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Sample records for phase function morphology

  1. Phase transitions and morphologies of aerosol particles

    NASA Astrophysics Data System (ADS)

    Song, M.; Marcolli, C.; Krieger, U.; Zuend, A.; Peter, T.

    2012-12-01

    Tropospheric aerosol particles consisting of complex mixtures of organic compounds, ammonium sulfate (AS) and water undergo phase transitions such as liquid-liquid phase separation (LLPS), efflorescence and deliquescence as a consequence of changes in ambient relative humidity (RH). These phase transitions in the mixed aerosol particles may lead to different particle configurations such as core-shell or partially engulfed structures. However, the physical states and morphologies of these aerosol particles are still poorly understood. In this study, we investigate the phase transitions and morphological changes of various internally mixed organics/AS/water particles with different organic-to-inorganic ratios (OIR), namely OIR = 6:1, 2:1, 1:2 and 1:6 during humidity cycles using optical microscopy and Raman spectroscopy. Particularly, we explore how the properties of different organic functional groups and the compositional complexity of the organic aerosol fraction influence the occurrence of LLPS in the relationship with the organic oxygen-to-carbon (O:C) ratios. We found that LLPS occurred for all mixtures with O:C < 0.56, for none of the mixtures with O:C > 0.80, and depended on the specific types and compositions of organic functional groups for 0.56 < O:C < 0.80. Moreover, the number of mixture components and the spread of the O:C range did not notably influence the conditions for LLPS to occur. Since in ambient aerosols O:C and OIR range typically between 0.2 and 1.0, and between 4:1 and 1:5, respectively, LLPS is expected to be a common feature of tropospheric aerosols. AS in the mixed particles effloresced between 0 and 47 %RH and deliquesced between 71 and 80 %RH during humidity cycles. Compared to a deliquescence relative humidity (DRH) of 80 % for pure AS, the DRH in the mixed particles showed slightly lower values. A strong reduction or complete inhibition of efflorescence occurred for mixtures with high OIR that did not exhibit LLPS. Both core-shell and

  2. Phase separation in biopolymer gels: a low- to high-solid exploration of structural morphology and functionality.

    PubMed

    Kasapis, Stefan

    2008-04-01

    Phase separation in protein and polysaccharide gels remains one of the basic tools of achieving the required structural properties and textural profile in food product formulations. As ever, the industrialist is faced with the challenge of innovation in an increasingly competitive market in terms of ingredient cost, product added-value, and expectations of a healthy life-style to mention but a few. It appears, however, that a gap persists between the fundamental knowledge and a direct application to food related concepts with a growing need for scientific input. Furthermore, within the context of materials science, there is a tendency to examine research findings in either low- or high-solid systems without considering synergistic insights/benefits to contemporary needs, spanning the full range of relevant time-, length-, and concentration scales. This review highlights the latest attempts made to utilize and further develop fundamental protocols from the advanced synthetic polymer research as a source of inspiration for contemporary bio-related applications in low- and intermediate-solid composite gels. Then, it takes advantage of this school of thought to "force a passage" through the phase topology and molecular dynamics of binary biopolymer mixtures at high levels of co-solute. It is hoped that these phenomenological and fundamental tools should be able to bridge the divide in the analysis of the two "types" of composite materials (from low to high solids) thus dealing effectively with the specific and often intricate problems of their science and applications. PMID:18409116

  3. [Functional morphology of stomach secretions].

    PubMed

    Liebich, H G

    1985-01-01

    The stimulation of gastric secretion is regulated by neurovagal, endocrine and immunological reactions. During the gastric phase of digestion, especially acetylcholin, gastrin and histamin react as main transmitters, activated by mediators (prostaglandines, leucotrienes, lipoxygenases). The dominant role of nervus vagus has to be seen in the transactions of vago-vagal reflexes, the stimulation of gastrin liberation by an non-cholinergic mechanism and the regulation of the gastric microcirculation. The antrum pylori can be seen as an immunological area of reception, where immunological active cells (macrophages, NK-lymphocytes and T-lymphocytes) are recognizing antigens (e.g. food antigens). These immunocytes induce a cascade of endocrine and exocrine mechanisms of digestion. Mastcells, located intra-and extraepithelial, take a regulatory influence in producing histamins, leucotrienes and also prostaglandines.

  4. [Morphological variability and placental function].

    PubMed

    Malassiné, A

    2001-01-01

    In mammals, the blastocyst defines with the maternal organism, a structure which allows embryonic development during gestation: the placenta. The structure of this organ varies remarkably across species. In this review the different type of placentation have been described in a comparative manner using terms of classification such as: placental materno-fetal interdigitation, matemofetal blood flow interrelationships, layers of the placental interhemal barrier, trophoblast invasiveness and decidual cell reaction, formation of syncytiotrophoblast. The human hemomonochorial placenta is characterized by a strong decidualization of the uterus and a major invasiveness of the extravillous trophoblast. Furthermore, there is a spectrum of placental endocrine activities across species. In some mammals (e.g., mouse and rat) the placenta eclipses the pituitary in the maintenance of ovarian function. In the human and in the sheep, horse, cat and guinea pig, the placenta acquires the ability to substitute for the ovaries in the maintenance of gestation at various time during pregnancy. The human placenta is characterized by a high rate of steroïdogenesis (progesterone and estrogens) and by the production of a primate specific trophoblastic hormone: human chorionic gonadotropin (hCG). Recently, it was demonstrated that mutation of many genes in mice results in embryonic mortality or fetal growth restriction, due to defects in placental development. Furthermore, distinct molecular pathways regulate the differentiation of various trophoblast cell subtype of the mouse placenta. An important question is whether or not placental differentiation in other mammals is regulated by the same molecular mechanisms. Due to the striking diversity in placental structure, endocrine function and gene expression, caution must be exercised in extrapolating findings regarding placental function and development from one species to another. PMID:11575143

  5. [Functional morphology of endonasal blood capillaries].

    PubMed

    Grevers, G

    1989-01-01

    Harvey (1628) was the first to describe the blood circulatory system. 50 years later, the capillary system was discovered by Marcello Malpighi as a link between arteries and veins. Since then, the microvascular network has been examined abundantly by means of various morphological and physiological techniques. During the last decades the development of the technical equipment enabled us to receive detailed informations on the structural and ultrastructural aspects of the vasculature and--particularly--the capillary endothelium. New electron microscopic investigations on the behaviour of this special cell system. In the present study we combined our own morphological results on the endonasal microcirculatory system--using different morphological techniques--to interpret these anatomical finding under functional aspects.

  6. Morphologies of aerosol particles consisting of two liquid phases

    NASA Astrophysics Data System (ADS)

    Song, Mijung; Marcolli, Claudia; Krieger, Ulrich; Peter, Thomas

    2013-04-01

    Recent studies have shown that liquid-liquid phase separation (LLPS) might be a common feature in mixed organic/ammonium sulfate (AS)/H2O particles. Song et al. (2012) observed that in atmospheric relevant organic/AS/H2O mixtures LLPS always occurred for organic aerosol compositions with O:C < 0.56, depended on the specific functional groups of organics in the range of 0.56 < O:C < 0.80 and never appeared for O:C > 0.80. The composition of the organic fraction and the mixing state of aerosol particles may influence deliquescence relative humidity (DRH) and efflorescence relative humidity (ERH) of inorganic salts during RH cycles and also aerosol morphology. In order to determine how the deliquescence and efflorescence of AS in mixed organic/AS/H2O particles is influenced by LLPS and to identify the corresponding morphologies of the particles, we subjected organic/AS/H2O particles deposited on a hydrophobically coated substrate to RH cycles and observed the phase transitions using optical microscopy and Raman spectroscopy. In this study, we report results from 21 organic/AS/H2O systems with O:C ranging from 0.55 - 0.85 covering aliphatic and aromatic oxidized compounds. Eight systems did not show LLPS for all investigated organic-to-inorganic ratios, nine showed core-shell morphology when present in a two-liquid-phases state and four showed both, core-shell or partially engulfed configurations depending on the organic-to-inorganic ratio. While AS in aerosol particles with complete LLPS showed almost constant values of ERH = 44 ± 4 % and DRH = 77 ± 2 %, a strong reduction or complete inhibition of efflorescence occurred for mixtures that did not exhibit LLPS. To confirm these findings, we performed supplementary experiments on levitated particles in an electrodynamic balance and compared surface and interfacial tensions of the investigated mixtures. Reference Song, M., C. Marcolli, U. K. Krieger, A. Zuend, and T. Peter (2012), Liquid-liquid phase separation in

  7. Judgment of functional morphology in agrammatic aphasia

    PubMed Central

    Dickey, Michael Walsh; Milman, Lisa H.; Thompson, Cynthia K.

    2008-01-01

    Individuals with agrammatic Broca’s aphasia show deficits in production of functional morphemes like complementizers (e.g., that and if) and tense and agreement markers (e.g., –ed and –s), with complementizers often being more impaired than verbal morphology. However, there has been comparatively little work examining patients’ ability to comprehend or judge the grammaticality of these morphemes. This paper investigates comprehension of complementizers and verb inflections in two timed grammaticality-judgment experiments. In Experiment 1, participants with agrammatic Broca’s aphasia and grammatical-morphology production deficits (n=10) and unimpaired controls (n=10) heard complement clause sentences, subject relative clause sentences, and conjoined sentences. In Experiment 2, the same participants heard sentences with finite auxiliaries, sentences with finite main verbs, and sentences with uninflected verbs. Results showed above-chance accuracy in aphasic participants’ judgments for complementizer sentences in Experiment 1, but chance performance for verb inflections in Experiment 2. This pattern held regardless of whether the verb inflections were affixes or free-standing auxiliaries. Implications of these results for theories of agrammatic morphological impairments, including feature underspecification accounts (Wenzlaff & Clahsen, 2004; Burchert, Swoboda-Moll & DeBleser, 2005a) and hierarchical structure-based accounts (Friedmann & Grodzinsky, 1997; Izvorski & Ullman, 1999), are discussed. PMID:18438453

  8. Functional morphology of the suprachiasmatic nucleus.

    PubMed

    Ibata, Y; Okamura, H; Tanaka, M; Tamada, Y; Hayashi, S; Iijima, N; Matsuda, T; Munekawa, K; Takamatsu, T; Hisa, Y; Shigeyoshi, Y; Amaya, F

    1999-07-01

    In mammals, the biological clock (circadian oscillator) is situated in the suprachiasmatic nucleus (SCN), a small bilaterally paired structure just above the optic chiasm. Circadian rhythms of sleep-wakefulness and hormone release disappear when the SCN is destroyed, and transplantation of fetal or neonatal SCN into an arrhythmic host restores rhythmicity. There are several kinds of peptide-synthesizing neurons in the SCN, with vasoactive intestinal peptide, arginine vasopressin, and somatostatine neurons being most prominent. Those peptides and their mRNA show diurnal rhythmicity and may or may not be affected by light stimuli. Major neuronal inputs from retinal ganglion cells as well as other inputs such as those from the lateral geniculate nucleus and raphe nucleus are very important for entrainment and shift of circadian rhythms. In this review, we describe morphological and functional interactions between neurons and glial elements and their development. We also consider the expression of immediate-early genes in the SCN after light stimulation during subjective night and their role in the mechanism of signal transduction. The reciprocal interaction between the SCN and melatonin, which is synthesized in the pineal body under the influence of polysynaptic inputs from the SCN, is also considered. Finally, morphological and functional characteristics of clock genes, particularly mPers, which are considered to promote circadian rhythm, are reviewed. PMID:10433864

  9. Morphology of electrospun fibers derived from High Internal Phase Emulsions.

    PubMed

    Samanta, Archana; Nandan, Bhanu; Srivastava, Rajiv K

    2016-06-01

    High Internal Phase Emulsions (HIPEs) are known for their excessive volume of dispersed phase (volume fraction of dispersed phase Φd>0.74) and are primarily used for polymerization of continuous phase monomer(s) thereby generating porous systems in a single step. In the present work, electrospinning of HIPEs formed from aqueous solution of poly(vinyl alcohol) (PVA) dispersed in continuous phase comprised of poly(ε-caprolactone) (PCL) solution in toluene is conducted. Effect of variation in volume fraction of dispersed and continuous phase on fiber morphology was studied. Fibers of co-continuous morphology were obtained due to coalescence and dielectrophoresis of the higher electrically conducting dispersed aqueous phase than toluene containing continuous phase. Removal of PVA was later done by washing of fibers with water to evaluate the presence of two phases in the fibers and relate it to original HIPE morphology of the emulsions. Heterogeneous and surface nucleation of PCL and Brij-58 confined within electrospun fibers of HIPEs was studied in detail and related to the original HIPE structure.

  10. Temperature dependence of emulsion morphologies and the dispersion morphology diagram for three-phase emulsions

    SciTech Connect

    Smith, D.H.; Johnson, G.K.

    1995-12-31

    Using several different compositions of the (pseudo)ternary amphiphile/oil/{open_quotes}water{close_quotes} system C{sub 6}H{sub 13}(OC{sub 2}H{sub 4}){sub 2}OH/n-tetradecane/aqueous 10 mM NaCl that form oil-rich top phases (J), water-rich bottom phases ({Beta}), and middle-phase microemulsions (m), we showed by means of electrical conductivity measurements that the temperature dependencies of the three-phase emulsion morphologies were consistent with predictions from isothermal dispersion morphology diagrams, thus contradicting ideas derived from the PIT (phase inversion temperature) model for two-phase emulsions. In particular, we formed three-phase emulsions in which either (1) the continuous phase was an oil-rich phase (actually, m) below the PIT and the water-rich phase ({Beta}) above that temperature; (2) the water-rich phase was continuous both below and above the PIT; or (3) oil-rich phase was the continuous phase both below and above the PIT.

  11. Temperature dependence of emulsion morphologies and the dispersion morphology diagram. 2. Three-phase emulsions

    SciTech Connect

    Smith, D.H.; Johnson, G.K.

    1995-07-06

    Using several different compositions of the (pseudo)ternary amphiphile/oil/`water` system C{sub 6}H{sub 13}(OC{sub 2}H{sub 4}){sub 2}-OH/n-tetradecane/aqueous 10 mM NaCl, we show by means of electrical conductivity measurements that the temperature dependencies of the emulsion morphologies were consistent with predictions from isothermal dispersion morphology diagrams, thus contradicting phase inversion temperature ideas. 26 refs., 8 figs.

  12. 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.

  13. 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.

  14. 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.

  15. Functional impact of dendritic branch point morphology

    PubMed Central

    Ferrante, Michele; Migliore, Michele; Ascoli, Giorgio A.

    2013-01-01

    Cortical pyramidal cells store multiple features of complex synaptic input in individual dendritic branches and independently regulate the coupling between dendritic and somatic spikes. Branch points in apical trees exhibit wide ranges of sizes and shapes, and the large diameter ratio between trunk and oblique dendrites exacerbates impedance mismatch. The morphological diversity of dendritic bifurcations could thus locally tune neuronal excitability and signal integration. However, these aspects have never been investigated. Here, we first quantified the morphological variability of branch points from two-photon images of rat CA1 pyramidal neurons. We then investigated the geometrical features affecting spike initiation, propagation, and timing with a computational model validated by glutamate uncaging experiments. The results suggest that even subtle membrane readjustments at branch point could drastically alter the ability of synaptic input to generate, propagate, and time action potentials. PMID:23365251

  16. Unique nanoscale morphologies underpinning organic gel-phase materials.

    PubMed

    Hirst, Andrew R; Smith, David K; Harrington, John P

    2005-11-01

    This study investigates the self-assembly of simple aliphatic diamines with a dendritic peptide. By controlling the molar ratio of this two-component system, new nanoscale morphologies were generated. In the presence of relatively long aliphatic chains (C10, C12) a transition from nanoscale fibres to platelets was observed on changing the molar ratio, whereas, for shorter spacer chains (e.g., C9 and C8), interesting and unique morphological changes were observed by low voltage field emission gun scanning electron microscopy (SEM), with "nanosquares" or nanoscale "rosette" structures being formed. Remarkably, these discrete nanoscale structures were able to form sample-spanning networks capable of supporting a gel-phase material; whereas, most gels are usually based on fibrillar assemblies. In addition to SEM, the gels were characterised by using thermal measurements and circular dichroism spectroscopy. The length of the diamine spacer and the molar ratio of components controlled the self-assembly process by modifying the spatial organisation of the dendritic head groups at the molecular level, which is transcribed into the aspect ratio of the self-assembled state at the microscopic level. Ultimately, this led to diamine-induced control of the macroscopic material's behaviour. When present in excess, the diamine controlled the observed nanoscale morphology as a consequence of undergoing a dendritically controlled nanocrystallisation process to form a network, an unusual and significant result.

  17. 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.

  18. 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.

  19. Functional morphology of the aardvark tail.

    PubMed

    Endo, H; Mori, K; Koyabu, D; Kawada, S; Komiya, T; Itou, T; Koie, H; Kitagawa, M; Sakai, T

    2013-04-01

    The musculoskeletal system of the aardvark (Orycteropus afer) tail was morphologically examined in two adult specimens. The tail musculature comprised three muscular groups, viz. a dorsal sacrocaudal system that consisted of the irregularly oriented Musculus sacrocaudalis dorsalis medialis and M. sacrocaudalis dorsalis lateralis, a lateral inter-vertebral connecting system, and a ventral sacrocaudal system characterized by the thick M. sacrocaudalis ventralis lateralis and M. sacrocaudalis ventralis medialis. Both the dorsal and ventral systems possessed large tendon groups that strengthened the tail structure. Computed tomography (CT) examination showed the presence of large but homogeneous cartilaginous inter-vertebral discs, whereas V-shaped bones were situated at the ventral aspect of the caudal vertebrae at the level of the inter-vertebral discs. CT visualization of the tendons and V-shaped bones in various tail positions suggested that these structures contribute to the tunnel digging action by bearing the trunk weight and lending force when the aardvark are displacing the soil by means of the forelimbs.

  20. 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

  1. 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

  2. Solid state protein monolayers: Morphological, conformational, and functional properties

    NASA Astrophysics Data System (ADS)

    Pompa, P. P.; Biasco, A.; Frascerra, V.; Calabi, F.; Cingolani, R.; Rinaldi, R.; Verbeet, M. Ph.; de Waal, E.; Canters, G. W.

    2004-12-01

    We have studied the morphological, conformational, and electron-transfer (ET) function of the metalloprotein azurin in the solid state, by a combination of physical investigation methods, namely atomic force microscopy, intrinsic fluorescence spectroscopy, and scanning tunneling microscopy. We demonstrate that a "solid state protein film" maintains its nativelike conformation and ET function, even after removal of the aqueous solvent.

  3. 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.

  4. The association between functional and morphological assessments of endothelial function in patients with rheumatoid arthritis: a cross-sectional study

    PubMed Central

    2013-01-01

    Introduction Patients with rheumatoid arthritis (RA) are at an increased risk for cardiovascular disease (CVD). One of the earliest manifestations of CVD is endothelial dysfunction (ED), which can lead to functional and morphological vascular abnormalities. Several non-invasive assessments of vascular function and morphology can be utilised to assess vascular health, but little is known about the association between each of these assessments in patients with RA, and they tend to be used interchangeably in the literature. The objective of the present study was to examine associations between measures of vascular function and morphology in patients with RA. Methods A total of 201 RA patients (155 females, median (25th to 75th percentile) age: 67 (59 to 73)) underwent assessments of microvascular endothelium-dependent and endothelium-independent function (laser Doppler imaging with iontophoresis of acetylcholine and sodium-nitroprusside respectively), macrovascular endothelium-dependent and endothelium-independent function (flow-mediated dilatation and glyceryl-trinitrate-mediated dilation respectively), and vascular morphology (pulse wave analysis, carotid intima-media thickness (cIMT), and carotid plaque). Results Spearman's correlations revealed that from the functional parameters, only macrovascular endothelium-independent function was inversely associated with cIMT (-0.294 (P < 0.001)) after applying the Bonferroni correction for multiple comparisons. For carotid plaque, t tests showed that macrovascular endothelium-independent function was lower in patients with plaque than without (15.5 ± 8.3 vs. 23.1 ± 9.1%, P = 0.002, respectively). Conclusions With the exception of macrovascular endothelium-independent function, all other measures of vascular function were not associated with vascular morphology. This suggests that different assessments of vascular function and morphology in patients with RA reflect quite distinct mechanisms and phases of the

  5. Morphological and phase characterizations of retrieved calcium phosphate cement implants.

    PubMed

    Takagi, S; Chow, L C; Markovic, M; Friedman, C D; Costantino, P D

    2001-01-01

    A self-hardening calcium phosphate cement (CPC), consisting of equimolar amounts of tetracalcium phosphate and dicalcium phosphate anhydrous, hardens when mixed with water and forms a resorbable hydroxyapatite (HA) as the end-product. The objective of this study was to investigate the changes of the phase and morphology of the CPC during hardening and aging under in vivo conditions. CPC samples retrieved 12 h after hardening in vivo had already contained carbonated HA (type B), even though the initial cement mixture did not contain carbonate as one of the solid components. The mass fraction of carbonate in the 12-h sample was about 1%. The results suggested that under in vivo conditions carbonate is readily available and this allows formation of carbonated HA in favor of carbonate-free HA. The carbonate content of the CPC samples retrieved 3 months after implantation was similar to that of the 12-h samples, and the exterior surfaces of the 3-month samples appeared less crystalline than that of the 12-h samples.

  6. 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

  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

    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

    2014-02-01

    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. 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. Morphology and functional characteristics of isolated porcine intraepithelial lymphocytes.

    PubMed Central

    Wilson, A D; Stokes, C R; Bourne, F J

    1986-01-01

    We have examined the morphology and functional characteristics of porcine intraepithelial lymphocytes (IEL). A subpopulation of IEL contains granules as seen in other species, and their ultrastructure was also similar. They were capable of producing T-cell growth factor and interferon on in vitro stimulation. IEL killed P815 cells in the presence of PHA, but did not kill K562 cells. Images Figure 1 Figure 2 PMID:2428733

  12. Sensitivity analysis of volume scattering phase functions.

    PubMed

    Tuchow, Noah; Broughton, Jennifer; Kudela, Raphael

    2016-08-01

    To solve the radiative transfer equation and relate inherent optical properties (IOPs) to apparent optical properties (AOPs), knowledge of the volume scattering phase function is required. Due to the difficulty of measuring the phase function, it is frequently approximated. We explore the sensitivity of derived AOPs to the phase function parameterization, and compare measured and modeled values of both the AOPs and estimated phase functions using data from Monterey Bay, California during an extreme "red tide" bloom event. Using in situ measurements of absorption and attenuation coefficients, as well as two sets of measurements of the volume scattering function (VSF), we compared output from the Hydrolight radiative transfer model to direct measurements. We found that several common assumptions used in parameterizing the radiative transfer model consistently introduced overestimates of modeled versus measured remote-sensing reflectance values. Phase functions from VSF data derived from measurements at multiple wavelengths and a single scattering single angle significantly overestimated reflectances when using the manufacturer-supplied corrections, but were substantially improved using newly published corrections; phase functions calculated from VSF measurements using three angles and three wavelengths and processed using manufacture-supplied corrections were comparable, demonstrating that reasonable predictions can be made using two commercially available instruments. While other studies have reached similar conclusions, our work extends the analysis to coastal waters dominated by an extreme algal bloom with surface chlorophyll concentrations in excess of 100 mg m-3. PMID:27505819

  13. Advanced Morphological and Functional Magnetic Resonance Techniques in Glaucoma

    PubMed Central

    Mastropasqua, Rodolfo; Agnifili, Luca; Mattei, Peter A.; Caulo, Massimo; Fasanella, Vincenzo; Navarra, Riccardo; Mastropasqua, Leonardo; Marchini, Giorgio

    2015-01-01

    Glaucoma is a multifactorial disease that is the leading cause of irreversible blindness. Recent data documented that glaucoma is not limited to the retinal ganglion cells but that it also extends to the posterior visual pathway. The diagnosis is based on the presence of signs of glaucomatous optic neuropathy and consistent functional visual field alterations. Unfortunately these functional alterations often become evident when a significant amount of the nerve fibers that compose the optic nerve has been irreversibly lost. Advanced morphological and functional magnetic resonance (MR) techniques (morphometry, diffusion tensor imaging, arterial spin labeling, and functional connectivity) may provide a means for observing modifications induced by this fiber loss, within the optic nerve and the visual cortex, in an earlier stage. The aim of this systematic review was to determine if the use of these advanced MR techniques could offer the possibility of diagnosing glaucoma at an earlier stage than that currently possible. PMID:26167474

  14. 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. PMID:25889534

  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. 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.

  17. 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.

  18. Functional constraints on tooth morphology in carnivorous mammals

    PubMed Central

    2012-01-01

    Background The range of potential morphologies resulting from evolution is limited by complex interacting processes, ranging from development to function. Quantifying these interactions is important for understanding adaptation and convergent evolution. Using three-dimensional reconstructions of carnivoran and dasyuromorph tooth rows, we compared statistical models of the relationship between tooth row shape and the opposing tooth row, a static feature, as well as measures of mandibular motion during chewing (occlusion), which are kinetic features. This is a new approach to quantifying functional integration because we use measures of movement and displacement, such as the amount the mandible translates laterally during occlusion, as opposed to conventional morphological measures, such as mandible length and geometric landmarks. By sampling two distantly related groups of ecologically similar mammals, we study carnivorous mammals in general rather than a specific group of mammals. Results Statistical model comparisons demonstrate that the best performing models always include some measure of mandibular motion, indicating that functional and statistical models of tooth shape as purely a function of the opposing tooth row are too simple and that increased model complexity provides a better understanding of tooth form. The predictors of the best performing models always included the opposing tooth row shape and a relative linear measure of mandibular motion. Conclusions Our results provide quantitative support of long-standing hypotheses of tooth row shape as being influenced by mandibular motion in addition to the opposing tooth row. Additionally, this study illustrates the utility and necessity of including kinetic features in analyses of morphological integration. PMID:22899809

  19. [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.

  20. Influence of phase and morphology on thermal conductivity of alumina particle/silicone rubber composites

    NASA Astrophysics Data System (ADS)

    Cheng, J. P.; Liu, T.; Zhang, J.; Wang, B. B.; Ying, J.; Liu, F.; Zhang, X. B.

    2014-12-01

    Silicone rubber filled with thermally conductive alumina is fabricated as a class of thermal interface materials in this work. The thermal conductivity of the prepared alumina/silicone rubber composite is measured as a function of alumina loading. The effects of alumina filler with different phases and morphologies on the thermal conductivity of the composite are investigated by comparative method. When the filler loading is low, the composite filled with porous irregular-shaped α-alumina exhibits a higher thermal conductivity than that filled with γ-Al2O3 and spherical α-Al2O3. In order to achieve a high loading, spherical α-Al2O3 has the most pronounced effect due to its intrinsic high thermal conductivity and unique morphology for homogeneous dispersion in the polymer matrix, which is superior to irregular-shaped α- and γ-Al2O3. Our results demonstrate that the composite filled with spherical alumina by the mass concentration of 82 % has six times thermal conductivity higher than pure silicone rubber. Thermogravimetric analysis studies exhibit that the thermal stability of the composite distinctly increases with filler loadings. The obtained data were compared with theoretical equations in the literatures that are used to predict the properties of two-phase mixtures.

  1. 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

  2. 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

  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. PMID:27457546

  4. 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

  5. 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.

  6. 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.

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

    PubMed

    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

  8. 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

  9. 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

  10. CARDIAC MICRO-CT FOR MORPHOLOGICAL AND FUNCTIONAL PHENOTYPING OF MLP NULL MICE

    PubMed Central

    Badea, Cristian T; Hedlund, Laurence W.; Boslego Mackel, Julie F.; Mao, Lan; Rockman, Howard A.; Johnson, G. Allan

    2009-01-01

    PURPOSE Investigate the use of micro-CT for morphological and functional phenotyping of MLP null mice and compare micro-CT with M-mode echocardiography. MATERIAL AND METHODS MLP null mice and controls were imaged using both micro-CT and M-mode echocardiography. For Micro-CT imaging, we used a custom built scanner. Following a single intravenous injection of a blood pool contrast agent (Fenestra™ VC) and using a cardio-respiratory gating, we acquired eight phases of the cardiac cycle (every 15 ms) and reconstructed 3D datasets with 94 micron isotropic resolution. Wall thickness and volumetric measurements of left ventricle were performed and cardiac function was estimated. RESULTS Micro-CT and M mode echocardiography showed both morphological and functional aspects that separate MLP null mice from controls. End Diastolic and Systolic Volumes were increased significantly 3 and 5 fold respectively in the MLP null versus controls. Ejection Fraction was reduced by an average of 32% in MLP null mice. The data analysis shows that two imaging modalities provided different results partly due to the difference in anesthesia regimes. Other sources of errors for micro-CT are also analyzed. CONCLUSION Micro-CT can provide the 4D data (3D isotropic volumes over time) required for morphological and functional phenotyping in mice. PMID:17711781

  11. 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

  12. Chronic progressive nephropathy: functional, morphological, and morphometrical studies.

    PubMed

    Fiori, Mariana C; Ossani, Georgina P; Lago, Néstor R; Amorena, Carlos; Monserrat, Alberto J

    2010-01-01

    Some aspects of the functional, morphological, and morphometrical characteristics of chronic progressive nephropathy occurring in 18- to 26-month-old male rats and in 3-month-old control rats were studied. Rats with chronic progressive nephropathy were proteinuric and showed a slight increase in serum creatinine and no changes in blood pressure. The morphological changes were studied by light microscopy, high-resolution light microscopy, and electron microscopy. They showed focal and segmental or global glomerulosclerosis, the three types of atrophic tubules ("classic," "thyroid-like," and "endocrine") described by Nadasdy et al, as well as interstitial fibrosis with mononuclear cell infiltrates. On certain occasions, small vessels showed hyalinosis. Glomerular morphometrical studies showed a biphasic pattern in the glomeruli progressing toward obsolescence. Vascular morphometrical studies showed significant increase in media wall thickness and media cross-sectional area in the 18- to 26-month-old rats. These results support the hypothesis that changes in the vascular system are not of utmost importance in the pathogenesis of chronic progressive nephropathy, and that glomerular sequential changes seem to be of paramount significance in the progression of the disease. PMID:20113276

  13. Functional morphology of durophagy in black carp, Mylopharyngodon piceus.

    PubMed

    Gidmark, Nicholas J; Taylor, Chantel; LoPresti, Eric; Brainerd, Elizabeth

    2015-12-01

    The black carp, Mylopharyngodon piceus (Osteichthyes: Cyprinidae), crushes its snail and other molluscan prey with robust pharyngeal jaws and strong bite forces. Using gross morphology, histological sectioning, and X-ray reconstruction of moving morphology (XROMM), we investigated structural, behavioral, and mechanical aspects of pharyngeal jaw function in black carp. Strut-like trabeculae in their pharyngeal jaws support large, molariform teeth. The teeth occlude with a hypertrophied basioccipital process that is also reinforced with stout trabeculae. A keratinous chewing pad is firmly connected to the basioccipital process by a series of small bony projections from the base of the pedestal. The pharyngeal jaws have no bony articulations with the skull, and their position is controlled by five paired muscles and one unpaired median muscle. Black carp can crush large molluscs, so we used XROMM to compare pharyngeal jaw postures as fish crushed ceramic tubes of increasing sizes. We found that black carp increase pharyngeal jaw gape primarily by ventral translation of the jaws, with ventral rotation and lateral flaring of the jaws also increasing the space available to accommodate large prey items. A stout, robust ligament connects left and right jaws together firmly, but allows some rotation of the jaws relative to each other. Contrasting with the pharyngeal jaw mechanism of durophagous perciforms with fused left and right lower pharyngeal jaws, we hypothesize that this ligamentous connection may serve to decouple tensile and compressive forces, with the tensile forces borne by the ligament and the compressive forces transferred to the prey. PMID:26289832

  14. 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.

  15. 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

  16. 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

  17. Morphology and crystalline phase characteristics of α-GST films irradiated by a picosecond laser

    NASA Astrophysics Data System (ADS)

    Zhao, J. J.; Liu, F. R.; Han, X. X.; Bai, N.; Wan, Y. H.; Lin, X.; Liu, F.

    2014-01-01

    The morphology and crystalline phase characteristics of amorphous Ge2Sb2Te5 films irradiated by a picosecond laser were investigated by 3D surface profiler, atomic force microscopy (AFM) and transmission electron microscopy (TEM) integrated with selected area electron diffraction (SAED). The laser irradiated spot was divided into strong ablation area, gentle ablation area, melting area and irradiation area. By theoretical calculation, the ablation and melting thresholds were determined to be 173.05 mJ cm-2 and 99.19 mJ cm-2 respectively. Meantime, the local fine morphologies of the ablation and melting areas were shown and analyzed. We also studied the irradiation area which was made up by the non-phase-change area and phase-change area. In the phase-change area, crystalline phase was determined to be face-centered cubic structure and crystalline phase characteristics for films with different thicknesses were discussed.

  18. Prevention of shockwave induced functional and morphological alterations: an overview.

    PubMed

    Sarica, Kemal; Yencilek, Faruk

    2008-03-01

    Experimental as well as clinical findings reported in the literature suggest that treatment with shock wave lithotripsy (SWL) causes renal parenchymal damage mainly by generating free radicals through ischaemia/reperfusion injury mechanism. Although SWL-induced renal damage is well tolerated in the majority of healthy cases with no permanent functional and/or morphologic side effects, a subset of patients with certain risk factors requires close attention on this aspect among which the ones with pre-existing renal disorders, urinary tract infection, previous lithotripsy history and solitary kidneys could be mentioned. It is clear that in such patients lowering the number of shock waves (per session) could be beneficial and has been applied by the physicians as the first practical step of diminishing SWL induced parenchymal damage. On the other hand, taking the injurious effects of high energy shock wave (HESW) induced free radical formation on renal parenchyma and subsequent histopathologic alterations into account, physicians searched for some protective agents in an attempt to prevent or at least to limit the extent of the functional as well as the morphologic alterations. Among these agents calcium channel blocking agents (verapamil and nifedipine), antioxidant agents (allopurinol, vitamin E and selenium) and potassium citrate have been used to minimize these adverse effects. Additionally, therapeutic application of these agents on reducing stone recurrence particularly after SWL will gain more importance in the future in order to limit new stone formation in these cases. Lastly, as experimental and clinical studies have demonstrated, combination of anti-oxidants with free radical scavengers may provide superior renal protection against shock wave induced trauma. However, we believe that further investigations are certainly needed to determine the dose-response relationship between the damaging effects of SWL application and the protective role of these agents.

  19. Morphology and Phase Transitions in Styrene-Butadiene-Styrene Triblock Copolymer Grafted with Isobutyl-Substituted Polyhedral Oligomeric Silsesquioxanes

    SciTech Connect

    Drazkowski, Daniel B.; Lee, Andre; Haddad, Timothy S.

    2008-10-03

    Two symmetric triblock polystyrene-butadiene-polystyrene (SBS) copolymers with different initial morphologies were grafted with varying amounts of isobutyl-substituted polyhedral oligomeric silsesquioxane (POSS) molecules. The POSS octamers, R{prime}R{sub 7}Si{sub 8}O{sub 12}, were designed to contain a single silane functional group, R{prime}, which was used to graft onto the dangling 1,2-butadienes in the polybutadiene block and seven identical organic groups, R = isobutyl (iBu). Morphology and phase transitions of these iBu-POSS-modified SBS were investigated using small-angle X-ray scattering and rheological methods. It was observed that when iBu-POSS was grafted to the butadiene segment, the long-range and local order of the morphology were preserved, and the d-spacing showed a small, systematic increase with increasing POSS content. These observations suggest that grafted iBu-POSS were well-distributed within the butadiene domains and did not interact with the styrene domains; effectively, grafting of iBu-POSS to butadiene did not affect the segregation between butadiene and styrene domains. However, addition of iBu-POSS reduces the overall polystyrene volume. Consequently, from a morphology standpoint, this modification effectively shifts the phase diagram to lower styrene content. This was supported with SAXS and transition temperatures measurements made from the different host morphologies.

  20. 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.

  1. [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.

  2. Morphology and Composition of Structured, Phase-Separated Behenic Acid-Perfluorotetradecanoic Acid Monolayer Films.

    PubMed

    Rehman, Jeveria; Araghi, Hessamaddin Younesi; He, Anqiang; Paige, Matthew F

    2016-05-31

    The phase separation of immiscible surfactants in mixed monolayer films provides an approach to physically manipulate important properties of thin films, including surface morphology, microscale composition, and mechanical properties. In this work, we predict, based upon existing miscibility studies and their thermodynamic underpinnings described in the literature, the miscibility and film morphology of mixed monolayers comprised of behenic acid (C21H43COOH) and perfluorotetradecanoic acid (C13F27COOH) in various molar ratios. Predictions are tested using a combination of experimental surface characterization methods for probing miscibility and film morphology at the solid/air and air/water interfaces. Film components were immiscible and phase-separated into chemically well-defined domains under a variety of experimental conditions, with monolayer morphology consistent with initial predictions. The extensibility of these basic predictions to other systems is discussed in the context of using these works for different perfluorinated surfactant molecules. PMID:27163482

  3. 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

  4. Permeability and morphology of low temperature phases in bilayers of single and of mixtures of phosphatidylcholines.

    PubMed

    Singer, M A; Finegold, L

    1985-06-27

    The properties of subtransitions were studied in aqueous dispersions of saturated phosphatidylcholines (PC) by means of permeability measurements, freeze-fracture electron microscopy, and differential scanning calorimetry (DSC). For dispersions of C16PC, a C16PC analog (2,3-dipalmitoyl-cyclopentano-1-phosphocholine with four methylene residues between the nitrogen and the phosphorus atoms) and C17PC, there was good agreement between phase properties (including subtransitions) as observed by DSC and temperature-related permeability. C16PC and C17PC dispersions also displayed a 'crinkled' surface morphology in the subgel state. The phase diagram for mixtures of C14PC and C16PC was consistent with ideal mixing of these two components in the subgel state and also illustrated the relative independence of the subtransition on acyl chain length as compared to the pre- and main transitions. Together, these results indicate that (i) permeability, DSC and freeze-fracture electron microscopy measurements do correlate reasonably well with the existence of a subgel state, (ii) mixtures of lipids with similar acyl chain lengths can be used to investigate subtransitions, (iii) the development of a subtransition appears to be mainly a function of the non-acyl chain moiety of the phospholipid. PMID:4005246

  5. A HST/WFC3-IR MORPHOLOGICAL SURVEY OF GALAXIES AT z = 1.5-3.6. II. THE RELATION BETWEEN MORPHOLOGY AND GAS-PHASE KINEMATICS

    SciTech Connect

    Law, David R.; Steidel, Charles C.; Shapley, Alice E.; Nagy, Sarah R.; Reddy, Naveen A.; Erb, Dawn K. E-mail: ccs@astro.caltech.edu E-mail: snagy@ucla.edu

    2012-11-01

    We analyze rest-frame optical morphologies and gas-phase kinematics as traced by rest-frame far-UV and optical spectra for a sample of 204 star-forming galaxies in the redshift range z {approx} 2-3 drawn from the Keck Baryonic Structure Survey. We find that spectroscopic properties and gas-phase kinematics are closely linked to morphology: compact galaxies with semimajor axis radii r {approx}< 2 kpc are substantially more likely than their larger counterparts to exhibit Ly{alpha} in emission. Although Ly{alpha} emission strength varies widely within galaxies of a given morphological type, all but one of 19 galaxies with Ly{alpha} equivalent width W {sub Ly{alpha}} > 20 A have compact and/or multiple-component morphologies with r {<=} 2.5 kpc. The velocity structure of absorption lines in the galactic continuum spectra also varies as a function of morphology. Galaxies of all morphological types drive similarly strong outflows (as traced by the blue wing of interstellar absorption line features), but the outflows of larger galaxies are less highly ionized and exhibit larger optical depth at the systemic redshift that may correspond to a decreasing efficiency of feedback in evacuating gas from the galaxy. This v {approx} 0 km s{sup -1} gas is responsible both for shifting the mean absorption line redshift and attenuating W {sub Ly{alpha}} (via a longer resonant scattering path) in galaxies with larger rest-optical half-light radii. In contrast to galaxies at lower redshifts, there is no evidence for a correlation between outflow velocity and inclination, suggesting that outflows from these puffy and irregular systems may be poorly collimated. Our observations are broadly consistent with theoretical models of inside-out growth of galaxies in the young universe, in which typical z {approx} 2-3 star-forming galaxies are predominantly unstable, dispersion-dominated, systems fueled by rapid gas accretion that later form extended rotationally supported disks when stabilized

  6. 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.

  7. Morphological characterization of β phase in poly-(vinylidenefluoride) film prepared by spin cast method

    SciTech Connect

    Mehtani, Hitesh Kumar Kumar, Rishi Raina, K. K.

    2014-04-24

    Poly-(Vinylidene fluoride) PVDF film was prepared by spin casting method to control the pore size of the matrix. The morphological spherulitic structure was confirmed Scanning Electron Microscopy (SEM) after gold sputtering and the presence of β phase was ensured in spin cast PVDF film by the FTIR spectroscopy. The β phase is very important in the application because it improve the properties like piezoelectricity by modifying PVDF crystallinity.

  8. 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.

  9. 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.

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

    PubMed Central

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

    2015-01-01

    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. PMID:26603478

  11. Calmodulin inhibition regulates morphological and functional changes related to the actin cytoskeleton in pure microglial cells.

    PubMed

    Szabo, Melinda; Dulka, Karolina; Gulya, Karoly

    2016-01-01

    The roles of calmodulin (CaM), a multifunctional intracellular calcium receptor protein, as concerns selected morphological and functional characteristics of pure microglial cells derived from mixed primary cultures from embryonal forebrains of rats, were investigated through use of the CaM antagonists calmidazolium (CALMID) and trifluoperazine (TFP). The intracellular localization of the CaM protein relative to phalloidin, a bicyclic heptapeptide that binds only to filamentous actin, and the ionized calcium-binding adaptor molecule 1 (Iba1), a microglia-specific actin-binding protein, was determined by immunocytochemistry, with quantitative analysis by immunoblotting. In unchallenged and untreated (control) microglia, high concentrations of CaM protein were found mainly perinuclearly in ameboid microglia, while the cell cortex had a smaller CaM content that diminished progressively deeper into the branches in the ramified microglia. The amounts and intracellular distributions of both Iba1 and CaM proteins were altered after lipopolysaccharide (LPS) challenge in activated microglia. CALMID and TFP exerted different, sometimes opposing, effects on many morphological, cytoskeletal and functional characteristics of the microglial cells. They affected the CaM and Iba1 protein expressions and their intracellular localizations differently, inhibited cell proliferation, viability and fluid-phase phagocytosis to different degrees both in unchallenged and in LPS-treated (immunologically challenged) cells, and differentially affected the reorganization of the actin cytoskeleton in the microglial cell cortex, influencing lamellipodia, filopodia and podosome formation. In summary, these CaM antagonists altered different aspects of filamentous actin-based cell morphology and related functions with variable efficacy, which could be important in deciphering the roles of CaM in regulating microglial functions in health and disease.

  12. High internal phase emulsion with double emulsion morphology and their templated porous polymer systems.

    PubMed

    Lei, Lei; Zhang, Qi; Shi, Shuxian; Zhu, Shiping

    2016-12-01

    This paper reports synthesis of the first high internal phase emulsion (HIPE) system with double emulsion (DE) morphology (HIPE-DE). HIPE is a highly concentrated but highly stable emulsion system, which has a dispersed/internal phase fraction over 74vol%. DE represents an emulsion system that hierarchically encapsulates two immiscible phases. The combination of HIPE and DE provides an efficient method for fabrication of complex structures. In this work, HIPE-DE having a water-in-oil-in-water (W/O/W) morphology has been prepared for the first time via a simple one-step emulsification method with poly(2-(diethylamino)ethyl methacrylate) (PDEA) microgel particles as Pickering stabilizer. An oil phase fraction up to 90vol% was achieved by optimizing the microgel concentration in aqueous phase. The mechanism of the DE formation has been elucidated. It was found that while PDEA microgels stabilized the oil droplets in water, small amount protonated DEA monomers acted as surfactant and formed water-containing micelles inside the oil droplets. It was demonstrated that the W/O/W HIPE-DE could be precisely converted into porous polymer structures. With styrene as the oil phase in W/O/W HIPE-DE, porous polystyrene particles were obtained upon polymerization. With dissolved acrylamide as the aqueous phase and toluene as the continuous phase, porous polyacrylamide matrixes were prepared. Elevating temperature required for polymerization did not change the W/O/W HIPE-DE morphologies. This simple approach provides a versatile platform for synthesis of a variety of porous polymer systems. PMID:27560496

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

    PubMed

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

    2009-06-01

    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.

  14. Phenotypic engineering unveils the function of genital morphology.

    PubMed

    Hotzy, Cosima; Polak, Michal; Rönn, Johanna L; Arnqvist, Göran

    2012-12-01

    The rapidly evolving and often extraordinarily complex appearance of male genital morphology of internally fertilizing animals has been recognized for centuries. Postcopulatory sexual selection is regarded as the likely evolutionary engine of this diversity, but direct support for this hypothesis is limited. We used two complementary approaches, evolution through artificial selection and microscale laser surgery, to experimentally manipulate genital morphology in an insect model system. We then assessed the competitive fertilization success of these phenotypically manipulated males and studied the fate of their ejaculate in females using high-resolution radioisotopic labeling of ejaculates. Males with longer genital spines were more successful in gaining fertilizations, providing experimental evidence that male genital morphology influences success in postcopulatory reproductive competition. Furthermore, a larger proportion of the ejaculate moved from the reproductive tract into the female body following mating with males with longer spines, suggesting that genital spines increase the rate at which seminal fluid passes into the female hemolymph. Our results show that genital morphology affects male competitive fertilization success and imply that sexual selection on genital morphology may be mediated in part through seminal fluid. PMID:23103188

  15. Morphology and motion: hindlimb proportions and swing phase kinematics in terrestrially locomoting charadriiform birds.

    PubMed

    Kilbourne, Brandon M; Andrada, Emanuel; Fischer, Martin S; Nyakatura, John A

    2016-05-01

    Differing limb proportions in terms of length and mass, as well as differences in mass being concentrated proximally or distally, influence the limb's moment of inertia (MOI), which represents its resistance to being swung. Limb morphology - including limb segment proportions - thus probably has direct relevance for the metabolic cost of swinging the limb during locomotion. However, it remains largely unexplored how differences in limb proportions influence limb kinematics during swing phase. To test whether differences in limb proportions are associated with differences in swing phase kinematics, we collected hindlimb kinematic data from three species of charadriiform birds differing widely in their hindlimb proportions: lapwings, oystercatchers and avocets. Using these three species, we tested for differences in maximum joint flexion, maximum joint extension and range of motion (RoM), in addition to differences in maximum segment angular velocity and excursion. We found that the taxa with greater limb MOI - oystercatchers and avocets - flex their limbs more than lapwings. However, we found no consistent differences in joint extension and RoM among species. Likewise, we found no consistent differences in limb segment angular velocity and excursion, indicating that differences in limb inertia in these three avian species do not necessarily underlie the rate or extent of limb segment movements. The observed increased limb flexion among these taxa with distally heavy limbs resulted in reduced MOI of the limb when compared with a neutral pose. A trade-off between exerting force to actively flex the limb and potential savings by a reduction of MOI is skewed towards reducing the limb's MOI as a result of MOI being in part a function of the radius of gyration squared. Increased limb flexion is a likely means to lower the cost of swinging the limbs. PMID:26944500

  16. Esthetic and functional reproduction of occlusal morphology with composite resins.

    PubMed

    Goracci, G; Mori, G

    1999-07-01

    The increasing use of composite resin restorations in posterior sectors produces some difficulties in the exact reproduction of occlusal morphology. In this article we present a new operative method that allows a quick and precise reproduction of occlusal morphology with minimal carious destruction of the occlusal enamel of posterior dental elements in the case of initial carious lesions. This method is indicated for class I and II carious lesions and is based on a preoperative record of the occlusal morphology made with a transparent silicone mold. This mold is placed on the tooth after the application of the last layer of composite resin, which is then polymerized through the silicone. Illustrated as a clinical case, the method is particularly rapid, easy to perform, and contributes to the improved quality and subsequent success of composite restorations in posterior sectors.

  17. Phase transfer function of digital imaging systems

    NASA Astrophysics Data System (ADS)

    Bhakta, Vikrant R.

    For the past several decades, optical engineering has relied heavily on Fourier analysis of linear systems as a valuable aid in realizing numerous imaging applications. Today, spatial frequency analysis via the optical transfer function (OTF) remains an integral tool for the design, characterization and testing of incoherent imaging systems. The magnitude of the complex OTF is known as the modulation transfer function (MTF) and its phase is given by the phase transfer function (PTF). The MTF represents the contrast reduction at each spatial frequency; whereas, the PTF represents the spatial shift of these frequencies. While the MTF has been used extensively to characterize imaging systems, the PTF has long been ignored because it was thought to have an insignificant presence and to be difficult to understand and measure. Through theoretical analysis and experimental demonstrations, this work addresses all of these issues and shows that the PTF is a valuable tool for modern-day digital imaging systems. The effects of optical aberrations on the PTF of an imaging system in the absence of aliasing have been analyzed in detail. However, for the digital imaging systems, the effect of aliasing on the overall system behavior becomes an important consideration. To this end, the effects of aliasing on the PTF of the sampled imaging system are described and its key properties are derived. The role of PTF as an essential metric in today's imaging systems necessitates practical PTF measurement techniques. Two, easy-to-implement, image-based methods for PTF measurement are described and experimentally validated. These measurement methods and the insights gained from the theoretical analysis are leveraged for several applications spanning diverse fields such as optical system characterization, computational imaging, and image processing.

  18. Changes to the Disordered Phase and Apatite Crystallite Morphology during Mineralization by an Acidic Mineral Binding Peptide from Osteonectin.

    PubMed

    Iline-Vul, Taly; Matlahov, Irina; Grinblat, Judith; Keinan-Adamsky, Keren; Goobes, Gil

    2015-09-14

    Noncollagenous proteins regulate the formation of the mineral constituent in hard tissue. The mineral formed contains apatite crystals coated by a functional disordered calcium phosphate phase. Although the crystalline phase of bone mineral was extensively investigated, little is known about the disordered layer's composition and structure, and less is known regarding the function of noncollagenous proteins in the context of this layer. In the current study, apatite was prepared with an acidic peptide (ON29) derived from the bone/dentin protein osteonectin. The mineral formed comprises needle-shaped hydroxyapatite crystals like in dentin and a stable disordered phase coating the apatitic crystals as shown using X-ray diffraction, transmission electron microscopy, and solid-state NMR techniques. The peptide, embedded between the mineral particles, reduces the overall phosphate content in the mineral formed as inferred from inductively coupled plasma and elemental analysis results. Magnetization transfers between disordered phase species and apatitic phase species are observed for the first time using 2D (1)H-(31)P heteronuclear correlation NMR measurements. The dynamics of phosphate magnetization transfers reveal that ON29 decreases significantly the amount of water molecules in the disordered phase and increases slightly their content at the ordered-disordered interface. The peptide decreases hydroxyl to disordered phosphate transfers within the surface layer but does not influence transfer within the bulk crystalline mineral. Overall, these results indicate that control of crystallite morphology and properties of the inorganic component in hard tissue by biomolecules is more involved than just direct interaction between protein functional groups and mineral crystal faces. Subtler mechanisms such as modulation of the disordered phase composition and structural changes at the ordered-disordered interface may be involved. PMID:26207448

  19. Supertoughened renewable PLA reactive multiphase blends system: phase morphology and performance.

    PubMed

    Zhang, Kunyu; Nagarajan, Vidhya; Misra, Manjusri; Mohanty, Amar K

    2014-08-13

    Multiphase blends of poly(lactic acid) (PLA), ethylene-methyl acrylate-glycidyl methacrylate (EMA-GMA) terpolymer, and a series of renewable poly(ether-b-amide) elastomeric copolymer (PEBA) were fabricated through reactive melt blending in an effort to improve the toughness of the PLA. Supertoughened PLA blend showing impact strength of ∼500 J/m with partial break impact behavior was achieved at an optimized blending ratio of 70 wt % PLA, 20 wt % EMA-GMA, and 10 wt % PEBA. Miscibility and thermal behavior of the binary blends PLA/PEBA and PLA/EMA-GMA, and the multiphase blends were also investigated through differential scanning calorimetric (DSC) and dynamic mechanical analysis (DMA). Phase morphology and fracture surface morphology of the blends were studied through scanning electron microscopy (SEM) and atomic force microscopy (AFM) to understand the strong corelation between the morphology and its significant effect on imparting tremendous improvement in toughness. A unique "multiple stacked structure" with partial encapsulation of EMA-GMA and PEBA minor phases was observed for the PLA/EMA-GMA/PEBA (70/20/10) revealing the importance of particular blend composition in enhancing the toughness. Toughening mechanism behind the supertoughened PLA blends have been established by studying the impact fractured surface morphology at different zones of fracture. Synergistic effect of good interfacial adhesion and interfacial cavitations followed by massive shear yielding of the matrix was believed to contribute to the enormous toughening effect observed in these multiphase blends.

  20. Morphology control of phase separated ferroelectric-semiconductor polymer blends for organic memory

    NASA Astrophysics Data System (ADS)

    Su, Gregory; Jacobs, Andrew; Kramer, Edward; Chabinyc, Michael

    2014-03-01

    The ability to store memory is essential for many electronic applications. All-organic memory devices based on a blend of a ferroelectric polymer and a semiconducting polymer have recently shown great promise for low-cost memory technology based on ferroelectricity. The thin film morphology of the phase separated ferroelectric-semiconductor polymer blend is critically important for working devices and improved operation. However, precise morphology control has so far been relatively unattainable. Here, we report on a new semiconducting polythiophene with a modified side chain structure (PEPT) that demonstrates a greatly improved phase separated morphology with the well-studied ferroelectric polymer poly[(vinylidenefluoride-co-trifluoroethylene] (PVDF-TrFE). Thin film surface and bulk characterization via microscopy, soft X-ray spectroscopy, and X-ray scattering experiments reveal that PEPT:PVDF-TrFE blends exhibit domain sizes that are easily tunable through simple parameters such as blend ratio. These results demonstrate progress toward achieving organic ferroelectric-semiconductor memory with optimized morphology and the techniques required for thorough thin film surface and bulk characterization.

  1. Morphological adaptation and inhibition of cell division during stationary phase in Caulobacter crescentus.

    PubMed

    Wortinger, M A; Quardokus, E M; Brun, Y V

    1998-08-01

    During exponential growth, each cell cycle of the alpha-purple bacterium Caulobacter crescentus gives rise to two different cell types: a motile swarmer cell and a sessile stalked cell. When cultures of C. crescentus are grown for extended periods in complex (PYE) medium, cells undergo dramatic morphological changes and display increased resistance to stress. After cultures enter stationary phase, most cells are arrested at the predivisional stage. For the first 6-8 days after inoculation, the colony-forming units (cfu) steadily decrease from 10(9) cfu ml(-1) to a minimum of 3x10(7) cfu ml(-1) after which cells gradually adopt an elongated helical morphology. For days 9-12, the cfu of the culture increase and stabilize around 2 x 10(8) cfu ml(-1). The viable cells have an elongated helical morphology with no constrictions and an average length of 20 microm, which is 15-20 times longer than exponentially growing cells. The level of the cell division initiation protein FtsZ decreases during the first week in stationary phase and remains at a low constant level consistent with the lack of cell division. When resuspended in fresh medium, the elongated cells return to normal size and morphology within 12 h. Cells that have returned from stationary phase proceed through the same developmental changes when they are again grown for an extended period and have not acquired a heritable growth advantage in stationary phase (GASP) compared with overnight cultures. We conclude that the changes observed in prolonged cultures are the result of entry into a new developmental pathway and are not due to mutation. PMID:9767565

  2. 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.

  3. Self-organization in phase separation of a lyotropic liquid crystal into cellular, network and droplet morphologies.

    PubMed

    Iwashita, Yasutaka; Tanaka, Hajime

    2006-02-01

    Phase separation is one of the most fundamental physical phenomena that controls the morphology of heterogeneous structures. Phase separation of a binary mixture of simple liquids produces only two morphologies: a bicontinuous or a droplet structure in the case of a symmetric or an asymmetric composition, respectively. For complex fluids, there is a possibility to produce other interesting morphologies. We found that a network structure of the minority phase can also be induced transiently on phase separation if the dynamics of the minority phase are much slower than those of the majority phase. Here we induce a cellular structure of the minority phase intentionally with the help of its smectic ordering, using phase separation of a lyotropic liquid crystal into the isotropic and smectic phase. We can control the three morphologies, cellular, network and droplet structures, solely by changing the heating rate. We demonstrate that the kinetic interplay between phase separation and smectic ordering is a key to the morphological selection. This may provide a new route to the formation of network and cellular morphologies in soft materials.

  4. Mammal hip morphology and function: coxa recta and coxa rotunda.

    PubMed

    Bouma, Heinse W; De Boer, Stefan F; De Vos, John; Van Kampen, Paulien M; Hogervorst, Tom

    2013-02-01

    Using 15 parameters, we provide a systematic description of mammal proximal femoral morphology. We established two types of proximal femoral morphology, termed coxa recta and coxa rotunda, characterized by low versus high concavity of the head-neck junction. Concavity is a measure of the sphericity of the femoral head as it meets the femoral neck that can be quantified by angular measurements. We asked whether the parameter of concavity corresponds with the classification of mammal proximal femoral morphology based on coalesced versus separate ossification patterns and locomotor patterns. Statistical analysis demonstrated a distinction between coxa recta and coxa rotunda with significant differences between the two groups in all but 3 of the 15 parameters examined. We found the most discriminating measurement between mammal hips to be the concavity of the posterior head-neck junction (beta angle). Coxa recta (small concavity) and coxa rotunda (large concavity) relate to the ossification pattern seen in proximal femoral development, and species-specific patterns of locomotion. We interpret the two hip types to reflect optimization for strength (recta) versus mobility (rotunda). Conceptually, both hip types can be recognized in humans, where coxa recta can be related to the development of osteoarthritis.

  5. Two Different Types of Single Crystal Morphologies of the γ-Phase and Their Conversion in Isotactic Polypropylene

    NASA Astrophysics Data System (ADS)

    Cao, Yan; van Horn, Ryan; Tsai, Chi-Chun; Graham, Matthew; Jeong, Kwuang-Un; de Rosa, Claudio; Lotz, Bernard; Cheng, Stephen Z. D.

    2009-03-01

    In the past, the crystallographic relationship between the γ-phase and the α-phase in isotactic polypropylene was extensively studied via oligomers of iPP. We attempt to investigate how the crystal morphological changes take place in the γ-phase using high molecular weight iPP-co-polyethylene samples. Due to the specific epitaxial growth of the γ-phase on the elongated α-phase single crystals, two different morphologies were identified via transmission electron and atomic force microscopies. The first γ-phase crystal morphology is needle-like. Selective area electron diffraction results showed that their [1 10] or [110] zone axis was parallel to the thin film normal. The growth of this type of epitaxial γ-phase crystal was due to the stem direction in the initial α-phase single crystal being parallel to the thin film normal. The second γ-phase crystal morphology was flat lamellae. This requires that the initial α-phase single crystal had to have a stem orientation tilted away from the thin film normal. Therefore, the sufficient and necessary condition for the γ-phase morphological conversion from the needle-like crystal to the flat crystal is the change of the stem orientation direction of the initial α-phase single crystals.

  6. 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

  7. [The Different Phase, Morphology Controllable Synthesis and Luminescent Properties Investigation of NaYF⁴: Yb, Er].

    PubMed

    Han, Yu-ting; Xu, Jing; Qiao, Shu-liang; Yang, Bo; Li, Li; Liu, Cai-hong; Yao, Shuang; Yan, Jing-hui; Zou, Ming-qiang

    2015-12-01

    Using sodium fluoride and rare earth nitrate as raw materials and sodium citrate as surfactant, micron grade NaYF4 upconversion luminescent materials were prepared by hydrothermal method. By X-ray diffraction(XRD), scanning electron microscope(SEM) and fluorescence spectrometer, the crystal phase, morphology and luminescent characteristics of the prepared samples were investigated. The results showed that the phase of the samples could generate a transition from cubic phase to hexagonal phase by adjusting the proportion (5, 6, 7, 8, 9, 11) of NaF/RE , and the X ray diffraction peaks for the cubic and hexagonal phase of samples exactly matched with those of the standard card of PDF# 77-2042 and PDF# 16-0334, respectively. The SEM photographs showed that the crystallinity of samples was high and the dispersibility was favourable, the morphology were translated from microrods to hexagonal microplates. The samples upconversion luminescent spectra showed the intensity enhancement of red and green light emission peaks with increasement of the ratio of NaF/RE3+. The green emission peaks of samples at 520 and 539 nm corresponded to the ²H¹¹/²-⁴-->I₁₅/₂ and ⁴S₃/₂-->⁴I₁₅/₂ level transition of Er³⁺ ion, and the red light emission peaks of samples at 653 nm corresponded to the ⁴F₉/₂-->⁴I₁₅/₂ levelt ransition of Er+ ion. The chromaticity coordinate diagram exhibited that the change of the luminescent color of samples could be achieved by adjusting the ratio of NaF/RE³⁺. With the increasing of NaF/RE³⁺ ratio, for the whole light-emitting colors of samples, the shift from yellow region to near red region could be realized. It can be concluded that through the relatively simple experimental procedure and lower cost materials, the change of phase and morphology, the moving of light-emitting color for sample NaYF4:Yb³⁺, Er³⁺ could be well controlled only by changing the single component (NaF) molar ratio in the raw materials

  8. Analytical approximations to seawater optical phase functions of scattering

    NASA Astrophysics Data System (ADS)

    Haltrin, Vladimir I.

    2004-11-01

    This paper proposes a number of analytical approximations to the classic and recently measured seawater light scattering phase functions. The three types of analytical phase functions are derived: individual representations for 15 Petzold, 41 Mankovsky, and 91 Gulf of Mexico phase functions; collective fits to Petzold phase functions; and analytical representations that take into account dependencies between inherent optical properties of seawater. The proposed phase functions may be used for problems of radiative transfer, remote sensing, visibility and image propagation in natural waters of various turbidity.

  9. Characterization of pore scale NAPL morphology in homogeneous sands as a function of grain size and NAPL dissolution.

    PubMed

    Cho, Jaehyun; Annable, Michael D

    2005-11-01

    In this study, we investigate pore scale morphology of nonaqueous phase liquids (NAPLs) trapped in different pore sizes using tracer techniques. Specific interfacial area and saturation of NAPL trapped in homogeneous sands were measured using the interfacial and partitioning tracer techniques. The observed NAPL-water interfacial areas increased in a log-linear fashion with decreasing sand grain size, but showed no clear trend with residual NAPL saturation formed in the various grain sizes. The measured values were used to calculate the NAPL morphology index, which characterizes the spatial NAPL distribution within the pore space. The NAPL morphology indices, increased exponentially with decreasing grain size, indicating that the NAPL becomes smaller, but more blobs. For a fixed grain size, the specific interfacial area and saturation of the NAPL were measured following changes caused by dissolution using alcohol. The observed interfacial areas showed a decrease linearly as a function of the NAPL saturation.

  10. 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.

  11. Dispersion morphology diagrams for three-phase, [open quotes]microemulsion[close quotes] emulsions. 2. [open quotes]Disappearance[close quotes] of morphology-transition lines

    SciTech Connect

    Johnson, G.K. ); Dadyburjor, D.B. ); Smith, D.H. Univ. of Oklahoma, Norman, OK )

    1994-11-17

    The limits over which the oil-rich top phase (T), middle-phase microemulsion (M), or water-rich bottom phase (B) is the continuous phase in steady-state, three-phase macroemulsions have been determined by means of electrical conductivity measurements for the amphiphile/oil/[open quotes]water[close quotes] system C[sub 6]H[sub 13](OC[sub 2]H[sub 4])[sub 2]OH/n-tetradecane/aqueous 10 mM NaCl. Measurements were made at three different temperatures and apparent wettability conditions: (a) 45[degrees]C, wetting middle phase; (b) 25[degrees]C, no wetting phase; and (c) 12[degrees]C, wetting bottom phase. The results at 25[degrees]C were in accord with expectations from previous predictions and experiments; but for both two-phase and three-phase emulsions no abrupt, [open quotes]first-order[close quotes] transitions between M- and T-continuous emulsions at 45[degrees]C or between M- and B-continuous emulsions at 12[degrees]C were found. Instead, these changes of continuous phase appeared to occur smoothly and continuously between their respective single-phase and two-phase limits. It is not yet clear if the [open quotes]disappearance[close quotes] of first-order morphology transitions correlates with phase wettability transitions; the phenomenon suggests the possibility of bicontinuous two-phase and three-phase macroemulsions. 31 refs., 11 figs.

  12. Functional morphology of the genital organs in the wild paca (Cuniculus paca) female.

    PubMed

    Mayor, P; Guimarães, D A; López, C

    2013-08-01

    Functional morphology of the genital organs is a key knowledge component for enhanced understanding of physiological patterns and for the determination of the reproductive performance in wild species. This study examines the morphology of genital organs of 133 paca females in the wild. Estimated conceptions and parturitions were mostly (83.7% and 75.5%, respectively) localized in the wet season. The pregnancy rate between 57.1% and 61.4% suggests an estimated yearly production of 1.37-1.48 parturitions and a long estimated farrowing interval of 247-266 days. Although large antral follicles were observed in all females, pregnant females had a greater number of antral follicles than females in the luteal phase. The average litter size was 1.03 foetuses per pregnant female, and mean ovulation rate was 1.33 follicles, resulting in a rate of reproductive wastage of 28.7%. The constituent active luteal tissues of the ovary were oestrous cyclic, pregnancy and accessory CL. The 50% of pregnant females in the late pregnancy stage lacked pregnancy CL, suggesting that placenta may become the mean source of progesterone during late stages of pregnancy. Results of the present study suggest that the observation of the vaginal closure membrane should not be an accurate tool for diagnosing oestrus in the paca female.

  13. The Tricontinuous 3ths(5) Phase: A New Morphology in Copolymer Melts

    NASA Astrophysics Data System (ADS)

    Fischer, Michael; de Campo, Liliana; Kirkensgaard, Jacob; Hyde, Stephen; Schroeder-Turk, Gerd

    2015-03-01

    Self-assembly remains one of the most efficient routes to the formation of ordered nanostructures, including the double gyroid network phase in diblock copolymers based on two intergrown network domains. This talk demonstrates the use of self-consistent field theory to show that a tricontinuous structure with monoclinic symmetry, called 3ths(5), based on the intergrowth of three distorted ths nets, is an equilibrium phase of triblock star-copolymer melts when an extended molecular core is introduced. The introduction of the core enhances the role of chain stretching by enforcing larger structural length scales, thus destabilizing the hexagonal columnar phase in favor of morphologies with less packing frustration. This study further demonstrates that the introduction of molecular cores is a general concept for tuning the relative importance of entropic and enthalpic free energy contributions, hence providing a tool to stabilize an extended repertoire of self-assembled nanostructured materials.

  14. 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.

  15. Cell morphology classification in phase contrast microscopy image reducing halo artifact

    NASA Astrophysics Data System (ADS)

    Kang, Mi-Sun; Song, Soo-Min; Lee, Hana; Kim, Myoung-Hee

    2012-03-01

    Since the morphology of tumor cells is a good indicator of their invasiveness, we used time-lapse phase-contrast microscopy to examine the morphology of tumor cells. This technique enables long-term observation of the activity of live cells without photobleaching and phototoxicity which is common in other fluorescence-labeled microscopy. However, it does have certain drawbacks in terms of imaging. Therefore, we first corrected for non-uniform illumination artifacts and then we use intensity distribution information to detect cell boundary. In phase contrast microscopy image, cell is normally appeared as dark region surrounded by bright halo ring. Due to halo artifact is minimal around the cell body and has non-symmetric diffusion pattern, we calculate cross sectional plane which intersects center of each cell and orthogonal to first principal axis. Then, we extract dark cell region by analyzing intensity profile curve considering local bright peak as halo area. Finally, we examined cell morphology to classify tumor cells as malignant and benign.

  16. Observation of dendritic cell morphology under light, phase-contrast or confocal laser scanning microscopy.

    PubMed

    Tan, Yuen-Fen; Leong, Chooi-Fun; Cheong, Soon-Keng

    2010-12-01

    Dendritic cells (DCs) are professional antigen presenting cells of the immune system. They can be generated in vitro from peripheral blood monocytes supplemented with GM-CSF, IL-4 and TNF alpha. During induction, DCs will increase in size and acquire multiple cytoplasmic projections when compared to their precursor cells such as monocytes or haematopoietic stem cells which are usually round or spherical. Morphology of DCs can be visualized by conventional light microscopy after staining or phase-contrast inverted microscopy or confocal laser scanning microscopy. In this report, we described the morphological appearances of DCs captured using the above-mentioned techniques. We found that confocal laser scanning microscopy yielded DCs images with greater details but the operating cost for such a technique is high. On the other hand, the images obtained through light microscopy after appropriate staining or phase contrast microscopy were acceptable for identification purpose. Besides, these equipments are readily available in most laboratories and the cost of operation is affordable. Nevertheless, morphological identification is just one of the methods to characterise DCs. Other methods such as phenotypic expression markers and mixed leukocyte reactions are additional tools used in the characterisation of DCs. PMID:21329180

  17. Polymorphism of Sporothrix schenckii surface polysaccharides as a function of morphological differentiation.

    PubMed

    Mendonça, L; Gorin, P A; Lloyd, K O; Travassos, L R

    1976-06-01

    The alkali-extractable polysaccharides from different morphological types of two Sporothrix schenckii strains (1099.12 and 1099.18) were investigated. Dissociation of morphological phase transition and temperature effects was possible in a synthetic medium which produced cultures with 100% yeast forms either at 25 or at 37 degrees C. Only rhamnomannans with single-unit alpha-L-rhamnopyranosyl side chains were formed by the yeast forms irrespective of the incubation temperature. The higher temperature inhibited formation of 4-O- and 2,4-di-O-substituted alpha-D-mannopyranose units in the rhamnomannan. An apparently unsporulated mycelium culture of one S. schenckii strain (1099.12) synthesized a galactomannan whose structure was partially determined by methylation analysis and by proton and 13C nuclear magnetic resonance spectroscopy. In another strain (1099.18), a mannan was excreted in the medium of an apparently conidia-less mycelial form at 25 degrees C with short incubation. Its structure was also partially determined. An apparent mixture of this mannan and a rhamnomannan rich in alpha-L-rhamnopyranosyl-(1 leads to 2)-alpha-L-rhamnopyranose side chains formed in these cultures on prolonged incubation. The proportion of the excreted rhamnomannan increased as the mycelium sporulated and conidia were more numerous. Mannans or galactomannans may be transient polysaccharides in the young mycelium of S. schenckii. As the culture develops, rhamnomannans are formed in amounts usually masking the presence of other mannose-containing polysaccharides. It is suggested that in S. schenckii different polysaccharides are formed with side chains containing different proportions of rhamnose, mannose, or galactose, as a function of morphological differentiation.

  18. Phase Transitions and Honeycomb Morphology in an Incompatible Blend of Enantiomeric Polylactide Block Copolymers

    NASA Astrophysics Data System (ADS)

    Sun, Lu; Ginorio, Jorge; Zhu, Lei; Rong, Lixia; Sics, Igor; Hsiao, Benjamin

    2007-03-01

    Enantiomeric PLAs, poly(L-lactide) (PLLA) and poly(D-lactide) (PDLA), are known to form stereocomplexes. In this work, by using controlled ring-opening polymerization of L- and D-lactides from monohydroxyl-terminated hydrophilic poly(ethylene oxide) (PEO) and hydrophobic poly(ethylene-co-1-butene) (PEB) oligomers, respectively, well-defined PEO-b-PLLA (2k-5.4k) and PEB-b-PDLA (4.2-5.4k) block copolymers were synthesized. Quantitative stereocomplex formation was achieved by casting an equimolar mixture of incompatible PEO-b-PLLA and PEB-b-PDLA from chloroform at room temperature. Depending on different thermal histories, either lamellar or inverted cylindrical morphology was observed in the molten state. Intriguingly, novel honeycomb morphology with the minor PEB component forming the matrix was observed in the inverted cylindrical phase.

  19. Functional morphology of gill ventilation of the goosefish, Lophius americanus (Lophiiformes: Lophiidae).

    PubMed

    Farina, Stacy C; Bemis, William E

    2016-06-01

    The goosefish, Lophius americanus, is a dorso-ventrally compressed marine fish that spends most of its life sitting on the substrate waiting to ambush prey. Species in the genus Lophius have some of the slowest ventilatory cycles recorded in fishes, with a typical cycle lasting more than 90s. They have a large gill chamber, supported by long branchiostegal rays and ending in a siphon-like gill opening positioned underneath and behind the base of the pectoral fin. Our goals were to characterize the kinematics of gill ventilation in L. americanus relative to those of more typical ray-finned fishes, address previous assertions about ventilation in this genus, and describe the anatomy of the gill opening. We found that phase 1 of ventilation (during which both the buccal and gill chamber are expanding) is greatly increased in duration relative to that of typical ray-finned fishes (ranging from 62 to 127s), and during this phase, the branchiostegal rays are slowly expanding. This slow expansion is almost visually imperceptible, especially from a dorsal view. Despite this unusually long phase 1, the pattern of skeletal movements follows that of a typical actinopterygian, refuting previous assertions that Lophius does not use its jaws, suspensorium, and operculum during ventilation. When individuals were disturbed from the sediment, they tended to breathe more rapidly by decreasing the duration of phase 1 (to 18-30s). Dissections of the gill opening revealed a previously undocumented dorsal extension of the adductor hyohyoideus muscle, which passes from between the branchiostegal rays, through the ventro-medial wall of the gill opening, and to the dorsal midline of the body. This morphology of the adductor hyohyoideus shares similarities with that of many Tetraodontiformes, and we suggest that it may be a synapomorphy for Lophiiformes+Tetraodontiformes. The specialized anatomy and function of the gill chamber of Lophius represents extreme modifications that provide

  20. 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".

  1. 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". PMID:3535058

  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. 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.

  4. Phase Transformations in CuAu: Morphologies and Kinetics from Quantum Mechanics

    NASA Astrophysics Data System (ADS)

    Elder, Ken; Chakraborty, Bulbul; Goldenfeld, Nigel

    1996-03-01

    The existence of a modulated superlattice at intermediate temperatures in CuAu gives rise to a rich and complex set of phase transformations. For example, quenches from high and low temperatures into the modulated region leads respectively to the nucleation of labyrinth and bullseye patterns. In this alloy even the formation of the ordered superlattice from a disordered phase is dramatically different than that which occurs in standard disorder/order transformations. This transformation is strongly influenced by the presence of small metastable droplets that are the size of the modulated wavelength. A theoretical description(Bulbul Chakraborty, Ken Elder and Nigel Goldenfeld, Physica A, in press (1995)) of these kinetics and morphologies will be presented and compared to experiment. This description is based on a time-dependent Ginzburg-Landau equation that was derived from a quantum mechanical Hamiltonian using the embedded atom method(Bulbul Chakraborty and Zhigang Xi, Phys. Rev. Lett 68), 2039 (1992).

  5. Simulated morphological landscape of polymer single crystals by phase field model

    NASA Astrophysics Data System (ADS)

    Wang, Dong; Shi, Tongfei; Chen, Jizhong; An, Lijia; Jia, Yuxi

    2008-11-01

    The novel phase field model with the "polymer characteristic" was established based on a nonconserved spatiotemporal Ginzburg-Landau equation (TDGL model A). Especially, we relate the diffusion equation with the crystal growth faces of polymer single crystals. Namely, the diffusion equations are discretized according to the diffusion coefficient of every lattice site in various crystal growth faces and the shape of lattice is selected based on the real proportion of the unit cell dimensions. Spatiotemporal growth of syndiotactic polypropylene single crystals during isothermal crystallization has been investigated theoretically based on this phase field model. Two dimensional numerical calculations are performed to elucidate the faceted single crystal growth including square, rectangular, lozenge-shaped, and hexagonal single crystals. Our simulated patterns are in good agreement with the experimental morphologies, and the physical origin of polymer single crystal growth is discussed.

  6. 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.

  7. Morphology and phase separation of hydrophobic clusters of soy globular protein polymers.

    PubMed

    Sun, Xiuzhi Susan; Wang, Donghai; Zhang, Lu; Mo, Xiaoqun; Zhu, Li; Bolye, Dan

    2008-04-01

    Protein hydrophobic interaction has been considered the most important factor dominating protein folding, aggregation, gelling, self-assembly, adhesion, and cohesion properties. In this paper, morphology and phase separation of hydrophobic clusters, networks, and aggregates of soy globular protein polymers, induced by using a reducing agent (NaHSO3), are studied using microscopic instruments. The morphology and phase separation of these hydrophobic clusters are sensitive to protein structure and composition, pH, and ionic-strength (I(m)). Most of the clusters are in spherical-shape architecture and mainly consist of hydrophobic polypeptides. Rod-shape clusters were also observed at higher ionic strength, and mainly consist of hydrophilic polypeptides. The ratio of hydrophobic/hydrophilic (HB/HL) polypeptides is important to facilitate the formation of clusters in an environment with a certain pH value and ionic strength. At HB/HL 0.8, uniform spherical clusters were observed and diameters ranged from 30 to 70 nm. At HB/HL <0.8, large spherical clusters were formed with diameters ranging from 100 to 1,000 nm, and at HB/HL >or=1.8, large hydrophobic aggregates formed, and size of aggregates can be up to 2 500 nm. When solid content increased from 3% to 38%, at I(m) or= 0.115 mol x L(-1), HB/HL ratio >or=1.8, the large aggregates became very cohesive and viscoelastic. Clear phase separation was observed during curing between hydrophobic and hydrophilic protein polymers. Phase-separation degree increased as HB/HL ratio increased.

  8. 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.

  9. 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. PMID:12675561

  10. Phase-field modeling of microstructural pattern formation during directional solidification of peritectic alloys without morphological instability.

    PubMed

    Lo, T S; Karma, A; Plapp, M

    2001-03-01

    During the directional solidification of peritectic alloys, two stable solid phases (parent and peritectic) grow competitively into a metastable liquid phase of larger impurity content than either solid phase. When the parent or both solid phases are morphologically unstable, i.e., for a small temperature gradient/growth rate ratio (G/v(p)), one solid phase usually outgrows and covers the other phase, leading to a cellular-dendritic array structure closely analogous to the one formed during monophase solidification of a dilute binary alloy. In contrast, when G/v(p) is large enough for both phases to be morphologically stable, the formation of the microstructure becomes controlled by a subtle interplay between the nucleation and growth of the two solid phases. The structures that have been observed in this regime (in small samples where convection effects are suppressed) include alternate layers (bands) of the parent and peritectic phases perpendicular to the growth direction, which are formed by alternate nucleation and lateral spreading of one phase onto the other as proposed in a recent model [R. Trivedi, Metall. Mater. Trans. A 26, 1 (1995)], as well as partially filled bands (islands), where the peritectic phase does not fully cover the parent phase which grows continuously. We develop a phase-field model of peritectic solidification that incorporates nucleation processes in order to explore the formation of these structures. Simulations of this model shed light on the morphology transition from islands to bands, the dynamics of spreading of the peritectic phase on the parent phase following nucleation, which turns out to be characterized by a remarkably constant acceleration, and the types of growth morphology that one might expect to observe in large samples under purely diffusive growth conditions.

  11. Functional morphology and evolution of aspiration breathing in tetrapods.

    PubMed

    Brainerd, Elizabeth L; Owerkowicz, Tomasz

    2006-11-01

    In the evolution of aspiration breathing, the responsibility for lung ventilation gradually shifted from the hyobranchial to the axial musculoskeletal system, with axial muscles taking over exhalation first, at the base of Tetrapoda, and then inhalation as well at the base of Amniota. This shift from hyobranchial to axial breathing freed the tongue and head to adapt to more diverse feeding styles, but generated a mechanical conflict between costal ventilation and high-speed locomotion. Some "lizards" (non-serpentine squamates) have been shown to circumvent this speed-dependent axial constraint with accessory gular pumping during locomotion, and here we present a new survey of gular pumping behavior in the tuatara and 40 lizard species. We observed gular pumping behavior in 32 of the 40 lizards and in the tuatara, indicating that the ability to inflate the lungs by gular pumping is a shared-derived character for Lepidosauria. Gular pump breathing in lepidosaurs may be homologous with buccal pumping in amphibians, but non-ventilatory buccal oscillation and gular flutter have persisted throughout amniote evolution and gular pumping may have evolved independently by modification of buccal oscillation. In addition to gular pumping in some lizards, three other innovations have evolved repeatedly in the major amniote clades to circumvent the speed-dependent axial constraint: accessory inspiratory muscles (mammals, crocodylians and turtles), changing locomotor posture (mammals and birds) and respiratory-locomotor phase coupling to reduce the mechanical conflict between aspiration breathing and locomotion (mammals and birds).

  12. Chewing efficiency and occlusal functional morphology in modern humans.

    PubMed

    Laird, Myra F; Vogel, Erin R; Pontzer, Herman

    2016-04-01

    The reduction of occlusal dimensions in early Homo is often proposed to be a functional adaptation to diet. With their smaller occlusal surfaces, species of early Homo are suggested to have reduced food-processing abilities, particularly for foods with high material properties (e.g., increased toughness). Here, we employ chewing efficiency as a measure of masticatory performance to test the relationships between masticatory function and food properties. We predicted that humans are more efficient when processing foods of lower toughness and Young's modulus values, and that subjects with larger occlusal surfaces will be less efficient when processing foods with higher toughness and Young's modulus, as the greater area spreads out the overall bite force applied to food particles. Chewing efficiency was measured in 26 adults using high-speed motion capture and surface electromyography. The dentition of each subject was cast and the occlusal surface was quantified using dental topographic analysis. Toughness and displacement-limited index were negatively correlated with chewing efficiency, but Young's modulus was not. Increased occlusal two-dimensional area and surface area were positively correlated with chewing efficiency for all foods. Thus, larger occlusal surface areas were more efficient when processing foods of greater toughness. These results suggest that the reduction in occlusal area in early Homo was associated with a reduction in chewing efficiency, particularly for foods with greater toughness. Further, the larger occlusal surfaces of earlier hominins such as Australopithecus would have likely increased chewing efficiency and increased the probability of fracture when processing tough foods.

  13. Glucose Tightly Controls Morphological and Functional Properties of Astrocytes.

    PubMed

    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

  14. 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

  15. Chewing efficiency and occlusal functional morphology in modern humans.

    PubMed

    Laird, Myra F; Vogel, Erin R; Pontzer, Herman

    2016-04-01

    The reduction of occlusal dimensions in early Homo is often proposed to be a functional adaptation to diet. With their smaller occlusal surfaces, species of early Homo are suggested to have reduced food-processing abilities, particularly for foods with high material properties (e.g., increased toughness). Here, we employ chewing efficiency as a measure of masticatory performance to test the relationships between masticatory function and food properties. We predicted that humans are more efficient when processing foods of lower toughness and Young's modulus values, and that subjects with larger occlusal surfaces will be less efficient when processing foods with higher toughness and Young's modulus, as the greater area spreads out the overall bite force applied to food particles. Chewing efficiency was measured in 26 adults using high-speed motion capture and surface electromyography. The dentition of each subject was cast and the occlusal surface was quantified using dental topographic analysis. Toughness and displacement-limited index were negatively correlated with chewing efficiency, but Young's modulus was not. Increased occlusal two-dimensional area and surface area were positively correlated with chewing efficiency for all foods. Thus, larger occlusal surface areas were more efficient when processing foods of greater toughness. These results suggest that the reduction in occlusal area in early Homo was associated with a reduction in chewing efficiency, particularly for foods with greater toughness. Further, the larger occlusal surfaces of earlier hominins such as Australopithecus would have likely increased chewing efficiency and increased the probability of fracture when processing tough foods. PMID:27086052

  16. Study of photometric phase curve with new brightness model: refining phase function system parameters of asteroid (107) Camilla

    NASA Astrophysics Data System (ADS)

    Wang, Yi-Bo; Wang, Xiao-Bin; Wang, Ao

    2016-09-01

    We characterize the morphology of the photometric phase curve model of an asteroid with a three-parameter magnitude phase function H — G1 — G2 system by considering the effect of brightness variation arising from a triaxial ellipsoid representing the asteroid's shape. Applying this new model and a Markov Chain Monte Carlo method, we refine the photometric phase curve of asteroid (107) Camilla and obtain its absolute magnitude H = 7.026-0.054+0.052 mag, and phase function parameters G1 = 0.489-0.044+0.043 and G2 = 0.259-0.023+0.023. Meanwhile, we also determine (107) Camilla's orientation of pole (74.1°-4.5°+4.3°, 50.2°-5.0°+5.4°) with rotational period of 4.843928-0.00001+0.000001 h, and axial ratios a/b = 1.409-0.020+0.020 and b/c = 1.249-0.060+0.063. Furthermore, according to the values of phase function parameters G1 and G2, we infer that asteroid (107) Camilla is an X-type asteroid.

  17. Study of photometric phase curve with new brightness model: refining phase function system parameters of asteroid (107) Camilla

    NASA Astrophysics Data System (ADS)

    Wang, Yi-Bo; Wang, Xiao-Bin; Wang, Ao

    2016-09-01

    We characterize the morphology of the photometric phase curve model of an asteroid with a three-parameter magnitude phase function H — G1 — G2 system by considering the effect of brightness variation arising from a triaxial ellipsoid representing the asteroid's shape. Applying this new model and a Markov Chain Monte Carlo method, we refine the photometric phase curve of asteroid (107) Camilla and obtain its absolute magnitude H = 7.026‑0.054+0.052 mag, and phase function parameters G1 = 0.489‑0.044+0.043 and G2 = 0.259‑0.023+0.023. Meanwhile, we also determine (107) Camilla's orientation of pole (74.1°‑4.5°+4.3°, 50.2°‑5.0°+5.4°) with rotational period of 4.843928‑0.00001+0.000001 h, and axial ratios a/b = 1.409‑0.020+0.020 and b/c = 1.249‑0.060+0.063. Furthermore, according to the values of phase function parameters G1 and G2, we infer that asteroid (107) Camilla is an X-type asteroid.

  18. 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

  19. The renal cortical interstitium: morphological and functional aspects

    PubMed Central

    Le Hir, Michel

    2008-01-01

    The renal interstitial compartment, situated between basement membranes of epithelia and vessels, contains two contiguous cellular networks. One network is formed by interstitial fibroblasts, the second one by dendritic cells. Both are in intimate contact with each other. Fibroblasts are interconnected by junctions and connected to basement membranes of vessels and tubules by focal adhesions. Fibroblasts constitute the “skeleton” of the kidney. In the renal cortex, fibroblasts produce erythropoietin and are distinguished from other interstitial cells by their prominent F-actin cytoskeleton, abundance of rough endoplasmic reticulum, and by ecto-5′-nucleotidase expression in their plasma membrane. The resident dendritic cells belong to the mononuclear phagocyte system and fulfil a sentinel function. They are characterized by their expression of MHC class II and CD11c. The central situation of fibroblasts suggests that signals from tubules, vessels, and inflammatory cells converge in fibroblasts and elicit an integrated response. Following tubular damage and inflammatory signals fibroblasts proliferate, change to the myofibroblast phenotype and increase their collagen production, potentially resulting in renal fibrosis. The acquisition of a profibrotic phenotype by fibroblasts in renal diseases is generally considered a main causal event in the progression of chronic renal failure. However, it might also be seen as a repair process. PMID:18575881

  20. 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.

  1. 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.

  2. 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.

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

    PubMed

    Premnath, Priyatha; Venkatakrishnan, Krishnan; Tan, Bo

    2015-01-01

    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. PMID:26043430

  4. Programming cancer through phase-functionalized silicon based biomaterials

    PubMed Central

    Premnath, Priyatha; Venkatakrishnan, Krishnan; Tan, Bo

    2015-01-01

    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. PMID:26043430

  5. 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

  6. Morphological and functional interrelationships of articular cartilage matrices.

    PubMed Central

    Poole, C A; Flint, M H; Beaumont, B W

    1984-01-01

    The pericellular, territorial and interterritorial matrices of canine tibial cartilage have been identified ultrastructurally on the basis of their collagen fibre density and organisation, proteoglycan distribution and their structural response to experimentally applied compressive loads. In addition, a discrete pericellular capsule composed of fine, faintly banded fibrils is described which surrounds and encloses the pericellular matrix and chondrocytes of the middle and deep layers but not of the superficial layer. It is suggested that the fine fibrils which comprise this pericellular capsule represent some of the new minor collagen species recently localised in a similar position in hyaline cartilages. The densely compacted cupola which forms the articular pole of the capsule is frequently penetrated by a clearly defined pericellular channel, consistently orientated in the direction of the articular surface. Membrane-bound vesicles are observed in the pericellular matrix, within the lumen of the pericellular channel and accumulated in the territorial matrix immediately beyond the pericellular channel. The constancy of this distribution pattern strongly suggests a flow of material through the pericellular channel from the pericellular matrix to the territorial matrix and beyond, possibly in response to minute pressure gradients generated during compressive deformation of the non-distensible capsule. Furthermore, it is suggested that the random dispersal and subsequent rupture of matrix vesicles may represent a mechanism whereby chondrocytes, with limited mobility, could exercise homeostatic control over the cartilage matrix at some distance from the cell. Chondrocytes in the deeper layers of canine tibial cartilage are each surrounded by three distinct compartments, a pericellular matrix and capsule, a territorial matrix and an interterritorial matrix. The response of each of these concentric compartments to experimental load suggests that they function

  7. A test of cirrus ice crystal scattering phase functions

    NASA Astrophysics Data System (ADS)

    Field, P. R.; Baran, A. J.; Kaye, P. H.; Hirst, E.; Greenaway, R.

    2003-07-01

    In-situ ice crystal scattering has been measured in cirrus cloud with the Small Ice Detector laser scattering probe. Using light scattered from single particles (maximum dimension ~<100 μm) at 4-10° and 20-40° we have tested ice crystal scattering phase functions for spheres, hexagonal columns, hexagonal plates, polycrystals an aggregate of columns and an analytic function. We find that phase functions that lack a pronounced 22° halo are the best representatives for the example data presented here. Spherical ice particle phase functions do not satisfy the measurements.

  8. 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

  9. Atomistic simulations of P(NDI2OD-T2) morphologies: from single chain to condensed phases.

    PubMed

    Caddeo, Claudia; Fazzi, Daniele; Caironi, Mario; Mattoni, Alessandro

    2014-10-30

    We investigate theoretically the structure, crystallinity, and solubility of a high-mobility n-type semiconducting copolymer, P(NDI2OD-T2), and we propose a set of new force field parameters. The force field is reparametrized against density functional theory (DFT) calculations, with the aim to reproduce the correct torsional angles that govern the polymer chain flexibility and morphology. We simulate P(NDI2OD-T2) oligomers in different environments, namely, in vacuo, in the bulk phase, and in liquid toluene and chloronaphthalene solution. The choice of these solvents is motivated by the fact that they induce different kinds of molecular preaggregates during the casting procedures, resulting in variable device performances. Our results are in good agreement with the available experimental data; the polymer bulk structure, in which the chains are quite planar, is correcly reproduced, yet the isolated chains are flexible enough to fold in vacuo. We also calculate the solubility of P(NDI2OD-T2) in toluene and chloronaphthalene, predicting a much better solubility of the polymer in the latter, also in accordance to experimental observations. Different morphologies and dynamics of the oligomers in the two solvents have been observed. The proposed parameters make it possible to obtain the description of P(NDI2OD-T2) in different environments and can serve as a basis for extensive studies of this polymer semiconductor, such as, for example, the dynamics of aggregation in solvent. PMID:25264852

  10. 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.

  11. Phylogenetic relationships of fig wasps pollinating functionally dioecious Ficus based on mitochondrial DNA sequences and morphology.

    PubMed

    Weiblen, G D

    2001-04-01

    The obligate mutualism between pollinating fig wasps in the family Agaonidae (Hymenoptera: Chalcidoidea) and Ficus species (Moraceae) is often regarded as an example of co-evolution but little is known about the history of the interaction, and understanding the origin of functionally dioecious fig pollination has been especially difficult. The phylogenetic relationships of fig wasps pollinating functionally dioecious Ficus were inferred from mitochondrial cytochrome oxidase gene sequences (mtDNA) and morphology. Separate and combined analyses indicated that the pollinators of functionally dioecious figs are not monophyletic. However, pollinator relationships were generally congruent with host phylogeny and support a revised classification of Ficus. Ancestral changes in pollinator ovipositor length also correlated with changes in fig breeding systems. In particular, the relative elongation of the ovipositor was associated with the repeated loss of functionally dioecious pollination. The concerted evolution of interacting morphologies may bias estimates of phylogeny based on female head characters, but homoplasy is not so strong in other morphological traits. The lesser phylogenetic utility of morphology than of mtDNA is not due to rampant convergence in morphology but rather to the greater number of potentially informative characters in DNA sequence data; patterns of nucleotide substitution also limit the utility of mtDNA findings. Nonetheless, inferring the ancestral associations of fig pollinators from the best-supported phylogeny provided strong evidence of host conservatism in this highly specialized mutualism.

  12. Use of morphological characteristics to define functional groups of predatory fishes in the Celtic Sea.

    PubMed

    Reecht, Y; Rochet, M-J; Trenkel, V M; Jennings, S; Pinnegar, J K

    2013-08-01

    An ecomorphological method was developed, with a focus on predation functions, to define functional groups in the Celtic Sea fish community. Eleven functional traits, measured for 930 individuals from 33 species, led to 11 functional groups. Membership of functional groups was linked to body size and taxonomy. For seven species, there were ontogenetic changes in group membership. When diet composition, expressed as the proportions of different prey types recorded in stomachs, was compared among functional groups, morphology-based predictions accounted for 28-56% of the interindividual variance in prey type. This was larger than the 12-24% of variance that could be explained solely on the basis of body size.

  13. 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

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

    PubMed

    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 showed

  15. 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

  16. The phase-integral method for radiative transfer problems with highly-peaked phase functions

    NASA Technical Reports Server (NTRS)

    Fricke, C. L.

    1978-01-01

    Complete solutions to the radiative transfer equation, including both azimuth and depth dependence, are provided by the discrete-ordinate method of Chandrasekhar, but these solutions are often limited because of large computer requirements. This paper presents a 'phase-integral' method which greatly reduces the number of discrete ordinates needed in the solution for highly peaked phase functions. A composite quadrature method is shown to be effective in further reducing the number of discrete ordinates required for highly anisotropic phase functions. Examples are given to indicate convergence requirements and expected accuracy in the complete solution for Henyey-Greenstein and cloud-type phase functions.

  17. [Ontogenetic aspects of morphological and functional characteristics of the thyroid gland in birds].

    PubMed

    Pateiuk, A V; Kuznik, B I; Rusaeva, N S; Baranchugova, L M

    2008-01-01

    One can distinguish two most important periods in postnatal ontogenesis of the thyroid gland in birds. On the 5th postnatal day dramatic enhancement of adenohypophyseal endocrine functioning causes thyrocitic activation, which results in elevated levels of the thyroid hormones. The morphological and functional peak of the thyroid gland is within 3-12 months. Old birds manifest reduced production of the thyroid-stimulating hormone and show morphological changes in the parenchyma and stroma of the thyroid gland which eventually result in diminished production of the thyroid hormones.

  18. Morphologies of Primary Silicon in Hypereutectic Al-Si Alloys: Phase-Field Simulation Supported by Key Experiments

    NASA Astrophysics Data System (ADS)

    Wang, Kai; Wei, Ming; Zhang, Lijun; Du, Yong

    2016-04-01

    We realized a three-dimensional visualization of the morphology evolution and the growth behavior of the octahedral primary silicon in hypereutectic Al-20wtpctSi alloy during solidification in a real length scale by utilizing the phase-field simulation coupled with CALPHAD databases, and supported by key experiments. Moreover, through two-dimensional cut of the octahedral primary silicon at random angles, different morphologies observed in experiments, including triangle, square, trapezoid, rhombic, pentagon, and hexagon, were well reproduced.

  19. 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.

  20. 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

  1. 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

  2. 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. PMID:20352827

  3. 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

    2015-01-01

    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.

  4. Quantifying phase function influence in subdiffusively backscattered light.

    PubMed

    Bodenschatz, Nico; Krauter, Philipp; Liemert, André; Kienle, Alwin

    2016-03-01

    Light backscattering at short source-detector separations is considerably influenced by the scattering phase function of a turbid medium. We seek to more precisely relate a medium's subdiffusive backscattering to the angular scattering characteristics of its microstructure. First, we demonstrate the inability of the scattering asymmetry g1 = < cos θ > to predict phase function influence on backscattering and reveal ambiguities related to the established phase function parameter γ. Through the use of high-order similarity relations, we introduce a new parameter that more accurately relates a scattering phase function to its subdiffusive backscattering intensity. Using extensive analytical forward calculations based on solutions to the radiative transfer equation in the spatial domain and spatial frequency domain, we demonstrate the superiority of our empirically derived quantifier σ over the established parameter γ. PMID:26968384

  5. 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.

  6. A three parameter analytic phase function for multiple scattering calculations

    NASA Technical Reports Server (NTRS)

    Kattawar, G. W.

    1974-01-01

    A simple procedure was developed to fit the first three moments of an actual phase function with a three parameter analytic phase function. The exact Legendre Polynomial decomposition of this function is, suitable for multiple scattering calculations. The use of this function is expected to yield excellent flux values at all depths within a medium. Since it is capable of reproducing the glory, it can be used in synthetic spectra computations from planetary atmospheres. Accurate asymptotic radiance values can also be achieved as long as the single scattering albedo omega sub 0 is greater than or equal to 0.9.

  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. Elevated rates of morphological and functional diversification in reef-dwelling haemulid fishes.

    PubMed

    Price, Samantha A; Tavera, Jose J; Near, Thomas J; Wainwright, Peter C

    2013-02-01

    The relationship between habitat complexity and species richness is well established but comparatively little is known about the evolution of morphological diversity in complex habitats. Reefs are structurally complex, highly productive shallow-water marine ecosystems found in tropical (coral reefs) and temperate zones (rocky reefs) that harbor exceptional levels of biodiversity. We investigated whether reef habitats promote the evolution of morphological diversity in the feeding and locomotion systems of grunts (Haemulidae), a group of predominantly nocturnal fishes that live on both temperate and tropical reefs. Using phylogenetic comparative methods and statistical analyses that take into account uncertainty in phylogeny and the evolutionary history of reef living, we demonstrate that rates of morphological evolution are faster in reef-dwelling haemulids. The magnitude of this effect depends on the type of trait; on average, traits involved in the functional systems for prey capture and processing evolve twice as fast on reefs as locomotor traits. This result, along with the observation that haemulids do not exploit unique feeding niches on reefs, suggests that fine-scale trophic niche partitioning and character displacement may be driving higher rates of morphological evolution. Whatever the cause, there is growing evidence that reef habitats stimulate morphological and functional diversification in teleost fishes. PMID:23356614

  9. The ratio of molecular to atomic gas in spiral galaxies as a function of morphological type

    NASA Technical Reports Server (NTRS)

    Knezek, Patricia M.; Young, Judith S.

    1990-01-01

    In order to gain an understanding of the global processes which influence cloud and star formation in disk galaxies, it is necessary to determine the relative amounts of atomic, molecular, and ionized gas both as a function of position in galaxies and from galaxy to galaxy. With observations of the CO distributions in over 200 galaxies now completed as part of the Five College Radio Astronomy Observatory (FCRAO) Extragalactic CO Survey (Young et al. 1989), researchers are finally in a position to determine the type dependence of the molecular content of spiral galaxies, along with the ratio of molecular to atomic gas as a function of type. Do late type spirals really have more gas than early types when the molecular gas content is included. Researchers conclude that there is more than an order of magnitude decrease in the ratio of molecular to atomic gas mass as a function of morphological type from Sa-Sd; an average Sa galaxy has more molecular than atomic gas, and an average Sc has less. Therefore, the total interstellar gas mass to blue luminosity ratio, M sub gas/L sub B, increases by less than a factor of two as a function of type from Sa-Sd. The dominant effect found is that the phase of the gas in the cool interstellar medium (ISM) varies along the Hubble sequence. Researchers suggest that the more massive and centrally concentrated galaxies are able to achieve a molecular-dominated ISM through the collection of more gas in the potential. That gas may then form molecular clouds when a critical density is exceeded. The picture which these observations support is one in which the conversion of atomic gas to molecular gas is a global process which depends on large scale dynamics (cf Wyse 1986). Among interacting and merging systems, researchers find considerable scatter in the M(H2)/M(HI) ratio, with the mean ratio similar to that in the early type galaxies. The high global ratio of molecular to atomic gas could result from the removal of HI gas, the enhanced

  10. 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

  11. 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. PMID:17229537

  12. 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

  13. Functional and morphological assessment of diaphragm innervation by phrenic motor neurons.

    PubMed

    Martin, Melanie; Li, Ke; Wright, Megan C; Lepore, Angelo C

    2015-01-01

    This protocol specifically focuses on tools for assessing phrenic motor neuron (PhMN) innervation of the diaphragm at both the electrophysiological and morphological levels. Compound muscle action potential (CMAP) recording following phrenic nerve stimulation can be used to quantitatively assess functional diaphragm innervation by PhMNs of the cervical spinal cord in vivo in anesthetized rats and mice. Because CMAPs represent simultaneous recording of all myofibers of the whole hemi-diaphragm, it is useful to also examine the phenotypes of individual motor axons and myofibers at the diaphragm NMJ in order to track disease- and therapy-relevant morphological changes such as partial and complete denervation, regenerative sprouting and reinnervation. This can be accomplished via whole-mount immunohistochemistry (IHC) of the diaphragm, followed by detailed morphological assessment of individual NMJs throughout the muscle. Combining CMAPs and NMJ analysis provides a powerful approach for quantitatively studying diaphragmatic innervation in rodent models of CNS and PNS disease. PMID:26066371

  14. 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.

  15. 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. PMID:27111868

  16. 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.

  17. Modeling the atomic-scale structure, stability, and morphological transformations in the tetragonal phase of LaVO4

    NASA Astrophysics Data System (ADS)

    Gouveia, Amanda F.; Ferrer, Mateus M.; Sambrano, Júlio R.; Andrés, Juan; Longo, Elson

    2016-09-01

    In this communication, a systematic study of the surface structure, including energy management during morphological transformations of tetragonal phase of LaVO4, has been carried out. For this study, we combined experimental findings and first-principles calculations to develop a Wulff construction model. Our findings can help further understand the synthetic control of crystal shape via tuning of surface chemistry.

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

    PubMed

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

    2015-01-01

    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 Mn (x) (+) 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 MnO x 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 MnO x species on the calcination temperature and the presence of an oxidizing or neutral atmosphere. Furthermore, to demonstrate the application potential of the synthesized MnO x 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

  19. 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

  20. Morphology and Dynamics of Jets of Comet 67P Churyumov-Gerasimenko: Early Phase Development

    NASA Astrophysics Data System (ADS)

    Lin, Zhong-Yi; Ip, Wing-Huen; Lai, Ian-Lin; Lee, Jui-Chi; Pajola, Maurizio; Lara, Luisa; Gutierrez, Pedro; Rodrigo, Rafael; Bodewits, Dennis; A'Hearn, Mike; Vincent, Jean-Baptiste; Agarwal, Jessica; Keller, Uwe; Mottola, Stefano; Bertini, Ivano; Lowry, Stephen; Rozek, Agata; Liao, Ying; Rosetta Osiris Coi Team

    2015-04-01

    The scientific camera, OSIRIS (Optical, Spectroscopic, and Infrared Remote Imaging System), onboard the Rosetta spacecraft comprises a Narrow Angle Camera (NAC) for nucleus surface and dust studies and a Wide Angle Camera (WAC) for the wide field of dust and gas coma investigations. The dynamical behavior of jets in the dust coma continuously monitored by using dust filters from the arrival at the comet (August 2014) throughout the mapping phase (Oct. 2014) is described here. The analysis will cover the study of the time variability of jets, the source regions of these jets, the excess brightness of jets relative to the averaged coma brightness, and the brightness distribution of dust jets along the projected distance. The jets detected between August and September originated mostly from the neck region (Hapi). Morphological changes appeared over a time scale of several days in September. The brightness slope of the dust jets is much steeper than the background coma. This might be related to the sublimation or fragmentation of the emitted dust grains. Inter-comparison with results from other experiments will be necessary to understand the difference between the dust emitted from Hapi and those from the head and the body of the nucleus surface. The physical properties of the Hapi jets will be compared to dust jets (and their source regions) to emerge as comet 67P moves around the perihelion.

  1. 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

  2. Distinguishing bicontinuous lipid cubic phases from isotropic membrane morphologies using (31)P solid-state NMR spectroscopy.

    PubMed

    Yang, Yu; Yao, Hongwei; Hong, Mei

    2015-04-16

    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 line shapes, bicontinuous lipid cubic phases are more difficult to discern, since the static NMR spectra of cubic-phase lipids consist of an isotropic (31)P or (2)H 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 (31)P chemical shift line shapes of oriented cubic-phase membranes in the limit of slow lateral diffusion. We then show that (31)P T2 relaxation times differ significantly between isotropic micelles and cubic-phase membranes: the latter exhibit 2 orders of magnitude shorter T2 relaxation times. These differences are explained by the different time scales of lipid lateral diffusion on the cubic-phase surface versus the time scales 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 (31)P 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

  3. Background field functional renormalization group for absorbing state phase transitions.

    PubMed

    Buchhold, Michael; Diehl, Sebastian

    2016-07-01

    We present a functional renormalization group approach for the active to inactive phase transition in directed percolation-type systems, in which the transition is approached from the active, finite density phase. By expanding the effective potential for the density field around its minimum, we obtain a background field action functional, which serves as a starting point for the functional renormalization group approach. Due to the presence of the background field, the corresponding nonperturbative flow equations yield remarkably good estimates for the critical exponents of the directed percolation universality class, even in low dimensions. PMID:27575107

  4. Background field functional renormalization group for absorbing state phase transitions

    NASA Astrophysics Data System (ADS)

    Buchhold, Michael; Diehl, Sebastian

    2016-07-01

    We present a functional renormalization group approach for the active to inactive phase transition in directed percolation-type systems, in which the transition is approached from the active, finite density phase. By expanding the effective potential for the density field around its minimum, we obtain a background field action functional, which serves as a starting point for the functional renormalization group approach. Due to the presence of the background field, the corresponding nonperturbative flow equations yield remarkably good estimates for the critical exponents of the directed percolation universality class, even in low dimensions.

  5. How does morphology impact on diastolic function in hypertrophic cardiomyopathy? A single centre experience

    PubMed Central

    Finocchiaro, Gherardo; Haddad, Francois; Pavlovic, Aleksandra; Magavern, Emma; Sinagra, Gianfranco; Knowles, Joshua W; Myers, Jonathan; Ashley, Euan A

    2014-01-01

    Objectives It is unclear if morphology impacts on diastole in hypertrophic cardiomyopathy (HCM). We sought to determine the relationship between various parameters of diastolic function and morphology in a large HCM cohort. Setting Tertiary referral centre from Stanford, California, USA. Partecipants 383 patients with HCM and normal systolic function between 1999 and 2011. A group of 100 prospectively recruited age-matched and sex-matched healthy participants were used as controls. Primary and secondary outcome measures Echocardiograms were assessed by two blinded board-certified cardiologists. HCM morphology was classified as described in the literature (reverse, sigmoid, symmetric, apical and undefined). Results Reverse curvature morphology was most commonly observed (218 (57%). Lateral mitral annular E′<12 cm/s was present in 86% of reverse, 88% of sigmoid, 79% of symmetric, 86% of apical and 81% of undefined morphology, p=0.65. E/E′ was similarly elevated (E/E′: 12.3±7.9 in reverse curvature, 12.1±6.1 in sigmoid, 12.7±9.5 in symmetric, 9.4±4.0 in apical, 12.7±7.9 in undefined morphology, p=0.71) and indexed left atrial volume (LAVi)>40 mL/m2 was present in 47% in reverse curvature, 33% in sigmoid, 32% in symmetric, 37% in apical and 32% in undefined, p=0.09. Each morphology showed altered parameters of diastolic function when compared with the control population. Left ventricular (LV) obstruction was independently associated with all three diastolic parameters considered, in particular with LAVi>40 mL/m2 (OR 2.04 (95% CI 1.23 to 3.39), p=0.005), E/E′>15 (OR 4.66 (95% CI 2.51 to 8.64), p<0.001) and E′<8 (OR 2.55 (95% CI 1.42 to 4.53), p=0.001). Other correlates of diastolic dysfunction were age, LV wall thickness and moderate-to-severe mitral regurgitation. Conclusions In HCM, diastolic dysfunction is present to similar degrees independently from the morphological pattern. The main correlates of diastolic dysfunction are LV obstruction, age

  6. 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.

  7. Role of Acid Functionality and Placement on Morphological Evolution and Strengthening of Acid Copolymers

    NASA Astrophysics Data System (ADS)

    Middleton, Luri Robert; Schwartz, Eric; Winey, Karen

    Functional polymers with specific interactions produce hierarchical morphologies that directly impact mechanical properties. We recently reported that the formation of acid-rich layered morphologies in precise poly(ethylene-co-acrylic acid) copolymers improves tensile strength. We now explore the generality of this phenomenon through variations in pendant acid chemistries, acid content and precision in placement of acid groups in polyethylene-based copolymers. In situ X-ray scattering measurements during tensile deformation reveal that the precision in acid group placement is critical to forming well-defined layered morphologies. This phenomenon was observed in both semi-crystalline and amorphous precise acid copolymers with varied acid chemistries (acrylic, geminal acrylic and phosphonic acids). Compositionally identical polymers but with pseudo random acid placement do not form layered morphologies. Acid chemistry and acid content influence morphological evolution predominately though modification of the copolymer Tg and crystallinity. Our results indicate that hierarchical layered structures, commensurate with improved mechanical properties, form in the presence of uniformity in chemical structure and sufficient chain mobility to strongly align during deformation.

  8. 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.

  9. Possible functional roles of phase resetting during walking.

    PubMed

    Yamasaki, Taiga; Nomura, Taishin; Sato, Shunsuke

    2003-06-01

    The walking rhythm is known to show phase shift or "reset" in response to external impulsive perturbations. We tried to elucidate functional roles of the phase reset possibly used for the neural control of locomotion. To this end, a system with a double pendulum as a simplified model of the locomotor control and a model of bipedal locomotion were employed and analyzed in detail. In these models, a movement corresponding to the normal steady-state walking was realized as a stable limit cycle solution of the system. Unexpected external perturbations applied to the system can push the state point of the system away from its limit cycle, either outside or inside the basin of attraction of the limit cycle. Our mathematical analyses of the models suggested functional roles of the phase reset during walking as follows. Function 1: an appropriate amount of the phase reset for a given perturbation can contribute to relocating the system's state point outside the basin of attraction of the limit cycle back to the inside. Function 2: it can also be useful to reduce the convergence time (the time necessary for the state point to return to the limit cycle). In experimental studies during walking of animals and humans, the reset of walking rhythm induced by perturbations was investigated using the phase transition curve (PTC) or the phase resetting curve (PRC) representing phase-dependent responses of the walking. We showed, for the simple double-pendulum model, the existence of the optimal phase control and the corresponding PTC that could optimally realize the aforementioned functions in response to impulsive force perturbations. Moreover, possible forms of PRC that can avoid falling against the force perturbations were predicted by the biped model, and they were compared with the experimentally observed PRC during human walking. Finally, physiological implications of the results were discussed. PMID:12789495

  10. Substrate chemistry influences the morphology and biological function of adsorbed extracellular matrix assemblies.

    PubMed

    Sherratt, Michael J; Bax, Daniel V; Chaudhry, Shazia S; Hodson, Nigel; Lu, Jian R; Saravanapavan, Priya; Kielty, Cay M

    2005-12-01

    In addition to mediating cell signalling events, native extracellular matrix (ECM) assemblies interact with other ECM components, act as reservoirs for soluble signalling molecules and perform structural roles. The potential of native ECM assemblies in the manufacture of biomimetic materials has not been fully exploited due, in part, to the effects of substrate interactions on their morphology. We have previously demonstrated that the ECM components, fibrillin and type VI collagen microfibrils, exhibit substrate dependent morphologies on chemically and topographically variable heterogeneous surfaces. Using both cleaning and coating approaches on silicon wafers and glass coverslips we have produced chemically homogeneous, topographically similar substrates which cover a large amphiphilic range. Extremes of substrate amphiphilicity induced morphological changes in periodicity, curvature and lateral spreading which may mask binding sites or disrupt domain structure. Biological functionality, as assayed by the ability to support cell spreading, was significantly reduced for fibrillin microfibrils adsorbed on highly hydrophilic substrates (contact angle 20.7 degrees) compared with less hydrophilic (contact angle 38.3 degrees) and hydrophobic (contact angle 92.8 degrees) substrates. With an appropriate choice of surface chemistry, multifunctional ECM assemblies retain their native morphology and biological functionality.

  11. Optimising vitrification of human oocytes using multiple cryoprotectants and morphological and functional assessment.

    PubMed

    Seet, V Y K; Al-Samerria, S; Wong, J; Stanger, J; Yovich, J L; Almahbobi, G

    2013-01-01

    Oocyte vitrification is a clinical practice that allows preservation of fertility potential in women. Vitrification involves quick cooling using high concentrations of cryoprotectants to minimise freezing injuries. However, high concentrations of cryoprotectants have detrimental effects on oocyte quality and eventually the offspring. In addition, current assessment of oocyte quality after vitrification is commonly based only on the morphological appearance of the oocyte, raising concerns regarding its efficiency. Using both morphological and functional assessments, the present study investigated whether combinations of cryoprotectants at lower individual concentrations result in better cryosurvival rates than single cryoprotectants at higher concentrations. Surplus oocytes from IVF patients were vitrified within 24h after retrieval using the Cryotop method with several cryoprotectants, either individually or in combination. The morphological and functional quality of the vitrified oocytes was investigated using light microscopy and computer-based quantification of mitochondrial integrity, respectively. Oocyte quality was significantly higher using a combination of cryoprotectants than vitrification with individual cryoprotectants. In addition, the quality of vitrified oocyte varied depending on the cryoprotectants and type of combination used. The results of the present study indicate that observations based purely on the morphological appearance of the oocyte to assess the cryosurvival rate are insufficient and sometimes misleading. The outcome will have a significant implication in the area of human oocyte cryopreservation as an important approach for fertility preservation. PMID:22967503

  12. Multiple phase estimation in digital holographic interferometry using product cubic phase function

    NASA Astrophysics Data System (ADS)

    Kulkarni, Rishikesh; Rastogi, Pramod

    2013-10-01

    Digital holographic interferometry (DHI) involves multi-directional illumination of an object to measure the in-plane and out-of plane displacements simultaneously. This results in multiple interference phases which have to be reliably estimated. The paper proposes a method where the interference field is represented as sum of multicomponent quadratic phase signal. Subsequently, product cubic phase function (PCPF) is used to estimate the quadratic coefficients. Using these coefficients multiple interference phases are estimated. The applicability of this method in DHI is demonstrated with simulation results.

  13. Cerebral morphology and functional sparing after prenatal frontal cortex lesions in rats.

    PubMed

    Kolb, B; Cioe, J; Muirhead, D

    1998-03-01

    Rats were given suction lesions of the presumptive frontal cortex on embryonic day 18 (E18) and subsequently tested, as adults, on tests of spatial navigation (Morris water task, radial arm maze), motor tasks (Whishaw reaching task, beam walking), and locomotor activity. Frontal cortical lesions at E18 affected cerebral morphogenesis, producing unusual morphological structures including abnormal patches of neurons in the cortex and white matter as well as neuronal bridges between the hemispheres. A small sample of E18 operates also had hydrocephaly. The animals with E18 lesions without hydrocephalus were behaviorally indistinguishable from littermate controls. The results demonstrate that animals with focal lesions of the presumptive frontal cortex have gross abnormalities in cerebral morphology but the lesions leave the functions normally subserved by the frontal cortex in adult rats unaffected. The results are discussed in the context of a hypothesis regarding the optimal times for functional recovery from cortical injury. PMID:9578447

  14. The Effects of Crystal Phase and Particle Morphology of Calcium Phosphates on Proliferation and Differentiation of Human Mesenchymal Stromal Cells.

    PubMed

    Danoux, Charlène; Pereira, Daniel; Döbelin, Nicola; Stähli, Christoph; Barralet, Jake; van Blitterswijk, Clemens; Habibovic, Pamela

    2016-07-01

    Calcium phosphate (CaP) ceramics are extensively used for bone regeneration; however, their clinical performance is still considered inferior to that of patient's own bone. To improve the performance of CaP bone graft substitutes, it is important to understand the effects of their individual properties on a biological response. The aim of this study is to investigate the effects of the crystal phase and particle morphology on the behavior of human mesenchymal stromal cells (hMSCs). To study the effect of the crystal phase, brushite, monetite, and octacalcium phosphate (OCP) are produced by controlling the precipitation conditions. Brushite and monetite are produced as plate-shaped and as needle-shaped particles, to further investigate the effect of particle morphology. Proliferation of hMSCs is inhibited on OCP as compared to brushite and monetite in either morphology. Brushite needles consistently show the lowest expression of most osteogenic markers, whereas the expression on OCP is in general high. There is a trend toward a higher expression of the osteogenic markers on plate-shaped than on needle-shaped particles for both brushite and monetite. Within the limits of CaP precipitation, these data indicate the effect of both crystal phase and particle morphology of CaPs on the behavior of hMSCs. PMID:27232450

  15. 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

  16. 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

  17. In vitro effects of pulmonary surfactant on macrophage morphology and function.

    PubMed

    Lepekha, L N; Alexandrova, E A; Erokhina, M V

    2012-02-01

    The effects of pulmonary surfactant on the morphology and functioning of young macrophages were studied on the model of monocyte/macrophage differentiation in vitro and on macrophages of the bronchial alveolar lavage fluid. Surfactant is not a differentiation inductor, but it stimulated the maturation and phagocytic activity of young macrophages. The stimulatory effect of surfactant on phagocytic activity of macrophages persisted even after its removal from the culture medium.

  18. 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.

  19. 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.

  20. 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

  1. 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. PMID:26205909

  2. Correlative morphologic and functional imaging for diagnosis, staging and follow up in AIDS: an overview.

    PubMed

    Brunetti, A; Soricelli, A; Rotondo, A; Alfano, B; Raman, R; Celentano, L; Di Chiro, G; Salvatore, M

    1995-09-01

    The immunocompromised patient can be affected by different opportunistic infections and tumors, that can involve all organ systems, and particularly, the central nervous system, the respiratory system, the gastrointestinal tract. The extreme variability of AIDS presentations requires a specific preparation and cooperation between the different diagnostic imaging specialists and a close collaboration with the clinicians. With AIDS, different morphologic and functional imaging techniques can be used for detection of disease sites, assessment of the extent of the disease and monitoring of disease changes over time and response to treatment. The complexity of AIDS presentations is such that full integration of the complementary information obtained with different techniques could be most useful. Image registration (coregistration, fusion) indicates approaches where precise spatial cross-references are obtained, in order to combine the information acquired with different imaging modalities, in particular by blending morphologic CT/MRI data with functional SPET/PET data. In this paper, an overview of the developments in the field of "image fusion" follows some comments on the results of morphologic and functional assessment of brain, chest and abdominal diseases in the course of AIDS, as illustrative examples of the potential benefits of multimodality image correlation.

  3. 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.

  4. Morphology and Functional Anatomy of the Recurrent Laryngeal Nerve with Extralaryngeal Terminal Bifurcation

    PubMed Central

    Dogan, Sami

    2016-01-01

    Anatomical variations of the recurrent laryngeal nerve (RLN), such as an extralaryngeal terminal bifurcation (ETB), threaten the safety of thyroid surgery. Besides the morphology of the nerve branches, intraoperative evaluation of their functional anatomy may be useful to preserve motor activity. We exposed 67 RLNs in 36 patients. The main trunk, bifurcation point, and terminal branches of bifid nerves were macroscopically determined and exposed during thyroid surgery. The functional anatomy of the nerve branches was evaluated by intraoperative nerve monitoring (IONM). Forty-six RLNs with an ETB were intraoperatively exposed. The bifurcation point was located along the prearterial, arterial, and postarterial segments in 11%, 39%, and 50% of bifid RLNs, respectively. Motor activity was determined in all anterior branches. The functional anatomy of terminal branches detected motor activity in 4 (8.7%) posterior branches of 46 bifid RLNs. The motor activity in posterior branches created a wave amplitude at 25–69% of that in the corresponding anterior branches. The functional anatomy of bifid RLNs demonstrated that anterior branches always contained motor fibres while posterior branches seldom contained motor fibres. The motor activity of the posterior branch was weaker than that of the anterior branch. IONM may help to differentiate between motor and sensory functions of nerve branches. The morphology and functional anatomy of all nerve branches must be preserved to ensure a safer surgery. PMID:27493803

  5. Block copolymer morphologies in dye-sensitized solar cells: probing the photovoltaic structure-function relation.

    PubMed

    Crossland, Edward J W; Nedelcu, Mihaela; Ducati, Caterina; Ludwigs, Sabine; Hillmyer, Marc A; Steiner, Ullrich; Snaith, Henry J

    2009-08-01

    We integrate mesostructured titania arrays into dye-sensitized solar cells by replicating ordered, oriented one-dimensional (1D) columnar and three-dimensional (3D) bicontinuous gyroid block copolymer phases. The solar cell performance, charge transport, and recombination are investigated. We observe faster charge transport in 1D "wires" than through 3D gyroid arrays. However, owing to their structural instability, the surface area of the wire arrays is low, inhibiting the solar cell performance. The gyroid morphology, on the other hand, outperforms the current state-of-the-art mesoporous nanoparticle films.

  6. The relation between geometric morphometrics and functional morphology, as explored by Procrustes interpretation of individual shape measures pertinent to function.

    PubMed

    Bookstein, Fred L

    2015-01-01

    A frequent concern in today's functional morphology is the relation of a landmark configuration to some a priori index or suite of indices of function. When an index is itself a generic mathematical or biomechanical shape function of landmark locations, meaning a dimensionless expression that has a nonzero gradient everywhere in the feasible region of morphospace, the question becomes sharper: how can we exploit it as a reference direction for representations within the realm of the customary geometric morphometric (GM) analyses? This article argues that the only valid approach to this problem is geometric, not statistical: to represent any such a priori index by way of its differential (its gradient) calculated as an explicit vector in the Procrustes dual space of the complete list of landmarks whether or not involved in the formulation of the index. Interpretation of the index follows by comparing its direction after this embedding with other interesting directions in the same shape space, such as principal warps, relative warps, group mean shape contrasts, specific form factors extracted independently, or directions corresponding to other functional indices. Here, I work an artificial but realistic example of this technique in complete detail: the construction of a Procrustes shape formula exactly aligned with a specific angle among three landmarks within an arbitrary configuration of six. A closing discussion traces the spirit of this intervention to comments by W. W. Howells and C. E. Oxnard, originally intended for anthropometric contexts other than GM, on the different purposes of systematics and functional morphology. PMID:25339502

  7. The relation between geometric morphometrics and functional morphology, as explored by Procrustes interpretation of individual shape measures pertinent to function.

    PubMed

    Bookstein, Fred L

    2015-01-01

    A frequent concern in today's functional morphology is the relation of a landmark configuration to some a priori index or suite of indices of function. When an index is itself a generic mathematical or biomechanical shape function of landmark locations, meaning a dimensionless expression that has a nonzero gradient everywhere in the feasible region of morphospace, the question becomes sharper: how can we exploit it as a reference direction for representations within the realm of the customary geometric morphometric (GM) analyses? This article argues that the only valid approach to this problem is geometric, not statistical: to represent any such a priori index by way of its differential (its gradient) calculated as an explicit vector in the Procrustes dual space of the complete list of landmarks whether or not involved in the formulation of the index. Interpretation of the index follows by comparing its direction after this embedding with other interesting directions in the same shape space, such as principal warps, relative warps, group mean shape contrasts, specific form factors extracted independently, or directions corresponding to other functional indices. Here, I work an artificial but realistic example of this technique in complete detail: the construction of a Procrustes shape formula exactly aligned with a specific angle among three landmarks within an arbitrary configuration of six. A closing discussion traces the spirit of this intervention to comments by W. W. Howells and C. E. Oxnard, originally intended for anthropometric contexts other than GM, on the different purposes of systematics and functional morphology.

  8. Low-shear modelled microgravity environment maintains morphology and differentiated functionality of primary porcine hepatocyte cultures.

    PubMed

    Nelson, Leonard J; Walker, Simon W; Hayes, Peter C; Plevris, John N

    2010-01-01

    Hepatocytes cultured in conventional static culture rapidly lose polarity and differentiated function. This could be explained by gravity-induced sedimentation, which prevents formation of complete three-dimensional (3D) cell-cell/cell-matrix interactions and disrupts integrin-mediated signals (including the most abundant hepatic integrin alpha(5)beta(1)), important for cellular polarity and differentiation. Cell culture in a low fluid shear modelled microgravity (about 10(-2) g) environment promotes spatial colocation/self-aggregation of dissociated cells and induction of 3D differentiated liver morphology. Previously, we demonstrated the utility of a NASA rotary bioreactor in maintaining key metabolic functions and 3D aggregate formation of high-density primary porcine hepatocyte cultures over 21 days. Using serum-free chemically defined medium, without confounding interactions of exogenous bioscaffolding or bioenhancing surface materials, we investigated features of hepatic cellular polarity and differentiated functionality, including expression of hepatic integrin alpha(5), as markers of functional morphology. We report here that in the absence of exogenous biomatrix scaffolding, hepatocytes cultured in serum-free chemically defined medium in a microgravity environment rapidly (<24 h) form macroscopic (2-5 mm), compacted 3D hepatospheroid structures consisting of a shell of glycogen-positive viable cells circumscribing a core of eosinophilic cells. The spheroid shell layers exhibited ultrastructural, morphological and functional features of differentiated, polarized hepatic tissue including strong expression of the integrin alpha(5) subunit, functional bile canaliculi, albumin synthesis, and fine ultrastructure reminiscent of in vivo hepatic tissue. The low fluid shear microgravity environment may promote tissue-like self-organization of dissociated cells, and offer advantages over spheroids cultured in conventional formats to delineate optimal conditions for

  9. 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.

  10. Antennal courtship and functional morphology of tyloids in the parasitoid wasp Syrphoctonus tarsatorius (Hymenoptera: Ichneumonidae: Diplazontinae).

    PubMed

    Steiner, Salome M; Kropf, Christian; Graber, Werner; Nentwig, Wolfgang; Klopfstein, Seraina

    2010-01-01

    Courtship behaviour and associated morphological characters are believed to evolve under diversifying sexual selection. In Hymenoptera, sexually dimorphic antennal structures, the 'tyloids', show a large variability. Although crucial for functional interpretation, the link between tyloid morphology and courtship behaviour has gained only limited attention. Here, we investigate antennal morphology and antennal courtship in the parasitoid wasp Syrphoctonus tarsatorius (Hymenoptera: Ichneumonidae: Diplazontinae). We confirm the glandular nature of the tyloids by light and scanning electron microscopy. Moreover, we report a new form of antennation during courtship, antennal double-coiling, which links morphology and behaviour by bringing the tyloids in direct contact with the antennae of the female, thus probably facilitating the transfer of a contact pheromone. We show that a change in haemolymph pressure is the activator of the antennal movement and that it can be reproduced in the laboratory using amputated antennae. Investigations of antennal structure and movement in three additional hymenopteran species suggest that the number and location of tyloids coincide with the modality of antennal coiling. Our method for simulating antennal movement will enable retrieving information about courtship behaviour from museum specimens, thus leading to a better understanding of the evolution of courtship behaviour in Hymenoptera.

  11. 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.

  12. Functional morphology of the divided compound eye of the honeybee drone (Apis mellifera).

    PubMed

    Menzel, J G; Wunderer, H; Stavenga, D G

    1991-01-01

    Using different approaches, the functional morphology of the compound eye of the honeybee drone was examined. The drone exhibits an extended acute zone in the dorsal part of its eye. The following specializations were found here: enlarged facet diameters; smaller interommatidial angles; red-leaky screening pigment; enlarged rhabdom diameters; photopigment composition different from the drone's ventral eye region and the worker bee's eye. Thus, similar to other male insects, the drone compound eye is divided into a male-specific dorsal part and a ventral part resembling the worker bee's eye. The functional significance of the sex-specific acute zone is discussed with respect to mating behaviour. PMID:18621175

  13. Functional morphology of the divided compound eye of the honeybee drone (Apis mellifera).

    PubMed

    Menzel, J G; Wunderer, H; Stavenga, D G

    1991-01-01

    Using different approaches, the functional morphology of the compound eye of the honeybee drone was examined. The drone exhibits an extended acute zone in the dorsal part of its eye. The following specializations were found here: enlarged facet diameters; smaller interommatidial angles; red-leaky screening pigment; enlarged rhabdom diameters; photopigment composition different from the drone's ventral eye region and the worker bee's eye. Thus, similar to other male insects, the drone compound eye is divided into a male-specific dorsal part and a ventral part resembling the worker bee's eye. The functional significance of the sex-specific acute zone is discussed with respect to mating behaviour.

  14. 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

  15. Influence of the Substrate on the Crystalline Phase and Morphology of Poly (vinylidene Fluoride) (pvdf) Thin Film

    NASA Astrophysics Data System (ADS)

    Abdullah, Ibtisam Yahya; Yahaya, Muhammad; Jumali, Mohammad Hafizuddin Hj; Shanshool, Haider Mohammed

    2016-03-01

    The effect of substrate on the crystalline phase and morphology of the poly (vinylidene fluoride) (PVDF) thin film has been investigated. The solution of PVDF/Hexamethyl phosphoramide (HMPA) was deposited on four different substrates, namely, silicon (Si), glass (SiO2), indium tin oxide (ITO) coated glass and silver (Ag) coated glass respectively by using the spin coating technique. The crystalline structure was investigated using X-ray diffraction (XRD) and Fourier transform infrared (FTIR) techniques. The morphology was determined using scanning electron microscopy (SEM). XRD demonstrated that the structure of PVDF thin films on each substrate is β-phase with different orientations of the molecular chains. FTIR results confirmed XRD that the samples contain β-phase. SEM shows spherulites structure, which is rough and porous, besides, the size of spherulites and the porosity are different for each sample. The size of spherulites is in average diameter range (1-6μm) and this range is attributed to the β-phase. The nucleation process of β-phase on the various substrates attributed either to the match of polymer-substrate or to the electrostatic interaction. Among the substrates used, the ITO substrate exhibited a greater tendency for β-phase formation.

  16. 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.

  17. 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

  18. 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. PMID:26107629

  19. Time representation of mitochondrial morphology and function after acute spinal cord injury.

    PubMed

    Jia, Zhi-Qiang; Li, Gang; Zhang, Zhen-Yu; Li, Hao-Tian; Wang, Ji-Quan; Fan, Zhong-Kai; Lv, Gang

    2016-01-01

    Changes in mitochondrial morphology and function play an important role in secondary damage after acute spinal cord injury. We recorded the time representation of mitochondrial morphology and function in rats with acute spinal cord injury. Results showed that mitochondria had an irregular shape, and increased in size. Mitochondrial cristae were disordered and mitochondrial membrane rupture was visible at 2-24 hours after injury. Fusion protein mitofusin 1 expression gradually increased, peaked at 8 hours after injury, and then decreased to its lowest level at 24 hours. Expression of dynamin-related protein 1, amitochondrial fission protein, showed the opposite kinetics. At 2-24 hours after acute spinal cord injury, malondialdehyde content, cytochrome c levels and caspase-3 expression were increased, but glutathione content, adenosine triphosphate content, Na(+)-K(+)-ATPase activity and mitochondrial membrane potential were gradually reduced. Furthermore, mitochondrial morphology altered during the acute stage of spinal cord injury. Fusion was important within the first 8 hours, but fission played a key role at 24 hours. Oxidative stress was inhibited, biological productivity was diminished, and mitochondrial membrane potential and permeability were reduced in the acute stage of injury. In summary, mitochondrial apoptosis is activated when the time of spinal cord injury is prolonged.

  20. Time representation of mitochondrial morphology and function after acute spinal cord injury

    PubMed Central

    Jia, Zhi-qiang; Li, Gang; Zhang, Zhen-yu; Li, Hao-tian; Wang, Ji-quan; Fan, Zhong-kai; Lv, Gang

    2016-01-01

    Changes in mitochondrial morphology and function play an important role in secondary damage after acute spinal cord injury. We recorded the time representation of mitochondrial morphology and function in rats with acute spinal cord injury. Results showed that mitochondria had an irregular shape, and increased in size. Mitochondrial cristae were disordered and mitochondrial membrane rupture was visible at 2–24 hours after injury. Fusion protein mitofusin 1 expression gradually increased, peaked at 8 hours after injury, and then decreased to its lowest level at 24 hours. Expression of dynamin-related protein 1, amitochondrial fission protein, showed the opposite kinetics. At 2–24 hours after acute spinal cord injury, malondialdehyde content, cytochrome c levels and caspase-3 expression were increased, but glutathione content, adenosine triphosphate content, Na+-K+-ATPase activity and mitochondrial membrane potential were gradually reduced. Furthermore, mitochondrial morphology altered during the acute stage of spinal cord injury. Fusion was important within the first 8 hours, but fission played a key role at 24 hours. Oxidative stress was inhibited, biological productivity was diminished, and mitochondrial membrane potential and permeability were reduced in the acute stage of injury. In summary, mitochondrial apoptosis is activated when the time of spinal cord injury is prolonged. PMID:26981103

  1. The sharpest tools in the box? Quantitative analysis of conodont element functional morphology

    PubMed Central

    Jones, David; Evans, Alistair R.; Siu, Karen K. W.; Rayfield, Emily J.; Donoghue, Philip C. J.

    2012-01-01

    Conodonts have been considered the earliest skeletonizing vertebrates and their mineralized feeding apparatus interpreted as having performed a tooth function. However, the absence of jaws in conodonts and the small size of their oropharyngeal musculature limits the force available for fracturing food items, presenting a challenge to this interpretation. We address this issue quantitatively using engineering approaches previously applied to mammalian dentitions. We show that the morphology of conodont food-processing elements was adapted to overcome size limitations through developing dental tools of unparalleled sharpness that maximize applied pressure. Combined with observations of wear, we also show how this morphology was employed, demonstrating how Wurmiella excavata used rotational kinematics similar to other conodonts, suggesting that this occlusal style is typical for the clade. Our work places conodont elements within a broader dental framework, providing a phylogenetically independent system for examining convergence and scaling in dental tools. PMID:22418253

  2. 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/.

  3. Functional morphology of the bovid astragalus in relation to habitat: controlling phylogenetic signal in ecomorphology.

    PubMed

    Barr, W Andrew

    2014-11-01

    Bovid astragali are one of the most commonly preserved bones in the fossil record. Accordingly, astragali are an important target for studies seeking to predict the habitat preferences of fossil bovids based on bony anatomy. However, previous work has not tested functional hypotheses linking astragalar morphology with habitat while controlling for body size and phylogenetic signal. This article presents a functional framework relating the morphology of the bovid astragalus to habitat-specific locomotor ecology and tests four hypotheses emanating from this framework. Highly cursorial bovids living in structurally open habitats are hypothesized to differ from their less cursorial closed-habitat dwelling relatives in having (1) relatively short astragali to maintain rotational speed throughout the camming motion of the rotating astragalus, (2) a greater range of angular excursion at the hock, (3) relatively larger joint surface areas, and (4) a more pronounced "spline-and-groove" morphology promoting lateral joint stability. A diverse sample of 181 astragali from 50 extant species was scanned using a Next Engine laser scanner. Species were assigned to one of four habitat categories based on the published ecological literature. A series of 11 linear measurements and three joint surface areas were measured on each astragalus. A geometric mean body size proxy was used to size-correct the measurement data. Phylogenetic generalized least squares (PGLS) was used to test for differences between habitat categories while controlling for body size differences and phylogenetic signal. Statistically significant PGLS results support Hypotheses 1 and 2 (which are not mutually exclusive) as well as Hypothesis 3. No support was found for Hypothesis 4. These findings confirm that the morphology of the bovid astragalus is related to habitat-specific locomotor ecology, and that this relationship is statistically significant after controlling for body size and phylogeny. Thus, this study

  4. Monitoring molecular, functional and morphologic aspects of bone metastases using non-invasive imaging.

    PubMed

    Bauerle, Tobias; Komljenovic, Dorde; Semmler, Wolfhard

    2012-03-01

    Bone is among the most common locations of metastasis and therefore represents an important clinical target for diagnostic follow-up in cancer patients. In the pathogenesis of bone metastases, disseminated tumor cells proliferating in bone interact with the local microenvironment stimulating or inhibiting osteoclast and osteoblast activity. Non-invasive imaging methods monitor molecular, functional and morphologic changes in both compartments of these skeletal lesions - the bone and the soft tissue tumor compartment. In the bone compartment, morphologic information on skeletal destruction is assessed by computed tomography (CT) and radiography. Pathogenic processes of osteoclast and osteoblast activity, however, can be imaged using optical imaging, positron emission tomography (PET), single photon emission CT (SPECT) and skeletal scintigraphy. Accordingly, conventional magnetic resonance imaging (MRI) and CT as well as diffusion- weighted MRI and optical imaging are used to assess morphologic aspects on the macroscopic and cellular level of the soft tissue tumor compartment. Imaging methods such as PET, MR spectroscopy, dynamic contrast-enhanced techniques and vessel size imaging further elucidate on pathogenic processes in this compartment including information on metabolism and vascularization. By monitoring these aspects in bone lesions, new insights in the pathogenesis of skeletal metastases can be gained. In translation to the clinical situation, these novel methods for the monitoring of bone metastases might be applied in patients to improve follow-up of these lesions, in particular after therapeutic intervention. This review summarizes established and experimental imaging techniques for the monitoring of tumor and bone cell activity including molecular, functional and morphological aspects in bone metastases. PMID:22214500

  5. Morphological modification of MWCNT functionalized with HNO3/H2SO4 mixtures.

    PubMed

    Pistone, A; Ferlazzo, A; Lanza, M; Milone, C; Iannazzo, D; Piperno, A; Piperopoulos, E; Galvagno, S

    2012-06-01

    The acidic oxidation with HNO3/H2SO4 mixtures is widely reported as an effective method to functionalize multi-walled carbon nanotubes (MWCNT). Although effective, a bad control of the oxidation conditions frequently cause serious modifications of carbon nanotube network, limiting further potential applications. Investigations about the effect of functionalization operating conditions on the morphological, chemical and chemical-physical properties of MWCNT can be useful for a proper setting of oxidation reactions of MWCNT according to their specific applications. In this work the effect of HNO3/H2SO4 ratio on the morphological and chemical-physical properties and on the degree of functionalization of MWCNT was investigated. Electron microscopy, thermogravimetric, X-ray diffraction, titration and water dispersion analyses clearly revealed that the increase of the amount of concentrated sulphuric acid in the HNO3/H2SO4 mixture lead to an increase of the amount of functional groups on the MWCNT surface but also to an increase of structural damage in terms of tube cutting and generation of additional defects in the graphitic network of pristine PMID:22905576

  6. 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.

  7. Preleukemic phase of chronic myelogenous leukemia: morphologic and immunohistochemical characterization of 7 cases.

    PubMed

    Aye, Le Le; Loghavi, Sanam; Young, Ken H; Siddiqi, Imran; Yin, C Cameron; Routbort, Mark J; Liang, Mei; Eilerman, Keith; Medeiros, L Jeffrey; Brynes, Russell K; Bueso-Ramos, Carlos

    2016-04-01

    Patients with chronic myelogenous leukemia (CML) present typically with an elevated white blood cell count (WBC) and cytogenetic or molecular genetic evidence of t(9;22)/BCR-ABL1 fusion gene. Rarely, CML patients may present with a normal or mildly elevated WBC and are asymptomatic, and we describe 7 patients in this study. The WBC in these patients ranged from 3.6 to 14.3 K/mm(3) with 50% to 73% granulocytes and 0% blasts. In all patients, t(9;22)(q34;q11.2) was detected by conventional cytogenetics, and BCR-ABL1 fusion was shown, supporting the diagnosis of preleukemic CML (pre-CML). We compared these patients with a group of 5 cases of CML in chronic phase (CML-CP) and 5 bone marrow specimens with a leukemoid reaction (n=5). Reticulin, CD34, and CD61 immunostains were performed on all bone marrow biopsy specimens. Peripheral blood absolute basophilia (≥200/mm(3)) was noted in only 4 of 7 pre-CML cases, whereas it was present in all CML-CP cases and absent in leukemoid reaction cases. The mean ±SD of microvascular density of pre-CML cases (10.0 ± 4.3 vessels/200× field) was twice that of leukemoid reaction cases (5.0 ± 1.0) (P=.02; Student t test) but similar to that of CML-CP cases (12.5 ± 3.6). Microvessels in pre-CML, highlighted by CD34, were tortuous with abnormal branching, although to a lesser extent than those found in CML-CP. Microvessels in leukemoid reaction were generally straight. The percentage of small, hypolobated megakaryocytes, highlighted by CD61 in pre-CML, was 40%, 3 times that found in leukemoid reaction cases (13%) but less than that of CML-CP cases (86%). We conclude that pre-CML should be suspected in patients with a normal to mildly elevated WBC and absolute basophilia. Bone marrow examination can usually distinguish pre-CML from a leukemoid reaction based on the percentage of small, hypolobated megakaryocytes; microvascular density; and morphologic features. PMID:27040932

  8. 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

  9. 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

  10. 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.

  11. Three learning phases for radial-basis-function networks.

    PubMed

    Schwenker, F; Kestler, H A; Palm, G

    2001-05-01

    In this paper, learning algorithms for radial basis function (RBF) networks are discussed. Whereas multilayer perceptrons (MLP) are typically trained with backpropagation algorithms, starting the training procedure with a random initialization of the MLP's parameters, an RBF network may be trained in many different ways. We categorize these RBF training methods into one-, two-, and three-phase learning schemes. Two-phase RBF learning is a very common learning scheme. The two layers of an RBF network are learnt separately; first the RBF layer is trained, including the adaptation of centers and scaling parameters, and then the weights of the output layer are adapted. RBF centers may be trained by clustering, vector quantization and classification tree algorithms, and the output layer by supervised learning (through gradient descent or pseudo inverse solution). Results from numerical experiments of RBF classifiers trained by two-phase learning are presented in three completely different pattern recognition applications: (a) the classification of 3D visual objects; (b) the recognition hand-written digits (2D objects); and (c) the categorization of high-resolution electrocardiograms given as a time series (ID objects) and as a set of features extracted from these time series. In these applications, it can be observed that the performance of RBF classifiers trained with two-phase learning can be improved through a third backpropagation-like training phase of the RBF network, adapting the whole set of parameters (RBF centers, scaling parameters, and output layer weights) simultaneously. This, we call three-phase learning in RBF networks. A practical advantage of two- and three-phase learning in RBF networks is the possibility to use unlabeled training data for the first training phase. Support vector (SV) learning in RBF networks is a different learning approach. SV learning can be considered, in this context of learning, as a special type of one-phase learning, where

  12. Quantitative Evaluation of the Substantially Variable Morphology and Function of the Left Atrial Appendage and Its Relation with Adjacent Structures

    PubMed Central

    Liu, Xiao-Wei; Fan, Qiong-Ying; Zhang, Xue-Jing; Liu, Guo-Chao; Yang, Hai-Qing; Feng, Ping-Yong; Wang, Yong; Song, Peng

    2015-01-01

    Objective To investigate quantitatively the morphology, anatomy and function of the left atrial appendage (LAA) and its relation with adjacent structures. Materials and Methods A total of 860 patients (533 men, 62.0%, age 55.9±10.4 year) who had cardiac multidetector computed tomography angiography from May to October 2012 were enrolled for analysis. Results Seven types and 6 subtypes of LAA morphology were found with Type 2 being the most prevalent. Type 5 was more significantly (P<0.05) present in women (8.0%) than in men (4.2%). LAA orifice was oval in 81.5%, triangular in 7.3%, semicircular in 4%, water drop-like in 3.2%, round in 2.4% and foot-like in 1.6%. The LAA orifice had a significantly greater (P<0.01) major axis in men (24.79±3.81) than in women (22.68±4.07). The LAA orifice long axis was significantly (P<0.05) positively correlated with the height, weight and surface area of the patient. The LAA morphology parameters displayed strong positive correlation with the left atrium volume, aortic cross area long axis or LSPV long axis but poor correlation with the height, weight, surface area and vertebral body height of the patients. Four types of LAA ridge were identified: AI, AII, B and C with the distribution of 17.6%, 69.9%, 5.9% and 6.6%, respectively. The LAA had a significantly (P<0.05) greater distance from its orifice to the mitral ring in women than in men. The LAA had two filling and two emptying processes with the greatest volume at 45% phase but the least volume at 5% phase. The LAA maximal, minimal and emptying volumes were all significantly (P<0.05) positively correlated with the body height, weight and surface area, whereas the LAA ejection fraction had an inverse correlation with the LAA minimal volume but no correlation with the maximal volume. Conclusion The LAA has substantially variable morphologies and relation with the adjacent structures, which may be helpful in guiding the LAA trans-catheter occlusion or catheter ablation

  13. Low-temperature liquid phase reduced TiO2 nanotube arrays: synergy of morphology manipulation and oxygen vacancy doping for enhancement of field emission.

    PubMed

    Zhang, Xu-Qiang; Chen, Jian-Biao; Wang, Cheng-Wei; Liao, Ai-Zhen; Su, Xiao-Feng

    2015-05-01

    The partially reduced TiO(2) nanotube arrays (TNAs) are prepared via an uncomplicated and low-cost liquid phase reduction strategy using NaBH(4) as the reducing agent. By controlling and adjusting the reduction temperatures from 30 to 90 °C, the reduction treatment can not only change their surface morphology but also introduce oxygen vacancies into them, resulting in an optimized morphology, elevated Fermi-level, reduced effective work function and improved conductivity of the TNAs. Meanwhile, the thermal and long-term stability of oxygen vacancy are also investigated, indicating that the oxygen vacancies retain long-term stability from room temperature up to 150 °C. More interesting, partially reduced TNAs show drastically enhanced field emission (FE) performances including substantially decreased turn-on field from 18.86 to 1.53 V μm(-1), a high current density of 4.00 mA cm(-2) at 4.52 V μm(-1), and an excellent FE stability and repeatability. These very promising results are attributed to the combination of the optimized morphology and introduced oxygen vacancies, which can increase FE sites, reduce effective work function and increase conductivity.

  14. 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

    Nagler, Christina; 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

  15. 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

  16. 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

  17. 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.

  18. 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. PMID:21952737

  19. 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

  20. Carpal kinematics in quadrupedal monkeys: towards a better understanding of wrist morphology and function.

    PubMed

    Daver, Guillaume; Berillon, Gilles; Grimaud-Hervé, Dominique

    2012-01-01

    The purpose of this study is to provide new data on carpal kinematics in primates in order to deepen our understanding of the relationships between wrist morphology and function. To that end, we provide preliminary data on carpal kinematics in seven species of quadrupedal monkeys that have not been previously investigated in this regard (cercopithecoids, n = 4; ceboids, n = 3). We radiographed wrists from cadavers at their maximum radial and ulnar deviations, as well as at maximum flexion and extension. We took angular measurements to quantify the contribution of the mobility of the two main wrist joints (antebrachiocarpal and midcarpal) with respect to total wrist mobility. We also recorded qualitative observations. Our quantitative results show few clear differences among quadrupedal monkeys for radioulnar deviation and flexion-extension: all the primates studied exhibit a greater midcarpal mobility (approximately 54-83% of the total range of motion) than antebrachiocarpal mobility; however, we identified two patterns of carpal kinematics that show the functional impact of previously recognised morphological variations in quadrupedal monkeys. Firstly, qualitative results show that the partition that divides the proximal joint of the wrist in ceboids results in less mobility and more stability of the ulnar part of the wrist than is seen in cercopithecoids. Secondly, we show that the olive baboon specimen (Papio anubis) is characterised by limited antebrachiocarpal mobility for extension; this effect is likely the result of a radial process that projects on the scaphoid notch, as well as an intraarticular meniscus. Because of these close relationships between carpal kinematics and morphology in quadrupedal monkeys, we hypothesise that, to some extent, these functional tendencies are related to their locomotor hand postures.

  1. Explosive eversion and functional morphology of the duck penis supports sexual conflict in waterfowl genitalia

    PubMed Central

    Brennan, Patricia L. R.; Clark, Christopher J.; Prum, Richard O.

    2010-01-01

    Coevolution of male and female genitalia in waterfowl has been hypothesized to occur through sexual conflict. This hypothesis raises questions about the functional morphology of the waterfowl penis and the mechanics of copulation in waterfowl, which are poorly understood. We used high-speed video of phallus eversion and histology to describe for the first time the functional morphology of the avian penis. Eversion of the 20 cm muscovy duck penis is explosive, taking an average of 0.36 s, and achieving a maximum velocity of 1.6 m s−1. The collagen matrix of the penis is very thin and not arranged in an axial-orthogonal array, resulting in a penis that is flexible when erect. To test the hypothesis that female genital novelties make intromission difficult during forced copulations, we investigated penile eversion into glass tubes that presented different mechanical challenges to eversion. Eversion occurred successfully in a straight tube and a counterclockwise spiral tube that matched the chirality of the waterfowl penis, but eversion was significantly less successful into glass tubes with a clockwise spiral or a 135° bend, which mimicked female vaginal geometry. Our results support the hypothesis that duck vaginal complexity functions to exclude the penis during forced copulations, and coevolved with the waterfowl penis via antagonistic sexual conflict. PMID:20031991

  2. Effect of eda loss of function on upper jugal tooth morphology.

    PubMed

    Charles, Cyril; Pantalacci, Sophie; Peterkova, Renata; Tafforeau, Paul; Laudet, Vincent; Viriot, Laurent

    2009-02-01

    The Tabby/eda mice, which bear a loss of function mutation for the eda (ectodysplasinA) gene, are known to display developmental anomalies in organs with an ectodermal origin. Although the lower jugal (cheek) teeth of Tabby/eda mice have been extensively studied, upper teeth have never been investigated in detail. However, this may help us to further understand the function of the eda gene in tooth development. In this work, the shape and size of both the crown and the radicular system were studied in the Tabby/eda mice upper jugal teeth. To deal with the high morphological variability, we defined several morphotypes based on cusp numbers and position. Statistical tests were then performed within and between the different morphotypes to test the correlation between tooth size and morphology. Our analysis reveals that, as in lower teeth, eda is necessary to segment the dental lamina into three teeth with the characteristic size and proportions of the mouse. Nevertheless, since strong effects are observed in heterozygous upper teeth while lower are only mildly affected, it seems that the upper jaw is more sensitive than the lower jaw to the loss of eda function. Modifications in cusp number and the abnormal crown size of the teeth are clearly linked, and our results indicate a role of eda in cusp patterning. Moreover, we found that the Tabby mutation induces variations in the dental root pattern, sometimes associated with hypercementosis, suggesting a newly uncovered role played by eda in root patterning and formation.

  3. Morphological and functional remodeling of the neuromuscular junction by skeletal muscle PGC-1α

    PubMed Central

    Arnold, Anne-Sophie; Gill, Jonathan; Christe, Martine; Ruiz, Rocío; McGuirk, Shawn; St-Pierre, Julie; Tabares, Lucía; Handschin, Christoph

    2014-01-01

    The neuromuscular junction (NMJ) exhibits high morphological and functional plasticity. In the mature muscle, the relative levels of physical activity are major determinants of NMJ function. Classically, motor neuron-mediated activation patterns of skeletal muscle have been thought of as the major drivers of NMJ plasticity and the ensuing fiber-type determination in muscle. Here we use muscle-specific transgenic animals for the peroxisome proliferator-activated receptor γ co-activator 1α (PGC-1α) as a genetic model for trained mice to elucidate the contribution of skeletal muscle to activity-induced adaptation of the NMJ. We find that muscle-specific expression of PGC-1α promotes a remodeling of the NMJ, even in the absence of increased physical activity. Importantly, these plastic changes are not restricted to post-synaptic structures, but extended to modulation of pre-synaptic cell morphology and function. Therefore, our data indicate that skeletal muscle significantly contributes to the adaptation of the NMJ subsequent to physical activity. PMID:24686533

  4. Pit cells as liver-associated natural killer cells: morphology and function.

    PubMed

    Nakatani, Kazuki; Kaneda, Kenji; Seki, Shuichi; Nakajima, Yuji

    2004-03-01

    Pit cells are one type of hepatic sinusoidal cells, defined morphologically as large granular lymphocytes (LGLs) and functionally as liver-associated natural killer (NK) cells. They are situated inside the sinusoidal lumen, adhering to the endothelial cells and Kupffer cells. They contain multivesicular body-related dense granules and rod-cored vesicles. The number and size of granules and vesicles differ between hepatic NK cells and peripheral blood cells, suggesting possible differentiation of the latter into the former in the microenvironment of the liver. In addition to NK cells, natural killer T (NKT) cells are also abundant in the liver. They share several morphological properties with NK cells, and at least some are probably observed as pit cells under an electron microscope. NK cells recognize target cells with their surface receptors such as inhibitory and activating receptors. They exert antitumor functions by exocytosis of perforin/granzyme-containing granules, induction of death receptor-mediated apoptosis in target cells, and production of various cytokines that augment the activities of other immune cells. NKT cells play important roles in initiating and assisting the function of NK cells by producing interferon-gamma.

  5. Growth phase-regulated expression of bolA and morphology of stationary-phase Escherichia coli cells are controlled by the novel sigma factor sigma S.

    PubMed

    Lange, R; Hengge-Aronis, R

    1991-07-01

    The novel sigma factor (sigma S) encoded by rpoS (katF) is required for induction of many growth phase-regulated genes and expression of a variety of stationary-phase phenotypes in Escherichia coli. Here we demonstrate that wild-type cells exhibit spherical morphology in stationary phase, whereas rpoS mutant cells remain rod shaped and are generally larger. Size reduction of E. coli cells along the growth curve is a continuous and at least biphasic process, the second phase of which is absent in rpoS-deficient cells and correlates with induction of the morphogene bolA in wild-type cells. Stationary-phase induction of bolA is dependent on sigma S. The "gearbox" a characteristic sequence motif present in the sigma S-dependent growth phase- and growth rate-regulated bolAp1 promoter, is not recognized by sigma S, since stationary-phase induction of the mcbA promoter, which also contains a gearbox, does not require sigma S, and other sigma S-controlled promoters do not contain gearboxes. However, good homology to the potential -35 and -10 consensus sequences for sigma S regulation is found in the bolAp1 promoter.

  6. 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

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

    PubMed

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

    2015-11-01

    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

  8. [The influences of anterior disc displacement on oral mandibular function and morphology and their biological mechanisms].

    PubMed

    Xia, Wendi; Fu, Kiayuan

    2016-03-01

    Anterior disc displacement is a common subtype seen in temporomandibular disorders (TMD) patients. It may cause mandibular movement disorders, such as clicking of joint, intermittent closed lock, limitation of mouth opening, etc. These disorders may affect the life qualities of patients. Anterior disc displacement may also cause mandibular malformations, especially among adolescents, which may affect the growth of condyle, therefore may have a correlation with mandibular retrusion or mandibular deviation when grown up. This paper going to review the influences of anterior disc displacement on oral mandibular function and morphology and their biological mechanisms. PMID:26980658

  9. [The influences of anterior disc displacement on oral mandibular function and morphology and their biological mechanisms].

    PubMed

    Xia, Wendi; Fu, Kiayuan

    2016-03-01

    Anterior disc displacement is a common subtype seen in temporomandibular disorders (TMD) patients. It may cause mandibular movement disorders, such as clicking of joint, intermittent closed lock, limitation of mouth opening, etc. These disorders may affect the life qualities of patients. Anterior disc displacement may also cause mandibular malformations, especially among adolescents, which may affect the growth of condyle, therefore may have a correlation with mandibular retrusion or mandibular deviation when grown up. This paper going to review the influences of anterior disc displacement on oral mandibular function and morphology and their biological mechanisms.

  10. Clinically approved iron chelators influence zebrafish mortality, hatching morphology and cardiac function.

    PubMed

    Hamilton, Jasmine L; Hatef, Azadeh; Imran ul-Haq, Muhammad; Nair, Neelima; Unniappan, Suraj; Kizhakkedathu, Jayachandran N

    2014-01-01

    Iron chelation therapy using iron (III) specific chelators such as desferrioxamine (DFO, Desferal), deferasirox (Exjade or ICL-670), and deferiprone (Ferriprox or L1) are the current standard of care for the treatment of iron overload. Although each chelator is capable of promoting some degree of iron excretion, these chelators are also associated with a wide range of well documented toxicities. However, there is currently very limited data available on their effects in developing embryos. In this study, we took advantage of the rapid development and transparency of the zebrafish embryo, Danio rerio to assess and compare the toxicity of iron chelators. All three iron chelators described above were delivered to zebrafish embryos by direct soaking and their effects on mortality, hatching and developmental morphology were monitored for 96 hpf. To determine whether toxicity was specific to embryos, we examined the effects of chelator exposure via intra peritoneal injection on the cardiac function and gene expression in adult zebrafish. Chelators varied significantly in their effects on embryo mortality, hatching and morphology. While none of the embryos or adults exposed to DFO were negatively affected, ICL -treated embryos and adults differed significantly from controls, and L1 exerted toxic effects in embryos alone. ICL-670 significantly increased the mortality of embryos treated with doses of 0.25 mM or higher and also affected embryo morphology, causing curvature of larvae treated with concentrations above 0.5 mM. ICL-670 exposure (10 µL of 0.1 mM injection) also significantly increased the heart rate and cardiac output of adult zebrafish. While L1 exposure did not cause toxicity in adults, it did cause morphological defects in embryos at 0.5 mM. This study provides first evidence on iron chelator toxicity in early development and will help to guide our approach on better understanding the mechanism of iron chelator toxicity.

  11. Cranial functional morphology of fossil dogs and adaptation for durophagy in Borophagus and Epicyon (Carnivora, Mammalia).

    PubMed

    Tseng, Zhijie Jack; Wang, Xiaoming

    2010-11-01

    overall cranial mechanics of the derived borophagines is more similar to bone-cracking hyaenids and percrocutids than to their canid relatives, indicating convergence in both morphological form and functional capability. PMID:20799339

  12. 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

  13. Clinically Approved Iron Chelators Influence Zebrafish Mortality, Hatching Morphology and Cardiac Function

    PubMed Central

    Hamilton, Jasmine L.; Hatef, Azadeh; Imran ul-haq, Muhammad; Nair, Neelima; Unniappan, Suraj; Kizhakkedathu, Jayachandran N.

    2014-01-01

    Iron chelation therapy using iron (III) specific chelators such as desferrioxamine (DFO, Desferal), deferasirox (Exjade or ICL-670), and deferiprone (Ferriprox or L1) are the current standard of care for the treatment of iron overload. Although each chelator is capable of promoting some degree of iron excretion, these chelators are also associated with a wide range of well documented toxicities. However, there is currently very limited data available on their effects in developing embryos. In this study, we took advantage of the rapid development and transparency of the zebrafish embryo, Danio rerio to assess and compare the toxicity of iron chelators. All three iron chelators described above were delivered to zebrafish embryos by direct soaking and their effects on mortality, hatching and developmental morphology were monitored for 96 hpf. To determine whether toxicity was specific to embryos, we examined the effects of chelator exposure via intra peritoneal injection on the cardiac function and gene expression in adult zebrafish. Chelators varied significantly in their effects on embryo mortality, hatching and morphology. While none of the embryos or adults exposed to DFO were negatively affected, ICL -treated embryos and adults differed significantly from controls, and L1 exerted toxic effects in embryos alone. ICL-670 significantly increased the mortality of embryos treated with doses of 0.25 mM or higher and also affected embryo morphology, causing curvature of larvae treated with concentrations above 0.5 mM. ICL-670 exposure (10 µL of 0.1 mM injection) also significantly increased the heart rate and cardiac output of adult zebrafish. While L1 exposure did not cause toxicity in adults, it did cause morphological defects in embryos at 0.5 mM. This study provides first evidence on iron chelator toxicity in early development and will help to guide our approach on better understanding the mechanism of iron chelator toxicity. PMID:25329065

  14. The impact of oxygen on the morphology of gas-phase prepared Au nanoparticles

    SciTech Connect

    Pohl, D.; Surrey, A.; Schultz, L.; Rellinghaus, B.

    2012-12-24

    We present an easy procedure for the synthesis of single crystalline gold nanoparticles with a mean diameter of 4 nm using a DC-sputtering in an argon-oxygen gas mixture. Morphology population statistics have been determined to quantify the influence of oxygen. It is found that the particles undergo a structural transition from predominantly icosahedral to single crystalline particles with increasing amount of oxygen. Aberration-corrected high-resolution transmission electron microscopy investigation proves that likewise prepared single crystalline nanoparticles are defect and oxygen free. In contrast, the icosahedral particles prepared with pure argon show the presence of edge dislocations pointing to an energetic disfavoring already at these relatively small particle sizes. This morphology control of clean and uncovered Au nanoparticles provides a high application potential, e.g., for studying the influence of the particle morphology on plasmonic and catalytic properties.

  15. 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. PMID:16852469

  16. Flower power: its association with bee power and floral functional morphology in papilionate legumes

    PubMed Central

    Córdoba, Silvina A.; Cocucci, Andrea A.

    2011-01-01

    Background and Aims A test was made of the hypothesis that papilionate legume flowers filter pollinators according to their ability to exert strength to open flowers to access rewards. In addition, interactions with pollen vectors were expected to explain the structural complexity of the architecture of these flowers since operative flower strength may be determined by a combination of morphological traits which form part of an intrafloral functional module. Methods Six papilionate species were studied: Collaea argentina, Desmodium uncinatum, Galactia latisiliqua, Lathyrus odoratus, Spartium junceum and Tipuana tipu. Measurements were made of the strength needed to open keels and the strength that pollinators were capable of exerting. Morphological traits of all petals were also measured to determine which of them could be either mutually correlated or correlated with operative strength and moment of strength and participated in a functional module. Key Results It was observed that pollinators were capable in all cases of exerting forces higher and often several times higher than that needed to access floral rewards, and no association could be detected between floral operative strength and strength exerted by the corresponding pollinators. On the other hand, strong and significant correlations were found among morphometric traits and, of these, with operative strength and moment. This was particularly evident among traits of the keel and the wings, presumably involved in the functioning of the floral moveable mechanism. Conclusions Though visitors are often many times stronger than the operative strength of the flowers they pollinate, exceptionally weak bees such as Apis mellifera cannot open the strongest flowers. On the other hand, strong correlations among certain petal morphometric traits (particularly between the keel and wings) give support to the idea that an intrafloral module is associated with the functioning of the mechanism of these legume flowers. In

  17. Measurements of the betatron functions and phases in RHIC

    SciTech Connect

    Trbojevic, D.; Kewisch, J.; Peggs, S.; Satogata, T.; Tepikian, S.; Goddere, G.

    1998-08-01

    The Relativistic Heavy Ion Collider (RHIC) consists of two rings with six fold symmetry. The six interaction regions (IR)s are connected with twelve FODO cells. RHIC quadrupoles in the interaction regions have independent tuning capability. The betatron functions will be measured by a three methods. First, tunable IR quadrupoles will be adjusted to measure betatron functions at those locations through the change in tune. Second, sinusoidal coherent dipole oscillations will be used to measure the betatron phases and functions (as performed in LEP). Third, a correction dipole kick technique will be used (as at Fermilab). special attention will be given to the betatron squeeze procedure by which the two large experiments PHENIX and STAR will achieve minimum betatron functions between 1 and 2 m.

  18. 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.

  19. Caudal vertebral body articular surface morphology correlates with functional tail use in anthropoid primates.

    PubMed

    Deane, Andrew S; Russo, Gabrielle A; Muchlinski, Magdalena N; Organ, Jason M

    2014-11-01

    Prehensile tails, capable of suspending the entire body weight of an animal, have evolved in parallel in New World monkeys (Platyrrhini): once in the Atelinae (Alouatta, Ateles, Brachyteles, Lagothrix), and once in the Cebinae (Cebus, Sapajus). Structurally, the prehensile tails of atelines and cebines share morphological features that distinguish them from nonprehensile tails, including longer proximal tail regions, well-developed hemal processes, robust caudal vertebrae resistant to higher torsional and bending stresses, and caudal musculature capable of producing higher contractile forces. The functional significance of shape variation in the articular surfaces of caudal vertebral bodies, however, is relatively less well understood. Given that tail use differs considerably among prehensile and nonprehensile anthropoids, it is reasonable to predict that caudal vertebral body articular surface area and shape will respond to use-specific patterns of mechanical loading. We examine the potential for intervertebral articular surface contour curvature and relative surface area to discriminate between prehensile-tailed and nonprehensile-tailed platyrrhines and cercopithecoids. The proximal and distal intervertebral articular surfaces of the first (Ca1), transitional and longest caudal vertebrae were examined for individuals representing 10 anthropoid taxa with differential patterns of tail-use. Study results reveal significant morphological differences consistent with the functional demands of unique patterns of tail use for all vertebral elements sampled. Prehensile-tailed platyrrhines that more frequently use their tails in suspension (atelines) had significantly larger and more convex intervertebral articular surfaces than all nonprehensile-tailed anthropoids examined here, although the intervertebral articular surface contour curvatures of large, terrestrial cercopithecoids (i.e., Papio sp.) converge on the ateline condition. Prehensile-tailed platyrrhines that more

  20. 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.

  1. Human neural progenitors express functional lysophospholipid receptors that regulate cell growth and morphology

    PubMed Central

    Hurst, Jillian H; Mumaw, Jennifer; Machacek, David W; Sturkie, Carla; Callihan, Phillip; Stice, Steve L; Hooks, Shelley B

    2008-01-01

    Background Lysophospholipids regulate the morphology and growth of neurons, neural cell lines, and neural progenitors. A stable human neural progenitor cell line is not currently available in which to study the role of lysophospholipids in human neural development. We recently established a stable, adherent human embryonic stem cell-derived neuroepithelial (hES-NEP) cell line which recapitulates morphological and phenotypic features of neural progenitor cells isolated from fetal tissue. The goal of this study was to determine if hES-NEP cells express functional lysophospholipid receptors, and if activation of these receptors mediates cellular responses critical for neural development. Results Our results demonstrate that Lysophosphatidic Acid (LPA) and Sphingosine-1-phosphate (S1P) receptors are functionally expressed in hES-NEP cells and are coupled to multiple cellular signaling pathways. We have shown that transcript levels for S1P1 receptor increased significantly in the transition from embryonic stem cell to hES-NEP. hES-NEP cells express LPA and S1P receptors coupled to Gi/o G-proteins that inhibit adenylyl cyclase and to Gq-like phospholipase C activity. LPA and S1P also induce p44/42 ERK MAP kinase phosphorylation in these cells and stimulate cell proliferation via Gi/o coupled receptors in an Epidermal Growth Factor Receptor (EGFR)- and ERK-dependent pathway. In contrast, LPA and S1P stimulate transient cell rounding and aggregation that is independent of EGFR and ERK, but dependent on the Rho effector p160 ROCK. Conclusion Thus, lysophospholipids regulate neural progenitor growth and morphology through distinct mechanisms. These findings establish human ES cell-derived NEP cells as a model system for studying the role of lysophospholipids in neural progenitors. PMID:19077254

  2. Adapted to Roar: Functional Morphology of Tiger and Lion Vocal Folds

    PubMed Central

    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. PMID:22073246

  3. Importance of tissue morphology relative to patient reports of symptoms and functional limitations resulting from median nerve pathology.

    PubMed

    Roll, Shawn C; 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

  4. 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.

  5. 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. PMID:24290784

  6. 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.

  7. Role of laminin in maintenance of type II pneumocyte morphology and function

    SciTech Connect

    Rannels, S.R.; Yarnell, J.A.; Fisher, C.S.; Fabisiak, J.P.; Rannels, D.E. )

    1987-12-01

    Loss of differentiated function by type II pneumocytes plated on plastic surfaces was demonstrated by decreased lamellar body content, increased cellular protein, and rapid cellular flattening, changes that were retarded modestly by plating cells on laminin-coated surfaces. Laminin surfaces also inhibited ({sup 3}H)thymidine (THM) incorporation into cellular DNA by 40% compared with plastic at 40 h, but did not alter an additional mitogenic effect of rat serum over fetal calf serum. In contrast, cells plated on the laminin-rich basement membrane-like gel formed from an extract of EHS mouse sarcoma, matrix gel (MG), maintained a high content of intracellular lipids in lamellar inclusions and retained a rounded morphology for at least 3 days. MG markedly inhibited THM incorporation and morphological changes when cells were cultured on this surface of when MG was formed over cells initially plated on plastic for various intervals. The importance of the laminin component of MG was demonstrated when these surfaces were pretreated with a highly specific antilaminin serum. Type II cells commenced flattening on the treated MG surface, and THM incorporation increased with the same time course as did control cells on plastic. The data suggest that short-term culture and study of differentiated type II pneumocytes may require a laminin-rich substratum. THM incorporation into type II cell DNA provides an important early and sensitive index of cell-basement membrane interaction and subsequent maintenance of function.

  8. 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.

  9. 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.

  10. Functionally and morphologically distinct populations of extracellular vesicles produced by human neutrophilic granulocytes.

    PubMed

    Lőrincz, Ákos M; Schütte, Maria; Timár, Csaba I; Veres, Daniel S; Kittel, Ágnes; McLeish, Kenneth R; Merchant, Michael L; Ligeti, Erzsébet

    2015-10-01

    EVs in the microvesicle size range released during spontaneous death of human neutrophils were characterized and their properties compared with previously described EVs with antibacterial effect (aEVs, generated on specific activation) or produced spontaneously (sEVs). The 3 vesicle populations overlapped in size and in part of the constituent proteins were stained with annexin V and were impermeable to PI. However, none of them produced superoxide. In contrast, remarkable differences were observed in the morphology, abundance of proteins, and antibacterial function. EVs formed spontaneously in 30 min (sEVs) were more similar to EVs released during spontaneous death in 1-3 d than to EVs formed in 30 min on stimulation of opsonin receptors (aEVs). Spontaneously generated EVs had no antibacterial effect despite their large number and protein content. We hypothesized 2 parallel mechanisms: one that proceeds spontaneously and produces EVs without antibacterial effect and another process that is triggered by opsonin receptors and results in differential sorting of proteins into EVs with antibacterial capacity. Our results call attention to the functional and morphologic heterogeneity within the microvesicle/ectosome fraction of EVs.

  11. Correlation between morphology and function of the upper lip: a longitudinal evaluation.

    PubMed

    Ambrosio, Aldrieli Regina; Trevilatto, Paula Cristina; Sakima, Tatsuko; Ignácio, Sérgio Aparecido; Shimizu, Roberto Hideo

    2009-06-01

    In order to evaluate the relationship between the morphology of the upper lip and muscle activity in a sample of 38 subjects (17 males and 21 females) with Angle Class II division 1 malocclusions, cephalometric and electromyographic analyses were conducted. The sample was subdivided into either predominantly nose or mouth breathers. The individuals were evaluated at two different periods, with a 2 year interval. At the first observation, the subjects were 11 years to 14 years 11 months of age and at the second observation, 13 years 4 months to 16 years 6 months of age. Height and thickness of the upper lip were measured on lateral cephalograms with the aid of a digital pachymeter. For each individual, electromyographic records were obtained of the orbicularis oris superior muscle at rest and in a series of 12 movements. The electromyographic data were normalized as a function of amplitude, for achievement of the percentage value of each movement. Pearson and Spearman correlation tests were applied. The results showed some correlation between morphology and muscle function (at a confidence level of 95 per cent). However, as the values of the correlation coefficient (r) were too low to establish associations between variables, it was concluded that the dimensions of the upper lip are not correlated with muscle activity.

  12. AFM combines functional and morphological analysis of peripheral myelinated and demyelinated nerve fibers.

    PubMed

    Heredia, Alejandro; Bui, Chin Chu; Suter, Ueli; Young, Peter; Schäffer, Tilman E

    2007-10-01

    Demyelination of the myelinated peripheral or central axon is a common pathophysiological step in the clinical manifestation of several human diseases of the peripheral and the central nervous system such as the majority of Charcot-Marie-Tooth syndromes and multiple sclerosis, respectively. The structural degradation of the axon insulating myelin sheath has profound consequences for ionic conduction and nerve function in general, but also affects the micromechanical properties of the nerve fiber. We have for the first time investigated mechanical properties of rehydrated, isolated peripheral nerve fibers from mouse using atomic force microscopy (AFM). We have generated quantitative maps of elastic modulus along myelinated and demyelinated axons, together with quantitative maps of axon topography. This study shows that AFM can combine functional and morphological analysis of neurological tissue at the level of single nerve fibers.

  13. Influence of Chemical Treatment on the Morphology and Functionalization of Carbon Nanotubes.

    PubMed

    Araujo, Rafael; Marques, Maria F V; Jonas, Renato; Grafova, Iryna; Grafov, Andriy

    2016-01-01

    Multi-walled carbon nanotubes (MWCNTs) were functionalized by different oxidative treatments to insert polar groups on their surface. The treatments included sulfuric/nitric acid mixture, 6 M nitric acid solution, concentrated hydrochloric acid, sulfuric/potassium permanganate solution, and alkaline solution. The procedures succeeded in eliminating catalyst residues remaining from the MWCNT synthesis. Physical treatment by sonication was used to modify the intertubular distances and to reduce the average particle size. The materials obtained were characterized by X-ray diffraction and their morphology was studied by TEM. Particle size was analyzed by dynamic light scattering. FTIR spectroscopy was used to confirm the presence of functional groups and thermo-gravimetry (TGA) was employed to estimate the oxidation degree attained. The results confirmed polar group insertion on the surface of treated carbon nanotubes. Oxidation with 6 M nitric acid followed by sonication in xylene was found to be the most effective treatment. PMID:27398582

  14. 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. PMID:24296436

  15. 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.

  16. 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.

  17. Functional-cranial approach to the influence of economic strategy on skull morphology.

    PubMed

    González-José, Rolando; Ramírez-Rozzi, Fernando; Sardi, Marina; Martínez-Abadías, Neus; Hernández, Miquel; Pucciarelli, Hector M

    2005-12-01

    Environmental factors are assumed to play an important role in the shaping of craniofacial morphology. Here we propose a statistical approach which can be of utility in estimating the magnitude and localization of a particular nongenetic factor upon the specific functional components of the skull. Our analysis is a combination of previous attempts of apportionment of variance and the application of craniofunctional theory. The effect of subsistence strategy on craniofacial functional components was studied on 18 populations of hunter-gatherers and farmers from South America. Results demonstrate that the environmental factors studied likely influenced the masticatory component's size and shape. Even when this effect is not large enough to clearly differentiate among subsistence strategies (since whole craniofacial variation among populations remains greater), the method used here provides interesting clues to localize plastic or adaptive responses to external stimuli.

  18. 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

  19. Morphological and functional characterization of leech circulating blood cells: role in immunity and neural repair.

    PubMed

    Boidin-Wichlacz, Céline; Vergote, David; Slomianny, Christian; Jouy, Nathalie; Salzet, Michel; Tasiemski, Aurélie

    2012-05-01

    Unlike most invertebrates, annelids possess a closed vascular system distinct from the coelomic liquid. The morphology and the function of leech blood cells are reported here. We have demonstrated the presence of a unique cell type which participates in various immune processes. In contrast to the mammalian spinal cord, the leech CNS is able to regenerate and restore function after injury. The close contact of the blood with the nerve cord also led us to explore the participation of blood in neural repair. Our data evidenced that, in addition to exerting peripheral immune functions, leech blood optimizes CNS neural repair through the release of neurotrophic substances. Circulating blood cells also appeared able to infiltrate the injured CNS where, in conjunction with microglia, they limit the formation of a scar. In mammals, CNS injury leads to the generation of a glial scar that blocks the mechanism of regeneration by preventing axonal regrowth. The results presented here constitute the first description of neuroimmune functions of invertebrate blood cells. Understanding the basic function of the peripheral circulating cells and their interactions with lesioned CNS in the leech would allow us to acquire insights into the complexity of the neuroimmune response of the injured mammalian brain. PMID:22159559

  20. 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

  1. 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. PMID:16594703

  2. Closed fringe demodulation using phase decomposition by Fourier basis functions.

    PubMed

    Kulkarni, Rishikesh; Rastogi, Pramod

    2016-06-01

    We report a new technique for the demodulation of a closed fringe pattern by representing the phase as a weighted linear combination of a certain number of linearly independent Fourier basis functions in a given row/column at a time. A state space model is developed with the weights of the basis functions as the elements of the state vector. The iterative extended Kalman filter is effectively utilized for the robust estimation of the weights. A coarse estimate of the fringe density based on the fringe frequency map is used to determine the initial row/column to start with and subsequently the optimal number of basis functions. The performance of the proposed method is evaluated with several noisy fringe patterns. Experimental results are also reported to support the practical applicability of the proposed method. PMID:27409439

  3. Nonclassicality indicator for the real phase-space distribution functions

    SciTech Connect

    Sadeghi, Parvin; Khademi, Siamak; Nasiri, Sadollah

    2010-07-15

    Benedict et al. and Kenfack et al. advocated nonclassicality indicators based on the measurement of negativity of the Wigner distribution functions. These indicators have some applications in quantum mechanics and quantum optics. In this paper we define a nonclassicality indicator in terms of the interference in phase space, which is applicable to some real distribution functions including those of Wigner. As a special case one may reproduce the previous results using our indicator for the Wigner distribution functions. This indicator is examined for cases of the Schroedinger cat state and the thermal states and the results are compared with those obtained by previous methods. It seems that the physical behavior of nonclassicality indicators originates in the uncertainty principle. This is shown by an onto correspondence between these indicators and the uncertainty principle.

  4. Studying the morphology of the magnetic C4 phase in the 122 superconductors

    NASA Astrophysics Data System (ADS)

    Taddei, Keith; Allred, Jared; Bugaris, Daniel; Krogstad, Matthew; Lapidus, Saul; Stadel, Ryan; Chung, Duck; Claus, Helmut; Kanatzidis, Mercouri; Brown, Dennis; Rosenkranz, Stephan; Osborn, Raymond; Chmaissem, Omar

    The iron based superconductors continue to prove an exciting system for the study of superconductivity: the recent discovery of a reentrant tetragonal phase with SDW magnetic ordering has opened new avenues to study the competition between microscopically coexistent superconductivity and magnetism. This intriguing new phase is not only an exceedingly rare example of a magnetic structure with two ordering vectors, and consequently a confirmation of itinerate magnetism, but has also allowed for the determination of spin fluctuations as the driving mechanism behind the phase evolution in these materials. Evidence has been mounting of the universality of C4 in the hole doped iron pnictides providing a useful playground for the comparison of how this phase behaves as it is stabilized out of different parent compounds and through different dopant atoms. Here all members of the hole doped family which show the C4 phase will be compared and the parameters which appear to tune the phase's extent in temperature and phase space will be discussed.

  5. 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. PMID:25247136

  6. 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

  7. 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.

  8. 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.

  9. Adiabatic continuity, wave-function overlap, and topological phase transitions

    NASA Astrophysics Data System (ADS)

    Gu, Jiahua; Sun, Kai

    2016-09-01

    In this paper, we study the relation between wave-function overlap and adiabatic continuity in gapped quantum systems. We show that for two band insulators, a scalar function can be defined in the momentum space, which characterizes the wave-function overlap between Bloch states in the two insulators. If this overlap is nonzero for all momentum points in the Brillouin zone, these two insulators are adiabatically connected, i.e., we can deform one insulator into the other smoothly without closing the band gap. In addition, we further prove that this adiabatic path preserves all the symmetries of the insulators. The existence of such an adiabatic path implies that two insulators with nonzero wave-function overlap belong to the same topological phase. This relation, between adiabatic continuity and wave-function overlap, can be further generalized to correlated systems. The generalized relation cannot be applied to study generic many-body systems in the thermodynamic limit, because of the orthogonality catastrophe. However, for certain interacting systems (e.g., quantum Hall systems), the quantum wave-function overlap can be utilized to distinguish different quantum states. Experimental implications are also discussed.

  10. 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

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

    PubMed

    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.

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

    PubMed

    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. (Thermodynamics, kinetics, and interfare morphologies of phase formation reactions between metals and gallium arsenide: Bulk vs thin-film studies)

    SciTech Connect

    Chang, Y.A.

    1989-01-01

    During the past two years or so, we have been carrying out the following studies: (i) investigation of the thermodynamic stabilities of selected GaAs/M couples by determining the Ga-M-As phase diagrams at one temperature in the composition region of importance to the metallization of GaAs and (ii) determination of the kinetics and morphologies of reactions between GaAs and M for both bulk and thin-film cases. The metallic elements which have been studied are Pd, Pt, Ir, Rh, Nb, Co and Ni. In the following, we will summarize briefly our accomplishments. 27 refs.

  14. 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.

  15. Solvothermal synthesis of Fe7C3 and Fe3C nanostructures with phase and morphology control

    NASA Astrophysics Data System (ADS)

    Williams, Brent; Clifford, Dustin; El-Gendy, Ahmed A.; Carpenter, Everett E.

    2016-07-01

    A phase transition, from orthorhombic Fe3C to hexagonal Fe7C3, was observed using a wet synthesis mediated by hexadecyltrimethylammonium chloride (CTAC). In this study, CTAC has been shown to control carbide phase, morphology, and size of the iron carbide nanostructures. Fe7C3 hexagonal prisms were formed with an average diameter of 960 nm, the thickness of 150 nm, and Fe3C nanostructures with an approximate size of 50 nm. Magnetic studies show ferromagnetic behavior with Ms of 126 emu/g, and Hc of 170 Oe with respect to Fe7C3 and 95 emu/g and 590 Oe with respect to Fe3C. The thermal studies using high temperature x-ray diffraction show stability of Fe7C3 up to 500 °C. Upon slow cooling, the Fe7C3 phase is recovered with an intermediate oxide phase occurring around 300 °C. This study has demonstrated a simple route in synthesizing iron carbides for an in depth magnetic study and crystal phase transition study of Fe7C3 at elevated temperatures.

  16. Many Paths to a Common Destination: Morphological Differentiation of a Functionally Convergent Visual Signal.

    PubMed

    Hagman, Mattias; Ord, Terry J

    2016-09-01

    Understanding the interacting outcomes of selection and historical contingency in shaping adaptive evolution remains a challenge in evolutionary biology. While selection can produce convergent outcomes when species occupy similar environments, the unique history of each species can also influence evolutionary trajectories and result in different phenotypic end points. The question is to what extent historical contingency places species on different adaptive pathways and, in turn, the extent to which we can predict evolutionary outcomes. Among lizards there are several distantly related genera that have independently evolved an elaborate extendible dewlap for territorial communication. We conducted a detailed morphological study and employed new phylogenetic comparative methods to investigate the evolution of the underlying hyoid that powers the extension of the dewlap. This analysis showed that there appear to have been multiple phenotypic pathways for evolving a functionally convergent dewlap. The biomechanical complexity that underlies this morphological structure implies that adaptation should have been constrained to a narrow phenotypic pathway. However, multiple adaptive solutions have been possible in apparent response to a common selection pressure. Thus, the phenotypic outcome that subsequently evolved in different genera seems to have been contingent on the history of the group in question. This blurs the distinction between convergent and historically contingent adaptation and suggests that adaptive phenotypic diversity can evolve without the need for divergent natural selection. PMID:27501088

  17. Local morphology predicts functional organization of experienced value signals in the human orbitofrontal cortex.

    PubMed

    Li, Yansong; Sescousse, Guillaume; Amiez, Céline; Dreher, Jean-Claude

    2015-01-28

    Experienced value representations within the human orbitofrontal cortex (OFC) are thought to be organized through an antero-posterior gradient corresponding to secondary versus primary rewards. Whether this gradient depends upon specific morphological features within this region, which displays considerable intersubject variability, remains unknown. To test the existence of such relationships, we performed a subject-by-subject analysis of fMRI data taking into account the local morphology of each individual. We tested 38 subjects engaged in a simple incentive delay task manipulating both monetary and visual erotic rewards, focusing on reward outcome (experienced value signal). The results showed reliable and dissociable primary (erotic) and secondary (monetary) experienced value signals at specific OFC sulci locations. More specifically, experienced value signal induced by monetary reward outcome was systematically located in the rostral portion of the medial orbital sulcus. Experienced value signal related to erotic reward outcome was located more posteriorly, that is, at the intersection between the caudal portion of the medial orbital sulcus and transverse orbital sulcus. Thus, the localizations of distinct experienced value signals can be predicted from the organization of the human orbitofrontal sulci. This study provides insights into the anatomo-functional parcellation of the anteroposterior OFC gradient observed for secondary versus primary rewards because there is a direct relationship between value signals at the time of reward outcome and unique OFC sulci locations. PMID:25632140

  18. In silico evolution of functional morphology: A test on bone tissue biomechanics.

    PubMed

    de Margerie, Emmanuel; Tafforeau, Paul; Rakotomanana, Lalaonirina

    2006-10-22

    Evolutionary algorithms (EAs) use Darwinian principles--selection among random variation and heredity--to find solutions to complex problems. Mostly used in engineering, EAs gain growing interest in ecology and genetics. Here, we assess their usefulness in functional morphology, introducing finite element modelling (FEM) as a simulated mechanical environment for evaluating the 'fitness' of randomly varying structures. We used this method to identify biomechanical adaptations in bone tissue, a long-lasting problem in skeletal morphology. The algorithm started with a bone tissue model containing randomly distributed vascular spaces. The EA randomly mutated the distribution of vascular spaces, and selected the new structure if its mechanical resistance was increased. After some thousands of generations, organized phenotypes emerged, containing vascular canals and sinuses, mimicking real bone tissue organizations. This supported the hypothesis that natural bone microstructures can result from biomechanical adaptation. Despite its limited faithfulness to reality, we discuss the ability of the EA+FEM method to assess adaptation in a dynamic evolutionary framework, which is not possible in the real world because of the generation times of macro-organisms. We also point out the interesting potential of EAs to simulate not only adaptation, but also concurrent evolutionary phenomenons such as historical contingency.

  19. Gestational protein restriction induces alterations in placental morphology and mitochondrial function in rats during late pregnancy.

    PubMed

    Rebelato, Hércules Jonas; Esquisatto, Marcelo Augusto Marreto; Moraes, Camila; Amaral, Maria Esmeria Corezola; Catisti, Rosana

    2013-12-01

    The placenta acts a regulator of nutrient composition and supply from mother to fetus and is the source of hormonal signals that affect maternal and fetal metabolism. Thus, appropriate development of the placenta is crucial for normal fetal development. We investigated the effect of gestational protein restriction (GPR) on placental morphology and mitochondrial function on day 19 of gestation. Pregnant dams were divided into two groups: normal (NP 17 % casein) or low-protein diet (LP 6 % casein). The placentas were processed for biochemical, histomorphometric and ultrastructural analysis. The integrity of rat placental mitochondria (RPM) isolated by conventional differential centrifugation was measured by oxygen uptake (Clark-type electrode). LP animals presented an increase in adipose tissue and triacylglycerol and a decrease in serum insulin levels. No alterations were observed in body, liver, fetus, or placenta weight. There was also no change in serum glucose, total protein, or lipid content. Gestational protein restriction had tissue-specific respiratory effects, with the observation of a small change in liver respiration (~13 %) and considerable respiratory inhibition in placenta samples (~37 %). The higher oxygen uptake by RPM in the LP groups suggests uncoupling between respiration and oxidative phosphorylation. In addition, ultrastructural analysis of junctional zone giant cells from LP placenta showed a disorganized cytoplasm, with loss of integrity of most organelles and intense vacuolization. The present results led us to hypothesize that GPR alters placental structure and morphology, induces sensitivity to insulin, mitochondrial abnormalities and suggests premature aging of the placenta. Further studies are needed to test this hypothesis.

  20. Resin gathering in neotropical resin bugs (Insecta: Hemiptera: Reduviidae): functional and comparative morphology.

    PubMed

    Forero, Dimitri; Choe, Dong-Hwan; Weirauch, Christiane

    2011-02-01

    Apiomerini (Reduviidae: Harpactorinae) collect plant resins with their forelegs and use these sticky substances for prey capture or maternal care. These behaviors have not been described in detail and morphological structures involved in resin gathering, transfer, and storage remain virtually undocumented. We here describe these behaviors in Apiomerus flaviventris and document the involved structures. To place them in a comparative context, we describe and document leg and abdominal structures in 14 additional species of Apiomerini that represent all but one of the 12 recent genera in the tribe. Based on these morphological data in combination with the behavioral observations on A. flaviventris, we infer behavioral and functional hypotheses for the remaining genera within the tribe Apiomerini. Setal abdominal patches for resin storage are associated with maternal care so far only documented for species of Apiomerus. Based on the occurrence of these patches in several other genera, we propose that maternal care is widespread within the tribe. Ventral abdominal glands are widespread within female Apiomerini. We propose that their products may prevent hardening of stored resins thus providing long-term supply for egg coating. Judging from the diverse setal types and arrangements on the front legs, we predict six different behavioral patterns of resin gathering within the tribe.

  1. 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.

  2. Study of the functional morphology of mouthparts of parasitic isopods of marine fishes

    PubMed Central

    Rameshkumar, Ganapathy; Ravichandran, Samuthirapandian; Allayie, Sartaj Ahmad

    2013-01-01

    Objective To carry out a comparative study of the mouthparts and the diet of eight isopod fish parasites. Methods A description of the mouthparts, together with their diet nature, was derived both by direct observation and an interpretation of their structure. The three-dimensional study of the mouthparts of the isopod parasites was done to reveal their morphology. Results Observations revealed that these species are wholly carnivorous. Result shows how they are adapted for tearing and bolting fish food material. The mouthparts consist of a labrum, paragnaths, paired mandibles, maxillules, maxillae and maxillipeds. The labrum and the paragnaths are the least developed but peculiarly the mandibles are asymmetrical, large, stout and highly modified. The analysis of gut contents indicated that Cymothoa indica and Joryma brachysoma diet consisted of 90% to 95% of animal blood. The diet of Mothocya renardi, Ryukyua circularis and Joryma hilsae were mainly composed of mucus (80%-90%). The stomach contents of Nerocila phaeopleura and Nerocila sundaica, were dominated by body muscles (75%-83%). Conclusions The possible functions of the mouthparts, especially in feeding are discussed in light of their structure. The morphology of the mouthparts of the isopod parasites are heavily modified with their feeding behavior.

  3. 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.

  4. Morphology and Rheology of the Phase-separating Polybutadiene /Polyisoprene Blend under Small Amplitude Oscillatory Shear

    NASA Astrophysics Data System (ADS)

    Dong, Xia; Zou, Fasheng; Wang, Dujin; Han, Charles C.

    2013-03-01

    We are mainly focusing on the late stage of phase separation process where the two phases have reach their equilibrium compositions and the droplet dimension or interface area is the key factor in influencing the dynamic moduli. Two kinds of phase-separating structure evolutions of the PB/LPI blend have been investigated. For the near-critical and symmetric blend LPI50, the co-continuous phase-separating structures are observed and lead to a power law behavior of the dynamic storage modulus at low frequencies. With the growth of the co-continuous structure, the storage modulus at low frequency decreases dramatically. For the off-critical and asymmetric blend LPI70, the droplet/matrix two-phase structures appear and result in a rather complex elastic behavior at the mediate and low frequency region. It is observed that with the droplet size increases, the storage modulus at the mediate frequencies generally decreases while the storage modulus at the low frequencies usually increases. Besides, the platform and terminal moduli at a given frequency can be scalable with the phase separation time and the characteristic relaxation time and domain size of the droplets can be obtained by rheology. NSFC No.50930002 and No.51173195.

  5. Holographic partition functions and phases for higher genus Riemann surfaces

    NASA Astrophysics Data System (ADS)

    Maxfield, Henry; Ross, Simon F.; Way, Benson

    2016-06-01

    We describe a numerical method to compute the action of Euclidean saddle points for the partition function of a two-dimensional holographic CFT on a Riemann surface of arbitrary genus, with constant curvature metric. We explicitly evaluate the action for the saddles for genus two and map out the phase structure of dominant bulk saddles in a two-dimensional subspace of the moduli space. We discuss spontaneous breaking of discrete symmetries, and show that the handlebody bulk saddles always dominate over certain non-handlebody solutions.

  6. 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.

  7. Hypoxia signaling controls postnatal changes in cardiac mitochondrial morphology and function.

    PubMed

    Neary, Marianne T; Ng, Keat-Eng; Ludtmann, Marthe H R; Hall, Andrew R; Piotrowska, Izabela; Ong, Sang-Bing; Hausenloy, Derek J; Mohun, Timothy J; Abramov, Andrey Y; Breckenridge, Ross A

    2014-09-01

    Fetal cardiomyocyte adaptation to low levels of oxygen in utero is incompletely understood, and is of interest as hypoxia tolerance is lost after birth, leading to vulnerability of adult cardiomyocytes. It is known that cardiac mitochondrial morphology, number and function change significantly following birth, although the underlying molecular mechanisms and physiological stimuli are undefined. Here we show that the decrease in cardiomyocyte HIF-signaling in cardiomyocytes immediately after birth acts as a physiological switch driving mitochondrial fusion and increased postnatal mitochondrial biogenesis. We also investigated mechanisms of ATP generation in embryonic cardiac mitochondria. We found that embryonic cardiac cardiomyocytes rely on both glycolysis and the tricarboxylic acid cycle to generate ATP, and that the balance between these two metabolic pathways in the heart is controlled around birth by the reduction in HIF signaling. We therefore propose that the increase in ambient oxygen encountered by the neonate at birth acts as a key physiological stimulus to cardiac mitochondrial adaptation.

  8. 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.

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

    PubMed

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

    2013-12-01

    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.

  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. Recent advances in the morphological and functional heterogeneity of the biliary epithelium

    PubMed Central

    Han, Yuyan; Glaser, Shannon; Meng, Fanyin; Francis, Heather; Marzioni, Marco; McDaniel, Kelly; Alvaro, Domenico; Venter, Julie; Carpino, Guido; Onori, Paolo; Gaudio, Eugenio; Alpini, Gianfranco; Franchitto, Antonio

    2014-01-01

    This review focuses on the recent advances related to the heterogeneity of different-sized bile ducts with regard to the morphological and phenotypical characteristics, and the differential secretory, apoptotic and proliferative responses of small and large cholangiocytes to gastrointestinal hormones/peptides, neuropeptides and toxins. We describe several in vivo and in vitro models used for evaluating biliary heterogeneity. Subsequently, we discuss the heterogeneous proliferative and apoptotic responses of small and large cholangiocytes to liver injury and the mechanisms regulating the differentiation of small into large (more differentiated) cholangiocytes. Following a discussion on the heterogeneity of stem/progenitor cells in the biliary epithelium, we outline the heterogeneity of bile ducts in human cholangiopathies. After a summary section, we discuss the future perspectives that will further advance the field of the functional heterogeneity of the biliary epithelium. PMID:23856906

  12. 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

  13. 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

  14. 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.

  15. 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

  16. 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. PMID:21630322

  17. 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

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

    PubMed Central

    Amazon, Jonathan J.; Feigenson, Gerald W.

    2015-01-01

    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. PMID:25353504

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

    PubMed

    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. PMID:25353504

  20. 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.

  1. 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

  2. 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.

  3. 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

  4. Functional Properties and Morphological Characters of Soluble Dietary Fibers in Different Edible Parts of Angelica Keiskei.

    PubMed

    Xie, Fan; Wang, Yuqiang; Wu, Jinhong; Wang, Zhengwu

    2016-09-01

    This study comparatively investigated the functional properties, chemical compositions, and morphological characters of soluble dietary fibers (SDFs) from the root, stem, and leaf of Angelica keiskei. The SDFs showed relevant functional properties, with the root SDF (RSDF) exhibiting the highest water-holding capacity (22.6 g/g), oil-holding capacity (6.29 mL/g), swelling capacity (36.6 mL/g), emulsion stability, and fat adsorption (5.66 g/g). Stem SDF (SSDF) gave the highest foam stability, toxic ions adsorption (Pb: 1.12 mg/g; As: 3.22 mg/g), and bile acid salts adsorption (sodium cholate: 85.6 mg/g; sodium glycocholate: 93.1 mg/g; sodium taurocholate: 125.7 mg/g). RSDF and SSDF presented similar monosaccharide compositions, thermal property, chemical bonds and groups, and irregular, rough, and porous surfaces. It can be concluded that the obtained SDFs, especially for RSDF and SSDF, can be used in the food industry as fiber-rich functional ingredients.

  5. 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.

  6. Functional Properties and Morphological Characters of Soluble Dietary Fibers in Different Edible Parts of Angelica Keiskei.

    PubMed

    Xie, Fan; Wang, Yuqiang; Wu, Jinhong; Wang, Zhengwu

    2016-09-01

    This study comparatively investigated the functional properties, chemical compositions, and morphological characters of soluble dietary fibers (SDFs) from the root, stem, and leaf of Angelica keiskei. The SDFs showed relevant functional properties, with the root SDF (RSDF) exhibiting the highest water-holding capacity (22.6 g/g), oil-holding capacity (6.29 mL/g), swelling capacity (36.6 mL/g), emulsion stability, and fat adsorption (5.66 g/g). Stem SDF (SSDF) gave the highest foam stability, toxic ions adsorption (Pb: 1.12 mg/g; As: 3.22 mg/g), and bile acid salts adsorption (sodium cholate: 85.6 mg/g; sodium glycocholate: 93.1 mg/g; sodium taurocholate: 125.7 mg/g). RSDF and SSDF presented similar monosaccharide compositions, thermal property, chemical bonds and groups, and irregular, rough, and porous surfaces. It can be concluded that the obtained SDFs, especially for RSDF and SSDF, can be used in the food industry as fiber-rich functional ingredients. PMID:27481763

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

    PubMed

    Prokop, Jakub; Pecharová, Martina; Ren, Dong

    2016-06-20

    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.

  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

    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. 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.

  11. 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. PMID:18277078

  12. 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.

  13. Deformation across length scales in polyolefines: effect of the chain microstructure on the polymorphism, phase transitions and morphological changes

    NASA Astrophysics Data System (ADS)

    Auriemma, Finizia; De Rosa, Claudio; di Girolamo, Rocco; Malafronte, Anna; Scoti, Miriam

    The transformations related to phase changes of the crystals, and at lamellar length scales by effect of tensile deformation are studied in the case of some isotactic polypropylene samples having high molecular mass, polydispersity index ~2, and stereodefects at different concentrations and with a uniform distribution, The stress induced transformations are followed in real time during stretching through wide and small angle X-ray scattering measurements. The data analysis evidences that during the transformations of the spherulitic into the fibrillar morphology, stress-induced phase transitions occurring during plastic deformation are regulated by the same factors that govern the textural and morphological changes, that is the ability of the entangled amorphous chains to transmit the stress and the intrinsic stability of the lamellar crystals. Since the relative stability of the different polymorphic forms involved in the structural transformations and the intrinsic flexibility of the chains depend on the stereoregularity, precise correlations between the stereoregularity of the chains, and the deformation behavior are outlined, paving the way for understanding the material properties at molecular level.

  14. Phase formation and morphological stability of ultrathin Ni-Co-Pt silicide films formed on Si(100)

    SciTech Connect

    Xu, Peng; Wu, Dongping; Kubart, Tomas; Gao, Xindong; Zhang, Shi-Li

    2014-05-15

    Ultrathin Ni, Co, and Pt films, each no more than 4 nm in thickness, as well as their various combinations are employed to investigate the competing growth of epitaxial Co{sub 1-y}Ni{sub y}Si{sub 2} films against polycrystalline Pt{sub 1-z}Ni{sub z}Si. The phase formation critically affects the morphological stability of the resulting silicide films, with the epitaxial films being superior to the polycrystalline ones. Any combination of those metals improves the morphological stability with reference to their parent individual metal silicide films. When Ni, Co, and Pt are all included, the precise initial location of Pt does little to affect the final phase formation in the silicide films and the epitaxial growth of Co{sub 1-x}Ni{sub x}Si{sub 2} films is always perturbed, in accordance to thermodynamics that shows a preferential formation of Pt{sub 1-z}Ni{sub z}Si over that of Co{sub 1-y}Ni{sub y}Si{sub 2}.

  15. 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

  16. Zero Spontaneous Curvature and Its Effects on Lamellar Phase Morphology and Vesicle Size Distributions

    SciTech Connect

    Coldren,B.; Warriner, H.; van Zanten, R.; Zasadzinski, J.

    2006-01-01

    Equimolar mixtures of dodecyltrimethylammonium chloride (DTAC) and sodium octyl sulfonate (SOSo) show a vesicle phase at >99 wt % water and a single, fluid lamellar phase for water fractions below 80 wt %. This combination is consistent with the bilayer bending elasticity {kappa}{approx}k{sub B}T and zero bilayer spontaneous curvature. Caill{acute e} line shape analysis of the small-angle X-ray scattering from the lamellar phase shows that the effective {kappa} depends on the lamellar d spacing consistent with a logarithmic renormalization of {kappa}, with {kappa}{sub 0} = (0.8 {+-} 0.1)k{sub B}T. The vesicle size distribution determined by cryogenic transmission electron microscopy is well fit by models with zero spontaneous curvature to give ({kappa} + ({kappa}/2)) = (1.7 {+-} 0.1)k{sub B}T, resulting in {kappa}= (1.8 {+-} 0.2)k{sub B}T. The positive value of {kappa} and the lack of spontaneous curvature act to eliminate the spherulite defects found in the lamellar gel phases found in other catanionic mixtures. Current theories of spontaneous bilayer curvature require an excess of one or more components on opposite sides of the bilayer; the absence of such an excess at equimolar surfactant ratios explains the zero spontaneous curvature.

  17. Controlling the growth morphology and phase segregation of Mn-doped Ga{sub 2}Se{sub 3} on Si(001).

    SciTech Connect

    Lovejoy, T. C.; Yitamben, E. N.; Heald, S. M.; Ohuchi, F. S.; Olmstead, M. A.

    2011-04-18

    The growth and phase segregation properties of the potential dilute magnetic semiconductor alloy (MnSe){sub x}(Ga{sub 2/3}Se){sub 1-x} are studied as a function of thickness, Mn concentration, postgrowth annealing, and the presence or absence of undoped Ga{sub 2}Se{sub 3} buffer and capping layers. This system is an unusual case in heteroepitaxy where two-phase MnSe{sup +}Ga{sub 2}Se{sub 3} has better lattice matching than the (MnSe){sub x}(Ga{sub 2/3}Se){sub 1-x} alloy. Despite this peculiarity, this system shows a modified form of Stranski-Krastonow growth: laminar films are observed up to a certain x-dependent critical thickness, above which islands are observed by scanning tunneling microscopy. The island morphology depends on the presence or absence of an undoped Ga{sub 2}Se{sub 3} buffer layer and postgrowth annealing. A kinetically stabilized platelet morphology is observed at the crossover point between laminar and islanded films. Based on Mn and Se K-edge extended x-ray absorption fine structure and x-ray absorption near-edge structure spectroscopy, there are two types of Mn in islanded films: Mn that remains doped in the Ga{sub 2}Se{sub 3} but oxidizes upon exposure to air, and Mn that participates in the islands, which are precipitates of the MnSe phase. Consistent with MnO or MnSe, L-edge x-ray absorption on air-exposed films suggests the Mn is in the formal +2 oxidation state. No L-edge x-ray magnetic circular dichroism signal is observed at 20 K, which may be due to surface effects or to a lack of magnetic order.

  18. 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

  19. Left ventricular morphology and diastolic function in uraemia: echocardiographic evidence of a specific cardiomyopathy.

    PubMed Central

    Facchin, L.; Vescovo, G.; Levedianos, G.; Zannini, L.; Nordio, M.; Lorenzi, S.; Caturelli, G.; Ambrosio, G. B.

    1995-01-01

    OBJECTIVE--To see whether cardiac morphological and functional abnormalities in uraemic patients are determined by high blood pressure or if they are an expression of a specific cardiomyopathy. DESIGN--Cross sectional study. SETTING--City general hospital in Italy. SUBJECTS--35 uraemic patients receiving haemodialysis (17 men, 18 women; mean age 60.3 (11.2); mean duration of dialysis 52 months) were selected from the 64 patients in Venice who were receiving dialysis; subjects with diabetes, haemochromatosis, valvar dysfunction, regional dyskinesias, and pericarditis were excluded. 19 control normotensive subjects (6 men and 13 women), matched for age. MAIN OUTCOME MEASURES--Echocardiographic measurements of left atrium, left ventricular end diastolic and end systolic volume, aortic root diameter, posterior wall and interventricular septum thickness, left ventricle mass index, and ejection fraction in controls and in patients according to whether they were normotensive (five men, eight women) or hypertensive (12 men, 10 women) on 48 hour ambulatory monitoring; left ventricular diastolic function by Doppler ultrasonography. RESULTS--Mean systolic and diastolic pressures, daytime systolic and diastolic pressures, and night time systolic and diastolic pressures were significantly higher in the hypertensive patients than in the normotensive patients. The normotensive patients had similar blood pressures to the controls. Left ventricular mass correlated significantly with the mean diastolic pressure and mean night time systolic and diastolic pressures. Parathyroid hormone concentrations were similar in the two groups of patients. Diastolic relaxation was impaired to the same degree in the two groups of patients. Parameters of diastolic function showed no relation to left ventricular mass, which was significantly higher in the hypertensive than in the normotensive patients. CONCLUSIONS--Uraemia is likely to induce specific changes in the relaxation properties of the

  20. Functional and morphological maturation of implanted neonatal cardiomyocytes as a comparator for cell therapy.

    PubMed

    Sato, Motoki; Carr, Carolyn A; Stuckey, Daniel J; Ishii, Hikaru; Kanda, Gaelle Kikonda; Terracciano, Cesare M N; Siedlecka, Urszula; Tatton, Louise; Watt, Suzanne M; Martin-Rendon, Enca; Clarke, Kieran; Harding, Sian E

    2010-07-01

    Knowledge of the rate of development of immature cardiomyocytes after implantation into a host heart is important for studies using cell therapy. To assess this functionally, we have implanted rat neonatal cardiomyocytes (NCMs) in normal and infarcted rat heart and re-isolated them for functional assessment. Maturation of implanted bone marrow stromal cells (BMSCs) was compared under similar conditions. NCMs from green fluorescent protein (GFP) transgenic rats were implanted into adult normal or infarcted rat hearts and re-isolated after 1, 2, or 4 weeks by standard enzymatic digestion. BMSCs labeled with DiI and iron oxide were implanted into rats with myocardial infarction and cells re-isolated 1, 2, 5, 6, and 16 weeks later. GFP-labeled myocytes approaching the adult morphology were detected 2 weeks after implantation of NCMs, but were significantly shorter than adult host myocytes and had reduced contractility. By 4 weeks after implantation, re-isolated GFP-labeled myocytes were close to the adult phenotype in contractile characteristics, although still significantly shorter. Infarction of the host did not alter the rate of maturation of implanted cells. After implantation of BMSCs, small numbers of functional DiI-labeled myocytes were re-isolated from 4/11 animals but were more mature than expected from the NCM studies. This adds evidence that BMSC-derived cardiomyocytes were not a result of transdifferentiation. The maturation rate of implanted NCMs represents a benchmark against which to evaluate the likely rate of formation of fully functional cardiomyocytes from implanted cells. PMID:20053126

  1. Relation between facial morphology, personality and the functions of facial make-up in women.

    PubMed

    Korichi, R; Pelle-de-Queral, D; Gazano, G; Aubert, A

    2011-08-01

    Our external appearance plays a key role in everyday life's social interactions. Hence, taking care of our appearance allows us to adjust and protect ourselves, as well as communicate emotional disposition (i.e. sympathy or aversion) and social information (i.e. values, status). However, some discrete body parts or characteristics appear to be more salient than others in contributing to global body image. For example, authors showed that facial attractiveness is one of the best predictors of overall physical attractiveness and represent one of the primary factors influencing global self-esteem. Make-up is therefore ought to play a major influence in these parameters. Moreover, in a previous study whose subject was to explain the reasons that motivate women to make-up, we showed a high implication of specific psychological traits in correlation with two make-up functions (i.e. psycho-behavioural profiles 'Seduction' and 'Camouflage'; group S and group C, respectively). The purpose of this study was to assess the possible relation between our two psycho-behavioural profiles and some morphological parameters know to be involved in facial attraction (i.e. facial asymmetry and skin visual quality). First of all, our study revealed for women from the group C a greater asymmetry of the lower face (i.e. mouth area) that could be related to a possible larger amount of negative emotional experiences. Concerning make-up behaviour, women from the group S more extensively manipulated their relative facial attractiveness, by using a large range of colours, but also through a significantly longer make-up process used to adjust their visual asymmetry and therefore increase their potential of attractiveness. On the overall, our results suggest that make-up is used differentially, according to stable psychological profiles of women, to manipulate specific visual/morphological facial features involved in attractiveness.

  2. Relation between facial morphology, personality and the functions of facial make-up in women.

    PubMed

    Korichi, R; Pelle-de-Queral, D; Gazano, G; Aubert, A

    2011-08-01

    Our external appearance plays a key role in everyday life's social interactions. Hence, taking care of our appearance allows us to adjust and protect ourselves, as well as communicate emotional disposition (i.e. sympathy or aversion) and social information (i.e. values, status). However, some discrete body parts or characteristics appear to be more salient than others in contributing to global body image. For example, authors showed that facial attractiveness is one of the best predictors of overall physical attractiveness and represent one of the primary factors influencing global self-esteem. Make-up is therefore ought to play a major influence in these parameters. Moreover, in a previous study whose subject was to explain the reasons that motivate women to make-up, we showed a high implication of specific psychological traits in correlation with two make-up functions (i.e. psycho-behavioural profiles 'Seduction' and 'Camouflage'; group S and group C, respectively). The purpose of this study was to assess the possible relation between our two psycho-behavioural profiles and some morphological parameters know to be involved in facial attraction (i.e. facial asymmetry and skin visual quality). First of all, our study revealed for women from the group C a greater asymmetry of the lower face (i.e. mouth area) that could be related to a possible larger amount of negative emotional experiences. Concerning make-up behaviour, women from the group S more extensively manipulated their relative facial attractiveness, by using a large range of colours, but also through a significantly longer make-up process used to adjust their visual asymmetry and therefore increase their potential of attractiveness. On the overall, our results suggest that make-up is used differentially, according to stable psychological profiles of women, to manipulate specific visual/morphological facial features involved in attractiveness. PMID:21284661

  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. Lehr's fields of campaniform sensilla in beetles (Coleoptera): functional morphology. I. General part and allometry.

    PubMed

    Frantsevich, Leonid; Gorb, Stanislav; Radchenko, Vladimir; Gladun, Dmytro; Polilov, Alexey

    2014-11-01

    In this first of three articles we show the construction of the articular part of the elytron, the root. The root bears a conspicuous field of campaniform sensilla. This field was studied using light and scanning electron microscopes. The diversity of shape of the field among beetles, types of orientation of elongated sensilla within the field, individual variability of their number among conspecifics are demonstrated. Elongated sensilla point to the junction of the elytron with the second axillary plate. Presumably, they monitor twist movement in this junction, which is possible if the elytron is open. The goal of the whole project is to reveal the effect of both structure and function of the hind wings and elytra on the morphology of this mechanosensory field. Our data on allometric relationships between the animal size and quantitative characteristics of the field in normally flying beetles provide an important background for further functional analysis of this sensory organ. We selected 14 series of several species belonging to the same taxon but differing in size from big to small. It is revealed that the area of the sensory field is directly proportional to the elytral area, whereas the number of sensilla is proportional to the square root of the elytral area. Despite the great range in the elytral area (1500 times) in series of selected species the area of an external pit or cap of a single sensillum varies only 25-fold. The density of sensilla per unit area of the sensory field increases with decrease of the elytral area.

  5. Recent advances on the functional and evolutionary morphology of the amniote respiratory apparatus.

    PubMed

    Lambertz, Markus

    2016-02-01

    Increased organismic complexity in metazoans was achieved via the specialization of certain parts of the body involved in different faculties (structure-function complexes). One of the most basic metabolic demands of animals in general is a sufficient supply of all tissues with oxygen. Specialized structures for gas exchange (and transport) consequently evolved many times and in great variety among bilaterians. This review focuses on some of the latest advancements that morphological research has added to our understanding of how the respiratory apparatus of the primarily terrestrial vertebrates (amniotes) works and how it evolved. Two main components of the respiratory apparatus, the lungs as the "exchanger" and the ventilatory apparatus as the "active pump," are the focus of this paper. Specific questions related to the exchanger concern the structure of the lungs of the first amniotes and the efficiency of structurally simple snake lungs in health and disease, as well as secondary functions of the lungs in heat exchange during the evolution of sauropod dinosaurs. With regard to the active pump, I discuss how the unique ventilatory mechanism of turtles evolved and how understanding the avian ventilatory strategy affects animal welfare issues in the poultry industry. PMID:27037667

  6. [Experimental studies on effects of excessive iodine intake on morphology and function of kidney in mice].

    PubMed

    Zhou, X; Yin, G

    1996-11-01

    To understand that if excessive iodine can cause damage to tissues other than thyroid gland, mice were fed with iodine-excess water and iodine-excess goiter was caused in them. Hisitomorphology and function of the kidney, in addition to the thyroid gland, in goiter mice were observed. Results showed that two hundred days after being fed with 3,000 micrograms iodine per liter water, in addition to causing iodine-excess goiter characterized with proliferation of large amount of colloid in thyroid follicles, morphology and function of the kidneys in mice were significantly damaged, with prominent pathomorphological changes of crescent formation and metabolic inhibition in microsome membrane Na(+)-K(+)-ATPase activities in their kidneys. Na(+)-K(+)-ATPase activities were 21.95 +/- 7.50 mumolPi/mg Pr.hr in low iodine group, and 17.64 +/- 8.63 mumolPi/mg Pr.hr in excessive iodine group, with significant difference. It suggests that excessive iodine can cause damage not only to thyroid, but to the whole body.

  7. Striatal pleiotrophin overexpression provides functional and morphological neuroprotection in the 6-hydroxydopamine model.

    PubMed

    Gombash, Sara E; Lipton, Jack W; Collier, Timothy J; Madhavan, Lalitha; Steece-Collier, Kathy; Cole-Strauss, Allyson; Terpstra, Brian T; Spieles-Engemann, Anne L; Daley, Brian F; Wohlgenant, Susan L; Thompson, Valerie B; Manfredsson, Fredric P; Mandel, Ronald J; Sortwell, Caryl E

    2012-03-01

    Neurotrophic factors are integrally involved in the development of the nigrostriatal system and in combination with gene therapy, possess great therapeutic potential for Parkinson's disease (PD). Pleiotrophin (PTN) is involved in the development, maintenance, and repair of the nigrostriatal dopamine (DA) system. The present study examined the ability of striatal PTN overexpression, delivered via psueudotyped recombinant adeno-associated virus type 2/1 (rAAV2/1), to provide neuroprotection and functional restoration from 6-hydroxydopamine (6-OHDA). Striatal PTN overexpression led to significant neuroprotection of tyrosine hydroxylase immunoreactive (THir) neurons in the substantia nigra pars compacta (SNpc) and THir neurite density in the striatum, with long-term PTN overexpression producing recovery from 6-OHDA-induced deficits in contralateral forelimb use. Transduced striatal PTN levels were increased threefold compared to adult striatal PTN expression and approximated peak endogenous developmental levels (P1). rAAV2/1 vector exclusively transduced neurons within the striatum and SNpc with approximately half the total striatal volume routinely transduced using our injection parameters. Our results indicate that striatal PTN overexpression can provide neuroprotection for the 6-OHDA lesioned nigrostriatal system based upon morphological and functional measures and that striatal PTN levels similar in magnitude to those expressed in the striatum during development are sufficient to provide neuroprotection from Parkinsonian insult.

  8. Functional and Morphological Improvement of Dystrophic Muscle by Interleukin 6 Receptor Blockade

    PubMed Central

    Pelosi, Laura; Berardinelli, Maria Grazia; De Pasquale, Loredana; Nicoletti, Carmine; D'Amico, Adele; Carvello, Francesco; Moneta, Gian Marco; Catizone, Angela; Bertini, Enrico; De Benedetti, Fabrizio; Musarò, Antonio

    2015-01-01

    The anti-inflammatory agents glucocorticoids (GC) are the only available treatment for Duchenne muscular dystrophy (DMD). However, long-term GC treatment causes muscle atrophy and wasting. Thus, targeting specific mediator of inflammatory response may be more specific, more efficacious, and with fewer side effects. The pro-inflammatory cytokine interleukin (IL) 6 is overproduced in patients with DMD and in the muscle of mdx, the animal model for human DMD. We tested the ability of inhibition of IL6 activity, using an interleukin-6 receptor (Il6r) neutralizing antibody, to ameliorate the dystrophic phenotype. Blockade of endogenous Il6r conferred on dystrophic muscle resistance to degeneration and alleviated both morphological and functional consequences of the primary genetic defect. Pharmacological inhibition of IL6 activity leaded to changes in the dystrophic muscle environment, favoring anti-inflammatory responses and improvement in muscle repair. This resulted in a functional homeostatic maintenance of dystrophic muscle. These data provide an alternative pharmacological strategy for treatment of DMD and circumvent the major problems associated with conventional therapy. PMID:26137572

  9. Three-Dimensional Reconstructions Come to Life – Interactive 3D PDF Animations in Functional Morphology

    PubMed Central

    van de Kamp, Thomas; dos Santos Rolo, Tomy; Vagovič, Patrik; Baumbach, Tilo; Riedel, Alexander

    2014-01-01

    Digital surface mesh models based on segmented datasets have become an integral part of studies on animal anatomy and functional morphology; usually, they are published as static images, movies or as interactive PDF files. We demonstrate the use of animated 3D models embedded in PDF documents, which combine the advantages of both movie and interactivity, based on the example of preserved Trigonopterus weevils. The method is particularly suitable to simulate joints with largely deterministic movements due to precise form closure. We illustrate the function of an individual screw-and-nut type hip joint and proceed to the complex movements of the entire insect attaining a defence position. This posture is achieved by a specific cascade of movements: Head and legs interlock mutually and with specific features of thorax and the first abdominal ventrite, presumably to increase the mechanical stability of the beetle and to maintain the defence position with minimal muscle activity. The deterministic interaction of accurately fitting body parts follows a defined sequence, which resembles a piece of engineering. PMID:25029366

  10. Functional and Morphological Improvement of Dystrophic Muscle by Interleukin 6 Receptor Blockade.

    PubMed

    Pelosi, Laura; Berardinelli, Maria Grazia; De Pasquale, Loredana; Nicoletti, Carmine; D'Amico, Adele; Carvello, Francesco; Moneta, Gian Marco; Catizone, Angela; Bertini, Enrico; De Benedetti, Fabrizio; Musarò, Antonio

    2015-04-01

    The anti-inflammatory agents glucocorticoids (GC) are the only available treatment for Duchenne muscular dystrophy (DMD). However, long-term GC treatment causes muscle atrophy and wasting. Thus, targeting specific mediator of inflammatory response may be more specific, more efficacious, and with fewer side effects. The pro-inflammatory cytokine interleukin (IL) 6 is overproduced in patients with DMD and in the muscle of mdx, the animal model for human DMD. We tested the ability of inhibition of IL6 activity, using an interleukin-6 receptor (Il6r) neutralizing antibody, to ameliorate the dystrophic phenotype. Blockade of endogenous Il6r conferred on dystrophic muscle resistance to degeneration and alleviated both morphological and functional consequences of the primary genetic defect. Pharmacological inhibition of IL6 activity leaded to changes in the dystrophic muscle environment, favoring anti-inflammatory responses and improvement in muscle repair. This resulted in a functional homeostatic maintenance of dystrophic muscle. These data provide an alternative pharmacological strategy for treatment of DMD and circumvent the major problems associated with conventional therapy.

  11. Three-dimensional reconstructions come to life--interactive 3D PDF animations in functional morphology.

    PubMed

    van de Kamp, Thomas; dos Santos Rolo, Tomy; Vagovič, Patrik; Baumbach, Tilo; Riedel, Alexander

    2014-01-01

    Digital surface mesh models based on segmented datasets have become an integral part of studies on animal anatomy and functional morphology; usually, they are published as static images, movies or as interactive PDF files. We demonstrate the use of animated 3D models embedded in PDF documents, which combine the advantages of both movie and interactivity, based on the example of preserved Trigonopterus weevils. The method is particularly suitable to simulate joints with largely deterministic movements due to precise form closure. We illustrate the function of an individual screw-and-nut type hip joint and proceed to the complex movements of the entire insect attaining a defence position. This posture is achieved by a specific cascade of movements: Head and legs interlock mutually and with specific features of thorax and the first abdominal ventrite, presumably to increase the mechanical stability of the beetle and to maintain the defence position with minimal muscle activity. The deterministic interaction of accurately fitting body parts follows a defined sequence, which resembles a piece of engineering. PMID:25029366

  12. 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

  13. The morphology of ceramic phases in B {sub x} C-SiC-Si infiltrated composites

    SciTech Connect

    Hayun, S.; Frage, N. . E-mail: nfrage@bgu.ac.il; Dariel, M.P.

    2006-09-15

    The present communication is concerned with the effect of the carbon source on the morphology of reaction bonded boron carbide (B{sub 4}C). Molten silicon reacts strongly and rapidly with free carbon to form large, faceted, regular polygon-shaped SiC particles, usually embedded in residual silicon pools. In the absence of free carbon, the formation of SiC relies on carbon that originates from within the boron carbide particles. Examination of the reaction bonded boron carbide revealed a core-rim microstructure consisting of boron carbide particles surrounded by secondary boron carbide containing some dissolved silicon. This microstructure is generated as the outcome of a dissolution-precipitation process. In the course of the infiltration process molten Si dissolves some boron carbide until its saturation with B and C. Subsequently, precipitation of secondary boron carbide enriched with boron and silicon takes place. In parallel, elongated, strongly twinned, faceted SiC particles are generated by rapid growth along preferred crystallographic directions. This sequence of events is supported by X-ray diffraction and microcompositional analysis and well accounted for by the thermodynamic analysis of the ternary B-C-Si system. - Graphical abstract: Bright field TEM image of the rim area between two boron carbide grains.

  14. 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

  15. Quasi-two-dimensional diamond crystals: Deposition from a gaseous phase and structural-morphological properties

    NASA Astrophysics Data System (ADS)

    Alexeev, A. M.; Ismagilov, R. R.; Ashkinazi, E. E.; Orekhov, A. S.; Malykhin, S. A.; Obraztsov, A. N.

    2016-07-01

    Diamond films predominantly consisting of plane micrometer-size crystallites with a thickness of several dozen nanometers have been deposited from a methane-hydrogen gas mixture activated by a dc gas discharge. The crystallite structure has been studied by scanning and transmission electron microscopy and diffraction. A possible mechanism of formation of plane crystallites during deposition of diamond from the gas phase has been discussed. It has been shown that the results agree with the theoretical concepts of formation of crystals with a face-centered cubic lattice.

  16. Functional and morphological correlates of mandibular symphyseal form in a living human sample.

    PubMed

    Holton, Nathan E; Franciscus, Robert G; Ravosa, Matthew J; Southard, Thomas E

    2014-03-01

    Variation in recent human mandibular form is often thought to reflect differences in masticatory behavior associated with variation in food preparation and subsistence strategies. Nevertheless, while mandibular variation in some human comparisons appear to reflect differences in functional loading, other comparisons indicate that this relationship is not universal. This suggests that morphological variation in the mandible is influenced by other factors that may obscure the effects of loading on mandibular form. It is likely that highly strained mandibular regions, including the corpus, are influenced by well-established patterns of lower facial skeletal integration. As such, it is unclear to what degree mandibular form reflects localized stresses incurred during mastication vs. a larger set of correlated features that may influence bone distribution patterns. In this study, we examine the relationship between mandibular symphyseal bone distribution (i.e., second moments of area, cortical bone area) and masticatory force production (i.e., in vivo maximal bite force magnitude and estimated symphyseal bending forces) along with lower facial shape variation in a sample of n = 20 living human male subjects. Our results indicate that while some aspects of symphyseal form (e.g., wishboning resistance) are significantly correlated with estimates of symphyseal bending force magnitude, others (i.e., vertical bending resistance) are more closely tied to variation in lower facial shape. This suggests that while the symphysis reflects variation in some variables related to functional loading, the complex and multifactorial influences on symphyseal form underscores the importance of exercising caution when inferring function from the mandible especially in narrow taxonomic comparisons.

  17. 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

  18. Roots Revealed - Neutron imaging insight of spatial distribution, morphology, growth and function

    NASA Astrophysics Data System (ADS)

    Warren, J.; Bilheux, H.; Kang, M.; Voisin, S.; Cheng, C.; Horita, J.; Perfect, E.

    2013-05-01

    Root production, distribution and turnover are not easily measured, yet their dynamics are an essential part of understanding and modeling ecosystem response to changing environmental conditions. Root age, order, morphology and mycorrhizal associations all regulate root uptake of water and nutrients, which along with along with root distribution determines plant response to, and impact on its local environment. Our objectives were to demonstrate the ability to non-invasively monitor fine root distribution, root growth and root functionality in Zea mays L. (maize) and Panicum virgatum L. (switchgrass) seedlings using neutron imaging. Plants were propagated in aluminum chambers containing sand then placed into a high flux cold neutron beam line. Dynamics of root distribution and growth were assessed by collecting consecutive CCD radiographs through time. Root functionality was assessed by tracking individual root uptake of water (H2O) or deuterium oxide (D2O) through time. Since neutrons strongly scatter H atoms, but not D atoms, biological materials such as plants are prime candidates for neutron imaging. 2D and 3D neutron radiography readily illuminated root structure, root growth, and relative plant and soil water content. Fungal hyphae associated with the roots were also visible and appeared as dark masses since their diameter was likely several orders of magnitude less than ~100 μm resolution of the detector. The 2D pulse-chase irrigation experiments with H2O and D2O successfully allowed observation of uptake and mass flow of water within the root system. Water flux within individual roots responded differentially to foliar illumination based on internal water potential gradients, illustrating the ability to track root functionality based on root size, order and distribution within the soil. (L) neutron image of switchgrass growing in sandy soil with 100 μm diameter roots (R) 3D reconstruction of maize seedling following neutron tomography

  19. On morphology and strain field of Ge/Si(001) Islands according to TEM phase imaging method.

    PubMed

    Donnadieu, P; Neisius, T; Amiard, G; Gouyé, A; Ronda, A; Berbezier, I

    2011-10-01

    The mechanism driving Germanium islands nucleation and self-assembly is an important effect for opto-electronic applications, still not fully understood. We demonstrate that the new transmission electron microscopy phase imaging method provides insights on the distribution of strain and composition fields in and around the islands on rather large areas. The method consists of retrieving the phase from a focus series of plane view images. The phase image is representative of morphology, composition and strain. The results show that whatever the islands size and shape is, a maximum compressive strain is obtained at the apex of the islands compensated by a maximum tensile strain in the substrate close to the islands perimeter. The maximum compressive strain is associated to a larger Ge concentration. The distribution of tensile strain varies with the shape of the islands: for square base pyramidal "hut" islands, a maximum tensile strain is obtained at the four corners of the pyramid base and for "dome" islands, the tensile strain is less pronounced and affects almost the whole island perimeter. These results are consistent with the higher strain relaxation level of "dome" islands in comparison to those of "hut" islands. PMID:22400325

  20. 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

  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. Bisphenol A affects placental layers morphology and angiogenesis during early pregnancy phase in mice.

    PubMed

    Tait, Sabrina; Tassinari, Roberta; Maranghi, Francesca; Mantovani, Alberto

    2015-11-01

    Bisphenol A (BPA) is a widespread endocrine disrupter mainly used in food contact plastics. Much evidence supports the adverse effects of BPA, particularly on susceptible groups such as pregnant women. The present study considered placental development - relevant for pregnancy outcomes and fetal nutrition/programming - as a potential target of BPA. Pregnant CD-1 mice were administered per os with vehicle, 0.5 (BPA05) or 50 mg kg(-1) (BPA50) body weight day(-1) of BPA, from gestational day (GD) 1 to GD11. At GD12, BPA50 induced significant degeneration and necrosis of giant cells, increased vacuolization in the junctional zone in the absence of glycogen accumulation and reduction of the spongiotrophoblast layer. In addition, BPA05 induced glycogen depletion as well as significant nuclear accumulation of β-catenin in trophoblasts of labyrinthine and spongiotrophoblast layers, supporting the activation of the Wnt/β-catenin pathway. Transcriptomic analysis indicated that BPA05 promoted and BPA50 inhibited blood vessel development and branching; morphologically, maternal vessels were narrower in BPA05 placentas, whereas embryonic and maternal vessels were irregularly dilated in the labyrinth of BPA50 placentas. Quantitative polymerase chain reaction evidenced an estrogen receptor β induction by BPA50, which did not correspond to downstream genes activation; indeed, the transcription factor binding sites analysis supported the AhR/Arnt complex as regulator of BPA50-modulated genes. Conversely, Creb appeared as the main transcription factor regulating BPA05-modulated genes. Embryonic structures (head, forelimb) showed divergent perturbations upon BPA05 or BPA50 exposure, potentially related to unbalanced embryonic nutrition and/or to modulation of genes involved in embryo development. Our findings support placenta as an important target of BPA, even at environmentally relevant dose levels. PMID:26063408

  3. Lyotropic Phase Behavior of Poly(ethylene oxide)-Poly(butadiene) Diblock Copolymers: Evolution of the Random Network Morphology

    SciTech Connect

    Jain, Sumeet; Dyrdahl, Mitchell H.E.; Gong, Xiaobo; Scriven, L.E.; Bates, Frank S.

    2008-10-24

    The phase behavior of poly(ethylene oxide)-poly(butadiene) (PEO-PB) diblock copolymers mixed with water was studied using small-angle X-ray scattering (SAXS), cryogenic scanning electron microscopy (cryo-SEM), cryogenic transmission electron microscopy (cryo-TEM), and dynamic mechanical spectroscopy. Two sets of diblocks were synthesized by adding different lengths of PEO to hydroxy terminated PB with degrees of polymerization N{sub PB} = 46 and 170. Two-component mixtures were investigated as a function of block composition and copolymer molecular weight, between 1 and 100 wt % polymer content. Melt phase behavior is consistent with established theory and known experimental behavior for diblock copolymers. Various lyotropic liquid crystalline structures, notably lamellae (L), hexagonally packed cylinders (H), and spheres (S) arranged on cubic (body-centered cubic, face-centered cubic) lattices, were documented as a function of water content. At the higher molecular weights (N{sub PB} = 170), a random network phase (N) was identified over a sizable portion of the phase portrait, located between hexagonally ordered cylinders and ordered lamellae. This new structure, along with branching of cylindrical micelles in the dilute limit, bear a striking similarity to experimentally observed and theoretically predicted phase behavior in certain ternary water/oil/surfactant systems. These findings demonstrate that block copolymer surfactants are characterized by at least four structural building blocks -- spheres, cylinders, bilayers, and branched cylinders -- above a threshold molecular weight.

  4. Morphological evolution and migration of void in bi-piezoelectric interface based on nonlocal phase field method

    NASA Astrophysics Data System (ADS)

    Li, H. B.; Wang, X.

    2016-05-01

    This paper reports the result of investigation into the morphological evolution and migration of void in bi-piezoelectric material interface by utilizing nonlocal phase field model and finite element method (FEM), where the small scale effect containing the long-range forces among atoms is considered. The nonlocal elastic strain energy and the nonlocal electric energy around the void are firstly calculated by the finite element method. Then based on the finite difference method (FDM), the thermodynamic equilibrium equation containing the surface energy and anisotropic diffusivity is solved to simulate the morphological evolution and migration of elliptical void in bi-piezoelectric films interface. Results show that the way of load condition plays a significant role in the evolution process, and the boundary of void's long axis gradually collapses toward the center of ellipse. In addition, the evolutionary speed of left boundary gradually decreases with scale effect coefficient growth. This work can provide references for the safety evaluation of piezoelectric materials in micro electro mechanical system.

  5. 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

  6. 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.

  7. 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. PMID:25519065

  8. 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.

  9. 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.

  10. 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.

  11. 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. PMID:27623751

  12. 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.

  13. Morphological and Behavioural Evidence for Impaired Prefrontal Cortical Function in Female CB1 Receptor Deficient Mice

    PubMed Central

    Lee, Tiffany T.-Y.; Filipski, Sarah B.; Hill, Matthew N.; McEwen, Bruce S.

    2014-01-01

    The medial prefrontal cortex (mPFC) is known to regulate higher order processes like cognitive flexibility. Accumulating behavioral evidence suggests that endocannabinoid (eCB) signaling regulates neuronal architecture within the PFC, as well as certain forms of cognitive flexibility; however, all of these studies have been performed in male rodents and it is currently unknown whether the eCB system performs a similar role in females. To this extent, dendritic morphology of layer II/III neurons in the infra- and prelimbic regions of the mPFC was analyzed and cognitive ability and flexibility in a fixed-platform Morris water maze task was assessed in adult female CB1 receptor knockout (CB1KO) mice. Similar to data generated in male mice, female mice exhibited no difference in acquisition relative to wildtype (WT); however, during reversal learning, CB1KO females spent more time in the original training quadrant and took significantly longer to learn the location of the new platform relative to WT. Within the mPFC, female mice had reduced length and complexity of layer II/III neurons within the prelimbic, but not infralimbic region of the PFC. Taken together, these findings indicate that the role of eCB signaling in cognitive flexibility is independent of sex and disrupted CB1 receptor signaling results in compromised structure and function of the PFC, at least within the prelimbic division. PMID:24907533

  14. 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. PMID:24054264

  15. Deiodinase knockdown affects zebrafish eye development at the level of gene expression, morphology and function.

    PubMed

    Houbrechts, Anne M; Vergauwen, Lucia; Bagci, Enise; Van Houcke, Jolien; Heijlen, Marjolein; Kulemeka, Bernard; Hyde, David R; Knapen, Dries; Darras, Veerle M

    2016-03-15

    Retinal development in vertebrates relies extensively on thyroid hormones. Their local availability is tightly controlled by several regulators, including deiodinases (Ds). Here we used morpholino technology to explore the roles of Ds during eye development in zebrafish. Transcriptome analysis at 3 days post fertilization (dpf) revealed a pronounced effect of knockdown of both T4-activating Ds (D1D2MO) or knockdown of T3-inactivating D3 (D3bMO) on phototransduction and retinoid recycling. This was accompanied by morphological defects (studied from 1 to 7 dpf) including reduced eye size, disturbed retinal lamination and strong reduction in rods and all four cone types. Defects were more prominent and persistent in D3-deficient fish. Finally, D3-deficient zebrafish larvae had disrupted visual function at 4 dpf and were less sensitive to a light stimulus at 5 dpf. These data demonstrate the importance of TH-activating and -inactivating Ds for correct zebrafish eye development, and point to D3b as a central player. PMID:26802877

  16. Film morphology, orientation and performance of dodecyl/carboxyl functional polysiloxane on cotton substrates

    NASA Astrophysics Data System (ADS)

    An, Qiufeng; Wang, Kefeng; Jia, Yun

    2011-03-01

    A novel polysiloxane (RCAS) bearing dodecyl and carboxyl side groups was synthesized by reaction of a dodecyl/amino functionalized polysiloxane with maleic anhydride. Film morphology, molecular orientation and performance of the synthesized polysiloxane on cotton substrates were investigated by field emission scanning electron microscope (FESEM), atomic force microscope (AFM), X-ray photoelectron microscope (XPS) and so on. Affected by the dodecyl and polar carboxyl side groups, RCAS formed a semi hydrophilic, macroscopic smooth but actually uneven siloxane film with many pillar-likes or small humps on the treated substrate surfaces. On the natural cotton surface, RCAS may take such an orientation to form its film that the Si-CH3, Si-C12H25 groups projected outward into air, while the carboxyl groups pointed inward to the substrate, interacting with the hydroxyls of the cotton substrates in ester and hydrogen bonds or twisted away from the negatively charged cotton fiber surface. As a result of such a film-formation, RCAS provided the treated fabric with not only a good wettability of about 22.96 s and a whiteness of 88.44°, but also an improved softness as well as thickening handle.

  17. 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.

  18. 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.

  19. Morphology and function of the female reproductive system of Ebalia tumefacta (Decapoda, Brachyura, Leucosiidae).

    PubMed

    Hayer, Sarah; Schubart, Christoph D; Brandis, Dirk

    2015-05-01

    In this article, the morphology and function of the female reproductive organs of Ebalia tumefacta were investigated using histological methods. While the vagina conforms to the concave type, the study reveals a new orientation of seminal receptacle compartments. The seminal receptacle consists of two chambers, which are oriented in anterior-posterior direction. This is in contrast to the dorso-ventral orientation of seminal receptacle chambers in all other known brachyuran crabs. The anterior chamber is lined by cuticle, whereas the posterior chamber is covered with a holocrine glandular epithelium. The oviduct connection is located ventrally, close to the opening of the vagina. The oviduct orifice is characterized by a transition of the epithelium lining of the oviduct to the seminal receptacle holocrine glandular epithelium. Special features are muscle fibers, which are attached to the oviduct orifice and to the sternal cuticle as well. The muscle fibers can be found exactly at that point where the oviduct opens into the seminal receptacle and are secondly attached to the sternum beneath. This musculature is newly described for Eubrachyuran crabs. This musculature can be interpreted as an important feature in the fertilization and egg-laying process in relation to supporting and controling the inflow of eggs into the seminal receptacle lumen. These new discoveries were compared to the known pattern of an Eubrachyuran seminal receptacle.

  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. 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.

  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. 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.

  5. 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.

  6. Ovarian function and morphology after deletion of the DARPP-32 gene in mice.

    PubMed

    Mayerhofer, A; Fritz, S; Mani, S; Rajendra Kumar, T; Thalhammer, A; Ingrassia, P; Fienberg, A A; Greengard, P

    2004-09-01

    A plethora of systemic and local signaling molecules regulate ovarian function, but how different signaling molecules interact within an ovarian target cell is not known. Here we report that endocrine cells of the ovary express a phosphoprotein, DARPP-32 (dopamine and cyclic AMP-regulated phosphoprotein of Mr 32,000), which integrates signaling molecules in neurons. We thus hypothesized that DARPP-32 might act in a similar way in ovarian endocrine cells and therefore studied whether DARPP-32 gene deletion has consequences for ovarian functions in mice. Reproductive performance of adult mutants did not differ from wild-type females, as judged from numbers of litters and pups delivered. Similar steroid levels in mutant and wild-type mice ruled out gross abnormalities in the hypothalamic-pituitary-ovarian axis. However, an analysis of ovarian morphology, using serially sectioned ovaries, revealed several differences. Ovaries of young adult mutant mice at 2 - 3 months contained luteinized follicles, but fewer corpora lutea. At 5 - 6 months, large cysts were found in mutant mice, as well as reduced numbers of preantral follicles and antral follicles. Interstitial cell hypertrophy and degeneration was marked in all mutant ovaries at this age. Thus, while the lack of DARPP-32 does not overtly alter reproductive performance in adult mice, it is associated with progressive alterations and derangements of growth and development of ovarian follicles, suggesting premature ovarian ageing. This implies that ovarian DARPP-32 is involved in follicular development, presumably by integrating effects of signaling molecules, which act together to ensure efficient follicular development.

  7. 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

  8. The effect of morphological and functional variables on ranking position of professional junior Basque surfers.

    PubMed

    Fernández-López, Juan Ramón; Cámara, Jesús; Maldonado, Sara; Rosique-Gracia, Javier

    2013-01-01

    The aim of this study was to analyse the association of morphology as well as functional outcomes during a paddling test with ranking position (RP) of competitive junior surfers. Ten male surfers (age, mean 17.60, s=2.06 years) performed a maximum incremental test on a modified ergometer (Ergo Vasa Swim, USA) to determine, per unit of weight, the relative heart rate at lactate threshold (RHRLT) and at onset of blood lactate accumulation (RHROBLA) and the relative power output at LT (RWLT) and at OBLA (RWOBLA). Anthropometrics were weight, height and sum of six skinfolds (subscapular, triceps, supraspinal, abdominal, anterior thigh and calf) and Heath-Carter anthropometric somatotypes. A stepwise multiple regression was constructed to model and predict RP. Surfers shared a relative short stature and light weight, with a broader range of skinfold thickness (174.30, s=0.07 cm; 66.73, s=5.91 kg; 57.03, s=12.29 mm) and mean somatotype was ectomorphic-mesomorph: 2.20-4.36-3.09 (Category 2). Two model equations were possible: (A) RP = - 244.550 RWOBLA+262.787; (B) RP = - 217.028·RWOBLA+31.21·endomorphy + 169.16 with 63.1% and 83% of variance explained, respectively. A hierarchical cluster analysis on the Euclidean distances of the variables in model B also distinguished between upper and lower ranking groups. RWOBLA was more useful than endomorphy, anthropometric measures and also than the other functional outcomes to predict RPs. RWOBLA and endomorphy should be considered important variables that may influence the success of these young competitive surfers. PMID:24050462

  9. Differential role of APP and APLPs for neuromuscular synaptic morphology and function.

    PubMed

    Klevanski, Maja; Saar, Martina; Baumkötter, Frederik; Weyer, Sascha W; Kins, Stefan; Müller, Ulrike C

    2014-07-01

    The analysis of mouse models indicated that APP and the related APLPs are important for synapse formation and function. The synaptic role of APP is, however, complex due to partially overlapping functions within the gene family. APP/APLPs are proteolytically cleaved and have both adhesive and signaling properties. Mice lacking individual APP family members are viable, whereas APP/APLP2 and APLP1/APLP2 double knockout (DKO) mice die shortly after birth. Here, we analyzed the morphology of the neuromuscular junction (NMJ) of lethal APLP1/APLP2-DKO mice in comparison to lethal APP/APLP2-DKO mutants and viable single KO mice. We report that, surprisingly, the NMJ phenotype of APLP1/APLP2-DKO mice shows striking differences as compared to APP/APLP2-DKO mice. Unexpectedly, APLP1/APLP2-DKO mice exhibit normal endplate patterning and lack presynaptic nerve terminal sprouting. However, at the level of individual synapses we show that APLP1/APLP2-DKO mice exhibit reduced size of pre- and postsynaptic compartments and reduced colocalization. As APP/APLP2-DKO and APLP1/APLP2-DKO mice show similar penetrance of early postnatal lethality, this suggests that deficits at the level of individual synapses due to impaired synaptic apposition and/or deficits in transmitter release may cause lethality. Using an in vitro cell-adhesion assay, we observed that APP trans-dimerization is considerably less efficient than APLP2 trans-interaction. Thus, differences between APP/APLP2 and APP/APLP1 NMJ formation may be in part explained by differences in APP/APLP2 trans-dimerization properties. Collectively, our study further highlights the distinct and essential role of APLP2 at NMJ synapses that cannot be compensated by APP. PMID:24998676

  10. The effect of morphological and functional variables on ranking position of professional junior Basque surfers.

    PubMed

    Fernández-López, Juan Ramón; Cámara, Jesús; Maldonado, Sara; Rosique-Gracia, Javier

    2013-01-01

    The aim of this study was to analyse the association of morphology as well as functional outcomes during a paddling test with ranking position (RP) of competitive junior surfers. Ten male surfers (age, mean 17.60, s=2.06 years) performed a maximum incremental test on a modified ergometer (Ergo Vasa Swim, USA) to determine, per unit of weight, the relative heart rate at lactate threshold (RHRLT) and at onset of blood lactate accumulation (RHROBLA) and the relative power output at LT (RWLT) and at OBLA (RWOBLA). Anthropometrics were weight, height and sum of six skinfolds (subscapular, triceps, supraspinal, abdominal, anterior thigh and calf) and Heath-Carter anthropometric somatotypes. A stepwise multiple regression was constructed to model and predict RP. Surfers shared a relative short stature and light weight, with a broader range of skinfold thickness (174.30, s=0.07 cm; 66.73, s=5.91 kg; 57.03, s=12.29 mm) and mean somatotype was ectomorphic-mesomorph: 2.20-4.36-3.09 (Category 2). Two model equations were possible: (A) RP = - 244.550 RWOBLA+262.787; (B) RP = - 217.028·RWOBLA+31.21·endomorphy + 169.16 with 63.1% and 83% of variance explained, respectively. A hierarchical cluster analysis on the Euclidean distances of the variables in model B also distinguished between upper and lower ranking groups. RWOBLA was more useful than endomorphy, anthropometric measures and also than the other functional outcomes to predict RPs. RWOBLA and endomorphy should be considered important variables that may influence the success of these young competitive surfers.

  11. Functioning of family system in pediatric oncology during treatment phase.

    PubMed

    Perricone, Giovanna; Polizzi, Concetta; Morales, Maria Regina; Marino, Santo; Scacco, Cinzia Favara

    2012-10-01

    The study focuses on parents' psychological implications caused by the treatment of their children suffering from tumor. It investigates some specific mothers' resource factors such as their strategies of coping and the perception of their own family functioning in terms of cohesion and adaptability. The study was performed with 34 mothers of children suffering from acute lymphoblastic leukemia (ALL), during the treatment phase. The used tools were the Coping Orientation to Problem Experienced--New Italian Version, to investigate coping strategies, and the Family Adaptability and Cohesion Evaluation Scale-III, to analyze both real and ideal perception of family functioning. The data related to coping, show how the involved mothers tend to mainly use the strategies of positive aptitude, orientation toward problem and social support (F = 99.88, df = 4, P < .01). The family functioning, in terms of adaptability, is described as chaotic relating to both the real (χ(2) = 13.29, df = 3, P = .004) and ideal (χ(2) = 11.52, df = 2, P = .003) family, whereas in terms of cohesion, it is perceived as chiefly disengaged in the real family (χ(2) = 12.3, df = 3, P = .006) and as enmeshed in the ideal one (χ(2) = 12.58, df = 3, P = .006). Statistically positive correlations were only detected between adaptability and avoidance (r = 0.49, P < .01); adaptability and orientation toward problem (r = 0.36, P < .05); and adaptability and transcendent orientation (r = -0.04, P < .05). Despite the critical situation, the mothers have shown optimistic view, care for problem management and capability to ask for help. These coping strategies allow the therapeutic alliance between families and health care workers, so useful for the quality of childcare. PMID:22732085

  12. Coarsening Kinetics and Morphological Evolution in a Two-Phase Titanium Alloy During Heat Treatment

    NASA Astrophysics Data System (ADS)

    Xu, Jianwei; Zeng, Weidong; Jia, Zhiqiang; Sun, Xin; Zhao, Yawei

    2016-03-01

    The effects of alpha/beta heat treatment on microstructure evolution of Ti-17 alloy with a lamellar colony structure are established. Heat treatment experiments are conducted at 1103 or 1063 K for times ranging from 10 min to 8 h. The main features of microstructure evolution during heat treatment comprise static globularization and coarsening of primary alpha phase. Such behaviors can be accelerated by higher heat treatment temperature. Furthermore, globularization and coarsening behaviors show a faster rate at higher prestrain. In order to better understand the microstructure evolution of Ti-17 alloy during alpha/beta heat treatment, static globularization and coarsening behaviors are modeled in the theoretical frame of the Johnson-Mehl-Avarmi-Kolmogorov (JMAK) and Lifshitz-Slyozov-Wagner (LSW) theories, respectively. The JMAK and LSW kinetics parameters are derived under different experimental conditions. Agreements between measurements and predictions are found, indicating that the JMAK and LSW theories can be used to predict and trace static globularization and coarsening processes of Ti-17 alloy during alpha/beta heat treatment.

  13. 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.

  14. Rheology, Morphology and Phase Behavior in Amphiphilic Block Copolymer/microemulsion Systems

    NASA Astrophysics Data System (ADS)

    Gottlieb, Moshe; Braun, Liora; Zhang, Zeng-Rong

    2000-03-01

    Joining together by means of covalent bonds hydrophobic and hydrophilic entities on the same molecule gives rise to materials with interesting properties in aqueous systems or in the presence of mixed solvents such as water/oil microemulsions. In this paper we describe the rheological properties of a synthetic amphiphilic block copolymer dissolved in a water-in-oil microemulsion. The block copolymer is an ABA type copolymer composed of poly(oxyethylene) (PEO) as the hydrophilic A block and poly(dimethyl siloxane) (PDMS) as the hydrophobic center B block. Different polymers have been prepared with a B block of D_p=160 and three different sizes of the A blocks with D_p= 10, 45, and 120 respectively. The resulting copolymer is insoluble in water and hardly soluble in decane (good solvent for the PDMS). In the presence of water in oil microemulsion stabilized by the small molecular weight surfactant AOT a one-phase region is maintained when the copolymer is added. Yet, peculiar rheological behavior is observed. For constant water-microemulsion concentration (φ) addition of polymer increases the system viscosity as expected. Yet, the lower φ the higher the viscosity and at high φ the effect of polymer addition is quite low.

  15. Crystalline Morphology and Polymorphic Phase Transitions in Electrospun Nylon-6 Nanofibers

    SciTech Connect

    Liu,Y.; Cui, L.; Guan, F.; Gao, Y.; Hedin, N.; Zhu, L.; Fong, H.

    2007-01-01

    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 T{sub g} (340 C) polyimide confined nanofibers were studied. Similar to melt-spun nylon-6 fibers, electrospun nylon-6 nanofibers also exhibited predominant, metastable {gamma}-crystalline form, and the {gamma}-crystal (chain) axes preferentially oriented parallel to the fiber axis. Upon annealing above 150 C, {gamma}-form crystals gradually melted and recrystallized into thermodynamically stable {alpha}-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; {gamma}-form crystals did not melt and recrystallize into {alpha}-form crystals until 210 C, only 10 C below the T{sub m} at 220 C. After complete melting of nanoconfined crystals at 240 C and recrystallization at 100 C, only {alpha}-form crystals oriented perpendicular to the nanofiber axis were obtained. In the polyimide-confined nanofibers, the Brill transition (from the monoclinic {alpha}-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 {approx}160 C. This, again, was attributed to the confinement effect.

  16. Crystalline Morphology and Polymorphic Phase Transitions in Electrospun Nylon 6 Nanofibers.

    PubMed

    Liu, Yi; Cui, Li; Guan, Fangxiao; Gao, Yi; Hedin, Nyle E; Zhu, Lei; Fong, Hao

    2007-01-01

    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 T(g) (340 degrees C) polyimide confined nanofibers were studied. Similar to melt-spun nylon 6 fibers, electrospun nylon 6 nanofibers also exhibited predominant, meta-stable gamma crystalline form, and the gamma-crystal (chain) axes preferentially oriented parallel to the fiber axis. Upon annealing above 150 degrees C, gamma-form crystals gradually melted and recrystallized into the thermodynamically stable alpha-form crystals, which ultimately melted at 220 degrees 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; gamma-form crystals did not melt and recrystallize into alpha-form crystals until 210 degrees C, only 10 degrees C below the T(m) at 220 degrees C. After complete melting of nano-confined crystals at 240 degrees C and recrystallization at 100 degrees C, only alpha-form crystals oriented perpendicular to the nanofiber axis were obtained. In the polyimide-confined nanofibers, the Brill transition (from the monoclinic alpha-form to a high temperature monoclinic form) was observed at 180-190 degrees C, which was at least 20 degrees C higher than that in unconfined nylon 6 at approximately 160 degrees C. This, again, was attributed to the confinement effect.

  17. 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.

  18. 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.

  19. 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. PMID:25086392

  20. 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.

  1. Structural and morphological characteristics of planar (112¯0) a-plane gallium nitride grown by hydride vapor phase epitaxy

    NASA Astrophysics Data System (ADS)

    Haskell, B. A.; Wu, F.; Matsuda, S.; Craven, M. D.; Fini, P. T.; DenBaars, S. P.; Speck, J. S.; Nakamura, Shuji

    2003-08-01

    This letter discusses the structural and morphological characteristics of planar, nonpolar (112¯0) a-plane GaN films grown on (11¯02) r-plane sapphire by hydride vapor phase epitaxy. Specular films with thicknesses over 50 μm were grown, eliminating the severely faceted surfaces that have previously been observed for hydride vapor phase epitaxy-grown a-plane films. Internal cracks and crack healing, similar to that in c-plane GaN films, were observed. Atomic force microscopy revealed nanometer-scale pitting and steps on the film surfaces, with rms roughness of ˜2 nm. X-ray diffraction confirmed the films are solely a-plane oriented with on-axis (112¯0) and 30° off-axis (101¯0) rocking curve peak widths of 1040 and 3000 arcsec, respectively. Transmission electron microscopy revealed a typical basal plane stacking fault density of 4×105cm-1. The dislocation content of the films consisted of predominately edge component (bedge=±[0001]) threading dislocations with a density of 2×1010 cm-2, and mixed-character Shockley partial dislocations (b=1/3<11¯00>) with a density of 7×109 cm-2.

  2. The Impact of Acute Phase Domain-Specific Cognitive Function on Post-stroke Functional Recovery

    PubMed Central

    Park, Jihong; Lee, Gangpyo; Lee, Shi-Uk

    2016-01-01

    Objective To assess whether the cognitive function in the acute stage evaluated by domain-specific neuropsychological assessments would be an independent predictor of functional outcome after stroke. Methods Forty patients underwent 4 domain-specific neuropsychological examinations about 3 weeks after the onset of stroke. The tests included the Boston Naming Test (BNT), the construction recall test (CRT), the construction praxis test (CPT), and the verbal fluency test (VFT). The Korean version of Modified Barthel Index (K-MBI) at 3 months and the modified Rankin Scale (mRS) at 6 months were investigated as functional outcome after stroke. Functional improvement was assessed using the change in K-MBI during the first 3 months and subjects were dichotomized into 'good status' and 'poor status' according to mRS at 6 months. The domain-specific cognitive function along with other possible predictors for functional outcome was examined using regression analysis. Results The z-score of CPT (p=0.044) and CRT (p<0.001) were independent predictors for functional improvement measured by the change in K-MBI during the first 3 months after stroke. The z-score of CPT (p=0.049) and CRT (p=0.048) were also independent predictors of functional status at post-stroke 6 months assessed by mRS. Conclusion Impairment in visuospatial construction and memory within one month after stroke can be an independent prognostic factor of functional outcome. Domain-specific neuropsychological assessments could be considered in patients with stroke in the acute phase to predict long-term functional outcome. PMID:27152270

  3. Contrast transfer functions for Zernike phase contrast in full-field transmission hard X-ray microscopy.

    PubMed

    Yang, Yang; Cheng, Yin; Heine, Ruth; Baumbach, Tilo

    2016-03-21

    Full-field transmission hard X-ray microscopy (TXM) has been widely applied to study morphology and structures with high spatial precision and to dynamic processes. Zernike phase contrast (ZPC) in hard X-ray TXM is often utilized to get an in-line phase contrast enhancement for weak-absorbing materials with little contrast differences. Here, following forward image formation, we derive and simplify the contrast transfer functions (CTFs) of the Zernike phase imaging system in TXM based on a linear space-shift-invariant imaging mode under certain approximations. The CTFs in ZPC in their simplified forms show a high similarity to the one in free-space propagation X-ray imaging systems. PMID:27136800

  4. The phosphoproteome of Aspergillus nidulans reveals functional association with cellular processes involved in morphology and secretion.

    PubMed

    Ramsubramaniam, Nikhil; Harris, Steven D; Marten, Mark R

    2014-11-01

    We describe the first phosphoproteome of the model filamentous fungus Aspergillus nidulans. Phosphopeptides were enriched using titanium dioxide, separated using a convenient ultra-long reverse phase gradient, and identified using a "high-high" strategy (high mass accuracy on the parent and fragment ions) with higher-energy collisional dissociation. Using this approach 1801 phosphosites, from 1637 unique phosphopeptides, were identified. Functional classification revealed phosphoproteins were overrepresented under GO categories related to fungal morphogenesis: "sites of polar growth," "vesicle mediated transport," and "cytoskeleton organization." In these same GO categories, kinase-substrate analysis of phosphoproteins revealed the majority were target substrates of CDK and CK2 kinase families, indicating these kinase families play a prominent role in fungal morphogenesis. Kinase-substrate analysis also identified 57 substrates for kinases known to regulate secretion of hydrolytic enzymes (e.g. PkaA, SchA, and An-Snf1). Altogether this data will serve as a benchmark that can be used to elucidate regulatory networks functionally associated with fungal morphogenesis and secretion. All MS data have been deposited in the ProteomeXchange with identifier PXD000715 (http://proteomecentral.proteomexchange.org/dataset/PXD000715).

  5. 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.

  6. Morphology and phase behavior of ethanol nanodrops condensed on chemically patterned surfaces

    NASA Astrophysics Data System (ADS)

    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 ΔT is used as a fitting parameter. There is a systematic difference between the measured ΔT 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.

  7. Nighttime morphology of vertical plasma drifts at Ouagadougou during different seasons and phases of sunspot cycles 20-22

    NASA Astrophysics Data System (ADS)

    Adebesin, B. O.; Rabiu, A. B.; Adeniyi, J. O.; Amory-Mazaudier, C.

    2015-11-01

    The nighttime morphology of vertical plasma drift (Vd) inferred from ground-based measurements of the F layer height at Ouagadougou (12.4°N, 358.6°E) in the African Equatorial Ionization Anomaly trough was investigated. The observation covers four seasons, four sunspot cycle phases, annual, and 11 year sunspot cycle (SC) variations of the SCs 20-22 spanning 1966-1998 and a first attempt of such study. The annual mean peak magnitudes of Vd during the prereversal enhancement (PRE) and minimum reversal periods exhibit the 11 year sunspot cycle evolution with the sunspot number (Rz). The PRE peak/Rz and reversal peak/Rz relationships are 98.7% and 84.8%, respectively. PRE peak in June solstice appears 1 h later than for other seasons and is attributed to a decrease in the equatorial zonal wind/conductivity gradient. The highest PRE magnitude and downward perturbation drifts near dusk appear during the equinoxes and lowest in June solstice for all cycles. There is semiannual asymmetry in the variation of Vd during all cycles of the PRE event with peaks in March and September/October. A remarkable feature is the consistent local presunrise drift enhancement for two SCs 20 and 21, which is not a regular feature of the equatorial ionosphere. The rate of inhibition of scintillation effect increases with decreasing phase of sunspot activity and maximizes during the solstices. Both the PRE and minimum reversal peak magnitudes are influenced by the phase of sunspot cycle. Ouagadougou data in this study had shown reliable drift characteristics and can be integrated into the African regional empirical drift model.

  8. Protrudin Regulates Endoplasmic Reticulum Morphology and Function Associated with the Pathogenesis of Hereditary Spastic Paraplegia*

    PubMed Central

    Hashimoto, Yutaka; Shirane, Michiko; Matsuzaki, Fumiko; Saita, Shotaro; Ohnishi, Takafumi; Nakayama, Keiichi I.

    2014-01-01

    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. PMID:24668814

  9. 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.

  10. Morphological and functional changes in the rat heart after X irradiation: Strain differences

    SciTech Connect

    Yeung, T.K.; Lauk, S.; Simmonds, R.H.; Hopewell, J.W.; Trott, K.R. )

    1989-09-01

    The hearts of mature male rats of the Wistar and Sprague-Dawley strains were locally irradiated with single doses of 17.5 and 20.0 Gy of X rays, respectively. These two dose levels had previously been shown to result in a comparable latent period between irradiation and the death of rats of these two strains from cardiac failure. Morphological changes in the myocardium and modifications in cardiac function were assessed in the animals at 28, 70, and 100 days after irradiation. The first radiation-induced change which was observed in the myocardium was a rapid decline in capillary density and a loss of alkaline phosphatase activity by the capillary endothelial cells. The capillary density was reduced to approximately 50% of that of unirradiated control values at 28 days and to approximately 40% of the control values between 70 and 100 days after irradiation. The loss of enzyme activity was also detected at 28 days. Examination of histological sections showed an increase by 70 days in the areas with negative enzyme activity up to approximately 70% of the myocardium. The reduction in capillary density and the loss of enzyme activity occurred before any marked pathological changes were seen in the myocardium. The pathological lesions seen in the myocardium at 100 days after irradiation were qualitatively and quantitatively the same in the two strains of rat. Measurements of cardiac output in Sprague-Dawley rats showed a gradual decline in output after irradiation; however, measurements in Wistar rats showed a progressive increase in cardiac output over the same period of time. It was shown by rubidium extraction that there was an increase in the percentage of the total cardiac output distributed to the ventricular muscle of Sprague-Dawley rats, while similar measurements in Wistar rats showed no significant change.

  11. Change in hepatic function, hemodynamics, and morphology after liver transplant. Physiological effect of therapy.

    PubMed Central

    Millikan, W J; Henderson, J M; Stewart, M T; Warren, W D; Marsh, J W; Galloway, J R; Jennings, H; Kawasaki, S; Dodson, T F; Perlino, C A

    1989-01-01

    Orthotopic liver transplantation (OLT) has become standard therapy for patients with acute hepatic necrosis and end-stage liver disease. This study measured change in hepatic function (galactose elimination capacity [GEC]), liver blood flow (low dose galactose clearance: flow), hepatic volume (CT scan; volume) and morphology after OLT. The aim was to measure the physiologic response after OLT and compare this response with that after selective shunt (SS) and sclerotherapy (ES) to determine which patients should receive specific therapy. Between January 1987 and November 1988, 37 patients underwent OLT. Operative mortality was 18%, which was similar to that of SS in Child's C cirrhotics. GEC and volume were less in transplant patients than in cirrhotics treated with SS or ES. GEC, flow, and volume normalized after OLT; GEC was preserved after ES and SS, but volume decreased. Three preoperative patterns were observed that can aid in selection of OLT candidates. Patients with chronic cirrhosis (chronic active hepatitis; cryptogenic) need OLT when GEC is less than or equal to 225 mg/min and volume is less than or equal to 50% normal. Patients with Budd-Chiari Syndrome require OLT if cirrhosis has evolved. Patients with sclerosing cholangitis and primary biliary cirrhosis qualify for transplants when complications of the portal hypertensive syndrome develop. The studies can also direct therapy for ES failures. Selective shunt is indicated in those patients with stable disease whose GEC is greater than or equal to 300 mg/min and liver volume is greater than 75% normal; OLT is indicated for cirrhotics with GEC that is less than 225 mg/min and liver volume that is less than 50% predicted normal. PMID:2650642

  12. A pivotal role of Rho GTPase in the regulation of morphology and function of dendritic cells.

    PubMed

    Kobayashi, M; Azuma, E; Ido, M; Hirayama, M; Jiang, Q; Iwamoto, S; Kumamoto, T; Yamamoto, H; Sakurai, M; Komada, Y

    2001-10-01

    Dendritic cell (DC) is the most potent activator of CD4+ T cells and has unique dendrites and veils. To explore the function of Rho in DC, exoenzyme C3 from Clostridium botulinum was used as a specific inhibitor of Rho. Treatment of DC with C3 (DC/C3) resulted in profound morphological changes by losing dendrites and emerging of shrunk membrane processes that were in parallel with marked reduction of polymerized actin in the marginal area. Inactivation of Rho-associated coiled coil-containing kinase (p160ROCK) by a specific ROCK inhibitor Y-27632 also led to disappearance of dendrites of DC with retaining large membrane expansions. In scanning electron microscopy, untreated DCs interacted with CD4+ T cells more efficiently than DC/C3. Conjugate formation assay showed that the number of DCs associated with CD4+ T cells was 2-fold higher in untreated DCs than that of DC/C3. Alloantigen-presenting capacity of DC/C3 was significantly suppressed in a dose-dependent manner. Because C3 treatment did not affect the surface expression of HLA, costimulatory, and adhesion molecules of DC, we examined cytokine production of DC and naive CD4+ T cells to further elucidate the inhibitory mechanism of MLR. Unexpectedly, DC/C3 increased IL-12 production after LPS stimulation. Naive CD4+ T cells cocultured with DC/C3 produced the increased percentage of IFN-gamma-producing cells, whereas the percentage of IL-2-producing T cells was decreased. These results demonstrate that Rho GTPase in DC controls both characteristic shape and immunogenic capacity. PMID:11564770

  13. Skeletal muscle morphology and contractile function in relation to muscle denervation in diabetic neuropathy

    PubMed Central

    Major, Brendan; Kimpinski, Kurt; Doherty, Timothy J.; Rice, Charles L.

    2013-01-01

    The objective of the study was to assess the effects of diabetic polyneuropathy (DPN) on muscle contractile properties in humans, and how these changes are related to alterations in muscle morphology and denervation. Patients with DPN (n = 12) were compared with age- and sex-matched controls (n = 12). Evoked and voluntary contractile properties, including stimulated twitch responses and maximal voluntary contractions, of the dorsiflexor muscles were assessed using an isometric ankle dynamometer. Motor unit number estimates (MUNE) of the tibialis anterior (TA) were performed via quantitative electromyography and decomposition-enhanced spike-triggered averaging. Peak tibialis anterior (TA) cross-sectional area (CSA; cm2), and relative proportion of contractile to noncontractile tissue (%) was determined from magnetic resonance images. Patients with DPN demonstrated decreased strength (−35%) and slower (−45%) dorsiflexion contractile properties for both evoked and voluntary contractions (P < 0.05). These findings were not accounted for by differences in voluntary activation (P > 0.05) or antagonist coactivation (P > 0.05). Additionally, patients with DPN were weaker when strength was normalized to TA total CSA (−30%; P < 0.05) or contractile tissue CSA (−26%; P < 0.05). In the DPN patient group, TA MUNEs were negatively related to both % noncontractile tissue (P < 0.05; r = 0.72) and twitch half-relaxation time (P < 0.05; r = 0.60), whereas no relationships were found between these variables in controls (P > 0.05). We conclude that patients with DPN demonstrated reduced strength and muscle quality as well as contractile slowing. This process may contribute to muscle power loss and functional impairments reported in patients with DPN, beyond the loss of strength commonly observed. PMID:24356519

  14. 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. PMID:21290417

  15. 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.

  16. 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.

  17. A new approach to the learning of dental morphology, function, and esthetics: the "2D-3D-4D" concept.

    PubMed

    Magne, Pascal

    2015-01-01

    A concept is proposed for an approach to the learning of dental morphology and occlusion. Dental morphology, function, and esthetics should reflect a fundamental driving force, that is, the faithful emulation of the natural dentition's structural (functional, mechanical) and esthetic properties. The innovative part of the proposed approach is the emphasis on visual arts and the 2D-3D-4D aspect that starts with drawing (2D/3D) and continues with partial wax-up exercises that are followed by labial waxups and, finally, full wax-ups using innovative technical aids (electric waxers, prefabricated wax patterns, etc). Finally, the concept of layers (4D) and the histoanatomy of enamel/dentin and optical depth are taught through the realization of layering exercises (advanced acrylic mock-ups and composite resin restorations). All these techniques and materials are not only used to teach morphology and occlusion, but also constitute essential tools that will be of significant use for the student dentists and dental technologists in their future daily practice. The clinical significance of the presented methodology should allow not only students but also practicing dentists and dental technologists to help their youngest collaborators to develop a deep sense of morphology, function, and esthetics.

  18. 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

  19. 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

  20. 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.

  1. 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.

  2. 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.

  3. Open and closed evolutionary paths for drastic morphological changes, involving serial gene duplication, sub-functionalization, and selection.

    PubMed

    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

  4. 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

  5. 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

  6. The spinning apparatus of webspinners--functional-morphology, morphometrics and spinning behaviour.

    PubMed

    Büsse, Sebastian; Hörnschemeyer, Thomas; Hohu, Kyle; McMillan, David; Edgerly, Janice S

    2015-05-07

    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.

  7. 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.

  8. Morphological Evolution of Electrochemically Plated/Stripped Lithium Microstructures Investigated by Synchrotron X-ray Phase Contrast Tomography.

    PubMed

    Sun, Fu; Zielke, Lukas; Markötter, Henning; Hilger, André; Zhou, Dong; Moroni, Riko; Zengerle, Roland; Thiele, Simon; Banhart, John; Manke, Ingo

    2016-08-23

    Due to its low redox potential and high theoretical specific capacity, Li metal has drawn worldwide research attention because of its potential use in next-generation battery technologies such as Li-S and Li-O2. Unfortunately, uncontrollable growth of Li microstructures (LmSs, e.g., dendrites, fibers) during electrochemical Li stripping/plating has prevented their practical commercialization. Despite various strategies proposed to mitigate LmS nucleation and/or block its growth, a fundamental understanding of the underlying evolution mechanisms remains elusive. Herein, synchrotron in-line phase contrast X-ray tomography was employed to investigate the morphological evolution of electrochemically deposited/dissolved LmSs nondestructively. We present a 3D characterization of electrochemically stripped Li electrodes with regard to electrochemically plated LmSs. We clarify fundamentally the origin of the porous lithium interface growing into Li electrodes. Moreover, cleavage of the separator caused by growing LmS was experimentally observed and visualized in 3D. Our systematic investigation provides fundamental insights into LmS evolution and enables us to understand the evolution mechanisms in Li electrodes more profoundly. PMID:27463258

  9. 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.

  10. Diblock copolymers of polystyrene-b-poly(1,3-cyclohexadiene) exhibiting unique three-phase microdomain morphologies

    DOE PAGES

    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 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

  11. 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.

  12. 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.

  13. The evaluation of the impact of titania nanotube covers morphology and crystal phase on their biological properties.

    PubMed

    Lewandowska, Żaneta; Piszczek, Piotr; Radtke, Aleksandra; Jędrzejewski, Tomasz; Kozak, Wiesław; Sadowska, Beata

    2015-04-01

    The highly ordered titanium dioxide nanotube coatings were produced under various electrochemical conditions on the surface of titanium foil. The anodization voltage changes proved to be a main factor which directly affects the nanotube morphology, structure, and wettability. Moreover we have noticed a significant dependence between the size and crystallinity of TiO2 layers and the adhesion/proliferation of fibroblasts and antimicrobial properties. Cellular functionality were investigated for up to 3 days in culture using a cell viability assay and scanning electron microscopy. In general, results of our studies revealed that fibroblasts adhesion, proliferation, and differentiation on the titania nanotube coatings is clearly higher than on the surface of the pure titanium foil. The formation of crystallic islands in the nanotubes structure induced a significant acceleration in the growth rate of fibroblasts cells by as much as ~200 %. Additionally, some types of TiO2 layers revealed the ability to the reduce of the staphylococcal aggregates/biofilm formation. The nanotube coatings formed during the anodization process using the voltage 4 V proved to be the stronger S. aureus aggregates/biofilm inhibitor in comparison to the uncovered titanium substrate. That accelerated eukaryotic cell growth and anti-biofilm activity is believed to be advantageous for faster cure of dental and orthopaedic patients, and also for a variety of biomedical diagnostic and therapeutic applications. The highly ordered titanium dioxide nanotube coatings were produced under various electrochemical conditions on the surface of titanium foil. The anodization voltage changes proved to be a main factor which directly affects the nanotube morphology, structure, and wettability. Moreover we have noticed a significant dependence between the size and crystallinity of TiO2 layers and the adhesion/proliferation of fibroblasts and antimicrobial properties.

  14. The evaluation of the impact of titania nanotube covers morphology and crystal phase on their biological properties.

    PubMed

    Lewandowska, Żaneta; Piszczek, Piotr; Radtke, Aleksandra; Jędrzejewski, Tomasz; Kozak, Wiesław; Sadowska, Beata

    2015-04-01

    The highly ordered titanium dioxide nanotube coatings were produced under various electrochemical conditions on the surface of titanium foil. The anodization voltage changes proved to be a main factor which directly affects the nanotube morphology, structure, and wettability. Moreover we have noticed a significant dependence between the size and crystallinity of TiO2 layers and the adhesion/proliferation of fibroblasts and antimicrobial properties. Cellular functionality were investigated for up to 3 days in culture using a cell viability assay and scanning electron microscopy. In general, results of our studies revealed that fibroblasts adhesion, proliferation, and differentiation on the titania nanotube coatings is clearly higher than on the surface of the pure titanium foil. The formation of crystallic islands in the nanotubes structure induced a significant acceleration in the growth rate of fibroblasts cells by as much as ~200 %. Additionally, some types of TiO2 layers revealed the ability to the reduce of the staphylococcal aggregates/biofilm formation. The nanotube coatings formed during the anodization process using the voltage 4 V proved to be the stronger S. aureus aggregates/biofilm inhibitor in comparison to the uncovered titanium substrate. That accelerated eukaryotic cell growth and anti-biofilm activity is believed to be advantageous for faster cure of dental and orthopaedic patients, and also for a variety of biomedical diagnostic and therapeutic applications. The highly ordered titanium dioxide nanotube coatings were produced under various electrochemical conditions on the surface of titanium foil. The anodization voltage changes proved to be a main factor which directly affects the nanotube morphology, structure, and wettability. Moreover we have noticed a significant dependence between the size and crystallinity of TiO2 layers and the adhesion/proliferation of fibroblasts and antimicrobial properties. PMID:25791457

  15. Classical cardiovascular disease risk factors associate with vascular function and morphology in rheumatoid arthritis: a six-year prospective study

    PubMed Central

    2013-01-01

    Introduction Patients with rheumatoid arthritis (RA) are at an increased risk for cardiovascular disease (CVD). An early manifestation of CVD is endothelial dysfunction which can lead to functional and morphological vascular abnormalities. Classical CVD risk factors and inflammation are both implicated in causing endothelial dysfunction in RA. The objective of the present study was to examine the effect of baseline inflammation, cumulative inflammation, and classical CVD risk factors on the vasculature following a six-year follow-up period. Methods A total of 201 RA patients (155 females, median age (25th to 75th percentile): 61 years (53 to 67)) were examined at baseline (2006) for presence of classical CVD risk factors and determination of inflammation using C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR). At follow-up (2012) patients underwent assessments of microvascular and macrovascular endothelium-dependent and endothelium-independent function, along with assessment of carotid atherosclerosis. The CRP and ESR were recorded from the baseline study visit to the follow-up visit for each patient to calculate cumulative inflammatory burden. Results Classical CVD risk factors, but not RA disease-related inflammation, predicted microvascular endothelium-dependent and endothelium-independent function, macrovascular endothelium-independent function and carotid atherosclerosis. These findings were similar in a sub-group of patients free from CVD, and not receiving non-steroidal anti-inflammatory drugs, cyclooxygenase 2 inhibitors or biologics. Cumulative inflammation was not associated with microvascular and macrovascular endothelial function, but a weak association was apparent between area under the curve for CRP and carotid atherosclerosis. Conclusions Classical CVD risk factors may be better long-term predictors of vascular function and morphology than systemic disease-related inflammation in patients with RA. Further studies are needed to

  16. 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

  17. Nanoscale Morphology of PTB7 Based Organic Photovoltaics as a Function of Fullerene Size

    NASA Astrophysics Data System (ADS)

    Roehling, John D.; Baran, Derya; Sit, Joseph; Kassar, Thaer; Ameri, Tayebeh; Unruh, Tobias; Brabec, Christoph J.; Moulé, Adam J.

    2016-08-01

    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.

  18. Nanoscale Morphology of PTB7 Based Organic Photovoltaics as a Function of Fullerene Size.

    PubMed

    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

  19. 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

  20. Nanoscale Morphology of PTB7 Based Organic Photovoltaics as a Function of Fullerene Size.

    PubMed

    Roehling, John D; Baran, Derya; Sit, Joseph; Kassar, Thaer; Ameri, Tayebeh; Unruh, Tobias; Brabec, Christoph J; Moulé, Adam J

    2016-08-08

    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.

  1. 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. PMID:23907790

  2. 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.

  3. 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

  4. One-pot synthesis of CuInS2 nanocrystals using different anions to engineer their morphology and crystal phase.

    PubMed

    Tang, Aiwei; Hu, Zunlan; Yin, Zhe; Ye, Haihang; Yang, Chunhe; Teng, Feng

    2015-05-21

    A simple one-pot colloidal method has been described to engineer ternary CuInS2 nanocrystals with different crystal phases and morphologies, in which dodecanethiol is chosen as the sulfur source and the capping ligands. By a careful choice of the anions in the metal precursors and manipulation of the reaction conditions including the reactant molar ratios and the reaction temperature, CuInS2 nanocrystals with chalcopyrite, zincblende and wurtzite phases have been successfully synthesized. The type of anion in the metal precursors has been found to be essential for determining the crystal phase and morphology of the as-obtained CuInS2 nanocrystals. In particular, the presence of Cl(-) ions plays an important role in the formation of CuInS2 nanoplates with a wurtzite-zincblende polytypism structure. In addition, the molar ratios of Cu to In precursors have a significant effect on the crystal phase and morphology, and the intermediate Cu2S-CuInS2 heteronanostructures are formed which are critical for the anisotropic growth of CuInS2 nanocrystals. Furthermore, the optical absorption results of the as-obtained CuInS2 nanocrystals exhibit a strong dependence on the crystal phase and size.

  5. 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.

  6. 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

  7. 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.

  8. 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. PMID:27254450

  9. 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.

  10. 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.

  11. 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.

  12. Spatio-orientationally organized polymer microstructures obtained on self-assembled pattern-forming states of liquid crystals: Morphology, phase separation, and potential applications

    NASA Astrophysics Data System (ADS)

    Kang, Shin-Woong

    The main objective of the dissertation is to develop and exploit a novel technique for imparting multidimensional spatial and orientational order into polymer networks. This approach is based on the use of pattern-forming states of liquid crystals as templates for the network formation. To demonstrate the feasibility and flexibility of this concept, we describe various pattern-forming states observed from ordinary cholesteric and nematic/cholesteric dual-frequency liquid crystals. We present a variety of polymer microstuctures templated on those pattern-forming states. This clearly demonstrates the feasibility and flexibility of templating both orientational and positional order of host pattern-forming states into polymer network. We investigated possible driving forces behind this templating effect of LC pattern-forming states. These include effects of both spatial variations of UV intensity and gradients in elastic distortion caused by the spatial modulation of director field. The effects of the two mechanisms are separated through a series of experiments, including polarization-selective photopolymerization, FTIR imaging of the monomer distribution prior to UV-exposure and initiation of the photoreaction, the effect of temperature on the templated morphology, and the use of a thermal reactive monomer to remove the effect of possible optical inhomogeneities. The model derives from the concept of director gradient templating, whereby monomer phase separation is driven by a competition between reduction in elastic energy when monomer replaces liquid crystal in more (or less) distorted regions of the molecular director, and a consequent decrease in the entropy of mixing of the two species. Another emphasis of this dissertation is to study the control over the network morphology in the "third" dimension---perpendicular to UV wavefront---by relatively simple means of selecting the wavelength of UV light used in photopolymerization to be inside or outside a carefully

  13. From the Weyl quantization of a particle on the circle to number-phase Wigner functions

    NASA Astrophysics Data System (ADS)

    Przanowski, Maciej; Brzykcy, Przemysław; Tosiek, Jaromir

    2014-12-01

    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' 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.

  14. 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.

  15. 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. PMID:16244465

  16. RAFT aqueous dispersion polymerization yields poly(ethylene glycol)-based diblock copolymer nano-objects with predictable single phase morphologies.

    PubMed

    Warren, Nicholas J; Mykhaylyk, Oleksandr O; Mahmood, Daniel; Ryan, Anthony J; Armes, Steven P

    2014-01-22

    A poly(ethylene glycol) (PEG) macromolecular chain transfer agent (macro-CTA) is prepared in high yield (>95%) with 97% dithiobenzoate chain-end functionality in a three-step synthesis starting from a monohydroxy PEG113 precursor. This PEG113-dithiobenzoate is then used for the reversible addition-fragmentation chain transfer (RAFT) aqueous dispersion polymerization of 2-hydroxypropyl methacrylate (HPMA). Polymerizations conducted under optimized conditions at 50 °C led to high conversions as judged by (1)H NMR spectroscopy and relatively low diblock copolymer polydispersities (M(w)/M(n) < 1.25) as judged by GPC. The latter technique also indicated good blocking efficiencies, since there was minimal PEG113 macro-CTA contamination. Systematic variation of the mean degree of polymerization of the core-forming PHPMA block allowed PEG113-PHPMA(x) diblock copolymer spheres, worms, or vesicles to be prepared at up to 17.5% w/w solids, as judged by dynamic light scattering and transmission electron microscopy studies. Small-angle X-ray scattering (SAXS) analysis revealed that more exotic oligolamellar vesicles were observed at 20% w/w solids when targeting highly asymmetric diblock compositions. Detailed analysis of SAXS curves indicated that the mean number of membranes per oligolamellar vesicle is approximately three. A PEG113-PHPMA(x) phase diagram was constructed to enable the reproducible targeting of pure phases, as opposed to mixed morphologies (e.g., spheres plus worms or worms plus vesicles). This new RAFT PISA formulation is expected to be important for the rational and efficient synthesis of a wide range of biocompatible, thermo-responsive PEGylated diblock copolymer nano-objects for various biomedical applications. PMID:24400622

  17. 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.

  18. 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.

  19. Carbonic anhydrase related protein 8 mutation results in aberrant synaptic morphology and excitatory synaptic function in the cerebellum

    PubMed Central

    Hirasawa, Michiru; Xu, Xinjie; Trask, Robert B.; Maddatu, Terry P.; Johnson, Britt A; Naggert, Jürgen K.; Nishina, Patsy M.; Ikeda, Akihiro

    2007-01-01

    Carbonic anhydrase related protein 8 (Car8) is known to be abundantly expressed in Purkinje cells (PCs), and its genetic mutation causes a motor coordination defect. To determine the underlying mechanism, we analyzed the mouse cerebellum carrying a Car8 mutation. Electrophysiological analysis showed that spontaneous excitatory transmission was largely diminished while paired pulse ratio at parallel fiber-PC synapses was comparable to wild-type, suggesting functional synapses have normal release probability but the number of functional synapses may be lower in mutants. Light microscopic study revealed an abnormal extension of climbing fibers to the distal PC dendrites. At ultrastructural level, we found numerous PC spines not forming synapses primarily in distal dendrites and occasionally multiple spines contacting a single varicosity. These abnormalities of parallel fiber-PC synapses may underlie the functional defect in excitatory transmission. Thus, Car8 plays a critical role in synaptogenesis and/or maintenance of proper synaptic morphology and function in the cerebellum. PMID:17376701

  20. Avian acute phase protein ovotransferrin modulates phagocyte function

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Acute phase proteins (APP) are serum proteins elevated in response to a variety of physiological injuries including infection and inflammation. These pathogen nonspecific proteins are predominantly synthesized in the liver and serve as a humoral component of innate immunity by way of recognizing and...

  1. A functional and morphological approach to evaluate the vertical migration of estuarine intertidal nematodes during a tidal cycle

    NASA Astrophysics Data System (ADS)

    Brustolin, M. C.; Thomas, M. C.; Lana, P. C.

    2013-03-01

    We tested herein the hypothesis that exposure time significantly contributes to the vertical distribution profile of nematodes during a tidal cycle as a function of distinct feeding and locomotion behaviors, conditioned by body morphology. We showed that the vertical distribution profile of the slender with filiform tail, numerically dominant Terschellingia longicaudata is in fact significantly correlated with sediment changes induced by tidal variation. Conversely, none of the other nematode species showed unequivocal evidence of vertical migration. Horizontal spatial heterogeneity also influenced the vertical distribution of nematode associations, probably as a response to varying temperature and desiccation levels at the sediment surface. The resulting vertical profiles for individual or species groups are a trade-off among locomotory and feeding strategies and concordant morphological adaptations.

  2. 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.

  3. 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.

  4. 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. PMID:27593268

  5. Two types of local interneurons are distinguished by morphology, intrinsic membrane properties, and functional connectivity in the moth antennal lobe.

    PubMed

    Tabuchi, Masashi; Dong, Li; Inoue, Shigeki; Namiki, Shigehiro; Sakurai, Takeshi; Nakatani, Kei; Kanzaki, Ryohei

    2015-11-01

    Neurons in the silkmoth antennal lobe (AL) are well characterized in terms of their morphology and odor-evoked firing activity. However, their intrinsic electrical properties including voltage-gated ionic currents and synaptic connectivity remain unclear. To address this, whole cell current- and voltage-clamp recordings were made from second-order projection neurons (PNs) and two morphological types of local interneurons (LNs) in the silkmoth AL. The two morphological types of LNs exhibited distinct physiological properties. One morphological type of LN showed a spiking response with a voltage-gated sodium channel gene expression, whereas the other type of LN was nonspiking without a voltage-gated sodium channel gene expression. Voltage-clamp experiments also revealed that both of two types of LNs as well as PNs possessed two types of voltage-gated potassium channels and calcium channels. In dual whole cell recordings of spiking LNs and PNs, activation of the PN elicited depolarization responses in the paired spiking LN, whereas activation of the spiking LN induced no substantial responses in the paired PN. However, simultaneous recording of a nonspiking LN and a PN showed that activation of the nonspiking LN induced hyperpolarization responses in the PN. We also observed bidirectional synaptic transmission via both chemical and electrical coupling in the pairs of spiking LNs. Thus our results indicate that there were two distinct types of LNs in the silkmoth AL, and their functional connectivity to PNs was substantially different. We propose distinct functional roles for these two different types of LNs in shaping odor-evoked firing activity in PNs.

  6. 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

  7. 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.

  8. 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.

  9. Distribution and morphology of nitrergic neurons across functional domains of the rat primary somatosensory cortex

    PubMed Central

    Nogueira-Campos, Anaelli A.; Finamore, Deborah M.; Imbiriba, Luis A.; Houzel, Jean C.; Franca, João G.

    2012-01-01

    The rat primary somatosensory cortex (S1) is remarkable for its conspicuous vertical compartmentalization in barrels and septal columns, which are additionally stratified in horizontal layers. Whereas excitatory neurons from each of these compartments perform different types of processing, the role of interneurons is much less clear. Among the numerous types of GABAergic interneurons, those producing nitric oxide (NO) are especially puzzling, since this gaseous messenger can modulate neural activity, synaptic plasticity, and neurovascular coupling. We used a quantitative morphological approach to investigate whether nitrergic interneurons, which might therefore be considered both as NO volume diffusers and as elements of local circuitry, display features that could relate to barrel cortex architecture. In fixed brain sections, nitrergic interneurons can be revealed by histochemical processing for NADPH-diaphorase (NADPHd). Here, the dendritic arbors of nitrergic neurons from different compartments of area S1 were 3D reconstructed from serial 200 μm thick sections, using 100x objective and the Neurolucida system. Standard morphological parameters were extracted for all individual arbors and compared across columns and layers. Wedge analysis was used to compute dendritic orientation indices. Supragranular (SG) layers displayed the highest density of nitrergic neurons, whereas layer IV contained nitrergic neurons with largest soma area. The highest nitrergic neuronal density was found in septa, where dendrites were previously characterized as more extense and ramified than in barrels. Dendritic arbors were not confined to the boundaries of the column nor layer of their respective soma, being mostly double-tufted and vertically oriented, except in SG layers. These data strongly suggest that nitrergic interneurons adapt their morphology to the dynamics of processing performed by cortical compartments. PMID:23133407

  10. 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.

  11. Role of the FUL-SHP network in the evolution of fruit morphology and function.

    PubMed

    Ferrándiz, Cristina; Fourquin, Chloé

    2014-08-01

    Arabidopsis research in the last decade has started to unravel the genetic networks directing gynoecium and fruit patterning in this model species. Only recently, the work from several groups has also started to address the conservation of these networks in a wide number of species with very different fruit morphologies, and we are now beginning to understand how they might have evolved. This review summarizes recent advances in this field, focusing mainly on MADS-box genes with a well-known role in dehiscence zone development, while also discussing how these studies may contribute to expand our views on fruit evolution.

  12. Ultracytochemical evidence of Golgi functions in microvesicles at all phases of cell cycle in Saccharomyces cerevisiae.

    PubMed

    Vorísek, J

    1995-01-01

    The topical question of Golgi compartment identity in the ascomycetous yeast Saccharomyces cerevisiae is illustrated by a multiple ultracytochemical approach. For this eucaryotic single-cell organism the established scheme of secretory transport via a cascade of cisternae housing different functions of Golgi apparatus has been deduced principally of genetic and molecular analyses ex situ and confirms the mammalian secretion scheme. Nevertheless, ultracytochemical in situ localizations of enzyme activities engaged in secretion represented evidence for localization of important steps of secretory glycoprotein maturation in two morphologically distinct populations of transport microvesicles formed from endoplasmic reticulum and Golgi cisternae. Both types of microvesicles function in exocytosis or transport into lysosomal vacuoles and have identical charge. However, their presence differs in interphase and in budding cells of S. cerevisiae. Smooth, larger membrane bound microvesicles are conspicuous at the onset of budding and at construction of scars, while the coated, smaller microvesicles of globular ultrastructure are present constitutively, throughout the cell cycle. Because the established model of the yeast secretory path considers only the part of the budding phase preceding the onset of mitosis, an alternative scheme for the cellular mechanism of glycoprotein secretion in S. cerevisiae that distinguishes interphase and budding yeast, has been established. The lumen of microvesicles contains proteases catalysing maturation of the mating pheromone alpha-factor (yscIV, yscF), vacuolar protease yscY, alkaline phosphohydrolase, polyphosphorylated components of the bud scar and glycoproteins. The in situ approach also reveals a minimum level of alpha-factor precursor processing proteolytic activity at the budding phase of cells, a transient presence of polyphosphorylated compounds in the bud scars and their transport by microvesicles. Ultracytochemical reactions

  13. 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.

  14. Functional differences between two morphologically distinct cell subpopulations within a human colorectal carcinoma cell line.

    PubMed

    Solimene, A C; Carneiro, C R; Melati, I; Lopes, J D

    2001-05-01

    The LISP-I human colorectal adenocarcinoma cell line was isolated from a hepatic metastasis at the Ludwig Institute, São Paulo, SP, Brazil. The objective of the present study was to isolate morphologically different subpopulations within the LISP-I cell line, and characterize some of their behavioral aspects such as adhesion to and migration towards extracellular matrix components, expression of intercellular adhesion molecules and tumorigenicity in vitro. Once isolated, the subpopulations were submitted to adhesion and migration assays on laminin and fibronectin (crucial proteins to invasion and metastasis), as well as to anchorage-independent growth. Two morphologically different subpopulations were isolated: LISP-A10 and LISP-E11. LISP-A10 presents a differentiated epithelial pattern, and LISP-E11 is fibroblastoid, suggesting a poorly differentiated pattern. LISP-A10 expressed the two intercellular adhesion molecules tested, carcinoembryonic antigen (CEA) and desmoglein, while LISP-E11 expressed only low amounts of CEA. On the other hand, adhesion to laminin and fibronectin as well as migration towards these extracellular matrix proteins were higher in LISP-E11, as expected from its poorly differentiated phenotype. Both subpopulations showed anchorage-independent growth on a semi-solid substrate. These results raise the possibility that the heterogeneity found in the LISP-I cell line, which might have contributed to its ability to metastasize, was due to at least two different subpopulations herein identified. PMID:11323753

  15. A comparative physicochemical, morphological and magnetic study of silane-functionalized superparamagnetic iron oxide nanoparticles prepared by alkaline coprecipitation.

    PubMed

    Mireles, Laura-Karina; Sacher, Edward; Yahia, L'Hocine; Laurent, Sophie; Stanicki, Dimitri

    2016-06-01

    The characterization of synthetic superparamagnetic iron oxide nanoparticle (SPION) surfaces prior to functionalization is an essential step in the prediction of their successful functionalization, and in uncovering issues that may influence their selection as magnetically targeted drug delivery vehicles (prodrugs). Here, three differently functionalized magnetite (Fe3O4) SPIONs are considered. All were identically prepared by the alkaline coprecipitation of Fe(2+) and Fe(3+) salts. We use X-ray photoelectron spectroscopy, electron microscopy, time-of-flight SIMS, FTIR spectroscopy and magnetic measurements to characterize their chemical, morphological and magnetic properties, in order to aid in determining how their surfaces differ from those prepared by Fe(CO)5 decomposition, which we have already studied, and in assessing their potential use as drug delivery carriers.

  16. Systematic Surface Phase Transition of Ag Thin Films by Iodine Functionalization at Room Temperature: Evolution of Optoelectronic and Texture Properties.

    PubMed

    Bashouti, Muhammad Y; Talebi, Razieh; Kassar, Thaer; Nahal, Arashmid; Ristein, Jürgen; Unruh, Tobias; Christiansen, Silke H

    2016-01-01

    We show a simple room temperature surface functionalization approach using iodine vapour to control a surface phase transition from cubic silver (Ag) of thin films into wurtzite silver-iodid (β-AgI) films. A combination of surface characterization techniques (optical, electronical and structural characterization) reveal distinct physical properties of the new surface phase. We discuss the AgI thin film formation dynamics and related transformation of physical properties by determining the work-function, dielectric constant and pyroelectric behavior together with morphological and structural thin film properties such as layer thickness, grain structure and texture formation. Notable results are: (i) a remarkable increase of the work-function (by 0.9 eV) of the Ag thin layer after short a iodine exposure time (≤60 s), with simultaneous increase of the thin film transparency (by two orders of magnitude), (ii) pinning of the Fermi level at the valance band maximum upon iodine functionalization, (iii) 84% of all crystallites grain were aligned as a result of the evolution of an internal electric field. Realizing a nano-scale layer stack composed of a dielectric AgI layer on top of a metallic thin Ag layer with such a simple method has some technological implications e.g. to realize optical elements such as planar optical waveguides. PMID:26899434

  17. Systematic Surface Phase Transition of Ag Thin Films by Iodine Functionalization at Room Temperature: Evolution of Optoelectronic and Texture Properties

    PubMed Central

    Bashouti, Muhammad Y.; Talebi, Razieh; Kassar, Thaer; Nahal, Arashmid; Ristein, Jürgen; Unruh, Tobias; Christiansen, Silke H.

    2016-01-01

    We show a simple room temperature surface functionalization approach using iodine vapour to control a surface phase transition from cubic silver (Ag) of thin films into wurtzite silver-iodid (β-AgI) films. A combination of surface characterization techniques (optical, electronical and structural characterization) reveal distinct physical properties of the new surface phase. We discuss the AgI thin film formation dynamics and related transformation of physical properties by determining the work-function, dielectric constant and pyroelectric behavior together with morphological and structural thin film properties such as layer thickness, grain structure and texture formation. Notable results are: (i) a remarkable increase of the work-function (by 0.9 eV) of the Ag thin layer after short a iodine exposure time (≤60 s), with simultaneous increase of the thin film transparency (by two orders of magnitude), (ii) pinning of the Fermi level at the valance band maximum upon iodine functionalization, (iii) 84% of all crystallites grain were aligned as a result of the evolution of an internal electric field. Realizing a nano-scale layer stack composed of a dielectric AgI layer on top of a metallic thin Ag layer with such a simple method has some technological implications e.g. to realize optical elements such as planar optical waveguides. PMID:26899434

  18. Systematic Surface Phase Transition of Ag Thin Films by Iodine Functionalization at Room Temperature: Evolution of Optoelectronic and Texture Properties

    NASA Astrophysics Data System (ADS)

    Bashouti, Muhammad Y.; Talebi, Razieh; Kassar, Thaer; Nahal, Arashmid; Ristein, Jürgen; Unruh, Tobias; Christiansen, Silke H.

    2016-02-01

    We show a simple room temperature surface functionalization approach using iodine vapour to control a surface phase transition from cubic silver (Ag) of thin films into wurtzite silver-iodid (β-AgI) films. A combination of surface characterization techniques (optical, electronical and structural characterization) reveal distinct physical properties of the new surface phase. We discuss the AgI thin film formation dynamics and related transformation of physical properties by determining the work-function, dielectric constant and pyroelectric behavior together with morphological and structural thin film properties such as layer thickness, grain structure and texture formation. Notable results are: (i) a remarkable increase of the work-function (by 0.9 eV) of the Ag thin layer after short a iodine exposure time (≤60 s), with simultaneous increase of the thin film transparency (by two orders of magnitude), (ii) pinning of the Fermi level at the valance band maximum upon iodine functionalization, (iii) 84% of all crystallites grain were aligned as a result of the evolution of an internal electric field. Realizing a nano-scale layer stack composed of a dielectric AgI layer on top of a metallic thin Ag layer with such a simple method has some technological implications e.g. to realize optical elements such as planar optical waveguides.

  19. 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.

  20. Fossil Plotopterid Seabirds from the Eo-Oligocene of the Olympic Peninsula (Washington State, USA): Descriptions and Functional Morphology

    PubMed Central

    Dyke, Gareth J.; Wang, Xia; Habib, Michael B.

    2011-01-01

    The plotopterids (Aves, Plotopteridae) were a group of extinct wing-propelled marine birds that are known from Paleogene-aged sediments (Eocene to Miocene), mostly around the Pacific Rim (especially Japan and the northwest coast of North America). While these birds exhibit a strikingly similar wing morphology to penguins (Spheniscidae), they also share derived characters with pelecaniform birds that are absent in penguins and exhibit apparently superficial similarities with auks (Alcidae: Charadriiformes). Despite quite an abundant fossil record, these birds have been little studied, and in particular their functional morphology remains little understood. Here we present osteological overviews of specimens from the northwest coast of Washington state (USA). We give an amended diagnosis for the well-represented North American genus, Tonsala Olson, 1980, describe a new large species, and examine the functional morphology of plotopterids showing that the ratio of humeral strength to femoral strength is quite low in one well-represented species Tonsala buchanani sp.nov., relative to both extant penguins and alcids. While the femoral strength of Tonsala buchanani is ‘penguin-grade’, its humeral strength is more ‘alcid-grade’. These results have implications for understanding the mode-of-locomotion of these extinct marine birds. Although not related to Spheniscidae, our descriptions and functional results suggest that Tonsala buchanani sustained similar loads in walking, but slightly lower humeral loads during swimming, than a modern penguin. This suggests a swimming mode that is more similar to living alcids, than to the highly-specialised locomotor strategy of living and fossil penguins. PMID:22065992

  1. Fossil plotopterid seabirds from the Eo-Oligocene of the Olympic Peninsula (Washington State, USA): descriptions and functional morphology.

    PubMed

    Dyke, Gareth J; Wang, Xia; Habib, Michael B

    2011-01-01

    The plotopterids (Aves, Plotopteridae) were a group of extinct wing-propelled marine birds that are known from Paleogene-aged sediments (Eocene to Miocene), mostly around the Pacific Rim (especially Japan and the northwest coast of North America). While these birds exhibit a strikingly similar wing morphology to penguins (Spheniscidae), they also share derived characters with pelecaniform birds that are absent in penguins and exhibit apparently superficial similarities with auks (Alcidae: Charadriiformes). Despite quite an abundant fossil record, these birds have been little studied, and in particular their functional morphology remains little understood. Here we present osteological overviews of specimens from the northwest coast of Washington state (USA). We give an amended diagnosis for the well-represented North American genus, Tonsala Olson, 1980, describe a new large species, and examine the functional morphology of plotopterids showing that the ratio of humeral strength to femoral strength is quite low in one well-represented species Tonsala buchanani sp.nov., relative to both extant penguins and alcids. While the femoral strength of Tonsala buchanani is 'penguin-grade', its humeral strength is more 'alcid-grade'. These results have implications for understanding the mode-of-locomotion of these extinct marine birds. Although not related to Spheniscidae, our descriptions and functional results suggest that Tonsala buchanani sustained similar loads in walking, but slightly lower humeral loads during swimming, than a modern penguin. This suggests a swimming mode that is more similar to living alcids, than to the highly-specialised locomotor strategy of living and fossil penguins. PMID:22065992

  2. Effect of green tea (Camellia sinensis L.) extract on morphological and functional changes in adult male gonads of albino rats.

    PubMed

    Chandra, Amar K; Choudhury, Shyamosree Roy; De, Neela; Sarkar, Mahitosh

    2011-09-01

    Green tea, prepared from the steamed and dried leaves of the shrub Camellia sinensis, is known for its antioxidant and anti-carcinogenic effects. However, its effects on male gonadal functions have not been explored adequately and the present investigation has been undertaken to evaluate the effect of green tea extract on gonads of adult male albino rats. Results of in vivo studies showed that green tea extract (GTE) at mild (1.25 g%, identical to 5 cups of tea/day), moderate (2.5 g%, identical to 10 cups of tea/day) and high (5.0 g%, identical to 20 cups of tea/day) doses, for a period of 26 days, altered morphology and histology of testis and accessory sex organs. A significant dose-dependent decrease in the sperm counts, inhibited activities of testicular delta(5)3beta-and 17beta-hydroxysteroid dehydrogenase (delta5-3beta3-HSD and 17beta3-HSD respectively) and decreased serum testosterone level were noticed. Significant increase in serum LH level was observed after moderate and high doses; serum FSH level also increased but not significantly. Histopathological examination showed inhibition of spermatogenesis evidenced by preferential loss of matured and elongated spermatids. Results of this study showed that GTE at relatively high dose may cause impairment of both the morphological and normal functional status of testis in rodents and thus its consumption at relatively high doses raises concern on male reproductive function in spite of its other beneficial effects.

  3. Altered Morphologies and Functions of the Olfactory Bulb and Hippocampus Induced by miR-30c

    PubMed Central

    Sun, Tingting; Li, Tianpeng; Davies, Henry; Li, Weiyun; Yang, Jing; Li, Shanshan; Ling, Shucai

    2016-01-01

    Adult neurogenesis is considered to contribute to a certain degree of plasticity for the brain. However, the effects of adult-born neurons on the brain are still largely unknown. Here, we specifically altered the expression of miR-30c in the subventricular zone (SVZ) and dentate gyrus (DG) by stereotaxic injection with their respective up- and down-regulated lentiviruses. Results showed an increased level of miR-30c enhanced adult neurogenesis by prompting cell-cycles of stem cells, whereas down-regulated miR-30c led to the opposite results. When these effects of miR-30c lasted for 3 months, we detected significant morphological changes in the olfactory bulb (OB) and lineage alteration in the hippocampus. Tests of olfactory sensitivity and associative and spatial memory showed that a certain amount of adult-born neurons are essential for the normal functions of the OB and hippocampus, but there also exist redundant newborn neurons that do not further improve the functioning of these areas. Our study revealed the interactions between miRNA, adult neurogenesis, brain morphology and function, and this provides a novel insight into understanding the role of newborn neurons in the adult brain. PMID:27242411

  4. New family of allomorphic jellyfishes, Drymonematidae (Scyphozoa, Discomedusae), emphasizes evolution in the functional morphology and trophic ecology of gelatinous zooplankton.

    PubMed

    Bayha, Keith M; Dawson, Michael N

    2010-12-01

    Molecular analyses have revealed many cryptic species in the oceans, often permitting small morphological differences to be recognized as diagnosing species, but less commonly leading to consideration of cryptic ecology. Here, based on analyses of three nuclear DNA sequence markers (ribosomal 18S, 28S, and internal transcribed spacer 1 [ITS1]), two mitochondrial DNA markers (cytochrome c oxidase subunit I [COI] and ribosomal 16S), and 55 morphological features, we revise the classification of the enigmatic jellyfish genus Drymonema. We describe a new scyphozoan family, Drymonematidae, elevating the previous subfamily Drymonemidae to accommodate three species: the type species D. dalmatinum from the Mediterranean region, for which we identify a neotype; the western South Atlantic species D. gorgo; and a new species, D. larsoni from the western Atlantic and Caribbean, which also is described here. This revision emphasizes the remarkable morphological disparity of Drymonematidae from all other scyphomedusae, including allometric growth of the bell margin distal of the rhopalia, an annular zone of tentacles on the subumbrella, and ontogenetic loss of gastric filaments. Anatomical innovations are likely functionally related to predatory specialization on large gelatinous zooplankton, most notably the phylogenetically younger moon jellyfish Aurelia, indicating evolution of the feeding niche in Drymonematidae. This family-level revision contributes to the growing body of evidence that scyphomedusae are far more taxonomically rich, their biogeography is a more detailed mosaic, and their phenotypes are more nuanced than traditionally thought. Ecological and evolutionary responses to environmental change, past or future, are likely to be commensurately diverse.

  5. Effect of a new functional double-hydrophilic block copolymer PAAL on the morphology of calcium carbonate particles

    SciTech Connect

    Lei, M. . E-mail: leiming@aphy.iphy.ac.cn; Tang, W.H.; Yu, J.G.

    2005-04-20

    Calcium carbonate (CaCO{sub 3}) particles with various shapes were prepared by the reaction of sodium carbonate with calcium chloride in the presence of a new functional double-hydrophilic block copolymer poly (acrylic acid)-block-(acrylic hydroxy lactide) (PAAL) at room temperature. The as-prepared products were characterized with scanning electron microscopy and X-ray diffraction. The effects of pH, concentration of PAAL and CaCO{sub 3} on the crystal form and morphologies of the as-prepared CaCO{sub 3} were investigated. The results show that pH, concentration of PAAL and CaCO{sub 3} are important parameters for the control of morphologies of CaCO{sub 3}. Depending on the experimental conditions, various morphologies of CaCO{sub 3}, such as plate-like aggregates, poly-nucleated spheres, ellipsoids, monodispersed spheres, rhombohedras, etc., can be obtained. Especially, the optimal experimental conditions for the production of monodispersed spherical CaCO{sub 3} particles were determined.

  6. Oropharyngeal morphology in the basal tortoise Manouria emys emys with comments on form and function of the testudinid tongue.

    PubMed

    Heiss, Egon; Natchev, Nikolay; Schwaha, Thomas; Salaberger, Dietmar; Lemell, Patrick; Beisser, Christian; Weisgram, Josef

    2011-10-01

    In tetrapods, the ability to ingest food on land is based on certain morphological features of the oropharynx in general and the feeding apparatus in particular. Recent paleoecological studies imply that terrestrial feeding has evolved secondarily in turtles, so they had to meet the morphological oropharyngeal requirements independently to other amniotes. This study is designed to improve our limited knowledge about the oropharyngeal morphology of tortoises by analyzing in detail the oropharynx in Manouria emys emys. Special emphasis is placed on the form and function of the tongue. Even if Manouria is considered a basal member of the only terrestrial turtle clade and was hypothesized to have retained some features reflecting an aquatic ancestry, Manouria shows oropharyngeal characteristics found in more derived testudinids. Accordingly, the oropharyngeal cavity in Manouria is richly structured and the glands are large and complexly organized. The tongue is large and fleshy and bears numerous slender papillae lacking lingual muscles. The hyolingual skeleton is mainly cartilaginous, and the enlarged anterior elements support the tongue and provide insertion sides for the well-developed lingual muscles, which show striking differences to other reptiles. We conclude that the oropharyngeal design in Manouria differs clearly from semiaquatic and aquatic turtles, as well as from other reptilian sauropsids.

  7. Can they dig it? Functional morphology and semifossoriality among small-eared shrews, genus Cryptotis (Mammalia, Soricidae).

    PubMed

    Woodman, Neal; Gaffney, Sarah A

    2014-07-01

    Small-eared shrews (Mammalia: Soricidae: Cryptotis), exhibit modifications of the forelimb skeleton that have been interpreted as adaptations for semifossoriality. Most species inhabit remote regions, however, and their locomotory and foraging behaviors remain mostly speculative. To better understand the morphological modifications in the absence of direct observations, we quantified variation in these species by measuring 151 individuals representing 18 species and populations of Cryptotis and two species of moles (Talpidae) for comparison. From our measurements, we calculated 22 indices, most of which have been used previously to characterize substrate use among rodents and other taxa. We analyzed the indices using 1) average percentile ranks, 2) principal components analysis, and 3) cluster analysis. From these analyses, we determined that three basic modes of substrate adaptation are present within Cryptotis: 1) a primarily terrestrial mode, with species that are capable of burrowing, but lack adaptations to increase digging efficiency, 2) a semifossorial mode, with species whose forelimbs bones show strong muscle attachment areas and increased mechanical advantage, and 3) an intermediate mode. In addition to identifying new morphological characters and contributing to our understanding of the functional morphology of soricids, these analyses provide additional insight into the ecology of the species of interest.

  8. Can they dig it? Functional morphology and semifossoriality among small-eared shrews, genus Cryptotis (Mammalia, Soricidae)

    USGS Publications Warehouse

    Woodman, Neal; Gaffney, Sarah A.

    2014-01-01

    Small-eared shrews (Mammalia: