WorldWideScience

Sample records for volume shape variation

  1. The effects of posture and subject-to-subject variations on the position, shape and volume of abdominal and thoracic organs.

    Science.gov (United States)

    Beillas, Philippe; Lafon, Yoann; Smith, Francis W

    2009-11-01

    In this study, the thorax and the abdomen of nine subjects were imaged in four postures using a positional MRI scanner. The four postures were seated, standing, forward-flexed and supine. They were selected to represent car occupants, pedestrians, cyclists and a typical position for medical imaging, respectively. Geometrical models of key anatomical structures were registered from the imaging dataset using a custom registration toolbox. The analysis of the images and models allowed the quantification of the respective effects of posture and subject-to-subject variation on the position, shape and volume of the abdominal organs, skeletal components and thoracic cavity. In summary, except for the supine posture, the organ volumes and their positions in the spinal frame were mostly unaffected by the posture. The supine posture was associated with a motion of all solid organs of up to 39 mm (interpostural maximum for the liver, n=9), and a reduction of the thoracic cavity volume of up to 1300 cm3. Subject-to-subject variations were especially large for the volume of the spleen (variations between 120 and 400 cm3) and the position of the kidneys. As a result, subject-to-subject variations were larger than most postural effects. Other results include values of parameters that can help positioning human models such as positions, volumes and inertial properties of organs as well as skeletal parameters. Overall, this study suggests that subject-to-subject variations and the use of supine geometrical data can be problematic for finite element modeling of the abdomen for injury prediction.

  2. Transformation Volume Effects on Shape Memory Alloys

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    Anna Kosogor

    2013-07-01

    Full Text Available It is generally accepted that the martensitic transformations (MTs in the shape memory alloys (SMAs are mainly characterized by the shear deformation of the crystal lattice that arises in the course of MT, while a comparatively small volume change during MT is considered as the secondary effect, which can be disregarded when the basic characteristics of MTs and functional properties of SMAs are analyzed. This point of view is a subject to change nowadays due to the new experimental and theoretical findings. The present article elucidates (i the newly observed physical phenomena in different SMAs in their relation to the volume effect of MT; (ii the theoretical analysis of the aforementioned volume-related phenomena.

  3. Stereological estimation of particle shape and orientation from volume tensors.

    Science.gov (United States)

    Rafati, A H; Ziegel, J F; Nyengaard, J R; Jensen, E B Vedel

    2016-09-01

    In the present paper, we describe new robust methods of estimating cell shape and orientation in 3D from sections. The descriptors of 3D cell shape and orientation are based on volume tensors which are used to construct an ellipsoid, the Miles ellipsoid, approximating the average cell shape and orientation in 3D. The estimators of volume tensors are based on observations in several optical planes through sampled cells. This type of geometric sampling design is known as the optical rotator. The statistical behaviour of the estimator of the Miles ellipsoid is studied under a flexible model for 3D cell shape and orientation. In a simulation study, the lengths of the axes of the Miles ellipsoid can be estimated with coefficients of variation of about 2% if 100 cells are sampled. Finally, we illustrate the use of the developed methods in an example, involving neurons in the medial prefrontal cortex of rat. © 2016 The Authors Journal of Microscopy © 2016 Royal Microscopical Society.

  4. The genetics of canine skull shape variation.

    Science.gov (United States)

    Schoenebeck, Jeffrey J; Ostrander, Elaine A

    2013-02-01

    A dog's craniofacial diversity is the result of continual human intervention in natural selection, a process that began tens of thousands of years ago. To date, we know little of the genetic underpinnings and developmental mechanisms that make dog skulls so morphologically plastic. In this Perspectives, we discuss the origins of dog skull shapes in terms of history and biology and highlight recent advances in understanding the genetics of canine skull shapes. Of particular interest are those molecular genetic changes that are associated with the development of distinct breeds.

  5. The evolution of genital shape variation in female cetaceans.

    Science.gov (United States)

    Orbach, Dara N; Hedrick, Brandon; Würsig, Bernd; Mesnick, Sarah L; Brennan, Patricia L R

    2018-02-01

    Male genital diversification is likely the result of sexual selection. Female genital diversification may also result from sexual selection, although it is less well studied and understood. Female genitalia are complex among whales, dolphins, and porpoises, especially compared to other vertebrates. The evolutionary factors affecting the diversity of vaginal complexity could include ontogeny, allometry, phylogeny, sexual selection, and natural selection. We quantified shape variation in female genitalia using 2D geometric morphometric analysis, and validated the application of this method to study soft tissues. We explored patterns of variation in the shape of the cervix and vagina of 24 cetacean species (n = 61 specimens), and found that genital shape varies primarily in the relative vaginal length and overall aspect ratio of the reproductive tract. Extensive genital shape variation was partly explained by ontogenetic changes and evolutionary allometry among sexually mature cetaceans, whereas phylogenetic signal, relative testis size, and neonate size were not significantly associated with genital shape. Female genital shape is diverse and evolves rapidly even among closely related species, consistent with predictions of sexual selection models and with findings in invertebrate and vertebrate taxa. Future research exploring genital shape variation in 3D will offer new insights into evolutionary mechanisms because internal vaginal structures are variable and can form complex spirals. © 2017 The Author(s). Evolution © 2017 The Society for the Study of Evolution.

  6. Sparse decomposition and modeling of anatomical shape variation

    DEFF Research Database (Denmark)

    Sjöstrand, Karl; Rostrup, Egill; Ryberg, Charlotte

    2007-01-01

    of anatomical variation related to clinical outcome. In the present application, landmark-based shape data of the corpus callosum is analyzed in relation to age, gender, and clinical tests of walking speed and verbal fluency. To put the data-driven sparse principal component method into perspective, we consider...

  7. Sparse Decomposition and Modeling of Anatomical Shape Variation

    DEFF Research Database (Denmark)

    Sjöstrand, Karl; Rostrup, Egill; Ryberg, Charlotte

    2007-01-01

    of anatomical variation related to clinical outcome. In the present application, landmark-based shape data of the corpus callosum is analyzed in relation to age, gender, and clinical tests of walking speed and verbal fluency. To put the data-driven sparse principal component method into perspective, we consider...

  8. Wing shape variation associated with mimicry in butterflies.

    Science.gov (United States)

    Jones, Robert T; Le Poul, Yann; Whibley, Annabel C; Mérot, Claire; ffrench-Constant, Richard H; Joron, Mathieu

    2013-08-01

    Mimetic resemblance in unpalatable butterflies has been studied by evolutionary biologists for over a century, but has largely focused on the convergence in wing color patterns. In Heliconius numata, discrete color-pattern morphs closely resemble comimics in the distantly related genus Melinaea. We examine the possibility that the shape of the butterfly wing also shows adaptive convergence. First, simple measures of forewing dimensions were taken of individuals in a cross between H. numata morphs, and showed quantitative differences between two of the segregating morphs, f. elegans and f. silvana. Second, landmark-based geometric morphometric and elliptical Fourier outline analyses were used to more fully characterize these shape differences. Extension of these techniques to specimens from natural populations suggested that, although many of the coexisting morphs could not be discriminated by shape, the differences we identified between f. elegans and f. silvana hold in the wild. Interestingly, despite extensive overlap, the shape variation between these two morphs is paralleled in their respective Melinaea comimics. Our study therefore suggests that wing-shape variation is associated with mimetic resemblance, and raises the intriguing possibility that the supergene responsible for controlling the major switch in color pattern between morphs also contributes to wing shape differences in H. numata. © 2013 The Author(s). Evolution © 2013 The Society for the Study of Evolution.

  9. Muscle shape consistency and muscle volume prediction of thigh muscles.

    Science.gov (United States)

    Mersmann, F; Bohm, S; Schroll, A; Boeth, H; Duda, G; Arampatzis, A

    2015-04-01

    The present study investigated the applicability of a muscle volume prediction method using only the muscle length (L(M)), the maximum anatomical cross-sectional area (ACSA(max)), and a muscle-specific shape factor (p) on the quadriceps vastii. L(M), ACSA(max), muscle volume, and p were obtained from magnetic resonance images of the vastus intermedius (VI), lateralis (VL), and medialis (VM) of female (n = 20) and male (n = 17) volleyball athletes. The average p was used to predict muscle volumes (V(p)) using the equation V(p)  = p × ACSA(max)  × L(M). Although there were significant differences in the muscle dimensions between male and female athletes, p was similar and on average 0.582, 0.658, 0.543 for the VI, VL, and VM, respectively. The position of ACSA(max) showed low variability and was at 57%, 60%, and 81% of the thigh length for VI, VL, and VM. Further, there were no significant differences between measured and predicted muscle volumes with root mean square differences of 5-8%. These results suggest that the muscle shape of the quadriceps vastii is independent of muscle dimensions or sex and that the prediction method could be sensitive enough to detect changes in muscle volume related to degeneration, atrophy, or hypertrophy. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  10. Cranial shape variation in adult howler monkeys (Alouatta seniculus).

    Science.gov (United States)

    Fiorenza, Luca; Bruner, Emiliano

    2017-12-05

    Howler monkeys (genus Alouatta) display a distinctive cranial architecture characterized by airorhynchy (or retroflexion of the facial skeleton on the cranial base), a small braincase, and a posteriorly oriented foramen magnum. This configuration has been associated with distinct factors including a high folivory diet, locomotion, and the presence of a specialized vocal tract characterized by large hyoid bone. However, the morphological relationships between the facial and neurocranial blocks in Alouatta have been scarcely investigated. In this study we quantitatively analyzed the cranial shape variation in Alouatta seniculus, to evaluate possible influences and constraints in face and braincase associated with airorhynchy. We also considered the structural role of the pteric area within the cranial functional matrix. We applied landmark-based analysis and multivariate statistics to 31 adult crania, computing shape analyses based on 3D coordinates registration as well as the analysis of the Euclidean distance matrix to investigate patterns of intraspecific morphological variability. Our results suggest that allometry is the main source of variation involved in shaping cranial morphology in howlers, influencing the degree of facial proportions and braincase flattening, and generating the main sexual differences. Larger individuals are characterized by a higher degree of airorhynchy, neurocranial flattening, and expansion of the zygomatic arch. Allometric variations influence the skull as a whole, without distinct patterns for face and braincase, which behave as an integrated morphological unit. A preliminary survey on the pteric pattern suggests that the morphology of this area may be the result of variations in the vertical growth rates between face and braincase. Future studies should be dedicated to the ontogenetic series and focus on airorhynchy in terms of differential growth among distinct cranial districts. © 2017 Wiley Periodicals, Inc.

  11. Subcortical shape and volume abnormalities in an elderly HIV+ cohort

    Science.gov (United States)

    Wade, Benjamin S. C.; Valcour, Victor; Busovaca, Edgar; Esmaeili-Firidouni, Pardis; Joshi, Shantanu H.; Wang, Yalin; Thompson, Paul M.

    2015-03-01

    Over 50% of HIV+ individuals show significant impairment in psychomotor functioning, processing speed, working memory and attention [1, 2]. Patients receiving combination antiretroviral therapy may still have subcortical atrophy, but the profile of HIV-associated brain changes is poorly understood. With parametric surface-based shape analyses, we mapped the 3D profile of subcortical morphometry in 63 elderly HIV+ subjects (4 female; age=65.35 ± 2.21) and 31 uninfected elderly controls (2 female; age=64.68 ± 4.57) scanned with MRI as part of a San Francisco Bay Area study of elderly people with HIV. We also investigated whether morphometry was associated with nadir CD4+ (T-cell) counts, viral load and illness duration among HIV+ participants. FreeSurfer was used to segment the thalamus, caudate, putamen, pallidum, hippocampus, amygdala, accumbens, brainstem, callosum and ventricles from brain MRI scans. To study subcortical shape, we analyzed: (1) the Jacobian determinant (JD) indexed over structures' surface coordinates and (2) radial distances (RD) of structure surfaces from a medial curve. A JD less than 1 reflects regional tissue atrophy and greater than 1 reflects expansion. The volumes of several subcortical regions were found to be associated with HIV status. No regional volumes showed detectable associations with CD4 counts, viral load or illness duration. The shapes of numerous subcortical regions were significantly linked to HIV status, detectability of viral RNA and illness duration. Our results show subcortical brain differences in HIV+ subjects in both shape and volumetric domains.

  12. Genetics of body shape and armour variation in threespine sticklebacks.

    Science.gov (United States)

    Leinonen, T; Cano, J M; Merilä, J

    2011-01-01

    Patterns of genetic variation and covariation can influence the rate and direction of phenotypic evolution. We explored the possibility that the parallel morphological evolution seen in threespine stickleback (Gasterosteus aculeatus) populations colonizing freshwater environments is facilitated by patterns of genetic variation and covariation in the ancestral (marine) population. We estimated the genetic (G) and phenotypic (P) covariance matrices and directions of maximum additive genetic (g(max) ) and phenotypic (p(max) ) covariances of body shape and armour traits. Our results suggest a role for the ancestral G in explaining parallel morphological evolution in freshwater populations. We also found evidence of genetic constraints owing to the lack of variance in the ancestral G. Furthermore, strong genetic covariances and correlations among traits revealed that selective factors responsible for threespine stickleback body shape and armour divergence may be difficult to disentangle. The directions of g(max) and p(max) were correlated, but the correlations were not high enough to imply that phenotypic patterns of trait variation and covariation within populations are very informative of underlying genetic patterns. © 2010 The Authors. Journal of Evolutionary Biology © 2010 European Society For Evolutionary Biology.

  13. Quantifying variation in human scalp hair fiber shape and pigmentation.

    Science.gov (United States)

    Lasisi, Tina; Ito, Shosuke; Wakamatsu, Kazumasa; Shaw, Colin N

    2016-06-01

    This study aims to evaluate the use of quantitative methods of measuring variation in scalp hair fiber shape and pigmentation and carry out exploratory data analysis on a limited sample of individuals from diverse populations in order to inform future avenues of research for the evolution of modern human hair variation. Cross-sectional area and shape and average curvature of scalp hair fibers were quantified using ImageJ. Pigmentation was analyzed using chemical methods estimating total melanin content through spectrophotometric methods, and eumelanin and pheomelanin content through HLPC analysis of melanin-specific degradation products. The initial results reinforced findings from earlier, traditional studies. African and African Diaspora scalp hair was significantly curled, (East) Asian hair was significantly thick, and European hair was significantly lighter in color. However, pigmentation analyses revealed a high level of variability in the melanin content of non-European populations and analysis of curvature found a large range of variation in the average curvature of East African individuals. Overall, these results suggest the usefulness of chemical methods for the elucidation of nonperceptible differences in scalp hair color and highlight the need for improvements in our assessment and understanding of hair fiber curvature. Am J Phys Anthropol 160:341-352, 2016. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  14. The Changes in Pulse Pressure Variation or Stroke Volume Variation After a "Tidal Volume Challenge" Reliably Predict Fluid Responsiveness During Low Tidal Volume Ventilation.

    Science.gov (United States)

    Myatra, Sheila Nainan; Prabu, Natesh R; Divatia, Jigeeshu Vasishtha; Monnet, Xavier; Kulkarni, Atul Prabhakar; Teboul, Jean-Louis

    2017-03-01

    Stroke volume variation and pulse pressure variation do not reliably predict fluid responsiveness during low tidal volume ventilation. We hypothesized that with transient increase in tidal volume from 6 to 8 mL/kg predicted body weight, that is, "tidal volume challenge," the changes in pulse pressure variation and stroke volume variation will predict fluid responsiveness. Prospective, single-arm study. Medical-surgical ICU in a university hospital. Adult patients with acute circulatory failure, having continuous cardiac output monitoring, and receiving controlled low tidal volume ventilation. The pulse pressure variation, stroke volume variation, and cardiac index were recorded at tidal volume 6 mL/kg predicted body weight and 1 minute after the "tidal volume challenge." The tidal volume was reduced back to 6 mL/kg predicted body weight, and a fluid bolus was given to identify fluid responders (increase in cardiac index > 15%). The end-expiratory occlusion test was performed at tidal volumes 6 and 8 mL/kg predicted body weight and after reducing tidal volume back to 6 mL/kg predicted body weight. Thirty measurements were obtained in 20 patients. The absolute change in pulse pressure variation and stroke volume variation after increasing tidal volume from 6 to 8 mL/kg predicted body weight predicted fluid responsiveness with areas under the receiver operating characteristic curves (with 95% CIs) being 0.99 (0.98-1.00) and 0.97 (0.92-1.00), respectively. The best cutoff values of the absolute change in pulse pressure variation and stroke volume variation after increasing tidal volume from 6 to 8 mL/kg predicted body weight were 3.5% and 2.5%, respectively. The pulse pressure variation, stroke volume variation, central venous pressure, and end-expiratory occlusion test obtained during tidal volume 6 mL/kg predicted body weight did not predict fluid responsiveness. The changes in pulse pressure variation or stroke volume variation obtained by

  15. Signals from the brain induce variation in avian facial shape.

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    Hu, Diane; Young, Nathan M; Xu, Qiuping; Jamniczky, Heather; Green, Rebecca M; Mio, Washington; Marcucio, Ralph S; Hallgrimsson, Benedikt

    2015-04-22

    How developmental mechanisms generate the phenotypic variation that is the raw material for evolution is largely unknown. Here, we explore whether variation in a conserved signaling axis between the brain and face contributes to differences in morphogenesis of the avian upper jaw. In amniotes, including both mice and avians, signals from the brain establish a signaling center in the ectoderm (the Frontonasal ectodermal zone or "FEZ") that directs outgrowth of the facial primordia. Here we show that the spatial organization of this signaling center differs among avians, and these correspond to Sonic hedgehog (Shh) expression in the basal forebrain and embryonic facial shape. In ducks this basal forebrain domain is present almost the entire width, while in chickens it is restricted to the midline. When the duck forebrain is unilaterally transplanted into stage matched chicken embryos the face on the treated side resembles that of the donor. Combined with previous findings, these results demonstrate that variation in a highly conserved developmental pathway has the potential to contribute to evolutionary differences in avian upper jaw morphology. Developmental Dynamics, 2015. © 2015 Wiley Periodicals, Inc. © 2015 Wiley Periodicals, Inc.

  16. Feeding variations and shape changes of a temperate reef clingfish during its early ontogeny

    Directory of Open Access Journals (Sweden)

    Valentina Bernal-Durán

    2017-06-01

    Full Text Available The majority of rocky reef fishes have complex life cycles, involving transition from a pelagic to a benthic environment. This means that as they grow, their morphology, behaviour and feeding habits must change. Therefore, shape changes occurring during early development of these fishes will be related to diet changes. The clingfish Sicyases sanguineus was selected for this study, because it displays a noticeable variation in shape from pelagic larvae to juvenile stage, and it is expected that diet composition will change as well. The pattern of shape changes was studied using geometric morphometrics. A set of 9 landmarks were digitized in 159 larval and juvenile fish and the same specimens were used for gut content analysis. Allometric growth was most prominent early in the ontogeny, from 4 to 12 mm. Morphology changed from a thin and hydrodynamic shape to a more robust and deeper body prior to settlement. The diet of the clingfish during larval stages showed preferences for a variety of copepod stages. As individual grows the ingested prey volume increases, but not the number and width of prey. A partial least square analysis showed low covariance between shape changes and diet composition changes in prey number and volume, suggesting that the two processes were temporally decoupled. The biggest shape changes, a lengthening of the visceral cavity and a flattening of the head, occurred up to 12 mm standard length, while the largest feeding differentiation, shifting from copepods to microalgae, occurred after 16 mm. Results suggest that shape changes precede trophic changes in this clingfish species during the transition from a pelagic to a benthic habitat.

  17. Alignment processes and shape variations in sup 184 Pt

    Energy Technology Data Exchange (ETDEWEB)

    Carpenter, M.P.; Bingham, C.R.; Courtney, L.H.; Janzen, V.P.; Larabee, A.J.; Liu, Z.M.; Riedinger, L.L.; Schmitz, W. (Tennessee Univ., Knoxville (USA). Dept. of Physics); Bengtsson, R.; Bengtsson, T.; Nazarewicz, W.; Zhang, J.Y. (Joint Inst. for Heavy Ion Research, Oak Ridge, TN (USA)); Johansson, J.K.; Popescu, D.G.; Waddington, J.C. (McMaster Univ., Hamilton, Ontario (Canada)); Baktash, C.; Halbert, M.L.; Johnson, N.R.; Lee, I.Y.; Schutz, Y.S. (Oak Ridge National Lab., TN (USA). Holifield Heavy Ion Research Facility); Nyberg, J.; Johnson, A.; Wyss, R. (Manne Siegbahn Inst. of Physics, Stockholm (Sweden) Royal Inst. of Tech., Stockholm (Sweden). Physics Dept. 1); Dubuc, J.; Kajrys, G.; Monaro, S.; Pilotte, S. (Montreal Univ., Quebec (Canada)); Honkanen, K.; Sarantites, D.G. (Washington Univ., St. Louis, MO (USA)); Haenni, D.R. (Texas A and M Univ., College Station (USA). Cyclotron Inst.)

    1990-06-25

    High-spin states in the transitional nucleus {sup 184}Pt were populated via the reactions {sup 154}Sm({sup 34}S, 4n){sup 184}Pt and {sup 172}Yb({sup 16}O, 4n){sup 184}Pt. The yrast band was extended up to I=28 {Dirac h} and six new side bands built on both neutron and proton quasiparticle configurations were observed. Shell correction-type calculations indicate variations of the nuclear shape in different bands, especially as a result of band crossings due to the process of angular momentum alignment. Comparison of the band characteristics are made between {sup 184}Pt and eight adjacent nuclei. The pattern of band crossings in these nine nuclei is considered from the viewpoint of blocking comparisons and of theoretical calculations. The competition between low-frequency {nu}i{sub 13/2} and {pi}h{sub 9/2} band crossings is discussed. (orig.).

  18. Head shape variation in eastern and western Montpellier snakes

    Directory of Open Access Journals (Sweden)

    Marco Mangiacotti

    2014-12-01

    Full Text Available The Montpellier snake Malpolon monspessulanus is a wide-ranging species that inhabits Western and Eastern Europe, North Africa and Middle East. Four clades have been recognised as two species, M. insignitus and M. monspessulanus, each with two subspecies. Clades have been substantially identified on the basis of molecular data, pholidosis and colouration, while morphometric traits have been ignored. We compared head shape of 54 specimens belonging to three out of the four clades (M. insignitus insignitus, M. i. fuscus, and M. monspessulanus monspessulanus by means of geometric morphometrics. We found a significant differentiation: the supraocular and frontal area showed the largest amount of variation, being respectively much thinner in M. i. insignitus, a bit less thin in M. i. fuscus and definitely wider in M. m. monspessulanus. Our findings are fully in agreement with the genetic studies and phylogeny explains more than 20% of the observed variation, supporting the taxonomic distinction inside the genus Malpolon. The functional and/or adaptive meaning of the observed differences is not clear, but it seems unlikely that it may be related to diet. Combining morphological data with phylogeography and environmental features, we formulated an explanatory hypothesis that allowed a precise and testable prediction.

  19. Stroke volume variations : Mild exercise and cardiovascular variability

    OpenAIRE

    Elstad, Maja

    2009-01-01

    Variations in left ventricular stroke volume (SV) is an important cardiovascular variable seldom investigated. This thesis in cardiovascular physiology studied the variations in SV in healthy, young volunteers. The focus was the role of SV variations in short-term regulation of the circulation. The circulatory changes that occur during mild exercise were investigated as were the spontaneous cardiovascular oscillations. The main protocols were experimental studies on humans, and a mathematical...

  20. Statistical shape modeling based renal volume measurement using tracked ultrasound

    Science.gov (United States)

    Pai Raikar, Vipul; Kwartowitz, David M.

    2017-03-01

    Autosomal dominant polycystic kidney disease (ADPKD) is the fourth most common cause of kidney transplant worldwide accounting for 7-10% of all cases. Although ADPKD usually progresses over many decades, accurate risk prediction is an important task.1 Identifying patients with progressive disease is vital to providing new treatments being developed and enable them to enter clinical trials for new therapy. Among other factors, total kidney volume (TKV) is a major biomarker predicting the progression of ADPKD. Consortium for Radiologic Imaging Studies in Polycystic Kidney Disease (CRISP)2 have shown that TKV is an early, and accurate measure of cystic burden and likely growth rate. It is strongly associated with loss of renal function.3 While ultrasound (US) has proven as an excellent tool for diagnosing the disease; monitoring short-term changes using ultrasound has been shown to not be accurate. This is attributed to high operator variability and reproducibility as compared to tomographic modalities such as CT and MR (Gold standard). Ultrasound has emerged as one of the standout modality for intra-procedural imaging and with methods for spatial localization has afforded us the ability to track 2D ultrasound in physical space which it is being used. In addition to this, the vast amount of recorded tomographic data can be used to generate statistical shape models that allow us to extract clinical value from archived image sets. In this work, we aim at improving the prognostic value of US in managing ADPKD by assessing the accuracy of using statistical shape model augmented US data, to predict TKV, with the end goal of monitoring short-term changes.

  1. Volume Sculpting: Intuitive, Interactive 3D Shape Modelling

    DEFF Research Database (Denmark)

    Bærentzen, Jakob Andreas

    A system for interactive modelling of 3D shapes on a computer is presented. The system is intuitive and has a flat learning curve. It is especially well suited to the creation of organic shapes and shapes of complex topology. The interaction is simple; the user can either add new shape features...

  2. Numerical Study of Variation of Mechanical Properties of a Binary Aluminum Alloy with Respect to Its Grain Shapes

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    Hamid Sharifi

    2014-04-01

    Full Text Available To study the variation of the mechanical behavior of binary aluminum copper alloys with respect to their microstructure, a numerical simulation of their granular structure was carried out. The microstructures are created by a repeated inclusion of some predefined basic grain shapes into a representative volume element until reaching a given volume percentage of the α-phase. Depending on the grain orientations, the coalescence of the grains can be performed. Different granular microstructures are created by using different basic grain shapes. Selecting a suitable set of basic grain shapes, the modeled microstructure exhibits a realistic aluminum alloy microstructure which can be adapted to a particular cooling condition. Our granular models are automatically converted to a finite element model. The effect of grain shapes and sizes on the variation of elastic modulus and plasticity of such a heterogeneous domain was investigated. Our results show that for a given α-phase fraction having different grain shapes and sizes, the elastic moduli and yield stresses are almost the same but the ultimate stress and elongation are more affected. Besides, we realized that the distribution of the θ phases inside the α phases is more important than the grain shape itself.

  3. Biannual Cycles in Intertidal Beach Volume Variations in New Zealand

    Science.gov (United States)

    Bryan, K. R.; Blossier, B.; Coco, G.

    2016-02-01

    Interannual beach variations in intertidal beach volumes have been shown to correlate with climatic drivers. In New Zealand, the main climatic drivers on the north east coast are the Pacific Decadal Oscillation (PDO) and the Southern Oscillation Index (SOI), which drive temperature and wind variations in the south Pacific. Lomb-scargle spectra of in situ intertidal beach volume measurements collected at 19 north-east beach sites and indices representing these two climate drivers show significant energy at biannual frequencies, yet no variation in wave climate at the same biannual timescale. In addition, the resolution of volume data precludes a detailed cross-correlation analysis. To explore the source of this biannual variation, a wave hindcast and an existing shoreline change model calibrated with 6 years of video-derived shoreline variations on one of the beaches was used to hindcast shoreline variations over (1) the time range of the in situ measurements ( 17 years) and (2) over the time range of the hindcast ( 33 years). Results show that the size of annual variations in the shoreline depend on the mean summer wave energy relative to the winter, which is inversely correlated with the energy difference the previous year (p=0.95). Moreover, the summer mean southern oscillation index had a similar inverse behaviour (p=0.90), and the two patterns are cross-correlated (p=0.95). Cross-correlation of the Pacific decadal oscillation index does not have the same pattern, likely due to the confounding effect of longer-term cycles in this index. Finally, results are not significant for the longer time range indicating that the biannual cycle is transient. Results show that very subtle variation in between the winter and summer wave climate can drive significant shoreline variations.

  4. Interspecific variation of ontogeny and skull shape among porpoises (Phocoenidae)

    DEFF Research Database (Denmark)

    Galatius, Anders; Berta, Annalisa; Frandsen, Marie Schou

    2011-01-01

    . dioptrica, for which large series were available, were further compared in terms of ontogeny of cranial shape by three-dimensional geometric morphometrics. Ph. dalli and P. dioptrica generally showed further development of cranial sutures than the other species. Postnatal skull shape development was similar...... for all species studied; the majority of interspecific shape differences are present at parturition. Smaller species had a higher rate of shape development relative to growth in size than Ph. dalli and P. dioptrica, but they still showed less allometric development due to less postnatal growth....... Interspecific shape differences indicate phylogenetic relationships similar to that proposed based on morphology or convergent evolution of the two pelagic species, Ph. dalli and P. dioptrica, under the scenarios suggested by recent molecular studies. A shape trend coinciding with habitat preference...

  5. Volume variation of Gruneisen parameters of fcc transition metals

    Indian Academy of Sciences (India)

    Unknown

    The results are reasonably good for six metals except for Rh, Ag, Au and Ni when compared with available experimental and other theoretical values. The model requires an appropriate modification for Rh, Ag, Au and Ni. Keywords. fcc transition metals; pseudopotential; Gruneisen parameter; volume variation of Gruneisen.

  6. Genomic regions controlling shape variation in the first upper molar of the house mouse.

    Science.gov (United States)

    Pallares, Luisa F; Ledevin, Ronan; Pantalacci, Sophie; Turner, Leslie M; Steingrimsson, Eirikur; Renaud, Sabrina

    2017-11-01

    Numerous loci of large effect have been shown to underlie phenotypic variation between species. However, loci with subtle effects are presumably more frequently involved in microevolutionary processes, but have rarely been discovered. We explore the genetic basis of shape variation in the first upper molar of hybrid mice between Mus musculus musculus and M. m. domesticus. We performed the first genome-wide association study for molar shape and used 3D surface morphometrics to quantify subtle variation between individuals. We show that many loci of small effect underlie phenotypic variation, and identify five genomic regions associated with tooth shape; one region contained the microphthalmia-associated transcription factor Mitf gene that has previously been associated with tooth malformations. Using a panel of five mutant laboratory strains, we show the effect of the Mitf gene on tooth shape. This is the first report of a gene causing subtle but consistent variation in tooth shape resembling variation in nature.

  7. Size and shape variation in the proximal femur of Australopithecus africanus.

    Science.gov (United States)

    Harmon, Elizabeth

    2009-06-01

    Aside from use as estimates of body mass dimorphism and fore to hind limb joint size comparisons, postcranial elements have not often contributed to assessments of variation in Australopithecus africanus. Meanwhile, cranial, facial, and dental size variation is interpreted to be high or moderately high. Further, the cranial base and face express patterns of structural (shape) variation, which are interpreted by some as evidence for the presence of multiple species. Here, the proximal femur is used to consider postcranial size and shape variation in A. africanus. Original fossils from Makapansgat and Sterkfontein, and samples from Homo, Pan, Gorilla, and Pongo were measured. Size variation was assessed by comparing the A. africanus coefficient of variation to bootstrapped distributions of coefficient of variation samples for each taxon. Shape variation was assessed from isometrically adjusted shape variables. First, the A. africanus standard deviation of log transformed shape variables was compared to bootstrapped distributions of logged standard deviations in each taxon. Second, shape variable based Euclidean distances between fossil pairs were compared to pairwise Euclidean distance distributions in each reference taxon. The degree of size variation in the A. africanus proximal femur is consistent with that of a single species, and is most comparable to Homo and Pan, lower than A. afarensis, and lower than some estimates of cranial and dental variation. Some, but not all, shape variables show more variation in A. africanus than in extant taxa. The degree of shape difference between some fossils exceeds the majority of pairwise differences in the reference taxa. Proximal femoral shape, but not size, variation is consistent with high estimates of A. africanus cranial variation.

  8. Interspecific variation of ontogeny and skull shape among porpoises (Phocoenidae).

    Science.gov (United States)

    Galatius, Anders; Berta, Annalisa; Frandsen, Marie Schou; Goodall, R Natalie P

    2011-02-01

    All extant members of Phocoenidae (porpoises) have been characterized as pedomorphic based on skeletal characters. To investigate the ontogenetic background for pedomorphosis and assess interspecific differences in ontogeny among phocoenids, samples of the six extant species were compared in terms of development of both epiphyseal and cranial suture fusion. Across all species, full maturity of the vertebral column was rare. Vertebral epiphyseal development did not progress so far in most Phocoena phocoena as in Phocoenoides dalli and Phocoena dioptrica. P. phocoena, Phocoena spinipinnis, Ph. dalli, and P. dioptrica, for which large series were available, were further compared in terms of ontogeny of cranial shape by three-dimensional geometric morphometrics. Ph. dalli and P. dioptrica generally showed further development of cranial sutures than the other species. Postnatal skull shape development was similar for all species studied; the majority of interspecific shape differences are present at parturition. Smaller species had a higher rate of shape development relative to growth in size than Ph. dalli and P. dioptrica, but they still showed less allometric development due to less postnatal growth. Interspecific shape differences indicate phylogenetic relationships similar to that proposed based on morphology or convergent evolution of the two pelagic species, Ph. dalli and P. dioptrica, under the scenarios suggested by recent molecular studies. A shape trend coinciding with habitat preference was detected; in species with pelagic preference the position and orientation of the foramen magnum aligned the skull with the vertebral column; the rostrum showed less ventral inclination, and the facial region was larger and more concave in lateral aspect. Copyright © 2010 Wiley-Liss, Inc.

  9. Global variation in woodpecker species richness shaped by tree availability

    DEFF Research Database (Denmark)

    Ilsoe, Sigrid Kistrup; Kissling, W. Daniel; Fjeldsa, Jon

    2017-01-01

    diversity when humans reduce tree availability. Hence, woodpeckers exemplify how broad-scale diversity patterns are predominantly shaped by a biotic factor, and how climate and human influence can have indirect effects on animal biodiversity via the effects on tree availability and forest cover....

  10. Affine transformations capture beak shape variation in Darwin's Finches

    Science.gov (United States)

    Brenner, Michael; Campas, Otger; Mallarino, Riccardo; Abzhanov, Arhat

    2009-11-01

    Evolution by natural selection has resulted in extraordinary morphological complexity of living organisms, whose description has thus far defied any precise mathematical characterization linked to the underlying developmental genetics. Here we demonstrate that the morphological diversity of the beaks of Darwin's finches, the classical example of adaptive morphological radiation, is quantitatively accounted for through the mathematical group of affine transformations. Specifically, we show that all beak shapes of Ground Finches (genus Geospiza) are related by scaling transformations (a subgroup of the affine group), and the same scheme occurs for all the beak shapes of Tree and Warbler finches. This analysis shows that the beak shapes within each of these groups differ only by their scales, such as length and depth, each of which is knownto be under genetic control.The complete morphological variability within the beaks of Darwin's finches can be explained by extending the scaling transformations to the entire affine group, by including shear transformations. Altogether our results suggest that the mathematical theory of groups can help decode morphological variability, and points to a potentially hierarchical structure of morphological diversity and the underlying developmental processes.

  11. variations in dimensions and shape of thoracic cage with aging

    African Journals Online (AJOL)

    ABSTRACT. The thoracic cage variations in dimensions and proportions are influenced by age, sex and race. The objective of the present review was to describe the age related changes occurring in thoracic wall and its influence on the pattern of respiration in infants, adult and elderly. We had systematically reviewed, ...

  12. Intraspecific variation in wing shape of Poecilobothrus regalis (Meigen, 1824 (Diptera, Dolichopodidae

    Directory of Open Access Journals (Sweden)

    Mariya A. Chursina

    2016-08-01

    Full Text Available A study of 186 specimens of Poecilobothrus regalis was conducted in order to examine intraspecific variability of wing shape. The wing shape variation was analyzed using geometric morphometrics analyses. Significant differences in the structure of wing were found both between sexes and between populations. Differences between sexes were observed in the structure of the medium portion of wing. The first extracted canonical variate of geographic variation showed a moderately linear association with latitude and average temperature of February and March. The second canonical variate was correlated with longitude and values of average wind flow velocity. Allometric relationships were weak both between populations and sexes.

  13. The African Genome Variation Project shapes medical genetics in Africa.

    Science.gov (United States)

    Gurdasani, Deepti; Carstensen, Tommy; Tekola-Ayele, Fasil; Pagani, Luca; Tachmazidou, Ioanna; Hatzikotoulas, Konstantinos; Karthikeyan, Savita; Iles, Louise; Pollard, Martin O; Choudhury, Ananyo; Ritchie, Graham R S; Xue, Yali; Asimit, Jennifer; Nsubuga, Rebecca N; Young, Elizabeth H; Pomilla, Cristina; Kivinen, Katja; Rockett, Kirk; Kamali, Anatoli; Doumatey, Ayo P; Asiki, Gershim; Seeley, Janet; Sisay-Joof, Fatoumatta; Jallow, Muminatou; Tollman, Stephen; Mekonnen, Ephrem; Ekong, Rosemary; Oljira, Tamiru; Bradman, Neil; Bojang, Kalifa; Ramsay, Michele; Adeyemo, Adebowale; Bekele, Endashaw; Motala, Ayesha; Norris, Shane A; Pirie, Fraser; Kaleebu, Pontiano; Kwiatkowski, Dominic; Tyler-Smith, Chris; Rotimi, Charles; Zeggini, Eleftheria; Sandhu, Manjinder S

    2015-01-15

    Given the importance of Africa to studies of human origins and disease susceptibility, detailed characterization of African genetic diversity is needed. The African Genome Variation Project provides a resource with which to design, implement and interpret genomic studies in sub-Saharan Africa and worldwide. The African Genome Variation Project represents dense genotypes from 1,481 individuals and whole-genome sequences from 320 individuals across sub-Saharan Africa. Using this resource, we find novel evidence of complex, regionally distinct hunter-gatherer and Eurasian admixture across sub-Saharan Africa. We identify new loci under selection, including loci related to malaria susceptibility and hypertension. We show that modern imputation panels (sets of reference genotypes from which unobserved or missing genotypes in study sets can be inferred) can identify association signals at highly differentiated loci across populations in sub-Saharan Africa. Using whole-genome sequencing, we demonstrate further improvements in imputation accuracy, strengthening the case for large-scale sequencing efforts of diverse African haplotypes. Finally, we present an efficient genotype array design capturing common genetic variation in Africa.

  14. The African Genome Variation Project shapes medical genetics in Africa

    Science.gov (United States)

    Gurdasani, Deepti; Carstensen, Tommy; Tekola-Ayele, Fasil; Pagani, Luca; Tachmazidou, Ioanna; Hatzikotoulas, Konstantinos; Karthikeyan, Savita; Iles, Louise; Pollard, Martin O.; Choudhury, Ananyo; Ritchie, Graham R. S.; Xue, Yali; Asimit, Jennifer; Nsubuga, Rebecca N.; Young, Elizabeth H.; Pomilla, Cristina; Kivinen, Katja; Rockett, Kirk; Kamali, Anatoli; Doumatey, Ayo P.; Asiki, Gershim; Seeley, Janet; Sisay-Joof, Fatoumatta; Jallow, Muminatou; Tollman, Stephen; Mekonnen, Ephrem; Ekong, Rosemary; Oljira, Tamiru; Bradman, Neil; Bojang, Kalifa; Ramsay, Michele; Adeyemo, Adebowale; Bekele, Endashaw; Motala, Ayesha; Norris, Shane A.; Pirie, Fraser; Kaleebu, Pontiano; Kwiatkowski, Dominic; Tyler-Smith, Chris; Rotimi, Charles; Zeggini, Eleftheria; Sandhu, Manjinder S.

    2015-01-01

    Given the importance of Africa to studies of human origins and disease susceptibility, detailed characterization of African genetic diversity is needed. The African Genome Variation Project provides a resource with which to design, implement and interpret genomic studies in sub-Saharan Africa and worldwide. The African Genome Variation Project represents dense genotypes from 1,481 individuals and whole-genome sequences from 320 individuals across sub-Saharan Africa. Using this resource, we find novel evidence of complex, regionally distinct hunter-gatherer and Eurasian admixture across sub-Saharan Africa. We identify new loci under selection, including loci related to malaria susceptibility and hypertension. We show that modern imputation panels (sets of reference genotypes from which unobserved or missing genotypes in study sets can be inferred) can identify association signals at highly differentiated loci across populations in sub-Saharan Africa. Using whole-genome sequencing, we demonstrate further improvements in imputation accuracy, strengthening the case for large-scale sequencing efforts of diverse African haplotypes. Finally, we present an efficient genotype array design capturing common genetic variation in Africa.

  15. Shaping 3-D Volumes in Immersive Virtual Environments

    DEFF Research Database (Denmark)

    Stenholt, Rasmus

    of the user’s work in such tasks. This tech- nique is compared to two other techniques, a spherical brush and a box-shaped lasso, in an evaluation which seeks to identify the pros and cons of the tools. The magic wand proves to be faster to use than the other, but only in certain geomet- ric scenarios...

  16. Variations in the shape of permanent maxillary lateral incisors in Sundanese.

    Science.gov (United States)

    Schlegel, D; Satravaha, S

    1984-01-01

    During a survey in Java we found unusual shaped upper lateral incisors. A total of 110 school children shows 3 cases with pegging, approximately 20% with canine-like shape. In all cases the lateral incisor was present. Compared with other publication the incidence of pegging is low, the canine-like variation never described as far as we know.

  17. Variation in heat sink shape for thermal analysis

    Science.gov (United States)

    Wong, C. M.; Aziz, M. H. B. A.; Ong, N. R.; Alcain, J. B.; Sauli, Z.

    2017-09-01

    The concern about the thermal performance of microelectronics is on the increase due to recent over-heating induced failures which have led to product recalls. Removal of excess heat from microelectronic systems with the use of heat sinks could improve thermal efficiency of the system. The shape of the heat sink model with difference fin configuration has significant influence on cooling performances. This paper investigates the effect of change in heat sink geometry on an electronic package through COMSOL Multiphysics software as well as the thermal performance of difference heat sink geometry corresponding to various air inlet velocities. Based on this study, plate fin heat sink has better thermal performance than strip pin fin and circular pin fin heat sink due to less obstruction of the heat sink design.

  18. Global variation in woodpecker species richness shaped by tree availability

    DEFF Research Database (Denmark)

    Ilsoe, Sigrid Kistrup; Kissling, W. Daniel; Fjeldsa, Jon

    2017-01-01

    . As an example, woodpeckers (Picidae) are closely associated with trees and woody habitats because of multiple morphological and ecological specializations. In this study, we test whether this strong biotic association causes woodpecker diversity to be closely linked to tree availability at a global scale....... Location: Global. Methods: We used spatial and non-spatial regressions to test for relationships between broad-scale woodpecker species richness and predictor variables describing current and deep-time availability of trees, current climate, Quaternary climate change, human impact, topographical...... a negative indirect effect on woodpecker species richness. Main conclusions: Global species richness of woodpeckers is primarily shaped by current tree cover and precipitation, reflecting a strong biotic association between woodpeckers and trees. Human influence can have a negative effect on woodpecker...

  19. Mothers may shape the variations in social organization among gorillas

    Science.gov (United States)

    Gray, Maryke; Breuer, Thomas; Manguette, Marie; Stokes, Emma J.; Uwingeli, Prosper; Mburanumwe, Innocent; Kagoda, Edwin; Robbins, Martha M.

    2016-01-01

    When mothers continue to support their offspring beyond infancy, they can influence the fitness of those offspring, the strength of social relationships within their groups, and the life-history traits of their species. Using up to 30 years of demographic data from 58 groups of gorillas in two study sites, this study extends such findings by showing that mothers may also contribute to differences in social organization between closely related species. Female mountain gorillas remained with their sons for significantly longer than western gorillas, which may explain why male philopatry and multimale groups are more common among mountain gorillas. The presence of the putative father and other familiar males did not vary significantly between species, and we found only limited support for the socio-ecological theory that the distribution of adult males is influenced by the distribution of females. Within each gorilla species, variations in those distributions may also reflect the different stages in the typical life cycle of a group. Collectively, our results highlight the potentially far-reaching consequences of maternal support that extends beyond infancy, and they illustrate the opportunity to incorporate additional factors into phylogenetic analyses of variations in social organization, including studies of human evolution. PMID:27853570

  20. Does Glass Size and Shape Influence Judgements of the Volume of Wine?

    Science.gov (United States)

    Pechey, Rachel; Attwood, Angela S; Couturier, Dominique-Laurent; Munafò, Marcus R; Scott-Samuel, Nicholas E; Woods, Andy; Marteau, Theresa M

    2015-01-01

    Judgements of volume may influence the rate of consumption of alcohol and, in turn, the amount consumed. The aim of the current study was to examine the impact of the size and shape of wine glasses on perceptions of wine volume. Online experiment: Participants (n = 360; recruited via Mechanical Turk) were asked to match the volume of wine in two wine glasses, specifically: 1. the Reference glass holding a fixed reference volume, and 2. the Comparison glass, for which the volume could be altered until participants perceived it matched the reference volume. One of three comparison glasses was shown in each trial: 'wider' (20% wider but same capacity); 'larger' (same width but 25% greater capacity); or 'wider-and-larger' (20% wider and 25% greater capacity). Reference volumes were 125 ml, 175 ml and 250 ml, in a fully factorial within-subjects design: 3 (comparison glass) x 3 (reference volume). Non-zero differences between the volumes with which participants filled comparison glasses and the corresponding reference volumes were identified using sign-rank tests. Participants under-filled the wider glass relative to the reference glass for larger reference volumes, and over-filled the larger glass relative to the reference glass for all reference volumes. Results for the wider-and-larger glass showed a mixed pattern across reference volume. For all comparison glasses, in trials with larger reference volumes participants tended to fill the comparison glass less, relative to trials with smaller reference volumes for the same comparison glass. These results are broadly consistent with people using the relative fullness of glasses to judge volume, and suggest both the shape and capacity of wine glasses may influence perceived volume. Perceptions that smaller glasses contain more than larger ones (despite containing the same volume), could slow drinking speed and overall consumption by serving standard portions in smaller glasses. This hypothesis awaits testing.

  1. Impact of elliptical shaped red oak logs on lumber grade and volume recovery

    Science.gov (United States)

    Patrick M. Rappold; Brian H. Bond; Janice K. Wiedenbeck; Roncs Ese-Etame

    2007-01-01

    This research examined the grade and volume of lumber recovered from red oak logs with elliptical shaped cross sections. The volume and grade of lumber recovered from red oak logs with low (e ≤ 0.3) and high (e ≥ 0.4) degrees of ellipticity was measured at four hardwood sawmills. There was no significant difference (...

  2. Habitat variation and wing coloration affect wing shape evolution in dragonflies.

    Science.gov (United States)

    Outomuro, D; Dijkstra, K-D B; Johansson, F

    2013-09-01

    Habitats are spatially and temporally variable, and organisms must be able to track these changes. One potential mechanism for this is dispersal by flight. Therefore, we would expect flying animals to show adaptations in wing shape related to habitat variation. In this work, we explored variation in wing shape in relation to preferred water body (flowing water or standing water with tolerance for temporary conditions) and landscape (forested to open) using 32 species of dragonflies of the genus Trithemis (80% of the known species). We included a potential source of variation linked to sexual selection: the extent of wing coloration on hindwings. We used geometric morphometric methods for studying wing shape. We also explored the phenotypic correlation of wing shape between the sexes. We found that wing shape showed a phylogenetic structure and therefore also ran phylogenetic independent contrasts. After correcting for the phylogenetic effects, we found (i) no significant effect of water body on wing shape; (ii) male forewings and female hindwings differed with regard to landscape, being progressively broader from forested to open habitats; (iii) hindwings showed a wider base in wings with more coloration, especially in males; and (iv) evidence for phenotypic correlation of wing shape between the sexes across species. Hence, our results suggest that natural and sexual selection are acting partially independently on fore- and hindwings and with differences between the sexes, despite evidence for phenotypic correlation of wing shape between males and females. © 2013 The Authors. Journal of Evolutionary Biology © 2013 European Society For Evolutionary Biology.

  3. Stereological Estimation of Particle Shape and Orientation From Volume Tensors

    DEFF Research Database (Denmark)

    H. Rafati, Ali; Ziegel, Johanna; Nyengaard, Jens Randel

    We survey the role of symmetry in diffeomorphic registration of landmarks, curves, surfaces, images and higher-order data. The infinite dimensional problem of finding correspondences between objects can for a range of concrete data types be reduced resulting in compact representations of shape....... Symmetry also arises in reduction to the Lie algebra using particle relabeling symmetry allowing the equations of motion to be written purely in terms of Eulerian velocity field. Reduction by symmetry has recently been applied for jet-matching and higher-order discrete approximations of the image matching...

  4. Clinical correlates of hippocampus volume and shape in antipsychotic-naïve schizophrenia.

    Science.gov (United States)

    Kalmady, Sunil Vasu; Shivakumar, Venkataram; Arasappa, Rashmi; Subramaniam, Aditi; Gautham, S; Venkatasubramanian, Ganesan; Gangadhar, Bangalore N

    2017-05-30

    While volume deficit of hippocampus is an established finding in schizophrenia, very few studies have examined large sample of patients without the confounding effect of antipsychotic treatment. Concurrent evaluation of hippocampus shape will offer additional information on the hippocampal aberrations in schizophrenia. In this study, we analyzed the volume and shape of hippocampus in antipsychotic-naïve schizophrenia patients (N=71) in comparison to healthy controls (N=82). Using 3-T MRI data, gray matter (GM) volume (anterior and posterior sub-divisions) and shape of the hippocampus were analyzed. Schizophrenia patients had significant hippocampal GM volume deficits (specifically the anterior sub-division) in comparison to healthy controls. There were significant positive correlations between anterior hippocampus volume and psychopathology scores of positive syndrome. Shape analyses revealed significant inward deformation of bilateral hippocampal surface in patients. In conclusion, our study findings add robust support for volume deficit in hippocampus in antipsychotic-naïve schizophrenia. Hippocampal shape deficits in schizophrenia observed in this study map to anterior CA1 sub-region. The differential relationship of anterior hippocampus (but not posterior hippocampus) with clinical symptoms is in tune with the findings in animal models. Further systematic studies are needed to evaluate the relationship between these hippocampal gray matter deficits with white matter and functional connectivity to facilitate understanding the hippocampal network abnormalities in schizophrenia. Copyright © 2017 Elsevier Ireland Ltd. All rights reserved.

  5. Effect of aging and degeneration on disc volume and shape: A quantitative study in asymptomatic volunteers.

    Science.gov (United States)

    Pfirrmann, Christian W A; Metzdorf, Alexander; Elfering, Achim; Hodler, Juerg; Boos, Norbert

    2006-05-01

    Debate continues on the effect of disc degeneration and aging on disc volume and shape. So far, no quantitative in vivo MRI data is available on the factors influencing disc volume and shape. The objective of this MRI study was to quantitatively investigate changes in disc height, volume, and shape as a result of aging and/or degeneration omitting pathologic (i.e., painful) disc alterations. Seventy asymptomatic volunteers (20-78 years) were investigated with sagittal T1- and T2-weighted MR-images encompassing the whole lumbar spine. Disc height was determined by the Dabbs method and the Farfan index. Disc volume was calculated by the Cavalieri method. For the disc shape the "disc convexity index" was calculated by the ratio of central disc height and mean anterior/posterior disc height. Disc height, disc volume, and the disc convexity index measurements were corrected for disc level and the individuals age, weight, height, and sex in a multilevel regression analysis. Multilevel regression analysis showed that disc volume was negatively influenced by disc degeneration (p < 0.001) and positively correlated with body height (p < 0.001) and age (p < 0.01). Mean disc height and the disc convexity index were negatively influenced by disc degeneration but not by gender, weight, and height. Disc height was positively correlated with age (p < 0.01). From the results of this study, it can be concluded that disc degeneration generally results in a decrease of disc height and volume as well as a less convex disc shape. In the absence of disc degeneration, however, age tends to result in an inverse relationship on disc height, volume, and shape. Copyright 2006 Orthopaedic Research Society.

  6. Neanderthal-Derived Genetic Variation Shapes Modern Human Cranium and Brain.

    Science.gov (United States)

    Gregory, Michael D; Kippenhan, J Shane; Eisenberg, Daniel P; Kohn, Philip D; Dickinson, Dwight; Mattay, Venkata S; Chen, Qiang; Weinberger, Daniel R; Saad, Ziad S; Berman, Karen F

    2017-07-24

    Before their disappearance from the fossil record approximately 40,000 years ago, Neanderthals, the ancient hominin lineage most closely related to modern humans, interbred with ancestors of present-day humans. The legacy of this gene flow persists through Neanderthal-derived variants that survive in modern human DNA; however, the neural implications of this inheritance are uncertain. Here, using MRI in a large cohort of healthy individuals of European-descent, we show that the amount of Neanderthal-originating polymorphism carried in living humans is related to cranial and brain morphology. First, as a validation of our approach, we demonstrate that a greater load of Neanderthal-derived genetic variants (higher "NeanderScore") is associated with skull shapes resembling those of known Neanderthal cranial remains, particularly in occipital and parietal bones. Next, we demonstrate convergent NeanderScore-related findings in the brain (measured by gray- and white-matter volume, sulcal depth, and gyrification index) that localize to the visual cortex and intraparietal sulcus. This work provides insights into ancestral human neurobiology and suggests that Neanderthal-derived genetic variation is neurologically functional in the contemporary population.

  7. Deformation-based nuclear morphometry: capturing nuclear shape variation in HeLa cells.

    Science.gov (United States)

    Rohde, Gustavo K; Ribeiro, Alexandre J S; Dahl, Kris N; Murphy, Robert F

    2008-04-01

    The empirical characterization of nuclear shape distributions is an important unsolved problem with many applications in biology and medicine. Numerous genetic diseases and cancers have alterations in nuclear morphology, and methods for characterization of morphology could aid in both diagnoses and fundamental understanding of these disorders. Automated approaches have been used to measure features related to the size and shape of the cell nucleus, and statistical analysis of these features has often been performed assuming an underlying Euclidean (linear) vector space. We discuss the difficulties associated with the analysis of nuclear shape in light of the fact that shape spaces are nonlinear, and demonstrate methods for characterizing nuclear shapes and shape distributions based on spatial transformations that map one nucleus to another. By combining large deformation metric mapping with multidimensional scaling we offer a flexible approach for elucidating the intrinsic nonlinear degrees of freedom of a distribution of nuclear shapes. More specifically, we demonstrate approaches for nuclear shape interpolation and computation of mean nuclear shape. We also provide a method for estimating the number of free parameters that contribute to shape as well as an approach for visualizing most representative shape variations within a distribution of nuclei. The proposed methodology can be completely automated, is independent of the dimensionality of the images, and can handle complex shapes. Results obtained by analyzing two sets of images of HeLa cells are shown. In addition to identifying the modes of variation in normal HeLa nuclei, the effects of lamin A/C on nuclear morphology are quantitatively described. (c) 2007 International Society for Analytical Cytology.

  8. Determination of protein and solvent volumes in protein crystals from contrast variation data

    Energy Technology Data Exchange (ETDEWEB)

    Badger, J. [Brandeis Univ., Waltham, MA (United States)

    1994-12-31

    By varying the relative values of protein and solvent scattering densities in a crystal, it is possible to obtain information on the shape and dimensions of protein molecular envelopes. Neutron diffraction methods are ideally suited to these contrast variation experiments because H/D exchange leads to large differential changes in the protein and solvent scattering densities and is structurally non-perturbing. Low resolution structure factors have been measured from cubic insulin crystals with differing H/D contents. Structure factors calculated from a simple binary density model, in which uniform scattering densities represent the protein and solvent volumes in the crystals, were compared with these data. The contrast variation differences in the sets of measured structure factors were found to be accurately fitted by this simple model. Trial applications to two problems in crystal structure determination illustrate how this fact may be exploited. (1) A translation function that employs contrast variation data gave a sharp minimum within 1-9{Angstrom} of the correctly positioned insulin molecule and is relatively insensitive to errors in the atomic model. (2) An ab initio phasing method for the contrast variation data, based on analyzing histograms of the density distributions in trial maps, was found to recover the correct molecular envelope.

  9. Support for the shape concept of lipid structure based on a headgroup volume approach.

    OpenAIRE

    Lee, Y. C.; Taraschi, T F; Janes, N

    1993-01-01

    Headgroup volumes of seven dioleoyl lipid species, calculated from covalent radii, are shown to correlate linearly (r = 0.95) with the ability of those lipids to alter the midpoint temperature of the lamellar to inverted hexagonal phase transition (L alpha-->HII) of a 95 mole fraction percent phosphatidylethanolamine matrix. The results illustrate the utility of the shape concept and basic considerations of headgroup volume as a predictive tool for the determination of lipid structure.

  10. Shape variation in the human pelvis and limb skeleton: Implications for obstetric adaptation.

    Science.gov (United States)

    Kurki, Helen K; Decrausaz, Sarah-Louise

    2016-04-01

    Under the obstetrical dilemma (OD) hypothesis, selection acts on the human female pelvis to ensure a sufficiently sized obstetric canal for birthing a large-brained, broad shouldered neonate, while bipedal locomotion selects for a narrower and smaller pelvis. Despite this female-specific stabilizing selection, variability of linear dimensions of the pelvic canal and overall size are not reduced in females, suggesting shape may instead be variable among females of a population. Female canal shape has been shown to vary among populations, while male canal shape does not. Within this context, we examine within-population canal shape variation in comparison with that of noncanal aspects of the pelvis and the limbs. Nine skeletal samples (total female n = 101, male n = 117) representing diverse body sizes and shapes were included. Principal components analysis was applied to size-adjusted variables of each skeletal region. A multivariate variance was calculated using the weighted PC scores for all components in each model and F-ratios used to assess differences in within-population variances between sexes and skeletal regions. Within both sexes, multivariate canal shape variance is significantly greater than noncanal pelvis and limb variances, while limb variance is greater than noncanal pelvis variance in some populations. Multivariate shape variation is not consistently different between the sexes in any of the skeletal regions. Diverse selective pressures, including obstetrics, locomotion, load carrying, and others may act on canal shape, as well as genetic drift and plasticity, thus increasing variation in morphospace while protecting obstetric sufficiency. © 2015 Wiley Periodicals, Inc.

  11. Size Variation under Domestication: Conservatism in the inner ear shape of wolves, dogs and dingoes.

    Science.gov (United States)

    Schweizer, Anita V; Lebrun, Renaud; Wilson, Laura A B; Costeur, Loïc; Schmelzle, Thomas; Sánchez-Villagra, Marcelo R

    2017-10-17

    A broad sample of wolves, dingoes, and domesticated dogs of different kinds and time periods was used to identify changes in size and shape of the organs of balance and hearing related to domestication and to evaluate the potential utility of uncovered patterns as markers of domestication. Using geometric morphometrics coupled with non-invasive imaging and three-dimensional reconstructions, we exposed and compared complex structures that remain largely conserved. There is no statistically significant difference in the levels of shape variation between prehistoric and modern dogs. Shape variance is slightly higher for the different components of the inner ear in modern dogs than in wolves, but these differences are not significant. Wolves express a significantly greater level of variance in the angle between the lateral and the posterior canal than domestic dog breeds. Wolves have smaller levels of size variation than dogs. In terms of the shape of the semicircular canals, dingoes reflect the mean shape in the context of variation in the sample. This mirrors the condition of feral forms in other organs, in which there is an incomplete return to the characteristics of the ancestor. In general, morphological diversity or disparity in the inner ear is generated by scaling.

  12. Effect of tidal volume, sampling duration, and cardiac contractility on pulse pressure and stroke volume variation during positive-pressure ventilation.

    Science.gov (United States)

    Kim, Hyung Kook; Pinsky, Michael R

    2008-10-01

    Both pulse pressure variation and stroke volume variation during intermittent positive-pressure ventilation predict preload responsiveness. However, because ventilatory and cardiac frequencies are not the same, increasing the number of breaths sampled may increase calculated pulse pressure variation and stroke volume variation because larger (max) and smaller (min) pulse pressure and stroke volume may occur. Tidal volume and contractility may also alter pulse pressure variation and stroke volume variation. We hypothesized that the magnitude of pulse pressure variation would increase with sampling duration, and that both tidal volume and contractility would independently alter pulse pressure variation and stroke volume variation. In seven pentobarbital-anesthetized intact dogs arterial and left ventricular pressure (Millar) and left ventricular volume (Leycom) were measured over 8 intermittent positive-pressure ventilation breaths at tidal volume of 5, 10, 15, and 20 mL/kg (f = 20/min, 40% inspiratory time) under baseline, esmolol (2 mg/min), dobutamine infusions (5 microg/kg/min) and following volume loading (500 mL NaCl). Stroke volume variation was calculated using pulse contour method (PiCCO, Pulsion Medical Systems, Munich, Germany) averaged over 12 secs. Pulse pressure variation was calculated as 100 x (PPmax - PPmin)/PPmean and calculated over 1, 2, 3, 4, 5, 6, 7, or 8 breaths. Pulse pressure variation increased progressively with increasing sampling duration up to but not exceeding five breaths. The effect on sampling duration was increased by greater tidal volume. Esmolol infusion decreased both pulse pressure variation and stroke volume variation as compared with baseline (p variation or stroke volume variation. Sampling duration, tidal volume, and beta-adrenergic blockade differentially alters pulse pressure variation and stroke volume variation during intermittent positive-pressure ventilation. Thus, separate validation is required to define threshold

  13. Moderate intensity supine exercise causes decreased cardiac volumes and increased outer volume variations: a cardiovascular magnetic resonance study

    DEFF Research Database (Denmark)

    Steding-Ehrenborg, Katarina; Jablonowski, Robert; Arvidsson, Per M

    2013-01-01

    The effects on left and right ventricular (LV, RV) volumes during physical exercise remains controversial. Furthermore, no previous study has investigated the effects of exercise on longitudinal contribution to stroke volume (SV) and the outer volume variation of the heart. The aim of this study ...... was to determine if LV, RV and total heart volumes (THV) as well as cardiac pumping mechanisms change during physical exercise compared to rest using cardiovascular magnetic resonance (CMR).......The effects on left and right ventricular (LV, RV) volumes during physical exercise remains controversial. Furthermore, no previous study has investigated the effects of exercise on longitudinal contribution to stroke volume (SV) and the outer volume variation of the heart. The aim of this study...

  14. Changes in hemoglobin-oxygen affinity with shape variations of red blood cells

    Science.gov (United States)

    Chowdhury, Aniket; Dasgupta, Raktim; Majumder, Shovan K.

    2017-10-01

    Shape variations of red blood cells (RBCs) are known to occur upon exposure to various drugs or under diseased conditions. The commonly observed discocytic RBCs can be transformed to echinocytic or stomatocytic shape under such conditions. Raman spectra of the three major shape variations, namely discocyte, echinocyte, and stomatocyte, of RBCs were studied while subjecting the cells to oxygenated and deoxygenated conditions. Analysis of the recorded spectra suggests an increased level of hemoglobin (Hb)-oxygen affinity for the echinocytes. Also, some level of Hb degradation could be noticed for the deoxygenated echinocytes. The effects may arise from a reduced level of intracellular adenosine triphosphate in echinocytic cells and an increased fraction of submembrane Hb.

  15. Intraspecific shape variation in horseshoe crabs: the importance of sexual and natural selection for local adaptation

    DEFF Research Database (Denmark)

    Faurby, Søren; Nielsen, Kasper Sauer Kollerup; Bussarawit, Somchai

    2011-01-01

    A morphometric analysis of the body shape of three species of horseshoe crabs was undertaken in order to infer the importance of natural and sexual selection. It was expected that natural selection would be most intense, leading to highest regional differentiation, in the American species Limulus...... polyphemus, which has the largest climatic differences between different populations. Local adaptation driven by sexual selection was expected in males but not females because horseshoe crab mating behaviour leads to competition between males, but not between females. Three hundred fifty-nine horseshoe crabs....... Differences in shape variation between sexes were tested with F-tests, which showed lower intrapopulation morphometric variation in males than females. These results indicate a lower degree of local adaptation on body shape in C. rotundicauda and T. gigas than in L. polyphemus and a lower degree of local...

  16. Head-and-face shape variations of U.S. civilian workers.

    Science.gov (United States)

    Zhuang, Ziqing; Shu, Chang; Xi, Pengcheng; Bergman, Michael; Joseph, Michael

    2013-09-01

    The objective of this study was to quantify head-and-face shape variations of U.S. civilian workers using modern methods of shape analysis. The purpose of this study was based on previously highlighted changes in U.S. civilian worker head-and-face shape over the last few decades - touting the need for new and better fitting respirators - as well as the study's usefulness in designing more effective personal protective equipment (PPE) - specifically in the field of respirator design. The raw scan three-dimensional (3D) data for 1169 subjects were parameterized using geometry processing techniques. This process allowed the individual scans to be put in correspondence with each other in such a way that statistical shape analysis could be performed on a dense set of 3D points. This process also cleaned up the original scan data such that the noise was reduced and holes were filled in. The next step, statistical analysis of the variability of the head-and-face shape in the 3D database, was conducted using Principal Component Analysis (PCA) techniques. Through these analyses, it was shown that the space of the head-and-face shape was spanned by a small number of basis vectors. Less than 50 components explained more than 90% of the variability. Furthermore, the main mode of variations could be visualized through animating the shape changes along the PCA axes with computer software in executable form for Windows XP. The results from this study in turn could feed back into respirator design to achieve safer, more efficient product style and sizing. Future study is needed to determine the overall utility of the point cloud-based approach for the quantification of facial morphology variation and its relationship to respirator performance. Copyright © 2013 Elsevier Ltd and The Ergonomics Society. All rights reserved.

  17. MRT letter: Guided filtering of image focus volume for 3D shape recovery of microscopic objects.

    Science.gov (United States)

    Mahmood, Muhammad Tariq

    2014-12-01

    In this letter, a shape from focus (SFF) method is proposed that utilizes the guided image filtering to enhance the image focus volume efficiently. First, image focus volume is computed using a conventional focus measure. Then each layer of image focus volume is filtered using guided filtering. In this work, the all-in-focus image, which can be obtained from the initial focus volume, is used as guidance image. Finally, improved depth map is obtained from the filtered image focus volume by maximizing the focus measure along the optical axis. The proposed SFF method is efficient and provides better depth maps. The improved performance is highlighted by conducting several experiments using image sequences of simulated and real microscopic objects. The comparative analysis demonstrates the effectiveness of the proposed SFF method. © 2014 Wiley Periodicals, Inc.

  18. Size and shape variations of the bony components of sperm whale cochleae

    Science.gov (United States)

    Schnitzler, Joseph G.; Frédérich, Bruno; Früchtnicht, Sven; Schaffeld, Tobias; Baltzer, Johannes; Ruser, Andreas; Siebert, Ursula

    2017-01-01

    Several mass strandings of sperm whales occurred in the North Sea during January and February 2016. Twelve animals were necropsied and sampled around 48 h after their discovery on German coasts of Schleswig Holstein. The present study aims to explore the morphological variation of the primary sensory organ of sperm whales, the left and right auditory system, using high-resolution computerised tomography imaging. We performed a quantitative analysis of size and shape of cochleae using landmark-based geometric morphometrics to reveal inter-individual anatomical variations. A hierarchical cluster analysis based on thirty-one external morphometric characters classified these 12 individuals in two stranding clusters. A relative amount of shape variation could be attributable to geographical differences among stranding locations and clusters. Our geometric data allowed the discrimination of distinct bachelor schools among sperm whales that stranded on German coasts. We argue that the cochleae are individually shaped, varying greatly in dimensions and that the intra-specific variation observed in the morphology of the cochleae may partially reflect their affiliation to their bachelor school. There are increasing concerns about the impact of noise on cetaceans and describing the auditory periphery of odontocetes is a key conservation issue to further assess the effect of noise pollution. PMID:28440286

  19. Morphological variation in a larval salamander: dietary induction of plasticity in head shape.

    Science.gov (United States)

    Walls, Susan C; Belanger, Secret S; Blaustein, Andrew R

    1993-11-01

    We examined diet-dependent plasticity in head shape in larvae of the eastern long-toed salamander, Ambystoma macrodactylum columbianum. Larvae in some populations of this species exhibit trophic polymorphism, with some individuals possessing exaggerated trophic features characteristic of a cannibalistic morphology in larval Ambystoma; e.g. a disproportionately broad head and hypertrophied vomerine teeth. We hypothesized that 1) head shape variation results from feeding upon different types of prey and that 2) cannibal morphs are induced by consumption of conspecifics. To induce variation, we fed three groups of larvae different diets: 1) brine shrimp nauplii only; 2) nauplii plus anuran tadpoles; 3) nauplii, tadpoles and conspecific larval salamanders. Comparisons of size (mass)-adjusted means revealed that this manipulation of diet induced significant variation in six measures of head shape, but not in the area of the vomerine tooth patch. For five of the six head traits, larvae that ate tadpoles and brine shrimp nauplii developed significantly broader, longer and deeper heads than did larvae that only ate brine shrimp nauplii. The ingestion of conspecifics, in addition to nauplii and tadpoles, significantly altered two head traits (interocular-width and head depth), compared to larvae only fed nauplii and tadpoles. Canonical discriminant function analysis detected two statistically reliable canonical variables: head depth was most highly associated with the first canonical variable, whereas three measures of head width (at the jaws, gills and eyes) and interocular width were most highly associated with the second canonical variable. Despite this diet-enhanced morphological variation, there was no indication that any of the three types of diet (including conspecific prey) induced the exaggerated trophic features of the "cannibal" morph in this species. These results illustrate that ingestion of different types of prey contributes to plasticity in head shape, but

  20. Dynamics of pear-shaped dimensions and volume of intracavitary brachytherapy in cancer of the cervix: a desirable pear shape in the era of three-dimensional treatment planning.

    Science.gov (United States)

    Kim, R Y; Caranto, J F; Pareek, P N; Virostek, L J

    1997-03-15

    To evaluate the dynamics of pear-shaped dimensions and volume of the intracavitary brachytherapy, and to define a desirable pear-shape in the era of three-dimensional (3D) treatment planning. Since Point A has been used for the dose specification, the pear shape defined the surface enclosed by Point A. This study utilized a new method of evaluating pear-shaped dimensions and its configuration. The pear shape was artificially divided into tandem and colpostat portions for evaluation of its changes. Width, height, and thickness at the tandem portion (Wt, Ht, and Tt) and at the colpostat portion (Wc, Hc, and Tc) were defined, respectively, on the frontal and sagittal plane. To evaluate the dynamics of the pear-shape configuration, 12 variations of applicator geometry and source loading were applied to generate the pear-shape isodose line and dose-volume histogram. When the source strengths in the colpostats were reduced for optimization with the same dose to Point A dose, Wc, Hc, and Tc were decreased, whereas Wt, Ht, and Tt were increased without a change in the overall pear-shaped volume. When the separation of the colpostats was increased without a change in the source strength, Wc was increased, whereas Hc and Tc were reduced without a change in Wt, Ht, Tt and overall pear-shape volume. When the separation of colpostats and distal tandem source were increased, these changes at the colpostat portion were magnified. However, when both colpostat separation and its source strength were increased proportionally, Wc, Hc, and Tc were increased proportionally as well as its volume. The dose specification at Point A is less meaningful without a desirable pear shape encompassing the tumor around the cervix. In the era of 3D treatment planning, understanding the dynamics of the pear shape should improve the individualized dosimetry according to tumor size and location. The relationships between a desirable pear shape and its tumor coverage should establish a more reliable

  1. Changes in rabbit and cow lens shape and volume upon imposition of anisotonic conditions.

    Science.gov (United States)

    Kong, Chi-Wing; Gerometta, Rosana; Alvarez, Lawrence J; Candia, Oscar A

    2009-10-01

    In vivo, mammalian lenses have the capacity to effect fully reversible changes in shape, and possibly volume, during the accommodation process. Isolated lenses also change shape by readily swelling or shrinking when placed in anisotonic media. However, the manner by which the lens changes its shape when its volume is changed osmotically is not firmly established. Putatively, the lens could swell or shrink evenly in all directions, or manifest distinctive swelling and/or shrinking patterns when exposed to anisotonic media. The present study measured physical changes in lenses consistent with the latter alternative using methods we developed for determining rapid changes in lens shape and volume. It was found in isolated rabbit and cow lenses that the length of the axis between the anterior and posterior poles (A-P length) primarily increases under hypotonic conditions (-40 to -100 mOsM), with smaller, or no changes, in equatorial diameter (ED). Hypertonic conditions (+50 to +100 mOsM) on rabbit lenses elicited a predominant reduction in ED, while the A-P length was only marginally reduced. Hypertonic solutions of +150 mOsM were required to obtain similar changes in cow lens shape. The ratio of the A-P length to the ED was taken as a measure of "circularity". This ratio increased gradually in rabbit and cow lenses bathed in hypotonic solutions because of the increase in the A-P length. The calculated lens volume increased in tandem with the increase in "circularity". Lens circularity also increased under hypertonic conditions due to the decrease in ED, but this increase in circularity during shrinkage was not as pronounced as that which occurred during swelling. As such, the lens has a tendency upon swelling to change its shape by approaching the structure of a globular spheroid (as occurs during accommodation for near focusing), but lens shrinkage does not result in a flatter lens with a reduced A-P length as occurs during dis-accommodation for distance focusing

  2. Effect of transformation volume contraction on the toughness of superelastic shape memory alloys

    Science.gov (United States)

    Yan, Wenyi; Wang, Chun Hui; Zhang, Xin Ping; Mai, Yiu-Wing

    2002-12-01

    Shape memory alloys (SMAs) exhibit two very important properties: shape memory phenomenon and superelastic deformation due to intrinsic thermoelastic martensitic transformation. To fully exploit the potential of SMAs in developing functional structures or smart structures in mechanical and biomechanical engineering, it is important to understand and quantify the failure mechanisms of SMAs. This paper presents a theoretical study of the effect of phase-transformation-induced volume contraction on the fracture properties of superelastic SMAs. A simple model is employed to account for the forward and reverse phase transformation with pure volume change, which is then applied to numerically study the transformation field near the tip of a tensile crack. The results reveal that during steady-state crack propagation, the transformation zone extends ahead of the crack tip due to forward transformation while partial reverse transformation occurs in the wake. Furthermore, as a result of the volume contraction associated with the austenite-to-martensite transformation, the induced stress-intensity factor is positive. This is in stark contrast with the negative stress-intensity factor achieved in zirconia ceramics, which undergoes volume expansion during phase transformation. The reverse transformation has been found to have a negligible effect on the induced stress-intensity factor. An important implication of the present results is that the phase transformation with volume contraction in SMAs tends to reduce their fracture resistance and increase the brittleness.

  3. Temperature Condition and Spherical Shell Shape Variation of Space Gauge-Alignment Spacecraft

    Directory of Open Access Journals (Sweden)

    V. S. Zarubin

    2016-01-01

    Full Text Available A high precision spherical shell is one of the geometrical shape embodiments of a gaugealignment spacecraft to determine and control a radar channel energy potential of the ground-based complex for the traffic control of space objects. Passive relays of signals and some types of smallsized instrumentation standard reflectors used for radar gauge and alignment have the same shape. Orbits of the considered spacecraft can be either circular with a height of about 1000 km, including those close to the polar, or elliptical with an apogee of up to 2200 km.In case there is no thermal control system in spacecrafts of these types the solar radiation is a major factor to define the thermal state of a spherical shell in the illuminated orbit area. With the shell in fixed position with respect to direction towards the Sun an arising uneven temperature distribution over its surface leads to variation of the spherically ideal shell shape, which may affect the functional characteristics of the spacecraft. The shell rotation about an axis perpendicular to the direction towards the Sun may reduce an unevenness degree of the temperature distribution.The uneven temperature distribution over the spherical shell surface in conditions of the lowEarth space and this unevenness impact on the shell shape variation against its spherical shape can be quantively estimated by the appropriate methods of mathematical modeling using modification of a previously developed mathematical model to describe steady temperature state of such shell on the low-Earth orbit. The paper considers the shell made from a polymeric composite material. Its original spherical shape is defined by rather low internal pressure. It is assumed that equipment in the shell, if any, is quite small-sized. This allows us to ignore its impact on the radiative transfer in the shell cavity. Along with defining the steady temperature distribution over the shell surface at its fixed orientation with respect to

  4. Shape and deformation measurements of 3D objects using volume speckle field and phase retrieval

    DEFF Research Database (Denmark)

    Anand, A; Chhaniwal, VK; Almoro, Percival

    2009-01-01

    the shape and deformation of 3D objects from the sequential intensity measurements of volume speckle field and phase retrieval based on angular-spectrum propagation technique is described here. The shape of a convex spherical surface was measured directly from the calculated phase map, and micrometer......Shape and deformation measurement of diffusely reflecting 3D objects are very important in many application areas, including quality control, nondestructive testing, and design. When rough objects are exposed to coherent beams, the scattered light produces speckle fields. A method to measure......-sized deformation induced on a metal sheet was obtained upon subtraction of the phase, corresponding to unloaded and loaded states. Results from computer simulations confirm the experiments. (C) 2009 Optical Society of America....

  5. Scaling and shear transformations capture beak shape variation in Darwin’s finches

    Science.gov (United States)

    Campàs, O.; Mallarino, R.; Herrel, A.; Abzhanov, A.; Brenner, M. P.

    2010-01-01

    Evolution by natural selection has resulted in a remarkable diversity of organism morphologies that has long fascinated scientists and served to establish the first relations among species. Despite the essential role of morphology as a phenotype of species, there is not yet a formal, mathematical scheme to quantify morphological phenotype and relate it to both the genotype and the underlying developmental genetics. Herein we demonstrate that the morphological diversity in the beaks of Darwin’s Finches is quantitatively accounted for by the mathematical group of affine transformations. Specifically, we show that all beak shapes of Ground Finches (genus Geospiza) are related by scaling transformations (a subgroup of the affine group), and the same relationship holds true for all the beak shapes of Tree, Cocos, and Warbler Finches (three distinct genera). This analysis shows that the beak shapes within each of these groups differ only by their scales, such as length and depth, which are genetically controlled by Bmp4 and Calmodulin. By measuring Bmp4 expression in the beak primordia of the species in the genus Geospiza, we provide a quantitative map between beak morphology and the expression levels of Bmp4. The complete morphological variation within the beaks of Darwin’s finches can be explained by extending the scaling transformations to the entire affine group, by including shear transformations. Altogether our results suggest that the mathematical theory of groups can help decode morphological variation, and points to a potentially hierarchical structure of morphological diversity and the underlying developmental processes. PMID:20160106

  6. Objective definition of rosette shape variation using a combined computer vision and data mining approach.

    Science.gov (United States)

    Camargo, Anyela; Papadopoulou, Dimitra; Spyropoulou, Zoi; Vlachonasios, Konstantinos; Doonan, John H; Gay, Alan P

    2014-01-01

    Computer-vision based measurements of phenotypic variation have implications for crop improvement and food security because they are intrinsically objective. It should be possible therefore to use such approaches to select robust genotypes. However, plants are morphologically complex and identification of meaningful traits from automatically acquired image data is not straightforward. Bespoke algorithms can be designed to capture and/or quantitate specific features but this approach is inflexible and is not generally applicable to a wide range of traits. In this paper, we have used industry-standard computer vision techniques to extract a wide range of features from images of genetically diverse Arabidopsis rosettes growing under non-stimulated conditions, and then used statistical analysis to identify those features that provide good discrimination between ecotypes. This analysis indicates that almost all the observed shape variation can be described by 5 principal components. We describe an easily implemented pipeline including image segmentation, feature extraction and statistical analysis. This pipeline provides a cost-effective and inherently scalable method to parameterise and analyse variation in rosette shape. The acquisition of images does not require any specialised equipment and the computer routines for image processing and data analysis have been implemented using open source software. Source code for data analysis is written using the R package. The equations to calculate image descriptors have been also provided.

  7. Objective definition of rosette shape variation using a combined computer vision and data mining approach.

    Directory of Open Access Journals (Sweden)

    Anyela Camargo

    Full Text Available Computer-vision based measurements of phenotypic variation have implications for crop improvement and food security because they are intrinsically objective. It should be possible therefore to use such approaches to select robust genotypes. However, plants are morphologically complex and identification of meaningful traits from automatically acquired image data is not straightforward. Bespoke algorithms can be designed to capture and/or quantitate specific features but this approach is inflexible and is not generally applicable to a wide range of traits. In this paper, we have used industry-standard computer vision techniques to extract a wide range of features from images of genetically diverse Arabidopsis rosettes growing under non-stimulated conditions, and then used statistical analysis to identify those features that provide good discrimination between ecotypes. This analysis indicates that almost all the observed shape variation can be described by 5 principal components. We describe an easily implemented pipeline including image segmentation, feature extraction and statistical analysis. This pipeline provides a cost-effective and inherently scalable method to parameterise and analyse variation in rosette shape. The acquisition of images does not require any specialised equipment and the computer routines for image processing and data analysis have been implemented using open source software. Source code for data analysis is written using the R package. The equations to calculate image descriptors have been also provided.

  8. A non-invasive geometric morphometrics method for exploring variation in dorsal head shape in urodeles: sexual dimorphism and geographic variation in Salamandra salamandra.

    Science.gov (United States)

    Alarcón-Ríos, Lucía; Velo-Antón, Guillermo; Kaliontzopoulou, Antigoni

    2017-04-01

    The study of morphological variation among and within taxa can shed light on the evolution of phenotypic diversification. In the case of urodeles, the dorso-ventral view of the head captures most of the ontogenetic and evolutionary variation of the entire head, which is a structure with a high potential for being a target of selection due to its relevance in ecological and social functions. Here, we describe a non-invasive procedure of geometric morphometrics for exploring morphological variation in the external dorso-ventral view of urodeles' head. To explore the accuracy of the method and its potential for describing morphological patterns we applied it to two populations of Salamandra salamandra gallaica from NW Iberia. Using landmark-based geometric morphometrics, we detected differences in head shape between populations and sexes, and an allometric relationship between shape and size. We also determined that not all differences in head shape are due to size variation, suggesting intrinsic shape differences across sexes and populations. These morphological patterns had not been previously explored in S. salamandra, despite the high levels of intraspecific diversity within this species. The methodological procedure presented here allows to detect shape variation at a very fine scale, and solves the drawbacks of using cranial samples, thus increasing the possibilities of using collection specimens and alive animals for exploring dorsal head shape variation and its evolutionary and ecological implications in urodeles. J. Morphol. 278:475-485, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  9. Low variation and high reproducibility in plaque volume with intravascular ultrasound

    DEFF Research Database (Denmark)

    Jensen, Lisette Okkels; Thayssen, Per; Pedersen, Knud Erik

    2004-01-01

    BACKGROUND: Intravascular ultrasound (IVUS) has several advantages compared to angiography when evaluating coronary atherosclerosis in the vessel wall. METHODS: The accuracy, reproducibility, and short-time spontaneous variation in volume of vessel, plaque and lumen were studied by electrocardiog...

  10. Impact of variation in limb shape on sub-bandage interface pressure.

    Science.gov (United States)

    Al Khaburi, J; Nelson, E A; Hutchinson, J; Dehghani-Sanij, A A

    2011-02-01

    Sub-bandage interface pressure generated by medical compression bandages (MCB) and hosiery changes in mobile patients as they move due to the change in the limb size. However, the amount of variation in the interface pressure is dependent on the stiffness of the compression material. Researchers have proposed several indices to describe this change in interface pressure, including the static stiffness index (SSI) and the dynamic stiffness index (DSI). These indices can also be used to classify compression products. To explore the different proposed indices to describe the stiffness of a compression material and compare it to the engineering stress-strain modulus which is used for the same purpose; To estimate theoretically the change in the interface pressure which is caused by the change in the limb shape as a consequence of calf muscle activity and the associated transient variation in limb dimensions. Use Chord modulus to classify compression material; Use thin and thick cylinder wall theory to estimate the variation in the interface pressure due to changes in the limb shape secondary to muscle contraction; Use tensile test devices to obtain the Chord modulus for two different MCB at two different dynamic ranges. Chord modulus (E) describes the change in tension in a dynamic situation, and this is labelled as stiffness in the bandaging literature; Chord modulus, with the help of a mathematical model that was developed based on thick wall cylinder theory, can be used to predict the change in sub-bandage interface pressure caused by the change in limb shape secondary to calf muscle activity; Chord modulus can be used to classify bandages and describe how they will behave when they are applied to a leg. The dynamic pressure can be predicted using a simple mathematical model using Chord modulus, which can be calculated in vitro using standard tensile testing equipment. In addition, Chord modulus can be used to classify compression bandages and hosiery.

  11. The shape and surface variation of 2 Pallas from the Hubble Space Telescope.

    Science.gov (United States)

    Schmidt, B E; Thomas, P C; Bauer, J M; Li, J-Y; McFadden, L A; Mutchler, M J; Radcliffe, S C; Rivkin, A S; Russell, C T; Parker, J Wm; Stern, S A

    2009-10-09

    We obtained Hubble Space Telescope images of 2 Pallas in September 2007 that reveal distinct color and albedo variations across the surface of this large asteroid. Pallas's shape is an ellipsoid with radii of 291 (+/-9), 278 (+/-9), and 250 (+/-9) kilometers, implying a density of 2400 (+/-250) kilograms per cubic meter-a value consistent with a body that formed from water-rich material. Our observations are consistent with the presence of an impact feature, 240 (+/-25) kilometers in diameter, within Pallas's ultraviolet-dark terrain. Our observations imply that Pallas is an intact protoplanet that has undergone impact excavation and probable internal alteration.

  12. Volume 10 No. 11 November 2010 4320 IONOMIC VARIATION ...

    African Journals Online (AJOL)

    user

    2010-11-11

    Nov 11, 2010 ... ionome grading; (2) Assess variation among accessions based on single element criterion; (3) Characterize ... The single element K discriminator basis was highly significant (p<.001) relative to the other elements but ..... were obtained. The curve passed through the origin and bracketed the concentrations.

  13. "Staying in the Game": How Procedural Variation Shapes Competence Judgments in Surgical Education.

    Science.gov (United States)

    Apramian, Tavis; Cristancho, Sayra; Watling, Chris; Ott, Michael; Lingard, Lorelei

    2016-11-01

    Emerging research explores the educational implications of practice and procedural variation between faculty members. The potential effect of these variations on how surgeons make competence judgments about residents has not yet been thoroughly theorized. The authors explored how thresholds of principle and preference shaped surgeons' intraoperative judgments of resident competence. This grounded theory study included reanalysis of data on the educational role of procedural variations and additional sampling to attend to their impact on assessment. Reanalyzed data included 245 hours of observation across 101 surgical cases performed by 29 participants (17 surgeons, 12 residents), 39 semistructured interviews (33 with surgeons, 6 with residents), and 33 field interviews with residents. The new data collected to explore emerging findings related to assessment included two semistructured interviews and nine focused field interviews with residents. Data analysis used constant comparison to refine the framework and data collection process until theoretical saturation was reached. The core category of the study, called staying in the game, describes how surgeons make moment-to-moment judgments to allow residents to retain their role as operators. Surgeons emphasized the role of principles in making these decisions, while residents suggested that working with surgeons' preferences also played an important role in such intraoperative assessment. These findings suggest that surgeons' and residents' work with thresholds of principle and preference have significant implications for competence judgments. Making use of these judgments by turning to situated assessment may help account for the subjectivity in assessment fostered by faculty variations.

  14. “Staying in the Game”: How Procedural Variation Shapes Competence Judgments in Surgical Education

    Science.gov (United States)

    Apramian, Tavis; Cristancho, Sayra; Watling, Chris; Ott, Michael; Lingard, Lorelei

    2017-01-01

    Purpose Emerging research explores the educational implications of practice and procedural variation between faculty members. The potential effect of these variations on how surgeons make competence judgments about residents has not yet been thoroughly theorized. The authors explored how thresholds of principle and preference shaped surgeons’ intraoperative judgments of resident competence. Method This grounded theory study included reanalysis of data on the educational role of procedural variations and additional sampling to attend to their impact on assessment. Reanalyzed data included 245 hours of observation across 101 surgical cases performed by 29 participants (17 surgeons, 12 residents), 39 semistructured interviews (33 with surgeons, 6 with residents), and 33 field interviews with residents. The new data collected to explore emerging findings related to assessment included two semistructured interviews and nine focused field interviews with residents. Data analysis used constant comparison to refine the framework and data collection process until theoretical saturation was reached. Results The core category of the study, called staying in the game, describes how surgeons make moment-to-moment judgments to allow residents to retain their role as operators. Surgeons emphasized the role of principles in making these decisions, while residents suggested that working with surgeons’ preferences also played an important role in such intraoperative assessment. Conclusions These findings suggest that surgeons’ and residents’ work with thresholds of principle and preference have significant implications for competence judgments. Making use of these judgments by turning to situated assessment may help account for the subjectivity in assessment fostered by faculty variations. PMID:27779508

  15. Corneal Shape, Volume, and Interocular Symmetry: Parameters to Optimize the Design of Biosynthetic Corneal Substitutes.

    Science.gov (United States)

    Durr, Georges M; Auvinet, Edouard; Ong, Jeb; Meunier, Jean; Brunette, Isabelle

    2015-07-01

    To characterize the three-dimensional (3D) shape, volume distribution, and mirror symmetry of the right and left corneas at the scale of a large population, based on the integrated analysis of 3D corneal shape average maps and topography parameters. A total of 7670 Orbscan II corneal topographies from 3835 consenting subjects with no history of ocular disease were studied. Average topography maps were created using the right and left corneal topographies of all subjects. To quantify symmetry, left eye topographies were flipped horizontally into "right eye" topographies and statistics maps were generated, including difference and intraclass correlation coefficient (ICC) maps. The standard deviation of the anterior and posterior average elevation maps in the 3-mm radius central zone of the right and left corneas ranged within ± 8 μm and ± 44 μm, respectively. The ICC maps showed almost perfect interocular agreement for anterior elevation, posterior elevation, and pachymetry (all ICCs > 0.96). All studied shape parameters also showed excellent agreement (ICCs ≥ 0.80). Mirror symmetry was not affected by age, sex, or spherical equivalent. We also showed that this horizontal reflection (flip) of the right and left corneal shapes could not be replaced by a simple rotation. These results indicate that in normal eyes, the anterior elevation, posterior elevation, and pachymetry of the right and left corneas show remarkable symmetry. This comprehensive analysis was achieved with the purpose of guiding the development of future biosynthetic corneal substitutes.

  16. Automated three-dimensional single cell phenotyping of spindle dynamics, cell shape, and volume

    CERN Document Server

    Plumb, Kemp; Pelletier, Vincent; Kilfoil, Maria L

    2015-01-01

    We present feature finding and tracking algorithms in 3D in living cells, and demonstrate their utility to measure metrics important in cell biological processes. We developed a computational imaging hybrid approach that combines automated three-dimensional tracking of point-like features with surface determination from which cell (or nuclear) volume, shape, and planes of interest can be extracted. After validation, we applied the technique to real space context-rich dynamics of the mitotic spindle, and cell volume and its relationship to spindle length, in dividing living cells. These methods are additionally useful for automated segregation of pre-anaphase and anaphase spindle populations in budding yeast. We found that genetic deletion of the yeast kinesin-5 mitotic motor cin8 leads to large mother and daughter cells that were indistinguishable based on size, and that in those cells the spindle length becomes uncorrelated with cell size. The technique can be used to visualize and quantify tracked feature c...

  17. Digital fringe projection system for large-volume 360-deg shape measurement

    Science.gov (United States)

    Sitnik, Robert; Kujawinska, Malgorzata; Woznicki, Jerzy M.

    2002-02-01

    We present a system for 3-D shape measurement in large volumes based on combined digital-fringe--Gray-code projection. With the help of a new calibration procedure, the system provides accurate results despite its crossed-axis configuration and unknown aberrations of the digital light projector and CCD camera. Also, the separate clouds of points captured from different directions are automatically merged into the main cloud. The system delivers results in the form of (x,y,z) coordinates of the object points with additional (R,G,B) color information about their texture. Applicability of the system is proven by presenting sample results of measurements performed on complex objects. The uncertainty of the system was estimated at 10 -4 of the measurement volume.

  18. Ecomorphological variation in shell shape of the freshwater turtle Pseudemys concinna inhabiting different aquatic flow regimes.

    Science.gov (United States)

    Rivera, Gabriel

    2008-12-01

    Populations of species that inhabit a range of environments frequently display divergent morphologies that correlate with differences in ecological parameters. The velocity of water flow (i.e., flow velocity) is a critical feature of aquatic environments that has been shown to influence morphology in a broad range of taxa. The focus of this study was to evaluate the relationship between flow velocity and shell morphology for males and females of the semi-aquatic freshwater turtle Pseudemys concinna. For both sexes, the carapace and plastron show significant morphological differences between habitats characterized by slow-flowing (i.e., lentic) and fast-flowing (i.e., lotic) water. In general, the most prominent pattern for both sexes is that the shells of individuals from lotic habitats are more streamlined (small height-to-length ratio) than the shells of individuals from lentic habitats. Of the two shell components (carapace and plastron), the carapace shows greater divergence between habitats, particularly for males. These results are consistent with adaptations to flow velocity, and suggest that variation in shape may be more constrained in females. I also provide empirical evidence for an adaptive benefit of the observed shape change (i.e., drag reduction) and a brief comment on the relative roles of genetic divergence and phenotypic plasticity in generating shape differences observed in this species.

  19. Two developmental modules establish 3D beak-shape variation in Darwin's finches

    Science.gov (United States)

    Mallarino, Ricardo; Grant, Peter R.; Grant, B. Rosemary; Kuo, Winston P.; Abzhanov, Arhat

    2011-01-01

    Bird beaks display tremendous variation in shape and size, which is closely associated with the exploitation of multiple ecological niches and likely played a key role in the diversification of thousands of avian species. Previous studies have demonstrated some of the molecular mechanisms that regulate morphogenesis of the prenasal cartilage, which forms the initial beak skeleton. However, much of the beak diversity in birds depends on variation in the premaxillary bone. It forms later in development and becomes the most prominent functional and structural component of the adult upper beak/jaw, yet its regulation is unknown. Here, we studied a group of Darwin's finch species with different beak shapes. We found that TGFβIIr, β-catenin, and Dickkopf-3, the top candidate genes from a cDNA microarray screen, are differentially expressed in the developing premaxillary bone of embryos of species with different beak shapes. Furthermore, our functional experiments demonstrate that these molecules form a regulatory network governing the morphology of the premaxillary bone, which differs from the network controlling the prenasal cartilage, but has the same species-specific domains of expression. These results offer potential mechanisms that may explain how the tightly coupled depth and width dimensions can evolve independently. The two-module program of development involving independent regulating molecules offers unique insights into how different developmental pathways may be modified and combined to induce multidimensional shifts in beak morphology. Similar modularity in development may characterize complex traits in other organisms to a greater extent than is currently appreciated. PMID:21368127

  20. Target volume delineation variation in radiotherapy for early stage rectal cancer in the Netherlands.

    Science.gov (United States)

    Nijkamp, Jasper; de Haas-Kock, Danielle F M; Beukema, Jannet C; Neelis, Karen J; Woutersen, Dankert; Ceha, Heleen; Rozema, Tom; Slot, Annerie; Vos-Westerman, Hanneke; Intven, Martijn; Spruit, Patty H; van der Linden, Yvette; Geijsen, Debby; Verschueren, Karijn; van Herk, Marcel B; Marijnen, Corrie A M

    2012-01-01

    The aim of this study was to measure and improve the quality of target volume delineation by means of national consensus on target volume definition in early-stage rectal cancer. The CTV's for eight patients were delineated by 11 radiation oncologists in 10 institutes according to local guidelines (phase 1). After observer variation analysis a workshop was organized to establish delineation guidelines and a digital atlas, with which the same observers re-delineated the dataset (phase 2). Variation in volume, most caudal and cranial slice and local surface distance variation were analyzed. The average delineated CTV volume decreased from 620 to 460 cc (p<0.001) in phase 2. Variation in the caudal CTV border was reduced significantly from 1.8 to 1.2 cm SD (p=0.01), while it remained 0.7 cm SD for the cranial border. The local surface distance variation (cm SD) reduced from 1.02 to 0.74 for anterior, 0.63 to 0.54 for lateral, 0.33 to 0.25 for posterior and 1.22 to 0.46 for the sphincter region, respectively. The large variation in target volume delineation could significantly be reduced by use of consensus guidelines and a digital delineation atlas. Despite the significant reduction there is still a need for further improvement. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  1. Can a central blood volume deficit be detected by systolic pressure variation during spontaneous breathing?

    DEFF Research Database (Denmark)

    Dahl, Michael; Hayes, Chris; Steen Rasmussen, Bodil

    2016-01-01

    BACKGROUND: Whether during spontaneous breathing arterial pressure variations (APV) can detect a volume deficit is not established. We hypothesized that amplification of intra-thoracic pressure oscillations by breathing through resistors would enhance APV to allow identification of a reduced...... resistors. A brachial arterial catheter was used to measure blood pressure and thus systolic pressure variation (SPV), pulse pressure variation and stroke volume variation . Pulse contour analysis determined stroke volume (SV) and CO and we evaluated whether APV could detect a 10 % decrease in CO. RESULTS...... (from 21 (±15)% to 30 (±13)%). Yet during head-up tilt, a SPV ≥ 37 % predicted a decrease in CO ≥ 10 % with a sensitivity and specificity of 78 % and 100 %, respectively. CONCLUSION: In spontaneously breathing healthy volunteers combined inspiratory and expiratory resistors enhance SPV during head...

  2. Biomechanical implications of intraspecific shape variation in chimpanzee crania: moving towards an integration of geometric morphometrics and finite element analysis

    Science.gov (United States)

    Smith, Amanda L.; Benazzi, Stefano; Ledogar, Justin A.; Tamvada, Kelli; Smith, Leslie C. Pryor; Weber, Gerhard W.; Spencer, Mark A.; Dechow, Paul C.; Grosse, Ian R.; Ross, Callum F.; Richmond, Brian G.; Wright, Barth W.; Wang, Qian; Byron, Craig; Slice, Dennis E.; Strait, David S.

    2014-01-01

    In a broad range of evolutionary studies, an understanding of intraspecific variation is needed in order to contextualize and interpret the meaning of variation between species. However, mechanical analyses of primate crania using experimental or modeling methods typically encounter logistical constraints that force them to rely on data gathered from only one or a few individuals. This results in a lack of knowledge concerning the mechanical significance of intraspecific shape variation that limits our ability to infer the significance of interspecific differences. This study uses geometric morphometric methods (GM) and finite element analysis (FEA) to examine the biomechanical implications of shape variation in chimpanzee crania, thereby providing a comparative context in which to interpret shape-related mechanical variation between hominin species. Six finite element models (FEMs) of chimpanzee crania were constructed from CT scans following shape-space Principal Component Analysis (PCA) of a matrix of 709 Procrustes coordinates (digitized onto 21 specimens) to identify the individuals at the extremes of the first three principal components. The FEMs were assigned the material properties of bone and were loaded and constrained to simulate maximal bites on the P3 and M2. Resulting strains indicate that intraspecific cranial variation in morphology is associated with quantitatively high levels of variation in strain magnitudes, but qualitatively little variation in the distribution of strain concentrations. Thus, interspecific comparisons should include considerations of the spatial patterning of strains rather than focus only their magnitude. PMID:25529239

  3. Shape variation in the skull and lower carnassial in a wild population of raccoon dog (Nyctereutes procyonoides).

    Science.gov (United States)

    Asahara, Masakazu

    2013-03-01

    Individual variations in skull and lower carnassial morphology within a wild population of raccoon dog were examined using geometric morphometric techniques. We compared individual morphological variations by using relative warp analysis, and then tested morphological integration between the skull and carnassial by using partial least square (PLS) analysis. The most marked variation in skull shape was the dorsoventral flexion; i.e., deformation from klinorhynchy to airorhynchy. Two remarkable variations were observed, including tilting between the trigonid (or carnassial blade) and the talonid in the lower carnassial, and the relative sizes of the trigonid and the talonid. This observed variation in skull shape was similar to previous reports of variations among dog breeds that correlate with a polymorphism of the Runx2 gene. This polymorphism has also been reported to correlate with snout length, which is strongly related to carnivorous or omnivorous dietary adaptations, across the entire order Carnivora. Our results in the lower carnassial were also similar to previously reported patterns observed for carnivorous or omnivorous dietary adaptations among Carnivora. However, in our PLS analysis between skull and carnassial shapes, we only found a significant correlation in a lower dimension, suggesting a lower degree of integration. These results indicate that shape variations, which could be sources of natural selection in the skull and carnassial, were present in a wild population, suggesting high evolvability of these variations in the raccoon dog and the order Carnivora in general.

  4. Stroke volume variation compared with pulse pressure variation and cardiac index changes for prediction of fluid responsiveness in mechanically ventilated patients

    Directory of Open Access Journals (Sweden)

    Randa Aly Soliman

    2015-04-01

    Conclusions: Baseline stroke volume variation ⩾8.15% predicted fluid responsiveness in mechanically ventilated patients with acute circulatory failure. The study also confirmed the ability of pulse pressure variation to predict fluid responsiveness.

  5. Regional Cellular Environment Shapes Phenotypic Variations of Hippocampal and Neocortical Chandelier Cells.

    Science.gov (United States)

    Ishino, Yugo; Yetman, Michael J; Sossi, Serena M; Steinecke, André; Hayano, Yasufumi; Taniguchi, Hiroki

    2017-10-11

    Different cortical regions processing distinct information, such as the hippocampus and the neocortex, share common cellular components and circuit motifs but form unique networks by modifying these cardinal units. Cortical circuits include diverse types of GABAergic interneurons (INs) that shape activity of excitatory principal neurons (PNs). Canonical IN types conserved across distinct cortical regions have been defined by their morphological, electrophysiological, and neurochemical properties. However, it remains largely unknown whether canonical IN types undergo specific modifications in distinct cortical regions and display "regional variants." It is also poorly understood whether such phenotypic variations are shaped by early specification or regional cellular environment. The chandelier cell (ChC) is a highly stereotyped IN type that innervates axon initial segments of PNs and thus serves as a good model with which to address this issue. Here, we show that Cadherin-6 (Cdh6), a homophilic cell adhesion molecule, is a reliable marker of ChCs and Cdh6-CreER mice (both sexes) provide genetic access to hippocampal ChCs (h-ChCs). We demonstrate that, compared with neocortical ChCs (nc-ChCs), h-ChCs cover twice as much area and innervate twice as many PNs. Interestingly, a subclass of h-ChCs exhibits calretinin (CR) expression, which is not found in nc-ChCs. Furthermore, we find that h-ChCs appear to be born earlier than nc-ChCs. Surprisingly, despite the difference in temporal origins, ChCs display host-region-dependent axonal/synaptic organization and CR expression when transplanted heterotopically. These results suggest that local cellular environment plays a critical role in shaping terminal phenotypes of regional IN variants in the hippocampus and the neocortex. SIGNIFICANCE STATEMENT Canonical interneuron (IN) types conserved across distinct cortical regions such as the hippocampus and the neocortex are defined by morphology, physiology, and gene expression

  6. Local and latitudinal variation in abundance: the mechanisms shaping the distribution of an ecosystem engineer.

    Science.gov (United States)

    Crutsinger, Gregory M; Gonzalez, Angélica L; Crawford, Kerri M; Sanders, Nathan J

    2013-01-01

    Ecological processes that determine the abundance of species within ecological communities vary across space and time. These scale-dependent processes are especially important when they affect key members of a community, such as ecosystem engineers that create shelter and food resources for other species. Yet, few studies have examined the suite of processes that shape the abundance of ecosystem engineers. Here, we evaluated the relative influence of temporal variation, local processes, and latitude on the abundance of an engineering insect-a rosette-galling midge, Rhopalomyia solidaginis (Diptera: Cecidomyiidae). Over a period of 3-5 years, we studied the density and size of galls across a suite of local experiments that manipulated genetic variation, soil nutrient availability, and the removal of other insects from the host plant, Solidago altissima (tall goldenrod). We also surveyed gall density within a single growing season across a 2,300 km latitudinal transect of goldenrod populations in the eastern United States. At the local scale, we found that host-plant genotypic variation was the best predictor of rosette gall density and size within a single year. We found that the removal of other insect herbivores resulted in an increase in gall density and size. The amendment of soil nutrients for four years had no effect on gall density, but galls were smaller in carbon-added plots compared to control and nitrogen additions. Finally, we observed that gall density varied several fold across years. At the biogeographic scale, we observed that the density of rosette gallers peaked at mid-latitudes. Using meta-analytic approaches, we found that the effect size of time, followed by host-plant genetic variation and latitude were the best predictors of gall density. Taken together, our study provides a unique comparison of multiple factors across different spatial and temporal scales that govern engineering insect herbivore density.

  7. Local and latitudinal variation in abundance: the mechanisms shaping the distribution of an ecosystem engineer

    Directory of Open Access Journals (Sweden)

    Gregory M. Crutsinger

    2013-07-01

    Full Text Available Ecological processes that determine the abundance of species within ecological communities vary across space and time. These scale-dependent processes are especially important when they affect key members of a community, such as ecosystem engineers that create shelter and food resources for other species. Yet, few studies have examined the suite of processes that shape the abundance of ecosystem engineers. Here, we evaluated the relative influence of temporal variation, local processes, and latitude on the abundance of an engineering insect—a rosette-galling midge, Rhopalomyia solidaginis (Diptera: Cecidomyiidae. Over a period of 3–5 years, we studied the density and size of galls across a suite of local experiments that manipulated genetic variation, soil nutrient availability, and the removal of other insects from the host plant, Solidago altissima (tall goldenrod. We also surveyed gall density within a single growing season across a 2,300 km latitudinal transect of goldenrod populations in the eastern United States. At the local scale, we found that host-plant genotypic variation was the best predictor of rosette gall density and size within a single year. We found that the removal of other insect herbivores resulted in an increase in gall density and size. The amendment of soil nutrients for four years had no effect on gall density, but galls were smaller in carbon-added plots compared to control and nitrogen additions. Finally, we observed that gall density varied several fold across years. At the biogeographic scale, we observed that the density of rosette gallers peaked at mid-latitudes. Using meta-analytic approaches, we found that the effect size of time, followed by host-plant genetic variation and latitude were the best predictors of gall density. Taken together, our study provides a unique comparison of multiple factors across different spatial and temporal scales that govern engineering insect herbivore density.

  8. Arc-shaped slit effect of EUV lithography with anamorphic high-NA system in terms of critical dimension variation

    Science.gov (United States)

    Kim, In-Seon; Kim, Guk-Jin; Yeung, Michael; Barouch, Eytan; Oh, Hye-Keun

    2017-03-01

    EUV lithography is one of the promising technologies for 1X nm patterning. EUV lithography has high resolution capability because of short wavelength of source but it has some particular patterning problems which are not appeared a t optical lithography. Owing to reflective optics, EUV light incidents obliquely in mask and oblique incidence of EUV lithography leads shadow effect and arc-shaped exposure slit. The study of these particular optical problems are required for optical proximity correction (OPC). Arc-shaped exposure slit leads azimuthal angle variation, incident angle variation , and variation of shadow width. With these variations along exposure slit, patterning result is varied along the exposure slit. With understanding of these particular optical problems, lots of EUV OPC studies have been presented with 0.33 conventional NA system. However, suggested anamorphic high NA system has not only elliptical shaped mask NA and also different angle distribution. The incident angle variation as a function of azimuthal angle is different between isomorphic and anamorphic NA systems. In case of anamorphic NA system, incident angle distribution is decreased on horizontal direction but it is larger on vertical direction compared with case of isomorphic NA system. These differences make different arc-shaped slit effect. CD variation as a function of azimuthal angle is different between isomorphic and a namorphic NA systems. The study of CD variation along the exposure slit is very helpful for OPC in EUV lithography.

  9. Image-guided radiotherapy of bladder cancer: bladder volume variation and its relation to margins

    DEFF Research Database (Denmark)

    Muren, Ludvig; Redpath, Anthony Thomas; Lord, Hannah

    2007-01-01

    BACKGROUND AND PURPOSE: To control and account for bladder motion is a major challenge in radiotherapy (RT) of bladder cancer. This study investigates the relation between bladder volume variation and margins in conformal and image-guided RT (IGRT) for this disease. MATERIALS AND METHODS: The cor......BACKGROUND AND PURPOSE: To control and account for bladder motion is a major challenge in radiotherapy (RT) of bladder cancer. This study investigates the relation between bladder volume variation and margins in conformal and image-guided RT (IGRT) for this disease. MATERIALS AND METHODS......: The correlation between the relative bladder volume (RBV, defined as repeat scan volume/planning scan volume) and the margins required to account for internal motion was first studied using a series of 20 bladder cancer patients with weekly repeat CT scanning during treatment. Both conformal RT (CRT) and IGRT...... were simulated; in the latter translational movement of the bladder was accounted for by isocentre shifting. Further analysis of bladder volumes and margins was performed using a second series of eight patients with twice-weekly repeat CT scanning. In an attempt to control bladder volume variation...

  10. Hominid mandibular corpus shape variation and its utility for recognizing species diversity within fossil Homo.

    Science.gov (United States)

    Lague, Michael R; Collard, Nicole J; Richmond, Brian G; Wood, Bernard A

    2008-12-01

    Mandibular corpora are well represented in the hominin fossil record, yet few studies have rigorously assessed the utility of mandibular corpus morphology for species recognition, particularly with respect to the linear dimensions that are most commonly available. In this study, we explored the extent to which commonly preserved mandibular corpus morphology can be used to: (i) discriminate among extant hominid taxa and (ii) support species designations among fossil specimens assigned to the genus Homo. In the first part of the study, discriminant analysis was used to test for significant differences in mandibular corpus shape at different taxonomic levels (genus, species and subspecies) among extant hominid taxa (i.e. Homo, Pan, Gorilla, Pongo). In the second part of the study, we examined shape variation among fossil mandibles assigned to Homo (including H. habilis sensu stricto, H. rudolfensis, early African H. erectus/H. ergaster, late African H. erectus, Asian H. erectus, H. heidelbergensis, H. neanderthalensis and H. sapiens). A novel randomization procedure designed for small samples (and using group 'distinctness values') was used to determine whether shape variation among the fossils is consistent with conventional taxonomy (or alternatively, whether a priori taxonomic groupings are completely random with respect to mandibular morphology). The randomization of 'distinctness values' was also used on the extant samples to assess the ability of the test to recognize known taxa. The discriminant analysis results demonstrated that, even for a relatively modest set of traditional mandibular corpus measurements, we can detect significant differences among extant hominids at the genus and species levels, and, in some cases, also at the subspecies level. Although the randomization of 'distinctness values' test is more conservative than discriminant analysis (based on comparisons with extant specimens), we were able to detect at least four distinct groups among the

  11. A Review on Anatomical Variations of Mental Foramen (Number, Location, Shape, Symmetry, Direction and Size

    Directory of Open Access Journals (Sweden)

    F Ezoddini-Ardakani

    2016-02-01

    Full Text Available Mental foramen is located on the anterior aspect of the mandible that permits the terminal branch of the inferior alveolar nerve and blood vessels to exit. The anatomical variations of mental foramen are of considerable importance in local anesthesia, treatment of the fractures in the parasymphysis area, orthognatic surgeries, implant placement, etc. Regarding the importance of mental foramen in dentistry (from local anesthesia to invasive surgical procedures, this study intends to review the anatomical variations of mental foramen in this study. Absence of mental foramen is rare. On the other hand, prevalence of accessory mental foramen has been estimated lower than 15% in the most studies. The position of mental foramen is normally between first and second premolar teeth or under second premolar tooth in different ethnic groups and bilateral symmetry exists in regard with location in most cases. In most studies, the ratio of distance from mental foramen to symphysis to distance from symphysis to posterior border of ramus has been reported about 1/3.5 to 1/3. Mental foramen is oval or circular in shape and its most common direction is usually posterosuperior. Its size in different studies has been estimated about 2 to 5 millimeters and asymmetry in size is possible on both sides of mandible. Due to variations of mental foramen between various ethnic groups and even different individuals in the same ethnic group, using advanced imaging techniques such as CBCT is recommended in order to gain detailed knowledge of anatomy and morphology of mental foramen before applying invasive surgeries.

  12. A shape memory alloy-actuated surgical instrument with compact volume.

    Science.gov (United States)

    Shi, Zhen Yun; Liu, Da; Wang, Tian Miao

    2014-12-01

    Surgical robotic systems have been proven to be accurate and dexterous during minimally invasive surgery (MIS). However, single incision laparoscopic surgery (SILS) requires more compact robotic arms with sufficient dexterity and output. A shape memory alloy (SMA)-actuated instrument was adopted to assist operations. The instrument fixed at the slave site had three degrees of freedom (DOFs) and was driven by SMA wires, pitch, yaw, and grip, with an 8 mm diameter; a passive hydraulic support mechanism was placed in vitro. In vitro, the maximum force, velocity and accuracy were proven to be sufficient for medical application. In an animal study, the system was inserted into the abdomen; three more generic constraints were tested: medical gesture, safety, and implementation. The robot was feasible and safe for multi-angle monitoring, grasping, and holding an organ. The SMA-actuated system was accurate and dexterous with minimal system volume. Copyright © 2013 John Wiley & Sons, Ltd.

  13. Influence of volume magnetostriction on the thermodynamic properties of Ni-Mn-Ga shape memory alloys

    Energy Technology Data Exchange (ETDEWEB)

    Kosogor, Anna [National University of Science and Technology “MISiS,” Moscow 119049 (Russian Federation); Institute of Magnetism, 36-b, Vernadsky Str., Kyiv 03142 (Ukraine); Donetsk Institute for Physics and Engineering, Kyiv 03028 (Ukraine); L' vov, Victor A. [Institute of Magnetism, 36-b, Vernadsky Str., Kyiv 03142 (Ukraine); Faculty of Radiophysics, Electronics and Computer Systems, Taras Shevchenko University, Glushkov Str. 4G, Kyiv 01601 (Ukraine); Departament de Fisica, Universitat de les Illes Balears, Ctra. de Valldemossa, km 7.5, 07122 Palma de Mallorca (Spain); Cesari, Eduard [Departament de Fisica, Universitat de les Illes Balears, Ctra. de Valldemossa, km 7.5, 07122 Palma de Mallorca (Spain)

    2015-10-07

    In the present article, the thermodynamic properties of Ni-Mn-Ga ferromagnetic shape memory alloys exhibiting the martensitic transformations (MTs) above and below Curie temperature are compared. It is shown that when MT goes below Curie temperature, the elastic and thermal properties of alloy noticeably depend on magnetization value due to spontaneous volume magnetostriction. However, the separation of magnetic parts from the basic characteristics of MT is a difficult task, because the volume magnetostriction does not qualitatively change the transformational behaviour of alloy. This problem is solved for several Ni-Mn-Ga alloys by means of the quantitative theoretical analysis of experimental data obtained in the course of stress-strain tests. For each alloy, the entropy change and the transformation heat evolved in the course of MT are evaluated, first, from the results of stress-strain tests and, second, from differential scanning calorimetry data. For all alloys, a quantitative agreement between the values obtained in two different ways is observed. It is shown that the magnetic part of transformation heat exceeds the non-magnetic one for the Ni-Mn-Ga alloys undergoing MTs in ferromagnetic state, while the elevated values of transformation heat measured for the alloys undergoing MTs in paramagnetic state are caused by large MT strains.

  14. Influence of respiratory rate on stroke volume variation in mechanically ventilated patients.

    Science.gov (United States)

    De Backer, Daniel; Taccone, Fabio Silvio; Holsten, Roland; Ibrahimi, Fayssal; Vincent, Jean-Louis

    2009-05-01

    Heart-lung interactions are used to evaluate fluid responsiveness in mechanically ventilated patients, but these indices may be influenced by ventilatory conditions. The authors evaluated the impact of respiratory rate (RR) on indices of fluid responsiveness in mechanically ventilated patients, hypothesizing that pulse pressure variation and respiratory variation in aortic flow would decrease at high RRs. In 17 hypovolemic patients, thermodilution cardiac output and indices of fluid responsiveness were measured at a low RR (14-16 breaths/min) and at the highest RR (30 or 40 breaths/min) achievable without altering tidal volume or inspiratory/expiratory ratio. An increase in RR was accompanied by a decrease in pulse pressure variation from 21% (18-31%) to 4% (0-6%) (P variation in aortic flow from 23% (18-28%) to 6% (5-8%) (P variations in superior vena cava diameter (caval index) were unaltered, i.e., from 38% (27-43%) to 32% (22-39%), P = not significant. Cardiac index was not affected by the changes in RR but did increase after fluids. Pulse pressure variation became negligible when the ratio between heart rate and RR decreased below 3.6. Respiratory variations in stroke volume and its derivates are affected by RR, but caval index was unaffected. This suggests that right and left indices of ventricular preload variation are dissociated. At high RRs, the ability to predict the response to fluids of stroke volume variations and its derivate may be limited, whereas caval index can still be used.

  15. Bladder volume variations of cervical cancer patient in radiation therapy using ultrasonography

    Energy Technology Data Exchange (ETDEWEB)

    Gong, Jong Ho [Dept. of Radiation Oncology, Pusan National University Hospital, Pusan (Korea, Republic of)

    2016-12-15

    The bladder volume change was measured using ultrasonography for helping decrease the side effects and other organ variations in the location of radiation therapy for cervical cancer patients. An experiment was performed targeting patients who were treated with radiation therapy at PNUH within the period from September to December 2015. To maintain the bladder volume, each patient was instructed to drink 500 cc water before and after CT simulation, 60 minutes before the dry run. Also, the bladder volume was measured in each patient CT scan, and a 3D conformal therapy plan was designed. The bladder volumes measured before and after the CT simulation, dry run, and radiation treatment planning were compared and analyzed. The average volume and average error of the bladder that were obtained from the measurement based on the CT scan images had the lowest standard deviation in the CT simulation. This means that the values that were obtained before and after the CT simulation were statistically relevant and correlative. Moreover, the bladder volume measured via ultrasonography was larger size, the average volume in the CT scan. But the values that were obtained Dry run and after the CT simulation were not statistically relevant. Drinking a certain amount of water helps a patient maintain his/her bladder volume for a dry run. Even then, it is difficult to maintain the bladder volume for the dry run. Also, whether or not the patients followed the directions for the dry run correctly is important.

  16. Environmental effects on the shape variation of male ultraviolet patterns in the Brimstone butterfly (Gonepteryx rhamni, Pieridae, Lepidoptera).

    Science.gov (United States)

    Pecháček, Pavel; Stella, David; Keil, Petr; Kleisner, Karel

    2014-12-01

    The males of the Brimstone butterfly (Gonepteryx rhamni) have ultraviolet pattern on the dorsal surfaces of their wings. Using geometric morphometrics, we have analysed correlations between environmental variables (climate, productivity) and shape variability of the ultraviolet pattern and the forewing in 110 male specimens of G. rhamni collected in the Palaearctic zone. To start with, we subjected the environmental variables to principal component analysis (PCA). The first PCA axis (precipitation, temperature, latitude) significantly correlated with shape variation of the ultraviolet patterns across the Palaearctic. Additionally, we have performed two-block partial least squares (PLS) analysis to assess co-variation between intraspecific shape variation and the variation of 11 environmental variables. The first PLS axis explained 93% of variability and represented the effect of precipitation, temperature and latitude. Along this axis, we observed a systematic increase in the relative area of ultraviolet colouration with increasing temperature and precipitation and decreasing latitude. We conclude that the shape variation of ultraviolet patterns on the forewings of male Brimstones is correlated with large-scale environmental factors.

  17. MRT letter: a total variation based method for 3D shape recovery of microscopic objects through image focus.

    Science.gov (United States)

    Mahmood, Muhammad Tariq

    2013-09-01

    Generally, shape from focus methods use a single focus measure to compute focus quality and to obtain an initial depth map of an object. However, different focus measures perform differently in diverse conditions. Therefore, it is hard to get accurate 3D shape based on a single focus measure. In this article, we propose a total variation based method for recovering 3D shape of an object by combining multiple depth hypothesis obtained through different focus measures. Improved performance of the proposed method is evaluated by conducting several experiments using images of synthetic and real microscopic objects. Comparative analysis demonstrates the effectiveness of the proposed approach. Copyright © 2013 Wiley Periodicals, Inc.

  18. Quantitative gene-gene and gene-environment mapping for leaf shape variation using tree-based models.

    Science.gov (United States)

    Fu, Guifang; Dai, Xiaotian; Symanzik, Jürgen; Bushman, Shaun

    2017-01-01

    Leaf shape traits have long been a focus of many disciplines, but the complex genetic and environmental interactive mechanisms regulating leaf shape variation have not yet been investigated in detail. The question of the respective roles of genes and environment and how they interact to modulate leaf shape is a thorny evolutionary problem, and sophisticated methodology is needed to address it. In this study, we investigated a framework-level approach that inputs shape image photographs and genetic and environmental data, and then outputs the relative importance ranks of all variables after integrating shape feature extraction, dimension reduction, and tree-based statistical models. The power of the proposed framework was confirmed by simulation and a Populus szechuanica var. tibetica data set. This new methodology resulted in the detection of novel shape characteristics, and also confirmed some previous findings. The quantitative modeling of a combination of polygenetic, plastic, epistatic, and gene-environment interactive effects, as investigated in this study, will improve the discernment of quantitative leaf shape characteristics, and the methods are ready to be applied to other leaf morphology data sets. Unlike the majority of approaches in the quantitative leaf shape literature, this framework-level approach is data-driven, without assuming any pre-known shape attributes, landmarks, or model structures. © 2016 The Authors. New Phytologist © 2016 New Phytologist Trust.

  19. Shape Variation in Neotropical Cytheridella (Ostracoda Using Semilandmarks-Based Geometric Morphometrics: A Methodological Approach and Possible Biogeographical Implications.

    Directory of Open Access Journals (Sweden)

    Claudia Wrozyna

    Full Text Available Geometric morphometrics offer effective methods to obtain information about shape and shape variability. In ostracodology, landmark-based methods are, however, not well established. To test the applicability of geometric morphometric analyses for ostracods, we investigated shape variation among recent and fossil populations of the genus Cytheridella using a combination of landmarks and semilandmarks. The study focuses on the species' intraspecific morphological variability on a supra-regional scale, comparing living populations from Florida, Yucatán, Colombia and Brazil. We performed Generalized least-squares Procrustes Analysis on 508 adult and juvenile specimens (valves including stages A-1 to A-4. The analyses show that the primary pattern in shape variation is ontogenetic allometry, supporting a clear separation of adults and juveniles. Shape changes are relatively small during ontogeny from A-4 to A-1. Greatest modification of valve shape occurs during the last molt phase. Insufficient differentiation of sexes is caused by females with less developed brood pouches. Disentangling size- and non-size-dependent shape changes reveals regional differences between populations of the species C. ilosvayi and supports its taxonomic distinction from a fossil relative (C. danielopoli. The distribution of regional morphotypes of C. ilosvayi in Florida, Mexico, and Brazil are congruent with fly ways of water birds.

  20. Hospital variation in 30-day mortality after colorectal cancer surgery in denmark: the contribution of hospital volume and patient characteristics

    DEFF Research Database (Denmark)

    Osler, Merete; Iversen, Lene Hjerrild; Borglykke, Anders

    2011-01-01

    This study examines variation between hospitals in 30-day mortality after surgery for colorectal cancer (CRC) in Denmark and explores whether hospital volume and patient characteristics contribute to any variation between hospitals.......This study examines variation between hospitals in 30-day mortality after surgery for colorectal cancer (CRC) in Denmark and explores whether hospital volume and patient characteristics contribute to any variation between hospitals....

  1. Automatized spleen segmentation in non-contrast-enhanced MR volume data using subject-specific shape priors

    Science.gov (United States)

    Gloger, Oliver; Tönnies, Klaus; Bülow, Robin; Völzke, Henry

    2017-07-01

    To develop the first fully automated 3D spleen segmentation framework derived from T1-weighted magnetic resonance (MR) imaging data and to verify its performance for spleen delineation and volumetry. This approach considers the issue of low contrast between spleen and adjacent tissue in non-contrast-enhanced MR images. Native T1-weighted MR volume data was performed on a 1.5 T MR system in an epidemiological study. We analyzed random subsamples of MR examinations without pathologies to develop and verify the spleen segmentation framework. The framework is modularized to include different kinds of prior knowledge into the segmentation pipeline. Classification by support vector machines differentiates between five different shape types in computed foreground probability maps and recognizes characteristic spleen regions in axial slices of MR volume data. A spleen-shape space generated by training produces subject-specific prior shape knowledge that is then incorporated into a final 3D level set segmentation method. Individually adapted shape-driven forces as well as image-driven forces resulting from refined foreground probability maps steer the level set successfully to the segment the spleen. The framework achieves promising segmentation results with mean Dice coefficients of nearly 0.91 and low volumetric mean errors of 6.3%. The presented spleen segmentation approach can delineate spleen tissue in native MR volume data. Several kinds of prior shape knowledge including subject-specific 3D prior shape knowledge can be used to guide segmentation processes achieving promising results.

  2. Effects of DARPP-32 Genetic Variation on Prefrontal Cortex Volume and Episodic Memory Performance.

    Science.gov (United States)

    Persson, Ninni; Persson, Jonas; Lavebratt, Catharina; Fischer, Håkan

    2017-01-01

    Despite evidence of a fundamental role of DARPP-32 in integrating dopamine and glutamate signaling, studies examining gene coding for DARPP-32 in relation to neural and behavioral correlates in humans are scarce. Post mortem findings suggest genotype specific expressions of DARPP-32 in the dorsal frontal lobes. Therefore, we investigated the effects of genomic variation in DARPP-32 coding on frontal lobe volumes and episodic memory. Volumetric data from the dorsolateral (DLPFC), and visual cortices (VC) were obtained from 61 younger and older adults (♀54%). The major homozygote G, T, or A genotypes in single nucleotide polymorphisms (SNPs: rs879606; rs907094; rs3764352, the two latter in complete linkage disequilibrium), at the DARPP-32 regulating PPP1R1B gene, influenced frontal gray matter volume and episodic memory (EM). Homozygous carriers of allelic variants with lower DARPP-32 expression had an overall larger prefrontal volume in addition to greater EM recall accuracy after accounting for the influence of age. The SNPs did not influence VC volume. The genetic effects on DLPFC were greater in young adults and selective to this group for EM. Our findings suggest that genomic variation maps onto individual differences in frontal brain volumes and cognitive functions. Larger DLPFC volumes were also related to better EM performance, suggesting that gene-related differences in frontal gray matter may contribute to individual differences in EM. These results need further replication from experimental and longitudinal reports to determine directions of causality.

  3. Effects of DARPP-32 Genetic Variation on Prefrontal Cortex Volume and Episodic Memory Performance

    Directory of Open Access Journals (Sweden)

    Ninni Persson

    2017-05-01

    Full Text Available Despite evidence of a fundamental role of DARPP-32 in integrating dopamine and glutamate signaling, studies examining gene coding for DARPP-32 in relation to neural and behavioral correlates in humans are scarce. Post mortem findings suggest genotype specific expressions of DARPP-32 in the dorsal frontal lobes. Therefore, we investigated the effects of genomic variation in DARPP-32 coding on frontal lobe volumes and episodic memory. Volumetric data from the dorsolateral (DLPFC, and visual cortices (VC were obtained from 61 younger and older adults (♀54%. The major homozygote G, T, or A genotypes in single nucleotide polymorphisms (SNPs: rs879606; rs907094; rs3764352, the two latter in complete linkage disequilibrium, at the DARPP-32 regulating PPP1R1B gene, influenced frontal gray matter volume and episodic memory (EM. Homozygous carriers of allelic variants with lower DARPP-32 expression had an overall larger prefrontal volume in addition to greater EM recall accuracy after accounting for the influence of age. The SNPs did not influence VC volume. The genetic effects on DLPFC were greater in young adults and selective to this group for EM. Our findings suggest that genomic variation maps onto individual differences in frontal brain volumes and cognitive functions. Larger DLPFC volumes were also related to better EM performance, suggesting that gene-related differences in frontal gray matter may contribute to individual differences in EM. These results need further replication from experimental and longitudinal reports to determine directions of causality.

  4. Ecology shapes birdsong evolution: variation in morphology and habitat explains variation in white-crowned sparrow song.

    Science.gov (United States)

    Derryberry, Elizabeth P

    2009-07-01

    Ecological variation appears to underlie the evolution of mating signals in many taxa, yet understanding of how this process occurs over time is limited. Here, I investigate whether changes over time in a well-studied mating signal-birdsong-are attributable to ecological factors that affect signal production and transmission. Variation in the acoustic properties of songs is thought to be affected by the mechanics of sound production as well as by features of the habitat that affect sound transmission. To determine whether these mechanisms contribute to song variation, I compare patterns of morphological and habitat variation with variation in song structure among populations of white-crowned sparrows (Zonotrichia leucophrys) at two time points separated by 35 years. Among contemporary (2005) populations, vegetation density and bill size explain significant variation in song structure. The direction of change in song structure between 1970 and 2005 is also consistent with the direction of change in vegetation density. These findings suggest that variation in factors that affect signal production and transmission explains significant variation in white-crowned sparrow song.

  5. Patterns of fluctuating asymmetry and shape variation in Chironomus riparius (Diptera, Chironomidae exposed to nonylphenol or lead.

    Directory of Open Access Journals (Sweden)

    Hélène Arambourou

    Full Text Available Deformities and fluctuating asymmetry in chironomid larvae have been proposed as sensitive indicators of biological stress and are commonly used to assess the ecological impact of human activities. In particular, they have been associated in Chironomus riparius, the most commonly used species, with heavy metal and pesticide river pollution. In this study, the effect of lead and 4-nonylphenol on mouthpart morphological variation of Chironomus riparius larvae was investigated by traditional and geometric morphometrics. For this purpose, first to fourth instar larvae were exposed to sediment spiked with lead (from 3.0 to 456.9 mg/kg dry weight or 4-NP (from 0.1 to 198.8 mg/kg dry weight. Mentum phenotypic response to pollutants was assessed by four parameters: (1 the frequency of deformities, (2 fluctuating asymmetry of mentum length, (3 fluctuating asymmetry of mentum shape and (4 the mentum mean shape changes. Despite the bioaccumulation of pollutants in the chironomid's body, no significant differences between control and stressed groups were found for mouthpart deformities and fluctuating asymmetry of mentum length. Slight effects on mentum shape fluctuating asymmetry were observed for two stressed groups. Significant mean shape changes, consisting of tooth size increase and tooth closing, were detected for lead and 4-NP exposure respectively. Those variations, however, were negligible in comparison to mentum shape changes due to genetic effects. These results suggest that the use of mentum variation as an indicator of toxic stress in Chironomus riparius should be considered cautiously.

  6. Patterns of Fluctuating Asymmetry and Shape Variation in Chironomus riparius (Diptera, Chironomidae) Exposed to Nonylphenol or Lead

    Science.gov (United States)

    Arambourou, Hélène; Beisel, Jean-Nicolas; Branchu, Philippe; Debat, Vincent

    2012-01-01

    Deformities and fluctuating asymmetry in chironomid larvae have been proposed as sensitive indicators of biological stress and are commonly used to assess the ecological impact of human activities. In particular, they have been associated in Chironomus riparius, the most commonly used species, with heavy metal and pesticide river pollution. In this study, the effect of lead and 4-nonylphenol on mouthpart morphological variation of Chironomus riparius larvae was investigated by traditional and geometric morphometrics. For this purpose, first to fourth instar larvae were exposed to sediment spiked with lead (from 3.0 to 456.9 mg/kg dry weight) or 4-NP (from 0.1 to 198.8 mg/kg dry weight). Mentum phenotypic response to pollutants was assessed by four parameters: (1) the frequency of deformities, (2) fluctuating asymmetry of mentum length, (3) fluctuating asymmetry of mentum shape and (4) the mentum mean shape changes. Despite the bioaccumulation of pollutants in the chironomid’s body, no significant differences between control and stressed groups were found for mouthpart deformities and fluctuating asymmetry of mentum length. Slight effects on mentum shape fluctuating asymmetry were observed for two stressed groups. Significant mean shape changes, consisting of tooth size increase and tooth closing, were detected for lead and 4-NP exposure respectively. Those variations, however, were negligible in comparison to mentum shape changes due to genetic effects. These results suggest that the use of mentum variation as an indicator of toxic stress in Chironomus riparius should be considered cautiously. PMID:23133660

  7. Competition for hummingbird pollination shapes flower color variation in Andean solanaceae.

    Science.gov (United States)

    Muchhala, Nathan; Johnsen, Sönke; Smith, Stacey Dewitt

    2014-08-01

    One classic explanation for the remarkable diversity of flower colors across angiosperms involves evolutionary shifts among different types of pollinators with different color preferences. However, the pollinator shift model fails to account for the many examples of color variation within clades that share the same pollination system. An alternate explanation is the competition model, which suggests that color divergence evolves in response to interspecific competition for pollinators, as a means to decrease interspecific pollinator movements. This model predicts color overdispersion within communities relative to null assemblages. Here, we combine morphometric analyses, field surveys, and models of pollinator vision with a species-level phylogeny to test the competition model in the primarily hummingbird-pollinated clade Iochrominae (Solanaceae). Results show that flower color as perceived by pollinators is significantly overdispersed within sites. This pattern is not simply due to phylogenetic history: phylogenetic community structure does not deviate from random expectations, and flower color lacks phylogenetic signal. Moreover, taxa that occur in sympatry occupy a significantly larger volume of color space than those in allopatry, supporting the hypothesis that competition in sympatry drove the evolution of novel colors. We suggest that competition among close relatives may commonly underlie floral divergence, especially in species-rich habitats where congeners frequently co-occur. © 2014 The Author(s). Evolution © 2014 The Society for the Study of Evolution.

  8. Heart Performance Determination by Visualization in Larval Fishes: Influence of Alternative Models for Heart Shape and Volume

    Directory of Open Access Journals (Sweden)

    Prescilla Perrichon

    2017-07-01

    Full Text Available Understanding cardiac function in developing larval fishes is crucial for assessing their physiological condition and overall health. Cardiac output measurements in transparent fish larvae and other vertebrates have long been made by analyzing videos of the beating heart, and modeling this structure using a conventional simple prolate spheroid shape model. However, the larval fish heart changes shape during early development and subsequent maturation, but no consideration has been made of the effect of different heart geometries on cardiac output estimation. The present study assessed the validity of three different heart models (the “standard” prolate spheroid model as well as a cylinder and cone tip + cylinder model applied to digital images of complete cardiac cycles in larval mahi-mahi and red drum. The inherent error of each model was determined to allow for more precise calculation of stroke volume and cardiac output. The conventional prolate spheroid and cone tip + cylinder models yielded significantly different stroke volume values at 56 hpf in red drum and from 56 to 104 hpf in mahi. End-diastolic and stroke volumes modeled by just a simple cylinder shape were 30–50% higher compared to the conventional prolate spheroid. However, when these values of stroke volume multiplied by heart rate to calculate cardiac output, no significant differences between models emerged because of considerable variability in heart rate. Essentially, the conventional prolate spheroid shape model provides the simplest measurement with lowest variability of stroke volume and cardiac output. However, assessment of heart function—especially if stroke volume is the focus of the study—should consider larval heart shape, with different models being applied on a species-by-species and developmental stage-by-stage basis for best estimation of cardiac output.

  9. Describing shell shape variations and sexual dimorphism of Golden Apple Snail, Pomacea caniculata (Lamarck, 1822 using geometric morphometric analysis

    Directory of Open Access Journals (Sweden)

    C.C. Cabuga

    2017-09-01

    Full Text Available Pomacea caniculata or Golden Apple Snail (GAS existed to be a rice pest in the Philippines and in Asia. Likewise, geographic location also contributes its increasing populations thus making it invasive among freshwater habitats and rice field areas. This study was conducted in order to describe shell shape variations and sexual dimorphism among the populations of P. caniculata. A total of 180 were randomly collected in the three lakes of Esperanza, Agusan del Sur (Lake Dakong Napo, Lake Oro, and Lake Cebulan, of which each lake comprised of 60 samples (30 males and 30 females. To determine the variations and sexual dimorphism in the shell shape of golden apple snail, coordinates was administered to relative warp analysis and the resulting data were subjected to Multivariate Analysis of Variance (MANOVA, Principal Component Analysis (PCA and Canonical Variate Analysis (CVA. The results show statistically significant (P<0.05 from the appended male and female dorsal and ventral/apertural portion. While male and female spire height, body size, and shell shape opening also shows significant variations. These phenotypic distinctions could be associated with geographic isolation, predation and nutrient component of the gastropods. Thus, the importance of using geometric morphometric advances in describing sexual dimorphism in the shell shape of P. caniculata.

  10. Evaluation of various Deformable Image Registrations for Point and Volume Variations

    CERN Document Server

    Han, Su Chul; Park, Seungwoo; Lee, Soon Sung; Jung, Haijo; Kim, Mi-Sook; Yoo, Hyung Jun; Ji, Young Hoon; Yi, Chul Young; Kim, Kum Bae

    2015-01-01

    The accuracy of deformable image registration (DIR) has a significant dosimetric impact in radiation treatment planning. We evaluated accuracy of various DIR algorithms using variations of the deformation point and volume. The reference image (Iref) and volume (Vref) was first generated with virtual deformation QA software (ImSimQA, Oncology System Limited, UK). We deformed Iref with axial movement of deformation point and Vref depending on the types of deformation that are the deformation1 is to increase the Vref (relaxation) and the deformation 2 is to decrease . The deformed image (Idef) and volume (Vdef) acquired by ImSimQA software were inversely deformed to Iref and Vref using DIR algorithms. As a result, we acquired deformed image (Iid) from Idef and volume (Vid) from Vdef. The DIR algorithms were the Horn Schunk optical flow (HS), Iterative Optical Flow (IOF), Modified Demons (MD) and Fast Demons (FD) with the Deformable Image Registration and Adaptive Radiotherapy Toolkit (DIRART) of MATLAB. The imag...

  11. Revisiting the returns-volume relationship: Time variation, alternative measures and the financial crisis

    Science.gov (United States)

    Cook, Steve; Watson, Duncan

    2017-03-01

    Following its introduction in the seminal study of Osborne (1959), a voluminous literature has emerged examining the returns-volume relationship for financial assets. The present paper revisits this relationship in an examination of the FTSE100 which extends the existing literature in two ways. First, alternative daily measures of the FTSE100 index are used to create differing returns and absolute returns series to employ in an examination of returns-volume causality. Second, rolling regression analysis is utilised to explore potential time variation in the returns-volume relationship. The findings obtained depict a hitherto unconsidered complexity in this relationship with the type of returns series considered and financial crisis found to be significant underlying factors. The implications of the newly derived results for both the understanding of the nature of the returns-volume relationship and the development of theories in connection to it are discussed.

  12. Pulse pressure variation does not reflect stroke volume variation in mechanically ventilated rats with lipopolysaccharide-induced pneumonia.

    Science.gov (United States)

    Cherpanath, Thomas G V; Smeding, Lonneke; Lagrand, Wim K; Hirsch, Alexander; Schultz, Marcus J; Groeneveld, Johan A B

    2014-01-01

    1. The present study examined the relationship between centrally measured stroke volume variation (SVV) and peripherally derived pulse pressure variation (PPV) in the setting of increased total arterial compliance (CA rt ). 2. Ten male Wistar rats were anaesthetized, paralysed and mechanically ventilated before being randomized to receive intrapulmonary lipopolysaccharide (LPS) or no LPS. Pulse pressure (PP) was derived from the left carotid artery, whereas stroke volume (SV) was measured directly in the left ventricle. Values of SVV and PPV were calculated over three breaths. Balloon inflation of a catheter positioned in the inferior vena cava was used, for a maximum of 30 s, to decrease preload while the SVV and PPV measurements were repeated. Values of CA rt were calculated as SV/PP. 3. Intrapulmonary LPS increased CA rt and SV. Values of SVV and PPV increased in both LPS-treated and untreated rats during balloon inflation. There was a correlation between SVV and PPV in untreated rats before (r = 0.55; P = 0.005) and during (r = 0.69; P mechanically ventilated rats. Our data caution against their interchangeability in human sepsis. © 2013 Wiley Publishing Asia Pty Ltd.

  13. Variation of ventilation practices with center volume after pediatric heart surgery.

    Science.gov (United States)

    Gupta, Punkaj; Tang, Xinyu; Gossett, Jeffrey M; Gall, Christine M; Lauer, Casey; Rice, Tom B; Wetzel, Randall C

    2015-03-01

    This study was designed to evaluate the odds of mechanical ventilation and duration of mechanical ventilation after pediatric cardiac surgery across centers of varying center volume using the Virtual PICU Systems database. Children receiving cardiac surgery at high-volume centers will be associated with lower odds of mechanical ventilation and shorter duration of mechanical ventilation, compared with low-volume centers. Patients age mechanical ventilation and duration of mechanical ventilation, respectively, to investigate the difference in the outcomes between different center volume groups with/without adjustment for other risk factors. A total of 10 378 patients from 43 centers qualified for inclusion. Of these, 7648 (74%) patients received conventional mechanical ventilation after cardiac surgery. Higher center volume was significantly associated with lower odds of mechanical ventilation after cardiac surgery (odds ratio: 2.68, 95% confidence interval: 2.15-3.35). However, patients receiving mechanical ventilation in these centers were associated with longer duration of mechanical ventilation, compared with lower-volume centers (hazard ratio: 1.26, 95% confidence interval: 1.16-1.37). This association was most prominent in the lower surgical-risk categories. Large clinical practice variations were demonstrated for mechanical ventilation following pediatric cardiac surgery among intensive care units of varied center volumes. © 2015 Wiley Periodicals, Inc.

  14. Geometric morphometrics of functionally distinct floral organs in Iris pumila: Analyzing patterns of symmetric and asymmetric shape variations

    Directory of Open Access Journals (Sweden)

    Radović Sanja

    2017-01-01

    Full Text Available The Iris flower is a complex morphological structure composed of two trimerous whorls of functionally distinct petaloid organs (the falls and the standards, one whorl of the stamens and one tricarpellary gynoecium. The petal-like style arms of the carpels are banded over the basal part of the falls, forming three pollination tunnels, each of which is perceived by the Iris pollinators as a single bilaterally symmetrical flower. Apart from the stamens, all petaloid floral organs are preferentially involved in advertising rewards to potential pollinators. Here we used the methods of geometric morphometrics to explore the shape variation in falls, standards and style arms of the Iris pumila flowers and to disentangle the symmetric and the asymmetric component of the total shape variance. Our results show that symmetric variation contributes mostly to the total shape variance in each of the three floral organs. Fluctuating asymmetry (FA was the dominant component of the asymmetric shape variation in the falls and the standards, but appeared to be marginally significant in the style arms. The values of FA indexes for the shape of falls (insects’ landing platforms and for the shape of standards (long-distance reward signals were found to be two orders of magnitude greater compared to that of the style arms. Directional asymmetry appeared to be very low, but highly statistically significant for all analyzed floral organs. Because floral symmetry can reliably indicate the presence of floral rewards, an almost perfect symmetry recorded for the style arm shape might be the outcome of pollinator preferences for symmetrical pollination units. [Project of the Serbian Ministry of Education, Science and Technological Development, Grant no. 173007

  15. Menstrual variation of breast volume and T{sub 2} relaxation times in cyclical mastalgia

    Energy Technology Data Exchange (ETDEWEB)

    Hussain, Zainab [Department of Medical Imaging, University of Liverpool, Johnstone Building, Brownlow Hill, P.O. Box 147, Liverpool, Merseyside L69 3GB (United Kingdom); Magnetic Resonance and Image Analysis Research Centre, University of Liverpool, Johnstone Building, Brownlow Hill, P.O. Box 147, Liverpool, Merseyside L69 3GB (United Kingdom)], E-mail: zay@liverpool.ac.uk; Brooks, Jonathan [Magnetic Resonance and Image Analysis Research Centre, University of Liverpool, Johnstone Building, Brownlow Hill, P.O. Box 147, Liverpool, Merseyside L69 3GB (United Kingdom); Department of Human Anatomy and Genetics, University of Oxford, Oxford (United Kingdom); Percy, Dave [Centre for Operational Research and Applied Statistics, University of Salford, Salford, Greater Manchester M5 4WT (United Kingdom)

    2008-02-15

    Purpose: Hormonal activity causes breast volume to change during the menstrual cycle. One possible cause of this volume change is thought to be due to water retention or oedema within the tissues. We used magnetic resonance imaging (MRI) to study the variation in breast volume and {sup 1}H Magnetic Resonance Spectroscopy (MRS) to measure T{sub 2} relaxation times which are known to increase with increasing tissue water content. We hypothesised that an increase in breast volume will elevate T{sub 2} relaxation due to the presence of an increased water content within the breast. T{sub 2} Relaxation time and volume were studied in fifteen control subjects and in a cohort of eight patients with cyclical mastalgia in order to determine whether changes in breast volume and T{sub 2} relaxation times differed in controls and patients during menses, ovulation and premenses. Method: Breast volume was determined by the Cavalieri method in combination with point counting techniques on MR images and T{sub 2} relaxation times of the water and fat in a voxel of breast tissue were obtained using {sup 1}H Magnetic Resonance Spectroscopy (MRS). Results: Statistical analysis (ANOVA) demonstrated highly significant differences in breast volume between the three stages of the cycle (p < 0.0005) with breast volume being greatest premenstrually. Patients did not exhibit an increase in volume premenstrually, significantly above controls. T{sub 2} of fat or water did not depend on stage of cycle. T-tests demonstrated no significant differences in T{sub 2} of water or fat between patient and control groups. The average T{sub 2} relaxation time of water was lowest in the patient and control groups during ovulation and highest in the patient group during premenses. Conclusion: We have performed the first combined volumetric and spectroscopic study of women with cyclical mastalgia and demonstrated that the global changes in volumes and T{sub 2} were not significantly different from normal

  16. Variation in the shape of the tibial insertion site of the anterior cruciate ligament: classification is required.

    Science.gov (United States)

    Guenther, Daniel; Irarrázaval, Sebastian; Nishizawa, Yuichiro; Vernacchia, Cara; Thorhauer, Eric; Musahl, Volker; Irrgang, James J; Fu, Freddie H

    2017-08-01

    To propose a classification system for the shape of the tibial insertion site (TIS) of the anterior cruciate ligament (ACL) and to demonstrate the intra- and inter-rater agreement of this system. Due to variation in shape and size, different surgical approaches may be feasible to improve reconstruction of the TIS. One hundred patients with a mean age of 26 ± 11 years were included. The ACL was cut arthroscopically at the base of the tibial insertion site. Arthroscopic images were taken from the lateral and medial portal. Images were de-identified and duplicated. Two blinded observers classified the tibial insertion site according to a classification system. The tibial insertion site was classified as type I (elliptical) in 51 knees (51 %), type II (triangular) in 33 knees (33 %) and type III (C-shaped) in 16 knees (16 %). There was good agreement between raters when viewing the insertion site from the lateral portal (κ = 0.65) as well as from the medial portal (κ = 0.66). Intra-rater reliability was good to excellent. Agreement in the description of the insertion site between the medial and lateral portals was good for rater 1 and good for rater 2 (κ = 0.74 and 0.77, respectively). There is variation in the shape of the ACL TIS. The classification system is a repeatable and reliable tool to summarize the shape of the TIS using three common patterns. For clinical relevance, different shapes may require different types of reconstruction to ensure proper footprint restoration. Consideration of the individual TIS shape is required to prevent iatrogenic damage of adjacent structures like the menisci. III.

  17. Cellular basis of morphological variation and temperature-related plasticity in Drosophila melanogaster strains with divergent wing shapes.

    Science.gov (United States)

    Torquato, Libéria Souza; Mattos, Daniel; Matta, Bruna Palma; Bitner-Mathé, Blanche Christine

    2014-12-01

    Organ shape evolves through cross-generational changes in developmental patterns at cellular and/or tissue levels that ultimately alter tissue dimensions and final adult proportions. Here, we investigated the cellular basis of an artificially selected divergence in the outline shape of Drosophila melanogaster wings, by comparing flies with elongated or rounded wing shapes but with remarkably similar wing sizes. We also tested whether cellular plasticity in response to developmental temperature was altered by such selection. Results show that variation in cellular traits is associated with wing shape differences, and that cell number may play an important role in wing shape response to selection. Regarding the effects of developmental temperature, a size-related plastic response was observed, in that flies reared at 16 °C developed larger wings with larger and more numerous cells across all intervein regions relative to flies reared at 25 °C. Nevertheless, no conclusive indication of altered phenotypic plasticity was found between selection strains for any wing or cellular trait. We also described how cell area is distributed across different intervein regions. It follows that cell area tends to decrease along the anterior wing compartment and increase along the posterior one. Remarkably, such pattern was observed not only in the selected strains but also in the natural baseline population, suggesting that it might be canalized during development and was not altered by the intense program of artificial selection for divergent wing shapes.

  18. Viscosity of water-in-oil emulsions. Variation with temperature and water volume fraction

    Energy Technology Data Exchange (ETDEWEB)

    Farah, Marco A.; Caldas, Jorge Navaes [Petroleo Brasileiro S.A., Rua General Canabarro, 500, Maracana, Rio, CEP 2057-900 (Brazil); Oliveira, Roberto C. [Petroleo Brasileiro S.A., Cenpes, Cidade Universitaria (Brazil); Rajagopal, Krishnaswamy [LATCA-Laboratorio de Termodinamica e Cinetica Aplicada-Escola de Quimica, Departamento de Engenharia Quimica, Universidade Federal do Rio de Janeiro, UFRJ, Cidade Universitaria, C.P. 68452, CEP 21949-900, Rio de Janeiro (Brazil)

    2005-09-15

    Water-in-oil emulsions are important in the petroleum industry in production operations, where the water content of the emulsion can be as high as 60% in volume, also in petroleum refining operations where generally the water content is low. The effective viscosity of water-in-oil emulsions depends mainly on the volume fraction of dispersed phase and temperature, along with several minor effects, such as shear rate, average droplet size, droplet size distribution, viscosity and density of oil. Using six different crude oils, the effective viscosities of several synthetic water-in-oil emulsions are measured at atmospheric pressure using a dynamic viscosimeter for different shear rates, temperatures and volume fractions of the dispersed phase. The ASTM equation, method D-341, for describing viscosity as a function of temperature is extended to include the variation of dispersed phase volume fraction. The proposed equation gives good correlation between the measured viscosities of water-in-oil emulsions as a function of temperature and the volume fraction of water.

  19. Small-scale variations in leaf shape under anthropogenic disturbance in dioecious forest forb mercurialis perennis: A geometric morphometric examination

    Directory of Open Access Journals (Sweden)

    Vujić Vukica

    2016-01-01

    Full Text Available Plants are exposed to increasing levels of diverse human activities that have profound effects on their overall morphology and, specifically, on leaf morphology. Anthropogenic disturbances in urban and suburban forest recreational sites are attracting growing research interest. To explore the persisting recreational impact on leaf shape and size, we conducted a field study on the dioecious forb Mercurialis perennis L. (Euphorbiaceae, typical for undisturbed understory communities. We selected adjacent sites in a suburban forest, which experience contrasting regimes of disturbance by human trampling under otherwise concordant natural conditions. Patterns of leaf shape and size variation and putative sex-specific response to disturbance were analyzed using a geometric morphometric approach. In addition to leaf-level data, plant height, internode and leaf number were analyzed to explore the same response at the whole-plant level. The results show significant variations associated with disturbance at both levels: plants growing under a heavy disturbance regime had shorter stems with a greater number of wider and shorter leaves. Significant differences between sites were also found for leaf size, with larger leaves observed in an undisturbed site. The effects of sex and sex x site interaction on leaf size and shape were nonsignificant, pointing to the absence of sexual dimorphism and sex-specific response to disturbance. Contrary to leaf shape and size, all three analyzed shoot traits showed highly significant sexual dimorphism, with male plants being higher and having higher leaf and internode count. [Projekat Ministarstva nauke Republike Srbije, br. 173025

  20. Effect of structural modifications on the drying kinetics of foods: changes in volume, surface area and product shape

    Directory of Open Access Journals (Sweden)

    Antonio De Michelis

    2013-10-01

    Full Text Available Macro and micro-structural changes take place during food dehydration. Macro-structural changes encompass modifications in shape, area and volume. Studies of such changes are important because dehydration kinetics (essential for calculating industrial dryers may be highly influenced by changes in food shape and dimensions. The overall changes in volume, surface area (“shrinkage” and shape (Heywood factor, with provides a close description of food shape were determined experimentally, and the results were correlated with simple expressions. Hence, although dehydration kinetics can be modeled with simplified overall shrinkage expressions, the possibility of selecting a suitable geometry and predicting the characteristics dimensions will provide higher accuracy. An additional unresolved problem is the lack of a general model that predicts macro-structural changes for various foods and diverse geometries. In this work, based on experimental data of sweet and sour cherries, and rose hip fruits, a simplified general model to predict changes in volume and surface area are proposed. To estimate how the changes in characteristic dimensions affect the kinetic studies, experimental drying curves for the three fruits by means of a diffusional model considered the following variants for the characteristic dimensions: (i The radius of the fresh food, assumed constant; (ii The radius of the partially dehydrated product; (iii The radius predicted by the correlation for structural changes, especially volume, obtained in this work and generalized for the three fruits, and (iv to demonstrate the need to study the macro-structural changes for all dehydrated foods, also be present the case of a restructured food.

  1. Intraspecific variation in body size and shape in an Andean highland anole species, Anolis ventrimaculatus (Squamata: Dactyloidae

    Directory of Open Access Journals (Sweden)

    Martha L. Calderón-Espinosa

    2013-03-01

    Full Text Available Variation in body characteristics related to lizard locomotion has been poorly studied at the intraspecific level in Anolis species. Local adaptation due to habitat heterogeneity has been reported in some island species. However, studies of mainland species are particularly scarce and suggest different patterns: high variability among highland lizards and poorly differentiated populations in one Amazonian species. We characterized inter population variation of body size and shape in the highland Andean Anolis ventrimaculatus, an endemic species from Western Colombia. A total of 15 morphometric variables were measured in specimens from the reptile collection of the Instituto de Ciencias Naturales, Universidad Nacional, Colombia. The study included individuals from seven different highland localities. We found size and shape sexual dimorphism, both of which varied among localities. Patterns of variation in body proportions among populations were different in both males and females, suggesting that either sexual or natural selective factors are different in each locality and between sexes. Since this species exhibits a fragmented distribution in highlands, genetic divergence may also be a causal factor of the observed variation. Ecological, behavioral, additional morphological as well as phylogenetic data, may help to understand the evolutionary processes behind the geographic patterns found in this species.

  2. Intraspecific variation in body size and shape in an andean highland anole species, Anolis ventrimaculatus (Squamata: Dactyloidae).

    Science.gov (United States)

    Calderón-Espinosa, Martha L; Ortega-León, Angela M; Zamora-Abrego, Joan G

    2013-03-01

    Variation in body characteristics related to lizard locomotion has been poorly studied at the intraspecific level in Anolis species. Local adaptation due to habitat heterogeneity has been reported in some island species. However, studies of mainland species are particularly scarce and suggest different patterns: high variability among highland lizards and poorly differentiated populations in one Amazonian species. We characterized inter population variation of body size and shape in the highland Andean Anolis ventrimaculatus, an endemic species from Western Colombia. A total of 15 morphometric variables were measured in specimens from the reptile collection of the Instituto de Ciencias Naturales, Universidad Nacional, Colombia. The study included individuals from seven different highland localities. We found size and shape sexual dimorphism, both of which varied among localities. Patterns of variation in body proportions among populations were different in both males and females, suggesting that either sexual or natural selective factors are different in each locality and between sexes. Since this species exhibits a fragmented distribution in highlands, genetic divergence may also be a causal factor of the observed variation. Ecological, behavioral, additional morphological as well as phylogenetic data, may help to understand the evolutionary processes behind the geographic patterns found in this species.

  3. Genomic regulation of natural variation in cortical and noncortical brain volume

    Directory of Open Access Journals (Sweden)

    Laughlin Rick E

    2006-02-01

    Full Text Available Abstract Background The relative growth of the neocortex parallels the emergence of complex cognitive functions across species. To determine the regions of the mammalian genome responsible for natural variations in cortical volume, we conducted a complex trait analysis using 34 strains of recombinant inbred (Rl strains of mice (BXD, as well as their two parental strains (C57BL/6J and DBA/2J. We measured both neocortical volume and total brain volume in 155 coronally sectioned mouse brains that were Nissl stained and embedded in celloidin. After correction for shrinkage, the measured cortical and noncortical brain volumes were entered into a multiple regression analysis, which removed the effects of body size and age from the measurements. Marker regression and interval mapping were computed using WebQTL. Results An ANOVA revealed that more than half of the variance of these regressed phenotypes is genetically determined. We then identified the regions of the genome regulating this heritability. We located genomic regions in which a linkage disequilibrium was present using WebQTL as both a mapping engine and genomic database. For neocortex, we found a genome-wide significant quantitative trait locus (QTL on chromosome 11 (marker D11Mit19, as well as a suggestive QTL on chromosome 16 (marker D16Mit100. In contrast, for noncortex the effect of chromosome 11 was markedly reduced, and a significant QTL appeared on chromosome 19 (D19Mit22. Conclusion This classic pattern of double dissociation argues strongly for different genetic factors regulating relative cortical size, as opposed to brain volume more generally. It is likely, however, that the effects of proximal chromosome 11 extend beyond the neocortex strictly defined. An analysis of single nucleotide polymorphisms in these regions indicated that ciliary neurotrophic factor (Cntf is quite possibly the gene underlying the noncortical QTL. Evidence for a candidate gene modulating neocortical

  4. Pulse pressure variation as a guide for volume expansion in dogs undergoing orthopedic surgery.

    Science.gov (United States)

    Fantoni, Denise T; Ida, Keila K; Gimenes, André M; Mantovani, Matheus M; Castro, Jacqueline R; Patrício, Geni C F; Ambrósio, Aline M; Otsuki, Denise A

    2017-07-01

    To investigate whether pulse pressure variation (PPV) can predict fluid responsiveness in healthy dogs during clinical surgery. Prospective clinical study. Thirty-three isoflurane-anesthetized dogs with arterial hypotension during orthopedic surgery. Fluid challenge with lactated Ringer's solution (15 mL kg -1 in 15 minutes) was administered in mechanically ventilated dogs (tidal volume 10 mL kg -1 ) with hypotension [mean arterial pressure (MAP) dogs, resulting in a decrease in PPV (p dogs. The increase in CO was correlated with the decrease in PPV (r = -0.65; p dogs, PPV predicted fluid responsiveness to volume expansion, and MAP and CVP did not show such applicability. Copyright © 2017 Association of Veterinary Anaesthetists and American College of Veterinary Anesthesia and Analgesia. Published by Elsevier Ltd. All rights reserved.

  5. Femoral subtrochanteric shape variation in Albania: implications for use in forensic applications.

    Science.gov (United States)

    McIlvaine, B K; Schepartz, L A

    2015-02-01

    This paper investigates temporal trends in femoral subtrochanteric shape in Albanian skeletal material to evaluate levels of platymeria in a set of populations with European ancestry. Although flattening of the diaphysis in the subtrochanteric region has been associated with individuals of Native American and Asian ancestry, high levels of platymeria may not be unique to those groups. The forensic utility of Gilbert and Gill's (Skeletal Attribution of Race: Methods for Forensic Anthropology, University of New Mexico, Albuquerque, 1990) method for identifying ancestry from femoral subtrochanteric shape is examined using non-American skeletons of European ancestry. Femoral subtrochanteric anteroposterior and mediolateral diameters for Albanian skeletons from Apollonia (n=117) and Lofkënd (n=50) are assessed for temporal trends and then compared with published data using one-way ANOVA and post-hoc Tukey tests. High degrees of subtrochanteric flattening are identified in the Albanian samples and statistically significant temporal trends of decreasing platymeria are documented. Although recent publications suggest that subtrochanteric shape is less effective in identifying ancestry then was initially proposed, forensic anthropologists still commonly use femoral subtrochanteric shape to determine ancestry among skeletonized remains. This paper's findings support the assertion that proximal femoral morphology is functionally related, and more likely to be influenced by biomechanical adaptation and body proportions than genetic constraints. Copyright © 2014 Elsevier GmbH. All rights reserved.

  6. LV wall segmentation using the variational level set method (LSM) with additional shape constraint for oedema quantification

    Science.gov (United States)

    Kadir, K.; Gao, H.; Payne, A.; Soraghan, J.; Berry, C.

    2012-10-01

    In this paper an automatic algorithm for the left ventricle (LV) wall segmentation and oedema quantification from T2-weighted cardiac magnetic resonance (CMR) images is presented. The extent of myocardial oedema delineates the ischaemic area-at-risk (AAR) after myocardial infarction (MI). Since AAR can be used to estimate the amount of salvageable myocardial post-MI, oedema imaging has potential clinical utility in the management of acute MI patients. This paper presents a new scheme based on the variational level set method (LSM) with additional shape constraint for the segmentation of T2-weighted CMR image. In our approach, shape information of the myocardial wall is utilized to introduce a shape feature of the myocardial wall into the variational level set formulation. The performance of the method is tested using real CMR images (12 patients) and the results of the automatic system are compared to manual segmentation. The mean perpendicular distances between the automatic and manual LV wall boundaries are in the range of 1-2 mm. Bland-Altman analysis on LV wall area indicates there is no consistent bias as a function of LV wall area, with a mean bias of -121 mm2 between individual investigator one (IV1) and LSM, and -122 mm2 between individual investigator two (IV2) and LSM when compared to two investigators. Furthermore, the oedema quantification demonstrates good correlation when compared to an expert with an average error of 9.3% for 69 slices of short axis CMR image from 12 patients.

  7. Target volume delineation in external beam partial breast irradiation: less inter-observer variation with preoperative- compared to postoperative delineation

    NARCIS (Netherlands)

    Leij, F. van der; Elkhuizen, P.H.M.; Janssen, T.M.; Poortmans, P.M.P.; Sangen, M. van der; Scholten, A.N.; Vliet-Vroegindeweij, C. van; Boersma, L.J.

    2014-01-01

    The challenge of adequate target volume definition in external beam partial breast irradiation (PBI) could be overcome with preoperative irradiation, due to less inter-observer variation. We compared the target volume delineation for external beam PBI on preoperative versus postoperative CT scans of

  8. Shape and size variation: growth and development of the dusky grouper (Epinephelus marginatus Lowe, 1834).

    Science.gov (United States)

    Russo, Tommaso; Pulcini, Domitilla; Bruner, Emiliano; Cataudella, Stefano

    2009-01-01

    Demersal fishes have complex life cycles that involve an ontogenetic change in morphology, physiology, and behavior, as their pelagic larval stages colonize benthic habitats. The developmental transition between larvae and juveniles leads to very complex processes of morphogenesis and differentiation. These processes primarily determine changes in external morphology, which is shaped by selective pressures to optimize performance for basic activities such as swimming, escape from predators, and feeding. Fishes have provided fertile grounds for ecomorphological investigations throughout ontogeny, as the role of changing morphology in inducing ontogenetic niche shifts is not always clear. In this framework, some studies have demonstrated that certain species undergo gradual changes, whereas other species experience threshold effects in their ecomorphological relationships during ontogeny. In this study, the intraspecific allometry of the dusky grouper was examined. Geometric morphometric tools were used to quantify shape changes through the development, and a modular approach was also applied to analyze the pattern of covariation between three distinct blocks (head, trunk, and tail). For this purpose, a two-block Partial Least Square was computed. This method reveals that the pattern of changes in the overall body shape is the result of the modularized changes of these blocks. 2008 Wiley-Liss, Inc.

  9. Viscosity-dependent variations in the cell shape and swimming manner of Leptospira.

    Science.gov (United States)

    Takabe, Kyosuke; Tahara, Hajime; Islam, Md Shafiqul; Affroze, Samia; Kudo, Seishi; Nakamura, Shuichi

    2017-02-01

    Spirochaetes are spiral or flat-wave-shaped Gram-negative bacteria that have periplasmic flagella between the peptidoglycan layer and outer membrane. Rotation of the periplasmic flagella transforms the cell body shape periodically, allowing the cell to swim in aqueous environments. Because the virulence of motility-deficient mutants of pathogenic species is drastically attenuated, motility is thought to be an essential virulence factor in spirochaetes. However, it remains unknown how motility practically contributes to the infection process. We show here that the cell body configuration and motility of the zoonotic spirochaete Leptospira changes depending on the viscosity of the medium. Leptospira swim and reverse the swimming direction by transforming the cell body. Motility analysis showed that the frequency of cell shape transformation was increased by increasing the viscosity of the medium. The increased cell body transformation induced highly frequent reversal of the swimming direction. A simple kinetic model based on the experimental results shows that the viscosity-induced increase in reversal limits cell migration, resulting in the accumulation of cells in high-viscosity regions. This behaviour could facilitate the colonization of the spirochaete on host tissues covered with mucosa.

  10. Allelic heterogeneity and trade-off shape natural variation for response to soil micronutrient.

    Directory of Open Access Journals (Sweden)

    Seifollah Poormohammad Kiani

    Full Text Available As sessile organisms, plants have to cope with diverse environmental constraints that may vary through time and space, eventually leading to changes in the phenotype of populations through fixation of adaptive genetic variation. To fully comprehend the mechanisms of evolution and make sense of the extensive genotypic diversity currently revealed by new sequencing technologies, we are challenged with identifying the molecular basis of such adaptive variation. Here, we have identified a new variant of a molybdenum (Mo transporter, MOT1, which is causal for fitness changes under artificial conditions of both Mo-deficiency and Mo-toxicity and in which allelic variation among West-Asian populations is strictly correlated with the concentration of available Mo in native soils. In addition, this association is accompanied at different scales with patterns of polymorphisms that are not consistent with neutral evolution and show signs of diversifying selection. Resolving such a case of allelic heterogeneity helps explain species-wide phenotypic variation for Mo homeostasis and potentially reveals trade-off effects, a finding still rarely linked to fitness.

  11. Differential Regulation of Cryptic Genetic Variation Shapes the Genetic Interactome Underlying Complex Traits.

    Science.gov (United States)

    Yadav, Anupama; Dhole, Kaustubh; Sinha, Himanshu

    2016-12-01

    Cryptic genetic variation (CGV) refers to genetic variants whose effects are buffered in most conditions but manifest phenotypically upon specific genetic and environmental perturbations. Despite having a central role in adaptation, contribution of CGV to regulation of quantitative traits is unclear. Instead, a relatively simplistic architecture of additive genetic loci is known to regulate phenotypic variation in most traits. In this paper, we investigate the regulation of CGV and its implication on the genetic architecture of quantitative traits at a genome-wide level. We use a previously published dataset of biparental recombinant population of Saccharomyces cerevisiae phenotyped in 34 diverse environments to perform single locus, two-locus, and covariance mapping. We identify loci that have independent additive effects as well as those which regulate the phenotypic manifestation of other genetic variants (variance QTL). We find that whereas additive genetic variance is predominant, a higher order genetic interaction network regulates variation in certain environments. Despite containing pleiotropic loci, with effects across environments, these genetic networks are highly environment specific. CGV is buffered under most allelic combinations of these networks and perturbed only in rare combinations resulting in high phenotypic variance. The presence of such environment specific genetic networks is the underlying cause of abundant gene–environment interactions. We demonstrate that overlaying identified molecular networks on such genetic networks can identify potential candidate genes and underlying mechanisms regulating phenotypic variation. Such an integrated approach applied to human disease datasets has the potential to improve the ability to predict disease predisposition and identify specific therapeutic targets.

  12. Respiratory variations in the arterial pressure during mechanical ventilation reflect volume status and fluid responsiveness.

    Science.gov (United States)

    Perel, Azriel; Pizov, Reuven; Cotev, Shamay

    2014-06-01

    Optimal fluid management is one of the main challenges in the care of the critically ill. However, the physiological parameters that are commonly monitored and used to guide fluid management are often inadequate and even misleading. From 1987 to 1989 we published four experimental studies which described a method for predicting the response of the cardiac output to fluid administration during mechanical ventilation. The method is based on the analysis of the variations in the arterial pressure in response to a mechanical breath, which serves as a repetitive hemodynamic challenge. Our studies showed that the systolic pressure variation and its components are able to reflect even small changes in the circulating blood volume. Moreover, these dynamic parameters provide information about the slope of the left ventricular function curve, and therefore predict the response to fluid administration better than static preload parameters. Many new dynamic parameters have been introduced since then, including the pulse pressure (PPV) and stroke volume (SVV) variations, and various echocardiographic and other parameters. Though seemingly different, all these parameters are based on measuring the response to a predefined preload-modifying maneuver. The clinical usefulness of these 'dynamic' parameters is limited by many confounding factors, the recognition of which is absolutely necessary for their proper use. With more than 20 years of hindsight we believe that our early studies helped pave the way for the recognition that fluid administration should ideally be preceded by the assessment of "fluid responsiveness". The introduction of dynamic parameters into clinical practice can therefore be viewed as a significant step towards a more rational approach to fluid management.

  13. Effects of particle shape on volume and mass estimates of interstellar grains

    Science.gov (United States)

    Greenberg, J. M.; Hong, S. S.

    1975-01-01

    Mass estimates of interstellar grain materials based on visual extinction characteristics are shown to be insensitive to shape and, so long as the wavelength dependence of extinction is defined well into the infrared, they are also insensitive to size distribution. Spheroidal particles are treated by an approximate analytical method. Spheres and cylinders (core mantle as well as homogeneous) are treated by exact methods.

  14. Pedestal and confinement properties under shape and magnetic topology variation on Alcator C-Mod

    Science.gov (United States)

    Hughes, J. W.; Lipschultz, B.; Whyte, D.; Marmar, E. S.; Greenwald, M.; Hubbard, A. E.; McDermott, R. M.

    2008-11-01

    Recent work on Alcator C-Mod has examined the influence of magnetic topology and equilibrium shape on edge pedestal structure and plasma confinement. H-mode pedestal parameters show a striking sensitivity to the ion ∇B drift direction, relative to the active x-point position, with considerable variability observed when the distance between separatrices is on the order of the pedestal width (˜5mm) or less, i.e. very near double null (DN). Near DN H-modes can have improved confinement factors (H98>1) as a result of elevated pedestal temperature (Tped), with the edge regulated by benign small edge-localized modes (ELMs) or continuous modes. Such operational regimes with no large ELMs are desirable for ITER and other future devices. Discharges with L-mode-like particle confinement, yet with H98 1 and Tped 1keV, were maintained steady-state by operating with high current, strong shaping and unfavorable ∇B drift direction, while holding input power below the L-H threshold to prevent particle barrier formation. The pedestal and confinement properties of these improved ELM-free regimes will be compared to those of typical H-modes.

  15. Natural Selection and Recombination Rate Variation Shape Nucleotide Polymorphism Across the Genomes of Three Related Populus Species.

    Science.gov (United States)

    Wang, Jing; Street, Nathaniel R; Scofield, Douglas G; Ingvarsson, Pär K

    2016-03-01

    A central aim of evolutionary genomics is to identify the relative roles that various evolutionary forces have played in generating and shaping genetic variation within and among species. Here we use whole-genome resequencing data to characterize and compare genome-wide patterns of nucleotide polymorphism, site frequency spectrum, and population-scaled recombination rates in three species of Populus: Populus tremula, P. tremuloides, and P. trichocarpa. We find that P. tremuloides has the highest level of genome-wide variation, skewed allele frequencies, and population-scaled recombination rates, whereas P. trichocarpa harbors the lowest. Our findings highlight multiple lines of evidence suggesting that natural selection, due to both purifying and positive selection, has widely shaped patterns of nucleotide polymorphism at linked neutral sites in all three species. Differences in effective population sizes and rates of recombination largely explain the disparate magnitudes and signatures of linked selection that we observe among species. The present work provides the first phylogenetic comparative study on a genome-wide scale in forest trees. This information will also improve our ability to understand how various evolutionary forces have interacted to influence genome evolution among related species. Copyright © 2016 by the Genetics Society of America.

  16. Variation in the degree of pectin methylesterification during the development of Baccharis dracunculifolia kidney-shaped gall.

    Directory of Open Access Journals (Sweden)

    Denis Coelho de Oliveira

    Full Text Available Insect galls may be study models to test the distribution of pectins and arabinogalactan-proteins (AGPs and their related functions during plant cell cycles. These molecules are herein histochemically and immunocitochemically investigated in the kidney-shaped gall induced by Baccharopelma dracunculifoliae (Psyllidae on leaves of Baccharis dracunculifolia DC. (Asteraceae on developmental basis. The homogalacturonans (HGAs (labeled by JIM5 and the arabinans (labeled by LM6 were detected either in non-galled leaves or in young galls, and indicated stiffening of epidermal cell walls, which is an important step for cell redifferentiation. The labeling of HGAs by JIM7 changed from young to senescent stage, with an increase in the rigidity of cell walls, which is important for the acquaintance of the final gall shape and for the mechanical opening of the gall. The variation on the degree of HGAs during gall development indicated differential PMEs activity during gall development. The epitopes recognized by LM2 (AGP glycan and LM5 (1-4-β-D-galactans had poor alterations from non-galled leaves towards gall maturation and senescence. Moreover, the dynamics of pectin and AGPs on two comparable mature kidney-shaped galls on B. dracunculifolia and on B. reticularia revealed specific peculiarities. Our results indicate that similar gall morphotypes in cogeneric host species may present distinct cell responses in the subcelular level, and also corroborate the functions proposed in literature for HGAs.

  17. Comparisons of Lesion Volumes and Shapes Produced by a Radiofrequency System with a Cooled, a Protruding, or a Monopolar Probe.

    Science.gov (United States)

    Cedeno, David L; Vallejo, Alejandro; Kelley, Courtney A; Tilley, Dana M; Kumar, Nitesh

    2017-09-01

    Radiofrequency (RF) ablation for denervation has been utilized for decades in chronic pain management. This relies on the proper targeting of the affected nerve which may be obtained by creating an ablation lesion with a shape and volume that optimizes targeting. Various systems designed to improve lesion size are available. These include cooling the active tip (cooled-RF) and protruding the RF electrode outside the active tip (PERF). This study compares lesion volumes of 3 commercially available RF systems: cooled-RF, "V" shaped active cannula and protruding electrode (18 g and 20 g), and monopolar RF (MRF; 16 g, 18 g, and 20 g). Ex vivo study using clinically relevant conditions. Biophysical laboratory in an academic institution. RF ablation lesions were generated in additive-free chicken breast specimens (n = 10) with the RF probes fully inserted in them. For cooled RF, a 17 g probe (4 mm active tip) was used. RF was applied for 150 seconds at 60°C. PERF was applied using 18 g or 20 g introducers (10 mm active tip) for either 90 or 150 seconds at 80°C. For MRF ablation, introducers diameter were 16 g, 18 g, or 20 g (10 mm active tip), while RF was applied for 90 seconds at 80°C. Tissues were dissected through the midpoint of the lesion, and measurements of the longitudinal, transversal, and depth lengths were taken and used to calculate the lesion volume. Measurements from the distal edge in the transverse and longitudinal directions were also recorded. One-way ANOVA was used to determine statistical significance between volume means (P lesion volume with cooled RF (595 mm3) is significantly larger than any other mean volume measured. The second largest volume is produced with MRF using a 16 g introducer (360 mm3), which is significantly larger than those obtained with 18 g or 20 g. This is also significantly larger than the one obtained with PERF using an 18 g introducer. Mean lesion volume produced with PERF (80°C for 90 seconds) and an 18 g diameter tip

  18. Variation in loss of immunity shapes influenza epidemics and the impact of vaccination.

    Science.gov (United States)

    Woolthuis, Rutger G; Wallinga, Jacco; van Boven, Michiel

    2017-09-19

    Protective antibody immunity against the influenza A virus wanes in 2-7 years due to antigenic drift of the virus' surface proteins. The duration of immune protection is highly variable because antigenic evolution of the virus is irregular. Currently, the variable nature of the duration of immunity has had little attention in analyses of the impact of vaccination, including cost-effectiveness studies. We developed a range of mathematical transmission models to investigate the effect of variable duration of immunity on the size of seasonal epidemics. The models range from simple conceptual to more realistic, by distinguishing between infection- versus vaccination-induced immunity, by inclusion of primary vaccine failure, by assuming a leaky vaccine, and by the inclusion of age-dependent contact patterns. We show that annual variation in the duration of immunity causes large variation in the size of epidemics, and affects the effectiveness of vaccination. Accumulation of susceptible individuals in one or more mild seasons results in a disproportionately large outbreak in a subsequent season. Importantly, variation in the duration of immunity increases the average infection attack rate when the vaccination coverage is around the outbreak threshold. Specifically, in a tailored age-stratified model with a realistic reproduction number (R 0 = 1.4) and vaccination coverage of 25%, we find that the attack rate in unvaccinated children (vaccination, and that vaccine effectiveness cannot be judged for each year in isolation. Our findings have implications for vaccination strategies that aim to maximize the vaccination coverage while extending the age range of persons eligible for vaccination.

  19. Intraspecific variation shapes community-level behavioral responses to urbanization in spiders.

    Science.gov (United States)

    Dahirel, Maxime; Dierick, Jasper; De Cock, Maarten; Bonte, Dries

    2017-09-01

    Urban areas are an extreme example of human-changed environments, exposing organisms to multiple and strong selection pressures. Adaptive behavioral responses are thought to play a major role in animals' success or failure in such new environments. Approaches based on functional traits have proven especially valuable to understand how species communities respond to environmental gradients. Until recently, they have, however, often ignored the potential consequences of intraspecific trait variation (ITV). When ITV is prevalent, it may highly impact ecological processes and resilience against stressors. This may be especially relevant in animals, in which behavioral traits can be altered very flexibly at the individual level to track environmental changes. We investigated how species turnover and ITV influenced community-level behavioral responses in a set of 62 sites of varying levels of urbanization, using orb web spiders and their webs as models of foraging behavior. ITV alone explained around one-third of the total trait variation observed among communities. Spider web structure changed according to urbanization, in ways that increase the capture efficiency of webs in a context of smaller urban prey. These trait shifts were partly mediated by species turnover, but ITV increased their magnitude, potentially helping to buffer the effects of environmental changes on communities. The importance of ITV varied depending on traits and on the spatial scale at which urbanization was considered. Despite being neglected from community-level analyses in animals, our results highlight the importance of accounting for intraspecific trait variation to fully understand trait responses to (human-induced) environmental changes and their impact on ecosystem functioning. © 2017 by the Ecological Society of America.

  20. Sexual Dimorphism of the Human Tibia through Time: Insights into Shape Variation Using a Surface-Based Approach.

    Directory of Open Access Journals (Sweden)

    Hana Brzobohatá

    Full Text Available In this paper we present a three-dimensional (3D morphometrical assessment of human tibia sexual dimorphism based on whole bone digital representation. To detect shape-size and shape differences between sexes, we used geometric morphometric tools and colour-coded surface deviation maps. The surface-based methodology enabled analysis of sexually dimorphic features throughout the shaft and articular ends of the tibia. The overall study dataset consisted of 183 3D models of adult tibiae from three Czech population subsets, dating to the early medieval (9-10th century (N = 65, early 20th century (N = 61 and 21st-century (N = 57. The time gap between the chronologically most distant and contemporary datasets was more than 1200 years. The results showed that, in all three datasets, sexual dimorphism was pronounced. There were some sex-dimorphic characteristics common to all three samples, such as tuberosity protrusion, anteriorly bowed shaft and relatively larger articular ends in males. Diachronic comparisons also revealed substantial shape variation related to the most dimorphic area. Male/female distinctions showed a consistent temporal trend regarding the location of dimorphic areas (shifting distally with time, while the maximal deviation between male and female digitized surfaces fluctuated and reached the lowest level in the 21st-century sample. Sex determination on a whole-surface basis yielded the lowest return of correct sex assignment in the 20th-century group, which represented the lowest socioeconomic status. The temporal variation could be attributed to changes in living conditions, the decreasing lower limb loading/labour division in the last 12 centuries having the greatest effect. Overall, the results showed that a surface-based approach is successful for analysing complex long bone geometry.

  1. High-frequency Quasi-periodic Light Variations from Arc-shaped Gas Clouds Falling onto a Black Hole

    Science.gov (United States)

    Moriyama, Kotaro; Mineshige, Shin; Takahashi, Hiroyuki R.

    2017-11-01

    We investigate the dynamical and radiative properties of arc-shaped gas clouds falling onto a stellar-mass black hole based on the three-dimensional general relativistic radiation-magnetohydrodynamics (3D-GRRMHD) simulation data. Assuming that the gas clouds radiate mainly due to the free-free emission and/or optically thick, inverse Compton scattering, we calculate how the emissivity distributions develop with time. We find that (1) gas clouds, each of which has a ring-like or arc shape, are intermittently formed, and that (2) they slowly fall onto the black hole, keeping nearly the Keplerian orbital velocity. These features support the dynamical properties of the gas clouds assumed in the spin measurement method proposed by Moriyama & Mineshige, but the radius of the inner edge of the accretion disk is larger than that of the marginally stable orbit (ISCO). Next, we examine how each gas cloud is observed by a distant observer by calculating the photon trajectories in the black hole spacetime. The luminosity of the accretion flow exhibits significant time variations on different timescales, reflecting the time evolution of the gas density distributions. The relatively slow variations on the time durations of 0.08-0.10 s is due to the formation and fall of gas clouds, while quasi-periodic flux peaks with short time intervals (0.01 s) are due to the quasi-periodic enhancement of light from the non-axisymmetric arc-shaped clouds through the beaming effect. This may account for the high-frequency quasi-periodic oscillations (HF QPOs) observed in black hole binaries. The observational implications and future issues are briefly discussed.

  2. Feedbacks between community assembly and habitat selection shape variation in local colonization

    Science.gov (United States)

    Kraus, J.M.; Vonesh, J.R.

    2010-01-01

    1. Non-consumptive effects of predators are increasingly recognized as important drivers of community assembly and structure. Specifically, habitat selection responses to top predators during colonization and oviposition can lead to large differences in aquatic community structure, composition and diversity. 2. These differences among communities due to predators may develop as communities assemble, potentially altering the relative quality of predator vs. predator-free habitats through time. If so, community assembly would be expected to modify the subsequent behavioural responses of colonists to habitats containing top predators. Here, we test this hypothesis by manipulating community assembly and the presence of fish in experimental ponds and measuring their independent and combined effects on patterns of colonization by insects and amphibians. 3. Assembly modified habitat selection of dytscid beetles and hylid frogs by decreasing or even reversing avoidance of pools containing blue-spotted sunfish (Enneacanthus gloriosus). However, not all habitat selection responses to fish depended on assembly history. Hydrophilid beetles and mosquitoes avoided fish while chironomids were attracted to fish pools, regardless of assembly history. 4. Our results show that community assembly causes taxa-dependent feedbacks that can modify avoidance of habitats containing a top predator. Thus, non-consumptive effects of a top predator on community structure change as communities assemble and effects of competitors and other predators combine with the direct effects of top predators to shape colonization. 5. This work reinforces the importance of habitat selection for community assembly in aquatic systems, while illustrating the range of factors that may influence colonization rates and resulting community structure. Directly manipulating communities both during colonization and post-colonization is critical for elucidating how sequential processes interact to shape communities.

  3. Cranial shape and size variation in human evolution: structural and functional perspectives.

    Science.gov (United States)

    Bruner, Emiliano

    2007-12-01

    A GLIMPSE INTO MODERN PALEOANTHROPOLOGY: In the last decades, paleoanthropology has been deeply modified, changing from a descriptive and historical science to a more quantitative and analytical discipline. The covariation of multiple traits is investigated to study the evolutionary changes of the underlying anatomical models, mostly through the introduction of digital biomedical imaging procedures and of computed geometrical analyses supported by multivariate statistics. FUNCTIONAL CRANIOLOGY: The evolution of the human cranium is consequently considered in terms of functional and structural relationships between its components, largely influenced by the allometric variations associated with the increase in the relative cranial capacity. In the human genus, the changes in the face, base, and neurocranium are characterised by a mosaic variation, in which adaptations, secondary consequences, and stochastic factors concur to generate a set of anatomical possibilities and constraints. SYSTEMIC PERSPECTIVES TO THE EVOLUTION OF THE HUMAN CRANIAL MORPHOLOGY: Concepts like morphological modularity, anatomical integration, and heterochrony represent key issues in the development of the current human evolutionary studies.

  4. A three-dimensional geometric morphometrics view of the cranial shape variation and population history in the New World.

    Science.gov (United States)

    Galland, Manon; Friess, Martin

    2016-09-10

    Craniofacial variation in past and present Amerindians has been attributed to the effect of multiple founder events, or to one major migration followed by in situ differentiation and possibly recurrent contacts among Circum-Arctic groups. Our study aims to: (i) detect morphological differences that may indicate several migrations; (ii) test for the presence of genetic isolation; and (iii) test the correlation between shape data and competing settlement hypotheses by taking into account geography, chronology, climate effects, the presence of genetic isolation and recurrent gene flow. We analyzed a large sample of three-dimensional (3D) cranial surface scans (803 specimens) including past and modern groups from America and Australasia. Shape variation was investigated using geometric morphometrics. Differential external gene flow was evaluated by applying genetic concepts to morphometric data (Relethford-Blangero approach). Settlement hypotheses were tested using a matrix correlation approach (Mantel tests). Our results highlight the strong dichotomy between Circum-Arctic and continental Amerindians as well as the impact of climate adaptation, and possibly recurrent gene flow in the Circum-Arctic area. There is also evidence for the impact of genetic isolation on phenetic variation in Baja California. Several settlement hypotheses are correlated with our data. The three approaches used in this study highlight the importance of local processes especially in Baja California, and caution against the use of overly simplistic models when searching for the number of migration events. The results stress the complexity of the settlement of the Americas as well as the mosaic nature of the processes involved in this process. Am. J. Hum. Biol. 28:646-661, 2016. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  5. Variation of Red Blood Cell Distribution Width and Mean Platelet Volume after Moderate Endurance Exercise

    Directory of Open Access Journals (Sweden)

    Giuseppe Lippi

    2014-01-01

    Full Text Available Although physical exercise strongly influences several laboratory parameters, data about the hematological changes after medium distance running are scarce. We studied 31 middle-trained athletes (mean training regimen 217±32 min/week who performed a 21.1 km, half-marathon run. Blood samples were collected before the run, at the end, and 3 and 20 hours thereafter. The complete blood count was performed on Advia 2120 and included red blood cell (RBC, reticulocyte, and platelet counts; hemoglobin; mean corpuscular volume (MCV; mean corpuscular hemoglobin (MCH; reticulocyte haemoglobin content (Ret CHR; RBC distribution width (RDW, mean platelet volume (MPV. No significant variations were observed for MCH and Ret CHR. The RBC, reticulocyte, and hemoglobin values modestly decreased after the run. The MCV significantly increased at the end of running but returned to baseline 3 hours thereafter. The RDW constantly increased, reaching a peak 20 hours after the run. The platelet count and MPV both increased after the run and returned to baseline 3 hours thereafter. These results may have implications for definition of reference ranges and antidoping testing, and may also contribute to explaining the relationship between endurance exercise and mortality, since previous studies reported that RDW and MPV may be significantly associated with cardiovascular disease.

  6. Stroke volume variation in hepatic resection: a replacement for standard central venous pressure monitoring.

    Science.gov (United States)

    Dunki-Jacobs, Erik M; Philips, Prejesh; Scoggins, Charles R; McMasters, Kelly M; Martin, Robert C G

    2014-02-01

    Central venous pressure (CVP) is the standard method of volume status evaluation during hepatic resection. CVP monitoring requires preoperative placement of a central venous catheter (CVC), which can be associated with increased time, cost, and adverse events. Stroke volume variation (SVV) is a preload index that can be used to predict an individual's fluid responsiveness through an existing arterial line. The purpose of this study was to determine if SVV is as safe and effective as CVP in measuring volume status during hepatic resection. Two cohorts of 40 consecutive patients (80 total) were evaluated during hepatic resection between December 2010 and August 2012. The initial evaluation group of 40 patients had continuous CVP monitoring and SVV monitoring performed simultaneously to establish appropriate SVV parameters for hepatic resection. A validation group of 40 patients was then monitored with SVV alone to confirm the accuracy of the established SVV parameters. Type of hepatic resection, transection time, blood loss, complications, and additional operative and postoperative factors were collected prospectively. SVV was calculated using the Flotrac™/Vigileo™ System. The evaluation group included 40 patients [median age 62 (29-82) years; median body mass index (BMI) 27.7 (16.5-40.6)] with 18 laparoscopic, 22 open, and 24 undergoing major (≥3 segments) hepatectomy. Median transection times were 43 (range 20-65) min, median blood loss 250 (range 20-950) cc, with no Pringle maneuver utilized. In this evaluation group, a CVP of -1 to 1 significantly correlated to a SVV of 18-21 (R (2) = 0.85, p monitoring during hepatic resection with equivalent outcomes in terms of blood loss and parenchymal transection time. Using SVV as a predictor of fluid status could prove to be advantageous by avoiding the need for CVC insertion and therefor eliminating the risk of CVC related complications in patients undergoing hepatic resection.

  7. Variation in the shape and mechanical performance of the lower jaws in ceratopsid dinosaurs (Ornithischia, Ceratopsia).

    Science.gov (United States)

    Maiorino, Leonardo; Farke, Andrew A; Kotsakis, Tassos; Teresi, Luciano; Piras, Paolo

    2015-11-01

    Ceratopsidae represents a group of quadrupedal herbivorous dinosaurs that inhabited western North America and eastern Asia during the Late Cretaceous. Although horns and frills of the cranium are highly variable across species, the lower jaw historically has been considered to be relatively conservative in morphology. Here, the lower jaws from 58 specimens representing 21 ceratopsoid taxa were sampled, using geometric morphometrics and 2D finite element analysis (FEA) to explore differences in morphology and mechanical performance across Ceratopsoidea (the clade including Ceratopsidae, Turanoceratops and Zuniceratops). Principal component analyses and non-parametric permuted manovas highlight Triceratopsini as a morphologically distinct clade within the sample. A relatively robust and elongate dentary, a larger and more elongated coronoid process, and a small and dorso-ventrally compressed angular characterize this clade, as well as the absolutely larger size. By contrast, non-triceratopsin chasmosaurines, Centrosaurini and Pachyrhinosaurini have similar morphologies to each other. Zuniceratops and Avaceratops are distinct from other taxa. No differences in size between Pachyrhinosaurini and Centrosaurini are recovered using non-parametric permuted anovas. Structural performance, as evaluated using a 2D FEA, is similar across all groups as measured by overall stress, with the exception of Triceratopsini. Shape, size and stress are phylogenetically constrained. A longer dentary as well as a long coronoid process result in a lower jaw that is reconstructed as relatively much more stressed in triceratopsins. © 2015 Anatomical Society.

  8. Genetic, environmental and epigenetic influences on variation in human tooth number, size and shape.

    Science.gov (United States)

    Townsend, Grant; Bockmann, Michelle; Hughes, Toby; Brook, Alan

    2012-01-01

    The aim of this review is to highlight some key recent developments in studies of tooth number, size and shape that are providing better insights into the roles of genetic, environmental and epigenetic factors in the process of dental development. Advances in molecular genetics are helping to clarify how epigenetic factors influence the spatial and temporal regulation of the complex processes involved in odontogenesis. At the phenotypic level, the development of sophisticated systems for image analysis is enabling new dental phenotypes to be defined. The 2D and 3D data that are generated by these imaging systems can then be analysed with mathematical approaches, such as geometric morphometric analysis. By gathering phenotypic data and DNA from twins, it is now possible to use 'genome-wide' association studies and the monozygotic co-twin design to identify important genes in odontogenesis and also to clarify how epigenetic and environmental factors can affect this process. Given that many of the common dental anomalies affecting the human dentition are interrelated, apparently reflecting pleiotropic genetic effects, the discoveries and new directions described in this paper should have important implications for clinical dental practice in the future.

  9. On the intraspecific variation in morphometry and shape of sagittal otoliths of common sardine, Strangomera bentincki, off central-southern Chile

    Directory of Open Access Journals (Sweden)

    Sandra Curin-Osorio

    2012-11-01

    Full Text Available Size and shape of fish otoliths are species-specific, but some species also display intraspecific variations. The common sardine, Strangomera bentincki, is a small pelagic fish inhabiting a seasonal upwelling ecosystem off central-southern Chile, having two discrete spawning sites along its latitudinal distribution. Otoliths of specimens were collected from commercial catches in Talcahuano and Corral, representing the central and south spawning zones. On the basis of otolith images, size-based shape descriptors were used to detect ontogenetic variation, and morphometric variables (length, breadth, area, perimeter and weight were used to detect geographical differences in size and shape of otoliths. Outline analysis was studied on the basis of elliptic Fourier descriptors through multivariate statistical procedures. Size-based shape descriptors showed that otolith shape starts to be stable for fish larger than 12 cm total length, which keep an elliptical form. Morphometric variables for fish larger than 12 cm revealed intraspecific variation between central and south zones, which were associated with otolith weight and breadth. Outline analysis did not reveal significant spatial differences, but extreme intraspecific variation was due to the antirostrum, excisure, and posterior part of otoliths. Intraspecific variation in otolith size could be linked to differences in each spawning habitat and related to geographical origin, whose differences are not clearly identified. It is concluded that intraspecific variability in morphometric variables of sardine otoliths revealed geographic differences in size that are not attributable to allometric effects, and that otolith shape was similar between specimens from different geographic origin.

  10. Comparative study of pressure- and volume-controlled ventilation on pulse pressure variation in a model of hypovolaemia in rabbits.

    Science.gov (United States)

    Fonseca, E B; Otsuki, D A; Fantoni, D T; Bliacheriene, F; Auler, J O C

    2008-05-01

    Dynamic indices represented by systolic pressure variation and pulse pressure variation have been demonstrated to be more accurate than filling pressures in predicting fluid responsiveness. However, the literature is scarce concerning the impact of different ventilatory modes on these indices. We hypothesized that systolic pressure variation or pulse pressure variation could be affected differently by volume-controlled ventilation and pressure-controlled ventilation in an experimental model, during normovolaemia and hypovolaemia. Thirty-two anaesthetized rabbits were randomly allocated into four groups according to ventilatory modality and volaemic status where G1-ConPCV was the pressure-controlled ventilation control group, G2-HemPCV was associated with haemorrhage, G3-ConVCV was the volume-controlled ventilation control group and G4-HemVCV was associated with haemorrhage. In the haemorrhage groups, blood was removed in two stages: 15% of the estimated blood volume withdrawal at M1, and, 30 min later, an additional 15% at M2. Data were submitted to analysis of variance for repeated measures; a value of P ventilation modes. However, when 30% of the estimated blood volume was removed (M2), dynamic parameters became significantly higher in animals under volume-controlled ventilation when compared with those under pressure-controlled ventilation. Under normovolaemia and moderate haemorrhage, dynamic parameters were not influenced by either ventilatory modalities. However, in the second stage of haemorrhage (30%), animals in volume-controlled ventilation presented higher values of systolic pressure variation and pulse pressure variation when compared with those submitted to pressure-controlled ventilation.

  11. A geometric morphometric analysis of hominin upper premolars. Shape variation and morphological integration.

    Science.gov (United States)

    Gómez-Robles, Aida; Martinón-Torres, María; Bermúdez de Castro, José María; Prado-Simón, Leyre; Arsuaga, Juan Luis

    2011-12-01

    This paper continues the series of articles initiated in 2006 that analyse hominin dental crown morphology by means of geometric morphometric techniques. The detailed study of both upper premolar occlusal morphologies in a comprehensive sample of hominin fossils, including those coming from the Gran Dolina-TD6 and Sima de los Huesos sites from Atapuerca, Spain, complement previous works on lower first and second premolars and upper first molars. A morphological gradient consisting of the change from asymmetric to symmetric upper premolars and a marked reduction of the lingual cusp in recent Homo species has been observed in both premolars. Although percentages of correct classification based on upper premolar morphologies are not very high, significant morphological differences between Neanderthals (and European middle Pleistocene fossils) and modern humans have been identified, especially in upper second premolars. The study of morphological integration between premolar morphologies reveals significant correlations that are weaker between upper premolars than between lower ones and significant correlations between antagonists. These results have important implications for understanding the genetic and functional factors underlying dental phenotypic variation and covariation. Copyright © 2011 Elsevier Ltd. All rights reserved.

  12. Introgressive hybridization in southern African baboons shapes patterns of mtDNA variation.

    Science.gov (United States)

    Keller, C; Roos, C; Groeneveld, L F; Fischer, J; Zinner, D

    2010-05-01

    Species, as main evolutionary units have long been considered to be morphological entities with limited hybridization potential. The occurrence of taxa which maintain morphological distinctness despite extensive hybridization is an interesting phenomenon. To understand the evolution of these taxa, descriptions of contemporary morphological and genetic variation are essential, also to reconstruct sound phylogenies. Baboons, with their wide geographic range, variant morphotypes, and extensive hybridization offer an intriguing model for those studies. We focus on the complex situation in southern Africa that, in contrast to east Africa, has been neglected in terms of baboon hybridization history. We aim to clarify the distribution and identify possible overlapping zones between different, previously described mitochondrial (mt) DNA clades of baboons that do not match with the ranges of traditionally recognized species. On the basis of the widespread sampling and mitochondrial cytochrome b gene sequencing, we constructed a phylogenetic tree that separates representatives of the two southern African baboon species, yellow and chacma baboons, into six clades: southern, northern and eastern chacmas, Kinda baboons and southern and Luangwa yellow baboons. The ranges of the chacma clades come into close contact or overlap in two regions in the Republic of South Africa and Namibia. Our phylogenetic reconstruction reveals mitochondrial paraphyly for chacma and yellow baboons, which is probably caused by introgressive hybridization and subsequent nuclear swamping, whereby males of the chacma morphotype population from the south invaded the yellow morphotype population in the north bringing their morphotype into a population that maintained its yellow baboon mtDNA.

  13. Evolutionary history shapes the association between developmental instability and population-level genetic variation in three-spined sticklebacks.

    Science.gov (United States)

    Van Dongen, S; Lens, L; Pape, E; Volckaert, F A M; Raeymaekers, J A M

    2009-08-01

    Developmental instability (DI) is the sensitivity of a developing trait to random noise and can be measured by degrees of directionally random asymmetry [fluctuating asymmetry (FA)]. FA has been shown to increase with loss of genetic variation and inbreeding as measures of genetic stress, but associations vary among studies. Directional selection and evolutionary change of traits have been hypothesized to increase the average levels of FA of these traits and to increase the association strength between FA and population-level genetic variation. We test these two hypotheses in three-spined stickleback (Gasterosteus aculeatus L.) populations that recently colonized the freshwater habitat. Some traits, like lateral bone plates, length of the pelvic spine, frontal gill rakers and eye size, evolved in response to selection regimes during colonization. Other traits, like distal gill rakers and number of pelvic fin rays, did not show such phenotypic shifts. Contrary to a priori predictions, average FA did not systematically increase in traits that were under presumed directional selection, and the increases observed in a few traits were likely to be attributable to other factors. However, traits under directional selection did show a weak but significantly stronger negative association between FA and selectively neutral genetic variation at the population level compared with the traits that did not show an evolutionary change during colonization. These results support our second prediction, providing evidence that selection history can shape associations between DI and population-level genetic variation at neutral markers, which potentially reflect genetic stress. We argue that this might explain at least some of the observed heterogeneities in the patterns of asymmetry.

  14. Improved CT-based estimate of pulmonary gas trapping accounting for scanner and lung-volume variations in a multicenter asthmatic study.

    Science.gov (United States)

    Choi, Sanghun; Hoffman, Eric A; Wenzel, Sally E; Castro, Mario; Lin, Ching-Long

    2014-09-15

    Lung air trapping is estimated via quantitative computed tomography (CT) using density threshold-based measures on an expiration scan. However, the effects of scanner differences and imaging protocol adherence on quantitative assessment are known to be problematic. This study investigates the effects of protocol differences, such as using different CT scanners and breath-hold coaches in a multicenter asthmatic study, and proposes new methods that can adjust intersite and intersubject variations. CT images of 50 healthy subjects and 42 nonsevere and 52 severe asthmatics at total lung capacity (TLC) and functional residual capacity (FRC) were acquired using three different scanners and two different coaching methods at three institutions. A fraction threshold-based approach based on the corrected Hounsfield unit of air with tracheal density was applied to quantify air trapping at FRC. The new air-trapping method was enhanced by adding a lung-shaped metric at TLC and the lobar ratio of air-volume change between TLC and FRC. The fraction-based air-trapping method is able to collapse air-trapping data of respective populations into distinct regression lines. Relative to a constant value-based clustering scheme, the slope-based clustering scheme shows the improved performance and reduced misclassification rate of healthy subjects. Furthermore, both lung shape and air-volume change are found to be discriminant variables for differentiating among three populations of healthy subjects and nonsevere and severe asthmatics. In conjunction with the lung shape and air-volume change, the fraction-based measure of air trapping enables differentiation of severe asthmatics from nonsevere asthmatics and nonsevere asthmatics from healthy subjects, critical for the development and evaluation of new therapeutic interventions. Copyright © 2014 the American Physiological Society.

  15. Improved CT-based estimate of pulmonary gas trapping accounting for scanner and lung-volume variations in a multicenter asthmatic study

    Science.gov (United States)

    Choi, Sanghun; Hoffman, Eric A.; Wenzel, Sally E.; Castro, Mario

    2014-01-01

    Lung air trapping is estimated via quantitative computed tomography (CT) using density threshold-based measures on an expiration scan. However, the effects of scanner differences and imaging protocol adherence on quantitative assessment are known to be problematic. This study investigates the effects of protocol differences, such as using different CT scanners and breath-hold coaches in a multicenter asthmatic study, and proposes new methods that can adjust intersite and intersubject variations. CT images of 50 healthy subjects and 42 nonsevere and 52 severe asthmatics at total lung capacity (TLC) and functional residual capacity (FRC) were acquired using three different scanners and two different coaching methods at three institutions. A fraction threshold-based approach based on the corrected Hounsfield unit of air with tracheal density was applied to quantify air trapping at FRC. The new air-trapping method was enhanced by adding a lung-shaped metric at TLC and the lobar ratio of air-volume change between TLC and FRC. The fraction-based air-trapping method is able to collapse air-trapping data of respective populations into distinct regression lines. Relative to a constant value-based clustering scheme, the slope-based clustering scheme shows the improved performance and reduced misclassification rate of healthy subjects. Furthermore, both lung shape and air-volume change are found to be discriminant variables for differentiating among three populations of healthy subjects and nonsevere and severe asthmatics. In conjunction with the lung shape and air-volume change, the fraction-based measure of air trapping enables differentiation of severe asthmatics from nonsevere asthmatics and nonsevere asthmatics from healthy subjects, critical for the development and evaluation of new therapeutic interventions. PMID:25103972

  16. Stroke volume variation does not predict fluid responsiveness in patients with septic shock on pressure support ventilation

    DEFF Research Database (Denmark)

    Perner, A; Faber, T

    2006-01-01

    Stroke volume variation (SVV)--as measured by the pulse contour cardiac output (PiCCO) system--predicts the cardiac output response to a fluid challenge in patients on controlled ventilation. Whether this applies to patients on pressure support ventilation is unknown.......Stroke volume variation (SVV)--as measured by the pulse contour cardiac output (PiCCO) system--predicts the cardiac output response to a fluid challenge in patients on controlled ventilation. Whether this applies to patients on pressure support ventilation is unknown....

  17. Model studies of the solar limb shape variation with wavelenght within the PICARD project.

    Science.gov (United States)

    Melo, Stella M. L.; Thuillier, Gerard; Claudel, Jennyfer; Haberreiter, Margit; Mein, Nicole; Schmutz, Werner; Shapiro, Alexander; Sofia, Sabatino; Short, Christopher I.

    Solar images in the visible wavelength range show that the disk centre is brighter than the limb region. This phenomenon, which is both known as "centre to limb variation (CLV)", or "limb darkening function", is know to depend on wavelength. Since the CLV is determined by the density and temperature stratification, as well as the chemical composition of the so-lar photosphere, its measurement is important to validate theoretical assumption made when building numerical models of the solar atmosphere. The definition of the solar diameter is nor-mally adopted as the separation between two inflection points at opposite ends of a line passing through the center of the solar disk. Therefore, in order to understand long term variability on the solar diameter, it is important to understand what drives the dependence of the position of the inflection point on wavelength. In this paper we use different available solar atmosphere models to study this dependence. The results presented here refer to quiet Sun conditions and encompass the visible and near infra-red spectral regions, which are the regions of interest for the PICARD Satellite Mission. In a first step we utilize the solar atmosphere parameters with a radiative transfer code. This allows for the study of the impact of different factors such as opacities, electron density and temperature from different models on the results. Then, we compare results obtained using each solar atmosphere model. Our results are compared with existent ground based measurements performed by the Pic du Midi telescope, the balloon board measurements with the Solar Disk Sextant experiment, and with the measurements by the Michelson Doppler Imager on board SoHO satellite. The model simulations show that the position of the inflection point is sensitive to the different parameters and model assumptions. Furthermore, our study shows, for the first time, that the position of the inflection point changes dramatically with and outside of

  18. Three-Dimensional Hysterosalpingo Contrast Sonography with Gel Foam: Methodology and Feasibility to Obtain 3-Dimensional Volumes of Tubal Shape.

    Science.gov (United States)

    Exacoustos, Caterina; Pizzo, Alessandra; Lazzeri, Lucia; Pietropolli, Adalgisa; Piccione, Emilio; Zupi, Errico

    To investigate the feasibility of hysterosalpingo foam sonography (HyFoSy) with automated 3-dimensional (3D) software in the evaluation of tubal patency and visualization of the tubal course by obtaining a 3D volume acquisition of tubes. Prospective observational study (Canadian Task Force classification III). University hospital. A total of 132 infertile females evaluated between October 2013 and February 2015. All patients underwent HyFoSy with the new automated 3D coded contrast imaging (CCI) followed by 2-dimensional (2D) real-time HyFoSy. To evaluate the feasibility of 3D visualization of the tubal course, consecutive volume acquisitions were performed during gel foam contrast agent injection. Conventional 2D real-time hysterosalpingo contrast sonography (HyCoSy) by detection of gel foam moving through the tubes and around the ovaries was finally performed and considered to indicate the final results of tubal status. All the patients underwent 3D CCI HyFoSy, followed by 2D real-time HyFoSy. After both procedures, we observed 108 patients (81.8%) with bilateral tubal patency, 22 patients (16.6%) with unilateral tubal patency, and 2 patients (1.5%) with bilateral tubal occlusion. The concordance rate for tubal status between the first and second 3D volume acquisitions and the final 2D real-time evaluation was 84.8% and 97.0%, respectively. Transvaginal ultrasound HyFoSy with 3D volume reconstruction of the uterus and tubes is an accurate and safe technique that allows complete visualization of tubal shape and patency with high patient compliance. Copyright © 2017 AAGL. Published by Elsevier Inc. All rights reserved.

  19. Comparative study of pressure- and volume-controlled ventilation on stroke volume variation as a predictor of fluid responsiveness in patients undergoing major abdominal surgery.

    Science.gov (United States)

    Lee, Ji Yeon; Park, Hee Yeon; Jung, Wol Seon; Jo, Youn Yi; Kwak, Hyun Jeong

    2012-10-01

    We hypothesized that the 2 ventilation modes might have a different influence on the stroke volume variation (SVV). This study investigated the effect of the ventilation modes on SVV as a predictor of fluid responsiveness during major abdominal surgery. Sixty patients were randomly allocated to volume-controlled ventilation (VCV, n = 30) or pressure-controlled ventilation (PCV, n = 30) modes. After the induction of anesthesia, hemodynamic variables and SVV were measured before and after volume expansion (VE) with colloid solution of 10 mL/kg. The ability of SVV to predict the fluid responsiveness was tested by calculation of the area under a receiver operating characteristic curve for an increase in stroke volume index of at least 15% after VE. There were 10 and 16 responders in the VCV and PCV groups, respectively. The area under a receiver operating characteristic curve (95% confidence interval) for SVV before VE was 0.723 (0.538-0.907) and 0.799 (0.625-0.973) in the VCV and PCV groups, respectively. The optimal threshold value of SVV was 11% and 14% in the VCV and PCV groups, respectively. Stroke volume variation can predict fluid responsiveness during both VCV and PCV modes. However, the optimal threshold values of SVV may differ according to the ventilation modes. Copyright © 2012 Elsevier Inc. All rights reserved.

  20. Variation in genomic methylation in natural populations of Populus simonii is associated with leaf shape and photosynthetic traits.

    Science.gov (United States)

    Ci, Dong; Song, Yuepeng; Du, Qingzhang; Tian, Min; Han, Shuo; Zhang, Deqiang

    2016-02-01

    DNA methylation, one of the best-studied types of chromatin modification, suppresses the expression of transposable elements, pseudogenes, repetitive sequences, and individual genes. However, the extent and variation of genome-wide DNA methylation in natural populations of plants remain relatively unknown. To investigate variation in DNA methylation and whether this variation associates with important plant traits, including leaf shape and photosynthesis, 20 413 DNA methylation sites were examined in a poplar association population (505 individuals) using methylation-sensitive amplification polymorphism (MSAP) technology. Calculation of epi-population structure and kinships assigned individuals into subsets (K=3), revealing that the natural population of P. simonii consists of three subpopulations. Population epigenetic distance and geographic distance showed a significant correlation (r=0.4688, Pfactors may affect epigenetics. Single-marker approaches were also used to identify significant marker-trait associations, which found 1087 high-confidence DNA methylation markers associated with different phenotypic traits explaining ~5-15% of the phenotypic variance. Among these loci, 147 differentially methylated fragments were obtained by sequencing, representing 130 candidate genes. Expression analysis of six candidate genes indicated that these genes might play important roles in leaf development and regulation of photosynthesis. This study provides association analysis to study the effects of DNA methylation on plant development and these data indicate that epigenetics bridges environmental and genetic factors in affecting plant growth and development. © The Author 2015. Published by Oxford University Press on behalf of the Society for Experimental Biology. All rights reserved. For permissions, please email: journals.permissions@oup.com.

  1. GEOGRAPHIC BODY SIZE AND SHAPE VARIATION IN A MAINLAND Anolis (SQUAMATA: DACTYLOIDAE FROM NORTHWESTERN SOUTH AMERICA (COLOMBIA

    Directory of Open Access Journals (Sweden)

    Marta Lucia Calderón- Espinosa

    2014-03-01

    Full Text Available Normal 0 21 false false false ES-CO JA X-NONE Anolis auratus is a widely distributed species, from Costa Rica in Central America, through northern South America, includingColombia, Venezuela, northern Brazil, Surinam and the Guyanas. In Colombia, its widespread distribution across different life zones suggests that these lizards occupy different environments and exhibit different microhabitat use in different geographic areas. On the other hand, some observations suggest that this species prefers open areas, selecting grasslands over brushy areas, and thus, an alternative hypothesis is that microhabitat use is similar among different populations. In Anolis, body variables related to locomotion (body size and shape define structural microhabitat use, so two distinct patterns could be expected in this species: conservative or highly variable body size and shape throughout the species distribution. To test thesepredictions, we characterized geographic variation in morphometric traits of this species in Colombia. Females and males were similar in body size, but exhibited differences in some variables related to body shape. These characteristics also varied among males and females from different regions, suggesting heterogeneous use of structural microhabitat, between sexes and among populations. As an alternative, phylogenetic divergence among populations could also account for the observed differences. Absence of ecological and phylogenetic data limits our ability to identify the underlying causes of this pattern. However, we provide a general framework to explore hypotheses about evolution of body size and shape in this species.Variación geográfica en tamaño y forma corporalen un Anolis (Squamata: Dactyloidae continentaldel noroeste de Suramérica (ColombiaRESUMENAnolis auratus se distribuye desde Costa Rica en Centro América, el norte de Sur América, incluyendo Colombia, Venezuela, norte de Brasil, Surinam y las Guyanas. En

  2. Stroke volume variation does not predict fluid responsiveness in patients with septic shock on pressure support ventilation

    DEFF Research Database (Denmark)

    Perner, A; Faber, T

    2006-01-01

    Stroke volume variation (SVV)--as measured by the pulse contour cardiac output (PiCCO) system--predicts the cardiac output response to a fluid challenge in patients on controlled ventilation. Whether this applies to patients on pressure support ventilation is unknown....

  3. Evaluation of stroke volume variation obtained by arterial pulse contour analysis to predict fluid responsiveness intraoperatively.

    Science.gov (United States)

    Lahner, D; Kabon, B; Marschalek, C; Chiari, A; Pestel, G; Kaider, A; Fleischmann, E; Hetz, H

    2009-09-01

    Fluid management guided by oesophageal Doppler monitor has been reported to improve perioperative outcome. Stroke volume variation (SVV) is considered a reliable clinical predictor of fluid responsiveness. Consequently, the aim of the present trial was to evaluate the accuracy of SVV determined by arterial pulse contour (APCO) analysis, using the FloTrac/Vigileo system, to predict fluid responsiveness as measured by the oesophageal Doppler. Patients undergoing major abdominal surgery received intraoperative fluid management guided by oesophageal Doppler monitoring. Fluid boluses of 250 ml each were administered in case of a decrease in corrected flow time (FTc) to 10%. The ability of SVV to predict fluid responsiveness was assessed by calculation of the area under the receiver operating characteristic (ROC) curve. Twenty patients received 67 fluid boluses. Fifty-two of the 67 fluid boluses administered resulted in fluid responsiveness. SVV achieved an area under the ROC curve of 0.512 [confidence interval (CI) 0.32-0.70]. A cut-off point for fluid responsiveness was found for SVV > or =8.5% (sensitivity: 77%; specificity: 43%; positive predictive value: 84%; and negative predictive value: 33%). This prospective, interventional observer-blinded study demonstrates that SVV obtained by APCO, using the FloTrac/Vigileo system, is not a reliable predictor of fluid responsiveness in the setting of major abdominal surgery.

  4. Relationship between Stroke Volume Variation and Blood Transfusion during Liver Transplantation.

    Science.gov (United States)

    Choi, Jae Moon; Lee, Yoon Kyung; Yoo, Hwanhee; Lee, Sukyung; Kim, Hee Yeong; Kim, Young-Kug

    2016-01-01

    Intraoperative blood transfusion increases the risk for perioperative mortality and morbidity in liver transplant recipients. A high stroke volume variation (SVV) method has been proposed to reduce blood loss during living donor hepatectomy. Herein, we investigated whether maintaining high SVV could reduce the need for blood transfusion and also evaluated the effect of the high SVV method on postoperative outcomes in liver transplant recipients. We retrospectively analyzed 332 patients who underwent liver transplantation, divided into control (maintaining blood transfusion requirement and hemodynamic parameters, including SVV, as well as postoperative outcomes, such as incidences of acute kidney injury, durations of postoperative intensive care unit and hospital stay, and rates of 1-year mortality. Mean SVV values were 7.0% ± 1.3% in the control group (n = 288) and 11.2% ± 1.8% in the high SVV group (n = 44). The median numbers of transfused packed red blood cells and fresh frozen plasmas in the high SVV group were significantly lower than those in control group (0 vs. 2 units, P = 0.003; and 0 vs. 3 units, P = 0.033, respectively). No significant between-group differences were observed for postoperative outcomes. Maintaining high SVV can reduce the blood transfusion requirement during liver transplantation without worsening postoperative outcomes. These findings provide insights into improving perioperative management in liver transplant recipients.

  5. Interobserver variations of target volume delineation and its impact on irradiated volume in accelerated partial breast irradiation with intraoperative interstitial breast implant

    Directory of Open Access Journals (Sweden)

    Ritu Raj Upreti

    2017-02-01

    Full Text Available Purpose: To investigate the interobserver variations in delineation of lumpectomy cavity (LC and clinical target volume (CTV, and its impact on irradiated volume in accelerated partial breast irradiation using intraoperative multicatheter brachytherapy. Material and methods : Delineation of LC and CTV was done by five radiation oncologists on planning computed tomography (CT scans of 20 patients with intraoperative interstitial breast implant. Cavity visualization index (CVI, four-point index ranging from (0 = poor to (3 = excellent was created and assigned by observers for each patient. In total, 200 contours for all observers and 100 treatment plans were evaluated. Spatial concordance (conformity index, CI common , and CIgen, average shift in the center of mass (COM, and ratio of maximum and minimum volumes (V max /V min of LC and CTV were quantified among all observers and statistically analyzed. Variation in active dwell positions (0.5 cm step for each catheter, total reference air kerma (TRAK, volume enclosed by prescription isodose (V100% among observers and its spatial concordance were analyzed. Results : The mean ± SD CI common of LC and CTV was 0.54 ± 0.09, and 0.58 ± 0.08, respectively. Conformity index tends to increase, shift in COM and V max /V min decrease significantly (p < 0.05, as CVI increased. Out of total 309 catheters, 29.8% catheters had no change, 29.8% and 17.5% catheters had variations of 1 and 2 dwell positions (0.5 cm and 1 cm, respectively. 9.3% catheters shown variations ≥ 10 dwell positions (5 cm. The mean ± SD CI common of V100% was 0.75 ± 0.11. The mean observed V max /V min of prescription isodose and TRAK was 1.18 (range, 1.03 to 1.56 and 1.11 (range, 1.03 to 1.35, respectively. Conclusions : Interobserver variability in delineation of target volume was found to be significantly related to CVI. Smaller variability was observed with excellent visualization of LC. Interobserver variations showed dosimetric

  6. Effects of environmental disturbance on phenotypic variation: an integrated assessment of canalization, developmental stability, modularity, and allometry in lizard head shape.

    Science.gov (United States)

    Lazić, Marko M; Carretero, Miguel A; Crnobrnja-Isailović, Jelka; Kaliontzopoulou, Antigoni

    2015-01-01

    When populations experience suboptimal conditions, the mechanisms involved in the regulation of phenotypic variation can be challenged, resulting in increased phenotypic variance. This kind of disturbance can be diagnosed by using morphometric tools to study morphological patterns at different hierarchical levels and evaluate canalization, developmental stability, integration, modularity, and allometry. We assess the effect of urbanization on phenotypic variation in the common wall lizard (Podarcis muralis) by using geometric morphometrics to assess disturbance to head shape development. The head shapes of urban lizards were more variable and less symmetric, suggesting that urban living is more likely to disturb development. Head shape variation was congruent within and across individuals, which indicated that canalization and developmental stability are two related phenomena in these organisms. Furthermore, urban lizards exhibited smaller mean head sizes, divergent size-shape allometries, and increased deviation from within-group allometric lines. This suggests that mechanisms regulating head shape allometry may also be disrupted. The integrated evaluation of several measures of developmental instability at different hierarchical levels, which provided in this case congruent results, can be a powerful methodological guide for future studies, as it enhances the detection of environmental disturbances on phenotypic variation and aids biological interpretation of the results.

  7. Intraspecific variation in body size and shape in an Andean highland anole species, Anolis ventrimaculatus (Squamata: Dactyloidae

    Directory of Open Access Journals (Sweden)

    Martha L. Calderón-Espinosa

    2013-03-01

    Full Text Available Variation in body characteristics related to lizard locomotion has been poorly studied at the intraspecific level in Anolis species. Local adaptation due to habitat heterogeneity has been reported in some island species. However, studies of mainland species are particularly scarce and suggest different patterns: high variability among highland lizards and poorly differentiated populations in one Amazonian species. We characterized inter population variation of body size and shape in the highland Andean Anolis ventrimaculatus, an endemic species from Western Colombia. A total of 15 morphometric variables were measured in specimens from the reptile collection of the Instituto de Ciencias Naturales, Universidad Nacional, Colombia. The study included individuals from seven different highland localities. We found size and shape sexual dimorphism, both of which varied among localities. Patterns of variation in body proportions among populations were different in both males and females, suggesting that either sexual or natural selective factors are different in each locality and between sexes. Since this species exhibits a fragmented distribution in highlands, genetic divergence may also be a causal factor of the observed variation. Ecological, behavioral, additional morphological as well as phylogenetic data, may help to understand the evolutionary processes behind the geographic patterns found in this species.La diversificación fenotípica al interior de una especie en características de dimensiones corporales relacionadas con la locomoción de los lagartos, se ha estudiado poco en especies de Anolis. Los datos de algunas especies de isla revelan patrones distintos de variación geográfica y sugieren que la adaptación local, debida a la heterogeneidad del hábitat, ocurre a este nivel. Los estudios de especies de continente son particularmente escasos y sugieren patrones distintos: un lagarto altoandino altamente variable y poblaciones poco

  8. Racial differences in hemoglobin and plasma volume variation: implications for muscle performance and recovery.

    Science.gov (United States)

    Sellami, Maha; Chamari, Karim; Zagatto, Alessandro Moura; Kebsi, Wiem; Chaouachi, Anis; Zouhal, Hassane

    2017-04-10

    To examine the effect of race differences on sprint performance, Hemoglobin (Hb), Hematocrit (Ht) and plasma volume (PV) variation in response to repeated sprint exercise. Thirty-six healthy, moderately trained men and women (20.8 ± 0.2 year-old) volunteered to participate in this study. They were allocated to one of the four groups according to their gender and race: Black men's group (BM, n = 9), White men's group (WM, n = 9), Black women's group (BW, n = 9) and White women's group (WW, n = 9). All participants performed the running-based anaerobic sprint test (RAST), which consists of six 35-m sprints with 10 s of recovery in-between. Six venous blood samples were collected to determine Hb, Ht and PV levels at rest, after warm-up, immediately post- and at 5, 15 and 30 min post-RAST. Blood lactate is also sampled during the 3rd minutes of recovery. The best running time was significantly shorter (P = .002) in BW compared to WW. We have observed significantly higher Hb (P = .010) and Ht (P = .004) levels in BW compared to WW during the 5th minute of recovery. During RAST, the PV decreased significantly (P = .007) in WM only. Black groups had lower (P < .05) lactate levels compared to the white subjects. During recovery, PV increase was significantly (P = .003) higher in WW compared to BW during the 5th minute of recovery. This study demonstrated that sprint and repeated sprint performances were different between white and black women. Differences in anaerobic performance between the groups were associated with racial differences in lactate levels and blood count among women's group during recovery time. Hence, it is important to take into account this race-related difference in hematological parameters in responses to intense efforts.

  9. Does stroke volume variation predict fluid responsiveness in children: A systematic review and meta-analysis.

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    Ling Yi

    Full Text Available Stroke volume variation (SVV is a reliable predictor of fluid responsiveness in adult patients. However, the predictive value of SVV is uncertain in pediatric patients. We performed the first systematic meta-analysis to evaluate the diagnostic value of SVV in predicting fluid responsiveness in children.PUBMED, EMBASE, and Cochrane Central Register of Controlled Trials were searched up to December 2016. Original studies assessing the diagnostic accuracy of SVV in predicting fluid responsiveness in children were considered to be eligible. A random-effects model was used to calculate pooled values of sensitivity, specificity and diagnostic odds ratio with 95% CI. The summary receiver operating characteristic curve was estimated and area under the curve was calculated. Quality of the studies was assessed with the QUADAS-2 tool.Six studies with a total of 279 fluid boluses in 224 children were included. The analysis demonstrated a pooled sensitivity of 0.68 (95% CI,0.59-0.76, pooled specificity of 0.65 (95% CI, 0.57-0.73, pooled diagnostic odds ratio of 8.24 (95% CI, 2.58-26.30, and the summary area under the summary receiver operating characteristic curve of 0.81. However, significant inter-study heterogeneity was found (p<0.05, I2 = 61.3%, likely due to small sample size and diverse study characteristics.Current evidence suggests that SVV was of diagnostic value in predicting fluid responsiveness in children under mechanical ventilation. Given the high heterogeneity of published data, further studies are needed to confirm the diagnostic accuracy of SVV in predicting fluid responsiveness in pediatric patients.

  10. Lumbar Sagittal Shape Variation Vis-à-Vis Sex During Growth: A 3-Year Follow-up Magnetic Resonance Imaging Study in Children From the General Population

    DEFF Research Database (Denmark)

    Masharawi, Y; Kjær, Per; Manniche, C

    2012-01-01

    ABSTRACT: Study Design. A longitudinal descriptive MRI study on the changes of the supine lumbar lordosis (SLL), supine sacral slope (SSS), and sagittal wedging of the vertebral body (VB) and intervertebral discs (IVD) in children from the general population.Objective. To compare the shape variat...... correlations were indicated between puberty Tanner stage and individual's height and weight (0.41...

  11. Lumbar Sagittal Shape Variation vis-à-vis Gender During Growth: A Three-Year Follow-Up Mri Study in Children from the General Population

    DEFF Research Database (Denmark)

    Masharawi, Y; Kjaer, P; Manniche, C

    2012-01-01

    ABSTRACT: Study Design. A longitudinal descriptive MRI study on the changes of the supine lumbar lordosis (SLL), supine sacral slope (SSS), and sagittal wedging of the vertebral body (VB) and intervertebral discs (IVD) in children from the general population.Objective. To compare the shape variat...... correlations were indicated between puberty Tanner stage and individual's height and weight (0.41...

  12. Evaluation of stroke volume variation and pulse pressure variation as predictors of fluid responsiveness in patients undergoing protective one-lung ventilation.

    Science.gov (United States)

    Fu, Qiang; Duan, Mingda; Zhao, Feng; Mi, Weidong

    2015-08-01

    In order to investigate whether the hemodynamic indices, including stroke volume variation (SVV) and pulse pressure variation (PPV) could predict fluid responsiveness in patients undergoing protective one-lung ventilation. 60 patients scheduled for a combined thoracoscopic and laparoscopic esophagectomy were enrolled and randomized into two groups. The patients in the protective group (Group P) were ventilated with a tidal volume of 6 mL/kg, an inspired oxygen fraction (FiO2) of 80%, and a positive end expiratory pressure (PEEP) of 5 cm H2O. Patients in the conventional group (Group C) were ventilated with a tidal volume of 8 mL/kg and a FiO2 of 100%. Dynamic variables were collected before and after fluid loading (7 mL/kg hydroxyethyl starch 6%, 0.4 mL/kg/min). Patients whose stroke volume index (SVI) increased by more than 15% were defined as responders. Data collected from 45 patients were finally analyzed. Twelve of 24 patients in Group P and 10 of 21 patients in Group C were responders. SVV and PPV significantly changed after the fluid loading. The receive operating characteristic (ROC) analysis showed that the thresholds for SVV and PPV to discriminate responders were 8.5% for each, with a sensitivity of 66.7% (SVV) and 75% (PPV) and a specificity of 50% (SVV) and 83.3% (PPV) in Group P. However, the thresholds for SVV and PPV were 8.5% and 7.5% with a sensitivity of 80% (SVV) and 90% (PPV) and a specificity of 70% (SVV) and 80% (PPV) in Group C. We found SVV and PPV could predict fluid responsiveness in protective one-lung ventilation, but the accuracy and ability of SVV and PPV were weak compared with the role they played in a conventional ventilation strategy.

  13. The Compositional Variation of Microindentation Induced Densified and Plastic Deformation Volumes in Simple Silicate Glasses

    DEFF Research Database (Denmark)

    Hermansen, Christian; Matsuoka, Jun; Yoshida, Satoshi

    2012-01-01

    credence to the empirical correlation between hardness and elastic moduli. The plastic deformation volume was not measurable up to a modifying oxide fraction of 20%, but was found to increase linearly with this fraction above 20%. As the plastically induced stress is thought to be the cause of radial...... deformed volumes under microindentation in simple silicate glasses by AFM imaging the indent before and after annealing around the glass transition temperature at which the densified volume rapidly relaxes. The results show that the densified volume is inversely proportional to the bulk modulus, lending...

  14. Evaluation of the Efficacy of Standardized Uptake Value (SUV-shape Scheme for Thyroid Volume Determination in Graves’ Disease: A Comparison with Ultrasonography

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    yangchun chen

    2017-01-01

    Full Text Available Objective(s: In this study, we aimed to evaluate the efficacy of thyroid volume measurement using 99mTc pertechnetate single-photon emission computed tomography (SPECT images, acquired by the standardized uptake value (SUV-shape scheme designed by our expert team.Methods: A total of 18 consecutive patients with Graves’ disease (GD were subjected to both ultrasonographic and 99mTc pertechnetate SPECT examinations of thyroid within a five-day interval. The volume of thyroid lobes and isthmus was measured by ultrasonography (US according to the ellipsoid volume equation. The total thyroid volume, determined as the sum of the volume of both lobes and isthmus, was recorded as TV-US (i.e., thyroid volume measured by US and set as the reference. The thyroid volume was defined according to our SUV-shape scheme and was recorded as TV-SS (i.e., thyroid volume determined by the SUV-shape scheme. The data were analyzed using the Bland-Altman plot, linear regression analysis, Spearman’s rank correlation, and paired t-test, if necessary.Results: The values of TV-SS (40.2±29.4 mL and TV-US (43.0±34.7 mL were not significantly different (t=0.813; P=0.43. The linear regression equation of the two values was determined as TV-US= 1.072 × TV-SS − 0.29(r=0.906; P

  15. Lung nodule volume quantification and shape differentiation with an ultra-high resolution technique on a photon counting detector CT system

    Science.gov (United States)

    Zhou, W.; Montoya, J.; Gutjahr, R.; Ferrero, A.; Halaweish, A.; Kappler, S.; McCollough, C.; Leng, S.

    2017-03-01

    A new ultra high-resolution (UHR) mode has been implemented on a whole body photon counting-detector (PCD) CT system. The UHR mode has a pixel size of 0.25 mm by 0.25 mm at the iso-center, while the conventional (macro) mode is limited to 0.5 mm by 0.5 mm. A set of synthetic lung nodules (two shapes, five sizes, and two radio-densities) was scanned using both the UHR and macro modes and reconstructed with 2 reconstruction kernels (4 sets of images in total). Linear regression analysis was performed to compare measured nodule volumes from CT images to reference volumes. Surface curvature was calculated for each nodule and the full width half maximum (FWHM) of the curvature histogram was used as a shape index to differentiate sphere and star shape nodules. Receiver operating characteristic (ROC) analysis was performed and area under the ROC curve (AUC) was used as a figure of merit for the differentiation task. Results showed strong linear relationship between measured nodule volume and reference standard for both UHR and macro mode. For all nodules, volume estimation was more accurate using UHR mode with sharp kernel (S80f), with lower mean absolute percent error (MAPE) (6.5%) compared with macro mode (11.1% to 12.9%). The improvement of volume measurement from UHR mode was more evident particularly for small nodule size (3mm, 5mm), or star-shape nodules. Images from UHR mode with sharp kernel (S80f) consistently demonstrated the best performance (AUC = 0.85) when separating star from sphere shape nodules among all acquisition and reconstruction modes. Our results showed the advantages of UHR mode on a PCD CT scanner in lung nodule characterization. Various clinical applications, including quantitative imaging, can benefit substantially from this high resolution mode.

  16. Impact of retinoic acid exposure on midfacial shape variation and manifestation of holoprosencephaly in Twsg1 mutant mice

    Directory of Open Access Journals (Sweden)

    Charles J. Billington

    2015-02-01

    Full Text Available Holoprosencephaly (HPE is a developmental anomaly characterized by inadequate or absent midline division of the embryonic forebrain and midline facial defects. It is believed that interactions between genes and the environment play a role in the widely variable penetrance and expressivity of HPE, although direct investigation of such effects has been limited. The goal of this study was to examine whether mice carrying a mutation in a gene encoding the bone morphogenetic protein (BMP antagonist twisted gastrulation (Twsg1, which is associated with a low penetrance of HPE, are sensitized to retinoic acid (RA teratogenesis. Pregnant Twsg1+/− dams were treated by gavage with a low dose of all-trans RA (3.75 mg/kg of body weight. Embryos were analyzed between embryonic day (E9.5 and E11.5 by microscopy and geometric morphometric analysis by micro-computed tomography. P19 embryonal carcinoma cells were used to examine potential mechanisms mediating the combined effects of increased BMP and retinoid signaling. Although only 7% of wild-type embryos exposed to RA showed overt HPE or neural tube defects (NTDs, 100% of Twsg1−/− mutants exposed to RA manifested severe HPE compared to 17% without RA. Remarkably, up to 30% of Twsg1+/− mutants also showed HPE (23% or NTDs (7%. The majority of shape variation among Twsg1+/− mutants was associated with narrowing of the midface. In P19 cells, RA induced the expression of Bmp2, acted in concert with BMP2 to increase p53 expression, caspase activation and oxidative stress. This study provides direct evidence for modifying effects of the environment in a genetic mouse model carrying a predisposing mutation for HPE in the Twsg1 gene. Further study of the mechanisms underlying these gene-environment interactions in vivo will contribute to better understanding of the pathogenesis of birth defects and present an opportunity to explore potential preventive interventions.

  17. It's just sand between the toes: how particle size and shape variation affect running performance and kinematics in a generalist lizard.

    Science.gov (United States)

    Bergmann, Philip J; Pettinelli, Kyle J; Crockett, Marian E; Schaper, Erika G

    2017-10-15

    Animals must cope with and be able to move effectively on a variety of substrates. Substrates composed of granular media, such as sand and gravel, are extremely common in nature, and vary tremendously in particle size and shape. Despite many studies of the properties of granular media and comparisons of locomotion between granular and solid substrates, the effects of systematically manipulating these media on locomotion is poorly understood. We studied granular media ranging over four orders of magnitude in particle size, and differing in the amount of particle shape variation, to determine how these factors affected substrate physical properties and sprinting in the generalist lizard Eremias arguta We found that media with intermediate particle sizes had high bulk densities, low angles of stability and low load-bearing capacities. Rock substrates with high shape variation had higher values for all three properties than glass bead substrates with low shape variation. We found that E. arguta had the highest maximum velocities and accelerations on intermediate size particles, and higher velocities on rock than glass beads. Lizards had higher stride frequencies and lower duty factors on intermediate particle size substrates, but their stride lengths did not change with substrate. Our findings suggest that sand and gravel may represent different locomotor challenges for animals. Sand substrates provide animals with an even surface for running, but particles shift underfoot. In contrast, gravel particles are heavy, so move far less underfoot, yet provide the animal with an uneven substrate. © 2017. Published by The Company of Biologists Ltd.

  18. Study of Prostatic Volume and its Variations in Different Age Groups of Bangladeshi Cadaver.

    Science.gov (United States)

    Epsi, E Z; Sultana, S Z; Mannan, S; Azam, A S; Choudhury, S; Ahmed, Z; Farjan, S; Kabir, A; Ismatsara, M; Yesmin, M; Zisa, R S; Khan, S H

    2016-10-01

    Benign prostatic hyperplasia and carcinoma of the prostate are the most common disorders of Bangladeshi male in recent years. Volume of the prostate is necessary to estimate the amount of BPH adenoma to determine the appropriate therapy or to select the surgical approach. Transurethral resection of prostate (TURP) is preferred for small glands and open prostatectomy for larger ones. Decrease in prostatic mass after hormonal manipulation or radiation therapy can be used as an indicator of therapeutic efficacy. The effect of prostate volume on biopsy outcome was assessed and was noted that there was an inverse relationship in between size of the gland and prostate cancer. A cross sectional descriptive study was conducted in Department of Anatomy, Mymensingh Medical College, Mymensingh, Bangladesh to find out the difference in volume of the prostate gland of Bangladeshi people in relation to age. The present study was performed on 67 postmortem human prostate gland collected from the morgue in the Department of Forensic Medicine, Mymensingh Medical College by non random purposive sampling technique. The specimens were collected from Bangladeshi cadaver of age ranging from 10 to 80 years. All the specimens were grouped into three categories: Group A (upto 18 years), Group B (19 to 45 years) and Group C (above 45 years) according to age. Dissection was performed according to standard autopsy techniques. The volume of the prostate gland were measured and recorded. The mean volume of the prostate gland was 13.75ml in Group A, 24.44ml in Group B and 29.72ml in Group C. Variance analysis shows that mean differences of volume of the prostate were highly significant among all age groups. The volume of prostate gland was found to be increased with increasing age. For statistical analysis, differences between age groups were analyzed by using students unpaired 't' test. The present study will help to increase the information pool on the volume of prostate gland of Bangladeshi

  19. Despite variation in volume, Veterans Affairs hospitals show consistent outcomes among patients with non-postoperative mechanical ventilation.

    Science.gov (United States)

    Cooke, Colin R; Kennedy, Edward H; Wiitala, Wyndy L; Almenoff, Peter L; Sales, Anne E; Iwashyna, Theodore J

    2012-09-01

    To assess the relationship between volume of nonoperative mechanically ventilated patients receiving care in a specific Veterans Health Administration hospital and their mortality. Retrospective cohort study. One-hundred nineteen Veterans Health Administration medical centers. We identified 5,131 hospitalizations involving mechanically ventilated patients in an intensive care unit during 2009, who did not receive surgery. None. We extracted demographic and clinical data from the VA Inpatient Evaluation Center. For each hospital, we defined volume as the total number of nonsurgical admissions receiving mechanical ventilation in an intensive care unit during 2009. We examined the hospital contribution to 30-day mortality using multilevel logistic regression models with a random intercept for each hospital. We quantified the extent of interhospital variation in 30-day mortality using the intraclass correlation coefficient and median odds ratio. We used generalized estimating equations to examine the relationship between volume and 30-day mortality and risk-adjusted all models using a patient-level prognostic score derived from clinical data representing the risk of death conditional on treatment at a high-volume hospital. Mean age for the sample was 65 (SD 11) yrs, 97% were men, and 60% were white. The median VA hospital cared for 40 (interquartile range 19-62) mechanically ventilated patients in 2009. Crude 30-day mortality for these patients was 36.9%. After reliability and risk adjustment to the median patient, adjusted hospital-level mortality varied from 33.5% to 40.6%. The intraclass correlation coefficient for the hospital-level variation was 0.6% (95% confidence interval 0.1, 3.4%), with a median odds ratio of 1.15 (95% confidence interval 1.06, 1.38). The relationship between hospital volume of mechanically ventilated and 30-day mortality was not statistically significant: each 50-patient increase in volume was associated with a nonsignificant 2% decrease in

  20. Seasonal variation in serum testosterone, testicular volume, and semen characteristics in the coyote (Canis latrans).

    Science.gov (United States)

    Minter, L J; DeLiberto, T J

    2008-05-01

    The coyote is a seasonally breeding mammal, with most copulations occurring between December and April (depending on location). The objective of this study was to characterize seasonal changes in serum testosterone concentrations, testicular volume, and ejaculate quantity and quality in captive male coyotes. There were seasonal differences in testicular volume, with the greatest volume (20.2+/-5.4cm2), mean+/-S.E.M.) in February, corresponding with peak breeding season. Circulating serum testosterone concentrations peaked (3.31+/-0.9 ng/mL) during January and were positively correlated (P< or =0.001, r=0.413) with testicular volume. Ejaculate volume (1.67+/-0.4 mL) and sperm concentration (549.2 x 10(6)+/-297.7 spermatozoa/mL) both peaked during January and February, consistent with the height of the breeding season. Ejaculate volume and sperm concentrations were positively correlated with testicular size (r=0.679, P< or =0.001 and r=0.499, P< or =0.001, respectively) and with serum testosterone concentrations (r=0.368, P< or =0.01 and r=0.208, P< or =0.05). Progressively motile, viable, and morphologically normal spermatozoa fluctuated seasonally, peaked (90.4+/-4.5, 84.8+/-4.1, and 87.9+/-2.9%) during the breeding season, and then subsequently declined (period of aspermatogenesis). All three of these end points were positively correlated with testicular size (r=0.589, P< or =0.001; r=0.586, P< or =0.001; and r=0.469; P< or =0.001) and serum testosterone (r=0.167, P< or =0.05; r=0.190, P< or =0.05; and r=0.221, P< or =0.01). In conclusion, there were intricate relationships among testosterone concentrations, testicular volume, and the production of both functionally intact and morphologically normal spermatozoa.

  1. Spatial variability of the physical and mineralogical properties of the soil from the areas with variation in landscape shapes

    Directory of Open Access Journals (Sweden)

    Zigomar Menezes de Souza

    2009-04-01

    Full Text Available The objective of this work it was to use the geostatistics methods to investigate the spatial relationships between the physical and mineralogical properties of an oxisol planted with the sugarcane in an area of slight variations in the landform. The soil was sampled at 10 m regular intervals in the crossing points of a 100 x 100 m grid. At each point, the soil was collected at 0.0-0.2 m, 0.2-0.4 m and 0.4-0.6 m depths for the analyzes of physical properties and at 0.6-0.8 m for the mineralogical analyses. Both the Kt/Kt+Gb ratio and Kt relative crystallization level were higher in the compartment I than in the compartment II. As a consequence, the soil penetration resistance and bulk density were higher in the compartment I, while the macroporosity and Ksat were lower. Therefore, it was concluded that both the identification and mapping of a landform were efficient for understanding the spatial variability of the soil properties. Moreover, variations in the landscape shape promoted the differentiated variability of the physical and mineralogical soil properties: the more variable the landscape, the more variable was the soil properties.Este trabalho teve como objetivo avaliar a influência das formas do relevo na variabilidade espacial de atributos físicos e suas relações com a mineralogia da argila de um Latossolo Vermelho eutroférrico, utilizando a técnica da geoestatística. Os solos foram amostrados nos pontos de cruzamento de uma malha, com intervalos regulares de 10 m, nas profundidades de 0,0-0,2 m, 0,2-0,4 m e 0,4-0,6 m para os atributos físicos e 0,6-0,8 m para os atributos mineralógicos. Os valores médios para a densidade do solo e resistência do solo à penetração são maiores no compartimento I onde a relação Ct/Ct+Gb é relativamente maior, indicando a presença de maior teor de caulinita. No compartimento II a condutividade hidráulica e a macroporsidade são maiores, influenciados provavelmente pelo predomínio da

  2. Lake volume and groundwater storage variations in Tibetan Plateau's endorheic basin

    Science.gov (United States)

    Zhang, Guoqing; Yao, Tandong; Shum, C. K.; Yi, Shuang; Yang, Kun; Xie, Hongjie; Feng, Wei; Bolch, Tobias; Wang, Lei; Behrangi, Ali; Zhang, Hongbo; Wang, Weicai; Xiang, Yang; Yu, Jinyuan

    2017-06-01

    The Tibetan Plateau (TP), the highest and largest plateau in the world, with complex and competing cryospheric-hydrologic-geodynamic processes, is particularly sensitive to anthropogenic warming. The quantitative water mass budget in the TP is poorly known. Here we examine annual changes in lake area, level, and volume during 1970s-2015. We find that a complex pattern of lake volume changes during 1970s-2015: a slight decrease of -2.78 Gt yr-1 during 1970s-1995, followed by a rapid increase of 12.53 Gt yr-1 during 1996-2010, and then a recent deceleration (1.46 Gt yr-1) during 2011-2015. We then estimated the recent water mass budget for the Inner TP, 2003-2009, including changes in terrestrial water storage, lake volume, glacier mass, snow water equivalent (SWE), soil moisture, and permafrost. The dominant components of water mass budget, namely, changes in lake volume (7.72 ± 0.63 Gt yr-1) and groundwater storage (5.01 ± 1.59 Gt yr-1), increased at similar rates. We find that increased net precipitation contributes the majority of water supply (74%) for the lake volume increase, followed by glacier mass loss (13%), and ground ice melt due to permafrost degradation (12%). Other term such as SWE (1%) makes a relatively small contribution. These results suggest that the hydrologic cycle in the TP has intensified remarkably during recent decades.

  3. Variations of comoving volume and their effects on the star formation rate density

    Science.gov (United States)

    Kim, Sungeun; Physics and Astronomy, Sejong University, Seoul, Korea (the Republic of).

    2018-01-01

    To build a comprehensive picture of star formation in the universe, we havedeveloped an application to calculate the comoving volume at a specific redshift and visualize the changes of spaceand time. The application is based on the star formation rates of about a few thousands of galaxies and their redshiftvalues. Three dimensional modeling of these galaxies using the redshift, comoving volume, and star formation ratesas input data allows calculation of the star formation rate density corresponding to the redshift. This work issupported by the National Research Foundation of Korea (NRF) grant funded by the Korea government (MSIP)(no. 2017037333).

  4. Goal-directed intraoperative fluid therapy guided by stroke volume and its variation in high-risk surgical patients : a prospective randomized multicentre study

    NARCIS (Netherlands)

    Scheeren, Thomas W. L.; Wiesenack, Christoph; Gerlach, Herwig; Marx, Gernot

    Perioperative hemodynamic optimisation improves postoperative outcome for patients undergoing high-risk surgery (HRS). In this prospective randomized multicentre study we studied the effects of an individualized, goal-directed fluid management based on continuous stroke volume variation (SVV) and

  5. Variation in neoadjuvant chemotherapy utilization for epithelial ovarian cancer at high volume hospitals in the United States and associated survival.

    Science.gov (United States)

    Barber, Emma L; Dusetzina, Stacie B; Stitzenberg, Karyn B; Rossi, Emma C; Gehrig, Paola A; Boggess, John F; Garrett, Joanne M

    2017-06-01

    To estimate variation in the use of neoadjuvant chemotherapy by high volume hospitals and to determine the association between hospital utilization of neoadjuvant chemotherapy and survival. We identified incident cases of stage IIIC or IV epithelial ovarian cancer in the National Cancer Database from 2006 to 2012. Inclusion criteria were treatment at a high volume hospital (>20 cases/year) and treatment with both chemotherapy and surgery. A logistic regression model was used to predict receipt of neoadjuvant chemotherapy based on case-mix predictors (age, comorbidities, stage etc). Hospitals were categorized by the observed-to-expected ratio for neoadjuvant chemotherapy use as low, average, or high utilization hospitals. Survival analysis was performed. We identified 11,574 patients treated at 55 high volume hospitals. Neoadjuvant chemotherapy was used for 21.6% (n=2494) of patients and use varied widely by hospital, from 5%-55%. High utilization hospitals (n=1910, 10 hospitals) had a median neoadjuvant chemotherapy rate of 39% (range 23-55%), while low utilization hospitals (n=2671, 14 hospitals) had a median rate of 10% (range 5-17%). For all ovarian cancer patients adjusting for clinical and socio-demographic factors, treatment at a hospital with average or high neoadjuvant chemotherapy utilization was associated with a decreased rate of death compared to treatment at a low utilization hospital (HR 0.90 95% CI 0.83-0.97 and HR 0.85 95% CI 0.75-0.95). Wide variation exists in the utilization of neoadjuvant chemotherapy to treat stage IIIC and IV epithelial ovarian cancer even among high volume hospitals. Patients treated at hospitals with low rates of neoadjuvant chemotherapy utilization experience decreased survival. Copyright © 2017 Elsevier Inc. All rights reserved.

  6. Variation in Nectar Volume and Sugar Concentration of Allium ursinum L. ssp. ucrainicum in Three Habitats

    Directory of Open Access Journals (Sweden)

    Ágnes Farkas

    2012-01-01

    Full Text Available Floral nectar volume and concentration of ramson (Allium ursinum L. ssp. ucrainicum were investigated in three different habitats, including two types of sessile oak-hornbeam association on brown forest soil with clay illuviation and a silver lime-flowering ash rock forest association on rendzina. Daily nectar production ranged from 0.1 to 3.8 μL per flower with sugar concentrations of 25 to 50%. Mean nectar volumes and concentrations showed significant differences between freely exposed flowers and covered flowers, which had been isolated from flower visitors 24 h prior to nectar studies. Both the amount and quality of nectar were affected by microclimatic conditions and soil properties and varied between populations at different habitats. In the silver lime-flowering ash rock-forest association mean nectar volumes and concentrations were lower than in a typical sessile oak-hornbeam association on three occasions, the difference being significant in two cases. During full bloom, the date of sampling did not have a profound effect on either nectar volume or concentration.

  7. Variations in gastric compliance induced by acute blood volume changes in anesthetized rats

    Directory of Open Access Journals (Sweden)

    Graça J.R.V.

    2002-01-01

    Full Text Available The impact of acute volume imbalances on gastric volume (GV was studied in anesthetized rats (250-300 g. After cervical and femoral vessel cannulation, a balloon catheter was positioned in the proximal stomach. The opposite end of the catheter was connected to a barostat with an electronic sensor coupled to a plethysmometer. A standard ionic solution was used to fill the balloon (about 3.0 ml and the communicating vessel system, and to raise the reservoir liquid level 4 cm above the animals' xiphoid appendix. Due to constant barostat pressure, GV values were considered to represent the gastric compliance index. All animals were monitored for 90 min. After a basal interval, they were randomly assigned to normovolemic, hypervolemic, hypovolemic or restored protocols. Data were compared by ANOVA followed by Bonferroni's test. Mean arterial pressure (MAP, central venous pressure (CVP and GV values did not change in normovolemic animals (N = 5. Hypervolemic animals (N = 12 were transfused at 0.5 ml/min with a suspension of red blood cells in Ringer-lactate solution with albumin (12.5 ml/kg, which reduced GV values by 11.3% (P0.05. MAP and CVP values increased (P<0.05 after hypervolemia but decreased (P<0.05 with hypovolemia. In conclusion, blood volume level modulates gastric compliance, turning the stomach into an adjustable reservoir, which could be part of the homeostatic process to balance blood volume.

  8. VARIATION OF LUNG DEPOSITION OF MICRON SIZE PARTICLES WITH LUNG VOLUME AND BREATHING PATTERN

    Science.gov (United States)

    Lung volume and breathing pattern are the source of inter-and intra-subject variability of lung deposition of inhaled particles. Controlling these factors may help optimize delivery of aerosol medicine to the target site within the lung. In the present study we measured total lu...

  9. Non-invasive measurements of pulse pressure variation and stroke volume variation in anesthetized patients using the Nexfin blood pressure monitor.

    Science.gov (United States)

    Stens, Jurre; Oeben, Jeroen; Van Dusseldorp, Ab A; Boer, Christa

    2016-10-01

    Nexfin beat-to-beat arterial blood pressure monitoring enables continuous assessment of hemodynamic indices like cardiac index (CI), pulse pressure variation (PPV) and stroke volume variation (SVV) in the perioperative setting. In this study we investigated whether Nexfin adequately reflects alterations in these hemodynamic parameters during a provoked fluid shift in anesthetized and mechanically ventilated patients. The study included 54 patients undergoing non-thoracic surgery with positive pressure mechanical ventilation. The provoked fluid shift comprised 15° Trendelenburg positioning, and fluid responsiveness was defined as a concomitant increase in stroke volume (SV) >10 %. Nexfin blood pressure measurements were performed during supine steady state, Trendelenburg and supine repositioning. Hemodynamic parameters included arterial blood pressure (MAP), CI, PPV and SVV. Trendelenburg positioning did not affect MAP or CI, but induced a decrease in PPV and SVV by 3.3 ± 2.8 and 3.4 ± 2.7 %, respectively. PPV and SVV returned back to baseline values after repositioning of the patient to baseline. Bland-Altman analysis of SVV and PPV showed a bias of -0.3 ± 3.0 % with limits of agreement ranging from -5.6 to 6.2 %. The SVV was more superior in predicting fluid responsiveness (AUC 0.728) than the PVV (AUC 0.636), respectively. The median bias between PPV and SVV was different for patients younger [-1.5 % (-3 to 0)] or older [+2 % (0-4.75)] than 55 years (P < 0.001), while there were no gender differences in the bias between PPV and SVV. The Nexfin monitor adequately reflects alterations in PPV and SVV during a provoked fluid shift, but the level of agreement between PPV and SVV was low. The SVV tended to be superior over PPV or Eadyn in predicting fluid responsiveness in our population.

  10. How effective are geometric morphometric techniques for assessing functional shape variation? An example from the great ape temporomandibular joint.

    Science.gov (United States)

    Terhune, Claire E

    2013-08-01

    Functional shape analyses have long relied on the use of shape ratios to test biomechanical hypotheses. This method is powerful because of the ease with which results are interpreted, but these techniques fall short in quantifying complex morphologies that may not have a strong biomechanical foundation but may still be functionally informative. In contrast, geometric morphometric methods are continually being adopted for quantifying complex shapes, but they tend to prove inadequate in functional analyses because they have little foundation in an explicit biomechanical framework. The goal of this study was to evaluate the intersection of these two methods using the great ape temporomandibular joint as a case study. Three-dimensional coordinates of glenoid fossa and mandibular condyle shape were collected using a Microscribe digitizer. Linear distances extracted from these landmarks were analyzed using a series of one-way ANOVAs; further, the landmark configurations were analyzed using geometric morphometric techniques. Results suggest that the two methods are broadly similar, although the geometric morphometric data allow for the identification of shape differences among taxa that were not immediately apparent in the univariate analyses. Furthermore, this study suggests several new approaches for translating these shape data into a biomechanical context by adjusting the data using a biomechanically relevant variable. Copyright © 2013 Wiley Periodicals, Inc.

  11. A study on variation types in celiac axis and superior mesenteric artery using 3D volume rendering of MDCT

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jeong Keun; Jang, Seong Joo [Dept. of Radiological physics Graduate School of Dongshin University, Naju (Korea, Republic of); Jang, Young Ill [Dept. of Radiological Technology of Kwangyang Health College, Kwangyang (Korea, Republic of)

    2013-06-15

    The aim of this study was to evaluate the variation which based on Celiac axis and SMA using by CT volume rendering images. 613 patients underwent abdominal CTA, there were 552 patients (99.05%, TypeⅠ, Ⅱ ) with normal anatomical form and 61 (9.95%, Type Ⅲ-Ⅻ) with variation. TypeⅠ was 339(55.31%), Type Ⅱ was 213 (34.74%), Type Ⅲ was 18 (2.93%), Type Ⅳ was 12 patients (1.95%), Type Ⅴ was 11 patient (1.79%), Type Ⅵ was 9 patients (1.46%), Type Ⅶ was 6 patients (0.97%), Type Ⅷ was 1 patient (0.16%), Type Ⅸ was 1 patient (0.16%), Type Ⅹ was 1 patient (0.16%), Type Ⅺ was 1 patient (0.16%), and Type Ⅻ was 1 patient (0.16%) into totally new types of variation. In conclusion, we could found 9 new types of variation by classifying based on celiac axis and superior mesenteric artery. These results were considered to be an important opportunity for a new vessel map.

  12. Pulsations detected in the line profile variations of red giants : modelling of line moments, line bisector and line shape

    NARCIS (Netherlands)

    Hekker, S.; Aerts, C.; Ridder, J. de; Carrier, F.

    2006-01-01

    Context: So far, red giant oscillations have been studied from radial velocity and/or light curve variations, which reveal frequencies of the oscillation modes. To characterise radial and non-radial oscillations, line profile variations are a valuable diagnostic. Here we present for the first time a

  13. FURTHER STUDIES ON THE VARIATION OF SPRAY DEPOSITS IN VINEYARDS WITH AIRFLOW RATE AND VOLUME RATE

    Directory of Open Access Journals (Sweden)

    Emanuele Cerruto

    2007-03-01

    Full Text Available The present research, continuing that reported in [2], deals with the spray application subject, so to investigate as volume rate and airflow rate, forward speed being equal, affect the foliar deposition in an espalier vineyard. Experimental trials were carried out by means of an air assisted towed sprayer, equipped with “Albuz ATR” nozzles. To take into account the influence of the development of the trees, the field trials were replicated in two phenological stages with an interval of about one month: “Inflorescences fully developed” (stage 1 and “Beginning of berry touch” (stage 2. A full factorial experiment was carried out for each growth stage, with two airflow rates (3.9 and 7.5 m3/s, three volume rates (103, 216, and 276 L/ha in the first growth stage and 154, 330 and 432 L/ha in the second growth stage, and four replicates, arranged according to a randomised complete block design. Working pressure (1.2 MPa and forward speed (1.4 m/s were kept unchanged for all the trials. The foliar deposition was measured by means of a spectrophotometric technique. The leaves were sampled on two depth layers and two or three heights, according to the trees’ development. The results showed that volume rate did not significantly influence the mean foliar deposition in both the two growth stages, while the highest deposits were obtained with the lowest airflow rate. The airflow rate × volume rate interaction, though not statistically significant, showed that low volume rates together with high airflow rates, result in a noticeable reduction in foliar deposition (29% with respect the grand mean, due to an increase of the spry drift, especially at the first growth stage, when the foliar development is little. These second tests, unlike those described in [2], did not show any positive influence of the airflow rate on the foliar deposition in the inner part of the canopy, so further investigations could be necessary to better understand the

  14. Probiotics for Rectal Volume Variation During Radiation Therapy for Prostate Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Ki, Yongkan [Department of Radiation Oncology, Pusan National University School of Medicine, Busan (Korea, Republic of); Kim, Wontaek, E-mail: rokwt@hanmail.net [Department of Radiation Oncology, Pusan National University School of Medicine, Busan (Korea, Republic of); Nam, Jiho; Kim, Donghyun; Lee, Juhye; Park, Dahl; Jeon, Hosang [Department of Radiation Oncology, Pusan National University School of Medicine, Busan (Korea, Republic of); Ha, Honggu; Kim, Taenam [Department of Urology, Medical Research Institute, Pusan National University Hospital, Pusan National University School of Medicine, Busan (Korea, Republic of); Kim, Dongwon [Department of Radiation Oncology, Pusan National University School of Medicine, Busan (Korea, Republic of)

    2013-11-15

    Purpose: To investigate the effect of the probiotic Lactobacillus acidophilus on the percentage volume change of the rectum (PVC{sub R}), a crucial factor of prostate movement. Methods and Materials: Prostate cancer patients managed with tomotherapy as a radical treatment were enrolled in the study to take a probiotic capsule containing 1.0 × 10{sup 8} colony-forming units of L acidophilus or a placebo capsule twice daily. Radiation therapy was performed at a dose of 78 Gy in 39 fractions. The PVC{sub R}, defined as the difference in rectal volume between the planning computed tomographic (CT) and daily megavoltage CT images, was analyzed. Results: Forty patients were randomized into 2 groups. The L acidophilus group showed significantly lower median rectal volume and median PVC{sub R} values than the placebo group. L acidophilus showed a significant reduction effect on the PVC{sub R} (P<.001). However, the radiation therapy fraction number did not significantly influence the PVC{sub R}. Conclusions: L acidophilus was useful in reducing the PVC{sub R}, which is the most important determining factor of prostate position, during radiation therapy for prostate cancer.

  15. Seasonal variation in serum testosterone, testicular volume and semen characteristics in coatis (Nasua nasua).

    Science.gov (United States)

    da Paz, Regina Celia Rodrigues; Dos Santos Avila, Heide Belle; Morgado, Thais Oliveira; Nichi, Marcilio

    2012-04-15

    The objective was to characterize seasonal changes in serum testosterone concentration, testicular volume and sperm quantity and quality in captive coatis (Nasua nasua) from Pantanal, MT, Brazil. Sampling was done once monthly for 1 y. Mean (± SEM) serum testosterone concentrations (767.37 ± 216.2 ng/ml) and total and progressive sperm motility (79.6 ± 3.9%; 3.8 ± 0.3, on a scale of 0 to 5) peaked in July. The highest combined testis volume (10.3 ± 0.4 cm(3)) and sperm concentration (403 million ± 102 sperm/ml) occurred in August, at the peak of the winter breeding season. No seasonal effects on percentages of morphologically normal sperm, acrosome integrity, or live sperm were detected; however, the percentage of secondary sperm defects was higher in the winter. In conclusion, intricate relationships between testosterone concentration, testis volume, semen concentration and total and progressive sperm motility with high levels of breeding activity were observed during the dry season in the winter (June, July, August), followed by a subsequent decline in these activities during the wet season (i.e., summer: December, January, February). There was no seasonal pattern for production of functionally intact and morphologically normal sperm. Copyright © 2012 Elsevier Inc. All rights reserved.

  16. Genetic variation in white matter hyperintensity volume in the Framingham Study.

    Science.gov (United States)

    Atwood, Larry D; Wolf, Philip A; Heard-Costa, Nancy L; Massaro, Joseph M; Beiser, Alexa; D'Agostino, Ralph B; DeCarli, Charles

    2004-07-01

    In a previous study of normal elderly male twins, the heritability of quantitative white matter hyperintensity (WMH) volume has been estimated to be high (0.73). We investigated heritability of WMH in a family-based sample of the Framingham Heart Study for sex differences and the impact of age. Brain magnetic resonance scans were performed on 2012 individuals in the cohort and offspring of the Framingham study. This report was limited to 1330 stroke-free and dementia-free members (mean age 61.0 years) of the Framingham offspring. Individuals with a history of multiple sclerosis, stroke, dementia, or other neurological condition including traumatic brain injury were excluded from this analysis. WMH volume and total cranial volume (TCV) were quantified using a previously published algorithm. Because of extreme skewing, measures of WMH were log-transformed before analysis. Variance components methods were used to estimate heritability of WMH after adjusting for sex, age, age2, and TCV. In the full dataset, WMH heritability was 0.55 (Pmen was 0.52 (Polder. Using a family-based study design comprising generally healthy individuals, this study found high heritability of WMH overall and similar heritability for both men and women. In addition, the heritability of WMH remained high among individuals in whom the prevalence of cerebrovascular brain injury was generally low, suggesting that WMH is also likely to be an excellent genetic marker of brain aging.

  17. Evaluating Variations of Bladder Volume Using an Ultrasound Scanner in Rectal Cancer Patients during Chemoradiation: Is Protocol-Based Full Bladder Maintenance Using a Bladder Scanner Useful to Maintain the Bladder Volume?

    Directory of Open Access Journals (Sweden)

    Hong In Yoon

    Full Text Available The maintenance of full bladder is important to reduce radiation-induced toxicities and maintain the therapeutic consistency in locally advanced rectal cancer patients who underwent radiotherapy (RT. So, the aim of this study was to evaluate the effectiveness of protocol-based full bladder maintenance by assessing bladder volume variation using an ultrasound bladder scanner to maintain bladder volume.From March 2011 to May 2011, twenty consecutive rectal cancer patients receiving external beam RT participated in this prospective study. Protocol-based full bladder maintenance consisted of education, training and continuous biofeedback by measuring bladder volume. Bladder volume was measured by bladder scan immediately before simulation CT scan and before each treatment three times weekly during the RT period. The relative bladder volume change was calculated. Intra-patient bladder volume variations were quantified using interquartile range (IQR of relative bladder volume change in each patient. We compared intra-patient bladder volume variations obtained (n=20 with data from our previous study patients (n=20 performing self-controlled maintenance without protocol.Bladder volumes measured by bladder scan highly correlated with those on simulation CT scan (R=0.87, p<0.001. Patients from this study showed lower median IQR of relative bladder volume change compared to patients of self-controlled maintenance from our previous study, although it was not statistically significant (median 32.56% vs. 42.19%, p=0.058. Upon logistic regression, the IQR of relative bladder volume change was significantly related to protocol-based maintenance [relative risk 1.045, 95% confidence intervals (CI 1.004-1.087, p=0.033]. Protocol-based maintenance included significantly more patients with an IQR of relative bladder volume change less than 37% than self-controlled maintenance (p=0.025.Our findings show that bladder volume could be maintained more consistently during

  18. Arterial pressure variations as parameters of brain perfusion in response to central blood volume depletion and repletion

    Science.gov (United States)

    Bronzwaer, Anne-Sophie G. T.; Stok, Wim J.; Westerhof, Berend E.; van Lieshout, Johannes J.

    2014-01-01

    Rationale: A critical reduction in central blood volume (CBV) is often characterized by hemodynamic instability. Restoration of a volume deficit may be established by goal-directed fluid therapy guided by respiration-related variation in systolic- and pulse pressure (SPV and PPV). Stroke volume index (SVI) serves as a surrogate end-point of a fluid challenge but tissue perfusion itself has not been addressed. Objective: To delineate the relationship between arterial pressure variations, SVI and regional brain perfusion during CBV depletion and repletion in spontaneously breathing volunteers. Methods: This study quantified in 14 healthy subjects (11 male) the effects of CBV depletion [by 30 and 70 degrees passive head-up tilt (HUT)] and a fluid challenge (by tilt back) on CBV (thoracic admittance), mean middle cerebral artery (MCA) blood flow velocity (Vmean), SVI, cardiac index (CI), PPV, and SPV. Results: PPV (103 ± 89%, p pressure. The reduction in MCAVmean correlated to the fall in SVI (R2 = 0.52, p < 0.0001) and inversely to PPV and SPV [R2 = 0.46 (p < 0.0001) and R2 = 0.45 (p < 0.0001), respectively]. PPV and SPV predicted a ≥15% reduction in MCAVmean and SVI with comparable sensitivity (67/67% vs. 63/68%, respectively) and specificity (89/94 vs. 89/94%, respectively). A rapid fluid challenge by tilt-back restored all parameters to baseline values within 1 min. Conclusion: In spontaneously breathing subjects, a reduction in MCAVmean was related to an increase in PPV and SPV during graded CBV depletion and repletion. Specifically, PPV and SPV predicted changes in both SVI and MCAVmean with comparable sensitivity and specificity, however the predictive value is limited in spontaneously breathing subjects. PMID:24795652

  19. THE EFFECT OF VOLUME VARIATION OF SILVER NANOPARTICLE SOLUTION TOWARDS THE POROSITY AND COMPRESSIVE STRENGTH OF MORTAR

    Directory of Open Access Journals (Sweden)

    W.S.B. Dwandaru

    2016-10-01

    Full Text Available As the world is growing rapidly, people need better building materials such as mortar. The aim of this research is to determine the effect of adding silver nanoparticle solution towards the porosity and compressive strength of mortar. This research was started by making silver nanoparticle solution from nitrate silver (AgNO3. The solution is then characterized using Uv-Vis spectrophotometer. 5 mM silver nanoparticle is added in the process of mortar production with volume variation of the silver nanoparticle solution. The porosity, compressive strength, and the content of mortar were determined by digital scale, universal testing machine, and X-ray diffraction, respectively. For silver nanoparticle solution volumes of (in mL 0, 5, 10, 15, 20, and 25 the porosity obtained are (in % 20.38, 19.48, 19.42, 18.9, 17.8, and 17.5, respectively. The best increase in compressive strength is obtained for (in MPa 29,068, 29,308, and 31,385, with nanoparticle solution volumes of (in mL 5, 10, and 15   Keywords: mortar, silver nanoparticle, compressive strength

  20. Meta-analysis of genome-wide association studies identifies 8 novel loci involved in shape variation of human head hair.

    Science.gov (United States)

    Liu, Fan; Chen, Yan; Zhu, Gu; Hysi, Pirro G; Wu, Sijie; Adhikari, Kaustubh; Breslin, Krystal; Pospiech, Ewelina; Hamer, Merel A; Peng, Fuduan; Muralidharan, Charanya; Acuna-Alonzo, Victor; Canizales-Quinteros, Samuel; Bedoya, Gabriel; Gallo, Carla; Poletti, Giovanni; Rothhammer, Francisco; Bortolini, Maria Catira; Gonzalez-Jose, Rolando; Zeng, Changqing; Xu, Shuhua; Jin, Li; Uitterlinden, André G; Ikram, M Arfan; van Duijn, Cornelia M; Nijsten, Tamar; Walsh, Susan; Branicki, Wojciech; Wang, Sijia; Ruiz-Linares, Andrés; Spector, Timothy D; Martin, Nicholas G; Medland, Sarah E; Kayser, Manfred

    2017-12-06

    Shape variation of human head hair shows striking variation within and between human populations, while its genetic basis is far from being understood. We performed a series of genome-wide association studies (GWASs) and replication studies in a total of 28,964 subjects from 9 cohorts from multiple geographic origins. A meta-analysis of three European GWASs identified 8 novel loci (1p36.23 ERRFI1/SLC45A1, 1p36.22 PEX14, 1p36.13 PADI3, 2p13.3 TGFA, 11p14.1 LGR4, 12q13.13 HOXC13, 17q21.2 KRTAP, and 20q13.33 PTK6), and confirmed 4 previously known ones (1q21.3 TCHH/TCHHL1/LCE3E, 2q35 WNT10A, 4q21.21 FRAS1, and 10p14 LINC00708/GATA3), all showing genome-wide significant association with hair shape (P < 5e-8). All except one (1p36.22 PEX14) were replicated with nominal significance in at least one of the 6 additional cohorts of European, Native American and East Asian origins. Three additional previously known genes (EDAR, OFCC1, and PRSS53) were confirmed at nominal significance level. A multivariable regression model revealed that 14 SNPs from different genes significantly and independently contribute to hair shape variation, reaching a cross-validated AUC value of 0.66 (95% CI: 0.62-0.70) and an AUC value of 0.64 in an independent validation cohort, providing an improved accuracy compared to a previous model. Prediction outcomes of 2,504 individuals from a multiethnic sample were largely consistent with general knowledge on the global distribution of hair shape variation. Our study thus delivers target genes and DNA variants for future functional studies to further evaluate the molecular basis of hair shape in humans. © The Author 2017. Published by Oxford University Press.

  1. Molecular Dynamics Simulation of the Effect of Angle Variation on Water Permeability through Hourglass-Shaped Nanopores.

    Science.gov (United States)

    Tang, Dai; Li, Longnan; Shahbabaei, Majid; Yoo, Yeong-Eun; Kim, Daejoong

    2015-10-29

    Water transport through aquaporin water channels occurs extensively in cell membranes. Hourglass-shaped (biconical) pores resemble the geometry of these aquaporin channels and therefore attract much research attention. We assumed that hourglass-shaped nanopores are capable of high water permeation like biological aquaporins. In order to prove the assumption, we investigated nanoscale water transport through a model hourglass-shaped pore using molecular dynamics simulations while varying the angle of the conical entrance and the total nanopore length. The results show that a minimal departure from optimized cone angle (e.g., 9° for 30 Å case) significantly increases the osmotic permeability and that there is a non-linear relationship between permeability and the cone angle. The analysis of hydrodynamic resistance proves that the conical entrance helps to reduce the hydrodynamic entrance hindrance. Our numerical and analytical results thus confirm our initial assumption and suggest that fast water transport can be achieved by adjusting the cone angle and length of an hourglass-shaped nanopore.

  2. Molecular Dynamics Simulation of the Effect of Angle Variation on Water Permeability through Hourglass-Shaped Nanopores

    Directory of Open Access Journals (Sweden)

    Dai Tang

    2015-10-01

    Full Text Available Water transport through aquaporin water channels occurs extensively in cell membranes. Hourglass-shaped (biconical pores resemble the geometry of these aquaporin channels and therefore attract much research attention. We assumed that hourglass-shaped nanopores are capable of high water permeation like biological aquaporins. In order to prove the assumption, we investigated nanoscale water transport through a model hourglass-shaped pore using molecular dynamics simulations while varying the angle of the conical entrance and the total nanopore length. The results show that a minimal departure from optimized cone angle (e.g., 9° for 30 Å case significantly increases the osmotic permeability and that there is a non-linear relationship between permeability and the cone angle. The analysis of hydrodynamic resistance proves that the conical entrance helps to reduce the hydrodynamic entrance hindrance. Our numerical and analytical results thus confirm our initial assumption and suggest that fast water transport can be achieved by adjusting the cone angle and length of an hourglass-shaped nanopore.

  3. Influence of deformation temperature on structural variation and shape-memory effect of a thermoplastic semi-crystalline multiblock copolymer

    Directory of Open Access Journals (Sweden)

    W. Yan

    2015-07-01

    Full Text Available A multiblock copolymer termed as PCL-PIBMD, consisting of crystallizable poly(ε-caprolactone (PCL segments and crystallizable poly(3S-isobutyl-morpholine-2,5-dione (PIBMD segments, has been reported as a material showing a thermally-induced shape-memory effect. While PIBMD crystalline domains act as netpoints to determine the permanent shape, both PCL crystalline domains and PIBMD amorphous domains, which have similar transition temperatures (Ttrans can act as switching domains. In this work, the influence of the deformation temperature (Tdeform = 50 or 20°C, which was above or below Ttrans, on the structural changes of PCL-PIBMD during uniaxial deformation and the shapememory properties were investigated. Furthermore, the relative contribution of crystalline PCL and PIBMD amorphous phases to the fixation of the temporary shape were distinguished by a toluene vapor treatment approach. The results indicated that at 50°C, both PCL and PIBMD amorphous phases can be orientated during deformation, resulting in thermallyinduced crystals of PCL domains and joint contribution to the switching domains. In contrast at 20°C, the temporary shape was mainly fixed by PCL crystals generated via strain-induced crystallization.

  4. Cholesterol-induced variations in the volume and enthalpy fluctuations of lipid bilayers.

    Science.gov (United States)

    Halstenberg, S; Heimburg, T; Hianik, T; Kaatze, U; Krivanek, R

    1998-07-01

    The sound velocity and density of suspensions of large unilamellar liposomes from dimyristoylphosphatidylcholine with admixed cholesterol have been measured as a function of temperature around the chain melting temperature of the phospholipid. The cholesterol-to-phospholipid molar ratio xc has been varied over a wide range (0 volume of the phospholipid, and of the apparent specific adiabatic compressibility have been derived from the measured data. These data are particularly discussed with respect to the volume fluctuations within the samples. A theoretical relation between the compressibility and the excess heat capacity of the bilayer system has been derived. Comparison of the compressibilities (and sound velocity numbers) with heat capacity traces display the close correlation between these quantities for bilayer systems. This correlation appears to be very useful as it allows some of the mechanical properties of membrane systems to be calculated from the specific heat capacity data and vice versa.

  5. Factors and processes shaping the population structure and distribution of genetic variation across the species range of the freshwater snail radix balthica (Pulmonata, Basommatophora

    Directory of Open Access Journals (Sweden)

    Feldmeyer Barbara

    2011-05-01

    Full Text Available Abstract Background Factors and processes shaping the population structure and spatial distribution of genetic diversity across a species' distribution range are important in determining the range limits. We comprehensively analysed the influence of recurrent and historic factors and processes on the population genetic structure, mating system and the distribution of genetic variability of the pulmonate freshwater snail Radix balthica. This analysis was based on microsatellite variation and mitochondrial haplotypes using Generalised Linear Statistical Modelling in a Model Selection framework. Results Populations of R. balthica were found throughout North-Western Europe with range margins marked either by dispersal barriers or the presence of other Radix taxa. Overall, the population structure was characterised by distance independent passive dispersal mainly along a Southwest-Northeast axis, the absence of isolation-by-distance together with rather isolated and genetically depauperated populations compared to the variation present in the entire species due to strong local drift. A recent, climate driven range expansion explained most of the variance in genetic variation, reducing at least temporarily the genetic variability in this area. Other factors such as geographic marginality and dispersal barriers play only a minor role. Conclusions To our knowledge, such a population structure has rarely been reported before. It might nevertheless be typical for passively dispersed, patchily distributed taxa (e.g. freshwater invertebrates. The strong local drift implied in such a structure is expected to erode genetic variation at both neutral and coding loci and thus probably diminish evolutionary potential. This study shows that the analysis of multiple factors is crucial for the inference of the processes shaping the distribution of genetic variation throughout species ranges.

  6. Implementation of a target volume design function for intrafractional range variation in a particle beam treatment planning system.

    Science.gov (United States)

    Mori, S; Inaniwa, T; Miki, K; Shirai, T; Noda, K

    2014-11-01

    Treatment planning for charged particle therapy in the thoracic and abdominal regions should take account of range uncertainty due to intrafractional motion. Here, we developed a design tool (4Dtool) for the target volume [field-specific target volume (FTV)], which accounts for this uncertainty using four-dimensional CT (4DCT). Target and normal tissue contours were input manually into a treatment planning system (TPS). These data were transferred to the 4Dtool via the picture archiving and communication system (PACS). Contours at the reference phase were propagated to other phases by deformable image registration. FTV was calculated using 4DCT on the 4Dtool. The TPS displays FTV contours using digital imaging and communications in medicine files imported from the PACS. These treatment parameters on the CT image at the reference phase were then used for dose calculation on the TPS. The tool was tested in single clinical case randomly selected from patients treated at our centre for lung cancer. In this clinical case, calculation of dose distribution with the 4Dtool resulted in the successful delivery of carbon-ion beam at the reference phase of 95% of the prescribed dose to the clinical target volume (CTV). Application to the other phases also provided sufficient dose to the CTV. The 4Dtool software allows the design of the target volume with consideration to intrafractional range variation and is now in routine clinical use at our institution. Our alternative technique represents a practical approach to four-dimensional treatment planning within the current state of charged particle therapy.

  7. Cranial and mandibular shape variation in the genus Carollia (Mammalia: Chiroptera) from Colombia: biogeographic patterns and morphological modularity.

    Science.gov (United States)

    López-Aguirre, Camilo; Pérez-Torres, Jairo; Wilson, Laura A B

    2015-01-01

    Neotropical bats of the genus Carollia are widely studied due to their abundance, distribution and relevance for ecosystems. However, the ecomorphological boundaries of these species are poorly differentiated, and consequently correspondence between their geographic distribution, ecological plasticity and morphological variation remains unclear. In this study, patterns of cranial and mandibular morphological variation were assessed for Carollia brevicauda, C. castanea and C. perspicillata from Colombia. Using geometric morphometrics, morphological variation was examined with respect to: differences in intraspecific variation, morphological modularity and integration, and biogeographic patterns. Patterns of intraspecific variation were different for each species in both cranial and mandibular morphology, with functional differences apparent according to diet. Cranial modularity varied between species whereas mandibular modularity did not. High cranial and mandibular correlation reflects Cranium-Mandible integration as a functional unit. Similarity between the biogeographic patterns in C. brevicauda and C. perspicillata indicates that the Andes do not act as a barrier but rather as an independent region, isolating the morphology of Andean populations of larger-bodied species. The biogeographic pattern for C. castanea was not associated with the physiography of the Andes, suggesting that large body size does not benefit C. brevicauda and C. perspicillata in maintaining homogeneous morphologies among populations.

  8. Fine-scale variation in microclimate across an urban landscape shapes variation in mosquito population dynamics and the potential of Aedes albopictus to transmit arboviral disease.

    Science.gov (United States)

    Murdock, Courtney C; Evans, Michelle V; McClanahan, Taylor D; Miazgowicz, Kerri L; Tesla, Blanka

    2017-05-01

    Most statistical and mechanistic models used to predict mosquito-borne disease transmission incorporate climate drivers of disease transmission by utilizing environmental data collected at geographic scales that are potentially coarser than what mosquito populations may actually experience. Temperature and relative humidity can vary greatly between indoor and outdoor environments, and can be influenced strongly by variation in landscape features. In the Aedes albopictus system, we conducted a proof-of-concept study in the vicinity of the University of Georgia to explore the effects of fine-scale microclimate variation on mosquito life history and vectorial capacity (VC). We placed Ae. albopictus larvae in artificial pots distributed across three replicate sites within three different land uses-urban, suburban, and rural, which were characterized by high, intermediate, and low proportions of impervious surfaces. Data loggers were placed into each larval environment and in nearby vegetation to record daily variation in water and ambient temperature and relative humidity. The number of adults emerging from each pot and their body size and sex were recorded daily. We found mosquito microclimate to significantly vary across the season as well as with land use. Urban sites were in general warmer and less humid than suburban and rural sites, translating into decreased larval survival, smaller body sizes, and lower per capita growth rates of mosquitoes on urban sites. Dengue transmission potential was predicted to be higher in the summer than the fall. Additionally, the effects of land use on dengue transmission potential varied by season. Warm summers resulted in a higher predicted VC on the cooler, rural sites, while warmer, urban sites had a higher predicted VC during the cooler fall season.

  9. Fine-scale variation in microclimate across an urban landscape shapes variation in mosquito population dynamics and the potential of Aedes albopictus to transmit arboviral disease.

    Directory of Open Access Journals (Sweden)

    Courtney C Murdock

    2017-05-01

    Full Text Available Most statistical and mechanistic models used to predict mosquito-borne disease transmission incorporate climate drivers of disease transmission by utilizing environmental data collected at geographic scales that are potentially coarser than what mosquito populations may actually experience. Temperature and relative humidity can vary greatly between indoor and outdoor environments, and can be influenced strongly by variation in landscape features. In the Aedes albopictus system, we conducted a proof-of-concept study in the vicinity of the University of Georgia to explore the effects of fine-scale microclimate variation on mosquito life history and vectorial capacity (VC. We placed Ae. albopictus larvae in artificial pots distributed across three replicate sites within three different land uses-urban, suburban, and rural, which were characterized by high, intermediate, and low proportions of impervious surfaces. Data loggers were placed into each larval environment and in nearby vegetation to record daily variation in water and ambient temperature and relative humidity. The number of adults emerging from each pot and their body size and sex were recorded daily. We found mosquito microclimate to significantly vary across the season as well as with land use. Urban sites were in general warmer and less humid than suburban and rural sites, translating into decreased larval survival, smaller body sizes, and lower per capita growth rates of mosquitoes on urban sites. Dengue transmission potential was predicted to be higher in the summer than the fall. Additionally, the effects of land use on dengue transmission potential varied by season. Warm summers resulted in a higher predicted VC on the cooler, rural sites, while warmer, urban sites had a higher predicted VC during the cooler fall season.

  10. Morphometric analysis for evaluating the relation between incisal guidance angle, occlusal plane angle, and functional temporomandibular joint shape variation.

    Science.gov (United States)

    Han, Seulgi; Shin, Sang Min; Choi, Yong-Seok; Kim, So Yeun; Ko, Ching-Chang; Kim, Yong-Il

    2018-01-11

    The correlations between morphology of the temporomandibular joint structure, the anterior guidance angle, and occlusal plane were investigated. A cone beam computed tomography analysis was performed in 158 patients (86 women and 72 men). 3D software was employed to obtain the coordinates of the shape of the incisal guidance angle, occlusal guidance angle, articular fossa, and mandibular condyle. Generalized Procrustes analysis including principal components analysis (PCA) were performed and produced principal components (PCs) scores of each shape and their centroid size (CS). A significant Pearson correlation coefficient of 0.3451 (p angle and occlusal plane. The CS also showed a correlation with the incisal guidance angle, but not with the occlusal plane angle. The PCA results revealed that there were no significant correlations between the temporomandibular joint structure (TMJ) shape (fossa and condyle) and the incisal guidance angle. Incisor guidance angle and occlusal plane angle were correlated. In addition, there was a correlation between CS and incisal guidance angle. In the PCA, It can be concluded that the size is more related to the incisor guidance angle than the morphological factors of the constituent components of the TMJ.

  11. Shape-Based Online Multitarget Tracking and Detection for Targets Causing Multiple Measurements: Variational Bayesian Clustering and Lossless Data Association.

    Science.gov (United States)

    De Laet, Tinne; Bruyninckx, Herman; De Schutter, Joris

    2011-12-01

    This paper proposes a novel online two-level multitarget tracking and detection (MTTD) algorithm. The algorithm focuses on multitarget detection and tracking for the case of multiple measurements per target and for an unknown and varying number of targets. Information is continuously exchanged in both directions between the two levels. Using the high level target position and shape information, the low level clusters the measurements. Furthermore, the low level features automatic relevance detection (ARD), as it automatically determines the optimal number of clusters from the measurements taking into account the expected target shapes. The high level's data association allows for a varying number of targets. A joint probabilistic data association algorithm looks for associations between clusters of measurements and targets. These associations are used to update the target trackers and the target shapes with the individual measurements. No information is lost in the two-level approach since the measurement information is not summarized into features. The target trackers are based on an underlying motion model, while the high level is supplemented with a filter estimating the number of targets. The algorithm is verified using both simulations and experiments using two sensor modalities, video and laser scanner, for detection and tracking of people and ants.

  12. Impact of Variations in Prostatic Apex Shape on Apical Margin Positive Rate After Radical Prostatectomy: Robot-Assisted Laparoscopic Radical Prostatectomy vs Open Radical Prostatectomy.

    Science.gov (United States)

    Yu, Young Dong; Lee, Minseung; Hong, Sung Kyu; Byun, Seok-Soo; Lee, Sang Eun; Lee, Sangchul

    2018-01-05

    To evaluate the effects of prostatic apex shape variations on positive apical margin (PAM) rate after radical prostatectomy (RP) by undertaking a comparative study of robot-assisted laparoscopic radical prostatectomy (RALP) vs open radical prostatectomy (ORP). A total of 3324 cases of RP (1004 ORP and 2320 RALP) from January 2004 to March 2017 were retrospectively reviewed. All patients underwent preoperative MRI and the cohorts were stratified into four categories according to prostatic apical shape at the midsagittal plane. Between ORP and RALP groups, age, body mass index, preoperative prostate-specific antigen (PSA), biopsy and pathological Gleason score (GS), clinical and pathological stage, and prostatic apex shapes were compared. Logistic regression analyses were performed to evaluate significant predictors of PAM. Propensity adjustments were undertaken before statistical analysis to minimize the lack of randomization. ORP and RALP groups showed no significant differences in age, body mass index, PSA, biopsy and pathological GS, clinical and pathological stage, as well as prostatic apical shape variations. The ORP group showed a PAM of 17.5% that was significantly higher than 12.3% of the RALP group (p < 0.001). Both groups showed the highest PAM with apical type 3, which is the apex covering the posterior aspect of membranous urethra (ORP 33.9%, RALP 28.5%). In unadjusted data, multiple logistic regression analysis showed that prostate apical type 3 was a significant independent predictor of PAM, but other apex types were not. Prostate apical type 3 was a significant independent predictor of PAM. The RALP group showed better outcomes in terms of PAM compared with the ORP group. Preoperative MRI might be a potentially useful tool for preoperative designing of the surgical modalities.

  13. Cell responses only partially shape cell-to-cell variations in protein abundances in Escherichia coli chemotaxis.

    Science.gov (United States)

    Mukherjee, Sayak; Seok, Sang-Cheol; Vieland, Veronica J; Das, Jayajit

    2013-11-12

    Cell-to-cell variations in protein abundance in clonal cell populations are ubiquitous in living systems. Because protein composition determines responses in individual cells, it stands to reason that the variations themselves are subject to selective pressures. However, the functional role of these cell-to-cell differences is not well understood. One way to tackle questions regarding relationships between form and function is to perturb the form (e.g., change the protein abundances) and observe the resulting changes in some function. Here, we take on the form-function relationship from the inverse perspective, asking instead what specific constraints on cell-to-cell variations in protein abundance are imposed by a given functional phenotype. We develop a maximum entropy-based approach to posing questions of this type and illustrate the method by application to the well-characterized chemotactic response in Escherichia coli. We find that full determination of observed cell-to-cell variations in protein abundances is not inherent in chemotaxis itself but, in fact, appears to be jointly imposed by the chemotaxis program in conjunction with other factors (e.g., the protein synthesis machinery and/or additional nonchemotactic cell functions, such as cell metabolism). These results illustrate the power of maximum entropy as a tool for the investigation of relationships between biological form and function.

  14. Nonlinear selection and a blend of convergent, divergent and parallel evolution shapes natural variation in glucosinolates

    DEFF Research Database (Denmark)

    Kliebenstein, Daniel James; Cacho, N. Ivalú

    2016-01-01

    The molecular mechanisms underlying organismal fitness in complex environments is just beginning to be illuminated. One of the pre-eminent model systems that span the molecular to field fitness chasm is the natural variation in glucosinolate defence metabolites within the Capparales. In this syst...

  15. Clear-cornea cataract surgery: pupil size and shape changes, along with anterior chamber volume and depth changes. A Scheimpflug imaging study.

    Science.gov (United States)

    Kanellopoulos, Anastasios John; Asimellis, George

    2014-01-01

    To investigate, by high-precision digital analysis of data provided by Scheimpflug imaging, changes in pupil size and shape and anterior chamber (AC) parameters following cataract surgery. The study group (86 eyes, patient age 70.58±10.33 years) was subjected to cataract removal surgery with in-the-bag intraocular lens implantation (pseudophakic). A control group of 75 healthy eyes (patient age 51.14±16.27 years) was employed for comparison. Scheimpflug imaging (preoperatively and 3 months postoperatively) was employed to investigate central corneal thickness, AC depth, and AC volume. In addition, by digitally analyzing the black-and-white dotted line pupil edge marking in the Scheimpflug "large maps," the horizontal and vertical pupil diameters were individually measured and the pupil eccentricity was calculated. The correlations between AC depth and pupil shape parameters versus patient age, as well as the postoperative AC and pupil size and shape changes, were investigated. Compared to preoperative measurements, AC depth and AC volume of the pseudophakic eyes increased by 0.99±0.46 mm (39%; PPupil size analysis showed that the horizontal pupil diameter was reduced by -0.27±0.22 mm (-9.7%; P=0.001) and the vertical pupil diameter was reduced by -0.32±0.24 mm (-11%; PPupil eccentricity was reduced by -39.56%; Paffect pupil size and shape, possibly in correlation to AC depth increase. This novel investigation based on digital analysis of Scheimpflug imaging data suggests that the cataract postoperative photopic pupil is reduced and more circular. These changes appear to be more significant with increasing patient age.

  16. Shapes, Proportions, and Variations in Breast Aesthetic Ideals: The Definition of Breast Beauty, Analysis, and Surgical Practice.

    Science.gov (United States)

    Mallucci, Patrick; Branford, Olivier Alexandre

    2015-10-01

    There are few objective analyses in the plastic surgical literature to define an aesthetically pleasing template for breast shape and proportion. The authors previously identified key objective parameters that define breast aesthetic ideals in 2 studies: an observational analysis of 100 models with natural breasts, and a population analysis with 1315 respondents. From these data a simple yet reproducible formula for surgical planning in breast augmentation has been developed to consistently achieve beautiful breasts, namely the ICE principle. This article proposes that this principle be used as the basis for design in aesthetic breast surgery. Copyright © 2015 Elsevier Inc. All rights reserved.

  17. Evolutionary history shapes the association between developmental instability and population-level genetic variation in three-spined sticklebacks

    OpenAIRE

    van Dongen, S.; Lens, L.; Pape, E.; Volckaert, Filip; Raeymaekers, Joost

    2009-01-01

    Developmental instability (DI) is the sensitivity of a developing trait to random noise and can be measured by degrees of directionally random asymmetry [fluctuating asymmetry (FA)]. FA has been shown to increase with loss of genetic variation and inbreeding as measures of genetic stress, but associations vary among studies. Directional selection and evolutionary change of traits have been hypothesized to increase the average levels of FA of these traits and to increase the association streng...

  18. Shape and size variations of Aegla uruguayana (Anomura, Aeglidae under laboratory conditions: A geometric morphometric approach to the growth

    Directory of Open Access Journals (Sweden)

    Valeria P. Diawol

    2015-03-01

    Full Text Available Crustacean growth studies typically use modal analysis rather than focusing on the growth of individuals. In the present work, we use geometric morphometrics to determine how organism shape and size varies during the life of the freshwater crab, Aegla uruguayana Schmitt, 1942. A total of 66 individuals from diverse life cycle stages were examined daily and each exuvia was recorded. Digital images of the dorsal region of the cephalothorax were obtained for each exuvia and were subsequently used to record landmark configurations. Moult increment and intermoult period were estimated for each crab. Differences in shape between crabs of different sizes (allometry and sexes (sexual dimorphism; SD were observed. Allometry was registered among specimens; however, SD was not statistically significant between crabs of a given size. The intermoult period increased as size increased, but the moult frequency was similar between the sexes. Regarding ontogeny, juveniles had short and blunt rostrum, robust forehead region, and narrow cephalothorax. Unlike juveniles crabs, adults presented a well-defined anterior and posterior cephalothorax region. The rostrum was long and stylised and the forehead narrow. Geometric morphometric methods were highly effective for the analysis of aeglid-individual- growth and avoided excessive handling of individuals through exuvia analysis.

  19. Effect of finishing instrumentation using NiTi hand files on volume, surface area and uninstrumented surfaces in C-shaped root canal systems.

    Science.gov (United States)

    Amoroso-Silva, P; Alcalde, M P; Hungaro Duarte, M A; De-Deus, G; Ordinola-Zapata, R; Freire, L G; Cavenago, B C; De Moraes, I G

    2017-06-01

    To assess the effect of 90°-oscillatory instrumentation with hand files on several morphological parameters (volume, surface area and uninstrumented surface) in C-shaped root canals after instrumentation using a single-file reciprocation system (Reciproc; VDW, Munich, Germany) and a Self-Adjusting File System (SAF; ReDent Nova, Ra'anana, Israel). Twenty mandibular second molars with C-shaped canals and C1 canal configurations were divided into two groups (n = 10) and instrumented with Reciproc and SAF instruments. A size 30 NiTi hand K-file attached to a 90°-oscillatory motion handpiece was used as final instrumentation in both groups. The specimens were scanned using micro-computed tomography after all procedures. Volume, surface area increase and uninstrumented root canal surface were analysed using CTAn software (Bruker-microCT, Kontich, Belgium). Also, the uninstrumented root canal surface was calculated for each canal third. All values were compared between groups using the Mann-Whitney test and within groups using the Wilcoxon's signed-rank test. Instrumentation with Reciproc significantly increased canal volume compared with instrumentation with SAF. Additionally, the canal volumes were significantly increased after 90°-oscillatory instrumentation (between and within group comparison; (P instrumentation protocols, statistical analysis only revealed significant differences in the within groups comparison (P instrumentation yielded an uninstrumented root canal surface of 28% and 34%, respectively, which was not significantly different (P > 0.05). Final oscillatory instrumentation significantly reduced the uninstrumented root canal surface from 28% to 9% (Reciproc) and from 34% to 15% (SAF; P instrumentation that was significantly reduced after oscillatory instrumentation (P instrumentation of mandibular second molars with C-shaped canals except for a higher canal volume increase in the Reciproc group compared to the SAF. Furthermore, the final use

  20. Industrial based volume manufacturing of lightweight aluminium alloy panel components with high-strength and complex-shape for car body and chassis structures

    Science.gov (United States)

    Anyasodor, Gerald; Koroschetz, Christian

    2017-09-01

    To achieve the high volume manufacture of lightweight passenger cars at economic cost as required in the automotive industry, low density materials and new process route will be needed. While high strength aluminium alloy grades: AA7075 and AA6082 may provide the alternative material solution, hot stamping process used for high-strength and ultrahigh strength steels such as boron steel 22mnb5 can enable the volume manufacture of panel components with high-strength and complex-shape for car body and chassis structures. These aluminium alloy grades can be used to manufacture panel components with possible yield strengths ≥ 500 MPa. Due to the differences in material behaviors, hot stamping process of 22mnb5 cannot be directly applied to high strength aluminium alloy grades. Despite recorded successes in laboratories, researches and niche hot forming processes of high strength aluminium alloy grades, not much have been achieved for adequate and efficient volume manufacturing system applicable in the automotive industry. Due to lack of such system and based on expert knowledge in hot stamping production-line, AP&T presents in this paper a hot stamping processing route for high strength aluminium alloys been suitable for production-line development and volume manufacturing.

  1. Investigation of the Enthalpy/Entropy Variation and Structure of Cu-Al-Mn-Fe Shape Memory Alloys

    Science.gov (United States)

    Canbay, C. Aksu; Gudeloglu, S.; Genc, Z. Karagoz

    2015-04-01

    Cu-based Cu-Al-Mn-Fe shape memory alloys were produced in an arc melter under vacuum. The crystal structure of the fabricated alloys were determined by means of X-ray diffraction (XRD). The XRD analysis results indicated that the martensitic phase of the samples have an M18R structure. The characteristic transformation temperatures, thermodynamic parameters, and the activation energy values of the samples according to Kissinger and Ozawa methods were determined by differential scanning calorimetry measurements. The austenite transformation temperatures of the samples were found as , respectively. Also, the calculated activation energy values of the samples according to Kissinger and Ozawa methods are compared with each other. The effect of the presence of Al and Fe in the samples on the thermodynamic parameters is studied in this work.

  2. Variation in mouthguard thickness according to heating conditions during fabrication Part 2: sheet shape and effect of thermal shrinkage.

    Science.gov (United States)

    Takahashi, Mutsumi; Koide, Kaoru

    2016-06-01

    The aim of this study was to investigate the influence of the thermal shrinkage to thickness of the mouthguard with the heating method by the setting position of a sheet and the working model using an ethylene vinyl acetate sheet prepared by extrusion. Mouthguards were fabricated with EVA sheets (4.0 mm thick) using a vacuum-forming machine. Two forming conditions were compared: the square sheet was pinched by the clamping frame attached to the forming machine (S); and the round sheet was pinched at the top and bottom and stabilized by the circle tray (R). The sheet was aligned to make the sheet's extrusion direction vertical (V) or parallel (P) to the midline of the working model. The following two heating conditions were compared: (i) the sheet was molded when it sagged 15 mm below the level of the sheet frame measured at the top of the post in condition S (S-0), or that sagged 10 mm in condition R (R-0) in the usual position; (ii) the sheet frame was lowered by 50 mm from the ordinary height (S-50, R-50). Postmolding thickness was determined using a measuring device. Measurement points were the incisal and molar portion. Differences in the change of thickness of mouthguards molded under different heating conditions and extrusion directions for each sheet shape were analyzed by two-way analysis of variance (anova). The results of this study showed that by lowering the height of the sheet frame, the difference of the sheet temperature of each part was reduced. Among all sheets, condition V produced under S-50 and R-50 had the largest thickness independently of shape sheet. Furthermore, thickness reduction is effectively suppressed by aligning the direction of the extruded sheet to be vertical to the midline of the model. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  3. Cardiac size of high-volume resistance trained female athletes: shaping the body but not the heart.

    Science.gov (United States)

    Venckunas, T; Simonavicius, J; Marcinkeviciene, J E

    2016-03-01

    Introduction Exercise training, besides many health benefits, may result in cardiac remodelling which is dependent on the type and amount of exercise performed. It is not clear, however, whether significant adaptation in cardiac structure is possible in females undergoing resistance type of exercise training. Rigorous high volume training of most muscle groups emphasising resistance exercises are being undertaken by athletes of some aesthetic sports such as female fitness (light bodybuilding). The impact of this type of training on cardiac adaptation has not been investigated until now. The aim of the current study was to disclose the effect of high volume resistance training on cardiac structure and function. Methods 11 top-level female fitness athletes and 20 sedentary age-matched controls were recruited to undergo two-dimensional echocardiography. Results Cardiac structure did not differ between elite female fitness athletes and controls (p > 0.05), and fitness athletes had a tendency for a smaller (p = 0.07) left ventricular (LV) mass indexed to lean body mass. Doppler diastolic function index (E/A ratio) and LV ejection fraction were similar between the groups (p > 0.05). Conclusions Elite female fitness athletes have normal cardiac size and function that do not differ from matched sedentary controls. Consequently, as high volume resistance training has no easily observable effect on adaptation of cardiac structure, when cardiac hypertrophy is present in young resistance-trained lean female, other reasons such as inherited cardiac disease are to be considered carefully.

  4. Complex Ancestries of Lager-Brewing Hybrids Were Shaped by Standing Variation in the Wild Yeast Saccharomyces eubayanus.

    Science.gov (United States)

    Peris, David; Langdon, Quinn K; Moriarty, Ryan V; Sylvester, Kayla; Bontrager, Martin; Charron, Guillaume; Leducq, Jean-Baptiste; Landry, Christian R; Libkind, Diego; Hittinger, Chris Todd

    2016-07-01

    Lager-style beers constitute the vast majority of the beer market, and yet, the genetic origin of the yeast strains that brew them has been shrouded in mystery and controversy. Unlike ale-style beers, which are generally brewed with Saccharomyces cerevisiae, lagers are brewed at colder temperatures with allopolyploid hybrids of Saccharomyces eubayanus x S. cerevisiae. Since the discovery of S. eubayanus in 2011, additional strains have been isolated from South America, North America, Australasia, and Asia, but only interspecies hybrids have been isolated in Europe. Here, using genome sequence data, we examine the relationships of these wild S. eubayanus strains to each other and to domesticated lager strains. Our results support the existence of a relatively low-diversity (π = 0.00197) lineage of S. eubayanus whose distribution stretches across the Holarctic ecozone and includes wild isolates from Tibet, new wild isolates from North America, and the S. eubayanus parents of lager yeasts. This Holarctic lineage is closely related to a population with higher diversity (π = 0.00275) that has been found primarily in South America but includes some widely distributed isolates. A second diverse South American population (π = 0.00354) and two early-diverging Asian subspecies are more distantly related. We further show that no single wild strain from the Holarctic lineage is the sole closest relative of lager yeasts. Instead, different parts of the genome portray different phylogenetic signals and ancestry, likely due to outcrossing and incomplete lineage sorting. Indeed, standing genetic variation within this wild Holarctic lineage of S. eubayanus is responsible for genetic variation still segregating among modern lager-brewing hybrids. We conclude that the relationships among wild strains of S. eubayanus and their domesticated hybrids reflect complex biogeographical and genetic processes.

  5. Complex Ancestries of Lager-Brewing Hybrids Were Shaped by Standing Variation in the Wild Yeast Saccharomyces eubayanus.

    Directory of Open Access Journals (Sweden)

    David Peris

    2016-07-01

    Full Text Available Lager-style beers constitute the vast majority of the beer market, and yet, the genetic origin of the yeast strains that brew them has been shrouded in mystery and controversy. Unlike ale-style beers, which are generally brewed with Saccharomyces cerevisiae, lagers are brewed at colder temperatures with allopolyploid hybrids of Saccharomyces eubayanus x S. cerevisiae. Since the discovery of S. eubayanus in 2011, additional strains have been isolated from South America, North America, Australasia, and Asia, but only interspecies hybrids have been isolated in Europe. Here, using genome sequence data, we examine the relationships of these wild S. eubayanus strains to each other and to domesticated lager strains. Our results support the existence of a relatively low-diversity (π = 0.00197 lineage of S. eubayanus whose distribution stretches across the Holarctic ecozone and includes wild isolates from Tibet, new wild isolates from North America, and the S. eubayanus parents of lager yeasts. This Holarctic lineage is closely related to a population with higher diversity (π = 0.00275 that has been found primarily in South America but includes some widely distributed isolates. A second diverse South American population (π = 0.00354 and two early-diverging Asian subspecies are more distantly related. We further show that no single wild strain from the Holarctic lineage is the sole closest relative of lager yeasts. Instead, different parts of the genome portray different phylogenetic signals and ancestry, likely due to outcrossing and incomplete lineage sorting. Indeed, standing genetic variation within this wild Holarctic lineage of S. eubayanus is responsible for genetic variation still segregating among modern lager-brewing hybrids. We conclude that the relationships among wild strains of S. eubayanus and their domesticated hybrids reflect complex biogeographical and genetic processes.

  6. Automated compromised right lung segmentation method using a robust atlas-based active volume model with sparse shape composition prior in CT.

    Science.gov (United States)

    Zhou, Jinghao; Yan, Zhennan; Lasio, Giovanni; Huang, Junzhou; Zhang, Baoshe; Sharma, Navesh; Prado, Karl; D'Souza, Warren

    2015-12-01

    To resolve challenges in image segmentation in oncologic patients with severely compromised lung, we propose an automated right lung segmentation framework that uses a robust, atlas-based active volume model with a sparse shape composition prior. The robust atlas is achieved by combining the atlas with the output of sparse shape composition. Thoracic computed tomography images (n=38) from patients with lung tumors were collected. The right lung in each scan was manually segmented to build a reference training dataset against which the performance of the automated segmentation method was assessed. The quantitative results of this proposed segmentation method with sparse shape composition achieved mean Dice similarity coefficient (DSC) of (0.72, 0.81) with 95% CI, mean accuracy (ACC) of (0.97, 0.98) with 95% CI, and mean relative error (RE) of (0.46, 0.74) with 95% CI. Both qualitative and quantitative comparisons suggest that this proposed method can achieve better segmentation accuracy with less variance than other atlas-based segmentation methods in the compromised lung segmentation. Published by Elsevier Ltd.

  7. Impact of a Common Genetic Variation Associated With Putamen Volume on Neural Mechanisms of Attention-Deficit/Hyperactivity Disorder.

    Science.gov (United States)

    Xu, Bing; Jia, Tianye; Macare, Christine; Banaschewski, Tobias; Bokde, Arun L W; Bromberg, Uli; Büchel, Christian; Cattrell, Anna; Conrod, Patricia J; Flor, Herta; Frouin, Vincent; Gallinat, Jürgen; Garavan, Hugh; Gowland, Penny; Heinz, Andreas; Ittermann, Bernd; Martinot, Jean-Luc; Paillère Martinot, Marie-Laure; Nees, Frauke; Orfanos, Dimitri Papadopoulos; Paus, Tomáš; Poustka, Luise; Smolka, Michael N; Walter, Henrik; Whelan, Robert; Schumann, Gunter; Desrivières, Sylvane

    2017-05-01

    In a recent genomewide association study of subcortical brain volumes, a common genetic variation at rs945270 was identified as having the strongest effect on putamen volume, a brain measurement linked to familial risk for attention-deficit/hyperactivity disorder (ADHD). To determine whether rs945270 might be a genetic determinant of ADHD, its effects on ADHD-related symptoms and neural mechanisms of ADHD, such as response inhibition and reward sensitivity, were explored. A large population sample of 1,834 14-year-old adolescents was used to test the effects of rs945270 on ADHD symptoms assessed through the Strengths and Difficulties Questionnaire and region-of-interest analyses of putamen activation by functional magnetic resonance imaging using the stop signal and monetary incentive delay tasks, assessing response inhibition and reward sensitivity, respectively. There was a significant link between rs945270 and ADHD symptom scores, with the C allele associated with lower symptom scores, most notably hyperactivity. In addition, there were sex-specific effects of this variant on the brain. In boys, the C allele was associated with lower putamen activity during successful response inhibition, a brain response that was not associated with ADHD symptoms. In girls, putamen activation during reward anticipation increased with the number of C alleles, most significantly in the right putamen. Remarkably, right putamen activation during reward anticipation tended to negatively correlate with ADHD symptoms. These results indicate that rs945270 might contribute to the genetic risk of ADHD partly through its effects on hyperactivity and reward processing in girls. Copyright © 2017 American Academy of Child and Adolescent Psychiatry. All rights reserved.

  8. Surface area and the seabed area, volume, depth, slope, and topographic variation for the world's seas, oceans, and countries.

    Science.gov (United States)

    Costello, Mark John; Cheung, Alan; De Hauwere, Nathalie

    2010-12-01

    Depth and topography directly and indirectly influence most ocean environmental conditions, including light penetration and photosynthesis, sedimentation, current movements and stratification, and thus temperature and oxygen gradients. These parameters are thus likely to influence species distribution patterns and productivity in the oceans. They may be considered the foundation for any standardized classification of ocean ecosystems and important correlates of metrics of biodiversity (e.g., species richness and composition, fisheries). While statistics on ocean depth and topography are often quoted, how they were derived is rarely cited, and unless calculated using the same spatial resolution the resulting statistics will not be strictly comparable. We provide such statistics using the best available resolution (1-min) global bathymetry, and open source digital maps of the world's seas and oceans and countries' Exclusive Economic Zones, using a standardized methodology. We created a terrain map and calculated sea surface and seabed area, volume, and mean, standard deviation, maximum, and minimum, of both depth and slope. All the source data and our database are freely available online. We found that although the ocean is flat, and up to 71% of the area has a ocean volume exceeds 1.3 billion km(3) (or 1.3 sextillion liters), and sea surface and seabed areas over 354 million km(2). We propose the coefficient of variation of slope as an index of topographic heterogeneity. Future studies may improve on this database, for example by using a more detailed bathymetry, and in situ measured data. The database could be used to classify ocean features, such as abyssal plains, ridges, and slopes, and thus provide the basis for a standards based classification of ocean topography.

  9. Observer variation in target volume delineation of lung cancer related to radiation oncologist-computer interaction: a 'Big Brother' evaluation.

    Science.gov (United States)

    Steenbakkers, Roel J H M; Duppen, Joop C; Fitton, Isabelle; Deurloo, Kirsten E I; Zijp, Lambert; Uitterhoeve, Apollonia L J; Rodrigus, Patrick T R; Kramer, Gijsbert W P; Bussink, Johan; De Jaeger, Katrien; Belderbos, José S A; Hart, Augustinus A M; Nowak, Peter J C M; van Herk, Marcel; Rasch, Coen R N

    2005-11-01

    To evaluate the process of target volume delineation in lung cancer for optimization of imaging, delineation protocol and delineation software. Eleven radiation oncologists (observers) from five different institutions delineated the Gross Tumor Volume (GTV) including positive lymph nodes of 22 lung cancer patients (stages I-IIIB) on CT only. All radiation oncologist-computer interactions were recorded with a tool called 'Big Brother'. For each radiation oncologist and patient the following issues were analyzed: delineation time, number of delineated points and corrections, zoom levels, level and window (L/W) settings, CT slice changes, use of side windows (coronal and sagittal) and software button use. The mean delineation time per GTV was 16 min (SD 10 min). The mean delineation time for lymph node positive patients was on average 3 min larger (P = 0.02) than for lymph node negative patients. Many corrections (55%) were due to L/W change (e.g. delineating in mediastinum L/W and then correcting in lung L/W). For the lymph node region, a relatively large number of corrections was found (3.7 corr/cm2), indicating that it was difficult to delineate lymph nodes. For the tumor-atelectasis region, a relative small number of corrections was found (1.0 corr/cm2), indicating that including or excluding atelectasis into the GTV was a clinical decision. Inappropriate use of L/W settings was frequently found (e.g. 46% of all delineated points in the tumor-lung region were delineated in mediastinum L/W settings). Despite a large observer variation in cranial and caudal direction of 0.72 cm (1 SD), the coronal and sagittal side windows were not used in 45 and 60% of the cases, respectively. For the more difficult cases, observer variation was smaller when the coronal and sagittal side windows were used. With the 'Big Brother' tool a method was developed to trace the delineation process. The differences between observers concerning the delineation style were large. This study led

  10. History, geography and host use shape genomewide patterns of genetic variation in the redheaded pine sawfly (Neodiprion lecontei).

    Science.gov (United States)

    Bagley, Robin K; Sousa, Vitor C; Niemiller, Matthew L; Linnen, Catherine R

    2017-02-01

    Divergent host use has long been suspected to drive population differentiation and speciation in plant-feeding insects. Evaluating the contribution of divergent host use to genetic differentiation can be difficult, however, as dispersal limitation and population structure may also influence patterns of genetic variation. In this study, we use double-digest restriction-associated DNA (ddRAD) sequencing to test the hypothesis that divergent host use contributes to genetic differentiation among populations of the redheaded pine sawfly (Neodiprion lecontei), a widespread pest that uses multiple Pinus hosts throughout its range in eastern North America. Because this species has a broad range and specializes on host plants known to have migrated extensively during the Pleistocene, we first assess overall genetic structure using model-based and model-free clustering methods and identify three geographically distinct genetic clusters. Next, using a composite-likelihood approach based on the site frequency spectrum and a novel strategy for maximizing the utility of linked RAD markers, we infer the population topology and date divergence to the Pleistocene. Based on existing knowledge of Pinus refugia, estimated demographic parameters and patterns of diversity among sawfly populations, we propose a Pleistocene divergence scenario for N. lecontei. Finally, using Mantel and partial Mantel tests, we identify a significant relationship between genetic distance and geography in all clusters, and between genetic distance and host use in two of three clusters. Overall, our results indicate that Pleistocene isolation, dispersal limitation and ecological divergence all contribute to genomewide differentiation in this species and support the hypothesis that host use is a common driver of population divergence in host-specialized insects. © 2016 John Wiley & Sons Ltd.

  11. Intraoperative monitoring of stroke volume variation versus central venous pressure in laparoscopic liver surgery: a randomized prospective comparative trial.

    Science.gov (United States)

    Ratti, Francesca; Cipriani, Federica; Reineke, Raffaella; Catena, Marco; Paganelli, Michele; Comotti, Laura; Beretta, Luigi; Aldrighetti, Luca

    2016-02-01

    Central venous pressure (CVP) is used as a marker of cardiac preload to control intraoperative blood loss in open hepatectomies, while its reliability in laparoscopy is less certain. The aim of this randomized prospective trial was to evaluate the outcome of laparoscopic resections performed with stroke volume variation (SVV) or CVP monitoring. All candidates for laparoscopic liver resection were assigned randomly to SVV or to CVP groups. Outcome was evaluated included conversion rate, cause of conversion, intraoperative blood loss, need for transfusions, length of surgery and postoperative results. Ninety consecutive patients were enrolled: both SVV and CVP groups included 45 patients each and were comparable in terms of patient and disease characteristics. A reduced rate of conversion was recorded in the SVV compared to the CVP group (6.7% and 17.8% respectively, p = 0.02). Blood loss was lower in the SVV group (150 mL), compared to the CVP group (300 mL, p = 0.04). Morbidity, mortality, length of stay and functional recovery were comparable. On multivariate analysis, lesion location, extent of hepatectomy and type of cardiac preload monitoring were associated significantly to risk of conversion. SVV monitoring in laparoscopic liver surgery improves intraoperative outcome, thus enhancing the benefits of the minimally-invasive approach and fast-track protocols. Copyright © 2015 International Hepato-Pancreato-Biliary Association Inc. Published by Elsevier Ltd. All rights reserved.

  12. Correlation of centroid-based breast size, surface-based breast volume, and asymmetry-score-based breast symmetry in three-dimensional breast shape analysis

    Directory of Open Access Journals (Sweden)

    Henseler, Helga

    2016-06-01

    Full Text Available Objective: The aim of this study was to investigate correlations among the size, volume, and symmetry of the female breast after reconstruction based on previously published data. Methods: The centroid, namely the geometric center of a three-dimensional (3D breast-landmark-based configuration, was used to calculate the size of the breast. The surface data of the 3D breast images were used to measure the volume. Breast symmetry was assessed by the Procrustes analysis method, which is based on the 3D coordinates of the breast landmarks to produce an asymmetry score. The relationship among the three measurements was investigated. For this purpose, the data of 44 patients who underwent unilateral breast reconstruction with an extended latissimus dorsi flap were analyzed. The breast was captured by a validated 3D imaging system using multiple cameras. Four landmarks on each breast and two landmarks marking the midline were used.Results: There was a significant positive correlation between the centroid-based breast size of the unreconstructed breast and the measured asymmetry (p=0.024; correlation coefficient, 0.34. There was also a significant relationship between the surface-based breast volume of the unaffected side and the overall asymmetry score (p<0.001; correlation coefficient, 0.556. An increase in size and especially in volume of the unreconstructed breast correlated positively with an increase in breast asymmetry in a linear relationship.Conclusions: In breast shape analysis, the use of more detailed surface-based data should be preferred to centroid-based size data. As the breast size increases, the latissimus dorsi flap for unilateral breast reconstruction increasingly falls short in terms of matching the healthy breast in a linear relationship. Other reconstructive options should be considered for larger breasts. Generally plastic surgeons should view the two breasts as a single unit when assessing breast aesthetics and not view each

  13. Clear-cornea cataract surgery: pupil size and shape changes, along with anterior chamber volume and depth changes. A Scheimpflug imaging study

    Directory of Open Access Journals (Sweden)

    Kanellopoulos AJ

    2014-10-01

    Full Text Available Anastasios John Kanellopoulos,1,2 George Asimellis11Laservision.gr Eye Institute, Athens, Greece; 2New York University School of Medicine, New York, NY, USA Purpose: To investigate, by high-precision digital analysis of data provided by Scheimpflug imaging, changes in pupil size and shape and anterior chamber (AC parameters following cataract surgery.Patients and methods: The study group (86 eyes, patient age 70.58±10.33 years was subjected to cataract removal surgery with in-the-bag intraocular lens implantation (pseudophakic. A control group of 75 healthy eyes (patient age 51.14±16.27 years was employed for comparison. Scheimpflug imaging (preoperatively and 3 months postoperatively was employed to investigate central corneal thickness, AC depth, and AC volume. In addition, by digitally analyzing the black-and-white dotted line pupil edge marking in the Scheimpflug “large maps,” the horizontal and vertical pupil diameters were individually measured and the pupil eccentricity was calculated. The correlations between AC depth and pupil shape parameters versus patient age, as well as the postoperative AC and pupil size and shape changes, were investigated.Results: Compared to preoperative measurements, AC depth and AC volume of the pseudophakic eyes increased by 0.99±0.46 mm (39%; P<0.001 and 43.57±24.59 mm3 (36%; P<0.001, respectively. Pupil size analysis showed that the horizontal pupil diameter was reduced by -0.27±0.22 mm (-9.7%; P=0.001 and the vertical pupil diameter was reduced by -0.32±0.24 mm (-11%; P<0.001. Pupil eccentricity was reduced by -39.56%; P<0.001.Conclusion: Cataract extraction surgery appears to affect pupil size and shape, possibly in correlation to AC depth increase. This novel investigation based on digital analysis of Scheimpflug imaging data suggests that the cataract postoperative photopic pupil is reduced and more circular. These changes appear to be more significant with increasing patient age. Keywords

  14. Goal-directed fluid optimization based on stroke volume variation and cardiac index during one-lung ventilation in patients undergoing thoracoscopy lobectomy operations: a pilot study.

    Science.gov (United States)

    Zhang, Jian; Chen, Chao Qin; Lei, Xiu Zhen; Feng, Zhi Ying; Zhu, Sheng Mei

    2013-07-01

    This pilot study was designed to utilize stroke volume variation and cardiac index to ensure fluid optimization during one-lung ventilation in patients undergoing thoracoscopic lobectomies. Eighty patients undergoing thoracoscopic lobectomy were randomized into either a goal-directed therapy group or a control group. In the goal-directed therapy group, the stroke volume variation was controlled at 10%±1%, and the cardiac index was controlled at a minimum of 2.5 L.min-1.m-2. In the control group, the MAP was maintained at between 65 mm Hg and 90 mm Hg, heart rate was maintained at between 60 BPM and 100 BPM, and urinary output was greater than 0.5 mL/kg-1/h-1. The hemodynamic variables, arterial blood gas analyses, total administered fluid volume and side effects were recorded. The PaO2/FiO2-ratio before the end of one-lung ventilation in the goal-directed therapy group was significantly higher than that of the control group, but there were no differences between the goal-directed therapy group and the control group for the PaO2/FiO2-ratio or other arterial blood gas analysis indices prior to anesthesia. The extubation time was significantly earlier in the goal-directed therapy group, but there was no difference in the length of hospital stay. Patients in the control group had greater urine volumes, and they were given greater colloid and overall fluid volumes. Nausea and vomiting were significantly reduced in the goal-directed therapy group. The results of this study demonstrated that an optimization protocol, based on stroke volume variation and cardiac index obtained with a FloTrac/Vigileo device, increased the PaO2/FiO2-ratio and reduced the overall fluid volume, intubation time and postoperative complications (nausea and vomiting) in thoracic surgery patients requiring one-lung ventilation.

  15. Pulse Pressure Variation Adjusted by Respiratory Changes in Pleural Pressure, Rather Than by Tidal Volume, Reliably Predicts Fluid Responsiveness in Patients With Acute Respiratory Distress Syndrome.

    Science.gov (United States)

    Liu, Yang; Wei, Lu-qing; Li, Guo-qiang; Yu, Xin; Li, Guo-feng; Li, Yu-ming

    2016-02-01

    1) To evaluate the ability of pulse pressure variation adjusted by respiratory changes in pleural pressure to predict fluid responsiveness compared with pulse pressure variation alone. 2) To identify factors explaining the poor performance of pulse pressure variation in acute respiratory distress syndrome. Prospective study. Forty-bed university hospital general ICU. Ninety-six mechanically ventilated acute respiratory distress syndrome patients requiring fluid challenge. Fluid challenge, 500 mL saline over 20 minutes. Before fluid challenge, esophageal pressure was measured at the end-inspiratory and end-expiratory occlusions. Change in pleural pressure was calculated as the difference between esophageal pressure measured at end-inspiratory and end-expiratory occlusions. Hemodynamic measurements were obtained before and after the fluid challenge. Patients were ventilated with tidal volume 7.0 ± 0.8 mL/kg predicted body weight. The fluids increased cardiac output by greater than 15% in 52 patients (responders). Adjusting pulse pressure variation for changes in pleural pressure (area under the receiver operating characteristic curve, 0.94 [0.88-0.98]) and the ratio of chest wall elastance to total respiratory system elastance (area under the receiver operating characteristic curve, 0.93 [0.88-0.98]) predicted fluid responsiveness better than pulse pressure variation (area under the receiver operating characteristic curve, 0.78 [0.69-0.86]; all p variation/changes in pleural pressure values (1.94-2.1) in 3.1% of patients for whom fluid responsiveness could not be predicted reliably. On logistic regression analysis, two independent factors affected the correct classification of fluid responsiveness at a 12% pulse pressure variation cutoff: tidal volume (adjusted odds ratio 1.57/50 mL; 95% CI, 1.05-2.34; p = 0.027) and chest wall elastance/respiratory system elastance (adjusted odds ratio, 2.035/0.1 unit; 95% CI, 1.36-3.06; p = 0.001). In patients with chest wall

  16. Observer variation in target volume delineation of lung cancer related to radiation oncologist-computer interaction: a 'Big Brother' evaluation.

    NARCIS (Netherlands)

    Steenbakkers, R.J.; Duppen, J.C.; Fitton, I.; Deurloo, K.E.; Zijp, L.; Uitterhoeve, A.L.; Rodrigus, P.T.; Kramer, G.W.P.M.; Bussink, J.; Jaeger, K. de; Belderbos, J.S.; Hart, A.A.M.; Nowak, P.J.; Herk, M. van; Rasch, C.R.

    2005-01-01

    BACKGROUND AND PURPOSE: To evaluate the process of target volume delineation in lung cancer for optimization of imaging, delineation protocol and delineation software. PATIENTS AND METHODS: Eleven radiation oncologists (observers) from five different institutions delineated the Gross Tumor Volume

  17. Comparison of Pressure Changes by Head and Neck Position between High-Volume Low-Pressure and Taper-Shaped Cuffs: A Randomized Controlled Trial.

    Science.gov (United States)

    Komasawa, Nobuyasu; Mihara, Ryosuke; Imagawa, Kentaro; Hattori, Kazuo; Minami, Toshiaki

    2015-01-01

    The present study compared changes in cuff pressure by head and neck position between high-volume low-pressure (HVLP) and taper-shaped (taper) cuffs in a prospective randomized clinical trial. Methods. Forty patients were intubated using tracheal tubes with either HVLP (n = 20; HVLP group) or taper-shaped (n = 20; Taper group) cuffs. Initial cuff pressure was adjusted to 15, 20, or 25 cmH2O in the neutral position. Cuff pressure was evaluated after changing the head and neck positions to flexion, extension, and rotation. Results. Cuff pressure significantly increased with flexion in both HVLP and Taper groups at all initial cuff pressures. It significantly increased with extension in the HVLP group, but not in the Taper group. Cuff pressure did not significantly differ with rotation in either group and was significantly smaller in the Taper group during flexion and extension than in the HVLP group, regardless of initial cuff pressure. Conclusion. Cuff pressure changes with head and neck flexion and extension were smaller in the Taper group than in the HVLP group. Our results highlight the potential for taper cuffs to prevent excessive cuff pressure increases with positional changes in the head and neck. This trial is registered with UMIN000016119.

  18. Comparison of Pressure Changes by Head and Neck Position between High-Volume Low-Pressure and Taper-Shaped Cuffs: A Randomized Controlled Trial

    Directory of Open Access Journals (Sweden)

    Nobuyasu Komasawa

    2015-01-01

    Full Text Available The present study compared changes in cuff pressure by head and neck position between high-volume low-pressure (HVLP and taper-shaped (taper cuffs in a prospective randomized clinical trial. Methods. Forty patients were intubated using tracheal tubes with either HVLP (n=20; HVLP group or taper-shaped (n=20; Taper group cuffs. Initial cuff pressure was adjusted to 15, 20, or 25 cmH2O in the neutral position. Cuff pressure was evaluated after changing the head and neck positions to flexion, extension, and rotation. Results. Cuff pressure significantly increased with flexion in both HVLP and Taper groups at all initial cuff pressures. It significantly increased with extension in the HVLP group, but not in the Taper group. Cuff pressure did not significantly differ with rotation in either group and was significantly smaller in the Taper group during flexion and extension than in the HVLP group, regardless of initial cuff pressure. Conclusion. Cuff pressure changes with head and neck flexion and extension were smaller in the Taper group than in the HVLP group. Our results highlight the potential for taper cuffs to prevent excessive cuff pressure increases with positional changes in the head and neck. This trial is registered with UMIN000016119.

  19. The interstitial nuclei of the human anterior hypothalamus: an investigation of sexual variation in volume and cell size, number and density.

    Science.gov (United States)

    Byne, W; Lasco, M S; Kemether, E; Shinwari, A; Edgar, M A; Morgello, S; Jones, L B; Tobet, S

    2000-02-21

    The four interstitial nuclei of the anterior hypothalamus (INAH) have been considered as candidate human nuclei for homology with the much studied sexually dimorphic nucleus of the preoptic area of the rat. Assessment of the INAH for sexual dimorphism has produced discrepant results. This study reports the first systematic examination of all four INAH in the human for sexual variation in volume, neuronal number and neuronal size. Serial Nissl-stained coronal sections through the medial preoptic area and anterior hypothalamus were examined from 18 males and 20 females who died between the ages of 17 and 65 without evidence of hypothalamic pathology or infection with the human immunodeficiency virus. A computer-assisted image-analysis system and commercial stereology software package were employed to assess total volume, neuronal number and mean neuronal size for each INAH. INAH3 occupied a significantly greater volume and contained significantly more neurons in males than in females. No sex differences in volume were detected for any of the other INAH. No sexual variation in neuronal size or packing density was observed in any nucleus. The present data corroborate two previous reports of sexual dimorphism of INAH3 but provide no support for previous reports of sexual variation in other INAH.

  20. Inter-application variation of dose and spatial location of D(2cm(3)) volumes of OARs during MR image based cervix brachytherapy.

    Science.gov (United States)

    Jamema, Swamidas V; Mahantshetty, Umesh; Tanderup, Kari; Malvankar, Deepti; Sharma, Shilpa; Engineer, Reena; Chopra, Supriya; Shrivastava, Shyam K; Deshpande, Deepak D

    2013-04-01

    Evaluation of Inter-application variation of doses and spatial location of D(2cm(3)) volumes of OARs during MR-image based cervix brachytherapy. Twenty-seven patients treated with EMBRACE protocol were analyzed. Every patient had two applications, one week apart. For each application patient had undergone MR-imaging (MR-1 and MR-2), volume delineation, reconstruction, treatment planning (plan-1 and plan-2) and dose evaluation. Both the image series were then co-registered with applicator as the reference coordinate system (Eclipse planning system v8.6.14). Inter-application dose, volume and spatial location of D(2cm(3)) variation were evaluated. The largest inter-application systematic and random dose variations were observed for sigmoid as compared to rectum and bladder. The mean (±SD) of the relative D(2cm(3)) variations were 0.6(±15.1)%, 0.9(±13.1)% and 11.9(±37.5)% for rectum, bladder and sigmoid respectively. The overlap of D(2cm(3)) volumes was more than 50% in 16(59%), 8(30%) and 3(11%) patients for rectum, bladder and sigmoid, respectively. The 2cm(3) volumes between the applications/fractions are quite stable in topography for bladder and rectum, and hence the current practice of cumulative addition of D(2cm(3)) dose is expected to be valid for bladder and rectum. For sigmoid, significant topographical changes were seen, which need further validation in a larger patient population and in multi-centric settings. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  1. Outcomes associated with stroke volume variation versus central venous pressure guided fluid replacements during major abdominal surgery

    Directory of Open Access Journals (Sweden)

    Lakshmi Kumar

    2016-01-01

    Full Text Available Background and Aims: There is limited data on the impact of perioperative fluid therapy guided by dynamic preload variables like stroke volume variation (SVV on outcomes after abdominal surgery. We studied the effect of SVV guided versus central venous pressure (CVP guided perioperative fluid administration on outcomes after major abdominal surgery. Material and Methods: Sixty patients undergoing major abdominal surgeries were randomized into two equal groups in this prospective single blind randomized study. In the standard care group, the CVP was maintained at 10-12 mmHg while in the intervention group a SVV of 10% was achieved by the administration of fluids. The primary end-points were the length of Intensive Care Unit (ICU and hospital stay. The secondary end points were intraoperative lactate, intravenous fluid use, requirement for inotropes, postoperative ventilation and return of bowel function. Results: The ICU stay was significantly shorter in the intervention group as compared to the control group (2.9 ± 1.15 vs. 5.4 ± 2.71 days. The length of hospital stay was also shorter in the intervention group, (9.9 ± 2.68 vs. 11.96 ± 5.15 days though not statistically significant. The use of intraoperative fluids was significantly lower in the intervention group than the control group (7721.5 ± 4138.9 vs. 9216.33 ± 2821.38 ml. Other secondary outcomes were comparable between the two groups. Conclusion: Implementation of fluid replacement guided by a dynamic preload variable (SVV versus conventional static variables (CVP is associated with lesser postoperative ICU stay and reduced fluid requirements in major abdominal surgery.

  2. [Hospital variation in anastomotic leakage after rectal cancer surgery in the Spanish Association of Surgeons project: The contribution of hospital volume].

    Science.gov (United States)

    Ortiz, Héctor; Biondo, Sebastiano; Codina, Antonio; Ciga, Miguel Á; Enríquez-Navascués, José; Espín, Eloy; García-Granero, Eduardo; Roig, José Vicente

    2016-04-01

    This multicentre observational study aimed to determine the anastomotic leak rate in the hospitals included in the Rectal Cancer Project of the Spanish Society of Surgeons and examine whether hospital volume may contribute to any variation between hospitals. Hospital variation was quantified using a multilevel approach on prospective data derived from the multicentre database of all adenocarcinomas of the rectum operated by an anterior resection at 84 surgical departments from 2006 to 2013. The following variables were included in the analysis; demographics, American Society of Anaesthesiologists classification, use of defunctioning stoma, tumour location and stage, administration of neoadjuvant treatment, and annual volume of elective surgical procedures. A total of 7231 consecutive patients were included. The rate of anastomotic leak was 10.0%. Stratified by annual surgical volume hospitals varied from 9.9 to 11.3%. In multilevel regression analysis, the risk of anastomotic leak increased in male patients, in patients with tumours located below 12 cm from the anal verge, and advanced tumour stages. However, a defunctioning stoma seemed to prevent this complication. Hospital surgical volume was not associated with anastomotic leak (OR: 0.852, [0.487-1.518]; P=.577). Furthermore, there was a statistically significant variation in anastomotic leak between all departments (MOR: 1.475; [1.321-1.681]; P<0.001). Anastomotic leak varies significantly among hospitals included in the project and this difference cannot be attributed to the annual surgical volume. Copyright © 2015 AEC. Publicado por Elsevier España, S.L.U. All rights reserved.

  3. SU-C-210-06: Quantitative Evaluation of Dosimetric Effects Resulting From Positional Variations of Pancreatic Tumor Volumes

    Energy Technology Data Exchange (ETDEWEB)

    Yu, S; Sehgal, V; Wei, R; Lawrenson, L; Kuo, J; Hanna, N; Ramsinghani, N; Daroui, P; Al-Ghazi, M [University of California, Orange, CA (United States)

    2015-06-15

    Purpose: The aim of this study is to quantify dosimetric effects resulting from variation in pancreatic tumor position assessed by bony anatomy and implanted fiducial markers Methods: Twelve pancreatic cancer patients were retrospectively analyzed for this study. All patients received modulated arc therapy (VMAT) treatment using fiducial-based Image Guided Radiation Therapy (IGRT) to the intact pancreas. Using daily orthogonal kV and/or Cone beam CT images, the shift needed to co-register the daily pre-treatment images to reference CT from fiducial to bone (Fid-Bone) were recorded as Left-Right (LR), Anterior-Posterior (AP) and Superior-Inferior (SI). The original VMAT plan iso-center was shifted based on KV bone matching positions at 5 evenly spaced fractions. Dose coverage of the planning target volumes (PTVs) (V100%), mean dose to liver, kidney and stomach/duodenum were assessed in the modified plans. Results: A total of 306 fractions were analyzed. The absolute fiducial-bone positional shifts were greatest in the SI direction, (AP = 2.7 ± 3.0, LR = 2.8 ± 2.8, and SI 6.3 ± 7.9 mm, mean ± SD). The V100% was significantly reduced by 13.5%, (Fid-Bone = 95.3 ± 2.0 vs. 82.3 ± 11.8%, p=0.02). This varied widely among patients (Fid-Bone V100% Range = 2–60%), where 33% of patients had a reduction in V100% of more than 10%. The impact on OARs was greatest to the liver (Fid-Bone= 14.6 vs. 16.1 Gy, 10%), and stomach, (Fid-Bone = 23.9 vx. 25.5 Gy, 7%), however was not statistically significant (p=0.10 both). Conclusion: Compared to matching by fiducial markers, matching by bony anatomy would have substantially reduced the PTV coverage by 13.5%. This reinforces the importance of online position verification based on fiducial markers. Hence, implantation of fiducial markers is strongly recommended for pancreatic cancer patients undergoing intensity modulated radiation therapy treatments.

  4. Exploring Conceptual Frameworks of Models of Atomic Structures and Periodic Variations, Chemical Bonding, and Molecular Shape and Polarity: A Comparison of Undergraduate General Chemistry Students with High and Low Levels of Content Knowledge

    Science.gov (United States)

    Wang, Chia-Yu; Barrow, Lloyd H.

    2013-01-01

    The purpose of the study was to explore students' conceptual frameworks of models of atomic structure and periodic variations, chemical bonding, and molecular shape and polarity, and how these conceptual frameworks influence their quality of explanations and ability to shift among chemical representations. This study employed a purposeful sampling…

  5. A topology-based method to mitigate the dosimetric uncertainty caused by the positional variation of the boost volume in breast conservative radiotherapy.

    Science.gov (United States)

    Lee, Peng-Yi; Lin, Chih-Yuan; Chen, Shang-Wen; Chien, Chun-Ru; Chu, Chun-Nan; Hsu, Hsiu-Ting; Liang, Ji-An; Lin, Ying-Jun; Shiau, An-Cheng

    2017-03-20

    To improve local control rate in patients with breast cancer receiving adjuvant radiotherapy after breast conservative surgery, additional boost dose to the tumor bed could be delivered simultaneously via the simultaneous integrated boost (SIB) modulated technique. However, the position of tumor bed kept changing during the treatment course as the treatment position was aligned to bony anatomy. This study aimed to analyze the positional uncertainties between bony anatomy and tumor bed, and a topology-based approach was derived to stratify patients with high variation in tumor bed localization. Sixty patients with early-stage breast cancer or ductal carcinoma in situ were enrolled. All received adjuvant whole breast radiotherapy with or without local boost via SIB technique. The delineation of tumor bed was defined by incorporating the anatomy of seroma, adjacent surgical clips, and any architectural distortion on computed tomography simulation. A total of 1740 on-board images were retrospectively analyzed. Positional uncertainty of tumor bed was assessed by four components: namely systematic error (SE), and random error (RE), through anterior-posterior (AP), cranial-caudal (CC), left-right (LR) directions and couch rotation (CR). Age, tumor location, and body-mass factors including volume of breast, volume of tumor bed, breast thickness, and body mass index (BMI) were analyzed for their predictive role. The appropriate margin to accommodate the positional uncertainty of the boost volume was assessed, and the new plans with this margin for the tumor bed was designed as the high risk planning target volume (PTV-H) were created retrospectively to evaluate the impact on organs at risk. In univariate analysis, a larger breast thickness, larger breast volume, higher BMI, and different tumor locations correlated with a greater positional uncertainty of tumor bed. However, BMI was the only factor associated with displacements of surgical clips in the multivariate analysis

  6. Discriminative Shape Alignment

    DEFF Research Database (Denmark)

    Loog, M.; de Bruijne, M.

    2009-01-01

    The alignment of shape data to a common mean before its subsequent processing is an ubiquitous step within the area shape analysis. Current approaches to shape analysis or, as more specifically considered in this work, shape classification perform the alignment in a fully unsupervised way......, not taking into account that eventually the shapes are to be assigned to two or more different classes. This work introduces a discriminative variation to well-known Procrustes alignment and demonstrates its benefit over this classical method in shape classification tasks. The focus is on two...

  7. Goal-directed fluid optimization based on stroke volume variation and cardiac index during one-lung ventilation in patients undergoing thoracoscopy lobectomy operations: a pilot study

    Directory of Open Access Journals (Sweden)

    Jian Zhang

    2013-07-01

    Full Text Available OBJECTIVES: This pilot study was designed to utilize stroke volume variation and cardiac index to ensure fluid optimization during one-lung ventilation in patients undergoing thoracoscopic lobectomies. METHODS: Eighty patients undergoing thoracoscopic lobectomy were randomized into either a goal-directed therapy group or a control group. In the goal-directed therapy group, the stroke volume variation was controlled at 10%±1%, and the cardiac index was controlled at a minimum of 2.5 L.min-1.m-2. In the control group, the MAP was maintained at between 65 mm Hg and 90 mm Hg, heart rate was maintained at between 60 BPM and 100 BPM, and urinary output was greater than 0.5 mL/kg-1/h-1. The hemodynamic variables, arterial blood gas analyses, total administered fluid volume and side effects were recorded. RESULTS: The PaO2/FiO2-ratio before the end of one-lung ventilation in the goal-directed therapy group was significantly higher than that of the control group, but there were no differences between the goal-directed therapy group and the control group for the PaO2/FiO2-ratio or other arterial blood gas analysis indices prior to anesthesia. The extubation time was significantly earlier in the goal-directed therapy group, but there was no difference in the length of hospital stay. Patients in the control group had greater urine volumes, and they were given greater colloid and overall fluid volumes. Nausea and vomiting were significantly reduced in the goal-directed therapy group. CONCLUSION: The results of this study demonstrated that an optimization protocol, based on stroke volume variation and cardiac index obtained with a FloTrac/Vigileo device, increased the PaO2/FiO2-ratio and reduced the overall fluid volume, intubation time and postoperative complications (nausea and vomiting in thoracic surgery patients requiring one-lung ventilation.

  8. Extravascular Lung Water Does Not Increase in Hypovolemic Patients after a Fluid-Loading Protocol Guided by the Stroke Volume Variation

    Directory of Open Access Journals (Sweden)

    Carlos Ferrando

    2012-01-01

    Full Text Available Introduction. Circulatory failure secondary to hypovolemia is a common situation in critical care patients. Volume replacement is the first option for the treatment of hypovolemia. A possible complication of volume loading is pulmonary edema, quantified at the bedside by the measurement of extravascular lung water index (ELWI. ELWI predicts progression to acute lung injury (ALI in patients with risk factors for developing it. The aim of this study was to assess whether fluid loading guided by the stroke volume variation (SVV, in patients presumed to be hypovolemic, increased ELWI or not. Methods. Prospective study of 17 consecutive postoperative, fully mechanically ventilated patients diagnosed with circulatory failure secondary to presumed hypovolemia were included. Cardiac index (CI, ELWI, SVV, and global end-diastolic volume index (GEDI were determined using the transpulmonary thermodilution technique during the first 12 hours after fluid loading. Volume replacement was done with a strict hemodynamic protocol. Results. Fluid loading produced a significant increase in CI and a decrease in SVV. ELWI did not increase. No correlation was found between the amount of fluids administered and the change in ELWI. Conclusion. Fluid loading guided by SVV in hypovolemic and fully mechanically ventilated patients in sinus rhythm does not increase ELWI.

  9. Retro-nasal aroma release is correlated with variations in the in-mouth air cavity volume after empty deglutition.

    Science.gov (United States)

    Mishellany-Dutour, Anne; Woda, Alain; Labouré, Hélène; Bourdiol, Pierre; Lachaze, Pauline; Guichard, Elisabeth; Feron, Gilles

    2012-01-01

    We hypothesized that interindividual differences in motor activities during chewing and/or swallowing were determining factors for the transfer of volatile aroma from the in-mouth air cavity (IMAC) toward the olfactory mucosa. In our first experiment, we looked for changes in IMAC volume after saliva deglutition in 12 healthy subjects. The mean IMAC volume was measured after empty deglutition using an acoustic pharyngometer device. Based on the time course of the IMAC volume after swallowing, we discerned two groups of subjects. The first group displayed a small, constant IMAC volume (2.26 mL ±0.62) that corresponded to a high tongue position. The second group displayed a progressive increase in IMAC (from 6.82 mL ±2.37 to 22.82 mL ±3.04) that corresponded to a progressive lowering of the tongue to its resting position. In our second experiment, we investigated the relationship between IMAC volume changes after deglutition and the level of aroma release at the nostril. For this purpose, the release of menthone was measured at the nostril level in 25 subjects who consumed similar amounts of a mint tablet. The subjects were separated into two groups corresponding to two levels of menthone release: high (H) and low (L). The mean volume of IMAC was measured during and after empty deglutition. Group H displayed a small, constant amplitude of IMAC volume change after deglutition, while Group L displayed a progressive increase in IMAC. It is likely that Group H continuously released the aroma through the veloglossal isthmus as the mint was consumed, while Group L trapped the aroma in the oral cavity and then released it into the nasal cavity upon swallowing. These results show that the in vivo aroma release profile in humans depends closely on the different motor patterns at work during empty deglutition.

  10. Fluctuating Asymmetry and Individual Variation in Regional Gray and White Matter Volumes: A Voxel-Based Morphometry Study

    Directory of Open Access Journals (Sweden)

    Matthew Euler

    2008-10-01

    Full Text Available Composite measures of fluctuating asymmetry (FA of skeletal features are commonly used to estimate developmental instability (DI, the imprecise expression of developmental design due to perturbations during an individual's growth and maturation. Though many studies have detailed important behavioral correlates of FA, very little is known about its possible neuroanatomical correlates. In this study we obtained structural brain MRI scans from 20 adults and utilized voxel-based morphometry (VBM to identify specific regions linked to FA. Greater FA predicted greater whole brain white matter volume, and a trend in the same direction was noted for whole brain gray matter volume. Greater FA was associated with significantly greater gray and white matter volumes in discrete brain regions, most prominently in the frontal lobes and in the right cerebral hemisphere. Developmental studies are needed to identify when FA-related brain differences emerge and to elucidate the specific neurobiological mechanisms leading to these differences.

  11. Substantial interobserver variation of thyroid volume and function by visual evaluation of thyroid (99m)Tc scintigraphy

    DEFF Research Database (Denmark)

    Soelberg, Kerstin; Grupe, Peter; Boel-Jørgensen, Henrik

    2014-01-01

    (99m)Tc-pertechnetate scintigraphy is much used in the evaluation of patients with nodular goitre. We investigated the ability of experienced observers to estimate the thyroid 24-h (131)I uptake (RAIU) and the thyroid volume by visual evaluation of the scintigram.......(99m)Tc-pertechnetate scintigraphy is much used in the evaluation of patients with nodular goitre. We investigated the ability of experienced observers to estimate the thyroid 24-h (131)I uptake (RAIU) and the thyroid volume by visual evaluation of the scintigram....

  12. Variation of treatment planning parameters (D90 HR-CTV, D 2cc for OAR) for cervical cancer tandem ring brachytherapy in a multicentre setting: comparison of standard planning and 3D image guided optimisation based on a joint protocol for dose-volume constraints.

    Science.gov (United States)

    Jürgenliemk-Schulz, Ina M; Lang, Stefan; Tanderup, Kari; de Leeuw, Astrid; Kirisits, Christian; Lindegaard, Jacob; Petric, Primoz; Hudej, Robert; Pötter, Richard

    2010-03-01

    To perform a qualitative and quantitative comparison of different treatment planning methods used in different centres for MRI-based brachytherapy (BT) of cervical cancer. Two representative patients with advanced cervical cancer (1 "limited volume case"; 1 "extensive volume case") were planned for brachytherapy (BT) with a tandem-ring applicator by six different centres. During a workshop all centres produced an institutional standard plan and an MRI-based adaptive treatment plan for each case. Optimisation was based on the fractionation schedule (HDR, PDR) and method according to the institutional protocol. The loading pattern, dwell times, shape of the point A isodose varied considerably between institutional standard plans, as did dose-volume parameters for high risk CTV (HR-CTV) and also for the D(2cc) for OAR, violating the dose-volume constraints in many situations. During optimisation, the centres stayed as close as possible to the standard loading pattern and dwell times. The dose distributions and dose-volume parameters between the plans from the different centres became much more comparable after optimisation. The prescribed dose to the HR-CTV could be achieved in the limited volume case by all centres, in the extensive case only if additional needles were applied. Treatment planning for gynaecologic brachytherapy based on different traditions shows less variation in regard to target coverage and OAR dose, when 3D image-based optimisation is performed with a uniform prescription protocol. (c) 2009 Elsevier Ireland Ltd. All rights reserved.

  13. Variations in Rectal Volumes and Dosimetry Values Including NTCP due to Interfractional Variability When Administering 2D-Based IG-IMRT for Prostate Cancer

    Directory of Open Access Journals (Sweden)

    Takashi Hanada

    2014-01-01

    Full Text Available We estimated variations in rectal volumes and dosimetry values including NTCP with interfractional motion during prostate IG-IMRT. Rectal volumes, DVH parameters, and NTCPs of 20 patients were analyzed. For this patient population, the median (range volume on the initial plan for the rectum was 45.6 cc (31.3–82.0, showing on-treatment spread around the initial prediction based on the initial plan. DVH parameters of on-treatment CBCT analyses showed systematic regularity shift from the prediction based on the initial plan. Using the Lyman-Kutcher-Burman model, NTCPs of predicted late rectal bleeding toxicity of rectal grade ≥ 2 (RTOG and the QUANTEC update rectal toxicity for the prediction based on the initial plan were 0.09% (0.02–0.24 and 0.02% (0.00–0.07, respectively, with NTCPs from on-treatment CBCT analyses being 0.35% (0.01–6.16 and 0.12% (0.00–4.11, respectively. Using the relative seriality model, for grade ≥ 2 bleeding rectal toxicity, NTCP of the prediction based on the initial plan was 0.64% (0.15–1.22 versus 1.48% (0.18–7.66 for on-treatment CBCT analysis. Interfraction variations in rectal volumes occur in all patients due to physiological changes. Thus, rectal assessment during 2D-based IG-IMRT using NTCP models has the potential to provide useful and practical dosimetric verification.

  14. Modeling of Shape Memory Alloys: Phase Transformation/Plasticity Interaction at the Nano Scale and the Statistics of Variation in Pseudoelastic Performance

    Science.gov (United States)

    Paranjape, Harshad Madhukar

    Shape memory alloys (SMA) show two remarkable properties- pseudoelasticity and shape memory effect. These properties make them an attractive material for a variety of commercial applications. However, the mechanism of austenite to martensite phase transformation, responsible for these properties also induces plastic deformation leading to structural and functional fatigue. Micron scale experiments suggest that the plastic deformation is induced in part due to the local stress field of the fine martensite microstructure. However, the results are qualitative and the nature of transformation-plasticity interaction is dependent on factors like the width of the interfaces. This thesis presents a new modeling approach to study the interaction between martensite correspondence variant scale microstructure and plastic deformation in austenite. A phase field method based evolution law is developed for phase transformation and reorientation of martensite CVs. This is coupled with a crystal plasticity law for austenite plastic deformation. The model is formulated with finite deformation and rotations. The effect of local crystal orientation is incorporated. An explicit time integration scheme is developed and implemented in a finite element method (FEM) based framework, allowing the modeling of complex boundary conditions and arbitrary loading conditions. Two systematic studies are carried out with the model. First, the interaction between plasticity and phase transformation is studied for load-free and load-biased thermal cycling of single crystals. Key outcomes of this study are that, the residual martensite formed during thermal cycling provides nucleation sites for the phase transformation in the subsequent cycles. Further, the distribution of slip on different slip systems is determined by the martensite texture. This is a strong evidence for transformation induced plasticity. In the second study, experimentally informed simulations of NiTi micropillar compression are

  15. Pre-invasion history and demography shape the genetic variation in the insecticide resistance-related acetylcholinesterase 2 gene in the invasive Colorado potato beetle

    Directory of Open Access Journals (Sweden)

    Piiroinen Saija

    2013-01-01

    Full Text Available Abstract Background Invasive pest species offers a unique opportunity to study the effects of genetic architecture, demography and selection on patterns of genetic variability. Invasive Colorado potato beetle (Leptinotarsa decemlineata populations have experienced a rapid range expansion and intense selection by insecticides. By comparing native and invasive beetle populations, we studied the origins of organophosphate (OP resistance-associated mutations in the acetylcholinesterase 2 (AChE2 gene, and the role of selection and demography on its genetic variability. Results Analysis of three Mexican, two US and five European populations yielded a total of 49 haplotypes. Contrary to the expectations all genetic variability was associated with a point mutation linked to insecticide resistance (S291G, this mutation was found in 100% of Mexican, 95% of US and 71% of European beetle sequences analysed. Only two susceptible haplotypes, genetically very differentiated, were found, one in US and one in Europe. The genetic variability at the AChE2 gene was compared with two other genes not directly affected by insecticide selection, diapause protein 1 and juvenile hormone esterase. All three genes showed reduction in genetic variability indicative of a population bottleneck associated with the invasion. Conclusions Stochastic effects during invasion explain most of the observed patterns of genetic variability at the three genes investigated. The high frequency of the S291G mutation in the AChE2 gene among native populations suggests this mutation is the ancestral state and thus, either a pre-adaptation of the beetle for OP resistance or the AChE2 is not the major gene conferring OP resistance. The long historical association with host plant alkaloids together with recombination may have contributed to the high genetic variation at this locus. The genetic diversity in the AChE2 locus of the European beetles, in turn, strongly reflects founder effects

  16. Intersecting culture, values and transformation in shaping an integrated ethnic identity within a diastratically variated society: Employing South Africa as a case study

    Directory of Open Access Journals (Sweden)

    Jennifer Slater

    2016-03-01

    Full Text Available This article intersects various human diversities through the lens of Christian beliefs and practices as presented in Galatians 3:28. It sets out to identify some of the diastratic diverse factors that influence and shape the distinct socio-economic and cultural environments of the South African arrangement. The amalgam of Christian beliefs, together with cross-cultural practices and philosophical configurations, constitutes a wide range of worldviews that counter the formation of national unity and identity. By examining issues such as diversity and specifically diastratic diversity, as well as inclusiveness as the elixir to bring about national unity, it offers ways of embracing egalitarian ethics to bring about an integrated national identity. This article focuses attention on how value-transformation can be instrumental in the formation of national identity. As the demographics in South Africa are still dualistically designed, boundaries such as male and female, black or white, rich and poor, local or foreign, indigenous and alien, the study takes cognisance of these differences so as to bring all people into the equation of being human by accommodating multiple shades of skin colours, gender, social, cultural and ethnic variations into a diastratic unity. The article draws on how the composition of the Jesus Movement and early Christians, when St Paul, specifically in Galatians 3:28 dealt with diastratic diversity while establishing a Christian identity in antiquity.Intradisciplinary and/or interdisciplinary implications: The approach to the article is multidisciplinary in the sense that it puts the contextual socio-economic and cultural South African problem of diastratic diversity under the searchlight of biblical, theological, ethical, sociological and constitutional specialities. It scrutinises the contemporary societal disorder of antagonism in the light of the early Christian values of inclusiveness and respect for human dignity so as

  17. Pre-invasion history and demography shape the genetic variation in the insecticide resistance-related acetylcholinesterase 2 gene in the invasive Colorado potato beetle.

    Science.gov (United States)

    Piiroinen, Saija; Lindström, Leena; Lyytinen, Anne; Mappes, Johanna; Chen, Yolanda H; Izzo, Victor; Grapputo, Alessandro

    2013-01-18

    Invasive pest species offers a unique opportunity to study the effects of genetic architecture, demography and selection on patterns of genetic variability. Invasive Colorado potato beetle (Leptinotarsa decemlineata) populations have experienced a rapid range expansion and intense selection by insecticides. By comparing native and invasive beetle populations, we studied the origins of organophosphate (OP) resistance-associated mutations in the acetylcholinesterase 2 (AChE2) gene, and the role of selection and demography on its genetic variability. Analysis of three Mexican, two US and five European populations yielded a total of 49 haplotypes. Contrary to the expectations all genetic variability was associated with a point mutation linked to insecticide resistance (S291G), this mutation was found in 100% of Mexican, 95% of US and 71% of European beetle sequences analysed. Only two susceptible haplotypes, genetically very differentiated, were found, one in US and one in Europe. The genetic variability at the AChE2 gene was compared with two other genes not directly affected by insecticide selection, diapause protein 1 and juvenile hormone esterase. All three genes showed reduction in genetic variability indicative of a population bottleneck associated with the invasion. Stochastic effects during invasion explain most of the observed patterns of genetic variability at the three genes investigated. The high frequency of the S291G mutation in the AChE2 gene among native populations suggests this mutation is the ancestral state and thus, either a pre-adaptation of the beetle for OP resistance or the AChE2 is not the major gene conferring OP resistance. The long historical association with host plant alkaloids together with recombination may have contributed to the high genetic variation at this locus. The genetic diversity in the AChE2 locus of the European beetles, in turn, strongly reflects founder effects followed by rapid invasion. Our results suggest that despite

  18. X Chromosome inactivation pattern is not associated with interindividual variations in thyroid volume: a study of euthyroid danish female twins

    DEFF Research Database (Denmark)

    Brix, Thomas Heiberg; Hansen, Pia Skov; Bennedbak, Finn Noe

    2009-01-01

    Ahigher frequency of skewed X chromosome inactivation (XCI) is found in patients with autoimmune thyroid disease (AITD) than in controls. Although goitre is often present in AITD, a recent study failed to show an association between XCI and clinically overt nontoxic goitre. However, the etiology...... a statistically significant association between XCI and thyroid volume: Regression coefficient (beta) = 0.023 (95% confidence interval, -0.062-0.108), p = 0.592 and beta = 0.038 (-0.080-0.156), p = 0.521, respectively. Controlling for potential confounders such as zygosity, age, TSH, smoking habits and use...... of oral contraceptives did not change the findings. In conclusion, in a sample of euthyroid Danish female twins, we found no evidence of a relationship between XCI pattern and thyroid volume....

  19. Detail-replicating shape stretching

    OpenAIRE

    Alhashim, Ibraheem Abbas

    2011-01-01

    Mesh deformation methods are useful for creating shape variations. Existing deformation techniques work on preserving surface details under bending and twisting operations. Stretching different parts of a shape is also a useful operation for generating shape variations. Under stretching, texture-like geometric details should not be preserved but rather replicated. We propose a simple method that help create model variation by applying non-uniform stretching on 3D models. The method replicates...

  20. Variation in Number of Doses, Bottle Volume, and Calculated Yearly Cost of Generic and Branded Latanoprost for Glaucoma.

    Science.gov (United States)

    Queen, Joanna H; Feldman, Robert M; Lee, David A

    2016-03-01

    To evaluate discrepancies in doses per bottle, bottle fill volume, and cost among branded and generic formulations of latanoprost. Comparative economic analysis. This study was conducted at the Ruiz Department of Ophthalmology and Visual Science at The University of Texas Health Science Center at Houston (UTHealth). Four regionally available latanoprost formulations were measured. Number of drops per bottle and actual bottle fill volume were measured for a calculated sample size (10 bottles). Annual cost (using average wholesale price), days use per bottle, drops per milliliter, and number of bottles used per year were calculated. Data were summarized using mean and standard deviation; 1-way analysis of variance and post hoc Tukey's studentized range test were used for comparing means among manufacturers. Pfizer's branded lantanoprost, Xalatan (New York, New York, USA), had the largest fill volume (P Levene 0.14). Annual cost and number of doses per bottle, factors important to patients, vary significantly depending on the manufacturer of latanoprost. Practitioners can better advise patients by being aware of these differences. Copyright © 2016 Elsevier Inc. All rights reserved.

  1. Nano-liter droplet libraries from a pipette: step emulsificator that stabilizes droplet volume against variation in flow rate.

    Science.gov (United States)

    Dutka, Filip; Opalski, Adam S; Garstecki, Piotr

    2016-05-24

    Many modern analytical assays, for example, droplet digital PCR, or screening of the properties of single cells or single mutated genes require splitting a liquid sample into a number of small (typically ca. nano-liter in volume) independent compartments or droplets. This calls for a method that would allow splitting small (microliter) samples of liquid into libraries of nano-liter droplets without any dead volume or waste. Step emulsification allows for facile protocols that require delivery of only the sample liquid, yet they typically exhibit dependence of the droplet size on the rate at which the sample is injected. Here, we report a novel microfluidic junction that reduces the dependence of the volume of droplets on the rate of injection. We also demonstrate generation of tightly monodisperse nanoliter droplets by introduction of solely the dispersed phase into the system from an automatic pipette. The method presented here can readily be used and can replace the sophisticated devices typically used to generate libraries of nano-liter droplets from liquid samples.

  2. Interfractional variation in bladder volume and its impact on cervical cancer radiotherapy: Clinical significance of portable bladder scanner.

    Science.gov (United States)

    Luo, Huanli; Jin, Fu; Yang, Dingyi; Wang, Ying; Li, Chao; Guo, Mingfang; Ran, Xueqi; Liu, Xianfeng; Zhou, Qi; Wu, Yongzhong

    2016-07-01

    A constant bladder volume (BV) is essential to direct the radiotherapy (RT) of pelvic tumors with precision. The purpose of this study was to investigate changes in BV and their impact on cervical cancer RT and to assess the clinical significance of a portable bladder scanner (BS) in achieving a constant BV. A standard bladder phantom (133 ml) and measurements of actual urine volume were both used as benchmarks to evaluate the accuracy of the BS. Comparisons of BS with computed tomography (CT), cone-beam CT (CBCT), and an ultrasound diagnostic device (iU22) were made. Twenty-two consecutive patients with cervical cancer treated with external beam radical RT were divided into an experimental group (13 patients) and a control group (9 patients). In the experimental group, the BV was measured multiple times by BS pre-RT until it was consistent with that found by planning CT. Then a CBCT was performed. The BV was measured again immediately post-RT, after which the patient's urine was collected and recorded. In the control group, CBCT only was performed pre-RT. Interfractional changes in BV and their impact on cervical cancer RT were investigated in both groups. The time of bladder filling was also recorded and analyzed. In measuring the volume of the standard bladder phantom, the BS deviated by 1.4% in accuracy. The difference between the measurements of the BS and the iU22 had no statistical significance (linear correlation coefficient 0.96, P affected the target position in the superior-inferior (SI) direction but had little or no effect in the anterior-posterior and right-left directions. Based on the collected data, the target displacement in the SI direction was reduced from 2.0 to 0.4 mm, while the CTV-to-PTV (CTV: clinical target volume; PTV: planning target volume) margin in the SI direction was reduced from 11.1 to 6.4 mm. The BV increased by 3.7 ± 1.0 ml/min (range, 1.7-4.7 ml/min), which depended on the amount of water ingested by the patient (R = 0.96, P

  3. Reinforced Airfoil Shaped Body

    DEFF Research Database (Denmark)

    2011-01-01

    The present invention relates to an airfoil shaped body with a leading edge and a trailing edge extending along the longitudinal extension of the body and defining a profile chord, the airfoil shaped body comprising an airfoil shaped facing that forms the outer surface of the airfoil shaped body...... and surrounds an internal volume of the body, a distance member that is connected to the facing inside the body and extends from the facing and into the internal volume of the body, and at least one reinforcing member that operates in tension for reinforcing the facing against inward deflections...... and that is connected to the facing inside the internal volume of the body at the same side of the profile chord as the connection of the distance member to the facing and to the distance member at a distance from the facing....

  4. Impact of electromechanical parameter variations in treatment volume doses and adjacent structures; Impacto da variacao dos parametros eletro-mecanicos nas doses do volume de tratamento e nas estruturas adjacentes

    Energy Technology Data Exchange (ETDEWEB)

    Morais, M.E.; Campos, A.M. [Instituto Nacional do Cancer (INCa), Rio de Janeiro, RJ (Brazil). Programa de Qualidade em Radioterapia]. E-mails: memorais@yahoo.com.br; amcampos@inca.gov.br; Goncalves, J. F. [Instituto de Oncologia e Radioterapia GV, Governador Valadares, MG (Brazil)]. E-mail: joelfgoncalves@yahoo.com.br; Ferreira, M.L. [Centro Radioterapico Gavea, Rio de Janeiro, RJ (Brazil)]. E-mail: mluciaf@yahoo.com

    2003-07-01

    ICRU Report 62 recommends that radiotherapy treatment dose should be prescribed in such a way that the dose to the target volume varies no more than 10%. In order to keep this goal, a very important role is played by the quality assurance (QA) of the treatment unit associated to the high level work of the personnel involved in planning and patient treatment. This paper shows the influence of the main electrical and mechanical linear accelerator parameters: field size, source-skin distance, gantry angle and light x radiation field coincidence in tumor volume and adjacent organ doses. We simulated a cubic tumor and a cubic adjacent critical organ in a cubic phantom and used a 3D Prowess system for planning. The treatment has been simulated for a 6 MV linear accelerator. We simulated two treatment planning: one using all the parameters inside their tolerance limits and another doubling these limits. The final results have show that, if the irradiation machine operates out of the tolerance limits, the dose variation in the planning target volume (PTV) can goes till {+-} 5,8% and in the critical adjacent organ till {+-} 7,7%. Therefore we concluded that, according to the complexity of the treatment, it can be necessary to reduce the tolerance levels advised by the IAEA/TECDOC - 1151. (author)

  5. A study on the variation of maxillary sinus volume and projection angle in children for CT scan

    Energy Technology Data Exchange (ETDEWEB)

    Ji, Youn Sang; Dong, Kyung Rae; Choi, Seong Kwan; Kim, Mi Hyun [Radiological Technology, Gwangju Health University, Gwangju (Korea, Republic of); Jung, Myung Jin [Dept. of Radiation Science and Technology, Graduate School of Chonbuk National University, Jeonju (Korea, Republic of); Yeo, Hwa Yeon [Dept. of Radiology, Nambu University, Gwangju (Korea, Republic of)

    2017-06-15

    The Water's view is that you can examine and diagnose disease of the maxillary sinus and implemented a simple and economical because a lot of tests. Because changes in the size of the maxillary sinus and skull growth in volume, depending on the disease that occurs in children often differ from the baseline angle of the water's view that it is easy to observe. Through Computed tomography (CT) and volumetric analysis and Orbitmeatal line (OML) and Image plate (IP) is the angle and evaluate the appropriate Water's view angle in children.

  6. Variation in the Gross Tumor Volume and Clinical Target Volume for Preoperative Radiotherapy of Primary Large High-Grade Soft Tissue Sarcoma of the Extremity Among RTOG Sarcoma Radiation Oncologists

    Energy Technology Data Exchange (ETDEWEB)

    Wang Dian, E-mail: dwang@mcw.edu [Medical College of Wisconsin, Milwaukee, WI (United States); Bosch, Walter [Washington University, St. Louis, MO (United States); Kirsch, David G. [Duke University, Durham, NC (United States); Al Lozi, Rawan; El Naqa, Issam [Washington University, St. Louis, MO (United States); Roberge, David [McGill University Health Centre, Montreal (Canada); Finkelstein, Steven E. [Moffitt Cancer Center, Tampa, FL (United States); Petersen, Ivy; Haddock, Michael [Mayo Clinic, Rochester, MN (United States); Chen, Yen-Lin E. [Massachusetts General Hospital, Boston, MA (United States); Saito, Naoyuki G. [Roswell Park Cancer Institute, Buffalo, NY (United States); Hitchcock, Ying J. [University of Utah, Salt Lake City, UT (United States); Wolfson, Aaron H. [University of Miami Miller School of Medicine, Miami, FL (United States); DeLaney, Thomas F. [Massachusetts General Hospital, Boston, MA (United States)

    2011-12-01

    Purpose: To evaluate variability in the definition of preoperative radiotherapy gross tumor volume (GTV) and clinical target volume (CTV) delineated by sarcoma radiation oncologists. Methods and Materials: Extremity sarcoma planning CT images along with the corresponding diagnostic MRI from two patients were distributed to 10 Radiation Therapy Oncology Group sarcoma radiation oncologists with instructions to define GTV and CTV using standardized guidelines. The CT data with contours were then returned for central analysis. Contours representing statistically corrected 95% (V95) and 100% (V100) agreement were computed for each structure. Results: For the GTV, the minimum, maximum, mean (SD) volumes (mL) were 674, 798, 752 {+-} 35 for the lower extremity case and 383, 543, 447 {+-} 46 for the upper extremity case. The volume (cc) of the union, V95 and V100 were 882, 761, and 752 for the lower, and 587, 461, and 455 for the upper extremity, respectively. The overall GTV agreement was judged to be almost perfect in both lower and upper extremity cases (kappa = 0.9 [p < 0.0001] and kappa = 0.86 [p < 0.0001]). For the CTV, the minimum, maximum, mean (SD) volumes (mL) were 1145, 1911, 1605 {+-} 211 for the lower extremity case and 637, 1246, 1006 {+-} 180 for the upper extremity case. The volume (cc) of the union, V95, and V100 were 2094, 1609, and 1593 for the lower, and 1533, 1020, and 965 for the upper extremity cases, respectively. The overall CTV agreement was judged to be almost perfect in the lower extremity case (kappa = 0.85 [p < 0.0001]) but only substantial in the upper extremity case (kappa = 0.77 [p < 0.0001]). Conclusions: Almost perfect agreement existed in the GTV of these two representative cases. Tshere was no significant disagreement in the CTV of the lower extremity, but variation in the CTV of upper extremity was seen, perhaps related to the positional differences between the planning CT and the diagnostic MRI.

  7. Seasonal and spatial distribution of Bacterioplankton in a fluvial-lagunar system of a tropical region: density, biomass, cellular volume and morphologic variation

    Directory of Open Access Journals (Sweden)

    Magnólia Fernandes Florêncio de Araújo

    2008-02-01

    Full Text Available The temporal and spatial fluctuations of Bacterioplankton in a fluvial-lagunar system of a tropical region (Pitimbu River and Jiqui Lake, RN were studied during the dry and the rainy periods. The bacterial abundance varied from 2.67 to 5.1 Cells10(7mL-1 and did not show a typical temporal variation, presenting only small oscillations between the rainy and the dry periods. The bacterial biomass varied from 123 µgC L-1 to 269 µgC L-1 in the sampling sites and the average cellular volume varied from 0.12 to 0.54µm³, showing a predominance of the rods. The temperature showed a positive correlation with the cellular volume of the rods (R=0.55; p=0.02 and vibrio (R=0.53; p=0.03. Significant spatial differences of biomass (Mann Whitney: p=0.01 and cellular volume of the morphotypes (Mann Whitney: p=0.003 were found between the sampling sites. The strong positive correlations of the water temperature and oxygen with bacterioplankton showed a probable high bacterial activity in this system.A variação temporal e espacial do bacterioplâncton em um sistema fluvial-lagunar de região tropical foi estudada em períodos seco e chuvoso. As médias da abundância bacteriana variaram de 2,67 a 5,1 x 10(7 e não exibiram uma variação temporal marcante, tendo apresentado apenas pequenas oscilações entre os períodos chuvoso e seco. A biomassa bacteriana variou de 123 µg C L-1 a 269 µg C L-1 entre os locais de coleta e o volume celular médio de 0,12µm³ a 0,54µm³, ocorrendo predominância de bacilos. A temperatura mostrou correlação positiva com o volume celular de bacilos (R=0,55; p=0,02 e de vibriões (R=0,53; p=0,03. Foram encontradas diferenças espaciais significativas de biomassa (Mann Whitney: p=0,01 e volume celular dos morfotipos (Mann Whitney: p= 0,003, entre os locais de coleta. As fortes correlações positivas da temperatura da água e do oxigênio, com o bacterioplâncton, são sugestivas de uma provavelmente elevada atividade

  8. Factors of tidal volume variation during augmented spontaneous ventilation in patients on extracorporeal carbon dioxide removal. A multivariate analysis.

    Science.gov (United States)

    Bein, T; Müller, T; Graf, B M; Philipp, A; Zeman, F; Schultz, M J; Slutsky, A S; Weber-Carstens, S

    2015-01-01

    Extracorporeal carbon dioxide removal (ECCO2-R) allows lung protective ventilation using lower tidal volumes (VT) in patients with acute respiratory failure. The dynamics of spontaneous ventilation under ECCO2-R has not been described previously. This retrospective multivariable analysis examines VT patterns and investigates the factors that influence VT, in particular sweep gas flow and blood flow through the artificial membrane. We assessed VT, respiratory rate (RR), minute ventilation (MV), and levels of pressure support (0-24 cm H2O), sweep gas flow (0-14 L/min) and blood flow through the membrane (0.8-1.8 L/min) in 40 patients from the moment they were allowed to breathe spontaneously. Modest hypercapnia was accepted. Patients tolerated moderate hypercapnia well. In a generalized linear model the increase in sweep gas flow (Pventilation. Such a technique can be used for prolonged lung protective ventilation even in the patient's recovery period.

  9. The role of predation in variation in body shape in guppies Poecilia reticulata: a comparison of field and common garden phenotypes.

    Science.gov (United States)

    Burns, J G; Di Nardo, P; Rodd, F H

    2009-10-01

    The body shapes of both wild-caught and laboratory-reared male and female Trinidadian guppies Poecilia reticulata from two low-predation and two high-predation populations were studied, but predation regime did not seem to be the most important factor affecting body shape. Instead, complicated patterns of plasticity in body shape among populations and the sexes were found. In particular, populations differed in the depth of the caudal peduncle, which is the muscular region just anterior to the tail fin rays and from which most swimming power is generated. Strikingly, the direction of population differences in caudal peduncle depth observed in wild-caught individuals was reversed when P. reticulata were raised in a common laboratory environment.

  10. Bioremediation of Spent Bleaching Earth (SBE Wastes using Lipolitic Bacteria (Bacillus cereus with Variation of Inoculum Volume

    Directory of Open Access Journals (Sweden)

    Maria Lusia

    2018-01-01

    Full Text Available Spent bleaching earth (SBE is a solid waste was generated from the CPO refining step into cooking oil.  SBE that was discharged directly into the environment has the potential to pollute the environment, because in the SBE waste contained oil and acid residues, which are easily to be oxidized and flammable.  Therefore, SBE must be processed first before being discharged into the environment.  One way to manage SBE is by bioremediation.  Bioremediation is a method on cleaning the environment from contaminants by using  biological agents, such as bacteria, fungi etc.  The bacterial isolates used in this study were Bacillus cereus.  This study aims to obtain the best inoculum and to know the ability of Bacillus cereus bacteria in degrading the oil content in SBE waste. This study used Completely Randomized Design with the volume of Bacillus cereus bacteria inoculum as a treatment, consisting of 6 treatment levels of 0 mL kg-1, 25 mL kg-1, 50 mL kg-1, 75 mL kg-1, 100 mL kg-1, 125 mL kg-1.  Each treatment level was repeated 3 times, so taht 18 experimental units were obtained.  Observation was done once a week, in a month.  Parameters observed were bacterial population, percentage of oil degradation, and oil content degradation.  The best treatment result for the bacterial population was obtained at the treatment of 100 mL kg-1, at week 4 which was 7,4 x 108 cfu g-1, and for the oil degradation was obtained at 50 mL kg-1 on the treatment at week 4 as big as 90,43%.

  11. Restoration of muscle volume and shape induced by electrical stimulation of denervated degenerated muscles: qualitative and quantitative measurement of changes in rectus femoris using computer tomography and image segmentation.

    Science.gov (United States)

    Gargiulo, Paolo; Vatnsdal, Brynjar; Ingvarsson, Páll; Knútsdóttir, Sigrún; Gudmundsdóttir, Vilborg; Yngvason, Stefán; Helgason, Thórdur

    2008-08-01

    This study demonstrates in a novel way how volume and shape are restored to denervated degenerated muscles due to a special pattern of electrical stimulation. To this purpose, Spiral Computer Tomography (CT) and special image processing tools were used to develop a method to isolate the rectus femoris from other muscle bellies in the thigh and monitor growth and morphology changes very accurately. During 4 years of electrical stimulation, three-dimensional (3D) reconstructions of the rectus femoris muscles from patients with long-term flaccid paraplegia were made at different points in time. The growth of the muscle and its changes through the time period are seen in the 3D representation and are measured quantitatively. Furthermore, changes in shape are compared with respect to healthy muscles in order to estimate the degree of restoration. The results clearly show a slow but continuing muscle growth induced by electrical stimulation; the increase of volume is accompanied by the return of a quasi-normal muscle shape. This technique allows a unique way of monitoring which provides qualitative and quantitative information on the denervated degenerated muscle behavior otherwise hidden.

  12. Irradiation of hepatocellular carcinoma: Impact of breathing on motions and variations of volume of the tumor, liver and upper abdominal organs; L'irradiation des carcinomes hepatocellulaires: impact de la respiration sur les mouvements et variations de volume de la tumeur, du foie et des organes intra-abdominaux

    Energy Technology Data Exchange (ETDEWEB)

    Kubas, A.; Mornex, F.; D' Hombres, A.; Lorchel, F.; Chapet, O. [Centre hospitalier Lyon-Sud, Service de Radiotherapie-oncologie Rhone-Alpes, 69 - Pierre-Benite (France); Merle, P. [Hopital de l' Hotel-Dieu, Service d' Hepatogastroenterologie, 69 - Lyon (France)

    2008-12-15

    Purpose: To evaluate the amplitude of motion and the variations of volume of the tumor, the liver and upper abdominal organs induced by breathing during the irradiation of hepatocellular carcinoma (H.C.C.). Material and methods: Two scanners were performed in inhale and in exhale not forced in 20 patients with a H.C.C.. The liver (left/right lobes), the tumor, the duodenum, the two kidneys and the pancreas were delineated on each acquisition. The superposition of the two spirals made it possible to measure the displacements and variations of volume of these structures in the cranio caudal (C.C.), lateral (Lat), and anteroposterior (A.P.) directions. Results:The mean displacement of the tumour in C.C., Lat and A.P. was of 19.7 {+-} 8.3 mm, 4.5 {+-} 2.3 mm, and 8.9 {+-} 6.5 mm. The greatest amplitude of movement was obtained in C.C. for the right and left hepatic lobes (19 {+-} 6.5 mm, 10 {+-} 5.6 mm), the duodenum(12.6 {+-} 6.4 mm), the kidneys right and left (15.5 {+-} 6.1 mm, 16.2 {+-} 10 mm) and the pancreas (13.2 {+-} 6 mm). No significant variation of volume was observed for these organs. Conclusion: The movements of the tumour, the liver and the abdominal organs, induced by breathing are significant. The respiratory gating appears essential in particular with the development of new techniques of irradiation such as the intensity-modulated radiotherapy (I.M.R.T.) or the stereotactic body radiation therapy (S.B.R.T.). (authors)

  13. Magma Chamber Model of Batur Caldera, Bali, Indonesia: Compositional Variation of Two Facies, Large-Volume Dacitic Ignimbrites

    Directory of Open Access Journals (Sweden)

    Igan S. Sutawidjaja

    2015-05-01

    Full Text Available DOI:10.17014/ijog.2.2.111-124Batur is one of the finest known calderas on Earth, and is the source of at least two major ignimbrite eruptions with a combined volume of some 84 km3 and 19 km3. These ignimbrites have a similar compositions, raising the question of whether they are geneticaly related. The Batur Ignimbrite-1 (BI-1 is crystal poor, containing rhyodacitic (68 - 70wt % SiO2, white to grey pumices and partly welded and unwelded. The overlying Batur Ignimbrite-2 (BI-2 is a homogeneous grey to black dacitic pumices (64 - 66 wt % SiO2, unwelded and densely welded (40 - 60% vesicularity, crystal and lithic rich. Phase equilibria indicate that the Batur magma equilibrated at temperatures of 1100 - 1300oC with melt water contents of 3 - 6 wt%. The post-eruptive Batur magma was cooler (<1100oC and it is melt more water rich (> 6 wt % H2O. A pressure of 20 kbar is infered from mineral barometry for the Batur magma chamber. Magmatic chamber model is one in which crystals and melt separate from a convecting Batur magma by density differences, resulting in a stratified magma chamber with a homogeneous central zone, a crystal-rich accumulation zone near the walls or base, and a buoyant, melt-rich zone near the top. This is consistent with the estimated magma temperatures and densities: the pre-eruptive BI-1 magma was hoter (1300oC and more volatile rich (6 wt % H2O with density 2.25 g/cm3 than the BI-2 magma (1200oC; 4 wt % H2O in density was higher (2.50 g/cm3. Batur melt characteristics and intensive parameters are consistent with a volatile oversaturation-driven eruption. However, the higher H2O content, high viscosity and low crystal content of the BI-1 magma imply an external eruption trigger.

  14. Droplet polydispersity and shape fluctuations in AOT [bis(2-ethylhexyl)sulfosuccinate sodium salt] microemulsions studied by contrast variation small-angle neutron scattering

    DEFF Research Database (Denmark)

    Arleth, L.; Pedersen, J.S.

    2001-01-01

    Microemulsions consisting of AOT water, and decane or iso-octane are studied in the region of the phase diagram where surfactant covered water droplets are formed. The polydispersity and shape fluctuations of the microemulsion droplets are determined and compared in the two different alkane types....... A polydispersity index (sigma /R Of the Gaussian size distribution) of 16% and an average axis ratio of the droplets of 1.56 is found in the AOT/D2O/decane microemulsion. In the AOT/D2O/iso-octane system the polydispersity index is also 16% while the axis ratio is 1.72. The bending elastic constant kappa...

  15. Contração volumétrica e forma dos frutos de mamona durante a secagem = Shape and shrinkage of the castor bean fruit during the drying process

    Directory of Open Access Journals (Sweden)

    André Luís Duarte Goneli

    2011-01-01

    Full Text Available O objetivo do presente trabalho foi avaliar o efeito da variação do teor de água na contração volumétrica, dimensões características e forma dos frutos de mamona durante a secagem. Foram utilizados frutos colhidos com teor de água de 2,50 (b.s., secos à temperatura de 40ºC até o teor final de 0,11 (b.s.. O tamanho dos frutos foi determinadopor meio da variação do volume e a forma foi analisada pela esfericidade e circularidade. A contração volumétrica dos frutos foi determinada pela relação entre o volume em cada teor de água e o volume inicial. Com base nos resultados, concluiu-se que a forma dos frutos de mamona é influenciada pela redução do teor de água, promovendo redução da esfericidade e circularidade. As dimensões características (comprimento, largura e espessura e o diâmetrogeométrico médio dos frutos sofrem redução de suas magnitudes com a redução do teor de água. A redução do teor de água influencia a contração volumétrica unitária e da massa dos frutos de mamona, provocando redução de seus valores em 46,0 e 63,0%, respectivamente.O modelo polinomial, dentre aqueles testados, foi o que melhor representou o fenômeno da contração volumétrica da massa e unitária dos frutos de mamona.The objective of this work was to evaluate the effect of moisture content on castor bean fruit shrinkage, dimensional characteristics and shape during drying. Castor bean fruits were harvested with 2.50 (d.b. moisture content and dried at 40°C up to final moisturecontent of 0.11 (d.b.. The size of the fruits was determined according to the shrinkage rate and the shape analyzed through the sphericity and circularity method. Castor fruit shrinkage was determined by the ratio between its volume with respective moisture content and its initial volume. Based on the obtained results, it can be concluded that the shape castor bean fruits is influenced by reduction in moisture content promoting the sphericity and

  16. Goal-Directed Fluid Therapy Using Stroke Volume Variation Does Not Result in Pulmonary Fluid Overload in Thoracic Surgery Requiring One-Lung Ventilation

    Directory of Open Access Journals (Sweden)

    Sebastian Haas

    2012-01-01

    Full Text Available Background. Goal-directed fluid therapy (GDT guided by functional parameters of preload, such as stroke volume variation (SVV, seems to optimize hemodynamics and possibly improves clinical outcome. However, this strategy is believed to be rather fluid aggressive, and, furthermore, during surgery requiring thoracotomy, the ability of SVV to predict volume responsiveness has raised some controversy. So far it is not known whether GDT is associated with pulmonary fluid overload and a deleterious reduction in pulmonary function in thoracic surgery requiring one-lung-ventilation (OLV. Therefore, we assessed the perioperative course of extravascular lung water index (EVLWI and paO2/FiO2-ratio during and after thoracic surgery requiring lateral thoracotomy and OLV to evaluate the hypothesis that fluid therapy guided by SVV results in pulmonary fluid overload. Methods. A total of 27 patients (group T were enrolled in this prospective study with 11 patients undergoing lung surgery (group L and 16 patients undergoing esophagectomy (group E. Goal-directed fluid management was guided by SVV (SVV 0.05 in EVLWI during the observation period (BL: 7.8 ± 2.5, 24postop: 8.1 ± 2.4 mL/kg. A subgroup analysis for group L and group E also did not reveal significant changes of EVLWI. The paO2/FiO2-ratio decreased significantly during the observation period (group L: BL: 462 ± 140, OLVterm15: 338 ± 112 mmHg; group E: BL: 389 ± 101, 24postop: 303 ± 74 mmHg but remained >300 mmHg except during OLV. Conclusions. SVV-guided fluid management in thoracic surgery requiring lateral thoracotomy and one-lung ventilation does not result in pulmonary fluid overload. Although oxygenation was reduced, pulmonary function remained within a clinically acceptable range.

  17. The brain relaxation and cerebral metabolism in stroke volume variation-directed fluid therapy during supratentorial tumors resection: crystalloid solution versus colloid solution.

    Science.gov (United States)

    Xia, Juan; He, Zhiyong; Cao, Xiaoying; Che, Xuehua; Chen, Liang; Zhang, Jun; Liang, Weimin

    2014-10-01

    Compared with goal-directed crystalloid therapy, goal-directed colloid therapy during high-risk surgery may improve postoperative outcome. Whether intraoperative fluid therapy based on goal-directed protocol with different types of fluid has distinctive effects on brain relaxation and cerebral metabolism during craniotomy remains unclear. Forty patients with supratentorial brain tumors undergoing craniotomy were randomly assigned to either a Ringer's Lactate-based goal-directed group (LR group, n=20) or a 6% hydroxyethyl starch-based goal-directed group (HES group, n=20). The goal was achieved by maintaining a target stroke volume variation (SVVcerebral metabolism variables (jugular venous oxygen saturation [SjvO(2)], arterial-jugular venous differences in oxygen [CajvO(2)], glucose [A-JvGD], lactate [A-JvLD], and cerebral extraction ratio for oxygen [CERO(2)]) and fluid volumes. There is no significant difference between the LR and HES groups on brain relaxation scales (P=0.845), or measures of cerebral oxygenation and metabolism. Intragroup comparisons showed that CERO(2) increased by 14.3% (P=0.009, LR group) and 13.2% (P=0.032, HES group), respectively, and SjvO(2) was decreased by 8.8% (P=0.016, LR group) and 8.1% (P=0.026, HES group), respectively, after tumor removal, compared with baseline. During surgery, the LR group (3070±1138 mL) received more fluid than the HES group (2041±758 mL, P=0.002). In patients undergoing supratentorial tumor resection, goal-directed HES therapy was not superior to goal-directed LR therapy for brain relaxation or cerebral metabolism, although less fluid was needed to maintain the target SVV in the HES-based group than in the LR-based group.

  18. Midpoint Shapes.

    Science.gov (United States)

    Welchman, Rosamond; Urso, Josephine

    2000-01-01

    Emphasizes the importance of children exploring hands-on and minds-on mathematics. Presents a midpoint shape activity for students to explore the midpoint shape of familiar quadrilaterals, such as squares and rectangles. (KHR)

  19. Clear-cornea cataract surgery: pupil size and shape changes, along with anterior chamber volume and depth changes. A Scheimpflug imaging study

    OpenAIRE

    Kanellopoulos AJ; Asimellis G

    2014-01-01

    Anastasios John Kanellopoulos,1,2 George Asimellis11Laservision.gr Eye Institute, Athens, Greece; 2New York University School of Medicine, New York, NY, USA Purpose: To investigate, by high-precision digital analysis of data provided by Scheimpflug imaging, changes in pupil size and shape and anterior chamber (AC) parameters following cataract surgery.Patients and methods: The study group (86 eyes, patient age 70.58±10.33 years) was subjected to cataract removal surgery with in-the...

  20. Lung lobe segmentation by graph search with 3D shape constraints

    Science.gov (United States)

    Zhang, Li; Hoffman, Eric A.; Reinhardt, Joseph M.

    2001-05-01

    The lung lobes are natural units for reporting image-based measurements of the respiratory system. Lobar segmentation can also be used in pulmonary image processing to guide registration and drive additional segmentation. We have developed a 3D shape-constrained lobar segmentation technique for volumetric pulmonary CT images. The method consists of a search engine and shape constraints that work together to detect lobar fissures using gray level information and anatomic shape characteristics in two steps: (1) a coarse localization step, (2) a fine tuning step. An error detecting mechanism using shape constraints is used in our method to correct erroneous search results. Our method has been tested in four subjects, and the results are compared to manually traced results. The average RMS difference between the manual results and shape-constrained segmentation results is 2.23 mm. We further validated our method by evaluating the repeatability of lobar volumes measured from repeat scans of the same subject. We compared lobar air and tissue volume variations to show that most of the lobar volume variations are due to difference in air volume scan to scan.

  1. Oncoplastic breast surgery combining periareolar mammoplasty with volume displacement using a crescent-shaped cutaneous flap for early breast cancer in the upper quadrant.

    Science.gov (United States)

    Kijima, Yuko; Yoshinaka, Heiji; Hirata, Munetsugu; Nakajo, Akihiro; Arima, Hideo; Ishigami, Sumiya; Ueno, Shinichi; Natsugoe, Shoji

    2013-08-01

    Oncoplastic breast surgery (OBS), which combines the concepts of oncological and plastic surgery, is becoming more common, especially in Western countries; however, only a few reports have been published in Japan. We herein report the results of OBS for Japanese patients with early breast cancer in the upper quadrant. We performed oncoplastic surgery combining partial mastectomy using a periareolar incision with immediate breast reshaping using a crescent-shaped cutaneous flap in three patients with a past history of breast-feeding, ptotic breasts and lesions that were suitable for breast conserving surgery. The lesions were located in the upper quadrant and were 5, 6 and 10 cm from the nipple, respectively. The total length of the operations ranged between 86 and 192 min, with the mean being 164 min. Two patients underwent contralateral surgery to produce symmetrical breasts and one did not. The plastic period after receiving pathological results intraoperatively ranged between 47 and 120 min, with the mean period being 82 min. The observation period ranged between 6 and 12 months, and the cosmetic results were excellent in all three cases. OBS combining partial mastectomy using a periareolar incision with immediate breast reshaping using a crescent-shaped cutaneous flap was successfully performed in patients with early cancer in the upper quadrant.

  2. Mito-nuclear genetic comparison in a Wolbachia infected weevil: insights on reproductive mode, infection age and evolutionary forces shaping genetic variation

    Science.gov (United States)

    2010-01-01

    Background Maternally inherited endosymbionts like Wolbachia pipientis are in linkage disequilibrium with the mtDNA of their hosts. Therefore, they can induce selective sweeps, decreasing genetic diversity over many generations. This sex ratio distorter, that is involved in the origin of parthenogenesis and other reproductive alterations, infects the parthenogenetic weevil Naupactus cervinus, a serious pest of ornamental and fruit plants. Results Molecular evolution analyses of mitochondrial (COI) and nuclear (ITS1) sequences from 309 individuals of Naupactus cervinus sampled over a broad range of its geographical distribution were carried out. Our results demonstrate lack of recombination in the nuclear fragment, non-random association between nuclear and mitochondrial genomes and the consequent coevolution of both genomes, being an indirect evidence of apomixis. This weevil is infected by a single Wolbachia strain, which could have caused a moderate bottleneck in the invaded population which survived the initial infection. Conclusions Clonal reproduction and Wolbachia infection induce the coevolution of bacterial, mitochondrial and nuclear genomes. The time elapsed since the Wolbachia invasion would have erased the traces of the demographic crash in the mtDNA, being the nuclear genome the only one that retained the signal of the bottleneck. The amount of genetic change accumulated in the mtDNA and the high prevalence of Wolbachia in all populations of N. cervinus agree with the hypothesis of an ancient infection. Wolbachia probably had great influence in shaping the genetic diversity of N. cervinus. However, it would have not caused the extinction of males, since sexual and asexual infected lineages coexisted until recent times. PMID:21050430

  3. Seasonal variation in wing size and shape between geographic populations of the malaria vector, Anopheles coluzzii in Burkina Faso (West Africa).

    Science.gov (United States)

    Hidalgo, Kevin; Dujardin, Jean-Pierre; Mouline, Karine; Dabiré, Roch K; Renault, David; Simard, Frederic

    2015-03-01

    The mosquito, Anopheles coluzzii is a major vector of human malaria in Africa with widespread distribution throughout the continent. The species hence populates a wide range of environments in contrasted ecological settings often exposed to strong seasonal fluctuations. In the dry savannahs of West Africa, this mosquito population dynamics closely follows the pace of surface water availability: the species pullulates during the rainy season and is able to reproduce throughout the dry season in areas where permanent water bodies are available for breeding. The impact of such environmental fluctuation on mosquito development and the phenotypic quality of emerging adults has however not been addressed in details. Here, we examined and compared phenotypic changes in the duration of pre-imaginal development, body dry mass at emergence and wing size, shape and surface area in young adult females An. coluzzii originated from five distinct geographic locations when they are reared in two contrasting conditions mimicking those experienced by mosquitoes during the rainy season (RS) and at the onset of the dry season (ODS) in Burkina Faso (West Africa). Our results demonstrated strong phenotypic plasticity in all traits, with differences in the magnitude and direction of changes between RS and ODS depending upon the geographic origin, hence the genetic background of the mosquito populations. Highest heterogeneity within population was observed in Bama, where large irrigation schemes allow year-round mosquito breeding. Further studies are needed to explore the adaptive value of such phenotypic plasticity and its relevance for local adaptation in An. coluzzii. Copyright © 2015 Elsevier B.V. All rights reserved.

  4. Shape Variation in the Craniomandibular System and Prevalence of Dental Problems in Domestic Rabbits: A Case Study in Evolutionary Veterinary Science

    Directory of Open Access Journals (Sweden)

    Christine Böhmer

    2017-01-01

    Full Text Available In contrast to wild lagomorphs, pet rabbits exhibit a noticeably high frequency of dental problems. Although dietary habits are considered as a major factor contributing to acquired malocclusions, the exact causes and interrelationships are still under debate. In this regard, an important aspect that has not been considered thoroughly to date is the effect of diet-induced phenotypic plasticity in skull morphology. Therefore, we conducted a geometric morphometric analysis on skull radiological images of wild and pet rabbits in order to quantify intraspecific variation in craniomandibular morphology. The statistical analyses reveal a significant morphological differentiation of the craniomandibular system between both groups. Furthermore, the analysis of covariance shows that the force-generating modules (cranium and mandible vary independently from the force-receiving module (hypselodont teeth in pet rabbits, which is in contrast to their wild relatives. Our findings suggest that the phenotypic changes in domestic rabbits impact mastication performance and, consequently, oral health. An adequate close-to-nature nutrition throughout the whole life and especially beginning early parallel to weaning (phase of increased phenotypic plasticity is necessary to ensure a normal strain on the teeth by promoting physiological lateral gliding movements and avoiding direct axial loads.

  5. Shape Variation in the Craniomandibular System and Prevalence of Dental Problems in Domestic Rabbits: A Case Study in Evolutionary Veterinary Science.

    Science.gov (United States)

    Böhmer, Christine; Böhmer, Estella

    2017-01-24

    In contrast to wild lagomorphs, pet rabbits exhibit a noticeably high frequency of dental problems. Although dietary habits are considered as a major factor contributing to acquired malocclusions, the exact causes and interrelationships are still under debate. In this regard, an important aspect that has not been considered thoroughly to date is the effect of diet-induced phenotypic plasticity in skull morphology. Therefore, we conducted a geometric morphometric analysis on skull radiological images of wild and pet rabbits in order to quantify intraspecific variation in craniomandibular morphology. The statistical analyses reveal a significant morphological differentiation of the craniomandibular system between both groups. Furthermore, the analysis of covariance shows that the force-generating modules (cranium and mandible) vary independently from the force-receiving module (hypselodont teeth) in pet rabbits, which is in contrast to their wild relatives. Our findings suggest that the phenotypic changes in domestic rabbits impact mastication performance and, consequently, oral health. An adequate close-to-nature nutrition throughout the whole life and especially beginning early parallel to weaning (phase of increased phenotypic plasticity) is necessary to ensure a normal strain on the teeth by promoting physiological lateral gliding movements and avoiding direct axial loads.

  6. A computational simulation study on the acoustic pressure generated by a dental endosonic file: effects of intensity, file shape and volume.

    Science.gov (United States)

    Tiong, T Joyce; Price, Gareth J; Kanagasingam, Shalini

    2014-09-01

    One of the uses of ultrasound in dentistry is in the field of endodontics (i.e. root canal treatment) in order to enhance cleaning efficiency during the treatment. The acoustic pressures generated by the oscillation of files in narrow channels has been calculated using the COMSOL simulation package. Acoustic pressures in excess of the cavitation threshold can be generated and higher values were found in narrower channels. This parallels experimental observations of sonochemiluminescence. The effect of varying the channel width and length and the dimensions and shape of the file are reported. As well as explaining experimental observations, the work provides a basis for the further development and optimisation of the design of endosonic files. Copyright © 2014 Elsevier B.V. All rights reserved.

  7. Goal-directed fluid restriction using stroke volume variation and cardiac index during one-lung ventilation: a randomized controlled trial.

    Science.gov (United States)

    Xu, Hui; Shu, Shu-Hua; Wang, Di; Chai, Xiao-Qing; Xie, Yan-Hu; Zhou, Wei-De

    2017-09-01

    Goal-directed therapy confers a strong prognosis in patients undergoing major cardiac or noncardiac surgery. The present study investigated whether intraoperative goal-directed fluid restriction (GDFR) using stroke volume variation (SVV) and cardiac index could improve oxygenation and postoperative outcome in patients undergoing one-lung ventilation (OLV). A Total of 168 patients scheduled for elective thoracoscopic lobectomy under OLV were randomized into the GDFR protocol (group G) or conventional fluid therapy groups (group C). Patients in group C underwent conventional fluid therapy based on mean arterial pressure (MAP), central venous pressure (CVP), and urine volume, whereas those in group G received GDFR protocol associated with the SVV from 10-13% and the cardiac index was controlled at a minimum of 2.5 L/min/m2. The primary outcome variable was PaO2/FiO2. The secondary outcomes were other pulmonary variables and lung mechanics, inflammatory response, the incidence of postoperative pulmonary complications, and the length of hospital stay. During surgery, the PaO2/FiO2 ratio in group G was more than that of group C at 30 and 60 min after OLV, 10 min after re-expansion, and the end of the operation (259±29 vs. 314±34; 253±30 vs. 308±35; 341±34 vs. 394±39; 349±35 vs. 401±39, respectively, all Pmechanics with the initiation of OLV. The incidence of postoperative pulmonary complications such as acute lung injury and pneumonia, and the length of hospital stay were decreased by GDFR protocol as compared to conventional fluid therapy (all P<0.05). However, there were no significant differences between groups with respect to the concentration of serum tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), and interleukin-10 (IL-10). The GDFR protocol based on SVV and cardiac index applied in patients undergoing OLV improves intraoperative pulmonary oxygenation. It can also reduce the postoperative complications and length of hospital stay. However, the

  8. Premeiotic microsporocyte cell shape influences shape of tetrads during microsporogenesis

    OpenAIRE

    Penet, Laurent

    2012-01-01

    Angiosperm microspores are grouped into tetrads before they mature into functional pollen grains. This tetrad stage is an important step in microsporogenesis. Tetrad shapes are diverse across angiosperms, with high levels of variation sometimes occurring within species, reflecting variation in early developmental events of nuclear and cell division (i.e., meiosis and cytokinesis). Among these developmental influences, the shape of the microsporocyte (pollen mother cell; hereafter PMC) is like...

  9. Impact of short-term climate variation and hydrology change on thermal structure and water quality of a canyon-shaped, stratified reservoir.

    Science.gov (United States)

    Ma, Wei-Xing; Huang, Ting-Lin; Li, Xuan; Zhang, Hai-Han; Ju, Tuo

    2015-12-01

    Climate variation can have obvious effects on hydrologic conditions, which in turn can have direct consequences for the thermal regime and quality of water for human use. In this research, weekly surveys were conducted from 2011 to 2013 to investigate how changes of climate and hydrology affect the thermal regime and water quality at the Heihe Reservoir. Our results show that the hydrology change during the flooding season can both increase the oxygen concentration and accelerate the consumption of dissolved oxygen. Continuous heavy rainfall events occurred in September 2011 caused the mixing of the entire reservoir, which led to an increase in dissolved oxygen at the bottom until the next year. Significant turbid density flow was observed following the extreme rainfall events in 2012 which leading to a rapid increase in turbidity at the bottom (up to 3000 NTU). Though the dissolved oxygen at the bottom increased from 0 to 9.02 mg/L after the rainfall event, it became anoxic within 20 days due to the increase of water oxygen demand caused by the suspended matter brought by the storm runoff. The release of compounds from the sediments was more serious during the anaerobic period after the rainfall events and the concentration of total iron, total phosphorus, and total manganese at the bottom reached 1.778, 0.102, and 0.125 mg/L. The improved water-lifting aerators kept on running after the storm runoff occurred in 2013 to avoid the deterioration of water quality during anaerobic conditions and ensured the good water quality during the mixing period. Our results suggest preventive and remediation actions that are necessary to improve water quality and status.

  10. Shape analysis in medical image analysis

    CERN Document Server

    Tavares, João

    2014-01-01

    This book contains thirteen contributions from invited experts of international recognition addressing important issues in shape analysis in medical image analysis, including techniques for image segmentation, registration, modelling and classification, and applications in biology, as well as in cardiac, brain, spine, chest, lung and clinical practice. This volume treats topics such as, anatomic and functional shape representation and matching; shape-based medical image segmentation; shape registration; statistical shape analysis; shape deformation; shape-based abnormity detection; shape tracking and longitudinal shape analysis; machine learning for shape modeling and analysis; shape-based computer-aided-diagnosis; shape-based medical navigation; benchmark and validation of shape representation, analysis and modeling algorithms. This work will be of interest to researchers, students, and manufacturers in the fields of artificial intelligence, bioengineering, biomechanics, computational mechanics, computationa...

  11. Pairwise harmonics for shape analysis

    KAUST Repository

    Zheng, Youyi

    2013-07-01

    This paper introduces a simple yet effective shape analysis mechanism for geometry processing. Unlike traditional shape analysis techniques which compute descriptors per surface point up to certain neighborhoods, we introduce a shape analysis framework in which the descriptors are based on pairs of surface points. Such a pairwise analysis approach leads to a new class of shape descriptors that are more global, discriminative, and can effectively capture the variations in the underlying geometry. Specifically, we introduce new shape descriptors based on the isocurves of harmonic functions whose global maximum and minimum occur at the point pair. We show that these shape descriptors can infer shape structures and consistently lead to simpler and more efficient algorithms than the state-of-the-art methods for three applications: intrinsic reflectional symmetry axis computation, matching shape extremities, and simultaneous surface segmentation and skeletonization. © 2012 IEEE.

  12. Gray Matter Volume and Resting-State Functional Connectivity of the Motor Cortex-Cerebellum Network Reflect the Individual Variation in Masticatory Performance in Healthy Elderly People.

    Science.gov (United States)

    Lin, Chia-Shu; Wu, Shih-Yun; Wu, Ching-Yi; Ko, Hsien-Wei

    2015-01-01

    Neuroimaging studies have consistently identified brain activation in the motor area and the cerebellum during chewing. In this study, we further investigated the structural and functional brain signature associated with masticatory performance, which is a widely used index for evaluating overall masticatory function in the elderly. Twenty-five healthy elderly participants underwent oral examinations, masticatory performance tests, and behavioral assessments, including the Cognitive Abilities Screening Instrument and the short-form Geriatric Depression Scale. Masticatory performance was assessed with the validated colorimetric method, using color-changeable chewing gum. T1-weighted structural magnetic resonance imaging (MRI) and resting-state function MRI were performed. We analyzed alterations in gray matter volume (GMV) using voxel-based morphometry and resting-state functional connectivity (rsFC) between brain regions using the seed-based method. The structural and functional MRI analyses revealed the following findings: (1) the GMV change in the premotor cortex was positively correlated with masticatory performance. (2) The rsFC between the cerebellum and the premotor cortex was positively correlated with masticatory performance. (3) The GMV changes in the dorsolateral prefrontal cortex (DLPFC), as well as the rsFC between the cerebellum and the DLPFC, were positively correlated with masticatory performance. The findings showed that in the premotor cortex, a reduction of GMV and rsFC would reflect declined masticatory performance. The positive correlation between DLPFC connectivity and masticatory performance implies that masticatory ability is associated with cognitive function in the elderly. Our findings highlighted the role of the central nervous system in masticatory performance and increased our understanding of the structural and functional brain signature underlying individual variations in masticatory performance in the elderly.

  13. Grey matter volume and resting-state functional connectivity of the motor cortex-cerebellum network reflect the individual variation in masticatory performance in the healthy elderly people

    Directory of Open Access Journals (Sweden)

    Chia-Shu eLin

    2016-01-01

    Full Text Available Neuroimaging studies have consistently identified brain activation in the motor area and the cerebellum during chewing. In this study, we further investigated the structural and functional brain signature associated with masticatory performance, which is a widely used index for evaluating overall masticatory function in the elderly. Twenty-five healthy elderly participants underwent oral examinations, masticatory performance tests, and behavioral assessments, including the Cognitive Abilities Screening Instrument and the short-form Geriatric Depression Scale. Masticatory performance was assessed with the validated colorimetric method, using color-changeable chewing gum. T1-weighted structural magnetic resonance imaging (MRI and resting-state function MRI were performed. We analyzed alterations in grey matter volume (GMV using voxel-based morphometry and resting-state functional connectivity (rsFC between brain regions using the seed-based method. The structural and functional MRI analyses revealed the following findings: (1 the GMV change in the premotor cortex was positively correlated with masticatory performance. (2 The rsFC between the cerebellum and the premotor cortex was positively correlated with masticatory performance. (3 The GMV changes in the dorsolateral prefrontal cortex (DLPFC, as well as the rsFC between the cerebellum and the DLPFC, was positively correlated with masticatory performance. The findings showed that in the premotor cortex, a reduction of GMV and rsFC would reflect declined masticatory performance. The positive correlation between DLPFC connectivity and masticatory performance implies that masticatory ability is associated with cognitive function in the elderly. Our findings highlighted the role of the central nervous system in masticatory performance and increased our understanding of the structural and functional brain signature underlying individual variations in masticatory performance in the elderly.

  14. Shape integral method for magnetospheric shapes. [boundary layer calculations

    Science.gov (United States)

    Michel, F. C.

    1979-01-01

    A method is developed for calculating the shape of any magnetopause to arbitrarily high precision. The method uses an integral equation which is evaluated for a trial shape. The resulting values of the integral equation as a function of auxiliary variables indicate how close one is to the desired solution. A variational method can then be used to improve the trial shape. Some potential applications are briefly mentioned.

  15. Towards robust and effective shape modeling: sparse shape composition.

    Science.gov (United States)

    Zhang, Shaoting; Zhan, Yiqiang; Dewan, Maneesh; Huang, Junzhou; Metaxas, Dimitris N; Zhou, Xiang Sean

    2012-01-01

    Organ shape plays an important role in various clinical practices, e.g., diagnosis, surgical planning and treatment evaluation. It is usually derived from low level appearance cues in medical images. However, due to diseases and imaging artifacts, low level appearance cues might be weak or misleading. In this situation, shape priors become critical to infer and refine the shape derived by image appearances. Effective modeling of shape priors is challenging because: (1) shape variation is complex and cannot always be modeled by a parametric probability distribution; (2) a shape instance derived from image appearance cues (input shape) may have gross errors; and (3) local details of the input shape are difficult to preserve if they are not statistically significant in the training data. In this paper we propose a novel Sparse Shape Composition model (SSC) to deal with these three challenges in a unified framework. In our method, a sparse set of shapes in the shape repository is selected and composed together to infer/refine an input shape. The a priori information is thus implicitly incorporated on-the-fly. Our model leverages two sparsity observations of the input shape instance: (1) the input shape can be approximately represented by a sparse linear combination of shapes in the shape repository; (2) parts of the input shape may contain gross errors but such errors are sparse. Our model is formulated as a sparse learning problem. Using L1 norm relaxation, it can be solved by an efficient expectation-maximization (EM) type of framework. Our method is extensively validated on two medical applications, 2D lung localization in X-ray images and 3D liver segmentation in low-dose CT scans. Compared to state-of-the-art methods, our model exhibits better performance in both studies. Copyright © 2011 Elsevier B.V. All rights reserved.

  16. PubChem3D: Diversity of shape

    Directory of Open Access Journals (Sweden)

    Bolton Evan E

    2011-03-01

    Full Text Available Abstract Background The shape diversity of 16.4 million biologically relevant molecules from the PubChem Compound database and their 1.46 billion diverse conformers was explored as a function of molecular volume. Results The diversity of shape space was investigated by determining the shape similarity threshold to achieve a maximum on the count of reference shapes per unit of conformer volume. The rate of growth in shape space, as represented by a decreasing shape similarity threshold, was found to be remarkably smooth as a function of volume. There was no apparent correlation between the count of conformers per unit volume and their diversity, meaning that a single reference shape can describe the shape space of many chemical structures. The ability of a volume to describe the shape space of lesser volumes was also examined. It was shown that a given volume was able to describe 40-70% of the shape diversity of lesser volumes, for the majority of the volume range considered in this study. Conclusion The relative growth of shape diversity as a function of volume and shape similarity is surprisingly uniform. Given the distribution of chemicals in PubChem versus what is theoretically synthetically possible, the results from this analysis should be considered a conservative estimate to the true diversity of shape space.

  17. Listening to the Shape of a Drum

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 3; Issue 10. Listening to the Shape of a Drum - You Cannot Hear the Shape of a Drum! S Kesavan. General Article Volume 3 Issue 10 October 1998 pp 49-58. Fulltext. Click here to view fulltext PDF. Permanent link:

  18. Automatic shape model building based on principal geodesic analysis bootstrapping

    DEFF Research Database (Denmark)

    Dam, Erik B; Fletcher, P Thomas; Pizer, Stephen M

    2008-01-01

    We present a novel method for automatic shape model building from a collection of training shapes. The result is a shape model consisting of the mean model and the major modes of variation with a dense correspondence map between individual shapes. The framework consists of iterations where a medial...... shape representation is deformed into the training shapes followed by computation of the shape mean and modes of shape variation. In the first iteration, a generic shape model is used as starting point - in the following iterations in the bootstrap method, the resulting mean and modes from the previous...... iteration are used. Thereby, we gradually capture the shape variation in the training collection better and better. Convergence of the method is explicitly enforced. The method is evaluated on collections of artificial training shapes where the expected shape mean and modes of variation are known by design...

  19. Small relief shape variations influence spatial variability of soil chemical attributes Pequenas variações das formas de relevo influenciam a variabilidade espacial de atributos químicos do solo

    Directory of Open Access Journals (Sweden)

    Zigomar Menezes de Souza

    2006-04-01

    Full Text Available Soils with small variations in relief and under the same management system present differentiated spatial variabilities of their attributes. This variability is a function of soil position in the landscape, even if the relief has little expression. The aim of this work was to investigate the effects of relief shape and depth on spatial variability of soil chemical attributes in a Typic Hapludox cultivated with sugar cane at two landscape compartments. Soil samples were collected in the intercrossing points of a grid, in the traffic line, at 0-0.2 m and 0.6-0.8 m depths, comprising a set of 100 georeferenced points. The spatial variabilities of pH, P, K, Ca, Mg, cation exchange capacity and base saturation were quantified. Small relief shape variations lead to differentiated variability in soil chemical attributes as indicated by the dependence on pedoform found for chemical attributes at both 0-0.2 m and 0.6-0.8 m depths. Because of the higher variability, it is advisable to collect large number of samples in areas with concave and convex shapes. Combining relief shapes and geostatistics allows the determination of areas with different spatial variability for soil chemical attributes.Solos submetidos ao mesmo sistema de manejo em locais com pequena variação de relevo, manifestam variabilidade espacial diferenciada de seus atributos. Esta variabilidade é condicionada pela posição dos solos na paisagem ou no declive, mesmo que o relevo seja de pequena expressão. O estudo teve como objetivo avaliar a influência da forma do relevo na variabilidade espacial de atributos químicos em um latossolo cultivado com cana-de-açúcar em dois compartimentos da paisagem. Os solos foram amostrados nos pontos de cruzamento de uma malha, com intervalos regulares de 10 m, perfazendo um total de 100 pontos, nas profundidades de 0-0,2 m e 0,6-0,8 m. Foi avaliado a variabilidade espacial do pH, fósforo (P, potássio (K, cálcio (Ca, magnésio (Mg, acidez

  20. Combined Shape and Topology Optimization

    DEFF Research Database (Denmark)

    Christiansen, Asger Nyman

    Shape and topology optimization seeks to compute the optimal shape and topology of a structure such that one or more properties, for example stiffness, balance or volume, are improved. The goal of the thesis is to develop a method for shape and topology optimization which uses the Deformable...... Simplicial Complex (DSC) method. Consequently, we present a novel method which combines current shape and topology optimization methods. This method represents the surface of the structure explicitly and discretizes the structure into non-overlapping elements, i.e. a simplicial complex. An explicit surface...... representation usually limits the optimization to minor shape changes. However, the DSC method uses a single explicit representation and still allows for large shape and topology changes. It does so by constantly applying a set of mesh operations during deformations of the structure. Using an explicit instead...

  1. Avaliação cronológica da variação no volume globular sanguíneo de bovinos leiteiros Cronological evaluation of variation in packed cell volume on dairy cattle

    Directory of Open Access Journals (Sweden)

    Wilmar Sachetin Marçal

    1995-01-01

    Full Text Available Os autores avaliaram a variação no volume globular sangüíneo de 321 bovinos da raça Holandês preta e branca, sadios e criados em granjas leiteiras no Estado de São Paulo. Todos os animais trabalhados na presente pesquisa eram sadios, não reagentes ao vírus da Leucose Bovina, livres de hemoparasitas, brucelose e tuberculose. O volume globular sangüíneo foi efetuado através do método do hematócrito com tubos capilares. Os resultados mostram haver influência da idade sobre o volume globular sangüíneo, com valores médios encontrados de 30,12 ± 2,72%.The packet cell volume was evaluated by the authors in 321 healthy female Holstein cattle raised at Campinas dairy region. São Paulo State. All the animais used in this assay were healthy and free of Leucosis, Tuberculosis, Brucellosis and blood parasites. The packed cell volume has been studied by method of hematocrit with capilary tubos. The results showed an influence of age on packed cell volume with average reference values of 30.12 ± 2.72%.

  2. Variations du volume pulmonaire au cours de la ventilation mécanique : modes ventilatoires et manœuvres positionnelles

    OpenAIRE

    Dellamonica, Jean

    2012-01-01

    The acute respiratory distress syndrome (ARDS) is a frequent and severe form of acute respiratory failure. Mechanical ventilation is the cornerstone of treatment but it may induce a specific form of lung injury (Ventilator induced Lung Injury) responsible for superimposed morbidity and mortality. Lung volume is dramatically decreased during ARDS. Lung volume measurements remained limited to clinical research until recently when the nitrogen washout/washin technique has been adapted for bedsid...

  3. Dynamic shape.

    Science.gov (United States)

    Koenderink, J J; van Doorn, A J

    1986-01-01

    Many useful notions of partial order and/or similarity and relatedness of different geometrical features of smooth shapes that occur in psychologically valid descriptions of shape have no equivalents in the usual geometrical shape theories. This is especially true where similarities are noted between objects of different connectivity: in almost all of the present theories the topological type generates the primary categorization. It is argued that such relations find a logical place only in shape theories that involve morphogenesis. Any object can be embedded uniquely in a morphogenetic sequence if one takes resolution as the parameter of the sequence. A theory of measurement is presented that allows one to define surfaces and (boundary-) curves on multiple levels of resolution. The embedding is essentially unique and is generated via a partial differential equation that governs the evolution. A canonical projection connects any high resolution specimen to lower resolution versions. The bifurcation set of the projection generates natural part boundaries. Singularities of the evolution are completely characterized as emergence, accretion and versification processes (involving topological change) and singularities by which inflections (inflection points for curves, parabolic curves for surfaces) are generated. The latter singularities involve a single process for the generation of inflections and three other processes by which the existing inflection structure may be changed. Relations with existing theories in vogue in robotics and AI, as well as in psychophysics are discussed.

  4. NONCONVEX REGULARIZATION FOR SHAPE PRESERVATION

    Energy Technology Data Exchange (ETDEWEB)

    CHARTRAND, RICK [Los Alamos National Laboratory

    2007-01-16

    The authors show that using a nonconvex penalty term to regularize image reconstruction can substantially improve the preservation of object shapes. The commonly-used total-variation regularization, {integral}|{del}u|, penalizes the length of the object edges. They show that {integral}|{del}u|{sup p}, 0 < p < 1, only penalizes edges of dimension at least 2-p, and thus finite-length edges not at all. We give numerical examples showing the resulting improvement in shape preservation.

  5. Women in Shape Modeling Workshop

    CERN Document Server

    Tari, Sibel

    2015-01-01

    Presenting the latest research from the growing field of mathematical shape analysis, this volume is comprised of the collaborations of participants of the Women in Shape Modeling (WiSh) workshop, held at UCLA's Institute for Pure and Applied Mathematics in July 2013. Topics include: Simultaneous spectral and spatial analysis of shape Dimensionality reduction and visualization of data in tree-spaces, such as classes of anatomical trees like airways and blood vessels Geometric shape segmentation, exploring shape segmentation from a Gestalt perspective, using information from the Blum medial axis of edge fragments in an image Representing and editing self-similar details on 3D shapes, studying shape deformation and editing techniques Several chapters in the book directly address the problem of continuous measures of context-dependent nearness and right shape models. Medical and biological applications have been a major source of motivation in shape research, and key topics are examined here in detail. All...

  6. Surface shape memory in polymers

    Science.gov (United States)

    Mather, Patrick

    2012-02-01

    Many crosslinked polymers exhibit a shape memory effect wherein a permanent shape can be prescribed during crosslinking and arbitrary temporary shapes may be set through network chain immobilization. Researchers have extensively investigated such shape memory polymers in bulk form (bars, films, foams), revealing a multitude of approaches. Applications abound for such materials and a significant fraction of the studies in this area concern application-specific characterization. Recently, we have turned our attention to surface shape memory in polymers as a means to miniaturization of the effect, largely motivated to study the interaction of biological cells with shape memory polymers. In this presentation, attention will be given to several approaches we have taken to prepare and study surface shape memory phenomenon. First, a reversible embossing study involving a glassy, crosslinked shape memory material will be presented. Here, the permanent shape was flat while the temporary state consisted of embossed parallel groves. Further the fixing mechanism was vitrification, with Tg adjusted to accommodate experiments with cells. We observed that the orientation and spreading of adherent cells could be triggered to change by the topographical switch from grooved to flat. Second, a functionally graded shape memory polymer will be presented, the grading being a variation in glass transition temperature in one direction along the length of films. Characterization of the shape fixing and recovery of such films utilized an indentation technique that, along with polarizing microscopy, allowed visualization of stress distribution in proximity to the indentations. Finally, very recent research concerning shape memory induced wrinkle formation on polymer surfaces will be presented. A transformation from smooth to wrinkled surfaces at physiological temperatures has been observed to have a dramatic effect on the behavior of adherent cells. A look to the future in research and

  7. Renormalized Volume

    Science.gov (United States)

    Gover, A. Rod; Waldron, Andrew

    2017-09-01

    We develop a universal distributional calculus for regulated volumes of metrics that are suitably singular along hypersurfaces. When the hypersurface is a conformal infinity we give simple integrated distribution expressions for the divergences and anomaly of the regulated volume functional valid for any choice of regulator. For closed hypersurfaces or conformally compact geometries, methods from a previously developed boundary calculus for conformally compact manifolds can be applied to give explicit holographic formulæ for the divergences and anomaly expressed as hypersurface integrals over local quantities (the method also extends to non-closed hypersurfaces). The resulting anomaly does not depend on any particular choice of regulator, while the regulator dependence of the divergences is precisely captured by these formulæ. Conformal hypersurface invariants can be studied by demanding that the singular metric obey, smoothly and formally to a suitable order, a Yamabe type problem with boundary data along the conformal infinity. We prove that the volume anomaly for these singular Yamabe solutions is a conformally invariant integral of a local Q-curvature that generalizes the Branson Q-curvature by including data of the embedding. In each dimension this canonically defines a higher dimensional generalization of the Willmore energy/rigid string action. Recently, Graham proved that the first variation of the volume anomaly recovers the density obstructing smooth solutions to this singular Yamabe problem; we give a new proof of this result employing our boundary calculus. Physical applications of our results include studies of quantum corrections to entanglement entropies.

  8. Critical Climate-Sensitive and Important Grain-Producing Regions: Grain Production/Yield Variations Due to Climate Fluctuations. Volume 1

    Science.gov (United States)

    Welker, J. E.

    2004-01-01

    Ideally, the Crop Country Inventory, CCI, is a methodology for the pre-harvest prediction of large variations in a country s crop production. This is accomplished by monitoring the historical climatic fluctuations, especially during the crop calendar period, in a climate sensitive large crop production region or sub-country, rather than the entire country. The argument can be made that the climatic fluctuations in the climatic sensitive region are responsible for the major annual crop country variations and that the remainder of the country, without major climatic fluctuations for a given year, can be assumed to be a steady-state crop producer. The principal data set that has been used is the Global Climate Mode (GCM) data from the National Center for Environmental Prediction (NCEP), taken over the last half century. As a test of its accuracy, GCM data can and has been correlated with the actual meteorological station data at the station site.

  9. Optimal shapes for best draining

    Science.gov (United States)

    Sherwood, J. D.

    2009-11-01

    The container shape that minimizes the volume of draining fluid remaining on the walls of the container after it has been emptied from its base is determined. The film of draining fluid is assumed to wet the walls of the container, and is sufficiently thin so that its curvature may be neglected. Surface tension is ignored. The initial value problem for the thickness of a film of Newtonian fluid is studied, and is shown to lead asymptotically to a similarity solution. From this, and from equivalent solutions for power-law fluids, the volume of the residual film is determined. The optimal container shape is not far from hemispherical, to minimize the surface area, but has a conical base to promote draining. The optimal shape for an axisymmetric mixing vessel, with a hole at the center of its base for draining, is also optimal when inverted in the manner of a washed wine glass inverted and left to drain.

  10. Updated Methods for Seed Shape Analysis

    Directory of Open Access Journals (Sweden)

    Emilio Cervantes

    2016-01-01

    Full Text Available Morphological variation in seed characters includes differences in seed size and shape. Seed shape is an important trait in plant identification and classification. In addition it has agronomic importance because it reflects genetic, physiological, and ecological components and affects yield, quality, and market price. The use of digital technologies, together with development of quantification and modeling methods, allows a better description of seed shape. Image processing systems are used in the automatic determination of seed size and shape, becoming a basic tool in the study of diversity. Seed shape is determined by a variety of indexes (circularity, roundness, and J index. The comparison of the seed images to a geometrical figure (circle, cardioid, ellipse, ellipsoid, etc. provides a precise quantification of shape. The methods of shape quantification based on these models are useful for an accurate description allowing to compare between genotypes or along developmental phases as well as to establish the level of variation in different sets of seeds.

  11. Multiscale 3D shape analysis using spherical wavelets.

    Science.gov (United States)

    Nain, Delphine; Haker, Steven; Bobick, Aaron; Tannenbaum, Allen R

    2005-01-01

    Shape priors attempt to represent biological variations within a population. When variations are global, Principal Component Analysis (PCA) can be used to learn major modes of variation, even from a limited training set. However, when significant local variations exist, PCA typically cannot represent such variations from a small training set. To address this issue, we present a novel algorithm that learns shape variations from data at multiple scales and locations using spherical wavelets and spectral graph partitioning. Our results show that when the training set is small, our algorithm significantly improves the approximation of shapes in a testing set over PCA, which tends to oversmooth data.

  12. Shape-Morphing Nanocomposite Origami

    Science.gov (United States)

    2015-01-01

    Nature provides a vast array of solid materials that repeatedly and reversibly transform in shape in response to environmental variations. This property is essential, for example, for new energy-saving technologies, efficient collection of solar radiation, and thermal management. Here we report a similar shape-morphing mechanism using differential swelling of hydrophilic polyelectrolyte multilayer inkjets deposited on an LBL carbon nanotube (CNT) composite. The out-of-plane deflection can be precisely controlled, as predicted by theoretical analysis. We also demonstrate a controlled and stimuli-responsive twisting motion on a spiral-shaped LBL nanocomposite. By mimicking the motions achieved in nature, this method offers new opportunities for the design and fabrication of functional stimuli-responsive shape-morphing nanoscale and microscale structures for a variety of applications. PMID:24689908

  13. The added value of cardiac index and pulse pressure variation monitoring to mean arterial pressure-guided volume therapy in moderate-risk abdominal surgery (COGUIDE): a pragmatic multicentre randomised controlled trial.

    Science.gov (United States)

    Stens, J; Hering, J-P; van der Hoeven, C W P; Boom, A; Traast, H S; Garmers, L E; Loer, S A; Boer, C

    2017-09-01

    There is disagreement regarding the benefits of goal-directed therapy in moderate-risk abdominal surgery. Therefore, we tested the hypothesis that the addition of non-invasive cardiac index and pulse pressure variation monitoring to mean arterial pressure-based goal-directed therapy would reduce the incidence of postoperative complications in patients having moderate-risk abdominal surgery. In this pragmatic multicentre randomised controlled trial, we randomly allocated 244 patients by envelope drawing in a 1:1 fashion, stratified per centre. All patients had mean arterial pressure, cardiac index and pulse pressure variation measured continuously. In one group, healthcare professionals were blinded to cardiac index and pulse pressure variation values and were asked to guide haemodynamic therapy only based on mean arterial pressure (control group). In the second group, cardiac index and pulse pressure variation values were displayed and kept within target ranges following a pre-defined algorithm (CI-PPV group). The primary endpoint was the incidence of postoperative complications within 30 days. One hundred and seventy-five patients were eligible for final analysis. Overall complication rates were similar (42/94 (44.7%) vs. 38/81 (46.9%) in the control and CI-PPV groups, respectively; p = 0.95). The CI-PPV group had lower mean (SD) pulse pressure variation values (9.5 (2.0)% vs. 11.9 (4.6)%; p = 0.003) and higher mean (SD) cardiac indices (2.76 (0.62) l min-1 .m-2 vs. 2.53 (0.66) l min-1 .m-2 ; p = 0.004) than the control group. In moderate-risk abdominal surgery, we observed no additional value of cardiac index and pulse pressure variation-guided haemodynamic therapy to mean arterial pressure-guided volume therapy with regard to postoperative complications. © 2017 The Association of Anaesthetists of Great Britain and Ireland.

  14. Listening to the Shape of a Drum

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 3; Issue 9. Listening to the Shape of a Drum - The Mathematics of Vibrating Drums. S Kesavan. General Article Volume 3 Issue 9 September 1998 pp 26-34. Fulltext. Click here to view fulltext PDF. Permanent link:

  15. Quantum Computation with Ultrafast Laser Pulse Shaping

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 10; Issue 6. Quantum Computation with Ultrafast Laser Pulse Shaping. Debabrata Goswami. General Article Volume 10 Issue 6 June 2005 pp 8-14. Fulltext. Click here to view fulltext PDF. Permanent link:

  16. Body shape model, physical activity and eating behaviour.

    Science.gov (United States)

    Jáuregui Lobera, I; Tomillo Cid, S; Santiago Fernández, M J; Bolaños Ríos, P

    2011-01-01

    Research on the influence of body shape model on adolescent males is scarce. The current study aimed to assess this influence among adult males involved in intense physical activity and to determine its relationship to eating behaviour. Possible variations between 1998 and 2008 were also analysed. A total of 950 males (672 in 1998 and 278 in 2008), all aspiring professional soldiers, were studied using the Questionnaire of Influences on Body Shape Model (CIMEC-V) and the Eating Attitudes Test-40 (EAT-40), as well as by assessing their physical/sporting activity and body mass index (BMI). Scores on the CIMEC-V were significantly correlated with the EAT-40 and BMI. As regards physical activity the only positive correlation referred to gym-based exercise. A cluster analysis revealed two subgroups with respect to physical activity, BMI, and scores on the CIMEC-V and EAT-40. One of them scored higher on these three variables and they also had a BMI > 25. The comparative study of data from 1998 and 2008 showed significant changes in some variables. Generally, the results differ considerably from those reported for younger samples (which would suggest a lower risk of disordered eating behaviour). However, there is a higher risk group in which the influence of body shape models, physical activity and eating behaviour are related to greater body volume. The influence of the body shape model on males has increased, especially as regards the influence of friends and in terms of behaviours aimed at weight loss.

  17. Direct gravimetric measurements of the mass of the antarctic aerosol collected by high volume sampler: PM10 summer seasonal variation at Terra Nova Bay.

    Science.gov (United States)

    Truzzi, Cristina; Lambertucci, Luca; Illuminati, Silvia; Annibaldi, Anna; Scarponi, Giuseppe

    2005-01-01

    An on-site procedure was set up for direct gravimetric measurement of the mass of aerosol collected using high volume impactors (aerodynamic size cut point of 10 microm, PM10); this knowledge has hitherto been unavailable. Using a computerized microbalance in a clean chemistry laboratory, under controlled temperature (+/-0.5 degrees C) and relative humidity (+/-1%), continuous, long time filter mass measurements (hours) were carried out before and after exposure, after a 48 h minimun equilibration at the laboratory conditions. The effect of the electrostatic charge was exhausted in 30-60 min, after which stable measurements were obtained. Measurements of filters exposed for 7-11 days (1.13 m3 min(-1)) in a coastal site near Terra Nova Bay (December 2000 - February 2001), gave results for aerosol mass in the order of 10-20 mg (SD approximately 2 mg), corresponding to atmospheric concentrations of 0.52-1.27 microg m(-3). Data show a seasonal behaviour in the PM10 content with an increase during December - early January, followed by a net decrease. The above results compare well with estimates obtained from proxy data for the Antarctic Peninsula (0.30 microg m(-3)), the Ronne Ice Shelf (1.49 microg m(-3)), and the South Pole (0.18 microg m(-3), summer 1974-1975, and 0.37 microg m(-3), average summer seasons 1975-1976 and 1977-1978), and from direct gravimetric measurements recently obtained from medium volume samplers at McMurdo station (downwind 3.39 microg m(-3), upwind 4.15 microg m(-3)) and at King George Island (2.5 microg m(-3), summer, particle diameter <20 microm). This finding opens the way to the direct measurement of the chemical composition of the Antarctic aerosol and, in turn, to a better knowledge of the snow/air relationships as required for the reconstruction of the chemical composition of past atmospheres from deep ice core data.

  18. Killer whale morphology - Variation in morphology of killer whale ecotypes

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — We are using elliptic Fourier analysis to determine the patterns of variation in morphology of dorsal fin shape, saddle patch shape, and eye patch shape of resident,...

  19. Locally Linear Diffeomorphic Metric Embedding (LLDME) for surface-based anatomical shape modeling.

    Science.gov (United States)

    Yang, Xianfeng; Goh, Alvina; Qiu, Anqi

    2011-05-01

    This paper presents the algorithm, Locally Linear Diffeomorphic Metric Embedding (LLDME), for constructing efficient and compact representations of surface-based brain shapes whose variations are characterized using Large Deformation Diffeomorphic Metric Mapping (LDDMM). Our hypothesis is that the shape variations in the infinite-dimensional diffeomorphic metric space can be captured by a low-dimensional space. To do so, traditional Locally Linear Embedding (LLE) that reconstructs a data point from its neighbors in Euclidean space is extended to LLDME that requires interpolating a shape from its neighbors in the infinite-dimensional diffeomorphic metric space. This is made possible through the conservation law of momentum derived from LDDMM. It indicates that initial momentum, a linear transformation of the initial velocity of diffeomorphic flows, at a fixed template shape determines the geodesic connecting the template to a subject's shape in the diffeomorphic metric space and becomes the shape signature of an individual subject. This leads to the compact linear representation of the nonlinear diffeomorphisms in terms of the initial momentum. Since the initial momentum is in a linear space, a shape can be approximated by a linear combination of its neighbors in the diffeomorphic metric space. In addition, we provide efficient computations for the metric distance between two shapes through the first order approximation of the geodesic using the initial momentum as well as for the reconstruction of a shape given its low-dimensional Euclidean coordinates using the geodesic shooting with the initial momentum as the initial condition. Experiments are performed on the hippocampal shapes of 302 normal subjects across the whole life span (18-94years). Compared with Principal Component Analysis and ISOMAP, LLDME provides the most compact and efficient representation of the age-related hippocampal shapes. Even though the hippocampal volumes among young adults are as

  20. Leaf shrinkage: a predictive indicator of the potential variation of the surface area-to-volume ratio according to the leaf moisture content.

    Science.gov (United States)

    Essaghi, Salaheddine; Hachmi, M'hamed; Yessef, Mohammed; Dehhaoui, Mohammed

    2016-01-01

    Leaf shrinkage provides insights into the potential variation of foliar SVR, within the same species, when leaf moisture content is changing in response to water deficit. Since SVR is among the most significant plant flammability features, leaf shrinkage would be a relevant component of fuel hazard assessment through its influence on SVR, enhancing-if it is taken into account-thereby the wildfire prediction accuracy. The purpose of this work is, first, to consider the leaf shrinkage by characterizing the plant species towards the shrinkability of their leaves, taking account the possible site effect, to characterize the behavior of shrinkage as a function of moisture content and finally to perform a classification for some dominant Mediterranean species based on the shrinkage levels. The assessment of the hierarchical relationships between the dimensional shrinkages is also aimed. Leaves and needles of thirteen tree and shrub species were harvested from six different sites in western Rif Mountains. Leaves dimensions and moisture content were measured regularly during a gradual drying at the laboratory. Dimensional shrinkages were calculated at each moisture content level. Dimensional shrinkages behaved similarly whether in leaf or timber and kept the same reporting relationships between each other. Among the species sampled in different sites, site effect is significant only in Pinus canariensis and Pistacia lentiscus. A classification of the plant species was carried out in three separate classes. Generally, shrinkage class of the plant species studied gave an idea on its flammability ranking reported in the literature, implying thus a cause-and-effect relationship between both parameters.

  1. Prediction of dementia by hippocampal shape analysis

    DEFF Research Database (Denmark)

    Achterberg, Hakim C.; van der Lijn, Fedde; den Heijer, Tom

    2010-01-01

    and, if necessary, manually corrected by a trained observer. From this data a statistical model of hippocampal shape was constructed, using an entropy-based particle system. This shape model provided the input for a Support Vector Machine classifier to predict dementia. Cross validation experiments......This work investigates the possibility of predicting future onset of dementia in subjects who are cognitively normal, using hippocampal shape and volume information extracted from MRI scans. A group of 47 subjects who were non-demented normal at the time of the MRI acquisition, but were diagnosed...... showed that shape information can predict future onset of dementia in this dataset with an accuracy of 70%. By incorporating both shape and volume information into the classifier, the accuracy increased to 74%....

  2. Zeptosecond precision pulse shaping.

    Science.gov (United States)

    Köhler, Jens; Wollenhaupt, Matthias; Bayer, Tim; Sarpe, Cristian; Baumert, Thomas

    2011-06-06

    We investigate the temporal precision in the generation of ultrashort laser pulse pairs by pulse shaping techniques. To this end, we combine a femtosecond polarization pulse shaper with a polarizer and employ two linear spectral phase masks to mimic an ultrastable common-path interferometer. In an all-optical experiment we study the interference signal resulting from two temporally delayed pulses. Our results show a 2σ-precision of 300 zs = 300 × 10(-21) s in pulse-to-pulse delay. The standard deviation of the mean is 11 zs. The obtained precision corresponds to a variation of the arm's length in conventional delay stage based interferometers of 0.45 Å. We apply these precisely generated pulse pairs to a strong-field quantum control experiment. Coherent control of ultrafast electron dynamics via photon locking by temporal phase discontinuities on a few attosecond timescale is demonstrated.

  3. Comparison of medical of volume measurement of the prostate by transrectal ultrasound: Experiment with jelly models

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Jeong Yeon; Lee, Hak Jong; Kim, Sung Hyun [Samsung Seoul Hospital, Sungkyunkwan University School of Medicine, Seoul (Korea, Republic of); Kim, Seung Hyup [Seoul National University College of Medicine, Seoul (Korea, Republic of)

    2002-03-15

    To evaluate the accuracy of measuring the volume of the prostate using the prolate ellipsoid volume calculation method (antero-posterior (AP) diameter X length X width X {pi}6) when the antero-posterior diameter of the prostate was measured on midsagittal (sagittal volume) and axial plane (axial volume).The devil's tongue jelly was used for the creation of ultrasound model of the prostate (volume: 15-40 cc) by cutting and shaping the surface. The volume in 10 prostatic models and 30 patients was measured and calculated. First, the AP diameter and length of the prostate models in midsagittal plane, and the height and width of the models in axial plane were measured for 3 times. The volume was calculated in two ways, one using the AP diameter an midsagittal plane and the other using the AP diameter in axial plane. The true volume of the model was measured using mess cylinder. The calculated volume and true volume were compared, and the accuracy of two method of measuring the prostatic volume was evaluated by Friedman test. The intraobserver variation was evaluated by General Linear Model, Repeated Measure. The reproducibility was evaluated by Cronbach's {alpha}. In vivo study was also performed in 30 patients. The prostate volume was calculated in the same manner. These volume data were analyzed by statistical method, and the intraobeserver variation was evaluated. While there was a statistically significant difference between the sagittal and true volume of the models, there was no statistical significant difference between the axial and true volumes. There was no significant intraobserver variation between both methods. The reproducibility was high in both methods with Cronbach's {alpha} of 0.977 and 0.942. The sagittal volume was larger than the axial volume in 30 patients with a statistically significant difference. There was no significant intraobserver variation in both methods. The reproducibility was high in both methods Cronbach's {alpha

  4. Quantitative assessment of brain volumes in fish: comparison of methodologies.

    Science.gov (United States)

    Ullmann, Jeremy F P; Cowin, Gary; Collin, Shaun P

    2010-01-01

    When correlating brain areas with behavioral and environmental characteristics, a variety of techniques are employed. In fishes (elasmobranchs and teleosts), 2 methods, histology and the idealized ellipsoid and/or half-ellipsoid technique, are primarily used to calculate the volume of a brain area and therefore its relationship to social or ecological complexity. In this study on a perciform teleost, we have quantitatively compared brain volumes obtained using the conventional techniques of histology and approximating brain volume to an idealized ellipsoid (or half ellipsoid) and magnetic resonance imaging, an established clinical tool typically used for assessing brain volume in other vertebrates. Our results indicate that, when compared to brain volumes measured using magnetic resonance imaging of brain regions in situ, variations in brain shape and histological artifacts can lead to significant differences in brain volume, especially in the telencephalon and optic tecta. Consequently, in comparative studies of brain volumes, we advise caution when using the histological and/or ellipsoid methods to make correlations between brain area size and environmental, behavioral and social characteristics and, when possible, we propose the use of magnetic resonance imaging. Copyright © 2010 S. Karger AG, Basel.

  5. Variational methods for crystalline microstructure analysis and computation

    CERN Document Server

    Dolzmann, Georg

    2003-01-01

    Phase transformations in solids typically lead to surprising mechanical behaviour with far reaching technological applications. The mathematical modeling of these transformations in the late 80s initiated a new field of research in applied mathematics, often referred to as mathematical materials science, with deep connections to the calculus of variations and the theory of partial differential equations. This volume gives a brief introduction to the essential physical background, in particular for shape memory alloys and a special class of polymers (nematic elastomers). Then the underlying mathematical concepts are presented with a strong emphasis on the importance of quasiconvex hulls of sets for experiments, analytical approaches, and numerical simulations.

  6. Novel genetic loci associated with hippocampal volume

    Science.gov (United States)

    Hibar, Derrek P.; Adams, Hieab H. H.; Jahanshad, Neda; Chauhan, Ganesh; Stein, Jason L.; Hofer, Edith; Renteria, Miguel E.; Bis, Joshua C.; Arias-Vasquez, Alejandro; Ikram, M. Kamran; Desrivières, Sylvane; Vernooij, Meike W.; Abramovic, Lucija; Alhusaini, Saud; Amin, Najaf; Andersson, Micael; Arfanakis, Konstantinos; Aribisala, Benjamin S.; Armstrong, Nicola J.; Athanasiu, Lavinia; Axelsson, Tomas; Beecham, Ashley H.; Beiser, Alexa; Bernard, Manon; Blanton, Susan H.; Bohlken, Marc M.; Boks, Marco P.; Bralten, Janita; Brickman, Adam M.; Carmichael, Owen; Chakravarty, M. Mallar; Chen, Qiang; Ching, Christopher R. K.; Chouraki, Vincent; Cuellar-Partida, Gabriel; Crivello, Fabrice; Den Braber, Anouk; Doan, Nhat Trung; Ehrlich, Stefan; Giddaluru, Sudheer; Goldman, Aaron L.; Gottesman, Rebecca F.; Grimm, Oliver; Griswold, Michael E.; Guadalupe, Tulio; Gutman, Boris A.; Hass, Johanna; Haukvik, Unn K.; Hoehn, David; Holmes, Avram J.; Hoogman, Martine; Janowitz, Deborah; Jia, Tianye; Jørgensen, Kjetil N.; Karbalai, Nazanin; Kasperaviciute, Dalia; Kim, Sungeun; Klein, Marieke; Kraemer, Bernd; Lee, Phil H.; Liewald, David C. M.; Lopez, Lorna M.; Luciano, Michelle; Macare, Christine; Marquand, Andre F.; Matarin, Mar; Mather, Karen A.; Mattheisen, Manuel; McKay, David R.; Milaneschi, Yuri; Muñoz Maniega, Susana; Nho, Kwangsik; Nugent, Allison C.; Nyquist, Paul; Loohuis, Loes M. Olde; Oosterlaan, Jaap; Papmeyer, Martina; Pirpamer, Lukas; Pütz, Benno; Ramasamy, Adaikalavan; Richards, Jennifer S.; Risacher, Shannon L.; Roiz-Santiañez, Roberto; Rommelse, Nanda; Ropele, Stefan; Rose, Emma J.; Royle, Natalie A.; Rundek, Tatjana; Sämann, Philipp G.; Saremi, Arvin; Satizabal, Claudia L.; Schmaal, Lianne; Schork, Andrew J.; Shen, Li; Shin, Jean; Shumskaya, Elena; Smith, Albert V.; Sprooten, Emma; Strike, Lachlan T.; Teumer, Alexander; Tordesillas-Gutierrez, Diana; Toro, Roberto; Trabzuni, Daniah; Trompet, Stella; Vaidya, Dhananjay; Van der Grond, Jeroen; Van der Lee, Sven J.; Van der Meer, Dennis; Van Donkelaar, Marjolein M. J.; Van Eijk, Kristel R.; Van Erp, Theo G. M.; Van Rooij, Daan; Walton, Esther; Westlye, Lars T.; Whelan, Christopher D.; Windham, Beverly G.; Winkler, Anderson M.; Wittfeld, Katharina; Woldehawariat, Girma; Wolf, Christiane; Wolfers, Thomas; Yanek, Lisa R.; Yang, Jingyun; Zijdenbos, Alex; Zwiers, Marcel P.; Agartz, Ingrid; Almasy, Laura; Ames, David; Amouyel, Philippe; Andreassen, Ole A.; Arepalli, Sampath; Assareh, Amelia A.; Barral, Sandra; Bastin, Mark E.; Becker, Diane M.; Becker, James T.; Bennett, David A.; Blangero, John; van Bokhoven, Hans; Boomsma, Dorret I.; Brodaty, Henry; Brouwer, Rachel M.; Brunner, Han G.; Buckner, Randy L.; Buitelaar, Jan K.; Bulayeva, Kazima B.; Cahn, Wiepke; Calhoun, Vince D.; Cannon, Dara M.; Cavalleri, Gianpiero L.; Cheng, Ching-Yu; Cichon, Sven; Cookson, Mark R.; Corvin, Aiden; Crespo-Facorro, Benedicto; Curran, Joanne E.; Czisch, Michael; Dale, Anders M.; Davies, Gareth E.; De Craen, Anton J. M.; De Geus, Eco J. C.; De Jager, Philip L.; De Zubicaray, Greig I.; Deary, Ian J.; Debette, Stéphanie; DeCarli, Charles; Delanty, Norman; Depondt, Chantal; DeStefano, Anita; Dillman, Allissa; Djurovic, Srdjan; Donohoe, Gary; Drevets, Wayne C.; Duggirala, Ravi; Dyer, Thomas D.; Enzinger, Christian; Erk, Susanne; Espeseth, Thomas; Fedko, Iryna O.; Fernández, Guillén; Ferrucci, Luigi; Fisher, Simon E.; Fleischman, Debra A.; Ford, Ian; Fornage, Myriam; Foroud, Tatiana M.; Fox, Peter T.; Francks, Clyde; Fukunaga, Masaki; Gibbs, J. Raphael; Glahn, David C.; Gollub, Randy L.; Göring, Harald H. H.; Green, Robert C.; Gruber, Oliver; Gudnason, Vilmundur; Guelfi, Sebastian; Håberg, Asta K.; Hansell, Narelle K.; Hardy, John; Hartman, Catharina A.; Hashimoto, Ryota; Hegenscheid, Katrin; Heinz, Andreas; Le Hellard, Stephanie; Hernandez, Dena G.; Heslenfeld, Dirk J.; Ho, Beng-Choon; Hoekstra, Pieter J.; Hoffmann, Wolfgang; Hofman, Albert; Holsboer, Florian; Homuth, Georg; Hosten, Norbert; Hottenga, Jouke-Jan; Huentelman, Matthew; Pol, Hilleke E. Hulshoff; Ikeda, Masashi; Jack Jr, Clifford R.; Jenkinson, Mark; Johnson, Robert; Jönsson, Erik G.; Jukema, J. Wouter; Kahn, René S.; Kanai, Ryota; Kloszewska, Iwona; Knopman, David S.; Kochunov, Peter; Kwok, John B.; Lawrie, Stephen M.; Lemaître, Hervé; Liu, Xinmin; Longo, Dan L.; Lopez, Oscar L.; Lovestone, Simon; Martinez, Oliver; Martinot, Jean-Luc; Mattay, Venkata S.; McDonald, Colm; McIntosh, Andrew M.; McMahon, Francis J.; McMahon, Katie L.; Mecocci, Patrizia; Melle, Ingrid; Meyer-Lindenberg, Andreas; Mohnke, Sebastian; Montgomery, Grant W.; Morris, Derek W.; Mosley, Thomas H.; Mühleisen, Thomas W.; Müller-Myhsok, Bertram; Nalls, Michael A.; Nauck, Matthias; Nichols, Thomas E.; Niessen, Wiro J.; Nöthen, Markus M.; Nyberg, Lars; Ohi, Kazutaka; Olvera, Rene L.; Ophoff, Roel A.; Pandolfo, Massimo; Paus, Tomas; Pausova, Zdenka; Penninx, Brenda W. J. H.; Pike, G. Bruce; Potkin, Steven G.; Psaty, Bruce M.; Reppermund, Simone; Rietschel, Marcella; Roffman, Joshua L.; Romanczuk-Seiferth, Nina; Rotter, Jerome I.; Ryten, Mina; Sacco, Ralph L.; Sachdev, Perminder S.; Saykin, Andrew J.; Schmidt, Reinhold; Schmidt, Helena; Schofield, Peter R.; Sigursson, Sigurdur; Simmons, Andrew; Singleton, Andrew; Sisodiya, Sanjay M.; Smith, Colin; Smoller, Jordan W.; Soininen, Hilkka; Steen, Vidar M.; Stott, David J.; Sussmann, Jessika E.; Thalamuthu, Anbupalam; Toga, Arthur W.; Traynor, Bryan J.; Troncoso, Juan; Tsolaki, Magda; Tzourio, Christophe; Uitterlinden, Andre G.; Hernández, Maria C. Valdés; Van der Brug, Marcel; van der Lugt, Aad; van der Wee, Nic J. A.; Van Haren, Neeltje E. M.; van 't Ent, Dennis; Van Tol, Marie-Jose; Vardarajan, Badri N.; Vellas, Bruno; Veltman, Dick J.; Völzke, Henry; Walter, Henrik; Wardlaw, Joanna M.; Wassink, Thomas H.; Weale, Michael E.; Weinberger, Daniel R.; Weiner, Michael W.; Wen, Wei; Westman, Eric; White, Tonya; Wong, Tien Y.; Wright, Clinton B.; Zielke, Ronald H.; Zonderman, Alan B.; Martin, Nicholas G.; Van Duijn, Cornelia M.; Wright, Margaret J.; Longstreth, W. T.; Schumann, Gunter; Grabe, Hans J.; Franke, Barbara; Launer, Lenore J.; Medland, Sarah E.; Seshadri, Sudha; Thompson, Paul M.; Ikram, M. Arfan

    2017-01-01

    The hippocampal formation is a brain structure integrally involved in episodic memory, spatial navigation, cognition and stress responsiveness. Structural abnormalities in hippocampal volume and shape are found in several common neuropsychiatric disorders. To identify the genetic underpinnings of hippocampal structure here we perform a genome-wide association study (GWAS) of 33,536 individuals and discover six independent loci significantly associated with hippocampal volume, four of them novel. Of the novel loci, three lie within genes (ASTN2, DPP4 and MAST4) and one is found 200 kb upstream of SHH. A hippocampal subfield analysis shows that a locus within the MSRB3 gene shows evidence of a localized effect along the dentate gyrus, subiculum, CA1 and fissure. Further, we show that genetic variants associated with decreased hippocampal volume are also associated with increased risk for Alzheimer's disease (rg=−0.155). Our findings suggest novel biological pathways through which human genetic variation influences hippocampal volume and risk for neuropsychiatric illness. PMID:28098162

  7. Novel genetic loci associated with hippocampal volume.

    Science.gov (United States)

    Hibar, Derrek P; Adams, Hieab H H; Jahanshad, Neda; Chauhan, Ganesh; Stein, Jason L; Hofer, Edith; Renteria, Miguel E; Bis, Joshua C; Arias-Vasquez, Alejandro; Ikram, M Kamran; Desrivières, Sylvane; Vernooij, Meike W; Abramovic, Lucija; Alhusaini, Saud; Amin, Najaf; Andersson, Micael; Arfanakis, Konstantinos; Aribisala, Benjamin S; Armstrong, Nicola J; Athanasiu, Lavinia; Axelsson, Tomas; Beecham, Ashley H; Beiser, Alexa; Bernard, Manon; Blanton, Susan H; Bohlken, Marc M; Boks, Marco P; Bralten, Janita; Brickman, Adam M; Carmichael, Owen; Chakravarty, M Mallar; Chen, Qiang; Ching, Christopher R K; Chouraki, Vincent; Cuellar-Partida, Gabriel; Crivello, Fabrice; Den Braber, Anouk; Doan, Nhat Trung; Ehrlich, Stefan; Giddaluru, Sudheer; Goldman, Aaron L; Gottesman, Rebecca F; Grimm, Oliver; Griswold, Michael E; Guadalupe, Tulio; Gutman, Boris A; Hass, Johanna; Haukvik, Unn K; Hoehn, David; Holmes, Avram J; Hoogman, Martine; Janowitz, Deborah; Jia, Tianye; Jørgensen, Kjetil N; Karbalai, Nazanin; Kasperaviciute, Dalia; Kim, Sungeun; Klein, Marieke; Kraemer, Bernd; Lee, Phil H; Liewald, David C M; Lopez, Lorna M; Luciano, Michelle; Macare, Christine; Marquand, Andre F; Matarin, Mar; Mather, Karen A; Mattheisen, Manuel; McKay, David R; Milaneschi, Yuri; Muñoz Maniega, Susana; Nho, Kwangsik; Nugent, Allison C; Nyquist, Paul; Loohuis, Loes M Olde; Oosterlaan, Jaap; Papmeyer, Martina; Pirpamer, Lukas; Pütz, Benno; Ramasamy, Adaikalavan; Richards, Jennifer S; Risacher, Shannon L; Roiz-Santiañez, Roberto; Rommelse, Nanda; Ropele, Stefan; Rose, Emma J; Royle, Natalie A; Rundek, Tatjana; Sämann, Philipp G; Saremi, Arvin; Satizabal, Claudia L; Schmaal, Lianne; Schork, Andrew J; Shen, Li; Shin, Jean; Shumskaya, Elena; Smith, Albert V; Sprooten, Emma; Strike, Lachlan T; Teumer, Alexander; Tordesillas-Gutierrez, Diana; Toro, Roberto; Trabzuni, Daniah; Trompet, Stella; Vaidya, Dhananjay; Van der Grond, Jeroen; Van der Lee, Sven J; Van der Meer, Dennis; Van Donkelaar, Marjolein M J; Van Eijk, Kristel R; Van Erp, Theo G M; Van Rooij, Daan; Walton, Esther; Westlye, Lars T; Whelan, Christopher D; Windham, Beverly G; Winkler, Anderson M; Wittfeld, Katharina; Woldehawariat, Girma; Wolf, Christiane; Wolfers, Thomas; Yanek, Lisa R; Yang, Jingyun; Zijdenbos, Alex; Zwiers, Marcel P; Agartz, Ingrid; Almasy, Laura; Ames, David; Amouyel, Philippe; Andreassen, Ole A; Arepalli, Sampath; Assareh, Amelia A; Barral, Sandra; Bastin, Mark E; Becker, Diane M; Becker, James T; Bennett, David A; Blangero, John; van Bokhoven, Hans; Boomsma, Dorret I; Brodaty, Henry; Brouwer, Rachel M; Brunner, Han G; Buckner, Randy L; Buitelaar, Jan K; Bulayeva, Kazima B; Cahn, Wiepke; Calhoun, Vince D; Cannon, Dara M; Cavalleri, Gianpiero L; Cheng, Ching-Yu; Cichon, Sven; Cookson, Mark R; Corvin, Aiden; Crespo-Facorro, Benedicto; Curran, Joanne E; Czisch, Michael; Dale, Anders M; Davies, Gareth E; De Craen, Anton J M; De Geus, Eco J C; De Jager, Philip L; De Zubicaray, Greig I; Deary, Ian J; Debette, Stéphanie; DeCarli, Charles; Delanty, Norman; Depondt, Chantal; DeStefano, Anita; Dillman, Allissa; Djurovic, Srdjan; Donohoe, Gary; Drevets, Wayne C; Duggirala, Ravi; Dyer, Thomas D; Enzinger, Christian; Erk, Susanne; Espeseth, Thomas; Fedko, Iryna O; Fernández, Guillén; Ferrucci, Luigi; Fisher, Simon E; Fleischman, Debra A; Ford, Ian; Fornage, Myriam; Foroud, Tatiana M; Fox, Peter T; Francks, Clyde; Fukunaga, Masaki; Gibbs, J Raphael; Glahn, David C; Gollub, Randy L; Göring, Harald H H; Green, Robert C; Gruber, Oliver; Gudnason, Vilmundur; Guelfi, Sebastian; Håberg, Asta K; Hansell, Narelle K; Hardy, John; Hartman, Catharina A; Hashimoto, Ryota; Hegenscheid, Katrin; Heinz, Andreas; Le Hellard, Stephanie; Hernandez, Dena G; Heslenfeld, Dirk J; Ho, Beng-Choon; Hoekstra, Pieter J; Hoffmann, Wolfgang; Hofman, Albert; Holsboer, Florian; Homuth, Georg; Hosten, Norbert; Hottenga, Jouke-Jan; Huentelman, Matthew; Hulshoff Pol, Hilleke E; Ikeda, Masashi; Jack, Clifford R; Jenkinson, Mark; Johnson, Robert; Jönsson, Erik G; Jukema, J Wouter; Kahn, René S; Kanai, Ryota; Kloszewska, Iwona; Knopman, David S; Kochunov, Peter; Kwok, John B; Lawrie, Stephen M; Lemaître, Hervé; Liu, Xinmin; Longo, Dan L; Lopez, Oscar L; Lovestone, Simon; Martinez, Oliver; Martinot, Jean-Luc; Mattay, Venkata S; McDonald, Colm; McIntosh, Andrew M; McMahon, Francis J; McMahon, Katie L; Mecocci, Patrizia; Melle, Ingrid; Meyer-Lindenberg, Andreas; Mohnke, Sebastian; Montgomery, Grant W; Morris, Derek W; Mosley, Thomas H; Mühleisen, Thomas W; Müller-Myhsok, Bertram; Nalls, Michael A; Nauck, Matthias; Nichols, Thomas E; Niessen, Wiro J; Nöthen, Markus M; Nyberg, Lars; Ohi, Kazutaka; Olvera, Rene L; Ophoff, Roel A; Pandolfo, Massimo; Paus, Tomas; Pausova, Zdenka; Penninx, Brenda W J H; Pike, G Bruce; Potkin, Steven G; Psaty, Bruce M; Reppermund, Simone; Rietschel, Marcella; Roffman, Joshua L; Romanczuk-Seiferth, Nina; Rotter, Jerome I; Ryten, Mina; Sacco, Ralph L; Sachdev, Perminder S; Saykin, Andrew J; Schmidt, Reinhold; Schmidt, Helena; Schofield, Peter R; Sigursson, Sigurdur; Simmons, Andrew; Singleton, Andrew; Sisodiya, Sanjay M; Smith, Colin; Smoller, Jordan W; Soininen, Hilkka; Steen, Vidar M; Stott, David J; Sussmann, Jessika E; Thalamuthu, Anbupalam; Toga, Arthur W; Traynor, Bryan J; Troncoso, Juan; Tsolaki, Magda; Tzourio, Christophe; Uitterlinden, Andre G; Hernández, Maria C Valdés; Van der Brug, Marcel; van der Lugt, Aad; van der Wee, Nic J A; Van Haren, Neeltje E M; van 't Ent, Dennis; Van Tol, Marie-Jose; Vardarajan, Badri N; Vellas, Bruno; Veltman, Dick J; Völzke, Henry; Walter, Henrik; Wardlaw, Joanna M; Wassink, Thomas H; Weale, Michael E; Weinberger, Daniel R; Weiner, Michael W; Wen, Wei; Westman, Eric; White, Tonya; Wong, Tien Y; Wright, Clinton B; Zielke, Ronald H; Zonderman, Alan B; Martin, Nicholas G; Van Duijn, Cornelia M; Wright, Margaret J; Longstreth, W T; Schumann, Gunter; Grabe, Hans J; Franke, Barbara; Launer, Lenore J; Medland, Sarah E; Seshadri, Sudha; Thompson, Paul M; Ikram, M Arfan

    2017-01-18

    The hippocampal formation is a brain structure integrally involved in episodic memory, spatial navigation, cognition and stress responsiveness. Structural abnormalities in hippocampal volume and shape are found in several common neuropsychiatric disorders. To identify the genetic underpinnings of hippocampal structure here we perform a genome-wide association study (GWAS) of 33,536 individuals and discover six independent loci significantly associated with hippocampal volume, four of them novel. Of the novel loci, three lie within genes (ASTN2, DPP4 and MAST4) and one is found 200 kb upstream of SHH. A hippocampal subfield analysis shows that a locus within the MSRB3 gene shows evidence of a localized effect along the dentate gyrus, subiculum, CA1 and fissure. Further, we show that genetic variants associated with decreased hippocampal volume are also associated with increased risk for Alzheimer's disease (r g =-0.155). Our findings suggest novel biological pathways through which human genetic variation influences hippocampal volume and risk for neuropsychiatric illness.

  8. A note on stereological estimation of the volume-weighted second moment of particle volume

    DEFF Research Database (Denmark)

    Jensen, E B; Sørensen, Flemming Brandt

    1991-01-01

    It is shown that for a variety of biological particle shapes, the volume-weighted second moment of particle volume can be estimated stereologically using only the areas of particle transects, which can be estimated manually by point-counting....

  9. Stochastic and sensitivity analysis of shape error of inflatable antenna reflectors

    Science.gov (United States)

    San, Bingbing; Yang, Qingshan; Yin, Liwei

    2017-03-01

    Inflatable antennas are promising candidates to realize future satellite communications and space observations since they are lightweight, low-cost and small-packaged-volume. However, due to their high flexibility, inflatable reflectors are difficult to manufacture accurately, which may result in undesirable shape errors, and thus affect their performance negatively. In this paper, the stochastic characteristics of shape errors induced during manufacturing process are investigated using Latin hypercube sampling coupled with manufacture simulations. Four main random error sources are involved, including errors in membrane thickness, errors in elastic modulus of membrane, boundary deviations and pressure variations. Using regression and correlation analysis, a global sensitivity study is conducted to rank the importance of these error sources. This global sensitivity analysis is novel in that it can take into account the random variation and the interaction between error sources. Analyses are parametrically carried out with various focal-length-to-diameter ratios (F/D) and aperture sizes (D) of reflectors to investigate their effects on significance ranking of error sources. The research reveals that RMS (Root Mean Square) of shape error is a random quantity with an exponent probability distribution and features great dispersion; with the increase of F/D and D, both mean value and standard deviation of shape errors are increased; in the proposed range, the significance ranking of error sources is independent of F/D and D; boundary deviation imposes the greatest effect with a much higher weight than the others; pressure variation ranks the second; error in thickness and elastic modulus of membrane ranks the last with very close sensitivities to pressure variation. Finally, suggestions are given for the control of the shape accuracy of reflectors and allowable values of error sources are proposed from the perspective of reliability.

  10. Shape oscillation of bubbles in the acoustic field

    OpenAIRE

    Matsumoto, Keishi; Ueno, Ichiro

    2009-01-01

    The authors introduce dynamics of multiple air bubbles exposed to ultrasonic wave while ascending in water in the present fluid dynamics video. The authors pay attention to the shape oscillation and the transition from the volume to the shape oscillations of the bubble. Correlation between the bubble size and the mechanism of the excitation of the shape oscillation is introduced.

  11. A note on stereological estimation of the volume-weighted second moment of particle volume

    DEFF Research Database (Denmark)

    Jensen, E B; Sørensen, Flemming Brandt

    1991-01-01

    It is shown that for a variety of biological particle shapes, the volume-weighted second moment of particle volume can be estimated stereologically using only the areas of particle transects, which can be estimated manually by point-counting.......It is shown that for a variety of biological particle shapes, the volume-weighted second moment of particle volume can be estimated stereologically using only the areas of particle transects, which can be estimated manually by point-counting....

  12. On quadratic variation of martingales

    Indian Academy of Sciences (India)

    ... Year Meetings · Discussion Meetings · Public Lectures · Lecture Workshops · Refresher Courses · Symposia · Live Streaming. Home; Journals; Proceedings – Mathematical Sciences; Volume 124; Issue 3. On Quadratic Variation of Martingales. Rajeeva L Karandikar B V Rao. Volume 124 Issue 3 August 2014 pp 457-469 ...

  13. Shape memory polymers

    Science.gov (United States)

    Wilson, Thomas S.; Bearinger, Jane P.

    2015-06-09

    New shape memory polymer compositions, methods for synthesizing new shape memory polymers, and apparatus comprising an actuator and a shape memory polymer wherein the shape memory polymer comprises at least a portion of the actuator. A shape memory polymer comprising a polymer composition which physically forms a network structure wherein the polymer composition has shape-memory behavior and can be formed into a permanent primary shape, re-formed into a stable secondary shape, and controllably actuated to recover the permanent primary shape. Polymers have optimal aliphatic network structures due to minimization of dangling chains by using monomers that are symmetrical and that have matching amine and hydroxyl groups providing polymers and polymer foams with clarity, tight (narrow temperature range) single transitions, and high shape recovery and recovery force that are especially useful for implanting in the human body.

  14. Shape memory polymers

    Energy Technology Data Exchange (ETDEWEB)

    Wilson, Thomas S.; Bearinger, Jane P.

    2017-08-29

    New shape memory polymer compositions, methods for synthesizing new shape memory polymers, and apparatus comprising an actuator and a shape memory polymer wherein the shape memory polymer comprises at least a portion of the actuator. A shape memory polymer comprising a polymer composition which physically forms a network structure wherein the polymer composition has shape-memory behavior and can be formed into a permanent primary shape, re-formed into a stable secondary shape, and controllably actuated to recover the permanent primary shape. Polymers have optimal aliphatic network structures due to minimization of dangling chains by using monomers that are symmetrical and that have matching amine and hydroxl groups providing polymers and polymer foams with clarity, tight (narrow temperature range) single transitions, and high shape recovery and recovery force that are especially useful for implanting in the human body.

  15. Effects of pre-strain and Nb content on transformation temperatures in Ti-Ni-Nb shape memory alloy

    Energy Technology Data Exchange (ETDEWEB)

    Sakuma, T. [Central Research Inst. of Electric Power Industry, Komae (Japan); Mihara, Y. [Graduate School, Univ. of Electro-Communications, Chofu (Japan); Ochi, Y. [Univ. of Electro-Communications, Chofu (Japan); Ozawa, M. [NEC Tokin, Co., Sendai (Japan); Okita, K. [Graduate School, Ehime Univ., Matsuyama (Japan); Okabe, N. [Ehime Univ., Matsuyama (Japan)

    2005-07-01

    Ti-Ni-Nb shape memory alloy has a wide transformation hysteresis, and has been used as coupling devices and so on. However systematic researches of the influence of the amount of Nb addition on transformation temperatures are few. The purpose of this work is to clarify the influences of pre-strain and Nb content on transformation temperatures in Ti-Ni-Nb shape memory alloys. The specimens were Ti-Ni-Nb alloys (Ni/Ti=1.0, Nb=0-15at%), annealed at 1223 K for 0.3 ks. The variation of transformation temperatures with pre-strain and Nb content were investigated experimentally. The variation of A{sub s}, M{sub s} and transformation temperature hysteresis with pre-strain and Nb content will be discussed in relation to the elastic strain energy and the volume fraction of slip-deformed martensite. (orig.)

  16. New trends in shape optimization

    CERN Document Server

    Leugering, Günter

    2015-01-01

    This volume reflects “New Trends in Shape Optimization” and is based on a workshop of the same name organized at the Friedrich-Alexander University Erlangen-Nürnberg in September 2013. During the workshop senior mathematicians and young scientists alike presented their latest findings. The format of the meeting allowed fruitful discussions on challenging open problems, and triggered a number of new and spontaneous collaborations. As such, the idea was born to produce this book, each chapter of which was written by a workshop participant, often with a collaborator. The content of the individual chapters ranges from survey papers to original articles; some focus on the topics discussed at the Workshop, while others involve arguments outside its scope but which are no less relevant for the field today. As such, the book offers readers a balanced introduction to the emerging field of shape optimization.

  17. Ovarian volume throughout life

    DEFF Research Database (Denmark)

    Kelsey, Thomas W; Dodwell, Sarah K; Wilkinson, A Graham

    2013-01-01

    to about 2.8 mL (95% CI 2.7-2.9 mL) at the menopause and smaller volumes thereafter. Our model allows us to generate normal values and ranges for ovarian volume throughout life. This is the first validated normative model of ovarian volume from conception to old age; it will be of use in the diagnosis...... cancer. To date there is no normative model of ovarian volume throughout life. By searching the published literature for ovarian volume in healthy females, and using our own data from multiple sources (combined n=59,994) we have generated and robustly validated the first model of ovarian volume from...... conception to 82 years of age. This model shows that 69% of the variation in ovarian volume is due to age alone. We have shown that in the average case ovarian volume rises from 0.7 mL (95% CI 0.4-1.1 mL) at 2 years of age to a peak of 7.7 mL (95% CI 6.5-9.2 mL) at 20 years of age with a subsequent decline...

  18. Modeling nuclear volume isotope effects in crystals

    Science.gov (United States)

    Schauble, Edwin A.

    2013-01-01

    Mass-independent isotope fractionations driven by differences in volumes and shapes of nuclei (the field shift effect) are known in several elements and are likely to be found in more. All-electron relativistic electronic structure calculations can predict this effect but at present are computationally intensive and limited to modeling small gas phase molecules and clusters. Density functional theory, using the projector augmented wave method (DFT-PAW), has advantages in greater speed and compatibility with a three-dimensional periodic boundary condition while preserving information about the effects of chemistry on electron densities within nuclei. These electron density variations determine the volume component of the field shift effect. In this study, DFT-PAW calculations are calibrated against all-electron, relativistic Dirac–Hartree–Fock, and coupled-cluster with single, double (triple) excitation methods for estimating nuclear volume isotope effects. DFT-PAW calculations accurately reproduce changes in electron densities within nuclei in typical molecules, when PAW datasets constructed with finite nuclei are used. Nuclear volume contributions to vapor–crystal isotope fractionation are calculated for elemental cadmium and mercury, showing good agreement with experiments. The nuclear-volume component of mercury and cadmium isotope fractionations between atomic vapor and montroydite (HgO), cinnabar (HgS), calomel (Hg2Cl2), monteponite (CdO), and the CdS polymorphs hawleyite and greenockite are calculated, indicating preferential incorporation of neutron-rich isotopes in more oxidized, ionically bonded phases. Finally, field shift energies are related to Mössbauer isomer shifts, and equilibrium mass-independent fractionations for several tin-bearing crystals are calculated from 119Sn spectra. Isomer shift data should simplify calculations of mass-independent isotope fractionations in other elements with Mössbauer isotopes, such as platinum and uranium

  19. Modeling nuclear volume isotope effects in crystals.

    Science.gov (United States)

    Schauble, Edwin A

    2013-10-29

    Mass-independent isotope fractionations driven by differences in volumes and shapes of nuclei (the field shift effect) are known in several elements and are likely to be found in more. All-electron relativistic electronic structure calculations can predict this effect but at present are computationally intensive and limited to modeling small gas phase molecules and clusters. Density functional theory, using the projector augmented wave method (DFT-PAW), has advantages in greater speed and compatibility with a three-dimensional periodic boundary condition while preserving information about the effects of chemistry on electron densities within nuclei. These electron density variations determine the volume component of the field shift effect. In this study, DFT-PAW calculations are calibrated against all-electron, relativistic Dirac-Hartree-Fock, and coupled-cluster with single, double (triple) excitation methods for estimating nuclear volume isotope effects. DFT-PAW calculations accurately reproduce changes in electron densities within nuclei in typical molecules, when PAW datasets constructed with finite nuclei are used. Nuclear volume contributions to vapor-crystal isotope fractionation are calculated for elemental cadmium and mercury, showing good agreement with experiments. The nuclear-volume component of mercury and cadmium isotope fractionations between atomic vapor and montroydite (HgO), cinnabar (HgS), calomel (Hg2Cl2), monteponite (CdO), and the CdS polymorphs hawleyite and greenockite are calculated, indicating preferential incorporation of neutron-rich isotopes in more oxidized, ionically bonded phases. Finally, field shift energies are related to Mössbauer isomer shifts, and equilibrium mass-independent fractionations for several tin-bearing crystals are calculated from (119)Sn spectra. Isomer shift data should simplify calculations of mass-independent isotope fractionations in other elements with Mössbauer isotopes, such as platinum and uranium.

  20. Shaping Robust System through Evolution

    CERN Document Server

    Kaneko, Kunihiko

    2008-01-01

    Biological functions are generated as a result of developmental dynamics that form phenotypes governed by genotypes. The dynamical system for development is shaped through genetic evolution following natural selection based on the fitness of the phenotype. Here we study how this dynamical system is robust to noise during development and to genetic change by mutation. We adopt a simplified transcription regulation network model to govern gene expression, which gives a fitness function. Through simulations of the network that undergoes mutation and selection, we show that a certain level of noise in gene expression is required for the network to acquire both types of robustness. The results reveal how the noise that cells encounter during development shapes any network's robustness, not only to noise but also to mutations. We also establish a relationship between developmental and mutational robustness through phenotypic variances caused by genetic variation and epigenetic noise. A universal relationship betwee...

  1. Self-erecting shapes

    Energy Technology Data Exchange (ETDEWEB)

    Reading, Matthew W.

    2017-07-04

    Technologies for making self-erecting structures are described herein. An exemplary self-erecting structure comprises a plurality of shape-memory members that connect two or more hub components. When forces are applied to the self-erecting structure, the shape-memory members can deform, and when the forces are removed the shape-memory members can return to their original pre-deformation shape, allowing the self-erecting structure to return to its own original shape under its own power. A shape of the self-erecting structure depends on a spatial orientation of the hub components, and a relative orientation of the shape-memory members, which in turn depends on an orientation of joining of the shape-memory members with the hub components.

  2. Shaped Recess Flow Control

    Science.gov (United States)

    Shyam, Vikram (Inventor); Poinsatte, Philip (Inventor); Thurman, Douglas (Inventor)

    2017-01-01

    One or more embodiments of techniques or systems for shaped recess flow control are provided herein. A shaped recess or cavity can be formed on a surface associated with fluid flow. The shaped recess can be configured to create or induce fluid effects, temperature effects, or shedding effects that interact with a free stream or other structures. The shaped recess can be formed at an angle to a free stream flow and may be substantially "V" shaped. The shaped recess can be coupled with a cooling channel, for example. The shaped recess can be upstream or downstream from a cooling channel and aligned in a variety of manners. Due to the fluid effects, shedding effects, and temperature effects created by a shaped recess, lift-off or separation of cooling jets of cooling channels can be mitigated, thereby enhancing film cooling effectiveness.

  3. The Hue of Shapes

    Science.gov (United States)

    Albertazzi, Liliana; Da Pos, Osvaldo; Canal, Luisa; Micciolo, Rocco; Malfatti, Michela; Vescovi, Massimo

    2013-01-01

    This article presents an experimental study on the naturally biased association between shape and color. For each basic geometric shape studied, participants were asked to indicate the color perceived as most closely related to it, choosing from the Natural Color System Hue Circle. Results show that the choices of color for each shape were not…

  4. Building with shapes

    CERN Document Server

    Mooney, Carla

    2014-01-01

    There are shapes everywhere you look. You can put shapes together or build with them. What can you build with three circles? In this title, students will explore and understand that certain attributes define what a shape is called. This title will allow students to identify the main purpose of a text, including what the author wants to answer, explain, or describe.

  5. Alpha Shapes and Proteins

    DEFF Research Database (Denmark)

    Winter, Pawel; Sterner, Henrik; Sterner, Peter

    2009-01-01

    We provide a unified description of (weighted) alpha shapes, beta shapes and the corresponding simplicialcomplexes. We discuss their applicability to various protein-related problems. We also discuss filtrations of alpha shapes and touch upon related persistence issues.We claim that the full...... potential of alpha-shapes and related geometrical constructs in protein-related problems yet remains to be realized and verified. We suggest parallel algorithms for (weighted) alpha shapes, and we argue that future use of filtrations and kinetic variants for larger proteins will need such implementation....

  6. Transforming shape in design

    DEFF Research Database (Denmark)

    Prats, Miquel; Lim, Sungwoo; Jowers, Iestyn

    2009-01-01

    This paper is concerned with how design shapes are generated and explored by means of sketching. It presents research into the way designers transform shapes from one state to another using sketch representations. An experimental investigation of the sketching processes of designers is presented....... Connections between sketches are defined in terms of shape transformations and described according to shape rules. These rules provide a formal description of the shape exploration process and develop understanding of the mechanics of sketching in design. The paper concludes by discussing the important...

  7. Mapping morphological shape as a high-dimensional functional curve.

    Science.gov (United States)

    Fu, Guifang; Huang, Mian; Bo, Wenhao; Hao, Han; Wu, Rongling

    2017-01-06

    Detecting how genes regulate biological shape has become a multidisciplinary research interest because of its wide application in many disciplines. Despite its fundamental importance, the challenges of accurately extracting information from an image, statistically modeling the high-dimensional shape and meticulously locating shape quantitative trait loci (QTL) affect the progress of this research. In this article, we propose a novel integrated framework that incorporates shape analysis, statistical curve modeling and genetic mapping to detect significant QTLs regulating variation of biological shape traits. After quantifying morphological shape via a radius centroid contour approach, each shape, as a phenotype, was characterized as a high-dimensional curve, varying as angle θ runs clockwise with the first point starting from angle zero. We then modeled the dynamic trajectories of three mean curves and variation patterns as functions of θ Our framework led to the detection of a few significant QTLs regulating the variation of leaf shape collected from a natural population of poplar, Populus szechuanica var tibetica This population, distributed at altitudes 2000-4500 m above sea level, is an evolutionarily important plant species. This is the first work in the quantitative genetic shape mapping area that emphasizes a sense of 'function' instead of decomposing the shape into a few discrete principal components, as the majority of shape studies do. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  8. A single basis for developmental buffering of Drosophila wing shape.

    Directory of Open Access Journals (Sweden)

    Casper J Breuker

    2006-12-01

    Full Text Available The nature of developmental buffering processes has been debated extensively, based on both theoretical reasoning and empirical studies. In particular, controversy has focused on the question of whether distinct processes are responsible for canalization, the buffering against environmental or genetic variation, and for developmental stability, the buffering against random variation intrinsic in developmental processes. Here, we address this question for the size and shape of Drosophila melanogaster wings in an experimental design with extensively replicated and fully controlled genotypes. The amounts of variation among individuals and of fluctuating asymmetry differ markedly among genotypes, demonstrating a clear genetic basis for size and shape variability. For wing shape, there is a high correlation between the amounts of variation among individuals and fluctuating asymmetry, which indicates a correspondence between the two types of buffering. Likewise, the multivariate patterns of shape variation among individuals and of fluctuating asymmetry show a close association. For wing size, however, the amounts of individual variation and fluctuating asymmetry are not correlated. There was a significant link between the amounts of variation between wing size and shape, more so for fluctuating asymmetry than for variation among individuals. Overall, these experiments indicate a considerable degree of shared control of individual variation and fluctuating asymmetry, although it appears to differ between traits.

  9. Billiards in L-shaped tables with barriers

    DEFF Research Database (Denmark)

    Bainbridge, Matthew

    2010-01-01

    We compute the volumes of the eigenform loci in the moduli space of genus-two Abelian differentials. From this, we obtain asymptotic formulas for counting closed billiards paths in certain L-shaped polygons with barriers.......We compute the volumes of the eigenform loci in the moduli space of genus-two Abelian differentials. From this, we obtain asymptotic formulas for counting closed billiards paths in certain L-shaped polygons with barriers....

  10. The Concave Shape of the Forced Expiratory Flow-Volume Curve in 3 Seconds Is a Practical Surrogate of FEV1/FVC for the Diagnosis of Airway Limitation in Inadequate Spirometry.

    Science.gov (United States)

    Li, Hao; Liu, Chunhong; Zhang, Yi; Xiao, Wei

    2017-03-01

    Spirometry is important for the differential diagnosis of dyspnea. However, some patients cannot exhale for ≥6 s to achieve the American Thoracic Society/European Respiratory Society criteria. The aim of this study was to demonstrate the reliability of a new parameter that quantifies the degree of concavity in the first 3 s to define airway limitation as a surrogate for the FEV 1 /FVC. Four hundred spirometry test results were selected through complete random sampling. The new parameter, termed the AUC 3 /AT 3 , was calculated as the area under the descending limb of the expiratory flow-volume curve before the end of the first 3 s (AUC 3 ) divided by the area of the triangle before the end of the first 3 s (AT 3 ). The AUC 3 /AT 3 was compared with the FEV 1 /FVC using Pearson's correlation analysis. The level of agreement between the AUC 3 /AT 3 and the FEV 1 /FVC in the detection of airway obstruction was analyzed using the kappa statistic. We also compared the diagnostic accuracy of the new index with that of the FEV 1 /forced expiratory volume in the first 3 s (FEV 3 ). There was a strong correlation (r = 0.88, P < .001) between the AUC 3 /AT 3 and the FEV 1 /FVC. There was also strong agreement between the AUC 3 /AT 3 and the FEV 1 /FVC in the detection of obstruction with kappa indices of 0.72 (Global Initiative for Chronic Obstructive Lung Disease [GOLD] criterion) and 0.67 (lower limit of normal criterion), and these values were greater than those obtained for the FEV 1 /FEV 3 . The AUC 3 /AT 3 also exhibited acceptable sensitivity, specificity, positive predictive value, and negative predictive value. The diagnostic accuracies of the AUC 3 /AT 3 were 86.3% (GOLD criterion) and 83.8% (lower limit of normal criterion), which were greater than the 76.0 and 74.0% obtained for the FEV 1 /FEV 3 , respectively. The AUC 3 /AT 3 can be utilized as a surrogate parameter for the FEV 1 /FVC when patients cannot complete a 6-s expiratory effort. Additionally, the

  11. Effect of resin-composite filler particle size and shape on shrinkage-stress.

    Science.gov (United States)

    Satterthwaite, Julian D; Maisuria, Amit; Vogel, Karin; Watts, David C

    2012-06-01

    The aim of this study was to investigate the effect of variations in filler particle size and shape on the polymerization shrinkage-stress kinetics of resin-composites. A model series of 12 VLC resin-composites were studied. The particulate dispersed phase volume fraction was 56.7%: these filler particles were systematically graded in size, and further were either spherical or irregular. A Bioman instrument (cantilever beam method) was employed to determine the shrinkage-stress kinetics following 40s irradiation (600 mW/cm(2)) at 23°C (n=3). All data were captured for 60 min and the final shrinkage-stress calculated. Shrinkage-stress varied between 3.86 MPa (SD 0.14) for S3 (spherical filler particles of 500 nm) and 8.44 MPa (SD 0.41) for I1 (irregular filler particles of 450 nm). The shrinkage-stress values were generally lower for those composites with spherical filler particles than those with irregular filler particles. The differences in shrinkage-stress with filler particle size and shape were statistically significant (pparticles exhibit lower shrinkage-stress values compared to those with irregular filler particles. Shrinkage-stress and shrinkage-stress rate vary in a complex manner with variations in the size of the dispersed phase particles: a hypothesized explanation for the effect of filler particle size and shape is presented. Copyright © 2012 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

  12. Small-Volume Injections: Evaluation of Volume Administration Deviation From Intended Injection Volumes.

    Science.gov (United States)

    Muffly, Matthew K; Chen, Michael I; Claure, Rebecca E; Drover, David R; Efron, Bradley; Fitch, William L; Hammer, Gregory B

    2017-10-01

    regression model. Analysis of variance was used to determine whether the absolute log proportional error differed by the intended injection volume. Interindividual and intraindividual deviation from the intended injection volume was also characterized. As the intended injection volumes decreased, the absolute log proportional injection volume error increased (analysis of variance, P injection volumes between physicians and pediatric PACU nurses; however, the difference in absolute bias was significantly higher for nurses with a 2-sided significance of P = .03. Clinically significant dose variation occurs when injecting volumes ≤0.5 mL. Administering small volumes of medications may result in unintended medication administration errors.

  13. Cylindrical-shaped nanotube field effect transistor

    KAUST Repository

    Hussain, Muhammad Mustafa

    2015-12-29

    A cylindrical-shaped nanotube FET may be manufactured on silicon (Si) substrates as a ring etched into a gate stack and filled with semiconductor material. An inner gate electrode couples to a region of the gate stack inside the inner circumference of the ring. An outer gate electrode couples to a region of the gate stack outside the outer circumference of the ring. The multi-gate cylindrical-shaped nanotube FET operates in volume inversion for ring widths below 15 nanometers. The cylindrical-shaped nanotube FET demonstrates better short channel effect (SCE) mitigation and higher performance (I.sub.on/I.sub.off) than conventional transistor devices. The cylindrical-shaped nanotube FET may also be manufactured with higher yields and cheaper costs than conventional transistors.

  14. The comparative psychophysics of complex shape perception.

    Science.gov (United States)

    Smith, J David; Redford, Joshua S; Haas, Sarah M

    2009-11-01

    The authors compared the complex shape perception of humans and monkeys. Members of both species participated in a Same-Different paradigm in which they judged the similarity of shape pairs that could be variations of the same underlying prototype. For both species, similarity gradients were found to be steep going out from the transformational center of psychological space. In contrast, similarity gradients were found to be flat going from the periphery in toward the center of psychological space. These results show that there are important common principles in the shape-perception and shape-comparison processes of humans and monkeys. The same general organization of psychological space is obtained. The same quantifiable metric of psychological distance is applied. Established methods for creating controlled shape variation have the same effect on both species' similarity judgments. The member of the to-be-judged pair of shapes that is peripheral in psychological space controls the strength of the perceived similarity of the pair. The results have broader implications for the comparative study of perception and categorization.

  15. Perspectives in shape analysis

    CERN Document Server

    Bruckstein, Alfred; Maragos, Petros; Wuhrer, Stefanie

    2016-01-01

    This book presents recent advances in the field of shape analysis. Written by experts in the fields of continuous-scale shape analysis, discrete shape analysis and sparsity, and numerical computing who hail from different communities, it provides a unique view of the topic from a broad range of perspectives. Over the last decade, it has become increasingly affordable to digitize shape information at high resolution. Yet analyzing and processing this data remains challenging because of the large amount of data involved, and because modern applications such as human-computer interaction require real-time processing. Meeting these challenges requires interdisciplinary approaches that combine concepts from a variety of research areas, including numerical computing, differential geometry, deformable shape modeling, sparse data representation, and machine learning. On the algorithmic side, many shape analysis tasks are modeled using partial differential equations, which can be solved using tools from the field of n...

  16. Analysis of acoustic resonator with shape deformation using finite ...

    Indian Academy of Sciences (India)

    An acoustic resonator with shape deformation has been analysed using the finite element method. The shape deformation issuch that the volume of the resonator remains constant. The effect of deformation on the resonant frequencies is studied. Deformation splits the degenerate frequencies.

  17. Quantitative analysis of fetal facial morphology using 3D ultrasound and statistical shape modeling: a feasibility study.

    Science.gov (United States)

    Dall'Asta, Andrea; Schievano, Silvia; Bruse, Jan L; Paramasivam, Gowrishankar; Kaihura, Christine Tita; Dunaway, David; Lees, Christoph C

    2017-07-01

    The antenatal detection of facial dysmorphism using 3-dimensional ultrasound may raise the suspicion of an underlying genetic condition but infrequently leads to a definitive antenatal diagnosis. Despite advances in array and noninvasive prenatal testing, not all genetic conditions can be ascertained from such testing. The aim of this study was to investigate the feasibility of quantitative assessment of fetal face features using prenatal 3-dimensional ultrasound volumes and statistical shape modeling. STUDY DESIGN: Thirteen normal and 7 abnormal stored 3-dimensional ultrasound fetal face volumes were analyzed, at a median gestation of 29+4 weeks (25+0 to 36+1). The 20 3-dimensional surface meshes generated were aligned and served as input for a statistical shape model, which computed the mean 3-dimensional face shape and 3-dimensional shape variations using principal component analysis. Ten shape modes explained more than 90% of the total shape variability in the population. While the first mode accounted for overall size differences, the second highlighted shape feature changes from an overall proportionate toward a more asymmetric face shape with a wide prominent forehead and an undersized, posteriorly positioned chin. Analysis of the Mahalanobis distance in principal component analysis shape space suggested differences between normal and abnormal fetuses (median and interquartile range distance values, 7.31 ± 5.54 for the normal group vs 13.27 ± 9.82 for the abnormal group) (P = .056). This feasibility study demonstrates that objective characterization and quantification of fetal facial morphology is possible from 3-dimensional ultrasound. This technique has the potential to assist in utero diagnosis, particularly of rare conditions in which facial dysmorphology is a feature. Copyright © 2017 Elsevier Inc. All rights reserved.

  18. Novel genetic loci associated with hippocampal volume

    NARCIS (Netherlands)

    D.P. Hibar (Derrek); H.H.H. Adams (Hieab); N. Jahanshad (Neda); G. Chauhan (Ganesh); J.L. Stein; E. Hofer (Edith); M.E. Rentería (Miguel); J.C. Bis (Joshua); A. Arias-Vásquez (Alejandro); Ikram, M.K. (M. Kamran); S. Desrivières (Sylvane); M.W. Vernooij (Meike); L. Abramovic (Lucija); S. Alhusaini (Saud); N. Amin (Najaf); M. Andersson (Micael); K. Arfanakis (Konstantinos); B. Aribisala (Benjamin); N.J. Armstrong (Nicola J.); L. Athanasiu (Lavinia); T. Axelsson (Tomas); A.H. Beecham (Ashley); A. Beiser (Alexa); M. Bernard (Manon); S.H. Blanton (Susan H.); M.M. Bohlken (Marc M.); M.P.M. Boks (Marco); L.B.C. Bralten (Linda); A.M. Brickman (Adam M.); Carmichael, O. (Owen); M.M. Chakravarty (M. Mallar); Q. Chen (Qiang); C.R.K. Ching (Christopher); V. Chouraki (Vincent); G. Cuellar-Partida (Gabriel); F. Crivello (Fabrice); A. den Braber (Anouk); Doan, N.T. (Nhat Trung); S.M. Ehrlich (Stefan); S. Giddaluru (Sudheer); A.L. Goldman (Aaron L.); R.F. Gottesman (Rebecca); O. Grimm (Oliver); M.D. Griswold (Michael); T. Guadalupe (Tulio); Gutman, B.A. (Boris A.); J. Hass (Johanna); U.K. Haukvik (Unn); D. Hoehn (David); A.J. Holmes (Avram); M. Hoogman (Martine); D. Janowitz (Deborah); T. Jia (Tianye); Jørgensen, K.N. (Kjetil N.); N. Karbalai (Nazanin); D. Kasperaviciute (Dalia); S. Kim (Shinseog); M. Klein (Marieke); B. Kraemer (Bernd); P.H. Lee (Phil); D.C. Liewald (David C.); L.M. Lopez (Lorna); M. Luciano (Michelle); C. MacAre (Christine); Marquand, A.F. (Andre F.); M. Matarin (Mar); R. Mather; M. Mattheisen (Manuel); McKay, D.R. (David R.); Milaneschi, Y. (Yuri); S. Muñoz Maniega (Susana); K. Nho (Kwangsik); A.C. Nugent (Allison); P. Nyquist (Paul); Loohuis, L.M.O. (Loes M. Olde); J. Oosterlaan (Jaap); M. Papmeyer (Martina); Pirpamer, L. (Lukas); B. Pütz (Benno); A. Ramasamy (Adaikalavan); Richards, J.S. (Jennifer S.); S.L. Risacher (Shannon); R. Roiz-Santiañez (Roberto); N. Rommelse (Nanda); S. Ropele (Stefan); E.J. Rose (Emma); N.A. Royle (Natalie); T. Rundek (Tatjana); P.G. Sämann (Philipp); Saremi, A. (Arvin); C.L. Satizabal (Claudia L.); L. Schmaal (Lianne); N.J. Schork (Nicholas); Shen, L. (Li); J. Shin (Jean); Shumskaya, E. (Elena); A.V. Smith (Albert Vernon); R. Sprooten (Roy); V.M. Strike (Vanessa); A. Teumer (Alexander); D. Tordesillas-Gutierrez (Diana); R. Toro (Roberto); D. Trabzuni (Danyah); S. Trompet (Stella); D. Vaidya (Dhananjay); J. van der Grond (Jeroen); S.J. van der Lee (Sven); Van Der Meer, D. (Dennis); M.M.J. Van Donkelaar (Marjolein M. J.); K.R. van Eijk (Kristel); T.G.M. van Erp (Theo G.); Van Rooij, D. (Daan); E. Walton (Esther); L.T. Westlye (Lars); C.D. Whelan (Christopher); B.G. Windham (B Gwen); A.M. Winkler (Anderson); K. Wittfeld (Katharina); G. Woldehawariat (Girma); A. Björnsson (Asgeir); Wolfers, T. (Thomas); L.R. Yanek (Lisa); Yang, J. (Jingyun); A.P. Zijdenbos; M.P. Zwiers (Marcel); I. Agartz (Ingrid); L. Almasy (Laura); D.J. Ames (David); Amouyel, P. (Philippe); O.A. Andreassen (Ole); S. Arepalli (Sampath); A.A. Assareh; S. Barral (Sandra); M.E. Bastin (Mark); Becker, D.M. (Diane M.); J.T. Becker (James); D.A. Bennett (David A.); J. Blangero (John); H. van Bokhoven (Hans); D.I. Boomsma (Dorret); H. Brodaty (Henry); R.M. Brouwer (Rachel); H.G. Brunner; M. Buckner; J.K. Buitelaar (Jan); K. Bulayeva (Kazima); W. Cahn (Wiepke); V.D. Calhoun Vince D. (V.); D.M. Cannon (Dara); G. Cavalleri (Gianpiero); Cheng, C.-Y. (Ching-Yu); S. Cichon (Sven); M.R. Cookson (Mark); A. Corvin (Aiden); B. Crespo-Facorro (Benedicto); J.E. Curran (Joanne); M. Czisch (Michael); A.M. Dale (Anders); G.E. Davies (Gareth); A.J. de Craen (Anton); E.J.C. de Geus (Eco); P.L. de Jager (Philip); G.I. de Zubicaray (Greig); I.J. Deary (Ian J.); S. Debette (Stéphanie); C. DeCarli (Charles); N. Delanty; C. Depondt (Chantal); A.L. DeStefano (Anita); A. Dillman (Allissa); S. Djurovic (Srdjan); D.J. Donohoe (Dennis); D.A. Drevets (Douglas); Duggirala, R. (Ravi); M.D. Dyer (Matthew); C. Enzinger (Christian); S. Erk; T. Espeseth (Thomas); Fedko, I.O. (Iryna O.); Fernández, G. (Guillén); L. Ferrucci (Luigi); S.E. Fisher (Simon); D. Fleischman (Debra); I. Ford (Ian); M. Fornage (Myriam); T. Foroud (Tatiana); P.T. Fox (Peter); C. Francks (Clyde); Fukunaga, M. (Masaki); Gibbs, J.R. (J. Raphael); D.C. Glahn (David); R.L. Gollub (Randy); H.H.H. Göring (Harald H.); R.C. Green (Robert C.); O. Gruber (Oliver); V. Gudnason (Vilmundur); S. Guelfi (Sebastian); Håberg, A.K. (Asta K.); N.K. Hansell (Narelle); J. Hardy (John); C.A. Hartman (C.); Hashimoto, R. (Ryota); K. Hegenscheid (Katrin); J. Heinz (Judith); S. Le Hellard (Stephanie); D.G. Hernandez (Dena); D.J. Heslenfeld (Dirk); Ho, B.-C. (Beng-Choon); P.J. Hoekstra (Pieter); W. Hoffmann (Wolfgang); A. Hofman (Albert); F. Holsboer (Florian); G. Homuth (Georg); N. Hosten (Norbert); J.J. Hottenga (Jouke Jan); M.J. Huentelman (Matthew); H.H. Pol; Ikeda, M. (Masashi); Jack, C.R. (Clifford R.); S. Jenkinson (Sarah); R. Johnson (Robert); Jönsson, E.G. (Erik G.); J.W. Jukema; R. Kahn (René); Kanai, R. (Ryota); I. Kloszewska (Iwona); Knopman, D.S. (David S.); P. Kochunov (Peter); Kwok, J.B. (John B.); S. Lawrie (Stephen); H. Lemaître (Herve); X. Liu (Xinmin); D.L. Longo (Dan L.); O.L. Lopez (Oscar L.); S. Lovestone (Simon); Martinez, O. (Oliver); J.-L. Martinot (Jean-Luc); V.S. Mattay (Venkata S.); McDonald, C. (Colm); A.M. McIntosh (Andrew); McMahon, F.J. (Francis J.); McMahon, K.L. (Katie L.); P. Mecocci (Patrizia); I. Melle (Ingrid); Meyer-Lindenberg, A. (Andreas); S. Mohnke (Sebastian); Montgomery, G.W. (Grant W.); D.W. Morris (Derek W); T.H. Mosley (Thomas H.); T.W. Mühleisen (Thomas); B. Müller-Myhsok (B.); M.A. Nalls (Michael); M. Nauck (Matthias); T.E. Nichols (Thomas); W.J. Niessen (Wiro); M.M. Nöthen (Markus); L. Nyberg (Lars); Ohi, K. (Kazutaka); R.L. Olvera (Rene); R.A. Ophoff (Roel); M. Pandolfo (Massimo); T. Paus (Tomas); Z. Pausova (Zdenka); B.W.J.H. Penninx (Brenda); Pike, G.B. (G. Bruce); S.G. Potkin (Steven); B.M. Psaty (Bruce); S. Reppermund; M. Rietschel (Marcella); J.L. Roffman (Joshua); N. Seiferth (Nina); J.I. Rotter (Jerome I.); M. Ryten (Mina); Sacco, R.L. (Ralph L.); P.S. Sachdev (Perminder); A.J. Saykin (Andrew); R. Schmidt (Reinhold); Schmidt, H. (Helena); C.J. Schofield (Christopher); Sigursson, S. (Sigurdur); Simmons, A. (Andrew); A. Singleton (Andrew); S.M. Sisodiya (Sanjay); Smith, C. (Colin); J.W. Smoller; H. Soininen (H.); V.M. Steen (Vidar); D.J. Stott (David J.); J. Sussmann (Jessika); A. Thalamuthu (Anbupalam); A.W. Toga (Arthur W.); B. Traynor (Bryan); J.C. Troncoso (Juan); M. Tsolaki (Magda); C. Tzourio (Christophe); A.G. Uitterlinden (André); Hernández, M.C.V. (Maria C. Valdés); M.P. van der Brug (Marcel); A. van der Lugt (Aad); N.J. van der Wee (Nic); N.E.M. van Haren (Neeltje E.); D. van 't Ent (Dennis); M.J.D. van Tol (Marie-José); B.N. Vardarajan (Badri); B. Vellas (Bruno); D.J. Veltman (Dick); H. Völzke (Henry); H.J. Walter (Henrik); J. Wardlaw (Joanna); A.M.J. Wassink (Annemarie); M.E. Weale (Michael); Weinberger, D.R. (Daniel R.); Weiner, M.W. (Michael W.); Wen, W. (Wei); E. Westman (Eric); T.J.H. White (Tonya); Wong, T.Y. (Tien Y.); Wright, C.B. (Clinton B.); R.H. Zielke (Ronald H.); A.B. Zonderman; N.G. Martin (Nicholas); C.M. van Duijn (Cornelia); M.J. Wright (Margaret); W.T. Longstreth Jr; G. Schumann (Gunter); H.J. Grabe (Hans Jörgen); B. Franke (Barbara); L.J. Launer (Lenore); S.E. Medland (Sarah Elizabeth); S. Seshadri (Sudha); P.M. Thompson (Paul); M.K. Ikram (Kamran)

    2017-01-01

    textabstractThe hippocampal formation is a brain structure integrally involved in episodic memory, spatial navigation, cognition and stress responsiveness. Structural abnormalities in hippocampal volume and shape are found in several common neuropsychiatric disorders. To identify the genetic

  19. Novel genetic loci associated with hippocampal volume

    NARCIS (Netherlands)

    Hibar, Derrek P.; Adams, Hieab H. H.; Jahanshad, Neda; Chauhan, Ganesh; Stein, Jason L.; Hofer, Edith; Renteria, Miguel E.; Bis, Joshua C.; Arias-Vasquez, Alejandro; Ikram, M. Kamran; Desrivières, Sylvane; Vernooij, Meike W.; Abramovic, Lucija; Alhusaini, Saud; Amin, Najaf; Andersson, Micael; Arfanakis, Konstantinos; Aribisala, Benjamin S.; Armstrong, Nicola J.; Athanasiu, Lavinia; Axelsson, Tomas; Beecham, Ashley H.; Beiser, Alexa; Bernard, Manon; Blanton, Susan H.; Bohlken, Marc M.; Boks, Marco P.; Bralten, Janita; Brickman, Adam M.; Carmichael, Owen; Chakravarty, M. Mallar; Chen, Qiang; Ching, Christopher R. K.; Chouraki, Vincent; Cuellar-Partida, Gabriel; Crivello, Fabrice; den Braber, Anouk; Doan, Nhat Trung; Ehrlich, Stefan; Giddaluru, Sudheer; Goldman, Aaron L.; Gottesman, Rebecca F.; Grimm, Oliver; Griswold, Michael E.; Guadalupe, Tulio; Gutman, Boris A.; Hass, Johanna; Haukvik, Unn K.; Hoehn, David; Holmes, Avram J.; Hoogman, Martine; Janowitz, Deborah; Jia, Tianye; Jørgensen, Kjetil N.; Karbalai, Nazanin; Kasperaviciute, Dalia; Kim, Sungeun; Klein, Marieke; Kraemer, Bernd; Lee, Phil H.; Liewald, David C. M.; Lopez, Lorna M.; Luciano, Michelle; Macare, Christine; Marquand, Andre F.; Matarin, Mar; Mather, Karen A.; Mattheisen, Manuel; McKay, David R.; Milaneschi, Yuri; Muñoz Maniega, Susana; Nho, Kwangsik; Nugent, Allison C.; Nyquist, Paul; Loohuis, Loes M. Olde; Oosterlaan, Jaap; Papmeyer, Martina; Pirpamer, Lukas; Pütz, Benno; Ramasamy, Adaikalavan; Richards, Jennifer S.; Risacher, Shannon L.; Roiz-Santiañez, Roberto; Rommelse, Nanda; Ropele, Stefan; Rose, Emma J.; Royle, Natalie A.; Rundek, Tatjana; Sämann, Philipp G.; Saremi, Arvin; Satizabal, Claudia L.; Schmaal, Lianne; Schork, Andrew J.; Shen, Li; Shin, Jean; Shumskaya, Elena; Smith, Albert V.; Sprooten, Emma; Strike, Lachlan T.; Teumer, Alexander; Tordesillas-Gutierrez, Diana; Toro, Roberto; Trabzuni, Daniah; Trompet, Stella; Vaidya, Dhananjay; van der Grond, Jeroen; van der Lee, Sven J.; van der Meer, Dennis; van Donkelaar, Marjolein M. J.; van Eijk, Kristel R.; van Erp, Theo G. M.; van Rooij, Daan; Walton, Esther; Westlye, Lars T.; Whelan, Christopher D.; Windham, Beverly G.; Winkler, Anderson M.; Wittfeld, Katharina; Woldehawariat, Girma; Wolf, Christiane; Wolfers, Thomas; Yanek, Lisa R.; Yang, Jingyun; Zijdenbos, Alex; Zwiers, Marcel P.; Agartz, Ingrid; Almasy, Laura; Ames, David; Amouyel, Philippe; Andreassen, Ole A.; Arepalli, Sampath; Assareh, Amelia A.; Barral, Sandra; Bastin, Mark E.; Becker, Diane M.; Becker, James T.; Bennett, David A.; Blangero, John; van Bokhoven, Hans; Boomsma, Dorret I.; Brodaty, Henry; Brouwer, Rachel M.; Brunner, Han G.; Buckner, Randy L.; Buitelaar, Jan K.; Bulayeva, Kazima B.; Cahn, Wiepke; Calhoun, Vince D.; Cannon, Dara M.; Cavalleri, Gianpiero L.; Cheng, Ching-Yu; Cichon, Sven; Cookson, Mark R.; Corvin, Aiden; Crespo-Facorro, Benedicto; Curran, Joanne E.; Czisch, Michael; Dale, Anders M.; Davies, Gareth E.; de Craen, Anton J. M.; de Geus, Eco J. C.; de Jager, Philip L.; de Zubicaray, Greig I.; Deary, Ian J.; Debette, Stéphanie; Decarli, Charles; Delanty, Norman; Depondt, Chantal; DeStefano, Anita; Dillman, Allissa; Djurovic, Srdjan; Donohoe, Gary; Drevets, Wayne C.; Duggirala, Ravi; Dyer, Thomas D.; Enzinger, Christian; Erk, Susanne; Espeseth, Thomas; Fedko, Iryna O.; Fernández, Guillén; Ferrucci, Luigi; Fisher, Simon E.; Fleischman, Debra A.; Ford, Ian; Fornage, Myriam; Foroud, Tatiana M.; Fox, Peter T.; Francks, Clyde; Fukunaga, Masaki; Gibbs, J. Raphael; Glahn, David C.; Gollub, Randy L.; Göring, Harald H. H.; Green, Robert C.; Gruber, Oliver; Gudnason, Vilmundur; Guelfi, Sebastian; Håberg, Asta K.; Hansell, Narelle K.; Hardy, John; Hartman, Catharina A.; Hashimoto, Ryota; Hegenscheid, Katrin; Heinz, Andreas; Le Hellard, Stephanie; Hernandez, Dena G.; Heslenfeld, Dirk J.; Ho, Beng-Choon; Hoekstra, Pieter J.; Hoffmann, Wolfgang; Hofman, Albert; Holsboer, Florian; Homuth, Georg; Hosten, Norbert; Hottenga, Jouke-Jan; Huentelman, Matthew; Pol, Hilleke E. Hulshoff; Ikeda, Masashi; Jack, Clifford R.; Jenkinson, Mark; Johnson, Robert; Jönsson, Erik G.; Jukema, J. Wouter; Kahn, René S.; Kanai, Ryota; Kloszewska, Iwona; Knopman, David S.; Kochunov, Peter; Kwok, John B.; Lawrie, Stephen M.; Lemaître, Hervé; Liu, Xinmin; Longo, Dan L.; Lopez, Oscar L.; Lovestone, Simon; Martinez, Oliver; Martinot, Jean-Luc; Mattay, Venkata S.; McDonald, Colm; McIntosh, Andrew M.; McMahon, Francis J.; McMahon, Katie L.; Mecocci, Patrizia; Melle, Ingrid; Meyer-Lindenberg, Andreas; Mohnke, Sebastian; Montgomery, Grant W.; Morris, Derek W.; Mosley, Thomas H.; Mühleisen, Thomas W.; Müller-Myhsok, Bertram; Nalls, Michael A.; Nauck, Matthias; Nichols, Thomas E.; Niessen, Wiro J.; Nöthen, Markus M.; Nyberg, Lars; Ohi, Kazutaka; Olvera, Rene L.; Ophoff, Roel A.; Pandolfo, Massimo; Paus, Tomas; Pausova, Zdenka; Penninx, Brenda W. J. H.; Pike, G. Bruce; Potkin, Steven G.; Psaty, Bruce M.; Reppermund, Simone; Rietschel, Marcella; Roffman, Joshua L.; Romanczuk-Seiferth, Nina; Rotter, Jerome I.; Ryten, Mina; Sacco, Ralph L.; Sachdev, Perminder S.; Saykin, Andrew J.; Schmidt, Reinhold; Schmidt, Helena; Schofield, Peter R.; Sigursson, Sigurdur; Simmons, Andrew; Singleton, Andrew; Sisodiya, Sanjay M.; Smith, Colin; Smoller, Jordan W.; Soininen, Hilkka; Steen, Vidar M.; Stott, David J.; Sussmann, Jessika E.; Thalamuthu, Anbupalam; Toga, Arthur W.; Traynor, Bryan J.; Troncoso, Juan; Tsolaki, Magda; Tzourio, Christophe; Uitterlinden, Andre G.; Hernández, Maria C. Valdés; van der Brug, Marcel; van der Lugt, Aad; van der Wee, Nic J. A.; van Haren, Neeltje E. M.; van 't Ent, Dennis; van Tol, Marie-Jose; Vardarajan, Badri N.; Vellas, Bruno; Veltman, Dick J.; Völzke, Henry; Walter, Henrik; Wardlaw, Joanna M.; Wassink, Thomas H.; Weale, Michael E.; Weinberger, Daniel R.; Weiner, Michael W.; Wen, Wei; Westman, Eric; White, Tonya; Wong, Tien Y.; Wright, Clinton B.; Zielke, Ronald H.; Zonderman, Alan B.; Martin, Nicholas G.; van Duijn, Cornelia M.; Wright, Margaret J.; Longstreth, W. T.; Schumann, Gunter; Grabe, Hans J.; Franke, Barbara; Launer, Lenore J.; Medland, Sarah E.; Seshadri, Sudha; Thompson, Paul M.; Ikram, M. Arfan

    2017-01-01

    The hippocampal formation is a brain structure integrally involved in episodic memory, spatial navigation, cognition and stress responsiveness. Structural abnormalities in hippocampal volume and shape are found in several common neuropsychiatric disorders. To identify the genetic underpinnings of

  20. Experiencing variation

    DEFF Research Database (Denmark)

    Kobayashi, Sofie; Berge, Maria; Grout, Brian William Wilson

    2017-01-01

    This study contributes towards a better understanding of learning dynamics in doctoral supervision by analysing how learning opportunities are created in the interaction between supervisors and PhD students, using the notion of experiencing variation as a key to learning. Empirically, we have bas...... were discussed, created more complex patterns of variation. Both PhD students and supervisors can learn from this. Understanding of this mechanism that creates learning opportunities can help supervisors develop their competences in supervisory pedagogy....

  1. An analytical model for shape memory alloy fiber-reinforced composite thin-walled beam undergoing large deflection

    Directory of Open Access Journals (Sweden)

    Yongsheng Ren

    2015-03-01

    Full Text Available The structural model of the thin-walled laminated beams with integral shape memory alloy active fibers and accounting for geometrically nonlinear is presented in this article. The structural modeling is split into two parts: a two-dimensional analysis over the cross section and a geometrically nonlinear analysis of a beam along the beam span. The variational asymptotic method is used to formulate the force–deformation relationship equations taking into account the presence of active shape memory alloy fibers distributed along the cross section of the beam. The geometrically nonlinear governing equations are derived using variational principle and based on the von Kármán-type nonlinear strain–displacement relations. The equations are then solved using Galerkin’s method and an incremental Newton–Raphson method. The validation for the proposed model has been carried out by comparison of the present results with those available in the literature. The results show that significant extension, bending, and twisting coupled nonlinear deflections occur during the phase transformation due to shape memory alloy actuation. The effects of the volume fraction of the shape memory alloy fiber and ply angle are also addressed.

  2. Exploration of continuous variability in collections of 3D shapes

    KAUST Repository

    Ovsjanikov, Maks

    2011-07-01

    As large public repositories of 3D shapes continue to grow, the amount of shape variability in such collections also increases, both in terms of the number of different classes of shapes, as well as the geometric variability of shapes within each class. While this gives users more choice for shape selection, it can be difficult to explore large collections and understand the range of variations amongst the shapes. Exploration is particularly challenging for public shape repositories, which are often only loosely tagged and contain neither point-based nor part-based correspondences. In this paper, we present a method for discovering and exploring continuous variability in a collection of 3D shapes without correspondences. Our method is based on a novel navigation interface that allows users to explore a collection of related shapes by deforming a base template shape through a set of intuitive deformation controls. We also help the user to select the most meaningful deformations using a novel technique for learning shape variability in terms of deformations of the template. Our technique assumes that the set of shapes lies near a low-dimensional manifold in a certain descriptor space, which allows us to avoid establishing correspondences between shapes, while being rotation and scaling invariant. We present results on several shape collections taken directly from public repositories. © 2011 ACM.

  3. PubChem3D: Shape compatibility filtering using molecular shape quadrupoles

    Directory of Open Access Journals (Sweden)

    Kim Sunghwan

    2011-07-01

    Full Text Available Abstract Background PubChem provides a 3-D neighboring relationship, which involves finding the maximal shape overlap between two static compound 3-D conformations, a computationally intensive step. It is highly desirable to avoid this overlap computation, especially if it can be determined with certainty that a conformer pair cannot meet the criteria to be a 3-D neighbor. As such, PubChem employs a series of pre-filters, based on the concept of volume, to remove approximately 65% of all conformer neighbor pairs prior to shape overlap optimization. Given that molecular volume, a somewhat vague concept, is rather effective, it leads one to wonder: can the existing PubChem 3-D neighboring relationship, which consists of billions of shape similar conformer pairs from tens of millions of unique small molecules, be used to identify additional shape descriptor relationships? Or, put more specifically, can one place an upper bound on shape similarity using other "fuzzy" shape-like concepts like length, width, and height? Results Using a basis set of 4.18 billion 3-D neighbor pairs identified from single conformer per compound neighboring of 17.1 million molecules, shape descriptors were computed for all conformers. These steric shape descriptors included several forms of molecular volume and shape quadrupoles, which essentially embody the length, width, and height of a conformer. For a given 3-D neighbor conformer pair, the volume and each quadrupole component (Qx, Qy, and Qz were binned and their frequency of occurrence was examined. Per molecular volume type, this effectively produced three different maps, one per quadrupole component (Qx, Qy, and Qz, of allowed values for the similarity metric, shape Tanimoto (ST ≥ 0.8. The efficiency of these relationships (in terms of true positive, true negative, false positive and false negative as a function of ST threshold was determined in a test run of 13.2 billion conformer pairs not previously considered

  4. Volume calculation of CT lung lesions based on Halton low-discrepancy sequences

    Science.gov (United States)

    Li, Shusheng; Wang, Liansheng; Li, Shuo

    2017-03-01

    Volume calculation from the Computed Tomography (CT) lung lesions data is a significant parameter for clinical diagnosis. The volume is widely used to assess the severity of the lung nodules and track its progression, however, the accuracy and efficiency of previous studies are not well achieved for clinical uses. It remains to be a challenging task due to its tight attachment to the lung wall, inhomogeneous background noises and large variations in sizes and shape. In this paper, we employ Halton low-discrepancy sequences to calculate the volume of the lung lesions. The proposed method directly compute the volume without the procedure of three-dimension (3D) model reconstruction and surface triangulation, which significantly improves the efficiency and reduces the complexity. The main steps of the proposed method are: (1) generate a certain number of random points in each slice using Halton low-discrepancy sequences and calculate the lesion area of each slice through the proportion; (2) obtain the volume by integrating the areas in the sagittal direction. In order to evaluate our proposed method, the experiments were conducted on the sufficient data sets with different size of lung lesions. With the uniform distribution of random points, our proposed method achieves more accurate results compared with other methods, which demonstrates the robustness and accuracy for the volume calculation of CT lung lesions. In addition, our proposed method is easy to follow and can be extensively applied to other applications, e.g., volume calculation of liver tumor, atrial wall aneurysm, etc.

  5. Shape from touch

    NARCIS (Netherlands)

    Kappers, A.M.L.; Bergmann Tiest, W.M.

    2014-01-01

    The shape of objects cannot only be recognized by vision, but also by touch. Vision has the advantage that shapes can be seen at a distance, but touch has the advantage that during exploration many additional object properties become available, such as temperature (Jones, 2009), texture (Bensmaia,

  6. Statistical Shape Modeling of Proximal Femoral Shape Deformities in Legg-Calvé-Perthes Disease and Slipped Capital Femoral Epiphysis

    Science.gov (United States)

    Chan, Elaine F.; Farnsworth, Christine L.; Koziol, James A.; Hosalkar, Harish S.; Sah, Robert L.

    2013-01-01

    Introduction The current understanding of morphological deformities of the hip such as femoroacetabular impingement (FAI), Legg-Calve-Perthes disease (LCPD), and slipped capital femoral epiphysis (SCFE) is based on 2-dimensional metrics, primarily involving the femoral head, that only partially describe the complex skeletal morphology. Objective This study aimed to improve the 3-dimensional understanding of shape variations during normal growth, and in LCPD and SCFE, through statistical shape modeling. Design Thirty-two patients with asymptomatic, LCPD, and SCFE hips, determined from physical and radiographic examination, were scanned using 3-D CT at a voxel size of (0.5–0.9mm)2 in-plane and 0.63mm slice thickness. Statistical shape modeling was performed on segmented proximal femoral surfaces to determine modes of variation and shape variables quantifying 3-D shape. In addition, conventional variables were determined for all femora. Results Proximal femur shape was described by 8 modes of variation and corresponding shape variables. Statistical shape variables were distinct with age and revealed coordinated, growth-associated differences in neck length-to-width ratio, femoral head medialization, and trochanter protrusion. After size and age-based shape adjustment, diseased proximal femora were characterized by shape variables distinct from those of asymptomatic hips. The shape variables defined morphology in health and disease, and were correlated with certain conventional variables of shape, including neck-shaft angle, head diameter, and neck diameter. Conclusion 3-D quantitative analyses of proximal femoral bone shape during growth and in disease are useful for furthering the understanding of normal and abnormal shape deviations which affect cartilage biomechanics and risk of developing osteoarthritis. PMID:23274103

  7. Variational analysis

    CERN Document Server

    Rockafellar, R Tyrrell

    1998-01-01

    From its origins in the minimization of integral functionals, the notion of 'variations' has evolved greatly in connection with applications in optimization, equilibrium, and control. It refers not only to constrained movement away from a point, but also to modes of perturbation and approximation that are best describable by 'set convergence', variational convergence of functions and the like. This book develops a unified framework and, in finite dimension, provides a detailed exposition of variational geometry and subdifferential calculus in their current forms beyond classical and convex analysis. Also covered are set-convergence, set-valued mappings, epi-convergence, duality, maximal monotone mappings, second-order subderivatives, measurable selections and normal integrands. The changes in this 3rd printing mainly concern various typographical corrections, and reference omissions that came to light in the previous printings. Many of these reached the authors' notice through their own re-reading, that of th...

  8. Variational principles

    CERN Document Server

    Moiseiwitsch, B L

    2004-01-01

    This graduate-level text's primary objective is to demonstrate the expression of the equations of the various branches of mathematical physics in the succinct and elegant form of variational principles (and thereby illuminate their interrelationship). Its related intentions are to show how variational principles may be employed to determine the discrete eigenvalues for stationary state problems and to illustrate how to find the values of quantities (such as the phase shifts) that arise in the theory of scattering. Chapter-by-chapter treatment consists of analytical dynamics; optics, wave mecha

  9. The exchangeability of shape

    Directory of Open Access Journals (Sweden)

    Kaba Dramane

    2010-10-01

    Full Text Available Abstract Background Landmark based geometric morphometrics (GM allows the quantitative comparison of organismal shapes. When applied to systematics, it is able to score shape changes which often are undetectable by traditional morphological studies and even by classical morphometric approaches. It has thus become a fast and low cost candidate to identify cryptic species. Due to inherent mathematical properties, shape variables derived from one set of coordinates cannot be compared with shape variables derived from another set. Raw coordinates which produce these shape variables could be used for data exchange, however they contain measurement error. The latter may represent a significant obstacle when the objective is to distinguish very similar species. Results We show here that a single user derived dataset produces much less classification error than a multiple one. The question then becomes how to circumvent the lack of exchangeability of shape variables while preserving a single user dataset. A solution to this question could lead to the creation of a relatively fast and inexpensive systematic tool adapted for the recognition of cryptic species. Conclusions To preserve both exchangeability of shape and a single user derived dataset, our suggestion is to create a free access bank of reference images from which one can produce raw coordinates and use them for comparison with external specimens. Thus, we propose an alternative geometric descriptive system that separates 2-D data gathering and analyzes.

  10. Evolutionary significance of epigenetic variation

    NARCIS (Netherlands)

    Richards, C.L.; Verhoeven, K.J.F.; Bossdorf, O.; Wendel, J.F.; Greilhuber, J.; Dolezel, J.; Leitch, I.J.

    2012-01-01

    Several chapters in this volume demonstrate how epigenetic work at the molecular level over the last few decades has revolutionized our understanding of genome function and developmental biology. However, epigenetic processes not only further our understanding of variation and regulation at the

  11. Modeling Per Capita State Health Expenditure Variat...

    Data.gov (United States)

    U.S. Department of Health & Human Services — Modeling Per Capita State Health Expenditure Variation State-Level Characteristics Matter, published in Volume 3, Issue 4, of the Medicare and Medicaid Research...

  12. Shape memory polymer foams

    Science.gov (United States)

    Santo, Loredana

    2016-02-01

    Recent advances in shape memory polymer (SMP) foam research are reviewed. The SMPs belong to a new class of smart polymers which can have interesting applications in microelectromechanical systems, actuators and biomedical devices. They can respond to specific external stimulus changing their configuration and then remember the original shape. In the form of foams, the shape memory behaviour can be enhanced because they generally have higher compressibility. Considering also the low weight, and recovery force, the SMP foams are expected to have great potential applications primarily in aerospace. This review highlights the recent progress in characterization, evaluation, and proposed applications of SMP foams mainly for aerospace applications.

  13. Use of otolith-shape analysis for stock discrimination of Boops ...

    African Journals Online (AJOL)

    Oran, Bejaia and Annaba) between 2013 and 2016 were digitised and analysed for shape variation by elliptical Fourier analysis. Potential confounding sources of variation (fish length, age and sex, and left or right otolith position) were examined ...

  14. Shapes of sedimenting soft elastic capsules in a viscous fluid.

    Science.gov (United States)

    Boltz, Horst-Holger; Kierfeld, Jan

    2015-09-01

    Soft elastic capsules which are driven through a viscous fluid undergo shape deformation coupled to their motion. We introduce an iterative solution scheme which couples hydrodynamic boundary integral methods and elastic shape equations to find the stationary axisymmetric shape and the velocity of an elastic capsule moving in a viscous fluid at low Reynolds numbers. We use this approach to systematically study dynamical shape transitions of capsules with Hookean stretching and bending energies and spherical rest shape sedimenting under the influence of gravity or centrifugal forces. We find three types of possible axisymmetric stationary shapes for sedimenting capsules with fixed volume: a pseudospherical state, a pear-shaped state, and buckled shapes. Capsule shapes are controlled by two dimensionless parameters, the Föppl-von-Kármán number characterizing the elastic properties and a Bond number characterizing the driving force. For increasing gravitational force the spherical shape transforms into a pear shape. For very large bending rigidity (very small Föppl-von-Kármán number) this transition is discontinuous with shape hysteresis. The corresponding transition line terminates, however, in a critical point, such that the discontinuous transition is not present at typical Föppl-von-Kármán numbers of synthetic capsules. In an additional bifurcation, buckled shapes occur upon increasing the gravitational force. This type of instability should be observable for generic synthetic capsules. All shape bifurcations can be resolved in the force-velocity relation of sedimenting capsules, where up to three capsule shapes with different velocities can occur for the same driving force. All three types of possible axisymmetric stationary shapes are stable with respect to rotation during sedimentation. Additionally, we study capsules pushed or pulled by a point force, where we always find capsule shapes to transform smoothly without bifurcations.

  15. Variations in Dimensions and Shape of Thoracic Cage with Aging ...

    African Journals Online (AJOL)

    We had systematically reviewed, compared and analysed many original and review articles related to aging changes in chest wall images and with the aid of radiological findings recorded in a span of four years. We have concluded that alterations in the geometric dimensions of thoracic wall, change in the pattern and ...

  16. Terrestrial carbon and intraspecific size-variation shape lake ecosystems

    NARCIS (Netherlands)

    Jansson, M.; Persson, L.; de Roos, A.M.; I. Jones, R.; Tranvik, L.J.

    2007-01-01

    Conceptual models of lake ecosystem structure and function have generally assumed that energy in pelagic systems is derived from in situ photosynthesis and that its use by higher trophic levels depends on the average properties of individuals in consumer populations. These views are challenged by

  17. Spectral shape variation of interstellar electrons at high energies

    Science.gov (United States)

    Tan, L. C.

    1985-01-01

    The high energy electron spectrum analysis has shown that the electron intensity inside the H2 cloud region, or in a spiral arm, should be much lower than that outside it and the observed electron energy spectrum should flatten again at about 1 TeV. In the framework of the leady box model the recently established rigidity dependence of the escape pathlength of cosmic rays would predict a high energy electron spectrum which is flatter than the observed one. This divergence is explained by assuming that the leaky box model can only apply to cosmic ray heavy nuclei, and light nuclei and electrons in cosmic rays may have different behaviors in the interstellar propagation. Therefore, the measured data on high energy electrons should be analyzed based on the proposed nonuniform galactic disk (NUGD) mode.

  18. variation of some waste stabilization pond parameters with shape

    African Journals Online (AJOL)

    Waste Stabilization Pond (WSP) are designed to provide control environment for wastewater treatment. The primary purpose of wastewater treatment is the reduction of pathogenic contamination, suspended solids, oxygen demand and nutrient environment. The geometry of the pond could be structured in order to give the ...

  19. Variation of some Waste Stabilization Pond Parameters with Shape ...

    African Journals Online (AJOL)

    Waste Stabilization Pond (WSP) are designed to provide control environment for wastewater treatment. The primary purpose of wastewater treatment is the reduction of pathogenic contamination, suspended solids, oxygen demand and nutrient environment. The geometry of the pond could be structured in order to give the ...

  20. Doughnut-shaped soap bubbles.

    Science.gov (United States)

    Préve, Deison; Saa, Alberto

    2015-10-01

    Soap bubbles are thin liquid films enclosing a fixed volume of air. Since the surface tension is typically assumed to be the only factor responsible for conforming the soap bubble shape, the realized bubble surfaces are always minimal area ones. Here, we consider the problem of finding the axisymmetric minimal area surface enclosing a fixed volume V and with a fixed equatorial perimeter L. It is well known that the sphere is the solution for V=L(3)/6π(2), and this is indeed the case of a free soap bubble, for instance. Surprisingly, we show that for Vbubble is known to be ultimately unstable and, hence, it will eventually lose its axisymmetry by breaking apart in smaller bubbles. Indisputably, however, the topological transition from spherical to toroidal surfaces is mandatory here for obtaining the global solution for this axisymmetric isoperimetric problem. Our result suggests that deformed bubbles with V<αL(3)/6π(2) cannot be stable and should not exist in foams, for instance.

  1. Shape memory polyurethane foams

    Directory of Open Access Journals (Sweden)

    B. K. Kim

    2012-01-01

    Full Text Available Molded flexible polyurethane (PU foams have been synthesized from polypropylene glycol (PPG with different molecular weights (Mw and functionalities (f, and 2,4/2,6-toluene diisocyanate (TDI-80 with water as blowing agent. It was found that the glassy state properties of the foam mainly depended on the urethane group content while the rubbery state properties on the crosslink density. That is, PPG of low MW and low f (more urethane groups provided superior glass state modulus, strength, density, shape fixity and glass transition temperature (Tg, while that of high Mw and high f (higher crosslink density showed high rubbery modulus and shape recovery. Consequently shape fixity of low Mw PPG decreased from 85 to 72% while shape recovery increased from 52 to 63% as the content of high Mw PPG increased from 0 to 40%.

  2. Shaft mode shape demonstration

    Science.gov (United States)

    Grissom, R.

    1985-01-01

    The dynamic response of a rotating machine is directly influenced by its geometric configuration and all aspects of the rotor construction. These determine two significant parameters, mass distribution and stiffness, which yield a spectrum of natural frequencies and mode shapes. The mode shapes can be presented as snapshots of the characteristic amplitude/phase reponse patterns of the shaft, due to the major forcing function of unbalance, at different rotative speeds. To demonstrate the three shaft mode shapes of the rotor rig using the Shaft Mode Demonstrator and oscilloscopes. The synchronous (1X) amplitude and phase of the rotor vibration in the vertical direction from several points along the shaft is displayed on corresponding points of the demonstrator. Unfiltered vibration from vertical and horizontal probe pairs is displayed on the oscilloscopes in orbit format for a dynamic presentation of the mode shape.

  3. Shape memory polyurethane nanocomposites

    Science.gov (United States)

    Cao, Feina

    Shape memory polymers are smart materials which can remember their original shapes. However, the low recovery stress and low mechanical strength limit the commercial applications of shape memory polymers. In this study, nanoclays were introduced to shape memory polyurethanes (SMPU) to augment these properties by enhance the network of SMPU. Several factors which influence the shape recovery stress were evaluated, including the nature of polymer chain by using different monomers, type of clay particles, extent of filler dispersion, clay content and deformation conditions. It was found that only reactive clay particles were well dispersed into polyurethane matrix by the tethering between --CH2CH 2OH functional groups in clay surfactants and polyurethane chains. Two different shape memory polyurethanes (Systems I & II) prepared by bulk polymerization were compared. The shape memory effect of System I was triggered by melting of the soft segment crystals, while that of System II was by glass transition of the soft segments. It was seen that the reactive clay particles dispersed well in both polyurethane matrices and augmented the recovery stress, e.g., 20% increase with 1 wt % nanoclay in System I and 40% increase with 5 wt % nanoclay in System II were observed. In System I, clay particles interfered with soft segment crystallization, and promoted phase mixing between the hard and soft segments, thus affecting the fixity and recovery ratio. Nevertheless, the soft segment crystallinity was still enough and in some cases increased due to stretching to exhibit excellent shape fixity and shape recovery ratio. The higher loading of clay particles accelerated the stress relaxation, resulting in reduction of recovery stress. In System II, no significant effect of clay particles in phase separation was observed, so there was no influence of clay on shape fixity and recovery ratio. The recovery stress increased with reactive nanoclay content. It was also found that the recovery

  4. Variation and incidence of agenesis of the pyramidalis muscles in ...

    African Journals Online (AJOL)

    In recognition of the variations in occurrence, shape and size of the pyramidalis muscle in different races, sexes and nationals and its relevance in flap and graft, this study was carried out to determine the incidence of its agenesis, variation in occurrence, shape and mean values of length and breadth in Nigerian males.

  5. A level set approach for left ventricle detection in CT images using shape segmentation and optical flow

    Science.gov (United States)

    Brieva, Jorge; Moya-Albor, Ernesto; Escalante-Ramírez, Boris

    2015-01-01

    The left ventricle (LV) segmentation plays an important role in a subsequent process for the functional analysis of the LV. Typical segmentation of the endocardium wall in the ventricle excludes papillary muscles which leads to an incorrect measure of the ejected volume in the LV. In this paper we present a new variational strategy using a 2D level set framework that includes a local term for enhancing the low contrast structures and a 2D shape model. The shape model in the level set method is propagated to all image sequences corresponding to the cardiac cycles through the optical flow approach using the Hermite transform. To evaluate our strategy we use the Dice index and the Hausdorff distance to compare the segmentation results with the manual segmentation carried out by the physician.

  6. Light Shaping with Holography, GPC and Holo-GPC

    DEFF Research Database (Denmark)

    Banas, Andrew; Glückstad, Jesper

    2017-01-01

    Light shaping techniques based on phase-only modulation offer multiple advantages over amplitude modulation. This review examines and compares the merits of two phase modulation techniques; phase-only computer generated holography and Generalized Phase Contrast (GPC). Both techniques are briefly...... Holo-GPC utilizes the simplicity of GPC in forming well-defined speckle-free shapes and the versatility of holography in distributing these shaped beams over an extended 3D volume. To conclude, we cite applications where the combined strengths of the two photon-efficient phase-only light shaping...

  7. Shaping the Global Environment

    Science.gov (United States)

    2002-04-09

    SHAPING THE GLOBAL ENVIRONMENT BY LIEUTENANT COLONEL MICHAEL D. ELLERBE United States Army DISTRIBUTION STATEMENT A: Approved for public release...THE GLOBAL ENVIRONMENT by Lieutenant Colonel Michael D. Ellerbe United States Army Colonel Jef Troxel Project Advisor The views expressed in this...Distribution is unlimited. ii ABSTRACT AUTHOR: Michael D. Ellerbe TITLE: SHAPING THE GLOBAL ENVIRONMENT FORMAT: Strategy Research Project DATE: 09 April

  8. Detecting global and local hippocampal shape changes in Alzheimer's disease using statistical shape models

    NARCIS (Netherlands)

    Shen, Kai-kai; Fripp, Jurgen; Mériaudeau, Fabrice; Chételat, Gaël; Salvado, Olivier; Bourgeat, Pierrick; Saradha, A.; Abdi, Hervé; Abdulkadir, Ahmed; Acharya, Deepa; Achuthan, Anusha; Adluru, Nagesh; Aghajanian, Jania; Agrusti, Antonella; Agyemang, Alex; Ahdidan, Jamila; Ahmad, Duaa; Ahmed, Shiek; Aisen, Paul; Akhondi-Asl, Alireza; Aksu, Yaman; Alberca, Roman; Alcauter, Sarael; Alexander, Daniel; Alin, Aylin; Almeida, Fabio; Alvarez-Lineara, Juan; Amlien, Inge; Anand, Shyam; Anderson, Dallas; Ang, Amma; Angersbach, Steve; Ansarian, Reza; Aoyama, Eiji; Appannah, Arti; Arfanakis, Konstantinos; Armor, Tom; Arrighi, Michael; Arumughababu, S. Vethanayaki; Arunagiri, Vidhya; Ashe-McNalley, Cody; Ashford, Wes; Le Page, Aurelie; Avants, Brian; Aviv, Richard; Awasthi, Sukrati; Ayache, Nicholas; Ayan-Oshodi, Mosun; Ayhan, Murat; Sumana, B. V.; Babic, Tomislav; Baek, Young; Bagepally, Bhavani; Baird, Geoffrey; Baker, John; Baker, Suzanne; Bakker, Arnold; Barbash, Shahar; Bard, Jonathan; Barker, Warren; Bartlett, Jonathan; Baruchin, Andrea; Battaglini, Iacopo; Bauer, Corinna; Bayley, Peter; Beck, Irene; Becker, James; Becker, J. Alex; Beckett, Laurel; Bednar, Martin; Bedner, Arkadiusz; Beg, Mirza Faisal; Bekris, Lynn; Belaroussi, Boubakeur; Belloch, Vicente; Belmokhtar, Nabil; Ben Ahmed, Olfa; Bender, J. Dennis; Benois-Pineau, Jenny; Bhaskar, Uday; Bienkowska, Katarzyna; Biffi, Alessandro; Bigler, Erin; Bilgic, Basar; Bishop, Courtney; Bittner, Daniel; Black, Sandra; Bloss, Cinnamon; Bocti, Christian; Bohorquez, Adriana; Bokde, Arun; Boone, John; Boppana, Madhu; Borrie, Michael; Bouttout, Haroune; Bowes, Mike; Bowman, DuBois; Bowman, Gene; Bracard, Serge; Braskie, Meredith; Braunewell, Karl; Breitner, Joihn; Bresell, Anders; Brewer, James; Brickhouse, Michael; Brickman, Adam; Britschgi, Markus; Broadbent, Steve; Brogren, Jacob; Brunton, Simon; Buchsbaum, Monte; Buckley, Chris; Buerger, Katharina; Bunce, David; Burnham, Samantha; Burns, Jeffrey; Burton, David; Burzykowski, Tomasz; Butler, Tracy; Cabeza, Rafael; Caffery, Terrell; Cairns, Nigel; Callhoff, Johanna; Calvini, Piero; Carbotti, Angela; Carle, Adam; Carmasin, Jeremy; Carmichael, Owen; Carvalho, Janessa; Casabianca, Jodi; Casanova, Ramon; Casey, Anne; Cash, David; Cataldo, Rosella; Cedarbaum, Jesse; Cella, Massimo; Celsis, Pierre; Chakravarty, Mallar; Chang, Ih; Chao, Linda; Charil, Arnaud; Chang, Che-Wei; Chemali, Zeina; Chen, Kewei; Chen, Shuzhong; Chen, Rong; Chen, Qiang; Chen, Jung-Tai; Chen, Gang; Chen, Jake; Chen, Wei; Cheng, Wei-Chen; Cheng, Xi; Cherkas, Yauheniya; Chertkow, Howard; Cheung, Vinci; Cheung, Charlton; Chiang, Gloria; Chiao, Ping; chibane, Mouatez Billah; Chida, Noriko; Chin, Simon; Ching, Christopher; Chisholm, Jane; Cho, Claire; Cho, Youngsang; Choe, John; Choubey, Suresh; Chowbina, Sudhir; Christensen, Anette Luther; Ciocia, Gianluigi; Clark, David; Clark, Chris; Clarkson, Matt; Clerc, Stephanie; Clunie, David; Coen, Michael; Ciombra, Alexandre; Compton, David; Coppola, Giovanni; Coubard, Olivier; Coulin, Samuel; Cover, Keith S.; Crane, Paul; Crans, Gerald; Croop, Robert; Crowther, Daniel; Crum, William; Cui, Yue; Curry, Charles; Cutter, Gary; Da, Long; Daliri, Mohammad Reza; Damato, Vito Domenico; Darby, Eveleen; Darkner, Sune; Davatzikos, Christos; DavidPrakash, Bhaskaran; Davidson, Christopher; Davis, Melissa; de Bruijne, Marleen; de Meyer, Geert; de Nunzio, Giorgio; Decarli, Charles; Dechairo, Bryan; DeDuck, Kristina; Dehghan, Hossein; Delfino, Manuel; Della Rosa, Pasquale Anthony; Dellavedova, Luca; Delpassand, Ebrahim; Delrieu, Julien; DeOrchis, Vincent; Dépy Carron, Delphine; Desjardins, Benoit; deToledo-Morrell, Leyla; Devanand, Davangere; Devanarayan, Viswanath; Devier, Deidre; DeVous, Michael; Dgetluck, Nancy; Di, Jianing; Di, Xin; Diaz-Arrastia, Ramon; Dickerson, Bradford; Dickie, David Alexander; Dill, Vanderson; Ding, Xiaobo; Dinov, Ivo; Dobosh, Brian; Dobson, Howard; Dodge, Hiroko; Dolman, Andrew; Dolmo, Bess-Carolina; Donohue, Michael; Dore, Vincent; Dorflinger, Ernest; Dowling, Maritza; Dragicevic, Natasa; Dubal, Dena; Duchesne, Simon; Duff, Kevin; Dukart, Jürgen; Durazzo, Timothy; Dutta, Joyita; DWors, Robert; Earl, Nancy; Edula, Goutham; Elcoroaristizabal, Xabier; Emahazion, Tesfai; Endres, Christopher; Epstein, Noam; Ereshefsky, Larry; Eskildsen, Simon; Espinosa, Ana; Esposito, Mario; Ewers, Michael; Falcone, Guido; Fan, Yong; Fan, Jing; Fan, Lingzhong; Farahibozorg, Seyedehrezvan; Farb, Norman; Fardo, David; Farias, Sarah; Farnum, Michael; Farrer, Lindsay; Fatke, Bastian; Faux, Noel; Feldman, Howard; Feldman, Susan; Feldman, Betsy; Félix, Zandra; Fennema-Notestine, Christine; Fernandes, Michel; Fernandez, Elsa; Ferreira, Manuel Joao; Ferrer, Eugene; Fetterman, Bob; Figurski, Michal; Fillit, Howard; Finch, Stephen; Fiot, Jean-Baptiste; Flenniken, Derek; Fletcher, Evan; Flores, Christopher; Longmire, Crystal Flynn; Focke, Niels; Forman, Mark; Forsythe, Alan; Fox, Steven; Fox-Bosetti, Sabrina; Foxhall, Suzanne; Franko, Edit; Freeman, Roderick; Friedrich, Christoph M.; Friesenhahn, Michel; Frisoni, Giovanni; Fritzsche, Klaus; Fujimoto, Yoko; Fujiwara, Ken; Fullerton, Terence; Gaffour, Yacine; Galvin, Ben; Gamst, Anthony; Gao, Sujuan; Garg, Gaurav; Gaser, Christian; Gastineau, Edward; Gattaz, Wagner; Gaubert, Malo; Gauthier, Serge; Gavett, Brandon; Ge, Tian; Gemme, Gianluca; Geraci, Joseph; Gholipour, Farhad; Ghosh, Debashis; Ghosh, Satrajit; Gieschke, Ronald; Gill, Ryan; Gillespie, William; Gitelman, Darren; Gkontra, Xenia; Gleason, Carey; Glymour, M. Maria; Godbey, Michael; Gold, Brian; Goldberg, Terry; Goldman, Jennifer; Gonzalez-Beltran, Alejandra; Goodro, Robert; Gore, Chris; Gorriz, Juan Manuel; Goto, Masami; Grachev, Igor; Gradkowski, Wojciech; Grandey, Emily; Grasela, Thaddeus; Gray, Katherine; Greenberg, Barry; Greicius, Michael; Grill, Joshua; Gross, Alden; Gross, Alan; Grydeland, Håkon; Guignot, Isabelle; Guo, Qimiao; Guo, Liang-Hao; Guo, Hongbin; Gupta, Vinay; Guyot, Jennifer; Habeck, Christian; Habte, Frezghi; Haight, Thaddeus; Hajaj, Chen; Hajiesmaeili, Maryam; Hajjar, Ihab; Hammarstrom, Per; Hampel, Harald; Han, Duke; Han, Jian; Han, Zhaoying; Hanna, Yousef; Hao, Yongfu; Hardy, Peter; Harvey, Danielle; Hasan, Md Kamrul; Hayashi, Toshihiro; Haynes, John-Dylan; He, Huiguang; He, Yong; Head, Denise; Heckemann, Rolf; Heegaard, Niels; Heidebrink, Judith; Hellyer, Peter; Helwig, Michael; Henderson, David; Herholz, Karl; Herskovits, A. Zara; Hess, Christopher; Hildenbrand, Maike; Ming, Au Yeung Ho; Hobart, Jeremy; Hochstetler, Helen; Hofer, Scott; Hoffman, John; Holder, Daniel; Hollingworth, Paul; Holmes, Robin; Hong, Quan; Honigberg, Lee; Hope, Thomas; Hoppin, Jack; Hot, Pascal; Hou, Yangyang; Hsieh, Helen; Hsu, Ailing; Hu, Xiaochen; Hu, Mingxing; Hu, William; Hua, Wen-Yu; Huang, Shuai; Huang, Fude; Huang, Zihan; Huang, Chun-Jung; Huang, Chien-Chih; Huang, Juebin; Hubbard, Rebecca; Huentelman, Matthew; Huppertz, Hans-Jürgen; Hurko, Orest; Hurt, Stephen; Hutchins, Jim; Hwang, Scott; Hyun, JungMoon; Ifeachor, Emmanuel; Iglesias, Martina; Ikari, Yasuhiko; Ikonomidou, Vasiliki; Iman, Adjoudj; Imani, Farzin; Immermann, Fred; Inlow, Mark; Inoue, Lurdes; Insel, Philip; Irizarry, Michael; Ishibashi, Taro; Ishii, Kenji; Ismail, Sara; Ito, Kaori; Iturria-Medina, Yasser; Iwatsubo, Takeshi; Jacks, Adam; Jacobson, Mark; Jacqmin, Philippe; Jaffe, Carl; Jagust, William; Janousova, Eva; Jara, Hernan; Jasperse, Bas; Jedynak, Bruno; Jefferson, Angela; Jennings, J. Richard; Jenq, John; Jessen, Walter; Jia, Fucang; Jiang, Tianzi; Jiao, Yun; Jing, Huang; Johnson, Kent; Johnson, Sterling; Johnson, David K.; Johnson, Julene; Jones, Gareth; Jones, Mark; Jones, Richard; Joshi, Shantanu; Jouvent, Eric; Juengling, Freimut; Julin, Per; Junjie, Zhuo; Kabilan, Meena; Kadish, Bill; Kairui, Zhang; Kam, Hye Jin; Kamboh, M. Ilyas; Kamer, Angela; Kanakaraj, Sithara; Kanchev, Vladimir; Kaneko, Tomoki; Kaneta, Tomohiro; Kang, Hyunseok; Kang, Ju Hee; Kang, Jian; Karageorgiou, Elissaios; Karantzoulis, Stella; Karlawish, Jason; Katz, Elyse; Kaushik, Sandeep S.; Kauwe, John; Kawakami, Hirofumi; Kawashima, Shoji; Kaye, Edward; Kazemi, Samaneh; Ke, Han; Kelleher, Thomas; Kennedy, Richard; Keogh, Bart; Kerchner, Geoffrey; Kerr, Daniel; Keshava, Nirmal; Khalil, Iya; Khalil, Andre; Khondker, Zakaria; Kihara, Takeshi; Killeen, Neil; Killiany, Ron; Kim, Dajung; Kim, Hyoungkyu; Kim, Seongkyun; Kim, Jong Hun; Kim, Ana; Kim, Jung-Hyun; Kimberg, Daniel; Kimura, Tokunori; King, Richard; Kirby, Justin; Kirsch, Wolff; Klimas, Michael; Kline, Richard; Kling, Mitchel; Klopfenstein, Erin; Koen, Joshua; Koikkalainen, Juha; Kokomoor, Anders; Kong, Xiangnan; Koppel, Jeremy; Korolev, Igor; Kotran, Nickolas; Kowalczyk, Adam; Krahnke, Tillmann; Krams, Michael; Kuceyeski, Amy; Kuhl, Donald; Kumar, Vinod; Roy, P. Kumar; Kuo, Julie; Labrish, Catherine; Lai, Song; Lakatos, Anita; Lalonde, François; Lam, On Ki; Lampron, Antoine; Landau, Susan; Lane, Richard; Lane, Barton; Langbaum, Jessica; Langford, Dianne; Lanius, Vivian; Latella, Marco; Leahy, Richard; an Lee, Jong; Lee, Dongsoo; Lee, Noah; Lee, Sei; Lee, Doheon; Lee, Grace; Lefkimmiatis, Stamatis; Lemaitre, Herve; Lenfant, Pierre; Lenz, Robert; Leong, Josiah; Leoutsakos, Jeannie-Marie; Leung, Yuk Yee; Levey, Alan; Li, Rui; Li, Xiaodong; Li, Weidong; Li, Xiaobo; Li, Ming; Li, Lexin; Li, Jun; Li, Gang; Li, Quanzheng; Li, Yi; Li, Junning; Li, Jie; Li, Yue; Li, Shanshan; Liang, Kelvin; Liang, Kuchang; Liang, Peipeng; Liang, Lichen; Liao, Weiqi; Liaquat, Saad; Liberman, Gilad; Lin, Lan; Lin, Ai-Ling; Lin, Frank; Liu, Tao; Liu, Dazhong; Liu, Li; Liu, Honggang; Liu, Sidong; Liu, Tianming; Liu, Xiuwen; Liu, Sophia; Liu, Linda; Liu, Wei; Liu, Guodong; Liu, Yangping; Liu, Collins; Lo, Raymond; Lobanov, Victor; Lockhart, Andrew; Loewenstein, David; Logovinsky, Veronika; Long, Miaomiao; Long, Ziyi; Long, Xiaojing; Looi, Jeffrey; Lu, Huanxiang; Lu, Po-Haong; Lucena, Nathaniel; Lukas, Carsten; Lukic, Ana; Luo, Lei; Luo, Xiongjian; Luo, Xi; Lynch, John; Ma, Shen-Ming; Mackin, Scott; Mada, Marius; Madabhushi, Anant; Maglio, Silvio; Mahanta, Mohammad Shahin; Maikusa, Norihide; Maldjian, Joseph; Mandal, Indrajit; Manjon, Jose; Mantri, Ninad; Manzour, Amir; Marchewka, Artur; Marcus, Daniel; Margolin, Richard; Marrett, Sean; Marshall, Gad; Gonzalez, Alberto Martinez; Torteya, Antonio Martinez; Mather, Mara; Mathis, Chester; Mattei, Peter; Matthews, Dawn; McArdle, John; McCarroll, Steven; McEvoy, Linda; McGeown, William; McGinnis, Scott; McGonigle, John; McIntyre, John; McLaren, Donald; McQuail, Joseph; Meadowcroft, Mark; Meda, Shashwath; Melie-Garcia, Lester; Melrose, Rebecca; Mendelson, Alexander; Mendez, Mario; Menendez, Enrique; Meng, Meng; Meredith, Jere; Metti, Andrea; Meyer, Carsten; Mez, Jesse; Mickael, Guedj; Miftahof, Roustem; Mikula, Margit; Miller, Michael; Millikin, Colleen; Mintun, Mark; Mirza, Mubeena; Mistridis, Panagiota; Mitchell, Meghan; Mitsis, Effie; Mon, Anderson; Moore, Dana; Morabito, Francesco C.; Birgani, Parmida Moradi; Moratal, David; Morimoto, Bruce; Mormino, Elizabeth; Morris, Jill; Mortamet, Bénédicte; Moscato, Pablo; Mueller, Kathyrne; Mueller, Susanne; Mukherjee, Shubhabrata; Mulder, Emma; Mungas, Dan; Munir, Kamran; Murayama, Shigeo; Murphy, Michael; Myers, Amanda; Sairam, N.; Nagata, Ken; Nair, Anil; Nativio, Raffaella; Nazarparvar, Babak; Nazeri, Arash; Nejad, Leila; Nekooei, Sirous; Nettiksimmons, Jasmine; Neu, Scott; Ng, Yen-Bee; Nguyen, Nghi; Nichols, Thomas; Nicodemus, Kristin; Niecko, Timothy; Nielsen, Casper; Nishio, Tomoyuki; Nordstrom, Matthew; Noshad, Sina; Notomi, Keiji; Novak, Nic; Nutakki, Gopi Chand; O'Bryant, Sid; Obisesan, Thomas; Oh, Joonmi; Okonkwo, Ozioma; Olde Rikkert, Marcel; Oliveira, Ailton; Oliveira, João; Oliver, Ruth; Olmos, Salvador; Oltra, Javier; Ortner, Marion; Osadebey, Michael; Ostrowitzki, Susanne; Overholser, Rosanna; Anishiya, P.; Chitra, P. K. A.; Pa, Judy; Palanisamy, Preethi; Pan, Sarah; Pan, Zhifang; Pande, Yogesh; Pardo, Jose; Pardoe, Heath; Park, Sang hyun; Park, Sujin; Park, Lovingly; Park, Hyunjin; Park, Moon Ho; Parker, Christopher; Patel, Yogen; Patil, Amol; Patil, Manasi; Pawlak, Mikolaj; Payoux, Pierre; Pearson, Jim; Pell, Gaby; Peng, Yahong; Pennec, Xavier; Pepin, Jean louis; Pereira, Francisco; Perneczky, Robert; Petitti, Diana; Petrella, Jeffrey; Peyrat, Jean-Marc; Ngoc, Phuong Trinh Pham; Phillips, Justin; Phillips, Nicole; Pian, Wen-ting; Pierson, Ronald; Piovezan, Mauro; Pipitone, Jon; Pirraglia, Elizabeth; Planes, Xavi; Podhorski, Adam; Pollari, Mika; Pomara, Nunzio; Pontecorvo, Michael; Popov, Veljko; Poppenk, Jordan; Posner, Holly; Potkin, Steven; Potter, Guy; Potter, Elizabeth; Poulin, Stephane; Prastawa, Marcel; Prince, Jerry; Priya, Anandh; Pruessner, Jens; Qiu, Wendy; Qu, Annie; Qualls, Constance Dean; Quarg, Peter; Quinlan, Judith; Rabbia, Michael; Rajagovindan, Rajasimhan; Rajeesh, Rajeesh; Rallabandi, V. P. Subramanyam; Ramadubramani, Vanamamalai; Ramage, Amy; Ramirez, Alfredo; Randolph, Chrstopher; Rao, Anil; Rao, Hengyi; Rao, Divya; Raubertas, Richard; Ray, Debashis; Razak, Hana; Reed, Bruce; Reid, Andrew; Reihac, Anthonin; Reiner, Peggy; Reinsberger, Claus; Restrepo, Lucas; Retico, Alessandra; Rhatigan, Lewis; Rhinn, Herve; Rhoades, Earl; Ribbens, Annemie; Richard, Edo; Richards, John; Richter, Mirco; Riddle, William; Ridgway, Gerard; Ries, Michele; Ringman, John; Rischall, Matt; Rizk-Jackson, Angela; Rizzi, Massimo; Robieson, Weining; Rodriguez, Laura; Rodriguez-Vieitez, Elena; Rogalski, Emily; Rogers, Elizabeth; Balderrama, Javier Rojas; Rokicki, Jaroslav; Romero, Klaus; Rorden, Chris; Rosand, Jonathan; Rosen, Ori; Rosenberg, Paul; Roubini, Eli; Rousseau, François; Rowe, Christopher; Rubin, Daniel; Rubright, Jonathan; Rucinski, Marek; Ruiz, Agustin; Rulseh, Aaron; Rusinek, Henry; Ryan, Laurie; Saad, Ahmed; Sabuncu, Mert; Sahuquillo, Juan; Said, Yasmine; Saito, Naomi; Sakata, Muneyuki; Salama, Mahetab; Salazar, Diego; Salter, Hugh; Saman, Sudad; Sanchez, Luciano; Sanders, Elizabeth; Sankar, Tejas; Santhamma, Sindhumol; Sarnel, Haldun; Sasaki, Toshiaki; Sasaya, Tenta; Sato, Hajime; Sattlecker, Martina; Saumier, Daniel; Savio, Alexandre; Saykin, Andrew; Scanlon, Blake; Scharre, Douglas; Schegerin, Marc; Schmand, Ben; Schmansky, Nick; Schmidt-Wilcke, Tobias; Schramm, Hauke; Schuerch, Markus; Schwartz, Craig; Schwartz, Eben; Schwarz, Adam; Schwarz, John; Selnes, Per; Sembritzki, Klaus; Senjem, Matthew; Sevigny, Jeffrey; Sfikas, Giorgos; Sghedoni, Roberto; Shah, Said Khalid; Shahbaba, Babak; Shams, Soheil; Shankle, William; Shattuck, David; Shaw, Leslie; Sheela, Jaba; Shen, Jie; Shen, Qi; Shen, Weijia; Shen, Qian; Shera, David; Sherman, John; Sherva, Richard; Shi, Jie; Shi, Yonggang; Shi, Feng; Shokouhi, Sepideh; Shukla, Vinay; Shulman, Joshua; Sideris, Konstantinos; Siegel, Rene; Silveira, Margarida; Silverman, Daniel; Sim, Ida; Simak, Alex; Simmons, Andy; Simoes, Rita; Simon, Adam; Simon, Melvin; Simpson, Ivor; Singh, Nikhil; Singh, Simer Preet; Sinha, Neelam; Siuciak, Judy; Sjögren, Niclas; Skinner, Jeannine; Smith, Michael; Smith, Charles; Smyth, Timothy; Snow, Sarah; Snyder, Peter; Soares, Holly; Soldan, Anja; Soldea, Octavian; Solomon, Alan; Solomon, Paul; Som, Subhojit; Song, Zhuang; Song, Shide; Sosova, Iveta; Soydemir, Melih; Spampinato, Maria Vittoria; Speier, William; Sperling, Reisa; Renãâ, Spiegel; Spies, Lothar; Springate, Beth; Staff, Roger; Steffener, Jason; Stern, Yaakov; Stokman, Harro; Straw, Jack; Stricker, Nikki; Stühler, Elisabeth; Styren, Scot; Subramanian, Vijayalakshmi; Suen, Summit; Sugishita, Morihiro; Sukkar, Rafid; Sun, Ying; Sun, Jia; Sun, Yu; Sundell, Karen; Suzuki, Akiyuki; Svetnik, Vladimir; Swan, Melanie; Symons, Sean; Szigeti, Kinga; Szoeke, Cassandra; Sørensen, Lauge; Genish, T.; Takahasi, Tetsuhiko; Takeuchi, Tomoko; Tanaka, Shoji; Tanaka, Rie; Tanchi, Chaturaphat; Tancredi, Daniel; Tang, Qi; Tarnow, Eugen; Tartaglia, Maria Carmela; Tarver, Erika; Tassy, Dominique; Tauber, Clovis; Taylor-Reinwald, Lisa; Teipel, Stefan; Teng, Edmond; Terriza, Felipe; Thambisetty, Madhav; Thames, April; Thatavarti, Raja Sekhar; Thiele, Frank; Thomas, Charlene; Thomas, Ronald; Thomas, Benjamin; Thompson, Paul; Thompson, Wesley; Thornton-Wells, Tricia; Thorvaldsson, Valgeir; Thurfjell, Lennart; Tokuda, Takahiko; Toledo, Juan B.; Tölli, Tuomas; Toma, Ahmed; Tomita, Naoki; Toro, Roberto; Torrealdea, Patxi; Tosto, Giuseppe; Tosun, Duygu; Tousian, Mona; Toussaint, Paule; Toyoshiba, Hiroyoshi; Tractenberg, Rochelle E.; Triggs, Tyler; Trittschuh, Emily; Trojanowski, John; Trotta, Gabriele; Huu, Tram Truong; Truran, Diana; Tsanas, Athanasios; Tsang, Candy; Tufail, Ahsan; Tung, Joyce; Turken, And; Ueda, Yoji; Uematsu, Daisuke; Ullrich, Lauren; Venkataraju, Kannan Umadevi; Umar, Nisser; Ungar, Leo; Uzunbas, Gokhan; van de Nes, Joseph; van der Brug, Marcel; van der Lijn, Fedde; van Hecke, Wim; van Horn, John; van Leemput, Koen; van Train, Kenneth; Varkuti, Balint; Vasanawala, Minal; Veeraraghavan, Harini; Vemuri, Prashanthi; Verma, Manish; Videbaek, Charlotte; Vidoni, Eric; Villanueva-Meyer, Javier; Vinyes, Georgina; Visser, Pieter Jelle; Vitek, Michael; Vogel, Simon; Voineskos, Aristotle; Vos, Stephanie; Vounou, Maria; Wade, Sara; Walsh, Alexander; Wan, Hong; Wang, Tianyao; Wang, Yongmei Michelle; Wang, Wei; Wang, Angela; Wang, Song; Wang, Lubin; Wang, Li; Wang, Yaping; Wang, Li-San; Wang, Lei; Wang, Alex; Wang, Yue; Wang, Xu; Wang, Ze; Wang, Tiger; Ward, Michael; Ward, Andrew; Watanabe, Toshiyuki; Watson, David; Webb, David; Wefel, Jeffrey; Weiner, Michael; Westlye, Lars T.; Wheland, David; Whitcher, Brandon; White, Brooke; Whitlow, Christopher; Wilhelmsen, Kirk; Wilmot, Beth; Wilson, Lorraine; Wimsatt, Matt; Wingo, Thomas; Wirth, Miranka; Wishart, Heather; Wiste, Heather; Wolf, Henrike; Wolke, Ira; Wolz, Robin; Wong, Koon; Woo, Jongwook; Woo, Ellen; Woods, Lynn; Worth, Andrew; Wu, Yanjun; Wu, Liang; Wu, Ellen; Wyman, Bradley; Xiao, Guanghua; Xie, Sharon; Xu, Ye; Xu, Yi-Zheng; Xu, Guofan; Xu, Steven; Xu, Shunbin; Xu, Jun; Yamada, Tomoko; Yamashita, Fumio; Yan, Yunyi; Yan, Pingkun; Yang, Chung-Yi; Yang, Zijiang; Yang, Edward; Yang, Guang; Yang, Wenlu; Yang, Eric; Yank, Hyun Duk; Yang, Jinzhong; Yassa, Michael; Yavorsky, Christian; Ye, Byoung Seok; Ye, Liang; Ye, Jong; Yee, Laura; Ying, Song; Yokoyama, Takao; Young, Stewart; Young, Jonathan; Younhyun, Jung; Yu, Dongchuan; Yu, Shiwei; Yu, C. Q.; Yu, Peng; Yuan, Ying; Yuan, Kai; Yuan, Guihong; Yuen, Bob; Yushkevich, Paul; Zaborszky, Laszlo; Zagorodnov, Vitali; Zagorski, Michael; Zahodne, Laura; Zarei, Mojtaba; Zawadzki, Rezi; Zeitzer, Jamie; Zelinski, Elizabeth; Zeskind, Benjamin; Zhan, Shu; Zhang, Jing; Zhang, Lijun; Zhang, Zhiguo; Zhang, Linda; Zhang, Zhe; Zhang, Daoqiang; Zhang, Huixiong; Zhang, Xin; Zhang, Tianhao; Zhang, Ping; Zhao, Jim; Zhao, Qinying; Zhao, Peng; Zhen, Xiantong; Zhijun, Yao; Zhou, Luping; Zhou, Bin; Zhou, Yongxia; Zhou, Sheng; Zhu, Hongtu; Zhu, Wen; Zhu, Wanlin; Zhu, Xuyan; Ziegler, Gabriel; Zilka, Samantha; Zisserman, Andrew; Zito, Giancarlo; Zu, Chen; Zulfigar, Annam

    2012-01-01

    The hippocampus is affected at an early stage in the development of Alzheimer's disease (AD). With the use of structural magnetic resonance (MR) imaging, we can investigate the effect of AD on the morphology of the hippocampus. The hippocampal shape variations among a population can be usually

  9. On Characterizing Particle Shape

    Science.gov (United States)

    Ennis, Bryan J.; Rickman, Douglas; Rollins, A. Brent; Ennis, Brandon

    2014-01-01

    It is well known that particle shape affects flow characteristics of granular materials, as well as a variety of other solids processing issues such as compaction, rheology, filtration and other two-phase flow problems. The impact of shape crosses many diverse and commercially important applications, including pharmaceuticals, civil engineering, metallurgy, health, and food processing. Two applications studied here include the dry solids flow of lunar simulants (e.g. JSC-1, NU-LHT-2M, OB-1), and the flow properties of wet concrete, including final compressive strength. A multi-dimensional generalized, engineering method to quantitatively characterize particle shapes has been developed, applicable to both single particle orientation and multi-particle assemblies. The two-dimension, three dimension inversion problem is also treated, and the application of these methods to DEM model particles will be discussed. In the case of lunar simulants, flow properties of six lunar simulants have been measured, and the impact of particle shape on flowability - as characterized by the shape method developed here -- is discussed, especially in the context of three simulants of similar size range. In the context of concrete processing, concrete construction is a major contributor to greenhouse gas production, of which the major contributor is cement binding loading. Any optimization in concrete rheology and packing that can reduce cement loading and improve strength loading can also reduce currently required construction safety factors. The characterization approach here is also demonstrated for the impact of rock aggregate shape on concrete slump rheology and dry compressive strength.

  10. Shapes of interacting RNA complexes

    DEFF Research Database (Denmark)

    Fu, Benjamin Mingming; Reidys, Christian

    2014-01-01

    Shapes of interacting RNA complexes are studied using a filtration via their topological genus. A shape of an RNA complex is obtained by (iteratively) collapsing stacks and eliminating hairpin loops.This shape-projection preserves the topological core of the RNA complex and for fixed topological...... genus there are only finitely many such shapes. Our main result is a new bijection that relates the shapes of RNA complexes with shapes of RNA structures. This allows to compute the shape polynomial of RNA complexes via the shape polynomial of RNA structures. We furthermore present a linear time uniform...... sampling algorithm for shapes of RNA complexes of fixed topological genus....

  11. Microenvironmental variation in preassay rearing conditions can ...

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Genetics; Volume 85; Issue 1. Microenvironmental variation in preassay rearing conditions can lead to anomalies in the measurement of life-history traits. Sutirth Dey Snigdhadip Dey J. Mohan Amitabh Joshi. Research Note Volume 85 Issue 1 April 2006 pp 53-56 ...

  12. A variational principle for vector equilibrium problems

    Indian Academy of Sciences (India)

    Home; Journals; Proceedings – Mathematical Sciences; Volume 111; Issue 4. A Variational Principle for Vector Equilibrium Problems. K R Kazmi. Volume 111 Issue 4 November 2001 pp 465-470. Fulltext. Click here to view fulltext PDF. Permanent link: http://www.ias.ac.in/article/fulltext/pmsc/111/04/0465-0470. Keywords.

  13. Shape preferred orientation of iron grains compatible with Earth's uppermost inner core hemisphericity

    Science.gov (United States)

    Calvet, Marie; Margerin, Ludovic

    2018-01-01

    Constraining the possible patterns of iron fabrics in the Earth's Uppermost Inner Core (UIC) is key to unravel the mechanisms controlling its growth and dynamics. In the framework of crystalline micro-structures composed of ellipsoidal, aligned grains, we discuss possible textural models of UIC compatible with observations of P-wave attenuation and velocity dispersion. Using recent results from multiple scattering theory in textured heterogeneous materials, we compute the P-wave phase velocity and scattering attenuation as a function of grain volume, shape, and orientation wrt to the propagation direction of seismic P-waves. Assuming no variations of the grain volume between the Eastern and Western hemisphere, we show that two families of texture are compatible with the degree-one structure of the inner core as revealed by the positive correlation between seismic velocity and attenuation. (1) Strong flattening of grains parallel to the Inner Core Boundary in the Western hemisphere and weak anisometry in the Eastern hemisphere. (2) Strong radial elongation of grains in the Western hemisphere and again weak anisometry in the Eastern hemisphere. Both textures can quantitatively explain the seismic data in a limited range of grain volumes. Furthermore, the velocity and attenuation anisotropy locally observed under Africa demands that the grains be locally elongated in the direction of Earth's meridians. Our study demonstrates that the hemispherical seismic structure of UIC can be entirely explained by changes in the shape and orientation of grains, thereby offering an alternative to changes in grain volumes. In the future, our theoretical toolbox could be used to systematically test the compatibility of textures predicted by geodynamical models with seismic observations.

  14. Computed tomographic morphometry of tympanic bulla shape and position in brachycephalic and mesaticephalic dog breeds.

    Science.gov (United States)

    Mielke, Ben; Lam, Richard; Ter Haar, Gert

    2017-09-01

    Anatomic variations in skull morphology have been previously described for brachycephalic dogs; however there is little published information on interbreed variations in tympanic bulla morphology. This retrospective observational study aimed to (1) provide detailed descriptions of the computed tomographic (CT) morphology of tympanic bullae in a sample of dogs representing four brachycephalic breeds (Pugs, French Bulldogs, English Bulldog, and Cavalier King Charles Spaniels) versus two mesaticephalic breeds (Labrador retrievers and Jack Russell Terriers); and (2) test associations between tympanic bulla morphology and presence of middle ear effusion. Archived head CT scans for the above dog breeds were retrieved and a single observer measured tympanic bulla shape (width:height ratio), wall thickness, position relative to the temporomandibular joint, and relative volume (volume:body weight ratio). A total of 127 dogs were sampled. Cavalier King Charles Spaniels had significantly flatter tympanic bullae (greater width:height ratios) versus Pugs, English Bulldogs, Labrador retrievers, and Jack Russell terriers. French Bulldogs and Pugs had significantly more overlap between tympanic bullae and temporomandibular joints versus other breeds. All brachycephalic breeds had significantly lower tympanic bulla volume:weight ratios versus Labrador retrievers. Soft tissue attenuating material (middle ear effusion) was present in the middle ear of 48/100 (48%) of brachycephalic breeds, but no significant association was found between tympanic bulla CT measurements and presence of this material. Findings indicated that there are significant interbreed variations in tympanic bulla morphology, however no significant relationship between tympanic bulla morphology and presence of middle ear effusion could be identified. © 2017 American College of Veterinary Radiology.

  15. Shape Abnormalities of the Caudate Nucleus Correlate with Poorer Gait and Balance

    DEFF Research Database (Denmark)

    Macfarlane, Matthew D; Looi, Jeffrey C L; Walterfang, Mark

    2015-01-01

    found to correlate with poorer performance on measures of gait and balance. This study aimed to determine whether striatal volume and shape changes were correlated with gait dysfunction. METHODS: Magnetic resonance imaging scans and clinical gait/balance data (scores from the Short Physical Performance...... published method and volumes calculated. The relationships between volume and physical performance on the SPPB were investigated with shape analysis using the spherical harmonic shape description toolkit. RESULTS: There was no correlation between the severity of WMHs and striatal volumes. Caudate nuclei...... volume correlated with performance on the SPPB at baseline but not at follow-up, with subsequent shape analysis showing left caudate changes occurred in areas corresponding to inputs of the dorsolateral prefrontal, premotor, and motor cortex. There was no correlation between putamen volumes...

  16. Variations in optical coherence tomography resolution and uniformity: a multi-system performance comparison

    Science.gov (United States)

    Fouad, Anthony; Pfefer, T. Joshua; Chen, Chao-Wei; Gong, Wei; Agrawal, Anant; Tomlins, Peter H.; Woolliams, Peter D.; Drezek, Rebekah A.; Chen, Yu

    2014-01-01

    Point spread function (PSF) phantoms based on unstructured distributions of sub-resolution particles in a transparent matrix have been demonstrated as a useful tool for evaluating resolution and its spatial variation across image volumes in optical coherence tomography (OCT) systems. Measurements based on PSF phantoms have the potential to become a standard test method for consistent, objective and quantitative inter-comparison of OCT system performance. Towards this end, we have evaluated three PSF phantoms and investigated their ability to compare the performance of four OCT systems. The phantoms are based on 260-nm-diameter gold nanoshells, 400-nm-diameter iron oxide particles and 1.5-micron-diameter silica particles. The OCT systems included spectral-domain and swept source systems in free-beam geometries as well as a time-domain system in both free-beam and fiberoptic probe geometries. Results indicated that iron oxide particles and gold nanoshells were most effective for measuring spatial variations in the magnitude and shape of PSFs across the image volume. The intensity of individual particles was also used to evaluate spatial variations in signal intensity uniformity. Significant system-to-system differences in resolution and signal intensity and their spatial variation were readily quantified. The phantoms proved useful for identification and characterization of irregularities such as astigmatism. Our multi-system results provide evidence of the practical utility of PSF-phantom-based test methods for quantitative inter-comparison of OCT system resolution and signal uniformity. PMID:25071949

  17. Shape and topology optimization of enzymatic microreactors

    DEFF Research Database (Denmark)

    Pereira Rosinha, Ines

    Structural optimization methods have been used by mechanical and civil engineers over the yearsto find the optimal structures. Structural optimization is a series of computational techniqueswhich include shape and topology optimization. Shape optimization is directly applied to theboundaries...... in a chemical process do not always yield in the best reaction conditions.This thesis develops an innovative application of topology and shape optimization methods to achemical engineering problem. The main goal is to design a reactor according to the limitations of the reaction system by modifying the reactor...... froma vector which sets the variation limits. Subsequently, the same coupled routine between ANSYS CFX® and MATLAB® is applied to topology optimization. The method was used as a novel technique to computationally discover the best spatial distribution of an enzyme inside microreactors. Usually...

  18. The Dynamics of Shape

    CERN Document Server

    Gomes, Henrique

    2011-01-01

    This thesis consists of two parts, connected by one central theme: the dynamics of the "shape of space". The first part of the thesis concerns the construction of a theory of gravity dynamically equivalent to general relativity (GR) in 3+1 form (ADM). What is special about this theory is that it does not possess foliation invariance, as does ADM. It replaces that "symmetry" by another: local conformal invariance. In so doing it more accurately reflects a theory of the "shape of space", giving us reason to call it \\emph{shape dynamics} (SD). In the first part we will try to present some of the highlights of results so far, and indicate what we can and cannot do with shape dynamics. Because this is a young, rapidly moving field, we have necessarily left out some interesting new results which are not yet in print and were developed alongside the writing of the thesis. The second part of the thesis will develop a gauge theory for "shape of space"--theories. To be more precise, if one admits that the physically re...

  19. SHAPE selection (SHAPES) enrich for RNA structure signal in SHAPE sequencing-based probing data

    DEFF Research Database (Denmark)

    Poulsen, Line Dahl; Kielpinski, Lukasz Jan; Salama, Sofie R

    2015-01-01

    transcriptase. Here, we introduce a SHAPE Selection (SHAPES) reagent, N-propanone isatoic anhydride (NPIA), which retains the ability of SHAPE reagents to accurately probe RNA structure, but also allows covalent coupling between the SHAPES reagent and a biotin molecule. We demonstrate that SHAPES...

  20. Net Shape Technology in Aerospace Structures. Volume 1.

    Science.gov (United States)

    1986-11-01

    composed o f man \\ smll decta-ilI parIt s maid cI n sta I f: J1r om o ne p re cisi o n ’or-g In g. The cst I im tcd savNIn)g s -Ic h i c \\ e d M...metal I I orgy materialIs baised onl ra pid sol idi ficatIIon tech nology . Conser\\ at I nn ofC miatcr Ial s i n its own ri gh t is not genicrall a 1 1P r

  1. Shape memory polymer medical device

    Science.gov (United States)

    Maitland, Duncan [Pleasant Hill, CA; Benett, William J [Livermore, CA; Bearinger, Jane P [Livermore, CA; Wilson, Thomas S [San Leandro, CA; Small, IV, Ward; Schumann, Daniel L [Concord, CA; Jensen, Wayne A [Livermore, CA; Ortega, Jason M [Pacifica, CA; Marion, III, John E.; Loge, Jeffrey M [Stockton, CA

    2010-06-29

    A system for removing matter from a conduit. The system includes the steps of passing a transport vehicle and a shape memory polymer material through the conduit, transmitting energy to the shape memory polymer material for moving the shape memory polymer material from a first shape to a second and different shape, and withdrawing the transport vehicle and the shape memory polymer material through the conduit carrying the matter.

  2. Some New Concepts of Shape Memory Effect of Polymers

    Directory of Open Access Journals (Sweden)

    Abbas Tcharkhtchi

    2014-04-01

    Full Text Available In this study some new concepts regarding certain aspects related to shape memory polymers are presented. A blend of polylactic acid (PLA (80% and polybutylene succinate (PBS (20% was prepared first by extrusion, then by injection molding to obtain the samples. Tensile, stress-relaxation and recovery tests were performed on these samples at 70 °C. The results indicated that the blend can only regain 24% of its initial shape. It was shown that, this partial shape memory effect could be improved by successive cycles of shape memory tests. After a fourth cycle, the blend is able to regain 82% of its shape. These original results indicated that a polymer without (or with partial shape memory effect may be transformed into a shape memory polymer without any chemical modification. In this work, we have also shown the relationship between shape memory and property memory effect. Mono and multi-frequency DMA (dynamic mechanical analyzer tests on virgin and 100% recovered samples of polyurethane (PU revealed that the polymer at the end of the shape memory tests regains 100% of its initial form without regaining some of its physical properties like glass transition temperature, tensile modulus, heat expansion coefficient and free volume fraction. Shape memory (with and without stress-relaxation tests were performed on the samples in order to show the role of residual stresses during recovery tests. On the basis of the results we have tried to show the origin of the driving force responsible for shape memory effect.

  3. Laser beam shaping techniques

    Energy Technology Data Exchange (ETDEWEB)

    DICKEY,FRED M.; WEICHMAN,LOUIS S.; SHAGAM,RICHARD N.

    2000-03-16

    Industrial, military, medical, and research and development applications of lasers frequently require a beam with a specified irradiance distribution in some plane. A common requirement is a laser profile that is uniform over some cross-section. Such applications include laser/material processing, laser material interaction studies, fiber injection systems, optical data image processing, lithography, medical applications, and military applications. Laser beam shaping techniques can be divided into three areas: apertured beams, field mappers, and multi-aperture beam integrators. An uncertainty relation exists for laser beam shaping that puts constraints on system design. In this paper the authors review the basics of laser beam shaping and present applications and limitations of various techniques.

  4. Genetic Variation in the Catechol-O-Methyl Transferase Val108/158Met Is Linked to the Caudate and Posterior Cingulate Cortex Volume in Healthy Subjects: Voxel-Based Morphometry Analysis of Brain Magnetic Resonance Imaging.

    Directory of Open Access Journals (Sweden)

    Keita Watanabe

    Full Text Available The effect of the catechol-O-methyltransferase (COMT Val158Met polymorphism on brain morphology has been investigated but remains controversial. We hypothesized that a comparison between Val/Val and Val/Met individuals, which may represent the most different combinations concerning the effects of the COMT genotype, may reveal new findings. We investigated the brain morphology using 3-Tesla magnetic resonance imaging in 27 Val/Val and 22 Val/Met individuals. Voxel-based morphometry revealed that the volumes of the bilateral caudate and posterior cingulate cortex were significantly smaller in Val/Val individuals than in Val/Met individuals [right caudate: false discovery rate (FDR-corrected p = 0.048; left caudate: FDR-corrected p = 0.048; and bilateral posterior cingulate cortex: FDR-corrected p = 0.048]. This study demonstrates that interacting functional variants of COMT affect gray matter regional volumes in healthy subjects.

  5. Quantifying the effect of corrective surgery for trigonocephaly: A non-invasive, non-ionizing method using three-dimensional handheld scanning and statistical shape modelling.

    Science.gov (United States)

    Rodriguez-Florez, Naiara; Göktekin, Özge K; Bruse, Jan L; Borghi, Alessandro; Angullia, Freida; Knoops, Paul G M; Tenhagen, Maik; O'Hara, Justine L; Koudstaal, Maarten J; Schievano, Silvia; Jeelani, N U Owase; James, Greg; Dunaway, David J

    2017-03-01

    Trigonocephaly in patients with metopic synostosis is corrected by fronto-orbital remodelling (FOR). The aim of this study was to quantitatively assess aesthetic outcomes of FOR by capturing 3D forehead scans of metopic patients pre- and post-operatively and comparing them with controls. Ten single-suture metopic patients undergoing FOR and 15 age-matched non-craniosynostotic controls were recruited at Great Ormond Street Hospital for Children (UK). Scans were acquired with a three-dimensional (3D) handheld camera and post-processed combining 3D imaging software. 3D scans were first used for cephalometric measurements. Statistical shape modelling was then used to compute the 3D mean head shapes of the three groups (FOR pre-op, post-op and controls). Head shape variations were described via principal component analysis (PCA). Cephalometric measurements showed that FOR significantly increased the forehead volume and improved trigonocephaly. This improvement was supported visually by pre- and post-operative computed mean 3D shapes and numerically by PCA (p 3D scanning followed by 3D statistical shape modelling enabled the 3D comparison of forehead shapes of metopic patients and non-craniosynostotic controls, and demonstrated that the adopted FOR technique was successful in correcting bitemporal narrowing but overcorrected the rounding of the forehead. Copyright © 2017 The Author(s). Published by Elsevier Ltd.. All rights reserved.

  6. Defining the "Hostile Pelvis" for Intensity Modulated Radiation Therapy: The Impact of Anatomic Variations in Pelvic Dimensions on Dose Delivered to Target Volumes and Organs at Risk in Patients With High-Risk Prostate Cancer Treated With Whole Pelvic Radiation Therapy.

    Science.gov (United States)

    Yirmibeşoğlu Erkal, Eda; Karabey, Sinan; Karabey, Ayşegül; Hayran, Mutlu; Erkal, Haldun Şükrü

    2015-07-15

    The aim of this study was to evaluate the impact of variations in pelvic dimensions on the dose delivered to the target volumes and the organs at risk (OARs) in patients with high-risk prostate cancer (PCa) to be treated with whole pelvic radiation therapy (WPRT) in an attempt to define the hostile pelvis in terms of intensity modulated radiation therapy (IMRT). In 45 men with high-risk PCa to be treated with WPRT, the target volumes and the OARs were delineated, the dose constraints for the OARs were defined, and treatment plans were generated according to the Radiation Therapy Oncology Group 0924 protocol. Six dimensions to reflect the depth, width, and height of the bony pelvis were measured, and 2 indexes were calculated from the planning computed tomographic scans. The minimum dose (Dmin), maximum dose (Dmax), and mean dose (Dmean) for the target volumes and OARs and the partial volumes of each of these structures receiving a specified dose (VD) were calculated from the dose-volume histograms (DVHs). The data from the DVHs were correlated with the pelvic dimensions and indexes. According to an overall hostility score (OHS) calculation, 25 patients were grouped as having a hospitable pelvis and 20 as having a hostile pelvis. Regarding the OHS grouping, the DVHs for the bladder, bowel bag, left femoral head, and right femoral head differed in favor of the hospitable pelvis group, and the DVHs for the rectum differed for a range of lower doses in favor of the hospitable pelvis group. Pelvimetry might be used as a guide to define the challenging anatomy or the hostile pelvis in terms of treatment planning for IMRT in patients with high-risk PCa to be treated with WPRT. Copyright © 2015 Elsevier Inc. All rights reserved.

  7. Novel application of confocal laser scanning microscopy and 3D volume rendering toward improving the resolution of the fossil record of charcoal.

    Directory of Open Access Journals (Sweden)

    Claire M Belcher

    Full Text Available Variations in the abundance of fossil charcoals between rocks and sediments are assumed to reflect changes in fire activity in Earth's past. These variations in fire activity are often considered to be in response to environmental, ecological or climatic changes. The role that fire plays in feedbacks to such changes is becoming increasingly important to understand and highlights the need to create robust estimates of variations in fossil charcoal abundance. The majority of charcoal based fire reconstructions quantify the abundance of charcoal particles and do not consider the changes in the morphology of the individual particles that may have occurred due to fragmentation as part of their transport history. We have developed a novel application of confocal laser scanning microscopy coupled to image processing that enables the 3-dimensional reconstruction of individual charcoal particles. This method is able to measure the volume of both microfossil and mesofossil charcoal particles and allows the abundance of charcoal in a sample to be expressed as total volume of charcoal. The method further measures particle surface area and shape allowing both relationships between different size and shape metrics to be analysed and full consideration of variations in particle size and size sorting between different samples to be studied. We believe application of this new imaging approach could allow significant improvement in our ability to estimate variations in past fire activity using fossil charcoals.

  8. Surface displacement based shape analysis of central brain structures in preterm-born children

    Science.gov (United States)

    Garg, Amanmeet; Grunau, Ruth E.; Popuri, Karteek; Miller, Steven; Bjornson, Bruce; Poskitt, Kenneth J.; Beg, Mirza Faisal

    2016-03-01

    Many studies using T1 magnetic resonance imaging (MRI) data have found associations between changes in global metrics (e.g. volume) of brain structures and preterm birth. In this work, we use the surface displacement feature extracted from the deformations of the surface models of the third ventricle, fourth ventricle and brainstem to capture the variation in shape in these structures at 8 years of age that may be due to differences in the trajectory of brain development as a result of very preterm birth (24-32 weeks gestation). Understanding the spatial patterns of shape alterations in these structures in children who were born very preterm as compared to those who were born at full term may lead to better insights into mechanisms of differing brain development between these two groups. The T1 MRI data for the brain was acquired from children born full term (FT, n=14, 8 males) and preterm (PT, n=51, 22 males) at age 8-years. Accurate segmentation labels for these structures were obtained via a multi-template fusion based segmentation method. A high dimensional non-rigid registration algorithm was utilized to register the target segmentation labels to a set of segmentation labels defined on an average-template. The surface displacement data for the brainstem and the third ventricle were found to be significantly different (p MRI data and reveal shape changes that may be due to preterm birth.

  9. Effect of particle shape on mechanical behaviors of rocks: a numerical study using clumped particle model.

    Science.gov (United States)

    Rong, Guan; Liu, Guang; Hou, Di; Zhou, Chuang-Bing

    2013-01-01

    Since rocks are aggregates of mineral particles, the effect of mineral microstructure on macroscopic mechanical behaviors of rocks is inneglectable. Rock samples of four different particle shapes are established in this study based on clumped particle model, and a sphericity index is used to quantify particle shape. Model parameters for simulation in PFC are obtained by triaxial compression test of quartz sandstone, and simulation of triaxial compression test is then conducted on four rock samples with different particle shapes. It is seen from the results that stress thresholds of rock samples such as crack initiation stress, crack damage stress, and peak stress decrease with the increasing of the sphericity index. The increase of sphericity leads to a drop of elastic modulus and a rise in Poisson ratio, while the decreasing sphericity usually results in the increase of cohesion and internal friction angle. Based on volume change of rock samples during simulation of triaxial compression test, variation of dilation angle with plastic strain is also studied.

  10. Effective response of classical, auxetic and chiral magnetoelastic materials by use of a new variational principle

    Science.gov (United States)

    Danas, K.

    2017-08-01

    This work provides a rigorous analysis of the effective response, i.e., average magnetization and magnetostriction, of magnetoelastic composites that are subjected to overall magnetic and mechanical loads. It clarifies the differences between a coupled magnetomechanical analysis in which one applies a Eulerian (current) magnetic field and an electroactive one where the Lagrangian (reference) electric field is usually applied. For this, we propose an augmented vector potential variational formulation to carry out numerical periodic homogenization studies of magnetoelastic solids at finite strains and magnetic fields. We show that the developed variational principle can be used for bottom-up design of microstructures with desired magnetomechanical coupling by properly canceling out the macro-geometry and specimen shape effects. To achieve that, we properly treat the average Maxwell stresses arising from the medium surrounding the magnetoelastic representative volume element (RVE), while at the same time we impose a uniform average Eulerian and not Lagrangian magnetic field. The developed variational principle is then used to study a large number of ideal as well as more realistic two-dimensional microstructures. We study the effect of particle volume fraction, particle distribution and particle shape and orientation upon the effective magnetoelastic response at finite strains. We consider also unstructured isotropic microstructures based on random adsorption algorithms and we carry out a convergence study of the representativity of the proposed unit cells. Finally, three-phase two-dimensional auxetic microstructures are analyzed. The first consists of a periodic distribution of voids and particle chains in a polymer matrix, while the second takes advantage of particle shape and chirality to produce negative and positive swelling by proper change of the chirality and the applied magnetic field.

  11. Shape Restoration by Active Self-Assembly

    Directory of Open Access Journals (Sweden)

    D. Arbuckle

    2005-01-01

    Full Text Available Shape restoration is defined as the problem of constructing a desired, or goal, solid shape Sg by growing an initial solid Si, which is a subset of the goal but is otherwise unknown. This definition attempts to capture abstractly a situation that often arises in the physical world when a solid object loses its desired shape due to wear and tear, corrosion or other phenomena. For example, if the top of the femur becomes distorted, the hip joint no longer functions properly and may have to be replaced surgically. Growing it in place back to its original shape would be an attractive alternative to replacement. This paper presents a solution to the shape restoration problem by using autonomous assembly agents (robots that self-assemble to fill the volume between Sg and Si. If the robots have very small dimension (micro or nano, the desired shape is approximated with high accuracy. The assembly agents initially execute a random walk. When two robots meet, they may exchange a small number of messages. The robot behavior is controlled by a finite state machine with a small number of states. Communication contact models chemical communication, which is likely to be the medium of choice for robots at the nanoscale, while small state and small messages are limitations that also are expected of nanorobots. Simulations presented here show that swarms of such robots organize themselves to achieve shape restoration by using distributed algorithms. This is one more example of an interesting geometric problem that can be solved by the Active Self-Assembly paradigm introduced in previous papers by the authors.

  12. Shaping Adolescent Gambling Behavior.

    Science.gov (United States)

    Arcuri, Alan F.; And Others

    1985-01-01

    Surveyed the incidence of casino gambling by adolescents. Results indicated that 64 percent of the students at one Atlantic City high school had gambled at the casinos. The dangers of shaping compulsive gambling behavior through societal acceptance of legalized gambling are discussed. (Author/BL)

  13. Shape Up Europe

    DEFF Research Database (Denmark)

    Simovska, Venka; Jensen, Bjarne Bruun

    "Shape Up: a School Community Approach to Influencing the Determinants of Childhood Overweight and Obesity, Lessons Learnt" is a report that aims to provide a synthesis of the project overall evaluation documentation, with a view to systematically review and discuss lessons learnt, and to suggest...... recommendations concerning future practice and policy in the area of preventing childhood overweight and obesity....

  14. Aerodynamically shaped vortex generators

    DEFF Research Database (Denmark)

    Hansen, Martin Otto Laver; Velte, Clara Marika; Øye, Stig

    2016-01-01

    An aerodynamically shaped vortex generator has been proposed, manufactured and tested in a wind tunnel. The effect on the overall performance when applied on a thick airfoil is an increased lift to drag ratio compared with standard vortex generators. Copyright © 2015 John Wiley & Sons, Ltd....

  15. Trends Shaping Education 2010

    Science.gov (United States)

    OECD Publishing (NJ3), 2010

    2010-01-01

    "Trends Shaping Education 2010" brings together evidence showing the effects on education of globalisation, social challenges, changes in the workplace, the transformation of childhood, and ICT. To make the content accessible, each trend is presented on a double page, containing an introduction, two charts with brief descriptive text and a set of…

  16. How life shaped Earth.

    Science.gov (United States)

    Gross, Michael

    2015-10-05

    Earth is much more complex than all the other solar system objects that we know. Thanks to its rich and diverse geology, our planet can offer habitats to a wide range of living species. Emerging insights suggest that this is not just a happy coincidence, but that life itself has in many ways helped to shape the planet.

  17. Shaping Faster Question Answering.

    Science.gov (United States)

    Brooks, Lloyd O.

    To test a hypothesis that question answering speed and accuracy can be increased by an automated shaping procedure, a film, "The Analysis of Behavior," was presented individually by a teaching machine during twice-per-week sessions to one high school student and 12 junior college students. Six of the students were informed of monetary rewards for…

  18. Tornado-Shaped Curves

    Science.gov (United States)

    Martínez, Sol Sáez; de la Rosa, Félix Martínez; Rojas, Sergio

    2017-01-01

    In Advanced Calculus, our students wonder if it is possible to graphically represent a tornado by means of a three-dimensional curve. In this paper, we show it is possible by providing the parametric equations of such tornado-shaped curves.

  19. Analysis of () Line Shape

    Indian Academy of Sciences (India)

    The line shape is also simulated by the Monte–Carlo method, the molecular dissociation contributes to 57% neutral atoms and 53% emission intensity in front of the limiter, and 85% neutral atoms and 82% emission intensity in front of the wall. The processes of atoms and molecules influence on the energy balance is ...

  20. Bend me, shape me

    CERN Multimedia

    2002-01-01

    A Japanese team has found a way to bend and shape silicon substrates by growing a thin layer of diamond on top. The technique has been proposed as an alternative to mechanical bending, which is currently used to make reflective lenses for X-ray systems and particle physics systems (2 paragraphs).

  1. Ferromagnetic shape memory alloys

    Indian Academy of Sciences (India)

    ugc

    (sensor), magnetocaloric (refrigeration), and shape memory effect. (actuation) may be important for their future application. Magnetoresistance (8%). Giant magnetocaloric ..... Experimental studies on Ga. 2. MnNi: SEM, EDAX, DSC. T. M. = 780 K. Homogeneous, composition Ga. 1.9. Mn. 0.8. Ni. 1.02. Secondary electron ...

  2. 3D shape modeling by integration visual and tactile cues

    Science.gov (United States)

    Xiong, Hanwei; Xu, Jun; Xu, Chenxi; Pan, Ming

    2015-10-01

    With the progress in CAD (Computer Aided Design) systems, many mechanical components can be designed efficiently with high precision. But, such a system is unfit for some organic shapes, for example, a toy. In this paper, an easy way to dealing with such shapes is presented, combing visual perception with tangible interaction. The method is divided into three phases: two tangible interaction phases and one visual reconstruction. In the first tangible phase, a clay model is used to represent the raw shape, and the designer can change the shape intuitively with his hands. Then the raw shape is scanned into a digital volume model through a low cost vision system. In the last tangible phase, a desktop haptic device from SensAble is used to refine the scanned volume model and convert it into a surface model. A physical clay model and a virtual clay mode are all used in this method to deal with the main shape and the details respectively, and the vision system is used to bridge the two tangible phases. The vision reconstruction system is only made of a camera to acquire raw shape through shape from silhouettes method. All of the systems are installed on a single desktop, make it convenient for designers. The vision system details and a design example are presented in the papers.

  3. Multiscale 3-D shape representation and segmentation using spherical wavelets.

    Science.gov (United States)

    Nain, Delphine; Haker, Steven; Bobick, Aaron; Tannenbaum, Allen

    2007-04-01

    This paper presents a novel multiscale shape representation and segmentation algorithm based on the spherical wavelet transform. This work is motivated by the need to compactly and accurately encode variations at multiple scales in the shape representation in order to drive the segmentation and shape analysis of deep brain structures, such as the caudate nucleus or the hippocampus. Our proposed shape representation can be optimized to compactly encode shape variations in a population at the needed scale and spatial locations, enabling the construction of more descriptive, nonglobal, nonuniform shape probability priors to be included in the segmentation and shape analysis framework. In particular, this representation addresses the shortcomings of techniques that learn a global shape prior at a single scale of analysis and cannot represent fine, local variations in a population of shapes in the presence of a limited dataset. Specifically, our technique defines a multiscale parametric model of surfaces belonging to the same population using a compact set of spherical wavelets targeted to that population. We further refine the shape representation by separating into groups wavelet coefficients that describe independent global and/or local biological variations in the population, using spectral graph partitioning. We then learn a prior probability distribution induced over each group to explicitly encode these variations at different scales and spatial locations. Based on this representation, we derive a parametric active surface evolution using the multiscale prior coefficients as parameters for our optimization procedure to naturally include the prior for segmentation. Additionally, the optimization method can be applied in a coarse-to-fine manner. We apply our algorithm to two different brain structures, the caudate nucleus and the hippocampus, of interest in the study of schizophrenia. We show: 1) a reconstruction task of a test set to validate the expressiveness of

  4. Duality based contact shape optimization

    DEFF Research Database (Denmark)

    Vondrák, Vít; Dostal, Zdenek; Rasmussen, John

    2001-01-01

    An implementation of semi-analytic method for the sensitivity analysis in contact shape optimization without friction is described. This method is then applied to the contact shape optimization.......An implementation of semi-analytic method for the sensitivity analysis in contact shape optimization without friction is described. This method is then applied to the contact shape optimization....

  5. Capacity planning in operations producing heavy plate cut shapes

    Directory of Open Access Journals (Sweden)

    R. Lenort

    2009-07-01

    Full Text Available The present approach to capacity planning in operations producing heavy metal shapes causes problems in fulfilling the required financial and volume indexes in production, as well as in meeting the work order completion dates. The article represents the methodology for optimal production scheduling in operations producing heavy plate cut shapes, which significantly eliminates the above-mentioned problems. The methodology is based on the application Generalized Assignment Problem (GAP.

  6. Sex-related shape dimorphism in the human radiocarpal and midcarpal joints

    OpenAIRE

    Kivell, Tracy L.; Guimont, Isabelle; Wall, Christine E.

    2013-01-01

    Previous research has revealed significant size differences between human male and female carpal bones but it is unknown if there are significant shape differences as well. This study investigated sex-related shape variation and allometric patterns in five carpal bones that make up the radiocarpal and midcarpal joints in modern humans. We found that many aspects of carpal shape (76% of all variables quantified) were similar between males and females, despite variation in size. However, 10 of ...

  7. Mapping of Craniofacial Traits in Outbred Mice Identifies Major Developmental Genes Involved in Shape Determination.

    Directory of Open Access Journals (Sweden)

    Luisa F Pallares

    2015-11-01

    Full Text Available The vertebrate cranium is a prime example of the high evolvability of complex traits. While evidence of genes and developmental pathways underlying craniofacial shape determination is accumulating, we are still far from understanding how such variation at the genetic level is translated into craniofacial shape variation. Here we used 3D geometric morphometrics to map genes involved in shape determination in a population of outbred mice (Carworth Farms White, or CFW. We defined shape traits via principal component analysis of 3D skull and mandible measurements. We mapped genetic loci associated with shape traits at ~80,000 candidate single nucleotide polymorphisms in ~700 male mice. We found that craniofacial shape and size are highly heritable, polygenic traits. Despite the polygenic nature of the traits, we identified 17 loci that explain variation in skull shape, and 8 loci associated with variation in mandible shape. Together, the associated variants account for 11.4% of skull and 4.4% of mandible shape variation, however, the total additive genetic variance associated with phenotypic variation was estimated in ~45%. Candidate genes within the associated loci have known roles in craniofacial development; this includes 6 transcription factors and several regulators of bone developmental pathways. One gene, Mn1, has an unusually large effect on shape variation in our study. A knockout of this gene was previously shown to affect negatively the development of membranous bones of the cranial skeleton, and evolutionary analysis shows that the gene has arisen at the base of the bony vertebrates (Eutelostomi, where the ossified head first appeared. Therefore, Mn1 emerges as a key gene for both skull formation and within-population shape variation. Our study shows that it is possible to identify important developmental genes through genome-wide mapping of high-dimensional shape features in an outbred population.

  8. Mapping of Craniofacial Traits in Outbred Mice Identifies Major Developmental Genes Involved in Shape Determination.

    Science.gov (United States)

    Pallares, Luisa F; Carbonetto, Peter; Gopalakrishnan, Shyam; Parker, Clarissa C; Ackert-Bicknell, Cheryl L; Palmer, Abraham A; Tautz, Diethard

    2015-11-01

    The vertebrate cranium is a prime example of the high evolvability of complex traits. While evidence of genes and developmental pathways underlying craniofacial shape determination is accumulating, we are still far from understanding how such variation at the genetic level is translated into craniofacial shape variation. Here we used 3D geometric morphometrics to map genes involved in shape determination in a population of outbred mice (Carworth Farms White, or CFW). We defined shape traits via principal component analysis of 3D skull and mandible measurements. We mapped genetic loci associated with shape traits at ~80,000 candidate single nucleotide polymorphisms in ~700 male mice. We found that craniofacial shape and size are highly heritable, polygenic traits. Despite the polygenic nature of the traits, we identified 17 loci that explain variation in skull shape, and 8 loci associated with variation in mandible shape. Together, the associated variants account for 11.4% of skull and 4.4% of mandible shape variation, however, the total additive genetic variance associated with phenotypic variation was estimated in ~45%. Candidate genes within the associated loci have known roles in craniofacial development; this includes 6 transcription factors and several regulators of bone developmental pathways. One gene, Mn1, has an unusually large effect on shape variation in our study. A knockout of this gene was previously shown to affect negatively the development of membranous bones of the cranial skeleton, and evolutionary analysis shows that the gene has arisen at the base of the bony vertebrates (Eutelostomi), where the ossified head first appeared. Therefore, Mn1 emerges as a key gene for both skull formation and within-population shape variation. Our study shows that it is possible to identify important developmental genes through genome-wide mapping of high-dimensional shape features in an outbred population.

  9. Modeling Self-Occlusions/Disocclusions in Dynamic Shape and Appearance Tracking for Obtaining Precise Shape

    KAUST Repository

    Yang, Yanchao

    2013-05-01

    We present a method to determine the precise shape of a dynamic object from video. This problem is fundamental to computer vision, and has a number of applications, for example, 3D video/cinema post-production, activity recognition and augmented reality. Current tracking algorithms that determine precise shape can be roughly divided into two categories: 1) Global statistics partitioning methods, where the shape of the object is determined by discriminating global image statistics, and 2) Joint shape and appearance matching methods, where a template of the object from the previous frame is matched to the next image. The former is limited in cases of complex object appearance and cluttered background, where global statistics cannot distinguish between the object and background. The latter is able to cope with complex appearance and a cluttered background, but is limited in cases of camera viewpoint change and object articulation, which induce self-occlusions and self-disocclusions of the object of interest. The purpose of this thesis is to model self-occlusion/disocclusion phenomena in a joint shape and appearance tracking framework. We derive a non-linear dynamic model of the object shape and appearance taking into account occlusion phenomena, which is then used to infer self-occlusions/disocclusions, shape and appearance of the object in a variational optimization framework. To ensure robustness to other unmodeled phenomena that are present in real-video sequences, the Kalman filter is used for appearance updating. Experiments show that our method, which incorporates the modeling of self-occlusion/disocclusion, increases the accuracy of shape estimation in situations of viewpoint change and articulation, and out-performs current state-of-the-art methods for shape tracking.

  10. Differences in Radiotherapy Delivery and Outcome Due to Contouring Variation

    DEFF Research Database (Denmark)

    Hollensen, Christian; Persson, Gitte; Højgaard, Liselotte

    2012-01-01

    Gross tumor volume (GTV) delineation is central for radiotherapy planning. It provides the basis of the clinical target volume and, ultimately, the planning target volume which is used for dose optimization. Manual GTV delineations are prone to intra- and inter-observer variation and automatic...

  11. Breathing Life into Shapes.

    Science.gov (United States)

    Jacobson, Alec

    2015-01-01

    Shape articulation transforms a lifeless geometric object into a vibrant character. Computers enrich artists' toolsets dramatically. They not only endow artists with the power to manipulate virtual 2D and 3D scenes, but they also eliminate tedium and expedite prototyping, freeing artists to focus on creative aspects. With such power comes a temptation to lean entirely on the computer. Computationally intensive animation systems sacrifice real-time feedback for physical accuracy. How can we leverage modern computational power to create the best possible shape deformations while maintaining real-time performance as a mandatory invariant? This article summarizes efforts to answer this, culminating in a deformation system with the quality of slow, nonlinear optimization, but at lightning speed.

  12. Shaping the Social

    DEFF Research Database (Denmark)

    Andersen, Susan; Tolstrup, Janne Schurmann; Rod, Morten Hulvej

    2015-01-01

    BACKGROUND: The social environment at schools is an important setting to promote educational attainment, and health and well-being of young people. However, within upper secondary education there is a need for evidence-based school intervention programmes. The Shaping the Social intervention...... is a comprehensive programme integrating social and educational activities to promote student well-being and reduce smoking and dropout in upper secondary vocational education. The evaluation design is reported here. METHODS/DESIGN: The evaluation employed a non-randomised cluster controlled design, and schools were...... national education registers through a 2-year follow-up period. DISCUSSION: Shaping the Social was designed to address that students at Danish vocational schools constitute a high risk population concerning health behaviour as well as school dropout by modifying the school environment, alongside developing...

  13. Shape Changing Airfoil

    Science.gov (United States)

    Ott, Eric A.

    2005-01-01

    Scoping of shape changing airfoil concepts including both aerodynamic analysis and materials-related technology assessment effort was performed. Three general categories of potential components were considered-fan blades, booster and compressor blades, and stator airfoils. Based on perceived contributions to improving engine efficiency, the fan blade was chosen as the primary application for a more detailed assessment. A high-level aerodynamic assessment using a GE90-90B Block 4 engine cycle and fan blade geometry indicates that blade camber changes of approximately +/-4deg would be sufficient to result in fan efficiency improvements nearing 1 percent. Constraints related to flight safety and failed mode operation suggest that use of the baseline blade shape with actuation to the optimum cruise condition during a portion of the cycle would be likely required. Application of these conditions to the QAT fan blade and engine cycle was estimated to result in an overall fan efficiency gain of 0.4 percent.

  14. Shaping the Social

    DEFF Research Database (Denmark)

    Andersen, Susan; Tolstrup, Janne Schurmann; Rod, Morten Hulvej

    2015-01-01

    is a comprehensive programme integrating social and educational activities to promote student well-being and reduce smoking and dropout in upper secondary vocational education. The evaluation design is reported here. METHODS/DESIGN: The evaluation employed a non-randomised cluster controlled design, and schools were......BACKGROUND: The social environment at schools is an important setting to promote educational attainment, and health and well-being of young people. However, within upper secondary education there is a need for evidence-based school intervention programmes. The Shaping the Social intervention...... national education registers through a 2-year follow-up period. DISCUSSION: Shaping the Social was designed to address that students at Danish vocational schools constitute a high risk population concerning health behaviour as well as school dropout by modifying the school environment, alongside developing...

  15. Social Shaping of Innovation

    DEFF Research Database (Denmark)

    Buur, Jacob; Mack, Alexandra

    - in particular in a large corporation? This workshop explores how innovation is socially shaped in organizations. Based on our experiences with practices around innovation and collaboration, we start from three proposition about the social shaping of innovation: • Ideas don't thrive as text (i.e. we need......Why is it that some business proposals – no matter how well researched with users and business developed – don’t seem to make it through the organizational jungle to become a real product, while others do? How shall we understand the innovative practices that we engage with our ethnographic work...... to consider other media) • Ideas need socialization (ideas are linked to people, we need to be careful about how we support the social innovation context) • Ideas are local (ideas spring out of a local contingency, we need to take care in how we like them to travel)....

  16. Biomedical Shape Memory Polymers

    Directory of Open Access Journals (Sweden)

    SHEN Xue-lin

    2017-07-01

    Full Text Available Shape memory polymers(SMPs are a class of functional "smart" materials that have shown bright prospects in the area of biomedical applications. The novel smart materials with multifunction of biodegradability and biocompatibility can be designed based on their general principle, composition and structure. In this review, the latest process of three typical biodegradable SMPs(poly(lactide acide, poly(ε-caprolactone, polyurethane was summarized. These three SMPs were classified in different structures and discussed, and shape-memory mechanism, recovery rate and fixed rate, response speed was analysed in detail, also, some biomedical applications were presented. Finally, the future development and applications of SMPs are prospected: two-way SMPs and body temperature induced SMPs will be the focus attension by researchers.

  17. Marginal Shape Deep Learning: Applications to Pediatric Lung Field Segmentation.

    Science.gov (United States)

    Mansoor, Awais; Cerrolaza, Juan J; Perez, Geovanny; Biggs, Elijah; Nino, Gustavo; Linguraru, Marius George

    2017-02-11

    Representation learning through deep learning (DL) architecture has shown tremendous potential for identification, localization, and texture classification in various medical imaging modalities. However, DL applications to segmentation of objects especially to deformable objects are rather limited and mostly restricted to pixel classification. In this work, we propose marginal shape deep learning (MaShDL), a framework that extends the application of DL to deformable shape segmentation by using deep classifiers to estimate the shape parameters. MaShDL combines the strength of statistical shape models with the automated feature learning architecture of DL. Unlike the iterative shape parameters estimation approach of classical shape models that often leads to a local minima, the proposed framework is robust to local minima optimization and illumination changes. Furthermore, since the direct application of DL framework to a multi-parameter estimation problem results in a very high complexity, our framework provides an excellent run-time performance solution by independently learning shape parameter classifiers in marginal eigenspaces in the decreasing order of variation. We evaluated MaShDL for segmenting the lung field from 314 normal and abnormal pediatric chest radiographs and obtained a mean Dice similarity coefficient of 0.927 using only the four highest modes of variation (compared to 0.888 with classical ASM 1 (p-value=0.01) using same configuration). To the best of our knowledge this is the first demonstration of using DL framework for parametrized shape learning for the delineation of deformable objects.

  18. Marginal shape deep learning: applications to pediatric lung field segmentation

    Science.gov (United States)

    Mansoor, Awais; Cerrolaza, Juan J.; Perez, Geovany; Biggs, Elijah; Nino, Gustavo; Linguraru, Marius George

    2017-02-01

    Representation learning through deep learning (DL) architecture has shown tremendous potential for identification, local- ization, and texture classification in various medical imaging modalities. However, DL applications to segmentation of objects especially to deformable objects are rather limited and mostly restricted to pixel classification. In this work, we propose marginal shape deep learning (MaShDL), a framework that extends the application of DL to deformable shape segmentation by using deep classifiers to estimate the shape parameters. MaShDL combines the strength of statistical shape models with the automated feature learning architecture of DL. Unlike the iterative shape parameters estimation approach of classical shape models that often leads to a local minima, the proposed framework is robust to local minima optimization and illumination changes. Furthermore, since the direct application of DL framework to a multi-parameter estimation problem results in a very high complexity, our framework provides an excellent run-time performance solution by independently learning shape parameter classifiers in marginal eigenspaces in the decreasing order of variation. We evaluated MaShDL for segmenting the lung field from 314 normal and abnormal pediatric chest radiographs and obtained a mean Dice similarity coefficient of 0:927 using only the four highest modes of variation (compared to 0:888 with classical ASM1 (p-value=0:01) using same configuration). To the best of our knowledge this is the first demonstration of using DL framework for parametrized shape learning for the delineation of deformable objects.

  19. Bare-Hand Volume Cracker for Raw Volume Data Analysis

    Directory of Open Access Journals (Sweden)

    Bireswar Laha

    2016-09-01

    Full Text Available Analysis of raw volume data generated from different scanning technologies faces a variety of challenges, related to search, pattern recognition, spatial understanding, quantitative estimation, and shape description. In a previous study, we found that the Volume Cracker (VC 3D interaction (3DI technique mitigated some of these problems, but this result was from a tethered glove-based system with users analyzing simulated data. Here, we redesigned the VC by using untethered bare-hand interaction with real volume datasets, with a broader aim of adoption of this technique in research labs. We developed symmetric and asymmetric interfaces for the Bare-Hand Volume Cracker (BHVC through design iterations with a biomechanics scientist. We evaluated our asymmetric BHVC technique against standard 2D and widely used 3D interaction techniques with experts analyzing scanned beetle datasets. We found that our BHVC design significantly outperformed the other two techniques. This study contributes a practical 3DI design for scientists, documents lessons learned while redesigning for bare-hand trackers, and provides evidence suggesting that 3D interaction could improve volume data analysis for a variety of visual analysis tasks. Our contribution is in the realm of 3D user interfaces tightly integrated with visualization, for improving the effectiveness of visual analysis of volume datasets. Based on our experience, we also provide some insights into hardware-agnostic principles for design of effective interaction techniques.

  20. Audiometric shape and presbycusis.

    Science.gov (United States)

    Demeester, Kelly; van Wieringen, Astrid; Hendrickx, Jan-jaap; Topsakal, Vedat; Fransen, Erik; van Laer, Lut; Van Camp, Guy; Van de Heyning, Paul

    2009-04-01

    The aim of this study was to describe the prevalence of specific audiogram configurations in a healthy, otologically screened population between 55 and 65 years old. The audiograms of 1147 subjects (549 males and 598 females between 55 and 65 years old) were collected through population registries and classified according to the configuration of hearing loss. Gender and noise/solvent-exposure effects on the prevalence of the different audiogram shapes were determined statistically. In our population 'Flat' audiograms were most dominantly represented (37%) followed by 'High frequency Gently sloping' audiograms (35%) and 'High frequency Steeply sloping' audiograms (27%). 'Low frequency Ascending' audiograms, 'Mid frequency U-shape' audiograms and 'Mid frequency Reverse U-shape' audiograms were very rare (together less than 1%). The 'Flat'-configuration was significantly more common in females, whereas the 'High frequency Steeply sloping'-configuration was more common in males. Exposure to noise and/or solvents did not change this finding. In addition, females with a 'Flat' audiogram had a significantly larger amount of overall hearing loss compared to males. Furthermore, our data reveal a significant association between the prevalence of 'High frequency Steeply sloping' audiograms and the degree of noise/solvent exposure, despite a relatively high proportion of non-exposed subjects showing a 'High frequency Steeply sloping' audiogram as well.

  1. Toward a comparative analysis of three-dimensional shape measures

    Science.gov (United States)

    Power, Gregory J.; Gregga, Jason B.

    2002-02-01

    Measuring a system's capability to acquire accurate three- dimensional shape is important for validating the system for a particular application. Various system factors are reviewed that contribute to inaccurate shape. As shown in this paper, different shape measures do not do a complete evaluation but provide different information depending on the type of error. A partial-directed hausdorf (PDH) and complex inner product (CIP) measure that were previously introduced to measure two-dimensional shapes are now extended to measure three-dimensional shapes. PDH measures how close the 3D surface is to the ideal 3D surface within a predefined acceptable error margin, while the CIP measures how well the 3D surface correlates to the ideal 3D surface. Two variants of the CIP measure are used in this paper including a pure phase only filter and a normalized matched filter. The CIP measure is compared to the Procrustes metric for comparing shapes. Using a test case shape, the measures are compared and shown to provide varying information. Alone, any one measure cannot provide complete shape information. Combining measures provides a more robust three-dimensional shape measurement system. The shape measures are demonstrated first on three-dimensional data with controlled variation and then on laser ranging data.

  2. Hospital variation in mortality after first acute myocardial infarction in Denmark from 1995 to 2002: lower short-term and 1-year mortality in high-volume and specialized hospitals

    DEFF Research Database (Denmark)

    Rasmussen, Søren; Zwisler, Ann-Dorthe O; Abildstrom, Steen Z

    2005-01-01

    with their first admission for AMI between 1995 and 2002 and surviving the day of admission. Multilevel logistic regression was used to determine the relationships between regional and hospital characteristics and 28-day and 365-day mortality after adjusting for individual characteristics, period, and medical......BACKGROUND: This study used linked data from the National Hospital Registry to determine the factors that contribute to differences between hospitals in all-cause mortality after first acute myocardial infarction (AMI) between 1995 and 2002. METHODS: The study included 64,321 patients...... history. RESULTS: Tertiary cardiac care centers (odds ratio [OR], 0.80; 95% confidence interval [CI], 0.67-0.96) and main regional hospitals (OR, 0.90; 95% CI, 0.80-0.99) had improved 28-day mortality compared with local hospitals. A 2-fold increase in annual total MI volume decreased 28-day mortality (OR...

  3. Abstract shape analysis of RNA.

    Science.gov (United States)

    Janssen, Stefan; Giegerich, Robert

    2014-01-01

    Abstract shape analysis abstract shape analysis is a method to learn more about the complete Boltzmann ensemble of the secondary structures of a single RNA molecule. Abstract shapes classify competing secondary structures into classes that are defined by their arrangement of helices. It allows us to compute, in addition to the structure of minimal free energy, a set of structures that represents relevant and interesting structural alternatives. Furthermore, it allows to compute probabilities of all structures within a shape class. This allows to ensure that our representative subset covers the complete Boltzmann ensemble, except for a portion of negligible probability. This chapter explains the main functions of abstract shape analysis, as implemented in the tool RNA shapes. RNA shapes It reports on some other types of analysis that are based on the abstract shapes idea and shows how you can solve novel problems by creating your own shape abstractions.

  4. Individual personalities shape task differentiation in a social spider

    OpenAIRE

    Grinsted, Lena; Pruitt, Jonathan N.; Settepani, Virginia; Bilde, Trine

    2013-01-01

    Deciphering the mechanisms involved in shaping social structure is key to a deeper understanding of the evolutionary processes leading to sociality. Individual specialization within groups can increase colony efficiency and consequently productivity. Here, we test the hypothesis that within-group variation in individual personalities (i.e. boldness and aggression) can shape task differentiation. The social spider Stegodyphus sarasinorum (Eresidae) showed task differentiation (significant uneq...

  5. Annealing-induced shape recovery in thin film metallic glass

    Energy Technology Data Exchange (ETDEWEB)

    Negussie, Alemu Tesfaye; Diyatmika, Wahyu [Department of Materials Science and Engineering, National Taiwan University of Science and Technology, Taipei 10607, Taiwan (China); Chu, J.P., E-mail: jpchu@mail.ntust.edu.tw [Department of Materials Science and Engineering, National Taiwan University of Science and Technology, Taipei 10607, Taiwan (China); Shen, Y.L. [Department of Mechanical Engineering, University of New Mexico, Albuquerque, NM 87131 (United States); Jang, J.S.C. [Department of Mechanical Engineering, National Central University, Chung-Li 32001, Taiwan (China); Hsueh, C.H. [Department of Materials Science and Engineering, National Taiwan University, Taipei 10617, Taiwan (China)

    2014-11-15

    Highlights: • Annealing-induced shape recovery of thin film metallic glass is examined. • Shape recovery becomes obvious with increasing temperature and holding time. • Minimum roughness is obtained when annealed within supercooled liquid region. • The amount of free volume in the film plays a role for the shape recovery. • The numerical simulation confirms the shape recovery upon annealing. - Abstract: The shape recovery property of a sputtered Zr{sub 50.3}Cu{sub 28.1}Al{sub 14}Ni{sub 7.6} (in at.%) thin film metallic glass upon heating is examined. Due to the surface tension-driven viscous flow, the shape of indentation appears to recover to different extents at various temperatures and holding times. It is found that a maximum of 59.8% indentation depth recovery is achieved after annealing within the supercooled liquid region (SCLR). The amount of free volume in the film is found to play a role in the recovery. Atomic force microscopy results reveal a decrease in film roughness to a minimum value within SCLR. To elucidate the experimentally observed shape recovery, a numerical modeling has been employed. It is evident that the depressed region caused by indentation is elevated after annealing.

  6. Rational strategy for shaped nanomaterial synthesis in reverse micelle reactors

    Science.gov (United States)

    Wei, Zengyan; Matsui, Hiroshi

    2014-05-01

    The shape-controlled synthesis of nanoparticles was established in single-phase solutions by controlling growth directions of crystalline facets on seed nanocrystals kinetically; however, it was difficult to rationally predict and design nanoparticle shapes. Here we introduce a methodology to fabricate nanoparticles in smaller sizes by evolving shapes thermodynamically. This strategy enables a more rational approach to fabricate shaped nanoparticles by etching specific positions of atoms on facets of seed nanocrystals in reverse micelle reactors where the surface energy gradient induces desorption of atoms on specific locations on the seed surfaces. From seeds of 12-nm palladium nanocubes, the shape is evolved to concave nanocubes and finally hollow nanocages in the size ~10 nm by etching the centre of {200} facets. The high surface area-to-volume ratio and the exposure of a large number of palladium atoms on ledge and kink sites of hollow nanocages are advantageous to enhance catalytic activity and recyclability.

  7. Multidetector Row CT Findings of a Sternal Variation

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Young Tong [Soonchunhyang University Cheonan Hospital, Cheonan (Korea, Republic of)

    2009-09-15

    Upon development of the sternum, wide variations in the sternum result from the variability of the number and configuration of the ossification centers, and different degrees of ossification. Multiplanar-reformed and volume-rendered images using multidetector row CT (MDCT) are useful to evaluate the wide variation of sternum. The purpose of this article is to show the MDCT findings of sternal variation

  8. Variation of surface electric field during geomagnetic disturbed ...

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Earth System Science; Volume 124; Issue 8. Variation of surface electric field ... Diurnal variation of surface electric field measured at Maitri shows a similar variation with worldwide thunderstorm activity, whereas the departure of the field is observed during disturbed periods. This part of the field ...

  9. Remote Sensing of Crystal Shapes in Ice Clouds

    Science.gov (United States)

    van Diedenhoven, Bastiaan

    2017-01-01

    Ice crystals in clouds exist in a virtually limitless variation of geometries. The most basic shapes of ice crystals are columnar or plate-like hexagonal prisms with aspect ratios determined by relative humidity and temperature. However, crystals in ice clouds generally display more complex structures owing to aggregation, riming and growth histories through varying temperature and humidity regimes. Crystal shape is relevant for cloud evolution as it affects microphysical properties such as fall speeds and aggregation efficiency. Furthermore, the scattering properties of ice crystals are affected by their general shape, as well as by microscopic features such as surface roughness, impurities and internal structure. To improve the representation of ice clouds in climate models, increased understanding of the global variation of crystal shape and how it relates to, e.g., location, cloud temperature and atmospheric state is crucial. Here, the remote sensing of ice crystal macroscale and microscale structure from airborne and space-based lidar depolarization observations and multi-directional measurements of total and polarized reflectances is reviewed. In addition, a brief overview is given of in situ and laboratory observations of ice crystal shape as well as the optical properties of ice crystals that serve as foundations for the remote sensing approaches. Lidar depolarization is generally found to increase with increasing cloud height and to vary with latitude. Although this variation is generally linked to the variation of ice crystal shape, the interpretation of the depolarization remains largely qualitative and more research is needed before quantitative conclusions about ice shape can be deduced. The angular variation of total and polarized reflectances of ice clouds has been analyzed by numerous studies in order to infer information about ice crystal shapes from them. From these studies it is apparent that pristine crystals with smooth surfaces are generally

  10. Porous Shape Memory Polymers

    Science.gov (United States)

    Hearon, Keith; Singhal, Pooja; Horn, John; Small, Ward; Olsovsky, Cory; Maitland, Kristen C.; Wilson, Thomas S.; Maitland, Duncan J.

    2013-01-01

    Porous shape memory polymers (SMPs) include foams, scaffolds, meshes, and other polymeric substrates that possess porous three-dimensional macrostructures. Porous SMPs exhibit active structural and volumetric transformations and have driven investigations in fields ranging from biomedical engineering to aerospace engineering to the clothing industry. The present review article examines recent developments in porous SMPs, with focus given to structural and chemical classification, methods of characterization, and applications. We conclude that the current body of literature presents porous SMPs as highly interesting smart materials with potential for industrial use. PMID:23646038

  11. Oriented active shape models.

    Science.gov (United States)

    Liu, Jiamin; Udupa, Jayaram K

    2009-04-01

    Active shape models (ASM) are widely employed for recognizing anatomic structures and for delineating them in medical images. In this paper, a novel strategy called oriented active shape models (OASM) is presented in an attempt to overcome the following five limitations of ASM: 1) lower delineation accuracy, 2) the requirement of a large number of landmarks, 3) sensitivity to search range, 4) sensitivity to initialization, and 5) inability to fully exploit the specific information present in the given image to be segmented. OASM effectively combines the rich statistical shape information embodied in ASM with the boundary orientedness property and the globally optimal delineation capability of the live wire methodology of boundary segmentation. The latter characteristics allow live wire to effectively separate an object boundary from other nonobject boundaries with similar properties especially when they come very close in the image domain. The approach leads to a two-level dynamic programming method, wherein the first level corresponds to boundary recognition and the second level corresponds to boundary delineation, and to an effective automatic initialization method. The method outputs a globally optimal boundary that agrees with the shape model if the recognition step is successful in bringing the model close to the boundary in the image. Extensive evaluation experiments have been conducted by utilizing 40 image (magnetic resonance and computed tomography) data sets in each of five different application areas for segmenting breast, liver, bones of the foot, and cervical vertebrae of the spine. Comparisons are made between OASM and ASM based on precision, accuracy, and efficiency of segmentation. Accuracy is assessed using both region-based false positive and false negative measures and boundary-based distance measures. The results indicate the following: 1) The accuracy of segmentation via OASM is considerably better than that of ASM; 2) The number of landmarks

  12. Star-shaped oscillations of Leidenfrost drops

    Science.gov (United States)

    Ma, Xiaolei; Liétor-Santos, Juan-José; Burton, Justin C.

    2017-03-01

    We experimentally investigate the self-sustained, star-shaped oscillations of Leidenfrost drops. The drops levitate on a cushion of evaporated vapor over a heated, curved surface. We observe modes with n =2 -13 lobes around the drop periphery. We find that the wavelength of the oscillations depends only on the capillary length of the liquid and is independent of the drop radius and substrate temperature. However, the number of observed modes depends sensitively on the liquid viscosity. The dominant frequency of pressure variations in the vapor layer is approximately twice the drop oscillation frequency, consistent with a parametric forcing mechanism. Our results show that the star-shaped oscillations are driven by capillary waves of a characteristic wavelength beneath the drop and that the waves are generated by a large shear stress at the liquid-vapor interface.

  13. Mast Wake Reduction by Shaping

    National Research Council Canada - National Science Library

    Beauchamp, Charles H

    2005-01-01

    The present invention relates to various mast shapes, in which the mast shapes minimize the production of visible, electro-optic, infrared and radar cross section wake signatures produced by water surface piercing masts...

  14. Object detection via structural feature selection and shape model.

    Science.gov (United States)

    Zhang, Huigang; Bai, Xiao; Zhou, Jun; Cheng, Jian; Zhao, Huijie

    2013-12-01

    In this paper, we propose an approach for object detection via structural feature selection and part-based shape model. It automatically learns a shape model from cluttered training images without need to explicitly use bounding boxes on objects. Our approach first builds a class-specific codebook of local contour features, and then generates structural feature descriptors by combining context shape information. These descriptors are robust to both within-class variations and scale changes. Through exploring pairwise image matching using fast earth mover's distance, feature weights can be iteratively updated. Those discriminative foreground features are assigned high weights and then selected to build a part-based shape model. Finally, object detection is performed by matching each testing image with this model. Experiments show that the proposed method is very effective. It has achieved comparable performance to the state-of-the-art shape-based detection methods, but requires much less training information.

  15. Issues in Biological Shape Modelling

    DEFF Research Database (Denmark)

    Hilger, Klaus Baggesen

    This talk reflects parts of the current research at informatics and Mathematical Modelling at the Technical University of Denmark within biological shape modelling. We illustrate a series of generalizations, modifications, and applications of the elements of constructing models of shape or appear......This talk reflects parts of the current research at informatics and Mathematical Modelling at the Technical University of Denmark within biological shape modelling. We illustrate a series of generalizations, modifications, and applications of the elements of constructing models of shape...

  16. Dynamic light scattering study of peanut agglutinin: Size, shape and ...

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Biosciences; Volume 31; Issue 5. Dynamic light scattering study of peanut agglutinin: Size, shape and urea denaturation ... Peanut agglutinin (PNA) is a homotetrameric protein with a unique open quaternary structure. PNA shows non-two state profile in chaotrope induced denaturation. It passes ...

  17. Analysis of acoustic resonator with shape deformation using finite ...

    Indian Academy of Sciences (India)

    using the finite element method. The shape deformation is such that the volume of the resonator remains constant. The effect of deformation on the resonant frequencies is studied. Deformation splits the degenerate frequencies. Keywords. Finite element method; acoustic resonator; degenerate frequency. 1. Introduction.

  18. Shape change as entropic phase transition: A study using Jarzynski ...

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Chemical Sciences; Volume 124; Issue 1. Shape change as entropic phase transition: A study using ... Click here to view fulltext PDF. Permanent link: http://www.ias.ac.in/article/fulltext/jcsc/124/01/0021-0028. Keywords. Fick-Jacobs equation; entropic potental; Jarzynski equality; phase transition.

  19. Cost effective and shape controlled approach to synthesize ...

    Indian Academy of Sciences (India)

    Cost effective and shape controlled approach to synthesize hierarchically assembled NiO nanoflakes for the removal of toxic heavy metal ions in aqueous solution. K Yogesh Kumar H B Muralidhara Y Arthoba Nayaka H Hanumanthappa M S Veena S R Kiran Kumar. Volume 38 Issue 1 February 2015 pp 271-282 ...

  20. Bladder filling variation during conformal radiotherapy for rectal cancer