The Origin of Ina: Evidence for Inflated Lava Flows on the Moon
NASA Technical Reports Server (NTRS)
Garry, W. B.; Robinson, M. S.; Zimbelman, J. R.; Bleacher, J. E.; Hawke, B. R.; Crumpler, L. S.; Braden, S. E.; Sato, H.
2012-01-01
Ina is an enigmatic volcanic feature on the Moon known for its irregularly shaped mounds, the origin of which has been debated since the Apollo Missions. Three main units are observed on the floor of the depression (2.9 km across, < or =64 m deep) located at the summit of a low-shield volcano: irregularly shaped mounds up to 20 m tall, a lower unit 1 to 5 m in relief that surrounds the mounds, and blocky material. Analyses of Lunar Reconnaissance Orbiter Camera images and topography show that features in Ina are morphologically similar to terrestrial inflated lava flows. Comparison of these unusual lunar mounds and possible terrestrial analogs leads us to hypothesize that features in Ina were formed through lava flow inflation processes. While the source of the lava remains unclear, this new model suggests that as the mounds inflated, breakouts along their margins served as sources for surface flows that created the lower morphologic unit. Over time, mass wasting of both morphologic units has exposed fresh surfaces observed in the blocky unit. Ina is different than the terrestrial analogs presented in this study in that the lunar features formed within a depression, no vent sources are observed, and no cracks are observed on the mounds. However, lava flow inflation processes explain many of the morphologic relationships observed in Ina and are proposed to be analogous with inflated lava flows on Earth.
Kobayashi, Akira; Yokogawa, Hideaki; Higashide, Tomomi; Nitta, Koji; Sugiyama, Kazuhisa
2012-03-01
To demonstrate the clinical significance of owl eye morphologic features observed by in vivo laser confocal microscopy in patients with cytomegalovirus (CMV) corneal endotheliitis. Observational case series. participants: Six eyes of 6 patients (6 men; mean age, 73.3 years) with cytomegalovirus corneal endotheliitis diagnosed by clinical manifestations together with polymerase chain reaction from aqueous humor samples. intervention: All patients were examined by slit-lamp biomicroscopy and in vivo laser confocal microscopy. main outcome measures: Clinical manifestations were summarized by reviewing medical records. Selected confocal images of corneal layers were evaluated qualitatively for shape and degree of light reflection of abnormal cells and deposits. All patients had long histories of anterior uveitis with intraocular pressure elevation, corneal edema with keratic precipitates, and decrease of endothelial cell densities. Coin-shaped lesions were observed by slit lamp only in 1 patient at the first visit and in 2 additional patients at subsequent follow-up. In all patients, confocal microscopy demonstrated reduced subepithelial nerves, subepithelial opacity, increased reflectivity of keratocytes, highly reflective dots, and needle-shaped bodies. Owl eye morphologic features were observed consistently in all patients at the initial visit, and highly reflective round bodies were detected in 5 patients; most notably, these confocal features were reversible after resolution of endotheliitis. Owl eye morphologic features and highly reflective round bodies observed by confocal microscopy may be useful as an adjunct for the noninvasive diagnosis of cytomegalovirus corneal endotheliitis. Reversibility of these features after resolution of endotheliitis may be useful for monitoring the therapeutic effects without multiple anterior chamber tap. Copyright © 2012 Elsevier Inc. All rights reserved.
CN Morphology Studies of Comet 103P/Hartley 2
NASA Astrophysics Data System (ADS)
Knight, Matthew M.; Schleicher, David G.
2011-06-01
We report on narrowband CN imaging of Comet 103P/Hartley 2 obtained at Lowell Observatory on 39 nights from 2010 July until 2011 January. We observed two features, one generally to the north and the other generally to the south. The CN morphology varied during the apparition: no morphology was seen in July; in August and September, the northern feature dominated and appeared as a mostly face-on spiral; in October, November, and December, the northern and southern features were roughly equal in brightness and looked like more side-on corkscrews; in January, the southern feature was dominant but the morphology was indistinct due to very low signal. The morphology changed smoothly during each night and similar morphology was seen from night to night. However, the morphology did not exactly repeat each rotation cycle, suggesting that there is a small non-principal axis rotation. Based on the repetition of the morphology, we find evidence that the fundamental rotation period was increasing: 16.7 hr from August 13 to 17, 17.2 hr from September 10 to 13, 18.2 hr from October 12 to 19, and 18.7 hr from October 31 to November 7. We conducted Monte Carlo jet modeling to constrain the pole orientation and locations of the active regions based on the observed morphology. Our preliminary, self-consistent pole solution has an obliquity of 10° relative to the comet's orbital plane (i.e., it is centered near R.A. = 257° and decl. = +67° with an uncertainty around this position of about 15°) and has two mid-latitude sources, one in each hemisphere.
CN MORPHOLOGY STUDIES OF COMET 103P/HARTLEY 2
DOE Office of Scientific and Technical Information (OSTI.GOV)
Knight, Matthew M.; Schleicher, David G., E-mail: knight@lowell.edu
2011-06-15
We report on narrowband CN imaging of Comet 103P/Hartley 2 obtained at Lowell Observatory on 39 nights from 2010 July until 2011 January. We observed two features, one generally to the north and the other generally to the south. The CN morphology varied during the apparition: no morphology was seen in July; in August and September, the northern feature dominated and appeared as a mostly face-on spiral; in October, November, and December, the northern and southern features were roughly equal in brightness and looked like more side-on corkscrews; in January, the southern feature was dominant but the morphology was indistinctmore » due to very low signal. The morphology changed smoothly during each night and similar morphology was seen from night to night. However, the morphology did not exactly repeat each rotation cycle, suggesting that there is a small non-principal axis rotation. Based on the repetition of the morphology, we find evidence that the fundamental rotation period was increasing: 16.7 hr from August 13 to 17, 17.2 hr from September 10 to 13, 18.2 hr from October 12 to 19, and 18.7 hr from October 31 to November 7. We conducted Monte Carlo jet modeling to constrain the pole orientation and locations of the active regions based on the observed morphology. Our preliminary, self-consistent pole solution has an obliquity of 10{sup 0} relative to the comet's orbital plane (i.e., it is centered near R.A. = 257{sup 0} and decl. = +67{sup 0} with an uncertainty around this position of about 15{sup 0}) and has two mid-latitude sources, one in each hemisphere.« less
Jurmu, Michael C
2002-12-01
Twelve morphological features from research on alluvial streams are compared in four narrow, low-gradient wetland streams located in different geographic regions (Connecticut, Indiana, and Wisconsin, USA). All four reaches differed in morphological characteristics in five of the features compared (consistent bend width, bend cross-sectional shape, riffle width compared to pool width, greatest width directly downstream of riffles, and thalweg location), while three reaches differed in two comparisons (mean radius of curvature to width ratio and axial wavelength to width ratio). The remaining five features compared had at least one reach where different characteristics existed. This indicates the possibility of varying morphology for streams traversing wetland areas further supporting the concept that the unique qualities of wetland environments might also influence the controls on fluvial dynamics and the development of streams. If certain morphological features found in streams traversing wetland areas differ from current fluvial principles, then these varying features should be incorporated into future wetland stream design and creation projects. The results warrant further research on other streams traversing wetlands to determine if streams in these environments contain unique morphology and further investigation of the impact of low-energy fluvial processes on morphological development. Possible explanations for the morphology deviations in the study streams and some suggestions for stream design in wetland areas based upon the results and field observations are also presented.
Yu, Kaixin; Wang, Xuetong; Li, Qiongling; Zhang, Xiaohui; Li, Xinwei; Li, Shuyu
2018-01-01
Morphological brain network plays a key role in investigating abnormalities in neurological diseases such as mild cognitive impairment (MCI) and Alzheimer's disease (AD). However, most of the morphological brain network construction methods only considered a single morphological feature. Each type of morphological feature has specific neurological and genetic underpinnings. A combination of morphological features has been proven to have better diagnostic performance compared with a single feature, which suggests that an individual morphological brain network based on multiple morphological features would be beneficial in disease diagnosis. Here, we proposed a novel method to construct individual morphological brain networks for two datasets by calculating the exponential function of multivariate Euclidean distance as the evaluation of similarity between two regions. The first dataset included 24 healthy subjects who were scanned twice within a 3-month period. The topological properties of these brain networks were analyzed and compared with previous studies that used different methods and modalities. Small world property was observed in all of the subjects, and the high reproducibility indicated the robustness of our method. The second dataset included 170 patients with MCI (86 stable MCI and 84 progressive MCI cases) and 169 normal controls (NC). The edge features extracted from the individual morphological brain networks were used to distinguish MCI from NC and separate MCI subgroups (progressive vs. stable) through the support vector machine in order to validate our method. The results showed that our method achieved an accuracy of 79.65% (MCI vs. NC) and 70.59% (stable MCI vs. progressive MCI) in a one-dimension situation. In a multiple-dimension situation, our method improved the classification performance with an accuracy of 80.53% (MCI vs. NC) and 77.06% (stable MCI vs. progressive MCI) compared with the method using a single feature. The results indicated that our method could effectively construct an individual morphological brain network based on multiple morphological features and could accurately discriminate MCI from NC and stable MCI from progressive MCI, and may provide a valuable tool for the investigation of individual morphological brain networks.
Distinct Morphology of Human T-Cell Leukemia Virus Type 1-Like Particles
Maldonado, José O.; Cao, Sheng; Zhang, Wei; Mansky, Louis M.
2016-01-01
The Gag polyprotein is the main retroviral structural protein and is essential for the assembly and release of virus particles. In this study, we have analyzed the morphology and Gag stoichiometry of human T-cell leukemia virus type 1 (HTLV-1)-like particles and authentic, mature HTLV-1 particles by using cryogenic transmission electron microscopy (cryo-TEM) and scanning transmission electron microscopy (STEM). HTLV-1-like particles mimicked the morphology of immature authentic HTLV-1 virions. Importantly, we have observed for the first time that the morphology of these virus-like particles (VLPs) has the unique local feature of a flat Gag lattice that does not follow the curvature of the viral membrane, resulting in an enlarged distance between the Gag lattice and the viral membrane. Other morphological features that have been previously observed with other retroviruses include: (1) a Gag lattice with multiple discontinuities; (2) membrane regions associated with the Gag lattice that exhibited a string of bead-like densities at the inner leaflet; and (3) an arrangement of the Gag lattice resembling a railroad track. Measurement of the average size and mass of VLPs and authentic HTLV-1 particles suggested a consistent range of size and Gag copy numbers in these two groups of particles. The unique local flat Gag lattice morphological feature observed suggests that HTLV-1 Gag could be arranged in a lattice structure that is distinct from that of other retroviruses characterized to date. PMID:27187442
NASA Astrophysics Data System (ADS)
Chang, Kuo-Jen; Chan, Yu-Chang; Chen, Rou-Fei; Hsieh, Yu-Chung
2018-03-01
Several remote sensing techniques, namely traditional aerial photographs, an unmanned aircraft system (UAS), and airborne lidar, were used in this study to decipher the morphological features of obscure landslides in volcanic regions and how the observed features may be used for understanding landslide occurrence and potential hazard. A morphological reconstruction method was proposed to assess landslide morphology based on the dome-shaped topography of the volcanic edifice and the nature of its morphological evolution. Two large-scale landslides in the Tatun volcano group in northern Taiwan were targeted to more accurately characterize the landslide morphology through airborne lidar and UAS-derived digital terrain models and images. With the proposed reconstruction method, the depleted volume of the two landslides was estimated to be at least 820 ± 20 × 106 m3. Normal faulting in the region likely played a role in triggering the two landslides, because there are extensive geological and historical records of an active normal fault in this region. The subsequent geomorphological evolution of the two landslides is thus inferred to account for the observed morphological and tectonic features that are indicative of resulting in large and life-threatening landslides, as characterized using the recent remote sensing techniques.
NASA Technical Reports Server (NTRS)
Bryan, W. B.
1976-01-01
Apollo 15 photographs of the southern parts of Serenitatis and Imbrium were used for a study of the morphology and distribution of wrinkle ridges. Volcanic and structural features along the south margin of Serenitatis were also studied, including the Dawes basalt cinder cones. Volcanic and structural features in crater Aitken were investigated as well. Study of crater Goclenius showed a close relationship between morphology of the impact crater and grabens which tend to parallel directions of the lunar grid. Similar trends were observed in the walls of crater Tsiolkovsky and other linear structures. Small craters of possible volcanic origin were also studied. Possible cinder cones were found associated with the Dawes basalt and in the floor of craters Aitken and Goclenius. Small pit craters were observed in the floors of these craters. Attempts were made to obtain contour maps of specific small features and to compare Orbiter and Apollo photographs to determine short term changes associated with other processes.
Coordinated Mapping of Sea Ice Deformation Features with Autonomous Vehicles
NASA Astrophysics Data System (ADS)
Maksym, T.; Williams, G. D.; Singh, H.; Weissling, B.; Anderson, J.; Maki, T.; Ackley, S. F.
2016-12-01
Decreases in summer sea ice extent in the Beaufort and Chukchi Seas has lead to a transition from a largely perennial ice cover, to a seasonal ice cover. This drives shifts in sea ice production, dynamics, ice types, and thickness distribution. To examine how the processes driving ice advance might also impact the morphology of the ice cover, a coordinated ice mapping effort was undertaken during a field campaign in the Beaufort Sea in October, 2015. Here, we present observations of sea ice draft topography from six missions of an Autonomous Underwater Vehicle run under different ice types and deformation features observed during autumn freeze-up. Ice surface features were also mapped during coordinated drone photogrammetric missions over each site. We present preliminary results of a comparison between sea ice surface topography and ice underside morphology for a range of sample ice types, including hummocked multiyear ice, rubble fields, young ice ridges and rafts, and consolidated pancake ice. These data are compared to prior observations of ice morphological features from deformed Antarctic sea ice. Such data will be useful for improving parameterizations of sea ice redistribution during deformation, and for better constraining estimates of airborne or satellite sea ice thickness.
Using Spectroscopic Profiles to Study the Morphology of Comets
NASA Astrophysics Data System (ADS)
Harris, Ien; Pierce, Donna M.; Cochran, Anita L.
2016-10-01
We have used the integral-field unit spectrograph (the George and Cynthia Mitchell Spectrograph) on the 2.7m Harlan J. Smith telescope at McDonald Observatory to obtain spectroscopic images of the comae of several comets. The images were obtained for various radical species (C2, C3. CH, CN, NH2). Radial and azimuthal average profiles of the radical species were created to enhance any observed cometary coma morphological features. We compare the observed coma features across the observed species and over the different observation periods in order to constrain possible rotational states of the observed comets. We will present results for several comets, including 2009P1 (Garradd). This work was funded by NASA's Planetary Atmospheres program (Award No. NNX14AH186).
The Nature of the Optical "Jets" in the Spiral Galaxy NGC 1097
NASA Technical Reports Server (NTRS)
Wehrle, Ann E.; Keel, William C.; Jones, Dayton L.
1997-01-01
We present new observations of the jet features in the barred spiral galaxy NGC 1097, including optical spectroscopy of the brightest jet features, two-color optical imagery, new VLA mapping at 327 MHz, and archival 1.4 GHz VLA data reprocessed for improved sensitivity. No optical emission lines appear to an equivalent width limit of 15-30 A (depending on the line wavelength). The jets are uniformly blue, with B - V = 0.45 for the two well-observed jets R1 and R2. No radio emission from the jets is detected at either frequency; the 327-MHz data set particularly stringent limits on "fossil" emission from aging synchrotron electrons. The morphology of the jets is shown to be inconsistent with any conical distribution of emission enhanced by edge-brightening; their combination of transverse profile and relative narrowness cannot be reproduced with cone models. The optical colors, lack of radio emission, and morphology of the features lead us to conclude that they are tidal manifestations, perhaps produced by multiple encounters of the small elliptical companion NGC 1097A with the disk of NGC 1097. We present photometric and morphological comparisons to the tail of NGC 465 1, which is similar in scale and morphology to the northeast "dogleg" feature R1 in NGC 1097.
The role of in-situ measurements in scintillation modelling
NASA Astrophysics Data System (ADS)
Basu, S.; Basu, S.; Hanson, W. B.
It is shown that the conflicting equatorial scintillation observations obtained from greatly separated ground stations can be organized in the framework of a longitudinal variation of irregularity occurrence, given satellite-borne, in situ measurements of irregularity amplitude of the global F-region irregularity morphology's general features. High-inclination satellite data are used to delineate the morphological features of the polar cap by means of such a method. The lack of diurnal and magnetic control of the irregularity morphology within the low solar flux, northern winter polar cap distinguishes this region from the auroral oval regime. A polar-orbiting communication system sensitive to phase perturbations may observe large differences in the phase-to-amplitude scintillation ratio, as it traverses the auroral oval and proceeds into the polar cap, with its sun-aligned arc system.
NASA Technical Reports Server (NTRS)
Samarasinha, Nalin H.
2000-01-01
We show that the circular character of continuum structures observed in the coma of comet Hale-Bopp around the perihelion passage is most likely due to a dust jet from a large extended active region on the surface. Coma morphology due to a wide jet is different from that due to a narrow jet. The latter shows foreshortening effects due to observing geometry, wider jet produces more circular features. This circularization effect provides a self-consistent explanation for the evolution of near-perihelion coma morphology. No changes in the direction of the rotational angular momentum vector are required during this period in contrast to the models of Schleicher et al. This circularization effect also enables us to produce near-circular coma features in the S-E quadrant during 1997 late February and therefore questions the basic premise on which Sekanina bases his morphological arguments for a gravitationally bound satellite nucleus.
NASA Astrophysics Data System (ADS)
Murray, A. B.; Thomas, C.; Hurst, M. D.; Barkwith, A.; Ashton, A. D.; Ellis, M. A.
2014-12-01
Recent numerical modelling demonstrates that when sandy coastlines are affected predominantly by waves approaching from "high" angles (> ~45° between the coastline and wave crests at the offshore limit of shore-parallel contours), large-scale (kms to 100 kms) morphodynamic instabilities and finite-amplitude interactions can lead to the emergence of striking coastline features, including sand waves, capes and spits. The type of feature that emerges depends on the wave climate, defined as the angular distribution of wave influences on alongshore sediment transport. Under a constant wave climate, coastline morphology reaches a dynamical steady state; the cross-shore/alongshore aspect ratio and the general appearance of the features remains constant. In previous modelling involving wave-climate change, as well as comparisons between observed coastline morphologies and wave climates, it has been implicitly assumed that the morphology adjusts in a quasi-equilibrium fashion, so that at any time the coastline shape reflects the current forcing. However, here we present new model results showing pronounced path dependence in coastline morphodynamics. In experiments with a period of constant wave climate followed by a period of transition to a new wave climate and then a run-on phase, the features that exist during the run-on phase can be qualitatively and quantitatively different from those that would develop initially under the final wave climate. Although the features inherited from the past wave-climate history may in some case be true alternate stable states, in other cases the inherited features gradually decay toward the morphology that would be expected given the final wave climate. A suite of such experiments allows us to characterize how the e-folding timescale of this decay depends on 1) the initial wave climate, 2) the path through wave-climate space, and 3) the rate of transition. When the initial features are flying spits with cross-shore amplitudes of 6 - 8 km, e-folding times can be on the order of millennia or longer. These results could provide a new perspective when interpreting current and past coastline features. In addition, the complex paleo-coastline structure that develops in the coastal hinterlands in these experiments could be relevant to the structures observed in some coastal environments.
Morphological and immunohistochemical features of Cryptosporidium andersoni in cattle.
Masuno, K; Yanai, T; Hirata, A; Yonemaru, K; Sakai, H; Satoh, M; Masegi, T; Nakai, Y
2006-03-01
Light and electron microscopic features and immunohistochemical features of Cryptosporidium andersoni (C. andersoni) and host reaction in the mucosa were studied. Although the affected cattle demonstrated no apparent clinical signs, a severe infection of C. andersoni was observed in the abomasum. C. andersoni were round in shape, measured 6-8 microm in size and were mainly observed to be freely located in the gastric pits, being attached in occasional cases to the surface of the abomasum epithelium. Frequent inflammatory cells had infiltrated the lamina propria of the affected mucosa, and frequent mitotic figures were observed in epithelial cells at the dilated isthmus. To access the cell kinetics, the number of epithelial cells infected with C. andersoni were counted and compared with noninfected cattle. The number of gastric pit cells in infected cattle was significantly higher than that in the controls. The number of proliferative cells determined by the Ki-67 antigen in C. andersoni infected cattle was also significantly higher than that in the controls. Transmission electron microscopy and scanning electron microscopy revealed that the morphology of the C. andersoni organism was common to those of other Cryptosporidium spp. Immunohistochemically, several commercial antibodies against Cryptosporidium spp. showed positive reactions at the wall of these oocysts or parasitophorous vacuoles. This report is possibly the first to discuss the prominent hyperplasia of the abomasum mucosa, as well as morphologic features of C. andersoni in cattle.
Morphology of auroral zone radio wave scintillation
DOE Office of Scientific and Technical Information (OSTI.GOV)
Rino, C.L.; Matthews, S.J.
1980-08-01
This paper describes the morphology of midnight sector and morning sector auroral zone scintillation observations made over a two-year period using the Wideband satelite, which is in a sun-synchronous, low-altitude orbit. No definitive seasonal variation was found. The nighttime data showed the highest scintillation ocurrence levels, but significant amounts of morning scintillation were observed. For the most part the scintillation activity followed the general pattern of local magnetic activity. The most prominent feature in the nightime data is a localized amplitude and phase scintillation enhancement at the point where the propagation vector lies within an L shell. A geometrical effectmore » due to a dynamic slab of sheetlike structures in the F region is hypothesized as the source of his enhancement. The data have been sorted by magnetic activity, proximity to local midnight, and season. The general features of the data are in agreement with the accepted morphology of auroral zone scintillation.« less
NASA Astrophysics Data System (ADS)
Ocakoğlu, Neslihan; İşcan, Yeliz; Kılıç, Fatmagül; Özel, Oğuz
2018-06-01
Multi-beam bathymetric and multi-channel seismic reflection data obtained offshore Cide-Sinop have revealed important records on the latest transgression of the Black Sea for the first time. A relatively large shelf plain within the narrow southern continental shelf characterized by a flat seafloor morphology at -100 water depth followed by a steep continental slope leading to -500 m depth. This area is widely covered by submerged morphological features such as dunes, lagoons, possible aeolianites, an eroded anticline and small channels that developed by aeolian and fluvial processes. These morphological features sit upon an erosional surface that truncates the top of all seismic units and constitutes the seafloor over the whole shelf. The recent prograded delta deposits around the shelf break are also truncated by the similar erosional surface. These results indicate that offshore Cide-Sinop was once a terrestrial landscape that was then submerged. The interpreted paleoshoreline varies from -100 to -120 m. This variation can be explained by not only sea level changes but also the active faults observed on the seismic section. The effective protection of morphological features on the seafloor is the evidence of abrupt submergence rather than gradual. In addition, the absence of coastal onlaps suggests that these morphological features should have developed at low sea level before the latest sea level rise in the Black Sea.
Liu, Jinyun; Qu, Yingmin; Wang, Guoliang; Wang, Xinyue; Zhang, Wenxiao; Li, Jingmei; Wang, Zuobin; Li, Dayou; Jiang, Jinlan
2018-01-01
This article studies the morphological and mechanical features of multinuclear and mononuclear SW480 colon cancer cells by atomic force microscopy to understand their drug-resistance. The SW480 cells were incubated with the fullerenol concentrations of 1 mg/ml and 2 mg/ml. Morphological and mechanical features including the height, length, width, roughness, adhesion force and Young's modulus of three multinuclear cell groups and three mononuclear cell groups were imaged and analyzed. It was observed that the features of multinuclear cancer cells and mononuclear cancer cells were significantly different after the treatment with fullerenol. The experiment results indicated that the mononuclear SW480 cells were more sensitive to fullerenol than the multinuclear SW480 cells, and the multinuclear SW480 cells exhibited a stronger drug-resistance than the mononuclear SW480 cells. This work provides a guideline for the treatments of multinuclear and mononuclear cancer cells with drugs. © 2017 Wiley Periodicals, Inc.
Physical linkages between an offshore canyon and surf zone morphologic change
NASA Astrophysics Data System (ADS)
Hansen, Jeff E.; Raubenheimer, Britt; Elgar, Steve; List, Jeffrey H.; Lippmann, Thomas C.
2017-04-01
The causes of surf zone morphologic changes observed along a sandy beach onshore of a submarine canyon were investigated using field observations and a numerical model (Delft3D/SWAN). Numerically simulated morphologic changes using four different sediment transport formulae reproduce the temporal and spatial patterns of net cross-shore integrated (between 0 and 6.5 m water depths) accretion and erosion observed in a ˜300 m alongshore region, a few hundred meters from the canyon head. The observations and simulations indicate that the accretion or erosion results from converging or diverging alongshore currents driven primarily by breaking waves and alongshore pressure gradients. The location of convergence or divergence depends on the direction of the offshore waves that refract over the canyon, suggesting that bathymetric features on the inner shelf can have first-order effects on short-term nearshore morphologic change.
Recognition of children on age-different images: Facial morphology and age-stable features.
Caplova, Zuzana; Compassi, Valentina; Giancola, Silvio; Gibelli, Daniele M; Obertová, Zuzana; Poppa, Pasquale; Sala, Remo; Sforza, Chiarella; Cattaneo, Cristina
2017-07-01
The situation of missing children is one of the most emotional social issues worldwide. The search for and identification of missing children is often hampered, among others, by the fact that the facial morphology of long-term missing children changes as they grow. Nowadays, the wide coverage by surveillance systems potentially provides image material for comparisons with images of missing children that may facilitate identification. The aim of study was to identify whether facial features are stable in time and can be utilized for facial recognition by comparing facial images of children at different ages as well as to test the possible use of moles in recognition. The study was divided into two phases (1) morphological classification of facial features using an Anthropological Atlas; (2) algorithm developed in MATLAB® R2014b for assessing the use of moles as age-stable features. The assessment of facial features by Anthropological Atlases showed high mismatch percentages among observers. On average, the mismatch percentages were lower for features describing shape than for those describing size. The nose tip cleft and the chin dimple showed the best agreement between observers regarding both categorization and stability over time. Using the position of moles as a reference point for recognition of the same person on age-different images seems to be a useful method in terms of objectivity and it can be concluded that moles represent age-stable facial features that may be considered for preliminary recognition. Copyright © 2017 The Chartered Society of Forensic Sciences. Published by Elsevier B.V. All rights reserved.
Bustamante, Carlos; Lamilla, Julio; Concha, Francisco; Ebert, David A; Bennett, Michael B
2012-01-01
Detailed descriptions of morphological features, morphometrics, neurocranium anatomy, clasper structure and egg case descriptions are provided for the thickbody skate Amblyraja frerichsi; a rare, deep-water species from Chile, Argentina and Falkland Islands. The species diagnosis is complemented from new observations and aspects such as colour, size and distribution are described. Geographic and bathymetric distributional ranges are discussed as relevant features of this taxońs biology. Additionally, the conservation status is assessed including bycatch records from Chilean fisheries.
Bustamante, Carlos; Lamilla, Julio; Concha, Francisco; Ebert, David A.; Bennett, Michael B.
2012-01-01
Detailed descriptions of morphological features, morphometrics, neurocranium anatomy, clasper structure and egg case descriptions are provided for the thickbody skate Amblyraja frerichsi; a rare, deep-water species from Chile, Argentina and Falkland Islands. The species diagnosis is complemented from new observations and aspects such as colour, size and distribution are described. Geographic and bathymetric distributional ranges are discussed as relevant features of this taxońs biology. Additionally, the conservation status is assessed including bycatch records from Chilean fisheries. PMID:22768186
Morphology Of A Hot Prominence Cavity Observed with Hinode/XRT and SDO/AIA
NASA Technical Reports Server (NTRS)
Weber, Mark A.; Reeves, K. K.; Gibson, S. E.; Kucera, T. A.
2012-01-01
Prominence cavities appear as circularly shaped voids in coronal emission over polarity inversion lines where a prominence channel is straddling the solar limb. The presence of chromospheric material suspended at coronal altitudes is a common but not necessary feature within these cavities. These voids are observed to change shape as a prominence feature rotates around the limb. We use a morphological model projected in cross-sections to fit the cavity emission in Hinode/XRT passbands, and then apply temperature diagnostics to XRT and SDO/AIA data to investigate the thermal structure. We find significant evidence that the prominence cavity is hotter than the corona immediately outside the cavity boundary. This investigation follows upon "Thermal Properties of A Solar Coronal Cavity Observed with the X-ray Telescope on Hinode" by Reeves et al., 2012, ApJ, in press.
Martin, Jessica L; Cao, Sheng; Maldonado, Jose O; Zhang, Wei; Mansky, Louis M
2016-09-15
The Gag protein is the main retroviral structural protein, and its expression alone is usually sufficient for production of virus-like particles (VLPs). In this study, we sought to investigate-in parallel comparative analyses-Gag cellular distribution, VLP size, and basic morphological features using Gag expression constructs (Gag or Gag-YFP, where YFP is yellow fluorescent protein) created from all representative retroviral genera: Alpharetrovirus, Betaretrovirus, Deltaretrovirus, Epsilonretrovirus, Gammaretrovirus, Lentivirus, and Spumavirus. We analyzed Gag cellular distribution by confocal microscopy, VLP budding by thin-section transmission electron microscopy (TEM), and general morphological features of the VLPs by cryogenic transmission electron microscopy (cryo-TEM). Punctate Gag was observed near the plasma membrane for all Gag constructs tested except for the representative Beta- and Epsilonretrovirus Gag proteins. This is the first report of Epsilonretrovirus Gag localizing to the nucleus of HeLa cells. While VLPs were not produced by the representative Beta- and Epsilonretrovirus Gag proteins, the other Gag proteins produced VLPs as confirmed by TEM, and morphological differences were observed by cryo-TEM. In particular, we observed Deltaretrovirus-like particles with flat regions of electron density that did not follow viral membrane curvature, Lentivirus-like particles with a narrow range and consistent electron density, suggesting a tightly packed Gag lattice, and Spumavirus-like particles with large envelope protein spikes and no visible electron density associated with a Gag lattice. Taken together, these parallel comparative analyses demonstrate for the first time the distinct morphological features that exist among retrovirus-like particles. Investigation of these differences will provide greater insights into the retroviral assembly pathway. Comparative analysis among retroviruses has been critically important in enhancing our understanding of retroviral replication and pathogenesis, including that of important human pathogens such as human T-cell leukemia virus type 1 (HTLV-1) and HIV-1. In this study, parallel comparative analyses have been used to study Gag expression and virus-like particle morphology among representative retroviruses in the known retroviral genera. Distinct differences were observed, which enhances current knowledge of the retroviral assembly pathway. Copyright © 2016, American Society for Microbiology. All Rights Reserved.
González-Robles, Arturo; Lares-Villa, Fernando; Lares-Jiménez, Luis Fernando; Omaña-Molina, Maritza; Salazar-Villatoro, Lizbeth; Martínez-Palomo, Adolfo
2015-10-01
Additional morphological features of Balamuthia mandrillaris observed by light and electron microscopy are reported. Trophozoites were extremely pleomorphic: their cell shapes ranged from rounded to elongated and sometimes they appeared exceptionally stretched out and branched. By transmission electron microscopy it was possible to observe two different cytoplasmic areas, the ectoplasm and the endoplasm and often sections of rough endoplasmic reticulum were found in the transition zone. The cytoplasm was very fibrogranular and most of the organelles typically found in eukaryotic cells were observed. A particular finding was the presence of numerous mitochondria with a different structure from those of other free-living amoebae. The observations reported here may reinforce the morphological knowledge of this amoeba and provide a background for further analyses. Copyright © 2015 Elsevier Inc. All rights reserved.
Computational Modeling of Morphological Effects in Bangla Visual Word Recognition.
Dasgupta, Tirthankar; Sinha, Manjira; Basu, Anupam
2015-10-01
In this paper we aim to model the organization and processing of Bangla polymorphemic words in the mental lexicon. Our objective is to determine whether the mental lexicon accesses a polymorphemic word as a whole or decomposes the word into its constituent morphemes and then recognize them accordingly. To address this issue, we adopted two different strategies. First, we conduct a masked priming experiment over native speakers. Analysis of reaction time (RT) and error rates indicates that in general, morphologically derived words are accessed via decomposition process. Next, based on the collected RT data we have developed a computational model that can explain the processing phenomena of the access and representation of Bangla derivationally suffixed words. In order to do so, we first explored the individual roles of different linguistic features of a Bangla morphologically complex word and observed that processing of Bangla morphologically complex words depends upon several factors like, the base and surface word frequency, suffix type/token ratio, suffix family size and suffix productivity. Accordingly, we have proposed different feature models. Finally, we combine these feature models together and came up with a new model that takes the advantage of the individual feature models and successfully explain the processing phenomena of most of the Bangla morphologically derived words. Our proposed model shows an accuracy of around 80% which outperforms the other related frequency models.
Galaxy Zoo: Morphological Classification of Galaxy Images from the Illustris Simulation
NASA Astrophysics Data System (ADS)
Dickinson, Hugh; Fortson, Lucy; Lintott, Chris; Scarlata, Claudia; Willett, Kyle; Bamford, Steven; Beck, Melanie; Cardamone, Carolin; Galloway, Melanie; Simmons, Brooke; Keel, William; Kruk, Sandor; Masters, Karen; Vogelsberger, Mark; Torrey, Paul; Snyder, Gregory F.
2018-02-01
Modern large-scale cosmological simulations model the universe with increasing sophistication and at higher spatial and temporal resolutions. These ongoing enhancements permit increasingly detailed comparisons between the simulation outputs and real observational data. Recent projects such as Illustris are capable of producing simulated images that are designed to be comparable to those obtained from local surveys. This paper tests the degree to which Illustris achieves this goal across a diverse population of galaxies using visual morphologies derived from Galaxy Zoo citizen scientists. Morphological classifications provided by these volunteers for simulated galaxies are compared with similar data for a compatible sample of images drawn from the Sloan Digital Sky Survey (SDSS) Legacy Survey. This paper investigates how simple morphological characterization by human volunteers asked to distinguish smooth from featured systems differs between simulated and real galaxy images. Significant differences are identified, which are most likely due to the limited resolution of the simulation, but which could be revealing real differences in the dynamical evolution of populations of galaxies in the real and model universes. Specifically, for stellar masses {M}\\star ≲ {10}11 {M}ȯ , a substantially larger proportion of Illustris galaxies that exhibit disk-like morphology or visible substructure, relative to their SDSS counterparts. Toward higher masses, the visual morphologies for simulated and observed galaxies converge and exhibit similar distributions. The stellar mass threshold indicated by this divergent behavior confirms recent works using parametric measures of morphology from Illustris simulated images. When {M}\\star ≳ {10}11 {M}ȯ , the Illustris data set contains substantially fewer galaxies that classifiers regard as unambiguously featured. In combination, these results suggest that comparison between the detailed properties of observed and simulated galaxies, even when limited to reasonably massive systems, may be misleading.
Pan, Lei; Dumoncel, Jean; de Beer, Frikkie; Hoffman, Jakobus; Thackeray, John Francis; Duployer, Benjamin; Tenailleau, Christophe; Braga, José
2016-07-01
The appearance of the earliest members of the genus Homo in South Africa represents a key event in human evolution. Although enamel thickness and enamel dentine junction (EDJ) morphology preserve important information about hominin systematics and dietary adaptation, these features have not been sufficiently studied with regard to early Homo. We used micro-CT to compare enamel thickness and EDJ morphology among the mandibular postcanine dentitions of South African early hominins (N = 30) and extant Homo sapiens (N = 26), with special reference to early members of the genus Homo. We found that South African early Homo shows a similar enamel thickness distribution pattern to modern humans, although three-dimensional average and relative enamel thicknesses do not distinguish australopiths, early Homo, and modern humans particularly well. Based on enamel thickness distributions, our study suggests that a dietary shift occurred between australopiths and the origin of the Homo lineage. We also observed that South African early Homo postcanine EDJ combined primitive traits seen in australopith molars with derived features observed in modern human premolars. Our results confirm that some dental morphological patterns in later Homo actually occurred early in the Homo lineage, and highlight the taxonomic value of premolar EDJ morphology in hominin species. Copyright © 2016 Elsevier Ltd. All rights reserved.
Aeolian Rat Tails (ARTs): A New Morphological Indicator of Abrasion Direction
NASA Astrophysics Data System (ADS)
Favaro, E. A.; Hugenholtz, C.; Barchyn, T.
2016-12-01
Aeolian rat tails (ARTs) are a previously undocumented aeolian abrasion feature observed on ignimbrite surfaces in the Puna Plateau of Northwest Argentina and bare morphological similarity to small-scale features on Mars. We describe the terrestrial features and present an evolutionary sequence from inception to demise. ARTs are regionally-ubiquitous and characterized by a windward abrasion-resistant lithic clast and a downwind-tapering tail. The size of ARTs is controlled by the diameter of the windward lithic clast, observed on the sub-decimeter to meter scale. Their distribution throughout the Campo de Piedra Pómez, and adjacent regions is determined by the ignimbrite clast content. ARTs develop under a uni-modal abrasion direction when lithic clasts are eroded out of the ignimbrite matrix, protrude from the surface, and shelter material directly behind the clast. As the surrounding material is eroded away, a downwind-tapered tail develops. Continued erosion of the adjacent surface leads to the undercutting of clasts, liberating them from the feature where, if small enough, the clasts can be transported downwind, leading to the destruction of the tail and ultimately the feature. This evolutionary sequence accounts not only for the morphology of the feature, but also the presence of loose clasts on the ignimbrite surface, which plays a role in the development of other enigmatic landforms in the area, such as periodic bedrock ridges, yardangs, and megaripples. The significance of the identification of ARTs is due to the necessity of uni-modal abrasion direction for their development, thereby making their orientation a diagnostic indicator of long-term aeolian abrasion direction. ARTs are likely analogs of features identified by MSL Curiosity Rover on Mars, possibly providing information on past and present wind regimes.
Reyda, Florian B.; Marques, Fernando P. L.
2011-01-01
Background Neotropical freshwater stingrays (Batoidea: Potamotrygonidae) host a diverse parasite fauna, including cestodes. Both cestodes and their stingray hosts are marine-derived, but the taxonomy of this host/parasite system is poorly understood. Methodology Morphological and molecular (Cytochrome oxidase I) data were used to investigate diversity in freshwater lineages of the cestode genus Rhinebothrium Linton, 1890. Results were based on a phylogenetic hypothesis for 74 COI sequences and morphological analysis of over 400 specimens. Cestodes studied were obtained from 888 individual potamotrygonids, representing 14 recognized and 18 potentially undescribed species from most river systems of South America. Results Morphological species boundaries were based mainly on microthrix characters observed with scanning electron microscopy, and were supported by COI data. Four species were recognized, including two redescribed (Rhinebothrium copianullum and R. paratrygoni), and two newly described (R. brooksi n. sp. and R. fulbrighti n. sp.). Rhinebothrium paranaensis Menoret & Ivanov, 2009 is considered a junior synonym of R. paratrygoni because the morphological features of the two species overlap substantially. The diagnosis of Rhinebothrium Linton, 1890 is emended to accommodate the presence of marginal longitudinal septa observed in R. copianullum and R. brooksi n. sp. Patterns of host specificity and distribution ranged from use of few host species in few river basins, to use of as many as eight host species in multiple river basins. Significance The level of intra-specific morphological variation observed in features such as total length and number of proglottids is unparalleled among other elasmobranch cestodes. This is attributed to the large representation of host and biogeographical samples. It is unclear whether the intra-specific morphological variation observed is unique to this freshwater system. Nonetheless, caution is urged when using morphological discontinuities to delimit elasmobranch cestode species because the amount of variation encountered is highly dependent on sample size and/or biogeographical representation. PMID:21857936
NASA Astrophysics Data System (ADS)
Knight, Matthew M.; Schleicher, David G.
2014-11-01
We will present preliminary results from recent and upcoming imaging campaigns of four comets using Lowell Observatory’s 4.3-m Discovery Channel Telescope, 42-in Hall Telescope, and/or 31-in telescope: 1. Observations of C/ISON (2012 S1) were carried out from January through November 2013. A small, sunward fan was detected in dust images acquired in March, April, May, and September. Two faint CN features approximately orthogonal to the tail appeared on November 1 and were visible until our final night of data on November 12. This significantly predates their first reported appearance in broadband images on November 14 (Boehnhard et al., CBET 3715; Ye et al., CBET 3718) and suggests that the features were not caused by a catastrophic disruption of the nucleus at that time.2. We observed C/Pan-STARRS (2012 K1) regularly from October 2013 through June 2014 when it entered solar conjunction. Enhanced CN images in May and June 2014 exhibited a side-on pinwheel morphology that varied from night to night; similar morphology was not seen in concurrent dust images. Analysis of the rotation period is underway. 3. C/Jacques (2014 E2) was observed in April, May, and August 2014, and additional observations are scheduled through September 2014. After enhancement of the August images, Jacques exhibited two side-on CN corkscrews roughly orthogonal to the tail. The CN morphology was different from night to night but did not vary noticeably during ~1 hr of observations on a given night. Jacques also exhibited a smaller sunward dust feature in August that did not appear to vary during the observations. We will combine these data with our scheduled observations to investigate periodicity and compare the spatial distribution of multiple gas species. 4. Observations of C/Siding Spring (2013 A1) are scheduled around its close approach to Mars on October 19, 2014. This work is supported by NASA’s Planetary Astronomy Program grants NNX09AB51G and NNX11AD95G.
Buckling of paramagnetic chains in soft gels
NASA Astrophysics Data System (ADS)
Huang, Shilin; Pessot, Giorgio; Cremer, Peet; Weeber, Rudolf; Holm, Christian; Nowak, Johannes; Odenbach, Stefan; Menzel, Andreas M.; Auernhammer, Günter K.
We study the magneto-elastic coupling behavior of paramagnetic chains in soft polymer gels exposed to external magnetic fields. To this end, a laser scanning confocal microscope is used to observe the morphology of the paramagnetic chains together with the deformation field of the surrounding gel network. The paramagnetic chains in soft polymer gels show rich morphological shape changes under oblique magnetic fields, in particular a pronounced buckling deformation. The details of the resulting morphological shapes depend on the length of the chain, the strength of the external magnetic field, and the modulus of the gel. Based on the observation that the magnetic chains are strongly coupled to the surrounding polymer network, a simplified model is developed to describe their buckling behavior. A coarse-grained molecular dynamics simulation model featuring an increased matrix stiffness on the surfaces of the particles leads to morphologies in agreement with the experimentally observed buckling effects.
Morphology and mechanisms of picosecond ablation of metal films on fused silica substrates
NASA Astrophysics Data System (ADS)
Bass, Isaac L.; Negres, Raluca A.; Stanion, Ken; Guss, Gabe; Keller, Wesley J.; Matthews, Manyalibo J.; Rubenchik, Alexander M.; Yoo, Jae Hyuck; Bude, Jeffrey D.
2016-12-01
The ablation of magnetron sputtered metal films on fused silica substrates by a 1053 nm, picosecond class laser was studied as part of a demonstration of its use for in-situ characterization of the laser spot under conditions commonly used at the sample plane for laser machining and damage studies. Film thicknesses were 60 and 120 nm. Depth profiles and SEM images of the ablation sites revealed several striking and unexpected features distinct from those typically observed for ablation of bulk metals. Very sharp thresholds were observed for both partial and complete ablation of the films. Partial film ablation was largely independent of laser fluence with a surface smoothness comparable to that of the unablated surface. Clear evidence of material displacement was seen at the boundary for complete film ablation. These features were common to a number of different metal films including Inconel on commercial neutral density filters, stainless steel, and aluminum. We will present data showing the morphology of the ablation sites on these films as well as a model of the possible physical mechanisms producing the unique features observed.
Repeatability of the Dust and Gas Morphological Structures in the Coma of Comet
NASA Astrophysics Data System (ADS)
Lejoly, Cassandra; Samarasinha, N. H.; Ojha, L.; Schleicher, D. G.
2013-10-01
Comet 1P/Halley is the most famous comet in history and has been observed for over two millennia, making it one of the most extensively studied comets. The morphology in the coma of comet 1P/Halley originates due to the activity at the nucleus and could be used as a probe of the nuclear rotation and the activity. We will present the results from a study summarizing the evolution of coma morphology of comet 1P/Halley observed from ground between October 1985 and June 1986. The results to be presented include analysis of dust features as well as gas (CN) features in the coma and comparisons will be made between their spatial and temporal evolution. About 80 CN images and 300 continuum images from the Small Bodies Node of the NASA Planetary Data System were analyzed using image enhancement techniques that were not available n the 1980s. This enables us to see coma structure never observed before in comet 1P/Halley. Because of the comet's proximity to Earth, most of our best signal-to-noise images were taken in the March-April interval of 1986. Despite the limited coverage of preceding and following months, there is a sufficient number of images to monitor morphological evolution over many months. The initial synodic periods as a function of time used to phase the images together were extrapolated from the lightcurves of the active coma (Schleicher et al. 1990, AJ, 100, 896-912). We will present the periods of repeatability of individual coma features measured using the position angle at different spatial distances from the nucleus in adjacent cycles. Separate features appear to have slightly different periods of repeatability, perhaps depending on the corresponding source regions on the nucleus and/or projection effects. The periods of repeatability of coma morphologies will be presented as a function of time from the perihelion. These results will ultimately be used in detailed modeling of the coma morphologies of comet 1P/Halley over the 1985-1986 apparition in order to characterize the activity of the comet. This work is supported by NASA Planetary Atmospheres grant NNX11AD85G and C.L.'s participation at the meeting is supported by a gift to the Lunar and Planetary Laboratory at the University of Arizona.
NASA Astrophysics Data System (ADS)
Manrubia, S. C.; Prieto Ballesteros, O.; González Kessler, C.; Fernández Remolar, D.; Córdoba-Jabonero, C.; Selsis, F.; Bérczi, S.; Gánti, T.; Horváth, A.; Sik, A.; Szathmáry, E.
2004-03-01
We carry out a comparative analysis of the morphological and seasonal features of two regions in the Martian Southern Polar Region: the Inca City (82S 65W) and the Pityusa Patera zone (66S 37E). These two sites are representative of a large number of areas which are subjected to dynamical, seasonal processes that deeply modify the local conditions of those regions. Due to varitions in sunlight, seasonal CO2 accumulates during autumn and winter and starts defrosting in spring. By mid summer the seasonal ice has disappeared. Despite a number of relevant differences in the morphology of the seasonal features observed, they seem to result from similar processes.
Mars and earth - Comparison of cold-climate features
NASA Technical Reports Server (NTRS)
Lucchitta, B. K.
1981-01-01
On earth, glacial and periglacial features are common in areas of cold climate. On Mars, the temperature of the present-day surface is appropriate for permafrost, and the presence of water is suspected from data relating to the outgassing of the planet, from remote-sensing measurements over the polar caps and elsewhere on the Martian surface, and from recognition of fluvial morphological features such as channels. These observations and the possibility that ice could be in equilibrium with the high latitudes north and south of + or - 40 deg latitude suggest that glacial and periglacial features should exist on the planet. Morphological studies based mainly on Viking pictures indicate many features that can be attributed to the action of ice. Among these features are extensive talus aprons; debris avalanches; flows that resemble glaciers or rock glaciers; ridges that look like moraines; various types of patterned ground, scalloped scarps, and chaotically collapsed terrain that could be attributed to thermokarst processes; and landforms that may reflect the interaction of volcanism and ice.
The Importance of Chaos and Lenticulae on Europa for the JIMO Mission
NASA Technical Reports Server (NTRS)
Spaun, Nicole A.
2003-01-01
The Galileo Solid State Imaging (SSI) experiment provided high-resolution images of Europa's surface allowing identification of surface features barely distinguishable at Voyager's resolution. SSI revealed the visible pitting on Europa's surface to be due to large disrupted features, chaos, and smaller sub-circular patches, lenticulae. Chaos features contain a hummocky matrix material and commonly contain dislocated blocks of ridged plains. Lenticulae are morphologically interrelated and can be divided into three classes: domes, spots, and micro-chaos. Domes are broad, upwarped features that generally do not disrupt the texture of the ridged plains. Spots are areas of low albedo that are generally smooth in texture compared to other units. Micro-chaos are disrupted features with a hummocky matrix material, resembling that observed within chaos regions. Chaos and lenticulae are ubiquitous in the SSI regional map observations, which average approximately 200 meters per pixel (m/pxl) in resolution, and appear in several of the ultra-high resolution, i.e., better than 50 m/pxl, images of Europa as well. SSI also provided a number of multi-spectral observations of chaos and lenticulae. Using this dataset we have undertaken a thorough study of the morphology, size, spacing, stratigraphy, and color of chaos and lenticulae to determine their properties and evaluate models of their formation. Geological mapping indicates that chaos and micro-chaos have a similar internal morphology of in-situ degradation suggesting that a similar process was operating during their formation. The size distribution denotes a dominant size of 4-8 km in diameter for features containing hummocky material (i.e., chaos and micro-chaos). Results indicate a dominant spacing of 15 - 36 km apart. Chaos and lenticulae are generally among the youngest features stratigraphically observed on the surface, suggesting a recent change in resurfacing style. Also, the reddish non-icy materials on Europa's surface have high concentrations in many chaos and lenticulae features. Nonetheless, a complete global map of the distribution of chaos and lenticulae is not possible with the SSI dataset. Only <20% of the surface has been imaged at 200 m/pxl or better resolution, mostly of the near-equatorial regions. Color and ultra-high-res images have much less surface coverage. Thus we suggest that full global imaging of Europa at 200 m/pxl or better resolution, preferably in multi-spectral wavelengths, should be a high priority for the JIMO mission.
Morphological Feature Extraction for Automatic Registration of Multispectral Images
NASA Technical Reports Server (NTRS)
Plaza, Antonio; LeMoigne, Jacqueline; Netanyahu, Nathan S.
2007-01-01
The task of image registration can be divided into two major components, i.e., the extraction of control points or features from images, and the search among the extracted features for the matching pairs that represent the same feature in the images to be matched. Manual extraction of control features can be subjective and extremely time consuming, and often results in few usable points. On the other hand, automated feature extraction allows using invariant target features such as edges, corners, and line intersections as relevant landmarks for registration purposes. In this paper, we present an extension of a recently developed morphological approach for automatic extraction of landmark chips and corresponding windows in a fully unsupervised manner for the registration of multispectral images. Once a set of chip-window pairs is obtained, a (hierarchical) robust feature matching procedure, based on a multiresolution overcomplete wavelet decomposition scheme, is used for registration purposes. The proposed method is validated on a pair of remotely sensed scenes acquired by the Advanced Land Imager (ALI) multispectral instrument and the Hyperion hyperspectral instrument aboard NASA's Earth Observing-1 satellite.
The Geology of Inferno Chasm, Idaho: a Terrestrial Analog for Lunar Rilles?
NASA Technical Reports Server (NTRS)
Garry, William B.; Hughes, Scott S.; Kobs Nawotniak, Shannon E.; Neish, Catherine D.; Haberle, Christopher W.; Heldmann, Jennifer L.; Lim, Darlene S. S.
2014-01-01
Lunar sinuous rilles are thought to have formed by thermal erosion, mechanical erosion, construction, or a combination of these processes via emplacement by lava tubes or lava channels. The investigation of Hadley Rille by Apollo 15 provided the first field observations of a rille, but remote sensing observations remain our primary method for studying these features. Terrestrial volcanic features with similar morphologies to lunar rilles can provide insight into their formation on the Moon.
Khan, Raees; Ul Abidin, Sheikh Zain; Ahmad, Mushtaq; Zafar, Muhammad; Liu, Jie; Amina, Hafiza
2018-01-01
The present study is intended to assess gymnosperms pollen flora of Pakistan using Light Microscope (LM) and Scanning Electron Microscopy (SEM) for its taxonomic significance in identification of gymnosperms. Pollens of 35 gymnosperm species (12 genera and five families) were collected from its various distributional sites of gymnosperms in Pakistan. LM and SEM were used to investigate different palyno-morphological characteristics. Five pollen types (i.e., Inaperturate, Monolete, Monoporate, Vesiculate-bisaccate and Polyplicate) were observed. Six In equatorial view seven types of pollens were observed, in which ten species were sub-angular, nine species were Traingular, six species were Perprolate, three species were Rhomboidal, three species were semi-angular, two species were rectangular and two species were prolate. While five types of pollen were observed in polar view, in which ten species were Spheroidal, nine species were Angular, eight were Interlobate, six species were Circular, two species were Elliptic. Eighteen species has rugulate and 17 species has faveolate ornamentation. Eighteen species has verrucate and 17 have gemmate type sculpturing. The data was analysed through cluster analysis. The study showed that these palyno-morphological features have significance value in classification and identification of gymnosperms. Based on these different palyno-morphological features, a taxonomic key was proposed for the accurate and fast identifications of gymnosperms from Pakistan. © 2017 Wiley Periodicals, Inc.
In-vivo morphologic and spectroscopic investigation of Psoriasis
NASA Astrophysics Data System (ADS)
Kapsokalyvas, Dimitrios; Cicchi, Riccardo; Bruscino, Nicola; Alfieri, Domenico; Massi, Daniela; Lotti, Torello; Pavone, Francesco S.
2011-07-01
Psoriasis is an autoimmune disease of the skin characterized by hyperkeratosis, hyperproliferation of the epidermis, inflammatory cell accumulation and increased dilatation of dermal papillary blood vessels. Cases of psoriasis were investigated in vivo with optical means in order to evaluate the potential of in vivo optical biopsy. A Polarization Multispectral Dermoscope was employed for the macroscopic observation. Features such as the 'dotted' blood vessels pattern was observed with high contrast. High resolution image sections of the epidermis and the dermis were produced with a custom made Multiphoton Microscope. Imaging extended from the surface of the lesion down to the papillary dermis, at a depth of 200 μm. In the epidermis, a characteristic morphology of the stratum corneum found only in Psoriasis was revealed. Additionally, the cytoplasmic area of the cells in the stratum spinosum layer was found to be smaller than normal. In the dermis the morphological features were more pronounced, where the elongated dermal papillae dominated the papillary layer. Their length exceeds 100μm, which is a far greater value compared to that of healthy skin. These in vivo observations are consistent with the ex vivo histopathological observations, supporting both the applicability and potentiality of multispectral dermoscopy and multiphoton microscopy in the field of in vivo optical investigation and biopsy of skin.
Regional variations in the observed morphology and activity of martian linear gullies
NASA Astrophysics Data System (ADS)
Morales, Kimberly Marie; Diniega, Serina; Austria, Mia; Ochoa, Vincent; HiRISE Science and Instrument Team
2017-10-01
The formation mechanism for martian linear gullies has been much debated, because they have been suggested as possible evidence of liquid water on Mars. This class of dune gullies is defined by long (up to 2 km), narrow channels that are relatively uniform in width, and range in sinuosity index. Unlike other gullies on Earth and Mars that end in depositional aprons, linear gullies end in circular depressions referred to as terminal pits. This particular morphological difference, along with the difficulty of identifying a source of water to form these features, has led to several ‘dry’ hypotheses. Recent observations on the morphology, distribution, and present-day activity of linear gullies suggests that they could be formed by subliming blocks of seasonal CO2 ice (“dry ice”) sliding downslope on dune faces. In our study, we aimed to further constrain the possible mechanism(s) responsible for the formation of linear gullies by using HiRISE images to collect morphological data and track seasonal activity within three regions in the southern hemisphere-Hellespontus (~45°S, 40°E), Aonia Terra (~50°S, 290°E), and Jeans (~70°S, 155°E) over the last four Mars years. General similarities in these observations were reflective of the proposed formation process (sliding CO2 blocks) while differences were correlated with regional environmental conditions related to the latitude or general geologic setting. This presentation describes the observed regional differences in linear gully morphology and activity, and investigates how environmental factors such as surface properties and local levels of frost may explain these variations while still supporting the proposed model. Determining the formation mechanism that forms these martian features can improve our understanding of both the climatic and geological processes that shape the Martian surface.
Fast-moving features in the debris disk around AU Microscopii.
Boccaletti, Anthony; Thalmann, Christian; Lagrange, Anne-Marie; Janson, Markus; Augereau, Jean-Charles; Schneider, Glenn; Milli, Julien; Grady, Carol; Debes, John; Langlois, Maud; Mouillet, David; Henning, Thomas; Dominik, Carsten; Maire, Anne-Lise; Beuzit, Jean-Luc; Carson, Joseph; Dohlen, Kjetil; Engler, Natalia; Feldt, Markus; Fusco, Thierry; Ginski, Christian; Girard, Julien H; Hines, Dean; Kasper, Markus; Mawet, Dimitri; Ménard, François; Meyer, Michael R; Moutou, Claire; Olofsson, Johan; Rodigas, Timothy; Sauvage, Jean-Francois; Schlieder, Joshua; Schmid, Hans Martin; Turatto, Massimo; Udry, Stephane; Vakili, Farrokh; Vigan, Arthur; Wahhaj, Zahed; Wisniewski, John
2015-10-08
In the 1980s, excess infrared emission was discovered around main-sequence stars; subsequent direct-imaging observations revealed orbiting disks of cold dust to be the source. These 'debris disks' were thought to be by-products of planet formation because they often exhibited morphological and brightness asymmetries that may result from gravitational perturbation by planets. This was proved to be true for the β Pictoris system, in which the known planet generates an observable warp in the disk. The nearby, young, unusually active late-type star AU Microscopii hosts a well-studied edge-on debris disk; earlier observations in the visible and near-infrared found asymmetric localized structures in the form of intensity variations along the midplane of the disk beyond a distance of 20 astronomical units. Here we report high-contrast imaging that reveals a series of five large-scale features in the southeast side of the disk, at projected separations of 10-60 astronomical units, persisting over intervals of 1-4 years. All these features appear to move away from the star at projected speeds of 4-10 kilometres per second, suggesting highly eccentric or unbound trajectories if they are associated with physical entities. The origin, localization, morphology and rapid evolution of these features are difficult to reconcile with current theories.
Morphology of a Wetland Stream
Jurmu; Andrle
1997-11-01
/ Little attention has been paid to wetland stream morphology in the geomorphological and environmental literature, and in the recently expanding wetland reconstruction field, stream design has been based primarily on stream morphologies typical of nonwetland alluvial environments. Field investigation of a wetland reach of Roaring Brook, Stafford, Connecticut, USA, revealed several significant differences between the morphology of this stream and the typical morphology of nonwetland alluvial streams. Six morphological features of the study reach were examined: bankfull flow, meanders, pools and riffles, thalweg location, straight reaches, and cross-sectional shape. It was found that bankfull flow definitions originating from streams in nonwetland environments did not apply. Unusual features observed in the wetland reach include tight bends and a large axial wavelength to width ratio. A lengthy straight reach exists that exceeds what is typically found in nonwetland alluvial streams. The lack of convex bank point bars in the bends, a greater channel width at riffle locations, an unusual thalweg location, and small form ratios (a deep and narrow channel) were also differences identified. Further study is needed on wetland streams of various regions to determine if differences in morphology between alluvial and wetland environments can be applied in order to improve future designs of wetland channels.KEY WORDS: Stream morphology; Wetland restoration; Wetland creation; Bankfull; Pools and riffles; Meanders; Thalweg
Zabielska-Koczywąs, Katarzyna; Wojtkowska, Agata; Dolka, Izabella; Małek, Anna; Walewska, Magdalena; Wojtalewicz, Anna; Żbikowski, Artur; Lechowski, Roman
2017-06-26
The chick embryo chorioallantoic membrane (CAM) model is well described in human medicine as a cost-effective, easy to perform preclinical oncological model for observing pro- and antiangiogenic response, tumor biology and metastasis. The main objective of this article was to present the modification of the CAM assay in order to evaluate tumor growth from two feline fibrosarcoma cell lines (FFS1, FFS3) and describe their morphological and histopathological features. The authors described morphological and histopathological features of two feline fibrosarcoma cell lines (FFS1 and FFS3) grown on the CAM. Tumors from the FFS1 cell line showed high malignancy (grade III), while tumors from the FFS3 cell line were grade II. Proliferation markers (Ki-67 and PCNA) were determined and the positive correlation between PCNA and tumor grade (r = 0.8247; p < 0.001) was demonstrated, as opposed to Ki-67. The results obtained indicate that PCNA may be helpful to evaluate the tumor grade, better than Ki-67, for feline fibrosarcomas. However, further investigations of proliferation marker, in bigger number of feline spontaneous fibrosarcomas and feline fibrosarcomas grown on the CAM from different cell lines, are needed to confirm these observations.
Su, Y; Zhang, X; Wu, K; Ji, Y; Zuo, C; Li, M; Wen, F
2014-01-01
Purpose To investigate the morphological features of myopic maculopathy with a new and noninvasive retro-mode imaging (RMI) technique using a confocal scanning laser ophthalmoscope. Methods A total of 42 patients (69 eyes) with myopic maculopathy were included. RMI combined with fundus photography, fundus fluorescein angiography, and optical coherence tomography together were used to observe and evaluate the morphological features of disease. Results Four in 4 eyes (100%) with macular retinoschisis were found with a characteristic pattern by RMI (firework pattern centrally with surrounding fingerprint pattern). Twenty-four in 24 eyes (100%) with pigment proliferation were found by RMI as dark plain patches, and 23 in 24 eyes with hemorrhage (95.8%) were found by RMI as gray bump. Atrophy of different degrees (12 in 14 eyes, 85.7%) was found by RMI as an area of pseudo-3D choroidal vessels or a fuzzy shadow but both without a clear boundary. Choroidal neovascularization (12 in 16 eyes, 75%) was identified laboriously by RMI as a vague raised region. Lacquer cracks were difficult to figure out in RMI. Conclusions Retinoschisis, pigment proliferation, hemorrhage, and atrophy secondary to myopic maculopathy have characteristic morphologic features in RMI; however, choroidal neovascularization and lacquer crack are not easily distinguishable in RMI. PMID:24924440
Asseln, Malte; Hänisch, Christoph; Schick, Fabian; Radermacher, Klaus
2018-05-14
Morphological differences between female and male knees have been reported in the literature, which led to the development of so-called gender-specific implants. However, detailed morphological descriptions covering the entire joint are rare and little is known regarding whether gender differences are real sexual dimorphisms or can be explained by overall differences in size. We comprehensively analysed knee morphology using 33 features of the femur and 21 features of the tibia to quantify knee shape. The landmark recognition and feature extraction based on three-dimensional surface data were fully automatically applied to 412 pathological (248 female and 164 male) knees undergoing total knee arthroplasty. Subsequently, an exploratory statistical analysis was performed and linear correlation analysis was used to investigate normalization factors and gender-specific differences. Statistically significant differences between genders were observed. These were pronounced for distance measurements and negligible for angular (relative) measurements. Female knees were significantly narrower at the same depth compared to male knees. The correlation analysis showed that linear correlations were higher for distance measurements defined in the same direction. After normalizing the distance features according to overall dimensions in the direction of their definition, gender-specific differences disappeared or were smaller than the related confidence intervals. Implants should not be linearly scaled according to one dimension. Instead, features in medial/lateral and anterior/posterior directions should be normalized separately (non-isotropic scaling). However, large inter-individual variations of the features remain after normalization, suggesting that patient-specific design solutions are required for an improved implant design, regardless of gender. Copyright © 2018 Elsevier B.V. All rights reserved.
Fabrezi, Marissa; Lobo, Fernando
2009-11-01
Many traits of the skull of ceratophryines are related to the capture of large prey independently of aquatic or terrestrial feeding. Herein, detailed descriptions of the development of hyoid skeleton and the anatomy of muscles responsible for hyoid and tongue movements in Lepidobatrachus laevis and L. llanensis are provided and compared with those of other neobatrachians. The aquatic Lepidobatrachus has special features in its hyoid skeleton that integrates a set of derived features convergent with the conditions observed in non-neobatrachian anurans and morphological novelties (e.g., dorsal dermal hyoid ossification) that deviate from the generalized pattern found in most frogs. Further, reduction of fibers of muscles of buccal floor, reduction or loss of hyoid muscles (m. geniohyoideus rama lateralis, anterior pair of m. petrohyoideus posteriores), small tongue, and simplified tongue muscles are also morphological deviations from the pattern of terrestrial ceratophryines, and other aquatic ceratophryids (e.g., Telmatobius) that seem to be related to feeding underwater. The historical derived features shared with Chacophrys and Ceratophrys involved in megalophagy are conserved in Lepidobatrachus and morphological changes in the hyoglossal apparatus define a unique functional complex among anurans.
Local-Scale Simulations of Nucleate Boiling on Micrometer Featured Surfaces: Preprint
DOE Office of Scientific and Technical Information (OSTI.GOV)
Sitaraman, Hariswaran; Moreno, Gilberto; Narumanchi, Sreekant V
2017-08-03
A high-fidelity computational fluid dynamics (CFD)-based model for bubble nucleation of the refrigerant HFE7100 on micrometer-featured surfaces is presented in this work. The single-fluid incompressible Navier-Stokes equations, along with energy transport and natural convection effects are solved on a featured surface resolved grid. An a priori cavity detection method is employed to convert raw profilometer data of a surface into well-defined cavities. The cavity information and surface morphology are represented in the CFD model by geometric mesh deformations. Surface morphology is observed to initiate buoyancy-driven convection in the liquid phase, which in turn results in faster nucleation of cavities. Simulationsmore » pertaining to a generic rough surface show a trend where smaller size cavities nucleate with higher wall superheat. This local-scale model will serve as a self-consistent connection to larger device scale continuum models where local feature representation is not possible.« less
Local-Scale Simulations of Nucleate Boiling on Micrometer-Featured Surfaces
DOE Office of Scientific and Technical Information (OSTI.GOV)
Sitaraman, Hariswaran; Moreno, Gilberto; Narumanchi, Sreekant V
2017-07-12
A high-fidelity computational fluid dynamics (CFD)-based model for bubble nucleation of the refrigerant HFE7100 on micrometer-featured surfaces is presented in this work. The single-fluid incompressible Navier-Stokes equations, along with energy transport and natural convection effects are solved on a featured surface resolved grid. An a priori cavity detection method is employed to convert raw profilometer data of a surface into well-defined cavities. The cavity information and surface morphology are represented in the CFD model by geometric mesh deformations. Surface morphology is observed to initiate buoyancy-driven convection in the liquid phase, which in turn results in faster nucleation of cavities. Simulationsmore » pertaining to a generic rough surface show a trend where smaller size cavities nucleate with higher wall superheat. This local-scale model will serve as a self-consistent connection to larger device scale continuum models where local feature representation is not possible.« less
Observational Tests of the Mars Ocean Hypothesis: Selected MOC and MOLA Results
NASA Technical Reports Server (NTRS)
Parker, T. J.; Banerdt, W. B.
1999-01-01
We have begun a detailed analysis of the evidence for and topography of features identified as potential shorelines that have been im-aged by the Mars Orbiter Camera (MOC) during the Aerobraking Hiatus and Science Phasing Orbit periods of the Mars Global Surveyor (MGS) mission. MOC images, comparable in resolution to high-altitude terrestrial aerial photographs, are particularly well suited to address the morphological expressions of these features at scales comparable to known shore morphologies on Earth. Particularly useful are examples of detailed relationships between potential shore features, such as erosional (and depositional) terraces have been cut into "familiar" pre-existing structures and topography in a fashion that points to a shoreline interpretation as the most likely mechanism for their formation. Additional information is contained in the original extended abstract.
Anthropometric typology of male and female rowers using k-means clustering.
Forjasz, Justyna
2011-06-01
The aim of this paper is to present the morphological features of rowers. The objective is to establish the type of body build best suited to the present requirements of this sports discipline through the determination of the most important morphological features in rowing with regard to the type of racing boat. The subjects of this study included competitors who practise rowing and were members of the Junior National Team. The considered variables included a group of 32 anthropometric measurements of body composition determined using the BIA method among male and female athletes, while also including rowing boat categories. In order to determine the analysed structures of male and female rowers, an observation analysis was taken into consideration and performed by the k-means clustering method. In the group of male and female rowers using long paddles, higher mean values for the analysed features were observed, with the exception of fat-free mass, and water content in both genders, and trunk length and horizontal reach in women who achieved higher means in the short-paddle group. On the men's team, both groups differed significantly in body mass, longitudinal features, horizontal reach, hand width and body circumferences, while on the women's, they differed in body mass, width and length of the chest, body circumferences and fat content. The method of grouping used in this paper confirmed morphological differences in the competitors with regard to the type of racing boat.
Anthropometric Typology of Male and Female Rowers Using K-Means Clustering
Forjasz, Justyna
2011-01-01
The aim of this paper is to present the morphological features of rowers. The objective is to establish the type of body build best suited to the present requirements of this sports discipline through the determination of the most important morphological features in rowing with regard to the type of racing boat. The subjects of this study included competitors who practise rowing and were members of the Junior National Team. The considered variables included a group of 32 anthropometric measurements of body composition determined using the BIA method among male and female athletes, while also including rowing boat categories. In order to determine the analysed structures of male and female rowers, an observation analysis was taken into consideration and performed by the k-means clustering method. In the group of male and female rowers using long paddles, higher mean values for the analysed features were observed, with the exception of fat-free mass, and water content in both genders, and trunk length and horizontal reach in women who achieved higher means in the short-paddle group. On the men’s team, both groups differed significantly in body mass, longitudinal features, horizontal reach, hand width and body circumferences, while on the women’s, they differed in body mass, width and length of the chest, body circumferences and fat content. The method of grouping used in this paper confirmed morphological differences in the competitors with regard to the type of racing boat. PMID:23486287
Lee, Chung-Ta; Chow, Nan-Haw; Su, Pei-Fang; Ho, Chung-Liang; Tsai, Hung-Wen; Chen, Yi-Lin; Lin, Shao-Chieh; Lin, Bo-Wen; Lin, Peng-Chan; Lee, Jenq-Chang
2017-01-01
Colorectal mucinous adenocarcinoma (MAC) and serrated adenocarcinoma (SAC) share many characteristics, including right-side colon location, frequent mucin production, and various molecular features. This study examined the frequency of SAC morphology in MACs. We assessed the correlation of SAC morphology with clinicopathological parameters, molecular characteristics, and patient prognosis. Eighty-eight colorectal MACs were collected and reviewed for SAC morphology according to Makinen's criteria. We sequenced KRAS and BRAF, assessed CpG island methylator phenotype (CIMP) frequency, and analyzed DNA mismatch repair enzyme levels using immunohistochemistry in tumor samples. SAC morphology was observed in 38% of MACs, and was associated with proximal location (P=0.001), BRAF mutation (P=0.042), CIMP-positive status (P=0.023), and contiguous traditional serrated adenoma (P=0.019). Multivariate analysis revealed that MACs without both SAC morphology and CIMP-positive status exhibited 3.955 times greater risk of cancer relapse than MACs having both characteristics or either one (P=0.035). Our results show that two MAC groups with distinct features can be identified using Makinen's criteria, and suggest a favorable prognostic role for the serrated neoplastic pathway in colorectal MAC. PMID:28422723
[A research on real-time ventricular QRS classification methods for single-chip-microcomputers].
Peng, L; Yang, Z; Li, L; Chen, H; Chen, E; Lin, J
1997-05-01
Ventricular QRS classification is key technique of ventricular arrhythmias detection in single-chip-microcomputer based dynamic electrocardiogram real-time analyser. This paper adopts morphological feature vector including QRS amplitude, interval information to reveal QRS morphology. After studying the distribution of QRS morphology feature vector of MIT/BIH DB ventricular arrhythmia files, we use morphological feature vector cluster to classify multi-morphology QRS. Based on the method, morphological feature parameters changing method which is suitable to catch occasional ventricular arrhythmias is presented. Clinical experiments verify missed ventricular arrhythmia is less than 1% by this method.
Sarah Wilkinson; Jerome Ogee; Jean-Christophe Domec; Mark Rayment; Lisa Wingate
2015-01-01
Process-based models that link seasonally varying environmental signals to morphological features within tree rings are essential tools to predict tree growth response and commercially important wood quality traits under future climate scenarios. This study evaluated model portrayal of radial growth and wood anatomy observations within a mature maritime pine (Pinus...
How normal is the transparent cornea? Effects of aging on corneal morphology.
Hillenaar, Toine; van Cleynenbreugel, Hugo; Remeijer, Lies
2012-02-01
To ascertain the effects of aging on corneal morphology and to illustrate the morphologic diversity of the different layers in the normal cornea as seen by in vivo confocal microscopy (IVCM). Observational cross-sectional study. A total of 150 healthy subjects, evenly distributed over 5 age categories, comprising 75 men and 75 women. Both transparent corneas (n = 300) of all subjects were examined in duplicate by white light IVCM (Confoscan 4, NIDEK Technologies, Albignasego, Padova, Italy). After reviewing the IVCM examinations for morphologic variations of the corneal layers, we selected the 8 most common features to illustrate the morphologic diversity. Subsequently, all 600 IVCM examinations were assessed for the presence of these features. We used binary logistic regression analyses to assess the age-relatedness of each feature. Age distribution of bright superficial epithelial cells, dendriform cells, alterations characteristic of epithelial basement membrane dystrophy (EBMD), tortuous stromal nerves, stromal microdots in the anterior stroma, folds in the posterior stroma, opacification of Descemet's membrane, and corneal guttae. Four features were found characteristic of the aging cornea: stromal microdots in the anterior stroma (P<0.0001), folds in the posterior stroma (P<0.0001), opacification of Descemet's membrane (P<0.0001), and corneal guttae (P<0.0001). Alterations characteristic of EBMD were found in 3% of all eyes and only detected in subjects aged ≥40 years, suggesting age-relatedness (P = 0.09). Other features, such as bright superficial epithelial cells (n = 38, 13%), dendriform cells (n = 42, 14%), and tortuous stromal nerves (n = 115, 38%), were age-independent. We also found a novel phenotype of corneal endothelium in 4 normal eyes of 2 subjects, which we coined "salt and pepper endothelium." We could not establish whether this novel phenotype represented a morphologic variant of normal endothelium, an early stage of a known corneal endothelial disorder, or a completely new disease entity. Knowledge of the common morphologic variations of the corneal layers and the effects of aging on corneal morphology as seen by IVCM increases our understanding of corneal degenerative disorders and is essential to detect corneal pathology. Our finding of a novel phenotype of corneal endothelium emphasizes the morphologic diversity of this optically transparent tissue. Copyright © 2012 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.
Coma morphology of comet 67P controlled by insolation over irregular nucleus
NASA Astrophysics Data System (ADS)
Shi, X.; Hu, X.; Mottola, S.; Sierks, H.; Keller, H. U.; Rose, M.; Güttler, C.; Fulle, M.; Fornasier, S.; Agarwal, J.; Pajola, M.; Tubiana, C.; Bodewits, D.; Barbieri, C.; Lamy, P. L.; Rodrigo, R.; Koschny, D.; Barucci, M. A.; Bertaux, J.-L.; Bertini, I.; Boudreault, S.; Cremonese, G.; Da Deppo, V.; Davidsson, B.; Debei, S.; De Cecco, M.; Deller, J.; Groussin, O.; Gutiérrez, P. J.; Hviid, S. F.; Ip, W.-H.; Jorda, L.; Knollenberg, J.; Kovacs, G.; Kramm, J.-R.; Kührt, E.; Küppers, M.; Lara, L. M.; Lazzarin, M.; Lopez-Moreno, J. J.; Marzari, F.; Naletto, G.; Oklay, N.; Toth, I.; Vincent, J.-B.
2018-05-01
While the structural complexity of cometary comae is already recognizable from telescopic observations1, the innermost region, within a few radii of the nucleus, was not resolved until spacecraft exploration became a reality2,3. The dust coma displays jet-like features of enhanced brightness superposed on a diffuse background1,4,5. Some features can be traced to specific areas on the nucleus, and result conceivably from locally enhanced outgassing and/or dust emission6-8. However, diffuse or even uniform activity over topographic concavity can converge to produce jet-like features9,10. Therefore, linking observed coma morphology to the distribution of activity on the nucleus is difficult11,12. Here, we study the emergence of dust activity at sunrise on comet 67P/Churyumov-Gerasimenko using high-resolution, stereo images from the OSIRIS camera onboard the Rosetta spacecraft, where the sources and formation of the jet-like features are resolved. We perform numerical simulations to show that the ambient dust coma is driven by pervasive but non-uniform water outgassing from the homogeneous surface layer. Physical collimations of gas and dust flows occur at local maxima of insolation and also via topographic focusing. Coma structures are projected to exhibit jet-like features that vary with the perspective of the observer. For an irregular comet such as 67P/Churyumov-Gerasimenko, near-nucleus coma structures can be concealed in the shadow of the nucleus, which further complicates the picture.
Wu, Guorong; Kim, Minjeong; Wang, Qian; Munsell, Brent C.
2015-01-01
Feature selection is a critical step in deformable image registration. In particular, selecting the most discriminative features that accurately and concisely describe complex morphological patterns in image patches improves correspondence detection, which in turn improves image registration accuracy. Furthermore, since more and more imaging modalities are being invented to better identify morphological changes in medical imaging data,, the development of deformable image registration method that scales well to new image modalities or new image applications with little to no human intervention would have a significant impact on the medical image analysis community. To address these concerns, a learning-based image registration framework is proposed that uses deep learning to discover compact and highly discriminative features upon observed imaging data. Specifically, the proposed feature selection method uses a convolutional stacked auto-encoder to identify intrinsic deep feature representations in image patches. Since deep learning is an unsupervised learning method, no ground truth label knowledge is required. This makes the proposed feature selection method more flexible to new imaging modalities since feature representations can be directly learned from the observed imaging data in a very short amount of time. Using the LONI and ADNI imaging datasets, image registration performance was compared to two existing state-of-the-art deformable image registration methods that use handcrafted features. To demonstrate the scalability of the proposed image registration framework image registration experiments were conducted on 7.0-tesla brain MR images. In all experiments, the results showed the new image registration framework consistently demonstrated more accurate registration results when compared to state-of-the-art. PMID:26552069
Wu, Guorong; Kim, Minjeong; Wang, Qian; Munsell, Brent C; Shen, Dinggang
2016-07-01
Feature selection is a critical step in deformable image registration. In particular, selecting the most discriminative features that accurately and concisely describe complex morphological patterns in image patches improves correspondence detection, which in turn improves image registration accuracy. Furthermore, since more and more imaging modalities are being invented to better identify morphological changes in medical imaging data, the development of deformable image registration method that scales well to new image modalities or new image applications with little to no human intervention would have a significant impact on the medical image analysis community. To address these concerns, a learning-based image registration framework is proposed that uses deep learning to discover compact and highly discriminative features upon observed imaging data. Specifically, the proposed feature selection method uses a convolutional stacked autoencoder to identify intrinsic deep feature representations in image patches. Since deep learning is an unsupervised learning method, no ground truth label knowledge is required. This makes the proposed feature selection method more flexible to new imaging modalities since feature representations can be directly learned from the observed imaging data in a very short amount of time. Using the LONI and ADNI imaging datasets, image registration performance was compared to two existing state-of-the-art deformable image registration methods that use handcrafted features. To demonstrate the scalability of the proposed image registration framework, image registration experiments were conducted on 7.0-T brain MR images. In all experiments, the results showed that the new image registration framework consistently demonstrated more accurate registration results when compared to state of the art.
NASA Astrophysics Data System (ADS)
Shi, Wenzhong; Deng, Susu; Xu, Wenbing
2018-02-01
For automatic landslide detection, landslide morphological features should be quantitatively expressed and extracted. High-resolution Digital Elevation Models (DEMs) derived from airborne Light Detection and Ranging (LiDAR) data allow fine-scale morphological features to be extracted, but noise in DEMs influences morphological feature extraction, and the multi-scale nature of landslide features should be considered. This paper proposes a method to extract landslide morphological features characterized by homogeneous spatial patterns. Both profile and tangential curvature are utilized to quantify land surface morphology, and a local Gi* statistic is calculated for each cell to identify significant patterns of clustering of similar morphometric values. The method was tested on both synthetic surfaces simulating natural terrain and airborne LiDAR data acquired over an area dominated by shallow debris slides and flows. The test results of the synthetic data indicate that the concave and convex morphologies of the simulated terrain features at different scales and distinctness could be recognized using the proposed method, even when random noise was added to the synthetic data. In the test area, cells with large local Gi* values were extracted at a specified significance level from the profile and the tangential curvature image generated from the LiDAR-derived 1-m DEM. The morphologies of landslide main scarps, source areas and trails were clearly indicated, and the morphological features were represented by clusters of extracted cells. A comparison with the morphological feature extraction method based on curvature thresholds proved the proposed method's robustness to DEM noise. When verified against a landslide inventory, the morphological features of almost all recent (< 5 years) landslides and approximately 35% of historical (> 10 years) landslides were extracted. This finding indicates that the proposed method can facilitate landslide detection, although the cell clusters extracted from curvature images should be filtered using a filtering strategy based on supplementary information provided by expert knowledge or other data sources.
Zagaja, Mirosław; Staniec, Bernard; Pietrykowska-Tudruj, Ewa
2014-03-07
This article for the first time presents the morphology of the egg, three larval instars, pupal cocoon, prepupa and pupa of myrmecophilous rove beetle Thiasophila angulata (Erichson, 1837) along with illustrations of structural features and chaetotaxy. Morphological comparisons are made between larval instars, and between the mature larva of T. angulata and other known larvae of Aleocharinae belonging to the tribes Athetini, Hoplandriini, Liparocephalini, Lomechusinii and Oxypodini. Pupae of T. angulata and two other species of Aleocharinae: Pella laticollis (Märkell, 1844) and Haploglossa picipennis (Gyllenhal, 1827) are compared. The mature larvae of T. angulata were observed to vary morphologically depending on the ant host species (Formica polyctena, F. rufa or F. truncorum). Host-related variation was observed in median larval body length, head and pronotum width and structure of the antennae.
NASA Astrophysics Data System (ADS)
Tin, Tina
Antarctic sea ice thickness data obtained from drilling on sea ice floes were examined with the goal of enhancing our capability to estimate ice thickness remotely, especially from air- or space-borne altimetry and shipboard visual observations. The state of hydrostatic equilibrium of deformed ice features and the statistical relationships between ice thickness and top surface roughness were examined. Results indicate that ice thickness may be estimated fairly reliably from surface measurements of snow elevation on length scales of ≥100 m. Examination of the morphology of deformed ice features show that Antarctic pressure ridges are flatter and less massive than Arctic pressure ridges and that not all surface features (ridge sails) are associated with features underwater (ridge keels). I propose that the differences in morphology are due to differences in sampling strategies, parent ice characteristics and the magnitude and duration of driving forces. As a result of these findings, the existing methodology used to estimate ice thickness from shipboard visual observations was modified to incorporate the probability that a sail is associated with a keel underwater, and the probability that keels may be found under level surfaces. Using the improved methodology, ice thickness was estimated from ship observations data obtained during two cruises in the Ross Sea, Antarctica. The dynamic and thermodynamic processes involved in the development of the ice prior to their observation were examined employing a regional sea ice-mixed layer-pycnocline model. Both our model results and previously published ice core data indicate that thermodynamic thickening is the dominant process that determines the thickness of first year ice in the central Ross Sea, although dynamic thickening also plays a significant role. Ice core data also indicate that snow ice forms a significant proportion of the total ice mass. For ice in the northeast Ross Sea in the summer, model results and evidence from ice core and oceanographic data indicate that dynamic thickening, snow ice formation and bottom melting compete to determine the ice thickness during mid and late winter.
Ibargüengoytía, N R; Pastor, L M; Pallares, J
1999-04-01
Adult males of Testudo graeca were used to preliminarily study the light microscopic morphology and the ultrastructure of the testes. Spermiogenesis has shown the presence of some interspecific variations among Chelonia, while the general features of the testes and spermatocytes are morphologically similar to other reptilians. The male reproductive state observed in the months analysed has shown spermatogenesis recrudescence in spring, a complete germinal series in autumn and testicular regression in winter. The observation of ultrastructural features, characteristic of steroidogenic activity, suggests a synchrony in tubular and interstitial compartments in T. graeca, with little steroidogenic activity in winter and active synthesis in spring and autumn. In conclusion, the results of this histological study suggest a probable asynchrony between the male and female reproductive cycle in this species and show synchrony in the steroidogenic activity of Sertoli and Leydig cells.
In situ ESEM imaging of the vapor-pressure-dependent sublimation-induced morphology of ice
NASA Astrophysics Data System (ADS)
Nair, Malavika; Husmann, Anke; Cameron, Ruth E.; Best, Serena M.
2018-04-01
Sublimation is a fundamental phase transition that has a profound impact on both natural phenomena and advanced manufacturing technologies. Although great strides have been made in the study of ice growth from melt and vapor, little consideration has been given to the effect of sublimation on the morphological features that develop in the ice microstructure. In this experimental study, we demonstrate the effect of vapor pressure on the mesoscopic faceting observed and show that a vapor-pressure-specific wavelength characterizes the periodic features that arise during sublimation. The ability to control the length scale of these features not only provides us with new insights into the mesoscopic roughness of ice crystals, but also presents the potential to exploit this effect in a plethora of applications from comet dating to ice-templated tissue engineering scaffolds.
Differences in dissolved cadmium and zinc uptake among stream insects: Mechanistic explanations
Buchwalter, D.B.; Luoma, S.N.
2005-01-01
This study examined the extent to which dissolved Cd and Zn uptake rates vary in several aquatic insect taxa commonly used as indicators of ecological health. We further attempted to explain the mechanisms underlying observed differences. By comparing dissolved Cd and Zn uptake rates in several aquatic insect species, we demonstrated that species vary widely in these processes. Dissolved uptake rates were not related to gross morphological features such as body size or gill size-features that influence water permeability and therefore have ionoregulatory importance. However, finer morphological features, specifically, the relative numbers of ionoregulatory cells (chloride cells), appeared to be related to dissolved metal uptake rates. This observation was supported by Michaelis-Menten type kinetics experiments, which showed that dissolved Cd uptake rates were driven by the numbers of Cd transporters and not by the affinities of those transporters to Cd. Calcium concentrations in exposure media similarly affected Cd and Zn uptake rates in the caddisfly Hydropsyche californica. Dissolved Cd and Zn uptake rates strongly co-varied among species, suggesting that these metals are transported by similar mechanisms.
Phylogeny and systematics of deep-sea precious corals (Anthozoa: Octocorallia: Coralliidae).
Tu, Tzu-Hsuan; Dai, Chang-Feng; Jeng, Ming-Shiou
2015-03-01
The phylogeny of Coralliidae is being increasingly studied to elucidate their evolutionary history and species delimitation due to global concerns about their conservation. Previous studies on phylogenetic relationships within Coralliidae have pointed out that the two currently recognized genera are not monophyletic and the Coralliidae should be divided into three genera. In order to provide a comprehensive revision of the taxonomy of Coralliidae, we documented 110 specimens using eight mitochondrial and one nuclear loci to reconstruct their phylogeny. The morphological features of 27 type specimens were also examined. Phylogenetic relationships based on both mitochondrial and nuclear markers revealed two reciprocally monophyletic clades of Coralliidae. One of the clades was further split into two subclades with respect to sequence variation and observable morphological features. Based on the results of genealogical analyses and distinctive morphological features, the three genera classification of Coralliidae proposed by Gray (1867) was redefined. In this revised taxonomic system, Corallium, Hemicorallium, and Pleurocorallium consist of 7, 16 and 14 species, respectively. Our results also showed that the cosmopolitan Hemicorallium laauense is a species complex containing a cryptic species. Copyright © 2015 Elsevier Inc. All rights reserved.
Applications of Computed Tomography to Evaluate Cellular Solid Interfaces
NASA Technical Reports Server (NTRS)
Maisano, Josephine; Marse, Daryl J.; Schilling, Paul J.
2008-01-01
The major morphological features - foam cells, voids, knit lines, and the bondline interface were evaluated. The features identified by micro-CT correlate well to those observed by SEM. 3D reconstructions yielded volumetric dimensions for large voids (max 30 mm). Internal voids and groupings of smaller cells at the bondline are concluded to be the cause of the indications noted during the NDE prescreening process.
Lunar volcanism in space and time
DOE Office of Scientific and Technical Information (OSTI.GOV)
Head, J.W. III
1976-05-01
Data obtained from lunar orbit and earth-based observations were used to extend the detailed characterizations derived from Apollo and Luna sample return missions to other parts of the moon. Lunar mare and highland volcanism are described including the distribution, volcanic features, the relation of mare morphologic features to the style of volcanic eruption, the characteristics and ages of other mare deposits, and sample results. (JFP)
Putative Indigenous Carbon-Bearing Alteration Features in Martian Meteorite Yamato 000593
Gibson, Everett K.; Thomas-Keprta, Kathie L.; Clemett, Simon J.; McKay, David S.
2014-01-01
Abstract We report the first observation of indigenous carbonaceous matter in the martian meteorite Yamato 000593. The carbonaceous phases are heterogeneously distributed within secondary iddingsite alteration veins and present in a range of morphologies including areas composed of carbon-rich spheroidal assemblages encased in multiple layers of iddingsite. We also observed microtubular features emanating from iddingsite veins penetrating into the host olivine comparable in shape to those interpreted to have formed by bioerosion in terrestrial basalts. Key Words: Meteorite—Yamato 000593—Mars—Carbon. Astrobiology 14, 170–181. PMID:24552234
Groundwater sapping channels: Summary of effects of experiments with varied stratigraphy
NASA Technical Reports Server (NTRS)
Kochel, R. Craig; Simmons, David W.
1987-01-01
Experiments in the recirculating flume sapping box have modeled valley formation by groundwater sapping processes in a number of settings. The effects of the following parameters on sapping channel morphology were examined: surface slope; stratigraphic variations in permeability cohesion and dip; and structure of joints and dikes. These kinds of modeling experiments are particularly good for: testing concepts; developing a suite of distinctive morphologies and morphometries indicative of sapping; helping to relate process to morphology; and providing data necessary to assess the relative importance of runoff, sapping, and mass wasting processes on channel development. The observations from the flume systems can be used to help interpret features observed in terrestrial and Martian settings where sapping processes are thought to have played an important role in the development of valley networks.
Pervasive influence of idiosyncratic associative biases during facial emotion recognition.
El Zein, Marwa; Wyart, Valentin; Grèzes, Julie
2018-06-11
Facial morphology has been shown to influence perceptual judgments of emotion in a way that is shared across human observers. Here we demonstrate that these shared associations between facial morphology and emotion coexist with strong variations unique to each human observer. Interestingly, a large part of these idiosyncratic associations does not vary on short time scales, emerging from stable inter-individual differences in the way facial morphological features influence emotion recognition. Computational modelling of decision-making and neural recordings of electrical brain activity revealed that both shared and idiosyncratic face-emotion associations operate through a common biasing mechanism rather than an increased sensitivity to face-associated emotions. Together, these findings emphasize the underestimated influence of idiosyncrasies on core social judgments and identify their neuro-computational signatures.
Centimeter to Decimeter Size Spherical and Cylindrical Features in Gale Crater Sediments
NASA Technical Reports Server (NTRS)
Wiens, R. C.; Maurice, S.; Gasnault, O.; Clegg, S.; Fabre, C.; Nachon, M.; Rubin, D.; Goetz, W.; Mangold, N.; Schroeder, S.;
2015-01-01
The Curiosity rover traverse in Gale crater has explored a large series of sedimentary deposits in an ancient lake on Mars. Over the nine kilometers of traverse a recurrent observation has been southward-dipping sedimentary strata, from Shaler at the edge of Yellowknife Bay to the striated units near the Kimberley. Within the sedimentary strata cm- to decimeter- size hollow spheroidal objects and some apparent cylindrical objects have been observed. These features have not been seen by previous landed missions. The first of these were observed on sol 122 in the Gillespie Lake member at Yellowknife Bay. Additional hollow features were observed in the Point Lake outcrop in the same area. More recently a spherical and apparently hollow object, Winnipesaukee, was observed by ChemCam and Mastcam on sol 653. Here we describe the settings, morphology, and associated compositions, and we discuss possible origins of these objects.
The crustal structure of the Enderby Basin, East Antarctica
NASA Astrophysics Data System (ADS)
Davis, Joshua K.; Lawver, Lawrence A.; Norton, Ian O.; Dalziel, Ian W. D.; Gahagan, Lisa M.
2018-05-01
The passive margin and ocean crust of the Enderby Basin, East Antarctica preserves a record of the breakup of East Gondwana. Using a suite of public domain geophysical data, we have examined and described the crustal morphology of the basin. Based on our geophysical observations, we divide the Enderby Basin into three distinct morphologic domains. The Eastern Domain demonstrates the most volcanic morphology of the basin, with abundant seaward dipping reflector packages and anomalously thick oceanic crust. These features suggest an early influence by the Kerguelen Hotspot on continental breakup within the domain. The Central Domain is characterized by two regions of oceanic crust of varying morphology segregated by a high amplitude magnetic anomaly. Geophysical observations suggest that the basement directly inboard of this magnetic anomaly is composed of thin, rugged, and poorly structured, proto-oceanic crust, similar in morphology to oceanic crust formed at ultraslow/slow mid-ocean ridged. Outboard of this anomaly, oceanic crust appears to be well-structured and of normal thickness. We offer three, non-exclusive, explanations for the observed change in ocean crustal structure: (1) melt production was initially low at the time of continental breakup, and the progressive decompression of the mantle led to a gradual increase in melt production and ocean crust thickness, (2) melt production was initially low to due lower extension rates and that melt production increased following a change in spreading rate, (3) a change in spreading ridge geometry led to more effective seafloor spreading rate and concurrent increase in melt production. The Western Domain of the Enderby Basin is characterized by abundant fracture zones and anomalously thin oceanic crust. We believe these features arose as a geometric consequence of the originally oblique orientation of continental rifting relative to the extension direction within the domain. Together these observations suggest that the breakup of East Gondwana was highly variable, with notable along-strike differences in crustal deformation and seafloor spreading processes.
NASA Astrophysics Data System (ADS)
Applegarth, L. J.; James, M. R.; van Wyk de Vries, B.; Pinkerton, H.
2007-12-01
Many of the surface features that develop on `a`a and blocky lava flows relate to internal dynamics during flow emplacement, but it can be difficult to infer the precise relationships between morphology and dynamics from observations of flows either during or after their emplacement. Experiments using PEG have greatly improved our understanding of the behaviour of lavas with relatively thin crusts. Here we describe an alternative approach (similar to that of Lescinsky and Merle (2005), GSA Special Paper 396, p.136) in which the crust plays a significant role in flow development. Our experiments investigated the effect of crustal thickness and slope on the morphological development of channelised distal flows. The materials used were high viscosity (104 Pa s) silicone gel to simulate the still-fluid lava, and a mix of sand and plaster to represent the cohesive brittle crust and the confining levees. Experiments were conducted on an inclined board with a reservoir constructed at one end. Silicone was released from the reservoir through a sliding gate, where it encountered a seed flow consisting of a silicone sheet topped with a crust of known depth and constrained by levees. The models therefore represented the influx of fresh lava into a channel. Sequential digital images taken over the course of each experiment allowed marker points on the flow surface to be tracked, and these data were used to construct surface velocity maps. Several experiments were recorded using stereo imagery, allowing changes in the surface relief to be monitored. The insights from these quantitative techniques, combined with morphological observations, are used to illustrate the effect of the crust on the flow dynamics, and to show the response of the brittle crust to the movement of the viscous flow interior. An overview of the experimental techniques and results will be presented, together with an assessment of how the observed model morphologies can be related to features observed in the field.
Morphologic characterization of specific granules in Greyhound eosinophils.
Iazbik, M C; Couto, C G
2005-06-01
"Vacuolated" eosinophils (ie, eosinophils with empty, nonstaining granules) have been described previously in normal Greyhounds. However, to our knowledge, detailed studies of granules in vacuolated and normal eosinophils in this breed have not been performed. The objective of this prospective study was to characterize some of the morphologic, ultrastructural, and cytochemical staining features of specific (primary) granules in both normal and vacuolated eosinophils in Greyhound blood. Morphologic features of eosinophils in Wright's- and Diff-Quik-stained peripheral blood smears from 49 Greyhounds were compared with 200 blood smears from non-Greyhound dogs. Transmission electron microscopy was done on blood from 3 Greyhounds with vacuolated eosinophils and 3 with normal eosinophil granules. Blood smears from 4 of these dogs also were stained cytochemically with alkaline phosphatase (AP), chloracetate esterase (CAE), and alpha naphthyl butyrate esterase (ANBE). The morphologic features and tinctorial properties of vacuolated and normal eosinophils were compared. Twenty-six Greyhounds (53%) had vacuolated eosinophils and 23 (47%) had normal granulated eosinophils in smears stained with Wright's stain. Only 1% of eosinophils were vacuolated in non-Greyhound dogs. Twenty of the 23 (85%) Greyhounds with normal granulated eosinophils on Wright's-stained smears had vacuolated eosinophils in smears stained with Diff-Quik. Ultrastructurally, no morphologic differences were observed between granules of vacuolated and normal eosinophils. Both vacuolated and normal eosinophils in Greyhounds were positive for AP and negative for CAE and ANBE, as expected for normal dogs. Vacuolated eosinophils in Greyhounds likely reflect, at least in part, differential staining properties of the specific granules with different hematologic stains. Ultrastuctural and cytochemical features of eosinophil granules were similar in normal and vacuolated eosinophils from Greyhounds.
A simple 2D biofilm model yields a variety of morphological features.
Hermanowicz, S W
2001-01-01
A two-dimensional biofilm model was developed based on the concept of cellular automata. Three simple, generic processes were included in the model: cell growth, internal and external mass transport and cell detachment (erosion). The model generated a diverse range of biofilm morphologies (from dense layers to open, mushroom-like forms) similar to those observed in real biofilm systems. Bulk nutrient concentration and external mass transfer resistance had a large influence on the biofilm structure.
NASA Astrophysics Data System (ADS)
White, Robin T.; Wu, Alex; Najm, Marina; Orfino, Francesco P.; Dutta, Monica; Kjeang, Erik
2017-05-01
A four-dimensional visualization approach, featuring three dimensions in space and one dimension in time, is proposed to study local electrode degradation effects during voltage cycling in fuel cells. Non-invasive in situ micro X-ray computed tomography (XCT) with a custom fuel cell fixture is utilized to track the same cathode catalyst layer domain throughout various degradation times from beginning-of-life (BOL) to end-of-life (EOL). With this unique approach, new information regarding damage features and trends are revealed, including crack propagation and catalyst layer thinning being quantified by means of image processing and analysis methods. Degradation heterogeneities as a result of local environmental variations under land and channel are also explored, with a higher structural degradation rate under channels being observed. Density and compositional changes resulting from carbon corrosion and catalyst layer collapse and thinning are observed by changes in relative X-ray attenuation from BOL to EOL, which also indicate possible vulnerable regions where crack initiation and propagation may occur. Electrochemical diagnostics and morphological features observed by micro-XCT are correlated by additionally collecting effective catalyst surface area, double layer capacitance, and polarization curves prior to imaging at various stages of degradation.
NASA Astrophysics Data System (ADS)
Goff, John A.; Gulick, Sean P. S.; Cruz, Ligia Perez; Stewart, Heather A.; Davis, Marcy; Duncan, Dan; Saustrup, Steffen; Sanford, Jason; Fucugauchi, Jaime Urrutia
2016-04-01
A high-resolution, near-surface geophysical survey was conducted in 2013 on the Campeche Bank, a carbonate platform offshore of Yucatán, Mexico, to provide a hazard assessment for future scientific drilling into the Chicxulub impact crater. It also provided an opportunity to obtain detailed information on the seafloor morphology and shallow stratigraphy of this understudied region. The seafloor exhibited two morphologies: (1) small-scale (<2 m) bare-rock karstic features, and (2) thin (<1 m) linear sand accumulations overlying the bedrock. Solution pans, circular to oblong depressions featured flat bottoms and steep sides, were the dominant karstic features; they are known to form subaerially by the pooling of rainwater and dissolution of carbonate. Observed pans were 10-50 cm deep and generally 1-8 m wide, but occasionally reach 15 m, significantly larger than any solution pan observed on land (maximum 6 m). These features likely grew over the course of many 10's of thousands of years in an arid environment while subaerially exposed during lowered sea levels. Surface sands are organized into linear bedforms oriented NE-SW, 10's to 100's meters wide, and kilometers long. These features are identified as sand ribbons (longitudinal bedforms), and contained asymmetric secondary transverse bedforms that indicate NE-directed flow. This orientation is incompatible with the prevalent westward current direction; we hypothesize that these features are storm-generated.
Mishchenko, Michael I; Rosenbush, Vera K; Kiselev, Nikolai N
2006-06-20
The totality of new and previous optical observations of a class of high-albedo solar system objects at small phase angles reveals a unique combination of extremely narrow brightness and polarization features centered at exactly the opposition. The specific morphological parameters of these features provide an almost unequivocal evidence that they are caused by the renowned effect of coherent backscattering.
NASA Astrophysics Data System (ADS)
Zhang, Shijun; Jing, Zhongliang; Li, Jianxun
2005-01-01
The rotation invariant feature of the target is obtained using the multi-direction feature extraction property of the steerable filter. Combining the morphological operation top-hat transform with the self-organizing feature map neural network, the adaptive topological region is selected. Using the erosion operation, the topological region shrinkage is achieved. The steerable filter based morphological self-organizing feature map neural network is applied to automatic target recognition of binary standard patterns and real-world infrared sequence images. Compared with Hamming network and morphological shared-weight networks respectively, the higher recognition correct rate, robust adaptability, quick training, and better generalization of the proposed method are achieved.
Features of abandoned cemetery soils on sandy substrates in Northern Poland
NASA Astrophysics Data System (ADS)
Majgier, L.; Rahmonov, O.; Bednarek, R.
2014-06-01
Morphological and chemical features of cemetery soils (Necrosols and undisturbed cemetery soils) have been studied with Northern Poland as an example. Special attention has been given to the contents of the total phosphorus (as an indicator of the anthropogenic impact); the organic carbon; the total nitrogen; the calcium carbonate; and the changes in the acidity and total Ca, Na, K, Al, Fe, Mg, Zn, Cd, and Pb. The soil profiles have been compared to the control soil (a Brunic Arenosol according to the WRB classification) occurring beyond the cemetery area. The changes in the studied burial soils are mainly manifested in their morphology: the disturbance of the primary genetic horizons and the presence of mixed soil horizons and artifacts (bones, coffin remains, limestone-concrete debris of the cemetery infrastructure). Such changes in the chemical properties as an increase in the contents of the organic carbon and total nitrogen and the soil reaction were observed. Our studies have shown that the highest Ptotal concentration is observed in the A horizons of the anthropogenic burial horizons and undisturbed cemetery soils. The content of phosphorus in the Necrosols is significantly higher than that in the control soil profile, as is observed for the Cgrb layers of burial Necrosols. The morphology and chemistry of the undisturbed cemetery soils are very similar to those of the control profile.
Spectroscopic Profiles of Comets Garradd and McNaught
NASA Astrophysics Data System (ADS)
Harris, Ien; Pierce, Donna M.; Cochran, Anita L.
2017-10-01
We have used the integral-field unit spectrograph (the George and Cynthia Mitchell Spectrograph) on the 2.7m Harlan J. Smith telescope at McDonald Observatory to obtain spectroscopic images of the comae of several comets. The images were obtained for various radical species (C2, C3, CN, NH2). Radial and azimuthal average profiles of the radical species were created to enhance any observed cometary coma morphological features. We compare the observed coma features across the observed species and over the different observation periods in order to constrain possible rotational states of the observed comets, as well as determine possible source differences in the coma between the observed radical species. We will present results for several comets, including C/2009 P1 (Garradd) and 260P (McNaught).
Pattern Recognition Approaches for Breast Cancer DCE-MRI Classification: A Systematic Review.
Fusco, Roberta; Sansone, Mario; Filice, Salvatore; Carone, Guglielmo; Amato, Daniela Maria; Sansone, Carlo; Petrillo, Antonella
2016-01-01
We performed a systematic review of several pattern analysis approaches for classifying breast lesions using dynamic, morphological, and textural features in dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI). Several machine learning approaches, namely artificial neural networks (ANN), support vector machines (SVM), linear discriminant analysis (LDA), tree-based classifiers (TC), and Bayesian classifiers (BC), and features used for classification are described. The findings of a systematic review of 26 studies are presented. The sensitivity and specificity are respectively 91 and 83 % for ANN, 85 and 82 % for SVM, 96 and 85 % for LDA, 92 and 87 % for TC, and 82 and 85 % for BC. The sensitivity and specificity are respectively 82 and 74 % for dynamic features, 93 and 60 % for morphological features, 88 and 81 % for textural features, 95 and 86 % for a combination of dynamic and morphological features, and 88 and 84 % for a combination of dynamic, morphological, and other features. LDA and TC have the best performance. A combination of dynamic and morphological features gives the best performance.
Tongue prints in biometric authentication: A pilot study
Jeddy, Nadeem; Radhika, T; Nithya, S
2017-01-01
Background and Objectives: Biometric authentication is an important process for the identification and verification of individuals for security purposes. There are many biometric systems that are currently in use and also being researched. Tongue print is a new biometric authentication tool that is unique and cannot be easily forged because no two tongue prints are similar. The present study aims to evaluate the common morphological features of the tongue and its variations in males and females. The usefulness of alginate impression and dental cast in obtaining the lingual impression was also evaluated. Materials and Methods: The study sample included twenty participants. The participants were subjected to visual examination following which digital photographs of the dorsal surface of the tongue were taken. Alginate impressions of the tongue were made, and casts were prepared using dental stone. The photographs and the casts were analyzed by two observers separately for the surface morphology including shape, presence or absence of fissures and its pattern of distribution. Three reference points were considered to determine the shape of the tongue. Results: The most common morphological feature on the dorsum of the tongue was the presence of central fissures. Multiple vertical fissures were observed in males whereas single vertical fissure was a common finding in females. The fissures were predominantly shallow in males and deep in females. The tongue was predominantly U shaped in males and females. V-shaped tongue was observed in 25% of females. Conclusion: Tongue prints are useful in biometric authentication. The methodology used in the study is simple, easy and can be adopted by dentists on a regular basis. However, large-scale studies are required to validate the results and also identify other features of the tongue that can be used in forensics and biometric authentication process. PMID:28479712
Tongue prints in biometric authentication: A pilot study.
Jeddy, Nadeem; Radhika, T; Nithya, S
2017-01-01
Biometric authentication is an important process for the identification and verification of individuals for security purposes. There are many biometric systems that are currently in use and also being researched. Tongue print is a new biometric authentication tool that is unique and cannot be easily forged because no two tongue prints are similar. The present study aims to evaluate the common morphological features of the tongue and its variations in males and females. The usefulness of alginate impression and dental cast in obtaining the lingual impression was also evaluated. The study sample included twenty participants. The participants were subjected to visual examination following which digital photographs of the dorsal surface of the tongue were taken. Alginate impressions of the tongue were made, and casts were prepared using dental stone. The photographs and the casts were analyzed by two observers separately for the surface morphology including shape, presence or absence of fissures and its pattern of distribution. Three reference points were considered to determine the shape of the tongue. The most common morphological feature on the dorsum of the tongue was the presence of central fissures. Multiple vertical fissures were observed in males whereas single vertical fissure was a common finding in females. The fissures were predominantly shallow in males and deep in females. The tongue was predominantly U shaped in males and females. V-shaped tongue was observed in 25% of females. Tongue prints are useful in biometric authentication. The methodology used in the study is simple, easy and can be adopted by dentists on a regular basis. However, large-scale studies are required to validate the results and also identify other features of the tongue that can be used in forensics and biometric authentication process.
Analyzing surface features on icy satellites using a new two-layer analogue model
NASA Astrophysics Data System (ADS)
Morales, K. M.; Leonard, E. J.; Pappalardo, R. T.; Yin, A.
2017-12-01
The appearance of similar surface morphologies across many icy satellites suggests potentially unified formation mechanisms. Constraining the processes that shape the surfaces of these icy worlds is fundamental to understanding their rheology and thermal evolution—factors that have implications for potential habitability. Analogue models have proven useful for investigating and quantifying surface structure formation on Earth, but have only been sparsely applied to icy bodies. In this study, we employ an innovative two-layer analogue model that simulates a warm, ductile ice layer overlain by brittle surface ice on satellites such as Europa and Enceladus. The top, brittle layer is composed of fine-grained sand while the ductile, lower viscosity layer is made of putty. These materials were chosen because they scale up reasonably to the conditions on Europa and Enceladus. Using this analogue model, we investigate the role of the ductile layer in forming contractional structures (e.g. folds) that would compensate for the over-abundance of extensional features observed on icy satellites. We do this by simulating different compressional scenarios in the analogue model and analyzing whether the resulting features resemble those on icy bodies. If the resulting structures are similar, then the model can be used to quantify the deformation by calculating strain. These values can then be scaled up to Europa or Enceladus and used to quantity the observed surface morphologies and the amount of extensional strain accommodated by certain features. This presentation will focus on the resulting surface morphologies and the calculated strain values from several analogue experiments. The methods and findings from this work can then be expanded and used to study other icy bodies, such as Triton, Miranda, Ariel, and Pluto.
Predictive Value of Morphological Features in Patients with Autism versus Normal Controls
ERIC Educational Resources Information Center
Ozgen, H.; Hellemann, G. S.; de Jonge, M. V.; Beemer, F. A.; van Engeland, H.
2013-01-01
We investigated the predictive power of morphological features in 224 autistic patients and 224 matched-pairs controls. To assess the relationship between the morphological features and autism, we used the receiver operator curves (ROC). In addition, we used recursive partitioning (RP) to determine a specific pattern of abnormalities that is…
NASA Astrophysics Data System (ADS)
Till, Jessica L.; Guyodo, Yohan; Lagroix, France; Morin, Guillaume; Menguy, Nicolas; Ona-Nguema, Georges
2017-03-01
The oriented chains of nanoscale Fe-oxide particles produced by magnetotactic bacteria are a striking example of biomineralization. Several distinguishing features of magnetite particles that comprise bacterial magnetosomes have been proposed to collectively constitute a biosignature of magnetotactic bacteria (Thomas-Keprta et al., 2001). These features include high crystallinity, chemical purity, a single-domain magnetic structure, well-defined crystal morphology, and arrangement of particles in chain structures. Here, we show that magnetite derived from the inorganic breakdown of nanocrystalline goethite exhibits magnetic properties and morphologies remarkably similar to those of biogenic magnetite from magnetosomes. During heating in reducing conditions, oriented nanogoethite aggregates undergo dehydroxylation and transform into stoichiometric magnetite. We demonstrate that highly crystalline single-domain magnetite with euhedral grain morphologies produced abiogenically from goethite meets several of the biogenicity criteria commonly used for the identification of magnetofossils. Furthermore, the suboxic conditions necessary for magnetofossil preservation in sediments are conducive to the reductive alteration of nanogoethite, as well as the preservation of detrital magnetite originally formed from goethite. The findings of this study have potential implications for the identification of biogenic magnetite, particularly in older sediments where diagenesis commonly disrupts the chain structure of magnetosomes. Our results indicate that isolated magnetofossils cannot be positively distinguished from inorganic magnetite on the basis of their magnetic properties and morphology, and that intact chain structures remain the only reliable distinguishing feature of fossil magnetosomes.
Morphological evaluation of clefts of the lip, palate, or both in dogs.
Peralta, Santiago; Fiani, Nadine; Kan-Rohrer, Kimi H; Verstraete, Frank J M
2017-08-01
OBJECTIVE To systematically characterize the morphology of cleft lip, cleft palate, and cleft lip and palate in dogs. ANIMALS 32 client-owned dogs with clefts of the lip (n = 5), palate (23), or both (4) that had undergone a CT or cone-beam CT scan of the head prior to any surgical procedures involving the oral cavity or face. PROCEDURES Dog signalment and skull type were recorded. The anatomic form of each defect was characterized by use of a widely used human oral-cleft classification system on the basis of CT findings and clinical images. Other defect morphological features, including shape, relative size, facial symmetry, and vomer involvement, were also recorded. RESULTS 9 anatomic forms of cleft were identified. Two anatomic forms were identified in the 23 dogs with cleft palate, in which differences in defect shape and size as well as vomer abnormalities were also evident. Seven anatomic forms were observed in 9 dogs with cleft lip or cleft lip and palate, and most of these dogs had incisive bone abnormalities and facial asymmetry. CONCLUSIONS AND CLINICAL RELEVANCE The morphological features of congenitally acquired cleft lip, cleft palate, and cleft lip and palate were complex and varied among dogs. The features identified here may be useful for surgical planning, developing of clinical coding schemes, or informing genetic, embryological, or clinical research into birth defects in dogs and other species.
Hautier, Lionel; Lebrun, Renaud; Saksiri, Soonchan; Michaux, Jacques; Vianey-Liaud, Monique; Marivaux, Laurent
2011-01-01
While exceptional for an intense diversification of lineages, the evolutionary history of the order Rodentia comprises only a limited number of morphological morphotypes for the mandible. This situation could partly explain the intense debates about the taxonomic position of the latest described member of this clade, the Laotian rock rat Laonastes aenigmamus (Diatomyidae). This discovery has re-launched the debate on the definition of the Hystricognathi suborder identified using the angle of the jaw relative to the plane of the incisors. Our study aims to end this ambiguity. For clarity, it became necessary to revisit the entire morphological diversity of the mandible in extant and extinct rodents. However, current and past rodent diversity brings out the limitations of the qualitative descriptive approach and highlights the need for a quantitative approach. Here, we present the first descriptive comparison of the masticatory apparatus within the Ctenohystrica clade, in combining classic comparative anatomy with morphometrical methods. First, we quantified the shape of the mandible in rodents using 3D landmarks. Then, the analysis of osteological features was compared to myological features in order to understand the biomechanical origin of this morphological diversity. Among the morphological variation observed, the mandible of Laonastes aenigmamus displays an intermediate association of features that could be considered neither as sciurognathous nor as hystricognathous. PMID:21490933
The extinction and dust-to-gas structure of the planetary nebula NGC 7009 observed with MUSE
NASA Astrophysics Data System (ADS)
Walsh, J. R.; Monreal-Ibero, A.; Barlow, M. J.; Ueta, T.; Wesson, R.; Zijlstra, A. A.
2016-04-01
Context. Dust plays a significant role in planetary nebulae. Dust ejected with the gas in the asymptotic giant branch (AGB) phase is subject to the harsh environment of the planetary nebula (PN) while the star is evolving towards a white dwarf. Dust surviving the PN phase contributes to the dust content of the interstellar medium. Aims: The morphology of the internal dust extinction has been mapped for the first time in a PN, the bright nearby Galactic nebula NGC 7009. The morphologies of the gas, dust extinction and dust-to-gas ratio are compared to the structural features of the nebula. Methods: Emission line maps in H Balmer and Paschen lines were formed from analysis of MUSE cubes of NGC 7009 observed during science verification of the instrument. The measured electron temperature and density from the same cube were employed to predict the theoretical H line ratios and derive the extinction distribution across the nebula. After correction for the interstellar extinction to NGC 7009, the internal AV/NH has been mapped for the first time in a PN. Results: The extinction map of NGC 7009 has considerable structure, broadly corresponding to the morphological features of the nebula. The dust-to-gas ratio, AV/NH, increases from 0.7 times the interstellar value to >5 times from the centre towards the periphery of the ionized nebula. The integrated AV/NH is about 2× the mean ISM value. A large-scale feature in the extinction map is a wave, consisting of a crest and trough, at the rim of the inner shell. The nature of this feature is investigated and instrumental and physical causes considered; no convincing mechanisms were identified to produce this feature, other than AGB mass loss variations. Conclusions: Extinction mapping from H emission line imaging of PNe with MUSE provides a powerful tool for revealing the properties of internal dust and the dust-to-gas ratio. Based on observations collected at the European Organisation for Astronomical Research in the Southern Hemisphere under ESO programme 060.A-9347(A).
Klong-Klaew, Tunwadee; Sukontason, Kom; Sribanditmongkol, Pongruk; Moophayak, Kittikhun; Sanit, Sangob; Sukontason, Kabkaew L
2012-11-01
Lucilia porphyrina (Walker) is a blow fly of forensic importance, and shares its geographical distribution with a related forensically important species, Lucilia cuprina (Wiedemann). The immature stages of both species are similar in general appearance; therefore, correct identification should be given special consideration. This study highlighted the main features of L. porphyrina larvae, as observed under light microscopy and scanning electron microscopy. Particular attention is given to the anterior and posterior spiracles, cephalopharyngeal skeleton, and characteristics of the dorsal spines between the prothorax and mesothorax. In the third instar specifically, morphological information on L. porphyrina showed several features that are shared by L. cuprina, and therefore need certain identification to distinguish between them. Such key features are (1) greater posterior spiracle, (2) apparent inner projection between the middle and lower slits of the posterior spiracle, and (3) strongly sclerotized peritreme. The number of papillae on the anterior spiracle may be a supplement, five to nine and three to six in L. porphyrina and L. cuprina, respectively. The key for identifying third instar of forensically important flies in Thailand has been updated to include L. porphyrina.
Homologous prominence non-radial eruptions: A case study
NASA Astrophysics Data System (ADS)
Duchlev, P.; Koleva, K.; Madjarska, M. S.; Dechev, M.
2016-10-01
The present study provides important details on homologous eruptions of a solar prominence that occurred in active region NOAA 10904 on 2006 August 22. We report on the pre-eruptive phase of the homologous feature as well as the kinematics and the morphology of a forth from a series of prominence eruptions that is critical in defining the nature of the previous consecutive eruptions. The evolution of the overlying coronal field during homologous eruptions is discussed and a new observational criterion for homologous eruptions is provided. We find a distinctive sequence of three activation periods each of them containing pre-eruptive precursors such as a brightening and enlarging of the prominence body followed by small surge-like ejections from its southern end observed in the radio 17 GHz. We analyse a fourth eruption that clearly indicates a full reformation of the prominence after the third eruption. The fourth eruption although occurring 11 h later has an identical morphology, the same angle of propagation with respect to the radial direction, as well as similar kinematic evolution as the previous three eruptions. We find an important feature of the homologous eruptive prominence sequence that is the maximum height increase of each consecutive eruption. The present analysis establishes that all four eruptions observed in Hα are of confined type with the third eruption undergoing a thermal disappearance during its eruptive phase. We suggest that the observation of the same direction of the magnetic flux rope (MFR) ejections can be consider as an additional observational criterion for MFR homology. This observational indication for homologous eruptions is important, especially in the case of events of typical or poorly distinguishable morphology of eruptive solar phenomena.
Forming H-shaped and barrel-shaped nebulae with interacting jets
NASA Astrophysics Data System (ADS)
Akashi, Muhammad; Bear, Ealeal; Soker, Noam
2018-04-01
We conduct three-dimensional hydrodynamical simulations of two opposite jets with large opening angles launched from a binary stellar system into a previously ejected shell and show that the interaction can form barrel-like and H-like shapes in the descendant nebula. Such features are observed in planetary nebulae (PNe) and supernova remnants. Under our assumption, the dense shell is formed by a short instability phase of the giant star as it interacts with a stellar companion, and the jets are then launched by the companion as it accretes mass through an accretion disc from the giant star. We find that the H-shaped and barrel-shaped morphological features that the jets form evolve with time, and that there are complicated flow patterns, such as vortices, instabilities, and caps moving ahead along the symmetry axis. We compare our numerical results with images of 12 PNe, and show that jet-shell interaction that we simulate can account for the barrel-like or H-like morphologies that are observed in these PNe.
The Environmental Impact of Intra-Cluster Medium on the Interstellar Medium in Early Type Galaxies
NASA Technical Reports Server (NTRS)
Trinchieri, Ginevra
1993-01-01
Draft versions of three articles submitted for publication are presented. The first two articles address high resolution X-ray images of early type galaxies observed with the ROSAT HRI and PSPC. Data for NGC 1553 and NGC 5846 indicate that the emission is highly irregular, with interesting features at different scales. The gas temperatures also vary both with the galactocentric radius and in correspondence to regions of higher emission and denser material. Strikingly similar features are observed in the X-ray and H-alpha morphologies of NGC 1553 and NGC 5846, while smooth, regular isophotes are observed in NGC 4649 at both wavelengths. The third article addresses ROSAT PSPC observations of 5 X-ray bright early type galaxies.
NASA Astrophysics Data System (ADS)
Startsev, V. V.; Dymov, A. A.; Prokushkin, A. S.
2017-08-01
Morphological features, physicochemical properties, and specific characteristics of the organic matter of cryozems (Cryosols) under postpyrogenic larch forests affected by fires 2, 6, 22, 55, and 116 years ago are considered. The morphological changes in the soils affected by fires are manifested by the burning of the upper organic horizons with preservation of pyrogenic features in the soils for more than a century after the fire. In the first years (2 and 6 years) after the fire, the acidity of the organic horizons and their base saturation become lower. The postpyrogenic soils are characterized by the smaller contribution of the organic horizons to the total pools of soil organic carbon. In the studied cryozems, the organic carbon content is correlated with the contents of oxalate-extractable iron and aluminum. A decrease in the content of water-soluble organic compounds in the soils is observed after the fires; gradually, their content increases upon restoration of the ground cover.
Zonneveld, Rens; Molema, Grietje; Plötz, Frans B
2016-01-01
Alterations in neutrophil morphology (size, shape, and composition), mechanics (deformability), and motility (chemotaxis and migration) have been observed during sepsis. We combine summarizing features of neutrophil morphology, mechanics, and motility that change during sepsis with an investigation into their clinical utility as markers for sepsis through measurement with novel technologies. We performed an initial literature search in MEDLINE using search terms "neutrophil," "morphology," "mechanics," "dynamics," "motility," "mobility," "spreading," "polarization," "migration," and "chemotaxis." We then combined the results with "sepsis" and "septic shock." We scanned bibliographies of included articles to identify additional articles. Final selection was done after the authors reviewed recovered articles. We included articles based on their relevance for our review topic. When compared with resting conditions, sepsis causes an increase in circulating numbers of larger, more rigid neutrophils that show diminished granularity, migration, and chemotaxis. Combined measurement of these variables could provide a more complete view on neutrophil phenotype manifestation. For that purpose, sophisticated automated hematology analyzers, microscopy, and bedside microfluidic devices provide clinically feasible, high-throughput, and cost-limiting means. We propose that integration of features of neutrophil morphology, mechanics, and motility with these new analytical methods can be useful as markers for diagnosis, prognosis, and monitoring of sepsis and may even contribute to basic understanding of its pathophysiology.
Analysis of Europan Cycloid Morphology and Implications for Formation Mechanisms
NASA Technical Reports Server (NTRS)
Marshall, S. T.; Kattenhorn, S. A.
2004-01-01
Europa's highly fractured crust has been shown to contain features with a range of differing morphologies. Most lineaments on Europa are believed to have initiated as cracks, although the type of cracking (e.g. tensile vs. shear) remains unclear and may vary for different morphologies. Arcuate lineaments, called cycloids or flexi, have been observed in nearly all imaged regions of Europa and have been modeled as tensile fractures that were initiated in response to diurnal variations in tides. Despite this hypothesis about the formation mechanism, there have been no detailed analyses of the variable morphologies of cycloids. We have examined Galileo images of numerous locations on Europa to develop a catalog of the different morphologies of cycloids. This study focuses on variations in morphology along individual cycloid segments and differences in cusp styles between segments, while illustrating how morphologic evidence can help unravel formation mechanisms. In so doing, we present evidence for cycloid cusps forming due to secondary fracturing during strike-slip sliding on pre-existing cycloid segments.
Local anaphor licensing in an SOV language: implications for retrieval strategies
Kush, Dave; Phillips, Colin
2014-01-01
Because morphological and syntactic constraints govern the distribution of potential antecedents for local anaphors, local antecedent retrieval might be expected to make equal use of both syntactic and morphological cues. However, previous research (e.g., Dillon et al., 2013) has shown that local antecedent retrieval is not susceptible to the same morphological interference effects observed during the resolution of morphologically-driven grammatical dependencies, such as subject-verb agreement checking (e.g., Pearlmutter et al., 1999). Although this lack of interference has been taken as evidence that syntactic cues are given priority over morphological cues in local antecedent retrieval, the absence of interference could also be the result of a confound in the materials used: the post-verbal position of local anaphors in prior studies may obscure morphological interference that would otherwise be visible if the critical anaphor were in a different position. We investigated the licensing of local anaphors (reciprocals) in Hindi, an SOV language, in order to determine whether pre-verbal anaphors are subject to morphological interference from feature-matching distractors in a way that post-verbal anaphors are not. Computational simulations using a version of the ACT-R parser (Lewis and Vasishth, 2005) predicted that a feature-matching distractor should facilitate the processing of an unlicensed reciprocal if morphological cues are used in antecedent retrieval. In a self-paced reading study we found no evidence that distractors eased processing of an unlicensed reciprocal. However, the presence of a distractor increased difficulty of processing following the reciprocal. We discuss the significance of these results for theories of cue selection in retrieval. PMID:25414680
Antonucci, Francesca; Costa, Corrado; Aguzzi, Jacopo; Cataudella, Stefano
2009-07-01
In many fish species, morphological similarity can be considered as a proxy for similarities in habitat use. The Sparidae family includes species that are recognized for common morphological features such as structure and positioning of the fins and specialized dentition. The aim of this study was to quantitatively describe the relationship of body shape morphology with habitat use, trophic level, and systematics in the majority of known Sparidae species (N = 92). This ecomorphological comparison was performed with a geometric morphometric approach considering as variables the Trophic Index (TROPH), the habitat (i.e., classified as demersal, benthopelagic and reef associated) and the phylogenetic relationship of species at the subfamily level. The analysis by the TROPH variable showed a positive relation with shape because the morphological features of all the species are strongly correlated with their trophic behavior (e.g., herbivore species have a smaller mouth gap that make them able to feed upon sessile resources). The morphological analysis according to the Habitat variable was used to classify species according to a feeding-habitat niche in terms of portion of the water column and seabed space where species mostly perform their behavioral activities. We described three kinds of morphological designs in relation to a benthopelagic, demersal and reef-associated habit. The six subfamily groups were morphologically well distinguishable and the cladogram relative to Mahalanobis' morphological distances was compared with those proposed by other authors. We also quantified the phylogenetic relationship among the different subfamilies based on the analysis of shape in relation to trophic ecology, confirming the observations of the authors. (c) 2009 Wiley-Liss, Inc.
NASA Astrophysics Data System (ADS)
Llave, Estefanía; Jané, Gloria; Maestro, Adolfo; López-Martínez, Jerónimo; Hernández-Molina, F. Javier; Mink, Sandra
2018-07-01
The offshore region of northwestern Iberia offers an opportunity to study the impacts of along-slope processes on the morphology of a glacially influenced continental margin, which has traditionally been conceptually characterised by predominant down-slope sedimentary processes. High-resolution multibeam bathymetry, acoustic backscatter and ultrahigh-resolution seismic reflection profile data are integrated and analysed to describe the present-day and recent geomorphological features and to interpret their associated sedimentary processes. Seventeen large-scale seafloor morphologies and sixteen individual echo types, interpreted as structural features (escarpments, marginal platforms and related fluid escape structures) and depositional and erosional bedforms developed either by the influence of bottom currents (moats, abraded surfaces, sediment waves, contourite drifts and ridges) or by gravitational features (gullies, canyons, slides, channel-levee complexes and submarine fans), are identified for the first time in the study area (spanning 90,000 km2 and water depths of 300 m to 5 km). Different types of slope failures and turbidity currents are mainly observed on the upper and lower slopes and along submarine canyons and deep-sea channels. The middle slope morphologies are mostly determined by the actions of bottom currents (North Atlantic Central Water, Mediterranean Outflow Water, Labrador Sea Water and North Atlantic Deep Water), which thereby define the margin morphologies and favour the reworking and deposition of sediments. The abyssal plains (Biscay and Iberian) are characterised by pelagic deposits and channel-lobe systems (the Cantabrian and Charcot), although several contourite features are also observed at the foot of the slope due to the influence of the deepest water masses (i.e., the North Atlantic Deep Water and Lower Deep Water). This work shows that the study area is the result of Mesozoic to present-day tectonics (e.g. the marginal platforms and structural highs). Therefore, tectonism constitutes a long-term controlling factor, whereas the climate, sediment supply and bottom currents play key roles in the recent short-term architecture and dynamics. Moreover, the recent predominant along-slope sedimentary processes observed in the studied northwestern Iberian Margin represent snapshots of the progressive stages and mixed deep-water system developments of the marginal platforms on passive margins and may provide information for a predictive model of the evolution of other similar margins.
Reñé, Albert; Alacid, Elisabet; Ferrera, Isabel; Garcés, Esther
2017-01-01
Parasites are one of the ecologically most relevant groups of marine food webs, but their taxonomic and biological complexity hampers the assessment of their diversity and evolutionary trends. Moreover, the within-host processes that govern parasitoid infection, development and reproduction are often unknown. In this study, we describe a new species of a perkinsozoan endoparasitoid that infects the toxic dinoflagellate Dinophysis sacculus, by including observations of its morphology, ultrastructure, life-cycle development and phylogeny. The SSU rDNA sequence and main morphological features were also obtained for a second parasitoid species infecting the bloom-forming dinoflagellate Levanderina fissa. Phylogenetic analyses including the sequences obtained show that all known Perkinsozoa species infecting dinoflagellates cluster together. However, sequences of Parvilucifera prorocentri and those obtained in this study cluster at the base of the clade, while the rest of Parvilucifera representatives form a separated highly-supported cluster. These results, together with differing morphological characters like the formation of a germ-tube, the presence of trichocysts, or the heterochromatin presence in zoospores nucleus justify the erection of Dinovorax pyriformis gen. nov. et sp. nov., and Snorkelia prorocentri gen. nov. et comb. nov. (=Parvilucifera prorocentri). The morphological features and phylogenetic position of these parasitoids represent ancestral characters for the Perkinsozoa phylum, and also for Dinozoa clade, allowing the inference of the evolutionary framework of these Alveolata members. PMID:28970818
Structural and ultrastructural features of the agouti tongue (Dasyprocta aguti Linnaeus, 1766)
Ciena, Adriano Polican; Bolina, Cristina de Sousa; de Almeida, Sonia Regina Yokomizo; Rici, Rose Eli Grassi; de Oliveira, Moacir Franco; da da Silva, Marcelo Cavenaghi Pereira; Miglino, Maria Angélica; Watanabe, Ii-sei
2013-01-01
The agouti (Dasyprocta aguti Linnaeus, 1766) is a wild rodent belonging to the family Dasyproctidae that is found throughout Brazil and feeds on fruits and seeds. The aim of the present study was to describe the following features of the tongue of agouti: its morphological structures, the three-dimensional characteristics of the lingual papillae surface, the connective tissue cores (CTCs) and the epithelial cell ultrastructure. Four types of papillae were observed on the dorsal surface of the tongue with a triangular shape: filiform, fungiform, foliate and vallate. Filiform papillae were distributed throughout the tongue surface, and removal of the epithelial surface revealed conical CTCs and multifilaments. Fungiform papillae were observed in the rostral and middle regions, whereas foliate papillae developed in pairs on the lateral margin of the caudal region. Removal of the epithelium in these regions revealed CTCs with parallel laminar conformation. Vallate papillae were arranged in a V-shape in the caudal region, and their CTCs ranged in shape from elongate to ovoid. The ultrastructural components of the dorsal epithelium were the basal, spinous, granular and keratinised layers. A broad area with cytoplasmic projections was identified in the interface region between the lamina propria and the basal layer. Flattened cells with intermediate filaments were observed in the transitional region between spinous and granular layers. The keratinised layer was composed of superimposed epithelial cells where desmosomes and cell-surface microridges were observed. These structural features, including the three-dimensional aspects of the lingual papillae, the CTCs and the epithelial ultrastructure, indicate that when compared with other animals, particularly other rodent species, the morphological features of the tongue of agouti are relatively well developed, especially regarding foliate and vallate papillae. PMID:23701183
Remote Sensing Observations and Numerical Simulation for Martian Layered Ejecta Craters
NASA Astrophysics Data System (ADS)
Li, L.; Yue, Z.; Zhang, C.; Li, D.
2018-04-01
To understand past Martian climates, it is important to know the distribution and nature of water ice on Mars. Impact craters are widely used ubiquitous indicators for the presence of subsurface water or ice on Mars. Remote sensing observations and numerical simulation are powerful tools for investigating morphological and topographic features on planetary surfaces, and we can use the morphology of layered ejecta craters and hydrocode modeling to constrain possible layering and impact environments. The approach of this work consists of three stages. Firstly, the morphological characteristics of the Martian layered ejecta craters are performed based on Martian images and DEM data. Secondly, numerical modeling layered ejecta are performed through the hydrocode iSALE (impact-SALE). We present hydrocode modeling of impacts onto targets with a single icy layer within an otherwise uniform basalt crust to quantify the effects of subsurface H2O on observable layered ejecta morphologies. The model setup is based on a layered target made up of a regolithic layer (described by the basalt ANEOS), on top an ice layer (described by ANEOS equation of H2O ice), in turn on top of an underlying basaltic crust. The bolide is a 0.8 km diameter basaltic asteroid hitting the Martian surface vertically at a velocity of 12.8 km/s. Finally, the numerical results are compared with the MOLA DEM profile in order to analyze the formation mechanism of Martian layered ejecta craters. Our simulations suggest that the presence of an icy layer significantly modifies the cratering mechanics, and many of the unusual features of SLE craters may be explained by the presence of icy layers. Impact cratering on icy satellites is significantly affected by the presence of subsurface H2O.
Nikiyan, Hike; Vasilchenko, Alexey; Deryabin, Dmitry
2010-01-01
The effect of a relative humidity (RH) in a range of 93-65% on morphological and elastic properties of Bacillus cereus and Escherichia coli cells was evaluated using atomic force microscopy. It is shown that gradual dehumidification of bacteria environment has no significant effect on cell dimensional features and considerably decreases them only at 65% RH. The increasing of the bacteria cell wall roughness and elasticity occurs at the same time. Observed changes indicate that morphological properties of B. cereus are rather stable in wide range of relative humidity, whereas E. coli are more sensitive to drying, significantly increasing roughness and stiffness parameters at RH = 84% RH. It is discussed the dependence of the response features on differences in cell wall structure of gram-positive and gram-negative bacterial cells.
NASA Technical Reports Server (NTRS)
Schenk, P. M.
1984-01-01
An evaluation of surface features and structures on the Galilean moon Europa is made using the available high resolution Voyager imagery, low resolution support imaging, and what understanding of ice structure and mechanical behavior science has that is applicable to the problem. A general discussion of the history of Europa studies and the fundamental global morphology is undertaken. The visible lineament and terrain patterns are described, and possible origins discussed. Observations of faulting and block rotation previously described are amplified. A comparison of Europa's structures to terrestrial sea ice and lava lake crust features is also included. Finally, an attempt is made at synthesizing a unified model for the evolution of Europa's crust is presented which is compared with models developed by others.
Earth observations during Space Shuttle flight STS-41 - Discovery's mission to planet earth
NASA Technical Reports Server (NTRS)
Lulla, Kamlesh P.; Helfert, Michael R.; Amsbury, David L.; Whitehead, Victor S.; Richards, Richard N.; Cabana, Robert D.; Shepherd, William M.; Akers, Thomas D.; Melnick, Bruce E.
1991-01-01
An overview of space flight STS-41 is presented, including personal observations and comments by the mission astronauts. The crew deployed the Ulysses spacecraft to study the polar regions of the sun and the interplanetary space above the poles. Environmental observations, including those of Lake Turkana, Lake Chad, biomass burning in Madagascar and Argentina, and circular features in Yucatan are described. Observations that include landforms and geology, continental sedimentation, desert landscapes, and river morphology are discussed.
A new dry hypothesis for the formation of Martian linear gullies
Diniega, Serina; Hansen, Candice J.; McElwaine, Jim N.; Hugenholtz, C.H.; Dundas, Colin M.; McEwen, Alfred S.; Bourke, Mary C.
2013-01-01
Long, narrow grooves found on the slopes of martian sand dunes have been cited as evidence of liquid water via the hypothesis that melt-water initiated debris flows eroded channels and deposited lateral levées. However, this theory has several short-comings for explaining the observed morphology and activity of these linear gullies. We present an alternative hypothesis that is consistent with the observed morphology, location, and current activity: that blocks of CO2 ice break from over-steepened cornices as sublimation processes destabilize the surface in the spring, and these blocks move downslope, carving out levéed grooves of relatively uniform width and forming terminal pits. To test this hypothesis, we describe experiments involving water and CO2 blocks on terrestrial dunes and then compare results with the martian features. Furthermore, we present a theoretical model of the initiation of block motion due to sublimation and use this to quantitatively compare the expected behavior of blocks on the Earth and Mars. The model demonstrates that CO2 blocks can be expected to move via our proposed mechanism on the Earth and Mars, and the experiments show that the motion of these blocks will naturally create the main morphological features of linear gullies seen on Mars.
Styles of crater gradation in Southern Ismenius Lacus, Mars
NASA Technical Reports Server (NTRS)
Grant, J. A.; Schultz, P. H.
1991-01-01
Preserved morphology around selected impact craters together with results from study of long term gradational evolution are used to assess processes responsible for crater modification in southern Ismenius Lacus. Results are compared with the gradational styles of selected terrestrial craters. Although most craters in the region display complex primary morphologies, some first order comparisons with the gradational styles around simple terrestrial craters may be valid. Nearly complete high resolution coverage provides a basis for studying morphologic features at scales comparable to those observed in LANDSAT TM images of terrestrial craters. It is concluded that the relative importance of gradational processes differs around the terrestrial and Martian craters considered here: Martian rimless morphologies are produced by mass wasting, eolian deposition/erosion, and limited fluvial incisement resulting in downwasting and significant backwasting of crater walls.
Silent pituitary macroadenoma co-secreting growth hormone and thyroid stimulating hormone.
Sen, Orhan; Ertorer, M Eda; Aydin, M Volkan; Erdogan, Bulent; Altinors, Nur; Zorludemir, Suzan; Guvener, Nilgun
2005-04-01
Silent pituitary adenomas are a group of tumors showing heterogenous morphological features with no hormonal function observed clinically. To date no explanation has been provided as to why these tumors remain "silent". We report a case of a silent macroadenoma with both growth hormone (GH) and thyroid stimulating hormone (TSH) staining and secretion but with no clinical manifestations, in particular, the absence of features of acromegaly or hyperthyroidism. The relevant literature is reviewed.
Yock, Adam D.; Rao, Arvind; Dong, Lei; Beadle, Beth M.; Garden, Adam S.; Kudchadker, Rajat J.; Court, Laurence E.
2014-01-01
Purpose: To create models that forecast longitudinal trends in changing tumor morphology and to evaluate and compare their predictive potential throughout the course of radiation therapy. Methods: Two morphology feature vectors were used to describe 35 gross tumor volumes (GTVs) throughout the course of intensity-modulated radiation therapy for oropharyngeal tumors. The feature vectors comprised the coordinates of the GTV centroids and a description of GTV shape using either interlandmark distances or a spherical harmonic decomposition of these distances. The change in the morphology feature vector observed at 33 time points throughout the course of treatment was described using static, linear, and mean models. Models were adjusted at 0, 1, 2, 3, or 5 different time points (adjustment points) to improve prediction accuracy. The potential of these models to forecast GTV morphology was evaluated using leave-one-out cross-validation, and the accuracy of the models was compared using Wilcoxon signed-rank tests. Results: Adding a single adjustment point to the static model without any adjustment points decreased the median error in forecasting the position of GTV surface landmarks by the largest amount (1.2 mm). Additional adjustment points further decreased the forecast error by about 0.4 mm each. Selection of the linear model decreased the forecast error for both the distance-based and spherical harmonic morphology descriptors (0.2 mm), while the mean model decreased the forecast error for the distance-based descriptor only (0.2 mm). The magnitude and statistical significance of these improvements decreased with each additional adjustment point, and the effect from model selection was not as large as that from adding the initial points. Conclusions: The authors present models that anticipate longitudinal changes in tumor morphology using various models and model adjustment schemes. The accuracy of these models depended on their form, and the utility of these models includes the characterization of patient-specific response with implications for treatment management and research study design. PMID:25086518
DOE Office of Scientific and Technical Information (OSTI.GOV)
Yock, Adam D.; Kudchadker, Rajat J.; Rao, Arvind
2014-08-15
Purpose: To create models that forecast longitudinal trends in changing tumor morphology and to evaluate and compare their predictive potential throughout the course of radiation therapy. Methods: Two morphology feature vectors were used to describe 35 gross tumor volumes (GTVs) throughout the course of intensity-modulated radiation therapy for oropharyngeal tumors. The feature vectors comprised the coordinates of the GTV centroids and a description of GTV shape using either interlandmark distances or a spherical harmonic decomposition of these distances. The change in the morphology feature vector observed at 33 time points throughout the course of treatment was described using static, linear,more » and mean models. Models were adjusted at 0, 1, 2, 3, or 5 different time points (adjustment points) to improve prediction accuracy. The potential of these models to forecast GTV morphology was evaluated using leave-one-out cross-validation, and the accuracy of the models was compared using Wilcoxon signed-rank tests. Results: Adding a single adjustment point to the static model without any adjustment points decreased the median error in forecasting the position of GTV surface landmarks by the largest amount (1.2 mm). Additional adjustment points further decreased the forecast error by about 0.4 mm each. Selection of the linear model decreased the forecast error for both the distance-based and spherical harmonic morphology descriptors (0.2 mm), while the mean model decreased the forecast error for the distance-based descriptor only (0.2 mm). The magnitude and statistical significance of these improvements decreased with each additional adjustment point, and the effect from model selection was not as large as that from adding the initial points. Conclusions: The authors present models that anticipate longitudinal changes in tumor morphology using various models and model adjustment schemes. The accuracy of these models depended on their form, and the utility of these models includes the characterization of patient-specific response with implications for treatment management and research study design.« less
Mass movement on Vesta at steep scarps and crater rims
NASA Astrophysics Data System (ADS)
Krohn, K.; Jaumann, R.; Otto, K.; Hoogenboom, T.; Wagner, R.; Buczkowski, D. L.; Garry, B.; Williams, D. A.; Yingst, R. A.; Scully, J.; De Sanctis, M. C.; Kneissl, T.; Schmedemann, N.; Kersten, E.; Stephan, K.; Matz, K.-D.; Pieters, C. M.; Preusker, F.; Roatsch, T.; Schenk, P.; Russell, C. T.; Raymond, C. A.
2014-12-01
The Quadrangles Av-11 and Av-12 on Vesta are located at the northern rim of the giant Rheasilvia south polar impact basin. The primary geologic units in Av-11 and Av-12 include material from the Rheasilvia impact basin formation, smooth material and different types of impact crater structures (such as bimodal craters, dark and bright crater ray material and dark ejecta material). Av-11 and Av-12 exhibit almost the full range of mass wasting features observed on Vesta, such as slump blocks, spur-and-gully morphologies and landslides within craters. Processes of collapse, slope instability and seismically triggered events force material to slump down crater walls or scarps and produce landslides or rotational slump blocks. The spur-and-gully morphology that is known to form on Mars is also observed on Vesta; however, on Vesta this morphology formed under dry conditions.
Mass Movement on Vesta at Steep Scarps and Crater Rims
NASA Technical Reports Server (NTRS)
Krohn, K.; Jaumann, R.; Otto, K.; Hoogenboom, T.; Wagner, R.; Buczkowski, D. L.; Garry, B.; Williams, D. A.; Yingst, R. A.; Scully, J.;
2014-01-01
The Quadrangles Av-11 and Av-12 on Vesta are located at the northern rim of the giant Rheasilvia south polar impact basin. The primary geologic units in Av-11 and Av-12 include material from the Rheasilvia impact basin formation, smooth material and different types of impact crater structures (such as bimodal craters, dark and bright crater ray material and dark ejecta material). Av-11 and Av-12 exhibit almost the full range of mass wasting features observed on Vesta, such as slump blocks, spur-and-gully morphologies and landslides within craters. Processes of collapse, slope instability and seismically triggered events force material to slump down crater walls or scarps and produce landslides or rotational slump blocks. The spur-and-gully morphology that is known to form on Mars is also observed on Vesta; however, on Vesta this morphology formed under dry conditions.
Morphology of a Hot Coronal Cavity Core as Observed by Hinode/XRT
NASA Technical Reports Server (NTRS)
Reeves, K. K.; Gibson, S. E.; Kucera, T. A.; Hudson, H. S.
2010-01-01
We follow a coronal cavity that was observed by Hinode/XRT during the summer of 2008. This cavity has a persistent area of relatively bright X-ray emission in its center. We use multifilter data from XRT to study the thermal emission from this cavity, and find that the bright center is hotter than the surrounding cavity plasma with temperatures of about 1.6 MK. We follow the morphology of this hot feature as the cavity structure rotates over the limb during the several days between July 19 - 23 2008. We find that the hot structure at first looks fairly circular, then appears to expand and elongate, and then shrinks again to a compact circular shape. We interpret this apparent change in shape as being due to the morphology of the filament channel associated with the cavity, and the change in viewing angle as the structure rotates over the limb of the Sun.
NASA Astrophysics Data System (ADS)
Mulligan, R. P.; Gomes, E.; McNinch, J.; Brodie, K. L.
2016-02-01
Numerical modelling of the nearshore zone can be computationally intensive due to the complexity of wave breaking, and the need for high temporal and spatial resolution. In this study we apply the SWASH non-hydrostatic wave-flow model that phase-resolves the free surface and fluid motions in the water column at high resolution. The model is forced using observed directional energy spectra, and results are compared to wave observations during moderate storm events. Observations are collected outside the surf zone using acoustic wave and currents sensors, and inside the surf zone over a 100 m transect using high-resolution LIDAR measurements of the sea surface from a sensor mounted on a tower on the beach dune at the Field Research Facility in Duck, NC. The model is applied to four cases with different wave conditions and bathymetry, and used to predict the spatial variability in wave breaking, and correlation between energy dissipation and morphologic features. Model results compare well with observations of spectral evolution outside the surf zone, and with the remotely sensed observations of wave transformation inside the surf zone. The results indicate the importance of nearshore bars, rip-channels, and larger features (major scour depression under the pier following large waves from Hurricane Irene) on the location of wave breaking and alongshore variability in wave energy dissipation.
2013-01-01
Objective The aim of this study was to compare the difference between insulin-producing cells (IPCs) and normal human pancreatic beta cells both in physiological function and morphological features in cellular level. Methods The levels of insulin secretion were measured by enzyme-linked immunosorbent assay. The insulin gene expression was determined by real-time quantitative polymerase chain reaction. The morphological features were detected by atomic force microscopy (AFM) and laser confocal scanning microscopy. Results IPCs and normal human pancreatic beta cells were similar to each other under the observation in AFM with the porous structure features in the cytoplasm. Both number of membrane particle size and average roughness of normal human beta cells were higher than those of IPCs. Conclusions Our results firstly revealed that the cellular ultrastructure of IPCs was closer to that of normal human pancreatic beta cells, but they still could not mimic the physiological regulation of insulin secretion performed by pancreatic beta cells. PMID:23421382
Shen, Simon; Syal, Karan; Tao, Nongjian; Wang, Shaopeng
2015-12-01
We present a Single-Cell Motion Characterization System (SiCMoCS) to automatically extract bacterial cell morphological features from microscope images and use those features to automatically classify cell motion for rod shaped motile bacterial cells. In some imaging based studies, bacteria cells need to be attached to the surface for time-lapse observation of cellular processes such as cell membrane-protein interactions and membrane elasticity. These studies often generate large volumes of images. Extracting accurate bacterial cell morphology features from these images is critical for quantitative assessment. Using SiCMoCS, we demonstrated simultaneous and automated motion tracking and classification of hundreds of individual cells in an image sequence of several hundred frames. This is a significant improvement from traditional manual and semi-automated approaches to segmenting bacterial cells based on empirical thresholds, and a first attempt to automatically classify bacterial motion types for motile rod shaped bacterial cells, which enables rapid and quantitative analysis of various types of bacterial motion.
Growth of ultrananocrystalline diamond film by DC Arcjet plasma enhanced chemical vapor deposition
NASA Astrophysics Data System (ADS)
Chen, G. C.; Li, B.; Yan, Z. Q.; Liu, J.; Lu, F. X.; Ye, H.
2012-06-01
Self-standing diamond films were grown by DC Arcjet plasma enhanced chemical vapor deposition (CVD). The feed gasses were Ar/H2/CH4, in which the flow ratio of CH4 to H2 (F/F) was varied from 5% to 20%. Two distinct morphologies were observed by scanning electron microscope (SEM), i.e. the "pineapple-like" morphology and the "cauliflower-like" morphology. It was found that the morphologies of the as-grown films are strongly dependent on the flow ratio of CH4 to H2 in the feed gasses. High resolution transmission electron microscope (HRTEM) survey results revealed that there were nanocrystalline grains within the "pineapple-like" films whilst there were ultrananocrystalline grains within "cauliflower-like" films. X-ray diffraction (XRD) results suggested that (110) crystalline plane was the dominant surface in the "cauliflower-like" films whilst (100) crystalline plane was the dominant surface in the "pineapple-like" films. Raman spectroscopy revealed that nanostructured carbon features could be observed in both types of films. Plasma diagnosis was carried out in order to understand the morphology dependent growth mechanism. It could be concluded that the film morphology was strongly influenced by the density of gas phases. The gradient of C2 radical was found to be different along the growth direction under the different growth conditions.
Scaling the Morphology of Sapping and Pressurized Groundwater Experiments to Martian Valleys
NASA Astrophysics Data System (ADS)
Marra, W. A.; Kleinhans, M. G.
2013-12-01
Various valleys exist on Mars, which shows the former existence of fluvial activity and thus liquid water at the surface. Although these valleys show similarities with some valleys on Earth, many morphological features are unique for Mars or are very rare on Earth. Therefore, we lack knowledge about the formative processes of these enigmatic valleys. In this study, we explored possible groundwater scenarios for the formation of these valleys using flume experiments, as there are no pure Earth analogues for these systems. We aim to infer their formative processes from morphological properties. A series of flume experiments were carried out in a 4x6x1 m experimental setup, where we observed the valley formation as result from seeping groundwater by both local and distal groundwater sources and by pressurized groundwater release. Time-lapse imagery and DEMs of the experiments show the morphological development, associated processes, and landscape evolution. Indicators of the processes where we particularly looked at were changes in valley slope, cross-sectional shape, the relations between valley dimensions, and regional landscape properties as drainage density and valley size distributions. Hydrological modelling assists in scaling the observed experimental features to real-world systems. Additionally, we looked at valleys on Earth in the Atacama Desert, at Box canyon in Idaho, valleys around Kohala on Hawaii and Apalachicola bluffs in Florida to test the applicability of our methods to real-world systems. In the seeping groundwater valleys, valleys develop due to a combination of mass-wasting failures, mudflows and fluvial flow. The latter two processes are expressed in the final morphology by a break in slope. The mass wasting processes result in U-shaped valleys, which are more pronounced in distal groundwater cases. However, in real-world cases of similar shaped valleys, the cross-sectional shape seems strongly influenced by the strength of the material as well. Groundwater flow piracy of multiple valleys within one system are characterized by equal ratios of width and length development, a property that is absent in case of a local groundwater source which does not induce flow piracy. In case of pressurized groundwater release, the sediment surface in the source area fractured and pits developed due to high groundwater pressure. The resulting valley head consisted of feather-shaped converging flow features. Scaling of the non-fluvial features that relate to groundwater pressure is possible by using hydrological modelling of groundwater pressure and geophysical modelling of the behaviour of the material under such pressures. Our results on sapping valley formation, combined with insights from multiple terrestrial sites of similar valleys contribute to the discussion of some enigmatic valleys on Mars. We provide several quantitative morphological measures, which directly relate to the formative process, which is valuable in linking morphology to the formative process. Our results on pressurized groundwater release prove a long-standing hypothesis on the formation on some of the largest valleys observed in our solar system. In both cases, the insights in the formative processes enable us to quantify the amount of water required for the formation of groundwater-induced Martian valleys.
Deerinck, Thomas J.; Chen, Yibang; He, John C.; Ellisman, Mark H.; Iyengar, Ravi
2017-01-01
Kidney podocytes’ function depends on fingerlike projections (foot processes) that interdigitate with those from neighboring cells to form the glomerular filtration barrier. The integrity of the barrier depends on spatial control of dynamics of actin cytoskeleton in the foot processes. We determined how imbalances in regulation of actin cytoskeletal dynamics could result in pathological morphology. We obtained 3-D electron microscopy images of podocytes and used quantitative features to build dynamical models to investigate how regulation of actin dynamics within foot processes controls local morphology. We find that imbalances in regulation of actin bundling lead to chaotic spatial patterns that could impair the foot process morphology. Simulation results are consistent with experimental observations for cytoskeletal reconfiguration through dysregulated RhoA or Rac1, and they predict compensatory mechanisms for biochemical stability. We conclude that podocyte morphology, optimized for filtration, is intrinsically fragile, whereby local transient biochemical imbalances may lead to permanent morphological changes associated with pathophysiology. PMID:28301477
Modelling morphology evolution during solidification of IPP in processing conditions
DOE Office of Scientific and Technical Information (OSTI.GOV)
Pantani, R., E-mail: rpantani@unisa.it, E-mail: fedesantis@unisa.it, E-mail: vsperanza@unisa.it, E-mail: gtitomanlio@unisa.it; De Santis, F., E-mail: rpantani@unisa.it, E-mail: fedesantis@unisa.it, E-mail: vsperanza@unisa.it, E-mail: gtitomanlio@unisa.it; Speranza, V., E-mail: rpantani@unisa.it, E-mail: fedesantis@unisa.it, E-mail: vsperanza@unisa.it, E-mail: gtitomanlio@unisa.it
During polymer processing, crystallization takes place during or soon after flow. In most of cases, the flow field dramatically influences both the crystallization kinetics and the crystal morphology. On their turn, crystallinity and morphology affect product properties. Consequently, in the last decade, researchers tried to identify the main parameters determining crystallinity and morphology evolution during solidification In processing conditions. In this work, we present an approach to model flow-induced crystallization with the aim of predicting the morphology after processing. The approach is based on: interpretation of the FIC as the effect of molecular stretch on the thermodynamic crystallization temperature; modelingmore » the molecular stretch evolution by means of a model simple and easy to be implemented in polymer processing simulation codes; identification of the effect of flow on nucleation density and spherulites growth rate by means of simple experiments; determination of the condition under which fibers form instead of spherulites. Model predictions reproduce most of the features of final morphology observed in the samples after solidification.« less
M, Bindu; G, Unnikrishnan
2017-09-27
We report the transport characteristics of silicone rubber/nano-hydroxylapatite (SR/n-HA) systems at room temperature with reference to the effects of n-HA loading, morphology and penetrant nature, using toluene, xylene, ethyl acetate and butyl acetate in the liquid phase and methanol, ethanol, 1-propanol, 2-propanol and butanol in the vapour phase as probe molecules. The interaction between the n-HA particles and SR matrix has been confirmed by FTIR analysis. As the n-HA content in the SR matrix increased, the penetrant uptake has been found to decrease. The observations have been correlated with the density and void content of the systems. Scanning electron microscopy images have been found to be complementary to the observed transport features. The reinforcement effect of n-HA particles on the SR matrix has been verified by Kraus equation. Molecular mass between the cross links has been observed to decrease with an increase in n-HA loading. The results have been compared with affine, phantom network, parallel, series and Maxwell models. The transport data have been complemented by observations on biological fluid uptake with urea, d-glucose, KI, saline water, phosphate buffer and artificial urine as the media.
A framework for modeling scenario-based barrier island storm impacts
Mickey, Rangley; Long, Joseph W.; Dalyander, P. Soupy; Plant, Nathaniel G.; Thompson, David M.
2018-01-01
Methods for investigating the vulnerability of existing or proposed coastal features to storm impacts often rely on simplified parametric models or one-dimensional process-based modeling studies that focus on changes to a profile across a dune or barrier island. These simple studies tend to neglect the impacts to curvilinear or alongshore varying island planforms, influence of non-uniform nearshore hydrodynamics and sediment transport, irregular morphology of the offshore bathymetry, and impacts from low magnitude wave events (e.g. cold fronts). Presented here is a framework for simulating regionally specific, low and high magnitude scenario-based storm impacts to assess the alongshore variable vulnerabilities of a coastal feature. Storm scenarios based on historic hydrodynamic conditions were derived and simulated using the process-based morphologic evolution model XBeach. Model results show that the scenarios predicted similar patterns of erosion and overwash when compared to observed qualitative morphologic changes from recent storm events that were not included in the dataset used to build the scenarios. The framework model simulations were capable of predicting specific areas of vulnerability in the existing feature and the results illustrate how this storm vulnerability simulation framework could be used as a tool to help inform the decision-making process for scientists, engineers, and stakeholders involved in coastal zone management or restoration projects.
NASA Astrophysics Data System (ADS)
Dykhuis, Melissa J.; Samarasinha, N. H.; Mueller, B. E. A.; Storm, S. P.
2012-10-01
Observations of temporal variations in the dust and gas morphology of comet nuclei can be used to infer the rotation states of the nuclei. The rotation of component C of Comet 73P/Schwassmann-Wachmann 3 is of particular interest, as it could place constraints on the damping timescale for non-principal axis rotation following the comet's breakup event of 1995 (Crovisier et al. 1995, IAU Circ., 6227). We obtained narrowband H-B and broadband R images of component C from May 3-10, 2006 UT, near the comet's perigee passage, using the 4-meter Mayall telescope on Kitt Peak. We identified the morphological features in the images using the enhancement method of division by azimuthal average. In addition, we binned the data to alleviate issues related to poor guiding and to increase the signal-to-noise. A new method for quantifying measurements of the features allowed for the development of a more robust statistic to evaluate the results, which yielded different period constraints than those found previously in Storm et al. (2007). Analysis of the dust morphology suggests a minimum periodicity of repeatability of the features of about 15 hours. This value is consistent with the lower limit of 10 hours determined from radar data (Nolan et al. 2006, BAAS 38, 504); however, it does not agree with the values around 3-4 hours determined using HST lightcurves and HCN morphology (Toth et al. 2006, BAAS 38, 489; Drahus et al. 2010, A&A 510, respectively). MJD's work was supported by a National Science Foundation Graduate Research Fellowship. NHS and BEAM were supported by the NASA Planetary Atmospheres Program.
Fast Neutron Induced Autophagy Leads To Necrosis In Glioblastoma Multiforme Cells
DOE Office of Scientific and Technical Information (OSTI.GOV)
Yasui, Linda; Gladden, Samantha; Andorf, Christine
Fast neutrons are highly effective at killing glioblastoma multiforme (GBM), U87 and U251 cells. The mode of cell death was investigated using transmission electron microscopy (TEM) to identify the fraction of irradiated U87 or U251 cells having morphological features of autophagy and/or necrosis. U87 or U251 cells were irradiated with 2 Gy fast neturons or 10 Gy {gamma} rays. A majority of U87 and U251 cells exhibit features of cell death with autophagy after irradiation with either 10 Gy {gamma} rays or 2 Gy fast neutrons. Very few {gamma} irradiated cells had features of necrosis (U87 or U251 cell samplesmore » processed for TEM 1 day after 10 Gy {gamma} irradiation). In contrast, a significant increase was observed in necrotic U87 and U251 cells irradiated with fast neutrons. These results show a greater percentage of cells exhibit morphological evidence of necrosis induced by a lower dose of fast neutron irradiation compared to {gamma} irradiation. Also, the evidence of necrosis in fast neutron irradiated U87 and U251 cells occurs in a background of autophagy. Since autophagy is observed before necrosis, autophagy may play a role in signaling programmed necrosis in fast neutron irradiated U87 and U251 cells.« less
Rossi, L F; Luaces, J P; Marcos, H J Aldana; Cetica, P D; Gachen, G; Jimeno, G Pérez; Merani, M S
2011-11-01
The morphological and histological features of the unusual reproductive tract of the female lesser anteater, Tamandua tetradactyla (Myrmecophagidae, Xenarthra), are described for the first time. The present study aimed to establish the main similarities and differences between this species and other xenarthrans. The populations of this species are declining rapidly for a number of reasons and our study is relevant to diverse programs related to its conservation. Studies were carried out on five female genital tracts of adult specimens. Ovaries were ovoid, presenting a medulla completely surrounded by the cortex, differently from that described in other xenarthans. Like in Dasypus but different from all other armadillos studied, single oocyte follicles were observed and a simple the uterus. The uterovaginal canal connects the uterus with the urogenital sinus. The simple columnar epithelium of the uterovaginal canal ends abruptly at a septum which resembles a hymen, where the transitional epithelium of the urogenital sinus appears. This ancestral feature is shared with that of other armadillos, except Tolypeutes matacus, which has a true vagina. Characteristics of the reproductive tract and sperm morphology of other Xenarthra are comparatively discussed. These observations suggest that important reproductive features are shared between the family Myrmecophagidae and the genus Dasypus, a basal group in the phylogeny of Xenarthra. Copyright © 2011 Wiley-Liss, Inc.
Facial movements strategically camouflage involuntary social signals of face morphology.
Gill, Daniel; Garrod, Oliver G B; Jack, Rachael E; Schyns, Philippe G
2014-05-01
Animals use social camouflage as a tool of deceit to increase the likelihood of survival and reproduction. We tested whether humans can also strategically deploy transient facial movements to camouflage the default social traits conveyed by the phenotypic morphology of their faces. We used the responses of 12 observers to create models of the dynamic facial signals of dominance, trustworthiness, and attractiveness. We applied these dynamic models to facial morphologies differing on perceived dominance, trustworthiness, and attractiveness to create a set of dynamic faces; new observers rated each dynamic face according to the three social traits. We found that specific facial movements camouflage the social appearance of a face by modulating the features of phenotypic morphology. A comparison of these facial expressions with those similarly derived for facial emotions showed that social-trait expressions, rather than being simple one-to-one overgeneralizations of emotional expressions, are a distinct set of signals composed of movements from different emotions. Our generative face models represent novel psychophysical laws for social sciences; these laws predict the perception of social traits on the basis of dynamic face identities.
[Morphology of III stage larvae of Angiostrongylus cantonensis in Pomacea canaliculata].
Zhang, Chao-Wei; Zhou, Xiao-Nong; Lv, Shan; Zhang, Yi; Liu, He-Xiang
2008-06-30
To observe the morphologic characteristics of III stage larvae of Angiostrongylus cantonensis from Pomacea canaliculata. P. canaliculata, the intermediate host snail of A. cantonensis, was infected with I stage larvae of A. cantonensis in laboratory. After 61 days, III stage larvae of A. cantonensis were harvested from snail's lungs and muscle of head-foot, followed by HE stain to observe morphological characteristics. The whole body of III stage larva was curling with obtuse head. Its pharyngeal canal extends from the buccal hole on the top of the head to the intestines at the pharyngeal intestine joint place, with apex cauda and clear anal tube. The tegument of the III stage larva was eosin-stained, with a transparent sheath outside of tegument. Some of the larvae cauda showed in circular cylinder, and some larvae presented ventral gland with two very short uterine which used to be the feature only showed in early IV stage larva. Morphologically characteristics of the III stage larvae is helpful to better understand the life-cycle and the control of A. cantonensis.
Nikiyan, Hike; Vasilchenko, Alexey; Deryabin, Dmitry
2010-01-01
The effect of a relative humidity (RH) in a range of 93–65% on morphological and elastic properties of Bacillus cereus and Escherichia coli cells was evaluated using atomic force microscopy. It is shown that gradual dehumidification of bacteria environment has no significant effect on cell dimensional features and considerably decreases them only at 65% RH. The increasing of the bacteria cell wall roughness and elasticity occurs at the same time. Observed changes indicate that morphological properties of B. cereus are rather stable in wide range of relative humidity, whereas E. coli are more sensitive to drying, significantly increasing roughness and stiffness parameters at RH ≤ 84% RH. It is discussed the dependence of the response features on differences in cell wall structure of gram-positive and gram-negative bacterial cells. PMID:20652040
Borucinska, J D; Obasa, O A; Haffey, N M; Scott, J P; Williams, L N; Baker, S M; Min, S J; Kaplan, A; Mudimala, R
2012-10-01
Morphological features of coronary arteries and incidental lesions are reported from hearts in five species of sharks, the shortfin mako shark, Isurus oxyrhinchus Rafinesque, thresher shark Alopias vulpinus (Bonaterre), blue shark, Prionace glauca L., the smooth dogfish, Mustelus canis (Mitchill), and spiny dogfish, Squalus acanthias L. Sharks were collected from the northwestern Atlantic between June and August from 1996 to 2010. They were necropsied dockside and the hearts were preserved in buffered formalin. Routine sections including ventricle/conus arteriosus and the atrio-ventricular junctions were embedded in paraffin, stained with common histological and immunohistochemical methods and examined by brightfield microscopy. Myointimal hyperplasia, medial myo-myxomatous hyperplasia and bifurcation pads were observed commonly, and medial muscle reorientation and epicardial myeloid tissues were rare. All the above features differed in severity, prevalence and distribution depending on anatomical site and shark species/size. Morphometric analysis indicated that myomyxomatous hyperplasia is associated with luminal narrowing of blood vessels. As suggested previously, the described morphological features are most likely physiological responses to blood flow characteristics. Vascular and cardiac lesions were uncommon and included, granulomatous proliferative epicarditis with fibroepitheliomas, myxomatous epicardial expansions, medial arterial vacuolation, myocardial fibrosis, acute ventricular emboli and parasitic granulomas. The lesions of embolism, proliferative and granulomatous epicarditis and myocardial fibrosis were in all sharks associated with capture events including retained fishing hooks. The significance and aetiopathogenesis of medial vacuolation and epicardial myxomatous expansions remains unclear. © 2012 Blackwell Publishing Ltd.
Comprehensive Computational Pathological Image Analysis Predicts Lung Cancer Prognosis.
Luo, Xin; Zang, Xiao; Yang, Lin; Huang, Junzhou; Liang, Faming; Rodriguez-Canales, Jaime; Wistuba, Ignacio I; Gazdar, Adi; Xie, Yang; Xiao, Guanghua
2017-03-01
Pathological examination of histopathological slides is a routine clinical procedure for lung cancer diagnosis and prognosis. Although the classification of lung cancer has been updated to become more specific, only a small subset of the total morphological features are taken into consideration. The vast majority of the detailed morphological features of tumor tissues, particularly tumor cells' surrounding microenvironment, are not fully analyzed. The heterogeneity of tumor cells and close interactions between tumor cells and their microenvironments are closely related to tumor development and progression. The goal of this study is to develop morphological feature-based prediction models for the prognosis of patients with lung cancer. We developed objective and quantitative computational approaches to analyze the morphological features of pathological images for patients with NSCLC. Tissue pathological images were analyzed for 523 patients with adenocarcinoma (ADC) and 511 patients with squamous cell carcinoma (SCC) from The Cancer Genome Atlas lung cancer cohorts. The features extracted from the pathological images were used to develop statistical models that predict patients' survival outcomes in ADC and SCC, respectively. We extracted 943 morphological features from pathological images of hematoxylin and eosin-stained tissue and identified morphological features that are significantly associated with prognosis in ADC and SCC, respectively. Statistical models based on these extracted features stratified NSCLC patients into high-risk and low-risk groups. The models were developed from training sets and validated in independent testing sets: a predicted high-risk group versus a predicted low-risk group (for patients with ADC: hazard ratio = 2.34, 95% confidence interval: 1.12-4.91, p = 0.024; for patients with SCC: hazard ratio = 2.22, 95% confidence interval: 1.15-4.27, p = 0.017) after adjustment for age, sex, smoking status, and pathologic tumor stage. The results suggest that the quantitative morphological features of tumor pathological images predict prognosis in patients with lung cancer. Copyright © 2016 International Association for the Study of Lung Cancer. Published by Elsevier Inc. All rights reserved.
Influence of Stress Corrosion Crack Morphology on Ultrasonic Examination Performances
NASA Astrophysics Data System (ADS)
Dupond, O.; Duwig, V.; Fouquet, T.
2009-03-01
Stress Corrosion Cracking represents a potential damage for several components in PWR. For this reason, NDE of stress corrosion cracks corresponds to an important stake for Electricité de France (EDF) both for availability and for safety of plants. This paper is dedicated to the ultrasonic examination of SCC crack defects. The study mixes an experimental approach conducted on artificial flaws—meant to represent the characteristic morphologic features often encountered on SCC cracks—and a 2D finite element modelling with the code ATHENA 2D developed by EDF. Results indicate that ATHENA reproduces correctly the interaction of the beam on the complex defect. Indeed specific ultrasonic responses resulting from the defect morphology have been observed experimentally and reproduced with the modelling.
Klijn, Marieke E; Hubbuch, Jürgen
2018-04-27
Protein phase diagrams are a tool to investigate cause and consequence of solution conditions on protein phase behavior. The effects are scored according to aggregation morphologies such as crystals or amorphous precipitates. Solution conditions affect morphological features, such as crystal size, as well as kinetic features, such as crystal growth time. Common used data visualization techniques include individual line graphs or symbols-based phase diagrams. These techniques have limitations in terms of handling large datasets, comprehensiveness or completeness. To eliminate these limitations, morphological and kinetic features obtained from crystallization images generated with high throughput microbatch experiments have been visualized with radar charts in combination with the empirical phase diagram (EPD) method. Morphological features (crystal size, shape, and number, as well as precipitate size) and kinetic features (crystal and precipitate onset and growth time) are extracted for 768 solutions with varying chicken egg white lysozyme concentration, salt type, ionic strength and pH. Image-based aggregation morphology and kinetic features were compiled into a single and easily interpretable figure, thereby showing that the EPD method can support high throughput crystallization experiments in its data amount as well as its data complexity. Copyright © 2018. Published by Elsevier Inc.
Investigating Dissolution and Precipitation Phenomena with a Smartphone Microscope
DOE Office of Scientific and Technical Information (OSTI.GOV)
Lumetta, Gregg J.; Arcia, Edgar
A novel smartphone microscope can be used to observe the dissolution and crystallization of sodium chloride at a microscopic level. Observation of these seemingly simple phenomena through the microscope at 100× magnification can actually reveal some surprising behavior. These experiments offer the opportunity to discuss some basic concepts such as how the morphological features of the crystals dictates how the dissolution process proceeds, and how materials can be purified by re-crystallization techniques.
Tan, Bingyao; Wong, Alexander; Bizheva, Kostadinka
2018-01-01
A novel image processing algorithm based on a modified Bayesian residual transform (MBRT) was developed for the enhancement of morphological and vascular features in optical coherence tomography (OCT) and OCT angiography (OCTA) images. The MBRT algorithm decomposes the original OCT image into multiple residual images, where each image presents information at a unique scale. Scale selective residual adaptation is used subsequently to enhance morphological features of interest, such as blood vessels and tissue layers, and to suppress irrelevant image features such as noise and motion artefacts. The performance of the proposed MBRT algorithm was tested on a series of cross-sectional and enface OCT and OCTA images of retina and brain tissue that were acquired in-vivo. Results show that the MBRT reduces speckle noise and motion-related imaging artefacts locally, thus improving significantly the contrast and visibility of morphological features in the OCT and OCTA images. PMID:29760996
The Environmental Impact of Intra-Cluster Medium on the Interstellar Medium in Early Type Galaxies
NASA Technical Reports Server (NTRS)
Trinchieri, Ginevra
1997-01-01
High resolution X-ray images of three early type galaxies observed with the ROSAT HRI are presented. Data for NGC 1553 and NGC 5846 indicate that the emission is highly irregular, with interesting features on scales from a few arcsec to a few arcmin. The gas temperatures also vary both with the galactocentric radius and in correspondence to regions of higher emission and denser material. Strikingly similar features are observed in the X-ray and H(alpha) morphologies of NGC 1553 and NGC 5846, while smoother, more regular isophotes are observed in NGC 4649 at both wavelengths. A connection between these two kinds of emission therefore seems likely. In the light of our observations we discuss possible scenarios that can and account for the connection between X-ray and H(alpha) emissions.
Metric and morphological assessment of facial features: a study on three European populations.
Ritz-Timme, S; Gabriel, P; Tutkuviene, J; Poppa, P; Obertová, Z; Gibelli, D; De Angelis, D; Ratnayake, M; Rizgeliene, R; Barkus, A; Cattaneo, C
2011-04-15
Identification from video surveillance systems is becoming more and more frequent in the forensic practice. In this field, different techniques have been improved such as height estimation and gait analysis. However, the most natural approach for identifying a person in everyday life is based on facial characteristics. Scientifically, faces can be described using morphological and metric assessment of facial features. The morphological approach is largely affected by the subjective opinion of the observer, which can be mitigated by the application of descriptive atlases. In addition, this approach requires one to investigate which are the most common and rare facial characteristics in different populations. For the metric approach further studies are necessary in order to point out possible metric differences within and between different populations. The acquisition of statistically adequate population data may provide useful information for the reconstruction of biological profiles of unidentified individuals, particularly concerning ethnic affiliation, and possibly also for personal identification. This study presents the results of the morphological and metric assessment of the head and face of 900 male subjects between 20 and 31 years from Italy, Germany and Lithuania. The evaluation of the morphological traits was performed using the DMV atlas with 43 pre-defined facial characteristics. The frequencies of the types of facial features were calculated for each population in order to establish the rarest characteristics which may be used for the purpose of a biological profile and consequently for personal identification. Metric analysis performed in vivo included 24 absolute measurements and 24 indices of the head and face, including body height and body weight. The comparison of the frequencies of morphological facial features showed many similarities between the samples from Germany, Italy and Lithuania. However, several characteristics were rare or significantly more or less common in one population compared to the other two. On the other hand, all measurements and indices, except for labial width and intercanthal-mouth index showed significant differences between the three populations. As far as comparisons with other samples are concerned, the three European Caucasian samples differed from North American Caucasian, African and Asian groups as concerns the frequency of the morphological traits and the mean values of the metric analysis. The metric and morphological data collected from three European populations may be useful for forensic purposes in the construction of biological profiles and in screening for personal identification. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.
New Features for Neuron Classification.
Hernández-Pérez, Leonardo A; Delgado-Castillo, Duniel; Martín-Pérez, Rainer; Orozco-Morales, Rubén; Lorenzo-Ginori, Juan V
2018-04-28
This paper addresses the problem of obtaining new neuron features capable of improving results of neuron classification. Most studies on neuron classification using morphological features have been based on Euclidean geometry. Here three one-dimensional (1D) time series are derived from the three-dimensional (3D) structure of neuron instead, and afterwards a spatial time series is finally constructed from which the features are calculated. Digitally reconstructed neurons were separated into control and pathological sets, which are related to three categories of alterations caused by epilepsy, Alzheimer's disease (long and local projections), and ischemia. These neuron sets were then subjected to supervised classification and the results were compared considering three sets of features: morphological, features obtained from the time series and a combination of both. The best results were obtained using features from the time series, which outperformed the classification using only morphological features, showing higher correct classification rates with differences of 5.15, 3.75, 5.33% for epilepsy and Alzheimer's disease (long and local projections) respectively. The morphological features were better for the ischemia set with a difference of 3.05%. Features like variance, Spearman auto-correlation, partial auto-correlation, mutual information, local minima and maxima, all related to the time series, exhibited the best performance. Also we compared different evaluators, among which ReliefF was the best ranked.
Exploring the role of trees in the evolution of meander bends: The Tagliamento River, Italy
NASA Astrophysics Data System (ADS)
Zen, Simone; Gurnell, Angela M.; Zolezzi, Guido; Surian, Nicola
2017-07-01
To date, the role of riparian trees in the formation of scroll bars, ridges, and swales during the evolution of meandering channels has been inferred largely from field observations with support from air photographs. In situ field observations are usually limited to relatively short periods of time, whereas the evolution of these morphological features may take decades. By combining field observations of inner bank morphology and overlying riparian woodland structure with a detailed historical analysis of airborne LiDAR data, panchromatic, and color images, we reconstruct the spatial and temporal evolution of the morphology and vegetation across four meander bends of the Tagliamento River, Italy. Specifically we reveal (i) the appearance of deposited trees and elongated vegetated patches on the inner bank of meander bends following flood events; (ii) temporal progression from deposited trees, through small to larger elongated vegetated patches (pioneer islands), to their coalescence into long, linear vegetated features that eventually become absorbed into the continuous vegetation cover of the riparian forest; and (iii) a spatial correspondence between the resulting scrolls and ridge and swale topography, and tree cover development and persistence. We provide a conceptual model of the mechanisms by which vegetation can contribute to the formation of sequence of ridges and swales on the convex bank of meander bends. We discuss how these insights into the biomorphological processes that control meander bends advance can inform modeling activities that aim to describe the lateral and vertical accretion of the floodplain during the evolution of vegetated river meanders.
Keck Observations of the Gas Dynamics at the Galactic Center
NASA Astrophysics Data System (ADS)
Campbell, Randall; Ciurlo, Anna; Morris, Mark; Sitarski, Breann N.; Ghez, Andrea M.; Do, Tuan
2018-06-01
In the central parsec of the Milky Way Galaxy the environment of the super-massive black hole (SMBH) presents a complicated mixture of stars, gas, and dust. These inner few tens of arcseconds of the GC have been observed at high resolution with Keck for 20 years with the primary goal of monitoring stars orbiting the SMBH. However, the gas features and their dynamics can also be closely examined using this unique baseline of data. In particular, observations with the Keck OSIRIS integral field spectrometer allow us to examine of the dynamical properties of the gas and to possibly identify new “G-type” objects, or dusty stellar objects. We present a study of morphology and orbital dynamics of sub-parsec scale gas features in the central region.
NASA Astrophysics Data System (ADS)
Huh, Hyun; Lee, Jinwoo; Kim, Hyung Jun; Hohng, Sungchul; Kim, Seong Keun
2017-12-01
Application of BALM (binding activated localization microcopy) was shown to allow facile imaging of amyloid fibrils with a typical diameter of ∼14 nm FWHM. We also observed a twisted ribbon-like substructure of mutant amyloid fibrils and even what appear to be toxic amyloid oligomers with their characteristic morphological features consistent with TEM images. Use of an easily available staining dye in this method greatly enhances the prospect of addressing amyloid-related diseases in their diagnosis and drug tests by allowing facile in situ and in vivo detection by optical imaging.
Crack layer morphology and toughness characterization in steels
NASA Technical Reports Server (NTRS)
Chudnovsky, A.; Bessendorf, M.
1983-01-01
Both the macro studies of crack layer propagation are presented. The crack extension resistance parameter R sub 1 based on the morphological study of microdefects is introduced. Experimental study of the history dependent nature of G sub c supports the representation of G sub c as a product of specific enthalpy of damage (material constant) and R sub 1. The latter accounts for the history dependence. The observation of nonmonotonic crack growth under monotonic changes of J as well as statistical features of the critical energy release rate (variance of G sub c) indicate the validity of the proposed damage characterization.
Scaling laws for coastal overwash morphology
NASA Astrophysics Data System (ADS)
Lazarus, Eli D.
2016-12-01
Overwash is a physical process of coastal sediment transport driven by storm events and is essential to landscape resilience in low-lying barrier environments. This work establishes a comprehensive set of scaling laws for overwash morphology: unifying quantitative descriptions with which to compare overwash features by their morphological attributes across case examples. Such scaling laws also help relate overwash features to other morphodynamic phenomena. Here morphometric data from a physical experiment are compared with data from natural examples of overwash features. The resulting scaling relationships indicate scale invariance spanning several orders of magnitude. Furthermore, these new relationships for overwash morphology align with classic scaling laws for fluvial drainages and alluvial fans.
ELLERMAN BOMBS AT HIGH RESOLUTION. I. MORPHOLOGICAL EVIDENCE FOR PHOTOSPHERIC RECONNECTION
DOE Office of Scientific and Technical Information (OSTI.GOV)
Watanabe, Hiroko; Kitai, Reizaburo; Vissers, Gregal
2011-07-20
High-resolution imaging-spectroscopy movies of solar active region NOAA 10998 obtained with the Crisp Imaging Spectropolarimeter at the Swedish 1-m Solar Telescope show very bright, rapidly flickering, flame-like features that appear intermittently in the wings of the Balmer H{alpha} line in a region with moat flows and likely some flux emergence. They show up at regular H{alpha} blue-wing bright points that outline the magnetic network, but flare upward with much larger brightness and distinct 'jet' morphology seen from aside in the limbward view of these movies. We classify these features as Ellerman bombs and present a morphological study of their appearancemore » at the unprecedented spatial, temporal, and spectral resolution of these observations. The bombs appear along the magnetic network with footpoint extents up to 900 km. They show apparent travel away from the spot along the pre-existing network at speeds of about 1 km s{sup -1}. The bombs flare repetitively with much rapid variation at timescales of seconds only, in the form of upward jet-shaped brightness features. These reach heights of 600-1200 km and tend to show blueshifts; some show bi-directional Doppler signature and some seem accompanied with an H{alpha} surge. They are not seen in the core of H{alpha} due to shielding by overlying chromospheric fibrils. The network where they originate has normal properties. The morphology of these jets strongly supports deep-seated photospheric reconnection of emergent or moat-driven magnetic flux with pre-existing strong vertical network fields as the mechanism underlying the Ellerman bomb phenomenon.« less
Pendleton, Elizabeth; Brothers, Laura; Thieler, E. Robert; Sweeney, Edward
2017-01-01
The U.S. Geological Survey and the National Oceanographic and Atmospheric Administration conducted geophysical and hydrographic surveys, respectively, along the inner-continental shelf of Fenwick and Assateague Islands, Maryland and Virginia over the last 40 years. High resolution bathymetry and backscatter data derived from surveys over the last decade are used to describe the morphology and presence of sand ridges on the inner-continental shelf and measure the change in the position of smaller-scale (10–100 s of meters) seafloor features. Bathymetric surveys from the last 30 years link decadal-scale sand ridge migration patterns to the high-resolution measurements of smaller-scale bedform features. Sand ridge morphology on the inner-shelf changes across-shore and alongshore. Areas of similar sand ridge morphology are separated alongshore by zones where ridges are less pronounced or completely transected by transverse dunes. Seafloor-change analyses derived from backscatter data over a 4–7 year period show that southerly dune migration increases in magnitude from north to south, and the east-west pattern of bedform migration changes ~ 10 km north of the Maryland-Virginia state line. Sand ridge morphology and occurrence and bedform migration changes may be connected to observed changes in geologic framework including topographic highs, deflated zones, and sand availability. Additionally, changes in sand ridge occurrence and morphology may help explain changes in the long-term shoreline trends along Fenwick and Assateague Islands. Although the data presented here cannot quantitatively link sand ridges to sediment transport and shoreline change, it does present a compelling relationship between inner-shelf sand availability and movement, sand ridge occurrence and morphology, geologic framework, and shoreline behavior.
NASA Astrophysics Data System (ADS)
Pendleton, Elizabeth A.; Brothers, Laura L.; Thieler, E. Robert; Sweeney, Edward M.
2017-07-01
The U.S. Geological Survey and the National Oceanographic and Atmospheric Administration conducted geophysical and hydrographic surveys, respectively, along the inner-continental shelf of Fenwick and Assateague Islands, Maryland and Virginia over the last 40 years. High resolution bathymetry and backscatter data derived from surveys over the last decade are used to describe the morphology and presence of sand ridges on the inner-continental shelf and measure the change in the position of smaller-scale (10-100 s of meters) seafloor features. Bathymetric surveys from the last 30 years link decadal-scale sand ridge migration patterns to the high-resolution measurements of smaller-scale bedform features. Sand ridge morphology on the inner-shelf changes across-shore and alongshore. Areas of similar sand ridge morphology are separated alongshore by zones where ridges are less pronounced or completely transected by transverse dunes. Seafloor-change analyses derived from backscatter data over a 4-7 year period show that southerly dune migration increases in magnitude from north to south, and the east-west pattern of bedform migration changes 10 km north of the Maryland-Virginia state line. Sand ridge morphology and occurrence and bedform migration changes may be connected to observed changes in geologic framework including topographic highs, deflated zones, and sand availability. Additionally, changes in sand ridge occurrence and morphology may help explain changes in the long-term shoreline trends along Fenwick and Assateague Islands. Although the data presented here cannot quantitatively link sand ridges to sediment transport and shoreline change, it does present a compelling relationship between inner-shelf sand availability and movement, sand ridge occurrence and morphology, geologic framework, and shoreline behavior.
NASA Astrophysics Data System (ADS)
Jha, Rakesh Kumar; Kim, Kanghae; Jeon, Mansik; Kim, Jeehyun; Kang, Minyoung; Han, Insook; Kim, Moonkyu
2016-09-01
Swept-source optical coherence tomography (SS-OCT), a bio-photonic imaging modality, was used to demonstrate an initial feasibility experiment for detecting morphological variations of in-vivo mouse hair follicles for the anagen and the telogen growth stages. Two C57BL/6 adult male mice, one undergoing the anagen stage and the other undergoing the telogen stage of the hair follicle growth cycle, were selected for the experiment. The OCT cross-sectional images of mice skin were acquired in-vivo within an interval of 15 days, and the observed morphological changes were analyzed. The micro-structural features of mice skin on the 15th experimental day were further compared with corresponding histological observations. The preliminary result of this study provides clear insights into the structural details of mouse skin, confirming the resemblance of the OCT images with the corresponding histological measurements, and ensures the suitability of SS-OCT for non-invasive analysis of hair follicle conditions.
Morphology and Admittance Spectroscopy of Cellulose Acetate/Graphene Quantum Dots Nanocomposites
NASA Astrophysics Data System (ADS)
Arthisree, D.; Joshi, Girish M.; Kumar, Annamalai Senthil
Graphene quantum dots (GQDs) are considered as fascinating materials feasible for biological, optoelectronic devices, energy and environmental applications. Casting nanocomposite films for technological application is a challenging research interest. Cellulose acetate (CA) is one of the most abundant, economic, environmental friendly and biodegradable biomaterials. It has been found that CA is a preferred composite matrix to prepare recasting films, due to its efficient antifouling feature. In the present investigation, we exhibited preparation of CA/GQD nanocomposite by solution blending as a function of GQD loading 0.1-0.5wt.%. Morphology and electrical properties were examined as a function of GQD loading. The nanocomposite was characterized by impedance spectroscopy, and the measured admittance (Y) was plotted against temperature across broadband frequency. The magnitude of Y exhibits direct relation under the varying temperature. The morphology of the nanocomposites was observed by atomic force microscope technique in contact mode. Collective observation from our results is that it can be revealed that CA/GQD nanocomposites are suitable for thermal sensing applications.
Pan, Zhengwei; Lerch, Sarah J. L.; Xu, Liang; Li, Xufan; Chuang, Yen-Jun; Howe, Jane Y.; Mahurin, Shannon M.; Dai, Sheng; Hildebrand, Mark
2014-01-01
The morphogenesis of the silica cell walls (called frustules) of unicellular algae known as diatoms is one of the most intriguing mysteries of the diatoms. To study frustule morphogenesis, optical, electron and atomic force microscopy has been extensively used to reveal the frustule morphology. However, since silica frustules are opaque, past observations were limited to outer and fracture surfaces, restricting observations of interior structures. Here we show that opaque silica frustules can be converted into electronically transparent graphene replicas, fabricated using chemical vapor deposition of methane. Chemical vapor deposition creates a continuous graphene coating preserving the frustule's shape and fine, complicated internal features. Subsequent dissolution of the silica with hydrofluoric acid yields a free-standing replica of the internal and external native frustule morphologies. Electron microscopy renders these graphene replicas highly transparent, revealing previously unobserved, complex, three-dimensional, interior frustule structures, which lend new insights into the investigation of frustule morphogenesis. PMID:25135739
Hidden dental diversity in the oldest terrestrial apex predator Dimetrodon.
Brink, Kirstin S; Reisz, Robert R
2014-01-01
Paleozoic sphenacodontid synapsids are the oldest known fully terrestrial apex predators. Dimetrodon and other sphenacodontids are the first terrestrial vertebrates to have strong heterodonty, massive skulls and well-developed labio-lingually compressed and recurved teeth with mesial and distal cutting edges (carinae). Here we reveal that the dentition of Dimetrodon and other sphenacodontids is diverse. Tooth morphology includes simple carinae with smooth cutting edges and elaborate enamel features, including the first occurrence of cusps and true denticles (ziphodonty) in the fossil record. A time-calibrated phylogenetic analysis indicates that changes in dental morphology occur in the absence of any significant changes in skull morphology, suggesting that the morphological change is associated with changes in feeding style and trophic interactions in these ecosystems. In addition, the available evidence indicates that ziphodonty evolved for the first time in the largest known species of the genus Dimetrodon and independently from the ziphodont teeth observed in some therapsids.
Induction of ultra-morphological features of apoptosis in mature and immature sperm.
Grunewald, Sonja; Fitzl, Guenther; Springsguth, Christopher
2017-01-01
There is a fundamental body of evidence suggesting that activated apoptosis signaling in ejaculated human sperm negatively influences their fertilization potential. However, it is still controversial whether this apoptotic signaling is a relic of an abortive apoptosis related to spermatogenesis or if it should be regarded as a functional preformed pathway in mature sperm leading to stereotypical morphological changes reflecting nuclear disassembly. To address this question, apoptosis was induced using betulinic acid in mature and immature ejaculated human sperm enriched by density gradient centrifugation. Execution of apoptosis was monitored by observing ultra-morphological changes via transmission electron microscopy. Typical morphological signs of apoptosis in somatic cells include plasma membrane blebbing with the formation of apoptotic bodies, impaired mitochondrial integrity, defects of the nuclear envelope, and nuclear fragmentation; these morphologies have also been observed in human sperm. In addition, these apoptotic characteristics were more frequent in immature sperm compared to mature sperm. Following betulinic acid treatment, apoptosis-related morphological changes were induced in mature sperm from healthy donors. This effect was much less pronounced in immature sperm. Moreover, in both fractions, the betulinic acid treatment increased the percentage of acrosome-reacted sperm. The results of our ultra-morphological study prove the functional competence of apoptosis in mature ejaculated human sperm. The theory of a sole abortive process may be valid only for immature sperm. The induction of the acrosome reaction by stimulating apoptosis might shed light on the biological relevance of sperm apoptosis.
Ultrastructural hepatocellular features associated with severe hepatic lipidosis in cats.
Center, S A; Guida, L; Zanelli, M J; Dougherty, E; Cummings, J; King, J
1993-05-01
In this study, we compared hepatic ultrastructure in healthy cats, in cats with severe hepatic lipidosis, and in cats with experimentally induced, chronic, extrahepatic bile duct occlusion. Ultrastructural features unique to the lipidosis syndrome included an apparent reduction in number of peroxisomes and alteration in their morphologic features. The quantity of endoplasmic reticulum, Golgi complexes, and lysosomes was subjectively reduced, and paucity of cytosolic glycogen was observed. Bile canaliculi appeared collapsed because of cytosolic distention with lipid. Mitochondria were reduced in number and were markedly pleomorphic. Cristae assumed a variety of shapes, lengths, and orientations. Ultrastructural features of bile duct occlusion were similar to those described in other species and differed from those in cats with hepatic lipidosis.
Materials and Morphology Study for Templated Hydrogen Solidification
Shin, Swanee J.; Kozioziemski, Bernard J.
2017-11-29
In this work, we performed a series of experiments to elucidate the characteristics of a good template for solid hydrogen nucleation. Zinc stands out among several materials with comparable size and shape. Nucleation could be observed to occur on top of sharp features, such as grain boundaries and cracks, but our attempts proved unsuccessful to fabricate or replicate such features. The variations of the supercooling (ΔT) values measured for comparable samples and the dependence of ΔT on the cell temperature cycling revealed that templated nucleation of solid hydrogen is a very delicate process.
Channel Classification across Arid West Landscapes in Support of OHW Delineation
2013-01-01
8 Figure 5. National Hydrography Dataset for Chinle Creek, AZ...the OHW boundary is determined by observing recent physical evidence subsequent to flow. Channel morphology and physical features associated with the...data from the National Hydrography Dataset (NHD) (USGS 2010). The NHD digital ERDC/CRREL TR-13-3 9 stream data were downloaded as a line
NASA Astrophysics Data System (ADS)
Brodie, K. L.; McNinch, J. E.
2008-12-01
Accurate predictions of shoreline response to storms are contingent upon coastal-morphodynamic models effectively synthesizing the complex evolving relationships between beach topography, sandbar morphology, nearshore bathymetry, underlying geology, and the nearshore wave-field during storm events. Analysis of "pre" and "post" storm data sets have led to a common theory for event response of the nearshore system: pre-storm three-dimensional bar and shoreline configurations shift to two-dimensional, linear forms post- storm. A lack of data during storms has unfortunately left a gap in our knowledge of how the system explicitly changes during the storm event. This work presents daily observations of the beach and nearshore during high-energy storm events over a spatially extensive field site (order of magnitude: 10 km) using Bar and Swash Imaging Radar (BASIR), a mobile x-band radar system. The field site contains a complexity of features including shore-oblique bars and troughs, heterogeneous sediment, and an erosional hotspot. BASIR data provide observations of the evolution of shoreline and bar morphology, as well as nearshore bathymetry, throughout the storm events. Nearshore bathymetry is calculated using a bathymetry inversion from radar- derived wave celerity measurements. Preliminary results show a relatively stable but non-linear shore-parallel bar and a non-linear shoreline with megacusp and embayment features (order of magnitude: 1 km) that are enhanced during the wave events. Both the shoreline and shore-parallel bar undulate at a similar spatial frequency to the nearshore shore- oblique bar-field. Large-scale shore-oblique bars and troughs remain relatively static in position and morphology throughout the storm events. The persistence of a three-dimensional shoreline, shore-parallel bar, and large-scale shore-oblique bars and troughs, contradicts the idea of event-driven shifts to two- dimensional morphology and suggests that beach and nearshore response to storms may be location specific. We hypothesize that the influence of underlying geology, defined by (1) the introduction of heterogeneous sediment and (2) the possible creation of shore-oblique bars and troughs in the nearshore, may be responsible for the persistence of three-dimensional forms and the associated shoreline hotspots during storm events.
Klinker, Matthew W.; Marklein, Ross A.; Lo Surdo, Jessica L.; Wei, Cheng-Hong
2017-01-01
Human mesenchymal stromal cell (MSC) lines can vary significantly in their functional characteristics, and the effectiveness of MSC-based therapeutics may be realized by finding predictive features associated with MSC function. To identify features associated with immunosuppressive capacity in MSCs, we developed a robust in vitro assay that uses principal-component analysis to integrate multidimensional flow cytometry data into a single measurement of MSC-mediated inhibition of T-cell activation. We used this assay to correlate single-cell morphological data with overall immunosuppressive capacity in a cohort of MSC lines derived from different donors and manufacturing conditions. MSC morphology after IFN-γ stimulation significantly correlated with immunosuppressive capacity and accurately predicted the immunosuppressive capacity of MSC lines in a validation cohort. IFN-γ enhanced the immunosuppressive capacity of all MSC lines, and morphology predicted the magnitude of IFN-γ–enhanced immunosuppressive activity. Together, these data identify MSC morphology as a predictive feature of MSC immunosuppressive function. PMID:28283659
Brazenor, Alexander K; Saunders, Richard J; Miller, Terrence L; Hutson, Kate S
2018-02-01
Intra-species morphological variation presents a considerable problem for species identification and can result in taxonomic confusion. This is particularly pertinent for species of Neobenedenia which are harmful agents in captive fish populations and have historically been identified almost entirely based on morphological characters. This study aimed to understand how the morphology of Neobenedenia girellae varies with host fish species and the environment. Standard morphological features of genetically indistinct parasites from various host fish species were measured under controlled temperatures and salinities. An initial field-based investigation found that parasite morphology significantly differed between genetically indistinct parasites infecting various host fish species. The majority of the morphological variation observed (60%) was attributed to features that assist in parasite attachment to the host (i.e. the posterior and anterior attachment organs and their accessory hooks) which are important characters in monogenean taxonomy. We then experimentally examined the effects of the interaction between host fish species and environmental factors (temperature and salinity) on the morphology of isogenic parasites derived from a single, isolated hermaphroditic N. girellae infecting barramundi, Lates calcarifer. Experimental infection of L. calcarifer and cobia, Rachycentron canadum, under controlled laboratory conditions did not confer host-mediated phenotypic plasticity in N. girellae, suggesting that measured morphological differences could be adaptive and only occur over multiple parasite generations. Subsequent experimental infection of a single host species, L. calcarifer, at various temperatures (22, 30 and 32 °C) and salinities (35 and 40‰) showed that in the cooler environments (22 °C) N. girellae body proportions were significantly smaller compared with warmer temperatures (30 and 32 °C; P < 0.0001), whereas salinity had no effect. This is evidence that temperature can drive phenotypic plasticity in key taxonomic characters of N. girellae under certain environmental conditions. Copyright © 2017. Published by Elsevier Ltd.
Star formation and ISM morphology in tidally induced spiral structures
NASA Astrophysics Data System (ADS)
Pettitt, Alex R.; Tasker, Elizabeth J.; Wadsley, James W.; Keller, Ben W.; Benincasa, Samantha M.
2017-07-01
Tidal encounters are believed to be one of the key drivers of galactic spiral structure in the Universe. Such spirals are expected to produce different morphological and kinematic features compared to density wave and dynamic spiral arms. In this work, we present high-resolution simulations of a tidal encounter of a small mass companion with a disc galaxy. Included are the effects of gas cooling and heating, star formation and stellar feedback. The structure of the perturbed disc differs greatly from the isolated galaxy, showing clear spiral features that act as sites of new star formation, and displaying interarm spurs. The two arms of the galaxy, the bridge and tail, appear to behave differently; with different star formation histories and structure. Specific attention is focused on offsets between gas and stellar spiral features which can be directly compared to observations. We find that some offsets do exist between different media, with gaseous arms appearing mostly on the convex side of the stellar arms, though the exact locations appear highly time dependent. These results further highlight the differences between tidal spirals and other theories of arm structure.
In-vivo optical investigation of psoriasis
NASA Astrophysics Data System (ADS)
Kapsokalyvas, Dimitrios; Cicchi, Riccardo; Bruscino, Nicola; Alfieri, Domenico; Massi, Daniela; Lotti, Torello; Pavone, Francesco S.
2011-03-01
Psoriasis is an autoimmune disease of the skin characterized by hyperkeratosis, hyperproliferation of the epidermis, inflammatory cell accumulation and increased dilatation of dermal papillary blood vessels. Cases of psoriasis were investigated in vivo with optical means in order to evaluate the potential of in vivo optical biopsy. A Polarization Multispectral Dermoscope was employed for the macroscopic observation. Features such as the 'dotted' blood vessels pattern was observed with high contrast. The average size of dot vessels in Psoriasis was measured to be 974 μm2 which is much higher compared to healthy skin. High resolution image sections of the epidermis and the dermis were produced with a custom made Multiphoton Microscope. Imaging extended from the surface of the lesion down to the papillary dermis, at a depth of 200 μm. In the epidermis, a characteristic morphology of the stratum corneum found only in Psoriasis was revealed. Additionally, the cytoplasmic area of the cells in the stratum spinosum layer was found to be smaller than normal. In the dermis the morphological features were more pronounced, where the elongated dermal papillae dominated the papillary layer. Their length exceeds 100μm, which is a far greater value compared to that of healthy skin. These in vivo observations are consistent with the ex vivo histopathological observations, supporting both the applicability and potentiality of multispectral dermoscopy and multiphoton microscopy in the field of in vivo optical investigation and biopsy of skin.
Galaxy Zoo: quantitative visual morphological classifications for 48 000 galaxies from CANDELS
NASA Astrophysics Data System (ADS)
Simmons, B. D.; Lintott, Chris; Willett, Kyle W.; Masters, Karen L.; Kartaltepe, Jeyhan S.; Häußler, Boris; Kaviraj, Sugata; Krawczyk, Coleman; Kruk, S. J.; McIntosh, Daniel H.; Smethurst, R. J.; Nichol, Robert C.; Scarlata, Claudia; Schawinski, Kevin; Conselice, Christopher J.; Almaini, Omar; Ferguson, Henry C.; Fortson, Lucy; Hartley, William; Kocevski, Dale; Koekemoer, Anton M.; Mortlock, Alice; Newman, Jeffrey A.; Bamford, Steven P.; Grogin, N. A.; Lucas, Ray A.; Hathi, Nimish P.; McGrath, Elizabeth; Peth, Michael; Pforr, Janine; Rizer, Zachary; Wuyts, Stijn; Barro, Guillermo; Bell, Eric F.; Castellano, Marco; Dahlen, Tomas; Dekel, Avishai; Ownsworth, Jamie; Faber, Sandra M.; Finkelstein, Steven L.; Fontana, Adriano; Galametz, Audrey; Grützbauch, Ruth; Koo, David; Lotz, Jennifer; Mobasher, Bahram; Mozena, Mark; Salvato, Mara; Wiklind, Tommy
2017-02-01
We present quantified visual morphologies of approximately 48 000 galaxies observed in three Hubble Space Telescope legacy fields by the Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey (CANDELS) and classified by participants in the Galaxy Zoo project. 90 per cent of galaxies have z ≤ 3 and are observed in rest-frame optical wavelengths by CANDELS. Each galaxy received an average of 40 independent classifications, which we combine into detailed morphological information on galaxy features such as clumpiness, bar instabilities, spiral structure, and merger and tidal signatures. We apply a consensus-based classifier weighting method that preserves classifier independence while effectively down-weighting significantly outlying classifications. After analysing the effect of varying image depth on reported classifications, we also provide depth-corrected classifications which both preserve the information in the deepest observations and also enable the use of classifications at comparable depths across the full survey. Comparing the Galaxy Zoo classifications to previous classifications of the same galaxies shows very good agreement; for some applications, the high number of independent classifications provided by Galaxy Zoo provides an advantage in selecting galaxies with a particular morphological profile, while in others the combination of Galaxy Zoo with other classifications is a more promising approach than using any one method alone. We combine the Galaxy Zoo classifications of `smooth' galaxies with parametric morphologies to select a sample of featureless discs at 1 ≤ z ≤ 3, which may represent a dynamically warmer progenitor population to the settled disc galaxies seen at later epochs.
Naturally occurring variation in tadpole morphology and performance linked to predator regime
Johnson, James B; Saenz, Daniel; Adams, Cory K; Hibbitts, Toby J
2015-01-01
Divergent natural selection drives a considerable amount of the phenotypic and genetic variation observed in natural populations. For example, variation in the predator community can generate conflicting selection on behavioral, life-history, morphological, and performance traits. Differences in predator regime can subsequently increase phenotypic and genetic variations in the population and result in the evolution of reproductive barriers (ecological speciation) or phenotypic plasticity. We evaluated morphology and swimming performance in field collected Bronze Frog larvae (Lithobates clamitans) in ponds dominated by predatory fish and those dominated by invertebrate predators. Based on previous experimental findings, we hypothesized that tadpoles from fish-dominated ponds would have small bodies, long tails, and large tail muscles and that these features would facilitate fast-start speed. We also expected to see increased tail fin depth (i.e., the tail-lure morphology) in tadpoles from invertebrate-dominated ponds. Our results support our expectations with respect to morphology in affecting swimming performance of tadpoles in fish-dominated ponds. Furthermore, it is likely that divergent natural selection is playing a role in the diversification on morphology and locomotor performance in this system. PMID:26357533
NASA Astrophysics Data System (ADS)
Bacon, Neil Julian
2001-12-01
I describe experiments to investigate the properties of microscopic ice particles. The goal of the work was to measure parameters that are important in cloud processes and radiative transfer, using a novel technique that avoids the use of substrates. The experiments were conducted in two separate electrodynamic balance chambers. Single, charged ice particles were formed from frost particles or from droplets frozen either homogeneously or heteroge neously with a bionucleant. The particles were trapped at temperatures between -38°C and -4°C and grown or sublimated according to the temperature gradient in the cham ber. I describe observations of breakup of sublimating frost particles, measurements of light scattering by hexagonal crystals, and observations of the morphology of ice particles grown from frozen water droplets and frost particles. The breaking strength of frost particles was an order of magnitude less than that of bulk ice. Light scattering features not previously observed were analyzed and related to crystal dimension. Initial results from a computer model failed to reproduce these features. The widths of scattering peaks suggest that surface roughness may play a role in determining the angular distribution of scattered light. Ice particle mass evolution was found to be consistent with diffusion- limited growth. Crystals grown slowly from frozen droplets adopted isometric habits, while faster growth resulted in thin side-planes, although there was not an exact correspondence between growth conditions and particle morphology. From the morphological transition, I infer lower limits for the critical supersaturation for layer nucleation on the prism face of 2.4% at -15°C, 4.4% at -20°C, and 3.1% at -25°C. Analytic expressions for the size dependence of facet stability are developed, indicating a strong dependence of stability on both crystal size and surface kinetics, and compared with data. I discuss the role of complex particle morphologies in radiative transfer and highlight the need for further measurements.
Sarkisian, B A; Azarov, P A
2014-01-01
The objective of the present work was to study the morphological features of skin wounds inflicted by joinery hand saws designed for longitudinal, transverse, and mixed sawing. A total of 60 injuries to the thigh skin inflicted by the recurring and reciprocating saw movements were simulated. The hand saws had 5 mm high "sharp" and "blunt"-tipped teeth. The analysis of the morphological features of the wounds revealed differences in their length and depth, shape of edge cuts and defects, and the relief of the walls depending on the sawtooth sharpness and the mode of sawing. It is concluded that morphological features of the wounds may be used to determine the type of the saw, the sharpness of its teeth, the direction and frequency of its movements.
Barlenses and X-shaped features compared: two manifestations of boxy/peanut bulges
NASA Astrophysics Data System (ADS)
Laurikainen, E.; Salo, H.
2017-02-01
Aims: We study the morphological characteristics of boxy/peanut-shaped bulges. In particular, we are interested to determine whether most of the flux associated with bulges in galaxies with masses similar to those of the Milky Way at redshift z 0 might belong to the vertically thick inner part of the bar, in a similar manner as in the Milky Way itself. At high galaxy inclinations, these structures are observed as boxy/peanut/X-shaped features, and when the view is near to face-on, they are observed as barlenses. We also study the possibility that bulges in some fraction of unbarred galaxies might form in a similar manner as the bulges in barred galaxies. Methods: We used the Spitzer Survey of Stellar Structure in Galaxies (S4G) and the Near-IR S0 galaxy Survey (NIRS0S) to compile complete samples of galaxies with barlenses (N = 85) and X-shaped features (N = 88). A sample of unbarred galaxies (N = 41) is also selected. For all 214 galaxies unsharp mask images were created, used to recognize the X-shaped features and to measure their linear sizes. To detect possible boxy isophotes (using the B4-parameter), we also performed an isophotal analysis for the barlens galaxies. We use recently published N-body simulations: the models that exhibit boxy/peanut/X/barlens morphologies are viewed from isotropically chosen directions that cover the full range of galaxy inclinations in the sky. The synthetic images were analyzed in a similar manner as the observations. Results: This is the first time that the observed properties of barlenses and X-shaped features are directly compared across a wide range of galaxy inclinations. A comparison with the simulation models shows that the differences in their apparent sizes, a/rbar ≳ 0.5 for barlenses and a/rbar ≲ 0.5 for X-shapes, can be explained by projection effects. Observations at various inclinations are consistent with intrinsic abl ≈ aX ≈ 0.5rbar: here intrinsic size means the face-on semimajor axis length for bars and barlenses, and the semilength of the X-shape when the bar is viewed exactly edge-on. While X-shapes are quite common at intermediate galaxy inclinations (for I = 40°-60° their frequency is about half that of barlenses), they are seldom observed at smaller inclinations. This is consistent with our simulation models, which have a small compact classical bulge that produces a steep inner rotation slope, whereas bulgeless shallow rotation curve models predict that X-shapes should be visible even in a face-on geometry. The steep rotation curve models are also consistent with the observed trend that B4 is positive at low inclination and with negative values for I ≳ 40°-60°; this implies boxy isophotes. In total, only about one quarter of the barlenses (with I ≤ 60°) show boxy isophotes. Conclusions: Our analyses are consistent with the idea that barlenses and X-shaped features are physically the same phenomenon. However, the observed nearly round face-on barlens morphology is expected only when at least a few percent of the disk mass is located in a central component, within a region much smaller than the size of the barlens itself. Barlenses contribute to secular evolution of galaxies, and might even act as a transition phase between barred and unbarred galaxies. We also discuss that the wide range of stellar population ages obtained for the photometric bulges in the literature are consistent with our interpretation.
NASA Astrophysics Data System (ADS)
Fuchs, Thomas J.; Thompson, David R.; Bue, Brian D.; Castillo-Rogez, Julie; Chien, Steve A.; Gharibian, Dero; Wagstaff, Kiri L.
2015-10-01
Spacecraft autonomy is crucial to increase the science return of optical remote sensing observations at distant primitive bodies. To date, most small bodies exploration has involved short timescale flybys that execute prescripted data collection sequences. Light time delay means that the spacecraft must operate completely autonomously without direct control from the ground, but in most cases the physical properties and morphologies of prospective targets are unknown before the flyby. Surface features of interest are highly localized, and successful observations must account for geometry and illumination constraints. Under these circumstances onboard computer vision can improve science yield by responding immediately to collected imagery. It can reacquire bad data or identify features of opportunity for additional targeted measurements. We present a comprehensive framework for onboard computer vision for flyby missions at small bodies. We introduce novel algorithms for target tracking, target segmentation, surface feature detection, and anomaly detection. The performance and generalization power are evaluated in detail using expert annotations on data sets from previous encounters with primitive bodies.
Farrand, W. H.; Gaddis, L.R.; Keszthelyi, L.
2005-01-01
Domes and cones with summit pits located in Acidalia Planitia and Cydonia Mensae were studied using MOC and THEMIS images and a TES-derived thermal inertia map. North of 40.5??N latitude, the features have a dome-like morphology, and south of that latitude, the morphology is more cone-like. Layering is apparent in the summit craters of fresher looking southern cones, and asymmetric aprons were observed in some instances. Some of the northern domes also display layering in their summit craters, but asymmetric aprons were not observed. The northern domes can also display multiple summit pits or no summit pits at all and can occur in association with higher-albedo "pancake" features. The northern domes are higher in albedo but have apparent thermal inertias that are lower than the surrounding plains. The apparent thermal inertia values of the southern cones range from values comparable to the surrounding plains to slightly lower. From the TES thermal inertia map, we infer that the thermal inertia values of the pitted cones are between those of basaltic fine dust and sand, while those of the surrounding plains are closer to that of basaltic sand. While a unique interpretation of the origin of the pitted cones is not possible with the available data, we do not find compelling evidence to suggest an origin related to either basaltic volcanism or ground-ice. Instead, an origin for these features through some combination of mud volcanism and evaporite deposition around geysers and/or springs is most consistent with the observations. Copyright 2005 by the American Geophysical Union.
Wang, Jing-Mei; Zhou, Qiang; Cai, Hou-Rong; Zhuang, Yi; Zhang, Yi-Fen; Xin, Xiao-Yan; Meng, Fan-Qing; Wang, Ya-Ping
2014-01-01
In addition to the typical size, Cryptococcus neoformans can enlarge its size to form titan cells during infection, and its diameter can reach up to 100 μm. Clinical reports about cryptococcal titan cells are rare. Most studies focus on aspects of animal models of infection with titan cells. Herein, we report the clinical and imaging characteristics and histopathologic features of 3 patients with titan cells and 27 patients with pathogens of typical size, and describe the morphological characteristics of titan cells in details. Histologically, 3 patients with titan cells show necrosis, fibrosis and macrophage accumulation. The titan cells appear in necrotic tissue and between macrophages, and have thick wall with unstained halo around them and diameters range from 20 to 80 μm with characteristic of narrow-necked single budding. There are also organisms with typical size. All 27 patients with normal pathogens show epithelioid granulomatous lesions. There is no significantly difference in clinical and imaging feature between the two groups. Cryptococcus neoformans exhibits a striking morphological change for the formation of titan cells during pulmonary infection, which will result in misdiagnosis and under diagnosis. The histopathological changes may be new manifestation, which need to be further confirmed by the study with animal models of infection and the observation of more clinical cases. Careful observation of the tissue sections is necessary.
Sciallis, Andrew P; Bedroske, Patrick P; Schoolmeester, John K; Sukov, William R; Keeney, Gary L; Hodge, Jennelle C; Bell, Debra A
2014-09-01
The existence of a "high-grade endometrial stromal sarcoma" category of tumors has been a controversial subject owing to, among other things, the difficulty in establishing consistent diagnostic criteria. Currently, the recommended classification for such tumors is undifferentiated uterine/endometrial sarcoma. Interest in this subject has recently increased markedly with the identification of recurrent molecular genetic abnormalities. At Mayo Clinic, a group of neoplasms has been observed that morphologically resemble, either cytologically or architecturally, classic "low-grade" endometrial stromal sarcoma but feature obvious deviations, specifically, 17 tumors with unequivocally high-grade morphology. These high-grade tumors displayed 3 morphologic themes: (1) tumors with a component that is identical to low-grade ESS that transitions abruptly into an obviously higher-grade component; (2) tumors composed exclusively of high-grade cells with uniform nuclear features but with a permeative pattern of infiltration; (3) tumors similar to the second group but with a different, yet characteristic, cytomorphology featuring enlarged round to ovoid cells (larger than those found in low-grade ESS) with smooth nuclear membranes and distinct chromatin clearing but lacking prominent nucleoli. We collected clinicopathologic data, applied immunohistochemical studies, and also tested tumors by fluorescence in situ hybridization for abnormalities in JAZF1, PHF1, YWHAE, and CCND1. Tumors from these 3 groups were found to be immunohistochemically and genetically distinct from one another. Most notable was the fact that category 3 contained all the cases that tested positive for YWHAE rearrangement, did not show any classic translocations for JAZF1, PHF1, or CCND1, often presented at a high stage, and behaved aggressively. This study demonstrates the morphologic, immunophenotypic, and molecular genetic heterogeneity that exists within "undifferentiated endometrial sarcomas" as currently defined and lends credence to the effort of subclassifying some tumors as truly "high-grade endometrial stromal sarcomas." Our study also shows that, in the context of undifferentiated endometrial sarcomas, recognition of cytomorphologic features on routine hematoxylin and eosin-stained sections may be used to select tumors with specific molecular genetic changes-that is, translocations involving YWHAE. Our conclusions will help further efforts towards proper sub-classification of these tumors which will aid in diagnosis and potentially affect clinical management.
Capture Zone Distributions and Island Morphologies in Organic Epitaxy and Graphene Formation
NASA Astrophysics Data System (ADS)
Pimpinelli, Alberto; Einstein, T. L.
2013-03-01
Stating that island nucleation is an essential step in the formation of an epitaxial or supported layer may appear trivially obvious. However, less trivial is the observation that the size of the critical nucleus plays a crucial role in that it determines both the island density (and therefore the size of domains) and the evolution of the island morphology. In this talk we will describe recent developments in the analysis of capture zone distributions (CZD) specifically tailored for application to organic materials. We will also describe specific features of organic and graphene island morphologies, and discuss how they are related to the nucleation process and to the size of the critical nucleus. Work at UMD supported by NSF-MRSEC, Grant DMR 05-20471 and NSF CHE 07-49949
The Shock Dynamics of Heterogeneous YSO Jets: 3D Simulations Meet Multi-epoch Observations
DOE Office of Scientific and Technical Information (OSTI.GOV)
Hansen, E. C.; Frank, A.; Hartigan, P.
High-resolution observations of young stellar object (YSO) jets show them to be composed of many small-scale knots or clumps. In this paper, we report results of 3D numerical simulations designed to study how such clumps interact and create morphologies and kinematic patterns seen in emission line observations. Our simulations focus on clump scale dynamics by imposing velocity differences between spherical, over-dense regions, which then lead to the formation of bow shocks as faster clumps overtake slower material. We show that much of the spatial structure apparent in emission line images of jets arises from the dynamics and interactions of thesemore » bow shocks. Our simulations show a variety of time-dependent features, including bright knots associated with Mach stems where the shocks intersect, a “frothy” emission structure that arises from the presence of the Nonlinear Thin Shell Instability along the surfaces of the bow shocks, and the merging and fragmentation of clumps. Our simulations use a new non-equilibrium cooling method to produce synthetic emission maps in H α and [S ii]. These are directly compared to multi-epoch Hubble Space Telescope observations of Herbig–Haro jets. We find excellent agreement between features seen in the simulations and the observations in terms of both proper motion and morphologies. Thus we conclude that YSO jets may be dominated by heterogeneous structures and that interactions between these structures and the shocks they produce can account for many details of YSO jet evolution.« less
Exposed bright features on the comet 67P/Churyumov-Gerasimenko: distribution and evolution
NASA Astrophysics Data System (ADS)
Deshapriya, J. D. P.; Barucci, M. A.; Fornasier, S.; Hasselmann, P. H.; Feller, C.; Sierks, H.; Lucchetti, A.; Pajola, M.; Oklay, N.; Mottola, S.; Masoumzadeh, N.; Tubiana, C.; Güttler, C.; Barbieri, C.; Lamy, P. L.; Rodrigo, R.; Koschny, D.; Rickman, H.; Bertaux, J.-L.; Bertini, I.; Bodewits, D.; Boudreault, S.; Cremonese, G.; Da Deppo, V.; Davidsson, B. J. R.; Debei, S.; Cecco, M. De; Deller, J.; Fulle, M.; Groussin, O.; Gutierrez, P. J.; Hoang, H. V.; Hviid, S. F.; Ip, W.; Jorda, L.; Keller, H. U.; Knollenberg, J.; Kramm, R.; Kührt, E.; Küppers, M.; Lara, L.; Lazzarin, M.; Lopez Moreno, J. J.; Marzari, F.; Naletto, G.; Preusker, F.; Shi, X.; Thomas, N.; Vincent, J.-B.
2018-05-01
Context. Since its arrival at the comet 67P/Churyumov-Gerasimenko in August 2014, the Rosetta spacecraft followed the comet as it went past the perihelion and beyond until September 2016. During this time there were many scientific instruments operating on board Rosetta to study the comet and its evolution in unprecedented detail. In this context, our study focusses on the distribution and evolution of exposed bright features that have been observed by OSIRIS, which is the scientific imaging instrument aboard Rosetta. Aims: We envisage investigating various morphologies of exposed bright features and the mechanisms that triggered their appearance. Methods: We co-registered multi-filter observations of OSIRIS images that are available in reflectance. The Lommel-Seeliger disk function was used to correct for the illumination conditions and the resulting colour cubes were used to perform spectrophotometric analyses on regions of interest. Results: We present a catalogue of 57 exposed bright features observed on the nucleus of the comet, all of which are attributed to the presence of H2O ice on the comet. Furthermore, we categorise these patches under four different morphologies and present geometric albedos for each category. Conclusions: Although the nucleus of 67P/Churyumov-Gerasimenko appears to be dark in general, there are localised H2O ice sources on the comet. Cometary activity escalates towards the perihelion passage and reveals such volatile ices. We propose that isolated H2O ice patches found in smooth terrains in regions, such as Imhotep, Bes, and Hapi, result from frost as an aftermath of the cessation of the diurnal water cycle on the comet as it recedes from perihelion. Upon the comet's return to perihelion, such patches are revealed when sublimation-driven erosion removes the thin dust layers that got deposited earlier. More powerful activity sources such as cometary outbursts are capable of revealing much fresher, less contaminated H2O ice that is preserved with consolidated cometary material, as observed on exposed patches resting on boulders. This is corroborated by our albedo calculations that attribute higher albedos for bright features with formations related to outbursts.
NASA Astrophysics Data System (ADS)
Ivicheva, S. N.; Lysenkov, A. S.; Ovsyannikov, N. A.; Titov, D. D.; Kargin, Yu F.
2018-04-01
The phase composition and morphological features of sialons were studied under the same conditions of firing (duration, temperature) using different initial components, silicon nitride, aluminum nitride, and a mixture of silicon nitrides and aluminum with the application of nitrides of the corresponding oxide (aluminum or silicon) sol-gel method. The effect of the initial reagents composition on the phase composition of the final product and the morphological features of the sialon powders obtained in a single firing step in a nitrogen atmosphere is shown.
NASA Technical Reports Server (NTRS)
Aveiro, H. C.; Hysell, D. L.; Caton, R. G.; Groves, K. M.; Klenzing, J.; Pfaff, R. F.; Stoneback, R.; Heelis, R. A.
2012-01-01
A three-dimensional numerical simulation of plasma density irregularities in the postsunset equatorial F region ionosphere leading to equatorial spread F (ESF) is described. The simulation evolves under realistic background conditions including bottomside plasma shear flow and vertical current. It also incorporates C/NOFS satellite data which partially specify the forcing. A combination of generalized Rayleigh-Taylor instability (GRT) and collisional shear instability (CSI) produces growing waveforms with key features that agree with C/NOFS satellite and ALTAIR radar observations in the Pacific sector, including features such as gross morphology and rates of development. The transient response of CSI is consistent with the observation of bottomside waves with wavelengths close to 30 km, whereas the steady state behavior of the combined instability can account for the 100+ km wavelength waves that predominate in the F region.
Microscopic and macroscopic spectral peculiarities of cutaneous tumours
NASA Astrophysics Data System (ADS)
Borisova, Ekaterina; Genova, Tsanislava; Troyanova, Petranka; Terziev, Ivan; Zakharov, Valery; Bratchenko, Ivan; Lomova, Maria; Gorin, Dmitry; Avramov, Latchezar
2017-12-01
Autofluorescence spectral and confocal microscopic measurements were made on different cutaneous neoplastic lesions, namely basal cell carcinoma, squamous cell carcinoma, malignant melanoma, and their dysplastic forms - keratoacantoma, dysplastic nevi and benign lesions related - basal cell papiloma, seboreic keratosa and compound nevi using excitation at 405 nm. Spectroscopic investigations were made on in vivo and ex vivo tissue samples, and confocal microscopy investigations were made on ex vivo and eosin-haematoxilin stained thin slices of the tumours detected. Correlation between the spectral data received and the microscopic features observed was found, related to the morphological and biochemical alterations during neoplasia growth. Specific spectral features observed in each type of lesion investigated on micro and macro level would be presented and discussed.
Morphology of Some Small Mars North-Polar Volcanic Edifices from Viking Images and MOLA Topography
NASA Technical Reports Server (NTRS)
Wright, H. M.; Sakimoto, S. E. H.; Garvin, J. B.
2000-01-01
Studied features in the northern near polar regions of Mars have morphologies suggesting volcanic origin. The results of this study suggest that these features may represent martian effusive shield volcanics.
Feature and contrast enhancement of mammographic image based on multiscale analysis and morphology.
Wu, Shibin; Yu, Shaode; Yang, Yuhan; Xie, Yaoqin
2013-01-01
A new algorithm for feature and contrast enhancement of mammographic images is proposed in this paper. The approach bases on multiscale transform and mathematical morphology. First of all, the Laplacian Gaussian pyramid operator is applied to transform the mammography into different scale subband images. In addition, the detail or high frequency subimages are equalized by contrast limited adaptive histogram equalization (CLAHE) and low-pass subimages are processed by mathematical morphology. Finally, the enhanced image of feature and contrast is reconstructed from the Laplacian Gaussian pyramid coefficients modified at one or more levels by contrast limited adaptive histogram equalization and mathematical morphology, respectively. The enhanced image is processed by global nonlinear operator. The experimental results show that the presented algorithm is effective for feature and contrast enhancement of mammogram. The performance evaluation of the proposed algorithm is measured by contrast evaluation criterion for image, signal-noise-ratio (SNR), and contrast improvement index (CII).
Feature and Contrast Enhancement of Mammographic Image Based on Multiscale Analysis and Morphology
Wu, Shibin; Xie, Yaoqin
2013-01-01
A new algorithm for feature and contrast enhancement of mammographic images is proposed in this paper. The approach bases on multiscale transform and mathematical morphology. First of all, the Laplacian Gaussian pyramid operator is applied to transform the mammography into different scale subband images. In addition, the detail or high frequency subimages are equalized by contrast limited adaptive histogram equalization (CLAHE) and low-pass subimages are processed by mathematical morphology. Finally, the enhanced image of feature and contrast is reconstructed from the Laplacian Gaussian pyramid coefficients modified at one or more levels by contrast limited adaptive histogram equalization and mathematical morphology, respectively. The enhanced image is processed by global nonlinear operator. The experimental results show that the presented algorithm is effective for feature and contrast enhancement of mammogram. The performance evaluation of the proposed algorithm is measured by contrast evaluation criterion for image, signal-noise-ratio (SNR), and contrast improvement index (CII). PMID:24416072
Non-Hydrostatic Modelling of Waves and Currents over Subtle Bathymetric Features
NASA Astrophysics Data System (ADS)
Gomes, E.; Mulligan, R. P.; McNinch, J.
2014-12-01
Localized areas with high rates of shoreline erosion on beaches, referred to as erosional hotspots, can occur near clusters of relict shore-oblique sandbars. Wave transformation and wave-driven currents over these morphological features could provide an understanding of the hydrodynamic-morphologic coupling mechanism that connects them to the occurrence of erosional hotspots. To investigate this, we use the non-hydrostatic SWASH model that phase-resolves the free surface and fluid motions throughout the water column, allowing for high resolution of wave propagation and breaking processes. In this study we apply a coupled system of nested models including SWAN over a large domain of the North Carolina shelf with smaller nested SWASH domains in areas of interest to determine the hydrodynamic processes occurring over shore oblique bars. In this presentation we focus on a high resolution grid (10 vertical layers, 10 m horizontal resolution) applied to the Duck region with model validation from acoustic wave and current data, and observations from the Coastal Lidar And Radar Imaging System (CLARIS). By altering the bathymetry input for each model run based on bathymetric surveys and comparing the predicted and observed wave heights and current profiles, the effects of subtle bathymetric perturbations have on wave refraction, wave breaking, surf zone currents and vorticity are investigated. The ability to predict wave breaking and hydrodynamics with a non-hydrostatic model may improve our understanding of surf zone dynamics in relation to morphologic conditions.
Cinosi, Vincenzo; Antonini, Roberto; Crateri, Pasqualina; Arancia, Giuseppe
2011-07-01
The plasma membrane lipid composition in AH-130 hepatoma cells was found to change remarkably after polyenylphosphatidylcholine (PPC) treatment. Plasma membranes from cells grown in rats treated for 7 days i.v. with 20 mg/kg/day PPC, when compared to those of control cells, did not show significantly different amounts of cholesterol or phospholipids relative to protein content, but, surprisingly, the individual phospholipid distribution inside the two membrane leaflets changed dramatically. Phosphatidylcholine (PC), the major phospholipid in the external membrane leaflet, increased ~47% (p<0.001). By contrast, phosphatidylethanolamine (PE), the most important component of the inner leaflet, decreased nearly 37% (p<0.001), while sphingomyelin (SM) also decreased ~17%, (p=0.1). Tumor cells collected from control rats at the same time interval and observed by scanning electron microscopy, exhibited a spherical shape with numerous and randomly distributed long microvilli, the same morphological and ultrastructural features displayed by the implanted cells. Conversely, tumor cells from PPC-treated rats no longer showed the roundish cell profile, and microvilli appeared shortened and enlarged, with the formation of surface blebs. Transmission electron microscopy observations confirmed the morphological and ultrastructural cell changes, mainly seen as loss of microvilli and intense cytoplasmic vacuolization. Taken together, these results indicate that the new phospholipid class distribution in the plasma membrane leaflets, modifying tumor cell viable structures, produced heavy cell damage and in many cases brought about complete cellular disintegration.
Morphologic and genetic identification of Diphyllobothrium nihonkaiense in Korea.
Jeon, Hyeong-Kyu; Kim, Kyu-Heon; Huh, Sun; Chai, Jong-Yil; Min, Duk-Young; Rim, Han-Jong; Eom, Keeseon S
2009-12-01
Diphyllobothrium nihonkaiense was first described by Yamane in 1986 but the taxonomical features have been obscure due to lack of critical morphologic criteria in its larval and adult stages. In Korea, this tapeworm had long been known as Diphyllobothrium latum. In this study, we observed 62 specimens collected from Korean residents and analyzed them by morphological features and nucleotide sequences of mitochondrial cox1 gene as well as the ITS1 region. Adult tapeworms were examined after carmine or trichrome stain. Longitudinal sections of the gravid proglottids showed an obtuse angle of about 150 degree between the cirrus sac and seminal vesicle. This angle is known as a major differential point compared with that of D. latum. Nucleotide sequence differences between D. latum and the specimens from Koreans represented 17.3% in mitochondrial DNA cox1 gene. Sequence divergence of ITS1 among 4 Korean isolates was 0.3% and similarity was 99.7% with D. nihonkaiense and D. klebanovskii. All of the Korean specimens analyzed in this study were identified as being D. nihonkaiense (n = 62). We propose its Korean name as "Dong-hae-gin-chon-chung" which means 'long tapeworm of the East Sea' for this newly analyzed diphyllobothriid tapeworm in Korea.
Numerical modeling of planetary-scale waves on Jupiter
NASA Astrophysics Data System (ADS)
Cosentino, Richard; Morales-Juberias, Raul; Simon, Amy
2014-11-01
The atmosphere of Jupiter has multiple alternating east-wind wind jets with different cloud morphologies some of which can be explained by the presence of atmospheric waves. One jet feature observed by Cassini and HST at 30N, called the Jovian Ribbon for its similarity to Saturn's Ribbon, displays chaotic cloud morphology caused by multiple wave components with dominating planetary scale wave-numbers ranging from 13 to 30. Both the cloud morphology and the dominant wave numbers observed change as a function of time and correlate to changes in the jet's speed. The average speed of the westward jet where this Jovian Ribbon is found is small compared to other notable jets that display wave behavior, namely the high velocity eastward jets at 7N (hot spots) and 7S (chevrons). We present the results of numerical simulations that show how attributes like jet speed, location, vertical shear and other background properties of the atmosphere (e.g. static stability) contribute to the development and evolution of wave structures in jets similar to those observed. Additionally, we explore the effects of local convective events and other atmospheric disturbances such as spots, on the morphology of these jets and waves. This work was supported by NASA PATM grant number NNX14AH47G. Computing resources for this research were provided by NMT and Yellowstone at CISL.
An Admittance Survey of Large Volcanoes on Venus: Implications for Volcano Growth
NASA Technical Reports Server (NTRS)
Brian, A. W.; Smrekar, S. E.; Stofan, E. R.
2004-01-01
Estimates of the thickness of the venusian crust and elastic lithosphere are important in determining the rheological and thermal properties of Venus. These estimates offer insights into what conditions are needed for certain features, such as large volcanoes and coronae, to form. Lithospheric properties for much of the large volcano population on Venus are not well known. Previous studies of elastic thickness (Te) have concentrated on individual or small groups of edifices, or have used volcano models and fixed values of Te to match with observations of volcano morphologies. In addition, previous studies use different methods to estimate lithospheric parameters meaning it is difficult to compare their results. Following recent global studies of the admittance signatures exhibited by the venusian corona population, we performed a similar survey into large volcanoes in an effort to determine the range of lithospheric parameters shown by these features. This survey of the entire large volcano population used the same method throughout so that all estimates could be directly compared. By analysing a large number of edifices and comparing our results to observations of their morphology and models of volcano formation, we can help determine the controlling parameters that govern volcano growth on Venus.
McMenamin, P G; Loeffler, K U
1990-06-01
The subretinal spaces (SRS) in 17 human foetal eyes were investigated by light microscopy and scanning and transmission electron microscopy. A hitherto undocumented group of pleomorphic cells was detected on the apical surface of the retinal pigment epithelium (RPE) and on the undersurface of the neural retina. These cells formed a regularly spaced array in the peripheral SRS, particularly in the most anterior portion nearest the ciliary body anlage. The morphology of the SRS cells ranged from a small round or ovoid form with a few short basal pseudopodia to an extremely flattened dendritic form. Ultrastructural features, such as large melanophagolysosomes, consistent with a phagocytic function, were observed in some cells. These SRS cells bore remarkable resemblance to epiplexus and supraependymal cells, considered to be the resident population of macrophages on the ventricular surfaces of the brain. This morphological parallelism, together with the anatomically homologous location, is strong evidence that SRS cells represent a normal population of macrophages in the developing human eye. No features consistent with an RPE or neuronal origin were observed. The possible role of these cells as transient phagocytes in the SRS with a possible destiny as retinal microglia is discussed.
NASA Technical Reports Server (NTRS)
Nimchinsky, E. A.; Hof, P. R.; Young, W. G.; Morrison, J. H.; Bloom, F. E. (Principal Investigator)
1996-01-01
The primate cingulate gyrus contains multiple cortical areas that can be distinguished by several neurochemical features, including the distribution of neurofilament protein-enriched pyramidal neurons. In addition, connectivity and functional properties indicate that there are multiple motor areas in the cortex lining the cingulate sulcus. These motor areas were targeted for analysis of potential interactions among regional specialization, connectivity, and cellular characteristics such as neurochemical profile and morphology. Specifically, intracortical injections of retrogradely transported dyes and intracellular injection were combined with immunocytochemistry to investigate neurons projecting from the cingulate motor areas to the putative forelimb region of the primary motor cortex, area M1. Two separate groups of neurons projecting to area M1 emanated from the cingulate sulcus, one anterior and one posterior, both of which furnished commissural and ipsilateral connections with area M1. The primary difference between the two populations was laminar origin, with the anterior projection originating largely in deep layers, and the posterior projection taking origin equally in superficial and deep layers. With regard to cellular morphology, the anterior projection exhibited more morphologic diversity than the posterior projection. Commissural projections from both anterior and posterior fields originated largely in layer VI. Neurofilament protein distribution was a reliable tool for localizing the two projections and for discriminating between them. Comparable proportions of the two sets of projection neurons contained neurofilament protein, although the density and distribution of the total population of neurofilament protein-enriched neurons was very different in the two subareas of origin. Within a projection, the participating neurons exhibited a high degree of morphologic heterogeneity, and no correlation was observed between somatodendritic morphology and neurofilament protein content. Thus, although the neurons that provide the anterior and posterior cingulate motor projections to area M1 differ morphologically and in laminar origin, their neurochemical profiles are similar with respect to neurofilament protein. This suggests that neurochemical phenotype may be a more important unifying feature for corticocortical projections than morphology.
Glioma grading using cell nuclei morphologic features in digital pathology images
NASA Astrophysics Data System (ADS)
Reza, Syed M. S.; Iftekharuddin, Khan M.
2016-03-01
This work proposes a computationally efficient cell nuclei morphologic feature analysis technique to characterize the brain gliomas in tissue slide images. In this work, our contributions are two-fold: 1) obtain an optimized cell nuclei segmentation method based on the pros and cons of the existing techniques in literature, 2) extract representative features by k-mean clustering of nuclei morphologic features to include area, perimeter, eccentricity, and major axis length. This clustering based representative feature extraction avoids shortcomings of extensive tile [1] [2] and nuclear score [3] based methods for brain glioma grading in pathology images. Multilayer perceptron (MLP) is used to classify extracted features into two tumor types: glioblastoma multiforme (GBM) and low grade glioma (LGG). Quantitative scores such as precision, recall, and accuracy are obtained using 66 clinical patients' images from The Cancer Genome Atlas (TCGA) [4] dataset. On an average ~94% accuracy from 10 fold crossvalidation confirms the efficacy of the proposed method.
Cortical Structures Associated With Sports Participation in Children: A Population-Based Study.
López-Vicente, Mónica; Tiemeier, Henning; Wildeboer, Andrea; Muetzel, Ryan L; Verhulst, Frank C; Jaddoe, Vincent W V; Sunyer, Jordi; White, Tonya
2017-01-01
We studied cortical morphology in relation to sports participation and type of sport using a large sample of healthy children (n = 911). Sports participation data was collected through a parent-reported questionnaire. Magnetic resonance scans were acquired, and different morphological brain features were quantified. Global volumetric measures were not associated with sports participation. We observed thicker cortex in motor and premotor areas associated with sports participation. In boys, team sports participation, relative to individual sports, was related to thinner cortex in prefrontal brain areas involved in the regulation of behaviors. This study showed a relationship between sports participation and brain maturation.
Liao, Weiqi; Long, Xiaojing; Jiang, Chunxiang; Diao, Yanjun; Liu, Xin; Zheng, Hairong; Zhang, Lijuan
2014-05-01
Differentiating mild cognitive impairment (MCI) and Alzheimer Disease (AD) from healthy aging remains challenging. This study aimed to explore the cerebral structural alterations of subjects with MCI or AD as compared to healthy elderly based on the individual and collective effects of cerebral morphologic indices using univariate and multivariate analyses. T1-weighted images (T1WIs) were retrieved from Alzheimer Disease Neuroimaging Initiative database for 116 subjects who were categorized into groups of healthy aging, MCI, and AD. Analysis of covariance (ANCOVA) and multivariate analysis of covariance (MANCOVA) were performed to explore the intergroup morphologic alterations indexed by surface area, curvature index, cortical thickness, and subjacent white matter volume with age and sex controlled as covariates, in 34 parcellated gyri regions of interest (ROIs) for both cerebral hemispheres based on the T1WI. Statistical parameters were mapped on the anatomic images to facilitate visual inspection. Global rather than region-specific structural alterations were revealed in groups of MCI and AD relative to healthy elderly using MANCOVA. ANCOVA revealed that the cortical thickness decreased more prominently in entorhinal, temporal, and cingulate cortices and was positively correlated with patients' cognitive performance in AD group but not in MCI. The temporal lobe features marked atrophy of white matter during the disease dynamics. Significant intercorrelations were observed among the morphologic indices with univariate analysis for given ROIs. Significant global structural alterations were identified in MCI and AD based on MANCOVA model with improved sensitivity. The intercorrelation among the morphologic indices may dampen the use of individual morphological parameter in featuring cerebral structural alterations. Decrease in cortical thickness is not reflective of the cognitive performance at the early stage of AD. Copyright © 2014 AUR. Published by Elsevier Inc. All rights reserved.
Trigo, Tatiane C; Tirelli, Flávia P; de Freitas, Thales R O; Eizirik, Eduardo
2014-01-01
Increased attention towards the Neotropical cats Leopardus guttulus and L. geoffroyi was prompted after genetic studies identified the occurrence of extensive hybridization between them at their geographic contact zone in southern Brazil. This is a region where two biomes intersect, each of which is associated with one of the hybridizing species (Atlantic Forest with L. guttulus and Pampas with L. geoffroyi). In this study, we conducted in-depth analyses of multiple molecular markers aiming to characterize the magnitude and spatial structure of this hybrid zone. We also performed a morphological assessment of these species, aiming to test their phenotypic differentiation at the contact zone, as well as the correlation between morphological features and the admixture status of the individuals. We found strong evidence for extensive and complex hybridization, with at least 40% of the individuals sampled in Rio Grande do Sul state (southernmost Brazil) identified as hybrids resulting from post-F1 generations. Despite such a high level of hybridization, samples collected in this state still comprised two recognizable clusters (genetically and morphologically). Genetically pure individuals were sampled mainly in regions farther from the contact zone, while hybrids concentrated in a central region (exactly at the interface between the two biomes). The morphological data set also revealed a strong spatial structure, which was correlated with the molecular results but displayed an even more marked separation between the clusters. Hybrids often did not present intermediate body sizes and could not be clearly distinguished morphologically from the parental forms. This observation suggests that some selective pressure may be acting on the hybrids, limiting their dispersal away from the hybrid zone and perhaps favoring genomic combinations that maintain adaptive phenotypic features of one or the other parental species.
Trigo, Tatiane C.; Tirelli, Flávia P.; de Freitas, Thales R. O.; Eizirik, Eduardo
2014-01-01
Increased attention towards the Neotropical cats Leopardus guttulus and L. geoffroyi was prompted after genetic studies identified the occurrence of extensive hybridization between them at their geographic contact zone in southern Brazil. This is a region where two biomes intersect, each of which is associated with one of the hybridizing species (Atlantic Forest with L. guttulus and Pampas with L. geoffroyi). In this study, we conducted in-depth analyses of multiple molecular markers aiming to characterize the magnitude and spatial structure of this hybrid zone. We also performed a morphological assessment of these species, aiming to test their phenotypic differentiation at the contact zone, as well as the correlation between morphological features and the admixture status of the individuals. We found strong evidence for extensive and complex hybridization, with at least 40% of the individuals sampled in Rio Grande do Sul state (southernmost Brazil) identified as hybrids resulting from post-F1 generations. Despite such a high level of hybridization, samples collected in this state still comprised two recognizable clusters (genetically and morphologically). Genetically pure individuals were sampled mainly in regions farther from the contact zone, while hybrids concentrated in a central region (exactly at the interface between the two biomes). The morphological data set also revealed a strong spatial structure, which was correlated with the molecular results but displayed an even more marked separation between the clusters. Hybrids often did not present intermediate body sizes and could not be clearly distinguished morphologically from the parental forms. This observation suggests that some selective pressure may be acting on the hybrids, limiting their dispersal away from the hybrid zone and perhaps favoring genomic combinations that maintain adaptive phenotypic features of one or the other parental species. PMID:25250657
Large Impact Features on Icy Galilean Satellites
NASA Technical Reports Server (NTRS)
Moore, J. M.; Schenk, P. M.; Korycansky, D. G.
2017-01-01
Impact crater morphology can be a very useful tool for probing planetary interiors, but nowhere in the solar system is a greater variety of crater morphologies observed (Fig. 1) than on the large icy Galilean satellites Ganymede and Callisto [e.g., 1- 3]. As on the rocky terrestrial planets, impact crater morphology becomes more complex with increasing size on these satellites. With increasing size, however, these same craters become less like their counterparts on the rocky planets. Several impact landforms and structures (multiring furrows, palimpsests, and central domes, for example), have no obvious analogs on any other planets. Further, several studies [e.g., 4-6] have drawn attention to impact landforms on Europa which are unusual, even by Galilean satellite standards. These radical differences in morphology suggest that impact into icy lithospheres that are mechanically distinct from silicate lithospheres may be responsible. As such, large impact structures may be important probes of the interiors of these bodies over time [e.g., 7]. The first goal of this work is to integrate and correlate the detailed morphologic and morphometric measurements and observations of craters on icy Galilean satellites [e.g., 4, 8-12] with new detailed mapping of these structures from Galileo high-resolution images. As a result, we put forward a revised crater taxonomy for Ganymede and Callisto in order to simplify the nonuniform impact crater nomenclature cluttering the literature. We develop and present an integrated model for the development of these unusual crater morphologies and their implications for the thermal evolution of these bodies.
Growth and characterization of cubic SiC single-crystal films on Si
NASA Technical Reports Server (NTRS)
Powell, J. Anthony; Matus, L. G.; Kuczmarski, Maria A.
1987-01-01
Morphological and electrical characterization results are presented for cubic SiC films grown by chemical vapor deposition on single-crystal Si substrates. The films, up to 40 microns thick, were characterized by optical microscopy, (SEM), (TEM), electron channeling, surface profilometry, and Hall measurements. A variety of morphological features observed on the SiC films are described. Electrical measurements showed a decrease in the electron mobility with increasing electron carrier concentration, similar to that observed in Si. Room-temperature electron mobilities up to 520 sq cm/V-s (at an electron carrier concentration of 5 x 10 to the 16th/cu cm) were measured. Finally, a number of parameters believed to be important in the growth process were investigated, and some discussion is given of their possible effects on the film characteristics.
Growth and characterization of cubic SiC single-crystal films on Si
NASA Astrophysics Data System (ADS)
Powell, J. Anthony; Matus, L. G.; Kuczmarski, Maria A.
1987-06-01
Morphological and electrical characterization results are presented for cubic SiC films grown by chemical vapor deposition on single-crystal Si substrates. The films, up to 40 microns thick, were characterized by optical microscopy, (SEM), (TEM), electron channeling, surface profilometry, and Hall measurements. A variety of morphological features observed on the SiC films are described. Electrical measurements showed a decrease in the electron mobility with increasing electron carrier concentration, similar to that observed in Si. Room-temperature electron mobilities up to 520 sq cm/V-s (at an electron carrier concentration of 5 x 10 to the 16th/cu cm) were measured. Finally, a number of parameters believed to be important in the growth process were investigated, and some discussion is given of their possible effects on the film characteristics.
Cardiac morphology after conditions of microgravity during Cosmos 2044
NASA Technical Reports Server (NTRS)
Goldstein, Margaret A.; Edwards, Robert J.; Schroeter, John P.
1992-01-01
Light- and electron-microscopic studies were performed on cardiac muscle from rats flown on Cosmos 2044 and from four control groups. Average cross-sectional area of myofibers was measured by video analysis of the light-microscopic images of papillary and ventricular muscle samples from all animals. This cross-sectional area was significantly decreased in flight rats (P = 0.03) compared with synchronous controls. Additional findings at the electron microscopic level consistent with this atrophy were obtained by stereological analysis and optical diffraction analysis of papillary muscle samples. Slightly higher mitochondrial volume density values and mitochondria-to-myofibril ratios as well as normal A-band spacings (d1,0) and Z-band spacings of myofibrils were observed in the tail-suspension and flight groups. General morphological features similar to those in ventricular samples from the previous Cosmos 1887 flight were observed.
NASA Astrophysics Data System (ADS)
Rae, A. S. P.; Collins, G. S.; Grieve, R. A. F.; Osinski, G. R.; Morgan, J. V.
2017-07-01
Large impact structures have complex morphologies, with zones of structural uplift that can be expressed topographically as central peaks and/or peak rings internal to the crater rim. The formation of these structures requires transient strength reduction in the target material and one of the proposed mechanisms to explain this behavior is acoustic fluidization. Here, samples of shock-metamorphosed quartz-bearing lithologies at the West Clearwater Lake impact structure, Canada, are used to estimate the maximum recorded shock pressures in three dimensions across the crater. These measurements demonstrate that the currently observed distribution of shock metamorphism is strongly controlled by the formation of the structural uplift. The distribution of peak shock pressures, together with apparent crater morphology and geological observations, is compared with numerical impact simulations to constrain parameters used in the block-model implementation of acoustic fluidization. The numerical simulations produce craters that are consistent with morphological and geological observations. The results show that the regeneration of acoustic energy must be an important feature of acoustic fluidization in crater collapse, and should be included in future implementations. Based on the comparison between observational data and impact simulations, we conclude that the West Clearwater Lake structure had an original rim (final crater) diameter of 35-40 km and has since experienced up to 2 km of differential erosion.
Uranus' Persistent Patterns and Features from High-SNR Imaging in 2012-2014
NASA Astrophysics Data System (ADS)
Fry, Patrick M.; Sromovsky, Lawrence A.; de Pater, Imke; Hammel, Heidi B.; Marcus, Phillip
2015-11-01
Since 2012, Uranus has been the subject of an observing campaign utilizing high signal-to-noise imaging techniques at Keck Observatory (Fry et al. 2012, Astron. J. 143, 150-161). High quality observing conditions on four observing runs of consecutive nights allowed longitudinally-complete coverage of the atmosphere over a period of two years (Sromovsky et al. 2015, Icarus 258, 192-223). Global mosaic maps made from images acquired on successive nights in August 2012, November 2012, August 2013, and August 2014, show persistent patterns, and six easily distinguished long-lived cloud features, which we were able to track for long periods that ranged from 5 months to over two years. Two at similar latitudes are associated with dark spots, and move with the atmospheric zonal flow close to the location of their associated dark spot instead of following the flow at the latitude of the bright features. These features retained their morphologies and drift rates in spite of several close interactions. A second pair of features at similar latitudes also survived several close approaches. Several of the long-lived features also exhibited equatorward drifts and latitudinal oscillations. Also persistent are a remarkable near-equatorial wave feature and global zonal band structure. We will present imagery, maps, and analyses of these phenomena.PMF and LAS acknowledge support from NASA Planetary Astronomy Program; PMF and LAS acknowledge funding and technical support from W. M. Keck Observatory. We thank those of Hawaiian ancestry on whose sacred mountain we are privileged to be guests. Without their generous hospitality none of our groundbased observations would have been possible.
Observational Study of Morphological Changes in Medium-mass Evolved Stars
NASA Astrophysics Data System (ADS)
Chong, Sze-Ning
2014-02-01
Medium-mass (or intermediate-mass) stars refer to main sequence stars with masses ranging from 0.4 to 8 solar masses. These stars are believed to finally evolve into the central stars of planetary nebulae (PNe) and white dwarfs. One of the fascinating aspects of PNe is their diverse morphology. To understand the mechanisms of the morphological changes from spherical circumstellar envelopes (CSEs) of asymptotic giant branch (AGB) stars to those forming highly diversified PNe, it is necessary to investigate the true three-dimensional (3D) morphology of PNe from two-dimensional images, and the short transition phase in-between the two phases should also be explored. "Water Fountain" (WF) sources belong to transition phase objects; they are AGB or post-AGB stars with collimated jets traced by high velocity water maser emissions in their CSEs. This thesis comprises of four chapters. The results can be divided into two major parts. Chapter 1 is the introduction on the related fields with brief reviews of previous observational studies on PNe and the rapidly evolving transition phase objects. Basic theories necessary for understanding the next chapters were also described, including those explaining the commonly observed Hα emission in PNe, the formation of multipolar PNe, the maser emission and the role of shock in circumstellar materials. The first major part of the results, about the morphological classification of multipolar PNe, is presented in Chapter 2. At the beginning of the chapter, the problems on the previous classification methods were pointed out. Then a three-lobed model was introduced. By changing the combination of the orientations of the three pairs of lobes, simulations using the model produced statistical results in classification and quantified the errors of misidentification. Assuming that all PNe observed have the true structure of three lobes, due to projection effect, only 49% of them would be correctly classified. 46% and 5% of them would be misclassified as quadrupolar and bipolar, respectively. Similar analyses for one-lobed and two- lobed models were also performed. The results can be generalized to cases with larger number of lobes. The modeled images were compared with the Hα images of real PNe obtained from the Hubble Space Telescope data archive. Moreover, the effects of sensitivity in observational instruments on morphological classification were demonstrated. Even with the same uniform density on the lobe surface, the resultant column density changes with the viewing angle. As a result, under low sensitivity, some parts of the lobes cannot be detected, leaving broken arcs instead of closed lobes. They may be commonly misidentified as features other than lobes. The second major part of the results, about the water masers in W43A, is presented in Chapter 3. Using the Very Long Baseline Array (VLBA) in the United States, water masers in W43A in thirteen epochs across about ten years were detected. Among the fifteen WFs ever discovered, W43A is the only one that has been observed for over a decade. The characteristic distribution patterns of maser features were analyzed with various tools such as variance-covariance matrix and positional cross-correlation coefficient to obtain the physical parameters of the fast bipolar gas outflow ejected from the star. The "traditional" precessing jet model assumes that the axis of the collimated outflow keeps precessing like a spinning top, and the jet excites masers at its tip. However, there are some bow-shaped patterns of maser features that do not agree with this model; instead, they are more consistent with a cavity model - a halo with a bipolar evacuated volume whose thick wall was further pushed by an inside second collimated outflow. The cavity model is able to reproduce bow-shaped patterns, not only in W43A but also other WFs. It takes column density into account, which is essential in maser amplification. It is also more closely related to the mid-infrared morphology of W43A. Moreover, the features were identified to be concentrated in six groups located at discrete distances from the geometric center. It is believed that they reveal the mass loss history of the central star of W43A. In Chapter 4, simulation results for future observations are presented and the results of this thesis are summarized. The cavity model introduced in Chapter 3 should be tested using the newly developed instruments such as the Atacama Large Millimeter/submillimeter Array (ALMA) with its high spatial resolution and sensitivity. The reconstruction of the true 3D structure of PNe represents the first step in the identification of the physical processes responsible for the shaping of PNe, and the results of W43A demonstrated how water maser observations could be utilized to study early 3D morphological changes in PNe. Maser sizes are of the order of milli-arcseconds, suggesting an extremely high-resolution aspect to be explored for probing the inner regions of CSEs in evolved stars. They move with such high velocities over 100 km s-1 that observation intervals at a few months are enough to detect significant motions. With high resolving power and sensitivity of observational instruments available, it is not surprising to predict that WFs will be the key to solve the morphological formation mysteries of PNe.
Barbosa, M; Vieira, E P; Quintão, C C A; Normando, D
2016-08-01
To evaluate facial morphology of non-mixed indigenous people living in the Xingu region. Studies on these populations report that the total genetic diversity is as high as that observed for other continental populations. On the other hand, eating habits are different between indigenous and urban population, as indigenous people still have traditional habits. The sample consisted of 106 indigenous subjects, in permanent dentition stage, belonging to four groups: Arara-Laranjal (n = 35), Arara-Iriri (n = 20), Xikrin-Kaiapó (n = 24), and Assurini (n = 27). Standardized facial photographs were obtained, and fourteen measurements were analyzed. Intra- and intergroup homogeneities were examined by discriminant analysis, followed by anova and Kruskal-Wallis tests. Sexual dimorphism to each village was analyzed by Student's t-test or Mann-Whitney test, at p < 0.05. Significant facial differences were found between male and female, indicating that sex data should not be grouped for intergroup comparison. Discriminant analysis showed a large intergroup heterogeneity, while an intragroup homogeneity was found, especially for females. It was also observed that some morphological features of the face are specific to some villages, regardless of ethnicity. Facial morphological characteristics were strongly different among groups, even comparing villages from the same ethnicity. Furthermore, a low diversity within groups was observed. Our findings, supported by previous reports on genetics and eating habits in these populations, reinforce the role of the genetic determination on craniofacial morphology. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.
In vivo multimodal nonlinear optical imaging of mucosal tissue
NASA Astrophysics Data System (ADS)
Sun, Ju; Shilagard, Tuya; Bell, Brent; Motamedi, Massoud; Vargas, Gracie
2004-05-01
We present a multimodal nonlinear imaging approach to elucidate microstructures and spectroscopic features of oral mucosa and submucosa in vivo. The hamster buccal pouch was imaged using 3-D high resolution multiphoton and second harmonic generation microscopy. The multimodal imaging approach enables colocalization and differentiation of prominent known spectroscopic and structural features such as keratin, epithelial cells, and submucosal collagen at various depths in tissue. Visualization of cellular morphology and epithelial thickness are in excellent agreement with histological observations. These results suggest that multimodal nonlinear optical microscopy can be an effective tool for studying the physiology and pathology of mucosal tissue.
The comparative morphology of pit organs in elasmobranchs.
Peach, M B; Marshall, N J
2009-06-01
The pit organs of elasmobranchs (sharks, skates and rays) are free neuromasts of the mechanosensory lateral line system. Pit organs, however, appear to have some structural differences from the free neuromasts of bony fishes and amphibians. In this study, the morphology of pit organs was investigated by scanning electron microscopy in six shark and three ray species. In each species, pit organs contained typical lateral line hair cells with apical stereovilli of different lengths arranged in an "organ-pipe" configuration. Supporting cells also bore numerous apical microvilli taller than those observed in other vertebrate lateral line organs. Pit organs were either covered by overlapping denticles, located in open grooves bordered by denticles, or in grooves without associated denticles. The possible functional implications of these morphological features, including modification of water flow and sensory filtering properties, are discussed.
Yates, Bonnie C; Espinoza, Edgard O; Baker, Barry W
2010-09-01
Here we present methods for distinguishing tail hairs of African elephants (Loxodonta africana), Asian elephants (Elephas maximus), and giraffes (Giraffa camelopardalis) from forensic contexts. Such hairs are commonly used to manufacture jewelry artifacts that are often sold illegally in the international wildlife trade. Tail hairs from these three species are easily confused macroscopically, and morphological methods for distinguishing African and Asian tail hairs have not been published. We used cross section analysis and light microscopy to analyze the tail hair morphology of 18 individual African elephants, 18 Asian elephants, and 40 giraffes. We found that cross-sectional shape, pigment placement, and pigment density are useful morphological features for distinguishing the three species. These observations provide wildlife forensic scientists with an important analytical tool for enforcing legislation and international treaties regulating the trade in elephant parts.
NASA Astrophysics Data System (ADS)
Vincent, J.; Oklay, N.; Marchi, S.; Höfner, S.; Sierks, H.
2014-07-01
This paper reviews the observations of crater-like features on cometary nuclei. ''Pits'' have been observed on almost all cometary nuclei but their origin is not fully understood [1,2,3,4]. It is currently assumed that they are created mainly by the cometary activity with a pocket of volatiles erupting under a dust crust, leaving a hole behind. There are, however, other features which cannot be explained in this way and are interpreted alternatively as remnants of impact craters. This work focusses on the second type of pit features: impact craters. We present an in-depth review of what has been observed previously and conclude that two main types of crater morphologies can be observed: ''pit-halo'' and ''sharp pit''. We extend this review by a series of analysis of impact craters on cometary nuclei through different approaches [5]: (1) Probability of impact: We discuss the chances that a Jupiter Family Comet like 9P/Tempel 1 or the target of Rosetta 67P/Churyumov-Gerasimenko can experience an impact, taking into account the most recent work on the size distribution of small objects in the asteroid Main Belt [6]. (2) Crater morphology from scaling laws: We present the status of scaling laws for impact craters on cometary nuclei [7] and discuss their strengths and limitations when modeling what happens when a rocky projectile hits a very porous material. (3) Numerical experiments: We extend the work on scaling laws by a series of hydrocode impact simulations, using the iSALE shock physics code [8,9,10] for varying surface porosity and impactor velocity (see Figure). (4) Surface processes and evolution: We discuss finally the fate of the projectile and the effects of the impact-induced surface compaction on the activity of the nucleus. To summarize, we find that comets do undergo impacts although the rapid evolution of the surface erases most of the features and make craters difficult to detect. In the case of a collision between a rocky body and a highly porous cometary nucleus, two specific crater morphologies can be formed: a central pit surrounded by a shallow depression, or a pit, deeper than typical craters observed on rocky surfaces. After the impact, it is likely that a significant fraction of the projectile will remain in the crater. During its two years long escort of comet 67P/Churyumov-Gerasimenko, ESA's Rosetta mission should be able to detect specific silicate signatures on the bottom of craters or crater-like features, as evidence of this contamination. For large craters, structural changes in the impacted region, in particular, compaction of material, will affect the local activity. The increase of tensile strength can stop the activity by preventing the gas from lifting up dust grains. On the other hand, material compaction can help the heat flux to travel deeper in the nucleus, potentially reaching unexposed pockets of volatiles, and therefore increasing the activity [11]. Ground truth data from Rosetta will help us infer the relative importance of those two effects.
Galaxy Zoo: Infrared and Optical Morphology
NASA Astrophysics Data System (ADS)
Carla Shanahan, Jesse; Lintott, Chris; Zoo, Galaxy
2018-01-01
We present the detailed, visual morphologies of approximately 60,000 galaxies observed by the UKIRT Infrared Deep Sky Survey and then classified by participants in the Galaxy Zoo project. Our sample is composed entirely of nearby objects with redshifts of z ≤ 0.3, which enables us to robustly analyze their morphological characteristics including smoothness, bulge properties, spiral structure, and evidence of bars or rings. The determination of these features is made via a consensus-based analysis of the Galaxy Zoo project data in which inconsistent and outlying classifications are statistically down-weighted. We then compare these classifications of infrared morphology to the objects’ optical classifications in the Galaxy Zoo 2 release (Willett et al. 2013). It is already known that morphology is an effective tool for uncovering a galaxy’s dynamical past, and previous studies have shown significant correlations with physical characteristics such as stellar mass distribution and star formation history. We show that majority of the sample has agreement or expected differences between the optical and infrared classifications, but also present a preliminary analysis of a subsample of objects with striking discrepancies.
Ishikawa, Masahiro; Murakami, Yuri; Ahi, Sercan Taha; Yamaguchi, Masahiro; Kobayashi, Naoki; Kiyuna, Tomoharu; Yamashita, Yoshiko; Saito, Akira; Abe, Tokiya; Hashiguchi, Akinori; Sakamoto, Michiie
2016-01-01
Abstract. This paper proposes a digital image analysis method to support quantitative pathology by automatically segmenting the hepatocyte structure and quantifying its morphological features. To structurally analyze histopathological hepatic images, we isolate the trabeculae by extracting the sinusoids, fat droplets, and stromata. We then measure the morphological features of the extracted trabeculae, divide the image into cords, and calculate the feature values of the local cords. We propose a method of calculating the nuclear–cytoplasmic ratio, nuclear density, and number of layers using the local cords. Furthermore, we evaluate the effectiveness of the proposed method using surgical specimens. The proposed method was found to be an effective method for the quantification of the Edmondson grade. PMID:27335894
Petryński, Wojciech; Palkowska, Katarzyna; Prusik, Magdalena; Targońska, Krystyna; Giżejewski, Zygmunt; Przybylska-Gornowicz, Barbara
2014-01-01
Anatomical, histological, and ultrastructural studies of the European beaver stomach revealed several unique morphological features. The prominent attribute of its gross morphology was the cardiogastric gland (CGG), located near the oesophageal entrance. Light microscopy showed that the CGG was formed by invaginations of the mucosa into the submucosa, which contained densely packed proper gastric glands comprised primarily of parietal and chief cells. Mucous neck cells represented <0.1% of cells in the CGG gastric glands and 22–32% of cells in the proper gastric glands of the mucosa lining the stomach lumen. These data suggest that chief cells in the CGG develop from undifferentiated cells that migrate through the gastric gland neck rather than from mucous neck cells. Classical chief cell formation (i.e., arising from mucous neck cells) occurred in the mucosa lining the stomach lumen, however. The muscularis around the CGG consisted primarily of skeletal muscle tissue. The cardiac region was rudimentary while the fundus/corpus and pyloric regions were equally developed. Another unusual feature of the beaver stomach was the presence of specific mucus with a thickness up to 950 µm (in frozen, unfixed sections) that coated the mucosa. Our observations suggest that the formation of this mucus is complex and includes the secretory granule accumulation in the cytoplasm of pit cells, the granule aggregation inside cells, and the incorporation of degenerating cells into the mucus. PMID:24727802
Chao, Li-Lian; Lu, Chun-Wei; Lin, Ying-Fang; Shih, Chien-Ming
2017-04-01
Genetic identity and morphological features of a human biting tick, Amblyomma testudinarium, were determined for the first time in Taiwan. Morphological features of adult male and female ticks of Am. testudinarium were observed and photographed by a stereo- microscope. The genetic identity was analyzed by comparing the sequences of mitochondrial 16S ribosomal DNA gene obtained from 18 strains of ticks representing 10 species of Amblyomma, and four outgroup species of Dermacentor and Rhipicephalus ticks. Nine major clades could be easily distinguished by neighbour-joining analysis and were congruent by maximum-parsimony method. All these Am. testudinarium ticks collected from Taiwan and Japan were genetically affiliated to a monophyletic group with highly homogeneous sequence (99.8-100% similarity), and can be discriminated from other species of Amblyomma and other genera of ticks (Dermacentor and Rhipicephalus) with a sequence divergence ranging from 6.9 to 23.9%. Moreover, intra- and inter-species analysis based on the genetic distance (GD) values indicated a lower level (GD < 0.003) within the same lineage of Am. testudinarium ticks collected from Taiwan and Japan, as compared with other lineage groups (GD > 0.108) of Amblyomma ticks, as well as outgroup (GD > 0.172) species. Our results provide the first distinguished features of adult Am. testudinarium ticks and the first genetic identification of Am. testudinarium ticks collected from humans in Taiwan. Seasonal prevalence, host range, and vectorial capacity of this tick species in Taiwan need to be further clarified.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Lesz, Sabina, E-mail: sabina.lesz@polsl.pl
The experiments demonstrate that ductility of the samples of bulk metallic glass (BMG) with the same chemical composition increased with decreasing sample size. It is shown that microhardness and density increases with decreasing the cooling rate. The fracture morphology of rods after compressive fracture were different on the cross section. Two characteristic features of the compressive fracture morphologies of metallic glasses (MGs) were observed in samples: smooth region and the vein pattern. Many parallel shear bands were observed on the deformed specimen with ϕ = 2 mm in diameter. The results provide more understanding on the relationship among the coolingmore » rate, structure and micro-indentation behavior of the Fe-Co-based BMGs. - Highlights: •Fracture morphology and micro-indentation behavior is studied. •The smaller BMG sample exhibits the larger plasticity. •Microhardness and density increase with decreasing the cooling rate. •Formation of shear bands has been reported in deformed specimens. •Structure and mechanical properties of BMGs can be controlled by the cooling rate.« less
Redescription of Strombidium oculatum Gruber 1884 (Ciliophora, Oligotrichia).
Montagnes, David J S; Lowe, Chris D; Poultonb, Alex; Jonsson, Per R
2002-01-01
The marine, tide pool-dwelling ciliate Stombidium oculatum was redescribed using live, stained, SEM, and TEM material prepared from samples collected from pools on the Isle of Man (Irish Sea) and Brittany (France). Also, we reviewed the older German and French works that reported on ciliates collected in the Mediterranean and Brittany, respectively. The Brittany and Isle of Man populations of the ciliate were considered identical. Some morphological and behavioural differences exist between the Brittany-Isle of Man populations and the Mediterranean populations, but they were insufficient to distinguish different taxa. Thus, taxa from all three locations were considered to be conspecific. Key features used to describe the ciliate were: morphology and ultrastructure of the free-swimming ciliate; cyst morphology; presence of mixotrophic-chloroplasts; presence of an eye spot composed of stigma obtained from chlorophyte prey; division, morphogenesis, and nuclear structure; live observations and behaviour, including the encystment-excystment cycle. Based on morphological and behavioural characteristics the taxon was distinguished from other similar species, and a neotype has been designated as no type material exists.
Bulk and Surface Morphologies of ABC Miktoarm Star Terpolymers Composed of PDMS, PI, and PMMA Arms
Chernyy, Sergey; Kirkensgaard, Jacob Judas Kain; Mahalik, Jyoti P.; ...
2018-02-02
DIM miktoarm star copolymers, composed of polydimethylsiloxane [D], poly(1,4-isoprene) [I], and poly(methyl methacrylate) [M], were synthesized using a newly developed linking methodology with 4-allyl-1,1-diphenylethylene as a linking agent. The equilibrium bulk morphologies of the DIM stars were found to range from [6.6.6] tiling patterns to alternating lamellar and alternating cylindrical morphologies, as determined experimentally by small-angle X-ray scattering and transmission electron microscopy and confirmed by dissipative particle dynamics and self-consistent field theory based arguments. The thin film morphologies, which differ from those found in the bulk, were identified by scanning electron microscopy, coupled with oxygen plasma etching. Finally, square arraysmore » of the PDMS nanodots and empty core cylinders were formed on silica after oxygen plasma removal of the poly(1,4-isoprene) and poly(methyl methacrylate) which generated nanostructured substrates decorated with these features readily observable.« less
Exploring the X-ray Morphology of the Supernova Remnant Kes 27 using Numerical Simulations
NASA Astrophysics Data System (ADS)
Dwarkadas, Vikram; Dewey, D.
2013-04-01
Kesteven 27 is a member of the class of thermal composite or mixed-morphology remnants, which can show thermal X-ray emission extending all the way in towards the center. The Chandra image shows two incomplete shell-like features in the north-eastern half, with brightness fading towards the southwest. The X-ray and radio structure led Chen et al. (2008) to suggest that the morphology represents a supernova remnant expanding in a windblown bubble. The two X-ray rings represent the outer shock of the supernova remnant, and a reflected shock arising from collision with a dense shell. Using numerical simulations followed by a computation of the X-ray emission, we explore this possibility. Our initial modeling suggests that the scenario discussed by Chen et al. (2008) may not work. We suggest and discuss modifications to this scenario that may be able to reproduce the observed morphology, and the implications for thermal composite remnants.
Bulk and Surface Morphologies of ABC Miktoarm Star Terpolymers Composed of PDMS, PI, and PMMA Arms
DOE Office of Scientific and Technical Information (OSTI.GOV)
Chernyy, Sergey; Kirkensgaard, Jacob Judas Kain; Mahalik, Jyoti P.
DIM miktoarm star copolymers, composed of polydimethylsiloxane [D], poly(1,4-isoprene) [I], and poly(methyl methacrylate) [M], were synthesized using a newly developed linking methodology with 4-allyl-1,1-diphenylethylene as a linking agent. The equilibrium bulk morphologies of the DIM stars were found to range from [6.6.6] tiling patterns to alternating lamellar and alternating cylindrical morphologies, as determined experimentally by small-angle X-ray scattering and transmission electron microscopy and confirmed by dissipative particle dynamics and self-consistent field theory based arguments. The thin film morphologies, which differ from those found in the bulk, were identified by scanning electron microscopy, coupled with oxygen plasma etching. Finally, square arraysmore » of the PDMS nanodots and empty core cylinders were formed on silica after oxygen plasma removal of the poly(1,4-isoprene) and poly(methyl methacrylate) which generated nanostructured substrates decorated with these features readily observable.« less
A galactic microquasar mimicking winged radio galaxies.
Martí, Josep; Luque-Escamilla, Pedro L; Bosch-Ramon, Valentí; Paredes, Josep M
2017-11-24
A subclass of extragalactic radio sources known as winged radio galaxies has puzzled astronomers for many years. The wing features are detected at radio wavelengths as low-surface-brightness radio lobes that are clearly misaligned with respect to the main lobe axis. Different models compete to account for these peculiar structures. Here, we report observational evidence that the parsec-scale radio jets in the Galactic microquasar GRS 1758-258 give rise to a Z-shaped radio emission strongly reminiscent of the X and Z-shaped morphologies found in winged radio galaxies. This is the first time that such extended emission features are observed in a microquasar, providing a new analogy for its extragalactic relatives. From our observations, we can clearly favour the hydrodynamic backflow interpretation against other possible wing formation scenarios. Assuming that physical processes are similar, we can extrapolate this conclusion and suggest that this mechanism could also be at work in many extragalactic cases.
Argot, Christine
2002-07-01
This article analyzes the adaptations of the hindlimb of two Early Paleocene marsupials, Mayulestes ferox and Pucadelphys andinus. This analysis is based on detailed comparisons with various extant marsupials, both South American and Australian. In the case of the South American opossums, original myological data were collected and osteological-myological associations were related to their locomotor behavior. The use of Australian genera helped to improve the appraisal of the locomotory habits of the fossil taxa. Several features are indicative of the ability of Mayulestes to climb or walk on uneven surfaces (e.g., very mobile hip joint, astragalocalcaneal joint pattern), and some other features emphasize a relative agility (e.g., strongly everted iliac blades, morphology of the distal epiphysis of the femur, medially stabilized cruroastragalar joint). Pucadelphys exhibits a hindlimb relatively similar morphologically to that of Mayulestes, but with features indicating slightly increased agility and a terrestrial component that is more emphasized than in Mayulestes. The Tiupampa fossils were therefore more agile than most living didelphids and resembled the condition observed in living dasyurids more. These conclusions complement a previous study performed on the forelimb of these fossils. Copyright 2002 Wiley-Liss, Inc.
DETECTION OF SHARP SYMMETRIC FEATURES IN THE CIRCUMBINARY DISK AROUND AK Sco
DOE Office of Scientific and Technical Information (OSTI.GOV)
Janson, Markus; Asensio-Torres, Ruben; Thalmann, Christian
The Search for Planets Orbiting Two Stars survey aims to study the formation and distribution of planets in binary systems by detecting and characterizing circumbinary planets and their formation environments through direct imaging. With the SPHERE Extreme Adaptive Optics instrument, a good contrast can be achieved even at small (<300 mas) separations from bright stars, which enables studies of planets and disks in a separation range that was previously inaccessible. Here, we report the discovery of resolved scattered light emission from the circumbinary disk around the well-studied young double star AK Sco, at projected separations in the ∼13–40 AU range. Themore » sharp morphology of the imaged feature is surprising, given the smooth appearance of the disk in its spectral energy distribution. We show that the observed morphology can be represented either as a highly eccentric ring around AK Sco, or as two separate spiral arms in the disk, wound in opposite directions. The relative merits of these interpretations are discussed, as well as whether these features may have been caused by one or several circumbinary planets interacting with the disk.« less
Did ice streams carve martian outflow channels?
Lucchitta, B.K.; Anderson, D.M.; Shoji, H.
1981-01-01
Outflow channels on Mars1 are long sinuous linear depressions that occur mostly in the equatorial area (??30?? lat.). They differ from small valley networks2 by being larger and arising full born from chaotic terrains. Outflow channels resemble terrestrial stream beds, and their origin has generally been attributed to water3-5 in catastrophic floods6,7 or mudflows8. The catastrophic-flood hypothesis is derived primarily from the morphological similarities of martian outflow channels and features created by the catastrophic Spokane flood that formed the Washington scablands. These similarities have been documented extensively3,6,7, but differences of scale remain a major problemmartian channel features are on the average much larger than their proposed terrestrial analogues. We examine here the problem of channel origin from the perspective of erosional characteristics and the resultant landf orms created by former and present-day ice streams and glaciers on Earth. From morphologic comparisons, an ice-stream origin seems equally well suited to explain the occurrences and form of the outflow channels on Mars, and in contrast with the hydraulic hypothesis, ice streams and ice sheets produce terrestrial features of the same scale as those observed on Mars. ?? 1981 Nature Publishing Group.
Cellular Scale Anisotropic Topography Guides Schwann Cell Motility
Mitchel, Jennifer A.; Hoffman-Kim, Diane
2011-01-01
Directed migration of Schwann cells (SC) is critical for development and repair of the peripheral nervous system. Understanding aspects of motility specific to SC, along with SC response to engineered biomaterials, may inform strategies to enhance nerve regeneration. Rat SC were cultured on laminin-coated microgrooved poly(dimethyl siloxane) platforms that were flat or presented repeating cellular scale anisotropic topographical cues, 30 or 60 µm in width, and observed with timelapse microscopy. SC motion was directed parallel to the long axis of the topography on both the groove floor and the plateau, with accompanying differences in velocity and directional persistence in comparison to SC motion on flat substrates. In addition, feature dimension affected SC morphology, alignment, and directional persistence. Plateaus and groove floors presented distinct cues which promoted differential motility and variable interaction with the topographical features. SC on the plateau surfaces tended to have persistent interactions with the edge topography, while SC on the groove floors tended to have infrequent contact with the corners and walls. Our observations suggest the capacity of SC to be guided without continuous contact with a topographical cue. SC exhibited a range of distinct motile morphologies, characterized by their symmetry and number of extensions. Across all conditions, SC with a single extension traveled significantly faster than cells with more or no extensions. We conclude that SC motility is complex, where persistent motion requires cellular asymmetry, and that anisotropic topography with cellular scale features can direct SC motility. PMID:21949703
NASA Technical Reports Server (NTRS)
Fuerst, Steven V.; Mizuno, Yosuke; Nishikawa, Ken-Ichi; Wu, Kinwah
2007-01-01
We have calculated the emission from relativistic flows in black hole systems using a fully general relativistic radiative transfer, with flow structures obtained by general relativistic magnetohydrodynamic simulations. We consider thermal free-free emission and thermal synchrotron emission. Bright filament-like features are found protruding (visually) from the accretion disk surface, which are enhancements of synchrotron emission when the magnetic field is roughly aligned with the line-of-sight in the co-moving frame. The features move back and forth as the accretion flow evolves, but their visibility and morphology are robust. We propose that variations and location drifts of the features are responsible for certain X-ray quasi-periodic oscillations (QPOs) observed in black-hole X-ray binaries.
NASA Astrophysics Data System (ADS)
Chockalingam, Letchumanan
2005-01-01
The data of Gunung Ledang region of Malaysia acquired through LANDSAT are considered to map certain hydrogeolocial features. To map these significant features, image-processing tools such as contrast enhancement, edge detection techniques are employed. The advantages of these techniques over the other methods are evaluated from the point of their validity in properly isolating features of hydrogeolocial interest are discussed. As these techniques take the advantage of spectral aspects of the images, these techniques have several limitations to meet the objectives. To discuss these limitations, a morphological transformation, which generally considers the structural aspects rather than spectral aspects from the image, are applied to provide comparisons between the results derived from spectral based and the structural based filtering techniques.
Fluid Mechanical Properties of Silkworm Fibroin Solutions
NASA Astrophysics Data System (ADS)
Matsumoto, Akira
2005-11-01
The aqueous solution behavior of silk fibroin is of interest due to the assembly and processing of this protein related to the spinning of protein fibers that exhibit remarkable mechanical properties. To gain insight into the origins of this functional feature, it is desired to determine how the protein behaves under a range of solution conditions. Pure fibroin at different concentrations in water was studied for surface tension, as a measure of surfactancy. In addition, shear induced changes on these solutions in terms of structure and morphology was also determined. Fibroin solutions exhibited shear rate-sensitive viscosity changes and precipitated at a critical shear rate where a dramatic increase of 75-150% of the initial value was observed along with a decrease in viscosity. In surface tension measurements, critical micelle concentrations were in the range of 3-4% w/v. The influence of additional factors, such as sericin protein, divalent and monovalent cations, and pH on the solution behavior in relation to structural and morphological features will also be described.
Mascarin, Gabriel Moura; Guarín-Molina, Juan Humberto; Arthurs, Steven Paul; Humber, Richard Alan; de Andrade Moral, Rafael; Demétrio, Clarice Garcia Borges; Delalibera, Ítalo
2016-09-01
We describe symptoms of mycosis induced by two native fungal entomopathogens of the citrus orthezia scale, Praelongorthezia praelonga (Hemiptera: Ortheziidae), an important pest of citrus orchards. The data presented in this article are related to the article entitled "Seasonal prevalence of the insect pathogenic fungus Colletotrichum nymphaeae in Brazilian citrus groves under different chemical pesticide regimes" [1]. The endemic fungal pathogen, C. nymphaeae, emerges through the thin cuticular intersegmental regions of the citrus orthezia scale body revealing orange salmon-pigmented conidiophores bearing conidial masses, as well as producing rhizoid-like hyphae that extend over the citrus leaf. By contrast, nymphs or adult females of this scale insect infected with Lecanicillium longisporum exhibit profuse outgrowth of bright white-pigmented conidiophores with clusters of conidia emerging from the insect intersegmental membranes, and mycosed cadavers are commonly observed attached to the leaf surface by hyphal extensions. These morphological differences are important features to discriminate these fungal entomopathogens in citrus orthezia scales.
Measurements of Cuspal Slope Inclination Angles in Palaeoanthropological Applications
NASA Astrophysics Data System (ADS)
Gaboutchian, A. V.; Knyaz, V. A.; Leybova, N. A.
2017-05-01
Tooth crown morphological features, studied in palaeoanthropology, provide valuable information about human evolution and development of civilization. Tooth crown morphology represents biological and historical data of high taxonomical value as it characterizes genetically conditioned tooth relief features averse to substantial changes under environmental factors during lifetime. Palaeoanthropological studies are still based mainly on descriptive techniques and manual measurements of limited number of morphological parameters. Feature evaluation and measurement result analysis are expert-based. Development of new methods and techniques in 3D imaging creates a background provides for better value of palaeoanthropological data processing, analysis and distribution. The goals of the presented research are to propose new features for automated odontometry and to explore their applicability to paleoanthropological studies. A technique for automated measuring of given morphological tooth parameters needed for anthropological study is developed. It is based on using original photogrammetric system as a teeth 3D models acquisition device and on a set of algorithms for given tooth parameters estimation.
NASA Astrophysics Data System (ADS)
Maturilli, A.; Ferrari, S.; Helbert, J.; D'Incecco, P.; D'Amore, M.
2011-12-01
In the Planetary Emissivity Laboratory (PEL) at the Institute for Planetary Research of the German Aerospace Center (DLR) in Berlin, we set-up a simulation chamber for the spectroscopic investigation of minerals separates under Mercurial conditions. The chamber can be evacuated to 10-4 bar and the target samples heated to 700 K within few minutes, thanks to the innovative inductive heating system. While developing the protocol for the high temperature spectroscopy measurements we discovered interesting "morphologies" on the sample surfaces. The powders are poured into stainless steel cups of 50 mm internal diameter, 8 mm height and 3 mm depth, having a 5 mm thick base (thus leaving 3 mm free space for the minerals), and rim 1 mm thick. We selected several minerals of interest for Mercurial surface composition and for each of them we analyzed various grain size separates, to study the influence of grain dimensions to the process of thermal stressing. We observed that for the smaller grain size separate (0-25 μm) the thermal stress mainly induces large depressions and fractures, while on larger grain sizes (125-250 μm) small depressions and a cratered surface. Our current working hypothesis is that these features are mainly caused by thermal stress induced by a radiatively quickly cooling surface layer covering the much hotter bulk material. Further investigation is ongoing to understand the processes better. The observed morphologies exhibit surprising similarities to features observed at planetary scale size for example on Mercury and even on Venus. Especially the high resolution images provided currently from MESSENGER'S Mercury Dual Imaging System (MDIS) instrument has revealed plains dominated by polygonal fractures whose origin still have to be determined. Our laboratory analogue studies might in the future provide some insight into the processes creating those features
Aeromonas hydrophila exotoxin induces cytoplasmic vacuolation and cell death in VERO cells.
Di Pietro, Angela; Picerno, Isa; Visalli, Giuseppa; Chirico, Cristina; Spataro, Pasquale; Cannavò, Giuseppe; Scoglio, Maria E
2005-07-01
Many organisms are able to cause cell vacuolation, but it is unclear if this can be considered a step of apoptosis or necrosis, or a distinct form of cell death. In this study VERO cells were used to evaluate the relationship between vacuolation and cell death pattern caused by exotoxins produced by environmental strains of A. hydrophila. Cell damage has been evaluated morphologically as well as biochemically. Cytotoxic and vacuolating titres were strictly correlated and the vacuolation has to be considered an early indicator of cytotoxicity that causes cell apoptosis or necrosis in relation to the dose. Signs of apoptosis (chromatin condensation and blebbing) were observed at low concentration and TGase activity, referable to apoptosis induction, confirms morphological observations. In fact, putrescine incorporation was related both to cytotoxin concentration and time of incubation. Moreover, the observed doubling cells with necrotic features permit us to suppose that cell sensitivity and death pattern could change during the different phases of cellular cycle.
Lidar observations of wind- and wave-driven morphological evolution of coastal foredunes
NASA Astrophysics Data System (ADS)
Spore, N.; Brodie, K. L.; Kershner, C. M.
2016-02-01
Coastal foredunes are continually evolving geomorphic features that are slowly built up by wind-blown sand and rapidly eroded during storms by large waves and swash. Landward aeolian transport removes sediment from the active beach and surf-zone, trapping it in the dune, where as coastal erosion both removes sediment from the dune and can decrease the overall fetch and sediment supply available to the dune. Understanding how wave and wind-driven process interact with each other and the dune-beach system itself is a critical component of improving predictions of coastal evolution. To investigate these processes, two 50 m alongshore by 25 m cross-shore patches of dune along an open coast beach fronting the Atlantic Ocean in Duck, NC were scanned with a high resolution terrestrial lidar scanner ( 5000 points per m^2) every three weeks over the last year to observe detailed morphological evolution of the dune and upper beach. Sequential scans were co-registered to each other using fixed objects in the field of view, significantly increasing precision and accuracy of the observations. The north study site featured a 7.5 m tall scarped foredune system, where as the southern study site featured a 6 m tall, hummocky, prograding foredune. Initial analyses show large accretion events on the southern prograding site. For example, during one three week period in February, portions of the site accreted over 40 cm. In contrast, during the same three week period at the northern site (less than 1 km away), response was alongshore variable with erosion and accretion of roughly 10 cm on the foredune face. Further analysis will focus on separating wind vs. wave driven evolution of these sites. Funded by the USACE Coastal Inlets Research Program.
Sturiale, C L; Rigante, L; Puca, A; Di Lella, G; Albanese, A; Marchese, E; Di Rocco, C; Maira, G; Colicchio, G
2013-05-01
Epileptic seizures account for 24-40% of all clinical onsets in patients with brain arteriovenous malformations (AVMs). We retrospectively reviewed the angioarchitectural features of AVMs associated with seizures in 168 patients admitted to our Department from 1997 to 2012. Patients were dichotomized according to demographic characteristics, type of treatment, bleeding occurrence, and morphological and topographic features. Clinical status at admission and discharge was also recorded. The association of each one of these variables with seizures occurrence was statistically tested. Continuous variables and outcome were compared with Student's t-test, whereas categorical ones were compared using Fisher's exact test. The independent contribution of some seizures predictors was assessed with a logistic regression model. Associations were considered significant for P < 0.05. About 29% patients showed seizures and 47% bleeding. No significant difference in age and sex was observed between patients with and without seizures. AVMs > 4 cm (P = 0.001) and those fed by dilated arterial feeders (P = 0.02) were associated with increased risk of seizures. A higher risk of seizures occurrence was also observed in cortical AVMs compared with deeper ones (75.5% vs. 55.4%; P = 0.01), and in AVMs fed by middle and posterior cerebral arteries branches compared with the other vessels (81.6% vs. 45.3%; P < 0.001 and 48.9% vs. 23.5%; P = 0.002, respectively). No lobar predisposition was observed. A nidus > 4 cm also appeared as an independent risk factor of seizures occurrence (OR 2.82; 95% CI, 1.26-6.31; P = 0.009) at logistic regression analysis. AVM morphology, especially nidus dimension, appeared to more significantly influence seizures occurrence than their topography. © 2013 The Author(s) European Journal of Neurology © 2013 EFNS.
Selby, Michael S; Simpson, Scott W; Lovejoy, C Owen
2016-05-01
Previously, we described several features of the carpometacarpal joints in extant large-bodied apes that are likely adaptations to the functional demands of vertical climbing and suspension. We observed that all hominids, including modern humans and the 4.4-million-year-old hominid Ardipithecus ramidus, lacked these features. Here, we assess the uniqueness of these features in a large sample of monkey, ape, and human hands. These new data provide additional insights into the functional adaptations and evolution of the anthropoid hand. Our survey highlights a series of anatomical adaptations that restrict motion between the second and third metacarpals (MC2 and MC3) and their associated carpals in extant apes, achieved via joint reorganization and novel energy dissipation mechanisms. Their hamate-MC4 and -MC5 joint surface morphologies suggest limited mobility, at least in Pan. Gibbons and spider monkeys have several characters (angled MC3, complex capitate-MC3 joint topography, variably present capitate-MC3 ligaments) that suggest functional convergence in response to suspensory locomotion. Baboons have carpometacarpal morphology suggesting flexion/extension at these joints beyond that observed in most other Old World monkeys, probably as an energy dissipating mechanism minimizing collision forces during terrestrial locomotion. All hominids lack these specializations of the extant great apes, suggesting that vertical climbing was never a central feature of our ancestral locomotor repertoire. Furthermore, the reinforced carpometacarpus of vertically climbing African apes was likely appropriated for knuckle-walking in concert with other novel potential energy dissipating mechanisms. The most parsimonious explanation of the structural similarity of these carpometacarpal specializations in great apes is that they evolved independently. © 2016 Wiley Periodicals, Inc.
NASA Astrophysics Data System (ADS)
Génio, Luciana; Kiel, Steffen; Cunha, Marina R.; Grahame, John; Little, Crispin T. S.
2012-06-01
The increasing number of bathymodiolin mussel species being described from deep-sea chemosynthetic environments worldwide has raised many questions about their evolutionary history, and their systematics is still being debated. Mussels are also abundant in fossil chemosynthetic assemblages, but their identification is problematic due to conservative shell morphology within the group and preservation issues. Potential resolution of bathymodiolin taxonomy requires new character sets, including morphological features that are likely to be preserved in fossil specimens. To investigate the phylogenetic significance of shell microstructural features, we studied the shell microstructure and mineralogy of 10 mussel species from hydrothermal vents and hydrocarbon seeps, and 15 taxa from sunken wood and bone habitats, and compared these observations with current molecular phylogenies of the sub-family Bathymodiolinae. In addition, we analyzed the shell microstructure in Adipicola chickubetsuensis from fossil whale carcasses, and in Bathymodiolus cf. willapaensis and “Modiola exbrocchii” from fossil cold seeps, and discussed the usefulness of these characters for identification of fossil chemosymbiotic mussels. Microstructural shell features are quite uniform among vent, seep, wood and bone mussel taxa, and therefore established bathymodiolin lineages cannot be discriminated, nor can the relations between fossil and modern species be determined with these characters. Nevertheless, the uniformity of shell microstructures observed among chemosymbiotic mussels and the similarity with its closest relative, Modiolus modiolus, does not challenge the monophyly of the group. Slight differences are found between the large vent and seep mussels and the small mytilids commonly found in habitats enriched in organic matter. Together with previous data, these results indicate that a repeated pattern of paedomorphism characterizes the evolutionary history of deep-sea mussels, and the occurrence of neotenous features should be considered in the taxonomic revision of this group.
Observational Evidence of a Flux Rope within a Sunspot Umbra
DOE Office of Scientific and Technical Information (OSTI.GOV)
Guglielmino, Salvo L.; Zuccarello, Francesca; Romano, Paolo, E-mail: salvo.guglielmino@oact.inaf.it
We observed an elongated filamentary bright structure inside the umbra of the big sunspot in active region NOAA 12529, which differs from the light bridges usually observed in sunspots for its morphology, magnetic configuration, and velocity field. We used observations taken with the Solar Dynamic Observatory satellite to characterize this feature. Its lifetime is 5 days, during which it reaches a maximum length of about 30″. In the maps of the vertical component of the photospheric magnetic field, a portion of the feature has a polarity opposite to that of the hosting sunspot. At the same time, in the entiremore » feature the horizontal component of the magnetic field is about 2000 G, substantially stronger than in the surrounding penumbral filaments. Doppler velocity maps reveal the presence of both upward and downward plasma motions along the structure at the photospheric level. Moreover, looking at the chromospheric level, we noted that it is located in a region corresponding to the edge of a small filament that seems rooted in the sunspot umbra. Therefore, we interpreted the bright structure as the photospheric counterpart of a flux rope touching the sunspot and giving rise to penumbral-like filaments in the umbra.« less
NASA Astrophysics Data System (ADS)
Kouzmanov, Kalin; Bailly, Laurent; Ramboz, Claire; Rouer, Olivier; Bény, Jean-Michel
2002-08-01
Pyrite samples from the Radka epithermal, replacement type, volcanic rock-hosted copper deposit, Bulgaria, have been studied using near-infrared (IR) microscopy. Two generations of pyrite based on their textures, composition and behaviour in IR light can be distinguished. Electron microprobe analyses, X-ray elemental mapping and Fourier transform infrared spectroscopy were used to study the relationship between crystal zoning, trace element contents and IR transmittance of pyrite. The observed crystal zoning is related to variable arsenic contents in massive fine-grained and colloform pyrite from the early pyrite-quartz assemblage, and cobalt contents in pyrite crystals from the late quartz-pyrite vein assemblage. There is a negative correlation between trace element content and IR transmittance of pyrite. The IR transparency of pyrite is thus a sensitive indicator of changes in trace element concentrations. Fluid inclusions have only been found in the second pyrite generation. Scanning electron microscopy observations on open fluid inclusion cavities permitted the crystallographic features of vacuoles to be determined. A characteristic feature of primary fluid inclusions in pyrite is a negative crystal habit, shaped mainly by {100}, {111} and {210}. This complicated polyhedral morphology is the reason for the observed opacity of some isometric primary inclusions. Secondary fluid inclusion morphology depends on the nature of the surface of the healed fracture. Recognition of the primary or secondary origin of fluid inclusions is enhanced by using crystallographically oriented sections. Microthermometric measurements of primary inclusions indicate that the second pyrite generation was deposited at maximum P-T conditions of 400 °C and 430 bar and from a fluid of low bulk salinity (3.5-4.6 wt%), possibly KCl-dominant. There are large ranges for homogenisation temperatures in secondary inclusions because of necking-down processes. Decrepitation features of some of pyrite-hosted inclusions and of all inclusions in associated quartz indicate reheating of the veins to 500-550 °C. The late cobalt-rich quartz-pyrite vein assemblage in the Radka deposit may be the shallow manifestation of deeper and genetically related porphyry copper mineralisation. This is a common observation of many intermediate- to high-sulfidation epithermal replacement-type ore bodies in this ore district and possibly the Cretaceous Banat-Srednogorie metallogenic belt in general.
Hyperspectral feature mapping classification based on mathematical morphology
NASA Astrophysics Data System (ADS)
Liu, Chang; Li, Junwei; Wang, Guangping; Wu, Jingli
2016-03-01
This paper proposed a hyperspectral feature mapping classification algorithm based on mathematical morphology. Without the priori information such as spectral library etc., the spectral and spatial information can be used to realize the hyperspectral feature mapping classification. The mathematical morphological erosion and dilation operations are performed respectively to extract endmembers. The spectral feature mapping algorithm is used to carry on hyperspectral image classification. The hyperspectral image collected by AVIRIS is applied to evaluate the proposed algorithm. The proposed algorithm is compared with minimum Euclidean distance mapping algorithm, minimum Mahalanobis distance mapping algorithm, SAM algorithm and binary encoding mapping algorithm. From the results of the experiments, it is illuminated that the proposed algorithm's performance is better than that of the other algorithms under the same condition and has higher classification accuracy.
A plate-driven model for enigmatic volcanic history of the Cascades-Yellowstone System
NASA Astrophysics Data System (ADS)
Szwaja, S.; Kincaid, C. R.; Druken, K. A.; MacDougall, J.
2013-12-01
The Cascades subduction system in the Pacific Northwest (USA) represents a complex tectonic setting, where rollback subduction of the Juan de Fuca plate beneath the North American plate, back-arc extension, and a possible mantle plume have been proposed to explain the complicated volcanic trends observed over the past 20 Ma. Plume and non-plume models have been developed to reconcile the voluminous Columbia River/Steens Flood Basalts (CSFB) (~20 Ma), the age progressive (15 Ma to present) Snake River Plain (SRP) that terminates at Yellowstone and the opposite, or westward trending High Lava Plains (HLP) volcanic track of eastern/central Oregon. We present results from laboratory experiments designed to test a plate-driven model for reproducing gross spatial-temporal characteristics of these three magmatic features. Models use a glucose fluid with temperature dependent viscosity in representing Earth's mantle and continuous rubber belts that kinematically reproduce subduction trends for the Cascades system. Experiments begin at 20 Ma with a volume of mantle residuum in the Cascades wedge that is elongated and restricted in the trench-parallel and trench-normal directions, respectively. The underlying assumption is that residuum was created in the wedge during an earlier plate steepening event that caused the flood basalts. Our models characterize dispersion patterns for the melt residuum material as it deforms within four-dimensional wedge circulation fields driven by rollback subduction (e.g. with a translational component of motion). Results show that residuum viscosity, relative to the ambient fluid, determines whether anomalous fluid can evolve to a morphology that matches the SRP/HLP tracks over ~15-20Ma. A weak residuum (e.g. retained partial melt) deforms over this time scale from the initial north-south oriented feature to an east-west trending morphology that is thin in both depth and north-south extent, material initially beneath CSFB is offset to the south, and is capable of producing opposite age progressions beneath the surface HLP/SRP track locations. The evolution of a high viscosity residuum in rollback-driven flow did not match the observed trends, as the feature deformed into an overly thick and wide morphology in the sub-HLP wedge compared to seismic data. Higher viscosity also produces stress coupling throughout the residuum, causing efficient entrainment from under the SRP towards the trench, leaving only ambient fluid beneath this track. In cases with stronger viscous coupling to the base of the overriding plate, the residuum is not able to deform into a morphology that is consistent with SRP/HLP tracks over the period 15 - 0 Ma. Models show only a limited range of conditions, where a low viscosity residuum is decoupled from the overriding plate, are capable of producing morphologies and offsets that roughly match observed spatial and temporal trends for primary features in the Pacific Northwest. Additional work is needed to understand the vertical heat/mass transfer processes that would enable deforming residuum to continually supply the bimodal magmatic output recorded over ~15Ma along the HLP and SRP tracks.
European early modern humans and the fate of the Neandertals
Trinkaus, Erik
2007-01-01
A consideration of the morphological aspects of the earliest modern humans in Europe (more than ≈33,000 B.P.) and the subsequent Gravettian human remains indicates that they possess an anatomical pattern congruent with the autapomorphic (derived) morphology of the earliest (Middle Paleolithic) African modern humans. However, they exhibit a variable suite of features that are either distinctive Neandertal traits and/or plesiomorphic (ancestral) aspects that had been lost among the African Middle Paleolithic modern humans. These features include aspects of neurocranial shape, basicranial external morphology, mandibular ramal and symphyseal form, dental morphology and size, and anteroposterior dental proportions, as well as aspects of the clavicles, scapulae, metacarpals, and appendicular proportions. The ubiquitous and variable presence of these morphological features in the European earlier modern human samples can only be parsimoniously explained as a product of modest levels of assimilation of Neandertals into early modern human populations as the latter dispersed across Europe. This interpretation is in agreement with current analyses of recent and past human molecular data. PMID:17452632
Real-Time X-Ray Microscopy of Al-Cu Eutectic Solidification
NASA Technical Reports Server (NTRS)
Kaukler, William F.; Curreri, Peter A.; Sen, Subhayu
1998-01-01
Recent improvements in the resolution of the X-ray Transmission Microscope (XTM) for Solidification Studies provide microstructure feature detectability down to 5 micrometers during solidification. This presentation will show the recent results from observations made in real-time of the solid-liquid interfacial morphologies of the Al-CuAI2 eutectic alloy. Lamellar dimensions and spacings, transitions of morphology caused by growth rate changes, and eutectic grain structures are open to measurements. A unique vantage point viewing the face of the interface isotherm is possible for the first time with the XTM due to its infinite depth of field. A video of the solid-liquid interfaces seen in-situ and in real-time will be shown.
Villarroya, Olga; Ballestín, Raúl; López-Hidalgo, Rosa; Mulet, Maria; Blasco-Ibáñez, José Miguel; Crespo, Carlos; Nacher, Juan; Gilabert-Juan, Javier; Varea, Emilio
2018-01-01
Down syndrome (DS) is the most common chromosomal aneuploidy. Although trisomy on chromosome 21 can display variable phenotypes, there is a common feature among all DS individuals: the presence of intellectual disability. This condition is partially attributed to abnormalities found in the hippocampus of individuals with DS and in the murine model for DS, Ts65Dn. To check if all hippocampal areas were equally affected in 4-5 month adult Ts65Dn mice, we analysed the morphology of dentate gyrus granule cells and cornu ammonis pyramidal neurons using Sholl method on Golgi-Cox impregnated neurons. Structural plasticity has been analysed using immunohistochemistry for plasticity molecules followed by densitometric analysis (Brain Derived Neurotrophic Factor (BDNF), Polysialylated form of the Neural Cell Adhesion Molecule (PSA-NCAM) and the Growth Associated Protein 43 (GAP43)). We observed an impairment in the dendritic arborisation of granule cells, but not in the pyramidal neurons in the Ts65Dn mice. When we analysed the expression of molecules related to structural plasticity in trisomic mouse hippocampus, we observed a reduction in the expression of BDNF and PSA-NCAM, and an increment in the expression of GAP43. These alterations were restricted to the regions related to dentate granule cells suggesting an interrelation. Therefore the impairment in dendritic arborisation and molecular plasticity is not a general feature of all Down syndrome principal neurons. Pharmacological manipulations of the levels of plasticity molecules could provide a way to restore granule cell morphology and function.
Effect of local void morphology on the reaction initiation mechanism in the case of pressed HMX
NASA Astrophysics Data System (ADS)
Roy, Sidhartha; Rai, Nirmal; Udaykumar, H. S.
2017-06-01
The microstructural characteristics of pressed HMX has a significant effect on its sensitivity under shock loading. The microstructure of pressed HMX contains voids of various orientation and aspect ratio. Subject to shock loading, these voids can collapse forming hotspots and initiate chemical reaction. This work shows how the ignition and growth of chemical reaction is dependent on the local microstructural features of the voids. Morphological quantities like size, aspect ratio and orientations are extracted from the real microstructural images of Class III and Class V pressed HMX. These morphological quantities are correlated with the ignition and growth rates of the chemical reaction. The dependency of the sensitivity of a given HMX sample on the local morphological features shows that these local features can create a mocroscale physical response.
Origin of Quantum Ring Formation During Droplet Epitaxy
NASA Astrophysics Data System (ADS)
Zhou, Z. Y.; Zheng, C. X.; Tang, W. X.; Tersoff, J.; Jesson, D. E.
2013-07-01
Droplet epitaxy of GaAs is studied in real time using in situ surface electron microscopy. The resulting movies motivate a theoretical model for quantum ring formation which can explain the origin of nanoscale features such as double rings observed under a variety of experimental conditions. Inner rings correspond to GaAs deposition at the droplet edge, while outer rings result from the reaction of Ga and As atoms diffusing along the surface. The observed variety of morphologies primarily reflects relative changes in the outer rings with temperature and As flux.
Periodic surface instabilities in stressed polymer solids
NASA Astrophysics Data System (ADS)
Tsukruk, Vladimir V.; Reneker, Darrell H.
1995-03-01
The surface morphology of isothermally grown polymer single crystals of polypropylene is observed by atomic force microscopy. The distinguishing features of the polymer single crystals studied are periodic undulations and transverse fractures (cracks) across the single crystal laths. Up to 20 wrinkles are observed near the edges of the cracks. The periodicity of these surface perturbations is 400+/-100 nm and the amplitude is 6+/-3 nm. The formation of the periodic modulations and transverse fractures is attributed to surface stress relief caused by the uniaxial thermal contraction of polymer solids.
Pediatric esophageal scintigraphy. Results of 200 studies
DOE Office of Scientific and Technical Information (OSTI.GOV)
Guillet, J.; Wynchank, S.; Basse-Cathalinat, B.
1983-09-01
Esophageal transit of a small volume of watery liquid has been observed scintigraphically in 200 studies performed on patients aged between 6 days and 16 years. Qualitative information concerning esophageal morphology and function in the various phases of deglutition, and scintigraphic features of achalasia, stenosis, and other pathologies are described. Measured esophageal transit time and its normal variation, its relevance to the diagnosis of esophagitis, and the monitoring of treatment are discussed. This technique observing distinct deglutitions has proven a useful diagnostic tool. Its advantages and limitations are discussed in comparison with other methods.
A Spatially Resolved Plerionic X-Ray Nebula around PSR B0540-69.
Gotthelf; Wang
2000-04-01
We present a high-resolution Chandra X-ray observation of PSR B0540-69, the Crab-like 50 ms pulsar in the Large Magellanic Cloud. We use phase-resolved imaging to decompose the extended X-ray emission, as expected of a synchrotron nebula, from the pointlike emission of the pulsar. The image of the pulsed X-ray emission shows a well-defined point-spread function of the observation, while the resolved nebula has a morphology and size remarkably similar to the Crab nebula, including evidence for a jetlike feature from PSR B0540-69. The patchy outer shell, which most likely represents the expanding blast wave of the supernova, is reminiscent of that seen in radio. Based on morphology, size, and energetics, there can be little doubt that SNR B0540-69 is an analogous system to the Crab but located in our neighboring galaxy.
Mărăşescu, Petre Costin; Turcu, Adina Andreea; Mercuţ, Veronica; Scrieciu, Monica; Mărgăritescu, Claudiu; Ionovici, Nina; Sălan, Alex Ioan; Mărăşescu, Felicia Ioana; Stan, Mihaela Cristina
2018-01-01
Tongue squamous carcinoma can be found in many forms, having a lot of risk factors, and whose morphological characteristics can be used as a prognostic. The purpose of this study was to histologically characterize a number of 54 patients diagnosed between 2012-2014, with tongue squamous carcinoma. Surgical resection specimens of tongue tumors were processed by paraffin inclusion technique. The diagnose samples were reevaluated according to the World Health Organization (WHO) criteria for head and neck tumors diagnosis, by screening the Hematoxylin-Eosin staining sections. The most common histopathological variety of tongue carcinoma observed in our cases was the non-keratinized form, the basaloid and sarcomatoid types of carcinoma being ranked on the last places. The study outlined the prevalence of non-keratinized forms of tongue squamous carcinoma and all types of tumoral invasion patterns have been observed in different percentages.
Micro and sub-micron surface structuring of AZ31 by laser re-melting and dimpling
NASA Astrophysics Data System (ADS)
Furlan, Valentina; Demir, Ali Gökhan; Previtali, Barbara
2015-12-01
In this work, the use of ns-pulsed fibre laser for surface structuring of AZ31 Mg alloy is investigated. Surface re-melting was employed to change surface morphology, especially in terms of surface roughness. Dimpling by percussion microdrilling was investigated to control the hole geometry.. With surface remelting mono-directional and homogeneous surfaces were obtained with Fl<500 J/cm2. Above 500 J/cm2 particle generation was observed, which induced sub-micron structure growth with nano-fibrous features. Moreover, surface roughness could be controlled below the initial value and much higher. With dimpling, transformation from gentle to strong ablation was observed at F0=10.3 J/cm2. XRD analysis was employed to link oxide growth to the surface morphology. Tensile tests were carried out to assess the damage on the mechanical properties after surface structuring.
Detection of Cardiac Abnormalities from Multilead ECG using Multiscale Phase Alternation Features.
Tripathy, R K; Dandapat, S
2016-06-01
The cardiac activities such as the depolarization and the relaxation of atria and ventricles are observed in electrocardiogram (ECG). The changes in the morphological features of ECG are the symptoms of particular heart pathology. It is a cumbersome task for medical experts to visually identify any subtle changes in the morphological features during 24 hours of ECG recording. Therefore, the automated analysis of ECG signal is a need for accurate detection of cardiac abnormalities. In this paper, a novel method for automated detection of cardiac abnormalities from multilead ECG is proposed. The method uses multiscale phase alternation (PA) features of multilead ECG and two classifiers, k-nearest neighbor (KNN) and fuzzy KNN for classification of bundle branch block (BBB), myocardial infarction (MI), heart muscle defect (HMD) and healthy control (HC). The dual tree complex wavelet transform (DTCWT) is used to decompose the ECG signal of each lead into complex wavelet coefficients at different scales. The phase of the complex wavelet coefficients is computed and the PA values at each wavelet scale are used as features for detection and classification of cardiac abnormalities. A publicly available multilead ECG database (PTB database) is used for testing of the proposed method. The experimental results show that, the proposed multiscale PA features and the fuzzy KNN classifier have better performance for detection of cardiac abnormalities with sensitivity values of 78.12 %, 80.90 % and 94.31 % for BBB, HMD and MI classes. The sensitivity value of proposed method for MI class is compared with the state-of-art techniques from multilead ECG.
Campbell, Julia; Sharma, Anu
2016-01-01
Measures of visual cortical development in children demonstrate high variability and inconsistency throughout the literature. This is partly due to the specificity of the visual system in processing certain features. It may then be advantageous to activate multiple cortical pathways in order to observe maturation of coinciding networks. Visual stimuli eliciting the percept of apparent motion and shape change is designed to simultaneously activate both dorsal and ventral visual streams. However, research has shown that such stimuli also elicit variable visual evoked potential (VEP) morphology in children. The aim of this study was to describe developmental changes in VEPs, including morphological patterns, and underlying visual cortical generators, elicited by apparent motion and shape change in school-aged children. Forty-one typically developing children underwent high-density EEG recordings in response to a continuously morphing, radially modulated, circle-star grating. VEPs were then compared across the age groups of 5-7, 8-10, and 11-15 years according to latency and amplitude. Current density reconstructions (CDR) were performed on VEP data in order to observe activated cortical regions. It was found that two distinct VEP morphological patterns occurred in each age group. However, there were no major developmental differences between the age groups according to each pattern. CDR further demonstrated consistent visual generators across age and pattern. These results describe two novel VEP morphological patterns in typically developing children, but with similar underlying cortical sources. The importance of these morphological patterns is discussed in terms of future studies and the investigation of a relationship to visual cognitive performance.
Campbell, Julia; Sharma, Anu
2016-01-01
Measures of visual cortical development in children demonstrate high variability and inconsistency throughout the literature. This is partly due to the specificity of the visual system in processing certain features. It may then be advantageous to activate multiple cortical pathways in order to observe maturation of coinciding networks. Visual stimuli eliciting the percept of apparent motion and shape change is designed to simultaneously activate both dorsal and ventral visual streams. However, research has shown that such stimuli also elicit variable visual evoked potential (VEP) morphology in children. The aim of this study was to describe developmental changes in VEPs, including morphological patterns, and underlying visual cortical generators, elicited by apparent motion and shape change in school-aged children. Forty-one typically developing children underwent high-density EEG recordings in response to a continuously morphing, radially modulated, circle-star grating. VEPs were then compared across the age groups of 5–7, 8–10, and 11–15 years according to latency and amplitude. Current density reconstructions (CDR) were performed on VEP data in order to observe activated cortical regions. It was found that two distinct VEP morphological patterns occurred in each age group. However, there were no major developmental differences between the age groups according to each pattern. CDR further demonstrated consistent visual generators across age and pattern. These results describe two novel VEP morphological patterns in typically developing children, but with similar underlying cortical sources. The importance of these morphological patterns is discussed in terms of future studies and the investigation of a relationship to visual cognitive performance. PMID:27445738
Rotation and Morphology of Comet 252P/LINEAR
NASA Astrophysics Data System (ADS)
Woodney, Laura; Schambeau, Charles A.; Fernandez, Yanga R.
2017-10-01
Comet 252P/LINEAR had an incredibly close approach early in 2016 - minimum distance 0.036 AU on March 21 - that allowed detailed investigation of its behavior. Analysis of observations of the morphology of 252P have resulted in several possible rotational periods. Knight and Schleicher found that repetition of features in narrowband imaging from April 2016 indicated a period of 7.35 +/- 0.05 hr [1]. HST broadband data obtained by Li et al. in March and April partially fit the 7.35 hr period, but found 5.5 hr was a better fit for the April 4 r’ band data [2]. Given this discrepancy, additional observations may shed light on the true rotation state, and we present here the pieces of the puzzle obtained by our group.We observed 252P with the Kitt Peak National Observatory WIYN 0.9 m telescope on 7 nights: May 2 - 5 and June 6,8,9, 2016 using a Harris R filter. An oscillating jet is clearly visible in our data. While there is insufficient phase coverage to determine a best fit period from our data alone, we will present how our observations of the morphology fit the two proposed periods.[1] Knight, M.M and D.G. Schleicher. AAS, DPS Meeting #48, id.207.02, 2016 [2] Li, J.-Y. et al. AAS, DPS Meeting #48, id. 206.03, 2016.
Automated Image Registration Using Morphological Region of Interest Feature Extraction
NASA Technical Reports Server (NTRS)
Plaza, Antonio; LeMoigne, Jacqueline; Netanyahu, Nathan S.
2005-01-01
With the recent explosion in the amount of remotely sensed imagery and the corresponding interest in temporal change detection and modeling, image registration has become increasingly important as a necessary first step in the integration of multi-temporal and multi-sensor data for applications such as the analysis of seasonal and annual global climate changes, as well as land use/cover changes. The task of image registration can be divided into two major components: (1) the extraction of control points or features from images; and (2) the search among the extracted features for the matching pairs that represent the same feature in the images to be matched. Manual control feature extraction can be subjective and extremely time consuming, and often results in few usable points. Automated feature extraction is a solution to this problem, where desired target features are invariant, and represent evenly distributed landmarks such as edges, corners and line intersections. In this paper, we develop a novel automated registration approach based on the following steps. First, a mathematical morphology (MM)-based method is used to obtain a scale-orientation morphological profile at each image pixel. Next, a spectral dissimilarity metric such as the spectral information divergence is applied for automated extraction of landmark chips, followed by an initial approximate matching. This initial condition is then refined using a hierarchical robust feature matching (RFM) procedure. Experimental results reveal that the proposed registration technique offers a robust solution in the presence of seasonal changes and other interfering factors. Keywords-Automated image registration, multi-temporal imagery, mathematical morphology, robust feature matching.
Large-scale Exploration of Neuronal Morphologies Using Deep Learning and Augmented Reality.
Li, Zhongyu; Butler, Erik; Li, Kang; Lu, Aidong; Ji, Shuiwang; Zhang, Shaoting
2018-02-12
Recently released large-scale neuron morphological data has greatly facilitated the research in neuroinformatics. However, the sheer volume and complexity of these data pose significant challenges for efficient and accurate neuron exploration. In this paper, we propose an effective retrieval framework to address these problems, based on frontier techniques of deep learning and binary coding. For the first time, we develop a deep learning based feature representation method for the neuron morphological data, where the 3D neurons are first projected into binary images and then learned features using an unsupervised deep neural network, i.e., stacked convolutional autoencoders (SCAEs). The deep features are subsequently fused with the hand-crafted features for more accurate representation. Considering the exhaustive search is usually very time-consuming in large-scale databases, we employ a novel binary coding method to compress feature vectors into short binary codes. Our framework is validated on a public data set including 58,000 neurons, showing promising retrieval precision and efficiency compared with state-of-the-art methods. In addition, we develop a novel neuron visualization program based on the techniques of augmented reality (AR), which can help users take a deep exploration of neuron morphologies in an interactive and immersive manner.
Possible sea sediments due to glaciofluvial activity in Elysium Planitia, Mars
NASA Astrophysics Data System (ADS)
Nussbaumer, J.
Observations of fluvial morphologies in southern Elysium Planitia strongly supports the hypothesis that water substantially affected this region during the relatively recent geologic past. As of yet, however, the extent of a standing body of water has been speculative. The observation of zig-zag features potentially analogous to those observed near the Wadden Sea on Earth [see 1] may help show in more detail the origin, activity, and fate of water in this region of Mars. These terrestrial analogs could constrain environmental scenarios concerning the formation of these features. We present a geomorphologic map of central Elysium Planitia, that aids in our interpretation of potentially site-specific depositional/erosional morphologies. Positive relief zig-zag features within the Medusae Fossae Formation (Themis Image V05875001) resemble similar structures on Earth observed at shorelines of flat regions. Glaciofluvial activity is indicated by linear features resembling straight glacial flutings, which could form aeolian yardangs subsequently. The flutings are associated with branches of inverted fluvial channels (Images Themis V05588002, MOC e1800307). Their excavated positive relief (height ~40 m) indicates, that the adjacent material was eroded by sublimation or aeolian activity. The channels possibly resemble ice marginal channels. A high resolution Digital Terrain Model of one of the channels suggests, that one channel is possibly running upslope. Fluvial processes could have operated at one location at one time, and glacial processes at another location at another time [2]. A glacial drainage system [see 3] is a possible terrestrial analog for one inverted fluvial channel on Mars (Themis Image V05875001). Flutings occur on the foreland of many glaciers and their length may provide important evidence for rapid advance over substantial distances. Flutings are the product of subglacial erosion and transport processes [4]. By assigning the different environmental conditions to their geographic and stratigraphic positions, we intend to develop a geologic history of the central Elysium region. Ackowledgements for helpful contributions: D. Burr, J. Skinner, R. Williams References: [1] Tomei, K. (2004), Scriptum Publishers, 312 pp. [2] Burr et al. (2006) LPS XXXVII, #1367. [3] Evans, D. (2005), Hodder Arnold, 544pp. [4] Sharp M. J. (1984) Journal of Glaciology 82-93.
Queiroz, Alexya Cunha de; Vallinoto, Marcelo; Sakai, Yoichi; Giarrizzo, Tommaso; Barros, Breno
2018-01-01
The mimetic juveniles of a number of carangid fish species resemble plant parts floating near the water surface, such as leaves, seeds and other plant debris. The present study is the first to verify the morphological similarities and ecomorphological relationships between three carangids (Oligoplites saurus, Oligoplites palometa and Trachinotus falcatus) and their associated plant models. Behavioral observations were conducted in the estuary of Curuçá River, in northeastern Pará (Brazil) between August 2015 and July 2016. Individual fishes and associated floating objects (models) were sampled for comparative analysis using both geometric and morphometric approaches. While the mimetic fish and their models retain their own distinct, intrinsic morphological features, a high degree of morphological similarity was found between each fish species and its model. The morphometric analyses revealed a general tendency of isometric development in all three fish species, probably related to their pelagic habitats, during all ontogenetic stages.
Hussain, Amara Noor; Zafar, Muhammad; Ahmad, Mushtaq; Khan, Raees; Yaseen, Ghulam; Khan, Muhammad Saleem; Nazir, Abdul; Khan, Amir Muhammad; Shaheen, Shabnum
2018-05-01
Palynological features as well as comparative foliar epidermal using light and scanning electron microscope (SEM) of 17 species (10genera) of Amaranthaceae have been studied for its taxonomic significance. Different foliar and palynological micro-morphological characters were examined to explain their value in resolving the difficulty in identification. All species were amphistomatic but stomata on abaxial surface were more abundant. Taxonomically significant epidermal character including stomata type, trichomes (unicellular, multicellular, and capitate) and epidermal cells shapes (polygonal and irregular) were also observed. Pollens of this family are Polypantoporate, pores large, spheroidal, mesoporous region is sparsely to scabrate, densely psilate, and spinulose. All these characters can be active at species level for identification purpose. This study indicates that at different taxonomic levels, LM and SEM pollen and epidermal morphology is explanatory and significant to identify species and genera. © 2018 Wiley Periodicals, Inc.
Park, Kyung-Min; Jung, Jae-Ho; Min, Gi-Sik; Kim, Sanghee
2017-07-01
A new soil ciliate, Pseudonotohymena antarctica n. g., n. sp., from King George Island, Antarctica, is described based on live observation, protargol impregnation, and its 18S rRNA gene. The new genus Pseudonotohymena is morphologically similar to the genus Notohymena Blatterer and Foissner in the following characteristics: 18 fronto-ventral-transverse cirri, a flexible body, undulating membranes, dorsomarginal kineties, and the number of cirri in the marginal rows. However, Pseudonotohymena differs from Notohymena particularly in the dorsal ciliature, that is, in possessing a nonfragmented dorsal kinety (vs. fragmented). In addition, the molecular phylogenetic relationship of the new species differs from that of Notohymena species. On the basis of the morphological features, the genetic data, and morphogenesis, we establish P. antarctica n. g., n. sp. In addition, the cyst morphology of this species is described. © 2016 The Author(s) Journal of Eukaryotic Microbiology © 2016 International Society of Protistologists.
NASA Astrophysics Data System (ADS)
Sugime, Yasuhiro; Ogawa, Kota; Watanabe, Dai; Shimoji, Hiroyuki; Koshikawa, Shigeyuki; Miura, Toru
2015-12-01
In termites, the soldier caste possesses morphological features suitable for colony defence, despite some exceptions. Soldiers are differentiated via two moultings through a presoldier stage with dramatic morphogenesis. While a number of morphological modifications are known to occur during the presoldier moult, growth and morphogenesis seem to continue even after the moult. The present study, using the damp-wood termite Hodotermopsis sjostedti, carried out morphological and histological investigations on the developmental processes during the presoldier stage that is artificially induced by the application of a juvenile hormone analogue. Measurements of five body parameters indicated that head length significantly increased during the 14-day period after the presoldier moult, while it did not increase subsequently to the stationary moult (pseudergate moult as control). Histological observations also showed that the cuticular development played a role in the presoldier head elongation, suggesting that the soft and flexible presoldier cuticle contributed to the soldier morphogenesis in termites.
Heckmann, Richard A; Amin, Omar M; Halajian, Ali; El-Naggar, Atif M
2013-02-01
The morphology of Nephridiacanthus major (Bremser 1811 in Westrumb 1821) Golvan, 1962 collected from the long-eared hedgehog Hemiechinus auritus (Gmelin 1770) and the Eastern European hedgehog Erinaceus concolor Martin, 1838 (Erinaceidae) is described using SEM for the first time. This acanthocephalan was previously described from hedgehogs in Europe, Asia, and Africa. Measurements of specimens from Iran, Bulgaria, Germany, Central Asia, Morocco, and Egypt show considerable variations in the size of the trunk, proboscis, proboscis hooks and receptacle, and eggs. The SEM studies add new perspectives to its morphology. Features observed for the first time include the near terminal position and shape of the female gonopore and orifice, among others. Histopathological studies for this species are reported for the first time. Tissue sections show extensive damage near the proboscis with hemorrhaging and formation of collagenous connective tissue, compression of the intestinal mucosa, obstruction of intestinal lumen, and extensive necrosis of host epithelial tissue.
Quantification of mammalian tumor cell state plasticity with digital holographic cytometry
NASA Astrophysics Data System (ADS)
Hejna, Miroslav; Jorapur, Aparna; Zhang, Yuntian; Song, Jun S.; Judson, Robert L.
2018-02-01
Individual cells within isogenic tumor populations can exhibit distinct cellular morphologies, behaviors, and molecular profiles. Cell state plasticity refers to the propensity of a cell to transition between these different morphologies and behaviors. Elevation of cell state plasticity is thought to contribute to critical stages in tumor evolution, including metastatic dissemination and acquisition of therapeutic resistance. However, methods for quantifying general plasticity in mammalian cells remain limited. Working with a HoloMonitor M4 digital holographic cytometry platform, we have established a machine learning-based pipeline for high accuracy and label-free classification of adherent cells. We use twenty-six morphological and optical density-derived features for label-free identification of cell state in heterogeneous cultures. The system is housed completely within a mammalian cell incubator, permitting the monitoring of changes in cell state over time. Here we present an application of our approach for studying cell state plasticity. Human melanoma cell lines of known metastatic potential were monitored in standard growth conditions. The rate of feature change was quantified for each individual cell in the populations. We observed that cells of higher metastatic potential exhibited more rapid fluctuation of cell state in homeostatic conditions. The approach we demonstrate will be advantageous for further investigations into the factors that influence cell state plasticity.
NASA Astrophysics Data System (ADS)
Chen, Jianli; Wang, Guangjian; Qi, Chengjun; Zhang, Ying; Zhang, Song; Xu, Yongkuan; Hao, Jianmin; Lai, Zhanping; Zheng, Lili
2018-02-01
This paper presents a recent study on the morphology variation on the lateral faces of a HPHT diamond seed by MPCVD method. Raman spectroscopy and SEM were used to display the morphological and structural evolution of the grown diamond. It has been observed that different types of carbon allotropes were deposited at different heights of the substrate. At the bottom of the substrate, the feature of the lateral face was dominated by vertically aligned graphite nanoplatelets. An increment of sp3 and sp2 hybridized carbons was found to take over at the region of approximately 100 μm above from the bottom followed by the increasing-size diamond grains. The high quality single crystalline diamond was formed at the top of the lateral face. We proposed that the temperature gradient around the substrate is responsible for variable features on the substrate lateral face. By optimizing the growth temperature, we have obtained an enlarged area of the lateral face with high quality single crystalline diamond. This work will provide both sp2 on sp3 carbon materials for the development of electrochemical sensors and electrodes, and a foundation for the diamond lateral face growth with high quality and high purity.
Final report for the DOE Early Career Award #DE-SC0003912
DOE Office of Scientific and Technical Information (OSTI.GOV)
Jayaraman, Arthi
This DoE supported early career project was aimed at developing computational models, theory and simulation methods that would be then be used to predict assembly and morphology in polymer nanocomposites. In particular, the focus was on composites in active layers of devices, containing conducting polymers that act as electron donors and nanoscale additives that act as electron acceptors. During the course this work, we developed the first of its kind molecular models to represent conducting polymers enabling simulations at the experimentally relevant length and time scales. By comparison with experimentally observed morphologies we validated these models. Furthermore, using these modelsmore » and molecular dynamics simulations on graphical processing units (GPUs) we predicted the molecular level design features in polymers and additive that lead to morphologies with optimal features for charge carrier behavior in solar cells. Additionally, we also predicted computationally new design rules for better dispersion of additives in polymers that have been confirmed through experiments. Achieving dispersion in polymer nanocomposites is valuable to achieve controlled macroscopic properties of the composite. The results obtained during the course of this DOE funded project enables optimal design of higher efficiency organic electronic and photovoltaic devices and improve every day life with engineering of these higher efficiency devices.« less
NASA Astrophysics Data System (ADS)
Krappe, Sebastian; Benz, Michaela; Wittenberg, Thomas; Haferlach, Torsten; Münzenmayer, Christian
2015-03-01
The morphological analysis of bone marrow smears is fundamental for the diagnosis of leukemia. Currently, the counting and classification of the different types of bone marrow cells is done manually with the use of bright field microscope. This is a time consuming, partly subjective and tedious process. Furthermore, repeated examinations of a slide yield intra- and inter-observer variances. For this reason an automation of morphological bone marrow analysis is pursued. This analysis comprises several steps: image acquisition and smear detection, cell localization and segmentation, feature extraction and cell classification. The automated classification of bone marrow cells is depending on the automated cell segmentation and the choice of adequate features extracted from different parts of the cell. In this work we focus on the evaluation of support vector machines (SVMs) and random forests (RFs) for the differentiation of bone marrow cells in 16 different classes, including immature and abnormal cell classes. Data sets of different segmentation quality are used to test the two approaches. Automated solutions for the morphological analysis for bone marrow smears could use such a classifier to pre-classify bone marrow cells and thereby shortening the examination duration.
High-resolution mapping of the 1998 lava flows at Axial Seamount
NASA Astrophysics Data System (ADS)
Chadwick, B.; Clague, D. A.; Embley, R. W.; Caress, D. W.; Paduan, J. B.; Sasnett, P.
2011-12-01
Axial Seamount (an active hotspot volcano on the Juan de Fuca Ridge) last erupted in 1998 and produced two lava flows (a "northern" and a "southern" flow) along the upper south rift zone separated by a distance of 4 km. Geologic mapping of the 1998 lava flows has been carried out with a combination of visual observations from multiple submersible dives since 1998, and with high-resolution bathymetry, most recently collected with the MBARI mapping AUV (the D. Allan B.) since 2007. The new mapping results revise and update the previous preliminary flow outlines, areas, and volumes. The high-resolution bathymetry (1-m grid cell size) allows eruptive fissures fine-scale morphologic features to be resolved with new and remarkable clarity. The morphology of both lava flows can be interpreted as a consequence of a specific sequence of events during their emplacement. The northern sheet flow is long (4.6 km) and narrow (500 m), and erupted in the SE part of Axial caldera, where it temporarily ponded and inflated on relatively flat terrain before draining out southward toward steeper slopes. The inflation and drain-out of this sheet flow by ~ 3.5 m over 2.5 hours was previously documented by a monitoring instrument that was caught in the lava flow. Our geologic mapping shows that the morphology of the northern sheet flow varies along its length primarily due to gradients in the underlying slope and processes active during flow emplacement. The original morphology of the sheet flow where it ponded is lobate, with pillows near the margins, whereas the central axis of drain-out and collapse is floored with lineated, ropy, and jumbled lava morphologies. The southern lava flow, in contrast, is mostly pillow lava where it cascaded down the steep slope on the east flank of the south rift zone, but also has a major area of collapse where lava ponded temporarily near the rift axis. These results show that submarine lava flows have more subsurface hydraulic connectivity than has previously been supposed. For example, a common morphologic feature at the downslope ends of the 1998 lava flows (and on many older flows at Axial) is large lobes covered with pillows that are 200-500-m in diameter, 10-20-m thick, and are capped with centered, dendritic collapse areas 5-10 m deep. These large lobes show clear evidence of inflation and drain-out, and are often arranged in a shingle-like fashion, implying progressive emplacement at decreasing distance from the eruptive vent with time. Such features are impossible to discern from visual observations alone and are only revealed by high-resolution bathymetry.
2012-01-01
Background The biphasic life cycle with pelagic larva and benthic adult stages is widely observed in the animal kingdom, including the Porifera (sponges), which are the earliest branching metazoans. The demosponge, Amphimedon queenslandica, undergoes metamorphosis from a free-swimming larva into a sessile adult that bears no morphological resemblance to other animals. While the genome of A. queenslandica contains an extensive repertoire of genes very similar to that of complex bilaterians, it is as yet unclear how this is drawn upon to coordinate changing morphological features and ecological demands throughout the sponge life cycle. Results To identify genome-wide events that accompany the pelagobenthic transition in A. queenslandica, we compared global gene expression profiles at four key developmental stages by sequencing the poly(A) transcriptome using SOLiD technology. Large-scale changes in transcription were observed as sponge larvae settled on the benthos and began metamorphosis. Although previous systematics suggest that the only clear homology between Porifera and other animals is in the embryonic and larval stages, we observed extensive use of genes involved in metazoan-associated cellular processes throughout the sponge life cycle. Sponge-specific transcripts are not over-represented in the morphologically distinct adult; rather, many genes that encode typical metazoan features, such as cell adhesion and immunity, are upregulated. Our analysis further revealed gene families with candidate roles in competence, settlement, and metamorphosis in the sponge, including transcription factors, G-protein coupled receptors and other signaling molecules. Conclusions This first genome-wide study of the developmental transcriptome in an early branching metazoan highlights major transcriptional events that accompany the pelagobenthic transition and point to a network of regulatory mechanisms that coordinate changes in morphology with shifting environmental demands. Metazoan developmental and structural gene orthologs are well-integrated into the expression profiles at every stage of sponge development, including the adult. The utilization of genes involved in metazoan-associated processes throughout sponge development emphasizes the potential of the genome of the last common ancestor of animals to generate phenotypic complexity. PMID:22646746
Possibility of testing the light dark matter hypothesis with the alpha magnetic spectrometer.
Hooper, Dan; Xue, Wei
2013-01-25
The spectrum and morphology of gamma rays from the Galactic center and the spectrum of synchrotron emission observed from the Milky Way's radio filaments have each been interpreted as possible signals of ∼ 7-10 GeV dark matter particles annihilating in the inner Galaxy. In dark matter models capable of producing these signals, the annihilations should also generate significant fluxes of ∼ 7-10 GeV positrons which can lead to a distinctive bumplike feature in a local cosmic ray positron spectrum. In this Letter, we show that while such a feature would be difficult to detect with PAMELA, it would likely be identifiable by the currently operating Alpha Magnetic Spectrometer experiment. As no known astrophysical (i.e., nondark matter) sources or mechanisms are likely to produce such a sharp feature, the observation of a positron bump at around 7-10 GeV would significantly strengthen the case for a dark matter interpretation of the reported gamma-ray and radio anomalies.
Lin, Sabrina C.; Bays, Brett C.; Omaiye, Esther; Bhanu, Bir; Talbot, Prue
2016-01-01
There is a foundational need for quality control tools in stem cell laboratories engaged in basic research, regenerative therapies, and toxicological studies. These tools require automated methods for evaluating cell processes and quality during in vitro passaging, expansion, maintenance, and differentiation. In this paper, an unbiased, automated high-content profiling toolkit, StemCellQC, is presented that non-invasively extracts information on cell quality and cellular processes from time-lapse phase-contrast videos. Twenty four (24) morphological and dynamic features were analyzed in healthy, unhealthy, and dying human embryonic stem cell (hESC) colonies to identify those features that were affected in each group. Multiple features differed in the healthy versus unhealthy/dying groups, and these features were linked to growth, motility, and death. Biomarkers were discovered that predicted cell processes before they were detectable by manual observation. StemCellQC distinguished healthy and unhealthy/dying hESC colonies with 96% accuracy by non-invasively measuring and tracking dynamic and morphological features over 48 hours. Changes in cellular processes can be monitored by StemCellQC and predictions can be made about the quality of pluripotent stem cell colonies. This toolkit reduced the time and resources required to track multiple pluripotent stem cell colonies and eliminated handling errors and false classifications due to human bias. StemCellQC provided both user-specified and classifier-determined analysis in cases where the affected features are not intuitive or anticipated. Video analysis algorithms allowed assessment of biological phenomena using automatic detection analysis, which can aid facilities where maintaining stem cell quality and/or monitoring changes in cellular processes are essential. In the future StemCellQC can be expanded to include other features, cell types, treatments, and differentiating cells. PMID:26848582
Zahedi, Atena; On, Vincent; Lin, Sabrina C; Bays, Brett C; Omaiye, Esther; Bhanu, Bir; Talbot, Prue
2016-01-01
There is a foundational need for quality control tools in stem cell laboratories engaged in basic research, regenerative therapies, and toxicological studies. These tools require automated methods for evaluating cell processes and quality during in vitro passaging, expansion, maintenance, and differentiation. In this paper, an unbiased, automated high-content profiling toolkit, StemCellQC, is presented that non-invasively extracts information on cell quality and cellular processes from time-lapse phase-contrast videos. Twenty four (24) morphological and dynamic features were analyzed in healthy, unhealthy, and dying human embryonic stem cell (hESC) colonies to identify those features that were affected in each group. Multiple features differed in the healthy versus unhealthy/dying groups, and these features were linked to growth, motility, and death. Biomarkers were discovered that predicted cell processes before they were detectable by manual observation. StemCellQC distinguished healthy and unhealthy/dying hESC colonies with 96% accuracy by non-invasively measuring and tracking dynamic and morphological features over 48 hours. Changes in cellular processes can be monitored by StemCellQC and predictions can be made about the quality of pluripotent stem cell colonies. This toolkit reduced the time and resources required to track multiple pluripotent stem cell colonies and eliminated handling errors and false classifications due to human bias. StemCellQC provided both user-specified and classifier-determined analysis in cases where the affected features are not intuitive or anticipated. Video analysis algorithms allowed assessment of biological phenomena using automatic detection analysis, which can aid facilities where maintaining stem cell quality and/or monitoring changes in cellular processes are essential. In the future StemCellQC can be expanded to include other features, cell types, treatments, and differentiating cells.
The molecular basis of breast cancer pathological phenotypes.
Heng, Yujing J; Lester, Susan C; Tse, Gary Mk; Factor, Rachel E; Allison, Kimberly H; Collins, Laura C; Chen, Yunn-Yi; Jensen, Kristin C; Johnson, Nicole B; Jeong, Jong Cheol; Punjabi, Rahi; Shin, Sandra J; Singh, Kamaljeet; Krings, Gregor; Eberhard, David A; Tan, Puay Hoon; Korski, Konstanty; Waldman, Frederic M; Gutman, David A; Sanders, Melinda; Reis-Filho, Jorge S; Flanagan, Sydney R; Gendoo, Deena Ma; Chen, Gregory M; Haibe-Kains, Benjamin; Ciriello, Giovanni; Hoadley, Katherine A; Perou, Charles M; Beck, Andrew H
2017-02-01
The histopathological evaluation of morphological features in breast tumours provides prognostic information to guide therapy. Adjunct molecular analyses provide further diagnostic, prognostic and predictive information. However, there is limited knowledge of the molecular basis of morphological phenotypes in invasive breast cancer. This study integrated genomic, transcriptomic and protein data to provide a comprehensive molecular profiling of morphological features in breast cancer. Fifteen pathologists assessed 850 invasive breast cancer cases from The Cancer Genome Atlas (TCGA). Morphological features were significantly associated with genomic alteration, DNA methylation subtype, PAM50 and microRNA subtypes, proliferation scores, gene expression and/or reverse-phase protein assay subtype. Marked nuclear pleomorphism, necrosis, inflammation and a high mitotic count were associated with the basal-like subtype, and had a similar molecular basis. Omics-based signatures were constructed to predict morphological features. The association of morphology transcriptome signatures with overall survival in oestrogen receptor (ER)-positive and ER-negative breast cancer was first assessed by use of the Molecular Taxonomy of Breast Cancer International Consortium (METABRIC) dataset; signatures that remained prognostic in the METABRIC multivariate analysis were further evaluated in five additional datasets. The transcriptomic signature of poorly differentiated epithelial tubules was prognostic in ER-positive breast cancer. No signature was prognostic in ER-negative breast cancer. This study provided new insights into the molecular basis of breast cancer morphological phenotypes. The integration of morphological with molecular data has the potential to refine breast cancer classification, predict response to therapy, enhance our understanding of breast cancer biology, and improve clinical management. This work is publicly accessible at www.dx.ai/tcga_breast. Copyright © 2016 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd. Copyright © 2016 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Assugeni, Camila de O; Magalhães, Tatiana; Bolaños, Juan A; Tudge, Christopher C; Mantelatto, Fernando L; Zara, Fernando J
2017-12-01
Recent studies based on morphological and molecular data provide a new perspective concerning taxonomic aspects of the brachyuran family Mithracidae. These studies proposed a series of nominal changes and indicated that the family is actually represented by a different number and representatives of genera than previously thought. Here, we provide a comparative description of the ultrastructure of spermatozoa and spermatophores of some species of Mithracidae in a phylogenetic context. The ultrastructure of the spermatozoa and spermatophore was observed by scanning and transmission electron microscopy. The most informative morphological characters analysed were thickness of the operculum, shape of the perforatorial chamber and shape and thickness of the inner acrosomal zone. As a framework, we used a topology based on a phylogenetic analysis using mitochondrial data obtained here and from previous studies. Our results indicate that closely related species share a series of morphological characteristics of the spermatozoa. A thick operculum, for example, is a feature observed in species of the genera Amphithrax, Teleophrys, and Omalacantha in contrast to the slender operculum observed in Mithraculus and Mithrax. Amphithrax and Teleophrys have a rhomboid perforatorial chamber, while Mithraculus, Mithrax, and Omalacantha show a wider, deltoid morphology. Furthermore, our results are in agreement with recently proposed taxonomic changes including the separation of the genera Mithrax (previously Damithrax), Amphithrax (previously Mithrax) and Mithraculus, and the synonymy of Mithrax caribbaeus with Mithrax hispidus. Overall, the spermiotaxonomy of these species of Mithracidae represent a novel set of data that corroborates the most recent taxonomic revision of the family and can be used in future taxonomic and phylogenetic studies within this family. © 2017 Wiley Periodicals, Inc.
Bizheva, Kostadinka; Tan, Bingyao; MacLellan, Benjamin; Hosseinaee, Zohreh; Mason, Erik; Hileeto, Denise; Sorbara, Luigina
2017-01-01
A research-grade OCT system was used to image in-vivo and without contact with the tissue, the cellular structure and microvasculature of the healthy human corneo-scleral limbus. The OCT system provided 0.95 µm axial and 4 µm (2 µm) lateral resolution in biological tissue depending on the magnification of the imaging objective. Cross-sectional OCT images acquired tangentially from the inferior limbus showed reflective, loop-like features that correspond to the fibrous folds of the palisades of Vogt (POV). The high OCT resolution allowed for visualization of individual cells inside the limbal crypts, capillaries extending from the inside of the POV’s fibrous folds and connecting to a lateral grid of micro-vessels located in the connective tissue directly below the POV, as well as reflections from individual red blood cells inside the capillaries. Difference in the reflective properties of the POV was observed among subjects of various pigmentation levels of the POV. Morphological features observed in the high resolution OCT images correlated well with histology. The ability to visualize the limbal morphology and microvasculature in-vivo at cellular level can aid the diagnostics and treatment of limbal stem cell dysfunction and dystrophies. PMID:28966853
NASA Astrophysics Data System (ADS)
Tripathi, Saroj R.; Miyata, Eisuke; Ishai, Paul Ben; Kawase, Kodo
2015-03-01
It is crucial to understand the various biological effects induced by terahertz (THz) electromagnetic waves with the rapid development of electronic and photonic devices operating in the THz frequency region. The presence of sweat glands plays an important role in THz wave interactions with human skin. We investigated the morphological features of sweat ducts using optical coherence tomography (OCT) to further understand such phenomena. We observed remarkable features of the ducts, such as their clear helical structure. The intersubject and intrasubject variations in the diameter of sweat ducts were considerably smaller than the variations in other structural parameters, such as length and number of turns. Based on the sweat duct dimensions and THz dielectric properties of skin measured using terahertz time-domain spectroscopy (THz-TDS), we calculated the resonating frequency of the sweat duct under the assumption of it functioning as a helical antenna. Here, we show that the resonance frequency in the axial mode of operation lies in the THz wave region with a centre frequency of 0.44 +/- 0.07 THz. We expect that these findings will further our understanding of the various health consequences of the interaction of THz waves with human beings.
Content-based cell pathology image retrieval by combining different features
NASA Astrophysics Data System (ADS)
Zhou, Guangquan; Jiang, Lu; Luo, Limin; Bao, Xudong; Shu, Huazhong
2004-04-01
Content Based Color Cell Pathology Image Retrieval is one of the newest computer image processing applications in medicine. Recently, some algorithms have been developed to achieve this goal. Because of the particularity of cell pathology images, the result of the image retrieval based on single characteristic is not satisfactory. A new method for pathology image retrieval by combining color, texture and morphologic features to search cell images is proposed. Firstly, nucleus regions of leukocytes in images are automatically segmented by K-mean clustering method. Then single leukocyte region is detected by utilizing thresholding algorithm segmentation and mathematics morphology. The features that include color, texture and morphologic features are extracted from single leukocyte to represent main attribute in the search query. The features are then normalized because the numerical value range and physical meaning of extracted features are different. Finally, the relevance feedback system is introduced. So that the system can automatically adjust the weights of different features and improve the results of retrieval system according to the feedback information. Retrieval results using the proposed method fit closely with human perception and are better than those obtained with the methods based on single feature.
Sherratt, Emma; Serb, Jeanne M; Adams, Dean C
2017-12-08
Rates of morphological evolution vary across different taxonomic groups, and this has been proposed as one of the main drivers for the great diversity of organisms on Earth. Of the extrinsic factors pertaining to this variation, ecological hypotheses feature prominently in observed differences in phenotypic evolutionary rates across lineages. But complex organisms are inherently modular, comprising distinct body parts that can be differentially affected by external selective pressures. Thus, the evolution of trait covariation and integration in modular systems may also play a prominent role in shaping patterns of phenotypic diversity. Here we investigate the role ecological diversity plays in morphological integration, and the tempo of shell shape evolution and of directional asymmetry in bivalved scallops. Overall, the shape of both valves and the magnitude of asymmetry of the whole shell (difference in shape between valves) are traits that are evolving fast in ecomorphs under strong selective pressures (gliders, recessers and nestling), compared to low rates observed in other ecomorphs (byssal-attaching, free-living and cementing). Given that different parts of an organism can be under different selective pressures from the environment, we also examined the degree of evolutionary integration between the valves as it relates to ecological shifts. We find that evolutionary morphological integration is consistent and surprisingly high across species, indicating that while the left and right valves of a scallop shell are diversifying in accordance with ecomorphology, they are doing so in a concerted fashion. Our study on scallops adds another strong piece of evidence that ecological shifts play an important role in the tempo and mode of morphological evolution. Strong selective pressures from the environment, inferred from the repeated evolution of distinct ecomorphs, have influenced the rate of morphological evolution in valve shape and the magnitude of asymmetry between valves. Our observation that morphological integration of the valves making up the shell is consistently strong suggests tight developmental pathways are responsible for the concerted evolution of these structures while environmental pressures are driving whole shell shape. Finally, our study shows that directional asymmetry in shell shape among species is an important aspect of scallop macroevolution.
[Sinonasal fungal infections are not exclusively due to mucorales and Aspergillus!].
Tauziède-Espariat, Arnault; Wassef, Michel; Adle-Biassette, Homa; Alanio, Alexandre; Bretagne, Stéphane; Lanternier, Fanny; Boui, Mohammed; Bouchaud, Olivier; Vironneau, Pierre; Kania, Romain; Jouvion, Grégory; Chrétien, Fabrice; Classe, Marion
2016-08-01
Rhino-sinusal infections are serious diseases and possibly lethal. When they are invasive, we easily discuss apergilloses and mucormycoses. The confirmation of the diagnosis of mucormycosis need an extensive surgery for precise histopathological and mycological evaluation. The pathologist may be faced to other rare mycoses such as phaeohyphomycoses, which present different morphological features than mucormycoses and Aspergillus. Once the diagnosis is established, an appropriate antifungal treatment is quickly started. The aim of our work is to report two observations of phaeohyphomycoses, to describe their histopathological features, to discuss complementary diagnostic methods and to present the main differential diagnoses. Copyright © 2016 Elsevier Masson SAS. All rights reserved.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Dai, Jing; Quan, Sheng-Wen; Zhang, Bao-Cheng
The RF performance of a 1.3 GHz 9-cell superconducting niobium cavity was evaluated at cryogenic temperatures following surface processing by using the standard ILC-style recipe. The cavity is a TESLA-style 9-cell superconducting niobium cavity, with complete end group components including a higher order mode coupler, built in China for practical applications. An accelerating gradient of 28.6 MV/m was achieved at an unloaded quality factor of 4 x 10{sup 9}. The morphological property of mechanical features on the RF surface of this cavity was characterized through optical inspection. Correlation between the observed mechanical features and the RF performance of the cavitymore » is attempted.« less
Morphology captures diet and locomotor types in rodents.
Verde Arregoitia, Luis D; Fisher, Diana O; Schweizer, Manuel
2017-01-01
To understand the functional meaning of morphological features, we need to relate what we know about morphology and ecology in a meaningful, quantitative framework. Closely related species usually share more phenotypic features than distant ones, but close relatives do not necessarily have the same ecologies. Rodents are the most diverse group of living mammals, with impressive ecomorphological diversification. We used museum collections and ecological literature to gather data on morphology, diet and locomotion for 208 species of rodents from different bioregions to investigate how morphological similarity and phylogenetic relatedness are associated with ecology. After considering differences in body size and shared evolutionary history, we find that unrelated species with similar ecologies can be characterized by a well-defined suite of morphological features. Our results validate the hypothesized ecological relevance of the chosen traits. These cranial, dental and external (e.g. ears) characters predicted diet and locomotion and showed consistent differences among species with different feeding and substrate use strategies. We conclude that when ecological characters do not show strong phylogenetic patterns, we cannot simply assume that close relatives are ecologically similar. Museum specimens are valuable records of species' phenotypes and with the characters proposed here, morphology can reflect functional similarity, an important component of community ecology and macroevolution.
Turning maneuvers in sharks: Predicting body curvature from axial morphology.
Porter, Marianne E; Roque, Cassandra M; Long, John H
2009-08-01
Given the diversity of vertebral morphologies among fishes, it is tempting to propose causal links between axial morphology and body curvature. We propose that shape and size of the vertebrae, intervertebral joints, and the body will more accurately predict differences in body curvature during swimming rather than a single meristic such as total vertebral number alone. We examined the correlation between morphological features and maximum body curvature seen during routine turns in five species of shark: Triakis semifasciata, Heterodontus francisci, Chiloscyllium plagiosum, Chiloscyllium punctatum, and Hemiscyllium ocellatum. We quantified overall body curvature using three different metrics. From a separate group of size-matched individuals, we measured 16 morphological features from precaudal vertebrae and the body. As predicted, a larger pool of morphological features yielded a more robust prediction of maximal body curvature than vertebral number alone. Stepwise linear regression showed that up to 11 features were significant predictors of the three measures of body curvature, yielding highly significant multiple regressions with r(2) values of 0.523, 0.537, and 0.584. The second moment of area of the centrum was always the best predictor, followed by either centrum length or transverse height. Ranking as the fifth most important variable in three different models, the body's total length, fineness ratio, and width were the most important non-vertebral morphologies. Without considering the effects of muscle activity, these correlations suggest a dominant role for the vertebral column in providing the passive mechanical properties of the body that control, in part, body curvature during swimming. (c) 2009 Wiley-Liss, Inc.
NASA Astrophysics Data System (ADS)
Ueda, Sayako; Nakayama, Tomoki; Taketani, Fumikazu; Adachi, Kouji; Matsuki, Atsushi; Iwamoto, Yoko; Sadanaga, Yasuhiro; Matsumi, Yutaka
2016-03-01
The coating of black carbon (BC) with inorganic salts and organic compounds can enhance the magnitude of light absorption by BC. To elucidate the enhancement of light absorption of aged BC particles and its relation to the mixing state and morphology of individual particles, we conducted observations of particles at an Asian outflow site in Noto Peninsula, Japan, in the spring of 2013. Absorption and scattering coefficients at 405, 532, and 781 nm and mass concentrations/mixing states of refractory BC in PM2.5 were measured using a three-wavelength photoacoustic soot spectrometer and a single-particle soot photometer (SP2), respectively, after passage through a thermodenuder (TD) maintained at 300 or 400 °C or a bypass line maintained at room temperature (25 °C). The average enhancement factor of BC light absorption due to coating was estimated by comparing absorption coefficients at 781 nm for particles that with and without passing through the TD at 300 °C and was found to be 1.22. The largest enhancements (> 1.30) were observed under high absorption coefficient periods when the air mass was long-range transported from urban areas in China. Aerosol samples were also analyzed using a transmission electron microscope (TEM) equipped with an energy dispersive X-ray analyzer. The morphological features and mixing states of soot-containing particles of four samples collected during the high absorption events were analyzed by comparing microphotographs before and after the evaporation of beam-sensitive materials by irradiation with a high-density electron beam. The majority of the soot in all samples was found as mixed particles with sulfate-containing spherules or as clusters of such spherules. For samples showing high enhancement (> 1.30) of BC light absorption, the TEM showed that the internally mixed soot-containing particles tended to have a more spherical shape and to be thickly coated. The SP2 measurements also suggested that the proportion of thickly coated soot was greater. Thus, the observed enhancement of BC light absorption was found to differ according to the mixing states and morphology of soot-containing particles. The enhancement of BC light absorption in our in situ measurements and its relation with individual features of soot-containing particles will be useful to evaluate direct radiative forcing in the downwind areas of large emission sources of BC.
NASA Astrophysics Data System (ADS)
Ueda, S.; Nakayama, T.; Taketani, F.; Adachi, K.; Matsuki, A.; Iwamoto, Y.; Sadanaga, Y.; Matsumi, Y.
2015-09-01
The coating of black carbon (BC) with inorganic salts and organic compounds can enhance the magnitude of light absorption by BC. To elucidate the enhancement of light absorption of aged BC particles and its relation to the mixing state and morphology of individual particles, we conducted observations of particles at an Asian outflow site in Noto Peninsula, Japan, in the spring of 2013. Absorption and scattering coefficients at 405, 532, and 781 nm and mass concentrations/mixing states of refractory-BC in PM2.5 were measured using a three-wavelength photoacoustic soot spectrometer and a single-particle soot photometer (SP2), respectively, after passage through a heater maintained at 300 or 400 °C or a bypass line maintained at room temperature (25 °C). The average enhancement of BC light absorption due to coating was estimated by comparing absorption coefficients at 781 nm for particles that with and without passing through the heater and was found to be 22-23 %. The largest enhancements (> 30 %) were observed under high absorption coefficient conditions when the air mass was long-range transported from urban areas in China. Aerosol samples were also analyzed using a transmission electron microscope (TEM) equipped with an energy dispersive X-ray analyzer. The morphological features and mixing states of soot-containing particles of four samples collected during the high absorption coefficient events were analyzed by comparing microphotographs before and after the evaporation of beam-sensitive materials by irradiation with a high density electron beam. The majority of the soot in all samples was found as mixed particles with spherical sulfate or as clusters of sulfate spherules. For samples showing high enhancement (> 30 %) of BC light absorption, TEM showed that the internally mixed soot-containing particles tended to have a more spherical shape and to be embedded into the sulfate. The SP2 measurements also suggested that the proportion of thickly-coated soot was greater. Thus, the observed enhancement of BC light absorption was found to differ according to the mixing states and morphology of soot-containing particles. The enhancement of BC light absorption in our in situ measurements and its relation with individual features of soot-containing particles will be useful to evaluate direct radiative forcing in the leeward areas of large emission sources of BC.
Obermeier, S.F.
1996-01-01
Liquefaction features can be used in many field settings to estimate the recurrence interval and magnitude of strong earthquakes through much of the Holocene. These features include dikes, craters, vented sand, sills, and laterally spreading landslides. The relatively high seismic shaking level required for their formation makes them particularly valuable as records of strong paleo-earthquakes. This state-of-the-art summary for using liquefaction-induced features for paleoseismic interpretation and analysis takes into account both geological and geotechnical engineering perspectives. The driving mechanism for formation of the features is primarily the increased pore-water pressure associated with liquefaction of sand-rich sediment. The role of this mechanism is often supplemented greatly by the direct action of seismic shaking at the ground surface, which strains and breaks the clay-rich cap that lies immediately above the sediment that liquefied. Discussed in the text are the processes involved in formation of the features, as well as their morphology and characteristics in field settings. Whether liquefaction occurs is controlled mainly by sediment grain size, sediment packing, depth to the water table, and strength and duration of seismic shaking. Formation of recognizable features in the field generally requires a low-permeability cap above the sediment that liquefied. Field manifestations are controlled largely by the severity of liquefaction and the thickness and properties of the low-permeability cap. Criteria are presented for determining whether observed sediment deformation in the field originated by seismically induced liquefaction. These criteria have been developed mainly by observing historic effects of liquefaction in varied field settings. The most important criterion is that a seismic liquefaction origin requires widespread, regional development of features around a core area where the effects are most severe. In addition, the features must have a morphology that is consistent with a very sudden application of a large hydraulic force. This article discusses case studies in widely separated and different geological settings: coastal South Carolina, the New Madrid seismic zone, the Wabash Valley seismic zone, and coastal Washington State. These studies encompass most of the range of settings and the types of liquefaction-induced features likely to be encountered anywhere. The case studies describe the observed features and the logic for assigning a seismic liquefaction origin to them. Also discussed are some types of sediment deformations that can be misinterpreted as having a seismic origin. Two independent methods for estimating prehistoric magnitude are discussed briefly. One method is based on determination of the maximum distance from the epicenter over which liquefaction-induced effects have formed. The other method is based on use of geotechnical engineering techniques at sites of marginal liquefaction, in order to bracket the peak accelerations as a function of epicentral distance; these accelerations can then be compared with predictions from seismological models.
Cytotoxic effects of Euterpe oleracea Mart. in malignant cell lines.
Silva, Dulcelena Ferreira; Vidal, Flávia Castello Branco; Santos, Debora; Costa, Maria Célia Pires; Morgado-Díaz, José Andrés; do Desterro Soares Brandão Nascimento, Maria; de Moura, Roberto Soares
2014-05-29
Euterpe oleracea Mart., a plant from the Amazon region, is commonly known as açaí or juçara; it has high nutritional value and elevated levels of lipids, proteins, and minerals. Açaí is an abundant and much consumed fruit by the Amazon local population, and studies have demonstrated that it is rich in phytochemicals with antioxidant, anti-inflammatory, and anticancer activities. Therefore, the aim of this study was to test this plant for anticancer activity in different human malignant cell lines. Cell lines derived from breast and colorectal adenocarcinomas were treated with 10, 20, and 40 μg/mL of bark, seed, and total açaí fruit hydroalcoholic extracts for 24 and 48 h. After treatment, cell viability was measured using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assays, and cell morphological features were observed by light and transmission electron microscopy. The type of cell death was also evaluated. The data were analyzed statistically by one-way analysis of variance (ANOVA), followed by Dunnett's or Tukey's post hoc tests, as appropriate. We observed that of all the cell lines tested, MCF-7 was the only line that responded to açaí treatment. The extracts caused significant reduction (p<0.01) in cell viability and altered cell morphological features by inducing the appearance of autophagic vacuoles, as observed by transmission electron microscopy. Furthermore, increased expression of LC3BII, a protein marker of autophagosome formation, was observed by western blotting. Caspase Glo™ assays and morphologic observations by DAPI nuclear staining and transmission electron microscopy did not indicate any apoptotic events. The present study demonstrated that açaí possesses antitumorigenic potential in the MCF-7 cell line. Further studies are needed to identify the compound (s) responsible for this cytotoxic activity and the molecular target in the cell. This discovery of the anticancer potential of açaí may help in the development of chemopreventive drugs and may have therapeutic effects in the treatment of breast cancer.
Cytotoxic effects of Euterpe oleracea Mart. in malignant cell lines
2014-01-01
Background Euterpe oleracea Mart., a plant from the Amazon region, is commonly known as açaí or juçara; it has high nutritional value and elevated levels of lipids, proteins, and minerals. Açaí is an abundant and much consumed fruit by the Amazon local population, and studies have demonstrated that it is rich in phytochemicals with antioxidant, anti-inflammatory, and anticancer activities. Therefore, the aim of this study was to test this plant for anticancer activity in different human malignant cell lines. Methods Cell lines derived from breast and colorectal adenocarcinomas were treated with 10, 20, and 40 μg/mL of bark, seed, and total açaí fruit hydroalcoholic extracts for 24 and 48 h. After treatment, cell viability was measured using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assays, and cell morphological features were observed by light and transmission electron microscopy. The type of cell death was also evaluated. The data were analyzed statistically by one-way analysis of variance (ANOVA), followed by Dunnett’s or Tukey’s post hoc tests, as appropriate. Results We observed that of all the cell lines tested, MCF-7 was the only line that responded to açaí treatment. The extracts caused significant reduction (p < 0.01) in cell viability and altered cell morphological features by inducing the appearance of autophagic vacuoles, as observed by transmission electron microscopy. Furthermore, increased expression of LC3BII, a protein marker of autophagosome formation, was observed by western blotting. Caspase Glo™ assays and morphologic observations by DAPI nuclear staining and transmission electron microscopy did not indicate any apoptotic events. Conclusions The present study demonstrated that açaí possesses antitumorigenic potential in the MCF-7 cell line. Further studies are needed to identify the compound (s) responsible for this cytotoxic activity and the molecular target in the cell. This discovery of the anticancer potential of açaí may help in the development of chemopreventive drugs and may have therapeutic effects in the treatment of breast cancer. PMID:24886139
Liu, Jia; Li, Wenwu; Huang, Yong; Mu, Dianbin; Yu, Haiying; Li, Shanshan
2015-08-01
The aim of this study was to retrospectively investigate the multi-detector computed tomography (MDCT) features of preinvasive lesions and minimally invasive adenocarcinoma (MIA) appearing as ground-glass nodules (GGNs), and to analyze their significance in differential diagnosis. The pathological data and MDCT images of 111 GGNs in 93 patients were reviewed and analyzed retrospectively, to identify the differentiating CT features between preinvasive lesions and MIA and to evaluate their differentiating accuracy. In the 93 patients included in the study, there were 27 cases with preinvasive lesions (38 GGNs) and 66 cases with MIA (73 GGNs). No statistically significant difference was observed in terms of the gender, age and number of lesions between the two groups. There were significant differences (P<0.05) in the size of lesion, size of solid portion, content of solid portion, and morphological characteristics of the lesion edge between preinvasive lesions and MIA. ROC curve analysis showed that the optimal cut-off value of lesion size for differentiating preinvasive lesions from MIA was 13.0 mm (sensitivity, 83.0%; specificity, 80.0%), and that of solid portion size was 2.0 mm (sensitivity, 90.0%; specificity, 97.0%) and that of solid proportion was 12.0% (sensitivity, 88.0%; specificity, 97.0%). The analysis of CT morphological features showed that there were significant differences in the terms of lesion nature (pGGO, mGGO), presence or absence of lobulated sign and spiculated sign (P<0.05) between preinvasive lesions and MIA, but there were no significant differences in terms of the lesion edge, the presence or absence of vacuole sign, bubble lucency and pleural retraction (P>0.05). Preinvasive lesions can be accurately distinguished from MIA by the size of lesion, size of solid portion,solid proportion and morphological characteristics of the lesion edge. The size of lesion, size of solid portion, content of solid proportion and morphological characteristics of the lesion edge are of significance in the differential diagnosis of preinvasive lesions and minimally invasive adenocarcinoma of the lung.
Visualizing lava flow interiors with LiDAR
NASA Astrophysics Data System (ADS)
Whelley, P.; Garry, W. B.; Young, K.; Kruse, S.; Esmaeili, S.; Bell, E.; Paylor, R.
2017-12-01
Lava tube caves provide unprecedented access to the shallow (meters to tens of meters) interiors of lava flows. Surveying tube geometry and morphology can illuminate lava flow thermal history and emplacement mechanics. In an expedition to Lava Beds National Monument, California, our team collected ultra-high-resolution (< 10 cm) topography from the interiors of four lava tubes using a terrestrial laser scanner (TLS). More than 78 GB of point data (latitude, longitude, elevation) of the surface and interiors of Hercules Leg, Skull, Valentine and, Indian Well Caves were collected. For example, our point cloud for 50 m of Valentine Cave contains 748 million points (interior: 478 million, exterior: 270 million) from 28 TLS scans. The tubes visited range in diameter from < 1 m to > 10 m, and from 1 m to < 20 m of overburden. The interior morphology of the tubes remain pristine (i.e., un-eroded) after more than 10,000 years. The TLS data illuminate fresh-looking lava tube flow features (e.g., lava-coils, pillars, benches, and ropes) and post-emplacement deformation features (e.g., fractures, lava-drips, molded ceilings, and drop-blocks). Furthermore, the data provide context for geochemical and geophysical observations made in conjunction with the TLS survey. Lava tube morphology, observable in the TLS data, informs each tube's emplacement history. Skull cave is the largest ( 20 m in diameter) requiring a comparatively high lava discharge rate and suggesting this cave formed by roofing over a lava channel. In contrast, Valentine, Hercules Leg, and Indian Well Caves are narrower, (1 to 4 m) and have many branches, some of which rejoin the "main passage", suggesting they formed by developing a network of pathways within the lava flow. We will showcase video fly-throughs for these lava tubes, plus manipulable point clouds. The interactive eLighning presentation will encourage hands-on exploration of these unique data. We will guide them on a tour of the underground to discover and compare different morphologies of lava tubes.
Linguistic pattern analysis of misspellings of typically developing writers in grades 1-9.
Bahr, Ruth Huntley; Sillian, Elaine R; Berninger, Virginia W; Dow, Michael
2012-12-01
A mixed-methods approach, evaluating triple word-form theory, was used to describe linguistic patterns of misspellings. Spelling errors were taken from narrative and expository writing samples provided by 888 typically developing students in Grades 1-9. Errors were coded by category (phonological, orthographic, and morphological) and specific linguistic feature affected. Grade-level effects were analyzed with trend analysis. Qualitative analyses determined frequent error types and how use of specific linguistic features varied across grades. Phonological, orthographic, and morphological errors were noted across all grades, but orthographic errors predominated. Linear trends revealed developmental shifts in error proportions for the orthographic and morphological categories between Grades 4 and 5. Similar error types were noted across age groups, but the nature of linguistic feature error changed with age. Triple word-form theory was supported. By Grade 1, orthographic errors predominated, and phonological and morphological error patterns were evident. Morphological errors increased in relative frequency in older students, probably due to a combination of word-formation issues and vocabulary growth. These patterns suggest that normal spelling development reflects nonlinear growth and that it takes a long time to develop a robust orthographic lexicon that coordinates phonology, orthography, and morphology and supports word-specific, conventional spelling.
[About the signs of malignant pheochromocytoma].
Simonenko, V B; Makanin, M A; Dulin, P A; Vasilchenko, M I; Lesovik, V S
2012-01-01
Morphological criteria for malignant pheochromocytoma remain to be developed According to the WHO recommendations, the sole absolute criteria is the presence of metastases in the organs normally containing no chromaffin tissue. Such signs as cellular and nuclear polymorphism, mytotic activity, vascular invasion, capsular ingrowth are not sufficient to describe a pheochromocytoma as malignant. It is equally dfficult to differentiate between malignant and benign tumours based on histological data since histologically mature neoplasms can produce metastases. Based on the results of original studies, the authors believe that such histological features as vascular and capsular invasion do not necessarily suggest unfavourable prognosis. Therefore, the conclusion of malignancy based on such features can not be regarded as absolute. Probably such neoplasms should be called "pheochromocytomas with morphological signs of malignant growths". They should be referred to the tumours with uncertain malignancy potential based on the known discrepancy between morphological structure and biological activity of neoplasms. Comparative studies of clinical and morphological features of pheochromocytomas showed that their histological type (alveolar; solid, dyscomplexed, trabecular) and morphological signs of malignant growth influence both the clinical picture and arterial hypertension. There are no significant relationship between the above morphological signs, timour mass and clinical manifestations of pheochromocytomas.
NASA Astrophysics Data System (ADS)
Lawi, Armin; Adhitya, Yudhi
2018-03-01
The objective of this research is to determine the quality of cocoa beans through morphology of their digital images. Samples of cocoa beans were scattered on a bright white paper under a controlled lighting condition. A compact digital camera was used to capture the images. The images were then processed to extract their morphological parameters. Classification process begins with an analysis of cocoa beans image based on morphological feature extraction. Parameters for extraction of morphological or physical feature parameters, i.e., Area, Perimeter, Major Axis Length, Minor Axis Length, Aspect Ratio, Circularity, Roundness, Ferret Diameter. The cocoa beans are classified into 4 groups, i.e.: Normal Beans, Broken Beans, Fractured Beans, and Skin Damaged Beans. The model of classification used in this paper is the Multiclass Ensemble Least-Squares Support Vector Machine (MELS-SVM), a proposed improvement model of SVM using ensemble method in which the separate hyperplanes are obtained by least square approach and the multiclass procedure uses One-Against- All method. The result of our proposed model showed that the classification with morphological feature input parameters were accurately as 99.705% for the four classes, respectively.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Fried, D; Zhang, L; Fave, X
Purpose: Determine the impact of morphologic characteristics (e.g. necrosis, vascular enhancement, and cavitation) on radiomic features from contrast enhanced CT (CE-CT) in primary lung tumors. Methods: We developed an auto-segmentation algorithm to separate lung tumors on contrast-enhanced CT into cavitation (air), necrosis, tissue, and enhancing vessels using a combination of thresholding and region-growing. An auto-segmentation algorithm was also designed to identify necrosis on FDG-PET scans. Wilcoxon rank-sum tests were used to determine if significant differences existed in radiomics features (histogram-uniformity and Laplacian-of-Gaussian average) from 249 patients, found to prognostic in previous work, based on the presence/absence of morphologic features. Featuremore » values were also compared between the original tumor contours and contours excluding a specific morphologic feature. Comparison of necrosis segmentation on CE-CT versus FDG-PET was performed in 78 patients to assess for agreement using the concordance correlation coefficient (CCC). Results: Tumors with cavitation and enhancing vasculature had lower uniformity values (p = 0.001 and p = 0.03, respectively). Tumors with enhancing vasculature and necrosis had higher Laplacian-of-Gaussian average values (measure of “edges” within the tumor) (p < 0.001). Removing these tissue types from regions-of-interest did not drastically alter either radiomic feature value (all scenarios had R{sup 2} > 0.8). This suggests there may be interactions between morphologic characteristics and the radiomic feature value of tumor tissue. Comparison of necrosis volume and percent necrosis volume of tumor were found to have CCC values of 0.85 and 0.76, respectively between CE-CT and FDG-PET segmentation methods. Conclusions: Tumors with enhancing vasculature, necrosis, and cavitation have higher radiomic feature values that are associated with poor prognosis than tumors without these features. Removing these tissue types from quantitative assessment did not drastically impact radiomic feature values. High reproducibility of CE-CT segmented necrosis compared to FDG-PET segmented necrosis provides a reasonable validation of segmentation accuracy on CE-CT.« less
Hepatocyte Paraffin 1 Antigen as a Biomarker for Early Diagnosis of Barrett Esophagus
Jeung, Jennifer A.; Coran, Justin J.; Liu, Chen; Cardona, Diana M.
2013-01-01
We evaluated hepatocyte paraffin 1 (HepPar1) antigen expression, a sensitive marker of small intestinal differentiation, in combination with morphologic features to demonstrate intestinal differentiation in cases equivocal for Barrett esophagus (BE). Clinicopathologic features and HepPar1 expression were recorded for 54 BE cases, 45 consistent with reflux esophagitis (RE) cases, and 65 “suspicious” for BE (SBE) cases. The SBE category included RE cases with 2 or more morphologic changes associated with BE or metaplastic reaction to injury (eg, multilayered epithelium, squamous islands, goblet cell mimickers, pancreatic metaplasia). HepPar1 was expressed in all 54 BE cases, 4 of 45 RE cases, and 24 of 65 SBE cases. In SBE cases, 2 or more morphologic changes were associated with HepPar1 expression in 37% of cases (24/65), 3 or more features in 59% (13/22), and 4 or more features in 100% (4/4) (P ≤ .004). The combination of certain morphologic changes and HepPar1 expression in clinically suspicious distal esophageal biopsy cases without goblet cells supports the presence of evolving intestinal metaplasia. PMID:22180484
NASA Astrophysics Data System (ADS)
Davis, Benjamin L.; Berrier, Joel C.; Shields, Douglas W.; Kennefick, Julia; Kennefick, Daniel; Seigar, Marc S.; Lacy, Claud H. S.; Puerari, Ivânio
2012-04-01
A logarithmic spiral is a prominent feature appearing in a majority of observed galaxies. This feature has long been associated with the traditional Hubble classification scheme, but historical quotes of pitch angle of spiral galaxies have been almost exclusively qualitative. We have developed a methodology, utilizing two-dimensional fast Fourier transformations of images of spiral galaxies, in order to isolate and measure the pitch angles of their spiral arms. Our technique provides a quantitative way to measure this morphological feature. This will allow comparison of spiral galaxy pitch angle to other galactic parameters and test spiral arm genesis theories. In this work, we detail our image processing and analysis of spiral galaxy images and discuss the robustness of our analysis techniques.
Wang, Jason J.; Graham, James R.; Pueyo, Laurent; ...
2015-09-23
We present Gemini Planet Imager (GPI) observations of AU Microscopii, a young M dwarf with an edge-on, dusty debris disk. Integral field spectroscopy and broadband imaging polarimetry were obtained during the commissioning of GPI. In our broadband imaging polarimetry observations, we detect the disk only in total intensity and find asymmetries in the morphology of the disk between the southeast (SE) and northwest (NW) sides. The SE side of the disk exhibits a bump at 1'' (10 AU projected separation) that is three times more vertically extended and three times fainter in peak surface brightness than the NW side atmore » similar separations. This part of the disk is also vertically offset by 69 ± 30 mas to the northeast at 1'' when compared to the established disk midplane and is consistent with prior Atacama Large Millimeter/submillimeter Array and Hubble Space Telescope/Space Telescope Imaging Spectrograph observations. We see hints that the SE bump might be a result of detecting a horizontal sliver feature above the main disk that could be the disk backside. Alternatively, when including the morphology of the NW side, where the disk midplane is offset in the opposite direction ~50 mas between 0farcs4 and 1farcs2, the asymmetries suggest a warp-like feature. Using our integral field spectroscopy data to search for planets, we are 50% complete for ~4 MJup planets at 4 AU. Lastly, we detect a source, resolved only along the disk plane, that could either be a candidate planetary mass companion or a compact clump in the disk.« less
Stefanik, Joshua J; Zumwalt, Ann C; Segal, Neil A; Lynch, John A; Powers, Christopher M
2013-08-01
Patellofemoral joint (PFJ) malalignment (lateral patella displacement and tilt) has been proposed as a cause of patellofemoral pain. Patella height and/or the morphologic features of the femoral trochlea may predispose one to patella malalignment. The purposes of our study were to assess the associations among patella height, morphologic features of the trochlea, and measures of PFJ alignment and to determine which measures of patella height and morphologic features of the trochlea were the best predictors of PFJ alignment. Measures of patella height (Insall-Salvati ratio and modified Insall-Salvati ratio), morphologic features of the trochlea (sulcus angle, trochlear angle, lateral trochlear inclination, medial trochlear inclination), and PFJ alignment (bisect offset and patella tilt angle) were assessed in 566 knees from the Multicenter Osteoarthritis Study. Bisect offset was correlated with the Insall-Salvati ratio (r = 0.25) and lateral trochlear inclination (r = -0.38). Patella tilt angle correlated with the trochlear angle (-0.27) and lateral trochlear inclination (-0.32). Linear regression models including the Insall-Salvati ratio and lateral trochlear inclination explained 20% and 11% of the variance in bisect offset and patella tilt angle, respectively. Of the variables measured in the current study, the Insall-Salvati ratio and lateral trochlear inclination were the best predictors of lateral patella displacement and lateral tilt. This knowledge will aid clinicians in the identification of anatomic risk factors for PFJ malalignment and/or PFJ dysfunction.
Morphology, stratigraphy, and surface roughness properties of Venusian lava flow fields
NASA Astrophysics Data System (ADS)
Byrnes, Jeffrey M.; Crown, David A.
2002-10-01
Morphologic characteristics, flow stratigraphy, and radar backscatter properties of five lava flow fields on Venus (Turgmam Fluctus, Zipaltonal Fluctus, Tuli Mons/Uilata Fluctus, Var Mons, and Mylitta Fluctus) were examined to understand flow field emplacement mechanisms and relationships to other surface processes. These analyses indicate that the flow fields studied developed through emplacement of numerous, thin flow units, presumably over extended periods of time. Although the Venusian fields display flow morphologies similar to those observed within terrestrial flow fields, the Venusian flow units are significantly larger and have a larger range of radar backscatter coefficients. Both simple and compound flow emplacement appear to have occurred within the flow fields. A potential correlation between flow rheology and radar brightness is suggested by differences in planform morphology, apparent flow thickness, and apparent sensitivity to topography between bright and dark flows. Distributary flow morphologies may result from tube-fed flows, and postemplacement modification by processes such as flow inflation and crustal foundering is consistent with discrete zones of increased radar brightness within individual flow lobes. Mapping of these flow fields does not indicate any simple evolutionary trend in eruptive/resurfacing style within the flow fields, or any consistent temporal sequence relative to other tectonic and volcanic features.
Ford, Antonia G P; Rüber, Lukas; Newton, Jason; Dasmahapatra, Kanchon K; Balarin, John D; Bruun, Kristoffer; Day, Julia J
2016-12-01
Ecomorphological differentiation is a key feature of adaptive radiations, with a general trend for specialization and niche expansion following divergence. Ecological opportunity afforded by invasion of a new habitat is thought to act as an ecological release, facilitating divergence, and speciation. Here, we investigate trophic adaptive morphology and ecology of an endemic clade of oreochromine cichlid fishes (Alcolapia) that radiated along a herbivorous trophic axis following colonization of an isolated lacustrine environment, and demonstrate phenotype-environment correlation. Ecological and morphological divergence of the Alcolapia species flock are examined in a phylogenomic context, to infer ecological niche occupation within the radiation. Species divergence is observed in both ecology and morphology, supporting the importance of ecological speciation within the radiation. Comparison with an outgroup taxon reveals large-scale ecomorphological divergence but shallow genomic differentiation within the Alcolapia adaptive radiation. Ancestral morphological reconstruction suggests lake colonization by a generalist oreochromine phenotype that diverged in Lake Natron to varied herbivorous morphologies akin to specialist herbivores in Lakes Tanganyika and Malawi. © 2016 The Author(s). Evolution published by Wiley Periodicals, Inc. on behalf of The Society for the Study of Evolution.
Palanisamy, Vinupritha; Mariamichael, Anburajan
2016-10-01
Background and Aim: Diabetes mellitus is a metabolic disorder characterized by varying hyperglycemias either due to insufficient secretion of insulin by the pancreas or improper utilization of glucose. The study was aimed to investigate the association of morphological features of erythrocytes among normal and diabetic subjects and its gender-based changes and thereby to develop a computer aided tool to diagnose diabetes using features extracted from RBC. Materials and Methods: The study involved 138 normal and 144 diabetic subjects. The blood was drawn from the subjects and the blood smear prepared was digitized using Zeiss fluorescent microscope. The digitized images were pre-processed and texture segmentation was performed to extract the various morphological features. The Pearson correlation test was performed and subsequently, classification of subjects as normal and diabetes was carried out by a neural network classifier based on the features that demonstrated significance at the level of P <0.05. Result: The proposed system demonstrated an overall accuracy, sensitivity, specificity, positive predictive value and negative predictive value of 93.3, 93.71, 92.8, 93.1 and 93.5% respectively. Conclusion: The morphological features exhibited a statistically significant difference (P<0.01) between the normal and diabetic cells, suggesting that it could be helpful in the diagnosis of Diabetes mellitus using a computer aided system. © Georg Thieme Verlag KG Stuttgart · New York.
NASA Astrophysics Data System (ADS)
Bunte, M. K.; Tanaka, K. L.; Doggett, T.; Figueredo, P. H.; Lin, Y.; Greeley, R.; Saripalli, S.; Bell, J. F.
2013-12-01
Europa's extremely young surface age, evidence for extensive resurfacing, and indications of a sub-surface ocean elevate its astrobiological potential for habitable environments and make it a compelling focus for study. Knowledge of the global distribution and timing of Europan geologic units is a key step in understanding the history of the satellite and for identifying areas relevant for exploration. I have produced a 1:15M scale global geologic map of Europa which represents a proportionate distribution of four unit types and associated features: plains, linea, chaos, and crater materials. Mapping techniques differ somewhat from other planetary maps but do provide a method to establish stratigraphic markers and to illustrate the surface history through four periods of formation as a function of framework lineament cross-cutting relationships. Correlations of observed features on Europa with Earth analogs enforce a multi-process theory for formation rather than the typical reliance on the principle of parsimony. Lenticulae and microchaos are genetically similar and most likely form by diapirism. Platy and blocky chaos units, endmembers of archetypical chaos, are best explained by brine mobilization. Ridges account for the majority of lineaments and may form by a number of methods indicative of local conditions; most form by either tidal pumping or shear heating. The variety of morphologies exhibited by bands indicates that multiple formation mechanisms apply once fracturing of the brittle surface over a ductile subsurface is initiated. Mapping results support the interpretation that Europa's shell has thickened over time resulting in changes in the style and intensity of deformation. Mapping serves as an index for change detection and classification, aids in pre-encounter targeting, and supports the selection of potential landing sites. Highest priority target areas are those which indicate geophysical activity by the presence of volcanic plumes, outgassing, or disrupted surface morphologies. Areas of high interest include lineaments and chaos margins. The limitations on detecting activity at these locations are approximated by studying similar observed conditions on other bodies. By adapting machine learning and data mining techniques to signatures of plumes and morphology, I have demonstrated autonomous rule-based detection of known features using edge-detection and supervised classification methods. These methods successfully detect ≤94% of known volcanic plumes or jets at Io, Enceladus, and comets. They also allow recognition of multiple feature types. Applying these results to conditions expected for Europa enables a prediction of the potential for detection of similar features and enables recommendations for mission concepts to increase the science return and efficiency of future missions to observe Europa. This post-Galileo view of Europa provides a synthesis of the overall history of this unique icy satellite and will be a useful frame of reference for future exploration of the jovian system and other potentially active outer solar system bodies.
NASA Astrophysics Data System (ADS)
Jaferzadeh, Keyvan; Moon, Inkyu
2016-12-01
The classification of erythrocytes plays an important role in the field of hematological diagnosis, specifically blood disorders. Since the biconcave shape of red blood cell (RBC) is altered during the different stages of hematological disorders, we believe that the three-dimensional (3-D) morphological features of erythrocyte provide better classification results than conventional two-dimensional (2-D) features. Therefore, we introduce a set of 3-D features related to the morphological and chemical properties of RBC profile and try to evaluate the discrimination power of these features against 2-D features with a neural network classifier. The 3-D features include erythrocyte surface area, volume, average cell thickness, sphericity index, sphericity coefficient and functionality factor, MCH and MCHSD, and two newly introduced features extracted from the ring section of RBC at the single-cell level. In contrast, the 2-D features are RBC projected surface area, perimeter, radius, elongation, and projected surface area to perimeter ratio. All features are obtained from images visualized by off-axis digital holographic microscopy with a numerical reconstruction algorithm, and four categories of biconcave (doughnut shape), flat-disc, stomatocyte, and echinospherocyte RBCs are interested. Our experimental results demonstrate that the 3-D features can be more useful in RBC classification than the 2-D features. Finally, we choose the best feature set of the 2-D and 3-D features by sequential forward feature selection technique, which yields better discrimination results. We believe that the final feature set evaluated with a neural network classification strategy can improve the RBC classification accuracy.
Paul, Rituparna; Karabiyik, Ufuk; Swift, Michael C; Hottle, John R; Esker, Alan R
2008-05-06
Morphological evolution in dewetting thin film bilayers of polystyrene (PS) and a polyhedral oligomeric silsesquioxane (POSS), trisilanolphenyl-POSS (TPP), was studied as a function of annealing temperature and annealing time. The results demonstrate unique dewetting morphologies in PS/TPP bilayers at elevated temperatures that are significantly different from those typically observed in dewetting polymer/polymer bilayers. During temperature ramp studies by optical microscopy (OM) in the reflection mode, PS/TPP bilayers form cracks with a weak optical contrast at approximately 130 degrees C. The crack formation is attributed to tensile stresses within the upper TPP layer. The weak optical contrast of the cracks observed in the bilayers for annealing temperatures below approximately 160 degrees C is consistent with the cracking and dewetting of only the upper TPP layer from the underlying PS layer. The optical contrast of the morphological features is significantly enhanced at annealing temperatures of >160 degrees C. This observation suggests dewetting of both the upper TPP and the lower PS layers that results in the exposure of the silicon substrate. Upon annealing the PS/TPP bilayers at 200 degrees C in a temperature jump experiment, the upper TPP layer undergoes instantaneous cracking as observed by OM. These cracks in the upper TPP layer serve as nucleation sites for rapid dewetting and aggregation of the TPP layer, as revealed by OM and atomic force microscopy (AFM). X-ray photoelectron spectroscopy (XPS) results indicated that dewetting of the lower PS layer ensued for annealing times >5 min and progressed up to 90 min. For annealing times >90 min, OM, AFM, and XPS results revealed complete dewetting of both the layers with the formation of TPP encapsulated PS droplets.
Directly observable optical properties of sprites in Central Europe
NASA Astrophysics Data System (ADS)
Bór, József
2013-04-01
Luminous optical emissions accompanying streamer-based natural electric breakdown processes initiating in the mesosphere are called sprites. 489 sprite events have been observed with a TV frame rate video system in Central Europe from Sopron (47.68N, 16.58E, 230 m MSL), Hungary between 2007 and 2009. On the basis of these observations, characteristic morphological properties of sprites, i.e. basic forms (e.g. column, carrot, angel, etc.) as well as common morphological features (e.g. tendrils, glows, puffs, beads, etc.), have been identified. Probable time sequences of streamer propagation directions were associated with each of the basic sprite forms. It is speculated that different sequences of streamer propagation directions can result in very similar final sprite shapes. The number and type variety of sprite elements appearing in an event as well as the total optical duration of an event was analyzed statistically. Jellyfish and dancing sprite events were considered as special subsets of sprite clusters. It was found that more than 90% of the recorded sprite elements appeared in clusters rather than alone and more than half of the clusters contained more than one basic sprite forms. The analysis showed that jellyfish sprites and clusters of column sprites featuring glows and tendrils do not tend to have optical lifetimes longer than 80 ms. Such very long optical lifetimes have not been observed in sprite clusters containing more than 25 elements of any type, either. In contrast to clusters containing sprite entities of only one form, sprite events showing more sprite forms seem to have extended optical durations more likely. The need for further investigation and for finding theoretical concepts to link these observations to electric conditions ambient for sprite formation is emphasized.
Automated Feature Extraction of Foredune Morphology from Terrestrial Lidar Data
NASA Astrophysics Data System (ADS)
Spore, N.; Brodie, K. L.; Swann, C.
2014-12-01
Foredune morphology is often described in storm impact prediction models using the elevation of the dune crest and dune toe and compared with maximum runup elevations to categorize the storm impact and predicted responses. However, these parameters do not account for other foredune features that may make them more or less erodible, such as alongshore variations in morphology, vegetation coverage, or compaction. The goal of this work is to identify other descriptive features that can be extracted from terrestrial lidar data that may affect the rate of dune erosion under wave attack. Daily, mobile-terrestrial lidar surveys were conducted during a 6-day nor'easter (Hs = 4 m in 6 m water depth) along 20km of coastline near Duck, North Carolina which encompassed a variety of foredune forms in close proximity to each other. This abstract will focus on the tools developed for the automated extraction of the morphological features from terrestrial lidar data, while the response of the dune will be presented by Brodie and Spore as an accompanying abstract. Raw point cloud data can be dense and is often under-utilized due to time and personnel constraints required for analysis, since many algorithms are not fully automated. In our approach, the point cloud is first projected into a local coordinate system aligned with the coastline, and then bare earth points are interpolated onto a rectilinear 0.5 m grid creating a high resolution digital elevation model. The surface is analyzed by identifying features along each cross-shore transect. Surface curvature is used to identify the position of the dune toe, and then beach and berm morphology is extracted shoreward of the dune toe, and foredune morphology is extracted landward of the dune toe. Changes in, and magnitudes of, cross-shore slope, curvature, and surface roughness are used to describe the foredune face and each cross-shore transect is then classified using its pre-storm morphology for storm-response analysis.
Wang, Gang; Wang, Yalin
2017-02-15
In this paper, we propose a heat kernel based regional shape descriptor that may be capable of better exploiting volumetric morphological information than other available methods, thereby improving statistical power on brain magnetic resonance imaging (MRI) analysis. The mechanism of our analysis is driven by the graph spectrum and the heat kernel theory, to capture the volumetric geometry information in the constructed tetrahedral meshes. In order to capture profound brain grey matter shape changes, we first use the volumetric Laplace-Beltrami operator to determine the point pair correspondence between white-grey matter and CSF-grey matter boundary surfaces by computing the streamlines in a tetrahedral mesh. Secondly, we propose multi-scale grey matter morphology signatures to describe the transition probability by random walk between the point pairs, which reflects the inherent geometric characteristics. Thirdly, a point distribution model is applied to reduce the dimensionality of the grey matter morphology signatures and generate the internal structure features. With the sparse linear discriminant analysis, we select a concise morphology feature set with improved classification accuracies. In our experiments, the proposed work outperformed the cortical thickness features computed by FreeSurfer software in the classification of Alzheimer's disease and its prodromal stage, i.e., mild cognitive impairment, on publicly available data from the Alzheimer's Disease Neuroimaging Initiative. The multi-scale and physics based volumetric structure feature may bring stronger statistical power than some traditional methods for MRI-based grey matter morphology analysis. Copyright © 2016 Elsevier Inc. All rights reserved.
Aspects of vertebrate gustatory phylogeny: morphology and turnover of chick taste bud cells.
Ganchrow, J R; Ganchrow, D; Royer, S M; Kinnamon, J C
1993-10-01
The taste bud is a receptor form observed across vertebrates. The present report compares chick taste buds to those of other vertebrates using light and electron microscopy. Unlike mammals, but common to many modern avians, the dorsal surface of chick anterior tongue lacks taste papillae and taste buds. Ultrastructurally, chick buds located in the anterior floor of the mouth (as in some reptiles and amphibians) and palate contain dark, intermediate, light, and basal cell types. Dark, intermediate, and light cells extend microvilli into intragemmal lumina and pores communicating with the oral cavity. As specialized features, dark cell apices lack dense granules and exhibit short microvilli relative to light and intermediate cells. Dark cell cytoplasmic fingers envelop intragemmal nerve fibers and cells as in other species, and sometimes contain abundant clear vesicles. Nerve profile expansions often are located adjacent to dark, intermediate, and light cell nuclei. Classical afferent synaptic contacts are rarely observed. Taste cell turnover is suggested by mitotic and degenerating figures in chick buds. In addition, tritiated thymidine injected into hatchlings, whose anterior mandibular oral taste bud population approximates that in adults, reveals a turnover rate of about 4.5 days. This is about half that observed in altricial mammals, reflecting a species difference or developmental factor in precocial avians. It is concluded that chick taste buds exhibit morphologic features common to other vertebrate buds with specializations reflecting the influences of niche, glandular relations, and/or age.
Occurrence of neanderthal features in mandibles from the Atapuerca-SH site.
Rosas, A
2001-01-01
Analysis of variation and distribution of evolutionary novelties is meaningful in understanding evolutionary processes. The mandible, as a morphological complex, comprises a large number of derived Neanderthal features. The present study investigates whether the features usually considered as European lineage apomorphies evolved independently; the occurrence of these features is studied in the mandibles from the Sima de los Huesos (SH) site (Atapuerca, Spain). For comparative purposes, a large sample of Neanderthal mandibles as well as older fossil Homo specimens have been used for the study. Chi-square tests were employed to test for independence. The SH mandibles present a set of features that clearly show the basic architecture of the Neanderthal mandible. A highly significant association is detected in the variation of the position of the mental foramen, the lateral prominence, and the anterior marginal tubercle, as well as in the development of retromolar space. However, a much weaker association is detected in the features of the internal aspect of the mandible, with a few exceptions. Features of the external aspect of the mandible occur chronologically earlier than those observed in the internal aspect. The hypothesis that two distinct and consecutive morphological processes have driven the emergence of the European lineage throughout the Middle Pleistocene is proposed. A first transformation affects the mandible by means of backwards displacement of the structures located at the external aspect, as well as the position of the condyle. A second process would modify the features of the internal aspect of the mandible, in which the relief of the masseteric and pterygoid fossae are affected, in association with a spatial rearrangement of the corpus and ramus. Analyzed individually, some of the considered features may be questioned as Neanderthal apomorphies (Trinkaus,1993; Franciscus and Trinkaus, 995); however, the joint occurrence of many of them suggests that the complex is an evolutionary novelty. Copyright 2001 Wiley-Liss, Inc.
Ovipositor morphology correlates with life history evolution in agaonid fig wasps
NASA Astrophysics Data System (ADS)
Elias, Larissa Galante; Kjellberg, Finn; Farache, Fernando Henrique Antoniolli; Almeida, Eduardo A. B.; Rasplus, Jean-Yves; Cruaud, Astrid; Peng, Yan-Qiong; Yang, Da-Rong; Pereira, Rodrigo Augusto Santinelo
2018-07-01
The high adaptive success of parasitic Hymenoptera might be related to the use of different oviposition sites, allowing niche partitioning among co-occurring species resulting in life history specialization and diversification. In this scenario, evolutionary changes in life history and resources for oviposition can be associated with changes in ovipositor structure, allowing exploitation of different substrates for oviposition. We used a formal phylogenetic framework to investigate the evolution of ovipositor morphology and life history in agaonid wasps. We sampled 24 species with different life histories belonging to all main clades of Agaonidae including representatives of all described genera of non-pollinating fig wasps (NPFW). Our results show an overall correlation between ovipositor morphology and life history in agaonid fig wasps. Ovipositor morphologies seem to be related to constraints imposed by features of the oviposition sites since ovipositor morphology has experienced convergent evolution at least four times in Sycophaginae (Agaonidae) according to the resource used. Non-galling species have more distantly spaced teeth with uneven spacing, as opposed to the observed morphology of galling species. Our results suggest that the ancestral condition for ovipositor morphology was most likely the presence of one or two apical teeth. Regarding life history, ovary galling species that oviposit in receptive figs possibly represent the ancestral condition. Different ovipositor characteristics allow exploitation of new niches and may be related to resource partitioning and species co-existence in the fig-fig wasp system.
Ortiz, Alejandra; Skinner, Matthew M; Bailey, Shara E; Hublin, Jean-Jacques
2012-10-01
Carabelli's trait is a morphological feature that frequently occurs on the mesiolingual aspect of Homo sapiens upper molars. Similar structures also referred to as Carabelli's trait have been reported in apes and fossil hominins. However, the morphological development and homology of these mesiolingual structures among hominoids are poorly understood. In this study, we employ micro-computed tomography to image the enamel-dentine junction (EDJ) and outer enamel surface (OES) of Pan (n = 48) and H. sapiens (n = 52) upper molars. We investigate the developmental origin of mesiolingual features in these taxa and establish the relative contribution of the EDJ and enamel cap to feature expression. Results demonstrate that mesiolingual features of H. sapiens molars develop at the EDJ and are similarly expressed at the OES. Morphological variation at both surfaces in this taxon can satisfactorily be assessed using standards for Carabelli's trait developed by the Arizona State University Dental Anthropology System (ASUDAS). Relative to H. sapiens, Pan has an even greater degree of correspondence in feature expression between the EDJ and OES. Morphological manifestations in Pan molars are not necessarily limited to the protocone and are best characterized by a lingual cingulum that cannot be captured by the ASUDAS. Cusp-like structures, similar to those seen in marked Carabelli's trait expressions in H. sapiens, were not found in Pan. This study provides a foundation for further analyses on the evolutionary history of mesiolingual dental traits within the hominoid lineage. It also highlights the wealth of morphological data that can be obtained at the EDJ for understanding tooth development and for characterizing tooth crown variation in worn fossil teeth. Copyright © 2012 Elsevier Ltd. All rights reserved.
Comparison of organs' shapes with geometric and Zernike 3D moments.
Broggio, D; Moignier, A; Ben Brahim, K; Gardumi, A; Grandgirard, N; Pierrat, N; Chea, M; Derreumaux, S; Desbrée, A; Boisserie, G; Aubert, B; Mazeron, J-J; Franck, D
2013-09-01
The morphological similarity of organs is studied with feature vectors based on geometric and Zernike 3D moments. It is particularly investigated if outliers and average models can be identified. For this purpose, the relative proximity to the mean feature vector is defined, principal coordinate and clustering analyses are also performed. To study the consistency and usefulness of this approach, 17 livers and 76 hearts voxel models from several sources are considered. In the liver case, models with similar morphological feature are identified. For the limited amount of studied cases, the liver of the ICRP male voxel model is identified as a better surrogate than the female one. For hearts, the clustering analysis shows that three heart shapes represent about 80% of the morphological variations. The relative proximity and clustering analysis rather consistently identify outliers and average models. For the two cases, identification of outliers and surrogate of average models is rather robust. However, deeper classification of morphological feature is subject to caution and can only be performed after cross analysis of at least two kinds of feature vectors. Finally, the Zernike moments contain all the information needed to re-construct the studied objects and thus appear as a promising tool to derive statistical organ shapes. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.
Molecular Effects on Coacervate-Driven Block Copolymer Self Assembly
NASA Astrophysics Data System (ADS)
Lytle, Tyer; Radhakrishna, Mithun; Sing, Charles
Two oppositely charged polymers can undergo associative phase separation in a salt solution in a process known as \\x98complex coacervation. Recent work has used this as a motif to control the self-assembly behavior of a mixture of oppositely-charged block copolymers which form nanoscale structures. The materials formed from these complex coacervate-block copolymers (BCPs) have potential use as drug delivery systems, gels, and sensors. We have developed a hybrid Monte Carlo-Single Chain in a Mean Field (MC-SCMF) simulation method that is able to determine morphological phase diagrams for BCPs. This technique is an efficient way to calculate morphological phase diagrams and provides a clear link between molecular level features and self-assembly behaviors. Morphological phase diagrams showing the effects of polymer concentration, salt concentration, chain length, and charge-block fraction at large charge densities on self-assembly behavior have been determined. An unexpected phase transition from disorder to hexagonal packing at large salt concentrations has been observed for charge-block fractions equal to and larger than 0.5. This is attributed to the salt filling space stabilizing the morphology of the BCP.
Electron microscopic examination of uncultured soil-dwelling bacteria.
Amako, Kazunobu; Takade, Akemi; Taniai, Hiroaki; Yoshida, Shin-ichi
2008-05-01
Bacteria living in soil collected from a rice paddy in Fukuoka, Japan, were examined by electron microscopy using a freeze-substitution fixation method. Most of the observed bacteria could be categorized, based on the structure of the cell envelope and overall morphology, into one of five groups: (i) bacterial spore; (ii) Gram-positive type; (iii) Gram-negative type; (iv) Mycobacterium like; and (v) Archaea like. However, a few of the bacteria could not be readily categorized into one of these groups because they had unique cell wall structures, basically resembling those of Gram-negative bacteria, but with the layer corresponding to the peptidoglycan layer in Gram-negative bacteria being extremely thick, like that of the cortex of a bacterial spore. The characteristic morphological features found in many of these uncultured, soil-dwelling cells were the nucleoid being in a condensed state and the cytoplasm being shrunken. We were able to produce similar morphologies in vitro using a Salmonella sp. by culturing under low-temperature, low-nutrient conditions, similar to those found in some natural environments. These unusual morphologies are therefore hypothesized to be characteristic of bacteria in resting or dormant stages.
Tan, Tzer Han; Silverberg, Jesse L; Floss, Daniela S; Harrison, Maria J; Henley, Christopher L; Cohen, Itai
2015-10-20
Experimental studies show that plant root morphologies can vary widely from straight gravity-aligned primary roots to fractal-like root architectures. However, the opaqueness of soil makes it difficult to observe how environmental factors modulate these patterns. Here, we combine a transparent hydrogel growth medium with a custom built 3D laser scanner to directly image the morphology of Medicago truncatula primary roots. In our experiments, root growth is obstructed by an inclined plane in the growth medium. As the tilt of this rigid barrier is varied, we find Medicago transitions between randomly directed root coiling, sinusoidal root waving, and normal gravity-aligned morphologies. Although these root phenotypes appear morphologically distinct, our analysis demonstrates the divisions are less well defined, and instead, can be viewed as a 2D biased random walk that seeks the path of steepest decent along the inclined plane. Features of this growth response are remarkably similar to the widely known run-and-tumble chemotactic behavior of Escherichia coli bacteria, where biased random walks are used as optimal strategies for nutrient uptake.
Landry, C; Geyer, L B; Arakaki, Y; Uehara, T; Palumbi, Stephen R
2003-01-01
The rich species diversity of the marine Indo-West Pacific (IWP) has been explained largely on the basis of historical observation of large-scale diversity gradients. Careful study of divergence among closely related species can reveal important new information about the pace and mechanisms of their formation, and can illuminate the genesis of biogeographic patterns. Young species inhabiting the IWP include urchins of the genus Echinometra, which diverged over the past 1-5 Myr. Here, we report the most recent divergence of two cryptic species of Echinometra inhabiting this region. Mitochondrial cytochrome oxidase 1 (CO1) sequence data show that in Echinometra oblonga, species-level divergence in sperm morphology, gamete recognition proteins and gamete compatibility arose between central and western Pacific populations in the past 250 000 years. Divergence in sperm attachment proteins suggests rapid evolution of the fertilization system. Divergence of sperm morphology may be a common feature of free-spawning animals, and offers opportunities to simultaneously understand genetic divergence, changes in protein expression patterns and morphological evolution in traits directly related to reproductive isolation. PMID:12964987
A quantitative framework for flower phenotyping in cultivated carnation (Dianthus caryophyllus L.).
Chacón, Borja; Ballester, Roberto; Birlanga, Virginia; Rolland-Lagan, Anne-Gaëlle; Pérez-Pérez, José Manuel
2013-01-01
Most important breeding goals in ornamental crops are plant appearance and flower characteristics where selection is visually performed on direct offspring of crossings. We developed an image analysis toolbox for the acquisition of flower and petal images from cultivated carnation (Dianthus caryophyllus L.) that was validated by a detailed analysis of flower and petal size and shape in 78 commercial cultivars of D. caryophyllus, including 55 standard, 22 spray and 1 pot carnation cultivars. Correlation analyses allowed us to reduce the number of parameters accounting for the observed variation in flower and petal morphology. Convexity was used as a descriptor for the level of serration in flowers and petals. We used a landmark-based approach that allowed us to identify eight main principal components (PCs) accounting for most of the variance observed in petal shape. The effect and the strength of these PCs in standard and spray carnation cultivars are consistent with shared underlying mechanisms involved in the morphological diversification of petals in both subpopulations. Our results also indicate that neighbor-joining trees built with morphological data might infer certain phylogenetic relationships among carnation cultivars. Based on estimated broad-sense heritability values for some flower and petal features, different genetic determinants shall modulate the responses of flower and petal morphology to environmental cues in this species. We believe our image analysis toolbox could allow capturing flower variation in other species of high ornamental value.
Theory of multiple quantum dot formation in strained-layer heteroepitaxy
DOE Office of Scientific and Technical Information (OSTI.GOV)
Du, Lin; Maroudas, Dimitrios, E-mail: maroudas@ecs.umass.edu
2016-07-11
We develop a theory for the experimentally observed formation of multiple quantum dots (QDs) in strained-layer heteroepitaxy based on surface morphological stability analysis of a coherently strained epitaxial thin film on a crystalline substrate. Using a fully nonlinear model of surface morphological evolution that accounts for a wetting potential contribution to the epitaxial film's free energy as well as surface diffusional anisotropy, we demonstrate the formation of multiple QD patterns in self-consistent dynamical simulations of the evolution of the epitaxial film surface perturbed from its planar state. The simulation predictions are supported by weakly nonlinear analysis of the epitaxial filmmore » surface morphological stability. We find that, in addition to the Stranski-Krastanow instability, long-wavelength perturbations from the planar film surface morphology can trigger a nonlinear instability, resulting in the splitting of a single QD into multiple QDs of smaller sizes, and predict the critical wavelength of the film surface perturbation for the onset of the nonlinear tip-splitting instability. The theory provides a fundamental interpretation for the observations of “QD pairs” or “double QDs” and other multiple QDs reported in experimental studies of epitaxial growth of semiconductor strained layers and sets the stage for precise engineering of tunable-size nanoscale surface features in strained-layer heteroepitaxy by exploiting film surface nonlinear, pattern forming phenomena.« less
NASA Astrophysics Data System (ADS)
Fundis, A. T.; Soule, S. A.; Fornari, D. J.; Perfit, M. R.
2010-08-01
The 2005-2006 eruptions near 9°50'N at the East Pacific Rise (EPR) marked the first observed repeat eruption at a mid-ocean ridge and provided a unique opportunity to deduce the emplacement dynamics of submarine lava flows. Since these new flows were documented in April 2006, a total of 40 deep-towed imaging surveys have been conducted with the Woods Hole Oceanographic Institution's (WHOI) TowCam system. More than 60,000 digital color images and high-resolution bathymetric profiles of the 2005-2006 flows from the TowCam surveys were analyzed for lava flow morphology and for the presence of kipukas, collapse features, faults and fissures. We use these data to quantify the spatial distributions of lava flow surface morphologies and to investigate how they relate to the physical characteristics of the ridge crest, such as seafloor slope, and inferred dynamics of flow emplacement. We conclude that lava effusion rate was the dominant factor controlling the observed morphological variations in the 2005-2006 flows. We also show that effusion rates were higher than in previously studied eruptions at this site and varied systematically along the length of the eruptive fissure. This is the first well-documented study in which variations in seafloor lava morphology can be directly related to a well documented ridge-crest eruption where effusion rate varied significantly.
Morphological feature extraction for the classification of digital images of cancerous tissues.
Thiran, J P; Macq, B
1996-10-01
This paper presents a new method for automatic recognition of cancerous tissues from an image of a microscopic section. Based on the shape and the size analysis of the observed cells, this method provides the physician with nonsubjective numerical values for four criteria of malignancy. This automatic approach is based on mathematical morphology, and more specifically on the use of Geodesy. This technique is used first to remove the background noise from the image and then to operate a segmentation of the nuclei of the cells and an analysis of their shape, their size, and their texture. From the values of the extracted criteria, an automatic classification of the image (cancerous or not) is finally operated.
Greater perceptual sensitivity to happy facial expression.
Maher, Stephen; Ekstrom, Tor; Chen, Yue
2014-01-01
Perception of subtle facial expressions is essential for social functioning; yet it is unclear if human perceptual sensitivities differ in detecting varying types of facial emotions. Evidence diverges as to whether salient negative versus positive emotions (such as sadness versus happiness) are preferentially processed. Here, we measured perceptual thresholds for the detection of four types of emotion in faces--happiness, fear, anger, and sadness--using psychophysical methods. We also evaluated the association of the perceptual performances with facial morphological changes between neutral and respective emotion types. Human observers were highly sensitive to happiness compared with the other emotional expressions. Further, this heightened perceptual sensitivity to happy expressions can be attributed largely to the emotion-induced morphological change of a particular facial feature (end-lip raise).
Dynamics in the Chromosphere Imaged at Four Second Cadence
NASA Astrophysics Data System (ADS)
Schmit, D.; De Pontieu, B.
2017-12-01
In this work we present analysis of rapid intensity fluctuations that are observed in the chromosphere and transition region using the slit-jaw datasets of IRIS and CLASP. While chromospheric oscillations have been a topic of interest for 30 years, the instrumentation to image those dynamics at high-cadence has only recently been developed. We use filtergraph data from 1215A, 2800A, and 1400A to examine the occurrence rate and morphology of rapid intensity fluctuations in different magnetic environments. There are indications of rapidly propagating disturbances with phase speeds greater than 100 km/s in all passbands although the morphology of the features differs significantly between passbands. The relationship between intensity fluctuations, spicules, and waves is discussed.
Morphological Features in Children with Autism Spectrum Disorders: A Matched Case-Control Study
ERIC Educational Resources Information Center
Ozgen, Heval; Hellemann, Gerhard S.; Stellato, Rebecca K.; Lahuis, Bertine; van Daalen, Emma; Staal, Wouter G.; Rozendal, Marije; Hennekam, Raoul C.; Beemer, Frits A.; van Engeland, Herman
2011-01-01
This study was designed to examine morphological features in a large group of children with autism spectrum disorder versus normal controls. Amongst 421 patients and 1,007 controls, 224 matched pairs were created. Prevalence rates and odds ratios were analyzed by conditional regression analysis, McNemar test or paired t-test matched pairs.…
Morphologic Analysis of Lunar Craters in the Simple-to-Complex Transition
NASA Astrophysics Data System (ADS)
Chandnani, M.; Herrick, R. R.; Kramer, G. Y.
2015-12-01
The diameter range of 15 km to 20 km on the Moon is within the transition from simple to complex impact craters. We examined 207 well preserved craters in this diameter range distributed across the moon using high resolution Lunar Reconnaissance Orbiter Camera Wide Angle Camera Mosaic (WAC) and Narrow Angle Camera (NAC) data. A map of the distribution of the 207 craters on the Moon using the global LROC WAC mosaic has been attahced with the abstract. By examining craters of similar diameter, impact energy is nearly constant, so differences in shape and morphology must be due to either target (e.g., porosity, density, coherence, layering) or impactor (e.g., velocity, density) properties. On the basis of the crater morphology, topographic profiles and depth-diameter ratio, the craters were classified into simple, craters with slumped walls, craters with both slumping and terracing, those containing a central uplift only, those with a central uplift and slumping, and the craters with a central uplift accompanied by both slumping and terracing, as shown in the image. It was observed that simple craters and craters with slumped walls occur predominately on the lunar highlands. The majority of the craters with terraced walls and all classes of central uplifts were observed predominately on the mare. In short, in this size range craters in the highlands were generally simple craters with occasionally some slumped material in the center, and the more developed features (terracing, central peak) were associated with mare craters. This is somewhat counterintuitive, as we expect the highlands to be generally weaker and less consolidated than the mare. We hypothesize that the presence of rheologic layering in the mare may be the cause of the more complex features that we observe. Relatively weak layers in the mare could develop through regolith formation between individual flows, or perhaps by variations within or between the flows themselves.
Spann, Marisa N; Bansal, Ravi; Rosen, Tove S; Peterson, Bradley S
2014-09-01
Knowledge of the role of brain maturation in the development of cognitive abilities derives primarily from studies of school-age children to adults. Little is known about the morphological features of the neonatal brain that support the subsequent development of abilities in early childhood, when maturation of the brain and these abilities are the most dynamic. The goal of our study was to determine whether brain morphology during the neonatal period supports early cognitive development through 2 years of age. We correlated morphological features of the cerebral surface assessed using deformation-based measures (surface distances) of high-resolution MRI scans for 33 healthy neonates, scanned between the first to sixth week of postmenstrual life, with subsequent measures of their motor, language, and cognitive abilities at ages 6, 12, 18, and 24 months. We found that morphological features of the cerebral surface of the frontal, mesial prefrontal, temporal, and occipital regions correlated with subsequent motor scores, posterior parietal regions correlated with subsequent language scores, and temporal and occipital regions correlated with subsequent cognitive scores. Measures of the anterior and middle portions of the cingulate gyrus correlated with scores across all three domains of ability. Most of the significant findings were inverse correlations located bilaterally in the brain. The inverse correlations may suggest either that a more protracted morphological maturation or smaller local volumes of neonatal brain tissue supports better performance on measures of subsequent motor, language, and cognitive abilities throughout the first 2 years of postnatal life. The correlations of morphological measures of the cingulate with measures of performance across all domains of ability suggest that the cingulate supports a broad range of skills in infancy and early childhood, similar to its functions in older children and adults. Copyright © 2014 Wiley Periodicals, Inc.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Wang, Y.; Ali, G.N.; Mikhov, M.K.
2005-01-01
Defects in SiC degrade the electrical properties and yield of devices made from this material. This article examines morphological defects in 4H-SiC and defects visible in electron beam-induced current (EBIC) images and their effects on the electrical characteristics of Schottky diodes. Optical Nomarski microscopy and atomic force microscopy were used to observe the morphological defects, which are classified into 26 types based on appearance alone. Forward and reverse current-voltage characteristics were used to extract barrier heights, ideality factors, and breakdown voltages. Barrier heights decrease about linearly with increasing ideality factor, which is explained by discrete patches of low barrier heightmore » within the main contact. Barrier height, ideality, and breakdown voltage all degrade with increasing device diameter, suggesting that discrete defects are responsible. Electroluminescence was observed under reverse bias from microplasmas associated with defects containing micropipes. EBIC measurements reveal several types of features corresponding to recombination centers. The density of dark spots observed by EBIC correlates strongly with ideality factor and barrier height. Most morphological defects do not affect the reverse characteristics when no micropipes are present, but lower the barrier height and worsen the ideality factor. However, certain multiple-tailed defects, irregularly shaped defects and triangular defects with 3C inclusions substantially degrade both breakdown voltage and barrier height, and account for most of the bad devices that do not contain micropipes. Micropipes in these wafers are also frequently found to be of Type II, which do not run parallel to the c axis.« less
DOE Office of Scientific and Technical Information (OSTI.GOV)
Wang,Y.; Ali, G.; Mikhov, M.
2005-01-01
Defects in SiC degrade the electrical properties and yield of devices made from this material. This article examines morphological defects in 4H-SiC and defects visible in electron beam-induced current (EBIC) images and their effects on the electrical characteristics of Schottky diodes. Optical Nomarski microscopy and atomic force microscopy were used to observe the morphological defects, which are classified into 26 types based on appearance alone. Forward and reverse current-voltage characteristics were used to extract barrier heights, ideality factors, and breakdown voltages. Barrier heights decrease about linearly with increasing ideality factor, which is explained by discrete patches of low barrier heightmore » within the main contact. Barrier height, ideality, and breakdown voltage all degrade with increasing device diameter, suggesting that discrete defects are responsible. Electroluminescence was observed under reverse bias from microplasmas associated with defects containing micropipes. EBIC measurements reveal several types of features corresponding to recombination centers. The density of dark spots observed by EBIC correlates strongly with ideality factor and barrier height. Most morphological defects do not affect the reverse characteristics when no micropipes are present, but lower the barrier height and worsen the ideality factor. However, certain multiple-tailed defects, irregularly shaped defects and triangular defects with 3C inclusions substantially degrade both breakdown voltage and barrier height, and account for most of the bad devices that do not contain micropipes. Micropipes in these wafers are also frequently found to be of Type II, which do not run parallel to the c axis.« less
NASA Astrophysics Data System (ADS)
Karson, J. A.; Hazlett, R. W.; Wysocki, R.; Bromfield, M. E.; Browne, N. C.; Davis, N. C.; Pelland, C. G.; Rowan, W. L.; Warner, K. A.
2014-12-01
Undergraduate students in the Keck Geology Consortium Lava Project participated in a month-long investigation of features of basaltic lava flows from two very different perspectives. The first half of the project focused on field relations in basaltic lava flows from the 1984 Krafla Fires eruption in northern Iceland. Students gained valuable experience in the collection of observations and samples in the field leading to hypotheses for the formation of selected features related to lava flow dynamics. Studies focused on a wide range of features including: morphology and heat loss in lava tubes (pyroducts), growth and collapse of lava ponds and overflow deposits, textural changes of lava falls (flow over steep steps), spaced spatter cones from flows over wet ground, and anisotropy of magnetic susceptibility related to flow kinematics. In the second half of the program students designed, helped execute, documented, and analyzed features similar to those they studied in the field with large-scale (50-250 kg) basaltic lava flows created in the Syracuse University Lava Project (http://lavaproject.syr.edu). Data collected included video from multiple perspectives, infrared thermal (FLIR) images, still images, detailed measurements of flow dimensions and rates, and samples for textural and magnetic analyses. Experimental lava flow features provided critical tests of hypotheses generated in the field and a refined understanding of the behavior and final morphology of basaltic lava flows. The linked field and experimental studies formed the basis for year-long independent research projects under the supervision of their faculty mentors, leading to senior theses at the students' respective institutions.
Initial Observations of Lunar Impact Melts and Ejecta Flows with the Mini-RF Radar
NASA Technical Reports Server (NTRS)
Carter, Lynn M.; Neish, Catherine D.; Bussey, D. B. J.; Spudis, Paul D.; Patterson, G. Wesley; Cahill, Joshua T.; Raney, R. Keith
2011-01-01
The Mini-RF radar on the Lunar Reconnaissance Orbiter's spacecraft has revealed a great variety of crater ejecta flow and impact melt deposits, some of which were not observed in prior radar imaging. The craters Tycho and Glushko have long melt flows that exhibit variations in radar backscatter and circular polarization ratio along the flow. Comparison with optical imaging reveals that these changes are caused by features commonly seen in terrestrial lava flows, such as rafted plates, pressure ridges, and ponding. Small (less than 20 km) sized craters also show a large variety of features, including melt flows and ponds. Two craters have flow features that may be ejecta flows caused by entrained debris flowing across the surface rather than by melted rock. The circular polarization ratios (CPRs) of the impact melt flows are typically very high; even ponded areas have CPR values between 0.7-1.0. This high CPR suggests that deposits that appear smooth in optical imagery may be rough at centimeter- and decimeter- scales. In some places, ponds and flows are visible with no easily discernable source crater. These melt deposits may have come from oblique impacts that are capable of ejecting melted material farther downrange. They may also be associated with older, nearby craters that no longer have a radar-bright proximal ejecta blanket. The observed morphology of the lunar crater flows has implications for similar features observed on Venus. In particular, changes in backscatter along many of the ejecta flows are probably caused by features typical of lava flows.
Schmittbuhl, M; Le Minor, J M; Allenbach, B; Schaaf, A
1999-05-01
The description of the human orbital shape is principally qualitative in the classical literature, and characterised by adjectives such as circular, rectangular or quadrangular. In order to provide a precise quantification and interpretation of this shape, a study based on automatic image analysis and Fourier analysis was carried out on 45 human skulls (30 males, 15 females), and for comparison on 61 skulls of Gorilla gorilla (40 males, 21 females), and 34 skulls of Pan troglodytes (20 males, 14 females). Sexual dimorphism in the shape of the orbital opening was not demonstrated. Its dominant morphological features could be characterized by Fourier analysis; elliptical elongation and quadrangularity were dominant morphological features of the shape of the orbital opening in the three species. Elliptical elongation was more marked in humans and Pan, whereas quadrangularity was particularly emphasized in Gorilla. An intraspecific variability of the shape of the orbital opening existed in humans, Gorilla and Pan, and seemed close in the three species. Interspecific partition between humans, Gorilla and Pan was demonstrated despite the variability observed in the three species studied. Interspecific differences between Gorilla and the Pan-humans group were principally explained by the differences in quadrangularity, and by differences in orientation of triangularity and pentagonality. Differences in the shape of the orbital opening between humans and Pan were principally explained by differences in hexagonality, and by differences in orientation of quadrangularity. A closeness of shape between some humans and some individuals in Pan and, to a lesser degree, with some individuals in Gorilla was observed, demonstrating the existence of a morphological continuum of the shape of the orbital opening in hominoids.
Large Impact Features on Europa: Results of the Galileo Nominal Mission
NASA Technical Reports Server (NTRS)
Moore, Jeffrey M.; Asphaug, Erik; Sullivan, Robert J.; Klemaszewski, James E.; Bender, Kelly C.; Greeley, Ronald; Geissler, Paul E.; McEwen, Alfred S.; Turtle, Elizabeth P.; Phillips, Cynthia B.
1998-01-01
The Galileo Orbiter examined several impact features on Europa at considerably better resolution than was possible from Voyager. The new data allow us to describe the morphology and infer the geology of the largest impact features on Europa, which are probes into the crust. We observe two basic types of large impact features: (1) "classic" impact craters that grossly resemble well-preserved lunar craters of similar size but are more topographically subdued (e.g., Pwyll) and (2) very flat circular features that lack the basic topographic structures of impact craters such as raised rims, a central depression, or central peaks, and which largely owe their identification as impact features to the field of secondary craters radially sprayed about them (e.g., Callanish). Our interpretation is that the classic craters (all <30 km diameter) formed entirely within a solid target at least 5 to 10 km thick that exhibited brittle behavior on time scales of the impact events. Some of the classic craters have a more subdued topography than fresh craters of similar size on other icy bodies such as Ganymede and Callisto, probably due to the enhanced viscous relaxation produced by a steeper thermal gradient on Europa. Pedestal ejecta facies on Europa (and Ganymede) may be produced by the relief-flattening movement of plastically deforming but otherwise solid ice that was warm at the time of emplacement. Callanish and Tyre do not appear to be larger and even more viscously relaxed versions of the classic craters; rather they display totally different morphologies such as distinctive textures and a series of large concentric structural rings cutting impact-feature-related materials. Impact simulations suggest that the distinctive morphologies would not be produced by impact into a solid ice target, but may be explained by impact into an ice layer approximately 10 to 15 km thick overlying a low-viscosity material such as water. The very wide (near antipodal) separation of Callanish and Tyre imply that approximately 10-15 km may have been the global average thickness of the rigid crust of Europa when these impacts occurred. The absence of detectable craters superposed on the interior deposits of Callanish suggests that it is geologically young (< 10(exp 8) years). Hence, it seems likely that our preliminary conclusions about the subsurface structure of Europa apply to the current day.
Large Impact Features on Europa: Results of the Galileo Nominal Mission
Moore, Johnnie N.; Asphaug, E.; Sullivan, R.J.; Klemaszewski, J.E.; Bender, K.C.; Greeley, R.; Geissler, P.E.; McEwen, A.S.; Turtle, E.P.; Phillips, C.B.; Tufts, B.R.; Head, J. W.; Pappalardo, R.T.; Jones, K.B.; Chapman, C.R.; Belton, M.J.S.; Kirk, R.L.; Morrison, D.
1998-01-01
The Galileo Orbiter examined several impact features on Europa at considerably better resolution than was possible from Voyager. The new data allow us to describe the morphology and infer the geology of the largest impact features on Europa, which are probes into the crust. We observe two basic types of large impact features: (1) "classic" impact craters that grossly resemble well-preserved lunar craters of similar size but are more topographically subdued (e.g., Pwyll) and (2) very flat circular features that lack the basic topographic structures of impact craters such as raised rims, a central depression, or central peaks, and which largely owe their identification as impact features to the field of secondary craters radially sprayed about them (e.g., Callanish). Our interpretation is that the classic craters (all <30 km diameter) formed entirely within a solid target at least 5 to 10 km thick that exhibited brittle behavior on time scales of the impact events. Some of the classic craters have a more subdued topography than fresh craters of similar size on other icy bodies such as Ganymede and Callisto, probably due to the enhanced viscous relaxation produced by a steeper thermal gradient on Europa. Pedestal ejecta facies on Europa (and Ganymede) may be produced by the relief-flattening movement of plastically deforming but otherwise solid ice that was warm at the time of emplacement. Callanish and Tyre do not appear to be larger and even more viscously relaxed versions of the classic craters; rather they display totally different morphologies such as distinctive textures and a series of large concentric structural rings cutting impact-feature-related materials. Impact simulations suggest that the distinctive morphologies would not be produced by impact into a solid ice target, but may be explained by impact into an ice layer ~10 to 15 km thick overlying a low-viscosity material such as water. The very wide (near antipodal) separation of Callanish and Tyre imply that ~10-15 km may have been the global average thickness of the rigid crust of Europa when these impacts occurred. The absence of detectable craters superposed on the interior deposits of Callanish suggests that it is geologically young (<108years). Hence, it seems likely that our preliminary conclusions about the subsurface structure of Europa apply to the current day. ?? 1998 Academic Press.
Numerical Simulations of a Jovian Ribbon-like Feature
NASA Astrophysics Data System (ADS)
Morales-Juberias, R.; Simon-Miller, A. A.; Dowling, T. E.; Sayanagi, K. M.; Choi, D. S.
2013-12-01
HST observations show the presence of a Ribbon like feature in Jupiter's atmosphere at ≈ 30 degrees North. The presence of this feature seems to correlate with periods when the jet amplitude velocities are highest. Studies of motions can help to determine the nature of the feature. Its detailed structure will be studied using Hubble data at multiple wavelengths and it may be possible to reprocess the long global movies of the Voyager era to study motions at this latitude. Preliminary model results without forcing show that the morphology of the produced instabilities is dependent on the conditions of the background flow and static stability of the atmosphere. Different forcing terms will be used to study the variable nature of this feature. We use numerical simulations to investigate the instabilities produced by different kinds of forcing on the westward jet centered at ≈ 30 degrees North in Jupiter's atmosphere as well as in its two flanking eastward jets to the north and south. Our goal is to understand how the background flow and static stability of the atmosphere affect the ability of the model to reproduce the Ribbon-like cloud pattern observed in Hubble Space Telescope (HST) images of that latitude taken in support of the 2007 New Horizons Jupiter flyby.
Hydrocarbon lakes on Titan: Distribution and interaction with a porous regolith
Hayes, A.; Aharonson, O.; Callahan, P.; Elachi, C.; Gim, Y.; Kirk, R.; Lewis, K.; Lopes, R.; Lorenz, R.; Lunine, J.; Mitchell, Ken; Mitri, Giuseppe; Stofan, E.; Wall, S.
2008-01-01
Synthetic Aperture Radar (SAR) images of Titan's north polar region reveal quasi-circular to complex features which are interpreted to be liquid hydrocarbon lakes. We investigate methane transport in Titan's hydrologic cycle using the global distribution of lake features. As of May 2007, the SAR data set covers ???22% of the surface and indicates multiple lake morphologies which are correlated across the polar region. Lakes are limited to latitudes above 55??N and vary from <10 to more than 100,000 km2. The size and location of lakes provide constraints on parameters associated with subsurface transport. Using porous media properties inferred from Huygens probe observations, timescales for flow into and out of observed lakes are shown to be in the tens of years, similar to seasonal cycles. Derived timescales are compared to the time between collocated SAR observations in order to consider the role of subsurface transport in Titan's hydrologic cycle. Copyright 2008 by the American Geophysical Union.
NASA Astrophysics Data System (ADS)
Schawinski, Kevin; Zhang, Ce; Zhang, Hantian; Fowler, Lucas; Santhanam, Gokula Krishnan
2017-05-01
Observations of astrophysical objects such as galaxies are limited by various sources of random and systematic noise from the sky background, the optical system of the telescope and the detector used to record the data. Conventional deconvolution techniques are limited in their ability to recover features in imaging data by the Shannon-Nyquist sampling theorem. Here, we train a generative adversarial network (GAN) on a sample of 4550 images of nearby galaxies at 0.01 < z < 0.02 from the Sloan Digital Sky Survey and conduct 10× cross-validation to evaluate the results. We present a method using a GAN trained on galaxy images that can recover features from artificially degraded images with worse seeing and higher noise than the original with a performance that far exceeds simple deconvolution. The ability to better recover detailed features such as galaxy morphology from low signal to noise and low angular resolution imaging data significantly increases our ability to study existing data sets of astrophysical objects as well as future observations with observatories such as the Large Synoptic Sky Telescope (LSST) and the Hubble and James Webb space telescopes.
Hodžić, Adnan; Alić, Amer; Beck, Relja; Beck, Ana; Huber, Doroteja; Otranto, Domenico; Baneth, Gad; Duscher, Georg G
2018-05-01
Species of the genus Hepatozoon (Adeleorina: Hepatozoidae) are arthropod-transmitted protozoan parasites that infect a wide range of vertebrate hosts. In the present study, we describe a new species of Hepatozoon primarily infecting martens and propose the name Hepatozoon martis n. sp., based on its unique morphological, molecular and pathogenic features. The overall prevalence of infection with H. martis n. sp. assessed by PCR in European pine martens (Martes martes) from Bosnia and Herzegovina and stone martens (Martes foina) from Croatia was 100% and 64%, respectively. Gamonts were found in neutrophils and monocytes, and various developmental stages were described in tissue cross-sections. Hepatozoon martis n. sp. shows a high predilection for muscle tissue, and the heart was the most frequently affected organ among the tissues tested by histopathology. Microscopically, pyogranulomatous lesions associated with the presence of the parasitic forms were observed in the cardiac and skeletal muscles of all positive animals examined. Furthermore, the possible existence of alternative, non-vectorial routes of transmission is discussed. Copyright © 2018 Elsevier GmbH. All rights reserved.
Impression of plasma voltage on growth of α-V2O5 nanostructured thin films
NASA Astrophysics Data System (ADS)
Sharma, Rabindar Kumar; Kumar, Prabhat; Reddy, G. B.
2015-06-01
In this communication, we synthesized vanadium pentoxide (α-V2O5) nanostructured thin films (NSTs) accompanied with nanoflakes/ nanoplates on the Ni-coated glass substrates employing plasma assisted sublimation process (PASP) as a function of plasma voltage (Vp). The effect of plasma voltage on structural, morphological, compositional, and vibrational properties have been studied systematically. The structural analysis divulged that all films deposited at different Vp have pure orthorhombic phase, no impurity phase is detected under resolution limit of XRD and XPS. The morphological studies of samples is carried out by SEM, revealed that features as well as alignment of V2O5 NSTs is greatly monitored by Vp and the film possessing the best features is obtained at 2500volt. In addition, XPS results reveal that V5+ oxidation state is the most prominent state in sample V2, which represents better stoichiometric nature of film. The vibrational study of all samples is performed by FTIR and strongly support the XRD observations. All the results are in consonance with each other.
Choe, Seongjun; Lee, Dongmin; Park, Hansol; Jeon, Hyeong-Kyu; Lee, Youngsun; Kim, Eunju; Na, Ki-Jeong; Eom, Keeseon S.
2016-01-01
We describe 2 echinostome species recovered from an Eastern cattle egret, Bubulcus ibis coromandus, from Cheongju-si (city), Chungcheongbuk-do (province), Korea. Total 72 Pegosomum bubulcum specimens were recovered from the bile duct. They were 7,566×2,938 μm in average size and had 27 collar spines with vitelline extension from anterior 1/3 level of the esophagus to mid-level of the posterior testis as characteristic features. Total 9 specimens of Nephrostomum ramosum were recovered in the small intestines of the bird. They were ribbon-shaped, 11,378×2,124 μm in average size, and morphologically variable in some organs, i.e., the number of collar spines (47-50), the shape of ovary and testes, and the extension of vitelline follicles. These morphological variations observed in a single host indicated that these features are not critical for the classification of Nephrostomum species and thus were reconsidered taxonomically as synonym of N. ramosum. This study is the first report documenting and describing both flukes and their associated genera in Korea. PMID:27658601
Choe, Seongjun; Lee, Dongmin; Park, Hansol; Jeon, Hyeong-Kyu; Lee, Youngsun; Kim, Eunju; Na, Ki-Jeong; Eom, Keeseon S
2016-08-01
We describe 2 echinostome species recovered from an Eastern cattle egret, Bubulcus ibis coromandus, from Cheongju-si (city), Chungcheongbuk-do (province), Korea. Total 72 Pegosomum bubulcum specimens were recovered from the bile duct. They were 7,566×2,938 μm in average size and had 27 collar spines with vitelline extension from anterior 1/3 level of the esophagus to mid-level of the posterior testis as characteristic features. Total 9 specimens of Nephrostomum ramosum were recovered in the small intestines of the bird. They were ribbon-shaped, 11,378×2,124 μm in average size, and morphologically variable in some organs, i.e., the number of collar spines (47-50), the shape of ovary and testes, and the extension of vitelline follicles. These morphological variations observed in a single host indicated that these features are not critical for the classification of Nephrostomum species and thus were reconsidered taxonomically as synonym of N. ramosum. This study is the first report documenting and describing both flukes and their associated genera in Korea.
NASA Astrophysics Data System (ADS)
Kim, Hyejeong; Kim, Hyeonjeong; Huh, Hyungkyu; Hwang, Hyung Ju; Lee, Sang Joon
2014-11-01
Plant leaves are generally known to have optimized morphological structure in response to environmental changes for efficient water usage. However, the advantageous features of plant leaves are not fully utilized in engineering fields yet, since the optimum design in internal structure of plant leaves is unclear. In this study, the tissue organization of the hydraulic pathways inside plant leaves was investigated. Water transport through double-layered porous hydrogel models analogous to mesophyll cells was experimentally observed. In addition, computational experiment and theoretical analysis were applied to the model systems to find the optimal design for efficient water transport. As a result, the models with lower porosity or with pores distributed widely in the structure exhibit efficient mass transport. Our theoretical prediction supports that structural features of plant leaves guarantee sufficient water supply as survival strategy. This study may provide a new framework for investigating the biophysical principles governing the morphological optimization of plant leaves and for designing microfluidic devices to enhance mass transport ability. This study was supported by the National Research Foundation of Korea and funded by the Korean government.
The VELA-X-Pulsar Wind Nebula Revisited with Four Years of Fermi Large Area Telescope Observations
NASA Technical Reports Server (NTRS)
Grondin, M. -H.; Romani, R. W.; Lemoine-Goumard, M.; Guillemot, L.; Harding, Alice K.; Reposeur, T.
2013-01-01
The Vela supernova remnant (SNR) is the closest SNR to Earth containing an active pulsar, the Vela pulsar (PSR B0833-45). This pulsar is an archetype of the middle-aged pulsar class and powers a bright pulsar wind nebula (PWN), Vela-X, spanning a region of 2deg × 3deg south of the pulsar and observed in the radio, X-ray, and very high energy ?-ray domains. The detection of the Vela-X PWN by the Fermi Large Area Telescope (LAT) was reported in the first year of the mission. Subsequently, we have reinvestigated this complex region and performed a detailed morphological and spectral analysis of this source using 4 yr of Fermi-LAT observations. This study lowers the threshold for morphological analysis of the nebula from 0.8 GeV to 0.3 GeV, allowing for the inspection of distinct energy bands by the LAT for the first time. We describe the recent results obtained on this PWN and discuss the origin of the newly detected spatial features.
The Vela-X pulsar wind nebula revisited with four years of Fermi Large Area Telescope observations
Grondin, M. -H.; Romani, R. W.; Lemoine-Goumard, M.; ...
2013-08-21
Here, the Vela supernova remnant (SNR) is the closest SNR to Earth containing an active pulsar, the Vela pulsar (PSR B0833–45). This pulsar is an archetype of the middle-aged pulsar class and powers a bright pulsar wind nebula (PWN), Vela-X, spanning a region of 2° × 3° south of the pulsar and observed in the radio, X-ray, and very high energy γ-ray domains. The detection of the Vela-X PWN by the Fermi Large Area Telescope (LAT) was reported in the first year of the mission. Subsequently, we have reinvestigated this complex region and performed a detailed morphological and spectral analysismore » of this source using 4 yr of Fermi-LAT observations. This study lowers the threshold for morphological analysis of the nebula from 0.8 GeV to 0.3 GeV, allowing for the inspection of distinct energy bands by the LAT for the first time. We describe the recent results obtained on this PWN and discuss the origin of the newly detected spatial features.« less
Silva, Vanessa J D; Ribeiro, Ester M; Luizi-Ponzo, Andrea P; Faria, Ana Paula G
2016-01-01
Pollen grain morphology of Bromeliaceae species collected in areas of the Atlantic Rainforest of southeastern Brazil was studied. The following species were analyzed: Aechmea bambusoides L.B.Sm. & Reitz, A. nudicaulis (L.) Griseb., A. ramosa Mart. ex Schult.f., Ananas bracteatus (Lindl.) Schult.f., Billbergia distachia (Vell.) Mez, B. euphemiae E. Morren, B. horrida Regel, B. zebrina (Herb.) Lindl., Portea petropolitana (Wawra) Mez, Pitcairnia flammea Lindl., Quesnelia indecora Mez, Tillandsia polystachia (L.) L., T. stricta Sol., T. gardneri Lindl., T. geminiflora Brongn. and Vriesea grandiflora Leme. Light and scanning electron microscopy were used and the species were grouped into three pollen types, organized according to aperture characteristics: Type I - pantoporate pollen grains observed in P. petropolitana, Type II - 2-porate pollen grains, observed in the genera Ananas, Aechmea and Quesnelia, and Type III - 1-colpate pollen grains, observed in the genera Billbergia, Pitcairnia, Tillandsia and Vriesea. Pollen data led to the construction of an identification key. The results showed that the species analyzed can be distinguished using mainly aperture features and exine ornamentation, and that these characteristics may assist in taxonomic studies of the family.
NASA Astrophysics Data System (ADS)
Williams, Richard; Measures, Richard; Hicks, Murray; Brasington, James
2017-04-01
Advances in geomatics technologies have transformed the monitoring of reach-scale (100-101 km) river morphodynamics. Hyperscale Digital Elevation Models (DEMs) can now be acquired at temporal intervals that are commensurate with the frequencies of high-flow events that force morphological change. The low vertical errors associated with such DEMs enable DEMs of Difference (DoDs) to be generated to quantify patterns of erosion and deposition, and derive sediment budgets using the morphological approach. In parallel with reach-scale observational advances, high-resolution, two-dimensional, physics-based numerical morphodynamic models are now computationally feasible for unsteady, reach-scale simulations. In light of this observational and predictive progress, there is a need to identify appropriate metrics that can be extracted from DEMs and DoDs to assess model performance. Nowhere is this more pertinent than in braided river environments, where numerous mobile channels that intertwine around mid-channel bars result in complex patterns of erosion and deposition, thus making model assessment particularly challenging. This paper identifies and evaluates a range of morphological and morphological-change metrics that can be used to assess predictions of braided river morphodynamics at the timescale of single storm events. A depth-averaged, mixed-grainsize Delft3D morphodynamic model was used to simulate morphological change during four discrete high-flow events, ranging from 91 to 403 m3s-1, along a 2.5 x 0.7 km reach of the braided, gravel-bed Rees River, New Zealand. Pre- and post-event topographic surveys, using a fusion of Terrestrial Laser Scanning and optical-empirical bathymetric mapping, were used to produce 0.5 m resolution DEMs and DoDs. The pre- and post-event DEMs for a moderate (227m3s-1) high-flow event were used to calibrate the model. DEMs and DoDs from the other three high-flow events were used for model assessment using two approaches. First, "morphological" metrics were applied to compare observed and predicted post-event DEMs. These metrics include measures of confluence and bifurcation node density, bar shape, braiding intensity, and topographic comparisons using a form of the Brier Skill Score and cumulative frequency distributions of rugosity. Second, "morphological change" metrics were used to compare observed and predicted morphological change. These metrics included the extent of the morphologically active area, pairwise comparisons of morphological change (using kappa and fuzzy kappa statistics), and comparisons between vertical morphological change magnitude and elevation distribution. Results indicate that those metrics that assess characteristic features of braiding, rather than making direct comparisons, are most useful for assessing reach-scale braided river morphodynamic models. Together, the metrics indicate that there was a general affinity between observed and predicted braided river morphodynamics, both during small and large magnitude high-flow events. These results thus demonstrate how high-resolution, reach-scale, natural experiment datasets can be used to assess the efficacy of morphological models in predicting realistic patterns of erosion and deposition. This lays the foundation for the development and assessment of decadal scale morphodynamic models and their use in adaptive river basin management.
Linguistic Pattern Analysis of Misspellings of Typically Developing Writers in Grades 1 to 9
Bahr, Ruth Huntley; Silliman, Elaine R.; Berninger, Virginia W.; Dow, Michael
2012-01-01
Purpose A mixed methods approach, evaluating triple word form theory, was used to describe linguistic patterns of misspellings. Method Spelling errors were taken from narrative and expository writing samples provided by 888 typically developing students in grades 1–9. Errors were coded by category (phonological, orthographic, and morphological) and specific linguistic feature affected. Grade level effects were analyzed with trend analysis. Qualitative analyses determined frequent error types and how use of specific linguistic features varied across grades. Results Phonological, orthographic, and morphological errors were noted across all grades, but orthographic errors predominated. Linear trends revealed developmental shifts in error proportions for the orthographic and morphological categories between grades 4–5. Similar error types were noted across age groups but the nature of linguistic feature error changed with age. Conclusions Triple word-form theory was supported. By grade 1, orthographic errors predominated and phonological and morphological error patterns were evident. Morphological errors increased in relative frequency in older students, probably due to a combination of word-formation issues and vocabulary growth. These patterns suggest that normal spelling development reflects non-linear growth and that it takes a long time to develop a robust orthographic lexicon that coordinates phonology, orthography, and morphology and supports word-specific, conventional spelling. PMID:22473834
Cell–material interactions on biphasic polyurethane matrix
Dicesare, Patrick; Fox, Wade M.; Hill, Michael J.; Krishnan, G. Rajesh; Yang, Shuying; Sarkar, Debanjan
2013-01-01
Cell–matrix interaction is a key regulator for controlling stem cell fate in regenerative tissue engineering. These interactions are induced and controlled by the nanoscale features of extracellular matrix and are mimicked on synthetic matrices to control cell structure and functions. Recent studies have shown that nanostructured matrices can modulate stem cell behavior and exert specific role in tissue regeneration. In this study, we have demonstrated that nanostructured phase morphology of synthetic matrix can control adhesion, proliferation, organization and migration of human mesenchymal stem cells (MSCs). Nanostructured biodegradable polyurethanes (PU) with segmental composition exhibit biphasic morphology at nanoscale dimensions and can control cellular features of MSCs. Biodegradable PU with polyester soft segment and hard segment composed of aliphatic diisocyanates and dipeptide chain extender were designed to examine the effect polyurethane phase morphology. By altering the polyurethane composition, morphological architecture of PU was modulated and its effect was examined on MSC. Results show that MSCs can sense the nanoscale morphology of biphasic polyurethane matrix to exhibit distinct cellular features and, thus, signifies the relevance of matrix phase morphology. The role of nanostructured phases of a synthetic matrix in controlling cell–matrix interaction provides important insights for regulation of cell behavior on synthetic matrix and, therefore, is an important tool for engineering tissue regeneration. PMID:23255285
NASA Astrophysics Data System (ADS)
Deng, Feiyue; Yang, Shaopu; Tang, Guiji; Hao, Rujiang; Zhang, Mingliang
2017-04-01
Wheel bearings are essential mechanical components of trains, and fault detection of the wheel bearing is of great significant to avoid economic loss and casualty effectively. However, considering the operating conditions, detection and extraction of the fault features hidden in the heavy noise of the vibration signal have become a challenging task. Therefore, a novel method called adaptive multi-scale AVG-Hat morphology filter (MF) is proposed to solve it. The morphology AVG-Hat operator not only can suppress the interference of the strong background noise greatly, but also enhance the ability of extracting fault features. The improved envelope spectrum sparsity (IESS), as a new evaluation index, is proposed to select the optimal filtering signal processed by the multi-scale AVG-Hat MF. It can present a comprehensive evaluation about the intensity of fault impulse to the background noise. The weighted coefficients of the different scale structural elements (SEs) in the multi-scale MF are adaptively determined by the particle swarm optimization (PSO) algorithm. The effectiveness of the method is validated by analyzing the real wheel bearing fault vibration signal (e.g. outer race fault, inner race fault and rolling element fault). The results show that the proposed method could improve the performance in the extraction of fault features effectively compared with the multi-scale combined morphological filter (CMF) and multi-scale morphology gradient filter (MGF) methods.
Hussain, Lal; Ahmed, Adeel; Saeed, Sharjil; Rathore, Saima; Awan, Imtiaz Ahmed; Shah, Saeed Arif; Majid, Abdul; Idris, Adnan; Awan, Anees Ahmed
2018-02-06
Prostate is a second leading causes of cancer deaths among men. Early detection of cancer can effectively reduce the rate of mortality caused by Prostate cancer. Due to high and multiresolution of MRIs from prostate cancer require a proper diagnostic systems and tools. In the past researchers developed Computer aided diagnosis (CAD) systems that help the radiologist to detect the abnormalities. In this research paper, we have employed novel Machine learning techniques such as Bayesian approach, Support vector machine (SVM) kernels: polynomial, radial base function (RBF) and Gaussian and Decision Tree for detecting prostate cancer. Moreover, different features extracting strategies are proposed to improve the detection performance. The features extracting strategies are based on texture, morphological, scale invariant feature transform (SIFT), and elliptic Fourier descriptors (EFDs) features. The performance was evaluated based on single as well as combination of features using Machine Learning Classification techniques. The Cross validation (Jack-knife k-fold) was performed and performance was evaluated in term of receiver operating curve (ROC) and specificity, sensitivity, Positive predictive value (PPV), negative predictive value (NPV), false positive rate (FPR). Based on single features extracting strategies, SVM Gaussian Kernel gives the highest accuracy of 98.34% with AUC of 0.999. While, using combination of features extracting strategies, SVM Gaussian kernel with texture + morphological, and EFDs + morphological features give the highest accuracy of 99.71% and AUC of 1.00.
Tripp, Erin A; Fatimah, Siti
2012-06-01
Anatomical and morphological features of Satanocrater were studied to test hypotheses of xeric adaptations in the genus, which is endemic to arid tropical Africa. These features, together with molecular data, were used to test the phylogenetic placement of Satanocrater within the large plant family Acanthaceae. We undertook a comparative study of four species of Satanocrater. Carbon isotope ratios were generated to test a hypothesis of C(4) photosynthesis. Molecular data from chloroplast (trnG-trnS, trnG-trnR, psbA-trnH) and nuclear (Eif3E) loci were used to test the placement of Satanocrater within Acanthaceae. Anatomical features reflecting xeric adaptations of species of Satanocrater included a thick-walled epidermis, thick cuticle, abundant trichomes and glandular scales, stomata overarched by subsidiary cells, tightly packed mesophyll cells, and well-developed palisade parenchyma on both leaf surfaces. Although two species had enlarged bundle sheath cells, a feature often implicated in C(4) photosynthesis, isotope ratios indicated all species of Satanocrater use the C(3) pathway. Molecular data resolved Satanocrater within tribe Ruellieae with strong support. Within Ruellieae, our data suggest that pollen morphology of Satanocrater may represent an intermediate stage in a transition series. Anatomical and morphological features of Satanocrater reflect adaptation to xeric environments and add new information about the biology of xerophytes. Morphological and molecular data place Satanocrater in the tribe Ruellieae with confidence. This study adds to our capacity to test hypotheses of broad evolutionary and ecological interest in a diverse and important family of flowering plants.
Douaihy, Bouchra; Sobierajska, Karolina; Jasińska, Anna Katarzyna; Boratyńska, Krystyna; Ok, Tolga; Romo, Angel; Machon, Nathalie; Didukh, Yakiv; Bou Dagher-Kharrat, Magda; Boratyński, Adam
2012-01-01
Juniperus excelsa M.-Bieb. is a major forest element in the mountains of the eastern part of Mediterranean and sub-Mediterranean regions. This study comprises the first morphological investigation covering a large part of the geographical range of J. excelsa and aims to verify the congruency between the morphological results and molecular results of a previous study. We studied 14 populations sampled from Greece, Cyprus, Ukraine, Turkey and Lebanon, 11 of which have previously been investigated using molecular markers. Three hundred and ninety-four individuals of J. excelsa were examined using nine biometric features characterizing cones, seeds and shoots, and eight derived ratios. Statistical analyses were conducted in order to evaluate the intra- and inter-population morphological variability. The level of intra-population variability observed did not show any geographical trends. The total variation mostly depended on the ratios of cone diameter/seed width and seed width/seed length. The discrimination analysis, the Ward agglomeration method and barrier analysis results showed a separation of the sampled populations into three main clusters. These results confirmed, in part, the geographical differentiation revealed by molecular markers with a lower level of differentiation and a less clear geographical pattern. The most differentiated populations using both markers corresponded to old, isolated populations in the high altitudes of Lebanon (>2000 m). Moreover, a separation of the northern Turkish population from the southern Turkish populations was observed using both markers. Morphological variation together with genetic and biogeographic studies make an effective tool for detecting relict plant populations and also populations subjected to more intensive selection.
Tailoring the nanoscale morphology of HKUST-1 thin films via codeposition and seeded growth
Brower, Landon J; Gentry, Lauren K; Napier, Amanda L
2017-01-01
Integration of surface-anchored metal-organic frameworks (surMOFs) within hierarchical architectures is necessary for potential sensing, electronic, optical, or separation applications. It is important to understand the fundamentals of film formation for these surMOFs in order to develop strategies for their incorporation with nanoscale control over lateral and vertical dimensions. This research identified processing parameters to control the film morphology for surMOFs of HKUST-1 fabricated by codeposition and seeded deposition. Time and temperature were investigated to observe film formation, to control film thickness, and to tune morphology. Film thickness was investigated by ellipsometry, while film structure and film roughness were characterized by atomic force microscopy. Films formed via codeposition resulted in nanocrystallites anchored to the gold substrate. A dynamic process at the interface was observed with a low density of large particulates (above 100 nm) initially forming on the substrate; and over time these particulates were slowly replaced by the prevalence of smaller crystallites (ca. 10 nm) covering the substrate at a high density. Elevated temperature was found to expedite the growth process to obtain the full range of surface morphologies with reasonable processing times. Seed crystals formed by the codeposition method were stable and nucleated growth throughout a subsequent layer-by-layer deposition process. These seed crystals templated the final film structure and tailor the features in lateral and vertical directions. Using codeposition and seeded growth, different surface morphologies with controllable nanoscale dimensions can be designed and fabricated for integration of MOF systems directly into device architectures and sensor platforms. PMID:29181287
Tailoring the nanoscale morphology of HKUST-1 thin films via codeposition and seeded growth.
Brower, Landon J; Gentry, Lauren K; Napier, Amanda L; Anderson, Mary E
2017-01-01
Integration of surface-anchored metal-organic frameworks (surMOFs) within hierarchical architectures is necessary for potential sensing, electronic, optical, or separation applications. It is important to understand the fundamentals of film formation for these surMOFs in order to develop strategies for their incorporation with nanoscale control over lateral and vertical dimensions. This research identified processing parameters to control the film morphology for surMOFs of HKUST-1 fabricated by codeposition and seeded deposition. Time and temperature were investigated to observe film formation, to control film thickness, and to tune morphology. Film thickness was investigated by ellipsometry, while film structure and film roughness were characterized by atomic force microscopy. Films formed via codeposition resulted in nanocrystallites anchored to the gold substrate. A dynamic process at the interface was observed with a low density of large particulates (above 100 nm) initially forming on the substrate; and over time these particulates were slowly replaced by the prevalence of smaller crystallites (ca. 10 nm) covering the substrate at a high density. Elevated temperature was found to expedite the growth process to obtain the full range of surface morphologies with reasonable processing times. Seed crystals formed by the codeposition method were stable and nucleated growth throughout a subsequent layer-by-layer deposition process. These seed crystals templated the final film structure and tailor the features in lateral and vertical directions. Using codeposition and seeded growth, different surface morphologies with controllable nanoscale dimensions can be designed and fabricated for integration of MOF systems directly into device architectures and sensor platforms.
Developmental gene regulatory network architecture across 500 million years of echinoderm evolution
NASA Technical Reports Server (NTRS)
Hinman, Veronica F.; Nguyen, Albert T.; Cameron, R. Andrew; Davidson, Eric H.
2003-01-01
Evolutionary change in morphological features must depend on architectural reorganization of developmental gene regulatory networks (GRNs), just as true conservation of morphological features must imply retention of ancestral developmental GRN features. Key elements of the provisional GRN for embryonic endomesoderm development in the sea urchin are here compared with those operating in embryos of a distantly related echinoderm, a starfish. These animals diverged from their common ancestor 520-480 million years ago. Their endomesodermal fate maps are similar, except that sea urchins generate a skeletogenic cell lineage that produces a prominent skeleton lacking entirely in starfish larvae. A relevant set of regulatory genes was isolated from the starfish Asterina miniata, their expression patterns determined, and effects on the other genes of perturbing the expression of each were demonstrated. A three-gene feedback loop that is a fundamental feature of the sea urchin GRN for endoderm specification is found in almost identical form in the starfish: a detailed element of GRN architecture has been retained since the Cambrian Period in both echinoderm lineages. The significance of this retention is highlighted by the observation of numerous specific differences in the GRN connections as well. A regulatory gene used to drive skeletogenesis in the sea urchin is used entirely differently in the starfish, where it responds to endomesodermal inputs that do not affect it in the sea urchin embryo. Evolutionary changes in the GRNs since divergence are limited sharply to certain cis-regulatory elements, whereas others have persisted unaltered.
NASA Astrophysics Data System (ADS)
Burkhard, L. M.; Cameron, M. E.; Smith-Konter, B. R.; Seifert, F.; Pappalardo, R. T.; Collins, G. C.
2015-12-01
Ganymede's fractured surface reveals many large-scale, morphologically distinct regions of inferred distributed shear and strike-slip faulting that may be important to the structural development of its surface and in the transition from dark to light (grooved) materials. To better understand the role of strike-slip tectonism in shaping Ganymede's complex icy surface, we perform a detailed mapping of key examples of strike-slip morphologies (i.e., en echelon structures, strike-slip duplexes, laterally offset pre-existing features, and possible strained craters) from Galileo and Voyager images. We focus on complex structures associated with grooved terrain (e.g. Nun Sulcus, Dardanus Sulcus, Tiamat Sulcus, and Arbela Sulcus) and terrains transitional from dark to light terrain (e.g. the boundary between Nippur Sulcus and Marius Regio, including Byblus Sulcus and Philus Sulcus). Detailed structural interpretations suggest strong evidence of strike-slip faulting in some regions (i.e., Nun and Dardanus Sulcus); however, further investigation of additional strike-slip structures is required of less convincing regions (i.e., Byblus Sulcus). Where applicable, these results are synthesized into a global database representing an inferred sense of shear for many of Ganymede's fractures. Moreover, when combined with existing observations of extensional features, these results help to narrow down the range of possible principal stress directions that could have acted at the regional or global scale to produce grooved terrain on Ganymede.
Godfrey, Maurice; Raghunath, Michael; Cisler, Jason; Bevins, Charles L.; DePaepe, Anne; Di Rocco, Maja; Gregoritch, Jane; Imaizumi, Kiyoshi; Kaplan, Paige; Kuroki, Yoshikazu; Silberbach, Michael; Superti-Furga, Andrea; Van Thienen, Marie-Noëlle; Vetter, Ulrich; Steinmann, Beat
1995-01-01
The Marfan syndrome (MFS) is a connective tissue disorder manifested by variable and pleiotropic features in the skeletal, ocular, and cardiovascular systems. The average life span in MFS is about 35 years. A group with much more severe cardiovascular disease and a mean life span of approximately I year also exists. We refer to this latter group as “neonatal Marfan syndrome” (nMFS). Fibrillin defects are now known to be the cause of MFS and nMFS. Immunofluorescence studies were the first to demonstrate this association. Here we describe immunofluorescence studies in a series of 10 neonates and summarize their salient clinical features. In vitro accumulation of fibrillin reactive fibers was assayed using monoclonal antibodies to fibrillin in hyperconfluent fibroblast cultures. As was previously observed in MFS, fibroblast cultures from nMFS patients showed an apparent decrease in accumulation of immunostainable fibrillin. Significantly, however, the morphology of the immunostained fibrils in the nMFS cultures were abnormal and differed not only from control cultures, but also from those seen in cultures of MFS fibroblasts. The nMFS fibrils appeared short, fragmented, and frayed, characteristics that are not seen in MFS. Both the clinical and fibrillin morphology data provide evidence to suggest a useful subclassification of nMFS in the spectrum of MFS. ImagesFigure 1Figure 2 PMID:7778680
NASA Astrophysics Data System (ADS)
Bear, Ealeal; Soker, Noam
2018-07-01
We find that the remnant of supernova (SN) 1987A shares some morphological features with four supernova remnants (SNRs) that have signatures of shaping by jets, and from that we strengthen the claim that jets played a crucial role in the explosion of SN 1987A. Some of the morphological features appear also in planetary nebulae (PNe) where jets are observed. The clumpy ejecta brings us to support the claim that the jittering jets explosion mechanism can account for the structure of the remnant of SN 1987A, i.e. SNR 1987A. We conduct a preliminary attempt to quantify the fluctuations in the angular momentum of the mass that is accreted on to the newly born neutron star via an accretion disc or belt. The accretion disc/belt launches jets that explode core collapse supernovae (CCSNe). The relaxation time of the accretion disc/belt is comparable to the duration of a typicalfigu jet-launching episode in the jittering jets explosion mechanism, and hence the disc/belt has no time to relax. We suggest that this might explain the two unequal opposite jets that later lead to the unequal sides of the elongated structures in some SNRs of CCSNe. We reiterate our earlier call for a paradigm shift from a neutrino-driven explosion to a jet-driven explosion of CCSNe.
Chondroptosis in Alkaptonuric Cartilage
Millucci, Lia; Giorgetti, Giovanna; Viti, Cecilia; Ghezzi, Lorenzo; Gambassi, Silvia; Braconi, Daniela; Marzocchi, Barbara; Paffetti, Alessandro; Lupetti, Pietro; Bernardini, Giulia; Orlandini, Maurizio
2015-01-01
Alkaptonuria (AKU) is a rare genetic disease that affects the entire joint. Current standard of treatment is palliative and little is known about AKU physiopathology. Chondroptosis, a peculiar type of cell death in cartilage, has been so far reported to occur in osteoarthritis, a rheumatic disease that shares some features with AKU. In the present work, we wanted to assess if chondroptosis might also occur in AKU. Electron microscopy was used to detect the morphological changes of chondrocytes in damaged cartilage distinguishing apoptosis from its variant termed chondroptosis. We adopted histological observation together with Scanning Electron Microscopy and Transmission Electron Microscopy to evaluate morphological cell changes in AKU chondrocytes. Lipid peroxidation in AKU cartilage was detected by fluorescence microscopy. Using the above‐mentioned techniques, we performed a morphological analysis and assessed that AKU chondrocytes undergo phenotypic changes and lipid oxidation, resulting in a progressive loss of articular cartilage structure and function, showing typical features of chondroptosis. To the best of our knowledge, AKU is the second chronic pathology, following osteoarthritis, where chondroptosis has been documented. Our results indicate that Golgi complex plays an important role in the apoptotic process of AKU chondrocytes and suggest a contribution of chondroptosis in AKU pathogenesis. These findings also confirm a similarity between osteoarthritis and AKU. J. Cell. Physiol. 230: 1148–1157, 2015. © 2014 The Authors. Journal of Cellular Physiology Published by Wiley Periodicals, Inc. PMID:25336110
Ye, Wenwu; Wang, Yang; Shen, Danyu; Li, Delong; Pu, Tianhuizi; Jiang, Zide; Zhang, Zhengguang; Zheng, Xiaobo; Tyler, Brett M; Wang, Yuanchao
2016-07-01
On the basis of its downy mildew-like morphology, the litchi downy blight pathogen was previously named Peronophythora litchii. Recently, however, it was proposed to transfer this pathogen to Phytophthora clade 4. To better characterize this unusual oomycete species and important fruit pathogen, we obtained the genome sequence of Phytophthora litchii and compared it to those from other oomycete species. P. litchii has a small genome with tightly spaced genes. On the basis of a multilocus phylogenetic analysis, the placement of P. litchii in the genus Phytophthora is strongly supported. Effector proteins predicted included 245 RxLR, 30 necrosis-and-ethylene-inducing protein-like, and 14 crinkler proteins. The typical motifs, phylogenies, and activities of these effectors were typical for a Phytophthora species. However, like the genome features of the analyzed downy mildews, P. litchii exhibited a streamlined genome with a relatively small number of genes in both core and species-specific protein families. The low GC content and slight codon preferences of P. litchii sequences were similar to those of the analyzed downy mildews and a subset of Phytophthora species. Taken together, these observations suggest that P. litchii is a Phytophthora pathogen that is in the process of acquiring downy mildew-like genomic and morphological features. Thus P. litchii may provide a novel model for investigating morphological development and genomic adaptation in oomycete pathogens.
NASA Astrophysics Data System (ADS)
Bear, Ealeal; Soker, Noam
2018-04-01
We find that the remnant of supernova (SN) 1987A shares some morphological features with four supernova remnants (SNRs) that have signatures of shaping by jets, and from that we strengthen the claim that jets played a crucial role in the explosion of SN 1987A. Some of the morphological features appear also in planetary nebulae (PNe) where jets are observed. The clumpy ejecta bring us to support the claim that the jittering jets explosion mechanism can account for the structure of the remnant of SN 1987A, i.e., SNR 1987A. We conduct a preliminary attempt to quantify the fluctuations in the angular momentum of the mass that is accreted on to the newly born neutron star via an accretion disk or belt. The accretion disk/belt launches the jets that explode core collapse supernovae (CCSNe). The relaxation time of the accretion disk/belt is comparable to the duration of a typical jet-launching episode in the jittering jets explosion mechanism, and hence the disk/belt has no time to relax. We suggest that this might explain two unequal opposite jets that later lead to unequal sides of the elongated structures in some SNRs of CCSNe. We reiterate our earlier call for a paradigm shift from neutrino-driven explosion to a jet-driven explosion of CCSNe.
Vasconcelos, R.B.; Salles, L.P.; Silva, I. Oliveira e; Gulart, L.V.M.; Souza, D.K.; Torres, F.A.G.; Bocca, A.L.; Silva, A.A.M. Rosa e
2013-01-01
Follicle cultures reproduce in vitro the functional features observed in vivo. In a search for an ideal model, we cultured bovine antral follicle wall sections (FWS) in a serum-free defined medium (DM) known to induce 17β-estradiol (E2) production, and in a nondefined medium (NDM) containing serum. Follicles were sectioned and cultured in NDM or DM for 24 or 48 h. Morphological features were determined by light microscopy. Gene expression of steroidogenic enzymes and follicle-stimulating hormone (FSH) receptor were determined by RT-PCR; progesterone (P4) and E2 concentrations in the media were measured by radioimmunoassay. DM, but not NDM, maintained an FWS morphology in vitro that was similar to fresh tissue. DM also induced an increase in the expression of all steroidogenic enzymes, except FSH receptor, but NDM did not. In both DM and NDM, there was a gradual increase in P4 throughout the culture period; however, P4 concentration was significantly higher in NDM. In both media, E2 concentration was increased at 24 h, followed by a decrease at 48 h. The E2:P4 ratio was higher in DM than in NDM. These results suggest that DM maintains morphological structure, upregulates the expression of steroidogenic enzyme genes, and maintains steroid production with a high E2:P4 ratio in FWS cultures. PMID:23969977
D'Amore, G; Pacciani, E; Frederic, P; Caramella Crespi, V
2007-01-01
The present study describes human skeletal remains from Riparo della Rossa, a rock shelter in the Marche region (Central Italy). The remains consist of a cranial vault and a few non-articulated postcranial bones, possibly belonging to the same adult individual. As the cranial vault showed some morphological features that are unusual for a modern human (marked prominence of the supraorbital region, very prominent nasal bones and rather high thickness of the vault), an accurate anthropological analysis and quantification of the antiquity of the bones were required. The remains were dated with two different absolute dating methods, AMS (14)C and (235)U-(231)Pa non-destructive gamma-ray spectrometry (NDGRS), which produced discordant results: the uncalibrated (14)C dating produced 5690 +/- 80 BP for the cranial vault and 6110 +/- 80 BP for the clavicle; the NDGRS dating produced 10,000 +/- 3000 BP for the cranial vault. The sex discriminant morphological characters on the skull are not unequivocal, though the masculine ones appear more evident. The aims of the present paper are: to provide a morphological and metric description of the remains; to interpret their unusual morphological features; to attempt to attribute them to male or female sex and to one of the possible prehistoric cultural groups, according to dating results (Upper Palaeolithic, Mesolithic or Neolithic). The attribution was obtained by a Bayesian procedure taking into account the reliability of the combined information of morphological/metric features and absolute dating results. The results suggest that the Riparo della Rossa remains are best attributed to a male individual of the Neolithic age.
Zoroquiain, Pablo; Mayo-Goldberg, Erin; Alghamdi, Sarah; Alhumaid, Sulaiman; Perlmann, Eduardo; Barros, Paulo; Mayo, Nancy; Burnier, Miguel N
2016-12-01
The cutoff presented in the current classification of canine melanocytic lesions by Wilcock and Pfeiffer is based on the clinical outcome rather than morphological concepts. Classification of tumors based on morphology or molecular signatures is the key to identifying new therapies or prognostic factors. Therefore, the aim of this study was to analyze morphological findings in canine melanocytic lesions based on classic malignant morphologic principles of neoplasia and to compare these features with human uveal melanoma (HUM) samples. In total, 64 canine and 111 human morphologically malignant melanocytic lesions were classified into two groups (melanocytoma-like or classic melanoma) based on the presence or absence of M cells, respectively. Histopathological characteristics were compared between the two groups using the χ-test, t-test, and multivariate discriminant analysis. Among the 64 canine tumors, 28 (43.7%) were classic and 36 (56.3%) were melanocytoma-like melanomas. Smaller tumor size, a higher degree of pigmentation, and lower mitotic activity distinguished melanocytoma-like from classic tumors with an accuracy of 100% for melanocytoma-like lesions. From the human series, only one case showed melanocytoma-like features and had a low risk for metastasis characteristics. Canine uveal melanoma showed a morphological spectrum with features similar to the HUM counterpart (classic melanoma) and overlapped features between uveal melanoma and melanocytoma (melanocytoma-like melanoma). Recognition that the subgroup of melanocytoma-like melanoma may represent the missing link between benign and malignant lesions could help explain the progression of uveal melanoma in dogs; these findings can potentially be translated to HUM.
Bone morphology of the hind limbs in two caviomorph rodents.
de Araújo, F A P; Sesoko, N F; Rahal, S C; Teixeira, C R; Müller, T R; Machado, M R F
2013-04-01
In order to evaluate the hind limbs of caviomorph rodents a descriptive analysis of the Cuniculus paca (Linnaeus, 1766) and Hydrochoerus hydrochaeris (Linnaeus, 1766) was performed using anatomical specimens, radiography, computed tomography (CT) and full-coloured prototype models to generate bone anatomy data. The appendicular skeleton of the two largest rodents of Neotropical America was compared with the previously reported anatomical features of Rattus norvegicus (Berkenhout, 1769) and domestic Cavia porcellus (Linnaeus, 1758). The structures were analyzed macroscopically and particular findings of each species reported. Features including the presence of articular fibular projection and lunulae were observed in the stifle joint of all rodents. Imaging aided in anatomical description and, specifically in the identification of bone structures in Cuniculus paca and Hydrochoerus hydrochaeris. The imaging findings were correlated with the anatomical structures observed. The data may be used in future studies comparing these animals to other rodents and mammalian species. © 2012 Blackwell Verlag GmbH.
Functional analyses of the primate upper cervical vertebral column.
Nalley, Thierra K; Grider-Potter, Neysa
2017-06-01
Recent work has highlighted functional correlations between direct measures of head and neck posture and primate cervical bony morphology. Primates with more horizontal necks exhibit middle and lower cervical vertebral features that indicate increased mechanical advantage for deep nuchal musculature and mechanisms for column curvature formation and maintenance. How features of the C1 and C2 reflect quantified measures of posture have yet to be examined. This study incorporates bony morphology from the upper cervical levels from 20 extant primate species in order to investigate further how posture correlates with cervical vertebrae morphology. Results from phylogenetic generalized least-squares analyses indicate that few vertebral features exhibit a significant relationship with posture when accounting for differences in size. When size-adjusted traits were correlated with posture, vertebral variation had a stronger relationship with neck posture than head posture variables. Two C1 traits-relative posterior arch length and superior facet curvature-were correlated with neck posture variables. Relative posterior arch length exhibits a positive relationship with neck posture, while superior articular facet curvature demonstrates a negative relationship, such that as the neck becomes more horizontal, the greater the facet curvature. Four C2 features were also correlated with neck posture: relative pedicle and lamina lengths, relative superior facet orientation, and dens orientation. Relative pedicle and lamina lengths become craniocaudally longer as the neck becomes more horizontal. Relative C2 superior facet orientation and dens orientation exhibit negative correlations with posture, such that as the neck becomes more horizontal, the superior facet becomes more caudally inclined and the dens more dorsally inclined. These results produce a similar functional signal observed in the middle and lower cervical spine. Modeling the cervical vertebrae of more pronograde taxa within a sigmoidal spinal column model is further discussed and may prove useful in refining and testing future hypotheses of primate cervical mechanics. Copyright © 2017 Elsevier Ltd. All rights reserved.
NASA Astrophysics Data System (ADS)
Marra, Wouter A.; Braat, Lisanne; Baar, Anne W.; Kleinhans, Maarten G.
2014-04-01
Remains of fluvial valleys on Mars reveal the former presence of water on the surface. However, the source of water and the hydrological setting is not always clear, especially in types of valleys that are rare on Earth and where we have limited knowledge of the processes involved. We investigated three hydrological scenarios for valley formation on Mars: hydrostatic groundwater seepage, release of pressurized groundwater and crater-lake overflow. Using physical modeling in laboratory experiments and numerical hydrological modeling we quantitatively studied the morphological development and processes involved in channel formation that result from these different sources of water in unconsolidated sediment. Our results show that valleys emerging from seeping groundwater by headward erosion form relatively slowly as fluvial transport takes place in a channel much smaller than the valley. Pressurized groundwater release forms a characteristic source area at the channel head by fluidization processes. This head consist of a pit in case of superlithostatic pressure and may feature small radial channels and collapse features. Valleys emerging from a crater-lake overflow event develop quickly in a run-away process of rim erosion and discharge increase. The valley head at the crater outflow point has a converging fan shape, and the rapid incision of the rim leaves terraces and collapse features. Morphological elements observed in the experiments can help in identifying the formative processes on Mars, when considerations of experimental scaling and lithological characteristics of the martian surface are taken into account. These morphological features might reveal the associated hydrological settings and formative timescales of a valley. An estimate of formative timescale from sediment transport is best based on the final channel dimensions for groundwater seepage valleys and on the valley dimensions for pressurized groundwater release and crater-lake overflow valleys. Our experiments show that different sources of water form valleys of similar size in quite different timescales.
Modeling snow-crystal growth: a three-dimensional mesoscopic approach.
Gravner, Janko; Griffeath, David
2009-01-01
We introduce a three-dimensional, computationally feasible, mesoscopic model for snow-crystal growth, based on diffusion of vapor, anisotropic attachment, and a boundary layer. Several case studies are presented that faithfully replicate most observed snow-crystal morphology, an unusual achievement for a mathematical model. In particular, many of the most striking physical specimens feature both facets and branches, and our model provides an explanation for this phenomenon. We also duplicate many other observed traits, including ridges, ribs, sandwich plates, and hollow columns, as well as various dynamic instabilities. The concordance of observed phenomena suggests that the ingredients in our model are the most important ones in the development of physical snow crystals.
NASA Technical Reports Server (NTRS)
Holt, J. W.; Blankenship, D. D.; Peters, M. E.; Kempf, S. D.; Morse, D. L.; Williams, B. J.
2003-01-01
The recent identification of features on Mars exhibiting morphologies consistent with ice/rock mixtures, near-surface ice bodies and near-surface liquid water [1,2], and the importance of such features to the search for water on Mars, highlights the need for appropriate terrestrial analogs in order to prepare for upcoming radar missions targeting these and other water-related features. Climatic, hydrological, and geological conditions in the McMurdo Dry Valleys of Antarctica are analogous in many ways to those on Mars, and a number of ice-related features in the Dry Valleys may have direct morphologic and compositional counterparts on Mars.
Geomorphology and Sediment Stability of a Segment of the U.S. Continental Slope off New Jersey.
Robb, J M; Hampson, J C; Twichell, D C
1981-02-27
The morphology of complex deposits of Pleistocene sediments covering the upper continental slope between Lindenkohl Canyon and South Toms Canyon results from both depositional and erosional processes. Small slump or slide features were detected primarily on the flanks of canyons or valleys and were observed to occur only within Pleistocene-aged sediments. Eocene to Miocene sediments are exposed over much of the mid- and lower slope in this area.
Molecular biomarkers for progression of intraductal papillary mucinous neoplasm of the pancreas.
Kuboki, Yuko; Shimizu, Kyoko; Hatori, Takashi; Yamamoto, Masakazu; Shibata, Noriyuki; Shiratori, Keiko; Furukawa, Toru
2015-03-01
We aimed to identify molecular biomarkers for assessing the progression of intraductal papillary mucinous neoplasm of the pancreas (IPMN). We retrospectively investigated molecular aberrations and their associations with clinicopathological features in 172 IPMNs. GNAS and KRAS mutations were detected in 48% and 56% of IPMNs, respectively. No mutations of EGFR, PIK3CA GNAO1, GNAQ, or GNAI2 were observed. Significant associations were observed between IPMN morphological types and GNAS mutations, KRAS mutations, the expression of phosphorylated MAPK (pMAPK), AKT, and phosphorylated AKT (pAKT), nuclear accumulation of β-catenin, SMAD4 loss, and TP53 overexpression; histological grades and the expression of EGFR, pMAPK, AKT, and pAKT, the nuclear β-catenin, SMAD4 loss, and TP53 overexpression; invasive phenotypes and KRAS mutations, the nuclear β-catenin, and SMAD4 loss; and prognosis and SMAD4 loss and TP53 overexpression. Multivariate analysis to compare prognostic impacts of multiple molecular features revealed that TP53 overexpression was an independent prognostic factor (P = 0.030; hazard ratio, 5.533). These results indicate that mutations in GNAS and KRAS, the expression of EGFR and pMAPK, the nuclear β-catenin, SMAD4 loss, and TP53 overexpression may be relevant for assessing the clinical course of IPMN, including its progression into different morphological types, invasion, and prognosis.
Geologic Stratigraphy, Delta Morphology, and Regional History of Hypanis Delta, Mars
NASA Astrophysics Data System (ADS)
Adler, J.; Bell, J. F., III; Warner, N. H.; Fawdon, P.; Gupta, S.; Sefton-Nash, E.; Grindrod, P. M.; Davis, J.
2016-12-01
Hypanis is a large Noachian aged fan-shaped deposit that has been interpreted by many as being a delta in Xanthe Terra along the dichotomy boundary. The position of the putative delta at the edge of an open basin and its preserved morphology including potential access to bottomset beds had made Hypanis a compelling candidate future landing site for Mars 2020 and ExoMars. Its topographic location, without a clear local closed basin, may even imply a large northern sea. We further previous studies of Hypanis delta by 1) analyzing the stratigraphy of floor plains materials surrounding ancient deltaic deposits 2) conducting a survey of sedimentary bed strike and dip distribution, and 3) presenting a regional history model that includes a diversity of volcanic, sedimentary, tectonic, and impact processes identified. Hypanis delta has previously been dated at 3.8 Ga based on crater counts in the Hypanis Valles catchment and previous fluvial system analysis estimates 150 km3 of sediment deposited. We utilize 17 HiRISE and 8 CTX DTMs to measure fluvial and stratigraphic quantities, a CTX 5 m/pixel mosaic basemap (USGS), and THEMIS day/night IR images. We determine map unit stratigraphy (relative ages) from superposition and cross cutting relationships supported in our 3D models. We discuss periods of subaqueous sedimentation, fluvial migration, volcanic resurfacing, and multiple periods of erosion throughout the study region to explain the observed morphologies and inferred geologic timeline. Additional work focuses on newly discovered tectonic features prevalent in the low-lying plains unit. These 2 m wide linear features suggest orthogonal jointing and relatively recent faulting. We assess whether these features could be related to the cooling of Hesperian lava plains or isostatic uplift from a removed glacier or eroded landmass.
Yin, Long-Lin; Song, Bin; Guan, Ying; Li, Ying-Chun; Chen, Guang-Wen; Zhao, Li-Ming; Lai, Li
2014-09-01
To investigate MRI features and associated histological and pathological changes of hilar and extrahepatic big bile duct cholangiocarcinoma with different morphological sub-types, and its value in differentiating between nodular cholangiocarcinoma (NCC) and intraductal growing cholangiocarcinoma (IDCC). Imaging data of 152 patients with pathologically confirmed hilar and extrahepatic big bile duct cholangiocarcinoma were reviewed, which included 86 periductal infiltrating cholangiocarcinoma (PDCC), 55 NCC, and 11 IDCC. Imaging features of the three morphological sub-types were compared. Each of the subtypes demonstrated its unique imaging features. Significant differences (P < 0.05) were found between NCC and IDCC in tumor shape, dynamic enhanced pattern, enhancement degree during equilibrium phase, multiplicity or singleness of tumor, changes in wall and lumen of bile duct at the tumor-bearing segment, dilatation of tumor upstream or downstream bile duct, and invasion of adjacent organs. Imaging features reveal tumor growth patterns of hilar and extrahepatic big bile duct cholangiocarcinoma. MRI united-sequences examination can accurately describe those imaging features for differentiation diagnosis.
Many Specialists for Suppressing Cortical Excitation
Burkhalter, Andreas
2008-01-01
Cortical computations are critically dependent on GABA-releasing neurons for dynamically balancing excitation with inhibition that is proportional to the overall level of activity. Although it is widely accepted that there are multiple types of interneurons, defining their identities based on qualitative descriptions of morphological, molecular and physiological features has failed to produce a universally accepted ‘parts list’, which is needed to understand the roles that interneurons play in cortical processing. A list of features has been published by the Petilla Interneurons Nomenclature Group, which represents an important step toward an unbiased classification of interneurons. To this end some essential features have recently been studied quantitatively and their association was examined using multidimensional cluster analyses. These studies revealed at least 3 distinct electrophysiological, 6 morphological and 15 molecular phenotypes. This is a conservative estimate of the number of interneuron types, which almost certainly will be revised as more quantitative studies will be performed and similarities will be defined objectively. It is clear that interneurons are organized with physiological attributes representing the most general, molecular characteristics the most detailed and morphological features occupying the middle ground. By themselves, none of these features are sufficient to define classes of interneurons. The challenge will be to determine which features belong together and how cell type-specific feature combinations are genetically specified. PMID:19225588
Significance of MPEG-7 textural features for improved mass detection in mammography.
Eltonsy, Nevine H; Tourassi, Georgia D; Fadeev, Aleksey; Elmaghraby, Adel S
2006-01-01
The purpose of the study is to investigate the significance of MPEG-7 textural features for improving the detection of masses in screening mammograms. The detection scheme was originally based on morphological directional neighborhood features extracted from mammographic regions of interest (ROIs). Receiver Operating Characteristics (ROC) was performed to evaluate the performance of each set of features independently and merged into a back-propagation artificial neural network (BPANN) using the leave-one-out sampling scheme (LOOSS). The study was based on a database of 668 mammographic ROIs (340 depicting cancer regions and 328 depicting normal parenchyma). Overall, the ROC area index of the BPANN using the directional morphological features was Az=0.85+/-0.01. The MPEG-7 edge histogram descriptor-based BPNN showed an ROC area index of Az=0.71+/-0.01 while homogeneous textural descriptors using 30 and 120 channels helped the BPNN achieve similar ROC area indexes of Az=0.882+/-0.02 and Az=0.877+/-0.01 respectively. After merging the MPEG-7 homogeneous textural features with the directional neighborhood features the performance of the BPANN increased providing an ROC area index of Az=0.91+/-0.01. MPEG-7 homogeneous textural descriptor significantly improved the morphology-based detection scheme.
Rosati, Giovanna; Modeo, Letizia; Melai, Michele; Petroni, Giulio; Verni, Franco
2004-01-01
This study represents the first extended report on a species of the ciliate genus Peritromus, widespread in marine biotopes, characterized by a dorso-ventral differentiation peculiar among Heterotrichea. Morphological observations (live, stained, scanning, and transmission electron microscope) were combined with behavioral and molecular data. On the basis of the whole body of observations, the species was recognized as Peritromus kahli. Scanning and transmission electron microscopy have revealed a number of features such as peculiar chalice-like structures external to the dorsal surface, two types of extrusomes, and differences between dorsal and ventral somatic ciliature. The almost complete SSrDNA gene sequence was also determined. A molecular phylogenetic analysis indicated that Peritromus diverged early from other members of the Class Heterotrichea. The dorso-ventral differentiation that certainly influences the behavior of P. kahli (e.g. preference for crawling and thigmotaxis) may have been selected as an adaptation to the constraints of the interstitial habitat.
NASA Astrophysics Data System (ADS)
Orlando, S.; Miceli, M.; Petruk, O.
2017-02-01
Supernova remnants (SNRs) are diffuse extended sources characterized by a complex morphology and a non-uniform distribution of ejecta. Such a morphology reflects pristine structures and features of the progenitor supernova (SN) and the early interaction of the SN blast wave with the inhomogeneous circumstellar medium (CSM). Deciphering the observations of SNRs might open the possibility to investigate the physical properties of both the interacting ejecta and the shocked CSM. This requires accurate numerical models which describe the evolution from the SN explosion to the remnant development and which connect the emission properties of the remnants to the progenitor SNe. Here we show how multi-dimensional SN-SNR hydrodynamic models have been very effective in deciphering observations of SNR Cassiopeia A and SN 1987A, thus unveiling the structure of ejecta in the immediate aftermath of the SN explosion and constraining the 3D pre-supernova structure and geometry of the environment surrounding the progenitor SN.
Patterns of differences in brain morphology in humans as compared to extant apes.
Aldridge, Kristina
2011-01-01
Although human evolution is characterized by a vast increase in brain size, it is not clear whether or not certain regions of the brain are enlarged disproportionately in humans, or how this enlargement relates to differences in overall neural morphology. The aim of this study is to determine whether or not there are specific suites of features that distinguish the morphology of the human brain from that of apes. The study sample consists of whole brain, in vivo magnetic resonance images (MRIs) of anatomically modern humans (Homo sapiens sapiens) and five ape species (gibbons, orangutans, gorillas, chimpanzees, bonobos). Twenty-nine 3D landmarks, including surface and internal features of the brain were located on 3D MRI reconstructions of each individual using MEASURE software. Landmark coordinate data were scaled for differences in size and analyzed using Euclidean Distance Matrix Analysis (EDMA) to statistically compare the brains of each non-human ape species to the human sample. Results of analyses show both a pattern of brain morphology that is consistently different between all apes and humans, as well as patterns that differ among species. Further, both the consistent and species-specific patterns include cortical and subcortical features. The pattern that remains consistent across species indicates a morphological reorganization of 1) relationships between cortical and subcortical frontal structures, 2) expansion of the temporal lobe and location of the amygdala, and 3) expansion of the anterior parietal region. Additionally, results demonstrate that, although there is a pattern of morphology that uniquely defines the human brain, there are also patterns that uniquely differentiate human morphology from the morphology of each non-human ape species, indicating that reorganization of neural morphology occurred at the evolutionary divergence of each of these groups. Copyright © 2010 Elsevier Ltd. All rights reserved.
Patterns of differences in brain morphology in humans as compared to extant apes
Aldridge, Kristina
2010-01-01
Although human evolution is characterized by a vast increase in brain size, it is not clear whether or not certain regions of the brain are enlarged disproportionately in humans, or how this enlargement relates to differences in overall neural morphology. The aim of this study is to determine whether or not there are specific suites of features that distinguish the morphology of the human brain from that of apes. The study sample consists of whole brain, in vivo magnetic resonance images (MRIs) of anatomically modern humans (Homo sapiens sapiens) and five ape species (gibbons, orangutans, gorillas, chimpanzees, bonobos). Twenty-nine 3D landmarks, including surface and internal features of the brain were located on 3D MRI reconstructions of each individual using MEASURE software. Landmark coordinate data were scaled for differences in size and analyzed using Euclidean Distance Matrix Analysis (EDMA) to statistically compare the brains of each non-human ape species to the human sample. Results of analyses show both a pattern of brain morphology that is consistently different between all apes and humans, as well as patterns that differ among species. Further, both the consistent and species-specific patterns include cortical and subcortical features. The pattern that remains consistent across species indicates a morphological reorganization of 1) relationships between cortical and subcortical frontal structures, 2) expansion of the temporal lobe and location of the amygdala, and 3) expansion of the anterior parietal region. Additionally, results demonstrate that, although there is a pattern of morphology that uniquely defines the human brain, there are also patterns that uniquely differentiate human morphology from the morphology of each non-human ape species, indicating that reorganization of neural morphology occurred at the evolutionary divergence of each of these groups. PMID:21056456
Role of multidetector computed tomography in evaluating incidentally detected breast lesions.
Moschetta, Marco; Scardapane, Arnaldo; Lorusso, Valentina; Rella, Leonarda; Telegrafo, Michele; Serio, Gabriella; Angelelli, Giuseppe; Ianora, Amato Antonio Stabile
2015-01-01
Computed tomography (CT) does not represent the primary method for the evaluation of breast lesions; however, it can detect breast abnormalities, even when performed for other reasons related to thoracic structures. The aim of this study is to evaluate the potential benefits of 320-row multidetector CT (MDCT) in evaluating and differentiating incidentally detected breast lesions by using vessel probe and 3D analysis software with net enhancement value. Sixty-two breast lesions in 46 patients who underwent 320-row chest CT examination were retrospectively evaluated. CT scans were assessed searching for the presence, location, number, morphological features, and density of breast nodules. Net enhancement was calculated by subtracting precontrast density from the density obtained by postcontrast values. The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and diagnostic accuracy of CT were calculated for morphological features and net enhancement. Thirty of 62 lesions were found to be malignant at histological examination and 32 were found to be benign. When morphological features were considered, the sensitivity, specificity, accuracy, PPV, and NPV of CT were 87%, 100%, 88%, 100%, and 50%, respectively. Based on net enhancement, CT reached a sensitivity, specificity, accuracy, PPV, and NPV of 100%, 94%, 97%, 94%, and 100%, respectively. MDCT allows to recognize and characterize breast lesions based on morphological features. Net enhancement can be proposed as an additional accurate feature of CT.
The influence of the San Gregorio fault on the morphology of Monterey Canyon
McHugh, C.M.G.; Ryan, William B. F.; Eittreim, S.; Donald, Reed
1998-01-01
A side-scan sonar survey was conducted of Monterey Canyon and the San Gregorio fault zone, off shore of Monterey Bay. The acoustic character and morphology of the sonar images, enhanced by SeaBeam bathymetry, show the path of the San Gregorio fault zone across the shelf, upper slope, and Monterey Canyon. High backscatter linear features a few kilometers long and 100 to 200 m wide delineate the sea-floor expression of the fault zone on the shelf. Previous studies have shown that brachiopod pavements and carbonate crusts are the source of the lineations backscatter. In Monterey Canyon, the fault zone occurs where the path of the canyon makes a sharp bend from WNW to SSW (1800 m). Here, the fault is marked by NW-SE-trending, high reflectivity lineations that cross the canyon floor between 1850 m and 1900 m. The lineations can be traced to ridges on the northwestern canyon wall where they have ~ 15 m of relief. Above the low-relief ridges, bowl-shaped features have been excavated on the canyon wall contributing to the widening of the canyon. We suggest that shear along the San Gregorio fault has led to the formation of the low-relief ridges near the canyon wall and that carbonate crusts, as along the shelf, may be the source of the high backscatter features on the canyon floor. The path of the fault zone across the upper slope is marked by elongated tributary canyons with high backscatter floors and 'U'-shaped cross-sectional profiles. Linear features and stepped scarps suggestive of recent crustal movement and mass-wasting, occur on the walls and floors of these canyons. Three magnitude-4 earthquakes have occurred within the last 30 years in the vicinity of the canyons that may have contributed to the observed features. As shown by others, motion along the fault zone has juxtaposed diverse lithologies that outcrop on the canyon walls. Gully morphology and the canyon's drainage patterns have been influenced by the substrate into which the gullies have formed.
Carroll, Matthew; Dalbeth, Nicola; Allen, Bruce; Stewart, Sarah; House, Tony; Boocock, Mark; Frampton, Christopher; Rome, Keith
2017-10-01
To investigate the frequency and distribution of characteristics of the Achilles tendon (AT) in people with tophaceous gout using musculoskeletal ultrasound (US). Twenty-four participants with tophaceous gout and 24 age- and sex-matched controls without gout or other arthritis were recruited. All participants underwent a greyscale and power Doppler US examination. The AT was divided into 3 anatomical zones (insertion, pre-insertional, and proximal to the mid-section). The following US characteristics were assessed: tophus, tendon echogenicity, tendon vascularity, tendon morphology, entheseal characteristics, bursal morphology, and calcaneal bone profile. The majority of the participants with tophaceous gout were middle-aged men (n = 22, 92%) predominately of European ethnicity (n = 14, 58%). Tophus deposition was observed in 73% (n = 35) of tendons in those with gout and in none of the controls (p < 0.01). Intratendinous hyperechoic spots (p < 0.01) and intratendinous power Doppler signal (p < 0.01) were more frequent in participants with gout compared to controls. High prevalence of entheseal calcifications, calcaneal bone cortex irregularities, and calcaneal enthesophytes were observed in both gout participants and controls, without differences between groups. Intratendinous structural damage was rare. Hyperechoic spots were significantly more common at the insertion compared to the zone proximal to the mid-section (p < 0.01), but between-zone differences were not observed for other features. US features of urate deposition, tophus, and vascularization are present throughout the AT in patients with tophaceous gout. Despite crystal deposition, intratendinous structural changes are infrequent. Many characteristics observed in the AT in people with tophaceous gout, particularly at the calcaneal enthesis, are not disease-specific.
NASA Astrophysics Data System (ADS)
Momary, Thomas W.; Baines, K. H.; Brown, R. H.; Buratti, B. J.; Clark, R. N.; Nicholson, P. D.; Sotin, C.
2012-10-01
A massive dark anti-cyclonic storm system on Saturn spanning some 7∘ of longitude and 2∘ of latitude was observed by Cassini/VIMS at a planetocentric latitude of 37∘ on 4 January 2012 and 26 January 2012. During this time, it drifted some 54∘ of longitude at a speed of 23.1 ± 0.2 m/s prograde, a drift speed which correlates well with the canonical Voyager (and VIMS) wind profiles for Saturn at this latitude. The spot also drifted northward during this time by 1∘ and became noticeably "squished" in morphology. Using this drift rate and extrapolating backward, we find that the position corresponds to the large (> 5,000 km) anti-cyclone observed by VIMS on 11 May 2011 at 35.4∘ latitude (pc) and 49.4∘ W. longitude. This would represent 8 months of observation of this titanic feature, which was associated with the major lightning storm of 2010-2011, following the spot as it changed in size and morphology and drifted northward. The spot underwent a dramatic shift in shape in the 3 weeks of January, changing from roughly oval to a highly elongated pancake shape as it apparently bumped up against the dark band at 40∘ latitude and experienced a powerful shear. The evolution suggests that we are watching the death throes of this feature in our most recent observations. Finally, the dark spot was darker than surrounding regions in May 2011 and maintained its dark color across all pseudo-continua from 1.0 to 4.0 μm between May 2011 and early January 2012.
CD56+ blastic transformation of chronic myeloid leukemia involving the skin.
Kaddu, S; Beham-Schmid, C; Zenahlik, P; Kerl, H; Cerroni, L
1999-11-01
We report on two patients with chronic myeloid leukemia (CML) who presented blastic transformation involving the skin, with leukemic infiltrates showing unusual morphologic and immunohistologic characteristics. Both patients were elderly men with a 36-month and a 40-month history of CML, respectively. They presented with disseminated, reddish to violaceous papules and plaques (case 1), and with localized reddish nodules on the left temporal area (case 2). Concurrent features of blastic transformation in the bone marrow were observed in one patient (case 1). Histopathologic examination of skin lesions revealed similar features in both cases. There was a moderate to dense dermal infiltrate composed mainly of medium-sized atypical mononuclear myeloid precursor cells with only few relatively well-differentiated cells of the granulocytic series. Histochemical staining for naphthol-ASD-chloroacetate esterase revealed strong positivity (>50% of neoplastic cells) in case 2 and only scattered positivity (< 10% of neoplastic cells) in case 1. Immunohistologic analysis performed on paraffin-embedded sections showed in both cases variable reactivity of neoplastic cells for leucocyte common antigen (CD45), lysozyme, myeloperoxidase, CD11c, CD15, CD43, CD66, CD68, HLA-DR, and the neural cell adhesion molecule (NCAM) CD56. A negative reaction was observed for CD3, CD34, and TdT. The immunohistologic findings were remarkably similar to those reported for acute myeloid leukemia (AML) with monocytic differentiation (French-American-British [FAB] classification, subtype M4). Examination of blasts from the bone marrow performed in one patient (case 1) revealed a similar phenotype also with CD56 expression. In conclusion, our observations show that specific cutaneous infiltrates in CML may show morphologic and immunohistochemical characteristics similar to those observed in AML with monocytic differentiation. Moreover, specific cutaneous manifestations of CML may express CD56.
A new Miocene baleen whale from Peru deciphers the dawn of cetotheriids
2017-01-01
Cetotheriidae are an iconic, nearly extinct family of baleen whales (Mysticeti) with a highly distinct cranial morphology. Their origins remain a mystery, with even the most archaic species showing a variety of characteristic features. Here, we describe a new species of archaic cetotheriid, Tiucetus rosae, from the Miocene of Peru. The new material represents the first mysticete from the poorly explored lowest portion of the highly fossiliferous Pisco Formation (allomember P0), and appears to form part of a more archaic assemblage than observed at the well-known localities of Cerro Colorado, Cerro los Quesos, Sud-Sacaco and Aguada de Lomas. Tiucetus resembles basal plicogulans (crown Mysticeti excluding right whales), such as Diorocetus and Parietobalaena, but shares with cetotheriids a distinct morphology of the auditory region, including the presence of an enlarged paroccipital concavity. The distinctive morphology of Tiucetus firmly places Cetotheriidae in the context of the poorly understood ‘cetotheres’ sensu lato, and helps to resolve basal relationships within crown Mysticeti. PMID:28989761
de Queiroz, Alexya Cunha; Vallinoto, Marcelo; Sakai, Yoichi; Giarrizzo, Tommaso
2018-01-01
The mimetic juveniles of a number of carangid fish species resemble plant parts floating near the water surface, such as leaves, seeds and other plant debris. The present study is the first to verify the morphological similarities and ecomorphological relationships between three carangids (Oligoplites saurus, Oligoplites palometa and Trachinotus falcatus) and their associated plant models. Behavioral observations were conducted in the estuary of Curuçá River, in northeastern Pará (Brazil) between August 2015 and July 2016. Individual fishes and associated floating objects (models) were sampled for comparative analysis using both geometric and morphometric approaches. While the mimetic fish and their models retain their own distinct, intrinsic morphological features, a high degree of morphological similarity was found between each fish species and its model. The morphometric analyses revealed a general tendency of isometric development in all three fish species, probably related to their pelagic habitats, during all ontogenetic stages. PMID:29558476
A new Miocene baleen whale from Peru deciphers the dawn of cetotheriids
NASA Astrophysics Data System (ADS)
Marx, Felix G.; Lambert, Olivier; de Muizon, Christian
2017-09-01
Cetotheriidae are an iconic, nearly extinct family of baleen whales (Mysticeti) with a highly distinct cranial morphology. Their origins remain a mystery, with even the most archaic species showing a variety of characteristic features. Here, we describe a new species of archaic cetotheriid, Tiucetus rosae, from the Miocene of Peru. The new material represents the first mysticete from the poorly explored lowest portion of the highly fossiliferous Pisco Formation (allomember P0), and appears to form part of a more archaic assemblage than observed at the well-known localities of Cerro Colorado, Cerro los Quesos, Sud-Sacaco and Aguada de Lomas. Tiucetus resembles basal plicogulans (crown Mysticeti excluding right whales), such as Diorocetus and Parietobalaena, but shares with cetotheriids a distinct morphology of the auditory region, including the presence of an enlarged paroccipital concavity. The distinctive morphology of Tiucetus firmly places Cetotheriidae in the context of the poorly understood `cetotheres' sensu lato, and helps to resolve basal relationships within crown Mysticeti.
A numerical retroaction model relates rocky coast erosion to percolation theory
NASA Astrophysics Data System (ADS)
Sapoval, B.; Baldassarri, A.
2011-12-01
Rocky coasts are estimated to represent 75% of the world's shorelines [1]. We discuss various situations where the formation of rocky coast morphology could be attributed to the retroaction of the coast morphology on the erosive power of the see. In the case of rocky coasts, erosion can spontaneously create irregular seashores. But, in turn, the geometrical irregularity participates to the damping of sea-waves, decreasing the average wave amplitude and erosive power. There may then exist a mutual self-stabilization of the waves amplitude together with the irregular morphology of the coast. A simple model of such stabilization is discussed. It leads, through a complex avalanche dynamics of the earth-sea interface, to the spontaneous appearance of an irregular sea-shore. The final coast morphology is found to depend on the morphology/damping coupling of the coast and on the possible existence of built-in correlations within the coast lithologic properties. In the limit case where the morphology/damping coupling is weak and when the earth lithology distribution exhibit only short range correlations, the process spontaneously build fractal morphologies with a dimension close to 4/3 [2]. This dimension refers to the dimension of the accessible perimeter in percolation theory. However, even rugged but non-fractal sea-coasts morphology may emerge for strong damping or during the erosion process. When the distributions of the lithologies exhibit long range correlations, a variety of complex morphologies are obtained which mimics observed coastline complexity, well beyond simple fractality. This approach, which links erosion of rocky coasts to percolation theory, provide a natural frame to explain the frequent field observation that the statistics of erosion events follow power law behavior. In a somewhat different perspective, the design of breakwaters is suggested to be improved by using global irregular geometry with features sizes of the order of the wave-length of the sea oscillations. [1] R. A. Davis, Jr, D. M. Fitzgerald, Beaches and Coasts,(Blackwell, Oxford 2004). [2] B. Sapoval, A. Baldassarri, A. Gabrielli, Self-stabilized Fractality of Sea-coasts through Erosion, Phys. Rev. Lett. 93, 098501 (2004).
2014-01-01
Background Thylacocephala is a group of enigmatic extinct arthropods. Here we provide a full description of the oldest unequivocal thylacocephalan, a new genus and species Thylacares brandonensis, which is present in the Silurian Waukesha fauna from Wisconsin, USA. We also present details of younger, Jurassic specimens, from the Solnhofen lithographic limestones, which are crucial to our interpretation of the systematic position of Thylacocephala. In the past, Thylacocephala has been interpreted as a crustacean ingroup and as closely related to various groups such as cirripeds, decapods or remipeds. Results The Waukesha thylacocephalan, Thylacares brandonensis n. gen. n. sp., bears compound eyes and raptorial appendages that are relatively small compared to those of other representatives of the group. As in other thylacocephalans the large bivalved shield encloses much of the entire body. The shield lacks a marked optical notch. The eyes, which project just beyond the shield margin, appear to be stalked. Head appendages, which may represent antennulae, antennae and mandibles, appear to be present. The trunk is comprised of up to 22 segments. New details observed on thylacocephalans from the Jurassic Solnhofen lithographic limestones include antennulae and antennae of Mayrocaris bucculata, and endites on the raptorial appendages and an elongate last trunk appendage in Clausocaris lithographica. Preserved features of the internal morphology in C. lithographica include the muscles of the raptorial appendage and trunk. Conclusions Our results indicate that some ‘typical’ thylacocephalan characters are unique to the group; these autapomorphies contribute to the difficulty of determining thylacocephalan affinities. While the new features reported here are consistent with a eucrustacean affinity, most previous hypotheses for the position of Thylacocephala within Eucrustacea (as Stomatopoda, Thecostraca or Decapoda) are shown to be unlikely. A sister group relationship to Remipedia appears compatible with the observed features of Thylacocephala but more fossil evidence is required to test this assertion. The raptorial appendages of Thylacocephala most likely projected 45 degrees abaxially instead of directly forward as previously reconstructed. The overall morphology of thylacocephalans supports a predatory mode of life. PMID:25927449
NASA Astrophysics Data System (ADS)
Leonard, E. J.; Pappalardo, R. T.; Yin, A.; Prockter, L. M.; Patthoff, D. A.
2014-12-01
The Galileo Solid State Imager (SSI) recorded nine very high-resolution frames (8 at 12 m/pixel and 1 at 6 m/pixel) during the E12 flyby of Europa in Dec. 1997. To understand the implications for the small-scale structure and evolution of Europa, we mosaicked these frames (observations 12ESMOTTLE01 and 02, incidence ≈18°, emission ≈77°) into their regional context (part of observation 11ESREGMAP01, 220 m/pixel, incidence ≈74°, emission ≈23°), despite their very different viewing and lighting conditions. We created a map of geological units based on morphology, structure, and albedo along with stereoscopic images where the frames overlapped. The highly diverse units range from: high albedo sub-parallel ridge and grooved terrain; to variegated-albedo hummocky terrain; to low albedo and relatively smooth terrain. We classified and analyzed the diverse units solely based on the high-resolution image mosaic, prior to comparison to the context image, to obtain an in-depth look at possible surface evolution and underlying formational processes. We infer that some of these units represent different stages and forms of resurfacing, including cryovolcanic and tectonic resurfacing. However, significant morphological variation among units in the region indicates that there are different degrees of resurfacing at work. We have created candidate morphological sequences that provide insight into the conversion of ridged plains to chaotic terrain—generally, a process of subduing formerly sharp features through tectonic modification and/or cryovolcanism. When the map of the high-resolution area is compared to the regional context, features that appear to be one unit at regional resolution are comprised of several distinct units at high resolution, and features that appear to be smooth in the context image are found to show distinct textures. Moreover, in the context image, transitions from ridged units to disrupted units appear to be gradual; however the high-resolution image reveals them to be abrupt, suggesting tectonic control of these boundaries. These discrepancies could have important implications for a future landed exploration.
Haug, Carolin; Briggs, Derek E G; Mikulic, Donald G; Kluessendorf, Joanne; Haug, Joachim T
2014-08-22
Thylacocephala is a group of enigmatic extinct arthropods. Here we provide a full description of the oldest unequivocal thylacocephalan, a new genus and species Thylacares brandonensis, which is present in the Silurian Waukesha fauna from Wisconsin, USA. We also present details of younger, Jurassic specimens, from the Solnhofen lithographic limestones, which are crucial to our interpretation of the systematic position of Thylacocephala. In the past, Thylacocephala has been interpreted as a crustacean ingroup and as closely related to various groups such as cirripeds, decapods or remipeds. The Waukesha thylacocephalan, Thylacares brandonensis n. gen. n. sp., bears compound eyes and raptorial appendages that are relatively small compared to those of other representatives of the group. As in other thylacocephalans the large bivalved shield encloses much of the entire body. The shield lacks a marked optical notch. The eyes, which project just beyond the shield margin, appear to be stalked. Head appendages, which may represent antennulae, antennae and mandibles, appear to be present. The trunk is comprised of up to 22 segments. New details observed on thylacocephalans from the Jurassic Solnhofen lithographic limestones include antennulae and antennae of Mayrocaris bucculata, and endites on the raptorial appendages and an elongate last trunk appendage in Clausocaris lithographica. Preserved features of the internal morphology in C. lithographica include the muscles of the raptorial appendage and trunk. Our results indicate that some 'typical' thylacocephalan characters are unique to the group; these autapomorphies contribute to the difficulty of determining thylacocephalan affinities. While the new features reported here are consistent with a eucrustacean affinity, most previous hypotheses for the position of Thylacocephala within Eucrustacea (as Stomatopoda, Thecostraca or Decapoda) are shown to be unlikely. A sister group relationship to Remipedia appears compatible with the observed features of Thylacocephala but more fossil evidence is required to test this assertion. The raptorial appendages of Thylacocephala most likely projected 45 degrees abaxially instead of directly forward as previously reconstructed. The overall morphology of thylacocephalans supports a predatory mode of life.
Electrocardiogram ST-Segment Morphology Delineation Method Using Orthogonal Transformations
2016-01-01
Differentiation between ischaemic and non-ischaemic transient ST segment events of long term ambulatory electrocardiograms is a persisting weakness in present ischaemia detection systems. Traditional ST segment level measuring is not a sufficiently precise technique due to the single point of measurement and severe noise which is often present. We developed a robust noise resistant orthogonal-transformation based delineation method, which allows tracing the shape of transient ST segment morphology changes from the entire ST segment in terms of diagnostic and morphologic feature-vector time series, and also allows further analysis. For these purposes, we developed a new Legendre Polynomials based Transformation (LPT) of ST segment. Its basis functions have similar shapes to typical transient changes of ST segment morphology categories during myocardial ischaemia (level, slope and scooping), thus providing direct insight into the types of time domain morphology changes through the LPT feature-vector space. We also generated new Karhunen and Lo ève Transformation (KLT) ST segment basis functions using a robust covariance matrix constructed from the ST segment pattern vectors derived from the Long Term ST Database (LTST DB). As for the delineation of significant transient ischaemic and non-ischaemic ST segment episodes, we present a study on the representation of transient ST segment morphology categories, and an evaluation study on the classification power of the KLT- and LPT-based feature vectors to classify between ischaemic and non-ischaemic ST segment episodes of the LTST DB. Classification accuracy using the KLT and LPT feature vectors was 90% and 82%, respectively, when using the k-Nearest Neighbors (k = 3) classifier and 10-fold cross-validation. New sets of feature-vector time series for both transformations were derived for the records of the LTST DB which is freely available on the PhysioNet website and were contributed to the LTST DB. The KLT and LPT present new possibilities for human-expert diagnostics, and for automated ischaemia detection. PMID:26863140
NASA Astrophysics Data System (ADS)
McClinton, J. T.; White, S. M.; Sinton, J. M.; Rubin, K. H.; Bowles, J. A.
2010-12-01
Differences in axial lava morphology along the Galapagos Spreading Center (GSC) can indicate variations in magma supply and emplacement dynamics due to the influence of the adjacent Galapagos hot spot. Unfortunately, the ability to discriminate fine-scale lava morphology has historically been limited to observations of the small coverage areas of towed camera surveys and submersible operations. This research presents a neuro-fuzzy approach to automated seafloor classification using spatially coincident, high-resolution bathymetry and backscatter data. The classification method implements a Sugeno-type fuzzy inference system trained by a multi-layered adaptive neural network and is capable of rapidly classifying seafloor morphology based on attributes of surface geometry and texture. The system has been applied to the 92°W segment of the western GSC in order to quantify coverage areas and distributions of pillow, lobate, and sheet lava morphology. An accuracy assessment has been performed on the classification results. The resulting classified maps provide a high-resolution view of GSC axial morphology and indicate the study area terrain is approximately 40% pillow flows, 40% lobate and sheet flows, and 10% fissured or faulted area, with about 10% of the study area unclassifiable. Fine-scale features such as eruptive fissures, tumuli, and individual pillowed lava flow fronts are also visible. Although this system has been applied to lava morphology, its design and implementation are applicable to other undersea mapping applications.
NASA Astrophysics Data System (ADS)
McGowan, H. A.; Neil, D.
2005-12-01
The identification of sources of water on Mars will be critical to the successful exploration of the planet and the establishment of a permanent presence by humans. While the Martian polar ice caps contain up to 70% water by mass, the extreme climate of these regions means that they may not be suitable for habitation. As a result, other sites must be identified where access to water is possible. Recent evidence has emerged that suggests sand dunes on Mars may contain 40-50% water by mass (Bourke 2005). In this paper, we present niveo-aeolian features observed in the sand dunes of the Victoria Valley, Antarctica, which have long been considered an Earth analogue for those on Mars (Morris et al. 1972). These features include cornices of permafrosted sand in dune-crest deflation hollows, exposed erosion resistant frozen water and sand lenses, wet sand flows and seeps. We also report on the morphological characteristics of sand sink holes which form in chains above layers of buried, melting and/or sublimating snow. This process is apparently reliant on the melting of inter-grain ice bonds and subsequent formation of a dry mobile sand layer on the dune surface. These micro-morphological features associated with summertime denivation of the Victoria Valley sand dunes, which are 5 to 10 m high and several hundred meters in crest length, are too small to identify on air photographs, satellite imagery and LIDAR DEMS of these transverse barchanoid ridges. However, on Mars where sand dunes are 1 to 2 orders of magnitude larger, these features may be identifiable if solid water exists within them, as suggested by Bourke (2005). Perhaps of greater importance, they may indicate the presence of buried palaeo-snow layers which have been preserved beneath the erosion resistant permafrosted sand dunes on Mars. We believe that the formation and subsequent exposure of these snow layers is the primary cause of the denivation features present in the polar dunes of the Victoria Valley, Antarctica. References: Bourke, M.C. 2005: Water on Mars. The Halstead Lecture, British Association for the Advancement of Science, Trinity College, Dublin, September 2005. Morris, E.C., Mutch, T.A. and Holt, H.E. 1972: Atlas of geologic features in the Dry Valleys of South Victoria Land, Antarctica: Possible analogs of Martian surface features. Interagency report: Astrogeology 52. Prepared under NASA contract L-9718 by the Geological Survey.
Morphological learning in a novel language: A cross-language comparison.
Havas, Viktória; Waris, Otto; Vaquero, Lucía; Rodríguez-Fornells, Antoni; Laine, Matti
2015-01-01
Being able to extract and interpret the internal structure of complex word forms such as the English word dance+r+s is crucial for successful language learning. We examined whether the ability to extract morphological information during word learning is affected by the morphological features of one's native tongue. Spanish and Finnish adult participants performed a word-picture associative learning task in an artificial language where the target words included a suffix marking the gender of the corresponding animate object. The short exposure phase was followed by a word recognition task and a generalization task for the suffix. The participants' native tongues vary greatly in terms of morphological structure, leading to two opposing hypotheses. On the one hand, Spanish speakers may be more effective in identifying gender in a novel language because this feature is present in Spanish but not in Finnish. On the other hand, Finnish speakers may have an advantage as the abundance of bound morphemes in their language calls for continuous morphological decomposition. The results support the latter alternative, suggesting that lifelong experience on morphological decomposition provides an advantage in novel morphological learning.
NASA Astrophysics Data System (ADS)
Zhu, Yizheng; Li, Chengshuai
2016-03-01
Morphological assessment of spermatozoa is of critical importance for in vitro fertilization (IVF), especially intracytoplasmic sperm injection (ICSI)-based IVF. In ICSI, a single sperm cell is selected and injected into an egg to achieve fertilization. The quality of the sperm cell is found to be highly correlated to IVF success. Sperm morphology, such as shape, head birefringence and motility, among others, are typically evaluated under a microscope. Current observation relies on conventional techniques such as differential interference contrast microscopy and polarized light microscopy. Their qualitative nature, however, limits the ability to provide accurate quantitative analysis. Here, we demonstrate quantitative morphological measurement of sperm cells using two types of spectral interferometric techniques, namely spectral modulation interferometry and spectral multiplexing interferometry. Both are based on spectral-domain low coherence interferometry, which is known for its exquisite phase determination ability. While spectral modulation interferometry encodes sample phase in a single spectrum, spectral multiplexing interferometry does so for sample birefringence. Therefore they are capable of highly sensitive phase and birefringence imaging. These features suit well in the imaging of live sperm cells, which are small, dynamic objects with only low to moderate levels of phase and birefringence contrast. We will introduce the operation of both techniques and demonstrate their application to measuring the phase and birefringence morphology of sperm cells.
NASA Astrophysics Data System (ADS)
Rivera Nieves, A.; Loubriel, M.; Rodriguez-Abudo, S.; Canals, M.; Salgado-Domínguez, G.
2016-02-01
Seasonal variations in the wave climate near Rincón, Puerto Rico include high winter swells associated with meteorological disturbances in the north and mid Atlantic, short period waves resulting from local storms, and the occasional south swell. The resulting beach morphology is therefore a complex function of the wave climate, wave-induced currents, and local and remote meteorology, among others. Over the past 75 years, this particular stretch of beach has suffered severe erosion problems, losing as much as 100 meters of beach width at particular locations. The purpose of this study is to develop a high-resolution time series of beach morphology to examine in more detail the seasonal variations at the site. Beach profiles will be collected on a weekly basis using an RTK GPS system at three permanent stations spanning 2 km of coast. Sediment samples will be collected along the profiles to identify sediment properties associated with distinct morphological features, while digital photographs will provide a qualitative sense of beach width. The resulting morphological changes will be assessed in light of the Rincon's directional Waverider buoy data and CariCOOS' SWAN high-resolution wave model. This study will provide quantifiable insights into seasonal erosion/accretion trends at a highly touristic stretch of coast in the US Caribbean.
Mining CANDELS for Tidal Features to Constrain Major Merging During Cosmic Noon
NASA Astrophysics Data System (ADS)
McIntosh, Daniel H.; Mantha, Kameswara; Ciaschi, Cody; Evan, Rubyet A.; Fries, Logan B.; Landry, Luther; Thompson, Scott E.; Snyder, Gregory; Guo, Yicheng; Ceverino, Daniel; Häuβler, Boris; Primack, Joel; Simons, Raymond C.; Zheng, Xianzhong; Cosmic Assembly Near-Infrared Deep Extragalactic Legacy Survey (CANDELS) Team
2018-01-01
The role of major merging in the rapid buildup and development of massive galaxies at z>1 remains an open question. New theories and observations suggest that non-merging processes like violent disk instabilities may be more vital than previously thought at assembling bulges, producing clumps, and inducing morphological disturbances that may be misinterpreted as the product of major merging. We will present initial results on a systematic search for hallmark tidal indicators of major merging in a complete sample of nearly 6000 massive z>1 galaxies from CANDELS (Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey), the premiere HST/WFC3 Treasury program. We have visually inspected published GALFIT F160W residual (image-model) maps and produced a comprehensive new catalog of Sersic residual characteristics based on a variety of natural features and poor-fit artifacts. Using this catalog, we find the frequency of galaxies with tidal signatures is very small in CANDELS data. Accounting for the brief time scale associated with faint transient tidal features, our preliminary finding indicates that merger fractions derived from the CANDELS morphological classification efforts are substantially overestimated. We are using the database of residual classifications as a baseline to (1) produce improved multi-component residual maps using GALFIT_M, (2) automatically extract and quantify plausible tidal indicators and substructures (clumps vs. multiple nuclei), (3) develop a new deep-learning classification pipeline to robustly identify merger indicators in imaging data, and (4) inform the systematic analyses of synthetic mock (CANDELized) images from zoom-in hydrodynamic simulations to thoroughly quantify the impacts of cosmological dimming, and calibrate the observability timescale of tidal feature detections. Our study will ultimately yield novel constraints on merger rates at z>1 and a definitive census of massive high-noon galaxies with tidal and double-nuclei merging signatures in rest-frame optical HST imaging.
NASA Technical Reports Server (NTRS)
Busso, G.; Piotto, G.; Cassisi, S.; Romaniello, M.; Castelli, F.; Catelan, M.; Djorgovski, S. G.; King, I. R.; Landsman, W. B.; Blanco, A. Reico;
2006-01-01
In this paper we present multiband optical and UV Hubble Space Telescope photometry of the two Galactic globular clusters NGC 6388 and NGC 6441 Aims. We investigate the properties of their anomalous horizontal branches (HB) in different photometric planes in order to shed light on the nature of the physical mechanism(s) responsible for the existence of an extended HB blue tail, and of a slope in the HB, visible in all the color-magnitude diagrams. Methods. New photometric data have been collected and carefully reduced. Empirical data have been compared with updated stellar models of low-mass, metal-rich, He-burning structures, transformed to the observational plane with appropriate atmosphere models. Results. We have obtained the first UV color-magnitude diagrams for NGC 6388 and NGC 6441. These diagrams confirm previous results, obtained in optical bands, about the presence of a sizeable stellar population of extremely hot Horizontal Branch stars. At least in NGC 6388, we find a clear indication that at the hot end of the horizontal branch the distribution of stars forms a hook-like feature, closely resembling those observed in NGC 2808 and w Centauri. We briefly review the theoretical scenarios which have been suggested for interpreting this observational feature. We investigate also on the tilt in the horizontal branch morphology, and provide further evidence that supports early suggestions according to which this feature cannot be interpreted as an effect of differential reddening or radiative levitation, though these effects contribute to create the anomaly. We demonstrate that a possible solution of the puzzle is to assume that a small fraction (approx. 13% in NGC 6388 and approx. 8% NGC 6441) of the stellar population in the two clusters is strongly helium enriched (Y approx. 0.40 in NGC6388 and Y approx. 0.35 in NGC 6441). This solution necessarily implies the presence of a double generation of stars in the two clusters.
Predicting Future Morphological Changes of Lesions from Radiotracer Uptake in 18F-FDG-PET Images
Bagci, Ulas; Yao, Jianhua; Miller-Jaster, Kirsten; Chen, Xinjian; Mollura, Daniel J.
2013-01-01
We introduce a novel computational framework to enable automated identification of texture and shape features of lesions on 18F-FDG-PET images through a graph-based image segmentation method. The proposed framework predicts future morphological changes of lesions with high accuracy. The presented methodology has several benefits over conventional qualitative and semi-quantitative methods, due to its fully quantitative nature and high accuracy in each step of (i) detection, (ii) segmentation, and (iii) feature extraction. To evaluate our proposed computational framework, thirty patients received 2 18F-FDG-PET scans (60 scans total), at two different time points. Metastatic papillary renal cell carcinoma, cerebellar hemongioblastoma, non-small cell lung cancer, neurofibroma, lymphomatoid granulomatosis, lung neoplasm, neuroendocrine tumor, soft tissue thoracic mass, nonnecrotizing granulomatous inflammation, renal cell carcinoma with papillary and cystic features, diffuse large B-cell lymphoma, metastatic alveolar soft part sarcoma, and small cell lung cancer were included in this analysis. The radiotracer accumulation in patients' scans was automatically detected and segmented by the proposed segmentation algorithm. Delineated regions were used to extract shape and textural features, with the proposed adaptive feature extraction framework, as well as standardized uptake values (SUV) of uptake regions, to conduct a broad quantitative analysis. Evaluation of segmentation results indicates that our proposed segmentation algorithm has a mean dice similarity coefficient of 85.75±1.75%. We found that 28 of 68 extracted imaging features were correlated well with SUVmax (p<0.05), and some of the textural features (such as entropy and maximum probability) were superior in predicting morphological changes of radiotracer uptake regions longitudinally, compared to single intensity feature such as SUVmax. We also found that integrating textural features with SUV measurements significantly improves the prediction accuracy of morphological changes (Spearman correlation coefficient = 0.8715, p<2e-16). PMID:23431398
Genomic analysis of WCP30 Phage of Weissella cibaria for Dairy Fermented Foods.
Lee, Young-Duck; Park, Jong-Hyun
2017-01-01
In this study, we report the morphogenetic analysis and genome sequence of a new WCP30 phage of Weissella cibaria , isolated from a fermented food. Based on its morphology, as observed by transmission electron microscopy, WCP30 phage belongs to the family Siphoviridae . Genomic analysis of WCP30 phage showed that it had a 33,697-bp double-stranded DNA genome with 41.2% G+C content. Bioinformatics analysis of the genome revealed 35 open reading frames. A BLASTN search showed that WCP30 phage had low sequence similarity compared to other phages infecting lactic acid bacteria. This is the first report of the morphological features and complete genome sequence of WCP30 phage, which may be useful for controlling the fermentation of dairy foods.
Characterization of Capsicum species using anatomical and molecular data.
Dias, G B; Gomes, V M; Moraes, T M S; Zottich, U P; Rabelo, G R; Carvalho, A O; Moulin, M; Gonçalves, L S A; Rodrigues, R; Da Cunha, M
2013-02-28
Capsicum species are frequently described in terms of genetic divergence, considering morphological, agronomic, and molecular databases. However, descriptions of genetic differences based on anatomical characters are rare. We examined the anatomy and the micromorphology of vegetative and reproductive organs of several Capsicum species. Four Capsicum accessions representing the species C. annuum var. annuum, C. baccatum var. pendulum, C. chinense, and C. frutescens were cultivated in a greenhouse; leaves, fruits and seeds were sampled and their organ structure analyzed by light and scanning electronic microscopy. Molecular accession characterization was made using ISSR markers. Polymorphism was observed among tector trichomes and also in fruit color and shape. High variability among accessions was detected by ISSR markers. Despite the species studied present a wide morphological and molecular variability that was not reflected by anatomical features.
Supernova Remnant Evolving in Wind-Blown Bubbles: A Case Study of Kes 27
NASA Astrophysics Data System (ADS)
Li, Jiangtao
2013-10-01
Mixed-morphology (MM) SNRs represent SN explosion in wind-blown bubbles. They are thus good places to study the interaction between massive stellar winds, SNRs, and the surrounding ISM. We propose a 50ks XMM-Newton observation of a peculiar MM SNR, Kes 27. We will map out the spectral parameters in tessellated meshes and construct EW maps of some emission lines with our newly developed spatially-resolved spectroscopy method. These analyses will help us to understand the unusual properties of this MM SNR, such as the X-ray bright outer shell, shell-like interior, and strong NE-SW asymmetry in morphology. We will also search for evidence of over-ionization state plasma and coherent X-ray features associated with the shell of the HI cavity.
Slip as the basic mechanism for formation of deformation relief structural elements
NASA Astrophysics Data System (ADS)
Lychagin, D. V.; Alfyorova, E. A.
2017-07-01
The experimental results of investigation of the nickel single crystal surface morphology after compression deformation are presented. The quasi-periodic character of the deformation profile, common for shear deformation of different types of relief structural elements, is found. It is demonstrated that the morphological manifestation of these structural elements is determined by local shear systems along octahedral planes. The regularities of the deformation structure in these regions defining the material extrusion and intrusion regions and the specific features of disorientation accumulation are established. If reorientation of local regions takes part in the relief element formation, along with octahedral slip, much stronger growth of the surface area is observed. The possibility of application of two-dimensional and three-dimensional surface roughness parameters for description of deformation relief is considered.
Airborne spectrophotometry of Eta Carinae from 4.5 to 7.5 microns and a model for source morphology
NASA Technical Reports Server (NTRS)
Russell, Ray W.; Lynch, David K.; Hackwell, John A.; Rudy, Richard J.; Rossano, George S.; Castelaz, M. W.
1987-01-01
Spectrophotometric observations of Eta Car between 4.5 and 7.5 microns show a featureless thermal-like spectrum with no fine-structure lines or broad emission or absorption features. The color temperature of the spectrum is approximately 375 K. High spatial resolution maps at 3.5, 4.8, and 10 microns obtained from the ground are used to discuss the dust distribution and temperature structure, and to present a model for general source morphology. The upper limit to the brightness of the forbidden Ar II fine-structure emission line at 6.98 microns is less than 7 x 10 to the -16th W/sq cm, which still allows for a significant overabundance of argon and is consistent with the evolved nature of the source.
Separation anxiety: Stress, tension and cytokinesis
DOE Office of Scientific and Technical Information (OSTI.GOV)
Mohan, Krithika; Iglesias, Pablo A., E-mail: pi@jhu.edu; Robinson, Douglas N., E-mail: dnr@jhmi.edu
Cytokinesis, the physical separation of a mother cell into two daughter cells, progresses through a series of well-defined changes in morphology. These changes involve distinct biochemical and mechanical processes. Here, we review the mechanical features of cells during cytokinesis, discussing both the material properties as well as sources of stresses, both active and passive, which lead to the observed changes in morphology. We also describe a mechanosensory feedback control system that regulates protein localization and shape progression during cytokinesis. -- Highlights: Black-Right-Pointing-Pointer Cytokinesis progresses through three distinct mechanical phases. Black-Right-Pointing-Pointer Cortical tension initially resists deformation of mother cell. Black-Right-Pointing-Pointer Latemore » in cytokinesis, cortical tension provides stress, enabling furrow ingression. Black-Right-Pointing-Pointer A mechanosensory feedback control system regulates cytokinesis.« less
Defect-mediated phonon dynamics in TaS2 and WSe2
Cremons, Daniel R.; Plemmons, Dayne A.; Flannigan, David J.
2017-01-01
We report correlative crystallographic and morphological studies of defect-dependent phonon dynamics in single flakes of 1T-TaS2 and 2H-WSe2 using selected-area diffraction and bright-field imaging in an ultrafast electron microscope. In both materials, we observe in-plane speed-of-sound acoustic-phonon wave trains, the dynamics of which (i.e., emergence, propagation, and interference) are strongly dependent upon discrete interfacial features (e.g., vacuum/crystal and crystal/crystal interfaces). In TaS2, we observe cross-propagating in-plane acoustic-phonon wave trains of differing frequencies that undergo coherent interference approximately 200 ps after initial emergence from distinct interfacial regions. With ultrafast bright-field imaging, the properties of the interfering wave trains are observed to correspond to the beat frequency of the individual oscillations, while intensity oscillations of Bragg spots generated from selected areas within the region of interest match well with the real-space dynamics. In WSe2, distinct acoustic-phonon dynamics are observed emanating and propagating away from structurally dissimilar morphological discontinuities (vacuum/crystal interface and crystal terrace), and results of ultrafast selected-area diffraction reveal thickness-dependent phonon frequencies. The overall observed dynamics are well-described using finite element analysis and time-dependent linear-elastic continuum mechanics. PMID:28503630
A novel murmur-based heart sound feature extraction technique using envelope-morphological analysis
NASA Astrophysics Data System (ADS)
Yao, Hao-Dong; Ma, Jia-Li; Fu, Bin-Bin; Wang, Hai-Yang; Dong, Ming-Chui
2015-07-01
Auscultation of heart sound (HS) signals serves as an important primary approach to diagnose cardiovascular diseases (CVDs) for centuries. Confronting the intrinsic drawbacks of traditional HS auscultation, computer-aided automatic HS auscultation based on feature extraction technique has witnessed explosive development. Yet, most existing HS feature extraction methods adopt acoustic or time-frequency features which exhibit poor relationship with diagnostic information, thus restricting the performance of further interpretation and analysis. Tackling such a bottleneck problem, this paper innovatively proposes a novel murmur-based HS feature extraction method since murmurs contain massive pathological information and are regarded as the first indications of pathological occurrences of heart valves. Adapting discrete wavelet transform (DWT) and Shannon envelope, the envelope-morphological characteristics of murmurs are obtained and three features are extracted accordingly. Validated by discriminating normal HS and 5 various abnormal HS signals with extracted features, the proposed method provides an attractive candidate in automatic HS auscultation.
NASA Astrophysics Data System (ADS)
Davide, Baioni; Forese Carlo, Wezel
2010-05-01
The Tithonium Chasma (TC) is the northern trench of the western troughs of Valles Marineris (Mars). In the easternmost part of the canyon system a mountain displaying dome shape morphology is located. The mineralogical characteristics of the dome have been indicated by the OMEGA image spectrometer data that mapped it as a sulphate deposit (OMEGA data orbit 531_3). Studies on the spectral characteristic absorptions for the hydrated magnesium sulphates carried out on the deposits within the Tithonium Chasma, showed the mineralogical components displayed by the dome in detail. According to these results the dome shows clear signatures of kieserite (Mg SO4.H2O), an evaporitic mineral also found on the Earth. Further studies carried out on the characteristics and the genesis of Kieserite both on Mars and on the Earth showed that the dome can not be constituted entirely by kieserite alone but probably it might be constituted also by the same salts that on the Earth alter to kieserite, such as, carnallite, kainite and halite. In this work we investigated in great detail the surface features of the dome located in the eastern part of TC, with the aim to try to determine its nature and origin. The morphological features of the dome have been investigated through the integrate analysis of HiRISE, HRSC, MOC and THEMIS data, while the morphometric characteristics have been measured on a topographic map (50 m contours lines) built using HRSC and MOLA data. The observation of the dome surface highlights features created by fluvio-erosional and solutional processes. The dome appears to be characterized by deep gully morphology displaying a radial system that develops from the margins of the summit plateau. The solutional surface is characterized by landforms typical of the karst morphology such as, karren, dolines and collapse dolines. Depositional forms displaying periglacial rock glacier features can be seen at the foot of the slopes, while they seem to be lacking along the dome flanks. The observation made also highlights the presence of layers outcropping on the surface of the dome. The layers display both laterally and vertically continuity apparently without facies variations. The dome seems to be formed of different materials (minerals, grain-size) with different properties. The analysis performed show that the landforms observed clearly indicate the presence of solutional processes that seem to have worked in a selective way. These landforms indicate the presence of liquid water, probably caused by the melting of ice in a periglacial environment, or permafrost rich soil, suggesting that either the material is ice-rich or was so at one time. Deposits similar to that one located in the eastern TC are found almost in all chasmata of Valles Marineris system and are well known as interior layered deposits(ILD). To explain the origin and formation mechanisms of the ILD several hypotheses have been formulated in previous studies. The results carried out in this study allow us to suppose that any of the previous hypotheses to explain its origin is fitting with the evidences found. In our opinion the data observed show evidences that allow us to suppose that the dome located in the eastern part of TC might represents the result of diapirism processes.
Steinmetz, Ivo; Lalk, Michael
2016-01-01
Background Burkholderia pseudomallei is a water and soil bacterium and the causative agent of melioidosis. A characteristic feature of this bacterium is the formation of different colony morphologies which can be isolated from environmental samples as well as from clinical samples, but can also be induced in vitro. Previous studies indicate that morphotypes can differ in a number of characteristics such as resistance to oxidative stress, cellular adhesion and intracellular replication. Yet the metabolic features of B. pseudomallei and its different morphotypes have not been examined in detail so far. Therefore, this study aimed to characterize the exometabolome of B. pseudomallei morphotypes and the impact of acute infection on their metabolic characteristics. Methods and Principal Findings We applied nuclear magnetic resonance spectroscopy (1H-NMR) in a metabolic footprint approach to compare nutrition uptake and metabolite secretion of starvation induced morphotypes of the B. pseudomallei strains K96243 and E8. We observed gluconate production and uptake in all morphotype cultures. Our study also revealed that among all morphotypes amino acids could be classified with regard to their fast and slow consumption. In addition to these shared metabolic features, the morphotypes varied highly in amino acid uptake profiles, secretion of branched chain amino acid metabolites and carbon utilization. After intracellular passage in vitro or murine acute infection in vivo, we observed a switch of the various morphotypes towards a single morphotype and a synchronization of nutrient uptake and metabolite secretion. Conclusion To our knowledge, this study provides first insights into the basic metabolism of B. pseudomallei and its colony morphotypes. Furthermore, our data suggest, that acute infection leads to the synchronization of B. pseudomallei colony morphology and metabolism through yet unknown host signals and bacterial mechanisms. PMID:26943908
Eastern Ishtar Terra: Tectonic evolution derived from recognized features
NASA Technical Reports Server (NTRS)
Vorderbruegge, R. W.; Head, James W.
1989-01-01
Previous analyses have recognized several styles and orientations of compressional deformation, crustal convergence, and crustal thickening in Eastern Ishtar Terra. An east to west sense of crustal convergence through small scale folding, thrusting, and buckling is reflected in the high topography and ridge-and-valley morphology of Maxwell Montes and the adjacent portion of Fortuna Tessera. This east to west convergence was accompanied by up to 1000 km of lateral motion and large scale strike-slip faulting within two converging shear zones which has resulted in the present morphology of Maxwell Montes. A more northeast to southwest sense of convergence through large scale buckling and imbrication is reflected in large, northwest-trending scarps along the entire northern boundary of Ishtar Terra, with up to 2 km of relief present at many of the scarps. It was previously suggested that both styles of compression have occurred at the expense of pre-existing tessera regions which have then been overprinted by the latest convergence event. The difference in style is attributed mostly to differences in the properties of the crust converging with the tessera blocks. If one, presumably thick, tessera block converges with another tessera region, then the widespread, distributed style of deformation occurs, as observed in western Fortuna Tessera. However, if relatively thin crust (such as suggested for the North Polar Plains converges with thicker tessera regions, then localized deformation occurs, as reflected in the scarps along Northern Ishtar Terra. The purpose is to identify the types of features observed in Eastern Ishtar Terra. Their potential temporal and spatial relationships, is described, possible origins for them is suggested, and how the interpretation of some of these features has led to the multiple-style tectonic evolution model described is shown.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Wang, Jason J.; Graham, James R.; Pueyo, Laurent
We present Gemini Planet Imager (GPI) observations of AU Microscopii, a young M dwarf with an edge-on, dusty debris disk. Integral field spectroscopy and broadband imaging polarimetry were obtained during the commissioning of GPI. In our broadband imaging polarimetry observations, we detect the disk only in total intensity and find asymmetries in the morphology of the disk between the southeast (SE) and northwest (NW) sides. The SE side of the disk exhibits a bump at 1'' (10 AU projected separation) that is three times more vertically extended and three times fainter in peak surface brightness than the NW side atmore » similar separations. This part of the disk is also vertically offset by 69 ± 30 mas to the northeast at 1'' when compared to the established disk midplane and is consistent with prior Atacama Large Millimeter/submillimeter Array and Hubble Space Telescope/Space Telescope Imaging Spectrograph observations. We see hints that the SE bump might be a result of detecting a horizontal sliver feature above the main disk that could be the disk backside. Alternatively, when including the morphology of the NW side, where the disk midplane is offset in the opposite direction ~50 mas between 0farcs4 and 1farcs2, the asymmetries suggest a warp-like feature. Using our integral field spectroscopy data to search for planets, we are 50% complete for ~4 MJup planets at 4 AU. Lastly, we detect a source, resolved only along the disk plane, that could either be a candidate planetary mass companion or a compact clump in the disk.« less
DOE Office of Scientific and Technical Information (OSTI.GOV)
Wang, Jason J.; Graham, James R.; De Rosa, Robert J.
We present Gemini Planet Imager (GPI) observations of AU Microscopii, a young M dwarf with an edge-on, dusty debris disk. Integral field spectroscopy and broadband imaging polarimetry were obtained during the commissioning of GPI. In our broadband imaging polarimetry observations, we detect the disk only in total intensity and find asymmetries in the morphology of the disk between the southeast (SE) and northwest (NW) sides. The SE side of the disk exhibits a bump at 1″ (10 AU projected separation) that is three times more vertically extended and three times fainter in peak surface brightness than the NW side atmore » similar separations. This part of the disk is also vertically offset by 69 ± 30 mas to the northeast at 1″ when compared to the established disk midplane and is consistent with prior Atacama Large Millimeter/submillimeter Array and Hubble Space Telescope/Space Telescope Imaging Spectrograph observations. We see hints that the SE bump might be a result of detecting a horizontal sliver feature above the main disk that could be the disk backside. Alternatively, when including the morphology of the NW side, where the disk midplane is offset in the opposite direction ∼50 mas between 0.″4 and 1.″2, the asymmetries suggest a warp-like feature. Using our integral field spectroscopy data to search for planets, we are 50% complete for ∼4 M{sub Jup} planets at 4 AU. We detect a source, resolved only along the disk plane, that could either be a candidate planetary mass companion or a compact clump in the disk.« less
Zhou, Jing; Li, Yan; Zahl, Percy; ...
2015-03-14
The morphology and electronic structure of vapor deposited 4,4'-biphenyldiisocyanide (BPDI) on a Au(111) surface were investigated using variable-temperature scanning tunneling microscopy (STM). When deposited at room temperature, BPDI molecules form one-dimensional molecular chains similar to that recently observed for the structurally related 1,4-phenyl diisocyanide (PDI). Compared to PDI, the longer periodicity for the BPDI molecular chains is consistent with the addition of a second phenyl ring and supports a structural model in which the BPDI molecules lie parallel to the surface and interconnected by Au-adatoms. The molecular chains are mostly aligned along the [110] direction of the Au(111) substrate, butmore » exhibit frequent changes in angle that are consistent with directions between fcc and hcp three-fold hollow sites. Dispersion-corrected density functional theory calculations for one-dimensional chains of BPDI molecules bound end-to-end via their isocyanide groups to Au-adatoms reproduce the observed periodicity of the chains and show that this morphology is energetically favored over upright binding with one free –NC group. The spatially resolved conductance (dI/dV) map for BPDI on Au(111) exhibits a feature centered at -0.67 eV below the Fermi level which are delocalized along the chain with maxima at the Au-adatom and biphenyl positions. This occupied resonant feature is close to that previously observed for the PDI in both photoemission and conductance measurements and is attributed to an occupied interfacial state resulting from BPDI-Au interactions« less
Singular regional brightening events on Titan as seen by Cassini/VIMS
NASA Astrophysics Data System (ADS)
Rodriguez, S.; Le Mouélic, S.; Barnes, J. W.; Rannou, P.; Sotin, C.; Brown, R. H.; Bow, J.; Vixie, G.; Cornet, T.; Bourgeois, O.; Narteau, C.; Courrech Du Pont, S.; Griffith, C. A.; Jaumann, R.; Stephan, K.; Buratti, B. J.; Clark, R. N.; Baines, K. H.; Nicholson, P. D.
2011-10-01
We present here the observation of intense brightening at Titan's tropics, very close to the equinox. These detections were conducted with the Visual and Infrared Mapping Spectrometer [8] (VIMS) onboard Cassini. Figure 1 presents the VIMS color composite images of the three individual events detected so far, observed during the Titan's flybys T56 (22 May 2009), T65 (13 January 2010) and T70 (21 June 2010). T56, T65 and T70 observations show an intense and transient brightening of large regions very close to the equator, which all appear spectrally and morphologically different from all previous observed surface features or atmospheric phenomena. These events share in particular a strong brightening at wavelengths greater than 2 μm (especially at 5 μm), making them spectrally distinct from the few large storms observed near the equator. We will discuss the possibility that these singular events may have occurred very close to the surface, having a very local origin. We will also discuss the possible implication of the equinoctial occurrence of such events for Titan's tropical climatology and their probable link with particular geological features at Titan's surface.
A Quantitative Framework for Flower Phenotyping in Cultivated Carnation (Dianthus caryophyllus L.)
Chacón, Borja; Ballester, Roberto; Birlanga, Virginia; Rolland-Lagan, Anne-Gaëlle; Pérez-Pérez, José Manuel
2013-01-01
Most important breeding goals in ornamental crops are plant appearance and flower characteristics where selection is visually performed on direct offspring of crossings. We developed an image analysis toolbox for the acquisition of flower and petal images from cultivated carnation (Dianthus caryophyllus L.) that was validated by a detailed analysis of flower and petal size and shape in 78 commercial cultivars of D. caryophyllus, including 55 standard, 22 spray and 1 pot carnation cultivars. Correlation analyses allowed us to reduce the number of parameters accounting for the observed variation in flower and petal morphology. Convexity was used as a descriptor for the level of serration in flowers and petals. We used a landmark-based approach that allowed us to identify eight main principal components (PCs) accounting for most of the variance observed in petal shape. The effect and the strength of these PCs in standard and spray carnation cultivars are consistent with shared underlying mechanisms involved in the morphological diversification of petals in both subpopulations. Our results also indicate that neighbor-joining trees built with morphological data might infer certain phylogenetic relationships among carnation cultivars. Based on estimated broad-sense heritability values for some flower and petal features, different genetic determinants shall modulate the responses of flower and petal morphology to environmental cues in this species. We believe our image analysis toolbox could allow capturing flower variation in other species of high ornamental value. PMID:24349209
STXM/C 1s-NEXAFS study of Eu(III) and Uranyl humic acid aggregates at different pH
NASA Astrophysics Data System (ADS)
Plaschke, M.; Rothe, J.; Denecke, M. A.; Geckeis, H.
2010-04-01
Humic acids (HA) are chemically heterogeneous and structurally ill-defined biopolymers which are able to bind traces of actinides or lanthanides. Due to their dimensions in the colloidal size range they may affect transport of these elements in aquatic systems. Eu(III)- and UO22+-HA aggregates have been investigated by Scanning Transmission X-ray Microscopy (STXM) and C 1s-NEXAFS under systematic variation of pH. In the Eu(III)- and UO22+-HA systems aggregate morphologies at near neutral pH were similar to those observed in previous studies: optically dense zones (high absorption at the carbon K-edge) are embedded in a matrix of less dense material. C 1s-NEXAFS signatures observed in the different zones, i.e., the intensity of the characteristic complexation feature previously experimentally described and recently theoretically characterized, strongly depends on sample pH. In the alkaline regime (pH 9) with added carbonate, co-precipitation of Eu(III)-carbonate (or ternary carbonate/(oxo)hydroxide complexes) with the Eu(III)-HA majority fraction is observed but Eu(III) binding to HA over carbonate in the dense zones seems to be favoured. The UO22+-HA system exhibits in alkaline solution more compact morphologies combined with a strong metal ion complexation effect in the NEXAFS. Eu(III) and UO22+ polyacrylic acid (PAA) aggregates used as HA model systems show similar spectral trends; these aggregates exhibit highly branched morphologies without segregation into zones with different NEXAFS signatures. The chemical environment such as pH or the type of metal cation strongly influences both HA aggregate morphologies and NEXAFS spectral signatures. These can, in turn, be used as indicators of the strength of lanthanide or actinide ion bound HA interaction.
Mokuwa, Alfred; Nuijten, Edwin; Okry, Florent; Teeken, Béla; Maat, Harro; Richards, Paul; Struik, Paul C
2014-01-01
We assessed the interplay of artificial and natural selection in rice adaptation in low-input farming systems in West Africa. Using 20 morphological traits and 176 molecular markers, 182 farmer varieties of rice (Oryza spp.) from 6 West African countries were characterized. Principal component analysis showed that the four botanical groups (Oryza sativa ssp. indica, O. sativa ssp. japonica, O. glaberrima, and interspecific farmer hybrids) exhibited different patterns of morphological diversity. Regarding O. glaberrima, morphological and molecular data were in greater conformity than for the other botanical groups. A clear difference in morphological features was observed between O. glaberrima rices from the Togo hills and those from the Upper Guinea Coast, and among O. glaberrima rices from the Upper Guinea Coast. For the other three groups such clear patterns were not observed. We argue that this is because genetic diversity is shaped by different environmental and socio-cultural selection pressures. For O. glaberrima, recent socio-cultural selection pressures seemed to restrict genetic diversity while this was not observed for the other botanical groups. We also show that O. glaberrima still plays an important role in the selection practices of farmers and resulting variety development pathways. This is particularly apparent in the case of interspecific farmer hybrids where a relationship was found between pericarp colour, panicle attitude and genetic diversity. Farmer varieties are the product of long and complex trajectories of selection governed by local human agency. In effect, rice varieties have emerged that are adapted to West African farming conditions through genotype × environment × society interactions. The diversity farmers maintain in their rice varieties is understood to be part of a risk-spreading strategy that also facilitates successful and often serendipitous variety innovations. We advocate, therefore, that farmers and farmer varieties should be more effectively involved in crop development.
Maat, Harro; Richards, Paul; Struik, Paul C.
2014-01-01
We assessed the interplay of artificial and natural selection in rice adaptation in low-input farming systems in West Africa. Using 20 morphological traits and 176 molecular markers, 182 farmer varieties of rice (Oryza spp.) from 6 West African countries were characterized. Principal component analysis showed that the four botanical groups (Oryza sativa ssp. indica, O. sativa ssp. japonica, O. glaberrima, and interspecific farmer hybrids) exhibited different patterns of morphological diversity. Regarding O. glaberrima, morphological and molecular data were in greater conformity than for the other botanical groups. A clear difference in morphological features was observed between O. glaberrima rices from the Togo hills and those from the Upper Guinea Coast, and among O. glaberrima rices from the Upper Guinea Coast. For the other three groups such clear patterns were not observed. We argue that this is because genetic diversity is shaped by different environmental and socio-cultural selection pressures. For O. glaberrima, recent socio-cultural selection pressures seemed to restrict genetic diversity while this was not observed for the other botanical groups. We also show that O. glaberrima still plays an important role in the selection practices of farmers and resulting variety development pathways. This is particularly apparent in the case of interspecific farmer hybrids where a relationship was found between pericarp colour, panicle attitude and genetic diversity. Farmer varieties are the product of long and complex trajectories of selection governed by local human agency. In effect, rice varieties have emerged that are adapted to West African farming conditions through genotype × environment × society interactions. The diversity farmers maintain in their rice varieties is understood to be part of a risk-spreading strategy that also facilitates successful and often serendipitous variety innovations. We advocate, therefore, that farmers and farmer varieties should be more effectively involved in crop development. PMID:24465809
Shahzad, Huma; Giribabu, Nelli; Sekaran, Muniandy
2015-01-01
Abstract Quercetin could have profound effects on uterine morphology and proliferation, which are known to be influenced by estrogen. This study investigated the effect of quercetin on these uterine parameters in the presence and in the absence of estrogen. Ovariectomized adult female rats received peanut oil, quercetin (10, 50, and 100 mg/kg/day), estrogen, or estrogen+quercetin (10, 50, or 100 mg/kg/day) treatment for 7 consecutive days. At the end of the treatment, uteri were harvested for histological and molecular biological analyses. Distribution of proliferative cell nuclear antigen (PCNA) protein in the uterus was observed by immunohistochemistry. Levels of expression of PCNA protein and mRNA in uterine tissue homogenates were determined by Western blotting and real-time polymerase chain reaction, respectively. Our findings indicated that administration of 10 mg/kg/day of quercetin either alone or with estrogen resulted in decreased uterine expression of PCNA protein and mRNA with the percentage of PCNA-positive cells in uterine luminal and glandular epithelia markedly reduced compared with estrogen-only treatment. Changes in uterine morphology were the opposite of changes observed following estrogen treatment. Treatment with 100 mg/kg/day of quercetin either alone or with estrogen resulted in elevated PCNA protein and mRNA expression. In addition, the percentages of PCNA-positive cells in the epithelia, which line the lumen and glands, were increased with morphological features mimicking changes that occur following estrogen treatment. Following 50 mg/kg/day quercetin treatment, the changes observed were in between those changes that occur following 10 and 100 mg/kg/day quercetin treatment. In conclusion, changes in uterine morphology and proliferation following 10 mg/kg/day quercetin treatment could be attributed to quercetin's antiestrogenic properties, while changes that occur following 100 mg/kg/day quercetin treatment could be attributed to quercetin's estrogenic properties. PMID:26135605
Micro-anatomical quantitative optical imaging: toward automated assessment of breast tissues.
Dobbs, Jessica L; Mueller, Jenna L; Krishnamurthy, Savitri; Shin, Dongsuk; Kuerer, Henry; Yang, Wei; Ramanujam, Nirmala; Richards-Kortum, Rebecca
2015-08-20
Pathologists currently diagnose breast lesions through histologic assessment, which requires fixation and tissue preparation. The diagnostic criteria used to classify breast lesions are qualitative and subjective, and inter-observer discordance has been shown to be a significant challenge in the diagnosis of selected breast lesions, particularly for borderline proliferative lesions. Thus, there is an opportunity to develop tools to rapidly visualize and quantitatively interpret breast tissue morphology for a variety of clinical applications. Toward this end, we acquired images of freshly excised breast tissue specimens from a total of 34 patients using confocal fluorescence microscopy and proflavine as a topical stain. We developed computerized algorithms to segment and quantify nuclear and ductal parameters that characterize breast architectural features. A total of 33 parameters were evaluated and used as input to develop a decision tree model to classify benign and malignant breast tissue. Benign features were classified in tissue specimens acquired from 30 patients and malignant features were classified in specimens from 22 patients. The decision tree model that achieved the highest accuracy for distinguishing between benign and malignant breast features used the following parameters: standard deviation of inter-nuclear distance and number of duct lumens. The model achieved 81 % sensitivity and 93 % specificity, corresponding to an area under the curve of 0.93 and an overall accuracy of 90 %. The model classified IDC and DCIS with 92 % and 96 % accuracy, respectively. The cross-validated model achieved 75 % sensitivity and 93 % specificity and an overall accuracy of 88 %. These results suggest that proflavine staining and confocal fluorescence microscopy combined with image analysis strategies to segment morphological features could potentially be used to quantitatively diagnose freshly obtained breast tissue at the point of care without the need for tissue preparation.
Resolving the Lophiostoma bipolare complex: Generic delimitations within Lophiostomataceae.
Hashimoto, A; Hirayama, K; Takahashi, H; Matsumura, M; Okada, G; Chen, C Y; Huang, J W; Kakishima, M; Ono, T; Tanaka, K
2018-06-01
Lophiostoma bipolare was taxonomically revised based on the morphological observations and phylogenetic analyses of molecular data from nuclear rDNA SSU-ITS-LSU, TUB , tef1 , and rpb2 genes. Twenty-nine strains were morphologically similar to Lo . bipolare . A total of 174 sequences were generated from the Lo . bipolare complex. Phylogenetic analyses based on TUB sequence revealed 11 distinct species within the Lo. bipolare complex. Morphological features of the ascospores and the anatomical structure of the ascomata from both field collections as well as axenic culture, which have been reported previously as variable features at intraspecific levels, were compared to evaluate the taxonomic reliability of these features. To clarify the generic position of the 11 species, phylogenetic analyses were done on SSU-ITS-LSU- tef1 - rpb2 gene sequences. The Lo . bipolare complex shared phylogenetic relationships with Pseudolophiostoma and Vaginatispora , and formed an additional five distinct clades from other members of Lophiostomataceae . According to its phylogenetic position, Lo. bipolare sensu stricto was distantly related to Lophiostoma s. str., and formed an independent clade within Lophiostomataceae. Lophiostoma bipolare s. str. could be distinguished from the other lophiostomataceous genera by the clypeus around the ostiolar neck and by the thin and uniformly thick peridium. A novel genus described as Lentistoma was established to accommodate this species, and the epitypification of Lentistoma bipolare (basionym: Massarina bipolaris ) was proposed. Other lineages of the Lo. bipolare complex could not be separated on the basis of the ascospore size and sheath variations, but were distinguished based on ascomatal features, such as the existence of the clypeus, brown hyphae surrounding the peridium, and the contexture of the peridium, which were stable indicators of generic boundaries in Lophiostomataceae . Four additional new genera with five new species were recognised based on these morphological differences: Crassiclypeus ( C . aquaticus ), Flabellascoma ( F . cycadicola and F . minimum ), Leptoparies ( Lep . palmarum ), and Pseudopaucispora ( Pseudop . brunneospora ). Three new species were added to Pseudolophiostoma ( Pseudol . cornisporum , Pseudol . obtusisporum , and Pseudol . tropicum ) and two new species were added to Vaginatispora ( V . amygdali and V . scabrispora ). The re-evaluation of the validity of several previously recognised genera resulted in the introduction of two new genera with new combinations for Lophiostoma pseudoarmatisporum as Parapaucispora pseudoarmatispora and Vaginatispora fuckelii as Neovaginatispora fuckelii .
2013-01-01
Background The taxonomic and phylogenetic relationships of the genus Phyllomedusa have been amply discussed. The marked morphological similarities among some species hamper the reliable identification of specimens and may often lead to their incorrect taxonomic classification on the sole basis of morphological traits. Phenotypic variation was observed among populations assigned to either P. azurea or P. hypochondrialis. In order to evaluate whether the variation observed in populations assigned to P. hypochondrialis is related to that in genotypes, a cytogenetic analysis was combined with phylogenetic inferences based on mitochondrial and nuclear sequences. Results The inter- and intra-population variation in the external morphology observed among the specimens analyzed in the present study do not reflect the phylogenetic relationships among populations. A monophyletic clade was recovered, grouping all the specimens identified as P. hypochondrialis and specimens assigned P. azurea from Minas Gerais state. This clade is characterized by conserved chromosomal morphology and a common C-banding pattern. Extensive variation in the nucleolar organizing region (NOR) was observed among populations, with four distinct NOR positions being recognized in the karyotypes. Intra-population polymorphism of the additional rDNA clusters observed in specimens from Barreiras, Bahia state, also highlights the marked genomic instability of the rDNA in the genome of this group. Based on the topology obtained in the phylogenetic analyses, the re-evaluation of the taxonomic status of the specimens from the southernmost population known in Brazil is recommended. Conclusions The results of this study support the need for a thorough revision of the phenotypic features used to discriminate P. azurea and P. hypochondrialis. The phylogenetic data presented here also contribute to an extension of the geographic range of P. hypochondrialis, which is known to occur in the Amazon basin and neighboring areas of the Cerrado savanna, where it may be sympatric with P. azurea, within contact zones. The misidentification of specimens may have led to inconsistencies in the original definition of the geographic range of P. azurea. The variability observed in the NOR of P. hypochondrialis reinforces the conclusion that these sites represent hotspots of rearrangement. Intraspecific variation in the location of these sites is the result of constant rearrangements that are not detected by classical cytogenetic methods or are traits of an ancestral, polymorphic karyotype, which would not be phylogenetically informative for this group. PMID:23937545
Mapping products of Titan's surface
Stephan, Katrin; Jaumann, Ralf; Karkoschka, Erich; Barnes, Jason W.; Tomasko, Martin G.; Turtle, Elizabeth P.; Le Corre, Lucille; Langhans, Mirjam; Le Mouelic, Stephane; Lorenz, Ralf D.; Perry, Jason; Brown, Robert H.; Lebreton, Jean-Pierre
2009-01-01
Remote sensing instruments aboard the Cassini spacecraft have been observed the surface of Titan globally in the infrared and radar wavelength ranges as well as locally by the Huygens instruments revealing a wealth of new morphological features indicating a geologically active surface. We present a summary of mapping products of Titan's surface derived from data of the remote sensing instruments onboard the Cassini spacecraft (ISS, VIMS, RADAR) as well as the Huygens probe (DISR) that were achieved during the nominal Cassini mission including an overview of Titan's recent nomenclature.
Textural evidence bearing on the origin of isolated olivine crystals in C2 carbonaceous chondrites
NASA Technical Reports Server (NTRS)
Richardson, S. M.; Mcsween, H. Y., Jr.
1978-01-01
In some cases the mechanical competence of chondrules in carbonaceous chondrites has been reduced by alteration of their mesostasis glass to friable phyllosilicate, providing a mechanism by which euhedral olivines can be separated from chondrules. Morphological features of isolate olivine grains found in carbonaceous chondrites are similar to those of olivine phenocrysts in chondrules. These observations suggest that the isolated olivine grains formed in chondrules, by crystallization from a liquid, rather than by condensation from a vapor.
Conventional MRI features for predicting the clinical outcome of patients with invasive placenta
Chen, Ting; Xu, Xiao-Quan; Shi, Hai-Bin; Yang, Zheng-Qiang; Zhou, Xin; Pan, Yi
2017-01-01
PURPOSE We aimed to evaluate whether morphologic magnetic resonance imaging (MRI) features could help to predict the maternal outcome after uterine artery embolization (UAE)-assisted cesarean section (CS) in patients with invasive placenta previa. METHODS We retrospectively reviewed the MRI data of 40 pregnant women who have undergone UAE-assisted cesarean section due to suspected high risk of massive hemorrhage caused by invasive placenta previa. Patients were divided into two groups based on the maternal outcome (good-outcome group: minor hemorrhage and uterus preserved; poor-outcome group: significant hemorrhage or emergency hysterectomy). Morphologic MRI features were compared between the two groups. Multivariate logistic regression analysis was used to identify the most valuable variables, and predictive value of the identified risk factor was determined. RESULTS Low signal intensity bands on T2-weighted imaging (P < 0.001), placenta percreta (P = 0.011), and placental cervical protrusion sign (P = 0.002) were more frequently observed in patients with poor outcome. Low signal intensity bands on T2-weighted imaging was the only significant predictor of poor maternal outcome in multivariate analysis (P = 0.020; odds ratio, 14.79), with 81.3% sensitivity and 84.3% specificity. CONCLUSION Low signal intensity bands on T2-weighted imaging might be a predictor of poor maternal outcome after UAE-assisted cesarean section in patients with invasive placenta previa. PMID:28345524
NASA Astrophysics Data System (ADS)
Garcia-Allende, P. Beatriz; Amygdalos, Iakovos; Dhanapala, Hiruni; Goldin, Robert D.; Hanna, George B.; Elson, Daniel S.
2012-01-01
Computer-aided diagnosis of ophthalmic diseases using optical coherence tomography (OCT) relies on the extraction of thickness and size measures from the OCT images, but such defined layers are usually not observed in emerging OCT applications aimed at "optical biopsy" such as pulmonology or gastroenterology. Mathematical methods such as Principal Component Analysis (PCA) or textural analyses including both spatial textural analysis derived from the two-dimensional discrete Fourier transform (DFT) and statistical texture analysis obtained independently from center-symmetric auto-correlation (CSAC) and spatial grey-level dependency matrices (SGLDM), as well as, quantitative measurements of the attenuation coefficient have been previously proposed to overcome this problem. We recently proposed an alternative approach consisting of a region segmentation according to the intensity variation along the vertical axis and a pure statistical technology for feature quantification. OCT images were first segmented in the axial direction in an automated manner according to intensity. Afterwards, a morphological analysis of the segmented OCT images was employed for quantifying the features that served for tissue classification. In this study, a PCA processing of the extracted features is accomplished to combine their discriminative power in a lower number of dimensions. Ready discrimination of gastrointestinal surgical specimens is attained demonstrating that the approach further surpasses the algorithms previously reported and is feasible for tissue classification in the clinical setting.
All Features Great and Small-the Potential Roles of the Baculum and Penile Spines in Mammals.
Orr, Teri J; Brennan, Patricia L R
2016-10-01
Mammalian penises are morphologically diverse, including a highly variable and taxonomically informative baculum (os penis), and variable penile spines, both of which are possessed by many-but not all-species. To understand the evolution of genital morphologies, as well as the potential role of both the baculum, and penile spines that directly interact with female reproductive tract, we undertook a comparative study of male penile spines and their relationship with the baculum across all mammalian orders. Specifically, we investigated several factors that may explain the presence or absence of penile spines in mammals, including mating system, risk of sperm competition, female reproductive physiology, presence and width of the baculum, and phylogenetic history. We observed that the presence of both the baculum and penile spines is correlated with residual testes size, suggesting a potential role in sexual selection for these traits. We found no association between the presence of spines and mating system, or with the presence/width of the baculum, although relative testes mass was marginally associated with baculum width. We found no relationship between baculum presence or width and mating system. We also noted that spines presence or absence have an order-level distribution, and clear phylogenetic patterns of distribution across mammals. It is likely that spine morphology and distribution, not just presence, play an important role in genital evolution in mammals, but these features are poorly described in most groups. Quantitative data collection in most mammalian taxa would be useful to further elucidate the evolution of the complex genital morphology of this group. © The Author 2016. Published by Oxford University Press on behalf of the Society for Integrative and Comparative Biology. All rights reserved. For permissions please email: journals.permissions@oup.com.
A Genome-Wide Association Study Identifies Five Loci Influencing Facial Morphology in Europeans
Liu, Fan; van der Lijn, Fedde; Schurmann, Claudia; Zhu, Gu; Chakravarty, M. Mallar; Hysi, Pirro G.; Wollstein, Andreas; Lao, Oscar; de Bruijne, Marleen; Ikram, M. Arfan; van der Lugt, Aad; Rivadeneira, Fernando; Uitterlinden, André G.; Hofman, Albert; Niessen, Wiro J.; Homuth, Georg; de Zubicaray, Greig; McMahon, Katie L.; Thompson, Paul M.; Daboul, Amro; Puls, Ralf; Hegenscheid, Katrin; Bevan, Liisa; Pausova, Zdenka; Medland, Sarah E.; Montgomery, Grant W.; Wright, Margaret J.; Wicking, Carol; Boehringer, Stefan; Spector, Timothy D.; Paus, Tomáš; Martin, Nicholas G.; Biffar, Reiner; Kayser, Manfred
2012-01-01
Inter-individual variation in facial shape is one of the most noticeable phenotypes in humans, and it is clearly under genetic regulation; however, almost nothing is known about the genetic basis of normal human facial morphology. We therefore conducted a genome-wide association study for facial shape phenotypes in multiple discovery and replication cohorts, considering almost ten thousand individuals of European descent from several countries. Phenotyping of facial shape features was based on landmark data obtained from three-dimensional head magnetic resonance images (MRIs) and two-dimensional portrait images. We identified five independent genetic loci associated with different facial phenotypes, suggesting the involvement of five candidate genes—PRDM16, PAX3, TP63, C5orf50, and COL17A1—in the determination of the human face. Three of them have been implicated previously in vertebrate craniofacial development and disease, and the remaining two genes potentially represent novel players in the molecular networks governing facial development. Our finding at PAX3 influencing the position of the nasion replicates a recent GWAS of facial features. In addition to the reported GWA findings, we established links between common DNA variants previously associated with NSCL/P at 2p21, 8q24, 13q31, and 17q22 and normal facial-shape variations based on a candidate gene approach. Overall our study implies that DNA variants in genes essential for craniofacial development contribute with relatively small effect size to the spectrum of normal variation in human facial morphology. This observation has important consequences for future studies aiming to identify more genes involved in the human facial morphology, as well as for potential applications of DNA prediction of facial shape such as in future forensic applications. PMID:23028347
Ekdale, Eric G; Berta, Annalisa; Deméré, Thomas A
2011-01-01
Anatomical comparisons of the ear region of baleen whales (Mysticeti) are provided through detailed osteological descriptions and high-resolution photographs of the petrotympanic complex (tympanic bulla and petrosal bone) of all extant species of mysticete cetaceans. Salient morphological features are illustrated and identified, including overall shape of the bulla, size of the conical process of the bulla, morphology of the promontorium, and the size and shape of the anterior process of the petrosal. We place our comparative osteological observations into a phylogenetic context in order to initiate an exploration into petrotympanic evolution within Mysticeti. The morphology of the petrotympanic complex is diagnostic for individual species of baleen whale (e.g., sigmoid and conical processes positioned at midline of bulla in Balaenoptera musculus; confluence of fenestra cochleae and perilymphatic foramen in Eschrichtius robustus), and several mysticete clades are united by derived characteristics. Balaenids and neobalaenids share derived features of the bulla, such as a rhomboid shape and a reduced anterior lobe (swelling) in ventral aspect, and eschrichtiids share derived morphologies of the petrosal with balaenopterids, including loss of a medial promontory groove and dorsomedial elongation of the promontorium. Monophyly of Balaenoidea (Balaenidae and Neobalaenidae) and Balaenopteroidea (Balaenopteridae and Eschrichtiidae) was recovered in phylogenetic analyses utilizing data exclusively from the petrotympanic complex. This study fills a major gap in our knowledge of the complex structures of the mysticete petrotympanic complex, which is an important anatomical region for the interpretation of the evolutionary history of mammals. In addition, we introduce a novel body of phylogenetically informative characters from the ear region of mysticetes. Our detailed anatomical descriptions, illustrations, and comparisons provide valuable data for current and future studies on the phylogenetic relationships, evolution, and auditory physiology of mysticetes and other cetaceans throughout Earth's history.
Average combination difference morphological filters for fault feature extraction of bearing
NASA Astrophysics Data System (ADS)
Lv, Jingxiang; Yu, Jianbo
2018-02-01
In order to extract impulse components from vibration signals with much noise and harmonics, a new morphological filter called average combination difference morphological filter (ACDIF) is proposed in this paper. ACDIF constructs firstly several new combination difference (CDIF) operators, and then integrates the best two CDIFs as the final morphological filter. This design scheme enables ACIDF to extract positive and negative impacts existing in vibration signals to enhance accuracy of bearing fault diagnosis. The length of structure element (SE) that affects the performance of ACDIF is determined adaptively by a new indicator called Teager energy kurtosis (TEK). TEK further improves the effectiveness of ACDIF for fault feature extraction. Experimental results on the simulation and bearing vibration signals demonstrate that ACDIF can effectively suppress noise and extract periodic impulses from bearing vibration signals.
New Evidence for Morphological Errors in Deep Dyslexia
ERIC Educational Resources Information Center
Rastle, Kathleen; Tyler, Lorraine K.; Marslen-Wilson, William
2006-01-01
Morphological errors in reading aloud (e.g., "sexist" [right arrow] "sexy") are a central feature of the symptom-complex known as deep dyslexia, and have historically been viewed as evidence that representations at some level of the reading system are morphologically structured. However, it has been proposed (Funnell, 1987) that morphological…
Song, Keun Man; Kim, Do-Hyun; Kim, Jong-Min; Cho, Chu-Young; Choi, Jehyuk; Kim, Kahee; Park, Jinsup; Kim, Hogyoug
2017-06-02
We demonstrated an InGaN/GaN-based, monolithic, white light-emitting diode (LED) without phosphors by using morphology-controlled active layers formed on multi-facet GaN templates containing polar and semipolar surfaces. The nanostructured surface morphology was controlled by changing the growth time, and distinct multiple photoluminescence peaks were observed at 360, 460, and 560 nm; these features were caused by InGaN/GaN-based multiple quantum wells (MQWs) on the nanostructured facets. The origin of each multi-peak was related to the different indium (In) compositions in the different planes of the quantum wells grown on the nanostructured GaN. The emitting units of MQWs in the LED structures were continuously connected, which is different from other GaN-based nanorod or nanowire LEDs. Therefore, the suggested structure had a larger active area. From the electroluminescence spectrum of the fabricated LED, monolithic white light emission with CIE color coordinates of x = 0.306 and y = 0.333 was achieved via multi-facet control combined with morphology control of the metal organic chemical vapor deposition-selective area growth of InGaN/GaN MQWs.
NASA Astrophysics Data System (ADS)
Song, Keun Man; Kim, Do-Hyun; Kim, Jong-Min; Cho, Chu-Young; Choi, Jehyuk; Kim, Kahee; Park, Jinsup; Kim, Hogyoug
2017-06-01
We demonstrated an InGaN/GaN-based, monolithic, white light-emitting diode (LED) without phosphors by using morphology-controlled active layers formed on multi-facet GaN templates containing polar and semipolar surfaces. The nanostructured surface morphology was controlled by changing the growth time, and distinct multiple photoluminescence peaks were observed at 360, 460, and 560 nm; these features were caused by InGaN/GaN-based multiple quantum wells (MQWs) on the nanostructured facets. The origin of each multi-peak was related to the different indium (In) compositions in the different planes of the quantum wells grown on the nanostructured GaN. The emitting units of MQWs in the LED structures were continuously connected, which is different from other GaN-based nanorod or nanowire LEDs. Therefore, the suggested structure had a larger active area. From the electroluminescence spectrum of the fabricated LED, monolithic white light emission with CIE color coordinates of x = 0.306 and y = 0.333 was achieved via multi-facet control combined with morphology control of the metal organic chemical vapor deposition-selective area growth of InGaN/GaN MQWs.
The application of LiDAR to investigate foredune morphology and vegetation
NASA Astrophysics Data System (ADS)
Doyle, Thomas B.; Woodroffe, Colin D.
2018-02-01
LiDAR (Light Detection and Ranging) has been used to investigate coastal landform morphology, evolution, and change for almost a decade. Repeated airborne LiDAR surveys can provide the scientific community with significant observations of how shorelines have evolved, which may then enable forecasts of future patterns of change. However, there have been few studies that have considered the application of this new technology to the specific study of foredune morphology and vegetation. The accuracy and appropriateness of airborne LiDAR needs to be assessed, particularly where the density of vegetation may obscure the underlying topography, prior to interpreting derived geomorphic features. This study: i) tests the vertical accuracy of airborne LiDAR in 37 foredune systems along the coast of south-eastern Australia, and ii) demonstrates that it can be used to describe foredune morphology and vegetation in considerable detail. There was a strong correlation between the remotely-sensed LiDAR-derived elevation and field topographic and vegetation surveys (R2 = 0.96). A protocol for obtaining foredune geomorphic and botanical parameters is described. It enables widespread biogeomorphic characterisation along coasts for which LiDAR data is available, which can benefit both coastal managers and researchers alike.
Karyological features of wild and cultivated forms of myrtle (Myrtus communis, Myrtaceae).
Serçe, S; Ekbiç, E; Suda, J; Gündüz, K; Kiyga, Y
2010-03-09
Myrtle is an evergreen shrub or small tree widespread throughout the Mediterranean region. In Turkey, both cultivated and wild forms, differing in plant and fruit size and fruit composition, can be found. These differences may have resulted from the domestication of the cultivated form over a long period of time. We investigated whether wild and cultivated forms of myrtle differ in karyological features (i.e., number of somatic chromosomes and relative genome size). We sampled two wild forms and six cultivated types of myrtle. All the samples had the same chromosome number (2n = 2x = 22). The results were confirmed by 4',6-diamidino-2-phenylindole (DAPI) flow cytometry. Only negligible variation (approximately 3%) in relative fluorescence intensity was observed among the different myrtle accessions, with wild genotypes having the smallest values. We concluded that despite considerable morphological differentiation, cultivated and wild myrtle genotypes in Turkey have similar karyological features.
NASA Astrophysics Data System (ADS)
Davis, Benjamin L.; Berrier, J. C.; Shields, D. W.; Kennefick, J.; Kennefick, D.; Seigar, M. S.; Lacy, C. H. S.; Puerari, I.
2012-01-01
A logarithmic spiral is a prominent feature appearing in a majority of observed galaxies. This feature has long been associated with the traditional Hubble classification scheme, but historical quotes of pitch angle of spiral galaxies have been almost exclusively qualitative. We have developed a methodology, utilizing Two-Dimensional Fast Fourier Transformations of images of spiral galaxies, in order to isolate and measure the pitch angles of their spiral arms. Our technique provides a quantitative way to measure this morphological feature. This will allow the precise comparison of spiral galaxy evolution to other galactic parameters and test spiral arm genesis theories. In this work, we detail our image processing and analysis of spiral galaxy images and discuss the robustness of our analysis techniques. The authors gratefully acknowledge support for this work from NASA Grant NNX08AW03A.
NASA Astrophysics Data System (ADS)
Anderson, K.; Lundsten, E. M.; Caress, D. W.; Thomas, H. J.; Paull, C. K.; Maier, K. L.; Gales, J. A.; Gwiazda, R.; Talling, P.; Xu, J.; Parsons, D. R.
2017-12-01
The Coordinated Canyon Experiment (CCE), a multi-institutional collaboration effort, was designed to monitor the passage of sediment density flows along the axis of Monterey Canyon, offshore California, between 200 and 1850 m water depth. An array of moorings and sensors were deployed for three 6-month periods from October 2015 to April 2017. Aligned with the CCE deployments, repeat high-resolution multibeam bathymetric surveys of the Monterey Canyon floor were conducted with a mapping AUV (Autonomous Underwater Vehicle). The AUV carried a Reson 7125 multibeam echosounder (vertical precision of 0.15 m and horizontal resolution of 1.0 m). An inertial navigation system combined with a Doppler velocity logger allowed the AUV to fly pre-programmed grids at 3 knots, while maintaining an altitude of 50 m above the seafloor, to obtain a nominal line spacing of 130 m. The floor and lower flanks of the canyon between 200 to 540 m and 1350 to 1880 m water depths were mapped six times during the CCE. These repeat maps are subtracted to create bathymetry difference grids to show morphological change. Coupling the sensor observations with the bathymetric surveys, the CCE successfully documented sediment density flow events as well as the associated changes in seafloor morphology. Between repeat surveys, three sediment density flow events reached the lower canyon, extending to at least 1850 m water depth. On January 15, 2016, a particularly large density flow traveled more than 50 km down Monterey Canyon. Unlike in the upper canyon where this event caused wholesale reorganization of geomorphological features, changes to the lower canyon morphology involved a more moderate re-sculpting of the features. The effect of a sediment density flow of known magnitude and duration on the seafloor morphology has never been documented in a deep-sea setting before.
The cranial anatomy of the neornithischian dinosaur Thescelosaurus neglectus
2014-01-01
Though the dinosaur Thescelosaurus neglectus was first described in 1913 and is known from the relatively fossiliferous Lance and Hell Creek formations in the Western Interior Basin of North America, the cranial anatomy of this species remains poorly understood. The only cranial material confidently referred to this species are three fragmentary bones preserved with the paratype, hindering attempts to understand the systematic relationships of this taxon within Neornithischia. Here the cranial anatomy of T. neglectus is fully described for the first time based on two specimens that include well-preserved cranial material (NCSM 15728 and TLAM.BA.2014.027.0001). Visual inspection of exposed cranial elements of these specimens is supplemented by detailed CT data from NCSM 15728 that enabled the examination of otherwise unexposed surfaces, facilitating a complete description of the cranial anatomy of this species. The skull of T. neglectus displays a unique combination of plesiomorphic and apomorphic traits. The premaxillary and ‘cheek’ tooth morphologies are relatively derived, though less so than the condition seen in basal iguanodontians, suggesting that the high tooth count present in the premaxillae, maxillae, and dentaries may be related to the extreme elongation of the skull of this species rather than a retention of the plesiomorphic condition. The morphology of the braincase most closely resembles the iguanodontians Dryosaurus and Dysalotosaurus, especially with regard to the morphology of the prootic. One autapomorphic feature is recognized for the first time, along with several additional cranial features that differentiate this species from the closely related and contemporaneous Thescelosaurus assiniboiensis. Published phylogenetic hypotheses of neornithischian dinosaur relationships often differ in the placement of the North American taxon Parksosaurus, with some recovering a close relationship with Thescelosaurus and others with the South American taxon Gasparinisaura, but never both at the same time. The new morphological observations presented herein, combined with re-examination of the holotype of Parksosaurus, suggest that Parksosaurus shares a closer relationship with Thescelosaurus than with Gasparinisaura, and that many of the features previously cited to support a relationship with the latter taxon are either also present in Thescelosaurus, are artifacts of preservation, or are the result of incomplete preparation and inaccurate interpretation of specimens. Additionally, the overall morphology of the skull and lower jaws of both Thescelosaurus and Parksosaurus also closely resemble the Asian taxa Changchunsaurus and Haya, though the interrelationships of these taxa have yet to be tested in a phylogenetic analysis that includes these new morphological data for T. neglectus. PMID:25405076
De Smedt, L; Lemahieu, J; Palmans, S; Govaere, O; Tousseyn, T; Van Cutsem, E; Prenen, H; Tejpar, S; Spaepen, M; Matthijs, G; Decaestecker, C; Moles Lopez, X; Demetter, P; Salmon, I; Sagaert, X
2015-07-28
Microsatellite instability (MSI) accounts for 15% of all colorectal tumours. Several specific clinicopathologicals (e.g., preference for the proximal colon over the distal colon, improved prognosis and altered response to chemotherapeutics) are described for this subset of tumours. This study aimed to analyse morphological, inflammatory and angiogenic features of MSI vs microsatellite stable (MSS) tumours. Twenty-seven MSS and 29 MSI, TNM stage matched, colorectal tumours were selected from the archive of the Department of Pathology, UZ Leuven. Morphology was analysed on haematoxylin-eosin sections. Immunohistochemistry for CD3, CD4, CD8, CD20 and CD68 was used to map tumour infiltration in both a digital and traditional microscope-based manner for all distinct morphological components of the tumour. CD31 immunostains were performed to assess angiogenesis. Morphological tumour heterogeneity was a marked feature of MSI tumours, occurring in 53% of the cases as compared with 11% of the MSS tumours (P<0.001). Digital immune quantification showed an increased number of tumour-infiltrating cytotoxic T-lymphocytes (CD8+) in MSI compared with MSS tumours for both the tumour (P=0.02) and peritumoural area (P=0.03). Traditional microscope-based quantification confirmed these results (P<0.001 for both) and, in addition, revealed large numbers of CD68+ macrophages in the peritumoural area of MSI cancers (P=0.001). Moreover, traditional microscope-based analysis was able to distinguish between lymphocytes directly infiltrating the tumoural glands (intra-epithelial) and those infiltrating only the neoplastic stroma around the glands (intratumoural). Quantification showed high numbers of intra-epithelial CD3+, CD4+, CD8+, CD20+ and CD68+ cells in MSI compared with MSS cancers (P<0.001, P=0.01, P<0.001, P<0.001 and P=0.006, respectively). Higher microvessel density (MVD) was observed in MSI tumours compared with their MSS counterpart. Mixed morphology, reflecting tumour heterogeneity, is an important feature of MSI tumours and may have both diagnostic and therapeutic impact. The inflammatory reaction also presented with significant differences in MSI vs MSS colorectal tumours. MSI cancers showed mainly infiltration by cytotoxic T-cells in both the tumour and the close border around the tumour, as well as increased intra-epithelial infiltration in contrast to MSS tumours. The type of immune cell and the compartment it resides in (intratumoural or intra-epithelial) depend both on MSI status and morphology. Finally, MSI tumours showed a higher angiogenic capacity represented by an increased MVD, hinting for possible therapeutic consequences.
Variable features on Mars - Preliminary Mariner 9 television results.
NASA Technical Reports Server (NTRS)
Sagan, C.; Veverka, J.; Fox, P.; Dubisch, R.; Lederberg, J.; Levinthal, E.; Quam, L.; Tucker, R.; Pollack, J. B.; Smith, B. A.
1972-01-01
Systematic Mariner 9 photography of a range of Martian surface features, observed with all three photometric angles approximately invariant, reveals three general categories of albedo variations: (1) an essentially uniform contrast enhancement due to the dissipation of the dust storm; (2) the appearance of splotches, irregular dark markings at least partially related to topography; and (3) the development of both bright and dark linear streaks, generally emanating from craters. Some splotches and streaks vary on characteristic timescales of about two weeks; they have characteristic dimensions of kilometers to tens of kilometers. The morphology and variability of streaks and splotches, and the resolution of at least one splotch into an extensive dune system, implicate windblown dust as the principal agent of Martian albedo differences and variability.
NASA Astrophysics Data System (ADS)
Li, Yifan; Liang, Xihui; Lin, Jianhui; Chen, Yuejian; Liu, Jianxin
2018-02-01
This paper presents a novel signal processing scheme, feature selection based multi-scale morphological filter (MMF), for train axle bearing fault detection. In this scheme, more than 30 feature indicators of vibration signals are calculated for axle bearings with different conditions and the features which can reflect fault characteristics more effectively and representatively are selected using the max-relevance and min-redundancy principle. Then, a filtering scale selection approach for MMF based on feature selection and grey relational analysis is proposed. The feature selection based MMF method is tested on diagnosis of artificially created damages of rolling bearings of railway trains. Experimental results show that the proposed method has a superior performance in extracting fault features of defective train axle bearings. In addition, comparisons are performed with the kurtosis criterion based MMF and the spectral kurtosis criterion based MMF. The proposed feature selection based MMF method outperforms these two methods in detection of train axle bearing faults.
Super-Keplerian Motions in the AU Mic Circumstellar Debris System
NASA Astrophysics Data System (ADS)
Wisniewski, John
2017-08-01
We found enigmatic, few-au-scale features in spatially resolved near-IR scattered light observations of the AU Mic debris disk system obtained with VLT/SPHERE in 2014. We recovered these structures in re-analysis of HST/STIS imagery from 2010/2011, and discovered that they are moving away from the star at super-Keplerian speeds, possibly escaping the system. To-date, these are the only moving features seen in resolved imagery of debris disks. To help diagnose the origin of this phenomenon and in concert with multi-wavelength diagnostics being pursued with other facilities, we propose to use 12 orbits of HST/STIS to re-image the AU Mic scattered light disk from 0.2 (2 au) to 13 (130 au) 8 years after the previous epoch of HST/STIS imagery. HST/STIS provides the only means to trace the motion of structures that have already moved outside the FOV of ground-based extreme-AO imagers, the best means to accurately diagnose the morphological and kinematic evolution of these moving features, and the best means to trace the evolution of small grains in the system. Our optical STIS coronagraphy observations are critically needed to establish the locations and shapes of the blobs, establish their optical fluxes at high photometric fidelity, and therefore enable (IR - optical) colors of disk features to be measured in JWST's cycle-1, using NIRCAM's and MIRI's coronagraphs. These data will constrain the grain size distribution, hence mass, of the moving features and by extension the magnitude of the force that is expelling the features, enabling us to test whether mechanisms like the stellar wind or coronal-mass ejections are responsible for the newly observed phenomenon.
NASA Technical Reports Server (NTRS)
Collins, A.; de Wet, A.; Bleacher, J.; Schierl, Z.; Schwans, B.
2012-01-01
The origin of sinuous channels on the flanks of the Tharsis volcanoes on Mars is debated among planetary scientists. Some argue a volcanic genesis [1] while others have suggested a fluvial basis [2-4]. The majority of the studies thus far have focused on channels on the rift apron of Ascraeus Mons. Here, however, we broadly examine the channels on the rift apron of Pavonis Mons and compare them with those studied channels around Ascraeus. We compare the morphologies of features from both of these volcanoes with similar features of known volcanic origin on the island of Hawai i. We show that the morphologies between these two volcanoes in the Tharsis province are very similar and were likely formed by comparable processes, as previous authors have suggested [5]. We show that, although the morphologies of many of the channels around these volcanoes show some parallels to terrestrial fluvial systems, these morphologies can also be formed by volcanic processes. The context of these features suggests that volcanic processes were the more likely cause of these channels.
NASA Technical Reports Server (NTRS)
Rao, P. V.; Buckley, D. H.
1983-01-01
The erosion characteristics of aluminum cylinders sand-blasted with both spherical and angular erodent particles were studied and compared with results from previously studied flat surfaces. The cylindrical results are discussed with respect to impact conditions. The relationship between erosion rate and pit morphology (width, depth, and width to depth ratio) is established. The aspects of (1) erosion rate versus time curves on cylindrical surfaces; (2) long-term exposures; and (3) erosion rate versus time curves with spherical and angular particles are presented. The erosion morphology and characteristics of aluminum surfaces with pre-existing circular cylindrical and conical holes of different sizes were examined using weight loss measurements, scanning electron microscopy, a profilometer, and a depth gage. The morphological features (radial and concentric rings) are discussed with reference to flat surfaces, and the erosion features with spherical microglass beads. The similarities and differences of erosion and morphological features are highlighted. The erosion versus time curves of various shapes of holes are discussed and are compared with those of a flat surface. The erosion process at slits is considered.
Kong, Lingtao; Chen, Kaiyuan; Womer, Fay; Jiang, Wenyan; Luo, Xingguang; Driesen, Naomi; Liu, Jie; Blumberg, Hilary; Tang, Yanqing; Xu, Ke; Wang, Fei
2013-06-01
Sex differences are observed in both epidemiological and clinical aspects of major depressive disorder (MDD). The cortico-limbic-striatal neural system, including the prefrontal cortex, amygdala, hippocampus, and striatum, have shown sexually dimorphic morphological features and have been implicated in the dysfunctional regulation of mood and emotion in MDD. In this study, we utilized a whole-brain, voxel-based approach to examine sex differences in the regional distribution of gray matter (GM) morphological abnormalities in medication-naïve participants with MDD. Participants included 29 medication-naïve individuals with MDD (16 females and 13 males) and 33 healthy controls (HC) (17 females and 16 males). Gray matter morphology of the cortico-limbic-striatal neural system was examined using voxel-based morphometry analyzes of high-resolution structural magnetic resonance imaging scans. The main effect of diagnosis and interaction effect of diagnosis by sex on GM morphology were statistically significant (p < 0.05, corrected) in the left ventral prefrontal cortex, right amygdala, right hippocampus and bilateral caudate when comparing the MDD and HC groups. Posthoc analyzes showed that females with MDD had significant GM decreases in limbic regions (p < 0.05, corrected), compared to female HC; while males with MDD demonstrated significant GM reduction in striatal regions, (p < 0.05, corrected), compared to HC males. The observed sex-related patterns of abnormalities within the cortico-limbic-strial neural system, such as predominant prefrontal-limbic abnormalities in MDD females vs. predominant prefrontal-striatal abnormalities in MDD males, suggest differences in neural circuitry that may mediate sex differences in the clinical presentation of MDD and potential targets for sex-differentiated treatment of the disorder. Copyright © 2013 Elsevier Ltd. All rights reserved.
Douaihy, Bouchra; Sobierajska, Karolina; Jasińska, Anna Katarzyna; Boratyńska, Krystyna; Ok, Tolga; Romo, Angel; Machon, Nathalie; Didukh, Yakiv; Bou Dagher-Kharrat, Magda; Boratyński, Adam
2012-01-01
Background and aims Juniperus excelsa M.-Bieb. is a major forest element in the mountains of the eastern part of Mediterranean and sub-Mediterranean regions. This study comprises the first morphological investigation covering a large part of the geographical range of J. excelsa and aims to verify the congruency between the morphological results and molecular results of a previous study. Methodology We studied 14 populations sampled from Greece, Cyprus, Ukraine, Turkey and Lebanon, 11 of which have previously been investigated using molecular markers. Three hundred and ninety-four individuals of J. excelsa were examined using nine biometric features characterizing cones, seeds and shoots, and eight derived ratios. Statistical analyses were conducted in order to evaluate the intra- and inter-population morphological variability. Principal results The level of intra-population variability observed did not show any geographical trends. The total variation mostly depended on the ratios of cone diameter/seed width and seed width/seed length. The discrimination analysis, the Ward agglomeration method and barrier analysis results showed a separation of the sampled populations into three main clusters. These results confirmed, in part, the geographical differentiation revealed by molecular markers with a lower level of differentiation and a less clear geographical pattern. The most differentiated populations using both markers corresponded to old, isolated populations in the high altitudes of Lebanon (>2000 m). Moreover, a separation of the northern Turkish population from the southern Turkish populations was observed using both markers. Conclusions Morphological variation together with genetic and biogeographic studies make an effective tool for detecting relict plant populations and also populations subjected to more intensive selection. PMID:22822421
Souder, H.C.; McCloskey, B.; Hallock, P.; Byrne, R.
2010-01-01
Archived specimens of Archaias angulatus collected live at a depth of < 2. m in John Pennekamp Coral Reef State Park, Key Largo, Florida, in June, September and December 1982, and March 1983, were compared to specimens collected live from the same site and months in 2006-07. Shells were examined using light microscopy for anomalous features, which were then documented using scanning electron microscopy. Seven different types of morphological abnormalities and five different surface texture anomalies were observed. Physical abnormalities included profoundly deformed, curled, asymmetrical, and uncoiled shells, irregular suture lines, surface protrusions, and breakage/repair. Textural anomalies observed were surface pits, dissolution features, microborings, microbial biofilms, and the presence of epibionts including bryzoans, cyanobacteria and foraminifers. The same kinds of features were found in this A. angulatus population in both 1982-83 collections and 2006-07 collections. Within-date variability was higher in specimens collected in 1982-83, while between-date variability was higher in 2006-07; overall the range of variability was similar. Given that the site was originally chosen for study because these foraminifers were so abundant, the lack of significant change indicates that the variability of the geochemical habitat is still within the range that A. angulatus can thrive. ?? 2010.
NASA Astrophysics Data System (ADS)
Pasquato, Mario; Chung, Chul
2016-05-01
Context. Machine-learning (ML) solves problems by learning patterns from data with limited or no human guidance. In astronomy, ML is mainly applied to large observational datasets, e.g. for morphological galaxy classification. Aims: We apply ML to gravitational N-body simulations of star clusters that are either formed by merging two progenitors or evolved in isolation, planning to later identify globular clusters (GCs) that may have a history of merging from observational data. Methods: We create mock-observations from simulated GCs, from which we measure a set of parameters (also called features in the machine-learning field). After carrying out dimensionality reduction on the feature space, the resulting datapoints are fed in to various classification algorithms. Using repeated random subsampling validation, we check whether the groups identified by the algorithms correspond to the underlying physical distinction between mergers and monolithically evolved simulations. Results: The three algorithms we considered (C5.0 trees, k-nearest neighbour, and support-vector machines) all achieve a test misclassification rate of about 10% without parameter tuning, with support-vector machines slightly outperforming the others. The first principal component of feature space correlates with cluster concentration. If we exclude it from the regression, the performance of the algorithms is only slightly reduced.
Planetary geological studies. [MARS crater morphology and ejecta deposit topography
NASA Technical Reports Server (NTRS)
Blasius, K. R.
1981-01-01
A global data base was assembled for the study of Mars crater ejecta morphology. The craters were classified as to morhology using individual photographic prints of Viking orbiter frames. Positional and scale information were derived by fitting digitized mosaic coordinates to lattitude-longitude coordinates of surface features from the Mars geodetic control net and feature coordinates from the U.S.G.S. series of 1:5,00,000 scale shaded relief maps. Crater morphology characteristics recorded are of two classes - attributes of each ejecta deposit and other crater charactersitics. Preliminary efforts to check the data base with findings of other workers are described.
Different evolutionary pathways underlie the morphology of wrist bones in hominoids
2013-01-01
Background The hominoid wrist has been a focus of numerous morphological analyses that aim to better understand long-standing questions about the evolution of human and hominoid hand use. However, these same analyses also suggest various scenarios of complex and mosaic patterns of morphological evolution within the wrist and potentially multiple instances of homoplasy that would benefit from require formal analysis within a phylogenetic context. We identify morphological features that principally characterize primate – and, in particular, hominoid (apes, including humans) - wrist evolution and reveal the rate, process and evolutionary timing of patterns of morphological change on individual branches of the primate tree of life. Linear morphological variables of five wrist bones – the scaphoid, lunate, triquetrum, capitate and hamate – are analyzed in a diverse sample of extant hominoids (12 species, 332 specimens), Old World (8 species, 43 specimens) and New World (4 species, 26 specimens) monkeys, fossil Miocene apes (8 species, 20 specimens) and Plio-Pleistocene hominins (8 species, 18 specimens). Result Results reveal a combination of parallel and synapomorphic morphology within haplorrhines, and especially within hominoids, across individual wrist bones. Similar morphology of some wrist bones reflects locomotor behaviour shared between clades (scaphoid, triquetrum and capitate) while others (lunate and hamate) indicate clade-specific synapomorphic morphology. Overall, hominoids show increased variation in wrist bone morphology compared with other primate clades, supporting previous analyses, and demonstrate several occurrences of parallel evolution, particularly between orangutans and hylobatids, and among hominines (extant African apes, humans and fossil hominins). Conclusions Our analyses indicate that different evolutionary processes can underlie the evolution of a single anatomical unit (the wrist) to produce diversity in functional and morphological adaptations across individual wrist bones. These results exemplify a degree of evolutionary and functional independence across different wrist bones, the potential evolvability of skeletal morphology, and help to contextualize the postcranial mosaicism observed in the hominin fossil record. PMID:24148262
Liu, Bo; Wu, Huayi; Wang, Yandong; Liu, Wenming
2015-01-01
Main road features extracted from remotely sensed imagery play an important role in many civilian and military applications, such as updating Geographic Information System (GIS) databases, urban structure analysis, spatial data matching and road navigation. Current methods for road feature extraction from high-resolution imagery are typically based on threshold value segmentation. It is difficult however, to completely separate road features from the background. We present a new method for extracting main roads from high-resolution grayscale imagery based on directional mathematical morphology and prior knowledge obtained from the Volunteered Geographic Information found in the OpenStreetMap. The two salient steps in this strategy are: (1) using directional mathematical morphology to enhance the contrast between roads and non-roads; (2) using OpenStreetMap roads as prior knowledge to segment the remotely sensed imagery. Experiments were conducted on two ZiYuan-3 images and one QuickBird high-resolution grayscale image to compare our proposed method to other commonly used techniques for road feature extraction. The results demonstrated the validity and better performance of the proposed method for urban main road feature extraction. PMID:26397832
Optimizing morphology through blood cell image analysis.
Merino, A; Puigví, L; Boldú, L; Alférez, S; Rodellar, J
2018-05-01
Morphological review of the peripheral blood smear is still a crucial diagnostic aid as it provides relevant information related to the diagnosis and is important for selection of additional techniques. Nevertheless, the distinctive cytological characteristics of the blood cells are subjective and influenced by the reviewer's interpretation and, because of that, translating subjective morphological examination into objective parameters is a challenge. The use of digital microscopy systems has been extended in the clinical laboratories. As automatic analyzers have some limitations for abnormal or neoplastic cell detection, it is interesting to identify quantitative features through digital image analysis for morphological characteristics of different cells. Three main classes of features are used as follows: geometric, color, and texture. Geometric parameters (nucleus/cytoplasmic ratio, cellular area, nucleus perimeter, cytoplasmic profile, RBC proximity, and others) are familiar to pathologists, as they are related to the visual cell patterns. Different color spaces can be used to investigate the rich amount of information that color may offer to describe abnormal lymphoid or blast cells. Texture is related to spatial patterns of color or intensities, which can be visually detected and quantitatively represented using statistical tools. This study reviews current and new quantitative features, which can contribute to optimize morphology through blood cell digital image processing techniques. © 2018 John Wiley & Sons Ltd.
Morphological comparison of archaic Homo sapiens crania from China and Africa.
Wu, X; Bräuer, G
1993-12-01
Regional features play a great role in the analysis of the differentiations of Homo erectus and Homo sapiens. However, this poses the question how widespread and variable these features are. In order to examine this with regard to the features commonly seen in China their occurrence and variability were determined in Chinese as well as in African crania of archaic and late Pleistocene/Holocene modern Homo sapiens. Furthermore, some features known from Africa were examined with regard to their occurrence and variability in China. Although the variability might change due to new finds, the present results for some features point to larger morphological spectra in the African than in the Chinese archaic Homo sapiens. It is furthermore remarkable that the early modern Chinese in many features show deviations from the pattern of archaic Homo sapiens of this region and exhibit broader spectra similar to those seen in African archaic and early modern Homo sapiens.
Curious Case of a Stripped Elliptical Galaxy
NASA Astrophysics Data System (ADS)
Kohler, Susanna
2017-05-01
MUSE fields of view (1 1 for each square) are superimposed on a pseudo-color image of the elliptical galaxy in Abell 2670. The blue blobs lie in the opposite direction to the galactic center. [Sheen et al. 2017]An elliptical galaxy in the cluster Abell 2670 has been discovered with some unexpected features. What conditions led to this galaxys unusual morphology?Unexpected JellyfishWe often see galaxies that have been disrupted or reshaped due to their motion within a cluster but these are usually late-type galaxies like our own. Such gas-rich galaxies are distorted by ram pressure as they fall into the cluster center, growing long tails of stripped gas and young stars that earn them the name jellyfish galaxies.But early-type, elliptical galaxies have long since used up or cleared out most of their gas, and they correspondingly form very few new stars. Its therefore unsurprising that theyve never before been spotted to have jellyfish-like features.Panels a and b show zoomed-in observations of some of the star-forming blobs with tadpole-like morphology. Panel c shows a schematic illustration of how ram-pressure stripping causes this shape. [Adapted from Sheen et al. 2017]New deep observations of an elliptical galaxy in the cluster Abell 2670, however, have revealed some unexpected structures for an early-type galaxy. Led by Yun-Kyeong Sheen (Korea Astronomy and Space Science Institute), a team of scientists now reports on the optical and spectroscopic observations of this galaxy, made with the MUSE instrument on the Very Large Telescope in Chile.Tadpole BlobsThese observations reveal a number of features, including starbursts at the galactic center, 80-parsec-long tails of ionized gas, disturbed halo features, and several blue star-forming blobs with tadpole-like morphology in the surrounding region. The blobs have stellar tails that point in the direction of motion of the galaxy (toward the cluster center) and streams of ionized gas that point in the opposite direction.All of these features are signs that this galaxy is being ram-pressurestripped as it falls into the center of the cluster. The star-forming blobs, for example, are exhibiting classic ram-pressure-stripping behavior: as a galaxy falls into the cluster center, streams of ionized gas blow downwind, and stars (which dont respond as easily to the force of the wind) are left behind in a stream pointing upwind.Gas from a Merger?An example of a tidal tail drawn out from a disrupted late-type galaxy. The disrupted galaxy in Abell 2670 is, in contrast, an early-type, elliptical galaxy that should be gas-poor. [H. Ford, JHU/M. Clampin, STScI/G. Hartig, STScI/G. Illingworth, UCO, Lick/ACS Science Team/ESA/NASA]But if this is an elliptical galaxy, where did the gas come from for the tails and the galactic-center star formation? To rule out the obvious, the authors first check that this galaxy really is an early-type elliptical. The galaxys color (reddened), morphology (elliptical and no sign of a stellar disk), and stellar velocities (no sign of stellar rotation) all confirm this.The authors therefore speculate that the galaxy recently underwent a wet merger a merger with a companion galaxy that was gas-rich. Much of this gas was driven to the center of the elliptical galaxy in the merger, and its now responsible for the starbursts there.Well hopefully be able to draw stronger conclusions about this unusual galaxy after additional investigation into the amount of gas it contains and the galaxys star formation rate. In the meantime, this stripped elliptical makes for an intriguing puzzle!CitationYun-Kyeong Sheen et al 2017 ApJL 840 L7. doi:10.3847/2041-8213/aa6d79
The NGC 4013 tale: a pseudo-bulged, late-type spiral shaped by a major merger
NASA Astrophysics Data System (ADS)
Wang, Jianling; Hammer, Francois; Puech, Mathieu; Yang, Yanbin; Flores, Hector
2015-10-01
Many spiral galaxy haloes show stellar streams with various morphologies when observed with deep images. The origin of these tidal features is discussed, either coming from a satellite infall or caused by residuals of an ancient, gas-rich major merger. By modelling the formation of the peculiar features observed in the NGC 4013 halo, we investigate their origin. By using GADGET-2 with implemented gas cooling, star formation, and feedback, we have modelled the overall NGC 4013 galaxy and its associated halo features. A gas-rich major merger occurring 2.7-4.6 Gyr ago succeeds in reproducing the NGC 4013 galaxy properties, including all the faint stellar features, strong gas warp, boxy-shaped halo and vertical 3.6 μm luminosity distribution. High gas fractions in the progenitors are sufficient to reproduce the observed thin and thick discs, with a small bulge fraction, as observed. A major merger is able to reproduce the overall NGC 4013 system, including the warp strength, the red colour and the high stellar mass density of the loop, while a minor merger model cannot. Because the gas-rich model suffices to create a pseudo-bulge with a small fraction of the light, NGC 4013 is perhaps the archetype of a late-type galaxy formed by a relatively recent merger. Then late type, pseudo-bulge spirals are not mandatorily made through secular evolution, and the NGC 4013 properties also illustrate that strong warps in isolated galaxies may well occur at a late phase of a gas-rich major merger.
Cai, Hongmin; Peng, Yanxia; Ou, Caiwen; Chen, Minsheng; Li, Li
2014-01-01
Dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) is increasingly used for breast cancer diagnosis as supplementary to conventional imaging techniques. Combining of diffusion-weighted imaging (DWI) of morphology and kinetic features from DCE-MRI to improve the discrimination power of malignant from benign breast masses is rarely reported. The study comprised of 234 female patients with 85 benign and 149 malignant lesions. Four distinct groups of features, coupling with pathological tests, were estimated to comprehensively characterize the pictorial properties of each lesion, which was obtained by a semi-automated segmentation method. Classical machine learning scheme including feature subset selection and various classification schemes were employed to build prognostic model, which served as a foundation for evaluating the combined effects of the multi-sided features for predicting of the types of lesions. Various measurements including cross validation and receiver operating characteristics were used to quantify the diagnostic performances of each feature as well as their combination. Seven features were all found to be statistically different between the malignant and the benign groups and their combination has achieved the highest classification accuracy. The seven features include one pathological variable of age, one morphological variable of slope, three texture features of entropy, inverse difference and information correlation, one kinetic feature of SER and one DWI feature of apparent diffusion coefficient (ADC). Together with the selected diagnostic features, various classical classification schemes were used to test their discrimination power through cross validation scheme. The averaged measurements of sensitivity, specificity, AUC and accuracy are 0.85, 0.89, 90.9% and 0.93, respectively. Multi-sided variables which characterize the morphological, kinetic, pathological properties and DWI measurement of ADC can dramatically improve the discriminatory power of breast lesions.
NASA Astrophysics Data System (ADS)
Sánchez-Lavega, A.; Peralta, J.; Gomez-Forrellad, J. M.; Hueso, R.; Pérez-Hoyos, S.; Mendikoa, I.; Rojas, J. F.; Horinouchi, T.; Lee, Y. J.; Watanabe, S.
2016-12-01
We report Venus image observations around the two maximum elongations of the planet at 2015 June and October. From these images we describe the global atmospheric dynamics and cloud morphology in the planet before the arrival of JAXA’s Akatsuki mission on 2015 December 7. The majority of the images were acquired at ultraviolet wavelengths (380-410 nm) using small telescopes. The Venus dayside was also observed with narrowband filters at other wavelengths (890 nm, 725-950 nm, 1.435 μm CO2 band) using the instrument PlanetCam-UPV/EHU at the 2.2 m telescope in Calar Alto Observatory. In all cases, the lucky imaging methodology was used to improve the spatial resolution of the images over the atmospheric seeing. During the April-June period, the morphology of the upper cloud showed an irregular and chaotic texture with a well-developed equatorial dark belt (afternoon hemisphere), whereas during October-December the dynamical regime was dominated by planetary-scale waves (Y-horizontal, C-reversed, and ψ-horizontal features) formed by long streaks, and banding suggesting more stable conditions. Measurements of the zonal wind velocity with cloud tracking in the latitude range from 50°N to 50°S shows agreement with retrievals from previous works. Partially based on observations obtained at Centro Astronómico Hispano Alemán, Observatorio de Calar Alto MPIA-CSIC, Almería, Spain.
NASA Astrophysics Data System (ADS)
Coccini, T.; Roda, E.; Barni, S.; Manzo, L.
2013-04-01
Renal morphological parameters were determined in rats intratracheally instilled with model cadmium-containing silica nanoparticles (Cd-SiNPs, 1mg/rat), also exploring whether their potential modifications would be associated with toxicogenomic changes. Cd-SiNP effects, evaluated 7 and 30 days post-exposure, were assessed by (i) histopathology (Haematoxylin/Eosin Staining), (ii) characterization of apoptotic features by TUNEL staining. Data were compared with those obtained by CdCl2 (400μg/rat), SiNPs (600μg/rat), 0.1 ml saline. Area-specific cell apoptosis was observed in all treatment groups: cortex and inner medulla were the most affected regions. Apoptotic changes were apparent at 7 days post-exposure in both areas, and were still observable in inner medulla 30 days after treatment. Increase in apoptotic frequency was more pronounced in Cd-SiNP-treated animals compared to either CdCl2 or SiNPs. Histological findings showed comparable alterations in the renal glomerular (cortex) architecture occurring in all treatment groups at both time-points considered. The glomeruli appeared often collapsed, showing condensed, packed mesangial and endothelial cells. Oedematous haemorrhagic glomeruli were also observed in Cd-SiNPs-treated animals. Bare SiNPs caused morphological and apoptotic changes without modifying the renal gene expression profile. These findings support the concept that multiple assays and an integrated testing strategy should be recommended to characterize toxicological responses to nanoparticles in mammalian systems.
Controlling Film Morphology in Conjugated Polymer
Park, Lee Y.; Munro, Andrea M.; Ginger, David S.
2009-01-01
We study the effects of patterned surface chemistry on the microscale and nanoscale morphology of solution-processed donor/acceptor polymer-blend films. Focusing on combinations of interest in polymer solar cells, we demonstrate that patterned surface chemistry can be used to tailor the film morphology of blends of semiconducting polymers such as poly-[2-(3,7-dimethyloctyloxy)-5-methoxy-p-phenylenevinylene] (MDMO-PPV), poly-3-hexylthiophene (P3HT), poly[(9,9-dioctylflorenyl-2,7-diyl)-co-benzothiadiazole)] (F8BT), and poly(9,9-dioctylfluorene-co-bis-N,N’-(4-butylphenyl)-bis-N,N’-phenyl-1,4-phenylendiamine) (PFB) with the fullerene derivative, [6,6]-phenyl-C61-butyric acid methyl ester (PCBM). We present a method for generating patterned, fullerene-terminated monolayers on gold surfaces, and use microcontact printing and Dip-Pen Nanolithography (DPN) to pattern alkanethiols with both micro- and nanoscale features. After patterning with fullerenes and other functional groups, we backfill the rest of the surface with a variety of thiols to prepare substrates with periodic variations in surface chemistry. Spin coating polymer:PCBM films onto these substrates, followed by thermal annealing under nitrogen, leads to the formation of structured polymer films. We characterize these films with Atomic Force Microscopy (AFM), Raman spectroscopy, and fluorescence microscopy. The surface patterns are effective in guiding phase separation in all of the polymer:PCBM systems investigated, and lead to a rich variety of film morphologies that are inaccessible with unpatterned substrates. We demonstrate our ability to guide pattern formation in films thick enough of be of interest for actual device applications (up to 200 nm in thickness) using feature sizes as small as 100 nm. Finally, we show that the surface chemistry can lead to variations in film morphology on length scales significantly smaller than those used in generating the original surface patterns. The variety of behaviors observed and the wide range of control over polymer morphology achieved at a variety of different length scales have important implications for the development of bulk heterojunction solar cells. PMID:18983150
NASA Astrophysics Data System (ADS)
Buta, Ronald J.
2017-10-01
Dark gaps are commonly seen in early-to-intermediate-type barred galaxies having inner and outer rings or related features. In this paper, the morphologies of 54 barred and oval ringed galaxies have been examined with the goal of determining what the dark gaps are telling us about the structure and evolution of barred galaxies. The analysis is based mainly on galaxies selected from the Galaxy Zoo 2 data base and the Catalogue of Southern Ringed Galaxies. The dark gaps between inner and outer rings are of interest because of their likely association with the L4 and L5 Lagrangian points that would be present in the gravitational potential of a bar or oval. Since the points are theoretically expected to lie very close to the corotation resonance (CR) of the bar pattern, the gaps provide the possibility of locating corotation in some galaxies simply by measuring the radius rgp of the gap region and setting rCR=rgp. With the additional assumption of generally flat rotation curves, the locations of other resonances can be predicted and compared with observed morphological features. It is shown that this `gap method' provides remarkably consistent interpretations of the morphology of early-to-intermediate-type barred galaxies. The paper also brings attention to cases where the dark gaps lie inside an inner ring, rather than between inner and outer rings. These may have a different origin compared to the inner/outer ring gaps.
Effects of a groyne field on inner bar dynamics: Anglet, France
NASA Astrophysics Data System (ADS)
de Santiago, Inaki; Morichon, Denis; Arnould, Philippe
2017-04-01
Groynes are usually designed to limit beach erosion by mitigating longshore sediment transport. However, little is known about their side effects on inner-bar morphodynamics in double sandbar systems. While most of the studies are focused on natural systems where the outer-bar morphology drives inner-bar dynamics (offshore to nearshore process), this work focuses on the role of groynes on the inner bar dynamics (nearshore to offshore process). The study is based on 3-years field observations carried out at the beach of Anglet in the south-west of France. This engineered beach is 4 km long, limited by a rocky headland in the south and a 1 km long jetty at the entrance of the Adour river in the North. The study area concerns the south part of the beach and includes a series of four groynes, unevenly spaced and extending about 100 m seaward. Morphology changes observations were derived from images collected with a video system (http://sirena.univ-pau.fr/), and bi-annual topo-Bathymetric surveys. A special attention was paid to study the mechanisms controlling the observed morphology changes using the XBeach numerical model. Data analysis reveals that the study site is dominated by a double sandbar system. Both bars can evolve from reasonably alongshore-uniform to crescentic bars. Surprisingly, the beach may show episodes where the inner bar evolves from alonghsore uniform to non-uniform despite an alongshore uniform outer bar. Numerical results corroborate that the formation of inner bar crescentic features can be formed without the presence of an outer non-uniform bar under certain wave conditions for the study site. This study shows that inner bar evolution in the presence of groynes can be controlled by topographic rip channels and not only by morphological coupling as usually observed on natural double sandbar systems.
Texture analysis applied to second harmonic generation image data for ovarian cancer classification
NASA Astrophysics Data System (ADS)
Wen, Bruce L.; Brewer, Molly A.; Nadiarnykh, Oleg; Hocker, James; Singh, Vikas; Mackie, Thomas R.; Campagnola, Paul J.
2014-09-01
Remodeling of the extracellular matrix has been implicated in ovarian cancer. To quantitate the remodeling, we implement a form of texture analysis to delineate the collagen fibrillar morphology observed in second harmonic generation microscopy images of human normal and high grade malignant ovarian tissues. In the learning stage, a dictionary of "textons"-frequently occurring texture features that are identified by measuring the image response to a filter bank of various shapes, sizes, and orientations-is created. By calculating a representative model based on the texton distribution for each tissue type using a training set of respective second harmonic generation images, we then perform classification between images of normal and high grade malignant ovarian tissues. By optimizing the number of textons and nearest neighbors, we achieved classification accuracy up to 97% based on the area under receiver operating characteristic curves (true positives versus false positives). The local analysis algorithm is a more general method to probe rapidly changing fibrillar morphologies than global analyses such as FFT. It is also more versatile than other texture approaches as the filter bank can be highly tailored to specific applications (e.g., different disease states) by creating customized libraries based on common image features.
Franzese, Sebastián; Ivanov, Verónica A
2018-08-01
Two hyperapolytic species of Acanthobothrium Blanchard, 1848 have been collected from Discopyge tschudii Heckel, 1846 and Zapteryx brevirostris (Müller et Henle) along the coast of Argentina. Acanthobothrium stefaniae sp. n. from D. tschudii is a category one species (i.e., it is less than 15 mm in total length, possesses fewer than 50 proglottids, fewer than 80 testes and essentially symmetrical ovary), and differs from all congeners by the following combination of features: proglottid hyperapolysis, hook morphology, size and shape of the cirrus sac, and by having spinitriches in the distal bothridial surface. This is the first record of Acanthobothrium in Discopyge Heckel, 1846. The specimens from Z. brevirostris conform to the morphology of Acanthobothrium zapterycum Ostrowski de Núñez, 1971. A redescription of this species is presented, which expands most ranges of measurements originally given, and provides details omitted in the original description, including the microthrix pattern. This study allowed us to observe the intraspecific variation in ovarian symmetry in A. zapterycum, which shed some doubt on the validity of this as a diagnostic feature. The reproductive strategy (apolysis) of several species of Acanthobothrium was reviewed and summarized. Copyright © 2018. Published by Elsevier B.V.
Computation of breast ptosis from 3D surface scans of the female torso
Li, Danni; Cheong, Audrey; Reece, Gregory P.; Crosby, Melissa A.; Fingeret, Michelle C.; Merchant, Fatima A.
2016-01-01
Stereophotography is now finding a niche in clinical breast surgery, and several methods for quantitatively measuring breast morphology from 3D surface images have been developed. Breast ptosis (sagging of the breast), which refers to the extent by which the nipple is lower than the inframammary fold (the contour along which the inferior part of the breast attaches to the chest wall), is an important morphological parameter that is frequently used for assessing the outcome of breast surgery. This study presents a novel algorithm that utilizes three-dimensional (3D) features such as surface curvature and orientation for the assessment of breast ptosis from 3D scans of the female torso. The performance of the computational approach proposed was compared against the consensus of manual ptosis ratings by nine plastic surgeons, and that of current 2D photogrammetric methods. Compared to the 2D methods, the average accuracy for 3D features was ~13% higher, with an increase in precision, recall, and F-score of 37%, 29%, and 33%, respectively. The computational approach proposed provides an improved and unbiased objective method for rating ptosis when compared to qualitative visualization by observers, and distance based 2D photogrammetry approaches. PMID:27643463
Scenic drive landslide of January-March 1998, La Honda, San Mateo County, California
Jayko, Angela S.; Rymer, Michael J.; Prentice, Carol S.; Wilson, Ray C.; Wells, Ray E.
1998-01-01
The small rural town of La Honda, Calif., is an unincorporated region of San Mateo County situated in the Santa Cruz Mountains in the western part of the San Francisco peninsula. Much of the town is underlain by a previously recognized ancient landslide complex. The ancient slide complex covers about 1.0 to 1.25 km2, parts of which have been historically active. This report describes a recent landslide involving part of Scenic Drive, La Honda, that became active in January 1998. This report does not describe other currently active landslides in La Honda, such as the January 1998 slide on lower Recreation Drive, or the history of sliding in the area. This report concerns the principal morphological features we observed and mapped between 11 February and 21 March 1998 on an enlargement of a 1:7500-scale air photo acquired 6 March 1998 and prior to that on a town property-line map, and by laser survey carried out between 26 February and 8 March. The principal objective of this report is to make available the detailed photographic and topographic base maps and associated description of surface morphological features.
Impression of plasma voltage on growth of α-V{sub 2}O{sub 5} nanostructured thin films
DOE Office of Scientific and Technical Information (OSTI.GOV)
Sharma, Rabindar Kumar, E-mail: rkrksharma6@gmail.com; Kumar, Prabhat; Reddy, G. B.
2015-06-24
In this communication, we synthesized vanadium pentoxide (α-V{sub 2}O{sub 5}) nanostructured thin films (NST{sub s}) accompanied with nanoflakes/ nanoplates on the Ni-coated glass substrates employing plasma assisted sublimation process (PASP) as a function of plasma voltage (V{sub p}). The effect of plasma voltage on structural, morphological, compositional, and vibrational properties have been studied systematically. The structural analysis divulged that all films deposited at different V{sub p} have pure orthorhombic phase, no impurity phase is detected under resolution limit of XRD and XPS. The morphological studies of samples is carried out by SEM, revealed that features as well as alignment ofmore » V{sub 2}O{sub 5} NST{sub s} is greatly monitored by V{sub p} and the film possessing the best features is obtained at 2500volt. In addition, XPS results reveal that V{sup 5+} oxidation state is the most prominent state in sample V{sub 2}, which represents better stoichiometric nature of film. The vibrational study of all samples is performed by FTIR and strongly support the XRD observations. All the results are in consonance with each other.« less
Quantification of Soil Pore Structure Based on Minkowski-Functions
NASA Astrophysics Data System (ADS)
Vogel, H.; Weller, U.; Schlüter, S.
2009-05-01
The porous structure in soils and other geologic media is typically a complex 3-dimensional object. Most of the physical material properties including mechanical and hydraulic characteristics are immediately linked to this structure which can be directly observed using non-invasive techniques as e.g. X-ray tomography. It is an old dream and still a formidable challenge to related structural features of porous media to their physical properties. In this contribution we present a scale-invariant concept to quantify pore structure based on a limited set of meaningful morphological functions. They are based on d+1 Minkowski functionals as defined for d-dimensional bodies. These basic quantities are determined as a function of pore size obtained by filter procedures using mathematical morphology. The resulting Minkowski functions provide valuable information on pore size, pore surface area and pore topology having the potential to be linked to physical properties. The theoretical background and the related algorithms are presented and the approach is demonstrated for the structure of an arable topsoil obtained by X-ray micro tomography. We also discuss the fundamental problem of limited resolution which is critical for any attempt to quantify structural features at any scale.
USDA-ARS?s Scientific Manuscript database
This paper evaluates the potential usefulness of low temperature-scanning electron microscopy (LT-SEM) to evaluate morphology and predation behavior of the six-spotted thrips (Scolothrips sexmaculatus Pergande) against the two-spotted spider mite (Tetranychus urticae (Koch)). Morphological features...
ALFALFA and WSRT Imaging of Extended H I Features in the Leo Cloud of Galaxies
NASA Astrophysics Data System (ADS)
Leisman, Lukas; Haynes, Martha P.; Giovanelli, Riccardo; Józsa, Gyula; Adams, Elizabeth A. K.; Hess, Kelley M.
2016-12-01
We present Arecibo Legacy Fast ALFA (ALFALFA) H I observations of a well-studied region of the Leo Cloud, which includes the NGC 3227 group and the NGC 3190 group. We detect optically dark H I tails and plumes with extents potentially exceeding 600 kpc, well beyond the field of view of previous observations. These H I features contain ˜40 per cent of the total H I mass in the NGC 3227 group and ˜10 per cent of the NGC 3190 group. We also present Westerbork Synthesis Radio Telescope (WSRT) maps which show the complex morphology of the extended emission in the NGC 3227 group. We comment on previously proposed models of the interactions in these groups and the implications for the scale of group processing through interactions. Motivated by the extent of the H I plumes, we place the H I observations in the context of the larger loose group, demonstrating the need for future sensitive, wide field H I surveys to understand the role of group processing in galaxy evolution.
An Interferometric Spectral Line and Imaging Survey of VY Canis Majoris in the 345 GHz Band
NASA Astrophysics Data System (ADS)
Kamiński, T.; Gottlieb, C. A.; Young, K. H.; Menten, K. M.; Patel, N. A.
2013-12-01
A spectral line survey of the oxygen-rich red supergiant VY Canis Majoris was made between 279 and 355 GHz with the Submillimeter Array (SMA). Two hundred twenty-three spectral features from 19 molecules (not counting isotopic species of some of them) were observed, including the rotational spectra of TiO, TiO2, and AlCl for the first time in this source. The parameters and an atlas of all spectral features are presented. Observations of each line with a synthesized beam of ~0.''9, reveal the complex kinematics and morphology of the nebula surrounding VY CMa. Many of the molecules are observed in high-lying rotational levels or in excited vibrational levels. From these, it was established that the main source of the submillimeter-wave continuum (dust) and the high-excitation molecular gas (the star) are separated by about 0.''15. Apparent coincidences between the molecular gas observed with the SMA, and some of the arcs and knots observed at infrared wavelengths and in the optical scattered light by the Hubble Space Telescope are identified. The observations presented here provide important constraints on the molecular chemistry in oxygen-dominated circumstellar environments and a deeper picture of the complex circumstellar environment of VY CMa.
Farrar, R G; Klei, T R
1985-08-01
Strongylus edentatus was successfully cultured in vitro to the fourth larval stage (L4). Some growth continued for periods of 40-50 days at which time reductions in viability were observed in some of the culture systems tested. Various combinations of media, sera, buffers and organ explant cultures were tested. All cultures were incubated at 37 C in an atmosphere of 95% air and 5% CO2. Larvae underwent growth and differentiation to the L4 in all medium-serum combinations with and without organ explant cultures. Development and growth did occur but viability was reduced to insignificant levels in media without serum or cells. Optimal growth, differentiation, and longevity were observed in bicarbonate buffered RPMI-1640 containing 10% fetal calf serum and gerbil (Meriones unguiculatus) cecum explant cultures. Observations indicated that Strongylus vulgaris and Strongylus equinus also developed to the L4 stage using similar techniques. However, viability of S. vulgaris L4 was markedly limited. Specific morphological changes marked phases of development of S. edentatus, categorized as early, middle and late third stage, third molt and early fourth stage. Strongylus equinus appeared to follow the same developmental pattern in vitro as S. edentatus. Distinct differences in morphological features during differentiation were observed between S. edentatus and S. vulgaris.
Guisande, Cástor; Vari, Richard P; Heine, Jürgen; García-Roselló, Emilio; González-Dacosta, Jacinto; Perez-Schofield, Baltasar J García; González-Vilas, Luis; Pelayo-Villamil, Patricia
2016-09-12
We present and discuss VARSEDIG, an algorithm which identifies the morphometric features that significantly discriminate two taxa and validates the morphological distinctness between them via a Monte-Carlo test. VARSEDIG is freely available as a function of the RWizard application PlotsR (http://www.ipez.es/RWizard) and as R package on CRAN. The variables selected by VARSEDIG with the overlap method were very similar to those selected by logistic regression and discriminant analysis, but overcomes some shortcomings of these methods. VARSEDIG is, therefore, a good alternative by comparison to current classical classification methods for identifying morphometric features that significantly discriminate a taxon and for validating its morphological distinctness from other taxa. As a demonstration of the potential of VARSEDIG for this purpose, we analyze morphological discrimination among some species of the Neotropical freshwater family Characidae.
Breast tumor angiogenesis analysis using 3D power Doppler ultrasound
NASA Astrophysics Data System (ADS)
Chang, Ruey-Feng; Huang, Sheng-Fang; Lee, Yu-Hau; Chen, Dar-Ren; Moon, Woo Kyung
2006-03-01
Angiogenesis is the process that correlates to tumor growth, invasion, and metastasis. Breast cancer angiogenesis has been the most extensively studied and now serves as a paradigm for understanding the biology of angiogenesis and its effects on tumor outcome and patient prognosis. Most studies on characterization of angiogenesis focus on pixel/voxel counts more than morphological analysis. Nevertheless, in cancer, the blood flow is greatly affected by the morphological changes, such as the number of vessels, branching pattern, length, and diameter. This paper presents a computer-aided diagnostic (CAD) system that can quantify vascular morphology using 3-D power Doppler ultrasound (US) on breast tumors. We propose a scheme to extract the morphological information from angiography and to relate them to tumor diagnosis outcome. At first, a 3-D thinning algorithm helps narrow down the vessels into their skeletons. The measurements of vascular morphology significantly rely on the traversing of the vascular trees produced from skeletons. Our study of 3-D assessment of vascular morphological features regards vessel count, length, bifurcation, and diameter of vessels. Investigations into 221 solid breast tumors including 110 benign and 111 malignant cases, the p values using the Student's t-test for all features are less than 0.05 indicating that the proposed features are deemed statistically significant. Our scheme focuses on the vascular architecture without involving the technique of tumor segmentation. The results show that the proposed method is feasible, and have a good agreement with the diagnosis of the pathologists.
Jupiter's non-auroral Ionosphere and Thermosphere
NASA Astrophysics Data System (ADS)
Stallard, T.; Melin, H.; Burrell, A. G.; Hsu, V.; Johnson, R.; Moore, L.; O'Donoghue, J.; Thayer, J. P.
2017-12-01
Until recently, our understanding of the non-auroral ionosphere of Jupiter was very limited. However, with the arrival of the Juno spacecraft at Jupiter, we have begun to revise past observations of this region, as well as utilizing modern telescope facilities, in order to reveal a complex array of ionospheric features that show strong coupling with both the local magnetic field and dynamics within the underlying thermosphere. The first feature that was identified was an apparent `Great Dark Spot' in the sub-auroral ionosphere, almost as large as the Great Red Spot. This was observed well away from the northern magnetic pole, mapping to only 2.4 jovian radii. Spectra of the feature showed that it was produced by a 150K cooling in the thermosphere. However, images taken between 1995-2000 showed this feature was consistently observed over two decades at similar magnetic longitudes, but appeared to vary in size, morphology and exact location on a timescale of only days. This suggests that the Great Dark Spot is a large thermospheric vortex driven by auroral heating, similar to transitory features observed at Earth, forming in sub-auroral regions during periods of active aurora. Careful analysis of the Jupiter images then allowed us to measure ionospheric emission down to the equator. This revealed the location of Jupiter's magnetic equator for the first time, appearing as a dark sinusoidal ribbon. This feature appears to be produced as photo-electrons are pushed poleward of the equator when magnetic fields are parallel with the planet's surface, a different process than the dominant plasma fountain that drives Earth's equatorial anomaly. Also revealed were a series of dark spots. Recent Juno magnetometer measurements show that two of these spots appear in regions of high radial magnetic field, suggesting that these regions of the ionosphere are shielded, an inversion of the same process that drives higher ionization in the South Atlantic Anomaly.
A numerical model for explaining the role of the interface morphology in composite solar cells
NASA Astrophysics Data System (ADS)
Martin, C. M.; Burlakov, V. M.; Assender, H. E.; Barkhouse, D. A. R.
2007-11-01
We have developed a numerical model that simulates the operation of organic/inorganic photovoltaic devices. Using this model, we have investigated the effect of the interface morphology and have shown that for a given system, there is both a most efficient device thickness and the interfacial feature size for overall power conversion. The variation of current-voltage (I-V) curves with differing recombination rates, anode barrier height, and light intensity has been simulated with reducing the recombination rate and lowering the anode barrier height shown to lead to improved open circuit voltages and fill factors. Through this model, we show that the increase in fill factor observed when the lithium salt Li[CF3SO2]2N is added to devices can be explained by an increase in the polymer hole mobility.
Kudlai, Olena; Tkach, Vasyl V; Pulis, Eric E; Kostadinova, Aneta
2015-01-01
Euparyphium capitaneum Dietz, 1909, the type-species of the genus Euparyphium Dietz, 1909, is described on the basis of material collected from the type-host Anhinga anhinga (L.) from Pascagoula River, which drains into the northern coast of the Gulf of Mexico. Combination of light and scanning electron microscopy observations of freshly collected and properly fixed specimens in our study has allowed us to provide novel information on the morphology and topology of the reproductive systems and other morphological features of the species. A Bayesian inference analysis based on the newly-obtained partial sequence of the nuclear 28S rRNA gene for E. capitaneum and 24 previously published sequences from the superfamily Echinostomatoidea Looss, 1899 provided evidence supporting the distinct status of the genera Euparyphium and Isthmiophora Lühe, 1909.
Stem cell behavior on tailored porous oxide surface coatings.
Lavenus, Sandrine; Poxson, David J; Ogievetsky, Nika; Dordick, Jonathan S; Siegel, Richard W
2015-07-01
Nanoscale surface topographies are known to have a profound influence on cell behavior, including cell guidance, migration, morphology, proliferation, and differentiation. In this study, we have observed the behavior of human mesenchymal stem cells cultured on a range of tailored porous SiO2 and TiO2 nanostructured surface coatings fabricated via glancing angle electron-beam deposition. By controlling the physical vapor deposition angle during fabrication, we could control systematically the deposited coating porosity, along with associated topographic features. Immunocytochemistry and image analysis quantitatively revealed the number of adherent cells, as well as their basic cellular morphology, on these surfaces. Signaling pathway studies showed that even with subtle changes in nanoscale surface structures, the behavior of mesenchymal stem cells was strongly influenced by the precise surface structures of these porous coatings. Copyright © 2015 Elsevier Ltd. All rights reserved.
Active shoreline of Ontario Lacus, Titan: A morphological study of the lake and its surroundings
Wall, S.; Hayes, A.; Bristow, C.; Lorenz, R.; Stofan, E.; Lunine, J.; Le, Gall A.; Janssen, M.; Lopes, R.; Wye, L.; Soderblom, L.; Paillou, P.; Aharonson, O.; Zebker, H.; Farr, Tom; Mitri, Giuseppe; Kirk, R.; Mitchell, Ken; Notarnicola, C.; Casarano, D.; Ventura, B.
2010-01-01
Of more than 400 filled lakes now identified on Titan, the first and largest reported in the southern latitudes is Ontario Lacus, which is dark in both infrared and microwave. Here we describe recent observations including synthetic aperture radar (SAR) images by Cassini's radar instrument (??= 2 cm) and show morphological evidence for active material transport and erosion. Ontario Lacus lies in a shallow depression, with greater relief on the southwestern shore and a gently sloping, possibly wave-generated beach to the northeast. The lake has a closed internal drainage system fed by Earth-like rivers, deltas and alluvial fans. Evidence for active shoreline processes, including the wave-modified lakefront and deltaic deposition, indicates that Ontario is a dynamic feature undergoing typical terrestrial forms of littoral modification. Copyright ?? 2010 by the American Geophysical Union.
Cratering on Ceres: Implications for its crust and evolution
Hiesinger, H.; Marchi, S.; Schmedemann, N.; Schenk, P.; Pasckert, J. H.; Neesemann, A.; O'Brien, D. P.; Kneissl, T.; Ermakov, A.; Fu, R.R.; Bland, M. T.; Nathues, A.; Platz, T.; Williams, D.A.; Jaumann, R.; Castillo-Rogez, J. C.; Ruesch, O.; Schmidt, B.; Park, R.S.; Preusker, F.; Buczkowski, D.L.; Russell, C.T.; Raymond, C.A.
2016-01-01
Thermochemical models have predicted that Ceres, is to some extent, differentiated and should have an icy crust with few or no impact craters. We present observations by the Dawn spacecraft that reveal a heavily cratered surface, a heterogeneous crater distribution, and an apparent absence of large craters. The morphology of some impact craters is consistent with ice in the subsurface, which might have favored relaxation, yet large unrelaxed craters are also present. Numerous craters exhibit polygonal shapes, terraces, flowlike features, slumping, smooth deposits, and bright spots. Crater morphology and simple-to-complex crater transition diameters indicate that the crust of Ceres is neither purely icy nor rocky. By dating a smooth region associated with the Kerwan crater, we determined absolute model ages (AMAs) of 550 million and 720 million years, depending on the applied chronology model.
Race- and Sex-Related Differences in Retinal Thickness and Foveal Pit Morphology
Wagner-Schuman, Melissa; Dubis, Adam M.; Nordgren, Rick N.; Lei, Yuming; Odell, Daniel; Chiao, Hellen; Weh, Eric; Fischer, William; Sulai, Yusufu; Dubra, Alfredo
2011-01-01
Purpose. To examine sex- and race-associated differences in macular thickness and foveal pit morphology by using spectral-domain optical coherence tomography (SD-OCT). Methods. One hundred eighty eyes of 90 healthy patients (43 women, 47 men) underwent retinal imaging with spectral-domain OCT. The lateral scale of each macular volume scan was corrected for individual differences in axial length by ocular biometry. From these corrected volumes, Early Treatment Diabetic Retinopathy Study (ETDRS) grids of retinal thickness were generated and compared between the groups. Foveal morphology was measured with previously described algorithms. Results. Compared with the Caucasians, the Africans and African Americans had reduced central subfield thickness. Central subfield thickness was also reduced in the women compared with the men, although the women also showed significant thinning in parafoveal regions. There was no difference between the sexes in foveal pit morphology; however, the Africans/African Americans had significantly deeper and broader foveal pits than the Caucasians. Conclusions. Previous studies have reported race- and sex-associated differences in macular thickness, and the inference has been that these differences represent similar anatomic features. However, the data on pit morphology collected in the present study reveal an important and significant variation. Between the sexes, the differences are due to global variability in retinal thickness, whereas the variation in thickness observed between the races appears to be driven by differences in foveal pit morphology. These differences have important implications for the use of SD-OCT in detecting and diagnosing retinal disease. PMID:20861480
NASA Astrophysics Data System (ADS)
Li, S.; Zhang, S.; Yang, D.
2017-09-01
Remote sensing images are particularly well suited for analysis of land cover change. In this paper, we present a new framework for detection of changing land cover using satellite imagery. Morphological features and a multi-index are used to extract typical objects from the imagery, including vegetation, water, bare land, buildings, and roads. Our method, based on connected domains, is different from traditional methods; it uses image segmentation to extract morphological features, while the enhanced vegetation index (EVI), the differential water index (NDWI) are used to extract vegetation and water, and a fragmentation index is used to the correct extraction results of water. HSV transformation and threshold segmentation extract and remove the effects of shadows on extraction results. Change detection is performed on these results. One of the advantages of the proposed framework is that semantic information is extracted automatically using low-level morphological features and indexes. Another advantage is that the proposed method detects specific types of change without any training samples. A test on ZY-3 images demonstrates that our framework has a promising capability to detect change.
NASA Astrophysics Data System (ADS)
Schäppi, B.; Molnar, P.; Perona, P.; Tockner, K.; Burlando, P.
2009-04-01
Healthy floodplain ecosystems are characterized by high habitat diversity which tends to be lost in straightened channelized rivers. River restoration projects aim to increase habitat heterogeneity by re-establishing natural flow conditions and/or re-activating geomorphic processes in straightened reaches. The success of such projects is usually measured by means of structural and functional hydrogeomorphic and ecological indicators. Important indicators include flow variables and morphological features such as flow depth, velocity, shore line length, exposed gravel area and wetted river width. Also important are the rates at which these variables and features change under varying streamflow. A high spatial variability in the indicators is generally connected with high habitat diversity. The temporal availability and spatial distribution of both aquatic and riparian habitats control the composition and diversity of benthic organisms, fish, and riparian communities. Spatial heterogeneity provides refugia, i.e. areas from which recolonization after a disturbance event may occur. In addition, it facilitates the transfer of organisms and matter across the aquatic and terrestrial interface, thereby increasing the overall functional performance of coupled river-riparian ecosystems. However the habitat diversity can be maintained over time only if there are frequent disturbances such as periodic floods that reset the system and create new germination sites for pioneer vegetation and rework the channel bed to form new aquatic habitat. Therefore the flow and morphology indicators need to be investigated on spatial as well as on temporal scales. Traditionally, these indicators are measured in the field albeit most measurements can be carried out only at low flow conditions. We propose that flow simulations with a 2d hydrodynamic model may be used for a fast and convenient assessment of indicators of flow variables and morphological features with relatively little calibration required and we illustrate an example thereof. The advantage of using computer simulations as compared to field observations is that a range of discharges can be investigated. Using a flood frequency analysis the return period of simulated flows can be estimated and translated into frequency-dependent habitat types. In order to investigate how flow variables change, we conducted a series of 2d flow simulations at different flow rates along the prealpine Thur River (Switzerland) consisting of both restored and straight reaches. Restoration basically consisted of widening the river cross-section and allowing a natural morphology to form. The simulated flow variables (flow depth and velocity) were then analyzed separately for the two reaches. The distributions of the both variables for the restored reach were significantly different from the straight reach, most notably an increase in the variance was observed. In order to analyze the temporal variability we investigated the development of the riverbed morphology over time using different digital elevation models combined with cross section data measured at annual intervals. Spatially explicit erosion and deposition patterns were derived from this analysis. The riverbed topography at different dates was then used to analyze the temporal evolution of the flow indicators for the different flow conditions. Comparisons between the restored and straight reaches allow us to assess the success of river restoration in terms of flow variability and morphological complexity.
Araki, Tetsuro; Sholl, Lynette M.; Gerbaudo, Victor H.; Hatabu, Hiroto; Nishino, Mizuki
2014-01-01
OBJECTIVE The purpose of this article is to investigate the imaging characteristics of pathologically proven thymic hyperplasia and to identify features that can differentiate true hyperplasia from lymphoid hyperplasia. MATERIALS AND METHODS Thirty-one patients (nine men and 22 women; age range, 20–68 years) with pathologically confirmed thymic hyperplasia (18 true and 13 lymphoid) who underwent preoperative CT (n = 27), PET/CT (n = 5), or MRI (n = 6) were studied. The length and thickness of each thymic lobe and the transverse and anterior-posterior diameters and attenuation of the thymus were measured on CT. Thymic morphologic features and heterogeneity on CT and chemical shift on MRI were evaluated. Maximum standardized uptake values were measured on PET. Imaging features between true and lymphoid hyperplasia were compared. RESULTS No significant differences were observed between true and lymphoid hyperplasia in terms of thymic length, thickness, diameters, morphologic features, and other qualitative features (p > 0.16). The length, thickness, and diameters of thymic hyperplasia were significantly larger than the mean values of normal glands in the corresponding age group (p < 0.001). CT attenuation of lymphoid hyperplasia was significantly higher than that of true hyperplasia among 15 patients with contrast-enhanced CT (median, 47.9 vs 31.4 HU; Wilcoxon p = 0.03). The receiver operating characteristic analysis yielded greater than 41.2 HU as the optimal threshold for differentiating lymphoid hyperplasia from true hyperplasia, with 83% sensitivity and 89% specificity. A decrease of signal intensity on opposed-phase images was present in all four cases with in- and opposed-phase imaging. The mean maximum standardized uptake value was 2.66. CONCLUSION CT attenuation of the thymus was significantly higher in lymphoid hyperplasia than in true hyperplasia, with an optimal threshold of greater than 41.2 HU in this cohort of patients with pathologically confirmed thymic hyperplasia. PMID:24555583
Chiang, Sarah; Snuderl, Matija; Kojiro-Sanada, Sakiko; Quer Pi-Sunyer, Ariadna; Daya, Dean; Hayashi, Tohru; Bosincu, Luisanna; Ogawa, Fumihiro; Rosenberg, Andrew E; Horn, Lars-Christian; Wang, Lu; Iafrate, A John; Oliva, Esther
2017-06-01
Primary primitive neuroectodermal tumor (PNET) of the female genital tract is rare, and its proper classification remains unclear. The clinical, histologic, and immunophenotypic features as well as EWSR1 rearrangement status of 19 gynecologic PNETs, including 10 ovarian, 8 uterine, and 1 vulvar tumors, are herein reported. Patient age ranged from 12 to 68 years, with a median age of 20 and 51 years among those with ovarian and uterine PNETs, respectively. Morphologic features of central nervous system (CNS) tumors were seen in 15 PNETs, including 9 medulloblastomas, 3 ependymomas, 2 medulloepitheliomas, and 1 glioblastoma, consistent with central PNET. The remaining 4 PNETs were composed entirely of undifferentiated small round blue cells and were classified as Ewing sarcoma/peripheral PNET. Eight PNETs were associated with another tumor type, including 5 ovarian mature cystic teratomas, 2 endometrial low-grade endometrioid carcinomas, and a uterine carcinosarcoma. By immunohistochemistry, 17 PNETs expressed at least 1 marker of neuronal differentiation, including synaptophysin, NSE, CD56, S100, and chromogranin in 10, 8, 14, 8, and 1 tumors, respectively. GFAP was positive in 4 PNETs, all of which were of central type. Membranous CD99 and nuclear Fli-1 staining was seen in 10 and 16 tumors, respectively, and concurrent expression of both markers was seen in both central and Ewing sarcoma/peripheral PNETs. All tumors expressed vimentin, whereas keratin cocktail (CAM5.2, AE1/AE3) staining was only focally present in 4 PNETs. Fluorescence in situ hybridization was successful in all cases and confirmed EWSR1 rearrangement in 2 of 4 tumors demonstrating morphologic features of Ewing sarcoma/peripheral PNET and concurrent CD99 and Fli-1 expression. In conclusion, central and Ewing sarcoma/peripheral PNETs may be encountered in the female genital tract with central PNETs being more common. Central PNETs show a spectrum of morphologic features that overlaps with CNS tumors but lack EWSR1 rearrangements. GFAP expression supports a morphologic impression of central PNET and is absent in Ewing sarcoma/peripheral PNET. Ewing sarcoma/peripheral PNETs lack morphologic features of CNS tumors.
NASA Astrophysics Data System (ADS)
Sandersen, Peter B. E.; Jørgensen, Flemming; Møller, Rasmus R.
2013-04-01
The topography in southern Denmark is dominated by Late Glacial outwash plains surrounding remnants of older Saalian hills. The outwash plains were formed outside the Last Glacial Maximum (LGM) with a gently sloping surface averaging 1 m per 1.000 m. Formed in a proglacial environment the outwash plains have largely remained undisturbed by glacier ice and we would thus expect any topographic irregularities to relate to postglacial events. In that sense, the outwash plains constitute an ideal landform for identifying tectonic events during the late and postglacial periods. Irregularities in the present day glacial topography, such as kettle holes and other types of depressions are commonly linked to decay of dead ice. But this perception needs in many instances a further examination especially because of the recent availability of highly detailed LiDAR data. The investigation area is situated above the Tønder Graben structure at the northern margin of the North German Basin. The Tønder Graben was formed along the WNW-ESE trending Rømø Fault Zone and mobilization of Zechstein salt added to the evolution of the graben. The Tønder Graben has caused a significant impact on the Mesozoic and Cenozoic sedimentary successions and is for instance clearly expressed as large elongate depressions in the Top Chalk surface. On the larger scale, no clear signs of the outline of the graben structure can be seen in the present day topography to indicate movements during the Quaternary. However, when high resolution LiDAR data is investigated carefully signatures of neotectonic movements emerges on the outwash plain. Among these are morphological features such as: 1) Significant level changes along distinct lineaments, 2) frequent slope changes of neighboring areas, 3) 180 degree changes in dip direction and 4) presence of close lying polygonal areas with marked shifts in terrain level. All these morphological features are found right on top of the Tønder Graben. In addition to these smaller scale morphological features we also identify a large area of the outwash plain without the expected slope forming a large and unusual threshold in the surface. Combined with information from boreholes and seismic data we relate the morphological irregularities to movements of the underlying Tønder Graben structure. Because we observe both negative and positive morphological features we propose that the tectonic movement within the graben has a strike-slip component. Based on dating of soil samples from depressions in the outwash plain the onset of the movements are constrained to around 9.000 years BP. We conclude that the deformation of the outwash plain is related to short-term reactivations of faults related to the Tønder Graben structure following the deglaciation.
Martín-Subero, José I; Kreuz, Markus; Bibikova, Marina; Bentink, Stefan; Ammerpohl, Ole; Wickham-Garcia, Eliza; Rosolowski, Maciej; Richter, Julia; Lopez-Serra, Lidia; Ballestar, Esteban; Berger, Hilmar; Agirre, Xabier; Bernd, Heinz-Wolfram; Calvanese, Vincenzo; Cogliatti, Sergio B; Drexler, Hans G; Fan, Jian-Bing; Fraga, Mario F; Hansmann, Martin L; Hummel, Michael; Klapper, Wolfram; Korn, Bernhard; Küppers, Ralf; Macleod, Roderick A F; Möller, Peter; Ott, German; Pott, Christiane; Prosper, Felipe; Rosenwald, Andreas; Schwaenen, Carsten; Schübeler, Dirk; Seifert, Marc; Stürzenhofecker, Benjamin; Weber, Michael; Wessendorf, Swen; Loeffler, Markus; Trümper, Lorenz; Stein, Harald; Spang, Rainer; Esteller, Manel; Barker, David; Hasenclever, Dirk; Siebert, Reiner
2009-03-12
Lymphomas are assumed to originate at different stages of lymphocyte development through chromosomal aberrations. Thus, different lymphomas resemble lymphocytes at distinct differentiation stages and show characteristic morphologic, genetic, and transcriptional features. Here, we have performed a microarray-based DNA methylation profiling of 83 mature aggressive B-cell non-Hodgkin lymphomas (maB-NHLs) characterized for their morphologic, genetic, and transcriptional features, including molecular Burkitt lymphomas and diffuse large B-cell lymphomas. Hierarchic clustering indicated that methylation patterns in maB-NHLs were not strictly associated with morphologic, genetic, or transcriptional features. By supervised analyses, we identified 56 genes de novo methylated in all lymphoma subtypes studied and 22 methylated in a lymphoma subtype-specific manner. Remarkably, the group of genes de novo methylated in all lymphoma subtypes was significantly enriched for polycomb targets in embryonic stem cells. De novo methylated genes in all maB-NHLs studied were expressed at low levels in lymphomas and normal hematopoietic tissues but not in nonhematopoietic tissues. These findings, especially the enrichment for polycomb targets in stem cells, indicate that maB-NHLs with different morphologic, genetic, and transcriptional background share a similar stem cell-like epigenetic pattern. This suggests that maB-NHLs originate from cells with stem cell features or that stemness was acquired during lymphomagenesis by epigenetic remodeling.
Tyagi, Neelam; Sutton, Elizabeth; Hunt, Margie; Zhang, Jing; Oh, Jung Hun; Apte, Aditya; Mechalakos, James; Wilgucki, Molly; Gelb, Emily; Mehrara, Babak; Matros, Evan; Ho, Alice
2017-02-01
Capsular contracture (CC) is a serious complication in patients receiving implant-based reconstruction for breast cancer. Currently, no objective methods are available for assessing CC. The goal of the present study was to identify image-based surrogates of CC using magnetic resonance imaging (MRI). We analyzed a retrospective data set of 50 patients who had undergone both a diagnostic MRI scan and a plastic surgeon's evaluation of the CC score (Baker's score) within a 6-month period after mastectomy and reconstructive surgery. The MRI scans were assessed for morphologic shape features of the implant and histogram features of the pectoralis muscle. The shape features, such as roundness, eccentricity, solidity, extent, and ratio length for the implant, were compared with the Baker score. For the pectoralis muscle, the muscle width and median, skewness, and kurtosis of the intensity were compared with the Baker score. Univariate analysis (UVA) using a Wilcoxon rank-sum test and multivariate analysis with the least absolute shrinkage and selection operator logistic regression was performed to determine significant differences in these features between the patient groups categorized according to their Baker's scores. UVA showed statistically significant differences between grade 1 and grade ≥2 for morphologic shape features and histogram features, except for volume and skewness. Only eccentricity, ratio length, and volume were borderline significant in differentiating grade ≤2 and grade ≥3. Features with P<.1 on UVA were used in the multivariate least absolute shrinkage and selection operator logistic regression analysis. Multivariate analysis showed a good level of predictive power for grade 1 versus grade ≥2 CC (area under the receiver operating characteristic curve 0.78, sensitivity 0.78, and specificity 0.82) and for grade ≤2 versus grade ≥3 CC (area under the receiver operating characteristic curve 0.75, sensitivity 0.75, and specificity 0.79). The morphologic shape features described on MR images were associated with the severity of CC. MRI has the potential to further improve the diagnostic ability of the Baker score in breast cancer patients who undergo implant reconstruction. Copyright © 2016 Elsevier Inc. All rights reserved.
Debris avalanches and slumps on the margins of volcanic domes on Venus: Characteristics of deposits
NASA Technical Reports Server (NTRS)
Bulmer, M. H.; Guest, J. E.; Beretan, K.; Michaels, Gregory A.; Saunders, R. Stephen
1992-01-01
Modified volcanic domes, referred to as collapsed margin domes, have diameters greater than those of terrestrial domes and were therefore thought to have no suitable terrestrial analogue. Comparison of the collapsed debris using the Magellan SAR images with volcanic debris avalanches on Earth has revealed morphological similarities. Some volcanic features identified on the seafloor from sonar images have diameters similar to those on Venus and also display scalloped margins, indicating modification by collapse. Examination of the SAR images of collapsed dome features reveals a number of distinct morphologies to the collapsed masses. Ten examples of collapsed margin domes displaying a range of differing morphologies and collapsed masses have been selected and examined.
Three-dimensional echocardiography of congenital abnormalities of the left atrioventricular valve.
Rice, Kathryn; Simpson, John
2015-03-01
Congenital abnormalities of the left atrioventricular (AV) valve are a significant diagnostic challenge. Traditionally, reliance has been placed on two-dimensional echocardiographic (2DE) imaging to guide recognition of the specific morphological features. Real-time 3DE can provide unique views of the left AV valve with the potential to improve understanding of valve morphology and function to facilitate surgical planning. This review illustrates the features of congenital abnormalities of the left AV valve assessed by 3DE. The similarities and differences in morphology between different lesions are described, both with respect to the valve itself and supporting chordal apparatus. The potential advantages as well as limitations of this technique in clinical practice are outlined.
[Multifocal tubulopapillary tumors of the kidney. Morphologic features and prognosis. Three cases].
Abdelmoula, N B; Boudawara, T; Bahloul, A; Hmida, M B; Hachicha, J; Rebai, T; Mhiri, N; Jlidi, R
1999-01-01
Tubulopapillary tumors of the kidney represent a particular group of renal tumors characterized by their less aggressive behavior. These tumors are distinguished from non papillary tumors by their morphologic, cytochemical and genotypic features. They correspond to a continuous spectrum of tumors ranging from papillary renal cell adenoma to papillary renal cell carcinoma. These TTPR show multifocal, bilateral development and chronic lesions of the kidney parenchyma in nearly all cases. The authors report three cases of multifocal TTPR, including one bilateral case. Based on analysis of these cases and a review of the literature, they discuss the histogenetic features and prognosis of TTPR.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Yuan, Ke; De Andrade, Vincent; Feng, Zhange
The presence of impurity ions is known to significantly influence mineral surface morphology during crystal growth from aqueous solution, but knowledge on impurity ion-mineral interactions during dissolution under far-from equilibrium conditions remains limited. Here we show that calcite (CaCO 3) exhibits a rich array of dissolution features in the presence of Pb. During the initial stage, calcite exhibits non-classical surface features characterized as micro pyramids developed spontaneously in acidic Pb-bearing solutions. Subsequent pseudomorphic growth of cerussite (PbCO 3) was observed, where nucleation occurred entirely within a pore space created by dissolution at the calcite/substrate interface. Uneven growth rates yielded amore » cerussite shell made of lath- or dendritic-shaped crystals. The cerussite phase was separated from the calcite by pores of less than 200 nm under transmission X-ray microscopy, consistent with the interface-coupled dissolution-precipitation mechanism. These results show that impurity metal ions exert significant control over the microscale dissolution features found on mineral surfaces and provide new insights into interpreting and designing micro structures observed in naturally-occurring and synthetic carbonate minerals by dissolution. In addition, heterogeneous micro-environments created in transport limited reactions under pore spaces may lead to unusual growth forms during crystal nucleation and precipitation.« less
A modeling analysis program for the JPL table mountain Io sodium cloud data
NASA Technical Reports Server (NTRS)
Smyth, William H.; Goldberg, Bruce A.
1988-01-01
Research in the third and final year of this project is divided into three main areas: (1) completion of data processing and calibration for 34 of the 1981 Region B/C images, selected from the massive JPL sodium cloud data set; (2) identification and examination of the basic features and observed changes in the morphological characteristics of the sodium cloud images; and (3) successful physical interpretation of these basic features and observed changes using the highly developed numerical sodium cloud model at AER. The modeling analysis has led to a number of definite conclusions regarding the local structure of Io's atmosphere, the gas escape mechanism at Io, and the presence of an east-west electric field and a System III longitudinal asymmetry in the plasma torus. Large scale stability, as well as some smaller scale time variability for both the sodium cloud and the structure of the plasma torus over a several year time period are also discussed.
Lauc, Tomislav; Fornai, Cinzia; Premužić, Zrinka; Vodanović, Marin; Weber, Gerhard W; Mašić, Boris; Rajić Šikanjić, Petra
2015-10-01
To analyse the dental remains of an individual with signs of congenital syphilis by using macroscopic observation, CBCT and micro-CT images, and the analysis of the enamel thickness. Anthropological analysis of human skeletal remains from the 16th century archaeological site Park Grič in Zagreb, Croatia discovered a female, 17-20 years old at the time of death, with dental signs supportive of congenital syphilis: mulberry molars and canine defects, as well as non-specific hypoplastic changes on incisors. The focus of the analysis was on three aspects: gross morphology, hypoplastic defects of the molars, canines and incisors, as well as enamel thickness of the upper first and second molars. The observed morphology of the first molars corresponds to the typical aspect of mulberry molars, while that of the canines is characterised by hypomineralisation. Hypoplastic grooves were observed on the incisal edges of all incisors. The enamel of the first molars is underdeveloped while in the second molars a thick-enamelled condition is observed. Our observations for the dental and skeletal evidence are supportive to a diagnosis of congenital syphilis for this specimen from XVI century Croatia. The use of CT imaging helped documenting the diagnostic features and quantifying the effect of the dental stigmata on first molars. Copyright © 2015 Elsevier Ltd. All rights reserved.
Alsaad, Khaled O; Obaidat, Nidal; Dube, Valerie; Chapman, William; Ghazarian, Danny
2009-01-01
Primary vulvar adenocarcinomas are rare tumors, and their histogenesis is not fully understood. They are classified into extramammary Paget's disease, sweat gland carcinomas, and "breast-like" adenocarcinomas of the vulva. The latter resemble adenocarcinomas arising in the breast morphologically and immunophenotypically. Rare cases of adenocarcinoma with apocrine features have been reported, and whether these neoplasms originate from the "native apocrine" sweat glands or from "anogenital mammary-like" glands are still debatable. The presence of normal mammary-like glands in the vicinity of the tumor, the transitional malignant morphological features from normal mammary-like glands and the tumor, the breast-like histological features of the tumor, and the expression of estrogen and progesterone receptors generally suggest an origin from anogenital mammary-like glands. Absence of these features points toward native apocrine sweat glands as the source of these neoplasms. In this report, we present a patient who was initially diagnosed with Paget's disease of the right vulva, which was treated by hemi-vulvectomy, and who later presented with primary vulvar apocrine adenocarcinoma with metastasis to the inguinal lymph nodes and intranodal mucinous/colloidal differentiation: a feature, to the best of our knowledge, not reported before. We also reviewed the histogenesis of the vulvar adenocarcinomas, with emphasis on the morphological features that separate the tumors arising from the anogenital mammary-like glands in the vulva from those arising from the native vulvar sweat glands.
Morphology and emplacement of a long channeled lava flow near Ascraeus Mons Volcano, Mars
NASA Astrophysics Data System (ADS)
Garry, W. Brent; Zimbelman, James R.; Gregg, Tracy K. P.
2007-08-01
Channeled lava flows, hundreds of kilometers long, are common on the lower flanks of the Tharsis Montes on Mars. Our analysis of a 690-km-long lava flow along the southwest perimeter of Ascraeus Mons shows that it was emplaced on low local slopes (<0.3°), with a deep channel (~20 m), and at high effusion rates (19,000-29,000 m3/s) calculated from the Graetz number. These parameters are similar to conditions needed to yield rapidly emplaced terrestrial flows >100 km in length, but the maximum effusion rates necessary on Earth are essentially the minimum for Martian flows. On the basis of our calculated effusion rates, the eruption duration was 3 to 7 Earth months, assuming a constant effusion rate and continuous eruption. The morphology of the Ascraeus Mons flow shows similarities to terrestrial and simulated channeled flows. Downstream changes in morphology resemble those observed in the 1907 flow, Mauna Loa Volcano, Hawaii and channeled polyethylene glycol (PEG) flows. Braided sections of the channel in the Ascraeus Mons flow contain islands which are hundreds of meters across and resemble features observed in the 1907 and 1984 flows on Mauna Loa Volcano. Crosscutting relationships suggest islands in the proximal section were shaped by thermal and mechanical erosion, whereas islands in the medial section are inferred to be material rafted by surges of lava through the channel. Overall, understanding the morphology of long lava flows on Mars is essential to the interpretation of their emplacement and constraining eruption conditions in the saddle regions of the Tharsis volcanoes.
Jia, Peng-Fei; Li, Hong-Ju; Yang, Wei-Cai
2017-01-01
Peroxisome is an essential single-membrane bound organelle in most eukaryotic cells and functions in diverse cellular processes. De novo formation, division, and turnover of peroxisomes contribute to its biogenesis, morphology, and population regulation. In plants, peroxisome plays multiple roles, including metabolism, development, and stress response. Defective peroxisome biogenesis and development retard plant growth, adaption, and reproduction. Through tracing the subcellular localization of fluorescent reporter tagged matrix protein of peroxisome, fluorescence microscopy is a reliable and fast way to detect peroxisome biogenesis. Further fine-structural observation of peroxisome by TEM enables researchers to observe the detailed ultrastructure of its morphology and spatial contact with other organelles. Pollen grain is a specialized structure where two small sperm cells are enclosed in the cytoplasm of a large vegetative cell. Two features make pollen grain a good system to study peroxisome biogenesis: indispensable requirement of peroxisome for germination on the stigma and homogeneity. Here, we describe the methods of studying peroxisome biogenesis in Arabidopsis pollen grains by fluorescent live-imaging with confocal laser scanning microscopy (CLSM) and by DAB-staining based transmission electron microscopy (TEM).
Demos, Stavros G.; Negres, Raluca A.
2016-09-08
A volume of superheated material reaching localized temperatures of the order of 1 eV and pressures of the order of 10 GPa is generated following laser-induced damage (breakdown) on the surface of transparent dielectric materials using nanosecond pulses. This leads to material ejection and the formation of a crater. To elucidate the material behaviors involved, we examined the morphologies of the ejected particles and found distinctive features that support their classification into different types. The different morphologies arise from the difference in the structure and physical properties (such as the dynamic viscosity and presence of instabilities) of the superheated andmore » surrounding affected material at the time of ejection of each individual particle. In addition, the temperature and kinetic energy of a subset of the ejected particles were found to be sufficient to initiate irreversible modification on the intercepting silica substrates. Finally, the modifications observed are associated with mechanical damage and fusion of melted particles on the collector substrate.« less
A taxonomic revision of three Chinese spurless species of genus Epimedium L. (Berberidaceae).
Liu, Shaoxiong; Liu, Linjian; Huang, Xiaofang; Zhu, Yuye; Xu, Yanqin
2017-01-01
Due to some common or similar features (e.g., small leaf, spurless, yellow flower), three Chinese species of the genus Epimedium (Berberidaceae), E. ecalcaratum , E. platypetalum , and E. campanulatum , are controversial based on morphological characteristics. In the present study, the descriptions of morphological characteristics for the three species were revised based on extensive studies and observations both in field and in herbaria. In general, E. ecalcaratum has long creeping rhizomes 1-3 mm in diameter, two alternate or opposite trifoliolate leaves, 7-14 flowers, and petals obovate and apex subacute. Epimedium platypetalum has short or long-creeping rhizomes 1-3 mm in diameter, one trifoliolate leaf, 2-6 flowers, and petals oblong and apex rounded. Epimedium campanulatum has compact rhizomes 4-6 mm in diameter, two alternate or opposite trifoliolate leaves, 15-43 flowers, and petals obovate and apex rounded. Through comparison, we found that despite the close affinity of these three species, they can be distinguished by rhizome differences, stem-leaves, the morphology of flower (e.g., petals), and the number of per inflorenscence.
A taxonomic revision of three Chinese spurless species of genus Epimedium L. (Berberidaceae)
Liu, Shaoxiong; Liu, Linjian; Huang, Xiaofang; Zhu, Yuye; Xu, Yanqin
2017-01-01
Abstract Due to some common or similar features (e.g., small leaf, spurless, yellow flower), three Chinese species of the genus Epimedium (Berberidaceae), E. ecalcaratum, E. platypetalum, and E. campanulatum, are controversial based on morphological characteristics. In the present study, the descriptions of morphological characteristics for the three species were revised based on extensive studies and observations both in field and in herbaria. In general, E. ecalcaratum has long creeping rhizomes 1–3 mm in diameter, two alternate or opposite trifoliolate leaves, 7–14 flowers, and petals obovate and apex subacute. Epimedium platypetalum has short or long-creeping rhizomes 1–3 mm in diameter, one trifoliolate leaf, 2–6 flowers, and petals oblong and apex rounded. Epimedium campanulatum has compact rhizomes 4–6 mm in diameter, two alternate or opposite trifoliolate leaves, 15–43 flowers, and petals obovate and apex rounded. Through comparison, we found that despite the close affinity of these three species, they can be distinguished by rhizome differences, stem-leaves, the morphology of flower (e.g., petals), and the number of per inflorenscence. PMID:28781550
Bearing-Foreign Material Deposition on Retrieved Co-Cr Femoral Heads: Composition and Morphology
Tikekar, Nishant M.; Heiner, Anneliese D.; Baer, Thomas E.; Kruger, Karen M.; Callaghan, John J.; Brown, Thomas D.; Lannutti, John J.
2015-01-01
Bearing-foreign material deposition onto a femoral head can occur from contact with an acetabular shell due to dislocation, reduction, or subluxation. The purpose of this study was to comprehensively characterize deposit regions on retrieved cobalt-chrome femoral heads from metal-on-polyethylene total hip arthroplasties that had experienced such adverse events. The morphology, topography, and composition of deposition regions were characterized using macrophotography, optical profilometry, scanning electron microscopy, energy dispersive spectroscopy, and X-ray photoelectron spectroscopy. The deposit areas were relatively large, they were much rougher than the surrounding undamaged clean areas, and they displayed several distinct morphologies. Titanium alloy elements were the predominant constituents. Calcium and phosphorous were also detected within the deposit areas, in a composition that could nucleate abrasive hydroxyapatite. In addition, tungsten-rich particles, likely present as tungsten carbide, were observed on top of the titanium deposits. The increased roughness associated with these deposition features would be expected to accelerate damage and wear of the opposing liner and hence accelerate the development of osteolysis. PMID:26236744
Falk, Torsten; Strazdas, Lori A.; Borders, Rebecca S.; Kilani, Ramsey K.; Yool, Andrea J.
2010-01-01
High-density cultures of mammalian neurons offer a model system for studies of brain development, but the morphological features of individual neurons is difficult to ascertain. We show that a herpes virus vector expressing a bioluminescent protein allows detailed morphometric analyses of living neurons in complex culture environments. Expression of enhanced green fluorescent protein (eGFP) was constitutively driven in neurons using the herpes simplex virus amplicon system. This system allowed us to make novel observations regarding development in high-density cultures from rat hippocampus and cerebellum. After the phase of initial neurite outgrowth, maturing neurons continue to show rapid remodeling of the neurite branches (0.79 ± 0.11 μm/h per neurite; mean ± SEM, n=8), and displacement of the soma within the neurite arbor (1.35 ± 0.74 μm/h). These results demonstrate that a substantial capacity for morphological plasticity persists in maturing mammalian CNS neurons after cessation of net neurite outgrowth in early development. PMID:20811504
Mastropasqua, Leonardo; Toto, Lisa; Vecchiarino, Luca; Di Nicola, Marta; Mastropasqua, Rodolfo
2011-01-01
To compare functional and morphological outcomes of 1.8-mm versus 2.2-mm microincision coaxial cataract surgery (MCCS). Thirty eyes of 30 patients that underwent MCCS were randomized to two groups: 1.8-mm MCCS (group 1: 15 eyes) and 2.2-mm MCCS (group 2: 15 eyes). There were no significant between-group differences in uncorrected visual acuity, best-corrected visual acuity, keratometric astigmatism, and endothelial cell count. One day postoperatively, a greater increase of corneal thickness at the incision site was observed in group 1 compared to group 2 using anterior segment optical coherence tomography with no significant differences in tunnel morphometric features and confocal microscopy showed more tunnel edema in group 1 versus group 2 that resolved in both groups. Both 1.8- and 2.2-mm torsional MCCS were safe and efficient with easy surgical maneuvers and excellent functional and morphological results; 1.8-mm MCCS induced slightly greater tunnel edema shortly after surgery that resolved in the medium term. Copyright 2011, SLACK Incorporated.
Sawai, Yuki; Nagumo, Tamotsu; Nelson, Alan R.
2016-01-01
Light and electron microscope observations show that a brackish diatom taxon should be classified as a new species of a new genus; Pseudofrustulia lancea gen. et sp. nov. We propose separating Pseudofrustulia from other similar genera such as Frickea, Frustulia, Amphipleura, Muelleria, and Envekadea on the basis of its thickened axial ribs, raphe endings, axial costae, morphology of helictoglossa, size of striae on valve surfaces, and areolae on the inner side between its axial ribs and raphe. Girdle bands may be another diagnostic feature for the separation of Pseudofrustulia from related taxa, but more detailed observations using SEM images are required to determine if bands are diagnostic.
The Martian Outflow Channels: Mgs Sheds New Light On Viking and Pathfinder Results
NASA Astrophysics Data System (ADS)
Lanz, J.; Jaumann, R.
The Mars Global Surveyor (MGS) Mission has, as most successful missions before, given stunningly new insights in the processes that shaped the Martian surface. But how do these findings and observations fit in the context of our pre-MGS knowledge? and do they fit at all? Combining data from the Viking, Pathfinder and MGS Missions, erosion processes in the circum-Chryse Region have been newly and extensively examined. Maximum discharge rates and flow velocities within the major outflow channels were calculated as well as sediment transport and sediment volumes eroded by the flows evaluating the erosion balance of the region. In a second step a detailed study of the available high resolution MOC-Images and lower resolution MOC and Viking context images was performed to evaluate the geologic and morphologic inventory of the outflow chan- nels. Focusing on morphologic and hydrologic differences to terrestrial outflow chan- nels as well as differences to earlier pre-MGS studies, theories and hypothesis con- cerning the outflow channels have been tested for their validity. New hydrologic cal- culations e.g. give different results than previously measured (e.g. Carr 1979, Robin- son &Tanaka 1990, Komatsu &Baker 1997). Maximum discharge rates are generally smaller (see also Williams et al. 2000), in some cases up to a factor of 2 to 3 (e.g. Ares Vallis), having a strong impact on the northern ocean theory. Some morphologic fea- tures that are typical for terrestrial flood features (such as inner channels, bar deposits, gravel dunes, etc) could not or not clearly be identified in any of the large outflow channels even in high resolution MOC-imagery. Younger resurfacing processes might have covered or obscured them. Others are hard to distinguish from non-fluvial, i.e. eo- lian, features from satellite images. Nevertheless, the overall absence of such features in the outflow channels is striking and shows again that processes on Mars differ sig- nificantly from those on Earth and similar features might well have different origins. A simple comparison of similarities only, will inevitably be misleading or incomplete.
NASA Astrophysics Data System (ADS)
Dhingra, D.; Head, J. W., III; Pieters, C. M.
2014-12-01
We have completed high resolution geological mapping of impact melt deposits at the young lunar complex craters (<1 billion years) Copernicus, Jackson and Tycho using data from recent missions. Crater floors being the largest repository of impact melt, we have mapped their morphological diversity expressed in terms of varied surface texture, albedo, character and occurrence of boulder units as well as relative differences in floor elevation. Examples of wall and rim impact melt units and their relation to floor units have also been mapped. Among the distinctive features of these impact melt deposits are: 1) Impact Melt Wave Fronts: These are extensive (sometimes several kilometers in length) and we have documented their occurrence and distribution in different parts of the crater floor at Jackson and Tycho. These features emphasize melt mobility and style of emplacement during the modification stage of the craters. 2) Variations in Floor Elevations: Spatially extensive and coherent sections of crater floors have different elevations at all the three craters. The observed elevation differences could be caused by subsidence due to cooling of melt and/or structural failure, together with a contribution from regional slope. 3) Melt-Covered Megablocks: We also observe large blocks/rock-fragments (megablocks) covered in impact melt, which could be sections of collapsed wall or in some cases, subdued sections of central peaks. 4) Melt-Covered Central Peaks: Impact melt has also been mapped on the central peaks but varies in spatial extent among the craters. The presence of melt on peaks must be taken into account when interpreting peak mineralogy as exposures of deeper crust. 5) Boulder Distribution: Interesting trends are observed in the distribution of boulder units of various sizes; some impact melt units have spatially extensive boulders, while boulder distribution is very scarce in other units on the floor. We interpret these distributions to be influenced by a) the differential collapse of the crater walls during the modification stage, and b) the amount of relative melt volume retained in different parts of the crater floor. These observations provide important documentation of the morphological diversity and better understanding of the emplacement and final distribution of impact melt deposits.
Application of optimized multiscale mathematical morphology for bearing fault diagnosis
NASA Astrophysics Data System (ADS)
Gong, Tingkai; Yuan, Yanbin; Yuan, Xiaohui; Wu, Xiaotao
2017-04-01
In order to suppress noise effectively and extract the impulsive features in the vibration signals of faulty rolling element bearings, an optimized multiscale morphology (OMM) based on conventional multiscale morphology (CMM) and iterative morphology (IM) is presented in this paper. Firstly, the operator used in the IM method must be non-idempotent; therefore, an optimized difference (ODIF) operator has been designed. Furthermore, in the iterative process the current operation is performed on the basis of the previous one. This means that if a larger scale is employed, more fault features are inhibited. Thereby, a unit scale is proposed as the structuring element (SE) scale in IM. According to the above definitions, the IM method is implemented on the results over different scales obtained by CMM. The validity of the proposed method is first evaluated by a simulated signal. Subsequently, aimed at an outer race fault two vibration signals sampled by different accelerometers are analyzed by OMM and CMM, respectively. The same is done for an inner race fault. The results show that the optimized method is effective in diagnosing the two bearing faults. Compared with the CMM method, the OMM method can extract much more fault features under strong noise background.
Carnacina, Iacopo; Larrarte, Frédérique; Leonardi, Nicoletta
2017-04-01
The performance of sewer networks has important consequences from an environmental and social point of view. Poor functioning can result in flood risk and pollution at a large scale. Sediment deposits forming in sewer trunks might severely compromise the sewer line by affecting the flow field, reducing cross-sectional areas, and increasing roughness coefficients. In spite of numerous efforts, the morphological features of these depositional environments remain poorly understood. The interface between water and sediment remains inefficiently identified and the estimation of the stock of deposit is frequently inaccurate. In part, this is due to technical issues connected to difficulties in collecting accurate field measurements without disrupting existing morphologies. In this paper, results from an extensive field campaign are presented; during the campaign a new survey methodology based on acoustic techniques has been tested. Furthermore, a new algorithm for the detection of the soil-water interface, and therefore for the correct esteem of sediment stocks is proposed. Finally, results in regard to bed topography, and morphological features at two different field sites are presented and reveal that a large variability in bed forms is present along sewer networks. Copyright © 2017 Elsevier Ltd. All rights reserved.
Martian Impact Craters as Revealed by MGS and Odyssey
NASA Technical Reports Server (NTRS)
Barlow, N. G.
2005-01-01
A variety of ejecta and interior morphologies were revealed for martian impact craters by Viking imagery. Numerous studies have classified these ejecta and interior morphologies and looked at how these morphologies correlate with crater diameter, latitude, terrain, and elevation [1, 2, 3, 4]. Many of these features, particularly the layered (fluidized) ejecta morphologies and central pits, have been proposed to result when the crater formed in target material containing high concentrations of volatiles. The Catalog of Large Martian Impact Craters was originally derived from the Viking 1:2,000,000 photomosaics and contains information on 42,283 impact craters 5-km diameter distributed across the entire martian surface. The information in this Catalog has been used to study the distributions of craters displaying specific ejecta and interior morphologies in an attempt to understand the environmental conditions which give rise to these features and to estimate the areal and vertical extents of subsurface volatile reservoirs [4, 5]. The Catalog is currently undergoing revision utilizing Mars Global Surveyor (MGS) and Mars Odyssey data [6]. The higher resolution multispectral imagery is resulting in numerous revisions to the original classifications and the addition of new elemental, thermophysical, and topographic data is allowing new insights into the environmental conditions under which these features form. A few of the new results from analysis of data in the revised Catalog are discussed below.
Sobecka, E; Szostakowska, B; MacKenzie, K; Hemmingsen, W; Prajsnar, S; Eydal, M
2012-03-01
Previous studies have shown considerable variability in morphological features and the existence of genetically distinct sibling species in the acanthocephalan Echinorhynchus gadi Zoega in Müller, 1776. The aim of the present study was to follow up and extend those earlier studies by using a combination of DNA analysis and morphometrics to investigate differences between samples of E. gadi from Atlantic cod Gadus morhua L. caught at five fishing grounds in the Baltic Sea and three in different parts of the North Atlantic. Twelve morphological features were measured in 431 specimens of E. gadi, 99 individuals were studied by polymerase chain reaction-restriction fragment length polymorphosm (PCR-RFLP), and selected PCR products were sequenced. The molecular analyses showed the nucleotide sequences of E. gadi rDNA from cod caught at all the sampling sites to be identical. The comparative morphological study, in contrast, revealed significant differences between samples of E. gadi from different sampling sites and showed the separation of E. gadi into two groups corresponding approximately to the systematic classification of cod into the two subspecies, Atlantic G. morhua morhua and Baltic G. morhua callarias. The E. gadi infrapopulation size had a significant effect on some of the morphological features. The results are discussed in relation to cod population biology, the hydrography of the study area and the history of the Baltic Sea formation.
Wirkner, Christian S; Göpel, Torben; Runge, Jens; Keiler, Jonas; Klussmann-Fricke, Bastian-Jesper; Huckstorf, Katarina; Scholz, Stephan; Mikó, István; J Yoder, Matthew; Richter, Stefan
2017-09-01
Morphology, the oldest discipline in the biosciences, is currently experiencing a renaissance in the field of comparative phenomics. However, morphological/phenotypic research still suffers on various levels from a lack of standards. This shortcoming, first highlighted as the "linguistic problem of morphology", concerns the usage of terminology and also the need for formalization of morphological descriptions themselves, something of paramount importance not only to the field of morphology but also when it comes to the use of phenotypic data in systematics and evolutionary biology. We therefore argue, that for morphological descriptions, the basis of all systematic and evolutionary interpretations, ontologies need to be utilized which are based exclusively on structural qualities/properties and which in no case include statements about homology and/or function. Statements about homology and function constitute interpretations on a different or higher level. Based on these "anatomy ontologies", further ontological dimensions (e.g., referring to functional properties or homology) may be exerted for a broad use in evolutionary phenomics. To this end we present the first organ-based ontology for the most species-rich animal group, the Arthropoda. Our Ontology of Arthropod Circulatory Systems (OArCS) contains a comprehensive collection of 383 terms (i.e., labels) tied to 296 concepts (i.e., definitions) collected from the literature on phenotypic aspects of circulatory organ features in arthropods. All of the concepts used in OArCS are based exclusively on structural features, and in the context of the ontology are independent of homology and functional assumptions. We cannot rule out that in some cases, terms are used which in traditional usage and previous accounts might have implied homology and/or function (e.g. heart, sternal artery). Concepts are composed of descriptive elements that are used to classify observed instances into the organizational framework of the ontology. That is, descriptions in ontologies are only descriptions of individuals if they are necessary/and or sufficient representations of attributes (independently) observed and recorded for an individual. In addition, we here present for the first time an entirely new approach to formalizing phenotypic research, a semantic model for the description of a complex organ system in a highly disparate taxon, the arthropods. We demonstrate this with a formalized morphological description of the hemolymph vascular system in one specimen of the European garden spider Araneus diadematus. Our description targets five categories of descriptive statement: "position", "spatial relationships", "shape", "constituents", and "connections", as the corresponding formalizations constitute exemplary patterns useful not only when talking about the circulatory system, but also in descriptions in general. The downstream applications of computer-parsable morphological descriptions are widespread, with their core utility being the fact that they make it possible to compare collective description sets in computational time, that is, very quickly. Among other things, this facilitates the identification of phenotypic plasticity and variation when single individuals are compared, the identification of those traits which correlate between and within taxa, and the identification of links between morphological traits and genetic (using GO, Gene Ontology) or environmental (using ENVO, Environmental Ontology) factors. [Arthropoda; concept; function; hemolymph vascular system; homology; terminology.]. © The Author(s) 2017. Published by Oxford University Press, on behalf of the Society of Systematic Biologists. All rights reserved. For Permissions, please email: journals.permissions@oup.com.