Thick

Distribution by Scientific Domains
Distribution within Earth and Environmental Science

Kinds of Thick

  • cm thick
  • km thick
  • m thick
  • nm thick
  • very thick

  • Terms modified by Thick

  • thick coating
  • thick film
  • thick layer
  • thick material
  • thick melanoma
  • thick plate
  • thick section
  • thick sequence
  • thick shell
  • thick slice

  • Selected Abstracts


    PRESENTISM: THROUGH THICK AND THIN

    PACIFIC PHILOSOPHICAL QUARTERLY, Issue 3 2008
    H. SCOTT HESTEVOLD
    Without defending Presentism, I argue first that Presentists should be Time -Free Presentists , Presentists whose views do not imply that there exist irreducible times. Second, I argue that Presentists should accept Limited Thick Presentism, the view that ,the present' has some extension and is thereby neither durationlessly thin nor unlimitedly ,thick'. Third, before addressing several objections to Limited Time-Free Thick Presentism [LTFTP], I argue that defenders of LTFTP should accept that ,temporal becoming' involves an overlapping succession of present entities, not a ,skipping' from one set of present entities to the next discrete set. [source]


    Internal Kinematics of the Tongue Following Volume Reduction

    THE ANATOMICAL RECORD : ADVANCES IN INTEGRATIVE ANATOMY AND EVOLUTIONARY BIOLOGY, Issue 7 2008
    Volodymyr Shcherbatyy
    Abstract This study was undertaken to determine the functional consequences following tongue volume reduction on tongue internal kinematics during mastication and neuromuscular stimulation in a pig model. Six ultrasonic-crystals were implanted into the tongue body in a wedge-shaped configuration which allows recording distance changes in the bilateral length (LENG) and posterior thickness (THICK), as well as anterior (AW), posterior dorsal (PDW), and ventral (PVW) widths in 12 Yucatan-minipigs. Six animals received a uniform mid-sagittal tongue volume reduction surgery (reduction), and the other six had identical incisions without tissue removal (sham). The initial-distances among each crystal-pairs were recorded before, and immediately after surgery to calculate the dimensional losses. Referring to the initial-distance there were 3,66% and 1,4% tongue dimensional losses by the reduction and sham surgeries, respectively. The largest deformation in sham animals during mastication was in AW, significantly larger than LENG, PDW, PVW, and THICK (P < 0.01,0.001). In reduction animals, however, these deformational changes significantly diminished and enhanced in the anterior and posterior tongue, respectively (P < 0.05,0.001). In both groups, neuromuscular stimulation produced deformational ranges that were 2,4 times smaller than those occurred during chewing. Furthermore, reduction animals showed significantly decreased ranges of deformation in PVW, LENG, and THICK (P < 0.05,0.01). These results indicate that tongue volume reduction alters the tongue internal kinematics, and the dimensional losses in the anterior tongue caused by volume reduction can be compensated by increased deformations in the posterior tongue during mastication. This compensatory effect, however, diminishes during stimulation of the hypoglossal nerve and individual tongue muscles. Anat Rec, 291:886-893, 2008. © 2008 Wiley-Liss, Inc. [source]


    Formation of Hierarchically Structured Thin Films

    ADVANCED FUNCTIONAL MATERIALS, Issue 14 2009
    Ming Wang
    Abstract Here, we report the preparation of hierarchically structured polymer brushes with well-defined geometries via multiple step microcontact printing (MS-µCP) of inks containing different ratios of initiator-terminated thiols and non-reactive alkylthiols. Thick (and dense), polymer brushes grew from self-assembled monolayers (SAMs) with high concentration of initiator-terminated thiols, and these brushes exhibited high chemical etch-resistance, compared to thin (and less dense), brushes grown from more dilute initiator-terminated SAMs. Upon etching, patterned crosslinking polymer brush films decorated with thin layers of Au, could be lifted off the surface to form geometrically well-defined free-standing hierarchical films. These polymer brush films showed interesting buckling instabilities when compressed. Areas with different brush thicknesses and Au backing showed markedly different buckling behavior, leading to unusual patterns of wrinkles with different wavelengths and orientations toward the force field. [source]


    Permo-Triassic development from Ireland to Norway: basin architecture and regional controls

    GEOLOGICAL JOURNAL, Issue 6 2009
    tolfová
    Abstract Extensive occurrences of Permo-Triassic strata are preserved along the Northwest European Atlantic margin. Seismic reflection and well data are used to describe large-scale Permo-Triassic basin geometries along a swath of the continental shelf more than 2000,km long extending from the Irish to the mid-Norwegian sectors. Successions in the Celtic Sea, the flanks of the Irish Rockall Basin, basins west and north of Scotland, and the Trřndelag and Horda platforms west of Norway are described. The large-scale Permo-Triassic depositional geometries commonly represent erosional remnants of larger basins modified by later rifting episodes, uplift, inversion and continental breakup. However, the interpreted geometries reveal spatial and temporal differences in rifting style. The basins developed above a complex mosaic of petrologically heterogeneous crustal terranes with inherited crustal fabrics, which had a significant impact on the depositional basin geometries. Small Permian basins with growth faulting developed in the southern Celtic Sea region. Extensive, uniformly thick Triassic strata are characteristic of the wide rift basins in the southeastern Rockall Basin and northwest of the Solan Bank High. Thick, fault-controlled basins developed in the Horda and Trřndelag platform regions. The main controls on Permo-Triassic basin architecture are (a) crustal thickness and composition, which determined the development of narrow or wide rift basin geometries, (b) inherited Variscan, Caledonian and Precambrian basement structures and (c) pre-rift palaeotopography. Copyright © 2009 John Wiley & Sons, Ltd. [source]


    Artificial Recharge Through a Thick, Heterogeneous Unsaturated Zone

    GROUND WATER, Issue 3 2008
    John A. Izbicki
    Thick, heterogeneous unsaturated zones away from large streams in desert areas have not previously been considered suitable for artificial recharge from ponds. To test the potential for recharge in these settings, 1.3 × 106 m3 of water was infiltrated through a 0.36-ha pond along Oro Grande Wash near Victorville, California, between October 2002 and January 2006. The pond overlies a regional pumping depression 117 m below land surface and is located where thickness and permeability of unsaturated deposits allowed infiltration and saturated alluvial deposits were sufficiently permeable to allow recovery of water. Because large changes in water levels caused by nearby pumping would obscure arrival of water at the water table, downward movement of water was measured using sensors in the unsaturated zone. The downward rate of water movement was initially as high as 6 m/d and decreased with depth to 0.07 m/d; the initial time to reach the water table was 3 years. After the unsaturated zone was wetted, water reached the water table in 1 year. Soluble salts and nitrate moved readily with the infiltrated water, whereas arsenic and chromium were less mobile. Numerical simulations done using the computer program TOUGH2 duplicated the downward rate of water movement, accumulation of water on perched zones, and its arrival at the water table. Assuming 10 × 106 m3 of recharge annually for 20 years, a regional ground water flow model predicted water level rises of 30 m beneath the ponds, and rises exceeding 3 m in most wells serving the nearby urban area. [source]


    Fabrication of Thick (>10 ,m) GeO2 Ceramic Films by a Facile Liquid Phase Deposition Process

    JOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 11 2007
    Chengbin Jing
    GeO2 thick (>10 ,m) ceramic films were fabricated by facile liquid-phase deposition. The solubility of hexagonal GeO2 in water was increased ten times on adding aqueous ammonia at 70°C because of the formation of soluble Ge5O112,. With the addition of sulfuric acid, the alkaline GeO2,aqueous ammonia was neutralized, leading to the transformation of Ge5O112, into GeO2 precipitates. When the H2SO4/NH4OH molar ratio was higher than 11.7, immediate precipitation of GeO2 particles took place in the solution with no GeO2 particles deposited on the substrate. When the H2SO4/NH4OH molar ratio was decreased from 5.85 to 0.29, the precipitation process was retarded, leading to the gradual growth of uniform hexagonal GeO2 thick films on the substrates. The compactness of the film increased with a decrease in the H2SO4/NH4OH molar ratio. The growth of the GeO2 crystal film followed the Bravais,Freidel,Donnay,Harker and Hartman,Perdok models, and the cubic GeO2 particles with a size of about 10 ,m were finally formed on the film. No GeO2 precipitate was produced on the substrate when the GeO2,aqueous ammonia had an excessively low H2SO4/NH4OH molar ratio (,0.15) because the GeO2 solute did not reach the saturation level and the nucleation process could not take place on the substrate. The particles on the film surface deposited from the solution with an H2SO4/NH4OH molar ratio of 0.29 exhibited a nanopore structure. An initial study using this film as a support for KNO3 catalyst was carried out and the result revealed that the catalyst showed good catalytic activity of diesel soot oxidation. [source]


    Influence of cylinder-on-plate or block-on-ring sliding configurations on friction and wear of pure and filled engineering polymers

    LUBRICATION SCIENCE, Issue 2 2007
    P. Samyn
    Abstract Polyamides, polyesters and polyacetals are often used in line contacts under reciprocating or continuous sliding. These contacts are simulated on cylinder-on-plate (COP) or block-on-ring (BOR) tribotests. Comparative tests for pure, oil-filled and solid lubricated polymers at 100N and 0.3m/s are presented for relative material classification. Differences are discussed according to the sliding geometries. Thermal effects dominate friction and wear behaviour: the polymer glass transition temperature is exceeded in COP tests while the temperature is lower in BOR tests. Thick and brittle films are observed for pure polymers in BOR tests, promoting higher friction. The test configuration is mainly important for evaluation of internal lubricants. The efficiency of oil-lubricated polymers is not demonstrated in COP tests, while solid lubricants are not efficient in BOR tests. Deformation restricts the diffusion of oil lubricants in COP tests while solid lubricants are deposited on the polymer surface rather than being incorporated in the transfer film in BOR tests. Copyright © 2007 John Wiley & Sons, Ltd. [source]


    Thick, cheap and easy: Fortifying texture-modified meals with infant cereal

    NUTRITION & DIETETICS, Issue 2 2007
    Suzanne KENNEWELL
    Abstract Patients requiring texture-modified meals, particularly those with dysphagia, were identified as being at high risk of malnutrition and aspiration. The innovative use of a common infant cereal as an iron-fortified thickening agent significantly improved food texture and increased iron content of pureed and minced meals by 57%, without any discernible change in flavour. These results are currently benefiting up to 33% of patients and can be directly applied to all areas where consumers require thickened, iron-rich texture-modified meals with minimal additional cost. [source]


    Improvements in crystalline quality of thick GaN layers on GaAs (111)A by periodic insertion of low-temperature GaN buffer layers

    PHYSICA STATUS SOLIDI (C) - CURRENT TOPICS IN SOLID STATE PHYSICS, Issue 7 2003
    H. Murakami
    Abstract Thick and high quality GaN layer growth using periodic insertion of low-temperature (LT)-grown GaN buffer layers was investigated by metalorganic hydrogen chloride vapor phase epitaxy (MOHVPE). Both morphological and optical properties of GaN epitaxial layers were drastically improved by inserting a second LT-GaN buffer layer. Also, the thickness of the second buffer layer was found to affect the quality of subsequently grown epitaxial layers. The full-width at half maximum (FWHM) value of X-ray diffraction for () plane (, scan) of the GaN layer with double buffer layer structure decreased to 608 arcsec whereas that with single buffer structure was 3600 arcsec. These results indicate that the free-standing GaN substrate with low dislocation density can be possible by reiterating the growth sequence of buffer layer and epitaxial layer. (© 2003 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]


    Do Informed Traders Trade More When the Market Is Thick?

    ASIA-PACIFIC JOURNAL OF FINANCIAL STUDIES, Issue 4 2010
    Evidence from the Nikkei 225 Index Redefinition of April 2000
    G10; G14; G15 Abstract Using the Nikkei 225 index redefinition that took place in April 2000, we examine whether informed traders strategically trade more when they face increased liquidity trading, as predicted by Admati & Pfleiderer (1988). The significant increase (decrease) in liquidity trading for the new additions (deletions) caused by index trading activities after index redefinition offers a valuable opportunity to empirically test the predictions of Admati and Pfleiderer. The April 2000 index redefinition was not accompanied by any information effects because the event itself was unrelated to changes in firm fundamentals, nor did it involve any information confirmation effects. Our empirical findings support the predictions of the strategic information trader model. We find that informed trading, as measured by the probability of informed trading, increases significantly after additions and decreases significantly after deletions. Further analysis reveals that probability of informed trading changes are associated with changes in investor composition, especially for domestic institutions and foreign shareholders. [source]


    Preterm and at term children: morphological and functional analysis of optic nerve and visual pathway with OCT, HRT and pVEP

    ACTA OPHTHALMOLOGICA, Issue 2009
    R ANGELI
    Purpose To compare optic nerve morphology and visual function in 14 preterm children(mean gestational age:33,38) with normal cerebral ultrasound at birth and 15 at term children (mean gestational age:39,67). Methods Mean preterm age was 7,6 years, mean at term was 9,1 years. Children underwent to complete functional and morphological evaluation of Optic Nerve Head (ONH) with Heidelberg Retinal Tomography and Optical Coherence Tomography. The same children were evaluated at birth and at the time of morphological examinations by mean of transient and steady state pVEP. Results Mean visual acuity was 9,85 in the preterm, 10 in the at term children. HRT in preterm and at term children at term(n=28) preterm(n=25) P value mean sd mean sd Disc Area 2,5 0,7 2,34 0,68 0,38 Cup Area 0,50 0,44 0,58 0,47 0,51 Rim Area 2 0,45 1,76 0,37 0,047 C/D Area Ratio 0,18 0,12 0,22 0,14 0,23 C/D Linear Ratio 0,4 0,15 0,45 0,16 0,30 Mean RNFL Thick 0,2 0,07 0,24 0,2 0,26 Tab.1 A statistically significant reduction was found in preterm children as regard rim area (p=0,047,tab 1) at HRT and superior RNFL thickness (p=0,01), temporal and inferior inner macular thickness (p=0,03) at OCT. Differences in the pVep latencies were found at 3 and 8 months after birth, but not at the time of morphological examination. Steady State pVEP amplitudes differences were not statistically significant. Conclusion Morphologic optic disk and macula differences between term and preterm children seems not functionally affect the visual pathway. [source]


    Congenital malaria in neonates: two case reports and review of the literature

    ACTA PAEDIATRICA, Issue 4 2008
    Gaelle Vottier
    Abstract, Congenital malaria is uncommon in nonendemic countries. We describe two cases involving neonates hospitalized with fever, anaemia and thrombocytopaenia. Thick and thin blood smears were positive for Plasmodium vivax (P. vivax) and P. ovale, respectively. These two cases were discussed regarding the literature and potential implications of HIV coinfection in the mother. Conclusion: Consistent data in the literature suggest that peripheral blood films should be performed in HIV-positive women who travelled to an endemic area or with a history of malaria prior to gestation. With today's travelling patterns, congenital malaria should be considered as an important differential diagnosis of neonatal sepsis. [source]


    Stable stylized wireframe rendering

    COMPUTER ANIMATION AND VIRTUAL WORLDS (PREV: JNL OF VISUALISATION & COMPUTER ANIMATION), Issue 3-4 2010
    Chen Tang
    Abstract Stylized wireframe rendering of 3D model is widely used in animation software in order to depict the configuration of deformable model in comprehensible ways. However, since some inherent flaws in traditional depth test based rendering technology, shape of lines can not been preserved as continuous movement or deformation of models. There often exists severe aliasing like flickering artifact when objects rendered in line form animate, especially rendered with thick or dashed line. To cover this artifact, unlike traditional approach, we propose a novel fast line drawing method with high visual fidelity for wireframe depiction which only depends on intrinsic topology of primitives without any preprocessing step or extra adjacent information pre-stored. In contrast to previous widely-used solutions, our method is advantageous in highly accurate visibility, clear and stable line appearance without flickering even for thick and dashed lines with uniform width and steady configuration as model moves or animates, so that it is strongly suitable for animation system. In addition, our approach can be easily implemented and controlled without any additional preestimate parameters supplied by users. Copyright © 2010 John Wiley & Sons, Ltd. [source]


    Spectroscopic Diagnostics of Pulsed arc Plasmas for Particle Generation

    CONTRIBUTIONS TO PLASMA PHYSICS, Issue 8 2008
    K. Behringer
    Abstract Pulsed arc plasmas were diagnosed by means of emission spectroscopy. A capacitor was discharged through argon and hydrogen leading to a few cycles of damped current oscillation with ,120 ,s period and 5-12 kA maximum current. Spectroscopic measurements in the visible range were carried out in order to characterise the electron temperature and density in the arc channel as well as electron and gas temperatures in the afterglow plasmas. Spectra were integrated over 10 ,s time windows and shifted in time from pulse to pulse. The plasmas also contained substantial fractions of electrode material (brass), namely copper and zinc. The electron density was measured in the conventional way from the broadening of H, or from the Ar I Stark width. In the arc channel, it ranged from about 3 · 1022 to 2 · 1023 m,3. The broadening of Zn II lines could also be used. Ratios of Ar I to Ar II and of Zn I to Zn II line intensities were analysed for the electron temperature. Line pairs were found which lay conveniently close in one frame of the spectrometer allowing automatic on-line analysis without relying on reproducibility. Atomic physics models including opacity were developed for Ar II and Zn II in order to check the existence of a Boltzmann distribution of their excited states. These calculations showed that the observed levels were in fact close to thermodynamic equilibrium, in particular, if the resonance lines were optically thick. Electron temperature measurements yielded values between 14000 K and 21000 K. The gas temperature in the afterglow, where particles should have formed, was derived from the rotational and vibrational temperatures of C2 molecular bands. Ratios between Cu I line intensities yielded the electron temperatures. Both were found to be a few 1000 K. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]


    Growth of big single crystals of a new magnetic superconducting double perovskite Ba2PrRu1,xCuxO6

    CRYSTAL RESEARCH AND TECHNOLOGY, Issue 2 2006
    S. M. Rao
    Abstract Single crystals of Ba2PrRu1,xCuxO6 with x = 0 to 0.2, have been grown from high temperature solutions of a mixture of PbO-PbF2 in the temperature range 1100,1200 °C. Thin crystals with mostly a hexagonal and triangular plate like habit measuring up to 1,2 mm across and 0.1,0.2 mm thick were obtained. The size, quality and morphology of the crystals were improved by varying the solution volume as well as additives like B2O3. Large crystals measuring up to 3 mm across and 0.3 to 0.5 mm thick were obtained with 5,7 wt% solute concentration and 0.51 wt% of B2O3. The ZFC curves exhibit a spin glass like behavior with x = 0 and a superconducting transition at 8 to 11 K depending on x = 0.05 to 0.1. The transition was also influenced by the growth temperature and post growth annealing. Powder x-ray diffraction, EDS and Raman spectroscopic measurements confirm the presence of Cu in the crystals. (© 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]


    Interferon Alfa-2b or Not 2b?

    DERMATOLOGIC SURGERY, Issue 1 2007
    Significant Differences Exist in the Decision-Making Process between Melanoma Patients Who Accept or Decline High-Dose Adjuvant Interferon Alfa-2b Treatment
    BACKGROUND Patients with thick (Breslow >4 mm) primary melanoma and/or regional nodal metastasis have a high risk of tumor recurrence. High-dose adjuvant interferon (IFN) alfa-2b offers ,10% improvement in relapse-free survival and overall survival with significant toxicity. OBJECTIVE The objective was to determine which prognostic factors and patient characteristics are significant in the decision to undergo IFN therapy. METHODS Of 781 patients who underwent sentinel lymph node (SLN) biopsy, 135 of 781 (17.3%) had positive SLN or thick melanomas and were informed of a ,50% risk of recurrence/disease-related mortality and offered IFN. Telephone surveys delineated reasons behind patients' decisions to accept IFN. RESULTS Acceptors, 60 of 135 (45%), decided to take IFN alfa-2b whereas 75 of 135 (55%) declined. Being female (OR, 2.4; 95% CI, 1.17,5.03; p=.017) and positive SLN status (OR, 2.2; 95% CI, 1.01,4.97; p=.048) were strongly associated with patients who chose IFN. Acceptors of IFN were younger, more influenced by physicians, and less affected by depression and side effect profile (p<.05 for all). Decliners were more concerned by strained relationships with family and social life (p<.05). CONCLUSIONS Gender and positive SLN were predictive of high-risk melanoma patients' acceptance of IFN treatment. Physician insight into melanoma patients' therapeutic decision-making process can guide patients through this difficult disease. [source]


    Patterns of Detection of Superficial Spreading and Nodular-Type Melanoma: A Multicenter Italian Study

    DERMATOLOGIC SURGERY, Issue 11 2004
    Paolo Carli
    Background. Nodular histotype represents the condition that is mostly associated with diagnosis of thick melanoma. Objective. The objectives were to evaluate variables associated with and pattern of detection of nodular melanomas and to investigate variables associated with early diagnosis in accordance with histotype (nodular vs. superficial spreading melanomas). Methods. From the original data set of 816 melanomas, all the invasive lesions classified as superficial spreading (n=500) and nodular (n=93) melanomas were considered for the study. A multivariate logistic analysis was performed. Results. Nodular melanomas did not significantly differ from superficial spreading melanomas regarding sex, anatomic site, number of whole-body nevi, and the presence of atypical nevi. As expected, nodular melanomas were represented by a higher percentage of thick (>2 mm) lesions compared to superficial spreading melanomas (64.5% vs. 9.6%, p<0.001). The pattern of detection significantly differed between nodular and superficial spreading melanomas, the former being more frequently self-detected (44.1% vs. 38.0%) or detected by the family doctor (34.4% vs. 11.4%). Female sex, high level of education, and detection made by a dermatologist had an independent, protective effect against late (>1 mm in thickness) diagnosis in superficial spreading melanomas. No protective variable associated with nodular melanomas was found. Conclusion. Patterns of detection for nodular melanomas significantly differ from those for superficial spreading melanomas. For superficial spreading, but not for nodular, melanomas, variables associated with protective effect against late diagnosis can be identified. [source]


    Treatment of Facial Telangiectasia With Variable-Pulse High-Fluence Pulsed-Dye Laser: Comparison of Efficacy with Fluences Immediately Above and Below the Purpura Threshold

    DERMATOLOGIC SURGERY, Issue 7 2003
    Murad Alam MD
    Background. Pulsed-dye laser treatment has been shown to be highly effective for the treatment of facial telangiectasia. Posttreatment purpura after such treatment has limited patient acceptance of the procedure. Objective. To determine whether purpura-free treatment with recently introduced variable-pulsed pulsed-dye lasers can effectively reduce facial telangiectasia. Methods. This was a prospective, randomized, controlled, nonblinded trial. Eleven patients received variable-pulse pulsed-dye laser treatment with and without induction of purpura. Telangiectasia were graded on a "telangiectasia density scale," on which a 1 signified extremely fine, sparsely distributed telangiectasia, and 5 referred to thick, ropelike telangiectasia covering the affected area. For each subject, two areas on either side of the facial midline with equivalent telangiectasia density ratings were randomized to the purpura and purpura-free treatment groups, respectively. All treatments used a 7-mm spot size and a 10-ms pulse duration. The fluence associated with the purpura threshold for each patient was determined in test areas. Purpura-free treatment entailed a fluence 1.0 J/cm2 less than the purpura threshold, and purpura-level treatment entailed a fluence 0.5 J/cm2 greater than the threshold. Results. Six weeks after a single purpura-free treatment, mean telangiectasia ratings were reduced from 2.7 to 2.4. Purpura-level treatments resulted in a decrease to 1.4 from the same baseline. Thicker, denser telangiectasia appeared to benefit more from purpura-level treatment (a mean telangiectasia density scale reduction of 1.7) than finer, sparser telangiectasia (a mean reduction of 0.8). In 81% of cases, both investigators and patients rated the side treated with purpura as undergoing a greater reduction in telangiectasia density. Conclusion. Although facial telangiectasia do improve after a single purpura-free treatment with the variable-pulse pulsed-dye laser, they improve more after purpura is induced. Purpura-free and purpura-level treatments may be close to equivalent for treating fine telangiectasia, but purpura-level treatments have a distinct advantage for treating thicker telangiectasia. Significantly, the variable-pulse pulsed-dye laser offers patients the option of effective treatment of some telangiectasia without bruising. [source]


    Villin: A marker for development of the epithelial pyloric border

    DEVELOPMENTAL DYNAMICS, Issue 1 2002
    Evan M. Braunstein
    Abstract In the adult gastrointestinal tract, the morphologic borders between esophagus and stomach and between stomach and small intestine are literally one cell thick. The patterning mechanisms that underlie the development of these sharp regional divisions from a once continuous endodermal tube are still obscure. In the embryonic endoderm of the developing gut, region-specific expression of certain genes (e.g., intestine-specific expression of the actin bundling protein villin) can be detected as early as 9.0 days post coitum, although the morphologic differentiation of the gut epithelium proper does not begin until 4 to 5 days later. By using a mouse model in which a ,-galactosidase marker has been inserted into the endogenous villin locus, we examined the development of the stomach/intestinal (pyloric) border during gut organogenesis. The data indicate that the border is not sharp from the outset. Rather, the initial border region is characterized by a decreasing gradient of villin/,-galactosidase expression that extends into the distal stomach. A sharp epithelial border of villin/,-galactosidase expression appears abruptly at day 16 and is further refined over the next 3 weeks to form the distinct one-cell-thick border characteristic of the adult. These results indicate that an important previously unrecognized patterning event occurs in the gut epithelium at 16 days; this event may define an epithelial compartment boundary between the stomach and the intestine. The villin/,-galactosidase mouse model characterized here provides an excellent substrate with which to further dissect the mechanisms involved in this patterning process. © 2002 Wiley-Liss, Inc. [source]


    Expression of AMH, SF1, and SOX9 in gonads of genetic female chickens during sex reversal induced by an aromatase inhibitor

    DEVELOPMENTAL DYNAMICS, Issue 2 2001
    Séverine Vaillant
    Abstract Aromatase inhibitors administered prior to histological signs of gonadal sex differentiation can induce sex reversal of genetic female chickens. Under the effects of Fadrozole (CGS 16949A), a nonsteroidal aromatase inhibitor, the right gonad generally becomes a testis, and the left gonad a testis or an ovotestis. We have compared the expression pattern of the genes encoding AMH (the anti-Müllerian hormone), SF1 (steroidogenic factor 1), and SOX9 (a transcription factor related to SRY) in these sex-reversed gonads with that in control testes and ovaries, using in situ hybridization with riboprobes on gonadal sections. In control males, the three genes are expressed in Sertoli cells of testicular cords; however, only SOX9 is male specific, since as observed previously AMH and SF1 but not SOX9 are expressed in the control female gonads. In addition to testicular-like cords, sex-reversed gonads present many lacunae with a composite, thick and flat epithelium. We show that during embryonic and postnatal development, AMH, SF1 and SOX9 are expressed in the epithelium of testicular-like cords and in the thickened part but not in the flattened part of the epithelium of composite lacunae. AMH and SF1 but not SOX9 are expressed in follicular cells of ovotestes. Coexpression of the three genes, of which SOX9 is a specific Sertoli-cell marker, provides strong evidence for the transdifferentiation of ovarian into testicular epithelium in gonads of female chickens treated with Fadrozole. © 2001 Wiley-Liss, Inc. [source]


    Dutch solutions for liquid-based cytology: Analysis of unsatisfactory slides and HPV testing of equivocal cytology

    DIAGNOSTIC CYTOPATHOLOGY, Issue 9 2006
    Mathilde E. Boon M.D., Ph.D.
    Abstract The liquid-based techniques to obtain microscopy slides for cervical screening have replaced conventional smears almost completely in the USA, but not in all European countries. The decision making process to use liquid-based cytology (LBC) for nationwide screening programs depends on the health system. In a pilot study of over 7,000 screenees, we analyzed the unsatisfactory LBC slides and tested the equivocal cytologies for HPV by using the LiPA test. For comparison over 48,000 conventional screening data were used. Compared to conventional smears, the LBC slides were highly cellular, the state of fixation was much better, and obscuring blood did not exist. The unsatisfactory rate showed an increase from 262/100,000 (conventional smears) to 357/100,000 (LBC slides) due to too thick, undiagnosable epithelial fragments on the LBC slides. HPV testing of the equivocal cytology leads to a better patient management and less unnecessary referrals. Diagn. Cytopathol. 2006;34:644,648. © 2006 Wiley-Liss, Inc. [source]


    Through thick and thin: good and its determinates

    DIALECTICA, Issue 2 2004
    Christine Tappolet
    What is the relation between the concept good and more specific or ,thick' concepts such as admirable or courageous? I argue that good or more precisely good pro tanto is a general concept, but that the relation between good pro tanto and the more specific concepts is not that of a genus to its species. The relation of an important class of specific evaluative concepts, which I call ,affective concepts', to good pro tanto is better understood as one between a determinable and its determinates, whereas concepts such as courageous can be analysed in terms of affective concepts and purely descriptive concepts. [source]


    MAGNIFYING ENDOSCOPY WITH NARROW BAND IMAGING FOR EARLY DIFFERENTIATED GASTRIC ADENOCARCINOMA

    DIGESTIVE ENDOSCOPY, Issue 3 2008
    Kazuyoshi Yagi
    We have been using magnifying endoscopy with narrow band imaging (NBI) to study early differentiated gastric adenocarcinomas and to assess the relationship between microvessel pattern, pit pattern and histological pattern. The magnified view of the cancerous area showed three types of pattern: (i) a mesh pattern, consisting of mesh-like connected microvessels; (ii) a loop pattern, consisting of loop-like microvessels that were not connected and had tubule-like or villus-like mucosal structures along them; and (iii) an interrupted pattern, consisting of interrupted thick or thin vessels without mucosal structures. The mesh type of microvascular pattern showed a round pit pattern in 88.9% of cases (32/36) and the loop type of microvascular pattern showed a non-round pit pattern in 100% of cases. Among lesions that showed a mesh pattern or a loop pattern, 94.9% (56/59) were mucosal cancer and 5.1% (3/59) were submucosal cancer. However, 92.3% (12/13) of lesions that showed an interrupted pattern were submucosal differentiated adenocarcinoma and 7.7% (1/13) were mucosal differentiated adenocarcinoma. The present findings provide basic data on the characteristics of mucosal differentiated gastric adenocarcinoma revealed by magnifying endoscopy with NBI, as well as invasive changes such as submucosal invasion. [source]


    Phylogenetic comparison of spicule networks in cryptobranchiate dorid nudibranchs (Gastropoda, Euthyneura, Nudibranchia, Doridina)

    ACTA ZOOLOGICA, Issue 4 2008
    Brian K. Penney
    Abstract Many dorid nudibranchs possess large numbers of calcareous spicules in their mantle, gill, rhinophores and foot. However, the arrangements of these structures and their differences among taxa are poorly known. Spicule networks were stained with Alizarin red and compared among 12 species of cryptobranchiate dorid nudibranchs and four outgroups. Three general types of networks were found: a cobweb-like, unbraced framework of one or few spicules per side; a ramifying system of thick, spiculated tracts; and a lattice-like arrangement of distinct radial and circumferential tracts. The Discodorididae species investigated shared a cobweb-like network and papillae supported by a ring of spicules, while the Porostomata showed consistent characters leading to a lattice-like network with larger spicules in the central notum. The Dorididae studied were not cohesive, but each species shared characters with the aforementioned groups. Therefore, spicule network form may provide new characters to help resolve the phylogeny of Doridina. [source]


    Climatic influence on the inter-annual variability of late-Holocene minerogenic sediment supply in a boreal forest catchment

    EARTH SURFACE PROCESSES AND LANDFORMS, Issue 4 2010
    Gunilla Petterson
    Abstract Processes controlling sediment yield vary over a range of timescales, although most process-based observations are extremely short. Lake sediments, however, can be used to extend the observational timescale and are particularly useful when annually laminated (varved) sediment is present. The sediment record at Kassjön (N. Sweden) consists of ,6400 varves, each 0·5,1 mm thick. Image analysis was used to determine grey-scale variation and varve thickness from which annual minerogenic accumulation rate (MinAR) (mg cm,2 year,1) was inferred for the period 4486 BC , AD 1900. MinAR varies on annual to centennial scales and mainly reflects channel bank erosion by the inflow streams. The mineral input reflects the intensity of the spring run-off, which is dependent on the amount of snow accumulated during the winter, and hence MinAR is a long-term record of variability in past winter climate; other factors will be a variable response to catchment uplift, vegetation succession and pedogenesis. A major shift from low to high MinAR occurred ,250 BC, and peaks occurred around AD 250, 600, 1000, 1350 and 1650. Wavelet power spectrum analysis (confirmed by Fourier analyses) indicated significantly different periodicities throughout the period 4000 BC , AD 1700, including 275 years for the period 4000 BC , 2900 BC, 567 years for the period 2901 BC , 1201 BC, and 350 and 725 years for the period 1200 BC , AD 1700. The long-term, centennial scale variability (,350 years) may reflect solar forcing (cf the 385-year peak in tree-ring calibrated 14C activity) but interestingly, there is no obvious link to high frequency forcing, such as the North Atlantic Oscillation. The high resolution component of the record highlights the relevance of varved lake sediment records for understanding erosion dynamics in undisturbed forested catchments and their link to long-term climate dynamics and future climate change. Copyright © 2010 John Wiley & Sons, Ltd. [source]


    Overbank deposition along the concave side of the Red River meanders, Manitoba, and its geomorphic significance

    EARTH SURFACE PROCESSES AND LANDFORMS, Issue 13 2005
    Gregory R. Brooks
    Abstract Slow earth sliding is pervasive along the concave side of Red River meanders that impinge on Lake Agassiz glaciolacustrine deposits. These failures form elongated, low-angled (c. 6 to 10°) landslide zones along the valleysides. Silty overbank deposits that accumulated during the 1999 spring freshet extend continuously along the landslide zones over hundreds of metres and aggraded the lower slopes over a distance 50 to 80 m from the channel margin. The aggradation is not obviously related to meander curvature or location within a meander. Along seven slope profiles surveyed in 1999 near Letellier, Manitoba, the deposits locally are up to 21 cm thick and generally thin with increasing distance from, and height above, the river. Local deposit thickness relates to distance from the channel, duration of inundation of the landslide surface, mesotopography, and variations in vegetation cover. Immediately adjacent to the river, accumulated overbank deposits are up to 4 m thick. The 1999 overbank deposits also were present along the moderately sloped (c. 23 to 27°) concave banks eroding into the floodplain, but the deposits are thinner (locally up to c. 7 cm thick) and cover a narrower area (10 to 30 m wide) than the deposits within the landslide zones. Concave overbank deposition is part of a sediment reworking process that consists of overbank aggradation on the landslide zones, subsequent gradual downslope displacement from earth sliding, and eventually reworking by the river at the toe of the landslide. The presence of the deposits dampens the outward migration of the meanders and contributes to a low rate of contemporary lateral channel migration. Concave overbank sedimentation occurs along most Red River meanders between at least Emerson and St. Adolphe, Manitoba. © Her Majesty the Queen in right of Canada. [source]


    Spatial utilisation of fast-ice by Weddell seals Leptonychotes weddelli during winter

    ECOGRAPHY, Issue 3 2005
    Samantha Lake
    This study describes the distribution of Weddell seals Leptonychotes weddelli in winter (May,September 1999) at the Vestfold Hills, in Prydz Bay, East Antarctica. Specifically, we describe the spatial extent of haul-out sites in shore,fast sea-ice, commonly referred to as fast-ice. As winter progressed, and the fast-ice grew thick (ca 2 m), most of the inshore holes closed over, and the seals' distribution became restricted to ocean areas beyond land and islands. Using observations from the end of winter only, we fitted Generalised Additive Models (GAMs) to generate resource selection functions, which are models that yield values proportional to the probability of use. The models showed that seal distribution was defined mainly by distance to ice-edge and distance to land. Distance to ice-bergs was also selected for models of some regions. We present the results as maps of the fitted probability of seal presence, predicted by the binomial GAM for offshore regions, both with and without autocorrelation terms. The maps illustrate the expected distribution encompassing most of the observed distribution. On this basis, we hypothesise that propensity for the fast-ice to crack is the major determinant of Weddell seal distribution in winter. Proximity to open water and pack-ice habitats could also influence the distribution of haul-out sites in fast-ice areas. This is the first quantitative study of Weddell seal distribution in winter. Potential for regional variation is discussed. [source]


    Voltammetric Elucidation of Ion Transfer Through an Extremely Thin Membrane

    ELECTROANALYSIS, Issue 9 2004
    Nobuyuki Ichieda
    Abstract Digital simulation of the cyclic voltammogram for the ion transfer through a liquid membrane of thickness from 1,mm to 10,nm was performed. The magnitude of current and the shape of the voltammogram simulated for extremely thin membrane (10,nm thick) were similar to those observed experimentally with a bilayer lipid membrane, BLM, of about 10,nm in thick, when the diffusion coefficient of an ion in the BLM was assumed to be extraordinary small (10,13 to 10,14,cm2 s,1). [source]


    A New Optically Reflective Thin Layer Electrode (ORTLE) Window: Gold on a Thin Porous Alumina Film Used to Observe the Onset of Water Reduction

    ELECTROANALYSIS, Issue 1-2 2004

    Abstract The fabrication and unique characteristics of a new type of thin layer electrode, an optically reflective thin layer electrode (ORTLE), are described. The electrode was fabricated by the anodization of a thin layer of aluminum sputtered onto a plain glass microscope slide to create a 750,nm-thick porous alumina film. A thin film of gold was then sputtered atop the porous and transparent alumina film. The gold layer remained porous to allow solution into the pores but was optically thick and reflective. Reflectance measurements made through the microscope slide did not interrogate the bulk solution, but show spectral features that shift with the optical properties of the material filling the pores of the alumina film. A simple series of experiments, in which the potential of the ORTLE was stepped negatively to various values in an aqueous sodium sulfate solution, shows that interference fringes shift measurably in the ORTLE spectrum at potentials several hundred millivolts positive of the potential at which gas evolution was visible to the naked eye. [source]


    Confinement effects on the morphology of photopatterned porous polymer monoliths for capillary and microchip electrophoresis of proteins

    ELECTROPHORESIS, Issue 14 2008
    Mei He
    Abstract We find that the morphology of porous polymer monoliths photopatterned within capillaries and microchannels is substantially influenced by the dimensions of confinement. Porous polymer monoliths were prepared by UV-initiated free-radical polymerization using either the hydrophilic or hydrophobic monomers 2-hydroxyethyl methacrylate or butyl methacrylate, cross-linker ethylene dimethacrylate and different porogenic solvents to produce bulk pore diameters between 3.2 and 0.4,µm. The extent of deformation from the bulk porous structure under confinement strongly depends on the ratio of characteristic length of the confined space to the monolith pore size. The effects are similar in cylindrical capillaries and D-shaped microfluidic channels. Bulk-like porosity is observed for a confinement dimension to pore size ratio >10, and significant deviation is observed for a ratio <5. At the extreme limit of deformation a smooth polymer layer ,300 nm thick is formed on the surface of the capillary or microchannel. Surface tension or wetting also plays a role, with greater wetting enhancing deformation of the bulk structure. The films created by extreme deformation provide a rapid and effective strategy to create robust wall coatings, with the ability to photograft various surface chemistries onto the coating. This approach is demonstrated through cationic films used for electroosmotic flow control and neutral hydrophilic coatings for electrophoresis of proteins. [source]