Sample records for leite materno leite

  1. AN EMPIRICAL RESPONSE TO EXTERNAL WORLD SKEPTICISM Adam Leite (Indiana University, Bloomington)

    E-print Network

    Fitelson, Branden

    misleading inputs). 3. So, I don't know (reasonably or justifiably believe) anything about the world around1 AN EMPIRICAL RESPONSE TO EXTERNAL WORLD SKEPTICISM Adam Leite (Indiana University, Bloomington) Pacific APA, April 2009 Draft of March 1, 2009 My topic today is external world skepticism. More precisely

  2. Poetry Journal by Abdul Malik Leite Title of Journal: Beige is the Color I See

    E-print Network

    Bergman, Keren

    Poetry Journal by Abdul Malik Leite Title of Journal: Beige is the Color I See A note: This journal documents my time in Amman, Jordan with poetry. I wished to convey the emotional nature of my experiences, so my poems are largely confessional. Beige is the Color I See #12;Syrian Refugee *A poem

  3. Tracking soccer players using the graph representation Pascual Figueroa & Neucimar Leite

    E-print Network

    Cohen, Issac

    Tracking soccer players using the graph representation Pascual Figueroa & Neucimar Leite Institute. Introduction The movement of the soccer players on the field, as a function of time, is a useful information of the kinematical vari- ables of the soccer player movement, Erdman [5] filmed a soccer game with one stationary TV

  4. Adding Knowledge Updates to 3APL Vivek Nigam and Jo~ao Leite

    E-print Network

    Nigam, Vivek

    with a be- lief base containing the rule believe(santa claus) mother said(santa claus), and the fact mother said(santa claus). This agent can be seen as a child agent that believes in everything its mother says, in this case it believes in santa claus, because its mother said so (mother said(santa claus)). Furthermore

  5. Nexing Corpus: a corpus of verbal protocols on syllogistic reasoning Ant--nio Branco*, JosZ Leit

    E-print Network

    Branco, António Horta

    , 1700 Lisboa, Portugal {ahb,jsilva} University of Coimbra, Faculty of Psychology R. Col from Informatics, Applied Logic, Cognitive Psychology and Formal Linguistics in the areas of the syntax. In Section 3, the format used, both for the XML conformant structure of the documents and for the written

  6. Prof M. Leite,, 2123 CHE Building, 301-405-0231 Department of Materials Science and Engineering

    E-print Network

    Rubloff, Gary W.

    : The photovoltaic effect Schokley-Queisser limit, Photon in, electrons out Characteristics of a solar cell, figures Description: Overview of the fundamentals of photovoltaic devices, including principles of operation the fundamentals of photovoltaic devices including the different technologies available. Topics Covered

  7. [Self-medication behavior among pregnant women user of the Instituto Nacional Materno Perinatal, Peru 2011].


    Miní, Elsy; Varas, Rocio; Vicuña, Yuliana; Lévano, María; Rojas, Luis; Medina, Julio; Butron, Joece; Aranda, Renzo; Gutierrez, Ericson L


    We aim to determine the prevalence of self prescribing behaviour during pregnancy and its characteristics. For this purpose, we designed a cross sectional study and interviewed 400 pregnant women who had their prenatal care at Instituto Nacional Materno Perinatal, Lima. We found that 10.5% of the patients (42 patients) had a self prescribing behavior during pregnancy, 64.5% think that self prescribing behavior can produce congenital malformations. The medications used were classified as type A and B according to the Food and Drug Administration (FDA). Paracetamol was used more frequently (47.6%) followed by amoxicillin (16.7%). All the women who self-prescribed have had this behavior before pregnancy. According to these results, we conclude there is a low prevalence of self-prescribing behavior during pregnancy compared to the international literature. PMID:22858767

  8. Binding of visual features in human perception and memory 

    E-print Network

    Jaswal, Snehlata


    The leit motif of this thesis is that binding of visual features is a process that begins with input of stimulation and ends with the emergence of an object in working memory so that it can be further manipulated for ...

  9. Hercynitequartz-bearing granulites from Brejes Dome area, Jequi Block, Bahia, Brazil: Influence of charnockite intrusion on

    E-print Network

    Nicollet, Christian

    Leite c , Jean-Robert Kienast d , Reinhardt A. Fuck e , Eron Pires Macedo a a CPGG-Centro de Geologia e. Leite), (J.-R. Kienast), (R.A. Fuck), (E.P. Macedo), Madagascar (e.g. Nicollet, 1990), Algeria (e.g. Ouzegane and Boumaza, 1996), and Brazil (Moraes and Fuck

  10. MAC 0316/5754 --Conceitos de Linguagens de Programac~ao Primeiro Semestre de 2010

    E-print Network

    Reverbel, Francisco

    'jornal) > 2 (um jornal custa 2 reais) (preco 'duzia-de-bananas) > 4 (uma d´uzia de bananas custa 4 reais) Considere uma lista de compras com o seguinte formato: '([jornal 1] [duzia-de-bananas 3] [litro-de-leite 2 comprar um jornal, tr^es d´uzias de bananas, dois litros de leite, etc. (a) Escreva uma fun¸c~ao total

  11. 1H-NMR-Based Metabolic Profiling of Maternal and Umbilical Cord Blood Indicates Altered Materno-Foetal Nutrient Exchange in Preterm Infants

    PubMed Central

    Küster, Alice; Guignard, Nadia; Alexandre–Gouabau, Marie-Cécile; Darmaun, Dominique; Robins, Richard J.


    Background Adequate foetal growth is primarily determined by nutrient availability, which is dependent on placental nutrient transport and foetal metabolism. We have used 1H nuclear magnetic resonance (NMR) spectroscopy to probe the metabolic adaptations associated with premature birth. Methodology The metabolic profile in 1H NMR spectra of plasma taken immediately after birth from umbilical vein, umbilical artery and maternal blood were recorded for mothers delivering very-low-birth-weight (VLBW) or normo-ponderal full-term (FT) neonates. Principal Findings Clear distinctions between maternal and cord plasma of all samples were observed by principal component analysis (PCA). Levels of amino acids, glucose, and albumin-lysyl in cord plasma exceeded those in maternal plasma, whereas lipoproteins (notably low-density lipoprotein (LDL) and very low-density lipoprotein (VLDL) and lipid levels were lower in cord plasma from both VLBW and FT neonates. The metabolic signature of mothers delivering VLBW infants included decreased levels of acetate and increased levels of lipids, pyruvate, glutamine, valine and threonine. Decreased levels of lipoproteins glucose, pyruvate and albumin-lysyl and increased levels of glutamine were characteristic of cord blood (both arterial and venous) from VLBW infants, along with a decrease in levels of several amino acids in arterial cord blood. Conclusion These results show that, because of its characteristics and simple non-invasive mode of collection, cord plasma is particularly suited for metabolomic analysis even in VLBW infants and provides new insights into the materno-foetal nutrient exchange in preterm infants. PMID:22291897

  12. SIAM J. NUMER. ANAL. c 2005 Society for Industrial and Applied Mathematics Vol. 43, No. 2, pp. 767786

    E-print Network

    Leitão, Antonio

    SIAM J. NUMER. ANAL. c 2005 Society for Industrial and Applied Mathematics Vol. 43, No. 2, pp. 767, Federal University of St. Catarina, Brazil. 767 #12;768 F. FR¨UHAUF, O. SCHERZER, AND A. LEIT~AO With P

  13. BIODIVERSITY Potential impacts of oil and gas

    E-print Network

    Turner, Monica G.

    reindeer calving grounds across the Russian Arctic Tobias Kuemmerle1,2 *, Leonid Baskin3 , Pedro J. Leit, such as reindeer or caribou (Rangifer tarandus), which use only a small portion of their range at a given point others. Our aim was to identify potential calving ground habitat of wild tundra reindeer populations


    E-print Network

    Paraná, Universidade Federal do

    , chocolate, tradicional, cenoura, baunilha, banana, nega maluca). Lua de mel (coco) Bebidas (mín. 100 ml de) Bolo ou cuque sabor a escolher (laranja, fubá, coco, chocolate, tradicional, cenoura, baunilha, banana, nega maluca) Mini sonho sabor a escolher (doce de leite, chocolate, creme, goiabada). Bebidas (cada

  15. ACM SIGSOFT Software Engineering Notes vol 21 no 2 March 1996 Page 39 Working Results on Software

    E-print Network

    Leite, Julio Cesar Sampaio do Prado

    of casting the recovered design. We worked with two small systems and a complex one. Our objective here], [Leite 91]. [Klajman 92], [Prado 92]. Work has been cen- tered on methods and not much has been invested and casting them in JSD. JSD views software development as a forward engineer- ing activity, but we are using

  16. Max-Planck-Institut fur Mathematik

    E-print Network

    Max-Planck-Institut f¨ur Mathematik in den Naturwissenschaften Leipzig Domain Configurations Field L. D¨oring, E. Esselborn, S. Ferraz-Leite, F. Otto Max Planck Institute for Mathematics the International Max Planck Research School Mathematics in the Sciences. The research of the third author (SFL


    E-print Network

    CURSO DE PÓS-GRADUAÇÃO EM ENGENHARIA E TECNOLOGIA ESPACIAIS ÁREA DE CONCENTRAÇÃO EM MECÂNICA ESPACIAL E CONTROLE Coordenador Acadêmico do Curso Evandro Marconi Rocco Coordenador Acadêmico da Área de / USP, 2000. Waldemar de Castro Leite Filho, Doutor, UFRJ/COPPE, 1991. #12;2 CURSO DE ENGENHARIA E

  18. Accentuate Us! Kevin Scannell and Michael Schade

    E-print Network

    Scannell, Kevin Patrick

    .5 available in 68 languages (0.97%) Spellcheckers for 117 languages (1.67%) For this talk, we're looking fonts When electronic texts do exist, they are often entered as plain ASCII, either by transliteration be/al) Omitted diacritics matter! Leads to ambiguities, misunderstandings (leite vs. léite). #12

  19. Conservation economics. Comment on "Using ecological thresholds to evaluate the costs and benefits of set-asides in a biodiversity hotspot".


    Finney, Christopher


    Banks-Leite et al. (Reports, 29 August 2014, p. 1041) conclude that a large-scale program to restore the Brazilian Atlantic Forest using payments for environmental services (PES) is economically feasible. They do not analyze transaction costs, which are quantified infrequently and incompletely in the literature. Transaction costs can exceed 20% of total project costs and should be included in future research. PMID:25678654

  20. Thicket: Construc~ao e Manutenc~ao de Multiplas Arvores numa Rede entre Pares

    E-print Network

    Rodrigues, Luís E.T.

    Thicket: Constru¸c~ao e Manuten¸c~ao de M´ultiplas ´Arvores numa Rede entre Pares M´ario Ferreira, Jo~ao Leit~ao, and Lu´is Rodrigues INESC-ID / IST {mvvf, jleitao}, ler 2010 - II Simp´osio de Inform´atica, Lu´is S. Barbosa, Miguel P. Correia (eds), 9-10 Setembro, 2010, pp

  1. En qué está el teatro uruguayo

    E-print Network

    Pignataro Calero, Jorge


    Larreta, 1969) oAntígona (Mario Morgan, 1971); y en el más cercano, La ópera de dos centavos (Jorge Curi, 1998), Los asesinos (Ornar Grasso, 1999) o Una cita con Calígula (Roberto Suárez, 1999). 212 LATIN AMERICAN THEATRE REVIEW Entre ambos extremos se... Montevideo con recordados exponentes de la dramaturgia nacional de entonces y de comprobable vigencia aún hoy: Decir adiós de Alberto Paredes (1979), El herrero y la muerte de Mercedes Rein y Jorge Curi (1981) y Doña Ramona de Víctor Manuel Leites (1952...

  2. The morphometry of materno—fetal oxygen exchange barrier in a baboon model of obesity

    PubMed Central

    Samson, J.E.; Mari, G.; Dick, E.J.; Hubbard, G.B.; Ferry, R.J.; Schlabritz-Loutsevitch, N.E.


    Introduction More than one-fourth of U.S. women are overweight; more than one-third are obese. Maternal obesity has been linked to an increased incidence of stillbirths, fetal macrosomia, fetal intrauterine growth restriction and pre-eclampsia. The placenta plays a key role in the nutrients and oxygen supply to the fetus. The data about structural changes in the placental villous membrane (VM), a major component of the feto-maternal nutrient and oxygen exchange barrier, during obesity are sparse and inconsistent. Our objective was to evaluate the morphometric changes in the placental exchange barrier in a baboon model of obesity. Materials and methods The previously described baboon model of maternal obesity was studied. We compared 4 obese to 4 non-obese baboons. Placental stereology with the use of transmission electron microscopy was performed to estimate VM oxygen diffusing capacities and morphometry. Results The specific placental oxygen diffusing capacities per unit of fetal weight were similar in baboons and humans. Maternal leptin concentrations correlated negatively with placental basement membrane thickness (r = ?0.78, p < 0.05), while fetal leptin levels correlated negatively with endothelial thickness of fetal capillaries (r = ?0.78, p < 0.05). The total and specific villous membrane oxygen diffusing capacities were not different between the two groups. Conclusion To the best of our knowledge this is the first report of placental oxygen diffusing capacities and placental ultrastructural changes in a baboon model of obesity. Previously reported placental inflammation in maternal obesity is not associated with changes in the VM diffusing capacities and ultrastructure. PMID:21872927

  3. Materno-Fetal Transfer of Preproinsulin Through the Neonatal Fc Receptor Prevents Autoimmune Diabetes.


    Culina, Slobodan; Gupta, Nimesh; Boisgard, Raphael; Afonso, Georgia; Gagnerault, Marie-Claude; Dimitrov, Jordan; Østerbye, Thomas; Justesen, Sune; Luce, Sandrine; Attias, Mikhaël; Kyewski, Bruno; Buus, Søren; Wong, F Susan; Lacroix-Desmazes, Sebastien; Mallone, Roberto


    The first signs of autoimmune activation leading to ?-cell destruction in type 1 diabetes (T1D) appear during the first months of life. Thus, the perinatal period offers a suitable time window for disease prevention. Moreover, thymic selection of autoreactive T cells is most active during this period, providing a therapeutic opportunity not exploited to date. We therefore devised a strategy by which the T1D-triggering antigen preproinsulin fused with the immunoglobulin (Ig)G Fc fragment (PPI-Fc) is delivered to fetuses through the neonatal Fc receptor (FcRn) pathway, which physiologically transfers maternal IgGs through the placenta. PPI-Fc administered to pregnant PPIB15-23 T-cell receptor-transgenic mice efficiently accumulated in fetuses through the placental FcRn and protected them from subsequent diabetes development. Protection relied on ferrying of PPI-Fc to the thymus by migratory dendritic cells and resulted in a rise in thymic-derived CD4(+) regulatory T cells expressing transforming growth factor-? and in increased effector CD8(+) T cells displaying impaired cytotoxicity. Moreover, polyclonal splenocytes from nonobese diabetic (NOD) mice transplacentally treated with PPI-Fc were less diabetogenic upon transfer into NOD.scid recipients. Transplacental antigen vaccination provides a novel strategy for early T1D prevention and, further, is applicable to other immune-mediated conditions. PMID:25918233

  4. Corticosterone alters materno-fetal glucose partitioningand insulin signalling in pregnant mice

    E-print Network

    Vaughan, O. R.; Fisher, H. M.; Dionelis, K. N.; Jefferies, E. C.; Higgins, J. S.; Musial, B.; Sferruzzi-Perri, A. N.; Fowden, A. L.


    endocrine signals in the mouse placenta (Jones et al., 2013). However, post-transcriptional 473 mechanisms may also have a role in regulating placental nutrient transport when 474 glucocorticoids are raised. Certainly, adaptations in placental System A... ) were used to measure insulin (Crystal Chem Inc, Downers Grove, IL, USA) 206 and IGF-I (R&D Systems Europe Ltd, Abingdon, UK). In all cases, intra-assay coefficient of 207 variation was less than 7%. The limits of detection of the assays were 0.1 ng ml...

  5. Matrix De Rham Complex and Quantum A-infinity algebras

    NASA Astrophysics Data System (ADS)

    Barannikov, S.


    I establish the relation of the non-commutative BV-formalism with super-invariant matrix integration. In particular, the non-commutative BV-equation, defining the quantum A ?-algebras, introduced in Barannikov (Modular operads and non-commutative Batalin-Vilkovisky geometry. IMRN, vol. 2007, rnm075. Max Planck Institute for Mathematics 2006-48, 2007), is represented via de Rham differential acting on the supermatrix spaces related with Bernstein-Leites simple associative algebras with odd trace q( N), and gl( N| N). I also show that the matrix Lagrangians from Barannikov (Noncommutative Batalin-Vilkovisky geometry and matrix integrals. Isaac Newton Institute for Mathematical Sciences, Cambridge University, 2006) are represented by equivariantly closed differential forms.

  6. Effects of gestational age and surface modification on materno-fetal transfer of nanoparticles in murine pregnancy

    NASA Astrophysics Data System (ADS)

    Yang, Hui; Sun, Cuiji; Fan, Zhenlin; Tian, Xin; Yan, Liang; Du, Libo; Liu, Yang; Chen, Chunying; Liang, Xing-Jie; Anderson, Gregory J.; Keelan, Jeffrey A.; Zhao, Yuliang; Nie, Guangjun


    Nanoparticle exposure in pregnancy may result in placental damage and fetotoxicity; however, the factors that determine fetal nanoparticle exposure are unclear. Here we have assessed the effect of gestational age and nanoparticle composition on fetal accumulation of maternally-administered nanomaterials in mice. We determined the placental and fetal uptake of 13 nm gold nanoparticles with different surface modifications (ferritin, PEG and citrate) following intravenous administration at E5.5-15.5. We showed that prior to E11.5, all tested nanoparticles could be visualized and detected in fetal tissues in significant amounts; however, fetal gold levels declined dramatically post-E11.5. In contrast, Au-nanoparticle accumulation in the extraembryonic tissues (EET) increased 6-15 fold with gestational age. Fetal and EET accumulation of ferritin- and PEG-modified nanoparticles was considerably greater than citrate-capped nanoparticles. No signs of toxicity were observed. Fetal exposure to nanoparticles in murine pregnancy is, therefore, influenced by both stage of embryonic/placental maturation and nanoparticle surface composition.

  7. Evidence for elemental variation in the ejecta of the Tycho supernova remnant

    NASA Technical Reports Server (NTRS)

    Vancura, O.; Gorenstein, P.; Hughes, John P.


    We present an X-ray study of the Tycho supernova remnant utilizing archival data from the high-resolution imagers (HRIs) on Einstein and ROSAT, the low-energy imaging telescopes (LEITs) on EXOSAT, and spectral data from the Broad Band X-ray Telescope (BBXRT). We have made use of the differing HRI bandpasses to construct images of Tycho in two spectral bands, o.7-1.8 keV and 1.8-4.5 keV. We find that the two images differ, with the harder image showing enhanced emission along much of the south, west, and north periphery. There appears to be enhanced soft emission in the interior and in one particular knot of emission in the southeast. Besides continuum (which we model here as thermal bremsstrahlung emission), we believe the hard image shows primarily the distribution of high-ionization Si and S K-shell lines which lie in the 1.8-2.6 keV band, while the softer image has contributions from Si as well as Fe XVII to Fe XXIV L-shell lines in the 0.7-1.4 keV band. Guided by the results of nonequilibrium ionization modeling of the BBXRT spectral data, we interpret the observed contrast in hard and soft X-ray emission in terms of variations in abundance, ionization timescale, and temperature. The most likely explanation for the spectral differences are spatial variations of the relative abundances of Si, S, and Fe.

  8. Action prediction modulates both neurophysiological and psychophysical indices of sensory attenuation

    PubMed Central

    Roussel, Cedric; Hughes, Gethin; Waszak, Florian


    Sensory attenuation refers to the observation that stimuli that are predicted based on one’s action are attenuated. This phenomenon has primarily been observed as a neurophysiological phenomenon, with reduced Event-Related Potential (ERP) (e.g., Bäss et al., 2008) and BOLD (e.g., Blakemore et al., 1998). However, psychophysical investigations (e.g., Sato, 2008; Cardoso-Leite et al., 2010; Roussel et al., 2013) have confirmed that action prediction also influences the perception of sensory action effects. The present study recorded both neurophysiological and psychophysical measures in a single experiment, to confirm whether the two phenomena are related. In addition, by measuring the ERP modulations of both stimulus contrast and prediction congruency, we sought to directly relate the neurophysiological phenomenon to the magnitude of sensory processing in the brain. Participants performed left- and right-hand voluntary actions that were previously associated with the letters A and H. In the test phase, participants were presented with these same two letters, at one of two possible contrasts. Participants were required to report which of the two possible contrasts had been presented. We observed both reduced contrast discrimination (in line with Roussel et al., 2013) and a reduced ERP response for congruent action-effects. Furthermore, our congruency modulation was observed on the same component that differed as a function of stimulus contrast. Taken together these results strongly suggest that neurophysiological indices of sensory attenuation reflect reduced sensory processing of voluntary action effects. PMID:24616691

  9. Cytokine gene expression at the materno-foetal interface after experimental Neospora caninum infection of heifers at 110 days of gestation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Neospora caninum is a major cause of abortion in cattle but the reasons why some animals abort and not others remain unclear. The immunological control of the parasite in the placenta or by the foetus could be the key to determining the mechanism of abortion and/or transplacental transmission to the...

  10. Spatio-temporal clustering of wildfires in Portugal

    NASA Astrophysics Data System (ADS)

    Costa, R.; Pereira, M. G.; Caramelo, L.; Vega Orozco, C.; Kanevski, M.


    Several studies have shown that wildfires in Portugal presenthigh temporal as well as high spatial variability (Pereira et al., 2005, 2011). The identification and characterization of spatio-temporal clusters contributes to a comprehensivecharacterization of the fire regime and to improve the efficiency of fire prevention and combat activities. The main goalsin this studyare: (i) to detect the spatio-temporal clusters of burned area; and, (ii) to characterize these clusters along with the role of human and environmental factors. The data were supplied by the National Forest Authority(AFN, 2011) and comprises: (a)the Portuguese Rural Fire Database, PRFD, (Pereira et al., 2011) for the 1980-2007period; and, (b) the national mapping burned areas between 1990 and 2009. In this work, in order to complement the more common cluster analysis algorithms, an alternative approach based onscan statistics and on the permutation modelwas used. This statistical methodallows the detection of local excess events and to test if such an excess can reasonably have occurred by chance.Results obtained for different simulations performed for different spatial and temporal windows are presented, compared and interpreted.The influence of several fire factors such as (climate, vegetation type, etc.) is also assessed. Pereira, M.G., Trigo, R.M., DaCamara, C.C., Pereira, J.M.C., Leite, S.M., 2005:"Synoptic patterns associated with large summer forest fires in Portugal".Agricultural and Forest Meteorology. 129, 11-25. Pereira, M. G., Malamud, B. D., Trigo, R. M., and Alves, P. I.: The history and characteristics of the 1980-2005 Portuguese rural fire database, Nat. Hazards Earth Syst. Sci., 11, 3343-3358, doi:10.5194/nhess-11-3343-2011, 2011 AFN, 2011: AutoridadeFlorestalNacional (National Forest Authority). Available at

  11. Multivariate statistical analysis of wildfires in Portugal

    NASA Astrophysics Data System (ADS)

    Costa, Ricardo; Caramelo, Liliana; Pereira, Mário


    Several studies demonstrate that wildfires in Portugal present high temporal and spatial variability as well as cluster behavior (Pereira et al., 2005, 2011). This study aims to contribute to the characterization of the fire regime in Portugal with the multivariate statistical analysis of the time series of number of fires and area burned in Portugal during the 1980 - 2009 period. The data used in the analysis is an extended version of the Rural Fire Portuguese Database (PRFD) (Pereira et al, 2011), provided by the National Forest Authority (Autoridade Florestal Nacional, AFN), the Portuguese Forest Service, which includes information for more than 500,000 fire records. There are many multiple advanced techniques for examining the relationships among multiple time series at the same time (e.g., canonical correlation analysis, principal components analysis, factor analysis, path analysis, multiple analyses of variance, clustering systems). This study compares and discusses the results obtained with these different techniques. Pereira, M.G., Trigo, R.M., DaCamara, C.C., Pereira, J.M.C., Leite, S.M., 2005: "Synoptic patterns associated with large summer forest fires in Portugal". Agricultural and Forest Meteorology. 129, 11-25. Pereira, M. G., Malamud, B. D., Trigo, R. M., and Alves, P. I.: The history and characteristics of the 1980-2005 Portuguese rural fire database, Nat. Hazards Earth Syst. Sci., 11, 3343-3358, doi:10.5194/nhess-11-3343-2011, 2011 This work is supported by European Union Funds (FEDER/COMPETE - Operational Competitiveness Programme) and by national funds (FCT - Portuguese Foundation for Science and Technology) under the project FCOMP-01-0124-FEDER-022692, the project FLAIR (PTDC/AAC-AMB/104702/2008) and the EU 7th Framework Program through FUME (contract number 243888).

  12. The management of turn transition in signed interaction through the lens of overlaps

    PubMed Central

    Girard-Groeber, Simone


    There have been relatively few studies on sign language interaction carried out within the framework of conversation analysis (CA). Therefore, questions remain open about how the basic building blocks of social interaction such as turn, turn construction unit (TCU) and turn transition relevance place (TRP) can be understood and analyzed in sign language interaction. Recent studies have shown that signers regularly fine-tune their turn-beginnings to potential completion points of turns (Groeber, 2014; Groeber and Pochon-Berger, 2014; De Vos et al., 2015). Moreover, signers deploy practices for overlap resolution as in spoken interaction (McCleary and Leite, 2013). While these studies have highlighted the signers' orientation to the “one-at-a-time” principle described by Sacks et al. (1974), the present article adds to this line of research by investigating in more detail those sequential environments where overlaps occur. The contribution provides an overview of different types of overlap with a focus of the overlap's onset with regard to a current signer's turn. On the basis of a 33-min video-recording of a multi-party interaction between 4 female signers in Swiss German Sign Language (DSGS), the paper provides evidence for the orderliness of overlapping signing. Furthermore, the contribution demonstrates how participants collaborate in the situated construction of turns as a dynamic and emergent gestalt and how they interactionally achieve turn transition. Thereby the study adds to recent research in spoken and in signed interaction that proposes to rethink turn boundaries and turn transition as flexible and interactionally achieved. PMID:26150792

  13. A novel method for mapping open-circuit voltage in solar cells with nanoscale resolution (Presentation Recording)

    NASA Astrophysics Data System (ADS)

    Tennyson, Elizabeth; Garrett, Joseph; Frantz, Jesse A.; Myers, Jason D.; Bekele, Robel Y.; Sanghera, Jasbinder S.; Munday, Jeremy N.; Leite, Marina S.


    The electrical characteristics of thin-film compound semiconductor solar cells have been successfully probed by scanning probe microscopy. Nevertheless, a direct relationship between the measured signals and the figures of merit that define the device performance is still missing. Here we present a novel method to image and spatially resolve the Voc of solar cells with truly nanoscale resolution (<100 nm), based on a variant of illuminated Kelvin probe force microscopy (KPFM) [1]. We map the Voc by measuring the difference between the contact potential difference under illumination and in the dark, which is equal to the photo-generated voltage of the device (and is proportional to the Fermi level splitting). We complement our new metrology by applying scanning photocurrent microscopy using near-field scanning microscopy (NSOM) probes as a local source of excitation to image local variations in Jsc within the material, also with nanoscale resolution. Further, we spatially and spectrally resolve the external quantum efficiency (EQE) within the devices, also with nanoscale resolution, while mimicking the power density operation conditions of real devices [2]. Combined, these new tools provide a complete picture of the local optoelectric characteristics of PV devices, including an indirect measurement of the centers for non-radiative recombination, and a direct mapping of the local collection properties of the material, respectively. We apply our novel metrology to polycrystalline solar cells, where we find Voc local variations of >200 mV. [1] E.M. Tennyson et al., Nature Commun., in review; [2] M.S. Leite et al., ACS Nano. 11, 11883 (2014).

  14. A Mathematical Physicist's Approach to Virology

    NASA Astrophysics Data System (ADS)

    Twarock, Reidun


    The following talk has been given in a special session dedicated to Professor Heinz-Dietrich Doebner at QTS in Prague in August 2011 on the occasion of his 80th birthday. It documents my journey from being a PhD student in Mathematical Physics at the Arnold Sommerfeld Institute in Clausthal under his supervision, to becoming a Professor of Mathematical Biology at the University of York in the UK. I am currently heading an interdisciplinary research group of eight PDRAs and PhDs, focussed on investigating the structures of viruses from a symmetry perspective and unravelling the implications of virus structure on how viruses form and infect their hosts. A central element in my research is my fascination with the development and application of symmetry techniques, which stems from my time in Clausthal when working with Professor Doebner and colleagues. I would like to thank Professor Doebner for these important formative years in Clausthal. Der folgende Vortrag war mein Beitrag zu einer Festsitzung fuer Herrn Professor Heinz-Dietrich Doebner auf der Tagung QTS im August 2011 anläßlich seines achzigsten Geburtstags. Dieser Beitrag dokumentiert, wie sich meine Forschungen aus der Zeit als Doktorandin von Herrn Professor Doebner in Mathematischer Physik am Arnold Sommerfeld Institut in Clausthal weiterentwickelt haben, und zu meiner Professur in Mathematischer Biologie an der Universität York geführt haben. Ich leite dort zur Zeit eine interdisziplinäre Forschungsgruppe von acht Postdocs und Doktoranden, die sich mit der Entwicklung und Anwendung von Symmetrie-Techniken in der Virologie beschäftigt, und insbesondere untersucht, wie sich die Symmetrie-Eigenschaften von Viren auf deren Entstehung und Funktionsweise auswirken. Eine wichtige Vorraussetzung für dieses Forschungsprogramm ist meine Faszination für die Modellierung von Symmetrie-Eigenschaften, die ich während meiner Zusammenarbeit mit Herrn Professor Doebner und Kollegen in Clausthal entwickelt habe. Ich möchte Herrn Professor Doebner für diese wichtigen formativen Jahre besonderen Dank aussprechen.


    E-print Network

    de investigación: Salud, nutrición y comportamiento de los grupos materno-infantil y de preescolares (1992) UNAM. Temas de investigación: Medicina tradicional. Estado nutricional. Geografía de la salud

  16. Deforestation in Brazil: motivations, journeys and tendencies

    NASA Astrophysics Data System (ADS)

    Leite, J. C.; Ferreira, A. J. D.; Esteves, T. C. J.; Bento, C. P. M.


    José Carlos Leite1; António José Dinis Ferreira2; Tanya Cristina de Jesus Esteves2; Célia Patrícia Martins Bento2 1Universidade Federal de Mato Grosso, Brazil; 2IPC - Escola Superior Agrária de Coimbra, Portugal Over the last three decades, deforestation in Brazil occurred systematically in the area known as the "arc of deforestation", an extensive geographical area located in the interface of the Cerrado and the Amazon biomes. This work encompasses the reasons, causes and/or motivations of that recent deforestation, focusing on the Central-West and Northern regions. A number of reasons will be presented, seeking to build an approach able to identify the deepest roots of deforestation of those regions. Our actions over the environment are framed by our cultural matrix that stream from a western philosophic attitude. This way, to understand the framework where the deforestation actions are justified requires a multidisciplinary approach to understand the deforestation of the Cerrado and Amazon biomes, since the motivations for forest destruction in Brazil are complex and not entirely understood within the domains of a single disciplinary area. To search for an isolated cause to understand the recent deforestation can only be plausible if we ignore information on what actually happens. The methodology used in this work is based on a bibliographical revision, analysis of georeferrenced information, participative processes implementation and observation of stakeholder behavior, and field research. It departs from a general vision on deforestation that initially occurred at the littoral region, by the Atlantic Rainforest, right after the arrival of the Europeans, and throughout the centuries penetrates towards the interior, hitting the Cerrado and Amazon biomes. In this last case, we focused on the Vale do Alto Guaporé region, near Bolivia, where the intensity of the deforestation was verified from 1970 to 1990. Ultimately, the final result is a mosaic of reasons for deforestation - that has been done by both large and small land owners - that incorporates other views that have been absent in the explanations given by so-called specialized literature of Brazil's deforestation.

  17. Greenhouse gas emissions in the Brazilian semiarid region: environmental, climate and social constraints

    NASA Astrophysics Data System (ADS)

    Sousa-Neto, Eráclito; Ometto, Jean


    The process of removing a forest to open new agricultural lands, which has been very intensive in developing countries like Brazil during the last decades (Lapola et al, 2014), contributes to about 12% of the global anthropogenic emissions (Le Quéré et al., 2009). Forest cover removal releases carbon dioxide (CO2) and other greenhouse gases (GEE) like methane (CH4) and nitrous oxide (N2O), as a result of burning trees, followed by gradual decomposition of the forest biomass left on the ground while pasture or crop plantations are being established (Ramankutty et al., 2007). In Brazil, the 2nd Brazilian National Communication to the United Nations Framework Convention on Climate Change (UNFCCC), presents the mean annual net CO2 emissions caused by changes in land use in each Brazilian biome and the first place in the ranking is occupied by the Amazon Rainforest Biome (860,874 Gg), followed by Savannah (302,715 Gg), Atlantic Forest (79,109 Gg), Caatinga (37,628 Gg), Pantanal (16,172 Gg) and Pampa (-102 Gg) (MCT 2010). Despite these results, the estimates of CO2 emissions caused by land use changes in the Brazilian semiarid region (Caatinga) are very limited and scarce, and associated to uncertainties which are directly related to the estimated biomass in different types of vegetation which are spatially distributed within the biome, as well as the correct representation of the dynamics of the deforestation process itself, and the more accurate mapping use and land cover. Based on such facts, this project is estimating the emissions of the main greenhouse gases (CO2, N2O and CH4) caused by land use changes in an area of Caatinga biome in Pernambuco State through the model INPE-EM. So far, it is known that from decades of 1940 up to 1995, Caatinga biome has contributed with about 3.2 % to total land use change emissions in the country (Leite et al, 2012), and recently (1990-2005), the contributions of Caatinga are even higher (over 30%), according to the 2nd Brazilian National Communication (2010). By means means of the model INPE-EM (data still being acquired), we are trying to diminish the uncertainties and identify specific and integrated emissions of GHG, as well as the stocks and flows of C and N, in order to contribute to the current information about GEE dynamic in the Brazilian Northeast and also to enhance the Brazilian GHG inventory. Besides, the model will incorporate the temporal dynamics related to the deforestation process, and accounts for the biophysical and socioeconomic heterogeneity of the region in study.


    E-print Network

    ) UNAM. Temas de investigación: Medicina tradicional. Estado nutricional. Geografía de la salud. gbalam. Temas de investigación: Salud, nutrición y comportamiento de los grupos materno-infantil y de preescolar


    E-print Network

    : Salud, nutrición y comportamiento materno-infantil y preescolar en relación al entorno ecológico. Perfil relación con procesos socioambientales. Desarrollo de un sistema de información geográfica en salud. lola

  20. Modelling wildfire activity in Iberia with different Atmospheric Circulation WTs

    NASA Astrophysics Data System (ADS)

    Sousa, P. M.; Trigo, R.; Pereira, M. G.; Rasilla, D.; Gouveia, C.


    This work focuses on the spatial and temporal variability of burnt area (BA) for the entire Iberian Peninsula (IP) and on the construction of statistical models to reproduce the inter-annual variability, based on Weather Types Classification (WTC). A common BA dataset was assembled for the first time for the entire Iberian Peninsula, by merging BA records for the 66 administrative regions of Portugal and Spain. A normalization procedure was then applied to the various size regions before performing a k-means cluster analysis to identify large areas characterized by similar fire regimes. The most compelling results were obtained for 4 clusters (Northwestern, Northern, Southwestern and Eastern) whose spatial patterns and seasonal fire regimes are shown to be related with constraining factors such as topography, vegetation cover and climate conditions. The response of fire burnt surface at monthly time scales to both long-term climatic pre-conditions and short-term synoptic forcing was assessed through correlation and regression analysis using: (i) temperature and precipitation from 2 to 7 months in advance to fire peak season; (ii) synoptic weather patterns derived from 11 distinct classifications derived under the COSTaction-733. Different responses were obtained for each of the considered regions: (i) a relevant link between BA and short-term synoptic forcing (represented by monthly frequencies of WTC) was identified for all clusters; (ii) long-term climatic preconditioning was relevant for all but one cluster (Northern). Taking into account these links, we developed stepwise regression models with the aim of reproducing the observed BA series (i.e. in hindcast mode). These models were based on the best climatic and synoptic circulation predictors identified previously. All models were cross-validated and their performance varies between clusters, though models exclusively based on WTCs tend to better reproduce annual BA time series than those only based on pre-conditioning climatic information. Nevertheless, the best results are attained when both synoptic and climatic predictors are used simultaneously as predictors, in particular for the two western clusters, where correlation coefficient values are higher than 0.7. Finally, we have used WTC composite maps to characterize the typical synoptic configurations that favor high values of BA. These patterns correspond to dry and warm fluxes, associated with anticyclonic regimes, which foster fire ignition (Pereira et al., 2005). Pereira, M.G., Trigo, R.M., DaCamara, C.C., Pereira, J.M.C., Leite, S.M., 2005: "Synoptic patterns associated with large summer forest fires in Portugal". Agricultural and Forest Meteorology. 129, 11-25. COST733, 2011: "COST 733 Wiki - Harmonisation and Applications of Weather Type Classifications for European regions or COST733 spatial domains for Europe". Available at [accessed 1 September 2011].

  1. Assessing fire risk in Portugal during the summer fire season

    NASA Astrophysics Data System (ADS)

    Dacamara, C. C.; Pereira, M. G.; Trigo, R. M.


    Since 1998, Instituto de Meteorologia, the Portuguese Weather Service has relied on the Canadian Fire Weather Index (FWI) System (van Wagner, 1987) to produce daily forecasts of fire risk. The FWI System consists of six components that account for the effects of fuel moisture and wind on fire behavior. The first three components, i.e. the Fine Fuel Moisture Code (FFMC), the Duff Moisture Code (DMC) and the Drought Code (DC) respectively rate the average moisture content of surface litter, decomposing litter, and organic (humus) layers of the soil. Wind effects are then added to FFMC leading to the Initial Spread Index (ISI) that rates fire spread. The remaining two fuel moisture codes (DMC and DC) are in turn combined to produce the Buildup Index (BUI) that is a rating of the total amount of fuel available for combustion. BUI is finally combined with ISI to produce the Fire Weather Index (FWI) that represents the rate of fire intensity. Classes of fire danger and levels of preparedness are commonly defined on an empirical way for a given region by calibrating the FWI System against wildfire activity as defined by the recorded number of events and by the observed burned area over a given period of time (Bovio and Camia, 1998). It is also a well established fact that distributions of burned areas are heavily skewed to the right and tend to follow distributions of the exponential-type (Cumming, 2001). Based on the described context, a new procedure is presented for calibrating the FWI System during the summer fire season in Portugal. Two datasets were used covering a 28-year period (1980-2007); i) the official Portuguese wildfire database which contains detailed information on fire events occurred in the 18 districts of Continental Portugal and ii) daily values of the six components of the FWI System as derived from reanalyses (Uppala et al., 2005) of the European Centre for Medium-Range Weather Forecasts (ECMWF). Calibration of the FWI System is then performed in two steps; 1) a truncated Weibull distribution is fitted to the sample of burned areas and 2) the quality of the fitted statistical model is improved by incorporating components of the FWI System as covariates. Obtained model allows estimating on a daily basis the probability of occurrence of fires larger than a given threshold as well as producing maps of fire risk. Results as obtained from a prototype currently being developed will be presented and discussed. In particular, it will be shown that results provide additional evidence of the known fact that the extent of burned area in Portugal is controlled by two main atmospheric factors (Pereira et al. 2005): i) a long-term control related to the regime of temperature and precipitation in spring and ii) a short-term control exerted by the occurrence of very intense dry spells in days of extreme synoptic situations. Bovio, G., and A. Camia. 1998. An analysis of large forest fire danger conditions in Europe. In Proc. 3rd Int. Conf. on Forest Fire Research & 14th Conf. on Fire and Forest Meteorology, Viegas, D.X. (Ed.), Luso, 16-20 Nov., ADAI, 975-994. Cumming, S.G., 2001. Parametric models of the fire size distribution. Can J. For. Res., 31, 1297-1303. Pereira, M.G., Trigo, R.M., DaCamara, C.C., Pereira, J.M.C. and Leite, S.M., 2005. Synoptic patterns associated with large summer forest fires in Portugal. Agr. and For. Meteorol., 129 (1-2), 11-25. Uppala, S.M. et al., 2005: The ERA-40 re-analysis. Quart. J. R. Meteorol. Soc., 131, 2961-3012. Van Wagner, C.E., 1987. Development and structure of the Canadian forest fire weather index system. Canadian Forestry Service, Forest Technical Report 35, Ottawa, 37 pp.

  2. PREFACE: Introduction to the proceedings of Dynamics Days South America 2010

    NASA Astrophysics Data System (ADS)

    Macau, Elbert E. N.; Pereira, Tiago; Prado, Antonio F. B. A.; Turci, Luiz F. R.; Winter, Othon C.


    This proceedings presents selected contributions from the participants of South America Dynamics Days 2011, which was hosted by the National Institute for Space Research (INPE), Brazil, in July 2010. Dynamics Days was founded in 1980 and is the longest standing and most respected international series of meetings devoted to the field of dynamics and nonlinearity. Traditionally it has brought together researchers from a wide range of backgrounds - including physics, biology, engineering, chemistry and mathematics - for interdisciplinary research into nonlinear science. Dynamics Days South America 2010 marked the beginning of the South American branch of Dynamics Days. It brought together, for the first time in South America, researchers from a wide range of backgrounds who share a common interest in the theory and applications of nonlinear dynamics. Thus, South American researchers had a forum to promote regional as well as international scientific and technological exchange and collaboration especially, but not exclusively, on problems that are particularly relevant for the development of science and technology in the South American region. Furthermore, the conference also brought together prominent scientists from around the world to review recent developments in nonlinear science. This conference comprised plenary invited talks, minisymposia, contributed talks and poster sessions. The articles that are compiled here were chosen from among the works that were presented as contributed talks and posters. They represent a good selection which allows one to put issues that were discussed during the conference into perspective. It is possible to evaluate the success of an initiative by using several indices. In relation to attendees, the conference had 311 participants from 22 countries, who presented 341 works. About 86% of the participants came from South American countries. These figures allow one to classify this Dynamics Days conference as that with the greatest number of attendees ever. Finally, we would like to express our gratitude to all the participants for their presentations, discussions, and remarkable interactions with one another. The tireless work undertaken by all the members of the International Advisory Committee and the Organizing Committee must also be recognized. We also wish to express our deep appreciation for the Scientific Societies and Research Support Agencies which supported the conference and provided all the resources which were necessary to make this idea of a South American Dynamics Days come true. Elbert E N Macau, Tiago Pereira, Antonio F B A Prado, Luiz F R Turci, and Othon C WinterEditors Conference photograph Conference photograph Conference photograph Conference photograph International Advisory Committee Adilson E MotterNorthwestern UniversityEvanston - IL - USA Alfredo OzorioCentro Brasileiro de Pesquisas FísicasRio de Janeiro - RJ - Brazil Celso Grebogi (Chair)University of AberdeenAberdeen - UK Ed OttUniversity of MarylandCollege Park - MD - USA Epaminondas Rosa JrIllinois State UniversityNormal - IL - USA Hans Ingo WeberPontifícia Universidade CatólicaRio de Janeiro - RJ - Brazil Holger KantzMax Planck Institute for the Physics of Complex SystemsDresden - Germany Jason Gallas (Co-chair)Universidade Federal do Rio Grande do SulPorto Alegre - RS - Brazil José Roberto Rios LeiteUniv. Federal de PernanbucoRecife - PE - Brazil Jürgen KurthsPotsdam Institute for climate Impact ResearchHumboldt University, Berlin - Germany Kenneth ShowalterWest Virginia UniversityMorgantown - WV - USA Lou PecoraNaval Research LabWashington - DC - USA Luis Antonio AguirreUniversidade Federal de Minas GeraisBelo Horizonte - MG - Brazil Marcelo VianaIMPA - Instituto Nacional de Matemática Pura e AplicadaRio de Janeiro - RJ - Brazil Miguel A F SanjuánUniversidad Rey Juan CarlosMadrid - Spain Paulo Roberto de Souza MendesPontifícia Universidade CatólicaRio de Janeiro - RJ - Brazil Roland KorbeleUniversidade de São PauloSão Carlos - SP - Brazil Rubens SampaioPontifícia Universidade CatólicaRio de Ja

  3. Preface

    NASA Astrophysics Data System (ADS)

    Vargas, Helion


    The biennial International Conferences on Photoacoustic and Photothermal Phenomena (ICPPP) are widely recognized as the major venue for the dissemination of recent and significant research results in the traditional areas, as well as in new and exciting outgrowths of this interdisciplinary field. The ICPPP is concerned with the science, applications and technologies involving the optical, electron-beam or otherwise production, propagation and detection of acoustic, thermal and general diffusion-wave fields.

    In the 2004 edition the conference was held in Rio de Janeiro, Brazil, and involved 14 topics covered in the scientific programme. These are Spectroscopy, Analytical Chemistry and Photochemistry, PA and PT Imaging and Microscopy, Thermophysical Properties and Characterization of Materials, Laser Ultrasonics, Ultrafast PA and PT Phenomena, Electronic and Optical Materials, Thin Films and Devices, Non Linear Phenomena and Inverse Problem, Nanoscale Phenomena, Non Destructive Evaluation, Diffusion Waves and Applications, Industrial Applications, New Instruments and Methodology, Biological,Medical and Dental Applications, Agriculture, Food and Environmental Applications . More than 300 short abstracts contributions were received and refereed for acceptation, from 690 authors of 28 different countries.

    This volume contains the proceedings of the 13ICPPP including the 207 full papers accepted after a very careful peer review process. Their contents are very deep and modern and show the peculiar interdisciplinary nature of the area. It is provided a collection of papers which includes the traditional subjects of the area as well as new developments of th the fields. The characterization of materials is occupying a great interest in the papers and many studies involving nanoscale phenomena were developed exploring the photothermal methodology. As in the previous conferences thermal wave microscopy and non-linear photothermal phenomena keep a high interest. The application of the methodology to any diffusive wave, other than the thermal one, showed significant growth. In the applications field many expressive papers are analyzing environmental, dental and medical concerns besides those involving other industrial purposes.

    The Conference received financial support from various Brazilian institutions and agencies, specially the National Council for Scientific and Technological Development - CNPq and Research and Projects Financing - Brazilian innovation Agency - FINEP, and from United Nations Educational, Scientific and Cultural Organization - UNESCO, to whom the conference organizers are very grateful.

    We would like to thank greatly the colleagues that helped much with the refereeing tasks and for the stimulating discussions and suggestions during the conference organization and proceedings preparation. Besides we wish to thank the authors for the high quality of their contributions. In special it should be acknowledge the essential help of the people from State University of the North of Rio de Janeiro (Fluminense)- UENF, State University of Campinas - UNICAMP and National Institute for Space Research - INPE, and colleagues that chaired previous conferences. Finally, we are all grateful evious for the precious work of the conference secretary Nelia F. Leite.

    Helion Vargas Chairman of the 13th International Conference on Photoacoustic and Photothermal Phenomena

  4. Position and Velocity Tracking in Cellular Networks Using the Kalman Filter

    SciTech Connect

    Olama, Mohammed M; Djouadi, Seddik M; Kuruganti, Phani Teja


    Access to the right information anytime, anywhere is becoming the new driving force for the information technology revolution. The 'right' information's relevance is based on the user's profile and his/her current geographical position and/or time. Location Based Service (LBS) is an innovative technology that provides information or makes information available based on the geographical location of the mobile user. Analysts predict that LBSs will lead to new applications, generating billions of US dollars worldwide (Leite, 2001; Searle, 2001). The need for an efficient and accurate mobile station (MS) positioning system is growing day by day. The ability to pinpoint the location of an individual has an obvious and vital value in the context of emergency services (Chan, 2003; Olama et al., 2008). Pinpointing the location of people and other valuable assets also opens the door to a new world of previously unimagined information services and m-commerce probabilities. For example, availability of services like 'Where is the nearest ATM?', 'Check traffic conditions on the highway on my route', 'Find a parking lot nearby', as well as answers to 'Where is my advisor?', and 'Where is my car?' will be an everyday rule in our lives (Charalambous & Panayiotou, 2004). A technology independent LBS architecture can be considered as comprised by three main parts (Girodon, 2002): A user requesting information, a mobile network operator and its partners, and several content providers (e.g. data, maps). The subscriber requests a personalized service dependant on his geographic location. The system will ask the Location Services Manager (which is in charge of handling requests, i.e., send/receive to the Location Calculator and the Content Providers) to pinpoint the location of the mobile. The Location Services Manager (LSM), using the Location Calculator, will ask the Content Provider (CP) to supply qualified information according to the mobile's geographical position. The LSM will eventually receive the answer from the CP and send it to the mobile, performing the essential data translations. Fig. 1 outlines the precedent concept. For effective provision of LBS, one has to provide an accurate location, as well as suitable information for users required by the corresponding service, with minimal expenditure. Thus, there are three main technology issues that have to be resolved for LBS: positioning technology, application technology, and location services (Dru & Saada, 2001). A very important technology is of course the positioning technology, the way to find out the location of a mobile device accurately. Due to the unique characteristics of the cellular environment, it is a great challenge to locate the user precisely. However, in many cases, application technology and location services are important consideration of LBS. Application technology manages the geographic information and delivers the customer requests to the appropriate service provider, thus it constitutes the communication system involved. LBS uses the geographic information to provide geographically sensitive information and services. Location-based applications and services are not sensitive to the type of location technology that is used - they merely rely on reasonably accurate geographic coordinates (Chan, 2003). This chapter is structured as follows: In Section 2, we describe the use and applications of LBSs. The current location determination technologies and standards are presented in Section 3. In Section 4 we describe the mathematical models used for the location and velocity estimation algorithms. An initial attempt for MS location estimation via received signal level using the maximum likelihood estimation (MLE) approach and triangulation is presented in Sections 5. Since the former approach lacks acceptable accuracy for demanding services as numerical results reveal, the extended Kalman filter (EKF) approach, which is the main topic in this chapter, is introduced in Sections 6. In Section 7 we present numerical results. Section 8 provides concluding remarks.

  5. El lesbianismo como monstruosidad en El cumpleaños de Alicia de Henry Díaz Vargas

    E-print Network

    Muñ oz, Willy O.


    la única función de la mujer es su rol materno: Quiero en tu cuerpo poseer las rosas, el agua de corrientes luminosas, el sol, el cielo azul, la mar dormida, y hacer correr, en raptos amorosos, al través de tus flancos armoniosos las fuentes...


    E-print Network

    Dunn, Peter O.

    Tachycineta bicolor, pero no Existe Asignacio´n Diferencial con Relacio´n al Orden de Puesta ni al Sexo maternos a los huevos variara con el orden de puesta o el sexo de la progenie. Por lo tanto, no hubo

  7. Negotiating Performance

    E-print Network

    Taylor, Diana


    representado—el medio teatral ("becoming") y el contenido ("historically delimited possibility" = Madre). No hay realidad estable al nivel de contenido que se esté actualizando sobre la escena. Todo lo contrario—la realidad del rol materno es producto de... proceso mismo de teatralización social, el acto de asumir o re-presentar o atacar un rol proviniente de nuestros limitados repertorios sociales para fines que van más allá de lo estético. Por ejemplo, en vez de la noción dramática tradicional de la...


    PubMed Central

    Tremolada, Sara; Delbue, Serena; Ferrante, Pasquale


    Riassunto Alcuni virus possono essere trasmessi verticalmente da madre a figlio in seguito allo sviluppo, da parte della madre, di un’infezione primaria, ricorrente o cronica. La trasmissione materno-fetale dei virus, che può avvenire in utero (infezione congenita), durante il travaglio del parto (infezione perinatale), oppure attraverso l’allattamento (infezione postnatale), può causare aborto spontaneo, morte fetale, ritardo di crescita intrauterino, anomalie congenite e patologie neonatali o postnatali di diversa entità. Alcuni fattori di rischio sembrano influenzare l’incidenza di trasmissione materno-fetale dei virus, come ad esempio la presenza di altre infezioni virali, la carica virale materna, il tipo di infezione (primaria o ricorrente), la durata della rottura delle membrane, la modalità con cui avviene il parto, le condizioni socio-economiche e l’allattamento. Oggi è possibile prevenire la trasmissione materno-fetale di molti virus grazie all’utilizzo di vaccini, immunizzazione passiva e farmaci antivirali. Il rischio di trasmissione delle infezioni perinatali e postnatali, inoltre, può essere diminuito evitando l’allattamento o ricorrendo ad un parto cesareo. PMID:19216201

  9. En sus propias palabras: Víctor Hugo Rascón Banda

    E-print Network

    Day, Stuart A.


    ese nom bre, condenándome a la escritura. Mi madre siempre tuvo esas inclinaciones artísticas y alentó mi vicio por la lectura y mi vicio por la escritura. Desde niños, en la escuela prima ria, el sistema educativo de Chihuahua era tan avanzado... apellido Banda es por el lado materno. Mi abuelo era enemigo de los Rascón. Los Rascón eran porfiristas e incluso Benito Juárez los autorizó a usar su propia moneda -las monedas que usábamos en la familia en el siglo diecinueve-. Entonces, Porfirio...

  10. [Hepatic subcapsular hematoma: a case report and management update].


    Berveiller, P; Vandenbroucke, L; Popowski, T; Afriat, R; Sauvanet, E; Giovangrandi, Y


    Hepatic subcapsular hematoma (HSH) is a rare complication of pregnancy that keeps a materno-fetal high mortality rate. Given this severity, HSH management requires a prompt diagnosis and an appropriate care. Before focusing on the current management strategy of HSH, we illustrate this article with a clinical case presenting an original method of abdominal exploration, which has not been described to our knowledge. Thus, taking into account the presence of a moderate hemoperitoneum during a caesarean section procedure for HSH, introduction of laparoscopy through the same incision allowed a satisfactory evaluation of the abdominal cavity and hepatic area without performing an invasive midline laparotomy. PMID:22177755

  11. El realismo de los signos escénicos en el teatro de Elena Garro

    E-print Network

    Ø stergaard, Ane-Grethe


    concep ción tradicional, según la cual el amor materno es el único verdadero. Al mismo tiempo, sin embargo, la pregunta de Ramiro es tan ingenuamente provocadora que parece obvio interpretar la figura de la madre de acuerdo a la clásica estructura del..., una sola idea, una norma única que nunca son capaces de transgredir; están atados a su concepción de sí mismos como portadores de un papel social determinado: Don Fernando en su rol de padre/marido/agente del orden; Felipe en el suyo de adulto...

  12. A Comparison of the Histological Structure of the Placenta in Experimental Animals

    PubMed Central

    Furukawa, Satoshi; Kuroda, Yusuke; Sugiyama, Akihiko


    The primary function of the placenta is to act as an interface between the dam and fetus. The anatomic structure of the chorioallantoic placenta in eutherian mammals varies between different animal species. The placental types in eutherian mammals are classified from various standpoints based on the gross shape, the histological structure of the materno-fetal interface, the type of materno-fetal interdigitation, etc. Particularly, the histological structure is generally considered one of the most useful and instructive classifications for functionally describing placental type. In this system, three main types are recognized according to the cell layers comprising the interhemal area: (1) epitheliochorial type (horses, pigs and ruminants), (2) endotheliochorial type (carnivores) and (3) hemochorial type (primates, rodents and rabbits). The number of cell layers in the interhemal area is considered to modify the transfer of nutrients between maternal and fetal blood and is one of the important factors with respect to the difference in placental permeability between animal species. Therefore, in reproductive and developmental toxicity studies, careful attention should be paid to the histological structure of the interhemal area when extrapolating information concerning placental transfer characteristics to different animal species. PMID:24791062

  13. Molecular interactions in the placenta during malaria infection.


    Mens, Petra F; Bojtor, Edward C; Schallig, Henk D F H


    Placental malaria is the placental sequestration of Plasmodium falciparum infected erythrocytes that accumulate in the intervillous space, resulting in pathological alterations. The intervillous space, the main compartment for exchange of nutrients and delivery of oxygen to the fetus, is of utmost importance for fetal development. Events leading to adverse outcomes of placental malaria can be summarized in four steps: (1) accumulation of P. falciparum infected erythrocytes; (2) infiltration of monocytes and macrophages; (3) alteration of the placental cytokine balance and (4) pathogenesis of adverse pregnancy outcomes. These events are triggered by chemokines and cytokines leading to impaired materno-fetal exchange and damage to the placenta. This review describes the events during placental malaria infection at molecular level and presents a simplified model describing all crucial steps leading to adverse pregnancy outcomes based on a review of recent literature (August 2009). PMID:20933151

  14. Continuing harmonization of terminology and innovations for methodologies in developmental toxicology: Report of the 8th Berlin Workshop on Developmental Toxicity, 14-16 May 2014.


    Solecki, Roland; Rauch, Martina; Gall, Andrea; Buschmann, Jochen; Clark, Ruth; Fuchs, Antje; Kan, Haidong; Heinrich, Verena; Kellner, Rupert; Knudsen, Thomas B; Li, Weihua; Makris, Susan L; Ooshima, Yojiro; Paumgartten, Francisco; Piersma, Aldert H; Schönfelder, Gilbert; Oelgeschläger, Michael; Schaefer, Christof; Shiota, Kohei; Ulbrich, Beate; Ding, Xuncheng; Chahoud, Ibrahim


    This article is a report of the 8th Berlin Workshop on Developmental Toxicity held in May 2014. The main aim of the workshop was the continuing harmonization of terminology and innovations for methodologies used in the assessment of embryo- and fetotoxic findings. The following main topics were discussed: harmonized categorization of external, skeletal, visceral and materno-fetal findings into malformations, variations and grey zone anomalies, aspects of developmental anomalies in humans and laboratory animals, and innovations for new methodologies in developmental toxicology. The application of Version 2 terminology in the DevTox database was considered as a useful improvement in the categorization of developmental anomalies. Participants concluded that initiation of a project for comparative assessments of developmental anomalies in humans and laboratory animals could support regulatory risk assessment and university-based training. Improvement of new methodological approaches for alternatives to animal testing should be triggered for a better understanding of developmental outcomes. PMID:26073002

  15. Induction of controlled hypoxic pregnancy in large mammalian species.


    Brain, Kirsty L; Allison, Beth J; Niu, Youguo; Cross, Christine M; Itani, Nozomi; Kane, Andrew D; Herrera, Emilio A; Giussani, Dino A


    Progress in the study of pregnancy complicated by chronic hypoxia in large mammals has been held back by the inability to measure long-term significant reductions in fetal oxygenation at values similar to those measured in human pregnancy complicated by fetal growth restriction. Here, we introduce a technique for physiological research able to maintain chronically instrumented maternal and fetal sheep for prolonged periods of gestation under significant and controlled isolated chronic hypoxia beyond levels that can be achieved by habitable high altitude. This model of chronic hypoxia permits measurement of materno-fetal blood gases as the challenge is actually occurring. Chronic hypoxia of this magnitude and duration using this model recapitulates the significant asymmetric growth restriction, the pronounced cardiomyopathy, and the loss of endothelial function measured in offspring of high-risk pregnancy in humans, opening a new window of therapeutic research. PMID:26660546

  16. Hématome sous-capsulaire du foie rompu compliquant une stéatose hépatique aiguë gravidique

    PubMed Central

    Doumiri, Mouhssine; Elombila, Marie; Oudghiri, Nezha; Saoud, Anas Tazi


    L'hématome sous-capsulaire du foie est une complication rare de la grossesse, survenant le plus souvent dans le cadre d'une pré éclampsie ou d'un HELLP syndrome (Hemolysis, Elevated Liver enzymes, and Low Platelets Syndrome). Rare sont les cas décris au cours d'une stéatose hépatique aiguë gravidique. Nous rapportons le cas d'une parturiente de 33 ans, multipare, sans antécédents, admise aux urgences au terme d'une grossesse à 37 semaines d'aménorrhées, pour pré éclampsie compliquée d'une stéatose hépatique aiguë gravidique. L’échographie hépatique réalisée à l'admission était sans anomalie. Une césarienne a été réalisée en urgence devant une souffrance fœtale aiguë, au cours de laquelle a été mise en évidence une rupture de l'hématome sous capsulaire du foie s'accompagnant d'un état de choc hémorragique. La prise en charge a consisté à une polytransfusion et packing perihépatique. Le retrait du packing n'a été réalisé qu'au quatrième jour, après stabilisation clinicobiologique et régression de l'encéphalopathie hépatique. L’évolution en réanimation a été favorable avec sortie de la patiente au vingtième jour. La rupture de l'hématome sous-capsulaire du foie est extrêmement dangereuse et à haut risque materno-fœtal. L'association à la stéatose hépatique aggrave le pronostic. PMID:25667700

  17. The placental pursuit for an adequate oxidant balance between the mother and the fetus

    PubMed Central

    Herrera, Emilio A.; Krause, Bernardo; Ebensperger, German; Reyes, Roberto V.; Casanello, Paola; Parra-Cordero, Mauro; Llanos, Anibal J.


    The placenta is the exchange organ that regulates metabolic processes between the mother and her developing fetus. The adequate function of this organ is clearly vital for a physiologic gestational process and a healthy baby as final outcome. The umbilico-placental vasculature has the capacity to respond to variations in the materno-fetal milieu. Depending on the intensity and the extensity of the insult, these responses may be immediate-, mediate-, and long-lasting, deriving in potential morphostructural and functional changes later in life. These adjustments usually compensate the initial insults, but occasionally may switch to long-lasting remodeling and dysfunctional processes, arising maladaptation. One of the most challenging conditions in modern perinatology is hypoxia and oxidative stress during development, both disorders occurring in high-altitude and in low-altitude placental insufficiency. Hypoxia and oxidative stress may induce endothelial dysfunction and thus, reduction in the perfusion of the placenta and restriction in the fetal growth and development. This Review will focus on placental responses to hypoxic conditions, usually related with high-altitude and placental insufficiency, deriving in oxidative stress and vascular disorders, altering fetal and maternal health. Although day-to-day clinical practice, basic and clinical research are clearly providing evidence of the severe impact of oxygen deficiency and oxidative stress establishment during pregnancy, further research on umbilical and placental vascular function under these conditions is badly needed to clarify the myriad of questions still unsettled. PMID:25009498

  18. Retroviral envelope syncytin capture in an ancestrally diverged mammalian clade for placentation in the primitive Afrotherian tenrecs

    PubMed Central

    Cornelis, Guillaume; Vernochet, Cécile; Malicorne, Sébastien; Souquere, Sylvie; Tzika, Athanasia C.; Goodman, Steven M.; Catzeflis, François; Robinson, Terence J.; Milinkovitch, Michel C.; Pierron, Gérard; Heidmann, Odile; Dupressoir, Anne; Heidmann, Thierry


    Syncytins are fusogenic envelope (env) genes of retroviral origin that have been captured for a function in placentation. Syncytins have been identified in Euarchontoglires (primates, rodents, Leporidae) and Laurasiatheria (Carnivora, ruminants) placental mammals. Here, we searched for similar genes in species that retained characteristic features of primitive mammals, namely the Malagasy and mainland African Tenrecidae. They belong to the superorder Afrotheria, an early lineage that diverged from Euarchotonglires and Laurasiatheria 100 Mya, during the Cretaceous terrestrial revolution. An in silico search for env genes with full coding capacity within a Tenrecidae genome identified several candidates, with one displaying placenta-specific expression as revealed by RT-PCR analysis of a large panel of Setifer setosus tissues. Cloning of this endogenous retroviral env gene demonstrated fusogenicity in an ex vivo cell–cell fusion assay on a panel of mammalian cells. Refined analysis of placental architecture and ultrastructure combined with in situ hybridization demonstrated specific expression of the gene in multinucleate cellular masses and layers at the materno–fetal interface, consistent with a role in syncytium formation. This gene, which we named “syncytin-Ten1,” is conserved among Tenrecidae, with evidence of purifying selection and conservation of fusogenic activity. To our knowledge, it is the first syncytin identified to date within the ancestrally diverged Afrotheria superorder. PMID:25267646

  19. [Hearing impairment and language delay in infants: diagnostic and genetic].


    Lang-Roth, R


    This article gives an overview on important aspects of hearing and language development of infants and toddlers. Newborn hearing screening is implemented in Germany for all infants since January 2009. The realization of early postnatal hearing screening is regulated by a publication of the "Gemeinsamer Bundesausschuss". It regulates the measurement method (TEOAE or AABR screening) and differs between healthy and sick newborns. It also rules the timetable of rescreening and if it still fails of paedaudiological follow up. The second part refers to objective and subjective assessment of hearing loss and different important issues of permanent childhood hearing impairment are discussed. Especially CMV infection by materno-fetal transmission and hereditary hearing loss is addressed in comparison to otitis media with effusion. Speech and language development in the first three years of live and the corresponding nomenclature is introduced in the last part. Different parent questionnaires are well established in evaluation of early language acquisition. An early diagnosis of language delay is possible and therapeutic measures can be established to prevent further social and psychological problems. PMID:24710780

  20. Nutritional programming of disease: unravelling the mechanism

    PubMed Central

    Langley-Evans, Simon C


    Nutritional programming is the process through which variation in the quality or quantity of nutrients consumed during pregnancy exerts permanent effects upon the developing fetus. Programming of fetal development is considered to be an important risk factor for non-communicable diseases of adulthood, including coronary heart disease and other disorders related to insulin resistance. The study of programming in relation to disease processes has been advanced by development of animal models, which have utilized restriction or over-feeding of specific nutrients in either rodents or sheep. These consistently demonstrate the biological plausibility of the nutritional programming hypothesis and, importantly, provide tools with which to examine the mechanisms through which programming may occur. Studies of animals subject to undernutrition in utero generally exhibit changes in the structure of key organs such as the kidney, heart and brain. These appear consistent with remodelling of development, associated with disruption of cellular proliferation and differentiation. Whilst the causal pathways which extend from this tissue remodelling to disease can be easily understood, the processes which lead to this disordered organ development are poorly defined. Even minor variation in maternal nutritional status is capable of producing important shifts in the fetal environment. It is suggested that these environmental changes are associated with altered expression of key genes, which are responsible for driving the tissue remodelling response and future disease risk. Nutrition-related factors may drive these processes by disturbing placental function, including control of materno-fetal endocrine exchanges, or the epigenetic regulation of gene expression. PMID:19175805

  1. The HLA-G*0105N null allele induces cell surface expression of HLA-E molecule and promotes CD94/NKG2A-mediated recognition in JAR choriocarcinoma cell line.


    Sala, Frédéric G; Del Moral, Pierre-Marie; Pizzato, Nathalie; Legrand-Abravanel, Florence; Le Bouteiller, Philippe; Lenfant, Françoise


    HLA-G is a non-classical HLA class Ib molecule primarily expressed in trophoblast cells, and is thought to play a key role in the induction of materno-fetal tolerance during pregnancy. In addition, the HLA-G gene provides a suitable leader sequence peptide capable of binding to HLA-E. However, the existence of placentas homozygous for the HLA-G*0105N null allele suggests that HLA-G1 might not be essential for fetal survival. To investigate whether expression of the HLA-G*0105N allele supports HLA-E cell surface expression, we transfected the HLA-G*0105N gene into JAR trophoblast cells. Flow cytometry analysis showed that HLA-G*0105N-transfected cells express surface HLA-E to a similar extent as the unmutated HLA-G gene, whereas HLA-G1 cell surface expression was undetectable. Using the NKL cell line in a standard (51)Cr release assay, the HLA-E molecules were found to inhibit natural killer lysis, through a mechanism partially dependent on CD94/NKG2A-mediated recognition. PMID:15578261

  2. Perfluoroalkyl acid (PFAA) levels and profiles in breast milk, maternal and cord serum of French women and their newborns.


    Cariou, Ronan; Veyrand, Bruno; Yamada, Ami; Berrebi, Alain; Zalko, Daniel; Durand, Sophie; Pollono, Charles; Marchand, Philippe; Leblanc, Jean-Charles; Antignac, Jean-Philippe; Le Bizec, Bruno


    One major concern regarding perfluoroalkyl acids (PFAAs) is their potential role in onset of health troubles consecutive to early exposure during the perinatal period. In the present work, the internal exposure levels of 18 targeted PFAAs were determined in ca. 100 mother-newborn pairs recruited in France between 2010 and 2013. In serum, the cumulated concentrations of the 7 most frequently detected compounds were 5.70ng/mL and 2.83ng/mL (median values) in maternal and cord serum, respectively. Perfluorooctanesulfonic acid (PFOS), perfluorooctanoic acid (PFOA), perfluorohexylesulfonic acid (PFHxS) and perfluorononanoic acid (PFNA) contributed to around 90% of the total PFAAs contamination, with concentration levels and contamination profiles in accordance with other published work in Europe. Levels measured in breast milk were far lower (20 to 150 fold) than those determined in serum. Associations between the different monitored substances as well as between levels determined in the different investigated biological matrices mostly do not appear statistically significant. The estimated materno-foetal transfer would be thus substance-dependant, mainly driven by the physico-chemical properties of the different PFAAs (nature of polar group and length of alkylated side chain). We conclude that trans-placental passage and breastfeeding are both significant routes of human exposure to PFAAs. PMID:26232143

  3. Frequency of Maternal and Newborn Birth Outcomes, Lima, Peru, 2013

    PubMed Central

    Wynn, Adriane; Cabeza, Jeanne; Adachi, Kristina; Needleman, Jack; Garcia, Patricia J.; Klausner, Jeffrey D.


    Objective This study describes the pregnancy and birth outcomes at two hospitals in Lima, Peru. The data collection and analysis is intended to inform patients, providers, and policy makers on Peru’s progress toward achieving the Millennium Development Goals and to help set priorities for action and further research. Methods Data were collected retrospectively from a sample of 237 women who delivered between December 2012 and September 2013 at the Instituto Nacional Materno Perinatal or the Hospital Nacional Arzobispo Loayza. The outcomes were recorded by a trained mid-wife through telephone interviews with patients and by review of hospital records. Associations between participant demographic characteristics and pregnancy outcomes were tested with Chi-squared, Fisher’s exact, or Student’s t-test. Results Over 37% of women experienced at least one maternal or perinatal complication, and the most frequent were hypertension/preeclampsia and macrosomia. The women in our sample had a cesarean section rate of 50.2%. Conclusion Maternal and perinatal complications are not uncommon among women in the lower socioeconomic strata of Lima. Also, the high cesarean rate underpins the need for a more comprehensive understanding of the indications for cesarean section deliveries, which could help reduce the number of unnecessary procedures and preventable complications. PMID:25806522

  4. Retroviral envelope syncytin capture in an ancestrally diverged mammalian clade for placentation in the primitive Afrotherian tenrecs.


    Cornelis, Guillaume; Vernochet, Cécile; Malicorne, Sébastien; Souquere, Sylvie; Tzika, Athanasia C; Goodman, Steven M; Catzeflis, François; Robinson, Terence J; Milinkovitch, Michel C; Pierron, Gérard; Heidmann, Odile; Dupressoir, Anne; Heidmann, Thierry


    Syncytins are fusogenic envelope (env) genes of retroviral origin that have been captured for a function in placentation. Syncytins have been identified in Euarchontoglires (primates, rodents, Leporidae) and Laurasiatheria (Carnivora, ruminants) placental mammals. Here, we searched for similar genes in species that retained characteristic features of primitive mammals, namely the Malagasy and mainland African Tenrecidae. They belong to the superorder Afrotheria, an early lineage that diverged from Euarchotonglires and Laurasiatheria 100 Mya, during the Cretaceous terrestrial revolution. An in silico search for env genes with full coding capacity within a Tenrecidae genome identified several candidates, with one displaying placenta-specific expression as revealed by RT-PCR analysis of a large panel of Setifer setosus tissues. Cloning of this endogenous retroviral env gene demonstrated fusogenicity in an ex vivo cell-cell fusion assay on a panel of mammalian cells. Refined analysis of placental architecture and ultrastructure combined with in situ hybridization demonstrated specific expression of the gene in multinucleate cellular masses and layers at the materno-fetal interface, consistent with a role in syncytium formation. This gene, which we named "syncytin-Ten1," is conserved among Tenrecidae, with evidence of purifying selection and conservation of fusogenic activity. To our knowledge, it is the first syncytin identified to date within the ancestrally diverged Afrotheria superorder. PMID:25267646


    PubMed Central

    Winder, Nicola R.; Krishnaveni, Ghattu V.; Veena, Sargoor R.; Hill, Jacqueline C.; Karat, Chitra L.S.; Thornburg, Kent L.; Fall, Caroline H.D.; Barker, David J.P.


    Background Studies have shown that the shape and size of the placenta at birth predict blood pressure in later life. The influences that determine placental morphology are largely unknown. We have examined the role of mother’s body size. Methods We studied 522 neonates who were born in a maternity hospital in Mysore, South India. The weight of the placenta and the length and breadth of its surface, were measured after delivery. Results Higher maternal fat mass predicted a larger placental surface (p=0.02), while larger maternal head circumference predicted a more oval placental surface (p=0.03). Higher maternal fat mass and larger maternal head circumference were associated with greater placental efficiency, indicated by lower ratios of the length (p=0.0003 and p=0.0001 respectively) and breadth (p=0.0002 and p<0.0001) of the surface to birthweight. In a sub-sample of 51 mothers whose own birthweight was available, higher maternal birthweight was related to lower ratios of the length and breadth of the surface to birthweight (p=0.01 and 0.002). Maternal height was unrelated to placental size or shape. Conclusions Higher maternal fat mass, reflecting the mother’s current nutritional state, and larger maternal head circumference, reflecting the mother’s fetal/infant growth, are associated with changes in the shape and size of the placental surface and greater placental efficiency. We suggest that these associations reflect effects of the mother’s nutrition at different stages of her lifecourse on the development of the placenta and on materno-placento-fetal transfer of nutrients. PMID:21924491

  6. The Long and the Short of it: Gene and Environment Interactions During Early Cortical Development and Consequences for Long-Term Neurological Disease

    PubMed Central

    Stolp, Helen; Neuhaus, Ain; Sundramoorthi, Rohan; Molnár, Zoltán


    Cortical development is a complex amalgamation of proliferation, migration, differentiation, and circuit formation. These processes follow defined timescales and are controlled by a combination of intrinsic and extrinsic factors. It is currently unclear how robust and flexible these processes are and whether the developing brain has the capacity to recover from disruptions. What is clear is that there are a number of cognitive disorders or conditions that are elicited as a result of disrupted cortical development, although it may take a long time for the full pathophysiology of the conditions to be realized clinically. The critical window for the manifestation of a neurodevelopmental disorder is prolonged, and there is the potential for a complex interplay between genes and environment. While there have been extended investigations into the genetic basis of a number of neurological and mental disorders, limited definitive associations have been discovered. Many environmental factors, including inflammation and stress, have been linked to neurodevelopmental disorders, and it may be that a better understanding of the interplay between genes and environment will speed progress in this field. In particular, the development of the brain needs to be considered in the context of the whole materno-fetal unit as the degree of the metabolic, endocrine, or inflammatory responses, for example, will greatly influence the environment in which the brain develops. This review will emphasize the importance of extending neurodevelopmental studies to the contribution of the placenta, vasculature, cerebrospinal fluid, and to maternal and fetal immune response. These combined investigations are more likely to reveal genetic and environmental factors that influence the different stages of neuronal development and potentially lead to the better understanding of the etiology of neurological and mental disorders such as autism, epilepsy, cerebral palsy, and schizophrenia. PMID:22701439

  7. Effects of estrogen coadministration on epoxiconazole toxicity in rats.


    Stinchcombe, Stefan; Schneider, Steffen; Fegert, Ivana; Rey Moreno, Maria Cecilia; Strauss, Volker; Gröters, Sibylle; Fabian, Eric; Fussell, Karma C; Pigott, Geoffrey H; van Ravenzwaay, Bennard


    Epoxiconazole (EPX; CAS-No. 133855-98-8) is a triazole class-active substance of plant protection products. At a dose level of 50 mg/kg bw/day, it causes a significantly increased incidence of late fetal mortality when administered to pregnant rats throughout gestation (gestation day [GD] 7-18 or 21), as reported previously (Taxvig et al., 2007, 2008) and confirmed in these studies. Late fetal resorptions occurred in the presence of significant maternal toxicity such as clear reduction of corrected body weight gain, signs of anemia, and, critically, a marked reduction of maternal estradiol plasma levels. Furthermore, estradiol supplementation at dose levels of 0.5 or 1.0 ?g/animal/day of estradiol cyclopentylpropionate abolished the EPX-mediated late fetal resorptions. No increased incidences of external malformations were found in rats cotreated with 50 mg/kg bw/day EPX and estradiol cyclopentylpropionate, indicating that the occurrence of malformations was not masked by fetal mortality under the study conditions. Overall, the study data indicate that fetal mortality observed in rat studies with EPX is not the result of direct fetal toxicity but occurs indirectly via depletion of maternal estradiol levels. The clarification of the human relevance of the estrogen-related mechanism behind EPX-mediated late fetal resorptions in rats warrants further studies. In particular, this should involve investigation of the placenta (Rey Moreno et al., 2013), since it is the materno-fetal interface and crucial for fetal maintenance. The human relevance is best addressed in a species which is closer to humans with reference to placentation and hormonal regulation of pregnancy, such as the guinea pig (Schneider et al., 2013). PMID:23720304

  8. Profil épidémiologique des femmes enceintes cardiaques dans le centre de maternité de Tunis: expérience du service A

    PubMed Central

    Khemiri, Khaled; Jenayah, Amel Achour; Boudaya, Fethia; Hamdi, Asma; Meskhi, Souad; Sfar, Ezzeddine; Chelli, Dalenda


    Nous rapportons dans ce travail, le profil épidémiologique des femmes enceintes porteuses d'une cardiopathie ayant accouché dans le service «A» du centre de maternité de Tunis. Il s'agit d'une étude rétrospective descriptive sur 3 ans, de janvier 2010 à décembre 2012, portant sur les dossiers des parturientes cardiaques suivies et ayant accouché dans notre service, à l'exclusion des cardiopathies hypertensives. Les paramètres analysés étaient la gestité et parité des parturientes, le type de la cardiopathie, le mode d'accouchement et le pronostic foetal. Cinquante six cas sur 19655 accouchements avaient été recrutés, soit une incidence de 1 pour 351 accouchements (0,285%). L’âge moyen de nos parturientes était de 30,89±5,3 ans avec des extrêmes allant de 21 à 42 ans. 23 (41,07%) avaient une cardiopathie congénitale, 35 (62,5%) une valvulopathie, 6 (10,71%) un trouble du rythme, 3 (5,35%) un trouble de la conduction à type de bloc auriculo-ventriculaire et 3 (5,35%) une cardiopathie ischémique. Cinquante deux parturientes (92,85%) avaient accouché à un terme dépassant les 37 semaines d'aménorrhée (SA). L'accouchement s'est déroulé par les voies naturelles chez 22 (39,28%) patientes et par césarienne chez 34 (60,71%). Le poids moyen des nouveaux nés à la naissance était de 3341,25 grammes. 3 transferts néonataux en unité de réanimation étaient réalisés avec un seul cas de décès néonatal. La grossesse et l'accouchement chez la femme cardiaque constituent un haut risque materno-foetal dépendant du type, mais surtout du stade de la cardiopathie, nécessitant une prise en charge précoce et multidisciplinaire de la parturiente. PMID:26327977

  9. Umbilical cord PUFA are determined by maternal and child fatty acid desaturase (FADS) genetic variants in the Avon Longitudinal Study of Parents and Children (ALSPAC)

    PubMed Central

    Lattka, Eva; Koletzko, Berthold; Zeilinger, Sonja; Hibbeln, Joseph R.; Klopp, Norman; Ring, Susan M.; Steer, Colin D.


    Fetal supply with long-chain PUFA (LC-PUFA) during pregnancy is important for brain growth and visual and cognitive development and is provided by materno–fetal placental transfer. We recently showed that maternal fatty acid desaturase (FADS) genotypes modulate the amounts of LC-PUFA in maternal blood. Whether FADS genotypes influence the amounts of umbilical cord fatty acids has not been investigated until now. The aim of the present study was to investigate the influence of maternal and child FADS genotypes on the amounts of LC-PUFA in umbilical cord venous plasma as an indicator of fetal fatty acid supply during pregnancy. A total of eleven cord plasma n-6 and n-3 fatty acids were analysed for association with seventeen FADS gene cluster SNP in over 2000 mothers and children from the Avon Longitudinal Study of Parents and Children. In a multivariable analysis, the maternal genotype effect was adjusted for the child genotype and vice versa to estimate which of the two has the stronger influence on cord plasma fatty acids. Both maternal and child FADS genotypes and haplotypes influenced amounts of cord plasma LC-PUFA and fatty acid ratios. Specifically, most analysed maternal SNP were associated with cord plasma levels of the precursor n-6 PUFA, whereas the child genotypes were mainly associated with more highly desaturated n-6 LC-PUFA. This first study on FADS genotypes and cord fatty acids suggests that fetal LC-PUFA status is determined to some extent by fetal fatty acid conversion. Associations of particular haplotypes suggest specific effects of SNP rs498793 and rs968567 on fatty acid metabolism. PMID:22877655

  10. Hypoxia-Induced Changes in the Bioactivity of Cytotrophoblast-Derived Exosomes

    PubMed Central

    Salomon, Carlos; Kobayashi, Miharu; Ashman, Keith; Sobrevia, Luis; Mitchell, Murray D.; Rice, Gregory E.


    Migration of extravillous trophoblasts (EVT) into decidua and myometrium is a critical process in the conversion of maternal spiral arterioles and establishing placenta perfusion. EVT migration is affected by cell-to-cell communication and oxygen tension. While the release of exosomes from placental cells has been identified as a significant pathway in materno-fetal communication, the role of placental-derived exosomes in placentation has yet to be established. The aim of this study was to establish the effect of oxygen tension on the release and bioactivity of cytotrophoblast (CT)-derived exosomes on EVT invasion and proliferation. CT were isolated from first trimester fetal tissue (n?=?12) using a trypsin-deoxyribonuclease-dispase/Percoll method. CT were cultured under 8%, 3% or 1% O2 for 48 h. Exosomes from CT-conditioned media were isolated by differential and buoyant density centrifugation. The effect of oxygen tension on exosome release (µg exosomal protein/106cells/48 h) and bioactivity were established. HTR-8/SVneo (EVT) were used as target cells to establish the effect (bioactivity) of exosomes on invasion and proliferation as assessed by real-time, live-cell imaging (Incucyte™). The release and bioactivity of CT-derived exosomes were inversely correlated with oxygen tension (p<0.001). Under low oxygen tensions (i.e. 1% O2), CT-derived exosomes promoted EVT invasion and proliferation. Proteomic analysis of exosomes identified oxygen-dependent changes in protein content. We propose that in response to changes in oxygen tension, CTs modify the bioactivity of exosomes, thereby, regulating EVT phenotype. Exosomal induction of EVT migration may represent a normal process of placentation and/or an adaptive response to placental hypoxia. PMID:24244532

  11. A Gestational Profile of Placental Exosomes in Maternal Plasma and Their Effects on Endothelial Cell Migration

    PubMed Central

    Salomon, Carlos; Torres, Maria Jose; Kobayashi, Miharu; Scholz-Romero, Katherin; Sobrevia, Luis; Dobierzewska, Aneta; Illanes, Sebastian E.; Mitchell, Murray D.; Rice, Gregory E.


    Studies completed to date provide persuasive evidence that placental cell-derived exosomes play a significant role in intercellular communication pathways that potentially contribute to placentation and development of materno-fetal vascular circulation. The aim of this study was to establish the gestational-age release profile and bioactivity of placental cell-derived exosome in maternal plasma. Plasma samples (n?=?20 per pregnant group) were obtained from non-pregnant and pregnant women in the first (FT, 6–12 weeks), second (ST, 22–24 weeks) and third (TT, 32–38 weeks) trimester. The number of exosomes and placental exosome contribution were determined by quantifying immunoreactive exosomal CD63 and placenta-specific marker (PLAP), respectively. The effect of exosomes isolated from FT, ST and TT on endothelial cell migration were established using a real-time, live-cell imaging system (Incucyte). Exosome plasma concentration was more than 50-fold greater in pregnant women than in non-pregnant women (p<0.001). During normal healthy pregnancy, the number of exosomes present in maternal plasma increased significantly with gestational age by more that two-fold (p<0.001). Exosomes isolated from FT, ST and TT increased endothelial cell migration by 1.9±0.1, 1.6±0.2 and 1.3±0.1-fold, respectively compared to the control. Pregnancy is associated with a dramatic increase in the number of exosomes present in plasma and maternal plasma exosomes are bioactive. While the role of placental cell-derived exosome in regulating maternal and/or fetal vascular responses remains to be elucidated, changes in exosome profile may be of clinical utility in the diagnosis of placental dysfunction. PMID:24905832

  12. The tissue bank at the national nuclear research institute in Mexico.


    Esther Martínez-Pardo, María; Lourdes Reyes-Frías, Ma


    The Instituto Nacional de Investigaciones Nucleares (ININ, The National Nuclear Research Institute) received during 1997-1998 strong support of the International Atomic Energy Agency (IAEA), to establish the first and only one tissue bank (BTR ININ tissue bank) in Mexico that uses ionising radiation as sterilising agent. In that time, the BTR staff was trained in different tissue banks in several countries. Basic equipment for tissue processing donated by the IAEA was received in 1998. In July, 1999 the Mexican Health Secretariat gave the Sanitary License No. 1062000001 to the BTR to operate as an official organ and tissue bank. In August, 2001 the ININ and the Hospital Materno Infantil (HMI-ISSEMYM) signed an agreement to collaborate in amnion processing. The hospital is responsible for donor selection, serology tests, tissue procurement and washing, since this hospital is the BTR amnion supplier. The tissues are collected by ININ weekly with complete documentation. The BTR is responsible for processing: cleaning, air drying, packaging, labelling, microbiological control and sterilisation by gamma irradiation. The sterilised tissue is kept under quarantine for 6 months to obtain the results of the donor second serology test. From March to June, 2002 the BTR has processed 347.86 units (50 cm(2) each), is say, 17,393 cm(2). In addition, the pig skin xenograft process has been implemented and a protocol for clinical applications of it is running at the Hospital Central Sur de Alta Especialidad (PEMEX). Also the ININ tissue bank present status and perspectives are described. PMID:15256855


    PubMed Central

    Chávez, Natividad; Molina, Helfer; Sánchez, Jorge; Gelaye, Bizu; Sánchez, Sixto E.


    Vaginosis bacteriana (VB) es una infección caracterizada por el cambio en la microflora de la vagina, asociándose a resultados adversos del embarazo y a la adquisición de infecciones de transmisión sexual (ITS), incluyendo el VIH. En este estudio se buscó la asociación entre el uso de duchas vaginales y otros factores de riesgos con VB. Se usó un diseño observacional descriptivo transversal prospectivo, en 1,252 mujeres que asistieron al servicio de planificación familiar de tres hospitales nacionales (Dos de Mayo, Arzobispo Loayza, San Bartolomé) y el Instituto Materno Perinatal, durante el año 1997. Se utilizó un cuestionario estructurado donde se registraron variables socio demográficas y características del estilo de vida de las participantes. VB fue diagnosticada mediante el puntaje de Nugent. Se empleó análisis de regresión logística para calcular odds ratio (OR) e intervalos de confianza al 95%. La edad promedio de las participantes fue 25.1 ± 4,7 años, el 23.4% tenían más de 11 años de educación. La prevalencía de VB fue 20,1%. Las mujeres que practicaban duchas vaginales tuvieron 2.28 veces (OR = 2.28, IC 95% [1.0–5.0]) mayor probabilidad de tener VB comparado con aquellas que no lo practicaban. Tener dos o más parejas sexuales estuvo asociado con 2.0 veces (OR =2.0, IC 95% [1.2–3.5]) mayor probabilidad de adquirir VB comparado con aquellas que habían tenido solo una pareja sexual. Las participantes que iniciaron una relación sexual a una edad temprana tuvieron 1.4 veces (OR=1.4, IC 95% [1.0 –1.9]) mayor probabilidad de adquirir VB. El uso de duchas vaginales es un factor de riesgo de VB. Los programas destinados a la salud de la mujer deben abordar las repercusiones perjudiciales para la salud asociados con las duchas vaginales. PMID:21132048

  14. Meeting health and family planning needs in Latin America and the Caribbean.



    The operations research and technical assistance (OR/TA) project in The Population Council has concentrated on fertility and infant mortality issues in Latin American and the Caribbean for more than a decade through INOPAL. INOPAL is an acronym for Investigacion Operacional en Planificacion Familiar y Atencion Materno-Infantil para America Latina y el Caribe (Operations Research in Family Planning and Maternal-Child Health in Latin America and the Caribbean). In March 1995, the project entered its third phase, INOPAL III, with the renewal of its contract from the United States Agency for International Development (USAID). To facilitate communication between INOPAL, collaborating agencies, and USAID, INOPAL Director James Foreit moved from Peru to a Council office in Washington, D.C. INOPAL has six objectives: 1) to test the integration of family planning and reproductive health services; 2) to increase access to family planning; 3) to develop strategies to reach special populations; 4) to improve the sustainability of family planning programs; 5) to improve service quality; and 6) to institutionalize operations research capability in the region. INOPAL II conducted 61 subprojects in 12 countries in collaboration with 24 USAID cooperating agencies and other international organizations. The project established new services for postpartum women, adolescents, and rural women; improved program quality and financial sustainability; increased vasectomy promotion and the range of available contraceptives; and developed new modes of service delivery. A key finding of INOPAL II operations research was the importance of increasing cost-effectiveness to ensure program sustainability. INOPAL III will work toward all six objectives, with an emphasis on integrating reproductive health and family planning services. Operations research and technical assistance (OR/TA) subprojects will focus on the prevention and treatment of sexually transmitted diseases, perinatal and postpartum care, and postabortion care. PMID:12319543

  15. [Morphological variability and placental function].


    Malassiné, A


    In mammals, the blastocyst defines with the maternal organism, a structure which allows embryonic development during gestation: the placenta. The structure of this organ varies remarkably across species. In this review the different type of placentation have been described in a comparative manner using terms of classification such as: placental materno-fetal interdigitation, matemofetal blood flow interrelationships, layers of the placental interhemal barrier, trophoblast invasiveness and decidual cell reaction, formation of syncytiotrophoblast. The human hemomonochorial placenta is characterized by a strong decidualization of the uterus and a major invasiveness of the extravillous trophoblast. Furthermore, there is a spectrum of placental endocrine activities across species. In some mammals (e.g., mouse and rat) the placenta eclipses the pituitary in the maintenance of ovarian function. In the human and in the sheep, horse, cat and guinea pig, the placenta acquires the ability to substitute for the ovaries in the maintenance of gestation at various time during pregnancy. The human placenta is characterized by a high rate of steroïdogenesis (progesterone and estrogens) and by the production of a primate specific trophoblastic hormone: human chorionic gonadotropin (hCG). Recently, it was demonstrated that mutation of many genes in mice results in embryonic mortality or fetal growth restriction, due to defects in placental development. Furthermore, distinct molecular pathways regulate the differentiation of various trophoblast cell subtype of the mouse placenta. An important question is whether or not placental differentiation in other mammals is regulated by the same molecular mechanisms. Due to the striking diversity in placental structure, endocrine function and gene expression, caution must be exercised in extrapolating findings regarding placental function and development from one species to another. PMID:11575143

  16. ["CLAPSEN", a global approach to the rehabilitation of severe childhood malnutrition in Bolivia].


    Sevilla, R; Sejas, E; Zalles, L; Belmonte, G; Chevalier, P; Parent, G; Katherine, H; Kolsteren, P


    The "CLAPSEN" approach was developed at the Hospital Materno Infantil German Urquidi in Cochabamba, to provide a global response for the study and treatment of childhood malnutrition. "CLAPSEN" is short for Clinical, Laboratory, Anthropometry, Psychology, Sociology, Nursing (Enfermera in Spanish) and Nutritional care. Most of the malnourished children admitted to Cochabamba Hospital are from poor families, more than three quarters of whom have only recently arrived in the city. Acute malnutrition is just one of the manifestations of a generally unfavorable environment. Malnutrition should not be considered as a simple deficiency in energy, protein or micronutrients, but rather as a multi-deficiency syndrome, also involving a lack of basic health and social care. This study demonstrates that malnourished children display a considerable degree of psychological retardation and of immune system depression. After five weeks of rehabilitation, the children were considered to have recuperated physically, as assessed by anthropometry, but not psychologically, as assessed by the adapted Dewer Score, or immunologically, as shown by the size of the thymus or the extent of maturation of lymphocytes. This strategy was not designed as a long-term approach for treating malnutrition, but rather as a research project to characterize the children arriving at the hospital, to determine the reasons for their malnutrition and to identify strategies that could be implemented earlier by health centers of social services, to prevent deterioration in the condition of these children to severe malnutrition requiring hospital admission. We believe that, in this Latin American context, in which the rate of acute malnutrition is low, the hospital should continue to be involved in the treatment of severely malnourished children with associated diseases. The child's stay in hospital should be short and once the child has recovered clinically, he should be sent home. In light of the observed levels of social deprivation, psychosocial and immune deficits, there appears to be a need for continued support for the family, to ensure the full recovery of the child and to prevent relapses. PMID:10960806

  17. Characterization of the immune response in the placenta of cattle experimentally infected with Neospora caninum in early gestation.


    Maley, S W; Buxton, D; Macaldowie, C N; Anderson, I E; Wright, S E; Bartley, P M; Esteban-Redondo, I; Hamilton, C M; Storset, A K; Innes, E A


    A serial examination of three groups of cattle infected intravenously (iv) (Group 1, n=8) or subcutaneously (sc) (Group 2, n=8) with live Neospora caninum tachyzoites or with VERO cells (Group 3, n=8) at 70 days' gestation was carried out and the nature of the inflammatory responses in the placenta and the presence of parasite antigen were analysed. Immune cells expressing CD3, CD4, CD8, gamma delta (gammadelta) T-cell receptors (TCR), CD79alpha cytoplasmic (cy) (B cells) and NKp46 [natural killer (NK) cells] antigens were identified immunohistochemically and cells expressing mRNA for interferon-gamma (IFN-gamma) were labelled by in-situ hybridization. Intravenous inoculation caused mortality in all fetuses from 28 days post-inoculation (dpi) onwards. Subcutaneous inoculation caused mortality in 50% of the animals by 28dpi. Pathological changes in the placenta consisted of necrosis of fetal placental villi, necrosis and inflammation in adjacent areas of the maternal septum and inflammation at the base of the maternal caruncle. The inflammatory infiltrate consisted mainly of CD3(+) lymphocytes, dominated by CD4(+) and gammadelta TCR(+) cells, with CD8(+) cells present to a lesser extent. The results from the control group indicated fewer NK cells than those occurring in the placenta of human beings or mice. Infiltration of CD4(+) cells and NKp46(+) cells was observed in the caruncular base and septa 14 days after infection, whereas infiltration of gammadelta TCR(+) cells was observed from 28 dpi onwards. To our knowledge this is the first report on the presence and distribution of NK cells in the bovine placenta. Maternal inflammatory cells expressing mRNA for IFN-gamma were identified in animals inoculated with parasites iv or sc at 14 and 28 dpi, respectively. In the sc-inoculated dams with live fetuses at 28, 42 and 56dpi, there was no evidence of parasite antigen, infiltration of immune cells or production of IFN-gamma, suggesting that the parasite had not reached the placenta. The exact cause of fetal death was not established. Tissue destruction by the parasite may have occurred; in addition, there may have been a T helper 1 (Th-1) immune response to the neospora infection at the materno-fetal interface, resulting in infiltrations of CD4T cells, gammadelta T cells and NK cells and the subsequent production of IFN-gamma. It is possible that a pro-inflammatory Th-1 response early in gestation protects the dam by eliminating the parasite; however, it may lead to destruction of the placental tissues themselves and thus be incompatible with fetal survival. PMID:16997005

  18. Tumores neonatales y malformaciones congénitas

    PubMed Central

    Tornero, O. Berbel; García, J.A. Ortega; Tortajada, J. Ferrís i; Castell, J. García; Colomer, J. Donat i; Soldin, O.P.; Soler, J.L. Fuster


    Introducción La asociación entre tumores y malformaciones congénitas está bien establecida, pero no existen datos exclusivos en el período neonatal y se desconocen los mecanismos subyacentes que generan dicha relación. Objetivos Este trabajo tiene dos objetivos: primero, analizar la frecuencia de los tumores neonatales asociados a malformaciones congénitas, y segundo, comentar las posibles hipótesis etiopatogénicas de la relación entre ambas entidades. Materiales y método Estudio retrospectivo de las historias clínicas de los tumores neonatales, en el Hospital Universitario Materno- Infantil La Fe de Valencia, desde enero de 1990 hasta diciembre de 1999. Selección y descripción de las variedades histológicas asociadas a malformaciones congénitas. Éstas se han agrupado siguiendo los criterios de la Clasificación Internacional de Enfermedades CIE-9, códigos 740.0–759.9. Revisión sistemática bibliográfica de los últimos 25 años, obtenida del Medline, Cancerlit, Index Citation Science y Embase. El perfil de búsqueda utilizado fue la combinación de “neonatal/congenital-tumors/cancer/neoplasms” y “congenital malformations/birth defects”. Resultados Se identificaron 72 tumores neonatales (2,8 % del total de tumores pediátricos diagnosticados en dichos años) y 15 de ellos (20,8 %) asociados a malformaciones congénitas, enfermedades o síndromes congénitos. Las asociaciones entre tumores neonatales y malformaciones congénitas fueron las siguientes: a) angioma en 3 pacientes: con dos cardiopatías congénitas y una atresia de coanas-laringomalacia; b) neuroblastoma en 2 pacientes: uno con riñón en herradura y anomalías vertebrales, y otro con cardiopatía congénita; c) teratoma en 2 pacientes: uno con fisura palatina y anomalías vertebrales, y otro con metatarso varo; d) tumor del sistema nervioso central en un paciente con hernia de Bochdaleck; e) tumor cardíaco en 4 pacientes con esclerosis tuberosa; f) leucemia aguda en un paciente con síndrome de Down y cardiopatía congénita; g) tumor renal en un caso con hidrocefalia triventricular, y h) tumor adrenal en un caso con hemihipertrofia. En la bibliografía específica, las publicaciones engloban tumores de diferentes épocas pediátricas y sin unanimidad de criterios para clasificar las malformaciones congénitas. Apenas existen datos en el período neonatal y la asociación entre ambas entidades se obtiene de registros de instituciones médicas. La prevalencia oscila entre el 15 y el 31,6 %. Las hipótesis etiopatogénicas que explican la asociación entre tumores neonatales y malformaciones congénitas están basadas en las exposiciones prenatales (preconcepcionales y transplacentarias) a factores de riesgo potencialmente mutagénicos y carcinogénicos. Conclusiones Probablemente, los tumores neonatales se asocian con mayor frecuencia a malformaciones congénitas que los tumores diagnosticados en épocas posteriores de la vida. Para conocer la prevalencia real de la asociación entre tumores neonatales y malformaciones congénitas, es necesario unificar los criterios de inclusión y definición de ambas entidades. La obtención de una minuciosa historia medioambiental en todos los tumores neonatales asociados a malformaciones congénitas, donde se detallen y registren todos los factores de riesgo constitucionales y ambientales, es fundamental para mejorar nuestros escasos conocimientos de los mecanismos prenatales subyacentes y avanzar en su prevención. PMID:18559198

  19. The host-parasite relationship in bovine neosporosis.


    Innes, Elisabeth A; Wright, Steve; Bartley, Paul; Maley, Stephen; Macaldowie, Colin; Esteban-Redondo, Irma; Buxton, David


    Infection with the protozoan parasite Neospora caninum is thought to be a major cause of reproductive failure in cattle worldwide. Cattle infected with the parasite are three to seven times more likely to abort compared to uninfected cattle. The parasite may be transmitted to cattle through the ingestion of oocysts that are shed in the faeces of acutely infected dogs (definitive host of N. caninum) or by congenital infection from mother to foetus via the placenta. Interestingly, transplacental transmission can occur over consecutive pregnancies and congenitally infected heifers can transmit the parasite to their own offspring. This repeated vertical transmission observed in naturally infected cattle suggests that cattle do not easily develop effective immunity to the parasite, presenting a significant challenge to the development of a control strategy based on vaccination. Neosporosis is a disease of pregnancy and studying the bovine maternal and foetal immune responses during pregnancy will help us to understand the change in the balance between the parasite and the host that may result in disease of the foetus. Studies in non-pregnant cattle and in murine models of infection have shown the importance of T-helper 1-type immune responses involving pro-inflammatory cytokines, such as IFNgamma and IL-12, in limiting intracellular multiplication of the parasite. During pregnancy, changes occur in the immune system allowing the mother to accept the foetal allograft. Research in other species has stressed the crucial role of T-helper 2-type cytokines at the materno-foetal interface in maintaining the pregnancy and regulating the potentially damaging effect of Th-1 responses. Studies in cattle have shown that cell proliferation and IFNgamma responses may be significantly down-regulated around mid-gestation. This may mean that cattle are less able to cope with N. caninum infection at this time and are more likely to transmit the parasite to the foetus. Another important factor is the gestational age and hence immuno-competence of the foetus at the time of infection. Early in gestation, N. caninum infection of the placenta and subsequently the foetus usually proves fatal, whereas infection occurring in mid to late pregnancy may result in the birth of a congenitally infected but otherwise healthy calf. Studies of foetal immune responses have shown that at 14 weeks of gestation, lymphocytes only respond to mitogen, while by 24 weeks (mid-gestation), they respond to antigen by proliferating and releasing IFNgamma. Clearly, there are several factors influencing the outcome of N. caninum infection in pregnancy: the timing, quantity and duration of parasitaemia, the effectiveness of the maternal immune response and the ability of the foetus to mount an immune response against the parasite. The challenge is to design a vaccine that will prevent foetal infection by N. caninum. This is likely to involve a fine balancing act with the immune system that will allow intervention in a manner that will tip the host-parasite balance in favour of the host without compromising the pregnancy. PMID:16098610