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Sample records for dictate primitive endoderm

  1. Cell adhesive affinity does not dictate primitive endoderm segregation and positioning during murine embryoid body formation.

    Science.gov (United States)

    Moore, Robert; Cai, Kathy Q; Escudero, Diogo O; Xu, Xiang-Xi

    2009-09-01

    The classical cell sorting experiments undertaken by Townes and Holtfreter described the intrinsic propensity of dissociated embryonic cells to self-organize and reconcile into their original embryonic germ layers with characteristic histotypic positioning. Steinberg presented the differential adhesion hypothesis to explain these patterning phenomena. Here, we have reappraised these issues by implementing embryoid bodies to model the patterning of epiblast and primitive endoderm layers. We have used combinations of embryonic stem (ES) cells and their derivatives differentiated by retinoic acid treatment to model epiblast and endoderm cells, and wild-type or E-cadherin null cells to represent strongly or weakly adherent cells, respectively. One cell type was fluorescently labeled and reconstituted with another heterotypically to generate chimeric embryoid bodies, and cell sorting was tracked by time-lapse video microscopy and confirmed by immunostaining. When undifferentiated wild-type and E-cadherin null ES cells were mixed, the resulting cell aggregates consisted of a core of wild-type cells surrounded by loosely associated E-cadherin null cells, consistent with the differential adhesion hypothesis. However, when mixed with undifferentiated ES cells, the differentiated primitive endoderm-like cells sorted to the surface to form a primitive endoderm layer irrespective of cell-adhesive strength, contradicting the differential adhesion hypothesis. We propose that the primitive endoderm cells reach the surface by random movement, and subsequently the cells generate an apical/basal polarity that prevents reentry. Thus, the ability to generate epithelial polarity, rather than adhesive affinity, determines the surface positioning of the primitive endoderm cells. (c) 2009 Wiley-Liss, Inc.

  2. Primitive Endoderm Differentiation: From Specification to Epithelialization.

    Science.gov (United States)

    Bassalert, Cécilia; Valverde-Estrella, Lorena; Chazaud, Claire

    2018-01-01

    At the time of implantation, the mouse blastocyst has developed three cell lineages: the epiblast (Epi), the primitive endoderm (PrE), and the trophectoderm (TE). The PrE and TE are extraembryonic tissues but their interactions with the Epi are critical to sustain embryonic growth, as well as to pattern the embryo. We review here the cellular and molecular events that lead to the production of PrE and Epi lineages and discuss the different hypotheses that are proposed for the induction of these cell types. In the second part, we report the current knowledge about the epithelialization of the PrE. © 2018 Elsevier Inc. All rights reserved.

  3. Live imaging of primitive endoderm precursors in the mouse blastocyst.

    Science.gov (United States)

    Grabarek, Joanna B; Plusa, Berenika

    2012-01-01

    The separation of two populations of cells-primitive endoderm and epiblast-within the inner cell mass (ICM) of the mammalian blastocyst is a crucial event during preimplantation development. However, many aspects of this process are still not very well understood. Recently, the identification of platelet derived growth factor receptor alpha (Pdgfrα) as an early-expressed protein that is also a marker of the later primitive endoderm lineage, together with the availability of the Pdgfra(H2B-GFP) mouse strain (Hamilton et al. Mol Cell Biol 23:4013-4025, 2003), has made in vivo imaging of primitive endoderm formation possible. In this chapter we present two different approaches that can be used to follow the behavior of primitive endoderm cells within the mouse blastocyst in real time.

  4. Polycomb enables primitive endoderm lineage priming in embryonic stem cells

    DEFF Research Database (Denmark)

    Illingworth, Robert S; Hölzenspies, Jurriaan J; Roske, Fabian V

    2016-01-01

    Mouse embryonic stem cells (ESCs), like the blastocyst from which they are derived, contain precursors of the epiblast (Epi) and primitive endoderm (PrEn) lineages. While transient in vivo, these precursor populations readily interconvert in vitro. We show that altered transcription is the driver...... polycomb with dynamic changes in transcription and stalled lineage commitment, allowing cells to explore alternative choices prior to a definitive decision....

  5. A close look at the mammalian blastocyst: epiblast and primitive endoderm formation.

    Science.gov (United States)

    Artus, Jérôme; Chazaud, Claire

    2014-09-01

    During early development, the mammalian embryo undergoes a series of profound changes that lead to the formation of two extraembryonic tissues--the trophectoderm and the primitive endoderm. These tissues encapsulate the pluripotent epiblast at the time of implantation. The current model proposes that the formation of these lineages results from two consecutive binary cell fate decisions. The first controls the formation of the trophectoderm and the inner cell mass, and the second controls the formation of the primitive endoderm and the epiblast within the inner cell mass. While early mammalian embryos develop with extensive plasticity, the embryonic pattern prior to implantation is remarkably reproducible. Here, we review the molecular mechanisms driving the cell fate decision between primitive endoderm and epiblast in the mouse embryo and integrate data from recent studies into the current model of the molecular network regulating the segregation between these lineages and their subsequent differentiation.

  6. Canonical Wnt signaling induces a primitive endoderm metastable state in mouse embryonic stem cells.

    Science.gov (United States)

    Price, Feodor D; Yin, Hang; Jones, Andrew; van Ijcken, Wilfred; Grosveld, Frank; Rudnicki, Michael A

    2013-04-01

    Activation of the canonical Wnt signaling pathway synergizes with leukemia inhibitory factor (LIF) to maintain pluripotency of mouse embryonic stem cells (mESCs). However, in the absence of LIF, Wnt signaling is unable to maintain ESCs in the undifferentiated state. To investigate the role of canonical Wnt signaling in pluripotency and lineage specification, we expressed Wnt3a in mESCs and characterized them in growth and differentiation. We found that activated canonical Wnt signaling induced the formation of a reversible metastable primitive endoderm state in mESC. Upon subsequent differentiation, Wnt3a-stimulated mESCs gave rise to large quantities of visceral endoderm. Furthermore, we determined that the ability of canonical Wnt signaling to induce a metastable primitive endoderm state was mediated by Tbx3. Our data demonstrates a specific role for canonical Wnt signaling in promoting pluripotency while at the same time priming cells for subsequent differentiation into the primitive endoderm lineage. Copyright © 2013 AlphaMed Press.

  7. p120 Catenin-Mediated Stabilization of E-Cadherin Is Essential for Primitive Endoderm Specification.

    Directory of Open Access Journals (Sweden)

    Tim Pieters

    2016-08-01

    Full Text Available E-cadherin-mediated cell-cell adhesion is critical for naive pluripotency of cultured mouse embryonic stem cells (mESCs. E-cadherin-depleted mESC fail to downregulate their pluripotency program and are unable to initiate lineage commitment. To further explore the roles of cell adhesion molecules during mESC differentiation, we focused on p120 catenin (p120ctn. Although one key function of p120ctn is to stabilize and regulate cadherin-mediated cell-cell adhesion, it has many additional functions, including regulation of transcription and Rho GTPase activity. Here, we investigated the role of mouse p120ctn in early embryogenesis, mESC pluripotency and early fate determination. In contrast to the E-cadherin-null phenotype, p120ctn-null mESCs remained pluripotent, but their in vitro differentiation was incomplete. In particular, they failed to form cystic embryoid bodies and showed defects in primitive endoderm formation. To pinpoint the underlying mechanism, we undertook a structure-function approach. Rescue of p120ctn-null mESCs with different p120ctn wild-type and mutant expression constructs revealed that the long N-terminal domain of p120ctn and its regulatory domain for RhoA were dispensable, whereas its armadillo domain and interaction with E-cadherin were crucial for primitive endoderm formation. We conclude that p120ctn is not only an adaptor and regulator of E-cadherin, but is also indispensable for proper lineage commitment.

  8. Visceral endoderm and the primitive streak interact to build the fetal-placental interface of the mouse gastrula.

    Science.gov (United States)

    Rodriguez, Adriana M; Downs, Karen M

    2017-12-01

    Hypoblast/visceral endoderm assists in amniote nutrition, axial positioning and formation of the gut. Here, we provide evidence, currently limited to humans and non-human primates, that hypoblast is a purveyor of extraembryonic mesoderm in the mouse gastrula. Fate mapping a unique segment of axial extraembryonic visceral endoderm associated with the allantoic component of the primitive streak, and referred to as the "AX", revealed that visceral endoderm supplies the placentae with extraembryonic mesoderm. Exfoliation of the AX was dependent upon contact with the primitive streak, which modulated Hedgehog signaling. Resolution of the AX's epithelial-to-mesenchymal transition (EMT) by Hedgehog shaped the allantois into its characteristic projectile and individualized placental arterial vessels. A unique border cell separated the delaminating AX from the yolk sac blood islands which, situated beyond the limit of the streak, were not formed by an EMT. Over time, the AX became the hindgut lip, which contributed extensively to the posterior interface, including both embryonic and extraembryonic tissues. The AX, in turn, imparted antero-posterior (A-P) polarity on the primitive streak and promoted its elongation and differentiation into definitive endoderm. Results of heterotopic grafting supported mutually interactive functions of the AX and primitive streak, showing that together, they self-organized into a complete version of the fetal-placental interface, forming an elongated structure that exhibited A-P polarity and was composed of the allantois, an AX-derived rod-like axial extension reminiscent of the embryonic notochord, the placental arterial vasculature and visceral endoderm/hindgut. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

  9. p38 (Mapk14/11) occupies a regulatory node governing entry into primitive endoderm differentiation during preimplantation mouse embryo development

    Czech Academy of Sciences Publication Activity Database

    Thamodaran, V.; Bruce, Alexander

    2016-01-01

    Roč. 6, č. 9 (2016), č. článku 160190. ISSN 2046-2441 Grant - others:GA ČR(CZ) GA13-03295S Institutional support: RVO:60077344 Keywords : preimplantation mouse embryo * cell-fate * primitive endoderm Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 3.481, year: 2016 http://rsob.royalsocietypublishing.org/content/6/9/160190

  10. Design of a nanocomposite substrate inducing adult stem cell assembly and progression toward an Epiblast-like or Primitive Endoderm-like phenotype via mechanotransduction.

    Science.gov (United States)

    Morena, Francesco; Armentano, Ilaria; Montanucci, Pia; Argentati, Chiara; Fortunati, Elena; Montesano, Simona; Bicchi, Ilaria; Pescara, Teresa; Pennoni, Ilaria; Mattioli, Samantha; Torre, Luigi; Latterini, Loredana; Emiliani, Carla; Basta, Giuseppe; Calafiore, Riccardo; Kenny, Josè Maria; Martino, Sabata

    2017-11-01

    This work shows that the active interaction between human umbilical cord matrix stem cells and Poly (l-lactide)acid (PLLA) and PLLA/Multi Walled Carbon Nanotubes (MWCNTs) nanocomposite films results in the stem cell assembly as a spheroid conformation and affects the stem cell fate transition. We demonstrated that spheroids directly respond to a tunable surface and the bulk properties (electric, dielectric and thermal) of plain and nanocomposite PLLA films by triggering a mechanotransduction axis. This stepwise process starts from tethering of the cells' focal adhesion proteins to the surface, together with the adherens junctions between cells. Both complexes transmit traction forces to F-Actin stress fibres that link Filamin-A and Myosin-IIA proteins, generating a biological scaffold, with increased stiffening conformation from PLLA to PLLA/MWCNTs, and enable the nucleoskeleton proteins to boost chromatin reprogramming processes. Herein, the opposite expression of NANOG and GATA6 transcription factors, together with other lineage specification related proteins, steer spheroids toward an Epiblast-like or Primitive Endoderm-like lineage commitment, depending on the absence or presence of 1 wt% MWCNTs, respectively. This work represents a pioneering effort to create a stem cell/material interface that can model the stem cell fate transition under growth culture conditions. Copyright © 2017 Elsevier Ltd. All rights reserved.

  11. LIF supports primitive endoderm expansion during pre-implantation development

    DEFF Research Database (Denmark)

    Morgani, Sophie M; Brickman, Joshua M

    2015-01-01

    Embryonic stem cells (ESCs) are pluripotent cell lines that can be maintained indefinitely in an early developmental state. ESC culture conditions almost always require the cytokine LIF to maintain self-renewal. As ESCs are not homogeneous but contain multiple populations reminiscent...... of the blastocyst, identifying the target cells of LIF is necessary to understand the propagation of pluripotency. We recently found that LIF acts under self-renewing conditions to stimulate the fraction of ESCs that express extraembryonic markers, but has little impact on pluripotent gene expression. Here, we...... derivatives, whereas the increase in PrE is mediated both by an increase in proliferation and inhibition of PrE apoptosis that is normally triggered in embryos with an excess of GATA6(+) cells. Thus, it appears that the relative size of the PrE is determined by the number of LIF-producing cells in the embryo...

  12. Machine Dictation and Transcription.

    Science.gov (United States)

    Harvey, Evelyn; And Others

    This instructional package contains both an instructor's manual and a student's manual for a course in machine dictation and transcription. The instructor's manual contains an overview with tips on teaching the course, letters for dictation, and a key to the letters. The student's manual contains an overview of the course and of the skills needed…

  13. A Survey of Great Dictators.

    Science.gov (United States)

    Zoerner, C. E., Jr.

    1981-01-01

    A survey of 14 business managers possessing outstanding dictating skills reveals that preparation is the key to efficient dictation, dictation is not confined to brief letters or memos, the ability to dictate over the phone and to machines is important, and you cannot dictate if you cannot write. (FL)

  14. On Synchronization Primitive Systems.

    Science.gov (United States)

    The report studies the question: what synchronization primitive should be used to handle inter-process communication. A formal model is presented...between these synchronization primitives. Although only four synchronization primitives are compared, the general methods can be used to compare other... synchronization primitives. Moreover, in the definitions of these synchronization primitives, conditional branches are explicitly allowed. In addition

  15. Supratentorial endodermal cysts: review of literature and case report.

    Science.gov (United States)

    Caruso, Riccardo; Artico, Marco; Colonnese, Claudio; Marrocco, Luigi; Wierzbicki, Venceslao

    2013-11-01

    Supratentorial endodermal cysts are very rare pathological entities. Their pathoembryology is largely unknown and they can represent a diagnostic challenge. A research performed on the PubMed database in December 2010, to screen for supratentorial endodermal cyst studies, demonstrated that since 1960 only 31 supratentorial endodermal cysts have been described in the literature, including our case: a 42-year-old woman with a parasellar endodermal cyst. These lesions are usually benign. As with other types of brain cysts, the signs and symptoms caused by supratentorial endodermal cysts are mainly linked to the compression or irritation of surrounding neural structures. Upon neuroimaging examination, they typically appear as a round or lobulated mass. The signal intensity may vary depending on the protein content of the cyst. The majority of reported supratentorial endodermal cysts were completely excised with good or excellent results. Incomplete excision can result in an increased risk of recurrence, infection, and dissemination. Georg Thieme Verlag KG Stuttgart · New York.

  16. Abelian primitive words

    OpenAIRE

    Domaratzki, Michael; Rampersad, Narad

    2011-01-01

    We investigate Abelian primitive words, which are words that are not Abelian powers. We show that unlike classical primitive words, the set of Abelian primitive words is not context-free. We can determine whether a word is Abelian primitive in linear time. Also different from classical primitive words, we find that a word may have more than one Abelian root. We also consider enumeration problems and the relation to the theory of codes. Peer reviewed

  17. Intracardiac heterotopia--mesenchymal and endodermal.

    Science.gov (United States)

    Ariza, S; Rafel, E; Castillo, J A; Garcia-Canton, J A

    1978-01-01

    A case is reported of an intracardiac 'epithelial heterotopia' with a predominant mesenchymal component. This is thought to have resulted from the differentiation of aberrant primitive cell(s) displaced into the heart during its development. Though microscopically resembling a myxoma, this lesion is clearly distinguished by the presence of glandular structures. The myxoid component exhibited a startling invasiveness which resulted in occlusion of the superior vena cava, causing symptoms very early in life and death at the age of 6 months. Images PMID:637987

  18. Efficient differentiation of human embryonic stem cells to definitive endoderm.

    Science.gov (United States)

    D'Amour, Kevin A; Agulnick, Alan D; Eliazer, Susan; Kelly, Olivia G; Kroon, Evert; Baetge, Emmanuel E

    2005-12-01

    The potential of human embryonic stem (hES) cells to differentiate into cell types of a variety of organs has generated much excitement over the possible use of hES cells in therapeutic applications. Of great interest are organs derived from definitive endoderm, such as the pancreas. We have focused on directing hES cells to the definitive endoderm lineage as this step is a prerequisite for efficient differentiation to mature endoderm derivatives. Differentiation of hES cells in the presence of activin A and low serum produced cultures consisting of up to 80% definitive endoderm cells. This population was further enriched to near homogeneity using the cell-surface receptor CXCR4. The process of definitive endoderm formation in differentiating hES cell cultures includes an apparent epithelial-to-mesenchymal transition and a dynamic gene expression profile that are reminiscent of vertebrate gastrulation. These findings may facilitate the use of hES cells for therapeutic purposes and as in vitro models of development.

  19. The Flemish Primitives

    NARCIS (Netherlands)

    Vos, De Dirk

    2003-01-01

    Intensely realistic, piercingly beautiful, the art of the Flemish Primitives inspires powerful emotional responses. Painted during the fifteenth century in the southern Netherlands, these influential and enduring works helped establish the foundations of modern European painting.Sumptuously

  20. Two different pathways for the transport of primitive and definitive blood cells from the yolk sac to the embryo in humans.

    Science.gov (United States)

    Pereda, Jaime; Monge, Juan I; Niimi, Gen

    2010-08-01

    During the early human embryonic period nutrients and blood cells are temporarily provided by the extraembryonic yolk sac (YS). The YS before week six is involved not only in primitive but also in definitive erythropoiesis. While the destiny of primitive erythroid cells that fill the blood vessels of the YS is well known, the final destination of erythrocytes present in the endodermal vesicular system is unknown. In the present study we have investigated, step by step, the destiny of the erythrocytes present in the endodermal vesicles during the embryonic period. Twelve human YSs and their corresponding yolk stalks were analyzed between weeks 4 and 7 of embryonic age by light and scanning electron microscopy. It is shown that erythrocytes (according to their size and morphological features) located within the endodermal vesicles of the YS wall are pulled out through endodermal pits into the YS cavity, from where they reach the lumen of the primitive gut of the embryo through the vitelline duct, a temporary pathway communicating both compartments. During the study period no erythrocytes were seen within the embryo's vascular network where only primitive erythroblasts were identified. Our results indicate that the vitelline duct plays an important transient role as a pathway for the transport of nutrients and blood cells between the YS and the embryo before week five of embryonic development that ends just at the time when YS-embryo circulation becomes established. (c) 2010 Wiley-Liss, Inc.

  1. Patterning and shaping the endoderm in vivo and in culture

    DEFF Research Database (Denmark)

    Kraus, Marine R C; Grapin-Botton, Anne

    2012-01-01

    The definitive endoderm (DE) was first defined as the innermost germ layer found in all metazoan embryos. During development, it gives rise to a vast array of specialized epithelial cell types lining the respiratory and digestive systems, and contributes to associated organs such as thyroid, thymus...

  2. Immunohistochemical demonstration of a hitherto undescribed localization of hemoglobin A and F in endodermal cells of normal human yolk sac and endodermal sinus tumor

    DEFF Research Database (Denmark)

    Albrechtsen, R; Wewer, U; Wimberley, P D

    1980-01-01

    In this study of 4 human yolk sacs, the presence of hemoglobin A and F (HbA and HbF) is demonstrated for the first time in epithelial cells (type 1) and erythroid-like cells (type 2) in the endodermal layer by immunoperoxidase technique. Our findings strongly support the hypothesis previously...... proposed that the red blood cells formed in the yolk sac are of endodermal origin. Tumor with yolk sac differentiation (8 endodermal sinus tumors and 1 embryonal carcinoma with vitelline areas) similarly showed HbA and HbF localisation in endodermal cells. None of 59 germ cell tumors of other types...

  3. Moral distance in dictator games

    Directory of Open Access Journals (Sweden)

    Fernando Aguiar

    2008-04-01

    Full Text Available We perform an experimental investigation using a dictator game in which individuals must make a moral decision --- to give or not to give an amount of money to poor people in the Third World. A questionnaire in which the subjects are asked about the reasons for their decision shows that, at least in this case, moral motivations carry a heavy weight in the decision: the majority of dictators give the money for reasons of a consequentialist nature. Based on the results presented here and of other analogous experiments, we conclude that dicator behavior can be understood in terms of moral distance rather than social distance and that it systematically deviates from the egoism assumption in economic models and game theory. %extit{JEL}: A13, C72, C91

  4. Dictator games: A meta study

    OpenAIRE

    Engel, Christoph

    2010-01-01

    Over the last 25 years, more than a hundred dictator game experiments have been published. This meta study summarizes the evidence. Exploiting the fact that most experiments had to fix parameters they did not intend to test, in multiple regression the meta study is able to assess the effect of single manipulations, controlling for a host of alternative explanatory factors. The resulting rich dataset also provides a testbed for comparing alternative specifications of the statistical model for ...

  5. A requirement for FGF signalling in the formation of primitive streak-like intermediates from primitive ectoderm in culture.

    Directory of Open Access Journals (Sweden)

    Zhiqiang Zheng

    Full Text Available BACKGROUND: Embryonic stem (ES cells hold considerable promise as a source of cells with therapeutic potential, including cells that can be used for drug screening and in cell replacement therapies. Differentiation of ES cells into the somatic lineages is a regulated process; before the promise of these cells can be realised robust and rational methods for directing differentiation into normal, functional and safe cells need to be developed. Previous in vivo studies have implicated fibroblast growth factor (FGF signalling in lineage specification from pluripotent cells. Although FGF signalling has been suggested as essential for specification of mesoderm and endoderm in vivo and in culture, the exact role of this pathway remains unclear. METHODOLOGY/PRINCIPAL FINDINGS: Using a culture model based on early primitive ectoderm-like (EPL cells we have investigated the role of FGF signalling in the specification of mesoderm. We were unable to demonstrate any mesoderm inductive capability associated with FGF1, 4 or 8 signalling, even when the factors were present at high concentrations, nor any enhancement in mesoderm formation induced by exogenous BMP4. Furthermore, there was no evidence of alteration of mesoderm sub-type formed with addition of FGF1, 4 or 8. Inhibition of endogenous FGF signalling, however, prevented mesoderm and favoured neural differentiation, suggesting FGF signalling was required but not sufficient for the differentiation of primitive ectoderm into primitive streak-like intermediates. The maintenance of ES cell/early epiblast pluripotent marker expression was also observed in cultures when FGF signalling was inhibited. CONCLUSIONS/SIGNIFICANCE: FGF signalling has been shown to be required for the differentiation of primitive ectoderm to neurectoderm. This, coupled with our observations, suggest FGF signalling is required for differentiation of the primitive ectoderm into the germ lineages at gastrulation.

  6. Pancreatic Endoderm-Derived From Diabetic Patient-Specific Induced Pluripotent Stem Cell Generates Glucose-Responsive Insulin-Secreting Cells.

    Science.gov (United States)

    Rajaei, Bahareh; Shamsara, Mehdi; Amirabad, Leila Mohammadi; Massumi, Mohammad; Sanati, Mohammad Hossein

    2017-10-01

    Human-induced pluripotent stem cells (hiPSCs) can potentially serve as an invaluable source for cell replacement therapy and allow the creation of patient- and disease-specific stem cells without the controversial use of embryos and avoids any immunological incompatibility. The generation of insulin-producing pancreatic β-cells from pluripotent stem cells in vitro provides an unprecedented cell source for personal drug discovery and cell transplantation therapy in diabetes. A new five-step protocol was introduced in this study, effectively induced hiPSCs to differentiate into glucose-responsive insulin-producing cells. This process mimics in vivo pancreatic organogenesis by directing cells through stages resembling definitive endoderm, primitive gut-tube endoderm, posterior foregut, pancreatic endoderm, and endocrine precursor. Each stage of differentiation were characterized by stage-specific markers. The produced cells exhibited many properties of functional β-cells, including expression of critical β-cells transcription factors, the potency to secrete C-peptide in response to high levels of glucose and the presence of mature endocrine secretory granules. This high efficient differentiation protocol, established in this study, yielded 79.18% insulin-secreting cells which were responsive to glucose five times higher than the basal level. These hiPSCs-derived glucose-responsive insulin-secreting cells might provide a promising approach for the treatment of type I diabetes mellitus. J. Cell. Physiol. 232: 2616-2625, 2017. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  7. Retroperitoneal endodermal sinus tumor patient with palliative care needs

    Directory of Open Access Journals (Sweden)

    Surbhi Kashyap

    2016-01-01

    Full Text Available This article is a case reflection of a personal encounter on the palliative care treatment required after the removal of a complicated case of a primary extra-gonadal retro-peritoneal endodermal sinus tumor (yolk sac tumor. This reflection is from the perspective of a recently graduated MD student who spent one month with an Indian pain management and palliative care team at the Institute Rotary Cancer Hospital (IRCH, All India Institute of Medical Sciences (AIIMS, New Delhi

  8. Ins-Robust Primitive Words

    OpenAIRE

    Srivastava, Amit Kumar; Kapoor, Kalpesh

    2017-01-01

    Let Q be the set of primitive words over a finite alphabet with at least two symbols. We characterize a class of primitive words, Q_I, referred to as ins-robust primitive words, which remain primitive on insertion of any letter from the alphabet and present some properties that characterizes words in the set Q_I. It is shown that the language Q_I is dense. We prove that the language of primitive words that are not ins-robust is not context-free. We also present a linear time algorithm to reco...

  9. Goal-based dictator game

    Science.gov (United States)

    Zaibidi, Nerda Zura; Ibrahim, Adyda; Abidin, Norhaslinda Zainal

    2014-12-01

    A considerable number of studies have been conducted to study fairness issues using two-player game. Dictator Game is one of the two-player games that receive much attention. In this paper, we develop an evolutionary approach to the Dictator Game by using Goal programming to build a model of human decision-making for cooperation. The model is formulated based on the theories of cognitive neuroscience that is capable in capturing a more realistic fairness concerns between players in the games. We show that fairness will evolve by taking into account players' aspirations and preferences explicitly in terms of profit and fairness concerns. The model is then simulated to investigate any possible effective strategy for people in economics to deal with fairness coalition. Parallels are drawn between the approach and concepts of human decision making from the field of cognitive neuroscience and psychology. The proposed model is also able to help decision makers to plan or enhance the effective strategies for business purposes.

  10. An endodermal cyst mimicking an intra-axial tumor in the medulla oblongata.

    Science.gov (United States)

    Cho, Jin Mo; Ahn, Jung Yong; Kim, Sun Ho; Lee, Kyu Sung; Chang, Jong Hee

    2010-06-01

    Endodermal cysts, also known as enterogenous, neurenteric, foregut, epithelial, bronchogenic, or respiratory cysts, are rare benign lesions lined by columnar epithelium of a presumed endodermal origin. Endodermal cysts are rarely intracranial, but when this occurs, the cysts are frequently located in the posterior fossa with the most common locations being anterior to the brainstem and within the fourth ventricle. However, an endodermal cyst located in the medulla oblongata is extremely rare. Here, we present a case of a 23-year-old man with an endodermal cyst located in the medulla oblongata. Although rare, clinicians should be aware that this lesion is differentiated from other cystic lesions of the posterior fossa by the absence of a mural nodule. Total resection of endodermal cysts in the medulla oblongata is recommended, despite their location and adhesion to surrounding structures, due to its frequent recurrence.

  11. Radiological findings of the extragonadal endodermal sinus tumors in children

    International Nuclear Information System (INIS)

    Song, Kounn Sik; Yeon, Kyung Mo

    1985-01-01

    Endodermal sinus tumors (EST) are generally recognized as a germ cell tumors with extraembryonic differentiation that resemble the endodermal sinus of the rat placenta. Like other germ cell tumors the primary EST may either occur in the gonads or in specific extragonadal sites. CT is the most accurate study in delineating the extent of primary and metastatic lesions particularly in the pelvis. Recently authors experienced six cases of the pathologically proven extragonadal endodermal sinus tumors in children and retrospectively analyzed the radiological findings including the CT. The results were as follows: 1. Of the 6 cases of extragonadal EST, the primary lesion presented in the sacrococcygeal region in 5 patients and liver in one patient. 2. There were 4 females and 2 males. Of the sacrococcygeal lesions 3 were females and 2 were males. 3. The age of presentation ranged from 9 months to 3 years of age (mean age=21 months). 4. Conventional radiographic study of the sacrococcygeal lesion showed presacral, retrorectal soft tissue mass without calcification which extended into the buttock. CT reveled well circumscribed enhancing soft tissue mass with irregular central low density areas. 5. Primary EST of the liver revealed ill-defined inhomogeneous mixed echogenic mass (ultrasound) and ill-defined low density mass (CT). Angiography showed hypervascular mass with areas of necrosis and no evidence of portal vein invasion. A-V shunting was not present. 6. Regional lymph node metastasis was present at the time of diagnosis in 2 cases of sacrococcygeal EST. 7. Local recurrence of tumor was noted in 2 patients with sacrococcygeal lesion after surgery and chemotherapy

  12. Fatal Lyme carditis and endodermal heterotopia of the atrioventricular node.

    Science.gov (United States)

    Cary, N. R.; Fox, B.; Wright, D. J.; Cutler, S. J.; Shapiro, L. M.; Grace, A. A.

    1990-01-01

    A fatal case of Lyme carditis occurring in a Suffolk farmworker is reported. Post-mortem examination of the heart showed pericarditis, focal myocarditis and prominent endocardial and interstitial fibrosis. The additional finding of endodermal heterotopia ('mesothelioma') of the atrioventricular node raises the possibility that this could also be related to Lyme infection and account for the relatively frequent occurrence of atrioventricular block in this condition. Lyme disease should always be considered in a case of atrioventricular block, particularly in a young patient from a rural area. The heart block tends to improve and therefore only temporary pacing may be required. Images Figure 1 Figure 2 Figure 3 PMID:2349186

  13. Optimal primitive reference frames

    International Nuclear Information System (INIS)

    Jennings, David

    2011-01-01

    We consider the smallest possible directional reference frames allowed and determine the best one can ever do in preserving quantum information in various scenarios. We find that for the preservation of a single spin state, two orthogonal spins are optimal primitive reference frames; and in a product state, they do approximately 22% as well as an infinite-sized classical frame. By adding a small amount of entanglement to the reference frame, this can be raised to 2(2/3) 5 =26%. Under the different criterion of entanglement preservation, a very similar optimal reference frame is found; however, this time it is for spins aligned at an optimal angle of 87 deg. In this case 24% of the negativity is preserved. The classical limit is considered numerically, and indicates under the criterion of entanglement preservation, that 90 deg. is selected out nonmonotonically, with a peak optimal angle of 96.5 deg. for L=3 spins.

  14. Lattice topology dictates photon statistics.

    Science.gov (United States)

    Kondakci, H Esat; Abouraddy, Ayman F; Saleh, Bahaa E A

    2017-08-21

    Propagation of coherent light through a disordered network is accompanied by randomization and possible conversion into thermal light. Here, we show that network topology plays a decisive role in determining the statistics of the emerging field if the underlying lattice is endowed with chiral symmetry. In such lattices, eigenmode pairs come in skew-symmetric pairs with oppositely signed eigenvalues. By examining one-dimensional arrays of randomly coupled waveguides arranged on linear and ring topologies, we are led to a remarkable prediction: the field circularity and the photon statistics in ring lattices are dictated by its parity while the same quantities are insensitive to the parity of a linear lattice. For a ring lattice, adding or subtracting a single lattice site can switch the photon statistics from super-thermal to sub-thermal, or vice versa. This behavior is understood by examining the real and imaginary fields on a lattice exhibiting chiral symmetry, which form two strands that interleave along the lattice sites. These strands can be fully braided around an even-sited ring lattice thereby producing super-thermal photon statistics, while an odd-sited lattice is incommensurate with such an arrangement and the statistics become sub-thermal.

  15. Recurrent ovarian endodermal sinus tumor: demonstration by computed tomography, magnetic resonance imaging, and positron emission tomography

    International Nuclear Information System (INIS)

    Romero, J.A.; Kim, E.E.; Tresukosol, D.; Kudelka, A.P.; Edwards, C.L.; Kavanagh, J.J.

    1995-01-01

    We report a case of recurrent endodermal sinus tumor of the ovary that was identified and/or clearly depicted by computed tomography, magnetic resonance imaging, and positron emission tomography. The potential roles of various imaging modalities in the detection of recurrent endodermal sinus tumor are discussed. (orig.)

  16. Three methods for isolating viable anthozoan endoderm cells with their intracellular symbiotic dinoflagellates

    Science.gov (United States)

    Gates, R. D.; Muscatine, L.

    1992-09-01

    Three maceration methods are described for the isolation of single endoderm cells from marine cnidarians. Two are enzymatic treatments suitable for fleshy anthozoans such as sea anemones and zoanthids. The third employs calcium free sea water and is suitable for stony corals. The viability and morphology of the endoderm cells is described using fluorogenic dyes and scanning and transmission electron microscopy.

  17. Wnt and Hedgehog Signaling Regulate the Differentiation of F9 Cells into Extraembryonic Endoderm

    Directory of Open Access Journals (Sweden)

    Gurjoth S. J. Deol

    2017-10-01

    Full Text Available Mouse F9 cells differentiate into primitive extraembryonic endoderm (PrE when treated with retinoic acid (RA, and this is accompanied by an up-regulation of Gata6. The role of the GATA6 network in PrE differentiation is known, and we have shown it directly activates Wnt6. Canonical Wnt/β-catenin signaling is required by F9 cells to differentiate to PrE, and this, like most developmental processes, requires input from one or more additional pathways. We found both RA and Gata6 overexpression, can induce the expression of Indian Hedgehog (Ihh and a subset of its target genes through Gli activation during PrE induction. Chemical activation of the Hh pathway using a Smoothened agonist (SAG also increased Gli reporter activity, and as expected, when Hh signaling was blocked with a Smoothened antagonist, cyclopamine, this RA-induced reporter activity was reduced. Interestingly, SAG alone failed to induce markers of PrE differentiation, and had no effect on Wnt/β-catenin-dependent TCF-LEF reporter activity. The expected increase in Wnt/β-catenin-dependent TCF-LEF reporter activity and PrE markers induced by RA was, however, blocked by cyclopamine. Finally, inhibiting GSK3 activity with BIO increased both TCF-LEF and Gli reporter activities. Together, we demonstrate the involvement of Hh signaling in the RA-induced differentiation of F9 cells into PrE, and while the activation of the Hh pathway itself is not sufficient, it as well as active Wnt/β-catenin are necessary for F9 cell differentiation.

  18. The lining of the gut in the developing rat embryo. Its relation to the hypoblast (primary endoderm) and the notochord

    NARCIS (Netherlands)

    Lamers, W. H.; Spliet, W. G.; Langemeyer, R. A.

    1987-01-01

    A light microscopical study of the morphogenesis of the gut in the rat embryo was undertaken to provide a careful map of temporal changes in the topographical relations of the (definitive) endoderm, the notochord and the hypoblast (primary endoderm). The borderline between the (definitive) endoderm

  19. Unsupervised Learning of Action Primitives

    DEFF Research Database (Denmark)

    Baby, Sanmohan; Krüger, Volker; Kragic, Danica

    2010-01-01

    and scale, the use of the object can provide a strong invariant for the detection of motion primitives. In this paper we propose an unsupervised learning approach for action primitives that makes use of the human movements as well as the object state changes. We group actions according to the changes......Action representation is a key issue in imitation learning for humanoids. With the recent finding of mirror neurons there has been a growing interest in expressing actions as a combination meaningful subparts called primitives. Primitives could be thought of as an alphabet for the human actions....... In this paper we observe that human actions and objects can be seen as being intertwined: we can interpret actions from the way the body parts are moving, but as well from how their effect on the involved object. While human movements can look vastly different even under minor changes in location, orientation...

  20. Motion Primitives for Action Recognition

    DEFF Research Database (Denmark)

    Fihl, Preben; Holte, Michael Boelstoft; Moeslund, Thomas B.

    2007-01-01

    the actions as a sequence of temporal isolated instances, denoted primitives. These primitives are each defined by four features extracted from motion images. The primitives are recognized in each frame based on a trained classifier resulting in a sequence of primitives. From this sequence we recognize......The number of potential applications has made automatic recognition of human actions a very active research area. Different approaches have been followed based on trajectories through some state space. In this paper we also model an action as a trajectory through a state space, but we represent...... different temporal actions using a probabilistic Edit Distance method. The method is tested on different actions with and without noise and the results show recognition rates of 88.7% and 85.5%, respectively....

  1. Action Recognition using Motion Primitives

    DEFF Research Database (Denmark)

    Moeslund, Thomas B.; Fihl, Preben; Holte, Michael Boelstoft

    the actions as a sequence of temporal isolated instances, denoted primitives. These primitives are each defined by four features extracted from motion images. The primitives are recognized in each frame based on a trained classifier resulting in a sequence of primitives. From this sequence we recognize......The number of potential applications has made automatic recognition of human actions a very active research area. Different approaches have been followed based on trajectories through some state space. In this paper we also model an action as a trajectory through a state space, but we represent...... different temporal actions using a probabilistic Edit Distance method. The method is tested on different actions with and without noise and the results show recognizing rates of 88.7% and 85.5%, respectively....

  2. A Functional Assay for Putative Mouse and Human Definitive Endoderm using Chick Whole-Embryo Cultures

    DEFF Research Database (Denmark)

    Johannesson, Martina; Semb, Tor Henrik; Serup, Palle

    2012-01-01

    . Thus, the purpose of this study is to describe a method whereby the in vivo functionality of DE derived from ESCs can be assessed. Methods: By directed differentiation, putative DE was derived from human and mouse ESCs. This putative DE was subsequently transplanted into the endoderm of chick embryos...... to determine any occurrence of integration. Putative DE was analyzed by gene and protein expression prior to transplantation and 48 h post transplantation. Results: Putative DE, derived from mouse and human ESCs, was successfully integrated within the chick endoderm. Endoderm-specific genes were expressed...... result show that putative DE integrates with the chick endoderm and participate in the development of the chicken gut, indicating the generation of functional DE from ESCs. This functional assay can be used to assess the generation of functional DE derived from both human and mouse ESCs and provides...

  3. AGUA TIBIA PRIMITIVE AREA, CALIFORNIA.

    Science.gov (United States)

    Irwin, William P.; Thurber, Horace K.

    1984-01-01

    The Agua Tibia Primitive Area in southwestern California is underlain by igneous and metamorphic rocks that are siilar to those widely exposed throughout much of the Peninsular Ranges. To detect the presence of any concealed mineral deposits, samples of stream sediments were collected along the various creeks that head in the mountain. As an additional aid in evaluating the mineral potential, an aeromagnetic survey was made and interpreted. A search for records of past or existing mining claims within the primitive area was made but none was found. Evidence of deposits of metallic or nonmetallic minerals was not seen during the study.

  4. Chemistry of primitive solar material

    International Nuclear Information System (INIS)

    Barshay, S.S.; Lewis, J.S.

    1976-01-01

    The chemical processes that occurred in the cooler, outer regions of the primitive solar nebula at the time of intimate chemical contact between preplanetary condensate and nebular gas constitute the subject matter of this review. Condensation models are described and tested against the observed properties of the planets, their satellites, and the asteroids. 6 figs., 2 tables, 48 refs

  5. Cryptographic Primitives with Quasigroup Transformations

    OpenAIRE

    Mileva, Aleksandra

    2010-01-01

    Cryptology is the science of secret communication, which consists of two complementary disciplines: cryptography and cryptanalysis. Cryptography is dealing with design and development of new primitives, algorithms and schemas for data enciphering and deciphering. For many centuries cryptographic technics have been applied in protection of secrecy and authentication in diplomatic, political and military correspondences and communications. Cryptanalysis is dealing with different attacks on c...

  6. Cell lineage analysis demonstrates an endodermal origin of the distal urethra and perineum.

    Science.gov (United States)

    Seifert, Ashley W; Harfe, Brian D; Cohn, Martin J

    2008-06-01

    Congenital malformations of anorectal and genitourinary (collectively, anogenital) organs occur at a high frequency in humans, however the lineage of cells that gives rise to anogenital organs remains poorly understood. The penile urethra has been reported to develop from two cell populations, with the proximal urethra developing from endoderm and the distal urethra forming from an apical ectodermal invagination, however this has never been tested by direct analysis of cell lineage. During gut development, endodermal cells express Sonic hedgehog (Shh), which is required for normal patterning of digestive and genitourinary organs. We have taken advantage of the properties of Shh expression to genetically label and follow the fate of posterior gut endoderm during anogenital development. We report that the entire urethra, including the distal (glandar) region, is derived from endoderm. Cloacal endoderm also gives rise to the epithelial linings of the bladder, rectum and anterior region of the anus. Surprisingly, the lineage map also revealed an endodermal origin of the perineum, which is the first demonstration that endoderm differentiates into skin. In addition, we fate mapped genital tubercle ectoderm and show that it makes no detectable contribution to the urethra. In males, formation of the urethral tube involves septation of the urethral plate by continued growth of the urorectal septum. Analysis of cell lineage following disruption of androgen signaling revealed that the urethral plate of flutamide-treated males does not undergo this septation event. Instead, urethral plate cells persist to the ventral margin of the tubercle, mimicking the pattern seen in females. Based on these spatial and temporal fate maps, we present a new model for anogenital development and suggest that disruptions at specific developmental time points can account for the association between anorectal and genitourinary defects.

  7. From Realistic to Primitive Models: A Primitive Model of Methanol

    Czech Academy of Sciences Publication Activity Database

    Vlček, Lukáš; Nezbeda, Ivo

    2003-01-01

    Roč. 101, č. 19 (2003), s. 2987-2996 ISSN 0026-8976 R&D Projects: GA AV ČR IAA4072303; GA AV ČR IAA4072309 Grant - others:NATO(XX) PST.CLG 978178/6343 Institutional research plan: CEZ:AV0Z4072921 Keywords : primitive model * methanol Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 1.591, year: 2003

  8. Epigenetic Induction of Definitive and Pancreatic Endoderm Cell Fate in Human Fibroblasts

    Directory of Open Access Journals (Sweden)

    Rangarajan Sambathkumar

    2016-01-01

    Full Text Available Reprogramming can occur by the introduction of key transcription factors (TFs as well as by epigenetic changes. We demonstrated that histone deacetylase inhibitor (HDACi Trichostatin A (TSA combined with a chromatin remodeling medium (CRM induced expression of a number of definitive endoderm and early and late pancreatic marker genes. When CRM was omitted, endoderm/pancreatic marker genes were not induced. Furthermore, treatment with DNA methyltransferase inhibitor (DNMTi 5-azacytidine (5AZA CRM did not affect gene expression changes, and when 5AZA was combined with TSA, no further increase in gene expression of endoderm, pancreatic endoderm, and endocrine markers was seen over levels induced with TSA alone. Interestingly, TSA-CRM did not affect expression of pluripotency and hepatocyte genes but induced some mesoderm transcripts. Upon removal of TSA-CRM, the endoderm/pancreatic gene expression profile returned to baseline. Our findings underscore the role epigenetic modification in transdifferentiation of one somatic cell into another. However, full reprogramming of fibroblasts to β-cells will require combination of this approach with TF overexpression and/or culture of the partially reprogrammed cells under β-cell specific conditions.

  9. Timing is everything: Reiterative Wnt, BMP and RA signaling regulate developmental competence during endoderm organogenesis.

    Science.gov (United States)

    Rankin, Scott A; McCracken, Kyle W; Luedeke, David M; Han, Lu; Wells, James M; Shannon, John M; Zorn, Aaron M

    2018-02-01

    A small number of signaling pathways are used repeatedly during organogenesis, and they can have drastically different effects on the same population of cells depending on the embryonic stage. How cellular competence changes over developmental time is not well understood. Here we used Xenopus, mouse, and human pluripotent stem cells to investigate how the temporal sequence of Wnt, BMP, and retinoic acid (RA) signals regulates endoderm developmental competence and organ induction, focusing on respiratory fate. While Nkx2-1+ lung fate is not induced until late somitogenesis stages, here we show that lung competence is restricted by the gastrula stage as a result of Wnt and BMP-dependent anterior-posterior (A-P) patterning. These early Wnt and BMP signals make posterior endoderm refractory to subsequent RA/Wnt/BMP-dependent lung induction. We further mapped how RA modulates the response to Wnt and BMP in a temporal specific manner. In the gastrula RA promotes posterior identity, however in early somite stages of development RA regulates respiratory versus pharyngeal potential in anterior endoderm and midgut versus hindgut potential in posterior endoderm. Together our data suggest a dynamic and conserved response of vertebrate endoderm during organogenesis, wherein early Wnt/BMP/RA impacts how cells respond to later Wnt/BMP/RA signals, illustrating how reiterative combinatorial signaling can regulate both developmental competence and subsequent fate specification. Copyright © 2017 Elsevier Inc. All rights reserved.

  10. The homeobox gene Hex regulates hepatocyte differentiation from embryonic stem cell-derived endoderm.

    Science.gov (United States)

    Kubo, Atsushi; Kim, Yon Hui; Irion, Stefan; Kasuda, Shogo; Takeuchi, Mitsuaki; Ohashi, Kazuo; Iwano, Masayuki; Dohi, Yoshiko; Saito, Yoshihiko; Snodgrass, Ralph; Keller, Gordon

    2010-02-01

    We investigated the role of the hematopoietically expressed homeobox (Hex) in the differentiation and development of hepatocytes within embryonic stem cell (ESC)-derived embryoid bodies (EBs). Analyses of hepatic endoderm derived from Hex(-/-) EBs revealed a dramatic reduction in the levels of albumin (Alb) and alpha-fetoprotein (Afp) expression. In contrast, stage-specific forced expression of Hex in EBs from wild-type ESCs led to the up-regulation of Alb and Afp expression and secretion of Alb and transferrin. These inductive effects were restricted to c-kit(+) endoderm-enriched EB-derived populations, suggesting that Hex functions at the level of hepatic specification of endoderm in this model. Microarray analysis revealed that Hex regulated the expression of a broad spectrum of hepatocyte-related genes, including fibrinogens, apolipoproteins, and cytochromes. When added to the endoderm-induced EBs, bone morphogenetic protein 4 acted synergistically with Hex in the induction of expression of Alb, Afp, carbamoyl phosphate synthetase, transcription factor 1, and CCAAT/enhancer binding protein alpha. These findings indicate that Hex plays a pivotal role during induction of liver development from endoderm in this in vitro model and suggest that this strategy may provide important insight into the generation of functional hepatocytes from ESCs.

  11. An integrin-dependent role of pouch endoderm in hyoid cartilage development.

    Directory of Open Access Journals (Sweden)

    Justin Gage Crump

    2004-09-01

    Full Text Available Pharyngeal endoderm is essential for and can reprogram development of the head skeleton. Here we investigate the roles of specific endodermal structures in regulating craniofacial development. We have isolated an integrinalpha5 mutant in zebrafish that has region-specific losses of facial cartilages derived from hyoid neural crest cells. In addition, the cranial muscles that normally attach to the affected cartilage region and their associated nerve are secondarily reduced in integrinalpha5- animals. Earlier in development, integrinalpha5 mutants also have specific defects in the formation of the first pouch, an outpocketing of the pharyngeal endoderm. By fate mapping, we show that the cartilage regions that are lost in integrinalpha5 mutants develop from neural crest cells directly adjacent to the first pouch in wild-type animals. Furthermore, we demonstrate that Integrinalpha5 functions in the endoderm to control pouch formation and cartilage development. Time-lapse recordings suggest that the first pouch promotes region-specific cartilage development by regulating the local compaction and survival of skeletogenic neural crest cells. Thus, our results reveal a hierarchy of tissue interactions, at the top of which is the first endodermal pouch, which locally coordinates the development of multiple tissues in a specific region of the vertebrate face. Lastly, we discuss the implications of a mosaic assembly of the facial skeleton for the evolution of ray-finned fish.

  12. A Proof-Theoretic Account of Primitive Recursion and Primitive Iteration

    DEFF Research Database (Denmark)

    Cherabini, Luca; Danvy, Olivier

    2011-01-01

    We revisit both the usual ``going-up'' induction principle and Manna and Waldinger's ``going-down'' induction principle for primitive recursion,`a la Goedel, and primitive iteration, `a la Church. We use 'Kleene's trick' to show that primitive recursion and primitive iiteration are as expressive...

  13. SPANISH PEAKS PRIMITIVE AREA, MONTANA.

    Science.gov (United States)

    Calkins, James A.; Pattee, Eldon C.

    1984-01-01

    A mineral survey of the Spanish Peaks Primitive Area, Montana, disclosed a small low-grade deposit of demonstrated chromite and asbestos resources. The chances for discovery of additional chrome resources are uncertain and the area has little promise for the occurrence of other mineral or energy resources. A reevaluation, sampling at depth, and testing for possible extensions of the Table Mountain asbestos and chromium deposit should be undertaken in the light of recent interpretations regarding its geologic setting.

  14. Radiosensitivity related to neuroendocrine and endodermal differentation in lung carcinoma lines

    International Nuclear Information System (INIS)

    Duchesne, G.; Casoni, A.; Pera, M.

    1988-01-01

    A panel of human lung carcinoma lines was studied with respect to hormone production and intermediate filament expression to distinguish between endodermal and neuroendocrine differentation. An index of the degree of neuroendocrine differentiation of each line was derived from the presence or absence of hormone production, cytokeratins, neurofilaments and an embryonic endodermal cell marker, which allowed identification of three groups showing high, intermediate or low neuroendocrine expression. This grouping correlated well with the in vitro radiosensitivity of the lines, those expressing pure neuroendocrine features being significantly more radiosensitive than those with an endodermal phenotype, with the intermediate group having intermediate sensitivity. Use of such an index might predict those patients likely to benefit from the use of radiotherapy in their management. 30 refs.; 3 figs.; 3 tabs

  15. A new FACS approach isolates hESC derived endoderm using transcription factors.

    Directory of Open Access Journals (Sweden)

    Yuqiong Pan

    2011-03-01

    Full Text Available We show that high quality microarray gene expression profiles can be obtained following FACS sorting of cells using combinations of transcription factors. We use this transcription factor FACS (tfFACS methodology to perform a genomic analysis of hESC-derived endodermal lineages marked by combinations of SOX17, GATA4, and CXCR4, and find that triple positive cells have a much stronger definitive endoderm signature than other combinations of these markers. Additionally, SOX17(+ GATA4(+ cells can be obtained at a much earlier stage of differentiation, prior to expression of CXCR4(+ cells, providing an important new tool to isolate this earlier definitive endoderm subtype. Overall, tfFACS represents an advancement in FACS technology which broadly crosses multiple disciplines, most notably in regenerative medicine to redefine cellular populations.

  16. Collagen Type I Improves the Differentiation of Human Embryonic Stem Cells towards Definitive Endoderm

    DEFF Research Database (Denmark)

    Rasmussen, Camilla Holzmann; Petersen, Dorthe Roenn; Møller, Jonas Bech

    2015-01-01

    Human embryonic stem cells have the ability to generate all cell types in the body and can potentially provide an unlimited source of cells for cell replacement therapy to treat degenerative diseases such as diabetes. Current differentiation protocols of human embryonic stem cells towards insulin...... and consistent differentiation of stem cells to definitive endoderm. The results shed light on the importance of extracellular matrix proteins for differentiation and also points to a cost effective and easy method to improve differentiation....... embryonic stem cells to the definitive endoderm lineage. The percentage of definitive endoderm cells after differentiation on collagen I and fibronectin was >85% and 65%, respectively. The cells on collagen I substrates displayed different morphology and gene expression during differentiation as assessed...

  17. Ingression-type cell migration drives vegetal endoderm internalisation in the Xenopus gastrula.

    Science.gov (United States)

    Wen, Jason Wh; Winklbauer, Rudolf

    2017-08-10

    During amphibian gastrulation, presumptive endoderm is internalised as part of vegetal rotation, a large-scale movement that encompasses the whole vegetal half of the embryo. It has been considered a gastrulation process unique to amphibians, but we show that at the cell level, endoderm internalisation exhibits characteristics reminiscent of bottle cell formation and ingression, known mechanisms of germ layer internalisation. During ingression proper, cells leave a single-layered epithelium. In vegetal rotation, the process occurs in a multilayered cell mass; we refer to it as ingression-type cell migration. Endoderm cells move by amoeboid shape changes, but in contrast to other instances of amoeboid migration, trailing edge retraction involves ephrinB1-dependent macropinocytosis and trans -endocytosis. Moreover, although cells are separated by wide gaps, they are connected by filiform protrusions, and their migration depends on C-cadherin and the matrix protein fibronectin. Cells move in the same direction but at different velocities, to rearrange by differential migration.

  18. Efficient Synchronization Primitives for GPUs

    OpenAIRE

    Stuart, Jeff A.; Owens, John D.

    2011-01-01

    In this paper, we revisit the design of synchronization primitives---specifically barriers, mutexes, and semaphores---and how they apply to the GPU. Previous implementations are insufficient due to the discrepancies in hardware and programming model of the GPU and CPU. We create new implementations in CUDA and analyze the performance of spinning on the GPU, as well as a method of sleeping on the GPU, by running a set of memory-system benchmarks on two of the most common GPUs in use, the Tesla...

  19. Give and Take in Dictator Games

    DEFF Research Database (Denmark)

    Cappelen, Alexander W.; Nielsen, Ulrik Haagen; Sørensen, Erik Ø.

    2014-01-01

    It has been shown that participants in the dictator game are less willing to give money to the other participant when their choice set also includes the option to take money. We examine whether this effect is due to the choice set providing a signal about entitlements in a setting where...... entitlements initially may be considered unclear. We find that the share of positive transfers depends on the choice set even when there is no uncertainty about entitlements, and that this choice-set effect is robust across a heterogenous group of participants recruited from the general adult population...

  20. Compositional studies of primitive asteroids

    International Nuclear Information System (INIS)

    Vilas, F.

    1988-01-01

    The composition of primitive asteroids and their relationship to satellites in the solar system will be studied by analyzing existing narrowband charge coupled device (CCD) reflectance spectra, acquiring additional spectra of asteroids and small satellites in the 0.5 to 1.0 micrometer spectral range, and exploring possibilities for obtaining compositional information in the blue-UV spectral region. Comparison with laboratory spectra of terrestrial chlorites and serpentines (phyllosilicates) and the clay minerals found in carbonaceous chondrite meteorites will continue. During 1987, narrowband CCD reflectance spectra of 17 additional asteroids were acquired. These spectra and spectra of 34 other asteroids have been used primarily for two studies: weak absorption features similar to those due to Fe2(+) and Fe2(+) - Fe3(+) transitions in iron oxides f ound in terrestrial chlorites and serpentines and carbonaceous chondrites have been identified in some primitive asteroid spectra. There is a first indication that asteroids grouped by heliocentric distance show similar weak absorption features. Nonparametric statistics are being applied to test the hypothesis of discrete remnants of a gradation in composition of outer-belt asteroids

  1. [Cranial trepanation in primitive cultures].

    Science.gov (United States)

    González-Darder, José Manuel

    A review is presented on cranial trepanations performed by primitive cultures. The scientific interest in this topic began after the discovery in 1965 by Ephraim G. Squier of a pre-Columbian trepanated skull, and studied by Paul Broca in Paris. Pseudotrepanation and other types of cranial manipulation are reviewed. The techniques, technology, and instruments for every type of trepanation are well known. There are a surprisingly high percentage of cases showing signs of post-trepanation survival. Indications for trepanation are speculative, perhaps magic. Although trepanation in primitive cultures is widespread around the world, and throughout time, the main fields of interest are the Neolithic Period in Europe, the pre-Columbian Period in Andean South America, and some contemporaneous Pacific and African tribes. This particular trepanation procedure has no relationship with modern Neurosurgery, or with trepanations with therapeutic purposes performed since the Greco-Roman period in Europe, and afterwards around the world. Copyright © 2016 Sociedad Española de Neurocirugía. Publicado por Elsevier España, S.L.U. All rights reserved.

  2. Breast metastases primitive extra mammary

    International Nuclear Information System (INIS)

    Terzieff, V.; Vázquez, A.; Alonso, I.; Sabini, G.

    2004-01-01

    Less than 3% of all breast cancers originate from a primitive extra mammary. In 40% of cases it is the first manifestation of the primitive properly studied but 80% are associated with widely disseminated disease. It typically presents as a nodule on external quadrant s painful in half the cases. The majority (60%) of metastases derived from breast contralateral breast tumors are believed to via the lymphatic system. of the ; extra mammary the most common tumors are melanoma; hematologic and neuroendocrine. Although some imaging characteristics can guide diagnosis is histological. Cytology has good performance in experienced hands; but up to 25% of cases there may be difficulty in establishing diagnosis. Treatment depends on the type of tumor. Mastectomy should not be practiced or axillary clearance routine as is generally the context of disease disseminated. Radiation therapy may be useful for local control. It has been proposed laser ablation but no experience with it. The overall prognosis is bad. For a man of 45 with a breast metastasis occurs only a clear cell carcinoma of the kidney

  3. Parietal endoderm secreted S100A4 promotes early cardiomyogenesis in embryoid bodies

    DEFF Research Database (Denmark)

    Stary, Martina; Schneider, Mikael; Sheikh, Søren P

    2006-01-01

    Cardiomyogenesis is influenced by factors secreted by anterior-lateral and extra-embryonic endoderm. Differentiation of embryonic stem cells in embryoid bodies allows to study the influence of growth factors on cardiomyogenesis. By these means SPARC was identified as a new factor enhancing cardio...

  4. ENDODERMAL SINUS TUMOR OF THE OVARY DURING PREGNANCY - A CASE-REPORT

    NARCIS (Netherlands)

    VANDERZEE, AGJ; DEBRUIJN, HWA; BOUMA, J; AALDERS, JG; OOSTERHUIS, JW; DEVRIES, EGE

    Serum alpha-fetoprotein screening led to the detection of an endodermal sinus tumor of the ovary in a 24-year-old female in week 17 of pregnancy. After surgery, chemotherapy was postponed. In week 28 levels of serum alpha-fetoprotein increased, but delivery was delayed until 33 weeks' gestation.

  5. Development of MAPC derived induced endodermal progenitors : Generation of pancreatic beta cells and hepatocytes

    NARCIS (Netherlands)

    Sambathkumar, Rangarajan

    2017-01-01

    Multipotent Adult Progenitor Cells (MAPCs) are one potential stem cell source to generate functional hepatocytes or β-cells. However, human MAPCs have less plasticity than pluripotent stem cells (PSCs), as their ability to generate endodermal cells is not robust. Here we studied the role of 14

  6. Epigenetic Induction of Definitive and Pancreatic Endoderm Cell Fate in Human Fibroblasts

    NARCIS (Netherlands)

    Sambathkumar, Rangarajan; Kalo, Eric; Van Rossom, Rob; Faas, Marijke M.; de Vos, Paul; Verfaillie, Catherine M.

    2016-01-01

    Reprogramming can occur by the introduction of key transcription factors (TFs) as well as by epigenetic changes. We demonstrated that histone deacetylase inhibitor (HDACi) Trichostatin A (TSA) combined with a chromatin remodeling medium (CRM) induced expression of a number of definitive endoderm and

  7. Insulin redirects differentiation from cardiogenic mesoderm and endoderm to neuroectoderm in differentiating human embryonic stem cells.

    NARCIS (Netherlands)

    Freund, C.M.A.H.; Ward-van Oostwaard, D.; Monshouwer-Kloots, J.; van den Brink, S.; van Rooijen, M.A.; Xu, X.; Zweigerdt, R.; Mummery, C.L.; Passier, R.

    2008-01-01

    Human embryonic stem cells (hESC) can proliferate indefinitely while retaining the capacity to form derivatives of all three germ layers. We have reported previously that hESC differentiate into cardiomyocytes when cocultured with a visceral endoderm-like cell line (END-2). Insulin/insulin-like

  8. Generation of hepatocyte- and endocrine pancreatic-like cells from human induced endodermal progenitor cells

    NARCIS (Netherlands)

    Sambathkumar, Rangarajan; Akkerman, Renate; Dastidar, Sumitava; Roelandt, Philip; Kumar, Manoj; Bajaj, Manmohan; Mestre Rosa, Ana Rita; Helsen, Nicky; Vanslembrouck, Veerle; Kalo, Eric; Khurana, Satish; Laureys, Jos; Gysemans, Conny; Faas, Marijke M; de Vos, Paul; Verfaillie, Catherine M

    2018-01-01

    Multipotent Adult Progenitor Cells (MAPCs) are one potential stem cell source to generate functional hepatocytes or β-cells. However, human MAPCs have less plasticity than pluripotent stem cells (PSCs), as their ability to generate endodermal cells is not robust. Here we studied the role of 14

  9. Prostaglandin E2 Regulates Liver versus Pancreas Cell Fate Decisions and Endodermal Outgrowth

    Science.gov (United States)

    Nissim, Sahar; Sherwood, Richard I.; Wucherpfennig, Julia; Saunders, Diane; Harris, James M.; Esain, Virginie; Carroll, Kelli J.; Frechette, Gregory M.; Kim, Andrew J.; Hwang, Katie L.; Cutting, Claire C.; Elledge, Susanna; North, Trista E.; Goessling, Wolfram

    2014-01-01

    SUMMARY The liver and pancreas arise from common endodermal progenitors. How these distinct cell fates are specified is poorly understood. Here, we describe prostaglandin E2 (PGE2) as a regulator of endodermal fate specification during development. Modulating PGE2 activity has opposing effects on liver-versus-pancreas specification in zebrafish embryos as well as mouse endodermal progenitors. The PGE2 synthetic enzyme cox2a and receptor ep2a are patterned such that cells closest to PGE2 synthesis acquire a liver fate whereas more distant cells acquire a pancreas fate. PGE2 interacts with the bmp2b pathway to regulate fate specification. At later stages of development, PGE2 acting via the ep4a receptor promotes outgrowth of both the liver and pancreas. PGE2 remains important for adult organ growth, as it modulates liver regeneration. This work provides in vivo evidence that PGE2 may act as a morphogen to regulate cell fate decisions and outgrowth of the embryonic endodermal anlagen. PMID:24530296

  10. Primitive recursive realizability and basic propositional logic

    NARCIS (Netherlands)

    Plisko, Valery

    2007-01-01

    Two notions of primitive recursive realizability for arithmetic sentences are considered. The first one is strictly primitive recursive realizability introduced by Z. Damnjanovic in 1994. We prove that intuitionistic predicate logic is not sound with this kind of realizability. Namely there

  11. Primitive Based Action Representation and Recognition

    DEFF Research Database (Denmark)

    Baby, Sanmohan; Krüger, Volker

    2009-01-01

    a sequential and statistical     learning algorithm for   automatic detection of the action primitives and the action grammar   based on these primitives.  We model a set of actions using a   single HMM whose structure is learned incrementally as we observe   new types.   Actions are modeled with sufficient...

  12. Single-cell RNA sequencing reveals metallothionein heterogeneity during hESC differentiation to definitive endoderm

    Directory of Open Access Journals (Sweden)

    Junjie Lu

    2018-04-01

    Full Text Available Differentiation of human pluripotent stem cells towards definitive endoderm (DE is the critical first step for generating cells comprising organs such as the gut, liver, pancreas and lung. This in-vitro differentiation process generates a heterogeneous population with a proportion of cells failing to differentiate properly and maintaining expression of pluripotency factors such as Oct4. RNA sequencing of single cells collected at four time points during a 4-day DE differentiation identified high expression of metallothionein genes in the residual Oct4-positive cells that failed to differentiate to DE. Using X-ray fluorescence microscopy and multi-isotope mass spectrometry, we discovered that high intracellular zinc level corresponds with persistent Oct4 expression and failure to differentiate. This study improves our understanding of the cellular heterogeneity during in-vitro directed differentiation and provides a valuable resource to improve DE differentiation efficiency. Keywords: hPSC, Differentiation, Definitive endoderm, Heterogeneity, Single cell, RNA sequencing

  13. Enhanced Differentiation of Human Embryonic Stem Cells Toward Definitive Endoderm on Ultrahigh Aspect Ratio Nanopillars

    DEFF Research Database (Denmark)

    Rasmussen, Camilla Holzmann; Reynolds, Paul M.; Petersen, Dorthe Roenn

    2016-01-01

    highlighted that the properties of the physical environment, such as substrate stiffness, affect cellular behavior. Here, mass-produced, injection molded polycarbonate nanopillars are presented, where the surface mechanical properties, i.e., stiffness, can be controlled by the geometric design...... of the ultrahigh aspect ratio nanopillars (stiffness can be reduced by 25.000X). It is found that tall nanopillars, yielding softer surfaces, significantly enhance the induction of defi nitive endoderm cells from pluripotent human embryonic stem cells, resulting in more consistent differentiation of a pure...... population compared to planar control. By contrast, further differentiation toward the pancreatic endoderm is less successful on “soft” pillars when compared to “stiff ” pillars or control, indicating differential cues during the different stages of differentiation. To accompany the mechanical properties...

  14. Dynamic Primitives in the Control of Locomotion

    Directory of Open Access Journals (Sweden)

    Neville eHogan

    2013-06-01

    Full Text Available Humans achieve locomotor dexterity that far exceeds the capability of modern robots, yet this is achieved despite slower actuators, imprecise sensors and vastly slower communication. We propose that this spectacular performance arises from encoding motor commands in terms of dynamic primitives. We propose three primitives as a foundation for a comprehensive theoretical framework that can embrace a wide range of upper- and lower-limb behaviors. Building on previous work that suggested discrete and rhythmic movements as elementary dynamic behaviors, we define submovements and oscillations: As discrete movements cannot be combined with sufficient flexibility, we argue that suitably-defined submovements are primitives. As the term rhythmic may be ambiguous, we define oscillations as the corresponding class of primitives. We further propose mechanical impedances as a third class of dynamic primitives, necessary for interaction with the physical environment. Combination of these three classes of primitive requires care. One approach is through a generalized equivalent network: a virtual trajectory composed of simultaneous and/or sequential submovements and/or oscillations that interacts with mechanical impedances to produce observable forces and motions. Reliable experimental identification of these dynamic primitives presents challenges: Identification of mechanical impedances is exquisitely sensitive to assumptions about their dynamic structure; identification of submovements and oscillations is sensitive to their assumed form and to details of the algorithm used to extract them. Some methods to address these challenges are presented. Some implications of this theoretical framework for locomotor rehabilitation are considered.

  15. Dynamic primitives in the control of locomotion.

    Science.gov (United States)

    Hogan, Neville; Sternad, Dagmar

    2013-01-01

    Humans achieve locomotor dexterity that far exceeds the capability of modern robots, yet this is achieved despite slower actuators, imprecise sensors, and vastly slower communication. We propose that this spectacular performance arises from encoding motor commands in terms of dynamic primitives. We propose three primitives as a foundation for a comprehensive theoretical framework that can embrace a wide range of upper- and lower-limb behaviors. Building on previous work that suggested discrete and rhythmic movements as elementary dynamic behaviors, we define submovements and oscillations: as discrete movements cannot be combined with sufficient flexibility, we argue that suitably-defined submovements are primitives. As the term "rhythmic" may be ambiguous, we define oscillations as the corresponding class of primitives. We further propose mechanical impedances as a third class of dynamic primitives, necessary for interaction with the physical environment. Combination of these three classes of primitive requires care. One approach is through a generalized equivalent network: a virtual trajectory composed of simultaneous and/or sequential submovements and/or oscillations that interacts with mechanical impedances to produce observable forces and motions. Reliable experimental identification of these dynamic primitives presents challenges: identification of mechanical impedances is exquisitely sensitive to assumptions about their dynamic structure; identification of submovements and oscillations is sensitive to their assumed form and to details of the algorithm used to extract them. Some methods to address these challenges are presented. Some implications of this theoretical framework for locomotor rehabilitation are considered.

  16. A gene regulatory network controlling hhex transcription in the anterior endoderm of the organizer

    Science.gov (United States)

    Rankin, Scott A.; Kormish, Jay; Kofron, Matt; Jegga, Anil; Zorn, Aaron M.

    2011-01-01

    The homeobox gene hhex is one of the earliest markers of the anterior endoderm, which gives rise to foregut organs such as the liver, ventral pancreas, thyroid, and lungs. The regulatory networks controlling hhex transcription are poorly understood. In an extensive cis-regulatory analysis of the Xenopus hhex promoter we determined how the Nodal, Wnt, and BMP pathways and their downstream transcription factors regulate hhex expression in the gastrula organizer. We show that Nodal signaling, present throughout the endoderm, directly activates hhex transcription via FoxH1/Smad2 binding sites in the proximal −0.44 Kb promoter. This positive action of Nodal is suppressed in the ventral-posterior endoderm by Vent 1 and Vent2, homeodomain repressors that are induced by BMP signaling. Maternal Wnt/β-catenin on the dorsal side of the embryo cooperates with Nodal and indirectly activate hhex expression via the homeodomain activators Siamois and Twin. Siamois/Twin stimulate hhex transcription through two mechanisms: 1) They induce the expression of Otx2 and Lim1 and together Siamois, Twin, Otx2 and Lim1 appear to promote hhex transcription through homeobox sites in a Wnt-responsive element located between −0.65 to −0.55 Kb of the hhex promoter. 2) Siamois/Twin also induce the expression of the BMP-antagonists Chordin and Noggin, which are required to exclude Vents from the organizer allowing hhex transcription. This work reveals a complex network regulating anterior endoderm transcription in the early embryo. PMID:21215263

  17. Early development of zooxanthella-containing eggs of the corals Porites cylindrica and Montipora digitata: The endodermal localization of zooxanthellae.

    Science.gov (United States)

    Hirose, Mamiko; Hidaka, Michio

    2006-10-01

    We studied the early development of zooxanthellae-containing eggs of the scleractinian corals Porites cylindrica and Montipora digitata to elucidate how zooxanthellae become localized to the endoderm of planulae during the course of development. In both species, zooxanthellae were distributed evenly in the oocytes and delivered almost equally to the blastomeres during cleavage. In P. cylindrica, gastrulation occurred via delamination or ingression, and blastomeres containing zooxanthellae dropped into the blastocoel during gastrulation. Thus, zooxanthellae were restricted to the endodermal cells at the gastrula or early planula stage in P. cylindrica. In M. digitata, gastrulation occurred by a combination of invagination and epiboly to form a somewhat concave gastrula. Zooxanthellae were present in both endodermal and ectodermal cells of early planulae, but they disappeared from the ectoderm as the planulae matured. In our previous study on two species of Pocillopora, we found that zooxanthellae were localized in eggs as well as in embryos, and that blastomeres containing zooxanthellae later dropped into the blastocoel to become restricted to the endoderm (Hirose et al., 2000). The timing and mechanism of zooxanthella localization and types of gastrulation differed among species belonging to the three genera. These results suggest that zooxanthella localization in the embryos reflects the timing of the determination of presumptive endoderm cells and/or specificity of zooxanthellae toward presumptive endoderm cells.

  18. Use of a fluorescent membrane probe to identify zooxanthellae in hospite among dissociated endoderm cell culture from coral.

    Science.gov (United States)

    Chen, C-S; Lin, H-P; Yeh, C-C; Fang, L-S

    2005-12-01

    Preparation of homogeneous endoderm cells and culture is a prerequisite to understanding the cellular and molecular mechanism of endosymbiosis in the cnidarian-dinoflagellate association. During the cell isolation from the stony coral Euphyllia glabrescens, various amounts of symbiotic endoderm cells were found to release their symbionts (Symbiodinium spp., or zooxanthellae in generic usage) into the culture. Due to the bulky occupation by zooxanthellae inside the endoderm cell, the symbiotic endoderm cells, or zooxanthellae in hospite, are difficult to be distinguished from released zooxanthellae by microscopic examination. We now report a method for this identification using a fluorescent analogue of sphingomyelin, N-[5-(5,7-dimethyl boron dipyrromethene difluoride)-1-pentanoyl]-D-erythro-sphingosylphosphorylcholine (C(5)-DMB-SM). Incubation of symbiotic endoderm cells with C(5)-DMB-SM-defatted bovine serum albumin (DF-BSA) complex results in bright fluorescent membrane staining. Nevertheless, the membrane staining of free-living or released zooxanthellae by this complex is significantly decreased or even diminished. This method has provided a fast and reliable assay to identify symbiotic endoderm cells and will greatly accelerate the progress of endosymbiosis research.

  19. Bmp signaling mediates endoderm pouch morphogenesis by regulating Fgf signaling in zebrafish

    Science.gov (United States)

    Swartz, Mary E.; McCarthy, Neil; Norrie, Jacqueline L.; Eberhart, Johann K.

    2016-01-01

    The endodermal pouches are a series of reiterated structures that segment the pharyngeal arches and help pattern the vertebrate face. Multiple pathways regulate the complex process of endodermal development, including the Bone morphogenetic protein (Bmp) pathway. However, the role of Bmp signaling in pouch morphogenesis is poorly understood. Using genetic and chemical inhibitor approaches, we show that pouch morphogenesis requires Bmp signaling from 10-18 h post-fertilization, immediately following gastrulation. Blocking Bmp signaling during this window results in morphological defects to the pouches and craniofacial skeleton. Using genetic chimeras we show that Bmp signals directly to the endoderm for proper morphogenesis. Time-lapse imaging and analysis of reporter transgenics show that Bmp signaling is necessary for pouch outpocketing via the Fibroblast growth factor (Fgf) pathway. Double loss-of-function analyses demonstrate that Bmp and Fgf signaling interact synergistically in craniofacial development. Collectively, our analyses shed light on the tissue and signaling interactions that regulate development of the vertebrate face. PMID:27122171

  20. Effect of 3D Cultivation Conditions on the Differentiation of Endodermal Cells

    Science.gov (United States)

    Petrakova, O. S.; Ashapkin, V. V.; Voroteliak, E. A.; Bragin, E. Y.; Shtratnikova, V. Y.; Chernioglo, E. S.; Sukhanov, Y. V.; Terskikh, V. V.; Vasiliev, A. V.

    2012-01-01

    Cellular therapy of endodermal organs is one of the most important issues in modern cellular biology and biotechnology. One of the most promising directions in this field is the study of the transdifferentiation abilities of cells within the same germ layer. A method for anin vitroinvestigation of the cell differentiation potential (the cell culture in a three-dimensional matrix) is described in this article. Cell cultures of postnatal salivary gland cells and postnatal liver progenitor cells were obtained; their comparative analysis under 2D and 3D cultivation conditions was carried out. Both cell types have high proliferative abilities and can be cultivated for more than 20 passages. Under 2D cultivation conditions, the cells remain in an undifferentiated state. Under 3D conditions, they undergo differentiation, which was confirmed by a lower cell proliferation and by an increase in the differentiation marker expression. Salivary gland cells can undergo hepatic and pancreatic differentiation under 3D cultivation conditions. Liver progenitor cells also acquire a pancreatic differentiation capability under conditions of 3D cultivation. Thus, postnatal salivary gland cells exhibit a considerable differentiation potential within the endodermal germ layer and can be used as a promising source of endodermal cells for the cellular therapy of liver pathologies. Cultivation of cells under 3D conditions is a useful model for thein vitroanalysis of the cell differentiation potential. PMID:23346379

  1. Mechanism of primitive duct formation in the pancreas and submandibular glands: a role for SDF-1

    Directory of Open Access Journals (Sweden)

    Courtoy Pierre J

    2009-12-01

    Full Text Available Abstract Background The exocrine pancreas is composed of a branched network of ducts connected to acini. They are lined by a monolayered epithelium that derives from the endoderm and is surrounded by mesoderm-derived mesenchyme. The morphogenic mechanisms by which the ductal network is established as well as the signaling pathways involved in this process are poorly understood. Results By morphological analyzis of wild-type and mutant mouse embryos and using cultured embryonic explants we investigated how epithelial morphogenesis takes place and is regulated by chemokine signaling. Pancreas ontogenesis displayed a sequence of two opposite epithelial transitions. During the first transition, the monolayered and polarized endodermal cells give rise to tissue buds composed of a mass of non polarized epithelial cells. During the second transition the buds reorganize into branched and polarized epithelial monolayers that further differentiate into tubulo-acinar glands. We found that the second epithelial transition is controlled by the chemokine Stromal cell-Derived Factor (SDF-1. The latter is expressed by the mesenchyme, whereas its receptor CXCR4 is expressed by the epithelium. Reorganization of cultured pancreatic buds into monolayered epithelia was blocked in the presence of AMD3100, a SDF-1 antagonist. Analyzis of sdf1 and cxcr4 knockout embryos at the stage of the second epithelial transition revealed transient defective morphogenesis of the ventral and dorsal pancreas. Reorganization of a globular mass of epithelial cells in polarized monolayers is also observed during submandibular glands development. We found that SDF-1 and CXCR4 are expressed in this organ and that AMD3100 treatment of submandibular gland explants blocks its branching morphogenesis. Conclusion In conclusion, our data show that the primitive pancreatic ductal network, which is lined by a monolayered and polarized epithelium, forms by remodeling of a globular mass of non

  2. Discovery of Intrinsic Primitives on Triangle Meshes

    KAUST Repository

    Solomon, Justin; Ben-Chen, Mirela; Butscher, Adrian; Guibas, Leonidas

    2011-01-01

    The discovery of meaningful parts of a shape is required for many geometry processing applications, such as parameterization, shape correspondence, and animation. It is natural to consider primitives such as spheres, cylinders and cones

  3. Effects of Two Listening Strategies for Melodic Dictation

    Science.gov (United States)

    Buonviri, Nathan O.

    2017-01-01

    The purpose of this research was to examine effects of two listening strategies on melodic dictation scores. Fifty-four undergraduate music majors completed short tonal melodic dictations in a within-subjects design with three conditions: (a) no specified strategy in the instructions, (b) required listening before writing, and (c) required writing…

  4. Effects of a Preparatory Singing Pattern on Melodic Dictation Success

    Science.gov (United States)

    Buonviri, Nathan O.

    2015-01-01

    The purpose of this study was to investigate effects of a preparatory contextual singing pattern on melodic dictation test scores. Forty-nine undergraduate music education majors took melodic dictations under three conditions. After hearing an orienting chord sequence, they (1) sang a preparatory solfége pattern in the key, meter, and tempo of the…

  5. All-or-Nothing Dictator Games : A Field Experiment

    NARCIS (Netherlands)

    Bekkers, R.

    2006-01-01

    The dictator game has become well known for its results violating predictions based on ‘rational choice’ models of human behavior with orthodox assumptions on self-interest (Colin F. Camerer, 2003). Prosocial allocations in dictator games seem to suggest that there is some altruism in ‘human

  6. Discovery of Intrinsic Primitives on Triangle Meshes

    KAUST Repository

    Solomon, Justin

    2011-04-01

    The discovery of meaningful parts of a shape is required for many geometry processing applications, such as parameterization, shape correspondence, and animation. It is natural to consider primitives such as spheres, cylinders and cones as the building blocks of shapes, and thus to discover parts by fitting such primitives to a given surface. This approach, however, will break down if primitive parts have undergone almost-isometric deformations, as is the case, for example, for articulated human models. We suggest that parts can be discovered instead by finding intrinsic primitives, which we define as parts that posses an approximate intrinsic symmetry. We employ the recently-developed method of computing discrete approximate Killing vector fields (AKVFs) to discover intrinsic primitives by investigating the relationship between the AKVFs of a composite object and the AKVFs of its parts. We show how to leverage this relationship with a standard clustering method to extract k intrinsic primitives and remaining asymmetric parts of a shape for a given k. We demonstrate the value of this approach for identifying the prominent symmetry generators of the parts of a given shape. Additionally, we show how our method can be modified slightly to segment an entire surface without marking asymmetric connecting regions and compare this approach to state-of-the-art methods using the Princeton Segmentation Benchmark. © 2011 The Author(s).

  7. Wnt/β-catenin signalling regulates Sox17 expression and is essential for organizer and endoderm formation in the mouse.

    Science.gov (United States)

    Engert, Silvia; Burtscher, Ingo; Liao, W Perry; Dulev, Stanimir; Schotta, Gunnar; Lickert, Heiko

    2013-08-01

    Several signalling cascades are implicated in the formation and patterning of the three principal germ layers, but their precise temporal-spatial mode of action in progenitor populations remains undefined. We have used conditional gene deletion of mouse β-catenin in Sox17-positive embryonic and extra-embryonic endoderm as well as vascular endothelial progenitors to address the function of canonical Wnt signalling in cell lineage formation and patterning. Conditional mutants fail to form anterior brain structures and exhibit posterior body axis truncations, whereas initial blood vessel formation appears normal. Tetraploid rescue experiments reveal that lack of β-catenin in the anterior visceral endoderm results in defects in head organizer formation. Sox17 lineage tracing in the definitive endoderm (DE) shows a cell-autonomous requirement for β-catenin in midgut and hindgut formation. Surprisingly, wild-type posterior visceral endoderm (PVE) in midgut- and hindgut-deficient tetraploid chimera rescues the posterior body axis truncation, indicating that the PVE is important for tail organizer formation. Upon loss of β-catenin in the visceral endoderm and DE lineages, but not in the vascular endothelial lineage, Sox17 expression is not maintained, suggesting downstream regulation by canonical Wnt signalling. Strikingly, Tcf4/β-catenin transactivation complexes accumulated on Sox17 cis-regulatory elements specifically upon endoderm induction in an embryonic stem cell differentiation system. Together, these results indicate that the Wnt/β-catenin signalling pathway regulates Sox17 expression for visceral endoderm pattering and DE formation and provide the first functional evidence that the PVE is necessary for gastrula organizer gene induction and posterior axis development.

  8. Primitive and definitive erythropoiesis in mammals

    Directory of Open Access Journals (Sweden)

    James ePalis

    2014-01-01

    Full Text Available Red blood cells (RBCs, which constitute the most abundant cell type in the body, come in two distinct flavors- primitive and definitive. Definitive RBCs in mammals circulate as smaller, anucleate cells during fetal and postnatal life, while primitive RBCs circulate transiently in the early embryo as large, nucleated cells before ultimately enucleating. Both cell types are formed from lineage-committed progenitors that generate a series of morphologically identifiable precursors that enucleate to form mature RBCs. While definitive erythroid precursors mature extravascularly in the fetal liver and postnatal marrow in association with macrophage cells, primitive erythroid precursors mature as a semi-synchronous cohort in the embryonic bloodstream. While the cytoskeletal network is critical for the maintenance of cell shape and the deformability of definitive RBCs, little is known about the components and function of the cytoskeleton in primitive erythroblasts. Erythropoietin (EPO is a critical regulator of late-stage definitive, but not primitive, erythroid progenitor survival. However, recent studies indicate that EPO regulates multiple aspects of terminal maturation of primitive murine and human erythroid precursors, including cell survival, proliferation, and the rate of terminal maturation. Primitive and definitive erythropoiesis share central transcriptional regulators, including Gata1 and Klf1, but are also characterized by the differential expression and function of other regulators, including myb, Sox6, and Bcl11A. Flow cytometry-based methodologies, developed to purify murine and human stage-specific erythroid precursors, have enabled comparative global gene expression studies and are providing new insights into the biology of erythroid maturation.

  9. ZO-1 and ZO-2 are required for extra-embryonic endoderm integrity, primitive ectoderm survival and normal cavitation in embryoid bodies derived from mouse embryonic stem cells.

    Directory of Open Access Journals (Sweden)

    Dominic C Y Phua

    Full Text Available The Zonula Occludens proteins ZO-1 and ZO-2 are cell-cell junction-associated adaptor proteins that are essential for the structural and regulatory functions of tight junctions in epithelial cells and their absence leads to early embryonic lethality in mouse models. Here, we use the embryoid body, an in vitro peri-implantation mouse embryogenesis model, to elucidate and dissect the roles ZO-1 and ZO-2 play in epithelial morphogenesis and de novo tight junction assembly. Through the generation of individual or combined ZO-1 and ZO-2 null embryoid bodies, we show that their dual deletion prevents tight junction formation, resulting in the disorganization and compromised barrier function of embryoid body epithelial layers. The disorganization is associated with poor microvilli development, fragmented basement membrane deposition and impaired cavity formation, all of which are key epithelial tissue morphogenetic processes. Expression of Podocalyxin, which positively regulates the formation of microvilli and the apical membrane, is repressed in embryoid bodies lacking both ZO-1 and ZO-2 and this correlates with an aberrant submembranous localization of Ezrin. The null embryoid bodies thus give an insight into how the two ZO proteins influence early mouse embryogenesis and possible mechanisms underlying the embryonic lethal phenotype.

  10. Primitive Based Action Representation and recognition

    DEFF Research Database (Denmark)

    Baby, Sanmohan

    The presented work is aimed at designing a system that will model and recognize actions and its interaction with objects. Such a system is aimed at facilitating robot task learning. Activity modeling and recognition is very important for its potential applications in surveillance, human-machine i......The presented work is aimed at designing a system that will model and recognize actions and its interaction with objects. Such a system is aimed at facilitating robot task learning. Activity modeling and recognition is very important for its potential applications in surveillance, human......-machine interface, entertainment, biomechanics etc. Recent developments in neuroscience suggest that all actions are a compositions of smaller units called primitives. Current works based on primitives for action recognition uses a supervised framework for specifying the primitives. We propose a method to extract...... primitives automatically. These primitives are to be used to generate actions based on certain rules for combining. These rules are expressed as a stochastic context free grammar. A model merging approach is adopted to learn a Hidden Markov Model to t the observed data sequences. The states of the HMM...

  11. Anterior Visceral Endoderm SMAD4 Signaling Specifies Anterior Embryonic Patterning and Head Induction in Mice

    Science.gov (United States)

    Li, Cuiling; Li, Yi-Ping; Fu, Xin-Yuan; Deng, Chu-Xia

    2010-01-01

    SMAD4 serves as a common mediator for signaling of TGF-β superfamily. Previous studies illustrated that SMAD4-null mice die at embryonic day 6.5 (E6.5) due to failure of mesoderm induction and extraembryonic defects; however, functions of SMAD4 in each germ layer remain elusive. To investigate this, we disrupted SMAD4 in the visceral endoderm and epiblast, respectively, using a Cre-loxP mediated approach. We showed that mutant embryos lack of SMAD4 in the visceral endoderm (Smad4Co/Co;TTR-Cre) died at E7.5-E9.5 without head-fold and anterior embryonic structures. We demonstrated that TGF-β regulates expression of several genes, such as Hex1, Cer1, and Lim1, in the anterior visceral endoderm (AVE), and the failure of anterior embryonic development in Smad4Co/Co;TTR-Cre embryos is accompanied by diminished expression of these genes. Consistent with this finding, SMAD4-deficient embryoid bodies showed impaired responsiveness to TGF-β-induced gene expression and morphological changes. On the other hand, embryos carrying Cre-loxP mediated disruption of SMAD4 in the epiblasts exhibited relatively normal mesoderm and head-fold induction although they all displayed profound patterning defects in the later stages of gastrulation. Cumulatively, our data indicate that SMAD4 signaling in the epiblasts is dispensable for mesoderm induction although it remains critical for head patterning, which is significantly different from SMAD4 signaling in the AVE, where it specifies anterior embryonic patterning and head induction. PMID:20941375

  12. From Definitive Endoderm to Gut-a Process of Growth and Maturation

    DEFF Research Database (Denmark)

    Guiu, Jordi; Jensen, Kim B

    2015-01-01

    . In contrast, very little is known about the molecular mechanisms that trigger tissue maturation during development. With this review, our aim is to carefully provide a critical appraisal of the literature to give a state-of-the-art view of intestinal development. Starting from definitive endoderm...... at gastrulation to the emergence of a structure with mature properties, the tissue undergoes complex morphogenetic processes that rely on both biophysical changes and secreted signaling molecules. We will also discuss how new and exciting developments using in vitro models are likely to provide new insights...

  13. Tissue-specific regulation of mouse MicroRNA genes in endoderm-derived tissues

    OpenAIRE

    Gao, Yan; Schug, Jonathan; McKenna, Lindsay B.; Le Lay, John; Kaestner, Klaus H.; Greenbaum, Linda E.

    2010-01-01

    MicroRNAs fine-tune the activity of hundreds of protein-coding genes. The identification of tissue-specific microRNAs and their promoters has been constrained by the limited sensitivity of prior microRNA quantification methods. Here, we determine the entire microRNAome of three endoderm-derived tissues, liver, jejunum and pancreas, using ultra-high throughput sequencing. Although many microRNA genes are expressed at comparable levels, 162 microRNAs exhibited striking tissue-specificity. After...

  14. MR imaging of persistent primitive trigeminal artery

    International Nuclear Information System (INIS)

    Ashikaga, Ryuichiro; Araki, Yutaka; Ono, Yukihiko; Ishida, Osamu; Mabuchi, Nobuhisa.

    1997-01-01

    The persistent trigeminal artery is the most common anomaly of the primitive carotid-vertebrobasilar anastomoses. We reviewed MR images and MR angiographies of 11 patients with primitive trigeminal artery. In 8 of the 11 cases, PTA were identified with conventional long TR spin-echo images. In 8 of 11 cases, a hypoplastic basilar trunk associated with PTA was seen on both MR images and MR angiographies. In 7 of 11 cases, a hypoplasia or agenesis of the ipsilateral posterior communicating artery was seen on MR angiographies. (author)

  15. Smad4-dependent pathways control basement membrane deposition and endodermal cell migration at early stages of mouse development

    Directory of Open Access Journals (Sweden)

    Taylor Jennifer M

    2009-10-01

    Full Text Available Abstract Background Smad4 mutant embryos arrest shortly after implantation and display a characteristic shortened proximodistal axis, a significantly reduced epiblast, as well as a thickened visceral endoderm layer. Conditional rescue experiments demonstrate that bypassing the primary requirement for Smad4 in the extra-embryonic endoderm allows the epiblast to gastrulate. Smad4-independent TGF-β signals are thus sufficient to promote mesoderm formation and patterning. To further analyse essential Smad4 activities contributed by the extra-embryonic tissues, and characterise Smad4 dependent pathways in the early embryo, here we performed transcriptional profiling of Smad4 null embryonic stem (ES cells and day 4 embryoid bodies (EBs. Results Transcripts from wild-type versus Smad4 null ES cells and day 4 EBs were analysed using Illumina arrays. In addition to several known TGF-β/BMP target genes, we identified numerous Smad4-dependent transcripts that are mis-expressed in the mutants. As expected, mesodermal cell markers were dramatically down-regulated. We also observed an increase in non-canonical potency markers (Pramel7, Tbx3, Zscan4, germ cell markers (Aire, Tuba3a, Dnmt3l as well as early endoderm markers (Dpp4, H19, Dcn. Additionally, expression of the extracellular matrix (ECM remodelling enzymes Mmp14 and Mmp9 was decreased in Smad4 mutant ES and EB populations. These changes, in combination with increased levels of laminin alpha1, cause excessive basement membrane deposition. Similarly, in the context of the Smad4 null E6.5 embryos we observed an expanded basement membrane (BM associated with the thickened endoderm layer. Conclusion Smad4 functional loss results in a dramatic shift in gene expression patterns and in the endodermal cell lineage causes an excess deposition of, or an inability to breakdown and remodel, the underlying BM layer. These structural abnormalities probably disrupt reciprocal signalling between the epiblast and

  16. Ezh2 represses the basal cell lineage during lung endoderm development.

    Science.gov (United States)

    Snitow, Melinda E; Li, Shanru; Morley, Michael P; Rathi, Komal; Lu, Min Min; Kadzik, Rachel S; Stewart, Kathleen M; Morrisey, Edward E

    2015-01-01

    The development of the lung epithelium is regulated in a stepwise fashion to generate numerous differentiated and stem cell lineages in the adult lung. How these different lineages are generated in a spatially and temporally restricted fashion remains poorly understood, although epigenetic regulation probably plays an important role. We show that the Polycomb repressive complex 2 component Ezh2 is highly expressed in early lung development but is gradually downregulated by late gestation. Deletion of Ezh2 in early lung endoderm progenitors leads to the ectopic and premature appearance of Trp63+ basal cells that extend the entire length of the airway. Loss of Ezh2 also leads to reduced secretory cell differentiation. In their place, morphologically similar cells develop that express a subset of basal cell genes, including keratin 5, but no longer express high levels of either Trp63 or of standard secretory cell markers. This suggests that Ezh2 regulates the phenotypic switch between basal cells and secretory cells. Together, these findings show that Ezh2 restricts the basal cell lineage during normal lung endoderm development to allow the proper patterning of epithelial lineages during lung formation. © 2015. Published by The Company of Biologists Ltd.

  17. Evolution of Computational Toxicology-from Primitive ...

    Science.gov (United States)

    Presentation at the Health Canada seminar in Ottawa, ON, Canada on Nov. 15. 2016 Presentation at the Health Canada seminar in Ottawa, ON, Canada on Nov. 15. 2016 on the Evolution of Computational Toxicology-from Primitive Beginnings to Sophisticated Application

  18. Melville and the Tradition of Primitive Utopia.

    Science.gov (United States)

    Beauchamp, Gorman

    1981-01-01

    Discusses the relationships among the myth of the Golden Age, the concept of the Noble Savage, and the dream of Utopia. Uses Lewis Mumford's division of utopias into two basic types, i.e., reconstruction and escape utopias, to examine Herman Melville's "Typee" as an example of the primitive escapist utopia. (Editor/DMM)

  19. Social Preferences and Cognitive Reflection: Evidence from Dictator Game Experiment

    Directory of Open Access Journals (Sweden)

    Giovanni Benedetto Ponti

    2015-06-01

    Full Text Available This paper provides experimental evidence on the relationship between social preferences and cognitive abilities, which we measure using the Cognitive Reflection Test (CRT. We elicit social preferences by way of 24 dictatorial situations, in which the Dictator’s choice sets include i standard Dictator games, where increasing the Dictator’s payoff yields a loss for the Recipient, ii efficient Dicator games, where increasing the Dictator’s payoff also increases that the Recipient’s; as well as other situations in which iii either the Dictator’s or iv the Recipient’s monetary payoff is held constant. We partition our subject pool in three groups: reflective (scoring 2 or more in the CRT, impulsive (opting twice or more for the intuitive but wrong answers in the CRT and the remainder. We find that impulsive Dictators show a marked inequity aversion attitude, especially in standard Dictator Games. By contrast, reflective Dictators show lower distributional concerns, except for the situations in which the Dictators’ payoff is held constant. In this case, reflective Dictators give significantly more.

  20. Time-dependent patterning of the mesoderm and endoderm by Nodal signals in zebrafish

    Directory of Open Access Journals (Sweden)

    Dougan Scott T

    2007-03-01

    Full Text Available Abstract Background The vertebrate body plan is generated during gastrulation with the formation of the three germ layers. Members of the Nodal-related subclass of the TGF-β superfamily induce and pattern the mesoderm and endoderm in all vertebrates. In zebrafish, two nodal-related genes, called squint and cyclops, are required in a dosage-dependent manner for the formation of all derivatives of the mesoderm and endoderm. These genes are expressed dynamically during the blastula stages and may have different roles at different times. This question has been difficult to address because conditions that alter the timing of nodal-related gene expression also change Nodal levels. We utilized a pharmacological approach to conditionally inactivate the ALK 4, 5 and 7 receptors during the blastula stages without disturbing earlier signaling activity. This permitted us to directly examine when Nodal signals specify cell types independently of dosage effects. Results We show that two drugs, SB-431542 and SB-505124, completely block the response to Nodal signals when added to embryos after the mid-blastula transition. By blocking Nodal receptor activity at later stages, we demonstrate that Nodal signaling is required from the mid-to-late blastula period to specify sequentially, the somites, notochord, blood, Kupffer's vesicle, hatching gland, heart, and endoderm. Blocking Nodal signaling at late times prevents specification of cell types derived from the embryo margin, but not those from more animal regions. This suggests a linkage between cell fate and length of exposure to Nodal signals. Confirming this, cells exposed to a uniform Nodal dose adopt progressively more marginal fates with increasing lengths of exposure. Finally, cell fate specification is delayed in squint mutants and accelerated when Nodal levels are elevated. Conclusion We conclude that (1 Nodal signals are most active during the mid-to-late blastula stages, when nodal-related gene

  1. Modeling Inequity Aversion in a Dictator Game with Production

    Directory of Open Access Journals (Sweden)

    Ismael Rodriguez-Lara

    2012-10-01

    Full Text Available We expand upon the previous models of inequity aversion of Fehr and Schmidt [1], and Frohlich et al. [2], which assume that dictators get disutility if the final allocation of surplus deviates from the equal split (egalitarian principle or from the subjects' production (libertarian principle. In our model, dictators may also account for the way in which the surplus was generated. More precisely, our model incorporates the idea of liberal egalitarian ethics into the analysis, making it possible for dictators to divide the surplus according to the accountability principle, which states that subjects should only be rewarded for factors under their control. This fairness ideal does not hold subjects responsible for factors beyond their control in the production of the surplus, an idea that is absent in the models of inequity aversion cited above (JEL Codes: D3, D6, D63.

  2. Semantic Primitives of Time and Space in Hong Kong Cantonese.

    Science.gov (United States)

    Tong, Malindy; And Others

    1997-01-01

    Semantic primitives for time and space, as proposed in Natural Semantic Metalanguage theory, are examined for lexical equivalents in Hong Kong Cantonese. Temporal primitives are all found to have clear Cantonese exponents that can be combined as predicted with other metalanguage elements, with two exceptions. Spatial primitives all appear to have…

  3. Survival of the primitive mantle reservoir?

    Science.gov (United States)

    Huang, S.; Jacobsen, S. B.; Mukhopadhyay, S.

    2010-12-01

    The high-3He lavas are thought to originate from a deep primitive mantle source that has not been much modified since the formation of Earth’s core. Comparison of 4He/3He in MORBs and plume lavas indicate that the plume sources must be a lower mantle feature, in agreement with most geophysical inferences. However, the lithophile element isotope systems of plume lavas are not primitive. The idea that the high-3He source is significantly less processed and more primitive than MORB source is clearly supported by mixing trends in plots of 4He/3He versus Sr, Nd and Pb isotope ratios, which have been extrapolated to an inferred 4He/3He of ~17,000 (~43x the atmospheric ratio), a mantle reservoir named PHEM (Primitive HElium Mantle). Slightly lower 4He/3He, ~15,000, were reported for Baffin Island picrites. Recently, Jackson et al. (2010) claimed that some Baffin Island and Greenland picrites with single-stage Pb model ages of ~4.5 Ga have low 4He/3He, and argued that “their source is the most ancient accessible reservoir in the Earth’s mantle, and it may be parental to all mantle reservoirs”. However, the available data are insufficient to make such a claim, and we suggest an alternative interpretation. Specially: 1. Four out of ten Baffin Island and Greenland picrites used by Jackson et al. (2010) have 4He/3He higher than average MORB value and all are far removed from the lowest measured value of 15,000. 2. Five Greenland picrites which cluster around the 4.50 Gyr geochron (Jackson et al., 2010) form a curved 207Pb*/206Pb*-4He/3He trend. This trend is best explained as a mixing line, implying that the single-stage Pb ages of these lavas are meaningless. 3. In a 207Pb*/206Pb*-4He/3He plot, Koolau lavas from Hawaii overlap with Baffin Island and Greenland picrites. If Baffin Island and Greenland picrites represent melts from the primitive mantle based on their Pb and He isotopes (Jackson et al., 2010), a similar argument can be applied to Koolau lavas. However, it

  4. Hard Spheres on the Primitive Surface

    Science.gov (United States)

    Dotera, Tomonari; Takahashi, Yusuke

    2015-03-01

    Recently hierarchical structures associated with the gyroid in several soft-matter systems have been reported. One of fundamental questions is regular arrangement or tiling on minimal surfaces. We have found certain numbers of hard spheres per unit cell on the gyroid surface are entropically self-organized. Here, new results for the primitive surface are presented. 56/64/72 per unit cell on the primitive minimal surface are entropically self-organized. Numerical evidences for the fluid-solid transition as a function of hard sphere radius are obtained in terms of the acceptance ratio of Monte Carlo moves and order parameters. These arrangements, which are the extensions of the hexagonal arrangement on a flat surface, can be viewed as hyperbolic tiling on the Poincaré disk with a negative Gaussian curvature.

  5. Novel FOXA2 mutation causes Hyperinsulinism, Hypopituitarism with Craniofacial and Endoderm-derived organ abnormalities.

    Science.gov (United States)

    Giri, Dinesh; Vignola, Maria Lillina; Gualtieri, Angelica; Scagliotti, Valeria; McNamara, Paul; Peak, Matthew; Didi, Mohammed; Gaston-Massuet, Carles; Senniappan, Senthil

    2017-11-15

    Congenital hypopituitarism (CH) is characterized by the deficiency of one or more pituitary hormones and can present alone or in association with complex disorders. Congenital hyperinsulinism (CHI) is a disorder of unregulated insulin secretion despite hypoglycaemia that can occur in isolation or as part of a wider syndrome. Molecular diagnosis is unknown in many cases of CH and CHI. The underlying genetic etiology causing the complex phenotype of CH and CHI is unknown. In this study, we identified a de novo heterozygous mutation in the developmental transcription factor, forkhead box A2, FOXA2 (c.505T>C, p.S169P) in a child with CHI and CH with craniofacial dysmorphic features, choroidal coloboma and endoderm-derived organ malformations in liver, lung and gastrointestinal tract by whole exome sequencing. The mutation is at a highly conserved residue within the DNA binding domain. We demonstrated strong expression of Foxa2 mRNA in the developing hypothalamus, pituitary, pancreas, lungs and oesophagus of mouse embryos using in situ hybridization. Expression profiling on human embryos by immunohistochemistry showed strong expression of hFOXA2 in the neural tube, third ventricle, diencephalon and pancreas. Transient transfection of HEK293T cells with Wt (Wild type) hFOXA2 or mutant hFOXA2 showed an impairment in transcriptional reporter activity by the mutant hFOXA2. Further analyses using western blot assays showed that the FOXA2 p.(S169P) variant is pathogenic resulting in lower expression levels when compared with Wt hFOXA2. Our results show, for the first time, the causative role of FOXA2 in a complex congenital syndrome with hypopituitarism, hyperinsulinism and endoderm-derived organ abnormalities. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  6. Primary primitive neuroectodermal tumor of the orbit

    Directory of Open Access Journals (Sweden)

    Das Dipankar

    2009-01-01

    Full Text Available Primitive neuroectodermal tumor (PNET is a small round cell malignant tumor of neuroectodermal origin. Most of the PNETs occur in the central nervous system (CNS. PNETs recognized outside of CNS are diagnosed as peripheral PNET (pPNET. This tumor which expresses MIC-2 gene (CD99 seems to be least aggressive after complete tumor resection. We describe a rare case of PNET in a young girl.

  7. Accounting for primitive terms in mathematics

    Directory of Open Access Journals (Sweden)

    D.F.M. Strauss

    2005-07-01

    Full Text Available The philosophical problem of unity and diversity entails a challenge to the rationalist aim to define everything. Definitions of this kind surface in various academic disciplines in formulations like uniqueness, irreducibility, and what has acquired the designation “primitive terms”. Not even the most “exact” disciplines, such as mathematics, can avoid the implications entailed in giving an account of such primitive terms. A mere look at the historical development of mathematics highlights the fact that alternative perspectives prevailed – from the arithmeticism of Pythagoreanism, the eventual geometrisation of mathematics after the discovery of incommensurability up to the revival of arithmeticism in the mathematics of Cauchy, Weierstrass, Dedekind and Cantor (with the later orientation of Frege, who completed the circle by returning to the view that mathematics essentially is geometry. An assessment of logicism and axiomatic formalism is followed by looking at the primitive meaning of wholeness (and the whole-parts relation. With reference to the views of Hilbert, Weyl and Bernays the article concludes by suggesting that in opposition to arithmeticism and geometricism an alternative option ought to be pursued – one in which both the uniqueness and mutual coherence between the aspects of number and space are acknowledged.

  8. Microfluidic assay of the deformability of primitive erythroblasts.

    Science.gov (United States)

    Zhou, Sitong; Huang, Yu-Shan; Kingsley, Paul D; Cyr, Kathryn H; Palis, James; Wan, Jiandi

    2017-09-01

    Primitive erythroblasts (precursors of red blood cells) enter vascular circulation during the embryonic period and mature while circulating. As a result, primitive erythroblasts constantly experience significant hemodynamic shear stress. Shear-induced deformation of primitive erythroblasts however, is poorly studied. In this work, we examined the deformability of primitive erythroblasts at physiologically relevant flow conditions in microfluidic channels and identified the regulatory roles of the maturation stage of primitive erythroblasts and cytoskeletal protein 4.1 R in shear-induced cell deformation. The results showed that the maturation stage affected the deformability of primitive erythroblasts significantly and that primitive erythroblasts at later maturational stages exhibited a better deformability due to a matured cytoskeletal structure in the cell membrane.

  9. Teaching Melodic Dictation in Advanced Placement Music Theory

    Science.gov (United States)

    Paney, Andrew S.; Buonviri, Nathan O.

    2014-01-01

    In this study approaches to teaching melodic dictation skills used by Advanced Placement (AP) Music Theory teachers were examined. Twelve high school teachers from four states were interviewed. Four themes emerged from the interview transcripts: cognitive frameworks, processing strategies, rhythm, and course design. Participants generally…

  10. The bystander effect in an N-person dictator game

    NARCIS (Netherlands)

    Panchanathan, K.; Frankenhuis, W.E.; Silk, J.B.

    2013-01-01

    Dozens of studies show that bystanders are less likely to help victims as bystander number increases. However, these studies model one particular situation, in which victims need only one helper. Using a multi-player dictator game, we study a different but common situation, in which a recipient’s

  11. The values of ex-ante and ex-post communication in dictator games

    OpenAIRE

    Pascal Langenbach

    2014-01-01

    In the dictator game, the recipient's opportunity to send a message to the dictator increases giving. This paperreports two experimentswhich study how the timing of messages affects dictators' decisions (experiment 1) and which value recipients attach to communication opportunities (experiment 2). The first experiment shows that the effect of communication on dictator giving is equally strong when the recipient can send a message before or after the dictator has decided. However, recipients i...

  12. Primary primitive neuroectodermal tumor of the cervix

    Science.gov (United States)

    Li, Bo; Ouyang, Ling; Han, Xue; Zhou, Yang; Tong, Xin; Zhang, Shulang; Zhang, Qingfu

    2013-01-01

    Primary primitive neuroectodermal tumors (PNETs) are rare and high-grade malignant tumors that mostly occur in children and young adults. The most common sites are the trunk, limbs, and retroperitoneum. Herein, we present a case of a PNET involving the cervix uteri in a 27-year-old woman. The lesion showed characteristic histologic features of a PNET and was positive for the immunohistochemical markers cluster of differentiation (CD) 99, vimentin, neuron-specific enolase, neural cell adhesion molecule 1 (CD56), and CD117 (c-kit), further defining the tumor while helping to confirm PNET. The clinical Stage IIIB tumor was treated with chemotherapy and radiotherapy. PMID:23836982

  13. An Overview of DRAM-Based Security Primitives

    Directory of Open Access Journals (Sweden)

    Nikolaos Athanasios Anagnostopoulos

    2018-03-01

    Full Text Available Recent developments have increased the demand for adequate security solutions, based on primitives that cannot be easily manipulated or altered, such as hardware-based primitives. Security primitives based on Dynamic Random Access Memory (DRAM can provide cost-efficient and practical security solutions, especially for resource-constrained devices, such as hardware used in the Internet of Things (IoT, as DRAMs are an intrinsic part of most contemporary computer systems. In this work, we present a comprehensive overview of the literature regarding DRAM-based security primitives and an extended classification of it, based on a number of different criteria. In particular, first, we demonstrate the way in which DRAMs work and present the characteristics being exploited for the implementation of security primitives. Then, we introduce the primitives that can be implemented using DRAM, namely Physical Unclonable Functions (PUFs and True Random Number Generators (TRNGs, and present the applications of each of the two types of DRAM-based security primitives. We additionally proceed to assess the security such primitives can provide, by discussing potential attacks and defences, as well as the proposed security metrics. Subsequently, we also compare these primitives to other hardware-based security primitives, noting their advantages and shortcomings, and proceed to demonstrate their potential for commercial adoption. Finally, we analyse our classification methodology, by reviewing the criteria employed in our classification and examining their significance.

  14. Transcriptome profiling to identify ATRA-responsive genes in human iPSC-derived endoderm for high-throughput point of departure analysis (SOT Annual Meeting)

    Science.gov (United States)

    Toxicological tipping points occur at chemical concentrations that overwhelm a cell’s adaptive response leading to permanent effects. We focused on retinoid signaling in differentiating endoderm to identify developmental pathways for tipping point analysis. Human induced pluripot...

  15. Changes in microRNA expression during differentiation of embryonic and induced pluripotent stem cells to definitive endoderm.

    Science.gov (United States)

    Francis, Natalie; Moore, Melanie; Asan, Simona G; Rutter, Guy A; Burns, Chris

    2015-01-01

    Pluripotent stem cells, including embryonic stem cells (ESCs) and induced pluripotent stem cells (iPSCs), have the potential to treat type 1 diabetes through cell replacement therapy. However, the protocols used to generate insulin-expressing cells in vitro frequently result in cells which have an immature phenotype and are functionally restricted. MicroRNAs (miRNAs) are now known to be important in cell fate specification, and a unique miRNA signature characterises pancreatic development at the definitive endoderm stage. Several studies have described differences in miRNA expression between ESCs and iPSCs. Here we have used microarray analysis both to identify miRNAs up- or down-regulated upon endoderm formation, and also miRNAs differentially expressed between ESCs and iPSCs. Several miRNAs fulfilling both these criteria were identified, suggesting that differences in the expression of these miRNAs may affect the ability of pluripotent stem cells to differentiate into definitive endoderm. The expression of these miRNAs was validated by qRT-PCR, and the relationship between one of these miRNAs, miR-151a-5p, and its predicted target gene, SOX17, was investigated by luciferase assay, and suggested an interaction between miR-151a-5p and this key transcription factor. In conclusion, these findings demonstrate a unique miRNA expression pattern for definitive endoderm derived from both embryonic and induced pluripotent stem cells. Copyright © 2015 Elsevier B.V. All rights reserved.

  16. Primitive Accumulation and Temporalities of Capitalism

    Directory of Open Access Journals (Sweden)

    Joanna Bednarek

    2015-04-01

    Full Text Available The main thesis of the article is the statement that capitalism is composed of many different, incoherent temporalities, as well as that apprehension of capitalism from the angle of primitive accumulation enables the more accurate grasp of the modes of its functioning, including the complexity created by the interactions of the temporalities mentionned. The problem of primitive accumulation is, as Sandro Mezzadra proves, a good starting point for analysing this issue. It allows us to pose two questions: first, the question of the relation between the historical dimension and the structural logic of capitalism; second, the question of hierarchical relation between the center and the periphery of the capitalist system.Dipesh Chakrabarty’s project of ‘provincializing Europe’ proves helpful here, as it’s goal is deconstruction of the categories of progress, modernization and the capital with its abstract structure. The aim is not to negate the fact that capitalist abstraction is a real force, but to show that this force develops by means of constant assimiliation of the other – redefined as ‘backward’ or archaic. The linear scheme is in force, because it is the main mechanism of imposing the power of capital; as such, it is not politically neutral.

  17. What Behaviors are Disapproved? Experimental Evidence from Five Dictator Games

    Directory of Open Access Journals (Sweden)

    Marc Vorsatz

    2012-04-01

    Full Text Available The literature on social norms has often stressed that social disapproval is crucial to foster compliance with norms and promote fair and cooperative behavior. With this in mind, we explore the disapproval of allocation decisions using experimental data from five dictator games with a feedback stage. Our data suggests that subjects are heterogeneous in their disapproval patterns, distinguishing two main groups: (1 Subjects who only disapprove choices that harm them, and (2 subjects who disapprove socially inefficient choices.

  18. Definitive Endoderm Formation from Plucked Human Hair-Derived Induced Pluripotent Stem Cells and SK Channel Regulation

    Directory of Open Access Journals (Sweden)

    Anett Illing

    2013-01-01

    Full Text Available Pluripotent stem cells present an extraordinary powerful tool to investigate embryonic development in humans. Essentially, they provide a unique platform for dissecting the distinct mechanisms underlying pluripotency and subsequent lineage commitment. Modest information currently exists about the expression and the role of ion channels during human embryogenesis, organ development, and cell fate determination. Of note, small and intermediate conductance, calcium-activated potassium channels have been reported to modify stem cell behaviour and differentiation. These channels are broadly expressed throughout human tissues and are involved in various cellular processes, such as the after-hyperpolarization in excitable cells, and also in differentiation processes. To this end, human induced pluripotent stem cells (hiPSCs generated from plucked human hair keratinocytes have been exploited in vitro to recapitulate endoderm formation and, concomitantly, used to map the expression of the SK channel (SKCa subtypes over time. Thus, we report the successful generation of definitive endoderm from hiPSCs of ectodermal origin using a highly reproducible and robust differentiation system. Furthermore, we provide the first evidence that SKCas subtypes are dynamically regulated in the transition from a pluripotent stem cell to a more lineage restricted, endodermal progeny.

  19. Transplantation of Human Pancreatic Endoderm Cells Reverses Diabetes Post Transplantation in a Prevascularized Subcutaneous Site

    Directory of Open Access Journals (Sweden)

    Andrew R. Pepper

    2017-06-01

    Full Text Available Beta-cell replacement therapy is an effective means to restore glucose homeostasis in select humans with autoimmune diabetes. The scarcity of “healthy” human donor pancreata restricts the broader application of this effective curative therapy. “β-Like” cells derived from human embryonic stem cells (hESC, with the capacity to secrete insulin in a glucose-regulated manner, have been developed in vitro, with limitless capacity for expansion. Here we report long-term diabetes correction in mice transplanted with hESC-derived pancreatic endoderm cells (PECs in a prevascularized subcutaneous site. This advancement mitigates chronic foreign-body response, utilizes a device- and growth factor-free approach, facilitates in vivo differentiation of PECs into glucose-responsive insulin-producing cells, and reliably restores glycemic control. Basal and stimulated human C-peptide secretion was detected throughout the study, which was abolished upon graft removal. Recipient mice demonstrated physiological clearance of glucose in response to metabolic challenge and safely retrieved grafts contained viable glucose regulatory cells.

  20. Changes in glycosaminoglycan structure on differentiation of human embryonic stem cells towards mesoderm and endoderm lineages.

    Science.gov (United States)

    Gasimli, Leyla; Hickey, Anne Marie; Yang, Bo; Li, Guoyun; dela Rosa, Mitche; Nairn, Alison V; Kulik, Michael J; Dordick, Jonathan S; Moremen, Kelley W; Dalton, Stephen; Linhardt, Robert J

    2014-06-01

    Proteoglycans are found on the cell surface and in the extracellular matrix, and serve as prime sites for interaction with signaling molecules. Proteoglycans help regulate pathways that control stem cell fate, and therefore represent an excellent tool to manipulate these pathways. Despite their importance, there is a dearth of data linking glycosaminoglycan structure within proteoglycans with stem cell differentiation. Human embryonic stem cell line WA09 (H9) was differentiated into early mesoderm and endoderm lineages, and the glycosaminoglycanomic changes accompanying these transitions were studied using transcript analysis, immunoblotting, immunofluorescence and disaccharide analysis. Pluripotent H9 cell lumican had no glycosaminoglycan chains whereas in splanchnic mesoderm lumican was glycosaminoglycanated. H9 cells have primarily non-sulfated heparan sulfate chains. On differentiation towards splanchnic mesoderm and hepatic lineages N-sulfo group content increases. Differences in transcript expression of NDST1, HS6ST2 and HS6ST3, three heparan sulfate biosynthetic enzymes, within splanchnic mesoderm cells compared to H9 cells correlate to changes in glycosaminoglycan structure. Differentiation of embryonic stem cells markedly changes the proteoglycanome. The glycosaminoglycan biosynthetic pathway is complex and highly regulated, and therefore, understanding the details of this pathway should enable better control with the aim of directing stem cell differentiation. Copyright © 2013 Elsevier B.V. All rights reserved.

  1. Adapting a Computerized Medical Dictation System to Prepare Academic Papers in Radiology.

    Science.gov (United States)

    Sánchez, Yadiel; Prabhakar, Anand M; Uppot, Raul N

    2017-09-14

    Everyday radiologists use dictation software to compose clinical reports of imaging findings. The dictation software is tailored for medical use and to the speech pattern of each radiologist. Over the past 10 years we have used dictation software to compose academic manuscripts, correspondence letters, and texts of educational exhibits. The advantages of using voice dictation is faster composition of manuscripts. However, use of such software requires preparation. The purpose of this article is to review the steps of adapting a clinical dictation software for dictating academic manuscripts and detail the advantages and limitations of this technique. Copyright © 2017 Elsevier Inc. All rights reserved.

  2. Primitive chain network simulations of probe rheology.

    Science.gov (United States)

    Masubuchi, Yuichi; Amamoto, Yoshifumi; Pandey, Ankita; Liu, Cheng-Yang

    2017-09-27

    Probe rheology experiments, in which the dynamics of a small amount of probe chains dissolved in immobile matrix chains is discussed, have been performed for the development of molecular theories for entangled polymer dynamics. Although probe chain dynamics in probe rheology is considered hypothetically as single chain dynamics in fixed tube-shaped confinement, it has not been fully elucidated. For instance, the end-to-end relaxation of probe chains is slower than that for monodisperse melts, unlike the conventional molecular theories. In this study, the viscoelastic and dielectric relaxations of probe chains were calculated by primitive chain network simulations. The simulations semi-quantitatively reproduced the dielectric relaxation, which reflects the effect of constraint release on the end-to-end relaxation. Fair agreement was also obtained for the viscoelastic relaxation time. However, the viscoelastic relaxation intensity was underestimated, possibly due to some flaws in the model for the inter-chain cross-correlations between probe and matrix chains.

  3. Design and Analysis of Symmetric Primitives

    DEFF Research Database (Denmark)

    Lauridsen, Martin Mehl

    . In the second part, we delve into the matter of the various aspects of designing a symmetric cryptographic primitive. We start by considering generalizations of the widely acclaimed Advanced Encryption Standard (AES) block cipher. In particular, our focus is on a component operation in the cipher which permutes...... analyze and implement modes recommended by the National Institute of Standards and Technology (NIST), as well as authenticated encryption modes from the CAESAR competition, when instantiated with the AES. The data processed in our benchmarking has sizes representative to that of typical Internet traffic...... linear cryptanalysis. We apply this model to the standardized block cipher PRESENT. Finally, we present very generic attacks on two authenticated encryption schemes, AVALANCHE and RBS, by pointing out severe design flaws that can be leveraged to fully recover the secret key with very low complexity...

  4. Electron correlation effects in the presence of non-symmetry dictated ...

    Indian Academy of Sciences (India)

    We numerically study the effect of non-symmetry dictated nodes (NSDN) on electron ... the absence of NSDN, attractive interaction between electrons give such an ... and the violation of parity effect, we first explain what are symmetry dictated.

  5. Action Recognition in Semi-synthetic Images using Motion Primitives

    DEFF Research Database (Denmark)

    Fihl, Preben; Holte, Michael Boelstoft; Moeslund, Thomas B.

    This technical report describes an action recognition approach based on motion primitives. A few characteristic time instances are found in a sequence containing an action and the action is classified from these instances. The characteristic instances are defined solely on the human motion, hence...... motion primitives. The motion primitives are extracted by double difference images and represented by four features. In each frame the primitive, if any, that best explains the observed data is identified. This leads to a discrete recognition problem since a video sequence will be converted into a string...... containing a sequence of symbols, each representing a primitive. After pruning the string a probabilistic Edit Distance classifier is applied to identify which action best describes the pruned string. The method is evaluated on five one-arm gestures. A test is performed with semi-synthetic input data...

  6. Graphene Edges Dictate the Morphology of Nanoparticles during Catalytic Channeling

    DEFF Research Database (Denmark)

    Pizzocchero, Filippo; Vanin, Marco; Kling, Jens

    2014-01-01

    We perform in-situ transmission electron microscopy (TEM) experiments of silver nanoparticles channeling on mono-, bi-, and few-layer graphene and discover that the interactions in the one-dimensional particle–graphene contact line are sufficiently strong so as to dictate the three-dimensional sh......We perform in-situ transmission electron microscopy (TEM) experiments of silver nanoparticles channeling on mono-, bi-, and few-layer graphene and discover that the interactions in the one-dimensional particle–graphene contact line are sufficiently strong so as to dictate the three......-dimensional shape of the nanoparticles. We find a characteristic faceted shape in particles channeling along graphene ⟨100⟩ directions that is lost during turning and thus represents a dynamic equilibrium state of the graphene–particle system. We propose a model for the mechanism of zigzag edge formation...... and an explanation of the rate-limiting step for this process, supported by density functional theory (DFT) calculations, and obtain a good agreement between the DFT-predicted and experimentally obtained activation energies of 0.39 and 0.56 eV, respectively. Understanding the origin of the channels' orientation...

  7. Child-centered reading intervention: See, talk, dictate, read, write!

    Directory of Open Access Journals (Sweden)

    Muhammet BAŞTUĞ

    2016-06-01

    Full Text Available Poor reading achievement of children in elementary schools has been one of the major concerns in education. The aim of this study is to examine the effectiveness of a child-centered reading intervention in eliminating the reading problems of a student with poor reading achievement. The research was conducted with a student having difficulty in reading. A reading intervention was designed that targeted multiple areas of reading and aimed to improve reading skills through the use of multiple strategies. This intervention is child-centered and includes visual aids, talking, dictating, reading and writing stages. The study was performed in 35 sessions consisting of stages of a single sentence (5 sessions, two sentences (5 sessions, three sentences (20 sessions and the text stage (5 sessions. The intervention sessions were audio-taped. These recordings and the written responses to the reading comprehension questions provided the data for analysis. The findings on the reading intervention revealed positive outcomes. The student exhibited certain improvements at the levels of reading, reading rate and reading comprehension. These results were discussed in the literature and the findings suggest that child-centered reading strategies such as talking, dictating and writing should be the main focus of instruction for students with low reading literacy achievement to enable these students to meet the demands of the curriculum.

  8. Direct contact with endoderm-like cells efficiently induces cardiac progenitors from mouse and human pluripotent stem cells.

    Directory of Open Access Journals (Sweden)

    Hideki Uosaki

    Full Text Available RATIONALE: Pluripotent stem cell-derived cardiac progenitor cells (CPCs have emerged as a powerful tool to study cardiogenesis in vitro and a potential cell source for cardiac regenerative medicine. However, available methods to induce CPCs are not efficient or require high-cost cytokines with extensive optimization due to cell line variations. OBJECTIVE: Based on our in-vivo observation that early endodermal cells maintain contact with nascent pre-cardiac mesoderm, we hypothesized that direct physical contact with endoderm promotes induction of CPCs from pluripotent cells. METHOD AND RESULT: To test the hypothesis, we cocultured mouse embryonic stem (ES cells with the endodermal cell line End2 by co-aggregation or End2-conditioned medium. Co-aggregation resulted in strong induction of Flk1(+ PDGFRa(+ CPCs in a dose-dependent manner, but the conditioned medium did not, indicating that direct contact is necessary for this process. To determine if direct contact with End2 cells also promotes the induction of committed cardiac progenitors, we utilized several mouse ES and induced pluripotent (iPS cell lines expressing fluorescent proteins under regulation of the CPC lineage markers Nkx2.5 or Isl1. In agreement with earlier data, co-aggregation with End2 cells potently induces both Nkx2.5(+ and Isl1(+ CPCs, leading to a sheet of beating cardiomyocytes. Furthermore, co-aggregation with End2 cells greatly promotes the induction of KDR(+ PDGFRa(+ CPCs from human ES cells. CONCLUSIONS: Our co-aggregation method provides an efficient, simple and cost-effective way to induce CPCs from mouse and human pluripotent cells.

  9. Pdx1 and Ngn3 overexpression enhances pancreatic differentiation of mouse ES cell-derived endoderm population.

    Science.gov (United States)

    Kubo, Atsushi; Stull, Robert; Takeuchi, Mitsuaki; Bonham, Kristina; Gouon-Evans, Valerie; Sho, Masayuki; Iwano, Masayuki; Saito, Yoshihiko; Keller, Gordon; Snodgrass, Ralph

    2011-01-01

    In order to define the molecular mechanisms regulating the specification and differentiation of pancreatic β-islet cells, we investigated the effect of upregulating Pdx1 and Ngn3 during the differentiation of the β-islet-like cells from murine embryonic stem (ES) cell-derived activin induced-endoderm. Induced overexpression of Pdx1 resulted in a significant upregulation of insulin (Ins1 and Ins2), and other pancreas-related genes. To enhance the developmental progression from the pancreatic bud to the formation of the endocrine lineages, we induced the overexpression express of Ngn3 together with Pdx1. This combination dramatically increased the level and timing of maximal Ins1 mRNA expression to approximately 100% of that found in the βTC6 insulinoma cell line. Insulin protein and C-peptide expression was confirmed by immunohistochemistry staining. These inductive effects were restricted to c-kit(+) endoderm enriched EB-derived populations suggesting that Pdx1/Ngn3 functions after the specification of pancreatic endoderm. Although insulin secretion was stimulated by various insulin secretagogues, these cells had only limited glucose response. Microarray analysis was used to evaluate the expression of a broad spectrum of pancreatic endocrine cell-related genes as well as genes associated with glucose responses. Taken together, these findings demonstrate the utility of manipulating Pdx1 and Ngn3 expression in a stage-specific manner as an important new strategy for the efficient generation of functionally immature insulin-producing β-islet cells from ES cells.

  10. Pdx1 and Ngn3 overexpression enhances pancreatic differentiation of mouse ES cell-derived endoderm population.

    Directory of Open Access Journals (Sweden)

    Atsushi Kubo

    Full Text Available In order to define the molecular mechanisms regulating the specification and differentiation of pancreatic β-islet cells, we investigated the effect of upregulating Pdx1 and Ngn3 during the differentiation of the β-islet-like cells from murine embryonic stem (ES cell-derived activin induced-endoderm. Induced overexpression of Pdx1 resulted in a significant upregulation of insulin (Ins1 and Ins2, and other pancreas-related genes. To enhance the developmental progression from the pancreatic bud to the formation of the endocrine lineages, we induced the overexpression express of Ngn3 together with Pdx1. This combination dramatically increased the level and timing of maximal Ins1 mRNA expression to approximately 100% of that found in the βTC6 insulinoma cell line. Insulin protein and C-peptide expression was confirmed by immunohistochemistry staining. These inductive effects were restricted to c-kit(+ endoderm enriched EB-derived populations suggesting that Pdx1/Ngn3 functions after the specification of pancreatic endoderm. Although insulin secretion was stimulated by various insulin secretagogues, these cells had only limited glucose response. Microarray analysis was used to evaluate the expression of a broad spectrum of pancreatic endocrine cell-related genes as well as genes associated with glucose responses. Taken together, these findings demonstrate the utility of manipulating Pdx1 and Ngn3 expression in a stage-specific manner as an important new strategy for the efficient generation of functionally immature insulin-producing β-islet cells from ES cells.

  11. Endoderm development in Caenorhabditis elegans: the synergistic action of ELT-2 and -7 mediates the specification→differentiation transition.

    Science.gov (United States)

    Sommermann, Erica M; Strohmaier, Keith R; Maduro, Morris F; Rothman, Joel H

    2010-11-01

    The transition from specification of cell identity to the differentiation of cells into an appropriate and enduring state is critical to the development of embryos. Transcriptional profiling in Caenorhabditis elegans has revealed a large number of genes that are expressed in the fully differentiated intestine; however, no regulatory factor has been found to be essential to initiate their expression once the endoderm has been specified. These gut-expressed genes possess a preponderance of GATA factor binding sites and one GATA factor, ELT-2, fulfills the expected characteristics of a key regulator of these genes based on its persistent expression exclusively in the developing and differentiated intestine and its ability to bind these regulatory sites. However, a striking characteristic of elt-2(0) knockout mutants is that while they die shortly after hatching owing to an obstructed gut passage, they nevertheless contain a gut that has undergone complete morphological differentiation. We have discovered a second gut-specific GATA factor, ELT-7, that profoundly synergizes with ELT-2 to create a transcriptional switch essential for gut cell differentiation. ELT-7 is first expressed in the early endoderm lineage and, when expressed ectopically, is sufficient to activate gut differentiation in nonendodermal progenitors. elt-7 is transcriptionally activated by the redundant endoderm-specifying factors END-1 and -3, and its product in turn activates both its own expression and that of elt-2, constituting an apparent positive feedback system. While elt-7 loss-of-function mutants lack a discernible phenotype, simultaneous loss of both elt-7 and elt-2 results in a striking all-or-none block to morphological differentiation of groups of gut cells with a region-specific bias, as well as reduced or abolished gut-specific expression of a number of terminal differentiation genes. ELT-2 and -7 synergize not only in activation of gene expression but also in repression of a gene that

  12. spib is required for primitive myeloid development in Xenopus.

    Science.gov (United States)

    Costa, Ricardo M B; Soto, Ximena; Chen, Yaoyao; Zorn, Aaron M; Amaya, Enrique

    2008-09-15

    Vertebrate blood formation occurs in 2 spatially and temporally distinct waves, so-called primitive and definitive hematopoiesis. Although definitive hematopoiesis has been extensively studied, the development of primitive myeloid blood has received far less attention. In Xenopus, primitive myeloid cells originate in the anterior ventral blood islands, the equivalent of the mammalian yolk sac, and migrate out to colonize the embryo. Using fluorescence time-lapse video microscopy, we recorded the migratory behavior of primitive myeloid cells from their birth. We show that these cells are the first blood cells to differentiate in the embryo and that they are efficiently recruited to embryonic wounds, well before the establishment of a functional vasculature. Furthermore, we isolated spib, an ETS transcription factor, specifically expressed in primitive myeloid precursors. Using spib antisense morpholino knockdown experiments, we show that spib is required for myeloid specification, and, in its absence, primitive myeloid cells retain hemangioblast-like characteristics and fail to migrate. Thus, we conclude that spib sits at the top of the known genetic hierarchy that leads to the specification of primitive myeloid cells in amphibians.

  13. Action Recognition Using Motion Primitives and Probabilistic Edit Distance

    DEFF Research Database (Denmark)

    Fihl, Preben; Holte, Michael Boelstoft; Moeslund, Thomas B.

    2006-01-01

    In this paper we describe a recognition approach based on the notion of primitives. As opposed to recognizing actions based on temporal trajectories or temporal volumes, primitive-based recognition is based on representing a temporal sequence containing an action by only a few characteristic time...... into a string containing a sequence of symbols, each representing a primitives. After pruning the string a probabilistic Edit Distance classifier is applied to identify which action best describes the pruned string. The approach is evaluated on five one-arm gestures and the recognition rate is 91...

  14. Pervasive orbital eccentricities dictate the habitability of extrasolar earths.

    Science.gov (United States)

    Kita, Ryosuke; Rasio, Frederic; Takeda, Genya

    2010-09-01

    The long-term habitability of Earth-like planets requires low orbital eccentricities. A secular perturbation from a distant stellar companion is a very important mechanism in exciting planetary eccentricities, as many of the extrasolar planetary systems are associated with stellar companions. Although the orbital evolution of an Earth-like planet in a stellar binary system is well understood, the effect of a binary perturbation on a more realistic system containing additional gas-giant planets has been very little studied. Here, we provide analytic criteria confirmed by a large ensemble of numerical integrations that identify the initial orbital parameters leading to eccentric orbits. We show that an extrasolar earth is likely to experience a broad range of orbital evolution dictated by the location of a gas-giant planet, which necessitates more focused studies on the effect of eccentricity on the potential for life.

  15. Secreted cerberus1 as a marker for quantification of definitive endoderm differentiation of the pluripotent stem cells.

    Directory of Open Access Journals (Sweden)

    Hidefumi Iwashita

    Full Text Available To date, CXCR4 and E-cadherin double-positive cells detected by flow cytometry have been used to identify the differentiation of embryonic stem (ES cells or induced pluripotent stem (iPS cells into definitive endoderm (DE lineages. Quantification of DE differentiation from ES/iPS cells by using flow cytometry is a multi-step procedure including dissociation of the cells, antibody reaction, and flow cytometry analysis. To establish a quick assay method for quantification of ES/iPS cell differentiation into the DE without dissociating the cells, we examined whether secreted Cerberus1 (Cer1 protein could be used as a marker. Cer1 is a secreted protein expressed first in the anterior visceral endoderm and then in the DE. The amount of Cer1 secreted correlated with the proportion of CXCR4+/E-Cadherin+ cells that differentiated from mouse ES cells. In addition, we found that human iPS cell-derived DE also expressed the secreted CER1 and that the expression level correlated with the proportion of SOX17+/FOXA2+ cells present. Taken together, these results show that Cer1 (or CER1 serves as a good marker for quantification of DE differentiation of mouse and human ES/iPS cells.

  16. Three-Dimensional Culture of Human Embryonic Stem Cell Derived Hepatic Endoderm and Its Role in Bioartificial Liver Construction

    Directory of Open Access Journals (Sweden)

    Ruchi Sharma

    2010-01-01

    Full Text Available The liver carries out a range of functions essential for bodily homeostasis. The impairment of liver functions has serious implications and is responsible for high rates of patient morbidity and mortality. Presently, liver transplantation remains the only effective treatment, but donor availability is a major limitation. Therefore, artificial and bioartificial liver devices have been developed to bridge patients to liver transplantation. Existing support devices improve hepatic encephalopathy to a certain extent; however their usage is associated with side effects. The major hindrance in the development of bioartificial liver devices and cellular therapies is the limited availability of human hepatocytes. Moreover, primary hepatocytes are difficult to maintain and lose hepatic identity and function over time even with sophisticated tissue culture media. To overcome this limitation, renewable cell sources are being explored. Human embryonic stem cells are one such cellular resource and have been shown to generate a reliable and reproducible supply of human hepatic endoderm. Therefore, the use of human embryonic stem cell-derived hepatic endoderm in combination with tissue engineering has the potential to pave the way for the development of novel bioartificial liver devices and predictive drug toxicity assays.

  17. Primitive polynomials selection method for pseudo-random number generator

    Science.gov (United States)

    Anikin, I. V.; Alnajjar, Kh

    2018-01-01

    In this paper we suggested the method for primitive polynomials selection of special type. This kind of polynomials can be efficiently used as a characteristic polynomials for linear feedback shift registers in pseudo-random number generators. The proposed method consists of two basic steps: finding minimum-cost irreducible polynomials of the desired degree and applying primitivity tests to get the primitive ones. Finally two primitive polynomials, which was found by the proposed method, used in pseudorandom number generator based on fuzzy logic (FRNG) which had been suggested before by the authors. The sequences generated by new version of FRNG have low correlation magnitude, high linear complexity, less power consumption, is more balanced and have better statistical properties.

  18. Motion Primitives and Probabilistic Edit Distance for Action Recognition

    DEFF Research Database (Denmark)

    Fihl, Preben; Holte, Michael Boelstoft; Moeslund, Thomas B.

    2009-01-01

    the actions as a sequence of temporal isolated instances, denoted primitives. These primitives are each defined by four features extracted from motion images. The primitives are recognized in each frame based on a trained classifier resulting in a sequence of primitives. From this sequence we recognize......The number of potential applications has made automatic recognition of human actions a very active research area. Different approaches have been followed based on trajectories through some state space. In this paper we also model an action as a trajectory through a state space, but we represent...... different temporal actions using a probabilistic Edit Distance method. The method is tested on different actions with and without noise and the results show recognition rates of 88.7% and 85.5%, respectively....

  19. Inconsistent formation and nonfunction of insulin-positive cells from pancreatic endoderm derived from human embryonic stem cells in athymic nude rats

    OpenAIRE

    Matveyenko, Aleksey V.; Georgia, Senta; Bhushan, Anil; Butler, Peter C.

    2010-01-01

    Embryonic stem cell therapy has been proposed as a therapeutic strategy to restore β-cell mass and function in T1DM. Recently, a group from Novocell (now ViaCyte) reported successful development of glucose-responsive islet-like structures after implantation of pancreatic endoderm (PE) derived from human embryonic stem cells (hESC) into immune-deficient mice. Our objective was to determine whether implantation of hESC-derived pancreatic endoderm from Novocell into athymic nude rats results in ...

  20. Primitive myxoid mesenchymal tumor of infancy in a preterm infant.

    Science.gov (United States)

    Lam, Joseph; Lara-Corrales, Irene; Cammisuli, Salvatore; Somers, Gino R; Pope, Elena

    2010-01-01

    Primitive myxoid mesenchymal tumor of infancy is a recently recognized entity that has been added to the differential diagnosis of myxoid tumors of the soft tissue. Few cases have been reported of this entity in the literature, but none presenting in a preterm infant. We present the case and clinical course of a preterm boy with a primitive myxoid mesenchymal tumor of infancy that occurred following excision of a congenital juvenile xanthogranuloma. © 2010 Wiley Periodicals, Inc.

  1. Peripheral Primitive Neuroectodermal Tumor of the Stomach: A Case Report

    International Nuclear Information System (INIS)

    Park, Woon Ju; Cho, June Sik; Shin, Kyung Sook; Jeong, Hyung Yong; Noh; Seung Moo; Song, Kyu Sang

    2010-01-01

    Peripheral primitive neuroectodermal tumors (peripheral PNETs) are very rare and highly aggressive soft tissue malignancies originating from the neural crest. To the best of our knowledge, only a few cases of peripheral PNETs of the stomach have been reported in the literature. We report a case of large peripheral primitive neuroectodermal tumor of the stomach with MDCT findings in a 22-year-old man presenting epigastric pain and vomiting

  2. Cometary dust: the diversity of primitive refractory grains.

    Science.gov (United States)

    Wooden, D H; Ishii, H A; Zolensky, M E

    2017-07-13

    Comet dust is primitive and shows significant diversity. Our knowledge of the properties of primitive cometary particles has expanded significantly through microscale investigations of cosmic dust samples (anhydrous interplanetary dust particles (IDPs), chondritic porous (CP) IDPs and UltraCarbonaceous Antarctic micrometeorites, Stardust and Rosetta ), as well as through remote sensing ( Spitzer IR spectroscopy). Comet dust are aggregate particles of materials unequilibrated at submicrometre scales. We discuss the properties and processes experienced by primitive matter in comets. Primitive particles exhibit a diverse range of: structure and typology; distribution of constituents; concentration and form of carbonaceous and refractory organic matter; Mg- and Fe-contents of the silicate minerals; sulfides; existence/abundance of type II chondrule fragments; high-temperature calcium-aluminium inclusions and ameboid-olivine aggregates; and rarely occurring Mg-carbonates and magnetite, whose explanation requires aqueous alteration on parent bodies. The properties of refractory materials imply there were disc processes that resulted in different comets having particular selections of primitive materials. The diversity of primitive particles has implications for the diversity of materials in the protoplanetary disc present at the time and in the region where the comets formed.This article is part of the themed issue 'Cometary science after Rosetta'. © 2017 The Authors.

  3. Treatment of human embryonic stem cells with different combinations of priming and inducing factors toward definitive endoderm.

    Science.gov (United States)

    Tahamtani, Yasser; Azarnia, Mahnaz; Farrokhi, Ali; Sharifi-Zarchi, Ali; Aghdami, Nasser; Baharvand, Hossein

    2013-05-01

    Despite the enormous progress in studying definitive endoderm (DE) differentiation from human embryonic stem cells (hESCs), none of the reported protocols have produced a universal, cost-effective, and competent DE with the capability to further differentiate into endodermal derivatives. In this study, by using a 2-step differentiation strategy, we have treated hESCs for 1 day with "priming" small molecules (SM), [stauprimide, NSC-308848, rapamycin (Rapa), and/or CHIR] and for the next 3 days with "inducing" SM (LY294002, cymarin, IDE1, and/or IDE2) in conjunction with activin A. In the positive control group, we treated hESCs with Wnt3a (25 ng/mL) for 1 day and activin A (100 ng/mL; W/A100-A100) for the next 3 days. Gene expression analysis showed that treatment of hESCs with 100 nM Rapa and 50 ng/mL activin A (Rapa-A50) out of 25 combinations of factors gave rise to higher expressions of 2 DE-specific genes, SOX17 and FOXA2. Similar results were obtained after treating 2 other hESC lines with this regimen. To investigate the competency of Rapa-A50-induced DE for further differentiation into endodermal derivatives, these cells and W/A100-A100-induced DE cells (positive control) were further differentiated into pancreatic progenitors (PP), then into pancreatic endocrine (PE) cells using 5 previously described differentiation protocols. Gene analysis of differentiated cells showed that the established protocols were insufficient to enable universal differentiation into PE, whereas Rapa-A50-induced DE cells were more competent for PP differentiation in a protocol-dependent manner. Additionally, Rapa-A50-induced DE had the capability to differentiate into hepatocyte-like cells (HLCs) as efficiently as W/A100-A100-induced DE. These data have indicated that hESCs primed with Rapa, and induced by a lower concentration of activin A, could lead to DE that had the capability to further differentiate into HLCs and PP cells, but not PE cells. Thus, current protocols

  4. The Neural Basis of Social Influence in a Dictator Decision

    Directory of Open Access Journals (Sweden)

    Zhenyu Wei

    2017-12-01

    Full Text Available Humans tend to reduce inequitable distributions. Previous neuroimaging studies have shown that inequitable decisions are related to brain regions that associated with negative emotion and signaling conflict. In the highly complex human social environment, our opinions and behaviors can be affected by social information. In current study, we used a modified dictator game to investigate the effect of social influence on making an equitable decision. We found that the choices of participants in present task was influenced by the choices of peers. However, participants’ decisions were influenced by equitable rather than inequitable group choices. fMRI results showed that brain regions that related to norm violation and social conflict were related to the inequitable social influence. The neural responses in the dorsomedial prefrontal cortex, rostral cingulate zone, and insula predicted subsequent conforming behavior in individuals. Additionally, psychophysiological interaction analysis revealed that the interconnectivity between the dorsal striatum and insula was elevated in advantageous inequity influence versus no-social influence conditions. We found decreased functional connectivity between the medial prefrontal cortex and insula, supplementary motor area, posterior cingulate gyrus and dorsal anterior cingulate cortex in the disadvantageous inequity influence versus no-social influence conditions. This suggests that a disadvantageous inequity influence may decrease the functional connectivity among brain regions that are related to reward processes. Thus, the neural mechanisms underlying social influence in an equitable decision may be similar to those implicated in social norms and reward processing.

  5. The Neural Basis of Social Influence in a Dictator Decision.

    Science.gov (United States)

    Wei, Zhenyu; Zhao, Zhiying; Zheng, Yong

    2017-01-01

    Humans tend to reduce inequitable distributions. Previous neuroimaging studies have shown that inequitable decisions are related to brain regions that associated with negative emotion and signaling conflict. In the highly complex human social environment, our opinions and behaviors can be affected by social information. In current study, we used a modified dictator game to investigate the effect of social influence on making an equitable decision. We found that the choices of participants in present task was influenced by the choices of peers. However, participants' decisions were influenced by equitable rather than inequitable group choices. fMRI results showed that brain regions that related to norm violation and social conflict were related to the inequitable social influence. The neural responses in the dorsomedial prefrontal cortex, rostral cingulate zone, and insula predicted subsequent conforming behavior in individuals. Additionally, psychophysiological interaction analysis revealed that the interconnectivity between the dorsal striatum and insula was elevated in advantageous inequity influence versus no-social influence conditions. We found decreased functional connectivity between the medial prefrontal cortex and insula, supplementary motor area, posterior cingulate gyrus and dorsal anterior cingulate cortex in the disadvantageous inequity influence versus no-social influence conditions. This suggests that a disadvantageous inequity influence may decrease the functional connectivity among brain regions that are related to reward processes. Thus, the neural mechanisms underlying social influence in an equitable decision may be similar to those implicated in social norms and reward processing.

  6. Family income affects children's altruistic behavior in the dictator game.

    Directory of Open Access Journals (Sweden)

    Yongxiang Chen

    Full Text Available This study aimed to examine how family income and social distance influence young rural Chinese children's altruistic behavior in the dictator game (DG. A total of 469 four-year-old children from eight rural areas in China, including many children left behind by parents who had migrated to urban areas for work, played the DG. Stickers comprised the resource, while recipients in the game were assumed to be either their friends or strangers, with the social distance (i.e., strangers compared to friends as a between-subjects variable. Children donated significantly more stickers to their friends than to strangers. Moreover, children from lower income families donated more stickers than children from higher income families. However, no gender and parental migrant status differences in children's prosocial behaviors were evident in this sample. Findings of this study suggest that children's altruistic behaviours to peers are influenced by family characteristics since preschool age. The probable influence of local socialization practices on development and the possible adaptive significance were discussed.

  7. Regulatory hotspots in the malaria parasite genome dictate transcriptional variation.

    Directory of Open Access Journals (Sweden)

    Joseph M Gonzales

    2008-09-01

    Full Text Available The determinants of transcriptional regulation in malaria parasites remain elusive. The presence of a well-characterized gene expression cascade shared by different Plasmodium falciparum strains could imply that transcriptional regulation and its natural variation do not contribute significantly to the evolution of parasite drug resistance. To clarify the role of transcriptional variation as a source of stain-specific diversity in the most deadly malaria species and to find genetic loci that dictate variations in gene expression, we examined genome-wide expression level polymorphisms (ELPs in a genetic cross between phenotypically distinct parasite clones. Significant variation in gene expression is observed through direct co-hybridizations of RNA from different P. falciparum clones. Nearly 18% of genes were regulated by a significant expression quantitative trait locus. The genetic determinants of most of these ELPs resided in hotspots that are physically distant from their targets. The most prominent regulatory locus, influencing 269 transcripts, coincided with a Chromosome 5 amplification event carrying the drug resistance gene, pfmdr1, and 13 other genes. Drug selection pressure in the Dd2 parental clone lineage led not only to a copy number change in the pfmdr1 gene but also to an increased copy number of putative neighboring regulatory factors that, in turn, broadly influence the transcriptional network. Previously unrecognized transcriptional variation, controlled by polymorphic regulatory genes and possibly master regulators within large copy number variants, contributes to sweeping phenotypic evolution in drug-resistant malaria parasites.

  8. Hypothesis: solid tumours behave as systemic metabolic dictators.

    Science.gov (United States)

    Lee, Yang-Ming; Chang, Wei-Chun; Ma, Wen-Lung

    2016-06-01

    Current knowledge regarding mechanisms of carcinogenesis in human beings centres around the accumulation of genetic instability, amplified cellular signalling, disturbed cellular energy metabolism and microenvironmental regulation governed by complicated cell-cell interactions. In this article, we provide an alternative view of cancer biology. We propose that cancer behaves as a systemic dictator that interacts with tissues throughout the body to control their metabolism and eventually homeostasis. The mechanism of development of this endocrine organ-like tumour (EOLT) tissue might be the driving force for cancer progression. Here, we review the literature that led to the development of this hypothesis. The EOLT phenotype can be defined as a tumour that alters systemic homeostasis. The literature indicates that the EOLT phenotype is present throughout cancer progression. The feedback mechanism that governs the interaction between tumours and various organs is unknown. We believe that investigating the mechanism of EOLT development may advance the current knowledge of regulation within the tumour macroenvironment and consequently lead to new diagnostic methods and therapy. © 2016 The Authors. Journal of Cellular and Molecular Medicine published by John Wiley & Sons Ltd and Foundation for Cellular and Molecular Medicine.

  9. A peptide extension dictates IgM assembly.

    Science.gov (United States)

    Pasalic, Dzana; Weber, Benedikt; Giannone, Chiara; Anelli, Tiziana; Müller, Roger; Fagioli, Claudio; Felkl, Manuel; John, Christine; Mossuto, Maria Francesca; Becker, Christian F W; Sitia, Roberto; Buchner, Johannes

    2017-10-10

    Professional secretory cells can produce large amounts of high-quality complex molecules, including IgM antibodies. Owing to their multivalency, polymeric IgM antibodies provide an efficient first-line of defense against pathogens. To decipher the mechanisms of IgM assembly, we investigated its biosynthesis in living cells and faithfully reconstituted the underlying processes in vitro. We find that a conserved peptide extension at the C-terminal end of the IgM heavy (Ig-μ) chains, termed the tailpiece, is necessary and sufficient to establish the correct geometry. Alanine scanning revealed that hydrophobic amino acids in the first half of the tailpiece contain essential information for generating the correct topology. Assembly is triggered by the formation of a disulfide bond linking two tailpieces. This induces conformational changes in the tailpiece and the adjacent domain, which drive further polymerization. Thus, the biogenesis of large and topologically challenging IgM complexes is dictated by a local conformational switch in a peptide extension.

  10. Comet Dust: The Diversity of Primitive Particles and Implications

    Science.gov (United States)

    John Bradley; Zolensky, Michael E.

    2016-01-01

    Comet dust is primitive and shows significant diversity. Our knowledge of the properties of primitive particles has expanded significantly through microscale investigations of cosmic dust samples (IDPs and AMMs) and of comet dust samples (Stardust and Rosetta's COSIMA), as well as through remote sensing (spectroscopy and imaging) via Spitzer and via spacecraft encounters with 103P/Hartley 2 and 67P/Churyumov-Gerasimenko. Microscale investigations show that comet dust and cosmic dust are particles of unequilibrated materials, including aggregates of materials unequilibrated at submicron scales. We call unequilibrated materials "primitive" and we deduce they were incorporated into ice-­-rich (H2O-, CO2-, and CO-ice) parent bodies that remained cold, i.e., into comets, because of the lack of aqueous or thermal alteration since particle aggregation; yet some Stardust olivines suggest mild thermal metamorphism. Primitive particles exhibit a diverse range of: structure and typology; size and size distribution of constituents; concentration and form of carbonaceous and organic matter; D-, N-, and O- isotopic enhancements over solar; Mg-, Fe-contentsof thesilicate minerals; the compositions and concentrations of sulfides, and of less abundant mineral species such as chondrules, CAIs and carbonates. The unifomity within a group of samples points to: aerodynamic sorting of particles and/or particle constituents; the inclusion of a limited range of oxygen fugacities; the inclusion or exclusion of chondrules; a selection of organics. The properites of primitive particles imply there were disk processes that resulted in different comets having particular selections of primitive materials. The diversity of primitive particles has implications for the diversity of materials in the protoplanetary disk present at the time and in the region where the comets formed.

  11. Comet Dust: The Diversity of "Primitive" Particles and Implications

    Science.gov (United States)

    Wooden, Diane H.; Ishii, Hope A.; Bradley, John P.; Zolensky, Michael E.

    2016-01-01

    Comet dust is primitive and shows significant diversity. Our knowledge of the properties of primitive particles has expanded significantly through microscale investigations of cosmic dust samples ( IDP's(Interplanetary Dust Particles) and AMM's (Antarctic Micrometeorites)) and of comet dust samples (Stardust and Rosetta's COSIMA), as well as through remote sensing (spectroscopy and imaging) via Spitzer and via spacecraft encounters with 103P/Hartley 2 and 67P/Churyumov-Gerasimenko. Microscale investigations show that comet dust and cosmic dust are particles of unequilibrated materials, including aggregates of materials unequilibrated at submicron scales. We call unequilibrated materials "primitive" and we deduce they were incorporated into ice-rich (H2O-, CO2-, and CO-ice) parent bodies that remained cold, i.e., into comets, because of the lack of aqueous or thermal alteration since particle aggregation; yet some Stardust olivines suggest mild thermal metamorphism. Primitive particles exhibit a diverse range of: structure and typology; size and size distribution of constituents; concentration and form of carbonaceous and organic matter; D-, N-, and O- isotopic enhancements over solar; Mg-, Fe-contents of the silicate minerals; the compositions and concentrations of sulfides, and of less abundant mineral species such as chondrules, CAIs and carbonates. The uniformity within a group of samples points to: aerodynamic sorting of particles and/or particle constituents; the inclusion of a limited range of oxygen fugacities; the inclusion or exclusion of chondrules; a selection of organics. The properties of primitive particles imply there were disk processes that resulted in different comets having particular selections of primitive materials. The diversity of primitive particles has implications for the diversity of materials in the protoplanetary disk present at the time and in the region where the comets formed.

  12. Eutectic propeties of primitive Earth's magma ocean

    Science.gov (United States)

    Lo Nigro, G.; Andrault, D.; Bolfan-Casanova, N.; Perillat, J.-P.

    2009-04-01

    It is widely accepted that the early Earth was partially molten (if not completely) due to the high energy dissipated by terrestrial accretion [1]. After core formation, subsequent cooling of the magma ocean has led to fractional crystallization of the primitive mantle. The residual liquid corresponds to what is now called the fertile mantle or pyrolite. Melting relations of silicates have been extensively investigated using the multi-anvil press, for pressures between 3 and 25 GPa [2,3]. Using the quench technique, it has been shown that the pressure affects significantly the solidus and liquidus curves, and most probably the composition of the eutectic liquid. At higher pressures, up to 65 GPa, melting studies were performed on pyrolite starting material using the laser-heated diamond anvil cell (LH-DAC) technique [4]. However, the quench technique is not ideal to define melting criteria, and furthermore these studies were limited in pressure range of investigation. Finally, the use of pyrolite may not be relevant to study the melting eutectic temperature. At the core-mantle boundary conditions, melting temperature is documented by a single data point on (Mg,Fe)2SiO4 olivine, provided by shock wave experiments at around 130-140 GPa [5]. These previous results present large uncertainties of ~1000 K. The aim of this study is to determine the eutectic melting temperature in the chemically simplified system composed of the two major lower mantle phases, the MgSiO3 perovskite and MgO periclase. We investigated melting in-situ using the laser-heated diamond anvil cell coupled with angle dispersive X-ray diffraction at the ID27 beamline of the ESRF [6]. Melting relations were investigated in an extended P-T range comparable to those found in the Earth's lower mantle, i.e. from 25 to 120 GPa and up to more than 5000 K. Melting was evidenced from (a) disappearance of one of the two phases in the diffraction pattern, (b) drastic changes of the diffraction image itself, and

  13. The first trimester human placenta is a site for terminal maturation of primitive erythroid cells

    OpenAIRE

    Van Handel, Ben; Prashad, Sacha L.; Hassanzadeh-Kiabi, Nargess; Huang, Andy; Magnusson, Mattias; Atanassova, Boriana; Chen, Angela; Hamalainen, Eija I.; Mikkola, Hanna K. A.

    2010-01-01

    Embryonic hematopoiesis starts via the generation of primitive red blood cells (RBCs) that satisfy the embryo's immediate oxygen needs. Although primitive RBCs were thought to retain their nuclei, recent studies have shown that primitive RBCs in mice enucleate in the fetal liver. It has been unknown whether human primitive RBCs enucleate, and what hematopoietic site might support this process. Our data indicate that the terminal maturation and enucleation of human primitive RBCs occurs in fir...

  14. Distinct gene expression signatures in human embryonic stem cells differentiated towards definitive endoderm at single-cell level

    DEFF Research Database (Denmark)

    Norrman, Karin; Strömbeck, Anna; Semb, Henrik

    2013-01-01

    for the three activin A based protocols applied. Our data provide novel insights in DE gene expression at the cellular level of in vitro differentiated human embryonic stem cells, and illustrate the power of using single-cell gene expression profiling to study differentiation heterogeneity and to characterize...... of anterior definitive endoderm (DE). Here, we differentiated human embryonic stem cells towards DE using three different activin A based treatments. Differentiation efficiencies were evaluated by gene expression profiling over time at cell population level. A panel of key markers was used to study DE...... formation. Final DE differentiation was also analyzed with immunocytochemistry and single-cell gene expression profiling. We found that cells treated with activin A in combination with sodium butyrate and B27 serum-free supplement medium generated the most mature DE cells. Cell population studies were...

  15. Nuclear movement regulated by non-Smad Nodal signaling via JNK is associated with Smad signaling during zebrafish endoderm specification.

    Science.gov (United States)

    Hozumi, Shunya; Aoki, Shun; Kikuchi, Yutaka

    2017-11-01

    Asymmetric nuclear positioning is observed during animal development, but its regulation and significance in cell differentiation remain poorly understood. Using zebrafish blastulae, we provide evidence that nuclear movement towards the yolk syncytial layer, which comprises extraembryonic tissue, occurs in the first cells fated to differentiate into the endoderm. Nodal signaling is essential for nuclear movement, whereas nuclear envelope proteins are involved in movement through microtubule formation. Positioning of the microtubule-organizing center, which is proposed to be crucial for nuclear movement, is regulated by Nodal signaling and nuclear envelope proteins. The non-Smad JNK signaling pathway, which is downstream of Nodal signaling, regulates nuclear movement independently of the Smad pathway, and this nuclear movement is associated with Smad signal transduction toward the nucleus. Our study provides insight into the function of nuclear movement in Smad signaling toward the nucleus, and could be applied to the control of TGFβ signaling. © 2017. Published by The Company of Biologists Ltd.

  16. Globfit: Consistently fitting primitives by discovering global relations

    KAUST Repository

    Li, Yangyan; Wu, Xiaokun; Chrysathou, Yiorgos; Sharf, Andrei Sharf; Cohen-Or, Daniel; Mitra, Niloy J.

    2011-01-01

    Given a noisy and incomplete point set, we introduce a method that simultaneously recovers a set of locally fitted primitives along with their global mutual relations. We operate under the assumption that the data corresponds to a man-made engineering object consisting of basic primitives, possibly repeated and globally aligned under common relations. We introduce an algorithm to directly couple the local and global aspects of the problem. The local fit of the model is determined by how well the inferred model agrees to the observed data, while the global relations are iteratively learned and enforced through a constrained optimization. Starting with a set of initial RANSAC based locally fitted primitives, relations across the primitives such as orientation, placement, and equality are progressively learned and conformed to. In each stage, a set of feasible relations are extracted among the candidate relations, and then aligned to, while best fitting to the input data. The global coupling corrects the primitives obtained in the local RANSAC stage, and brings them to precise global alignment. We test the robustness of our algorithm on a range of synthesized and scanned data, with varying amounts of noise, outliers, and non-uniform sampling, and validate the results against ground truth, where available. © 2011 ACM.

  17. Globfit: Consistently fitting primitives by discovering global relations

    KAUST Repository

    Li, Yangyan

    2011-07-01

    Given a noisy and incomplete point set, we introduce a method that simultaneously recovers a set of locally fitted primitives along with their global mutual relations. We operate under the assumption that the data corresponds to a man-made engineering object consisting of basic primitives, possibly repeated and globally aligned under common relations. We introduce an algorithm to directly couple the local and global aspects of the problem. The local fit of the model is determined by how well the inferred model agrees to the observed data, while the global relations are iteratively learned and enforced through a constrained optimization. Starting with a set of initial RANSAC based locally fitted primitives, relations across the primitives such as orientation, placement, and equality are progressively learned and conformed to. In each stage, a set of feasible relations are extracted among the candidate relations, and then aligned to, while best fitting to the input data. The global coupling corrects the primitives obtained in the local RANSAC stage, and brings them to precise global alignment. We test the robustness of our algorithm on a range of synthesized and scanned data, with varying amounts of noise, outliers, and non-uniform sampling, and validate the results against ground truth, where available. © 2011 ACM.

  18. Consistency and Stability of Italian Children's Spelling in Dictation versus Composition Assessments

    Science.gov (United States)

    Bigozzi, Lucia; Tarchi, Christian; Pinto, Giuliana

    2017-01-01

    The purpose of this study was to investigate consistency in spelling skills across 2 different tasks of written production (dictation vs. composition) and stability of performance across 4 different grades. We assessed 2nd, 3rd, 4th, and 5th graders' spelling performance through 4 tasks: 2 dictation tasks (passage and sentences) and 2 composition…

  19. Nucleation and condensation in the primitive solar nebula

    International Nuclear Information System (INIS)

    Cameron, A.G.W.; Fegley, M.B.

    1982-01-01

    It is pointed out that the primitive solar nebula may be modeled using the frictionally induced transport theory of Lynden-Bell and Pringle (1974) if the principal frictional mechanism within the nebula is turbulent viscosity. The present investigation is concerned with the construction of a model of a section of the primitive solar nebula as a basis for the study of nucleation and condensation processes within this section. The construction involves a relatively simple application of the Lynden-Bell and Pringle theory subject to steady mass flow conditions. The calculations which are conducted in connection with the investigation indicate that by the time the gas in the primitive solar nebula has become sufficiently supercooled to nucleate condensation centers, several different compounds, including the magnesium silicates forsterite and enstatite (MgSiO 3 ), will probably be able to condense on the growing condensation center

  20. Primitive neuroectodermal tumor of the cervix: a case report

    Directory of Open Access Journals (Sweden)

    Boroujeni Parisa

    2011-09-01

    Full Text Available Abstract Introduction Peripheral primitive neuroectodermal tumor of the cervix uteri is extremely rare. Between 1987 and 2010, there were only nine cases reported in the English literature, with considerably different management policies. Case presentation A 45-year-old Iranian woman presented to our facility with a primitive neuroectodermal tumor of the cervix uteri. Her clinical stage IB2 tumor was treated successfully with chemotherapy. Our patient underwent radical hysterectomy. There was no trace of the tumor after four years of follow-up. Conclusions According to current knowledge, primitive neuroectodermal tumors belong to the Ewing's sarcoma family, and the improvement of treatment outcome in our patient was due to dose-intensive neoadjuvant chemotherapy, surgery and consolidation chemotherapy in accordance with the protocol for bony Ewing's sarcoma.

  1. Context of culture: Critique of the primitive mind

    Directory of Open Access Journals (Sweden)

    Božilović Nikola

    2010-01-01

    Full Text Available The author of this paper has the intention to reach the new meaning and sense of the primitive mentality by analyzing it in early social communities. He also wants to point out the possible reflections of the spirit and consciousness of our ancestors on us, here and now. The first part of the paper is dedicated to a critical deliberation on anthropological conflicts which have arisen concerning the reasoning power of the so-called primitives. The crucial question lies in the following: Is the difference between the “primitive” and the “civilized” mentality fundamental or is it possible only to a certain degree. The author takes the notion of primitive mentality through time and points to the medieval understandings, which are occupied by teratological themes, then to the renaissance comprehension, which relies on the first experiential observations, and, finally, to the enlightenment ideas of exotic peoples out of which the myth of “the good savage” is born. The nineteenth and twentieth centuries introduce the notions of “people’s character” and “national spirit”. The opinions are polarized, on the one hand of ethnocentrism, carried by the prejudice of people and ethnic groups and, on the other hand, of cultural relativism, based on the understanding and appreciation of cultural differences. In the end, the author also recognizes the modern primitive man, one who is not ready to deal with the challenges of his age. The modern primitive recalls the spirits of the past, the surviving and anachronic models of behavior, unaware of the fact that these are the same models that he has ascribed to “savages”. However, while such thinking and acting was justified by the cultural level at which our ancestors had lived, the mental frame of the contemporary primitives is significantly in contrast with the high level of civilization development.

  2. Alloy Microstructure Dictates Corrosion Modes in THA Modular Junctions.

    Science.gov (United States)

    Pourzal, Robin; Hall, Deborah J; Ehrich, Jonas; McCarthy, Stephanie M; Mathew, Mathew T; Jacobs, Joshua J; Urban, Robert M

    2017-12-01

    Adverse local tissue reactions (ALTRs) triggered by corrosion products from modular taper junctions are a known cause of premature THA failure. CoCrMo devices are of particular concern because cobalt ions and chromium-orthophosphates were shown to be linked to ALTRs, even in metal-on-polyethylene THAs. The most common categories of CoCrMo alloy are cast and wrought alloy, which exhibit fundamental microstructural differences in terms of grain size and hard phases. The impact of implant alloy microstructure on the occurring modes of corrosion and subsequent metal ion release is not well understood. The purpose of this study was to determine whether (1) the microstructure of cast CoCrMo alloy varies broadly between manufacturers and can dictate specific corrosion modes; and whether (2) the microstructure of wrought CoCrMo alloy is more consistent between manufacturers and has low implications on the alloy's corrosion behavior. The alloy microstructure of four femoral-stem and three femoral-head designs from four manufacturers was metallographically and electrochemically characterized. Three stem designs were made from cast alloy; all three head designs and one stem design were made from wrought alloy. Alloy samples were sectioned from retrieved components and then polished and etched to visualize grain structure and hard phases such as carbides (eg, M 23 C 6 ) or intermetallic phases (eg, σ phase). Potentiodynamic polarization (PDP) tests were conducted to determine the corrosion potential (E corr ), corrosion current density (I corr ), and pitting potential (E pit ) for each alloy. Four devices were tested within each group, and each measurement was repeated three times to ensure repeatable results. Differences in PDP metrics between manufacturers and between alloys with different hard phase contents were compared using one-way analysis of variance and independent-sample t-tests. Microstructural features such as twin boundaries and slip bands as well as corrosion

  3. The Syntax of Time and Space Primitives in French.

    Science.gov (United States)

    Peeters, Bert

    1997-01-01

    Explores the combinatorial possibilities of semantic primitives of time and space in French, as defined in the theory of Natural Semantic Metalanguage. Highlights the need for new ways to express the allolexical relationship in some combinations, particularly those expressing "when/time." (Author/MSE)

  4. Primitive neuroectodermal tumour of the kidney: radiologic-pathological correlations.

    Science.gov (United States)

    Chea, Y W; Agrawal, Rashi; Poh, Angeline C C

    2008-06-01

    A primitive neuroectodermal tumour of the kidney is a rare malignancy. We report the computed tomographic features and the histopathological correlation of such a tumour occurring in a middle-aged man. Although the radiological appearance has significant overlap with other renal tumours, this tumour should be included in the differential diagnosis of a large renal mass in younger patients.

  5. Letters of Gold: Enabling Primitive Accumulation through Neoliberal Conservation

    NARCIS (Netherlands)

    B.E. Büscher (Bram)

    2009-01-01

    textabstractAbstract: In Capital I, Marx wrote that the history of the separation of the producers from the means of production “is written in the annals of mankind in letters of blood and fire” (Marx, 1976: 875). This ‘so-called primitive accumulation’, or ‘accumulation by dispossession’ in David

  6. Addressing Nature Deficit Disorder through Primitive Camping Experiences

    Science.gov (United States)

    Allen, Kevin; Varner, Keegan; Sallee, Jeff

    2011-01-01

    Today's youth suffer from Nature Deficit Disorder, a condition that has been connected to ADHD, shortage of creativity, and general lack of knowledge about the outdoors. A team of educators and specialists are addressing this issue with primitive camping. County educators were trained using experiential learning and train-the-trainer techniques.…

  7. Understanding and determining the variability of the primitive stress environment.

    CSIR Research Space (South Africa)

    Sellers, EJ

    2002-10-01

    Full Text Available The primitive stress state is an important input into the design of underground excavations. However, it is well known that the stress state varies considerably from place to place. The aim of this project was to determine the main causes...

  8. COMPARATIVE STUDY OF RTOS AND PRIMITIVE INTERRUPT IN EMBEDDED SYSTEM

    Directory of Open Access Journals (Sweden)

    Dwi Purnomo

    2015-03-01

    Full Text Available Multitasking is one of the most challenging issues in the automation industry which is highly depended on the embedded system. There are two methods to perform multitasking in embedded system: RTOS and primitive interrupt. The main purpose of this research is to compare the performance of R¬TOS with primitive method while concurrently undertaking multiple tasks. The system, which is able to perform various tasks, has been built to evaluate the performance of both methods. There are four tasks introduced in the system: servo task, sensor task, LED task, and LCD task. The performance of each method is indicated by the success rate of the sensor task detection. Sensor task detection will be compared with the true value which is calculated and measured manually during observation time. Observation time was varied after several iterations and the data of the iteration are recorded for both RTOS and primitive interrupt methods. The results of the conducted experiments have shown that, RTOS is more accurate than interrupt method. However, the data variance of the primitive interrupt method is narrower than RTOS. Therefore, to choose a better method, an optimization is needed to be done and each product has its own standard.

  9. A Test of Durkheim's Theory of Suicide in Primitive Societies.

    Science.gov (United States)

    Lester, David

    1992-01-01

    Classified primitive societies as high, moderate, or low on independent measures of social integration and social regulation to test Durkheim's theory of suicide. Estimated frequency of suicide did not differ between those societies predicted to have high, moderate, and low suicide rates. Durkheim's theory was not confirmed. (Author/NB)

  10. Primary extraskeletal Ewing's sarcoma/primitive neuroectodermal tumor of breast

    Directory of Open Access Journals (Sweden)

    Smita Srivastava

    2016-01-01

    Full Text Available Extraskeletal Ewing's sarcoma (EES is a rare soft tissue tumor that is morphologically indistinguishable from skeletal ES. We report a case of a 25-year-old female with recurrent EES/primitive neuroectodermal tumor of right breast with imaging findings on mammogram, ultrasound, magnetic resonance imaging breast, and positron emission tomography–computed tomography.

  11. Cancer of unknown primitive metastatic. About two clinical cases

    International Nuclear Information System (INIS)

    Cawen, L; Cordoba, A.

    2010-01-01

    This work is about the two clinical cases about the unknown primitive metastatic cancer. The main techniques used for the diagnosis, treatment and monitoring of different s carcinomas are: Electronic microscope, molecular biology and genetics, especially histopathological study, topographic survey, ultrasound, radiography, chemotherapy, radiotherapy

  12. Improving the Dictation in Attention Deficit Hyperactivity Disorder by Using Computer Based Interventions: A Clinical Trial

    Directory of Open Access Journals (Sweden)

    Mahdi Tehranidoost

    2006-07-01

    Full Text Available Objective: The aim of the current study was to assess the impact of computer games and computer-assisted type instruction on dictation scores of elementary school children with attention deficit – hyperactivity disorder (ADHD. Method: In this single-blind clinical trial, 37 elementary school children with ADHD, selected by convenience sampling and divided into group I (n=17 and group II (n=20, underwent eight one-hour sessions (3 sessions per week of intervention by computer games versus computer-assisted type instruction, respectively. 12 school dictation scores were considered: 4 scores preintervention, 4 scores during interventions, and 4 scores post-intervention. Dictation test was taken during each session. Data was analyzed using repeated measure ANOVA. Results: Two groups were matched for age, gender, school grade, medication, IQ, parent’s and teacher’s Conners’ scale scores, having computer at home, history of working with computer, and mean dictation scores. There was no significant difference in dictation scores before and after interventions and also between the study groups. The improvement in school dictation scores had no significant correlation with age, gender, Ritalin use, owning a computer at home and past history of computer work, baseline dictation scores, Ritalin dose, educational status, IQ, and the total score of parent’s and teacher’s Conners’ rating scale. Conclusion: Absence of significant improvement in dictation scores in study groups may be due to the confounding effect of other variables with known impact on dictation scores. Further studies in this field should also assess the change of attention and memory.

  13. Human embryonic stem cell-derived pancreatic endoderm alleviates diabetic pathology and improves reproductive outcome in C57BL/KsJ-Lep(db/+) gestational diabetes mellitus mice.

    Science.gov (United States)

    Xing, Baoheng; Wang, Lili; Li, Qin; Cao, Yalei; Dong, Xiujuan; Liang, Jun; Wu, Xiaohua

    2015-07-01

    Gestational diabetes mellitus is a condition commonly encountered during mid to late pregnancy with pathologic manifestations including hyperglycemia, hyperinsulinemia, insulin resistance, and fetal maldevelopment. The cause of gestational diabetes mellitus can be attributed to both genetic and environmental factors, hence complicating its diagnosis and treatment. Pancreatic progenitors derived from human embryonic stem cells were shown to be able to effectively treat diabetes in mice. In this study, we have developed a system of treating diabetes using human embryonic stem cell-derived pancreatic endoderm in a mouse model of gestational diabetes mellitus. Human embryonic stem cells were differentiated in vitro into pancreatic endoderm, which were then transplanted into db/+ mice suffering from gestational diabetes mellitus. The transplant greatly improved glucose metabolism and reproductive outcome of the females compared with the control groups. Our findings support the feasibility of using differentiated human embryonic stem cells for treating gestational diabetes mellitus patients. Copyright © 2015 Elsevier Inc. All rights reserved.

  14. Primitive neuroectodermal tumor of the orbit in a 5-year-old girl with microphthalmia

    DEFF Research Database (Denmark)

    Alyahya, Ghassan Ayish Jabur; Heegaard, Steffen; Fledelius, Hans C.

    2000-01-01

    ophthalmology, primitive neuroectodermal tumor (PNET), Ewing's sarcoma, small round-cell tumors, retinoblastoma, medulloepithelioma, microphthalmia, orbitotomy......ophthalmology, primitive neuroectodermal tumor (PNET), Ewing's sarcoma, small round-cell tumors, retinoblastoma, medulloepithelioma, microphthalmia, orbitotomy...

  15. Written object naming, spelling to dictation, and immediate copying: Different tasks, different pathways?

    Science.gov (United States)

    Bonin, Patrick; Méot, Alain; Lagarrigue, Aurélie; Roux, Sébastien

    2015-01-01

    We report an investigation of cross-task comparisons of handwritten latencies in written object naming, spelling to dictation, and immediate copying. In three separate sessions, adults had to write down a list of concrete nouns from their corresponding pictures (written naming), from their spoken (spelling to dictation) and from their visual presentation (immediate copying). Linear mixed models without random slopes were performed on the latencies in order to study and compare within-task fixed effects. By-participants random slopes were then included to investigate individual differences within and across tasks. Overall, the findings suggest that written naming, spelling to dictation, and copying all involve a lexical pathway, but that written naming relies on this pathway more than the other two tasks do. Only spelling to dictation strongly involves a nonlexical pathway. Finally, the analyses performed at the level of participants indicate that, depending on the type of task, the slower participants are more or less influenced by certain psycholinguistic variables.

  16. A feeling of flow: exploring junior scientists' experiences with dictation of scientific articles.

    Science.gov (United States)

    Spanager, Lene; Danielsen, Anne Kjaergaard; Pommergaard, Hans-Christian; Burcharth, Jakob; Rosenberg, Jacob

    2013-08-10

    Science involves publishing results, but many scientists do not master this. We introduced dictation as a method of producing a manuscript draft, participating in writing teams and attending a writing retreat to junior scientists in our department. This study aimed to explore the scientists' experiences with this process. Four focus group interviews were conducted and comprised all participating scientists (n = 14). Each transcript was transcribed verbatim and coded independently by two interviewers. The coding structure was discussed until consensus and from this the emergent themes were identified. Participants were 7 PhD students, 5 scholarship students and 2 clinical research nurses. Three main themes were identified: 'Preparing and then letting go' indicated that dictating worked best when properly prepared. 'The big dictation machine' described benefits of writing teams when junior scientists got feedback on both content and structure of their papers. 'Barriers to and drivers for participation' described flow-like states that participants experienced during the dictation. Motivation and a high level of preparation were pivotal to be able to dictate a full article in one day. The descriptions of flow-like states seemed analogous to the theoretical model of flow which is interesting, as flow is usually deemed a state reserved to skilled experts. Our findings suggest that other academic groups might benefit from using the concept including dictation of manuscripts to encourage participants' confidence in their writing skills.

  17. Indoor objects and outdoor urban scenes recognition by 3D visual primitives

    DEFF Research Database (Denmark)

    Fu, Junsheng; Kämäräinen, Joni-Kristian; Buch, Anders Glent

    2014-01-01

    , we propose an alternative appearance-driven approach which rst extracts 2D primitives justi ed by Marr's primal sketch, which are \\accumulated" over multiple views and the most stable ones are \\promoted" to 3D visual primitives. The 3D promoted primitives represent both structure and appearance...

  18. High water content in primitive continental flood basalts.

    Science.gov (United States)

    Xia, Qun-Ke; Bi, Yao; Li, Pei; Tian, Wei; Wei, Xun; Chen, Han-Lin

    2016-05-04

    As the main constituent of large igneous provinces, the generation of continental flood basalts (CFB) that are characterized by huge eruption volume (>10(5) km(3)) within short time span (primitive CFB in the early Permian Tarim large igneous province (NW China), using the H2O content of ten early-formed clinopyroxene (cpx) crystals that recorded the composition of the primitive Tarim basaltic melts and the partition coefficient of H2O between cpx and basaltic melt. The arc-like H2O content (4.82 ± 1.00 wt.%) provides the first clear evidence that H2O plays an important role in the generation of CFB.

  19. Primitive Path Analysis and Stress Distribution in Highly Strained Macromolecules.

    Science.gov (United States)

    Hsu, Hsiao-Ping; Kremer, Kurt

    2018-01-16

    Polymer material properties are strongly affected by entanglement effects. For long polymer chains and composite materials, they are expected to be at the origin of many technically important phenomena, such as shear thinning or the Mullins effect, which microscopically can be related to topological constraints between chains. Starting from fully equilibrated highly entangled polymer melts, we investigate the effect of isochoric elongation on the entanglement structure and force distribution of such systems. Theoretically, the related viscoelastic response usually is discussed in terms of the tube model. We relate stress relaxation in the linear and nonlinear viscoelastic regimes to a primitive path analysis (PPA) and show that tension forces both along the original paths and along primitive paths, that is, the backbone of the tube, in the stretching direction correspond to each other. Unlike homogeneous relaxation along the chain contour, the PPA reveals a so far not observed long-lived clustering of topological constraints along the chains in the deformed state.

  20. Formalizing the Relationship Between Commitment and Basic Cryptographic Primitives

    Directory of Open Access Journals (Sweden)

    S. Sree Vivek

    2016-11-01

    Full Text Available Signcryption is a cryptographic primitive which offers the functionality of both digital signature and encryption with lower combined computational cost. On the other hand, commitment scheme allows an entity to commit to a value, where the entity reveals the committed value later during a decommit phase. In this paper, we explore the connection between commitment schemes, public key encryption, digital signatures and signcryption. We establish formal relationship between commitment and the other primitives. Our main result is that we show signcryption can be used as a commitment scheme with appropriate security notions. We show that if the underlying signcryption scheme is IND-CCA2 secure, then the hiding property of the commitment scheme is satisfied. Similarly, we show that if the underlying signcryption scheme is unforgeable, then the relaxed biding property of the commitment scheme is satisfied. Moreover, we prove that if the underlying signcryption scheme is NM-CCA2, then the commitment scheme is non-malleable.

  1. Search for Primitive Matter in the Solar System

    Science.gov (United States)

    Libourel, G.; Michel, P.; Delbo, M.; Ganino, C.; Recio-Blanco, A.; de Laverny, P.; Zolensky, M. E.; Krot, A. N.

    2017-01-01

    Recent astronomical observations and theoretical modeling led to a consensus regarding the global scenario of the formation of young stellar objects (YSO) from a cold molecular cloud of interstellar dust (organics and minerals) and gas that, in some cases, leads to the formation of a planetary system. In the case of our Solar System, which has already evolved for approximately 4567 Ma, the quest is to access, through the investigation of planets, moons, cometary and asteroidal bodies, meteorites, micrometeorites, and interplanetary dust particles, the primitive material that contains the key information about the early Solar System processes and its evolution. However, laboratory analyses of extraterrestrial samples, astronomical observations and dynamical models of the Solar System evolution have not brought yet any conclusive evidence on the nature and location of primitive matter in the Solar System, preventing a clear understanding of its early stages.

  2. Morphological Study of Insoluble Organic Matter Residues from Primitive

    Science.gov (United States)

    Changela, H. G.; Stroud, R. M.; Peeters, Z.; Nittler, L. R.; Alexander, C. M. O'D.; DeGregorio, B. T.; Cody, G. D.

    2012-01-01

    Insoluble organic matter (IOM) constitutes a major proportion, 70-99%, of the total organic carbon found in primitive chondrites [1, 2]. One characteristic morphological component of IOM is nanoglobules [3, 4]. Some nanoglobules exhibit large N-15 and D enrichments relative to solar values, indicating that they likely originated in the ISM or the outskirts of the protoplanetary disk [3]. A recent study of samples from the Tagish Lake meteorite with varying levels of hydrothermal alteration suggest that nanoglobule abundance decreases with increasing hydrothermal alteration [5]. The aim of this study is to further document the morphologies of IOM from a range of primitive chondrites in order to determine any correlation of morphology with petrographic grade and chondrite class that could constrain the formation and/or alteration mechanisms.

  3. Primary intraspinal extradural primitive neuroectodermal tumor: A rare case.

    Science.gov (United States)

    Rege, Shrikant V; Tadghare, Jitendra; Patil, Harshad; Narayan, Sharadendu

    2016-01-01

    Primitive neuroectodermal tumors (PNETs) are aggressive childhood malignancies and are difficult to treat. Primary intraspinal PNETs are rare. These patients have poor prognosis with short survival time even after surgery and chemoradiation. As there are no standard guidelines exist for the management of these tumors, a multidisciplinary approach has been employed with varying success. According to the review of literature, only few cases of primary intraspinal extradural PNETs have been reported. Herein, author has described a case of intraspinal, extradural PNET.

  4. Transitions between discrete and rhythmic primitives in a unimanual task

    Science.gov (United States)

    Sternad, Dagmar; Marino, Hamal; Charles, Steven K.; Duarte, Marcos; Dipietro, Laura; Hogan, Neville

    2013-01-01

    Given the vast complexity of human actions and interactions with objects, we proposed that control of sensorimotor behavior may utilize dynamic primitives. However, greater computational simplicity may come at the cost of reduced versatility. Evidence for primitives may be garnered by revealing such limitations. This study tested subjects performing a sequence of progressively faster discrete movements in order to “stress” the system. We hypothesized that the increasing pace would elicit a transition to rhythmic movements, assumed to be computationally and neurally more efficient. Abrupt transitions between the two types of movements would support the hypothesis that rhythmic and discrete movements are distinct primitives. Ten subjects performed planar point-to-point arm movements paced by a metronome: starting at 2 s, the metronome intervals decreased by 36 ms per cycle to 200 ms, stayed at 200 ms for several cycles, then increased by similar increments. Instructions emphasized to insert explicit stops between each movement with a duration that equaled the movement time. The experiment was performed with eyes open and closed, and with short and long metronome sounds, the latter explicitly specifying the dwell duration. Results showed that subjects matched instructed movement times but did not preserve the dwell times. Rather, they progressively reduced dwell time to zero, transitioning to continuous rhythmic movements before movement times reached their minimum. The acceleration profiles showed an abrupt change between discrete and rhythmic profiles. The loss of dwell time occurred earlier with long auditory specification, when subjects also showed evidence of predictive control. While evidence for hysteresis was weak, taken together, the results clearly indicated a transition between discrete and rhythmic movements, supporting the proposal that representation is based on primitives rather than on veridical internal models. PMID:23888139

  5. Transitions between Discrete and Rhythmic Primitives in a Unimanual Task

    Directory of Open Access Journals (Sweden)

    Dagmar eSternad

    2013-07-01

    Full Text Available Given the vast complexity of human actions and interactions with objects, we proposed that control of sensorimotor behavior may utilize dynamic primitives. However, greater computational simplicity may come at the cost of reduced versatility. Evidence for primitives may be garnered by revealing such limitations. This study tested subjects performing a sequence of progressively faster discrete movements, in order to stress the system. We hypothesized that the increasing pace would elicit a transition to rhythmic movements, assumed to be computationally and neurally more efficient. Abrupt transitions between the two types of movements would support the hypothesis that rhythmic and discrete movements are distinct primitives. Ten subjects performed planar point-to-point arm movements paced by a metronome: Starting at 2s the metronome intervals decreased by 36ms per cycle to 200ms, stayed at 200ms for several cycles, then increased by similar increments. Instructions emphasized to insert explicit stops between each movement with a duration that equaled the movement time. The experiment was performed with eyes open and closed, and with short and long metronome sounds, the latter explicitly specifying the dwell duration. Results showed that subjects matched instructed movement times but did not preserve the dwell times. Rather, they progressively reduced dwell time to zero, transitioning to continuous rhythmic movements before movement times reached their minimum. The acceleration profiles showed an abrupt change between discrete and rhythmic profiles. The loss of dwell time occurred earlier with long auditory specification, when subjects also showed evidence of predictive control. While evidence for hysteresis was weak, taken together, the results clearly indicated a transition between discrete and rhythmic movements, supporting the proposal that representation is based on primitives rather than on veridical internal models.

  6. Post-Quantum Cryptography: Riemann Primitives and Chrysalis

    OpenAIRE

    Malloy, Ian; Hollenbeck, Dennis

    2018-01-01

    The Chrysalis project is a proposed method for post-quantum cryptography using the Riemann sphere. To this end, Riemann primitives are introduced in addition to a novel implementation of this new method. Chrysalis itself is the first cryptographic scheme to rely on Holomorphic Learning with Errors, which is a complex form of Learning with Errors relying on the Gauss Circle Problem within the Riemann sphere. The principle security reduction proposed by this novel cryptographic scheme applies c...

  7. Primary extraskeletal Ewing's sarcoma/primitive neuroectodermal tumour of breast

    OpenAIRE

    Ikhwan, S M; Kenneth, V K T; Seoparjoo, A; Zin, A A M

    2013-01-01

    Primary primitive neuroectodermal tumour (PNET) and extraskeletal Ewing's sarcoma belongs to the Ewing's family of tumours. Primary tumours arising from breast are very rare. There are only a few case reports published on primary extraskeletal Ewing's sarcoma and PNET arising from breast. We present an extremely rare case of an inoperable primary Ewing's sarcoma arising from left breast with contralateral breast, lymphatic and lung metastasis.

  8. Primary extraskeletal Ewing's sarcoma/primitive neuroectodermal tumour of breast.

    Science.gov (United States)

    Ikhwan, S M; Kenneth, V K T; Seoparjoo, A; Zin, A A M

    2013-06-21

    Primary primitive neuroectodermal tumour (PNET) and extraskeletal Ewing's sarcoma belongs to the Ewing's family of tumours. Primary tumours arising from breast are very rare. There are only a few case reports published on primary extraskeletal Ewing's sarcoma and PNET arising from breast. We present an extremely rare case of an inoperable primary Ewing's sarcoma arising from left breast with contralateral breast, lymphatic and lung metastasis.

  9. PRIMITIVE MATRICES AND GENERATORS OF PSEUDO RANDOM SEQUENCES OF GALOIS

    Directory of Open Access Journals (Sweden)

    A. Beletsky

    2014-04-01

    Full Text Available In theory and practice of information cryptographic protection one of the key problems is the forming a binary pseudo-random sequences (PRS with a maximum length with acceptable statistical characteristics. PRS generators are usually implemented by linear shift register (LSR of maximum period with linear feedback [1]. In this paper we extend the concept of LSR, assuming that each of its rank (memory cell can be in one of the following condition. Let’s call such registers “generalized linear shift register.” The research goal is to develop algorithms for constructing Galois and Fibonacci generalized matrix of n-order over the field , which uniquely determined both the structure of corresponding generalized of n-order LSR maximal period, and formed on their basis Galois PRS generators of maximum length. Thus the article presents the questions of formation the primitive generalized Fibonacci and Galois arbitrary order matrix over the prime field . The synthesis of matrices is based on the use of irreducible polynomials of degree and primitive elements of the extended field generated by polynomial. The constructing methods of Galois and Fibonacci conjugated primitive matrices are suggested. The using possibilities of such matrices in solving the problem of constructing generalized generators of Galois pseudo-random sequences are discussed.

  10. On the Reduced Testing of a Primitive Element in ${\\\\mathbb Z}_n^\\\\times$

    OpenAIRE

    Suzuki, Hideo; スズキ, ヒデオ; Hideo, Suzuki

    2015-01-01

    The primitive roots in ${\\mathbb Z}_n^\\times$ are defined and exist iff $n = 2, 4, p^{\\alpha}, 2p^{\\alpha}$. Knuth gave the definition of the primitive roots in ${\\mathbb Z}_{p^\\alpha}^\\times$, and showed the necessary and sufficient condition for testing a primitive root in ${\\mathbb Z}_{p^\\alpha}^\\times$. In this paper we define the primitive elements in ${\\mathbb Z}_n^\\times$, which is a generalization of primitive roots, as elements that take the maximum multiplicative order.And we give t...

  11. Outlining and dictating scientific manuscripts is a useful method for health researchers: A focus group interview.

    Science.gov (United States)

    Andresen, Kristoffer; Laursen, Jannie; Rosenberg, Jacob

    2018-01-01

    Young researchers may experience difficulties when writing scientific articles for publication in biomedical journals. Various methods may facilitate the writing process including outlining the paper before the actual writing and using dictation instead of writing the first draft. The aim of this study was to investigate the experiences and difficulties for young, experienced researchers when writing articles using a detailed outline and dictation of the first draft. We used qualitative focus group interviews and the study was reported according to the COnsolidated criteria for REporting Qualitative research guideline. Participants were sampled from a group of researchers participating in a writing retreat/course. The interviews were recorded on a digital recorder and transcribed. The text was analyzed according to content analysis and coded and condensed into themes and subthemes. Groups of participants were added until data saturation was reached. A total of 14 researchers participated (9 women and 5 men). Their clinical experience was median (range) of 6 (1-11) years since graduation from medical school. Two themes arose during the analyses of the data: "Process guidance with the outline as the map" and "arrival at dictation." The outline was used in the preparation phase leading up to the day of dictation and was used in collaboration with co-authors and supervisors. The participants found it to be a useful tool for preparing the manuscript and dictating their initial first full draft. Experienced young researchers found beneficial effects of using a structured outline to prepare for dictation of scientific articles. The outline was a tool that would develop in close collaboration with co-authors and mentors. With dictation, a full first draft of a manuscript can be produced in a few hours. Participants positively evaluated this structured and reproducible way of producing scientific articles.

  12. Stem Cells from Cryopreserved Human Dental Pulp Tissues Sequentially Differentiate into Definitive Endoderm and Hepatocyte-Like Cells in vitro.

    Science.gov (United States)

    Han, Young-Jin; Kang, Young-Hoon; Shivakumar, Sarath Belame; Bharti, Dinesh; Son, Young-Bum; Choi, Yong-Ho; Park, Won-Uk; Byun, June-Ho; Rho, Gyu-Jin; Park, Bong-Wook

    2017-01-01

    We previously described a novel tissue cryopreservation protocol to enable the safe preservation of various autologous stem cell sources. The present study characterized the stem cells derived from long-term cryopreserved dental pulp tissues (hDPSCs-cryo) and analyzed their differentiation into definitive endoderm (DE) and hepatocyte-like cells (HLCs) in vitro . Human dental pulp tissues from extracted wisdom teeth were cryopreserved as per a slow freezing tissue cryopreservation protocol for at least a year. Characteristics of hDPSCs-cryo were compared to those of stem cells from fresh dental pulps (hDPSCs-fresh). hDPSCs-cryo were differentiated into DE cells in vitro with Activin A as per the Wnt3a protocol for 6 days. These cells were further differentiated into HLCs in the presence of growth factors until day 30. hDPSCs-fresh and hDPSCs-cryo displayed similar cell growth morphology, cell proliferation rates, and mesenchymal stem cell character. During differentiation into DE and HLCs in vitro , the cells flattened and became polygonal in shape, and finally adopted a hepatocyte-like shape. The differentiated DE cells at day 6 and HLCs at day 30 displayed significantly increased DE- and hepatocyte-specific markers at the mRNA and protein level, respectively. In addition, the differentiated HLCs showed detoxification and glycogen storage capacities, indicating they could share multiple functions with real hepatocytes. These data conclusively show that hPDSCs-cryo derived from long-term cryopreserved dental pulp tissues can be successfully differentiated into DE and functional hepatocytes in vitro . Thus, preservation of dental tissues could provide a valuable source of autologous stem cells for tissue engineering.

  13. Partner Selection and the Division of Surplus: Evidence from Ultimatum and Dictator Experiments

    Directory of Open Access Journals (Sweden)

    Priyodorshi Banerjee

    2016-01-01

    Full Text Available We study ultimatum and dictator environments with one-way, unenforceable pre-play communication from the proposer to the recipient, semantically framed as a promise. After observing this promise regarding how much the proposer will offer if selected, in our treatment conditions, recipients choose whether or not to select a particular proposer. We find that offers can increase in the ultimatum game both with non-competitive selection with a single potential proposer, and more so with competition, where the recipient chooses one of two potential proposers, as compared to the no selection baseline. Furthermore, the offer is rejected with higher probability if the promisemade by the selected proposer is higher than the eventual offer. Our dictator environment does not give the power to reject offers, thus selection power carries no benefits in the dictator game. Finally, independent of the game institution or proposer selection mechanism, promises provide credible signals for offers.

  14. Deducing trapdoor primitives in public key encryption schemes

    Science.gov (United States)

    Pandey, Chandra

    2005-03-01

    Semantic security of public key encryption schemes is often interchangeable with the art of building trapdoors. In the frame of reference of Random Oracle methodology, the "Key Privacy" and "Anonymity" has often been discussed. However to a certain degree the security of most public key encryption schemes is required to be analyzed with formal proofs using one-way functions. This paper evaluates the design of El Gamal and RSA based schemes and attempts to parallelize the trapdoor primitives used in the computation of the cipher text, thereby magnifying the decryption error δp in the above schemes.

  15. Thoracoabdominal peripheral primitive neuroectodermal tumors in childhood: radiological features

    International Nuclear Information System (INIS)

    Schulman, H.; Laufer, L.; Newman-Heinman, N.; Kurtzbart, E.; Maor, E.; Zirkin, H.

    2000-01-01

    Peripheral primitive neuroectodermal tumors (PNET) are extremely uncommon, malignant neoplasms affecting mostly children and young adults. We retrospectively reviewed the clinical data and radiological studies of four such cases. All cases were pathologically proven. Plain films, US, and CT scans were used. The youngest child had a huge pelvic tumor and two adolescents each had a chest wall (Askin) tumor. The fourth patient had a most unusual location of the PNET in the anterior mediastinum. The CT findings are emphasized. We emphasize that the markedly abnormal CT findings are not specific for PNET. (orig.)

  16. Characterizing Digital Light Processing (DLP) 3D Printed Primitives

    DEFF Research Database (Denmark)

    Tyge, Emil; Pallisgaard, Jens J.; Lillethorup, Morten

    2015-01-01

    The resolution and repeatability of 3D printing processes depends on a number of factors including the software, hardware, and material used. When printing parts with features that are near or below the nominal printing resolution, it is important to understand how the printer works. For example......, what is the smallest unit shape that can be produced? And what is the reproducibility of that process? This paper presents a method for automatically detecting and characterizing the height, width, and length of micro scale geometric primitives produced via a digital light processing (DLP) 3D printing...

  17. Dust formation in a galaxy with primitive abundances.

    Science.gov (United States)

    Sloan, G C; Matsuura, M; Zijlstra, A A; Lagadec, E; Groenewegen, M A T; Wood, P R; Szyszka, C; Bernard-Salas, J; van Loon, J Th

    2009-01-16

    Interstellar dust plays a crucial role in the evolution of galaxies. It governs the chemistry and physics of the interstellar medium. In the local universe, dust forms primarily in the ejecta from stars, but its composition and origin in galaxies at very early times remain controversial. We report observational evidence of dust forming around a carbon star in a nearby galaxy with a low abundance of heavy elements, 25 times lower than the solar abundance. The production of dust by a carbon star in a galaxy with such primitive abundances raises the possibility that carbon stars contributed carbonaceous dust in the early universe.

  18. CAD-based Monte Carlo automatic modeling method based on primitive solid

    International Nuclear Information System (INIS)

    Wang, Dong; Song, Jing; Yu, Shengpeng; Long, Pengcheng; Wang, Yongliang

    2016-01-01

    Highlights: • We develop a method which bi-convert between CAD model and primitive solid. • This method was improved from convert method between CAD model and half space. • This method was test by ITER model and validated the correctness and efficiency. • This method was integrated in SuperMC which could model for SuperMC and Geant4. - Abstract: Monte Carlo method has been widely used in nuclear design and analysis, where geometries are described with primitive solids. However, it is time consuming and error prone to describe a primitive solid geometry, especially for a complicated model. To reuse the abundant existed CAD models and conveniently model with CAD modeling tools, an automatic modeling method for accurate prompt modeling between CAD model and primitive solid is needed. An automatic modeling method for Monte Carlo geometry described by primitive solid was developed which could bi-convert between CAD model and Monte Carlo geometry represented by primitive solids. While converting from CAD model to primitive solid model, the CAD model was decomposed into several convex solid sets, and then corresponding primitive solids were generated and exported. While converting from primitive solid model to the CAD model, the basic primitive solids were created and related operation was done. This method was integrated in the SuperMC and was benchmarked with ITER benchmark model. The correctness and efficiency of this method were demonstrated.

  19. 4. Assessment Typologies Used Within the Discipline Theory, Solfeggio, Musical Dictation

    Directory of Open Access Journals (Sweden)

    Duţică Luminiţa

    2018-03-01

    Full Text Available Assessment is a distinct stage within the teaching process, aiming to measure the level of the knowledge, skills and competences acquired within a given time frame. The discipline Theory, Solfeggio, Musical Dictation involves a synthesis between the theoretical and the practical side of the matter, and, as a result, it uses specific assessment tools for each side. Modern assessment methods involve personalized systems based on the diversification of types of docimological tests, quizzes, practical tests, etc. In this study we will present a series of personal contributions referring to the contents specific to the discipline Theory, Solfeggio, Musical Dictation taught at university.

  20. Stochastic Ocean Predictions with Dynamically-Orthogonal Primitive Equations

    Science.gov (United States)

    Subramani, D. N.; Haley, P., Jr.; Lermusiaux, P. F. J.

    2017-12-01

    The coastal ocean is a prime example of multiscale nonlinear fluid dynamics. Ocean fields in such regions are complex and intermittent with unstationary heterogeneous statistics. Due to the limited measurements, there are multiple sources of uncertainties, including the initial conditions, boundary conditions, forcing, parameters, and even the model parameterizations and equations themselves. For efficient and rigorous quantification and prediction of these uncertainities, the stochastic Dynamically Orthogonal (DO) PDEs for a primitive equation ocean modeling system with a nonlinear free-surface are derived and numerical schemes for their space-time integration are obtained. Detailed numerical studies with idealized-to-realistic regional ocean dynamics are completed. These include consistency checks for the numerical schemes and comparisons with ensemble realizations. As an illustrative example, we simulate the 4-d multiscale uncertainty in the Middle Atlantic/New York Bight region during the months of Jan to Mar 2017. To provide intitial conditions for the uncertainty subspace, uncertainties in the region were objectively analyzed using historical data. The DO primitive equations were subsequently integrated in space and time. The probability distribution function (pdf) of the ocean fields is compared to in-situ, remote sensing, and opportunity data collected during the coincident POSYDON experiment. Results show that our probabilistic predictions had skill and are 3- to 4- orders of magnitude faster than classic ensemble schemes.

  1. CT and MR findings of primitive neuroectodermal tumor

    International Nuclear Information System (INIS)

    Kook, Shin Ho; Kim, In One; Chang, Kee Hyun; Han, Moon Hee; Cho, Byung Kyu

    1991-01-01

    Cerebral primitive neuroectodermal tumor (PNET), consisting of undifferentiated primitive cells, is a neoplasm of children and young adults that occurs predominantly in the supratentorial compartment. In this report, we retrospectively reviewed and analyzed 18 CT and 6 MR findings in 18 patients with pathologically-proven PNET to discover the characteristic findings, if may. The most characteristic feature of the PNETs was a well-defined multilobular oval or round large mass with components of peripheral cystic change or calcification in the cerebral hemisphere, especially in the parietal lobe. Usually there was only minimal surrounding edema. The CT density of the tumor was iso - or slightly high density with homogeneous contrast enhancement in the solid portion and low density in the cystic area. MR findings demonstrated iso - signal intensity on both T1 - weighted (T1WI) and T2-weighted (T2WI) images and dense enhancement in the solid element. The cystic portion revealed low intensity on T1WI and high intensity on T2WI

  2. Effects of primitive photosynthesis on Earth's early climate system

    Science.gov (United States)

    Ozaki, Kazumi; Tajika, Eiichi; Hong, Peng K.; Nakagawa, Yusuke; Reinhard, Christopher T.

    2018-01-01

    The evolution of different forms of photosynthetic life has profoundly altered the activity level of the biosphere, radically reshaping the composition of Earth's oceans and atmosphere over time. However, the mechanistic impacts of a primitive photosynthetic biosphere on Earth's early atmospheric chemistry and climate are poorly understood. Here, we use a global redox balance model to explore the biogeochemical and climatological effects of different forms of primitive photosynthesis. We find that a hybrid ecosystem of H2-based and Fe2+-based anoxygenic photoautotrophs—organisms that perform photosynthesis without producing oxygen—gives rise to a strong nonlinear amplification of Earth's methane (CH4) cycle, and would thus have represented a critical component of Earth's early climate system before the advent of oxygenic photosynthesis. Using a Monte Carlo approach, we find that a hybrid photosynthetic biosphere widens the range of geochemical conditions that allow for warm climate states well beyond either of these metabolic processes acting in isolation. Our results imply that the Earth's early climate was governed by a novel and poorly explored set of regulatory feedbacks linking the anoxic biosphere and the coupled H, C and Fe cycles. We suggest that similar processes should be considered when assessing the potential for sustained habitability on Earth-like planets with reducing atmospheres.

  3. Medulloblastomas - primitive neuroectodermal tumours in the adult population

    International Nuclear Information System (INIS)

    Smee, R.I.; Williams, J.R.

    2008-01-01

    Medulloblastomas - primitive neuroectodermal tumours are rare in adults. This review will evaluate a single centre's experience with this malignancy. The medulloblastoma - primitive neuroectodermal tumour database was evaluated for all patients aged more than 18 years who were referred for management. Relevant information from the database was abstracted to provide a descriptive record of this malignancy. Between 1977-2004 there were 11 patients referred, 1 with persistent disease and 10 were eligible, presenting with initial diagnosis. There was increased intracranial pressure in 50% of patients. Most patients had symptoms >3 months, with three having symptoms 1-3 months before diagnosis and one patient having thoracic dural metastases at presentation. Complete resection was recorded in four patients and six had 50-90% resection. All patients completed craniospinal radiotherapy (35-36 Gy at 1.8-2.0 Gy fractions) barring one patient, who died of surgical complications during his radiotherapy. Chemotherapy was given in five of the nine patients postradiotherapy. There were two posterior fossa recurrences, with associated supratentorial and extra central nervous system disease. Of the 10 primary patients 7 are alive with no evidence of diease, 2 died because of disease, with 1 intercurrent death. One patient developed a second malignancy. The outcome for adults matches that of the more common paediatric patients. Radiotherapy could control local disease even where complete resection was not achieved.

  4. Identifying the primitive path mesh in entangled polymer liquids

    International Nuclear Information System (INIS)

    Sukumaran, Sathish K.; Kremer, Kurt; Grest, Gary Stephen; Everaers, Ralf

    2004-01-01

    Similar to entangled ropes, polymer chains cannot slide through each other. These topological constraints, the so-called entanglements, dominate the viscoelastic behavior of high-molecular-weight polymeric liquids. Tube models of polymer dynamics and rheology are based on the idea that entanglements confine a chain to small fluctuations around a primitive path which follows the coarse-grained chain contour. To establish the microscopic foundation for these highly successful phenomenological models, we have recently introduced a method for identifying the primitive path mesh that characterizes the microscopic topological state of computer-generated conformations of long-chain polymer melts and solutions. Here we give a more detailed account of the algorithm and discuss several key aspects of the analysis that are pertinent for its successful use in analyzing the topology of the polymer configurations. We also present a slight modification of the algorithm that preserves the previously neglected self-entanglements and allows us to distinguish between local self-knots and entanglements between distant sections of the same chain. Our results indicate that the latter make a negligible contribution to the tube and that the contour length between local self-knots, N 1k is significantly larger than the entanglement length N e

  5. An online gait generator for quadruped walking using motor primitives

    Directory of Open Access Journals (Sweden)

    Chunlin Zhou

    2016-11-01

    Full Text Available This article presents implementation of an online gait generator on a quadruped robot. Firstly, the design of a quadruped robot is presented. The robot contains four leg modules each of which is constructed by a 2 degrees of freedom (2-DOF five-bar parallel linkage mechanism. Together with other two rotational DOF, the leg module is able to perform 4-DOF movement. The parallel mechanism of the robot allows all the servos attached on the body frame, so that the leg mass is decreased and motor load can be balanced. Secondly, an online gait generator based on dynamic movement primitives for the walking control is presented. Dynamic movement primitives provide an approach to generate periodic trajectories and they can be modulated in real time, which makes the online adjustment of walking gaits possible. This gait controller is tested by the quadruped robot in regulating walking speed, switching between forward\\backward movements and steering. The controller is easy to apply, expand and is quite effective on phase coordination and online trajectory modulation. Results of simulated experiments are presented.

  6. Melodic Dictation Instruction: A Survey of Advanced Placement Music Theory Teachers

    Science.gov (United States)

    Buonviri, Nathan O.; Paney, Andrew S.

    2015-01-01

    Based on relevant literature and recent qualitative findings, the purpose of this survey research was to identify pedagogical approaches to melodic dictation employed by Advanced Placement (AP) Music Theory teachers across the United States. The researcher-designed survey questions focused on pitch and rhythm skills, instructional resources,…

  7. Written Spelling to Dictation: Sound-To-Spelling Regularity Affects Both Writing Latencies and Durations

    Science.gov (United States)

    Delattre, Marie; Bonin, Patrick; Barry, Christopher

    2006-01-01

    The authors examined the effect of sound-to-spelling regularity on written spelling latencies and writing durations in a dictation task in which participants had to write each target word 3 times in succession. The authors found that irregular words (i.e., those containing low-probability phoneme-to-grapheme mappings) were slower both to…

  8. Locus of Word Frequency Effects in Spelling to Dictation: Still at the Orthographic Level!

    Science.gov (United States)

    Bonin, Patrick; Laroche, Betty; Perret, Cyril

    2016-01-01

    The present study was aimed at testing the locus of word frequency effects in spelling to dictation: Are they located at the level of spoken word recognition (Chua & Rickard Liow, 2014) or at the level of the orthographic output lexicon (Delattre, Bonin, & Barry, 2006)? Words that varied on objective word frequency and on phonological…

  9. The Effect of the Tuning System and Instrument Variables on Modal Dictation Performance

    Science.gov (United States)

    Demirbatir, Rasim Erol; Çeliktas, Hatice; Engür, Doruk

    2018-01-01

    Ear training and musical literacy (ETML) education is one of the main dimensions of the bachelor degree program of music teacher education departments, which provides professional music education. In ETML education, hearing, sight-reading and dictation studies for Turkish music makams have an important place. In this study, it was aimed to…

  10. Locus of word frequency effects in spelling to dictation: Still at the orthographic level!

    Science.gov (United States)

    Bonin, Patrick; Laroche, Betty; Perret, Cyril

    2016-11-01

    The present study was aimed at testing the locus of word frequency effects in spelling to dictation: Are they located at the level of spoken word recognition (Chua & Rickard Liow, 2014) or at the level of the orthographic output lexicon (Delattre, Bonin, & Barry, 2006)? Words that varied on objective word frequency and on phonological neighborhood density were orally presented to adults who had to write them down. Following the additive factors logic (Sternberg, 1969, 2001), if word frequency in spelling to dictation influences a processing level, that is, the orthographic output level, different from that influenced by phonological neighborhood density, that is, spoken word recognition, the impact of the 2 factors should be additive. In contrast, their influence should be overadditive if they act at the same processing level in spelling to dictation, namely the spoken word recognition level. We found that both factors had a reliable influence on the spelling latencies but did not interact. This finding is in line with an orthographic output locus hypothesis of word frequency effects in spelling to dictation. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

  11. Developing Students' Listening Metacognitive Strategies Using Online Videotext Self-Dictation-Generation Learning Activity

    Science.gov (United States)

    Chang, Ching; Chang, Chih-Kai

    2014-01-01

    The study is based on the use of a flexible learning framework to help students improve information processes underlying strategy instruction in EFL listening. By exploiting the online videotext self-dictation-generation (video-SDG) learning activity implemented on the YouTube caption manager platform, the learning cycle was emphasized to promote…

  12. The dictator effect: how long years in office affect economic development

    NARCIS (Netherlands)

    Papaioannou, Kostadis; van Zanden, Jan Luiten

    This paper contributes to the growing literature on the links between political regimes and economic development by studying the effects of years in office on economic development. The hypothesis is that dictators who stay in office for a long time period will find it increasingly difficult to carry

  13. The dictator effect: how long years in office affect economic development

    NARCIS (Netherlands)

    Papaioannou, K.I.; Zanden, van J.L.

    2015-01-01

    This paper contributes to the growing literature on the links between political regimes and economic development by studying the effects of years in office on economic development. The hypothesis is that dictators who stay in office for a long time period will find it increasingly difficult to carry

  14. Measuring Altruistic Behavior in Surveys: The All-or-Nothing Dictator Game

    Directory of Open Access Journals (Sweden)

    Rene Bekkers

    2007-12-01

    Full Text Available A field study of altruistic behaviour is presented using a modification of the dictator game in a large random sample survey in the netherlands (n=1,964. In line with laboratory experiments, only 5.7% donated money. In line with other survey research on giving, generosity increased with age, education, income, trust, and prosocial value orientation.

  15. The effect of $1, $5 and $10 stakes in an online dictator game.

    Science.gov (United States)

    Raihani, Nichola J; Mace, Ruth; Lamba, Shakti

    2013-01-01

    The decision rules underpinning human cooperative behaviour are often investigated under laboratory conditions using monetary incentives. A major concern with this approach is that stake size may bias subjects' decisions. This concern is particularly acute in online studies, where stakes are often far lower than those used in laboratory or field settings. We address this concern by conducting a Dictator Game using Amazon Mechanical Turk. In this two-player game, one player (the dictator) determines the division of an endowment between himself and the other player. We recruited subjects from India and the USA to play an online Dictator Game. Dictators received endowments of $1, $5 or $10. We collected two batches of data over two consecutive years. We found that players from India were less generous when playing with a $10 stake. By contrast, the effect of stake size among players from the USA was very small. This study indicates that the effects of stake size on decision making in economic games may vary across populations.

  16. The effect of $1, $5 and $10 stakes in an online dictator game.

    Directory of Open Access Journals (Sweden)

    Nichola J Raihani

    Full Text Available The decision rules underpinning human cooperative behaviour are often investigated under laboratory conditions using monetary incentives. A major concern with this approach is that stake size may bias subjects' decisions. This concern is particularly acute in online studies, where stakes are often far lower than those used in laboratory or field settings. We address this concern by conducting a Dictator Game using Amazon Mechanical Turk. In this two-player game, one player (the dictator determines the division of an endowment between himself and the other player. We recruited subjects from India and the USA to play an online Dictator Game. Dictators received endowments of $1, $5 or $10. We collected two batches of data over two consecutive years. We found that players from India were less generous when playing with a $10 stake. By contrast, the effect of stake size among players from the USA was very small. This study indicates that the effects of stake size on decision making in economic games may vary across populations.

  17. 18 Dictation as a Veritable Tool for Language Proficiency on Project ...

    African Journals Online (AJOL)

    User

    Dictation is a valuable language teaching and learning device that has been used for centuries ... English language among the second learners of English language in a ... through effective study English by developing the language curriculum and ... language teachers need to be abreast with different methods of language.

  18. English-to-Japanese Translation vs. Dictation vs. Post-editing

    DEFF Research Database (Denmark)

    Carl, Michael; Aizawa, Akiko; Yamada, Masaru

    2016-01-01

    of text production. This paper introduces and evaluates a corpus of more than 55 hours of English-to-Japanese user activity data that were collected within the ENJA15 project, in which translators were observed while writing and speaking translations (translation dictation) and during machine translation...

  19. Allowing for Reflection Time does not Change Behavior in Dictator and Cheating Games

    DEFF Research Database (Denmark)

    Andersen, Steffen; Gneezy, Uri; Kajackaite, Agne

    2018-01-01

    Reaction time, usually measured in seconds, has been shown to be correlated with decisions in experimental games. In this paper, we study how allowing for a full day of “reflection time” alters behavior. We compare behavior in dictator and cheating games when participants make immediate choices...

  20. FGF signaling via MAPK is required early and improves Activin A-induced definitive endoderm formation from human embryonic stem cells

    Energy Technology Data Exchange (ETDEWEB)

    Sui, Lina, E-mail: linasui@vub.ac.be [Cell Differentiation Unit, Diabetes Research Center, Vrije Universiteit Brussel (VUB), Laarbeeklaan 103, 1090 Brussels (Belgium); Mfopou, Josue K. [Cell Differentiation Unit, Diabetes Research Center, Vrije Universiteit Brussel (VUB), Laarbeeklaan 103, 1090 Brussels (Belgium); Geens, Mieke; Sermon, Karen [Department of Embryology and Genetics, Vrije Universiteit Brussel (VUB), Laarbeeklaan 103, 1090 Brussels (Belgium); Bouwens, Luc [Cell Differentiation Unit, Diabetes Research Center, Vrije Universiteit Brussel (VUB), Laarbeeklaan 103, 1090 Brussels (Belgium)

    2012-09-28

    Highlights: Black-Right-Pointing-Pointer Deep study the FGF signaling role during DE specification in the context of hESCs. Black-Right-Pointing-Pointer DE differentiation from hESCs has an early dependence on FGF signaling. Black-Right-Pointing-Pointer A serum-free DE protocol is developed based on the findings. Black-Right-Pointing-Pointer The DE cells showed potential to differentiate into pancreatic progenitor cells. -- Abstract: Considering their unlimited proliferation and pluripotency properties, human embryonic stem cells (hESCs) constitute a promising resource applicable for cell replacement therapy. To facilitate this clinical translation, it is critical to study and understand the early stage of hESCs differentiation wherein germ layers are defined. In this study, we examined the role of FGF signaling in Activin A-induced definitive endoderm (DE) differentiation in the absence of supplemented animal serum. We found that activated FGF/MAPK signaling is required at the early time point of Activin A-induced DE formation. In addition, FGF activation increased the number of DE cells compared to Activin A alone. These DE cells could further differentiate into PDX1 and NKX6.1 positive pancreatic progenitors in vitro. We conclude that Activin A combined with FGF/MAPK signaling efficiently induce DE cells in the absence of serum. These findings improve our understanding of human endoderm formation, and constitute a step forward in the generation of clinical grade hESCs progenies for cell therapy.

  1. FGF signaling via MAPK is required early and improves Activin A-induced definitive endoderm formation from human embryonic stem cells

    International Nuclear Information System (INIS)

    Sui, Lina; Mfopou, Josué K.; Geens, Mieke; Sermon, Karen; Bouwens, Luc

    2012-01-01

    Highlights: ► Deep study the FGF signaling role during DE specification in the context of hESCs. ► DE differentiation from hESCs has an early dependence on FGF signaling. ► A serum-free DE protocol is developed based on the findings. ► The DE cells showed potential to differentiate into pancreatic progenitor cells. -- Abstract: Considering their unlimited proliferation and pluripotency properties, human embryonic stem cells (hESCs) constitute a promising resource applicable for cell replacement therapy. To facilitate this clinical translation, it is critical to study and understand the early stage of hESCs differentiation wherein germ layers are defined. In this study, we examined the role of FGF signaling in Activin A-induced definitive endoderm (DE) differentiation in the absence of supplemented animal serum. We found that activated FGF/MAPK signaling is required at the early time point of Activin A-induced DE formation. In addition, FGF activation increased the number of DE cells compared to Activin A alone. These DE cells could further differentiate into PDX1 and NKX6.1 positive pancreatic progenitors in vitro. We conclude that Activin A combined with FGF/MAPK signaling efficiently induce DE cells in the absence of serum. These findings improve our understanding of human endoderm formation, and constitute a step forward in the generation of clinical grade hESCs progenies for cell therapy.

  2. Evidence for extreme Ti-50 enrichments in primitive meteorites

    International Nuclear Information System (INIS)

    Fahey, A.; Mckeegan, K.D.; Zinner, E.; Goswami, J.N.; Physical Research Lab., Ahmedabad, India)

    1985-01-01

    The results of the first high mass resolution ion microprobe study of Ti isotopic compositions in individual refractory grains from primitive carbonaceous meteorites are reported. One hibonite from the Murray carbonaceous chondrite has a 10 percent excess of Ti-50, 25 times higher than the maximum value previously reported for bulk samples of refractory inclusions from carbonaceous chondrites. The variation of the Ti compositions between different hibonite grains, and among pyroxenes from a single Allende refractory inclusion, indicates isotopic inhomogeneities over small scale lengths in the solar nebula and emphasizes the importance of the analysis of small individual phases. This heterogeneity makes it unlikely that the isotopic anomalies were carried into the solar system in the gas phase. 20 references

  3. The CHY representation of tree-level primitive QCD amplitudes

    International Nuclear Information System (INIS)

    Cruz, Leonardo de la; Kniss, Alexander; Weinzierl, Stefan

    2015-01-01

    In this paper we construct a CHY representation for all tree-level primitive QCD amplitudes. The quarks may be massless or massive. We define a generalised cyclic factor Ĉ(w,z) and a generalised permutation invariant function Ê(z,p,ε). The amplitude is then given as a contour integral encircling the solutions of the scattering equations with the product ĈÊ as integrand. Equivalently, it is given as a sum over the inequivalent solutions of the scattering equations, where the summand consists of a Jacobian times the product ĈÊ. This representation separates information: The generalised cyclic factor does not depend on the helicities of the external particles, the generalised permutation invariant function does not depend on the ordering of the external particles.

  4. Evolution of lung breathing from a lungless primitive vertebrate.

    Science.gov (United States)

    Hoffman, M; Taylor, B E; Harris, M B

    2016-04-01

    Air breathing was critical to the terrestrial radiation and evolution of tetrapods and arose in fish. The vertebrate lung originated from a progenitor structure present in primitive boney fish. The origin of the neural substrates, which are sensitive to metabolically produced CO2 and which rhythmically activate respiratory muscles to match lung ventilation to metabolic demand, is enigmatic. We have found that a distinct periodic centrally generated rhythm, described as "cough" and occurring in lamprey in vivo and in vitro, is modulated by central sensitivity to CO2. This suggests that elements critical for the evolution of breathing in tetrapods, were present in the most basal vertebrate ancestors prior to the evolution of the lung. We propose that the evolution of breathing in all vertebrates occurred through exaptations derived from these critical basal elements. Copyright © 2015 Elsevier B.V. All rights reserved.

  5. Amylose primitive médiastinale d'aspect pseudotumoral

    Science.gov (United States)

    Mahfoudhi, Madiha; Mamlouk, Habiba; Turki, Sami; Kheder, Adel

    2015-01-01

    L'amylose primitive médiastinale isolée est rare et de diagnostic difficile. Nous rapportons l'observation d'un patient âgé de 41 ans ayant présenté une dyspnée et des crachats hémoptoïques. A l'examen physique il n'avait pas d'hypotension orthostatique. Les aires ganglionnaires périphériques étaient libres. La tomodensitométrie thoracique a objectivé un magma d'adénopathies médiastinales réalisant une masse de 45 mm x 60 mm. L'examen anatomopathologique d'une biopsie ganglionnaire guidée par médiastinoscopie a conclut a une amylose médiastinale de type AL. Il n'avait pas d'autres localisations amyloïdes. Un myélome multiple a été éliminé. Le diagnostic d'amylose primitive médiastinale de type AL a été retenu. Le traitement s'est basé sur des cures de Melphalan-prednisone. La chirurgie était évitée vu le risque hémorragique élevé. L’évolution était marquée par l'amélioration de la dyspnée, la disparition de l'hémoptysie et la diminution de la taille de la masse ganglionnaire devenant 25 mm x 20 mm. PMID:26308913

  6. Limitations of the Dual-Process-Theory regarding the Writing of Words and Non-Words to Dictation

    Science.gov (United States)

    Tucha, Oliver; Trumpp, Christian; Lange, Klaus W.

    2004-01-01

    It is generally assumed that the lexical and phonological systems are involved in writing to dictation. In an experiment concerned with the writing of words and non-words to dictation, the handwriting of female students was registered using a digitising tablet. The data contradict the assumption that the phonological system represents an alexical…

  7. The first trimester human placenta is a site for terminal maturation of primitive erythroid cells.

    Science.gov (United States)

    Van Handel, Ben; Prashad, Sacha L; Hassanzadeh-Kiabi, Nargess; Huang, Andy; Magnusson, Mattias; Atanassova, Boriana; Chen, Angela; Hamalainen, Eija I; Mikkola, Hanna K A

    2010-10-28

    Embryonic hematopoiesis starts via the generation of primitive red blood cells (RBCs) that satisfy the embryo's immediate oxygen needs. Although primitive RBCs were thought to retain their nuclei, recent studies have shown that primitive RBCs in mice enucleate in the fetal liver. It has been unknown whether human primitive RBCs enucleate, and what hematopoietic site might support this process. Our data indicate that the terminal maturation and enucleation of human primitive RBCs occurs in first trimester placental villi. Extravascular ζ-globin(+) primitive erythroid cells were found in placental villi between 5-7 weeks of development, at which time the frequency of enucleated RBCs was higher in the villous stroma than in circulation. RBC enucleation was further evidenced by the presence of primitive reticulocytes and pyrenocytes (ejected RBC nuclei) in the placenta. Extravascular RBCs were found to associate with placental macrophages, which contained ingested nuclei. Clonogenic macrophage progenitors of fetal origin were present in the chorionic plate of the placenta before the onset of fetoplacental circulation, after which macrophages had migrated to the villi. These findings indicate that placental macrophages may assist the enucleation process of primitive RBCs in placental villi, implying an unexpectedly broad role for the placenta in embryonic hematopoiesis.

  8. When Ignorance is Bliss - Information Asymmetries Enhance Prosocial Behavior in Dictator Games

    OpenAIRE

    Evguenia Winschel; Philipp Zahn

    2014-01-01

    In most laboratory experiments concerning prosocial behavior subjects are fully informed how their decision influences the payoff of other players. Outside the laboratory, however, individuals typically have to decide without such detailed knowledge. To assess the effect of information asymmetries on prosocial behavior, we conduct a laboratory experiment with a simple non-strategic interaction. A dictator has only limited knowledge about the benefits his prosocial action generates for a recip...

  9. The locus of word frequency effects in skilled spelling-to-dictation.

    Science.gov (United States)

    Chua, Shi Min; Liow, Susan J Rickard

    2014-01-01

    In spelling-to-dictation tasks, skilled spellers consistently initiate spelling of high-frequency words faster than that of low-frequency words. Tainturier and Rapp's model of spelling shows three possible loci for this frequency effect: spoken word recognition, orthographic retrieval, and response execution of the first letter. Thus far, researchers have attributed the effect solely to orthographic retrieval without considering spoken word recognition or response execution. To investigate word frequency effects at each of these three loci, Experiment 1 involved a delayed spelling-to-dictation task and Experiment 2 involved a delayed/uncertain task. In Experiment 1, no frequency effect was found in the 1200-ms delayed condition, suggesting that response execution is not affected by word frequency. In Experiment 2, no frequency effect was found in the delayed/uncertain task that reflects the orthographic retrieval, whereas a frequency effect was found in the comparison immediate/uncertain task that reflects both spoken word recognition and orthographic retrieval. The results of this two-part study suggest that frequency effects in spoken word recognition play a substantial role in skilled spelling-to-dictation. Discrepancies between these findings and previous research, and the limitations of the present study, are discussed.

  10. Specific acoustic models for spontaneous and dictated style in indonesian speech recognition

    Science.gov (United States)

    Vista, C. B.; Satriawan, C. H.; Lestari, D. P.; Widyantoro, D. H.

    2018-03-01

    The performance of an automatic speech recognition system is affected by differences in speech style between the data the model is originally trained upon and incoming speech to be recognized. In this paper, the usage of GMM-HMM acoustic models for specific speech styles is investigated. We develop two systems for the experiments; the first employs a speech style classifier to predict the speech style of incoming speech, either spontaneous or dictated, then decodes this speech using an acoustic model specifically trained for that speech style. The second system uses both acoustic models to recognise incoming speech and decides upon a final result by calculating a confidence score of decoding. Results show that training specific acoustic models for spontaneous and dictated speech styles confers a slight recognition advantage as compared to a baseline model trained on a mixture of spontaneous and dictated training data. In addition, the speech style classifier approach of the first system produced slightly more accurate results than the confidence scoring employed in the second system.

  11. Inconsistent formation and nonfunction of insulin-positive cells from pancreatic endoderm derived from human embryonic stem cells in athymic nude rats.

    Science.gov (United States)

    Matveyenko, Aleksey V; Georgia, Senta; Bhushan, Anil; Butler, Peter C

    2010-11-01

    Embryonic stem cell therapy has been proposed as a therapeutic strategy to restore β-cell mass and function in T1DM. Recently, a group from Novocell (now ViaCyte) reported successful development of glucose-responsive islet-like structures after implantation of pancreatic endoderm (PE) derived from human embryonic stem cells (hESC) into immune-deficient mice. Our objective was to determine whether implantation of hESC-derived pancreatic endoderm from Novocell into athymic nude rats results in development of viable glucose-responsive pancreatic endocrine tissue. Athymic nude rats were implanted with PE derived from hESC either via implantation into the epididymal fat pads or by subcutaneous implantation into TheraCyte encapsulation devices for 20 wk. Blood glucose, weight, and human insulin/C-peptide secretion were monitored by weekly blood draws. Graft β-cell function was assessed by a glucose tolerance test, and graft morphology was assessed by immunohistochemistry and immunofluorescence. At 20 wk postimplantation, epididymal fat-implanted PE progressed to develop islet-like structures in 50% of implants, with a mean β-cell fractional area of 0.8 ± 0.3%. Human C-peptide and insulin were detectable, but at very low levels (C-peptide = 50 ± 26 pmol/l and insulin = 15 ± 7 pmol/l); however, there was no increase in human C-peptide/insulin levels after glucose challenge. There was no development of viable pancreatic tissue or meaningful secretory function when human PE was implanted in the TheraCyte encapsulation devices. These data confirm that islet-like structures develop from hESC differentiated to PE by the protocol developed by NovoCell. However, the extent of endocrine cell formation and secretory function is not yet sufficient to be clinically relevant.

  12. The formation of endoderm-derived taste sensory organs requires a Pax9-dependent expansion of embryonic taste bud progenitor cells.

    Directory of Open Access Journals (Sweden)

    Ralf Kist

    2014-10-01

    Full Text Available In mammals, taste buds develop in different regions of the oral cavity. Small epithelial protrusions form fungiform papillae on the ectoderm-derived dorsum of the tongue and contain one or few taste buds, while taste buds in the soft palate develop without distinct papilla structures. In contrast, the endoderm-derived circumvallate and foliate papillae located at the back of the tongue contain a large number of taste buds. These taste buds cluster in deep epithelial trenches, which are generated by intercalating a period of epithelial growth between initial placode formation and conversion of epithelial cells into sensory cells. How epithelial trench formation is genetically regulated during development is largely unknown. Here we show that Pax9 acts upstream of Pax1 and Sox9 in the expanding taste progenitor field of the mouse circumvallate papilla. While a reduced number of taste buds develop in a growth-retarded circumvallate papilla of Pax1 mutant mice, its development arrests completely in Pax9-deficient mice. In addition, the Pax9 mutant circumvallate papilla trenches lack expression of K8 and Prox1 in the taste bud progenitor cells, and gradually differentiate into an epidermal-like epithelium. We also demonstrate that taste placodes of the soft palate develop through a Pax9-dependent induction. Unexpectedly, Pax9 is dispensable for patterning, morphogenesis and maintenance of taste buds that develop in ectoderm-derived fungiform papillae. Collectively, our data reveal an endoderm-specific developmental program for the formation of taste buds and their associated papilla structures. In this pathway, Pax9 is essential to generate a pool of taste bud progenitors and to maintain their competence towards prosensory cell fate induction.

  13. The formation of endoderm-derived taste sensory organs requires a Pax9-dependent expansion of embryonic taste bud progenitor cells.

    Science.gov (United States)

    Kist, Ralf; Watson, Michelle; Crosier, Moira; Robinson, Max; Fuchs, Jennifer; Reichelt, Julia; Peters, Heiko

    2014-10-01

    In mammals, taste buds develop in different regions of the oral cavity. Small epithelial protrusions form fungiform papillae on the ectoderm-derived dorsum of the tongue and contain one or few taste buds, while taste buds in the soft palate develop without distinct papilla structures. In contrast, the endoderm-derived circumvallate and foliate papillae located at the back of the tongue contain a large number of taste buds. These taste buds cluster in deep epithelial trenches, which are generated by intercalating a period of epithelial growth between initial placode formation and conversion of epithelial cells into sensory cells. How epithelial trench formation is genetically regulated during development is largely unknown. Here we show that Pax9 acts upstream of Pax1 and Sox9 in the expanding taste progenitor field of the mouse circumvallate papilla. While a reduced number of taste buds develop in a growth-retarded circumvallate papilla of Pax1 mutant mice, its development arrests completely in Pax9-deficient mice. In addition, the Pax9 mutant circumvallate papilla trenches lack expression of K8 and Prox1 in the taste bud progenitor cells, and gradually differentiate into an epidermal-like epithelium. We also demonstrate that taste placodes of the soft palate develop through a Pax9-dependent induction. Unexpectedly, Pax9 is dispensable for patterning, morphogenesis and maintenance of taste buds that develop in ectoderm-derived fungiform papillae. Collectively, our data reveal an endoderm-specific developmental program for the formation of taste buds and their associated papilla structures. In this pathway, Pax9 is essential to generate a pool of taste bud progenitors and to maintain their competence towards prosensory cell fate induction.

  14. The Central Nervous in system Rhabdoid tumor primitive

    International Nuclear Information System (INIS)

    Manana, G.; Bernachin, J.; Waskoff, S.; Panuncio, A.

    2004-01-01

    Primitive Rhabdoid tumors of the Central Nervous system are entities of very low frequency and since 1942 is the first event observed in a total of 16,000 cases studied in the Laboratory of Neuropathology, Clinical Hospital. Until 2003 were described 118 case in the literature. The case is about the 3 years old child with no previous medical history consulted for 3 months with headaches, repeated vomiting, irritability and non specific abnormal gait. On examination is found a physical waking depression and great hydrocephalus in V I bilateral pair so is submitted to a emergency surgery. RMI CT and MRI performed reveals large frontal tumor that reaches the oval center with cystic and calcifications areas. Three days after is operates for the intraventricular tumor without post operative complications. Receive chemotherapy and the patient died 2 years later. The neuro pathological and ultrastructural study reveals a Rhabdoid malignancy brain tumor of grade IV as well as were analyzed histopathological and ultrastructural aspects of this entity

  15. Modeling discrete and rhythmic movements through motor primitives: a review.

    Science.gov (United States)

    Degallier, Sarah; Ijspeert, Auke

    2010-10-01

    Rhythmic and discrete movements are frequently considered separately in motor control, probably because different techniques are commonly used to study and model them. Yet the increasing interest in finding a comprehensive model for movement generation requires bridging the different perspectives arising from the study of those two types of movements. In this article, we consider discrete and rhythmic movements within the framework of motor primitives, i.e., of modular generation of movements. In this way we hope to gain an insight into the functional relationships between discrete and rhythmic movements and thus into a suitable representation for both of them. Within this framework we can define four possible categories of modeling for discrete and rhythmic movements depending on the required command signals and on the spinal processes involved in the generation of the movements. These categories are first discussed in terms of biological concepts such as force fields and central pattern generators and then illustrated by several mathematical models based on dynamical system theory. A discussion on the plausibility of theses models concludes the work.

  16. Primitive neuroectodermal tumor of adrenal: Clinical presentation and outcomes

    Directory of Open Access Journals (Sweden)

    Deep Dutta

    2013-01-01

    Full Text Available Primitive neuroectodermal tumor (PNET of adrenal is an extremely rare tumor of neural crest origin. A nonfunctional left adrenal mass (14.6 × 10.5 × 10.0 cm on computed tomography (CT was detected in a 40-year-old lady with abdominal pain, swelling, and left pleural effusion. She underwent left adrenalectomy and left nephrectomy with retroperitoneal resection. Histopathology revealed sheets and nest of oval tumor cells with hyperchromatic nuclei, prominent nucleoli, scanty cytoplasm, brisk mitotic activity, necrosis, lymphovascular invasion, capsular invasion, and extension to the surrounding muscles; staining positive for Mic-2 (CD-99 antigen, vimentin, synaptophysin, and Melan-A. Thoracocentesis, pleural fluid study, and pleural biopsy did not show metastasis. She responded well to vincristine, adriamycin, and cyclophosphamide followed by ifosfamide and etoposide (IE. This is the first report of adrenal peripheral PNET (pPNET from India. This report intends to highlight that pPNET should be suspected in a patient presenting with huge nonfunctional adrenal mass which may be confused with adrenocortical carcinoma.

  17. Multiple Ewing Sarcoma/Primitive Neuroectodermal Tumors in the Mediastinum

    Science.gov (United States)

    Bae, Sung Hwan; Hwang, Jung Hwa; Da Nam, Bo; Kim, Hyun Jo; Kim, Ki-Up; Kim, Dong Won; Choi, In Ho

    2016-01-01

    Abstract Ewing sarcoma/primitive neuroectodermal tumors (ES/PNET) are high-grade malignant neoplasms. These malignancies present very rare tumors of thoracopulmonary area and even rarer in the mediastinum. In our knowledge, ES/PNET presented with multiple mediastinal masses has not been reported previously. We experienced a case of a 42-year-old man presented with gradual onset of left-side pleuritic chest pain. A contrast-enhanced chest computed tomography (CT) scan showed separate 2 large heterogeneously enhancing masses in each anterior and middle mediastinum of the left hemithorax. Positron emission tomography-computed tomography (PET-CT) scan revealed high fluorodeoxyglucose (FDG) uptake in the mediastinal masses. After surgical excision for the mediastinal masses, both of the masses were diagnosed as the ES/PNET group of tumors on the histopathologic examination. The patient refused postoperative adjuvant chemotherapy and came back with local tumor recurrence and distant metastasis on 4-month follow-up after surgical resection. We report this uncommon form of ES/PNET. We are to raise awareness that this rare malignancy should be considered as a differential diagnosis of the malignant mediastinal tumors and which can be manifested as multiple masses in a patient. Understanding this rare entity of extra-skeletal ES/PNET and characteristic imaging findings can help radiologists and clinicians to approach proper diagnosis and better management for this highly malignant tumor. PMID:26886614

  18. Rapid world modeling: Fitting range data to geometric primitives

    International Nuclear Information System (INIS)

    Feddema, J.; Little, C.

    1996-01-01

    For the past seven years, Sandia National Laboratories has been active in the development of robotic systems to help remediate DOE's waste sites and decommissioned facilities. Some of these facilities have high levels of radioactivity which prevent manual clean-up. Tele-operated and autonomous robotic systems have been envisioned as the only suitable means of removing the radioactive elements. World modeling is defined as the process of creating a numerical geometric model of a real world environment or workspace. This model is often used in robotics to plan robot motions which perform a task while avoiding obstacles. In many applications where the world model does not exist ahead of time, structured lighting, laser range finders, and even acoustical sensors have been used to create three dimensional maps of the environment. These maps consist of thousands of range points which are difficult to handle and interpret. This paper presents a least squares technique for fitting range data to planar and quadric surfaces, including cylinders and ellipsoids. Once fit to these primitive surfaces, the amount of data associated with a surface is greatly reduced up to three orders of magnitude, thus allowing for more rapid handling and analysis of world data

  19. Primary Ewing Sarcoma/Primitive Neuroectodermal Tumor of the Stomach

    Directory of Open Access Journals (Sweden)

    Safi Khuri

    2016-11-01

    Full Text Available Ewing sarcoma/primitive neuroectodermal tumor (ES/PNET is a tumor of small round cells arising in skeletal tissues. These tumors rarely arise in the stomach. We present a 31-year-old healthy female patient who was admitted to our surgical ward due to upper gastrointestinal hemorrhage. Upper endoscopy revealed a large ulcerated bleeding mass originating from the lesser curvature. Biopsy revealed tumor cell immunoreactivity positive for CD99, vimentin, and Ki67 (an index of proliferation. These findings were compatible with gastric ES/PNET. The fluorescence in situ hybridization analysis result for the EWSR1 gene rearrangement (11: 22 translocation was positive. The patient refused neoadjuvant treatment and thus underwent an operation during which a mass at the lesser curvature of the stomach was found. The mass was adhering to the pancreatic tail and to the mesentery of the transverse and descending colon. Total gastrectomy, distal pancreatectomy, splenectomy, and left adrenalectomy were done. The patient refused adjuvant treatment. She is free of disease 3 years after surgery.

  20. Primitive Neuroectodermal Tumor (PNET) of the kidney: a case report

    International Nuclear Information System (INIS)

    Pomara, Giorgio; Cappello, Francesco; Cuttano, Maria G; Rappa, Francesca; Morelli, Girolamo; Mancini, Pierantonio; Selli, Cesare

    2004-01-01

    A case of Primitive Neuroectodermal Tumor (PNET) of the kidney in a 27-year-old woman is presented. Few cases are reported in the literature with a variable, nonspecific presentation and an aggressive behaviour. In our case, a radical nephrectomy with lymphadenectomy was performed and there was no residual or recurrent tumour at 24-month follow-up. The surgical specimens were formalin-fixed and paraffin embedded. The sections were stained with routinary H&E. Immunohistochemistry was performed. The immunohistochemical evaluation revealed a diffuse CD99 positivity in the cytoplasm of the neoplastic cells. Pankeratin, cytokeratin AE1/AE3, vimentin, desmin, S100, cromogranin were negative. The clinical presentation and the macroscopic aspect, together with the histological pattern, the cytological characteristic and the cellular immunophenotype addressed the diagnosis towards primary PNET of kidney. Since sometimes it is difficult to discriminate between PNET and Ewing's tumour, we reviewed the difficulties in differential diagnosis. These tumors have a common precursor but the stage of differentiation in which it is blocked is probably different. This could also explain their different biological behaviour and prognosis

  1. Primitive object love in Melanie Klein's thinking; early theoretical influences.

    Science.gov (United States)

    Likierman, M

    1993-04-01

    Melanie Klein's thinking on early object love is pivotal to her vision of development. Yet within her texts it is often enmeshed in complex formulations that obscure its full significance. A greater clarity in viewing Klein's concept of early object love is achieved through tracing some of its historical origins. The author notes that it was inspired by aspects of Ferenczi's theory, hence its similarities with the concept of 'primary love' formulated by another of Ferenczi's analysands, Michael Balint. Ferenczi's thinking on the subject formed part of a broader network of theoretical developments in the history of psychoanalytic ideas. These are shown to have origins in Freud's fluctuations between a 'passive' and a 'genital' characterisation of infantile sexuality. A dialectical tension between these two possibilities, as maintained in the Freudian texts, was partly embodied in the differing outlooks of Klein's two psychoanalysts, Abraham and Ferenczi. The author suggests that it is a mixture of their approaches that partly shaped Klein's thinking on the earliest experiences of love. After outlining these developments the author analyses the nature of early object love as it emerges from Klein's powerful, if intermittent descriptions in the texts. The analysis also tackles a textual ambiguity in Klein's formulations, showing that she explored two kinds of primitive ideal experience without explicitly differentiating them. Such differentiation is important inasmuch as it highlights negative and positive aspects of Kleinian theory at root.

  2. Social evaluation-induced amylase elevation and economic decision-making in the dictator game in humans.

    Science.gov (United States)

    Takahashi, Taiki; Ikeda, Koki; Hasegawa, Toshikazu

    2007-10-01

    Little is known regarding the relationship between social evaluation-induced neuroendocrine responses and generosity in game-theoretic situations. Previous studies demonstrated that reputation formation plays a pivotal role in prosocial behavior. This study aimed to examine the relationships between a social evaluation-induced salivary alpha-amylase (sAA) response and generosity in the dictator game. The relationship is potentially important in neuroeconomics of altruism and game theory. We assessed sAA and allocated money in the dictator game in male students with and without social evaluation. RESULTS Social evaluation-responders allocated significantly more money than controls; while there was no significant correlation between social evaluation-induced sAA elevation and the allocated money. Social evaluation significantly increases generosity in the dictator game, and individual differences in trait characteristics such as altruism and reward sensitivity may be important determinants of generosity in the dictator game task.

  3. The neural basis for writing from dictation in the temporoparietal cortex.

    Science.gov (United States)

    Roux, Franck-Emmanuel; Durand, Jean-Baptiste; Réhault, Emilie; Planton, Samuel; Draper, Louisa; Démonet, Jean-François

    2014-01-01

    Cortical electrical stimulation mapping was used to study neural substrates of the function of writing in the temporoparietal cortex. We identified the sites involved in oral language (sentence reading and naming) and writing from dictation, in order to spare these areas during removal of brain tumours in 30 patients (23 in the left, and 7 in the right hemisphere). Electrostimulation of the cortex impaired writing ability in 62 restricted cortical areas (.25 cm2). These were found in left temporoparietal lobes and were mostly located along the superior temporal gyrus (Brodmann's areas 22 and 42). Stimulation of right temporoparietal lobes in right-handed patients produced no writing impairments. However there was a high variability of location between individuals. Stimulation resulted in combined symptoms (affecting oral language and writing) in fourteen patients, whereas in eight other patients, stimulation-induced pure agraphia symptoms with no oral language disturbance in twelve of the identified areas. Each detected area affected writing in a different way. We detected the various different stages of the auditory-to-motor pathway of writing from dictation: either through comprehension of the dictated sentences (word deafness areas), lexico-semantic retrieval, or phonologic processing. In group analysis, barycentres of all different types of writing interferences reveal a hierarchical functional organization along the superior temporal gyrus from initial word recognition to lexico-semantic and phonologic processes along the ventral and the dorsal comprehension pathways, supporting the previously described auditory-to-motor process. The left posterior Sylvian region supports different aspects of writing function that are extremely specialized and localized, sometimes being segregated in a way that could account for the occurrence of pure agraphia that has long-been described in cases of damage to this region. Copyright © 2013 Elsevier Ltd. All rights reserved.

  4. Symmetry-dictated trucation: Solutions of the spherical shell model for heavy nuclei

    International Nuclear Information System (INIS)

    Guidry, M.W.

    1992-01-01

    Principles of dynamical symmetry are used to simplify the spherical shell model. The resulting symmetry-dictated truncation leads to dynamical symmetry solutions that are often in quantitative agreement with a variety of observables. Numerical calculations, including terms that break the dynamical symmetries, are shown that correspond to shell model calculations for heavy deformed nuclei. The effective residual interaction is simple, well-behaved, and can be determined from basic observables. With this approach, we intend to apply the shell model in systematic fashion to all nuclei. The implications for nuclear structure far from stability and for nuclear masses and other quantities of interest in astrophysics are discussed

  5. Enhanced Matrix Power Function for Cryptographic Primitive Construction

    Directory of Open Access Journals (Sweden)

    Eligijus Sakalauskas

    2018-02-01

    Full Text Available A new enhanced matrix power function (MPF is presented for the construction of cryptographic primitives. According to the definition in previously published papers, an MPF is an action of two matrices powering some base matrix on the left and right. The MPF inversion equations, corresponding to the MPF problem, are derived and have some structural similarity with classical multivariate quadratic (MQ problem equations. Unlike the MQ problem, the MPF problem seems to be more complicated, since its equations are not defined over the field, but are represented as left–right action of two matrices defined over the infinite near-semiring on the matrix defined over the certain infinite, additive, noncommuting semigroup. The main results are the following: (1 the proposition of infinite, nonsymmetric, and noncommuting algebraic structures for the construction of the enhanced MPF, satisfying associativity conditions, which are necessary for cryptographic applications; (2 the proof that MPF inversion is polynomially equivalent to the solution of a certain kind of generalized multivariate quadratic (MQ problem which can be reckoned as hard; (3 the estimation of the effectiveness of direct MPF value computation; and (4 the presentation of preliminary security analysis, the determination of the security parameter, and specification of its secure value. These results allow us to make a conjecture that enhanced MPF can be a candidate one-way function (OWF, since the effective (polynomial-time inversion algorithm for it is not yet known. An example of the application of the proposed MPF for the Key Agreement Protocol (KAP is presented. Since the direct MPF value is computed effectively, the proposed MPF is suitable for the realization of cryptographic protocols in devices with restricted computation resources.

  6. Isotopic and chemical variation of organic nanoglobules in primitive meteorites

    Science.gov (United States)

    de Gregorio, Bradley T.; Stroud, Rhonda M.; Nittler, Larry R.; Alexander, Conel M. O'd.; Bassim, Nabil D.; Cody, George D.; Kilcoyne, A. L. David; Sandford, Scott A.; Milam, Stefanie N.; Nuevo, Michel; Zega, Thomas J.

    2013-05-01

    Organic nanoglobules are microscopic spherical carbon-rich objects present in chondritic meteorites and other astromaterials. We performed a survey of the morphology, organic functional chemistry, and isotopic composition of 184 nanoglobules in insoluble organic matter (IOM) residues from seven primitive carbonaceous chondrites. Hollow and solid nanoglobules occur in each IOM residue, as well as globules with unusual shapes and structures. Most nanoglobules have an organic functional chemistry similar to, but slightly more carboxyl-rich than, the surrounding IOM, while a subset of nanoglobules have a distinct, highly aromatic functionality. The range of nanoglobule N isotopic compositions was similar to that of nonglobular 15N-rich hotspots in each IOM residue, but nanoglobules account for only about one third of the total 15N-rich hotspots in each sample. Furthermore, many nanoglobules in each residue contained no 15N enrichment above that of bulk IOM. No morphological indicators were found to robustly distinguish the highly aromatic nanoglobules from those that have a more IOM-like functional chemistry, or to distinguish 15N-rich nanoglobules from those that are isotopically normal. The relative abundance of aromatic nanoglobules was lower, and nanoglobule diameters were greater, in more altered meteorites, suggesting the creation/modification of IOM-like nanoglobules during parent-body processing. However, 15N-rich nanoglobules, including many with highly aromatic functional chemistry, likely reflect preaccretionary isotopic fractionation in cold molecular cloud or protostellar environments. These data indicate that no single formation mechanism can explain all of the observed characteristics of nanoglobules, and their properties are likely a result of multiple processes occurring in a variety of environments.

  7. Deep Interior: Probing the Structure of Primitive Bodies

    Science.gov (United States)

    Asphaug, Erik; Scheeres, Daniel; Safaeinili, Ali

    Deep Interior is a mature Discovery-class mission concept focused on probing the geophysical behavior of primitive bodies, from the mechanics of their exterior materials to the structures of their interiors. Its theme is to discover how small bodies work - to learn the natural origin and evolution of asteroids, comets and other primitive bodies through radar reflection tomography and through detailed observations of the local and global effects of cratering. Learning the structure and mechanical response of asteroids and comets is also a precursor to resource utilization and hazardous asteroid mitigation. Overall the mission is aligned with NASA strategic sub-goal 3C, to advance scientific knowledge of the origin and history of the solar system ... and the hazards and resources present as humans explore space. Deep Interior deploys no complex landers or sub-spacecraft; the scientific instruments are a radar and a camera. A blast cratering experiments triggered by grenades leads to a low cost seismological investigation which complements the radar investigation. A desired addition is an imaging spectrometer. The science instruments are high heritage, as are the navigation techniques for orbiting and station-keeping. The mission conducts the following investigations at one or more asteroids: Radar Reflection Tomography (RRT). The first science phase is to operate a penetrating radar during each several-month rendezvous, deployed in reflection mode in the manner of ongoing radar investigations underway by Mars Express, Mars Reconnaissance Orbiter, and Kaguya. The RRT technique (Safaeinili et al., MAPS 2002) is analogous to performing a "CAT scan" from orbit: closely sampled radar echoes are processed to yield volumetric maps of mechanical and compositional boundaries, and to measure interior dielectric properties. Deep Interior utilizes a polar orbit (or station keeping) while the asteroid spins underneath; the result is to "peel the apple" with thousands of unique

  8. MRI diagnosis of supratentorial and intraspinal primitive neuroectodermal tumors

    International Nuclear Information System (INIS)

    Liu Meili; Cui Shimin; Han Tong; Li Tao; Liu Li; Lei Jing; Qing Jingxi; Yan Xiaoling; Kong Fanming

    2004-01-01

    Objective: To analyze the MRI features of supratentorial and intraspinal primitive neuroectodermal tumors (PNET) and improve the diagnostic accuracy. Methods: MRI manifestations of 9 PNET diagnosed via operation and pathological examination were analyzed. There were 6 men and 3 women, and the mean age was 32.6 years. In all 9 cases, conventional plain MR scans were performed, including spin echo (SE), fast spin echo (FSE), and fluid attenuated inversion recovery (FLAIR) sequences. Diffusion weighted images (DWIs) and postcontrast MR images were obtained in 2 and 4 cases, respectively. Results: The 8 cases with supratentorial lesions included fronto-temporal lesion in 2 cases, occipital lesion in 2 cases, fronto-parietal lobe, parietal lobe, frontal lobe lesion in each 1 case, and posterior part of third ventricle in 1 case, and the lesion located in the thoracic spinal canal in 1 case. All the lesions were quite large in volume, and the largest one was 6.0 cm x 6.9 cm x 4.9 cm. Except for the round-like lesion in the posterior part of third ventricle, the other 7 supratentorial lesions were irregular in shape, well demarked, and often with solid consistency and slight peritumoral edema. The lesions demonstrated long T 1 and long or slightly long T 2 signal intensity in 4 cases, mixed signal intensity on T 1 WI, T 2 WI, and FLAIR images in 4 cases. Small cystic degeneration could be seen in 2 cases, hemorrhage in 4 cases, and flow void vessels in 3 cases. 3 cases demonstrated irregular ring-like enhancement and ependymal dissemination. The lesion in the thoracic canal demonstrated as a slightly enhanced soft tissue mass with adjacent bony destruction and muscle infiltration. Conclusion: MR findings of PNET are rather characteristic, but the final diagnosis relies on pathology

  9. Exploring Hardware-Based Primitives to Enhance Parallel Security Monitoring in a Novel Computing Architecture

    National Research Council Canada - National Science Library

    Mott, Stephen

    2007-01-01

    This research explores how hardware-based primitives can be implemented to perform security-related monitoring in real-time, offer better security, and increase performance compared to software-based approaches...

  10. The genomes of two key bumblebee species with primitive eusocial organization

    DEFF Research Database (Denmark)

    Sadd, Ben M.; Barribeau, Seth M.; Bloch, Guy

    2015-01-01

    BACKGROUND: The shift from solitary to social behavior is one of the major evolutionary transitions. Primitively eusocial bumblebees are uniquely placed to illuminate the evolution of highly eusocial insect societies. Bumblebees are also invaluable natural and agricultural pollinators, and there ...

  11. From primitive identity to the non-individuality of quantum objects

    Science.gov (United States)

    Arenhart, Jonas Becker; Krause, Décio

    2014-05-01

    We consider the claim by Dorato and Morganti (Grades of individuality. A pluralistic view of identity in quantum mechanics and in the sciences. Philosophical Studies, 163 (2013) 591-610) that primitive individuality should be attributed to the entities dealt with by non-relativistic quantum mechanics. There are two central ingredients in the proposal: (i) in the case of non-relativistic quantum mechanics, individuality should be taken as a primitive notion and (ii) primitive individuality is naturalistically acceptable. We argue that, strictly understood, naturalism faces difficulties in helping to provide a theory with a unique principle of individuation. We also hold that even when taken in a loose sense, naturalism does not provide any sense in which one could hold that quantum mechanics endorses primitive individuality over non-individuality. Rather, we argue that non-individuality should be preferred based on the grounds that such a view fits better the claims of the theory.

  12. Retinoic acid signaling plays a restrictive role in zebrafish primitive myelopoiesis.

    Directory of Open Access Journals (Sweden)

    Dong Liang

    Full Text Available Retinoic acid (RA is known to regulate definitive myelopoiesis but its role in vertebrate primitive myelopoiesis remains unclear. Here we report that zebrafish primitive myelopoiesis is restricted by RA in a dose dependent manner mainly before 11 hpf (hours post fertilization when anterior hemangioblasts are initiated to form. RA treatment significantly reduces expressions of anterior hemangioblast markers scl, lmo2, gata2 and etsrp in the rostral end of ALPM (anterior lateral plate mesoderm of the embryos. The result indicates that RA restricts primitive myelopoiesis by suppressing formation of anterior hemangioblasts. Analyses of ALPM formation suggest that the defective primitive myelopoiesis resulting from RA treatment before late gastrulation may be secondary to global loss of cells for ALPM fate whereas the developmental defect resulting from RA treatment during 10-11 hpf should be due to ALPM patterning shift. Overexpressions of scl and lmo2 partially rescue the block of primitive myelopoiesis in the embryos treated with 250 nM RA during 10-11 hpf, suggesting RA acts upstream of scl to control primitive myelopoiesis. However, the RA treatment blocks the increased primitive myelopoiesis caused by overexpressing gata4/6 whereas the abolished primitive myelopoiesis in gata4/5/6 depleted embryos is well rescued by 4-diethylamino-benzaldehyde, a retinal dehydrogenase inhibitor, or partially rescued by knocking down aldh1a2, the major retinal dehydrogenase gene that is responsible for RA synthesis during early development. Consistently, overexpressing gata4/6 inhibits aldh1a2 expression whereas depleting gata4/5/6 increases aldh1a2 expression. The results reveal that RA signaling acts downstream of gata4/5/6 to control primitive myelopoiesis. But, 4-diethylamino-benzaldehyde fails to rescue the defective primitive myelopoiesis in either cloche embryos or lycat morphants. Taken together, our results demonstrate that RA signaling restricts

  13. Strabismus-mediated primary archenteron invagination is uncoupled from Wnt/β-catenin-dependent endoderm cell fate specification in Nematostella vectensis (Anthozoa, Cnidaria: Implications for the evolution of gastrulation

    Directory of Open Access Journals (Sweden)

    Kumburegama Shalika

    2011-01-01

    Full Text Available Abstract Background Gastrulation is a uniquely metazoan character, and its genesis was arguably the key step that enabled the remarkable diversification within this clade. The process of gastrulation involves two tightly coupled events during embryogenesis of most metazoans. Morphogenesis produces a distinct internal epithelial layer in the embryo, and this epithelium becomes segregated as an endoderm/endomesodermal germ layer through the activation of a specific gene regulatory program. The developmental mechanisms that induced archenteron formation and led to the segregation of germ layers during metazoan evolution are unknown. But an increased understanding of development in early diverging taxa at the base of the metazoan tree may provide insights into the origins of these developmental mechanisms. Results In the anthozoan cnidarian Nematostella vectensis, initial archenteron formation begins with bottle cell-induced buckling of the blastula epithelium at the animal pole. Here, we show that bottle cell formation and initial gut invagination in Nematostella requires NvStrabismus (NvStbm, a maternally-expressed core component of the Wnt/Planar Cell Polarity (PCP pathway. The NvStbm protein is localized to the animal pole of the zygote, remains asymmetrically expressed through the cleavage stages, and becomes restricted to the apical side of invaginating bottle cells at the blastopore. Antisense morpholino-mediated NvStbm-knockdown blocks bottle cell formation and initial archenteron invagination, but it has no effect on Wnt/ß-catenin signaling-mediated endoderm cell fate specification. Conversely, selectively blocking Wnt/ß-catenin signaling inhibits endoderm cell fate specification but does not affect bottle cell formation and initial archenteron invagination. Conclusions Our results demonstrate that Wnt/PCP-mediated initial archenteron invagination can be uncoupled from Wnt/ß-catenin-mediated endoderm cell fate specification in

  14. Une tumeur neuroectodermique primitive périphérique à localisation ...

    African Journals Online (AJOL)

    Les tumeurs neuro-ectodermiques primitives ou sarcome d'Ewing sont classiquement des néoplasmes se développant aux dépends des tissus mous et des os. Les tumeurs neuro-ectodermiques primitives gastriques (pPNETs) sont extrêmement rares. Nous nous proposons, à travers le cas d'un patient, opéré pour une ...

  15. Driving Style Analysis Using Primitive Driving Patterns With Bayesian Nonparametric Approaches

    OpenAIRE

    Wang, Wenshuo; Xi, Junqiang; Zhao, Ding

    2017-01-01

    Analysis and recognition of driving styles are profoundly important to intelligent transportation and vehicle calibration. This paper presents a novel driving style analysis framework using the primitive driving patterns learned from naturalistic driving data. In order to achieve this, first, a Bayesian nonparametric learning method based on a hidden semi-Markov model (HSMM) is introduced to extract primitive driving patterns from time series driving data without prior knowledge of the number...

  16. A mutli-technique search for the most primitive CO chondrites

    Science.gov (United States)

    Alexander, C. M. O'D.; Greenwood, R. C.; Bowden, R.; Gibson, J. M.; Howard, K. T.; Franchi, I. A.

    2018-01-01

    As part of a study to identify the most primitive COs and to look for weakly altered CMs amongst the COs, we have conducted a multi-technique study of 16 Antarctic meteorites that had been classified as primitive COs. For this study, we have determined: (1) the bulk H, C and N abundances and isotopes, (2) bulk O isotopic compositions, (3) bulk modal mineralogies, and (4) for some selected samples the abundances and compositions of their insoluble organic matter (IOM). Two of the 16 meteorites do appear to be CMs - BUC 10943 seems to be a fairly typical CM, while MIL 090073 has probably been heated. Of the COs, DOM 08006 appears to be the most primitive CO identified to date and is quite distinct from the other members of its pairing group. The other COs fall into two groups that are less primitive than DOM 08006 and ALH 77307, the previously most primitive CO. The first group is composed of members of the DOM 08004 pairing group, except DOM 08006. The second group is composed of meteorites belonging to the MIL 03377 and MIL 07099 pairing groups. These two pairing groups should probably be combined. There is a dichotomy in the bulk O isotopes between the primitive (all Antarctic finds) and the more metamorphosed COs (mostly falls). This dichotomy can only partly be explained by the terrestrial weathering experienced by the primitive Antarctic samples. It seems that the more equilibrated samples interacted to a greater extent with 16O-poor material, probably water, than the more primitive meteorites.

  17. From Windfall Sharing to Property Ownership: Prosocial Personality Traits in Giving and Taking Dictator Games

    Directory of Open Access Journals (Sweden)

    Kun Zhao

    2018-05-01

    Full Text Available The dictator game is a well-known task measuring prosocial preferences, in which one person divides a fixed amount of windfall money with a recipient. A key factor in real-world transfers of wealth is the concept of property ownership and consequently the related acts of giving and taking. Using a variation of the traditional dictator game (N = 256, we examined whether individual differences under different game frames corresponded with prosocial personality traits from the Big Five (politeness, compassion and HEXACO (Honesty-Humility, Emotionality, eXtraversion, Agreeableness, Conscientiousness, Openness to Experience (honesty-humility, agreeableness models. In the Big Five model, the effects of prosocial personality traits were generally stronger and more consistent for taking than for giving, in line with a “do-no-harm” explanation, whereby prosocial individuals felt less entitled to and less willing to infringe on the endowments of others. In contrast, HEXACO honesty-humility predicted allocations across both frames, consistent with its broad association with fair-mindedness, and providing further evidence of its role in allocations of wealth more generally. These findings highlight the utility of integrating personality psychology with behavioral economics, in which the discriminant validity across prosocial traits can shed light on the distinct motivations underpinning social decisions.

  18. Proportion offered in the Dictator and Ultimatum Games decreases with amount and social distance.

    Science.gov (United States)

    Bechler, Christopher; Green, Leonard; Myerson, Joel

    2015-06-01

    Behavior in both the Dictator Game and the Ultimatum Game is of special interest because proposers often violate the predictions of normative economic theory: On average, offers in both games are higher than what would be considered income-maximizing. In the present study, the initial amount provided to the proposer and the social distance between the proposer and the respondent were both varied across a wide range, and the effects of these manipulations on offers in the Dictator Game and the Ultimatum Game were examined in a broad sample of participants recruited via MTurk. Although the amount offered was consistently higher in the Ultimatum Game, the proportion of the amount offered decreased as the size of the initial amount increased in both games. Moreover, the proportion offered also decreased as a function of the social distance between the proposer and the responder. The present results extend our knowledge of the determinants of proposers' behavior in two-person economic games and emphasize the importance of social distance and the amount of money at stake as factors that affect people's economic decisions. Copyright © 2015 Elsevier B.V. All rights reserved.

  19. Attentional strategic control over nonlexical and lexical processing in written spelling to dictation in adults.

    Science.gov (United States)

    Bonin, Patrick; Collay, Sandra; Fayol, Michel; Méot, Alain

    2005-01-01

    We conducted four experiments to investigate whether adults can exert attentional strategic control over nonlexical and lexical processing in written spelling to dictation. In Experiment 1, regular and irregular words were produced either in a nonword context (regular and irregular nonwords) or in a word context (high-frequency regular and irregular words), whereas in Experiment 2, the same set of words was produced either in a regular nonword or in an irregular low-frequency word context. Experiment 3 was a replication of Experiment 2 but with increased manipulation of the context. In Experiment 4, participants had to produce either under time pressure or in response to standard written spelling instructions. Regularity effects were found in all the experiments, but their size was not reliably affected by manipulations intended to increase or decrease reliance on nonlexical processing. More particularly, the results from Experiment 4 show that adults can speed up the initialization of their writing responses to a substantial degree without altering regularity effects on either latencies or spelling errors. Our findings suggest that, although adults are able to generate an internal deadline criterion of when to initialize the writing responses, nonlexical processing is a mandatory process that is not subject to attentional strategic control in written spelling to dictation.

  20. Kosovo, the beginning and end of the adventure of a dictator in Europe

    Directory of Open Access Journals (Sweden)

    Xhavit Sadrijaj

    2016-07-01

    Full Text Available When desires are not based in reality, the result is the only one that can be expected from such desires. In such games winning is actually called losing. That also happened with the consuming desires of the late dictator in Europe, Milošević. The permanent Yugoslav president Tito, was known for his philosophy: “We decline what is not ours; ours we will relinquish not”. Although it was not like that, this philosophy had its success. It kept the morale of strength and the existence of a state of over 30 nations who lived in it and who remained steadfast and unbeaten throughout the Cold War. With Tito's death his country died too, altogether with the philosophy. The fact that it really was just philosophy was shown several years later, when in the absence of a successor to Tito, but also through new anticommunist movements in the world, the state collapsed becoming involved in war and chaos that was manifested by bloody tragedies of very large dimensions. Of course all this tragedy was preceded by Serbian chauvinist passions and desires which were planned for a century in all forms, and which were implemented by a dictator who also will remain in history as such, Slobodan Milošević and his clique. This executioner chose Kosovo as the most appropriate level for its establishment in the peaks of power and certainly had not imagined then that was also his end.

  1. Spatiotemporal mechanical variation reveals critical role for rho kinase during primitive streak morphogenesis.

    Science.gov (United States)

    Henkels, Julia; Oh, Jaeho; Xu, Wenwei; Owen, Drew; Sulchek, Todd; Zamir, Evan

    2013-02-01

    Large-scale morphogenetic movements during early embryo development are driven by complex changes in biochemical and biophysical factors. Current models for amniote primitive streak morphogenesis and gastrulation take into account numerous genetic pathways but largely ignore the role of mechanical forces. Here, we used atomic force microscopy (AFM) to obtain for the first time precise biomechanical properties of the early avian embryo. Our data reveal that the primitive streak is significantly stiffer than neighboring regions of the epiblast, and that it is stiffer than the pre-primitive streak epiblast. To test our hypothesis that these changes in mechanical properties are due to a localized increase of actomyosin contractility, we inhibited actomyosin contractility via the Rho kinase (ROCK) pathway using the small-molecule inhibitor Y-27632. Our results using several different assays show the following: (1) primitive streak formation was blocked; (2) the time-dependent increase in primitive streak stiffness was abolished; and (3) convergence of epiblast cells to the midline was inhibited. Taken together, our data suggest that actomyosin contractility is necessary for primitive streak morphogenesis, and specifically, ROCK plays a critical role. To better understand the underlying mechanisms of this fundamental process, future models should account for the findings presented in this study.

  2. Evaluating structural pattern recognition for handwritten math via primitive label graphs

    Science.gov (United States)

    Zanibbi, Richard; Mouchère, Harold; Viard-Gaudin, Christian

    2013-01-01

    Currently, structural pattern recognizer evaluations compare graphs of detected structure to target structures (i.e. ground truth) using recognition rates, recall and precision for object segmentation, classification and relationships. In document recognition, these target objects (e.g. symbols) are frequently comprised of multiple primitives (e.g. connected components, or strokes for online handwritten data), but current metrics do not characterize errors at the primitive level, from which object-level structure is obtained. Primitive label graphs are directed graphs defined over primitives and primitive pairs. We define new metrics obtained by Hamming distances over label graphs, which allow classification, segmentation and parsing errors to be characterized separately, or using a single measure. Recall and precision for detected objects may also be computed directly from label graphs. We illustrate the new metrics by comparing a new primitive-level evaluation to the symbol-level evaluation performed for the CROHME 2012 handwritten math recognition competition. A Python-based set of utilities for evaluating, visualizing and translating label graphs is publicly available.

  3. In search of a primitive ontology for relativistic quantum field theory

    Energy Technology Data Exchange (ETDEWEB)

    Lam, Vincent [University of Lausanne, CH-1015 Lausanne (Switzerland)

    2014-07-01

    There is a recently much discussed approach to the ontology of quantum mechanics according to which the theory is ultimately about entities in 3-dimensional space and their temporal evolution. Such an ontology postulating from the start matter localized in usual physical space or spacetime, by contrast to an abstract high-dimensional space such as the configuration space of wave function realism, is called primitive ontology in the recent literature on the topic and finds its roots in Bell's notion of local beables. The main motivation for a primitive ontology lies in its explanatory power: the primitive ontology allows for a direct account of the behaviour and properties of familiar macroscopic objects. In this context, it is natural to look for a primitive ontology for relativistic quantum field theory (RQFT). The aim of this talk is to critically discuss this interpretative move within RQFT, in particular with respect to the foundational issue of the existence of unitarily inequivalent representations. Indeed the proposed primitive ontologies for RQFT rely either on a Fock space representation or a wave functional representation, which are strictly speaking only unambiguously available for free systems in flat spacetime. As a consequence, it is argued that these primitive ontologies constitute only effective ontologies and are hardly satisfying as a fundamental ontology for RQFT.

  4. The Impact of Morphological Awareness on Word Reading and Dictation in Chinese Early Adolescent Readers With and Without Dyslexia.

    Science.gov (United States)

    Kalindi, Sylvia Chanda; Chung, Kevin Kien Hoa

    2018-01-01

    This study investigated the role of morphological awareness in understanding Chinese word reading and dictation among Chinese-speaking adolescent readers in Hong Kong as well as the cognitive-linguistic profile of early adolescent readers with dyslexia. Fifty-four readers with dyslexia in Grades 5 and 6 were compared with 54 chronological age-matched (CA) typical readers on the following measures of cognitive-linguistic and literacy skills: morphological awareness, phonological awareness, visual-orthographic knowledge, rapid naming, vocabulary knowledge, verbal short-term memory (STM), Chinese word reading, and dictation (or spelling). The results indicated that early adolescent readers with dyslexia performed less well than the typical readers on all cognitive-linguistic and literacy measures except the phonological measures. Both groups' scores showed substantial correlations between morphological awareness and Chinese word reading and dictation. Visual-orthographic knowledge and rapid naming were also associated with dictation in early adolescent readers with and without dyslexia, respectively. Moderated multiple regression analyses further revealed that morphological awareness and rapid naming explained unique variance in word reading and dictation for the readers with dyslexia and typical readers separately after controlling readers' age and group effect. These results highlight the potential importance of morphological awareness and rapid naming in Chinese word reading and writing in Chinese early adolescents' literacy development and impairment.

  5. What dictates which ion, I- or Br-, mediates the growth of cubic Pd nanocrystals?

    Science.gov (United States)

    Wang, Ze-Hong; Wu, Ya-Jiao; Xue, Huan-Huan; Zhou, Lin-Nan; Geng, Wen-Chao; Yi, Hai-Bo; Li, Yong-Jun

    2018-04-25

    Cubic Pd nanocrystals (CPNCs) as one of typical nanostructures are generally fabricated using I- or Br- as capping ions. However, which ion, I- or Br-, exclusively mediates the growth of CPNCs in a given reaction system is not well understood. Herein, regardless of I- or Br- as the capping ion, we successfully achieved CPNCs in the same reaction system simply by adjusting the pH. Based on the Finke-Watzky kinetic model, an increase in pH accelerates the overall reduction rate of Pd2+, and the formation of CPNCs only occurs over the range of specific solution reduction rate constants (k1). This kinetically illuminates that the reduction rate of Pd2+ is the physicochemical parameter that determines which ion, I- or Br-, dictates the growth of CPNCs. Also, density functional theory (DFT) calculations further elucidate the dependence of the reduction rate of Pd2+ on pH and the configuration of the activated Pd2+ complex.

  6. How cancer cells dictate their microenvironment: present roles of extracellular vesicles.

    Science.gov (United States)

    Naito, Yutaka; Yoshioka, Yusuke; Yamamoto, Yusuke; Ochiya, Takahiro

    2017-02-01

    Intercellular communication plays an important role in cancer initiation and progression through secretory molecules, including growth factors and cytokines. Recent advances have revealed that small membrane vesicles, termed extracellular vesicles (EVs), served as a regulatory agent in the intercellular communication of cancer. EVs enable the transfer of functional molecules, including proteins, mRNA and microRNAs (miRNAs), into recipient cells. Cancer cells utilize EVs to dictate the unique phenotype of surrounding cells, thereby promoting cancer progression. Against such "education" by cancer cells, non-tumoral cells suppress cancer initiation and progression via EVs. Therefore, researchers consider EVs to be important cues to clarify the molecular mechanisms of cancer biology. Understanding the functions of EVs in cancer progression is an important aspect of cancer biology that has not been previously elucidated. In this review, we summarize experimental data that indicate the pivotal roles of EVs in cancer progression.

  7. Cell Origin Dictates Programming of Resident versus Recruited Macrophages during Acute Lung Injury.

    Science.gov (United States)

    Mould, Kara J; Barthel, Lea; Mohning, Michael P; Thomas, Stacey M; McCubbrey, Alexandra L; Danhorn, Thomas; Leach, Sonia M; Fingerlin, Tasha E; O'Connor, Brian P; Reisz, Julie A; D'Alessandro, Angelo; Bratton, Donna L; Jakubzick, Claudia V; Janssen, William J

    2017-09-01

    Two populations of alveolar macrophages (AMs) coexist in the inflamed lung: resident AMs that arise during embryogenesis, and recruited AMs that originate postnatally from circulating monocytes. The objective of this study was to determine whether origin or environment dictates the transcriptional, metabolic, and functional programming of these two ontologically distinct populations over the time course of acute inflammation. RNA sequencing demonstrated marked transcriptional differences between resident and recruited AMs affecting three main areas: proliferation, inflammatory signaling, and metabolism. Functional assays and metabolomic studies confirmed these differences and demonstrated that resident AMs proliferate locally and are governed by increased tricarboxylic acid cycle and amino acid metabolism. Conversely, recruited AMs produce inflammatory cytokines in association with increased glycolytic and arginine metabolism. Collectively, the data show that even though they coexist in the same environment, inflammatory macrophage subsets have distinct immunometabolic programs and perform specialized functions during inflammation that are associated with their cellular origin.

  8. The RNA polymerase dictates ORF1 requirement and timing of LINE and SINE retrotransposition.

    Directory of Open Access Journals (Sweden)

    Emily N Kroutter

    2009-04-01

    Full Text Available Mobile elements comprise close to one half of the mass of the human genome. Only LINE-1 (L1, an autonomous non-Long Terminal Repeat (LTR retrotransposon, and its non-autonomous partners-such as the retropseudogenes, SVA, and the SINE, Alu-are currently active human retroelements. Experimental evidence shows that Alu retrotransposition depends on L1 ORF2 protein, which has led to the presumption that LINEs and SINEs share the same basic insertional mechanism. Our data demonstrate clear differences in the time required to generate insertions between marked Alu and L1 elements. In our tissue culture system, the process of L1 insertion requires close to 48 hours. In contrast to the RNA pol II-driven L1, we find that pol III transcribed elements (Alu, the rodent SINE B2, and the 7SL, U6 and hY sequences can generate inserts within 24 hours or less. Our analyses demonstrate that the observed retrotransposition timing does not dictate insertion rate and is independent of the type of reporter cassette utilized. The additional time requirement by L1 cannot be directly attributed to differences in transcription, transcript length, splicing processes, ORF2 protein production, or the ability of functional ORF2p to reach the nucleus. However, the insertion rate of a marked Alu transcript drastically drops when driven by an RNA pol II promoter (CMV and the retrotransposition timing parallels that of L1. Furthermore, the "pol II Alu transcript" behaves like the processed pseudogenes in our retrotransposition assay, requiring supplementation with L1 ORF1p in addition to ORF2p. We postulate that the observed differences in retrotransposition kinetics of these elements are dictated by the type of RNA polymerase generating the transcript. We present a model that highlights the critical differences of LINE and SINE transcripts that likely define their retrotransposition timing.

  9. Defined three-dimensional culture conditions mediate efficient induction of definitive endoderm lineage from human umbilical cord Wharton's jelly mesenchymal stem cells.

    Science.gov (United States)

    Al Madhoun, Ashraf; Ali, Hamad; AlKandari, Sarah; Atizado, Valerie Lopez; Akhter, Nadeem; Al-Mulla, Fahd; Atari, Maher

    2016-11-16

    Wharton's jelly-derived mesenchymal stem cells (WJ-MSCs) are gaining increasing interest as an alternative source of stem cells for regenerative medicine applications. Definitive endoderm (DE) specification is a prerequisite for the development of vital organs such as liver and pancreas. Hence, efficient induction of the DE lineage from stem cells is crucial for subsequent generation of clinically relevant cell types. Here we present a defined 3D differentiation protocol of WJ-MSCs into DE cells. WJ-MSCs were cultured in suspension to generate spheroids, about 1500 cells each, for 7 days. The serum-free differentiation media contained specific growth factors, cytokines, and small molecules that specifically regulate signaling pathways including sonic hedgehog, bone morphogenetic protein, Activin/Wnt, and Notch. We obtained more than 85 % DE cells as shown with FACS analysis using antibodies directed against the DE marker CXCR4. In addition, biochemical and molecular analysis of bona-fide DE markers revealed a time-course induction of Sox17, CXCR4, and FoxA2. Focused PCR-based array also indicated a specific induction into the DE lineage. In this study, we report an efficient serum-free protocol to differentiate WJ-MSCs into DE cells utilizing 3D spheroid formation. Our approach might aid in the development of new protocols to obtain DE-derivative lineages including liver-like and pancreatic insulin-producing cells.

  10. Embryonic cholesterol esterification is regulated by a cyclic AMP-dependent pathway in yolk sac membrane-derived endodermal epithelial cells.

    Directory of Open Access Journals (Sweden)

    Siou-Huei Wang

    Full Text Available During avian embryonic development, endodermal epithelial cells (EECs absorb yolk through the yolk sac membrane. Sterol O-acyltransferase (SOAT is important for esterification and yolk lipid utilization during development. Because the major enzyme for yolk sac membrane cholesteryl ester synthesis is SOAT1, we cloned the avian SOAT1 promoter and elucidated the cellular functions of SOAT1. Treatments with either glucagon, isobutylmethylxanthine (IBMX, an adenylate cyclase activator (forskolin, a cAMP analog (dibutyryl-cAMP, or a low glucose concentration all increased SOAT1 mRNA accumulation in EECs from Japanese quail, suggesting that SOAT1 is regulated by nutrients and hormones through a cAMP-dependent pathway. Activity of protein kinase A (PKA was increased by IBMX, whereas co-treatment with the PKA inhibitor, H89 negated the increase in PKA activity. Cyclic AMP-induced EECs had greater cholesterol esterification than untreated EECs. By promoter deletion and point-mutation, the cAMP-response element (-349 to -341 bp was identified as critical in mediating transcription of SOAT1. In conclusion, expression of SOAT1 was regulated by a cAMP-dependent pathway and factors that increase PKA will increase SOAT1 to improve the utilization of lipids in the EECs and potentially modify embryonic growth.

  11. A case of the persistence of the primitive hypoglossal artery with an enlarged hypoglossal canal

    International Nuclear Information System (INIS)

    Tomura, Noriaki; Inugami, Atsushi; Uemura, Kazuo; Asakura, Ken

    1987-01-01

    A case of the persistence of the primitive hypoglossal artery is reported, with a roentgenographic demonstration of the enlarged hypoglossal canal. A 63-year-old man was admitted to this hospital as a result of a malfunction of the ventriculo-peritoneal shunt. At the age of 51, the patient had been operated on in this hospital for an aneurysm of the right middle cerebral artery; at that time, the right primitive hypoglossal artery was observed on right carotid angiograms. On the day following admission, bilateral retrograde vertebral angiography was performed and the right persistent primitive hypoglossal artery was recognized again. Stenvers views of the skull demonstrated an enlargement of the hypoglossal canal, with a smooth sclerotic rim. High-resolution computed tomography with a contrast infusion delineated the right primitive hypoglossal artery through the enlarged hypoglossal canal. The diameter of the enlarged right hypoglossal canal and that of the left one were found to be 8 mm and 4 mm respectively on the CT. When an enlargement of the hypoglossal canal with a sclerotic rim is observed, the persistence of the primitive hypoglossal artery should be considered in the differential diagnosis. (author)

  12. Physically Unclonable Cryptographic Primitives by Chemical Vapor Deposition of Layered MoS2.

    Science.gov (United States)

    Alharbi, Abdullah; Armstrong, Darren; Alharbi, Somayah; Shahrjerdi, Davood

    2017-12-26

    Physically unclonable cryptographic primitives are promising for securing the rapidly growing number of electronic devices. Here, we introduce physically unclonable primitives from layered molybdenum disulfide (MoS 2 ) by leveraging the natural randomness of their island growth during chemical vapor deposition (CVD). We synthesize a MoS 2 monolayer film covered with speckles of multilayer islands, where the growth process is engineered for an optimal speckle density. Using the Clark-Evans test, we confirm that the distribution of islands on the film exhibits complete spatial randomness, hence indicating the growth of multilayer speckles is a spatial Poisson process. Such a property is highly desirable for constructing unpredictable cryptographic primitives. The security primitive is an array of 2048 pixels fabricated from this film. The complex structure of the pixels makes the physical duplication of the array impossible (i.e., physically unclonable). A unique optical response is generated by applying an optical stimulus to the structure. The basis for this unique response is the dependence of the photoemission on the number of MoS 2 layers, which by design is random throughout the film. Using a threshold value for the photoemission, we convert the optical response into binary cryptographic keys. We show that the proper selection of this threshold is crucial for maximizing combination randomness and that the optimal value of the threshold is linked directly to the growth process. This study reveals an opportunity for generating robust and versatile security primitives from layered transition metal dichalcogenides.

  13. Intrapartum synthetic oxytocin reduce the expression of primitive reflexes associated with breastfeeding.

    Science.gov (United States)

    Marín Gabriel, Miguel A; Olza Fernández, Ibone; Malalana Martínez, Ana M; González Armengod, Carmen; Costarelli, Valeria; Millán Santos, Isabel; Fernández-Cañadas Morillo, Aurora; Pérez Riveiro, Pilar; López Sánchez, Francisco; García Murillo, Lourdes

    2015-05-01

    Several synthetic peptide manipulations during the time surrounding birth can alter the specific neurohormonal status in the newborn brain. This study is aimed at assessing whether intrapartum oxytocin administration has any effect on primitive neonatal reflexes and determining whether such an effect is dose-dependent. A cohort prospective study was conducted at a tertiary hospital. Mother-infant dyads who received intrapartum oxytocin (n=53) were compared with mother-infant dyads who did not receive intrapartum oxytocin (n=45). Primitive neonatal reflexes (endogenous, antigravity, motor, and rhythmic reflexes) were quantified by analyzing videotaped breastfeeding sessions in a biological nurturing position. Two observers blind to the group assignment and the oxytocin dose analyzed the videotapes and assesed the newborn's state of consciousness according to the Brazelton scale. The release of all rhythmic reflexes (p=0.01), the antigravity reflex (p=0.04), and total primitive neonatal reflexes (p=0.02) in the group exposed to oxytocin was lower than in the group not exposed to oxytocin. No correlations were observed between the dose of oxytocin administered and the percentage of primitive neonatal reflexes released (r=0.03; p=0.82). Intrapartum oxytocin administration might inhibit the expression of several primitive neonatal reflexes associated with breastfeeding. This correlation does not seem to be dose-dependent.

  14. Writing to dictation and handwriting performance among Chinese children with dyslexia: relationships with orthographic knowledge and perceptual-motor skills.

    Science.gov (United States)

    Cheng-Lai, Alice; Li-Tsang, Cecilia W P; Chan, Alan H L; Lo, Amy G W

    2013-10-01

    The purpose of this study was to investigate the relationships between writing to dictation, handwriting, orthographic, and perceptual-motor skills among Chinese children with dyslexia. A cross-sectional design was used. A total of 45 third graders with dyslexia were assessed. Results of stepwise multiple regression models showed that Chinese character naming was the only predictor associated with word dictation (β=.32); handwriting speed was related to deficits in rapid automatic naming (β=-.36) and saccadic efficiency (β=-.29), and visual-motor integration predicted both of the number of characters exceeded grid (β=-.41) and variability of character size (β=-.38). The findings provided support to a multi-stage working memory model of writing for explaining the possible underlying mechanism of writing to dictation and handwriting difficulties. Copyright © 2013 Elsevier Ltd. All rights reserved.

  15. Global and exponential attractors of the three dimensional viscous primitive equations of large-scale moist atmosphere

    OpenAIRE

    You, Bo; Li, Fang

    2016-01-01

    This paper is concerned with the long-time behavior of solutions for the three dimensional viscous primitive equations of large-scale moist atmosphere. We prove the existence of a global attractor for the three dimensional viscous primitive equations of large-scale moist atmosphere by asymptotic a priori estimate and construct an exponential attractor by using the smoothing property of the semigroup generated by the three dimensional viscous primitive equations of large-scale moist atmosphere...

  16. Interaction à deux joueurs en informatique quantique : primitives cryptographiques et complexité en requêtes

    OpenAIRE

    Magnin , Loïck

    2011-01-01

    This dissertation studies two different aspects of two-player interaction in the model of quantum communication and quantum computation.First, we study two cryptographic primitives, that are used as basic blocks to construct sophisticated cryptographic protocols between two players, e.g. identification protocols.The first primitive is ``quantum bit commitment''. This primitive cannot be done in an unconditionally secure way. However, security can be obtained by restraining the power of the tw...

  17. Cave men: stone tools, Victorian science, and the 'primitive mind' of deep time.

    Science.gov (United States)

    Pettitt, Paul B; White, Mark J

    2011-03-20

    Palaeoanthropology, the study of the evolution of humanity, arose in the nineteenth century. Excavations in Europe uncovered a series of archaeological sediments which provided proof that the antiquity of human life on Earth was far longer than the biblical six thousand years, and by the 1880s authors had constructed a basic paradigm of what 'primitive' human life was like. Here we examine the development of Victorian palaeoanthropology for what it reveals of the development of notions of cognitive evolution. It seems that Victorian specialists rarely addressed cognitive evolution explicitly, although several assumptions were generally made that arose from preconceptions derived from contemporary 'primitive' peoples. We identify three main phases of development of notions of the primitive mind in the period.

  18. Caspase-9 has a nonapoptotic function in Xenopus embryonic primitive blood formation.

    Science.gov (United States)

    Tran, Hong Thi; Fransen, Mathias; Dimitrakopoulou, Dionysia; Van Imschoot, Griet; Willemarck, Nicolas; Vleminckx, Kris

    2017-07-15

    Caspases constitute a family of cysteine proteases centrally involved in programmed cell death, which is an integral part of normal embryonic and fetal development. However, it has become clear that specific caspases also have functions independent of cell death. In order to identify novel apoptotic and nonapoptotic developmental caspase functions, we designed and transgenically integrated novel fluorescent caspase reporter constructs in developing Xenopus embryos and tadpoles. This model organism has an external development, allowing direct and continuous monitoring. These studies uncovered a nonapoptotic role for the initiator caspase-9 in primitive blood formation. Functional experiments further corroborated that caspase-9, but possibly not the executioners caspase-3 and caspase-7, are required for primitive erythropoiesis in the early embryo. These data reveal a novel nonapoptotic function for the initiator caspase-9 and, for the first time, implicate nonapoptotic caspase activity in primitive blood formation. © 2017. Published by The Company of Biologists Ltd.

  19. Missing relationship of moyamoya and persistent primitive artery in Europeans. Another distinctive feature or artifact?

    Science.gov (United States)

    Wenz, Holger; Wenz, Ralf; Förster, Alex; Fontana, Johann; Kerl, Hans Ulrich; Groden, Christoph; Scharf, Johann

    2015-11-01

    Previous studies found higher incidence of persistent primitive arteries in Asian moyamoya (MM) patients than in the general population, which was thought to be a characteristic trait of the MM entity in general. We analyzed incidence of persistent primitive arteries and demographics of patients with European MM treated in one single center. First, we compared our large dataset to existing literature and second, we raised the question whether European MM demonstrates similar high prevalence of persistent primitive arteries as it was previously presented within Asian MM. All European MM on whom revascularization surgery was performed from 1999 to 2013 were included. Demographics and associated diseases were obtained by retrospective chart review. Two independent readers evaluated 122 MM angiograms to determine the occurrence of persistent primitive arteries as well as the Suzuki score. We identified 112 cases with MM disease, 10 with MM syndrome. Mean age at time of diagnosis was 38.2 (range 6-64 years); a peak incidence in early childhood was not observed. Ninety (73.8%) were women, associated systemic diseases were found in four patients. Seven cases (5.7%) presented with unilaterally affected vessels. The majority of patients (71; 58.2%) were graded Suzuki Score 3. One 14-year-old boy with moyamoya presented with a primitive trigeminal artery (0.89%). We did not find a bimodal age distribution, but only a second peak during adulthood. Unlike previous studies on Asian moyamoya patients, our collective does not exhibit a higher prevalence of persistent primitive arteries than the normal population.

  20. A mutli-technique search for the most primitive CO chondrites

    OpenAIRE

    Alexander, C.M.O'D.; Greenwood, R.C.; Bowden, R.; Gibson, J.M.; Howard, K.T.; Franchi, I.A.

    2018-01-01

    As part of a study to identify the most primitive COs and to look for weakly altered CMs amongst the COs, we have conducted a multi-technique study of 16 Antarctic meteorites that had been classified as primitive COs. For this study, we have determined: (1) the bulk H, C and N abundances and isotopes, (2) bulk O isotopic compositions, (3) bulk modal mineralogies, and (4) for some selected samples the abundances and compositions of their insoluble organic matter (IOM). Two of the 16 meteorites...

  1. Primary dorsal spine primitive neuroectodermal tumor in an adult patient: Case report and literature review

    Directory of Open Access Journals (Sweden)

    Satyashiva Munjal

    2017-01-01

    Full Text Available Primary spinal primitive neuroectodermal tumor (psPNET is a rare entity with few cases reported in literature. We report a case of a 50-year-old female who presented to us with paraplegia and was diagnosed with extradural dorsal spine psPNET. The diagnosis was not suspected at presentation or on radiology but was established on histopathological examination. It is important to distinguish it from central nervous system primitive neuroectodermal tumors and from other spinal tumors since it follows a different clinical course and therapeutic outcome.

  2. A Synoptic of Software Implementation for Shift Registers Based on 16th Degree Primitive Polynomials

    Directory of Open Access Journals (Sweden)

    Mirella Amelia Mioc

    2016-08-01

    Full Text Available Almost all of the major applications in the specific Fields of Communication used a well-known device called Linear Feedback Shift Register. Usually LFSR functions in a Galois Field GF(2n, meaning that all the operations are done with arithmetic modulo n degree Irreducible  and especially  Primitive Polynomials. Storing data in Galois Fields allows effective and manageable manipulation, mainly in computer cryptographic applications. The analysis of functioning for Primitive Polynomials of 16th degree shows that almost all the obtained results are in the same time distribution.

  3. Efficient conservative ADER schemes based on WENO reconstruction and space-time predictor in primitive variables

    Science.gov (United States)

    Zanotti, Olindo; Dumbser, Michael

    2016-01-01

    We present a new version of conservative ADER-WENO finite volume schemes, in which both the high order spatial reconstruction as well as the time evolution of the reconstruction polynomials in the local space-time predictor stage are performed in primitive variables, rather than in conserved ones. To obtain a conservative method, the underlying finite volume scheme is still written in terms of the cell averages of the conserved quantities. Therefore, our new approach performs the spatial WENO reconstruction twice: the first WENO reconstruction is carried out on the known cell averages of the conservative variables. The WENO polynomials are then used at the cell centers to compute point values of the conserved variables, which are subsequently converted into point values of the primitive variables. This is the only place where the conversion from conservative to primitive variables is needed in the new scheme. Then, a second WENO reconstruction is performed on the point values of the primitive variables to obtain piecewise high order reconstruction polynomials of the primitive variables. The reconstruction polynomials are subsequently evolved in time with a novel space-time finite element predictor that is directly applied to the governing PDE written in primitive form. The resulting space-time polynomials of the primitive variables can then be directly used as input for the numerical fluxes at the cell boundaries in the underlying conservative finite volume scheme. Hence, the number of necessary conversions from the conserved to the primitive variables is reduced to just one single conversion at each cell center. We have verified the validity of the new approach over a wide range of hyperbolic systems, including the classical Euler equations of gas dynamics, the special relativistic hydrodynamics (RHD) and ideal magnetohydrodynamics (RMHD) equations, as well as the Baer-Nunziato model for compressible two-phase flows. In all cases we have noticed that the new ADER

  4. A PICKED SAMPLE TO THE FOOTPRINT OF PRIMITIVE INDIVIDUALISM OF RECENT DATE ART: BASQUIAT

    Directory of Open Access Journals (Sweden)

    Ozgur TOSUN

    2015-09-01

    Full Text Available Through the culturel history, meaning of art and art object have been queried and these researchs have emerged thesis and antithesis. Fundamentaly, this article aim to comparison interaction and/or conflict with mathematical rationalist art and primitive/heuristical/romantic art. In this context, effects of primitive and experssive art to the nowadays’ art perception are examined to envolve out of Basquiat and neo expressionism. Entailment of expressive art in contemporary art is researched for answers for questions in terms of cultural and genetic heritage of art and instinctive origins of making art object.

  5. To bend or not to bend – are heteroatom interactions within conjugated molecules effective in dictating conformation and planarity?

    KAUST Repository

    Conboy, Gary; Spencer, Howard J.; Angioni, Enrico; Kanibolotsky, Alexander L.; Findlay, Neil J.; Coles, Simon J.; Wilson, Claire; Pitak, Mateusz B.; Risko, Chad; Coropceanu, Veaceslav; Bredas, Jean-Luc; Skabara, Peter J.

    2016-01-01

    We consider the roles of heteroatoms (mainly nitrogen, the halogens and the chalcogens) in dictating the conformation of linear conjugated molecules and polymers through non-covalent intramolecular interactions. Whilst hydrogen bonding is a competitive and sometimes more influential interaction, we provide unambiguous evidence that heteroatoms are able to determine the conformation of such materials with reasonable predictability.

  6. Anonymity versus privacy in the dictator game: revealing donor decisions to recipients does not substantially impact donor behavior.

    Directory of Open Access Journals (Sweden)

    Jeffrey Winking

    Full Text Available Anonymity is often offered in economic experiments in order to eliminate observer effects and induce behavior that would be exhibited under private circumstances. However, anonymity differs from privacy in that interactants are only unaware of each others' identities, while having full knowledge of each others' actions. Such situations are rare outside the laboratory and anonymity might not meet the requirements of some participants to psychologically engage as if their actions were private. In order to explore the impact of a lack of privacy on prosocial behaviors, I expand on a study reported in Dana et al. (2006 in which recipients were left unaware of the Dictator Game and given donations as "bonuses" to their show-up fees for other tasks. In the current study, I explore whether differences between a private Dictator Game (sensu Dana et al. (2006 and a standard anonymous one are due to a desire by dictators to avoid shame or to pursue prestige. Participants of a Dictator Game were randomly assigned to one of four categories-one in which the recipient knew of (1 any donation by an anonymous donor (including zero donations, (2 nothing at all, (3 only zero donations, and (4 and only non-zero donations. The results suggest that a lack of privacy increases the shame that selfish-acting participants experience, but that removing such a cost has only minimal effects on actual behavior.

  7. Children's Sharing Behavior in Mini-Dictator Games: The Role of In-Group Favoritism and Theory of Mind

    Science.gov (United States)

    Yu, Jing; Zhu, Liqi; Leslie, Alan M.

    2016-01-01

    This study investigated the motivational and social-cognitive foundations (i.e., inequality aversion, in-group bias, and theory of mind) that underlie the development of sharing behavior among 3- to 9-year-old Chinese children (N = 122). Each child played two mini-dictator games against an in-group member (friend) and an out-group member…

  8. A positive effect of flowers rather than eye images in a large-scale, cross-cultural dictator game.

    Science.gov (United States)

    Raihani, Nichola J; Bshary, Redouan

    2012-09-07

    People often consider how their behaviour will be viewed by others, and may cooperate to avoid gaining a bad reputation. Sensitivity to reputation may be elicited by subtle social cues of being watched: previous studies have shown that people behave more cooperatively when they see images of eyes rather than control images. Here, we tested whether eye images enhance cooperation in a dictator game, using the online labour market Amazon Mechanical Turk (AMT). In contrast to our predictions and the results of most previous studies, dictators gave away more money when they saw images of flowers rather than eye images. Donations in response to eye images were not significantly different to donations under control treatments. Dictator donations varied significantly across cultures but there was no systematic variation in responses to different image types across cultures. Unlike most previous studies, players interacting via AMT may feel truly anonymous when making decisions and, as such, may not respond to subtle social cues of being watched. Nevertheless, dictators gave away similar amounts as in previous studies, so anonymity did not erase helpfulness. We suggest that eye images might only promote cooperative behaviour in relatively public settings and that people may ignore these cues when they know their behaviour is truly anonymous.

  9. Effects of Dictation, Speech to Text, and Handwriting on the Written Composition of Elementary School English Language Learners

    Science.gov (United States)

    Arcon, Nina; Klein, Perry D.; Dombroski, Jill D.

    2017-01-01

    Previous research has shown that both dictation and speech-to-text (STT) software can increase the quality of writing for native English speakers. The purpose of this study was to investigate the effect of these modalities on the written composition and cognitive load of elementary school English language learners (ELLs). In a within-subjects…

  10. The selector gene Pax7 dictates alternate pituitary cell fates through its pioneer action on chromatin remodeling

    NARCIS (Netherlands)

    Budry, L.; Balsalobre, A.; Gauthier, Y.; Khetchoumian, K.; L'Honore, A.; Vallette-Kasic, S.; Brue, T; Figarella-Branger, D.; Meij, B.P.; Drouin, J.

    2012-01-01

    Genes Dev. 2012 Oct 15;26(20):2299-310. doi: 10.1101/gad.200436.112. The selector gene Pax7 dictates alternate pituitary cell fates through its pioneer action on chromatin remodeling. Budry L, Balsalobre A, Gauthier Y, Khetchoumian K, L'honoré A, Vallette S, Brue T, Figarella-Branger D, Meij B,

  11. To bend or not to bend – are heteroatom interactions within conjugated molecules effective in dictating conformation and planarity?

    KAUST Repository

    Conboy, Gary

    2016-04-26

    We consider the roles of heteroatoms (mainly nitrogen, the halogens and the chalcogens) in dictating the conformation of linear conjugated molecules and polymers through non-covalent intramolecular interactions. Whilst hydrogen bonding is a competitive and sometimes more influential interaction, we provide unambiguous evidence that heteroatoms are able to determine the conformation of such materials with reasonable predictability.

  12. Effects of Dicto-Comp and Dictation on the Writing Skill of Female Adult Iranian EFL Learners

    Science.gov (United States)

    Adel, Rahil; Hashemian, Mahmood

    2015-01-01

    This study was an attempt to clarify and remind L2 learners/teachers of 2 kinds of writing: dicto-comp and dictation. We explored the effect of controlled writing on the accuracy of the writing of adult Iranian EFL learners. Prior to the study, the homogeneity of 30 adult EFL learners was checked through an OPT test. Thirty participants were…

  13. Efficient programming of human eye conjunctiva-derived induced pluripotent stem (ECiPS) cells into definitive endoderm-like cells.

    Science.gov (United States)

    Massumi, Mohammad; Hoveizi, Elham; Baktash, Parvaneh; Hooti, Abdollah; Ghazizadeh, Leili; Nadri, Samad; Pourasgari, Farzaneh; Hajarizadeh, Athena; Soleimani, Masoud; Nabiuni, Mohammad; Khorramizadeh, Mohammad R

    2014-03-10

    Due to pluripotency of induced pluripotent stem (iPS) cells, and the lack of immunological incompatibility and ethical issues, iPS cells have been considered as an invaluable cell source for future cell replacement therapy. This study was aimed first at establishment of novel iPS cells, ECiPS, which directly reprogrammed from human Eye Conjunctiva-derived Mesenchymal Stem Cells (EC-MSCs); second, comparing the inductive effects of Wnt3a/Activin A biomolecules to IDE1 small molecule in derivation of definitive endoderm (DE) from the ECiPS cells. To that end, first, the EC-MSCs were transduced by SOKM-expressing lentiviruses and characterized for endogenous expression of embryonic markers Then the established ECiPS cells were induced to DE formation by Wnt3a/Activin A or IDE1. Quantification of GSC, Sox17 and Foxa2 expression, as DE-specific markers, in both mRNA and protein levels revealed that induction of ECiPS cells by either Wnt3a/Activin A or IDE1 could enhance the expression level of the genes; however the levels of increase were higher in Wnt3a/Activin A induced ECiPS-EBs than IDE1 induced cells. Furthermore, the flow cytometry analyses showed no synergistic effect between Activin A and Wnt3a to derive DE-like cells from ECiPS cells. The comparative findings suggest that although both Wnt3a/Activin A signaling and IDE1 molecule could be used for differentiation of iPS into DE cells, the DE-inducing effect of Wnt3a/Activin A was statistically higher than IDE1. Copyright © 2014 Elsevier Inc. All rights reserved.

  14. Dual emission behavior of phenyleneethynylene gold(I) complexes dictated by intersystem crossing: a theoretical perspective.

    Science.gov (United States)

    Wang, Li; Li, Yuanyuan; Zhang, Yanxin; He, Hongqing; Zhang, Jinglai

    2015-02-25

    In commonly studied gold(I) complexes with oligo (o-, p-, or m-phenyleneethynylene) (PE) ligands, an intriguing photophysical behavior is dual emission composed of fluorescence from S1 and phosphorescence from T1 which is dictated by effective intersystem crossing (ISC) process. In order to explore the salient photodynamics of such oligo-PE gold(I) complexes effectively, we have deliberately chosen three model complexes, namely, Ph-C≡C-Au(PMe3) (1a') and Ph-C≡C-(1,m)C6H4-C≡C-Au(PMe3) (m=4, 2a'; m=3, 3a') in place of the real system. Firstly, electronic structure methods based on DFT and TD-DFT are utilized to perform optimization calculations for the ground- and lowest-lying excited states, respectively. Next, basic photophysical properties including absorption and emission spectra are investigated by TD-DFT under the optimized geometries. Besides, on the basis of the electronic spectra herein, we succeed in searching for surface intersections as the minima on the seam of singlet-triplet surface crossings (SCs) at the CASSCF level of theory. By integration of the results available, the process of delayed fluorescence of triplet-triplet annihilation (TTA) and phosphorescence was displayed in detail with SCs playing the lead in monitoring the ISC. Copyright © 2014 Elsevier B.V. All rights reserved.

  15. Distinct Functional Domains of Ubc9 Dictate Cell Survival and Resistance to Genotoxic Stress

    Science.gov (United States)

    van Waardenburg, Robert C. A. M.; Duda, David M.; Lancaster, Cynthia S.; Schulman, Brenda A.; Bjornsti, Mary-Ann

    2006-01-01

    Covalent modification with SUMO alters protein function, intracellular localization, or protein-protein interactions. Target recognition is determined, in part, by the SUMO E2 enzyme, Ubc9, while Siz/Pias E3 ligases may facilitate select interactions by acting as substrate adaptors. A yeast conditional Ubc9P123L mutant was viable at 36°C yet exhibited enhanced sensitivity to DNA damage. To define functional domains in Ubc9 that dictate cellular responses to genotoxic stress versus those necessary for cell viability, a 1.75-Å structure of yeast Ubc9 that demonstrated considerable conservation of backbone architecture with human Ubc9 was solved. Nevertheless, differences in side chain geometry/charge guided the design of human/yeast chimeras, where swapping domains implicated in (i) binding residues within substrates that flank canonical SUMOylation sites, (ii) interactions with the RanBP2 E3 ligase, and (iii) binding of the heterodimeric E1 and SUMO had distinct effects on cell growth and resistance to DNA-damaging agents. Our findings establish a functional interaction between N-terminal and substrate-binding domains of Ubc9 and distinguish the activities of E3 ligases Siz1 and Siz2 in regulating cellular responses to genotoxic stress. PMID:16782883

  16. Colon cancer stem cells dictate tumor growth and resist cell death by production of interleukin-4.

    Science.gov (United States)

    Todaro, Matilde; Alea, Mileidys Perez; Di Stefano, Anna B; Cammareri, Patrizia; Vermeulen, Louis; Iovino, Flora; Tripodo, Claudio; Russo, Antonio; Gulotta, Gaspare; Medema, Jan Paul; Stassi, Giorgio

    2007-10-11

    A novel paradigm in tumor biology suggests that cancer growth is driven by stem-like cells within a tumor. Here, we describe the identification and characterization of such cells from colon carcinomas using the stem cell marker CD133 that accounts around 2% of the cells in human colon cancer. The CD133(+) cells grow in vitro as undifferentiated tumor spheroids, and they are both necessary and sufficient to initiate tumor growth in immunodeficient mice. Xenografts resemble the original human tumor maintaining the rare subpopulation of tumorigenic CD133(+) cells. Further analysis revealed that the CD133(+) cells produce and utilize IL-4 to protect themselves from apoptosis. Consistently, treatment with IL-4Ralpha antagonist or anti-IL-4 neutralizing antibody strongly enhances the antitumor efficacy of standard chemotherapeutic drugs through selective sensitization of CD133(+) cells. Our data suggest that colon tumor growth is dictated by stem-like cells that are treatment resistant due to the autocrine production of IL-4.

  17. The interplay between sharing behavior and beliefs about others in children during dictator games.

    Science.gov (United States)

    Santamaría-García, Hernando; González-Gadea, María Luz; Di Tella, Rafael; Ibáñez, Agustín; Sigman, Mariano

    2018-02-01

    Previous studies in adults demonstrated that beliefs and sharing decisions in social scenarios are closely related. However, to date, little is known about the development of this relationship in children. By using a modified dictator game, we assessed sharing behavior and beliefs about others in children between 3 and 12 years old. We performed four studies (N = 376) aimed to assess whether decisions were related to beliefs (Studies 1 and 2) and whether information about the recipient's forced sharing behavior would shape decisions and beliefs (Studies 3 and 4). Results of Studies 1 and 2 showed that beliefs about others' generosity were related to children's sharing behavior. In Studies 3 and 4, we found that only children older than 9 years shared more pieces of candy when they knew that the recipient would be forced to share (cooperative context) than when they knew that the recipient would be forced not to share (noncooperative context). Besides, children older than 6 years did not modify their beliefs about others' generosity according to these social contexts. These results suggest that normative or preconceived beliefs about the functioning of the social world may guide social behavior in children. Copyright © 2017 Elsevier Inc. All rights reserved.

  18. Theory of Mind and General Intelligence in Dictator and Ultimatum Games

    Directory of Open Access Journals (Sweden)

    Hannes Lang

    2018-03-01

    Full Text Available Decreasing social sensitivity (i.e., the ability of a person to perceive, understand, and respect the feelings and viewpoints of others, has been shown to facilitate selfish behavior. This is not only true for exogenous changes in social sensitivity, but also for social sensitivity influenced by someone’s social cognition. In this analysis, we examined one measure of social cognition, namely a person’s Theory of Mind (ToM, to examine differences in decision-making in standard non-strategic and strategic environments (dictator and ultimatum games. We found that participants with higher ToM gave a greater share in the non-strategic environment. In the ultimatum game, however, ToM showed no correlation with the offers of the ultimators. Instead, we found that general intelligence scores—measured by the Wonderlic test—shared a negative, albeit weak, correlation with the amount offered in the ultimatum game. Thus, we find that lower social cognition is an important explanatory variable for selfish behavior in a non-strategic environment, while general intelligence shares some correlation in a strategic environment. Similar to the change in social sensitivity created by a specific game design, social sensitivity influenced by individual personality traits can influence behavior in non-strategic environments.

  19. Social dilemma cooperation (unlike Dictator Game giving) is intuitive for men as well as women.

    Science.gov (United States)

    Rand, David G

    2017-11-01

    Does intuition favor prosociality, or does prosocial behavior require deliberative self-control? The Social Heuristics Hypothesis (SHH) stipulates that intuition favors typically advantageous behavior - but which behavior is typically advantageous depends on both the individual and the context. For example, non-zero-sum cooperation (e.g. in social dilemmas like the Prisoner's Dilemma) typically pays off because of the opportunity for reciprocity. Conversely, reciprocity does not promote zero-sum cash transfers (e.g. in the Dictator Game, DG). Instead, DG giving can be long-run advantageous because of reputation concerns: social norms often require such behavior of women but not men. Thus, the SHH predicts that intuition will favor social dilemma cooperation regardless of gender, but only favor DG giving among women. Here I present meta-analytic evidence in support of this prediction. In 31 studies examining social dilemma cooperation (N=13,447), I find that promoting intuition increases cooperation to a similar extent for both men and women. This stands in contrast to the results from 22 DG studies (analyzed in Rand et al., 2016) where intuition promotes giving among women but not men. Furthermore, I show using meta-regression that the interaction between gender and intuition is significantly larger in the DG compared to the cooperation games. Thus, I find clear evidence that the role of intuition and deliberation varies across both setting and individual as predicted by the SHH.

  20. Dictator Perpetuus: Julius Caesar--did he have seizures? If so, what was the etiology?

    Science.gov (United States)

    Hughes, John R

    2004-10-01

    The "Dictator Perpetuus" of the Roman Empire, the great Julius Caesar, was not the one for whom the well-known cesarean operation was named; instead, this term is derived from a Latin word meaning "to cut." Caesar likely had epilepsy on the basis of four attacks that were probably complex partial seizures: (1) while listening to an oration by Cicero, (2) in the Senate while being offered the Emperor's Crown, and in military campaigns, (3) near Thapsus (North Africa) and (4) Corduba (Spain). Also, it is possible that he had absence attacks as a child and as a teenager. His son, Caesarion, by Queen Cleopatra, likely had seizures as a child, but the evidence is only suggestive. His great-great-great grandnephews Caligula and Britannicus also had seizures. The etiology of these seizures in this Julio-Claudian family was most likely through inheritance, with the possibility of sudden unexpected death in epilepsy (SUDEP) in his great grandfather and also his father. Our best evidence comes from the ancient sources of Suetonius, Plutarch, Pliny, and Appianus.

  1. Developing students' listening metacognitive strategies using online videotext self-dictation-generation learning activity

    Directory of Open Access Journals (Sweden)

    Ching Chang

    2014-03-01

    Full Text Available The study is based on the use of a flexible learning framework to help students improve information processes underlying strategy instruction in EFL listening. By exploiting the online videotext self-dictation-generation (video-SDG learning activity implemented on the YouTube caption manager platform, the learning cycle was emphasized to promote metacognitive listening development. Two theories were used to guide the online video-SDG learning activity: a student question-generation method and a metacognitive listening training model in a second language (L2. The study investigated how college students in the online video-SDG activity enhanced the use of listening strategies by developing metacognitive listening skills. With emphasis on the metacognitive instructional process, students could promote their listening comprehension of advertisement videos (AVs. Forty-eight students were recruited to participate in the study. Through data collected from the online learning platform, questionnaires, a focus-group interview, and pre- and post- achievement tests, the results revealed that the online video-SDG learning activity could effectively engage students in reflecting upon their perceptions of specific problems countered, listening strategy usages, and strategic knowledge exploited in the metacognitive instructional process. The importance of employing cost-effective online video-SGD learning activities is worthy of consideration in developing students’ metacognitive listening knowledge for enhancing EFL listening strategy instruction.

  2. A new and primitive retrobursal planarian from Australian fresh waters (Platyhelminthes, Turbellaria, Tricladida)

    NARCIS (Netherlands)

    Ball, Ian R.

    1977-01-01

    A primitive freshwater planarian, Eviella hynesae gen. et sp. nov. is described from Australia. It is characterized by its lack of eyes and pigment, possession of caudally branched oviducts, and fully fused testes. Although a primary bursa is absent, its function being taken over by the modified

  3. Growth and sedimentation of dust grains in the primitive solar nebular

    International Nuclear Information System (INIS)

    Battaglia, A.

    1987-01-01

    Formation of the planets in the solar system is envisioned to occur via a gravitational instability in a thin layer of dust located at the midplane of the primitive solar nebula. The break-up of the dust layer gives rise to seed plants (planetesimals) that, through successive collisions, eventually form the present-day planets. This thesis addresses the problem of the formation of the dust layer, beginning with a configuration in which the dust particles are uniformly mixed with the nebula's turbulent gas. To describe the properties of turbulence in the primitive solar nebula, models by Canuto et al. (1987) and by Cabot et al. (1987) are used. The available results concerning calculation of the velocity of particles embedded in a turbulent fluid were found to be unsatisfactory; therefore, a new formalism was developed to express the latter quantity in terms of the properties of the turbulence in the fluid. Following the space-time evolution of the grains, formalism was developed that simulates the simultaneous processes of collisions and sedimentation of the dust grains in the primitive solar nebula. It is concluded that, for the model of the primitive solar nebula considered, the formation of a dust layer at midplane is very unlikely

  4. A direct Primitive Variable Recovery Scheme for hyperbolic conservative equations: The case of relativistic hydrodynamics.

    Science.gov (United States)

    Aguayo-Ortiz, A; Mendoza, S; Olvera, D

    2018-01-01

    In this article we develop a Primitive Variable Recovery Scheme (PVRS) to solve any system of coupled differential conservative equations. This method obtains directly the primitive variables applying the chain rule to the time term of the conservative equations. With this, a traditional finite volume method for the flux is applied in order avoid violation of both, the entropy and "Rankine-Hugoniot" jump conditions. The time evolution is then computed using a forward finite difference scheme. This numerical technique evades the recovery of the primitive vector by solving an algebraic system of equations as it is often used and so, it generalises standard techniques to solve these kind of coupled systems. The article is presented bearing in mind special relativistic hydrodynamic numerical schemes with an added pedagogical view in the appendix section in order to easily comprehend the PVRS. We present the convergence of the method for standard shock-tube problems of special relativistic hydrodynamics and a graphical visualisation of the errors using the fluctuations of the numerical values with respect to exact analytic solutions. The PVRS circumvents the sometimes arduous computation that arises from standard numerical methods techniques, which obtain the desired primitive vector solution through an algebraic polynomial of the charges.

  5. Farey Statistics in Time n^{2/3} and Counting Primitive Lattice Points in Polygons

    OpenAIRE

    Patrascu, Mihai

    2007-01-01

    We present algorithms for computing ranks and order statistics in the Farey sequence, taking time O (n^{2/3}). This improves on the recent algorithms of Pawlewicz [European Symp. Alg. 2007], running in time O (n^{3/4}). We also initiate the study of a more general algorithmic problem: counting primitive lattice points in planar shapes.

  6. Pediatric Primitive Neuroectodermal Tumors of the Central Nervous System Differentially Express Granzyme Inhibitors

    NARCIS (Netherlands)

    Vermeulen, Jeroen F; van Hecke, Wim; Spliet, Wim G M; Villacorta Hidalgo, José; Fisch, Paul; Broekhuizen, Roel; Bovenschen, Niels

    2016-01-01

    BACKGROUND: Central nervous system (CNS) primitive neuroectodermal tumors (PNETs) are malignant primary brain tumors that occur in young infants. Using current standard therapy, up to 80% of the children still dies from recurrent disease. Cellular immunotherapy might be key to improve overall

  7. On the small time asymptotics of 3D stochastic primitive equations

    OpenAIRE

    Dong, Zhao; Zhang, Rangrang

    2017-01-01

    In this paper, we establish a small time large deviation principle for the strong solution of 3D stochastic primitive equations driven by multiplicative noise. Both the small noise and the small, but highly nonlinear, unbounded nonlinear terms should be taken into consideration.

  8. Capture, learning, and classification of upper extremity movement primitives in healthy controls and stroke patients.

    Science.gov (United States)

    Guerra, Jorge; Uddin, Jasim; Nilsen, Dawn; Mclnerney, James; Fadoo, Ammarah; Omofuma, Isirame B; Hughes, Shatif; Agrawal, Sunil; Allen, Peter; Schambra, Heidi M

    2017-07-01

    There currently exist no practical tools to identify functional movements in the upper extremities (UEs). This absence has limited the precise therapeutic dosing of patients recovering from stroke. In this proof-of-principle study, we aimed to develop an accurate approach for classifying UE functional movement primitives, which comprise functional movements. Data were generated from inertial measurement units (IMUs) placed on upper body segments of older healthy individuals and chronic stroke patients. Subjects performed activities commonly trained during rehabilitation after stroke. Data processing involved the use of a sliding window to obtain statistical descriptors, and resulting features were processed by a Hidden Markov Model (HMM). The likelihoods of the states, resulting from the HMM, were segmented by a second sliding window and their averages were calculated. The final predictions were mapped to human functional movement primitives using a Logistic Regression algorithm. Algorithm performance was assessed with a leave-one-out analysis, which determined its sensitivity, specificity, and positive and negative predictive values for all classified primitives. In healthy control and stroke participants, our approach identified functional movement primitives embedded in training activities with, on average, 80% precision. This approach may support functional movement dosing in stroke rehabilitation.

  9. Identification of novel biomarkers in pediatric primitive neuroectodermal tumors and ependymomas by proteome-wide analysis

    NARCIS (Netherlands)

    de Bont, Judith M.; den Boer, Monique L.; Kros, Johan M.; Passier, Monique M. C. J.; Reddinglus, Roel E.; Smitt, Peter A. E. Sillevis; Luider, Theo M.; Pieters, Rob

    The aim of this study was to identify aberrantly expressed proteins in pediatric primitive neuroectodermal tumors (PNETs) and ependymornas. Tumor tissue of 29 PNET and 12 ependymoma patients was subjected to 2-dimensional difference gel electrophoresis. Gel analysis resulted in 79 protein spots

  10. the reception of the deuteronomic social law in the primitive church

    African Journals Online (AJOL)

    of the Primitive Church's social and ecclesiological (self-)understanding, this study highlights ... have been written by Moses as well, the Book of Deuteronomy presents itself overall as a .... to reform society reached their limits when they became economically, socially and ..... sins of adultery and prostitution. In light of these ...

  11. Primitive Liquid Water of the Solar System in an Aqueous Altered Carbonaceous Chondrite

    Science.gov (United States)

    Tsuchiyama, A.; Miyake, A.; Kitayama, A.; Matsuno, J.; Takeuchi, A.; Uesugi, K.; Suzuki, Y.; Nakano, T.; Zolensky, M. E.

    2016-01-01

    Non-destructive 3D observations of the aqueous altered CM chondrite Sutter's Mill using scanning imaging x-ray microscopy (SIXM) showed that some of calcite and enstatite grains contain two-phase inclusion, which is most probably composed of liquid water and bubbles. This water should be primitive water responsible for aqueous alteration in an asteroid in the early solar system.

  12. Primitivity and weak distributivity in near rings and matrix near rings

    International Nuclear Information System (INIS)

    Abbasi, S.J.

    1993-08-01

    This paper shows the structure of matrix near ring constructed over a weakly distributive and primative near ring. It is proved that a weakly distributive primitive near ring is a ring and the matrix near rings constructed over it is also a bag. (author). 14 refs

  13. Fermat’s ‘primitive solutions’ and some arithmetic of elliptic curves

    NARCIS (Netherlands)

    Top, Jaap

    1993-01-01

    In his work on Diophantine equations of the form y2=ax4+bx3+cx2+dx+e, Fermat introduced the notion of primitive solutions. In this expository note we intend to interpret this notion more geometrically, and explain what it means in terms of the arithmetic of elliptic curves. The specific equation

  14. Cohesion between two clay lamellae: From Primitive Model to Full Molecular Simulation

    International Nuclear Information System (INIS)

    Carrier, Benoit; Vandamme, Matthieu; Pellenq, Roland; Van Damme, Henri

    2012-01-01

    Document available in extended abstract form only. The objective of this work is to investigate the range of validity of various models to describe accurately the cohesion between two charged clay lamellae. These models, in order of increasing complexity, are the Derjaguin-Landau-Verwey-Overbeek (DLVO) theory, the primitive model, the explicit solvent primitive model and the full molecular model. We aim at providing a clear picture of which physical mechanisms play a significant role for various interlayer spacings, surface charges and cationic charges. The up-scaling of the mechanical properties starting from the lamellar microstructure of a smectite is usually performed within the framework of the DLVO theory. In this case, the interaction between two charged lamellae with cations between them is the sum of the repulsive double layer electrostatic interaction and of the attractive Van der Waals interaction. However, the Primitive Model shows that concentration fluctuations of counter-ions can generate a strongly attractive ionic correlation force. The Primitive Model is a Monte-Carlo simulation of hydrated counter-ions between two infinite charges surfaces and the water is implicitly modeled by scaling all electrostatic interactions by the dielectric permittivity of bulk water. Nevertheless, for very small inter-layer spacings (1 nm), molecular simulations and experiments show that water is organized in a layered structure and does not behave like bulk water. Therefore, we investigate the role of the solvent in the cohesion of clay lamellae. For this purpose, we use a modified version of the original Primitive Model in which the solvent is modeled by point-dipoles: This model is called the Explicit Solvent Primitive Model. We consider four different systems: A Na + -montmorillonite, a Ca 2+ -montmorillonite, a Na + -vermiculite, a Ca 2+ -vermiculite. The vermiculite layers are twice as charged as the montmorillonite layers. We use a full molecular model as a

  15. New hybrid voxelized/analytical primitive in Monte Carlo simulations for medical applications

    International Nuclear Information System (INIS)

    Bert, Julien; Lemaréchal, Yannick; Visvikis, Dimitris

    2016-01-01

    Monte Carlo simulations (MCS) applied in particle physics play a key role in medical imaging and particle therapy. In such simulations, particles are transported through voxelized phantoms derived from predominantly patient CT images. However, such voxelized object representation limits the incorporation of fine elements, such as artificial implants from CAD modeling or anatomical and functional details extracted from other imaging modalities. In this work we propose a new hYbrid Voxelized/ANalytical primitive (YVAN) that combines both voxelized and analytical object descriptions within the same MCS, without the need to simultaneously run two parallel simulations, which is the current gold standard methodology. Given that YVAN is simply a new primitive object, it does not require any modifications on the underlying MC navigation code. The new proposed primitive was assessed through a first simple MCS. Results from the YVAN primitive were compared against an MCS using a pure analytical geometry and the layer mass geometry concept. A perfect agreement was found between these simulations, leading to the conclusion that the new hybrid primitive is able to accurately and efficiently handle phantoms defined by a mixture of voxelized and analytical objects. In addition, two application-based evaluation studies in coronary angiography and intra-operative radiotherapy showed that the use of YVAN was 6.5% and 12.2% faster than the layered mass geometry method, respectively, without any associated loss of accuracy. However, the simplification advantages and differences in computational time improvements obtained with YVAN depend on the relative proportion of the analytical and voxelized structures used in the simulation as well as the size and number of triangles used in the description of the analytical object meshes. (paper)

  16. New hybrid voxelized/analytical primitive in Monte Carlo simulations for medical applications.

    Science.gov (United States)

    Bert, Julien; Lemaréchal, Yannick; Visvikis, Dimitris

    2016-05-07

    Monte Carlo simulations (MCS) applied in particle physics play a key role in medical imaging and particle therapy. In such simulations, particles are transported through voxelized phantoms derived from predominantly patient CT images. However, such voxelized object representation limits the incorporation of fine elements, such as artificial implants from CAD modeling or anatomical and functional details extracted from other imaging modalities. In this work we propose a new hYbrid Voxelized/ANalytical primitive (YVAN) that combines both voxelized and analytical object descriptions within the same MCS, without the need to simultaneously run two parallel simulations, which is the current gold standard methodology. Given that YVAN is simply a new primitive object, it does not require any modifications on the underlying MC navigation code. The new proposed primitive was assessed through a first simple MCS. Results from the YVAN primitive were compared against an MCS using a pure analytical geometry and the layer mass geometry concept. A perfect agreement was found between these simulations, leading to the conclusion that the new hybrid primitive is able to accurately and efficiently handle phantoms defined by a mixture of voxelized and analytical objects. In addition, two application-based evaluation studies in coronary angiography and intra-operative radiotherapy showed that the use of YVAN was 6.5% and 12.2% faster than the layered mass geometry method, respectively, without any associated loss of accuracy. However, the simplification advantages and differences in computational time improvements obtained with YVAN depend on the relative proportion of the analytical and voxelized structures used in the simulation as well as the size and number of triangles used in the description of the analytical object meshes.

  17. Modelling 3D spatial objects in a geo-DBMS using a 3D primitive

    Science.gov (United States)

    Arens, Călin; Stoter, Jantien; van Oosterom, Peter

    2005-03-01

    There is a growing interest in modelling the world in three dimensions, both in applications and in science. At the same time, geographical information systems are changing into integrated architecture in which administrative and spatial data are maintained in one environment. It is for this reason that mainstream Data Base Management Systems (DBMSs) have implemented spatial data types according to the 'Simple Feature Specifications for SQL', described by the OpenGeospatial Consortium. However, these specifications are 2D, as indeed are the implementations in DBMSs. At the Section GIS Technology of TU Delft, research has been carried out in which a 3D primitive was implemented in a DBMS (Oracle Spatial). To explore the possibilities and complications, a fairly simple 3D primitive was chosen to start with: a polyhedron. In the future the study will be extended with more complex primitives, the ultimate aim being to build 3D models with features closer to the real world. Besides the data structure, a validation function was developed to check the geometric accuracy of the data. Rules for validation were established and translated into prototype implementations with the aid of literature. In order to manipulate the data, a list of useful 3D functions was specified. Most of these were translated into algorithms, which were implemented in the DBMS. The algorithms for these functions were obtained from the relevant literature. The research also comprised a comparative performance test on spatial indexing in 2D and 3D, using an R-tree. Finally, existing software was used to visualize 3D objects structured with the implemented 3D primitive. This research is a first attempt to implement a true 3D primitive in a DBMS. Future research will focus on extending and improving the implementations and on optimizing maintenance and query of 3D objects in DBMSs.

  18. Learned parametrized dynamic movement primitives with shared synergies for controlling robotic and musculoskeletal systems

    Directory of Open Access Journals (Sweden)

    Elmar eRückert

    2013-10-01

    Full Text Available A salient feature of human motor skill learning is the ability to exploitsimilarities across related tasks.In biological motor control, it has been hypothesized that muscle synergies,coherent activations of groups of muscles, allow for exploiting shared knowledge.Recent studies have shown that a rich set of complex motor skills can be generated bya combination of a small number of muscle synergies.In robotics, dynamic movement primitives are commonlyused for motor skill learning. This machine learning approach implements a stable attractor systemthat facilitates learning and it can be used in high-dimensional continuous spaces. However, it does not allow for reusing shared knowledge, i.e. for each task an individual set of parameters has to be learned.We propose a novel movement primitive representationthat employs parametrized basis functions, which combines the benefits of muscle synergiesand dynamic movement primitives. For each task asuperposition of synergies modulates a stable attractor system.This approach leads to a compact representation of multiple motor skills andat the same time enables efficient learning in high-dimensional continuous systems.The movement representation supports discrete and rhythmic movements andin particular includes the dynamic movement primitive approach as a special case.We demonstrate the feasibility of the movement representation in three multi-task learning simulated scenarios.First, the characteristics of the proposed representation are illustrated in a point-mass task.Second, in complex humanoid walking experiments,multiple walking patterns with different step heights are learned robustly and efficiently.Finally, in a multi-directional reaching task simulated with a musculoskeletal modelof the human arm, we show how the proposed movement primitives can be used tolearn appropriate muscle excitation patterns and to generalize effectively to new reaching skills.

  19. Self-assembly of cationic multidomain peptide hydrogels: supramolecular nanostructure and rheological properties dictate antimicrobial activity

    Science.gov (United States)

    Jiang, Linhai; Xu, Dawei; Sellati, Timothy J.; Dong, He

    2015-11-01

    Hydrogels are an important class of biomaterials that have been widely utilized for a variety of biomedical/medical applications. The biological performance of hydrogels, particularly those used as wound dressing could be greatly advanced if imbued with inherent antimicrobial activity capable of staving off colonization of the wound site by opportunistic bacterial pathogens. Possessing such antimicrobial properties would also protect the hydrogel itself from being adversely affected by microbial attachment to its surface. We have previously demonstrated the broad-spectrum antimicrobial activity of supramolecular assemblies of cationic multi-domain peptides (MDPs) in solution. Here, we extend the 1-D soluble supramolecular assembly to 3-D hydrogels to investigate the effect of the supramolecular nanostructure and its rheological properties on the antimicrobial activity of self-assembled hydrogels. Among designed MDPs, the bactericidal activity of peptide hydrogels was found to follow an opposite trend to that in solution. Improved antimicrobial activity of self-assembled peptide hydrogels is dictated by the combined effect of supramolecular surface chemistry and storage modulus of the bulk materials, rather than the ability of individual peptides/peptide assemblies to penetrate bacterial cell membrane as observed in solution. The structure-property-activity relationship developed through this study will provide important guidelines for designing biocompatible peptide hydrogels with built-in antimicrobial activity for various biomedical applications.Hydrogels are an important class of biomaterials that have been widely utilized for a variety of biomedical/medical applications. The biological performance of hydrogels, particularly those used as wound dressing could be greatly advanced if imbued with inherent antimicrobial activity capable of staving off colonization of the wound site by opportunistic bacterial pathogens. Possessing such antimicrobial properties would

  20. HIF-2α dictates the susceptibility of pancreatic cancer cells to TRAIL by regulating survivin expression

    Science.gov (United States)

    Harashima, Nanae; Takenaga, Keizo; Akimoto, Miho; Harada, Mamoru

    2017-01-01

    Cancer cells develop resistance to therapy by adapting to hypoxic microenvironments, and hypoxia-inducible factors (HIFs) play crucial roles in this process. We investigated the roles of HIF-1α and HIF-2α in cancer cell death induced by tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL) using human pancreatic cancer cell lines. siRNA-mediated knockdown of HIF-2α, but not HIF-1α, increased susceptibility of two pancreatic cancer cell lines, Panc-1 and AsPC-1, to TRAIL in vitro under normoxic and hypoxic conditions. The enhanced sensitivity to TRAIL was also observed in vivo. This in vitro increased TRAIL sensitivity was observed in other three pancreatic cancer cell lines. An array assay of apoptosis-related proteins showed that knockdown of HIF-2α decreased survivin expression. Additionally, survivin promoter activity was decreased in HIF-2α knockdown Panc-1 cells and HIF-2α bound to the hypoxia-responsive element in the survivin promoter region. Conversely, forced expression of the survivin gene in HIF-2α shRNA-expressing Panc-1 cells increased resistance to TRAIL. In a xenograft mouse model, the survivin suppressant YM155 sensitized Panc-1 cells to TRAIL. Collectively, our results indicate that HIF-2α dictates the susceptibility of human pancreatic cancer cell lines, Panc-1 and AsPC-1, to TRAIL by regulating survivin expression transcriptionally, and that survivin could be a promising target to augment the therapeutic efficacy of death receptor-targeting anti-cancer therapy. PMID:28476028

  1. Speech Recognition for Medical Dictation: Overview in Quebec and Systematic Review.

    Science.gov (United States)

    Poder, Thomas G; Fisette, Jean-François; Déry, Véronique

    2018-04-03

    Speech recognition is increasingly used in medical reporting. The aim of this article is to identify in the literature the strengths and weaknesses of this technology, as well as barriers to and facilitators of its implementation. A systematic review of systematic reviews was performed using PubMed, Scopus, the Cochrane Library and the Center for Reviews and Dissemination through August 2017. The gray literature has also been consulted. The quality of systematic reviews has been assessed with the AMSTAR checklist. The main inclusion criterion was use of speech recognition for medical reporting (front-end or back-end). A survey has also been conducted in Quebec, Canada, to identify the dissemination of this technology in this province, as well as the factors leading to the success or failure of its implementation. Five systematic reviews were identified. These reviews indicated a high level of heterogeneity across studies. The quality of the studies reported was generally poor. Speech recognition is not as accurate as human transcription, but it can dramatically reduce turnaround times for reporting. In front-end use, medical doctors need to spend more time on dictation and correction than required with human transcription. With speech recognition, major errors occur up to three times more frequently. In back-end use, a potential increase in productivity of transcriptionists was noted. In conclusion, speech recognition offers several advantages for medical reporting. However, these advantages are countered by an increased burden on medical doctors and by risks of additional errors in medical reports. It is also hard to identify for which medical specialties and which clinical activities the use of speech recognition will be the most beneficial.

  2. Transcription factor assisted loading and enhancer dynamics dictate the hepatic fasting response

    Science.gov (United States)

    Goldstein, Ido; Baek, Songjoon; Presman, Diego M.; Paakinaho, Ville; Swinstead, Erin E.; Hager, Gordon L.

    2017-01-01

    Fasting elicits transcriptional programs in hepatocytes leading to glucose and ketone production. This transcriptional program is regulated by many transcription factors (TFs). To understand how this complex network regulates the metabolic response to fasting, we aimed at isolating the enhancers and TFs dictating it. Measuring chromatin accessibility revealed that fasting massively reorganizes liver chromatin, exposing numerous fasting-induced enhancers. By utilizing computational methods in combination with dissecting enhancer features and TF cistromes, we implicated four key TFs regulating the fasting response: glucocorticoid receptor (GR), cAMP responsive element binding protein 1 (CREB1), peroxisome proliferator activated receptor alpha (PPARA), and CCAAT/enhancer binding protein beta (CEBPB). These TFs regulate fuel production by two distinctly operating modules, each controlling a separate metabolic pathway. The gluconeogenic module operates through assisted loading, whereby GR doubles the number of sites occupied by CREB1 as well as enhances CREB1 binding intensity and increases accessibility of CREB1 binding sites. Importantly, this GR-assisted CREB1 binding was enhancer-selective and did not affect all CREB1-bound enhancers. Single-molecule tracking revealed that GR increases the number and DNA residence time of a portion of chromatin-bound CREB1 molecules. These events collectively result in rapid synergistic gene expression and higher hepatic glucose production. Conversely, the ketogenic module operates via a GR-induced TF cascade, whereby PPARA levels are increased following GR activation, facilitating gradual enhancer maturation next to PPARA target genes and delayed ketogenic gene expression. Our findings reveal a complex network of enhancers and TFs that dynamically cooperate to restore homeostasis upon fasting. PMID:28031249

  3. Role of plasma membrane surface charges in dictating the feasibility of membrane-nanoparticle interactions

    Science.gov (United States)

    Sinha, Shayandev; Jing, Haoyuan; Sachar, Harnoor Singh; Das, Siddhartha

    2017-12-01

    Receptor-ligand (R-L) binding mediated interactions between the plasma membrane (PM) and a nanoparticle (NP) require the ligand-functionalized NPs to come to a distance of separation (DOS) of at least dRL (length of the R-L complex) from the receptor-bearing membranes. In this letter, we establish that the membrane surface charges and the surrounding ionic environment dictate whether or not the attainment of such a critical DOS is possible. The negatively charged membrane invariably induces a negative electrostatic potential at the NP surface, repelling the NP from the membrane. This is countered by the attractive influences of the thermal fluctuations and van der Waals (vdw) interactions that drive the NP close to the membrane. For a NP approaching the membrane from a distance, the ratio of the repulsive (electrostatic) and attractive (thermal and vdW) effects balances at a critical NP-membrane DOS of dg,c. For a given set of parameters, there can be two possible values of dg,c, namely, dg,c,1 and dg,c,2 with dg,c,1 ≫ dg,c,2. We establish that any R-L mediated NP-membrane interaction is possible only if dRL > dg,c,1. Therefore, our study proposes a design criterion for engineering ligands for a NP that will ensure the appropriate length of the R-L complex in order to ensure the successful membrane-NP interaction in the presence of a given electrostatic environment. Finally, we discuss the manner in which our theory can help designing ligand-grafted NPs for targeted drug delivery, design biomimetics NPs, and also explain various experimental results.

  4. Cellular Microenvironment Dictates Androgen Production by Murine Fetal Leydig Cells in Primary Culture1

    Science.gov (United States)

    Carney, Colleen M.; Muszynski, Jessica L.; Strotman, Lindsay N.; Lewis, Samantha R.; O'Connell, Rachel L.; Beebe, David J.; Theberge, Ashleigh B.; Jorgensen, Joan S.

    2014-01-01

    ABSTRACT Despite the fact that fetal Leydig cells are recognized as the primary source of androgens in male embryos, the mechanisms by which steroidogenesis occurs within the developing testis remain unclear. A genetic approach was used to visualize and isolate fetal Leydig cells from remaining cells within developing mouse testes. Cyp11a1-Cre mice were bred to mT/mG dual reporter mice to target membrane-tagged enhanced green fluorescent protein (GFP) within steroidogenic cells, whereas other cells expressed membrane-tagged tandem-dimer tomato red. Fetal Leydig cell identity was validated using double-labeled immunohistochemistry against GFP and the steroidogenic enzyme 3beta-HSD, and cells were successfully isolated as indicated by qPCR results from sorted cell populations. Because fetal Leydig cells must collaborate with neighboring cells to synthesize testosterone, we hypothesized that the fetal Leydig cell microenvironment defined their capacity for androgen production. Microfluidic culture devices were used to measure androstenedione and testosterone production of fetal Leydig cells that were cultured in cell-cell contact within a mixed population, were isolated but remained in medium contact via compartmentalized co-culture with other testicular cells, or were isolated and cultured alone. Results showed that fetal Leydig cells maintained their identity and steroidogenic activity for 3–5 days in primary culture. Microenvironment dictated proficiency of testosterone production. As expected, fetal Leydig cells produced androstenedione but not testosterone when cultured in isolation. More testosterone accumulated in medium from mixed cultures than from compartmentalized co-cultures initially; however, co-cultures maintained testosterone synthesis for a longer time. These data suggest that a combination of cell-cell contact and soluble factors constitute the ideal microenvironment for fetal Leydig cell activity in primary culture. PMID:25143354

  5. A Comparison of the Incremental Difference between the Beginning and Ending Heart Rate When Shorthand Writers Are Informed and Not Informed of Speeds of Dictation.

    Science.gov (United States)

    Dickey, Patsy A.

    1980-01-01

    Forty female students were used to compare the incremental difference in heart rate of shorthand writers when they were informed and not informed of shorthand speeds prior to dictation. It was concluded that students' performances were enhanced by receiving instructions as to speed of dictation prior to the take. (Author/CT)

  6. A late requirement for Wnt and FGF signalling during activin-induced formation of foregut endoderm from mouse embryonic stem cells

    DEFF Research Database (Denmark)

    Hansson, Mattias; Petersen, Dorthe Rønn; Peterslund, Janny M.L.

    2009-01-01

    Here we examine how BMP, Wnt, and FGF signaling modulate activin-induced mesendodermal differentiation of mouse ES cells grown under defined conditions in adherent monoculture. We monitor ES cells containing reporter genes for markers of primitive streak (PS) and its progeny and extend previous...... is found at the lowest activin concentration. The expression of Gsc and other anterior markers induced by activin is prevented by treatment with BMP4, which induces T expression and subsequent mesodermal development. We show that canonical Wnt signaling is required only during late stages of activin....... Notably, activin induction of Gsc-GFP(+) cells appears refractory to inhibition of canonical Wnt signaling but shows a dependence on early as well as late FGF signaling. Additionally, we find a late dependence on FGF signaling during induction of Sox17(+) cells by activin while BMP4-induced T expression...

  7. Clinical Simulation and Workflow by use of two Clinical Information Systems, the Electronic Health Record and Digital Dictation

    DEFF Research Database (Denmark)

    Schou Jensen, Iben; Koldby, Sven

    2013-01-01

    digital dictation and the EHR (electronic health record) were simulated in realistic and controlled clinical environments. Useful information dealing with workflow and patient safety were obtained. The clinical simulation demonstrated that the EHR locks during use of the integration of digital dictation......Clinical information systems do not always support clinician workflows. An increasing number of unintended clinical inci-dents might be related to implementation of clinical infor-mation systems and to a new registration praxis of unin-tended clinical incidents. Evidence of performing clinical...... simulations before implementation of new clinical information systems provides the basis for use of this method. The intention has been to evaluate patient safety issues, functionality, workflow, and usefulness of a new solution before implementation in the hospitals. Use of a solution which integrates...

  8. The effect of amount and tangibility of endowment and certainty of recipients on selfishness in a modified dictator game.

    Science.gov (United States)

    Chang, Shao-Chuan; Lin, Li-Yun; Horng, Ruey-Yun; Wang, Yau-De

    2014-06-01

    Taiwanese college students (N = 101) participated in the study to examine the effects of the amount of an endowment, the tangibility of an endowment, and the certainty of the recipient on selfishness in a modified dictator game. Results showed that dictators were more selfish when allocating tangible (money) than less tangible (honor credits) endowments. Selfishness was higher when large amounts of money were involved. The certainty of the recipient was manipulated by whether the recipient was chosen and announced before or after the decision. Unexpectedly, participants were more self-interested in the certain-recipient condition than in the uncertain-recipient condition. In the honor condition, the amount of an endowment and the certainty of the recipient did not affect participants' allocations.

  9. Regulatory T cell suppressive potency dictates the balance between bacterial proliferation and clearance during persistent Salmonella infection.

    Directory of Open Access Journals (Sweden)

    Tanner M Johanns

    2010-08-01

    Full Text Available The pathogenesis of persistent infection is dictated by the balance between opposing immune activation and suppression signals. Herein, virulent Salmonella was used to explore the role and potential importance of Foxp3-expressing regulatory T cells in dictating the natural progression of persistent bacterial infection. Two distinct phases of persistent Salmonella infection are identified. In the first 3-4 weeks after infection, progressively increasing bacterial burden was associated with delayed effector T cell activation. Reciprocally, at later time points after infection, reductions in bacterial burden were associated with robust effector T cell activation. Using Foxp3(GFP reporter mice for ex vivo isolation of regulatory T cells, we demonstrate that the dichotomy in infection tempo between early and late time points is directly paralleled by drastic changes in Foxp3(+ Treg suppressive potency. In complementary experiments using Foxp3(DTR mice, the significance of these shifts in Treg suppressive potency on infection outcome was verified by enumerating the relative impacts of regulatory T cell ablation on bacterial burden and effector T cell activation at early and late time points during persistent Salmonella infection. Moreover, Treg expression of CTLA-4 directly paralleled changes in suppressive potency, and the relative effects of Treg ablation could be largely recapitulated by CTLA-4 in vivo blockade. Together, these results demonstrate that dynamic regulation of Treg suppressive potency dictates the course of persistent bacterial infection.

  10. [The cultural history of palliative care in primitive societies: an integrative review].

    Science.gov (United States)

    Siles González, José; Solano Ruiz, Maria Del Carmen

    2012-08-01

    The objective of this study is to describe the evolution of palliative care in order to reflect on the possibility of its origin in primitive cultures and their relationship with the beginnings of the cult of the dead. It describes the change in the symbolic structures and social interactions involved in palliative care during prehistory: functional unit, functional framework and functional element. The theoretical framework is based on cultural history, the dialectical structural model and symbolic interactionism. Categorization techniques, cultural history and dialectic structuralism analyses were performed. Palliative care existed in primitive societies, mostly associated with the rites of passage with a high symbolic content. The social structures - functional unit, functional framework and functional element - are the pillars that supported palliative care in prehistory societies.

  11. New software library of geometrical primitives for modelling of solids used in Monte Carlo detector simulations

    CERN Multimedia

    CERN. Geneva

    2012-01-01

    We present our effort for the creation of a new software library of geometrical primitives, which are used for solid modelling in Monte Carlo detector simulations. We plan to replace and unify current geometrical primitive classes in the CERN software projects Geant4 and ROOT with this library. Each solid is represented by a C++ class with methods suited for measuring distances of particles from the surface of a solid and for determination as to whether the particles are located inside, outside or on the surface of the solid. We use numerical tolerance for determining whether the particles are located on the surface. The class methods also contain basic support for visualization. We use dedicated test suites for validation of the shape codes. These include also special performance and numerical value comparison tests for help with analysis of possible candidates of class methods as well as to verify that our new implementation proposals were designed and implemented properly. Currently, bridge classes are u...

  12. Listening to Quackery: Reading John Wesley's Primitive Physic in an Age of Health Care Reform.

    Science.gov (United States)

    Skinner, Daniel; Schneider, Adam

    2016-11-25

    This article uses a reading of John Wesley's Primitive Physic, or An Easy and Natural Method of Curing Most Diseases (1747) to resist the common rejection-often as "quackery"-of Wesley's treatments for common maladies. We engage Wesley not because he was right but because his approach offers useful moments of pause in light of contemporary medical epistemology. Wesley's recommendations were primarily oriented towards the categories of personal responsibility and capability, but he also sought to empower individuals-especially the poor-with the knowledge to safely and affordably treat maladies of their own. We leverage Primitive Physic to rethink contemporary medical knowledge production, especially as sanctioned by randomized clinical trials and legitimate views of experience and contemporary institutions such as the AMA. Ultimately, we suggest that the medical humanities has a key role to play in mining the discarded and dismissed for what they can tell scholars about medical knowledge.

  13. Western Imperialism Against Primitive Communism. A New Reading of Rosa Luxemburg’s Economic Writings

    Directory of Open Access Journals (Sweden)

    Michael Löwy

    2012-01-01

    Full Text Available The discussion on Rosa Luxemburg’s theories of imperialism hasmainly focused on the economic argument - the schemes of reproduction, theprocess of circulation, the need for “external” markets, etc. There is howeveranother dimension, at least as important : the struggle of imperialism againstpre-capitalist economies, the ruthless destruction of “natural” and peasant economies,many of them being forms of primitive communism. Luxemburg’sinterest for primitive communist societies is documented by her Introductionto Political Economy and the imperialist war against them is discussed both inthis work and in the last chapters of The Accumulation of Capital. A whollyoriginal approach to the evolution of social formations, running counter tolinear “progressive” views of bourgeois ideology, is outlined in these reflections. Present indigenous struggles e.g. in Latin America, against multinational oil or mining companies, illustrate the topicality of Rosa Luxemburg’s argument in the 21th century.

  14. Clinical and pathological characteristics of primitive neuroectodermal tumor of the cerebral

    International Nuclear Information System (INIS)

    Fu Jun; Zhou Youxin; Xu Feng; Ye Ming; Zhou Dai; Bao Yaodong; Kang Suya

    2004-01-01

    Objective: To study the features of the cerebral primitive neuroectodermal tumor (PNET) in the clinical manifestation and in the histogenesis, morphology. Methods: Seven cases of cerebral PNET was analyzed with their clinical manifestations, histologic and immunohistochemical results. Results: Five patients of this group were children or young adults. Seven tumors were composed of primitive cells with focal evidence of glial or neuronal differentiation. Five out seven expressed NSE, one out seven expressed Syn, two out seven expressed CD99 and only one case expressed Vimentin, None expressed GFAP and S-100. CT findings were a homogeneous high density or heterogeneous mass. MR findings were high signal intensity both on T1 and T2 images. Conclusion: To diagnose the cerebral PNET depends on pathology and cerebral PNET have poor prognosis

  15. Organic cofactors participated more frequently than transition metals in redox reactions of primitive proteins.

    Science.gov (United States)

    Ji, Hong-Fang; Chen, Lei; Zhang, Hong-Yu

    2008-08-01

    Protein redox reactions are one of the most basic and important biochemical actions. As amino acids are weak redox mediators, most protein redox functions are undertaken by protein cofactors, which include organic ligands and transition metal ions. Since both kinds of redox cofactors were available in the pre-protein RNA world, it is challenging to explore which one was more involved in redox processes of primitive proteins? In this paper, using an examination of the redox cofactor usage of putative ancient proteins, we infer that organic ligands participated more frequently than transition metals in redox reactions of primitive proteins, at least as protein cofactors. This is further supported by the relative abundance of amino acids in the primordial world. Supplementary material for this article can be found on the BioEssays website. (c) 2008 Wiley Periodicals, Inc.

  16. John Wesley’s medical guide Primitive Physick from 1747: science, charlatanism or social medicine?

    Directory of Open Access Journals (Sweden)

    Helmut Renders

    2011-05-01

    Full Text Available In 1747, John Wesley, spiritus rector of the Methodist movement, published the first edition of his medical guide Primitive Physic[k]. What was its purpose in a world where the Royal Academy, herbalists, healers / as, exorcists and quacks competed for the attention of the population? What is its legacy and limitation, considering the different interests of contemporary religious movements in Brazil? The article introduces the different groups who promoted or pretended to promote health in 18th century England and compares the contents of the guide Primitive Physic [k] with their proposals and therapeutic strategies. The conclusion is that a significant portion of the guide consists of guidelines of the Royal Academy of Medicine, but that it always favors homemade remedies with ingredients available to humbler classes. In relation to the socalled Spiritual Physick, prayer is mentioned as a complementary measure, but the practice of exorcism is totally ignored.

  17. Dispossessing Urbanization: Urban Marxism in the Face of the Problem of Primitive Accumulation

    OpenAIRE

    Piotr Juskowiak

    2015-01-01

    The article is a complex attempt to present the achievements of the broadly understood urban Marxism in the field of reinterpretation of the classic concept from the cards of Capital – “primitive accumulation”. Drawing on theories of such scholars as David Harvey (“accumulation by dispossession”) or Saskia Sassen (“expulsions”), the author points to the possible ways to operationalize the concept of “dispossessing urbanization”. Inspired by the theorizations of autonomist Marxists (Antonio Ne...

  18. Abundances of presolar silicon carbide grains in primitive meteorites determined by NanoSIMS

    Science.gov (United States)

    Davidson, Jemma; Busemann, Henner; Nittler, Larry R.; Alexander, Conel M. O.'D.; Orthous-Daunay, François-Régis; Franchi, Ian A.; Hoppe, Peter

    2014-08-01

    It has been suggested that the matrices of all chondrites are dominated by a common material with Ivuna-like (CI) abundances of volatiles, presolar grains and insoluble organic matter (IOM) (e.g., Alexander, 2005). However, matrix-normalized abundances of presolar silicon carbide (SiC) grains estimated from their noble gas components show significant variations in even the most primitive chondrites (Huss and Lewis, 1995; Huss et al., 2003), in contradiction to there being a common chondrite matrix material. Here we report presolar SiC abundances determined by NanoSIMS raster ion imaging of IOM extracted from primitive members of different meteorite groups. We show that presolar SiC abundance determinations are comparable between NanoSIMS instruments located at three different institutes, between residues prepared by different demineralization techniques, and between microtomed and non-microtomed samples. Our derived SiC abundances in CR chondrites are comparable to those found in the CI chondrites (∼30 ppm) and are much higher than previously determined by noble gas analyses. The revised higher CR SiC abundances are consistent with the CRs being amongst the most primitive chondrites in terms of the isotopic compositions and disordered nature of their organic matter. Similar abundances between CR1, CR2, and CR3 chondrites indicate aqueous alteration on the CR chondrite parent body has not progressively destroyed SiC grains in them. A low SiC abundance for the reduced CV3 RBT 04133 can be explained by parent body thermal metamorphism at an estimated temperature of ∼440 °C. Minor differences between primitive members of other meteorite classes, which did not experience such high temperatures, may be explained by prolonged oxidation at lower temperatures under which SiC grains formed outer layers of SiO2 that were not thermodynamically stable, leading to progressive degassing/destruction of SiC.

  19. Lower Virial Coefficients of Primitive Models of Polar and Associating Fluids.

    Czech Academy of Sciences Publication Activity Database

    Rouha, M.; Nezbeda, Ivo

    2007-01-01

    Roč. 134, 1-3 (2007) , s. 107-110 Sp. Iss. SI ISSN 0167-7322 R&D Projects: GA AV ČR(CZ) IAA4072303; GA AV ČR(CZ) 1ET400720409 Institutional research plan: CEZ:AV0Z40720504 Keywords : primitive models * virial coefficients * metropolis like monte-carlo integration Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 0.982, year: 2007

  20. Enslaved African Labour in the Americas: from primitive accumulation to manufacture with racial violence

    OpenAIRE

    Higginbottom, Andy

    2018-01-01

    This paper reconceptualises Marx’s value theory in an analysis of the enslavement of African Americans as a part of the capitalist mode of production with its own special characteristics. Synthesising from the literature, I argue that sugar plantation slavery from the sixteenth into the nineteenth century had a duel relation concerning the debate over primitive accumulation vs. capitalism from the start. The plantation did represent an early form of specifically capitalist production, in that...

  1. Primitive myxoid mesenchymal tumor of infancy: a report of a further case with locally aggressive behavior.

    LENUS (Irish Health Repository)

    Mulligan, Linda

    2011-01-01

    We report a case of an 8-month-old child with a primitive myxoid mesenchymal tumor of infancy arising in the thenar eminence. The lesion recurred after conservative excision and was ultimately nonresponsive to chemotherapy, necessitating partial amputation. The patient remains free of disease 5 years after this radical surgery. This is the 1st report of such a tumor since it was initially described by Alaggio and colleagues in 2006. The pathologic differential diagnosis is discussed.

  2. Node Primitives: an open end-user programming platform for social robots

    OpenAIRE

    Coronado, Enrique; Mastrogiovanni, Fulvio; Venture, Gentiane

    2017-01-01

    With the expected adoption of robots able to seamlessly and intuitively interact with people in real-world scenarios, the need arises to provide non-technically-skilled users with easy-to-understand paradigms for customising robot behaviors. In this paper, we present an interaction design robot programming platform for enabling multidisciplinary social robot research and applications. This platform is referred to Node Primitives (NEP) and consists of two main parts. On the one hand, a ZeroMQ ...

  3. Primitive myxoid mesenchymal tumor of infancy: a report of a further case with locally aggressive behavior.

    LENUS (Irish Health Repository)

    Mulligan, Linda

    2012-02-01

    We report a case of an 8-month-old child with a primitive myxoid mesenchymal tumor of infancy arising in the thenar eminence. The lesion recurred after conservative excision and was ultimately nonresponsive to chemotherapy, necessitating partial amputation. The patient remains free of disease 5 years after this radical surgery. This is the 1st report of such a tumor since it was initially described by Alaggio and colleagues in 2006. The pathologic differential diagnosis is discussed.

  4. Rho kinase activity controls directional cell movements during primitive streak formation in the rabbit embryo.

    Science.gov (United States)

    Stankova, Viktoria; Tsikolia, Nikoloz; Viebahn, Christoph

    2015-01-01

    During animal gastrulation, the specification of the embryonic axes is accompanied by epithelio-mesenchymal transition (EMT), the first major change in cell shape after fertilization. EMT takes place in disparate topographical arrangements, such as the circular blastopore of amphibians, the straight primitive streak of birds and mammals or in intermediate gastrulation forms of other amniotes such as reptiles. Planar cell movements are prime candidates to arrange specific modes of gastrulation but there is no consensus view on their role in different vertebrate classes. Here, we test the impact of interfering with Rho kinase-mediated cell movements on gastrulation topography in blastocysts of the rabbit, which has a flat embryonic disc typical for most mammals. Time-lapse video microscopy, electron microscopy, gene expression and morphometric analyses of the effect of inhibiting ROCK activity showed - besides normal specification of the organizer region - a dose-dependent disruption of primitive streak formation; this disruption resulted in circular, arc-shaped or intermediate forms, reminiscent of those found in amphibians, fishes and reptiles. Our results reveal a crucial role of ROCK-controlled directional cell movements during rabbit primitive streak formation and highlight the possibility that temporal and spatial modulation of cell movements were instrumental for the evolution of gastrulation forms. © 2015. Published by The Company of Biologists Ltd.

  5. Wnt signaling controls the specification of definitive and primitive hematopoiesis from human pluripotent stem cells.

    Science.gov (United States)

    Sturgeon, Christopher M; Ditadi, Andrea; Awong, Geneve; Kennedy, Marion; Keller, Gordon

    2014-06-01

    Efforts to derive hematopoietic stem cells (HSCs) from human pluripotent stem cells (hPSCs) are complicated by the fact that embryonic hematopoiesis consists of two programs, primitive and definitive, that differ in developmental potential. As only definitive hematopoiesis generates HSCs, understanding how this program develops is essential for being able to produce this cell population in vitro. Here we show that both hematopoietic programs transition through hemogenic endothelial intermediates and develop from KDR(+)CD34(-)CD144(-) progenitors that are distinguished by CD235a expression. Generation of primitive progenitors (KDR(+)CD235a(+)) depends on stage-specific activin-nodal signaling and inhibition of the Wnt-β-catenin pathway, whereas specification of definitive progenitors (KDR(+)CD235a(-)) requires Wnt-β-catenin signaling during this same time frame. Together, these findings establish simple selective differentiation strategies for the generation of primitive or definitive hematopoietic progenitors by Wnt-β-catenin manipulation, and in doing so provide access to enriched populations for future studies on hPSC-derived hematopoietic development.

  6. Development of membrane mechanical function during terminal stages of primitive erythropoiesis in mice.

    Science.gov (United States)

    Waugh, Richard E; Huang, Yu-Shan; Arif, Binish J; Bauserman, Richard; Palis, James

    2013-04-01

    During murine embryogenesis, primitive erythroblasts enter the circulation as immature nucleated cells and progressively mature as a semisynchronous cohort, enucleating between E12.5 and E16.5. In this report, we examine the mechanical properties of these cells to determine how their mechanical development differs from that of definitive erythroid cells, which mature extravascularly in protected marrow microenvironments. Primitive erythroid cells acquire normal membrane deformability by E12.5 (i.e., as late stage erythroblasts) and maintain the same level of surface stiffness through E17.5. During this same period, the strength of association between the membrane bilayer and the underlying skeleton increases, as indicated by an approximate doubling of the energy required to separate bilayer from skeleton. At the same time, these cells undergo dramatic changes in surface area and volume, losing 35% of their surface area and 50% of their volume from E14.5 to E17.5. Interestingly, membrane remodeling proceeded regardless of whether the cells completed enucleation. These data suggest that in primitive erythroid cells, unlike their definitive counterparts, the critical maturational processes of membrane remodeling and enucleation are uncoupled. Copyright © 2013 ISEH - Society for Hematology and Stem Cells. Published by Elsevier Inc. All rights reserved.

  7. The logical primitives of thought: Empirical foundations for compositional cognitive models.

    Science.gov (United States)

    Piantadosi, Steven T; Tenenbaum, Joshua B; Goodman, Noah D

    2016-07-01

    The notion of a compositional language of thought (LOT) has been central in computational accounts of cognition from earliest attempts (Boole, 1854; Fodor, 1975) to the present day (Feldman, 2000; Penn, Holyoak, & Povinelli, 2008; Fodor, 2008; Kemp, 2012; Goodman, Tenenbaum, & Gerstenberg, 2015). Recent modeling work shows how statistical inferences over compositionally structured hypothesis spaces might explain learning and development across a variety of domains. However, the primitive components of such representations are typically assumed a priori by modelers and theoreticians rather than determined empirically. We show how different sets of LOT primitives, embedded in a psychologically realistic approximate Bayesian inference framework, systematically predict distinct learning curves in rule-based concept learning experiments. We use this feature of LOT models to design a set of large-scale concept learning experiments that can determine the most likely primitives for psychological concepts involving Boolean connectives and quantification. Subjects' inferences are most consistent with a rich (nonminimal) set of Boolean operations, including first-order, but not second-order, quantification. Our results more generally show how specific LOT theories can be distinguished empirically. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

  8. Application of a primitive variable Newton's method for the calculation of an axisymmetric laminar diffusion flame

    International Nuclear Information System (INIS)

    Xu, Yuenong; Smooke, M.D.

    1993-01-01

    In this paper we present a primitive variable Newton-based solution method with a block-line linear equation solver for the calculation of reacting flows. The present approach is compared with the stream function-vorticity Newton's method and the SIMPLER algorithm on the calculation of a system of fully elliptic equations governing an axisymmetric methane-air laminar diffusion flame. The chemical reaction is modeled by the flame sheet approximation. The numerical solution agrees well with experimental data in the major chemical species. The comparison of three sets of numerical results indicates that the stream function-vorticity solution using the approximate boundary conditions reported in the previous calculations predicts a longer flame length and a broader flame shape. With a new set of modified vorticity boundary conditions, we obtain agreement between the primitive variable and stream function-vorticity solutions. The primitive variable Newton's method converges much faster than the other two methods. Because of much less computer memory required for the block-line tridiagonal solver compared to a direct solver, the present approach makes it possible to calculate multidimensional flames with detailed reaction mechanisms. The SIMPLER algorithm shows a slow convergence rate compared to the other two methods in the present calculation

  9. A primitive Late Pliocene cheetah, and evolution of the cheetah lineage

    Science.gov (United States)

    Christiansen, Per; Mazák, Ji H.

    2009-01-01

    The cheetah lineage is a group of large, slender, and long-limbed cats with a distinctive skull and dental morphology, of which only the extant cheetah (Acinonyx jubatus) is present today. The lineage is characterized by having abbreviated, tall, and domed crania, and a trenchant dentition with a much reduced, posteriorly placed protocone on the upper carnassial. In this article, we report on a new discovery of a Late Pliocene specimen from China with an estimated age of ≈2.2–2.5 million years, making it one of the oldest specimens known to date. A cladistic analysis confirmed that it is the most primitive cheetah known, and it shares a number of unambiguous derived cranial traits with the Acinonyx lineage, but has more primitive dentition than previously known cheetahs, demonstrating that the many unusual skull and dental characters hitherto considered characteristic of cheetahs evolved in a gradual fashion. Isolated teeth of primitive cheetahs may not be recognizable as such, but can be confused with, for instance, those of leopards or other similar-sized pantherine cats or pumas. The age and morphology of the new specimen supports an Old World origin of the cheetah lineage, not a New World one, as has been suggested. We name the new species Acinonyx kurteni in honor of the late Björn Kurtén. PMID:19114651

  10. Looking for the most ``primitive'' organism(s) on Earth today: the state of the art

    Science.gov (United States)

    Forterre, Patrick

    1995-02-01

    Molecular phylogenetic studies have revealed a tripartite division of the living world into two procaryotic groups, Bacteria and Archaea, and one eucaryotic group, Eucarya. Which group is the most "primitive"? Which groups are sister? The answer to these questions would help to delineate the characters of the last common ancestor to all living beings, as a first step to reconstruct the earliest periods of biological evolution on Earth. The current "Procaryotic dogma" claims that procaryotes are primitive. Since the ancestor of Archaea was most probably a hyperthermophile, and since bacteria too might have originated from hyperthermophiles, the procaryotic dogma has been recently connected to the hot origin of life hypothesis. However, the notion that present-day hyperthermophiles are primitive has been challenged by recent findings, in these unique microorganisms, of very elaborate adaptative devices for life at high temperature. Accordingly, I discuss here alternative hypotheses that challenge the procaryotic dogma, such as the idea of a universal ancestor with molecular features in between those of eucaryotes and procaryotes, or the origin of procaryotes via thermophilic adaptation. Clearly, major evolutionary questions about early cellular evolution on Earth remain to be settled before we can speculate with confidence about which kinds of life might have appeared on other planets.

  11. Primitive neuroectodermal tumour of the kidney with vena caval and atrial tumour thrombus: a case report

    Directory of Open Access Journals (Sweden)

    Ong Poh

    2008-08-01

    Full Text Available Abstract Introduction Renal primitive neuroectodermal tumour is an extremely rare malignancy. Case presentation A 21-year-old woman presented with microscopic haematuria, a palpable right loin mass, dyspnoea, dizziness and fatigue. Initial ultrasound scan of the kidneys revealed an 11 cm right renal mass with venous extension into the inferior vena cava. Computed tomography of the thorax and abdomen revealed an extension of the large renal mass into the right renal vein, inferior vena cava and up to the right atrium. A small paracaval lymph node was noted and three small metastatic nodules were identified within the lung parenchyma. The patient underwent a radical nephrectomy and inferior vena caval tumour (level IV thrombectomy with cardiopulmonary bypass and deep hypothermic circulatory arrest. Immunohistochemical staining of the specimen showed a highly specific cluster of differentiation (CD 99, thus confirming the diagnosis of a primitive neuroectodermal tumour. Conclusion It is important that a renal primitive neuroectodermal tumour be considered, particularly in young patients with a renal mass and extensive thrombus.

  12. A primitive Late Pliocene cheetah, and evolution of the cheetah lineage.

    Science.gov (United States)

    Christiansen, Per; Mazák, Ji H

    2009-01-13

    The cheetah lineage is a group of large, slender, and long-limbed cats with a distinctive skull and dental morphology, of which only the extant cheetah (Acinonyx jubatus) is present today. The lineage is characterized by having abbreviated, tall, and domed crania, and a trenchant dentition with a much reduced, posteriorly placed protocone on the upper carnassial. In this article, we report on a new discovery of a Late Pliocene specimen from China with an estimated age of approximately 2.2-2.5 million years, making it one of the oldest specimens known to date. A cladistic analysis confirmed that it is the most primitive cheetah known, and it shares a number of unambiguous derived cranial traits with the Acinonyx lineage, but has more primitive dentition than previously known cheetahs, demonstrating that the many unusual skull and dental characters hitherto considered characteristic of cheetahs evolved in a gradual fashion. Isolated teeth of primitive cheetahs may not be recognizable as such, but can be confused with, for instance, those of leopards or other similar-sized pantherine cats or pumas. The age and morphology of the new specimen supports an Old World origin of the cheetah lineage, not a New World one, as has been suggested. We name the new species Acinonyx kurteni in honor of the late Björn Kurtén.

  13. Lipofectamine and related cationic lipids strongly improve adenoviral infection efficiency of primitive human hematopoietic cells.

    Science.gov (United States)

    Byk, T; Haddada, H; Vainchenker, W; Louache, F

    1998-11-20

    Adenoviral vectors have the potential to infect a large number of cell types including quiescent cells. Their use in hematopoietic cells is limited by the episomal form of their DNA, leading to transgene loss in the progeny cells. However, the use of this vector may be interesting for short-term in vitro modifications of primitive human hematopoietic cells. Therefore, we have investigated the ability of adenovirus to transduce cord blood CD34+ cells. Several promoters were tested using the lacZ reporter gene. The PGK and CMV promoters induced transgene expression in 18-25% of the cells, whereas the HTLV-I and especially the RSV promoter were almost inactive. To improve infection efficiency, adenovirus was complexed with cationic lipids. Lipofectamine, Cellfectin, and RPR120535b, but not Lipofectin, Lipofectace, or DOTAP, markedly improved transgene expression in CD34+ cells (from 19 to 35%). Lipofectamine strongly enhanced infection efficiency of the poorly infectable primitive CD34+CD38low cells (from 11 to 28%) whereas the more mature CD34+CD38+ cells were only slightly affected (from 24 to 31%). Lipofectamine tripled the infection of CFU-GMs and LTC-ICs derived from the CD34+CD38low cell fraction (from 4 to 12% and from 5 to 16%, respectively) and doubled that of BFU-Es (from 13 to 26%). We conclude that cationic lipids can markedly increase the efficiency of adenovirus-mediated gene transfer into primitive hematopoietic cells.

  14. The language of geometry: Fast comprehension of geometrical primitives and rules in human adults and preschoolers

    Science.gov (United States)

    Amalric, Marie; Wang, Liping; Figueira, Santiago; Sigman, Mariano; Dehaene, Stanislas

    2017-01-01

    During language processing, humans form complex embedded representations from sequential inputs. Here, we ask whether a “geometrical language” with recursive embedding also underlies the human ability to encode sequences of spatial locations. We introduce a novel paradigm in which subjects are exposed to a sequence of spatial locations on an octagon, and are asked to predict future locations. The sequences vary in complexity according to a well-defined language comprising elementary primitives and recursive rules. A detailed analysis of error patterns indicates that primitives of symmetry and rotation are spontaneously detected and used by adults, preschoolers, and adult members of an indigene group in the Amazon, the Munduruku, who have a restricted numerical and geometrical lexicon and limited access to schooling. Furthermore, subjects readily combine these geometrical primitives into hierarchically organized expressions. By evaluating a large set of such combinations, we obtained a first view of the language needed to account for the representation of visuospatial sequences in humans, and conclude that they encode visuospatial sequences by minimizing the complexity of the structured expressions that capture them. PMID:28125595

  15. Influence of sediment recycling on the trace element composition of primitive arc lavas

    Science.gov (United States)

    Collinet, M.; Jagoutz, O. E.

    2017-12-01

    Primitive calc-alkaline lavas from continental arcs are, on average, enriched in incompatible elements compared to those from intra-oceanic arcs. This relative enrichment is observed in different groups of trace elements: LILE (e.g. K, Rb), LREE to MREE (La-Dy) and HFSE (e.g.Zr, Nb) and is thought to result from (1) a transfer of material from the subducting slab to the mantle wedge at higher temperature than in intra-oceanic margins and/or (2) lower average degrees of melting in the mantle wedge, as a consequence of thicker overlying crusts and higher average pressures of melting. In addition to thicker overlying crusts and generally higher slab temperatures, continental margins are characterized by larger volumes of rock exposed above sea level and enhanced erosion rates compared to intra-oceanic arcs. As several geochemical signatures of arc lavas attest to the importance of sediment recycling in subduction zones, we explore the possibility that the high concentrations of incompatible elements in primitive lavas from continental arcs directly reflect a larger input of sediment to the subduction system. Previous efforts to quantify the sediment flux to oceanic trenches focused on the thickness of pelagic and hemipelagic sediments on top of the plate entering the subduction zone (Plank and Langmuir, 1993, Nature). These estimates primarily relied on the sediment layer drilled outboard from the subduction system and likely underestimate the volume of sediment derived from the arc itself. Accordingly, we find that such estimates of sediment flux do not correlate with the concentration of incompatible elements in primitive arc lavas. To account for regional contributions of coarser detrital sediments, usually delivered to oceanic trenches by turbidity currents, we apply to arc segments a model that quantifies the sediment load of rivers based on the average relief, area, temperature and runoff of their respective drainage areas (Syvitski et al., 2003, Sediment. Geol

  16. Noble Gases in Insoluble Organic Matter in the Very Primitive Meteorites Bells, EET 92042 and GRO 95577

    Science.gov (United States)

    Busemann, H.; Alexander, C. M. O'd.; Nittler, L. R.; Wieler, R.

    2008-03-01

    Noble gas carrier phase Q in several primitive meteorites is not attacked by Pyridine, in contrast to Orgueil, as reported previously. IOM in CR chondrites does not indicate high-temperature alteration in the nebula.

  17. De novo appearance of primitive neuroectodermal tumor in a patient with systemic lupus erythematosus and moyamoya disease.

    Science.gov (United States)

    Park, D J; Kim, T J; Lee, H J; Lee, K E; Lee, S J; Seo, S R; Yoon, W; Moon, K S; Lee, K W; Lee, S S; Park, Y W

    2010-07-01

    Primitive neuroectodermal tumor is a rare brain tumor composed of undifferentiated or poorly differentiated neuroepithelial cells with a high malignant potential that usually occurs in children, and which is only occasionally encountered in adults. A 19-year-old female with systemic lupus erythematosus presented with right hemiparesis and a headache of 10 days duration. Brain magnetic resonance imaging showed a large solid mass with necrotic portions in the left frontoparietal lobe. Primitive neuroectodermal tumor was confirmed by a neuronavigator-guided brain biopsy. This is the first case report of primitive neuroectodermal tumor associated with systemic lupus erythematosus and moyamoya disease. This case demonstrates that brain tumors, such as primitive neuroectodermal tumor, should be included in the differential diagnosis of neurological manifestations in children and adolescent patients with systemic lupus erythematosus.

  18. Efficient and Rapid Derivation of Primitive Neural Stem Cells and Generation of Brain Subtype Neurons From Human Pluripotent Stem Cells

    OpenAIRE

    Yan, Yiping; Shin, Soojung; Jha, Balendu Shekhar; Liu, Qiuyue; Sheng, Jianting; Li, Fuhai; Zhan, Ming; Davis, Janine; Bharti, Kapil; Zeng, Xianmin; Rao, Mahendra; Malik, Nasir; Vemuri, Mohan C.

    2013-01-01

    This study developed a highly efficient serum-free pluripotent stem cell (PSC) neural induction medium that can induce human PSCs into primitive neural stem cells (NSCs) in 7 days, obviating the need for time-consuming, laborious embryoid body generation or rosette picking. This method of primitive NSC derivation sets the stage for the scalable production of clinically relevant neural cells for cell therapy applications in good manufacturing practice conditions.

  19. Primitive magmas at five Cascade volcanic fields: Melts from hot, heterogeneous sub-arc mantle

    Science.gov (United States)

    Bacon, C.R.; Bruggman, P.E.; Christiansen, R.L.; Clynne, M.A.; Donnelly-Nolan, J. M.; Hildreth, W.

    1997-01-01

    Major and trace element concentrations, including REE by isotope dilution, and Sr, Nd, Pb, and O isotope ratios have been determined for 38 mafic lavas from the Mount Adams, Crater Lake, Mount Shasta, Medicine Lake, and Lassen volcanic fields, in the Cascade arc, northwestern part of the United States. Many of the samples have a high Mg# [100Mg/(Mg + FeT) > 60] and Ni content (>140 ppm) such that we consider them to be primitive. We recognize three end-member primitive magma groups in the Cascades, characterized mainly by their trace-element and alkali-metal abundances: (1) High-alumina olivine tholeiite (HAOT) has trace element abundances similar to N-MORB, except for slightly elevated LILE, and has Eu/Eu* > 1. (2) Arc basalt and basaltic andesite have notably higher LILE contents, generally have higher SiO2 contents, are more oxidized, and have higher Cr for a given Ni abundance than HAOT. These lavas show relative depletion in HFSE, have lower HREE and higher LREE than HAOT, and have smaller Eu/Eu* (0.94-1.06). (3) Alkali basalt from the Simcoe volcanic field east of Mount Adams represents the third end-member, which contributes an intraplate geochemical signature to magma compositions. Notable geochemical features among the volcanic fields are: (1) Mount Adams rocks are richest in Fe and most incompatible elements including HFSE; (2) the most incompatible-element depleted lavas occur at Medicine Lake; (3) all centers have relatively primitive lavas with high LILE/HFSE ratios but only the Mount Adams, Lassen, and Medicine Lake volcanic fields also have relatively primitive rocks with an intraplate geochemical signature; (4) there is a tendency for increasing 87Sr/86Sr, 207Pb/204Pb, and ??18O and decreasing 206Pb/204Pb and 143Nd/144Nd from north to south. The three end-member Cascade magma types reflect contributions from three mantle components: depleted sub-arc mantle modestly enriched in LILE during ancient subduction; a modern, hydrous subduction component

  20. A compact representation of drawing movements with sequences of parabolic primitives.

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    Felix Polyakov

    2009-07-01

    Full Text Available Some studies suggest that complex arm movements in humans and monkeys may optimize several objective functions, while others claim that arm movements satisfy geometric constraints and are composed of elementary components. However, the ability to unify different constraints has remained an open question. The criterion for a maximally smooth (minimizing jerk motion is satisfied for parabolic trajectories having constant equi-affine speed, which thus comply with the geometric constraint known as the two-thirds power law. Here we empirically test the hypothesis that parabolic segments provide a compact representation of spontaneous drawing movements. Monkey scribblings performed during a period of practice were recorded. Practiced hand paths could be approximated well by relatively long parabolic segments. Following practice, the orientations and spatial locations of the fitted parabolic segments could be drawn from only 2-4 clusters, and there was less discrepancy between the fitted parabolic segments and the executed paths. This enabled us to show that well-practiced spontaneous scribbling movements can be represented as sequences ("words" of a small number of elementary parabolic primitives ("letters". A movement primitive can be defined as a movement entity that cannot be intentionally stopped before its completion. We found that in a well-trained monkey a movement was usually decelerated after receiving a reward, but it stopped only after the completion of a sequence composed of several parabolic segments. Piece-wise parabolic segments can be generated by applying affine geometric transformations to a single parabolic template. Thus, complex movements might be constructed by applying sequences of suitable geometric transformations to a few templates. Our findings therefore suggest that the motor system aims at achieving more parsimonious internal representations through practice, that parabolas serve as geometric primitives and that non

  1. Versatility of `hemorheologic fitness' according to exercise intensity: emphasis on the "healthy primitive lifestyle"

    Science.gov (United States)

    Brun, Jean-Frédéric; Varlet-Marie, Emmanuelle; Chevance, Guillaume; Pollatz, Marion; Fedou, Christine; de Mauverger, Eric Raynaud

    2014-05-01

    We recently proposed a unifying hypothesis to reconcile unexpected findings in exercise hemorheology and the classical concepts of "hemorheologic fitness" and the "triphasic effects of exercise", based on the "healthy primitive lifestyle" paradigm. This paradigm assumes that evolution has selected genetic polymorphisms leading to insulin resistance as an adaptative strategy to cope with continuous low intensity physical activity and a special alimentation moderately high in protein, rich in low glycemic index carbohydrates, and poor in saturated fat. According to this protocol the true physiological picture would be that of an individual whose exercise and nutritional habits are close from this lifestyle, both sedentary subjects and trained athletes representing situations on the edge of this model. Unfortunately samples of people truly adhering to this ancestral lifestyle are hard to obtain. In order to address this picture we tried to compare databases obtained with our preceding published studies. As a model of the "healthy primitive lifestyle" we selected patients trained at low intensity (LI) and given an advice of protein intake around 1.2 g/kg/day. Results show a continuum for plasma viscosity which seems to be lower in athletes than LI-trained and even more sedentaries. When sedentary subjects become obese the most obvious characteristic is an increase in red blood cell (RBC) aggregation correlated to the size of fat stores. It is clear that 3 months of LI are not a perfect model of "healthy primitive lifestyle", but these data suggest that the most important effect of LI regular exercise is to decrease plasma viscosity and that sedentarity increases RBC aggregation mostly when it results in increased fat storage.

  2. A musculoskeletal model of human locomotion driven by a low dimensional set of impulsive excitation primitives.

    Science.gov (United States)

    Sartori, Massimo; Gizzi, Leonardo; Lloyd, David G; Farina, Dario

    2013-01-01

    Human locomotion has been described as being generated by an impulsive (burst-like) excitation of groups of musculotendon units, with timing dependent on the biomechanical goal of the task. Despite this view being supported by many experimental observations on specific locomotion tasks, it is still unknown if the same impulsive controller (i.e., a low-dimensional set of time-delayed excitastion primitives) can be used as input drive for large musculoskeletal models across different human locomotion tasks. For this purpose, we extracted, with non-negative matrix factorization, five non-negative factors from a large sample of muscle electromyograms in two healthy subjects during four motor tasks. These included walking, running, sidestepping, and crossover cutting maneuvers. The extracted non-negative factors were then averaged and parameterized to obtain task-generic Gaussian-shaped impulsive excitation curves or primitives. These were used to drive a subject-specific musculoskeletal model of the human lower extremity. Results showed that the same set of five impulsive excitation primitives could be used to predict the dynamics of 34 musculotendon units and the resulting hip, knee and ankle joint moments (i.e., NRMSE = 0.18 ± 0.08, and R (2) = 0.73 ± 0.22 across all tasks and subjects) without substantial loss of accuracy with respect to using experimental electromyograms (i.e., NRMSE = 0.16 ± 0.07, and R (2) = 0.78 ± 0.18 across all tasks and subjects). Results support the hypothesis that biomechanically different motor tasks might share similar neuromuscular control strategies. This might have implications in neurorehabilitation technologies such as human-machine interfaces for the torque-driven, proportional control of powered prostheses and orthoses. In this, device control commands (i.e., predicted joint torque) could be derived without direct experimental data but relying on simple parameterized Gaussian-shaped curves, thus decreasing the input drive

  3. Primitive neuroectodermal tumor presenting as a presacral mass: A rare case report with review of literature

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    Pradnya S Bhadarge

    2017-01-01

    Full Text Available Primitive neuroectodermal tumors (PNETs are a group of highly malignant small round cell tumor (SRCT of neuroectodermal origin. They exhibit a great diversity in their clinical manifestations and pathologic similarities with other SRCTs. PNET commonly occurs in the central nervous system, head and neck region, paravertebral region, pelvis, and lower extremities. PNET presenting as a presacral mass is very rare. We present a case of 65-year-old female patient presented with a mass in the abdomen. Exploratory laparotomy with excision of mass was carried out. Histopathology revealed the diagnosis of PNET. The rarity of PNET at presacral region prompted the description of this case.

  4. Heavy Metal Bioaccumulation in an Atypical Primitive Neuroectodermal Tumor of the Abdominal Wall.

    Science.gov (United States)

    Roncati, Luca; Gatti, Antonietta Morena; Capitani, Federico; Barbolini, Giuseppe; Maiorana, Antonio; Palmieri, Beniamino

    2015-01-01

    Heavy metals are able to interfere with the function of vital cellular components. Besides in trace heavy metals, which are essential at low concentration for humans, there are heavy metals with a well-known toxic and oncogenic potential. In this study, for the first time in literature, we report the unique adulthood case of an atypical primitive neuroectodermal tumor of the abdominal wall, diagnosed by histology and immunohistochemistry, with the molecular hybridization support. The neoplasia occurred in a patient chronically exposed to a transdermal delivery of heavy metal salts (aluminum and bismuth), whose intracellular bioaccumulation has been revealed by elemental microanalysis.

  5. An Efficient Primitive-Based Method to Recognize Online Sketched Symbols with Autocompletion

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    Wei Deng

    2015-01-01

    Full Text Available We present a new structural method of sketched symbol recognition, which aims to recognize a hand-drawn symbol before it is fully completed. It is invariant to scale, stroke number, and order. We also present two novel descriptors to represent the spatial distribution between two primitives. One is invariant to rotation and the other is not. Then a symbol is represented as a set of descriptors. The distance between the input symbol and the template one is calculated based on the assignment problem. Moreover, a fast nearest neighbor (NN search algorithm is proposed for recognition. The method achieves a satisfactory recognition rate in real time.

  6. Primitive neuroectodermal tumor or small cell carcinoma of the kidney, arare neoplasm: Case Report

    International Nuclear Information System (INIS)

    Radhi, A.; Ratnakar, K.S.; Al-Durazi, M.; Khalifa, F.

    2002-01-01

    Small cell carcinoma is a malignancy primarily recognized in thebronchopulmonary region. Extrapulmonary locations are extremely uncommon. Wereport here a case of renal tumor encountered in a 34-year-old female, withextensive metastases in liver, lung and bone. Histological examination wasmost compatible with primitive neuroectodermal tumor (PNET) small cellcarcinoma. There were negative immunohistochemical markers for cytokeratin,any hormonal peptides and epithelial membrane antigens, which is consistentwith the designation of neoplasm as PNET. Previously reported cases have allbeen in the elderly and, to the best of our knowledge, this is the first caseof proven PNET of the kidney described in a young female. (author)

  7. Molecular analysis of childhood primitive neuroectodermal tumors defines markers associated with poor outcome

    DEFF Research Database (Denmark)

    Scheurlen, W G; Schwabe, G C; Joos, S

    1998-01-01

    PURPOSE: The diagnostic and prognostic significance of well-defined molecular markers was investigated in childhood primitive neuroectodermal tumors (PNET). MATERIALS AND METHODS: Using microsatellite analysis, Southern blot analysis, and fluorescence in situ hybridization (FISH), 30 primary tumors......: In our study, amplification of c-myc was a poor-prognosis marker in PNET. LOH of chromosome 17p was associated with metastatic disease. Molecular analysis of primary tumors using these markers may be useful for stratification of children with PNET in future prospective studies. The other aberrations...... investigated were not of significant prognostic value, but may provide an entry point for future large-scale molecular studies....

  8. Interaction learning for dynamic movement primitives used in cooperative robotic tasks

    DEFF Research Database (Denmark)

    Kulvicius, Tomas; Biehl, Martin; Aein, Mohamad Javad

    2013-01-01

    Abstract Since several years dynamic movement primitives (DMPs) are more and more getting into the center of interest for flexible movement control in robotics. In this study we introduce sensory feedback together with a predictive learning mechanism which allows tightly coupled dual-agent systems...... to learn an adaptive, sensor-driven interaction based on DMPs. The coupled conventional (no-sensors, no learning) DMP-system automatically equilibrates and can still be solved analytically allowing us to derive conditions for stability. When adding adaptive sensor control we can show that both agents learn...

  9. Amino acid codes in mitochondria as possible clues to primitive codes

    Science.gov (United States)

    Jukes, T. H.

    1981-01-01

    Differences between mitochondrial codes and the universal code indicate that an evolutionary simplification has taken place, rather than a return to a more primitive code. However, these differences make it evident that the universal code is not the only code possible, and therefore earlier codes may have differed markedly from the previous code. The present universal code is probably a 'frozen accident.' The change in CUN codons from leucine to threonine (Neurospora vs. yeast mitochondria) indicates that neutral or near-neutral changes occurred in the corresponding proteins when this code change took place, caused presumably by a mutation in a tRNA gene.

  10. Primary Vaginal Extraosseous Ewing Sarcoma/Primitive Neuroectodermal Tumor with Cranial Metastasis

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    Chi-Man Yip

    2009-06-01

    Full Text Available Extraosseous Ewing sarcoma is now regarded as a member of the Ewing sarcoma/primitive neuroectodermal tumor (PNET family. It typically involves the soft tissues of the chest wall, pelvis, paravertebral region, abdominal wall, retroperitoneal region and extremities of children, adolescents and young adults, but it seldom occurs in the female genital tract. We report an extremely rare case of retrospective diagnosis of vaginal extraosseous Ewing sarcoma/PNET which metastasized to the right frontoparietal scalp, skull, and dura. Surgical resection, followed by adjuvant radiotherapy and chemotherapy resulted in a favourable clinical outcome. Both the vaginal and head tumors had similar light microscopic features supporting the diagnosis.

  11. Congenital Ewing's Sarcoma/Peripheral Primitive Neuroectodermal Tumor: A Case Report and Review of the Literature.

    Science.gov (United States)

    Jin, Shu-Guang; Jiang, Xiao-Ping; Zhong, Lin

    2016-10-01

    Ewing's sarcoma (EWS) and peripheral primitive neuroectodermal tumor (pPNET) are small round cell malignancies that develop in soft tissue and bone. They very rarely affect newborns. A diagnosis of EWS/pPNET depends mainly on immunohistochemistry and molecular/genetic assays. Since these tumors are highly aggressive, patient prognosis is typically very poor, and treatment remains a challenge. Here, we report a 13-day-old newborn diagnosed with congenital EWS/pPNET and describe its treatment. Copyright © 2014. Published by Elsevier B.V.

  12. Congenital Ewing's Sarcoma/Peripheral Primitive Neuroectodermal Tumor: A Case Report and Review of the Literature

    Directory of Open Access Journals (Sweden)

    Shu-Guang Jin

    2016-10-01

    Full Text Available Ewing's sarcoma (EWS and peripheral primitive neuroectodermal tumor (pPNET are small round cell malignancies that develop in soft tissue and bone. They very rarely affect newborns. A diagnosis of EWS/pPNET depends mainly on immunohistochemistry and molecular/genetic assays. Since these tumors are highly aggressive, patient prognosis is typically very poor, and treatment remains a challenge. Here, we report a 13-day-old newborn diagnosed with congenital EWS/pPNET and describe its treatment.

  13. The Pay-What-You-Want game: What can be learned from the experimental evidence on Dictator and Trust Games?

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    Greiff Matthias

    2017-03-01

    Full Text Available This paper introduces the Pay-What-You-Want game which represents the interaction between a buyer and a seller in a Pay-What-You-Want (PWYW situation. The PWYW game embeds the dictator game and the trust game as subgames. This allows us to use previous experimental studies with the dictator and the trust game to identify three factors that can influence the success of PWYW pricing in business practice: (i social context, (ii social information, and (iii deservingness. Only few cases of PWYW pricing for a longer period of time have been documented. By addressing repeated games, we isolate two additional factors which are likely to contribute to successful implementations of PWYW as a long term pricing strategy. These are (iv communication and (v the reduction of goal conflicts. The central contribution of this study is an attempt to bridge the gap between laboratory experiments and the research on PWYW pricing, which relies largely on evidence from the field. By reviewing the relevant experiments, this study identifies factors crucial for the success of PWYW pricing and provides guidance to developing long-term applications of PWYW pricing.

  14. TALEN/CRISPR-mediated eGFP knock-in add-on at the OCT4 locus does not impact differentiation of human embryonic stem cells towards endoderm.

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    Nicole A J Krentz

    Full Text Available Human embryonic stem cells (hESCs have great promise as a source of unlimited transplantable cells for regenerative medicine. However, current progress on producing the desired cell type for disease treatment has been limited due to an insufficient understanding of the developmental processes that govern their differentiation, as well as a paucity of tools to systematically study differentiation in the lab. In order to overcome these limitations, cell-type reporter hESC lines will be required. Here we outline two strategies using Transcription Activator Like Effector Nucleases (TALENs and Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR-CRISPR-Associated protein (Cas to create OCT4-eGFP knock-in add-on hESC lines. Thirty-one and forty-seven percent of clones were correctly modified using the TALEN and CRISPR-Cas9 systems, respectively. Further analysis of three correctly targeted clones demonstrated that the insertion of eGFP in-frame with OCT4 neither significantly impacted expression from the wild type allele nor did the fusion protein have a dramatically different biological stability. Importantly, the OCT4-eGFP fusion was easily detected using microscopy, flow cytometry and western blotting. The OCT4 reporter lines remained equally competent at producing CXCR4+ definitive endoderm that expressed a panel of endodermal genes. Moreover, the genomic modification did not impact the formation of NKX6.1+/SOX9+ pancreatic progenitor cells following directed differentiation. In conclusion, these findings demonstrate for the first time that CRISPR-Cas9 can be used to modify OCT4 and highlight the feasibility of creating cell-type specific reporter hESC lines utilizing genome-editing tools that facilitate homologous recombination.

  15. Navigation Strategies for Primitive Solar System Body Rendezvous and Proximity Operations

    Science.gov (United States)

    Getzandanner, Kenneth M.

    2011-01-01

    A wealth of scientific knowledge regarding the composition and evolution of the solar system can be gained through reconnaissance missions to primitive solar system bodies. This paper presents analysis of a baseline navigation strategy designed to address the unique challenges of primitive body navigation. Linear covariance and Monte Carlo error analysis was performed on a baseline navigation strategy using simulated data from a· design reference mission (DRM). The objective of the DRM is to approach, rendezvous, and maintain a stable orbit about the near-Earth asteroid 4660 Nereus. The outlined navigation strategy and resulting analyses, however, are not necessarily limited to this specific target asteroid as they may he applicable to a diverse range of mission scenarios. The baseline navigation strategy included simulated data from Deep Space Network (DSN) radiometric tracking and optical image processing (OpNav). Results from the linear covariance and Monte Carlo analyses suggest the DRM navigation strategy is sufficient to approach and perform proximity operations in the vicinity of the target asteroid with meter-level accuracy.

  16. Boltzmann's dynamic on the primitive earth about 3.9 billion years ago

    International Nuclear Information System (INIS)

    Matsuno, Koichiro

    1995-01-01

    An evolutionary significant event that could have happened on the primitive earth would be a process of enhancing energy concentrations locally. Once the concentrated energy be released, it could drive various molecular association and dissociation. We have examined, both theoretically and experimentally, a possibility of forming such microscopic heat engines feeding upon the then available thermal environment. Theoretically, Boltzmann's dynamics of molecules that would lose their memory of pas collisions with others is found to uphold those molecules that could feed upon thermal energy if the thermal environment would fluctuate through, for instance, a diurnal cycle. Experimentally, thermal heterocomplex molecules from amino acids, that could have been ubiquitous on the primitive earth, are shown to carry with themselves a wide variety of quasi-stable states such that they could remain in excited states for a considerable period of time even if the temperature of the thermal environment is lowered. The stored energy in these excited states, once released, can be utilized as a factor for driving various molecular association and dissociation. (author). Abstract only

  17. Retained primitive reflexes: Perceptions of parents who have used Rhythmic Movement Training with their children.

    Science.gov (United States)

    Grigg, Tessa M; Fox-Turnbull, Wendy; Culpan, Ian

    2018-01-01

    This article reports on a qualitative phenomenological research project that investigated the use of Rhythmic Movement Training (RMT) as an intervention for retained primitive reflexes. Participants were from seven families who each had a child between the ages of 7 years and 12 years. Through semi-structured interviews, parents described their reasons for seeking additional help with their child's development issues. They talked about finding RMT, using RMT within their family routine and their views on the costs and the benefits they experienced, both financial and time. While there has been a small amount of research into movement programmes targeting retained primitive reflexes, to date there appears to have been no studies completed on RMT. The data collected described searches for help, the stress and frustrations associated with the search and the range of interventions these parents tried. The families in this research found that RMT was easy to use within their daily routine and that it was a cost-effective, low-impact intervention. The families noticed a range of benefits for children who had completed the movements. The findings provide encouraging evidence to proceed with further study that will investigate the academic, social and emotional development of children using RMT.

  18. CD71(high) population represents primitive erythroblasts derived from mouse embryonic stem cells.

    Science.gov (United States)

    Chao, Ruihua; Gong, Xueping; Wang, Libo; Wang, Pengxiang; Wang, Yuan

    2015-01-01

    The CD71/Ter119 combination has been widely used to reflect dynamic maturation of erythrocytes in vivo. However, because CD71 is expressed on all proliferating cells, it is unclear whether it can be utilized as an erythrocyte-specific marker during differentiation of embryonic stem cells (ESCs). In this study, we revealed that a population expressing high level of CD71 (CD71(high)) during mouse ESC differentiation represented an in vitro counterpart of yolk sac-derived primitive erythroblasts (EryPs) isolated at 8.5days post coitum. In addition, these CD71(high) cells went through "maturational globin switching" and enucleated during terminal differentiation in vitro that were similar to the yolk sac-derived EryPs in vivo. We further demonstrated that the formation of CD71(high) population was regulated differentially by key factors including Scl, HoxB4, Eaf1, and Klf1. Taken together, our study provides a technical advance that allows efficient segregation of EryPs from differentiated ESCs in vitro for further understanding molecular regulation during primitive erythropoiesis. Copyright © 2014. Published by Elsevier B.V.

  19. QCAPUF: QCA-based physically unclonable function as a hardware security primitive

    Science.gov (United States)

    Abutaleb, M. M.

    2018-04-01

    Physically unclonable functions (PUFs) are increasingly used as innovative security primitives to provide the hardware authentication and identification as well as the secret key generation based on unique and random variations in identically fabricated devices. Security and low power have appeared to become two crucial necessities to modern designs. As an emerging nanoelectronic technology, a quantum-dot cellular automata (QCA) can achieve ultra-low power consumption as well as an extremely small area for implementing digital designs. However, there are various classes of permanent defects that can happen during the manufacture of QCA devices. The recent extensive research has been focused on how to eliminate errors in QCA structures resulting from fabrication variances. By a completely different vision, to turn this disadvantage into an advantage, this paper presents a novel QCA-based PUF (QCAPUF) architecture to exploit the unique physical characteristics of fabricated QCA cells in order to produce different hardware fingerprint instances. This architecture is composed of proposed logic and interconnect blocks that have critical vulnerabilities and perform unexpected logical operations. The behaviour of QCAPUF is thoroughly analysed through physical relations and simulations. Results confirm that the proposed QCAPUF has state of the art PUF characteristics in the QCA technology. This paper will serve as a basis for further research into QCA-based hardware security primitives and applications.

  20. Neuropilin-2 genomic elements drive cre recombinase expression in primitive blood, vascular and neuronal lineages.

    Science.gov (United States)

    Wiszniak, Sophie; Scherer, Michaela; Ramshaw, Hayley; Schwarz, Quenten

    2015-11-01

    We have established a novel Cre mouse line, using genomic elements encompassing the Nrp2 locus, present within a bacterial artificial chromosome clone. By crossing this Cre driver line to R26R LacZ reporter mice, we have documented the temporal expression and lineage traced tissues in which Cre is expressed. Nrp2-Cre drives expression in primitive blood cells arising from the yolk sac, venous and lymphatic endothelial cells, peripheral sensory ganglia, and the lung bud. This mouse line will provide a new tool to researchers wishing to study the development of various tissues and organs in which this Cre driver is expressed, as well as allow tissue-specific knockout of genes of interest to study protein function. This work also presents the first evidence for expression of Nrp2 protein in a mesodermal progenitor with restricted hematopoietic potential, which will significantly advance the study of primitive erythropoiesis. genesis 53:709-717, 2015. © 2015 Wiley Periodicals, Inc. © 2015 Wiley Periodicals, Inc.

  1. Dispossessing Urbanization: Urban Marxism in the Face of the Problem of Primitive Accumulation

    Directory of Open Access Journals (Sweden)

    Piotr Juskowiak

    2015-04-01

    Full Text Available The article is a complex attempt to present the achievements of the broadly understood urban Marxism in the field of reinterpretation of the classic concept from the cards of Capital – “primitive accumulation”. Drawing on theories of such scholars as David Harvey (“accumulation by dispossession” or Saskia Sassen (“expulsions”, the author points to the possible ways to operationalize the concept of “dispossessing urbanization”. Inspired by the theorizations of autonomist Marxists (Antonio Negri, Sandro Mezzadra, Massimo De Angelis, he proposes to see it as a relatively new and increasingly important dispostif that allows not only to improve traditional methods of enclosures and construct entirely new ones, but also to instrumentalize urban cultures which seems unlikely for the historical versions of primitive accumulation. This theoretical inspiration leads him also to highlight another gap in the accumulation by dispossession theory, namely the lack of sufficient reflection on the production of subjectivity processes which seem constitutive for the broad set of dispossessing practices.

  2. Fanconi anemia genes are highly expressed in primitive CD34+ hematopoietic cells

    Directory of Open Access Journals (Sweden)

    Brodeur Isabelle

    2003-06-01

    Full Text Available Abstract Background Fanconi anemia (FA is a complex recessive genetic disease characterized by progressive bone marrow failure (BM and a predisposition to cancer. We have previously shown using the Fancc mouse model that the progressive BM failure results from a hematopoietic stem cell defect suggesting that function of the FA genes may reside in primitive hematopoietic stem cells. Methods Since genes involved in stem cell differentiation and/or maintenance are usually regulated at the transcription level, we used a semiquantitative RT-PCR method to evaluate FA gene transcript levels in purified hematopoietic stem cells. Results We show that most FA genes are highly expressed in primitive CD34-positive and negative cells compared to lower levels in more differentiated cells. However, in CD34- stem cells the Fancc gene was found to be expressed at low levels while Fancg was undetectable in this population. Furthermore, Fancg expression is significantly decreased in Fancc -/- stem cells as compared to wild-type cells while the cancer susceptibility genes Brca1 and Fancd1/Brac2 are upregulated in Fancc-/- hematopoietic cells. Conclusions These results suggest that FA genes are regulated at the mRNA level, that increased Fancc expression in LTS-CD34+ cells correlates with a role at the CD34+ differentiation stage and that lack of Fancc affects the expression of other FA gene, more specifically Fancg and Fancd1/Brca2, through an unknown mechanism.

  3. Mid-infrared study of the molecular structure variability of insoluble organic matter from primitive chondrites

    Science.gov (United States)

    Orthous-Daunay, F.-R.; Quirico, E.; Beck, P.; Brissaud, O.; Dartois, E.; Pino, T.; Schmitt, B.

    2013-03-01

    Insoluble Organic Matter (IOM) found in primitive meteorites was formed in the Early Solar System and subsequently processed on the parent asteroids. The location, temporal sequence and processes of formation of this IOM are still a matter of debate. In particular, there is no consensus on the actual effect of post-accretional aqueous alteration processes on the chemical composition and structure of IOM. In the most primitive chondrites (types 1 and 2), these alterations have so far been either neglected or generically assigned to oxidation processes induced by fluid circulation. A series of IOM samples extracted from 14 chondrites with extensively documented post-accretional histories have been studied by infrared spectroscopy. Aqueous alteration shows no detectable effect on the chemical composition and structure of IOM within or across chondrite classes. Indeed, the most effective post-accretional process appears to be a high-temperature short-duration heating event and concerns essentially type 2 chondrites. In any case, post-accretional processes cannot account for all the chemical and structural variations of IOM. Chondrites from the CI, CR and CM classes accreted IOM precursors with moderately variable compositions, suggesting a chemical heterogeneity of the protosolar disk. The 3.4 μm band, and possibly its overtones and combinations in the near-infrared range, appear to be tracer(s) of the chemical class and possibly of surface heating processes triggered by impacts.

  4. Classical and molecular cytogenetic characterization of Agonostomus monticola, a primitive species of Mugilidae (Mugiliformes).

    Science.gov (United States)

    Nirchio, Mauro; Oliveira, Claudio; Ferreira, Irani A; Martins, Cesar; Rossi, Anna Rita; Sola, Luciana

    2009-01-01

    This study reports the first description of the karyotype of Agonostomus monticola, a species belonging to a genus which is considered to be the most primitive among living mugilid fish. Specimens from Panama and Venezuela were cytogenetically analysed by conventional chromosome banding (Ag and base-specific-fluorochrome staining, C-banding) and by fluorescent in situ hybridization (FISH). Agonostomus monticola showed a chromosome complement of 2n = 48, composed of 23 acrocentric and one subtelocentric chromosome pairs and a pericentromeric distribution of the C-positive heterochromatin in all chromosomes. Major ribosomal genes were found to be located on the short arms of the subtelocentric chromosome pair number 24 and minor ribosomal genes in a paracentromeric position of a single medium-sized chromosome pair. All these observed cytogenetic features are similar to those previously described in four representatives of two genera, Liza and Chelon, which are considered to be among the most advanced in the family. Thus, this karyotypic form might represent the plesiomorphic condition for the mullets. This hypothesis regarding the plesiomorphic condition, if confirmed, would shed new light on the previously inferred cytotaxonomic relationships for the studied species of Mugilidae, because the karyotype with 48 acrocentric chromosomes, which has been so far regarded as primitive for the family, would have to be considered as derived.

  5. Conservative multimodal management of a primitive neuroectodermal tumor of the thyroid

    Directory of Open Access Journals (Sweden)

    Juliette Haudebourg

    2013-04-01

    Full Text Available Primitive neuroectodermal tumors (PNET represent 1% of sarcomas. Head and neck peripheral PNETs have an intermediate prognosis between abdominopelvic disease and extremities. We here report the case of a 40-year old male who presented with primitive neuroectodermal tumor of the thyroid and was treated by multimodal treatment, including surgery, chemotherapy and intermediate dose radiotherapy. The patient is alive and fit with a functional larynx at 27 months. Multimodal treatments yield five-year survival rates of about 60%. Major drug regimens use vincristine, doxorubicin, ifosfamide or cyclophosphamide, dactinomycin and/or etoposide. Complete surgical excision is undertaken whenever possible to improve long-term survival. However, the relative radiosensitivity of tumors of the Ewing family, suggest multimodal treatment including adjuvant conformal radiotherapy in case of positive margins or poor response to chemotherapy rather than resection with 2-3 cm margins, which would imply laryngeal sacrifice for thyroid tumors. The role of expert rare tumor networks is crucial for optimal decision-making and management of such rare tumors on a case by case basis.

  6. Hierarchical HMM based learning of navigation primitives for cooperative robotic endovascular catheterization.

    Science.gov (United States)

    Rafii-Tari, Hedyeh; Liu, Jindong; Payne, Christopher J; Bicknell, Colin; Yang, Guang-Zhong

    2014-01-01

    Despite increased use of remote-controlled steerable catheter navigation systems for endovascular intervention, most current designs are based on master configurations which tend to alter natural operator tool interactions. This introduces problems to both ergonomics and shared human-robot control. This paper proposes a novel cooperative robotic catheterization system based on learning-from-demonstration. By encoding the higher-level structure of a catheterization task as a sequence of primitive motions, we demonstrate how to achieve prospective learning for complex tasks whilst incorporating subject-specific variations. A hierarchical Hidden Markov Model is used to model each movement primitive as well as their sequential relationship. This model is applied to generation of motion sequences, recognition of operator input, and prediction of future movements for the robot. The framework is validated by comparing catheter tip motions against the manual approach, showing significant improvements in the quality of catheterization. The results motivate the design of collaborative robotic systems that are intuitive to use, while reducing the cognitive workload of the operator.

  7. A Primitive Memory System for Attention Deployments: Some Recent Challenges and Their Resolution

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    Árni Kristjánsson

    2011-05-01

    Full Text Available In the past my colleagues and I have presented evidence for the existence of a primitive memory for attention deployments. This memory system orients attention to features and locations of recent behavioral importance. A large part of the proposal is that the memory system facilitates attentional selection of features in the environment such as color, orientation, etc. I will review the findings behind these proposals. The bulk of this evidence comes from studies of history effects in vision, such as priming of visual search, and implicit learning in exogenously cued attention shifts. In addition, recent challenges to this view will be discussed (in particular, arguments that the facilitation from repetition in visual search tasks occurs at a relatively late stage of perceptual processing. Our recent investigations of these proposals suggest that there is indeed evidence for higher-level priming effects in visual search under certain conditions, but those findings do not challenge the basic proposals regarding the primitive memory system, since the evidence for feature-specific facilitation is robust.

  8. Oct4 is required ~E7.5 for proliferation in the primitive streak.

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    Brian DeVeale

    2013-11-01

    Full Text Available Oct4 is a widely recognized pluripotency factor as it maintains Embryonic Stem (ES cells in a pluripotent state, and, in vivo, prevents the inner cell mass (ICM in murine embryos from differentiating into trophectoderm. However, its function in somatic tissue after this developmental stage is not well characterized. Using a tamoxifen-inducible Cre recombinase and floxed alleles of Oct4, we investigated the effect of depleting Oct4 in mouse embryos between the pre-streak and headfold stages, ~E6.0-E8.0, when Oct4 is found in dynamic patterns throughout the embryonic compartment of the mouse egg cylinder. We found that depletion of Oct4 ~E7.5 resulted in a severe phenotype, comprised of craniorachischisis, random heart tube orientation, failed turning, defective somitogenesis and posterior truncation. Unlike in ES cells, depletion of the pluripotency factors Sox2 and Oct4 after E7.0 does not phenocopy, suggesting that ~E7.5 Oct4 is required within a network that is altered relative to the pluripotency network. Oct4 is not required in extraembryonic tissue for these processes, but is required to maintain cell viability in the embryo and normal proliferation within the primitive streak. Impaired expansion of the primitive streak occurs coincident with Oct4 depletion ∼E7.5 and precedes deficient convergent extension which contributes to several aspects of the phenotype.

  9. A Novel Non-Invasive Selection Criterion for the Preservation of Primitive Dutch Konik Horses.

    Science.gov (United States)

    May-Davis, Sharon; Brown, Wendy Y; Shorter, Kathleen; Vermeulen, Zefanja; Butler, Raquel; Koekkoek, Marianne

    2018-02-01

    The Dutch Konik is valued from a genetic conservation perspective and also for its role in preservation of natural landscapes. The primary management objective for the captive breeding of this primitive horse is to maintain its genetic purity, whilst also maintaining the nature reserves on which they graze. Breeding selection has traditionally been based on phenotypic characteristics consistent with the breed description, and the selection of animals for removal from the breeding program is problematic at times due to high uniformity within the breed, particularly in height at the wither, colour (mouse to grey dun) and presence of primitive markings. With the objective of identifying an additional non-invasive selection criterion with potential uniqueness to the Dutch Konik, this study investigates the anatomic parameters of the distal equine limb, with a specific focus on the relative lengths of the individual splint bones. Post-mortem dissections performed on distal limbs of Dutch Konik ( n = 47) and modern domesticated horses ( n = 120) revealed significant differences in relation to the length and symmetry of the 2nd and 4th Metacarpals and Metatarsals. Distal limb characteristics with apparent uniqueness to the Dutch Konik are described which could be an important tool in the selection and preservation of the breed.

  10. Tubulin post-translational modifications in the primitive protist Trichomonas vaginalis.

    Science.gov (United States)

    Delgado-Viscogliosi, P; Brugerolle, G; Viscogliosi, E

    1996-01-01

    Using several specific monoclonal antibodies, we investigated the occurrence and distribution of different post-translationally modified tubulin during interphase and division of the primitive flagellated protist Trichomonas vaginalis. Immunoblotting and immunofluorescence experiments revealed that interphasic microtubular structures of T. vaginalis contained acetylated and glutamylated but non-tyrosinated and non-glycylated [Brugerolle and Adoutte, 1988: Bio Systems 21: 255-268] tubulin. Immunofluorescence studies performed on dividing cells showed that the extranuclear mitotic spindle (or paradesmosis) was acetylated and glutamylated, which contrast with the ephemeral nature of this structure. Newly formed short axostyles also contained acetylated and glutamylated tubulin suggesting that both post-translational modifications might take place very early after assembly of microtubular structures. Our results indicate that acetylation and glutamylation of tubulin appeared early in the history of eukaryotes and could reflect the occurrence of post-translational modifications of tubulin in the primitive eukaryotic cells. These cells probably had a highly ordered cross-linked microtubular cytoskeleton in which microtubules showed a low level of subunit exchange dynamics.

  11. The neonatal marmoset monkey ovary is very primitive exhibiting many oogonia

    Science.gov (United States)

    Fereydouni, B; Drummer, C; Aeckerle, N; Schlatt, S; Behr, R

    2014-01-01

    Oogonia are characterized by diploidy and mitotic proliferation. Human and mouse oogonia express several factors such as OCT4, which are characteristic of pluripotent cells. In human, almost all oogonia enter meiosis between weeks 9 and 22 of prenatal development or undergo mitotic arrest and subsequent elimination from the ovary. As a consequence, neonatal human ovaries generally lack oogonia. The same was found in neonatal ovaries of the rhesus monkey, a representative of the old world monkeys (Catarrhini). By contrast, proliferating oogonia were found in adult prosimians (now called Strepsirrhini), which is a group of ‘lower’ primates. The common marmoset monkey (Callithrix jacchus) belongs to the new world monkeys (Platyrrhini) and is increasingly used in reproductive biology and stem cell research. However, ovarian development in the marmoset monkey has not been widely investigated. Herein, we show that the neonatal marmoset ovary has an extremely immature histological appearance compared with the human ovary. It contains numerous oogonia expressing the pluripotency factors OCT4A, SALL4, and LIN28A (LIN28). The pluripotency factor-positive germ cells also express the proliferation marker MKI67 (Ki-67), which has previously been shown in the human ovary to be restricted to premeiotic germ cells. Together, the data demonstrate the primitiveness of the neonatal marmoset ovary compared with human. This study may introduce the marmoset monkey as a non-human primate model to experimentally study the aspects of primate primitive gonad development, follicle assembly, and germ cell biology in vivo. PMID:24840529

  12. Peripheral primitive neuroendocrine tumor of the chest wall—A case report with pathological correlation

    Directory of Open Access Journals (Sweden)

    Jidi Gao, MD

    2018-04-01

    Full Text Available Primitive neuroectodermal tumor is a high-grade malignant tumor originating from the neural crest and neuroectoderm, which can be subdivided into central and peripheral categories. Peripheral primitive neuroectodermal tumor is thought to be identical to Ewing's sarcoma, and falls under a broader category of Ewing's sarcoma family of tumors. Very rarely, it may present without osseous involvement, known as extraosseous Ewing's sarcoma. Here we present a case of a 38-year-old woman, who presented with several-month history of a slow-growing chest wall mass, initially thought to be a breast mass. The mass was diagnosed as extraosseous Ewing's sarcoma upon tissue biopsy. The patient was started on a dose-intensified neoadjuvant therapy, based on protocol from pediatric population given rarity of this tumor in the adult population. While the patient was initially planned for surgical resection, the tumor showed excellent response to chemotherapy on follow-up imaging, and radiation therapy was elected in lieu of resection. Keywords: Chest wall tumors, Peripheral PNET, Ewing's sarcoma

  13. EUS-FNA for the Diagnosis of Retroperitoneal Primitive Neuroectodermal Tumor

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    Aijaz A. Sofi

    2011-01-01

    Full Text Available Primitive neuroectodermal tumor (PNET is a rare “small round blue cell tumor” that is diagnosed by open biopsy or percutaneous biopsy of the lesion under radiologic guidance. In this case report, we present a novel approach to the diagnosis of a retroperitoneal PNET by endoscopic ultrasound- (EUS- guided fine needle aspiration (FNA. A 35-year-old man presented with the history of left-sided flank pain and swelling of 3-weeks duration. Computerized tomography (CT scan of his abdomen revealed a 12.8 × 13 × 12.5 cm cystic and solid mass arising from the retroperitoneum and displacing the third and fourth portions of the duodenum. He underwent EUS which revealed a well-circumscribed heterogeneous mass abutting the inferior portion of the stomach. EUS-FNA of the mass revealed malignant cells consistent with primitive neuroectodermal tumor (PNET/Ewing's sarcoma. EUS-guided FNA is an appropriate technique for diagnosing retroperitoneal PNET/Ewing's sarcoma.

  14. Transgression, Nostalgia, Order: Representation of the Primitive in Émile Zola's La Terre and Knut Hamsun's Markens grøde

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    Riikka Rossi

    2012-03-01

    Full Text Available This article examines the representation of the primitive in two peasant novels, Émile Zola's La Terre (1887, trans. as The Earth and Knut Hamsun's Markens grøde (1917, trans. as Growth of the Soil. The concept of the primitive crosses a wide range of issues that were central to naturalist and decadent literature at the turn of the twentieth century, from unconscious instincts to the fascination with exotic cultures. It thus offers a fruitful medium for the comparative reading of French and Nordic fiction of the era. I especially focus on analysing the diverse, representative practices of Zola's and Hamsun's works, which betray stylistic differences in their portrayal of the primitive. I suggest that by describing the primitive as a vital, transgressive force that even turns against itself - against nature - Zola's La Terre creates a decadent version of the primitive, which, instead of a "serious", naturalistic portrayal of everyday life, is drawn to the brutal, instinctive primitive and uses the primitive to create vital forces of transgression. Hamsun's neo-naturalist novel, in turn, reconfigures the naturalist themes in a new form and envisions a fusion of the Darwinian, naturalistic primitive and the Romantic cult of innocent primordiality, suggesting the primitive lifestyle as a nostalgic return to a pre-modern lifestyle and a turn away from the degeneration of modernity.

  15. Aesthetic primitivism revisited: The global diaspora of ‘primitive art’ and the rise of indigenous modernisms

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    Ruth B. Phillips

    2015-06-01

    Full Text Available This paper examines the global export of the construct of primitive art which developed in Europe in the early-twentieth century and the catalytic role it played in the emergence of modernist art forms produced by Indigenous peoples. It argues for the need to distinguish between sociological primitivism grounded in cultural evolutionist theory and the aesthetic primitivism promoted by artists, ethnologists and patrons who admired and appropriated the traditional arts of non-Western peoples classified as 'primitive.' Case studies of two refugees from Nazi Europe, German ethnologist Leonhard Adam and Austrian artist George Swinton, demonstrate the tension between received understandings of primitive art and these men's growing awareness, following emigration, of Indigenous modernities. It also led to their active promotion of modern Australian Aboriginal and Inuit arts, despite the undoubted links between aesthetic primitivism and the oppressive assimilationist policies justified through sociological primitivism.

  16. The oxytocin receptor (OXTR contributes to prosocial fund allocations in the dictator game and the social value orientations task.

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    Salomon Israel

    Full Text Available BACKGROUND: Economic games observe social decision making in the laboratory that involves real money payoffs. Previously we have shown that allocation of funds in the Dictator Game (DG, a paradigm that illustrates costly altruistic behavior, is partially determined by promoter-region repeat region variants in the arginine vasopressin 1a receptor gene (AVPR1a. In the current investigation, the gene encoding the related oxytocin receptor (OXTR was tested for association with the DG and a related paradigm, the Social Values Orientation (SVO task. METHODOLOGY/PRINCIPAL FINDINGS: Association (101 male and 102 female students using a robust-family based test between 15 single tagging SNPs (htSNPs across the OXTR was demonstrated with both the DG and SVO. Three htSNPs across the gene region showed significant association with both of the two games. The most significant association was observed with rs1042778 (p = 0.001. Haplotype analysis also showed significant associations for both DG and SVO. Following permutation test adjustment, significance was observed for 2-5 locus haplotypes (p<0.05. A second sample of 98 female subjects was subsequently and independently recruited to play the dictator game and was genotyped for the three significant SNPs found in the first sample. The rs1042778 SNP was shown to be significant for the second sample as well (p = 0.004, Fisher's exact test. CONCLUSIONS: The demonstration that genetic polymorphisms for the OXTR are associated with human prosocial decision making converges with a large body of animal research showing that oxytocin is an important social hormone across vertebrates including Homo sapiens. Individual differences in prosocial behavior have been shown by twin studies to have a substantial genetic basis and the current investigation demonstrates that common variants in the oxytocin receptor gene, an important element of mammalian social circuitry, underlie such individual differences.

  17. Fate of the three embryonic dural sinuses in infants: the primitive tentorial sinus, occipital sinus, and falcine sinus.

    Science.gov (United States)

    Mizutani, Katsuhiro; Miwa, Tomoru; Akiyama, Takenori; Sakamoto, Yoshiaki; Fujiwara, Hirokazu; Yoshida, Kazunari

    2018-03-01

    The primitive tentorial, occipital, and falcine sinuses are thought to attain the adult pattern or regress between the fetal stage and adulthood. The anatomy of these three primitive dural sinuses has seldom been studied in the infant population, and it remains unclear when these dural sinuses reach the adult condition. Using computed tomography digital subtraction venography (CT-DSV), we analyzed the anatomy of these embryonic dural sinuses in infants. We included 13 infants who underwent CT-DSV prior to neurosurgery and 35 cases with unruptured cerebral aneurysms as normal adult controls. Three embryonic dural sinuses, i.e., the primitive tentorial, occipital, and falcine sinuses, were retrospectively analyzed in CT-DSV images of infants and adults. We also analyzed the drainage patterns of the superficial middle cerebral vein (SMCV), determined by the connection between the primitive tentorial sinus and the cavernous sinus. The primitive tentorial, occipital, and falcine sinuses were present in 15.4%, 46.2%, and none of the infants, respectively, and in 10.0, 8.6, and 2.9% of the adults, respectively. The difference in SMCV draining pattern between infants and adults was insignificant. The incidence of the occipital sinus was significantly higher in infants than in adults. The connection between the primitive tentorial sinus and the cavernous sinus appears to be established before birth. The occipital sinus is formed at the embryonic stage and mostly regresses after infancy. The falcine sinus is usually obliterated prenatally. Our findings form the basis for interventions by pediatric interventional neuroradiologists and neurosurgeons.

  18. Phase diagram of the restricted primitive model: charge-ordering instability

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    O.V.Patsahan

    2004-01-01

    Full Text Available We study the phase behaviour of the restricted primitive model (RPM using a microscopic approach based on the method of collective variables with a reference system. Starting from the Hamiltonian of the RPM we derive the functional of the grand partition function given in terms of the two collective variables: the collective variables ρk and ck describing fluctuations of the total number density and charge density, respectively. Within the framework of the Gaussian approximation we found the boundary of stability with respect to fluctuations of the charge density. It is shown that due to the approximated character of the theory the boundary of stability is very sensitive to the particular choice of the long-range part of potential inside the hard core. This point is discussed in more detail.

  19. Computer simulations of the restricted primitive model at very low temperature and density

    International Nuclear Information System (INIS)

    Valeriani, Chantal; Camp, Philip J; Zwanikken, Jos W; Van Roij, Rene; Dijkstra, Marjolein

    2010-01-01

    The problem of successfully simulating ionic fluids at low temperature and low density states is well known in the simulation literature: using conventional methods, the system is not able to equilibrate rapidly due to the presence of strongly associated cation-anion pairs. In this paper we present a numerical method for speeding up computer simulations of the restricted primitive model (RPM) at low temperatures (around the critical temperature) and at very low densities (down to 10 -10 σ -3 , where σ is the ion diameter). Experimentally, this regime corresponds to typical concentrations of electrolytes in nonaqueous solvents. As far as we are aware, this is the first time that the RPM has been equilibrated at such extremely low concentrations. More generally, this method could be used to equilibrate other systems that form aggregates at low concentrations.

  20. Dynamic contrast enhanced MRI study of primary primitive neuroectodermal tumor in the thoracic spine

    International Nuclear Information System (INIS)

    Chen Yu; Xu Jianmin; Li Ying; Zhang Jingzhong; Zhu Jing

    2004-01-01

    Objective: To investigate the value of dynamic contrast-enhanced MR imaging in the diagnosis and differentiation of primitive neuroectodermal tumor (PNET) in the thoracic spine. Methods: The dynamic contrast-enhanced MR imaging of 2 patients (3 times) with PNET in the thoracic spine proved by surgery and pathology were prospectively studied. Results: In the curves of SI-time and CER-time, PNET in the thoracic spine showed a rapid rise to the peak between 60 s and 120 s, then the flat level was kept and no obvious decline was detected after about 3.5 minute. Conclusion: Dynamic contrast-enhanced MRI can help to make the diagnosis and differential diagnosis for PNET in the thoracic spine, offer reliable information for the choice of clinical management, and predict the prognosis

  1. Cooling and quasi-static contraction of the primitive solar nebula after gas accretion

    International Nuclear Information System (INIS)

    Watanabe, Seichiro; Nakagawa, Yoshitsugu; Nakazawa, Kiyoshi

    1990-01-01

    The evolution of the primitive solar nebula in the quasi-static contraction phase where the nebula cools down toward the thermal steady state is studied. The solar irradiation onto the nebula keeps the surface temperature constant, so that the convective ozone retreats from the surface as the nebula cools. Thus if thermal convection is the only source of turbulence, convection will quiet down in an early time of the cooling. Afterward, the nebula evolves toward an isothermal structure in a time scale of 1000 yr. The cooling rates in the vicinity of the midplate at 1 AU are 0.003 K/hr at T(c) = 1000 K and 3 x 10 to the -5th K/hr at T(c) = 300 K for the standard model. If some turbulence exists irrespective of convection, convection may continue for sufficiently strong turbulent heating. 39 refs

  2. Chemistry of primitive solar material. [nebular hypothesis of planetary systems formation

    Science.gov (United States)

    Barshay, S. S.; Lewis, J. S.

    1976-01-01

    The paper reviews chemical processes that occurred in the cooler outer regions of the primitive solar nebula (PSN) at the time of intimate chemical contact between the preplanetary condensate and the nebular gas. The elemental composition of the PSN is discussed, the 15 most abundant elements in it are listed, and numerical models of it are examined. Various condensation models are described and tested against observed properties of the planets, their satellites, and the asteroids. The chemistry of abundant volatile elements in the PSN is investigated along with stability limits of graphite in a solar-composition gas, regions of dominance of the most abundant carbon-containing gas species in the same gas, and implications of the moon's composition for its origin. Some theories that have been proposed as alternatives to the condensation models are noted.

  3. Calculation Scheme Based on a Weighted Primitive: Application to Image Processing Transforms

    Directory of Open Access Journals (Sweden)

    Gregorio de Miguel Casado

    2007-01-01

    Full Text Available This paper presents a method to improve the calculation of functions which specially demand a great amount of computing resources. The method is based on the choice of a weighted primitive which enables the calculation of function values under the scope of a recursive operation. When tackling the design level, the method shows suitable for developing a processor which achieves a satisfying trade-off between time delay, area costs, and stability. The method is particularly suitable for the mathematical transforms used in signal processing applications. A generic calculation scheme is developed for the discrete fast Fourier transform (DFT and then applied to other integral transforms such as the discrete Hartley transform (DHT, the discrete cosine transform (DCT, and the discrete sine transform (DST. Some comparisons with other well-known proposals are also provided.

  4. A three-dimensional spectral element model for the solution of the hydrostatic primitive equations

    CERN Document Server

    Iskandarani, M; Levin, J C

    2003-01-01

    We present a spectral element model to solve the hydrostatic primitive equations governing large-scale geophysical flows. The highlights of this new model include unstructured grids, dual h-p paths to convergence, and good scalability characteristics on present day parallel computers including Beowulf-class systems. The behavior of the model is assessed on three process-oriented test problems involving wave propagation, gravitational adjustment, and nonlinear flow rectification, respectively. The first of these test problems is a study of the convergence properties of the model when simulating the linear propagation of baroclinic Kelvin waves. The second is an intercomparison of spectral element and finite-difference model solutions to the adjustment of a density front in a straight channel. Finally, the third problem considers the comparison of model results to measurements obtained from a laboratory simulation of flow around a submarine canyon. The aforementioned tests demonstrate the good performance of th...

  5. Coordinates Analyses of Hydrated Interplanetary Dust Particles: Samples of Primitive Solar System Bodies

    Science.gov (United States)

    Keller, L. P.; Snead, C.; McKeegan, K. D.

    2016-01-01

    Interplanetary dust particles (IDPs) collected in the stratosphere fall into two major groups: an anhydrous group termed the "chondritic-porous (CP) IDPs and a hydrated group, the "chondritic-smooth (CS) IDPs, although rare IDPs with mineralogies intermediate between these two groups are known [1]. The CP-IDPs are widely believed to be derived from cometary sources [e.g. 2]. The hydrated CS-IDPs show mineralogical similarities to heavily aqueously altered carbonaceous chondrites (e.g. CI chondrites), but only a few have been directly linked to carbonaceous meteorite parent bodies [e.g. 3, 4]. Most CS-IDPs show distinct chemical [5] and oxygen isotopic composition differences [6-8] from primitive carbonaceous chondrites. Here, we report on our coordinated analyses of a suite of carbon-rich CS-IDPs focusing on their bulk compositions, mineralogy, mineral chemistry, and isotopic compositions.

  6. An analytical longitudinal dielectric function of primitive electrolyte solutions and its application in predicting thermodynamic properties

    International Nuclear Information System (INIS)

    Xiao, Tiejun

    2015-01-01

    In this paper, the longitudinal dielectric function ϵ_l(k) of primitive electrolyte solutions is discussed. Starting from a modified mean spherical approximation, an analytical dielectric function in terms of two parameters is established. These two parameters can be related to the first two decay parameters k_1_,_2 of the dielectric response modes of the bulk system, and can be determined using constraints of k_1_,_2 from statistical theories. Furthermore, a combination of this dielectric function and the molecular Debye-Hückel theory[J. Chem. Phys. 135(2011)104104] leads to a self-consistent mean filed description of electrolyte solutions. Our theory reveals a relationship between the microscopic structure parameters of electrolyte solutions and the macroscopic thermodynamic properties, which is applied to concentrated electrolyte solutions.

  7. Ion Irradiation Experiments on the Murchison CM2 Carbonaceous Chondrite: Simulating Space Weathering of Primitive Asteroids

    Science.gov (United States)

    Keller, L. P.; Christoffersen, R.; Dukes, C. A.; Baragiola, R. A.; Rahman, Z.

    2015-01-01

    Remote sensing observations show that space weathering processes affect all airless bodies in the Solar System to some degree. Sample analyses and lab experiments provide insights into the chemical, spectroscopic and mineralogic effects of space weathering and aid in the interpretation of remote- sensing data. For example, analyses of particles returned from the S-type asteroid Itokawa by the Hayabusa mission revealed that space-weathering on that body was dominated by interactions with the solar wind acting on LL ordinary chondrite-like materials [1, 2]. Understanding and predicting how the surface regoliths of primitive carbonaceous asteroids respond to space weathering processes is important for future sample return missions (Hayabusa 2 and OSIRIS-REx) that are targeting objects of this type. Here, we report the results of our preliminary ion irradiation experiments on a hydrated carbonaceous chondrite with emphasis on microstructural and infrared spectral changes.

  8. Performances of scintigraphy in the primitive hyperparathyroidism and the associated thyroid pathologies

    International Nuclear Information System (INIS)

    Monteil, J.; Mathonnet, M.; Chianea, T.; Cubertafond, P.; Piquet, L.; Rince, C.; Bournaud, E.; Verbeke, S.; Perdrisot, R.; Vandroux, J.C.

    1997-01-01

    The data from scintigraphic and echographic exploration were compared to the surgery results in 32 patients (29 F and 3 M) presenting a primitive hyperparathyroidism, biologically proved, associated to a thyroid pathology. The scintigraphies were achieved with a collimator placed anteriorly and oblique-anteriorly, 4 h after injection by iodine 123 (7 MBq) and 30 min and 2 h after injection of 99m Tc-MIBI (555 MBq). The cervical echography and scintigraphy are independently interpreted. The results are given in a table containing the sensitivity, specificity, V.P.P. and V.P.N. for scintigraphy and echography, respectively. The association of a primary hyperparathyroidism and of a thyroid pathology (with a prevalence of 70% in our region) appears to affect less the performances of scintigraphy imaging than those of morphologic imaging

  9. Construction of a magnetostrictive hysteresis operator using a tripod-like primitive hopfield neural network

    Science.gov (United States)

    Adly, A. A.; Abd-El-Hafiz, S. K.

    2018-05-01

    It is well known that accurate modeling of magnetostrictive hysteresis is crucial to different industrial applications. Although several magnetostrictive models have been developed in the past, the accuracy-efficiency balance has always been crucial. Recently, the possibility of constructing a primitive vector hysteresis operator using a tri-node Hopfield Neural Network (HNN) was demonstrated. Based upon the fact that mechanical stress along a certain direction results in dimensional deformation, this paper introduces a novel extension to the aforementioned recently developed approach. More specifically, a stress-driven evolution of a tri-node HNN hysteresis operator pair is proposed, thus yielding a tripod-like HNN pair having different input offset values. Model identification, sample simulation results and comparison with experimental measurements are given in the paper.

  10. Postoperative Paraplegia as a Result of Undiagnosed Primitive Neuroectodermal Tumor, Not Epidural Analgesia

    Directory of Open Access Journals (Sweden)

    Pei-Ching Hung

    2007-10-01

    Full Text Available Postoperative paraplegia is a rare complication after epidural analgesia and often occurs with spinal hematoma or cord injury. We present the case of a 16-year-old girl who suffered from a tumor mass in the neck and abdomen who underwent gynecologic operation. Preoperatively, liver metastasis was found by computed tomography. Pathologic findings revealed that the abdominal mass was an ovarian dermoid cyst. After the operation, the patient complained of paraplegia while receiving epidural analgesia for postoperative pain control. A peripheral primitive neuroectodermal tumor in the thoracic and lumbar spines with spinal cord compression was later detected using magnetic resonance imaging. Learning from this case, we suggest that when a patient is preoperatively diagnosed with tumor metastasis, back pain and soreness, spinal cord compression from tumor metastasis should be excluded before epidural analgesia is implemented.

  11. Congenital peripheral primitive neuroectodermal tumor: A case treated successfully with multimodality treatment

    International Nuclear Information System (INIS)

    Goyal, Sh.; Biswas, A.; Mohanti, B.K.; Gupta, R.

    2014-01-01

    Neonatal tumors comprise less than two percent of childhood malignancies. Most are solid tumors, most common histologies being teratoma and neuroblastoma. We encountered a child who was detected to have a right arm mass on antenatal sonogram, which was diagnosed to be a primitive neuroectodermal tumor involving the triceps on fine needle aspiration cytology performed in the post-natal period. The child was successfully treated with multimodality treatment consisting of surgery, chemotherapy and radiotherapy. We also discuss briefly the problems associated with therapy in neonatal period. A review of all cases reported to have congenital Ewing’s sarcoma family of tumors is presented. Novel therapies are needed to improve efficacy and decrease the devastating side effects of treatment in this age group.

  12. Primitive reflexes and cognitive function Reflexos primitivos e função cognitiva

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    Alfredo Damasceno

    2005-09-01

    Full Text Available BACKGROUND: Data on the prevalence of primitive reflexes (PR in adulthood, their pathological significance and relationship to age and cognition are controversial. OBJECTIVE: To study the relationship between PR and cognition in 30 patients with probable Alzheimer's disease (AD and 154 control subjects. METHOD: Diagnosis of probable AD was based on DSM-IV, NINCDS-ADRDA, and CAMDEX criteria. Primitive reflexes were quantified from zero (absent to 1 (mild or 2 (markedly present. The Cognitive Abilities Screening Instrument - Short Form (CASI-S was used to evaluate registration, temporal orientation, verbal fluency and recall. A drawing test was added. RESULTS: Most frequent PR among demented and controls were suck (77% and 62%, respectively and snout (60% and 27%, followed by glabellar (30% and 19%, paratonia (37% and 5%, and palmomental (23% and 5%. None of controls had more than three PR. Frequency of PR tended to increase with age and cognitive deterioration. Grasp and Babinski responses were found only in dementia patients. Primitive reflexes were not correlated with each other, except snout with suck, and snout with glabellar reflex. CONCLUSION: The finding of grasp and Babinski sign, or the presence of more than three primitive signs, particularly the combination of paratonia, snout, suck, and palmomental reflexes strongly suggests brain dysfunction, especially when these signs are marked and accompanied by deficits in orientation, recall, verbal fluency, and constructional praxis.CONTEXTO: A prevalência e significado patológico dos reflexos primitivos (RP no adulto, bem como sua relação com a idade e a cognição, são questões controversas. OBJETIVO: Estudar a relação entre RP e cognição em 30 pacientes com doença de Alzheimer (DA e 154 sujeitos controles normais. MÉTODO: O diagnóstico de DA baseou-se nos critérios DSM-IV, NINCDS-ADRDA e CAMDEX. Os RP foram quantificados de 0 (ausente a 1 (leve ou 2 (acentuado. CASI

  13. Primitive neuroectodermal tumor arising 8 years after chemotherapy and radiotherapy for acute lymphoblastic leukemia. Case report

    International Nuclear Information System (INIS)

    Yoshida, Yuya; Toma, Yasuo; Arai, Masayuki; Higashi, Ryo; Kashihara, Kengo; Kaizaki, Yasuharu

    2005-01-01

    We report a case of primitive neuroectodermal tumor (PNET) arising 8 years after chemotherapy and radiotherapy for acute lymphoblastic leukemia. A 15-year-old boy with a history of acute lymphoblastic leukemia, at the age of 7, underwent chemotherapy and 14 Gy of radiotherapy to the whole brain. He was admitted to our department due to the development of aphasia, right hemiparesis and generalized convulsive seizure. MRI showed an irregularly enhanced mass in the left frontal lobe. A gross total removal of the tumor was performed and histological examination showed it to be PNET. Postoperatively, the patient underwent 20 Gy of radiotherapy to the whole brain and 42 Gy of local radiotherapy. Follow-up MRI showed no evidence of recurrent tumor 4 months after the radiotherapy. This tumor was thought to be a secondary brain tumor arising in this survivor of childhood acute lymphoblastic leukemia and it is a rare complication of successful leukemia treatment. (author)

  14. Not so primitive: context-sensitive meta-learning about unattended sound sequences.

    Science.gov (United States)

    Todd, Juanita; Provost, Alexander; Whitson, Lisa R; Cooper, Gavin; Heathcote, Andrew

    2013-01-01

    Mismatch negativity (MMN), an evoked response potential elicited when a "deviant" sound violates a regularity in the auditory environment, is integral to auditory scene processing and has been used to demonstrate "primitive intelligence" in auditory short-term memory. Using a new multiple-context and -timescale protocol we show that MMN magnitude displays a context-sensitive modulation depending on changes in the probability of a deviant at multiple temporal scales. We demonstrate a primacy bias causing asymmetric evidence-based modulation of predictions about the environment, and we demonstrate that learning how to learn about deviant probability (meta-learning) induces context-sensitive variation in the accessibility of predictive long-term memory representations that underpin the MMN. The existence of the bias and meta-learning are consistent with automatic attributions of behavioral salience governing relevance-filtering processes operating outside of awareness.

  15. Solitary epidural brain metastasis of Neuroepithelioma (a Primitive Neuroectodermal Tumor: case report

    Directory of Open Access Journals (Sweden)

    Farnaz Farshidfar

    2008-08-01

    Full Text Available A 14 years old male was referred to Computerized tomography scan (CT of our hospital for evaluation of headache. The patient was known case of cervical soft tissue Primitive neuroectodermal tumor (PNET which has undergone surgery and radiotherapy 4 years ago. The CT scan showed large solitary extra axial, epidural lesion in right parietal region, with mass effect and bony involvement. Then surgery was done for him and the resultant biopsy was Neuroepithelioma. After diagnosis the patient has undergone chemotherapy and radiotherapy. He has no signs or symptoms of malignancy, and also follow up CT scan of the brain, chest, and abdomen were normal after two years of surgery. This is the first reported case of epidural metastasis of a head and neck PNET in an adolescent.

  16. Primitive Neuroectodermal Tumour in Young Adults - A Report of two Rare Cases and Review of Literature

    Directory of Open Access Journals (Sweden)

    Vidhya Lakshmi S

    2017-10-01

    Full Text Available Primitive Neuro Ectodermal Tumours’ (PNET are highly aggressive embryonal tumours of presumed neural crest origin. They are derived from neoplastic transformation of common progenitor cells in the sub ependymal matrix layer. They are more common in children. They are small round cell tumours affecting the central nervous system (CNS, others being Ewing’s sarcoma, medullobalstoma, lymphomas etc. They are classified based on their immune histochemical characteristics- neuronal, astrocytic, ependymal, retinal photo receptor, undifferentiated. Undifferentiated variety carries better prognosis. GFAP expression is an important prognostic factor. Presence of p53 germ line mutation indicates an increased risk for developing PNET. Spinal PNET are secondary to CSF metastasis from cranium commonly. Primary spinal PNET tumours are rare and extradural location is extremely rare. PNET needs multimodality approach but carries poor prognosis when compared to other CNS tumours.

  17. Ewing Sarcoma/Primitive Neuroectodermal Tumor of the Kidney: Two Unusual Presentations of a Rare Tumor

    Directory of Open Access Journals (Sweden)

    E. C. Castro

    2012-01-01

    Full Text Available Only few cases of primary renal Ewing's sarcoma have been reported in the literature to date. We present here two cases of renal ES/PNET with an uncanny presentation. The first case was discovered after the patient presented clinically with irradiating flank pain, mimicking the pain related with kidney stones. The second case had clinical presentation of pulmonary thromboembolism after the patient was involved in an automobilist accident. The tumors were mainly composed of small blue cells which by immunohistochemical were positive for neural markers, and FISH revealed the translocation 22q12 for the EWSR1 gene. The diagnosis of renal primitive neuroectodermal tumor/EWING tumor is very rare and usually involves several different diagnostic techniques. The differential diagnosis is usually broad with frequent overlapping features between the entities. The cases presented in this paper illustrated the difficulties with which routine anatomical pathologist is faced when dealing with rare renal poorly differentiated neoplasm in adults.

  18. Extraosseous Ewing's sarcoma / primitive neuroectodermal tumor of the sacral nerve plexus

    International Nuclear Information System (INIS)

    Narula, MK; Gupta, Nishant; Anand, Rama; Kapoor, Sudhir

    2009-01-01

    We report an unusual case of Ewing's sarcoma / primitive neuroectodermal tumor (PNET) of the sacral nerve plexus in a 9-year-old boy who presented with a soft tissue swelling and severe piercing pain in the lower back region. MRI of the lumbosacral spine showed a lobulated soft tissue mass with clubbed finger-like projections along the path of the sacral nerves, which had caused widening of the spinal canal and the sacral foramina (S2–S4 level). There was presacral extension and posterior scalloping of the sacral vertebrae. Histopathology of the lesion confirmed Ewing's sarcoma / PNET of the sacral spinal nerve plexus. The patient responded favorably to chemotherapy and radiotherapy, showing clinical and radiological improvement

  19. Regulated proliferation of primitive hematopoietic progenitor cells in long-term human marrow cultures

    International Nuclear Information System (INIS)

    Cashman, J.; Eaves, A.C.; Eaves, C.J.

    1985-01-01

    We have examined the cycling status of various classes of erythroid and granulopoietic progenitor populations maintained for many weeks in standard normal long-term human marrow cultures. These were initiated with a single inoculum of marrow aspirate and were routinely fed by weekly removal of half of the nonadherent cells and replacement of half of the growth medium. Progenitors of large erythroid colonies (more than eight erythroblast clusters) present in the nonadherent fraction and progenitors of small granulocyte/macrophage colonies (fewer than 500 cells) present in both the nonadherent and adherent fractions were found to be actively cycling at all times examined (28% to 63% kill following a 20-minute exposure to 20 microCi/mL of high specific activity 3 H-thymidine). In contrast, progenitors of large granulocyte/macrophage colonies (more than 500 cells) and progenitors of large erythroid colonies (more than eight erythroblast clusters), present in the adherent layer, consistently alternated between a quiescent state at the time of each weekly medium change and a proliferating state two to three days later (0% to 13% kill and 21% to 49% kill, respectively). Additional experiments revealed that the activation of primitive progenitors in the adherent layer was not dependent on the addition of fresh glutamine or hydrocortisone, nor on the physical manipulations involved in changing the growth medium. These studies provide the first direct evidence that normal long-term human marrow cultures support the continued turnover of a variety of early hematopoietic progenitor cell types. Further, they indicate that the proliferative activity of the most primitive of these progenitors is regulated by stage-specific cell-cell interactions that are subject to manipulation

  20. Analysis of immunoglobulin transcripts in the ostrich Struthio camelus, a primitive avian species.

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    Tian Huang

    Full Text Available Previous studies on the immunoglobulin (Ig genes in avian species are limited (mainly to galliformes and anseriformes but have revealed several interesting features, including the absence of the IgD and Igκ encoding genes, inversion of the IgA encoding gene and the use of gene conversion as the primary mechanism to generate an antibody repertoire. To better understand the Ig genes and their evolutionary development in birds, we analyzed the Ig genes in the ostrich (Struthio camelus, which is one of the most primitive birds. Similar to the chicken and duck, the ostrich expressed only three IgH chain isotypes (IgM, IgA and IgY and λ light chains. The IgM and IgY constant domains are similar to their counterparts described in other vertebrates. Although conventional IgM, IgA and IgY cDNAs were identified in the ostrich, we also detected a transcript encoding a short membrane-bound form of IgA (lacking the last two C(H exons that was undetectable at the protein level. No IgD or κ encoding genes were identified. The presence of a single leader peptide in the expressed heavy chain and light chain V regions indicates that gene conversion also plays a major role in the generation of antibody diversity in the ostrich. Because the ostrich is one of the most primitive living aves, this study suggests that the distinct features of the bird Ig genes appeared very early during the divergence of the avian species and are thus shared by most, if not all, avian species.

  1. The ECM moves during primitive streak formation--computation of ECM versus cellular motion.

    Directory of Open Access Journals (Sweden)

    Evan A Zamir

    2008-10-01

    Full Text Available Galileo described the concept of motion relativity--motion with respect to a reference frame--in 1632. He noted that a person below deck would be unable to discern whether the boat was moving. Embryologists, while recognizing that embryonic tissues undergo large-scale deformations, have failed to account for relative motion when analyzing cell motility data. A century of scientific articles has advanced the concept that embryonic cells move ("migrate" in an autonomous fashion such that, as time progresses, the cells and their progeny assemble an embryo. In sharp contrast, the motion of the surrounding extracellular matrix scaffold has been largely ignored/overlooked. We developed computational/optical methods that measure the extent embryonic cells move relative to the extracellular matrix. Our time-lapse data show that epiblastic cells largely move in concert with a sub-epiblastic extracellular matrix during stages 2 and 3 in primitive streak quail embryos. In other words, there is little cellular motion relative to the extracellular matrix scaffold--both components move together as a tissue. The extracellular matrix displacements exhibit bilateral vortical motion, convergence to the midline, and extension along the presumptive vertebral axis--all patterns previously attributed solely to cellular "migration." Our time-resolved data pose new challenges for understanding how extracellular chemical (morphogen gradients, widely hypothesized to guide cellular trajectories at early gastrulation stages, are maintained in this dynamic extracellular environment. We conclude that models describing primitive streak cellular guidance mechanisms must be able to account for sub-epiblastic extracellular matrix displacements.

  2. Octopus arm movements under constrained conditions: adaptation, modification and plasticity of motor primitives.

    Science.gov (United States)

    Richter, Jonas N; Hochner, Binyamin; Kuba, Michael J

    2015-04-01

    The motor control of the eight highly flexible arms of the common octopus (Octopus vulgaris) has been the focus of several recent studies. Our study is the first to manage to introduce a physical constraint to an octopus arm and investigate the adaptability of stereotypical bend propagation in reaching movements and the pseudo-limb articulation during fetching. Subjects (N=6) were placed inside a transparent Perspex box with a hole at the center that allowed the insertion of a single arm. Animals had to reach out through the hole toward a target, to retrieve a food reward and fetch it. All subjects successfully adjusted their movements to the constraint without an adaptation phase. During reaching tasks, the animals showed two movement strategies: stereotypical bend propagation reachings, which were established at the hole of the Perspex box and variant waving-like movements that showed no bend propagations. During fetching movements, no complete pseudo-joint fetching was observed outside the box and subjects pulled their arms through the hole in a pull-in like movement. Our findings show that there is some flexibility in the octopus motor system to adapt to a novel situation. However, at present, it seems that these changes are more an effect of random choices between different alternative motor programs, without showing clear learning effects in the choice between the alternatives. Interestingly, animals were able to adapt the fetching movements to the physical constraint, or as an alternative explanation, they could switch the motor primitive fetching to a different motor primitive 'arm pulling'. © 2015. Published by The Company of Biologists Ltd.

  3. Clinical analysis of primary primitive neuroectodermal tumors in the female genital tract.

    Science.gov (United States)

    Xiao, Changji; Zhao, Jing; Guo, Peng; Wang, Dan; Zhao, Dachun; Ren, Tong; Yang, Jiaxin; Shen, Keng; Lang, Jinghe; Xiang, Yang; Cui, Quancai

    2014-03-01

    The aim of the study was to investigate the clinical manifestations, diagnosis, treatment, and prognosis of primitive neuroectodermal tumors (PNETs) in the female genital tract. From April 2001 to May 2013, the clinicopathologic characteristics, treatments, outcomes, and prognosis of 11 patients with PNET in the female genital tract were analyzed retrospectively at our hospital. The location of PNET in the 11 patients presented here included vulva (2 patients), cervix (2 patients), uterus and its ligament (5 patients), and the ovaries (2 patients). Ages ranged from 18 to 59 years (median, 31 years).The main clinical manifestations of PNET in the female genital tract are irregular vaginal bleeding (6 patients), pelvic mass, uterine enlargement, and rapidly increasing vulvar mass (8 patients), and vulvar pain and lower abdominal pain (5 patients). The CA125 levels of 8 patients were elevated before the operations and reduced to normal when the diseases were controlled, while the levels increased as the tumor was progressive. Results for the most commonly used immunohistochemistry studies revealed CD99 in 11 of the 11 tumors, synaptophysin in 6 of the 7 positive tumors, and neuron-specific enolase in 6 of the 6 tumors. Ten patients underwent surgical resection. Nine of them underwent preoperative or/and postoperative combination chemotherapy. The follow-up of 10 patients were available and ranged from 1 to 145 months (median, 30.5 months), 3 of whom experiencing recurrence. Primitive neuroectodermal tumor is very rare and can originate from any part of the female genital tract. The tumors had different manifestations but the same pathologic features. CA125 may be an important marker for prognosis and follow-up of PNET of the female internal genital tract.

  4. Prediction of Intention during Interaction with iCub with Probabilistic Movement Primitives

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    Oriane Dermy

    2017-10-01

    Full Text Available This article describes our open-source software for predicting the intention of a user physically interacting with the humanoid robot iCub. Our goal is to allow the robot to infer the intention of the human partner during collaboration, by predicting the future intended trajectory: this capability is critical to design anticipatory behaviors that are crucial in human–robot collaborative scenarios, such as in co-manipulation, cooperative assembly, or transportation. We propose an approach to endow the iCub with basic capabilities of intention recognition, based on Probabilistic Movement Primitives (ProMPs, a versatile method for representing, generalizing, and reproducing complex motor skills. The robot learns a set of motion primitives from several demonstrations, provided by the human via physical interaction. During training, we model the collaborative scenario using human demonstrations. During the reproduction of the collaborative task, we use the acquired knowledge to recognize the intention of the human partner. Using a few early observations of the state of the robot, we can not only infer the intention of the partner but also complete the movement, even if the user breaks the physical interaction with the robot. We evaluate our approach in simulation and on the real iCub. In simulation, the iCub is driven by the user using the Geomagic Touch haptic device. In the real robot experiment, we directly interact with the iCub by grabbing and manually guiding the robot’s arm. We realize two experiments on the real robot: one with simple reaching trajectories, and one inspired by collaborative object sorting. The software implementing our approach is open source and available on the GitHub platform. In addition, we provide tutorials and videos.

  5. Iron oxide bands in the visible and near-infrared reflectance spectra of primitive asteroids

    Science.gov (United States)

    Jarvis, Kandy S.; Vilas, Faith; Gaffey, Michael J.

    1993-01-01

    High resolution reflectance spectra of primitive asteroids (C, P, and D class and associated subclasses) have commonly revealed an absorption feature centered at 0.7 microns attributed to an Fe(2+)-Fe(3+) charge transfer transition in iron oxides and/or oxidized iron in phyllosilicates. A smaller feature identified at 0.43 microns has been attributed to an Fe(3+) spin-forbidden transition in iron oxides. In the spectra of the two main-belt primitive asteroids 368 Haidea (D) and 877 Walkure (F), weak absorption features which were centered near the location of 0.60-0.65 microns and 0.80-0.90 microns prompted a search for features at these wavelengths and an attempt to identify their origin(s). The CCD reflectance spectra obtained between 1982-1992 were reviewed for similar absorption features located near these wavelengths. The spectra of asteroids in which these absorption features have been identified are shown. These spectra are plotted in order of increasing heliocentric distance. No division of the asteroids by class has been attempted here (although the absence of these features in the anhydrous S-class asteroids, many of which have presumably undergone full heating and differentiation should be noted). For this study, each spectrum was treated as a continuum with discrete absorption features superimposed on it. For each object, a linear least squares fit to the data points defined a simple linear continuum. The linear continuum was then divided into each spectrum, thus removing the sloped continuum and permitting the intercomparison of residual spectral features.

  6. β-Catenin Regulates Primitive Streak Induction through Collaborative Interactions with SMAD2/SMAD3 and OCT4

    DEFF Research Database (Denmark)

    Funa, Nina Sofi Ayumi; Schachter, Karen; Lerdrup, Mads

    2015-01-01

    Canonical Wnt and Nodal signaling are both required for induction of the primitive streak (PS), which guides organization of the early embryo. The Wnt effector b-catenin is thought to function in these early lineage specification decisions via transcriptional activation of Nodal signaling. Here, we...... specification. This study provides mechanistic insight into how Wnt signaling controls early cell lineage decisions....

  7. Development of a reliable method for determining sex for a primitive rodent, the Point Arena mountain beaver (Aplodontia rufa nigra)

    Science.gov (United States)

    Kristine L. Pilgrim; William J. Zielinski; Fredrick V. Schlexer; Michael K. Schwartz

    2012-01-01

    The mountain beaver (Aplodontia rufa) is a primitive species of rodent, often considered a living fossil. The Point Arena mountain beaver (Aplodontia rufa nigra) is an endangered subspecies that occurs in a very restricted range in northern California. Efforts to recover this taxon have been limited by the lack of knowledge on their demography, particularly sex and age...

  8. A novel splice mutation in the TP53 gene associated with Leydig cell tumor and primitive neuroectodermal tumor

    DEFF Research Database (Denmark)

    Stecher, Chalotte Willemann; Grønbaek, Kirsten; Hasle, Henrik

    2008-01-01

    A 20-month-old boy presented with precocious puberty due to a Leydig cell tumor, and at the age of 6 years with a primitive neuroectodermal brain-tumor (PNET). A novel splice site mutation of the TP53-gene, likely to be associated with a nonfunctional protein, was found in the proband, his father...

  9. High resolution array-based comparative genomic hybridisation of medulloblastomas and supra-tentorial primitive neuroectodermal tumours

    Science.gov (United States)

    McCabe, Martin Gerard; Ichimura, Koichi; Liu, Lu; Plant, Karen; Bäcklund, L Magnus; Pearson, Danita M; Collins, Vincent Peter

    2010-01-01

    Medulloblastomas and supratentorial primitive neuroectodermal tumours are aggressive childhood tumours. We report our findings using array comparative genomic hybridisation (CGH) on a whole-genome BAC/PAC/cosmid array with a median clone separation of 0.97Mb to study 34 medulloblastomas and 7 supratentorial primitive neuroectodermal tumours. Array CGH allowed identification and mapping of numerous novel small regions of copy number change to genomic sequence, in addition to the large regions already known from previous studies. Novel amplifications were identified, some encompassing oncogenes, MYCL1, PDGFRA, KIT and MYB, not previously reported to show amplification in these tumours. In addition, one supratentorial primitive neuroectodermal tumour had lost both copies of the tumour suppressor genes CDKN2A & CDKN2B. Ten medulloblastomas had findings suggestive of isochromosome 17q. In contrast to previous reports using conventional CGH, array CGH identified three distinct breakpoints in these cases: Ch 17: 17940393-19251679 (17p11.2, n=6), Ch 17: 20111990-23308272 (17p11.2-17q11.2, n=4) and Ch 17: 38425359-39091575 (17q21.31, n=1). Significant differences were found in the patterns of copy number change between medulloblastomas and supratentorial primitive neuroectodermal tumours, providing further evidence that these tumours are genetically distinct despite their morphological and behavioural similarities. PMID:16783165

  10. Spectrum Analysis of Inertial and Subinertial Motions Based on Analyzed Winds and Wind-Driven Currents from a Primitive Equation General Ocean Circulation Model.

    Science.gov (United States)

    1982-12-01

    1Muter.Te Motions Based on Ana lyzed Winds and wind-driven December 1982 Currents from. a Primitive Squat ion General a.OW -love"*..* Oean Circulation...mew se"$ (comeS.... do oISN..u am ae~ 00do OWaor NUN Fourier and Rotary Spc , Analysis Modeled Inertial and Subinrtial Motion 4 Primitive Equation

  11. Radiotherapy in stereotactic conditions with CyberKnife of primitive or secondary hepatic lesions: lessons learnt by the Alexis-Vautrin Centre

    International Nuclear Information System (INIS)

    Taste-George, H.; Peiffert, D.

    2010-01-01

    The author report the experience gained on patients treated by irradiation in stereotactic conditions for primitive or secondary hepatic lesions. Thirty three patients have been treated, 22 suffering from secondary lesions and 11 from primitive lesions. The treatment technique is not much constraining for the patient, is not much toxic, and provides a high local tumour control. Short communication

  12. The negative impact of Wnt signaling on megakaryocyte and primitive erythroid progenitors derived from human embryonic stem cells

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    Prasuna Paluru

    2014-03-01

    Full Text Available The Wnt gene family consists of structurally related genes encoding secreted signaling molecules that have been implicated in many developmental processes, including regulation of cell fate and patterning during embryogenesis. Previously, we found that Wnt signaling is required for primitive or yolk sac-derived-erythropoiesis using the murine embryonic stem cell (ESC system. Here, we examine the effect of Wnt signaling on the formation of early hematopoietic progenitors derived from human ESCs. The first hematopoietic progenitor cells in the human ESC system express the pan-hematopoietic marker CD41 and the erythrocyte marker, glycophorin A or CD235. We have developed a novel serum-free, feeder-free, adherent differentiation system that can efficiently generate large numbers of CD41 + CD235+ cells. We demonstrate that this cell population contains progenitors not just for primitive erythroid and megakaryocyte cells but for the myeloid lineage as well and term this population the primitive common myeloid progenitor (CMP. Treatment of mesoderm-specified cells with Wnt3a led to a loss of hematopoietic colony-forming ability while the inhibition of canonical Wnt signaling with DKK1 led to an increase in the number of primitive CMPs. Canonical Wnt signaling also inhibits the expansion and/or survival of primitive erythrocytes and megakaryocytes, but not myeloid cells, derived from this progenitor population. These findings are in contrast to the role of Wnt signaling during mouse ESC differentiation and demonstrate the importance of the human ESC system in studying species-specific differences in development.

  13. The Impact of Using Student-Dictated Oral Review Stories on Science Vocabulary, Content Knowledge, and Non-Fiction Writing Skills of First Grade Students

    Science.gov (United States)

    Bishoff, Sandra Wells

    2010-01-01

    The purpose of this study was to determine if using an intervention called Student Dictated Oral Review Stories (SDORS) had an effect on science vocabulary usage and content knowledge for ninety-three students in six first grade classrooms and the subgroup of economically disadvantaged students in a mid-sized north Texas school district. The…

  14. Assessing the Performance of Automatic Speech Recognition Systems When Used by Native and Non-Native Speakers of Three Major Languages in Dictation Workflows

    DEFF Research Database (Denmark)

    Zapata, Julián; Kirkedal, Andreas Søeborg

    2015-01-01

    In this paper, we report on a two-part experiment aiming to assess and compare the performance of two types of automatic speech recognition (ASR) systems on two different computational platforms when used to augment dictation workflows. The experiment was performed with a sample of speakers...

  15. The effects of automatic spelling correction software on understanding and comprehension in compensated dyslexia: improved recall following dictation.

    Science.gov (United States)

    Hiscox, Lucy; Leonavičiūtė, Erika; Humby, Trevor

    2014-08-01

    Dyslexia is associated with difficulties in language-specific skills such as spelling, writing and reading; the difficulty in acquiring literacy skills is not a result of low intelligence or the absence of learning opportunity, but these issues will persist throughout life and could affect long-term education. Writing is a complex process involving many different functions, integrated by the working memory system; people with dyslexia have a working memory deficit, which means that concentration on writing quality may be detrimental to understanding. We confirm impaired working memory in a sample of university students with (compensated) dyslexia, and using a within-subject design with three test conditions, we show that these participants demonstrated better understanding of a piece of text if they had used automatic spelling correction software during a dictation/transcription task. We hypothesize that the use of the autocorrecting software reduced demand on working memory, by allowing word writing to be more automatic, thus enabling better processing and understanding of the content of the transcriptions and improved recall. Long-term and regular use of autocorrecting assistive software should be beneficial for people with and without dyslexia and may improve confidence, written work, academic achievement and self-esteem, which are all affected in dyslexia. Copyright © 2014 John Wiley & Sons, Ltd.

  16. Altered but Not Silenced: How Shostakovich Retained His Voice as an Artist despite the Demands of a Dictator

    Directory of Open Access Journals (Sweden)

    Hope R. Strayer

    2013-12-01

    Full Text Available Can music that is regulated and restrained by a dictator still be inspired? This question reveals ideology concerning how music should be created and valued. Does outside control restrict artistic integrity and autonomy? Not all composers have been free to write whatever their soul demands. People in authority have held power and control over artistic processes. Dmitri Shostakovich was a Russian composer whose work was subjected to the tastes of a tyrannical ruler and Communist party. Though Shostakovich did not compose in an environment that fostered musical exploration, his work should not be mourned but celebrated. Shostakovich was not a victim, but a victor of his music by the way he composed in the midst of the threat of denouncement. Though Shostakovich wrote music to follow the demands of others, the music was still his by the very fact that he created it; he brought it into existence and highlighted it with nuances of his being and personality as he produced each work. This research examines three critical pieces of Shostakovich’s canon to ascertain whether controlled art subjected to the whims, preferences, and objectives of others can still be inspired. Though a composer might be told what to say, it is he who chooses how to word a phrase. Shostakovich’s output, particularly the first symphony, his opera Lady Macbeth of the Mtsensk District, and fifth symphony exemplify that restrained and restricted music does not necessitate a sacrifice in artistic integrity; it can be inspired, celebrated, and worthy of study.

  17. Hierarchical Bayesian analysis of outcome- and process-based social preferences and beliefs in Dictator Games and sequential Prisoner's Dilemmas.

    Science.gov (United States)

    Aksoy, Ozan; Weesie, Jeroen

    2014-05-01

    In this paper, using a within-subjects design, we estimate the utility weights that subjects attach to the outcome of their interaction partners in four decision situations: (1) binary Dictator Games (DG), second player's role in the sequential Prisoner's Dilemma (PD) after the first player (2) cooperated and (3) defected, and (4) first player's role in the sequential Prisoner's Dilemma game. We find that the average weights in these four decision situations have the following order: (1)>(2)>(4)>(3). Moreover, the average weight is positive in (1) but negative in (2), (3), and (4). Our findings indicate the existence of strong negative and small positive reciprocity for the average subject, but there is also high interpersonal variation in the weights in these four nodes. We conclude that the PD frame makes subjects more competitive than the DG frame. Using hierarchical Bayesian modeling, we simultaneously analyze beliefs of subjects about others' utility weights in the same four decision situations. We compare several alternative theoretical models on beliefs, e.g., rational beliefs (Bayesian-Nash equilibrium) and a consensus model. Our results on beliefs strongly support the consensus effect and refute rational beliefs: there is a strong relationship between own preferences and beliefs and this relationship is relatively stable across the four decision situations. Copyright © 2014 Elsevier Inc. All rights reserved.

  18. The Oxytocin Receptor (OXTR) Contributes to Prosocial Fund Allocations in the Dictator Game and the Social Value Orientations Task

    Science.gov (United States)

    Israel, Salomon; Lerer, Elad; Shalev, Idan; Uzefovsky, Florina; Riebold, Mathias; Laiba, Efrat; Bachner-Melman, Rachel; Maril, Anat; Bornstein, Gary; Knafo, Ariel; Ebstein, Richard P.

    2009-01-01

    Background Economic games observe social decision making in the laboratory that involves real money payoffs. Previously we have shown that allocation of funds in the Dictator Game (DG), a paradigm that illustrates costly altruistic behavior, is partially determined by promoter-region repeat region variants in the arginine vasopressin 1a receptor gene (AVPR1a). In the current investigation, the gene encoding the related oxytocin receptor (OXTR) was tested for association with the DG and a related paradigm, the Social Values Orientation (SVO) task. Methodology/Principal Findings Association (101 male and 102 female students) using a robust-family based test between 15 single tagging SNPs (htSNPs) across the OXTR was demonstrated with both the DG and SVO. Three htSNPs across the gene region showed significant association with both of the two games. The most significant association was observed with rs1042778 (p = 0.001). Haplotype analysis also showed significant associations for both DG and SVO. Following permutation test adjustment, significance was observed for 2–5 locus haplotypes (pprosocial decision making converges with a large body of animal research showing that oxytocin is an important social hormone across vertebrates including Homo sapiens. Individual differences in prosocial behavior have been shown by twin studies to have a substantial genetic basis and the current investigation demonstrates that common variants in the oxytocin receptor gene, an important element of mammalian social circuitry, underlie such individual differences. PMID:19461999

  19. Development of a speech-based dialogue system for report dictation and machine control in the endoscopic laboratory.

    Science.gov (United States)

    Molnar, B; Gergely, J; Toth, G; Pronai, L; Zagoni, T; Papik, K; Tulassay, Z

    2000-01-01

    Reporting and machine control based on speech technology can enhance work efficiency in the gastrointestinal endoscopy laboratory. The status and activation of endoscopy laboratory equipment were described as a multivariate parameter and function system. Speech recognition, text evaluation and action definition engines were installed. Special programs were developed for the grammatical analysis of command sentences, and a rule-based expert system for the definition of machine answers. A speech backup engine provides feedback to the user. Techniques were applied based on the "Hidden Markov" model of discrete word, user-independent speech recognition and on phoneme-based speech synthesis. Speech samples were collected from three male low-tone investigators. The dictation module and machine control modules were incorporated in a personal computer (PC) simulation program. Altogether 100 unidentified patient records were analyzed. The sentences were grouped according to keywords, which indicate the main topics of a gastrointestinal endoscopy report. They were: "endoscope", "esophagus", "cardia", "fundus", "corpus", "antrum", "pylorus", "bulbus", and "postbulbar section", in addition to the major pathological findings: "erosion", "ulceration", and "malignancy". "Biopsy" and "diagnosis" were also included. We implemented wireless speech communication control commands for equipment including an endoscopy unit, video, monitor, printer, and PC. The recognition rate was 95%. Speech technology may soon become an integrated part of our daily routine in the endoscopy laboratory. A central speech and laboratory computer could be the most efficient alternative to having separate speech recognition units in all items of equipment.

  20. No Place to Hide: Missing Primitive Stars Outside Milky Way Uncovered

    Science.gov (United States)

    2010-02-01

    After years of successful concealment, the most primitive stars outside our Milky Way galaxy have finally been unmasked. New observations using ESO's Very Large Telescope have been used to solve an important astrophysical puzzle concerning the oldest stars in our galactic neighbourhood - which is crucial for our understanding of the earliest stars in the Universe. "We have, in effect, found a flaw in the forensic methods used until now," says Else Starkenburg, lead author of the paper reporting the study. "Our improved approach allows us to uncover the primitive stars hidden among all the other, more common stars." Primitive stars are thought to have formed from material forged shortly after the Big Bang, 13.7 billion years ago. They typically have less than one thousandth the amount of chemical elements heavier than hydrogen and helium found in the Sun and are called "extremely metal-poor stars" [1]. They belong to one of the first generations of stars in the nearby Universe. Such stars are extremely rare and mainly observed in the Milky Way. Cosmologists think that larger galaxies like the Milky Way formed from the merger of smaller galaxies. Our Milky Way's population of extremely metal-poor or "primitive" stars should already have been present in the dwarf galaxies from which it formed, and similar populations should be present in other dwarf galaxies. "So far, evidence for them has been scarce," says co-author Giuseppina Battaglia. "Large surveys conducted in the last few years kept showing that the most ancient populations of stars in the Milky Way and dwarf galaxies did not match, which was not at all expected from cosmological models." Element abundances are measured from spectra, which provide the chemical fingerprints of stars [2]. The Dwarf galaxies Abundances and Radial-velocities Team [3] used the FLAMES instrument on ESO's Very Large Telescope to measure the spectra of over 2000 individual giant stars in four of our galactic neighbours, the Fornax

  1. In situ characterization of organic matter in two primitive chondrites through correlated microanalytical techniques

    Science.gov (United States)

    Wende, A. M.; Nittler, L.; Steele, A.; Herd, C. D.

    2009-12-01

    Primitive meteorites contain up to 2 wt % C, much of it in the form of insoluble organic matter (IOM). Bulk analyses have revealed the IOM to be marked by large D and 15N enrichments relative to terrestrial values. Isotopic imaging studies have revealed the presence of `hotspots’, sub-μm to μm-sized regions of IOM exhibiting extreme isotope enrichments. An interesting subpopulation of organic grains, ’nanoglobules’, which have hollow, spherical morphologies, is known to account for a portion of these hot spots. Previous work has suggested that nanoglobules can be identified in situ by native UV fluorescence. The isotopic enrichments are believed to point to low-T chemical fractionations either in the interstellar medium (ISM) or the outer regions of the early Solar System. As part of a larger study investigating the origin and evolution of IOM in the Solar System, a correlated, in situ, microanalytical approach was employed to characterize local isotopic and morphological heterogeneities in IOM in the highly primitive chondrites QUE 99177 (CR3) and Tagish Lake (C-ung). Previous NanoSIMS ion imaging of a QUE 99177 section revealed the spatial and isotopic distribution of C in the matrix with a spatial resolution of 200 nm. Manual definition of >3300 C-rich regions in the NanoSIMS images indicates that grains smaller than 1 μm across, which account for 80% of the IOM area, have a size distribution that is similar to estimates of the size distribution of carbonaceous dust in the diffuse ISM, supporting an interstellar origin for the IOM. Micro-Raman spectroscopy, which is highly sensitive to the degree of disorder in carbonaceous materials, was attempted on the same regions analyzed by NanoSIMS in QUE 99177. Unfortunately, surface damage due to both the prior SIMS analyses and removal of a prior C coat precluded acquisition of useful Raman spectra. Consequently, future correlated work will entail performing Raman analyses on uncoated samples prior to SIMS

  2. Integrated bioinformatic analysis unveils significant genes and pathways in the pathogenesis of supratentorial primitive neuroectodermal tumor

    Directory of Open Access Journals (Sweden)

    Wang G

    2018-04-01

    Full Text Available Guang-Yu Wang,1,* Ling Li,2,* Bo Liu,1 Xiao Han,1 Chun-Hua Wang,1 Ji-Wen Wang3 1Department of Neurosurgery, 2Department of Pediatrics, Qilu Children’s Hospital of Shandong University, Jinan, Shandong, 3Department of Neurology, Shanghai Children’s Medical Center, Shanghai Jiaotong University School of Medicine, Pudong New District, Shanghai, People’s Republic of China *These authors contributed equally to this work Purpose: This study aimed to explore significant genes and pathways involved in the pathogenesis of supratentorial primitive neuroectodermal tumor (sPNET. Materials and methods: Gene expression profile of GSE14295 was downloaded from publicly available Gene Expression Omnibus (GEO database. Differentially expressed genes (DEGs were screened out in primary sPNET samples compared with normal fetal and adult brain reference samples (sPNET vs fetal brain and sPNET vs adult brain. Pathway enrichment analysis of these DEGs was conducted, followed by protein–protein interaction (PPI network construction and significant module selection. Additionally, transcription factors (TFs regulating the common DEGs in the two comparison groups were identified, and the regulatory network was constructed. Results: In total, 526 DEGs (99 up- and 427 downregulated in sPNET vs fetal brain and 815 DEGs (200 up- and 615 downregulated in sPNET vs adult brain were identified. DEGs in sPNET vs fetal brain and sPNET vs adult brain were associated with calcium signaling pathway, cell cycle, and p53 signaling pathway. CDK1, CDC20, BUB1B, and BUB1 were hub nodes in the PPI networks of DEGs in sPNET vs fetal brain and sPNET vs adult brain. Significant modules were extracted from the PPI networks. In addition, 64 upregulated and 200 downregulated overlapping DEGs were identified in both sPNET vs fetal brain and sPNET vs adult brain. The genes involved in the regulatory network upon overlapping DEGs and the TFs were correlated with calcium signaling pathway

  3. Interspecific comparison of the effects of continuous ionizing radiation on the primitive mammalian stem germ cell

    International Nuclear Information System (INIS)

    Erickson, B.H.

    1978-01-01

    The response of the mammalian oocyte to radiation is characterized by wide interspecific differences, and results of preliminary assays suggest that this may be the case with the primitive stem germ cell. To test the validity of this observation and to define probable causes for the differences, prenatal mice, rats, and guinea pigs were irradiated continuously throughout gestation at rates of 1 and 3 rads per 23-hr day. Prenatal pigs were irradiated continuously for 108 days at a dose rate of 0.25 rad per 23-hr day. In all cases germ cells were enumerated in gonads excised either at birth or 6 days after birth. A dose rate of 0.25 rad/day reduced the germ-cell number in the male and female pig to 38 and 60% of control, respectively, and only 1 and 5% of the germ cells in the respective sexes survived a dose rate of 1 rad/day. Application of the single-hit multitarget model to all pig data yielded values for D 0 and n of 28 and 0.8, respectively, for the male and 27 and 3.2, respectively, for the female. Corresponding values for the male and female rat were 275 (D 0 ) and 0.3 (n) and 159 (D 0 ) and 0.8 (n), respectively. Both sexes of the pig were either sterilized or brought near sterility by a dose rate of 1 rad/day. In the case of the male rodent, however, this dose rate reduced germ-cell number to only 71% of control in the mouse, 50% of control in the rat, and 41% of control in the guinea pig. Ninety percent of the germ cells in the female rat survived a dose rate of 1 rad/day, as did 87% in the mouse and 71% in the guinea pig. When total dose was used as the basis of comparison, the pig remained the most sensitive species. Thus the differences among rodent species are not great when compared to the tremendous difference between the rodent and pig. When rodents are compared with pigs, the difference in the magnitude of the effect of continuous irradiation on the primitive stem cells of both sexes appears to be dependent on length of time at risk

  4. The solar nebula redox state as recorded by most reduced chondrules of five primitive chondrites

    International Nuclear Information System (INIS)

    Johnson, M.C.; Harvard Univ., Cambridge, MA

    1986-01-01

    Mafic minerals in the most reduced chondrules of five primitive meteorites were analyzed with an electron microprobe to determine the lower limit on their FeO contents. The accuracy obtained was +-0.01 weight percent FeO. The thermodynamic relationship between mole fraction FeSiO 3 and pO 2 of the ambient nebular gas at the time of mineral equilibration was established, and was used to infer the local O/H ratio of the nebular gas during chondrule formation. The lowest ferrosilite compositions reflected equilibration at 1500K with a gas 2-18 times more oxidizing than a gas of solar composition. Olivines in low-FeO UOC chondrules are uniformly more FeO-rich than coexisting pyroxenes. This descrepancy suggests that a significant change in the O/H ratio of the nebular gas occurred between the time of olivine and pyroxene crystallization in the region of the nebula where UOCs formed. Mineral compositions in the chondrules of two C2 chondrites studied suggest they formed in a more homogeneous region of the nebula than the UOCs. (author)

  5. Condensation time of the solar nebula from extinct I-129 in primitive meteorites

    Science.gov (United States)

    Lewis, R. S.; Anders, E.

    1975-01-01

    Mineral separates from five carbonaceous chondrites were dated by extinct 16 million year I-129, in an attempt to establish the condensation time of the solar nebula. Two Fe3O4 or Fe3O4-FeS samples from the Murchison and Orgueil meteorites are older than any other material dated thus far, and apparently formed within 200,000 years of each other. The great age, close isochronism, and primitive nature of the samples suggest that the event recorded was the condensation stage of the solar nebula. It provides a suitable zero point for the chronology of the early solar system. The I-129/I-127 ratio during condensation of the nebula was (1.46 plus or minus 0.04) times 0.0001. The recrystallized C4 chondrite Karoonda began to retain Xe-129 1.8 plus or minus 0.5 million years after the above event. This short cooling time implies rapid accretion (not exceeding 1 million years) and a shallow origin (not exceeding 10 km) below the surface of its parent body.-

  6. Accurate identification of RNA editing sites from primitive sequence with deep neural networks.

    Science.gov (United States)

    Ouyang, Zhangyi; Liu, Feng; Zhao, Chenghui; Ren, Chao; An, Gaole; Mei, Chuan; Bo, Xiaochen; Shu, Wenjie

    2018-04-16

    RNA editing is a post-transcriptional RNA sequence alteration. Current methods have identified editing sites and facilitated research but require sufficient genomic annotations and prior-knowledge-based filtering steps, resulting in a cumbersome, time-consuming identification process. Moreover, these methods have limited generalizability and applicability in species with insufficient genomic annotations or in conditions of limited prior knowledge. We developed DeepRed, a deep learning-based method that identifies RNA editing from primitive RNA sequences without prior-knowledge-based filtering steps or genomic annotations. DeepRed achieved 98.1% and 97.9% area under the curve (AUC) in training and test sets, respectively. We further validated DeepRed using experimentally verified U87 cell RNA-seq data, achieving 97.9% positive predictive value (PPV). We demonstrated that DeepRed offers better prediction accuracy and computational efficiency than current methods with large-scale, mass RNA-seq data. We used DeepRed to assess the impact of multiple factors on editing identification with RNA-seq data from the Association of Biomolecular Resource Facilities and Sequencing Quality Control projects. We explored developmental RNA editing pattern changes during human early embryogenesis and evolutionary patterns in Drosophila species and the primate lineage using DeepRed. Our work illustrates DeepRed's state-of-the-art performance; it may decipher the hidden principles behind RNA editing, making editing detection convenient and effective.

  7. Condensation time of the solar nebula from extinct 129I in primitive meteorites

    International Nuclear Information System (INIS)

    Lewis, R.S.; Anders, E.

    1975-01-01

    Mineral separates from five carbonaceous chondrites were dated by extinct 16 million year 129 I, in an attempt to establish the condensation time of the solar nebula. Two Fe 3 O 4 or Fe 3 O 4 --FeS samples from the Murchison and Orgueil meteorites are older than any other material dated thus far, and apparently formed within 2 x 10 5 years of each other. The great age, close isochronism, and primitive nature of the samples suggest that the event recorded was the condensation stage of the solar nebula. It provides a suitable zero point for the chronology of the early solar system. The 129 I/ 127 I ratio during condensation of the nebula was (1.46 +- 0.04) x 10 -4 . The recrystallized C4 chondrite Karoonda began to retain 129 Xe 1.8 +- 0.5 million years after the above event. This short cooling time implies rapid accretion (less than or equal to 1 million years) and a shallow origin (less than or equal to 10 km) below the surface of its parent body. (U.S.)

  8. Primitive robotic procedures: Automotions for medical liquids in 12th century Asia minor

    Directory of Open Access Journals (Sweden)

    Necmettin Penbegul

    2014-12-01

    Full Text Available In recent years, day by day, robotic surgery applications have increase their role in our medical life. In this article, we reported the discovery of the first primitive robotic applications as automatic machines for the sensitive calculation of liquids such as blood in the literature. Al-Jazari who wrote the book “Elcâmi ‘Beyne’l - ‘ilm ve’l - ‘amel en-nâfi ‘fi es-sınaâ ‘ti’l - hiyel”, lived in Anatolian territory between 1136 and 1206. In this book that was written in the twelfth century, Al-Jazari described nearly fifty graphics of robotic machines and six of them that were designed for medical purposes. We found that some of the robots mentioned in this book are related to medical applications. This book reviews approximately 50 devices, including water clocks, candle clocks, ewers, various automata used for amusement in drink assemblies, automata used for ablution, blood collection tanks, fountains, music devices, devices for water lifting, locks, a protractor, a boat-shaped water clock, and the gate of Diyarbakir City in south-east of Turkey, actually in northern Mesopotamia. We found that automata used for ablution and blood collection tanks were related with medical applications; therefore, we will describe these robots.

  9. Generalized large-scale semigeostrophic approximations for the f-plane primitive equations

    Science.gov (United States)

    Oliver, Marcel; Vasylkevych, Sergiy

    2016-05-01

    We derive a family of balance models for rotating stratified flow in the primitive equation (PE) setting. By construction, the models possess conservation laws for energy and potential vorticity and are formally of the same order of accuracy as Hoskins’ semigeostrophic equations. Our construction is based on choosing a new coordinate frame for the PE variational principle in such a way that the consistently truncated Lagrangian degenerates. We show that the balance relations so obtained are elliptic when the fluid is stably stratified and certain smallness assumptions are satisfied. Moreover, the potential temperature can be recovered from the potential vorticity via inversion of a non-standard Monge-Ampère problem which is subject to the same ellipticity condition. While the present work is entirely formal, we conjecture, based on a careful rewriting of the equations of motion and a straightforward derivative count, that the Cauchy problem for the balance models is well posed subject to conditions on the initial data. Our family of models includes, in particular, the stratified analog of the L 1 balance model of Salmon.

  10. Comparison of regeneration potentials in tissue cultures of primitive and cultivated tomato species (Lycopersicon sp.

    Directory of Open Access Journals (Sweden)

    M. Lech

    2014-01-01

    Full Text Available Regeneration capacities of two tomato cultivars: Potentat and Rutgers, and of three accessions of wild tomato species: Lycopersicon peruvianum PI 128650, L. peruvianum var. dentatum PI 128655 and L. glandulosum were studied using an universal medium suitable for regeneration of those plants from leaf pieces in tissue culture. Fragments of leaf blades were taken from plants raised in greenhouse conditions and placed on a modified MS medium containing 0.3 mg/l IAA and 3.0 mg/l BAP solidified with 1% agar. The explants were transferred every 4-5 weeks on fresh medium of the same composition. It was shown that all the three primitive tomato species revealed much higher multiplication coefficients than the two cultivars. Appropriate values were: 11 - for L. glandulosum, 8 - for L. peruvianum, 7 - for L. peruvianum var. dentatum, 4 - for L. esculentum cv. Potentat and 2 - cv. Rutgers. Completely regenerated plants were obtained from all the tested species, but organogenesis occurred almost two weeks earlier in wild tomatoes than in the culitivated varieties of L. esculentum.

  11. Origins of brain asymmetry: lateralization of odour memory recall in primitive Australian stingless bees.

    Science.gov (United States)

    Frasnelli, Elisa; Vallortigara, Giorgio; Rogers, Lesley J

    2011-10-10

    Left-right antennal asymmetry has been reported in honeybees. We studied primitive social bees to investigate the evolutionary origins of the asymmetry. Three species of Australian native, stingless bees (Trigona carbonaria, Trigona hockingsi and Austroplebeia australis) were trained to discriminate two odours, lemon (+)/vanilla (-), using the Proboscis Extension Reflex (PER). Recall of the olfactory memory at 1h after training was better when the odour was presented on the right than on the left side of the bee. In contrast, recall at 5h after training was better when the odour was presented on the left than on the right side of the bee. An additional experiment with T. hockingsi bees, fed with sugar 1h before recall and tested at 5h, produced similar results, showing that the shift in lateralized recall was due to the lapse of time per se and not to changes in motivation to feed. Stingless bees show the same laterality as honeybees, suggesting that asymmetry evolved prior to the evolutionary divergence of these species. Copyright © 2011 Elsevier B.V. All rights reserved.

  12. Treatment Outcome and Prognostic Molecular Markers of Supratentorial Primitive Neuroectodermal Tumors.

    Directory of Open Access Journals (Sweden)

    Seo Hee Choi

    Full Text Available To identify prognostic factors and define the optimal management of patients with supratentorial primitive neuroectodermal tumors (sPNETs, we investigated treatment outcomes and explored the prognostic value of specific molecular markers.A total of 47 consecutive patients with pathologically confirmed sPNETs between May 1985 and June 2012 were included. Immunohistochemical analysis of LIN28, OLIG2, and Rad51 expression was performed and correlated with clinical outcome.With a median follow-up of 70 months, 5-year overall survival (OS and progression-free survival (PFS was 55.5% and 40%, respectively, for all patients. Age, surgical extent, and radiotherapy were significant prognostic factors for OS and PFS. Patients who received initially planned multimodal treatment without interruption (i.e., radiotherapy and surgery (≥subtotal resection, with or without chemotherapy showed significantly higher 5-year OS (71.2% and PFS (63.1%. In 29 patients with available tumor specimens, tumors with high expression of either LIN28 or OLIG2 or elevated level of Rad51 were significantly associated with poorer prognosis.We found that multimodal treatment improved outcomes for sPNET patients, especially when radiotherapy and ≥subtotal resection were part of the treatment regimen. Furthermore, we confirmed the prognostic significance of LIN28 and OLIG2 and revealed the potential role of Rad51 in sPNETs.

  13. Characterization of insoluble organic matter in primitive meteorites by microRaman spectroscopy

    Science.gov (United States)

    Busemann, Henner; Alexander, M. O'd.; Nittler, Larry R.

    2007-08-01

    We have analyzed the chemically and isotopically well-characterized insoluble organic matter (IOM) extracted from 51 unequilibrated chondrites (8 CR, 9 CM, 1 CI, 3 ungrouped C, 9 CO, 9 CV, 10 ordinary, 1 CB and 1 E chondrites) using confocal imaging Raman spectroscopy. The average Raman properties of the IOM, as parameterized by the peak characteristics of the so-called D and G bands, which originate from aromatic C rings, show systematic trends that are correlated with meteorite (sub-) classification and IOM chemical compositions. Processes that affect the Raman and chemical properties of the IOM, such as thermal metamorphism experienced on the parent bodies, terrestrial weathering and amorphization due to irradiation in space, have been identified. We established separate sequences of metamorphism for ordinary, CO, oxidized, and reduced CV chondrites. Several spectra from the most primitive chondrites reveal the presence of organic matter that has been amorphized. This amorphization, usually the result of sputtering processes or UV or particle irradiation, could have occurred during the formation of the organic material in interstellar or protoplanetary ices or, less likely, on the surface of the parent bodies or during the transport of the meteorites to Earth. D band widths and peak metamorphic temperatures are strongly correlated, allowing for a straightforward estimation of these temperatures.

  14. A primitive endogenous lentivirus in a colugo: insights into the early evolution of lentiviruses.

    Science.gov (United States)

    Han, Guan-Zhu; Worobey, Michael

    2015-01-01

    Lentiviruses infect a wide range of mammal species. Much remains unknown about their deep history and host distribution. Here, we report the discovery of an endogenous lentivirus within the genome of the Sunda flying lemur (Galeopterus variegatus) (which we designate "Galeopterus variegatus endogenous lentivirus" [GvaELV]). We estimate the GvaELV genome invasion to have occurred more than 14 Ma, supporting an ancient origin of the lentivirus clade and an ancient lentiviral infection in colugo. Phylogenetic analyses show that GvaELV is a sister group of all previously known lentiviruses. The GvaELV genome appears to possess some primitive genomic features of a lentivirus, encoding not only a trans-activator of transcription (tat) gene but also two additional putative accessory genes that share no discernible similarity with other lentiviral accessory genes. The discovery of GvaELV provides novel insights into the prehistory and host distribution of lentivirus. © The Author 2014. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  15. Normalization of Complete Genome Characteristics: Application to Evolution from Primitive Organisms to Homo sapiens.

    Science.gov (United States)

    Sorimachi, Kenji; Okayasu, Teiji; Ohhira, Shuji

    2015-04-01

    Normalized nucleotide and amino acid contents of complete genome sequences can be visualized as radar charts. The shapes of these charts depict the characteristics of an organism's genome. The normalized values calculated from the genome sequence theoretically exclude experimental errors. Further, because normalization is independent of both target size and kind, this procedure is applicable not only to single genes but also to whole genomes, which consist of a huge number of different genes. In this review, we discuss the applications of the normalization of the nucleotide and predicted amino acid contents of complete genomes to the investigation of genome structure and to evolutionary research from primitive organisms to Homo sapiens. Some of the results could never have been obtained from the analysis of individual nucleotide or amino acid sequences but were revealed only after the normalization of nucleotide and amino acid contents was applied to genome research. The discovery that genome structure was homogeneous was obtained only after normalization methods were applied to the nucleotide or predicted amino acid contents of genome sequences. Normalization procedures are also applicable to evolutionary research. Thus, normalization of the contents of whole genomes is a useful procedure that can help to characterize organisms.

  16. Primary Ewing's sarcoma-primitive neuroectodermal tumor of the uterus: a case report and literature review.

    Science.gov (United States)

    Park, Jeong-Yeol; Lee, Sun; Kang, Hyoung Jin; Kim, Hy-Sook; Park, Sang-Yoon

    2007-08-01

    Primary Ewing's sarcoma-primitive neuroectodermal tumor (ES-PNET) of the uterus is an extremely rare malignancy. A 30-year-old Korean woman presented with abnormal uterine bleeding with uterine enlargement. A computed tomography (CT) scan and magnetic resonance imaging (MRI) of the abdomen and pelvis showed a huge uterine mass measuring 18 x 20 x 21 cm, metastasis to both pelvic and para-aortic lymph nodes, and omental infiltration. The pathology report of the uterine mass described a uniformly hypercellular tumor, which was arranged in diffuse solid sheets of uniform, small, rounded, and sometimes spindle-shaped cells, with scanty cytoplasm. Immunohistochemically, the mass tested positive for vimentin, CD99, and chromogranin. The patient received several courses of combination chemotherapy and radiotherapy but died from tumor progression 16 months after the initial diagnosis. This is a rare case of primary uterine ES-PNET in a woman of reproductive age. A review of the literature indicates that primary uterine ES-PNET requires early diagnosis and multimodality treatment including surgery, chemotherapy, and radiotherapy. The behavior of this tumor is potentially aggressive.

  17. PTEN and DMBT1 homozygous deletion and expression in medulloblastomas and supratentorial primitive neuroectodermal tumors.

    Science.gov (United States)

    Inda, María Mar; Mercapide, Javier; Muñoz, Jorge; Coullin, Philippe; Danglot, Giséle; Tuñon, Teresa; Martínez-Peñuela, José María; Rivera, José María; Burgos, Juan J; Bernheim, Alain; Castresana, Javier S

    2004-12-01

    Medulloblastoma, which accounts for 20-25% of all childhood brain tumors, is defined as a primitive neuroectodermal tumor (PNET) located in the cerebellum. Supratentorial PNET are less frequent than medulloblastoma. But their clinical outcome is worse than in medulloblastomas. Chromosome 10q contains at least 2 tumor suppressor genes that might play a role in brain tumor development: PTEN and DMBT1. The aim of this study was to compare the status of homozygous deletion and expression of PTEN and DMBT1 genes in PNET primary tumor samples and cell lines. Homozygous deletions of PTEN and DMBT1 were studied in 32 paraffin-embedded PNET samples (23 medulloblastomas and 9 supratentorial PNET) and in 7 PNET cell lines, by differential PCR and by FISH. PTEN homozygous losses were demonstrated in 7 medulloblastomas (32%) and in no supratentorial PNET, while homozygous deletions of DMBT1 appeared in 1 supratentorial PNET (20%) and in 7 medulloblastomas (33%). No homozygous deletion of PTEN or DMBT1 was detected in any of the PNET cell lines either by differential PCR or by FISH. Expression study of the 2 genes was performed in the 7 PNET cell lines by RT-PCR. One PNET cell line lacked PTEN and DMBT1 expression, while 2 medulloblastoma cell lines did not express DMBT1. Our results add some positive data to the hypothesis that supratentorial PNETs and medulloblastomas might be genetically different.

  18. Genetic heterogeneity in supratentorial and infratentorial primitive neuroectodermal tumours of the central nervous system.

    Science.gov (United States)

    Inda, M M; Perot, C; Guillaud-Bataille, M; Danglot, G; Rey, J A; Bello, M J; Fan, X; Eberhart, C; Zazpe, I; Portillo, E; Tuñón, T; Martínez-Peñuela, J M; Bernheim, A; Castresana, J S

    2005-12-01

    Medulloblastoma (MB), a kind of infratentorial primitive neuroectodermal tumour (PNET), is the most frequent malignant brain tumour in childhood. In contrast, supratentorial PNET (sPNET) are very infrequent tumours, but they are histologically similar to MB, although they present a worse clinical outcome. We investigated the differences in genetic abnormalities between sPNET and MB. We analysed 20 central PNET (14 MB and six sPNET) by conventional comparative genomic hybridization (CGH) in order to determine whether a different genetic profile for each tumour exists. Isochromosome 17q was detected in four of the 14 MB cases, but not in any sPNET. Gains at 17q and 7 happened more frequently in MB, and those at 1q in sPNET. Losses at chromosome 10 were detected only in MB, while losses at 16p and 19p happened more frequently in sPNET. A new amplification site, on 4q12, was detected in two MB. Central PNET are a heterogeneous group of tumours from the genetic point of view. The present and previous data, together with further results from larger series, might contribute to the establishment of specific treatments for supratentorial and infratentorial PNET.

  19. Data Management for the Internet of Things: Design Primitives and Solution

    Science.gov (United States)

    Abu-Elkheir, Mervat; Hayajneh, Mohammad; Ali, Najah Abu

    2013-01-01

    The Internet of Things (IoT) is a networking paradigm where interconnected, smart objects continuously generate data and transmit it over the Internet. Much of the IoT initiatives are geared towards manufacturing low-cost and energy-efficient hardware for these objects, as well as the communication technologies that provide objects interconnectivity. However, the solutions to manage and utilize the massive volume of data produced by these objects are yet to mature. Traditional database management solutions fall short in satisfying the sophisticated application needs of an IoT network that has a truly global-scale. Current solutions for IoT data management address partial aspects of the IoT environment with special focus on sensor networks. In this paper, we survey the data management solutions that are proposed for IoT or subsystems of the IoT. We highlight the distinctive design primitives that we believe should be addressed in an IoT data management solution, and discuss how they are approached by the proposed solutions. We finally propose a data management framework for IoT that takes into consideration the discussed design elements and acts as a seed to a comprehensive IoT data management solution. The framework we propose adapts a federated, data- and sources-centric approach to link the diverse Things with their abundance of data to the potential applications and services that are envisioned for IoT. PMID:24240599

  20. Multiple Ewing Sarcoma/Primitive Neuroectodermal Tumors in the Mediastinum: A Case Report and Literature Review.

    Science.gov (United States)

    Bae, Sung Hwan; Hwang, Jung Hwa; Da Nam, Bo; Kim, Hyun Jo; Kim, Ki-Up; Kim, Dong Won; Choi, In Ho

    2016-02-01

    Ewing sarcoma/primitive neuroectodermal tumors (ES/PNET) are high-grade malignant neoplasms. These malignancies present very rare tumors of thoracopulmonary area and even rarer in the mediastinum. In our knowledge, ES/PNET presented with multiple mediastinal masses has not been reported previously. We experienced a case of a 42-year-old man presented with gradual onset of left-side pleuritic chest pain. A contrast-enhanced chest computed tomography (CT) scan showed separate 2 large heterogeneously enhancing masses in each anterior and middle mediastinum of the left hemithorax. Positron emission tomography-computed tomography (PET-CT) scan revealed high fluorodeoxyglucose (FDG) uptake in the mediastinal masses. After surgical excision for the mediastinal masses, both of the masses were diagnosed as the ES/PNET group of tumors on the histopathologic examination. The patient refused postoperative adjuvant chemotherapy and came back with local tumor recurrence and distant metastasis on 4-month follow-up after surgical resection. We report this uncommon form of ES/PNET. We are to raise awareness that this rare malignancy should be considered as a differential diagnosis of the malignant mediastinal tumors and which can be manifested as multiple masses in a patient. Understanding this rare entity of extra-skeletal ES/PNET and characteristic imaging findings can help radiologists and clinicians to approach proper diagnosis and better management for this highly malignant tumor.

  1. Isotopic and Chemical Evidence for Primitive Aqueous Alteration in the Tagish Lake Meteorite

    Science.gov (United States)

    Sakuma, Keisuke; Hidaka, Hiroshi; Yoneda, Shigekazu

    2018-01-01

    Aqueous alteration is one of the primitive activities that occurred on meteorite parent bodies in the early solar system. The Tagish Lake meteorite is known to show an intense parent body aqueous alteration signature. In this study, quantitative analyses of the alkaline elements and isotopic analyses of Sr and Ba from acid leachates of TL (C2-ungrouped) were performed to investigate effects of aqueous alteration. The main purpose of this study is to search for isotopic evidence of extinct 135Cs from the Ba isotopic analyses in the chemical separates from the Tagish Lake meteorite. Barium isotopic data from the leachates show variable 135Ba isotopic anomalies (ε = ‑2.6 ∼ +3.6) which correlatewith 137Ba and 138Ba suggesting a heterogeneous distribution of s- and r-rich nucleosynthetic components in the early solar system. The 87Rb–87Sr and 135Cs–135Ba decay systems on TL in this study do not provide any chronological information. The disturbance of the TL chronometers is likely a reflection of the selective dissolution of Cs and Rb given the relatively higher mobility of Cs and Rb compared to Ba and Sr, respectively, during fluid mineral interactions.

  2. Primitive robotic procedures: automotions for medical liquids in 12th century Asia minor.

    Science.gov (United States)

    Penbegul, Necmettin; Atar, Murat; Kendirci, Muammer; Bozkurt, Yasar; Hatipoglu, Namık Kemal; Verit, Ayhan; Kadıoglu, Ates

    2014-12-30

    In recent years, day by day, robotic surgery applications have increase their role in our medical life. In this article, we reported the discovery of the first primitive robotic applications as automatic machines for the sensitive calculation of liquids such as blood in the literature. Al-Jazari who wrote the book "Elcâmi 'Beyne'l - 'ilm ve'l - 'amel en-nâfi 'fi es-sınaâ 'ti'l - hiyel", lived in Anatolian territory between 1136 and 1206. In this book that was written in the twelfth century, Al-Jazari described nearly fifty graphics of robotic machines and six of them that were designed for medical purposes. We found that some of the robots mentioned in this book are related to medical applications. This book reviews approximately 50 devices, including water clocks, candle clocks, ewers, various automata used for amusement in drink assemblies, automata used for ablution, blood collection tanks, fountains, music devices, devices for water lifting, locks, a protractor, a boat-shaped water clock, and the gate of Diyarbakir City in south-east of Turkey, actually in northern Mesopotamia. We found that automata used for ablution and blood collection tanks were related with medical applications; therefore, we will describe these robots.

  3. Effective screening length and quasiuniversality for the restricted primitive model of an electrolyte solution.

    Science.gov (United States)

    Janecek, Jirí; Netz, Roland R

    2009-02-21

    Monte Carlo simulations for the restricted primitive model of an electrolyte solution above the critical temperature are performed at a wide range of concentrations and temperatures. Thermodynamic properties such as internal energy, osmotic coefficient, activity coefficient, as well as spatial correlation functions are determined. These observables are used to investigate whether quasiuniversality in terms of an effective screening length exists, similar to the role played by the effective electron mass in solid-state physics. To that end, an effective screening length is extracted from the asymptotic behavior of the Fourier-transformed charge-correlation function and plugged into the Debye-Huckel limiting expressions for various thermodynamic properties. Comparison with numerical results is favorable, suggesting that correlation and other effects not captured on the Debye-Huckel limiting level can be successfully incorporated by a single effective parameter while keeping the functional form of Debye-Huckel expressions. We also compare different methods to determine mean ionic activity coefficient in molecular simulations and check the internal consistency of the numerical data.

  4. BigDebug: Debugging Primitives for Interactive Big Data Processing in Spark.

    Science.gov (United States)

    Gulzar, Muhammad Ali; Interlandi, Matteo; Yoo, Seunghyun; Tetali, Sai Deep; Condie, Tyson; Millstein, Todd; Kim, Miryung

    2016-05-01

    Developers use cloud computing platforms to process a large quantity of data in parallel when developing big data analytics. Debugging the massive parallel computations that run in today's data-centers is time consuming and error-prone. To address this challenge, we design a set of interactive, real-time debugging primitives for big data processing in Apache Spark, the next generation data-intensive scalable cloud computing platform. This requires re-thinking the notion of step-through debugging in a traditional debugger such as gdb, because pausing the entire computation across distributed worker nodes causes significant delay and naively inspecting millions of records using a watchpoint is too time consuming for an end user. First, BIGDEBUG's simulated breakpoints and on-demand watchpoints allow users to selectively examine distributed, intermediate data on the cloud with little overhead. Second, a user can also pinpoint a crash-inducing record and selectively resume relevant sub-computations after a quick fix. Third, a user can determine the root causes of errors (or delays) at the level of individual records through a fine-grained data provenance capability. Our evaluation shows that BIGDEBUG scales to terabytes and its record-level tracing incurs less than 25% overhead on average. It determines crash culprits orders of magnitude more accurately and provides up to 100% time saving compared to the baseline replay debugger. The results show that BIGDEBUG supports debugging at interactive speeds with minimal performance impact.

  5. Flotillins are involved in the polarization of primitive and mature hematopoietic cells.

    Directory of Open Access Journals (Sweden)

    Lawrence Rajendran

    Full Text Available BACKGROUND: Migration of mature and immature leukocytes in response to chemokines is not only essential during inflammation and host defense, but also during development of the hematopoietic system. Many molecules implicated in migratory polarity show uniform cellular distribution under non-activated conditions, but acquire a polarized localization upon exposure to migratory cues. METHODOLOGY/PRINCIPAL FINDINGS: Here, we present evidence that raft-associated endocytic proteins (flotillins are pre-assembled in lymphoid, myeloid and primitive hematopoietic cells and accumulate in the uropod during migration. Furthermore, flotillins display a polarized distribution during immunological synapse formation. Employing the membrane lipid-order sensitive probe Laurdan, we show that flotillin accumulation in the immunological synapse is concomittant with membrane ordering in these regions. CONCLUSIONS: Together with the observation that flotillin polarization does not occur in other polarized cell types such as polarized epithelial cells, our results suggest a specific role for flotillins in hematopoietic cell polarization. Based on our results, we propose that in hematopoietic cells, flotillins provide intrinsic cues that govern segregation of certain microdomain-associated molecules during immune cell polarization.

  6. Primitive neuroectodermal tumors of kidney: Our experience in a tertiary care center.

    Science.gov (United States)

    Seth, A; Mahapatra, S K; Nayak, B; Saini, A K; Biswas, B

    2016-01-01

    Primitive neuroectodermal tumors (PNET) are rare highly aggressive neoplasms. The diagnosis is made by histopathology with the support of immunohistochemistry (IHC) and cytogenetics. The aggressive multimodality treatment is recommended for the management of these tumors. The purpose of our study is to review our experiences in the diagnoses and treatment of PNET of the kidneys. We retrospectively reviewed the data of all the patients, who were treated for the PNET of the kidneys at our institute between April and March 2011 and compared with the available literature. A total of eight patients were treated for PNET of the kidney. Out of the eight patients, four were males and four females. Nearly 50% of our patients had inferior vena caval thrombus at the time of presentation. The diagnosis was made on histopathology supported by IHC. Out of the eight patients, one patient had intraoperative death due to massive pulmonary thromboembolism and another died on the 7th post-operative day due to disseminated intravascular coagulation and multiorgan failure. Rest six patients were treated with post-operative chemotherapy or a combination of chemotherapy and radiotherapy. For these six patients, overall median survival was 45 months with a 3 year disease-free survival of 66% and 5 year survival of 44%. PNET of the kidneys are rare peripheral neuroectodermal tumors with an aggressive clinical course. These tumors carry a very poor prognosis. An aggressive treatment approach using a combination of surgery, chemotherapy and radiotherapy is recommended for a reasonable survival in these tumors.

  7. Data management for the internet of things: design primitives and solution.

    Science.gov (United States)

    Abu-Elkheir, Mervat; Hayajneh, Mohammad; Ali, Najah Abu

    2013-11-14

    The Internet of Things (IoT) is a networking paradigm where interconnected, smart objects continuously generate data and transmit it over the Internet. Much of the IoT initiatives are geared towards manufacturing low-cost and energy-efficient hardware for these objects, as well as the communication technologies that provide objects interconnectivity. However, the solutions to manage and utilize the massive volume of data produced by these objects are yet to mature. Traditional database management solutions fall short in satisfying the sophisticated application needs of an IoT network that has a truly global-scale. Current solutions for IoT data management address partial aspects of the IoT environment with special focus on sensor networks. In this paper, we survey the data management solutions that are proposed for IoT or subsystems of the IoT. We highlight the distinctive design primitives that we believe should be addressed in an IoT data management solution, and discuss how they are approached by the proposed solutions. We finally propose a data management framework for IoT that takes into consideration the discussed design elements and acts as a seed to a comprehensive IoT data management solution. The framework we propose adapts a federated, data- and sources-centric approach to link the diverse Things with their abundance of data to the potential applications and services that are envisioned for IoT.

  8. A genus-level taxonomic review of primitively segmented spiders (Mesothelae, Liphistiidae

    Directory of Open Access Journals (Sweden)

    Xu Xin

    2015-03-01

    Full Text Available The spider suborder Mesothelae, containing a single extant family Liphistiidae, represents a species-poor and ancient lineage. These are conspicuous spiders that primitively retain a segmented abdomen and appendage-like spinnerets. While their classification history is nearly devoid of phylogenetic hypotheses, we here revise liphistiid genus level taxonomy based on original sampling throughout their Asian range, and on the evidence from a novel molecular phylogeny. By combining morphological and natural history evidence with phylogenetic relationships in the companion paper, we provide strong support for the monophyly of Liphistiidae, and the two subfamilies Liphistiinae and Heptathelinae. While the former only contains Liphistius Schiödte, 1849, a genus distributed in Indonesia (Sumatra, Laos, Malaysia, Myanmar, Thailand, we recognize and diagnose seven heptatheline genera, all but three removed from the synonymy of Heptathela: i Ganthela Xu & Kuntner, gen. n. with the type species G. yundingensis Xu, sp. n. is known from Fujian and Jiangxi, China; ii a rediagnosed Heptathela Kishida, 1923 is confined to the Japanese islands (Kyushu and Okinawa; iii Qiongthela Xu & Kuntner, gen. n. with the type species Q. baishensis Xu, sp. n. is distributed disjunctly in Hainan, China and Vietnam; iv Ryuthela Haupt, 1983 is confined to the Ryukyu archipelago (Japan; v Sinothela Haupt, 2003 inhabits Chinese areas north of Yangtze; vi Songthela Ono, 2000 inhabits southwest China and northern Vietnam; and vii Vinathela Ono, 2000 (Abcathela Ono, 2000, syn. n.; Nanthela Haupt, 2003, syn. n. is known from southeast China and Vietnam.

  9. A control theory approach to the analysis and synthesis of the experimentally observed motion primitives.

    Science.gov (United States)

    Nori, Francesco; Frezza, Ruggero

    2005-11-01

    Recent experiments on frogs and rats, have led to the hypothesis that sensory-motor systems are organized into a finite number of linearly combinable modules; each module generates a motor command that drives the system to a predefined equilibrium. Surprisingly, in spite of the infiniteness of different movements that can be realized, there seems to be only a handful of these modules. The structure can be thought of as a vocabulary of "elementary control actions". Admissible controls, which in principle belong to an infinite dimensional space, are reduced to the linear vector space spanned by these elementary controls. In the present paper we address some theoretical questions that arise naturally once a similar structure is applied to the control of nonlinear kinematic chains. First of all, we show how to choose the modules so that the system does not loose its capability of generating a "complete" set of movements. Secondly, we realize a "complete" vocabulary with a minimal number of elementary control actions. Subsequently, we show how to modify the control scheme so as to compensate for parametric changes in the system to be controlled. Remarkably, we construct a set of modules with the property of being invariant with respect to the parameters that model the growth of an individual. Robustness against uncertainties is also considered showing how to optimally choose the modules equilibria so as to compensate for errors affecting the system. Finally, the motion primitive paradigm is extended to locomotion and a related formalization of internal (proprioceptive) and external (exteroceptive) variables is given.

  10. On non-primitively divergent vertices of Yang-Mills theory

    Energy Technology Data Exchange (ETDEWEB)

    Huber, Markus Q. [Institute of Physics, University of Graz, NAWI Graz (Austria)

    2017-11-15

    Two correlation functions of Yang-Mills beyond the primitively divergent ones, the two-ghost-two-gluon and the four-ghost vertices, are calculated and their influence on lower vertices is examined. Their full (transverse) tensor structure is taken into account. As input, a solution of the full two-point equations - including two-loop terms - is used that respects the resummed perturbative ultraviolet behavior. A clear hierarchy is found with regard to the color structure that reduces the number of relevant dressing functions. The impact of the two-ghost-two-gluon vertex on the three-gluon vertex is negligible, which is explained by the fact that all non-small dressing functions drop out due to their color factors. Only in the ghost-gluon vertex a small net effect below 2% is seen. The four-ghost vertex is found to be extremely small in general. Since these two four-point functions do not enter into the propagator equations, these findings establish their small overall effect on lower correlation functions. (orig.)

  11. Generalized large-scale semigeostrophic approximations for the f-plane primitive equations

    International Nuclear Information System (INIS)

    Oliver, Marcel; Vasylkevych, Sergiy

    2016-01-01

    We derive a family of balance models for rotating stratified flow in the primitive equation (PE) setting. By construction, the models possess conservation laws for energy and potential vorticity and are formally of the same order of accuracy as Hoskins’ semigeostrophic equations. Our construction is based on choosing a new coordinate frame for the PE variational principle in such a way that the consistently truncated Lagrangian degenerates. We show that the balance relations so obtained are elliptic when the fluid is stably stratified and certain smallness assumptions are satisfied. Moreover, the potential temperature can be recovered from the potential vorticity via inversion of a non-standard Monge–Ampère problem which is subject to the same ellipticity condition. While the present work is entirely formal, we conjecture, based on a careful rewriting of the equations of motion and a straightforward derivative count, that the Cauchy problem for the balance models is well posed subject to conditions on the initial data. Our family of models includes, in particular, the stratified analog of the L 1 balance model of Salmon. (paper)

  12. Bax function in the absence of mitochondria in the primitive protozoan Giardia lamblia.

    Directory of Open Access Journals (Sweden)

    Adrian B Hehl

    Full Text Available Bax-induced permeabilization of the mitochondrial outer membrane and release of cytochrome c are key events in apoptosis. Although Bax can compromise mitochondria in primitive unicellular organisms that lack a classical apoptotic machinery, it is still unclear if Bax alone is sufficient for this, or whether additional mitochondrial components are required. The protozoan parasite Giardia lamblia is one of the earliest branching eukaryotes and harbors highly degenerated mitochondrial remnant organelles (mitosomes that lack a genome. Here we tested whether human Bax expressed in Giardia can be used to ablate mitosomes. We demonstrate that these organelles are neither targeted, nor compromised, by Bax. However, specialized compartments of the regulated secretory pathway are completely ablated by Bax. As a consequence, maturing cyst wall proteins that are sorted into these organelles are released into the cytoplasm, causing a developmental arrest and cell death. Interestingly, this ectopic cargo release is dependent on the carboxy-terminal 22 amino acids of Bax, and can be prevented by the Bax-inhibiting peptide Ku70. A C-terminally truncated Bax variant still localizes to secretory organelles, but is unable to permeabilize these membranes, uncoupling membrane targeting and cargo release. Even though mitosomes are too diverged to be recognized by Bax, off-target membrane permeabilization appears to be conserved and leads to cell death completely independently of mitochondria.

  13. Chemotaxis of primitive hematopoietic cells in response to stromal cell–derived factor-1

    Science.gov (United States)

    Jo, Deog-Yeon; Rafii, Shahin; Hamada, Tsuneyoshi; Moore, Malcolm A.S.

    2000-01-01

    Stromal cell–derived factor-1 (SDF-1) provides a potent chemotactic stimulus for CD34+ hematopoietic cells. We cultured mobilized peripheral blood (PB) and umbilical cord blood (CB) for up to 5 weeks and examined the migratory activity of cobblestone area–forming cells (CAFCs) and long-term culture–initiating cells (LTC-ICs) in a transwell assay. In this system, SDF-1 or MS-5 marrow stromal cells placed in the lower chamber induced transmembrane and transendothelial migration by 2- and 5-week-old CAFCs and LTC-ICs in 3 hours. Transmigration was blocked by preincubation of input CD34+ cells with antibody to CXCR4. Transendothelial migration of CB CAFCs and LTC-ICs was higher than that of PB. We expanded CD34+ cells from CB in serum-free medium with thrombopoietin, flk-2 ligand, and c-kit ligand, with or without IL-3 and found that CAFCs cultured in the absence of IL-3 had a chemotactic response equivalent to noncultured cells, even after 5 weeks. However, addition of IL-3 to the culture reduced this response by 20–50%. These data indicate that SDF-1 induces chemotaxis of primitive hematopoietic cells signaling through CXCR4 and that the chemoattraction could be downmodulated by culture ex vivo. PMID:10619866

  14. Semantics of immersive web through its architectural structure and graphic primitives

    Directory of Open Access Journals (Sweden)

    Rubén González Crespo

    2010-12-01

    Full Text Available Currently, practices and tools for computer-aided three-dimensional design, do not allow the semantic description of objects constructed in some cases specified notations as handling layers, or labeling of each development itself. The lack of a standard for the description of the elements represents a major drawback for using advanced three-dimensional environments such as the automation of search and construction processes that require semantic knowledge of its elements.This project proposes the development the semantic composition from the hierarchy of three-dimensional visualization of graphics primitives used to construct three-dimensional objects, taking into account the geometric composition architecture of standard 19775-1 of the International Electrotechnical Commission of the International Organization for StandardizationFor the development of semantic composition use the methodology methontology proposed by the Universidad Politécnica de Madrid, because it allows the construction of ontologies about specific domains, limiting the domain by defining classes and subclasses, relationships and the generation of instances a framework for resource description on web ontology language.

  15. Differences in exterior conformation between primitive, Half-bred, and Thoroughbred horses: anatomic-breeding approach.

    Science.gov (United States)

    Komosa, M; Frackowiak, H; Purzyc, H; Wojnowska, M; Gramacki, A; Gramacki, J

    2013-04-01

    The study included 249 horses belonging to 3 horse breeds. Konik horses, comprising the first group, is an example of a breed similar to the extinct Tarpan. In our study, these horses were taken to be a primitive anatomical model of the horse body. The other groups comprised the Polish Half-bred horse and Thoroughbred horse. The biometric characteristics of the horses were compared based on 24 indices. The aim of the paper was to find a reduced set of indices that can be used to determine group membership of the horses. To do this, we used statistical methods to find the most important indices that best discriminate breeds from each other. Chi-squared statistics, linear discriminant analysis, logistic regression, and 1-way ANOVA showed that the discrimination among groups of horses is connected with these 5 indices: scapula, smaller trunk (distance between tubercle of humerus and coxal tuber), greater trunk (distance between tubercle of humerus and ischial tuberosity), metacarpus circumference, and hind autopodium-smaller trunk. Thoroughbred and Half-bred horses are clearly different in exterior conformation from Konik horses. The differences between Thoroughbred and Half-bred horses are more subtle. The conformation of Thoroughbreds is jointly determined by relatively small differences in a range of features.

  16. A Case of Renal Primitive Neuroectodermal Tumor Confirmed by Fluorescence in situ Hybridization

    Directory of Open Access Journals (Sweden)

    Toshiki Etani

    2015-04-01

    Full Text Available Primitive neuroectodermal tumor (PNET is a member of the Ewing's sarcoma family of tumors (ESFT. We report a case of PNET in a 66-year-old male who presented with a large solid tumor within the parenchyma of the middle pole of the left kidney with metastases to the left adrenal gland and right ischium. A fine-needle biopsy was performed and showed a small round cell tumor. Results of immunohistochemical staining suggested this tumor belonged to ESFT. Preoperative VDC-IE (combined vincristine, doxorubicin and cyclophosphamide followed by another combination of ifosfamide and etoposide chemotherapy and left radical nephrectomy and adrenalectomy were performed. The histopathological findings of the resected tumor were similar to those in the biopsy specimen, but the results of AE1/AE3 were different. For the diagnosis, fluorescence in situ hybridization was performed. Split signals of the EWSR1 gene were detected, and transmission electron microscopy showed neuroendocrine granules and microtubules. The final diagnosis of this tumor was PNET of the kidney.

  17. Effective convergence to complete orbital bases and to the atomic Hartree--Fock limit through systematic sequences of Gaussian primitives

    International Nuclear Information System (INIS)

    Schmidt, M.W.; Ruedenberg, K.

    1979-01-01

    Optimal starting points for expanding molecular orbitals in terms of atomic orbitals are the self-consistent-field orbitals of the free atoms and accurate information about the latter is essential for the construction of effective AO bases for molecular calculations. For expansions of atomic SCF orbitals in terms of Gaussian primitives, which are of particular interest for applications in polyatomic quantum chemistry, previous information has been limited in accuracy. In the present investigation a simple procedure is given for finding expansions of atomic self-consistent-field orbitals in terms of Gaussian primitives to arbitrarily high accuracy. The method furthermore opens the first avenue so far for approaching complete basis sets through systematic sequences of atomic orbitals

  18. Primitive neuroectodermal tumor of the zygomaticoorbital complex: a rare location and ways of surgical repair of the area

    Directory of Open Access Journals (Sweden)

    Ch. R. Ragimov

    2015-01-01

    Full Text Available Primitive neuroectodermal tumor in the zygomaticoorbital region is a rare neoplasm of the head and neck. Due to the necessity for wide radical excision of a primary tumor, there may be serious functional and cosmetic disorders that substantially affect quality of life in patients. Restoration of this region is one of the challenges of reconstructive surgery because of the specific features of the relief of bone structures. The paper describes a clinical case of the site of primitive neuroectodermal tumor in the zygomaticoorbital complex and a method for repairing postresectional defect and completely recovering the function of the organ of vision and aesthetic parameters of the face.

  19. Fast concurrent array-based stacks, queues and deques using fetch-and-increment-bounded, fetch-and-decrement-bounded and store-on-twin synchronization primitives

    Science.gov (United States)

    Chen, Dong; Gara, Alana; Heidelberger, Philip; Kumar, Sameer; Ohmacht, Martin; Steinmacher-Burow, Burkhard; Wisniewski, Robert

    2014-09-16

    Implementation primitives for concurrent array-based stacks, queues, double-ended queues (deques) and wrapped deques are provided. In one aspect, each element of the stack, queue, deque or wrapped deque data structure has its own ticket lock, allowing multiple threads to concurrently use multiple elements of the data structure and thus achieving high performance. In another aspect, new synchronization primitives FetchAndIncrementBounded (Counter, Bound) and FetchAndDecrementBounded (Counter, Bound) are implemented. These primitives can be implemented in hardware and thus promise a very fast throughput for queues, stacks and double-ended queues.

  20. Learning and Chaining of Motor Primitives for Goal-directed Locomotion of a Snake-Like Robot with Screw-Drive Units

    DEFF Research Database (Denmark)

    Chatterjee, Sromona; Nachstedt, Timo; Tamosiunaite, Minija

    2015-01-01

    -directed locomotion for the robot. The behavioural primitives of the robot are generated using a reinforcement learning approach called "Policy Improvement with Path Integrals" (PI2). PI2 is numerically simple and has the ability to deal with high-dimensional systems. Here, PI2 is used to learn the robot’s motor...... controls by finding proper locomotion control parameters, like joint angles and screw-drive unit velocities, in a coordinated manner for different goals. Thus, it is able to generate a large repertoire of motor primitives, which are selectively stored to form a primitive library. The learning process...

  1. Preliminary study on the way of formation of amino acids on primitive earth under non-reducing conditions

    International Nuclear Information System (INIS)

    Shi Huaibin; Shao Chunlin; Yu Zengliang

    2001-01-01

    Low energy ions were produced by N 2 glow discharge. The positive ions were accelerated into three kinds of carboxylate solution to induce chemical reactions. HPLC analysis showed that N was deposited into the solution, ammonia and amino acids were produced by such kind of implantation. The time-response of amounts of amino acids was given. The results presented a new way for the production of ammonia and amino acids under primitive earth conditions

  2. Origin of primitive ocean island basalts by crustal gabbro assimilation and multiple recharge of plume-derived melts

    Science.gov (United States)

    Borisova, Anastassia Y.; Bohrson, Wendy A.; Grégoire, Michel

    2017-07-01

    Chemical Geodynamics relies on a paradigm that the isotopic composition of ocean island basalt (OIB) represents equilibrium with its primary mantle sources. However, the discovery of huge isotopic heterogeneity within olivine-hosted melt inclusions in primitive basalts from Kerguelen, Iceland, Hawaii and South Pacific Polynesia islands implies open-system behavior of OIBs, where during magma residence and transport, basaltic melts are contaminated by surrounding lithosphere. To constrain the processes of crustal assimilation by OIBs, we employed the Magma Chamber Simulator (MCS), an energy-constrained thermodynamic model of recharge, assimilation and fractional crystallization. For a case study of the 21-19 Ma basaltic series, the most primitive series ever found among the Kerguelen OIBs, we performed sixty-seven simulations in the pressure range from 0.2 to 1.0 GPa using compositions of olivine-hosted melt inclusions as parental magmas, and metagabbro xenoliths from the Kerguelen Archipelago as wallrock. MCS modeling requires that the assimilant is anatectic crustal melts (P2O5 ≤ 0.4 wt.% contents) derived from the Kerguelen oceanic metagabbro wallrock. To best fit the phenocryst assemblage observed in the investigated basaltic series, recharge of relatively large masses of hydrous primitive basaltic melts (H2O = 2-3 wt%; MgO = 7-10 wt.%) into a middle crustal chamber at 0.2 to 0.3 GPa is required. Our results thus highlight the important impact that crustal gabbro assimilation and mantle recharge can have on the geochemistry of mantle-derived olivine-phyric OIBs. The importance of crustal assimilation affecting primitive plume-derived basaltic melts underscores that isotopic and chemical equilibrium between ocean island basalts and associated deep plume mantle source(s) may be the exception rather than the rule.

  3. Ionic and Wigner Glasses, Superionic Conductors, and Spinodal Electrostatic Gels: Dynamically Arrested Phases of the Primitive Model

    International Nuclear Information System (INIS)

    Sanchez-Diaz, L. E.; Juarez-Maldonado, R.; Vizcarra-Rendon, A.

    2009-01-01

    Based on the recently proposed self-consistent generalized Langevin equation theory of dynamic arrest, in this letter we show that the ergodic-nonergodic phase diagram of a classical mixture of charged hard spheres (the so-called 'primitive model' of ionic solutions and molten salts) includes arrested phases corresponding to nonconducting ionic glasses, partially arrested states that represent solid electrolytes (or 'superionic' conductors), low-density colloidal Wigner glasses, and low-density electrostatic gels associated with arrested spinodal decomposition.

  4. From Realistic to Simple Models of Associating Fluids. II. Primitive Models of Ammonia, Ethanol and Models of Water Revisited

    Czech Academy of Sciences Publication Activity Database

    Vlček, Lukáš; Nezbeda, Ivo

    2004-01-01

    Roč. 102, č. 5 (2004), s. 485-497 ISSN 0026-8976 R&D Projects: GA ČR GA203/02/0764; GA AV ČR IAA4072303; GA AV ČR IAA4072309 Institutional research plan: CEZ:AV0Z4072921 Keywords : primitive model * association fluids * ethanol Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 1.406, year: 2004

  5. Achieving Performance Speed-up in FPGA Based Bit-Parallel Multipliers using Embedded Primitive and Macro support

    Directory of Open Access Journals (Sweden)

    Burhan Khurshid

    2015-05-01

    Full Text Available Modern Field Programmable Gate Arrays (FPGA are fast moving into the consumer market and their domain has expanded from prototype designing to low and medium volume productions. FPGAs are proving to be an attractive replacement for Application Specific Integrated Circuits (ASIC primarily because of the low Non-recurring Engineering (NRE costs associated with FPGA platforms. This has prompted FPGA vendors to improve the capacity and flexibility of the underlying primitive fabric and include specialized macro support and intellectual property (IP cores in their offerings. However, most of the work related to FPGA implementations does not take full advantage of these offerings. This is primarily because designers rely mainly on the technology-independent optimization to enhance the performance of the system and completely neglect the speed-up that is achievable using these embedded primitives and macro support. In this paper, we consider the technology-dependent optimization of fixed-point bit-parallel multipliers by carrying out their implementations using embedded primitives and macro support that are inherent in modern day FPGAs. Our implementation targets three different FPGA families viz. Spartan-6, Virtex-4 and Virtex-5. The implementation results indicate that a considerable speed up in performance is achievable using these embedded FPGA resources.

  6. The divergent fates of primitive hydrospheric water on Earth and Mars

    Science.gov (United States)

    Wade, Jon; Dyck, Brendan; Palin, Richard M.; Moore, James D. P.; Smye, Andrew J.

    2017-12-01

    Despite active transport into Earth’s mantle, water has been present on our planet’s surface for most of geological time. Yet water disappeared from the Martian surface soon after its formation. Although some of the water on Mars was lost to space via photolysis following the collapse of the planet’s magnetic field, the widespread serpentinization of Martian crust suggests that metamorphic hydration reactions played a critical part in the sequestration of the crust. Here we quantify the relative volumes of water that could be removed from each planet’s surface via the burial and metamorphism of hydrated mafic crusts, and calculate mineral transition-induced bulk-density changes at conditions of elevated pressure and temperature for each. The metamorphic mineral assemblages in relatively FeO-rich Martian lavas can hold about 25 per cent more structurally bound water than those in metamorphosed terrestrial basalts, and can retain it at greater depths within Mars. Our calculations suggest that in excess of 9 per cent by volume of the Martian mantle may contain hydrous mineral species as a consequence of surface reactions, compared to about 4 per cent by volume of Earth’s mantle. Furthermore, neither primitive nor evolved hydrated Martian crust show noticeably different bulk densities compared to their anhydrous equivalents, in contrast to hydrous mafic terrestrial crust, which transforms to denser eclogite upon dehydration. This would have allowed efficient overplating and burial of early Martian crust in a stagnant-lid tectonic regime, in which the lithosphere comprised a single tectonic plate, with only the warmer, lower crust involved in mantle convection. This provided an important sink for hydrospheric water and a mechanism for oxidizing the Martian mantle. Conversely, relatively buoyant mafic crust and hotter geothermal gradients on Earth reduced the potential for upper-mantle hydration early in its geological history, leading to water being retained

  7. Surgical treatment of primitive gastro-intestinal lymphomas: a systematic review

    Directory of Open Access Journals (Sweden)

    Cirocchi Roberto

    2011-11-01

    Full Text Available Abstract Primitive Gastrointestinal Lymphomas (PGIL are uncommon tumours, although time-trend analyses have demonstrated an increase. The role of surgery in the management of lymphoproliferative diseases has changed over the past 40 years. Nowadays their management is centred on systemic treatments as chemo-/radio- therapy. Surgery is restricted to very selected indications, always discussed in a multidisciplinary setting. The aim of this systematic review is to evaluate the actual role of surgery in the treatment of PGIL. A systematic review of literature was conducted according to the recommendations of The Cochrane Collaboration. Main outcomes analysed were overall survival (OS and disease free survival (DFS. There are currently 1 RCT and 4 non-randomised prospective controlled studies comparing surgical versus medical treatment for PGIL. Seven hundred and one patients were analysed, divided into two groups: 318 who underwent to surgery alone or associated with chemotherapy and/or radiotherapy (surgical group versus 383 who were treated with chemotherapy and/or radiotherapy (medical group. Despite the OS at 10 years between surgical and medical groups did not show relevant differences, the DFS was significantly better in the medical group (P = 0.00001. Accordingly a trend was noticed in the recurrence rate, which was lower in the medical group (6.06 vs. 8.57%; and an higher mortality was revealed in the surgical group (4.51% vs. 1.50%. The chemotherapy confirms its primary role in the management of PGIL as part of systemic treatment in the medical group. Surgery remains the treatment of choice in case of PGIL acutely complicated, although there is no evidence in literature regarding the utility of preventive surgery.

  8. Recurrent spinal primitive neuroectodermal tumor with brain and bone metastases: A case report.

    Science.gov (United States)

    Chen, Frank; Chiou, Shyh-Shin; Lin, Sheng-Fung; Lieu, Ann-Shung; Chen, Yi-Ting; Huang, Chih-Jen

    2017-11-01

    Primary spinal primitive neuroectodermal tumor (PNET) is relatively rare in all age groups, and the prognosis in most cases of spinal PNETs appears to be poor, with a median patient survival of 1 to 2 years. We present a case with recurrent spinal PNET with brain and bone metastases that was successfully treated by multimodality treatment. A 14-year-old teenage girl had suffered from progressive left upper back pain with bilateral lower legs weakness and numbness for 1 year. After treatment, left neck mass was noted 3 years later. Initially, magnetic resonance imaging (MRI) showed neurogenic tumor involving intradural extramedullary space of T5-T10. Pathology report showed PNET (World Health Organization grade IV) featuring lobules of neoplastic cells with round regular nuclei, high nucleus-to-cytoplasm ratio, and fibrillary cytoplasm. At the time of tumor recurrence, chest MRI then showed recurrent tumor at T2-T3 level of the epidural space with right neural foramina invasion. Brain MRI showed extensive bilateral calvarial metastases and leptomeningeal metastases in the right frontoparietal regions. Bone scan showed multiple bone metastases. T-spine tumor removal and adjuvant radiotherapy (RT) to T-spine tumor bed were performed in the initial treatment. After clinical tumor recurrence, tumor removal was done again. She then received chemotherapy followed by whole brain irradiation with hippocampal sparing with 35 gray in 20 fractions. After treatment, follow-up images showed that the disease was under control. There was no neurological sequela. She has survived more than 7 years from diagnosis and more than 4 years from recurrence to date. Multimodality treatments including operation, RT, and chemotherapy should be considered in the initial treatment planning, and salvage chemotherapy was useful in this case.

  9. From imitation to meaning: circuit plasticity and the acquisition of a primitive semantics.

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    Ricardo R Garcia

    2014-08-01

    Full Text Available The capacity for language is arguably the most remarkable innovation of the human brain. A relatively recent interpretation prescribes that part of the language-related circuits were co-opted from circuitry involved in hand control –the mirror neuron system, involved both in the perception and in the execution of voluntary grasping actions. A less radical view is that in early humans, communication was opportunistic and multimodal, using signs, vocalizations or whatever means available to transmit social information. However, one point that is not yet clear under either perspective is how learned communication acquired a semantic property thereby allowing us to name objects and eventually describe our surrounding environment. Here we suggest a scenario involving both manual gestures and learned vocalizations that led to the development of a primitive form of conventionalized reference. This proposal is based on comparative evidence gathered from other species and on neurolinguistic evidence in humans, which points to a crucial role for vocal learning in the early development of language. Firstly, the capacity to direct the attention of others to a common object may have been crucial for developing a consensual referential system. Pointing, which is a ritualized grasping gesture, may have been crucial to this end. Vocalizations also served to generate joint attention among conversants, especially when combined with gaze direction. Another contributing element was the development of pantomimic actions resembling events or animals. In conjunction with this mimicry, the development of plastic neural circuits that support complex, learned vocalizations was probably a significant factor in the evolution of conventionalized semantics in our species. Thus, vocal imitations of sounds, as in onomatopoeias (words whose sound resembles their meaning, are possibly supported by mirror system circuits, and may have been relevant in the acquisition of early

  10. Images from the Mind: BCI image reconstruction based on Rapid Serial Visual Presentations of polygon primitives

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    Luís F Seoane

    2015-04-01

    Full Text Available We provide a proof of concept for an EEG-based reconstruction of a visual image which is on a user's mind. Our approach is based on the Rapid Serial Visual Presentation (RSVP of polygon primitives and Brain-Computer Interface (BCI technology. In an experimental setup, subjects were presented bursts of polygons: some of them contributed to building a target image (because they matched the shape and/or color of the target while some of them did not. The presentation of the contributing polygons triggered attention-related EEG patterns. These Event Related Potentials (ERPs could be determined using BCI classification and could be matched to the stimuli that elicited them. These stimuli (i.e. the ERP-correlated polygons were accumulated in the display until a satisfactory reconstruction of the target image was reached. As more polygons were accumulated, finer visual details were attained resulting in more challenging classification tasks. In our experiments, we observe an average classification accuracy of around 75%. An in-depth investigation suggests that many of the misclassifications were not misinterpretations of the BCI concerning the users' intent, but rather caused by ambiguous polygons that could contribute to reconstruct several different images. When we put our BCI-image reconstruction in perspective with other RSVP BCI paradigms, there is large room for improvement both in speed and accuracy. These results invite us to be optimistic. They open a plethora of possibilities to explore non-invasive BCIs for image reconstruction both in healthy and impaired subjects and, accordingly, suggest interesting recreational and clinical applications.

  11. The divergent fates of primitive hydrospheric water on Earth and Mars.

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    Wade, Jon; Dyck, Brendan; Palin, Richard M; Moore, James D P; Smye, Andrew J

    2017-12-20

    Despite active transport into Earth's mantle, water has been present on our planet's surface for most of geological time. Yet water disappeared from the Martian surface soon after its formation. Although some of the water on Mars was lost to space via photolysis following the collapse of the planet's magnetic field, the widespread serpentinization of Martian crust suggests that metamorphic hydration reactions played a critical part in the sequestration of the crust. Here we quantify the relative volumes of water that could be removed from each planet's surface via the burial and metamorphism of hydrated mafic crusts, and calculate mineral transition-induced bulk-density changes at conditions of elevated pressure and temperature for each. The metamorphic mineral assemblages in relatively FeO-rich Martian lavas can hold about 25 per cent more structurally bound water than those in metamorphosed terrestrial basalts, and can retain it at greater depths within Mars. Our calculations suggest that in excess of 9 per cent by volume of the Martian mantle may contain hydrous mineral species as a consequence of surface reactions, compared to about 4 per cent by volume of Earth's mantle. Furthermore, neither primitive nor evolved hydrated Martian crust show noticeably different bulk densities compared to their anhydrous equivalents, in contrast to hydrous mafic terrestrial crust, which transforms to denser eclogite upon dehydration. This would have allowed efficient overplating and burial of early Martian crust in a stagnant-lid tectonic regime, in which the lithosphere comprised a single tectonic plate, with only the warmer, lower crust involved in mantle convection. This provided an important sink for hydrospheric water and a mechanism for oxidizing the Martian mantle. Conversely, relatively buoyant mafic crust and hotter geothermal gradients on Earth reduced the potential for upper-mantle hydration early in its geological history, leading to water being retained close to

  12. RASSF1A promoter is highly methylated in primitive neuroectodermal tumors of the central nervous system.

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    Inda, María-del-Mar; Castresana, Javier S

    2007-08-01

    Although cancer is rare in children, primary brain tumors constitute the most frequent location of solid tumors in childhood. Primitive neuroectodermal tumors (PNET) of the central nervous system can be divided into infratentorial PNET or medulloblastoma (MB), and supratentorial (sPNET) tumors. Although MB and sPNET are histologically similar, clinical evolution differs, sPNET being more aggressive than MB. Some studies have suggested that MB and sPNET present different molecular genetic aberrations. The RASSF1A (Ras Association Domain Family Protein 1) gene, located at 3p21.3, is highly methylated in multiple primary tumor samples, including neuroblastoma. In order to define whether there are genetic differences in the methylation frequency of RASSF1A between MB and sPNET, we analyzed 32 PNET paraffin-embedded samples (23 MB and 9 sPNET) by methylation specific polymerase chain reaction (MSP). We also analyzed RASSF1A expression by reverse transcription polymerase chain reaction in five PNET cell lines. All PNET cell lines showed lack of RASSF1A expression that was correlated with RASSF1A promoter hypermethylation. RASSF1A methylation was detected in 19 of 21 MB cases (91%) and in five of six sPNET samples (83%). Although the methylation frequency found in MB was slightly higher than in sPNET, no statistical differences were found for the RASSF1A hypermethylation frequency (P > 0.05) presented at MB versus sPNET. Therefore, the inactivation of the RASSF1A gene seems to be an important step in the tumorigenesis of PNET of the central nervous sytem. More studies should be performed in order to determine genetic differences between MB and sPNET.

  13. The Primitive Thylakoid-Less Cyanobacterium Gloeobacter Is a Common Rock-Dwelling Organism.

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    Jan Mareš

    Full Text Available Cyanobacteria are an ancient group of photosynthetic prokaryotes, which are significant in biogeochemical cycles. The most primitive among living cyanobacteria, Gloeobacter violaceus, shows a unique ancestral cell organization with a complete absence of inner membranes (thylakoids and an uncommon structure of the photosynthetic apparatus. Numerous phylogenetic papers proved its basal position among all of the organisms and organelles capable of plant-like photosynthesis (i.e., cyanobacteria, chloroplasts of algae and plants. Hence, G. violaceus has become one of the key species in evolutionary study of photosynthetic life. It also numbers among the most widely used organisms in experimental photosynthesis research. Except for a few related culture isolates, there has been little data on the actual biology of Gloeobacter, being relegated to an "evolutionary curiosity" with an enigmatic identity. Here we show that members of the genus Gloeobacter probably are common rock-dwelling cyanobacteria. On the basis of morphological, ultrastructural, pigment, and phylogenetic comparisons of available Gloeobacter strains, as well as on the basis of three new independent isolates and historical type specimen, we have produced strong evidence as to the close relationship of Gloeobacter to a long known rock-dwelling cyanobacterial morphospecies Aphanothece caldariorum. Our results bring new clues to solving the 40 year old puzzle of the true biological identity of Gloeobacter violaceus, a model organism with a high value in several biological disciplines. A probable broader distribution of Gloeobacter in common wet-rock habitats worldwide is suggested by our data, and its ecological meaning is discussed taking into consideration the background of cyanobacterial evolution. We provide observations of previously unknown genetic variability and phenotypic plasticity, which we expect to be utilized by experimental and evolutionary researchers worldwide.

  14. The role of the temporal pole in modulating primitive auditory memory.

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    Liu, Zhiliang; Wang, Qian; You, Yu; Yin, Peng; Ding, Hu; Bao, Xiaohan; Yang, Pengcheng; Lu, Hao; Gao, Yayue; Li, Liang

    2016-04-21

    Primitive auditory memory (PAM), which is recognized as the early point in the chain of the transient auditory memory system, faithfully maintains raw acoustic fine-structure signals for up to 20-30 milliseconds. The neural mechanisms underlying PAM have not been reported in the literature. Previous anatomical, brain-imaging, and neurophysiological studies have suggested that the temporal pole (TP), part of the parahippocampal region in the transitional area between perirhinal cortex and superior/inferior temporal gyri, is involved in auditory memories. This study investigated whether the TP plays a role in mediating/modulating PAM. The longest interaural interval (the interaural-delay threshold) for detecting a break in interaural correlation (BIC) embedded in interaurally correlated wideband noises was used to indicate the temporal preservation of PAM and examined in both healthy listeners and patients receiving unilateral anterior temporal lobectomy (ATL, centered on the TP) for treating their temporal lobe epilepsy (TLE). The results showed that patients with ATL were still able to detect the BIC even when an interaural interval was introduced, regardless of which ear was the leading one. However, in patient participants, the group-mean interaural-delay threshold for detecting the BIC under the contralateral-ear-leading (relative to the side of ATL) condition was significantly shorter than that under the ipsilateral-ear-leading condition. The results suggest that although the TP is not essential for integrating binaural signals and mediating the PAM, it plays a role in top-down modulating the PAM of raw acoustic fine-structure signals from the contralateral ear. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  15. Do endothelial cells belong to the primitive stem leukemic clone in CML? Role of extracellular vesicles.

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    Ramos, Teresa L; Sánchez-Abarca, Luis Ignacio; López-Ruano, Guillermo; Muntión, Sandra; Preciado, Silvia; Hernández-Ruano, Montserrat; Rosado, Belén; de las Heras, Natalia; Chillón, M Carmen; Hernández-Hernández, Ángel; González, Marcos; Sánchez-Guijo, Fermín; Del Cañizo, Consuelo

    2015-08-01

    The expression of BCR-ABL in hematopoietic stem cells is a well-defined primary event in chronic myeloid leukemia (CML). Some reports have described the presence of BCR-ABL on endothelial cells from CML patients, suggesting the origin of the disease in a primitive hemangioblastic cell. On the other hand, extracellular vesicles (EVs) released by CML leukemic cells are involved in the angiogenesis modulation process. In the current work we hypothesized that EVs released from BCR-ABL(+) cells may carry inside the oncogene that can be transferred to endothelial cells leading to the expression of both BCR-ABL transcript and the oncoprotein. EVs from K562 cells and plasma of newly diagnosed CML patients were isolated by ultracentrifugation. RT-PCR analysis detected the presence of BCR-ABL RNA in the EVs isolated from both K562 cells and plasma of CML patients. The incorporation of these EVs into endothelial cells was demonstrated by flow cytometry and fluorescence microscopy showed that after 24h of incubation most EVs were incorporated. BCR-ABL transcripts were detected in all experiments on endothelial cells incubated with EVs from both sources. The presence of BCR-ABL on endothelial cells incubated with Philadelphia(+) EVs was also confirmed by Western blot assays. In summary, endothelial cells acquire BCR-ABL RNA and the oncoprotein after incubation with EVs released from Ph(+) positive cells (either from K562 cells or from plasma of newly diagnosed CML patients). This results challenge the hypothesis that endothelial cells may be part of the Philadelphia(+) clone in CML. Copyright © 2015 Elsevier Ltd. All rights reserved.

  16. Examination of Multiple Lithologies Within the Primitive Ordinary Chondrite NWA 5717

    Science.gov (United States)

    Cato, M. J.; Simon, J. I.; Ross, D. K.; Morris, R. V.

    2017-01-01

    Northwest Africa 5717 is a primitive (subtype 3.05) ungrouped ordinary chondrite which contains two apparently distinct lithologies. In large cut meteorite slabs, the darker of these, lithology A, looks to host the second, much lighter in color, lithology B (upper left, Fig. 1). The nature of the boundary between the two is uncertain, ranging from abrupt to gradational and not always following particle boundaries. The distinction between the lithologies, beyond the obvious color differences, has been supported by a discrepancy in oxygen isotopes and an incongruity in the magnesium contents of chondrule olivine. Here, quantitative textural analysis and mineralogical methods have been used to investigate the two apparent lithologies within NWA 5717. Olivine grains contained in a thin section from NWA 7402, thought to be paired to 5717, were also measured to re-examine the distinct compositional range among the light and dark areas. Procedure: Particles from a high-resolution mosaic image of a roughly 13x15cm slice of NWA 5717 were traced in Adobe Photoshop. Due to the large size of the sample, visually representative regions of each lithology were chosen to be analyzed. The resulting layers of digitized particles were imported into ImageJ, which was used to measure their area, along with the axes, the angle from horizontal, and the centroid coordinates of ellipses fitted to each particle following the approach. Resulting 2D pixel areas were converted to spherical diameters employing the unfolding algorithm, which outputs a 3D particle size distribution based on digitized 2D size frequency data. Spatstat was used to create kernel density plots of the centroid coordinates for each region. X-ray compositional maps, microprobe analyses, and Mossbauer spectroscopy was conducted on a thin section of NWA 7402, tentatively paired to NWA 5717.

  17. Melting of the Primitive Mercurian Mantle, Insights into the Origin of Its Surface Composition

    Science.gov (United States)

    Boujibar, A.; Righter, K.; Rapp, J. F.; Ross, D. K.; Pando, K. M.; Danielson, L. R.; Fontaine, E.

    2016-01-01

    Recent findings of the MESSENGER mission on Mercury have brought new evidence for its reducing nature, widespread volcanism and surface compositional heteregeneity. MESSENGER also provided major elemental ratios of its surface that can be used to infer large-scale differentiation processes and the thermal history of the planet. Mercury is known as being very reduced, with very low Fe-content and high S and alkali contents on its surface. Its bulk composition is therefore likely close to EH enstatite chondrites. In order to elucidate the origin of the chemical diversity of Mercury's surface, we determined the melting properties of EH enstatite chondrites, at pressures between 1 bar and 3 GPa and oxygen fugacity of IW-3 to IW-5, using piston-cylinder experiments, combined with a previous study on EH4 melting at 1 bar. We found that the presence of Ca-rich sulfide melts induces significant decrease of Ca-content in silicate melts at low pressure and low degree of melting (F). Also at pressures lower than 3 GPa, the SiO2-content decreases with F, while it increases at 3 GPa. This is likely due to the chemical composition of the bulk silicate which has a (Mg+Fe+Ca)/Si ratio very close to 1 and to the change from incongruent to congruent melting of enstatite. We then tested whether the various chemical compositions of Mercury's surface can result from mixing between two melting products of EH chondrites. We found that the majority of the geochemical provinces of Mercury's surface can be explained by mixing of two melts, with the exception of the High-Al plains that require an Al-rich source. Our findings indicate that Mercury's surface could have been produced by polybaric melting of a relatively primitive mantle.

  18. Empirical constraints on partitioning of platinum group elements between Cr-spinel and primitive terrestrial magmas

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    Park, Jung-Woo; Kamenetsky, Vadim; Campbell, Ian; Park, Gyuseung; Hanski, Eero; Pushkarev, Evgeny

    2017-11-01

    Recent experimental studies and in situ LA-ICP-MS analysis on natural Cr-spinel have shown that Rh and IPGEs (Ir-group platinum group elements: Ru, Ir, Os) are enriched in the lattice of Cr-spinel. However, the factors controlling the partitioning behaviour of these elements are not well constrained. In this study, we report the Rh, IPGE, and trace element contents in primitive Cr-spinel, measured by LA-ICP-MS, from nine volcanic suites covering various tectonic settings including island arc picrites, boninites, large igneous province picrites and mid-ocean ridge basalts. The aim is to understand the factors controlling the enrichment of Rh and IPGEs in Cr-spinels, to estimate empirical partition coefficients between Cr-spinel and silicate melts, and to investigate the role of Cr-spinel fractional crystallization on the PGE geochemistry of primitive magmas during the early stages of fractional crystallization. There are systematic differences in trace elements, Rh and IPGEs in Cr-spinels from arc-related magmas (Arc Group Cr-spinel), intraplate magmas (Intraplate Group Cr-spinel), and mid-ocean ridge magmas (MORB Group Cr-spinel). Arc Group Cr-spinels are systematically enriched in Sc, Co and Mn and depleted in Ni compared to the MORB Group Cr-spinels. Intraplate Group Cr-spinels are distinguished from the Arc Group Cr-spinels by their high Ni contents. Both the Arc and Intraplate Group Cr-spinels have total Rh and IPGE contents of 22-689 ppb whereas the MORB Group Cr-spinels are depleted in Rh and IPGE (total time-resolved spectra of LA-ICP-MS data for Cr-spinels mostly show constant count rates for trace element and Rh and IPGEs, suggesting homogeneous distribution of these elements in Cr-spinels. The PGE spikes observed in several Cr-spinels were interpreted to be PGE-bearing mineral inclusions and excluded from calculating the PGE contents of the Cr-spinels. On primitive mantle normalized diagrams the Arc Group Cr-spinels are characterized by a fractionated

  19. Preferential uptake of ribose by primitive cells might explain why RNA was favored over its analogs

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    Pohorille, Andrew; Wei, Chenyu

    Permeation of molecules through membranes is a fundamental process in biological systems, which not only involves mass and signal transfers between the interior of a contemporary cell and its environment, but was also of crucial importance in the origin of life. In the absence of complex protein transporters, nutrients and building blocks of biopolymers must have been able to permeate membranes at sufficient rates to support primordial metabolism and cel-lular reproduction. From this perspective one class of solutes that is of special interest are monosaccharides, which serve not only as nutritional molecules but also as building blocks for information molecules. In particular, ribose is a part of the RNA backbone, but RNA analogs containing a number of other sugars have also been shown to form stable duplexes. Why, among these possibilities, ribose (and, subsequently, deoxyribose) was selected for the backbone of information polymers is still poorly understood. It was recently found that ribose permeates membranes an order of magnitude faster than its diastereomers, arabinose and xylose [1]. On this basis it was hypothesized that differences in membrane permeability to aldopentoses provide a mechanism for preferential delivery of ribose to primitive cells for subsequent, selective incorporation into nucleotides and their polymers. However, the origins of these unusually large differences had not been well understood. We addressed this issue in molecular dynamics simulations combined with free energy calculations. It was found that the free energy barrier for transferring ribose from water to the bilayer is lower by 1.5-2 kcal/mol than the barrier for transferring the other two aldopentoses. The calculated [2] and measured [1] permeability coefficients are in an excellent agreement. The sugar structures that permeate the membrane are -pyranoses, with a possible contribution of the -anomer for arabinose. The furanoid form of ribose is not substantially involved in

  20. Acumulação primitiva:  um processo atuante na sociedade contemporânea Accumulation Primitive: un processus actif dans la societé contemporaine Primitive accumulation: a process active in contemporary society

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    Sandra Lencioni

    2012-03-01

    acumulação primitiva e reprodução do capital na sociedade contemporânea.Dans le contexte d'hégémonie de la reproduction sociale capitaliste, l'accumulation primitive est interprétée soit comme un processus du passé, soit comme un processus qui se fait présent jusqu’aujourd’hui. Notre point de vue est que l'accumulacion primitive historique n'a pas disparu. Au contraire, elle est encore une importante composante de la société contemporaine. En ce cas, les deux processus capitalistes, d'accumulation primitive et de reproduction du capital, coexistent et s’accomplissent de façon contradictoire et dialectique. Le premier processus est attaché à la spoliation et à la production d'un capital nouveau, alors que le second est attaché à l'exploration d’un capital déjà constitué qui, en même temps, fait partie de celui là. La différence entre les deux termes, spoliation et exploration, est examinée dans la première partie du texte, et en considérant la position de Harvey à propos de cette controverse. Dans la deuxième partie on discute l'accumulation primitive qui se manifeste aujourd’hui, comme la fraude, le vol et la violence, tels qu’ils se présentaient lors de la genèse du capitalisme. Bien que le monde ait changé, à cause du progrès technique, et malgré l’existence de lois de protection des droits de l'homme, il y a encore des actions semblables à celles de cette époque là. Ces actions se manifestent vraiment comme expédientes de la production du capital à la façon primitive, à savoir: le vol de terres; la rapine des ressources naturelles y inclus la biopiraterie; l'esclavage pour dette, une forme violente de spoliation où le travailleur libre, par les mécanismes de domination auxquels il est soumis, perd sa liberté. Par conséquent, on propose la thèse suivante : toutes les formes de spoliation sont productrices d'argent et de capital en potentiel et le capital financier, à son tour,  construit particuli