Sereno, Paul C.

    2012-01-01

    Abstract Heterodontosaurids comprise an important early radiation of small-bodied herbivores that persisted for approximately 100 My from Late Triassic to Early Cretaceous time. Review of available fossils unequivocally establishes Echinodon as a very small-bodied, late-surviving northern heterodontosaurid similar to the other northern genera Fruitadens and Tianyulong. Tianyulong from northern China has unusual skeletal proportions, including a relatively large skull, short forelimb, and long manual digit II. The southern African heterodontosaurid genus Lycorhinus is established as valid, and a new taxon from the same formation is named Pegomastax africanus gen. n., sp. n. Tooth replacement and tooth-to-tooth wear is more common than previously thought among heterodontosaurids, and in Heterodontosaurus the angle of tooth-to-tooth shear is shown to increase markedly during maturation. Long-axis rotation of the lower jaw during occlusion is identified here as the most likely functional mechanism underlying marked tooth wear in mature specimens of Heterodontosaurus. Extensive tooth wear and other evidence suggests that all heterodontosaurids were predominantly or exclusively herbivores. Basal genera such as Echinodon, Fruitadens and Tianyulong with primitive, subtriangular crowns currently are known only from northern landmasses. All other genera except the enigmatic Pisanosaurus have deeper crown proportions and currently are known only from southern landmasses. PMID:23166462

  4. Hydrodynamic effects on phase separation morphologies in evaporating thin films of polymer solutions

    NASA Astrophysics Data System (ADS)

    Zoumpouli, Garyfalia A.; Yiantsios, Stergios G.

    2016-08-01

    We examine effects of hydrodynamics on phase separation morphologies developed during drying of thin films containing a volatile solvent and two dissolved polymers. Cahn-Hilliard and Flory-Huggins theories are used to describe the free energy of the phase separating systems. The thin films, considered as Newtonian fluids, flow in response to Korteweg stresses arising due to concentration non-uniformities that develop during solvent evaporation. Numerical simulations are employed to investigate the effects of a Peclet number, defined in terms of system physical properties, as well as the effects of parameters characterizing the speed of evaporation and preferential wetting of the solutes at the gas interface. For systems exhibiting preferential wetting, diffusion alone is known to favor lamellar configurations for the separated phases in the dried film. However, a mechanism of hydrodynamic instability of a short length scale is revealed, which beyond a threshold Peclet number may deform and break the lamellae. The critical Peclet number tends to decrease as the evaporation rate increases and to increase with the tendency of the polymers to selectively wet the gas interface. As the Peclet number increases, the instability moves closer to the gas interface and induces the formation of a lateral segregation template that guides the subsequent evolution of the phase separation process. On the other hand, for systems with no preferential wetting or any other property asymmetries between the two polymers, diffusion alone favors the formation of laterally separated configurations. In this case, concentration perturbation modes that lead to enhanced Korteweg stresses may be favored for sufficiently large Peclet numbers. For such modes, a second mechanism is revealed, which is similar to the solutocapillary Marangoni instability observed in evaporating solutions when interfacial tension increases with the concentration of the non-volatile component. This mechanism may lead

  5. Does morphological convergence imply functional similarity? A test using the evolution of quadrupedalism in ornithischian dinosaurs.

    PubMed

    Maidment, Susannah C R; Barrett, Paul M

    2012-09-22

    Convergent morphologies are thought to indicate functional similarity, arising because of a limited number of evolutionary or developmental pathways. Extant taxa displaying convergent morphologies are used as analogues to assess function in extinct taxa with similar characteristics. However, functional studies of extant taxa have shown that functional similarity can arise from differing morphologies, calling into question the paradigm that form and function are closely related. We test the hypothesis that convergent skeletal morphology indicates functional similarity in the fossil record using ornithischian dinosaurs. The rare transition from bipedality to quadrupedality occurred at least three times independently in this clade, resulting in a suite of convergent osteological characteristics. We use homology rather than analogy to provide an independent line of evidence about function, reconstructing soft tissues using the extant phylogenetic bracket and applying biomechanical concepts to produce qualitative assessments of muscle leverage. We also optimize character changes to investigate the sequence of character acquisition. Different lineages of quadrupedal ornithischian dinosaur stood and walked differently from each other, falsifying the hypothesis that osteological convergence indicates functional similarity. The acquisition of features correlated with quadrupedalism generally occurs in the same order in each clade, suggesting underlying developmental mechanisms that act as evolutionary constraints.

  6. Does morphological convergence imply functional similarity? A test using the evolution of quadrupedalism in ornithischian dinosaurs

    PubMed Central

    Maidment, Susannah C. R.; Barrett, Paul M.

    2012-01-01

    Convergent morphologies are thought to indicate functional similarity, arising because of a limited number of evolutionary or developmental pathways. Extant taxa displaying convergent morphologies are used as analogues to assess function in extinct taxa with similar characteristics. However, functional studies of extant taxa have shown that functional similarity can arise from differing morphologies, calling into question the paradigm that form and function are closely related. We test the hypothesis that convergent skeletal morphology indicates functional similarity in the fossil record using ornithischian dinosaurs. The rare transition from bipedality to quadrupedality occurred at least three times independently in this clade, resulting in a suite of convergent osteological characteristics. We use homology rather than analogy to provide an independent line of evidence about function, reconstructing soft tissues using the extant phylogenetic bracket and applying biomechanical concepts to produce qualitative assessments of muscle leverage. We also optimize character changes to investigate the sequence of character acquisition. Different lineages of quadrupedal ornithischian dinosaur stood and walked differently from each other, falsifying the hypothesis that osteological convergence indicates functional similarity. The acquisition of features correlated with quadrupedalism generally occurs in the same order in each clade, suggesting underlying developmental mechanisms that act as evolutionary constraints. PMID:22719033

  7. Functional morphology and patterns of blood flow in the heart of Python regius.

    PubMed

    Starck, J Matthias

    2009-06-01

    Brightness-modulated ultrasonography, continuous-wave Doppler, and pulsed-wave Doppler-echocardiography were used to analyze the functional morphology of the undisturbed heart of ball pythons. In particular, the action of the muscular ridge and the atrio-ventricular valves are key features to understand how patterns of blood flow emerge from structures directing blood into the various chambers of the heart. A step-by-step image analysis of echocardiographs shows that during ventricular diastole, the atrio-ventricular valves block the interventricular canals so that blood from the right atrium first fills the cavum venosum, and blood from the left atrium fills the cavum arteriosum. During diastole, blood from the cavum venosum crosses the muscular ridge into the cavum pulmonale. During middle to late systole the muscular ridge closes, thus prohibiting further blood flow into the cavum pulmonale. At the same time, the atrio-ventricular valves open the interventricular canal and allow blood from the cavum arteriosum to flow into the cavum venosum. In the late phase of ventricular systole, all blood from the cavum pulmonale is pressed into the pulmonary trunk; all blood from the cavum venosum is pressed into both aortas. Quantitative measures of blood flow volume showed that resting snakes bypass the pulmonary circulation and shunt about twice the blood volume into the systemic circulation as into the pulmonary circulation. When digesting, the oxygen demand of snakes increased tremendously. This is associated with shunting more blood into the pulmonary circulation. The results of this study allow the presentation of a detailed functional model of the python heart. They are also the basis for a functional hypothesis of how shunting is achieved. Further, it was shown that shunting is an active regulation process in response to changing demands of the organism (here, oxygen demand). Finally, the results of this study support earlier reports about a dual pressure

  8. Laser phase microscopy and functional imaging of living human cancer cells during the cell cycle

    NASA Astrophysics Data System (ADS)

    Perevedentseva, Elena V.; Graschew, Georgi; Balanos, Evangelos; Dressler, Cathrin; Beuthan, Juergen; Schlag, Peter M.

    2000-05-01

    The purpose of the investigation was to elaborate a new method of functional imaging of living tumor cells. Human colon carcinoma cells HCT116 were investigated with a conventional light microscope, confocal laser scanning microscope and with a laser phase microscope (LPM). The LPM is a functional imaging technique providing information about cell morphology which is imposed by the physiological inhomogeneity of the refractive index. The phase of the light wave passing through an object contains quantitative information about the object thickness, the shape, and the spatial distribution of the refractive index varying with morphology and chemical composition inhomogeneity inside the object. The new method of investigation of the cells in different stages of the cell cycle is developed. Every phase image of the investigated cells has been compared with conventional light microscopic and confocal microscopic images of the same cell. the relation between the cell state, their morphological peculiarities and the phase characteristics of the measured cell is determined. Data thus acquired, quantitatively characterizing intra- and intercellular processes during the cell cycle, and the method of measurements can be used to investigate with high optic resolution the mechanisms of different physical, chemical and biomolecular interactions with the tumor cells.

  9. Programming cancer through phase-functionalized silicon based biomaterials.

    PubMed

    Premnath, Priyatha; Venkatakrishnan, Krishnan; Tan, Bo

    2015-06-04

    Applications of biomaterials in cancer therapy has been limited to drug delivery systems and markers in radiation therapy. In this article, we introduce the concept of phase-functionalization of silicon to preferentially select cancer cell populations for survival in a catalyst and additive free approach. Silicon is phase-functionalized by the interaction of ultrafast laser pulses, resulting in the formation of rare phases of SiO2 in conjunction with differing silicon crystal lattices. The degree of phase-functionalization is programmed to dictate the degree of repulsion of cancer cells. Unstable phases of silicon oxides are synthesized during phase-functionalization and remain stable at ambient conditions. This change in phase of silicon as well as formation of oxides contributes to changes in surface chemistry as well as surface energy. These material properties elicit in precise control of migration, cytoskeleton shape, direction and population. To the best of our knowledge, phase-functionalized silicon without any changes in topology or additive layers and its applications in cancer therapy has not been reported before. This unique programmable phase-functionalized silicon has the potential to change current trends in cancer research and generate focus on biomaterials as cancer repelling or potentially cancer killing surfaces.

  10. Neuronal Oscillations with Non-sinusoidal Morphology Produce Spurious Phase-to-Amplitude Coupling and Directionality

    PubMed Central

    Lozano-Soldevilla, Diego; ter Huurne, Niels; Oostenveld, Robert

    2016-01-01

    Neuronal oscillations support cognitive processing. Modern views suggest that neuronal oscillations do not only reflect coordinated activity in spatially distributed networks, but also that there is interaction between the oscillations at different frequencies. For example, invasive recordings in animals and humans have found that the amplitude of fast oscillations (>40 Hz) occur non-uniformly within the phase of slower oscillations, forming the so-called cross-frequency coupling (CFC). However, the CFC patterns might be influenced by features in the signal that do not relate to underlying physiological interactions. For example, CFC estimates may be sensitive to spectral correlations due to non-sinusoidal properties of the alpha band wave morphology. To investigate this issue, we performed CFC analysis using experimental and synthetic data. The former consisted in a double-blind magnetoencephalography pharmacological study in which participants received either placebo, 0.5 or 1.5 mg of lorazepam (LZP; GABAergic enhancer) in different experimental sessions. By recording oscillatory brain activity with during rest and working memory (WM), we were able to demonstrate that posterior alpha (8–12 Hz) phase was coupled to beta-low gamma band (20–45 Hz) amplitude envelope during all sessions. Importantly, bicoherence values around the harmonics of the alpha frequency were similar both in magnitude and topographic distribution to the cross-frequency coherence (CFCoh) values observed in the alpha-phase to beta-low gamma coupling. In addition, despite the large CFCoh we found no significant cross-frequency directionality (CFD). Critically, simulations demonstrated that a sizable part of our empirical CFCoh between alpha and beta-low gamma coupling and the lack of CFD could be explained by two-three harmonics aligned in zero phase-lag produced by the physiologically characteristic alpha asymmetry in the amplitude of the peaks relative to the troughs. Furthermore, we

  11. Frequency-phase analysis of resting-state functional MRI

    PubMed Central

    Goelman, Gadi; Dan, Rotem; Růžička, Filip; Bezdicek, Ondrej; Růžička, Evžen; Roth, Jan; Vymazal, Josef; Jech, Robert

    2017-01-01

    We describe an analysis method that characterizes the correlation between coupled time-series functions by their frequencies and phases. It provides a unified framework for simultaneous assessment of frequency and latency of a coupled time-series. The analysis is demonstrated on resting-state functional MRI data of 34 healthy subjects. Interactions between fMRI time-series are represented by cross-correlation (with time-lag) functions. A general linear model is used on the cross-correlation functions to obtain the frequencies and phase-differences of the original time-series. We define symmetric, antisymmetric and asymmetric cross-correlation functions that correspond respectively to in-phase, 90° out-of-phase and any phase difference between a pair of time-series, where the last two were never introduced before. Seed maps of the motor system were calculated to demonstrate the strength and capabilities of the analysis. Unique types of functional connections, their dominant frequencies and phase-differences have been identified. The relation between phase-differences and time-delays is shown. The phase-differences are speculated to inform transfer-time and/or to reflect a difference in the hemodynamic response between regions that are modulated by neurotransmitters concentration. The analysis can be used with any coupled functions in many disciplines including electrophysiology, EEG or MEG in neuroscience. PMID:28272522

  12. Frequency-phase analysis of resting-state functional MRI.

    PubMed

    Goelman, Gadi; Dan, Rotem; Růžička, Filip; Bezdicek, Ondrej; Růžička, Evžen; Roth, Jan; Vymazal, Josef; Jech, Robert

    2017-03-08

    We describe an analysis method that characterizes the correlation between coupled time-series functions by their frequencies and phases. It provides a unified framework for simultaneous assessment of frequency and latency of a coupled time-series. The analysis is demonstrated on resting-state functional MRI data of 34 healthy subjects. Interactions between fMRI time-series are represented by cross-correlation (with time-lag) functions. A general linear model is used on the cross-correlation functions to obtain the frequencies and phase-differences of the original time-series. We define symmetric, antisymmetric and asymmetric cross-correlation functions that correspond respectively to in-phase, 90° out-of-phase and any phase difference between a pair of time-series, where the last two were never introduced before. Seed maps of the motor system were calculated to demonstrate the strength and capabilities of the analysis. Unique types of functional connections, their dominant frequencies and phase-differences have been identified. The relation between phase-differences and time-delays is shown. The phase-differences are speculated to inform transfer-time and/or to reflect a difference in the hemodynamic response between regions that are modulated by neurotransmitters concentration. The analysis can be used with any coupled functions in many disciplines including electrophysiology, EEG or MEG in neuroscience.

  13. Systematic morphological profiling of human gene and allele function via Cell Painting

    PubMed Central

    Rohban, Mohammad Hossein; Singh, Shantanu; Wu, Xiaoyun; Berthet, Julia B; Bray, Mark-Anthony; Shrestha, Yashaswi; Varelas, Xaralabos; Boehm, Jesse S; Carpenter, Anne E

    2017-01-01

    We hypothesized that human genes and disease-associated alleles might be systematically functionally annotated using morphological profiling of cDNA constructs, via a microscopy-based Cell Painting assay. Indeed, 50% of the 220 tested genes yielded detectable morphological profiles, which grouped into biologically meaningful gene clusters consistent with known functional annotation (e.g., the RAS-RAF-MEK-ERK cascade). We used novel subpopulation-based visualization methods to interpret the morphological changes for specific clusters. This unbiased morphologic map of gene function revealed TRAF2/c-REL negative regulation of YAP1/WWTR1-responsive pathways. We confirmed this discovery of functional connectivity between the NF-κB pathway and Hippo pathway effectors at the transcriptional level, thereby expanding knowledge of these two signaling pathways that critically regulate tumor initiation and progression. We make the images and raw data publicly available, providing an initial morphological map of major biological pathways for future study. DOI: http://dx.doi.org/10.7554/eLife.24060.001 PMID:28315521

  14. Phase function effects for ocean color retrieval algorithm

    NASA Astrophysics Data System (ADS)

    Du, KePing; Lee, Zhongping

    2010-10-01

    Inherent optical properties (IOPs), e.g., absorption, back scattering coefficients, and volume scattering function, are important parameters for radiance transfer simulation. Commercially available instruments (e.g., Wetlabs ACS, BB9, etc, and HOBILabs a-sphere, HS6, etc) basically only measure absorption and back scattering coefficients. In this paper, we used the same IOPs of International Ocean-Colour Coordinating Group (IOCCG) report 5 and Hydrolight to simulate the radiance distribution, however, different phase functions, say, a new phase function derived from the measured data by multispectral volume scattering meter (MVSM) in coastal waters, the widely used Petzold average phase function, and the Fournier-Forand (FF) phase function, were employed in the simulations. The simulation results were used to develop the retrieval algorithm with angular effects correction based on the quasi-analytical algorithm(QAA) developed by Lee et al.. Results showed that not only the back scattering probability, but also the angular shape of phase function are important for ocean color retrieval algorithm. Considering the importance of phase function in ocean color remote sensing, methods to validate the phase function data should be developed.

  15. Transcriptional and morphological changes in the transition from mycetophagous to phytophagous phase in the plant-parasitic nematode Bursaphelenchus xylophilus.

    PubMed

    Tsai, Isheng J; Tanaka, Ryusei; Kanzaki, Natsumi; Akiba, Mitsuteru; Yokoi, Toshiro; Espada, Margarida; Jones, John T; Kikuchi, Taisei

    2016-01-01

    Drastic physiological and morphological changes in parasites are crucial for the establishment of a successful infection. The nematode Bursaphelenchus xylophilus is the pathogenic agent of pine wilt disease, and little is known about the physiology and morphology in this nematode at the initial stage of infection. In this study, we devised an infection system using pine stem cuttings that allowed us to observe transcriptional and morphological changes in the host-infecting phytophagous phase. We found that 60 genes enriched in xenobiotic detoxification were up-regulated in two independent post-inoculation events, whereas down-regulation was observed in multiple members of collagen gene families. After 48 h of inoculation, the tails in some of the adult females exposed to the host changed in morphology. These results suggest that B. xylophilus may change its physiology and morphology to protect itself and to adapt to the host pine wood environment.

  16. Morphological Phase Behavior of Poly(RTIL)-Containing Diblock Copolymer Melts

    SciTech Connect

    Scalfani, VF; Wiesenauer, EF; Ekblad, JR; Edwards, JP; Gin, DL; Bailey, TS

    2012-05-22

    The development of nanostructured polymeric systems containing directionally continuous poly(ionic liquid) (poly(IL)) domains has considerable implications toward a range of transport-dependent, energy-based technology applications. The controlled, synthetic integration of poly(IL)s into block copolymer (BCP) architectures provides a promising means to this end, based on their inherent ability to self-assemble into a range of defined, periodic morphologies. In this work, we report the melt-state phase behavior of an imidazolium-containing alkyl ionic BCP system, derived from the sequential ring-opening metathesis polymerization (ROMP) of imidazolium- and alkyl-substituted norbornene monomer derivatives. A series of 16 BCP samples were synthesized, varying both the relative volume fraction of the poly(norbornene dodecyl ester) block (f(DOD) = 0.42-0.96) and the overall molecular weights of the block copolymers (M-n values from 5000-20 100 g mol(-1)). Through a combination of small-angle X-ray scattering (SAXS) and dynamic rheology, we were able to delineate clear compositional phase boundaries for each of the classic BCP phases, including lamellae (Lam), hexagonally packed cylinders (Hex), and spheres on a body-centered-cubic lattice (S-BCC). Additionally, a liquid-like packing (LLP) of spheres was found for samples located in the extreme asymmetric region of the phase diagram, and a persistent coexistence of Lam and Hex domains was found in lieu of the bicontinuous cubic gyroid phase for samples located at the intersection of Hex and Lam regions. Thermal disordering was opposed even in very low molecular weight samples, detected only when the composition was highly asymmetric (f(DOD) = 0.96). Annealing experiments on samples exhibiting Lam and Hex coexistence revealed the presence of extremely slow transition kinetics, ultimately selective for one or the other but not the more complex gyroid phase. In fact, no evidence of the bicontinuous network was detected over

  17. Morphological Phase Behavior of Poly(RTIL)-Containing Diblock Copolymer Melts

    SciTech Connect

    Scalfani, Vincent F.; Wiesenauer, Erin F.; Ekblad, John R.; Edwards, Julian P.; Gin, Douglas L.; Bailey, Travis S.

    2012-10-23

    The development of nanostructured polymeric systems containing directionally continuous poly(ionic liquid) (poly(IL)) domains has considerable implications toward a range of transport-dependent, energy-based technology applications. The controlled, synthetic integration of poly(IL)s into block copolymer (BCP) architectures provides a promising means to this end, based on their inherent ability to self-assemble into a range of defined, periodic morphologies. In this work, we report the melt-state phase behavior of an imidazolium-containing alkyl-ionic BCP system, derived from the sequential ring-opening metathesis polymerization (ROMP) of imidazolium- and alkyl-substituted norbornene monomer derivatives. A series of 16 BCP samples were synthesized, varying both the relative volume fraction of the poly(norbornene dodecyl ester) block (f{sub DOD} = 0.42-0.96) and the overall molecular weights of the block copolymers (M{sub n} values from 5000-20,100 g mol{sup -1}). Through a combination of small-angle X-ray scattering (SAXS) and dynamic rheology, we were able to delineate clear compositional phase boundaries for each of the classic BCP phases, including lamellae (Lam), hexagonally packed cylinders (Hex), and spheres on a body-centered-cubic lattice (S{sub BCC}). Additionally, a liquid-like packing (LLP) of spheres was found for samples located in the extreme asymmetric region of the phase diagram, and a persistent coexistence of Lam and Hex domains was found in lieu of the bicontinuous cubic gyroid phase for samples located at the intersection of Hex and Lam regions. Thermal disordering was opposed even in very low molecular weight samples, detected only when the composition was highly asymmetric (f{sub DOD} = 0.96). Annealing experiments on samples exhibiting Lam and Hex coexistence revealed the presence of extremely slow transition kinetics, ultimately selective for one or the other but not the more complex gyroid phase. In fact, no evidence of the bicontinuous

  18. Interpolating function of the strain relief of epitaxial quantum dots via an alternative morphological descriptor

    NASA Astrophysics Data System (ADS)

    Scopece, Daniele

    2015-05-01

    Assessing the equilibrium morphologies of self-assembled heteroepitaxial quantum dots requires the estimation of their elastic (volumetric), surface, and edge energy contribution, all of them being shape dependent. Due to the size and multifaceted morphology of these islands, the estimation of the first term is typically a time-consuming or complicated task. A general rule to predict it from the sole morphologies would guarantee a precious advantage in this field. Here we present an interpolating function to fulfill this purpose for the prototypical systems of Ge/Si and InAs/GaAs. The trend is first extracted from a systematic analysis of realistic shapes observed on (001) substrates. It is then tested and corroborated for selected vicinal (tilted) substrates. Finally, the deviations due to intermixing and the underlying wetting layer are quantified. Of fundamental importance in this process is the identification of a morphological descriptor more accurate than the widely adopted aspect ratio, the limitations of which are discussed.

  19. Origin of phase shift in atomic force microscopic investigation of the surface morphology of NR/NBR blend film.

    PubMed

    Thanawan, S; Radabutra, S; Thamasirianunt, P; Amornsakchai, T; Suchiva, K

    2009-01-01

    Atomic force microscopy (AFM) was used to study the morphology and surface properties of NR/NBR blend. Blends at 1/3, 1/1 and 3/1 weight ratios were prepared in benzene and formed film by casting. AFM phase images of these blends in tapping mode displayed islands in the sea morphology or matrix-dispersed structures. For blend 1/3, NR formed dispersed phase while in blends 1/1 and 3/1 phase inversion was observed. NR showed higher phase shift angle in AFM phase imaging for all blends. This circumstance was governed by adhesion energy hysteresis between the device tip and the rubber surface rather than surface stiffness of the materials, as proved by force distance measurements in the AFM contact mode.

  20. Morphological analysis and muscle-associated gene expression during different muscle growth phases of Megalobrama amblycephala.

    PubMed

    Zhu, K C; Yu, D H; Zhao, J K; Wang, W M; Wang, H L

    2015-09-28

    Skeletal muscle growth is regulated by both positive and negative factors, such as myogenic regulatory factors (MRFs) and myostatin (MSTN), and involves both hyperplasia and hypertrophy. In the present study, morphological changes during muscle development in Megalobrama amblycephala were characterized and gene expression levels were measured by quantitative real-time polymerase chain reaction (qRT-PCR) analysis in juvenile [60, 90, 120, and 180 days post-hatching (dph)] and adult fish. Our results show that during muscle development, the frequency of muscle fibers with a diameter <20 μm dramatically decreased in both red and white muscles, with a concomitant increase in the frequency of >30 μm fibers in red muscle and >50 μm fibers in white muscle. At 90-120 dph, the ratio of hyperplastic to hypertrophic areas in red and white muscles increased, but later decreased at 120-180 dph. The effect of hypertrophy was significantly larger than hyperplasia during these phases. qRT-PCR indicated MRF and MSTN (MSTNa and MSTNb) genes had similar expression patterns that peaked at 120 dph, with the exception of MSTNa. This new information on the molecular regulation of muscle growth and rapid growth phases will be of value to the cultivation of M. amblycephala.

  1. Evolution of phase and morphology of titanium dioxide induced from peroxo titanate complex aqueous solution.

    PubMed

    Chang, Jeong Ah; Vithal, Muga; Baek, In Chan; Seok, Sang Il

    2010-01-01

    We demonstrate the growth of anatase TiO2 in nanospheres and rutile TiO2 in nanorods, by the hydrolysis of titanium tetraisopropoxide (TTIP) in the presence of hydrogen peroxide at 100 degrees C using sol-gel method. X-ray diffraction (XRD), Raman spectroscopy, transmission electron microscopy (TEM), high resolution transmission electron microscopy (HRTEM), selected area electron diffraction (SAED), scanning electron microscopy (SEM), and surface area measurement techniques are used to characterize the phase and shape developments of TiO2 obtained from peroxo titanate complex in an aqueous solution at 100 degrees C. Peroxo titanate complexes were prepared by a reaction of titanium hydroxide, formed by hydrolysis of titanium tetraisopropoxide (TTIP), and different amounts of hydrogen peroxide (H2O2). TEM and XRD investigations reveal that the size of spheres (anatase) and rods (rutile) are about 8 nm (diameter) and about 13 x 29 nm approximately 20 x 75 nm (width x length) respectively. The influence of molar ratio of H2O2/TTIP on the phase and morphology of TiO2 is presented. A mixture of anatase spheres and short rutile rods are formed at low H2O2/TTIP ratio while predominantly rutile a quit long rods are formed at higher H2O2/TTIP ratio.

  2. The mechanisms of morphological-motor functioning in elementary school female first- to fourth-graders.

    PubMed

    Katić, Ratko; Pejcić, Aleksandra; Viskić-Stalec, Natasa

    2004-06-01

    Four morphological and 7 motor variables were assessed in a sample of 2,235 female children (subdivided into 4 groups) aged 7-11 years, elementary school first- to fourth-graders from the Primorje-Gorski Kotar County, Republic of Croatia. The study objective was to analyze the morphological-motor structures according to age. Factor analysis was done for each of the four subject groups. Results clearly showed the morphological-motor functioning of the girls to change with age. Developmental processes lead to the formation of a general morphological factor defined as ectomesomorph and two general mechanisms responsible for motor efficiency in the form of strength regulation and speed regulation. The results obtained were found to be consistent with the existing relevant models related to the morphological, motor, functional and cognitive systems. The more so, these results allow for a supramodel to design, which will integrate relevant elements of all these models to define the function of the body as a whole.

  3. Linking morphological and functional variability in hand movement and silent reading.

    PubMed

    Sun, Z Y; Pinel, P; Rivière, D; Moreno, A; Dehaene, S; Mangin, J-F

    2016-09-01

    It is generally accepted in neuroscience that anatomy and function go hand in hand. Accordingly, a local morphological variability could lead to a corresponding functional variability. In this study, we tested this hypothesis by linking the variability of the cortical folding pattern of 252 right-handed subjects to the localization or the pattern of functional activations induced by hand motion or silent reading. Three regions are selected: the central sulcus, the precentral sulcus and the superior temporal sulcus (STS). "Essential morphological variability traits" are identified using a method building upon multidimensional scaling. The link between variability in anatomy and function is confirmed by the perfect match between the central sulcus morphological "hand knob" and the corresponding motor activation: as the location of the hand knob moves more or less dorsally along the central sulcus, the motor hand activation moves accordingly. Furthermore, the size of the left hand activation in the right hemisphere is correlated with the knob location in the central sulcus. A new link between functional and morphological variability is discovered relative to the location of a premotor activation induced by silent reading. While this reading activation is located next to the wall of the central sulcus when the hand knob has a ventral positioning, it is pushed into a deep gyrus interrupting the precentral sulcus when the knob is more dorsal. Finally, it is shown that the size of the reading activation along the STS is larger when the posterior branches are less developed.

  4. Morphological and functional abnormalities of salience network in the early-stage of paranoid schizophrenia.

    PubMed

    Pu, Weidan; Li, Li; Zhang, Huiran; Ouyang, Xuan; Liu, Haihong; Zhao, Jingping; Li, Lingjiang; Xue, Zhimin; Xu, Ke; Tang, Haibo; Shan, Baoci; Liu, Zhening; Wang, Fei

    2012-10-01

    A salience network (SN), mainly composed of the anterior insula (AI) and anterior cingulate cortex (ACC), has been suggested to play an important role in salience attribution which has been proposed as central to the pathology of paranoid schizophrenia. The role of this SN in the pathophysiology of paranoid schizophrenia, however, still remains unclear. In the present study, voxel-based morphometry and resting-state functional connectivity analyses were combined to identify morphological and functional abnormalities in the proposed SN in the early-stage of paranoid schizophrenia (ESPS). Voxel-based morphometry and resting-state functional connectivity analyses were applied to 90 ESPS patients and 90 age- and sex-matched healthy controls (HC). Correlation analyses were performed to examine the relationships between various clinical variables and both gray matter morphology and functional connectivity within the SN in ESPS. Compared to the HC group, the ESPS group showed significantly reduced gray matter volume (GMV) in both bilateral AI and ACC. Moreover, significantly reduced functional connectivity within the SN sub-networks was identified in the ESPS group. These convergent morphological and functional deficits in SN were significantly associated with hallucinations. Additionally, illness duration correlated with reduced GMV in the left AI in ESPS. In conclusion, these findings provide convergent evidence for the morphological and functional abnormalities of the SN in ESPS. Moreover, the association of illness duration with the reduced GMV in the left AI suggests that the SN and the AI, in particular, may manifest progressive morphological changes that are especially important in the emergence of ESPS.

  5. Spectrally Shaped Random-Phase Spreading Functions

    DTIC Science & Technology

    2003-10-24

    gain reduction due to reference function windowing. 18 3.3 Excision of narrow band interference. 19 4 4.1 Hardware based adaptive system with...frequency-spread CW interference falling within the data-rate bandwidth. Assuming that fref(t) is at base band, i.e. having a spectrum extending from zero...report describes the baseband hardware demonstrator based upon AT&T DSP32C digital signal processing cards in an IBM personal computer host platform, and

  6. Morphological evolution of X-ray flare structures from the rise through the decay phase. [Skylab study of solar flares

    NASA Technical Reports Server (NTRS)

    Kahler, S. W.; Krieger, A. S.; Vaiana, G. S.

    1975-01-01

    The morphological evolution of 12 solar X-ray subflares from onset through the decay phase has been studied using photographic X-ray images obtained from Skylab. The spatial configurations are found to vary widely from flare to flare, but they appear to be composed of two basic kinds of structures. The first, termed 'X-ray kernels', are brightest during the rise phase; the second, looplike structures, appear during the maximum and decay phases of the event. The X-ray kernels are small pointlike structures which may be related to the nonthermal phases of flares.

  7. Phase, morphology, and hygroscopicity of mixed oleic acid/sodium chloride/water aerosol particles before and after ozonolysis.

    PubMed

    Dennis-Smither, Benjamin J; Hanford, Kate L; Kwamena, Nana-Owusua A; Miles, Rachael E H; Reid, Jonathan P

    2012-06-21

    Aerosol optical tweezers are used to probe the phase, morphology, and hygroscopicity of single aerosol particles consisting of an inorganic component, sodium chloride, and a water insoluble organic component, oleic acid. Coagulation of oleic acid aerosol with an optically trapped aqueous sodium chloride droplet leads to formation of a phase-separated particle with two partially engulfed liquid phases. The dependence of the phase and morphology of the trapped particle with variation in relative humidity (RH) is investigated by cavity enhanced Raman spectroscopy over the RH range <5% to >95%. The efflorescence and deliquescence behavior of the inorganic component is shown to be unaffected by the presence of the organic phase. Whereas efflorescence occurs promptly (<1 s), the deliquescence process requires both dissolution of the inorganic component and the adoption of an equilibrium morphology for the resulting two phase particle, occurring on a time-scale of <20 s. Comparative measurements of the hygroscopicity of mixed aqueous sodium chloride/oleic acid droplets with undoped aqueous sodium chloride droplets show that the oleic acid does not impact on the equilibration partitioning of water between the inorganic component and the gas phase or the time response of evaporation/condensation. The oxidative aging of the particles through reaction with ozone is shown to increase the hygroscopicity of the organic component.

  8. Gas-phase azide functionalization of carbon.

    PubMed

    Stenehjem, Eric D; Ziatdinov, Vadim R; Stack, T Daniel P; Chidsey, Christopher E D

    2013-01-23

    Tailoring the surface and interfacial properties of inexpensive and abundant carbon materials plays an increasingly important role for innovative applications including those in electrocatalysis, energy storage, gas separations, and composite materials. Described here is the novel preparation and subsequent use of gaseous iodine azide for the azide modification of carbon surfaces. In-line generation of gaseous iodine azide from iodine monochloride vapor and solid sodium azide is safe and convenient. Immediate treatment of carbon surfaces with this gaseous stream of iodine azide provides a highly reproducible, selective, and scalable azide functionalization that minimizes waste and reduces deleterious side reactions. Among the possible uses of azide-modified surfaces, they serve as versatile substrates for the attachment of additional functionality by coupling with terminal alkynes under the mild copper-catalyzed azide-alkyne cycloaddition (CuAAC) "click" reaction. For instance, coupling ethynylferrocene to azide-modified glassy carbon surfaces achieves ferrocene coverage up to 8 × 10(13) molecules/cm(2) by voltammetric and XPS analyses. The 1,2,3-triazole linker formed during the CuAAC reaction is robust and hydrolytically stable in both aqueous 1 M HClO(4) and 1 M NaOH for at least 12 h at 100 °C.

  9. Nanofiber Composite Membranes for Alkaline Fuel Cells: Generation of Compositional, Morphological, and Functional Property Relationships

    DTIC Science & Technology

    2015-12-01

    properties of nanofiber composite anion-exchange membranes for alkaline fuel cells. A new membrane fabrication strategy, utilizing polymer fiber...electrospinning, will be employed to make hydroxide-conducting membranes with an entirely new morphology, where one electrospun polymer provides pathways...for ion conductivity and the second electrospun polymer restricts ionomer swelling and imparts mechanical strength to the membrane. The functional

  10. Functional morphology of the hallucal metatarsal with implications for inferring grasping ability in extinct primates.

    PubMed

    Goodenberger, Katherine E; Boyer, Doug M; Orr, Caley M; Jacobs, Rachel L; Femiani, John C; Patel, Biren A

    2015-03-01

    Primate evolutionary morphologists have argued that selection for life in a fine branch niche resulted in grasping specializations that are reflected in the hallucal metatarsal (Mt1) morphology of extant "prosimians", while a transition to use of relatively larger, horizontal substrates explains the apparent loss of such characters in anthropoids. Accordingly, these morphological characters-Mt1 torsion, peroneal process length and thickness, and physiological abduction angle-have been used to reconstruct grasping ability and locomotor mode in the earliest fossil primates. Although these characters are prominently featured in debates on the origin and subsequent radiation of Primates, questions remain about their functional significance. This study examines the relationship between these morphological characters of the Mt1 and a novel metric of pedal grasping ability for a large number of extant taxa in a phylogenetic framework. Results indicate greater Mt1 torsion in taxa that engage in hallucal grasping and in those that utilize relatively small substrates more frequently. This study provides evidence that Carpolestes simpsoni has a torsion value more similar to grasping primates than to any scandentian. The results also show that taxa that habitually grasp vertical substrates are distinguished from other taxa in having relatively longer peroneal processes. Furthermore, a longer peroneal process is also correlated with calcaneal elongation, a metric previously found to reflect leaping proclivity. A more refined understanding of the functional associations between Mt1 morphology and behavior in extant primates enhances the potential for using these morphological characters to comprehend primate (locomotor) evolution.

  11. Double-bromo and extraterminal (BET) domain proteins regulate dendrite morphology and mechanosensory function

    PubMed Central

    Bagley, Joshua A.; Yan, Zhiqiang; Zhang, Wei; Wildonger, Jill

    2014-01-01

    A complex array of genetic factors regulates neuronal dendrite morphology. Epigenetic regulation of gene expression represents a plausible mechanism to control pathways responsible for specific dendritic arbor shapes. By studying the Drosophila dendritic arborization (da) neurons, we discovered a role of the double-bromodomain and extraterminal (BET) family proteins in regulating dendrite arbor complexity. A loss-of-function mutation in the single Drosophila BET protein encoded by female sterile 1 homeotic [fs(1)h] causes loss of fine, terminal dendritic branches. Moreover, fs(1)h is necessary for the induction of branching caused by a previously identified transcription factor, Cut (Ct), which regulates subtype-specific dendrite morphology. Finally, disrupting fs(1)h function impairs the mechanosensory response of class III da sensory neurons without compromising the expression of the ion channel NompC, which mediates the mechanosensitive response. Thus, our results identify a novel role for BET family proteins in regulating dendrite morphology and a possible separation of developmental pathways specifying neural cell morphology and ion channel expression. Since the BET proteins are known to bind acetylated histone tails, these results also suggest a role of epigenetic histone modifications and the “histone code,” in regulating dendrite morphology. PMID:25184680

  12. Wigner function and Schroedinger equation in phase-space representation

    SciTech Connect

    Chruscinski, Dariusz; Mlodawski, Krzysztof

    2005-05-15

    We discuss a family of quasidistributions (s-ordered Wigner functions of Agarwal and Wolf [Phys. Rev. D 2, 2161 (1970); Phys. Rev. D 2, 2187 (1970); Phys. Rev. D 2, 2206 (1970)]) and its connection to the so-called phase space representation of the Schroedinger equation. It turns out that although Wigner functions satisfy the Schroedinger equation in phase space, they have a completely different interpretation.

  13. Phase transition and surface morphology of MnAs/GaAs(001) studied with in situ variable-temperature scanning tunneling microscopy

    NASA Astrophysics Data System (ADS)

    Breitwieser, R.; Vidal, F.; Graff, I. L.; Marangolo, M.; Eddrief, M.; Boulliard, J.-C.; Etgens, V. H.

    2009-07-01

    The MnAs phase transition from the hexagonal ferromagnetic α to the orthorhombic paramagnetic β phase has been investigated in situ by variable-temperature scanning tunneling microscopy (STM) as a function of epilayer thickness. The α-β phase coexistence leads to the formation of a self-organized stripes pattern of alternating α and β regions. The morphology evolution of the α-β periodic array of domains has been imaged in detail. The period and corrugation of this pattern are linear functions of the epilayer thickness with a domain periodicity nearly five times larger than film thickness. Also, STM local imaging through the phase-coexistence region (10-45°C) shows unambiguously the absence of mass transport during the transition. The self-organization of α-β stripes is consistent with an elastic-energy equilibrium state of the heteroepitaxial system at each temperature, as previously proposed for the origin of the modulated structure [V. M. Kaganer , Phys. Rev. B 66, 045305 (2002)]. Independently of self-organized α-β regions, the surface displays anisotropic mounds that are elongated along MnAs a axis. This facetting process leads to a peculiar, highly anisotropic surface with oriented facets and submicron periodic modulation along the hexagonal c axis. Smoother surfaces with larger terraces are obtained following postgrowth annealing. These results suggest that a careful control of the growth temperature and annealing procedure can be used to tailor the surface morphology for specific applications requiring anisotropic templates.

  14. Phase-Amplitude Response Functions for Transient-State Stimuli

    PubMed Central

    2013-01-01

    Abstract The phase response curve (PRC) is a powerful tool to study the effect of a perturbation on the phase of an oscillator, assuming that all the dynamics can be explained by the phase variable. However, factors like the rate of convergence to the oscillator, strong forcing or high stimulation frequency may invalidate the above assumption and raise the question of how is the phase variation away from an attractor. The concept of isochrons turns out to be crucial to answer this question; from it, we have built up Phase Response Functions (PRF) and, in the present paper, we complete the extension of advancement functions to the transient states by defining the Amplitude Response Function (ARF) to control changes in the transversal variables. Based on the knowledge of both the PRF and the ARF, we study the case of a pulse-train stimulus, and compare the predictions given by the PRC-approach (a 1D map) to those given by the PRF-ARF-approach (a 2D map); we observe differences up to two orders of magnitude in favor of the 2D predictions, especially when the stimulation frequency is high or the strength of the stimulus is large. We also explore the role of hyperbolicity of the limit cycle as well as geometric aspects of the isochrons. Summing up, we aim at enlightening the contribution of transient effects in predicting the phase response and showing the limits of the phase reduction approach to prevent from falling into wrong predictions in synchronization problems. List of Abbreviations PRC phase response curve, phase resetting curve. PRF phase response function. ARF amplitude response function. PMID:23945295

  15. Investigation of middle ear anatomy and function with combined video otoscopy-phase sensitive OCT

    PubMed Central

    Park, Jesung; Cheng, Jeffrey T.; Ferguson, Daniel; Maguluri, Gopi; Chang, Ernest W.; Clancy, Caitlin; Lee, Daniel J.; Iftimia, Nicusor

    2016-01-01

    We report the development of a novel otoscopy probe for assessing middle ear anatomy and function. Video imaging and phase-sensitive optical coherence tomography are combined within the same optical path. A sound stimuli channel is incorporated as well to study middle ear function. Thus, besides visualizing the morphology of the middle ear, the vibration amplitude and frequency of the eardrum and ossicles are retrieved as well. Preliminary testing on cadaveric human temporal bone models has demonstrated the capability of this instrument for retrieving middle ear anatomy with micron scale resolution, as well as the vibration of the tympanic membrane and ossicles with sub-nm resolution. PMID:26977336

  16. Do Swiftlets have an ear for echolocation? The functional morphology of Swiftlets' middle ears.

    PubMed

    Thomassen, Henri A; Gea, Stefan; Maas, Steve; Bout, Ron G; Dirckx, Joris J J; Decraemer, Willem F; Povel, G David E

    2007-03-01

    The Oilbird and many Swiftlet species are unique among birds for their ability to echolocate. Echolocaters may benefit from improved hearing sensitivity. Therefore, morphological adaptations to echolocation might be present in echolocating birds' middle ears. We studied the functional morphology of the tympano-ossicular chain of seven specimens of four echolocating Swiftlet species and one specimen each of five non-echolocating species. Three dimensional (3D) reconstructions were made from micro-Computer-Tomographic (muCT) scans. The reconstructions were used in functional morphological analyses and model calculations. A two dimensional (2D) rigid rod model with fixed rotational axes was developed to study footplate output-amplitudes and to describe how changes in the arrangement of the tympano-ossicular chain affect its function. A 3D finite element model was used to predict ossicular-chain movement and to investigate the justification of the 2D approach. No morphological adaptations towards echolocation were found in the middle-ear lever system or in the mass impedance of the middle ear. A wide range of middle-ear configurations result in maximum output-amplitudes and all investigated species are congruent with these predicted best configurations. Echolocation is unlikely to depend on adaptations in the middle ear tympano-ossicular chain.

  17. In-situ Neutron Scattering Determination of 3D Phase-Morphology Correlations in Fullerene Block Copolymer Systems

    SciTech Connect

    Karim, Alamgir; Bucknall, David; Raghavan, Dharmaraj

    2015-02-23

    a fundamental study that does not set out to evaluate new materials or produce devices, but rather we wish to understand from first principles how the molecular structure of polymer-fullerene mixtures determined using neutron scattering (small angle neutron scattering and neutron reflection) affects device characteristics and consequently performance. While this seems a very obvious question to ask, this critical understanding is far from being realized despite the wealth of studies into OPV’s and is severely limiting organic PV devices from achieving their theoretical potential. Despite the fundamental nature of proposed work, it is essential to remain technologically relevant and therefore to ensure we address these issues we have developed relationships on the fundamental nature of structure-processing-property paradigm as applied to future need for large area, flexible OPV devices. Nanoscale heterojunction systems consisting of fullerenes dispersed in conjugated polymers are promising materials candidates for achieving high performance organic photovoltaic (OPV) devices. In order to understand the phase behavior in these devices, neutron reflection is used to determine the behavior of model conjugated polymer-fullerene mixtures. Neutron reflection is particularly useful for these types of thin film studies since the fullerene generally have a high scattering contrast with respect to most polymers. We are studying model bulk heterojunction (BHJ) films based on mixtures of poly(3-hexyl thiophene)s (P3HT), a widely used photoconductive polymer, and different fullerenes (C60, PCBM and bis-PCBM). The characterization technique of neutron reflectivity measurements have been used to determine film morphology in a direction normal to the film surfaces. The novelty of the approach over previous studies is that the BHJ layer is sandwiched between a PEDOT/PSS and Al layers in real device configuration. Using this model system, the effect of typical thermal annealing

  18. Relating the ontogeny of functional morphology and prey selection with larval mortality in Amphiprion frenatus.

    PubMed

    Anto, Justin; Turingan, Ralph G

    2010-06-01

    Survival during the pelagic larval phase of marine fish is highly variable and is subject to numerous factors. A sharp decline in the number of surviving larvae usually occurs during the transition from endogenous to exogenous feeding known as the first feeding stage in fish larvae. The present study was designed to evaluate the link between functional morphology and prey selection in an attempt to understand how the relationship influences mortality of a marine fish larva, Amphiprion frenatus, through ontogeny. Larvae were reared from hatch to 14 days post hatch (DPH) with one of four diets [rotifers and newly hatched Artemia sp. nauplii (RA); rotifers and wild plankton (RP); rotifers, wild plankton, and newly hatched Artemia nauplii (RPA); wild plankton and newly hatched Artemia nauplii (PA)]. Survival did not differ among diets. Larvae from all diets experienced mass mortality from 1 to 5 DPH followed by decreased mortality from 6 to 14 DPH; individuals fed RA were the exception, exhibiting continuous mortality from 6 to 14 DPH. Larvae consumed progressively larger prey with growth and age, likely due to age related increase in gape. During the mass mortality event, larvae selected small prey items and exhibited few ossified elements. Cessation of mass mortality coincided with consumption of large prey and ossification of key elements of the feeding apparatus. Mass mortality did not appear to be solely influenced by inability to establish first feeding. We hypothesize the interaction of reduced feeding capacities (i.e., complexity of the feeding apparatus) and larval physiology such as digestion or absorption efficiency contributed to the mortality event during the first feeding period.

  19. Phase- and morphology-controlled synthesis of cobalt sulfide nanocrystals and comparison of their catalytic activities for hydrogen evolution

    NASA Astrophysics Data System (ADS)

    Pan, Yuan; Liu, Yunqi; Liu, Chenguang

    2015-12-01

    Colalt sulfide nanocrystals (NCs), including dandelion-like Co9S8 and sphere-like Co3S4, have been synthesized via a thermal decomposition approach using cobalt acetylacetonate as the cobalt source, 1-dodecanethiol as the sulfur source and oleic acid or oleylamine as the high boiling organic solvent. It is found that the molar ratio of the Co:S precursor and the species of solvent play an important role in the control of phase and morphology of cobalt sulfide nanostructures. The phase structure and morphology of the as-synthesized nickel sulfide NCs are characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscope (SEM), energy dispersive spectrum (EDS) mapping, X-ray photoelectron spectroscopy (XPS) and N2 adsorption-desorption. Then we further compare the electrocatalytic activity and stability of as-synthesized cobalt sulfide NCs for hydrogen evolution reaction (HER). The results show that sphere-like Co3S4 exhibits better electrocatalytic activity than the dandelion-like Co9S8 NCs for HER, which can be attributed to the difference of phase structure and morphology. The sphere-like Co3S4 NCs have large surface area and high electrical conductivity, both are beneficial to enhance the catalytic activity. This study indicates that the crystalline phase structure and morphology of cobalt sulfide NCs are important for designing HER electrocatalysts with high efficiency and good stability.

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

    PubMed Central

    Yang, Yu; Yao, Hongwei

    2015-01-01

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

  1. Low-temperature Phase and Morphology Transformations in Noble Metal Nanocatalysts

    SciTech Connect

    O Malis; C Byard; D Mott; B Wanjala; R Loukrakpam; J Luo; C Zhong

    2011-12-31

    In situ real-time x-ray diffraction was used to study temperature-induced structural changes of 1-5 nm Au, Pt, and AuPt nanocatalysts supported on silicon substrates. Synchrotron-based x-ray diffraction indicates that the as-synthesized Au and Au{sub 64}Pt{sub 36} nanoparticles have a non-crystalline structure, while the Pt nanoparticles have the expected cubic structure. The nanoparticles undergo dramatic structural changes at temperatures as low as 120 C. During low-temperature annealing, the Au and AuPt nanoparticles first melt and then immediately coalesce to form 4-5 nm crystalline structures. The Pt nanoparticles also aggregate but with limited intermediate melting. The detailed mechanisms of nucleation and growth, though, are quite different for the three types of nanoparticles. Most interestingly, solidification of high-density AuPt nanoparticles involves an unusual transient morphological transformation that affects only the surface of the particles. AuPt nanoparticles on silicon undergo partial phase segregation only upon annealing at extremely high temperatures (800 C).

  2. Recognition of a Phase-Sensitivity OTDR Sensing System Based on Morphologic Feature Extraction

    PubMed Central

    Sun, Qian; Feng, Hao; Yan, Xueying; Zeng, Zhoumo

    2015-01-01

    This paper proposes a novel feature extraction method for intrusion event recognition within a phase-sensitive optical time-domain reflectometer (Φ-OTDR) sensing system. Feature extraction of time domain signals in these systems is time-consuming and may lead to inaccuracies due to noise disturbances. The recognition accuracy and speed of current systems cannot meet the requirements of Φ-OTDR online vibration monitoring systems. In the method proposed in this paper, the time-space domain signal is used for feature extraction instead of the time domain signal. Feature vectors are obtained from morphologic features of time-space domain signals. A scatter matrix is calculated for the feature selection. Experiments show that the feature extraction method proposed in this paper can greatly improve recognition accuracies, with a lower computation time than traditional methods, i.e., a recognition accuracy of 97.8% can be achieved with a recognition time of below 1 s, making it is very suitable for Φ-OTDR system online vibration monitoring. PMID:26131671

  3. Recognition of a Phase-Sensitivity OTDR Sensing System Based on Morphologic Feature Extraction.

    PubMed

    Sun, Qian; Feng, Hao; Yan, Xueying; Zeng, Zhoumo

    2015-06-29

    This paper proposes a novel feature extraction method for intrusion event recognition within a phase-sensitive optical time-domain reflectometer (Φ-OTDR) sensing system. Feature extraction of time domain signals in these systems is time-consuming and may lead to inaccuracies due to noise disturbances. The recognition accuracy and speed of current systems cannot meet the requirements of Φ-OTDR online vibration monitoring systems. In the method proposed in this paper, the time-space domain signal is used for feature extraction instead of the time domain signal. Feature vectors are obtained from morphologic features of time-space domain signals. A scatter matrix is calculated for the feature selection. Experiments show that the feature extraction method proposed in this paper can greatly improve recognition accuracies, with a lower computation time than traditional methods, i.e., a recognition accuracy of 97.8% can be achieved with a recognition time of below 1 s, making it is very suitable for Φ-OTDR system online vibration monitoring.

  4. Experimental investigation on front morphology for two-phase flow in heterogeneous porous media

    NASA Astrophysics Data System (ADS)

    Heiß, V. I.; Neuweiler, I.; Ochs, S.; FäRber, A.

    2011-10-01

    In this work, we studied the influence of heterogeneities, fluid properties, and infiltration rates on front morphology during two-phase flow. In our experiments, a sand box, 40 cm × 60 cm × 1.2 cm, was packed with two different structures (either random or periodic) composed of 25% coarse material and 75% fine material. The infiltration process was characterized by the capillary number, Ca, and the viscosity ratio, M, between the fluids. The displacing and the displaced fluid had the same densities, such that gravity effects could be neglected. Similar to the pore scale, the stability of the front depends on the relation between M and Ca. However, on the scale under study, depending on the structure, zones of immobilized wetting fluid developed during drainage. The lifetime of these zones depended on the flow regime. Here we show that immobilized zones have an influence on the length of the transition zone, which could lead to a different time behavior than for that of the front width.

  5. Manganese oxide phases and morphologies: A study on calcination temperature and atmospheric dependence

    PubMed Central

    Fenske, Daniela; Bardenhagen, Ingo; Westphal, Anne; Knipper, Martin; Plaggenborg, Thorsten; Kolny-Olesiak, Joanna; Parisi, Jürgen

    2015-01-01

    Summary Manganese oxides are one of the most important groups of materials in energy storage science. In order to fully leverage their application potential, precise control of their properties such as particle size, surface area and Mnx + oxidation state is required. Here, Mn3O4 and Mn5O8 nanoparticles as well as mesoporous α-Mn2O3 particles were synthesized by calcination of Mn(II) glycolate nanoparticles obtained through an economical route based on a polyol synthesis. The preparation of the different manganese oxides via one route facilitates assigning actual structure–property relationships. The oxidation process related to the different MnOx species was observed by in situ X-ray diffraction (XRD) measurements showing time- and temperature-dependent phase transformations occurring during oxidation of the Mn(II) glycolate precursor to α-Mn2O3 via Mn3O4 and Mn5O8 in O2 atmosphere. Detailed structural and morphological investigations using transmission electron microscopy (TEM) and powder XRD revealed the dependence of the lattice constants and particle sizes of the MnOx species on the calcination temperature and the presence of an oxidizing or neutral atmosphere. Furthermore, to demonstrate the application potential of the synthesized MnOx species, we studied their catalytic activity for the oxygen reduction reaction in aprotic media. Linear sweep voltammetry revealed the best performance for the mesoporous α-Mn2O3 species. PMID:25671151

  6. An interface tracking method applied to morphological evolution during phase change

    NASA Technical Reports Server (NTRS)

    Shyy, W.; Udaykumar, H. S.; Liang, S.-J.

    1992-01-01

    The focus of this work is the numerical simulation of interface motion during solidification of pure materials. First, the applicability of the oft-used quasi-stationary approximation for interface motion is assessed. It is seen that such an approximation results in poor accuracy for nontrivial Stefan numbers. Solution of the full set of equations including grid movement terms yields close agreement with analytical results. Next, a generic interface tracking procedure is designed, which overcomes restrictions of single-valuedness of the interface imposed by commonly used mapping methods. This method incorporates with ease interface phenomena involving curvature, which assume importance at the smaller scales of a deformed interface. The method is then applied to study the development of a morphologically unstable phase interface. The issue of appropriate scaling has been addressed. The Gibbs-Thomson effect for curved interfaces has been included. The evolution of the interface, with the competing mechanisms of undercooling and surface tension is found to culminate in tip-splitting, cusp formation and persistent cellular development.

  7. Effects of Obesity on Cardiovascular Hemodynamics, Cardiac Morphology, and Ventricular Function.

    PubMed

    Alpert, Martin A; Omran, Jad; Bostick, Brian P

    2016-12-01

    Obesity produces a variety of hemodynamic alterations that may cause changes in cardiac morphology which predispose to left and right ventricular dysfunction. Various neurohormonal and metabolic alterations commonly associated with obesity may contribute to these abnormalities of cardiac structure and function. These changes in cardiovascular hemodynamics, cardiac morphology, and ventricular function may, in severely obese patients, predispose to heart failure, even in the absence of other forms of heart disease (obesity cardiomyopathy). In normotensive obese patients, cardiac involvement is commonly characterized by elevated cardiac output, low peripheral vascular resistance, and increased left ventricular (LV) end-diastolic pressure. Sleep-disordered breathing may lead to pulmonary arterial hypertension and, in association with left heart failure, may contribute to elevation of right heart pressures. These alterations, in association with various neurohormonal and metabolic abnormalities, may produce LV hypertrophy; impaired LV diastolic function; and less commonly, LV systolic dysfunction. Many of these alterations are reversible with substantial voluntary weight loss.

  8. Functional morphology and structural characteristics of wings of the ladybird beetle, Coccinella septempunctata (L.).

    PubMed

    Xiang, Jinwu; Du, Jianxun; Li, Daochun; Zhen, Chong

    2016-06-01

    In recent years, the surface morphology and microstructure of ladybird (Coccinella septempunctata) wings have been used to help design the flapping-wing micro air vehicle (FWMAV). In this study, scanning electron microscopy (SEM) was used to verify the functional roles of the ladybird forewing and hindwing. Surface morphology and the cross-sectional microstructure of the wings are presented. Detailed morphology of ladybird forewings was observed using atomic force microscopy (AFM) and the composition of the wings was characterized using Fourier transformed infrared spectroscopy (FTIR). The ladybird forewing may possess different performance characteristics than the beetle, Allomyrina dichotoma. Additionally, the circular holes in the forewing might be important for decreasing the weight of the forewing and to satisfy requirements of mechanical behavior. Microsc. Res. Tech. 79:550-556, 2016. © 2016 Wiley Periodicals, Inc.

  9. Potential energy function information from quantum phase shift using the variable phase method.

    PubMed

    Lemes, Nelson H T; Braga, João P; Alves, Márcio O; Costa, Éderson D'M

    2014-07-01

    The present work discusses quantum phase shift sensitivity analysis with respect to the potential energy function. A set of differential equations for the functional derivative of the quantum phase shift with respect to the potential energy function was established and coupled with the variable phase equation. This set of differential equations provides a simple, exact and straightforward way to establish the sensitivity matrix. The present procedure is easier to use than the finite difference approach, in which several direct problems have to be addressed. Furthermore, integration of the established equations can be used to demonstrate how the sensitivity phase shift is accumulated as a function of the interatomic distance. The potential energy function was refined to produce a better quality function. The average error on the phase shift decreased from 9.8% in the original potential function to 0.13% in the recovered potential. The present procedure is an important initial step for further work towards recovering potential energy functions in upper dimensions or to recovering this function from cross sections.

  10. Comparative Morphology of Premolar Foramen in Lagomorphs (Mammalia: Glires) and Its Functional and Phylogenetic Implications

    PubMed Central

    Fostowicz-Frelik, Łucja; Meng, Jin

    2013-01-01

    Lagomorphs (a group that consists of pikas, hares, rabbits and allies) are notable for their conservative morphology retained for most of their over 50 million years evolutionary history. On the other hand, their remarkable morphological uniformity partly stems from a considerable number of homoplasies in cranial and dental structures that hamper phylogenetic analyses. The premolar foramen, an opening in the palate of lagomorphs, has been characterized as an important synapomorphy of one clade, Ochotonidae (pikas). Within Lagomorpha, however, its phylogenetic distribution is much wider, the foramen being present not only in all ochotonids but also in leporids and stem taxa; its morphology and incidence also varies considerably across the order, even intraspecifically. In this study, we provide a broad survey of the taxonomic distribution of the premolar foramen in extant and fossil Lagomorpha and describe in detail the morphological variation of this character within the group. Micro-computed tomography was used to examine the hard palate and infraorbital groove morphology in Poelagus (Leporidae) and Ochotona. Scans revealed the course and contacts of the canal behind the premolar foramen and structural differences between the two crown clades. We propose that the premolar foramen has evolved independently in several lineages of Lagomorpha, and we discuss development and function of this foramen in the lagomorph skull. This study shows the importance of comprehensive studies on phylogenetically informative non-dental characters in Lagomorpha. PMID:24278178

  11. The role of foot morphology on foot function in diabetic subjects with or without neuropathy.

    PubMed

    Guiotto, Annamaria; Sawacha, Zimi; Guarneri, Gabriella; Cristoferi, Giuseppe; Avogaro, Angelo; Cobelli, Claudio

    2013-04-01

    The aim of this study was to investigate the role of foot morphology, related with respect to diabetes and peripheral neuropathy in altering foot kinematics and plantar pressure during gait. Healthy and diabetic subjects with or without neuropathy with different foot types were analyzed. Three dimensional multisegment foot kinematics and plantar pressures were assessed on 120 feet: 40 feet (24 cavus, 20 with valgus heel and 11 with hallux valgus) in the control group, 80 feet in the diabetic (25 cavus 13 with valgus heel and 13 with hallux valgus) and the neuropathic groups (28 cavus, 24 with valgus heel and 18 with hallux valgus). Subjects were classified according to their foot morphology allowing further comparisons among the subgroups with the same foot morphology. When comparing neuropathic subjects with cavus foot, valgus heel with controls with the same foot morphology, important differences were noticed: increased dorsiflexion and peak plantar pressure on the forefoot (P<0.05), decreased contact surface on the hindfoot (P<0.03). While results indicated the important role of foot morphology in altering both kinematics and plantar pressure in diabetic subjects, diabetes appeared to further contribute in altering foot biomechanics. Surprisingly, all the diabetic subjects with normal foot arch or with valgus hallux were no more likely to display significant differences in biomechanics parameters than controls. This data could be considered a valuable support for future research on diabetic foot function, and in planning preventive interventions.

  12. Functional morphology and comparative anatomy of appendicular musculature in Cuban Anolis lizards with different locomotor habits.

    PubMed

    Anzai, Wataru; Omura, Ayano; Diaz, Antonio Cadiz; Kawata, Masakado; Endo, Hideki

    2014-07-01

    We examined the diversity of the musculoskeletal morphology in the limbs of Anolis lizards with different habitats and identified variations in functional and morphological adaptations to different ecologies or behaviors. Dissection and isolation of 40 muscles from the fore- and hindlimbs of five species of Anolis were performed, and the muscle mass and length of the moment arm were compared after body size effects were removed. Ecologically and behaviorally characteristic morphological differences were observed in several muscles. Well-developed hindlimb extensors were observed in ground-dwelling species, A. sagrei and A. bremeri, and were considered advantageous for running, whereas adept climber species possessed expanded femoral retractors for weight-bearing during climbing. Moreover, morphological variations were observed among arboreal species. Wider excursions of the forelimb joint characterized A. porcatus, presumably enabling branch-to-branch locomotion, while A. equestris and A. angusticeps possessed highly developed adductor muscles for grasping thick branches or twigs. These findings suggest divergent evolution of musculoskeletal characteristic in the limbs within the genus Anolis, with correlations observed among morphological traits, locomotor performance, and habitat uses.

  13. Oscillatory phase coupling coordinates anatomically dispersed functional cell assemblies.

    PubMed

    Canolty, Ryan T; Ganguly, Karunesh; Kennerley, Steven W; Cadieu, Charles F; Koepsell, Kilian; Wallis, Jonathan D; Carmena, Jose M

    2010-10-05

    Hebb proposed that neuronal cell assemblies are critical for effective perception, cognition, and action. However, evidence for brain mechanisms that coordinate multiple coactive assemblies remains lacking. Neuronal oscillations have been suggested as one possible mechanism for cell assembly coordination. Prior studies have shown that spike timing depends upon local field potential (LFP) phase proximal to the cell body, but few studies have examined the dependence of spiking on distal LFP phases in other brain areas far from the neuron or the influence of LFP-LFP phase coupling between distal areas on spiking. We investigated these interactions by recording LFPs and single-unit activity using multiple microelectrode arrays in several brain areas and then used a unique probabilistic multivariate phase distribution to model the dependence of spike timing on the full pattern of proximal LFP phases, distal LFP phases, and LFP-LFP phase coupling between electrodes. Here we show that spiking activity in single neurons and neuronal ensembles depends on dynamic patterns of oscillatory phase coupling between multiple brain areas, in addition to the effects of proximal LFP phase. Neurons that prefer similar patterns of phase coupling exhibit similar changes in spike rates, whereas neurons with different preferences show divergent responses, providing a basic mechanism to bind different neurons together into coordinated cell assemblies. Surprisingly, phase-coupling-based rate correlations are independent of interneuron distance. Phase-coupling preferences correlate with behavior and neural function and remain stable over multiple days. These findings suggest that neuronal oscillations enable selective and dynamic control of distributed functional cell assemblies.

  14. Function dictates the phase dependence of vision during human locomotion.

    PubMed

    Logan, David; Ivanenko, Yuri P; Kiemel, Tim; Cappellini, Germana; Sylos-Labini, Francesca; Lacquaniti, Francesco; Jeka, John J

    2014-07-01

    In human and animal locomotion, sensory input is thought to be processed in a phase-dependent manner. Here we use full-field transient visual scene motion toward or away from subjects walking on a treadmill. Perturbations were presented at three phases of walking to test 1) whether phase dependence is observed for visual input and 2) whether the nature of phase dependence differs across body segments. Results demonstrated that trunk responses to approaching perturbations were only weakly phase dependent and instead depended primarily on the delay from the perturbation. Recording of kinematic and muscle responses from both right and left lower limb allowed the analysis of six distinct phases of perturbation effects. In contrast to the trunk, leg responses were strongly phase dependent. Leg responses during the same gait cycle as the perturbation exhibited gating, occurring only when perturbations were applied in midstance. In contrast, during the postperturbation gait cycle, leg responses occurred at similar response phases of the gait cycle over a range of perturbation phases. These distinct responses reflect modulation of trunk orientation for upright equilibrium and modulation of leg segments for both hazard accommodation/avoidance and positional maintenance on the treadmill. Overall, these results support the idea that the phase dependence of responses to visual scene motion is determined by different functional tasks during walking.

  15. [Morphology, ultrastructure and function of glycosylation-modified chilled blood platelets].

    PubMed

    Guo, Yong; Han, Ying; Quan, Guo-Bo; Liu, Min-Xia; Liu, An

    2008-04-01

    The glycosylation of platelets may prolong their life-span when being transfused after preservation under 4 degrees C, therefore this study was aimed to investigate the effect of glycosylation on morphology, ultrastructure, function and membrane glycoprotein of platelets. The experiments were divided into 3 groups: group preserved in room temperature (RT group), group preserved in 4 degrees C (4T group) and group UDP-Gal glycosylated and preserved in 4 degrees C (U+4T group). The binding rate of RCA I lectin and expression of platelet surface markers CD62P, CD42b were determined by flow cytometry. Morphology and ultrastructure of platelets were observed by light microscopy, scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Platelets aggregation was detected by aggregometer. The results showed that the binding rate of RCAI in U+4T group significantly higher than that in RT group (p<0.01), no obvious changes was found in ultrastructure of glycosylated platelets, as compared with fresh platelets. Some morphologic changes, such as pseudopodium could be observed in 4T group. The aggregation rate of platelets in U+4T group reached to 50% of RT group. The expression levels of CD42b and CD62P, and the binding rate of annexin V in U+4T group were not significantly different from that in RT group. It is concluded that UDP-Gal can effectively cause galactosylation of platelets, and the platelets modified with UDP-Gal remain normal morphology, ultrastructure and function.

  16. Covalent functionalization of monolayered transition metal dichalcogenides by phase engineering.

    PubMed

    Voiry, Damien; Goswami, Anandarup; Kappera, Rajesh; e Silva, Cecilia de Carvalho Castro; Kaplan, Daniel; Fujita, Takeshi; Chen, Mingwei; Asefa, Tewodros; Chhowalla, Manish

    2015-01-01

    Chemical functionalization of low-dimensional materials such as nanotubes, nanowires and graphene leads to profound changes in their properties and is essential for solubilizing them in common solvents. Covalent attachment of functional groups is generally achieved at defect sites, which facilitate electron transfer. Here, we describe a simple and general method for covalent functionalization of two-dimensional transition metal dichalcogenide nanosheets (MoS₂, WS₂ and MoSe₂), which does not rely on defect engineering. The functionalization reaction is instead facilitated by electron transfer between the electron-rich metallic 1T phase and an organohalide reactant, resulting in functional groups that are covalently attached to the chalcogen atoms of the transition metal dichalcogenide. The attachment of functional groups leads to dramatic changes in the optoelectronic properties of the material. For example, we show that it renders the metallic 1T phase semiconducting, and gives it strong and tunable photoluminescence and gate modulation in field-effect transistors.

  17. Multi-Scale Morphological Analysis of Conductance Signals in Vertical Upward Gas-Liquid Two-Phase Flow

    NASA Astrophysics Data System (ADS)

    Lian, Enyang; Ren, Yingyu; Han, Yunfeng; Liu, Weixin; Jin, Ningde; Zhao, Junying

    2016-11-01

    The multi-scale analysis is an important method for detecting nonlinear systems. In this study, we carry out experiments and measure the fluctuation signals from a rotating electric field conductance sensor with eight electrodes. We first use a recurrence plot to recognise flow patterns in vertical upward gas-liquid two-phase pipe flow from measured signals. Then we apply a multi-scale morphological analysis based on the first-order difference scatter plot to investigate the signals captured from the vertical upward gas-liquid two-phase flow loop test. We find that the invariant scaling exponent extracted from the multi-scale first-order difference scatter plot with the bisector of the second-fourth quadrant as the reference line is sensitive to the inhomogeneous distribution characteristics of the flow structure, and the variation trend of the exponent is helpful to understand the process of breakup and coalescence of the gas phase. In addition, we explore the dynamic mechanism influencing the inhomogeneous distribution of the gas phase in terms of adaptive optimal kernel time-frequency representation. The research indicates that the system energy is a factor influencing the distribution of the gas phase and the multi-scale morphological analysis based on the first-order difference scatter plot is an effective method for indicating the inhomogeneous distribution of the gas phase in gas-liquid two-phase flow.

  18. Drift-Diffusion Studies of Compositional Morphology in Bulk Heterojunctions: The Role of the Mixed Phase in Photovoltaic Performance

    NASA Astrophysics Data System (ADS)

    Finck, Benjamin Y.; Schwartz, Benjamin J.

    2016-11-01

    The active layers of most organic photovoltaic (OPV) devices are constructed from a blend of two organic compounds. The two materials spontaneously segregate into pure-component phases during device fabrication, creating a bicontinuous network of conduction pathways that are selective for electron or hole charge carriers. The morphological distribution of these materials within the active layer has long been known to influence charge transport and resulting device performance. In addition to the two pure-component phases present in these devices, a third, mixed-composition phase exists at the interface between the two pure phases. The exact effects of this mixed-composition phase on OPV device performance are not well understood, although it is argued that the presence of a mixed phase is necessary for optimal device operation. In this paper, we probe the effects of having a mixed-composition interfacial phase on the performance and charge-transport characteristics of OPV devices through a series of drift-diffusion model simulations. We start with set of model morphologies with only pure-component phases and then introduce an interfacial mixed phase in a controllable fashion. Our simulations show that a modest amount of mixing initially improves device efficiency by reducing the tortuosity of the device's conduction pathways and easing morphological traps. However, an excessive amount of mixing can actually degrade high-conductivity pathways, reducing photovoltaic performance. The point at which mixing switches from being beneficial to detrimental to OPV performance depends on the average domain size of a device's morphology. Devices with smaller feature sizes are more susceptible to the debilitating effects of overmixing, so that the presence of a mixed phase may either raise power-conversion efficiency by as much as 100% or lower it by as much as 50%, depending on the average domain size and the extent of mixing. These trends suggest that variations in the amount

  19. Growth-Phase-Specific Modulation of Cell Morphology and Gene Expression by an Archaeal Histone Protein

    PubMed Central

    Dulmage, Keely A.; Todor, Horia

    2015-01-01

    ABSTRACT In all three domains of life, organisms use nonspecific DNA-binding proteins to compact and organize the genome as well as to regulate transcription on a global scale. Histone is the primary eukaryotic nucleoprotein, and its evolutionary roots can be traced to the archaea. However, not all archaea use this protein as the primary DNA-packaging component, raising questions regarding the role of histones in archaeal chromatin function. Here, quantitative phenotyping, transcriptomic, and proteomic assays were performed on deletion and overexpression mutants of the sole histone protein of the hypersaline-adapted haloarchaeal model organism Halobacterium salinarum. This protein is highly conserved among all sequenced haloarchaeal species and maintains hallmark residues required for eukaryotic histone functions. Surprisingly, despite this conservation at the sequence level, unlike in other archaea or eukaryotes, H. salinarum histone is required to regulate cell shape but is not necessary for survival. Genome-wide expression changes in histone deletion strains were global, significant but subtle in terms of fold change, bidirectional, and growth phase dependent. Mass spectrometric proteomic identification of proteins from chromatin enrichments yielded levels of histone and putative nucleoid-associated proteins similar to those of transcription factors, consistent with an open and transcriptionally active genome. Taken together, these data suggest that histone in H. salinarum plays a minor role in DNA compaction but important roles in growth-phase-dependent gene expression and regulation of cell shape. Histone function in haloarchaea more closely resembles a regulator of gene expression than a chromatin-organizing protein like canonical eukaryotic histone. PMID:26350964

  20. Measurements of morphology and refractive indexes on human downy hairs using three-dimensional quantitative phase imaging.

    PubMed

    Lee, SangYun; Kim, Kyoohyun; Lee, Yuhyun; Park, Sungjin; Shin, Heejae; Yang, Jongwon; Ko, Kwanhong; Park, HyunJoo; Park, YongKeun

    2015-01-01

    We present optical measurements of morphology and refractive indexes (RIs) of human downy arm hairs using three-dimensional (3-D) quantitative phase imaging techniques. 3-D RI tomograms and high-resolution two-dimensional synthetic aperture images of individual downy arm hairs were measured using a Mach–Zehnder laser interferometric microscopy equipped with a two-axis galvanometer mirror. From the measured quantitative images, the RIs and morphological parameters of downy hairs were noninvasively quantified including the mean RI, volume, cylinder, and effective radius of individual hairs. In addition, the effects of hydrogen peroxide on individual downy hairs were investigated.

  1. Measurements of morphology and refractive indexes on human downy hairs using three-dimensional quantitative phase imaging

    NASA Astrophysics Data System (ADS)

    Lee, SangYun; Kim, Kyoohyun; Lee, Yuhyun; Park, Sungjin; Shin, Heejae; Yang, Jongwon; Ko, Kwanhong; Park, HyunJoo; Park, YongKeun

    2015-11-01

    We present optical measurements of morphology and refractive indexes (RIs) of human downy arm hairs using three-dimensional (3-D) quantitative phase imaging techniques. 3-D RI tomograms and high-resolution two-dimensional synthetic aperture images of individual downy arm hairs were measured using a Mach-Zehnder laser interferometric microscopy equipped with a two-axis galvanometer mirror. From the measured quantitative images, the RIs and morphological parameters of downy hairs were noninvasively quantified including the mean RI, volume, cylinder, and effective radius of individual hairs. In addition, the effects of hydrogen peroxide on individual downy hairs were investigated.

  2. Correlation of Bulk Dielectric and Piezoelectric Properties to the Local Scale Phase Transformations, Domain Morphology, and Crystal Structure Modified

    SciTech Connect

    Priya, Shashank; Viehland, Dwight

    2014-12-14

    Three year program entitled “Correlation of bulk dielectric and piezoelectric properties to the local scale phase transformations, domain morphology, and crystal structure in modified lead-free grain-textured ceramics and single crystals” was supported by the Department of Energy. This was a joint research program between D. Viehland and S. Priya at Virginia Tech. Single crystal and textured ceramics have been synthesized and characterized. Our goals have been (i) to conduct investigations of lead-free piezoelectric systems to establish the local structural and domain morphologies that result in enhanced properties, and (ii) to synthesize polycrystalline and grain oriented ceramics for understanding the role of composition, microstructure, and anisotropy

  3. Anatase-TiO2 Nanomaterials: Morphological/Size Dependence of the Crystallization and Phase Behavior Phenomena

    SciTech Connect

    Fernandez-Garcia,M.; Wang, X.; Belver, C.; Hanson, J.; Rodriguez, J.

    2007-01-01

    Nanoparticulated TiO{sub 2} materials with anatase structure were synthesized by using a microemulsion method. Three different syntheses with varying surfactant-to-water molar ratio ({omega}) were used to obtain amorphous solid precipitates at room temperature. The structural characteristics of these solid precursors were studied by using X-ray absorption structure (X-ray absorption near-edge structure and extended X-ray absorption fine structure) and Raman spectroscopies, which showed that all lack 3D (tridimensional) order but contain a different degree of 2D-confined connectivity. While heating such solid precursors under dry air, marked differences appeared in the phase behavior; the onset temperature for anatase crystallization increases ca. 150 {sup o}C while the {omega} parameter decreases and only one of the samples shows the anatase-to-rutile transformation below 900 {sup o}C. In all cases, the crystallization of the anatase structure does not follow a traditional nucleation and growth mechanism and its analysis using the Avrami formalism gives conclusive evidence of a surface nucleation-dominated process. This appears as a distinctive feature of anatase-TiO{sub 2} nanomaterials, far from the corresponding behavior of microsized or bulk materials. After nucleation, the grain growth of anatase nanoparticles was found to follow the kinetic equation D{sup 2}-D{sub 0}{sup 2} = k{sub 0} exp(-E{sub a}/RT), where the activation energy is a function of several structural properties of the solid materials mainly related to the hydration characteristics of the surface layer. A combined in situ X-ray diffraction/Raman/infrared study aimed to unveil the physical basis of the phase behavior and to interpret key variables allowing control of the crystallization mechanism and morphological properties, particularly primary particle size, in the nanometer regime.

  4. Exact probability-density function for phase-measurement interferometry

    NASA Astrophysics Data System (ADS)

    Ho, Keang-Po; Kahn, Joseph M.

    1995-09-01

    Conventional analyses of the accuracy of phase-measurement interferometry derive a figure of merit that is either a variance or a signal-to-noise ratio. We derive the probability-density function of the phase-measurement output, so that the measurement confidence interval can be determined. We include both laser phase noise and additive Gaussian noise, and we consider both unmodulated interferometers and those employing phase or frequency modulation. For both unmodulated and modulated interferometers the confidence interval can be obtained by numerical integration of the probability-density function. For the modulated interferometer we derive a series summation for the confidence interval. For both unmodulated and modulated interferometers we derive approximate analytical expressions for the confidence interval, which we show to be extremely accurate at high signal-to-noise ratios.

  5. Comparative functional morphology of the masticatory apparatus in the long-snouted crocodiles.

    PubMed

    Endo, H; Aoki, R; Taru, H; Kimura, J; Sasaki, M; Yamamoto, M; Arishima, K; Hayashi, Y

    2002-08-01

    The masticatory muscles and their related structures of the skull were observed in the Indian gavial (Gavialis gangeticus), the false gavial (Tomistoma schlegelii), and the African slender-snouted crocodile (Mecistops cataphractus) to detail some morphological differences in comparison with the other crocodile species, and to compare and elucidate the functional strategy of themasticatory apparatus in these long-snouted species. The Musculus pterygoideus posterior was relatively smaller in the three species compared with many short-snouted crocodiles. It suggests that the masticatory power in fish-eating long-snouted species is not so high as in the short-snouted crocodiles, while the masticatory muscles were morphologically different among the three long-snouted species as follows. The M. pterygoideus posterior of the false gavial was extended in the lateral side of the lower jaw unlike the Indian gavial. The M. pseudotemporalis and the Fenestra supratemporalis were largely developed in the Indian gavial, however we suggest that the other two species possess the weak bundles in this muscle. The false gavial and the African slender-snouted crocodile have the pterygoid bone well-developed extending dorso-ventrally and it is suggested that the M. adductor mandibulae posterior attached to the pterygoid bone may be much larger than the Indian gavial. These data morphologically clarify the masticatory mechanism in the long-snouted crocodiles different from the short-snouted species, and demonstrate that the evolutional strategy to share the functional role in the masticatory muscles have been differently established between the Indian gavial and the other two species. We also obtained the morphological data in the fossil skull of the Machikane crocodile (Toyotamaphymeia machikanense) and concluded from the fossil characters that the considerable developments of the M.pterygoideus posterior and the M.pseudotemporalis in this species had not morphologically been

  6. Gender identification of Caspian Terns using external morphology and discriminant function analysis

    USGS Publications Warehouse

    Ackerman, J.T.; Takekawa, J.Y.; Bluso, J.D.; Yee, J.L.; Eagles-Smith, C. A.

    2008-01-01

    Caspian Tern (Sterna caspia) plumage characteristics are sexually monochromatic and gender cannot easily be distinguished in the field without extensive behavioral observations. We assessed sexual size dimorphism and developed a discriminant function to assign gender in Caspian Terns based on external morphology. We collected and measured Caspian Terns in San Francisco Bay, California, and confirmed their gender based on necropsy and genetic analysis. Of the eight morphological measurements we examined, only bill depth at the gonys and head plus bill length differed between males and females with males being larger than females. A discriminant function using both bill depth at the gonys and head plus bill length accurately assigned gender of 83% of terns for which gender was known. We improved the accuracy of our discriminant function to 90% by excluding individuals that had less than a 75% posterior probability of correctly being assigned to gender. Caspian Terns showed little sexual size dimorphism in many morphometries, but our results indicate they can be reliably assigned to gender in the field using two morphological measurements.

  7. From Newborn to Senescence Morphological and Functional Remodeling Leads to Increased Contractile Capacity of Arteries.

    PubMed

    Ivic, Ivan; Vamos, Zoltan; Cseplo, Peter; Koller, Akos

    2017-04-01

    Aging induces substantial morphological and functional changes in vessels. We hypothesized that due to morphological remodeling the total contractile forces of arteries increase, especially in older age as a function of age. Mean arterial blood pressure of rats and morphological and functional characteristics of isolated carotid arteries rats, from newborn to senescent, were assessed. The arterial blood pressure of rats increased significantly from 0.25 to the age of 6 months, and then it reached a level, which was maintained until age of 30 months. Wall lumen and wall thickness increased with age, mostly due to media (smooth muscle) thickening, whereas wall tension gradually reduced with age. Contractions of arteries to nonreceptor-mediated vasomotor agent (KCl, 60mM) increased in three consecutive age groups, whereas contractility first increased (until 2 months), then it did not change further with aging. Norepinephrine-induced contractions initially increased in young age and then did not change further in older age. These findings suggest that during normal aging due to remodeling of arterial wall (smooth muscle) the contractile capacity of arteries increases, which seems to be independent from systemic blood pressure. Thus, arterial remodeling can favor the development of increased circulatory resistance in older age.

  8. Testing hypotheses of convergence with multivariate data: morphological and functional convergence among herbivorous lizards.

    PubMed

    Stayton, C Tristan

    2006-04-01

    Despite its importance to evolutionary theory, convergence remains an understudied phenomenon and is usually investigated using qualitative data. This paper advances a new, multidimensional view of convergence. Three patterns indicative of convergence are discussed, and techniques to discover and test convergent patterns in a quantitative framework are developed. These concepts and methods are applied to a dataset of digitized coordinates on 1554 lizard skulls and 1292 lower jaws to test hypotheses of convergence among herbivorous lizards. Encompassing seven independent acquisitions of herbivory, this lizard sample provides an ideal natural experiment for exploring ideas of convergence among different systems (here, morphological and functional). Three related questions are addressed: (1) Do herbivorous lizards show evidence of convergence in skull and lower jaw morphology? (2) What, if any, is the morphospace pattern associated with this convergence? (3) Is it possible to predict the direction of convergence using functional models? Relative warp analysis and permutation tests reveal that the skulls and lower jaws of herbivorous lizards do show evidence of convergence. Herbivore skulls deviate from their carnivorous or omnivorous sister groups toward the same area of morphospace. Without a phylogenetic perspective, this pattern would not be recognizable. Lower jaws of herbivores are not convergent in morphology but are convergent in function: herbivores deviate away from their carnivorous sister groups toward higher values of mechanical advantage. These results illustrate the desirability of quantitative methods, informed by phylogenetic information, in the study of convergence.

  9. Assemblages: Functional units formed by cellular phase separation

    PubMed Central

    Wright, Peter E.

    2014-01-01

    The partitioning of intracellular space beyond membrane-bound organelles can be achieved with collections of proteins that are multivalent or contain low-complexity, intrinsically disordered regions. These proteins can undergo a physical phase change to form functional granules or other entities within the cytoplasm or nucleoplasm that collectively we term “assemblage.” Intrinsically disordered proteins (IDPs) play an important role in forming a subset of cellular assemblages by promoting phase separation. Recent work points to an involvement of assemblages in disease states, indicating that intrinsic disorder and phase transitions should be considered in the development of therapeutics. PMID:25179628

  10. A Comparison between Growth Morphology of "Eutectic" Cells/Dendrites and Single-Phase Cells/Dendrites

    NASA Technical Reports Server (NTRS)

    Tewari, S. N.; Raj, S. V.; Locci, I. E.

    2003-01-01

    Directionally solidified (DS) intermetallic and ceramic-based eutectic alloys with an in-situ composite microstructure containing finely distributed, long aspect ratio, fiber, or plate reinforcements are being seriously examined for several advanced aero-propulsion applications. In designing these alloys, additional solutes need to be added to the base eutectic composition in order to improve heir high-temperature strength, and provide for adequate toughness and resistance to environmental degradation. Solute addition, however, promotes instability at the planar liquid-solid interface resulting in the formation of two-phase eutectic "colonies." Because morphology of eutectic colonies is very similar to the single-phase cells and dendrites, the stability analysis of Mullins and Sekerka has been extended to describe their formation. Onset of their formation shows a good agreement with this approach; however, unlike the single-phase cells and dendrites, there is limited examination of their growth speed dependence of spacing, morphology, and spatial distribution. The purpose of this study is to compare the growth speed dependence of the morphology, spacing, and spatial distribution of eutectic cells and dendrites with that for the single-phase cells and dendrites.

  11. Morphological and Functional Differences between Athletes and Novices in Cortical Neuronal Networks

    PubMed Central

    Tan, Xiao-Ying; Pi, Yan-Ling; Wang, Jue; Li, Xue-Pei; Zhang, Lan-Lan; Dai, Wen; Zhu, Hua; Ni, Zhen; Zhang, Jian; Wu, Yin

    2017-01-01

    The cortical structural and functional differences in athletes and novices were investigated with a cross-sectional paradigm. We measured the gray matter volumes and resting-state functional connectivity in 21 basketball players and 21 novices with magnetic resonance imaging (MRI) techniques. It was found that gray matter volume in the left anterior insula (AI), inferior frontal gyrus (IFG), inferior parietal lobule (IPL) and right anterior cingulate cortex (ACC), precuneus is greater in basketball players than that in novices. These five brain regions were selected as the seed regions for testing the resting-state functional connectivity in the second experiment. We found higher functional connectivity in default mode network, salience network and executive control network in basketball players compared to novices. We conclude that the morphology and functional connectivity in cortical neuronal networks in athletes and novices are different. PMID:28101012

  12. Morphological and Functional Differences between Athletes and Novices in Cortical Neuronal Networks.

    PubMed

    Tan, Xiao-Ying; Pi, Yan-Ling; Wang, Jue; Li, Xue-Pei; Zhang, Lan-Lan; Dai, Wen; Zhu, Hua; Ni, Zhen; Zhang, Jian; Wu, Yin

    2016-01-01

    The cortical structural and functional differences in athletes and novices were investigated with a cross-sectional paradigm. We measured the gray matter volumes and resting-state functional connectivity in 21 basketball players and 21 novices with magnetic resonance imaging (MRI) techniques. It was found that gray matter volume in the left anterior insula (AI), inferior frontal gyrus (IFG), inferior parietal lobule (IPL) and right anterior cingulate cortex (ACC), precuneus is greater in basketball players than that in novices. These five brain regions were selected as the seed regions for testing the resting-state functional connectivity in the second experiment. We found higher functional connectivity in default mode network, salience network and executive control network in basketball players compared to novices. We conclude that the morphology and functional connectivity in cortical neuronal networks in athletes and novices are different.

  13. Functional phases and angular momentum characteristics of Tkatchev and Kovacs.

    PubMed

    Irwin, Gareth; Exell, Timothy A; Manning, Michelle L; Kerwin, David G

    2017-03-01

    Understanding the technical requirements and underlying biomechanics of complex release and re-grasp skills on high bar allows coaches and scientists to develop safe and effective training programmes. The aim of this study was to examine the differences in the functional phases between the Tkatchev and Kovacs skills and to explain how the angular momentum demands are addressed. Images of 18 gymnasts performing 10 Tkatchevs and 8 Kovacs at the Olympic Games were recorded (50 Hz), digitised and reconstructed (3D Direct Linear Transformation). Orientation of the functional phase action, defined by the rapid flexion to extension of the shoulders and extension to flexion of the hips as the performer passed through the lower vertical, along with shoulder and hip angular kinematics, angular momentum and key release parameters (body angle, mass centre velocity and angular momentum about the mass centre and bar) were compared between skills. Expected differences in the release parameters of angle, angular momentum and velocity were observed and the specific mechanical requirement of each skill were highlighted. Whilst there were no differences in joint kinematics, hip and shoulder functional phase were significantly earlier in the circle for the Tkatchev. These findings highlight the importance of the orientation of the functional phase in the preceding giant swing and provide coaches with further understanding of the critical timing in this key phase.

  14. Morphological and molecular evidence for functional organization along the rostrocaudal axis of the adult zebrafish intestine

    PubMed Central

    2010-01-01

    Background The zebrafish intestine is a simple tapered tube that is folded into three sections. However, whether the intestine is functionally similar along its length remains unknown. Thus, a systematic structural and functional characterization of the zebrafish intestine is desirable for future studies of the digestive tract and the intestinal biology and development. Results To characterize the structure and function of the adult zebrafish intestine, we divided the intestine into seven roughly equal-length segments, S1-S7, and systematically examined the morphology of the mucosal lining, histology of the epithelium, and molecular signatures from transcriptome analysis. Prominent morphological features are circumferentially-oriented villar ridges in segments S1-S6 and the absence of crypts. Molecular characterization of the transcriptome from each segment shows that segments S1-S5 are very similar while S6 and S7 unique. Gene ontology analyses reveal that S1-S5 express genes whose functions involve metabolism of carbohydrates, transport of lipids and energy generation, while the last two segments display relatively limited function. Based on comparative Gene Set Enrichment Analysis, the first five segments share strong similarity with human and mouse small intestine while S6 shows similarity with human cecum and rectum, and S7 with human rectum. The intestinal tract does not display the anatomical, morphological, and molecular signatures of a stomach and thus we conclude that this organ is absent from the zebrafish digestive system. Conclusions Our genome-wide gene expression data indicate that, despite the lack of crypts, the rostral, mid, and caudal portions of the zebrafish intestine have distinct functions analogous to the mammalian small and large intestine, respectively. Organization of ridge structures represents a unique feature of zebrafish intestine, though they produce similar cross sections to mammalian intestines. Evolutionary lack of stomach, crypts

  15. Light-induced morphological plasticity in the scleractinian coral Goniastrea pectinata and its functional significance

    NASA Astrophysics Data System (ADS)

    Ow, Y. X.; Todd, P. A.

    2010-09-01

    Environment-induced i.e., phenotypically plastic, changes in morphology, are potentially an important life-history component of sessile corals. Previous reciprocal transplant experiments have demonstrated depth-related responses in various coral species, but the potential adaptive significance is rarely investigated. To test for small-scale morphological plasticity in the massive coral Goniastrea pectinata Ehrenberg 1834, fragments from five colonies were reciprocally transplanted between two depths at Raffles Lighthouse (Pulau Satumu), Singapore. After 163 days, all fragments were collected, cleared of tissue, and examined. Reaction norms and multivariate analysis of variance describe light-induced changes in corallite architecture and genotype × environment interactions. In fragments transplanted to the shallow station, calices were deeper, and septa were shorter than in fragments transplanted to the deep station. To explore the functional significance of this plasticity, a two-dimensional model of corallite shape was constructed. The induced calice morphology of the shallow-water transplants was efficient at shading, possibly to protect tissue from excess radiation, whereas the calice morphology found in the deep-water transplants was more efficient at capturing light when irradiance was low.

  16. Morphology and ventilatory function of gills in the carpet shark family Parascylliidae (Elasmobranchii, Orectolobiformes).

    PubMed

    Goto, Tomoaki; Shiba, Yojiro; Shibagaki, Kazuhiro; Nakaya, Kazuhiro

    2013-06-01

    We examined gill morphology and ventilatory function in the carpet shark family Parascylliidae using 14 preserved specimens of Parascyllium ferrugineum, P. variolatum, P. collare and Cirrhoscyllium japonicum, and two live specimens of P. ferrugineum and P. variolatum. Morphological examinations revealed eight morphological characteristics related to the fifth gill, based on comparisons with other elasmobranchs, viz. large fifth gill slit without gill filaments, anatomical modifications in the fourth ceratobranchial cartilage and coraco-branchialis muscle, and the hypaxialis muscle associated with the fifth gill arch. Ventilation examinations using dyed seawater and prey items showed different water flows through the gill slits for respiration and prey-capture actions. For respiration, water sucked into the mouth was expelled equally through the first to fourth gill slits via a "double-pump" action, there being no involvement of the fifth gill slit. In prey-capture, however, water sucked into the mouth was discharged only via the widely opened fifth gill slit. This form of water flow is similar to that in other benthic suction-feeding sharks (e.g., Chiloscyllium plagiosum), except for the active water discharge by wide expansion and contraction of the fifth parabranchial cavity. The latter is dependent upon the morphological modifications of the fourth and fifth gill arches, derived phylogenetically as a mechanistic suction specialization in Parascylliidae.

  17. Nocturnality constrains morphological and functional diversity in the eyes of reef fishes

    PubMed Central

    2011-01-01

    Background Ambient light levels are often considered to drive the evolution of eye form and function. Diel activity pattern is the main mechanism controlling the visual environment of teleost reef fish, with day-active (diurnal) fish active in well-illuminated conditions, whereas night-active (nocturnal) fish cope with dim light. Physiological optics predicts several specific evolutionary responses to dim-light vision that should be reflected in visual performance features of the eye. Results We analyzed a large comparative dataset on morphological traits of the eyes in 265 species of teleost reef fish in 43 different families. The eye morphology of nocturnal reef teleosts is characterized by a syndrome that indicates better light sensitivity, including large relative eye size, high optical ratio and large, rounded pupils. Improved dim-light image formation comes at the cost of reduced depth of focus and reduction of potential accommodative lens movement. Diurnal teleost reef fish, released from the stringent functional requirements of dim-light vision have much higher morphological and optical diversity than nocturnal species, with large ranges of optical ratio, depth of focus, and lens accommodation. Conclusions Physical characteristics of the environment are an important factor in the evolution and diversification of the vertebrate eye. Both teleost reef fish and terrestrial amniotes meet the functional requirements of dim-light vision with a similar evolutionary response of morphological and optical modifications. The trade-off between improved dim-light vision and reduced optical diversity may be a key factor in explaining the lower trophic diversity of nocturnal reef teleosts. PMID:22098687

  18. Role of dopant counter-anion functionality in polyaniline salts/blends and implications to morphology

    SciTech Connect

    Hopkins, A.R.; Rasmussen, P.G.; Basheer, R.A.; Annis, B.K.; Wignall, G.D.

    1997-04-01

    Polyanilines are of particular current interest primarily due to their relative ease of synthesis, low cost and stable conductivity in air. The insulating, polyaniline emeraldine base (PANI-EB) form becomes electrically conducting by preferential protonation or doping the imine nitrogen sites to yield an electrically conducting polyaniline emeraldine salt (PANI-ES). In this paper, wide and small angle X-ray scattering techniques (i.e., WAXS and SAXS) and light microscopy are used to characterize the influence of the dopant`s structure on the morphology of both polyaniline salt and blend. In an attempt to modify the morphology of the PANI-ES, the authors have evaluated a number of doping acids (i.e., methane sulfonic acid (HMSA), butane sulfonic acid (HBSA), dodecyl benzene sulfonic acid (HDBSA) and camphor sulfonic acid (HCSA)) that vary in size and polarity to better understanding the role of the acid in PANI-ES`s morphology and the resulting electrical conductivity. The other goal was to investigate the effect of the counter-anion structure on the nature of the phase separated PANI-ES network. The shape of the PANI-ES network in the host polycaprolactam has important implications on the nature of conduction behavior and the final electrical conductivity of the blend.

  19. Morphological control of multihollow polymer latex particles through a controlled phase separation in the seeded emulsion polymerization.

    PubMed

    Li, Bingxin; Xu, Yongfei; Wang, Mozhen; Ge, Xuewu

    2013-12-03

    In this work, we first reported that the phase separation can take place both inside and outside of a multihollow-structured cross-linked seed microspheres swollen by styrene monomers in water during the radiation-induced seeded emulsion polymerization. The phase separation process in these two opposite directions will determine the morphology of final latex particles. First, sulfonated cross-linked polystyrene (SCPS) seed microspheres were swollen by styrene in water. Water will permeate into the SCPS seed microspheres during the swelling process, forced by the osmotic pressure produced by the strong hydrophilicity of the sulfonic acid groups. New aqueous phases are created and stabilized by the hydrophilic -SO3H groups, resulting in a multihollow structure of swollen SCPS seed microspheres. When the polymerization of styrene is induced by (60)Co γ-ray radiation, the phase separation of newly formed polystyrene phase will occur at the seed microsphere-water interface inside and/or outside of the SCPS seed microspheres through adjusting the diameter of seed microsphere, the content of cross-link agent, and the sulfonation degree of SCPS seed microspheres. As a result, SCPS latex particles with a variety of special morphologies, such as spherical multihollow, plum-like, and walnut-like latex particles were obtained. The results of this study provide not only a simple and interesting way to design and synthesize multihollow polymer latex particles with controllable surface morphologies but also a better understanding on phase separation mechanism during the swelling and polymerization of monomers in cross-linked amphiphilic polymer networks.

  20. The Functional Significance of Chiral Genitalia: Patterns of Asymmetry, Functional Morphology and Mating Success in the Praying Mantis Ciulfina baldersoni.

    PubMed

    Holwell, Gregory I; Kazakova, Olga; Evans, Felicity; O'Hanlon, James C; Barry, Katherine L

    2015-01-01

    Genital asymmetry is relatively common and widespread throughout the animal kingdom. The functional significance of genital asymmetry is however, poorly understood for most species. Male praying mantids of the genus Ciulfina are remarkable in possessing complex and directionally asymmetric genital phallomeres in some species, and chirally dimorphic/antisymmetric genitalia in others. Here we explore the chiral dimorphism in male genitalia of Ciulfina baldersoni which appear to exhibit genital antisymmetry. We test whether genital orientation influences mating success, copulation duration and the attachment duration of spermatophores. Additionally we investigate genital interactions between male and females using x-ray micro-computed tomography (micro-CT) and scanning electron microscopy (SEM). Lastly we assess whether genital asymmetry is associated with non-genital morphological asymmetry of a range of traits. Our results highlight the complex functional morphology of genitalia in this praying mantis species and yet demonstrate no functional difference between dextral and sinistral morphs other than the direction of attachment with both morphs enjoying equal levels of mating success. Chiral morphs also did not strongly associate with any other forms of asymmetry. We therefore conclude that genital chirality in Ciulfina baldersoni is a likely case of antisymmetry with no functional significance to genital orientation, and is likely to be selectively neutral.

  1. The Functional Significance of Chiral Genitalia: Patterns of Asymmetry, Functional Morphology and Mating Success in the Praying Mantis Ciulfina baldersoni

    PubMed Central

    Holwell, Gregory I.; Kazakova, Olga; Evans, Felicity; O’Hanlon, James C.; Barry, Katherine L.

    2015-01-01

    Genital asymmetry is relatively common and widespread throughout the animal kingdom. The functional significance of genital asymmetry is however, poorly understood for most species. Male praying mantids of the genus Ciulfina are remarkable in possessing complex and directionally asymmetric genital phallomeres in some species, and chirally dimorphic/antisymmetric genitalia in others. Here we explore the chiral dimorphism in male genitalia of Ciulfina baldersoni which appear to exhibit genital antisymmetry. We test whether genital orientation influences mating success, copulation duration and the attachment duration of spermatophores. Additionally we investigate genital interactions between male and females using x-ray micro-computed tomography (micro-CT) and scanning electron microscopy (SEM). Lastly we assess whether genital asymmetry is associated with non-genital morphological asymmetry of a range of traits. Our results highlight the complex functional morphology of genitalia in this praying mantis species and yet demonstrate no functional difference between dextral and sinistral morphs other than the direction of attachment with both morphs enjoying equal levels of mating success. Chiral morphs also did not strongly associate with any other forms of asymmetry. We therefore conclude that genital chirality in Ciulfina baldersoni is a likely case of antisymmetry with no functional significance to genital orientation, and is likely to be selectively neutral. PMID:26107629

  2. Functional morphology of the male caudal appendages of the damselfly Ischnura elegans (Zygoptera: Coenagrionidae).

    PubMed

    Willkommen, Jana; Michels, Jan; Gorb, Stanislav N

    2015-07-01

    Odonata are usually regarded as one of the most ancient extant lineages of winged insects. Their copulatory apparatus and mating behavior are unique among insects. Male damselflies use their caudal appendages to clasp the female's prothorax during both copulation and egg-laying and have a secondary copulatory apparatus for sperm transfer. Knowledge of the functional morphology of the male caudal appendages is the basis for understanding the evolution of these structures in Odonata and respective organs in other insects. However, it is still not exactly known how the zygopteran claspers work. In this study, we applied micro-computed tomography and a variety of microscopy techniques to examine the morphology, surface microstructure, cuticle material composition and muscle topography of the male caudal appendages of Ischnura elegans. The results indicate that the closing of the paraproctal claspers is mainly passive. This indirect closing mechanism is very likely supported by high proportions of the elastic protein resilin present in the cuticle of the paraproctal bases. In addition, the prothoracic morphology of the female plays an important role in the indirect closing of the male claspers. Our data indicate that both structures - the male claspers and the female prothoracic hump - function together like a snap-fastener.

  3. Morphology and functions of astrocytes cultured on water-repellent fractal tripalmitin surfaces.

    PubMed

    Hu, Wei-wei; Wang, Zhe; Zhang, Shan-shan; Jiang, Lei; Zhang, Jing; Zhang, Xiangnan; Lei, Qun-fang; Park, Hyun-Joo; Fang, Wen-jun; Chen, Zhong

    2014-08-01

    In the brain, astrocytes play an essential role with their multiple functions and sophisticated structure, as surrounded by a fractal environment which has not been available in our traditional cell culture. Water-repellent fractal tripalmitin (PPP) surfaces can imitate the fractal environment in vivo, so the morphology and biochemical characterization of astrocytes on these surfaces are examined. Water-repellent fractal PPP surface can induce astrocytes to display sophisticated morphology with smaller size of cell area, longer and finer filopodium-like processes, and higher morphological complexity. The super water-repellent fractal PPP surface with water contact angle of 150°∼160° produces the maximal effects compared with other surfaces at lower water contact angles. The trends of characteristic protein expression, including that of nestin, vimentin, GFAP and glutamine synthetase, for astrocytes cultured on super water-repellent fractal PPP surfaces approximate more to in vivo pattern. The super water-repellent PPP surface also render astrocytes to perform more pronounced promotion of neurogenesis by increasing the release of nerve growth factor in a co-culture system. Altogether, our results suggest that the super water-repellent fractal PPP surface facilitates the astrocytes to mimic their in vivo performance, thus provides a closer-to-natural culture environment for experimental assessment of glial structure and functions.

  4. Dynein mutations associated with hereditary motor neuropathies impair mitochondrial morphology and function with age.

    PubMed

    Eschbach, Judith; Sinniger, Jérôme; Bouitbir, Jamal; Fergani, Anissa; Schlagowski, Anna-Isabel; Zoll, Joffrey; Geny, Bernard; René, Frédérique; Larmet, Yves; Marion, Vincent; Baloh, Robert H; Harms, Matthew B; Shy, Michael E; Messadeq, Nadia; Weydt, Patrick; Loeffler, Jean-Philippe; Ludolph, Albert C; Dupuis, Luc

    2013-10-01

    Mutations in the DYNC1H1 gene encoding for dynein heavy chain cause two closely related human motor neuropathies, dominant spinal muscular atrophy with lower extremity predominance (SMA-LED) and axonal Charcot-Marie-Tooth (CMT) disease, and lead to sensory neuropathy and striatal atrophy in mutant mice. Dynein is the molecular motor carrying mitochondria retrogradely on microtubules, yet the consequences of dynein mutations on mitochondrial physiology have not been explored. Here, we show that mouse fibroblasts bearing heterozygous or homozygous point mutation in Dync1h1, similar to human mutations, show profoundly abnormal mitochondrial morphology associated with the loss of mitofusin 1. Furthermore, heterozygous Dync1h1 mutant mice display progressive mitochondrial dysfunction in muscle and mitochondria progressively increase in size and invade sarcomeres. As a likely consequence of systemic mitochondrial dysfunction, Dync1h1 mutant mice develop hyperinsulinemia and hyperglycemia and progress to glucose intolerance with age. Similar defects in mitochondrial morphology and mitofusin levels are observed in fibroblasts from patients with SMA-LED. Last, we show that Dync1h1 mutant fibroblasts show impaired perinuclear clustering of mitochondria in response to mitochondrial uncoupling. Our results show that dynein function is required for the maintenance of mitochondrial morphology and function with aging and suggest that mitochondrial dysfunction contributes to dynein-dependent neurological diseases, such as SMA-LED.

  5. Analysis of nulling phase functions suitable to image plane coronagraphy

    NASA Astrophysics Data System (ADS)

    Hénault, François; Carlotti, Alexis; Vérinaud, Christophe

    2016-07-01

    Coronagraphy is a very efficient technique for identifying and characterizing extra-solar planets orbiting in the habitable zone of their parent star, especially in a space environment. An important family of coronagraphs is actually based on phase plates located at an intermediate image plane of the optical system, and spreading the starlight outside the "Lyot" exit pupil plane of the instrument. In this commutation we present a set of candidate phase functions generating a central null at the Lyot plane, and study how it propagates to the image plane of the coronagraph. These functions include linear azimuthal phase ramps (the well-known optical vortex), azimuthally cosine-modulated phase profiles, and circular phase gratings. Nnumerical simulations of the expected null depth, inner working angle, sensitivity to pointing errors, effect of central obscuration located at the pupil or image planes, and effective throughput including image mask and Lyot stop transmissions are presented and discussed. The preliminary conclusion is that azimuthal cosine functions appear as an interesting alternative to the classical optical vortex of integer topological charge.

  6. Characterization of diamond thin films: Diamond phase identification, surface morphology, and defect structures

    SciTech Connect

    Williams, B.E.; Glass, J.T.

    1989-03-01

    Thin carbon films grown from a low pressure methane-hydrogen gas mixture by microwave plasma enhanced CVD have been examined by Auger electron spectroscopy, secondary ion mass spectrometry, electron and x-ray diffraction, electron energy loss spectroscopy, and electron microscopy. They were determined to be similar to natural diamond in terms of composition, structure, and bonding. The surface morphology of the diamond films was a function of position on the sample surface and the methane concentration in the feedgas. Well-faceted diamond crystals were observed near the center of the sample whereas a less faceted, cauliflower texture was observed near the edge of the sample, presumably due to variations in temperature across the surface of the sample. Regarding methane concentration effects, threefold /111/ faceted diamond crystals were predominant on a film grown at 0.3% CH/sub 4/ in H/sub 2/ while fourfold /100/ facets were observed on films grown in 1.0% and 2.0% CH/sub 4/ in H/sub 2/. Transmission electron microscopy of the diamond films has shown that the majority of diamond crystals have a very high defect density comprised of /111/ twins, /111/ stacking faults, and dislocations. In addition, cross-sectional TEM has revealed a 50 A epitaxial layer of ..beta..--SiC at the diamond-silicon interface of a film grown with 0.3% CH/sub 4/ in H/sub 2/ while no such layer was observed on a diamond film grown in 2.0% CH/sub 4/ in H/sub 2/.

  7. Reversible Morphological Control of Cholecystokinin Tetrapeptide Amyloid Assemblies as a Function of pH.

    PubMed

    Gobeaux, Frédéric; Porcher, Florence; Dattani, Rajeev

    2017-04-03

    Most amyloid assemblies are seen as irreversible and exhibit polymorphism because their assembly is kinetically controlled and different structures are trapped during the aggregation process. However, in the specific case of peptide hormones, formation of amyloid assemblies for storage purposes has been reported. This suggests a strict control of assembly and the ability to disassemble upon hormone secretion. In the present work, we have sought to test these assertions with a short peptide, the cholecystokinin (or gastrin) tetrapeptide (CCK-4), that has been found in both gastrointestinal tract and central nervous system, and whose sequence is shared by a large number of hormones. We have thus studied in vitro this peptide's self-assembling properties in dense phases at different pH levels, thus mimicking in vivo storage conditions. The solubility and morphology of the supramolecular assemblies have been shown to vary with the pH. At low pH, the tetrapeptide exhibits a low solubility and forms microcrystals. At higher pH levels, peptide solubility increases and above a high enough concentration, peptide monomers self-assemble into typical amyloid fibrils of 10-20 nm diameter. The physical network formed by these fibrils results in a birefringent hydrogel phase. Despite the different morphological features exhibited at different pH, structural analysis shows strong similarities. Both supramolecular assemblies-microcrystals and fibrils-are structured by β-sheets. We also show that all these morphologies are reversible and can be either dissolved or changed into one another by switching the pH. In addition, we demonstrate that a modification in the charge sequence of the peptide by amino acid mutation modifies its self-assembly properties. In conclusion, just as the CCK-4 sequence is the minimal sequence required for a complete biological activity at CCKB receptors in the brain, it is also sufficient to form amyloid fibers whose properties can be related to hormone

  8. An Increasing Hybrid Morphological-Linear Perceptron with Evolutionary Learning and Phase Correction for Financial Time Series Forecasting

    NASA Astrophysics Data System (ADS)

    de A. Araújo, Ricardo; Sussner, Peter

    In this paper we present a suitable model to solve the financial time series forecasting problem, called increasing hybrid morphological-linear perceptron (IHMP). An evolutionary training algorithm is presented to design the IHMP (learning process), using a modified genetic algorithm (MGA). The learning process includes an automatic phase correction step that is geared at eliminating the time phase distortions that typically occur in financial time series forecasting. Furthermore, we compare the proposed IHMP with other neural and statistical models using two complex nonlinear problems of financial forecasting.

  9. Morphological and Phase Controlled Tungsten Based Nanoparticles: Synthesis and Characterization of Scheelites, Wolframites, and Oxides Nanomaterials.

    PubMed

    Hernandez-Sanchez, Bernadette A; Boyle, Timothy J; Pratt, Harry D; Rodriguez, Mark A; Brewer, Luke N; Dunphy, Darren R

    2008-11-11

    For the first time tungsten based nanoparticles (WNPs) of scheelite (MWO(4); M = Ca, Sr, Ba, Pb), wolframite (MWO(4); M = Mn, Fe, Zn & (Mg(0.60)Mn(0.17)Fe(0.26))WO(4)), and the oxide (WO(3) and W(18)O(49)) were synthesized from solution precipitation (i.e.,trioctylamine or oleic acid) and solvothermal (i.e., benzyl alcohol) routes. The resultant WNPs were prepared directly from tungsten (VI) ethoxide (W(OCH(2)CH(3))(6), 1) and stoichiometeric mixtures of the following precursors: [Ca(N(SiMe(3))(2))(2)](2) (2), Pb(N(SiMe(3))(2))(2) (3), Mn[(mu-Mes)(2)Mn(Mes)](2) (4), [Fe(mu-Mes)(Mes)](2) (5), Fe(CO)(5) (6), H(+)[Ba(2)(mu(3)-ONep)(mu-ONep)(2)(ONep)(ONep)(3)(py)](-) (2) (7), H(+)[Sr(5)(mu(4)-O)(mu(3)-ONep)(4)(mu-ONep)(4)(ONep)(py)(4)](-) (8), and [Zn(Et)(ONep)(py)](2) (9) where Mes = C(6)H(2)(CH(3))(3)-2,4,6, ONep = OCH(2)CMe(3), Et = CH(2)CH(3), and py = pyridine. Through these routes, the WNP morphologies were found to be manipulated by the processing conditions, while precursor selection influenced the final phase observed. For the solution precipitation route, 1 yielded (5 x 100 nm) W(18)O(49) rods while stochiometeric reactions between 1 and (2 - 9) generated homogenous sub 30 nm nano-dots, -diamonds, -rods, and -wires for the MWO(4) systems. For the solvothermal route, 1 was found to produce wires of WO(3) with aspect ratios of 20 while (1 & 2) formed 10 - 60 nm CaWO(4) nanodots. Room temperature photoluminescent (PL) emission properties of select WNPs were also examined with fluorescence spectroscopy (lambda(ex) = 320 nm). Broad PL emissions = 430, 420, 395, 420 nm were noted for 5 x 100 nm W(18)O(49) rods, 5 x 15 nm, CaWO(4) rods, 10 - 30 nm CaWO(4) dots, and 10 nm BaWO(4) diamonds, respectively.

  10. Morphological and Phase Controlled Tungsten Based Nanoparticles: Synthesis and Characterization of Scheelites, Wolframites, and Oxides Nanomaterials

    PubMed Central

    Hernandez-Sanchez, Bernadette A.; Boyle, Timothy J.; Pratt, Harry D.; Rodriguez, Mark A.; Brewer, Luke N.; Dunphy, Darren R.

    2009-01-01

    For the first time tungsten based nanoparticles (WNPs) of scheelite (MWO4; M = Ca, Sr, Ba, Pb), wolframite (MWO4; M = Mn, Fe, Zn & (Mg0.60Mn0.17Fe0.26)WO4), and the oxide (WO3 and W18O49) were synthesized from solution precipitation (i.e.,trioctylamine or oleic acid) and solvothermal (i.e., benzyl alcohol) routes. The resultant WNPs were prepared directly from tungsten (VI) ethoxide (W(OCH2CH3)6, 1) and stoichiometeric mixtures of the following precursors: [Ca(N(SiMe3)2)2]2 (2), Pb(N(SiMe3)2)2 (3), Mn[(μ-Mes)2Mn(Mes)]2 (4), [Fe(μ-Mes)(Mes)]2 (5), Fe(CO)5 (6), H+[Ba2(μ3-ONep)(μ-ONep)2(ONep)(ONep)3(py)]−2 (7), H+[Sr5(μ4-O)(μ3-ONep)4(μ-ONep)4(ONep)(py)4]− (8), and [Zn(Et)(ONep)(py)]2 (9) where Mes = C6H2(CH3)3-2,4,6, ONep = OCH2CMe3, Et = CH2CH3, and py = pyridine. Through these routes, the WNP morphologies were found to be manipulated by the processing conditions, while precursor selection influenced the final phase observed. For the solution precipitation route, 1 yielded (5 × 100 nm) W18O49 rods while stochiometeric reactions between 1 and (2 – 9) generated homogenous sub 30 nm nano-dots, -diamonds, -rods, and -wires for the MWO4 systems. For the solvothermal route, 1 was found to produce wires of WO3 with aspect ratios of 20 while (1 & 2) formed 10 – 60 nm CaWO4 nanodots. Room temperature photoluminescent (PL) emission properties of select WNPs were also examined with fluorescence spectroscopy (λex = 320 nm). Broad PL emissions = 430, 420, 395, 420 nm were noted for 5 × 100 nm W18O49 rods, 5 × 15 nm, CaWO4 rods, 10 – 30 nm CaWO4 dots, and 10 nm BaWO4 diamonds, respectively. PMID:19911034

  11. Morphology and phase transformations of tin oxide nanostructures synthesized by the hydrothermal method in the presence of dicarboxylic acids

    NASA Astrophysics Data System (ADS)

    Zima, Tatyana.; Bataev, Ivan

    2016-11-01

    A new approach to the synthesis of non-stoichiometric tin oxide structures with different morphologies and the phase compositions has been evaluated. The nanostructures were synthesized by hydrothermal treatment of the mixtures of dicarboxylic acids ― aminoterephthalic or oxalic ― with nanocrystalline SnO2 powder, which was obtained via the sol-gel technology. The products were characterized by Raman and IR spectroscopy, SEM, HRTEM, and XRD analysis. It was shown that the controlled addition of a dicarboxylic acid leads not only to a change in the morphology of the nanostructures, but also to SnO2-SnO2/Sn3O4-Sn3O4-SnO phase transformations. A single-phase Sn3O4 in the form of the well-separated hexagonal nanoplates and mixed SnO2/Sn3O4 phases in the form of hierarchical flower-like structures were obtained in the presence of organic additives. The effects of concentration, redox activity of the acids and heat treatment on the basic characteristics of the synthesized tin oxide nanostructures and phase transformations in the synthesized materials are discussed.

  12. Patterson function and δ recycling: derivation of the phasing equations.

    PubMed

    Rius, Jordi

    2012-05-01

    Two phasing equations based on the Fourier syntheses δ(P) = T(-1)[(E(2) - )exp(iφ)] and δ(M) = T(-1)[(E - )exp(iφ)] were recently described [Rius (2012). Acta Cryst. A 68, 77-81] (E is the quasi-normalized structure factor and is the average over all reflections). These equations were found by comparison with the direct methods origin-free modulus sum function and constitute the core of the `δ recycling' phasing procedure. The derivation of these phasing equations from the minimization of a residual (R(P)) between two differently calculated density functions (one of them including the positivity constraint) is shown.

  13. [Relationship between vitrectomy and the morphology and function of the retina].

    PubMed

    Terasaki, Hiroko

    2003-12-01

    Pathological processes in the vitreous will be reflected in the morphology and function of the retina, and these processes can originate from sources outside the vitreous. The purpose of vitreous surgery is to remove the qualitatively and/or morphologically diseased vitreous. Successful vitrectomy will be manifested by an improvement in the structure and/or function of the retina. We have evaluated the morphology of the vitreoretinal interface, and the function of the retina before and after vitreous surgery. Plasmin-assisted vitrectomy was used in some cases to remove the diseased vitreous more efficiently and less invasively. The effect of this procedure was assessed by examining the morphology and function of the retina. First, the relationship between the qualitative and structural abnormality of the vitreous in macular diseases was studied. In aphakic/pseudophakic eyes with cystoid macular edema, there was a depression of retinal function over the entire retina which may have been caused by chemical mediators released into the vitreous. These mediators may have been produced by inflammation in the anterior segment of the eye. In eyes with an idiopathic macular hole, optical coherence tomographic (OCT) images suggested that the progression of the macular hole might depend on a balance between foveal adhesion and the posterior vitreous. Second, the efficacy, surgical damage, and limitations of vitreous surgery were investigated. The recovery of macular function was assessed by focal macular electroretinograms (FMERGs) after vitrectomy for epiretinal membrane, choroidal neovascularization, and diabetic macular edema. The concurrent examination by optical coherence tomography (OCT) suggested that a decrease in retinal thickness contributed to the functional recovery. Macular functional recovery was delayed and limited after macular translocation, diabetic macular edema, and internal limiting membrane peeling. Third, we studied the effect of plasmin

  14. Density Functional Theory for Phase-Ordering Transitions

    SciTech Connect

    Wu, Jianzhong

    2016-03-30

    Colloids display astonishing structural and dynamic properties that can be dramatically altered by modest changes in the solution condition or an external field. This complex behavior stems from a subtle balance of colloidal forces and intriguing mesoscopic and macroscopic phase transitions that are sensitive to the processing conditions and the dispersing environment. Whereas the knowledge on the microscopic structure and phase behavior of colloidal systems at equilibrium is now well-advanced, quantitative predictions of the dynamic properties and the kinetics of phase-ordering transitions in colloids are not always realized. Many important mesoscopic and off-equilibrium colloidal states remain poorly understood. The proposed research aims to develop a new, unifying approach to describe colloidal dynamics and the kinetics of phase-ordering transitions based on accomplishments from previous work for the equilibrium properties of both uniform and inhomogeneous systems and on novel concepts from the state-of-the-art dynamic density functional theory. In addition to theoretical developments, computational research is designed to address a number of fundamental questions on phase-ordering transitions in colloids, in particular those pertinent to a competition of the dynamic pathways leading to various mesoscopic structures, off-equilibrium states, and crystalline phases. By providing a generic theoretical framework to describe equilibrium, metastable as well as non-ergodic phase transitions concurrent with the colloidal self-assembly processes, accomplishments from this work will have major impacts on both fundamental research and technological applications.

  15. Diversity of morphology and function in arbuscular mycorrhizal symbioses in Brachypodium distachyon.

    PubMed

    Hong, Jeon J; Park, Yong-Soon; Bravo, Armando; Bhattarai, Kishor K; Daniels, Dierdra A; Harrison, Maria J

    2012-09-01

    Brachypodium distachyon is a grass species that serves as a useful model for wheat and also for many of the grass species proposed as feedstocks for bioenergy production. Here, we monitored B. distachyon symbioses with five different arbuscular mycorrhizal (AM) fungi and identified symbioses that vary functionally with respect to plant performance. Three symbioses promoted significant increases in shoot phosphorus (P) content and shoot growth of Brachypodium, while two associations were neutral. The Brachypodium/Glomus candidum symbiosis showed a classic 'Paris-type' morphology. In the other four AM symbioses, hyphal growth was exclusively intracellular and linear; hyphal coils were not observed and arbuscules were abundant. Expression of the Brachypodium ortholog of the symbiosis-specific phosphate (Pi) transporter MtPT4 did not differ significantly in these five interactions indicating that the lack of apparent functionality did not result from a failure to express this gene or several other AM symbiosis-associated genes. Analysis of the expression patterns of the complete PHT1 Pi transporter gene family and AMT2 gene family in B. distachyon/G. intraradices mycorrhizal roots identified additional family members induced during symbiosis and again, transcript levels were similar in the different Brachypodium AM symbioses. This initial morphological, molecular and functional characterization provides a framework for future studies of functional diversity in AM symbiosis in B. distachyon.

  16. Retinal function and morphology are altered in cattle infected with the prion disease transmissible mink encephalopathy.

    PubMed

    Smith, J D; Greenlee, J J; Hamir, A N; Richt, J A; Greenlee, M H West

    2009-09-01

    Transmissible spongiform encephalopathies (TSEs) are a group of diseases that result in progressive and invariably fatal neurologic disease in both animals and humans. TSEs are characterized by the accumulation of an abnormal protease-resistant form of the prion protein in the central nervous system. Transmission of infectious TSEs is believed to occur via ingestion of prion protein-contaminated material. This material is also involved in the transmission of bovine spongiform encephalopathy ("mad cow disease") to humans, which resulted in the variant form of Creutzfeldt-Jakob disease. Abnormal prion protein has been reported in the retina of TSE-affected cattle, but despite these observations, the specific effect of abnormal prion protein on retinal morphology and function has not been assessed. The objective of this study was to identify and characterize potential functional and morphologic abnormalities in the retinas of cattle infected with a bovine-adapted isolate of transmissible mink encephalopathy. We used electroretinography and immunohistochemistry to examine retinas from 10 noninoculated and 5 transmissible mink encephalopathy-inoculated adult Holstein steers. Here we show altered retinal function, as evidenced by prolonged implicit time of the electroretinogram b-wave, in transmissible mink encephalopathy-infected cattle before the onset of clinical illness. We also demonstrate disruption of rod bipolar cell synaptic terminals, indicated by decreased immunoreactivity for the alpha isoform of protein kinase C and vesicular glutamate transporter 1, and activation of Müller glia, as evidenced by increased glial fibrillary acidic protein and glutamine synthetase expression, in the retinas of these cattle at the time of euthanasia due to clinical deterioration. This is the first study to identify both functional and morphologic alterations in the retinas of TSE-infected cattle. Our results support future efforts to focus on the retina for the development of

  17. Hydrothermal synthesis of copper selenides with controllable phases and morphologies from an ionic liquid precursor

    NASA Astrophysics Data System (ADS)

    Liu, Xiaodi; Duan, Xiaochuan; Peng, Peng; Zheng, Wenjun

    2011-12-01

    Cu2-xSe nanocrystals and CuSe nanoflakes are successfully synthesized through a convenient hydrothermal method from an ionic liquid precursor 1-n-butyl-3-ethylimidazolium methylselenite ([BMIm][SeO2(OCH3)]). The phases and morphologies of the copper selenides can be controlled by simply changing the atom ratio of Cu/Se in the reactants and reaction temperature. Furthermore, it is found that the [BMIm][SeO2(OCH3)] not only serves as Se source but also has influence on the shapes of CuSe nanoflakes. The adsorption of alkyl imidazolium rings ([BMIm]+) onto the (0001) facets of covellite CuSe prohibits the growth in the [0001] direction, and CuSe nuclei growth mainly processes along the six symmetric directions (+/-[01&cmb.macr;11], +/-[101&cmb.macr;1&cmb.macr;], and +/-[1&cmb.macr;100]) to form flakelike CuSe. The obtained copper selenides are characterized by XRD, SEM, EDS, XPS, TEM, and HRTEM. The results indicate that the Cu2-xSe nanocrystals are nearly spherical particles with an average diameter of about 20 nm, the hexagonal CuSe nanoflakes are single crystals with an edge length of 100-400 nm and a thickness of 25-50 nm. The potential formation mechanism of the copper selenides is also proposed.Cu2-xSe nanocrystals and CuSe nanoflakes are successfully synthesized through a convenient hydrothermal method from an ionic liquid precursor 1-n-butyl-3-ethylimidazolium methylselenite ([BMIm][SeO2(OCH3)]). The phases and morphologies of the copper selenides can be controlled by simply changing the atom ratio of Cu/Se in the reactants and reaction temperature. Furthermore, it is found that the [BMIm][SeO2(OCH3)] not only serves as Se source but also has influence on the shapes of CuSe nanoflakes. The adsorption of alkyl imidazolium rings ([BMIm]+) onto the (0001) facets of covellite CuSe prohibits the growth in the [0001] direction, and CuSe nuclei growth mainly processes along the six symmetric directions (+/-[01&cmb.macr;11], +/-[101&cmb.macr;1&cmb.macr;], and +/-[1

  18. Impaired Cognitive Function and Altered Hippocampal Synapse Morphology in Mice Lacking Lrrtm1, a Gene Associated with Schizophrenia

    PubMed Central

    Sakoori, Kazuto; Akagi, Takumi; Hashikawa, Tsutomu; Morimura, Naoko; Yamada, Kazuyuki; Aruga, Jun

    2011-01-01

    Recent genetic linkage analysis has shown that LRRTM1 (Leucine rich repeat transmembrane neuronal 1) is associated with schizophrenia. Here, we characterized Lrrtm1 knockout mice behaviorally and morphologically. Systematic behavioral analysis revealed reduced locomotor activity in the early dark phase, altered behavioral responses to novel environments (open-field box, light-dark box, elevated plus maze, and hole board), avoidance of approach to large inanimate objects, social discrimination deficit, and spatial memory deficit. Upon administration of the NMDA receptor antagonist MK-801, Lrrtm1 knockout mice showed both locomotive activities in the open-field box and responses to the inanimate object that were distinct from those of wild-type mice, suggesting that altered glutamatergic transmission underlay the behavioral abnormalities. Furthermore, administration of a selective serotonin reuptake inhibitor (fluoxetine) rescued the abnormality in the elevated plus maze. Morphologically, the brains of Lrrtm1 knockout mice showed reduction in total hippocampus size and reduced synaptic density. The hippocampal synapses were characterized by elongated spines and diffusely distributed synaptic vesicles, indicating the role of Lrrtm1 in maintaining synaptic integrity. Although the pharmacobehavioral phenotype was not entirely characteristic of those of schizophrenia model animals, the impaired cognitive function may warrant the further study of LRRTM1 in relevance to schizophrenia. PMID:21818371

  19. Free energy functionals for efficient phase field crystal modeling of structural phase transformations.

    PubMed

    Greenwood, Michael; Provatas, Nikolas; Rottler, Jörg

    2010-07-23

    The phase field crystal (PFC) method is a promising technique for modeling materials with atomic resolution on mesoscopic time scales. While numerically more efficient than classical density functional theory (CDFT), its single mode free energy limits the complexity of structural transformations that can be simulated. We introduce a new PFC model inspired by CDFT, which uses a systematic construction of two-particle correlation functions that allows for a broad class of structural transformations. Our approach considers planar spacings, lattice symmetries, planar atomic densities, and atomic vibrational amplitudes in the unit cell, and parameterizes temperature and anisotropic surface energies. The power of our approach is demonstrated by two examples of structural phase transformations.

  20. Functional morphology of parasitic isopods: understanding morphological adaptations of attachment and feeding structures in Nerocila as a pre-requisite for reconstructing the evolution of Cymothoidae

    PubMed Central

    Haug, Joachim T.

    2016-01-01

    Parasites significantly influence food webs and ecosystems and occur all over the world in almost every animal group. Within crustaceans there are numerous examples of ectoparasites; for example, representatives of the isopod group Cymothoidae. These obligatory parasitic isopods are relatively poorly studied regarding their functional morphology. Here we present new details of the morphological adaptations to parasitism of the cymothoiid ingroup Nerocila with up-to-date imaging methods (macro photography, stereo imaging, fluorescence photography, micro CT, and histology). Central aspects of the study were (1) the morphology of the mouthparts and (2) the attachment on the host, hence the morphology of the thoracopods. The mouthparts (labrum, mandibles, paragnaths, maxillulae, maxillae, maxillipeds) form a distinct mouth cone and are most likely used for true sucking. The mouthparts are tightly “folded” around each other and provide functional rails for the only two moving mouthparts, mandible and maxillula. Both are not moving in an ancestral-type median-lateral movement, but are strongly tilted to move more in a proximal-distal axis. New details concerning the attachment demonstrate that the angular arrangement of the thoracopods is differentiated to impede removal by the host. The increased understanding of morphological adaptation to parasitism of modern forms will be useful in identifying disarticulated (not attached to the host) fossil parasites. PMID:27441121

  1. Functional and morphological effects of resistance exercise on disuse-induced skeletal muscle atrophy.

    PubMed

    Nicastro, H; Zanchi, N E; Luz, C R da; Lancha, A H

    2011-11-01

    Abstract quality of life. Since there is no currently effective and safe treatment available for skeletal muscle atrophy, the search for new alternatives is necessary. Resistance exercise (RE) seems to be an important tool in the treatment of disuse-induced skeletal muscle atrophy by promoting positive functional (strength and power) and structural (hypertrophy and phenotypic changes) adaptive responses. Human and animal studies using different types of resistance exercise (flywheel, vascular occlusion, dynamic, isometric, and eccentric) have obtained results of great importance. However, since RE is a complex phenomenon, lack of strict control of its variables (volume, frequency, intensity, muscle action, rest intervals) limits the interpretation of the impact of the manipulation on skeletal muscle remodeling and function under disuse. The aim of this review is to critically describe the functional and morphological role of resistance exercise in disuse-induced skeletal muscle atrophy with emphasis on the principles of training.

  2. The functional morphology and role of cardiac telocytes in myocardium regeneration.

    PubMed

    Varga, Ivan; Danisovic, Lubos; Kyselovic, Jan; Gazova, Andrea; Musil, Peter; Miko, Michal; Polak, Stefan

    2016-05-19

    Key morphological discoveries in recent years have included the discovery of new cell populations inside the heart called cardiac telocytes. These newly described cells of the connective tissue have extremely long cytoplasmic processes through which they form functionally connected three-dimensional networks that connect cells of the immune system, nerve fibers, cardiac stem cells, and cardiac muscle cells. Based on their functions, telocytes are also referred to as "connecting cells" or "nurse cells" for cardiac progenitor stem cells. In this critical review, we provide a summary of the latest research on cardiac telocytes localized in all layers of the heart - from the historical background of their discovery, through ultrastructural, immunohistochemical, and functional characterizations, to the application of this knowledge to the fields of cardiology, stem cell research, and regenerative medicine.

  3. Metre-long cell-laden microfibres exhibit tissue morphologies and functions

    NASA Astrophysics Data System (ADS)

    Onoe, Hiroaki; Okitsu, Teru; Itou, Akane; Kato-Negishi, Midori; Gojo, Riho; Kiriya, Daisuke; Sato, Koji; Miura, Shigenori; Iwanaga, Shintaroh; Kuribayashi-Shigetomi, Kaori; Matsunaga, Yukiko T.; Shimoyama, Yuto; Takeuchi, Shoji

    2013-06-01

    Artificial reconstruction of fibre-shaped cellular constructs could greatly contribute to tissue assembly in vitro. Here we show that, by using a microfluidic device with double-coaxial laminar flow, metre-long core-shell hydrogel microfibres encapsulating ECM proteins and differentiated cells or somatic stem cells can be fabricated, and that the microfibres reconstitute intrinsic morphologies and functions of living tissues. We also show that these functional fibres can be assembled, by weaving and reeling, into macroscopic cellular structures with various spatial patterns. Moreover, fibres encapsulating primary pancreatic islet cells and transplanted through a microcatheter into the subrenal capsular space of diabetic mice normalized blood glucose concentrations for about two weeks. These microfibres may find use as templates for the reconstruction of fibre-shaped functional tissues that mimic muscle fibres, blood vessels or nerve networks in vivo.

  4. Insights into phase transitions and entanglement from density functional theory

    NASA Astrophysics Data System (ADS)

    Wei, Bo-Bo

    2016-11-01

    Density functional theory (DFT) has met great success in solid state physics, quantum chemistry and in computational material sciences. In this work we show that DFT could shed light on phase transitions and entanglement at finite temperatures. Specifically, we show that the equilibrium state of an interacting quantum many-body system which is in thermal equilibrium with a heat bath at a fixed temperature is a universal functional of the first derivatives of the free energy with respect to temperature and other control parameters respectively. This insight from DFT enables us to express the average value of any physical observable and any entanglement measure as a universal functional of the first derivatives of the free energy with respect to temperature and other control parameters. Since phase transitions are marked by the nonanalytic behavior of free energy with respect to control parameters, the physical quantities and entanglement measures may present nonanalytic behavior at critical point inherited from their dependence on the first derivative of free energy. We use two solvable models to demonstrate these ideas. These results give new insights for phase transitions and provide new profound connections between entanglement and phase transitions in interacting quantum many-body physics.

  5. Cardiac Morphology and Function, and Blood Gas Transport in Aquaporin-1 Knockout Mice

    PubMed Central

    Al-Samir, Samer; Wang, Yong; Meissner, Joachim D.; Gros, Gerolf; Endeward, Volker

    2016-01-01

    We have studied cardiac and respiratory functions of aquaporin-1-deficient mice by the Pressure-Volume-loop technique and by blood gas analysis. In addition, the morphological properties of the animals' hearts were analyzed. In anesthesia under maximal dobutamine stimulation, the mice exhibit a moderately elevated heart rate of < 600 min−1 and an O2 consumption of ~0.6 ml/min/g, which is about twice the basal rate. In this state, which is similar to the resting state of the conscious animal, all cardiac functions including stroke volume and cardiac output exhibited resting values and were identical between deficient and wildtype animals. Likewise, pulmonary and peripheral exchange of O2 and CO2 were normal. In contrast, several morphological parameters of the heart tissue of deficient mice were altered: (1) left ventricular wall thickness was reduced by 12%, (2) left ventricular mass, normalized to tibia length, was reduced by 10–20%, (3) cardiac muscle fiber cross sectional area was decreased by 17%, and (4) capillary density was diminished by 10%. As the P-V-loop technique yielded normal end-diastolic and end-systolic left ventricular volumes, the deficient hearts are characterized by thin ventricular walls in combination with normal intraventricular volumes. The aquaporin-1-deficient heart thus seems to be at a disadvantage compared to the wild-type heart by a reduced left-ventricular wall thickness and an increased diffusion distance between blood capillaries and muscle mitochondria. While under the present quasi-resting conditions these morphological alterations have no consequences for cardiac function, we expect that the deficient hearts will show a reduced maximal cardiac output. PMID:27252655

  6. [Echocardiographic evaluation of the athlete's heart: from morphological adaptations to myocardial function].

    PubMed

    D'Andrea, Antonello; Galderisi, Maurizio; Sciomer, Susanna; Nistri, Stefano; Agricola, Eustachio; Ballo, Piercarlo; Buralli, Simona; D'Errico, Arcangelo; Losi, Maria Angela; Mele, Donato; Mondillo, Sergio

    2009-08-01

    The definition of the athlete's heart includes the mechanisms of cardiac adaptation to training, characterized by the increase of internal chamber dimensions, ventricular wall thickness, and atrial chambers. The morphology of the athlete's heart is intermediate between concentric and eccentric left ventricular hypertrophy (LVH), in relation to the large prevalence of mixed sports activities and training protocols (including both aerobic and anaerobic exercise). Echocardiography is the tool of choice for the assessment of the athlete's heart and also for the differentiation of physiologic and pathologic LVH (hypertrophic cardiomyopathy and LVH due to arterial hypertension). The initial echocardiographic approach includes the quantitative analysis of the left ventricle, in order to calculate left ventricular mass, left ventricular mass index and relative wall thickness for diagnosing concentric or eccentric LVH. Tissue Doppler (pulsed or color modality) and strain rate imaging (Doppler or two-dimensional modality) may give additional information to the standard indices of systolic function. Diastolic function can be evaluated not only by standard Doppler transmitral inflow measurements but also using pulsed tissue Doppler, which may allow to distinguish the athlete's LVH from diastolic impairment of hypertensive patients or hypertrophic cardiomyopathy by the simple determination of myocardial early diastolic velocity. Also the morphological and functional features of the left atrium and of the right ventricle can be assessed in the athlete's heart by combining standard echocardiography with new echocardiographic technologies.

  7. Morphological and Functional Parameters in Patients with Tooth Wear before and after Treatment

    PubMed Central

    Sierpinska, Teresa; Kuc, Joanna; Golebiewska, Maria

    2013-01-01

    Advanced tooth wear often results in lost vertical dimension and impacts facial aesthetics. Complex restorative treatment can replace the lost tooth structure and improve functional occlusal and facial skeleton parameters. Purpose: The aim of the study is to assess changes in the morphological and functional occlusal parameters of the facial skeleton after prosthetic rehabilitation that increased lost occlusal vertical dimension. Material and Methodology: 50 patients with advanced tooth wear were clinically examined, to assess the degree of wear. Each subject underwent cephalometric analysis, digital occlusal analysis, and electromyographic analysis, of the anterior temporalis, superficial masetter, anterior digastric, and the sternocleidomastoid muscles. Prosthodontic treatment was performed to restore the occlusal vertical dimension of each subject’s occlusion, which was followed by repeating the pretreatment analyses. Pre and post treatment parameters were statistically compared. Results: Pre-treatment cephalometric analysis showed that lost vertical dimension reduced anterior facial height and resulted in small angular skeletal parameters. Post treatment anterior facial height increased from the increased occlusal vertical dimension. The mean value of functional electrical activity during clenching post treatment, increased compared to pretreatment. Conclusion: Increasing the vertical dimension of occlusion improved facial aesthetics by positively affecting facial skeletal angles. The restored occlusal surface morphology changed the pre treatment flat broad occlusal contacts into more point contacts. The increased vertical dimension of occlusion after treatment also increased muscle activity levels over the pretreatment levels after three months period of adaptation. PMID:23802024

  8. Functional morphology of the palato-maxillary apparatus in "Palatine dragging" snakes (Serpentes: Elapidae: Acanthophis, Oxyuranus).

    PubMed

    Deufel, Alexandra; Cundall, David

    2010-01-01

    Elapid snakes have previously been divided into two groups (palatine erectors and palatine draggers) based on the morphology and inferred movements of their palatine bone during prey transport (swallowing). We investigated the morphology and the functioning of the feeding apparatus of several palatine draggers (Acanthophis antarcticus, Oxyuranus scutellatus, Pseudechis australis) and compared them to published records of palatine erectors. We found that the palatine in draggers does not move as a straight extension of the pterygoid as originally proposed. The dragger palato-pterygoid joint flexes laterally with maxillary rotation when the mouth opens and the jaw apparatus is protracted and slightly ventrally during mouth closing. In contrast, in palatine erectors, the palato-pterygoid joint flexes ventrally during upper jaw protraction. In draggers, the anterior end of the palatine also projects rostrally during protraction, unlike the stability of the anterior end seen in erectors. Palatine draggers differ from palatine erectors in four structural features of the palatine and its relationships to surrounding elements. The function of the palato-pterygoid bar in both draggers and erectors can be explained by a typical colubroid muscle contraction pattern, which acts on a set of core characters shared among all derived snakes. Although palatine dragging elapids share a fundamental design of the palato-maxillary apparatus with all higher snakes, they provide yet another demonstration of minor structural modifications producing functional variants.

  9. Morphological and functional changes in the vertebral column with increasing aquatic adaptation in crocodylomorphs

    PubMed Central

    Molnar, Julia L.; Pierce, Stephanie E.; Bhullar, Bhart-Anjan S.; Turner, Alan H.; Hutchinson, John R.

    2015-01-01

    The lineage leading to modern Crocodylia has undergone dramatic evolutionary changes in morphology, ecology and locomotion over the past 200+ Myr. These functional innovations may be explained in part by morphological changes in the axial skeleton, which is an integral part of the vertebrate locomotor system. Our objective was to estimate changes in osteological range of motion (RoM) and intervertebral joint stiffness of thoracic and lumbar vertebrae with increasing aquatic adaptation in crocodylomorphs. Using three-dimensional virtual models and morphometrics, we compared the modern crocodile Crocodylus to five extinct crocodylomorphs: Terrestrisuchus, Protosuchus, Pelagosaurus, Steneosaurus and Metriorhynchus, which span the spectrum from terrestrial to fully aquatic. In Crocodylus, we also experimentally measured changes in trunk flexibility with sequential removal of osteoderms and soft tissues. Our results for the more aquatic species matched our predictions fairly well, but those for the more terrestrial early crocodylomorphs did not. A likely explanation for this lack of correspondence is the influence of other axial structures, particularly the rigid series of dorsal osteoderms in early crocodylomorphs. The most important structures for determining RoM and stiffness of the trunk in Crocodylus were different in dorsoventral versus mediolateral bending, suggesting that changes in osteoderm and rib morphology over crocodylomorph evolution would have affected movements in some directions more than others. PMID:26716001

  10. [Function and morphology of isolated rat kidney following cellfree perfusion with various plasmaexpanders (author's transl)].

    PubMed

    Franke, H; Sobotta, E E; Witzki, G; Unsicker, K

    1975-05-01

    Isolated arteficially perfused rat kidneys prepared as described by Franke et al. (1971) were perfused for 60 min with solutions of Haemaccel, Dextran 40, Pluronic-F-108, or hydroxy-aethyl starch in a single pass system. The glomerular filtration rate (GFR) of the Haemaccel or Dextran 40 perfused organs amounted during the first 30 min to 0.58 ml X g-1 X min-1 and 0.47 ml X g-1 X min-1 respectively. Using Pluronic-F-108 or hydroxy-aethyl starch GFR rose to 0.94 ml X g-1 X min-1 and to 0.85 ml X G-1 X min-1. With Haemaccel or Dextran 40 solutions a mean tubular Na-reabsorption of 75.4 mumol X g-1 X min-1 and of 59 mumol X g-1 X min-1 respectively was determined. Employing Pluronic-F-108 or hydroxy-aethyl starch a mean sodium net transport of 92.6 mumol X g-1 X min-1 in both experimental groups was obtained. The differences described in the functional capabilities of Haemaccel or Dextran 40 and of Pluronic-F-108 or Hydroxyethyl starch perfused kidneys are in good accordance with morphological changes in the ultrastructure. The most striking morphological deviations were found in proximal tubules of those kidneys perfused with Haemaccel solutions. On the other hand after perfusion with hydroxyethyl starch only very few morphological alterations could be detected.

  11. Influence of the amount of dietary gluten on gastrointestinal morphology and function in dermatitis herpetiformis.

    PubMed

    Andersson, H; Björkman, A C; Gillberg, R; Kastrup, W; Mobacken, H; Stockbrügger, R

    1984-07-01

    The individual daily intake of gluten was calculated in 45 patients with dermatitis herpetiformis (DH) on the basis of a depth interview about food habits. Gastric and small intestinal morphology and function were studied concurrently. Mean daily gluten intake was estimated to be 15 g, a figure which corresponds well to the average gluten intake in Sweden. There was a significant correlation between the degree of morphological mucosal changes of the small intestine and the quantity of gluten ingested. All patients with jejunal villous atrophy consumed more than 10 g gluten daily and all but one patient with normal jejunal villous structure had a gluten intake of less than 10 g/d. The findings suggest a dose-dependent effect of gluten on the intestinal mucosa. Conversely, the daily gluten intake was not correlated to gastric morphology, gastric acid secretion, serum gastrin levels or serum parietal cell antibodies. Patients with reduced ability to secrete gastric acid did not differ from the remaining patients in this respect. Whereas the coeliac-like enteropathy in DH seems to be caused by ingested gluten, the frequently occurring achlorhydric atrophic gastritis must be assumed to be of different immunopathogenesis.

  12. The integration of locomotion and prey capture in divergent cottid fishes: functional disparity despite morphological similarity.

    PubMed

    Kane, Emily A; Higham, Timothy E

    2011-04-01

    Many mobile animals rely on the integration of locomotion and feeding to capture prey. Fishes commonly swim up to a prey item and utilize a combination of ram and suction feeding for prey capture. Marine cottids represent a diverse and abundant lineage of fishes that exhibit variation in feeding mode that is related to their mouth morphology. However, little is known regarding the integration of the locomotor and feeding systems during prey capture. We quantified the feeding kinematics, feeding performance and integration of locomotion and feeding in two species of divergent cottids: Blepsias cirrhosus (silver-spotted sculpin) and Oligocottus maculosus (tidepool sculpin). Individuals were caught from sympatric habitats near the Bamfield Marine Sciences Centre on Vancouver Island and filmed with a high-speed video camera (500 Hz) while feeding on amphipod prey. Two principal component axes summarize differences in integration and feeding mode despite similarity in attack velocity and feeding morphology (peak gape, peak cranial elevation and peak jaw protrusion). A greater number of correlations between locomotor and feeding variables in B. cirrhosus, compared with O. maculosus, indicate greater integration. We conclude that traditional measures of attack kinematics do not capture functionally and ecologically relevant differences between species. The mechanisms underlying differences in locomotor strategy likely result from unexplored morphological or ecological differences between species. In cottids, integration is apparent in more basal, subtidal species such as B. cirrhosus, and the need for integration may be superceded by demands from the habitat in more derived, shallow-water species such as O. maculosus.

  13. MesoDyn simulation study on the phase morphologies of Miktoarm PEO-b-PMMA copolymer doped by nanoparticles

    NASA Astrophysics Data System (ADS)

    Mu, Dan; Li, Jian-Quan; Feng, Sheng-Yu

    2013-03-01

    The compatibility of six groups of 12 miktoarm poly(ethylene oxide)-block-poly(methyl methacrylate) (PEO-b-PMMA) copolymers is studied at 270, 298 and 400 K via mesoscopic modeling. The values of the order parameters depend on both the architectures of the block copolymers and the simulation temperature, while the tendency to change of the order parameters at low temperature, such as 270 and 298 K, is nearly the same. However, the values of order parameters of the copolymer in the same group are the same at high temperature, i.e. 400 K. Obviously, temperature has a more obvious effect on long and PEO-rich chains. A study of plain copolymers doped with nanoparticles shows that the microscopic phase is influenced by not only the properties of the nanoparticles, such as the size, number and density, but also the composition and architecture of copolymers. Increasing the size and the number of the nanoparticles used as a dopant plays the most significant role on determining the phase morphologies of the copolymers at lower and higher temperature, respectively. In paricular, the 23141 and 23241-type copolymers, which are both of PEO-rich composition, presents microscopic phase separation as perforated lamallae phase morphologies at 400 K, alternated with PEO and PMMA components.

  14. Effects of nanoscale morphology and defects in oxide: optoelectronic functions of zinc oxide nanowires

    NASA Astrophysics Data System (ADS)

    Nagao, Tadaaki; Duy Dao, Thang; Sugavaneshwar, R. P.; Chen, Kai; Nanda, K. K.

    2016-02-01

    Oxide nanomaterials have been attracting growing interest for both fundamental research and industrial applications ranging from gas sensors, light-emitting devices, to photocatalysts, and solar cells. The optical and electronic properties of oxide nanomaterials are strongly dependent on their surface morphologies as well as defects, such as surface areas, aspect ratios, foreign atom impurities, and oxygen vacancies. In this review, we describe some examples of our recent contributions to the nanomaterials and devices that exhibit remarkable functionalities based on one-dimensional nanostructures of ZnO and their hetero junctions as well as their variants with appropriately incorporated dopants.

  15. Functional morphology of the midgut of a sandfly as compared to other hematophagous nematocera.

    PubMed

    Rudin, W; Hecker, H

    1982-01-01

    The midgut epithelium of female Lutzomyia longipalpis was investigated by means of electron microscopic morphometry before and during blood digestion. Ultrastructure and cytological changes of the stomach cells upon blood feeding were generally similar to the ones described for Phlebotomus longipes (Gemetchu, 1974) and for mosquitoes (Hecker, 1977). In addition, the quantitative composition of the cells resembled the one of mosquitoes in many respects. Despite some morphological differences in the functional gut cytology, it can be admitted that, in general, digestive processes may run similarly in the midguts of sandflies and mosquitoes.

  16. Anchoring Ethinylestradiol Induced Gene Expression Changes with Testicular Morphology and Reproductive Function in the Medaka

    PubMed Central

    Miller, Hilary D.; Clark, Bryan W.; Hinton, David E.; Whitehead, Andrew; Martin, Stan; Kwok, Kevin W.; Kullman, Seth W.

    2012-01-01

    Environmental estrogens are ubiquitous in the environment and can cause detrimental effects on male reproduction. In fish, a multitude of effects from environmental estrogens have been observed including altered courting behavior and fertility, sex reversal, and gonadal histopathology. However, few studies in fish assess the impacts of estrogenic exposure on a physiological endpoint, such as reproduction, as well as the associated morphologic response and underlying global gene expression changes. This study assessed the implications of a 14 day sub-chronic exposure of ethinylestradiol (EE2; 1.0 or 10.0 µg/L EE2) on male medaka fertility, testicular histology and testicular gene expression. The findings demonstrate that a 14 day exposure to EE2 induced impaired male reproductive capacity and time- and dose-dependent alterations in testicular morphology and gene expression. The average fertilization rate/day following the exposure for control, 1.0 and 10.0 µg/L EE2 was 91.3% (±4.4), 62.8% (±8.3) and 28.8% (±5.8), respectively. The testicular morphologic alterations included increased germ cell apoptosis, decreased germinal epithelium and thickening of the interstitium. These changes were highly associated with testicular gene expression changes using a medaka-specific microarray. A pathway analysis of the differentially expressed genes emphasized genes and pathways associated with apoptosis, cell cycle and proliferation, collagen production/extracellular matrix organization, hormone signaling, male reproduction and protein ubiquitination among others. These findings highlight the importance of anchoring global gonadal gene expression changes with morphology and ultimately with tissue/organ function. PMID:23300682

  17. Phase transition of Boolean networks with partially nested canalizing functions

    NASA Astrophysics Data System (ADS)

    Jansen, Kayse; Matache, Mihaela Teodora

    2013-07-01

    We generate the critical condition for the phase transition of a Boolean network governed by partially nested canalizing functions for which a fraction of the inputs are canalizing, while the remaining non-canalizing inputs obey a complementary threshold Boolean function. Past studies have considered the stability of fully or partially nested canalizing functions paired with random choices of the complementary function. In some of those studies conflicting results were found with regard to the presence of chaotic behavior. Moreover, those studies focus mostly on ergodic networks in which initial states are assumed equally likely. We relax that assumption and find the critical condition for the sensitivity of the network under a non-ergodic scenario. We use the proposed mathematical model to determine parameter values for which phase transitions from order to chaos occur. We generate Derrida plots to show that the mathematical model matches the actual network dynamics. The phase transition diagrams indicate that both order and chaos can occur, and that certain parameters induce a larger range of values leading to order versus chaos. The edge-of-chaos curves are identified analytically and numerically. It is shown that the depth of canalization does not cause major dynamical changes once certain thresholds are reached; these thresholds are fairly small in comparison to the connectivity of the nodes.

  18. Hexagonal and nematic phases of chains. I - Correlation functions. II - Phase transitions

    NASA Technical Reports Server (NTRS)

    Selinger, Jonathan V.; Bruinsma, Robijn F.

    1991-01-01

    The statistical mechanics of a system of semiflexible chains, which can represent polymer liquid crystals, long-chain biomolecules, stiff wormlike micelles, or columns of discotic liquid crystals, are examined. A continuum theory is used to calculate static correlation functions in the hexagonal and nematic phases. Two correlation functions are considered: (1) the structure factor which describes fluctuations in the density; and (2) the director fluctuation spectrum, which describes fluctuations in the local optical axis. In addition, a model is developed for the phase transitions of a system of infinitely long, semiflexible chains which interact through a steric, excluded-volume repulsion. The model yields generic phase diagrams in terms of pressure or density vs. persistence length or temperature.

  19. Polyurea-functionalized multiwalled carbon nanotubes: synthesis, morphology, and Raman spectroscopy.

    PubMed

    Gao, Chao; Jin, Yi Zheng; Kong, Hao; Whitby, Raymond L D; Acquah, Steve F A; Chen, G Y; Qian, Huihong; Hartschuh, Achim; Silva, S R P; Henley, Simon; Fearon, Peter; Kroto, Harold W; Walton, David R M

    2005-06-23

    An in situ polycondensation approach was applied to functionalize multiwalled carbon nanotubes (MWNTs), resulting in various linear or hyperbranched polycondensed polymers [e.g., polyureas, polyurethanes, and poly(urea-urethane)-bonded carbon nanotubes]. The quantity of the grafted polymer can be easily controlled by the feed ratio of monomers. As a typical example, the polyurea-functionalized MWNTs were measured and characterized in detail. The oxidized MWNTs (MWNT-COOH) were converted into acyl chloride-functionalized MWNTs (MWNT-COCl) by reaction with neat thionyl chloride (SOCl2). MWNT-COCl was reacted with excess 1,6-diaminohexane, affording amino-functionalized MWNTs (MWNT-NH2). In the presence of MWNT-NH2, the polyurea was covalently coated onto the surfaces of the nanotube by in situ polycondensation of diisocyanate [e.g., 4,4'-methylenebis(phenylisocyanate)] and 1,6-diaminohexane, followed by the removal of free polymer via repeated filtering and solvent washing. The coated polyurea content can be controlled to some extent by adjusting the feed ratio of the isocyanato and amino groups. The structure and morphology of the resulting nanocomposites were characterized by FTIR, NMR, Raman, confocal Raman, TEM, EDS, and SEM measurements. The polyurea-coated MWNTs showed interesting self-assembled flat- or flowerlike morphologies in the solid state. The signals corresponding to that of the D and G bands of the carbon nanotubes were strongly attenuated after polyurea was chemically tethered to the MWNT surfaces. Comparative experiments showed that the grafted polymer species and structures have a strong effect on the Raman signals of polymer-functionalized MWNTs.

  20. Density functional theory study of hexagonal carbon phases.

    PubMed

    Wang, Zhibin; Gao, Faming; Li, Na; Qu, Nianrui; Gou, Huiyang; Hao, Xianfeng

    2009-06-10

    It is reported frequently that the new carbon phases may be harder than diamond (Wang et al 2004 Proc. Natl Acad. Sci. 101 13699 and Mao et al 2003 Science 302 425). However, the mechanism is still unclear. In this paper we systematically investigate the structural, electronic, and mechanical properties of the diamond polytypes using first-principles density functional calculations. The results show that the bulk modulus and shear modulus for the hexagonal form of diamond approach those of diamond, suggesting they might be hard and low compressibility materials. According to the semiempirical method for hardness based on the Mulliken overlap population, the hardnesses for hexagonal forms have been evaluated and compared to diamond. The results indicate that these phases are superhard. More importantly, the bonds in some specific directions of the hexagonal phases are harder than those in diamond, which may lead to the noticeable indentation marks on the diamond anvils observed in experiments.

  1. Preservation of the morphology of a self-encapsulated thin titania film in a functional multilayer stack: an X-ray scattering study.

    PubMed

    Perlich, Jan; Memesa, Mine; Diethert, Alexander; Metwalli, Ezzeldin; Wang, Weinan; Roth, Stephan V; Timmann, Andreas; Gutmann, Jochen S; Müller-Buschbaum, Peter

    2009-03-23

    Tailoring of the titania morphology is achieved by the combination of a triblock copolymer, acting as structure-directing agent, and a sol-gel chemistry enabling the incorporation of the provided inorganic material (titania) into the selected phase of the triblock copolymer. Spin-coating of the solution on FTO-coated glass, followed by plasma etching and calcination of the thin film results in the formation of self-encapsulated crystalline titania nanostructures. The fabricated nanostructures are coated stepwise with dye, conductive polymers and gold forming a functional multilayer stack. An advanced small-angle scattering technique probing the sample with X-ray synchrotron radiation under grazing incidence (GISAXS) is employed for the characterization of the preparation route, as scattering allows accessing the structure inside the multilayers. The tailored titania morphology is preserved during the preparation route towards the functional multilayer stack of a photovoltaic demonstration cell. Two clearly distinguishable structures originate from the substrate and the titania templated by the triblock copolymer; hence the other layers induce no additional structures. Therefore, this investigation provides the evidence that the effort spent to tailor the morphology is justified by the preservation of the self-encapsulated titania morphology that is created by the structure-directing agent throughout the functional multilayer stack build-up.

  2. Morphological and functional reversal of phenotypes in a mouse model of Rett syndrome.

    PubMed

    Robinson, Lianne; Guy, Jacky; McKay, Leanne; Brockett, Emma; Spike, Rosemary C; Selfridge, Jim; De Sousa, Dina; Merusi, Cara; Riedel, Gernot; Bird, Adrian; Cobb, Stuart R

    2012-09-01

    Rett syndrome is a neurological disorder caused by mutation of the X-linked MECP2 gene. Mice lacking functional Mecp2 display a spectrum of Rett syndrome-like signs, including disturbances in motor function and abnormal patterns of breathing, accompanied by structural defects in central motor areas and the brainstem. Although routinely classified as a neurodevelopmental disorder, many aspects of the mouse phenotype can be effectively reversed by activation of a quiescent Mecp2 gene in adults. This suggests that absence of Mecp2 during brain development does not irreversibly compromise brain function. It is conceivable, however, that deep-seated neurological defects persist in mice rescued by late activation of Mecp2. To test this possibility, we have quantitatively analysed structural and functional plasticity of the rescued adult male mouse brain. Activation of Mecp2 in ∼70% of neurons reversed many morphological defects in the motor cortex, including neuronal size and dendritic complexity. Restoration of Mecp2 expression was also accompanied by a significant improvement in respiratory and sensory-motor functions, including breathing pattern, grip strength, balance beam and rotarod performance. Our findings sustain the view that MeCP2 does not play a pivotal role in brain development, but may instead be required to maintain full neurological function once development is complete.

  3. Functional morphology underlies performance differences among invasive and non-invasive ruderal Rubus species.

    PubMed

    Caplan, Joshua S; Yeakley, J Alan

    2013-10-01

    The ability of some introduced plant species to outperform native species under altered resource conditions makes them highly productive in ecosystems with surplus resources. However, ruderal native species are also productive when resources are available. The differences in abundance among invasive and non-invasive ruderal plants may be related to differences in ability to maintain access to or store resources for continual use. For a group of ruderal species in the Pacific Northwest of North America (invasive Rubus armeniacus; non-invasive R. ursinus, R. parviflorus, R. spectabilis, and Rosa nutkana), we sought to determine whether differences in functional morphological traits, especially metrics of water access and storage, were consistent with differences in water conductance and growth rate. We also investigated the changes in these traits in response to abundant vs. limited water availability. Rubus armeniacus had among the largest root systems and cane cross-sectional areas, the lowest cane tissue densities, and the most plastic ratios of leaf area to plant mass and of xylem area to leaf area, often sharing its rank with R. ursinus or Rosa nutkana. These three species had the highest water conductance and relative growth rates, though Rubus armeniacus grew the most rapidly when water was not limited. Our results suggest that water access and storage abilities vary with morphology among the ruderal species investigated, and that these abilities, in combination, are greatest in the invasive. In turn, functional morphological traits allow R. armeniacus to maintain rapid gas exchange rates during the dry summers in its invaded range, conferring on it high productivity.

  4. Adapted to roar: functional morphology of tiger and lion vocal folds.

    PubMed

    Klemuk, Sarah A; Riede, Tobias; Walsh, Edward J; Titze, Ingo R

    2011-01-01

    Vocal production requires active control of the respiratory system, larynx and vocal tract. Vocal sounds in mammals are produced by flow-induced vocal fold oscillation, which requires vocal fold tissue that can sustain the mechanical stress during phonation. Our understanding of the relationship between morphology and vocal function of vocal folds is very limited. Here we tested the hypothesis that vocal fold morphology and viscoelastic properties allow a prediction of fundamental frequency range of sounds that can be produced, and minimal lung pressure necessary to initiate phonation. We tested the hypothesis in lions and tigers who are well-known for producing low frequency and very loud roaring sounds that expose vocal folds to large stresses. In histological sections, we found that the Panthera vocal fold lamina propria consists of a lateral region with adipocytes embedded in a network of collagen and elastin fibers and hyaluronan. There is also a medial region that contains only fibrous proteins and hyaluronan but no fat cells. Young's moduli range between 10 and 2000 kPa for strains up to 60%. Shear moduli ranged between 0.1 and 2 kPa and differed between layers. Biomechanical and morphological data were used to make predictions of fundamental frequency and subglottal pressure ranges. Such predictions agreed well with measurements from natural phonation and phonation of excised larynges, respectively. We assume that fat shapes Panthera vocal folds into an advantageous geometry for phonation and it protects vocal folds. Its primary function is probably not to increase vocal fold mass as suggested previously. The large square-shaped Panthera vocal fold eases phonation onset and thereby extends the dynamic range of the voice.

  5. Primary orbital fracture repair: development and validation of tools for morphologic and functional analysis.

    PubMed

    Hontscharuk, Rayisa; Fialkov, Jeffrey A; Binhammer, Paul A; McMillan, Catherine R; Antonyshyn, Oleh

    2012-07-01

    The purpose of this study was to develop and validate a technique for objective quantitative evaluation of outcomes of orbital reconstruction. Facial three-dimensional images were captured using a Vectra three-dimensional camera. Morphometric analysis was based on interactive anthropometric identification. The analysis was applied to a population of healthy adults (n = 13) and a population of patients following primary repair of unilateral orbital fractures (n = 13). Morphologic results following reconstruction were evaluated by identifying residual asymmetries. All subjects further completed the Derriford Appearance Questionnaire and the Orbital Appearance and Function Questionnaire.Normative reference values for periorbital asymmetry were determined in a reference population. The mean asymmetry was less than 1.6 mm for each measured morphologic feature. In the trauma population, primary orbital reconstruction effectively restored normal periorbital symmetry in 16 of 20 measured parameters. The fracture population showed no significant differences in the degree of asymmetry in globe projection, lower eyelid position, or ciliary margin length.The overall DAS59 scores were significantly higher in the fracture population (P = 0.04). This was due to significantly higher physical distress and dysfunction scores (P = 0.02), as well as a trend toward higher general and social self-consciousness scores (P = 0.06). No significant difference in facial self-consciousness was noted (P = 0.21). Thus, although primary orbital reconstruction was effective in restoring periorbital morphology, patients still experienced a higher level of physical distress and dysfunction than their nontraumatized counterparts. This was in accordance with patient self-report, which indicated that a greater percentage of patients were significantly bothered by functional outcomes postoperatively as opposed to appearance.

  6. A two phase harmonic model for left ventricular function.

    PubMed

    Dubi, Shay; Dubi, Chen; Dubi, Yonatan

    2007-11-01

    A minimal model for mechanical motion of the left ventricle is proposed. The model assumes the left ventricle to be a harmonic oscillator with two distinct phases, simulating the systolic and diastolic phases, at which both the amplitude and the elastic constant of the oscillator are different. Taking into account the pressure within the left ventricle, the model shows qualitative agreement with functional parameters of the left ventricle. The model allows for a natural explanation of heart failure with preserved systolic left ventricular function, also termed diastolic heart failure. Specifically, the rise in left ventricular filling pressures following increased left-ventricular wall stiffness is attributed to a mechanism aimed at preserving heart rate and cardiac output.

  7. Importance of Tissue Morphology Relative to Patient Reports of Symptoms and Functional Limitations Resulting From Median Nerve Pathology

    PubMed Central

    Evans, Kevin D.; Li, Xiaobai; Sommerich, Carolyn M.; Case-Smith, Jane

    2013-01-01

    Significant data exist for the personal, environmental, and occupational risk factors for carpal tunnel syndrome. Few data, however, explain the interrelationship of tissue morphology to these factors among patients with clinical presentation of median nerve pathology. Therefore, our primary objective was to examine the relationship of various risk factors that may be predictive of subjective reports of symptoms or functional deficits accounting for median nerve morphology. Using diagnostic ultrasonography, we observed real-time median nerve morphology among 88 participants with varying reports of symptoms or functional limitations resulting from median nerve pathology. Body mass index, educational level, and nerve morphology were the primary predictive factors. Monitoring median nerve morphology with ultrasonography may provide valuable information for clinicians treating patients with symptoms of median nerve pathology. Sonographic measurements may be a useful clinical tool for improving treatment planning and provision, documenting patient status, or measuring clinical outcomes of prevention and rehabilitation interventions. PMID:23245784

  8. Isolation and partial characterization of mango (Magnifera indica L.) starch: morphological, physicochemical and functional studies.

    PubMed

    Bello-Pérez, L A; Aparicio-Saguilán, A; Méndez-Montealvo, G; Solorza-Feria, J; Flores-Huicochea, E

    2005-03-01

    Mango (Mangifera indica) is a fruit that grows in tropical regions. The aim of this work was to isolate the starch from two varieties of mango highly consumed in Mexico ("criollo" and "manila"), and to evaluate its chemical composition, along with some morphological, physicochemical and functional properties. Mango starch had an amylose content of about 13%, the fat content of "criollo" variety starch (0.1-0.12%), was similar to that of commercial corn starch used as control (0.2%); both mango starches had higher ash amount (0.2-0.4%) than corn starch. Mango starches presented a smaller granule size (10 microm) than corn starch (15 microm), along with an A-type X-ray diffraction pattern with slight tendency to a C-type. All values of water retention capacity (WRC) increased with the temperature. When the temperature increased, solubility and swelling values increased and in general, mango starches had higher values than corn starch. Both mango starches had gelatinization temperatures lower than the control, but "criollo" variety starch presented higher enthalpy values than "manila" variety and corn starches. Overall, it was concluded that due to its morphological, physicochemical and functional properties, mango starches could be a feasible starch source with adequate properties, suitable for using in the food industry.

  9. Development and functional morphology of the larval foregut of two brachyuran species from Northern Brazil.

    PubMed

    Abrunhosa, Fernando A; Simith, Darlan J B; Monteiro, Joely R C; Souza Junior, Antonio N de; Oliva, Pedro A C

    2011-12-01

    Feeding is an important factor for the successful rearing of larvae of the crab species. Further information on the morphological features of the foregut may to reveal larval feeding behaviour and or/whether there is a lecithotrophy in some or even in all stages of the larval cycle. In the present study, the structural development of the foregut and their digestive functions were examined in larvae of two brachyurans, Uca vocator and Panopeus occidentalis, reared in the laboratory. During larval development, the foreguts of the larvae in the first and last zoeal stages and in the megalopa stage were microscopically examined, described and illustrated. The zoeal foreguts of both species were well developed, showing specialization with a functional cardiopyloric valve and a filter press. The megalopa stage had a complex and specialized gastric mill similar to that found in adult crabs with the appearance of rigidly calcified structures. These results support the hypothesis that the feeding behaviour of each larval stage is directly related to the morphological structure of the foregut. Such facts strongly indicate that all larval stages of both U. vocator and P. occidentalis need an external food source before completing the larval development in a planktonic environment.

  10. Morphological and functional development of the interbranchial lymphoid tissue (ILT) in Atlantic salmon (Salmo salar L).

    PubMed

    Dalum, Alf Seljenes; Griffiths, David James; Valen, Elin Christine; Amthor, Karoline Skaar; Austbø, Lars; Koppang, Erling Olaf; Press, Charles McLean; Kvellestad, Agnar

    2016-11-01

    The interbranchial lymphoid tissue (ILT) of Atlantic salmon originates from an embryological location that in higher vertebrates gives rise to both primary and secondary lymphoid tissues. Still much is unknown about the morphological and functional development of the ILT. In the present work a standardized method of organ volume determination was established to study its development in relation to its containing gill and the thymus. Based on morphological findings and gene transcription data, the ILT shows no signs of primary lymphoid function. In contrast to the thymus, an ILT-complex first became discernible after the yolk-sac period. After its appearance, the ILT-complex constitutes 3-7% of the total volume of the gill (excluding the gill arch) with the newly described distal ILT constituting a major part, and in adult fish it is approximately 13 times larger than the thymus. Confined regions of T-cell proliferation are present within the ILT. Communication with systemic circulation through the distal ILT is also highly plausible thus offering both internal and external recruitment of immune cells in the growing ILT.

  11. Renal morphology and function immediately after extracorporeal shock-wave lithotripsy

    SciTech Connect

    Kaude, J.V.; Williams, C.M.; Millner, M.R.; Scott, K.N.; Finlayson, B.

    1985-08-01

    The acute effects of extracorporeal shock-wave lithotripsy (ESWL) on morphology and function of the kidney were evaluated by excretory urography, quantitative radionuclide renography (QRR), and magnetic resonance imaging (MRI) in 33 consecutive patients. Excretory urograms demonstrated an enlarged kidney in seven (18%) of 41 treatments and partial or complete obstruction of the ureter by stone fragments after 15 (37%) of 41 treatments. Total effective renal plasma flow (ERPF) was not changed after ESWL, but the percentage ERPF of the treated kidney was decreased by more than 5% in 10 (30%) of 33 cases. QRR images showed partial parenchymal obstruction in 10 (25%) of 41 teated kidneys and total parenchymal obstruction in 9 (22%). MRI disclosed one or more abnormalities in 24 (63%) of 38 treated kidneys. Treated kidneys were normal by all three imaging methods in 26% and abnormal by one or more tests in 74% of cases. The morphologic and functional changes are attributed to renal contusion resulting in edema and extravasation of urine and blood into the interstitial, subcapsular, and perirenal spaces.

  12. Morphological integration in the hominin dentition: evolutionary, developmental, and functional factors.

    PubMed

    Gómez-Robles, Aida; Polly, P David

    2012-04-01

    As the most common and best preserved remains in the fossil record, teeth are central to our understanding of evolution. However, many evolutionary analyses based on dental traits overlook the constraints that limit dental evolution. These constraints are diverse, ranging from developmental interactions between the individual elements of a homologous series (the whole dentition) to functional constraints related to occlusion. This study evaluates morphological integration in the hominin dentition and its effect on dental evolution in an extensive sample of Plio- and Pleistocene hominin teeth using geometric morphometrics and phylogenetic comparative methods. Results reveal that premolars and molars display significant levels of covariation; that integration is stronger in the mandibular dentition than in the maxillary dentition; and that antagonist teeth, especially first molars, are strongly integrated. Results also show an association of morphological integration and evolution. Stasis is observed in elements with strong functional and/or developmental interactions, namely in first molars. Alternatively, directional evolution (and weaker integration) occurs in the elements with marginal roles in occlusion and mastication, probably in response to other direct or indirect selective pressures. This study points to the need to reevaluate hypotheses about hominin evolution based on dental characters, given the complex scenario in which teeth evolve.

  13. The fish tail as a derivation from axial musculoskeletal anatomy: an integrative analysis of functional morphology.

    PubMed

    Flammang, B E

    2014-02-01

    The adult morphology of the tail varies greatly among extant fishes despite sharing both ontogenetic similarities and the functional need to propel the body through a fluid medium. Both sharks (Chondrichthyes) and ray-finned fishes (Actinopterygii) control caudal fin musculature independently of axial body myomere activity to modify the stiffness and shape of their tails. For example, sharks and bony fishes possess different structural elements and muscles and move their tails in different ways, resulting in different locomotory hydrodynamic effects and a range of performance variables including speed and maneuverability. The stiffness of the heterocercal, lobate tail of the shark can be modulated during the tail beat resulting in nearly continuous thrust production. In contrast, the highly flexible tail of ray-finned fishes can be manipulated into many different shape conformations enabling increased maneuverability for these fishes. Consequently, the developmental, morphological, and functional derivation of the tail from the axial trunk has resulted in a diversity of form, the attributes of which may be of ecological and evolutionary significance.

  14. Crystalline molecular machines: function, phase order, dimensionality, and composition.

    PubMed

    Vogelsberg, Cortnie S; Garcia-Garibay, Miguel A

    2012-03-07

    The design of molecular machines is stimulated by the possibility of developing new materials with complex physicochemical and mechanical properties that are responsive to external stimuli. Condensed-phase matter with anisotropic molecular order and controlled dynamics, also defined as amphidynamic crystals, offers a promising platform for the design of bulk materials capable of performing such functions. Recent studies have shown that it is possible to engineer molecular crystals and extended solids with Brownian rotation about specific axes that can be interfaced with external fields, which may ultimately be used to design novel optoelectronic materials. Structure/function relationships of amphidynamic materials have been characterized, establishing the blueprints to further engineer sophisticated function. However, the synthesis of amphidynamic molecular machines composed of multiple "parts" is essential to realize increasingly complex behavior. Recent progress in amphidynamic multicomponent systems suggests that sophisticated functions similar to those of simple biomolecular machines may eventually be within reach.

  15. Development and functional morphology of the foreguts of larvae and postlarvae of three crustacean decapods.

    PubMed

    Abrunhosa, F; Melo, M

    2008-02-01

    The development of the foregut structure and the digestive function of the decapods Litopenaeus vannamei, Sesarma rectum and Callichirus major larvae and post larvae were examined. The protozoeal foregut of L. vannamei is simple, lacking a cardiopyloric valve and bearing a rudimentary filter press. In mysis, the filter press is more developed. In the juvenile stage, grooves and a small lateral tooth arise. In S. rectum, the foregut has a functional cardiopyloric valve and a filter press. The megalopal and juvenile stages of this species have a gastric mill similar to those in adult crabs. In C. major, the foregut of the zoeae is specialized, with the appearance of some rigid structures, but no gastric mill was found. Calcified structures are observed in the megalopae and they become more developed in the juvenile stage. The results support suppositions, previously reported in other studies, that feeding behavior of each larval and postlarval stage is directly related to the morphological characteristics of the foreguts.

  16. Morphologic, cytometric and functional characterization of the common octopus (Octopus vulgaris) hemocytes.

    PubMed

    Castellanos-Martínez, S; Prado-Alvarez, M; Lobo-da-Cunha, A; Azevedo, C; Gestal, C

    2014-05-01

    The hemocytes of Octopus vulgaris were morphologically and functionally characterized. Light and electron microscopy (TEM and SEM), and flow cytometry analyses revealed the existence of two hemocyte populations. Large granulocytes showed U-shaped nucleus, a mean of 11.6 μm±1.2 in diameter with basophilic granules, polysaccharide and lysosomic deposits in the cytoplasm. Small granulocytes measured a mean of 8.1 μm±0.7 in diameter, and have a round nucleus occupying almost the entire cell and few or not granules in the cytoplasm. Flow cytometry analysis showed that large granulocytes are the principal cells that develop phagocytosis of latex beads (rising up to 56%) and ROS after zymosan stimulation. Zymosan induced the highest production of both ROS and NO. This study is the first tread towards understanding the O. vulgaris immune system by applying new tools to provide a most comprehensive morpho-functional study of their hemocytes.

  17. Ultrastructure and functional morphology of the female reproductive organs in Protodrilus (Polychaeta, Annelida)

    NASA Astrophysics Data System (ADS)

    von Nordheim, Henning

    1991-12-01

    The morphology and function of the female reproductive organs in 6 Protodrilus species are investigated by light- and transmission electron microscopy. Possible ways in which spermatozoa may enter the female coelom after leaving the spermatophore are discussed for species with and without special female reception organs. Only female P. rubropharyngeus and P. flavocapitatus have “dorsal organs” for spermatophore reception. The structure and function of these organs are described, as well as those of the oviduct found in 3 of the species investigated. The possible phylogenetic origin of gonoducts and different modes of oviposition within the genus are discussed. Finally, the high taxonomic significance of female traits such as dorsal organs, oviducts, cocoon glands and lateral ciliary rows in this genus is stressed.

  18. Functional and morphological alterations associated with working memory dysfunction in patients with generalized anxiety disorder.

    PubMed

    Moon, Chung-Man; Jeong, Gwang-Woo

    2017-03-01

    Background Generalized anxiety disorder (GAD) has been related to functional brain activities and structural brain abnormalities. Purpose To investigate the neural mechanism on working memory dysfunction in patients with GAD in terms of the combined functional and morphological brain abnormalities. Material and Methods Patients with GAD and healthy controls matched for age, sex, and education level underwent high-resolution T1-weighted (T1W) magnetic resonance imaging (MRI) and functional MRI (fMRI). In this study, fMRI and voxel-based morphometry (VBM) were used for assessing the differential brain activation patterns, as well as for comparing the morphological alterations between the two groups. Results In response to the neutral distractors, the patients showed significantly lower activities in the regions of the fusiform gyrus (FuG), superior parietal gyrus (SPG), precuneus (PCu), superior occipital gyrus (SOG), lingual gyrus (LiG), cuneus (Cun), calcarine cortex (CaC), parahippocampal gyrus (PHG) and cerebellar cortex (Cb) compared to the controls. In response to the anxiety-inducing distractors, the patients showed significantly higher activity in the hippocampus and lower activities in the regions of the dorsolateral prefrontal cortex (DLPFC), FuG, SPG, PCu, SOG, and Cb. Also, the patients showed a significant reduction of the white matter volumes in the DLPFC, anterior limb of the internal capsule (ALIC) and midbrain. Conclusion This study provides the first evidence for the association between the morphometric alterations and functional deficit in the working memory processing with the neutral and anxiety-inducing distractors in GAD patients. These findings would be helpful to understand the neural mechanisms on working memory impairment in connection with GAD symptoms.

  19. Morphology phase diagram of ultrathin anatase TiO2 films templated by a single PS-b-PEO block copolymer.

    PubMed

    Cheng, Ya-Jun; Gutmann, Jochen S

    2006-04-12

    Ultrathin TiO2 films showing rich morphologies are prepared on Si(100) substrates using sol-gel chemistry coupled with an amphilic polystyrene-block-poly(ethylene oxide) (PS-b-PEO) diblock copolymer as a structure-directing agent. The block copolymer undergoes a good-poor solvent pair induced phase separation in a mixed solution of 1,4-dioxane, concentrated hydrochloric acid (HCl), and titanium tetraisopropoxide (TTIP). By adjusting the weight fractions of 1,4-dioxane, HCl, and TTIP, inorganic block copolymer composite films containing a variety of different morphologies are obtained. On the basis of the results a ternary phase diagram of the morphologies is mapped. By calcination, anatase TiO2 films are achieved. The morphologies and crystallographic phase of the films are studied with AFM, SEM, and XRD, respectively, and the formation mechanisms of the different morphologies are discussed.

  20. Morphological examination of highly porous polylactic acid/Bioglass(®) scaffolds produced via nonsolvent induced phase separation.

    PubMed

    Rezabeigi, Ehsan; Wood-Adams, Paula M; Drew, Robin A L

    2016-09-19

    In this study, we produce highly porous (up to ∼91%) composite scaffolds of polylactic acid (PLA) containing 2 wt % sol-gel-derived 45S5 Bioglass(®) particles via nonsolvent induced phase separation at -23°C with no sacrificial phases involved. Before the incorporation of the bioglass with PLA, the particles are surface modified with a silane coupling agent which effectively diminishes agglomeration between them leading to a better dispersion of bioactive particles throughout the scaffold. Interestingly, the incorporation route (via solvent dichloromethane or nonsolvent hexane) of the surface modified particles in the foaming process has the greatest impact on porosity, crystallinity, and morphology of the scaffolds. The composite scaffolds with a morphology consisting of both mesopores and large macropores, which is potentially beneficial for bone regeneration applications, are examined further. SEM images show that the surface modified bioglass particles take-up a unique configuration within the mesoporous structure of these scaffolds ensuring that the particles are well interlocked but not completely covered by PLA such that they can be in contact with physiological fluids. The results of preliminary in vitro tests confirm that this PLA/bioglass configuration promotes the interaction of the bioactive phase with physiological fluids. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2016.

  1. Astrocyte morphology is confined by cortical functional boundaries in mammals ranging from mice to human

    PubMed Central

    Eilam, Raya; Aharoni, Rina; Arnon, Ruth; Malach, Rafael

    2016-01-01

    Cortical blood flow can be modulated by local activity across a range of species; from barrel-specific blood flow in the rodent somatosensory cortex to the human cortex, where BOLD-fMRI reveals numerous functional borders. However, it appears that the distribution of blood capillaries largely ignores these functional boundaries. Here we report that, by contrast, astrocytes, a major player in blood-flow control, show a striking morphological sensitivity to functional borders. Specifically, we show that astrocyte processes are structurally confined by barrel boundaries in the mouse, by the border of primary auditory cortex in the rat and by layers IIIa/b and Cytochrome Oxidase (CO)-blobs boundaries in the human primary visual cortex. Thus, astrocytes which are critical elements in neuro-hemodynamic coupling show a significant anatomical segregation along functional boundaries across different mammalian species. These results may open a new anatomical marker for delineating functional borders across species, including post-mortem human brains. DOI: http://dx.doi.org/10.7554/eLife.15915.001 PMID:27282388

  2. Morphology and function of cryopreserved whole ovine ovaries after heterotopic autotransplantation

    PubMed Central

    Grazul-Bilska, Anna T; Banerjee, Jashoman; Yazici, Ilker; Borowczyk, Ewa; Bilski, Jerzy J; Sharma, Rakesh K; Siemionov, Maria; Falcone, Tommaso

    2008-01-01

    Background The objective of this study was to perform complex characterization of cryopreserved and then autotransplanted ovaries including determination of the ability to respond to in vivo follicle stimulating hormone (FSH)-treatment, fertilizability of retrieved oocytes, and morphology, vascularization, cellular proliferation and apoptosis in sheep. Methods Mature crossbred ewes were divided into two groups; an intact (control) group (n = 4), and autotransplanted group (n = 4) in which oophorectomy was performed laparoscopically and ovaries with intact vascular pedicles frozen, thawed and transplanted back into the same animal at a different site. Approximately five months after autotransplantation, estrus was synchronized, ewes were treated with FSH, and ovaries were collected. For all ovaries, number of visible follicles was determined, and collected cumulus oocyte complexes (COC) were matured and fertilized in vitro. Remaining ovarian tissues were fixed for evaluation of morphology, expression of factor VIII (marker of endothelial cells), vascular endothelial growth factor (VEGF; expressed by pericytes and smooth muscle cells), and smooth muscle cell actin (SMCA; marker of pericytes and smooth muscle cells), and cellular proliferation and apoptosis. Two fully functional ovaries were collected from each control ewe (total 8 ovaries). Results Out of eight autotransplanted ovaries, a total of two ovaries with developing follicles were found. Control ewes had 10.6 +/- 2.7 follicles/ovary, oocytes were in vitro fertilized and developed to the blastocyst stage. One autotransplanted ewe had 4 visible follicles from which 3 COC were collected, but none of them was fertilized. The morphology of autotransplanted and control ovaries was similar. In control and autotransplanted ovaries, primordial, primary, secondary, antral and preovulatory follicles were found along with fully functional vascularization which was manifested by expression of factor VIII, VEGF and SMCA

  3. Growth evolution and phase transition from chalcocite to digenite in nanocrystalline copper sulfide: Morphological, optical and electrical properties

    PubMed Central

    Quintana-Ramirez, Priscilla Vasthi; Santos-Cruz, José; Vega-González, Marina; Martínez-Alvarez, Omar; Castaño-Meneses, Víctor Manuel; Acosta-Torres, Laura Susana; de la Fuente-Hernández, Javier

    2014-01-01

    Summary Copper sulfide is a promising p-type inorganic semiconductor for optoelectronic devices such as solar cells, due its small band gap energy and its electrical properties. In this work nanocrystalline copper sulfide (CuxS), with two stoichiometric ratios (x = 2, 1.8) was obtained by one-pot synthesis at 220, 230, 240 and 260 °C in an organic solvent and amorphous CuxS was obtained in aqueous solution. Nanoparticle-like nucleation centers are formed at lower temperatures (220 °C), mixtures of morphologies (nanorods, nanodisks and nanoprisms) are seen at 230 and 240 °C, in which the nanodisks are predominant, while big hexagonal/prismatic crystals are obtained at 260 °C according to TEM results. A mixture of chalcocite and digenite phases was found at 230 and 240 °C, while a clear transition to a pure digenite phase was seen at 260 °C. The evolution of morphology and transition of phases is consistent to the electrical, optical, and morphological properties of the copper sulfide. In fact, digenite Cu1.8S is less resistive (346 Ω/sq) and has a lower energy band gap (1.6 eV) than chalcocite Cu2S (5.72 × 105 Ω/sq, 1.87 eV). Low resistivity was also obtained in CuxS synthesized in aqueous solution, despite its amorphous structure. All CuxS products could be promising for optoelectronic applications. PMID:25247136

  4. Growth evolution and phase transition from chalcocite to digenite in nanocrystalline copper sulfide: Morphological, optical and electrical properties.

    PubMed

    Quintana-Ramirez, Priscilla Vasthi; Arenas-Arrocena, Ma Concepción; Santos-Cruz, José; Vega-González, Marina; Martínez-Alvarez, Omar; Castaño-Meneses, Víctor Manuel; Acosta-Torres, Laura Susana; de la Fuente-Hernández, Javier

    2014-01-01

    Copper sulfide is a promising p-type inorganic semiconductor for optoelectronic devices such as solar cells, due its small band gap energy and its electrical properties. In this work nanocrystalline copper sulfide (Cu x S), with two stoichiometric ratios (x = 2, 1.8) was obtained by one-pot synthesis at 220, 230, 240 and 260 °C in an organic solvent and amorphous Cu x S was obtained in aqueous solution. Nanoparticle-like nucleation centers are formed at lower temperatures (220 °C), mixtures of morphologies (nanorods, nanodisks and nanoprisms) are seen at 230 and 240 °C, in which the nanodisks are predominant, while big hexagonal/prismatic crystals are obtained at 260 °C according to TEM results. A mixture of chalcocite and digenite phases was found at 230 and 240 °C, while a clear transition to a pure digenite phase was seen at 260 °C. The evolution of morphology and transition of phases is consistent to the electrical, optical, and morphological properties of the copper sulfide. In fact, digenite Cu1.8S is less resistive (346 Ω/sq) and has a lower energy band gap (1.6 eV) than chalcocite Cu2S (5.72 × 10(5) Ω/sq, 1.87 eV). Low resistivity was also obtained in Cu x S synthesized in aqueous solution, despite its amorphous structure. All Cu x S products could be promising for optoelectronic applications.

  5. Changes in motility, ATP content, morphology and fertilisation capacity during the movement phase of tetraploid Pacific oyster (Crassostrea gigas) sperm.

    PubMed

    Suquet, M; Labbe, C; Brizard, R; Donval, A; Le Coz, J R; Quere, C; Haffray, P

    2010-07-01

    Changes in sperm features during the movement phase are especially interesting to study in external fertilization species whose sperm duration movement is long because this implies a significant adaptation of moving cells to the external medium. This study describes the changes in tetraploid Pacific oyster sperm characteristics in relation to time post activation. Sperm individually collected on three tetraploid males were activated in seawater. Their features were analysed over a 24h period and compared to a sperm pool collected on three diploid males as a reference. The percentage of motile spermatozoa, the intracellular ATP content, and the fine structure of spermatozoa were studied in relation to time post activation. Furthermore, the fertilisation capacity of sperm individually collected on five diploid males was assessed after 1 and 24h post activation. A forward progressive movement was maintained for at least a 20h duration. Compared to diploid males, the percentage of motile spermatozoa was lower in tetraploid males. The intracellular ATP concentration was higher in spermatozoa from tetraploid males than in spermatozoa from diploid males. A decrease in ATP content was observed in the first 6h post activation and severe alterations were observed in sperm morphology after 24h. Then, a lower fertilisation capacity of sperm from diploid males was observed at the end of the movement phase. The cessation of Pacific oyster sperm motility was unlikely caused by ATP consumption as ATP concentration was still high at the end of sperm movement but rather caused by drastic changes in sperm morphology. Compared to sperm collected on diploid males, the lower quality of sperm from tetraploid males was emphasized by a shorter movement duration and deeper morphological alterations at the end of the movement phase.

  6. Phase transitions, magnetism and surface adsorptions assessed by meta-GGA functionals and random phase approximation

    NASA Astrophysics Data System (ADS)

    Xiao, Bing

    The meta-GGA functionals and random phase approximation are tested for phase transitions and a strongly correlated transition metal oxide in this dissertation. One of the latest meta-GGA functionals is also employed to study the van der Waals bound system in surface science. Our main purpose is to reveal the performance of new exchange-correlation functionals on various properties and systems. We are also interested in seeking the possible relationship between the performance of a semilocal functional and its exchange enhancement factor. We have studied the structural phase transitions in crystalline Si (insulator to metal), SiO2 (insulator to insulator) and Zr (metal to metal) systems, as a test of exchange energy semilocal functionals on Jacob's ladder. Our results confirm the energy-geometry delimma of GGAs in three systems. The most sophisticated non-empirical meta-generalized gradient approximations (meta-GGAs) such as TPSS (Tao-Perdew-Staroveov-Scuseria) and revTPSS (revised TPSS) give better lattice constants than PBE, but the phase transition parameters (energy difference and transition pressure) are smaller and less realistic than those from the latter GGA. However, the recent functionals of meta-GGA made simple family (MGGA_MS) behave differently to those previous meta-GGAs, predicting larger and more realistic phase transition parameters. Meanwhile, MGGA_MS also delivers the equilibrium geometry of crystalline materials similar to previous non-empirical meta-GGAs. In contrast to semilocal functionals, the nonlocal functionals such as the range-separated hybrid functional HSE06 (Heyd-Scuseria-Ernzerhof) and non-self consistent random phase approximation (RPA) are not only able to give the accurate equilibrium geometry , but also predict the realistic phase transition parameters for Si and SiO2 systems. The ground state of rutile-type vanadium dioxide (R-VO2) represents a great challenge to the current density functional theory. In this dissertation, we

  7. Direct 3D visualization of the phase-separated morphology in chlorinated polyethylene/nylon terpolyamide based thermoplastic elastomers.

    PubMed

    Crisenza, Tommaso; Butt, Hans-Jürgen; Koynov, Kaloian; Simonutti, Roberto

    2012-01-01

    Blends of chlorinated polyethylene and nylon-6/-6,6/-12 terpolyamide were prepared. The ratio of the two components was systematically varied within the blends. The mechanical behavior of the samples was analyzed with tensile tests and dynamical mechanical analysis showing that, for several ratios, materials with improved mechanical properties typical of thermoplastic elastomers were obtained. In such a mechanical regime, a co-continuous phase-separated morphology was clearly evidenced at the microscopic scale by 3D laser scanning confocal fluorescent microscopy (LSCFM). At blend compositions where plastic tensile behavior is observed, LSCFM reveals dispersed spheres of one component in the other.

  8. Interface morphology studies of liquid phase epitaxy grown HgCdTe films by atomic force microscopy

    NASA Astrophysics Data System (ADS)

    Azoulay, M.; George, M. A.; Burger, A.; Collins, W. E.; Silberman, E.

    1994-04-01

    In this paper we report an investigation of the morphology of the interfaces of liquid phase epitaxy (LPE) grown HgCdTe thin films on CdTe and CdZnTe substrates by atomic force microscopy (AFM) on freshly cleaved (110) crystallographic planes. An empirical observation which may be linked to lattice mismatch was indicated by an angle between the cleavage steps of the substrate to those of the film. The precipitates with size ranging from 5 nm to 20 nm were found to be most apparent near the interface.

  9. Caspofungin Affects Growth of Paracoccidioides brasiliensis in Both Morphological Phases ▿ †

    PubMed Central

    Rodríguez-Brito, Sabrina; Niño-Vega, Gustavo; San-Blas, Gioconda

    2010-01-01

    Five Paracoccidioides brasiliensis isolates were grown in the presence of caspofungin (0 to 1 μg/ml). Inhibition of the yeast phase ranged from 20 to 65%, while in the mycelial form it ranged from 75% to 82%. Such variability was loosely related to the amount of cell wall β-1,3-glucan. No association with point mutations in the β-1,3-glucan synthase was detected. Caspofungin induced physical changes and cytoplasmic deterioration in both fungal phases. PMID:20937789

  10. Functional morphology and wasp pollination of two South American asclepiads (Asclepiadoideae–Apocynaceae)

    PubMed Central

    Wiemer, A. P.; Sérsic, A. N.; Marino, S.; Simões, A. O.; Cocucci, A. A.

    2012-01-01

    Background and Aims The extreme complexity of asclepiad flowers (Asclepiadoideae–Apocynaceae) has generated particular interest in the pollination biology of this group of plants especially in the mechanisms involved in the pollination processes. This study compares two South American species, Morrenia odorata and Morrenia brachystephana, with respect to morphology and anatomy of flower structures, dynamic aspects of the pollination mechanism, diversity of visitors and effectiveness of pollinators. Methods Floral structure was studied with fresh and fixed flowers following classical techniques. The pollination mechanism was studied by visiting fresh flowers in the laboratory with artificial pollinator body parts created with an eyelash. Morphometric and nectar measurements were also taken. Pollen transfer efficiency in the flowers was calculated by recording the frequency of removed and inserted pollinia. Visitor activity was recorded in the field, and floral visitors were captured for subsequent analysis of pollen loads. Finally, pollinator effectiveness was calculated with an index. Key Results The detailed structure of the flowers revealed a complex system of guide rails and chambers precisely arranged in order to achieve effective pollinaria transport. Morrenia odorata is functionally specialized for wasp pollination, and M. brachystephana for wasp and bee pollination. Pollinators transport chains of pollinaria adhered to their mouthparts. Conclusions Morrenia odorata and M. brachystephana present differences in the morphology and size of their corona, gynostegium and pollinaria, which explain the differences in details of the functioning of the general pollination mechanism. Pollination is performed by different groups of highly effective pollinators. Morrenia species are specialized for pollination mainly by several species of wasps, a specialized pollination which has been poorly studied. In particular, pompilid wasps are reported as important pollinators

  11. Inspiratory aerodynamic valving in the avian lung: functional morphology of the extrapulmonary primary bronchus.

    PubMed

    Maina, J N; Africa, M

    2000-09-01

    The form, geometry and epithelial morphology of the extrapulmonary primary bronchi (EPPB) of the domestic fowl (Gallus gallus var. domesticus) and the rock dove (Columba livia) were studied microscopically and by three-dimensional computer reconstruction to determine the structural features that may be involved in the rectification of the inspired air past the openings of the medioventral secondary bronchi (MVSB), i.e. the inspiratory aerodynamic valving (IAV). In both species, the EPPB were intercalated between the clavicular and the cranial thoracic air-sacs. A notable difference between the morphology of the EPPB in G. g. domesticus and C. livia was that, in the former, the EPPB were constricted at the origin of the MVSB, while a dilatation occurred at the same site in the latter. In both species, a highly vascularized, dorsally located hemispherical epithelial swelling was observed cranial to the origin of the MVSB. The MVSB were narrow at their origin and variably angled relative to the longitudinal axis of the EPPB. Conspicuous epithelial tracts and folds were observed on the luminal aspect of the EPPB in both C. livia and G. g. domesticus. From their marked development and their orientation relative to the angled MVSB, these properties may influence the flow of the air in the EPPB. It was concluded that features such as syringeal constriction, an intimate topographic relationship between the EPPB and the cranial air-sacs, prominent epithelial tracts and folds, an epithelial swelling ahead of the origin of the first MVSB (corresponding to the 'segmentun accelerans'), and narrowing and angulation of the MVSB at their origin, may together contribute to IAV to a variable extent. In as much as the mechanism of pulmonary ventilation and mode of airflow in the parabronchial lung are basically similar in all birds, the morphological differences observed between G. g. domesticus and C. livia suggest that either the mechanism of production of IAV or its functional

  12. Quantitative Trait Loci for Morphological Traits and their Association with Functional Genes in Raphanus sativus

    PubMed Central

    Yu, Xiaona; Choi, Su Ryun; Dhandapani, Vignesh; Rameneni, Jana Jeevan; Li, Xiaonan; Pang, Wenxing; Lee, Ji-Young; Lim, Yong Pyo

    2016-01-01

    Identification of quantitative trait loci (QTLs) governing morphologically important traits enables to comprehend their potential genetic mechanisms in the genetic breeding program. In this study, we used 210 F2 populations derived from a cross between two radish inbred lines (Raphanus sativus) “835” and “B2,” including 258 SSR markers were used to detect QTLs for 11 morphological traits that related to whole plant, leaf, and root yield in 3 years of replicated field test. Total 55 QTLs were detected which were distributed on each linkage group of the Raphanus genome. Individual QTLs accounted for 2.69–12.6 of the LOD value, and 0.82–16.25% of phenotypic variation. Several genomic regions have multiple traits that clustered together, suggested the existence of pleiotropy linkage. Synteny analysis of the QTL regions with A. thaliana genome selected orthologous genes in radish. InDels and SNPs in the parental lines were detected in those regions by Illumina genome sequence. Five identified candidate gene-based markers were validated by co-mapping with underlying QTLs affecting different traits. Semi-quantitative reverse transcriptase PCR analysis showed the different expression levels of these five genes in parental lines. In addition, comparative QTL analysis with B. rapa revealed six common QTL regions and four key major evolutionarily conserved crucifer blocks (J, U, R, and W) harboring QTL for morphological traits. The QTL positions identified in this study will provide a valuable resource for identifying more functional genes when whole radish genome sequence is released. Candidate genes identified in this study that co-localized in QTL regions are expected to facilitate in radish breeding programs. PMID:26973691

  13. ECM proteins in a microporous scaffold influence hepatocyte morphology, function, and gene expression.

    PubMed

    Wang, Yan; Kim, Myung Hee; Shirahama, Hitomi; Lee, Jae Ho; Ng, Soon Seng; Glenn, Jeffrey S; Cho, Nam-Joon

    2016-11-29

    It is well known that a three-dimensional (3D) culture environment and the presence of extracellular matrix (ECM) proteins facilitate hepatocyte viability and maintenance of the liver-specific phenotype in vitro. However, it is not clear whether specific ECM components such as collagen or fibronectin differentially regulate such processes, especially in 3D scaffolds. In this study, a series of ECM-functionalized inverted colloidal crystal (ICC) microporous scaffolds were fabricated and their influence on Huh-7.5 cell proliferation, morphology, hepatic-specific functions, and patterns of gene expression were compared. Both collagen and fibronectin promoted albumin production and liver-specific gene expression of Huh-7.5 cells, compared with the bare ICC scaffold. Interestingly, cells in the fibronectin-functionalized scaffold exhibited different aggregation patterns to those in the collagen-functionalized scaffold, a variation that could be related to the distinct mRNA expression levels of cell adhesion-related genes. Based on these results, we can conclude that different ECM proteins, such as fibronectin and collagen, indeed play distinct roles in the phenotypic regulation of cells cultured in a 3D environment.

  14. Facial bristle feather histology and morphology in New Zealand birds: implications for function.

    PubMed

    Cunningham, Susan J; Alley, Maurice R; Castro, Isabel

    2011-01-01

    Knowledge of structure in biology may help inform hypotheses about function. Little is known about the histological structure or the function of avian facial bristle feathers. Here we provide information on morphology and histology, with inferences for function, of bristles in five predominantly insectivorous birds from New Zealand. We chose species with differing ecologies, including: brown kiwi (Apteryx mantelli), morepork (Ninox novaezealandae), hihi (Notiomystis cincta), New Zealand robin (Petroica australis), and New Zealand fantail (Rhipidura fuliginosa). Average bristle length corrected for body size was similar across species. Bristles occurred in distinct groups on different parts of the head and upper rictal bristles were generally longest. The lower rictal bristles of the fantail were the longest possessed by that species and were long compared to bristles of other species. Kiwi were the only species with forehead bristles, similar in length to the upper rictal bristles of other species, and the lower rictal bristles of fantails. Herbst corpuscles (vibration and pressure sensitive mechanoreceptors) were found in association with bristle follicles in all species. Nocturnal and hole-nesting birds had more heavily encapsulated corpuscles than diurnal open-nesting species. Our results suggest that avian facial bristles generally have a tactile function in both nocturnal and diurnal species, perhaps playing a role in prey handling, gathering information during flight, navigating in nest cavities and on the ground at night and possibly in prey-detection. These differing roles may help explain the observed differences in capsule thickness of the corpuscles.

  15. Morphological and functional abnormalities in mitochondria associated with synaptic degeneration in prion disease.

    PubMed

    Sisková, Zuzana; Mahad, Don Joseph; Pudney, Carianne; Campbell, Graham; Cadogan, Mark; Asuni, Ayodeji; O'Connor, Vincent; Perry, Victor Hugh

    2010-09-01

    Synaptic and dendritic pathology is a well-documented component of prion disease. In common with other neurodegenerative diseases that contain an element of protein misfolding, little is known about the underlying mechanisms of synaptic degeneration. In particular, in prion disease the relationship between synaptic malfunction, degeneration, and mitochondria has been neglected. We investigated a wide range of mitochondrial parameters, including changes in mitochondrial density, inner membrane ultrastructure, functional properties and nature of mitochondrial DNA from hippocampal tissue of mice with prion disease, which have ongoing synaptic pathology. Our results indicate that despite a lack of detectable changes in either mitochondrial density or expression of the mitochondrial proteins, mitochondrial function was impaired when compared with age-matched control animals. We observed changes in mitochondrial inner membrane morphology and a reduction in the cytochrome c oxidase activity relative to a sustained level of mitochondrial proteins such as porin and individual, functionally important subunits of complex II and complex IV. These data support the idea that mitochondrial dysfunction appears to occur due to inhibition or modification of respiratory complex rather than deletions of mitochondrial DNA. Indeed, these changes were seen in the stratum radiatum where synaptic pathology is readily detected, indicating that mitochondrial function is impaired and could potentially contribute to or even initiate the synaptic pathology in prion disease.

  16. ECM proteins in a microporous scaffold influence hepatocyte morphology, function, and gene expression

    PubMed Central

    Wang, Yan; Kim, Myung Hee; Shirahama, Hitomi; Lee, Jae Ho; Ng, Soon Seng; Glenn, Jeffrey S.; Cho, Nam-Joon

    2016-01-01

    It is well known that a three-dimensional (3D) culture environment and the presence of extracellular matrix (ECM) proteins facilitate hepatocyte viability and maintenance of the liver-specific phenotype in vitro. However, it is not clear whether specific ECM components such as collagen or fibronectin differentially regulate such processes, especially in 3D scaffolds. In this study, a series of ECM-functionalized inverted colloidal crystal (ICC) microporous scaffolds were fabricated and their influence on Huh-7.5 cell proliferation, morphology, hepatic-specific functions, and patterns of gene expression were compared. Both collagen and fibronectin promoted albumin production and liver-specific gene expression of Huh-7.5 cells, compared with the bare ICC scaffold. Interestingly, cells in the fibronectin-functionalized scaffold exhibited different aggregation patterns to those in the collagen-functionalized scaffold, a variation that could be related to the distinct mRNA expression levels of cell adhesion-related genes. Based on these results, we can conclude that different ECM proteins, such as fibronectin and collagen, indeed play distinct roles in the phenotypic regulation of cells cultured in a 3D environment. PMID:27897167

  17. Application of morphological synthesis for understanding electrode microstructure evolution as a function of applied charge/discharge cycles

    NASA Astrophysics Data System (ADS)

    Glazoff, Michael V.; Dufek, Eric J.; Shalashnikov, Egor V.

    2016-10-01

    Morphological synthesis operations were employed for understanding electrode microstructure transformations and evolution accompanying the application of charge/discharge cycles to electrochemical storage systems (batteries). Using state-of-the-art morphological algorithms, it was possible to predict microstructure evolution in porous Si electrodes for Li-ion batteries with reasonable accuracy. The developed techniques could be considered supplementary to a phase-field mesoscopic approach to microstructure evolution that is based upon clear and definitive changes in the appearance of microstructure. However, unlike in phase field, the governing equations for the morphological approach are geometry, not physics, based. A similar non-physics-based approach to understanding different phenomena was attempted with the introduction of cellular automata. It is anticipated that morphological synthesis will represent a useful supplementary tool to phase field and will render assistance to unraveling the underlying microstructure-property relationships. The paper contains data on electrochemical characterization of different electrode materials that was conducted in parallel to the morphological study.

  18. Radon exposure mediated changes in lung macrophage morphology and function, in vitro

    SciTech Connect

    Seed, T.M.; Niiro, G.K.; Kretz, N.D.

    1990-01-01

    Bronchopulmonary macrophages play a key role in the normal physiology of the respiratory system. Potential respiratory dysfunctions due to radon/radon daughter exposure-mediated damage of the macrophage lung cell population has been explored via in vitro technology. In this study, macrophages were isolated from lungs of normal healthy dogs by saline lavage, cultured for varying periods (0-96 h) in the presence or absence of radon gas, and assessed for radon dose-dependent changes in cell morphology and function. The in vitro culture procedure and the cell exposing system allowed for detailed alpha particle dosimetry, in relation to the assessed biological end points; i.e. (1) exposure-dependent changes in macrophage surface topography, (2) capacity to elaborate specific growth factor (CSF) essential for self maintenance, and (3) alterations in cell viability. Highlights of the morphologic assessment indicate that relatively low alpha particle doses arising from protracted radon/radon daughter exposure elicites pronounced topographic alterations of the exposed macrophage's cell surface. 27 refs., 7 figs., 1 tab.

  19. Effects of Elevated β-Estradiol Levels on the Functional Morphology of the Testis - New Insights

    PubMed Central

    Leavy, Myles; Trottmann, Matthias; Liedl, Bernhard; Reese, Sven; Stief, Christian; Freitag, Benjamin; Baugh, John; Spagnoli, Giulio; Kölle, Sabine

    2017-01-01

    Elevated estradiol levels are correlated with male infertility. Causes of hyperestrogenism include diseases of the adrenal cortex, testis or medications affecting the hypothalamus-pituitary-gonadal axis. The aim of our study was to elucidate the effects of estradiol treatment on testicular cellular morphology and function, with reference to the treatment regimen received. Testes samples (n = 9) were obtained post-orchiectomy from male-to-female transsexuals within the age range of 26–52 years. Each patient had a minimum of 1–6 years estradiol treatment. For comparison, additional samples were obtained from microscopically unaltered testicular tissue surrounding tumors (n = 7). The tissues obtained were investigated by stereomicroscopy, histochemistry, scanning electron microscopy (SEM) and immunohistochemistry. Our studies revealed that estradiol treatment significantly decreased the diameter of the seminiferous tubules (p < 0.05) and induced fatty degeneration in the surrounding connective tissue. An increase in collagen fiber synthesis in the extracellular matrix (ECM) surrounding the seminiferous tubules was also induced. Spermatogenesis was impaired resulting in mainly spermatogonia being present. Sertoli cells revealed diminished expression of estrogen receptor alpha (ERα). Both Sertoli and Leydig cells showed morphological alterations and glycoprotein accumulations. These results demonstrate that increased estradiol levels drastically impact the human testis. PMID:28045098

  20. Morphological and Functional Features of Hepatic Cyst Epithelium in Autosomal Dominant Polycystic Kidney Disease

    PubMed Central

    Alvaro, Domenico; Onori, Paolo; Alpini, Gianfranco; Franchitto, Antonio; Jefferson, Douglas M.; Torrice, Alessia; Cardinale, Vincenzo; Stefanelli, Fabrizio; Mancino, Maria Grazia; Strazzabosco, Mario; Angelico, Mario; Attili, Adolfo; Gaudio, Eugenio

    2008-01-01

    We evaluated the morphological and functional features of hepatic cyst epithelium in adult autosomal dominant polycystic kidney disease (ADPKD). In six ADPKD patients, we investigated the morphology of cyst epithelium apical surface by scanning electron microscopy and the expression of estrogen receptors (ERs), insulin-like growth factor 1 (IGF1), IGF1 receptors (IGF1-R), growth hormone receptor, the proliferation marker proliferating cell nuclear antigen, and pAKT by immunohistochemistry and immunofluorescence. Proliferation of liver cyst-derived epithelial cells was evaluated by both MTS proliferation assay and [3H]thymidine incorporation into DNA. The hepatic cyst epithelium displayed heterogeneous features, being normal in small cysts (<1 cm), characterized by rare or shortened cilia in 1- to 3-cm cysts, and exhibiting the absence of both primary cilia and microvilli in large cysts (>3 cm). Cyst epithelium showed marked immunohistochemical expression of ER, growth hormone receptor, IGF1, IGF1-R, proliferating cell nuclear antigen, and pAKT. IGF1 was 10-fold more enriched in the hepatic cyst fluid than in serum. Serum-deprived liver cyst-derived epithelial cells proliferated when exposed to 17β-estradiol and IGF1 and when exposed to human cyst fluid. ER or IGF1-R antagonists inhibited the proliferative effect of serum readmission, cyst fluid, 17β-estradiol, and IGF1. Our findings could explain the role of estrogens in accelerating the progression of ADPKD and may suggest a potential benefit of therapeutic strategies based on estrogen antagonism. PMID:18202196

  1. Morphology, performance, fitness: functional insight into a post-Pleistocene radiation of mosquitofish.

    PubMed

    Langerhans, R Brian

    2009-08-23

    Bahamas mosquitofish (Gambusia hubbsi) colonized blue holes during the past approximately 15 000 years and exhibit relatively larger caudal regions in blue holes that contain piscivorous fish. It is hypothesized that larger caudal regions enhance fast-start escape performance and thus reflect an adaptation for avoiding predation. Here I test this hypothesis using a three-pronged, experimental approach. First, G. hubbsi from blue holes with predators were found to possess both greater fast-start performance and greater survivorship in the presence of predatory fish. Second, using individual-level data to investigate the morphology-performance-fitness pathway, I found that (i) fish with larger caudal regions produced higher fast-start performance and (ii) fish with higher fast-start performance enjoyed greater survivorship in the presence of fish predators-trends consistently observed across both predator regimes. Finally, I found that morphological divergence between predator regimes at least partially reflects genetic differentiation, as differences were retained in fish raised in a common laboratory environment. These results suggest that natural selection favours increased fast-start performance in the presence of piscivorous fish, consequently driving the evolution of larger caudal regions. Combined with previous work, this provides functional insight into body shape divergence and ecological speciation among Bahamian blue holes.

  2. Ovine Mesenchymal Stromal Cells: Morphologic, Phenotypic and Functional Characterization for Osteochondral Tissue Engineering

    PubMed Central

    Sanjurjo-Rodríguez, Clara; Castro-Viñuelas, Rocío; Hermida-Gómez, Tamara; Fernández-Vázquez, Tania; Fuentes-Boquete, Isaac Manuel; de Toro-Santos, Francisco Javier; Blanco-García, Francisco Javier

    2017-01-01

    Introduction Knowledge of ovine mesenchymal stromal cells (oMSCs) is currently expanding. Tissue engineering combining scaffolding with oMSCs provides promising therapies for the treatment of osteochondral diseases. Purpose The aim was to isolate and characterize oMSCs from bone marrow aspirates (oBMSCs) and to assess their usefulness for osteochondral repair using β-tricalcium phosphate (bTCP) and type I collagen (Col I) scaffolds. Methods Cells isolated from ovine bone marrow were characterized morphologically, phenotypically, and functionally. oBMSCs were cultured with osteogenic medium on bTCP and Col I scaffolds. The resulting constructs were evaluated by histology, immunohistochemistry and electron microscopy studies. Furthermore, oBMSCs were cultured on Col I scaffolds to develop an in vitro cartilage repair model that was assessed using a modified International Cartilage Research Society (ICRS) II scale. Results oBMSCs presented morphology, surface marker pattern and multipotent capacities similar to those of human BMSCs. oBMSCs seeded on Col I gave rise to osteogenic neotissue. Assessment by the modified ICRS II scale revealed that fibrocartilage/hyaline cartilage was obtained in the in vitro repair model. Conclusions The isolated ovine cells were demonstrated to be oBMSCs. oBMSCs cultured on Col I sponges successfully synthesized osteochondral tissue. The data suggest that oBMSCs have potential for use in preclinical models prior to human clinical studies. PMID:28141815

  3. Morphological and phase evolution of TiO 2 nanocrystals prepared from peroxotitanate complex aqueous solution: Influence of acetic acid

    NASA Astrophysics Data System (ADS)

    Chang, Jeong Ah; Vithal, Muga; Baek, In Chan; Seok, Sang Il

    2009-04-01

    Nanosized anatase and rutile TiO 2 having different shape, phase and size have been prepared from aqueous solutions of peroxo titanium complex starting from titanium(IV) isopropoxide (TTIP), acetic acid and hydrogen peroxide (H 2O 2) in water/isopropanol media by a facile sol-gel process. The TiO 2 nanocrystals are characterized by powder X-ray diffraction (XRD), Raman spectroscopy, FT-IR spectroscopy, TEM, high resolution transmission electron microscopy (HRTEM) and selected area electron diffraction (SAED) techniques. The influence of pH and the sequence of addition of reaction contents on the phase and morphology of TiO 2 are studied. The reasons for the observation of only anatase and/or mixture of anatase and rutile are given.

  4. Vestibular Function Research (VFR) experiment. Phase B: Design definition study

    NASA Technical Reports Server (NTRS)

    1978-01-01

    The Vestibular Functions Research (VFR) Experiment was established to investigate the neurosensory and related physiological processes believed to be associated with the space flight nausea syndrome and to develop logical means for its prediction, prevention and treatment. The VFR Project consists of ground and spaceflight experimentation using frogs as specimens. The phase B Preliminary Design Study provided for the preliminary design of the experiment hardware, preparation of performance and hardware specification and a Phase C/D development plan, establishment of STS (Space Transportation System) interfaces and mission operations, and the study of a variety of hardware, experiment and mission options. The study consist of three major tasks: (1) mission mode trade-off; (2) conceptual design; and (3) preliminary design.

  5. Lattice simulations of phase morphology on lipid bilayers: Renormalization, membrane shape, and electrostatic dipole interactions

    NASA Astrophysics Data System (ADS)

    Amazon, Jonathan J.; Feigenson, Gerald W.

    2014-02-01

    When liquid phases coexist at equilibrium but are not driven to minimize domain interfacial contact energy, the resulting patterns of phase domains can have important implications for living cells. In this study we explore some of the interactions and conditions that produce the stable patterned phases that are observed in model lipid mixtures. By use of Monte Carlo simulations we find that background curvature is important for the formation of patterned (modulated) phases. The interactions that stabilize nanoscopic phase separation are still not well understood. We show that inclusion of an electrostatic dipole repulsion with decay lengths as short as two to four lipid diameters can break up domains at the nanometer scale and that the location of the miscibility critical point is sensitive to this interaction. The use of a coarse-grained simulation raises questions about comparing parameters in simulations performed at different length scales. Using renormalization group techniques we show how to reconcile this problem, treating line tension as a running coupling constant.

  6. Morphological analysis of GeTe in inline phase change switches

    SciTech Connect

    King, Matthew R.; El-Hinnawy, Nabil; Salmon, Mike; Gu, Jitty; Wagner, Brian P.; Jones, Evan B.; Howell, Robert S.; Nichols, Doyle T.; Young, Robert M.; Borodulin, Pavel

    2015-09-07

    Crystallization and amorphization phenomena in indirectly heated phase change material-based devices were investigated. Scanning transmission electron microscopy was utilized to explore GeTe phase transition processes in the context of the unique inline phase change switch (IPCS) architecture. A monolithically integrated thin film heating element successfully converted GeTe to ON and OFF states. Device cycling prompted the formation of an active area which sustains the majority of structural changes during pulsing. A transition region on both sides of the active area consisting of polycrystalline GeTe and small nuclei (<15 nm) in an amorphous matrix was also observed. The switching mechanism, determined by variations in pulsing parameters, was shown to be predominantly growth-driven. A preliminary model for crystallization and amorphization in IPCS devices is presented.

  7. Morphological analysis of GeTe in inline phase change switches

    NASA Astrophysics Data System (ADS)

    King, Matthew R.; El-Hinnawy, Nabil; Salmon, Mike; Gu, Jitty; Wagner, Brian P.; Jones, Evan B.; Borodulin, Pavel; Howell, Robert S.; Nichols, Doyle T.; Young, Robert M.

    2015-09-01

    Crystallization and amorphization phenomena in indirectly heated phase change material-based devices were investigated. Scanning transmission electron microscopy was utilized to explore GeTe phase transition processes in the context of the unique inline phase change switch (IPCS) architecture. A monolithically integrated thin film heating element successfully converted GeTe to ON and OFF states. Device cycling prompted the formation of an active area which sustains the majority of structural changes during pulsing. A transition region on both sides of the active area consisting of polycrystalline GeTe and small nuclei (<15 nm) in an amorphous matrix was also observed. The switching mechanism, determined by variations in pulsing parameters, was shown to be predominantly growth-driven. A preliminary model for crystallization and amorphization in IPCS devices is presented.

  8. Cholesterol increase in mitochondria: its effect on inner-membrane functions, submitochondrial localization and ultrastructural morphology.

    PubMed Central

    Echegoyen, S; Oliva, E B; Sepulveda, J; Díaz-Zagoya, J C; Espinosa-García, M T; Pardo, J P; Martínez, F

    1993-01-01

    The effect of cholesterol incorporation on some functions of the mitochondrial inner membrane and on the morphology of rat liver mitochondria was studied. Basal ATPase and succinate dehydrogenase activities remained unchanged after cholesterol was incorporated into the mitochondria; however, uncoupled ATPase activity was partially inhibited. The presence of several substrates and inhibitors did not change the amount of cholesterol incorporated, which was localized mostly in the outer membrane. Electron-microscope observations revealed the presence of vesicles between the outer and inner membranes; these vesicles increased in number with the amount of cholesterol incorporated. The data suggest that cholesterol induces the formation of vesicles from the outer membrane, and modifies the activity of stimulated ATPase. Images Figure 4 PMID:8435069

  9. Functional morphology and biomechanics of branch-stem junctions in columnar cacti.

    PubMed

    Schwager, Hannes; Masselter, Tom; Speck, Thomas; Neinhuis, Christoph

    2013-12-07

    Branching in columnar cacti features morphological and anatomical characteristics specific to the subfamily Cactoideae. The most conspicuous features are the pronounced constrictions at the branch-stem junctions, which are also present in the lignified vascular structures within the succulent cortex. Based on finite-element analyses of ramification models, we demonstrate that these indentations in the region of high flexural and torsional stresses are not regions of structural weakness (e.g. allowing vegetative propagation). On the contrary, they can be regarded as anatomical adaptations to increase the stability by fine-tuning the stress state and stress directions in the junction along prevalent fibre directions. Biomimetic adaptations improving the functionality of ramifications in technical components, inspired, in particular, by the fine-tuned geometrical shape and arrangement of lignified strengthening tissues of biological role models, might contribute to the development of alternative concepts for branched fibre-reinforced composite structures within a limited design space.

  10. Functional morphology and biomechanics of branch–stem junctions in columnar cacti

    PubMed Central

    Schwager, Hannes; Masselter, Tom; Speck, Thomas; Neinhuis, Christoph

    2013-01-01

    Branching in columnar cacti features morphological and anatomical characteristics specific to the subfamily Cactoideae. The most conspicuous features are the pronounced constrictions at the branch–stem junctions, which are also present in the lignified vascular structures within the succulent cortex. Based on finite-element analyses of ramification models, we demonstrate that these indentations in the region of high flexural and torsional stresses are not regions of structural weakness (e.g. allowing vegetative propagation). On the contrary, they can be regarded as anatomical adaptations to increase the stability by fine-tuning the stress state and stress directions in the junction along prevalent fibre directions. Biomimetic adaptations improving the functionality of ramifications in technical components, inspired, in particular, by the fine-tuned geometrical shape and arrangement of lignified strengthening tissues of biological role models, might contribute to the development of alternative concepts for branched fibre-reinforced composite structures within a limited design space. PMID:24132310

  11. Citral exerts its antifungal activity against Penicillium digitatum by affecting the mitochondrial morphology and function.

    PubMed

    Zheng, Shiju; Jing, Guoxing; Wang, Xiao; Ouyang, Qiuli; Jia, Lei; Tao, Nengguo

    2015-07-01

    This work investigated the effect of citral on the mitochondrial morphology and function of Penicillium digitatum. Citral at concentrations of 2.0 or 4.0 μL/mL strongly damaged mitochondria of test pathogen by causing the loss of matrix and increase of irregular mitochondria. The deformation extent of the mitochondria of P. digitatum enhanced with increasing concentrations of citral, as evidenced by a decrease in intracellular ATP content and an increase in extracellular ATP content of P. digitatum cells. Oxygen consumption showed that citral resulted in an inhibition in the tricarboxylic acid cycle (TCA) pathway of P. digitatum cells, induced a decrease in activities of citrate synthetase, isocitrate dehydrogenase, α-ketoglutarate dehydrogenase, succinodehydrogenase and the content of citric acid, while enhancing the activity of malic dehydrogenase in P. digitatum cells. Our present results indicated that citral could damage the mitochondrial membrane permeability and disrupt the TCA pathway of P. digitatum.

  12. CRSBP-1/LYVE-1-null Mice Exhibit Identifiable Morphological and Functional Alterations of Lymphatic Capillary Vessels

    PubMed Central

    Huang, Shuan S.; Liu, I-Hua; Smith, Tracy; Shah, Maulik R.; Johnson, Frank E.; Huang, Jung S.

    2010-01-01

    CRSBP-1, a membrane glycoprotein, can mediate cell-surface retention of secreted growth factors containing CRS motifs such as PDGF-BB. CRSBP-1 has recently been found to be identical to LYVE-1, a specific marker for lymphatic capillary endothelial cells. The in vivo role of CRSBP-1/LYVE-1 is unknown. CRSBP-1-null mice are overtly normal and fertile but exhibit identifiable morphological and functional alterations of lymphatic capillary vessels in certain tissues, marked by the constitutively increased interstitial-lymphatic flow and lack of typical irregularly-shaped lumens. The CRSBP-1 ligands PDGF-BB and HA enhance interstitial-lymphatic flow in wild-type mice but not in CRSBP-1-null animals. PMID:17070806

  13. Effects of short chain fatty acids on gut morphology and function.

    PubMed Central

    Scheppach, W

    1994-01-01

    Short chain fatty acids (SCFAs) are the products of colonic bacterial degradation of unabsorbed starch and non-starch polysaccharide (fibre). They are important anions in the colonic lumen, affecting both colonocyte morphology and function. The three main acids (acetate, propionate, and butyrate) stimulate colonic sodium and fluid absorption and exert proliferative effects on the colonocyte. Experimental animal studies have shown that they promote adaptive responses to small intestinal resection and colonic anastomosis. Acetate increases colonic blood flow and enhances ileal motility. Butyrate has been shown to be the preferred energy substrate for the colonocyte and to be a potent differentiating agent in cell culture. Butyrate may also have a role in preventing certain types of colitis. A diet low in resistant starch and fibre, which will result in a low production of SCFAs in the colon, may explain the high occurrence of colonic disorders seen in the Western civilization. PMID:8125387

  14. Functional morphological imaging of autism spectrum disorders: current position and theories proposed.

    PubMed

    Lauvin, M-A; Martineau, J; Destrieux, C; Andersson, F; Bonnet-Brilhault, F; Gomot, M; El-Hage, W; Cottier, J-P

    2012-03-01

    Autism is a pervasive disorder of childhood development. Polymorphous clinical profiles combining various degrees of communication and social interaction with restricted and stereotyped behaviour are grouped under the heading of 'autism spectrum disorders' (ASD). Many teams are trying to pick out the underlying cerebral abnormalities in order to understand the neuronal networks involved in relationships with others. Here we review the morphological, spectroscopic and functional abnormalities in the amygdala-hippocampal circuit, the caudate nuclei, the cerebellum, and the frontotemporal regions, which have been described in subjects with ASD. White matter abnormalities have also been described in diffusion tensor imaging, leading to suspected damage to the subjacent neural networks, such as mirror neurones or the social brain.

  15. Functional morphology of suction discs and attachment performance of the Mediterranean medicinal leech (Hirudo verbana Carena)

    PubMed Central

    Eberhard, Laura; Gallenmüller, Friederike; Speck, Thomas

    2016-01-01

    Medicinal leeches use their suction discs for locomotion, adhesion to the host and, in the case of the anterior disc, also for blood ingestion. The biomechanics of their suction-based adhesion systems has been little understood until now. We investigated the functional morphology of the anterior and posterior suckers of Hirudo verbana by using light and scanning electron microscopy. Furthermore, we analysed the adhesion qualitatively and quantitatively by conducting behavioural and mechanical experiments. Our high-speed video analyses provide new insights into the attachment and detachment processes and we present a detailed description of the leech locomotion cycle. Pull-off force measurements of the anterior and posterior suction organs on seven different substrates under both aerial and water-submersed conditions reveal a significant influence of the surrounding medium, the substrate surface roughness and the tested organ on attachment forces and tenacities. PMID:27075001

  16. Trabecular bone recovers from mechanical unloading primarily by restoring its mechanical function rather than its morphology.

    PubMed

    Ozcivici, Engin; Judex, Stefan

    2014-10-01

    Upon returning to normal ambulatory activities, the recovery of trabecular bone lost during unloading is limited. Here, using a mouse population that displayed a large range of skeletal susceptibility to unloading and reambulation, we tested the impact of changes in trabecular bone morphology during unloading and reambulation on its simulated mechanical properties. Female adult mice from a double cross of BALB/cByJ and C3H/HeJ strains (n=352) underwent 3wk of hindlimb unloading followed by 3wk of reambulation. Normally ambulating mice served as controls (n=30). As quantified longitudinally by in vivo μCT, unloading led to an average loss of 43% of trabecular bone volume fraction (BV/TV) in the distal femur. Finite element models of the μCT tomographies showed that deterioration of the trabecular structure raised trabecular peak Von-Mises (PVM) stresses on average by 27%, indicating a significant increase in the risk of mechanical failure compared to baseline. Further, skewness of the Von-Mises stress distributions (SVM) increased by 104% with unloading, indicating that the trabecular structure became inefficient in resisting the applied load. During reambulation, bone of experimental mice recovered on average only 10% of its lost BV/TV. Even though the addition of trabecular tissue was small during reambulation, PVM and SVM as indicators of risk of mechanical failure decreased by 56% and 57%, respectively. Large individual differences in the response of trabecular bone, together with a large sample size, facilitated stratification of experimental mice based on the level of recovery. As a fraction of all mice, 66% of the population showed some degree of recovery in BV/TV while in 89% and 87% of all mice, PVM and SVM decreased during reambulation, respectively. At the end of the reambulation phase, only 8% of the population recovered half of the unloading induced losses in BV/TV while 50% and 49% of the population recovered half of the unloading induced

  17. Strehl ratio and modulation transfer function for segmented mirror telescopes as functions of segment phase error.

    PubMed

    Chanan, G; Troy, M

    1999-11-01

    We derive the Strehl ratio for a segmented mirror telescope as a function of the rms segment phase error and the observing wavelength, with and without the effects of the atmosphere. A simple analytical expression is given for the atmosphere-free case. Although our specific results are in the context of the Keck telescope, they are presented in a way that should be readily adaptable to other segmented geometries. We also derive the corresponding modulation transfer functions. These results are useful in determining how accurately a segmented mirror telescope needs to be phased for a variety of observing applications.

  18. Effect of phase morphologies on the mechanical properties of babbitt-bronze composite interfaces

    NASA Astrophysics Data System (ADS)

    Liaw, P. K.; Gungor, M. N.; Logsdon, W. A.; Ijiri, Y.; Taszarek, B. J.; Frohlich, S.

    1990-02-01

    Interfaces of two different babbitt-bronze composites were tested ultrasonically and then were fractured using the Chalmers test method. The primary distinction between the two composites was in the copper content. Use of less copper in the babbitt resulted in interfaces with higher strength, lower ductility, less cracking, and less unbonded area. The differences appeared to stem from the structure of the intermetallic compounds found at the interface, namely, the Cu3Sn and the Cu6Sn5 layers. The low-copper composite failed within a thick, dendrite-like Cu6Sn5 layer, while the high-copper one separated at the interface between a smooth Cu6Sn5 layer and the babbitt metal. The rough interface morphology seemed responsible for the low-copper composite’s increased strength. The correlation between mechanical and ultrasonic properties was poor for the low-copper composite but excellent for the high-copper one. These results suggest that interface morphology can significantly affect mechanical as well as ultrasonic properties.

  19. Quantifying morphological parameters of the terminal branching units in a mouse lung by phase contrast synchrotron radiation computed tomography.

    PubMed

    Hwang, Jeongeun; Kim, Miju; Kim, Seunghwan; Lee, Jinwon

    2013-01-01

    An effective technique of phase contrast synchrotron radiation computed tomography was established for the quantitative analysis of the microstructures in the respiratory zone of a mouse lung. Heitzman's method was adopted for the whole-lung sample preparation, and Canny's edge detector was used for locating the air-tissue boundaries. This technique revealed detailed morphology of the respiratory zone components, including terminal bronchioles and alveolar sacs, with sufficiently high resolution of 1.74 µm isotropic voxel size. The technique enabled visual inspection of the respiratory zone components and comprehension of their relative positions in three dimensions. To check the method's feasibility for quantitative imaging, morphological parameters such as diameter, surface area and volume were measured and analyzed for sixteen randomly selected terminal branching units, each consisting of a terminal bronchiole and a pair of succeeding alveolar sacs. The four types of asymmetry ratios concerning alveolar sac mouth diameter, alveolar sac surface area, and alveolar sac volume are measured. This is the first ever finding of the asymmetry ratio for the terminal bronchioles and alveolar sacs, and it is noteworthy that an appreciable degree of branching asymmetry was observed among the alveolar sacs at the terminal end of the airway tree, despite the number of samples was small yet. The series of efficient techniques developed and confirmed in this study, from sample preparation to quantification, is expected to contribute to a wider and exacter application of phase contrast synchrotron radiation computed tomography to a variety of studies.

  20. Functional morphology of the forelimb of living and extinct tree-kangaroos (Marsupialia: Macropodidae).

    PubMed

    Warburton, Natalie M; Harvey, Kathryn J; Prideaux, Gavin J; O'Shea, James E

    2011-10-01

    Tree-kangaroos are a unique group of arboreal marsupials that evolved from terrestrial ancestors. The recent discovery of well-preserved specimens of extinct tree-kangaroo species (genus Bohra) within Pleistocene cave deposits of south-central Australia provides a unique opportunity to examine adaptive evolution of tree-kangaroos. Here, we provide the first detailed description of the functional anatomy of the forelimb, a central component of the locomotor complex, in the extant Dendrolagus lumholtzi, and compare its structure and function with representatives of other extant marsupial families. Several features were interpreted as adaptations for coping with a discontinuous, uneven and three-dimensional arboreal substrate through enhanced muscular strength and dexterity for propulsion, grasping, and gripping with the forelimbs. The forelimb musculoskeletal anatomy of Dendrolagus differed from terrestrial kangaroos in the following principal ways: a stronger emphasis on the development of muscles groups responsible for adduction, grasping, and gripping; the enlargement of muscles that retract the humerus; and modified shape of the scapula and bony articulations of the forelimb bones to allow improved mobility. Many of these attributes are convergent with other arboreal marsupials. Tree-kangaroos, however, still retain the characteristic bauplan of their terrestrial ancestors, particularly with regard to skeletal morphology, and the muscular anatomy of the forelimb highlights a basic conservatism within the group. In many instances, the skeletal remains of Bohra have similar features to Dendrolagus that suggest adaptations to an arboreal habit. Despite the irony of their retrieval from deposits of the Nullarbor "Treeless" Plain, forelimb morphology clearly shows that the species of Bohra were well adapted to an arboreal habitat.

  1. ALAMEDA, a Structural–Functional Model for Faba Bean Crops: Morphological Parameterization and Verification

    PubMed Central

    RUIZ-RAMOS, MARGARITA; MÍNGUEZ, M. INÉS

    2006-01-01

    • Background Plant structural (i.e. architectural) models explicitly describe plant morphology by providing detailed descriptions of the display of leaf and stem surfaces within heterogeneous canopies and thus provide the opportunity for modelling the functioning of plant organs in their microenvironments. The outcome is a class of structural–functional crop models that combines advantages of current structural and process approaches to crop modelling. ALAMEDA is such a model. • Methods The formalism of Lindenmayer systems (L-systems) was chosen for the development of a structural model of the faba bean canopy, providing both numerical and dynamic graphical outputs. It was parameterized according to the results obtained through detailed morphological and phenological descriptions that capture the detailed geometry and topology of the crop. The analysis distinguishes between relationships of general application for all sowing dates and stem ranks and others valid only for all stems of a single crop cycle. • Results and Conclusions The results reveal that in faba bean, structural parameterization valid for the entire plant may be drawn from a single stem. ALAMEDA was formed by linking the structural model to the growth model ‘Simulation d'Allongement des Feuilles’ (SAF) with the ability to simulate approx. 3500 crop organs and components of a group of nine plants. Model performance was verified for organ length, plant height and leaf area. The L-system formalism was able to capture the complex architecture of canopy leaf area of this indeterminate crop and, with the growth relationships, generate a 3D dynamic crop simulation. Future development and improvement of the model are discussed. PMID:16390842

  2. Bioeffective Ultrasound at Very Low Doses: Reversible Manipulation of Neuronal Cell Morphology and Function in Vitro

    NASA Astrophysics Data System (ADS)

    Muratore, Robert; LaManna, Justine; Szulman, Erin; Kalisz, M. S. Andrew; Lamprecht, Michael; Simon, M. S. Melissa; Yu, M. S. Zhe; Xu, Nina; Morrison, Barclay

    2009-04-01

    Direct and safe manipulation of neurons by external means is an increasingly studied therapeutic modality with the potential to treat many neurological diseases. Anticipating such future applications, we investigated reversible bioeffects of very low dose focused ultrasound on neuronal cell morphology and function in vitro. To test morphological changes, undifferentiated PC12 cells were serum-cultured. The culture plates were placed on an inverted optical microscope. An f/1.1 ultrasound transducer with a water-filled coupling cone was focused on the culture and excited with 30-ms 4.67-MHz 100-kPa pulses. To test functional changes, rat hippocampal slices were cultured and individually transferred to the well of a 60-channel multi electrode array. An f/2.1 ultrasound transducer with a water-filled coupling cone was focused on a culture and excited with 100-μs 4.04-MHz 77-kPa pulses. The culture was stimulated before and after the ultrasonic stimulus with a 100-μs 100-μA biphasic electrical stimulus. Optical microscopy of PC12 cultures under insonification revealed that cells that were clustered near the ultrasound focal region elongated by approximately 2 μm during insonification and returned to approximately their original shapes following insonification. We conclude that the acoustic radiation force is capable of reversibly deforming cultured cells. In the rat hippocampal cultures, the ultrasonically and electrically evoked responses exhibited similar biphasic waveforms. In addition, robust electrically evoked responses following insonification indicated that the insonified cultures remained viable. We conclude that low-dose ultrasound can stimulate neurons; the mechanism is currently under investigation.

  3. The thoracic limb of the suricate (Suricata suricatta): osteology, radiologic anatomy, and functional morphologic changes.

    PubMed

    van Staden, Sheryl L

    2014-09-01

    The purpose of the study was to identify unique features of the normal osteology and radiologic anatomy of the thoracic limb of the meerkat or suricate (Suricata suricatta), as no comprehensive information has been published. Bone specimens of 19 suricates were studied. Individual bones of the manus of one preserved carcass were studied in situ. Radiographic evaluation was performed in six animals. Comparisons to domestic carnivores were made and functional morphologic changes were identified. A suprahamate process was present on the scapula spine. Both supratrochlear and supracondylar foramina were present in the distal humerus, with a small Fossa coronoidea seen cranially. The medial epicondyle was markedly larger than the lateral epicondyle. The Tuberositas radii was located caudally. The proximal end of the olecranon was prominent medially. The large medial coronoid process had an extensive proximal articulation facet for the humeral trochlea. The ulna styloid process articulated with the ulnar and accessory carpal bones. The manus was similar to that of domestic carnivores; however, Os metacarpalis I was markedly reduced with the absence of the first digit. There were seven carpal bones. Os carpi radiale was the largest, with a large palmaro-medial process and a small sesamoid bone present medially. Ossa metacarpalia II-V and corresponding phalanges were slender, with an elongated Processus unguicularis (third phalanx) present. Radiologic findings demonstrated increased mobility of the scapula and shoulder joint, with ease of abduction. On the cranio-caudal view of the humerus and elbow joint, the distal radius and manus were consistently rotated in a supinated position. Morphologic changes were identified for the enhanced, predominant function of the shoulder, elbow, carpal, and digital flexor muscles associated with superior digging ability, and supination of the antebrachium and manus. Reference values for size parameters of the long bones are reported. The

  4. Study on phase function in Monte Carlo transmission characteristics of poly-disperse aerosol

    NASA Astrophysics Data System (ADS)

    Bai, Lu; Wu, Zhen-Sen; Tang, Shuang-Qing; Li, Ming; Xie, Pin-Hua; Wang, Shi-Mei

    2011-01-01

    Henyey-Greenstein (H-G) phase function is typically used as an approximation to Mie phase function and its shortcomings have been discussed in numerous papers. But the judicious criterion of when the H-G phase function would be valid is still ambiguous. In this paper, we use the direct sample phase function method in transmittance calculation. A comparison of the direct sample phase function method and the H-G phase function is presented. The percentage of the multiple scattering in Monte Carlo transfer computations is discussed. Numerical results showed that using H-G phase function led to underestimating the transmittance. The deflection of root means square error can be used as a criterion. Although the exact calculation of sample phase function requires slightly more computation time, the rigorous phase function simulation method has an important role in the Monte Carlo radiative transfer computation problems.

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

    PubMed Central

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

    2016-01-01

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

  6. Morphology of Poly(3,4-ethylene dioxythiophene) (PEDOT) Thin Films, Crystals, Cubic Phases, Fibers and Tubes

    NASA Astrophysics Data System (ADS)

    Wu, Jinghang

    Poly(3,4-ethylene dioxythiophene) (PEDOT) is a chemically stable, conjugated polymer that is of considerable interest for a variety of organic electronic devices including microfabricated neural electrodes that interface with living cortical tissue. The properties of conducting polymers are strongly dependent on the morphology and structure of the material in the solid-state. The rigid pi-pi conjugated conformation of PEDOT facilitates charge transport and favors crystallization that reduces solubility and processability, making detailed studies of PEDOT morphology difficult. This has also made it hard to control the microstructure at a variety of length scales. In this dissertation the morphology of PEDOT has been studied and controlled at several different length scales from manometers to micrometers. On the nanoscale, the primary intermolecular (100) d-spacing in PEDOT crystals has been controlled from 1.15 nm to 1.52 nm by using different counter-ions as dopants. The surface morphology and crystallinity of electrochemically deposited PEDOT films have been controlled by changing deposition conditions. A highly ordered, crystalline PEDOT-Br phase was formed during electrochemical deposition in the presence of bromine counterions. On the tens of nanometers scale, isotropic PEDOT bicontinuous cubic structures with extremely large surface areas were developed using ternary non-ionic surfactant, water and oil systems. On the micrometer scale, aligned PEDOT fibers and tubes were prepared by electrospinning blends of poly(lactide-co-glycolide) (PLGA) or poly(caprolactone) (PCL) and EDOT monomer onto a rotating wheel or a dielectric gap in a metal substrate. These aligned fibers and tubes were shown to precisely direct neural regeneration in specific directions in vitro. These developments help understand the structure and properties of conjugated polymers for use in organic electronic devices.

  7. Left ventricular morphology and function in mild to moderate essential hypertension.

    PubMed

    Niederle, P; Rakická, E; Koudelková, E; Hejl, Z; Gebauerová, M; Widimský, J

    1984-01-01

    150 males with mild to moderate essential hypertension [EH] were examined echocardiographically and the findings in the left ventricle [LV] were compared with those in 20 normotensive men. Increased LV wall thickness and LV mass was found in 81% and 67% of hypertensives respectively in contrast with a complete absence of LV hypertrophy in normotensives. The former showed also a tendency to the concentric type hypertrophy, which can be considered a characteristic feature of the 2nd stage [WHO] EH. There was an almost uniform incidence of asymmetric septal hypertrophy in the two groups [12 vs. 10%]. Decreased LV end-systolic wall stress in EH was a sign of compensatory myocardial hypertrophy without LV dilatation. The hypertensives exhibited a normal or slightly elevated systolic LV function. On the other hand, some indirect indices of LV properties [peak rate of LV relaxation and left atrial dimension] were indicative of diastolic function impairment. A slight but significant correlation between the degree of LV hypertrophy and systemic blood pressure at rest was found in a part of hypertensive patients. The study indicates that mild to moderate EH leads to some changes in LV morphology and function, which can be easily recognized by echocardiography.

  8. The CALIFA and HIPASS Circular Velocity Function for All Morphological Galaxy Types

    NASA Astrophysics Data System (ADS)

    Bekeraitė, S.; Walcher, C. J.; Wisotzki, L.; Croton, D. J.; Falcón-Barroso, J.; Lyubenova, M.; Obreschkow, D.; Sánchez, S. F.; Spekkens, K.; Torrey, P.; van de Ven, G.; Zwaan, M. A.; Ascasibar, Y.; Bland-Hawthorn, J.; González Delgado, R.; Husemann, B.; Marino, R. A.; Vogelsberger, M.; Ziegler, B.

    2016-08-01

    The velocity function (VF) is a fundamental observable statistic of the galaxy population that is similar to the luminosity function in importance, but much more difficult to measure. In this work we present the first directly measured circular VF that is representative between 60 \\lt {v}{circ} \\lt 320 km s-1 for galaxies of all morphological types at a given rotation velocity. For the low-mass galaxy population (60 \\lt {v}{circ} \\lt 170 km s-1), we use the HI Parkes All Sky Survey VF. For the massive galaxy population (170 \\lt {v}{circ} \\lt 320 km s-1), we use stellar circular velocities from the Calar Alto Legacy Integral Field Area Survey (CALIFA). In earlier work we obtained the measurements of circular velocity at the 80% light radius for 226 galaxies and demonstrated that the CALIFA sample can produce volume-corrected galaxy distribution functions. The CALIFA VF includes homogeneous velocity measurements of both late and early-type rotation-supported galaxies and has the crucial advantage of not missing gas-poor massive ellipticals that HI surveys are blind to. We show that both VFs can be combined in a seamless manner, as their ranges of validity overlap. The resulting observed VF is compared to VFs derived from cosmological simulations of the z = 0 galaxy population. We find that dark-matter-only simulations show a strong mismatch with the observed VF. Hydrodynamic simulations fare better, but still do not fully reproduce observations.

  9. Hidden surface microstructures on Carboniferous insect Brodioptera sinensis (Megasecoptera) enlighten functional morphology and sensorial perception

    PubMed Central

    Prokop, Jakub; Pecharová, Martina; Ren, Dong

    2016-01-01

    Megasecoptera are insects with haustellate mouthparts and petiolate wings closely related to Palaeodictyoptera and one of the few insect groups that didn’t survive the Permian-Triassic mass extinction. Recent discovery of Brodioptera sinensis in early Pennsylvanian deposits at Xiaheyan in northern China has increased our knowledge of its external morphology using conventional optical stereomicroscopy. Environmental scanning electron microscopy (ESEM) of structures, such as antennae, mouthparts, wing surfaces, external copulatory organs and cerci have shed light on their micromorphology and supposed function. A comparative study has shown an unexpected dense pattern of setae on the wing membrane of B. sinensis. In addition, unlike the results obtained by stereomicroscopy it revealed that the male and female external genitalia clearly differ in their fine structure and setation. Therefore, the present study resulted in a closer examination of the microstructure and function of previously poorly studied parts of the body of Paleozoic insects and a comparison with homologous structures occurring in other Palaeodictyopteroida, Odonatoptera and Ephemerida. This indicates, that the role and presumptive function of these integumental protuberances is likely to have been a sensory one in the coordination of mouthparts and manipulation of stylets, escape from predators, enhancement of aerodynamic properties and copulatory behaviour. PMID:27321551

  10. Developmental integration in a functional unit: deciphering processes from adult dental morphology.

    PubMed

    Labonne, Gaëlle; Navarro, Nicolas; Laffont, Rémi; Chateau-Smith, Carmela; Montuire, Sophie

    2014-01-01

    The evolution of mammalian dentition is constrained by functional necessity and by the non-independence of morphological structures. Efficient chewing implies coherent tooth coordination from development to motion, involving covariation patterns (integration) within dental parts. Using geometric morphometrics, we investigate the modular organization of the highly derived vole dentition. Integration patterns between and within the upper and lower molar rows are analyzed to identify potential modules and their origins (functional and developmental). Results support an integrated adult dentition pattern for both developmental and functional aspects. The integration patterns between opposing molar pairs suggest a transient role for the second upper and lower molars during the chewing motion. Upper and lower molar rows form coherent units but the relative integration of molar pairs is in contradiction with existing developmental models. Emphasis on the first three cusps to grow leads to a very different integration pattern, which would be congruent with developmental models. The early developmental architecture of traits is masked by later stages of growth, but may still be deciphered from the adult phenotype, if careful attention is paid to relevant features.

  11. X-ray luminosity functions of different morphological and X-ray type AGN populations

    NASA Astrophysics Data System (ADS)

    Pović, M.; Pérez García, A. M.; Sánchez-Portal, M.; Bongiovanni, A.; Cepa, J.; Fernández Lorenzo, M.; Lara-López, M. A.; Gallego, J.; Ederoclite, A.; Márquez, I.; Masegosa, J.; Alfaro, E.; Castañeda, H.; González-Serrano, J. I.; González, J. J.

    2013-03-01

    Luminosity functions are one of the most important observational clues when studying galaxy evolution over cosmic time. In this paper we present the X-ray luminosity functions for X-ray detected AGN in the SXDS and GWS fields. The limiting fluxes of our samples are 9.0 ×10-15 and 4.8 ×10-16 erg cm-2 s-1 in the 0.5-7.0 keV band in the two fields, respectively. We carried out analysis in three X-ray bands and in two redshift intervals up to z≤1.4. Moreover, we derive the luminosity functions for different optical morphologies and X-ray types. We confirm strong luminosity evolution in all three bands, finding the most luminous objects at higher redshift. However, no signs of density evolution are found in any tested X-ray band. We obtain similar results for compact and early-type objects. Finally, we observe the ``Steffen effect'', where X-ray type-1 sources are more numerous at higher luminosities in comparison with type-2 sources.

  12. Morphology Mapping of Phase-Separated Polymer Films Using Nanothermal Analysis

    SciTech Connect

    Nikiforov, Maxim; Gam, Sangah; Jesse, Stephen; Composto, Russel C; Kalinin, Sergei V

    2010-01-01

    Polymers films are attractive, in part, because their physical properties can be tuned by blending polymer with complementary characteristics. However, blending is typically challenging because most polymers will undergo phase separation, resulting in unpredictable behavior. Here, we introduce band excitation nanothermal analysis (BE-NanoTA) as a nondestructive AFM-based technique for mapping the near surface, thermal properties of polymeric coatings. BE-NanoTA was used to investigate phase separation and domain growth in poly(styrene-ran-acrylonitrile):poly(methyl methacrylate) SAN:PMMA films. The size and shape of PMMA-rich domains are consistent with prior measurements on the same system using a destructive method, namely UV-ozone etching of PMMA followed by topography mapping using standard AFM. Moreover, new insights into the mechanism of phase separation were uncovered including the observation of SAN- and PMMA-rich channels near the surface at early times as well as small SAN-rich domains trapped within large PMMA domains during intermediate times. Because it is nondestructive, BE-NanoTA can be used to explore in situ phase evolution in soft matter systems (e.g., polymer nanocomposites) which do not lend themselves to the UV-ozone etching method

  13. Morphology evolution of gold nanoparticles as function of time, temperature, and Au(III)/sodium ascorbate molar ratio

    NASA Astrophysics Data System (ADS)

    Priolisi, Ornella; Fabrizi, Alberto; Deon, Giovanna; Bonollo, Franco; Cattini, Stefano

    2016-01-01

    In this work the morphology evolution of Au nanoparticles (AuNPs), obtained by direct reduction, was studied as a function of time, temperature, and Au(III)/sodium ascorbate molar ratio. The NPs morphology was examined by transmission electron microscope with image analysis, while time evolution was investigated by visible and near-infrared absorption spectroscopy and dynamic light scattering. It is found that initially formed star-like NPs transform in more spheroidal particles and the evolution appears more rapid by increasing the temperature while a large amount of reducing agent prevents the remodeling of AuNPs. An explication of morphology evolution is proposed.

  14. Taxonomic attribution of the Olduvai hominid 7 manual remains and the functional interpretation of hand morphology in robust australopithecines.

    PubMed

    Moyà-Solà, Salvador; Kohler, Meike; Alba, David M; Almécija, Sergio

    2008-01-01

    In this paper, we test the currently accepted taxonomic hypothesis that the hand of the Homo habilis holotype Olduvai hominid 7 (OH7) from Olduvai Gorge can be unambiguously assigned to Homo. Morphometric and morphological comparison with humans and australopithecines (Australopithecus and Paranthropus) indicate that the OH7 hand most likely belongs to P. boisei. The morphological adaptations of Paranthropus are thus further evaluated in the light of the alternative taxonomic hypothesis for OH7. Functional analyses suggest that morphological features related to human-like precision grasping, previously considered diagnostic of toolmaking by some, may be alternatively attributed to specialized manual feeding techniques in robust australopithecines.

  15. Effect of the duration of bladder overdistention on renal function and morphology in rats.

    PubMed

    Meng, Hong-Zhou; Cao, Min; Xiang, Jian-Jian; Zhou, Xie-Lai; Yin, Hong-Ping; Jin, Bai-Ye; Chen, Zhao-Dian; Jin, Xiao-Dong

    2013-06-01

    The aim of this study was to investigate the influence of the duration of bladder overdistention (DOBO) on kidney structure and function in rats. Bladder overdistention was induced in male Sprague-Dawley rats by an infusion of saline. Forty rats were divided into five groups: DOBO 1, 2, 4 or 8 h groups and the control. Renal function was evaluated using serum creatinine (SCr) and blood urea nitrogen (BUN). Apoptotic indices and morphologic changes of the kidney were detected by terminal deoxynucleotidyl transferase-mediated dUTP nick end labelling (TUNEL) staining and transmission electron microscopy (TEM). Compared with the control, rats undergoing 2, 4 or 8 h of overdistention showed significant, time-dependent increases in SCr (12.375 vs. 23.125, 34.375 and 51.500 μmol/l, respectively), BUN (6.980 vs. 18.689, 25.184 and 32.079 mmol/l, respectively), renal size (1.041 vs. 1.472, 1.484 and 1.634 cm(3), respectively) and renal pelvis separation (0.000 vs. 0.223, 0.320, 0.308 and 0.277 cm, respectively; P<0.01). In the rats, 2, 4 and 8 h of overdistention elicited time-dependent increases in the blood flow rate in the main renal artery (MRA; 44.827 vs. 49.082, 59.688 and 67.123 cm(3)/sec, control vs. DOBO 2, 4 and 8 h), the interlobar renal artery (IRA; 32.095 vs. 39.16 and 51.745 cm(3)/sec, control vs. DOBO 4 and 8 h) and the segmental renal artery (SRA; 21.171 vs. 24.355 and 25.358 cm(3)/sec, control vs. DOBO 4 and 8 h; P<0.01). TUNEL results showed that prolonged overdistention increased the apoptotic index of renal cells significantly (1.15, 1.77, 3.40, 5.34 and 13.91% for control and DOBO 1, 2, 4 and 8 h, respectively; P<0.01) and TEM indicated that prolonged overdistention resulted in ultrastructural injuries of increased severity. DOBO plays a significant role in the functional and structural impairment of the rat kidney. With increasing duration, the hemodynamic changes, cell apoptosis and ultrastructural injuries of the kidney are more evident, all of

  16. Of mice, moles and guinea pigs: functional morphology of the middle ear in living mammals.

    PubMed

    Mason, Matthew J

    2013-07-01

    The middle ear apparatus varies considerably among living mammals. Body size, phylogeny and acoustic environment all play roles in shaping ear structure and function, but experimental studies aimed ultimately at improving our understanding of human hearing can sometimes overlook these important species differences. This review focuses on three groups of mammals, bringing together anatomical, zoological and physiological information in order to highlight unusual features of their middle ears and attempt to interpret their function. "Microtype" ears, found in species such as mice and bats, are associated with high-frequency hearing. The orbicular apophysis, the focus of some recent developmental studies on mouse ears, is characteristic of microtype mallei but is not found in humans or other "freely mobile" species. The apophysis increases ossicular inertia about the anatomical axis of rotation: its adaptive purpose in a high-frequency ear is still not clear. Subterranean mammals have convergently evolved a "freely mobile" ossicular morphology which appears to favour lower-frequency sound transmission. More unusual features found in some of these animals include acoustically coupled middle ear cavities, the loss of middle ear muscles and hypertrophied ossicles which are believed to subserve a form of inertial bone conduction. Middle ears of the rodent group Ctenohystrica (which includes guinea pigs and chinchillas, important models in hearing research) show some striking characteristics which together comprise a unique type of auditory apparatus requiring a classification of its own, referred to here as the "Ctenohystrica type". These characteristics include a distinctive malleus morphology, fusion of the malleus and incus, reduction or loss of the stapedius muscle, a synovial stapedio-vestibular articulation and, in chinchillas, enormously expanded middle ear cavities. These characteristics may be functionally linked and associated with the excellent low

  17. The Relationship between Perisylvian Morphology and Verbal Short-Term Memory Functioning in Children with Neurodevelopmental Disorders

    ERIC Educational Resources Information Center

    Kibby, Michelle Y.; Kroese, Judith M.; Morgan, Allison E.; Hiemenz, Jennifer R.; Cohen, Morris J.; Hynd, George W.

    2004-01-01

    Although children with neurodevelopmental disorders frequently present with reduced short-term memory functioning, the relationship between perisylvian morphology and verbal short-term memory functioning has received limited attention. Thus, examining this relationship in children with neurodevelopmental disorders was the focus of this exploratory…

  18. Depth-related trends in morphological and functional diversity of demersal fish assemblages in the western Mediterranean Sea

    NASA Astrophysics Data System (ADS)

    Farré, Marc; Tuset, Víctor M.; Cartes, Joan E.; Massutí, Enric; Lombarte, Antoni

    2016-09-01

    The morphological and functional traits of fishes are key factors defining the ecological and biological habits of species within ecosystems. However, little is known about how the depth gradient affects these factors. In the present study, several demersal fish assemblages from the Balearic Islands (western Mediterranean Sea) along a wide depth range (40-2200 m) were morphologically, functionally and ecologically described. The morphological characterization of communities was performed using geometric morphometric methods, while the functional structures were obtained by the functional categorization of species and the application of principal coordinates analysis (PCoA). The results revealed that morphospaces presented less richness of body forms as depth increases, although they showed a progressive spreading of species toward the periphery, with a proliferation of more extreme body traits, demonstrating lower morphological redundancy. In addition, a trend toward the elongation of body shape was also observed with depth. Moreover, functional diversity increased with bathymetry up to 1400 m, where it sharply decreased downwards. This decrease was parallel to a progressive fall of H‧ (ecological diversity) up to 2200 m. Functional redundancy progressively decreased until the deepest assemblage (more constantly in the deeper levels), which was almost exclusively dominated by benthopelagic wandering species feeding on suprabenthos. Redundancy analysis (RDA) demonstrated that both morphological and functional spaces showed high variation along the bathymetric range. Mantel test indicated that the majority of species presented similar spatial distribution within the morphospace and functional space, although in the functional space the more abundant species were always located at the periphery. These results demonstrate that the assessment of the morpho-functional variation between marine communities helps to understand the processes that affect the structure and

  19. Generalised partition functions: inferences on phase space distributions

    NASA Astrophysics Data System (ADS)

    Treumann, Rudolf A.; Baumjohann, Wolfgang

    2016-06-01

    It is demonstrated that the statistical mechanical partition function can be used to construct various different forms of phase space distributions. This indicates that its structure is not restricted to the Gibbs-Boltzmann factor prescription which is based on counting statistics. With the widely used replacement of the Boltzmann factor by a generalised Lorentzian (also known as the q-deformed exponential function, where κ = 1/|q - 1|, with κ, q ∈ R) both the kappa-Bose and kappa-Fermi partition functions are obtained in quite a straightforward way, from which the conventional Bose and Fermi distributions follow for κ → ∞. For κ ≠ ∞ these are subject to the restrictions that they can be used only at temperatures far from zero. They thus, as shown earlier, have little value for quantum physics. This is reasonable, because physical κ systems imply strong correlations which are absent at zero temperature where apart from stochastics all dynamical interactions are frozen. In the classical large temperature limit one obtains physically reasonable κ distributions which depend on energy respectively momentum as well as on chemical potential. Looking for other functional dependencies, we examine Bessel functions whether they can be used for obtaining valid distributions. Again and for the same reason, no Fermi and Bose distributions exist in the low temperature limit. However, a classical Bessel-Boltzmann distribution can be constructed which is a Bessel-modified Lorentzian distribution. Whether it makes any physical sense remains an open question. This is not investigated here. The choice of Bessel functions is motivated solely by their convergence properties and not by reference to any physical demands. This result suggests that the Gibbs-Boltzmann partition function is fundamental not only to Gibbs-Boltzmann but also to a large class of generalised Lorentzian distributions as well as to the corresponding nonextensive statistical mechanics.

  20. Density functional theory study of phase IV of solid hydrogen

    NASA Astrophysics Data System (ADS)

    Pickard, Chris J.; Martinez-Canales, Miguel; Needs, Richard J.

    2012-06-01

    We have studied solid hydrogen up to pressures of 300 GPa and temperatures of 350 K using density functional theory methods and have found “mixed structures” that are more stable than those predicted earlier. Mixed structures consist of alternate layers of strongly bonded molecules and weakly bonded graphene-like sheets. Quasiharmonic vibrational calculations show that mixed structures are the most stable at room temperature over the pressure range 250-295 GPa. These structures are stabilized with respect to strongly bonded molecular phases at room temperature by the presence of lower frequency vibrational modes arising from the graphene-like sheets. Our results for the mixed structures are consistent with the experimental Raman data [M. I. Eremets and I. A. Troyan, Nat. Mater.1476-112210.1038/nmat3175 10, 927 (2011) and R. T. Howie , Phys. Rev. Lett.PRLTAO0031-900710.1103/PhysRevLett.108.125501 108, 125501 (2012)]. We find that mixed phases are reasonable structural models for phase IV of hydrogen.

  1. Phase matching considerations in second harmonic generation from tissues: Effects on emission directionality, conversion efficiency and observed morphology

    NASA Astrophysics Data System (ADS)

    LaComb, Ronald; Nadiarnykh, Oleg; Townsend, Sallie S.; Campagnola, Paul J.

    2008-04-01

    We present a heuristic treatment which relates SHG image intensities, signal directionality, and observed morphology to the physical structure of collagen and cellulose fibrillar tissues. The SHG creation model is based upon relaxed phase matching conditions which account for dispersion, randomness, and axial momentum contributions from the media, and includes a mathematical treatment which relates SHG conversion efficiency to fibril diameter and packing through the inclusion of potential intensity amplification resultant from quasi-phase matching (QPM). A direct consequence of this theory is that SHG in biological tissues is not strictly a coherent process, and that the forward directed SHG has a longer coherence length than the backward component, Through this treatment, we show that the emission directionality and also conversion efficiency do not arise solely from the fibril size but also depend on packing density and order of the inter-fibril structure. We demonstrate these principles in comparing the SHG response in normal and Osteogenesis Imperfecta (OI) skin. We show that the observed directionality and decreased relative intensity in the diseased state is consistent with phase matching conditions arising from the decreased fibril size and more random assembly. We further use this theory to explain the differences in morphology seen in forward and backward collected SHG in fibrillar tissues (e.g., collagenous and cellulosic). Specifically, we attribute segmented appearance to destructive interference between small fibrils separated by less than the coherence length. We suggest the approach based on relaxed phasematching conditions is general in predicting the SHG response in tissues and may be broadly applicable in interpreting the SHG contrast for diagnostic applications.

  2. Fabrication of structured porous films by breath figures and phase separation processes: tuning the chemistry and morphology inside the pores using click chemistry.

    PubMed

    S de León, Alberto; Del Campo, Adolfo; Fernández-García, Marta; Rodríguez-Hernández, Juan; Muñoz-Bonilla, Alexandra

    2013-05-01

    Herein, a facile water-assisted templating technique, the so-called breath figures method, in combination with phase separation process, was employed to prepare multifunctional micropatterned films. Tetrahydrofuran solutions of incompatible ternary blends consisting of high-molecular-weight polystyrene, an amphiphilic block copolymer, polystyrene-b-poly[poly(ethylene glycol) methyl ether methacrylate] (PS40-b-P(PEGMA300)48), and a fluorinated homopolymer, poly(2,3,4,5,6-pentafluorostyrene) (P5FS21) were casted under humid atmosphere varying the proportion of the components. Two simultaneously occurring processes, i.e., the breath figures mechanism and the phase separation process, lead to unprecedented morphologies that could be tuned by simply varying the relative humidity or the composition of the blend. Confocal micro-Raman spectroscopy served to provide information about the location and distribution of the different functionalities in the films. As a result, both the amphiphilic block copolymer and the fluorinated polymer were mainly located in the cavities. Above a certain percentage of relative humidity, honeycomb structured films were obtained in which the block copolymer is distributed on the edge of the pore as a result of the affinity by the condensing water droplet and the coffee stain effect. The homopolymer is also preferentially situated at the pore edge, but forming spherical domains with narrow polydisperse sizes. Moreover, thiolated glucose molecules were specifically attached to the P5FS21 domains via thiol-para fluorine "click" reaction. Subsequently, the specific lectin (Concanavalin A, Canavalia ensiformis) was attached to the surface by conjugation with the glucose moieties. The successful binding of the Con A was demonstrated by the fluorescence, observed exclusively at the areas where P5FS21 domains are located. This nonlithographic method opens a new route to fabricate a huge variety of microstructured polymer films in terms of morphology

  3. Structural, morphological, magnetic and dielectric characterization of nano-phased antimony doped manganese zinc ferrites

    NASA Astrophysics Data System (ADS)

    Sridhar, Ch. S. L. N.; Lakshmi, Ch. S.; Govindraj, G.; Bangarraju, S.; Satyanarayana, L.; Potukuchi, D. M.

    2016-05-01

    Nano-phased doped Mn-Zn ferrites, viz., Mn0.5-x/2Zn0.5-x/2SbXFe2O4 for x=0 to 0.3 (in steps of 0.05) prepared by hydrothermal method are characterized by X-ray diffraction, Infrared and scanning electron microscopy. XRD and SEM infer the growth of nano-crystalline cubic and hematite (α-Fe2O3) phase structures. IR reveals the ferrite phase abundance and metal ion replacement with dopant. Decreasing trend of lattice constant with dopant reflects the preferential replacement of Fe3+ions by Sb5+ion. Doping is found to cause for the decrease (i.e., 46-14 nm) of grain size. An overall trend of decreasing saturation magnetization is observed with doping. Low magnetization is attributed to the diamagnetic nature of dopant, abundance of hematite (α-Fe2O3) phase, non-stoichiometry and low temperature (800 °C) sintering conditions. Increasing Yafet-Kittel angle reflects surface spin canting to pronounce lower Ms. Lower coercivity is observed for x≤0.1, while a large Hc results for higher concentrations. High ac resistivity (~106 ohm-cm) and low dielectric loss factor (tan δ~10-2-10-3) are witnessed. Resistivity is explained on the base of a transformation in the Metal Cation-to-Oxide anion bond configuration and blockade of conductivity path. Retarded hopping (between adjacent B-sites) of carriers across the grain boundaries is addressed. Relatively higher resistivity and low dielectric loss in Sbdoped Mn-Zn ferrite systems pronounce their utility in high frequency applications.

  4. Lectin-mediated effects on bone resorption in vitro: a morphological and functional study

    SciTech Connect

    Popoff, S.N.

    1986-01-01

    Lectins have been used to study the structure and function of a variety of cells and tissues. The authors used 4 different lectins, concanavalin A (con A), wheat germ agglutinin (WGA), soybean agglutinin (SBA) and peanut agglutinin (PNA) as in vitro biological probes to study the osteoclast, a multinucleated bone cell that is widely accepted as the primary effector cell responsible for normal bone resorption. They evaluated the effects of each of these lectins on osteoclastic bone resorbing activity and then examined mechanisms that may be responsible for the activation and/or inhibition of osteoclastic activity. Using con A and hemocyanin, a marker molecule used to visualize cell-bound con A via scanning electron microscopy, they demonstrated that osteoclasts have specific con A binding sites on their cell surface. They conducted a series of /sup 45/Ca bone release assays demonstrating that con A has a dose-dependent biphasic effect on bone resorption; stimulation at low concentrations and inhibition at higher concentrations. The findings suggest that the specificity of lectin binding to cell surface receptors may play an important role in the induction of altered cell function. Recently, cells of the mononuclear phagocyte system have been proposed as surrogates of less readily available osteoclasts. They used a macrophage-devitalized bone culture system to evaluate the effects of con A and SBA on the attachment of macrophages to bone and their subsequent functional activity. The results showed that con A, but not SBA, alters the morphology and function of macrophages on a devitalized bone surface. The results support the hypothesis that certain, specific saccharides regulate the interaction between macrophages and bone.

  5. Maximal bite force, facial morphology and sucking habits in young children with functional posterior crossbite

    PubMed Central

    CASTELO, Paula Midori; GAVIÃO, Maria Beatriz Duarte; PEREIRA, Luciano José; BONJARDIM, Leonardo Rigoldi

    2010-01-01

    Objective The maintenance of normal conditions of the masticatory function is determinant for the correct growth and development of its structures. Thus, the aims of this study were to evaluate the influence of sucking habits on the presence of crossbite and its relationship with maximal bite force, facial morphology and body variables in 67 children of both genders (3.5-7 years) with primary or early mixed dentition. Material and methods The children were divided in four groups: primary-normocclusion (PN, n=19), primary-crossbite (PC, n=19), mixed-normocclusion (MN, n=13), and mixed-crossbite (MC, n=16). Bite force was measured with a pressurized tube, and facial morphology was determined by standardized frontal photographs: AFH (anterior face height) and BFW (bizygomatic facial width). Results It was observed that MC group showed lower bite force than MN, and AFH/ BFW was significantly smaller in PN than PC (t-test). Weight and height were only significantly correlated with bite force in PC group (Pearson’s correlation test). In the primary dentition, AFH/BFW and breast-feeding (at least six months) were positive and negatively associated with crossbite, respectively (multiple logistic regression). In the mixed dentition, breastfeeding and bite force showed negative associations with crossbite (univariate regression), while nonnutritive sucking (up to 3 years) associated significantly with crossbite in all groups (multiple logistic regression). Conclusions In the studied sample, sucking habits played an important role in the etiology of crossbite, which was associated with lower bite force and long-face tendency. PMID:20485925

  6. Effects of Excess Fluoride and Iodide on Thyroid Function and Morphology.

    PubMed

    Jiang, Yaqiu; Guo, Xiujuan; Sun, Qiuyan; Shan, Zhongyan; Teng, Weiping

    2016-04-01

    Exposure to high levels of iodide in Cangzhou, Shandong Province, China has been associated with increased incidence of thyroid disease; however, whether fluoride can affect the thyroid remains controversial. To investigate the effects of excess fluoride, we evaluated thyroid gland structure and function in rats exposed to fluoride and iodide, either alone or in combination. Five-week-old Wistar rats (n = 160 total) were randomly divided into eight groups: three groups that were given excess fluoride (15, 30, or 60 ppm F); one group given excess iodide (1200 μg/L I); three groups given excess iodide plus fluoride (1200 μg/L I plus 15, 30, or 60 ppm F); and one control group. The serum concentrations of the thyroid hormones TT3 and TT4 on day 150 were significantly reduced for certain fluoride groups; however, no significant differences were observed in concentrations for the pituitary hormone TSH among any groups. Hematoxylin and eosin staining revealed that iodide causes an increase in the areas of the colloid lumens and a decrease in the diameters of epithelial cells and nuclei; however, fluoride causes an increase in nuclear diameters. The damage to follicular epithelial cells upon fluoride or iodide treatment was easily observed by transmission electron microscopy, but the effects were most dramatic upon treatment with both fluoride and iodide. These results suggest that iodide causes the most damage but that fluoride can promote specific changes in the function and morphology of the thyroid, either alone or in combination with iodide.

  7. Why adductor magnus muscle is large: the function based on muscle morphology in cadavers.

    PubMed

    Takizawa, M; Suzuki, D; Ito, H; Fujimiya, M; Uchiyama, E

    2014-02-01

    The aim of this study was to examine anatomical properties of the adductor magnus through a detailed classification, and to hypothesize its function and size to gather enough information about morphology. Ten cadaveric specimens of the adductor magnus were used. The muscle was separated into four portios (AM1-AM4) based on the courses of the corresponding perforating arteries, and its volume, muscle length, muscle fiber length and physiological cross-sectional area were assessed. The architectural characteristics of these four portions of the adductor magnus were then classified with the aid of principal component analysis. The results led us into demarcating the most proximal part of the adductor magnus (AM1) from the remaining parts (AM2, AM3, and AM4). Classification of the adductor magnus in terms of architectural characteristics differed from the more traditional anatomical distinction. The AM2, AM3, and AM4, having longer muscle fiber lengths than the AM1, appear to be designed as displacers for moving the thigh through a large range of motion. The AM1 appears instead to be oriented principally toward stabilizing the hip joint. The large mass of the adductor magnus should thus be regarded as a complex of functionally differentiable muscle portions.

  8. Morphological and Functional Evaluation of Quadricuspid Aortic Valves Using Cardiac Computed Tomography

    PubMed Central

    Song, Inyoung; Park, Jung Ah; Choi, Bo Hwa; Shin, Je Kyoun; Chee, Hyun Keun; Kim, Jun Seok

    2016-01-01

    Objective The aim of this study was to identify the morphological and functional characteristics of quadricuspid aortic valves (QAV) on cardiac computed tomography (CCT). Materials and Methods We retrospectively enrolled 11 patients with QAV. All patients underwent CCT and transthoracic echocardiography (TTE), and 7 patients underwent cardiovascular magnetic resonance (CMR). The presence and classification of QAV assessed by CCT was compared with that of TTE and intraoperative findings. The regurgitant orifice area (ROA) measured by CCT was compared with severity of aortic regurgitation (AR) by TTE and the regurgitant fraction (RF) by CMR. Results All of the patients had AR; 9 had pure AR, 1 had combined aortic stenosis and regurgitation, and 1 had combined subaortic stenosis and regurgitation. Two patients had a subaortic fibrotic membrane and 1 of them showed a subaortic stenosis. One QAV was misdiagnosed as tricuspid aortic valve on TTE. In accordance with the Hurwitz and Robert's classification, consensus was reached on the QAV classification between the CCT and TTE findings in 7 of 10 patients. The patients were classified as type A (n = 1), type B (n = 3), type C (n = 1), type D (n = 4), and type F (n = 2) on CCT. A very high correlation existed between ROA by CCT and RF by CMR (r = 0.99) but a good correlation existed between ROA by CCT and regurgitant severity by TTE (r = 0.62). Conclusion Cardiac computed tomography provides comprehensive anatomical and functional information about the QAV. PMID:27390538

  9. Testing functional and morphological interpretations of enamel thickness along the deciduous tooth row in human children.

    PubMed

    Mahoney, Patrick

    2013-08-01

    The significance of a gradient in enamel thickness along the human permanent molar row has been debated in the literature. Some attribute increased enamel thickness from first to third molars to greater bite force during chewing. Others argue that thicker third molar enamel relates to a smaller crown size facilitated by a reduced dentin component. Thus, differences in morphology, not function, explains enamel thickness. This study draws on these different interpretive models to assess enamel thickness along the entire human deciduous tooth row. Average enamel thickness (AET), the area and proportion of crown enamel and dentin, and a crown size proxy are calculated for incisors, canines, and molars. Allometric scaling relationships are assessed within each tooth class, and then comparisons are undertaken along the row. Generally, AET was correlated with crown size and scaled with isometry, except for second molars which scaled with positive allometry. Mean AET increased along the row and was greater on molars, where bite forces are reported to be higher. Second molars combined the largest crown size with the thickest enamel and the smallest proportion of dentin, which is consistent with a reduction in the potential for cusp fracture under high bite forces. Resistance to wear may also account for some enamel thickness variation between tooth classes. Dental reduction did not explain the trend in AET from central to lateral incisors, or from first to second molars. The gradient in AET along the deciduous tooth row is partly consistent with a functional interpretation of enamel thickness.

  10. Functional morphology of feeding in the scale-eating specialist Catoprion mento.

    PubMed

    Janovetz, Jeff

    2005-12-01

    The wimple piranha, Catoprion mento, has a narrow-range natural diet with fish scales comprising an important proportion of its total food intake. Scales are eaten throughout most of ontogeny and adults feed almost exclusively on this food source. Catoprion exhibits a novel prey capture behavior when removing scales for ingestion. Scale feeding strikes involve a high-speed, open-mouth, ramming attack where the prey is bitten to remove scales and the force of the collision knocks scales free. Unique kinematic parameters of scale-feeding strikes include a mean gape angle of nearly 120 degrees and a ;plateau' stage of prolonged maximum displacement for cranial elevation and opercular expansion. When feeding on live fish or loose scales, Catoprion performs a typical ram/suction attack that is modulated according to the elusiveness of the prey. Captures of elusive fish elicit faster strikes with greater displacement of cranial elements than do attacks on loose scales sinking in the water column. Despite its specialized diet and suite of anatomical characters, functional versatility in feeding behavior has not been reduced in Catoprion, as predicted by many analogous studies in functional morphology. On the contrary, the behavioral repertoire of Catoprion has been broadened by the addition of a novel behavior for scale feeding.

  11. Synthesis and morphological evolution of inorganic nanoparticles in gas phase flames

    NASA Astrophysics Data System (ADS)

    Xing, Yangchuan

    The formation and growth of flame-generated inorganic nanoparticles at low particle volume fractions (ca. 0.1 ppm) were investigated experimentally. Alumina nanoparticles were synthesized from precursor trimethylaluminum in a well-defined/characterized laminar counterflow diffusion flame (CHsb4/Nsb2/Osb2) reactor. Experimental techniques included spatially resolved angle-dependent/polarized laser light scattering and thermophoretic sampling/TEM image analysis. Local aggregate morphology was characterized via. spherule size, aggregate size and aggregate fractal structure. The effects of flame temperature, precursor concentration and flame strain rate were also systematically studied. Higher precursor concentration resulted in larger spherule diameters, found to be in the range 13-26 nm under current experimental conditions. Nominal strain rate, varied from 11 to 20 ssp{-1}, was found to have a negligible effect on spherule size. Aggregate structure was characterized by fractal dimension, Dsb{f}, found by image analysis to be 1.55 ± 0.03 for aggregates without apparent restructuring (early in the flames). Dsb{f} approached 3 after the flame sheet due to the collapse of aggregates. Alumina aggregate morphological evolution was tracked using both TEM-image analysis and laser light scattering. Significant aggregate shrinkage due to high temperature sintering was found near the flame sheet, with a gyration-radius shrinkage rate of about 16 mum/s at temperatures near 2000 K. A theoretical approach was also developed to model spherule growth (and, hence, specific surface area) in such aerosol processes. This formulation, based on the competition between coalescence and Brownian coagulation rates, incorporates the surface melting concept into the surface self-diffusion coefficient, now dependent on particle size via. curvature and surface energy. This approach was used to calculate spherule growth in heating (and cooling) environments. Predicted spherule sizes show

  12. A morphological-approach for two-phase porous medium-transport and optimum design applications in energy engineering

    SciTech Connect

    Travkin, V.S.; Gratton, L.; Catton, I.

    1994-12-31

    Design optimization procedures for transport in porous structures that can be used in different engineering fields are developed for applications ranging from heat and mass exchangers and reactors in mechanical engineering design to environmental engineering usage. Using second order turbulent models, equation sets are obtained for turbulent filtration and two-temperature or two-concentration diffusion in non-isotropic porous media and interphase exchange and micro-roughness. The basis for transforming the integral-differential transport equations into differential equations with probability density functions governing their coefficients and source terms is accomplished by prescribing the statistical structure of the capillary or globular porous medium morphology. Though several different closure models for the source terms for uniform, non-uniform, non-isotropic and specifically random non-isotropic highly porous layers have been successfully developed, quite different situations arise when attempting to describe processes occurring in irregular or random morphologies. Results, obtained with the help of exact closure modeling for canonical morphologies, open a new field of possibilities for searching for optimal designs of spatial heterogeneous transport structures. A way to find and govern momentum transport through a capillary nonintersecting medium by altering its morphometric characteristics is given as validation of the process.

  13. Phase Function Determination in Support of Orbital Debris Size Estimation

    NASA Technical Reports Server (NTRS)

    Hejduk, M. D.; Cowardin, H. M.; Stansbery, Eugene G.

    2012-01-01

    To recover the size of a space debris object from photometric measurements, it is necessary to determine its albedo and basic shape: if the albedo is known, the reflective area can be calculated; and if the shape is known, the shape and area taken together can be used to estimate a characteristic dimension. Albedo is typically determined by inferring the object s material type from filter photometry or spectroscopy and is not the subject of the present study. Object shape, on the other hand, can be revealed from a time-history of the object s brightness response. The most data-rich presentation is a continuous light-curve that records the object s brightness for an entire sensor pass, which could last for tens of minutes to several hours: from this one can see both short-term periodic behavior as well as brightness variations with phase angle. Light-curve interpretation, however, is more art than science and does not lend itself easily to automation; and the collection method, which requires single-object telescope dedication for long periods of time, is not well suited to debris survey conditions. So one is led to investigate how easily an object s brightness phase function, which can be constructed from the more survey-friendly point photometry, can be used to recover object shape. Such a recovery is usually attempted by comparing a phase-function curve constructed from an object s empirical brightness measurements to analytically-derived curves for basic shapes or shape combinations. There are two ways to accomplish this: a simple averaged brightness-versus phase curve assembled from the empirical data, or a more elaborate approach in which one is essentially calculating a brightness PDF for each phase angle bin (a technique explored in unpublished AFRL/RV research and in Ojakangas 2011); in each case the empirical curve is compared to analytical results for shapes of interest. The latter technique promises more discrimination power but requires more data; the

  14. Prenatal and lactation nicotine exposure affects morphology and function of brown adipose tissue in male rat offspring.

    PubMed

    Fan, Jie; Ping, Jie; Zhang, Wan-Xia; Rao, Yi-Song; Liu, Han-Xiao; Zhang, Jing; Yan, You-E

    2016-01-01

    The aim of this study was to investigate the effects of prenatal and lactation nicotine exposure on the morphology and function of brown adipose tissue (BAT) in male rat offspring. We conducted a morphological assay and gene expression study of interscapular BAT (iBAT) in male rat offspring. The male offspring from nicotine-exposed dams exhibited higher body weight and iBAT weight. Hematoxylin and eosin staining and transmission electron microscopy showed that iBAT from nicotine-exposed male offspring presented a "whitening" phenotype characterized by lipid droplet accumulation and impaired mitochondria with a randomly oriented and fractured cristae. The expression of the iBAT structure and function-related genes all decreased in nicotine-exposed male offspring. These data indicate that prenatal and lactation nicotine exposure affects morphology and function of iBAT in male rat offspring.

  15. The relationship between perisylvian morphology and verbal short-term memory functioning in children with neurodevelopmental disorders.

    PubMed

    Kibby, Michelle Y; Kroese, Judith M; Morgan, Allison E; Hiemenz, Jennifer R; Cohen, Morris J; Hynd, George W

    2004-04-01

    Although children with neurodevelopmental disorders frequently present with reduced short-term memory functioning, the relationship between perisylvian morphology and verbal short-term memory functioning has received limited attention. Thus, examining this relationship in children with neurodevelopmental disorders was the focus of this exploratory study. Results suggested leftward asymmetry in the temporal bank of the planum temporale is related to better coding and storage of semantic material. In contrast, parietal bank morphology is related to coding and storage of phonological material, and presence of an extra gyrus in the parietal region is associated with reduced phonological working memory. Data also supported a relationship between pars triangularis morphology and verbal short-term memory functioning, but this is not material-specific.

  16. Re-analysis of previous laboratory phase curves: 2. Connections between opposition effect morphology and spectral features of stony meteorites

    NASA Astrophysics Data System (ADS)

    Déau, Estelle; Spilker, Linda J.; Flandes, Alberto

    2016-07-01

    We investigate connections between the opposition phase curves and the spectra from ultraviolet to near infrared wavelengths of stony meteorites. We use two datasets: the reflectance dataset of Capaccioni et al. ([1990] Icarus, 83, 325), which consists of optical phase curves (from 2° to 45°) of 17 stony meteorites (three carbonaceous chondrites, 11 ordinary chondrites, and three achondrites), and the spectral dataset from the RELAB database consisting of near-ultraviolet to near-infrared spectra of the same meteorites. We re-analyzed the first dataset and fit it with two morphological models to derive the amplitude A, the angular width HWHM of the surge and the slope S of the linear part. Our re-analysis confirms that stony meteorites have a non-monotonic behavior of the surge amplitude with albedo, which is also observed in planetary surfaces (Déau et al. [2013] Icarus, 226, 1465), laboratory samples (Nelson et al. [2004] Proc. Lunar Sci. Conf., 35, p. 1089) and asteroids (Belskaya and Shevchenko [2000] Icarus, 147, 94). We find a very strong correlation between the opposition effect morphological parameters and the slope of the spectra between 0.75 μm and 0.95 μm. In particular, we found that meteorites with a positive amplitude-albedo correlation have a positive spectral slope between 0.75 μm and 0.95 μm, while meteorites with a negative amplitude-albedo correlation have a negative spectral slope between 0.75 μm and 0.95 μm. We have ruled out the role of the meteorite samples' macro-properties (grain size, porosity and macroscopic roughness) in the correlations found because these properties were constant during the preparation of the samples. If this hypothesis is correct, this implies that other properties like the composition or the micro-properties (grain inclusions, grain shape or microscopic roughness) could have a preponderant role in the non-monotonic behavior of the surge morphology with albedo at small and moderate phase angles. Further

  17. [Functional morphology of recently discovered telocytes inside the female reproductive system].

    PubMed

    Božíková, S; Urban, L; Kajanová, M; Béder, I; Pohlodek, K; Varga, I

    2016-01-01

    Discovery of telocytes has become an important and key challenge in past few years. These cells are interstitial cells extending very long cytoplasmic processes named telopodes, by which they create functional networks in the interstitium of different organs. Telocytes are considered to be connective tissue elements that create contacts among each other, but they also function as intercellular structures, functionally connected with cells of the immune system, neurons and smooth muscle cells. Telocytes can be found also in the different parts of female reproductive system with functions and purpose, which is summarized in our overview. Telocytes regulate for example peristaltic movements in fallopian tubes. The decrease of their number (due to inflammatory disease or endometriosis) causes impairment in transport through fallopian tubes which may result in sterility or tubal gravidity. In uterus they regulate contraction of myometrial smooth muscle (blood expulsion in menstrual phase, childbirth) as well as they contribute in immunological care during embryo implantation. Telocytes probably control also the involution of uterus after delivery. Their function in vagina has not been yet clearly defined; they probably take part in slow muscle contraction movement during sexual intercourse. In mammary glands some scientists suppose their function in control of cell proliferation and apoptosis, that is why, they may play a role in carcinogenesis. In placenta they probably monitor and regulate flow of blood in vessels of chorionic villi and they may be responsible also for etiopathogenesis of pre-eclampsy. All these mentioned functions of telocytes are only in the level of hypothesis and have been published recently. New research and studies will try to answer the questions whether telocytes play a key role in these processes. Our review we completed with some original microphotographs of telocytes in different organs of female reproductive system.

  18. Synthesis and phase behavior of end-functionalized associating polymers

    NASA Astrophysics Data System (ADS)

    Wrue, Michelle H.

    We have explored polymer blend phase behavior in the presence of multiple hydrogen bonding end-groups. This work details the synthesis of functionalized polymers and their subsequent use in miscibility studies. The synthesis of end-functionalized hydrogen bonding polymers and the investigation of their physical properties and miscibility is presented. Mono-functional and telechelic ureidopyrimidinone (UPy) functionalized polymers were prepared by two main routes: post-polymerization functionalization (of commercially available or synthesized polymers); and polymerization of monomers using a functionalized initiator. UPy-functionalized polymers were prepared with a variety of polymer backbones including poly(ethylene oxide)s; poly(butadiene)s, poly(dimethyl siloxanxe)s; poly(styrene)s and poly(methyl methacrylate)s. The most successful route to polymers with UPy end-groups was atom transfer radical polymerization (ATRP) using a UPy-functionalized initiator, followed by atom transfer radical coupling (ATRC). The incorporation of ureidopyrimidinone end-groups was shown to affect the physical properties of the polymer backbone. Parent polymers that were liquids became viscous liquids or waxy solids upon UPy-functionalization of chain end. UPy-functionalization of a hydroxyl-terminated polybutadiene (HO-PB-OH) resulted in a waxy solid while the HO-PB-OH precursor was a viscous liquid. The thermal properties of functionalized polymers also differed from those of the unfunctionalized parent polymers. Hot-stage optical microscopy revealed that UPy-functionalized PEO displayed a depressed melting point relative to the analogous unfunctionalized precursor. Differential scanning calorimetry was also used to investigate the synthesized UPy-polymers. UPy-functionalized polystyrenes and poly(methyl methacrylate)s showed an increased T g compared to the equivalent homopolymer standards. This increased Tg was determined to be dependent upon the fraction of UPy groups present and

  19. Surface phase separation, dewetting feature size, and crystal morphology in thin films of polystyrene/poly(ε-caprolactone) blend.

    PubMed

    Ma, Meng; He, Zhoukun; Li, Yuhan; Chen, Feng; Wang, Ke; Zhang, Qing; Deng, Hua; Fu, Qiang

    2012-12-01

    Thin films of polystyrene (PS)/poly(ε-caprolactone) (PCL) blends were prepared by spin-coating and characterized by tapping mode force microscopy (AFM). Effects of the relative concentration of PS in polymer solution on the surface phase separation and dewetting feature size of the blend films were systematically studied. Due to the coupling of phase separation, dewetting, and crystallization of the blend films with the evaporation of solvent during spin-coating, different size of PS islands decorated with various PCL crystal structures including spherulite-like, flat-on individual lamellae, and flat-on dendritic crystal were obtained in the blend films by changing the film composition. The average distance of PS islands was shown to increase with the relative concentration of PS in casting solution. For a given ratio of PS/PCL, the feature size of PS appeared to increase linearly with the square of PS concentration while the PCL concentration only determined the crystal morphology of the blend films with no influence on the upper PS domain features. This is explained in terms of vertical phase separation and spinodal dewetting of the PS rich layer from the underlying PCL rich layer, leading to the upper PS dewetting process and the underlying PCL crystalline process to be mutually independent.

  20. Microstructural and Morphological Properties of Nanocrystalline Cu2ZnSnSe4 Thin Films: Identification New Phase on Structure

    NASA Astrophysics Data System (ADS)

    Quiroz, Heiddy P.; Seña, N. J.; Dussan, A.

    2014-04-01

    This paper presents a study of the structural and morphological properties of thin films of compound Cu2ZnSnSe4. Mass (MX) and temperature of the substrate (TS(Cu)) of compound copper (Cu), were varied. All samples were deposited by co-evaporation method in three stages. From measurements of X-ray diffraction it was possible to establish with TS increasing the presence of associated binary phases quaternary compound during the growth process of the material. It was found that the main peak around, 2θ= 27.1°, predominate binary phases Cu1.8Se and ZnSe. Measurements of X-ray diffraction were performed to pure binary compounds, showing a peak corresponding to the main peak found around the compound. Raman shifts showed associated binary compounds with the observed by XRD. In this work, we report for the first time the binary phase identification Cu1.8Se and ZnSe as part of the structure of the stannite CZTSe. Since the Scherrer equation was found that the crystallite sizes ranged between 30 and 40 nm. A correlation between structure and topography superficial is presented.

  1. SWDreader: A Wavelet-Based Algorithm Using Spectral Phase to Characterize Spike-Wave Morphological Variation in Genetic Models of Absence Epilepsy

    PubMed Central

    Richard, CD; Tanenbaum, A; Audit, B; Arneodo, A; Khalil, A; Frankel, WN

    2014-01-01

    Background Spike-wave discharges (SWD) found in neuroelectrical recordings are pathognomonic to absence epilepsy. The characteristic spike-wave morphology of the spike-wave complex (SWC) constituents of SWDs can be mathematically described by a subset of possible spectral power and phase values. Morlet wavelet transform (MWT) generates time-frequency representations well-suited to identifying this SWC-associated subset. New method MWT decompositions of SWDs reveal spectral power concentrated at harmonic frequencies. The phase relationships underlying SWC morphology were identified by calculating the differences between phase values at SWD fundamental frequency and the 2nd, 3rd and 4th harmonics. The three phase differences were then used as coordinates to generate a density distribution in a {360° × 360° × 360°} phase difference space. Strain-specific density distributions were generated from SWDs of mice carrying the Gria4, Gabrg2 or Scn8a mutations to determine whether SWC morphological variants reliably mapped to the same regions of the distribution, and if distribution values could be used to detect SWD. Comparison with existing methods To the best of our knowledge, this algorithm is the first to employ spectral phase to quantify SWC morphology, making it possible to computationally distinguish SWC subtypes and detect SWDs. Results/conclusions Proof-of-concept testing of the SWDreader algorithm shows: (1) a major pattern of variation in SWC morphology maps to one axis of the phase difference distribution, (2) variability between the strain-specific distributions reflects differences in the proportion of SWC subtypes generated during SWD, and (3) regularities in the spectral power and phase profiles of SWCs can be used to detect waveforms possessing SWC-like morphology. PMID:25549550

  2. Evolution of the axial system in craniates: morphology and function of the perivertebral musculature

    PubMed Central

    2011-01-01

    The axial musculoskeletal system represents the plesiomorphic locomotor engine of the vertebrate body, playing a central role in locomotion. In craniates, the evolution of the postcranial skeleton is characterized by two major transformations. First, the axial skeleton became increasingly functionally and morphologically regionalized. Second, the axial-based locomotion plesiomorphic for craniates became progressively appendage-based with the evolution of extremities in tetrapods. These changes, together with the transition to land, caused increased complexity in the planes in which axial movements occur and moments act on the body and were accompanied by profound changes in axial muscle function. To increase our understanding of the evolutionary transformations of the structure and function of the perivertebral musculature, this review integrates recent anatomical and physiological data (e.g., muscle fiber types, activation patterns) with gross-anatomical and kinematic findings for pivotal craniate taxa. This information is mapped onto a phylogenetic hypothesis to infer the putative character set of the last common ancestor of the respective taxa and to conjecture patterns of locomotor and muscular evolution. The increasing anatomical and functional complexity in the muscular arrangement during craniate evolution is associated with changes in fiber angulation and fiber-type distribution, i.e., increasing obliqueness in fiber orientation and segregation of fatigue-resistant fibers in deeper muscle regions. The loss of superficial fatigue-resistant fibers may be related to the profound gross anatomical reorganization of the axial musculature during the tetrapod evolution. The plesiomorphic function of the axial musculature -mobilization- is retained in all craniates. Along with the evolution of limbs and the subsequent transition to land, axial muscles additionally function to globally stabilize the trunk against inertial and extrinsic limb muscle forces as well as

  3. NMJ-morph reveals principal components of synaptic morphology influencing structure–function relationships at the neuromuscular junction

    PubMed Central

    Jones, Ross A.; Reich, Caitlan D.; Dissanayake, Kosala N.; Kristmundsdottir, Fanney; Findlater, Gordon S.; Ribchester, Richard R.; Simmen, Martin W.

    2016-01-01

    The ability to form synapses is one of the fundamental properties required by the mammalian nervous system to generate network connectivity. Structural and functional diversity among synaptic populations is a key hallmark of network diversity, and yet we know comparatively little about the morphological principles that govern variability in the size, shape and strength of synapses. Using the mouse neuromuscular junction (NMJ) as an experimentally accessible model synapse, we report on the development of a robust, standardized methodology to facilitate comparative morphometric analysis of synapses (‘NMJ-morph’). We used NMJ-morph to generate baseline morphological reference data for 21 separate pre- and post-synaptic variables from 2160 individual NMJs belonging to nine anatomically distinct populations of synapses, revealing systematic differences in NMJ morphology between defined synaptic populations. Principal components analysis revealed that overall NMJ size and the degree of synaptic fragmentation, alongside pre-synaptic axon diameter, were the most critical parameters in defining synaptic morphology. ‘Average’ synaptic morphology was remarkably conserved between comparable synapses from the left and right sides of the body. Systematic differences in synaptic morphology predicted corresponding differences in synaptic function that were supported by physiological recordings, confirming the robust relationship between synaptic size and strength. PMID:27927794

  4. Increasing trunk flexion transforms human leg function into that of birds despite different leg morphology.

    PubMed

    Aminiaghdam, Soran; Rode, Christian; Müller, Roy; Blickhan, Reinhard

    2017-02-01

    Pronograde trunk orientation in small birds causes prominent intra-limb asymmetries in the leg function. As yet, it is not clear whether these asymmetries induced by the trunk reflect general constraints on the leg function regardless of the specific leg architecture or size of the species. To address this, we instructed 12 human volunteers to walk at a self-selected velocity with four postures: regular erect, or with 30 deg, 50 deg and maximal trunk flexion. In addition, we simulated the axial leg force (along the line connecting hip and centre of pressure) using two simple models: spring and damper in series, and parallel spring and damper. As trunk flexion increases, lower limb joints become more flexed during stance. Similar to birds, the associated posterior shift of the hip relative to the centre of mass leads to a shorter leg at toe-off than at touchdown, and to a flatter angle of attack and a steeper leg angle at toe-off. Furthermore, walking with maximal trunk flexion induces right-skewed vertical and horizontal ground reaction force profiles comparable to those in birds. Interestingly, the spring and damper in series model provides a superior prediction of the axial leg force across trunk-flexed gaits compared with the parallel spring and damper model; in regular erect gait, the damper does not substantially improve the reproduction of the human axial leg force. In conclusion, mimicking the pronograde locomotion of birds by bending the trunk forward in humans causes a leg function similar to that of birds despite the different morphology of the segmented legs.

  5. Zebrafish mesonephric renin cells are functionally conserved and comprise two distinct morphological populations.

    PubMed

    Rider, Sebastien A; Christian, Helen C; Mullins, Linda J; Howarth, Amelia R; MacRae, Calum A; Mullins, John J

    2017-04-01

    Zebrafish provide an excellent model in which to assess the role of the renin-angiotensin system in renal development, injury, and repair. In contrast to mammals, zebrafish kidney organogenesis terminates with the mesonephros. Despite this, the basic functional structure of the nephron is conserved across vertebrates. The relevance of teleosts for studies relating to the regulation of the renin-angiotensin system was established by assessing the phenotype and functional regulation of renin-expressing cells in zebrafish. Transgenic fluorescent reporters for renin (ren), smooth muscle actin (acta2), and platelet-derived growth factor receptor-beta (pdgfrb) were studied to determine the phenotype and secretory ultrastructure of perivascular renin-expressing cells. Whole kidney ren transcription responded to altered salinity, pharmacological renin-angiotensin system inhibition, and renal injury. Mesonephric ren-expressing cells occupied niches at the preglomerular arteries and afferent arterioles, forming intermittent epithelioid-like multicellular clusters exhibiting a granular secretory ultrastructure. In contrast, renin cells of the efferent arterioles were thin bodied and lacked secretory granules. Renin cells expressed the perivascular cell markers acta2 and pdgfrb Transcriptional responses of ren to physiological challenge support the presence of a functional renin-angiotensin system and are consistent with the production of active renin. The reparative capability of the zebrafish kidney was harnessed to demonstrate that ren transcription is a marker for renal injury and repair. Our studies demonstrate substantive conservation of renin regulation across vertebrates, and ultrastructural studies of renin cells reveal at least two distinct morphologies of mesonephric perivascular ren-expressing cells.

  6. Kinesin family 17 (osmotic avoidance abnormal-3) is dispensable for photoreceptor morphology and function

    PubMed Central

    Jiang, Li; Tam, Beatrice M.; Ying, Guoxing; Wu, Sen; Hauswirth, William W.; Frederick, Jeanne M.; Moritz, Orson L.; Baehr, Wolfgang

    2015-01-01

    In Caenorhabditis elegans, homodimeric [kinesin family (KIF) 17, osmotic avoidance abnormal-3 (OSM-3)] and heterotrimeric (KIF3) kinesin-2 motors are required to establish sensory cilia by intraflagellar transport (IFT) where KIF3 and KIF17 cooperate to build the axoneme core and KIF17 builds the distal segments. However, the function of KIF17 in vertebrates is unresolved. We expressed full-length and motorless KIF17 constructs in mouse rod photoreceptors using adeno-associated virus in Xenopus laevis rod photoreceptors using a transgene and in ciliated IMCD3 cells. We found that tagged KIF17 localized along the rod outer segment axoneme when expressed in mouse and X. laevis photoreceptors, whereas KIF3A was restricted to the proximal axoneme. Motorless KIF3A and KIF17 mutants caused photoreceptor degeneration, likely through dominant negative effects on IFT. KIF17 mutant lacking the motor domain translocated to nuclei after exposure of a C-terminal nuclear localization signal. Germ-line deletion of Kif17 in mouse did not affect photoreceptor function. A rod-specific Kif3/Kif17 double knockout mouse demonstrated that KIF17 and KIF3 do not act synergistically and did not prevent rhodopsin trafficking to rod outer segments. In summary, the nematode model of KIF3/KIF17 cooperation apparently does not apply to mouse photoreceptors in which the photosensory cilium is built exclusively by KIF3.—Jiang, L., Tam, B. M., Ying, G., Wu, S., Hauswirth, W. W., Frederick, J. M., Moritz, O. L., Baehr, W. Kinesin family 17 (osmotic avoidance abnormal-3) is dispensable for photoreceptor morphology and function. PMID:26229057

  7. Comparing Two Intestinal Porcine Epithelial Cell Lines (IPECs): Morphological Differentiation, Function and Metabolism

    PubMed Central

    Nossol, Constanze; Barta-Böszörményi, Anicò; Kahlert, Stefan; Zuschratter, Werner; Faber-Zuschratter, Heidi; Reinhardt, Nicole; Ponsuksili, Siriluk; Wimmers, Klaus; Diesing, Anne-Kathrin; Rothkötter, Hermann-Josef

    2015-01-01

    The pig shows genetical and physiological resemblance to human, which predestines it as an experimental animal model especially for mucosal physiology. Therefore, the intestinal epithelial cell lines 1 and J2 (IPEC-1, IPEC-J2) - spontaneously immortalised cell lines from the porcine intestine - are important tools for studying intestinal function. A microarray (GeneChip Porcine Genome Array) was performed to compare the genome wide gene expression of IPECs. Different significantly up-regulated pathways were identified, like “lysosome”, “pathways in cancer”, “regulation of actin cytoskeleton” and “oxidative phosphorylation” in IPEC-J2 in comparison to IPEC-1. On the other hand, “spliceosome”, “ribosome”, “RNA-degradation” and “tight junction” are significantly down-regulated pathways in IPEC-J2 in comparison to IPEC-1. Examined pathways were followed up by functional analyses. ATP-, oxygen, glucose and lactate-measurement provide evidence for up-regulation of oxidative phosphorylation in IPEC-J2. These cells seem to be more active in their metabolism than IPEC-1 cells due to a significant higher ATP-content as well as a higher O2- and glucose-consumption. The down-regulated pathway “ribosome” was followed up by measurement of RNA- and protein content. In summary, IPEC-J2 is a morphologically and functionally more differentiated cell line in comparison to IPEC-1. In addition, IPEC-J2 cells are a preferential tool for in vitro studies with the focus on metabolism. PMID:26147118

  8. Organic Composition and Morphology of Sea Spray Aerosols as a Function of Biological Life during IMPACTS

    NASA Astrophysics Data System (ADS)

    Pham, D.; Moffet, R.; Fraund, M. W.; O'Brien, R.; Laskina, O.; Prather, K. A.; Grassian, V. H.; Beall, C.; Wang, X.; Forestieri, S.; Cappa, C. D.

    2015-12-01

    Aerosols influence climate by directly reflecting or absorbing sunlight, or indirectly by affecting clouds. A major source of aerosols is from oceanic wave breaking. Due to their complexity, the effects of marine aerosol on climate are uncertain. To provide more detailed measurements of the chemical composition of marine aerosols, Scanning Transmission X-Ray Microscopy coupled with Near Edge X-Ray Absorption Fine Structure (SXTM-NEXAFS) was used to give spatially resolved molecular information for carbon and oxygen. Application of STXM/NEXAFS to particles collected during a mesocosm study using a unique wave channel facility to generate aerosols shows that the organic volume fraction of aerosols at the aerodynamic diameter size range of 0.18-0.32 μm are a direct function of the biological activity in the sea water. Aerosol organic volume fraction increased from 0.32 for particles generated from seawater containing low biolife to 0.49 and 0.40 for particles produced during phytoplankton blooms. However, the organic volume fraction of aerosols at the aerodynamic diameter size range of 0.56-1 μm did not change with biological activity. Measurements also show that different types of organics can concentrate into aerosols depending on the enzyme activity expressed at the time. Enhanced spectral signatures for aliphatic hydrocarbons were observed during the first phytoplankton bloom compared to a second phytoplankton bloom occurring directly thereafter. The decreased signature of aliphatic organics in the second phytoplankton bloom was correlated with increased lipase activity from heterobacteria. Organic aggregates having similar morphology also differ in composition from their carbon spectra from the two blooms. For July 17, organic aggregates were much richer in hydrocarbons, which showed a remarkably intense C-H absorbance and a broad C-C absorbance. Organic aggregates observed for July 26-27, did not have the C-H and C-C signatures, but contained more polar

  9. Superplasticity in ceramic and metal matrix composites and the role of grain size, segregation, interfaces, and second phase morphology

    SciTech Connect

    Wadsworth, J.; Nieh, T.G.

    1992-10-01

    Structural ceramics and ceramic composites have been shown to exhibit superplasticity in recent times and this discovery has attracted tremendous interest. Although the number of ceramics exhibits superplasticity is now quite large, there are gaps in understanding the requirements for superplasticity in ceramics. Also, superplastic behavior at very high strain rates (1 s{sup {minus}1}) in metallic-based materials is an area of increasing research. In this case, the phenomenon has been observed quite extensively in aluminum alloy-based metal matrix composites and mechanically alloyed aluminum- and nickel-based materials. Again, the details of the structural requirements of this phenomenon are not yet understood. In the present paper, experimental results on superplasticity in ceramic-based materials and on high strain rate behavior in metallic-based materials are presented. The roles of grain size, grain boundary and interface chemistry, and second phase morphology and compatibility with the matrix material will be emphasized.

  10. Pineal gland as an endocrine gravitational lunasensor: manifestation of moon-phase dependent morphological changes in mice.

    PubMed

    Gerasimov, A V; Kostyuchenko, V P; Solovieva, A S; Olovnikov, A M

    2014-10-01

    We found that some morphological properties of the pineal gland and submandibular salivary gland of mice are significantly distinct at the new and full moon. We suppose that the differences are initiated by the displacements of the electron-dense concretions in the secretory vesicles of pinealocytes. This presumably occurs under the influence of the gravitational field, which periodically changes during different phases of the moon. It seems that the pinealocyte is both an endocrine and gravisensory cell. A periodic secretion of the pineal gland probably stimulates, in a lunaphasic mode, the neuroendocrine system that, in turn, periodically exerts influence on different organs of the body. The observed effect probably serves, within the lifelong clock of a brain, to control development and aging in time.

  11. The effect of HNO3 on morphology, phase transformation, and luminescence properties of LaPO4:Eu3+ phosphors

    NASA Astrophysics Data System (ADS)

    Zhou, Ruisen; Lv, Meng; Li, Xia

    2016-01-01

    LaPO4:Eu3+ powders with different morphologies were hydrothermally constructed by adjusting the amount of HNO3 without using a catalyst, surfactant, or template. The as-prepared products were characterized by photoluminescence spectroscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM), high resolution-transmission electron microscopy (HR-TEM), selected area electron diffraction (SAED), X-ray diffraction (XRD), infrared (IR) spectra, and X-ray photoelectron spectroscopy. The SEM study revealed that the amount of HNO3 played a crucial role in the morphology of the final products. The XRD results indicated that the as-prepared samples were in the monoclinic phase when 3 mL of HNO3 was used. The HR-TEM micrographs and SAED results demonstrated that the prepared nanorods were single and crystalline in nature with HNO3, and that they grew preferentially along the [0 1 2] direction. The emission spectra showed that the LaPO4:Eu3+ samples had the strongest emission intensity when prepared with HNO3.

  12. Antibacterial activity of TiO2 nanotubes: Influence of crystal phase, morphology and Ag deposition

    NASA Astrophysics Data System (ADS)

    Li, Huirong; Cui, Qiang; Feng, Bo; Wang, Jianxin; Lu, Xiong; Weng, Jie

    2013-11-01

    TiO2 nanotubes on Ti substrate were fabricated by electrochemical anodization. Ag nanoparticles were deposited on the TiO2 nanotubes by a silver mirror reaction. Antibacterial activity of the nanotubes with different structural features was evaluated by a culture test with Escherichia coli bacteria. The anatase nanotubes showed the highest antibacterial activity among three crystal phases including anatase, rutile and amorphous titania. The diameters of the nanotubes affected the antibacterial activity. The two nanotubes with 200 nm and 50 nm diameters had higher antibacterial rate than those with other diameters. The antibacterial activity of the nanotubes was independent on their lengths. Ag-deposited nanotubes exhibited excellent antibacterial activity and its antibacterial rate was up to approximately 100%. TiO2 nanotubes and Ag-deposited nanotubes on titanium should be potential for antibacterial applications in clinics and industry, especially regarding with their reusability.

  13. High Resolution Electro-Optical Aerosol Phase Function Database PFNDAT2006

    DTIC Science & Technology

    2006-08-01

    Mie phase functions by using the Monte Carlo code MSCAT (29). MSCAT predicts... Greenstein snow phase function with the traditional Mie generated phase function . We corrected the following errors: the refractive index of white...is sufficiently large. One such approximation is the Henyey - Greenstein (HG) phase function (5): , ))cos(21( 1 4 1),( 2/32 2 gg ggPHG +− − = θπ

  14. Understanding the influence of alendronate on the morphology and phase transformation of apatitic precursor nanocrystals.

    PubMed

    Zhang, Guiling; Huang, Rong; Li, Zhicheng; Yang, Xianyan; Chen, Xiaoyi; Xia, Wei; Sun, Xiaoliang; Yang, Guojing; Gao, Changyou; Gou, Zhongru

    2012-08-01

    Bisphosphonates (BPs) are a class of synthetic pyrophosphate analogs that can prevent the loss of bone mass, given orally to treat postmenopuasal osteoporosis. It is not clear yet if the benefits of BPs include the possibility of affecting bone apatitic precursors transition for bone consolidation except for encouraging osteoclasts to undergo apoptosis. Furthermore, the complexity of the in vivo system makes it difficult to isolate and study such extracellular topographical cues that trigger bone turnover response. Herein, we proposed a wet-chemical approach employing alendronate sodium (AS) as a guide of hydroxyapatite (HA) precursor growth and conversion which was initiated from the nucleantion of octacalcium phosphate (OCP) in a cell membrane-mimicking surfactant micelle aqueous system. The nanocrystal clusters of dicalcium phosphate dihydrate (DCPD) and OCP nanocryatals were readily precipitated within a relatively narrow AS concentration range (2-8 μM). However, such low concentrations of AS seemed to stabilize the more acidic phases, and to delay the transformation into HA, to an extent which increased on increasing AS concentration. In contrast, at a slight higher concentrations (16-32 μM), AS promoted HA precipitation after ageing for 1h. It was found that the effect of AS on the phase selectivity of apatitic precursors was concentration-dependent within a prolonged ageing time stage (0.5-168 h). The AS-assisted reactions in vitro offer an expedient way to understand the underlying implementarity between bone and BPs for bone consolidation, and to improve our understanding of benefit of BP dosages on bone turnover and trauma healing.

  15. Phase Transformation and Morphology of Calcium Phosphate Prepared by Electrochemical Deposition Process Through Alkali Treatment and Calcination

    NASA Astrophysics Data System (ADS)

    Chen, Hui-Ting; Wang, Moo-Chin; Chang, Kuo-Ming; Wang, Szu-Hao; Shih, Wei-Jen; Li, Wong-Long

    2014-04-01

    The phase transformation and morphology of calcium phosphate prepared by the electrochemical deposition (ECD) process through alkali treatment and calcination have been characterized using X-ray diffraction (XRD), thermogravimetry and differential thermal analyses (TG/DTA), and scanning electron microscopy (SEM). At the ECD process, when the excess OH- was produced, the reaction of 10Ca2++6PO{4/3-}+2OH-→Ca10(PO4)6(OH)2 takes place on the Ti-6Al-4V and the HA is deposited. The XRD results reveal that the as-deposit was mostly composed of dicalcium phosphate dehydrate (Ca2H4P2O9; DCPD) and the minor phase of hydroxyapatite (Ca10(PO4)6(OH)2; HA). After NaOH treatment, all DCPD were converted to HA. Moreover, the content of HA phase increases with ECD potential. After being calcined at 673 K and 873 K (400 °C and 600 °C) for 4 hours, the phase of HA maintained the major phase for an alkali-treated deposited sample. After being calcined at 1073 K (800 °C) for 4 hours, some HA decomposed and caused the minor phases of β-tricalcium phosphate ( β-Ca3(PO4)2; β-TCP), calcium pyrophosphate (Ca2P2O7; CPP), and calcium oxide (CaO) formation. The β-TCP becomes the major phase with residual HA and CaO after being calcined at 1273 K (1000 °C) for 4 hours. The crack forms due to the release of absorbed water from the interior to top surface of sample. For the as-alkali treatment samples, the microstructures were affected by ECD potentials; when the deposited samples after alkali treatment and calcined at 1073 K (800 °C) for 4 hours, the microstructure presents the need-like "preforming HA" (pre-HA) from the matrix of plate-like postforming HA (post-HA).

  16. Changes in platelet morphology and function during 24 hours of storage.

    PubMed

    Braune, S; Walter, M; Schulze, F; Lendlein, A; Jung, F

    2014-01-01

    For in vitro studies assessing the interaction of platelets with implant materials, common and standardized protocols for the preparation of platelet rich plasma (PRP) are lacking, which may lead to non-matching results due to the diversity of applied protocols. Particularly, the aging of platelets during prolonged preparation and storage times is discussed to lead to an underestimation of the material thrombogenicity. Here, we study the influence of whole blood- and PRP-storage times on changes in platelet morphology and function. Blood from apparently healthy subjects was collected according to a standardized protocol and examined immediately after blood collection, four hours and twenty four hours later. The capability of platelets to adhere and form stable aggregates (PFA100, closure time) was examined in sodium citrate anticoagulated whole blood (WB) using the agonists equine type I collagen and epinephrine bitartrate (collagen/epinephrine) as well as equine type I collagen and adenosine-5'-diphosphate (collagen/ADP). Circulating platelets were quantified at each time point. Morphology of platelets and platelet aggregates were visualized microscopically and measured using an electric field multi-channel counting system (CASY). The percentage of activated platelets was assessed by means of P-selectin (CD62P) expression of circulating platelets. Furthermore, platelet factor 4 (PF4) release was measured in platelet poor plasma (PPP) at each time point. Whole blood PFA100 closure times increased after stimulation with collagen/ADP and collagen/epinephrine. Twenty four hours after blood collection, both parameters were prolonged pathologically above the upper limit of the reference range. Numbers of circulating platelets, measured in PRP, decreased after four hours, but no longer after twenty four hours. Mean platelet volumes (MPV) and platelet large cell ratios (P-LCR, 12 fL - 40 fL) decreased over time. Immediately after blood collection, no debris or platelet

  17. Morphological and functional recovery of the planarian photosensing system during head regeneration.

    PubMed

    Inoue, Takeshi; Kumamoto, Hiroshi; Okamoto, Keiji; Umesono, Yoshihiko; Sakai, Masaki; Sánchez Alvarado, Alejandro; Agata, Kiyokazu

    2004-03-01

    When exposed to light, planarians display a distinctive light avoidance behavior known as negative phototaxis. Such behavior is temporarily suppressed when animals are decapitated, and it is restored once the animals regenerate their heads. Head regeneration and the simple but reproducible phototactic response of planarians provides an opportunity to study the association between neuronal differentiation and the establishment of behavior in a simple, experimentally tractable metazoan. We have devised a phototaxis assay system to analyze light response recovery during head regeneration and determined that light evasion is markedly re-established 5 days after amputation. Immunohistological and in situ hybridization studies indicate that the photoreceptors and optic nerve connections to the brain begin by the fourth day of cephalic regeneration. To experimentally manipulate the light response recovery, we performed gene knockdown analysis using RNA interference (RNAi) on two genes (1020HH and eye53) previously reported to be expressed at 5 days after amputation and in the dorso-medial region of the brain (where the optic nerves project). Although RNAi failed to produce morphological defects in either the brain or the visual neurons, the recovery of the phototactic response normally observed in 5-day regenerates was significantly suppressed. The data suggest that 1020HH and eye53 may be involved in the functional recovery and maintenance of the visual system, and that the phototaxis assay presented here can be used to reliably quantify the negative phototactic behavior of planarians.

  18. Functional morphology of femoral glands in the Tegu lizard, Tupinambis merianae.

    PubMed

    Chamut, Silvia; Valdez, Valeria García; Manes, Mario E

    2009-04-01

    Several lizards have femoral glands, which have an influence in various reproductive behaviors. In this paper we describe the morphological organization of the femoral glands in the Tegu, Tupinambis merianae, by means of light and electron microscopy. Even though these glands are present in both genders, secretions during the reproductive period can only be found in males. The glandular parenchyma, which is organized in numerous secretory units, consists of keratinocyte-like cells and granular cells. The holocrine secretion is constituted from both cells, which lose their integrity and become a semi-amorphous material, reinforced by keratin sheets. The discharges of each unit merge together into a solid cylinder of secretion, surrounded by epithelial cells, that is extruded to the exterior. The keratin sheets and epithelial layers that surround both the complete and partial secretions form a sort of structural support suitable for the type of territorial demarcation characteristic of the species. The granular cells, supposedly the producers of pheromones, are characterized by the presence of electron-dense granules and multilaminar membranous bodies that show ultrastructural changes of unknown function. The free granules in the secretion cylinder may act as pheromone deposits.

  19. Specific degradation of phosphatidylglycerol is necessary for proper mitochondrial morphology and function.

    PubMed

    Pokorná, Lucia; Čermáková, Petra; Horváth, Anton; Baile, Matthew G; Claypool, Steven M; Griač, Peter; Malínský, Jan; Balážová, Mária

    2016-01-01

    In yeast, phosphatidylglycerol (PG) is a minor phospholipid under standard conditions; it can be utilized for cardiolipin (CL) biosynthesis by CL synthase, Crd1p, or alternatively degraded by the phospholipase Pgc1p. The Saccharomyces cerevisiae deletion mutants crd1Δ and pgc1Δ both accumulate PG. Based on analyses of the phospholipid content of pgc1Δ and crd1Δ yeast, we revealed that in yeast mitochondria, two separate pools of PG are present, which differ in their fatty acid composition and accessibility for Pgc1p-catalyzed degradation. In contrast to CL-deficient crd1Δ yeast, the pgc1Δ mutant contains normal levels of CL. This makes the pgc1Δ strain a suitable model to study the effect of accumulation of PG per se. Using fluorescence microscopy, we show that accumulation of PG with normal levels of CL resulted in increased fragmentation of mitochondria, while in the absence of CL, accumulation of PG led to the formation of large mitochondrial sheets. We also show that pgc1Δ mitochondria exhibited increased respiration rates due to increased activity of cytochrome c oxidase. Taken together, our results indicate that not only a lack of anionic phospholipids, but also excess PG, or unbalanced ratios of anionic phospholipids in mitochondrial membranes, have harmful consequences on mitochondrial morphology and function.

  20. Morphology, Ultrastructure and Possible Functions of Antennal Sensilla of Sitodiplosis mosellana Géhin (Diptera: Cecidomyiidae)

    PubMed Central

    Wang, Yue; Li, Dan; Liu, Yang; Li, Xue-Jiao; Cheng, Wei-Ning; Zhu-Salzman, Keyan

    2016-01-01

    To better understand the olfactory receptive mechanisms involved in host selection and courtship behavior of Sitodiplosis mosellana (Diptera: Cecidomyiidae), one of the most important pests of wheat, scanning and transmission electron microscopy were used to examine the external morphology and ultrastructure of the antennal sensilla. The moniliform antennae exhibit obvious sexual dimorphism: antennae of the males are markedly longer than those of the females. Furthermore, each male flagellomere consists of two globular nodes, whereas each female flagellomere is cylindrical. Seven types of sensilla were identified in both sexes. Two types of s. chaetica have a lumen without dendrites and thick walls, suggesting that they are mechanoreceptors. S. trichodea and s. circumfila are typical chemoreceptors, possessing thin multiporous walls encircling a lumen with multiple dendrites. There are significantly more s. trichodea in female than in male, which may be related to host plant localization. In contrast, male s. circumfila are highly elongated compared to those of females, perhaps for pheromone detection. Peg-shaped s. coeloconica are innervated with unbranched dendrites extending from the base to the distal tip. Type 1 s. coeloconica, which have deep longitudinal grooves and finger-like projections on the surface, may serve as olfactory or humidity receptors, whereas type 2 s. coeloconica, smooth with a terminal pore, may be contact chemoreceptors. Also, this is the first report of Böhm’ bristles at proximal scape on antennae of Cecidomyiid species potentially functioning as mechanoreceptors. PMID:27623751

  1. Effects of intra-abdominal pressure on adrenal gland function and morphology in rats.

    PubMed

    Akkapulu, Nezih; Tirnaksiz, Mehmet Bulent; Kulac, Ibrahim; Tezel, Gaye Guler; Hayran, Mutlu; Dogrul, Ahmet Bulent; Cetinkaya, Erdinc; Yorganci, Kaya

    2015-01-01

    Intra-abdominal hypertension and abdominal compartment syndrome (IAH/ACS) are life-threatening conditions and caused by several clinical status. Although there is insufficient data regarding its effects on adrenal glands. This study aimed to identify whether elevated intra-abdominal pressure (IAP) caused any alteration on the morphology and function of adrenal glands in a rat model. Twenty four Sprague-Dawley male rats were included in the study. Animals were allocated into 4 groups. IAP was elevated to 15 mmHg for one hour and four hours in group 2 and 4. Group 1 and 3 were sham groups. Blood samples were taken for the assessment of plasma adrenaline, noradrenaline, and corticosterone levels and adrenalectomies were performed to evaluate apoptosis. Blood adrenaline, noradrenaline and corticosterone levels were significantly higher in the study groups compared with the sham groups. However, there were no significant changes in apoptotic index scores in the study groups as compared to sham groups. These results support that increased IAH leads to discharge of catecholamine and corticosterone from the adrenal glands. Failure to demonstrate similar changes in apoptotic index score may be concluded as apoptosis is not a leading pathway for impairment of adrenal glands during IAH period.

  2. Chemical, morphological and functional properties of Brazilian jackfruit (Artocarpus heterophyllus L.) seeds starch.

    PubMed

    Madruga, Marta Suely; de Albuquerque, Fabíola Samara Medeiros; Silva, Izis Rafaela Alves; do Amaral, Deborah Silva; Magnani, Marciane; Queiroga Neto, Vicente

    2014-01-15

    Starches used in food industry are extracted from roots, tubers and cereals. Seeds of jackfruit are abundant and contain high amounts of starch. They are discarded during the fruit processing or consumption and can be an alternative source of starch. The starch was extract from the jackfruit seeds and characterised to chemical, morphological and functional properties. Soft and hard jackfruit seeds showed starch content of 92.8% and 94.5%, respectively. Starch granules showed round and bell shape and some irregular cuts on their surface with type-A crystallinity pattern, similar to cereals starches. The swelling power and solubility of jackfruit starch increased with increasing temperature, showing opaque pastes. The soft seeds starch showed initial and final gelatinisation temperature of 36°C and 56°C, respectively; while hard seeds starch presented initial gelatinisation at 40°C and final at 61°C. These results suggest that the Brazilian jackfruit seeds starches could be used in food products.

  3. Inferring parrotfish (Teleostei: Scaridae) pharyngeal mill function from dental morphology, wear, and microstructure.

    PubMed

    Carr, Andrew; Tibbetts, Ian R; Kemp, Anne; Truss, Rowan; Drennan, John

    2006-10-01

    Morphology, occlusal surface topography, macrowear, and microwear features of parrotfish pharyngeal teeth were investigated to relate microstructural characteristics to the function of the pharyngeal mill using scanning electron microscopy of whole and sectioned pharyngeal jaws and teeth. Pharyngeal tooth migration is anterior in the lower jaw (fifth ceratobranchial) and posterior in the upper jaw (paired third pharyngobranchials), making the interaction of occlusal surfaces and wear-generating forces complex. The extent of wear can be used to define three regions through which teeth migrate: a region containing newly erupted teeth showing little or no wear; a midregion in which the apical enameloid is swiftly worn; and a region containing teeth with only basal enameloid remaining, which shows low to moderate wear. The shape of the occlusal surface alters as the teeth progress along the pharyngeal jaw, generating conditions that appear suited to the reduction of coral particles. It is likely that the interaction between these particles and algal cells during the process of the rendering of the former is responsible for the rupture of the latter, with the consequent liberation of cell contents from which parrotfish obtain their nutrients.

  4. Morphology, Ultrastructure and Possible Functions of Antennal Sensilla of Sitodiplosis mosellana Géhin (Diptera: Cecidomyiidae).

    PubMed

    Wang, Yue; Li, Dan; Liu, Yang; Li, Xue-Jiao; Cheng, Wei-Ning; Zhu-Salzman, Keyan

    2016-01-01

    To better understand the olfactory receptive mechanisms involved in host selection and courtship behavior of Sitodiplosis mosellana (Diptera: Cecidomyiidae), one of the most important pests of wheat, scanning and transmission electron microscopy were used to examine the external morphology and ultrastructure of the antennal sensilla. The moniliform antennae exhibit obvious sexual dimorphism: antennae of the males are markedly longer than those of the females. Furthermore, each male flagellomere consists of two globular nodes, whereas each female flagellomere is cylindrical. Seven types of sensilla were identified in both sexes. Two types of s. chaetica have a lumen without dendrites and thick walls, suggesting that they are mechanoreceptors. S. trichodea and s. circumfila are typical chemoreceptors, possessing thin multiporous walls encircling a lumen with multiple dendrites. There are significantly more s. trichodea in female than in male, which may be related to host plant localization. In contrast, male s. circumfila are highly elongated compared to those of females, perhaps for pheromone detection. Peg-shaped s. coeloconica are innervated with unbranched dendrites extending from the base to the distal tip. Type 1 s. coeloconica, which have deep longitudinal grooves and finger-like projections on the surface, may serve as olfactory or humidity receptors, whereas type 2 s. coeloconica, smooth with a terminal pore, may be contact chemoreceptors. Also, this is the first report of Böhm' bristles at proximal scape on antennae of Cecidomyiid species potentially functioning as mechanoreceptors.

  5. Effects of intra-abdominal pressure on adrenal gland function and morphology in rats

    PubMed Central

    Akkapulu, Nezih; Tirnaksiz, Mehmet Bulent; Kulac, Ibrahim; Tezel, Gaye Guler; Hayran, Mutlu; Dogrul, Ahmet Bulent; Cetinkaya, Erdinc; Yorganci, Kaya

    2015-01-01

    Intra-abdominal hypertension and abdominal compartment syndrome (IAH/ACS) are life-threatening conditions and caused by several clinical status. Although there is insufficient data regarding its effects on adrenal glands. This study aimed to identify whether elevated intra-abdominal pressure (IAP) caused any alteration on the morphology and function of adrenal glands in a rat model. Twenty four Sprague-Dawley male rats were included in the study. Animals were allocated into 4 groups. IAP was elevated to 15 mmHg for one hour and four hours in group 2 and 4. Group 1 and 3 were sham groups. Blood samples were taken for the assessment of plasma adrenaline, noradrenaline, and corticosterone levels and adrenalectomies were performed to evaluate apoptosis. Blood adrenaline, noradrenaline and corticosterone levels were significantly higher in the study groups compared with the sham groups. However, there were no significant changes in apoptotic index scores in the study groups as compared to sham groups. These results support that increased IAH leads to discharge of catecholamine and corticosterone from the adrenal glands. Failure to demonstrate similar changes in apoptotic index score may be concluded as apoptosis is not a leading pathway for impairment of adrenal glands during IAH period. PMID:26045846

  6. Growth hormone (GH) and atherosclerosis: changes in morphology and function of major arteries during GH treatment.

    PubMed

    Pfeifer, M; Verhovec, R; Zizek, B

    1999-04-01

    Patients with hypopituitarism have increased carotid artery intima-media thickness and reduced arterial distensibility. The effect of 2 years of growth hormone (GH) replacement therapy on these parameters was studied in 11 GH-deficient men (age range, 24-49 years) with hypopituitarism and compared with 12 healthy, age-matched men with no evidence of pituitary or vascular disease. Before treatment the intima-media of the common carotid arteries and the carotid bifurcations were significantly thicker in patients (P < 0.001) than in the control group. Treatment with GH normalized the intima-media thickness of the common carotid artery within 6 months and of the carotid bifurcation within 3 months. The changes in intima-media thickness of the carotid artery were negatively correlated with changes in serum levels of insulin-like growth factor I during treatment. There was a significant improvement in flow-mediated, endothelium-dependent dilation of the brachial artery at 3 months, which was sustained at 6, 18 and 24 months of GH treatment (P < 0.05). Thus, GH replacement therapy in GH-deficient men reverses early morphological and functional atherosclerotic changes in major arteries, and may reduce rates of vascular morbidity and mortality.

  7. Functional and morphological adaptations to aging in knee extensor muscles of physically active men.

    PubMed

    Baroni, Bruno Manfredini; Geremia, Jeam Marcel; Rodrigues, Rodrigo; Borges, Marcelo Krás; Jinha, Azim; Herzog, Walter; Vaz, Marco Aurélio

    2013-10-01

    It is not known if a physically active lifestyle, without systematic training, is sufficient to combat age-related muscle and strength loss. Therefore, the purpose of this study was to evaluate if the maintenance of a physically active lifestyle prevents muscle impairments due to aging. To address this issue, we evaluated 33 healthy men with similar physical activity levels (IPAQ = 2) across a large range of ages. Functional (torque-angle and torque-velocity relations) and morphological (vastus lateralis muscle architecture) properties of the knee extensor muscles were assessed and compared between three age groups: young adults (30 ± 6 y), middle-aged subjects (50 ± 7 y) and elderly subjects (69 ± 5 y). Isometric peak torques were significantly lower (30% to 36%) in elderly group subjects compared with the young adults. Concentric peak torques were significantly lower in the middle aged (18% to 32%) and elderly group (40% to 53%) compared with the young adults. Vastus lateralis thickness and fascicles lengths were significantly smaller in the elderly group subjects (15.8 ± 3.9 mm; 99.1 ± 25.8 mm) compared with the young adults (19.8 ± 3.6 mm; 152.1 ± 42.0 mm). These findings suggest that a physically active lifestyle, without systematic training, is not sufficient to avoid loss of strength and muscle mass with aging.

  8. Morphology, performance, fitness: functional insight into a post-Pleistocene radiation of mosquitofish

    PubMed Central

    Langerhans, R. Brian

    2009-01-01

    Bahamas mosquitofish (Gambusia hubbsi) colonized blue holes during the past approximately 15 000 years and exhibit relatively larger caudal regions in blue holes that contain piscivorous fish. It is hypothesized that larger caudal regions enhance fast-start escape performance and thus reflect an adaptation for avoiding predation. Here I test this hypothesis using a three-pronged, experimental approach. First, G. hubbsi from blue holes with predators were found to possess both greater fast-start performance and greater survivorship in the presence of predatory fish. Second, using individual-level data to investigate the morphology–performance–fitness pathway, I found that (i) fish with larger caudal regions produced higher fast-start performance and (ii) fish with higher fast-start performance enjoyed greater survivorship in the presence of fish predators—trends consistently observed across both predator regimes. Finally, I found that morphological divergence between predator regimes at least partially reflects genetic differentiation, as differences were retained in fish raised in a common laboratory environment. These results suggest that natural selection favours increased fast-start performance in the presence of piscivorous fish, consequently driving the evolution of larger caudal regions. Combined with previous work, this provides functional insight into body shape divergence and ecological speciation among Bahamian blue holes. PMID:19411270

  9. Studies of light scattering and morphologies of phase-separated polymer/nanoparticle mixtures

    NASA Astrophysics Data System (ADS)

    Ding, Xuan

    Nowadays, solid "filler" particles can be found in many manufactured polymeric materials because of the enhanced thermal and mechanical properties these particles can offer. However, the influence of the "filler" particles, especially those with size on a nanoscopic scale, on the structural evolution of multicomponent systems, is still poorly understood. In this thesis, the spinodal decomposition (SD) of polystyrene/poly(vinyl methyl ether) (PS/PVME) polymer blend system mixed with different nanoparticles have been investigated by the small angle light scattering (SALS) technique. Interpreting the data using the Cahn-Hilliard linear theory and the scaling theory on early stage and late stage, respectively, we concluded that the addition of nanoparticles into the pure polymer blends can cause a retardation of the phase separation. Furthermore, experiments on polystyrene/poly(2-vinyl pyridine) (PS/P2VP) polymer blends mixed with polystyrene-covered gold nanoparticles (Au-PS) have shown that during the spinodal decomposition these Au-PS nanoparticles can self-assemble at the continuous PS/P2VP interface, due to the tendency to reduce interfacial energy, making it possible to create the so-called "bijel" structure (bicontinuous interfacially jammed emulsion jel). We believe that the "bijel" structures have a huge potential of being used in areas such as photovoltaics and catalysis, because of their large surface areas.

  10. Form follows function: astrocyte morphology and immune dysfunction in SIV neuroAIDS.

    PubMed

    Lee, Kim M; Chiu, Kevin B; Renner, Nicole A; Sansing, Hope A; Didier, Peter J; MacLean, Andrew G

    2014-10-01

    Cortical function is disrupted in neuroinflammatory disorders, including HIV-associated neurocognitive disorders (HAND). Astrocyte dysfunction includes retraction of foot processes from the blood-brain barrier and decreased removal of neurotransmitters from synaptic clefts. Mechanisms of astrocyte activation, including innate immune function and the fine neuroanatomy of astrocytes, however, remain to be investigated. We quantified the number of glial fibrillary acidic protein (GFAP)-labeled astrocytes per square millimeter and the proportion of astrocytes immunopositive for Toll-like receptor 2 (TLR2) to examine innate immune activation in astrocytes. We also performed detailed morphometric analyses of gray and white matter astrocytes in the frontal and parietal lobes of rhesus macaques infected with simian immunodeficiency virus (SIV), both with and without encephalitis, an established model of AIDS neuropathogenesis. Protoplasmic astrocytes (gray matter) and fibrous astrocytes (deep white matter) were imaged, and morphometric features were analyzed using Neurolucida. Gray matter and white matter astrocytes showed no change in cell body size in animals infected with SIV regardless of encephalitic status. In SIV-infected macaques, both gray and white matter astrocytes had shorter, less ramified processes, resulting in decreased cell arbor compared with controls. SIV-infected macaques with encephalitis showed decreases in arbor length in white matter astrocytes and reduced complexity in gray matter astrocytes compared to controls. These results provide the first evidence that innate immune activation of astrocytes is linked to altered cortical astrocyte morphology in SIV/HIV infection. Here, we demonstrate that astrocyte remodeling is correlated with infection. Perturbed neuron-glia signaling may be a driving factor in the development of HAND.

  11. Morphologic and functional evaluation of the endothelium of transplanted human corneas.

    PubMed Central

    Bourne, W M

    1983-01-01

    This thesis contains the results of morphologic and functional studies of the endothelium of 253 consecutive penetrating corneal transplants. After keratoplasty, cells were lost from the central grafts at a rate of over 20% per year for approximately 3 years, after which the loss was minimal. Donor corneas preserved in organ culture had significantly more cell loss noted 2 months after keratoplasty than those preserved in M-K medium. The permeability of the grafted endothelium to fluorescein was significantly reduced in many cases; transplants with larger cells were less permeable. Transplanted corneas from older donors had more central endothelial cell loss and thicker corneas 2 months after keratoplasty than did those from younger donors. The central corneal thickness was less in phakic transplants than in aphakic grafts for 1 year after keratoplasty. After episodes of endothelial rejection had cleared, the affected grafts had lower cell densities and thicker corneas. To explain the results of studies of postoperative cell loss and endothelial permeability, two hypotheses were proposed: First, most endothelial cell damage occurs at the time of keratoplasty, with more cells lost from the peripheral graft and recipient cornea near the wound than from the central graft. Cells are "lost" from the central graft as they gradually move toward peripheral areas with larger cells; this slow process of cellular realignment, during which endothelial function is essentially normal, lasts for approximately 3 years. Second, as the cells in the central graft enlarge, the permeability of the central endothelium to fluorescein tends to decrease in proportion to the decrease in intercellular space adjacent to the anterior chamber. Images FIGURE 1 FIGURE 3 FIGURE 4 A FIGURE 4 B FIGURE 5 A FIGURE 5 B FIGURE 8 PMID:6375089

  12. Androgens Exert a Cysticidal Effect upon Taenia crassiceps by Disrupting Flame Cell Morphology and Function

    PubMed Central

    Ambrosio, Javier R.; Valverde-Islas, Laura; Nava-Castro, Karen E.; Palacios- Arreola, M. Isabel; Ostoa-Saloma, Pedro; Reynoso-Ducoing, Olivia; Escobedo, Galileo; Ruíz-Rosado, Azucena; Dominguez-Ramírez, Lenin; Morales-Montor, Jorge

    2015-01-01

    The effects of testosterone (T4) and dihydrotestosterone (DHT) on the survival of the helminth cestode parasite Taenia crassiceps, as well as their effects on actin, tubulin and myosin expression and their assembly into the excretory system of flame cells are described in this paper. In vitro evaluations on parasite viability, flow cytometry, confocal microscopy, video-microscopy of live flame cells, and docking experiments of androgens interacting with actin, tubulin, and myosin were conducted. Our results show that T4 and DHT reduce T. crassiceps viability in a dose- and time-dependent fashion, reaching 90% of mortality at the highest dose used (40 ng/ml) and time exposed (10 days) in culture. Androgen treatment does not induce differences in the specific expression pattern of actin, tubulin, and myosin isoforms as compared with control parasites. Confocal microscopy demonstrated a strong disruption of the parasite tegument, with reduced assembly, shape, and motion of flame cells. Docking experiments show that androgens are capable of affecting parasite survival and flame cell morphology by directly interacting with actin, tubulin and myosin without altering their protein expression pattern. We show that both T4 and DHT are able to bind actin, tubulin, and myosin affecting their assembly and causing parasite intoxication due to impairment of flame cell function. Live flame cell video microscopy showing a reduced motion as well changes in the shape of flame cells are also shown. In summary, T4 and DHT directly act on T. crassiceps cysticerci through altering parasite survival as well as the assembly and function of flame cells. PMID:26076446

  13. Androgens Exert a Cysticidal Effect upon Taenia crassiceps by Disrupting Flame Cell Morphology and Function.

    PubMed

    Ambrosio, Javier R; Valverde-Islas, Laura; Nava-Castro, Karen E; Palacios-Arreola, M Isabel; Ostoa-Saloma, Pedro; Reynoso-Ducoing, Olivia; Escobedo, Galileo; Ruíz-Rosado, Azucena; Dominguez-Ramírez, Lenin; Morales-Montor, Jorge

    2015-01-01

    The effects of testosterone (T4) and dihydrotestosterone (DHT) on the survival of the helminth cestode parasite Taenia crassiceps, as well as their effects on actin, tubulin and myosin expression and their assembly into the excretory system of flame cells are described in this paper. In vitro evaluations on parasite viability, flow cytometry, confocal microscopy, video-microscopy of live flame cells, and docking experiments of androgens interacting with actin, tubulin, and myosin were conducted. Our results show that T4 and DHT reduce T. crassiceps viability in a dose- and time-dependent fashion, reaching 90% of mortality at the highest dose used (40 ng/ml) and time exposed (10 days) in culture. Androgen treatment does not induce differences in the specific expression pattern of actin, tubulin, and myosin isoforms as compared with control parasites. Confocal microscopy demonstrated a strong disruption of the parasite tegument, with reduced assembly, shape, and motion of flame cells. Docking experiments show that androgens are capable of affecting parasite survival and flame cell morphology by directly interacting with actin, tubulin and myosin without altering their protein expression pattern. We show that both T4 and DHT are able to bind actin, tubulin, and myosin affecting their assembly and causing parasite intoxication due to impairment of flame cell function. Live flame cell video microscopy showing a reduced motion as well changes in the shape of flame cells are also shown. In summary, T4 and DHT directly act on T. crassiceps cysticerci through altering parasite survival as well as the assembly and function of flame cells.

  14. Comparison of otoacoustic emissions within gecko subfamilies: morphological implications for auditory function in lizards.

    PubMed

    Bergevin, Christopher

    2011-04-01

    Otoacoustic emissions (OAEs) are sounds emitted by the ear and provide a non-invasive probe into mechanisms underlying peripheral auditory transduction. This study focuses upon a comparison of emission properties in two phylogenetically similar pairs of gecko: Gekko gecko and Hemidactylus turcicus and Eublepharis macularius and Coleonyx variegatus. Each pair consists of two closely related species within the same subfamily, with quantitatively known morphological properties at the level of the auditory sensory organ (basilar papilla) in the inner ear. Essentially, the comparison boils down to an issue of size: how does overall body size, as well as the inner-ear dimensions (e.g., papilla length and number of hair cells), affect peripheral auditory function as inferred from OAEs? Estimates of frequency selectivity derived from stimulus-frequency emissions (emissions evoked by a single low-level tone) indicate that tuning is broader in the species with fewer hair cells/shorter papilla. Furthermore, emissions extend outwards to higher frequencies (for similar body temperatures) in the species with the smaller body size/narrower interaural spacing. This observation suggests the smaller species have relatively improved high-frequency sensitivity, possibly related to vocalizations and/or aiding azimuthal sound localization. For one species (Eublepharis), emissions were also examined in both juveniles and adults. Qualitatively similar emission properties in both suggests that inner-ear function is adult like soon after hatching and that external body size (e.g., middle-ear dimensions and interaural spacing) has a relatively small impact upon emission properties within a species.

  15. THE OBSERVABLE PRESTELLAR PHASE OF THE INITIAL MASS FUNCTION

    SciTech Connect

    Padoan, Paolo; Nordlund, Ake E-mail: aake@nbi.dk

    2011-11-15

    The observed similarities between the mass function of prestellar cores (CMF) and the stellar initial mass function (IMF) have led to the suggestion that the IMF is already largely determined in the gas phase. However, theoretical arguments show that the CMF may differ significantly from the IMF. In this Letter, we study the relation between the CMF and the IMF, as predicted by the IMF model of Padoan and Nordlund. We show that (1) the observed mass of prestellar cores is on average a few times smaller than that of the stellar systems they generate; (2) the CMF rises monotonically with decreasing mass, with a noticeable change in slope at approximately 3-5 M{sub Sun }, depending on mean density; (3) the selection of cores with masses larger than half their Bonnor-Ebert mass yields a CMF approximately consistent with the system IMF, rescaled in mass by the same factor as our model IMF, and therefore suitable to estimate the local efficiency of star formation, and to study the dependence of the IMF peak on cloud properties; and (4) only one in five pre-brown-dwarf core candidates is a true progenitor to a brown dwarf.

  16. Protective effect of intrarenal calcium membrane blockers before or after renal ischemia. Functional, morphological, and mitochondrial studies.

    PubMed Central

    Burke, T J; Arnold, P E; Gordon, J A; Bulger, R E; Dobyan, D C; Schrier, R W

    1984-01-01

    The present study examined whether a pre- or postischemic infusion of verapamil (V) or a postischemic infusion of nifedipine (N), drugs which block calcium (Ca++) influx across plasma membranes, provides protection against ischemic acute renal failure (ARF) in dogs. Renal hemodynamics and excretory function were examined 1 h (initiation phase) and 24 h (maintenance phase) after a 40-min intrarenal infusion of norepinephrine (NE). In each case, the uninfused contralateral kidney served as control. Four groups were studied: (a) dogs receiving NE alone; (b) dogs receiving an intrarenal infusion of V for 30 min before NE (V + NE); (c) dogs in which intrarenal V was infused for 2 h, beginning immediately after completion of NE infusion (NE + V); and (d) dogs in which intrarenal N was infused for 2 h, beginning immediately after completion of NE infusion (NE + N). Glomerular filtration rate (GFR) in the NE kidneys, as assessed by inulin clearance, at 1 and 24 h averaged 2.4 +/- 1.1 and 5.0 +/- 2.0 ml/min, respectively, as compared with control kidney GFRs of 28.0 +/- 3.5 and 43.8 +/- 5.0 ml/min, respectively (both at least P less than 0.01). In the V + NE group, GFR at 1 and 24 h averaged 15.0 +/- 5.5 and 31.0 +/- 4.5 ml/min, respectively, both at least P less than 0.05 as compared with values from NE kidneys. GFRs in the NE + V group averaged 15.0 +/- 2.4 and 16.3 +/- 3.6 ml/min at 1 and 24 h, both at least P less than 0.02 as compared with values from NE kidneys. GFR in the NE + N group averaged 18.6 +/- 6.0 ml/min at 24 h (P less than 0.05 as compared with GFRs in the NE kidneys). In addition, function of cortical mitochondria (Mito) was examined at the end of the 40-min NE infusion and after 1 and 24 h of reperfusion in the NE alone and NE + V groups. Mito respiration, assessed by acceptor control ratios, was reduced at each period in the NE alone kidneys. After 24 h, these Mito had accumulated Ca++ and exhibited reduced Ca++ uptake and increased Ca++ release rates

  17. Using Lambert W function and error function to model phase change on microfluidics

    NASA Astrophysics Data System (ADS)

    Bermudez Garcia, Anderson

    2014-05-01

    Solidification and melting modeling on microfluidics are solved using Lambert W's function and error's functions. Models are formulated using the heat's diffusion equation. The generic posed case is the melting of a slab with time dependent surface temperature, having a micro or nano-fluid liquid phase. At the beginning the solid slab is at melting temperature. A slab's face is put and maintained at temperature greater than the melting limit and varying in time. Lambert W function and error function are applied via Maple to obtain the analytic solution evolution of the front of microfluidic-solid interface, it is analytically computed and slab's corresponding melting time is determined. It is expected to have analytical results to be useful for food engineering, cooking engineering, pharmaceutical engineering, nano-engineering and bio-medical engineering.

  18. A functional monomer is not enough: principal component analysis of the influence of template complexation in pre-polymerization mixtures on imprinted polymer recognition and morphology.

    PubMed

    Golker, Kerstin; Karlsson, Björn C G; Rosengren, Annika M; Nicholls, Ian A

    2014-11-10

    In this report, principal component analysis (PCA) has been used to explore the influence of template complexation in the pre-polymerization phase on template molecularly imprinted polymer (MIP) recognition and polymer morphology. A series of 16 bupivacaine MIPs were studied. The ethylene glycol dimethacrylate (EGDMA)-crosslinked polymers had either methacrylic acid (MAA) or methyl methacrylate (MMA) as the functional monomer, and the stoichiometry between template, functional monomer and crosslinker was varied. The polymers were characterized using radioligand equilibrium binding experiments, gas sorption measurements, swelling studies and data extracted from molecular dynamics (MD) simulations of all-component pre-polymerization mixtures. The molar fraction of the functional monomer in the MAA-polymers contributed to describing both the binding, surface area and pore volume. Interestingly, weak positive correlations between the swelling behavior and the rebinding characteristics of the MAA-MIPs were exposed. Polymers prepared with MMA as a functional monomer and a polymer prepared with only EGDMA were found to share the same characteristics, such as poor rebinding capacities, as well as similar surface area and pore volume, independent of the molar fraction MMA used in synthesis. The use of PCA for interpreting relationships between MD-derived descriptions of events in the pre-polymerization mixture, recognition properties and morphologies of the corresponding polymers illustrates the potential of PCA as a tool for better understanding these complex materials and for their rational design.

  19. Crystalline Morphology and Polymorphic Phase Transitions in Electrospun Nylon 6 Nanofibers

    PubMed Central

    Liu, Yi; Cui, Li; Guan, Fangxiao; Gao, Yi; Hedin, Nyle E.; Zhu, Lei; Fong, Hao

    2008-01-01

    Uniform nylon 6 nanofibers with diameters around 200 nm were prepared by electrospinning. Polymorphic phase transitions and crystal orientation of nylon 6 in unconfined (i.e., as-electrospun) and a high Tg (340 °C) polyimide confined nanofibers were studied. Similar to melt-spun nylon 6 fibers, electrospun nylon 6 nanofibers also exhibited predominant, meta-stable γ crystalline form, and the γ-crystal (chain) axes preferentially oriented parallel to the fiber axis. Upon annealing above 150 °C, γ-form crystals gradually melted and recrystallized into the thermodynamically stable α-form crystals, which ultimately melted at 220 °C. Release of surface tension accompanied this melt-recrystallization process, as revealed by differential scanning calorimetry. For confined nanofibers, both the melt-recrystallization and surface tension release processes were substantially depressed; γ-form crystals did not melt and recrystallize into α-form crystals until 210 °C, only 10 °C below the Tm at 220 °C. After complete melting of nano-confined crystals at 240 °C and recrystallization at 100 °C, only α-form crystals oriented perpendicular to the nanofiber axis were obtained. In the polyimide-confined nanofibers, the Brill transition (from the monoclinic α-form to a high temperature monoclinic form) was observed at 180–190 °C, which was at least 20 °C higher than that in unconfined nylon 6 at approximately 160 °C. This, again, was attributed to the confinement effect. PMID:18698379

  20. Dendritic Growth Morphologies in Al-Zn Alloys—Part II: Phase-Field Computations

    NASA Astrophysics Data System (ADS)

    Dantzig, J. A.; Di Napoli, Paolo; Friedli, J.; Rappaz, M.

    2013-12-01

    In Part I of this article, the role of the Zn content in the development of solidification microstructures in Al-Zn alloys was investigated experimentally using X-ray tomographic microscopy. The transition region between dendrites found at low Zn content and dendrites found at high Zn content was characterized by textured seaweed-type structures. This Dendrite Orientation Transition (DOT) was explained by the effect of the Zn content on the weak anisotropy of the solid-liquid interfacial energy of Al. In order to further support this interpretation and to elucidate the growth mechanisms of the complex structures that form in the DOT region, a detailed phase-field study exploring anisotropy parameters' space is presented in this paper. For equiaxed growth, our results essentially recapitulate those of Haxhimali et al.[1] in simulations for pure materials. We find distinct regions of the parameter space associated with and dendrites, separated by a region where hyperbranched dendrites are observed. In simulations of directional solidification, we find similar behavior at the extrema, but in this case, the anisotropy parameters corresponding to the hyperbranched region produce textured seaweeds. As noted in the experimental work reported in Part I, these structures are actually dendrites that prefer to grow misaligned with respect to the thermal gradient direction. We also show that in this region, the dendrites grow with a blunted tip that oscillates and splits, resulting in an oriented trunk that continuously emits side branches in other directions. We conclude by making a correlation between the alloy composition and surface energy anisotropy parameters.

  1. Follow-up study of functional and morphological malocclusion trait changes from 3 to 12 years of age.

    PubMed

    Ovsenik, Maja; Farcnik, Franc Marjan; Korpar, Majda; Verdenik, Ivan

    2007-10-01

    The aim of this study was to evaluate morphological and functional malocclusion trait changes in 3- to 12-year-old children and to determine whether such functional traits at the 3, 4, and 5 years of age correlated with malocclusion severity score at 12 years of age. Two hundred and sixty-seven children (132 boys, 135 girls) were randomly selected for a follow-up study from a previous cohort of 560 subjects. Functional and morphological traits were clinically assessed. Five functional malocclusion traits: mouth breathing, atypical swallowing, thumb, pacifier sucking, and bottle feeding were assessed and evaluated. Intra-arch assessment involved measurements of incisor crowding, rotation of incisors, and axial inclination of the teeth. For inter-arch measurements, overbite, anterior open bite, overjet, reverse overjet, anterior crossbite, and buccal segment relationships were recorded. The weighted sum of recorded occlusal traits thus represented the total malocclusion severity score. The median morphological malocclusion severity score was almost the same at 3 and 12 years of age, while functional malocclusion decreased. Sucking habits (finger- or dummy-sucking, bottle feeding) until 5 years of age were statistically significantly correlated with an atypical swallowing pattern from 6 to 9 years (Spearman r = 0.178, P = 0.017), which in turn was statistically significantly correlated with the morphological malocclusion severity score (Spearman r = 0.185, P = 0.042) at 12 years of age. At an early age, the morphological severity score is related to the stage of dental development, while at a later period, malocclusion severity score is also the result of incorrect orofacial functions at an early stage of dental development.

  2. Phase diagrams and morphological evolution in wrapping of rod-shaped elastic nanoparticles by cell membrane: A two-dimensional study

    NASA Astrophysics Data System (ADS)

    Yi, Xin; Gao, Huajian

    2014-06-01

    A fundamental understanding of cell-nanomaterial interaction is essential for biomedical diagnostics, therapeutics, and nanotoxicity. Here, we perform a theoretical analysis to investigate the phase diagram and morphological evolution of an elastic rod-shaped nanoparticle wrapped by a lipid membrane in two dimensions. We show that there exist five possible wrapping phases based on the stability of full wrapping, partial wrapping, and no wrapping states. The wrapping phases depend on the shape and size of the particle, adhesion energy, membrane tension, and bending rigidity ratio between the particle and membrane. While symmetric morphologies are observed in the early and late stages of wrapping, in between a soft rod-shaped nanoparticle undergoes a dramatic symmetry breaking morphological change while stiff and rigid nanoparticles experience a sharp reorientation. These results are of interest to the study of a range of phenomena including viral budding, exocytosis, as well as endocytosis or phagocytosis of elastic particles into cells.

  3. Recovering refractive index correlation function from measurement of tissue scattering phase function (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Rogers, Jeremy D.

    2016-03-01

    Numerous methods have been developed to quantify the light scattering properties of tissue. These properties are of interest in diagnostic and screening applications due to sensitivity to changes in tissue ultrastructure and changes associated with disease such as cancer. Tissue is considered a weak scatterer because that the mean free path is much larger than the correlation length. When this is the case, all scattering properties can be calculated from the refractive index correlation function Bn(r). Direct measurement of Bn(r) is challenging because it requires refractive index measurement at high resolution over a large tissue volume. Instead, a model is usually assumed. One particularly useful model, the Whittle-Matern function includes several realistic function types such as mass fractal and exponential. Optical scattering properties for weakly scattering media can be determined analytically from Bn(r) by applying the Rayleigh-Gans-Debye (RGD) or Born Approximation, and so measured scattering properties are used to fit parameters of the model function. Direct measurement of Bn(r) would provide confirmation that the function is a good representation of tissue or help in identifying the length scale at which changes occur. The RGD approximation relates the scattering phase function to the refractive index correlation function through a Fourier transform. This can be inverted without approximation, so goniometric measurement of the scattering can be converted to Bn(r). However, geometric constraints of the measurement of the phase function, angular resolution, and wavelength result in a band limited measurement of Bn(r). These limits are discussed and example measurements are described.

  4. Role of nanoparticles in phase separation and final morphology of superhydrophobic polypropylene/zinc oxide nanocomposite surfaces

    NASA Astrophysics Data System (ADS)

    Hejazi, Iman; Hajalizadeh, Bardia; Seyfi, Javad; Sadeghi, Gity Mir Mohamad; Jafari, Seyed-Hassan; Khonakdar, Hossein Ali

    2014-02-01

    In this work, phase separation process was revisited to study the effect of nanoparticles in acceleration of phase separation and formation of hierarchical structures. Superhydrophobic surfaces were prepared using polypropylene (PP) and the corresponding nanocomposites containing zinc oxide (ZnO) nanoparticles through a typical solution casting method. The wettability and morphological behavior of the surfaces were investigated via water contact angle (WCA) measurements and scanning electron microscopy (SEM), respectively. It was found that upon introduction of ZnO nanoparticles into the pure PP, the obtained surfaces have become superhydrophobic with WCAs above 150° and sliding angles below 10°. Calcination of ZnO nanoparticles was exploited to explicate the unexpected significant loss in superhydrophobicity of the sample loaded with high ZnO content. Crystallization behavior of the samples were also investigated via differential scanning calorimetry and correlated to superhydrophobicity of the surfaces. X-ray photoelectron and Fourier transform infrared spectroscopies were also utilized to further characterize the samples. An attempt was also made to present a more clear mechanism for formation of hierarchical structures which are responsible for superhydrophobicity. Likewise, the so far proposed mechanisms for formation of micro/nano roughness on the superhydrophobic surfaces were reviewed as well.

  5. Phase-specific responses to different qualities of food in the desert locust, Schistocerca gregaria: developmental, morphological and reproductive characteristics.

    PubMed

    Maeno, Koutaro; Tanaka, Seiji

    2011-04-01

    Solitarious female adults are known to produce smaller hatchlings than those produced by gregarious adults of the desert locust, Schistocerca gregaria. This study investigated developmental, morphological and reproductive responses to different qualities of food in hatchlings of different phases. Mortality was higher, the duration of nymphal development longer and adult body weight lighter with a low-quality food than a high-quality food. Gregarious hatchlings showed better survivorship, grew faster and became larger adults than did solitarious ones. The incidence of locusts exhibiting extra molting, which was typically observed in the solitarious phase, was dramatically increased when a low-quality food was given to the solitarious hatchlings. Low-quality food caused locusts to shift morphometric ratios toward the values typical of gregarious forms; smaller F/C (hind femur length/maximum head width) and larger E/F (elytra length/hind femur length). Solitarious hatchlings grown at either high- or low-quality foods and then given high-quality food after adult emergence revealed that food qualities during the nymphal stage influence their progeny quality and quantity via adult body size that influenced reproductive performance. Female adults showed an overshooting response to a shift from low- to high-quality food by increasing egg production that was specific to body size. This study may suggest that gregarious hatchlings are better adapted to adverse food conditions than solitarious counterparts and extra molting is induced even among gregarious hatchlings under poor food conditions.

  6. Influences of structural mismatch on morphology, phase transition temperature, segmental dynamics and color-transition behaviors of polydiacetylene vesicles.

    PubMed

    Pattanatornchai, Thanutpon; Charoenthai, Nipaphat; Traiphol, Rakchart

    2014-10-15

    In this contribution, we report a systematic study of polydiacetylene (PDA) vesicles fabricated by mixing two types of monomers, 10,12-tricosadiynoic acid (TCDA) and 10,12-pentacosadiynoic acid (PCDA). These diacetylene (DA) monomers constitute the same head group but different alkyl chain length, which in turn causes structural mismatch within the PDA layers. The PCDA:TCDA ratios are 100, 75, 50, 25 and 0mol%. Morphologies and properties of these PDA vesicles are explored by utilizing laser light scattering, transmission electron microscopy, differential scanning calorimetry, temperature-dependent nuclear magnetic resonance spectroscopy (NMR) and spin-lattice relaxation time (T1) measurements. An increase in DA mole ratio to 50mol% leads to significant increase in particle size. The mixed PDA vesicles also exhibit irregular shape with rather rough surface. The mismatch of alkyl side chain causes the drop of phase transition temperature. For the system of mixed poly(PCDA50:TCDA50), its transition temperature is lower than those of the pure PDAs. The NMR line shape analysis detects an abrupt change of proton signal adjacent to the PDA head group during the blue/red color-transition process. The T1 measurements also reveal different local environments of PDA alkyl side chains in the blue and red phases. The mismatch of PDA side chains causes significant drop of the color-transition temperature.

  7. Parallel phase-shifting digital holography with adaptive function using phase-mode spatial light modulator.

    PubMed

    Lin, Miao; Nitta, Kouichi; Matoba, Osamu; Awatsuji, Yasuhiro

    2012-05-10

    Parallel phase-shifting digital holography using a phase-mode spatial light modulator (SLM) is proposed. The phase-mode SLM implements spatial distribution of phase retardation required in the parallel phase-shifting digital holography. This SLM can also compensate dynamically the phase distortion caused by optical elements such as beam splitters, lenses, and air fluctuation. Experimental demonstration using a static object is presented.

  8. Morphology and phase behavior of ethanol nanodrops condensed on chemically patterned surfaces.

    PubMed

    Checco, Antonio; Ocko, Benjamin M

    2008-06-01

    Equilibrium wetting of ethanol onto chemically patterned nanostripes has been investigated using environmental atomic force microscopy (AFM) in noncontact mode. The chemical patterns are composed of COOH-terminated "wetting" regions and CH3-terminated "nonwetting" regions. A specially designed environmental AFM chamber allowed for accurate measurements of droplet height as a function of the temperature offset between the substrate and a macroscopic ethanol reservoir. At saturation, the height dependence scales with droplet width according to w1/2, in excellent agreement with the augmented Young equation (AYE) modeled with dispersive, nonretarded surface potentials. At small under- and oversaturations, the AYE model accurately fits the data if an effective DeltaT is used as a fitting parameter. There is a systematic difference between the measured DeltaT and the values extracted from the fits to the data. In addition to static measurements, we present time-resolved measurements of the droplet height which enable the study of condensation-evaporation dynamics of nanometer-scale drops.

  9. Quantification of the morphological transition in cadmium selenide nanocrystals as a function of reaction temperature

    NASA Astrophysics Data System (ADS)

    Cameron, Michael Tanner; Rogerson, Jordan A.; Blom, Douglas A.; Dukes, Albert D.

    2016-03-01

    Controlling the morphology of semiconductor nanocrystals has typically relied on controlling the concentration and species of surface ligands utilized in synthesis. Specific shapes, such as branched structures are of particular interest as the light harvesting and charge separating layer in a photovoltaic device. In this work we quantify how changes in the reaction temperature affect the resulting morphology of the nanocrystals. The narrowness of the temperature range over which the morphological transition occurred provides guidance to the tolerances necessary in the synthesis of CdSe utilized in commercial devices on a large scale.

  10. Morphologic and functional effects of gamma secretase inhibition on splenic marginal zone B cells.

    PubMed

    de Vera Mudry, Maria Cristina; Regenass-Lechner, Franziska; Ozmen, Laurence; Altmann, Bernd; Festag, Matthias; Singer, Thomas; Müller, Lutz; Jacobsen, Helmut; Flohr, Alexander

    2012-01-01

    The γ-secretase complex is a promising target in Alzheimer's disease because of its role in the amyloidogenic processing of β-amyloid precursor protein. This enzyme also catalyzes the cleavage of Notch receptor, resulting in the nuclear translocation of intracellular Notch where it modulates gene transcription. Notch signaling is essential in cell fate decisions during embryogenesis, neuronal differentiation, hematopoiesis, and development of T and B cells, including splenic marginal zone (MZ) B cells. This B cell compartment participates in the early phases of the immune response to blood-borne bacteria and viruses. Chronic treatment with the oral γ-secretase inhibitor RO4929097 resulted in dose-dependent decreased cellularity (atrophy) of the MZ of rats and mice. Significant decreases in relative MZ B-cell numbers of RO4929097-treated animals were confirmed by flow cytometry. Numbers of MZ B cells reverted to normal after a sufficient RO4929097-free recovery period. Functional characterization of the immune response in relation to RO4929097-related MZ B cell decrease was assessed in mice vaccinated with inactivated vesicular stomatitis virus (VSV). Compared with the immunosuppressant cyclosporin A, RO4929097 caused only mild and reversible delayed early neutralizing IgM and IgG responses to VSV. Thus, the functional consequence of MZ B cell decrease on host defense is comparatively mild.

  11. Effects of post-reactor functionalization on the phase behaviour of an ethylene-1-octene copolymer studied using solid-state high resolution 13C NMR spectroscopy.

    PubMed

    Calucci, Lucia; Cicogna, Francesca; Forte, Claudia

    2013-10-07

    The effects of post-reactor functionalization with naphthoate-TEMPO on the structure and morphology of an ethylene-1-octene copolymer were investigated by means of solid-state NMR techniques and DSC measurements. Selective (13)C MAS experiments allowed the orthorhombic and the monoclinic crystalline phases and two amorphous phases with different degree of mobility to be detected and quantified. (13)C and (1)H relaxation time measurements and spin diffusion experiments gave insight into the polymer dynamics within the different phases, the crystalline domain dimensions, and the rate of chain diffusion between amorphous and crystalline phases. Comparison of the results obtained for the pristine copolymer and the functionalized samples clearly indicated that the functionalization procedure causes redistribution within the crystalline and the amorphous phases with no relevant change in the degree of crystallinity or in the crystalline domain average size, and slows down chain diffusion.

  12. Elephant brain. Part I: gross morphology, functions, comparative anatomy, and evolution.

    PubMed

    Shoshani, Jeheskel; Kupsky, William J; Marchant, Gary H

    2006-06-30

    We report morphological data on brains of four African, Loxodonta africana, and three Asian elephants, Elephas maximus, and compare findings to literature. Brains exhibit a gyral pattern more complex and with more numerous gyri than in primates, humans included, and in carnivores, but less complex than in cetaceans. Cerebral frontal, parietal, temporal, limbic, and insular lobes are well developed, whereas the occipital lobe is relatively small. The insula is not as opercularized as in man. The temporal lobe is disproportionately large and expands laterally. Humans and elephants have three parallel temporal gyri: superior, middle, and inferior. Hippocampal sizes in elephants and humans are comparable, but proportionally smaller in elephant. A possible carotid rete was observed at the base of the brain. Brain size appears to be related to body size, ecology, sociality, and longevity. Elephant adult brain averages 4783 g, the largest among living and extinct terrestrial mammals; elephant neonate brain averages 50% of its adult brain weight (25% in humans). Cerebellar weight averages 18.6% of brain (1.8 times larger than in humans). During evolution, encephalization quotient has increased by 10-fold (0.2 for extinct Moeritherium, approximately 2.0 for extant elephants). We present 20 figures of the elephant brain, 16 of which contain new material. Similarities between human and elephant brains could be due to convergent evolution; both display mosaic characters and are highly derived mammals. Humans and elephants use and make tools and show a range of complex learning skills and behaviors. In elephants, the large amount of cerebral cortex, especially in the temporal lobe, and the well-developed olfactory system, structures associated with complex learning and behavioral functions in humans, may provide the substrate for such complex skills and behavior.

  13. Protrudin regulates endoplasmic reticulum morphology and function associated with the pathogenesis of hereditary spastic paraplegia.

    PubMed

    Hashimoto, Yutaka; Shirane, Michiko; Matsuzaki, Fumiko; Saita, Shotaro; Ohnishi, Takafumi; Nakayama, Keiichi I

    2014-05-09

    Protrudin is a membrane protein that regulates polarized vesicular trafficking in neurons. The protrudin gene (ZFYVE27) is mutated in a subset of individuals with hereditary spastic paraplegia (HSP), and protrudin is therefore also referred to as spastic paraplegia (SPG) 33. We have now generated mice that express a transgene for dual epitope-tagged protrudin under control of a neuron-specific promoter, and we have subjected highly purified protrudin-containing complexes isolated from the brain of these mice to proteomics analysis to identify proteins that associate with protrudin. Protrudin was found to interact with other HSP-related proteins including myelin proteolipid protein 1 (SPG2), atlastin-1 (SPG3A), REEP1 (SPG31), REEP5 (similar to REEP1), Kif5A (SPG10), Kif5B, Kif5C, and reticulon 1, 3, and 4 (similar to reticulon 2, SPG12). Membrane topology analysis indicated that one of three hydrophobic segments of protrudin forms a hydrophobic hairpin domain similar to those of other SPG proteins. Protrudin was found to localize predominantly to the tubular endoplasmic reticulum (ER), and forced expression of protrudin promoted the formation and stabilization of the tubular ER network. The protrudin(G191V) mutant, which has been identified in a subset of HSP patients, manifested an increased intracellular stability, and cells expressing this mutant showed an increased susceptibility to ER stress. Our results thus suggest that protrudin contributes to the regulation of ER morphology and function, and that its deregulation by mutation is a causative defect in HSP.

  14. Crossed cerebellar diaschisis in acute ischemic stroke: Impact on morphologic and functional outcome.

    PubMed

    Kunz, Wolfgang G; Sommer, Wieland H; Höhne, Christopher; Fabritius, Matthias P; Schuler, Felix; Dorn, Franziska; Othman, Ahmed E; Meinel, Felix G; von Baumgarten, Louisa; Reiser, Maximilian F; Ertl-Wagner, Birgit; Thierfelder, Kolja M

    2017-01-01

    Crossed cerebellar diaschisis (CCD) is the phenomenon of hypoperfusion and hypometabolism of the contralateral cerebellar hemisphere caused by dysfunction of the related supratentorial region. Our aim was to analyze its influence on morphologic and functional outcome in acute ischemic stroke. Subjects with stroke caused by a large vessel occlusion of the anterior circulation were selected from an initial cohort of 1644 consecutive patients who underwent multiparametric CT including whole-brain CT perfusion. Two experienced readers evaluated the posterior fossa in terms of CCD absence (CCD-) or presence (CCD+). A total of 156 patients formed the study cohort with 102 patients (65.4%) categorized as CCD- and 54 (34.6%) as CCD+. In linear and logistic regression analyses, no significant association between CCD and final infarction volume (β = -0.440, p = 0.972), discharge mRS ≤ 2 (OR = 1.897, p = 0.320), or 90-day mRS ≤ 2 (OR = 0.531, p = 0.492) was detected. CCD+ patients had larger supratentorial cerebral blood flow deficits (median: 164 ml vs. 115 ml; p = 0.001) compared to CCD-patients. Regarding complications, CCD was associated with a higher rate of parenchymal hematomas (OR = 4.793, p = 0.035). In conclusion, CCD is frequently encountered in acute ischemic stroke caused by large vessel occlusion of the anterior circulation. CCD was associated with the occurrence of parenchymal hematoma in the ipsilateral cerebral infarction but did not prove to significantly influence patient outcome.

  15. Dry under water: comparative morphology and functional aspects of air-retaining insect surfaces.

    PubMed

    Balmert, Alexander; Florian Bohn, Holger; Ditsche-Kuru, Petra; Barthlott, Wilhelm

    2011-04-01

    Superhydrophobic surfaces prevent certain body parts of semiaquatic and aquatic insects from getting wet while submerged in water. The air layer on these surfaces can serve the insects as a physical gill. Using scanning electron microscopy, we investigated the morphology of air-retaining surfaces in five insect species with different levels of adaptation to aquatic habitats. We found surfaces with either large and sparse hairs (setae), small and dense hairs (microtrichia), or hierarchically structured surfaces with both types of hairs. The structural parameters and air-film persistence of these surfaces were compared. Air-film persistence varied between 2 days in the beetle Galerucella nymphaea possessing only sparse setae and more than 120 days in the bugs Notonecta glauca and Ilyocoris cimicoides possessing dense microtrichia (up to 6.6 × 10(6) microtrichia per millimeter square). From our results, we conclude that the density of the surface structures is the most important factor that affects the persistence of air films. Combinations of setae and microtrichia are not decisive for the overall persistence of the air film but might provide a thick air store for a short time and a thin but mechanically more stable air film for a long time. Thus, we assume that a dense cover of microtrichia acts as a "backup system" preventing wetting of the body surface in case the air-water interface is pressed toward the surface. Our findings might be beneficial for the development of biomimetic surfaces for long-term air retention and drag reduction under water. In addition, the biological functions of the different air retention capabilities are discussed.

  16. Functional morphology and kinematics of terrestrial feeding in the largescale foureyes (Anableps anableps).

    PubMed

    Michel, Krijn B; Aerts, Peter; Gibb, Alice C; Van Wassenbergh, Sam

    2015-09-01

    A major challenge for aquatic vertebrates that invade land is feeding in the terrestrial realm. The capacity of the gape to become parallel with the ground has been shown to be a key factor to allow fishes to feed on prey lying on a terrestrial surface. To do so, two strategies have been identified that involve a nose-down tilting of the head: (1) by pivoting on the pectoral fins as observed in mudskippers, and (2) curling of the anterior part of the body supported by a long and flexible eel-like body as shown in eel-catfish. Although Anableps anableps successfully feeds on land, it does not possess an eel-like body or pectoral fins to support or lift the anterior part of the body. We identified the mechanism of terrestrial prey capture in A. anableps by studying kinematics and functional morphology of the cranial structures, using high-speed video and graphical 3D reconstructions from computed tomography scans. In contrast to the previously described mechanisms, A. anableps relies solely on upper and lower jaw movement for re-orientation of the gape towards the ground. The premaxilla is protruded anteroventrally, and the lower jaw is depressed to a right angle with the substrate. Both the lower and upper jaws are selectively positioned onto the prey. Anableps anableps thereby uses the jaw protrusion mechanism previously described for other cyprinodontiforms to allow a continued protrusion of the premaxilla even while closing the jaws. Several structural adaptations appear to allow more controlled movements and increased amplitude of anterior and ventral protrusion of the upper jaw compared with other cyprinodontiforms.

  17. PMMA/PS coaxial electrospinning: core–shell fiber morphology as a function of material parameters

    NASA Astrophysics Data System (ADS)

    Rahmani, Shahrzad; Arefazar, Ahmad; Latifi, Masoud

    2017-03-01

    Core–shell fibers of polymethyl methacrylate (PMMA) and polystyrene (PS) have been successfully electrospun by coaxial electrospinning. To evaluate the influence of the solvent on the final fiber morphology, four types of organic solvents were used in the shell solution while the core solvent was preserved. Morphological observations with scanning electron microscopy, transmission electron microscopy and optical microscopy revealed that both core and shell solvent properties were involved in the final fiber morphology. To explain this involvement, alongside a discussion of the Bagley solubility graph of PS and PMMA, a novel criterion based on solvent physical properties was introduced. A theoretical model based on the momentum conservation principle was developed and applied for describing the dependence of the core and shell diameters to their solvent combinations. Different concentrations of core and shell were also investigated in the coaxial electrospinning of PMMA/PS. The core–shell fiber morphologies with different core and shell concentrations were compared with their single electrospun fibers.

  18. Early Functional and Morphologic Abnormalities in the Diabetic Nyxnob Mouse Retina

    PubMed Central

    Tarchick, Matthew J.; Bassiri, Parastoo; Rohwer, Rebecca M.; Samuels, Ivy S.

    2016-01-01

    Purpose The electroretinogram c-wave is generated by the summation of the positive polarity hyperpolarization of the apical RPE membrane and a negative polarity slow PIII response of Müller glia cells. Therefore, the c-wave reduction noted in prior studies of mouse models of diabetes could reflect a reduction in the RPE component or an increase in slow PIII. The present study used a genetic approach to distinguish between these two alternatives. Methods Nyxnob mice lack the ERG b-wave, revealing the early phase of slow PIII. To visualize changes in slow PIII due to diabetes, Nyxnob mice were given streptozotocin (STZ) injections to induce diabetes or received vehicle as a control. After 1, 2, and 4 weeks of sustained hyperglycemia (>250 mg/dL), standard strobe flash ERG and dc-ERG testing were conducted. Histological analysis of the retina was performed. Results A reduced c-wave was noted at the 1 week time point, and persisted at later time points. In comparison, slow PIII amplitudes were unaffected after 1 week of hyperglycemia, but were significantly reduced in STZ mice at the 2-week time point. The decrease in amplitude occurred before any identifiable decrease to the a-wave. At the later time point, the a-wave became involved, although the slow PIII reductions were more pronounced. Morphological abnormalities in the RPE, including increased thickness and altered melanosome distribution, were identified in diabetic animals. Conclusions Because the c-wave and slow PIII were both reduced, these results demonstrated that diabetes-induced reductions to the c-wave cannot be attributed to an early increase in the Müller glia-derived potassium conductance. Furthermore, because the a-wave, slow PIII and c-wave reductions were not equivalent, and varied in their onset, the reductions cannot reflect the same mechanism, such as a change in membrane resistance. The presence of small changes to RPE architecture indicate that the c-wave reductions present in diabetic mice

  19. Three-dimensional morphological imaging of human induced pluripotent stem cells by using low-coherence quantitative phase microscopy

    NASA Astrophysics Data System (ADS)

    Yamauchi, Toyohiko; Kakuno, Yumi; Goto, Kentaro; Fukami, Tadashi; Sugiyama, Norikazu; Iwai, Hidenao; Mizuguchi, Yoshinori; Yamashita, Yutaka

    2014-03-01

    There is an increasing need for non-invasive imaging techniques in the field of stem cell research. Label-free techniques are the best choice for assessment of stem cells because the cells remain intact after imaging and can be used for further studies such as differentiation induction. To develop a high-resolution label-free imaging system, we have been working on a low-coherence quantitative phase microscope (LC-QPM). LC-QPM is a Linnik-type interference microscope equipped with nanometer-resolution optical-path-length control and capable of obtaining three-dimensional volumetric images. The lateral and vertical resolutions of our system are respectively 0.5 and 0.93 μm and this performance allows capturing sub-cellular morphological features of live cells without labeling. Utilizing LC-QPM, we reported on three-dimensional imaging of membrane fluctuations, dynamics of filopodia, and motions of intracellular organelles. In this presentation, we report three-dimensional morphological imaging of human induced pluripotent stem cells (hiPS cells). Two groups of monolayer hiPS cell cultures were prepared so that one group was cultured in a suitable culture medium that kept the cells undifferentiated, and the other group was cultured in a medium supplemented with retinoic acid, which forces the stem cells to differentiate. The volumetric images of the 2 groups show distinctive differences, especially in surface roughness. We believe that our LC-QPM system will prove useful in assessing many other stem cell conditions.

  20. Fatigue crack propagation in dual-phase steels: Effects of ferritic-martensitic microstructures on crack path morphology

    NASA Astrophysics Data System (ADS)

    Dutta, V. B.; Suresh, S.; Ritchie, R. O.

    1984-06-01

    microstructures with maximum resistance to fatigue crack extension while maintaining high strength levels. A wide range of crack growth rates has been examined, from ~10-8 to 10-3 mm per cycle, in a series of duplex microstructures of comparable yield strength and prior austenite grain size where intercritical heat treatments were used to vary the proportion, morphology, and distribution of the ferrite and martensite phases. Results of fatigue crack propagation tests, conducted on “long cracks” in room temperature moist air environments, revealed a very large influence of microstructure over the entire spectrum of growth rates at low load ratios. Similar trends were observed at high load ratio, although the extent of the microstructural effects on crack growth behavior was significantly less marked. Specifically, microstructures containing fine globular or coarse martensite in a coarse-grained ferritic matrix demonstrated exceptionally high resistance to crack growth without loss in strength properties. To our knowledge, these microstructures yielded the highest ambient temperature fatigue threshold stress intensity range ΔK0 values reported to date, and certainly the highest combination of strength and ΔK0 for steels ( i.e., ΔK0 values above 19 MPa√m with yield strengths in excess of 600 MPa). Such unusually high crack growth resistance is attributed primarily to a tortuous morphology of crack path which results in a reduction in the crack driving force from crack deflection and roughness-induced crack closure mechanisms. Quantitative metallography and experimental crack closure measurements, applied to currently available analytical models for the deflection and closure processes, are presented to substantiate such interpretations.

  1. Structural, Morphological, and Functional Correlates of Corneal Endothelial Toxicity Following Corneal Exposure to Sulfur Mustard Vapor

    DTIC Science & Technology

    2013-10-01

    cells of regular shape and size, with interdigitated borders, apical microvilli, and infrequent cilia (Fig. 4A). Within 24 hours of exposure, all...Fig. 4B). Most CECs exhibited atypical apical membrane morphologies and lacked cell-to-cell interdigitations (Figs. 4B, 4C). In regions of CEC...endothelial monolayer with frequent microvilli and interdigitations at regions of cell–cell contact. (B–D) Characteristic morphologies observed 1 day after SM

  2. Bivariate mass-size relation as a function of morphology as determined by Galaxy Zoo 2 crowdsourced visual classifications

    NASA Astrophysics Data System (ADS)

    Beck, Melanie; Scarlata, Claudia; Fortson, Lucy; Willett, Kyle; Galloway, Melanie

    2016-01-01

    It is well known that the mass-size distribution evolves as a function of cosmic time and that this evolution is different between passive and star-forming galaxy populations. However, the devil is in the details and the precise evolution is still a matter of debate since this requires careful comparison between similar galaxy populations over cosmic time while simultaneously taking into account changes in image resolution, rest-frame wavelength, and surface brightness dimming in addition to properly selecting representative morphological samples.Here we present the first step in an ambitious undertaking to calculate the bivariate mass-size distribution as a function of time and morphology. We begin with a large sample (~3 x 105) of SDSS galaxies at z ~ 0.1. Morphologies for this sample have been determined by Galaxy Zoo crowdsourced visual classifications and we split the sample not only by disk- and bulge-dominated galaxies but also in finer morphology bins such as bulge strength. Bivariate distribution functions are the only way to properly account for biases and selection effects. In particular, we quantify the mass-size distribution with a version of the parametric Maximum Likelihood estimator which has been modified to account for measurement errors as well as upper limits on galaxy sizes.

  3. Preparation of nanoencapsulated phase change material as latent functionally thermal fluid

    NASA Astrophysics Data System (ADS)

    Fang, Yutang; Kuang, Shengyan; Gao, Xuenong; Zhang, Zhengguo

    2009-02-01

    Nanoencapsulated phase change material with polystyrene as the shell and n-octadecane as the core was synthesized using the ultrasonic technique and miniemulsion in situ polymerization. The influences of polymerization factors, including initiator, chain transfer agent (CTA), surfactant, n-octadecane/styrene ratio and hydrophilic co-monomer, on the morphology and thermophysical properties of nanocapsules were systematically investigated. The optimized polymerization conditions were 0.5 wt% of initiator (2,2-azobisisobutyronitrile), 0.4 wt% of CTA (n-dodecyl mercaptan), 2% of composite surfactants which were composed of sodium dodecyl sulfate and poly-(ethylene glycol) monooctylphenyl ether by 1 : 1 in weight ratio, 1 wt% of hydrophilic co-monomer butyl acrylate or 3 wt% of methyl methacrylate and 1 : 1 n-octadecane to styrene in weight ratio. Under these conditions, the z-average size of prepared nanocapsules was 124 nm and the phase change enthalpy was 124.4 kJ kg-1. The heat capacity was as high as 11.61 kJ kg-1 K-1 at the latex concentration of 20.6 wt%. Thermal stability and viscosity testing show that this fluid had excellent resistance to thermal shock (after 100 cycles, no liquid Oct was observed during heating) and low viscosity (only 3.61 mPa s at the latex concentration of 20.6 wt%), which seems to be promising as a latent functionally thermal fluid.

  4. Functional and Morphological Changes in Endocrine Pancreas following Cola Drink Consumption in Rats

    PubMed Central

    2015-01-01

    Aim We report the effects of long-term cola beverage drinking on glucose homeostasis, endocrine pancreas function and morphology in rats. Methods Wistar rats drank: water (group W), regular cola beverage (group C, sucrose sweetened) or “light” cola beverage (group L, artificially sweetened). After 6 months, 50% of the animals in each group were euthanized and the remaining animals consumed water for the next 6 months when euthanasia was performed. Biochemical assays, insulinemia determination, estimation of insulin resistance (HOMA-IR), morphometry and immunohistochemistry evaluations were performed in pancreas. Results Hyperglycemia (16%, p<0.05), CoQ10 (coenzyme-Q10) decrease (−52%,p<0.01), strong hypertriglyceridemia (2.8-fold, p<0.01), hyperinsulinemia (2.4 fold, p<0.005) and HOMA-IR increase (2.7 fold, p<0.01) were observed in C. Group C showed a decrease in number of α cells (−42%, p<0.01) and β cells (−58%, p<0.001) and a moderate increase in α cells’ size after wash-out (+14%, p<0.001). Group L showed reduction in β cells’ size (−9%, p<0.001) and only after wash-out (L12) a 19% increase in size (p<0.0001) with 35% decrease in number of α cells (p<0.01). Groups C and L showed increase in α/β-cell ratio which was irreversible only in C (α/β = +38% in C6,+30% in C12, p<0.001vs.W6). Regular cola induced a striking increase in the cytoplasmic expression of Trx1 (Thioredoxin-1) (2.25-fold in C6 vs. W6; 2.7-fold in C12 vs. W12, p<0.0001) and Prx2 (Peroxiredoxin-2) (3-fold in C6 vs. W6; 2-fold in C12 vs. W12, p<0.0001). Light cola induced increase in Trx1 (3-fold) and Prx2 (2-fold) after wash-out (p<0.0001, L12 vs. W12). Conclusion Glucotoxicity may contribute to the loss of β cell function with depletion of insulin content. Oxidative stress, suggested by increased expression of thioredoxins and low circulating levels of CoQ10, may follow sustained hyperglycemia. A likely similar panorama may result from the effects of artificially

  5. The Swimming Ammonite: How Computed Tomography can Address Questions of Functional Morphology

    NASA Astrophysics Data System (ADS)

    Lemanis, Robert; Hoffmann, Rene; Zachow, Stefan

    2014-05-01

    The external shell of the ammonite is a readily recognized and iconic fossil yet the function of this structure remain contested. The shell is divided into the phragmocone, comprised of a series of mostly gas filled chambers separated by septa, and the body chamber where the animal would have resided. Quantitative studies of the functional morphology of the shell have relied on geometric simplifications and mathematical models which limit accuracy and invite controversy. Past work has used simplified models which showed adult ammonites as negatively buoyant and were the basis for arguments of a benthic mode of life for adult ammonites. Many palaeobiologists however argue ammonites lived in the water column, if this is true then the shell must possess neutral/positive buoyancy to allow the animal to live in the water column without expending energy to stay afloat. Using exceptionally preserved hollow ammonite fossils and the shells of modern cephalopods: the external shell of Nautilus pompilius and the internal shell of Spirula spirula, we employ micro-CT, nano-CT and synchrotron x-ray tomography techniques to construct 3D models that are used to evaluate the buoyant properties of the cephalopod phragmocone. This method is applied to the Nautilus to evaluate the accuracy of the method and demonstrates the utility of CT data in volumetric analyses. The phragmocone of a hatchling Spirula seems to be capable of supporting the body in the water column with a single chamber, however difficulties in estimating the volume of the soft body create divergent developments of the buoyant properties through ontogeny. Further investigation of the hatchling ammonite Cadoceras show that it was capable of achieving neutral/positive buoyancy provided the phragmocone possess three or more chambers. Using this technique we are able to reconstruct the ability of the Nautilus and Spirula to maintain a position in the water column by exploiting the buoyancy of the phragmocone. This method

  6. Investigation of functional and morphological integrity of freshly isolated and cryopreserved human hepatocytes.

    PubMed

    Ostrowska, A; Bode, D C; Pruss, J; Bilir, B; Smith, G D; Zeisloft, S

    2000-01-01

    There is a pressing need for alternative therapeutic methods effective in the treatment of patients with liver insufficiency. Isolated human hepatocytes may be a viable alternative or adjunct to orthotopic liver transplantation in such patients. The purpose of this study was to evaluate the viability and functional integrity of freshly isolated and cryopreserved human hepatocytes, in preparation for a multi-center human hepatocyte transplantation trial. We are currently processing transplant-grade human parenchymal liver cells from nondiseased human livers that are obtained through a network of organ procurement organizations (OPOs). Thus far, sixteen hepatocyte transplants have been performed using hepatocytes processed by our methods. At the time of referral all specimens were deemed unsuitable for transplantation due to anatomical anomalies, high fat content, medical history, etc. Hepatocytes were isolated from encapsulated liver sections by a modified two-step perfusion technique. Isolated cells were cryopreserved and stored in liquid nitrogen for one to twelve months. The total yield of freshly isolated hepatocytes averaged 3.7x10(7) cells per gram of wet tissue. Based on trypan blue exclusion, fresh preparations contained an average of 85% viable hepatocytes vs. 70% in cryopreserved samples. The plating efficiencies of cells seeded immediately after isolation ranged from 87% to 98%, while those of cryopreserved/thawed cells were markedly lower. Flow cytometry analysis of cells labeled with 5,6-carboxyfluorescein diacetate succinimidyl ester (CFSE) showed that there was no significant difference in viability compared with trypan blue staining. Both freshly isolated hepatocytes and those recovered from cryopreservation showed typical and intact morphology as demonstrated by light and electron microscopy. The product of the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) reaction was always expressed more intensely in cultures of freshly

  7. Morphological and functional manifestations of rat adrenal-cortex response to sodium bromide administration under hypodynamic stress

    NASA Technical Reports Server (NTRS)

    Kirichek, L. T.; Zholudeva, V. I.

    1979-01-01

    Functional and morphological manifestations of adrenal cortex response to hypodynamia (2-hr immobilization on an operating table) under the influence of bromine preparations were studied. The sodium bromide was administered intraperitoneally in 100, 250, and 500 mg/kg doses once and repeatedly during ten days. The adrenal gland was evaluated functionally by ascorbic acid and cholesterol content and morphologically by coloring it with hematoxylin-eosin and Sudans for lipid revealing at freezing. Results are displayed in two tables and microphotographs. They are summarized as follows: the bromine weakens the functional state of the adrenal cortex in intact rats, causing changes similar to those under stress. During immobilization combined with preliminary bromine administration, a less pronounced stress reaction is noticeable.

  8. Fabrication and characterization of dual-functional ultrafine composite fibers with phase-change energy storage and luminescence properties

    NASA Astrophysics Data System (ADS)

    Xi, Peng; Zhao, Tianxiang; Xia, Lei; Shu, Dengkun; Ma, Menjiao; Cheng, Bowen

    2017-01-01

    Ultrafine composite fibers consisting of a thermoplastic polyurethane solid-solid phase-change material and organic lanthanide luminescent materials were prepared through a parallel electrospinning technique as an innovative type of ultrafine, dual-functional fibers containing phase-change and luminescent properties. The morphology and structure, thermal energy storage, and luminescent properties of parallel electrospun ultrafine fibers were investigated. Scanning electron microscopy (SEM) images showed that the parallel electrospun ultrafine fibers possessed the desired morphologies with smaller average fiber diameters than those of traditional mixed electrospun ultrafine fibers. Transmission electron microscopy (TEM) images revealed that the parallel electrospun ultrafine fibers were composed of two parts. Polymeric phase-change materials, which can be directly produced and spun, were used to provide temperature stability, while a mixture of polymethyl methacrylate and an organic lanthanide complex acted as the luminescent unit. Differential scanning calorimetry (DSC) and luminescence measurements indicated that the unique structure of the parallel electrospun ultrafine fibers provides the products with good thermal energy storage and luminescence properties. The fluorescence intensity and the phase-change enthalpy values of the ultrafine fibers prepared by parallel electrospinning were respectively 1.6 and 2.1 times those of ultrafine fibers prepared by mixed electrospinning.

  9. Fabrication and characterization of dual-functional ultrafine composite fibers with phase-change energy storage and luminescence properties.

    PubMed

    Xi, Peng; Zhao, Tianxiang; Xia, Lei; Shu, Dengkun; Ma, Menjiao; Cheng, Bowen

    2017-01-09

    Ultrafine composite fibers consisting of a thermoplastic polyurethane solid-solid phase-change material and organic lanthanide luminescent materials were prepared through a parallel electrospinning technique as an innovative type of ultrafine, dual-functional fibers containing phase-change and luminescent properties. The morphology and structure, thermal energy storage, and luminescent properties of parallel electrospun ultrafine fibers were investigated. Scanning electron microscopy (SEM) images showed that the parallel electrospun ultrafine fibers possessed the desired morphologies with smaller average fiber diameters than those of traditional mixed electrospun ultrafine fibers. Transmission electron microscopy (TEM) images revealed that the parallel electrospun ultrafine fibers were composed of two parts. Polymeric phase-change materials, which can be directly produced and spun, were used to provide temperature stability, while a mixture of polymethyl methacrylate and an organic lanthanide complex acted as the luminescent unit. Differential scanning calorimetry (DSC) and luminescence measurements indicated that the unique structure of the parallel electrospun ultrafine fibers provides the products with good thermal energy storage and luminescence properties. The fluorescence intensity and the phase-change enthalpy values of the ultrafine fibers prepared by parallel electrospinning were respectively 1.6 and 2.1 times those of ultrafine fibers prepared by mixed electrospinning.

  10. Fabrication and characterization of dual-functional ultrafine composite fibers with phase-change energy storage and luminescence properties

    PubMed Central

    Xi, Peng; Zhao, Tianxiang; Xia, Lei; Shu, Dengkun; Ma, Menjiao; Cheng, Bowen

    2017-01-01

    Ultrafine composite fibers consisting of a thermoplastic polyurethane solid-solid phase-change material and organic lanthanide luminescent materials were prepared through a parallel electrospinning technique as an innovative type of ultrafine, dual-functional fibers containing phase-change and luminescent properties. The morphology and structure, thermal energy storage, and luminescent properties of parallel electrospun ultrafine fibers were investigated. Scanning electron microscopy (SEM) images showed that the parallel electrospun ultrafine fibers possessed the desired morphologies with smaller average fiber diameters than those of traditional mixed electrospun ultrafine fibers. Transmission electron microscopy (TEM) images revealed that the parallel electrospun ultrafine fibers were composed of two parts. Polymeric phase-change materials, which can be directly produced and spun, were used to provide temperature stability, while a mixture of polymethyl methacrylate and an organic lanthanide complex acted as the luminescent unit. Differential scanning calorimetry (DSC) and luminescence measurements indicated that the unique structure of the parallel electrospun ultrafine fibers provides the products with good thermal energy storage and luminescence properties. The fluorescence intensity and the phase-change enthalpy values of the ultrafine fibers prepared by parallel electrospinning were respectively 1.6 and 2.1 times those of ultrafine fibers prepared by mixed electrospinning. PMID:28067299

  11. Phase structures and morphologies determined by competitions among self-organization, crystallization, and vitrification in a disordered poly(ethylene oxide)-b-polystyrene diblock copolymer

    NASA Astrophysics Data System (ADS)

    Zhu, Lei; Chen, Yan; Zhang, Anqiu; Calhoun, Bret H.; Chun, Moonseok; Quirk, Roderic P.; Cheng, Stephen Z. D.; Hsiao, Benjamin S.; Yeh, Fengji; Hashimoto, Takeji

    1999-10-01

    A poly(ethylene oxide)-b-polystyrene (PEO-b-PS) diblock copolymer having a number-average molecular weight (M¯n) of 11 000 g/mol in the PEO blocks and an M¯n of 5200 g/mol in the PS blocks has been synthesized (with a volume fraction of the PEO blocks of 0.66 in the molten state). Differential scanning calorimetry results show that this copolymer possesses a single endotherm, which is attributed to the melting of the PEO-block crystals. Based on real-time resolved synchrotron small-angle x-ray scattering (SAXS) observations, the diblock copolymer is in a disordered state above the glass transition temperature of the PS-rich phase (TPSg), which has been determined to be 44.0 °C during cooling using dilatometer mode in thermomechanical measurements. The order-disorder transition temperature (TODT) for this diblock copolymer is thus experimentally inaccessible. Depending upon different isothermal crystallization temperatures quenched from the disordered state (Tqs), four cases can be investigated in order to understand the phase relationships among self-organization, crystallization of the PEO blocks, and vitrification of the PS-rich phase: the region where the Tq is above the TPSg, the regions where the Tq is near but slightly higher or lower than the TPSg; and the region where the Tq is below the TPSg. Utilizing simultaneous SAXS and wide angle x-ray-diffraction experiments, it can be seen that lamellar crystals of the PEO blocks in the first case grow with little morphological constraint due to initial disordered phase morphology. As the Tq approaches but is still slightly higher than the TPSg, as in the second case, the PEO-block crystals with a greater long period (L) than that of the disordered state start to grow. The initial disordered phase morphology is gradually destroyed, at least to a major extent. When the Tq is near but slightly lower than the TPSg, the crystallization takes place largely within the existing phase morphology. Only a gradual shift of

  12. The influence of the choice of the oceanic phase function on imaging under water

    NASA Astrophysics Data System (ADS)

    Braesicke, K.; Repasi, E.

    2015-05-01

    There is a large diversity of phase functions for the computer simulation of light under water. Some papers look at the influence of these phase functions on the results of computer simulations of the remote sensing reflectance. We study the influence of these phase functions on the computer simulation of the resulting image of a target illuminated by a laser. For these simulations we are only interested in those parts of the light that reach the camera position. Therefor we investigate the influence of the phase function on the image. We use a Monte Carlo Simulator with several Fournier-Forand, Henyey-Greenstein phase functions. The resulting signals at the receiver of these simulations are compared to a simulation with a Petzold function that is based on measurements of the phase function.

  13. Open and closed evolutionary paths for drastic morphological changes, involving serial gene duplication, sub-functionalization, and selection

    PubMed Central

    Abe, Gembu; Lee, Shu-Hua; Li, Ing-Jia; Chang, Chun-Ju; Tamura, Koji; Ota, Kinya G.

    2016-01-01

    Twin-tail goldfish strains are examples of drastic morphological alterations that emerged through domestication. Although this mutation is known to be caused by deficiency of one of two duplicated chordin genes, it is unknown why equivalent mutations have not been observed in other domesticated fish species. Here, we compared the chordin gene morphant phenotypes of single-tail goldfish and common carp (close relatives, both of which underwent chordin gene duplication and domestication). Morpholino-induced knockdown depleted chordin gene expression in both species; however, while knockdown reproduced twin-tail morphology in single-tail goldfish, it had no effect on common carp morphology. This difference can be explained by the observation that expression patterns of the duplicated chordin genes overlap completely in common carp, but are sub-functionalized in goldfish. Our finding implies that goldfish drastic morphological changes might be enhanced by the subsequent occurrence of three different types of evolutionary event (duplication, sub-functionalization, and selection) in a certain order. PMID:27220684

  14. Morphological and functional alteration of erythrocyte ghosts and giant unilamellar vesicles caused by Vipera latifi venom.

    PubMed

    Kirakosyan, Gayane; Mohamadvarzi, Maryam; Ghulikyan, Lusine; Zaqaryan, Naira; Kishmiryan, Arsen; Ayvazyan, Naira

    2016-12-01

    Snake bites are an endemic public health problem in Iran, both in rural and urban area. Viper venom as a hemolytic biochemical "cocktail" of toxins, primarily cause to the systemic alteration of blood cells. In the sixties and seventies, human erythrocytes were extensively studied, but the mechanical and chemical stresses commonly exerted on red blood cells continue to attract interest of scientists for the study of membrane structure and function. Here, we monitor the effect of Vipera latifi venom on human erythrocytes ghost membranes using phase contrast and fluorescent microscopy and changes in ATPase activity under snake venom influence in vitro. The ion pumps [Na(+),K(+)]-ATPase and (Ca(2+)+Mg(2+))-ATPase plays a pivotal role in the active transport of certain cations and maintenance of intracellular electrolyte homeostasis. We also describe the interaction of Vipera latifi (VL) venom with giant unilamellar vesicles (GUVs) composed of the native phospholipid mixtures visualized by the membrane fluorescence probe, ANS, used to assess the state of membrane and specifically mark the phospholipid domains.

  15. Morphology, mineralogy, and solid-liquid phase separation characteristics of Cu and Zn precipitates produced with biogenic sulfide.

    PubMed

    Villa-Gomez, D K; van Hullebusch, E D; Maestro, R; Farges, F; Nikitenko, S; Kramer, H; Gonzalez-Gil, G; Lens, P N L

    2014-01-01

    The morphology, mineralogy, and solid-liquid phase separation of the Cu and Zn precipitates formed with sulfide produced in a sulfate-reducing bioreactor were studied at pH 3, 5, and 7. The precipitates formed at pH 7 display faster settling rates, better dewaterability, and higher concentrations of settleable solids as compared to the precipitates formed at pH 3 and 5. These differences were linked to the agglomeration of the sulfidic precipitates and coprecipitation of the phosphate added to the bioreactor influent. The Cu and Zn quenched the intensity of the dissolved organic matter peaks identified by fluorescence-excitation emission matrix spectroscopy, suggesting a binding mechanism that decreases supersaturation, especially at pH 5. X-ray absorption fine structure spectroscopy analyses confirmed the precipitation of Zn-S as sphalerite and Cu-S as covellite in all samples, but also revealed the presence of Zn sorbed on hydroxyapatite. These analyses further showed that CuS structures remained amorphous regardless of the pH, whereas the ZnS structure was more organized at pH 5 as compared to the ZnS formed at pH 3 and 7, in agreement with the cubic sphalerite-type structures observed through scanning electron microscopy at pH 5.

  16. One-Step Liquid-Phase Synthesis of Carbon Nanotubes: Effects of Substrate Materials on Morphology of Carbon Nanotubes

    NASA Astrophysics Data System (ADS)

    Yamagiwa, Kiyofumi; Ayato, Yusuke; Kuwano, Jun

    2012-06-01

    Effects of substrate materials and shapes have been investigated in the one-step liquid-phase (OS-LP) synthesis of carbon nanotubes (CNTs). Similar highly aligned multi-walled CNT (MWCNT) arrays (HACNTAs) with a height (ha) of ˜30 µm were synthesized on the substrates of commercially available stainless steel and Inconel® alloy by a resistance heating method in methanol containing cobaltocene, whereas aligned MWCNT arrays (ha≈10 µm) with slightly poor alignment were formed on the titanium substrate, compared with those of the former two. On the other hand, very short, non-aligned MWCNTs with a length of ˜1 µm were deposited on a silicon substrate. The different morphologies depending on the substrate materials are related with interaction between the pyrolytically-generated Co atoms and the surface oxide layers of the substrates. In addition, we have for the first time demonstrated that the OS-LP synthesis is suitable for CNT-coating onto intricately-shaped substrates like stainless steel mesh.

  17. Morphology and phase modifications of MoO{sub 3} obtained by metallo-organic decomposition processes

    SciTech Connect

    Barros Santos, Elias de; Martins de Souza e Silva, Juliana; Odone Mazali, Italo

    2010-11-15

    Molybdenum oxide samples were prepared using different temperatures and atmospheric conditions by metallo-organic decomposition processes and were characterized by XRD, SEM and DRS UV/Vis and Raman spectroscopies. Variation in the synthesis conditions resulted in solids with different morphologies and oxygen vacancy concentrations. Intense characteristic Raman bands of crystalline orthorhombic {alpha}-MoO{sub 3}, occurring at 992 cm{sup -1} and 820 cm{sup -1}, are observed and their shifts can be related to the differences in the structure of the solids obtained. The sample obtained under nitrogen flow at 1073 K is a phase mixture of orthorhombic {alpha}-MoO{sub 3} and monoclinic {beta}-MoO{sub 3}. The characterization results suggest that the molybdenum oxide samples are non-stoichiometric and are described as MoO{sub x} with x < 2.94. Variations in the reaction conditions make it possible to tune the number of oxygen defects and the band gap of the final material.

  18. Diblock copolymers of polystyrene-b-poly(1,3-cyclohexadiene) exhibiting unique three-phase microdomain morphologies

    DOE PAGES

    Misichronis, Konstantinos; Chen, Jihua; Kahk, Jong K.; ...

    2016-03-29

    Here, the synthesis and molecular characterization of a series of conformationally asymmetric polystyrene-block-poly(1,3-cyclohexadiene) (PS-b-PCHD) diblock copolymers (PCHD: ~90% 1,4 and ~10% 1,2), by sequential anionic copolymerization high vacuum techniques, is reported. A wide range of volume fractions (0.27 ≤ ΦPS ≤ 0.91) was studied by transmission electron microscopy and small-angle X-ray scattering in order to explore in detail the microphase separation behavior of these flexible/semiflexible diblock copolymers. Unusual morphologies, consisting of PCHD core(PCHD-1,4)–shell(PCHD-1,2) cylinders in PS matrix and three-phase (PS, PCHD-1,4, PCHD-1,2) four-layer lamellae, were observed suggesting that the chain stiffness of the PCHD block and the strong dependence ofmore » the interaction parameter χ on the PCHD microstructures are important factors for the formation of this unusual microphase separation behavior in PS-b-PCHD diblock copolymers. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2016, 54, 1564–1572« less

  19. Thermodynamic-Controlled Gas Phase Process for the Synthesis of Nickel Nanoparticles of Adjustable Size and Morphology

    NASA Astrophysics Data System (ADS)

    Kauffeldt, Elena; Kauffeldt, Thomas

    2006-08-01

    Gas phase processes are a successful route for the synthesis of nano materials. Nickel particles are used in applications ranging from catalysis to nano electronics and energy storage. The application field defines the required particle size, morphology, crystallinity and purity. Nickel tetracarbonyl is the most promising precursor for the synthesis of high purity nickel particles. Due to the toxicity of this precursor and to obtain an optimal process control we developed a two-step flow type process. Nickel carbonyl and nickel particles are synthesized in a sequence of reactions. The particles are formed in a hot wall reactor at temperatures below 400°C in different gas compositions. Varying the process conditions enables the adjustment of the particle size in a range from 3 to 140 nm. The controllable crystalline habits are polycrystalline, single crystals or multiple twinned particles (MTP). Spectroscopic investigations show an excellent purity. We report about the process and first investigations of the properties of the synthesized nickel nanomaterial.

  20. Diblock copolymers of polystyrene-b-poly(1,3-cyclohexadiene) exhibiting unique three-phase microdomain morphologies

    SciTech Connect

    Misichronis, Konstantinos; Chen, Jihua; Kahk, Jong K.; Imel, Adam; Dadmun, Mark; Hong, Kunlun; Hadjichristidis, Nikos; Mays, Jimmy W.; Avgeropoulos, Apostolos

    2016-03-29

    Here, the synthesis and molecular characterization of a series of conformationally asymmetric polystyrene-block-poly(1,3-cyclohexadiene) (PS-b-PCHD) diblock copolymers (PCHD: ~90% 1,4 and ~10% 1,2), by sequential anionic copolymerization high vacuum techniques, is reported. A wide range of volume fractions (0.27 ≤ ΦPS ≤ 0.91) was studied by transmission electron microscopy and small-angle X-ray scattering in order to explore in detail the microphase separation behavior of these flexible/semiflexible diblock copolymers. Unusual morphologies, consisting of PCHD core(PCHD-1,4)–shell(PCHD-1,2) cylinders in PS matrix and three-phase (PS, PCHD-1,4, PCHD-1,2) four-layer lamellae, were observed suggesting that the chain stiffness of the PCHD block and the strong dependence of the interaction parameter χ on the PCHD microstructures are important factors for the formation of this unusual microphase separation behavior in PS-b-PCHD diblock copolymers. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2016, 54, 1564–1572

  1. Morphology and phase structures of CW laser-induced oxide layers on iron surface with evolving reflectivity and colors

    NASA Astrophysics Data System (ADS)

    Wu, Taotao; Wang, Lijun; Wei, Chenghua; Zhou, Menglian; He, Minbo; Wu, Lixiong

    2016-11-01

    Laser-induced oxidation will change the laser reflectivity and color features of metal surface. Both changes can be theoretically calculated based on the oxidation kinetics and the optical constants of oxides. For the purpose of calculation, the laser-induced oxidation process of pure polycrystalline iron was studied. Samples with various color features were obtained by continuous wave Nd:YAG fiber laser (1.06 μm) irradiation depending on progressive durations in the intensity of 1.90 W/cm2. The real-time reflectivity and temperature were measured with integral sphere and thermocouples. The irradiated surface morphology and phase structures were characterized by microscope, X-ray diffraction and Raman spectrum. It was found that the first formed magnetite made the surface reflectivity decline rapidly and caused the "positive feedback" effect because of molecular absorption. The later formed hematite oscillated the reflectivity by interference effect. The oxide films were thin, orientated and badly crystallized. The oxidation process was influenced by the grain orientation of the metal substrate. These results made the mechanism of laser-induced oxidation of iron clear and provided available experimental data for accurate modeling of the oxidation kinetics.

  2. The spinning apparatus of webspinners – functional-morphology, morphometrics and spinning behaviour

    PubMed Central

    Büsse, Sebastian; Hörnschemeyer, Thomas; Hohu, Kyle; McMillan, David; Edgerly, Janice S.

    2015-01-01

    Webspinners (Insecta: Embioptera) have a distinctly unique behaviour with related morphological characteristics. Producing silk with the basitarsomeres of their forelegs plays a crucial role in the lives of these insects – providing shelter and protection. The correlation between body size, morphology and morphometrics of the spinning apparatus and the spinning behaviour of Embioptera was investigated for seven species using state-of-the-art methodology for behavioural as well as for morphological approaches. Independent contrast analysis revealed correlations between morphometric characters and body size. Larger webspinners in this study have glands with greater reservoir volume, but in proportionally smaller tarsi relative to body size than in the smaller species. Furthermore, we present a detailed description and review of the spinning apparatus in Embioptera in comparison to other arthropods and substantiate the possible homology of the embiopteran silk glands to class III dermal silk glands of insects. PMID:25950122

  3. Morphological variation of the thoracolumbar vertebrae in Macropodidae and its functional relevance.

    PubMed

    Chen, Xinmin; Milne, Nick; O'Higgins, Paul

    2005-11-01

    information about vertebral shape variation along the thoracolumbar column. The results reinforce and emphasize important aspects of the patterns of variation seen in the detailed analysis of the third lumbar vertebra. The results also imply that size, spinal loading pattern, and locomotor behavior exert an influence on shaping the vertebra. Further, the morphological adaptations are consistent within these marsupials and this opens up the possibility that this kind of analysis may be useful in making functional inferences from fossil material.

  4. Macular function and morphological features in juvenile Stargardt disease: Longitudinal study

    PubMed Central

    Testa, Francesco; Melillo, Paolo; Iorio, Valentina Di; Orrico, Ada; Attanasio, Marcella; Rossi, Settimio; Simonelli, Francesca

    2014-01-01

    decline of visual functionality and detecting morphological macular changes proves useful to evaluate disease progression over a short-term follow-up and should be taken into account for the design of future gene therapy clinical trials to treat retinal dystrophy. PMID:25097154

  5. Radiographic and electrocardiographic evaluation of cardiac morphology and function in captive cheetahs (Acinonyx jubatus).

    PubMed

    Schumacher, Juergen; Snyder, Patti; Citino, Scott B; Bennett, R Avery; Dvorak, Laura D

    2003-12-01

    In a prospective study, eight (four males and four females) healthy, adult captive cheetahs (Acinonyx jubatus) were immobilized with a combination of tiletamine-zolazepam (4 mg/kg, i.m.), administered with a remote drug delivery system, to define normal cardiac morphology and function. Standard lateral and ventrodorsal (VD) radiographs were then taken to measure heart and thorax using a metric and vertebral scale system. Standard six-lead electrocardiograms were obtained with the animals in right lateral recumbency under isoflurane anesthesia. Mean chest depth and width was 18.7 +/- 1.3 cm and 13.0 +/- 0.6 cm, respectively. The mean lateral cardiac short axis (X) was 9.1 +/- 0.6 cm. the mean cardiac long axis (Y) was 13.6 +/- 0.7 cm, and the mean lateral heart sum (X + Y) was 22.6 +/- 1.2 cm. In the VD projection, mean cardiac short axis (V) was 10.1 +/- 0.7 cm, mean cardiac long axis (W) was 14.9 +/- 1.2 cm, and the heart sum (V + W) was 24.9 +/- 1.8 cm. The vertebral heart size was 8.2 +/- 0.9. All cheetahs had sinus rhythm, and no arrhythmias were noted. Mean heart rate was 126 +/- 15 beats/min, and the mean electrical axis was 82 + 5 degrees. P waves were always positive on lead II and had a width of 0.04 +/- 0.01 sec and a height between 0.1 and 0.3 mV. PR intervals were 0.11 +/- 0.01 sec. The height of the QRS complex was 1.25 +/- 0.24 mV and the width 0.06 +/- 0.01 sec. The ST segment was 0.04 sec, and the T wave (height: 0.25 +/- 0.05 mV) was positive in all cheetahs examined. Although these cardiac and thoracic measurements were larger than those of domestic cats (Felis catus), ratios of cardiac parameters were similar in both species. Electrocardiographic findings were similar to those reported from domestic cats.

  6. Multiple-region directed functional connectivity based on phase delays.

    PubMed

    Goelman, Gadi; Dan, Rotem

    2017-03-01

    Network analysis is increasingly advancing the field of neuroimaging. Neural networks are generally constructed from pairwise interactions with an assumption of linear relations between them. Here, a high-order statistical framework to calculate directed functional connectivity among multiple regions, using wavelet analysis and spectral coherence has been presented. The mathematical expression for 4 regions was derived and used to characterize a quartet of regions as a linear, combined (nonlinear), or disconnected network. Phase delays between regions were used to obtain network's temporal hierarchy and directionality. The validity of the mathematical derivation along with the effects of coupling strength and noise on its outcomes were studied by computer simulations of the Kuramoto model. The simulations demonstrated correct directionality for a large range of coupling strength and low sensitivity to Gaussian noise compared with pairwise coherences. The analysis was applied to resting-state fMRI data of 40 healthy young subjects to characterize the ventral visual system, motor system and default mode network (DMN). It was shown that the ventral visual system was predominantly composed of linear networks while the motor system and the DMN were composed of combined (nonlinear) networks. The ventral visual system exhibits its known temporal hierarchy, the motor system exhibits center ↔ out hierarchy and the DMN has dorsal ↔ ventral and anterior ↔ posterior organizations. The analysis can be applied in different disciplines such as seismology, or economy and in a variety of brain data including stimulus-driven fMRI, electrophysiology, EEG, and MEG, thus open new horizons in brain research. Hum Brain Mapp 38:1374-1386, 2017. © 2016 Wiley Periodicals, Inc.

  7. Development and functional morphology of the mouthparts and foregut in larvae and post-larvae of Macrobrachium jelskii (Decapoda: Palaemonidae).

    PubMed

    Rocha, Cristina Pantoja; Souza, Adelson Silva de; Maciel, Murilo; Maciel, Cristiana R; Abrunhosa, Fernando Araújo

    2016-05-01

    The morphology of the mouthparts and foregut of the larvae and post-larvae of Macrobrachium jelskii was investigated to determine their functional roles in feeding, in order to understand the larval feeding behaviour and the changes that occur during its development. The mouthparts and foregut of the zoea I and II are morphologically similar, rudimentary and non-functional in feeding. Only in the final larval stage, zoea III, do the external mouthparts and foregut become structurally more complex and thus likely to play a potential role in feeding. Two behavioral trials (point of no return, point of reserve saturation) evaluated the resistance to starvation in zoea I, II, and III. The results indicate that they have sufficient nutritional reserves to permit them to complete metamorphosis without feeding. Overall, our results suggest that the zoea I and II of Macrobrachium jelskii engage in obligate lecithotrophy and zoea III in facultative lecithotrophy.

  8. Comparative morphology of the gallbladder and biliary tract in vertebrates: variation in structure, homology in function and gallstones.

    PubMed

    Oldham-Ott, C K; Gilloteaux, J

    1997-09-15

    A review of investigations on the morphology of the gallbladder and biliary tract in fish, reptiles, amphibians, birds, and mammals was performed. Scanning electron microscopy, transmission electron microscopy, and light microscopy observations by the authors were also included. Variations in the presence or absence of a gallbladder, surface epithelium of the gallbladder, and differences in the morphology of the biliary tract in vertebrates were reported. Many differences were diet-related. Despite some dissimilarities observed, analogous functioning of the biliary system was accomplished by its various components, with the biliary ducts performing the function of the gallbladder when this organ was absent. In addition, the occurrence of peculiar parasitism and gallstones among some cases of vertebrates, including humans, was presented.

  9. Nanoscale Morphology of PTB7 Based Organic Photovoltaics as a Function of Fullerene Size

    PubMed Central

    Roehling, John D.; Baran, Derya; Sit, Joseph; Kassar, Thaer; Ameri, Tayebeh; Unruh, Tobias; Brabec, Christoph J.; Moulé, Adam J.

    2016-01-01

    High efficiency polymer:fullerene photovoltaic device layers self-assemble with hierarchical features from ångströms to 100’s of nanometers. The feature size, shape, composition, orientation, and order all contribute to device efficiency and are simultaneously difficult to study due to poor contrast between carbon based materials. This study seeks to increase device efficiency and simplify morphology measurements by replacing the typical fullerene acceptor with endohedral fullerene Lu3N@PC80BEH. The metal atoms give excellent scattering contrast for electron beam and x-ray experiments. Additionally, Lu3N@PC80BEH has a lower electron affinity than standard fullerenes, which can raise the open circuit voltage of photovoltaic devices. Electron microscopy techniques are used to produce a detailed account of morphology evolution in mixtures of Lu3N@PC80BEH with the record breaking donor polymer, PTB7 and coated using solvent mixtures. We demonstrate that common solvent additives like 1,8-diiodooctane or chloronapthalene do not improve the morphology of endohedral fullerene devices as expected. The poor device performance is attributed to the lack of mutual miscibility between this particular polymer:fullerene combination and to co-crystallization of Lu3N@PC80BEH with 1,8-diiodooctane. This negative result explains why solvent additives mixtures are not necessarily a morphology cure-all. PMID:27498880

  10. Distinct effects of dipeptidyl peptidase-4 inhibitor and glucagon-like peptide-1 receptor agonist on islet morphology and function.

    PubMed

    Morita, Asuka; Mukai, Eri; Hiratsuka, Ayano; Takatani, Tomozumi; Iwanaga, Toshihiko; Lee, Eun Young; Miki, Takashi

    2016-03-01

    Although the two anti-diabetic drugs, dipeptidyl peptidase-4 inhibitors (DPP4is) and glucagon-like peptide-1 (GLP-1) receptor agonists (GLP1RAs), have distinct effects on the dynamics of circulating incretins, little is known of the difference in their consequences on morphology and function of pancreatic islets. We examined these in a mouse model of β cell injury/regeneration. The model mice were generated so as to express diphtheria toxin (DT) receptor and a fluorescent protein (Tomato) specifically in β cells. The mice were treated with a DPP4i (MK-0626) and a GLP1RA (liraglutide), singly or doubly, and the morphology and function of the islets were compared. Prior administration of MK-0626 and/or liraglutide similarly protected β cells from DT-induced cell death, indicating that enhanced GLP-1 signaling can account for the cytoprotection. However, 2-week intervention of MK-0626 and/or liraglutide in DT-injected mice resulted in different islet morphology and function: β cell proliferation and glucose-stimulated insulin secretion (GSIS) were increased by MK-0626 but not by liraglutide; α cell mass was decreased by liraglutide but not by MK-0626. Although liraglutide administration nullified MK-0626-induced β cell proliferation, their co-administration resulted in increased GSIS, decreased α cell mass, and improved glucose tolerance. The pro-proliferative effect of MK-0626 was lost by co-administration of the GLP-1 receptor antagonist exendin-(9-39), indicating that GLP-1 signaling is required for this effect. Comparison of the effects of DPP4is and/or GLP1RAs treatment in a single mouse model shows that the two anti-diabetic drugs have distinct consequences on islet morphology and function.

  11. Synthesis of nanoparticles in a flame aerosol reactor with independent and strict control of their size, crystal phase and morphology

    NASA Astrophysics Data System (ADS)

    Jiang, Jingkun; Chen, Da-Ren; Biswas, Pratim

    2007-07-01

    A flame aerosol reactor (FLAR) was developed to synthesize nanoparticles with desired properties (crystal phase and size) that could be independently controlled. The methodology was demonstrated for TiO2 nanoparticles, and this is the first time that large sets of samples with the same size but different crystal phases (six different ratios of anatase to rutile in this work) were synthesized. The degree of TiO2 nanoparticle agglomeration was determined by comparing the primary particle size distribution measured by scanning electron microscopy (SEM) to the mobility-based particle size distribution measured by online scanning mobility particle spectrometry (SMPS). By controlling the flame aerosol reactor conditions, both spherical unagglomerated particles and highly agglomerated particles were produced. To produce monodisperse nanoparticles, a high throughput multi-stage differential mobility analyser (MDMA) was used in series with the flame aerosol reactor. Nearly monodisperse nanoparticles (geometric standard deviation less than 1.05) could be collected in sufficient mass quantities (of the order of 10 mg) in reasonable time (1 h) that could be used in other studies such as determination of functionality or biological effects as a function of size.

  12. Phase, Viscosity, Morphology, and Room Temperature Evaporation Rates of SOA Particles Generated from Different Precursors, at Low and High Relative Humidities, and their Interaction with Hydrophobic Organics

    NASA Astrophysics Data System (ADS)

    Wilson, J. M.; Zelenyuk, A.; Imre, D. G.; Beranek, J.; Abramson, E.; Shrivastava, M.

    2012-12-01

    Formation, properties, transformations, and temporal evolution of secondary organic aerosol (SOA) particles strongly depend on particle phase. Semi-volatile molecules that comprise SOA particles were assumed to form a low viscosity solution that maintains equilibrium with the evolving gas phase by rapid evaporation condensation. However, studies by our group indicate that laboratory-generated alpha-pinene SOA particles and ambient SOA characterized in a recent field campaign are in a semi-solid, highly viscous phase, and their evaporation rates are orders of magnitude slower than predicted. We present the results of recent studies in which we have extended our work to include SOA particles generated by oxidation of a number of precursors including limonene, n-alkenes, cyclo-alkenes and isoprene. The resulting particles are characterized by their phase, morphology and room temperature evaporation rates. We conclude that, while the detailed properties of SOA particles depend of their precursor, all studied SOA particles are highly viscous semi-solids that exhibit very slow evaporation rates. Given that atmospheric relative humidity (RH) can change particle phase, it is important to investigate the effect of RH on the phase and evaporation kinetics of SOA particles. To this end SOA particles were generated at low and high (~90%) RH, and their evaporation kinetics and phase were characterized as a function of RH. In the ambient atmosphere SOA particles form in the presence of a mixture of different organic compounds, which are present at or below their equilibrium vapor pressure, and thus have been ignored. However, our data show that these compounds can adsorb to the surface of particles during SOA formation, becoming trapped in the highly viscous SOA, and affect particle properties. We examine the interaction between SOA particles and different hydrophobic organics representing typical anthropogenic emissions by making SOA in the presence of the vapors of these

  13. An insight into the origin of low-symmetry bridging phase and enhanced functionality in systems containing competing phases

    PubMed Central

    Kong, Lingping; Liu, Gang; Yang, Wenge; Cao, Wenwu

    2015-01-01

    High piezoelectric activity of ferroelectrics with morphotropic phase boundary (MPB) compositions has been the focus of numerous recent investigations. The concept of a bridging low-symmetry phase between competing phase structures of the MPB composition remains controversial due to the compositional inhomogeneity near the MPB and the lack of appropriate experimental techniques to delineate the complex crystal structures. We have studied a simple ferroelectric BaTiO3 by employing a high resolution synchrotron-based technique, in which the formation of different symmetry regions due to chemical inhomogeneity can be ruled out. We observed two types of thermotropic phase boundaries, revealing the importance of interphase-strain in the formation of a bridging phase between competing phases and the enhancement of functionality. PMID:26339070

  14. Comparison of Morphological and Functional Endothelial Cell Changes after Cataract Surgery: Phacoemulsification Versus Manual Small-Incision Cataract Surgery

    PubMed Central

    Ganekal, Sunil; Nagarajappa, Ashwini

    2014-01-01

    Purpose: To compare the morphological (cell density, coefficient of variation and standard deviation) and functional (central corneal thickness) endothelial changes after phacoemulsification versus manual small-incision cataract surgery (MSICS). Design: Prospective randomized control study. Materials and Methods: In this prospective randomized control study, patients were randomly allocated to undergo phacoemulsification (Group 1, n = 100) or MSICS (Group 2, n = 100) using a random number Table. The patients underwent complete ophthalmic evaluation and specular microscopy preoperatively and at 1and 6 weeks postoperatively. Functional and morphological endothelial evaluation was Noncon ROBO PACHY SP-9000 specular microscope. Phacoemulsification was performed, the chop technique and MSICS, by the viscoexpression technique. Results: The mean difference in central corneal thickness at baseline and 1 week between Group 1 and Group 2 was statistically significant (P = 0.027). However, this difference at baseline when compared to 6 week and 1 week, 6 weeks was not statistically significant (P > 0.05). The difference in mean endothelial cell density between groups at 1 week and 6 weeks was statistically significant (P = 0.016). The mean coefficient of variation and mean standard deviation between groups were not statistically significant (P > 0.05, both comparisons). Conclusion: The central corneal thickness, coefficient of variation, and standard deviation were maintained in both groups indicating that the function and morphology of endothelial cells was not affected despite an initial reduction in endothelial cell number in MSICS. Thus, MSICS remains a safe option in the developing world. PMID:24669147

  15. Functional morphology of the Andean climbing catfishes (Astroblepidae, Siluriformes): alternative ways of respiration, adhesion, and locomotion using the mouth.

    PubMed

    De Crop, Wannes; Pauwels, Elin; Van Hoorebeke, Luc; Geerinckx, Tom

    2013-10-01

    Astroblepidae or "climbing catfishes" encompass a single genus of species living in high altitude rivers in the Andes of South America. They are characterized by a specialized head morphology closely resembling their better known, widely radiated sister family Loricariidae, or armored suckermouth catfishes. Existent data show that even though both families share important traits, there are some striking differences as well. Albeit poorly known, Astroblepus species possess a duplicated gill opening, and have the ability to climb vertical rocks or waterfalls. In this study, morphological and kinematic data are combined to yield insights into the functions of the mobile elements of the astroblepid head, and to compare head morphology and biomechanics with those of Loricariidae. We found that, even though there is substantial similarity in head structure of both families, there are major differences in functionally important structures. These include a different lower lip muscle configuration, an alternative oral valve system, and an incurrent gill opening only found in astroblepids. Kinematic analyses confirm that the astroblepid suckermouth, freed from its inhalatory function, offers advantages for climbing in the high-altitude environment, and is used alternately with the extremely mobile pelvic girdle, in a crawling, nonundulatory motion.

  16. Synthesis of Upconversion β-NaYF4:Nd3+/Yb3+/Er3+ Particles with Enhanced Luminescent Intensity through Control of Morphology and Phase

    PubMed Central

    Shang, Yunfei; Hao, Shuwei; Liu, Jing; Tan, Meiling; Wang, Ning; Yang, Chunhui; Chen, Guanying

    2015-01-01

    Hexagonal NaYF4:Nd3+/Yb3+/Er3+ microcrystals and nanocrystals with well-defined morphologies and sizes have been synthesized via a hydrothermal route. The rational control of initial reaction conditions can not only result in upconversion (UC) micro and nanocrystals with varying morphologies, but also can produce enhanced and tailored upconversion emissions from the Yb3+/Er3+ ion pairs sensitized by the Nd3+ ions. The increase of reaction time converts the phase of NaYF4:Nd3+/Yb3+/Er3+ particles from the cubic to the hexagonal structure. The added amount of oleic acid plays a critical role in the shape evolution of the final products due to their preferential attachment to some crystal planes. The adjustment of the molar ratio of F−/Ln3+ can range the morphologies of the β-NaYF4:Nd3+/Yb3+/Er3+ microcrystals from spheres to nanorods. When excited by 808 nm infrared laser, β-NaYF4:Nd3+/Yb3+/Er3+ microplates exhibit a much stronger UC emission intensity than particles with other morphologies. This phase- and morphology-dependent UC emission holds promise for applications in photonic devices and biological studies.

  17. Changes in two-phase emulsion morphology in temperature-amphiphile concentration or fish diagram for ternary amphiphile/oil/water systems.

    PubMed

    Lee, Jong-Moon; Lim, Kyung-Hee

    2005-10-01

    We examined the morphologies of two-phase emulsions in the ternary 2-butoxyethanol/n-decane/water system at various temperatures and water-to-oil ratios (WORs). The two-phase emulsion morphologies depended on temperature, WOR, and amphiphile concentration, and the results are presented in a temperature-amphiphile concentration coordinate system or a "fish" diagram. The observations made in this work contradict the predictions by the phase-inversion-temperature (PIT) concept. At WOR<1, a vertical inversion line was observed at Tphase region into the subregions of B/T (W/O) and T/B (O/W) emulsions. At T>T(uc) (upper critical endpoint temperature) and at low amphiphile concentrations, only B/T emulsions appeared, irrespective of temperature. At WOR>1, the situation was reversed; T/B emulsions at TT(uc), and T/B emulsions at low amphiphile concentrations, irrespective of temperature. At WOR=1, two horizontal inversion lines, one each at TT(uc), were observed. The morphologies of the two-phase emulsions were B/T or T/B emulsions at low amphiphile concentrations, and at higher amphiphile concentrations T/B at TT(uc). All these findings along with three-phase emulsion data result in complete emulsion morphology diagrams in the temperature-amphiphile concentration space or fish diagram.

  18. Chemical and morphological characteristics of solid metal-bearing phases deposited in snow and stream sediment as indicators of their origin.

    PubMed

    Miler, Miloš; Gosar, Mateja

    2015-02-01

    Detailed scanning electron microscopy/energy dispersive spectroscopy of metal-bearing particles in snow deposits and stream sediment from a steelworks area was performed. Identified metal-bearing phases were apportioned according to their chemical and morphological characteristics to anthropogenic phases and secondary weathering products. Anthropogenic metal-bearing phases are the most abundant in both media and are represented by various irregular ferrous oxides, ferrous alloys, spherical ferrous oxides, and ferrous silicates with variable contents of Cr, Mn, Ni, V, W, and Mo. Secondary weathering products are Al silicates, Fe oxy-hydroxides, and Fe oxy-hydroxy sulfates with minor contents of transition metals, resulting from weathering of anthropogenic phases and Pb-Zn ore minerals from a closed Pb-Zn mine located upstream from the study area. Comparison of anthropogenic metal-bearing phases in both media showed agreement in their compositions and morphologies and indicated their sources are high-temperature processes in steel production. It also showed that spherical metal-bearing phases were transported by the same transport medium, which is the atmosphere, while other phases were transported into stream sediment mostly by other pathways, such as precipitation runoff over contaminated surfaces.

  19. Trade-off between reservoir yield and evaporation losses as a function of lake morphology in semi-arid Brazil.

    PubMed

    Campos, José N B; Lima, Iran E; Studart, Ticiana M C; Nascimento, Luiz S V

    2016-05-31

    This study investigates the relationships between yield and evaporation as a function of lake morphology in semi-arid Brazil. First, a new methodology was proposed to classify the morphology of 40 reservoirs in the Ceará State, with storage capacities ranging from approximately 5 to 4500 hm3. Then, Monte Carlo simulations were conducted to study the effect of reservoir morphology (including real and simplified conical forms) on the water storage process at different reliability levels. The reservoirs were categorized as convex (60.0%), slightly convex (27.5%) or linear (12.5%). When the conical approximation was used instead of the real lake form, a trade-off occurred between reservoir yield and evaporation losses, with different trends for the convex, slightly convex and linear reservoirs. Using the conical approximation, the water yield prediction errors reached approximately 5% of the mean annual inflow, which is negligible for large reservoirs. However, for smaller reservoirs, this error became important. Therefore, this paper presents a new procedure for correcting the yield-evaporation relationships that were obtained by assuming a conical approximation rather than the real reservoir morphology. The combination of this correction with the Regulation Triangle Diagram is useful for rapidly and objectively predicting reservoir yield and evaporation losses in semi-arid environments.

  20. On the development, morphology and function of the temporomandibular joint in the light of the orofacial system.

    PubMed

    Fanghänel, Jochen; Gedrange, Tomasz

    2007-01-01

    The temporomandibular joint has a key role in the biocybernetic functional cycle of the orofacial system. It has developed as a "secondary joint" and displays a number of features relating to the articular tubercle, the mandibular condyle, the articular disc, the joint cartilage and the retroarticular pad. The joint cartilage of the mandibular condyle is a primary compensatory growth centre also comprising distant effects. The coordinate course of the mandibular movements is controlled by a complex reflex mechanism and neuronal controller cycles. Morphology, function and clinical aspects are of equal interest to both physicians and dentists.

  1. Leaf morphology of 40 evergreen and deciduous broadleaved subtropical tree species and relationships to functional ecophysiological traits.

    PubMed

    Kröber, W; Heklau, H; Bruelheide, H

    2015-03-01

    We explored potential of morphological and anatomical leaf traits for predicting ecophysiological key functions in subtropical trees. We asked whether the ecophysiological parameters stomatal conductance and xylem cavitation vulnerability could be predicted from microscopy leaf traits. We investigated 21 deciduous and 19 evergreen subtropical tree species, using individuals of the same age and from the same environment in the Biodiversity-Ecosystem Functioning experiment at Jiangxi (BEF-China). Information-theoretic linear model selection was used to identify the best combination of morphological and anatomical predictors for ecophysiological functions. Leaf anatomy and morphology strongly depended on leaf habit. Evergreen species tended to have thicker leaves, thicker spongy and palisade mesophyll, more palisade mesophyll layers and a thicker subepidermis. Over 50% of all evergreen species had leaves with multi-layered palisade parenchyma, while only one deciduous species (Koelreuteria bipinnata) had this. Interactions with leaf habit were also included in best multi-predictor models for stomatal conductance (gs ) and xylem cavitation vulnerability. In addition, maximum gs was positively related to log ratio of palisade to spongy mesophyll thickness. Vapour pressure deficit (vpd) for maximum gs increased with the log ratio of palisade to spongy mesophyll thickness in species having leaves with papillae. In contrast, maximum specific hydraulic conductivity and xylem pressure at which 50% loss of maximum specific xylem hydraulic conductivity occurred (Ψ50 ) were best predicted by leaf habit and density of spongy parenchyma. Evergreen species had lower Ψ50 values and lower maximum xylem hydraulic conductivities. As hydraulic leaf and wood characteristics were reflected in structural leaf traits, there is high potential for identifying further linkages between morphological and anatomical leaf traits and ecophysiological responses.

  2. Whey protein nanofibrils: the environment-morphology-functionality relationship in lyophilization, rehydration, and seeding.

    PubMed

    Loveday, Simon M; Su, Jiahong; Rao, M Anandha; Anema, Skelte G; Singh, Harjinder

    2012-05-23

    Amyloid-like fibrils from β-lactoglobulin have potential as efficient thickening and gelling agents for food and biomedical applications, but the link between fibril morphology and bulk viscosity is poorly understood. We examined how lyophilization and rehydration affects the morphology and rheological properties of semiflexible (i.e., straight) and highly flexible (i.e., curly) fibrils, the latter made with 80 mM CaCl(2). Straight fibrils were fractured into short rods by lyophilization and rehydration, whereas curly fibrils sustained little damage. This was reflected in the viscosities of rehydrated fibril dispersions, which were much lower for straight fibrils than for curly fibrils. Lyophilized straight or curly fibrils seeded new fibril growth, but viscosity enhancement due to seeding was negligible. We believe that the increase in fibril concentration caused by seeding was counterbalanced by a decrease in fibril length, reducing the ability of fibrils to form physical entanglement networks.

  3. Investigation of dynamic morphological changes of cancer cells during photoimmuno therapy (PIT) by low-coherence quantitative phase microscopy

    NASA Astrophysics Data System (ADS)

    Ogawa, Mikako; Yamauchi, Toyohiko; Iwai, Hidenao; Magata, Yasuhiro; Choyke, Peter L.; Kobayashi, Hisataka

    2014-03-01

    We have reported a new molecular-targeted cancer phototherapy, photoimmunotherapy (PIT), which killed implanted tumors in mice without side-effects. To understand the mechanism of cell killing with PIT, three-dimentional dynamic low-coherence quantitative phase microscopy (3D LC-QPM), a device developed by Hamamatsu Photonics K.K, was used to detect morphologic changes in cancer cells during PIT. 3T3/HER2 cells were incubated with anti-HER2 trastuzumab-IR700 (10 μg/mL, 0.1 μM as IR700) for 24 hours, then, three-dimensionally imaged with the LC-QPM during the exposure of two different optically filtered lights for excitation of IR700 (500-780 nm) and imaging (780-950 nm). For comparison with traditional PDT, the same experiments were performed with Photofrin (10 and 1 μM). Serial changes in the cell membrane were readily visualized on 3D LC-QPM. 3T3/HER2 cells began to swell rapidly after exposure to 500-780 nm light excitation. The cell volume reached a maximum within 1 min after continuous exposure, and then the cells appeared to burst. This finding suggests that PIT damages the cell membrane by photo-reaction inducing an influx of water into the cell causing swelling and bursting of the cells. Interestingly, even after only 5 seconds of light exposure, the cells demonstrated swelling and bursting albeit more slowly, implying that sufficient cumulative damage occurs on the cell membrane to induce lethal damage to cells even at minimal light exposure. Similar but non-selective membrane damage was shown in PDT-treated cells Photofrin. Thus, PIT induces sufficient damage to the cell membrane within 5 seconds to induce rapid necrotic cell death which can be observed directly with 3D LC-QPM. Further investigation is needed to evaluate the biochemical mechanisms underlying PIT-induced cellular membrane damage.

  4. Moving through the phase diagram: morphology formation in solution cast polymer-fullerene blend films for organic solar cells.

    PubMed

    Schmidt-Hansberg, Benjamin; Sanyal, Monamie; Klein, Michael F G; Pfaff, Marina; Schnabel, Natalie; Jaiser, Stefan; Vorobiev, Alexei; Müller, Erich; Colsmann, Alexander; Scharfer, Philip; Gerthsen, Dagmar; Lemmer, Uli; Barrena, Esther; Schabel, Wilhelm

    2011-11-22

    The efficiency of organic bulk heterojunction solar cells strongly depends on the multiscale morphology of the interpenetrating polymer-fullerene network. Understanding the molecular assembly and the identification of influencing parameters is essential for a systematic optimization of such devices. Here, we investigate the molecular ordering during the drying of doctor-bladed polymer-fullerene blends on PEDOT:PSS-coated substrates simultaneously using in situ grazing incidence X-ray diffraction (GIXD) and laser reflectometry. In the process of blend crystallization, we observe the nucleation of well-aligned P3HT crystallites in edge-on orientation at the interface at the instant when P3HT solubility is crossed. A comparison of the real-time GIXD study at ternary blends with the binary phase diagrams of the drying blend film gives evidence of strong polymer-fullerene interactions that impede the crystal growth of PCBM, resulting in the aggregation of PCBM in the final drying stage. A systematic dependence of the film roughness on the drying time after crossing P3HT solubility has been shown. The highest efficiencies have been observed for slow drying at low temperatures which showed the strongest P3HT interchain π-π-ordering along the substrate surface. By adding the "unfriendly" solvent cyclohexanone to a chlorobenzene solution of P3HT:PCBM, the solubility can be crossed prior to the drying process. Such solutions exhibit randomly orientated crystalline structures in the freshly cast film which results in a large crystalline orientation distribution in the dry film that has been shown to be beneficial for solar cell performance.

  5. Gravitational environment produced by a superconducting magnet affects osteoblast morphology and functions

    NASA Astrophysics Data System (ADS)

    Qian, Airong; Zhang, Wei; Weng, Yuanyuan; Tian, Zongcheng; Di, Shengmeng; Yang, Pengfei; Yin, Dachuan; Hu, Lifang; Wang, Zhe; Xu, Huiyun; Shang, Peng

    The aims of this study are to investigate the effects of gravitational environment produced by a superconducting magnet on osteoblast morphology, proliferation and adhesion. A superconducting magnet which can produce large gradient high magnetic field (LGHMF) and provide three apparent gravity levels (0g,1gand2g) was employed to simulate space gravity environment. The effects of LGHMF on osteoblast morphology, proliferation, adhesion and the gene expression of fibronectin and collagen I were detected by scanning electron microscopy, immunocytochemistry, adhesion assays and real time PCR, respectively, after exposure of osteoblasts to LGHMF for 24 h. Osteoblast morphology was affected by LGHMF (0g,1gand2g) and the most evident morphology alteration was observed at 0g condition. Proliferative abilities of MC3T3 and MG-63 cell were affected under LGHMF (0g,1gand2g) conditions compared to control condition. The adhesive abilities of MC3T3 and MG-63 cells to extracellular matrix (ECM) proteins (fibronectin, laminin, collagen IV) were also affected by LGHMF (0g,1gand2g), moreover, the effects of LGHMF on osteoblast adhesion to different ECM proteins were different. Fibronectin gene expression in MG63 cells under zero gravity condition was increased significantly compared to other conditions. Collagen I gene expression in MG-63 and MC3T3 cells was altered by both magnetic field and alerted gravity. The study indicates that the superconducting magnet which can produce LGHMF may be a novel ground-based space gravity simulator and can be used for biological experiment at cellular level.

  6. Beneficial effects of ventromedial hypothalamus (VMH) lesioning on function and morphology of the liver after hepatectomy in rats.

    PubMed

    Lee, Eun Young; Inoue, Shuji; Senoo, Akira; Shimizu, Hiroyuki; Suzuki, Yoko; Ishizuka, Noriko; Imazeki, Nobuo; Sasaki, Kahoru; Kako, Masako; Osaka, Toshimasa; Miki, Takashi

    2011-11-03

    Liver has a high regenerative capacity and restores its mass and function shortly after partial hepatectomy through increased proliferation and metabolic modification of hepatocytes. The proliferation of hepatocytes can be triggered by its mass reduction after hepatectomy or by the neural factors including lesioning of the ventromedial hypothalamus (VMH). In the present study, we examined the effect of VMH lesioning on liver regeneration in hepatectomized rats by evaluating liver function and morphology. We found that functional deficits caused by partial hepatectomy [prolonged prothrombin time (PT), increased indocyanine green (ICG) retention, and decrease in PAS (periodic Acid-Schiff staining)-positive hepatocytes] were restored by VMH lesioning at 1 week after the surgery, whereas these alterations disappeared at 4 weeks. Morphologically, lipid microdroplets, which are considered to be important for maintaining contiguous liver function via supplying fuel for cell proliferation, were found to accumulate in hepatocytes of the hepatectomized rats at early period (1 day) after partial hepatectomy. Interestingly, such lipid microdroplets were also detected in the VMH lesioned rats and the more abundantly in the VMH lesioned, hepatectomized rats up to 1 week after the surgery. In conclusion, our results suggest that VMH lesioning in rats promotes recovery of liver anatomically and functionally after partial hepatectomy by promoting cell proliferation process.

  7. The comparative morphology of the cerebellum in caprimulgiform birds: evolutionary and functional implications.

    PubMed

    Iwaniuk, Andrew N; Hurd, Peter L; Wylie, Douglas R W

    2006-01-01

    Interspecific variation in the structure of the avian cerebellum is poorly understood. We present the first comparison of cerebellar morphology within the avian order Caprimulgiformes. Using a range of qualitative descriptions and quantitative measurements of cerebellar morphology we compared caprimulgiform birds with hummingbirds and swifts (Apodiformes) and owls (Strigiformes), two groups that are putative sister taxa to the Caprimulgiformes. Our results demonstrate that the owlet-nightjars (Aegothelidae), nightjars (Caprimulgidae) and potoos (Nyctibiidae) are more similar to apodiforms than they are to other taxa. All of these species have a reduced anterior lobe characterized by particularly small folia II and III and a relatively large posterior lobe. The frogmouths (Podargidae) possess a markedly different cerebellum that is more similar to that of owls than any of the caprimulgiform or apodiform birds. The monotypic oilbird (Steatornis caripensis, Steatornithidae) possesses a cerebellum with some nightjar-like features and some owl-like features, but overall it too resembles an owl more than a nightjar. This cerebellar diversity within the order Caprimulgiformes has significant implications for understanding the evolutionary relationships within the order, how the avian cerebellum has evolved and whether interspecific differences in cerebellar morphology reflect behavior.

  8. From the Weyl quantization of a particle on the circle to number–phase Wigner functions

    SciTech Connect

    Przanowski, Maciej Brzykcy, Przemysław Tosiek, Jaromir

    2014-12-15

    A generalized Weyl quantization formalism for a particle on the circle is shown to supply an effective method for defining the number–phase Wigner function in quantum optics. A Wigner function for the state ϱ{sup ^} and the kernel K for a particle on the circle is defined and its properties are analysed. Then it is shown how this Wigner function can be easily modified to give the number–phase Wigner function in quantum optics. Some examples of such number–phase Wigner functions are considered.

  9. Reconsideration of Plant Morphological Traits: From a Structure-Based Perspective to a Function-Based Evolutionary Perspective

    PubMed Central

    Bai, Shu-Nong

    2017-01-01

    This opinion article proposes a novel alignment of traits in plant morphogenesis from a function-based evolutionary perspective. As a member species of the ecosystem on Earth, we human beings view our neighbor organisms from our own sensing system. We tend to distinguish forms and structures (i.e., “morphological traits”) mainly through vision. Traditionally, a plant was considered to be consisted of three parts, i.e., the shoot, the leaves, and the root. Based on such a “structure-based perspective,” evolutionary analyses or comparisons across species were made on particular parts or their derived structures. So far no conceptual framework has been established to incorporate the morphological traits of all three land plant phyta, i.e., bryophyta, pteridophyta and spermatophyta, for evolutionary developmental analysis. Using the tenets of the recently proposed concept of sexual reproduction cycle, the major morphological traits of land plants can be aligned into five categories from a function-based evolutionary perspective. From this perspective, and the resulting alignment, a new conceptual framework emerges, called “Plant Morphogenesis 123.” This framework views a plant as a colony of integrated plant developmental units that are each produced via one life cycle. This view provided an alternative perspective for evolutionary developmental investigation in plants. PMID:28360919

  10. Reconsideration of Plant Morphological Traits: From a Structure-Based Perspective to a Function-Based Evolutionary Perspective.

    PubMed

    Bai, Shu-Nong

    2017-01-01

    This opinion article proposes a novel alignment of traits in plant morphogenesis from a function-based evolutionary perspective. As a member species of the ecosystem on Earth, we human beings view our neighbor organisms from our own sensing system. We tend to distinguish forms and structures (i.e., "morphological traits") mainly through vision. Traditionally, a plant was considered to be consisted of three parts, i.e., the shoot, the leaves, and the root. Based on such a "structure-based perspective," evolutionary analyses or comparisons across species were made on particular parts or their derived structures. So far no conceptual framework has been established to incorporate the morphological traits of all three land plant phyta, i.e., bryophyta, pteridophyta and spermatophyta, for evolutionary developmental analysis. Using the tenets of the recently proposed concept of sexual reproduction cycle, the major morphological traits of land plants can be aligned into five categories from a function-based evolutionary perspective. From this perspective, and the resulting alignment, a new conceptual framework emerges, called "Plant Morphogenesis 123." This framework views a plant as a colony of integrated plant developmental units that are each produced via one life cycle. This view provided an alternative perspective for evolutionary developmental investigation in plants.

  11. Scanning pattern of diffusion tensor tractography and an analysis of the morphology and function of spinal nerve roots.

    PubMed

    Tian, Xin; Liu, Huaijun; Geng, Zuojun; Yang, Hua; Wang, Guoshi; Yang, Jiping; Wang, Chunxia; Li, Cuining; Li, Ying

    2013-11-25

    Radiculopathy, commonly induced by intervertebral disk bulging or protrusion, is presently diagnosed in accordance with clinical symptoms because there is no objective quantitative diagnostic criterion. Diffusion tensor magnetic resonance imaging and diffusion tensor tractography revealed the characterization of anisotropic diffusion and displayed the anatomic form of nerve root fibers. This study included 18 cases with intervertebral disc degeneration-induced unilateral radiculopathy. Magnetic resonance diffusion tensor imaging was creatively used to reveal the scanning pattern of fiber tracking of the spinal nerve root. A scoring system of nerve root morphology was used to quantitatively assess nerve root morphology and functional alteration after intervertebral disc degeneration. Results showed that after fiber tracking, compared with unaffected nerve root, fiber bundles gathered together and interrupted at the affected side. No significant alteration was detected in the number of fiber bundles, but the cross-sectional area of nerve root fibers was reduced. These results suggest that diffusion tensor magnetic resonance imaging-based tractography can be used to quantitatively evaluate nerve root function according to the area and morphology of fiber bundles of nerve roots.

  12. Synthesis of TiO2 visible light catalysts with controllable crystalline phase and morphology from Ti-bearing electric arc furnace molten slag.

    PubMed

    Li, Yang; Liu, Lulu; Guo, Min; Zhang, Mei

    2016-09-01

    TiO2 visible light catalysts with different crystalline phases and morphologies were synthesized from titanium-bearing electric arc furnace molten slag (Ti-bearing EAF slag) by using a simple acidolysis process. The effects of the pH of the HCl solution, liquid to solid ratio (RL/S, HCl solution to the residue ratio, mL/g) and acidolysis time on the micro-morphology and crystalline phase of as-prepared TiO2 photocatalysts were systematically investigated. The results indicated that with decreasing pH in the HCl solution and increasing RL/S, the crystalline phase and micro-morphology of the obtained TiO2 nanostructures tended to transform from anatase type TiO2 with spherical nanoparticle structures to rutile type TiO2 with needle-like nanorod structures. The acidolysis time had little influence on the crystalline phase but great impact on the size of the obtained TiO2. The growth mechanism of TiO2 from Ti-bearing EAF slag during the acidolysis process was also discussed. In addition, the influence of RL/S on the photocatalytic properties of the synthesized nanostructured TiO2 was studied. The results showed that the photodegradation efficiency for Rhodamine B solution could reach 91.00% in 120min when the RL/S was controlled at 50:1.

  13. Understanding the contribution of phytoplankton phase functions to uncertainties in the water colour signal.

    PubMed

    Lain, Lisl Robertson; Bernard, Stewart; Matthews, Mark W

    2017-02-20

    The accurate description of a water body's volume scattering function (VSF), and hence its phase functions, is critical to the determination of the constituent inherent optical properties (IOPs), the associated spectral water-leaving reflectance, and consequently the retrieval of phytoplankton functional type (PFT) information. The equivalent algal populations (EAP) model has previously been evaluated for phytoplankton-dominated waters, and offers the ability to provide phytoplankton population-specific phase functions, unveiling a new opportunity to further understanding of the causality of the PFT signal. This study presents and evaluates the wavelength dependent, spectrally variable EAP particle phase functions and the subsequent effects on water-leaving reflectance. Comparisons are made with frequently used phase function approximations e.g. the Fournier Forand formulation, as well as with phase functions inferred from measured VSFs in coastal waters. Relative differences in shape and magnitude are quantified. Reflectance modelled with the EAP phase functions is then compared against measured reflectance data from phytoplankton-dominated waters. Further examples of modelled phytoplankton-dominated waters are discussed with reference to choice of phase function for two PFTs (eukaryote and prokaryote) across a range of biomass. Finally a demonstration of the sensitivity of reflectance due to the choice of phase function is presented. The EAP model phase functions account for both spectral and angular variability in phytoplankton backscattering i.e. they display variability which is both spectral and shape-related. It is concluded that phase functions modelled in this way are necessary for investigating the effects of assemblage variability on the ocean colour signal, and should be considered for model closure even in relatively low scattering conditions where phytoplankton dominate the IOPs.

  14. Effect of micro-structural modifier on the morphology of silicon rich secondary phase and strain hardening behavior of eutectic Al-Si alloy

    NASA Astrophysics Data System (ADS)

    Mansoor, M.; Salam, I.; Tauqir, A.

    2016-08-01

    Eutectic Al-Si alloys find their applications in moderate to severe tribological conditions, for example: pistons, casings of high speed pumps and slide sleeves. The higher hardness, so the better tribological properties, are originated by the formation of a silicon rich secondary phase, however, the morphology of the secondary phase drastically influence the toughness of the alloy. Microstructural modifiers are used to control the toughness which modifies the Si rich secondary phase into dispersed spherical structure instead of needle-like network. In the present study, a mixture of chemical fluxes was used to modify the Si phase. The alloy was cast into a sand mold and characterized by scanning electron microscopy, energy dispersive spectroscopy, hardness testing and tensile testing. It was found that the morphology of the Si phase was altered to acicular structure due to the modification process. In comparison, the un-modified alloy contained Si phase in needle-like structure. The effect of modifier was also pronounced on the mechanical properties, where increase of 50% in yield strength, 56% in tensile strength and 200% in elongation occurred. A discernable raise in strain hardening component indicated the improved strain harden ability and formability of the modified alloy.

  15. Dufour's gland possible role in the evolution of sting morphology and function in hover wasps (Hymenoptera Stenogastrinae).

    PubMed

    Fortunato, Angelo; Turillazzi, Stefano

    2012-05-01

    The sting is the most effective defense of social Hymenoptera against vertebrate predators but in the hover wasps (subfamily Stenogastrinae) it is scarcely used. In these wasps a quite enlarged Dufour's gland and the extensive use of its secretion in the peculiar rearing of the larvae and defense determined important morphological modifications of the sting structure. Connecting anatomical and morphological data with behavioral observations we determined that in these wasps the Dufour's gland secretion is attached to the egg during oviposition but can be also channeled to the outside via the sting when it is collected by adult females for larval rearing or construction of the nest ant guards. The anatomical modifications of the sting reduced the function of the sting as a defensive weapon in hover wasps.

  16. Effects of injectable anesthetic combinations on left ventricular function and cardiac morphology in Sprague-Dawley rats.

    PubMed

    Sabatini, Carla F; O'Sullivan, M Lynne; Valcour, James E; Sears, William; Johnson, Ron J

    2013-01-01

    Novel anesthetic agents or combinations may provide superior general anesthesia for echocardiography in rodents with the potential for reduced adverse effects. This study sought to characterize the effects of 3 injectable anesthetics on left ventricular (LV) systolic function and cardiac morphology in healthy male and female rats. Rats underwent echocardiographic assessment after general anesthesia via pentobarbital or combinations of ketamine and medetomidine (KME) and ketamine and midazolam (KMI) according to a crossover Latin-square design. Blood samples for serum estradiol measurements were obtained from all females after echocardiography with each anesthetic. Rats given KMI showed superior LV systolic function with the highest values for fractional shortening (FS), ejection fraction (EF) and stroke volume, whereas heart rate was greatest with pentobarbital, followed by KMI and then KME. KME produced the greatest effects on cardiac morphology, most notably during systole, including reduced septal and posterior wall thickness and increased LV chamber dimensions and volumes. In addition, KME had the greatest cardiac-depressing effects on LV systolic function, including reduced FS, EF, and heart rate values. Compared with male rats, female rats had superior LV function with greater EF and FS values, whereas male rats showed higher heart rate. Significant negative correlations were noted between serum estradiol levels and FS and EF values in female rats receiving KME. We conclude that the combination of KMI may be a superior anesthetic for use in male and female rats undergoing echocardiography.

  17. Analysis of the human female foot in two different measurement systems: from geometric morphometrics to functional morphology.

    PubMed

    Bookstein, Fred L; Domjanić, Jacqueline

    2014-09-01

    The relationship of geometric morphometrics (GMM) to functional analysis of the same morphological resources is currently a topic of active interest among functional morphologists. Although GMM is typically advertised as free of prior assumptions about shape features or morphological theories, it is common for GMM findings to be concordant with findings from studies based on a-priori lists of shape features whenever prior insights or theories have been properly accounted for in the study design. The present paper demonstrates this happy possibility by revisiting a previously published GMM analysis of footprint outlines for which there is also functionally relevant information in the form of a-pri-ori foot measurements. We show how to convert the conventional measurements into the language of shape, thereby affording two parallel statistical analyses. One is the classic multivariate analysis of "shape features", the other the equally classic GMM of semilandmark coordinates. In this example, the two data sets, analyzed by protocols that are remarkably different in both their geometry and their algebra, nevertheless result in one common biometrical summary: wearing high heels is bad for women inasmuch as it leads to the need for orthotic devices to treat the consequently flattened arch. This concordance bears implications for other branches of applied anthropology. To carry out a good biomedical analysis of applied anthropometric data it may not matter whether one uses GMM or instead an adequate assortment of conventional measurements. What matters is whether the conventional measurements have been selected in order to match the natural spectrum of functional variation.

  18. Strong morphological defects in conditional Arabidopsis abp1 knock-down mutants generated in absence of functional ABP1 protein

    PubMed Central

    Perrot-Rechenmann, Catherine; Friml, Jiří

    2016-01-01

    The Auxin Binding Protein 1 (ABP1) is one of the most studied proteins in plants. Since decades ago, it has been the prime receptor candidate for the plant hormone auxin with a plethora of described functions in auxin signaling and development. The developmental importance of ABP1 has recently been questioned by identification of Arabidopsis thaliana abp1 knock-out alleles that show no obvious phenotypes under normal growth conditions. In this study, we examined the contradiction between the normal growth and development of the abp1 knock-outs and the strong morphological defects observed in three different ethanol-inducible abp1 knock-down mutants ( abp1-AS, SS12K, SS12S). By analyzing segregating populations of abp1 knock-out vs. abp1 knock-down crosses we show that the strong morphological defects that were believed to be the result of conditional down-regulation of ABP1 can be reproduced also in the absence of the functional ABP1 protein. This data suggests that the phenotypes in  abp1 knock-down lines are due to the off-target effects and asks for further reflections on the biological function of ABP1 or alternative explanations for the missing phenotypic defects in the abp1 loss-of-function alleles. PMID:26925228

  19. Phase separation kinetics and morphology induced by photopolymerization of 2-hydroxyehyl methacrylate (HEMA) in poly(ethyl acrylate)/HEMA mixtures

    NASA Astrophysics Data System (ADS)

    Van-Pham, Dan-Thuy; Tran-Cong-Miyata, Qui

    2013-03-01

    Morphology and phase separation kinetics induced by polymerization of 2-hydroxyethyl methacrylate (HEMA) in a HEMA/poly(ethyl acrylate) (PEA) mixture were observed by laser scanning confocal microscope in the presence of lucirin TPO used as an initiator. The results were analyzed by 2D-Fourier transform (2D-FFT). The photopolymerization is driven by irradiation with visible light λ = 405 nm. The mixture exhibits the Trommsdorff-Norrish effect which is responsible for a drastic increase in the reaction rate during the irradiation process. The concentration fluctuations and the increase in the viscosity of the medium play an important role in promoting the reaction yield. PHEMA droplets were found to develop in the rhodamine-B-labeled poly(ethyl acrylate) (PEA-Rh) continuous matrix. The characteristic length of the morphology increases with increasing irradiation intensity, revealing the tool to control the morphology by varying the light intensity.

  20. Henyey-Greenstein and Mie phase functions in Monte Carlo radiative transfer computations.

    PubMed

    Toublanc, D

    1996-06-20

    Monte Carlo radiative transfer simulation of light scattering in planetary atmospheres is not a simple problem, especially the study of angular distribution of light intensity. Approximate phase functions such as Henyey-Greenstein, modified Henyey-Greenstein, or Legendre polynomial decomposition are often used to simulate the Mie phase function. An alternative solution using an exact calculation alleviates these approximations.

  1. Henyey-Greenstein and Mie phase functions in Monte Carlo radiative transfer computations

    NASA Astrophysics Data System (ADS)

    Toublanc, Dominique

    1996-06-01

    Monte Carlo radiative transfer simulation of light scattering in planetary atmospheres is not a simple problem, especially the study of angular distribution of light intensity. Approximate phase functions such as Henyey-Greenstein, modified Henyey-Greenstein, or Legendre polynomial decomposition are often used to simulate the Mie phase function. An alternative solution using an exact calculation alleviates these approximations.

  2. Functional morphology of the Alligator mississippiensis larynx with implications for vocal production.

    PubMed

    Riede, Tobias; Li, Zhiheng; Tokuda, Isao T; Farmer, Colleen G

    2015-04-01

    Sauropsid vocalization is mediated by the syrinx in birds and the larynx in extant reptiles; but whereas avian vocal production has received much attention, the vocal mechanism of basal reptilians is poorly understood. The American alligator (Alligator mississippiensis) displays a large vocal repertoire during mating and in parent-offspring interactions. Although vocal outputs of these behaviors have received some attention, the underlying mechanism of sound production remains speculative. Here, we investigate the laryngeal anatomy of juvenile and adult animals by macroscopic and histological methods. Observations of the cartilaginous framework and associated muscles largely corroborate earlier findings, but one muscle, the cricoarytenoideus, exhibits a heretofore unknown extrinsic insertion that has important implications for effective regulation of vocal fold length and tension. Histological investigation of the larynx revealed a layered vocal fold morphology. The thick lamina propria consists of non-homogenous extracellular matrix containing collagen fibers that are tightly packed below the epithelium but loosely organized deep inside the vocal fold. We found few elastic fibers but comparatively high proportions of hyaluronan. Similar organizational complexity is also seen in mammalian vocal folds and the labia of the avian syrinx: convergent morphologies that suggest analogous mechanisms for sound production. In tensile tests, alligator vocal folds demonstrated a linear stress-strain behavior in the low strain region and nonlinear stress responses at strains larger than 15%, which is similar to mammalian vocal fold tissue. We have integrated morphological and physiological data in a two-mass vocal fold model, providing a systematic description of the possible acoustic space that could be available to an alligator larynx. Mapping actual call production onto possible acoustic space validates the model's predictions.

  3. Functional morphology of the olfactory organ of the tongue sole, Cynoglossus semilaevis

    NASA Astrophysics Data System (ADS)

    Ma, Aijun; Wang, Xin'an

    2010-03-01

    The morphology and structure of the olfactory organ of Cynoglossus semilaevis Günther are described. The oval olfactory sacs on both sides differ in size and in the number of lamellae, with those on the abocular side having smaller sacs and fewer lamellae than those on the ocular side. On the ocular side, the average ratio of sac length to eye diameter is 2.1 (i.e.>1) with an average of 91 lamellae, while on the abocular side, the values were 1.7 (i.e.>1) and 69, respectively. In addition, the surface morphology varies in different parts of the lamella. The frontal part, near the anterior nostril, is a non-sensory margin with cilia-free epidermal cells. Within this is an internal ciliated sensory area, which is intercalated with ciliated receptor cells and a few ciliated non-sensory cells. Additionally, some dense ciliated non-sensory cells make up a non-sensory area, which also contains cilia-free epidermal cells distributed in patches. In the rear of the olfactory sac near the posterior nostril, the lamellae differ in morphology from those of the frontal olfactory sac but are similar in having few ciliated receptor cells. In other words, the surface of the lamellae in the rear part of the olfactory sac is mainly non-sensory. At present, four types of lamellae (I, II, III and IV) have been recognized in relation to the pattern of the sensory epithelium. In this study, the frontal and rear lamellae resembled types I and IV, respectively, but are referred to as types I' and IV' because they are slightly less developed. Data on the ratio of length of lamellae to eye diameter, number of lamellae and the type of surface pattern of the lamellae show that the development of the olfactory system of C. semilaevis facilitates prey capture.

  4. Morphological and physiological changes induced by high hydrostatic pressure in exponential- and stationary-phase cells of Escherichia coli: relationship with cell death.

    PubMed

    Mañas, Pilar; Mackey, Bernard M

    2004-03-01

    The relationship between a loss of viability and several morphological and physiological changes was examined with Escherichia coli strain J1 subjected to high-pressure treatment. The pressure resistance of stationary-phase cells was much higher than that of exponential-phase cells, but in both types of cell, aggregation of cytoplasmic proteins and condensation of the nucleoid occurred after treatment at 200 MPa for 8 min. Although gross changes were detected in these cellular structures, they were not related to cell death, at least for stationary-phase cells. In addition to these events, exponential-phase cells showed changes in their cell envelopes that were not seen for stationary-phase cells, namely physical perturbations of the cell envelope structure, a loss of osmotic responsiveness, and a loss of protein and RNA to the extracellular medium. Based on these observations, we propose that exponential-phase cells are inactivated under high pressure by irreversible damage to the cell membrane. In contrast, stationary-phase cells have a cytoplasmic membrane that is robust enough to withstand pressurization up to very intense treatments. The retention of an intact membrane appears to allow the stationary-phase cell to repair gross changes in other cellular structures and to remain viable at pressures that are lethal to exponential-phase cells.

  5. Optimized goniometer for determination of the scattering phase function of suspended particles: simulations and measurements

    NASA Astrophysics Data System (ADS)

    Foschum, Florian; Kienle, Alwin

    2013-08-01

    We present simulations and measurements with an optimized goniometer for determination of the scattering phase function of suspended particles. We applied the Monte Carlo method, using a radially layered cylindrical geometry and mismatched boundary conditions, in order to investigate the influence of reflections caused by the interfaces of the glass cuvette and the scatterer concentration on the accurate determination of the scattering phase function. Based on these simulations we built an apparatus which allows direct measurement of the phase function from ϑ=7 deg to ϑ=172 deg without any need for correction algorithms. Goniometric measurements on polystyrene and SiO2 spheres proved this concept. Using the validated goniometer, we measured the phase function of yeast cells, demonstrating the improvement of the new system compared to standard goniometers. Furthermore, the scattering phase function of different fat emulsions, like Intralipid, was determined precisely.

  6. Identifying the representative flow unit for capillary dominated two-phase flow in porous media using morphology-based pore-scale modeling

    NASA Astrophysics Data System (ADS)

    Mu, Yaoming; Sungkorn, Radompon; Toelke, Jonas

    2016-09-01

    In this paper, we extend pore-morphology-based methods proposed by Hazlett (1995) and Hilpert and Miller (2001) to simulate drainage and imbibition in uniformly wetting porous media and add an (optional) entrapment of the (non-)wetting phase. By improving implementation, this method allows us to identify the statistical representative elementary volume and estimate uncertainty by computing fluid flow properties and saturation distributions of hundreds of subsamples within a reasonable time-frame. The method was utilized to study three different porous medium systems and results demonstrate that morphology-based pore-scale modeling is a viable approach to assess the representative elementary volume with respect to capillary dominated two-phase flow. The focus of this paper is the determination of the representative elementary volume for multiphase-flow properties for a digital representation of a rock.

  7. Impact of Annealing Temperature on the Phase of CZTS with the Variation in Surface Morphological Changes and Extraction of Optical Bandgap

    NASA Astrophysics Data System (ADS)

    Raiguru, J.; Subramanyam, BVRS; Sa, K.; Alam, I.; Das, S.; Mukherjee, J.; Mahakul, P. C.; Subudhi, B.; Mahanandia, P.

    2017-02-01

    Quaternary CZTS (Cu2ZnSnS4) is an emerging alternative semiconductor material for solar cell technologies due to its earth abundancy, low cost and non-toxic nature. In addition, CZTS has a direct band gap of ∼1.5 eV which is the optimal value for converting the maximum amount of energy from the solar spectrum into electricity. The aim of the present study is to investigate the impacts of annealing temperature on the phase formation and morphological behavior of CZTS and material optical characteristics. X-ray Diffraction (XRD) reveals the single phase of kesterite CZTS that has been grown from the material precursors. Scanning electron microscope (SEM) shows the variation of morphological changes of CZTS with respect to annealing temperature. UV-Vis analysis confirms the optical band gap of 1.5 eV in the visible region which is suitable for photovoltaic applications.

  8. Multiple morphologies of gold-magnetite heterostructure nanoparticles are effectively functionalized with protein for cell targeting.

    PubMed

    Krystofiak, Evan S; Mattson, Eric C; Voyles, Paul M; Hirschmugl, Carol J; Albrecht, Ralph M; Gajdardziska-Josifovska, Marija; Oliver, Julie A

    2013-08-01

    Nanoparticles composed of a magnetic iron oxide core surrounded by a metal shell have utility in a broad range of biomedical applications. However, the presence of surface energy differences between the two components makes wetting of oxide with metal unfavorable, precluding a "core-shell" structure of an oxide core completely surrounded by a thin metal shell. Three-dimensional island growth followed by island coalescence into thick shells is favored over the two-dimensional layer-by-layer growth of a thin, continuous metal coating of a true core-shell. Aqueous synthesis of gold-coated magnetite nanoparticles with analysis by infrared, energy-dispersive X-ray, and electron energy loss spectroscopies; high-resolution transmission electron microscopy; selected area electron diffraction; and high-angle annular dark-field scanning transmission electron microscopy showed two distinct morphologies that are inconsistent with an idealized core-shell. The majority were isolated ~16-22-nm-diameter nanoparticles consisting of ~7-nm-diameter magnetite and a thick deposition of gold, most often discontinuous, with some potentially "sandwiched" morphologies. A minority were aggregates of agglomerated magnetite decorated with gold but displaying significant bare magnetite. Both populations were successfully conjugated to fibrinogen and targeted to surface-activated platelets, demonstrating that iron oxide-gold nanoparticles produced by aqueous synthesis do not require an ideal core-shell structure for biological activity in cell labeling and targeting applications.

  9. Morphological changes of gel-type functional polymers after intermatrix synthesis of polymer stabilized silver nanoparticles.

    PubMed

    Bastos-Arrieta, Julio; Muñoz, Maria; Ruiz, Patricia; Muraviev, Dmitri N

    2013-05-29

    This paper reports the results of intermatrix synthesis (IMS) of silver metal nanoparticles (Ag-MNPs) in Purolite C100E sulfonic ion exchange polymer of the gel-type structure. It has been shown that the surface morphology of the initial MNP-free polymer is absolutely smooth, but it dramatically changes after the kinetic loading of Ag on the polymer and then IMS of Ag-MNPs. These morphological changes can be explained by the interaction of Ag-NPs with the polymer chains, leading to a sort of additional cross-linking of the polymer. As a result, the modification of the gel-type matrix with Ag-MNPs leads to the increase of the matrix cross-linking, which results in the increase of its surface area and the appearance of nanoporosity in the polymer gel. Ag-MNPs are located near the polymer surface and do not form any visible agglomerations. All these features of the nanocomposites obtained are important for their practical applications in catalysis, sensor applications, and bactericide water treatment.

  10. Morphological and functional differentiation in BE(2)-M17 human neuroblastoma cells by treatment with Trans-retinoic acid

    PubMed Central

    2013-01-01

    Background Immortalized neuronal cell lines can be induced to differentiate into more mature neurons by adding specific compounds or growth factors to the culture medium. This property makes neuro