North American sturgeon otolith morphology

USGS Publications Warehouse

Chalupnicki, Marc A.; Dittman, Dawn E.

2016-01-01

Accurate expedient species identification of deceased sturgeon (Acipenseridae) when external physical characteristic analysis is inconclusive has become a high priority due to the endangered or threatened status of sturgeon species around the world. Examination of otoliths has provided useful information to aid in population management, age and size-class analysis, understanding predator–prey interactions, and archeological research in other fish species. The relationship between otolith characteristics and sturgeon species has remained unknown. Therefore, we analyzed the shape of otoliths from the eight species of sturgeon found in North America to test the utility of otolith characteristic morphology in species identification. There were distinct differences in the size and shape of the otoliths between species of sturgeon with little shape variation among individuals of the same species. The relationship between otolith length axes was linear, and most of the variability was explained by a Log (axis + 1) transformation of the x and y axes (r2 = 0.8983) using the equation y = 0.73x + 0.0612. Images of otoliths from all eight North American species are presented to assist in the identification process.

Reflectance-based determination of age and species of blowfly puparia.

PubMed

Voss, Sasha C; Magni, Paola; Dadour, Ian; Nansen, Christian

2017-01-01

Forensic entomology is primarily concerned with the estimation of time since death and involves determination of the age of immature insects colonising decomposing remains. Accurate age determination of puparia is usually accomplished by dissection, which means destructive sampling of evidence. As part of improving abilities to correctly identify species and developmental age, it is highly desirable to have available non-destructive methods. In this study, we acquired external hyperspectral imaging (HSI) data (77 spectral bands, 389-892 nm) from the dorsal and ventral sides of individual puparia of two species of blowfly (Diptera: Calliphoridae), Calliphora dubia Macquart 1855 and Chrysomya rufifacies Macquart 1842. Puparia were dissected to determine the presence/absence of eight internal morphological development characteristics (legs, wings, labella, abdominal segments, antennae, thoracic bristles, orbital/facial bristles and eye colour and arista). Based on linear discriminant analysis and independent validation of HSI data, reflectance features from puparia could be used to successfully (1) distinguish the two species (classification accuracy = 92.5 %), (2) differentiate dorsal and ventral sides of puparia (classification accuracy C. dubia = 81.5 %; Ch. rufifacies = 89.2 %) and (3) predict the presence of these morphological characteristics and therefore the developmental stage of puparia (average classification accuracy using dorsal imaging: C. dubia = 90.3 %; Ch. rufifacies = 94.0 %). The analytical approach presented here provides proof of concept for a direct puparial age relationship (i.e. days since the onset of pupation) between external puparial reflectance features and internal morphological development. Furthermore, this approach establishes the potential for further refinement by using a non-invasive technique to determine the age and developmental stage of blowflies of forensic importance.

[Phosphatidylserine externalization and functional-morphological impairment of sperm in men with long barren marriage].

PubMed

Ploskonos, M V

2016-08-01

To identify the relationship between phosphatidylserine externalization, as an early marker of apoptosis, and functional and morphological sperm impairment in infertile men to subsequently evaluate the effect of apoptosis on sperm fertility. Ejaculates of 18 fertile and 78 subfertile men were examined. Phosphatidylserine externalization was detected by staining the sperm with fluorochrome conjugated Annexin V (AnV-FITC) and propidium iodide using fluorescence microscopy. and conclusions: Ejaculates of fertile and subfertile men differed in the percentage of annexin-V-positive sperm. The correlation of (AnV+/PI+) - sperm of subfertile men with sperm concentration, motility and defects of sperm morphology shows the adverse effects of apoptosis on sperm quality and suggests that phosphatidylserine externalization is a factor for reducing sperm fertility.

Morphological and chemical variation of Stemona tuberosa from southern China - Evidence for heterogeneity of this medicinal plant species.

PubMed

Chen, G; Brecker, L; Felsinger, S; Cai, X-H; Kongkiatpaiboon, S; Schinnerl, J

2017-09-01

The occurrence of bioactive alkaloids and tocopherols was studied in 15 different provenances of Stemona tuberosa Lour. collected in southern China, to examine chemical variation of individuals that show notable differences in flower characteristics. Morphological variations stimulated examination of chemical characteristics of these individuals. Methanolic root extracts of 15 individuals of S. tuberosa were comparatively assessed with HPLC-UV-DAD/ELSD. Five of seven compounds were co-chromatographically identified. Two compounds were isolated and their structure elucidated using NMR and MS. Amounts of alkaloids and tocopherols were determined using HPLC-UV-DAD/ELSD with the external standard method. Five alkaloids, tuberostemonine (1), tuberostemonine A (2), neotuberostemonine (3), tuberostemonine N (4), stemoninine (5) and two 3,4-dehydrotocopherol derivatives were identified. Within S. tuberosa alkaloid accumulation tends either towards tuberostemonine (1) or stemoninine (5). All individuals show a notable co-occurrence of compounds 1 or 5 and 3,4-dehydro-δ-tocopherol (6). These results coincide with differences in flower morphology of S. tuberosa. Stemona tuberosa, as defined in the Flora of China, shows a remarkable variation in flower morphology and additionally in the accumulation of alkaloids. The obtained data show the need for future species delimitation to either species or subspecies level. © 2017 German Botanical Society and The Royal Botanical Society of the Netherlands.

Description of Rhodnius marabaensis sp. n. (Hemiptera, Reduviidae, Triatominae) from Pará State, Brazil

PubMed Central

Souza, Eder dos Santos; Von Atzingen, Noé Carlos Barbosa; Furtado, Maria Betânia; de Oliveira, Jader; Nascimento, Juliana Damieli; Vendrami, Daniel Pagotto; Gardim, Sueli; da Rosa, João Aristeu

2016-01-01

Abstract Rhodnius marabaensis sp. n. was collected on 12 May 2014 in the Murumurú Environmental Reserve in the city of Marabá, Pará State, Brazil. This study was based on previous consultation of morphological descriptions of 19 Rhodnius species and compared to the identification key for the genus Rhodnius. The examination included specimens from 18 Rhodnius species held in the Brazilian National and International Triatomine Taxonomy Reference Laboratory in the Oswaldo Cruz Institute in Rio de Janeiro, Brazil. The morphological characteristics of the head, thorax, abdomen, genitalia, and eggs have been determined. Rhodnius prolixus and Rhodnius robustus were examined in more detail because the BLAST analysis of a cyt-b sequence shows they are closely related to the new species, which also occurs in the northern region of Brazil. The most notable morphological features that distinguish Rhodnius marabaensis sp. n. are the keel-shaped apex of the head, the length of the second segment of the antennae, the shapes of the prosternum, mesosternum and metasternum, the set of spots on the abdomen, the male genitalia, the posterior and ventral surfaces of the external female genitalia, and the morphological characteristics of the eggs. Rhodnius jacundaensis Serra, Serra & Von Atzingen (1980) nomen nudum specimens deposited at the Maraba Cultural Center Foundation - MCCF were examined and considered as a synonym of Rhodnius marabaensis sp. n. PMID:27833419

Decadal period external magnetic field variations determined via eigenanalysis

NASA Astrophysics Data System (ADS)

Shore, R. M.; Whaler, K. A.; Macmillan, S.; Beggan, C.; Velímský, J.; Olsen, N.

2016-06-01

We perform a reanalysis of hourly mean magnetic data from ground-based observatories spanning 1997-2009 inclusive, in order to isolate (after removal of core and crustal field estimates) the spatiotemporal morphology of the external fields important to mantle induction, on (long) periods of months to a full solar cycle. Our analysis focuses on geomagnetically quiet days and middle to low latitudes. We use the climatological eigenanalysis technique called empirical orthogonal functions (EOFs), which allows us to identify discrete spatiotemporal patterns with no a priori specification of their geometry -- the form of the decomposition is controlled by the data. We apply a spherical harmonic analysis to the EOF outputs in a joint inversion for internal and external coefficients. The results justify our assumption that the EOF procedure responds primarily to the long-period external inducing field contributions. Though we cannot determine uniquely the contributory source regions of these inducing fields, we find that they have distinct temporal characteristics which enable some inference of sources. An identified annual-period pattern appears to stem from a north-south seasonal motion of the background mean external field distribution. Separate patterns of semiannual and solar-cycle-length periods appear to stem from the amplitude modulations of spatially fixed background fields.

Surface plasmon effect in electrodeposited diamond-like carbon films for photovoltaic application

NASA Astrophysics Data System (ADS)

Ghosh, B.; Ray, Sekhar C.; Espinoza-González, Rodrigo; Villarroel, Roberto; Hevia, Samuel A.; Alvarez-Vega, Pedro

2018-04-01

Diamond-like carbon (DLC) films and nanocrystalline silver particles containing diamond-like carbon (DLC:Ag) films were electrodeposited on n-type silicon substrate (n-Si) to prepare n-Si/DLC and n-Si/DLC:Ag heterostructures for photovoltaic (PV) applications. Surface plasmon resonance (SPR) effect in this cell structure and its overall performance have been studied in terms of morphology, optical absorption, current-voltage characteristics, capacitance-voltage characteristics, band diagram and external quantum efficiency measurements. Localized surface plasmon resonance effect of silver nanoparticles (Ag NPs) in n-Si/DLC:Ag PV structure exhibited an enhancement of ∼28% in short circuit current density (JSC), which improved the overall efficiency of the heterostructures.

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

PubMed

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

2017-08-01

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

What can morphology tell us about ecology of four invasive goby species?

PubMed

Jakubčinová, K; Simonović, P; Števove, B; Čanak Atlagić, J; Kováč, V

2017-05-01

This study presents a detailed comparative analysis of external morphology of four of the most invasive goby species in Europe (round goby Neogobius melanostomus, bighead goby Ponticola kessleri, monkey goby Neogobius fluviatilis and racer goby Ponticola gymnotrachelus) and interprets some ecological requirements of these species based on their morphological attributes. The results are evaluated within an ontogenetic context, and the morphological differences between the species are discussed in terms of the question: can special external shape adaptations help to assess the invasive potential of each species? The morphometric analyses demonstrate important differences between the four invasive gobies. Neogobius melanostomus appears to have the least specialized external morphology that may favour its invasive success: little specialization to habitat or diet means reduced restraints on overall ecological requirements. The other three species were found to possess some morphological specializations (P. kessleri to large prey, N. fluviatilis to sandy habitats and P. gymnotrachelus to macrophytes), but none of these gobies have managed to colonize such large areas or to reach such overall abundances as N. melanostomus. © 2017 The Fisheries Society of the British Isles.

Phylogenetic relationships and morphology of the Pristimantis leptolophus species group (Amphibia: Anura: Brachycephaloidea), with the recognition of a new species group in Pristimantis Jiménez de la Espada, 1870.

PubMed

González-Durán, Gustavo A; Targino, Mariane; Rada, Marco; Grant, Taran

2017-03-13

We evaluate the monophyly and phylogenetic relationships of the Pristimantis leptolophus species group and describe its external morphology, osteology, and some myological characteristics. We also compare the P. leptolophus species group to other related species groups. The P. leptolophus group is not monophyletic due to the inclusion of P. acatallelus, formerly believed to be part of the P. devillei group. The revised P. leptolophus group is composed of nine named species and six unnamed species. Based on our results, we recognize a new species group, the P. boulengeri species group, composed of eight species, many of which were previously assigned to the P. lacrimosus species group.

Generic model of morphological changes in growing colonies of fungi

NASA Astrophysics Data System (ADS)

López, Juan M.; Jensen, Henrik J.

2002-02-01

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

Statistical analysis of whole-body absorption depending on anatomical human characteristics at a frequency of 2.1 GHz.

PubMed

Habachi, A El; Conil, E; Hadjem, A; Vazquez, E; Wong, M F; Gati, A; Fleury, G; Wiart, J

2010-04-07

In this paper, we propose identification of the morphological factors that may impact the whole-body averaged specific absorption rate (WBSAR). This study is conducted for the case of exposure to a front plane wave at a 2100 MHz frequency carrier. This study is based on the development of different regression models for estimating the WBSAR as a function of morphological factors. For this purpose, a database of 12 anatomical human models (phantoms) has been considered. Also, 18 supplementary phantoms obtained using the morphing technique were generated to build the required relation. This paper presents three models based on external morphological factors such as the body surface area, the body mass index or the body mass. These models show good results in estimating the WBSAR (<10%) for families obtained by the morphing technique, but these are still less accurate (30%) when applied to different original phantoms. This study stresses the importance of the internal morphological factors such as muscle and fat proportions in characterization of the WBSAR. The regression models are then improved using internal morphological factors with an estimation error of approximately 10% on the WBSAR. Finally, this study is suitable for establishing the statistical distribution of the WBSAR for a given population characterized by its morphology.

Statistical analysis of whole-body absorption depending on anatomical human characteristics at a frequency of 2.1 GHz

NASA Astrophysics Data System (ADS)

El Habachi, A.; Conil, E.; Hadjem, A.; Vazquez, E.; Wong, M. F.; Gati, A.; Fleury, G.; Wiart, J.

2010-04-01

In this paper, we propose identification of the morphological factors that may impact the whole-body averaged specific absorption rate (WBSAR). This study is conducted for the case of exposure to a front plane wave at a 2100 MHz frequency carrier. This study is based on the development of different regression models for estimating the WBSAR as a function of morphological factors. For this purpose, a database of 12 anatomical human models (phantoms) has been considered. Also, 18 supplementary phantoms obtained using the morphing technique were generated to build the required relation. This paper presents three models based on external morphological factors such as the body surface area, the body mass index or the body mass. These models show good results in estimating the WBSAR (<10%) for families obtained by the morphing technique, but these are still less accurate (30%) when applied to different original phantoms. This study stresses the importance of the internal morphological factors such as muscle and fat proportions in characterization of the WBSAR. The regression models are then improved using internal morphological factors with an estimation error of approximately 10% on the WBSAR. Finally, this study is suitable for establishing the statistical distribution of the WBSAR for a given population characterized by its morphology.

Scattering and radiative properties of complex soot and soot-containing particles

NASA Astrophysics Data System (ADS)

Liu, L.; Mishchenko, M. I.; Mackowski, D. W.; Dlugach, J.

2012-12-01

Tropospheric soot and soot containing aerosols often exhibit nonspherical overall shapes and complex morphologies. They can externally, semi-externally, and internally mix with other aerosol species. This poses a tremendous challenge in particle characterization, remote sensing, and global climate modeling studies. To address these challenges, we used the new numerically exact public-domain Fortran-90 code based on the superposition T-matrix method (STMM) and other theoretical models to analyze the potential effects of aggregation and heterogeneity on light scattering and absorption by morphologically complex soot containing particles. The parameters we computed include the whole scattering matrix elements, linear depolarization ratios, optical cross-sections, asymmetry parameters, and single scattering albedos. It is shown that the optical characteristics of soot and soot containing aerosols very much depend on particle sizes, compositions, and aerosol overall shapes. The soot particle configurations and heterogeneities can have a substantial effect that can result in a significant enhancement of extinction and absorption relative to those computed from the Lorenz-Mie theory. Meanwhile the model calculated information combined with in-situ and remote sensed data can be used to constrain soot particle shapes and sizes which are much needed in climate models.

Comprehensive Understanding of Ductility Loss Mechanisms in Various Steels with External and Internal Hydrogen

NASA Astrophysics Data System (ADS)

Takakuwa, Osamu; Yamabe, Junichiro; Matsunaga, Hisao; Furuya, Yoshiyuki; Matsuoka, Saburo

2017-11-01

Hydrogen-induced ductility loss and related fracture morphologies are comprehensively discussed in consideration of the hydrogen distribution in a specimen with external and internal hydrogen by using 300-series austenitic stainless steels (Types 304, 316, 316L), high-strength austenitic stainless steels (HP160, XM-19), precipitation-hardened iron-based super alloy (A286), low-alloy Cr-Mo steel (JIS-SCM435), and low-carbon steel (JIS-SM490B). External hydrogen is realized by a non-charged specimen tested in high-pressure gaseous hydrogen, and internal hydrogen is realized by a hydrogen-charged specimen tested in air or inert gas. Fracture morphologies obtained by slow-strain-rate tensile tests (SSRT) of the materials with external or internal hydrogen could be comprehensively categorized into five types: hydrogen-induced successive crack growth, ordinary void formation, small-sized void formation related to the void sheet, large-sized void formation, and facet formation. The mechanisms of hydrogen embrittlement are broadly classified into hydrogen-enhanced decohesion (HEDE) and hydrogen-enhanced localized plasticity (HELP). In the HEDE model, hydrogen weakens interatomic bonds, whereas in the HELP model, hydrogen enhances localized slip deformations. Although various fracture morphologies are produced by external or internal hydrogen, these morphologies can be explained by the HELP model rather than by the HEDE model.

Biology and External Morphology of Immature Stages of the Butterfly, Diaethria candrena candrena

PubMed Central

Dias, Fernando M.S.; Carneiro, Eduardo; Casagrande, Mirna M.; Mielke, Olaf H.H.

2012-01-01

The biology and the external morphology of immature stages of Diaethria candrena candrena (Godart) (Lepidoptera: Nymphalidae: Biblidinae) are described. Immature D. c. candrena found on Allophylus spp. (Sapindaceae) were collected in Curitiba, Paraná, Brazil and reared in the laboratory. Morphological descriptions and illustrations are given, based on observations using electronic, stereoscopic, and optic microscopes, the latter two attached to camera lucida. Results are compared and discussed with immature stages of other species of Biblidinae described to date. PMID:22943597

Rachis morphology cannot accurately predict the mechanical performance of primary feathers in extant (and therefore fossil) feathered flyers

NASA Astrophysics Data System (ADS)

Lees, John; Garner, Terence; Cooper, Glen; Nudds, Robert

2017-02-01

It was previously suggested that the flight ability of feathered fossils could be hypothesized from the diameter of their feather rachises. Central to the idea is the unvalidated assumption that the strength of a primary flight feather (i.e. its material and structural properties) may be consistently calculated from the external diameter of the feather rachis, which is the only dimension that is likely to relate to structural properties available from fossils. Here, using three-point bending tests, the relationship between feather structural properties (maximum bending moment, Mmax and Young's modulus, Ebend) and external morphological parameters (primary feather rachis length, diameter and second moment of area at the calamus) in 180 primary feathers from four species of bird of differing flight style was investigated. Intraspecifically, both Ebend and Mmax were strongly correlated with morphology, decreasing and increasing, respectively, with all three morphological measures. Without accounting for species, however, external morphology was a poor predictor of rachis structural properties, meaning that precise determination of aerial performance in extinct, feathered species from external rachis dimensions alone is not possible. Even if it were possible to calculate the second moment of area of the rachis, our data suggest that feather strength could still not be reliably estimated.

Impacts of environmental conditions on product formation and morphology of Yarrowia lipolytica.

PubMed

Timoumi, Asma; Guillouet, Stéphane E; Molina-Jouve, Carole; Fillaudeau, Luc; Gorret, Nathalie

2018-05-01

The yeast Yarrowia lipolytica is an industrially important microorganism with distinctive physiological and metabolic characteristics. A variety of external factors (e.g., pH, temperature, and nutrient availability) influences the behavior of the yeast and may act as stress conditions which the cells must withstand and adapt. In this mini review, the impacts of environmental factors on the morphology and metabolite production by Y. lipolytica are summarized. In this regard, detailed insights into the effectors involved in the dimorphic transition of Y. lipolytica, the cultivation conditions employed, as well as the methods applied for the morphological characterization are highlighted. Concerning the metabolism products, a special focus is addressed on lipid and citric acid metabolites which have attracted significant attention in recent years. The dependence of lipid and citric acid productivity on key process parameters, such as media composition and physico-chemical variables, is thoroughly discussed. This review attempts to provide a recent update on the topic and will serve as a meaningful resource for researchers working in the field.

Application of the morpho-functional analysis of hydrobionts ( Anadara sp. cf. Anadara inaequivalvis Bivalvia) to environmental monitoring

NASA Astrophysics Data System (ADS)

Kolyuchkina, G. A.; Miljutin, D. M.

2013-03-01

The population dynamics and morphological and functional characteristics (the concentration of hemocytes in the hemolymph and the level of histopathology) of the bivalve Anadara sp. cf. Anadara inaequivalvis were studied in 2005-2007 on the North Caucasian coast of the Black Sea. A drastic decline in the abundance of the bivalves simultaneously with cadmium's exceedence in their soft tissues and bottom sediments were recorded in May of 2007. Six months before the manifestation of the population effects, morphological and functional changes (a decrease in the content of hemocytes in the hemolymph and an increase in the content of brown cells in the connective tissue and lipofuscin-like pigment granules in the digestive gland epithelium) in the bivalves were detected that were the consequences of an external effect (presumably, cadmium intoxication). Thus, the morphological and functional changes of the individual Anadaras may be a promising tool for the early detection of the impact of pollutants on benthic ecosystems.

Identification of gender in yellow perch by external morphology: validation in four geographic strains and effects of estradiol

USDA-ARS?s Scientific Manuscript database

External morphological criteria that enable the rapid determination of gender have been developed for yellow perch (Perca flavescens). Criteria are based upon 1) shape of the urogenital papilla (UGP), 2) relative size of the UGP to the anal (AN) opening, and 3) coloration of the UGP. In females, t...

External Insect Morphology: A Negative Factor in Attitudes toward Insects and Likelihood of Incorporation in Future Science Education Settings

ERIC Educational Resources Information Center

Wagler, Ron; Wagler, Amy

2012-01-01

This study investigated if the external morphology of an insect had a negative effect on United States (US) preservice elementary teacher's attitudes toward insects and beliefs concerning the likelihood of incorporating insects into future science education settings. 270 US kindergarten through sixth grade preservice elementary teachers…

Understanding morphological variability in a taxonomic context in Chilean diplomystids (Teleostei: Siluriformes), including the description of a new species

PubMed Central

2017-01-01

Following study of the external morphology and its unmatched variability throughout ontogeny and a re-examination of selected morphological characters based on many specimens of diplomystids from Central and South Chile, we revised and emended previous specific diagnoses and consider Diplomystes chilensis, D. nahuelbutaensis, D. camposensis, and Olivaichthys viedmensis (Baker River) to be valid species. Another group, previously identified as Diplomystes sp., D. spec., D. aff. chilensis, and D. cf. chilensis inhabiting rivers between Rapel and Itata Basins is given a new specific name (Diplomystes incognitus) and is diagnosed. An identification key to the Chilean species, including the new species, is presented. All specific diagnoses are based on external morphological characters, such as aspects of the skin, neuromast lines, and main lateral line, and position of the anus and urogenital pore, as well as certain osteological characters to facilitate the identification of these species that previously was based on many internal characters. Diplomystids below 150 mm standard length (SL) share a similar external morphology and body proportions that make identification difficult; however, specimens over 150 mm SL can be diagnosed by the position of the urogenital pore and anus, and a combination of external and internal morphological characters. According to current knowledge, diplomystid species have an allopatric distribution with each species apparently endemic to particular basins in continental Chile and one species (O. viedmensis) known only from one river in the Chilean Patagonia, but distributed extensively in southern Argentina. PMID:28224053

Morphological Profiles of Playing Positions in Defense and Offense in Professional Men's Handball.

PubMed

Ante, Burger; Nikola, Foretić; Marijana Čavala

2015-07-01

The main scope of the study is concerned with the morphological profiles of playing positions in defense, offense and the combinations of these two phases of the game. Furthermore, study attempted to identify the difference between the morphological profiles of the individual playing positions. Entity sample of the study consist of the 148 players that participated in 45 matches of the World Men's Handball Championship which took place in Croatia in 2009. The study dealt with the differences between playing positions concerning basic morphological characteristics which are due to the selection based on roles and tasks that need to be carried out in each position. Moreover, morphological similarity of playing positions in offense and defense was noticed. It was determined that wing players play dominantly in the position of left back, external players in the position of right and center back whereas pivots participate in the positions of center, back and center forward positions in defense. Morphological profiles of playing positions in defense, offense and in the combination of these two phases of the game were determined. Identical positions on different sides in offense (left-right wing player, left-right back player) have shown that these positions are quite similar when it comes to morphological profile and playing position in defense. It can be concluded that some playing positions in offense are accompanied by the respective positions in defense. All positions are characterized by one or two morphological profiles.

Bubbles and Dust: Dissolution Rates of Unhydrated Volcanic Ash as a Function of Morphology, Composition, and Particle Size

NASA Astrophysics Data System (ADS)

Wygel, C. M.; Sahagian, D. L.

2017-12-01

Volcanic eruptions are natural hazards due to their explosive nature and widespread transportation and deposition of ash particles. After deposition and subsequent leaching in soils or water bodies, ash deposition positively (nutrients) and negatively (contaminants) impacts the health of flora and fauna, including humans. The effects of ash leachates have been difficult to replicate in field and laboratory studies due to the many complexities and differences between ash particles. Ash morphology is characteristic for each eruption, dependent upon eruption energy, and should play a critical role in determining leaching rates. Morphology reflects overall particle surface area, which is strongly influenced by the presence of surface dust. In addition, ash composition, which in part controls morphology and particle size, may also affect leaching rates. This study determines the extent to which ash morphology, surface area, composition, and particle size control ash dissolution rates. Further, it is necessary to determine whether compound vesicular ash particles permit water into their interior structures to understand if both the internal and external surface areas are available for leaching. To address this, six fresh, unhydrated ash samples from diverse volcanic environments and a large range in morphology, from Pele's spheres to vesicular compound ash, are tested in the laboratory. Ash morphology was characterized on the Scanning Electron Microscope (SEM) before and after leaching and surface area was quantified by Brunauer Emmett Teller (BET) analysis and with geometric calculations. Column Leachate Tests (CLT) were conducted to compare leaching rates over a range of basaltic to silicic ashes as a function of time and surface area, to recreate the effects of ash deposition in diverse volcanic environments. After the CLT, post-leaching water analyses were conducted by Ion Coupled Plasma-Mass Spectrometry (ICP-MS) and Ion Chromatography (IC). We find that leaching rates are correlated to characteristic surface area of ash particles.

Analysis of External Treatment Methods and Technical Characteristics of External Treatment

NASA Astrophysics Data System (ADS)

Zhang, Rui; Miao, Mingsan; Bai, Ming

2018-01-01

Chinese medicine external therapy is a treatment method of Chinese medicine with Chinese characteristics. The effect of traditional Chinese medicine external treatment, convenient operation, external treatment and technology has great prospects for development. The traditional Chinese medicine external treatment method and technical characteristics were analyzed.

Geographical variation in the skeletal morphology of red jungle fowl.

PubMed

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

2017-08-01

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

Ontogenetic development in the morphology and behavior of loach ( Misgurnus anguillicaudatus) during early life stages

NASA Astrophysics Data System (ADS)

Gao, Lei; Duan, Ming; Cheng, Fei; Xie, Songguang

2014-09-01

Loach ( Misgurnus anguillicaudatus) are a commercially important fish in China and an ideal aquaculture species. However, culturists experience high larval and juvenile mortality during mass production. To provide insight into ways to improve larviculture techniques, we describe the morphological characteristics and behavior of loach during the larval and early juvenile stages. Yolksac larvae ranged from 2.8 to 4.0 mm body length (BL) between days 0 to 4; preflexion larvae ranged from 3.6 to 5.5 mm BL between days 4 to 6; flexion larvae ranged from 4.8 to 8.1 mm BL between days 5 and 14; and postflexion larvae ranged from 7.1 to 15.7 mm BL between days 11 to 27; the minimum length and age of juveniles was 14.1 mm BL and 23 d, respectively. Loach are demersal from hatch through to the early juvenile stages. A suite of morphological characteristics (e.g., external gill filament and ventral mouth opening) and behavioral traits have developed to adapt to demersal living. We observed positive allometric growth in eye diameter, head length, head height, and pectoral fin length during the early larval stages, reflecting the priorities in the development of the organs essential for survival. Our results provide a basis for developing techniques to improve the survival of larval and juvenile loach during mass production.

A new species of broad-nosed bat Platyrrhinus Saussure, 1860 (Chiroptera:   Phyllostomidae) from the Guianan Shield.

PubMed

Velazco, Paúl M; Lim, Burton K

2014-05-16

A new species of broad-nosed bat Platyrrhinus Saussure, 1860 (Chiroptera: Phyllostomidae: Stenodermatinae) from the Guianan Shield is described based on molecular and morphological data. Previously confused with P. helleri and P. recifinus, the new taxon is currently known from only Guyana and Suriname and is most closely related to P. recifinus from eastern Brazil and not to the two sympatric species (P. fusciventris and P. incarum) also recently recognized as distinct from P. helleri. Morphometrically the new taxon overlaps with the smaller species of the genus (P. angustirostris, P. brachycephalus, P. fusciventris, P. helleri, P. incarum, and P. matapalensis), but forms a different cluster from the larger P. recifinus. Morphologically the new taxon is distinguished from its congeners by a combination of external and craniodental characteristics. Platyrrhinus now includes 21 species making it the most speciose genus in the Neotropical family Phyllostomidae.

Morphology, ecology and biogeography of Stauroneis pachycephala P.T. Cleve (Bacillariophyta) and its transfer to the genus Envekadea

USGS Publications Warehouse

Atazadeh, Islam; Edlund, Mark B.; van de Vijver, Bart; Mills, Keely; Spaulding, Sarah A.; Gell, Peter A.; Crawford, Simon; Barton, Andrew F.; Lee, Sylvia S.; Smith, Kathryn E.L.; Newall, Peter; Potapova, Marina

2014-01-01

Stauroneis pachycephala was described in 1881 from the Baakens River, Port Elizabeth, South Africa. Recently, it was found during surveys of the MacKenzie River (Victoria, Australia), the Florida Everglades (USA) and coastal marshes of Louisiana (USA). The morphology, ecology and geographic distribution of this species are described in this article. This naviculoid species is characterised by lanceolate valves with a gibbous centre, a sigmoid raphe, an axial area narrowing toward the valve ends, and capitate valve apices. The central area is a distinct stauros that is slightly widened near the valve margin. The raphe is straight and filiform, and the terminal raphe fissures are strongly deflected in opposite directions. Striae are fine and radiate in the middle of the valve, becoming parallel and eventually convergent toward the valve ends. The external surface of the valves and copulae is smooth and lacks ornamentation. We also examined the type material of S. pachycephala. Our observations show this species has morphological characteristics that fit within the genus Envekadea. Therefore, the transfer of S. pachycephala to Envekadea is proposed and a lectotype is designated.

The male bulbospongiosus muscle and its relation to the external anal sphincter.

PubMed

Peikert, Kevin; Platzek, Ivan; Bessède, Thomas; May, Christian Albrecht

2015-04-01

The bulbospongiosus muscle is part of the superficial muscular layer of the perineum and pelvic floor. Its morphology remains controversial in the literature. Therefore, we reinvestigated the fascial arrangement and fiber courses of the bulbospongiosus muscle and its topographical relation to the external anal sphincter. The perineum was dissected in 9 male cadavers (mean ± SD age 78.3 ± 10.7 years). Select samples were obtained for histology and immunohistochemistry. In 43 patients (mean age 60.7 ± 12 years) the topographical relation between the bulbospongiosus muscle and the external anal sphincter was determined by magnetic resonance imaging. The perineum contains several fascial layers consisting of elastic and collagen fibers as well as bundles of smooth muscle cells. The bulbospongiosus muscle was subdivided into a ventral and dorsal portion, which developed in 4 variants. The ventral insertion formed a morphological unity with the ischiocavernous muscle while the dorsal origin had a variable relation to the external anal sphincter (5 variants). A muscle-like or connective tissue-like connection was frequently present between the muscles. However, in some cases the muscles were completely separated. We suggest a concept of variations of bulbospongiosus muscle morphology that unifies the conflicting literature. Its ventral fiber group and the ischiocavernosus muscle form a functional and morphological unity. While the bulbospongiosus muscle and the external anal sphincter remain independent muscles, their frequent connection might have clinical implications for perineal surgery and anogenital disorders. Copyright © 2015 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.

A simple 2D biofilm model yields a variety of morphological features.

PubMed

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.

Evolutionary divergency of giant tortoises in Gal?pagos

USGS Publications Warehouse

Fritts, T.H.

1984-01-01

The giant tortoises in the Galapagos Archipelago diverge considerably in size, and in shape and other carapace characteristics. The saddleback morphotype is known only from insular faunas lacking large terrestrial predators (i.e. Galapagos and Mauritius) and in Galapagos is associated with xeric habitats where vertical feeding range and vertical reach in agonistic encounters are adaptive. The large domed morphotype is associated with relatively cool, mesic habitats where intraspecific competition for food and other resources may be less intense than in xeric habitats. Other external characteristics that differ between tortoise populations are also correlated with ecological variation. Tortoises have radiated into a mosaic of ecological conditions in the Galapagos but critical data are lacking on the role of genetic and environmental controls on phenotypic variation. Morphological divergence in tortoises is potentially a better indicator of present ecological conditions than of evolutionary relationships.

Beyond native block copolymer morphologies

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

Doerk, Gregory S.; Yager, Kevin G.

Block copolymers self-assemble into a range of canonical morphologies. Here, we review a broad range of techniques for inducing these materials to form structures beyond the ‘native’ morphologies seen in the bulk equilibrium phase diagram. Methods that exploit intrinsic encoding (molecular design) and external enforcement (directed assembly) are compared.

Beyond native block copolymer morphologies

DOE PAGES

Doerk, Gregory S.; Yager, Kevin G.

2017-09-20

Block copolymers self-assemble into a range of canonical morphologies. Here, we review a broad range of techniques for inducing these materials to form structures beyond the ‘native’ morphologies seen in the bulk equilibrium phase diagram. Methods that exploit intrinsic encoding (molecular design) and external enforcement (directed assembly) are compared.

High Throughput System for Plant Height and Hyperspectral Measurement

NASA Astrophysics Data System (ADS)

Zhao, H.; Xu, L.; Jiang, H.; Shi, S.; Chen, D.

2018-04-01

Hyperspectral and three-dimensional measurement can obtain the intrinsic physicochemical properties and external geometrical characteristics of objects, respectively. Currently, a variety of sensors are integrated into a system to collect spectral and morphological information in agriculture. However, previous experiments were usually performed with several commercial devices on a single platform. Inadequate registration and synchronization among instruments often resulted in mismatch between spectral and 3D information of the same target. And narrow field of view (FOV) extends the working hours in farms. Therefore, we propose a high throughput prototype that combines stereo vision and grating dispersion to simultaneously acquire hyperspectral and 3D information.

Polyamide microcapsules containing jojoba oil prepared by inter-facial polymerization.

PubMed

Persico, P; Carfagna, C; Danicher, L; Frere, Y

2005-08-01

Jojoba oil containing polyamide microcapsules having diameter of approximately 5 microm were prepared by inter-facial polycondensation by direct method (oil-in-water). Qualitative effects of both the formulation and the process parameters on microcapsules characteristics were investigated by SEM observations. Morphological analysis showed the dependence of the external membrane compactness on the chemical nature of the water-soluble polyamine and the oil-soluble acid polychloride: 1,6-hexamethylenediamine (HMDA) and terephthaloyl dichloride (TDC) were found to favour the production of smooth and dense surfaces. The use of ultrasonic irradiations during the dispersion step to get a further reduction of microcapsules size was also evaluated.

Research advances in reflectance spectra of plant leafs

NASA Astrophysics Data System (ADS)

Zhu, Taotao; Yang, Ting; Guo, Yanxin; Xu, Jingqi; Chang, Wandong; Fang, Siyi; Zhu, Kangkang; Xu, Tingyan

2018-02-01

Leaves are an important factor when we study plants because their water content, pigment content and nutrient content of leaves can reflect the current growth status of the whole plant. The methods of spectral diagnosis technology or image technology mainly are the pre-detection technique which can be used to invert the color, texture and spectral reflectance of the leaves. From this we can obtain the changes of the internal components and the external morphological characteristics of the plant leaves in different states changes. In this paper, the reflection spectral response mechanism of plant water content, pigment and nutrient elements at domestic and overseas are reviewed and compared.

Sharp Morphological Transitions from Nanoscale Mixed-Anchoring Patterns in Confined Nematic Liquid Crystals

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

Armas-Pérez, Julio C.; Li, Xiao; Martínez-González, José A.

Liquid crystals are known to be particularly sensitive to orientational cues provided at surfaces or interfaces. In this work, we explore theoretically, computationally, and experimentally the behavior of liquid crystals on isolated nanoscale patterns with controlled anchoring characteristics at small length scales. The orientation of the liquid crystal is controlled through the use of chemically patterned polymer brushes that are tethered to a surface. This system can be engineered with remarkable precision, and the central question addressed here is whether a characteristic length scale exists at which information encoded on a surface is no longer registered by a liquid crystal.more » To do so, we adopt a tensorial description of the free energy of the hybrid liquidcrystal surface system, and we investigate its morphology in a systematic manner. For long and narrow surface stripes, it is found that the liquid crystal follows the instructions provided by the pattern down to 100 nm widths. This is accomplished through the creation of line defects that travel along the sides of the stripes. We show that a "sharp" morphological transition occurs from a uniform undistorted alignment to a dual uniform/splay-bend morphology. The theoretical and numerical predictions advanced here are confirmed by experimental observations. Our combined analysis suggests that nanoscale patterns can be used to manipulate the orientation of liquid crystals at a fraction of the energetic cost that is involved in traditional liquid crystal-based devices. The insights presented in this work have the potential to provide a new fabrication platform to assemble low power bistable devices, which could be reconfigured upon application of small external fields.« less

Biology and external morphology of the immature stages of the butterfly Callicore pygas eucale , with comments on the taxonomy of the genus Callicore (Nymphalidae: Biblidinae)

PubMed Central

Dias, Fernando Maia Silva; Casagrande, Mirna Martins; Mielke, Olaf Hermann Hendrik

2014-01-01

Abstract The biology and the external morphology of the immature stages of Callicore pygas eucale (Fruhstorfer, 1916) (Lepidoptera: Nymphalidae: Biblidinae) are described. Immatures were collected on Allophylus edulis (Radlkofer) (Sapindales: Sapindaceae) in Curitiba, Paraná, Brazil, and reared in the laboratory. Morphological descriptions and illustrations are given based on observations through electronic, stereoscopic, and optic microscopes, the latter two attached to a camera lucida. Results are compared and discussed with the immature stages of other species of the subtribe Callicorina. Immature stages data provide further evidence that Callicore is paraphyletic and that generic limits within the Callicorina need revision. PMID:25368047

Reliability and agreement on embryo assessment: 5 years of an external quality control programme.

PubMed

Martínez-Granados, Luis; Serrano, María; González-Utor, Antonio; Ortiz, Nereyda; Badajoz, Vicente; López-Regalado, María Luisa; Boada, Montserrat; Castilla, Jose A

2018-03-01

An external quality-control programme for morphology-based embryo quality assessment, incorporating a standardized embryo grading scheme, was evaluated over a period of 5 years to determine levels of inter-observer reliability and agreement between practising clinical embryologists at IVF centres and the opinions of a panel of experts. Following Guidelines for Reporting Reliability and Agreement Studies, the Gwet index and proportion of positive (Ppos) and negative agreement were calculated. For embryo morphology assessment, a substantial degree of reliability was measured between the centres and the panel of experts (Gwet index: 0.76; 95% CI 0.70 to 0.84). The agreement was higher for good- versus poor-quality embryos. When multinucleation or vacuoles were observed, low levels of reliability were obtained (Ppos: 0.56 and 0.43, respectively). In blastocysts, the characteristic that presented the largest discrepancy was that related to the inner cell mass. In decisions about the final disposition of the embryo, reliability between centre and the panel of experts was moderate (Gwet index: 0.51; 95% CI 0.41 to 0.60). In conclusion, the ability of clinical embryologists to evaluate the presence of multinucleation and vacuoles in the early cleavage embryo, and to determine the category of the inner cell mass in blastocysts, needs to be improved. Copyright © 2017 Reproductive Healthcare Ltd. All rights reserved.

Ocimum sanctum (L.) essential oil and its lead molecules induce apoptosis in Candida albicans.

PubMed

Khan, Amber; Ahmad, Aijaz; Khan, Luqman Ahmad; Manzoor, Nikhat

2014-01-01

Manipulation of endogenous responses during programmed cell death (PCD) in fungi can lead to development of effective therapeutic strategies. In the present study, we evaluated the physiology of cell death in Candida albicans in response to Ocimum sanctum essential oil (OSEO) and its two major constituents - methyl chavicol (MET CHAV) and linalool (LIN) at varying inhibitory concentrations. Apoptotic cell death was studied on the basis of externalization of membrane phosphatidylserine (PS) revealed by annexin-V-FITC labeling, morphological alterations revealed by transmission electron microscopy and DNA fragmentation by terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) assay. Exposure of fungal cells to MIC/4 of OSEO, MET CHAV and LIN resulted in morphological features characteristic of apoptosis, while necrosis was observed at higher concentrations. Necrotic cells displayed reduced TUNEL staining and an inability to exclude propidium iodide. In addition, they lacked a defined nucleus and an intact external morphology. Exposed cells were TUNEL-positive, showed chromatin condensation and margination, nuclear envelope separation, nuclear fragmentation, cytoplasmic shrinkage and plasma membrane blebbing. A dose-dependent decrease in cytochrome c oxidase activity was observed with each compound, but the decrease was not comparable to that elicited by H2O2, eliminating the primary involvement of cytochrome c release in apoptosis thus induced. Previously reported data revealed induction of apoptosis at low concentrations as a result of oxidative insult. Studies aimed at identifying other mitochondrial factors activated during this course to mediate apoptosis will further elucidate the mechanism of antifungal action of these natural products. Copyright © 2014 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved.

The study of the dynamics of erythrocytes under the influence of an external electric field

NASA Astrophysics Data System (ADS)

Mamaeva, Sargylana N.; Maksimov, Georgy V.; Antonov, Stepan R.

2017-11-01

A mathematical model is considered for the determination of the surface charge of an erythrocyte with its shape approximated by a surface of revolution of the second order, and the investigation of the dynamics of erythrocytes under the influence of an external electric field. In the first part of this work, the electrical surface charge of the erythrocyte of the patient was calculated with the assumption that the change in the shape and size of the red blood cells leads to stabilization of the electric field, providing a normal electrostatic repulsion. In the second part of the work, the research results of dynamics of changes in the morphology of erythrocytes under the influence of an external electric field depending on the values of their surface charge and resistance of blood plasma is presented. In the course of the work, the dependence of the surface charge of red blood cells from their shape and size is presented. The determination of the relationship between the value of the charge field and the surface of erythrocytes in norm and in pathology is shown. The dependence of the velocity of the erythrocytes on the characteristics of the external electric field, surface charge of the erythrocyte and properties of the medium is obtained. The results of this study can be applied indirectly to diagnose diseases and to develop recommendations for experimental studies of hemodynamics under the influence of various external physical factors.

Variation in the myosoricine hand skeleton and its implications for locomotory behavior (Eulipotyphla: Soricidae)

USGS Publications Warehouse

Woodman, Neal; Stabile, Frank A.

2015-01-01

Substrate use and locomotory behavior of mammals are typically reflected in external characteristics of the forefeet, such as the relative proportions of the digits and claws. Although skeletal anatomy of the forefeet can be more informative than external characters, skeletons remain rare in systematic collections. This is particularly true for the Myosoricinae (Eulipotyphla: Soricidae), a small clade of African shrews that includes both ambulatory forest shrews (Myosorex) and semifossorial mole shrews (Surdisorex). Most species in this subfamily have restricted distributions, and their behavior and ecology are mostly unstudied. To better understand the potential range of locomotory behavior among myosoricines, we used digital x-rays to image and facilitate measuring the forefoot skeletons of 9 species. As a gauge of potential variation, we compared them with the ambulatory talpid Uropsilus (Talpidae) and the semifossorial talpid Neurotrichus. The hand morphologies of myosoricines show a graded range of potential substrate use between ambulatory and semifossorial. Some of these shrews exhibit adaptations for increased burrowing efficiency that are similar to those seen in talpids and other mammals, such as longer, broader distal phalanges and claws and shorter, wider metacarpals and proximal and middle phalanges. They also, however, have characteristics that are distinct from talpids, such as maintenance of forefoot asymmetry and an increased emphasis of ray III.

Biological soil crusts: An organizing principle in dryland ecosystems (aka: the role of biocrusts in arid land hydrology)

USGS Publications Warehouse

Chamizo, Sonia; Belnap, Jayne; Elridge, David J; Issa, Oumarou M

2016-01-01

Biocrusts exert a strong influence on hydrological processes in drylands by modifying numerous soil properties that affect water retention and movement in soils. Yet, their role in these processes is not clearly understood due to the large number of factors that act simultaneously and can mask the biocrust effect. The influence of biocrusts on soil hydrology depends on biocrust intrinsic characteristics such as cover, composition, and external morphology, which differ greatly among climate regimes, but also on external factors as soil type, topography and vegetation distribution patterns, as well as interactions among these factors. This chapter reviews the most recent literature published on the role of biocrusts in infiltration and runoff, soil moisture, evaporation and non-rainfall water inputs (fog, dew, water absorption), in an attempt to elucidate the key factors that explain how biocrusts affect land hydrology. In addition to the crust type and site characteristics, recent studies point to the crucial importance of the type of rainfall and the spatial scale at which biocrust effects are analyzed to understand their role in hydrological processes. Future studies need to consider the temporal and spatial scale investigated to obtain more accurate generalizations on the role of biocrusts in land hydrology.

Description of the tadpoles of two endemic frogs: the Phu Luang cascade frog Odorrana aureola (Anura: Ranidae) and the Isan big-headed frog Limnonectes isanensis (Anura: Dicroglossidae) from northeastern Thailand.

PubMed

Ampai, Natee; Rujirawan, Attapol; Arkajag, Jirachai; Mcleod, David S; Aowphol, Anchalee

2015-07-07

We describe the external morphology of the tadpoles of two frogs endemic to Thailand: the Phu Luang cascade frog    (Odorrana aureola) and the Isan big-headed frog (Limnonectes isanensis) from the type localities in the Phu Luang Wildlife Sanctuary, Loei Province, northeastern Thailand. Morphological and genetic characters (16S rRNA) were used to identify specimen and match tadpoles to the adults. Detailed descriptions of external morphology and coloration in life are provided for both species. We provide a brief discussion of the ecology of these tadpoles and a comparison to previously published data from tadpoles of closely related taxa. Additionally, we provide evidence for the utility of larval morphology in resolving the taxonomic puzzles presented by cryptic species complexes.

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.

Ontogenetic changes in the internal and external morphology of the ilium in modern humans

PubMed Central

Abel, Richard; Macho, Gabriele A

2011-01-01

Trabecular architecture forms an important structural component of bone and, depending on the loading conditions encountered during life, is organised in a systematic, bone- and species-specific manner. However, recent studies suggested that gross trabecular arrangement (e.g. density distribution), like overall bone shape, is predetermined and/or affected by factors other than loading and perhaps less plastic than commonly assumed. To explore this issue further, the present cross-sectional ontogenetic study investigated morphological changes in external bone shape in relation to changes in trabecular bundle orientation and anisotropy. Radiographs of 73 modern human ilia were assessed using radiographic and Geometric Morphometric techniques. The study confirmed the apparently strong predetermination of trabecular bundle development, i.e. prior to external loading, although loading clearly also had an effect on overall morphology. For example, the sacro-pubic bundle, which follows the path of load transmission from the auricular surface to the acetabulum, is well defined and shows relatively high levels of anisotropy from early stages of development; the situation for the ischio-iliac strut is similar. However, while the sacro-pubic strut retains a constant relationship with the external landmarks defining the joint surfaces, the ischio-iliac bundle changes its relationship with the external landmarks and becomes aligned with the iliac tubercle only during late adolescence/early adulthood. It is tentatively proposed that the rearrangement of the ischio-iliac strut may reflect a change in locomotor pattern and/or a shift in positional behavior with increasing mass after growth of external bone dimensions has slowed/ceased. PMID:21323915

X-ray CT and histological imaging of xylem vessels organization in Mimosa pudica.

PubMed

Lee, Sang Joon; Song, Kahye; Kim, Hae Koo; Park, Joonghyuk

2013-11-01

Mimosa pudica has three distinct specialized organs, namely, pulvinus, secondary pulvinus, and pulvinule, which are respectively controlling the movements of petioles, leaflets, and pinna in response to external stimuli. Water flow is a key factor for such movements, but detailed studies on the organization of the vascular system for water transport in these organs have not been published yet. In this study, organizations of the xylem vessels and morphological features of the pulvinus, the secondary pulvinus, and the pulvinule were experimentally investigated by X-ray computed tomography and histological technique. Results showed that the xylem vessels were circularly distributed in the specialized motile organs and reorganized into distinct vascular bundles at the extremities. The number and the total cross-sectional area of the xylem vessels were increased inside the specialized motile organs. Morphological characteristics obtained in this study provided new insight to understand the functions of the vascular networks in the dynamic movements of M. pudica. Copyright © 2013 Wiley Periodicals, Inc.

Morphomechanics and Developmental Constraints in the Evolution of Ammonites Shell Form.

PubMed

Erlich, Alexander; Moulton, Derek E; Goriely, Alain; Chirat, Regis

2016-11-01

The idea that physical processes involved in biological development underlie morphogenetic rules and channel morphological evolution has been central to the rise of evolutionary developmental biology. Here, we explore this idea in the context of seashell morphogenesis. We show that a morphomechanical model predicts the effects of variations in shell shape on the ornamental pattern in ammonites, a now extinct group of cephalopods with external chambered shell. Our model shows that several seemingly unrelated characteristics of synchronous, ontogenetic, intraspecific, and evolutionary variations in ornamental patterns among various ammonite species may all be understood from the fact that the mechanical forces underlying the oscillatory behavior of the shell secreting system scale with the cross-sectional curvature of the shell aperture. This simple morphogenetic rule, emerging from biophysical interactions during shell formation, introduced a non-random component in the production of phenotypic variation and channeled the morphological evolution of ammonites over millions of years. As such, it provides a paradigm for the concept of "developmental constraints." © 2016 Wiley Periodicals, Inc.

Relating rock avalanche morphology to emplacement processes

NASA Astrophysics Data System (ADS)

Dufresne, Anja; Prager, Christoph; Bösmeier, Annette

2015-04-01

The morphology, structure and sedimentological characteristics of rock avalanche deposits reflect both internal emplacement processes and external influences, such as runout path characteristics. The latter is mainly predisposed by topography, substrate types, and hydrogeological conditions. Additionally, the geological setting at the source slope controls, e.g. the spatial distribution of accumulated lithologies and hence material property-related changes in morphology, or the maximum clast size and amount of fines of different lithological units. The Holocene Tschirgant rock avalanche (Tyrol, Austria) resulted from failure of an intensely deformed carbonate rock mass on the southeast face of a 2,370-m-high mountain ridge. The initially sliding rock mass rapidly fragmented as it moved towards the floor of the Inn River valley. Part of the 200-250 x 106 m3 (Patzelt 2012) rock avalanche debris collided with and moved around an opposing bedrock ridge and flowed into the Ötz valley, reaching up to 6.3 km from source. Where the Tschirgant rock avalanche spread freely it formed longitudinal ridges aligned along motion direction as well as smaller hummocks. Encountering high topography, it left runup ridges, fallback patterns (i.e. secondary collapse), and compressional morphology (successively elevated, transverse ridges). Further evidence for the mechanical landslide behaviour is given by large volumes of mobilized valley-fill sediments (polymict gravels and sands). These sediments indicate both shearing and compressional faulting within the rock avalanche mass (forming their own morphological units through, e.g. in situ bulldozing or as distinctly different hummocky terrain), but also indicate extension of the spreading landslide mass (i.e. intercalated/injected gravels encountered mainly in morphological depressions between hummocks). Further influences on its morphology are given by the different lithological units. E.g. the transition from massive dolomite/limestone sequences to weaker siliciclastic and evaporitic beds (sand-/siltstones, rauhwacken) can be pinpointed on LiDAR shaded relief images of the rock avalanche deposit. Hence, several morphological signatures are clearly related to differences in mechanical behaviour of the involved lithologies, whereas others reflect particular emplacement modes of the same rock unit: e.g. rockslide motion versus rock avalanche spreading. Reference Patzelt G. 2012. The rock avalanches of Tschirgant and Haiming (Upper Inn Valley, Tyrol, Austria), comment on the map supply. (German language only). Jahrbuch der Geologischen Bundesanstalt 152(1-4): 13-24.

TrOn: an anatomical ontology for the beetle Tribolium castaneum.

PubMed

Dönitz, Jürgen; Grossmann, Daniela; Schild, Inga; Schmitt-Engel, Christian; Bradler, Sven; Prpic, Nikola-Michael; Bucher, Gregor

2013-01-01

In a morphological ontology the expert's knowledge is represented in terms, which describe morphological structures and how these structures relate to each other. With the assistance of ontologies this expert knowledge is made processable by machines, through a formal and standardized representation of terms and their relations to each other. The red flour beetle Tribolium castaneum, a representative of the most species rich animal taxon on earth (the Coleoptera), is an emerging model organism for development, evolution, physiology, and pest control. In order to foster Tribolium research, we have initiated the Tribolium Ontology (TrOn), which describes the morphology of the red flour beetle. The content of this ontology comprises so far most external morphological structures as well as some internal ones. All modeled structures are consistently annotated for the developmental stages larva, pupa and adult. In TrOn all terms are grouped into three categories: Generic terms represent morphological structures, which are independent of a developmental stage. In contrast, downstream of such terms are concrete terms which stand for a dissectible structure of a beetle at a specific life stage. Finally, there are mixed terms describing structures that are only found at one developmental stage. These terms combine the characteristics of generic and concrete terms with features of both. These annotation principles take into account the changing morphology of the beetle during development and provide generic terms to be used in applications or for cross linking with other ontologies and data resources. We use the ontology for implementing an intuitive search function at the electronic iBeetle-Base, which stores morphological defects found in a genome wide RNA interference (RNAi) screen. The ontology is available for download at http://ibeetle-base.uni-goettingen.de.

A new species of Bruchidius (Coleoptera: Chrysomelidae: Bruchinae) from Albizia in Northern Thailand and a review of Bruchidius group 5.

PubMed

Tuda, Midori

2008-04-01

A new species, Bruchidius paicus (Insecta, Coleoptera) reared from the seeds of a leguminous tree, Albizia lebbeck (Fabaceae: Mimosoideae: Ingeae), is described from Northern Thailand. Inspection of genital and external morphological traits of B. paicus revealed that the new species belongs to Bruchidius Group 5 (sensu ). The definition of Group 5 is reviewed based on both external and genital morphology. Further comparison of the group to molecular Clade I of Bruchidius (sensu ) indicates the two groups correspond to each other.

Defining Morphology: Hands and Feet

PubMed Central

Biesecker, Leslie G.; Aase, Jon M.; Clericuzio, Carol; Gurrieri, Fiorella; Temple, I. Karen; Toriello, Helga

2009-01-01

An international group of clinicians working in the field of Dysmorphology has initiated the (re-) definition of all terms used to describe the external human phenotype. The goal is that through standardization of all terms and consensus regarding their definitions the reliability of description of features in humans will increase, comparisons of findings between patients will become more reliable, and discussions with other workers in the field such as developmental biologists and molecular geneticists will become more accurate. Here we report on the (re-) definition of terms needed to describe the major characteristics of the hands and feet. We provide a limited description of the anatomy of this region, limited background anthropometry, and an illustrated list of definitions. PMID:19125433

External built residential environment characteristics that affect mental health of adults.

PubMed

Ochodo, Charles; Ndetei, D M; Moturi, W N; Otieno, J O

2014-10-01

External built residential environment characteristics include aspects of building design such as types of walls, doors and windows, green spaces, density of houses per unit area, and waste disposal facilities. Neighborhoods that are characterized by poor quality external built environment can contribute to psychosocial stress and increase the likelihood of mental health disorders. This study investigated the relationship between characteristics of external built residential environment and mental health disorders in selected residences of Nakuru Municipality, Kenya. External built residential environment characteristics were investigated for 544 residents living in different residential areas that were categorized by their socioeconomic status. Medically validated interview schedules were used to determine mental health of residents in the respective neighborhoods. The relationship between characteristics of the external built residential environment and mental health of residents was determined by multivariable logistic regression analyses and chi-square tests. The results show that walling materials used on buildings, density of dwelling units, state of street lighting, types of doors, states of roofs, and states of windows are some built external residential environment characteristics that affect mental health of adult males and females. Urban residential areas that are characterized by poor quality external built environment substantially expose the population to daily stressors and inconveniences that increase the likelihood of developing mental health disorders.

Infrared image enhancement based on the edge detection and mathematical morphology

NASA Astrophysics Data System (ADS)

Zhang, Linlin; Zhao, Yuejin; Dong, Liquan; Liu, Xiaohua; Yu, Xiaomei; Hui, Mei; Chu, Xuhong; Gong, Cheng

2010-11-01

The development of the un-cooled infrared imaging technology from military necessity. At present, It is widely applied in industrial, medicine, scientific and technological research and so on. The infrared radiation temperature distribution of the measured object's surface can be observed visually. The collection of infrared images from our laboratory has following characteristics: Strong spatial correlation, Low contrast , Poor visual effect; Without color or shadows because of gray image , and has low resolution; Low definition compare to the visible light image; Many kinds of noise are brought by the random disturbances of the external environment. Digital image processing are widely applied in many areas, it can now be studied up close and in detail in many research field. It has become one kind of important means of the human visual continuation. Traditional methods for image enhancement cannot capture the geometric information of images and tend to amplify noise. In order to remove noise and improve visual effect. Meanwhile, To overcome the above enhancement issues. The mathematical model of FPA unit was constructed based on matrix transformation theory. According to characteristics of FPA, Image enhancement algorithm which combined with mathematical morphology and edge detection are established. First of all, Image profile is obtained by using the edge detection combine with mathematical morphological operators. And then, through filling the template profile by original image to get the ideal background image, The image noise can be removed on the base of the above method. The experiments show that utilizing the proposed algorithm can enhance image detail and the signal to noise ratio.

The adder (Vipera berus) in Southern Altay Mountains: population characteristics, distribution, morphology and phylogenetic position

PubMed Central

Cui, Shaopeng; Luo, Xiao; Chen, Daiqiang; Sun, Jizhou; Chu, Hongjun

2016-01-01

As the most widely distributed snake in Eurasia, the adder (Vipera berus) has been extensively investigated in Europe but poorly understood in Asia. The Southern Altay Mountains represent the adder’s southern distribution limit in Central Asia, whereas its population status has never been assessed. We conducted, for the first time, field surveys for the adder at two areas of Southern Altay Mountains using a combination of line transects and random searches. We also described the morphological characteristics of the collected specimens and conducted analyses of external morphology and molecular phylogeny. The results showed that the adder distributed in both survey sites and we recorded a total of 34 sightings. In Kanas river valley, the estimated encounter rate over a total of 137 km transects was 0.15 ± 0.05 sightings/km. The occurrence of melanism was only 17%. The small size was typical for the adders in Southern Altay Mountains in contrast to other geographic populations of the nominate subspecies. A phylogenetic tree obtained by Bayesian Inference based on DNA sequences of the mitochondrial cytochrome b (1,023 bp) grouped them within the Northern clade of the species but failed to separate them from the subspecies V. b. sachalinensis. Our discovery extends the distribution range of V. berus and provides a basis for further researches. We discuss the hypothesis that the adder expands its distribution border to the southwest along the mountains’ elevation gradient, but the population abundance declines gradually due to a drying climate. PMID:27602300

Species delimitation in frogs from South American temperate forests: The case of Eupsophus, a taxonomically complex genus with high phenotypic variation

PubMed Central

Correa, Claudio; Vásquez, Dayana; Castro-Carrasco, Camila; Zúñiga-Reinoso, Álvaro; Ortiz, Juan Carlos; Palma, R. Eduardo

2017-01-01

One of the most characteristic and abundant amphibian taxa of South American temperate forests is Eupsophus. The ten currently recognized species of the genus have been divided in two species groups, roseus and vertebralis, but most of them, eight, belong to the roseus group. Recent phylogeographic and phylogenetic studies have suggested that species diversity of the roseus group could be underestimated. An examination of the literature shows that species of the roseus group exhibit high levels of variation in their external characteristics, particularly those used as diagnostic characters, which compromises their taxonomy and hinders their field recognition. High levels of variation were also observed in several new populations of the roseus group discovered in southern Chile (36°-40°S), which could not be identified to the species level by their external characteristics. On the other hand, the literature reveals a scarse karyotype differentiation and a high bioacoustic uniformity among the species of the roseus group. We performed a Bayesian phylogenetic analysis using mitochondrial and nuclear genes to reevaluate the species diversity of the roseus group, including all the nominal species of Eupsophus and new populations. This analysis was complemented with three species delimitation approaches, General Mixed Yule Coalescent, multi-rate Poisson Tree Process and Automatic Barcode Gap Discovery. We favored a conservative delimitation of only four species for the roseus group, a result more consistent with the distribution of pairwise genetic distances, and the available chromosome and bioacoustic evidence. The four recognized lineages, which have nearly completely allopatric distributions, are named after the earliest nominal species that they include, but because high levels of phenotypic variation, they are not diagnosable by consistent differences in external morphology. We discuss the implications of this new proposal for the taxonomy and conservation of the genus, and the possible causes of the difficulty to estimate its species diversity. PMID:28809924

The use of breast ultrasound color Doppler vascular pattern morphology improves diagnostic sensitivity with minimal change in specificity.

PubMed

Svensson, W E; Pandian, A J; Hashimoto, H

2010-10-01

The aim of this study was to evaluate the use of vascular morphology, around and within the B-mode region of abnormality, for improving the diagnostic accuracy of two of the most common solid breast pathologies. The B-mode and Doppler images of 117 breast cancers and 366 fibroadenomas and lesions with a fibroadenoma-like appearance were reviewed retrospectively and the morphology of the vascular pattern was evaluated. The ratio of external to internal color Doppler, the external vascular pattern and the connecting vessels to internal vessels were assessed and differentiated into benign and malignant vascular patterns. These patterns were correlated with the histological diagnosis. Vascularity was demonstrated in 95 % of cancers and in 46 % of benign lesions with a trend to increasing vascularity in cancers. This provided poor specificity for excluding cancer in fibroadenomas. Variations in vascular pattern were recorded. The observed benign vascular patterns were avascularity, vascularity in the periphery and peripheral marginal vessels connecting with internal vascularity. The observed malignant vascular patterns were radially aligned external vessels with internal vessels being more numerous than external vessels which connected to radial vessels. (Fisher exact test p < 0.0001). Analysis of the vascular morphology improved the sensitivity for identifying cancers from 97 % (B-mode) to 99 % (B-mode and color Doppler) with a minimal reduction in specificity (93.7 to 92.6 %) or accuracy (94.6 to 94.2 %). The presence of vascularity within a lesion, by itself, is no longer a good predictor of malignancy because of the increase in Doppler sensitivity associated with improvements in ultrasound technology. The color Doppler ultrasound vascular pattern morphology improves the accuracy and sensitivity of B-mode image diagnosis, breast cancers and fibroadenomas with a minimal loss of specificity. Any breast lesion with radial rather than marginal connecting vessels should be regarded with suspicion. © Georg Thieme Verlag KG Stuttgart · New York.

Hip morphology predicts posterior hip impingement in a cadaveric model.

PubMed

Morris, William Z; Fowers, Cody A; Weinberg, Douglas S; Millis, Michael B; Tu, Leigh-Anne; Liu, Raymond W

2018-05-01

Posterior hip impingement is a recently-identified cause of hip pain. The purpose of this study is to characterise posterior femoroacetabular and ischiofemoral impingement and identify its predisposing morphologic traits. Two hundred and six cadaveric hips were randomly selected and taken through controlled motion in two pure axes associated with posterior hip impingement: external rotation (through the mechanical axis) and adduction (coronal plane). The range of motion and location of impingement was noted for each specimen. Morphologic traits including femoral/acetabular version, and true neck-shaft angle (TNSA) were also measured. External rotation impingement occurred between the femoral neck and acetabulum in 83.0% of hips, and between the lesser trochanter and ischial tuberosity in 17.0%. Adduction impingement occurred between the lesser trochanter and ischial tuberosity in 78.6% of hips, and between the femoral neck and acetabulum in 21.4%. Multiple regression revealed that increased femoral/acetabular version predicted earlier external rotation and adduction impingement. Unstandardised betas ranging from -0.39 to -0.64 reflect that each degree of increased femoral/acetabular version individually accounts for a loss of external rotation or adduction of approximately half a degree before impingement ( p < 0.001 for each). Increased TNSA was associated with earlier adduction impingement only (unstandardised beta -0.35, p = 0.005). Relative femoral/acetabular anteversion was associated with earlier posterior hip impingement. Coxa valga was associated with earlier adduction impingement, but protective against external rotation impingement. These findings highlight the importance of monitoring correction during femoral/acetabular osteotomies, as overcorrection of retroversion may predispose to earlier posterior impingement.

Controls on hillslope stability in a mountain river catchment

NASA Astrophysics Data System (ADS)

Golly, Antonius; Turowski, Jens; Hovius, Niels; Badoux, Alexandre

2015-04-01

Sediment transport in fluvial systems accounts for a large fraction of natural hazard damage costs in mountainous regions and is an important factor for risk mitigation, engineering and ecology. Although sediment transport in high-gradient channels gathered research interest over the last decades, sediment dynamics in steep streams are generally not well understood. For instance, the sourcing of the sediment and when and how it is actually mobilized is largely undescribed. In the Erlenbach, a mountain torrent in the Swiss Prealps, we study the mechanistic relations between in-channel hydrology, channel morphology, external climatic controls and the surrounding sediment sources to identify relevant process domains for sediment input and their characteristic scales. Here, we analyze the motion of a slow-moving landslide complex that was permanently monitored by time-lapse cameras over a period of 70 days at a 30 minutes interval. In addition, data sets for stream discharge, air temperature and precipitation rates are available. Apparent changes in the channel morphology, e.g. the destruction of channel-spanning bed forms, were manually determined from the time-lapse images and were treated as event marks in the time series. We identify five relevant types of sediment displacement processes emerging during the hillslope motion: concentrated mud flows, deep seated hillslope failure, catastrophic cavity failure, hillslope bank erosion and individual grain loss. Generally, sediment displacement occurs on a large range of temporal and spatial scales and sediment dynamics in steep streams not only depend on large floods with long recurrence intervals. We find that each type of displacement acts in a specific temporal and spatial domain with their characteristic scales. Different external climatic forcing (e.g. high-intensity vs. long-lasting precipitation events) promote different displacement processes. Stream morphology and the presence of boulders have a large effect on sediment input through deep seated failures and cavity failures while they have only minor impact on the other process types. In addition to large floods, which are generally recognized to produce huge amounts of sediment, we identify two relevant climatic regimes that play an important role for the sediment dynamics: a) long-lasting but low-intensity rainfall that explicitly trigger specific sediment displacement processes on the hillslopes and b) smaller discharge events with recurrence intervals of approximately one year that mobilize sediments from the hillslope's toes along the channel.

Pruning the Pearlsides: Reconciling morphology and molecules in mesopelagic fishes (Maurolicus: Sternoptychidae)

NASA Astrophysics Data System (ADS)

Rees, D. J.; Byrkjedal, I.; Sutton, T. T.

2017-03-01

The genus Maurolicus comprises extremely abundant vertically-migrating fishes that have considerable biomass in a number of regions worldwide. The genus was generally considered monotypic, with a single species, M. muelleri (Gmelin, 1789), inhabiting all world oceans. Based on differences in combinations of a limited number of morphometric characters, 15 separate species have been proposed, mostly associated with different ocean basins and seamounts. However, due to similarities in external morphology and overlap in ranges of morphometric characteristics, there remains a need for further validation of these species. Here, we present results of a multi-gene analysis, together with morphological data, for five putative Maurolicus species from multiple locations in the northern and southern hemispheres. Sampling encompasses described species from the North and South Atlantic, Mediterranean Sea, south-east Indian Ocean and the western South Pacific. Mitochondrial (16S and COI) and nuclear (ITS-2) gene sequences for 120 specimens were used in Maximum Parsimony and Bayesian Inference analyses as well as creation of haplotype networks. Morphological character analyses were based on data from 279 adult individuals. Several clear groupings emerge, conflicting with previously recognised species: (1) a 'northern' clade comprising Maurolicus muelleri and M. amethystinopunctatus, (2) a 'southern' clade comprising M. australis, M. walvisensis (also M. japonicus) and (3) eastern Equatorial and western North Atlantic M. weitzmani. The southern clade taxa are genetically indistinguishable and not well defined morphologically and present a clear case for synonymisation as M. australis. Synonymisation is also proposed for M. muelleri and M. amethystinopunctatus, with limited morphological variation likely to reflect physical and biological differences experienced north / south of the sub-polar front. Maurolicus weitzmani is clearly differentiated from all other Maurolicus species on both a molecular and morphological basis. Studies of genetic and morphological diversity in Maurolicus will further contribute to the question of 'what constitutes a species in the open ocean?', where a complex picture is emerging of both unexpected variation, as well as the unexpectantly absent genetic variation, in cosmopolitan taxa.

Virtual forensic entomology: improving estimates of minimum post-mortem interval with 3D micro-computed tomography.

PubMed

Richards, Cameron S; Simonsen, Thomas J; Abel, Richard L; Hall, Martin J R; Schwyn, Daniel A; Wicklein, Martina

2012-07-10

We demonstrate how micro-computed tomography (micro-CT) can be a powerful tool for describing internal and external morphological changes in Calliphora vicina (Diptera: Calliphoridae) during metamorphosis. Pupae were sampled during the 1st, 2nd, 3rd and 4th quarter of development after the onset of pupariation at 23 °C, and placed directly into 80% ethanol for preservation. In order to find the optimal contrast, four batches of pupae were treated differently: batch one was stained in 0.5M aqueous iodine for 1 day; two for 7 days; three was tagged with a radiopaque dye; four was left unstained (control). Pupae stained for 7d in iodine resulted in the best contrast micro-CT scans. The scans were of sufficiently high spatial resolution (17.2 μm) to visualise the internal morphology of developing pharate adults at all four ages. A combination of external and internal morphological characters was shown to have the potential to estimate the age of blowfly pupae with a higher degree of accuracy and precision than using external morphological characters alone. Age specific developmental characters are described. The technique could be used as a measure to estimate a minimum post-mortem interval in cases of suspicious death where pupae are the oldest stages of insect evidence collected. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

Comparative Physiological Studies of the Yeast and Mycelial Forms of Histoplasma capsulatum: Uptake and Incorporation of l-Leucine

PubMed Central

Gupta, Rishab K.; Howard, Dexter H.

1971-01-01

l-Leucine entered the cells of both morphological forms of Histoplasma capsulatum by a permease-like system at low external concentrations of substrate. However, at levels greater than 5 × 10−5m l-leucine, the amino acid entered the cells both through a simple diffusion-like process and the permease-like system. The rate of the amino acid diffusion into yeast and mycelial forms appeared to be the same, whereas the initial rate of accumulation through the permease-like system was 5 to 10 times faster in the mycelial phase than it was in the yeast phase. The Michaelis constants were 2.2 × 10−5m in yeast phase and 2 × 10−5m in mycelial phase cells. Transport of l-leucine at an external concentration of 10−5m showed all of the characteristics of a system of active transport, which was dependent on temperature and pH. Displacement or removal of the α-amino group, or modification of the α-carboxyl group abolished amino acid uptake. The process was competitively inhibited by neutral aliphatic side-chain amino acids (inhibition constants ranged from 1.5 × 10−5 to 6.2 × 10−5m). Neutral aromatic side-chain amino acids and the d-isomers of leucine and valine did not inhibit l-leucine uptake. These data were interpreted to mean that the l-leucine transport system is stereospecific and is highly specific for neutral aliphatic side-chain amino acids. Incorporation of l-leucine into macromolecules occurred at almost the same rate in both morphological forms of the fungus. The mycelial phase but not the yeast phase showed a slight initial lag in incorporation. In both morphological forms the intracellular pool of l-leucine was of limited capacity, and the total uptake of the amino acid was a function of intracellular pool size. The initial rate of l-leucine uptake was independent of the level of intracellular pool. Both morphological forms deaminated and degraded only a minor fraction of the accumulated leucine. PMID:4323295

External morphology and calling song characteristics in Tibicen plebejus (Hemiptera: Cicadidae).

PubMed

Mehdipour, Maedeh; Sendi, Jalal Jalali; Zamanian, Hossein

2015-02-01

Tibicen plebejus is the largest cicada native to the ecosystem in northern Iran. The male cicada produces a loud calling song for attracting females from a long distance. It is presumed that the female selects a mate based on a combination of passive and active mechanisms, but it is not known if she selects for size, nor if the male's size correlates with any characteristic of the advertisement call. In this study, we report the relationship between calling song features and morphological characters in the male of T. plebejus. Research was conducted in northern Iran during the summer of 2010. Seventeen males were collected and their calling songs were recorded in a natural environment. Two morphological characters were measured: length and weight. Maximum, minimum and average of values of 10 key acoustic variables of the calling song were analyzed: phrase duration, phrase part 1, phrase part 2, number of phrases per minute, echeme duration, echeme period, interecheme interval, number of echeme per second, echeme/intereheme ratio, and dominant frequency. The data were tested for the level of association between morphology and acoustic variables using simple linear regression. In conclusion, in terms of song structure, three significant positive correlations existed between length and (1) mean echeme duration, (2) mean echeme/interecheme ratio, (3) maximum echeme/interecheme ratio. We found out also four significant negative correlations between both length and weight with (1) minimum interecheme intervals, (2) mean dominant frequency, (3) minimum dominant frequency, (4) maximum dominant frequency, and between weight and (1) minimum interecheme intervals, (2) mean dominant frequency, (3) minimum dominant frequency, (4) maximum dominant frequency. It can be found that larger males of T. plebejus produce songs of lower frequency and are less silent between echemes. Copyright © 2014 Académie des sciences. Published by Elsevier SAS. All rights reserved.

Multiscale Characterization of Bacterial Swarming Illuminates Principles Governing Directed Surface Motility

NASA Astrophysics Data System (ADS)

Strickland, Ben; Hoeger, Kentaro; Ursell, Tristan

In many systems, individual characteristics interact, leading to the spontaneous emergence of order and complexity. In biological settings like microbes, such collective behaviors can imbue a variety of benefits to constituent individuals, including increased spatial range, improved access to nutrients, and enhanced resistance to antibiotic threats. To untangle the biophysical underpinnings of collective motility, we use passive tracers and a curated genetic library of Bacillus subtilis, including motile, non-motile, biofilm-deficient, and non-chemotactic mutants. We characterize and connect individual behavior on the microscopic scale to macroscopic colony morphology and motility of dendritic swarming. We analyze the persistence and dynamics of coordinated movement on length scales up to 4 orders of magnitude larger than that of individual cells, revealing rapid and directed responses of microbial groups to external stimuli, such as avoidance dynamics across chemical gradients. Our observations uncover the biophysical interplay between individual motility, surface wetness, phenotypic diversity, and external physical forces that robustly precipitate coordinated group behavior in microbes, and suggest general principles that govern the transition from individual to group behavior.

A new species of triadal coral snake of the genus Micrurus Wagler, 1824 (Serpentes: Elapidae) from northeastern Brazil.

PubMed

Pires, Matheus Godoy; Da Silva, Nelson Jorge; Feitosa, Darlan Tavares; Prudente, Ana Lúcia Da Costa; Filho, Gentil Alves Pereira; Zaher, Hussam

2014-06-05

The genus Micrurus comprises 123 currently recognized taxa (species and subspecies) that are traditionally arranged in four species groups diagnosable mainly by color pattern characteristics. Here, we describe a new species of triadal coral snake from northeastern Brazil. The new species is distinguished from other sympatric triadal congeners (M. lemniscatus carvalhoi, M. ibiboboca and M. brasiliensis) mainly by the entirely black parietals and by a suite of external characters and hemipenial morphology. The new species appears to be restricted to tropical ombrophilous lowland coastal forests of northeastern Brazil and all recently collected specimens are known to occur in small forest patches surrounded by periurban environment, which calls for an urgent evaluation on its conservation status.

Hydrothermal fabrication of octahedral-shaped Fe{sub 3}O{sub 4} nanoparticles and their magnetorheological response

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

Jung, H. S.; Choi, H. J., E-mail: hjchoi@inha.ac.kr

2015-05-07

Octahedral-shaped Fe{sub 3}O{sub 4} nanoparticles were synthesized in the presence of 1,3-diaminopropane using a hydrothermal method and assessed as a potential magnetorheological (MR) material. Their morphology, crystal structure, and magnetic properties were examined by scanning electron microscopy, transmission electron microscopy, X-ray diffraction, and vibrating sample magnetometry, respectively. The MR characteristics of the octahedral-shaped, Fe{sub 3}O{sub 4} nanoparticle-based MR particles when dispersed in silicone oil with a 10 vol. % particle concentration were examined using a rotational rheometer under an external magnetic field. The resulting MR fluids exhibited a Bingham-like behavior with a distinctive yield stress from their flow curves.

First Record of Bourgelatia diducta (Nematoda: Chabertiidae) from Wild Boars in the Republic of Korea

PubMed Central

Ahn, Kyu-Sung; Oh, Dae-Sung; Ahn, Ah-Jin; Suh, Guk-Hyun

2013-01-01

This study describes the first record of Bourgelatia diducta (Nematoda: Chabertiidae) from wild boars in the Republic of Korea (=South Korea). Gastrointestinal tracts of 87 Korean wild boars (Sus scrofa coreanus) hunted in mountains in the south-western part of South Korea between 2009 and 2012 were examined for their visceral helminths. B. diducta, as identified by morphological characteristics of the head and tail, were recovered from the large intestine of 47 (54%) wild boars. The average length of adult female worms was 11.3±0.87 mm and the thickest part of the body measured 0.54±0.04 mm in maximum width, while those of males were 9.8±0.72 and 0.45±0.03 mm, respectively. The characteristic J-shaped type II ovejector was observed in females, and the type II dorsal ray with 2 rami on each side of the median fissure was uniquely seen in males. The buccal capsule was small, relatively thin-walled, cylindrical, very short, and ring-shaped. The externodorsal ray arose from a common stem with the dorsal ray. The cervical groove was absent. The anterior extremity was equipped with 20-22 external corona radiata, 4 cephalic papillae and 2 lateral amphids around the mouth. The eggs were 66.0×38.9 µm in average size. By the present study, B. diducta (Nematoda: Chabertiidae) is recorded for the first time in South Korea. Additionally, morphological characteristics and identification keys provided in the present study will be helpful in the faunistic or taxonomic studies for strongylid nematodes related. PMID:24039287

First record of Bourgelatia diducta (Nematoda: Chabertiidae) from wild boars in the Republic of Korea.

PubMed

Ahn, Kyu-Sung; Oh, Dae-Sung; Ahn, Ah-Jin; Suh, Guk-Hyun; Shin, Sung-Shik

2013-08-01

This study describes the first record of Bourgelatia diducta (Nematoda: Chabertiidae) from wild boars in the Republic of Korea (=South Korea). Gastrointestinal tracts of 87 Korean wild boars (Sus scrofa coreanus) hunted in mountains in the south-western part of South Korea between 2009 and 2012 were examined for their visceral helminths. B. diducta, as identified by morphological characteristics of the head and tail, were recovered from the large intestine of 47 (54%) wild boars. The average length of adult female worms was 11.3±0.87 mm and the thickest part of the body measured 0.54±0.04 mm in maximum width, while those of males were 9.8±0.72 and 0.45±0.03 mm, respectively. The characteristic J-shaped type II ovejector was observed in females, and the type II dorsal ray with 2 rami on each side of the median fissure was uniquely seen in males. The buccal capsule was small, relatively thin-walled, cylindrical, very short, and ring-shaped. The externodorsal ray arose from a common stem with the dorsal ray. The cervical groove was absent. The anterior extremity was equipped with 20-22 external corona radiata, 4 cephalic papillae and 2 lateral amphids around the mouth. The eggs were 66.0×38.9 µm in average size. By the present study, B. diducta (Nematoda: Chabertiidae) is recorded for the first time in South Korea. Additionally, morphological characteristics and identification keys provided in the present study will be helpful in the faunistic or taxonomic studies for strongylid nematodes related.

Description of the larva of Mitosynum vockerothi Campbell, 1982, with remarks on the adult male genital morphology (Coleoptera, Staphylinidae, Oxytelinae).

PubMed

Makranczy, György; Webster, Reginald P

2016-01-01

The previously unknown larva of Mitosynum vockerothi Campbell, 1982, is described and illustrated. Adult male terminalia and genitalia are illustrated with line drawings. Adults of this species exhibit little difference in size or external morphology between males and females.

Morphological characterization of the antennal sensilla of the dogwood borer (Lepidoptera: Sesiidae)

USDA-ARS?s Scientific Manuscript database

The external morphology of the dogwood borer antennae and their sensilla was investigated using light and scanning electron microscopy. Male and female antennaes were clavate before tapering to an apical point and consisted of three main segments; the scape, pedicel, and flagellum. Although, there...

Morphological Variations and Biometrics of Ear: An Aid to Personal Identification.

PubMed

Verma, Pradhuman; Sandhu, Harpreet Kaur; Verma, Kanika Gupta; Goyal, Sharry; Sudan, Madhu; Ladgotra, Amit

2016-05-01

The morphological characteristics and dimensions of external ear vary in different human ethnic races which can be utilized in forensics for personal identification of living or deceased. To determine uniqueness of morphological and biometric variations of both ears for individualization among North East (NE) and North West (NW) subpopulation of India. The study was conducted on randomly selected 80 students, 40 from each subgroup. Nine ear parameters were recorded twice using digital Vernier's caliper by single investigator and two indices (Ear Index and Lobule Index) were calculated for both the ears. Morphological ear shapes and lobule attachment were also noted. Pearson's coefficient correlation test was performed on cross-tabulations to evaluate significant relationship between different variables. Of the total 35% free and 65% attached ear lobes were noted in both population groups. Oval ear shape was most commonly noted followed by triangular, rectangular and round in both populations. On comparing anthropometric measurements of ears in two populations it was found that except the tragus length and lobule index all other values were noted more in NW population. No statistical difference was found in ear and lobular indices of males and females although the left ear index and lobule index were found to be higher than right in both populations except in NW females where right lobule index was recorded more than left. The results obtained can be used in anthropological and forensic sciences for the inclusion and exclusion of persons for identification on the basis of ear variations.

Self-generated morphology in lagoon reefs

PubMed Central

Hamblin, Michael G.

2015-01-01

The three-dimensional form of a coral reef develops through interactions and feedbacks between its constituent organisms and their environment. Reef morphology therefore contains a potential wealth of ecological information, accessible if the relationships between morphology and ecology can be decoded. Traditionally, reef morphology has been attributed to external controls such as substrate topography or hydrodynamic influences. Little is known about inherent reef morphology in the absence of external control. Here we use reef growth simulations, based on observations in the cellular reefs of Western Australia’s Houtman Abrolhos Islands, to show that reef morphology is fundamentally determined by the mechanical behaviour of the reef-building organisms themselves—specifically their tendency to either remain in place or to collapse. Reef-building organisms that tend to remain in place, such as massive and encrusting corals or coralline algae, produce nodular reefs, whereas those that tend to collapse, such as branching Acropora, produce cellular reefs. The purest reef growth forms arise in sheltered lagoons dominated by a single type of reef builder, as in the branching Acropora-dominated lagoons of the Abrolhos. In these situations reef morphology can be considered a phenotype of the predominant reef building organism. The capacity to infer coral type from reef morphology can potentially be used to identify and map specific coral habitat in remotely sensed images. More generally, identifying ecological mechanisms underlying other examples of self-generated reef morphology can potentially improve our understanding of present-day reef ecology, because any ecological process capable of shaping a reef will almost invariably be an important process in real time on the living reef. PMID:26175962

Electrode erosion properties of gas spark switches for fast linear transformer drivers

NASA Astrophysics Data System (ADS)

Li, Xiaoang; Pei, Zhehao; Zhang, Yuzhao; Liu, Xuandong; Li, Yongdong; Zhang, Qiaogen

2017-12-01

Fast linear transformer drivers (FLTDs) are a popular and potential route for high-power devices employing multiple "bricks" in series and parallel, but they put extremely stringent demands on gas switches. Electrode erosion of FLTD gas switches is a restrictive and unavoidable factor that degrades performance and limits stability. In this paper, we systematically investigated the electrode erosion characteristics of a three-electrode field distortion gas switch under the typical working conditions of FLTD switches, and the discharge current was 7-46 kA with 46-300 ns rise time. A high speed frame camera and a spectrograph were used to capture the expansion process and the spectral emission of the spark channel was used to estimate the current density and the spark temperature, and then the energy fluxes and the external forces on the electrode surface were calculated. A tens of kilo-ampere nanosecond pulse could generate a 1011 W/m2 energy flux injection and 1.3-3.5 MPa external pressure on the electrode surface, resulting in a millimeter-sized erosion crater with the maximum peak height Rz reaching 100 μm magnitude. According to the morphological images by a laser scanning confocal microscope, the erosion crater of a FLTD switch contained three kinds of local morphologies, namely a center boiling region, an overflow region and a sputtering region. In addition, the crater size, the surface roughness, and the mass loss were highly dependent on the current amplitude and the transferred charge. We also observed Morphology Type I and Type II, respectively, with different pulse parameters, which had an obvious influence on surface roughness and mass loss. Finally, the quantitative relationship between the electrode mass loss and the pulse parameter was clarified. The transferred charge and the current amplitude were proved to be the main factors determining the electrode mass loss of a FLTD switch, and a least squares fitting expression for mass loss was also obtained.

Quantification of Dune Response over the Course of a 6-Day Nor'Easter, Outer Banks, NC

NASA Astrophysics Data System (ADS)

Brodie, K. L.; Spore, N.; Swann, C.

2014-12-01

The amount and type of foredune morphologic change during a storm event primarily scales with the level of inundation during that event. Specifically, external hydrodynamic forcing (total water level) can be compared with antecedent beach and foredune morphology to predict an impact regime that relates to the type of expected morphologic evolution of the system. For example, when total water levels are above the dune toe, but below the dune crest, the impact regime is classified as "collision" and the expected morphology response is slumping or scarping of the dune face. While the amount of dune retreat scales largely with the duration of wave attack to the dune face, characteristics of the dune other than its crest or toe elevation may also enhance or impede rates of morphologic change. The aftermath of Hurricane Sandy provided a unique opportunity to observe alongshore variations in dune response to a 6-day Nor'Easter (Hs >4 m in 6 m depth), as a variety of dunes were constructed (or not) by individual home owners in preparation for the winter storm season. Daily terrestrial lidar scans were conducted along 20 km of coastline in Duck, NC using Coastal Lidar And Radar Imaging System (CLARIS) during the first dune collision event following Sandy. Foredunes were grouped by their pre-storm form (e.g. vegetated, pushed, scarped, etc) using automated feature extraction tools based on surface curvature and slope, and daily rates of morphologic volume change were calculated. The highest dune retreat rates were focused along a 1.5 km region where cross-shore erosion of recently pushed, un-vegetated dunes reached 2 m/day. Variations in dune response were analyzed in relation to their pre-storm morphology, with care taken to normalize for alongshore variations in hydrodynamic forcing. Ongoing research is focused on identifying specific metrics that can be easily extracted from topographic DEMs to aid in dune retreat predictions.

Characterization of two non-native invasive bark beetles, Scolytus schevyrewi and Scolytus multistriatus (Coleoptera: Curculionidae: Scolytinae)

Treesearch

Patricia L. Johnson; Jane L. Hayes; John E. Rinehart; Walter S. Sheppard

2008-01-01

Scolytus schevyrewi Semenov, the banded elm bark beetle, and S. multistriatus Marsham, the smaller European elm bark beetle, are morphologically similar. Reliance on adult external morphological characters for identification can be problematic because of wide within species variability and the need for good-quality specimens....

New circumscription of freshwater fish parasites Monobothrium diesing, 1863 and Promonobothrium mackiewicz, 1968 (Cestoda: Caryophyllidea) using morphological and molecular evidence.

PubMed

Scholz, Tomáš; Oros, Mikuláš; Choudhury, Anindo; Brabec, Jan; Waeschenbach, Andrea

2015-02-01

Two genera of caryophyllidean cestodes, Monobothrium Diesing, 1863 and Promonobothrium Mackiewicz, 1968 , from cypriniform fishes (cyprinids and suckers) in the Holarctic Region, are revised using morphological and molecular evidence. Monobothrium, which includes morphologically distinct species that occur in European cyprinids (Cyprinidae) and North American suckers (Catostomidae), is separated into 3 genera. Monobothrium becomes monotypic and is represented by its type species, Monobothrium wageneri Nybelin, 1922 , which occurs in European tench, Tinca tinca (Cyprinidae). Monobothrium auriculatum Kulakovskaya, 1961 from Leuciscus danilevskii (Cyprinidae) in the Ukraine, is tentatively transferred to Caryophyllaeus Gmelin, 1790 as Caryophyllaeus auriculatus ( Kulakovskaya, 1961 ) n. comb. because it possesses morphological characteristics considered to be typical of Caryophyllaeus but which are absent in Monobothrium (shape of the scolex, presence of a seminal receptacle, short neck, and absence of a large, muscular papilla surrounding the large gonopores). The 5 remaining Monobothrium species from suckers in North America are transferred to Promonobothrium based on shared morphological features and molecular data. Species of Promonobothrium differ from M. wageneri by having an external seminal vesicle (absent in M. wageneri), the absence of postovarian vitelline follicles in North American species (present in M. wageneri), and a scolex that is digitiform papillate, loculopapillate, or loculotruncate, i.e., equipped with weak loculi and a terminal introvert (vs. claviform, bluntly ended, with 6 weak, shallow, longitudinal grooves in M. wageneri). Phylogenetic analysis of nuclear ribosomal RNA genes ssr- and lsrDNA placed Promonobothrium minytremi within a clade of 3 of the 5 North American Monobothrium species. The position of M. wageneri, although distinct from the remaining Monobothrium species, is unresolved within the Caryophyllidea. This study further supports the pattern that the biogeography of caryophyllidean taxa is generally constrained by host and continental association.

Generality of vertebrate developmental patterns: evidence for a dermomyotome in fish

PubMed Central

Devoto, S.H.

2012-01-01

Summary The somitic compartment that gives rise to trunk muscle and dermis in amniotes is an epithelial sheet on the external surface of the somite, and is known as the dermomyotome. However, despite its central role in the development of the trunk and limbs, the evolutionary history of the dermomyotome and its role in non-amniotes is poorly understood. We have tested whether a tissue with the morphological and molecular characteristics of a dermomyotome exists in non-amniotes. We show that representatives of the agnathans and of all major clades of gnathostomes each have a layer of cells on the surface of the somite, external to the embryonic myotome. These external cells do not show any signs of terminal myogenic or dermogenic differentiation. Moreover, in the embryos of bony fishes as diverse as sturgeons (Chondrostei) and zebrafish (Teleostei) this layer of cells expresses the pax 3 and 7 genes that mark myogenic precursors. Some of the pax7-expressing cells also express the differentiation-promoting myogenic regulatory factor Myogenin and appear to enter into the myotome. We therefore suggest that the dermomyotome is an ancient and conserved structure that evolved prior to the last common ancestor of all vertebrates. The identification of a dermomyotome in fish makes it possible to apply the powerful cellular and genetic approaches available in zebrafish to the understanding of this key developmental structure. PMID:16409387

Integrating a Numerical Taxonomic Method and Molecular Phylogeny for Species Delimitation of Melampsora Species (Melampsoraceae, Pucciniales) on Willows in China

PubMed Central

Zhao, Peng; Wang, Qing-Hong; Tian, Cheng-Ming; Kakishima, Makoto

2015-01-01

The species in genus Melampsora are the causal agents of leaf rust diseases on willows in natural habitats and plantations. However, the classification and recognition of species diversity are challenging because morphological characteristics are scant and morphological variation in Melampsora on willows has not been thoroughly evaluated. Thus, the taxonomy of Melampsora species on willows remains confused, especially in China where 31 species were reported based on either European or Japanese taxonomic systems. To clarify the species boundaries of Melampsora species on willows in China, we tested two approaches for species delimitation inferred from morphological and molecular variations. Morphological species boundaries were determined based on numerical taxonomic analyses of morphological characteristics in the uredinial and telial stages by cluster analysis and one-way analysis of variance. Phylogenetic species boundaries were delineated based on the generalized mixed Yule-coalescent (GMYC) model analysis of the sequences of the internal transcribed spacer (ITS1 and ITS2) regions including the 5.8S and D1/D2 regions of the large nuclear subunit of the ribosomal RNA gene. Numerical taxonomic analyses of 14 morphological characteristics recognized in the uredinial-telial stages revealed 22 morphological species, whereas the GMYC results recovered 29 phylogenetic species. In total, 17 morphological species were in concordance with the phylogenetic species and 5 morphological species were in concordance with 12 phylogenetic species. Both the morphological and molecular data supported 14 morphological characteristics, including 5 newly recognized characteristics and 9 traditionally emphasized characteristics, as effective for the differentiation of Melampsora species on willows in China. Based on the concordance and discordance of the two species delimitation approaches, we concluded that integrative taxonomy by using both morphological and molecular variations was an effective approach for delimitating Melampsora species on willows in China. PMID:26680416

Statistical analysis of sperm sorting

NASA Astrophysics Data System (ADS)

Koh, James; Marcos, Marcos

2017-11-01

The success rate of assisted reproduction depends on the proportion of morphologically normal sperm. It is possible to use an external field for manipulation and sorting. Depending on their morphology, the extent of response varies. Due to the wide distribution in sperm morphology even among individuals, the resulting distribution of kinematic behaviour, and consequently the feasibility of sorting, should be analysed statistically. In this theoretical work, Resistive Force Theory and Slender Body Theory will be applied and compared. Full name is Marcos.

Zircon crystal morphology and internal structures as a tool for constraining magma sources: Examples from northern Portugal Variscan biotite-rich granite plutons

NASA Astrophysics Data System (ADS)

Brites Martins, Helena C.; Simões, Pedro P.; Abreu, Joana

2014-09-01

In northern Portugal, large volumes of granitoids were emplaced during the last stage (D3) of the Variscan orogeny and display a wide range of petrological signatures. We studied the morphologies and internal structures of zircons from syn-, late- and post-D3 granitoids. The sin-D3 granitoids include the Ucanha-Vilar, Lamego, Felgueiras, Sameiro, and Refoios do Lima plutons, the late- and post-D3 granitoids are represented by the Vieira do Minho and the Vila Pouca de Aguiar plutons, respectively. Typological investigations after Pupin (1980) along with scanning electron microprobe imaging reveal that the external morphology of zircon changes consistently with a decrease in the crystallization temperature. Zircon populations from the Refoios do Lima and the Vieira do Minho granites show gradual changes in the internal morphologies and their typologic evolution trends are consistent with their mainly crustal origin. The Sameiro, Felgueiras, Lamego and Ucanha-Vilar granites have more complex internal and external morphology and typological evolution trends that cross the domain of the calc-alkaline to the aluminous granites compatible with a mixing process. Finally, the morphological types of the Vila Pouca de Aguiar granites are found both in calc-alkaline and sub-alkaline granites and their typological evolutionary trends follow the calc-alkaline/sub-alkaline trend, suggesting crustal sources with some mantle contribution.

A common terminology for the external anatomy of centipedes (Chilopoda)

PubMed Central

Bonato, Lucio; Edgecombe, Gregory D.; Lewis, John G.E.; Minelli, Alessandro; Pereira, Luis A.; Shelley, Rowland M.; Zapparoli, Marzio

2010-01-01

Abstract A common terminology for the external morphological characters of centipedes (Chilopoda) is proposed. Terms are selected from the alternatives used in the English literature, preferring those most frequently used or those that have been introduced explicitly. A total of 330 terms are defined and illustrated, and another ca. 500 alternatives are listed. PMID:21594038

Role of time-resolved-CTA in intracranial arteriovenous malformation evaluation at 128-slice CT in comparison with digital subtraction angiography.

PubMed

Singh, Rupinder; Gupta, Vivek; Ahuja, Chirag; Kumar, Ajay; Mukherjee, Kanchan K; Khandelwal, Niranjan

2018-06-01

Introduction The present study aimed to evaluate the accuracy of time-resolved-computed tomographic angiography (TR-CTA) on a 128-slice CT scanner vis-à-vis cerebral digital subtraction angiography (DSA) in defining the morphological and haemodynamic characteristics of cerebral arteriovenous malformation (AVM). Methods Twenty-one patients (age range 10-46, mean 24.8 years) with clinical suspicion of AVM and three patients (age range 23-35, mean 24.3 years) with diagnosed AVM who were on follow-up underwent DSA and TR-CTA, on average 1.5 days apart. Three independent neuroradiologists analysed both studies in a blinded fashion based on the following parameters: AVM location, arterial feeder territories, venous drainage pattern, nidus flow characteristics, venous outflow obstruction, arterial feeder enlargement, external carotid artery feeder, location of aneurysm if any, leptomeningeal and transdural recruitment, neoangiogenesis, and pseudophlebitic pattern. Results The TR-CTA correctly demonstrated AVM in all 21 positive cases. It concordantly detected location (21/21), venous drainage pattern (21/21), nidus flow characteristics (21/21), and the venous outflow obstruction (9/9). However, discordance was seen in the demonstration of the arterial feeder (2/45) ( p = 0.49), arterial enlargement (13/17) ( p = 0.103), external carotid artery feeder (0/1), aneurysmal location (3/5) ( p = 0.40), leptomeningeal recruitment (1/3) ( p = 0.40), neoangiogenesis (0/4) ( p = 0.028) and in the pseudophlebitic pattern (2/5) ( p = 0.167) demonstration. Conclusions The results suggest that TR-CTA can provide the important features of cerebral AVM which are required in patient management.

Developmental Changes in Morphology of the Middle and Posterior External Cranial Base in Modern Homo sapiens.

PubMed

Dalal, Deepal H; Smith, Heather F

2015-01-01

The basicranium has been described as phylogenetically informative, developmentally stable, and minimally affected by external factors and consequently plays an important role in cranial size and shape in subadult humans. Here basicranial variation of subadults from several modern human populations was investigated and the impact of genetic relatedness on basicranial morphological similarities was investigated. Three-dimensional landmark data were digitized from subadult basicrania from seven populations. Published molecular data on short tandem repeats were statistically compared to morphological data from three ontogenetic stages. Basicranial and temporal bone morphology both reflect genetic distances in childhood and adolescence (5-18 years), but not in infancy (<5 years). The occipital bone reflects genetic distances only in adolescence (13-18 years). The sphenoid bone does not reflect genetic distances at any ontogenetic stage but was the most diagnostic region evaluated, resulting in high rates of correct classification among populations. These results suggest that the ontogenetic processes driving basicranial development are complex and cannot be succinctly summarized across populations or basicranial regions. However, the fact that certain regions reflect genetic distances suggests that the morphology of these regions may be useful in reconstructing population history in specimens for which direct DNA evidence is unavailable, such as archaeological sites.

Neutrophils establish rapid and robust WAVE complex polarity in an actin-dependent fashion.

PubMed

Millius, Arthur; Dandekar, Sheel N; Houk, Andrew R; Weiner, Orion D

2009-02-10

Asymmetric intracellular signals enable cells to migrate in response to external cues. The multiprotein WAVE (also known as SCAR or WASF) complex activates the actin-nucleating Arp2/3 complex [1-4] and localizes to propagating "waves," which direct actin assembly during neutrophil migration [5, 6]. Here, we observe similar WAVE complex dynamics in other mammalian cells and analyze WAVE complex dynamics during establishment of neutrophil polarity. Earlier models proposed that spatially biased generation [7] or selection of protrusions [8] enables chemotaxis. These models require existing morphological polarity to control protrusions. We show that spatially biased generation and selection of WAVE complex recruitment also occur in morphologically unpolarized neutrophils during development of their first protrusions. Additionally, several mechanisms limit WAVE complex recruitment during polarization and movement: Intrinsic cues restrict WAVE complex distribution during establishment of polarity, and asymmetric intracellular signals constrain it in morphologically polarized cells. External gradients can overcome both intrinsic biases and control WAVE complex localization. After latrunculin-mediated inhibition of actin polymerization, addition and removal of agonist gradients globally recruits and releases the WAVE complex from the membrane. Under these conditions, the WAVE complex no longer polarizes, despite the presence of strong external gradients. Thus, actin polymer and the WAVE complex reciprocally interact during polarization.

Effect of external jet-flow deflector geometry on OTW aero-acoustic characteristics

NASA Technical Reports Server (NTRS)

Vonglahn, U.; Groesbeck, D.

1976-01-01

The effect of geometry variations in the design of external deflectors for use with over-the-wing (OTW) configurations was studied at model scale and subsonic jet velocities. Included in the variations were deflector size and angle as well as wing size and flap setting. A conical nozzle (5.2-cm diameter) mounted at 0.1 chord above and downstream of the wing leading edges was used. The data indicate that external deflectors provide satisfactory takeoff and approach aerodynamic performance and acoustic characteristics for OTW configurations. These characteristics together with expected good cruise aerodynamics, since external deflectors are storable, may provide optimum OTW design configurations.

Ultrastructural Comparison of Hepatozoon ixoxo and Hepatozoon theileri (Adeleorina: Hepatozoidae), Parasitising South African Anurans.

PubMed

Conradie, Roxanne; Cook, Courtney A; du Preez, Louis H; Jordaan, Anine; Netherlands, Edward C

2017-03-01

To date, only two haemogregarine parasite species have been described from South African anurans: Hepatozoon ixoxo, infecting toads of the genus Sclerophrys (syn. Amietophrynus); and Hepatozoon theileri, parasitising the common river frog, Amietia quecketti. Both species have been characterised using limited morphology, and molecular data from PCR amplified fragments of the 18S rRNA gene. However, no ultrastructural work has been performed thus far. The aim of this study was to add descriptive information on the two species by studying their ultrastructural morphology. Mature gamont stages, common in the peripheral blood of infected frogs, were examined by transmission electron microscopy. Results indicate that H. ixoxo and H. theileri share typical apicomplexan characteristics, but differ markedly in their external cellular structure. Hepatozoon ixoxo is an encapsulated parasite presenting a prominent cap at the truncate pole, and shows no visible modifications to the host cell membrane. In comparison, H. theileri does not present a capsule or cap, and produces marked morphological changes to its host cell. Scanning electron microscopy was performed to further examine the cytopathological effects of H. theileri, and results revealed small, knob-like protrusions on the erythrocyte surface, as well as notable distortion of the overall shape of the host cell. © 2016 The Author(s) Journal of Eukaryotic Microbiology © 2016 International Society of Protistologists.

Relative Position of the Third Characteristic Peak of the Intracranial Pressure Pulse Waveform Morphology Differentiates Normal-Pressure Hydrocephalus Shunt Responders and Nonresponders.

PubMed

Hamilton, Robert; Fuller, Jennifer; Baldwin, Kevin; Vespa, Paul; Hu, Xiao; Bergsneider, Marvin

2016-01-01

The diversion of cerebrospinal fluid (CSF) remains the principal treatment option for patients with normal-pressure hydrocephalus (NPH). External lumbar drain (ELD) and overnight intracranial pressure (ICP) monitoring are popular prognostic tests for differentiating which patients will benefit from shunting. Using the morphological clustering and analysis of continuous intracranial pulse (MOCAIP) algorithm to extract morphological metrics from the overnight ICP signal, we hypothesize that changes in the third peak of the ICP pulse pressure waveform can be used to differentiate ELD responders and nonresponders. Our study involved 66 patients (72.2 ± 9.8 years) undergoing evaluation for possible NPH, which included overnight ICP monitoring and ELD. ELD outcome was based on clinical notes and divided into nonresponders and responders. MOCAIP was used to extract mean ICP, ICP wave amplitude (waveAmp), and a metric derived to study P3 elevation (P3ratio). Of the 66 patients, 7 were classified as nonresponders and 25 as significant responders. The mean ICP and waveAmp did not vary significantly (p = 0.19 and p = 0.41) between the outcome groups; however, the P3ratio did show a significant difference (p = 0.04). Initial results suggest that the P3ratio might be used as a prognostic indicator for ELD outcome.

Influence of polarized bias and porous silicon morphology on the electrical behavior of Au-porous silicon contacts*

PubMed Central

Zhao, Yue; Li, Dong-sheng; Xing, Shou-xiang; Yang, De-ren; Jiang, Min-hua

2005-01-01

This paper reports the surface morphology and I-V curves of porous silicon (PS) samples and related devices. The observed fabrics on the PS surface were found to affect the electrical property of PS devices. When the devices were operated under different external bias (10 V or 3 V) for 10 min, their observed obvious differences in electrical properties may be due to the different control mechanisms in the Al/PS interface and PS matrix morphology. PMID:16252350

Pore-scale Evaluation of Immiscible Fluid Characteristics and Displacements: Comparison Between Ambient- and Supercritical-Condition Experimental Studies

NASA Astrophysics Data System (ADS)

Herring, A. L.; Wildenschild, D.; Andersson, L.; Harper, E.; Sheppard, A.

2015-12-01

The transport of immiscible fluids within porous media is a topic of great importance for a wide range of subsurface processes; e.g. oil recovery, geologic sequestration of CO2, gas-water mass transfer in the vadose zone, and remediation of non-aqueous phase liquids (NAPLs) from groundwater. In particular, the trapping and mobilization of nonwetting phase fluids (e.g. oil, CO2, gas, or NAPL in water-wet media) is of significant concern; and has been well documented to be a function of both wetting and nonwetting fluid properties, morphological characteristics of the porous medium, and system history. However, generalization of empirical trends and results for application between different fluid-fluid-medium systems requires careful consideration and characterization of the relevant system properties. We present a comprehensive and cohesive description of nonwetting phase behaviour as observed via a suite of three dimensional x-ray microtomography imaging experiments investigating immiscible fluid flow, trapping, and interfacial interactions of wetting (brine) and nonwetting (air, oil, and supercritical CO2) phase in sandstones and synthetic media. Microtomographic images, acquired for drainage and imbibition flow processes, allow for precise and extensive characterization of nonwetting phase fluid saturation, topology, and connectivity; imaging results are paired with externally measured capillary pressure data to provide a comprehensive description of fluid states. Fluid flow and nonwetting phase trapping behaviour is investigated as a function of system history, morphological metrics of the geologic media, and nonwetting phase fluid characteristics; and particular emphasis is devoted to the differences between ambient condition (air-brine) and reservoir condition (supercritical CO2-brine) studies. Preliminary results provide insight into the applicability of using ambient condition experiments to explore reservoir condition processes, and also elucidate the underlying physics of trapping and mobilization of nonwetting phase fluids.

Adaptive latitudinal variation in Common Blackbird Turdus merula nest characteristics

PubMed Central

Mainwaring, Mark C; Deeming, D Charles; Jones, Chris I; Hartley, Ian R

2014-01-01

Nest construction is taxonomically widespread, yet our understanding of adaptive intraspecific variation in nest design remains poor. Nest characteristics are expected to vary adaptively in response to predictable variation in spring temperatures over large spatial scales, yet such variation in nest design remains largely overlooked, particularly amongst open-cup-nesting birds. Here, we systematically examined the effects of latitudinal variation in spring temperatures and precipitation on the morphology, volume, composition, and insulatory properties of open-cup-nesting Common Blackbirds’ Turdus merula nests to test the hypothesis that birds living in cooler environments at more northerly latitudes would build better insulated nests than conspecifics living in warmer environments at more southerly latitudes. As spring temperatures increased with decreasing latitude, the external diameter of nests decreased. However, as nest wall thickness also decreased, there was no variation in the diameter of the internal nest cups. Only the mass of dry grasses within nests decreased with warmer temperatures at lower latitudes. The insulatory properties of nests declined with warmer temperatures at lower latitudes and nests containing greater amounts of dry grasses had higher insulatory properties. The insulatory properties of nests decreased with warmer temperatures at lower latitudes, via changes in morphology (wall thickness) and composition (dry grasses). Meanwhile, spring precipitation did not vary with latitude, and none of the nest characteristics varied with spring precipitation. This suggests that Common Blackbirds nesting at higher latitudes were building nests with thicker walls in order to counteract the cooler temperatures. We have provided evidence that the nest construction behavior of open-cup-nesting birds systematically varies in response to large-scale spatial variation in spring temperatures. PMID:24683466

Adaptive latitudinal variation in Common Blackbird Turdus merula nest characteristics.

PubMed

Mainwaring, Mark C; Deeming, D Charles; Jones, Chris I; Hartley, Ian R

2014-03-01

Nest construction is taxonomically widespread, yet our understanding of adaptive intraspecific variation in nest design remains poor. Nest characteristics are expected to vary adaptively in response to predictable variation in spring temperatures over large spatial scales, yet such variation in nest design remains largely overlooked, particularly amongst open-cup-nesting birds. Here, we systematically examined the effects of latitudinal variation in spring temperatures and precipitation on the morphology, volume, composition, and insulatory properties of open-cup-nesting Common Blackbirds' Turdus merula nests to test the hypothesis that birds living in cooler environments at more northerly latitudes would build better insulated nests than conspecifics living in warmer environments at more southerly latitudes. As spring temperatures increased with decreasing latitude, the external diameter of nests decreased. However, as nest wall thickness also decreased, there was no variation in the diameter of the internal nest cups. Only the mass of dry grasses within nests decreased with warmer temperatures at lower latitudes. The insulatory properties of nests declined with warmer temperatures at lower latitudes and nests containing greater amounts of dry grasses had higher insulatory properties. The insulatory properties of nests decreased with warmer temperatures at lower latitudes, via changes in morphology (wall thickness) and composition (dry grasses). Meanwhile, spring precipitation did not vary with latitude, and none of the nest characteristics varied with spring precipitation. This suggests that Common Blackbirds nesting at higher latitudes were building nests with thicker walls in order to counteract the cooler temperatures. We have provided evidence that the nest construction behavior of open-cup-nesting birds systematically varies in response to large-scale spatial variation in spring temperatures.

Stereo and scanning electron microscopy of in-shell Brazil nut (Bertholletia excelsa H.B.K.): part two-surface sound nut fungi spoilage susceptibility.

PubMed

Scussel, Vildes M; Manfio, Daniel; Savi, Geovana D; Moecke, Elisa H S

2014-11-01

This work reports the in-shell Brazil nut spoilage susceptible morpho-histological characteristics and fungi infection (shell, edible part, and brown skin) through stereo and scanning electron microscopies (SEM). The following characteristics related to shell (a) morphology-that allow fungi and insects' entrance to inner nut, and (b) histology-that allow humidity absorption, improving environment conditions for living organisms development, were identified. (a.1) locule in testae-the nut navel, which is a cavity formed during nut detaching from pods (located at 1.0 to 2.0/4th of the shell B&C nut faces linkage). It allows the nut brown skin (between shell and edible part) first contact to the external environment, through the (a.2) nut channel-the locule prolongation path, which has the water/nutrients cambium function for their transport and distribution to the inner seed (while still on the tree/pod). Both, locule followed by the channel, are the main natural entrance of living organisms (fungi and insects), including moisture to the inner seed structures. In addition, the (a.3) nut shell surface-which has a crinkled and uneven surface morphology-allows water absorption, thus adding to the deterioration processes too. The main shell histological characteristic, which also allows water absorption (thus improving environment conditions for fungi proliferation), is the (b.1) cell wall porosity-the multilayered wall and porous rich cells that compose the shell faces double tissue layers and the (b.2) soft tissue-the mix of tissues 2 faces corner/linkage. This work also shows in details the SEM nut spoilage susceptible features highly fungi infected with hyphae and reproductive structures distribution. © 2014 Institute of Food Technologists®

Regional stiffening with aging in tibialis anterior tendons of mice occurs independent of changes in collagen fibril morphology

PubMed Central

Wood, Lauren K.; Arruda, Ellen M.

2011-01-01

The incidence of tendon degeneration and rupture increases with advancing age. The mechanisms underlying this increased risk remain unknown but may arise because of age-related changes in tendon mechanical properties and structure. Our purpose was to determine the effect of aging on tendon mechanical properties and collagen fibril morphology. Regional mechanical properties and collagen fibril characteristics were determined along the length of tibialis anterior (TA) tendons from adult (8- to 12-mo-old) and old (28- to 30-mo-old) mice. Tangent modulus of all regions along the tendons increased in old age, but the increase was substantially greater in the proximal region adjacent to the muscle than in the rest of the tendon. Overall end-to-end modulus increased with old age at maximum tendon strain (799 ± 157 vs. 1,419 ± 91 MPa) and at physiologically relevant strain (377 ± 137 vs. 798 ± 104 MPa). Despite the dramatic changes in tendon mechanical properties from adulthood to old age, collagen fibril morphology and packing fraction remained relatively constant in all tendon regions examined. Since tendon properties are influenced by their external loading environment, we also examined the effect of aging on TA muscle contractile properties. Maximum isometric force did not differ between the age groups. We conclude that TA tendons stiffen in a region-dependent manner throughout the life span, but the changes in mechanical properties are not accompanied by corresponding changes in collagen fibril morphology or force-generating capacity of the TA muscle. PMID:21737825

Trajectories of Classroom Externalizing Behavior: Contributions of Child Characteristics, Family Characteristics, and the Teacher-Child Relationship during the School Transition

ERIC Educational Resources Information Center

Silver, R.B.; Measelle, J.R.; Armstrong, J.M.; Essex, M.J.

2005-01-01

The unique and interactive contributions of past externalizing behavior, negative parenting, and teacher-child relationship quality to externalizing behavior trajectories after the transition to school were examined. In a sample of 283 children, random regression analyses indicated that conflict in the teacher-child relationship during the school…

Embryonic staging and external features of development of the Chimaeroid fish, Callorhinchus milii (Holocephali, Callorhinchidae).

PubMed

Didier, Dominique A; LeClair, Elizabeth E; Vanbuskirk, Dana R

1998-04-01

The development of Callorhinchus milii, a primitive chondrichthyan fish (Subclass Holocephali) is described in detail based on a complete series of embryos from stage 17 to hatching. The external features of these specimens, in comparison with other chondrichthyan embryos, are used to establish the first staging table for any chimaeroid species. Each stage of C. milii is defined by a suite of morphological characters in addition to total length, including the number of somites, extent of external pigmentation, eye size and shape, head flexure, heart morphology, and size and shape of paired and unpaired fins. Particular attention is given to features of the gill arches and associated structures, including external gill filaments and the opercular flap. Embryos of this species also possess a transient rostral bulb, a feature unique to chimaeroids. Embryological development of Callorhinchus milii is similar to that previously described for sharks and batoids (Subclass Elasmobranchii), including the spiny dogfish, Squalus acanthias, the Japanese bullshark, Heterodontus japonicus, the lesser spotted dogfish, Scyliorhinus canicula, the frill shark, Chlamydoselachus anguineus, the guitarfish, Rhinobatus halavi, and the skate, Raja brachyura. Callorhinchus milii is also similar in overall development to another holocephalan, Hydrolagus colliei. A review of previous staging schemes confirms that early morphological development in all three major chondrichthyan lineages (sharks, batoids, and chimaeras) can be correlated using a common set of stages. A uniform staging system is provided that should prove useful in continuing ontogenetic and phylogenetic studies of this entire clade of fishes. J. Morphol. 236:25-47, 1998. © 1998 Wiley-Liss, Inc. Copyright © 1998 Wiley-Liss, Inc.

Discrimination of Mediterranean mussel (Mytilus galloprovincialis) feces in deposited materials by fecal morphology.

PubMed

Akiyama, Yoshihiro B; Iseri, Erina; Kataoka, Tomoya; Tanaka, Makiko; Katsukoshi, Kiyonori; Moki, Hirotada; Naito, Ryoji; Hem, Ramrav; Okada, Tomonari

2017-02-15

In the present study, we determined the common morphological characteristics of the feces of Mytilus galloprovincialis to develop a method for visually discriminating the feces of this mussel in deposited materials. This method can be used to assess the effect of mussel feces on benthic environments. The accuracy of visual morphology-based discrimination of mussel feces in deposited materials was confirmed by DNA analysis. Eighty-nine percent of mussel feces shared five common morphological characteristics. Of the 372 animal species investigated, only four species shared all five of these characteristics. More than 96% of the samples were visually identified as M. galloprovincialis feces on the basis of morphology of the particles containing the appropriate mitochondrial DNA. These results suggest that mussel feces can be discriminated with high accuracy on the basis of their morphological characteristics. Thus, our method can be used to quantitatively assess the effect of mussel feces on local benthic environments. Copyright © 2016 Elsevier Ltd. All rights reserved.

NOTE: Development of modified voxel phantoms for the numerical dosimetric reconstruction of radiological accidents involving external sources: implementation in SESAME tool

NASA Astrophysics Data System (ADS)

Courageot, Estelle; Sayah, Rima; Huet, Christelle

2010-05-01

Estimating the dose distribution in a victim's body is a relevant indicator in assessing biological damage from exposure in the event of a radiological accident caused by an external source. When the dose distribution is evaluated with a numerical anthropomorphic model, the posture and morphology of the victim have to be reproduced as realistically as possible. Several years ago, IRSN developed a specific software application, called the simulation of external source accident with medical images (SESAME), for the dosimetric reconstruction of radiological accidents by numerical simulation. This tool combines voxel geometry and the MCNP(X) Monte Carlo computer code for radiation-material interaction. This note presents a new functionality in this software that enables the modelling of a victim's posture and morphology based on non-uniform rational B-spline (NURBS) surfaces. The procedure for constructing the modified voxel phantoms is described, along with a numerical validation of this new functionality using a voxel phantom of the RANDO tissue-equivalent physical model.

Development of modified voxel phantoms for the numerical dosimetric reconstruction of radiological accidents involving external sources: implementation in SESAME tool.

PubMed

Courageot, Estelle; Sayah, Rima; Huet, Christelle

2010-05-07

Estimating the dose distribution in a victim's body is a relevant indicator in assessing biological damage from exposure in the event of a radiological accident caused by an external source. When the dose distribution is evaluated with a numerical anthropomorphic model, the posture and morphology of the victim have to be reproduced as realistically as possible. Several years ago, IRSN developed a specific software application, called the simulation of external source accident with medical images (SESAME), for the dosimetric reconstruction of radiological accidents by numerical simulation. This tool combines voxel geometry and the MCNP(X) Monte Carlo computer code for radiation-material interaction. This note presents a new functionality in this software that enables the modelling of a victim's posture and morphology based on non-uniform rational B-spline (NURBS) surfaces. The procedure for constructing the modified voxel phantoms is described, along with a numerical validation of this new functionality using a voxel phantom of the RANDO tissue-equivalent physical model.

Evaluation of healing and external tunnel histology of silver-coated peritoneal catheters in rats.

PubMed

Kathuria, P; Moore, H L; Mehrotra, R; Prowant, B F; Khanna, R; Twardowski, Z J

1996-01-01

A previous study showed that silver-coating peritoneal catheters tended to decrease the incidence of early exit-site infections in rats. This study was designed to further evaluate the healing, biocompatability, and external tunnel morphology of standard and silver-coated catheters. Catheters were coated with silver by an ion beam-assisted process. Fourteen male Sprague-Dawley rats underwent implantation of either a standard or silver-coated double-cuff peritoneal catheter. Weekly observation and photographs documented exit-site characteristics. Erythema, exudate, loose fit, and poor hair growth were evidence of an inflamed exit. Overt infection was indicated by the presence of three or more of the following: erythema, purulent exudate, exuberant granulation tissue, loose fit, and poor hair growth. Animals were sacrificed at six weeks, and catheters were removed and processed for histology of the external tunnel. Multiple measurements were taken using a Filar eyepiece, and data were expressed as a mean of several readings. Inflammation, vascularity, and fibrosis were judged semiquantitatively. At the end of six weeks, six of the seven exits of the silver catheters showed excellent healing, while one exit site had signs of excessive inflammation. Four of the exit sites of the standard catheters healed well, two were inflamed, and one was overtly infected. The sinus tract of the standard and silver catheters had similar characteristics: keratinized and nonkeratinized epithelium lined the external part of the sinus tract and merged into granulation tissue. A fibrous sheath was noted in some sinus tracts between the granulation tissue and the cuff. The cuff evoked a foreign body reaction, with fibrosis, multiple giant cells, and vascularization. Poorly healing or infected sinus tracts had highly vascular granulation tissue with overlying exudate. The cuff of these catheters had marked inflammation and scanty giant cells, although collagen bundle thickness was similar to the well-healing catheters. In conclusion, silver-coating potentially enhances healing of the exit sites of peritoneal catheters. Additionally, the similarity of the tunnel histomorphology of standard and silver catheters confirms the favorable biocompatibility of silver.

Bat Species Comparisons Based on External Morphology: A Test of Traditional versus Geometric Morphometric Approaches

PubMed Central

Schmieder, Daniela A.; Benítez, Hugo A.; Borissov, Ivailo M.; Fruciano, Carmelo

2015-01-01

External morphology is commonly used to identify bats as well as to investigate flight and foraging behavior, typically relying on simple length and area measures or ratios. However, geometric morphometrics is increasingly used in the biological sciences to analyse variation in shape and discriminate among species and populations. Here we compare the ability of traditional versus geometric morphometric methods in discriminating between closely related bat species – in this case European horseshoe bats (Rhinolophidae, Chiroptera) – based on morphology of the wing, body and tail. In addition to comparing morphometric methods, we used geometric morphometrics to detect interspecies differences as shape changes. Geometric morphometrics yielded improved species discrimination relative to traditional methods. The predicted shape for the variation along the between group principal components revealed that the largest differences between species lay in the extent to which the wing reaches in the direction of the head. This strong trend in interspecific shape variation is associated with size, which we interpret as an evolutionary allometry pattern. PMID:25965335

[Influence of surface chemical properties and pore structure characteristics of activated carbon on the adsorption of nitrobenzene from aqueous solution].

PubMed

Liu, Shou-Xin; Chen, Xi; Zhang, Xian-Quan

2008-05-01

Commercial activated carbon was treated by HNO3 oxidation and then subsequently heat treated under N2 atmosphere. Effect of surface chemical properties and pore structure on the adsorption performance of nitrobenzene was investigated. N2/77K adsorption isotherm and scanning electron microscopy (SEM) were used to characterize the pore structure and surface morphology of carbon. Boehm titration, Fourier transform infrared spectroscopy (FTIR), the point of zero charge (pH(PZC)) measurement and elemental analysis were used to characterize the surface properties. The results reveal that HNO3 oxidation can modify the surface chemical properties, increase the number of acidic surface oxygen-containing groups and has trivial effect on the pore structure of carbon. Further heat treatment can cause the decomposition of surface oxygen-containing groups, and increase the external surface area and the number of mesopores. Adsorption capacity of nitrobenzene on AC(NO-T), AC(raw) and AC(NO) was 1011.31, 483.09 and 321.54 mg x g(-1), respectively. Larger external surface area and the number of meso-pores, together with the less acid surface oxygen-containing groups were the main reason for the larger adsorption capacity AC(NO-T).

The Centipede Genus Scolopendra in Mainland Southeast Asia: Molecular Phylogenetics, Geometric Morphometrics and External Morphology as Tools for Species Delimitation

PubMed Central

Siriwut, Warut; Edgecombe, Gregory D.; Sutcharit, Chirasak; Panha, Somsak

2015-01-01

Seven Scolopendra species from the Southeast Asian mainland delimited based on standard external morphological characters represent monophyletic groups in phylogenetic trees inferred from concatenated sequences of three gene fragments (cytochrome c oxidase subunit 1, 16S rRNA and 28S rRNA) using Maximum likelihood and Bayesian inference. Geometric morphometric description of shape variation in the cephalic plate, forcipular coxosternite, and tergite of the ultimate leg-bearing segment provides additional criteria for distinguishing species. Colouration patterns in some Scolopendra species show a high degree of fit to phylogenetic trees at the population level. The most densely sampled species, Scolopendra dehaani Brandt, 1840, has three subclades with allopatric distributions in mainland SE Asia. The molecular phylogeny of S. pinguis Pocock, 1891, indicated ontogenetic colour variation among its populations. The taxonomic validation of S. dawydoffi Kronmüller, 2012, S. japonica Koch, 1878, and S. dehaani Brandt, 1840, each a former subspecies of S. subspinipes Leach, 1814 sensu Lewis, 2010, as full species was supported by molecular information and additional morphological data. Species delimitation in these taxonomically challenging animals is facilitated by an integrative approach that draws on both morphology and molecular phylogeny. PMID:26270342

Recessive myosin myopathy with external ophthalmoplegia associated with MYH2 mutations.

PubMed

Tajsharghi, Homa; Hammans, Simon; Lindberg, Christopher; Lossos, Alexander; Clarke, Nigel F; Mazanti, Ingrid; Waddell, Leigh B; Fellig, Yakov; Foulds, Nicola; Katifi, Haider; Webster, Richard; Raheem, Olayinka; Udd, Bjarne; Argov, Zohar; Oldfors, Anders

2014-06-01

Myosin myopathies comprise a group of inherited diseases caused by mutations in myosin heavy chain (MyHC) genes. Homozygous or compound heterozygous truncating MYH2 mutations have been demonstrated to cause recessive myopathy with ophthalmoplegia, mild-to-moderate muscle weakness and complete lack of type 2A muscle fibers. In this study, we describe for the first time the clinical and morphological characteristics of recessive myosin IIa myopathy associated with MYH2 missense mutations. Seven patients of five different families with a myopathy characterized by ophthalmoplegia and mild-to-moderate muscle weakness were investigated. Muscle biopsy was performed to study morphological changes and MyHC isoform expression. Five of the patients were homozygous for MYH2 missense mutations, one patient was compound heterozygous for a missense and a nonsense mutation and one patient was homozygous for a frame-shift MYH2 mutation. Muscle biopsy demonstrated small or absent type 2A muscle fibers and reduced or absent expression of the corresponding MyHC IIa transcript and protein. We conclude that mild muscle weakness and ophthalmoplegia in combination with muscle biopsy demonstrating small or absent type 2A muscle fibers are the hallmark of recessive myopathy associated with MYH2 mutations.

Tidal distortions in pairs of early-type galaxies

NASA Technical Reports Server (NTRS)

Prugniel, Philippe; Davoust, E.

1990-01-01

The authors are conducting an imaging survey of pairs of elliptical galaxies which has already produced interesting results. Some pairs present a common pattern of distortion interpreted in terms of tidal effects (Davoust and Prugniel, 1988; Prugniel et al., 1989). Other examples drawn from the literature (Borne and Hoessel, 1988; Colina and Perez-Fournon, 1990) share the same morphology. New cases and lists of the characteristics of 24 such systems. The authors' pairs are drawn from a sample of binary and multiple galaxies which has in turn been extracted from the CGCG, UGC (Nilson, 1973) and VV (Vorontsov-Velyaminov, 1959) catalogues. This sample includes that of Karachentsev (1972). It contains 1800 pairs, among which 700 are S - S or mixed morphology pairs. The authors are working on the remainder to produce a sample of close physical pairs of elliptical galaxies (they also include bulge dominated SO's since the morphological discrimination from ellipticals is often ambiguous, in particular for interacting galaxies). One of the interests of this work is to provide a sample selected on purely optical criteria, at variance with other works (e.g., Valentijn and Casertano, 1988). This will allow statistical studies of non-optical properties of these pairs (in particular radio emission). The authors have so far obtained charge-coupled device (CCD) images of 125 pairs with a 2m telescope and velocities' differences of 78 pairs were obtained using the 1.93 meter telescope of Observatoire de Haute Provence and from the literature. One is an optical pair (VV 190). Eighteen of our pairs present the morphological effect described in Davoust and Prugniel (1988): the external parts of each member are stretched in opposite senses in a direction rougly perpendicular to the pair axis. The proportion of 15 plus or minus 4 percent distorted pairs confirms previous estimates. Except for a few cases involving flattened galaxies with nearly aligned major axes which deserve careful detailed analysis (Prugniel, 1989), the apparent distortions do correspond to physical distortions. We have searched the literature for isophote maps showing this effect. In the survey of radio galaxies by Colina and Perez-Fournon (1990), 7 out of 20 pairs show this characteristic distortion.

A comparison of the morphological and physiochemical characteristics of ten carambola cultivars

USDA-ARS?s Scientific Manuscript database

Carambola (Averrhoa carambola L.) was grown on a Krome gravely loam soil (Loamy-skeletal, carbonic, hyperthermic Lithic Udorthents) in Miami, FL. Carambola morphological characteristics were determined by measuring fruit length, diameter and weight. Carambola physiochemical characteristics were det...

New "missing link" genus of the colonial volvocine green algae gives insights into the evolution of oogamy.

PubMed

Nozaki, Hisayoshi; Yamada, Toshihiro K; Takahashi, Fumio; Matsuzaki, Ryo; Nakada, Takashi

2014-03-03

The evolution of oogamy from isogamy, an important biological event, can be summarized as follows: morphologically similar gametes (isogametes) differentiated into small "male" and large "female" motile gametes during anisogamy, from which immotile female gametes (eggs) evolved. The volvocine green algae represent a model lineage to study this type of sex evolution and show two types of gametic unions: conjugation between isogametes outside the parental colonies (external fertilization during isogamy) and fertilization between small motile gametes (sperm) and large gametes (eggs) inside the female colony (internal fertilization during anisogamy and oogamy). Although recent cultural studies on volvocine algae revealed morphological diversity and molecular genetic data of sexual reproduction, an intermediate type of union between these two gametic unions has not been identified. We identified a novel colonial volvocine genus, Colemanosphaera, which produces bundles of spindle-shaped male gametes through successive divisions of colonial cells. Obligately anisogamous conjugation between male and female motile gametes occurred outside the female colony (external fertilization during anisogamy). This new genus contains 16- or 32-celled spheroidal colonies similar to those of the volvocine genera Yamagishiella and Eudorina. However, Colemanosphaera can be clearly distinguished from these two genera based on its sister phylogenetic position to the enigmatic flattened colonial volvocine Platydorina and external fertilization during anisogamy. Two species of Colemanosphaera were found in a Japanese lake; these species are also distributed in European freshwaters based on a published sequence of an Austrian strain and the original description of Pandorina charkowiensis from Ukraine. Based on phylogeny and morphological data, this novel genus exhibits a missing link between Platydorina and the typical spheroidal colonial volvocine members such as Pandorina or Yamagishiella. Considering the external obligate anisogamy, oogamy evolution may have been preceded by the transition from external to internal fertilization during anisogamy within the volvocine green algae.

The role of audience characteristics and external factors in continuing medical education and physician change: effectiveness of continuing medical education: American College of Chest Physicians Evidence-Based Educational Guidelines.

PubMed

Lowe, Mary Martin; Bennett, Nancy; Aparicio, Alejandro

2009-03-01

The Agency for Healthcare Research and Quality (AHRQ) Evidence Report identified and assessed audience characteristics (internal factors) and external factors that influence the effectiveness of continuing medical education (CME) in changing physician behavior. Thirteen studies examined a series of CME audience characteristics (internal factors), and six studies looked at external factors to reinforce the effects of CME in changing behavior. With regard to CME audience characteristics, the 13 studies examined age, gender, practice setting, years in practice, specialty, foreign vs US medical graduate, country of practice, personal motivation, nonmonetary rewards and motivations, learning satisfaction, and knowledge enhancement. With regard to the external characteristics, the six studies looked at the role of regulation, state licensing boards, professional boards, hospital credentialing, external audits, monetary and financial rewards, academic advancement, provision of tools, public demand and expectations, and CME credit. No consistent findings were identified. The AHRQ Evidence Report provides no conclusions about the ways that internal or external factors influence CME effectiveness in changing physician behavior. However, given what is known about how individuals approach learning, it is likely that internal factors play an important role in the design of effective CME. Regulatory and professional organizations are providing new structures, mandates, and recommendations for CME activities that influence the way CME providers design and present activities, supporting a role that is not yet clear for external factors. More research is needed to understand the impact of these factors in enhancing the effectiveness of CME.

An Additional Potential Factor for Kidney Stone Formation during Space Flights: Calcifying Nanoparticles (Nanobacteria): A Case Report

NASA Technical Reports Server (NTRS)

Jones, Jeffrey A.; Ciftcioglu, Neva; Schmid, Joseph; Griffith, Donald

2007-01-01

Spaceflight-induced microgravity appears to be a risk factor for the development of urinary calculi due to skeletal calcium liberation and other undefined factors, resulting in stone disease in crewmembers during and after spaceflight. Calcifying nanoparticles, or nanobacteria, reproduce at a more rapid rate in simulated microgravity conditions and create external shells of calcium phosphate in the form of apatite. The questions arises whether calcifying nanoparticles are niduses for calculi and contribute to the development of clinical stone disease in humans, who possess environmental factors predisposing to the development of urinary calculi and potentially impaired immunological defenses during spaceflight. A case of a urinary calculus passed from an astronaut post-flight with morphological characteristics of calcifying nanoparticles and staining positive for a calcifying nanoparticle unique antigen, is presented.

Morphological characteristics of Street Workout practitioners.

PubMed

Sanchez-Martinez, Javier; Plaza, Paula; Araneda, Alberto; Sánchez, Patricio; Almagiâ, Atilio

2017-02-01

The determination of the morphological characteristics of the most popular sports has allowed the evaluation and comparison between athletes, which has helped to improve their performance. The Street Workout is an emerging sport based on calisthenics, which recently has become popular. Despite its popularization, neither the morphologic profile nor the morphologic characteristics of Street Workout athletes has been determined. Determine the profile and morphological characteristics of Street-Workout athletes, through anthropometry. Fourteen athletes (22.7 ± 3.26 years) were recruited from the National Calisthenics Tournament 2015 in Chile. The athletes were evaluated following the protocol of the International Society for the Advancement of Kinanthropometry to determine the somatotype, body composition, as well as indices of body composition such as body mass index, waist to hip ratio, waist to height ratio, fat/muscle mass and muscle/bone mass indexes. Street Workout practitioners presented a balanced-mesomorphic somatotype, a low fat mass and a high muscular development, with upper arms and trunk predominance. Regarding body composition indices, the values obtained allow us to classify them as a low-risk population of chronic non-communicable diseases. The present study sets a first antecedent of the morphological characteristics of Street Workout, determining that the Street Workout athletes presented balanced-mesomorphic somatotype and were classified as a healthy and athletic sample by their body composition indexes.

Morphological and Spectral Characteristics of Hybrid Nanosystems Based on Mono- and Bimetallic Platinum Nanoparticles and Silver

NASA Astrophysics Data System (ADS)

Valueva, S. V.; Vylegzhanina, M. E.; Sukhanova, T. E.

2018-02-01

Morphological and spectral characteristics of hybrid nanosystems (NSes) based on mono- and bimetallic silver and platinum nanoparticles (NPs) stabilized by a cationic polyelectrolyte (CP), poly- N,N,N,N-trimethylmethacryloyloxyethylammonium methylsulfate, are determined via static/dynamic light scattering, UV spectroscopy, and atomic force microscopy. The formation of dense spherical polymolecular nanostructures is established. The possibility of controlling the morphological and spectral characteristics of the NS is shown by varying the nature and composition of NPs.

Mitigation of landslide area around railway tunnel, South Sumatra Province, Indonesia

NASA Astrophysics Data System (ADS)

Toha, M. Taufik; Setiabudidaya, Dedi; Komar, Syamsul; Bochori, Ghadafi, Moamar A.; Adiwarman, Mirza; Rahim, S. E.

2017-09-01

Adequate and safe railway line infrastructures as well as facilities are required to support the rail transport system in South Sumatra. The slope stability along railway line of Lahat-Lubuk Linggau South Sumatra were studied during landslide that occured on January 23th, 2016. The landslide occurred on the mouth of railway tunnel in Gunung Gajah Village, Lahat District that causing the railway transportation system had to be stopped for a few days. A comprehensive research was conducted to analyze the causes of the landslide and to identify other landslide risky areas along the railway line Lahat-Lubuk Linggau. The research activities included surveying, sampling, laboratory testing, investigating condition of geology, geotechnics, hydrogeology/hydrology, morphology and land use. The factors that cause landslide in the past studies were found to be morphology, structural geology, physical and mechanical characteristics, hydrogeology, hydrology, external forces (train vibration, earthquake). Results back analysis of slope stability when the landslide occurred showed that the value Safety Factor (SF) = 1, angle of friction = 0°, and cohesion = 0.49 kg/cm2 (49 kPa). Based on the observation and analysis of the condition of the morphology and orientation of the structure of the rock layers, there was a location prone to landslide (labile) in the surrounding area of the landslide. Mitigations to potential landslide in adjacent area were building a retaining wall, draining channels, and shortcrete at the rock wall after landslides and maintaining the land use around the slopes.

Redescription of Corallobothrium solidum (Cestoda: Proteocephalidea) and erection of a new genus, Essexiella, for tapeworms from channel catfishes (Ictaluridae).

PubMed

Scholz, Tomáš; de Chambrier, Alain; Mariaux, Jean; Kuchta, Roman

2011-12-01

The proteocephalidean tapeworm, Corallobothrium solidum, type species of the genus, is redescribed on the basis of the examination of its type specimens and extensive material recently collected from Malapterurus electricus (type host). Some morphological characteristics of taxonomic importance are reported for the first time, such as the presence of semispherical (U-shaped) sphincters on the external (outer) margin of the suckers, a vaginal sphincter, a well-developed seminal receptacle, and a unique morphology of the eggs. Corallobothrium solidum differs from the 2 remaining species of the genus, both parasitic in channel catfishes (Ictaluridae), in its scolex shape, morphology of its suckers, presence of longitudinal and transverse grooves on the body surface, dense network of excretory canals in the apical part of the scolex, morphology of the eggs, and uterine development. The non-monophyletic nature of Corallobothrium is further supported by molecular data (partial sequences of the 28S rRNA gene) because C. solidum and the 2 remaining species from ictalurids do not form a monophyletic assemblage. Therefore, Essexiella n. gen. is proposed to accommodate Essexiella fimbriatum new comb. (type and only species; syn. Corallobothrium fimbriatum) from channel catfish. Essexiella n. gen. differs from Corallobothrium, Megathylacoides, and Megathylacus by the absence of a sphincter in the suckers, from Corallotaenia by the shape of the scolex and the number and shape of proglottids, and from Paraproteocephalus by the structure of the uterus. The diagnosis of Corallobothrium, which becomes monotypic and restricted to electric catfishes in Africa, is emended. The remaining species of Corallobothrium, Corallobothrium parafimbriatum, is tentatively transferred to Corallotaenia as Corallotaenia parafimbriata n. comb., based on molecular data, small size of the strobila, and shape of the scolex.

An algorithm for verifying biventricular capture based on evoked-response morphology.

PubMed

Diotallevi, Paolo; Ravazzi, Pier Antonio; Gostoli, Enrico; De Marchi, Giuseppe; Militello, Carmelo; Kraetschmer, Hannes

2005-01-01

Cardiac resynchronization therapy relies on consistent beat-by-beat myocardial capture in both ventricles. A pacemaker ensuring right (RV) and left ventricular (LV) capture through reliable capture verification and automatic output adjustment would contribute to patients' safety and quality of life. We studied the feasibility of an algorithm based on evoked-response (ER) morphology for capture verification in both the ventricles. RV and LV ER signals were recorded in 20 patients (mean age 72.5 years, range 64.3-80.4 years, 4 females and 16 males) during implantation of biventricular (BiV) pacing systems. Leads of several manufacturers were tested. Pacing and intracardiac electrogram (IEGM) recording were performed using an external pulse generator. IEGM and surface-lead electrocardiogram (ECG) signals were recorded under different pacing conditions for 10 seconds each: RV pacing only, LV pacing only, and BiV pacing with several interventricular delays. Based on morphology characteristics, ERs were classified manually for capture and failure to capture, and the validity of the classification was assessed by reference to the ECG. A total of 3,401 LV- and 3,345 RV-paced events were examined. In the RV and LV, the sensitivities of the algorithm were 95.6% and 96.1% in the RV and LV, respectively, and the corresponding specificities were 91.4% and 95.2%, respectively. The lower sensitivity in the RV was attributed to signal blanking in both channels during BiV pacing with a nonzero interventricular delay. The analysis revealed that the algorithm for identifying capture and failure to capture based on the ER-signal morphology was safe and effective in each ventricle with all leads tested in the study.

170 Years of “Lock-and-Key”: Genital Morphology and Reproductive Isolation

PubMed Central

Masly, John P.

2012-01-01

The divergent genital morphology observed among closely related animal species has long been posited as a mechanism of reproductive isolation. Despite the intuitive appeal that rapidly evolving genitalia might cause speciation, evidence for its importance—or even its potential—in reproductive isolation is mixed. Most tests of genital structural isolation between species often fail to find convincing evidence that differences in morphology prevent copulation or insemination between species. However, recent work suggests that differences in genital morphology might contribute to reproductive isolation in less obvious ways through interactions with sensory mechanisms that result in lowered reproductive fitness in heterospecific matings. In this paper, I present a brief history of the “lock-and-key” hypothesis, summarize the evidence for the involvement of genital morphology in different mechanisms of reproductive isolation, discuss progress in identifying the molecular and genetic bases of species differences in genital morphology, and discuss prospects for future work on the role of genitalia in speciation. L'armure copulatrice est un organe ou mieux un instrument ingénieusement compliqué, destiné à s'adapter aux parties sexuelles externes de la femelle pour l'accomplissement de l'acte copulatif; elle est la garantie de la conservation des types, la sauvegarde de la légitimité de l'espèce. [The copulation armor is an organ or better an instrument ingeniously complicated, destined to adapt to sexual parts external to the female for the completion of copulation; it is the guarantee of the preservation of the standards, the safeguard of the legitimacy of the species.] L. Dufour, 1844 PMID:22263116

Which morphological characteristics are most influenced by the host matrix in downy mildews? A case study in Pseudoperonospora cubensis.

PubMed

Runge, Fabian; Ndambi, Beninweck; Thines, Marco

2012-01-01

Before the advent of molecular phylogenetics, species concepts in the downy mildews, an economically important group of obligate biotrophic oomycete pathogens, have mostly been based upon host range and morphology. While molecular phylogenetic studies have confirmed a narrow host range for many downy mildew species, others, like Pseudoperonospora cubensis affect even different genera. Although often morphological differences were found for new, phylogenetically distinct species, uncertainty prevails regarding their host ranges, especially regarding related plants that have been reported as downy mildew hosts, but were not included in the phylogenetic studies. In these cases, the basis for deciding if the divergence in some morphological characters can be deemed sufficient for designation as separate species is uncertain, as observed morphological divergence could be due to different host matrices colonised. The broad host range of P. cubensis (ca. 60 host species) renders this pathogen an ideal model organism for the investigation of morphological variations in relation to the host matrix and to evaluate which characteristics are best indicators for conspecificity or distinctiveness. On the basis of twelve morphological characterisitcs and a set of twelve cucurbits from five different Cucurbitaceae tribes, including the two species, Cyclanthera pedata and Thladiantha dubia, hitherto not reported as hosts of P. cubensis, a significant influence of the host matrix on pathogen morphology was found. Given the high intraspecific variation of some characteristics, also their plasticity has to be taken into account. The implications for morphological species determination and the confidence limits of morphological characteristics are discussed. For species delimitations in Pseudoperonospora it is shown that the ratio of the height of the first ramification to the sporangiophore length, ratio of the longer to the shorter ultimate branchlet, and especially the length and width of sporangia, as well as, with some reservations, their ratio, are the most suitable characteristics for species delimitation.

Which Morphological Characteristics Are Most Influenced by the Host Matrix in Downy Mildews? A Case Study in Pseudoperonospora cubensis

PubMed Central

Runge, Fabian; Ndambi, Beninweck; Thines, Marco

2012-01-01

Before the advent of molecular phylogenetics, species concepts in the downy mildews, an economically important group of obligate biotrophic oomycete pathogens, have mostly been based upon host range and morphology. While molecular phylogenetic studies have confirmed a narrow host range for many downy mildew species, others, like Pseudoperonospora cubensis affect even different genera. Although often morphological differences were found for new, phylogenetically distinct species, uncertainty prevails regarding their host ranges, especially regarding related plants that have been reported as downy mildew hosts, but were not included in the phylogenetic studies. In these cases, the basis for deciding if the divergence in some morphological characters can be deemed sufficient for designation as separate species is uncertain, as observed morphological divergence could be due to different host matrices colonised. The broad host range of P. cubensis (ca. 60 host species) renders this pathogen an ideal model organism for the investigation of morphological variations in relation to the host matrix and to evaluate which characteristics are best indicators for conspecificity or distinctiveness. On the basis of twelve morphological characterisitcs and a set of twelve cucurbits from five different Cucurbitaceae tribes, including the two species, Cyclanthera pedata and Thladiantha dubia, hitherto not reported as hosts of P. cubensis, a significant influence of the host matrix on pathogen morphology was found. Given the high intraspecific variation of some characteristics, also their plasticity has to be taken into account. The implications for morphological species determination and the confidence limits of morphological characteristics are discussed. For species delimitations in Pseudoperonospora it is shown that the ratio of the height of the first ramification to the sporangiophore length, ratio of the longer to the shorter ultimate branchlet, and especially the length and width of sporangia, as well as, with some reservations, their ratio, are the most suitable characteristics for species delimitation. PMID:23166582

Computer analysis of three-dimensional morphological characteristics of the bile duct

NASA Astrophysics Data System (ADS)

Ma, Jinyuan; Chen, Houjin; Peng, Yahui; Shang, Hua

2017-01-01

In this paper, a computer image-processing algorithm for analyzing the morphological characteristics of bile ducts in Magnetic Resonance Cholangiopancreatography (MRCP) images was proposed. The algorithm consisted of mathematical morphology methods including erosion, closing and skeletonization, and a spline curve fitting method to obtain the length and curvature of the center line of the bile duct. Of 10 cases, the average length of the bile duct was 14.56 cm. The maximum curvature was in the range of 0.111 2.339. These experimental results show that using the computer image-processing algorithm to assess the morphological characteristics of the bile duct is feasible and further research is needed to evaluate its potential clinical values.

Evolutionary origins and development of saw-teeth on the sawfish and sawshark rostrum (Elasmobranchii; Chondrichthyes)

PubMed Central

Welten, Monique; Smith, Moya Meredith; Underwood, Charlie; Johanson, Zerina

2015-01-01

A well-known characteristic of chondrichthyans (e.g. sharks, rays) is their covering of external skin denticles (placoid scales), but less well understood is the wide morphological diversity that these skin denticles can show. Some of the more unusual of these are the tooth-like structures associated with the elongate cartilaginous rostrum ‘saw’ in three chondrichthyan groups: Pristiophoridae (sawsharks; Selachii), Pristidae (sawfish; Batoidea) and the fossil Sclerorhynchoidea (Batoidea). Comparative topographic and developmental studies of the ‘saw-teeth’ were undertaken in adults and embryos of these groups, by means of three-dimensional-rendered volumes from X-ray computed tomography. This provided data on development and relative arrangement in embryos, with regenerative replacement in adults. Saw-teeth are morphologically similar on the rostra of the Pristiophoridae and the Sclerorhynchoidea, with the same replacement modes, despite the lack of a close phylogenetic relationship. In both, tooth-like structures develop under the skin of the embryos, aligned with the rostrum surface, before rotating into lateral position and then attaching through a pedicel to the rostrum cartilage. As well, saw-teeth are replaced and added to as space becomes available. By contrast, saw-teeth in Pristidae insert into sockets in the rostrum cartilage, growing continuously and are not replaced. Despite superficial similarity to oral tooth developmental organization, saw-tooth spatial initiation arrangement is associated with rostrum growth. Replacement is space-dependent and more comparable to that of dermal skin denticles. We suggest these saw-teeth represent modified dermal denticles and lack the ‘many-for-one’ replacement characteristic of elasmobranch oral dentitions. PMID:26473044

Self-assembly preparation of SiO2@Ni-Al layered double hydroxide composites and their enhanced electrorheological characteristics

PubMed Central

Ji, Xuqiang; Zhang, Wenling; Shan, Lei; Tian, Yu; Liu, Jingquan

2015-01-01

The core-shell structured SiO2@Ni-Al layered double hydroxide (LDH) composites were prepared via self-assembly of Ni-Al LDH on the surface of SiO2 spheres. Only coating a layer of ultrathin Ni-Al LDH sheet, the resulting SiO2@Ni-Al LDH composites exhibit significantly enhanced electrorheological (ER) characteristics compared to conventional bare SiO2 spheres. The monodispersed SiO2 spheres with average diameters of 260 nm were synthesized by the hydrolysis of tetraethyl orthosilicate (TEOS), while the shell part, Ni-Al LDH sheet was prepared by the hydrothermal procedure. The morphology of the samples was investigated via scanning transmission electron microscopy (STEM), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The structure of the samples was characterized by X-ray diffraction (XRD). The species and distribution of elements in samples were confirmed by X-ray photoelectron spectroscopy (XPS), Energy dispersive analysis of X-ray (EDX) and elemental mapping in STEM. Subsequently, the ER characteristics of the composites dispersed in insulating oil were characterized by a rotational rheometer. The electric field-stimulated rheological performances (yield stress, viscosity, modulus, etc.) were observed under an external electric field, which is different from the Newtonian state in the free electric field. PMID:26670467

Self-assembly preparation of SiO2@Ni-Al layered double hydroxide composites and their enhanced electrorheological characteristics

NASA Astrophysics Data System (ADS)

Ji, Xuqiang; Zhang, Wenling; Shan, Lei; Tian, Yu; Liu, Jingquan

2015-12-01

The core-shell structured SiO2@Ni-Al layered double hydroxide (LDH) composites were prepared via self-assembly of Ni-Al LDH on the surface of SiO2 spheres. Only coating a layer of ultrathin Ni-Al LDH sheet, the resulting SiO2@Ni-Al LDH composites exhibit significantly enhanced electrorheological (ER) characteristics compared to conventional bare SiO2 spheres. The monodispersed SiO2 spheres with average diameters of 260 nm were synthesized by the hydrolysis of tetraethyl orthosilicate (TEOS), while the shell part, Ni-Al LDH sheet was prepared by the hydrothermal procedure. The morphology of the samples was investigated via scanning transmission electron microscopy (STEM), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The structure of the samples was characterized by X-ray diffraction (XRD). The species and distribution of elements in samples were confirmed by X-ray photoelectron spectroscopy (XPS), Energy dispersive analysis of X-ray (EDX) and elemental mapping in STEM. Subsequently, the ER characteristics of the composites dispersed in insulating oil were characterized by a rotational rheometer. The electric field-stimulated rheological performances (yield stress, viscosity, modulus, etc.) were observed under an external electric field, which is different from the Newtonian state in the free electric field.

Study on transport properties of silicene monolayer under external field using NEGF method

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

Syaputra, Marhamni, E-mail: marhamni@students.itb.ac.id; Wella, Sasfan Arman; Wungu, Triati Dewi Kencana

2015-09-30

We investigate the current-voltage (I-V) characteristics of a pristine monolayer silicene using non-equilibrium Green function (NEGF) method combining with density functional theory (DFT). This method succeeded in showing the relationship of I and V on silicene corresponding to the electronic characteristics such as density of states. The external field perpendicular to the silicene monolayer affects in increasing of the current. Under 0.2 eV external field, the current reaches the maximum peak at Vb = 0.3 eV with the increase is about 60% from what it is in zero external field.

Effects of Performers' External Characteristics on Performance Evaluations.

ERIC Educational Resources Information Center

Bermingham, Gudrun A.

2000-01-01

States that fairness has been a major concern in the field of music adjudication. Reviews the research literature to reveal information about three external characteristics (race, gender, and physical attractiveness) that may affect judges' performance evaluations and influence fairness of music adjudication. Includes references. (CMK)

Accurate reconstruction of the jV-characteristic of organic solar cells from measurements of the external quantum efficiency

NASA Astrophysics Data System (ADS)

Meyer, Toni; Körner, Christian; Vandewal, Koen; Leo, Karl

2018-04-01

In two terminal tandem solar cells, the current density - voltage (jV) characteristic of the individual subcells is typically not directly measurable, but often required for a rigorous device characterization. In this work, we reconstruct the jV-characteristic of organic solar cells from measurements of the external quantum efficiency under applied bias voltages and illumination. We show that it is necessary to perform a bias irradiance variation at each voltage and subsequently conduct a mathematical correction of the differential to the absolute external quantum efficiency to obtain an accurate jV-characteristic. Furthermore, we show that measuring the external quantum efficiency as a function of voltage for a single bias irradiance of 0.36 AM1.5g equivalent sun provides a good approximation of the photocurrent density over voltage curve. The method is tested on a selection of efficient, common single-junctions. The obtained conclusions can easily be transferred to multi-junction devices with serially connected subcells.

Preparation research of Nano-SiC/Ni-P composite coating under a compound field

NASA Astrophysics Data System (ADS)

Zhou, H. Z.; Wang, W. H.; Gu, Y. Q.; Liu, R.; Zhao, M. L.

2016-07-01

In this paper, the preparation process of Ni-P-SiC composite coatings on 45 steel surfaces with the assistance of magnetic and ultrasound fields was researched. The influence of external field on the surface morphology and performance of the composite layer is also discussed. Experimental results showed that when prepared under magnetic and ultrasonic fields, composite layers are significantly more dense and uniform than coatings made without external fields. Nano-SiC particles, dispersed uniformly in the layer, significantly improve the hardness of the composite layer, and the composite layer under the external field had the highest hardness at 680 HV The external fields can also accelerate deposition and increase the thickness of the layer. Compared to layers processed without the assistance of external fields, the thickness of the layers increased by nearly ten µm.

Sexual dimorphism of sonic apparatus and extreme intersexual variation of sounds in Ophidion rochei (Ophidiidae): first evidence of a tight relationship between morphology and sound characteristics in Ophidiidae

PubMed Central

2012-01-01

Background Many Ophidiidae are active in dark environments and display complex sonic apparatus morphologies. However, sound recordings are scarce and little is known about acoustic communication in this family. This paper focuses on Ophidion rochei which is known to display an important sexual dimorphism in swimbladder and anterior skeleton. The aims of this study were to compare the sound producing morphology, and the resulting sounds in juveniles, females and males of O. rochei. Results Males, females, and juveniles possessed different morphotypes. Females and juveniles contrasted with males because they possessed dramatic differences in morphology of their sonic muscles, swimbladder, supraoccipital crest, and first vertebrae and associated ribs. Further, they lacked the ‘rocker bone’ typically found in males. Sounds from each morphotype were highly divergent. Males generally produced non harmonic, multiple-pulsed sounds that lasted for several seconds (3.5 ± 1.3 s) with a pulse period of ca. 100 ms. Juvenile and female sounds were recorded for the first time in ophidiids. Female sounds were harmonic, had shorter pulse period (±3.7 ms), and never exceeded a few dozen milliseconds (18 ± 11 ms). Moreover, unlike male sounds, female sounds did not have alternating long and short pulse periods. Juvenile sounds were weaker but appear to be similar to female sounds. Conclusions Although it is not possible to distinguish externally male from female in O. rochei, they show a sonic apparatus and sounds that are dramatically different. This difference is likely due to their nocturnal habits that may have favored the evolution of internal secondary sexual characters that help to distinguish males from females and that could facilitate mate choice by females. Moreover, the comparison of different morphotypes in this study shows that these morphological differences result from a peramorphosis that takes place during the development of the gonads. PMID:23217241

Morphological evaluation of maxillary second molars with fused roots: a micro-CT study.

PubMed

Ordinola-Zapata, R; Martins, J N R; Bramante, C M; Villas-Boas, M H; Duarte, M H; Versiani, M A

2017-12-01

To evaluate the internal and external morphologies of fused-rooted maxillary second molars by means of micro-computed tomography (micro-CT) analysis. A total of 100 fused-rooted maxillary second molars from a Brazilian subpopulation were divided into six groups according to the root morphology. The samples were scanned at a resolution of 19.6 μm and evaluated with regard to the external morphology of the roots, the root canal configuration, the percentage frequency of C-shaped canals and isthmuses, as well as the morphology of the root canal system at 1, 2 and 3 mm from the anatomical apex of the fused roots. The most prevalent root canal fusions were type 1, mesiobuccal root fused with distobuccal root (32%), followed by type 3, DB root fused with P root (27%), and type 4, MB root fused with DB root, and P root fused with MB or DB roots (21%). The prevalence of C-shaped root canal systems were 22%. Depending on the type of root fusion, the percentage frequency of isthmuses in the apical level varied from 9.3% to 42.8%, whilst the presence of apical deltas ranged from 18.5% to 57.1% of teeth. The root canal system of maxillary second molars with fused roots may have a high incidence of merging canals, isthmuses, apical deltas and C-shaped configurations. © 2017 International Endodontic Journal. Published by John Wiley & Sons Ltd.

hamlet, a binary genetic switch between single- and multiple- dendrite neuron morphology.

PubMed

Moore, Adrian W; Jan, Lily Yeh; Jan, Yuh Nung

2002-08-23

The dendritic morphology of neurons determines the number and type of inputs they receive. In the Drosophila peripheral nervous system (PNS), the external sensory (ES) neurons have a single nonbranched dendrite, whereas the lineally related multidendritic (MD) neurons have extensively branched dendritic arbors. We report that hamlet is a binary genetic switch between these contrasting morphological types. In hamlet mutants, ES neurons are converted to an MD fate, whereas ectopic hamlet expression in MD precursors results in transformation of MD neurons into ES neurons. Moreover, hamlet expression induced in MD neurons undergoing dendrite outgrowth drastically reduces arbor branching.

Evaluation models of some morphological characteristics for talent scouting in sport.

PubMed

Rogulj, Nenad; Papić, Vladan; Cavala, Marijana

2009-03-01

In this paper, for the purpose of expert system evaluation within the scientific project "Talent scouting in sport", two methodological approaches for recognizing an athlete's morphological compatibility for various sports has been presented, evaluated and compared. First approach is based on the fuzzy logic and expert opinion about compatibility of proposed hypothetical morphological models for 14 different sports which are part of the expert system. Second approach is based on determining the differences between morphological characteristics of a tested individual and top athlete's morphological characteristics for particular sport. Logical and mathematical bases of both methodological approaches have been explained in detail. High prognostic efficiency in recognition of individual's sport has been determined. Some improvements in further development of both methods have been proposed. Results of the research so far suggest that this or similar approaches can be successfully used for detection of individual's morphological compatibility for different sports. Also, it is expected to be useful in the selection of young talents for particular sport.

Morphology of the external genitalia of the adult male and female mice as an endpoint of sex differentiation

PubMed Central

Weiss, Dana A.; Rodriguez, Esequiel; Cunha, Tristan; Menshenina, Julia; Barcellos, Dale; Chan, Lok Yun; Risbridger, Gail; Baskin, Laurence; Cunha, Gerald

2013-01-01

Adult external genitalia (ExG) are the endpoints of normal sex differentiation. Detailed morphometric analysis and comparison of adult mouse ExG has revealed 10 homologous features distinguishing the penis and clitoris that define masculine vs. feminine sex differentiation. These features have enabled the construction of a simple metric to evaluate various intersex conditions in mutant or hormonally manipulated mice. This review focuses on the morphology of the adult mouse penis and clitoris through detailed analysis of histologic sections, scanning electron microscopy, and three-dimensional reconstruction. We also present previous results from evaluation of “non-traditional” mammals, such as the spotted hyena and wallaby to demonstrate the complex process of sex differentiation that involves not only androgen-dependent processes, but also estrogen-dependent and hormone-independent mechanisms. PMID:21893161

Evolution of the felid brain.

PubMed

Radinsky, L

1975-01-01

Endocranial casts of 15 genera of fossil felids provide a record of felid brain evolution over the past 35 million years. Brains of the earliest felids, known as paleofelids, had coronolateral, suprasylvian and variably developed ectosylvian sulci as their only neocortical sulci. The last paleofelids, which became extinct around 8 million years ago, show little change in external brain morphology except for the addition of a presylvian sulcus. The other group of felids, the neofelids, appears about 25 million years ago, with coronolateral and suprasylvian sulci their main neocortical sulci, plus a discontinuous ectosylvian sulcus and small postlateral, sylvian and presylvian sulci. The posterior cerebellar vermis was straight and unexpanded. Beginnings of expansion of the sigmoid gyri and development of the cruciate sulcus are evident in neofelids 15-20 million years ago, and by 5-9 million years ago neofelids had brains that appear modern in external morphology. Endocasts of four genera of Pleistocene saber-toothed felids are similar in sulcal pattern to those of modern felids, except for Dinobastis, which had a unique expansion of visual cortex. Endocasts of 27 species of modern felids, representing the six commonly recognized genera, are strikingly similar in external morphology, although the brains of a few species, such as cheetahs, lynxes and jagouarundis, display distinguishing features. Modern felid brains average about the same size relative to body weight as do those of viverrids, but are about 25% smaller in relative size than those of canids. Olfactory bulbs are relatively smaller in felids than in canids or viverrids.

[Economic impact of external laboratory test].

PubMed

Takura, Tomoyuki

2006-11-01

The realities of the spread and the aim of the introduction, and an economical influence of an external laboratory tests were researched. As a result, 90% or more the ratio to have consigned the external whole became clear. But it is preferable to correspond about inspection item of about 70% in own facilities because of the characteristic of the medical institution and the inspection item. Moreover, when correct the unbridgeable gulf of characteristic of the realities of spread of present external laboratory tests inspection and the ranging of ideal external laboratory tests inspection that specialist thinks about, the needed medical payment was thought that the investment of about 50 billion yen a year was necessary to expand the inspection in own facilities, by calculated based on the stochastic model.

Propagation characteristics of a focused laser beam in a strontium barium niobate photorefractive crystal under reverse external electric field.

PubMed

Guo, Q L; Liang, B L; Wang, Y; Deng, G Y; Jiang, Y H; Zhang, S H; Fu, G S; Simmonds, P J

2014-10-01

The propagation characteristics of a focused laser beam in a SBN:75 photorefractive crystal strongly depend on the signal-to-background intensity ratio (R=I_s/I_b) under reverse external electric field. In the range 20>R>0.05, the laser beam shows enhanced self-defocusing behavior with increasing external electric field, while it shows self-focusing in the range 0.03>R>0.01. Spatial solitons are observed under a suitable reverse external electric field for R=0.025. A theoretical model is proposed to explain the experimental observations, which suggest a new type of soliton formation due to "enhancement" not "screening" of the external electrical field.

The postnatal development of the temporal part of the human temporomandibular joint. A quantitative study on skulls.

PubMed

Dibbets, J M; Dijkman, G E

1997-12-01

The morphology of the temporal part of the human temporomandibular joint (TMJ) changes drastically during postnatal development. The glenoid fossa will acquire its characteristic S shape and a tubercle will develop. The combined results of the literature and of this study allow a reconstruction of the actual growth processes. The roof of the glenoid fossa appears to enlarge forward by remodeling while sagittal and vertical growth is mainly achieved by deposition at the top of the tubercle. These latter changes result in a steeper slope of the eminence and take place in 3 phases, parallelling the eruption of the first incisors, the permanent first molars and the permanent second molars. While the zygomatic arch thickens by deposition at all surfaces, it also remodels downward relative to the external meatus. As a result, the neonate anulus occupies a lower position relative to this arch than does the adult meatus.

A Linnaeus NG (TM) interactive key to the Lithocolletinae of North-West Europe aimed at accelerating the accumulation of reliable biodiversity data (Lepidoptera, Gracillariidae).

PubMed

Doorenweerd, Camiel; van Haren, Merel M; Schermer, Maarten; Pieterse, Sander; van Nieukerken, Erik J

2014-01-01

We present an interactive key that is available online through any web browser without the need to install any additional software, making it an easily accessible tool for the larger public. The key can be found at http://identify.naturalis.nl/lithocolletinae. The key includes all 86 North-West European Lithocolletinae, a subfamily of smaller moths ("micro-moths") that is commonly not treated in field guides. The user can input data on several external morphological character systems in addition to distribution, host plant and even characteristics of the larval feeding traces to reach an identification. We expect that this will enable more people to contribute with reliable observation data on this group of moths and alleviate the workload of taxonomic specialists, allowing them to focus on other new keys or taxonomic work.

Multiscale 3D virtual dissections of 100-million-year-old flowers using X-ray synchrotron micro- and nanotomography.

PubMed

Moreau, Jean-David; Cloetens, Peter; Gomez, Bernard; Daviero-Gomez, Véronique; Néraudeau, Didier; Lafford, Tamzin A; Tafforeau, Paul

2014-02-01

A multiscale approach combining phase-contrast X-ray micro- and nanotomography is applied for imaging a Cretaceous fossil inflorescence in the resolution range from 0.75 μm to 50 nm. The wide range of scale views provides three-dimensional reconstructions from the external gross morphology of the inflorescence fragment to the finest exine sculptures of in situ pollen. This approach enables most of the characteristics usually observed under light microscopy, or with low magnification under scanning and transmission electron microscopy, to be obtained nondestructively. In contrast to previous tomography studies of fossil and extant flowers that used resolutions down to the micron range, we used voxels with a 50 nm side in local tomography scans. This high level of resolution enables systematic affinities of fossil flowers to be established without breaking or slicing specimens.

A new species of Rhytidognathus (Carabidae, Migadopini) from Argentina

PubMed Central

Roig-Juñent, Sergio; Rouaux, Julia

2012-01-01

Abstract The Migadopini are a small tribe of Carabidae with 47 species that occur in South America, Australia, and New Zealand, in the sub-Antarctic areas. In South America, most of the genera inhabit areas related to sub-Antartic Nothofagus forest except two monogeneric genera, the Ecuadorian genus Aquilex Moret and the Pampean genus Rhytidognathus Chaudoir. These two genera are geographically isolated from the remaining five South American genera. New material of Rhytidognathus from the northeast of Buenos Aires province and from Entre Ríos province permits establishing that the previous records of Rhytidognathus ovalis (Dejean) for Argentina were erroneous and that it belongs to a new species. Based on external morphological characters and from male and female genitalia we describe Rhytidognathus platensis as a new species. In this contribution we provide illustrations, keys, habitat characteristics and some biogeographic considerations on the distribution of Rhytidognathus. PMID:23275755

A new species of Rhytidognathus (Carabidae, Migadopini) from Argentina.

PubMed

Roig-Juñent, Sergio; Rouaux, Julia

2012-01-01

The Migadopini are a small tribe of Carabidae with 47 species that occur in South America, Australia, and New Zealand, in the sub-Antarctic areas. In South America, most of the genera inhabit areas related to sub-Antartic Nothofagus forest except two monogeneric genera, the Ecuadorian genus Aquilex Moret and the Pampean genus Rhytidognathus Chaudoir. These two genera are geographically isolated from the remaining five South American genera. New material of Rhytidognathus from the northeast of Buenos Aires province and from Entre Ríos province permits establishing that the previous records of Rhytidognathus ovalis (Dejean) for Argentina were erroneous and that it belongs to a new species. Based on external morphological characters and from male and female genitalia we describe Rhytidognathus platensis as a new species. In this contribution we provide illustrations, keys, habitat characteristics and some biogeographic considerations on the distribution of Rhytidognathus.

Dynamic oxidation behavior of TD-NiCr alloy with different surface pretreatments

NASA Technical Reports Server (NTRS)

Young, C. T.; Tenney, D. R.; Herring, H. W.

1975-01-01

Oxidation tests of TD-NiCr alloy with different surface pretreatments were conducted in a Mach-5 arc-jet at 1200 C and 0.002 lb/sec flowing air environment. The mechanisms responsible for the observed oxidation behavior are examined. The presence of atomic oxygen in the air stream plays a significant role in determining the oxidation characteristic of the alloy. The rate of Cr2O3 vaporization by formation of volatile CrO3 is greatly enhanced by the flowing conditions. The typical microstructure of oxides formed in the dynamic tests consists of an external layer of NiO with a porous mushroom-type morphology, an intermediate layer of NiO and Cr2O3 oxide mixture, and a continuous inner layer of Cr2O3 in contact with the Cr-depleted alloy substrate. Three basic processes underlying the formation of mushroom-type NiO are identified and discussed. The oxidation rate is determined by the rate of vaporization of NiO. Surface pretreatment has a significant effect on the oxidation behavior of the alloy in the early stage of oxidation, but becomes less important as exposure time increases. Mechanical polishing induces surface recrystallization, but promotes the concurrence of external growth of NiO and internal oxidation of the alloy in the dynamic atmosphere.

External macro- and micromorphology of the male of the stick insect Hermarchus leytensis (Insecta: Phasmatodea) with phylogenetic considerations.

PubMed

Gottardo, Marco; Vallotto, Davide

2014-04-01

External morphological features of adult males are described in the stick insect Hermarchus leytensis from the Philippines, a species belonging to the little-known euphasmatodean lineage Stephanacridini. Mouthparts are characterized by some likely specialized features: (1) a dentate dorsal cutting edge on the mandibles; (2) distinct differences in size and shape between the galeae; (3) absence of an apical field of trichomes on the galeae; and (4) lacinial setae not protruding from the mesal margin, which features three bearing-like protuberances. The latter character state represents a very unusual condition, not known in other phasmatodeans or even in polyneopteran insects. A distinctive characteristic of attachment devices is that each euplantula is divided into two separated pads with a smooth microstructure, as it also occurs in some members of the clade Schizodecema. Male terminalia exhibit character states previously unknown in Stephanacridini, including (1) a symmetrical type of vomer and (2) claspers equipped with ∼ 70 very minute ventral teeth on each thorn pad. Potential implications for the systematic placement of H. leytensis are discussed. The results also underline the importance of microanatomical investigations as source of substantial characters for future analyses on phasmatodean systematics. Copyright © 2014 Académie des sciences. Published by Elsevier SAS. All rights reserved.

[Achene morphology cluster analysis of Taraxacum F. H. Wigg. from northeast China and molecule systematics evidence determined by SRAP].

PubMed

Li, Hai-juan; Zhao, Xin; Jia, Qing-fei; Li, Tian-lai; Ning, Wei

2012-08-01

The achenes morphological and micro-morphological characteristics of six species of genus Taraxacum from northeastern China as well as SRAP cluster analysis were observed for their classification evidences. The achenes were observed by microscope and EPMA. Cluster analysis was given on the basis of the size, shape, cone proportion, color and surface sculpture of achenes. The Taraxacum inter-species achene shape characteristic difference is obvious, particularly spinulose distribution and size, achene color and achene size; with the Taraxacum plant achene shape the cluster method T. antungense Kitag. and the T. urbanum Kitag. should combine for the identical kind; the achene morphology cluster analysis and the SRAP tagged molecule systematics's cluster result retrieves in the table with "the Chinese flora". The class group to divide the result is consistent. Taraxacum plant achene shape characteristic stable conservative, may carry on the inter-species division and the sibship analysis according to the achene shape characteristic combination difference; the achene morphology cluster analysis as well as the SRAP tagged molecule systematics confirmation support dandelion classification result of "the Chinese flora".

Describing and Predicting Developmental Profiles of Externalizing Problems from Childhood to Adulthood

PubMed Central

Petersen, Isaac T.; Bates, John E.; Dodge, Kenneth A.; Lansford, Jennifer E.; Pettit, Gregory S.

2014-01-01

This longitudinal study considers externalizing behavior problems from ages 5 to 27 (N = 585). Externalizing problem ratings by mothers, fathers, teachers, peers, and self-report were modeled with growth curves. Risk and protective factors across many different domains and time frames were included as predictors of the trajectories. A major contribution of the study is in demonstrating how heterotypic continuity and changing measures can be handled in modeling changes in externalizing behavior over long developmental periods. On average, externalizing problems decreased from early childhood to preadolescence, increased during adolescence, and decreased from late adolescence to adulthood. There was strong nonlinear continuity in externalizing problems over time. Family process, peer process, stress, and individual characteristics predicted externalizing problems beyond the strong continuity of externalizing problems. The model accounted for 70% of the variability in the development of externalizing problems. The model’s predicted values showed moderate sensitivity and specificity in prediction of arrests, illegal drug use, and drunk driving. Overall, the study showed that by using changing, developmentally-relevant measures and simultaneously taking into account numerous characteristics of children and their living situations, research can model lengthy spans of development and improve predictions of the development of later, severe externalizing problems. PMID:25166430

A new genus and three new species of miniaturized microhylid frogs from Indochina (Amphibia: Anura: Microhylidae: Asterophryinae).

PubMed

Poyarkov, Nikolay A; Suwannapoom, Chatmongkon; Pawangkhanant, Parinya; Aksornneam, Akrachai; Duong, Tang Van; Korost, Dmitriy V; Che, Jing

2018-05-18

We report on the discovery of a new genus of microhylid subfamily Asterophryinae from northern and eastern Indochina, containing three new species. Vietnamophryne Gen. nov. are secretive miniaturized frogs (SVL<21 mm) with a mostly semi-fossorial lifestyle. To assess phylogenetic relationships, we studied 12S rRNA-16S rRNA mtDNA fragments with a final alignment of 2 591 bp for 53 microhylid species. External morphology characters and osteological characteristics analyzed using micro-CT scanning were used for describing the new genus. Results of phylogenetic analyses assigned the new genus into the mainly Australasian subfamily Asterophryinae as a sister taxon to the genus Siamophryne from southern Indochina. The three specimens collected from Gia Lai Province in central Vietnam, Cao Bang Province in northern Vietnam, and Chiang Rai Province in northern Thailand proved to be separate species, different both in morphology and genetics (genetic divergence 3.1%≤P≤5.1%). Our work provides further evidence for the "out of Indo-Eurasia" scenario for Asterophryinae, indicating that the initial cladogenesis and differentiation of this group of frogs occurred in the Indochina Peninsula. To date, each of the three new species of Vietnamophryne Gen. nov. is known only from a single specimen; thus, their distribution, life history, and conservation status require further study.

Nailfold capillary patterns in healthy subjects: a real issue in capillaroscopy.

PubMed

Ingegnoli, Francesca; Gualtierotti, Roberta; Lubatti, Chiara; Bertolazzi, Chiara; Gutierrez, Marwin; Boracchi, Patrizia; Fornili, Marco; De Angelis, Rossella

2013-11-01

Nailfold capillaroscopy has been extensively applied in a broad spectrum of pathologic conditions, but very few data have been published in healthy individuals. The aim of this study was to describe the nailfold capillary findings on a large series of healthy subjects using the video-capillaroscopy technique. Nailfold capillaries were studied based on their morphology, dimensions and density. Then, to evaluate jointly the association between different capillary findings in groups of subjects which were homogeneous for their characteristics, cluster analysis was performed. The results (median) of capillary measurements were as follows: loop length 207μm, external diameter 39μm, internal diameter 17μm, apical diameter 17μm, and intercapillary distance 143μm. Based on the cluster analysis three major "normal" morphologic capillaroscopic patterns were depicted: 1) the "normal" pattern mainly with 2 to 5 U-shaped loops/mm and ≤2 tortuous loops/mm; 2) the "perfect normal" pattern with ≥5 U-shaped loops/mm and 3) the "unusual normal" with at least 1 meandering or bushy loop, or at least 1 microhemorrhage, or with >4 crossed loops/mm. Regarding the loop measurements, the majority of subjects had a median of 7capillaries/mm with a median length of 198μm. © 2013 Elsevier Inc. All rights reserved.

A novel bio-safe phase separation process for preparing open-pore biodegradable polycaprolactone microparticles.

PubMed

Salerno, Aurelio; Domingo, Concepción

2014-09-01

Open-pore biodegradable microparticles are object of considerable interest for biomedical applications, particularly as cell and drug delivery carriers in tissue engineering and health care treatments. Furthermore, the engineering of microparticles with well definite size distribution and pore architecture by bio-safe fabrication routes is crucial to avoid the use of toxic compounds potentially harmful to cells and biological tissues. To achieve this important issue, in the present study a straightforward and bio-safe approach for fabricating porous biodegradable microparticles with controlled morphological and structural features down to the nanometer scale is developed. In particular, ethyl lactate is used as a non-toxic solvent for polycaprolactone particles fabrication via a thermal induced phase separation technique. The used approach allows achieving open-pore particles with mean particle size in the 150-250 μm range and a 3.5-7.9 m(2)/g specific surface area. Finally, the combination of thermal induced phase separation and porogen leaching techniques is employed for the first time to obtain multi-scaled porous microparticles with large external and internal pore sizes and potential improved characteristics for cell culture and tissue engineering. Samples were characterized to assess their thermal properties, morphology and crystalline structure features and textural properties. Copyright © 2014 Elsevier B.V. All rights reserved.

Molar crown inner structural organization in Javanese Homo erectus.

PubMed

Zanolli, Clément

2015-01-01

This contribution investigates the inner organizational pattern (tooth tissue proportions and enamel-dentine junction morphology) of seven Homo erectus permanent molar crowns from the late Lower-early Middle Pleistocene Kabuh Formation of the Sangiran Dome (Central Java, Indonesia). The previous study of their external characteristics confirmed the degree of time-related structural reduction occurred in Javanese H. erectus, and also revealed a combination of nonmetric features which are rare in the Lower and early Middle Pleistocene dental record, but more frequently found in recent humans. In accordance with their outer occlusal morphology, the specimens exhibit a set of derived internal features, such as thick to hyperthick enamel, an incomplete expression of the crest patterns at the enamel-dentine junction (EDJ) level, a sharp EDJ topography. As a whole, these features differ from those expressed in some penecontemporaneous specimens/samples representing African H. erectus/ergaster and H. heidelbergensis, as well as in Neanderthals, but occur in recent human populations. Further research in virtual dental paleoanthropology to be developed at macroregional scale would clarify the polarity and intensity of the intermittent exchanges between continental and insular Southeast Asia around the Lower to Middle Pleistocene boundary, as well as should shed light on the still poorly understood longitudinal evolutionary dynamics across continental Asia. © 2014 Wiley Periodicals, Inc.

[The morphological characteristic of the skin lesions inflicted by plastic knives with four cutting edges].

PubMed

Leonov, S V; Finkel'shtein, V T

2015-01-01

The objective of the present work was to study the morphological features of the skin lesions inflicted by the blades of the Fgx Boot Blade I knives having four cutting edges. The study revealed the signs that can be used to distinguish between morphological characteristics of the stab and lacerated wounds having the primary and secondary incisions made by the four-edge blade.

Global morphological analysis of marine viruses shows minimal regional variation and dominance of non-tailed viruses.

PubMed

Brum, Jennifer R; Schenck, Ryan O; Sullivan, Matthew B

2013-09-01

Viruses influence oceanic ecosystems by causing mortality of microorganisms, altering nutrient and organic matter flux via lysis and auxiliary metabolic gene expression and changing the trajectory of microbial evolution through horizontal gene transfer. Limited host range and differing genetic potential of individual virus types mean that investigations into the types of viruses that exist in the ocean and their spatial distribution throughout the world's oceans are critical to understanding the global impacts of marine viruses. Here we evaluate viral morphological characteristics (morphotype, capsid diameter and tail length) using a quantitative transmission electron microscopy (qTEM) method across six of the world's oceans and seas sampled through the Tara Oceans Expedition. Extensive experimental validation of the qTEM method shows that neither sample preservation nor preparation significantly alters natural viral morphological characteristics. The global sampling analysis demonstrated that morphological characteristics did not vary consistently with depth (surface versus deep chlorophyll maximum waters) or oceanic region. Instead, temperature, salinity and oxygen concentration, but not chlorophyll a concentration, were more explanatory in evaluating differences in viral assemblage morphological characteristics. Surprisingly, given that the majority of cultivated bacterial viruses are tailed, non-tailed viruses appear to numerically dominate the upper oceans as they comprised 51-92% of the viral particles observed. Together, these results document global marine viral morphological characteristics, show that their minimal variability is more explained by environmental conditions than geography and suggest that non-tailed viruses might represent the most ecologically important targets for future research.

Variations in leopard cat (Prionailurus bengalensis) skull morphology and body size: sexual and geographic influences

PubMed Central

Oliveira, Luiz Flamarion B.

2015-01-01

The leopard cat, Prionailurus bengalensis (Kerr, 1792), is one of the most widespread Asian cats, occurring in continental eastern and southeastern Asia. Since 1929, several studies have focused on the morphology, ecology, and taxonomy of leopard cats. Nevertheless, hitherto there has been no agreement on basic aspects of leopard cat biology, such as the presence or absence of sexual dimorphism, morphological skull and body differences between the eleven recognized subspecies, and the biogeography of the different morphotypes. Twenty measurements on 25 adult leopard cat skulls from different Asian localities were analyzed through univariate and multivariate statistical approaches. Skull and external body measurements from studies over the last 77 years were assembled and organized in two categories: full data and summary data. Most of this database comprises small samples, which have never been statistically tested and compared with each other. Full data sets were tested with univariate and multivariate statistical analyses; summary data sets (i.e., means, SDs, and ranges) were analyzed through suitable univariate approaches. The independent analyses of the data from these works confirmed our original results and improved the overview of sexual dimorphism and geographical morphological variation among subspecies. Continental leopard cats have larger skulls and body dimensions. Skulls of Indochinese morphotypes have broader and higher features than those of continental morphotypes, while individuals from the Sunda Islands have skulls with comparatively narrow and low profiles. Cranial sexual dimorphism is present in different degrees among subspecies. Most display subtle sex-related variations in a few skull features. However, in some cases, sexual dimorphism in skull morphology is absent, such as in P. b. sumatranus and P. b. borneoensis. External body measurement comparisons also indicate the low degree of sexual dimorphism. Apart from the gonads, the longer hind foot of male leopard cats is the main feature of sexual dimorphism among P. b. bengalensis (and probably among P. b. horsfieldii too). External body measurements also indicated the absence of sexual dimorphism among individuals of P. b. borneoensis. Inter-subspecific skull comparisons provided a morphometric basis for differentiating some subspecies. Prionailurus b. horsfieldii and P. b. bengalensis were distinguished only by a subtle difference in PM4 size, indicating that overall skull morphology does not appear to support their separate taxonomical status, in spite of the marked differences reported in their coat patterns. Geological events affecting the Sunda Shelf connection between the Sunda Islands and the mainland during the Last Glacial Maximum seem to have influenced directly the morphological pattern shown by leopard cat subspecies nowadays. PMID:26500818

10 CFR 72.92 - Design basis external natural events.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 10 Energy 2 2013-01-01 2013-01-01 false Design basis external natural events. 72.92 Section 72.92... Evaluation Factors § 72.92 Design basis external natural events. (a) Natural phenomena that may exist or that... must be adopted for evaluating the design basis external natural events based on the characteristics of...

10 CFR 72.92 - Design basis external natural events.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 10 Energy 2 2014-01-01 2014-01-01 false Design basis external natural events. 72.92 Section 72.92... Evaluation Factors § 72.92 Design basis external natural events. (a) Natural phenomena that may exist or that... must be adopted for evaluating the design basis external natural events based on the characteristics of...

10 CFR 72.92 - Design basis external natural events.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 10 Energy 2 2012-01-01 2012-01-01 false Design basis external natural events. 72.92 Section 72.92... Evaluation Factors § 72.92 Design basis external natural events. (a) Natural phenomena that may exist or that... must be adopted for evaluating the design basis external natural events based on the characteristics of...

The mediational role of parenting on the longitudinal relation between child personality and externalizing behavior.

PubMed

Prinzie, Peter; van der Sluis, Cathy M; de Haan, Amaranta D; Deković, Maja

2010-08-01

Building on prior cross-sectional work, this longitudinal study evaluated the proposition that maternal and paternal overreactive and authoritative parenting mediates the effect of child personality characteristics on externalizing behavior. Data from the Flemish Study on Parenting, Personality, and Problem Behavior were used in a moderated mediation analysis (N=434). Teachers rated children's Big Five characteristics, fathers and mothers rated their parenting, and 3 years later, children rated their externalizing behavior. Mediational analysis revealed both direct and indirect effects. Higher levels of Extraversion and lower levels of Benevolence were related directly to higher levels of child externalizing behavior. Higher levels of paternal authoritative parenting and lower levels of maternal overreactivity were related to lower scores on externalizing behavior. In addition, the relation between Benevolence, Emotional Stability, and externalizing behavior was partially mediated by parental overreactivity. Conscientiousness had an indirect effect on externalizing behavior through paternal authoritative parenting. Relations were not moderated by child gender. This study is of theoretical interest because the results demonstrate that parenting is a mediating mechanism that accounts for associations between personality and externalizing behavior.

Parenting and Children's Adjustment Problems: The Mediating Role of Self-Esteem and Peer Relations

ERIC Educational Resources Information Center

Georgiou, Nicos A.; Stavrinides, Panayiotis; Georgiou, Stelios

2016-01-01

The aim of this study was to investigate the impact of parental and personal characteristics on children's internalizing/externalizing problems. Further, this study aimed to examine personal characteristics (self-esteem, peer relations) as mediators in the relation between parenting and internalizing/externalizing problems. In order to address…

Intervening Processes in the Relationship between Neighborhood Characteristics and Psychological Symptoms in Urban Youth

ERIC Educational Resources Information Center

Katz, Brian N.; Esparza, Patricia; Carter, Jocelyn Smith; Grant, Kathryn E.; Meyerson, David A.

2012-01-01

The present study tested for mediators of the relation between neighborhood risk characteristics and internalizing and externalizing symptoms in a sample of 1,120 low-income urban adolescents. Results indicate that a composite of census tract variables predicted both internalizing and externalizing symptoms in this sample. Stressful life events…

A new species of Chiasmocleis (Microhylidae, Gastrophryninae) from the Atlantic Forest of Espírito Santo State, Brazil

PubMed Central

Tonini, João F. R.; Forlani, Maurício C.; de Sá, Rafael O.

2014-01-01

Abstract Among Neotropical microhylids, the genus Chiasmocleis is exceptionally diverse. Most species of Chiasmocleis were described in recent years based on external morphology, but recent studies using molecular data did not support the monophyly of the species groups clustered based on feet webbing. Furthermore, a phylogeographic study of C. lacrimae estimated high genetic divergence and low gene flow among populations across small geographic ranges. Increasing the molecular and geographic sampling, and incorporating morphological data, we identified new cryptic species. Herein, we used novel genetic and morphological data to describe a new species of Chiasmocleis. PMID:25161370

Computer simulations of structural transitions in large ferrofluid aggregates

NASA Astrophysics Data System (ADS)

Yoon, Mina; Tomanek, David

2003-03-01

We have developed a quaternion molecular dynamics formalism to study structural transitions in systems of ferrofluid particles in colloidal suspensions. Our approach takes advantage of the viscous damping provided by the surrounding liquid and enables us to study the time evolution of these systems over milli-second time periods as a function of the number of particles, initial geometry, and an externally applied magnetic field. Our computer simulations for aggregates containing tens to hundreds of ferrofluid particles suggest that these systems relax to the global optimum structure in a step-wise manner. During the relaxation process, the potential energy decreases by two mechanisms, which occur on different time scales. Short time periods associated with structural relaxations within a given morphology are followed by much slower processes that generally lead to a simpler morphology. We discuss possible applications of these externally driven structural transitions for targeted medication delivery.

Knee Moment-Angle Characteristics and Semitendinosus Muscle Morphology in Children with Spastic Paresis Selected for Medial Hamstring Lengthening

PubMed Central

Haberfehlner, Helga; Jaspers, Richard T.; Rutz, Erich; Becher, Jules G.; Harlaar, Jaap; van der Sluijs, Johannes A.; Witbreuk, Melinda M.; Romkes, Jacqueline; Freslier, Marie; Brunner, Reinald

2016-01-01

To increase knee range of motion and improve gait in children with spastic paresis (SP), the semitendinosus muscle (ST) amongst other hamstring muscles is frequently lengthened by surgery, but with variable success. Little is known about how the pre-surgical mechanical and morphological characteristics of ST muscle differ between children with SP and typically developing children (TD). The aims of this study were to assess (1) how knee moment-angle characteristics and ST morphology in children with SP selected for medial hamstring lengthening differ from TD children, as well as (2) how knee moment-angle characteristics and ST morphology are related. In nine SP and nine TD children, passive knee moment-angle characteristics and morphology of ST (i.e. fascicle length, muscle belly length, tendon length, physiological cross-sectional area, and volume) were assessed by hand-held dynamometry and freehand 3D ultrasound, respectively. At net knee flexion moments above 0.5 Nm, more flexed knee angles were found for SP compared to TD children. The measured knee angle range between 0 and 4 Nm was 30% smaller in children with SP. Muscle volume, physiological cross-sectional area, and fascicle length normalized to femur length were smaller in SP compared to TD children (62%, 48%, and 18%, respectively). Sixty percent of the variation in knee angles at 4 Nm net knee moment was explained by ST fascicle length. Altered knee moment-angle characteristics indicate an increased ST stiffness in SP children. Morphological observations indicate that in SP children planned for medial hamstring lengthening, the longitudinal and cross-sectional growth of ST muscle fibers is reduced. The reduced fascicle length can partly explain the increased ST stiffness and, hence, a more flexed knee joint in these SP children. PMID:27861523

Knee Moment-Angle Characteristics and Semitendinosus Muscle Morphology in Children with Spastic Paresis Selected for Medial Hamstring Lengthening.

PubMed

Haberfehlner, Helga; Jaspers, Richard T; Rutz, Erich; Becher, Jules G; Harlaar, Jaap; van der Sluijs, Johannes A; Witbreuk, Melinda M; Romkes, Jacqueline; Freslier, Marie; Brunner, Reinald; Maas, Huub; Buizer, Annemieke I

2016-01-01

To increase knee range of motion and improve gait in children with spastic paresis (SP), the semitendinosus muscle (ST) amongst other hamstring muscles is frequently lengthened by surgery, but with variable success. Little is known about how the pre-surgical mechanical and morphological characteristics of ST muscle differ between children with SP and typically developing children (TD). The aims of this study were to assess (1) how knee moment-angle characteristics and ST morphology in children with SP selected for medial hamstring lengthening differ from TD children, as well as (2) how knee moment-angle characteristics and ST morphology are related. In nine SP and nine TD children, passive knee moment-angle characteristics and morphology of ST (i.e. fascicle length, muscle belly length, tendon length, physiological cross-sectional area, and volume) were assessed by hand-held dynamometry and freehand 3D ultrasound, respectively. At net knee flexion moments above 0.5 Nm, more flexed knee angles were found for SP compared to TD children. The measured knee angle range between 0 and 4 Nm was 30% smaller in children with SP. Muscle volume, physiological cross-sectional area, and fascicle length normalized to femur length were smaller in SP compared to TD children (62%, 48%, and 18%, respectively). Sixty percent of the variation in knee angles at 4 Nm net knee moment was explained by ST fascicle length. Altered knee moment-angle characteristics indicate an increased ST stiffness in SP children. Morphological observations indicate that in SP children planned for medial hamstring lengthening, the longitudinal and cross-sectional growth of ST muscle fibers is reduced. The reduced fascicle length can partly explain the increased ST stiffness and, hence, a more flexed knee joint in these SP children.

Surface morphology of taste buds in catfish barbels.

PubMed

Ovalle, W K; Shinn, S L

1977-03-16

External taste buds abound on barbels of the adult catfish Corydoras arcuatus. When examined by scanning electron microscopy, they are visualized as a series of punctate, conical elevations projecting from the general surface epithelium. All taste buds were found to be of one type. Both their external and internal surface features could be clearly elucidated on intact barbels and in barbels fractured transversely at various positions along their length. An extensive nerve terminal network penetrates the base of each taste bud. Two populations of elongated cells bearing prominent microvilli project through the central pore at the tip of each bud. One set of microvilli is thicker, longer and more club-shaped than its counterpart. While both are randomly distributed within each central pore, the small, short microvilli appear to outnumber the larger ones. A third population of cells, devoid of any apical microvilli, was also seen in some of the taste buds examined internally. These cells do not project to the external surface and are interpreted as "basal" cells described in previous light and transmission electron microscope studies of taste buds in other vertebrate species. The functional significance of some of these morphological findings is discussed.

The HI Chronicles of LITTLE THINGS BCDs: VII Zw 403’s External Gas Cloud

NASA Astrophysics Data System (ADS)

Ashley, Trisha L.; Simpson, Caroline E.; Elmegreen, Bruce; Johnson, Megan C.; Pokhrel, Nau Raj

2017-01-01

Blue compact dwarf (BCD) galaxies are characterized by their concentrated bursts of star formation. Yet, for many BCDs, it is unclear what has triggered this activity. VII Zw 403 is a well-known BCD that is relatively isolated from other galaxies. Using the high angular and velocity resolution Very Large Array (VLA) atomic hydrogen (HI) data from the LITTLE THINGS1 survey, we study the detailed kinematics and morphology of VII Zw 403’s HI gas. High sensitivity HI Green Bank Telescope (GBT) observations were also used to search the surrounding area for companion galaxies and extended HI emission, but they did not result in detections of either. The VLA data show a kinematically and morphologically disturbed HI disk. From the VLA HI data cubes, we have separated out most of the emission from what is likely an external gas cloud that is in the line of sight of the HI disk. This external gas cloud appears to be accreting onto the disk and could trigger a future burst of star formation. 1Local Irregulars That Trace Luminosity Extremes, The HI Nearby Galaxy Survey; https://science.nrao.edu/science/surveys/ littlethings

Identification of cytolytic vaginosis versus vulvovaginal candidiasis.

PubMed

Hu, Zhengqiang; Zhou, Wei; Mu, Liyuan; Kuang, Linghan; Su, Min; Jiang, Yongmei

2015-04-01

This study aimed to observe the morphological characteristic of vaginal discharge in patients with cytolytic vaginosis (CV) under the microscope and to identify it in patients with CV and in patients with vulvovaginal candidiasis (VVC). A total of 108 subjects including 21 healthy women, 33 patients with CV, and 54 patients with VVC were enrolled in the present morphological study. Vaginal discharge was collected and made into smear. The morphological characteristics of these vaginal smears with Gram staining were observed under the microscope. The smears were assessed for the quantity of lactobacilli, epithelial cell morphology, and the absence or presence of Candida species, Trichomonas vaginalis, and clue sells. First, the age, the level of education, and especially the status of pregnancy of patients with CV were significantly different from those of the patients with VVC. Second, the morphological characteristics of patients with CV consisted of overgrowth of lactobacilli, the presence of naked nuclei and fragments of the epithelial cells, a paucity of leukocytes, and the absence of Candida species and other pathogens. However, the morphological characteristic of patients with VVC consisted of the presence or absence of lactobacilli and the presence of normal epithelial cells, candidal spores, blastospores, hyphae, or other pathogens such as T. vaginalis and Gardnerella vaginalis. Both CV and VVC can be identified based on the quantity of lactobacilli, the morphology of the epithelial cells, and the absence or presence of Candida species and other pathogens, and the misdiagnosis of CV as VVC can be avoided.

Systematics of the endangered toad genus Andinophryne (Anura: Bufonidae): phylogenetic position and synonymy under the genus Rhaebo.

PubMed

Ron, Santiago R; Mueses-Cisneros, Jonh Jairo; Gutiérrez-Cárdenas, Paul David Alfonso; Rojas-Rivera, Alejandra; Lynch, Ryan L; Rocha, Carlos F Duarte; Galarza, Gabriela

2015-04-16

Bufonidae is one of the most diverse amphibian families. Its large-scale phylogenetic relationships are relatively well understood with the exception of few Neotropical genera that may have diverged early in the evolution of the family. One of those genera is Andinophryne, a poorly known group of three toad species distributed in the western slopes of the Andes of northern Ecuador and southern Colombia. Their phylogenetic position is unknown due to lack of genetic data. We estimated a new phylogeny (over 200 species) of the family Bufonidae based on DNA sequences of mitochondrial and nuclear genes to assess the phylogenetic position of Andinophryne based on recently collected specimens of A. colomai and A. olallai from Ecuador and Colombia. We also examined external and internal morphology of Andinophryne to explore its congruence with the new phylogeny. The mtDNA and nuclear phylogenies show that Andinophryne is embedded within Rhaebo, a genus that belongs to a large clade characterized by the presence parotoid glands. Morphological characters confirmed the affinity of Andinophryne to Rhaebo and a close relationship between Andinophryne colomai and Andinophryne olallai. Rhaebo was paraphyletic relative to Andinophryne and to solve this problem we synonymize Andinophryne under Rhaebo. We discuss putative morphological synapomorphies for Rhaebo including Andinophryne. We provide species accounts for R. atelopoides new comb., R. colomai new comb. and R. olallai new comb. including assessments of their conservation status. We suggest that the three species are Critically Endangered. Their altitudinal distribution and association with streams are characteristic of endangered Andean amphibians.

Ecological and morphological profile of floating spherical Cladophora socialis aggregations in central Thailand.

PubMed

Tsutsui, Isao; Miyoshi, Tatsuo; Sukchai, Halethichanok; Pinphoo, Piyarat; Aue-Umneoy, Dusit; Meeanan, Chonlada; Songphatkaew, Jaruwan; Klomkling, Sirimas; Yamaguchi, Iori; Ganmanee, Monthon; Sudo, Hiroyuki; Hamano, Kaoru

2015-01-01

The unique beauty of spherical aggregation forming algae has attracted much attention from both the scientific and lay communities. Several aegagropilous seaweeds have been identified to date, including the plants of genus Cladophora and Chaetomorpha. However, this phenomenon remains poorly understood. In July 2013, a mass occurrence of spherical Cladophora aggregations was observed in a salt field reservoir in Central Thailand. The aims of the present study were to describe the habitat of the spherical aggregations and confirm the species. We performed a field survey, internal and external morphological observations, pyrenoid ultrastructure observations, and molecular sequence analysis. Floating spherical Cladophora aggregations (1-8 cm in diameter) were observed in an area ~560 m2, on the downwind side of the reservoir where there was water movement. Individual filaments in the aggregations were entangled in each other; consequently, branches growing in different directions were observed within a clump. We suggest that water movement and morphological characteristics promote the formation of spherical aggregations in this species. The molecular sequencing results revealed that the study species was highly homologous to both C. socialis and C. coelothrix. However, the diameter of the apical cells in the study species was less than that of C. coelothrix. The pyrenoid ultrastructure was more consistent with that of C. socialis. We conclude that the study species is C. socialis. This first record of spherical aggregations in this species advances our understanding of these formations. However, further detailed physical measurements are required to fully elucidate the mechanism behind these spherical formations.

Ecological and Morphological Profile of Floating Spherical Cladophora socialis Aggregations in Central Thailand

PubMed Central

Tsutsui, Isao; Miyoshi, Tatsuo; Sukchai, Halethichanok; Pinphoo, Piyarat; Aue-umneoy, Dusit; Meeanan, Chonlada; Songphatkaew, Jaruwan; Klomkling, Sirimas; Yamaguchi, Iori; Ganmanee, Monthon; Sudo, Hiroyuki; Hamano, Kaoru

2015-01-01

The unique beauty of spherical aggregation forming algae has attracted much attention from both the scientific and lay communities. Several aegagropilous seaweeds have been identified to date, including the plants of genus Cladophora and Chaetomorpha. However, this phenomenon remains poorly understood. In July 2013, a mass occurrence of spherical Cladophora aggregations was observed in a salt field reservoir in Central Thailand. The aims of the present study were to describe the habitat of the spherical aggregations and confirm the species. We performed a field survey, internal and external morphological observations, pyrenoid ultrastructure observations, and molecular sequence analysis. Floating spherical Cladophora aggregations (1–8 cm in diameter) were observed in an area ~560 m2, on the downwind side of the reservoir where there was water movement. Individual filaments in the aggregations were entangled in each other; consequently, branches growing in different directions were observed within a clump. We suggest that water movement and morphological characteristics promote the formation of spherical aggregations in this species. The molecular sequencing results revealed that the study species was highly homologous to both C. socialis and C. coelothrix. However, the diameter of the apical cells in the study species was less than that of C. coelothrix. The pyrenoid ultrastructure was more consistent with that of C. socialis. We conclude that the study species is C. socialis. This first record of spherical aggregations in this species advances our understanding of these formations. However, further detailed physical measurements are required to fully elucidate the mechanism behind these spherical formations. PMID:25898393

Why small males have big sperm: dimorphic squid sperm linked to alternative mating behaviours

PubMed Central

2011-01-01

Background Sperm cells are the target of strong sexual selection that may drive changes in sperm structure and function to maximize fertilisation success. Sperm evolution is regarded to be one of the major consequences of sperm competition in polyandrous species, however it can also be driven by adaptation to the environmental conditions at the site of fertilization. Strong stabilizing selection limits intra-specific variation, and therefore polymorphism, among fertile sperm (eusperm). Here we analyzed reproductive morphology differences among males employing characteristic alternative mating behaviours, and so potentially different conditions of sperm competition and fertilization environment, in the squid Loligo bleekeri. Results Large consort males transfer smaller (average total length = 73 μm) sperm to a female's internal sperm storage location, inside the oviduct; whereas small sneaker males transfer larger (99 μm) sperm to an external location around the seminal receptacle near the mouth. No significant difference in swimming speed was observed between consort and sneaker sperm. Furthermore, sperm precedence in the seminal receptacle was not biased toward longer sperm, suggesting no evidence for large sperm being favoured in competition for space in the sperm storage organ among sneaker males. Conclusions Here we report the first case, in the squid Loligo bleekeri, where distinctly dimorphic eusperm are produced by different sized males that employ alternative mating behaviours. Our results found no evidence that the distinct sperm dimorphism was driven by between- and within-tactic sperm competition. We propose that presence of alternative fertilization environments with distinct characteristics (i.e. internal or external), whether or not in combination with the effects of sperm competition, can drive the disruptive evolution of sperm size. PMID:21831296

Why small males have big sperm: dimorphic squid sperm linked to alternative mating behaviours.

PubMed

Iwata, Yoko; Shaw, Paul; Fujiwara, Eiji; Shiba, Kogiku; Kakiuchi, Yasutaka; Hirohashi, Noritaka

2011-08-10

Sperm cells are the target of strong sexual selection that may drive changes in sperm structure and function to maximize fertilisation success. Sperm evolution is regarded to be one of the major consequences of sperm competition in polyandrous species, however it can also be driven by adaptation to the environmental conditions at the site of fertilization. Strong stabilizing selection limits intra-specific variation, and therefore polymorphism, among fertile sperm (eusperm). Here we analyzed reproductive morphology differences among males employing characteristic alternative mating behaviours, and so potentially different conditions of sperm competition and fertilization environment, in the squid Loligo bleekeri. Large consort males transfer smaller (average total length = 73 μm) sperm to a female's internal sperm storage location, inside the oviduct; whereas small sneaker males transfer larger (99 μm) sperm to an external location around the seminal receptacle near the mouth. No significant difference in swimming speed was observed between consort and sneaker sperm. Furthermore, sperm precedence in the seminal receptacle was not biased toward longer sperm, suggesting no evidence for large sperm being favoured in competition for space in the sperm storage organ among sneaker males. Here we report the first case, in the squid Loligo bleekeri, where distinctly dimorphic eusperm are produced by different sized males that employ alternative mating behaviours. Our results found no evidence that the distinct sperm dimorphism was driven by between- and within-tactic sperm competition. We propose that presence of alternative fertilization environments with distinct characteristics (i.e. internal or external), whether or not in combination with the effects of sperm competition, can drive the disruptive evolution of sperm size.

Characterization of orange oil microcapsules for application in textiles

NASA Astrophysics Data System (ADS)

Rossi, W.; Bonet-Aracil, M.; Bou-Belda, E.; Gisbert-Payá, J.; Wilson, K.; Roldo, L.

2017-10-01

The use of orange oil presents as an ecological alternative to chemicals, attracting the attention of the scientific community to the development of eco-friendly antimicrobials. The microencapsulation technology has been used for the application of orange oil to textiles, being an economically viable, fast and efficient method by combining core and shell materials, desirable perceptual and functional characteristics, responsible for properties related to the nature of the product and provides that the wall materials release the functional substances in a controlled manner, in addition to effectively protecting and isolating the core material from the external environment to prevent its volatilization and deterioration, increasing the stability of the oil, such as non-toxicity. Thus, to better exploit the properties of the orange essential oil applied to textile products this study presents a characterization of microcapsules of Melamine formaldehyde obtained by the interfacial polymerization method with variations of proportions of orange oil (volatile) with fixed oil Medium-Chain Triglycerides (MCT) (non-volatile) to assist in the stability of the orange essential oil. Scanning electron microscope (SEM) was used as visualizing tool to characterize microparticles and surface morphology and thermal characteristics of microcapsules were premeditated by mean Differential scanning calorimetry (DSC).

A comparison of the morphological and physiochemical characteristics of 14 carambola cultivars

USDA-ARS?s Scientific Manuscript database

A variety trial of 14 different carambola (Averrhoa carambola, L.) cultivars was conducted at the National Germplasm Repository, Subtropical Horticultural Research Station in Miami, FL. The study compared the morphological and physicochemical characteristics of 14 carambola varieties grown at the re...

Anorectal function and morphology in patients with sporadic proctalgia fugax.

PubMed

Eckardt, V F; Dodt, O; Kanzler, G; Bernhard, G

1996-07-01

The pathophysiology of sporadic proctalgia fugax remains unknown. This study investigates whether patients with this syndrome exhibit alterations in anal function and morphology. Eighteen patients with sporadic proctalgia fugax and 18 sex-matched and age-matched healthy controls were studied. Manometric studies investigated anal resting and squeeze pressures, the rectoanal inhibitory reflex, rectal compliance, and smooth muscle response to edrophonium chloride administration. External and internal sphincter thickness was measured endosonographically. Patients had slightly higher (P = 0.0291) anal resting pressures (65.5 +/- 11.4 mmHg) than controls (56 +/- 9.9 mmHg). However, anal squeeze pressure, sphincter relaxation during rectal distention, and rectal compliance were similar in both groups, and no alterations were detected in external and internal anal sphincter thickness. Edrophonium chloride administration was followed by sharp postrelaxation contractions in two patients, whereas anal function remained unaltered in controls. Acute episodes of proctalgia, which occurred in two patients while under study, were associated with a rise in anal resting tone and an increase in slow wave amplitude. In the resting state, patients with proctalgia fugax have normal anorectal function and morphology. However, they may exhibit a motor abnormality of the anal smooth muscle during an acute attack.

Effect of Different Coating Materials on The Characteristics Of Chlorophyll Microcapsules from Caulerpa racemosa

NASA Astrophysics Data System (ADS)

Kurniasih, R. A.; Dewi, E. N.; Purnamayati, L.

2018-02-01

The sea grape (Caulerpa racemosa) has a chlorophyll pigment that can be extracted using a non-polar solvent. Chlorophyll as a natural dye has unstable characteristics of temperature, pH, and light. Microencapsulation by the freeze-drying method can be used to protect chlorophyll from degradation caused by external influences where the type of coating material can affect the characteristics of the chlorophyll microcapsules. The objective of this study was to determine the characteristics of chlorophyll microcapsules with various types of coating material. Chlorophyll was microencapsulated using maltodextrin (CM), maltodextrin-alginate (CMA), and maltodextrin-fish gelatin (CMG). Chlorophyll encapsulated with maltodextrin-alginate resulting in the highest yield. The results of FTIR analysis indicated the presence of following functional groups in chlorophyll microcapsules viz., inter- and intra-molecular bonded alcohol OH, C = N stretching imine/oxime or C = O stretching conjugated ketone or alkenes, OH phenol, and CN stretching amine. CM had a particle size between 9,061 - 469.9 nm, CMA between 9,707 - 363.5 nm, and CMG between 11.49 - 433.2 nm. Based on the observation of morphology by using SEM, it showed that the all of the chlorophyll microcapsules were in the form of flake shape and porous. CM and CMA looked more fragile than CMG it can be seen from the cracks in some parts of CM and CMA. Therefore, CMG release time was longer than CM and CMA.

Factors affecting metabolic cost of transport during a multi-stage running race.

PubMed

Lazzer, Stefano; Taboga, Paolo; Salvadego, Desy; Rejc, Enrico; Simunic, Bostjan; Narici, Marco V; Buglione, Antonio; Giovanelli, Nicola; Antonutto, Guglielmo; Grassi, Bruno; Pisot, Rado; di Prampero, Pietro E

2014-03-01

The aim of this study was to investigate: (1) the role of , the fraction of (F) and the metabolic cost of transport (CoT) in determining performance during an ultra-endurance competition and (2) the effects of the race on several biomechanical and morphological parameters of the lower limbs that are likely to affect CoT. Eleven runners (aged 29-54 years) participated in an ultra-endurance competition consisting of three running stages of 25, 55 and 13 km on three consecutive days. Anthropometric characteristics, body composition, morphological properties of the gastrocnemius medialis, maximal explosive power of the lower limb and were determined before the competition. In addition, biomechanics of running and CoT were determined, before and immediately after each running stage. Performance was directly proportional to (r=0.77) and F (r=0.36), and inversely proportional to CoT (r=-0.30). Low CoT values were significantly related to high maximal power of the lower limbs (r=-0.74) and vertical stiffness (r=-0.65) and low footprint index (FPI, r=0.70), step frequency (r=0.62) and external work (r=0.60). About 50% of the increase in CoT during the stages of the competition was accounted for by changes in FPI, which represents a global evaluation of medio-lateral displacement of the foot during the whole stance phase, which in turn is associated with the myotendinous characteristics of the lower limb. Thus, lower CoT values were related to greater muscular power and lower FPI, suggesting that a better ankle stability is likely to achieve better performance in an ultra-endurance running competition.

H-ATLAS/GAMA: the nature and characteristics of optically red galaxies detected at submillimetre wavelengths

NASA Astrophysics Data System (ADS)

Dariush, A.; Dib, S.; Hony, S.; Smith, D. J. B.; Zhukovska, S.; Dunne, L.; Eales, S.; Andrae, E.; Baes, M.; Baldry, I.; Bauer, A.; Bland-Hawthorn, J.; Brough, S.; Bourne, N.; Cava, A.; Clements, D.; Cluver, M.; Cooray, A.; De Zotti, G.; Driver, S.; Grootes, M. W.; Hopkins, A. M.; Hopwood, R.; Kaviraj, S.; Kelvin, L.; Lara-Lopez, M. A.; Liske, J.; Loveday, J.; Maddox, S.; Madore, B.; Michałowski, M. J.; Pearson, C.; Popescu, C.; Robotham, A.; Rowlands, K.; Seibert, M.; Shabani, F.; Smith, M. W. L.; Taylor, E. N.; Tuffs, R.; Valiante, E.; Virdee, J. S.

2016-02-01

We combine Herschel/SPIRE submillimetre (submm) observations with existing multiwavelength data to investigate the characteristics of low-redshift, optically red galaxies detected in submm bands. We select a sample of galaxies in the redshift range 0.01 ≤ z ≤ 0.2, having >5σ detections in the SPIRE 250 μm submm waveband. Sources are then divided into two sub-samples of red and blue galaxies, based on their UV-optical colours. Galaxies in the red sample account for ≈4.2 per cent of the total number of sources with stellar masses M* ≳ 1010 M⊙. Following visual classification of the red galaxies, we find that ≳30 per cent of them are early-type galaxies and ≳40 per cent are spirals. The colour of the red-spiral galaxies could be the result of their highly inclined orientation and/or a strong contribution of the old stellar population. It is found that irrespective of their morphological types, red and blue sources occupy environments with more or less similar densities (I.e. the Σ5 parameter). From the analysis of the spectral energy distributions of galaxies in our samples based on MAGPHYS, we find that galaxies in the red sample (of any morphological type) have dust masses similar to those in the blue sample (I.e. normal spiral/star-forming systems). However, in comparison to the red-spirals and in particular blue systems, red-ellipticals have lower mean dust-to-stellar mass ratios. Besides galaxies in the red-elliptical sample have much lower mean star formation/specific star formation rates in contrast to their counterparts in the blue sample. Our results support a scenario where dust in early-type systems is likely to be of an external origin.

Mammalian species - Neotoma magister

Treesearch

Steven B. Castleberry; Michael T. Mengak; W. Mark Ford

2006-01-01

External morphology of N. magister (Fig. 1) is similar to that of N. floridana, the only parapatric Neotoma. Although N. magister generally is larger in mass and with longer vibrissae, identification based on single measurements is unreliable because of morphometric overlap (Ray 2000)....

Morphology, cultural characteristics, and pathogenicity of Rhizosphaera kalkhoffii on Picea spp. in northern Minnesota and Wisconsin

Treesearch

Jennifer Juzwik

1993-01-01

Morphology, cultural characteristics, and pathogenicity of Rhizosphaera kalkhoffii from spruce (Picea spp.) showing premature needle loss in northern Minnesota and Wisconsin were investigated. Pycnidiospores from needles, conidia of the Hormonema-like synanamorph, and pycnidiospores produced in culture were...

[Morphological, optical, and structural characteristics of glass sponge spicules and the photoreceptor hypothesis of their survival].

PubMed

Voznesenskiĭ, S S; Kul'chin, Iu N; Galkina, A N; Sergeev, A A

2010-01-01

The morphology, structure, and optical characteristics of spicules of some sea glass sponges have been studied. The results obtained are interpreted from the point of view of their possible role in the survival of the organism of sponges.

Human tooth and root canal morphology reconstruction using magnetic resonance imaging.

PubMed

Drăgan, Oana Carmen; Fărcăşanu, Alexandru Ştefan; Câmpian, Radu Septimiu; Turcu, Romulus Valeriu Flaviu

2016-01-01

Visualization of the internal and external root canal morphology is very important for a successful endodontic treatment; however, it seems to be difficult considering the small size of the tooth and the complexity of the root canal system. Film-based or digital conventional radiographic techniques as well as cone beam computed tomography provide limited information on the dental pulp anatomy or have harmful effects. A new non-invasive diagnosis tool is magnetic resonance imaging, due to its ability of imaging both hard and soft tissues. The aim of this study was to demonstrate magnetic resonance imaging to be a useful tool for imaging the anatomic conditions of the external and internal root canal morphology for endodontic purposes. The endodontic system of one freshly extracted wisdom tooth, chosen for its well-known anatomical variations, was mechanically shaped using a hybrid technique. After its preparation, the tooth was immersed into a recipient with saline solution and magnetic resonance imaged immediately. A Bruker Biospec magnetic resonance imaging scanner operated at 7.04 Tesla and based on Avance III radio frequency technology was used. InVesalius software was employed for the 3D reconstruction of the tooth scanned volume. The current ex-vivo experiment shows the accurate 3D volume rendered reconstruction of the internal and external morphology of a human extracted and endodontically treated tooth using a dataset of images acquired by magnetic resonance imaging. The external lingual and vestibular views of the tooth as well as the occlusal view of the pulp chamber, the access cavity, the distal canal opening on the pulp chamber floor, the coronal third of the root canals, the degree of root separation and the apical fusion of the two mesial roots, details of the apical region, root canal curvatures, furcal region and interradicular root grooves could be clearly bordered. Magnetic resonance imaging offers 3D image datasets with more information than the conventional radiographic techniques. Due to its ability of imaging both hard and soft dental tissues, magnetic resonance imaging can be successfully used as a 3D diagnostic imaging technique in dentistry. When choosing the imaging method, dental clinicians should weight the benefit-risk ratio, taking into account the costs associated to magnetic resonance imaging and the harmful effects of ionizing radiations when cone beam computed tomography or conventional x-ray are used.

A Monte Carlo-finite element model for strain energy controlled microstructural evolution - 'Rafting' in superalloys

NASA Technical Reports Server (NTRS)

Gayda, J.; Srolovitz, D. J.

1989-01-01

This paper presents a specialized microstructural lattice model, MCFET (Monte Carlo finite element technique), which simulates microstructural evolution in materials in which strain energy has an important role in determining morphology. The model is capable of accounting for externally applied stress, surface tension, misfit, elastic inhomogeneity, elastic anisotropy, and arbitrary temperatures. The MCFET analysis was found to compare well with the results of analytical calculations of the equilibrium morphologies of isolated particles in an infinite matrix.

Global morphological analysis of marine viruses shows minimal regional variation and dominance of non-tailed viruses

PubMed Central

Brum, Jennifer R; Schenck, Ryan O; Sullivan, Matthew B

2013-01-01

Viruses influence oceanic ecosystems by causing mortality of microorganisms, altering nutrient and organic matter flux via lysis and auxiliary metabolic gene expression and changing the trajectory of microbial evolution through horizontal gene transfer. Limited host range and differing genetic potential of individual virus types mean that investigations into the types of viruses that exist in the ocean and their spatial distribution throughout the world's oceans are critical to understanding the global impacts of marine viruses. Here we evaluate viral morphological characteristics (morphotype, capsid diameter and tail length) using a quantitative transmission electron microscopy (qTEM) method across six of the world's oceans and seas sampled through the Tara Oceans Expedition. Extensive experimental validation of the qTEM method shows that neither sample preservation nor preparation significantly alters natural viral morphological characteristics. The global sampling analysis demonstrated that morphological characteristics did not vary consistently with depth (surface versus deep chlorophyll maximum waters) or oceanic region. Instead, temperature, salinity and oxygen concentration, but not chlorophyll a concentration, were more explanatory in evaluating differences in viral assemblage morphological characteristics. Surprisingly, given that the majority of cultivated bacterial viruses are tailed, non-tailed viruses appear to numerically dominate the upper oceans as they comprised 51–92% of the viral particles observed. Together, these results document global marine viral morphological characteristics, show that their minimal variability is more explained by environmental conditions than geography and suggest that non-tailed viruses might represent the most ecologically important targets for future research. PMID:23635867

Externalizing Behavior Problems during Adolescence: An Ecological Perspective

ERIC Educational Resources Information Center

White, Rachel; Renk, Kimberly

2012-01-01

Given the ramifications of difficulties related to externalizing behavior problems, the present study examined the relationships among adolescents' externalizing behavior problems, characteristics of adolescents' families, their perceived neighborhood support, and their acculturation. As part of this study, a culturally diverse sample of…

Comparative descriptions of non-adult stages of four genera of Gordiids (Phylum: Nematomorpha).

PubMed

Szmygiel, Cleo; Schmidt-Rhaesa, Andreas; Hanelt, Ben; Bolek, Matthew G

2014-02-25

Freshwater hairworms infect terrestrial arthropods as larvae but are free-living in aquatic habitats as adults. Estimates suggest that only 18% of hairworm species have been described globally and biodiversity studies on this group have been hindered by unreliable ways of collecting adult free living worms over large geographical areas. However, recent work indicates that non-adult cyst stages of hairworms may be the most commonly encountered stages of gordiids in the environment, and can be used for discovering the hidden diversity of this group. Unfortunately, little information is available on the morphological characteristics of non-adult stages of hairworms. To address this problem, we describe and compare morphological characteristics of non-adult stages for nine species of African and North American gordiids from four genera (Chordodes, Gordius, Paragordius, and Neochordodes). Observations were made on the oviposition behavior of adult worms and morphological characteristics were recorded for egg strings, larvae and cysts using light and differential interference contrast microscopy and/or scanning electron microscopy. Our study indicates that three distinct types of oviposition behaviors and three distinct morphological types of egg string, larva, and cysts were present among the four genera of gordiids. Although species identification based on cyst characteristics was not always possible among different species of gordiids, cyst morphology was conserved among some genera and all clades of gordiids. More importantly, our work indicates that gordiid larval morphology can be used for predicting cyst morphology among other gordiid genera. The capability to identify and predict gordiid genera and/or clades based on cyst morphology will be useful for culturing gordiids in the laboratory from field collected cysts and these new techniques will undoubtedly allow others to discover new species of gordiids from around the world.

Treatment of displaced intra-articular calcaneal fractures with triangular tube-to-bar external fixation: long-term clinical follow-up and radiographic analysis.

PubMed

Roukis, Thomas S; Wünschel, Markus; Lutz, Hans-Peter; Kirschner, Peter; Zgonis, Thomas

2008-04-01

Sixty-six feet (62 patients) with displaced intra-articular calcaneal fractures underwent manual reduction and distraction with the use of a triangular tube-to-bar external fixation device and were retrospectively reviewed at a minimum of 1-year post-operative. Final radiographic follow-up revealed complete consolidation in all fractures, maintenance of reduction, and limited degenerative osteoarthrosis about the subtalar joint. Our results indicate that with proper application and attention to detail, restoration of calcaneal morphology using triangular tube-to-bar external fixation should be considered a viable alternative in the treatment of displaced intra-articular fractures of the calcaneus.

Influence of prey body characteristics and performance on predator selection.

PubMed

Holmes, Thomas H; McCormick, Mark I

2009-03-01

At the time of settlement to the reef environment, coral reef fishes differ in a number of characteristics that may influence their survival during a predatory encounter. This study investigated the selective nature of predation by both a multi-species predator pool, and a single common predator (Pseudochromis fuscus), on the reef fish, Pomacentrus amboinensis. The study focused on the early post-settlement period of P. amboinensis, when mortality, and hence selection, is known to be highest. Correlations between nine different measures of body condition/performance were examined at the time of settlement, in order to elucidate the relationships between different traits. Single-predator (P. fuscus) choice trials were conducted in 57.4-l aquaria with respect to three different prey characteristics [standard length (SL), body weight and burst swimming speed], whilst multi-species trials were conducted on open patch reefs, manipulating prey body weight only. Relationships between the nine measures of condition/performance were generally poor, with the strongest correlations occurring between the morphological measures and within the performance measures. During aquaria trials, P. fuscus was found to be selective with respect to prey SL only, with larger individuals being selected significantly more often. Multi-species predator communities, however, were selective with respect to prey body weight, with heavier individuals being selected significantly more often than their lighter counterparts. Our results suggest that under controlled conditions, body length may be the most important prey characteristic influencing prey survival during predatory encounters with P. fuscus. In such cases, larger prey size may actually be a distinct disadvantage to survival. However, these relationships appear to be more complex under natural conditions, where the expression of prey characteristics, the selectivity fields of a number of different predators, their relative abundance, and the action of external environmental characteristics, may all influence which individuals survive.

Tracheal reconstruction with a composite graft: fascial flap-wrapped allogenic aorta with external cartilage-ring support

PubMed Central

Wurtz, Alain; Hysi, Ilir; Kipnis, Eric; Zawadzki, Christophe; Hubert, Thomas; Jashari, Ramadan; Copin, Marie-Christine; Jude, Brigitte

2013-01-01

OBJECTIVES Animal and clinical studies have demonstrated the feasibility of tracheal replacement by silicone-stented allogenic aortas. In clinical trials, however, this graft did not show mature cartilage regeneration into the grafts as was observed in animal models. To solve this issue, we investigated tracheal replacement with a composite graft based on a fascial flap-wrapped allogenic aorta with external cartilage-ring support in a rabbit model. METHODS Seven male 'Géant des Flandres' and 'New Zealand' rabbits served as donors of aortas and cartilage rings, respectively. Nineteen female 'New Zealand' rabbits were used as recipients. First, in nine animals, neoangiogenesis of the composite graft following a wrap using a pedicled lateral thoracic fascial flap and implantation under the skin of the chest wall was investigated. Animal sacrifice was scheduled at regular intervals up to 38 days. Second, 10 animals underwent tracheal replacement with the composite graft after a 7-to-9 day revascularization period, and were followed-up to death. Macroscopic and microscopic examinations were used to study the morphology, stiffness and viability of the construct. RESULTS There was one operative death after tracheal replacement. The first group of animals was found to have a satisfactory tubular morphology and stiffness of their construct associated with preserved histological structure of cartilages and moderate to severe aortic ischaemic lesions. In the group of rabbits having undergone tracheal replacement, the anatomical results were characterized by a discrepancy between the severity of ischaemic lesions involving both allogenic aorta and cartilage rings and the satisfactory biomechanical characteristics of the graft in 7 of 10 animals, probably due to cartilage calcification deposits associated with inflammatory scar tissue ensuring the stiffness of the construct. CONCLUSIONS Our investigations demonstrate the feasibility of the replacement of circumferential tracheal defects using our composite graft. Future experiments using therapeutic bronchoscopy tools are required to draw conclusions regarding the effectiveness of this tracheal substitute in the long-term. PMID:23049080

The Interstellar Medium in External Galaxies: Summaries of contributed papers

NASA Technical Reports Server (NTRS)

Hollenbach, David J. (Editor); Thronson, Harley A., Jr. (Editor)

1990-01-01

The Second Wyoming Conference entitled, The Interstellar Medium in External Galaxies, was held on July 3 to 7, 1989, to discuss the current understanding of the interstellar medium in external galaxies and to analyze the basic physical processes underlying interstellar phenomena. The papers covered a broad range of research on the gas and dust in external galaxies and focused on such topics as the distribution and morphology of the atomic, molecular, and dust components; the dynamics of the gas and the role of the magnetic field in the dynamics; elemental abundances and gas depletions in the atomic and ionized components; cooling flows; star formation; the correlation of the nonthermal radio continuum with the cool component of the interstellar medium; the origin and effect of hot galactic halos; the absorption line systems seen in distant quasars; and the effect of galactic collisions.

Odorant transfer characteristics of white bread during baking.

PubMed

Onishi, Masanobu; Inoue, Michiko; Araki, Tetsuya; Iwabuchi, Hisakatsu; Sagara, Yasuyuki

2011-01-01

The potent odorants in the crust and crumb of white bread were identified and quantified by gas chromatography-mass spectrometry and gas chromatography/olfactometry. The weight loss ratio of the samples baked at 220 °C was controlled in the range of 0-28%. The odorants were classified into 5 types by the transfer characteristics: i) All amounts of odorant transferred from the crust to external space (type-I). ii) All transferred from the crust to the crumb and external space (type-II). iii) Certain amount remaining in the crust and the rest transferred to the crumb and external space (type-III). iv) All transferred from the crumb to external space (type-IV). v) Certain amount remaining in the crumb and the rest transferred to the crust and external space (type-V). The odorants of type-IV were not apparent after the crust had formed. The results indicate that the crust could be a barrier to prevent the odorants from being transferred to external space.

Effectiveness of External Electric Field Treatment of Conjugated Polymers in Bulk-Heterojunction Solar Cells.

PubMed

Solanki, Ankur; Bagui, Anirban; Long, Guankui; Wu, Bo; Salim, Teddy; Chen, Yongsheng; Lam, Yeng Ming; Sum, Tze Chien

2016-11-30

External electric field treatment (EFT) on P3HT:PCBM bulk heterojunction (BHJ) devices was recently found to be a viable approach for improving the power conversion efficiencies (PCEs) through modulating the blend nanomorphology. However, its effectiveness over the broad family of polymer-fullerene blends remains unclear. Herein, we investigate the effects of external EFT on various polymer-fullerene blends with distinct morphologies stemming from the difference in molecular structure of the polymers (i.e., semicrystalline vs amorphous) in a bid to establish a clear morphology-function-charge dynamics relationship to the photovoltaic performance. Our findings reveal that EFT promotes self-organization of the semicrystalline thiophene-based conjugated polymers (i.e., P3HT and P3BT) while it was ineffective for the amorphous polymers (i.e., PTB7 and PCPDTBT) even at the maximum applied E-field of 8 kV cm -1 . Transient absorption spectroscopy shows an improvement in the initial charge-carrier and polaron formation from delocalized excitons in the E-field treated semicrystalline blends compared to their untreated reference samples. Interfacial trap-assisted monomolecular and trap-free bimolecular recombination at nanosecond-microsecond time scale in the E-field treated P3BT:PC60BM devices are significantly suppressed. Importantly, our findings shed new light and provide guidelines on the effectiveness of utilizing external EFT to enhance the PCEs of a larger family of conjugated polymer-based BHJ OSCs.

Modeling the characteristic etch morphologies along specific crystallographic orientations by anisotropic chemical etching

NASA Astrophysics Data System (ADS)

Li, Kun-Dar; Miao, Jin-Ru

2018-02-01

To improve the advanced manufacturing technology for functional materials, a sophisticated control of chemical etching process is highly demanded, especially in the fields of environment and energy related applications. In this study, a phase-field-based model is utilized to investigate the etch morphologies influenced by the crystallographic characters during anisotropic chemical etching. Three types of etching modes are inspected theoretically, including the isotropic, <100> and <111> preferred oriented etchings. Owing to the specific etching behavior along the crystallographic directions, different characteristic surface structures are presented in the simulations, such as the pimple-like, pyramidal hillock and ridge-like morphologies. In addition, the processing parameters affecting the surface morphological formation and evolution are also examined systematically. According to the numerical results, the growth mechanism of surface morphology in a chemical etching is revealed distinctly. While the etching dynamics plays a dominant role on the surface formation, the characteristic surface morphologies corresponding to the preferred etching direction become more apparent. As the atomic diffusion turned into a determinative factor, a smoothened surface would appear, even under the anisotropic etching conditions. These simulation results provide fundamental information to enhance the development and application of anisotropic chemical etching techniques.

Serrated adenocarcinoma morphology in colorectal mucinous adenocarcinoma is associated with improved patient survival

PubMed Central

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

Prenatal development of the agouti (Dasyprocta prymnolopha Wagler, 1831): External features and growth curves.

PubMed

Fortes, Eunice Anita de Moura; Ferraz, Maíra Soares; Bezerra, Dayseanny Oliveira; Júnior, Aírton Mendes Conde; Cabral, Rosa Maria; Sousa, Francisco das Chagas Araújo; Almeida, Hatawa Melo; Pessoa, Gerson Tavares; Menezes, Danilo José Ayres de; Guerra, Sérgio Paulo Lima; Sampaio, Ivan Barbosa Machado; Assis Neto, Antônio Chaves; Carvalho, Maria Acelina Martins de

2013-08-01

The gestation period in agoutis can range from 104 to 120 days. Knowledge regarding the morphological characteristics of embryos and fetuses is important as a base for studies in reproduction biotechnology, such as in vitro fertilization, embryo transfer and helps in determining congenital anomalies during the development phase. Thus, given the importance and lack of information about agouti embryology, the objective of this study was to characterize the external morphology and define the biometry of embryos and fetuses, at different days of development. Nine females were submitted to daily colpocytology to identify the estrus, confirm mating and identify day zero of the gestation. When the mating was confirmed they were weighed, underwent abdominal ultrasonography and surgery was conducted on the females at the gestational ages of 25, 30, 35, 40, 45, 50, 75 and 100 days. Sixteen embryos/fetuses were weighed and measured. Agouti embryos at 25 days after mating are "C" shaped, with primitive structures, 0.4±0.01cm crown-rump and weighed 0.06±0.01g; at 30 days after mating the crown-rump was 0.95±0.07cm and weighed 0.28±0.00g; at 35 days after mating the crown-rump was 155±0.07cm and weighed 0.38±0.01g; at 40 days after mating the crown-rump was 2.25±0.21cm and weighed 1.25±0.07g; at 45 days after mating the crown-rump was 3.45±0.35cm and weighed 2.75±0.64g; at 50 days after mating the crown-rump was 5.0±0.3cm and weighed 7.01±2.6g; at 75 days after mating, the skin was dark, the crown-rump was 10.0±0.14cm and weighed 55.2±0.07g. At 100 days after mating, the crown-rump was 13.8±0.49cm and fetuses weighed 136.7±9.40g. Based on the morphological data assessed the embryo and fetus age could be assessed and the size and average weight of agouti embryos was established. Copyright © 2013 Elsevier B.V. All rights reserved.

Child Characteristics as Moderators of the Association between Family Stress and Children's Internalizing, Externalizing, and Peer Rejection

ERIC Educational Resources Information Center

Gaylord, Noni K.; Kitzmann, Katherine M.; Lockwood, Rebecca L.

2003-01-01

We examined child characteristics of coping strategies, age, and gender as moderators of the association between family stressors and internalizing, externalizing, and peer rejection in a sample of 228 3rd-5th grade children. Consistent with previous research, children in the current study who experienced a higher number of family stressors were…

Controlling the Internal Heat Transfer Coefficient by the Characteristics of External Flows

NASA Astrophysics Data System (ADS)

Zhuromskii, V. M.

2018-01-01

The engineering-physical fundamentals of substance synthesis in a boiling apparatus are presented. We have modeled a system of automatic stabilization of the maximum internal heat transfer coefficient in such an apparatus by the characteristics of external flows on the basis of adaptive seeking algorithms. The results of operation of the system in the shop are presented.

Internal and External reconnection in a Series of Homologous Solar Flares

NASA Technical Reports Server (NTRS)

Sterling, Alphonse C.; Moore, Ronald L.; Rose, M. Franklin (Technical Monitor)

2000-01-01

Using data from the Extreme Ultraviolet Telescope (EIT) on SOHO and the Soft X-ray Telescope (SXT) on Yohkoh, we examine a series of morphologically homologous solar flares occurring in NOAA AR 8210 over May 1-2, 1998. An emerging flux region (EFR) impacted against a sunspot to the west and next to a coronal hole to the east is the source of the repeated flaring. An SXT sigmoid parallels the EFR's neutral line at the site of the initial flaring in soft X-rays. In EIT, each flaring episode begins with the formation of a crinkle pattern external to the EFR. These EIT crinkles move out from, and then in toward, the EFR with velocities approximately 20 km/s. A shrinking and expansion of the width of the coronal hole coincides with the crinkle activity, and generation and evolution of a postflare loop system begins near the. time of crinkle formation. Using a schematic based on magnetograms of the region, we suggest that these observations are consistent with the standard reconnection-based model for solar eruptions, but modified by the presence of the additional magnetic fields of the sunspot and coronal hole. In the schematic, internal reconnection begins inside of the EFR-associated fields, unleashing a flare, postflare loops, and a CME. External reconnection, first occurring between the escaping CME and the coronal hole field, and second occurring between fields formed as a result of the first external reconnection, results in the EIT crinkles and changes in the coronal hole boundary. By the end of the second external reconnection, the initial setup is reinstated; thus the sequence can repeat, resulting in morphologically homologous eruptions. Our inferred magnetic topology is similar to that suggested in the "breakout model" of eruptions [Antiochos, 1998], although we cannot determine if our eruptions are released primarily by the breakout mechanism (external reconnection) or, alternatively, are released primarily by the internal reconnection.

Internal and External Reconnection Series Homologous Solar Flares

NASA Technical Reports Server (NTRS)

Sterling, Alphonse C.; Moore, Ronald L.

2001-01-01

Using data from the extreme ultraviolet imaging telescope (EIT) on SOHO and the soft X-ray telescope (SXT) on Yohkoh, we examine a series of morphologically homologous solar flares occurring in National Oceanic and Atmospheric Administration (NOAA) active region 8210 over May 1-2, 1998. An emerging flux region (EFR) impacted against a sunspot to the west and next to a coronal hole to the east is the source of the repeated flaring. An SXT sigmoid parallels the EFR's neutral line at the site of the initial flaring in soft X rays. In EIT each flaring episode begins with the formation of a crinkle pattern external to the EFR. These EIT crinkles move out from, and then in toward, the EFR with velocities approx. 20 km/ s. A shrinking and expansion of the width of the coronal hole coincides with the crinkle activity, and generation and evolution of a postflare loop system begins near the time of crinkle formation. Using a schematic based on magnetograms of the region, we suggest that these observations are consistent with the standard reconnection-based model for solar eruptions but are modified by the presence of the additional magnetic fields of the sunspot and coronal hole. In the schematic, internal reconnection begins inside of the EFR-associated fields, unleashing a flare, postflare loops, and a coronal mass ejection (CME). External reconnection, first occurring between the escaping CME and the coronal hole field and second occurring between fields formed as a result of the first external reconnection, results in the EIT crinkles and changes in the coronal hole boundary. By the end of the second external reconnection, the initial setup is reinstated; thus the sequence can repeat, resulting in morphologically homologous eruptions. Our inferred magnetic topology is similar to that suggested in the "breakout model" of eruptions although we cannot determine if our eruptions are released primarily by the breakout mechanism (external reconnection) or, alternatively, primarily by the internal reconnection.

T2 mapping in patellar chondromalacia.

PubMed

Ruiz Santiago, Fernando; Pozuelo Calvo, Rocío; Almansa López, Julio; Guzmán Álvarez, Luis; Castellano García, María Del Mar

2014-06-01

To study the correlation between the T2 relaxation times of the patellar cartilage and morphological MRI findings of chondromalacia. This prospective study comprises 50 patients, 27 men and 23 women suffering of anterior knee pain (mean age: 29.7, SD 8.3 years; range: 16-45 years). MRI of 97 knees were performed in these patients at 1.5T magnet including sagittal T1, coronal intermediate, axial intermediate fat sat and T2 mapping. Chondromalacia was assessed using a modified version of Noyes classification. The relaxation time, T2, was studied segmenting the full thickness of the patellar cartilage in 12 areas: 4 proximal (external facet-proximal-lateral (EPL), external facet-proximal-central (EPC), internal facet-proximal-central (IPC), internal facet-proximal-medial (IPM), 4 in the middle section (external facet-middle-lateral (EML), external facet-middle-central (EMC), internal facet-middle-central (IMC), internal facet-middle-medial (IMM) and 4 distal (external facet-distal-lateral (EDL), external facet-distal-central (EDC), internal facet-distal-central (IDC), internal facet-distal-medial (IDM). T2 values showed a significant increase in mild chondromalacia regarding normal cartilage in most of the cartilage areas (p<0.05), except in the internal distal facet (IDC and IDM), EPC, EDL, and IMM. Severe chondromalacia was characterized by a fall of T2 relaxation times with loss of statistical significant differences in comparison with normal cartilage, except in EMC and IMC, where similar values as mild chondromalacia were maintained (p<0.05). Steepest increase in T2 values of patellar cartilage occurs in early stages of patellar cartilage degeneration. Progression of morphologic changes of chondromalacia to more severe degrees is associated to a new drop of T2 relaxation times approaching basal values in most of the areas of the patellar cartilage, except in the central area of the middle section, where T2 values remain increased. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Understanding the effects of strain on morphological instabilities of a nanoscale island during heteroepitaxial growth

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

Feng, Lu; Wang, Jing; Wang, Shibin

A comprehensive morphological stability analysis of a nanoscale circular island during heteroepitaxial growth is presented based on continuum elasticity theory. The interplay between kinetic and thermodynamic mechanisms is revealed by including strain-related kinetic processes. In the kinetic regime, the Burton-Cabrera-Frank model is adopted to describe the growth front of the island. Together with kinetic boundary conditions, various kinetic processes including deposition flow, adatom diffusion, attachment-detachment kinetics, and the Ehrlich-Schwoebel barrier can be taken into account at the same time. In the thermodynamic regime, line tension, surface energy, and elastic energy are considered. As the strain relief in the early stagesmore » of heteroepitaxy is more complicated than commonly suggested by simple consideration of lattice mismatch, we also investigate the effects of external applied strain and elastic response due to perturbations on the island shape evolution. The analytical expressions for elastic fields induced by mismatch strain, external applied strain, and relaxation strain are presented. A systematic approach is developed to solve the system via a perturbation analysis which yields the conditions of film morphological instabilities. Consistent with previous experimental and theoretical work, parametric studies show the kinetic evolution of elastic relaxation, island morphology, and film composition under various conditions. Our present work offers an effective theoretical approach to get a comprehensive understanding of the interplay between different growth mechanisms and how to tailor the growth mode by controlling the nature of the crucial factors.« less

Changes in the gait characteristics caused by external load, ground slope and velocity variation

NASA Astrophysics Data System (ADS)

Mrozowski, Jerzy; Awrejcewicz, Jan

2011-05-01

The complexity of the human gait manifests itself by lots of parameters that can evoke different changes in the walking manner. They can be divided into two groups: inherent, like anthropometric features or peculiar psychomotor type, and those related to the external conditions. The aim of the paper is to analyze the influence of three parameters, i.e. external load, ground slope and gait velocity, on the locomotion characteristics and the gait stability. Within the framework of investigations for different values of the mentioned parameters a film registration of the trajectories of selected kinematic nodes during some gait cycles has been carried out. The obtained data was a subject of numerical calculation aimed at extracting the essential properties of the principal gait characteristics.

Portable image analysis system for characterizing aggregate morphology.

DOT National Transportation Integrated Search

2008-01-01

In the last decade, the application of image-based evaluation of particle shape, angularity and texture has been widely researched to characterize aggregate morphology. These efforts have been driven by the knowledge that the morphologic characterist...

Hypersonic aerodynamic characteristics of NR-ATP orbiter, orbiter with external tank, and ascent configuration

NASA Technical Reports Server (NTRS)

Ashby, G. C., Jr.

1973-01-01

A scale model of the North American Rockwell ATP Orbiter with and without the external tank has been tested in a 22-inch helium tunnel at Mach 20 and a Reynolds number based on model length, of 2.14 times one million. Longitudinal and lateral-directional data were determined for the orbiter alone while only longitudinal characteristics and elevon roll effectiveness were investigated for the orbiter/tank combination. Oil flow and electron beam flow visualization studies were conducted for the orbiter alone, orbiter with external tank and the ascent configuration.

A review of trabecular bone functional adaptation: what have we learned from trabecular analyses in extant hominoids and what can we apply to fossils?

PubMed

Kivell, Tracy L

2016-04-01

Many of the unresolved debates in palaeoanthropology regarding evolution of particular locomotor or manipulative behaviours are founded in differing opinions about the functional significance of the preserved external fossil morphology. However, the plasticity of internal bone morphology, and particularly trabecular bone, allowing it to respond to mechanical loading during life means that it can reveal greater insight into how a bone or joint was used during an individual's lifetime. Analyses of trabecular bone have been commonplace for several decades in a human clinical context. In contrast, the study of trabecular bone as a method for reconstructing joint position, joint loading and ultimately behaviour in extant and fossil non-human primates is comparatively new. Since the initial 2D studies in the late 1970s and 3D analyses in the 1990 s, the utility of trabecular bone to reconstruct behaviour in primates has grown to incorporate experimental studies, expanded taxonomic samples and skeletal elements, and improved methodologies. However, this work, in conjunction with research on humans and non-primate mammals, has also revealed the substantial complexity inherent in making functional inferences from variation in trabecular architecture. This review addresses the current understanding of trabecular bone functional adaptation, how it has been applied to hominoids, as well as other primates and, ultimately, how this can be used to better interpret fossil hominoid and hominin morphology. Because the fossil record constrains us to interpreting function largely from bony morphology alone, and typically from isolated bones, analyses of trabecular structure, ideally in conjunction with that of cortical structure and external morphology, can offer the best resource for reconstructing behaviour in the past. © 2016 Anatomical Society.

The Unique Dorsal Brood Pouch of Thermosbaenacea (Crustacea, Malacostraca) and Description of an Advanced Developmental Stage of Tulumella unidens from the Yucatan Peninsula (Mexico), with a Discussion of Mouth Part Homologies to Other Malacostraca

PubMed Central

Olesen, Jørgen; Boesgaard, Tom; Iliffe, Thomas M.

2015-01-01

The Thermosbaenacea, a small taxon of crustaceans inhabiting subterranean waters, are unique among malacostracans as they brood their offspring dorsally under the carapace. This habit is of evolutionary interest but the last detailed report on thermosbaenacean development is more than 40 years old. Here we provide new observations on an ovigerous female of Tulumella unidens with advanced developmental stages in its brood chamber collected from an anchialine cave at the Yucatan Peninsula, which is only the third report on developmental stages of Thermosbaenacea and the first for the genus Tulumella. Significant in a wider crustacean context, we report and discuss hitherto unexplored lobate structures inside the brood chamber of the female originating at the first (maxilliped) and second thoracic segments, which are most likely modified epipods, perhaps serving as gills. At the posterior margin of carapace of the female are rows of large spines preventing the developing stages from falling out. The external morphology of the advanced developmental stages is described in much detail, providing information on e.g., carapace formation and early limb morphology. Among the hitherto unknown structures in the advanced developmental stages provided by this study are the presence of an embryonic dorsal organ and rudimentary ‘naupliar processes’ of the second antennae. Since most hypotheses on crustacean (and malacostracan and peracaridan) relationship rest on external limb morphology, we use early limb bud morphology of Tulumella to better establish thermosbaenacean limb homologies to those of other crustaceans, which is a necessary basis for future morphology based phylogenetic considerations. PMID:25901753

The Unique Dorsal Brood Pouch of Thermosbaenacea (Crustacea, Malacostraca) and Description of an Advanced Developmental Stage of Tulumella unidens from the Yucatan Peninsula (Mexico), with a Discussion of Mouth Part Homologies to Other Malacostraca.

PubMed

Olesen, Jørgen; Boesgaard, Tom; Iliffe, Thomas M

2015-01-01

The Thermosbaenacea, a small taxon of crustaceans inhabiting subterranean waters, are unique among malacostracans as they brood their offspring dorsally under the carapace. This habit is of evolutionary interest but the last detailed report on thermosbaenacean development is more than 40 years old. Here we provide new observations on an ovigerous female of Tulumella unidens with advanced developmental stages in its brood chamber collected from an anchialine cave at the Yucatan Peninsula, which is only the third report on developmental stages of Thermosbaenacea and the first for the genus Tulumella. Significant in a wider crustacean context, we report and discuss hitherto unexplored lobate structures inside the brood chamber of the female originating at the first (maxilliped) and second thoracic segments, which are most likely modified epipods, perhaps serving as gills. At the posterior margin of carapace of the female are rows of large spines preventing the developing stages from falling out. The external morphology of the advanced developmental stages is described in much detail, providing information on e.g., carapace formation and early limb morphology. Among the hitherto unknown structures in the advanced developmental stages provided by this study are the presence of an embryonic dorsal organ and rudimentary 'naupliar processes' of the second antennae. Since most hypotheses on crustacean (and malacostracan and peracaridan) relationship rest on external limb morphology, we use early limb bud morphology of Tulumella to better establish thermosbaenacean limb homologies to those of other crustaceans, which is a necessary basis for future morphology based phylogenetic considerations.

Chonopeltis australis (Crustacea) male reproductive system morphology; sperm transfer and review of reproduction in Branchiura.

PubMed

Neethling, Lourelle Alicia Martins; Avenant-Oldewage, Annemariè

2015-02-01

The morphology of the male reproductive system as well as sperm transfer in Branchiura has been described for Dolops ranarum and Argulus japonicus. In this study, the reproductive system and accessory structures are described for male Chonopeltis australis using histology, light microscopy, and scanning electron microscopy. For the first time, we describe sperm transfer by means of a spermatophore in this genus. The internal and external morphology and mechanism of sperm transfer is compared with other Branchiura, where it has been described. The morphology of the reproductive system of C. australis is similar to that of D. ranarum while the accessory structures and the spermatophore produced are similar to that of A. japonicus. A revision of the definition of Branchiura with respect to reproduction is provided. © 2014 Wiley Periodicals, Inc.

Plant morphological characteristics as a tool in monitoring response to silvicultural activities

Treesearch

David S. Buckley; John C. Zasada; John C., II Tappeiner; Douglas M. Stone

1997-01-01

Monitoring environmental change through documentation of species composition becomes problematic when compositional changes take several years to occur or simply do not occur following silvicultural treatment. Morphological characteristics (e.g., leaf area, node density, bud number) change in many plant species in response to factors such as light availability, soil...

A simple genetic architecture underlies morphological variation in dogs.

PubMed

Boyko, Adam R; Quignon, Pascale; Li, Lin; Schoenebeck, Jeffrey J; Degenhardt, Jeremiah D; Lohmueller, Kirk E; Zhao, Keyan; Brisbin, Abra; Parker, Heidi G; vonHoldt, Bridgett M; Cargill, Michele; Auton, Adam; Reynolds, Andy; Elkahloun, Abdel G; Castelhano, Marta; Mosher, Dana S; Sutter, Nathan B; Johnson, Gary S; Novembre, John; Hubisz, Melissa J; Siepel, Adam; Wayne, Robert K; Bustamante, Carlos D; Ostrander, Elaine A

2010-08-10

Domestic dogs exhibit tremendous phenotypic diversity, including a greater variation in body size than any other terrestrial mammal. Here, we generate a high density map of canine genetic variation by genotyping 915 dogs from 80 domestic dog breeds, 83 wild canids, and 10 outbred African shelter dogs across 60,968 single-nucleotide polymorphisms (SNPs). Coupling this genomic resource with external measurements from breed standards and individuals as well as skeletal measurements from museum specimens, we identify 51 regions of the dog genome associated with phenotypic variation among breeds in 57 traits. The complex traits include average breed body size and external body dimensions and cranial, dental, and long bone shape and size with and without allometric scaling. In contrast to the results from association mapping of quantitative traits in humans and domesticated plants, we find that across dog breeds, a small number of quantitative trait loci (< or = 3) explain the majority of phenotypic variation for most of the traits we studied. In addition, many genomic regions show signatures of recent selection, with most of the highly differentiated regions being associated with breed-defining traits such as body size, coat characteristics, and ear floppiness. Our results demonstrate the efficacy of mapping multiple traits in the domestic dog using a database of genotyped individuals and highlight the important role human-directed selection has played in altering the genetic architecture of key traits in this important species.

Numerical investigation on the dynamics and evolution mechanisms of multiple-current-pulse behavior in homogeneous helium dielectric-barrier discharges at atmospheric pressure

NASA Astrophysics Data System (ADS)

Zhang, Yuhui; Ning, Wenjun; Dai, Dong

2018-03-01

A systematic investigation on the dynamics and evolution mechanisms of multiple-current-pulse (MCP) behavior in homogeneous dielectric barrier discharge (HDBD) is carried out via fluid modelling. Inspecting the simulation results, two typical discharge regimes, namely the MCP-Townsend regime and MCP-glow regime, are found prevailing in MCP discharges, each with distinctive electrical and dynamic properties. Moreover, the evolution of MCP behavior with external parameters altering are illustrated and explicitly discussed. It is revealed that the discharge undergoes some different stages as external parameters vary, and the discharge in each stage follows a series of distinctive pattern in morphological characteristics and evolution trends. Among those stages, the pulse number per half cycle is perceived to observe non-monotonic variations with applied voltage amplitude (Vam) and gap width (dg) increasing, and a merging effect among pulses, mainly induced by the enhanced contribution of sinusoidal component to the total current, is considered responsible for such phenomenon. The variation of incipient discharge peak phase (Φpm) is dominated by the value of Vam as well as the proportion of total applied voltage that drops across the gas gap. Moreover, an abnormal, dramatic elevation in Jpm with dg increasing is observed, which could be evinced by the strengthened glow discharge structure and therefore enhanced space charge effect.

A Simple Genetic Architecture Underlies Morphological Variation in Dogs

PubMed Central

Schoenebeck, Jeffrey J.; Degenhardt, Jeremiah D.; Lohmueller, Kirk E.; Zhao, Keyan; Brisbin, Abra; Parker, Heidi G.; vonHoldt, Bridgett M.; Cargill, Michele; Auton, Adam; Reynolds, Andy; Elkahloun, Abdel G.; Castelhano, Marta; Mosher, Dana S.; Sutter, Nathan B.; Johnson, Gary S.; Novembre, John; Hubisz, Melissa J.; Siepel, Adam; Wayne, Robert K.; Bustamante, Carlos D.; Ostrander, Elaine A.

2010-01-01

Domestic dogs exhibit tremendous phenotypic diversity, including a greater variation in body size than any other terrestrial mammal. Here, we generate a high density map of canine genetic variation by genotyping 915 dogs from 80 domestic dog breeds, 83 wild canids, and 10 outbred African shelter dogs across 60,968 single-nucleotide polymorphisms (SNPs). Coupling this genomic resource with external measurements from breed standards and individuals as well as skeletal measurements from museum specimens, we identify 51 regions of the dog genome associated with phenotypic variation among breeds in 57 traits. The complex traits include average breed body size and external body dimensions and cranial, dental, and long bone shape and size with and without allometric scaling. In contrast to the results from association mapping of quantitative traits in humans and domesticated plants, we find that across dog breeds, a small number of quantitative trait loci (≤3) explain the majority of phenotypic variation for most of the traits we studied. In addition, many genomic regions show signatures of recent selection, with most of the highly differentiated regions being associated with breed-defining traits such as body size, coat characteristics, and ear floppiness. Our results demonstrate the efficacy of mapping multiple traits in the domestic dog using a database of genotyped individuals and highlight the important role human-directed selection has played in altering the genetic architecture of key traits in this important species. PMID:20711490

Hemodynamic and morphological characteristics of unruptured posterior communicating artery aneurysms with oculomotor nerve palsy.

PubMed

Lv, Nan; Yu, Ying; Xu, Jinyu; Karmonik, Christof; Liu, Jianmin; Huang, Qinghai

2016-08-01

OBJECT Unruptured posterior communicating artery (PCoA) aneurysms with oculomotor nerve palsy (ONP) have a very high risk of rupture. This study investigated the hemodynamic and morphological characteristics of intracranial aneurysms with high rupture risk by analyzing PCoA aneurysms with ONP. METHODS Fourteen unruptured PCoA aneurysms with ONP, 33 ruptured PCoA aneurysms, and 21 asymptomatic unruptured PCoA aneurysms were included in this study. The clinical, morphological, and hemodynamic characteristics were compared among the different groups. RESULTS The clinical characteristics did not differ among the 3 groups (p > 0.05), whereas the morphological and hemodynamic analyses showed that size, aspect ratio, size ratio, undulation index, nonsphericity index, ellipticity index, normalized wall shear stress (WSS), and percentage of low WSS area differed significantly (p < 0.05) among the 3 groups. Furthermore, multiple comparisons revealed that these parameters differed significantly between the ONP group and the asymptomatic unruptured group and between the ruptured group and the asymptomatic unruptured group, except for size, which differed significantly only between the ONP group and the asymptomatic unruptured group (p = 0.0005). No morphological or hemodynamic parameters differed between the ONP group and the ruptured group. CONCLUSIONS Unruptured PCoA aneurysms with ONP demonstrated a distinctive morphological-hemodynamic pattern that was significantly different compared with asymptomatic unruptured PCoA aneurysms and was similar to ruptured PCoA aneurysms. The larger size, more irregular shape, and lower WSS might be related to the high rupture risk of PCoA aneurysms.

[Mothers' difficulty in childrearing classified in terms of their children's behavioral characteristics].

PubMed

Sakata, Sachi; Naruse, Takashi; Taguchi, Atsuko; Murashima, Sachiyo

2014-01-01

Mothers who experience difficulty in childrearing are becoming increasingly more prevalent in Japan. This study described and classified mothers' childrearing difficulty in terms of their children's behavioral characteristics and related factors. Self-administered questionnaires were distributed to 818 mothers at their children's 3-year-old health checkup in eight suburban cities in Japan. The questionnaire consisted of items assessing the mother's experience of difficulty in childrearing for the child undergoing the checkup. The subjects were classified into four groups according to their children's behavioral characteristics: "low needs," "internalizing behavior," "externalizing behavior," and "comorbid internalizing-externalizing behavior." Multiple regression analysis was performed to examine the relationships between mothers' difficulty in childrearing and related factors. A total of 775 respondents were divided as follows: 332 mothers had children with low needs, 104 had those with internalizing behavior, 230 had those with externalizing behavior, and 109 had those with comorbid internalizing-externalizing behavior. Mothers in the low needs group showed less childrearing difficulty than did mothers in the other groups. Childrearing difficulty increased by group in the following order: internalizing, externalizing, and comorbid internalizing-externalizing. In all four groups, mothers with low self-efficacy and less appraisal support from their family encountered greater childrearing difficulty. In the low needs group, experiencing childrearing difficulty with another child was related experiencing childrearing difficulty with the child undergoing the checkup. In the internalizing behavior group, mothers who had experienced greater difficulty in childrearing were more likely to be housewives and of younger age, and were more likely to have had boys as the child undergoing the checkup. In the externalizing behavior group, mothers with more difficulty in childrearing were more likely to be younger and less healthy, have less appraisal support from their friends, and live in apartments. In the comorbid internalizing-externalizing group, if the mothers were housewives, they were more likely to have difficulty in caring for their other children, receive less appraisal support from their friends, and experience more difficulty in childrearing. The results showed that mothers' difficulty in childrearing and the factors related to this difficulty differed according to their children's behavioral characteristics. Public health nurses could provide more effective care and support to mothers by considering children's behavioral characteristics.

Comparative Molecular and Morphological Variation Analysis of Siderastrea (Anthozoa, Scleractinia) Reveals the Presence of Siderastrea stellata in the Gulf of Mexico.

PubMed

García, Norberto A Colín; Campos, Jorge E; Musi, José L Tello; Forsman, Zac H; Muñoz, Jorge L Montero; Reyes, Alejandro Monsalvo; González, Jesús E Arias

2017-02-01

The genus Siderastrea exhibits high levels of morphological variability. Some of its species share similar morphological characteristics with congeners, making their identification difficult. Siderastrea stellata has been reported as an intermediary of S. siderea and S. radians in the Brazilian reef ecosystem. In an earlier study conducted in Mexico, we detected Siderastrea colonies with morphological features that were not consistent with some siderastreid species previously reported in the Gulf of Mexico. Thus, we performed a combined morphological and molecular analysis to identify Siderastrea species boundaries from the Gulf of Mexico. Some colonies presented high morphologic variability, with characteristics that corresponded to Siderastrea stellata. Molecular analysis, using the nuclear ITS and ITS2 region, corroborated the morphological results, revealing low genetic variability between S. radians and S. stellata. Since the ITS sequences did not distinguish between Siderastrea species, we used the ITS2 region to differentiate S. stellata from S. radians. This is the first report of Siderastrea stellata and its variability in the Gulf of Mexico that is supported by morphological and molecular analyses.

Numerical Simulations of Silverpit Crater Collapse

NASA Technical Reports Server (NTRS)

Collins, G. S.; Turtle, E. P.; Melosh, H. J.

2003-01-01

The Silverpit crater is a recently discovered, 60-65 Myr old complex crater, which lies buried beneath the North Sea, about 150 km east of Britain. High-resolution images of Silverpit's subsurface structure, provided by three-dimensional seismic reflection data, reveal an inner-crater morphology similar to that expected for a 5-8 km diameter terrestrial crater. The crater walls show evidence of terracestyle slumping and there is a distinct central uplift, which may have produced a central peak in the pristine crater morphology. However, Silverpit is not a typical 5-km diameter terrestrial crater, because it exhibits multiple, concentric rings outside the main cavity. External concentric rings are normally associated with much larger impact structures, for example Chicxulub on Earth, or Orientale on the Moon. Furthermore, external rings associated with large impacts on the terrestrial planets and moons are widely-spaced, predominantly inwardly-facing, asymmetric scarps. However, the seismic data show that the external rings at Silverpit represent closely-spaced, concentric fault-bound graben, with both inwardly and outwardly facing faults-carps. This type of multi-ring structure is directly analogous to the Valhalla-type multi-ring basins found on the icy satellites. Thus, the presence and style of the multiple rings at Silverpit is surprising given both the size of the crater and its planetary setting.

Perchlorate disrupts embryonic androgen synthesis and reproductive development in threespine stickleback without changing whole-body levels of thyroid hormone

PubMed Central

Petersen, Ann M.; Dillon, Danielle; Bernhardt, Richard A.; Torunsky, Roberta; Postlethwait, John H.; von Hippel, Frank A.; Buck, C. Loren; Cresko, William A.

2014-01-01

Perchlorate, an environmental contaminant, disrupts normal functioning of the thyroid. We previously showed that perchlorate disrupts behavior and gonad development, and induces external morphological changes in a vertebrate model organism, the threespine stickleback. Whether perchlorate alters these phenotypes via a thyroid-mediated mechanism, and the extent to which the effects depend on dose, are unknown. To address these questions, we chronically exposed stickleback to control conditions and to three concentrations of perchlorate (10, 30 and 100 ppm) at various developmental stages from fertilization to reproductive maturity. Adults chronically exposed to perchlorate had increased numbers of thyroid follicles and decreased numbers of thyrocytes. Surprisingly, T4 and T3 levels in larval, juvenile, and adult whole fish chronically exposed to perchlorate did not differ from controls, except at the lowest perchlorate dose, suggesting a non-monotonic dose response curve. We found no detectable abnormalities in external phenotype at any dose of perchlorate, indicating that the increased number of thyroid follicles compensated for the disruptive effects of these doses. In contrast to external morphology, gonadal development was altered substantially, with the highest dose of perchlorate causing the largest effects. Perchlorate increased the number both of early stage ovarian follicles in females and of advanced spermatogenic stages in males. Perchlorate also disrupted embryonic androgen levels. We conclude that chronic perchlorate exposure may not result in lasting adult gross morphological changes but can produce lasting modifications to gonads when compensation of T3 and T4 levels occurs by thyroid follicle hyperplasia. Perchlorate may therefore affect vertebrate development via both thyroidal and non-thyroidal mechanisms. PMID:25448260

Targeting dopa-sensitive and dopa-resistant gait dysfunction in Parkinson's disease: selective responses to internal and external cues.

PubMed

Rochester, Lynn; Baker, Katherine; Nieuwboer, Alice; Burn, David

2011-02-15

Independence of certain gait characteristics from dopamine replacement therapies highlights its complex pathophysiology in Parkinson's disease (PD). We explored the effect of two different cue strategies on gait characteristics in relation to their response to dopaminergic medications. Fifty people with PD (age 69.22 ± 6.6 years) were studied. Participants walked with and without cues presented in a randomized order. Cue strategies were: (1) internal cue (attention to increase step length) and (2) external cue (auditory cue with instruction to take large step to the beat). Testing was carried out two times at home (on and off medication). Gait was measured using a Stride Analyzer (B&L Engineering). Gait outcomes were walking speed, stride length, step frequency, and coefficient of variation (CV) of stride time and double limb support duration (DLS). Walking speed, stride length, and stride time CV improved on dopaminergic medications, whereas step frequency and DLS CV did not. Internal and external cues increased stride time and walking speed (on and off dopaminergic medications). Only the external cue significantly improved stride time CV and DLS CV, whereas the internal cue had no effect (on and off dopaminergic medications). Internal and external cues selectively modify gait characteristics in relation to the type of gait disturbance and its dopa-responsiveness. Although internal (attention) and external cues target dopaminergic gait dysfunction (stride length), only external cues target stride to stride fluctuations in gait. Despite an overlap with dopaminergic pathways, external cues may effectively address nondopaminergic gait dysfunction and potentially increase mobility and reduce gait instability and falls. Copyright © 2010 Movement Disorder Society.

Temporal and spatial variation of morphological descriptors for atmospheric aerosols collected in Mexico City

NASA Astrophysics Data System (ADS)

China, S.; Mazzoleni, C.; Dubey, M. K.; Chakrabarty, R. K.; Moosmuller, H.; Onasch, T. B.; Herndon, S. C.

2010-12-01

We present an analysis of morphological characteristics of atmospheric aerosol collected during the MILAGRO (Megacity Initiative: Local and Global Research Observations) field campaign that took place in Mexico City in March 2006. The sampler was installed on the Aerodyne mobile laboratory. The aerosol samples were collected on nuclepore clear polycarbonate filters mounted in Costar pop-top membrane holders. More than one hundred filters were collected at different ground sites with different atmospheric and geographical characteristics (urban, sub-urban, mountain-top, industrial, etc.) over a month period. Selected subsets of these filters were analyzed for aerosol morphology using a scanning electron microscope and image analysis techniques. In this study we investigate spatial and temporal variations of aerosol shape descriptors, morphological parameters, and fractal dimension. We also compare the morphological results with other aerosol measurements such as aerosol optical properties(scattering and absorption) and size distribution data. Atmospheric aerosols have different morphological characteristics depending on many parameters such as emission sources, atmospheric formation pathways, aging processes, and aerosol mixing state. The aerosol morphology influences aerosol chemical and mechanical interactions with the environment, physical properties, and radiative effects. In this study, ambient aerosol particles have been classified in different shape groups as spherical, irregularly shaped, and fractal-like aggregates. Different morphological parameters such as aspect ratio, roundness, feret diameter, etc. have been estimated for irregular shaped and spherical particles and for different kinds of soot particles including fresh soot, collapsed and coated soot. Fractal geometry and image processing have been used to obtain morphological characteristics of different soot particles. The number of monomers constituting each aggregate and their diameters were measured and used to estimate an ensemble three-dimensional (3-d) fractal dimension. One-dimensional (1-d) and two-dimensional (2-d) fractal geometries have been measured using a power-law scaling relationship between 1-d and 2-d properties of projected images. Temporal variations in fractal dimension of soot-like aggregates have been observed at the mountaintop site and spatial variation of fractal dimension and other morphological descriptors of different shaped particles have been investigated for the different ground sites.

Features of current-voltage characteristic of nonequilibrium trench MOS barrier Schottky diode

NASA Astrophysics Data System (ADS)

Mamedov, R. K.; Aslanova, A. R.

2018-06-01

The trench MOS barrier Schottky diodes (TMBS diode) under the influence of the voltage drop of the additional electric field (AEF) appearing in the near-contact region of the semiconductor are in a nonequilibrium state and their closed external circuit flows currents in the absence of an external voltage. When an external voltage is applied to the TMBS diode, the current transmission is described by the thermionic emission theory with a specific feature. Both forward and reverse I-V characteristics of the TMBS diode consist of two parts. In the initial first part of the forward I-V characteristic there are no forward currents, but reverse saturation currents flow, in its subsequent second part the currents increase exponentially with the voltage. In the initial first part of the reverse I-V characteristic, the currents increase in an abrupt way and in the subsequent second part the saturation currents flow under the action of the image force. The mathematical expressions for forward and reverse I-V characteristic of the TMBS diode and also narrow or nanostructure Schottky diode are proposed, which are in good agreement with the results of experimental and calculated I-V characteristics.

[Biological characteristics of calliphoridae and its application in forensic medicine].

PubMed

Zhao, Boa; Wen, Charn; Qi, Li-Li; Wang, He; Wang, Ji

2013-12-01

Diptera Calliphoridae is the first major kind of flies that appears on the decomposed corpses. In forensic entomology, according to the living characteristics of Calliphoridae flies, we could accurately estimate postmortem interval (PMI) in a murder or unidentified case and could provide useful clues to solve the case. This paper introduces the characteristics of the biology and morphology of Diptera Calliphoridae, and reviews the combined application of forensic entomology, molecular biology, mathematical morphology and toxicology.

Sensing surface morphology of biofibers by decorating spider silk and cellulosic filaments with nematic microdroplets

PubMed Central

Aguirre, Luis E.; de Oliveira, Alexandre; Seč, David; Čopar, Simon; Almeida, Pedro L.; Ravnik, Miha; Godinho, Maria Helena; Žumer, Slobodan

2016-01-01

Probing the surface morphology of microthin fibers such as naturally occurring biofibers is essential for understanding their structural properties, biological function, and mechanical performance. The state-of-the-art methods for studying the surfaces of biofibers are atomic force microscopy imaging and scanning electron microscopy, which well characterize surface geometry of the fibers but provide little information on the local interaction potential of the fibers with the surrounding material. In contrast, complex nematic fluids respond very well to external fields and change their optical properties upon such stimuli. Here we demonstrate that liquid crystal droplets deposited on microthin biofibers—including spider silk and cellulosic fibers—reveal characteristics of the fibers’ surface, performing as simple but sensitive surface sensors. By combining experiments and numerical modeling, different types of fibers are identified through the fiber-to-nematic droplet interactions, including perpendicular and axial or helicoidal planar molecular alignment. Spider silks align nematic molecules parallel to fibers or perpendicular to them, whereas cellulose aligns the molecules unidirectionally or helicoidally along the fibers, indicating notably different surface interactions. The nematic droplets as sensors thus directly reveal chirality of cellulosic fibers. Different fiber entanglements can be identified by depositing droplets exactly at the fiber crossings. More generally, the presented method can be used as a simple but powerful approach for probing the surface properties of small-size bioobjects, opening a route to their precise characterization. PMID:26768844

Sensing surface morphology of biofibers by decorating spider silk and cellulosic filaments with nematic microdroplets.

PubMed

Aguirre, Luis E; de Oliveira, Alexandre; Seč, David; Čopar, Simon; Almeida, Pedro L; Ravnik, Miha; Godinho, Maria Helena; Žumer, Slobodan

2016-02-02

Probing the surface morphology of microthin fibers such as naturally occurring biofibers is essential for understanding their structural properties, biological function, and mechanical performance. The state-of-the-art methods for studying the surfaces of biofibers are atomic force microscopy imaging and scanning electron microscopy, which well characterize surface geometry of the fibers but provide little information on the local interaction potential of the fibers with the surrounding material. In contrast, complex nematic fluids respond very well to external fields and change their optical properties upon such stimuli. Here we demonstrate that liquid crystal droplets deposited on microthin biofibers--including spider silk and cellulosic fibers--reveal characteristics of the fibers' surface, performing as simple but sensitive surface sensors. By combining experiments and numerical modeling, different types of fibers are identified through the fiber-to-nematic droplet interactions, including perpendicular and axial or helicoidal planar molecular alignment. Spider silks align nematic molecules parallel to fibers or perpendicular to them, whereas cellulose aligns the molecules unidirectionally or helicoidally along the fibers, indicating notably different surface interactions. The nematic droplets as sensors thus directly reveal chirality of cellulosic fibers. Different fiber entanglements can be identified by depositing droplets exactly at the fiber crossings. More generally, the presented method can be used as a simple but powerful approach for probing the surface properties of small-size bioobjects, opening a route to their precise characterization.

Historical Perspectives and Future Needs in the Development of the Soil Series Concept

NASA Astrophysics Data System (ADS)

Beaudette, Dylan E.; Brevik, Eric C.; Indorante, Samuel J.

2016-04-01

The soil series concept is an ever-evolving understanding of soil profile observations, their connection to the landscape, and functional limits on the range in characteristics that affect management. Historically, the soil series has played a pivotal role in the development of soil-landscape theory, modern soil survey methods, and concise delivery of soils information to the end-user-- in other words, soil series is the palette from which soil survey reports are crafted. Over the last 20 years the soil series has received considerable criticism as a means of soil information organization (soil survey development) and delivery (end-user application of soil survey data), with increasing pressure (internal and external) to retire the soil series. We propose that a modern re-examination of soil series information could help address several of the long-standing critiques of soil survey: consistency across survey vintage and political divisions and more robust estimates of soil properties and associated uncertainty. A new library of soil series data would include classic narratives describing morphology and management, quantitative descriptions of soil properties and their ranges, graphical depiction of the relationships between associated soil series, block diagrams illustrating soil-landscape models, maps of series distribution, and a probabilistic representation of a "typical" soil profile. These data would be derived from re-correlation of existing morphologic and characterization data informed by modern statistical methods and regional expertise.

New identification of the moray eel Gymnothorax minor (Temminck & Schlegel, 1846) in China (Anguilliformes, Muraenidae).

PubMed

Li, Yuan; Zhang, Liyan; Zhao, Linlin; Feng, Ji; Loh, Karhoe; Zheng, Xinqing; Lin, Longshan

2018-01-01

A new identification of Gymnothorax minor (Temminck & Schlegel, 1846) is documented based on morphological characteristics and DNA barcoding. Sixty-one individuals of G. minor were collected from the East China Sea and the South China Sea. This species was previously reported as Gymnothorax reticularis Bloch, 1795 in China because of the similarity in external shape and color. Gymnothorax minor can be easily distinguished from G. reticularis by its color pattern of 18-20 irregular dark brown vertical bars and the body having scattered small brown spots. Additionally, the teeth are uniserial on both jaws, and the vertebrae number 137-139. By combining congener sequences of the cytochrome oxidase I (COI) gene from GenBank, two groups were detected among all the COI sequences of the currently named G. minor , which further indicated that two valid species were present based on genetic distance. A divergence also occurred on the number of vertebrae between the northern and southern populations. The phylogenetic and morphological analysis strongly supports that the northern and southern populations of G. minor are two different species. Furthermore, the distribution area of the northern G. minor has expanded southward to 5°15'N in the South China Sea. More specimens of G. minor and G. reticularis are crucial in order to define their geographical distribution boundaries and provide the correct DNA barcoding.

Parametric investigation of enclosed keeper discharge characteristics

NASA Technical Reports Server (NTRS)

Sheheen, T. W.; Finke, R. C.

1973-01-01

Volt-ampere discharge characteristics of an enclosed keeper hollow cathode discharge were measured as a function of the mercury flow rate and external circuit impedance. Discharge currents were varied from 0 to 1 ampere and voltages were 7 to 39 volts. Batteries and a vacuum tube control circuit were used to obtain characteristics curves that were independent of power supply impedance. Variation of the neutral flow results in changes in the discharge which interact with the impedance of the external circuit, and under some conditions, give rise to multiple operating points.

The Vainshtein mechanism in the cosmic web

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

Falck, Bridget; Koyama, Kazuya; Zhao, Gong-bo

We investigate the dependence of the Vainshtein screening mechanism on the cosmic web morphology of both dark matter particles and halos as determined by ORIGAMI. Unlike chameleon and symmetron screening, which come into effect in regions of high density, Vainshtein screening instead depends on the dimensionality of the system, and screened bodies can still feel external fields. ORIGAMI is well-suited to this problem because it defines morphologies according to the dimensionality of the collapsing structure and does not depend on a smoothing scale or density threshold parameter. We find that halo particles are screened while filament, wall, and void particlesmore » are unscreened, and this is independent of the particle density. However, after separating halos according to their large scale cosmic web environment, we find no difference in the screening properties of halos in filaments versus halos in clusters. We find that the fifth force enhancement of dark matter particles in halos is greatest well outside the virial radius. We confirm the theoretical expectation that even if the internal field is suppressed by the Vainshtein mechanism, the object still feels the fifth force generated by the external fields, by measuring peculiar velocities and velocity dispersions of halos. Finally, we investigate the morphology and gravity model dependence of halo spins, concentrations, and shapes.« less

A novel method for determining sex in late term gestational mice based on the external genitalia

PubMed Central

Murdaugh, Laura B.; Mendoza-Romero, Haley N.; Fish, Eric W.

2018-01-01

In many experiments using fetal mice, it is necessary to determine the sex of the individual fetus. However, other than genotyping for sex-specific genes, there is no convenient, reliable method of sexing mice between gestational day (GD) 16.5 and GD 18.0. We designed a rapid, relatively simple visual method to determine the sex of mouse fetuses in the GD 16.5—GD 18.0 range that can be performed as part of a routine morphological assessment. By examining the genitalia for the presence or absence of key features, raters with minimal experience with the method were able to correctly identify the sex of embryos with 99% accuracy, while raters with no experience were 95% accurate. The critical genital features include: the presence or absence of urethral seam or proximal urethral meatus; the shape of the genitalia, and the presence or absence of an area related to the urethral plate. By comparing these morphological features of the external genitalia, we show a simple, accurate, and fast way to determine the sex of late stage mouse fetuses. Integrating this method into regular morphological assessments will facilitate the determination of sex differences in fetuses between GD 16.5 and GD 18.0. PMID:29617407

A striking new genus and species of cave-dwelling frog (Amphibia: Anura: Microhylidae: Asterophryinae) from Thailand

PubMed Central

Suwannapoom, Chatmongkon; Tunprasert, Jitthep; Ruangsuwan, Thiti; Pawangkhanant, Parinya; Korost, Dmitriy V.

2018-01-01

We report on a discovery of Siamophryne troglodytes Gen. et sp. nov., a new troglophilous genus and species of microhylid frog from a limestone cave in the tropical forests of western Thailand. To assess its phylogenetic relationships we studied the 12S rRNA–16S rRNA mtDNA fragment with final alignment comprising up to 2,591 bp for 56 microhylid species. Morphological characterization of the new genus is based on examination of external morphology and analysis of osteological characteristics using microCT-scanning. Phylogenetic analyses place the new genus into the mainly Australasian subfamily Asterophryinae as a sister taxon to the genus Gastrophrynoides, the only member of the subfamily known from Sundaland. The new genus markedly differs from all other Asterophryinae members by a number of diagnostic morphological characters and demonstrates significant mtDNA sequence divergence. We provide a preliminary description of a tadpole of the new genus. Thus, it represents the only asterophryine taxon with documented free-living larval stage and troglophilous life style. Our work demonstrates that S. troglodytes Gen. et sp. nov. represents an old lineage of the initial radiation of Asterophryinae which took place in the mainland Southeast Asia. Our results strongly support the “out of Indo-Eurasia” biogeographic scenario for this group of frogs. To date, the new frog is only known from a single limestone cave system in Sai Yok District of Kanchanaburi Province of Thailand; its habitat is affected by illegal bat guano mining and other human activities. As such, S. troglodytes Gen. et sp. nov. is likely to be at high risk of habitat loss. Considering high ecological specialization and a small known range of the new taxon, we propose a IUCN Red List status of endangered for it. PMID:29497587

A striking new genus and species of cave-dwelling frog (Amphibia: Anura: Microhylidae: Asterophryinae) from Thailand.

PubMed

Suwannapoom, Chatmongkon; Sumontha, Montri; Tunprasert, Jitthep; Ruangsuwan, Thiti; Pawangkhanant, Parinya; Korost, Dmitriy V; Poyarkov, Nikolay A

2018-01-01

We report on a discovery of Siamophryne troglodytes Gen. et sp. nov., a new troglophilous genus and species of microhylid frog from a limestone cave in the tropical forests of western Thailand. To assess its phylogenetic relationships we studied the 12S rRNA-16S rRNA mtDNA fragment with final alignment comprising up to 2,591 bp for 56 microhylid species. Morphological characterization of the new genus is based on examination of external morphology and analysis of osteological characteristics using microCT-scanning. Phylogenetic analyses place the new genus into the mainly Australasian subfamily Asterophryinae as a sister taxon to the genus Gastrophrynoides , the only member of the subfamily known from Sundaland. The new genus markedly differs from all other Asterophryinae members by a number of diagnostic morphological characters and demonstrates significant mtDNA sequence divergence. We provide a preliminary description of a tadpole of the new genus. Thus, it represents the only asterophryine taxon with documented free-living larval stage and troglophilous life style. Our work demonstrates that S. troglodytes Gen. et sp. nov. represents an old lineage of the initial radiation of Asterophryinae which took place in the mainland Southeast Asia. Our results strongly support the "out of Indo-Eurasia" biogeographic scenario for this group of frogs. To date, the new frog is only known from a single limestone cave system in Sai Yok District of Kanchanaburi Province of Thailand; its habitat is affected by illegal bat guano mining and other human activities. As such, S. troglodytes Gen. et sp. nov. is likely to be at high risk of habitat loss. Considering high ecological specialization and a small known range of the new taxon, we propose a IUCN Red List status of endangered for it.

Genetic diversity in a morphologically conservative invasive taxon: Multiple introductions of swamp eels to the southeastern United States

USGS Publications Warehouse

Collins, T.M.; Trexler, J.C.; Nico, L.G.; Rawlings, T.A.

2002-01-01

Genetic analysis of introduced populations, especially in morphologically conservative taxa, can clarify introduction histories, identify management units and source populations, provide a more realistic estimate of the frequency of successful invasion, and suggest strategies for preventing further introductions. In the last 7 years, populations of swamp eels, referred to the Asian genus Monopterus (Family Synbranchidae) on the basis of external morphology, have been discovered in aquatic habitats near Atlanta, Georgia; Tampa, Florida; North Miami, Florida; and most recently in close proximity to Everglades National Park in Homestead, Florida. Swamp eels are large predators capable of dispersal over land and have the potential to disrupt already threatened ecosystems. We analyzed mitochondrial DNA sequences from four known populations in the continental United States and samples from Malaysia, Indonesia, Vietnam, and two locations in China to determine introduction histories, source populations, genetic diversity, and relationships among populations. Our results indicate that there have been at least three independent introductions of genetically distinct forms. Introduced populations in close proximity (separated by <40 km) are genetically distinct. The level of sequence difference among introduced populations reaches levels seen among sister families of teleost fishes for the same region of the mitochondrial genome. These genetically distinct introduced populations in all likelihood represent at least two and possibly three species. Regardless of species status, these genetically distinct lineages may be expected to vary in ecological or life-history traits, representing different potential threats to the ecosystems where they have been introduced. Given the success of swamp eels in invading many habitats around the world, further study of these eels is warranted to elucidate the characteristics of successful invaders and invasions.

Morphology-Dependent Resonances and Their Applications to Sensing in Aerospace Environments

NASA Technical Reports Server (NTRS)

Adamovsky, G.; Otugen, M.V.

2009-01-01

This paper reviews recent developments in Morphology-Dependent Resonance (MDR)-based sensors for aerospace applications. The sensor concept is based on the detection of small shifts of optical resonances (also called the whispering gallery modes or WGM) of dielectric spheres caused by external effects. Recent developments in MRD-based micro-optical sensors for temperature, force, pressure, and concentration are discussed. In addition to the experimental configurations used in each type of prototype sensor, a brief overview is also given for analytical approaches to describe the sensor principle.

Position-related differences in selected morphological body characteristics of top-level handball players.

PubMed

Sibila, Marko; Pori, Primoz

2009-12-01

We aimed to establish the main morphological characteristics of Slovenian junior and senior national handball team players. Morphological characteristics for various player subgroups (goalkeepers, wings, back players and pivots) were also determined so as to establish whether they had distinct profiles. The subjects were 78 handball players who were members of the Slovenian junior and senior national team in the period from 2000 to 2007. A standardised anthropometric protocol was used to assess the subjects' morphological characteristics. The measurements included 23 different anthropometric measures. Data were processed with the SPSS computer programme. First, basic statistical characteristics of anthropometric measures were obtained for all subjects together and then for each group separately. Somatotypes were determined using Heath-Carter's method. Endomorphic, mesomorphic and ectomorphic components were calculated by computer on the basis of formulas. In order to determine differences in the body composition and anthropometric data of the subjects playing in different positions, a one-way analysis of variance was employed. The results show that on average the wings differ the most from the other player groups in terms of their morphological body characteristics. The values of their body height, body mass and the quantity of subcutaneous fat are statistically significantly lower than those of players in the other groups. Goalkeepers are relatively tall, with high values of body mass and low values of transuersal measures. Their skin folds are the most pronounced among all groups on average and their share of subcutaneous fat in total body mass is the highest. Consequently, their endomorphic component of the somatotype is pronounced. Pivots and back players are becoming increasingly similar in terms of their morphological body characteristics. Pivots maintain greater robustness, have a higher quantity of muscle mass as well as more pronounced transversal measures and a mesomorphic component of the somatotype. The results of our study confirm that groups of handball players occupying different positions differ amongst themselves in terms of many measurements. This is a result of specific requirements of handball play which are to be fulfilled by players.

Heat Effects on Living Plants

Treesearch

Robert C. Hare

1961-01-01

This review of knowledge concerning the effects of high temperatures on plants was undertaken in preparation for research aimed at determining how forest fires affect physiological processes in woody species. Major subjects discussed include morphological and physiological responses to high temperatures, external and internal factors governing these responses,...

The Leafhoppers: Anatomy, Physiology and Behavior of Feeding and Its Sensory Mediation

USDA-ARS?s Scientific Manuscript database

The present book contains chapters summarizing all major aspects of the biology of leafhoppers (family Cicadellidae), among the most numerous and important insect pests in the world. Major chapter topics discussed include internal and external morphology, physiology, behavior, reproduction, taxonom...

Algorithm of resonance orders for the objects

NASA Astrophysics Data System (ADS)

Zhang, YongGang; Zhang, JianXue

2018-03-01

In mechanical engineering, the object resonance phenomena often occur when the external incident wave frequency is close to object of the natural frequency. Object resonance phenomena get the maximum value when the external incident frequency is equal to object the natural frequency. Experiments found that resonance intension of the object is changed, different objects resonance phenomena present different characteristics of ladders. Based on object orders resonance characteristics, the calculation method of object orders resonance is put forward in the paper, and the application for the light and sound waves on the seven order resonance characteristics by people feel, the result error is less than 1%.Visible in this paper, the method has high accuracy and usability. The calculation method reveals that some object resonance occur present order characteristic only four types, namely the first-orders resonance characteristics, third-orders characteristics, five orders characteristic, and seven orders characteristic.

Identification of Important Iranian Hardwoods by Morphological Properties of Vessel Elements (Maceration process)

Treesearch

Vahidreza Safdari; Margaret S. Devall

2011-01-01

For the identification of small to large wood samples and various types of composites that may not provide enough of all surfaces necessary to reveal diagnostic characteristics, such as sawdust, decayed wood fragments, archeological wood, and even large wood samples, morphological and anatomical characteristics of vessels are very useful. In this research,...

Effects of air pollution on morphological and anatomical characteristics of Pinus Eldarica Wood

Treesearch

Vahidreza Safdari; Moinuddin Ahmed; Margaret S. Devall; Vilma Bayramzadeh

2012-01-01

Air pollution, including automobile exhaust pollution, can affect anatomical and morphological characteristics of wood. In order to evaluate this subject, the Pinus eldarica trees of Chitgar Park in Tehran, which extends from a crowded highway in the south (polluted site) to the semi polluted midsection and to Alborz Mountain in the north (unpolluted...

A case study on the labeling of bottarga produced in Sardinia from ovaries of grey mullets (Mugil cephalus and Mugil capurrii) caught in Eastern Central Atlantic coasts

PubMed Central

Piras, Pierluigi; Sardu, Francesco; Meloni, Domenico; Riina, Maria Vittoria; Beltramo, Chiara; Acutis, Pier Luigi

2018-01-01

The aim of this case study is to show how traditional and molecular methods can be employed to identify the Mugilidae species currently used in Sardinia (Italy) to produce the traditional bottarga for the processing of their ovaries. A total of six specimens of Mugil cephalus (n=3) and Mugil capurrii (n=3) were subjected to external morphology and meristic measurements. Subsequently, tissue samples of white muscle and ovaries from three individuals per species were underwent PCR-sequencing assay of mitochondrial DNA cytochrome oxidase subunit I (COI). The external morphology and meristic characters showed a sufficient level of reliability in the identification between the two species. At the same time, the molecular techniques showed the discriminatory power and confirmed the correct species identification in all the sampling units. DNA barcoding may be an effective aid to traditional taxonomy and can facilitate accurate species identification among the Mugilidae. PMID:29732322

Reduction of sexual dimorphism in stream-resident forms of three-spined stickleback Gasterosteus aculeatus

PubMed Central

Kitano, J.; Mori, S.; Peichel, C. L.

2013-01-01

Sexual dimorphism in geometric body shape and external morphology was compared between marine and stream-resident forms of three-spined stickleback Gasterosteus aculeatus collected from North America and Japan. Some aspects of sexual dimorphism were shared between ecotypes: males had larger heads than females with no significant effect of ecotype on the magnitude of sexual dimorphism. By contrast, a significant sex-by-ecotype interaction was found for body depth. Males tended to have deeper bodies than females in both forms, but the magnitude of sexual dimorphism was reduced in stream-resident forms. Although females were generally larger in standard length and had larger pelvic girdles, significant sexual dimorphism in these traits was not consistently found across populations or ecotypes. These results suggest that some aspects of sexual dimorphism were shared between ecotypes, while others were unique to each population. The results further suggest that ecology may influence the evolution of sexual dimorphism in some external morphological traits, such as body depth. PMID:22220894

Is the spiral morphology of the Elias 2-27 circumstellar disc due to gravitational instability?

NASA Astrophysics Data System (ADS)

Hall, Cassandra; Rice, Ken; Dipierro, Giovanni; Forgan, Duncan; Harries, Tim; Alexander, Richard

2018-06-01

A recent Atacama Large Millimeter/submillimeter Array (ALMA) observation of the Elias 2-27 system revealed a two-armed structure extending out to ˜300 au in radius. The protostellar disc surrounding the central star is unusually massive, raising the possibility that the system is gravitationally unstable. Recent work has shown that the observed morphology of the system can be explained by disc self-gravity, so we examine the physical properties of the disc necessary to detect self-gravitating spiral waves. Using three-dimensional smoothed particle hydrodynamics, coupled with radiative transfer and synthetic ALMA imaging, we find that observable spiral structure can only be explained by self-gravity if the disc has a low opacity (and therefore efficient cooling), and is minimally supported by external irradiation. This corresponds to a very narrow region of parameter space, suggesting that, although it is possible for the spiral structure to be due to disc self-gravity, other explanations, such as an external perturbation, may be preferred.

[The reentrant binomial model of nuclear anomalies growth in rhabdomyosarcoma RA-23 cell populations under increasing doze of rare ionizing radiation].

PubMed

Alekseeva, N P; Alekseev, A O; Vakhtin, Iu B; Kravtsov, V Iu; Kuzovatov, S N; Skorikova, T I

2008-01-01

Distributions of nuclear morphology anomalies in transplantable rabdomiosarcoma RA-23 cell populations were investigated under effect of ionizing radiation from 0 to 45 Gy. Internuclear bridges, nuclear protrusions and dumbbell-shaped nuclei were accepted for morphological anomalies. Empirical distributions of the number of anomalies per 100 nuclei were used. The adequate model of reentrant binomial distribution has been found. The sum of binomial random variables with binomial number of summands has such distribution. Averages of these random variables were named, accordingly, internal and external average reentrant components. Their maximum likelihood estimations were received. Statistical properties of these estimations were investigated by means of statistical modeling. It has been received that at equally significant correlation between the radiation dose and the average of nuclear anomalies in cell populations after two-three cellular cycles from the moment of irradiation in vivo the irradiation doze significantly correlates with internal average reentrant component, and in remote descendants of cell transplants irradiated in vitro - with external one.

Division and dynamic morphology of plastids.

PubMed

Osteryoung, Katherine W; Pyke, Kevin A

2014-01-01

Plastid division is fundamental to the biology of plant cells. Division by binary fission entails the coordinated assembly and constriction of four concentric rings, two internal and two external to the organelle. The internal FtsZ ring and external dynamin-like ARC5/DRP5B ring are connected across the two envelopes by the membrane proteins ARC6, PARC6, PDV1, and PDV2. Assembly-stimulated GTPase activity drives constriction of the FtsZ and ARC5/DRP5B rings, which together with the plastid-dividing rings pull and squeeze the envelope membranes until the two daughter plastids are formed, with the final separation requiring additional proteins. The positioning of the division machinery is controlled by the chloroplast Min system, which confines FtsZ-ring formation to the plastid midpoint. The dynamic morphology of plastids, especially nongreen plastids, is also considered here, particularly in relation to the production of stromules and plastid-derived vesicles and their possible roles in cellular communication and plastid functionality.

European early modern humans and the fate of the Neandertals

PubMed Central

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

Two cases of pseudohermaphroditism in loggerhead sea turtles Caretta caretta.

PubMed

Crespo, Jose Luis; García-Párraga, Daniel; Giménez, Ignacio; Rubio-Guerri, Consuelo; Melero, Mar; Sánchez-Vizcaíno, José Manuel; Marco, Adolfo; Cuesta, Jose A; Muñoz, María Jesús

2013-09-03

Two juvenile (curved carapace lengths: 28 and 30 cm) loggerhead sea turtles Caretta caretta with precocious male external characteristics were admitted to the ARCA del Mar rescue area at the Oceanogràfic Aquarium in Valencia, Spain, in 2009 and 2010. Routine internal laparoscopic examination and subsequent histopathology confirmed the presence of apparently healthy internal female gonads in both animals. Extensive tissue biopsy and hormone induction assays were consistent with female sex. To the best of our knowledge, this is the first report of pseudohermaphroditism in loggerhead sea turtles based on sexual external characteristics and internal laparoscopic examination. Our findings suggest that the practice of using external phenotypical characteristics as the basis for gender identification in sea turtles should be reevaluated. Future research should focus on detecting more animals with sexual defects and their possible effects on the sea turtle population.

Morphological and molecular characterization of Fusarium spp pathogenic to pecan tree in Brazil.

PubMed

Lazarotto, M; Milanesi, P M; Muniz, M F B; Reiniger, L R S; Beltrame, R; Harakava, R; Blume, E

2014-11-11

The occurrence of Fusarium spp associated with pecan tree (Carya illinoinensis) diseases in Brazil has been observed in recent laboratory analyses in Rio Grande do Sul State. Thus, in this study, we i) obtained Fusarium isolates from plants with disease symptoms; ii) tested the pathogenicity of these Fusarium isolates to pecan; iii) characterized and grouped Fusarium isolates that were pathogenic to the pecan tree based on morphological characteristics; iv) identified Fusarium spp to the species complex level through TEF-1α sequencing; and v) compared the identification methods used in the study. Fifteen isolates collected from the inflorescences, roots, and seeds of symptomatic plants (leaf necrosis or root rot) were used for pathogenicity tests. Morphological characterization was conducted using only pathogenic isolates, for a total of 11 isolates, based on the mycelial growth rate, sporulation, colony pigmentation, and conidial length and width variables. Pathogenic isolates were grouped based on morphological characteristics, and molecular characterization was performed by sequencing TEF-1α genes. Pathogenic isolates belonging to the Fusarium chlamydosporum species complex, Fusarium graminearum species complex, Fusarium proliferatum, and Fusarium oxysporum were identified based on the TEF-1α region. Morphological characteristics were used to effectively differentiate isolates and group the isolates according to genetic similarity, particularly conidial width, which emerged as a key morphological descriptor in this study.

Morphological comparison of five species of poison dart frogs of the genus Ranitomeya (Anura: Dendrobatidae) including the skeleton, the muscle system and inner organs.

PubMed

Krings, Markus; Klein, Benjamin; Heneka, Markus J; Rödder, Dennis

2017-01-01

The morphology of larvae stages of most amphibians are often completely different than in adults. Tadpole descriptions have historically been based on external characters like morphometrics, color pattern and oral disc structure. Other papers described anatomical details by the use of dissections. The increase in micro-CT scanning technology provides an opportunity to quantify and describe in detail internal characters like skeleton, musculature and organs. To date, no such tadpole descriptions exist for the well-studied Neotropical poison dart frog genus Ranitomeya (Anura: Dendrobatidae). Here we provide descriptions of the internal skeletal, musculature and organ structures of five Ranitomeya species and then provide morphological comparisons. Contrary to previous observations, closely related species display several morphological differences. For example, we observed considerable variation in chondrocranial characters, the extent of cranial ossifications, the appearance of some cranial muscles and the arrangement of inner organs. Further studies on the tadpole morphology of more species of Ranitomeya and other dendrobatid genera are needed to enable us to understand the complete morphological variation in this group.

Morphological comparison of five species of poison dart frogs of the genus Ranitomeya (Anura: Dendrobatidae) including the skeleton, the muscle system and inner organs

PubMed Central

Krings, Markus; Klein, Benjamin; Heneka, Markus J.

2017-01-01

The morphology of larvae stages of most amphibians are often completely different than in adults. Tadpole descriptions have historically been based on external characters like morphometrics, color pattern and oral disc structure. Other papers described anatomical details by the use of dissections. The increase in micro-CT scanning technology provides an opportunity to quantify and describe in detail internal characters like skeleton, musculature and organs. To date, no such tadpole descriptions exist for the well-studied Neotropical poison dart frog genus Ranitomeya (Anura: Dendrobatidae). Here we provide descriptions of the internal skeletal, musculature and organ structures of five Ranitomeya species and then provide morphological comparisons. Contrary to previous observations, closely related species display several morphological differences. For example, we observed considerable variation in chondrocranial characters, the extent of cranial ossifications, the appearance of some cranial muscles and the arrangement of inner organs. Further studies on the tadpole morphology of more species of Ranitomeya and other dendrobatid genera are needed to enable us to understand the complete morphological variation in this group. PMID:28235032

Staff Perceptions of External versus Internal Teaching and Staff Development.

ERIC Educational Resources Information Center

Clark, Rohan G.; And Others

1984-01-01

A survey of University of New England academic staff was conducted to determine their perceptions of external teaching as part of a larger study to ascertain staff attitudes toward their effectiveness as teachers. Responses related to demands, enjoyment, and benefits of external and internal teaching, and student characteristics are discussed.…

Morphologic and Biochemical Changes in Dogs After Portacaval Shunt Plus Bile Fistula or Ileal Bypass: Failure of Bile Fistula or Ileal Bypass to Prevent Hepatocyte Atrophy

PubMed Central

Thompson, Jon S.; Porter, Kendrick A.; Hayashida, Nobuo; McNamara, Donald J.; Parker, Thomas S.; Russell, William J. I.; Francavilla, Antonio; Starzl, Thomas E.

2010-01-01

External biliary fistula (BF) or ileal bypass (IB) was performed in dogs at the time of or 2 weeks after portacaval shunt (PCS). The pathologic changes in the dog livers 2 to 4 weeks later were compared to those caused by PCS alone. Histopathologic differences between PCS alone vs. PCS plus BF or IB could not be found. Thus, the experiments did not confirm recent observations by others in rats that BF prevents or reverses the hepatic injury of PCS. As estimated by plasma mevalonic acid determinations, the increase in hepatic cholesterol synthesis that is characteristic after BF or IB was suppressed in animals with PCS. BF and IB reduced but did not eliminate the postprandial elevation in serum bile acid that occurs after PCS. The findings have possible relevance in planning the treatment of patients with familial hypercholesterolemia with the combined use of PCS and IB. PMID:6862371

Spatial trends in tidal flat shape and associated environmental parameters in South San Francisco Bay

USGS Publications Warehouse

Bearman, J.A.; Friedrichs, Carl T.; Jaffe, B.E.; Foxgrover, A.C.

2010-01-01

Spatial trends in the shape of profiles of South San Francisco Bay (SSFB) tidal flats are examined using bathymetric and lidar data collected in 2004 and 2005. Eigenfunction analysis reveals a dominant mode of morphologic variability related to the degree of convexity or concavity in the cross-shore profileindicative of (i) depositional, tidally dominant or (ii) erosional, wave impacted conditions. Two contrasting areas of characteristic shapenorth or south of a constriction in estuary width located near the Dumbarton Bridgeare recognized. This pattern of increasing or decreasing convexity in the inner or outer estuary is correlated to spatial variability in external and internal environmental parameters, and observational results are found to be largely consistent with theoretical expectations. Tidal flat convexity in SSFB is observed to increase (in decreasing order of significance) in response to increased deposition, increased tidal range, decreased fetch length, decreased sediment grain size, and decreased tidal flat width. ?? 2010 Coastal Education and Research Foundation.

Microstructural and geometric influences in the protective scales of Atractosteus spatula

PubMed Central

Sherman, Vincent R.; Yaraghi, Nicholas A.; Kisailus, David

2016-01-01

Atractosteus spatula has been described as a living fossil (having existed for 100 Myr), retaining morphological characteristics of early ancestors such as the ability to breathe air and survive above water for hours. Its highly effective armour consists of ganoid scales. We analyse the protective function of the scales and identify key features which lead to their resistance to failure. Microstructural features include: a twisted cross-plied mineral arrangement that inhibits crack propagation in the external ganoine layer, mineral crystals that deflect cracks in the bony region in order to activate the strength of mineralized collagen fibrils, and saw-tooth ridges along the interface between the two scale layers which direct cracks away from the intrinsically weak interface. The macroscale geometry is additionally evaluated and it is shown that the scales retain full coverage in spite of minimal overlap between adjacent scales while conforming to physiologically required strain and maintaining flexibility via a process in which adjacent rows of scales slide and concurrently reorient. PMID:27974575

Microstructural and geometric influences in the protective scales of Atractosteus spatula.

PubMed

Sherman, Vincent R; Yaraghi, Nicholas A; Kisailus, David; Meyers, Marc A

2016-12-01

Atractosteus spatula has been described as a living fossil (having existed for 100 Myr), retaining morphological characteristics of early ancestors such as the ability to breathe air and survive above water for hours. Its highly effective armour consists of ganoid scales. We analyse the protective function of the scales and identify key features which lead to their resistance to failure. Microstructural features include: a twisted cross-plied mineral arrangement that inhibits crack propagation in the external ganoine layer, mineral crystals that deflect cracks in the bony region in order to activate the strength of mineralized collagen fibrils, and saw-tooth ridges along the interface between the two scale layers which direct cracks away from the intrinsically weak interface. The macroscale geometry is additionally evaluated and it is shown that the scales retain full coverage in spite of minimal overlap between adjacent scales while conforming to physiologically required strain and maintaining flexibility via a process in which adjacent rows of scales slide and concurrently reorient. © 2016 The Author(s).

Mechanical stimulation improves tissue-engineered human skeletal muscle

NASA Technical Reports Server (NTRS)

Powell, Courtney A.; Smiley, Beth L.; Mills, John; Vandenburgh, Herman H.

2002-01-01

Human bioartificial muscles (HBAMs) are tissue engineered by suspending muscle cells in collagen/MATRIGEL, casting in a silicone mold containing end attachment sites, and allowing the cells to differentiate for 8 to 16 days. The resulting HBAMs are representative of skeletal muscle in that they contain parallel arrays of postmitotic myofibers; however, they differ in many other morphological characteristics. To engineer improved HBAMs, i.e., more in vivo-like, we developed Mechanical Cell Stimulator (MCS) hardware to apply in vivo-like forces directly to the engineered tissue. A sensitive force transducer attached to the HBAM measured real-time, internally generated, as well as externally applied, forces. The muscle cells generated increasing internal forces during formation which were inhibitable with a cytoskeleton depolymerizer. Repetitive stretch/relaxation for 8 days increased the HBAM elasticity two- to threefold, mean myofiber diameter 12%, and myofiber area percent 40%. This system allows engineering of improved skeletal muscle analogs as well as a nondestructive method to determine passive force and viscoelastic properties of the resulting tissue.

A New Species of Sexually Dimorphic Brittle Star of the Genus Ophiodaphne (Echinodermata: Ophiuroidea).

PubMed

Tominaga, Hideyuki; Hirose, Mamiko; Igarashi, Hikaru; Kiyomoto, Masato; Komatsu, Miéko

2017-08-01

We describe a new species of sexually dimorphic brittle star, Ophiodaphne spinosa, from Japan associated with the irregular sea urchin, Clypeaster japonicus based on its external morphology, and phylogenetic analyses of mitochondrial COI (cytochrome c oxidase subunit I). Females of this new species of Ophiodaphne are characterized mainly by the presence of wavy grooves on the surface of the radial shields, needle-like thorns on the oral skeletal jaw structures, and a low length-to-width ratio of the jaw angle in comparison with those of type specimens of its Ophiodaphne congeners: O. scripta, O. materna, and O. formata. A tabular key to the species characteristics of Ophiodaphne is provided. Phylogenetic analyses indicate that the new species of Ophiodaphne, O. scripta, and O. formata are monophyletic. Our results indicate that the Japanese Ophiodaphne include both the new species and O. scripta, and that there are four Ophiodaphne species of sexually dimorphic brittle stars with androphorous habit.

Three-dimensional shape transformations of hydrogel sheets induced by small-scale modulation of internal stresses

NASA Astrophysics Data System (ADS)

Wu, Zi Liang; Moshe, Michael; Greener, Jesse; Therien-Aubin, Heloise; Nie, Zhihong; Sharon, Eran; Kumacheva, Eugenia

2013-03-01

Although Nature has always been a common source of inspiration in the development of artificial materials, only recently has the ability of man-made materials to produce complex three-dimensional (3D) structures from two-dimensional sheets been explored. Here we present a new approach to the self-shaping of soft matter that mimics fibrous plant tissues by exploiting small-scale variations in the internal stresses to form three-dimensional morphologies. We design single-layer hydrogel sheets with chemically distinct, fibre-like regions that exhibit differential shrinkage and elastic moduli under the application of external stimulus. Using a planar-to-helical three-dimensional shape transformation as an example, we explore the relation between the internal architecture of the sheets and their transition to cylindrical and conical helices with specific structural characteristics. The ability to engineer multiple three-dimensional shape transformations determined by small-scale patterns in a hydrogel sheet represents a promising step in the development of programmable soft matter.

Analysis of the intercaste transcriptional profile of Melipona scutellaris Latreille, 1811 (Hymenoptera, Apidae, Meliponini) by mRNA differential display.

PubMed

Siquieroli, Ana Carolina S; Vieira, Carlos U; Carvalho-Zilse, Gislene A; Goulart, Luiz R; Kerr, Warwick E; Bonetti, Ana M

2009-01-01

In colonies of Melipona scutellaris Latreille, 1811 workers can be found with four ganglion nerve cells, a morphological characteristic of the queen. It is hypothesized that these workers, called intercastes, or phenocopies, are phenotypically-like workers, but genotypically identical to queens due to this specific trait. Workers with the same number of ganglion as queens seem to be intercastes between queens and workers. Our objective was to analyze the mRNA pro files of workers, queens, and intercastes of M. scutellaris through DDRT-PCR. Three hundred (300) pupae with white eyes were collected and externally identified according to the number of abdominal nerve ganglions: workers (5 ganglions), queens (4 ganglions) and intercastes (4 ganglions). The analysis identified differentially expressed transcripts that were present only in workers, but absent in intercastes and queens, confirming the hypothesis, by demonstrating the environmental effect on the queen genotype that generated phenotype-like workers.

[Biochemical changes in apoptosis and methods for their determination (review)].

PubMed

Sedláková, A; Kohút, A; Kalina, I

1999-08-01

Apoptosis or programmed cell death is a physiological process which occurs at different biological states as well as at disease process. Morphologically it is characterized by the chromatine condensation and other changes with preserved integrity of plasmatic membrane. The major and most frequently studied biochemical characteristic of apoptosis is a DNA fragmentation. In our paper attention is directed to the early biochemical changes in cell membranes, i.g., the externalization of phosphatidylserine, hydrolysis of sphingomyeline on the ceramide and activation of phospholipases especially phospholipase A2. In one part we described the changes of cysteine proteases (caspases), which play a key role in the execution of apoptosis. These biochemical changes are associated with ceramide signalization of apoptosis. Briefly are presented also some dates about apoptosis induction with reactive oxygen radicals and the role of the arachidonic acid metabolites in this process. We consider the investigation and determination of these changes as important parameters of apoptosis at some diseases, e.g., cancer or degenerative diseases, and of their treatment.

Precision control of drying using rhythmic dancing of sessile nanoparticle laden droplets

NASA Astrophysics Data System (ADS)

Sanyal, Apratim; Basu, Saptarshi; Chowdhuri, Subham; Kabi, Prasenjit; Chaudhuri, Swetaprovo

2014-04-01

This work analyses the unique spatio-temporal alteration of the deposition pattern of evaporating nanoparticle laden droplets resting on a hydrophobic surface through targeted low frequency substrate vibrations. External excitation near the lowest resonant mode (n = 2) of the droplet initially de-pins and then subsequently re-pins the droplet edge creating pseudo-hydrophilicity (low contact angle). Vibration subsequently induces droplet shape oscillations (cyclic elongation and flattening) resulting in strong flow recirculation. This strong radially outward liquid flow augments nanoparticle transport, vaporization, and agglomeration near the pinned edge resulting in much reduced drying time under certain characteristic frequency of oscillations. The resultant deposit exhibits a much flatter structure with sharp, defined peripheral wedge topology as compared to natural drying. Such controlled manipulation of transport enables tailoring of structural and topological morphology of the deposits and offers possible routes towards controlling the formation and drying timescales which are crucial for applications ranging from pharmaceutics to surface patterning.

Characteristics of the Single-Longitudinal-Mode Planar-Waveguide External Cavity Diode Laser at 1064 nm

NASA Technical Reports Server (NTRS)

Numata, Kenji; Alalusi, Mazin; Stolpner, Lew; Margaritis, Georgios; Camp, Jordan; Krainak, Michael

2014-01-01

We describe the characteristics of the planar-waveguide external cavity diode laser (PW-ECL). To the best of our knowledge, it is the first butterfly-packaged 1064 nm semiconductor laser that is stable enough to be locked to an external frequency reference. We evaluated its performance from the viewpoint of precision experiments. Using a hyperfine absorption line of iodine, we suppressed its frequency noise by a factor of up to 104 at 10 mHz. The PWECL's compactness and low cost make it a candidate to replace traditional Nd:YAG nonplanar ring oscillators and fiber lasers in applications that require a single longitudinal mode.

Differentiating submarine channel-related thin-bedded turbidite facies: Outcrop examples from the Rosario Formation, Mexico

NASA Astrophysics Data System (ADS)

Hansen, Larissa; Callow, Richard; Kane, Ian; Kneller, Ben

2017-08-01

Thin-bedded turbidites deposited by sediment gravity flows that spill from submarine channels often contain significant volumes of sand in laterally continuous beds. These can make up over 50% of the channel-belt fill volume, and can thus form commercially important hydrocarbon reservoirs. Thin-bedded turbidites can be deposited in environments that include levees and depositional terraces, which are distinguished on the basis of their external morphology and internal architecture. Levees have a distinctive wedge shaped morphology, thinning away from the channel, and confine both channels (internal levees) and channel-belts (external levees). Terraces are flat-lying features that are elevated above the active channel within a broad channel-belt. Despite the ubiquity of terraces and levees in modern submarine channel systems, the recognition of these environments in outcrop and in the subsurface is challenging. In this outcrop study of the Upper Cretaceous Rosario Formation (Baja California, Mexico), lateral transects based on multiple logged sections of thin-bedded turbidites reveal systematic differences in sandstone layer thicknesses, sandstone proportion, palaeocurrents, sedimentary structures and ichnology between channel-belt and external levee thin-bedded turbidites. Depositional terrace deposits have a larger standard deviation in sandstone layer thicknesses than external levees because they are topographically lower, and experience a wider range of turbidity current sizes overspilling from different parts of the channel-belt. The thickness of sandstone layers within external levees decreases away from the channel-belt while those in depositional terraces are less laterally variable. Depositional terrace environments of the channel-belt are characterized by high bioturbation intensities, and contain distinctive trace fossil assemblages, often dominated by ichnofabrics of the echinoid trace fossil Scolicia. These assemblages contrast with the lower bioturbation intensities that are recorded from external levee environments where Scolicia is typically absent. Multiple blocks of external levee material are observed in the depositional terrace area where the proximal part of the external levee has collapsed into the channel-belt; their presence characterizes the channel-belt boundary zone. The development of recognition criteria for different types of channel-related thin-bedded turbidites is critical for the interpretation of sedimentary environments both at outcrop and in the subsurface, which can reduce uncertainty during hydrocarbon field appraisal and development.

Characteristics of an external employee assistance programme in Japan.

PubMed

Muto, Takashi; Fujimori, Yuiko; Suzuki, Keiko

2004-12-01

Mental health care is now a major occupational health issue in Japan. Although realizing effective use of external employee assistance programmes (EAPs) has been identified as crucial for mental health care, few scientific papers describe or analyse the characteristics of EAPs in Japan. This study sought to clarify the characteristics of an external EAP in Japan. The characteristics of an external EAP were clarified in terms of programme description and utilization. A total of 10,260 counselling sessions from 1996 to 2000 were used for utilization analysis. The EAP studied had contracts with 133 organizations, half of which were health insurance societies. The EAP provided employees and family members with free, confidential counselling. Annual mean utilization rate per 1000 individuals increased from 1.3 in 1996 to 2.7 in 2000. Less than one-third of counselling sessions were for work-related mental health issues, and male users (30%) consulted significantly more often than female users (14%) for such problems. Among men, career development issues were most common, while job dissatisfaction was highest among women. Absenteeism, depression and fatigue were the most frequently observed problems in both sexes. EAP use in Japan is rising. The majority of its use is for non-work-related health issues. Male users were more likely to consult for work-related mental health problems.

Influence of age on the pattern and outcome of external beam radiotherapy for clinically localized prostate cancer.

PubMed

Ogawa, Kazuhiko; Nakamura, Katsumasa; Onishi, Hiroshi; Koizumi, Masahiko; Sasaki, Tomonari; Araya, Masayuki; Miyabe, Yuuki; Otani, Yuuki; Teshima, Teruki

2006-01-01

The influence of age on the patterns and outcomes of external beam radiotherapy for clinically localized prostate cancer patients was examined. The Japanese Patterns of Care Study surveys were used to compare the processes and outcomes of radical external beam radiotherapy in 140 elderly patients (>75 years old) and 304 younger patients (<75 years old). Although the Karnofsky performance status was significantly different between elderly and younger patients, there were no significant differences in disease characteristics such as pretreatment PSA level, differentiation, Gleason combined score and clinical T stage. There were also no significant differences in the treatment characteristics such as CT-based treatment planning, conformal therapy, total radiation doses (both a median of 66.0 Gy) and hormonal therapy usage. Moreover, no significant differences in overall survival, biochemical relapse-free survival and late toxicity rates were observed between elderly and younger patients. Age did not influence the disease characteristics, patterns of external beam radiotherapy, survival and late toxicities for clinically localized prostate cancer patients. Therefore, radiotherapy could represent an important treatment modality for elderly patients as well as for younger ones.

Biomechanical consequences of callus development in Hoffmann, Wagner, Orthofix and Ilizarov external fixators.

PubMed

Juan, J A; Prat, J; Vera, P; Hoyos, J V; Sánchez-Lacuesta, J; Peris, J L; Dejoz, R; Alepuz, R

1992-09-01

A theoretical analysis by a finite elements model (FEM) of some external fixators (Hoffmann, Wagner, Orthofix and Ilizarov) was carried out. This study considered a logarithmic progress of callus elastic characteristics. A standard configuration of each fixator was defined where design and application characteristics were modified. A comparison among standard configurations and influence of every variation was made with regard to displacement and load transmission at the fracture site. An experimental evaluation of standard configurations was performed with a testing machine. After experimental validation of the theoretical model was achieved, an application of physiological loads which act on a fractured limb during normal gait was analysed. A minimal contribution from an external fixator to the total rigidity of the bone-callus-fixator system was assessed when a callus showing minimum elastic characteristics had just been established. Insufficient rigidity from the fixation devices to assure an adequate immobilization during the early stages of fracture healing was verified. However, regardless of the external fixator, callus development was the overriding element for the rigidity of the fixator-bone system.

Controlling Morphological Parameters of Anodized Titania Nanotubes for Optimized Solar Energy Applications

PubMed Central

Haring, Andrew; Morris, Amanda; Hu, Michael

2012-01-01

Anodized TiO2 nanotubes have received much attention for their use in solar energy applications including water oxidation cells and hybrid solar cells [dye-sensitized solar cells (DSSCs) and bulk heterojuntion solar cells (BHJs)]. High surface area allows for increased dye-adsorption and photon absorption. Titania nanotubes grown by anodization of titanium in fluoride-containing electrolytes are aligned perpendicular to the substrate surface, reducing the electron diffusion path to the external circuit in solar cells. The nanotube morphology can be optimized for the various applications by adjusting the anodization parameters but the optimum crystallinity of the nanotube arrays remains to be realized. In addition to morphology and crystallinity, the method of device fabrication significantly affects photon and electron dynamics and its energy conversion efficiency. This paper provides the state-of-the-art knowledge to achieve experimental tailoring of morphological parameters including nanotube diameter, length, wall thickness, array surface smoothness, and annealing of nanotube arrays.

Differentiating sex and species of Western Grebes (Aechmophorus occidentalis) and Clark's Grebes (Aechmophorus clarkii) and their eggs using external morphometrics and discriminant function analysis

USGS Publications Warehouse

Hartman, C. Alex; Ackerman, Joshua T.; Eagles-Smith, Collin A.; Herzog, Mark

2016-01-01

In birds where males and females are similar in size and plumage, sex determination by alternative means is necessary. Discriminant function analysis based on external morphometrics was used to distinguish males from females in two closely related species: Western Grebe (Aechmophorus occidentalis) and Clark's Grebe (A. clarkii). Additionally, discriminant function analysis was used to evaluate morphometric divergence between Western and Clark's grebe adults and eggs. Aechmophorus grebe adults (n = 576) and eggs (n = 130) were sampled across 29 lakes and reservoirs throughout California, USA, and adult sex was determined using molecular analysis. Both Western and Clark's grebes exhibited considerable sexual size dimorphism. Males averaged 6–26% larger than females among seven morphological measurements, with the greatest sexual size dimorphism occurring for bill morphometrics. Discriminant functions based on bill length, bill depth, and short tarsus length correctly assigned sex to 98% of Western Grebes, and a function based on bill length and bill depth correctly assigned sex to 99% of Clark's Grebes. Further, a simplified discriminant function based only on bill depth correctly assigned sex to 96% of Western Grebes and 98% of Clark's Grebes. In contrast, external morphometrics were not suitable for differentiating between Western and Clark's grebe adults or their eggs, with correct classification rates of discriminant functions of only 60%, 63%, and 61% for adult males, adult females, and eggs, respectively. Our results indicate little divergence in external morphology between species of Aechmophorus grebes, and instead separation is much greater between males and females.

Numerical Simulations of Silverpit Crater Collapse

NASA Technical Reports Server (NTRS)

Collins, G. S.; Ivanov, B. A.; Turtle, E. P.; Melosh, H. J.

2003-01-01

The Silverpit crater is a recently discovered, 60-65 Myr old complex crater, which lies buried beneath the North Sea, about 150 km east of Britain. High-resolution images of Silverpit's subsurface structure, provided by three-dimensional seismic reflection data, reveal an inner-crater morphology similar to that expected for a 5-8 km diameter terrestrial crater. The crater walls show evidence of terrace-style slumping and there is a distinct central uplift, which may have produced a central peak in the pristine crater morphology. However, Silverpit is not a typical 5-km diameter terrestrial crater, because it exhibits multiple, concentric rings outside the main cavity. External concentric rings are normally associated with much larger impact structures, for example Chicxulub on Earth, or Orientale on the Moon. Furthermore, external rings associated with large impacts on the terrestrial planets and moons are widely-spaced, predominantly inwardly-facing, asymmetric scarps. However, the seismic data show that the external rings at Silverpit represent closely-spaced, concentric faultbound graben, with both inwardly and outwardly facing fault-scarps. This type of multi-ring structure directly analogous to the Valhalla-type multi-ring basins found on the icy satellites. Thus, the presence and style of the multiple rings at Silverpit is surprising given both the size of the crater and its planetary setting. A further curiosity of the Silverpit structure is that the external concentric rings appear to be extensional features on the West side of the crater and compressional features on the East side. The crater also lies in a local depression, thought to be created by postimpact movement of a salt layer buried beneath the crater.

A Molecular Key for the Identification of Blow Flies in Southeastern Nebraska

USDA-ARS?s Scientific Manuscript database

The identification of blow flies (Calliphoridae) (typically the first colonizers of cadavers) is difficult, especially in the earlier instars because of their small size, similarity and simplicity in external morphology. We consider how taxonomic keys based on molecular genetic data facilitate accur...

Economics and Environmental Compatibility of Fusion Reactors —Its Analysis and Coming Issues— 4.Economic Effect of Fusion in Energy Market 4.2Various Externalities of Energy Systems and the Integrated Evaluation

NASA Astrophysics Data System (ADS)

Ito, Keishiro

The primacy of a nuclear fusion reactor in a competitive energy market remarkably depends on to what extent the reactor contributes to reduce the externalities of energy. The reduction effects are classified into two effects, which have quite dissimilar characteristics. One is an effect of environmental dimensions. The other is related to energy security. In this study I took up the results of EC's Extern Eproject studies as are presentative example of the former effect. Concerning the latter effect, I clarified the fundamental characteristics of externalities related to energy security and the conceptual framework for the purpose of evaluation. In the socio-economical evaluation of research into and development investments in nuclear fusions reactors, the public will require the development of integrated evaluation systems to support the cost-effect analysis of how well the reduction effects of externalities have been integrated with the effects of technological innovation, learning, spillover, etc.

Firms' contribution to the internal and external employability of older employees: evidence from Germany.

PubMed

Tisch, Anita

2015-03-01

In the examination of older employees' employability, one can distinguish between internal and external employability. Internal employability can be measured by individual employment stability, and external employability occurs when employees replace one employment relationship with another. Most studies focus on the personal skills and characteristics that are necessary to maintain employability. However, external factors also contribute to individual employability. Therefore, this study examines which organisational attributes of firms contribute to older employees' employability in Germany. Taking firm and individual characteristics into account, the results of discrete-time survival models show that in specific organisational structures, older employees have higher internal employability. Accordingly, older employees are more likely to maintain employment in the service sector and in recruiting organisations facing (skilled) labour shortages. However, the results also indicate that financially investing organisations facilitate early labour market exits. With regard to older employees' external employability, the results show only little evidence indicating an association between organisational attributes of firms and the likelihood of job change.

Effect of Spacecraft Environmental Variables on the Flammability of Fire Resistant Fabrics

NASA Astrophysics Data System (ADS)

Osorio, A. F.; Fernandez-Pello, C.; Takahashi, S.; Rodriguez, J.; Urban, D. L.; Ruff, G.

2012-01-01

Fire resistant fabrics are used for firefighter, racecar drivers as well as astronaut suits. However, their fire resistant characteristics depend on the environment conditions and require study. Particularly important is the response of these fabrics to elevated oxygen concentration environments and radiant heat from a source such as an adjacent fire. In this work, experiments using two fire resistant fabrics were conducted to study the effect of oxygen concentration, external radiant flux and oxidizer flow velocity in concurrent flame spread. Results show that for a given fabric the minimum oxygen concentration for flame spread depends strongly on the magnitude of the external radiant flux. At increased oxygen concentrations the external radiant flux required for flame spread decreases. Oxidizer flow velocity influences the external radiant flux only when the convective heat flux from the flame has similar values to the external radiant flux. The results of this work provide further understanding of the flammability characteristics of fire resistant fabrics in environments similar to those of future spacecrafts.

Overview of external Nacelle drag and interference drag

NASA Technical Reports Server (NTRS)

Neal, R. D.

1975-01-01

A historical view of multi-jet engine installations is given that emphasizes integration of the powerplant and the airframe in aircraft design for improved reduction in external nacelle drag and interference drag characteristics.

Coriandrum sativum mediated synthesis of silver nanoparticles and evaluation of their biological characteristics

NASA Astrophysics Data System (ADS)

Senthilkumar, N.; Aravindhan, V.; Ruckmani, K.; Vetha Potheher, I.

2018-05-01

Silver (Ag) nanoparticles (NPs) were prepared by percolated green synthesis method using Coriandrum sativum leaf, root, seed and stem extracts and reported its antibacterial activity. The synthesized Ag NPs were confirmed by UV–visible Spectroscopy, Powder x-ray Diffraction (PXRD), Fourier Transform Infra Red (FT-IR) Spectroscopy analyzes. The Maximum absorbance observed around 400–450 nm reveal the characteristic absorbance of Ag NPs. The Dynamic Light Scattering (DLS) analysis shows the stability of synthesized NPs with average size varying from 35 to 53 nm and also zeta potential stability varying from ‑20 to ‑30 mV. The cubic structure, crystalline nature and purity of the material was confirmed by powder x-ray diffraction studies. FT-IR spectrum shows the presence of various functional groups in the resultant material. The Field Emission Scanning Electron Microscopy (FESEM) image shows the surface morphology of the synthesized NPs and the Energy Dispersive x-ray Analysis (EDAX) confirms the presence of silver metal ions. The Coriandrum sativum aqueous extract exhibited excellent antimicrobial activity against Klebsiella pneumoniae (Gram -ve) bacteria. Numerous studies have been made previously in our field of study but optimization has not been carried out by both extract (different parts like leaf, root, seed and stem) and without addition of any external source such as chemicals, heat etc.

Lexical Morphology: Structure, Process, and Development

ERIC Educational Resources Information Center

Jarmulowicz, Linda; Taran, Valentina L.

2013-01-01

Recent work has demonstrated the importance of derivational morphology to later language development and has led to a consensus that derivation is a lexical process. In this review, derivational morphology is discussed in terms of lexical representation models from both linguistic and psycholinguistic perspectives. Input characteristics, including…

MORPHOLOGICAL DIFFERENCES BETWEEN TWO WHITE-FOOTED MICE, PEROMYSCUS BOYU AND PEROMYSCUS CALIFORNICUS, IN OAK WOODLANDS OF FRESNO COUNTY, CALIFORNIA

Treesearch

ROBERTA J. FARGO; William F. Laudenslayer

1995-01-01

Identification ofPeromyscus species in the field can often be time consuming and inaccurate. Determination of several morphological characteristics is usually required for reliable identification. Characteristics may differ only slightly, can be highly variable, or can overlap among species. In oak woodlands of the southern Sierra Nevada in Fresno county, most...

Effects of Light Regimes on the Biomass and Morphological Characteristics of 2-Year-Old Cherrybark Oak Seedlings

Treesearch

Yanfei Guo; Michael G. Shelton

2004-01-01

We used modified shadehouses to simulate the complex light conditions within forest openings and tested the effects of time of direct light exposure, the ratio of direct light to day length, and daily photosynthetically active radiation on aboveground biomass and morphological characteristics of 2-year-old cherrybark oak (Quercus pagoda Raf.)...

Morphological characteristics and barrier properties of thermoplastic starch/chitosan blown film.

PubMed

Dang, Khanh Minh; Yoksan, Rangrong

2016-10-05

Fabrication of starch-based edible film using blown film extrusion is challenging and interesting because this process provides continuous operation with shorter production time and lower energy consumption, is less labor intensive, and results in higher productivity than the conventional solution casting technique. Previously, we reported on the preparation and some properties of thermoplastic starch/chitosan (TPS/CTS) blown films; however, their morphological characteristics and barrier properties had not yet been elucidated. The present work thus aims to investigate the effect of chitosan (0.37-1.45%) on morphological characteristics, water vapor and oxygen barrier properties as well as hydrophilicity of the TPS and TPS/CTS films. The relationship between morphological characteristics and properties of the films was also discussed. Scanning electron microscopy (SEM), confocal laser scanning microscopy (CLSM) and X-ray photoelectron spectroscopy (XPS) confirmed the distribution and deposition of chitosan on the film surface. The existence of chitosan on the surface imparted the improved water vapor and oxygen barrier properties and the reduced surface hydrophilicity to the film. The results suggest that this biodegradable bio-based TPS/CTS film could potentially be used as an edible film for food and pharmaceutical applications. Copyright © 2016 Elsevier Ltd. All rights reserved.

Clavicle, a neglected bone: morphology and relation to arm movements and shoulder architecture in primates.

PubMed

Voisin, Jean-Luc

2006-09-01

In spite of its importance for movements of the upper limbs, the clavicle is an infrequently studied shoulder bone. The present study compares clavicular morphology among different extant primates. Methods have included the assessment of clavicular curvatures projected on two perpendicular planes that can be assessed overall as cranial and dorsal primary curvatures. Results showed that in cranial view, three morphologies can be defined. One group exhibited an external curvature considerably more pronounced than the internal one (Gorilla, Papio); a second group was characterized by an internal curvature much more pronounced than the external one (Hylobates, Ateles); and a third group contained those with the two curvatures equally pronounced (Pan, Homo, Pongo, Procolobus, Colobus). Clavicle curvatures projected on the dorsal plane could be placed into four groups. The first group is characterized by two curvatures, an inferior and a superior (Apes, Spider monkeys). The second included monkeys, whose clavicles have an inferior curvature much more pronounced than the superior one. The third group includes only Hylobates, whose clavicles possess only the superior curvature. The last group includes only modern humans, whose clavicles show only the inferior curvature, which is less pronounced than that which exists in monkeys. Curvatures in cranial view relate information regarding the parameters of arm elevation while those in dorsal view offer insights into the position of the scapula related to the thorax. The use of clavicular curvature analysis offers a new dimension in assessment of the functional morphology of the clavicle and its relationship to the shoulder complex. (c) 2006 Wiley-Liss, Inc.

Immediate and long-term effects in the hematopoietic system and the morphology of the respiratory system in experimental animals under chronic combined action of external gamma exposure and inhalation exposure.

NASA Astrophysics Data System (ADS)

Tatarkin, Sergey; Moukhamedieva, Lana; Aleksandr, Shafirkin; Barantseva, Maria; Ivanova, Svetlana

The need to solve hygiene problems valuation of environmental factors in the implementation of the projected manned interplanetary missions, determined the relevance of studying the effect of external gamma-irradiation with inhalation of mixtures of chemicals on the parameters of major critical body systems: hematopoiesis and respiratory (morphological and morphometric parameters) in the short and long periods. The study conducted on 504 male mice F1 (CBA × C57BL6) under chronic fractional gamma-irradiation (within 10 weeks at a total dose 350sGr) and then under inhalation by mixtures of chemicals in low concentrations. Duration of the experiment (124 days) and 90 -day recovery period. Displaying adaptive reorganization in hematopoietic system, which was characterized by a tension of regulatory systems of animals and by a proliferation of bone marrow cells and by dynamic changes in amount of lymphoid cells in peripheral blood, elevated levels of the antioxidant activity of red blood cells, and morphological manifestations of "incomplete recovery " of the spleen, which are retained in the recovery period. Morphological changes in the respiratory organs of animals testified about immunogenesis activation and development of structural changes as a chronic inflammatory process. Increase of fibrous connective tissue in the walls of the trachea, bronchus and lung, against reduction of loose fibrous connective tissue (more pronounced in respiratory parts of the respiratory system) in experimental animals, which may indicate a reduction of the functional reserves of the body and increase the risk of adverse long-term effects.

Morphometric and genetic analysis of Arcella intermedia and Arcella intermedia laevis (Amoebozoa, Arcellinida) illuminate phenotypic plasticity in microbial eukaryotes.

PubMed

Porfírio-Sousa, Alfredo L; Ribeiro, Giulia M; Lahr, Daniel J G

2017-04-01

Testate amoebae are eukaryotic microorganisms characterized by the presence of an external shell (test). The shell morphology is used as a diagnostic character, but discordance between morphological and molecular data has been demonstrated in groups of arcellinids (Amoebozoa), one of the principal groups of testate amoebae. Morphology of the test is supposed to differentiate genera and species and it is applied in ecological, monitoring and paleontological studies. However, if phenotype does not reflect genotype, conclusions in these types of studies become severely impaired. The objective of this work is to evaluate the morphometrical and morphological variation of the closely related and morphologically similar taxa Arcella intermedia laevis Tsyganov and Mazei, 2006 and Arcella intermedia (Deflandre 1928) Tsyganov and Mazei, 2006 in nature and in cultured individuals and see how these are correlated with molecular data. Our results demonstrate that phenotypic plasticity in Arcella intermedia make morphological distinctions impossible in both taxa. Arcella intermedia and Arcella intermedia laevis are molecularly identical for SSU rDNA and a mitochondrial molecular marker (NAD9/7). We conclude that morphological techniques alone cannot identify phenotypic plasticity from natural populations. More work is clearly needed to better understand the morphological, morphometric and molecular variability in these organisms. Copyright © 2016 Elsevier GmbH. All rights reserved.

Large-scale wind-tunnel investigation of the noise characteristics of a semispan wing equipped with an externally blown jet flap

NASA Technical Reports Server (NTRS)

Falarski, M. D.

1972-01-01

A wind tunnel investigation was made of the noise characteristics of a 4.42 m(14.5 foot) semispan, externally-blown jet flap model. The model was equipped with a single 76.2 cm(30 inch) diameter, ducted fan with a 1.03 pressure ratio. The effects of flap size, fan vertical location, and forward speed on the noise characteristics were studied. The data from the investigation is presented in the form of tabulated one-third octave band frequency spectrums and perceived noise levels for each test condition.

Morphological and Phytochemical Diversity among Hypericum Species of the Mediterranean Basin

PubMed Central

Nürk, Nicolai M.; Crockett, Sara L.

2012-01-01

The genus Hypericum L. (St. John’s wort, Hypericaceae) includes more than 450 species that occur in temperature or tropical mountain regions of the world. Monographic work on the genus has resulted in the recognition and description of 36 taxonomic sections, delineated by specific combinations of morphological characteristics and biogeographic distribution. The Mediterranean Basin has been recognized as a hot spot of diversity for the genus Hypericum, and as such is a region in which many endemic species occur. Species belonging to sections distributed in this area of the world display considerable morphological and phytochemical diversity. Results of a cladistic analysis, based on 89 morphological characters that were considered phylogenetically informative, are given here. In addition, a brief overview of morphological characteristics and the distribution of pharmaceutically relevant secondary metabolites for species native to this region of the world are presented. PMID:22662020

Mineralogical, crystallographic and morphological characteristics of natural kaolins from the Ivory Coast (West Africa)

NASA Astrophysics Data System (ADS)

Sei, J.; Morato, F.; Kra, G.; Staunton, S.; Quiquampoix, H.; Jumas, J. C.; Olivier-Fourcade, J.

2006-10-01

Thirteen clay samples from four deposits in the Ivory Coast (West Africa) were studied using X-ray diffraction, thermogravimetric analysis and chemical analysis. Mineralogical, crystallographic and morphological characteristics of these samples are given. Kaolinite is the principal mineral but other minerals are present in small quantities: illite, quartz, anatase and iron oxides (oxides and oxyhydroxides). The crystallographic, morphological and surface characteristics are influenced by the presence of these impurities. In particular, the presence of iron oxides was associated with reduced structural ordering and thermal stability of kaolinite and increased specific surface area. These clays could be used in the ceramics industry to make tiles and bricks, and also in agronomy as supports for chemical fertilizers or for environmental protection by immobilising potentially toxic waste products.

Investigation of Thrust and Drag Characteristics of a Plug-type Exhaust Nozzle

NASA Technical Reports Server (NTRS)

Hearth, Donald P; Gorton, Gerald C

1954-01-01

An investigation was conducted in the 8- by 6-foot supersonic wind tunnel on the external and internal characteristics of a plug-type exhaust nozzle. Two positions of the center plug, one simulating a convergent nozzle and the other a convergent-divergent nozzle, were investigated. Data were obtained at free-stream Mach numbers of 0.1, 0.6, 1.6, and 2.0 over a pressure-ratio range of 1 to 20 and angles of attack of zero and 8 degrees. Results of this investigation indicated that the plug nozzle had thrust-minus-drag performance over the entire pressure-ratio range comparable with equivalent conventional nozzles. The effect of the exhaust jet on the external aerodynamics was similar to results observed for conventional nozzles. In addition, the thrust characteristics were generally insensitive to external flow and good agreement was noted with data obtained on comparable plug nozzles in quiescent air.

A theory of rotating stall of multistage axial compressors. III - Limit cycles

NASA Technical Reports Server (NTRS)

Moore, F. K.

1983-01-01

A theory of rotating stall, based on single parameters for blade-passage lag and external-flow lag and a given compressor characteristic yields limit cycles in velocity space. These limit cycles are governed by Lienard's equation with the characteristic playing the role of nonlinear damping function. Cyclic integrals of the solution determine stall propagation speed and the effect of rotating stall on average performance. Solution with various line-segment characteristics and various throttle settings are found and discussed. There is generally a limiting flow coefficient beyond which no solution is possible; this probably represents stall recovery. This recovery point is independent of internal compressor lag, but does depend on external lags and on the height-to-width ratio of the diagram. Tall diagrams and small external lags (inlet and diffusor) favor recovery. Suggestions for future theoretical and experimental research are discussed.

TEMHD Effects on Solidification Under Microgravity Conditions

NASA Technical Reports Server (NTRS)

Kao, Andrew; Pericleous, Koulis

2012-01-01

An unexplored potential exists to control microstructure evolution through the use of external DC magnetic fields. Thermoelectric currents form during solidification and interact with this external field to drive microscopic fluid dynamics within the inter-dendritic region. The convective heat and mass transport can lead to profound changes on the dendritic structure. In this paper the effect of high magnetic fields is demonstrated through the use of both 3-dimensional and 2-dimensional numerical models. The results show that the application of a magnetic field causes significant disruption to the dendritic morphology. Investigation into the underlying mechanism gives initial indicators of how external magnetic fields can either lead to unexpected growth behaviour, or alternatively can be used to control the evolution of microstructure in undercooled melts as encountered in levitated droplet solidification.

Evolution of external female genital mutilation: why do males harm their mates?

PubMed

Mouginot, Pierick; Uhl, Gabriele; Fromhage, Lutz

2017-11-01

Sperm competition may select for male reproductive traits that influence female mating or oviposition rate. These traits may induce fitness costs to the female; however, they may be costly for the males as well as any decrease in female fitness also affects male fitness. Male adaptations to sperm competition manipulate females by altering not only female behaviour or physiology, but also female morphology. In orb-weaving spiders, mating may entail mutilation of external structures of the female genitalia, which prevents genital coupling with subsequent males. Here, we present a game theoretical model showing that external female genital mutilation is favoured even under relatively high costs of mutilation, and that it is favoured by a high number of mate encounters per female and last-male sperm precedence.

Evolution of external female genital mutilation: why do males harm their mates?

PubMed Central

Uhl, Gabriele

2017-01-01

Sperm competition may select for male reproductive traits that influence female mating or oviposition rate. These traits may induce fitness costs to the female; however, they may be costly for the males as well as any decrease in female fitness also affects male fitness. Male adaptations to sperm competition manipulate females by altering not only female behaviour or physiology, but also female morphology. In orb-weaving spiders, mating may entail mutilation of external structures of the female genitalia, which prevents genital coupling with subsequent males. Here, we present a game theoretical model showing that external female genital mutilation is favoured even under relatively high costs of mutilation, and that it is favoured by a high number of mate encounters per female and last-male sperm precedence. PMID:29291104

Contextual amplification or attenuation of the impact of pubertal timing on Mexican-origin boys' mental health symptoms.

PubMed

White, Rebecca M B; Deardorff, Julianna; Liu, Yu; Gonzales, Nancy A

2013-12-01

To examine the role of neighborhood contextual variation in the putative association between pubertal timing and internalizing and externalizing symptoms among Mexican-origin boys. In a sample of seventh-grade Mexican-origin boys (N = 353; x¯age=12.8years) we assessed a range of secondary sexual characteristics, internalizing, and externalizing symptoms. Reports on all secondary sexual characteristics were collapsed and age-standardized to represent total pubertal timing. We also distinguished between the timing of physical changes driven by adrenal versus gonadal maturation. Boys' residential addresses were geocoded and American Community Survey data were used to describe neighborhoods along two dimensions: ethnic concentration and socioeconomic disadvantage. Three years later (in 10th grade) we re-assessed internalizing and externalizing symptoms. We examined the moderating influence of neighborhood ethnic concentration and neighborhood socioeconomic disadvantage on the prospective associations between puberty timing (total, gonadal, adrenal) and internalizing and externalizing symptoms. Earlier total pubertal timing predicted increases in externalizing symptoms, but only when Mexican-origin boys lived in neighborhoods low on ethnic concentration. Total timing results for externalizing symptoms were replicated for adrenal timing. Furthermore, early adrenal timing predicted increases in internalizing symptoms, but again, only when boys lived in neighborhoods low on ethnic concentration. No effects were observed for gonadal timing specifically. Early pubertal timing, especially advanced physical changes initiated and regulated by adrenal maturation, have important implications for Mexican-origin boys' internalizing and externalizing symptoms, but these implications depend on neighborhood characteristics. Ethnically concentrated neighborhoods are protective for early-maturing Mexican-origin boys. Copyright © 2013 Society for Adolescent Health and Medicine. Published by Elsevier Inc. All rights reserved.

Identification of gender in yellow perch Perca flavescens using external morphology

USDA-ARS?s Scientific Manuscript database

A non-lethal and rapid method for reliable identification of gender in yellow perch has been developed. On average, yellow perch females grow faster than males and undergo sexual maturity at an earlier age. Such size discrepancies in mixed culture situations pose difficulties with aquaculture produc...

The Modification of Compounds by Attributive Adjectives

ERIC Educational Resources Information Center

Berg, Thomas

2011-01-01

This paper examines the modification of nominal compounds by attributive adjectives in English. It draws on a distinction between compound-external (i.e. syntactic) and compound-internal (i.e. morphological) modification. An analysis is presented of more than 1000 pertinent cases, which are roughly equally divided into two-, three- and four-noun…

Identification normal external and internal bacteria and fungi in larvae and pupae Papilio polyetes

NASA Astrophysics Data System (ADS)

Sanjaya, Y.; Suhara; Nurjhani, M.

2018-05-01

Interaction between insects and microorganism has been occurring thousands years ago. The numerous ones are bacteria that live inside insect, but there are possibility also to finding other microorganisms like fungus. It can be becoming a good atmosphere. It is also indicating healthy of an insect. If there were existing foreign microbiota, it can be concluded that the insect was sick. The Methods of this research are examining bacteria external and internal with Nutrient Agar (NA) as Media under following the method of Caoili (2003) with investigating external, fore gut, mid gut and hind gut. The result showed that weather in larvae 5th of Papilio polyetes and its pupae on external examine. The appearance of bacteria gram + were more numerous than gram ‑ one. While in the fore gut, mid gut and fore gut were dominated by bacteria gram+, its correlated with the fact that its alkaline. Their presence influenced by habitat, morphology and feeding habits. The conclusion the simbiosism existence between P. polyetes with external and internal microfloral appear to assist from protection and metabolism process.

Ultrastructural Characteristics of the Testis, Spermatogenesis and Taxonomic Values of Sperm Morphology in Male Ruditapes philippinarum in Western Korea.

PubMed

Kim, Jin Hee; Chung, Jae Seung; Lee, Ki-Young

2013-06-01

Ultrastructural characteristics of the germ cells and accessory cells in testis during spermatogenesis and taxonomic values of mature sperm morphology of Ruditapes philippinarum were investigated by the transmission electron microscope and scanning electron microscope observations. The testis is the diffuse organ that consists of branching acini containing developing germ cells and accessory cells associated with spermatogenesis. The morphology of the spermatozoon is of the primitive type and is somewhat different to those of other bivalves. The morphologies of the sperm nucleus type and the acrosome shape of this species have a cylinderical type and a modified cone shape, respectively. As some ultrastructural characteristics of the acrosomal vesicle, the peripheral parts of two basal rings show electron opaque part, while the apex part of the acrosome shows electron lucent part. These characteristics of sperm belong to the family Veneridae in the subclass Heterodonta, unlike a characteristic of the subclass Pteriomorphia showing all part of the acrosome being composed of electron opaque part. In particular, a cylinder-like nucleus of the sperm is curved. The spermatozoon is approximately 48-51 μm in length, including a long acrosome (about 2.40 μm in length), a curved sperm nucleus (about 3.40 μm in length), and a tail flagellum. The axoneme of the sperm tail shows a 9+2 structure.

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

PubMed

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

2012-04-01

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

Vertical Vibration Characteristics of a High-Temperature Superconducting Maglev Vehicle System

NASA Astrophysics Data System (ADS)

Jiang, Jing; Li, Ke Cai; Zhao, Li Feng; Ma, Jia Qing; Zhang, Yong; Zhao, Yong

2013-06-01

The vertical vibration characteristics of a high-temperature superconducting maglev vehicle system are investigated experimentally. The displacement variations of the maglev vehicle system are measured with different external excitation frequency, in the case of a certain levitation gap. When the external vibration frequency is low, the amplitude variations of the response curve are small. With the increase of the vibration frequency, chaos status can be found. The resonance frequencies with difference levitation gap are also investigated, while the external excitation frequency range is 0-100 Hz. Along with the different levitation gap, resonance frequency is also different. There almost is a linear relationship between the levitation gap and the resonance frequency.

Characteristics of the Single-Longitudinal-Mode Planar-Waveguide External Cavity Diode Laser at 1064 nm

NASA Technical Reports Server (NTRS)

Numata, Kenji; Alalusi, Mazin; Stolpner, Lew; Margaritis, Georgios; Camp, Jordan B.; Krainak, Michael A.

2014-01-01

We describe the characteristics of the planar-waveguide external cavity diode laser (PW-ECL). To the best of our knowledge, it is the first butterfly-packaged 1064-nm semiconductor laser that is stable enough to be locked to an external frequency reference. We evaluated its performance from the viewpoint of precision experiments. Especially, using a hyperfine absorption line of iodine, we suppressed its frequency noise by a factor of up to104 at 10 mHz. The PW-ECLs compactness and low cost make it a candidate to replace traditional Nd:YAGnon-planar ring oscillators and fiber lasers in applications which require a single longitudinal-mode.

Involvement of upper torso stress amplification, tissue compression and distortion in the pathogenesis of keloids.

PubMed

Bux, Shamin; Madaree, Anil

2012-03-01

Keloids are benign tumours composed of fibrous tissue produced during excessive tissue repair triggered by minor injury, trauma or surgical incision. Although it is recognized that keloids have a propensity to form in the upper torso of the body, the predisposing factors responsible for this have not been investigated. It is crucial that the aetiopathoical factors implicated in keloid formation be established to provide guidelines for well-informed more successful treatment. We compared keloid-prone and keloid-protected skin, identified pertinent morphological differences and explored how inherent structural characteristics and intrinsic factors may promote keloid formation. It was determined that keloid prone areas were covered with high tension skin that had low stretch and a low elastic modulus when compared with skin in keloid protected areas where the skin was lax with a high elastic modulus and low pre-stress level. Factors contributing to elevated internal stress in keloid susceptible skin were the protrusion of hard connective tissue such as bony prominences or cartilage into the dermis of skin as well as inherent skin characteristics such as the bundled arrangement of collagen in the reticular dermis, the existent high tension, the low elastic modulus, low stretch ability, contractile forces exerted by wound healing fibroblastic cells and external forces. Stress promotes keloid formation by causing dermal distortion and compression which subsequently stimulate proliferation and enhanced protein synthesis in wound healing fibroblastic cells. The strain caused by stress also compresses and occludes microvessels causing ischaemic effects and reperfusion injury which stimulate growth when blood rich in growth factors returns to the tissue. The growth promoting effects of increased internal stress, primarily, and growth factors released by reperfusing blood, manifest in keloid formation. Other inherent skin characteristics promoting keloid growth during the late stages of wound healing in the upper torso are the thinner epidermis, the presence of vellus hairs, the absence of protective immunoglobulin A (IgA), and the thick fragile quality of upper torso skin. As it is not known why there is a predilection for keloids to form in the upper torso of the body, this hypothesis implicating and associating inherent morphological characteristics and elevated stress in the aetiopathogenesis of keloids is of potential value in terms of prevention, management and treatment of these enigmatic tumours. Copyright © 2011 Elsevier Ltd. All rights reserved.

Scedosporium inflatum, an emerging pathogen.

PubMed Central

Salkin, I F; McGinnis, M R; Dykstra, M J; Rinaldi, M G

1988-01-01

The salient morphologic and physiologic characteristics of 18 isolates of Scedosporium inflatum, a newly reported human pathogen, were compared with those of the morphologically similar fungi Scedosporium apiospermum, Scopulariopsis brevicaulis, and Scopulariopsis brumptii. The formation by S. inflatum of annelloconidia in wet clumps at the apices of annellides with swollen bases was found to be the most useful characteristic in differentiating this potential pathogen. Images PMID:3356789

Syndromes associated with Homo sapiens pol II regulatory genes.

PubMed

Bina, M; Demmon, S; Pares-Matos, E I

2000-01-01

The molecular basis of human characteristics is an intriguing but an unresolved problem. Human characteristics cover a broad spectrum, from the obvious to the abstract. Obvious characteristics may include morphological features such as height, shape, and facial form. Abstract characteristics may be hidden in processes that are controlled by hormones and the human brain. In this review we examine exaggerated characteristics presented as syndromes. Specifically, we focus on human genes that encode transcription factors to examine morphological, immunological, and hormonal anomalies that result from deletion, insertion, or mutation of genes that regulate transcription by RNA polymerase II (the Pol II genes). A close analysis of abnormal phenotypes can give clues into how sequence variations in regulatory genes and changes in transcriptional control may give rise to characteristics defined as complex traits.

Parental Child-Rearing Conflicts Through Adolescence: Trajectories and Associations With Child Characteristics and Externalizing Patterns.

PubMed

Helland, Maren S; Kjeldsen, Anne; von Soest, Tilmann; Røysamb, Espen; Gustavson, Kristin; Nilsen, Wendy

2017-06-01

Research on longitudinal interparental conflict patterns and offspring development is scarce. The population-based TOPP study (N = 459) was used to investigate (1) child-rearing conflict trajectories through four time points during childhood and adolescence (ages 8-16), and (2) associations between conflict trajectories and child characteristics (i.e., birth order, gender, externalizing patterns from early childhood). Latent profile analysis identified six distinct trajectories. Conflict levels decreased for most respondents over the adolescent offspring period, but offspring's birth order and externalizing problems were related to less typical trajectories and higher levels of conflict. Onset of externalizing problems was of additional importance for the course of parental child-rearing conflicts. The results highlight the perception of the whole family as an interwoven system. © 2017 The Authors. Journal of Research on Adolescence © 2017 Society for Research on Adolescence.

Clinical Characteristics of Pediatric Trichotillomania: Comparisons with Obsessive-Compulsive and Tic Disorders.

PubMed

Rozenman, Michelle; Peris, Tara S; Gonzalez, Araceli; Piacentini, John

2016-02-01

This study compared youth ages 5-17 years with a primary diagnosis of trichotillomania (TTM, n = 30) to those with primary OCD (n = 30) and tic disorder (n = 29) on demographic characteristics, internalizing, and externalizing symptoms. Findings suggest that youth with primary TTM score more comparably to youth with tics than those with OCD on internalizing and externalizing symptom measures. Compared to the OCD group, youth in the TTM group reported lower levels of anxiety and depression. Parents of youth in the TTM group also reported fewer internalizing, externalizing, attention, and thought problems than those in the OCD group. Youth with TTM did not significantly differ from those with primary Tic disorders on any measure. Findings suggest that pediatric TTM may be more similar to pediatric tic disorders than pediatric OCD on anxiety, depression, and global internalizing and externalizing problems.

Changes in erosional style on early Mars - External versus internal influences

NASA Technical Reports Server (NTRS)

Postawko, Susan E.; Fanale, Fraser P.

1993-01-01

A quantitative relationship is derived between the effectiveness of an atmospheric greenhouse and that of internal heat flow in producing the morphological differences between early and later Martian terrains. The derived relationship is used for two purposes: (1) to evaluate the relative importance of the atmospheric CO2 greenhouse effect and the internal regolith thermal gradient in producing morphological changes for any value of the heat flow (and conductivity values); and (2) to assess the absolute importance of each for specific values of the heat flow which are thought to be reasonable on independent geophysical grounds.

Quantitative determination for cytotoxic Friedo-nor-oleanane derivatives from five morphological types of Maytenus ilicifolia (Celastraceae) by reverse-phase high-performance liquid chromatography.

PubMed

Buffa Filho, Waldemar; Corsino, Joaquim; Bolzani, da Silva Vanderlan; Furlan, Maysa; Pereira, Ana Maria S; França, Suzelei Castro

2002-01-01

Five different morphological types of Maytenus ilicifolia of the same age and harvested under the same conditions showed distinct accumulations of some friedo-nor-oleananes. A rapid, sensitive and reliable reverse-phase HPLC method (employing an external standard) was used for the determination of the cytotoxic triterpenoids, 20 alpha-hydroxymaytenin, 22 beta-hydroxymaytenin, maytenin, celastrol and pristimerin in each of the five types. Well resolved peaks with good detection response and linearity in the range 1.0-100 micrograms/mL were obtained.

Fatigue tests of YBCO coated conductors

NASA Astrophysics Data System (ADS)

Bamba, S.; Tanaka, Y.; Ando, T.; Ueda, H.; Ishiyama, A.; Yamada, Y.; Shiohara, Y.

2008-02-01

In this paper, we report the fatigue characteristics of IBAD/PLD YBCO coated conductors. A YBCO coated conductor used in the superconducting coil of a SMES system is repeatedly subjected to mechanical tensile or compressive strain due to the Lorentz force during electrical charging or discharging. The superconducting characteristic of this conductor may deteriorate because of this cyclic strain. Therefore, it is necessary to investigate the effect of cyclic strain on the superconducting characteristics of YBCO coated conductors that have a laminated structure. We developed an experimental apparatus with a U-shaped sample holder in order to apply cyclic strain to the sample tape. This apparatus was used to perform the fatigue tests on YBCO coated conductors in liquid nitrogen in the absence of an external magnetic field. The strain cycles with the maximum strain epsilonmax (zero external strain → epsilonmax → zero external strain) were applied and repeated up to 5000 times, and the Ic measurements were performed at epsilonmax. Therefore, the application of cyclic strain with epsilonmax ranging from 0.3% to 0.5% did not result in any significant deterioration of the superconducting characteristics of the conductor.

External morphogenesis of the tardigrade Hypsibius dujardini as revealed by scanning electron microscopy.

PubMed

Gross, Vladimir; Minich, Irene; Mayer, Georg

2017-04-01

Tardigrada, commonly called water bears, is a taxon of microscopic panarthropods with five-segmented bodies and four pairs of walking legs. Although tardigrades have been known to science for several centuries, questions remain regarding many aspects of their biology, such as embryogenesis. Herein, we used scanning electron microscopy to document the external changes that occur during embryonic development in the tardigrade Hypsibius dujardini (Eutardigrada, Parachela, Hypsibiidae). Our results show an accelerated development of external features, with approximately 30 hrs separating the point at which external structures first become recognizable and a fully formed embryo. All segments appear to arise simultaneously between ∼20 and 25 hrs of development, and no differences in the degree of development could be detected between the limb buds at any stage. Claws emerge shortly after the limb buds and are morphologically similar to those of adults. The origin of the claws is concurrent with that of the sclerotized parts of the mouth, suggesting that all cuticular structures arise simultaneously at ∼30 hrs. The mouth arises as an invagination in the terminal region of the head at ∼25 hrs, closes later in development, and opens again shortly before hatching. The anlagen of the peribuccal lobes arise as one dorsal and one ventral row, each consisting of three lobes, and later form a ring in the late embryo, whereas there is no indication of a labrum anlage at any point during development. Furthermore, we describe limited postembryonic development in the form of cuticular pores that are absent in juveniles but present in adults. This study represents the first scanning electron micrographs of tardigrade embryos, demonstrating the utility of this technique for studying embryogenesis in tardigrades. This work further adds an external morphological perspective to the developmental data already available for H. dujardini, facilitating future comparisons to related panarthropod taxa. J. Morphol. 278:563-573, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

The production and growth characteristics of yeast and mycelial forms of Candida albicans in continuous culture.

PubMed

Shepherd, M G; Sullivan, P A

1976-04-01

The growth characteristics of Candida albicans CM145,348 have been examined under aerobic conditions in continuous culture. At different steady states the environment was controlled with respect to the concentrations of dissolved oxygen, carbon and nitrogen, the pH, and the temperature. Dry matter, substrate concentration, yield, specific oxygen uptake, specific carbon dioxide release and respiration quotient were examined as a function of the dilution rate. The morphology depended on the carbon source. Maltose produced a mycelial morphology, whereas with lactate a yeast culture was obtained. With fructose or glucose as a carbon source a mixed morphology of yeast, pseudo-mycelial and mycelial forms was produced. A larger number of different growth conditions were examined in batch culture but a mixed morphology was always obtained.

The relation between umbilical cord characteristics and the outcome of external cephalic version.

PubMed

Kuppens, Simone M I; Waerenburgh, Evelyne R; Kooistra, Libbe; van der Donk, Riet W P; Hasaart, Tom H M; Pop, Victor J M

2011-05-01

Umbilical cords of fetuses in breech presentation differ in length and coiling from their cephalic counterparts and it might be hypothesised that these cord characteristics may in turn affect ECV outcome. To investigate the relation between umbilical cord characteristics and the outcome of external cephalic version (ECV). Prospective cohort study. Women (>35 weeks gestation) with a singleton fetus in breech presentation, suitable for external cephalic version. Demographic, lifestyle and obstetrical parameters were assessed at intake. ECV success was based on cephalic presentation on ultrasound post-ECV. Umbilical cord length (UCL) and umbilical coiling index (UCI) were measured after birth. The relation between umbilical cord characteristics (cord length and coiling) and the success of external cephalic version. ECV success rate was overall 79/146 (54%), for multiparas 37/46(80%) and for nulliparas 42/100 (42%). Multiple logistic regression showed that UCL (OR: 1.04, CI: 1.01-1.07), nulliparity (OR: 0.20, CI: 0.08-0.51), frank breech (OR: 0.37, 95% CI: 0.15-0.90), body mass index (OR: 0.85, CI: 0.76-0.95), placenta anterior (OR: 0.27, CI: 0.12-0.63) and birth weight (OR: 1.002, CI: 1.001-1.003) were all independently related to ECV success. Umbilical cord length is independently related to the outcome of ECV, whereas umbilical coiling index is not. Copyright © 2011 Elsevier Ltd. All rights reserved.

Introducing external cephalic version in a Malaysian setting.

PubMed

Yong, Stephen P Y

2007-02-01

To assess the outcome of external cephalic version for routine management of malpresenting foetuses at term. Prospective observational study. Tertiary teaching hospital, Malaysia. From September 2003 to June 2004, a study involving 41 pregnant women with malpresentation at term was undertaken. An external cephalic version protocol was implemented. Data were collected for identifying characteristics associated with success or failure of external cephalic version. Maternal and foetal outcome measures including success rate of external cephalic version, maternal and foetal complications, and characteristics associated with success or failure; engagement of presenting part, placental location, direction of version, attempts at version, use of intravenous tocolytic agent, eventual mode of delivery, Apgar scores, birth weights, and maternal satisfaction with the procedure. Data were available for 38 women. External cephalic version was successful in 63% of patients; the majority (75%) of whom achieved a vaginal delivery. Multiparity (odds ratio=34.0; 95% confidence interval, 0.67-1730) and high amniotic fluid index (4.9; 1.3-18.2) were associated with successful external cephalic version. Engagement of presenting part (odds ratio=0.0001; 95% confidence interval, 0.00001-0.001) and a need to resort to backward somersault (0.02; 0.00001-0.916) were associated with poor success rates. Emergency caesarean section rate for foetal distress directly resulting from external cephalic version was 8%, but there was no perinatal or maternal adverse outcome. The majority (74%) of women were satisfied with external cephalic version. External cephalic version has acceptable success rates. Multiparity, liquor volume, engagement of presenting part, and the need for backward somersault were strong predictors of outcome. External cephalic version is relatively safe, simple to learn and perform, and associated with maternal satisfaction. Modern obstetric units should routinely offer the procedure.

Nonsphericity Index and Size Ratio Identify Morphologic Differences between Growing and Stable Aneurysms in a Longitudinal Study of 93 Cases.

PubMed

Chien, A; Xu, M; Yokota, H; Scalzo, F; Morimoto, E; Salamon, N

2018-01-25

Recent studies have strongly associated intracranial aneurysm growth with increased risk of rupture. Identifying aneurysms that are likely to grow would be beneficial to plan more effective monitoring and intervention strategies. Our hypothesis is that for unruptured intracranial aneurysms of similar size, morphologic characteristics differ between aneurysms that continue to grow and those that do not. From aneurysms in our medical center with follow-up imaging dates in 2015, ninety-three intracranial aneurysms (23 growing, 70 stable) were selected. All CTA images for the aneurysm diagnosis and follow-up were collected, a total of 348 3D imaging studies. Aneurysm 3D geometry for each imaging study was reconstructed, and morphologic characteristics, including volume, surface area, nonsphericity index, aspect ratio, and size ratio were calculated. Morphologic characteristics were found to differ between growing and stable groups. For aneurysms of <3 mm, nonsphericity index ( P < .001); 3-5 mm, nonsphericity index ( P < .001); 5-7 mm, size ratio ( P = .003); >7 mm, volume ( P < .001); surface area ( P < .001); and nonsphericity index ( P = .002) were significant. Within the anterior communicating artery, the nonsphericity index ( P = .008) and, within the posterior communicating artery, size ratio ( P = .004) were significant. The nonsphericity index receiver operating characteristic area under the curve was 0.721 for discriminating growing and stable cases on the basis of initial images. Among aneurysms with similar sizes, morphologic characteristics appear to differ between those that are growing and those that are stable. The nonsphericity index, in particular, was found to be higher among growing aneurysms. The size ratio was found to be the second most significant parameter associated with growth. © 2018 by American Journal of Neuroradiology.

Arundina graminifolia var. revoluta (Arethuseae, Orchidaceae) has fern-type rheophyte characteristics in the leaves.

PubMed

Yorifuji, Eri; Ishikawa, Naoko; Okada, Hiroshi; Tsukaya, Hirokazu

2015-03-01

Morphological and molecular variation between Arundina graminifolia var. graminifolia and the dwarf variety, A. graminifolia var. revoluta, was examined to assess the validity of their taxonomic characteristics and genetic background for identification. Morphological analysis in combination with field observations indicated that A. graminifolia var. revoluta is a rheophyte form of A. graminifolia characterized by narrow leaves, whereas the other morphological characteristics described for A. graminifolia var. revoluta, such as smaller flowers and short stems, were not always accompanied by the narrower leaf phenotype. Molecular analysis based on matK sequences indicated that only partial differentiation has occurred between A. graminifolia var. graminifolia and A. graminifolia var. revoluta. Therefore, we should consider the rheophyte form an ecotype rather than a variety. Anatomical observations of the leaves revealed that the rheophyte form of A. graminifolia possessed characteristics of the rheophytes of both ferns and angiosperms, such as narrower palisade tissue cells and thinner spongy tissue cells, as well as fewer cells in the leaf-width direction and fewer mesophyll cell layers.

Performance evaluation of a dynamic telepathology system (Panoptiq™) in the morphologic assessment of peripheral blood film abnormalities.

PubMed

Goswami, R; Pi, D; Pal, J; Cheng, K; Hudoba De Badyn, M

2015-06-01

The study evaluated the performance of a dynamic imaging telepathology system (Panoptiq(™) ) as a diagnostic aid to the identification of peripheral blood film (PBF) abnormalities. The study assumed a laboratory personnel working in a clinical laboratory were operating the telepathology system to seek diagnostic opinion from an external consulting hematopathologist. The study examined 100 blood films, encompassing 23 different hematological diseases, reactive or normal cases. The study revealed that with real-time image transmission in live scanning mode of operation, the telepathology system was able to aid reviewers in achieving excellent accuracy, that is correct interpretation of morphologic abnormalities obtained in 83/84 of the hematologic diseases and 12/12 of the reactive/normal conditions (Sensitivity: 0.99; Specificity: 1.00). In contrast, when only saved static images in digital capture mode of operation were reviewed remotely, interpretative omissions occurred in 8/84 of the hematologic diseases and 0/12 of the reactive/normal conditions (Sensitivity: 0.91; Specificity: 1.00). It is hypothesized that real-time operator-reviewer communication during live scanning played an important role in the identification of key morphologic abnormalities for review. Our study showed the Panoptiq system can be adopted reliably as a dynamic telepathology tool in aiding community laboratories in the triage of PBF cases for external diagnostic consultation. © 2014 John Wiley & Sons Ltd.

Root canal morphology of primary molars: a micro-computed tomography study.

PubMed

Fumes, A C; Sousa-Neto, M D; Leoni, G B; Versiani, M A; da Silva, L A B; da Silva, R A B; Consolaro, A

2014-10-01

This was to investigate the root canal morphology of primary molar teeth using micro-computed tomography. Primary maxillary (n = 20) and mandibular (n = 20) molars were scanned at a resolution of 16.7 μm and analysed regarding the number, location, volume, area, structured model index (SMI), area, roundness, diameters, and length of canals, as well as the thickness of dentine in the apical third. Data were statistically compared by using paired-sample t test, independent sample t test, and one-way analysis of variance with significance level set as 5%. Overall, no statistical differences were found between the canals with respect to length, SMI, dentine thickness, area, roundness, and diameter (p > 0.05). A double canal system was observed in the mesial and mesio-buccal roots of the mandibular and maxillary molars, respectively. The thickness in the internal aspect of the roots was lower than in the external aspect. Cross-sectional evaluation of the roots in the apical third showed flat-shaped canals in the mandibular molars and ribbon- and oval-shaped canals in the maxillary molars. External and internal anatomy of the primary first molars closely resemble the primary second molars. The reported data may help clinicians to obtain a thorough understanding of the morphological variations of root canals in primary molars to overcome problems related to shaping and cleaning procedures, allowing appropriate management strategies for root canal treatment.

Systematics of Ecnomiohyla tuberculosa with the description of a new species and comments on the taxonomy of Trachycephalus typhonius (Anura, Hylidae).

PubMed

Ron, Santiago R; Venegas, Pablo J; Ortega-Andrade, H Mauricio; Gagliardi-Urrutia, Giussepe; Salerno, Patricia E

2016-01-01

Ecnomiohyla tuberculosa is an Amazonian hylid of uncertain phylogenetic position. Herein DNA sequences of mitochondrial and nuclear genes are used to determine its phylogenetic relationships. New sequences and external morphology of Trachycephalus typhonius are also analyzed to assess the status of Ecuadorian and Peruvian populations. The phylogeny shows unequivocally that Ecnomiohyla tuberculosa is nested within the genus Tepuihyla , tribe Lophiohylini. This position was unexpected because the remaining species of Ecnomiohyla belong to the tribe Hylini. To solve the paraphyly of the genus Ecnomiohyla , Ecnomiohyla tuberculosa is transferred to the genus Tepuihyla . Comparisons of DNA sequences, external morphology, and advertisement calls between populations of Ecnomiohyla tuberculosa from Ecuador and Peru indicate that the Peruvian population represents an undescribed species. The new species is described and a species account is provided for Ecnomiohyla tuberculosa . Trachycephalus typhonius is paraphyletic relative to Trachycephalus cunauaru , Trachycephalus hadroceps , and Trachycephalus resinifictrix . The phylogenetic position of populations from western Ecuador indicates that they represent a species separate from Trachycephalus typhonius sensu stricto . We resurrect the name Hyla quadrangulum ( Trachycephalus quadrangulum comb. n. ) for those populations. Amazonian populations of " Trachycephalus typhonius " from Ecuador and Peru are genetically and morphologically distinct from Trachycephalus typhonius sensu stricto and are conspecific with the holotype of Hyla macrotis . Therefore, we also resurrect Hyla macrotis , a decision that results in Trachycephalus macrotis comb. n.

Systematics of Ecnomiohyla tuberculosa with the description of a new species and comments on the taxonomy of Trachycephalus typhonius (Anura, Hylidae)

PubMed Central

Ron, Santiago R.; Venegas, Pablo J.; Ortega-Andrade, H. Mauricio; Gagliardi-Urrutia, Giussepe; Salerno, Patricia E.

2016-01-01

Abstract Ecnomiohyla tuberculosa is an Amazonian hylid of uncertain phylogenetic position. Herein DNA sequences of mitochondrial and nuclear genes are used to determine its phylogenetic relationships. New sequences and external morphology of Trachycephalus typhonius are also analyzed to assess the status of Ecuadorian and Peruvian populations. The phylogeny shows unequivocally that Ecnomiohyla tuberculosa is nested within the genus Tepuihyla, tribe Lophiohylini. This position was unexpected because the remaining species of Ecnomiohyla belong to the tribe Hylini. To solve the paraphyly of the genus Ecnomiohyla, Ecnomiohyla tuberculosa is transferred to the genus Tepuihyla. Comparisons of DNA sequences, external morphology, and advertisement calls between populations of Ecnomiohyla tuberculosa from Ecuador and Peru indicate that the Peruvian population represents an undescribed species. The new species is described and a species account is provided for Ecnomiohyla tuberculosa. Trachycephalus typhonius is paraphyletic relative to Trachycephalus cunauaru, Trachycephalus hadroceps, and Trachycephalus resinifictrix. The phylogenetic position of populations from western Ecuador indicates that they represent a species separate from Trachycephalus typhonius sensu stricto. We resurrect the name Hyla quadrangulum (Trachycephalus quadrangulum comb. n.) for those populations. Amazonian populations of “Trachycephalus typhonius” from Ecuador and Peru are genetically and morphologically distinct from Trachycephalus typhonius sensu stricto and are conspecific with the holotype of Hyla macrotis. Therefore, we also resurrect Hyla macrotis, a decision that results in Trachycephalus macrotis comb. n. PMID:27917043

Neighborhood Variation of Sustainable Urban Morphological Characteristics.

PubMed

Lai, Poh-Chin; Chen, Si; Low, Chien-Tat; Cerin, Ester; Stimson, Robert; Wong, Pui Yun Paulina

2018-03-07

Compact cities and their urban forms have implications on sustainable city development because of high density urban settlement, increased accessibility, and a balanced land use mix. This paper uses quantitative means of understanding urban morphological characteristics with reference to the differing qualities of the urban form (i.e., street patterns, building volumes, land uses and greenery). The results, based on 89 neighborhood communities of Hong Kong, show varying degrees of regional differences in the urban built form supported by numerical statistics and graphical illustrations. This paper offers empirical evidence on some morphological characteristics that can be estimated objectively using modern geospatial technologies and applied universally to inform urban planning. However, more studies linking these quantifiable measures of the physical form with sustainable urban living are needed to account for human comfort in the totality of environmental, social, and economic responsibilities.

Neighborhood Variation of Sustainable Urban Morphological Characteristics

PubMed Central

Chen, Si; Stimson, Robert

2018-01-01

Compact cities and their urban forms have implications on sustainable city development because of high density urban settlement, increased accessibility, and a balanced land use mix. This paper uses quantitative means of understanding urban morphological characteristics with reference to the differing qualities of the urban form (i.e., street patterns, building volumes, land uses and greenery). The results, based on 89 neighborhood communities of Hong Kong, show varying degrees of regional differences in the urban built form supported by numerical statistics and graphical illustrations. This paper offers empirical evidence on some morphological characteristics that can be estimated objectively using modern geospatial technologies and applied universally to inform urban planning. However, more studies linking these quantifiable measures of the physical form with sustainable urban living are needed to account for human comfort in the totality of environmental, social, and economic responsibilities. PMID:29518956

Quantitative Analysis and Development of the Fore Feet of Arabian Foals from Birth to 1 Year of Age.

PubMed

Faramarzi, Babak; Salinger, Allison; Kaneps, Andris; Nout-Lomas, Yvette; Greene, Holly; Dong, Fanglong

2017-11-01

Objectives  The goal of this study was to quantify external and internal anatomical characteristics of the foal foot throughout the first year of age. Methods  Digital radiographs and photographs were taken bimonthly of the forefeet of nine Arabian foals, beginning at about 2 weeks of age until 12 months of age. Sixty-eight linear and angular variables were measured using NIH (National Institutes of Health) Image J software. Statistical analyses were performed using piecewise random coefficient model and p -values < 0.05 were considered significant. Results  Distinct changes in hoof development were identified between 4 and 8 months of age. Distinct changes were identified in several external (conformational) measurements including hoof solar widths and lengths, palmar heel lengths, toe and heel angles and in several internal (radiographic) measurements including the widths and lengths of the phalanges and sesamoid bones as well as joint angles. Clinical Significance  Existing knowledge of distal limb development in foals, particularly the foot, is limited. These findings define the measurable changes of the foal foot as it grows during the first year of life. These data provide an insight into the transformation of the hoof from its initial oval to a circular shape and from a club-like, cylindrical conformation to a more angled, conical conformation. This paper quantifies this development, ultimately allowing a better understanding of morphological changes in the foot of the growing foal. Schattauer GmbH Stuttgart.

Optical properties of monolayer polystyrene microspheres driven by a direct current

NASA Astrophysics Data System (ADS)

Jiao, Xinbing; Pan, Qian; Zhao, Xinwei; Hao, Ruirui; Bai, Xue

2018-04-01

Polystyrene microspheres (PSMs) with diameters of 5 μm and 10 μm are prepared on garnet by a self-assembly method. The pressure generated by quartz sheet/PSM/garnet/graphite is measured by a resistance strain sensor as a function of the external direct current (DC) voltage. The surface morphology of the PSMs are observed by optical microscopy. The polarization properties of the linearly and circularly polarized laser beams with a wavelength of 1550 nm reflected from the different PSMs are researched by a Thorlabs PAX 5710 IR3 Polarization Analyzing System as a function of the external DC voltage. The results show that the PSMs with different sizes can be damaged when the external pressure exceeds its critical value of 3.0 MPa, but the critical DC voltages are different. The optical polarization properties of the circularly polarized laser beam can be changed with the external DC voltage, whereas the linearly polarized laser beam cannot be changed.

Embryonic and fetal morphology in the lowland paca (Cuniculus paca): A precocial hystricomorph rodent.

PubMed

El Bizri, Hani Rocha; Monteiro, Frederico Ozanan Barros; de Andrade, Rafael Dos Santos; Valsecchi, João; Guimarães, Diva Anelie de Araújo; Mayor, Pedro

2017-12-01

In mammals, the embryonic and fetal development of a species has evolved to maximize neonatal survival. In this study, we use a sample of 132 embryos/fetuses of wild lowland paca (Cuniculus paca), obtained over a period of 15 years through collaborative methods with local hunters in the Amazon to describe the intrauterine development of external and internal morphology of this Neotropical rodent. We also compare the newborn survival strategy in this species with other rodents. The crown-rump length (CRL) ranged between 0.6 and 24.6 cm. External features appeared in the following chronological order: limbs, eyelid buds, fusioned eyelids, genitalia, outer ear, tactile pelage, claws, skin, skin spots, covering pelage, teeth and open eyelids. Fetuses with CRL >19.5 cm presented all external features fully developed. The growth formula of fetal age was calculated as ∛W = 0.082 (t - 37.25), and age was accurately associated with CRL. We described the relationship between CRL and external and internal biometry. The liver declined in proportion within the internal cavity, while the relative volume of tubular gastrointestinal organs increased significantly along the embryo/fetal development. All organs, except the heart and the thymus, had similar relative volumes in advanced fetuses and adults. Our comparison of the intrauterine development in several rodent species indicates that the paca's reproductive strategy is comparable to species that are subject to low natural predation. Given that C. paca is perhaps the most hunted animal in Latin America, sustainable hunting throughout its range must take into account its relative reproductive performance. Copyright © 2017 Elsevier Inc. All rights reserved.

Skeletal Morphology of Opius dissitus and Biosteres carbonarius (Hymenoptera: Braconidae), with a Discussion of Terminology

PubMed Central

Karlsson, Dave; Ronquist, Fredrik

2012-01-01

The Braconidae, a family of parasitic wasps, constitute a major taxonomic challenge with an estimated diversity of 40,000 to 120,000 species worldwide, only 18,000 of which have been described to date. The skeletal morphology of braconids is still not adequately understood and the terminology is partly idiosyncratic, despite the fact that anatomical features form the basis for most taxonomic work on the group. To help address this problem, we describe the external skeletal morphology of Opius dissitus Muesebeck 1963 and Biosteres carbonarius Nees 1834, two diverse representatives of one of the least known and most diverse braconid subfamilies, the Opiinae. We review the terminology used to describe skeletal features in the Ichneumonoidea in general and the Opiinae in particular, and identify a list of recommend terms, which are linked to the online Hymenoptera Anatomy Ontology. The morphology of the studied species is illustrated with SEM-micrographs, photos and line drawings. Based on the examined species, we discuss intraspecific and interspecific morphological variation in the Opiinae and point out character complexes that merit further study. PMID:22558068

Skeletal morphology of Opius dissitus and Biosteres carbonarius (Hymenoptera: Braconidae), with a discussion of terminology.

PubMed

Karlsson, Dave; Ronquist, Fredrik

2012-01-01

The Braconidae, a family of parasitic wasps, constitute a major taxonomic challenge with an estimated diversity of 40,000 to 120,000 species worldwide, only 18,000 of which have been described to date. The skeletal morphology of braconids is still not adequately understood and the terminology is partly idiosyncratic, despite the fact that anatomical features form the basis for most taxonomic work on the group. To help address this problem, we describe the external skeletal morphology of Opius dissitus Muesebeck 1963 and Biosteres carbonarius Nees 1834, two diverse representatives of one of the least known and most diverse braconid subfamilies, the Opiinae. We review the terminology used to describe skeletal features in the Ichneumonoidea in general and the Opiinae in particular, and identify a list of recommend terms, which are linked to the online Hymenoptera Anatomy Ontology. The morphology of the studied species is illustrated with SEM-micrographs, photos and line drawings. Based on the examined species, we discuss intraspecific and interspecific morphological variation in the Opiinae and point out character complexes that merit further study.

DIRBE External Calibrator (DEC)

NASA Technical Reports Server (NTRS)

Wyatt, Clair L.; Thurgood, V. Alan; Allred, Glenn D.

1987-01-01

Under NASA Contract No. NAS5-28185, the Center for Space Engineering at Utah State University has produced a calibration instrument for the Diffuse Infrared Background Experiment (DIRBE). DIRBE is one of the instruments aboard the Cosmic Background Experiment Observatory (COBE). The calibration instrument is referred to as the DEC (Dirbe External Calibrator). DEC produces a steerable, infrared beam of controlled spectral content and intensity and with selectable point source or diffuse source characteristics, that can be directed into the DIRBE to map fields and determine response characteristics. This report discusses the design of the DEC instrument, its operation and characteristics, and provides an analysis of the systems capabilities and performance.

Morphology captures diet and locomotor types in rodents.

PubMed

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.

High variability in results of semen analysis in andrology laboratories in Tuscany (Italy): the experience of an external quality control (EQC) programme.

PubMed

Filimberti, E; Degl'Innocenti, S; Borsotti, M; Quercioli, M; Piomboni, P; Natali, I; Fino, M G; Caglieresi, C; Criscuoli, L; Gandini, L; Biggeri, A; Maggi, M; Baldi, E

2013-05-01

We report the results of the first three trials of an external quality control (EQC) programme performed in 71 laboratories executing semen analysis in Tuscany Region (Italy). At the end of the second trial, participants were invited to attend a teaching course illustrating and inviting to adhere to procedures recommended by WHO (V edition). Results of the first three trials of the EQC documented a huge variability in the procedures and the results. The highest variability was found for morphology (CV above 80% for all the trials), followed by count (CV of about 60% for all the trials) and motility (CV below 30% for all the trials). When results of sperm count and morphology were divided according to the used method, mean CV values did not show significant differences. CV for morphology dropped significantly at the third trial for most methods, indicating the usefulness of the teaching course for morphology assessment. Conversely, no differences were observed after the course for motility and for most methods to evaluate count, although CV values were lower at the second and third trial for the laboratories using the Burker cytometer. When results were divided according to tertiles of activity, the lowest mean bias values (difference between each laboratory result and the median value of the results) for count and morphology were observed for laboratories in the third tertile (performing over 200 semen analysis/year). Of interest, mean bias values for concentration dropped significantly at the third trial for low activity laboratories. In conclusion, lack of agreement of results of semen analysis in Tuscany is mainly because of the activity and the experience of the laboratory. Our study points out the importance of participating in EQC programmes and periodical teaching courses as well as the use of WHO recommended standardized procedures to increase precision and to allow the use of WHO reference values. © 2013 American Society of Andrology and European Academy of Andrology.

Morphological and molecular characteristics of Sarcocystis bertrami from horses and donkeys in China

USDA-ARS?s Scientific Manuscript database

Sarcocystis cysts collected from donkeys and horses were studied by morphological and molecular methods. Morphological studies performed by light microscopy (LM) revealed that each of two types of cysts were present in samples from both donkey and horse. These two types of cysts, type I (larger) and...

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

PubMed

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

2014-07-01

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

Comparative analysis of Rapana venosa (Valenciennes, 1846) from different biotopes of the Black Sea based on its morphological characteristics

NASA Astrophysics Data System (ADS)

Kos'yan, A. R.

2013-02-01

The Asian whelk Rapana venosa (Valenciennes, 1846) (Gastropoda: Neogastropoda: Muricidae), being tolerant to wide variations in the temperature, salinity, and oxygen concentration, successfully settled down in the Black Sea and eventually became one of the dominant species in the benthic ecosystems. The whelk inhabits all types of grounds all over the Black sea demonstrating a wide spectrum of morphological modifications. The objective of this research is to compare 10 samples of R. venosa from different biotopes of the Black Sea coast from the western Crimea to Sochi. The results of the statistical comparison based on 15 morphological characteristics showed that most of the samples differed from each other with high statistical significance ( p < 0.001). The material fell into five groups on the discriminant analysis diagram corresponding to the biotope in which each was collected. The main ecological factor influencing the morphological variability of the rapa whelk populations is the characteristics of prey items they feed on, i.e., the bivalve species ( Mytilus galloprovincialis, Anadara sp., Chamelea gallina), the prevailing prey size, and its abundance.

[Morphology of III stage larvae of Angiostrongylus cantonensis in Pomacea canaliculata].

PubMed

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.

Solid particle impingement erosion characteristics of cylindrical surfaces, pre-existing holes and slits

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.

Evaluating the predictive accuracy and the clinical benefit of a nomogram aimed to predict survival in node-positive prostate cancer patients: External validation on a multi-institutional database.

PubMed

Bianchi, Lorenzo; Schiavina, Riccardo; Borghesi, Marco; Bianchi, Federico Mineo; Briganti, Alberto; Carini, Marco; Terrone, Carlo; Mottrie, Alex; Gacci, Mauro; Gontero, Paolo; Imbimbo, Ciro; Marchioro, Giansilvio; Milanese, Giulio; Mirone, Vincenzo; Montorsi, Francesco; Morgia, Giuseppe; Novara, Giacomo; Porreca, Angelo; Volpe, Alessandro; Brunocilla, Eugenio

2018-04-06

To assess the predictive accuracy and the clinical value of a recent nomogram predicting cancer-specific mortality-free survival after surgery in pN1 prostate cancer patients through an external validation. We evaluated 518 prostate cancer patients treated with radical prostatectomy and pelvic lymph node dissection with evidence of nodal metastases at final pathology, at 10 tertiary centers. External validation was carried out using regression coefficients of the previously published nomogram. The performance characteristics of the model were assessed by quantifying predictive accuracy, according to the area under the curve in the receiver operating characteristic curve and model calibration. Furthermore, we systematically analyzed the specificity, sensitivity, positive predictive value and negative predictive value for each nomogram-derived probability cut-off. Finally, we implemented decision curve analysis, in order to quantify the nomogram's clinical value in routine practice. External validation showed inferior predictive accuracy as referred to in the internal validation (65.8% vs 83.3%, respectively). The discrimination (area under the curve) of the multivariable model was 66.7% (95% CI 60.1-73.0%) by testing with receiver operating characteristic curve analysis. The calibration plot showed an overestimation throughout the range of predicted cancer-specific mortality-free survival rates probabilities. However, in decision curve analysis, the nomogram's use showed a net benefit when compared with the scenarios of treating all patients or none. In an external setting, the nomogram showed inferior predictive accuracy and suboptimal calibration characteristics as compared to that reported in the original population. However, decision curve analysis showed a clinical net benefit, suggesting a clinical implication to correctly manage pN1 prostate cancer patients after surgery. © 2018 The Japanese Urological Association.

Production of ZrC Matrix for Use in Gas Fast Reactor Composite Fuels

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

Vasudevamurthy, Gokul; Knight, Travis W.; Roberts, Elwyn

2007-07-01

Zirconium carbide is being considered as a candidate for inert matrix material in composite nuclear fuel for Gas fast reactors due to its favorable characteristics. ZrC can be produced by the direct reaction of pure zirconium and graphite powders. Such a reaction is exothermic in nature. The reaction is self sustaining once initial ignition has been achieved. The heat released during the reaction is high enough to complete the reaction and achieve partial sintering without any external pressure applied. External heat source is required to achieve ignition of the reactants and maintain the temperature close to the adiabatic temperature tomore » achieve higher levels of sintering. External pressure is also a driving force for sintering. In the experiments described, cylindrical compacts of ZrC were produced by direct combustion reaction. External induction heating combined with varying amounts of external applied pressure was employed to achieve varying degrees of density/porosity. The effect of reactant particle size on the product characteristics was also studied. The samples were characterized for density/porosity, composition and microstructure. (authors)« less

Distinguishing between natural and hatchery Snake River fall Chinook salmon subyearlings in the field using body morphology

USGS Publications Warehouse

Tiffan, K.F.; Connor, W.P.

2011-01-01

We used body morphology to distinguish between natural- and hatchery-origin subyearling fall Chinook salmon Oncorhynchus tshawytscha in rearing areas of the Snake River and at a downstream dam during seaward migration. Using subjective eye and body shape characteristics, field personnel correctly classified 88.9–100% of natural subyearlings (N = 626) and 90.0–100% of hatchery subyearlings (N = 867) in rearing areas from 2001 to 2008. The morphological characteristics used by these personnel proved to have a quantitative basis, as was shown by digital photography and principal components analysis. Natural subyearlings had smaller eyes and pupils, smaller heads, deeper bodies, and shorter caudal peduncles than their hatchery counterparts during rearing and at the dam. A discriminant function fitted from this set of morphological characteristics classified the origin of fish during rearing and at the dam with over 97% accuracy. We hypothesize that these morphological differences were primarily due to environmental influences during incubation and rearing because it is highly probable that a large portion of the natural juveniles we studied were the offspring of hatchery × hatchery mating in the wild. The findings in this paper might provide guidance for others seeking to differentiate between natural and hatchery fish.

Dynamic Stress Testing Is Unnecessary for Unimalleolar Supination-External Rotation Ankle Fractures with Minimal Fracture Displacement on Lateral Radiographs.

PubMed

Nortunen, Simo; Leskelä, Hannu-Ville; Haapasalo, Heidi; Flinkkilä, Tapio; Ohtonen, Pasi; Pakarinen, Harri

2017-03-15

This study aimed to identify factors from standard radiographs that contributed to the stability of the ankle mortise in patients with isolated supination-external rotation fractures of the lateral malleolus (OTA/AO 44-B). Non-stress radiographs of the mortise and lateral views, without medial clear space widening or incongruity, were prospectively collected for 286 consecutive patients (mean age, 45 years [range, 16 to 85 years]), including 144 female patients (mean age, 50 years [range, 17 to 85 years]) and 142 male patients (mean age, 40 years [range, 16 to 84 years]) from 2 trauma centers. The radiographs were analyzed for fracture morphology by 2 orthopaedic surgeons, who were blinded to each other's measurements and to the results of external rotation stress radiographs (the reference for stability). Factors significantly associated with ankle mortise stability were tested in multiple logistic regression. Receiver operating characteristic analyses were performed for continuous variables to determine optimal thresholds. A sensitivity of >90% was used as the criterion for an optimal threshold. According to external rotation stress radiographs, 217 patients (75.9%) had a stable injury, defined as that with a medial clear space of <5 mm. Independent factors that predicted stable ankle mortise were female sex (odds ratio [OR], 2.5 [95% confidence interval (CI), 1.4 to 4.6]), a posterior diastasis of <2 mm (corresponding with a sensitivity of 0.94 and specificity of 0.39) on lateral radiographs (OR, 10.8 [95% CI, 3.7 to 31.5]), and only 2 fracture fragments (OR, 7.3 [95% CI, 2.1 to 26.3]). When the posterior diastasis was <2 mm and only 2 fracture fragments were present, the probability of a stable ankle mortise was 0.98 for 48 female patients (16.8%) and 0.94 for 37 male patients (12.9%). Patients with noncomminuted lateral malleolar fractures (85 patients [29.7%]) could be diagnosed with a stable ankle mortise without further stress testing, when the fracture line widths were <2 mm on lateral radiographs. Prognostic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Illustrated Key to Species of Genus Dendroctonus (Coleoptera: Curculionidae) Occurring in Mexico and Central America

PubMed Central

Armendáriz-Toledano, Francisco

2017-01-01

Abstract We provide an illustrated key of species of Dendroctonus Erichson from Mexico and Central America based on characters of the male genitalia and external morphology. The key incorporates newly identified diagnostic characters for this genus that enhance discrimination of particularly difficult sibling species. PMID:28355476

Interannual and long-term changes in the trophic state of a multibasin lake: Effects of morphology, climate, winter aeration, and beaver activity

USGS Publications Warehouse

Robertson, Dale M.; Rose, William; Reneau, Paul C.

2016-01-01

Little St. Germain Lake (LSG), a relatively pristine multibasin lake in Wisconsin, USA, was examined to determine how morphologic (internal), climatic (external), anthropogenic (winter aeration), and natural (beaver activity) factors affect the trophic state (phosphorus, P; chlorophyll, CHL; and Secchi depth, SD) of each of its basins. Basins intercepting the main flow and external P sources had highest P and CHL and shallowest SD. Internal loading in shallow, polymictic basins caused P and CHL to increase and SD to decrease as summer progressed. Winter aeration used to eliminate winterkill increased summer internal P loading and decreased water quality, while reductions in upstream beaver impoundments had little effect on water quality. Variations in air temperature and precipitation affected each basin differently. Warmer air temperatures increased productivity throughout the lake and decreased clarity in less eutrophic basins. Increased precipitation increased P in the basins intercepting the main flow but had little effect on the isolated deep West Bay. These relations are used to project effects of future climatic changes on LSG and other temperate lakes.

Genetic divergence between two phenotypically distinct bottlenose dolphin ecotypes suggests separate evolutionary trajectories.

PubMed

Fruet, Pedro F; Secchi, Eduardo R; Di Tullio, Juliana C; Simões-Lopes, Paulo César; Daura-Jorge, Fábio; Costa, Ana P B; Vermeulen, Els; Flores, Paulo A C; Genoves, Rodrigo Cezar; Laporta, Paula; Beheregaray, Luciano B; Möller, Luciana M

2017-11-01

Due to their worldwide distribution and occupancy of different types of environments, bottlenose dolphins display considerable morphological variation. Despite limited understanding about the taxonomic identity of such forms and connectivity among them at global scale, coastal (or inshore) and offshore (or oceanic) ecotypes have been widely recognized in several ocean regions. In the Southwest Atlantic Ocean (SWA), however, there are scarce records of bottlenose dolphins differing in external morphology according to habitat preferences that resemble the coastal-offshore pattern observed elsewhere. The main aim of this study was to analyze the genetic variability, and test for population structure between coastal ( n  = 127) and offshore ( n  = 45) bottlenose dolphins sampled in the SWA to assess whether their external morphological distinction is consistent with genetic differentiation. We used a combination of mtDNA control region sequences and microsatellite genotypes to infer population structure and levels of genetic diversity. Our results from both molecular marker types were congruent and revealed strong levels of structuring (microsatellites F ST  = 0.385, p  < .001; mtDNA F ST  =  0.183, p  < .001; Φ ST  = 0.385, p  < .001) and much lower genetic diversity in the coastal than the offshore ecotype, supporting patterns found in previous studies elsewhere. Despite the opportunity for gene flow in potential "contact zones", we found minimal current and historical connectivity between ecotypes, suggesting they are following discrete evolutionary trajectories. Based on our molecular findings, which seem to be consistent with morphological differentiations recently described for bottlenose dolphins in our study area, we recommend recognizing the offshore bottlenose dolphin ecotype as an additional Evolutionarily Significant Unit (ESU) in the SWA. Implications of these results for the conservation of bottlenose dolphins in SWA are also discussed.

Determination of the Three-Dimensional Morphology of ALH84001 and Biogenic MV-1 Magnetite: Comparison of Results from Electron Tomography and Classical Transmission Electron Microscopy

NASA Technical Reports Server (NTRS)

Thomas-Keprta, Kathie L.; Clemett, Simon J.; Schwartz, Cindy; Morphew, Mary; McIntosh, J. Richard; Bazylinski, Dennis A.; Kirschvink, Joseph L.; Wentworth, Susan J.; McKay, David S.; Vali, Hojatollah

2004-01-01

Dated at approximately 3.9 billion years of age, carbonate disks, found within fractures of the host rock of Martian meteorite ALH84001, have been interpreted as secondary minerals that formed at low temperature in an aqueous medium. Heterogeneously distributed within these disks are magnetite nanocrystals that are of Martian origin. Approximately one quarter of these magnetites have morphological and chemical similarities to magnetite particles produced by magnetotactic bacteria strain MV-1, which are ubiquitous in aquatic habitats on Earth. Moreover, these types of magnetite particles are not known or expected to be produced by abiotic means either through geological processes or synthetically in the laboratory. The remaining three quarters of the ALH84001 magnetites are likely products of multiple processes including, but not limited to, precipitation from a hydrothermal fluid, thermal decomposition of the carbonate matrix in which they are embedded, and extracellular formation by dissimilatory Fe-reducing bacteria. We have proposed that the origins of magnetites in ALH84001 can be best explained as the products of multiple processes, one of which is biological. Recently the three-dimensional (3-D) external morphology of the purported biogenic fraction of the ALH84001 magnetites has been the subject of considerable debate. We report here the 3-D geometry of biogenic magnetite crystals extracted from MV-1 and of those extracted from ALH84001 carbonate disks using a combination of high resolution classical and tomographic transmission electron microscopy (TEM). We focus on answering the following questions: (1) which technique provides adequate information to deduce the 3-D external crystal morphology?; and, (2) what is the precise 3-D geometry of the ALH84001 and MV-1 magnetites?

Early Callous-Unemotional Behavior, Theory-of-mind, and a Fearful/Inhibited Temperament Predict Externalizing Problems in Middle and Late Childhood

PubMed Central

Song, Ju-Hyun; Waller, Rebecca; Hyde, Luke W.; Olson, Sheryl L.

2016-01-01

Childhood externalizing problems are more likely to be severe and persistent when combined with high levels of callous-unemotional (CU) behavior. A handful of recent studies have shown that CU behavior can also be reliably measured in the early preschool years, which may help to identify young children who are less likely to desist from early externalizing behaviors. The current study extends previous literature by examining the role of CU behavior in very early childhood in the prediction of externalizing problems in both middle and late childhood, and tests whether other relevant child characteristics, including Theory-of-Mind (ToM) and fearful/inhibited temperament moderate these pathways. Multi-method data, including parent reports of child CU behavior and fearful/inhibited temperament, observations of ToM, and teacher-reported externalizing problems were drawn from a prospective, longitudinal study of children assessed at ages 3, 6, and 10 (N=241; 48% female). Results demonstrated that high levels of CU behavior predicted externalizing problems at ages 6 and 10 over and above the effect of earlier externalizing problems at age 3, but that these main effects were qualified by two interactions. High CU behavior was related to higher levels of externalizing problems specifically for children with low ToM and a low fearful/inhibited temperament. The results show that a multitude of child characteristics likely interact across development to increase or buffer risk for child externalizing problems. These findings can inform the development of targeted early prevention and intervention for children with high CU behavior. PMID:26582182

Early Callous-Unemotional Behavior, Theory-of-Mind, and a Fearful/Inhibited Temperament Predict Externalizing Problems in Middle and Late Childhood.

PubMed

Song, Ju-Hyun; Waller, Rebecca; Hyde, Luke W; Olson, Sheryl L

2016-08-01

Childhood externalizing problems are more likely to be severe and persistent when combined with high levels of callous-unemotional (CU) behavior. A handful of recent studies have shown that CU behavior can also be reliably measured in the early preschool years, which may help to identify young children who are less likely to desist from early externalizing behaviors. The current study extends previous literature by examining the role of CU behavior in very early childhood in the prediction of externalizing problems in both middle and late childhood, and tests whether other relevant child characteristics, including Theory-of-Mind (ToM) and fearful/inhibited temperament moderate these pathways. Multi-method data, including parent reports of child CU behavior and fearful/inhibited temperament, observations of ToM, and teacher-reported externalizing problems were drawn from a prospective, longitudinal study of children assessed at ages 3, 6, and 10 (N = 241; 48 % female). Results demonstrated that high levels of CU behavior predicted externalizing problems at ages 6 and 10 over and above the effect of earlier externalizing problems at age 3, but that these main effects were qualified by two interactions. High CU behavior was related to higher levels of externalizing problems specifically for children with low ToM and a low fearful/inhibited temperament. The results show that a multitude of child characteristics likely interact across development to increase or buffer risk for child externalizing problems. These findings can inform the development of targeted early prevention and intervention for children with high CU behavior.

Preparation and Characterization of Chitosan-coated Fe3O4 Nanoparticles using Ex-Situ Co-Precipitation Method and Tripolyphosphate/Sulphate as Dual Crosslinkers

NASA Astrophysics Data System (ADS)

Wulandari, Ika O.; Mardila, Vita T.; Santjojo, D. J. Djoko H.; Sabarudin, Akhmad

2018-01-01

The unique properties of nanomaterial provide great opportunities to develop in several fields. Several types of nanoparticles have been proven beneficial for biomedical and therapeutic agent development. Particularly for clinical use, nanoparticles must be biocompatible and non-toxic. Iron oxide nanoparticles consist of either magnetite (Fe3O4) or maghemite (γ-Fe2O3) was eligible to use for in vivo application including targeting drug delivery. Due to their distinct properties, these nanoparticles could be directed to the specific target under external magnetic field. However, nanoparticles have a tendency to form agglomeration. Therefore, surface modification was required to reduce the agglomeration. In this study, nanoparticles of Fe3O4 were produced and coated by biomaterial (chitosan) using ex-situ co-precipitation method. Nanoparticles of Fe3O4 were synthesized by adding ammonia water into iron ferric and ferrous solution. Synthesis process of Fe3O4 was conducted prior to adding chitosan. Chitosan was then cross-linked by a combination of tripolyphosphate/sulphate. The different composition ratio and crosslinking time provide the different physical and magnetic characteristics of nanoparticles. Particle and crystallite size was determined by using Scanning Electron Microscopy (SEM) and X-Ray Diffraction (XRD) respectively, whereas magnetic characteristic was determined by Electron Spin Resonance (ESR). The results showed that the ratio enhancement between chitosan: Fe3O4 increase the particle size, while decreased the crystallite size. Morphology and particle size were influenced by the ratio of crosslinkers. It was found that the higher tripolyphosphate content was contributed to the small size and more spherical morphology. In addition, the influence of crosslinking time toward crystallite size was determined by altering stirring time. The longer duration of crosslinking time, provide the larger crystallite size of chitosan-Fe3O4. There was an interesting correlation between particle size and amount of Fe3O4 phase with ESR curve.

Dynamic Changes of QRS Morphology of Premature Ventricular Contractions During Ablation in the Right Ventricular Outflow Tract: A Case Report.

PubMed

Yue-Chun, Li; Jia-Feng, Lin; Jia-Xuan, Lin

2015-10-01

Electrocardiographic characteristics can be useful in differentiating between right ventricular outflow tract (RVOT) and aortic sinus cusp (ASC) ventricular arrhythmias. Ventricular arrhythmias originating from ASC, however, show preferential conduction to RVOT that may render the algorithms of electrocardiographic characteristics less reliable. Even though there are few reports describing ventricular arrhythmias with ASC origins and endocardial breakout sites of RVOT, progressive dynamic changes in QRS morphology of the ventricular arrhythmias during ablation obtained were rare.This case report describes a patient with symptomatic premature ventricular contractions of left ASC origin presenting an electrocardiogram (ECG) characteristic of right ventricular outflow tract before ablation. Pacing at right ventricular outflow tract reproduced an excellent pace map. When radiofrequency catheter ablation was applied to the right ventricular outflow tract, the QRS morphology of premature ventricular contractions progressively changed from ECG characteristics of right ventricular outflow tract origin to ECG characteristics of left ASC origin.Successful radiofrequency catheter ablation was achieved at the site of the earliest ventricular activation in the left ASC. The distance between the successful ablation site of the left ASC and the site with an excellent pace map of the RVOT was 20 mm.The ndings could be strong evidence for a preferential conduction via the myocardial bers from the ASC origin to the breakout site in the right ventricular outflow tract. This case demonstrates that ventricular arrhythmias with a single origin and exit shift may exhibit QRS morphology changes.

Phylogenetic reconstruction of Syntermitinae (Isoptera, Termitidae) based on morphological and molecular data

PubMed Central

Cuezzo, Carolina; Cancello, Eliana M.

2017-01-01

The subfamily Syntermitinae comprises a group of Neotropical termites with 18 genera and 101 species described. It has been considered a natural group, but relationships among the genera within the subfamily remain uncertain, and some genera appear to be non-monophyletic. Here, we provide a comprehensive phylogeny including six Neotropical species of Termitinae as outgroup, 42 Syntermitinae species as ingroup, 92 morphological characters (from external and internal anatomy of soldier and worker castes) and 117 molecular sequences (109 obtained for this study and 8 from GenBank) of 4 gene regions (41 and 22 from Cytochrome Oxidase I and II respectively, 19 from Cytochrome b, and 35 from 16S rDNA). Morphological and molecular data were analyzed in combination, with the Bayesian inference method, and the important aspects of termite biology, defense and feeding habits are discussed based on the resulting tree. Although useful for providing diagnostic characters, the morphology of the soldier caste reveals several cases of convergence; whereas the feeding habit shows indications of evolutionary significance. PMID:28329010

Morphology of the jaw, suspensorial, and opercle musculature of Beloniformes and related species (Teleostei: Acanthopterygii), with a special reference to the m. adductor mandibulae complex.

PubMed

Werneburg, Ingmar

2015-01-01

The taxon Beloniformes represents a heterogeneous group of teleost fishes that show an extraordinary diversity of jaw morphology. I present new anatomical descriptions of the jaw musculature in six selected beloniforms and four closely related species. A reduction of the external jaw adductor (A1) and a changed morphology of the intramandibular musculature were found in many Beloniformes. This might be correlated with the progressively reduced mobility of the upper and lower jaw bones. The needlefishes and sauries, which are characterised by extremely elongated and stiffened jaws, show several derived characters, which in combination enable the capture of fish at high velocity. The ricefishes are characterised by several derived and many plesiomorphic characters that make broad scale comparisons difficult. Soft tissue characters are highly diverse among hemiramphids and flying fishes reflecting the uncertainty about their phylogenetic position and interrelationship. The morphological findings presented herein may help to interpret future phylogenetic analyses using cranial musculature in Beloniformes.

Comparative sacral morphology and the reconstructed tail lengths of five extinct primates: Proconsul heseloni, Epipliopithecus vindobonensis, Archaeolemur edwardsi, Megaladapis grandidieri, and Palaeopropithecus kelyus.

PubMed

Russo, Gabrielle A

2016-01-01

This study evaluated the relationship between the morphology of the sacrum-the sole bony link between the tail or coccyx and the rest of the body-and tail length (including presence/absence) and function using a comparative sample of extant mammals spanning six orders (Primates, Carnivora, Rodentia, Diprotodontia, Pilosa, Scandentia; N = 472). Phylogenetically-informed regression methods were used to assess how tail length varied with respect to 11 external and internal (i.e., trabecular) bony sacral variables with known or suspected biomechanical significance across all mammals, only primates, and only non-primates. Sacral variables were also evaluated for primates assigned to tail categories ('tailless,' 'nonprehensile short-tailed,' 'nonprehensile long-tailed,' and 'prehensile-tailed'). Compared to primates with reduced tail lengths, primates with longer tails generally exhibited sacra having larger caudal neural openings than cranial neural openings, and last sacral vertebrae with more mediolaterally-expanded caudal articular surfaces than cranial articular surfaces, more laterally-expanded transverse processes, more dorsally-projecting spinous processes, and larger caudal articular surface areas. Observations were corroborated by the comparative sample, which showed that shorter-tailed (e.g., Lynx rufus [bobcat]) and longer-tailed (e.g., Acinonyx jubatus [cheetah]) non-primate mammals morphologically converge with shorter-tailed (e.g., Macaca nemestrina) and longer-tailed (e.g., Macaca fascicularis) primates, respectively. 'Prehensile-tailed' primates exhibited last sacral vertebrae with more laterally-expanded transverse processes and greater caudal articular surface areas than 'nonprehensile long-tailed' primates. Internal sacral variables performed poorly compared to external sacral variables in analyses of extant primates, and were thus deemed less useful for making inferences concerning tail length and function in extinct primates. The tails lengths of five extinct primates were reconstructed from the external sacral variables: Archaeolemur edwardsi had a 'nonprehensile long tail,' Megaladapis grandidieri, Palaeopropithecus kelyus, and Epipliopithecus vindobonensis probably had 'nonprehensile short tails,' and Proconsul heseloni was 'tailless.' Copyright © 2015 Elsevier Ltd. All rights reserved.

Morphology of the mouthparts of the spittlebug Philagra albinotata Uhler (Hemiptera: Cercopoidea: Aphrophoridae).

PubMed

Wang, Tingting; Pan, Liuxing; Zhang, Yalin; Dai, Wu

2015-03-01

Mouthparts associated with feeding behavior and feeding habits are important sensory and feeding structures in insects. To obtain a better understanding of feeding in Cercopoidea, the morphology of mouthparts of the spittlebug, Philagra albinotata Uhler was examined using scanning electron microscopy. The mouthparts of P. albinotata are of the typical piercing-sucking type found in Hemiptera, comprising a cone-shaped labrum, a tube-like, three-segmented labium with a deep groove on the anterior side, and a stylet fascicle consisting of two mandibular and two maxillary stylets. The mandibles consist of a dorsal smooth region and a ventral serrate region near the apical half of the external convex region, and bear five nodules or teeth on the dorsal external convex region on the distal extremity; these are regarded as unique features that distinguish spittlebugs from other groups of Hemiptera. The externally smooth maxillary stylets, interlocked to form a larger food canal and a smaller salivary canal, are asymmetrical only in the internal position of longitudinal carinae and grooves. One dendritic canal is found in each maxilla and one in each mandible. Two types of sensilla trichodea, three types of sensilla basiconica and groups of multi-peg structures occur in different locations on the labium, specifically the labial tip with two lateral lobes divided into anterior sensory fields with ten small peg sensilla arranged in a 5+4+1 pattern and one big peg sensillum, and posterior sensory fields with four sensilla trichodea. Compared with those of previously studied Auchenorrhyncha, the mouthparts of P. albinotata may be distinguished by the shape of the mandibles, the multi-peg structures and a tooth between the salivary canal and the food canal on the extreme end of the stylets. The mouthpart morphology is illustrated using scanning electron micrographs, and the taxonomic and putative functional significance of the different structures is briefly discussed. Copyright © 2014 Elsevier Ltd. All rights reserved.

Morphology and physical-chemical properties of celluloses obtained by different methods

NASA Astrophysics Data System (ADS)

Anpilova, A. Yu.; Mastalygina, E. E.; Mikhaylov, I. A.; Popov, A. A.; Kartasheva, Z. S.

2017-12-01

The morphology and structural characteristics of celluloses obtained by different methods were studied. The objects of the investigation are cellulose from pulp source, commercial celluloses produced by sodium and acid hydrolysis, laboratory produced cellulose from bleached birch kraft pulp, and cellulose obtained by thermooxidative catalytic treatment of maple leaves by peroxide. According to a complex analysis of cellulose characteristics, several types of celluloses were offered as modifying additives for polymers.

McGET: A rapid image-based method to determine the morphological characteristics of gravels on the Gobi desert surface

NASA Astrophysics Data System (ADS)

Mu, Yue; Wang, Feng; Zheng, Bangyou; Guo, Wei; Feng, Yiming

2018-03-01

The relationship between morphological characteristics (e.g. gravel size, coverage, angularity and orientation) and local geomorphic features (e.g. slope gradient and aspect) of desert has been used to explore the evolution process of Gobi desert. Conventional quantification methods are time-consuming, inefficient and even prove impossible to determine the characteristics of large numbers of gravels. We propose a rapid image-based method to obtain the morphological characteristics of gravels on the Gobi desert surface, which is called the "morphological characteristics gained effectively technique" (McGET). The image of the Gobi desert surface was classified into gravel clusters and background by a machine-learning "classification and regression tree" (CART) algorithm. Then gravel clusters were segmented into individual gravel clasts by separating objects in images using a "watershed segmentation" algorithm. Thirdly, gravel coverage, diameter, aspect ratio and orientation were calculated based on the basic principles of 2D computer graphics. We validated this method with two independent datasets in which the gravel morphological characteristics were obtained from 2728 gravels measured in the field and 7422 gravels measured by manual digitization. Finally, we applied McGET to derive the spatial variation of gravel morphology on the Gobi desert along an alluvial-proluvial fan located in Hami, Xinjiang, China. The validated results show that the mean gravel diameter measured in the field agreed well with that calculated by McGET for large gravels (R2 = 0.89, P < 0.001). Compared to manual digitization, the McGET accuracies for gravel coverage, gravel diameter and aspect ratio were 97%, 83% and 96%, respectively. The orientation distributions calculated were consistent across two different methods. More importantly, McGET significantly shortens the time cost in obtaining gravel morphological characteristics in the field and laboratory. The spatial variation results show that the gravel coverage ranged from 88% to 65%, the gravel diameter was unimodally distributed and ranged from 19 mm to 13 mm. Most gravels were bladed or rod-like, with a mean aspect ratio of 1.57, and had no preferred orientation on the surveyed Gobi desert. From the center to the edge of the fan, gravel coverage decreased 2.2% per 100 m elevation decrease (R2 = 0.69, P < 0.001), mean gravel diameter decreased 0.5 mm per 100 m elevation decrease (R2 = 0.52, P < 0.001), and mean aspect ratio slightly increased 0.004 per 100 m elevation decrease (R2 = 0.26, P < 0.05). These results imply that surface washing was the main process on the investigated Gobi desert. This study demonstrates that the new method can quickly and accurately calculate the gravel coverage, diameter, aspect ratio and orientation from the images of Gobi desert.

Free-flight investigation of the stability and control characteristics of a STOL model with an externally blown jet flap

NASA Technical Reports Server (NTRS)

Parlett, L. P.; Emerling, S. J.; Phelps, A. E., III

1974-01-01

The stability and control characteristics of a four-engine turbofan STOL transport model having an externally blown jet flap have been investigated by means of the flying-model technique in the Langley full-scale tunnel. The flight characteristics of the model were investigated under conditions of symmetric and asymmetric (one engine inoperative) thrust at lift coefficients up to 9.5 and 5.5, respectively. Static characteristics were studied by conventional power-on force tests over the flight-test angle-of-attack range including the stall. In addition to these tests, dynamic longitudinal and lateral stability calculations were performed for comparison with the flight-test results and for use in correlating the model results with STOL handling-qualities criteria.

Evolution of external genitalia: insights from reptilian development.

PubMed

Gredler, Marissa L; Larkins, Christine E; Leal, Francisca; Lewis, A Kelsey; Herrera, Ana M; Perriton, Claire L; Sanger, Thomas J; Cohn, Martin J

2014-01-01

External genitalia are found in each of the major clades of amniotes. The phallus is an intromittent organ that functions to deliver sperm into the female reproductive tract for internal fertilization. The cellular and molecular genetic mechanisms of external genital development have begun to be elucidated from studies of the mouse genital tubercle, an embryonic appendage adjacent to the cloaca that is the precursor of the penis and clitoris. Progress in this area has improved our understanding of genitourinary malformations, which are among the most common birth defects in humans, and created new opportunities for comparative studies of other taxa. External genitalia evolve rapidly, which has led to a striking diversity of anatomical forms. Within the past year, studies of external genital development in non-mammalian amniotes, including birds, lizards, snakes, alligators, and turtles, have begun to shed light on the molecular and morphogenetic mechanisms underlying the diversification of phallus morphology. Here, we review recent progress in the comparative developmental biology of external genitalia and discuss the implications of this work for understanding external genital evolution. We address the question of the deep homology (shared common ancestry) of genital structures and of developmental mechanisms, and identify new areas of investigation that can be pursued by taking a comparative approach to studying development of the external genitalia. We propose an evolutionary interpretation of hypospadias, a congenital malformation of the urethra, and discuss how investigations of non-mammalian species can provide novel perspectives on human pathologies.

Morphological and functional characteristics of human gingival junctional epithelium.

PubMed

Jiang, Qian; Yu, Youcheng; Ruan, Hong; Luo, Yin; Guo, Xuehua

2014-04-03

This study aims to observe the morphological characteristics and identify the function characteristics of junctional epithelium (JE) tissues and cultured JE cells. Paraffin sections of human molar or premolar on the gingival buccolingual side were prepared from 6 subjects. HE staining and image analysis were performed to measure and compare the morphological difference among JE, oral gingival epithelium (OGE) and sulcular epithelium (SE). Immunohistochemistry was applied to detect the expression pattern of cytokeratin 5/6, 7, 8/18, 10/13, 16, 17, 19, and 20 in JE, OGE and SE. On the other hand, primary human JE and OGE cells were cultured in vitro. Cell identify was confirmed by histology and immunohistochemistry. In a co-culture model, TEM was used to observe the attachment formation between JE cells and tooth surface. Human JE was a unique tissue which was different from SE and OGE in morphology. Similarly, morphology of JE cells was also particular compared with OGE cells cultured in vitro. In addition, JE cells had a longer incubation period than OGE cells. Different expression of several CKs illustrated JE was in a characteristic of low differentiation and high regeneration. After being co-cultured for 14 d, multiple cell layers, basement membrane-like and hemidesmosome-like structures were appeared at the junction of JE cell membrane and tooth surface. JE is a specially stratified epithelium with low differentiation and high regeneration ability in gingival tissue both in vivo and in vitro. In co-culture model, human JE cells can form basement membrane-like and hemidesmosome-like structures in about 2 weeks.

Draw forming of scale shuttle external tank dome gores

NASA Technical Reports Server (NTRS)

Garfield, G.

1974-01-01

The process for manufacturing external tank dome gores is discussed. The test fixture and test procedure are described. The characteristics of the draw forming die are analyzed. The specific subjects included are: (1) forming, (2) trimming, (3) cleaning, and (4) heat treatment.

Morphology of pulp fiber from hardwoods and influence on paper strength

Treesearch

Richard A. Horn

1978-01-01

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

Morphological Structure Processing during Word Recognition and Its Relationship to Character Reading among Third-Grade Chinese Children

ERIC Educational Resources Information Center

Liu, Duo; McBride-Chang, Catherine

2014-01-01

In the present study, we explored the characteristics of morphological structure processing during word recognition among third grade Chinese children and its possible relationship with Chinese character reading. By using the modified priming lexical decision paradigm, a significant morphological structure priming effect was found in the subject…

14 CFR 133.41 - Flight characteristics requirements.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 14 Aeronautics and Space 3 2013-01-01 2013-01-01 false Flight characteristics requirements. 133.41... EXTERNAL-LOAD OPERATIONS Airworthiness Requirements § 133.41 Flight characteristics requirements. (a) The applicant must demonstrate to the Administrator, by performing the operational flight checks prescribed in...

14 CFR 133.41 - Flight characteristics requirements.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 14 Aeronautics and Space 3 2012-01-01 2012-01-01 false Flight characteristics requirements. 133.41... EXTERNAL-LOAD OPERATIONS Airworthiness Requirements § 133.41 Flight characteristics requirements. (a) The applicant must demonstrate to the Administrator, by performing the operational flight checks prescribed in...

14 CFR 133.41 - Flight characteristics requirements.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Flight characteristics requirements. 133.41... EXTERNAL-LOAD OPERATIONS Airworthiness Requirements § 133.41 Flight characteristics requirements. (a) The applicant must demonstrate to the Administrator, by performing the operational flight checks prescribed in...

Economic Culture and Trading Behaviors in Information Markets

ERIC Educational Resources Information Center

Alhayyan, Khalid N.

2012-01-01

There are four main components for influencing traders' behaviors in an information market context: trader characteristics, organizational characteristics, market design, and external information. This dissertation focuses on investigating the impact of individual trader characteristics on trading behaviors. Two newly-developed constructs,…

Metric and morphological assessment of facial features: a study on three European populations.

PubMed

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.

Effects of morphological control on the characteristics of vertical-type OTFTs using Alq3.

PubMed

Kim, Young Do; Park, Jong Wook; Kang, In Nam; Oh, Se Young

2008-09-01

We have fabricated vertical-type organic thin-film transistors (OTFTs) using tris-(8-hydroxyquinoline) aluminum (Alq(3)) as an n-type active material. Vertical-type OTFT using Alq(3) has a layered structure of Al(source electrode)/Alq(3)(active layer)/Al(gate electrode)/Alq(3)(active layer)/ITO glass(drain electrode). Alq(3) thin films containing various surface morphologies could be obtained by the control of evaporation rate and substrate temperature. The effects of the morphological control of Alq(3) thin layer on the grain size and the flatness of film surface were investigated. The characteristics of vertical-type OTFT significantly influenced the growth condition of Alq(3) layer.

Thrust and drag characteristics of a convergent-divergent nozzle with various exhaust jet temperatures

NASA Technical Reports Server (NTRS)

Hearth, Donald P; Wilcox, Fred A

1954-01-01

An investigation was conducted in the 8-by-6 foot supersonic wind tunnel on the effect of exhaust-gas temperatures on the external and internal characteristics of a convergent-divergent nozzle having an area expansion ratio of 1.83. Data were obtained over a pressure-ratio range from 1 to 20 at free-stream Mach numbers of 1.6 and 2.0 for exhaust temperatures of 860 degrees, 1650 degrees, and 2000 degrees R. Results of this investigation indicated that generally both the internal and external performance characteristics were only slightly affected by a large change in jet temperature. The small differences in performance which did occur were predicted satisfactorily from theoretical considerations.

A morphological comparison of narrow, low-gradient streams traversing wetland environments to alluvial streams.

PubMed

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.

On the characteristics of a residual external signal seen in coefficients of main geomagnetic field models

NASA Astrophysics Data System (ADS)

Stefan, Cristiana; Demetrescu, Crisan; Dobrica, Venera

2014-05-01

Several recently developed main geomagnetic field models, based on both observatory and satellite data (e.g. IGRF, CHAOS, GRIMM, COV-OBS), as well as the historical model gufm1, have been designed to describe only the internal part of the field, except for the COV-OBS that also accounts for the external dipole. In this paper we analyze data and coefficients from two main field models, namely gufm1 (Jackson et al., 2000) and COV-OBS (Gillet et al., 2013), by means of low pass filters with a cutoff period of 11-year, to evidence a residual signal with seemingly external sources, superimposed on the internal part of the field. The characteristics of the residual signal in the dipole and non-dipole coefficients are discussed.

Astragalar Morphology of Selected Giraffidae.

PubMed

Solounias, Nikos; Danowitz, Melinda

2016-01-01

The artiodactyl astragalus has been modified to exhibit two trochleae, creating a double pullied structure allowing for significant dorso-plantar motion, and limited mediolateral motion. The astragalus structure is partly influenced by environmental substrates, and correspondingly, morphometric studies can yield paleohabitat information. The present study establishes terminology and describes detailed morphological features on giraffid astragali. Each giraffid astragalus exhibits a unique combination of anatomical characteristics. The giraffid astragalar morphologies reinforce previously established phylogenetic relationships. We find that the enlargement of the navicular head is a feature shared by all giraffids, and that the primitive giraffids possess exceptionally tall astragalar heads in relation to the total astragalar height. The sivatheres and the okapi share a reduced notch on the lateral edge of the astragalus. We find that Samotherium is more primitive in astragalar morphologies than Palaeotragus, which is reinforced by tooth characteristics and ossicone position. Diagnostic anatomical characters on the astragalus allow for giraffid species identifications and a better understanding of Giraffidae.

The external morphology of the mouthparts, and observations on feeding and behavior of Tuckerella japonica on Camellia sinensis in the continental United States

USDA-ARS?s Scientific Manuscript database

Tuckerella japonica Ehara (Acari: Tetranychoidea: Tuckerellidae) is found where longitudinal splitting occurs on exposed green periderm tissue of shoots on certain varieties or seedling plants of Camellia sinensis (L.) O. Kuntze (Theales: Theaceae) in the continental United States. The mite is able ...

Correlation of emission capability and longevity of dispenser cathodes with characteristics of tungsten powders

NASA Astrophysics Data System (ADS)

Melnikova, Irina P.; Vorozheikin, Victor G.; Usanov, Dmitry A.

2003-06-01

The intercorrelation of tungsten powder properties, such as grain size, distribution and morphology, and porous matrix parameters with electron emission capability and longevity of Ba dispenser cathodes are investigated for three different grain morphologies. Best results of tungsten cathode life were found for isoaxis polyhedron morphology in combination with certain powder and matrix parameters.

Freezing behavior of adherent neuron-like cells and morphological change and viability of post-thaw cells.

PubMed

Uemura, Makoto; Ishiguro, Hiroshi

2015-04-01

Freezing of nerve cells forming a neuronal network has largely been neglected, despite the fact that the cryopreservation of nerve cells benefits the study of cells in the areas of medicine and poison screening. Freezing of nerve cells is also attractive for studying cell morphology because of the characteristic long, thread-like neurites extending from the cell body. In the present study, freezing of neuron-like cells adhering to the substrate (differentiated PC12 cells), in physiological saline, was investigated in order to understand the fundamental freezing and thawing characteristics of nerve cells with neurites. The microscopic freezing behavior of cells under different cooling rates was observed. Next, the post-thaw morphological changes in the cells, including the cytoskeleton, were investigated and post-thaw cell viability was evaluated by dye exclusion using propidium iodide. Two categories of morphological changes, beading and shortening of the neurites, were found and quantified. Also, the morphological changes of neurites due to osmotic stress from sodium chloride were studied to gain a better understanding of causation. The results showed that morphological changes and cell death were promoted with a decrease in end temperature during freezing. Copyright © 2015 Elsevier Inc. All rights reserved.

The vocal sac of Hylodidae (Amphibia, Anura): Phylogenetic and functional implications of a unique morphology.

PubMed

Elias-Costa, Agustin J; Montesinos, Rachel; Grant, Taran; Faivovich, Julián

2017-11-01

Anuran vocal sacs are elastic chambers that recycle exhaled air during vocalizations and are present in males of most species of frogs. Most knowledge of the diversity of vocal sacs relates to external morphology; detailed information on internal anatomy is available for few groups of frogs. Frogs of the family Hylodidae, which is endemic to the Atlantic Forest of Brazil and adjacent Argentina and Paraguay, have three patterns of vocal sac morphology-that is, single, subgular; paired, lateral; and absent. The submandibular musculature and structure of the vocal sac mucosa (the internal wall of the vocal sac) of exemplar species of this family and relatives were studied. In contrast to previous accounts, we found that all species of Crossodactylus and Hylodes possess paired, lateral vocal sacs, with the internal mucosa of each sac being separate from the contralateral one. Unlike all other frogs for which data are available, the mucosa of the vocal sacs in these genera is not supported externally by the mm. intermandibularis and interhyoideus. Rather, the vocal sac mucosa projects through the musculature and is free in the submandibular lymphatic sac. The presence of paired, lateral vocal sacs, the internal separation of the sac mucosae, and their projection through the m. interhyoideus are synapomorphies of the family. Furthermore, the specific configuration of the m. interhyoideus allows asymmetric inflation of paired vocal sacs, a feature only reported in species of these diurnal, stream-dwelling frogs. © 2017 Wiley Periodicals, Inc.

External tufted cells in the main olfactory bulb form two distinct subpopulations.

PubMed

Antal, Miklós; Eyre, Mark; Finklea, Bryson; Nusser, Zoltan

2006-08-01

The glomeruli of the main olfactory bulb are the first processing station of the olfactory pathway, where complex interactions occur between sensory axons, mitral cells and a variety of juxtaglomerular neurons, including external tufted cells (ETCs). Despite a number of studies characterizing ETCs, little is known about how their morphological and functional properties correspond to each other. Here we determined the active and passive electrical properties of ETCs using in vitro whole-cell recordings, and correlated them with their dendritic arborization patterns. Principal component followed by cluster analysis revealed two distinct subpopulations of ETCs based on their electrophysiological properties. Eight out of 12 measured physiological parameters exhibited significant difference between the two subpopulations, including the membrane time constant, amplitude of spike afterhyperpolarization, variance in the interspike interval distribution and subthreshold resonance. Cluster analysis of the morphological properties of the cells also revealed two subpopulations, the most prominent dissimilarity between the groups being the presence or absence of secondary, basal dendrites. Finally, clustering the cells taking all measured properties into account also indicated the presence of two subpopulations that mapped in an almost perfect one-to-one fashion to both the physiologically and the morphologically derived groups. Our results demonstrate that a number of functional and structural properties of ETCs are highly predictive of one another. However, cells within each subpopulation exhibit pronounced variability, suggesting a large degree of specialization evolved to fulfil specific functional requirements in olfactory information processing.

External tufted cells in the main olfactory bulb form two distinct subpopulations

PubMed Central

Antal, Miklós; Eyre, Mark; Finklea, Bryson; Nusser, Zoltan

2006-01-01

The glomeruli of the main olfactory bulb are the first processing station of the olfactory pathway, where complex interactions occur between sensory axons, mitral cells and a variety of juxtaglomerular neurons, including external tufted cells (ETCs). Despite a number of studies characterizing ETCs, little is known about how their morphological and functional properties correspond to each other. Here we determined the active and passive electrical properties of ETCs using in vitro whole-cell recordings, and correlated them with their dendritic arborization patterns. Principal component followed by cluster analysis revealed two distinct subpopulations of ETCs based on their electrophysiological properties. Eight out of 12 measured physiological parameters exhibited significant difference between the two subpopulations, including the membrane time constant, amplitude of spike afterhyperpolarization, variance in the interspike interval distribution and subthreshold resonance. Cluster analysis of the morphological properties of the cells also revealed two subpopulations, the most prominent dissimilarity between the groups being the presence or absence of secondary, basal dendrites. Finally, clustering the cells taking all measured properties into account also indicated the presence of two subpopulations that mapped in an almost perfect one-to-one fashion to both the physiologically and the morphologically derived groups. Our results demonstrate that a number of functional and structural properties of ETCs are highly predictive of one another. However, cells within each subpopulation exhibit pronounced variability, suggesting a large degree of specialization evolved to fulfil specific functional requirements in olfactory information processing. PMID:16930438

SAPO-34/AlMCM-41, as a novel hierarchical nanocomposite: preparation, characterization and investigation of synthesis factors using response surface methodology

NASA Astrophysics Data System (ADS)

Roohollahi, Hossein; Halladj, Rouein; Askari, Sima; Yaripour, Fereydoon

2018-06-01

SAPO-34/AlMCM-41, as a new hierarchical nanocomposite was successfully synthesized via hydrothermal and dry-gel conversion. In an experimental and statistical study, effect of five input parameters including synthesis period, drying temperature, NaOH/Si, water/dried-gel and SAPO% were investigated on range-order degree of mesochannels and the relative crystallinity. X-ray diffraction (XRD) patterns were recorded to characterize the ordered AlMCM-41 and crystalline SAPO-34 structures. Nitrogen adsorption-desorption technique, scanning electron microscopy (SEM), field-emission SEM (FESEM) equipped with an energy-dispersive X-ray spectroscopy (EDS-Map) and transmission electron microscopy (TEM) were used to study the textural properties, morphology and surface elemental composition. Two reduced polynomials were fitted to the responses with good precision. Further, based on analysis of variances, SAPO% and time duration of dry-gel conversion were observed as the most effective parameters on the composite structure. The hierarchical porosity, narrow pore size distribution, high external surface area and large specific pore volume were of interesting characteristics for this novel nanocomposite.

Evidence of sexually dimorphic introgression in Pinaleno Mountain Apache trout

USGS Publications Warehouse

Porath, M.T.; Nielsen, J.L.

2003-01-01

The high-elevation headwater streams of the Pinaleno Mountains support small populations of threatened Apache trout Oncorhynchus apache that were stocked following the chemical removal of nonnative salmonids in the 1960s. A fisheries survey to assess population composition, growth, and size structure confirmed angler reports of infrequent occurrences of Oncorhynchus spp. exhibiting the external morphological characteristics of both Apache trout and rainbow trout O. mykiss. Nonlethal tissue samples were collected from 50 individuals in the headwaters of each stream. Mitochondrial DNA (mtDNA) sequencing and amplification of nuclear microsatellite loci were used to determine the levels of genetic introgression by rainbow trout in Apache trout populations at these locations. Sexually dimorphic introgression from the spawning of male rainbow trout with female Apache trout was detected using mtDNA and microsatellites. Estimates of the degree of hybridization based on three microsatellite loci were 10-88%. The use of nonlethal DNA genetic analyses can supplement information obtained from standard survey methods and be useful in assessing the relative importance of small and sensitive populations with a history of nonnative introductions.

Flightless litter-dwelling Cotasterosoma (Coleoptera: Curculionidae: Cossoninae) found outside of Japan, with mtDNA phylogeography of a new species from Southwest China.

PubMed

Grebennikov, Vasily V; Morimoto, Katsura

2016-10-28

The herein reported beetles (Figs 1, 2) were repeatedly sampled by the first author since 2008 by sifting leaf litter in two forested localities in Southwest China: Cang Shan Mountain Range in Yunnan and Mount Emei in Sichuan (Fig. 3). The specimens' characteristic appearance and edaphic way of life were consistent with those of various members of the subfamily Cossoninae (Morimoto 1973, 1993, 1995), although a more precise taxonomic assignment remained elusive. In 2015 the second author saw images of these beetles and suggested their affinities to the genus Cotasterosoma Konishi, 1962. This taxon until present was known from a single specimen collected in 1954 in Shikoku, Japan, and illustrated in Morimoto (1993), although additional congeneric specimens are known to the second author. The purpose of this paper is to document our discovery of the genus in Southwest China by describing a new species, illustrating its external and genital morphological characters, releasing DNA barcode data and providing phylogeographic interpretations of our findings.

Highly Luminescent 2D-Type Slab Crystals Based on a Molecular Charge-Transfer Complex as Promising Organic Light-Emitting Transistor Materials.

PubMed

Park, Sang Kyu; Kim, Jin Hong; Ohto, Tatsuhiko; Yamada, Ryo; Jones, Andrew O F; Whang, Dong Ryeol; Cho, Illhun; Oh, Sangyoon; Hong, Seung Hwa; Kwon, Ji Eon; Kim, Jong H; Olivier, Yoann; Fischer, Roland; Resel, Roland; Gierschner, Johannes; Tada, Hirokazu; Park, Soo Young

2017-09-01

A new 2:1 donor (D):acceptor (A) mixed-stacked charge-transfer (CT) cocrystal comprising isometrically structured dicyanodistyrylbenzene-based D and A molecules is designed and synthesized. Uniform 2D-type morphology is manifested by the exquisite interplay of intermolecular interactions. In addition to its appealing structural features, unique optoelectronic properties are unveiled. Exceptionally high photoluminescence quantum yield (Φ F ≈ 60%) is realized by non-negligible oscillator strength of the S 1 transition, and rigidified 2D-type structure. Moreover, this luminescent 2D-type CT crystal exhibits balanced ambipolar transport (µ h and µ e of ≈10 -4 cm 2 V -1 s -1 ). As a consequence of such unique optoelectronic characteristics, the first CT electroluminescence is demonstrated in a single active-layered organic light-emitting transistor (OLET) device. The external quantum efficiency of this OLET is as high as 1.5% to suggest a promising potential of luminescent mixed-stacked CT cocrystals in OLET applications. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Microbial production of metabolites and associated enzymatic reactions under high pressure.

PubMed

Dong, Yongsheng; Jiang, Hua

2016-11-01

High environmental pressure exerts an external stress on the survival of microorganisms that are commonly found under normal pressure. In response, many growth traits alter, including cell morphology and physiology, cellular structure, metabolism, physical and chemical properties, the reproductive process, and defense mechanisms. The high-pressure technology (HP) has been industrially utilized in pressurized sterilization, synthesis of stress-induced products, and microbial/enzymatic transformation of chemicals. This article reviews current research on pressure-induced production of metabolites in normal-pressure microbes and their enzymatic reactions. Factors that affect the production of such metabolites are summarized, as well as the effect of pressure on the performance of microbial fermentation and the yield of flavoring compounds, different categories of induced enzymatic reactions and their characteristics in the supercritical carbon dioxide fluid, effects on enzyme activity, and the selection of desirable bacterial strains. Technological challenges are discussed, and future research directions are proposed. Information presented here will benefit the research, development, and application of the HP technology to improve microbial fermentation and enzymatic production of biologically active substances, thereby help to meet their increasing demand from the ever-expanding market.

Identification and regulation of fusA, the polyketide synthase gene responsible for fusarin production in Fusarium fujikuroi.

PubMed

Díaz-Sánchez, Violeta; Avalos, Javier; Limón, M Carmen

2012-10-01

Fusarins are a class of mycotoxins of the polyketide family produced by different Fusarium species, including the gibberellin-producing fungus Fusarium fujikuroi. Based on sequence comparisons between polyketide synthase (PKS) enzymes for fusarin production in other Fusarium strains, we have identified the F. fujikuroi orthologue, called fusA. The participation of fusA in fusarin biosynthesis was demonstrated by targeted mutagenesis. Fusarin production is transiently stimulated by nitrogen availability in this fungus, a regulation paralleled by the fusA mRNA levels in the cell. Illumination of the cultures results in a reduction of the fusarin content, an effect partially explained by a high sensitivity of these compounds to light. Mutants of the fusA gene exhibit no external phenotypic alterations, including morphology and conidiation, except for a lack of the characteristic yellow and/or orange pigmentation of fusarins. Moreover, the fusA mutants are less efficient than the wild type at degrading cellophane on agar cultures, a trait associated with pathogenesis functions in Fusarium oxysporum. The fusA mutants, however, are not affected in their capacities to grow on plant tissues.

Structural and optical properties of p-quaterphenyl thin films and application in organic/inorganic photodiodes

NASA Astrophysics Data System (ADS)

Attia, A. A.; Saadeldin, M. M.; Soliman, H. S.; Gadallah, A.-S.; Sawaby, K.

2016-12-01

Para-quaterpheny1 (p-4pheny1) thin films were deposited by the thermal evaporation method on glass/quartz substrates for structural and optical investigations. The XRD of p-4phenyl thin films showed that the as-deposited films have a monoclinic structure. The surface morphology of p-4phenyl thin film was studied using scanning electron microscope. The absorption spectrum of p-4phenyl thin film recorded in the wavelength range 200-2500 nm. Photoluminescence measurements revealed two emission peaks at 435 and 444 nm using N2-laser (337.8 nm). The energy gap obtained from the absorption and photoluminescence data was found to be 2.87 and 2.74 eV respectively with Stokes shift value of 0.13 eV. The current-voltage characteristics of p-4phenyl/p-Si heterojunction have been recorded in the dark and under illumination of laser (337.8 nm). Responsivity, Detectivity, External quantum efficiency and Response speed of (Au/p-4pheny1/p-Si/Al) photodetector have been determined using different laser sources at -1 V bias.

Implications for late Grenvillian (Rigolet phase) construction of Rodinia using new U-Pb data from the Mars Hill terrane, Tennessee and North Carolina, United States

USGS Publications Warehouse

Aleinikoff, John N.; Southworth, Scott; Merschat, Arthur J.

2013-01-01

New data for zircon (external morphology, cathodoluminescence zoning, and sensitive high resolution ion microprobe [SHRIMP] U-Pb ages) from the Carvers Gap granulite gneiss of the Mars Hill terrane (Tennessee and North Carolina, United States) require reevaluation of interpretations of the age and origin of this rock. The new results indicate that the zircon is detrital and that the sedimentary protolith of this gneiss (and related Cloudland gneiss) was deposited no earlier than ca. 1.02 Ga and was metamorphosed at ca. 0.98 Ga. Tectonic models that included the gneiss as a piece of 1.8 Ga Amazonian crust (perhaps as part of the hypothetical Columbia supercontinent) are now untenable. The remarkably fast cycle of exhumation, erosion, deposition, and deep burial also is characteristic of other late Grenvillian (post-Ottawan) Mesoproterozoic paragneisses that occur throughout the Appalachians. These rocks provide new evidence for the duration of the formation of the Rodinia supercontinent lasting until at least 0.98 Ma.

Temporal switching of an amphiphilic self-assembly by a chemical fuel-driven conformational response† †Electronic supplementary information (ESI) available: Experimental section, synthetic procedures and supporting figures. See DOI: 10.1039/c7sc01730h Click here for additional data file.

PubMed Central

Jalani, Krishnendu; Dhiman, Shikha

2017-01-01

The spatial and temporal control of self-assemblies is the latest scientific hurdle in supramolecular chemistry which is inspired by the functioning of biological systems fueled by chemical signals. In this study, we work towards alleviating this scenario by employing a unique amphiphilic foldamer that operates under the effect of a chemical fuel. The conformational changes in the foldamer amplify into observable morphological changes in its amphiphilic assembly that are controlled by external molecular cues (fuel). We take advantage of this redox responsive foldamer to affect its conformation in a temporal manner by an enzymatic pathway. The temporal characteristics of the transient conformation/assembly can be modulated by varying the concentrations of the fuel and enzyme. We believe that such a design strategy can have positive consequences in designing molecular and supramolecular systems for future active, adaptive and autonomous materials. PMID:28989632

Response of a Bell–Bloom Magnetometer to a Magnetic Field of Arbitrary Direction

PubMed Central

Ding, Zhichao; Yuan, Jie; Long, Xingwu

2018-01-01

The Bell–Bloom magnetometer in response to a magnetic field of arbitrary direction is observed theoretically and experimentally. A theoretical model is built from a macroscopic view to simulate the magnetometer frequency response to an external magnetic field of arbitrary direction. Based on the simulation results, the magnetometer characteristics, including the signal phase and amplitude at resonance, the linewidth, and the magnetometer sensitivity, are analyzed, and the dependencies of these characteristics on the external magnetic field direction are obtained, which are verified by the experiment. PMID:29724059

Crystallography of biological fluid as a method for evaluating its physicochemical characteristics.

PubMed

Martusevich, A K; Kamakin, N F

2007-03-01

Using an integral qualitative and quantitative approach to the studies of initiation of the biological material crystallogenesis, we showed in experiments with normal human saliva that the external characteristics of biological fluid (pH, osmolality, and environmental temperature) determine the results of crystallization (tesigraphic facies). The main external (macroenvironment) and inner (microenvironment) factors of biological fluid crystal formation, determining specific features of the tesigraphic facies, were distinguished and classified. The informative value of differential analysis of biomaterial properties by means of modulating the environmental conditions is established.

[Characteristics of Cannabis sativa L.: seed morphology, germination and growth characteristics, and distinction from Hibiscus cannabinus L].

PubMed

Yoshimatsu, Kayo; Kitazawa, Takashi; Kawano, Noriaki; Iida, Osamu; Kawahara, Nobuo

2010-02-01

Illegal cannabis (Cannabis sativa L.) cultivation is still a social problem worldwide. Fifty inquiries on cannabis that Research Center for Medicinal Plant Resources (Tsukuba Division) received between January 1, 2000 and March 31, 2009 were itemized in to 8 categories; 1: seed identification, 2: plant identification, 3: indoor cultivation, 4: outdoor cultivation, 5: germination and growth characteristics, 6: expected amount of cannabis products derived from illegal cannabis plant, 7: non-narcotic cannabis and 8: usage of medicinal cannabis. Top three inquiries were 1: seed identification (16 cases), 3: indoor cultivation (10 cases) and 4: outdoor cultivation (6 cases). Characteristics of cannabis, namely seed morphology, germination and growth characteristics, and distinction from kenaf (Hibiscus cannabinus L.) that is frequently misjudged as cannabis, were studied to contribute for prevention of illegal cannabis cultivation.

Morphological study of the lingual papillae of the giant panda (Ailuropoda melanoleuca) by scanning electron microscopy

PubMed Central

Pastor, J F; Barbosa, M; De Paz, F J

2008-01-01

Due to the scarcity of giant pandas, there are few descriptions of their morphology and even fewer of their microscopic anatomy and the ultrastructure of their organs. In this study of the complete tongue of an adult male giant panda, we describe the morphology of its lingual surface, the different types of papillae, their characteristics and topographic distribution. It was seen that there are four main types of lingual papillae: filiform, conical, fungiform and vallate. There was no sign of foliate papillae, tuberculum intermolare or sublingua. Papilla distribution was not limited to the dorsum of the tongue, but was also seen on the anterior and ventral surfaces of the tongue. In the anterior third of the midline there is a smooth area with no papillae at all. Morphology of the microgrooves and pores is similar to that observed in other mammals. The papillae share characteristics encountered in Carnivora and herbivorous species of mammals. A narrow bamboo-based diet and specialized manner of eating have together resulted in modification of the tongue of a carnivoran, giving it some characteristics typical of an herbivore. PMID:18254792

On factors structuring the flatfish assemblage in the southern North Sea

NASA Astrophysics Data System (ADS)

Piet, G. J.; Pfisterer, A. B.; Rijnsdorp, A. D.

1998-09-01

Ten species of flatfish were studied to see to what extent interspecific competition influences their diet or spatial distribution and whether the potential of these flatfish species to avoid interspecific competition through resource partitioning is constrained by specific morphological characteristics. For this, seven morphological characteristics were measured, diet composition was determined from gut content analyses and overlap in distribution was determined from the co-occurrence in trawl hauls. Canonical correspondence analysis revealed the morphological characteristics that were most strongly correlated with the diet composition. Based on these findings the mouth gape was considered to be the most important morphological constraint affecting the choice of food. Two resource dimensions were distinguished along which interspecific competition can act on the flatfish assemblage: the trophic dimension (diet composition) and the spatial dimension (distribution). Resource partitioning was observed along both dimensions separately and, more importantly, the degree of resource partitioning along the two dimensions was negatively correlated. Especially the latter was considered strong circumstantial evidence that interspecific competition is a major factor structuring the flatfish assemblage. Resource partitioning along the two resource dimensions increased with decreasing mouth gape, suggesting that interspecific competition mainly acts on the small-mouthed fish, i.e. juveniles.

Interactive effects of phosphorus deficiency and exogenous auxin on root morphological and physiological traits in white lupin (Lupinus albus L.).

PubMed

Tang, Hongliang; Shen, Jianbo; Zhang, Fusuo; Rengel, Zed

2013-04-01

White lupin (Lupinus albus) exhibits strong root morphological and physiological responses to phosphorus (P) deficiency and auxin treatments, but the interactive effects of P and auxin in regulating root morphological and physiological traits are not fully understood. This study aimed to assess white lupin root traits as influenced by P (0 or 250 μmol L(-1)) and auxin (10(-8) mol L(-1) NAA) in nutrient solution. Both P deficiency and auxin treatments significantly altered root morphological traits, as evidenced by reduced taproot length, increased number and density of first-order lateral roots, and enhanced cluster-root formation. Changes in root physiological traits were also observed, i.e., increased proton, citrate, and acid phosphatase exudation. Exogenous auxin enhanced root responses and sensitivity to P deficiency. A significant interplay exists between P and auxin in the regulation of root morphological and physiological traits. Principal component analysis showed that P availability explained 64.8% and auxin addition 21.3% of the total variation in root trait parameters, indicating that P availability is much more important than auxin in modifying root responses of white lupin. This suggests that white lupin can coordinate root morphological and physiological responses to enhance acquisition of P resources, with an optimal trade-off between root morphological and physiological traits regulated by external stimuli such as P availability and auxin.

How the Parent-Child Relationship Affects Externalizing, Internalizing, and Adaptive Behavior Development in Autism

ERIC Educational Resources Information Center

Levenson, Lauren Nicole

2017-01-01

The purpose of this study was to examine the relationship between parent-child relationship characteristics (attachment, involvement, discipline practices, parenting confidence, and relational frustration) and behavioral outcomes (internalizing, externalizing, and adaptive) in children with autism spectrum disorder (ASD). ASD presents pervasive…

Teacher-Child Relationships and Children's Externalizing Behaviors in Head Start

ERIC Educational Resources Information Center

Whittaker, Jessica E. Vick; Jones Harden, Brenda

2010-01-01

This study explored the association between teacher-child relationship quality and Head Start children's externalizing behaviors. We also investigated the associations among teacher, student, and classroom characteristics and teacher-child relationship quality. Data were gathered from 100 Head Start children and their teachers. Teacher-child…

Morphology-based optical separation of subpopulations from a heterogeneous murine breast cancer cell line.

PubMed

Tamura, Masato; Sugiura, Shinji; Takagi, Toshiyuki; Satoh, Taku; Sumaru, Kimio; Kanamori, Toshiyuki; Okada, Tomoko; Matsui, Hirofumi

2017-01-01

Understanding tumor heterogeneity is an urgent and unmet need in cancer research. In this study, we used a morphology-based optical cell separation process to classify a heterogeneous cancer cell population into characteristic subpopulations. To classify the cell subpopulations, we assessed their morphology in hydrogel, a three-dimensional culture environment that induces morphological changes according to the characteristics of the cells (i.e., growth, migration, and invasion). We encapsulated the murine breast cancer cell line 4T1E, as a heterogeneous population that includes highly metastatic cells, in click-crosslinkable and photodegradable gelatin hydrogels, which we developed previously. We observed morphological changes within 3 days of encapsulating the cells in the hydrogel. We separated the 4T1E cell population into colony- and granular-type cells by optical separation, in which local UV-induced degradation of the photodegradable hydrogel around the target cells enabled us to collect those cells. The obtained colony- and granular-type cells were evaluated in vitro by using a spheroid assay and in vivo by means of a tumor growth and metastasis assay. The spheroid assay showed that the colony-type cells formed compact spheroids in 2 days, whereas the granular-type cells did not form spheroids. The tumor growth assay in mice revealed that the granular-type cells exhibited lower tumor growth and a different metastasis behavior compared with the colony-type cells. These results suggest that morphology-based optical cell separation is a useful technique to classify a heterogeneous cancer cell population according to its cellular characteristics.

External costs of risky health behaviors associated with leading actual causes of death in the U.S.: a review of the evidence and implications for future research.

PubMed

Zohrabian, Armineh; Philipson, Tomas J

2010-06-01

This paper reviews the evidence on external costs of risky behaviors in the U.S. and provides a framework for estimating them. External costs arise when a person does not bear all the costs of his or her behavior. They provide one of the strongest rationales for government interventions. Although the earlier estimates of external costs no longer have policy relevance, they demonstrated that the existence of external costs was an empirical question. We recommend that the estimates of external costs be updated as insurance structures, environments, and knowledge about these behaviors change. The general aspects of external costs may apply to countries other than the U.S. after taking into account differences in institutional, policy and epidemiological characteristics.

Morphological characteristics of waste polyethylene/polypropylene plastics during pyrolysis and representative morphological signal characterizing pyrolysis stages.

PubMed

Wang, H; Chen, D; Yuan, G; Ma, X; Dai, X

2013-02-01

In this work, the morphological characteristics of waste polyethylene (PE)/polypropylene (PP) plastics during their pyrolysis process were investigated, and based on their basic image changing patterns representative morphological signals describing the pyrolysis stages were obtained. PE and PP granules and films were used as typical plastics for testing, and influence of impurities was also investigated. During pyrolysis experiments, photographs of the testing samples were taken sequentially with a high-speed infrared camera, and the quantitative parameters that describe the morphological characteristics of these photographs were explored using the "Image Pro Plus (v6.3)" digital image processing software. The experimental results showed that plastics pyrolysis involved four stages: melting, two stages of decomposition which are characterized with bubble formation caused by volatile evaporating, and ash deposition; and each stage was characterized with its own phase changing behaviors and morphological features. Two stages of decomposition are the key step of pyrolysis since they took up half or more of the reaction time; melting step consumed another half of reaction time in experiments when raw materials were heated up from ambient temperatures; and coke-like deposition appeared as a result of decomposition completion. Two morphological signals defined from digital image processing, namely, pixel area of the interested reaction region and bubble ratio (BR) caused by volatile evaporating were found to change regularly with pyrolysis stages. In particular, for all experimental scenarios with plastics films and granules, the BR curves always exhibited a slowly drop as melting started and then a sharp increase followed by a deep decrease corresponding to the first stage of intense decomposition, afterwards a second increase - drop section corresponding to the second stage of decomposition appeared. As ash deposition happened, the BR dropped to zero or very low values. When impurities were involved, the shape of BR curves showed that intense decomposition started earlier but morphological characteristics remained the same. In addition, compared to parameters such as pressure, the BR reflects reaction stages better and its change with pyrolysis process of PE/PP plastics with or without impurities was more intrinsically process correlated; therefore it can be adopted as a signal for pyrolysis process characterization, as well as offering guide to process improvement and reactor design. Copyright © 2012 Elsevier Ltd. All rights reserved.

Controlling the Morphology of Side Chain Liquid Crystalline Block Copolymer Thin Films through Variations in Liquid Crystalline Content

PubMed Central

Verploegen, Eric; Zhang, Tejia; Jung, Yeon Sik; Ross, Caroline; Hammond, Paula T.

2009-01-01

In this paper we describe methods for manipulating the morphology of side-chain liquid crystalline block copolymers through variations in the liquid crystalline content. By systematically controlling the covalent attachment of side chain liquid crystals to a block copolymer (BCP) backbone, the morphology of both the liquid crystalline (LC) mesophase and the phase segregated BCP microstructures can be precisely manipulated. Increases in LC functionalization lead to stronger preferences for the anchoring of the LC mesophase relative to the substrate and the inter-material dividing surface (IMDS). By manipulating the strength of these interactions the arrangement and ordering of the ultrathin film block copolymer nanostructures can be controlled, yielding a range of morphologies that includes perpendicular and parallel cylinders, as well as both perpendicular and parallel lamellae. Additionally, we demonstrate the utilization of selective etching to create a nanoporous liquid crystalline polymer thin film. The unique control over the orientation and order of the self-assembled morphologies with respect to the substrate will allow for the custom design of thin films for specific nano-patterning applications without manipulation of the surface chemistry or the application of external fields. PMID:18763835

Ontogeny and function of the fifth limb in Cypridocopain ostracods.

PubMed

Kaji, Tomonari

2010-08-01

The exoskeleton of arthropods undergoes reformation at every molting. Accordingly, external morphology can metamorphose through molting. In some crustaceans, the function of appendages is modified through ontogeny. These morphological modifications require accordant modification of the correlation between different body parts because the morphological function depends on the combined correlation between different parts. In the case of crustacean morphology, exoskeleton and muscles are correlated to each other. The functional morphology of the fifth limb of cypridoid ostracods transforms from "walking leg + mouthparts (+ possibly respiratory parts)" to "mouthparts + respiratory parts + grasping hook (in males only)" through ontogeny. In this study, the three-dimensional structures of the exoskeleton and muscular systems were observed by confocal laser-scanning microscopy in some species of suborder Cypridocopina. The muscular system is reportedly not changed by the ontogeny of appendages in females, but it does change in males. Furthermore, regional cell proliferation, which was detected previously, represented the causal factor of exoskeletal modification. I therefore conclude that the enlarged endite in the female fifth limb is produced by exoskeletal modification based on regional cell proliferation, rather than by a change in the muscular system. In contrast, modification in the male requires a change in the muscular system in addition to exoskeletal modification.

Relationships between the morphology and thermoresponsive behavior in micro/nanostructured thermosetting matrixes containing a 4'-(hexyloxy)-4-biphenylcarbonitrile liquid crystal.

PubMed

Tercjak, Agnieszka; Mondragon, Iñaki

2008-10-07

Meso/nanostructured thermoresponsive thermosetting materials based on an epoxy resin modified with two different molecular weight amphiphilic poly(styrene- block-ethylene oxide) block copolymers (PSEO) and a low molecular weight liquid crystal, 4'-(hexyloxy)-4-biphenylcarbonitrile (HOBC), were investigated. A strong influence of the addition of PSEO on the morphology generated in HOBC--(diglicydyl ether of bisphenol A epoxy resin/ m-xylylenediamine) was detected, especially in the case of the addition of PSEO block copolymers with a higher PEO-block content and a lower molecular weight. The morphologies generated in the ternary systems also influenced the thermoresponsive behavior of the HOBC separated phase provoked by applying an external field, such as a temperature gradient and an electrical field. Thermal analysis of the investigated materials allowed for a better understanding of the relationships between generated morphology/thermo-optical properties/PSEO:HOBC ratio, and HOBC content. Controlling the relationship between the morphology and thermoresponsive behavior in micro/nanostructured thermosetting materials based on a 4'-(hexyloxy)-4-biphenylcarbonitrile liquid crystal allows the development of materials which can find application in thermo- and in some cases electroresponsive devices, with a high contrast ratio between transparent and opaque states.

Controlling the morphology of side chain liquid crystalline block copolymer thin films through variations in liquid crystalline content.

PubMed

Verploegen, Eric; Zhang, Tejia; Jung, Yeon Sik; Ross, Caroline; Hammond, Paula T

2008-10-01

In this paper, we describe methods for manipulating the morphology of side-chain liquid crystalline block copolymers through variations in the liquid crystalline content. By systematically controlling the covalent attachment of side chain liquid crystals to a block copolymer (BCP) backbone, the morphology of both the liquid crystalline (LC) mesophase and the phase-segregated BCP microstructures can be precisely manipulated. Increases in LC functionalization lead to stronger preferences for the anchoring of the LC mesophase relative to the substrate and the intermaterial dividing surface. By manipulating the strength of these interactions, the arrangement and ordering of the ultrathin film block copolymer nanostructures can be controlled, yielding a range of morphologies that includes perpendicular and parallel cylinders, as well as both perpendicular and parallel lamellae. Additionally, we demonstrate the utilization of selective etching to create a nanoporous liquid crystalline polymer thin film. The unique control over the orientation and order of the self-assembled morphologies with respect to the substrate will allow for the custom design of thin films for specific nanopatterning applications without manipulation of the surface chemistry or the application of external fields.

Role of external torque in the formation of ion thermal internal transport barriers

NASA Astrophysics Data System (ADS)

Jhang, Hogun; Kim, S. S.; Diamond, P. H.

2012-04-01

We present an analytic study of the impact of external torque on the formation of ion internal transport barriers (ITBs). A simple analytic relation representing the effect of low external torque on transport bifurcations is derived based on a two field transport model of pressure and toroidal momentum density. It is found that the application of an external torque can either facilitate or hamper bifurcation in heat flux driven plasmas depending on its sign relative to the direction of intrinsic torque. The ratio between radially integrated momentum (i.e., external torque) density to power input is shown to be a key macroscopic control parameter governing the characteristics of bifurcation.

Research on width control of Metal Fused-coating Additive Manufacturing based on active control

NASA Astrophysics Data System (ADS)

Ren, Chuan qi; Wei, Zheng ying; Wang, Xin; Du, Jun; Zhang, Shan; Zhang, Zhitong; Bai, Hao

2017-12-01

Given the stability of the shape of the forming layer is one of the key problems that affect the final quality of the sample morphology, taking a study on the forming process and the control method of morphology make a significant difference to metal fused-coating additive manufacturing (MFCAM) in achieving the efficient and stable forming. To improve the quality and precision of the samples of single-layer single pass, a control method of morphology based on active control was established by this paper. The real-time acquisition of image was realized by CCD and the characteristics of morphology of the forming process were simultaneously extracted. Making analysis of the characteristics of the width during the process, the relationship between the relative difference of different frames and moving speed was given. A large number of experiments are used to verify the response speed and accuracy of the system. The results show that the active system can improve the morphology of the sample and the smoothness of the width of the single channel, and increase the uniformity of width by 55.16%.

Morphological Integration of Soft-Tissue Facial Morphology in Down Syndrome and Siblings

PubMed Central

Starbuck, John; Reeves, Roger H.; Richtsmeier, Joan

2011-01-01

Down syndrome (DS), resulting from trisomy of chromosome 21, is the most common live-born human aneuploidy. The phenotypic expression of trisomy 21 produces variable, though characteristic, facial morphology. Although certain facial features have been documented quantitatively and qualitatively as characteristic of DS (e.g., epicanthic folds, macroglossia, and hypertelorism), all of these traits occur in other craniofacial conditions with an underlying genetic cause. We hypothesize that the typical DS face is integrated differently than the face of non-DS siblings, and that the pattern of morphological integration unique to individuals with DS will yield information about underlying developmental associations between facial regions. We statistically compared morphological integration patterns of immature DS faces (N = 53) with those of non-DS siblings (N = 54), aged 6–12 years using 31 distances estimated from 3D coordinate data representing 17 anthropometric landmarks recorded on 3D digital photographic images. Facial features are affected differentially in DS, as evidenced by statistically significant differences in integration both within and between facial regions. Our results suggest a differential affect of trisomy on facial prominences during craniofacial development. PMID:21996933

Morphological integration of soft-tissue facial morphology in Down Syndrome and siblings.

PubMed

Starbuck, John; Reeves, Roger H; Richtsmeier, Joan

2011-12-01

Down syndrome (DS), resulting from trisomy of chromosome 21, is the most common live-born human aneuploidy. The phenotypic expression of trisomy 21 produces variable, though characteristic, facial morphology. Although certain facial features have been documented quantitatively and qualitatively as characteristic of DS (e.g., epicanthic folds, macroglossia, and hypertelorism), all of these traits occur in other craniofacial conditions with an underlying genetic cause. We hypothesize that the typical DS face is integrated differently than the face of non-DS siblings, and that the pattern of morphological integration unique to individuals with DS will yield information about underlying developmental associations between facial regions. We statistically compared morphological integration patterns of immature DS faces (N = 53) with those of non-DS siblings (N = 54), aged 6-12 years using 31 distances estimated from 3D coordinate data representing 17 anthropometric landmarks recorded on 3D digital photographic images. Facial features are affected differentially in DS, as evidenced by statistically significant differences in integration both within and between facial regions. Our results suggest a differential affect of trisomy on facial prominences during craniofacial development. 2011 Wiley Periodicals, Inc.

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.

Assessment of the need for a cardiac morphology curriculum for paediatric cardiology fellows.

PubMed

Rogers, Lindsay S; Klein, Melissa; James, Jeanne; FitzGerald, Michael

2017-07-01

Expert knowledge of cardiac malformations is essential for paediatric cardiologists. Current cardiac morphology fellowship teaching format, content, and nomenclature are left up to the discretion of the individual fellowship programmes. We aimed to assess practices and barriers in morphology education, perceived effectiveness of current curricula, and preferences for a standardised fellow morphology curriculum. A web-based survey was developed de novo and administered anonymously via e-mail to all paediatric cardiology fellowship programme directors and associate directors in the United States of America; leaders were asked to forward the survey to fellows. A total of 35 directors from 32 programmes (51%) and 66 fellows responded. Curriculum formats varied: 28 (88%) programmes utilised pathological specimens, 25 (78%) invited outside faculty, and 16 (50%) utilised external conferences. Director nomenclature preferences were split - 6 (19%) Andersonian, 8 (25%) Van Praaghian, and 18 (56%) mixed. Barriers to morphology education included time and inconsistent nomenclature. One-third of directors reported that <90% of recent fellow graduates had adequate abilities to apply segmental anatomy, identify associated cardiac lesions, or communicate complex CHD. More structured teaching, protected time, and specimens were suggestions to improve curricula. Almost 75% would likely adopt/utilise an online morphology curriculum. Cardiac morphology training varies in content and format among fellowships. Inconsistent nomenclature exists, and inadequate morphology knowledge is perceived to contribute to communication failures, both have potential patient safety implications. There is an educational need for a common, online cardiac morphology curriculum that could allow for fellow assessment of competency and contribute to more standardised communication in the field of paediatric cardiology.

The Protective Effects of Adaptability, Study Skills, and Social Skills on Externalizing Student-Teacher Relationships

ERIC Educational Resources Information Center

Fisher, Sycarah D.; Reynolds, Jennifer L.; Sheehan, Chelsea E.

2016-01-01

Although students with externalizing behaviors inherently exhibit behaviors that contribute to poor teacher relationships, little research has examined the positive characteristics these students may possess that serve to facilitate positive teacher relationships. This study explores the moderating effects of adaptability, social skills, and study…

Measurement of red blood cell mechanics during morphological changes

PubMed Central

Park, YongKeun; Best, Catherine A.; Badizadegan, Kamran; Dasari, Ramachandra R.; Feld, Michael S.; Kuriabova, Tatiana; Henle, Mark L.; Levine, Alex J.; Popescu, Gabriel

2010-01-01

The human red blood cell (RBC) membrane, a fluid lipid bilayer tethered to an elastic 2D spectrin network, provides the principal control of the cell’s morphology and mechanics. These properties, in turn, influence the ability of RBCs to transport oxygen in circulation. Current mechanical measurements of RBCs rely on external loads. Here we apply a noncontact optical interferometric technique to quantify the thermal fluctuations of RBC membranes with 3 nm accuracy over a broad range of spatial and temporal frequencies. Combining this technique with a new mathematical model describing RBC membrane undulations, we measure the mechanical changes of RBCs as they undergo a transition from the normal discoid shape to the abnormal echinocyte and spherical shapes. These measurements indicate that, coincident with this morphological transition, there is a significant increase in the membrane’s shear, area, and bending moduli. This mechanical transition can alter cell circulation and impede oxygen delivery. PMID:20351261

Three-dimensional imaging of dislocation dynamics during the hydriding phase transformation

NASA Astrophysics Data System (ADS)

Ulvestad, A.; Welland, M. J.; Cha, W.; Liu, Y.; Kim, J. W.; Harder, R.; Maxey, E.; Clark, J. N.; Highland, M. J.; You, H.; Zapol, P.; Hruszkewycz, S. O.; Stephenson, G. B.

2017-05-01

Crystallographic imperfections significantly alter material properties and their response to external stimuli, including solute-induced phase transformations. Despite recent progress in imaging defects using electron and X-ray techniques, in situ three-dimensional imaging of defect dynamics remains challenging. Here, we use Bragg coherent diffractive imaging to image defects during the hydriding phase transformation of palladium nanocrystals. During constant-pressure experiments we observe that the phase transformation begins after dislocation nucleation close to the phase boundary in particles larger than 300 nm. The three-dimensional phase morphology suggests that the hydrogen-rich phase is more similar to a spherical cap on the hydrogen-poor phase than to the core-shell model commonly assumed. We substantiate this using three-dimensional phase field modelling, demonstrating how phase morphology affects the critical size for dislocation nucleation. Our results reveal how particle size and phase morphology affects transformations in the PdH system.

Craniofacial morphology of Homo floresiensis: description, taxonomic affinities, and evolutionary implication.

PubMed

Kaifu, Yousuke; Baba, Hisao; Sutikna, Thomas; Morwood, Michael J; Kubo, Daisuke; Saptomo, E Wahyu; Jatmiko; Awe, Rokhus Due; Djubiantono, Tony

2011-12-01

This paper describes in detail the external morphology of LB1/1, the nearly complete and only known cranium of Homo floresiensis. Comparisons were made with a large sample of early groups of the genus Homo to assess primitive, derived, and unique craniofacial traits of LB1 and discuss its evolution. Principal cranial shape differences between H. floresiensis and Homo sapiens are also explored metrically. The LB1 specimen exhibits a marked reductive trend in its facial skeleton, which is comparable to the H. sapiens condition and is probably associated with reduced masticatory stresses. However, LB1 is craniometrically different from H. sapiens showing an extremely small overall cranial size, and the combination of a primitive low and anteriorly narrow vault shape, a relatively prognathic face, a rounded oval foramen that is greatly separated anteriorly from the carotid canal/jugular foramen, and a unique, tall orbital shape. Whereas the neurocranium of LB1 is as small as that of some Homo habilis specimens, it exhibits laterally expanded parietals, a weak suprameatal crest, a moderately flexed occipital, a marked facial reduction, and many other derived features that characterize post-habilis Homo. Other craniofacial characteristics of LB1 include, for example, a relatively narrow frontal squama with flattened right and left sides, a marked frontal keel, posteriorly divergent temporal lines, a posteriorly flexed anteromedial corner of the mandibular fossa, a bulbous lateral end of the supraorbital torus, and a forward protruding maxillary body with a distinct infraorbital sulcus. LB1 is most similar to early Javanese Homo erectus from Sangiran and Trinil in these and other aspects. We conclude that the craniofacial morphology of LB1 is consistent with the hypothesis that H. floresiensis evolved from early Javanese H. erectus with dramatic island dwarfism. However, further field discoveries of early hominin skeletal remains from Flores and detailed analyses of the finds are needed to understand the evolutionary history of this endemic hominin species. Copyright © 2011 Elsevier Ltd. All rights reserved.

Computation of high Reynolds number internal/external flows

NASA Technical Reports Server (NTRS)

Cline, M. C.; Wilmoth, R. G.

1981-01-01

A general, user oriented computer program, called VNAP2, was developed to calculate high Reynolds number, internal/ external flows. The VNAP2 program solves the two dimensional, time dependent Navier-Stokes equations. The turbulence is modeled with either a mixing-length, a one transport equation, or a two transport equation model. Interior grid points are computed using the explicit MacCormack Scheme with special procedures to speed up the calculation in the fine grid. All boundary conditions are calculated using a reference plane characteristic scheme with the viscous terms treated as source terms. Several internal, external, and internal/external flow calculations are presented.

Computation of high Reynolds number internal/external flows

NASA Technical Reports Server (NTRS)

Cline, M. C.; Wilmoth, R. G.

1981-01-01

A general, user oriented computer program, called VNAF2, developed to calculate high Reynolds number internal/external flows is described. The program solves the two dimensional, time dependent Navier-Stokes equations. Turbulence is modeled with either a mixing length, a one transport equation, or a two transport equation model. Interior grid points are computed using the explicit MacCormack scheme with special procedures to speed up the calculation in the fine grid. All boundary conditions are calculated using a reference plane characteristic scheme with the viscous terms treated as source terms. Several internal, external, and internal/external flow calculations are presented.

The ROCK isoforms differentially regulate the morphological characteristics of carcinoma cells.

PubMed

Jerrell, Rachel J; Leih, Mitchell J; Parekh, Aron

2017-06-26

Rho-associated kinase (ROCK) activity drives cell migration via actomyosin contractility. During invasion, individual cancer cells can transition between 2 modes of migration, mesenchymal and amoeboid. Changes in ROCK activity can cause a switch between these migration phenotypes which are defined by distinct morphologies. However, recent studies have shown that the ROCK isoforms are not functionally redundant as previously thought. Therefore, it is unclear whether the ROCK isoforms play different roles in regulating migration phenotypes. Here, we found that ROCK1 and ROCK2 differentially regulate carcinoma cell morphology resulting in intermediate phenotypes that share some mesenchymal and amoeboid characteristics. These findings suggest that the ROCK isoforms play unique roles in the phenotypic plasticity of mesenchymal carcinoma cells which may have therapeutic implications.

Morphology, physiology, genetics, enigmas, and status of an extremely rare tree: Mutant tanoak

Treesearch

Philip M. McDonald; Jianwei Zhang; Randy S. Senock; Jessica W. Wright

2013-01-01

Important physical characteristics, morphological attributes, physiological functions, and genetic properties of mutant tanoak, Notholithocarpus densiflorus f. attenuato-dentatus (Fagaceae), and normal tanoak, Notholithocarpus densiflorus (Hook. & Arn.) Manos, Cannon & S. H. Oh, were studied on the Challenge...

Internal-external flow integration for a thin ejector-flapped wing section

NASA Technical Reports Server (NTRS)

Woolard, H. W.

1979-01-01

Thin airfoil theories of an ejector flapped wing section are reviewed. The global matching of the external airfoil flow with the ejector internal flow and the overall ejector flapped wing section aerodynamic performance are examined. Mathematical models of the external and internal flows are presented. The delineation of the suction flow coefficient characteristics are discussed. The idealized lift performance of an ejector flapped wing relative to a jet augmented flapped wing are compared.

Tissue-specific Requirements of β-Catenin in External Genitalia Development

PubMed Central

Lin, Congxing; Yin, Yan; Long, Fanxin; Ma, Liang

2008-01-01

SUMMARY External genitalia are body appendages specialized for internal fertilization. Its development can be divided into two phases, an early androgen-independent phase and a late androgen-dependant sexual differentiation phase. In the early phase, the embryonic anlage of external genitalia, the genital tubercle (GT), are morphologically identical in both sexes. Although congenital external genitalia malformations represent the second most common birth defect in humans, the genetic pathways governing early external genitalia development and urethra formation are poorly understood. Proper development of the GT requires coordinated outgrowth of the mesodermally-derived mesenchyme and extension of the endodermal urethra within an ectodermal epithelial capsule. Here we demonstrate that β-Catenin plays indispensable and distinct roles in each of the aforementioned three tissue layers in early androgen-independent GT development. WNT-β-Catenin signaling is required in the endodermal urethra to activate and maintain Fgf8 expression and direct GT outgrowth, as well as to maintain homeostasis of the urethra. Moreover, β-Catenin is required in the mesenchyme to promote cell proliferation. In contrast, β-Catenin is required in the ectoderm to maintain tissue integrity possibly through cell-cell adhesion during GT outgrowth. The fact that both endodermal and ectodermal β-Catenin knockout animals develop severe hypospadias in both sexes raises the possibility that deregulation of any of these functions can contribute to the etiology of congenital external genital defects in humans. PMID:18635608

Mullite and Mullite/ZrO2-7wt.%Y2O3 Powders for Thermal Spraying of Environmental Barrier Coatings

NASA Astrophysics Data System (ADS)

Garcia, E.; Mesquita-Guimarães, J.; Miranzo, P.; Osendi, M. I.; Wang, Y.; Lima, R. S.; Moreau, C.

2010-01-01

Mullite and mullite/ZrO2-7wt.%Y2O3 coatings could be thought among the main protective layers for environment barrier coatings (EBCs) to protect Si-based substrates in future gas turbine engines. Considering that feedstock of the compound powder is not commercially available, two powder processing routes Spray Drying (SD) and Flame Spheroidization (FS) were implemented for both types of powders. For each method the particle size, the morphology, and microstructure of the powder particles was determined. In addition, the effect of the heat treatment on the powder crystallinity and microstructure of FS powders was also investigated. To evaluate their suitability as feedstock materials, the powders were plasma sprayed and their in-flight particle characteristics monitored for coatings production. The powder morphology was correlated to the in-flight particle characteristics and splat morphology to gain insight about into the influence of powder characteristics on the coating formation.

Electrodeformation of multi-bilayer spherical concentric membranes by AC electric fields

NASA Astrophysics Data System (ADS)

Lira-Escobedo, J.; Arauz-Lara, J.; Aranda-Espinoza, H.; Adlerz, K.; Viveros-Mendez, P. X.; Aranda-Espinoza, S.

2017-09-01

It is now well established that external stresses alter the behaviour of cells, where such alterations can be as profound as changes in gene expression. A type of stresses of particular interest are those due to alternating-current (AC) electric fields. The effect of AC fields on cells is still not well understood, in particular it is not clear how these fields affect the cell nucleus and other organelles. Here, we propose that one possible mechanism is through the deformation of the membranes. In order to investigate the effect of AC fields on the morphological changes of the cell organelles, we modelled the cell as two concentric bilayer membranes. This model allows us to obtain the deformations induced by the AC field by balancing the elastic energy and the work done by the Maxwell stresses. Morphological phase diagrams are obtained as a function of the frequency and the electrical properties of the media and membranes. We demonstrate that the organelle shapes can be changed without modifying the shape of the external cell membrane and that the organelle deformation transitions can be used to measure, for example, the conductivity of the nucleus.

The use of CellaVision competency software for external quality assessment and continuing professional development.

PubMed

Horiuchi, Yuki; Tabe, Yoko; Idei, Mayumi; Bengtsson, Hans-Inge; Ishii, Kiyoshi; Horii, Takashi; Miyake, Kazunori; Satoh, Naotake; Miida, Takashi; Ohsaka, Akimichi

2011-07-01

Quality assessment of blood cell morphological testing, such as white blood cell (WBC) differential and its interpretation, is one of the most important and difficult assignments in haematology laboratories. A monthly survey was performed to assess the possible role of the proficiency testing program produced by CellaVision competency software (CCS) in external quality assessment (EQA) of the clinical laboratories of affiliated university hospitals and the effective utilisation of this program in continuing professional development (CPD). Four monthly proficiency surveys were conducted in collaboration with four clinical laboratories affiliated with the teaching hospitals of Juntendo University of Medicine in Japan. EQA results by the CCS proficiency testing program revealed a difference of performance levels of WBC differential and morphological interpretation and a discrepancy in the WBC differential criteria among laboratories. With regard to the utilisation of this proficiency program as a tool for CPD, this program successfully improved the performance of the low-scoring laboratories and less experienced individuals. The CCS proficiency testing program was useful for the quality assessment of laboratory performance, for education, and for the storage and distribution of cell images to be utilised for further standardisation and education.

Sociolinguistic Typology and Sign Languages.

PubMed

Schembri, Adam; Fenlon, Jordan; Cormier, Kearsy; Johnston, Trevor

2018-01-01

This paper examines the possible relationship between proposed social determinants of morphological 'complexity' and how this contributes to linguistic diversity, specifically via the typological nature of the sign languages of deaf communities. We sketch how the notion of morphological complexity, as defined by Trudgill (2011), applies to sign languages. Using these criteria, sign languages appear to be languages with low to moderate levels of morphological complexity. This may partly reflect the influence of key social characteristics of communities on the typological nature of languages. Although many deaf communities are relatively small and may involve dense social networks (both social characteristics that Trudgill claimed may lend themselves to morphological 'complexification'), the picture is complicated by the highly variable nature of the sign language acquisition for most deaf people, and the ongoing contact between native signers, hearing non-native signers, and those deaf individuals who only acquire sign languages in later childhood and early adulthood. These are all factors that may work against the emergence of morphological complexification. The relationship between linguistic typology and these key social factors may lead to a better understanding of the nature of sign language grammar. This perspective stands in contrast to other work where sign languages are sometimes presented as having complex morphology despite being young languages (e.g., Aronoff et al., 2005); in some descriptions, the social determinants of morphological complexity have not received much attention, nor has the notion of complexity itself been specifically explored.

Discrete event simulation model for external yard choice of import container terminal in a port buffer area

NASA Astrophysics Data System (ADS)

Rusgiyarto, Ferry; Sjafruddin, Ade; Frazila, Russ Bona; Suprayogi

2017-06-01

Increasing container traffic and land acquisition problem for terminal expansion leads to usage of external yard in a port buffer area. This condition influenced the terminal performance because a road which connects the terminal and the external yard was also used by non-container traffic. Location choice problem considered to solve this condition, but the previous research has not taken account a stochastic condition of container arrival rate and service time yet. Bi-level programming framework was used to find optimum location configuration. In the lower-level, there was a problem to construct the equation, which correlated the terminal operation and the road due to different time cycle equilibrium. Container moves from the quay to a terminal gate in a daily unit of time, meanwhile, it moves from the terminal gate to the external yard through the road in a minute unit of time. If the equation formulated in hourly unit equilibrium, it cannot catch up the container movement characteristics in the terminal. Meanwhile, if the equation formulated in daily unit equilibrium, it cannot catch up the road traffic movement characteristics in the road. This problem can be addressed using simulation model. Discrete Event Simulation Model was used to simulate import container flow processes in the container terminal and external yard. Optimum location configuration in the upper-level was the combinatorial problem, which was solved by Full Enumeration approach. The objective function of the external yard location model was to minimize user transport cost (or time) and to maximize operator benefit. Numerical experiment was run for the scenario assumption of two container handling ways, three external yards, and thirty-day simulation periods. Jakarta International Container Terminal (JICT) container characteristics data was referred for the simulation. Based on five runs which were 5, 10, 15, 20, and 30 repetitions, operation one of three available external yards (external yard - 3) was the optimum result. Apparently, the model confirmed the hypothesis that there was an optimum configuration of the external yard. Nevertheless, the model needs detail elaboration related to the objective function and the optimization constraint. It requires detail validation, in term of service time value, distribution pattern, and arrival rate in each unit server modeled in the next step of the research. The model gave unique and relatively consistent value of each run. It was indicated that the method has a chance to solve the research problem.

Morphology of gold and copper ion-plated coatings

NASA Technical Reports Server (NTRS)

Spalvins, T.

1978-01-01

Copper and gold films (0.2 to 2 microns thick) were ion plated onto polished 304-stainless-steel, glass, mica surfaces. These coatings were examined by SEM for defects in their morphological growth. Three types of defects were distinguished: nodular growth, abnormal or runaway growth, and spits. The cause for each type of defect was investigated. Nodular growth is due to inherent substrate microdefects, abnormal or runaway growth is due to external surface inclusions, and spits are due to nonuniform evaporation (ejection of droplets). All these defects induce stresses and produce porosity in the coatings and thus weaken their mechanical properties. During surface rubbing, large nodules are pulled out, leaving vacancies in the coatings.

Morphological and cytochemical indices of the stress reaction in the blood system under the influence of G-forces

NASA Technical Reports Server (NTRS)

Yurina, N. A.

1975-01-01

G-forces cause morphological and cytochemical changes characteristic of the stress reaction. The cytochemical changes in RNA content on lymphocytes, glycogen, and activity of oxidative enzymes in granulocytes are phasal in nature.

Steel characteristics measurement system using Barkhausen jump sum rate and magnetic field intensity and method of using same

DOEpatents

Kohn, Gabriel; Hicho, George; Swartzendruber, Lydon

1997-01-01

A steel hardness measurement system and method of using same are provided for measuring at least one mechanical or magnetic characteristic of a ferromagnetic sample as a function of at least one magnetic characteristic of the sample. A magnetic field generator subjects the sample to a variable external magnetic field. The magnetic field intensity of the magnetic field generated by the magnetic field generating means is measured and a signal sensor is provided for measuring Barkhausen signals from the sample when the sample is subjected to the external magnetic field. A signal processing unit calculates a jump sum rate first moment as a function of the Barkhausen signals measured by the signal sensor and the magnetic field intensity, and for determining the at least one mechanical or magnetic characteristic as a function of the jump sum rate first moment.

Steel characteristics measurement system using Barkhausen jump sum rate and magnetic field intensity and method of using same

DOEpatents

Kohn, G.; Hicho, G.; Swartzendruber, L.

1997-04-08

A steel hardness measurement system and method of using same are provided for measuring at least one mechanical or magnetic characteristic of a ferromagnetic sample as a function of at least one magnetic characteristic of the sample. A magnetic field generator subjects the sample to a variable external magnetic field. The magnetic field intensity of the magnetic field generated by the magnetic field generating means is measured and a signal sensor is provided for measuring Barkhausen signals from the sample when the sample is subjected to the external magnetic field. A signal processing unit calculates a jump sum rate first moment as a function of the Barkhausen signals measured by the signal sensor and the magnetic field intensity, and for determining the at least one mechanical or magnetic characteristic as a function of the jump sum rate first moment. 7 figs.

“Skin-Core-Skin” Structure of Polymer Crystallization Investigated by Multiscale Simulation

PubMed Central

Ruan, Chunlei

2018-01-01

“Skin-core-skin” structure is a typical crystal morphology in injection products. Previous numerical works have rarely focused on crystal evolution; rather, they have mostly been based on the prediction of temperature distribution or crystallization kinetics. The aim of this work was to achieve the “skin-core-skin” structure and investigate the role of external flow and temperature fields on crystal morphology. Therefore, the multiscale algorithm was extended to the simulation of polymer crystallization in a pipe flow. The multiscale algorithm contains two parts: a collocated finite volume method at the macroscopic level and a morphological Monte Carlo method at the microscopic level. The SIMPLE (semi-implicit method for pressure linked equations) algorithm was used to calculate the polymeric model at the macroscopic level, while the Monte Carlo method with stochastic birth-growth process of spherulites and shish-kebabs was used at the microscopic level. Results show that our algorithm is valid to predict “skin-core-skin” structure, and the initial melt temperature and the maximum velocity of melt at the inlet mainly affects the morphology of shish-kebabs. PMID:29659516

An elusive Neotropical giant, Hondurantemna chespiritoi gen. n. & sp. n. (Antemninae, Mantidae): a new lineage of mantises exhibiting an ontogenetic change in cryptic strategy.

PubMed

Rodrigues, Henrique M; Rivera, Julio; Reid, Neil; Svenson, Gavin J

2017-01-01

We present the description of a new genus and new species of praying mantis, Hondurantemna chespiritoi gen. n. & sp. n. This species of cryptic mantis, collected in National parks in Mexico and Honduras, remained unknown despite its considerable body size. Based on a phylogenetic analysis with molecular data and traditional morphological analysis, we place this new genus within Antemninae, a monotypic Mantidae subfamily. We update the subfamily concept for Antemninae and provide a key to the two genera. We describe the external morphology of immatures and adults of the new species as well as the genital complexes of both sexes and the ootheca of Antemna rapax . The observed morphological changes between immature and adult females suggests that the selection for an alternate strategy for crypsis is a response to size increase of the abdomen during development. Immatures exploit a stick/branch habitat based on their morphological appearance while adult females appear as a leaf to disguise the profile of the body.

Reversible electric-field manipulation of the adsorption morphology and magnetic anisotropy of small Fe and Co clusters on graphene

NASA Astrophysics Data System (ADS)

Tanveer, M.; Dorantes-Dávila, J.; Pastor, G. M.

2017-12-01

First-principles electronic calculations show how the adsorption morphology, orbital magnetism, and magnetic anisotropy energy (MAE) of small CoN and FeN clusters (N ≤3 ) on graphene (G) can be reversibly controlled under the action of an external electric field (EF). A variety of cluster-specific and EF-induced effects are revealed, including (i) perpendicular or canted adsorption configurations of the dimers and trimers, (ii) significant morphology-dependent permanent dipole moments and electric susceptibilities, (iii) EF-induced reversible transitions among the different metastable adsorption morphologies of Fe3 and Co3 on graphene, (iv) qualitative changes in the MAE landscape driven by structural changes, (v) colossal values of the magnetic anisotropy Δ E ≃45 meV per atom in Co2/G , (vi) EF-induced spin-reorientation transitions in Co3/G , and (vii) reversibly tunable coercive field and blocking temperatures, which in some cases allow a barrierless magnetization reversal of the cluster. These remarkable electric and magnetic fingerprints open new possibilities of characterizing and exploiting the size- and structural-dependent properties of magnetic nanostructures at surfaces.

GEITLERINEMA SPECIES (OSCILLATORIALES, CYANOBACTERIA) REVEALED BY CELLULAR MORPHOLOGY, ULTRASTRUCTURE, AND DNA SEQUENCING(1).

PubMed

Do Carmo Bittencourt-Oliveira, Maria; Do Nascimento Moura, Ariadne; De Oliveira, Mariana Cabral; Sidnei Massola, Nelson

2009-06-01

Geitlerinema amphibium (C. Agardh ex Gomont) Anagn. and G. unigranulatum (Rama N. Singh) Komárek et M. T. P. Azevedo are morphologically close species with characteristics frequently overlapping. Ten strains of Geitlerinema (six of G. amphibium and four of G. unigranulatum) were analyzed by DNA sequencing and transmission electronic and optical microscopy. Among the investigated strains, the two species were not separated with respect to cellular dimensions, and cellular width was the most varying characteristic. The number and localization of granules, as well as other ultrastructural characteristics, did not provide a means to discriminate between the two species. The two species were not separated either by geography or environment. These results were further corroborated by the analysis of the cpcB-cpcA intergenic spacer (PC-IGS) sequences. Given the fact that morphology is very uniform, plus the coexistence of these populations in the same habitat, it would be nearly impossible to distinguish between them in nature. On the other hand, two of the analyzed strains were distinct from all others based on the PC-IGS sequences, in spite of their morphological similarity. PC-IGS sequences indicate that these two strains could be a different species of Geitlerinema. Using morphology, cell ultrastructure, and PC-IGS sequences, it is not possible to distinguish G. amphibium and G. unigranulatum. Therefore, they should be treated as one species, G. unigranulatum as a synonym of G. amphibium. © 2009 Phycological Society of America.

Correlation of Rock Spectra with Quantitative Morphologic Indices: Evidence for a Single Rock Type at the Mars Pathfinder Landing Site

NASA Technical Reports Server (NTRS)

Yingst, R. A.; Biedermann, K. L.; Pierre, N. M.; Haldemann, A. F. C.; Johnson, J. R.

2005-01-01

The Mars Pathfinder (MPF) landing site was predicted to contain a broad sampling of rock types varying in mineralogical, physical, mechanical and geochemical characteristics. Although rocks have been divided into several spectral categories based on Imager for Mars Pathfinder (IMP) visible/near-infrared data, efforts in isolating and classifying spectral units among MPF rocks and soils have met with varying degrees of success, as many factors influencing spectral signatures cannot be quantified to a sufficient level to be removed. It has not been fully determined which spectral categories stem from intrinsic mineralogical differences between rocks or rock surfaces, and which result from factors such as physical or chemical weathering. This has made isolation of unique rock mineralogies difficult. Morphology, like composition, is a characteristic tied to the intrinsic properties and geologic and weathering history of rocks. Rock morphologies can be assessed quantitatively and compared with spectral data, to identify and classify rock types at the MPF landing site. They can also isolate actual rock spectra from spectral types that are surficial in origin, as compositions associated with mantling dust or chemical coatings would presumably not influence rock morphology during weathering events. We previously reported on an initial classification of rocks using the quantitative morphologic indices of size, roundness, sphericity and elongation. Here, we compare this database of rock characteristics with associated rock surface spectra to improve our ability to discriminate between spectra associated with rock types and those from other sources.

The impact of engineered log jams on bed morphology, flow characteristics and habitat diversity under low flow

NASA Astrophysics Data System (ADS)

Ockelford, A.; Crabbe, E.; Crowe Curran, J.; Parsons, D. R.; Shugar, D. H.; Burr, A.; Kennedy, K.; Coe, T.

2017-12-01

Wood jams are an important and ubiquitous feature of many river channels with their number, placement and spatial configuration determining their influence on channel morphology and flow characteristics. Further, engineered log jams are increasingly being constructed to develop, restore or maintain habitat diversity for key indicator specie such as salmon. However, questions remain as to the inter relationships between the logjams, the channel morphology, the flow characteristics and the habitat diversity under low flow conditions. Four engineered and one natural logjam were analyzed over a 3km reach of the South Fork Nooksack River, North Cascades National Park, USA during the summer low flow period. Non-intrusive three-dimensional topographic surveys of the river bed morphology surrounding the logjams was collected using a shallow water multibeam system. This was combined with terrestrial laser scans of the structure of the log jams above the waterline. Co-located high resolution flow velocity data was collected using an Acoustic Doppler Current Profiler. Discussion concentrates on providing a quantitative understanding of the effect of logjams on reach scale morphodynamics under low flow conditions. Multivariate statistical analysis of flow and topographic data in combination with log jam morphology allow the influences of the logjam on habitat suitability for key indicator species to be quantified. Results will be framed in terms of the effectiveness of the different logjam configurations on generating and promoting habitat diversity such as to aid future design and implementation.

Evolution processes of the corrosion behavior and structural characteristics of plasma electrolytic oxidation coatings on AZ31 magnesium alloy

NASA Astrophysics Data System (ADS)

Chen, Dong; Wang, Ruiqiang; Huang, Zhiquan; Wu, Yekang; Zhang, Yi; Wu, Guorui; Li, Dalong; Guo, Changhong; Jiang, Guirong; Yu, Shengxue; Shen, Dejiu; Nash, Philip

2018-03-01

Evolution processes of the corrosion behavior and structural characteristics of the plasma electrolytic oxidation (PEO) coated AZ31 magnesium alloy were investigated by using scanning electron microscope (SEM) equipped with energy dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD), potentio-dynamic polarization curves and electrochemical impedance spectroscopy (EIS) measurements. Detached coating samples were fabricated by an electrochemical method and more details of the internal micro-structure of coatings were clearly observed on the fractured cross-section morphologies of the samples compared to general polished cross-section morphologies. Evolution mechanisms of the coating corrosion behavior in relation to the evolution of micro-structural characteristics were discussed in detail.

DNA barcoding of wild edible mushrooms consumed by the ethnic tribes of India.

PubMed

Khaund, Polashree; Joshi, S R

2014-10-15

Wild edible mushrooms are consumed by the tribes of Meghalaya in the North-Eastern region of India, as part of their ethnic cuisine because of their favored organoleptic characteristics and traditionally known health benefits. Majority of these mushrooms have not yet been characterized in detail and are slowly shrinking in their natural habitats owing to anthropogenic factors and climate change. In the present study, representative specimens of ten morphologically distinct groups of wild edible mushrooms available in the traditional markets and their respective forest habitats, were subjected to multi-loci molecular characterization using SSU, ITS, RPB1 and RPB2 markers. The species identities inferred for the ten mushroom types using the SSU marker matched their morphological description in the case of four morphological groups only whereas the ITS marker successfully resolved the species identity for nine out of the ten mushroom groups under study. Both the protein coding gene markers RPB1 and RPB2 successfully resolved the species identity for three out of the ten morphologically distinct groups. Finally the most likely identity of the wild edible mushrooms under study has been suggested by matching their unique morphological characteristics with the generated DNA barcoding data. The present molecular characterization reveals the ten widely consumed wild mushroom types of Meghalaya, India to be Gomphus floccosus, Lactarius deliciosus, Lactarius volemus, Cantharellus cibarius, Tricholoma viridiolivaceum, Inocybe aff. sphaerospora, Laccaria vinaceoavellanea, Albatrellus ellisii, Ramaria maculatipes and Clavulina cristata. The final species identity generated by the ITS marker matched more accurately with the morphological characteristics/appearance of the specimens indicating the ITS region as a reliable barcode for identifying wild edible mushrooms. Copyright © 2014 Elsevier B.V. All rights reserved.

Statistical analysis of the time and space characteristic scales for large precipitating systems in the equatorial, tropical, sahelian and mid-latitude regions.

NASA Astrophysics Data System (ADS)

Duroure, Christophe; Sy, Abdoulaye; Baray, Jean luc; Van baelen, Joel; Diop, Bouya

2017-04-01

Precipitation plays a key role in the management of sustainable water resources and flood risk analyses. Changes in rainfall will be a critical factor determining the overall impact of climate change. We propose to analyse long series (10 years) of daily precipitation at different regions. We present the Fourier densities energy spectra and morphological spectra (i.e. probability repartition functions of the duration and the horizontal scale) of large precipitating systems. Satellite data from the Global precipitation climatology project (GPCP) and local pluviometers long time series in Senegal and France are used and compared in this work. For mid-latitude and Sahelian regions (North of 12°N), the morphological spectra are close to exponential decreasing distribution. This fact allows to define two characteristic scales (duration and space extension) for the precipitating region embedded into the large meso-scale convective system (MCS). For tropical and equatorial regions (South of 12°N) the morphological spectra are close to a Levy-stable distribution (power law decrease) which does not allow to define a characteristic scale (scaling range). When the time and space characteristic scales are defined, a "statistical velocity" of precipitating MCS can be defined, and compared to observed zonal advection. Maps of the characteristic scales and Levy-stable exponent over West Africa and south Europe are presented. The 12° latitude transition between exponential and Levy-stable behaviors of precipitating MCS is compared with the result of ECMWF ERA-Interim reanalysis for the same period. This morphological sharp transition could be used to test the different parameterizations of deep convection in forecast models.

Mechanical, thermal, morphological, and rheological characteristics of high performance 3D-printing lignin-based composites for additive manufacturing applications

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

Nguyen, Ngoc A.; Bowland, Christopher C.; Naskar, Amit K.

Here, the article presents different mechanical, thermal and rheological data corresponding to the morphological formation within various renewable lignin-based composites containing acrylonitrile butadiene styrene (ABS), acrylonitrile butadiene rubber (NBR41, 41 mol% nitrile content), and carbon fibers (CFs). The data of 3D-printing properties and morphology of 3D-printed layers of selected lignin-based composites are revealed.

Mechanical, thermal, morphological, and rheological characteristics of high performance 3D-printing lignin-based composites for additive manufacturing applications

DOE PAGES

Nguyen, Ngoc A.; Bowland, Christopher C.; Naskar, Amit K.

2018-05-29

Here, the article presents different mechanical, thermal and rheological data corresponding to the morphological formation within various renewable lignin-based composites containing acrylonitrile butadiene styrene (ABS), acrylonitrile butadiene rubber (NBR41, 41 mol% nitrile content), and carbon fibers (CFs). The data of 3D-printing properties and morphology of 3D-printed layers of selected lignin-based composites are revealed.

Parallel Evolution of Larval Feeding Behavior, Morphology, and Habitat in the Snail-Kiling fly Genus Tetanocera

NASA Astrophysics Data System (ADS)

Chapman, E. G.; Foote, B. A.; Malukiewicz, J.; Hoeh, W. R.

2005-05-01

Sciomyzid larvae (Diptera: Acalyptratae) display a wide range of feeding behaviors, typically preying on a wide variety of gastropods. The genus Tetanocera is particularly interesting because its species occupy five larval feeding groups with each species' larvae living in one of two habitat types (aquatic or terrestrial). We constructed a molecular phylogeny for Tetanocera, estimated evolutionary transitions in larval feeding behaviors and habitats that occurred during Tetanocera phylogenesis, and investigated potential correlations among larval habitat and morphological characteristics. Approximately 3800 base pairs (both mitochondrial and nuclear) of sequence data were used to build the phylogeny. Larval feeding groups and habitat type were mapped onto the phylogeny and pair-wise comparisons were used to evaluate potential associations between habitat and morphology. Feeding and habitat groups within Tetanocera were usually not monophyletic and it was estimated that Tetanocera lineages made at least three independent aquatic to terrestrial transitions. These parallel habitat shifts were typically accompanied by parallel character state changes in four morphological characteristics (larval color and three posterior spiracular disc characters). These larval habitat-morphology associations were statistically significant and consistent with the action of natural selection in facilitating the morphological changes that occurred during aquatic to terrestrial habitat transitions in Tetanocera.

Bilateral Internal Carotid Artery Occlusion, External Carotid Artery Stenosis, and Vertebral Artery Kinking: May It Be Asymptomatic?

PubMed

Fatic, Nikola; Jaffer, Usman; Ivana, Saicic; Gordana, Globarevic-Vukcevic; Markovic, Dragan; Kostic, Dusan; Davidovic, Lazar

2017-10-01

The clinical spectrum of internal carotid artery occlusion ranges from being a completely asymptomatic occlusion to a devastating stroke or death. The prevalence of asymptomatic internal carotid artery occlusion is unknown, particularly for bilateral occlusion. The distal branches of the external carotid artery anastomose with distal branches of the internal carotid artery provide important sources of collateral circulation to the brain. Stenosis of the external carotid artery with ipsilateral/bilateral internal occlusion may result in ischemic sequelae. Coiling or kinking of the vertebral artery is a rare morphological entity that is infrequently reported because it remains asymptomatic and has no clinical relevance. Currently, there is little evidence to support management strategies for this disease entity and no official recommendations for asymptomatic bilateral carotid artery occlusion. We present a case of a 62-year-old female with asymptomatic bilateral internal carotid artery occlusion, bilateral external carotid artery stenoses, and bilateral kinking of the vertebral artery at the V2 segment, who has been successfully managed conservatively for over 5 years. An individualized approach to management of patients with bilateral internal carotid artery occlusion, especially in combination with external carotid artery stenosis and elongation malformations of the vertebral artery is key to a successful strategy. Copyright © 2017 Elsevier Inc. All rights reserved.

Family and Child Characteristics Linking Neighborhood Context and Child Externalizing Behavior

ERIC Educational Resources Information Center

Roosa, Mark W.; Deng, Shiying; Ryu, Ehri; Lockhart Burrell, Ginger; Tein, Jenn-Yun; Jones, Sarah; Lopez, Vera; Crowder, Sakina

2005-01-01

Neighborhood conditions are related to children's externalizing behavior, although few processes that help explain this association have been identified. With data from 189 primarily low-income Anglo and Mexican American families, we tested a stress process model that included 3 potential mediators of this relationship. The results showed that…

76 FR 23281 - Bottom Mount Combination Refrigerator-Freezers From the Republic of Korea and Mexico: Initiation...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-04-26

... feel are relevant to the development of an accurate listing of physical characteristics. Specifically... two interior storage compartments accessible through one or more separate external doors or drawers or... external door or drawer is either a refrigerator compartment or convertible compartment, but is not a...

75 FR 64773 - Study Required by Section 989G(b) of the Dodd-Frank Act Regarding Compliance With Section 404(b...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-10-20

..., which addresses management's responsibility for reporting on the effectiveness of internal control over...) Quantitative and qualitative information about the trends of internal and external costs of having an external... over time; (3) Characteristics of internal controls, management's evaluation process and corporate...

Pyrolysis oil combustion in a horizontal box furnace with an externally mixed nozzle

USDA-ARS?s Scientific Manuscript database

Combustion characteristics of neat biomass fast-pyrolysis oil were studied in a horizontal combustion chamber with a rectangular cross-section. An air-assisted externally mixed nozzle known to successfully atomize heavy fuel oils was installed in a modified nominal 100 kW (350,000 BTU/h nominal cap...

76 FR 72440 - Bottom Mount Combination Refrigerator-Freezers From Korea and Mexico; Scheduling of the Final...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-11-23

... refrigeration using compression technology, with all of the following characteristics: (1) The cabinet contains... interior plastic liner, (e) wiring, and (f) insulation; (2) any assembled external doors designed for use... metal shell, (b) an interior plastic liner, and (c) insulation; and (3) any assembled external drawers...

Succession Planning in a Two-Year Technical College System

ERIC Educational Resources Information Center

Neefe, Diane Osterhaus

2009-01-01

The study explores the organizational characteristics of strategic planning, succession planning and career management and the processes impact on the hiring location of academic leaders from within the college, external to the college but within the system, and external to the system. The study was conducted in the 16 college Wisconsin…

Dysfunctional family environments and childhood psychopathology: the role of psychiatric comorbidity.

PubMed

Flores, Suzielle M; Salum, Giovanni A; Manfro, Gisele G

2014-09-01

The study of the association between specific characteristics of family environments and different types of psychopathology may contribute to our understanding of these complex disorders and ultimately inform therapeutics. To compare the family characteristics of four groups: typically developing children; children with anxiety disorders only; children with externalizing disorders only; and children with both anxiety and externalizing disorders. This study enrolled 115 individuals from the community. Child psychiatrists made psychiatric diagnoses using a structured clinical interview. The Family Environment scale was used to evaluate six domains of family function. The group with both anxiety and externalizing disorders had higher levels of conflict in family environment and lower levels of organization when compared with typically developing children. In addition, internalizing and externalizing symptoms were positively associated with conflict and negatively with organization. Maternal depressive and anxious symptoms were also associated with higher conflict and lower organization scores. An important between-group difference in comorbid cases of anxiety and behavioral disorders suggests that children with this comorbidity are potential candidates for family interventions to address family conflicts and organizational aspects.

Profiles of internalizing and externalizing symptoms associated with bullying victimization.

PubMed

Eastman, Meridith; Foshee, Vangie; Ennett, Susan; Sotres-Alvarez, Daniela; Reyes, H Luz McNaughton; Faris, Robert; North, Kari

2018-06-01

This study identified profiles of internalizing (anxiety and depression) and externalizing (delinquency and violence against peers) symptoms among bullying victims and examined associations between bullying victimization characteristics and profile membership. The sample consisted of 1196 bullying victims in grades 8-10 (M age  = 14.4, SD = 1.01) who participated in The Context Study in three North Carolina counties in Fall 2003. Five profiles were identified using latent profile analysis: an asymptomatic profile and four profiles capturing combinations of internalizing and externalizing symptoms. Associations between bullying characteristics and membership in symptom profiles were tested using multinomial logistic regression. More frequent victimization increased odds of membership in the two high internalizing profiles compared to the asymptomatic profile. Across all multinomial logistic regression models, when the high internalizing, high externalizing profile was the reference category, adolescents who received any type of bullying (direct, indirect, or dual) were more likely to be in this category than any others. Copyright © 2018 The Foundation for Professionals in Services for Adolescents. Published by Elsevier Ltd. All rights reserved.

Losses in Channels with Increased External Turbulence

NASA Technical Reports Server (NTRS)

Zaryankin, A. Y.; Soloveva, G. S.

1986-01-01

An approximate method for determining the effect of the level of turbulence on the aerodynamic characteristics of convergent and diffuser channels is examined. A momentum equation for the boundary layer is in the method, introducing external flow turbulence on the basis of experimental values of the coefficient of friction and the form factor. It is found that at significant levels of external turbulence, losses must be considered not only in the boundary layer but also in the central region of the channel.

Characteristics of Talented Dancers and Age Group Differences: Findings from the UK Centres for Advanced Training

ERIC Educational Resources Information Center

Walker, Imogen J.; Nordin-Bates, Sanna M.; Redding, Emma

2011-01-01

This study investigated differences in the characteristics of talented dancers in relation to age. Physical (handgrip muscular strength, leg muscular power, hamstring flexibility and external hip rotation), psychological (passion, self-esteem and anxiety) and social (the motivational climate) characteristics were assessed in 334 students enrolled…

The Relationship of Task Characteristics to Attitudes, Absenteeism, Stress and Performance Among College Students.

ERIC Educational Resources Information Center

Rousseau, Denise M.

In organizational settings, research has shown the relationship of task characteristics to attitudes and motivation. This study examines the external validity of the task characteristic-outcome relationship in an educational setting. Subjects were 206 undergraduate psychology students. They were given an inventory of seven task characteristics…

Strain-effect transistors: Theoretical study on the effects of external strain on III-nitride high-electron-mobility transistors on flexible substrates

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

Shervin, Shahab; Asadirad, Mojtaba; Materials Science and Engineering Program, University of Houston, Houston, Texas 77204

This paper presents strain-effect transistors (SETs) based on flexible III-nitride high-electron-mobility transistors (HEMTs) through theoretical calculations. We show that the electronic band structures of InAlGaN/GaN thin-film heterostructures on flexible substrates can be modified by external bending with a high degree of freedom using polarization properties of the polar semiconductor materials. Transfer characteristics of the HEMT devices, including threshold voltage and transconductance, are controlled by varied external strain. Equilibrium 2-dimensional electron gas (2DEG) is enhanced with applied tensile strain by bending the flexible structure with the concave-side down (bend-down condition). 2DEG density is reduced and eventually depleted with increasing compressive strainmore » in bend-up conditions. The operation mode of different HEMT structures changes from depletion- to enchantment-mode or vice versa depending on the type and magnitude of external strain. The results suggest that the operation modes and transfer characteristics of HEMTs can be engineered with an optimum external bending strain applied in the device structure, which is expected to be beneficial for both radio frequency and switching applications. In addition, we show that drain currents of transistors based on flexible InAlGaN/GaN can be modulated only by external strain without applying electric field in the gate. The channel conductivity modulation that is obtained by only external strain proposes an extended functional device, gate-free SETs, which can be used in electro-mechanical applications.« less

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

PubMed

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

2008-12-01

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

Effects of body conformation and udder morphology on milk yield of zebu cows in North region of Cameroon

PubMed Central

Mingoas, Kilekoung Jean-Pierre; Awah-Ndukum, Julius; Dakyang, Houinga; Zoli, Pagnah André

2017-01-01

Aim: The aim of the study was to assess the effect of udder morphological characteristics on milk yield in zebu cows of Cameroon. Materials and Methods: The diameter and height of the udder, length and diameter of the teat, and the milk yield were measured in 29 Djafun (Red Mbororo) and 19 Aku (White Fulani) cows in Louggueré zootechnical station in the North region of Cameroon. Results: Overall, strong positive correlation (rp=0.60) between the diameter (240.21±28.58 mm) and height (131.12±23.64 mm) of udders (p<0.001) and between length (39.51±6.44 mm) and diameter (19.85±3.08 mm) of teats (rp=0.78) were found in the zebu cows. Udder morphologic characteristics varied significantly (p<0.005) according to breed, lactation stage and parity, and height at whiters. There was significant (p<0.001) correlations between udder diameter (rp=0.541) and height (rp=0.549) with milk yield. Conclusion: This study ascertained udder morphological characteristics values in local zebu cows, and showed that udder size is strong and positively correlated to milk yield. The findings are useful in genetic improvement programs of zebu cows. PMID:28919680

Adsorption site analysis of impurity embedded single-walled carbon nanotube bundles

USGS Publications Warehouse

Agnihotri, S.; Mota, J.P.B.; Rostam-Abadi, M.; Rood, M.J.

2006-01-01

Bundle morphology and adsorptive contributions from nanotubes and impurities are studied both experimentally and by simulation using a computer-aided methodology, which employs a small physisorbed probe molecule to explore the porosity of nanotube samples. Grand canonical Monte Carlo simulation of nitrogen adsorption on localized sites of a bundle is carried out to predict adsorption in its accessible internal pore volume and on its external surface as a function of tube diameter. External adsorption is split into the contributions from the clean surface of the outermost nanotubes of the bundle and from the surface of the impurities. The site-specific isotherms are then combined into a global isotherm for a given sample using knowledge of its tube-diameter distribution obtained by Raman spectroscopy. The structural parameters of the sample, such as the fraction of open-ended nanotubes and the contributions from impurities and nanotube bundles to total external surface area, are determined by fitting the experimental nitrogen adsorption data to the simulated isotherm. The degree of closure between experimental and calculated adsorption isotherms for samples manufactured by two different methods, to provide different nanotube morphology and contamination level, further strengthens the validity and resulting interpretations based on the proposed approach. The average number of nanotubes per bundle and average bundle size, within a sample, are also quantified. The proposed method allows for extrapolation of adsorption properties to conditions where the purification process is 100% effective at removing all impurities and opening access to all intrabundle adsorption sites. ?? 2006 Elsevier Ltd. All rights reserved.

Automatic system for 3D reconstruction of the chick eye based on digital photographs.

PubMed

Wong, Alexander; Genest, Reno; Chandrashekar, Naveen; Choh, Vivian; Irving, Elizabeth L

2012-01-01

The geometry of anatomical specimens is very complex and accurate 3D reconstruction is important for morphological studies, finite element analysis (FEA) and rapid prototyping. Although magnetic resonance imaging, computed tomography and laser scanners can be used for reconstructing biological structures, the cost of the equipment is fairly high and specialised technicians are required to operate the equipment, making such approaches limiting in terms of accessibility. In this paper, a novel automatic system for 3D surface reconstruction of the chick eye from digital photographs of a serially sectioned specimen is presented as a potential cost-effective and practical alternative. The system is designed to allow for automatic detection of the external surface of the chick eye. Automatic alignment of the photographs is performed using a combination of coloured markers and an algorithm based on complex phase order likelihood that is robust to noise and illumination variations. Automatic segmentation of the external boundaries of the eye from the aligned photographs is performed using a novel level-set segmentation approach based on a complex phase order energy functional. The extracted boundaries are sampled to construct a 3D point cloud, and a combination of Delaunay triangulation and subdivision surfaces is employed to construct the final triangular mesh. Experimental results using digital photographs of the chick eye show that the proposed system is capable of producing accurate 3D reconstructions of the external surface of the eye. The 3D model geometry is similar to a real chick eye and could be used for morphological studies and FEA.

Field guide to Intermountain sedges

Treesearch

Emerenciana G. Hurd; Nancy L. Shaw; Joy Mastrogiuseppe; Lynda C. Smithman; Sherel Goodrich

1998-01-01

Descriptions of morphological characteristics, habitat, and geographic distributions are provided for 114 sedges (Carex spp.) of the Intermountain area. A dichotomous key, color photographs, line drawings, and discussions highlighting differences among similar species aid identification. An illustrated morphology, glossary, and index of common names simplify use. The...

Morphological and Physiological Alteration of Maize Root Architectures on Drought Stress.

USDA-ARS?s Scientific Manuscript database

Drought tolerance is a complex agronomic trait and root characteristics logically play an important role in determining the response of plants to drought stress. Research experiments were conducted to investigate genotypic variations in morphological and physiological responses of roots to drought s...

Astragalar Morphology of Selected Giraffidae

PubMed Central

2016-01-01

The artiodactyl astragalus has been modified to exhibit two trochleae, creating a double pullied structure allowing for significant dorso-plantar motion, and limited mediolateral motion. The astragalus structure is partly influenced by environmental substrates, and correspondingly, morphometric studies can yield paleohabitat information. The present study establishes terminology and describes detailed morphological features on giraffid astragali. Each giraffid astragalus exhibits a unique combination of anatomical characteristics. The giraffid astragalar morphologies reinforce previously established phylogenetic relationships. We find that the enlargement of the navicular head is a feature shared by all giraffids, and that the primitive giraffids possess exceptionally tall astragalar heads in relation to the total astragalar height. The sivatheres and the okapi share a reduced notch on the lateral edge of the astragalus. We find that Samotherium is more primitive in astragalar morphologies than Palaeotragus, which is reinforced by tooth characteristics and ossicone position. Diagnostic anatomical characters on the astragalus allow for giraffid species identifications and a better understanding of Giraffidae. PMID:27028515

Prediction of Erectile Function Following Treatment for Prostate Cancer

PubMed Central

Alemozaffar, Mehrdad; Regan, Meredith M.; Cooperberg, Matthew R.; Wei, John T.; Michalski, Jeff M.; Sandler, Howard M.; Hembroff, Larry; Sadetsky, Natalia; Saigal, Christopher S.; Litwin, Mark S.; Klein, Eric; Kibel, Adam S.; Hamstra, Daniel A.; Pisters, Louis L.; Kuban, Deborah A.; Kaplan, Irving D.; Wood, David P.; Ciezki, Jay; Dunn, Rodney L.; Carroll, Peter R.; Sanda, Martin G.

2013-01-01

Context Sexual function is the health-related quality of life (HRQOL) domain most commonly impaired after prostate cancer treatment; however, validated tools to enable personalized prediction of erectile dysfunction after prostate cancer treatment are lacking. Objective To predict long-term erectile function following prostate cancer treatment based on individual patient and treatment characteristics. Design Pretreatment patient characteristics, sexual HRQOL, and treatment details measured in a longitudinal academic multicenter cohort (Prostate Cancer Outcomes and Satisfaction With Treatment Quality Assessment; enrolled from 2003 through 2006), were used to develop models predicting erectile function 2 years after treatment. A community-based cohort (community-based Cancer of the Prostate Strategic Urologic Research Endeavor [CaPSURE]; enrolled 1995 through 2007) externally validated model performance. Patients in US academic and community-based practices whose HRQOL was measured pretreatment (N = 1201) underwent follow-up after prostatectomy, external radiotherapy, or brachytherapy for prostate cancer. Sexual outcomes among men completing 2 years’ follow-up (n = 1027) were used to develop models predicting erectile function that were externally validated among 1913 patients in a community-based cohort. Main Outcome Measures Patient-reported functional erections suitable for intercourse 2 years following prostate cancer treatment. Results Two years after prostate cancer treatment, 368 (37% [95% CI, 34%–40%]) of all patients and 335 (48% [95% CI, 45%–52%]) of those with functional erections prior to treatment reported functional erections; 531 (53% [95% CI, 50%–56%]) of patients without penile prostheses reported use of medications or other devices for erectile dysfunction. Pretreatment sexual HRQOL score, age, serum prostate-specific antigen level, race/ethnicity, body mass index, and intended treatment details were associated with functional erections 2 years after treatment. Multivariable logistic regression models predicting erectile function estimated 2-year function probabilities from as low as 10% or less to as high as 70% or greater depending on the individual’s pretreatment patient characteristics and treatment details. The models performed well in predicting erections in external validation among CaPSURE cohort patients (areas under the receiver operating characteristic curve, 0.77 [95% CI, 0.74–0.80] for prostatectomy; 0.87 [95% CI, 0.80–0.94] for external radiotherapy; and 0.90 [95% CI, 0.85–0.95] for brachytherapy). Conclusion Stratification by pretreatment patient characteristics and treatment details enables prediction of erectile function 2 years after prostatectomy, external radiotherapy, or brachytherapy for prostate cancer. PMID:21934053

On the development of two characteristically different crystal morphology in SiO(2)-MgO-Al (2)O (3)-K (2)O-B (2)O (3)-F glass-ceramic system.

PubMed

Roy, Shibayan; Basu, Bikramjit

2009-01-01

The present work demonstrates how crystals with two different characteristic morphologies can be formed in SiO(2)-MgO-Al(2)O(3)-K(2)O-B(2)O(3)-F glass-ceramic system by adopting two sets of heat treatment experiments. In our study, single stage heat treatment experiments were performed at 1,000 degrees C for varying holding time of 8-24 h with 4 h time interval and as a function of temperature in the range of 1,000-1,120 degrees C with 40 degrees C temperature interval. The constant heating rate of 10 degrees C/min was employed for both sets of experiments. The microstructural changes were investigated using Fourier transformed infrared spectroscopy (FT-IR), SEM-EDS and XRD. For temperature variation batches, the microstructure is characterized by interlocked, randomly oriented mica plates ('house-of-cards' morphology). An important and new observation of complex crystal morphology is made in the samples heat treated at 1,000 degrees C for varying holding times. Such morphology appears to be the results of composite spherulitic-dendritic like growth of mica rods radiating from a central nucleus. The possible mechanism for such characteristic crystal growth morphology is discussed with reference to a nucleation-growth kinetics based model. The activation energy for crystal nucleation and Avrami index are computed to be 388 kJ/mol and 1.3 respectively, assuming Johnson-Mehl-Avrami model of crystallization. Another important result is that a maximum of around 70% of spherulitic-dendritic like crystal morphology can be obtained after heat treatment at 1,000 degrees C for 24 h, while a lower amount (approximately 58%) of interlocked plate like mica crystals is formed after heat treatment at 1,040 degrees C for 4 h.

Comparison of the sonographic features of the abdominal wall muscles and connective tissues in individuals with and without lumbopelvic pain.

PubMed

Whittaker, Jackie L; Warner, Martin B; Stokes, Maria

2013-01-01

Cross-sectional, case-control study. To measure and compare the resting thickness of the 4 abdominal wall muscles, their associated perimuscular connective tissue (PMCT), and interrecti distance (IRD) in persons with and without lumbopelvic pain (LPP), using ultrasound imaging. The muscles and PMCT of the abdominal wall assist in controlling the spine. Functional deficits of the abdominal wall muscles have been detected in populations with LPP. Investigations of the abdominal wall in those with LPP are primarily concerned with muscle, most commonly the transversus abdominis (TrA) and internal oblique (IO). Because the abdominal wall functions as a unit, all 4 abdominal muscles and their associated connective tissues should be considered concurrently. B-mode ultrasound imaging was used to measure the resting thickness of the rectus abdominis (RA), external oblique, IO, and TrA muscles; the PMCT planes; and IRD in 50 male and female subjects, 25 with and 25 without LPP (mean ± SD age, 36.3 ± 9.4 and 46.6 ± 8.0 years, respectively). Univariate correlation analysis was used to identify covariates. Analyses of covariance (ANCOVAs) and the Kruskal-Wallis test (IRD) were used to compare cohorts (α = .05). The LPP cohort had less total abdominal muscle thickness (LPP mean ± SD, 18.9 ± 3.0 mm; control, 20.3 ± 3.0 mm; ANCOVA adjusted for body mass index, P = .03), thicker PMCT (LPP, 5.5 ± 0.2 mm; control, 4.3 ± 0.2 mm; ANCOVA adjusted for body mass index, P = .007), and wider IRD (LPP, 11.5 ± 2.0 mm; control, 8.4 ± 1.8 mm; Kruskal-Wallis, P = .005). Analysis of individual muscle thickness revealed no difference in the external oblique, IO, and TrA, but a thinner RA in the LPP cohort (LPP mean ± SD, 7.8 ± 1.5 mm; control, 9.1 ± 1.2 mm; ANCOVA adjusted for body mass index, P<.001). To our knowledge, this is the first study to investigate the morphological characteristics of all 4 abdominal muscles and PMCT in individuals with LPP. The results suggest that there may be altered loading of the PMCT and linea alba secondary to an altered motor control strategy involving a reduced contribution of the RA. Further, the change in RA and connective tissue morphology may be more evident than changes in external oblique, IO, and TrA thickness in persons with LPP. The causes and functional implications of these changes warrant further investigation, as does the role of the RA muscle in the development and persistence of LPP.

Sound absorption and morphology characteristic of porous concrete paving blocks

NASA Astrophysics Data System (ADS)

Halim, N. H. Abd; Nor, H. Md; Ramadhansyah, P. J.; Mohamed, A.; Hassan, N. Abdul; Ibrahim, M. H. Wan; Ramli, N. I.; Nazri, F. Mohamed

2017-11-01

In this study, sound absorption and morphology characteristic of Porous Concrete Paving Blocks (PCPB) at different sizes of coarse aggregate were presented. Three different sizes of coarse aggregate were used; passing 10 mm retained 5 mm (as Control), passing 8 mm retained 5 mm (8 - 5) and passing 10 mm retained 8 mm (10 - 8). The sound absorption test was conducted through the impedance tube at different frequency. It was found that the size of coarse aggregate affects the level of absorption of the specimens. It also shows that PCPB 10 - 8 resulted in high sound absorption compared to the other blocks. On the other hand, microstructure morphology of PCPB shows a clearer version of existing micro-cracks and voids inside the specimens which affecting the results of sound absorption.

Systematic revision of the Taiwanese genus Kurixalus members with a description of two new endemic species (Anura, Rhacophoridae)

PubMed Central

Wu, Shu-Ping; Huang, Chuan-Chin; Tsai, Chi-Li; Lin, Te-En; Jhang, Jhih-Jia; Wu, Sheng-Hai

2016-01-01

Abstract Two new species of rhacophorid tree frog were identified in Taiwan. In both new taxa, derived reproductive characteristics of laying eggs in tree holes and oophagous tadpoles are shared with Kurixalus eiffingeri, but they are divergent from each other in molecular genetics, mating calls, and tadpole and adult morphology. The morphological characteristics and the molecular phylogenetic evidence support the hypothesis that the two new species, Kurixalus berylliniris sp. n. and Kurixalus wangi sp. n., are both monophyletic lineages. PMID:26877703

[Criteria for the determination of the distance of a gunshot from limited-range firearms based on the morphological characteristics of the wound and the results of inductively coupled plasma mass spectrometry].

PubMed

Svetlolobov, D Iu; Luzanova, I S; Demidov, I V; Zorin, Iu V; Sonis, M A; Likhachev, A S

2013-01-01

We have developed the criteria allowing to determine the distance of a gunshot from limited-range firearms (an IZh-79-9TGM pistol with the elastic bullet cartridges) based on the morphological characteristics of the wound and the results of inductively coupled plasma mass spectrometry. The method has been developed for the quantitative determination of barium, lead, and antimony in the targets depending on the gunshot distance.

Effect of hypoxia by intermittent altitude exposure on semen characteristics and testicular morphology of male rhesus monkeys

NASA Astrophysics Data System (ADS)

Saxena, D. K.

1995-09-01

Semen characteristics and testicular morphology of rhesus monkeys were studied on exposure to a simulated high altitude of 4411 m for 21 days. There was a partially reversible decrease in the semen volume, sperm count and sperm motility, as well as an elevation of pH and fructose concentration. These changes were associated with degeneration of the germinal epithelium and spermatogenic arrest at the end of third week of exposure which had not recovered even 3 weeks after the exposure.

Morphological and ecological preadaptations as the basis of bird synanthropization under transformed environment conditions

NASA Astrophysics Data System (ADS)

Rakhimov, I. I.; Ibragimova, K. K.

2018-01-01

Bird synanthropization is connected with a thorough and serious reconstruction of their biology and is a demonstration of changes currently occurring in the biosphere due to human influence. Nutritional and nesting conditions as well as protection due to urban characteristics are advantage factors that affect their populations. Under these conditions, the adaptive potential of species can be realized. Adaptations to a new and in-distinctive environment appear due to preadaptations. The synanthropization process of species happens without speciation by expression of existing genetic variation of morphological and ecological characteristics.

A developmental staging series for the African house snake, Boaedon (Lamprophis) fuliginosus.

PubMed

Boback, Scott M; Dichter, Eric K; Mistry, Hemlata L

2012-02-01

Embryonic staging series are important tools in the study of morphological evolution as they establish a common standard for future studies. In this study, we describe the in ovo embryological development of the African house snake (Boaedon fuliginosus), a non-venomous, egg-laying species within the superfamily Elapoidea. We develop our staging series based on external morphology of the embryo including the head, eye, facial prominences, pharyngeal slits, heart, scales, and endolymphatic ducts. An analysis of embryonic growth in length and mass is presented, as well as preliminary data on craniofacial skeletal development. Our results indicate that B. fuliginosus embryos are well into organogenesis but lack well-defined facial prominences at the time of oviposition. Mandibular and maxillary processes extend rostrally within 8 days (stage 3), corresponding to the first appearance of Meckel's cartilages. Overall, the development of the craniofacial skeleton in B. fuliginosus appears similar to that of other snake species with intramembraneous bones (e.g., dentary and compound bones) ossifying before most of the endochondral bones, the first of which to ossify are the quadrate and the otic capsule. Our staging series is the first to describe the post-ovipositional development of a non-venomous elapoid based on external morphology. This species is an extremely tractable captive that can produce large clutches of eggs every 45 days throughout the year. As such, B. fuliginosus should be a good model for evolutionary developmental biologists focusing on the craniofacial skeleton, loss of limbs, generational teeth, and venom delivery systems. Copyright © 2011 Elsevier GmbH. All rights reserved.

Cranial base morphology and temporal bone pneumatization in Asian Homo erectus.

PubMed

Balzeau, Antoine; Grimaud-Hervé, Dominique

2006-10-01

The external morphological features of the temporal bone are used frequently to determine taxonomic affinities of fossils of the genus Homo. Temporal bone pneumatization has been widely studied in great apes and in early hominids. However, this feature is rarely examined in the later hominids, particularly in Asian Homo erectus. We provide a comparative morphological and quantitative analysis of Asian Homo erectus from the sites of Ngandong, Sambungmacan, and Zhoukoudian, and of Neandertals and anatomically modern Homo sapiens in order to discuss causes and modalities of temporal bone pneumatization during hominid evolution. The evolution of temporal bone pneumatization in the genus Homo is more complex than previously described. Indeed, the Zhoukoudian fossils have a unique pattern of temporal bone pneumatization, whereas Ngandong and Sambungmacan fossils, as well as the Neandertals, more closely resemble the modern human pattern. Moreover, these Chinese fossils are characterized by a wide midvault and a relatively narrow occipital bone. Our results support the point of view that cell development does not play an active role in determining cranial base morphology. Instead, pneumatization is related to available space and to temporal bone morphology, and its development is related to correlated morphology and the relative disposition of the bones and cerebral lobes. Because variation in pneumatization is extensive within the same species, the phyletic implications of pneumatization are limited in the taxa considered here.

Morphology vs morphokinetics: a retrospective comparison of inter-observer and intra-observer agreement between embryologists on blastocysts with known implantation outcome.

PubMed

Adolfsson, Emma; Andershed, Anna Nowosad

2018-06-18

Our primary aim was to compare the morphology and morphokinetics on inter- and intra-observer agreement for blastocyst with known implantation outcome. Our secondary aim was to validate the morphokinetic parameters' ability to predict pregnancy using a previous published selection algorithm, and to compare this to standard morphology assessments. Two embryologists made independent blinded annotations on two occasions using time-lapse images and morphology evaluations using the Gardner Schoolcraft criteria of 99 blastocysts with known implantation outcome. Inter- and intra-observer agreement was calculated and compared using the two methods. The embryos were grouped based on their morphological score, and on their morphokinetic class using a previous published selection algorithm. The implantation rates for each group was calculated and compared. There was moderate agreement for morphology, with agreement on the same embryo score in 55 of 99 cases. The highest agreement rate was found for expansion grade, followed by trophectoderm and inner cell mass. Correlation with pregnancy was inconclusive. For morphokinetics, almost perfect agreement was found for early and late embryo development events, and strong agreement for day-2 and day-3 events. When applying the selection algorithm, the embryo distributions were uneven, and correlation to pregnancy was inconclusive. Time-lapse annotation is consistent and accurate, but our external validation of a previously published selection algorithm was unsuccessful.

Constraining Controls on the Emplacement of Long Lava Flows on Earth and Mars Through Modeling in ArcGIS

NASA Astrophysics Data System (ADS)

Golder, K.; Burr, D. M.; Tran, L.

2017-12-01

Regional volcanic processes shaped many planetary surfaces in the Solar System, often through the emplacement of long, voluminous lava flows. Terrestrial examples of this type of lava flow have been used as analogues for extensive martian flows, including those within the circum-Cerberus outflow channels. This analogy is based on similarities in morphology, extent, and inferred eruptive style between terrestrial and martian flows, which raises the question of how these lava flows appear comparable in size and morphology on different planets. The parameters that influence the areal extent of silicate lavas during emplacement may be categorized as either inherent or external to the lava. The inherent parameters include the lava yield strength, density, composition, water content, crystallinity, exsolved gas content, pressure, and temperature. Each inherent parameter affects the overall viscosity of the lava, and for this work can be considered a subset of the viscosity parameter. External parameters include the effusion rate, total erupted volume, regional slope, and gravity. To investigate which parameter(s) may control(s) the development of long lava flows on Mars, we are applying a computational numerical-modelling to reproduce the observed lava flow morphologies. Using a matrix of boundary conditions in the model enables us to investigate the possible range of emplacement conditions that can yield the observed morphologies. We have constructed the basic model framework in Model Builder within ArcMap, including all governing equations and parameters that we seek to test, and initial implementation and calibration has been performed. The base model is currently capable of generating a lava flow that propagates along a pathway governed by the local topography. At AGU, the results of model calibration using the Eldgá and Laki lava flows in Iceland will be presented, along with the application of the model to lava flows within the Cerberus plains on Mars. We then plan to convert the model into Python, for easy modification and portability within the community.

Extending Integrate-and-Fire Model Neurons to Account for the Effects of Weak Electric Fields and Input Filtering Mediated by the Dendrite.

PubMed

Aspart, Florian; Ladenbauer, Josef; Obermayer, Klaus

2016-11-01

Transcranial brain stimulation and evidence of ephaptic coupling have recently sparked strong interests in understanding the effects of weak electric fields on the dynamics of brain networks and of coupled populations of neurons. The collective dynamics of large neuronal populations can be efficiently studied using single-compartment (point) model neurons of the integrate-and-fire (IF) type as their elements. These models, however, lack the dendritic morphology required to biophysically describe the effect of an extracellular electric field on the neuronal membrane voltage. Here, we extend the IF point neuron models to accurately reflect morphology dependent electric field effects extracted from a canonical spatial "ball-and-stick" (BS) neuron model. Even in the absence of an extracellular field, neuronal morphology by itself strongly affects the cellular response properties. We, therefore, derive additional components for leaky and nonlinear IF neuron models to reproduce the subthreshold voltage and spiking dynamics of the BS model exposed to both fluctuating somatic and dendritic inputs and an extracellular electric field. We show that an oscillatory electric field causes spike rate resonance, or equivalently, pronounced spike to field coherence. Its resonance frequency depends on the location of the synaptic background inputs. For somatic inputs the resonance appears in the beta and gamma frequency range, whereas for distal dendritic inputs it is shifted to even higher frequencies. Irrespective of an external electric field, the presence of a dendritic cable attenuates the subthreshold response at the soma to slowly-varying somatic inputs while implementing a low-pass filter for distal dendritic inputs. Our point neuron model extension is straightforward to implement and is computationally much more efficient compared to the original BS model. It is well suited for studying the dynamics of large populations of neurons with heterogeneous dendritic morphology with (and without) the influence of weak external electric fields.

Extending Integrate-and-Fire Model Neurons to Account for the Effects of Weak Electric Fields and Input Filtering Mediated by the Dendrite

PubMed Central

Obermayer, Klaus

2016-01-01

Transcranial brain stimulation and evidence of ephaptic coupling have recently sparked strong interests in understanding the effects of weak electric fields on the dynamics of brain networks and of coupled populations of neurons. The collective dynamics of large neuronal populations can be efficiently studied using single-compartment (point) model neurons of the integrate-and-fire (IF) type as their elements. These models, however, lack the dendritic morphology required to biophysically describe the effect of an extracellular electric field on the neuronal membrane voltage. Here, we extend the IF point neuron models to accurately reflect morphology dependent electric field effects extracted from a canonical spatial “ball-and-stick” (BS) neuron model. Even in the absence of an extracellular field, neuronal morphology by itself strongly affects the cellular response properties. We, therefore, derive additional components for leaky and nonlinear IF neuron models to reproduce the subthreshold voltage and spiking dynamics of the BS model exposed to both fluctuating somatic and dendritic inputs and an extracellular electric field. We show that an oscillatory electric field causes spike rate resonance, or equivalently, pronounced spike to field coherence. Its resonance frequency depends on the location of the synaptic background inputs. For somatic inputs the resonance appears in the beta and gamma frequency range, whereas for distal dendritic inputs it is shifted to even higher frequencies. Irrespective of an external electric field, the presence of a dendritic cable attenuates the subthreshold response at the soma to slowly-varying somatic inputs while implementing a low-pass filter for distal dendritic inputs. Our point neuron model extension is straightforward to implement and is computationally much more efficient compared to the original BS model. It is well suited for studying the dynamics of large populations of neurons with heterogeneous dendritic morphology with (and without) the influence of weak external electric fields. PMID:27893786

Phylogenetic and functional implications of the ear region anatomy of Glossotherium robustum (Xenarthra, Mylodontidae) from the Late Pleistocene of Argentina

NASA Astrophysics Data System (ADS)

Boscaini, Alberto; Iurino, Dawid A.; Billet, Guillaume; Hautier, Lionel; Sardella, Raffaele; Tirao, German; Gaudin, Timothy J.; Pujos, François

2018-04-01

Several detailed studies of the external morphology of the ear region in extinct sloths have been published in the past few decades, and this anatomical region has proved extremely helpful in elucidating the phylogenetic relationships among the members of this mammalian clade. Few studies of the inner ear anatomy in these peculiar animals were conducted historically, but these are increasing in number in recent years, in both the extinct and extant representatives, due to wider access to CT-scanning facilities, which allow non-destructive access to internal morphologies. In the present study, we analyze the extinct ground sloth Glossotherium robustum and provide a description of the external features of the ear region and the endocranial side of the petrosal bone, coupled with the first data on the anatomy of the bony labyrinth. Some features observable in the ear region of G. robustum (e.g., the shape and size of the entotympanic bone and the morphology of the posteromedial surface of the petrosal) are highly variable, both intraspecifically and intraindividually. The form of the bony labyrinth of G. robustum is also described, providing the first data from this anatomical region for the family Mylodontidae. The anatomy of the bony labyrinth of the genus Glossotherium is here compared at the level of the superorder Xenarthra, including all available extant and extinct representatives, using geometric morphometric methods. In light of the new data, we discuss the evolution of inner ear anatomy in the xenarthran clade, and most particularly in sloths, considering the influence of phylogeny, allometry, and physiology on the shape of this highly informative region of the skull. These analyses show that the inner ear of Glossotherium more closely resembles that of the extant anteaters, and to a lesser extent those of the giant ground sloth Megatherium and euphractine armadillos, than those of the extant sloths Bradypus and Choloepus, further demonstrating the striking morphological convergence between the two extant sloth genera.

Molecular phylogeny and morphological revision of Myotis bats (Chiroptera: Vespertilionidae) from Taiwan and adjacent China.

PubMed

Ruedi, Manuel; Csorba, Gábor; Lin, Liang-Kong; Chou, Cheng-Han

2015-02-20

In taxonomic accounts, three species of Myotis have been traditionally reported to occur on the island of Taiwan: Watase's bat (M. formosus watasei Kishida), the Formosan broad-muzzled bat (M. muricola latirostris Kishida) and the Formosan mouse-eared bat (M. adversus taiwanensis Linde). The discovery in 1997 of an unknown taxon not fitting to the description of any of these species encouraged us to re-examine more thoroughly the systematics and phylogeny of Myotis bats inhabiting Taiwan. We used a combination of morphologic and molecular methods to aid the identification of the different taxa from this island and reconstruct their phylogenetic relationships. Multivariate analyses based on 17 craniodental characters of 105 specimens caught across Taiwan and further external characters allowed us to discriminate eight taxa of Myotinae co-occurring on this island. A subset of 80 specimens were further sequenced for the cytochrome b gene (1140 bp) and subjected to phylogenetic reconstructions including representative species from adjacent China and from all main lineages of the worldwide Myotis radiation. These molecular reconstructions showed that the Myotinae from Taiwan are phylogenetically diverse and are issued from several independent clades. The genetic results were completely congruent with the phenetic groupings based on craniodental and external morphology, as each of the eight Taiwanese taxa proved to be reciprocally monophyletic. Two unnamed taxa that did not fit into any of the known species were described as species new to science. Furthermore the taxon latirostris usually associated to the Asian M. muricola, was phylogenetically and morphologically distant from any other known Myotis and was assigned here to the fossil (Miocene) genus Submyotodon. Submyotodon latirostris, M. secundus sp. n. and M. soror sp. n. are endemic species from Taiwan, whereas the other five Myotis are more widespread and also found in the mainland. An identification key is provided to ease the discrimination of these Myotinae species in Taiwan and adjacent China.

Phylogenetic and functional implications of the ear region anatomy of Glossotherium robustum (Xenarthra, Mylodontidae) from the Late Pleistocene of Argentina.

PubMed

Boscaini, Alberto; Iurino, Dawid A; Billet, Guillaume; Hautier, Lionel; Sardella, Raffaele; Tirao, German; Gaudin, Timothy J; Pujos, François

2018-03-27

Several detailed studies of the external morphology of the ear region in extinct sloths have been published in the past few decades, and this anatomical region has proved extremely helpful in elucidating the phylogenetic relationships among the members of this mammalian clade. Few studies of the inner ear anatomy in these peculiar animals were conducted historically, but these are increasing in number in recent years, in both the extinct and extant representatives, due to wider access to CT-scanning facilities, which allow non-destructive access to internal morphologies. In the present study, we analyze the extinct ground sloth Glossotherium robustum and provide a description of the external features of the ear region and the endocranial side of the petrosal bone, coupled with the first data on the anatomy of the bony labyrinth. Some features observable in the ear region of G. robustum (e.g., the shape and size of the entotympanic bone and the morphology of the posteromedial surface of the petrosal) are highly variable, both intraspecifically and intraindividually. The form of the bony labyrinth of G. robustum is also described, providing the first data from this anatomical region for the family Mylodontidae. The anatomy of the bony labyrinth of the genus Glossotherium is here compared at the level of the superorder Xenarthra, including all available extant and extinct representatives, using geometric morphometric methods. In light of the new data, we discuss the evolution of inner ear anatomy in the xenarthran clade, and most particularly in sloths, considering the influence of phylogeny, allometry, and physiology on the shape of this highly informative region of the skull. These analyses show that the inner ear of Glossotherium more closely resembles that of the extant anteaters, and to a lesser extent those of the giant ground sloth Megatherium and euphractine armadillos, than those of the extant sloths Bradypus and Choloepus, further demonstrating the striking morphological convergence between the two extant sloth genera.

The artifcial catchment Chicken Creek as a tool to study initial ecosystem development

NASA Astrophysics Data System (ADS)

Schaaf, W.; Elmer, M.; Fischer, A.; Gerwin, W.; Nenov, R.

2011-12-01

The artificial catchment Chicken Creek was constructed in 2005 to study the increasingly complex interactions of processes and structures during initial development of ecosystems. The 6ha area serves as the central research site for the Transregional Collaborative Research Center 38. Both internal and external factors could be identified as driving forces for the formation of structures and patterns in the artificial catchment during the first five years of development. Initial structures formed by the construction process (e.g. catchment morphology, subsurface structures like clay dams and dumping cones, caterpillar tracks at the surface) and initial substrate characteristics (e.g. texture, geochemistry) were decisive both for the distribution and flow of precipitation water and for vegetation succession. External factors like episodic events (e.g. heavy thunderstorms) triggered erosion and dissection during this initial phase, promoted by the low vegetation cover and the unconsolidated sandy substrate. These processes resulted in transport and redistribution of water and sediment within the catchment, mainly along the main slope, and the formation of new structural elements like gullies and channels, a sedimentation fan above and sediments within the pond. As a result, we observed an overall differentiation of the site, e.g. with respect to water availability and texture redistribution, into areas with abrasion or accumulation processes dominating and areas with stable surfaces. During further development, both external factors and processes within the catchment continued to influence the site. For example, beside the initial soil seed bank, the surrounding environment of the catchment clearly affected species invasion. The dissection and stability of surfaces may be an important factor for the establishment of plants and habitats as well as for the formation of vegetation patterns and biological soil crusts. The transformation of the initial geo-system into areas with evolving terrestrial or aquatic characteristics and from a very episodic to a more permanent stream network and discharge, together with the observed vegetation dynamics increased site diversity and heterogeneity with respect to water and nutrient availability and transformation processes compared to the more homogenous conditions at point zero. We expect that these more permanent structures and patterns established after five years will greatly influence the future development of the catchment with respect to e.g. input and accumulation of soil organic matter, nitrogen input and availability by symbiotic microbial N-fixation, development of root systems and soil food webs, weathering and soil formation, element cycling, and the water and element budget at the catchment scale.

Convergence characteristics between a rodent, the South American lowland paca, and a ruminant, the African water chevrotain: An exemplary case study.

PubMed

Dubost, Gérard

2017-03-01

The level of convergence between a rodent, the South American lowland paca Cuniculus paca, and a ruminant, the African water chevrotain Hyemoschus aquaticus, is analysed using 231 characteristics belonging to different biological sectors. A convergence index is established based on the degree of rarity of each characteristic in each species compared to other members of its zoological group. Although the divergent characteristics are as numerous as the convergent ones, the two species are globally similar. Convergent characteristics occur in all biological categories, but their rate varies a great deal among them. From internal anatomy and osteology, through behaviour and ecology to the external appearance of the body, convergent characteristics are all the more frequent since the biological category is directly implicated in the adaptation of animals to their external environment (lowland rainforest). However, only the individuals' characteristics are concerned and not those of their population or social organisation. This could be due to differences between the communities of terrestrial mammals to which they belong. Copyright © 2017 Académie des sciences. Published by Elsevier Masson SAS. All rights reserved.

Linking fine root morphology, hydraulic functioning, and shade tolerance of trees

USDA-ARS?s Scientific Manuscript database

Understanding root traits and trade-offs in their functioning is important for understanding plant functioning in natural ecosystems as well as agricultural systems. The aim of the present study was to determine the relationship between root morphology and the hydraulic characteristics of fine roots...

Morphological and Biological alteration of maize root architectures on drought stress

USDA-ARS?s Scientific Manuscript database

Drought tolerance is a complex agronomic trait and root characteristics logically play an important role in determining the response of plants to drought stress. Studies were conducted to investigate genotypic variations in morphological and physiological responses of roots to drought stress in corn...

Morphological and biological alteration of maize root architectures on drought stress

USDA-ARS?s Scientific Manuscript database

Drought tolerance is a complex agronomic trait and root characteristics logically play an important role in determining the response of plants to drought stress. Studies were conducted to investigate genotypic variations in morphological and physiological responses of roots to drought stress in corn...

A molecular phylogeny for Cercocarpus H.B.K. (Rosaceae) using the external transcribed spacer of the nuclear ribosomal repeat

Treesearch

Brian D. Vanden Heuvel; C. Randal Linder

2001-01-01

Cercocarpus H.B.K. (Rosaceae) taxa are important members of the plant communities of the western states and Mexico, yet the systematics of this genus are unknown primarily from lack of clear morphological delimitations between taxa. In recent years, molecular data have proven useful for resolving relationships among species and the diversity within species that have...

Survival and failure modes: platform-switching for internal and external hexagon cemented fixed dental prostheses.

PubMed

Anchieta, Rodolfo B; Machado, Lucas S; Hirata, Ronaldo; Coelho, Paulo G; Bonfante, Estevam A

2016-10-01

This study evaluated the probability of survival (reliability) of platform-switched fixed dental prostheses (FDPs) cemented on different implant-abutment connection designs. Eighty-four-three-unit FDPs (molar pontic) were cemented on abutments connected to two implants of external or internal hexagon connection. Four groups (n = 21 each) were established: external hexagon connection and regular platform (ERC); external hexagon connection and switched platform (ESC); internal hexagon and regular platform (IRC); and internal hexagon and switched platform (ISC). Prostheses were subjected to step-stress accelerated life testing in water. Weibull curves and probability of survival for a mission of 100,000 cycles at 400 N (two-sided 90% CI) were calculated. The beta values of 0.22, 0.48, 0.50, and 1.25 for groups ERC, ESC, IRC, and ISC, respectively, indicated a limited role of fatigue in damage accumulation, except for group ISC. Survival decreased for both platform-switched groups (ESC: 74%, and ISC: 59%) compared with the regular matching platform counterparts (ERC: 95%, and IRC: 98%). Characteristic strength was higher only for ERC compared with ESC, but not different between internal connections. Failures chiefly involved the abutment screw. Platform switching decreased the probability of survival of FDPs on both external and internal connections. The absence in loss of characteristic strength observed in internal hexagon connections favor their use compared with platform-switched external hexagon connections. © 2016 Eur J Oral Sci.

Determination of channel-morphology characteristics, bankfull discharge, and various design-peak discharges in western Montana

USGS Publications Warehouse

Lawlor, Sean M.

2004-01-01

Stream-restoration projects using natural stream designs typically are based on channel configurations that can accommodate a wide range of streamflow and sediment-transport conditions without excessive erosion or deposition. Bankfull discharge is an index of streamflow considered to be closely related to channel shape, size, and slope (channel morphology). Because of the need for more information about the relation between channel morphology and bankfull discharge, the U.S. Geological Survey (USGS), in cooperation with the Montana Department of Transportation and the U.S. Department of Agriculture-Lolo National Forest, conducted a study to collect channel-morphology and bankfull-discharge data at gaged sites and use these data to improve current (2004) methods of estimation of bankfull discharge and various design-peak discharges at ungaged sites. This report presents channel-morphology characteristics, bankfull discharge, and various design-peak discharges for 41 sites in western Montana. Channel shape, size, and slope and bankfull discharge were determined at 41 active or discontinued USGS streamflow-gaging sites in western Montana. The recurrence interval for the bankfull discharge for this study ranged from 1.0 to 4.4 years with a median value of 1.5 years. The relations between channel-morphology characteristics and various design-peak discharges were examined using regression analysis. The analyses showed that the only characteristics that were significant for all peak discharges were either bankfull width or bankfull cross-sectional area. Bankfull discharge at ungaged sites in most of the study area can be estimated by application of a multiplier after determining the 2-year peak discharge at the ungaged site. The multiplier, which is the ratio of bankfull discharge to the 2-year peak discharge determined at the 41 sites, ranged from 0.21 to 3.7 with a median value of 0.84. Regression relations between bankfull discharge and drainage area and between bankfull width and drainage area were examined for three ranges of mean annual precipitation. The results of the regression analyses indicated that both drainage area and mean annual precipitation were significantly related (p values less than 0.05) to bankfull discharge.

A Nice Way To Make a Living: Reflections on the Career of an Experienced Theatre Teacher.

ERIC Educational Resources Information Center

Brown, Cynthia L.

1999-01-01

Presents a case study examining the personal characteristics and external support systems which may have led to longevity in the career of a specific high school theatre arts teacher. Discusses internal support systems (including organizational skills, being adaptable to change, and respecting students) and external support systems (including the…

[Physical, chemical and morphological urine examination guidelines for the Analytical Phase from the Intersociety Urinalysis Group].

PubMed

Manoni, Fabio; Gessoni, Gianluca; Fogazzi, Giovanni Battista; Alessio, Maria Grazia; Caleffi, Alberta; Gambaro, Giovanni; Epifani, Maria Grazia; Pieretti, Barbara; Perego, Angelo; Ottomano, Cosimo; Saccani, Graziella; Valverde, Sara; Secchiero, Sandra

2016-01-01

With these guidelines the Intersociety Urinalysis Group (GIAU) aims to stimulate the following aspects: Improvement and standardization of the analytical approach to physical, chemical and morphological urine examination (ECMU). Improvement of the chemical analysis of urine with particular regard to the reconsideration of the diagnostic significance of the parameters that are traditionally evaluated in dipstick analysis together with an increasing awareness of the limits of sensitivity and specificity of this analytical method. Increase the awareness of the importance of professional skills in the field of urinary morphology and the relationship with the clinicians. Implement a policy of evaluation of the analytical quality by using, in addition to traditional internal and external controls, a program for the evaluation of morphological competence. Stimulate the diagnostics industry to focus research efforts and development methodology and instrumental catering on the needs of clinical diagnosis. The hope is to revalue the enormous diagnostic potential of 'ECMU, implementing a urinalysis on personalized diagnostic needs for each patient. Emphasize the value added to ECMU by automated analyzers for the study of the morphology of the corpuscular fraction urine. The hope is to revalue the enormous potential diagnostic of 'ECMU, implementing a urinalysis on personalized diagnostic needs that each patient brings with it.

Distinct alterations in colonic morphology and physiology in two rat models of enhanced stress-induced anxiety and depression-like behaviour.

PubMed

O'Malley, Dervla; Julio-Pieper, Marcela; Gibney, Sinead M; Dinan, Timothy G; Cryan, John F

2010-03-01

Stress and anxiety are important causal and exacerbating factors in functional gastro-intestinal (GI) disorders such as irritable bowel syndrome. Stress affects GI motility, faecal transit and visceral pain sensitivity. Additionally, permeability and function of the gut epithelium, which acts as a barrier between the external environment and the body's internal milieu is altered by stress. However, the effects of an enhanced stress response on colonic morphology require further investigation. We have used two animal models of stress and anxiety, the maternally separated (MS) and Wistar Kyoto (WKY) rats to examine colonic morphology. These rats exhibit increased anxiety behaviours, visceral hypersensitivity and increased stress-induced defecation in the open field arena. At a morphological level, increased mucus secretion and an associated elevation in the number of mucosal goblet cells was observed in the high anxiety rats. Additionally, the mucosal layer was flattened in MS and WKY rats, a finding indicative of mild mucosal damage. Furthermore, the muscular layer of the distal colon in these animals was thickened, an observation that may have implications for faecal transit and visceral pain perception. This study provides evidence of altered colonic function and morphology in two animal models with a heightened response to stress.

Repeated Origin and Loss of Adhesive Toepads in Geckos

PubMed Central

Gamble, Tony; Greenbaum, Eli; Jackman, Todd R.; Russell, Anthony P.; Bauer, Aaron M.

2012-01-01

Geckos are well known for their extraordinary clinging abilities and many species easily scale vertical or even inverted surfaces. This ability is enabled by a complex digital adhesive mechanism (adhesive toepads) that employs van der Waals based adhesion, augmented by frictional forces. Numerous morphological traits and behaviors have evolved to facilitate deployment of the adhesive mechanism, maximize adhesive force and enable release from the substrate. The complex digital morphologies that result allow geckos to interact with their environment in a novel fashion quite differently from most other lizards. Details of toepad morphology suggest multiple gains and losses of the adhesive mechanism, but lack of a comprehensive phylogeny has hindered efforts to determine how frequently adhesive toepads have been gained and lost. Here we present a multigene phylogeny of geckos, including 107 of 118 recognized genera, and determine that adhesive toepads have been gained and lost multiple times, and remarkably, with approximately equal frequency. The most likely hypothesis suggests that adhesive toepads evolved 11 times and were lost nine times. The overall external morphology of the toepad is strikingly similar in many lineages in which it is independently derived, but lineage-specific differences are evident, particularly regarding internal anatomy, with unique morphological patterns defining each independent derivation. PMID:22761794

Influence of external magnetic field on laser-induced gold nanoparticles fragmentation

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

Serkov, A. A.; The Federal State Educational Institution of Higher Professional Education, “Moscow Institute of Physics and Technology; Rakov, I. I.

Laser-assisted fragmentation is an efficient method of the nanoparticles size and morphology control. However, its exact mechanisms are still under consideration. One of the remaining problems is the plasma formation, inevitably occurring upon the high intensity laser irradiation. In this Letter, the role of the laser-induced plasma is studied via introduction of high-intensity external magnetic field (up to 7.5 T). Its presence is found to cause the plasma emission to start earlier regarding to a laser pulse, also increasing the plume luminosity. Under these conditions, the acceleration of nanoparticles fragmentation down to a few nanometers is observed. Laser-induced plasma interaction withmore » magnetic field and consequent energy transfer from plasma to nanoparticles are discussed.« less

Sponge budding is a spatiotemporal morphological patterning process: Insights from synchrotron radiation-based x-ray microtomography into the asexual reproduction of Tethya wilhelma.

PubMed

Hammel, Jörg U; Herzen, Julia; Beckmann, Felix; Nickel, Michael

2009-09-08

Primary agametic-asexual reproduction mechanisms such as budding and fission are present in all non-bilaterian and many bilaterian animal taxa and are likely to be metazoan ground pattern characters. Cnidarians display highly organized and regulated budding processes. In contrast, budding in poriferans was thought to be less specific and related to the general ability of this group to reorganize their tissues. Here we test the hypothesis of morphological pattern formation during sponge budding. We investigated the budding process in Tethya wilhelma (Demospongiae) by applying 3D morphometrics to high resolution synchrotron radiation-based x-ray microtomography (SR-muCT) image data. We followed the morphogenesis of characteristic body structures and identified distinct morphological states which indeed reveal characteristic spatiotemporal morphological patterns in sponge bud development. We discovered the distribution of skeletal elements, canal system and sponge tissue to be based on a sequential series of distinct morphological states. Based on morphometric data we defined four typical bud stages. Once they have reached the final stage buds are released as fully functional juvenile sponges which are morphologically and functionally equivalent to adult specimens. Our results demonstrate that budding in demosponges is considerably more highly organized and regulated than previously assumed. Morphological pattern formation in asexual reproduction with underlying genetic regulation seems to have evolved early in metazoans and was likely part of the developmental program of the last common ancestor of all Metazoa (LCAM).

Sponge budding is a spatiotemporal morphological patterning process: Insights from synchrotron radiation-based x-ray microtomography into the asexual reproduction of Tethya wilhelma

PubMed Central

Hammel, Jörg U; Herzen, Julia; Beckmann, Felix; Nickel, Michael

2009-01-01

Background Primary agametic-asexual reproduction mechanisms such as budding and fission are present in all non-bilaterian and many bilaterian animal taxa and are likely to be metazoan ground pattern characters. Cnidarians display highly organized and regulated budding processes. In contrast, budding in poriferans was thought to be less specific and related to the general ability of this group to reorganize their tissues. Here we test the hypothesis of morphological pattern formation during sponge budding. Results We investigated the budding process in Tethya wilhelma (Demospongiae) by applying 3D morphometrics to high resolution synchrotron radiation-based x-ray microtomography (SR-μCT) image data. We followed the morphogenesis of characteristic body structures and identified distinct morphological states which indeed reveal characteristic spatiotemporal morphological patterns in sponge bud development. We discovered the distribution of skeletal elements, canal system and sponge tissue to be based on a sequential series of distinct morphological states. Based on morphometric data we defined four typical bud stages. Once they have reached the final stage buds are released as fully functional juvenile sponges which are morphologically and functionally equivalent to adult specimens. Conclusion Our results demonstrate that budding in demosponges is considerably more highly organized and regulated than previously assumed. Morphological pattern formation in asexual reproduction with underlying genetic regulation seems to have evolved early in metazoans and was likely part of the developmental program of the last common ancestor of all Metazoa (LCAM). PMID:19737392

Sociolinguistic Typology and Sign Languages

PubMed Central

Schembri, Adam; Fenlon, Jordan; Cormier, Kearsy; Johnston, Trevor

2018-01-01

This paper examines the possible relationship between proposed social determinants of morphological ‘complexity’ and how this contributes to linguistic diversity, specifically via the typological nature of the sign languages of deaf communities. We sketch how the notion of morphological complexity, as defined by Trudgill (2011), applies to sign languages. Using these criteria, sign languages appear to be languages with low to moderate levels of morphological complexity. This may partly reflect the influence of key social characteristics of communities on the typological nature of languages. Although many deaf communities are relatively small and may involve dense social networks (both social characteristics that Trudgill claimed may lend themselves to morphological ‘complexification’), the picture is complicated by the highly variable nature of the sign language acquisition for most deaf people, and the ongoing contact between native signers, hearing non-native signers, and those deaf individuals who only acquire sign languages in later childhood and early adulthood. These are all factors that may work against the emergence of morphological complexification. The relationship between linguistic typology and these key social factors may lead to a better understanding of the nature of sign language grammar. This perspective stands in contrast to other work where sign languages are sometimes presented as having complex morphology despite being young languages (e.g., Aronoff et al., 2005); in some descriptions, the social determinants of morphological complexity have not received much attention, nor has the notion of complexity itself been specifically explored. PMID:29515506

Free-space QKD system hacking by wavelength control using an external laser.

PubMed

Lee, Min Soo; Woo, Min Ki; Jung, Jisung; Kim, Yong-Su; Han, Sang-Wook; Moon, Sung

2017-05-15

We develop a way to hack free-space quantum key distribution (QKD) systems by changing the wavelength of the quantum signal laser using an external laser. Most free-space QKD systems use four distinct lasers for each polarization, thereby making the characteristics of each laser indistinguishable. We also discover a side-channel that can distinguish the lasers by using an external laser. Our hacking scheme identifies the lasers by automatically applying the external laser to each signal laser at different intensities and detecting the wavelength variation according to the amount of incident external laser power. We conduct a proof-of-principle experiment to verify the proposed hacking structure and confirm that the wavelength varies by several gigahertzes to several nanometers, depending on the intensity of the external laser. The risk of hacking is successfully proven through the experimental results. Methods for prevention are also suggested.

Effects of Magnetic Nanoparticles and External Magnetostatic Field on the Bulk Heterojunction Polymer Solar Cells

DOE PAGES

Wang, Kai; Yi, Chao; Liu, Chang; ...

2015-03-18

The price of energy to separate tightly bound electron-hole pair (or charge-transfer state) and extract freely movable charges from low-mobility materials represents fundamental losses for many low-cost photovoltaic devices. In bulk heterojunction (BHJ) polymer solar cells (PSCs), approximately 50% of the total efficiency lost among all energy loss pathways is due to the photogenerated charge carrier recombination within PSCs and low charge carrier mobility of disordered organic materials. To address these issues, we introduce magnetic nanoparticles (MNPs) and orientate these MNPS within BHJ composite by an external magnetostatic field. Over 50% enhanced efficiency was observed from BHJ PSCs incorporated withmore » MNPs and an external magnetostatic field alignment when compared to the control BHJ PSCs. The optimization of BHJ thin film morphology, suppression of charge carrier recombination, and enhancement in charge carrier collection result in a greatly increased short-circuit current density and fill factor, as a result, enhanced power conversion efficiency.« less